description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to an automatic data logging kit that is composed of data logging equipment, pressure sensors, and temperature sensors along with mechanical hardware that is used with hydraulic integrity test (HIT) skids for testing liquid cooled stator bar systems found within power generators. The kit provides automatic data logging capabilities for the pressure-decay and vacuum-decay cycle tasks, increased accuracy of the pressure-decay and vacuum-decay data, and reduced cycle time. Computer logic calculates leak rates for each of these tasks. Additionally, the equipment can be used to determine and/or accommodate leaks in the test equipment.
[0002] Large dynamoelectric equipment, such as generators, typically use branched fluid cooling systems. Parts of this equipment, such as the stator coils, are internally cooled by the circulation of a liquid. Generally, the operational atmosphere of these parts is pressurized hydrogen. The pressure of the coolant in the coil is less, by design, than the pressure of the hydrogen ambient pressure. Theoretically, a leak in a coil carrying coolant should allow the entry of hydrogen to the coil rather than venting of fluid to the atmosphere. Unfortunately, a bubble of such hydrogen gas within the coil is sufficient to at least partially block the passage of the fluid coolant, thus creating hot spots that deteriorate stator insulation, diminish conductivity and ultimately cause shutdown of the equipment.
[0003] Periodic tests of conductivity of the stators are useful in prevention of accidents and unscheduled shutdowns of the equipment. The result of such tests depend, to some extent, on the degree to which all fluids and contaminants are first removed from the cooling lines. Periodic test protocols are also useful for determining advanced warning of breakdowns in the integrity of the lines, however minute. A hydraulic integrity test skid for performing these tests on dynamoelectric equipment is disclosed in U.S. Pat. No. 5,287,726.
[0004] One of the tests performed with the use of the HIT skids is a pressure-decay test, which measures the drop in pressure over time for a potentially leaking liquid cooled stator bar system in a generator. Current methods for running the pressure-decay test cycle are to perform the test over a twenty-four hour period and manually record readings once every hour. Inaccuracies can occur, however, with a sampling rate of one reading per hour and by the manual recording of data points including internal pressure, atmospheric pressure and multiple temperature readings. Still further, inaccurate volume measurements accounting for the HIT skid internal plumbing, pressure tanks, valves and interconnecting plumbing between the HIT skid and generator pervade data input for calculations in the pressure-decay cycle, adding a level of inaccuracy into the results. In addition, inaccurate temperature measurements can undermine the test due to the dependence on temperature by internal pressure. Additionally, the twenty-four hour period for the test can be significantly reduced to shorten overall outage time.
[0005] Another test performed with the use of the HIT skids is a vacuum-decay test, which measures an increase in pressure over time for a potentially leaking liquid-cooled stator bar system after being placed in a vacuum or reduced pressure state. Problems similar to those in the pressure-decay test, however, also occur with conventional vacuum-decay testing methods.
BRIEF DESCRIPTION OF THE INVENTION
[0006] In an exemplary embodiment of the invention, an automatic data logging kit is provided for use with a hydraulic integrity test skid for testing a liquid cooled stator bar system. The automatic data logging kit includes a spool piece having end connectors attachable between the liquid cooled stator bar system and the hydraulic integrity test skid and a plurality of sensor receptacles. At least one temperature sensor is insertable within an interior of the liquid cooled stator bar system and includes an output connector operatively securable in a first of the sensor receptacles. At least one pressure sensor is operatively securable in a second of the sensor receptacles. A control unit receives output from the sensors and calculates a leak rate based on the received sensor output.
[0007] In another exemplary embodiment of the invention, the automatic data logging kit includes a spool piece with end connectors attachable between the liquid cooled stator bar system and the hydraulic integrity test skid. An elongated temperature probe is insertable within an interior of the liquid cooled stator bar system and has an output connector operatively securable in a first of the sensor receptacles. With the pressure sensor secured in a second of the sensor receptacles, a control unit receives output from the sensors and calculates a leak rate based on the received sensor output.
[0008] In yet another exemplary embodiment of the invention, a method of automatically logging data for testing a generator cooling system includes the steps of (a) logging data concerning temperature and pressure within the generator cooling system, the data being received from sensor outputs operatively coupled with the generator cooling system; and (b) automatically calculating a leak rate based on the logged data.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] [0009]FIG. 1 shows the automatic data logging kit disposed between a liquid cooled stator bar system and a hydraulic integrity test skid; and
[0010] [0010]FIG. 2 shows the automatic data logging kit of FIG. 1 with a temperature probe extending within an interior of the liquid cooled stator bar system.
DETAILED DESCRIPTION OF THE INVENTION
[0011] The automatic data logging kit of the present invention works with any generator liquid cooled stator bar system and any HIT skid that could be used for testing a generator cooling system. With reference to FIG. 1, the ADL kit 10 is installed between the stator bar system SB and the HIT skid. The kit itself is a self-contained package housing the various hardware components, including pressure sensors, temperature sensors, wiring, adaptors, field-ready computer hardware, etc. The robust system uses adaptors to plumb into the existing lines between the generator plumbing and the HIT skid.
[0012] A spool piece 12 is provided with an isolation valve 14 and sensor receptacles 16 as connections for the temperature and pressure sensors. The isolation valve 14 can be formed of any suitable construction and ensures robust and positive sealing designed for field use longevity to selectively block flow to the HIT skid. End connectors 18 are provided at ends of the spool piece 12 to facilitate connection to the existing lines. A suitable end connector is the Quick Flange, Model NW 50 ISO-QF available from JPS Vacuum Products of Norwalk, Conn.
[0013] The spool piece 12 is provided with plumbing provisions for enclosing three or more pressure sensors 20 in a manner that the sensors are protected for field use. Using three pressure sensors 20 , such as pressure transducers, computer hardware and logic can be used to monitor the three sensors 20 simultaneously and detect if one of the pressure sensors is malfunctioning by comparing to the other two readings. As a consequence, accurate pressure readings throughout the ADL kit's use can be ensured.
[0014] With reference to FIG. 2, a temperature probe 22 is insertable within an interior of the liquid cooled stator bar system SB and is subsequently coupled to an output connector 24 during assembly. The output connector 24 enables the signals or data from the temperature probe 22 to be transmitted to a control unit 26 (described below). The temperature probe 22 is preferably provided with multiple zones 28 of temperature monitoring. Three zones 28 are shown in FIG. 2. The temperature zones 28 are spaced, preferably equally spaced, along the length of the probe 22 . A three-foot entry length near the terminal end 34 may be included. There may be several different length probes designed and fabricated to allow for generators of varying sizes as well as more or fewer temperature zones 28 . For example, one length of the probe may be ten feet long, with another length being twenty feet long.
[0015] Preferably, each of the measurement zones 28 will be provided with three or more temperature sensors 30 , such as thermocouples, RTD's (resistance temperature devices) or the like for redundancy, enabling the control system to determine whether one or more of the temperature sensors is malfunctioning. Additionally, the probe 22 is designed to be prevented from contacting the wall surface of the generator, for example via the use of a protective sleeve with air gaps at the temperature sensor locations or via a mesh layer between the protective layer and the temperature sensors.
[0016] Preferably, the temperature probe 22 is enclosed in a protective sheath to protect the sensor wires. The tip 32 of the probe is constructed with a rounded nose cone piece to prevent the probe from entering the side ports for the hose nipples. The terminal end 34 of the probe is provided with one connector permanently fixed to make all the connections for the multiple temperature sensors 30 , yet be compact enough to fit within the two-inch diameter plumbing. The connection also features a robust and secure safety mechanism to eliminate the chances of accidental disconnection. In this context, in a preferred embodiment, this connection should be strong enough to withstand a tensile force of at least fifteen pounds to prevent a snagged line from being disconnected inadvertently. Additionally, the connections may be keyed to prevent user confusion. The terminal end 34 of the probe 22 is coupled with the output connector 24 .
[0017] The control unit 26 contains a computer system including a display, such as an LCD display with or without touchscreen functionality or the like, and receives data outputs from the pressure sensors 20 and temperature sensors 30 via cables 36 or via wireless communication. The computer system of the control unit 26 may be any known system suitable for the described purpose. Generally, the system includes at least a CPU, memory and components for interfacing with a user. The control unit 26 records the signals from the sensors, converting electronic values to engineering units, logs the data and computes leak rates and related theoretical data such as the exponential time decay constant for the leaks.
[0018] To perform a test, a pressure differential is effected in the generator windings either positively via the HIT skid compressor to about 60-90 psi or negatively via the HIT skid vacuum component to less than atmospheric pressure. The sampling rate will be significantly smaller than the current one reading per hour sampling rate of conventional arrangements. Preferably, data readings from the various sensors are logged at periodic intervals, such as every five to ten minutes or more for a duration up to twenty-four hours. The system is capable of recording data at much more frequent intervals if desirable, such as 0.01 Hz or faster. For every time interval of data logging, software stored within the computer system saves the data to internal storage media to prevent loss of cumulative data in the event of a power outage or disruption. The computer system actively monitors the incoming data during the test and computes a leak rate factoring in all possible effects of error, such as sensor tolerance, average temperature readings, and hardware tolerances. Once a leak rate is calculated that is not affected by the noted tolerances, the leak rate is immediately reported. Audible and visual alarms may accompany the reported leak rate, allowing the operator to end the test early for a leak rate that clearly passes or fails the pressure decay cycle.
[0019] Preliminary testing suggests that a calculated leak rate from a pressure-decay cycle can be attained in as little as two hours and from a vacuum-decay cycle in as little as one hour. Averaging and computer logic is used to reduce the effect of noise and smooth data trend lines. Assuming all sensors are operating properly, recorded data points are logged as the average of the multiple sensors at a specific location. As noted above, the computer system detects if one of the multiple sensors is faulty by comparing its readings to correspondingly located sensors. In the event that a faulty sensor is detected, the system uses only the average reading between the remaining sensors. The system will also indicate to the user visually via the display which sensor may be faulty and that its reading is not being logged nor used in the calculations.
[0020] For a pressure-decay cycle, data may be logged anywhere from four to twenty-four hours, dependent upon the calculated leak rate. After four hours, an average leak rate can be calculated and reported to the user. If the leak rate is of a steady state nature and constant value, then the pass/fail criteria may be applied and the test may be stopped. If the leak rate is still fluctuating with no attainable trend line, then the average leak rate is not reported and the test continues to run for another fifteen minutes. Subsequently, every fifteen minutes thereafter, the same logic evaluates the trend line and determines if a reportable leak rate exists.
[0021] The computer system of the control unit 26 calculates the leak rate based on the ideal gas law:
pv=mR
air
T
[0022] where p=Absolute Internal Pressure (lb f /ft 2 )
[0023] v=Internal Volume (ft 3 )
[0024] m=Mass of Air (lb m )
[0025] T=Absolute temperature of air (° R)
[0026] R air =Constant for air (ft−lb f /lb m −°R) (value of 53.384 for air).
[0027] The resulting equation for calculating the leak rate is:
L = 239.36 · V H · { M1 + B1 273.15 + T1 - M2 + B2 273.15 + T2 }
[0028] where:
[0029] L=Leak Rate (ft 3 /day)
[0030] V=Test Volume (ft 3 )
[0031] H=Time into Test (Hours)
[0032] B1, B2=Initial (B1) and Final (B2) atmospheric pressure (″Hg)
[0033] M1, M2=Initial (M1) and Final (M2) winding pressure (″Hg)
[0034] T1, T2=Initial (T1) and Final (T2) winding temperature (° C.).
[0035] The leak rate can be evaluated faster using helium. That is, instead of pressurizing the windings using the HIT skid compressor, bottled helium may be used. If the user is pressure testing with helium, an option in the software allows the user to indicate this application. The calculated leak rate will then be multiplied by 0.385 in order to convert the leak rate for helium to the leak rate for air.
[0036] In one exemplary embodiment of the invention, the pass or fail value for this leak rate is 1.0 ft 3 /day. Of course, other predefined conditions/values may be appropriate for a particular system. The software uses this predefined condition for its logic while factoring in all sensor tolerances and inaccuracies before reporting a pass or fail result to the user.
[0037] For a vacuum-decay cycle, data preferably will be logged continuously anywhere from one to four hours. After one hour, an average leak rate can be calculated and reported to the user. If the leak rate is of a steady-state nature and constant value, then the pass/fail criteria may be applied and the test may be stopped. If the leak rate is still fluctuating with no attainable trend line, then the average leak rate is not reported and the test continues to run for another fifteen minutes. Subsequently, every fifteen minutes thereafter, the same logic evaluates the trend line again and determines if a reportable leak rate exists.
[0038] For determining the leak rate using the vacuum-decay cycle, the computer system of the control unit 26 uses the following equation:
L = 3.06 · V · P · 10 - 4 T
[0039] where:
[0040] L=Leak Rate (ft 3 /day)
[0041] P=Change in Pressure, P2−P1, (Microns)
[0042] T=Time into test (Hours)
[0043] V=Test volume (ft 3 ).
[0044] The pass or fail value for this leak rate in an exemplary embodiment of the invention is 3.0 ft 3 /day. The software uses this value for its logic and also factors in all sensor tolerances and inaccuracies before reporting to the user a pass or fail result.
[0045] A related vacuum-decay test can be performed for the HIT skid equipment to validate any existing minor leak rates in the test hardware. In a preferred embodiment, calculated leak rates from this test should not exceed 0.15 ft 3 /day, as the equipment should then be replaced for leakage problems. This test is run for a range of ten to thirty minutes, while leak rates are calculated and visually reported to the user after about ten minutes.
[0046] An alternate method of calculating the leak rates may be by evaluating the time constant for exponential half-life pressure-decay or vacuum-decay to occur. Other physical or theoretical methods may also be used.
[0047] To determine the test volume V for use with either the pressure-decay cycle or the vacuum-decay cycle, after the windings are pressurized to P1, the isolation valve 14 is closed, and the hose connecting the HIT skid is disconnected. A known volume, V1, is then attached to the spool piece 12 . Once connected and sealed, the isolation valve 14 is opened, and a new pressure, P2, is acquired for both volumes. The following formula is used to then calculate the internal volume of the windings:
V winding = V known P 2 P 1 - P 2
[0048] where:
[0049] V winding =Internal volume of liquid cooled stator bars
[0050] V known =Known volume attached to spool piece
[0051] P 1 =Internal absolute pressure before the isolation valve is opened
[0052] P 2 =Internal absolute pressure after isolation valve is opened.
[0053] Via the computer system interface and display and the software stored in the computer system, the user can select a view of each individual sensor's engineering value, trend line or average reading. Alternatively, the user can display groups of sensor engineering values, trend lines or average readings such as all temperature sensors in one header. The current calculated leak rate, if available, or range of leak rates calculated thus far may also be displayed. Via the user interface, the user can zoom in and zoom out to or from a specific time period on specific functions/displays, select which test to run (pressure-decay, vacuum-decay, or a vacuum test for HIT skid equipment), start, stop and reset of data collection periods for each test, save logged data points and calculated leak rates to a removable media, select engineering units, i.e., Pascal, psi, inches of Hg, etc. The system additionally includes a “reset” button or self-check/default value/zeroing function.
[0054] As an alternative to directly connecting the cables 36 to the control unit 26 , a junction box (not shown) may be used, whereby if a generator has stator bar piping headers at opposite ends (single pass flow), the junction box would eliminate multiple wires from being run across the turbine deck. Instead, the junction box has one jacketed cable connecting it to the control unit 26 . Sensor wires then only connect to the junction box at that end of the generator, and the amount of cluttered wires is reduced at the site. The junction box also helps eliminate EMI effects as the junction box transmits digital signals instead of analog signals back to the main module.
[0055] Preferably, all hardware, connections, sensors, joints, bulkheads, etc. are designed to withstand at least a positive pressure of 150 psig and a vacuum of 0.5 micron (5×10 −4 TORR) throughout a temperature range of −2 to 174° F. (−20 to 80° C.). These values, of course, are exemplary and may be altered according to particular operating conditions and parameters.
[0056] Preferably, the sensors should be chosen or designed to prevent noise interferences, such as EMF. The temperature sensors 30 , such as thermocouples or RTD's, should be able to sense temperature values in the range of 0 to 60° C., with an absolute accuracy of 0.5° C., and a relative accuracy (linearity) of 0.2° C. The internal pressure sensors, such as pressure transducers, should be able to sense pressure values in the range of 0-100 psig, with an absolute accuracy of 0.05% full scale, and a relative accuracy (linearity) of 0.05% full scale. Atmospheric pressure sensors should be able to sense pressure values in the range of 0-15 or 0-20 psia, with an absolute accuracy of 0.05% full scale, and a relative accuracy (linearity) of 0.05% full scale. Pressure sensors for detecting both internal and atmospheric pressures may alternatively be used. The pressure sensors may be provided with built-in circuitry to account for temperature changes within the specified operating temperature range and have a thermal effect of 0.003% or less. Similar to above, these values are exemplary and may be altered according to particular operating conditions and parameters.
[0057] The ADL kit of the invention offers much-improved accuracy in determining the actual leak rate of a stator bar system and is able to conclude passing or failing results in a shorter period of time. Digitizing the data collection method, the automated system records multiple data points up to and beyond the 500 hz level. This system has the ability to self-generate plots, calculations and conclusions and has the ability to transmit the data several ways, including but not limited to serial connections, USB connections, infrared connections, and Internet connections such as LAN, cable modems, or satellite modems.
[0058] While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. | An automatic data logging kit is used with a hydraulic integrity test kit for testing a liquid cooled stator bar system. The automatic data logging kit includes a spool piece having end connectors attachable between the liquid cooled stator bar system and the hydraulic integrity test kit as well as a plurality of sensor receptacles. At least one temperature sensor insertable within an interior of the liquid cooled stator bar system is coupled with an output connector operatively securable in the first of the sensor receptacles in the spool piece. At least one pressure sensor is also operatively securable in one of the spool piece sensor receptacles. A control unit receives output from the sensors and calculates a leak rate based on the received sensor output. The automatic data logging kit provides automatic data logging capabilities for pressure-decay and vacuum-decay cycle tests, increased accuracy of the pressure-decay and vacuum-decay data and reduced cycle time in determining the leak rates. | 7 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of Korean Patent Application No. 10-2006-0028977, filed on Mar. 30, 2006, which is hereby incorporated by reference as if fully set forth herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a terminal and method for selecting an item displayed on a screen.
[0004] 2. Discussion of the Related Art
[0005] In recent times, with the increasing development of information communication technologies, information and communication environments have changed. Particularly, a kiosk (an automated information terminal) installed at public places, such as governmental offices, banks, department stores, and exhibition rooms is considered a requisite for modern society and is widely used throughout the world.
[0006] In addition, mobile communication terminals are also considered requisites for modern society and are widely used throughout the world.
[0007] Recently, with the increasing use of a variety of functions on a single terminal, elements capable of performing a variety of functions have been added to the single terminal. Therefore, there are many cases where a variety of items (i.e., icons) relating to the above-mentioned functions are simultaneously displayed on a single screen.
SUMMARY OF THE INVENTION
[0008] Accordingly, the present invention is directed to a terminal and method for selecting an item displayed on a screen that substantially obviates one or more problems due to limitations and disadvantages of the related art.
[0009] An object of the present invention is to provide terminal and method for selecting items allowing a user to quickly and conveniently select one or more items when several items are displayed on a terminal screen.
[0010] Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
[0011] To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a method for selecting icons on a screen having a vertical axis and a horizontal axis comprising: defining a selection area on the screen by touching an input device; and selecting the icons that are at least partially within the selection area, wherein the input device is one of a touch screen and a touch pad.
[0012] Defining the selection area may be accomplished in several methods. A first method comprises touching the input device to locate the center of a circle; maintaining the touch for a period of time; and releasing the touch, wherein the circle has a radius according to the period of time the touch is maintained, and wherein the selection area is defined by the circle.
[0013] Another method for defining the selection area comprises touching the input device to locate a first point; while maintaining the touch locating the first point, touching the input device to locate a second point; and releasing the touches locating the first and second points. If the first point and the second point lie on a line parallel to the horizontal axis, the selection area is a vertical band located between the first and the second points. If the first point and the second point lie on a line parallel to the vertical axis, the selection area is a horizontal band located between the first and the second points. If the first point and the second point line lie on a line that is not parallel to the vertical or horizontal axes, the first point and the second point define opposing corners of a rectangle having sides parallel to the vertical and horizontal axes, and wherein the selection area is defined by the rectangle.
[0014] Still another method for defining the selection area comprises touching the input device to locate a first point, while maintaining the touch locating the first point, touching the input device to locate a plurality of additional points, and releasing the touches locating the first point and the plurality of additional points. The first point and the plurality of additional points define the vertices of a closed polygon, and the closed polygon defines the selection area.
[0015] In another aspect of the present invention, a terminal is provided comprising: an input unit; a screen having a vertical and a horizontal axis for displaying icons; and a controller for defining a selection area of the screen and for selecting icons that are located at least partially within the selection area, wherein the input device is one of a touch screen and a touch pad. The selection area is a circle having a center located by a touch on the input unit and a radius according to a period of time the touch is maintained.
[0016] Alternatively, the selection area is defined by a first point and a second point, the first point located by a first touch of the input device, and the second point located by a second touch of the input device while maintaining the first touch. If the first point and the second point lie on a line parallel to the horizontal axis, the selection area is a vertical band located between the first and the second points. If the first point and the second point lie on a line parallel to the vertical axis, the selection area is a horizontal band located between the first and the second points. If the first point and the second point line lie on a line that is not parallel to the vertical or horizontal axes, the first point and the second point define opposing corners of a rectangle having sides parallel to the vertical and horizontal axes, and wherein the selection area is defined by the rectangle.
[0017] Yet another aspect of the invention is a terminal comprising: an input unit; a screen displaying a list of items; and a controller for selecting items, wherein a first touch of the input devices identifies a first item of the list and a second touch of the input device while maintaining the first touch identifies a second item of the list, wherein when the first touch and the second touch are released, the first item and the second item, and all items therebetween are selected.
[0018] Still another aspect of the invention is a terminal comprising: an input unit; a screen displaying a list of items; and a controller for selecting items, wherein a first touch of the input device selects a first item and sequential items are selected while the first touch is maintained.
[0019] It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiments of the invention and together with the description, serve to explain the principle of the invention. In the drawings:
[0021] FIG. 1 is a block diagram illustrating a mobile terminal according to the present invention;
[0022] FIGS. 2A˜2D show display images of a mobile terminal associated with an item selection method according to a first embodiment of the present invention;
[0023] FIG. 3 is a flow chart illustrating an item selection method according to a first embodiment of the present invention;
[0024] FIGS. 4A˜4D show display images of a mobile terminal associated with an item selection method according to a second embodiment of the present invention;
[0025] FIG. 5 is a flow chart illustrating an item selection method according to a second embodiment of the present invention;
[0026] FIGS. 6A˜6D show display images of a mobile terminal associated with an item selection method according to a third embodiment of the present invention;
[0027] FIG. 7 is a flow chart illustrating an item selection method according to a third embodiment of the present invention;
[0028] FIGS. 8A˜8D show display images of a mobile terminal associated with an item selection method according to a fourth embodiment of the present invention;
[0029] FIG. 9 is a flow chart illustrating an item selection method according to a fourth embodiment of the present invention;
[0030] FIGS. 10A˜10D show display images of a mobile terminal associated with an item selection method according to a fifth embodiment of the present invention; and
[0031] FIG. 11 is a flow chart illustrating an item selection method according to a fifth embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0032] Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
[0033] It should be noted that the present invention can be applied to mobile terminals (e.g., mobile phones, PDAs, and game machines) and kiosk terminals (e.g., ATMs).
[0034] However, for the convenience of description and better understanding of the present invention, it is assumed that the present invention is applied to mobile terminals such as mobile phones. Therefore, it should be noted that the scope of the present invention is not limited to the following explanation and embodiments and can be applied to other examples as necessary.
[0035] FIG. 1 is a block diagram illustrating a mobile terminal according to the present invention.
[0036] Referring to FIG. 1 , the mobile terminal 100 , according to the present invention, includes a memory unit 110 , a display 120 , an input unit 130 , a Radio Frequency (RF) unit 140 , and a controller 150 .
[0037] The mobile terminal 100 may include not only the above-mentioned constituent components but also other components; however, the other components are not directly associated with the present invention, such that a detailed description will be omitted for convenience,
[0038] The memory unit 110 includes software programs for executing a plurality of functions provided by the mobile terminal 100 and associated data (e.g., an MP3 file, an image file, a document file, a list of phone-numbers, a list of calls, a list of SMS messages, a list of E-mails, and a list of MMS (Multimedia Message Service) messages).
[0039] The display 120 may display a variety of icons (e.g., an MP3-file icon, an image-file icon, a document-file icon, and a program-execution icon) for executing a variety of functions. Also, the display 120 may display a list of phone numbers, a list of calls, and a list of SMS messages, etc.
[0040] For the convenience of description, each of the icons or each of the lists is generically called an “item”.
[0041] Preferably, an item displayed on the touch-screen may be directly selected by a user who touches the touch-screen.
[0042] Preferably, the display 120 may be configured in the form of a touch-screen. The touch-screen may be configured by at least one of an electrostatic capacitive, a resistive overlay, an infrared beam, a surface acoustic wave, an integral strain gauge, and a piezo-electric method.
[0043] However, the following item selection method can be conveniently implemented by the user who uses his or her fingers to operate a touch screen. Therefore, the present invention assumes that the display 120 is indicative of the touch-screen.
[0044] The input unit 130 allows the user to enter a variety of commands or information in the mobile terminal 100 . The input unit 130 is a requisite for the mobile terminal 100 if the display 120 is not implemented with the touch-screen. Otherwise, if the display 120 is implemented with the touch-screen, the input unit 130 can be selectively contained in the mobile terminal 100 . The input unit 130 may also be a keypad, a touch-wheel, a touch-pad, or a voice recognition device.
[0045] The RF unit 140 processes a variety of RF signals to allow the mobile terminal 100 to communicate with a communication system using voice-call service or SMS service.
[0046] The controller 150 controls all operations of the terminal including the memory unit 110 , the display 120 , the input unit 130 , and the RF unit 140 . Particularly, the controller 150 controls the item selection method to be implemented in the mobile terminal 100 .
[0047] Embodiments of the item selection method for use in the terminal will be described.
[0048] A first embodiment of the present invention will be described with reference to FIGS. 2A˜2D and 3 .
[0049] FIGS. 2A˜2D show display images of a mobile terminal associated with an item selection method according to a first embodiment of the present invention. FIG. 3 is a flow chart illustrating an item selection method according to a first embodiment of the present invention. A plurality of MP3 music file icons are displayed on the display of the mobile terminal as shown in FIG. 2A .
[0050] A method for conveniently selecting a few icons (i.e., “Music 3” icon, “Music 4” icon, and “Music 5” icon) from among the icons according to the first embodiment of the present invention while the icons are displayed on the display of the mobile terminal will be described.
[0051] It should be noted that there is no need for the icons to be MP3 music file icons in the first and other embodiments, and the icons may also be items associated with image or document files as necessary.
[0052] As shown in FIG. 2B , the user simultaneously performs a first touch and a second touch at desired places on the touch-screen of the display 120 shown in FIG. 3 at step S 310 .
[0053] In this case, it should be noted that the simultaneous performance of the first and second touch does not indicate that the beginning and end times of the first and second touch performances must be identical with each other.
[0054] According to the present invention (including this and other embodiments), it is considered that the first touch and the second touch are simultaneously performed if the user performs the second touch while the first touch is not yet ended even though the first touch begins earlier than the second touch.
[0055] In other words, if both of the first touch and second touch performed by the user are in contact with the touch screen 120 at a specific moment, it is considered that the first touch and the second touch are simultaneously performed. Likewise, the operation is also applied to the other case where the second touch begins earlier than the first touch.
[0056] If the first touch and the second touch are simultaneously performed on the touch-screen 120 , a first point corresponding to the first touch and a second point corresponding to the second touch are entered from the touch-screen 120 as shown in FIG. 2C at step S 320 . Then, an area 230 defined by the first and second points is established at step S 330 .
[0057] Preferably, the defined area 230 may be configured in the form of a rectangle having the first and second points as opposing corners, as shown in FIG. 2C .
[0058] Area 230 may be configured in the form of a closed curve. For example, the area 230 may be in the form of a circle having the center as the first point and a radius as the second point.
[0059] In another example, the area may also be defined by a pair of parallel lines passing through the first and second points. However, for the convenience of description and better understanding of the present invention, it is assumed that the defined area is configured in the form of a rectangle.
[0060] Although the first and second points and the defined area 230 are visually denoted for better understanding of FIG. 2C , the first and second points or the area 230 may be virtually denoted on the touch-screen 120 .
[0061] If the defined area 230 is established, icons (i.e., “Music 3” icon, “Music 4” icon, and “Music 5” icon) contained in the area 230 are selected at step S 340 . The selected icons may be processed in different ways according to the user's selection of the terminal functions.
[0062] For example, as shown in FIGS. 2C and 2D , the selected icons may be deleted by a Deletion icon 210 pressed by the user, or may be sequentially played by a Play icon 220 pressed by the user.
[0063] Likewise, if the user simultaneously performs the first and second touches on the touch-screen 120 , a plurality of items can be simultaneously selected/processed, resulting in greater convenience of the user.
[0064] As can be seen from FIG. 2B , the user simultaneously performs several touches using his or her fingers. However, it should be noted that the user may also touch a plurality of points of the touch-screen using a plurality of stylus pens. The operations may also be applied to the remaining embodiments other than the first embodiment.
[0065] The first embodiment has disclosed the specific case where the user performs two touches on the touch-screen. However, the touching performance is not limited to the two touches, and may also be three or more touchings as necessary. The operations may also be applied to the remaining embodiments other than the first embodiment.
[0066] For example, if the user performs three-touching actions, a triangular-shaped area corresponding to three touching points may be established.
[0067] A second embodiment of the present invention will be described with reference to FIGS. 4A˜4D , and 5 . FIGS. 4A˜4D show display images of a mobile terminal associated with an item selection method according to a second embodiment of the present invention. FIG. 5 is a flow chart illustrating an item selection method according to a second embodiment of the present invention.
[0068] A method for conveniently selecting a few icons (i.e., “Music 3” icon, and “Music 4” icon) from among the icons according to the second embodiment of the present invention while the MP3 music file icons are displayed as shown in FIG. 4A will be described.
[0069] In FIGS. 4A and 4B , the user simultaneously touches two or more icons on the touch-screen 120 of the display at step S 510 . Although FIG. 4B shows only two icons touched by the user for the convenience of description, it should be noted that the second embodiment can also be applied to other cases where three or more icons are simultaneously touched by the user. As a result, the simultaneously-touched two or more icons are selected at the same time as shown in FIG. 4C at step S 520 .
[0070] The selected icons can be simultaneously processed according to the user's selection and a plurality of functions of the terminal. For example, the selected icons may be simultaneously deleted by the Deletion icon 210 pressed by the user, as shown in FIGS. 4C˜4D .
[0071] A third embodiment of the present invention will be described with reference to FIGS. 6A˜6D , and 7 . FIGS. 6A˜6D show display images of a mobile terminal associated with an item selection method according to the third embodiment of the present invention. FIG. 7 is a flow chart illustrating an item selection method according to a third embodiment of the present invention.
[0072] If the SMS reception list is displayed as shown in FIG. 6A , a method for conveniently selecting some icons (e.g., “SMS3” icon, “SMS4” icon, “SMS5” icon, “SMS6” icon) from among the displayed list according to the third embodiment of the present invention will be described.
[0073] Under the SMS display situation of FIG. 6A , the user simultaneously touches the “SMS2” and “SMS5” icons on the touch-screen as shown in FIG. 6B at step S 710 .
[0074] If the “SMS3” icon and the “SMS6” icon are simultaneously touched by the first touch and second touch, respectively, not only the “SMS2” and “SMS5” icons, but also the “SMS3” and “SMS4” icons are simultaneously selected as shown in FIG. 6C at step S 720 .
[0075] The selected SMS icons may be processed in different ways according to the user's selection and a variety of functions of the terminal. For example, all the icons (i.e., “SMS3” icon, “SMS4” icon, “SMS5” icon, and “SMS6” icon) can be simultaneously deleted by the Deletion icon 210 pressed by the user, as shown in FIGS. 6C˜6D .
[0076] Although the third embodiment has disclosed the SMS list, it should be noted that the present invention is not limited to the above-mentioned example, and may also be applied to phone-number and mail lists.
[0077] In addition, the third embodiment has disclosed a plurality of vertically-displayed items, it should be noted that the items may also be sequentially displayed in any direction.
[0078] In the meantime, if the user simultaneously touches the “SMS2” icon and the “SMS5” icon under the display situation of FIG. 6A , the third embodiment may consider that only the “SMS2” and “SMS5” icons have been selected as necessary. The aforementioned operations are similar to those of the second embodiment, such that a detailed description thereof will herein be omitted for the convenience of description.
[0079] A fourth embodiment of the present invention will hereinafter be described with reference to FIGS. 8A˜8D , and 9 . FIGS. 8A˜8D exemplarily show display images of a mobile terminal associated with an item selection method according to a fourth embodiment of the present invention. FIG. 9 is a flow chart illustrating an item selection method according to a fourth embodiment of the present invention.
[0080] If the SMS reception list is displayed as shown in FIG. BA, a method for conveniently selecting some icons (e.g., “SMS2” icon, “SMS3” icon, and “SMS4” icon) from among the displayed list according to the fourth embodiment of the present invention will hereinafter be described.
[0081] In FIGS. 8A and 8B , the user touches the “SMS2” icon on the touch-screen 120 ( 8 b - 1 ) at step S 910 . Therefore, the “SMS2” icon is selected as shown in ( 8 b - 2 ) of FIG. 8B . In this case, if the user takes his or her finger off of the touch-screen, only the “SMS2” icon is selected.
[0082] However, if the user continuously touches the “SMS2” icon for a predetermined period of time, the “SMS3” icon is also selected as shown in ( 5 b - 3 ) of FIG. 8B . If the user further maintains contact with the “SMS2” icon for another predetermined period of time, the “SMS4” icon is selected as shown in FIG. ( 8 b - 4 ) of FIG. 8B . In this case, if the user takes his or her finger off of the “SMS2” icon of the touch-screen as shown in ( 8 b - 5 ) of FIG. 8B , all of the “SMS2”, “SMS3”, and “SMS4” icons are completely selected at steps S 920 and S 930 .
[0083] The selected SMS messages may be processed in different ways according to the user's selection and a variety of functions of the terminal. For example, if the user touches the Deletion icon 210 as shown in FIGS. 8C and 8B , all of the “SMS2”, “SMS3”, and “SMS4” icons may be deleted at the same time.
[0084] Although the fourth embodiment discloses the SMS list, it should be noted that the present invention is not limited to this example, and may also be applied to phone-number and E-mail lists.
[0085] Although, the fourth embodiment discloses a plurality of vertically-displayed items, it should be noted that the items may also be sequentially displayed in any direction.
[0086] The fourth embodiment discloses that if a single item is continuously touched for at least one predetermined period of time, items following the selected single item are sequentially selected. However, it should be noted that the scope of the present invention is not limited to this example,
[0087] For example, if a single item is continuously touched for at least a predetermined period of time, items prior to the selected single item may be selected in inverse order, or neighboring items (i.e., previous and following items) of the selected item may also be selected as necessary.
[0088] A fifth preferred embodiment of the present invention is described with reference to FIGS. 10A˜10D , and 11 . FIGS. 10A˜10D show display images of a mobile terminal associated with an item selection method according to the fifth embodiment of the present invention. FIG. 11 is a flow chart illustrating an item selection method according to the fifth embodiment of the present invention.
[0089] If the MP3 music file icons are displayed as shown in FIG. 10A , a method for conveniently selecting some icons (e.g., “SMS3” icon, “SMS4” icon, and “SMS5” icon) from among the displayed list according to the fifth embodiment of the present invention will be described.
[0090] Under the icon display situation of FIG. 10A , the user touches a predetermined point on the touch-screen 120 as shown in ( 10 b - 1 ) of FIG. 10B at step S 1110 , and maintains the point-touching state for a predetermined period of time at step S 1120 .
[0091] A closed-curve area 230 is formed on the basis of the point shown in ( 10 b - 2 ) of FIG. 10B at step S 1130 . Although FIG. 10B shows the circular-shaped area 230 , it should be noted that the present invention is not limited to this example.
[0092] Although the area 230 has been visually denoted for better understanding of FIG. 10B , the area 230 may also be virtually denoted on the touch-screen 120 as necessary.
[0093] If the user continuously touches the area 230 for a predetermined period of time as shown in ( 10 b - 3 ) of FIG. 10B , the size of the area 230 becomes larger such that the area 230 is able to include the “Music 3”, “Music 4”, and “Music 5” icons.
[0094] In this case, if the user takes his or her finger off of the touch-screen as shown in ( 10 b - 4 ) of FIG. 10B , all of the “Music 3”, “Music 4”, and “Music 5” icons are completely selected at step S 1140 .
[0095] In this way, the selected icons may be processed in different ways according to the user's selection and a variety of functions of the terminal. For example, if the user selects on the Deletion icon 210 as shown in FIGS. 10C and 10D , all of the “Music 3”, “Music 4”, and “Music 5” may simultaneously be deleted as necessary.
[0096] The item selection method and the terminal for implementing the same according to the present invention have the following effects.
[0097] As apparent from the above description, the item selection method and the terminal for implementing the same according to the present invention can allow a user to conveniently and simultaneously select a plurality of desired items from among many items displayed on the screen.
[0098] In recent times, with the increasing development of convergence capable of providing a user with a variety of functions via a single terminal, the present invention can be conveniently applied to the latest terminal where a plurality of associated items are simultaneously displayed on a single display screen of the terminal.
[0099] Although the present invention has disclosed the display configured in the form of a touch-screen, it should be noted that the scope of the present invention is not limited to the this example and can be applied to other examples as necessary. For example, it is obvious to those skilled in the art that the present invention can also be applied to a non-touchscreen-type terminal equipped with a touch-pad substituting for the touch-screen.
[0100] It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. | A terminal and method for selecting an item displayed on a touch screen are disclosed. The method for selecting an item displayed on the screen includes simultaneously touching the screen at two or more locations to define a selection area and identifying the items within the selection area. The section area may be a rectangle, a horizontal or vertical band of the display, a circle, or sequentially arranged items of a list. Alternatively, a single touch may define a point in the display area and the bounds of the display area are defined by the time the touch is maintained. Recently, with the increasing development of multiple functions on a single terminal, the method can be conveniently applied to the latest terminal where associated items are simultaneously displayed on a single display screen of the terminal. | 6 |
This application is a Continuation-In-Part of application Ser. No. 12/000,261, filed Dec. 11, 2007, which is a Continuation-In-Part of application Ser. No. 11/303,934, filed Dec. 19, 2005.
This Application claims priority of Taiwan Patent Application No. 94147661, filed on Dec. 30, 2005, the entirety of which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a biological delivery system, and more particularly to a glutathione-based delivery system.
2. Description of the Related Art
The blood brain barrier (BBB) is composed of brain endothelial cells capable of blocking foreign substances, such as toxin, due to the tight junction therebetween. Hydrophobic or low-molecular-weight molecules, however, can pass through the BBB via passive diffusion.
Nevertheless, active compounds, such as hydrophilic protein drugs for treating cerebral or nervous diseases and analgesic peptide drugs acting on the central nervous system, cannot enter brain tissue thereby due to their large molecular weight or hydrophilicity, resulting in decomposition by enzymes.
Current researches forward various methods of allowing active compounds to pass through the BBB, including structural modification to increase hydrophobicity of drugs, absorption-mediated transport (AMT) allowing positive-charged carriers to pass via charge absorption, carrier-mediated transcytosis (CMT) allowing hydrophilic metal ions such as Na + and K + , di-peptides, tri-peptides or glucose to pass via transporters, and receptor-mediated transcytosis (RMT) allowing macro molecules such as insulin, transferrin, or low-density lipoprotein (LDL) to pass via transcytosis.
Glutathione (GSH) is an endogenous antioxidant. If its concentration in serum is insufficient, some nervous diseases, such as chronic fatigue syndrome (CFS), may occur.
In 1988, Kiwada Hiroshi provided a liposome capable of accumulation in liver comprising an N-acylglutathione such as N-palmitoylglutathione and a phospholipid such as phosphotidylcholine to target and treat liver diseases recited in JP63002922.
In 1994, Berislav V. Zlokovic asserted that glutathione (GSH) reaches and passes through the BBB of a guinea pig via a special route, such as GSH-transporter, without decomposition.
In 1995, Berislav V. Zlokovic asserted that glutathione (GSH) exists in brain astrocyte and endothelial cells with millimolar concentration.
In 1995, Ram Kannan asserted that GSH uptake depends on Na + concentration. If Na + concentration is low, GSH uptake from brain endothelial cells may be inhibited. He also pointed Na-dependent GSH transporter located on the luminal side of the BBB manages GSH uptake and Na-independent GSH transporter located on the luminal side of the BBB manages efflux of GSH. Additionally, Kannan built a rat hepatic canalicular GSH transporter (RcGSHT) system using the brains of mice and guinea pigs to analyze cDNA fragments 5, 7, and 11. The results indicate that fragment 7 represents Na-dependent GSH transporter and fragments 5 and 11 represent Na-dependent GSH transporter.
In 1999, Ram Kannan built a mouse brain endothelial cell line (MBEC-4) model simulating BBB situations. The model proved that Na-dependent GSH transporter is located on the luminal side of the MBEC-4 cell.
In 2000, Ram Kannan asserted that GSH passes through the BBB via Na-dependent GSH transporter in human cerebrovascular endothelial cells (HCEC) and Na-dependent GSH transporter exists in the luminal plasma membrane of HCEC.
In 2003, Zhao Zhiyang provided an anti-cancer pro-drug bonded with glutatione s-transferase (GST)/glutathione (GSH) by sulfonamide covalent bonds to target and treat specific cancer cells after broken of the sulfonamide bonds recited in US2003109555. This modification can protect amino groups of drugs, increase solubility thereof, and alter absorption and distribution thereof in body.
BRIEF SUMMARY OF THE INVENTION
One embodiment of the invention provides a delivery system comprising a carrier or an active compound, and a glutathione ligand or a glutathione derivative ligand, wherein the glutathione ligand or the glutathione derivative ligand is covalently bound to the carrier or the active compound, and the glutathione ligand or the glutathione derivative ligand is on an outside surface of the carrier.
One embodiment of the invention provides a compound comprising a moiety comprising a vitamin E, a vitamin E derivative or a phospholipid, a polyethylene glycol or a polyethylene glycol derivative covalently bound thereto, and a glutathione or a glutathione derivative covalently bound to the polyethylene glycol or the polyethylene glycol derivative.
A detailed description is given in the following embodiments with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawing, wherein:
FIG. 1 shows a delivery system of the invention.
FIG. 2 shows maximal possible effect (MPE) of various met-enkephalin carriers of the invention.
FIG. 3 shows area under curve (AUC) of various met-enkephalin carriers of the invention.
FIG. 4 shows maximal possible effect (MPE) of various gabapentin carriers of the invention.
FIG. 5 shows area under curve (AUC) of various gabapentin carriers of the invention.
FIG. 6 shows serum stability of free met-enkephalin and met-enkephalin in liposomes.
DETAILED DESCRIPTION OF THE INVENTION
The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
One embodiment of the invention provides a delivery system comprising a carrier or an active compound, and a glutathione ligand or a glutathione derivative ligand. The glutathione ligand or the glutathione derivative ligand is covalently bound to the carrier or the active compound. The glutathione ligand or the glutathione derivative ligand is on an outside surface of the carrier.
The carrier may comprise a nanoparticle, a polymeric nanoparticle, a solid liquid nanoparticle, a polymeric micelle, a liposome, microemulsion, or a liquid-based nanoparticle. The liposome may comprise at least one of lecithin such as soy lecithin and hydrogenated lecithin such as hydrogenated soy lecithin.
The liposome may further comprise cholesterol, water-soluble vitamin E, or octadecyl amine to increase serum resistance or charge amounts. The molar composition ratio of the liposome may be 0.5-100% of lecithin or hydrogenated lecithin, 0.005-75% of cholesterol or water-soluble vitamin E, and 0.001-25% of octadecyl amine.
The carrier may further encapsulate an active compound with an encapsulation efficiency of about 0.5-100%. The active compound may comprise small molecule compounds such as gabapentin, peptides such as enkephalin, proteins, DNA plasmids, oligonucleotides, or gene fragments and have a molar ratio of about 0.0005-50% in the carrier.
The sulfhydryl group (—SH) of the glutathione ligand may be modified to form the glutathione derivative ligand. The glutathione derivative ligand may have formula (III).
In formula (III), the original sulfhydryl group (—SH) of the glutathione ligand is replaced by —SR. R may comprise C1-10 alkyl or lactoyl (—CO—CH(OH)—CH3).
The glutathione derivative ligand may have formula (IV).
In formula (IV), the original sulfhydryl group (—SH) of the glutathione ligand is replaced by sulfonic acid (—SOOOH).
The carrier or the active compound may target glutathione transporters of organs such as a heart, lung, liver, kidney, or blood brain barrier (BBB).
Specifically, the active compound may pass through the blood brain barrier, such as brain endothelial cells, with a cell penetration rate of about 0.01-100%.
One embodiment of the invention provides a compound comprising a moiety comprising a vitamin E, a vitamin E derivative or a phospholipid, a polyethylene glycol or a polyethylene glycol derivative covalently bound thereto, and a glutathione or a glutathione derivative covalently bound to the polyethylene glycol or the polyethylene glycol derivative.
The vitamin E derivative may comprise tocopherol derivatives or tocotrienol derivatives and may be α-tocopherol, β-tocopherol, γ-tocopherol, δ-tocopherol, α-tocotrienol, β-tocotrienol, γ-tocotrienol, δ-tocotrienol, α-tocopherol succinate, β-tocopherol succinate, γ-tocopherol succinate, δ-tocopherol succinate, α-tocotrienol succinate, β-tocotrienol succinate, γ-tocotrienol succinate, δ-tocotrienol succinate, α-tocopherol acetate, β-tocopherol acetate, γ-tocopherol acetate, δ-tocopherol acetate, α-tocotrienol acetate, β-tocotrienol acetate, γ-tocotrienol acetate, δ-tocotrienol acetate, α-tocopherol nicotinate, β-tocopherol nicotinate, γ-tocopherol nicotinate, δ-tocopherol nicotinate, α-tocotrienol nicotinate, β-tocotrienol nicotinate, γ-tocotrienol nicotinate, δ-tocotrienol nicotinate, α-tocopherol phosphate, β-tocopherol phosphate, γ-tocopherol phosphate, δ-tocopherol phosphate, α-tocotrienol phosphate, β-tocotrienol phosphate, γ-tocotrienol phosphate, or δ-tocotrienol phosphate.
The phospholipid may have formulae (I) or (II).
In formula (I), A 1 may be sphingosine and R 1 may comprise octanoyl or palmitoyl. In formula (II), A 2 may be phosphoethanoamine and R 2 may comprise myristoyl, palmitoyl, stearoyl, or oleoyl.
The polyethylene glycol or the polyethylene glycol derivative may have a polymerization number (n) of about 6-210. The molecular weight of the polyethylene glycol or the polyethylene glycol derivative may be altered with various vitamin E derivatives or phospholipids. For example, when PEG or its derivative is bound to vitamin E derivatives, it may have a molecular weight of about 300-10,000, when PEG or its derivative is bound to the phospholipid represented by formula (I), it may have a molecular weight of about 750-5,000, and when PEG or its derivative is bound to the phospholipid represented by formula (II), it may have a molecular weight of about 350-5,000.
The polyethylene glycol derivative may comprise carboxylic acid, maleimide, PDP, amide, or biotin.
The sulfhydryl group (—SH) of the glutathione may be modified to form the glutathione derivative. The glutathione derivative may have formula (III).
In formula (III), the original sulfhydryl group (—SH) of the glutathione is replaced by —SR. R may comprise C1-10 alkyl or lactoyl (—CO—CH(OH)—CH3).
The glutathione derivative may have formula (IV).
In formula (IV), the original sulfhydryl group (—SH) of the glutathione is replaced by sulfonic acid (—SOOOH).
Referring to FIG. 1 , a delivery system of the invention is illustrated. The delivery system 10 comprises a carrier 20 and a ligand 30 bound thereto. The ligand 30 comprises a moiety 40 comprising a vitamin E, a vitamin E derivative or a phospholipid, a polyethylene glycol or a polyethylene glycol derivative 50 bound thereto, and a glutathione or a glutathione derivative 60 bound to the polyethylene glycol and the polyethylene glycol derivative.
Active compounds, such as proteins, peptides, or small molecules, transported by the targeted carrier with a novel glutathione ligand provided by the invention can effectively pass through blood brain barrier by carrier-mediated transcytosis (CMT) or receptor-mediated transcytosis (RMT) to treat cerebral or nervous diseases.
EXAMPLE 1
A stirred solution of N-Cbz Benzyl amino acid (N-Cbz Glutamine, 1.0 equiv) and N-hydroxysuccinimide(HOSu, 1.0 equiv) in DME (15 mL) was cooled to 0° C. Dicyclohexylcarbodiimide(DIC, 1.0 equiv) was added and stirred at this temperature for 4 hr. The reaction mixture was allowed to stand for 2 hr in a refrigerator and then filtered.
As expected, the pure compound was obtained in excellent yield (98%) after filtration of the dicyclohexylurea (DCU) formed and evaporation of the solvent. The residue was triturated in Et 2 O/hexanes, filtered out, and then dried in vacuo to afford a white solid.
The (+)—S-tritylcysteine lithium salt (H-Cys(STrt)-OLi, 1.0 equiv) and sodium carbonate (Na 2 CO 3 , 5.0 equiv) were dissolved in water (15 mL), and then acetonitrile (CH 3 CN) was added followed by the intermediated product obtained in Step-2. The mixture was vigorously stirred at room temperature for 3-6 hr until the TLC analysis indicated the absence of intermediated product in Step-2. The solution was washed with water (2*100 mL) and the organic phase was dried with Na 2 SO4, filtered, and concentrated in vacuo to afford the compound 2.
A stirred solution of compound 2 and N-hydroxysuccinimide (HOSu, 1.0 equiv) in DME (15 mL) was cooled to 0° C. Dicyclohexylcarbodiimide (DIC, 1.0 equiv) was added and stirred at this temperature for 4 hr. The reaction mixture was allowed to stand for 2 hr in a refrigerator and then filtered.
After the DCU and solvent was removed, the glycine lithium salt (H-Gly-OLi, 1.0 equiv) and sodium carbonate (Na 2 CO 3 , 5.0 equiv) were dissolved in water (15 mL), and then acetonitrile (CH 3 CN) was added followed by the intermediated product obtained in Step-4. The mixture was vigorously stirred at room temperature for 3-6 hr until the TLC analysis indicated the absence of intermediated product in Step-4. The solution was washed with water (2*100 mL) and the organic phase was dried with Na 2 SO 4 , filtered, and concentrated in vacuo to afford the compound 3.
The d-alpha tocopheryl polyethylene glycol 1000 succinate (TPGS-OH) was coupling with compound 3 via esterification to afford the compound 4.
The compound 4 in methanol (100 mL) was added 10% Pd—C (0.2 times the weight of protected tripeptide-TPGS). The suspension was stirred at room temperature for 16 hr under a balloon filled with hydrogen. The suspension was filtered through Celite and evaporated, and the residue was crystallized from ethanol. Then, the compound 5 was obtained.
Triethylsilane (Et 3 SiH) and TFA-mediated deprotection of compound 5 in the presence of CH 2 Cl 2 provided the compound 6 (that is GSH-TPGS).
The preparation of TPGS-Glutathione derivatives is similar to the foregoing processes. The distinctions therebetween are simply further modifications of the sulfhydryl group (—SH) of the TPGS-Glutathione. For example, modifications may be performed, by substitutable groups such as C1-12 alkyl or lactoyl (—CO—CH(OH)—CH3), or oxidization to form sulfonic acid (—SOOOH). The Glutathione and its derivatives are covalently bound to the TPGS with an ester bond.
Preparation of Met-Enkephalin Carrier Solution
0.5 g lipid containing 83.2% soybean phosphatidylcholine (SPC), 4.2% α-tocopherol succinate PEG 1500 (TPGS), 4.2% glutathione-TPGS (GSH-TPGS), and 8.4% cholesterol was placed in a 12.5 mL ZrO 2 mortar. Appropriate amounts of met-enkephalin were dissolved in 10 mM phosphate solution with pH7.4 to form a 4% drug solution. 0.5 mL drug solution and five ZrO 2 beads (10 mm of diameter) were then added to the mortar and ground with 500 rpm for one hour to form a sticky cream. Next, 0.2 g sticky cream and 1.8 mL phosphate solution (10 mM, pH7.4) were added to a 10 mL flask to hydrate under room temperature for one hour to form a carrier solution containing liposomes encapsulating met-enkephalin. The concentration of met-enkephalin in a liposome was 0.56 mg/mL. The encapsulation efficiency thereof was 33.3%. The mean diameter of the carrier was 173.1 nm as well as the polydispersity index (PI) was 0.243.
EXAMPLES 2-6
Preparation methods of Examples 2-6 are similar to Example 1. The distinctions therebetween are the various carrier compositions. Please see Tables 1 and 2.
TABLE 1
Soy
H-soy
Octadecyl
Met-
Examples
lecithin
lecithin
Cholesterol
TPGS
TPGS-GSH
amine
enkephalin
2
10
—
1
—
1
—
0.48
3
10
—
1
—
1
1
1.60
4
9
1
1
0.5
0.5
—
1.60
5
9
1
1
0.75
0.25
—
1.60
6
9
1
1
—
1
—
1.60
TABLE 2
Met-enkephalin
Mean diameter
concentration
Encapsulation
Examples
(nm)
PI
(mg/mL)
efficiency (%)
2
162.7
0.227
0.56
31.70
3
161.4
0.046
4.00
70.33
4
214.1
0.003
3.25
68.85
5
165.3
0.137
3.40
68.48
6
214.5
0.116
3.99
80.78
EXAMPLE 7
Preparation of Gabapentin Carrier Solution
0.5 g lipid containing 83.2% soybean phosphatidylcholine (SPC), 4.2% α-tocopherol succinate PEG 1500 (TPGS), 4.2% glutathione-TPGS (GSH-TPGS), and 8.4% cholesterol was placed in a 12.5 mL ZrO 2 mortar. Appropriate amounts of gabapentin were dissolved in 10 mM phosphate solution with pH7.4 to form a 10% drug solution. 0.5 mL drug solution and five ZrO 2 beads (10 mm of diameter) were then added to the mortar and ground with 500 rpm for one hour to form a sticky cream. Next, 0.2 g sticky cream and 1.8 mL phosphate solution (10 mM, pH 7.4) were added to a 10 mL flask to hydrate under room temperature for one hour to form a carrier solution containing liposomes encapsulating gabapentin. The concentration of gabapentin in a liposome was 1.08 mg/mL. The encapsulation efficiency thereof was 35.7%. The mean diameter of the carrier was 147.7 nm as well as the polydispersity index (PI) was 0.157.
COMPARATIVE EXAMPLE 1
Preparation of Met-Enkephalin Carrier Solution
0.5 g lipid containing 83.2% soybean phosphatidylcholine (SPC), 8.4% α-tocopherol succinate PEG 1500 (TPGS), and 8.4% cholesterol was placed in a 12.5 mL ZrO 2 mortar. Appropriate amounts of met-enkephalin were dissolved in 10M phosphate solution with pH7.4 to form a 4% drug solution. 0.5 mL drug solution and five ZrO 2 beads (10 mm of diameter) were then added to the mortar and ground with 500 rpm for one hour to form a sticky cream. Next, 0.2 g sticky cream and 1.8 mL phosphate solution (10 mM, pH 7.4) were added to a 10 mL flask to hydrate under room temperature for one hour to form a carrier solution containing liposomes encapsulating met-enkephalin. The concentration of met-enkephalin in a liposome was 0.57 mg/mL. The encapsulation efficiency thereof was 31.1%. The mean diameter of the carrier was 164.1 nm as well as the polydispersity index (PI) was 0.281.
COMPARATIVE EXAMPLES 2-3
Preparation methods of Comparative Examples 2-3 are similar to Comparative Example 1. The distinctions therebetween are the various carrier compositions. Please see Tables 3 and 4.
TABLE 3
Comparative
Soy
H-soy
Octadecyl
Met-
Examples
lecithin
lecithin
Cholesterol
TPGS
amine
enkephalin
2
10
—
1
1
1
1.60
3
9
1
1
1
—
1.60
TABLE 4
Met-enkephalin
Comparative
Mean diameter
concentration
Encapsulation
Examples
(nm)
PI
(mg/ml)
efficiency (%)
2
159.7
0.103
3.58
70.17
3
149.0
0.168
3.22
69.67
COMPARATIVE EXAMPLE 4
Preparation of Gabapentin Carrier Solution
0.5 g lipid containing 83.2% soybean phosphatidylcholine (SPC), 8.4% α-tocopherol succinate PEG 1500 (TPGS), and 8.4% cholesterol was placed in a 12.5 mL ZrO 2 mortar. Appropriate amounts of gabapentin were dissolved in 10 mM phosphate solution with pH 7.4 to form a 10% drug solution. 0.5 mL drug solution and five ZrO 2 beads (10 mm of diameter) were then added to the mortar and ground with 500 rpm for one hour to form a sticky cream. Next, 0.2 g sticky cream and 1.8 mL phosphate solution (10 mM, pH 7.4) were added to a 10 mL flask to hydrate under room temperature for one hour to form a carrier solution containing liposomes encapsulating gabapentin. The concentration of gabapentin in a liposome was 1.17 mg/mL. The encapsulation efficiency thereof was 38.5%. The mean diameter of the carrier was 155.8 nm as well as the polydispersity index (PI) was 0.186.
EXAMPLE 8
In vitro Penetration Rate Test 1 of Met-Enkephalin Liposome
The penetration rate of met-enkephalin was measured using a RBE4/glioma cell model simulating BBB situations. The test results of Examples 1-2 (containing glutathione) and Comparative Example 1 (without glutathione) are compared in Table 5.
TABLE 5
Examples
Drug dose (μg)
Penetration rate (%)
SD
Comparative Example 1
182.6
3.4
0.6
Example 1
167.7
9.8
1.3
Example 2
165.2
9.8
1.2
The results indicate that Examples 1 and 2 have an apparently higher penetration rate (9.8%) of about 2.82 times greater than Comparative Example 1 (3.4%).
EXAMPLE 9
In vitro Penetration Rate Test 2 of Met-Enkephalin Liposome
The penetration rate of met-enkephalin was measured using a RBE4/glioma cell model simulating BBB situations. The test results of Example 3 (containing glutathione) and Comparative Example 2 (without glutathione) are compared in Table 6.
TABLE 6
Examples
Drug dose (μg)
Penetration rate (%)
SD
Comparative Example 2
250.0
3.55
0.36
Example 3
250.0
6.99
1.43
Example 3 (glutathione
250.0
0.25
0.03
added)
The results indicate that Example 3 has an apparently higher penetration rate (6.99%) of about 1.96 times greater than Comparative Example 2 (3.55%). Additionally, if cells were cultured with glutathione for 30 min before Example 3 was performed, the penetration rate thereof was lowered by 0.25% due to the addition of glutathione which occupied the glutathione transporter of the cells to block binding of carriers, reducing drug penetration through the BBB. The result proves that the glutathione carrier provided by the invention passes through the BBB via glutathione ligand/transporter binding to induce carrier-mediated transcytosis (CMT) or receptor-mediated transcytosis (RMT).
EXAMPLE 10
Hot-Plate Test of Met-Enkephalin Liposome
After a laboratory mouse on a 55° C. hot plate was intravenously injected, the analgesic effect on heat-induced pain was evaluated. Referring to FIG. 2 , for carriers without glutathione (Comparative Example 3), 90 min after injection, the maximal possible effect MPE) of a 30 mg/mL dose was 13%. For carriers containing glutathione (Example 5), 60 min after injection, the maximal possible effect (MPE) of 30 mg/mL dose was 37%. Referring to FIG. 3 , according to the area under curve (AUC), Example 5 provides 3.2 times the analgesic effect of Comparative Example 3 and 14.7 times the met-enkephalin solution. Thus, drugs can be safely carried by the carrier with glutathione ligand to pass through the BBB to achieve analgesic effect.
EXAMPLE 11
Hot-Plate Test of Gabapentin Liposome
After a laboratory mouse on a 55° C. hot plate was intravenously injected, the analgesic effect on heat-induced pain was evaluated. Referring to FIG. 4 , for carriers without glutathione (Comparative Example 4), 270 min after injection, the maximal possible effect (MPE) of a 10 mg/mL dose was 3.15%. For carriers containing glutathione (Example 7), 180 min after injection, the maximal possible effect (MPE) of a 10 mg/mL dose was 4.47%. Referring to FIG. 5 , according to the area under curve (AUC), Example 7 provides 1.54 times the analgesic effect of Comparative Example 4 (p<0.005) and 2.76 times the gabapentin solution (p<0.0005). Thus, drugs can be safely carried by the carrier with glutathione ligand to pass through the BBB to achieve analgesic effect.
EXAMPLE 12
Serum Stability Test of Met-Enkephalin Liposome
The carriers provided by Example 5 and fetal bovine serum (FBS) were mixed with 1:1 (v/v) to form a solution. After being placed in a 37° C. water bath for 0, 1, 2, and 4 hours, respectively, the solution was analyzed by gel filtration (Sephrox CL-4B, 75 mm×120 mm) and measured residual concentration of met-enkephalin in liposomes. The results are shown in FIG. 6 .
The results indicate that the concentration of met-enkephalin in liposomes remains 93% above. However, residual concentration of free met-enkephalin decreases to 2%. It is clear that the carrier provided by the invention has high serum resistance.
While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements. | A delivery system is provided. The delivery system includes a carrier or an active compound and a glutathione or a glutathione derivative grafted thereon. The invention also provides a compound including a moiety comprising a vitamin E derivative or a phospholipid derivative, a polyethylene glycol (PEG) or a polyethylene glycol derivative bonded thereto, and a glutathione (GSH) or a glutathione derivative bonded to the polyethylene glycol or the polyethylene glycol derivative. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 13/138,490, filed on Aug. 25, 2011, which is a National Stage application of International Application No. PCT/CH2010/000023, filed on Feb. 1, 2010, which claims priority of Swiss application Serial Number 00287/09, filed on Feb. 26, 2009, all of which are incorporated herein by reference in their entireties.
FIELD OF INVENTION
[0002] The present invention relates to a method for preserving food, in which the food is heated in a moist state in a container, which has a venting opening and is suited as transport and retail packaging, by way of microwaves for a limited time, however at least until hot steam forms in the container and exits through the venting opening. After the heating process, a gas is injected into the container using a cannula, and for this purpose a container wall made of a plastic film is pierced with the cannula. After the gas injection, the venting opening and the pierced hole formed by the cannula in the plastic film are closed.
BACKGROUND
[0003] A method of the aforementioned type is known from WO 2006/084402 A1. In this method the injection of the gas, in particular, serves to avoid the formation of a significant vacuum in the container as a result of condensing steam once said container has been closed.
[0004] Reference is made in WO 2006/084402 A1 to EP 1 076 012 A1 with regard to the design of the container. The containers known from EP 1 076 012 A1 have a flat deep-drawn shell made of polypropylene with a peripheral edge. A peripheral weld seam is used to weld a cover film onto this edge, for which 12 μm polyester is covered over approximately 90-100 μm polypropylene. It is this multi-layered plastic film which is pierced by the cannula in order to inject the gas.
[0005] It is further known from WO 2006/084402 A1 to use a gas which is low in oxygen or free from oxygen and to use this to flush the container in order to reduce the content of oxygen in the container which could be particularly harmful to the shelf life of the food.
[0006] It is also known from WO 2006/084402 A1 to seal the pierced hole produced with the cannula during the injection process and to simultaneously seal the venting opening by applying an adhesive label.
SUMMARY
[0007] The present invention aims to improve the known method. In particular it has been found that the above-mentioned plastic film is not sufficiently stable, bulges too much when subjected to high temperature and pressure during the heating process, and tends to become rippled as a result of shriveling once the heating process has finished.
[0008] In contrast to EP 1 076 012 A1, where the container is opened after the heating process in order to remove the food for consumption and the cover film is no longer important, the plastic film remains on the container for a longer period of time in the method according to the invention and significantly determines the look and appearance of the container during the retail phase.
[0009] The behavior of the known cover film is also unfavorable for the piercing by the cannula and the injection process. Ultimately, its rippling impairs the application of the adhesive label.
[0010] In accordance with the present invention, as is characterized in claim 1 , the plastic film that is used is less than 100 μm thick, at least one layer of the plastic film consisting of polyethylene terephthalate (PET) with a thickness greater than 19 μm.
[0011] Although even thinner on the whole than the film known from EP 1 076 012 A1, this film is substantially less ductile under the prevailing temperature and pressure owing to its thicker layer of PET, and returns practically completely back to its original flat form. The aforementioned problems are thus avoided.
[0012] In the plastic film used the layer of PET is oriented biaxially, in particular by corresponding stretching. The layer of PET is preferably 23 μm thick. However, it could be up to 40 μm thick.
[0013] A multi-layered plastic film in which a second layer consists of polypropylene and the layer of polypropylene is preferably only 2 to 2.5 times thicker than the layer of PET is preferably further used as a plastic film.
[0014] In order to improve tightness a barrier layer may also be provided between the two layers, wherein silicon oxide, aluminum oxide and/or ethylene vinyl alcohol is/are used, in particular, for the barrier layer in order to achieve an OTR value of approximately 1.
[0015] In accordance with the preferred embodiment of WO 2006/084402 A1, a shell-like container made of plastic is also preferably used as a container within the scope of the present invention, onto which the plastic film is welded in a planar manner as a cover film. The shell-like container may be round, have a diameter of 15-17 cm and a height of 2.5-3.5 cm for a content of approximately 300 g. Oval, rectangular or square shells can also be used.
[0016] A multi-layered plastic film in which a second layer consists of a connection layer which enables a connection between the plastic film and the shell can be used as a cover film. For example the above-mentioned layer of polypropylene can be used as a connection layer and can be welded in an effective manner to a shell made of polypropylene.
[0017] Before consumption, the food which has been preserved with the aid of the described method is heated in the packaging to consumption temperature, typically in a microwave oven. The use of microwave ovens is not possible or desired in some locations, for example in aircraft. In order to make it possible to heat the food preserved in the packaging in a conventional oven at relatively high temperatures a crystalline polyethylene terephthalate (C-PET) with a higher melting point than amorphous polyethylene terephthalate for example can be used for the shell and the at least one layer of plastic film made of polyethylene terephthalate. An adhesion promoter which enables a connection between the plastic film and the shell can be used as a connection layer. Such a container is therefore more resistant to high temperature and the preserved food contained therein can be heated in a conventional oven at temperatures of approximately 230° C.
[0018] With regard to the method, it has been found that it is sufficient to inject the gas at an overpressure of 0.05-0.8 bar, preferably of 0.2-0.4 bar, more preferably of 0.3 bar. A tearing of the plastic film starting from the pierced hole produced by the cannula as a particular weak point is thus simultaneously avoided.
[0019] A cannula with a stop collar which is set back slightly compared to the tip of said cannula is used to inject the gas. The cannula is guided in such a way that the stop collar rests at least temporarily against the outer face of the plastic film when the gas is injected.
[0020] When driven in a force-controlled manner the cannula can be prevented by the stop collar from penetrating too deeply into the container. The cannula should also not come into contact with the food where possible so it can immediately be used for a further injection of gas in a further container without having to be subjected to an expensive cleaning process. In addition, the risk of any bacteria present in a container being shifted into the subsequent gassed container is thus reduced.
[0021] If the plastic film expands again and puffs out due to the injection of the gas at the aforementioned overpressure, it presses against the stop collar, which provides additional protection against tearing of the pierced hole and produces a specific seal around the tip of the cannula. It may be advantageous to withdraw the cannula again slightly after the piercing action so as not to locally block the expansion of the plastic film at the point of piercing.
[0022] As is already known from WO 2006/084402 A1, the gas used within the scope of the present invention is also low in oxygen or free from oxygen and the container is flushed with this gas, expelling oxygen through the venting opening. This is preferably carried out until the oxygen content in the container is less than 0.2%, preferably 0.1%.
[0023] As is already provided in WO 2006/084402 A1, the venting opening and the pierced hole are then sealed by applying an adhesive label to the plastic film. In order for this to be possible, the two openings cannot of course be distanced too far from one another.
[0024] The venting opening and the pierced hole should be closed after the injection process, but not before a waiting time of at least 3 seconds has elapsed. During this waiting time the plastic film puffed out by the gas injection can be relieved again, at least in part, and can again adopt its preferably flat form, which facilitates the application of the adhesive label. In addition, the adhesion of the adhesive label is improved by the cooling of the plastic film, and this cooling is continued further after the waiting time. Having said that, however, the waiting time should not last any longer than 10 seconds.
[0025] During the waiting time the content of oxygen previously reduced by the flushing with the gas which is low in oxygen or free from oxygen increases slightly again in the container, at least if said container is arranged in ambient air for example. Although the presence of oxygen is detrimental to the shelf life of the food, an oxygen content of 4-5% is by all means favorable and sometimes even required in order to prevent the formation of botulinum toxin in the container, which requires anaerobic conditions.
[0026] In order to ensure a sufficiently long shelf life of the food, the heating should be carried out in such a way that a temperature of 90-98° C. is produced in the core of the food for 30-90 seconds.
[0027] The weight loss caused by steam exiting from the container can be determined as a criterion for whether these values have been achieved and can be compared with a predetermined threshold value in order to ascertain whether this has been exceeded.
[0028] As already emphasized in WO 2006/084402 A1, it is important for the venting opening to be of a defined size and therefore to have a defined flow resistance which also stays the same when subjected to the stresses during the heating process. In this regard, it has been found that suitable holes, which effectively satisfy these requirements, with a diameter typically of 0.5-10 mm can be formed in the plastic film by hot-needle perforation or flame perforation, but in particular by laser perforation. In this method a fusion bulge is produced around the formed hole as an edge reinforcement. The contactless laser perforation process is carried out, for example, by the use of a high-energy light which is generated by a CO 2 gas laser, wherein the material of the plastic film is plasticized and vaporized, in part, in the lens focus of the laser light.
[0029] With geometrically complex packagings, for example a cup packaging with a height of 80 to 140 mm and a small diameter of 60 to 200 mm, the steam generated during heating may possibly be insufficiently displaced by the injected gas owing to the geometry of the packaging. In the case of gas injection into the upper region of a cup packaging steam may remain in the lower third of the packaging, despite the flushing with the injected gas, and the packaging may become dented during the cooling phase.
[0030] In order to nevertheless ensure sufficient flushing argon may be used as a flushing gas. The greater density of argon compared to nitrogen leads to improved flushing, even in the lower third of a cup packaging, and thus to reduced denting of the packaging in the cooling phase. However, it has been found that a remaining oxygen content in the container of 4-7% is produced when flushing with argon in contrast to approximately 0.1% when flushing with nitrogen. However, this affords the advantage that the aforementioned formation of botulinum toxin is prevented.
[0031] A further option for preventing excessive denting after the heating process in the case of geometrically unfavorable packagings consists in carrying out a second gas injection as well as a cooling step between the first and second gas injection. The first gas injection is carried out as already described. After the first gas injection the venting opening and the pierced hole are sealed by applying an adhesive label. The adhesive label is provided with an adhesive which firmly closes the two openings and no longer opens, even at high pressure and temperature, such that the adhesive does not detach during the second gas injection owing to the slight overpressure and the possible residual heat, and no further gas can escape. The two openings remain firmly closed. The packaging is then cooled in a first cooling step. The packaging constricts slightly during this process. After the first cooling process gas is injected for a second time, the packaging not being flushed this time but merely puffed out to approximately the original form.
[0032] The pierced hole of the second gas injection is sealed by an adhesive label which ensures a hermetic seal during the storage period, but opens automatically under the effect of heat, steam and/or pressure when the product is re-heated by the consumer.
[0033] In the above-mentioned method the container can also be actively cooled externally during the first gas injection. This cooling process can be achieved, for example, by a water bath or a cooling tunnel. Such a cooling process results in an additional cooling of the food provided in the packaging, in particular if liquid has collected at the bottom of the packaging, and thus assists the cooling by the first gas injection. Such a cooling also leads to a cooling of the side walls of the packaging and thus to an increased condensation of the steam on the side walls.
FIGURES
[0034] The invention will be explained hereinafter in greater detail with reference to an embodiment in conjunction with the drawings, in which:
[0035] FIG. 1 shows a container, which is suitable for use within the scope of the method according to the invention, with a venting opening and food before said food is preserved;
[0036] FIG. 2 shows the container of FIG. 1 during heating by means of microwaves;
[0037] FIG. 3 shows the container comprising a cannula piercing into the cover film of said container;
[0038] FIG. 4 shows the injection of a gas with the cannula into the container;
[0039] FIG. 5 shows the sealing of the venting opening and of the pierced hole formed by the cannula by means of an adhesive label;
[0040] FIG. 6 shows the sealed container with the food preserved in accordance with the invention; and
[0041] FIG. 7 a shows a suitable cup packaging for use within the scope of the method according to the invention comprising with two injection steps;
[0042] FIG. 7 b shows the cup packaging of FIG. 7 a during a heating process by means of microwaves;
[0043] FIG. 7 c shows the cup packaging during a first injection of a gas with a piercing cannula;
[0044] FIG. 7 d shows the sealing of the venting opening and of the pierced hole, formed by the first cannula, by means of a permanent adhesive label;
[0045] FIG. 7 e shows the contracted cup packaging during a cooling step;
[0046] FIG. 7 f shows the cup packaging during a second injection of a gas with a piercing cannula;
[0047] FIG. 7 g shows the cup packaging sealed by a second adhesive label with the food which has been preserved in accordance with the invention.
DETAILED DESCRIPTION
[0048] FIG. 1 shows a shell-like container 10 made of polypropylene comprising a peripheral edge 11 onto which a cover film 12 , which is likewise peripheral, is welded. The weld connection is preferably peelable.
[0049] The cover film is a multi-layered plastic film less than 100 μm thick, wherein one layer consists of biaxially oriented polyethylene terephthalate (PET) and a second layer consists of polypropylene, and wherein the layer of polypropylene is 50 μm thick and the layer of PET is 23 μm thick. A high barrier which consists of silicon oxide, aluminum oxide or ethylene vinyl alcohol may be present between the two layers.
[0050] A venting opening 20 with a diameter of approximately 2.5 mm is provided in the cover film 12 and is formed by laser perforation and thus comprises a small fusion edge.
[0051] Food 30 is provided in air in the container 10 and has a specific inherent moisture and, for example, is still present in the raw/fresh state.
[0052] FIG. 2 shows the container 10 during heating with microwaves M to preserve the food 30 , wherein steam D has formed from the moisture contained in the food 30 and has caused an overpressure P> in the container 10 . Under the action of said overpressure P>, steam D together with the air which was originally present flows out from the container 10 through the venting opening 20 . The cover film 12 has also expanded and bulged under the action of the overpressure P>.
[0053] The pressure in the container 10 rapidly decreases, above all by condensing steam D, after the heating process and with cooling, in such a way that the cover film 12 can also return, at least approximately, back to its original flat form. In this phase the cover film 12 is pierced in the vicinity of the venting opening 20 by means of a cannula 40 , as shown in FIG. 3 .
[0054] The cannula 40 is provided with a stop collar 41 , which is slightly set back relative to the tip of said cannula, and is preferably inserted until said stop collar 41 rests against the outer face of the cover film 12 . The stop collar 41 , which may have a diameter of 10-20 mm, in particular of 14 mm, prevents excessively deep penetration of the cannula 40 into the container 10 . Its tip only protrudes to such an extent beyond the stop collar 41 , in particular only approximately 5-15 mm, preferably 7 mm, that it does not contact the food 30 where possible. The tip is ground to form three cutting edges which are offset from one another by 120° and are inclined by approximately 22° to the axial direction.
[0055] As is shown in FIG. 4 , a gas G is then injected via the cannula 40 into the container 10 at an overpressure of approximately 0.3 bar. The necessary gas feed to the cannula 40 is not shown in FIG. 4 , similarly to the other figures. The gas G emerges radially at a plurality of openings distributed over the periphery between the tip and the stop collar 41 of the cannula 40 . The cover film 12 expands slightly again owing to the renewed overpressure and bulges upwardly. It presses against the stop collar 41 of the cannula 40 , whereby the pierced hole denoted by 13 in FIG. 5 is additionally stabilized against tearing and a certain sealing effect is also experienced. In order to ensure that the cover film 12 is not pressed in too excessively by the cannula 40 and the stop collar 41 thereof, it is pulled back again slightly during the gas injection, for example by 1-3 cm, as is also shown in FIG. 4 .
[0056] The container 10 is flushed with the gas G, thus expelling steam D and any air still present through the venting opening 20 , and this occurs until no significant vacuum can form as a result of further steam condensation in the container after the aforementioned sealing of the container, or until the content of any oxygen contained in the container has decreased to approximately 0.1%. The injected gas must, of course, itself be free from oxygen where possible.
[0057] FIG. 5 shows the container 10 after the injection of the gas G, wherein the cannula 40 has already been withdrawn again fully from the container 10 . The container 10 must now still be sealed.
[0058] In order to close the container 10 the pierced hole 13 and the venting opening 20 in the cover film 12 are sealed by applying an adhesive label 50 . A plunger 60 which picks up the adhesive label 50 , for example from a label dispenser (not shown) and holds it, for example by suction, until it is applied on the container 10 is used to apply the adhesive label 50 .
[0059] A specific period of time between approximately 0.5 and 10 seconds elapses between the end of the gas injection and the withdrawal of the cannula 40 on the one hand, and the application of the adhesive label 50 on the other hand. During this period the overpressure generated in the container 10 by the injection of the gas G may decrease again, at least in part, owing to the venting opening and the pierced hole 13 formed in the cover film 12 by the cannula 40 , wherein the film returns to its flat form. In addition, the oxygen content in the container may advantageously increase to 4-5% owing to a specific backflow or back-diffusion of external air. Lastly, the temperature may decrease again slightly, which is advantageous in order to support the adhesive label on the film.
[0060] FIG. 6 shows the container 10 with the food 30 preserved in accordance with the invention in the gas atmosphere G and with the adhered adhesive label 50 at ambient pressure. The cover film 12 is easily drawn in under the influence of a certain subsequent condensation of residual steam once the adhesive label has been applied, but this is not detrimental to the food contained in the container and helps to ensure that the cover film is stretched tight and also remains in place in the long term. In this form the container is suitable as a transport and retail packaging and is further preferably supplied to a conventional cooling chain with cooling temperatures in the range of 1-8° C.
[0061] For sufficient preservation of the food 30 it is important that a temperature of 90-98° C. is reached for 30-90 seconds in the core of the food during the heating process. As a criterion for this the container 10 can be weighed before the heating process and after the sealing process, and from this the weight loss caused by the escape of steam can be ascertained. If it is too low, it means that a sufficient temperature has not been reached or was only reached for an insufficient period of time. The relevant container 10 can then be rejected.
[0062] Before consumption of the food preserved by the described method, it is heated in the packaging, typically in a microwave oven, to consumption temperature. In order to enable heating in conventional ovens at relatively high temperatures, the shell-like container 10 and the polyethylene terephthalate layer of the cover film 12 can consist of crystalline polyethylene terephthalate (C-PET) with a melting point above 230° C. The second layer of the plastic film is a connection layer which consists of an adhesion promoter. The cover film can thus be adhered to the edge of the shell-like container after activation of the adhesion promoter.
[0063] It may be that the gas flushing is insufficient with the use of cup-like packagings for example, and that the packaging contracts significantly after being sealed during cooling. In order to avoid this, a cooling step and a second gas injection are carried out after the gas flushing, as is shown in FIGS. 7 a - g.
[0064] FIG. 7 a shows a suitable cup packaging 70 for use within the scope of the method according to the invention with two injection steps. Food 30 in air is provided in the cup packaging 70 . The cup packaging 70 with a height of 80 to 140 mm and a diameter of 60 to 200 mm also has a cover film 12 and a venting opening 20 . It differs from the container 10 mentioned above merely in shape.
[0065] FIG. 7 b shows the cup packaging 70 of FIG. 7 a during a heating process by means-of microwaves M in order to preserve the food 30 , as has already been described for the container 10 of FIG. 2 . Steam D has formed from the moisture contained in the food 30 and the cover film 12 has expanded and bulged under the action of the overpressure P> produced. Some of the steam D, together with the air originally present in the cup packaging 70 , escapes through the venting opening 20 .
[0066] FIG. 7 c shows the cup packaging 70 during a first injection of a gas G with a cannula 40 which has pierced through and comprises a stop collar 41 . This process is also carried out in the manner as already described for the container 10 of FIG. 3 and FIG. 4 . Owing to the geometry of the cup packaging it may be that the cup packaging 70 is not sufficiently flushed and steam D remains in the lower third of the cup packaging, as shown in FIG. 7 d.
[0067] FIG. 7 d also shows the sealing of the venting opening 20 and of the pierced hole 13 , formed by the first injection, by a permanent adhesive label 80 . In this case the permanent adhesive label 80 is still retained by the plunger 60 . This permanent adhesive label 80 has an adhesive which no longer detaches, even when subjected to pressure and increased heat.
[0068] Once the permanent adhesive label 80 has been affixed, the cup packaging 70 is cooled in a cooling step from the pasteurization temperature to approximately 65° C. Depending on requirements, it can also be cooled further, for example to 2-4° C. As the cooling takes place the pressure in the cup packaging 70 decreases and the cup packaging 70 constricts under the vacuum P< produced. The cover film 12 is drawn inwards. FIG. 7 e shows the cup packaging 70 which is drawn in during a cooling step.
[0069] FIG. 7 f shows the cup packaging 70 during a second injection of a gas G with a cannula 40 which has pierced through and comprises a stop collar 41 . The second injection is carried out at a point which is offset from the first injection site. During the second injection, gas G 2 is injected until the constricted cup packaging 70 has been puffed out again to its original form. During the second injection it is suffice to apply a lower overpressure than that during the first injection. The overpressure during the second injection may be approximately 0.2 bar.
[0070] FIG. 7 g shows the cup packaging 70 , which is sealed by an adhesive label 50 , with the food 30 preserved in accordance with the invention. The adhesive label 50 is applied to the cup packaging 70 in the manner already described above for the container 10 .
[0071] Alternatively to the above-described design of the plastic film and irrespectively thereof, the design of the cannula described above could be considered as an independent inventive concept to improve the method known from WO 2006/084402 A1, in particular in terms of the stop collar and/or movement of said cannula. The same also applies at least to the waiting period between the end of the gas injection and the sealing of the container and/or to the method with an intermediate cooling step and a second gas injection.
[0072] What has been described above are preferred aspects of the present invention. It is of course not possible to describe every conceivable combination of components or methodologies for purposes of describing the present invention, but one of ordinary skill in the art will recognize that many further combinations and permutations of the present invention are possible. Accordingly, the present invention is intended to embrace all such alterations, combinations, modifications, and variations that fall within the spirit and scope of the appended claims. | A method for preserving food. The food is heated in a moist state in a container, which has a venting opening and is suited as transport and retail packaging, by way of microwaves (M) for a limited time, however at least until hot steam (D) from in the container and exists through the venting opening. After the heating has ended, a gas (G) is injected into the container using a cannula, and a container wall made of plastic film is pierced with the cannula. The plastic film that is used has a thickness of less than 100 μm. At least one layer of the plastic film is made of polyethylene terephthalate having a thickness of greater than 19 μm. | 1 |
FIELD OF INVENTION
[0001] The present invention relates to fabrication systems and plants for fabricating extended length lumber. In particular, the present invention relates to fabrication systems and plants for continuously fabricating extended length graded lumber of low quality raw lumber.
BACKGROUND OF INVENTION
[0002] In the field of architectural construction, lumber is an important structural material needed in variable grades and lengths for trusses, wall frames and the like. Well known fingerjointing techniques are employed in the lumber industry to provide lumber at lengths independently of the length of the available raw lumber. Fingerjointing is also used to provide lumber substantially without lumber strength degrading elements such as wood eyes, wanes and bents. The grading of the lumber on the other hand is accomplished by well known machinery through which the lumber may be continuously feed. The minimal length of individual finger jointed pieces is determined by method and fabrication system by means of which extended length lumber may be economically feasible mass produced. At the time of this invention, the minimal length of individual finger jointed pieces and consequently the spacing between finger joints of common extended length lumber is down to about 1 foot. As may be well appreciated by anyone skilled in the art with reducing lumber piece length a larger percentage of the raw lumber may be utilized. Lumber utilization becomes increasingly important as strength degrading lumber elements increase. Therefore, there exists a need for a fabrication system that provides for economically feasible fabrication of extended length lumber with spacing between finger joints of less than 1 foot. The present invention addresses this need.
[0003] For environmental benefit it is desirable to utilize low quality raw lumber that may be cut from small diameter tree trunks, which may contribute to preserve old growth and may promote lighter and environmentally less invasive timber harvesting machinery and techniques. Unfortunately, low quality raw lumber has a relatively large percentage of wanes, wood rind, wood eyes, bents and other strength degrading elements that degrade the technical and economic feasibility of low quality raw lumber particularly for fabricating graded structural lumber in common fabrication systems and plants. Nevertheless, low quality raw lumber such as for example well known US No. 2 type utility lumber has a theoretical content of at least 75% of well known 1650 grade and higher. Therefore, there exists a need for a fabrication system and method for continuously fabricating graded extended length lumber with maximum grade utilization of input low quality raw lumber. The present invention addresses also this need.
SUMMARY
[0004] An extended length graded lumber fabrication system features a number of fabrication stages along a substantially continuous input-to-output fabrication path providing high through put fabrication of graded lumber of extended length in conjunction with the particularities of low quality raw lumber. The fabrication stages include reject recognition stages, a supply lumber grading stage, a lumber sorting stage with additional graded lumber buffer storage paths diverting off the continuous input-to-output fabrication path, a lumber length extension stage and an extended length grading stage.
[0005] The reject recognition stages may include a lumber appearance inspection and out-sorting stage, a moisture measuring stage and a grain inconsistency scanning stage. At a reject cutout and grade separation stage lumber strength degrading elements rejected in the previous scanning stage are cut out. Lumber segments with different grade ratings are also separated. The reject cutout and grade separation stage is computerized controlled in accordance with grade, grain inconsistency information obtained at their respective stages. Grade sorted nominal and shortened length lumber propagates along secondary and tertiary graded lumber buffer storage paths onto a storage paths switching stage at which buffer storage requirements of the continuously processed supply lumber are dynamically adjusted for a continuous buffer storing and grade selective in-feeding into the continuous input-to out fabrication path immediately prior to the lumber length extension stage.
[0006] At the lumber length extension stage well known finger jointing machinery joints the individual graded and reject cleared lumber pieces into a substantially endless single grade lumber string. Part of the lumber length extension stage may also be a well known finger joint proof loader and a travel saw. The finger joint proof loader tests the finger joints according to well known specific finger joint test criteria, which differ from lumber grading criteria. The travel saw cuts computerized controlled the endless lumber coming from the finger jointer into the final extended length and cuts out failed finger joints as well as grade transitions after a dynamic grade fabrication change in the fabrication system. Due to the lumber grading prior to the lumber length extension stage, grade fluctuations of the endless lumber string are brought to a minimum. In the second lumber grading stage the grade of the extended length lumber is verified in accordance with existing grading requirements at the end of the extended lumber fabrication.
[0007] Well known chord(s) and/or well known web strut(s) of a well known wooden truss joist may be made of the single grade extended length lumber fabricated by fabrication system of the present invention.
[0008] The fabrication system may also feature a reject back insertion path diverting off the continuous input-to-output fabrication path following the travel saw and terminating at begin of the continuous input-to-output fabrication path where the raw lumber is in-feed. The raw lumber, the failed finger joint lumber and grade transition lumber may define together with eventual other scrap lumber like from truss fabrication the supply lumber.
[0009] Two separate well known lumber testing machines are preferably employed at the respective first and second lumber grading stage. Nevertheless, the scope of the invention includes an embodiment in which a single lumber grading machine is employed such that the first and second lumber grading stages coincide. Consequently, the continuous input-to-output fabrication path crosses at the coinciding first and second lumber grading stages.
[0010] Dual lumber grading is highly advantageous in minimizing grade fluctuations in the final extended length lumber. Secondary and tertiary graded lumber buffer storage paths in combination with the automated lumber sorting and buffer storage path switching provide for economic mass production of single grade extended length with finger joint spacing of less than 1 foot down to about 4 inches. The tertiary lumber buffer storage path and the reject back insertion path assist also in increasing fabrication economy by reducing lumber waste. The secondary and tertiary lumber buffer storage paths are parallel to the continuous input-to-output fabrication path with computer controlled switching gates that provide together with buffer storage along the individual paths for real time grade switching during extended length lumber fabrication. In summary, minimized grade fluctuations in the final extended length lumber, extended lumber grade bandwidth, reduced lumber waste and real time grade switching contribute to a maximum utilization of input low quality raw lumber. In addition, dynamic grade transitions are accomplished without interrupting the fabrication flow. This is an important aspect in particular in combination with utilized low quality raw lumber and mass fabricated truss components with grade variations tailored to the well known diverse needs in architectural constructions,
BRIEF DESCRIPTION OF THE FIGURES
[0011] FIG. 1 a is a schematic prior art figure of standard quality raw lumber samples.
[0012] FIG. 1 b shows a schematic prior art figure of low quality raw lumber samples as preferably utilized in the present invention.
[0013] FIG. 2 depicts a block diagram of a representative first embodiment of the invention.
[0014] FIG. 3 is a block diagram of a representative second embodiment of the invention.
[0015] FIG. 4 shows a schematic floor plan of a fabrication system according to the block diagram of FIG. 3 .
[0016] FIG. 5 depicts a schematic wooden truss joist.
DETAILED DESCRIPTION
[0017] For the purpose of general understanding of the present invention in combination with the particularities of low quality raw lumber, prior art FIGS. 1 a and 1 b schematically depict a representative assortment of standard quality lumber SQ and low quality lumber LQ. The standard quality lumber SQ of FIG. 1 a may be in minimum grade x along sections LGX. Standard quality lumber SQ has limited number of wood eyes WE and other well known lumber strength degrading elements and/or defects. Certain standards for lumber straightness may also apply to the standard quality lumber SQ
[0018] Low quality lumber LQ depicted in prior art FIG. 1 b may be of a length between 1-20 feet, with an increased number of lumber strength degrading elements and/or defects such as, wood eyes WE, rinds RD, wanes WN and other well known grain inconsistencies. Standards for straightness may be also lower than in standard quality lumber SQ. The resulting minimum utilizable grade length LG 1 -LG 4 in a low quality lumber LQ may be down to 4 inches. In case of well known United States No. 2 utility lumber, about 75% of the low quality LQ boards with their grade lengths LG 1 -LG 4 of well known 1650 grade and higher.
[0019] For an economically and technically feasible fabrication of single grade extended length lumber from low quality lumber LQ, certain fabrication steps, stages and paths are introduced in the present invention to account for the particularities of low quality raw lumber LQ. Such particularities may include the minimum utilizable grade length LG 1 -LG 2 of down to 4 inches, as well as larger grade fluctuations.
[0020] As shown in FIG. 2 , a first embodiment of the invention includes the method steps 10 of providing generic lumber, followed by the step 13 of inspecting lumber pieces for defects and/or insufficiencies. The side step 131 of removing rejected pieces takes place in conjunction with step 13 . Step 13 may include but is not limited to well known visual inspection, well known moisture scanning, and/or well known wood eye scanning. The next step 16 includes initial lumber piece grading into grades A-N and the associated step 162 of associating grade information with the graded lumber pieces. Step 16 and 162 may be performed by a well known lumber grading machine such as the METRIGUARD™ Model 7200 lumber tester. In the consecutive step 22 , the lumber pieces are grade sorted in association with the grade information of step 162 . In conjunction with step 22 , grades B-N lumber pieces are buffer stacked in side step 221 . Following both step 22 and step 221 is step 28 in which grade selective in-feeding of grade A-N lumber pieces is performed followed by step 30 of finger jointing the in-fed grade selected lumber pieces into a single grade A-N endless lumber. The endless lumber is then proof loaded in step 32 and in the associated step 322 , a finger joint failure information is associated with the corresponding endless lumber location. After step 32 , the single grade A-N endless lumber is lengthened into extended length single grade lumber and failed finger joints are removed in step 34 . In a final grading step 36 , the extended length lumber pieces are graded.
[0021] Steps 10 , 13 , 16 , 22 , 28 , 30 , 32 , 34 , 36 take place along a substantially continuous input-to-output fabrication path CP along which the lumber is substantially continuously propagating as single pieces and/or in stacks. The step 221 takes place along a secondary graded lumber buffer storage path SP. The secondary graded lumber buffer storage path SP diverts off the continuous input-to-output path CP following step 22 and rejoins the continuous input-to-output fabrication path CP at beginning of step 28 .
[0022] In FIG. 3 , a second preferred embodiment of the invention includes the method steps 10 of providing generic raw lumber, followed by the step 12 of in-feeding supply lumber pieces including the raw lumber and return in-fed lumber from steps 144 and 342 . After scanning lumber moisture in step 18 , lumber appearance is inspected in step 14 and excess moisture boards are removed in step 142 The side step 141 of removing rejected pieces that did not pass the appearance inspection takes also place in conjunction with step 14 . Appearance inspection is preferably performed by trained personnel. The removed moist lumber may be dried as in step 143 and return in-fed as in step 144 . The repeated appearance inspection of dried lumber warrants that well known excess lumber bending or well known lumber cracking that may occur during drying are recognized and removed. Moisture scanning of step 18 may be accomplished by a well known WAGNER™ Apex Moisture Detector.
[0023] The next step 16 includes initial grading of the supply lumber pieces into grades A-N and the associated step 162 of associating grade information with the graded lumber pieces. Steps 16 and 162 may be performed by a well known lumber grading machine such as the METRIGUARD™ Model 7200 lumber tester. The lumber pieces propagate along the continuous input-to-output fabrication path CP from the initial lumber grading towards the following step 20 , in which the lumber pieces are scanned for grain inconsistencies such as wood eyes WE. The grain inconsistency information is associated with the lumber pieces in associated step 202 . Steps 20 and 202 may be performed by a well known NEWNESS™ Advantage Scanner.
[0024] In the consecutive step 22 , the nominal length lumber pieces grain inconsistency testing are grade sorted in association with the grade information of step 162 . In conjunction with step 22 , grades B-N nominal length lumber pieces are secondary buffer stacked in side step 221 . Nominal length in context with the present invention means the length of the raw lumber without scrap lumber and finger joint failure lumber. The nominal length in a preferred embodiment of the invention is between 2-20 feet. Following both step 22 and step 221 is step 24 in which grain inconsistencies and excess moisture portions M are removed from the lumber pieces. In conjunction with step 241 , grades A-N cut lumber pieces are tertiary buffer stacked in side step 241 .
[0025] Next is step 28 in which grade selective in-feeding of grade A-N lumber pieces is performed followed by step 30 of finger jointing the in-fed grade selected lumber pieces into a single grade A-N endless lumber string. The endless lumber string is then proof loaded in step 32 and in the associated step 322 , a finger joint failure information is associated with the corresponding endless lumber location. After step 32 , the single grade A-N endless lumber string is lengthened into extended length single grade lumber in step 34 . Lumber portions including the failed finger joints and/or grade transitions are removed in the corresponding side step 341 . The cut out lumber portions are kept at a predetermined length for return in-feeding them at step 12 as indicated by step 342 . In a final grading step 36 , the extended length lumber pieces are graded.
[0026] Steps 10 , 12 , 14 , 16 , 18 , 20 , 22 , 24 , 28 , 30 , 32 , 34 , 36 , 38 take place along a substantially continuous input-to-output fabrication path CP along which the lumber is substantially continuously propagating as single pieces and/or in stacks. The step 221 takes place along a secondary graded lumber buffer storage path SP. The secondary graded lumber buffer storage path SP diverts off the continuous input-to-output path CP following step 22 and rejoins the continuous input-to-output fabrication path CP at beginning of step 28 . The step 241 takes place along a tertiary graded shortened lumber buffer storage path TP. The tertiary graded shortened lumber buffer storage path TP diverts off the continuous input-to-output path CP following step 24 and rejoins the continuous input-to-output fabrication path CP at beginning of step 28 . Steps 341 and 342 take place along a reject back insertion path RP diverting off the continuous input-to-output fabrication path CP following step 34 and terminating at beginning of step 12 .
[0027] The schematic floor plan of a preferred embodiment of the fabrication system 200 is shown in FIG. 4 . Along the substantially continuous input-to-output fabrication path CP propagate lumber pieces of predetermined cross section such as 2 by 4 inches on well known conveyor and/or other transport systems commonly utilized for piecewise and/or stack wise continuous lumber transport. At the begin of the continuous input-to-output fabrication path CP is a multiple lengths supply lumber in-feed stage including a hydraulic break down hoist 2122 and small piece conveyor 2124 . The hydraulic break down hoist 2122 breaks down stacked nominal length lumber that is in-fed via a first fork lift access 2101 and an in-feed deck 2121 . Short length lumber pieces, which may be down to 1 foot length are in-fed into the continuous input-to-output fabrication path CP via a second fork lift access 2102 connecting to the small piece conveyor 2124 .
[0028] After the moisture scanner 218 , a lumber appearance inspection and out-sorting stage may include an inspection deck 214 and a third forklift access 2141 . On the inspection deck, the spread lumber pieces gradually move along in lateral direction at a speed suitable for a preferred visual inspection and manual reject removal by trained personnel. The rejected boards are stacked at the third forklift access 2141 for removal.
[0029] Following the inspection deck 214 is a lateral chain feeder 2161 that redirects the remaining boards into longitudinal propagation direction towards the lumber tester 2162 of a first lumber grading stage, the moisture detector 218 of a moisture measuring stage, and the scanner 220 of a grain inconsistency scanning stage. Then the lumber enters an automated lumber sorter 222 in which the lumber pieces are laid out for further processing and/or out-sorting as part of a nominal length lumber grade sorting stage. From the sorter 222 , a nominal length conveyor 2222 receives nominal length boards grade B-N that have passed the grain inconsistency scanning. The sorter 222 may utilize grade information from the first lumber grader 2162 and grain inconsistency information obtained from the scanner 220 to perform the out-sorting in a computerized controlled fashion. Ink marks imprinted on the lumber in the lumber grader 2162 and/or the scanner 220 may be recognized by well known machine vision systems, which may include a camera. Grade marking may be for example via bar code or color code. Additionally, length information may also be coded onto the shortened length boards. In context with the present invention grade A may be preferably a grade most common for the particular quality raw in-fed lumber. In a representative case of No. 2 utility raw lumber, grade A may be the well known 1650 grade. Hence, the highest capacity throughput directly along the continuous input-to-output fabrication path CP is utilized in the most economic fashion. The nominal length conveyor 2222 terminates at a storage path switching stage in the preferred configuration of a pull table 225 and a turn table 2252 . At the pull table 225 the nominal length boards are manually sorted at secondary pull cart accesses 2225 in single grade stacks. The secondary graded lumber buffer storage path SP, which begins at the secondary pull cart accesses 2225 and terminates at the pull-cart in-feed 2287 may include well known temporary buffer storage locations not shown on the schematic plan.
[0030] Behind the automated lumber sorter 222 is a reject cutout and grade separation saw 224 , from which a short piece conveyor 2242 diverts. A waste bin 2243 that automatically captures the out cut rejected lumber portions is placed along the short piece conveyor 2242 . Also part of the storage path switching stage are tertiary cart accesses 2245 , turn table 2252 and tertiary first fork lift accesses 2246 . Lumber pieces having portions that failed the grain inconsistency scanning and/or have more than one grade LG 1 -LG 4 along their length are computerized controlled diverted towards the saw 224 where the rejected lumber portions are cut out in accordance with the grain inconsistency information and grade lengths LG 1 -LG 4 are separated in accordance with grade information from the supply lumber grader 2162 . The remaining grade A-N shortened length lumber pieces end up on the pull table 225 together with the grade B-N sorted nominal length boards. Employing a storage path switching stage for grade selective sorting of nominal and shortened length boards provides necessary flexibility to adjust to varying grade compositions of the supplied and/or raw lumber. On the pull table 225 boards in the length down to about 2 feet are sorted. On the adjacent turn table 2252 , boards of lengths down to about 6 inches are manually grade sorted stacked on pallets on the tertiary first fork lift accesses 2246 for further fork lift manipulation. The tertiary graded lumber buffer storage paths TP, which begin at the tertiary accesses 2245 , 2246 and terminate at the in-feeds 2287 and 2280 may include well known temporary buffer storage locations not shown on the schematic plan. The manually operated pull table 225 and turn table 2252 may be substituted by an automatic tables and/or well known robotic equipment as may be well appreciated by anyone skilled in the art
[0031] The remaining grade A nominal length lumber passes through a stacker in-feed 2261 , a stacker 2262 and stack jump roll case 2263 , where it is either directly redirected via a stack cross over rollcase 2281 towards a single grade lumber length extension stage or buffer stored in between an stack out-feed deck 2264 and stack in-feed deck 2283 . Stack out-feed deck 2264 has a forth fork lift access 2265 and the stack in-feed deck 2283 has a fifth fork lift access 2282 .
[0032] Buffer storing of the nominal length grade A lumber may be at a well known buffer storage location (not shown) along the continuous input-to-output fabrication path CP. It may be utilized while grade B-N lumber is in-fed at the grade selective in-feeding stage, which further includes a stack jump rollcase 2284 for alternately receiving nominal length grade A lumber from stack crossover rollcase 2281 or from stack in-feed deck 2283 . Pull cart stacked boards may be manually in-fed from stack in-feed 2287 onto a singulation station at which the lumber may be held back temporarily while single grade shortened pieces are in-fed via sixth fork lift access 2280 , pallet dumper 2289 and spreader conveyor 2288 .
[0033] The lumber sorter 222 , stack jump rollcases 2263 , 2284 , stack cross over roll case, singulation station 2286 and short piece conveyor 2288 with pallet dumper 2289 are computer controlled switching gates that provide together with buffer storage along the individual paths CP, SP, TP in between the switching gates for real time grade switching with substantially uninterrupted extended length lumber fabrication.
[0034] The grade selective in-fed lumber pieces are transported towards a lumber length extension stage including a well known profile machine where the ends of the lumber pieces are machined for finger jointing. The lumber length extension stage further includes well known components such as an assembler conveyor 2304 , crowder 2305 , curing station 2306 , retarder 2307 , a proof loader 232 and a travel saw 234 . An incline chain deck 2302 and a corner feeder 2303 transport the lumber between the profile machine 2301 and the assembler conveyor 2304 .
[0035] The endless lumber string propagating out of the curing station 2306 passes through the proof loader 232 , where finger joint testing is performed in accordance with well known finger joint test criteria. Finger joint failure information is passed onto the travel saw 234 for a computerized controlled out-cutting of failed finger joints in accordance with the finger joint failure information. Failed finger joint portions as well as grade transitions are kept at a minimum length of preferably about 1 foot for out-sorting at sweep table 2344 and reinsertion via seventh fork lift access 2345 and second fork lift access 2102 via reject back insertion path RP. The travel saw 234 also cuts the endless lumber string into extended length lumber of preferably 66 feet length, which is diverted by the sweep table 2344 towards a second lumber grader 236 and a paddle stacker 2381 . There, the extended length lumber is stacked and transported away via eight fork lift access 2382 . The second lumber grader may be similar to the first lumber grader 2162 .
[0036] In a further embodiment of the invention, a single lumber graded is utilized instead of two lumber graders 2162 and 236 . Consequently, the continuous input-to-output fabrication path CP crosses at the first raw lumber grading stage coinciding with the second extended length lumber grading stage.
[0037] In FIG. 5 , a wooden truss joist 300 has top chords 301 , bottom chords 302 and web struts 303 . Chords 301 , 302 and/or struts 303 may be fabricated from extended length graded lumber fabricated as above described and/or in accordance with the above described fabrication system 200 .
[0038] Accordingly, the scope of the invention described in the specification and figures is set forth by the following claims and their legal equivalent: | An extended length graded lumber fabrication system features a number of fabrication stages along a substantially continuous fabrication path providing high through put fabrication of graded lumber of extended length from low quality raw lumber. The fabrication stages include reject recognition stages, a supply lumber grading stage, a finger jointing stage and a final grading stage for the extended length lumber. The fabrication system is configured in conjunction with the particularities of low quality raw lumber to minimize grade fluctuations, increase grade bandwidth and minimize raw lumber waste during fabrication of extended length graded lumber, which may be used in wooden truss joists. The use of low quality raw lumber cut from small diameter tree trunks is environmentally beneficial. It contributes to preserve old growth and to use lighter and environmentally less invasive timber harvesting machinery and techniques. | 4 |
This application is a continuation of application Ser. No. 08/389,944 filed Feb. 17, 1995 abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a disk-loading apparatus for moving an optical playback means or the like such as an optical pickup toward and away from a disk placed on a tray. More particularly, this invention relates to a disk-loading apparatus having a main chassis and a subchassis which rotates about pivots extending in the same axial direction as pivot-receiving openings in an extending portion of the main chassis, to facilitate assembly.
BRIEF DESCRIPTION OF THE RELEVANT ART
A CD player, for example, is equipped with a disk-loading apparatus for moving an optical pickup or turntable toward and away from a disk placed in its closed position, or play position, on a tray. This disk-loading apparatus comprises, for example, a subchassis and a cam member. One end of the sub-chassis is rotatably mounted to a main chassis that is the body of the player, the other end of the sub-chassis being swingable up and down. The cam member swings the other end of the sub-chassis up and down.
FIG. 1 is a view illustrating a method of mounting the prior art disk-loading apparatus to the main chassis of a CD player. In shown in the figure, a sub-chassis 100 includes a pair of axially oppositely-directed pivots 100a for rotation of the sub-chassis about the pivots 100a. The pivots 100a are formed at the top and bottom ends of the upper right portion of the sub-chassis 100. A main chassis 101 includes a pair of bearing portions 101a for rotatably supporting the pivots 100a of the sub-chassis 100. The bearing portions 101a of the main chassis 101 are formed to mate with the pivots 100a at the upper right portion of the sub-chassis 100. The bearing portions 101a are open at their mutually-opposed inner sides and at their respective top sides for receiving therein the axially oppositely-directed pivots 100a of the subchassis 100. The main chassis 101 also defines an opening 101b for receiving the sub-chassis 100 when in its pivotally downward position. The sub-chassis 100 includes a forwardly-extending protrusion 100b formed on the leftmost forward portion of the subchassis 100 as viewed in FIG. 1.
A cam member 102 is mounted to the left side of the main chassis 101 as viewed in FIG. 1 The cam member 102 includes a cam groove 102a in engagement with a protrusion 100b formed at the left end of the sub-chassis 100. An optical pickup 106 and a turntable 107 are supported by the sub-chassis 100 and positioned to rotate a disk placed on the turntable 107 for sensing data from the disk by the optical pickup 106.
The sub-chassis 100 is mounted to the main chassis in the manner which is now described. First, the sub-chassis 100 is made to face an opening 101b in the main chassis 101. Under this condition, the protrusion 100b on the sub-chassis 100 is inserted into the cam groove 102a in the rotating cam 102. Then, the pivots 100a of the sub-chassis 100 are caused to fall into the bearing portions 101a in the main chassis 101 from a position above the bearing portions 101a. Thereafter, washers 103 and screws 104 are respectively mounted on each of the bearing portions 101a to prevent the sub-chassis 100 from disengaging from the main chassis 101. A gear 105 for rotating the cam member 102 is then mounted on the cam member 102.
FIG. 2 thus shows the condition in which the sub-chassis 100 is mounted in the main chassis 101 according to the assembly steps previously described. Under the illustrated condition, rotation of the gear 105 rotates the rotating cam member 102. The protrusion 100b on the subchassis 100 thus moves vertically along the cam groove 102a in the rotating cam member 102 when the cam member 102 is rotating. The right end of the sub-chassis 100 as viewed in FIG. 2 is rotatably held to the main chassis 101 by the pivots 100a mating with the bearing portions 101a. Therefore, rotation of the rotating cam member 102 causes the sub-chassis 100 to swing in an upwardly and downwardly direction as viewed in FIG. 2. Thus, the optical pickup 106 and the turntable 107 mounted to the sub-chassis 100 are also capable of moving toward and away from a disk placed in position on a tray 108 on the main chassis 101, as seen in FIG. 2.
The apparatus shown in FIGS. 1 and 2 has presented some difficulties in that the above-described disk-loading apparatus needs the washers 103 and the screws 104 when mounting and pivotally securing the sub-chassis 100 to the main chassis 101 because of the structure of the apparatus. Therefore, this disk-loading apparatus has a problem in involving an extra step for mounting the washers 103 and the screws 104. Furthermore, the number of components of this disk-loading apparatus is increased because of the presence of the washers 103 and the screws 104. These features increase the cost of parts and of their assembly.
BRIEF SUMMARY OF THE INVENTION
In view of the foregoing problems, it is an overall object of the present invention to provide an inexpensive disk-loading apparatus having a sub-chassis which can be easily mounted to a main chassis.
It is an additional object of this invention to provide, in accordance with the teachings of the invention, a disk-loading apparatus having a main chassis for supporting a tray on which a disk is placed and a sub-chassis rotating about shafts, so as to move toward and away from the main chassis, the apparatus being characterized in that rotating portions of the sub-chassis rotatably held by said shafts are moved along said shafts, whereby the rotating portions can be attached to and detached from the main chassis.
Directed to overcoming the problems with the prior art and to achieving the objects of this invention, an apparatus for loading a disk according to the invention has a tray on which the disk is placed; a main chassis for supporting the tray, wherein the main chassis comprises an opening portion, protruding portions protruding toward the opening portion which are respectively formed at a first end of the main chassis, and a pair of support holes formed in the protruding portions which have openings extending in the same direction. A subchassis rotates about pivots so as to move toward and away from the main chassis, which pivots have openings extending in the same direction in which the support holes in the main chassis extend and which are inserted into the support holes.
In the present invention, the sub-chassis preferably has an engaging portion for making engagement with the main chassis. The main chassis has a guide portion for guiding the engaging portion of the sub-chassis. Also, in the present invention, the guide portion of the main chassis preferably forms a cam portion provided with a cam groove. This cam portion is formed with a notch into which the engaging portion engaged in the cam groove is to be inserted. The cam gear has a cam member for swinging a second end of the subchassis up and down and a driving gear for moving the tray, the second end being opposite to the first end. The main chassis further comprises an instralling portion for installing the cam gear and the subchassi further includes an engaging portion of making engagement with the main chassis and the engaging portion is guided by the cam member.
Furthermore, in the present invention, there are provided limiting means for preventing said rotating portions of the sub-chassis from disengaging from the main chassis within a range in which the sub-chassis rotates about the shafts. In addition, in the present invention, the limiting means preferably consist of protruding portions formed on either one of the sub-chassis and the main chassis.
Moreover, in the present invention, a moving means for moving the tray toward the main chassis is preferably formed integrally with the cam portion, and the disk is placed on the tray.
In the operation of the above-described structure, in order to mount the sub-chassis to the main chassis, the sub-chassis is first moved along the axis of its shafts. In this way, the rotating portions of the sub-chassis are mounted to the main chassis via its shafts. Then, the engaging portion of the sub-chassis is inserted into the cam groove via the notch formed in the cam portion while swinging the other end of the sub-chassis toward the main chassis. Under this condition, movement of the sub-chassis along the axis of its shafts is limited by the limiting means and so the rotating portions of the sub-chassis do not disengage from the main chassis. If the limiting means are composed of protrusions formed either on the sub-chassis or on the main chassis, the limiting means can be easily formed integrally with the sub-chassis or the main chassis. Furthermore, if a means for moving the tray is formed integrally with the cam member, then the timing at which the tray is moved can be easily correlated with the timing at which the sub-chassis is swung, owing to the shape of the cam groove.
These and other features of the invention will be seen from a detailed review of this written description of the invention, taken with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view illustrating the manner in which a prior art disk-loading apparatus is mounted to the main chassis of a CD player;
FIG. 2 is an expanded perspective view of main portions of the CD player shown in FIG. 1;
FIG. 3 is an exploded perspective view of main portions of a CD player incorporating a disk-loading apparatus forming a preferred embodiment of the invention;
FIG. 4 is a diagrammitic, transparent plan view of the CD player shown in FIG. 3, showing a path along which power is transmitted to a cam gear;
FIG. 5 is a cross-sectional, side elevational view of FIG. 4;
FIG. 6 is an expanded view of the cam groove in the cam gear of FIGS. 2 to 4;
FIG. 7 is a transparent plan view of the CD player shown in FIG. 3, and in which the disk tray is in its open position;
FIG. 8 is a top diagrammatic plan view of the disk-loading apparatus of the invention, also shown in its open position Q1, with greater detail than in FIG. 7;
FIG. 9 is a top diagrammatic plan view of the disk-loading apparatus of the invention, similar to FIG. 8, but shown in its closed or standby position (Q2);
FIG. 10 is a top diagrammatic plan view of the disk-loading apparatus of the invention, similar to FIGS. 8 and 9, but shown in its playback position (Q3) in which the front side of the subchassis is raised; and
FIG. 11 is a side elevation in cross-section of FIG. 7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment of the invention is hereinafter described in detail with reference to FIGS. 3 to 11. Since an embodiment described below is a preferred specific example of the invention, various technically preferred limitations are imposed. However, the scope of the invention is not limited to these aspects unless otherwise specifically stated below.
FIG. 3 is an exploded perspective view of main portions of a CD player incorporating a disk-loading apparatus embodying the present invention. In FIG. 3, a main chassis is generally indicated by the reference numeral 1. As clearly shown in this figure, the main chassis 1 is centrally provided with an open portion 1a in the main chassis and also with an essentially cylindrical or well-shaped recessed portion 1b at the left (or front) side of the main chassis, as viewed in the figure. The well-shaped recessed portion 1b accommodates a cam gear 2. The main chassis 1 also includes a spindle-like protruding portion 1c which is formed in the center of the recessed portion 1b which mates with and rotatably supports the cam gear 2. The main chassis also includes a vertically-extending insertion opening portion 1d formed in a wall portion between the recessed portion 1b and the opening 1a in the main chassis 1. The main chassis further defines a pair of inwardly-directed, spaced-apart, protruding portions 1g protruding toward the opening 1a which are formed at the right (or rear) end of the main chassis 1 as viewed in the figure. A pair of support holes 1e for mounting a sub-chassis 3 are formed in the protruding portions 1g. The support holes 1e have openings extending in a direction indicated by the arrow A1, or transverse to the forward and rearward (left and right) directions.
The main chassis also includes a limiting protrusion 1f which is formed on the main chassis 1 near one of the support holes 1e. The protrusions 1f protrudes a given amount into the opening portion 1a in the direction A2.
A cam gear 2 is provided for swinging the left side (as viewed in the figure) of the sub-chassis 3 vertically relative to the main chassis 1. A driving gear 2a is provide for moving a tray 4 in the direction B1 indicated by the arrow B and is formed integrally with the cam gear 2. More specifically, the driving gear 2a for moving the tray 4 is formed on the upper side of the cam gear 2. A cam groove 2b for swinging the sub-chassis 3 up and down, as viewed in the figure, is formed in the lower outer surface of the cam gear 2 and is arranged to engage with a cam follower type of protrusion 3b on the sub-chassis 3 which protrudes forwardly from a front portion of the sub-chassis 3 as seen in the figure.
As best shown in FIG. 6, the cam groove 2b comprises a lower step portion S1, an upper step portion S2, and an oblique of transition portion S3 connecting the lower step portion S1 and the upper step portion S2. The lower step portion S1 is longer than the upper step portion S2. A notch 2c in the cam gear 2 for introducing the protrusion 3b on the subchassis 3 into the cam groove 2b from below is formed in the bottom wall of the lower step portion S1 that is located immediately under the upper step portion S2 of the cam groove 2b.
On the other hand, as shown in FIG. 3, a pair of pivots 3a protruding in the direction A2 of the arrow A are formed at the right end of the sub-chassis 3. These pivots 3a each extend (viz., point) in the same axial direction A2, in contrast to the oppositely-directed pivots 100a shown in FIG. 1. The protrusion 3b which protrudes in the direction indicated by the arrow B1 is formed at the left end of the sub-chassis 3 and as will be appreciated from FIGS. 3 and 5, extends through a slot (no numeral) formed in the wall of the well-like recessed portion 1b, to operatively engage with the cam groove 2b. The sub-chassis 3 is centrally provided with an opening 3c.
A support base 5 for mounting a turntable 6 and an optical pickup 7 (see FIG. 7) is mounted to the bottom surface of the sub-chassis 3 so as to face the opening 3c in the sub-chassis 3. The support base 5 is secured to the sub-chassis 3 via vibration insulators 8, springs 9 and screws 10.
The disk-loading apparatus is composed of the cam gear 2 and the sub-chassis 3. The tray 4 moves on the main chassis 1 in the direction B1 of the arrow B to move the disk which is placed on the top surface of the tray 4, into an open position P1 shown in FIGS. 7 and 11 or into a closed position P2 shown in FIGS. 9 and 10.
As shown in FIG. 3, a concave disk placement portion or recess 4a is formed in the center of the movable tray 4. A slot 4b extends from the center of the disk placement portion 4a toward the main chassis 1. When the tray 4 is in the closed position P2, the slot 4b allows the turntable 6 and the optical pickup 7 to face the disk D (see FIG. 11) on the tray 4. As shown, the turntable 6 and the pickup 7 are mounted to the sub-chassis 3 via the support base 5 (FIG. 3).
An electric motor 11, a first gear 12, and a second gear 13 are also mounted on the main chassis 1. AS shown in FIGS. 4 and 5, the rotational force of the motor 11 is transmitted from an output gear 11a of the motor 11 to the first gear 12. The rotational force is then transmitted from the first gear 12 to the second gear 13 and then to the cam gear 2 which includes the cam groove 2a.
A gate-shaped chucking beam 14 is transversely mounted on top of the main chassis 1. A chucking pulley 15 is rotatably mounted to the bottom surface of the chucking beam 14.
The procedure for mounting the sub-chassis to the main chassis 1 of the disk-loading apparatus is described below.
As shown in FIG. 3, the cam gear 2 is first inserted into the recessed portion 1b in the main chassis 1. The central portion of the cam gear 2 is positioned and held by the protruding portion 1c. Subsequently, a screw 16 (see FIG. 3) is screwed into the main chassis 1 via the cam gear 2 to secure the cam bear 2 to the protruding portion 1d. The cam gear 2 thus is rotatably secured to the main chassis 1. In this case, the notch 2c in the cam gear 2 is made to face the vertically-extending insertion opening 1d in the main chassis 1, as best seen in FIGS. 3 and 5.
The motor 11 with its output gear 11a, the first gear 12, and the second gear 13, as best seen in FIGS. 4 and 5, are mounted to the main chassis 1 prior to the mounting of the cam gear 2, as described above. Thereafter, the sub-chassis 3 is inserted into the opening portion 1a from below the main chassis 1 while causing the pivots 3a to face upward. The axis of the pivots 3a is brought into agreement or coincidence with the axis of the support holes 1e in the main chassis 1. Under this condition, the sub-chassis 3 is moved horizontally (viz., laterally) in the direction of A2 shown in FIG. 3, that is, in the same axial direction as the pivots 3a and coincidentally along the same axis. Then, the pivots 3a are inserted into the support holes 1e in the projecting portions 1g of the main chassis 1. One end of the sub-chassis 3, i.e. the right end as seen in FIG. 3, is thus is rotatably held to the main chassis 1.
Thereafter, the other end, i.e. the left end as seen in FIG. 3, of the sub-chassis 3 is rotated upward. The protrusion 3b is inserted into the recessed portion 1b in the main chassis 1 through the insertion opening 1d in the main chassis 1. In this case, the notch 2c in the cam gear 2 is located on the side of the insertion opening 1d in the main chassis 1 and so the protrusion 3b on the sub-chassis 3 is inserted into the cam groove 2b in the cam gear 2. The cam gear 2 is then slightly rotated to place the protrusion 3b formed on the sub-chassis 3 in a start position Q1 shown in FIG. 6.
Under this condition, the operation for mounting the sub-chassis 3 to the main chassis 1 is completed. Also, under this condition, movement of the sub-chassis 3 along the axis of the pivots 3a is restricted by the limiting protrusions 1f on the main chassis 1. That is, once the sub-chassis 3 is mounted to the main chassis 1, the sub-chassis does not come out of engagement with the main chassis 1. In this case, the protrusion 3b on the subchassis 3 is in engagement with the lower step portion S1 in the cam groove 2b shown in FIG. G. Therefore, one end of the sub-chassis 3 is tilted downward with respect to the other end, as shown in FIG. 11.
The support base 5, the turntable 6, the optical pickup 7, and other components may be mounted to the sub-chassis 3 either before or after the sub-chassis 3 is mounted to the main chassis 1. The tray 4 is mounted to the main chassis 1 when the tray is in the open position P1. In this case, the cam gear 2, for example, is brought into mesh with a rack (as shown in FIG. 8) formed on the bottom surface of the tray 4 without rotating the gear 2.
In this way, in this disk-loading apparatus, the subchassis 3 can be mounted to the main chassis without using washers or screws, as in FIGS. 1 and 2 of the prior art. Therefore, the sub-chassis 3 can be mounted easily. Hence, the number of assembly steps can be reduced.
FIGS. 8 to 10 clarify the positioning of the disk tray 4 for the open position Q1 (FIG. 8), the closed, standby position Q2 (FIG. 9), and the playback position (FIG. 10), wherein the front side of the sub-chassis 3 is in a raised position. The positions Q1, Q2, and Q3 are correlated with the movement of the protrusion 3b in the cam groove 2b from the lower step portion S1 through the oblique or transition portion S3 to an upper step portion S2, as seen in FIG. 6.
Furthermore, the disk-loading apparatus according to the invention dispenses with the need for washers and screws, thus reducing the number of components. This, in turn, lowers the cost of the apparatus. Moreover, in this disk-loading apparatus, variations in quality attributable to tightening screws, i.e., floating of screws, screw induced cracks, and similar phenomena, do not occur. In consequence, the quality of the apparatus is stable and the reliability of the apparatus can be enhanced.
Further, in this disk-loading apparatus, the limiting means for preventing the sub-chassis 3 from disengaging from the main chassis 1 can be made of the limiting protrusions 1f that are parts of the main chassis 1, i.e., simple structures. This can facilitate manufacturing the limiting means. The limiting means may also be formed on the sub-chassis 3.
The operation of the CD player, mainly the operation of the disk-loading apparatus, is now described. When the tray 4 is in the open position P1 shown in FIGS. 7 and 11, if the motor 11 is rotated in a forward direction, the cam gear 2 rotates in the direction indicated by the arrows in FIGS. 5 and 6. The tray 4 is brought into the closed position P2 shown in FIGS. 7 and 10.
In this case, the protrusion 3b on the sub-chassis 3 is brought into the standby position Q2 located immediately before the oblique portion S3 of the lower step portion S1 of the cam groove 2b, as shown in FIG. 6. Then, the motor 11 rotates forwardly. The protrusion 3b on the sub-chassis 3 is placed in position on the upper step portion S2 (hereinafter referred to as the playback position Q3) through the oblique portion S3 in the cam groove 2b from the standby position Q2 shown in FIG. 6.
Therefore, as, the sub-chassis 3 is raised from the tilted position shown in FIG. 11, and the disk D lying on the disk placement portion 4a of the tray 4 is raised by the turntable 6. The disk D is urged toward the chucking pulley 15 by the turntable 6 and so the disk is rotated with the pulley 15 by rotation of the turn-table 6. When the sub-chassis 3 assumes its horizontal position, the optical pickup 7 is placed in position close to the disk D. Therefore, as the disk D turns, information in the disk D is optically read by the optical pickup 7.
When the protrusion 3b on the sub-chassis 3 is moving from the standby position Q2 to the playback position Q3, the tray 4 does not move, because the cam gear 2 is not in mesh with the rack of the tray 4. When the playback of the disk D ends, the motor 11 is reversed. The protrusion 3b on the sub-chassis 3 moves from the playback position Q3 to the standby position Q2. Consequently, the front side of the sub-chassis 3 is tilted downward as shown in FIG. 11. The turntable 6 and other components are pulled downward. As a result, the disk D is placed on the disk placement portion 4a of the tray 4. If the motor 11 is rotated in reverse, the protrusion 3b moves through the lower step portion S1 of the cam groove 2b from the standby position Q2 toward the start position Q1 while the front side of the sub-chassis 3 remains tilted downward.
When the protrusion 3b on the sub-chassis 3 arrives at the start position Q1, the tray 4 is placed in the open position P1, where the tray has been driven out of the main chassis 1. For this reason, if the tray 4 is located in the open position P1, the protrusion 3b on the sub-chassis 3 does not disengage from the notch 2c in the cam groove 2b. In this way, in this disk-loading apparatus, the cam gear 2 for swinging the sub-chassis 3 is also capable of moving the tray 4. In consequence, the timing at which the tray 4 is moved and the timing at which the sub-chassis 3 is swung can be easily determined.
As described thus far, according to the present invention, an inexpensive disk-loading apparatus having a sub-chassis which can be readily mounted to the main chassis is provided. | A sub-chassis is readily mounted on a main chassis by pivot shafts (3a) which can be axially inserted into pivot support bores formed in the main chassis (1). A cam member (2) is provided with a cam groove (2b) for inducing vertical pivotal movement of the sub-chassis (3). The sub-chassis (3) has an engaging portion (3b) which is engaged in a cam which has a cam groove (2b). The cam is provided with a notch (2c) via which the engaging portion (3b) of the sub-tray (3) can enter the cam groove. A limiting projection 1f is provided which prevents the shafts (3a) of the sub-tray (3) from disengaging from the main chassis (1) while the sub-chassis is pivoting within an operative range. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/146,467, filed on Jan. 22, 2009, the disclosure thereof incorporated by reference herein in its entirety.
BACKGROUND
The present disclosure relates generally to integrated circuits. More particularly, the present disclosure relates to countering security threats created by manipulation of the power supply rails of the integrated circuit.
An increasing number of devices include a system-on-a-chip (SOC), which is a single integrated circuit (chip) that includes a processor, volatile memory, and other components. During operation, the volatile memory may contain secure information such as security algorithms, unencrypted data, cryptographic keys, and the like. A hacker who has gained possession of such a device could gain access to the secure information by manipulating the voltage of the power supply provided to the SOC. For example, the hacker could increase the work load, which would cause the processor of the SOC to increase its operating frequency and voltage. The hacker could then suddenly reduce the voltage, causing the processor to hang because the voltage is insufficient to support the high operating frequency. Once the processor hangs, the hacker could gain access to the secure information in the non-volatile memory by a variety of methods, for example by using a test access port such as a Joint Test Action Group (JTAG) port.
SUMMARY
In general, in one aspect, an embodiment features an integrated circuit comprising: a power supply terminal configured to receive electrical power; a core circuit powered by the electrical power, wherein the core circuit comprises a volatile memory configured to store data; a clock source configured to provide a clock signal at a selected frequency, wherein the selected frequency is one of a plurality of possible frequencies of the clock signal, and a processor configured to operate according to the clock signal; and a security circuit configured to reset the core circuit based on the selected frequency of the clock signal and a voltage of the power supply terminal, wherein resetting the core circuit clears the data from the volatile memory.
Embodiments of the integrated circuit can include one or more of the following features. Some embodiments comprise a non-volatile memory configured to store a plurality of performance points, wherein each performance point associates one of a plurality of voltage ranges with one of the possible frequencies of the clock signal; wherein the security circuit resets the core circuit based on a performance point corresponding to the selected frequency of the clock signal. In some embodiments, the security circuit comprises: an analog-to-digital converter configured to provide a voltage number based on the voltage of the power supply terminal; a control circuit configured to assert a first error signal when the voltage of the power supply terminal is below the voltage range associated with the selected frequency of the clock signal; and a reset circuit configured to assert a reset signal when the first error signal is asserted; wherein the core circuit is reset when the reset signal is asserted. In some embodiments, the analog-to-digital converter asserts a second error signal when the voltage of the power supply terminal is below an operating range of the analog-to-digital converter; and the reset circuit asserts the reset signal when the second error signal is asserted.
In general, in one aspect, an embodiment features a method comprising: receiving electrical power at a power supply terminal of an integrated circuit; generating a clock signal within the integrated circuit; storing data in a volatile memory of the integrated circuit; processing the data according to the clock signal; determining a clock frequency of the clock signal; determining a voltage of the power supply terminal; and clearing the data from the volatile memory based on the clock frequency and the voltage.
Embodiments of the method can include one or more of the following features. In some embodiments, clearing the data from the volatile memory comprises: disconnecting the volatile memory from the power supply terminal based on the clock frequency and the voltage. In some embodiments, disconnecting the volatile memory of the integrated circuit from the power supply terminal comprises: determining an allowed voltage range for the clock frequency of the clock signal; and disconnecting the volatile memory from the power supply terminal of the integrated circuit when the voltage of the power supply terminal is below the allowed voltage range. Some embodiments comprise informing a processor of the integrated circuit when the voltage of the power supply terminal is above the allowed voltage range.
The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
FIG. 1 shows elements of a SOC device according to some embodiments.
FIG. 2 shows a state machine for the SOC device of FIG. 1 according to some embodiments.
FIG. 3 shows a process for the device of FIG. 1 according to some embodiments.
The leading digit(s) of each reference numeral used in this specification indicates the number of the drawing in which the reference numeral first appears.
DETAILED DESCRIPTION
Embodiments of the present disclosure provide elements of a system-on-a-chip (SOC) capable of countering security threats created by manipulation of the power supply rails of the SOC. FIG. 1 shows elements of a SOC device 100 according to some embodiments. Although in the described embodiments, the elements of SOC device 100 are presented in one arrangement, other embodiments may feature other arrangements. For example, elements of SOC device 100 can be implemented in hardware, software, or combinations thereof.
Referring to FIG. 1 , SOC device 100 includes an SOC 102 powered by a power supply 104 . In particular, SOC 102 includes a power supply terminal 108 to receive electrical power 106 from power supply 104 . In FIG. 1 , the path of electrical power 106 is shown as a dotted line for clarity. SOC 102 includes a core circuit 110 and a security circuit 112 . Both core circuit 110 and security circuit 112 are powered by electrical power 106 . SOC 102 is implemented as a single integrated circuit. Device 100 can be any sort of device.
Core circuit 110 includes a volatile memory 114 , a processor 116 , and a core clock source 118 to provide a core clock signal cck that is used by the elements of core circuit 110 . Volatile memory 114 is connected to power supply terminal 108 by one or more memory power supply switches 122 . Processor 116 is connected to power supply terminal 108 by one or more processor power supply switches 124 .
Security circuit 112 includes a clock frequency circuit 120 , an analog-to-digital converter (ADC) 126 , a non-volatile memory 132 , a control circuit 136 , a reset circuit 140 , an OR gate 142 , and a secure clock source 128 to provide a secure clock signal sck that is used by the elements of security circuit 112 . In some embodiments, secure clock source 128 is completely internal to SOC 102 to prevent access by a hacker.
Clock frequency circuit 120 determines the clock frequency of core clock signal cck, and provides a clock frequency signal ckfreq representing the clock frequency. Clock frequency circuit 120 can determine the clock frequency of core clock signal cck by direct measurement, by receiving a measurement from core clock source 118 , or the like.
ADC 126 includes a voltage reference (VREF) circuit 148 and a voltage monitor circuit 150 , which are enabled by a voltage reference enable signal vr_en and a voltage monitor enable signal vm_en, respectively. Voltage reference circuit 148 provides a reference voltage to voltage monitor circuit 150 . Voltage monitor circuit 150 monitors the voltage of power supply terminal 108 based on the reference voltage.
ADC 126 can be implemented as a saturating-type ADC or the like. That is, ADC 126 saturates at a minimum voltage value. When the voltage of power supply terminal 108 is within the operating range of ADC 126 , and ADC 126 receives a sample signal smpl from control circuit 136 , ADC 126 provides a voltage number signal vnum that represents the voltage of power supply terminal 108 . But when the voltage of power supply terminal 108 is below the operating range of ADC 126 , ADC 126 provides an asynchronous low-voltage error signal vlt 2 lo . In some embodiments, ADC 126 has a full-scale measurement range of 0.6V-1.22V, a resolution of 6 bits (64 quantization levels), a voltage resolution of 9.84 mv, a startup time less than 20 microseconds, and a sample conversion time less than 20 microseconds. In some embodiments, ADC 126 has other parameter values.
Non-volatile memory 132 can be implemented as a content-addressable memory or the like. Non-volatile memory 132 stores a plurality of performance points 134 . Each performance point 134 associates a respective allowed voltage range with each of a plurality of possible frequencies of core clock signal cck. For example, a performance point might associate a clock frequency of 624 MHz with an allowed voltage range of 1.1V-1.3V. Performance points 134 can be determined empirically for each SOC 102 individually, and then programmed into non-volatile memory 132 before sale. Non-volatile memory 132 provides a performance point data signal ppd representing performance points 134 . Non-volatile memory 132 also provides a voltage monitoring enable signal en_vlmn to enable or disable voltage monitoring, for example in order to debug SOC 102 .
Reset circuit 140 asserts a global watchdog reset signal gbl_wdg_rst based on error signals err_wdg and vlt 2 lo . In particular, OR gate 142 provides a logical OR of error signals err_wdg and vlt 2 lo to reset circuit 140 , which asserts reset signal gbl_wdg_rst when either error signal err_wdg or vlt 2 lo is asserted. Reset signal gbl_wdg_rst controls power supply switches 122 , 124 , as described in detail below. The duration of global watchdog reset signal gbl_wdg_rst is set to allow volatile memory 114 of core circuit 110 to clear before power is restored. In FIG. 1 , the path of reset signal gbl_wdg_rst is shown as a dashed line for clarity.
In some embodiments, control circuit 136 provides signals bg_en, vm_en, smpl, and err_wdg based on signals ckfreq, en_vlnm, ppd, and vnum according to a state machine. FIG. 2 shows a state machine 200 for SOC device 100 of FIG. 1 according to some embodiments. Although in the described embodiments, the elements of state machine 200 are presented in one arrangement, other embodiments may feature other arrangements. For example, in various embodiments, some or all of the states of state machine 200 can be executed in a different order, concurrently, and the like.
Referring to FIG. 2 , state machine 200 begins in an idle state IDLE. State machine 200 starts automatically when power is applied to SOC 102 unless disabled by programming a predetermined bit in non-volatile memory 132 , which causes the en_vlmn signal to be negated. State machine 200 continues to function until disabled by processor 116 through a secure thread.
After a configurable idle time, state machine 200 transitions to a voltage reference enable state VR_ENA, where voltage reference enable signal vr_en is asserted, thereby enabling voltage reference circuit 148 . State machine 200 then transitions to a voltage reference stable state VR_STBL, where state machine 200 remains for an interval sufficient to allow voltage reference circuit 148 to stabilize.
State machine 200 then transitions to a voltage monitor enable state VM_ENA, where voltage monitor enable signal vm_en is asserted, thereby enabling voltage monitor circuit 150 . State machine 200 then transitions to a voltage monitor stable state VM_STBL, where state machine 200 remains for an interval sufficient to allow voltage monitor circuit 150 to stabilize.
State machine 200 then transitions to a voltage sample state SMPL, where voltage sample signal smpl is asserted, thereby causing voltage monitor circuit 150 to sample the voltage of power supply terminal 108 . In response, voltage monitor circuit 150 returns voltage number signal vnum representing the voltage of power supply terminal 108 .
State machine 200 then transitions to a compare state COMPARE, where the value of voltage number vnum is compared to the allowed voltage range for the performance point 134 for the current clock frequency. The current clock frequency is represented by clock frequency signal ckfreq. If the comparison shows the value of voltage number vnum is within the allowed voltage range, indicating normal operation of core circuit 110 , then state machine 200 transitions to a wait state WAIT.
If the comparison shows the value of voltage number vnum is below the voltage range, indicating a possible attack, then state machine 200 transitions to an error watchdog state ERR_WDG, where control circuit 136 asserts error watchdog signal err_wdg, thereby causing reset circuit 140 to assert global watchdog reset signal gbl_wdg_rst. In response to global watchdog reset signal gbl_wdg_rst, power supply switches 122 and 124 disconnect volatile memory 114 and processor 116 , respectively, from power supply terminal 108 . After a predetermined interval that is sufficient to allow the data stored in volatile memory 114 to clear, reset circuit 140 negates global watchdog reset signal gbl_wdg_rst. In response, power supply switches 122 and 124 re-connect volatile memory 114 and processor 116 , respectively, to power supply terminal 108 . State machine 200 then transitions to wait state WAIT.
If the comparison shows the value of voltage number vnum is above the voltage range, indicating that the voltage of power supply terminal 108 is unnecessarily high, then state machine 200 transitions to a high-voltage error state VLT 2 HI, where control circuit 136 asserts an interrupt signal int, causing an interrupt to processor 116 of core circuit 110 . In response, processor 116 can reduce the voltage of power supply 104 . State machine 200 then transitions to wait state WAIT.
State machine 200 remains in wait state WAIT for a predetermined wait interval. The wait interval should be long enough to allow the voltage of power supply 104 to change, for example in response to a command from processor 116 . The wait interval can be extended to reduce the power consumed by security circuit 112 . If voltage monitoring has not been disabled by processor 116 , state machine 200 returns to voltage sample state SMPL.
However, if at wait state WAIT, voltage monitoring has been disabled by processor 116 , state machine 200 transitions to a voltage monitor disable state DIS_VM, where voltage monitor enable signal vm_en is negated, thereby disabling voltage monitor circuit 150 . State machine 200 then transitions to a voltage reference disable state DIS_VR, where voltage reference enable signal vr_en is negated, thereby disabling voltage reference circuit 148 . State machine 200 then returns to idle state VR_STBL, where state machine 200 remains until voltage monitoring is again enabled by processor 116 .
FIG. 3 shows a process 300 for device 100 of FIG. 1 according to some embodiments. Although in the described embodiments, the elements of the processes disclosed herein are presented in one arrangement, other embodiments may feature other arrangements. For example, in various embodiments, some or all of the elements of the disclosed processes can be executed in a different order, concurrently, and the like.
Referring to FIG. 3 , at 302 SOC 102 receives electrical power 106 at power supply terminal 108 . At 304 , clock source 118 generates core clock signal cck within SOC 102 . At 306 , volatile memory 114 of core circuit 110 stores data. At 308 , processor 116 processes the data according to core clock signal cck. At 310 , clock frequency circuit 120 of security circuit 112 determines the clock frequency of core clock signal cck. At 312 , ADC 126 determines a voltage of power supply terminal 108 . At 314 , security circuit 112 clears the data from volatile memory 114 based on the clock frequency and the voltage of power supply terminal 108 .
Various embodiments can be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations of them. Embodiments can be implemented in a computer program product tangibly embodied in a machine-readable storage device for execution by a programmable processor; and method elements can be performed by a programmable processor executing a program of instructions to perform functions by operating on input data and generating output. Embodiments can 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. Each computer program can 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 can be a compiled or interpreted language. Suitable processors include, by way of example, both general and special purpose microprocessors. Generally, a processor will receive instructions and data from a read-only memory and/or a random access memory. Generally, a computer will include one or more mass storage devices for storing data files; such devices include magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; and optical disks. Storage devices suitable for tangibly embodying computer program instructions and data include all forms of non-volatile 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 can be supplemented by, or incorporated in, ASICs (application-specific integrated circuits).
A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the scope of the disclosure. Accordingly, other implementations are within the scope of the following claims. | One embodiment, having a corresponding method, features an integrated circuit comprising: a power supply terminal configured to receive electrical power; a core circuit powered by the electrical power, wherein the core circuit comprises a volatile memory configured to store data; a clock source configured to provide a clock signal at a selected frequency, wherein the selected frequency is one of a plurality of possible frequencies of the clock signal, and a processor configured to operate according to the clock signal; and a security circuit configured to reset the core circuit based on the selected frequency of the to clock signal and a voltage of the power supply terminal, wherein resetting the core circuit clears the data from the volatile memory. | 6 |
TECHNICAL FIELD
[0001] This invention pertains to metal detectors, particularly those that transmit time-varying magnetic fields to induce eddy currents in both ferrous and non-ferrous metallic targets, then detect the magnetic fields concomitant with the induced eddy currents.
BACKGROUND OF THE INVENTION
[0002] Over many decades there have been improvements in the performance of metal detectors that transmit time-varying magnetic fields to illuminate sought targets. One motive for improvement is the desire for greater sensitivity to a greater range of targets. To this end, improvements such as higher dynamic range in the receive electronics, improvement in the ability to reject the signal from mineralised ground and increased sensitivity to smaller targets have been developed. At various times, an improvement has exposed deficiencies in aspects of the detector other than the electronics.
[0003] This invention deals with a deficiency in the design of coils, or sensing heads, of metal detectors. It has application in both continuous wave (CW) and pulse induction (PI) detectors.
[0004] The principle of detection of electrically conductive targets with a metal detector is that the detector transmits a time-varying magnetic field which induces eddy currents in conductive targets near the transmit (Tx) winding of the sensor head. Any such eddy current produces its own magnetic field that induces a signal in the receive (Rx) winding of the sensor head.
[0005] Any conductive target within range of the Tx field will have eddy currents induced in it. This includes any conductive elements of the sensor head.
[0006] It seems natural to suppose that small targets are harder to detect with metal detectors, than larger targets because they intercept less of the Tx field and, therefore, reflect less energy to the Rx winding. It is true that they generally do reflect less energy, but it is not only because of their lesser spatial cross-section; the degree to which a target accommodates and re-radiates the Tx field also depends upon the relationship between the frequency components of the Tx field and the dominant time constants (TC) of decay of eddy currents in the target, the “spectral cross-section” of the target in the Tx field.
[0007] The rates at which the induced eddy currents of targets decay, the TC, is determined by the shape, size, resistivity and magnetic permeability of the material. For simplicity in this description, the relative magnetic permeability of the targets will be assumed to be equal to one, a reasonable assumption for non-ferrous targets. The general trends for TCs of a target are:
the lesser volume of individual parts of a target produce shorter TCs in eddy currents; the greater the resistivity of the constituent material, the shorter the TCs in eddy currents; thin, widely distributed targets have shorter TCs than compact targets of the same volume.
[0011] The targets with shorter TCs respond better to Tx components of higher frequency, while targets with longer TCs respond better to Tx components of lower frequency. In CW detectors with discrete frequencies of Tx, targets of shorter TC will more readily reflect the Tx field of the higher frequencies.
[0012] In PI detectors, this translates to the delay between the ends of the Tx pulses and the samples taken of the Rx signal; the shorter that delay, the shorter the longest TC that is excluded from contributing to the samples taken of the Rx signal.
[0013] In order to have some chance of consistently detecting small targets with short time constants, such as fine grains of gold or the firing pins of minimum-metal landmines, in a variety of environments, a metal detector must have excellent rejection of ground mineralisation, large dynamic range in the Rx electronics, emit strong high-frequency components in the Tx field and they have the ability to demodulate signals of relatively high frequency as they are reflected by targets.
[0014] As mentioned previously, targets are not the only objects that are within the effective range of the Tx field of the sensor head. By necessity, the windings of a sensor head are made of highly conductive wire, usually copper, and in many coils are soldered to the leads that connect these windings to the control box of the metal detector. These solder joints are usually posited within the sensor head, that is within the Tx field. Through a phenomenon known as the proximity effect, the strands of wire in a winding loop have eddy currents generated in them by the magnetic field that the same winding generates. This interaction is not to be confused with that which generates the emf along the wires in a winding, as in a transformer.
[0015] The problem of eddy currents within the windings of the sensor head is addressed in U.S. Pat. No. 4,890,064. This patent is incorporated by reference in its entirety into this specification. The solution described in U.S. Pat. No. 4,890,064 is to use parallel strands of individually insulated wire whose diameters are small enough to prevent the generation of eddy currents that have TCs long enough to affect, significantly, the detection of sought targets.
[0016] Generally, the Tx and Rx are separate windings. The sensor heads of most detectors have the connection to the control box via a cable emerging from the sensor head with a pin-and-plug connection to be made at the control box. The connections of the windings to the conductors in the cable are often soldered joints located within the sensor head. The conglomerate of solder, winding conductor and cable conductor produces a volume of continuous conductor that can have a TC longer than those of some of the targets being sought with the detector. The signal produced by the joints affects the result of the demodulation of the Rx signal.
[0017] As long as the eddy currents are within conductors that are fixed, spatially, with respect to the windings, they are not noticeable to the user of a “motion” metal detector when the sensor head is motionless. The indicator of a motion detector responds to differences in the received signals and, as long as the magnitudes of the synchronous eddy currents are the same from one Tx cycle to the next, there is nothing for the detector to indicate.
[0018] Even if the sensor head is moving through space, there is not necessarily any reason for the magnitudes of these eddy currents to vary, as the time-varying Tx field affecting them remains substantially of constant magnitude.
[0019] When used over ground, metal detectors often have to deal with the effects of magnetic ground, that is ground that has a magnetic permeability much greater than 1, and often with complex permeability. These grounds occur in many places around the earth. Gold fields are renowned for having highly magnetic matrix that limits the effective sensitivity of metal detectors used there.
[0020] In such grounds, the signal in the Rx circuit, even when a target is present, is composed almost entirely of signal reflected by the ground, giving the advantage to those detectors with large dynamic range in the Rx electronics and with the ability to identify the signals of the magnetic ground and remove them in order to see the smaller target signal.
[0021] As the sensor head is moved over the ground, variations in the ground produce variations in the reflected field within the sensor head. These variations can be due to spatial variations in the concentration of magnetic material diffused through the matrix, different distances between the surface of the ground and the sensor head due to rough ground or some vertical movement of the sensor head, or changes in the nature of the magnetic permeability of the ground, or the presence of ‘hotrocks’.
[0022] Such effects can produce variations in the magnitudes of the eddy currents of conductive elements within the sensor head from one Tx cycle to the next, producing changing signals in the Rx winding, which will be interpreted by the detector as the detection of a sought target. This is especially true in modern detectors with large dynamic range, the ability to “balance” magnetic ground and sensitivity to targets with short time constants.
[0023] A detector whose Rx processes are adapted to cancel the effect of magnetic viscosity of the ground, be it a CW or PI detector, can suffer the effect described here. The effect is of the conductive elements; the role of the magnetic ground is merely to modulate the intensity of the Tx magnetic field to produce variations in the reflected field irradiating those elements.
SUMMARY
[0024] According to an aspect of the present invention, there is provided a method for improving the sensitivity of a metal detector, the metal detector capable of transmitting transmit magnetic fields and receiving reflected magnetic fields for detecting a target in a ground, the method including:
[0000] identifying at least one electrically conductive element of the metal detector located within the effective ranges of the reflected magnetic fields, wherein an intensity of the reflected magnetic fields, entering the at least one electrically conductive element, changes because of the ground and/or the target, and the said intensity change adversely affects the sensitivity of the metal detector; and
redirecting the said reflected magnetic fields such that the intensity of the said reflected field entering the at least one electrically conductive element is attenuated.
[0025] According to another aspect of the present invention, there is provided a metal detector capable of transmitting transmit magnetic fields and receiving reflected magnetic fields for detecting a target in a ground, including:
[0000] at least one magnetic field redirecting element redirecting the said reflected magnetic fields such that the intensity of the reflected field entering at least one electrically conductive element of the metal detector, the at least one electrically conductive element posited within the effective ranges of the said reflected magnetic fields, is attenuated, wherein
a change of intensity of an un-attenuated reflected field entering the at least one electrically conductive element because of the ground and/or the target, adversely affects the sensitivity of the metal detector.
[0026] In one form, the magnetic field redirecting element is made of a material with a relative magnetic permeability greater than 1.
[0027] In one form, the relative magnetic permeability is a substantially real number over a predetermined range of operational frequencies.
[0028] In one form, the material is ferrite.
[0029] In one form, the metal detector includes a transmit coil for transmitting magnetic fields and a receive coil for receiving reflected magnetic fields; and wherein the at least one magnetic field redirecting element is substantially stationary with respect to the transmit coil and the receive coil.
[0030] In one form, the transmit coil and the receive coil are the same coil.
[0031] In one form, the at least one electrically conductive element of the metal detector is a volume of electrical solder.
[0032] In one form, the at least one electrically conductive element of the metal detector is an electrically conductive portion of an electronic circuit board.
[0033] The effective sensitivity of a metal detector might be reduced if the varying intensity of magnetic field reflected by magnetic matrices induces eddy currents of varying initial magnitudes in conductive components that are within the sensor head of the detector. This invention is a means of reducing the induction of eddy currents in conductive elements of a sensor head.
[0034] The aim of this invention is to remove the effect of small pieces of conductive material, located within or close to the sensor head, being seen as sought targets as the sensor head is moved over magnetic matrix. The means is to surround the conductive material with material with high magnetic permeability and low losses in a time-varying magnetic field, say low-loss ferrite. This will prevent the reflected field from illuminating the conductive material so eddy currents are not generated. The ferrite, with its low losses, responds to the time-varying field, a combination of directly transmitted field and that reflected by the matrix and any targets it contains, with such little loss as to make its response instantaneous as far as the metal detector is concerned. As long as its position with respect to the windings is fixed, it does not temporally modulate the field at any point in space.
[0035] In this invention, the motive is not the preservation of energy for the sake of it; were the Tx field not modulated by external magnetic or conductive matrices to produce variations in the reflected field, the generation of eddy currents in elements of the sensor head would have little effect upon the sensitivity of a motion metal detector.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] FIG. 1 shows some of the elements of a sensor head relevant to this invention.
[0037] FIG. 2 shows the physical relationship between the reflected magnetic field and a solder joint within a sensor head. A stylistic depiction of eddy current is shown, within the body of the solder.
[0038] FIG. 3 shows an end-on, cross-section view of the effect of a tube of material with high magnetic permeability upon some of the field lines of a surrounding magnetic field. Note that the diagram is merely illustrative.
[0039] FIG. 4 depicts the temporal progression of the reflected field from a PI detector as modulated by a changing environment of magnetic material.
DETAILED DESCRIPTION OF THE INVENTION
[0040] FIG. 1 shows a representation of an exemplar of a sensor head for a hand-held motion metal detector. The outer shell ( 1 ) houses the Rx winding ( 2 ), the Tx winding ( 3 ), the shape of which are one of many suitable for their purpose. The two free ends of the windings ( 2 & 3 ) are connected with soldered joints ( 4 & 5 , respectively) to the cables with the lead ( 6 ) that connects the sensor head to the control box (not represented). The windings ( 2 & 3 ) are often made of Litzendraht wire, or at least fine, individually insulated, parallel strands of conductor, in order to prevent the generation of eddy currents with relatively long time constants in the windings, which is a preferred arrangement.
[0041] FIG. 2 shows a representation of a cross-section of a solder joint used within a sensor head. A time-varying magnetic field is represented by the field lines ( 22 ). The cable of the winding in the sensor head is shown ( 23 ), along with the cable to which it is connected ( 24 ) with the solder joint ( 21 ). A stylised representation of an eddy current, induced by the time-varying magnetic field ( 22 ), is shown ( 25 ). The eddy current ( 25 ) depends upon whether the intensity of the applied magnetic field ( 22 ) is increasing, or decreasing, with time, as well as the direction of the field.
[0042] Each strand of the cables ( 23 & 24 ) is coated with an electrical insulator, often a thin skin of polyurethane, reducing the tendency for a detector to see the cables and windings of the sensor head as a target. Where the ends of the winding and cable meet, depicted in FIG. 2 , it is a requirement that the insulation of the individual strands is removed, in order that good electrical connection is made between the two and that the joint is as physically stable as it can be. Thus, the entire volume of the solder joint is one continuous body of electrically conductive metal, allowing the induction of eddy currents of sufficiently long time constant to be seen by a modern metal detector with sensitivity to small targets.
[0043] The detectable metal elements of a sensor head need not be the solder joints just described. Any piece of conductive metal, whether or not it carries an electrical current as part of some circuit, is capable of sustaining eddy currents induced by the reflected magnetic field. Another example of a detectable target might be a small electronic circuit embedded in the sensor head.
[0044] The nature of time-varying Tx fields of metal detectors is cyclic, that is the pattern of transmission is repeated, usually with a fundamental frequency between 100 Hz and 100 kHz. Nominally, the energy transmitted in each cycle is the same as in every other cycle. At any point in space, the magnitude of the magnetic field due to the Tx fields alone will be the same at every instance of an equivalent point in every Tx cycle. Such a field will induce eddy currents within conductive elements under the influence of the field, but the magnitudes of those eddy currents will be identical, from each cycle to the next, if the conductive elements are fixed in space with respect to the windings of the sensor head. Most metal detectors indicate detection only when they detect a difference in the reflected field. A situation in which the time-varying magnetic field, at a conductive element, has the same energy in each cycle will produce eddy currents that have the same magnitude and produce the same energy in their magnetic fields from each cycle to the next. A motion metal detector will not indicate a detection in this situation, given that the receive electronics is not driven into a non-linear state by the magnitude of the receive signals.
[0045] In order for a motion metal detector to indicate a detection due to conductive elements fixed with respect to the windings in its sensor head, there must be at those conductive elements, reflected fields with varying intensity due to the modulation of the time-varying Tx field. Such modulation can occur as the sensor head of an operating metal detector is moved in the vicinity of some material that generates a reflected magnetic field that is synchronous with the field transmitted by the detector. The material can be either electrically conductive, or be magnetic, or both.
[0046] FIG. 3 shows an end-on, cross-section view of the effect of a tube of material with high magnetic permeability upon some of the field lines of a surrounding magnetic field impinging substantially perpendicular to the longitudinal axis of the tube. A time-varying magnetic field 31 is redirected from the space 34 by a shield 33 . There would only be a negligible amount of eddy current induced by the magnetic field 31 in an electrically conductive element 35 posited in space 34 . Even if there is such an eddy current, the magnetic field concomitant with the eddy current would be attenuated by the shield 33 .
[0047] FIG. 4 is a simple graphical representation of a modulated time-varying field (the reflected field) at a point within the influence of the Tx winding. Strictly speaking, the modulation illustrated would have to be due to the influence of a volume of lossless magnetic material, but this invention does not rely on that condition in order to be efficacious.
[0048] The time-varying nature of the magnetic field is cyclic and is represented by the saw-tooth pulses of intensity. The modulation of the time-varying field is represented by the slowly varying amplitude of the pulses.
[0049] A typical situation, in use, where this modulation occurs is when metal detectors are used in fields whose soil or ground has an appreciable magnetic permeability. Such soils are common in, but not exclusive to, goldfields. Variations in the distance between Tx winding and the surface of the soil will effect the modulation; so will spatial variations in the magnetic permeability of the soil as the sensor head is passed over them.
[0050] It is common for magnetic soils or matrices to have a significant contribution through the effect of “magnetic viscosity”. This produces a remanent magnetism in the material after the applied magnetic field has been removed. The negation of the effects upon metal detectors of magnetic viscosity is the subject of much concentrated effort in the development of metal detectors.
[0051] In PI detectors, the decay of remanent magnetism during the receive periods of the Tx cycle induces signals in the Rx winding of a sensor head. If not negated through signal processing, these signals are strong enough to be confused with, or completely obscure, signals from sought targets. In many soils, the magnitude of the field reflected by the ground is orders of magnitude greater, at the sensor head, than the fields reflected by most sought targets. A field of such magnitude has a significant effect upon the magnitude of the nett synchronous magnetic field at the sensor head.
[0052] Again, in the case of PI detectors, the effect of induced eddy currents in elements of the sensor head, while the currents are induced synchronously with the Tx cycle, extends as they decay into the zero-field sections of the Tx cycle, during which time the signals in the Rx winding are processed for evidence of targets. The effect of this is to distort signals that would, otherwise, have been generated by the ground; this adversely affects the ability of a metal detector to negate the effects of magnetic viscosity.
[0053] This invention is a means of attenuating any reflected magnetic field at the conductive elements of a sensor head. This can be achieved by shielding such an element, from the reflected field, with a material with relative magnetic permeability (μr) greater than unity, and the material having a substantially zero imaginary component of its magnetic permeability as compared to the real component, that is, it has very low loss in the frequencies present in the time-varying magnetic Tx field.
[0054] Were the shielding material to have loss, or a complex magnetic permeability, it would, in effect, exhibit magnetic viscosity. Were the rate of decay of the remanent magnetisation of the material slow enough, as it is in mineralised ground, the modulation of the Tx field would produce a reflected field which modulates the magnitude of the remanent magnetisation of the shielding material, inducing a changing signal in the Rx of the metal detector. Any remanent magnetism of the shielding material must be of magnitude, during Rx demodulation periods of a detector, too small to elicit a detection.
[0055] Regardless of all else, the shield must be secured to some element of the sensor head that it is substantially fixed with respect to the windings within the sensor head. The shielding element distorts the Tx field; even small shifts in its relative position can induce detectable signals in the Rx winding.
[0056] In one embodiment of this invention, a suitable material is low-loss ferrite. A tube of ferrite, whose μr>1 (such as 10), can be posited with its longitudinal axis approximately perpendicular to the field lines of the Tx field. The object to be shielded is placed within the hollow of the tube such that its half-way point is approximately at the half-way point of the length of the tube. In this embodiment, the shielding tube should be long enough that the length of shielding tube beyond the extent of the shielded object is at least 1.5 times the inner diameter of the shielding tube.
[0057] In other embodiments of this invention, suitable materials of different shapes and sizes can be used, as long as the aim of attenuating the intensity of reflected field entering the at least one electrically conductive element can be achieved.
[0058] Many ferrites are made of material with non-zero conductivity. Like the electro-quasi-static shield incorporated in the sensor heads of many detectors, this conductivity is not great enough, nor the intended size of the magnetic shield big enough, for the shield to sustain eddy currents with TC long enough to be detected.
[0059] Generally speaking, the response of ferrite to changes in applied magnetic field is non-linear. As the intensity of the applied field increases, the relative magnetic permeability of the ferrite decreases. The rate of this decrease increases as the intensity of the applied field increases. In extreme cases, increasing the intensity of the applied field can reduce the relative permeability magnetic of the ferrite to near 1. As this relative magnetic permeability is reduced so does the effect of shielding the conductive elements of a sensing head from the reflected field.
[0060] In the case of shielding a solder joint connecting wires carrying electrical current, care must be taken to ensure that the current in the wires does not produce, at any time, a magnetic field that would magnetise the shield to the extent that its degree of magnetisation under the influence of applied fields becomes significantly non-linear. This would reduce the shielding effect of the material, by reducing its relative magnetic permeability. Generally, if a wire carries current through the shield, then another wire should carry the return current through the shield, in the opposing direction to the original current. In this manner the net magnetic field, from the conducting wires, within the shield is substantially zero.
[0061] All that remains to consider is the possibility that the shield is magnetically saturated by the applied Tx field. Whether the shield can be saturated depends upon the material of which the shield is made, the geometry of the Tx winding and the shield, and the intensity of the Tx field at the shield. Saturation can produce a significant reduction of the relative magnetic permeability of the shield while the field is applied. This effect is to be minimised when designing the shield, such as designing the shape, size, dimension, and orientation of the shield with respect to a metal detector.
[0062] The μ r of the material can be anything greater than 1, depending upon the degree of shielding required; as the μ r is increased, the likelihood of saturation increases. In the case of a ferrite tube with its longitudinal axis lying horizontal with respect to the plane of the Tx winding, there will be two components of B-field orientated in opposite directions through the material of the tube, substantially
[0000] B=μH
[0000] cancelling each other. The nett field in the ferrite, in this case, is much less than the equation suggests.
[0063] A detailed description of one or more preferred embodiments of the invention is provided above along with accompanying figures that illustrate by way of example the principles of the invention. While the invention is described in connection with such embodiments, it should be understood that the invention is not limited to any embodiment. On the contrary, the scope of the invention is limited only by the appended claims and the invention encompasses numerous alternatives, modifications, and equivalents. For the purpose of example, numerous specific details are set forth in the description above in order to provide a thorough understanding of the present invention. The present invention may be practiced according to the claims without some or all of these specific details. For the purpose of clarity, technical material that is known in the technical fields related to the invention has not been described in detail so that the present invention is not unnecessarily obscured.
[0064] Throughout this specification and the claims that follow unless the context requires otherwise, the words ‘comprise’ and ‘include’ and variations such as ‘comprising’ and ‘including’ will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.
[0065] The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that such prior art forms part of the common general knowledge of the technical field. | A metal detector includes means for reducing the induction of eddy currents in conductive elements of a sensor head. The aim of this invention is to remove the effect of small pieces of conductive material, located within or close to the sensor head, being seen as sought targets as the sensor head is moved over magnetic matrix. The means is to surround the conductive material with material with high magnetic permeability and low losses in a time-varying magnetic field, say low-loss ferrite. This will prevent the reflected field from illuminating the conductive material so eddy currents are not generated. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the hydraulic fracturing of subterranean formations. In one aspect, the invention relates to a method for degrading polymer residue in a hydraulically induced fracture in subterranean formations.
2. Description of the Prior Art
Hydraulic fracturing has been widely used as a means for improving the rates at which fluids can be injected into or withdrawn from subterranean formations surrounding oil wells and similar boreholes. The methods employed normally involve the injection of a viscous fracturing fluid having a low fluid loss value into the well at a rate sufficient to generate a fracture in the exposed formation, the introduction of fluid containing suspended propping agent particles into the resultant fracture, and the subsequent shutting in of the well until the formation is closed on the injected particles. This results in the formation of a vertical, high-conductivity channels through which fluids can thereafter be injected or produced. The conductivity obtained is a function of the fracture dimensions and the permeability of the bed of propping agent particles within the fracture.
In order to generate the fracture of sufficient length, height, and width and to carry the propping agent particles into the fracture, it is necessary for the fluid to have relatively high viscosity. This viscosity in aqueous liquids is provided by the addition of polymers. Following the treatment of the well, it is desirable to return the aqueous liquid to its low viscosity state, thereby permitting the fracturing fluid and polymer to be removed from the formation and the propped fracture. The highly viscous liquid if left in the fracture would impede the production of formation fluids through the propped fracture. Moreover, the residue of the polymer on the fracture face and in the pores of the propped fracture would significantly reduce fluid permeability therethrough.
To avoid these undersirable after effects of the polymer and polymer residue, it is now common practice to employ in the fracturing fluid chemicals ("breakers") which degrade the polymers U.S. Pat. No. 4,741,401 discloses a number of oxidizing agents contained in capsules for breaking the fracture fluid. U.S. Pat. No. 3,938,594 discloses the use of sodium hypochlorite solution, acid, micellar solutions, and surfactants for degrading the fracturing fluid polymers.
As described in detail in SPE Paper 18862, published Mar. 13-14, 1989, some breakers in fracturing fluids for shallow low temperature (100° F.) treatments are satisfactory for certain polymer gels. This paper further confirms that certain conventional breakers are not effective in fluids gelled with polymers crosslinked with organometallic compounds. For deep, high temperature (175° F. and above) wells, polymers crosslinked with organometallic compounds are generally employed as aqueous viscosifiers. The organometallic crosslinkers were developed for high temperature service exhibiting excellent stability up to about 350° F. Other crosslinkers, such as borate compounds, have an upper temperature limit of about 140° F.
As described in the above SPE Paper, the conventional breakers are not particularly effective with organometallic crosslinked polymers. Moreover, in deep high temperature wells, particularly wells at temperatures in excess of 200° F., breakers cannot generally be used because they tend to degrade the polymer prior to completion of fracture generation phase of the operation.
In these type of wells, clean up of the propped fracture and fracture walls relies on flowing formation fluids therethrough, and may require several months. Acid solutions or other materials sometimes are injected into the propped fracture to assist in polymer degradation. However, these treatments carried out at matrix rates generally results in expending the acid or other compound in the near well bore region (within 10 feet) thereby preventing deep penetration of the active chemical into the fracture.
As demonstrated by the above publications, there is a need for an effective, low cost means for degrading or dissolving polymers in gelled fracturing fluids for deep, high temperature treatments.
As described in detail herein, the present invention involves the use of chlorine dioxide in degrading crosslinked polymers used in high temperature fracturing fluids thereby assisting or effecting cleanup of the fracture. Chlorine dioxide has been proposed for use in a number of oxidizing applications including producing and injection well treatments. For example, Canadian Pat. No. 1,207,269 discloses the use of chlorine dioxide in the separation of oil and water in oil field producing operations. The chlorine dioxide serves as a multifunctional chemical including prevention of sludge and scale, and a biocide for certain compounds in the produced fluid. U.K. Patent Application No. 2170220A also discloses the use of chlorine dioxide in the treatment of wells. In this Application, the chlorine dioxide is added to the produced fluids and serves as a scavenger for hydrogen sulfide. Finally, PCT Application International Publication No. W085/01722 discloses the use of chlorine dioxide in the treatment of produced fluids to eliminate sulfide at oil water interphases. These prior uses of chlorine dioxide have been restricted to produced fluids.
Chlorine dioxide has also been used to degrade polymer in polymer flooding injection wells. In this application, the chlorine dioxide treatment is on noncrosslinked polymers, and effective only in the well perforations and near wellbore region (within 10 feet). Polymer solutions used in polymer flooding are generally dilute solutions containing much less polymer than in fracturing fluids.
SUMMARY OF THE INVENTION
The present invention is directed at cleaning fractures generated by gelled fracturing fluids (e.g. those containing cross-linked polymers) in deep, high temperature wells (175° F. to 450° [350°] F. and above). The fracturing fluids used in these wells are typically guar, guar derivatives, acrylamide, acrylamide derivatives, cellulose and cellulose derivatives, crosslinked with an organometallic compounds or other compounds providing covalent bonding.
The method according to the present invention comprises five essential steps: (1) injecting a viscous, gelled fracturing fluid through a wellbore and into a subterranean formation at a rate sufficient to form a vertical fracture in the formation, the fracturing fluid generally containing propping agent particles, and other additives for maintaining the fracture in a propped condition; (2) backflowing the [gelled] fracturing fluid through the wellbore to remove substantial amounts of the gelled fluid from the propped fracture; (3) injecting an aqueous solution of chlorine dioxide into the fracture to penetrate deeply in the propped fracture to degrade the polymer and dissolve substantial amounts of the residue polymer in the propped fracture and on the fracture walls; (4) permitting the aqueous chlorine dioxide to react with the polymer; and (5) producing fluid from the formation through the propped fracture into the wellbore.
The amount of the chlorine dioxide solution injected into the fracture should be sufficient to penetrate at least 20%, and preferably at least 50%, and most preferably at least 75%, of the fracture length. The chlorine dioxide concentration in the aqueous medium may range from 50 to 4200 ppm, preferably between about 100 to 2000 ppm, and most preferably, between 100 and 1000 ppm. These minor but effective amounts of chlorine dioxide makes this treatment economically attractive compared to alternative breakers and oxidants; particularly at the severe treating conditions encountered in deep, high temperature wells.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a magnified (50X) photograph of a simulated propped fracture illustrating polymer residue (guar) in the pores thereof and fracture wall.
FIG. 2 is a magnified (25X) photograph of a simulated propped fracture showing the condition of the propped fracture following treatment with chlorine dioxide.
FIG. 3 is a magnified (25X) photograph similar to FIG. 1 illustrating polymer residue (HPG) in the pores thereof and on the fracture walls.
FIG. 4 is a magnified (30X) photograph similar to FIG. 3, illustrating the condition of the propped fracture following treatment with chlorine dioxide.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the fracturing of subterranean formations, a viscous fracturing fluid is pumped through the wellbore at a rate and pressure to cause a vertical fracture to form in the formation. The fracture generally extends out from 300 to 400 feet from the wellbore for oil wells and from 800 to 1200 feet for gas wells. In order to generate fracture of this magnitude, the fluid must be viscosified with a gel, (e.g. water-soluble polymers). The polymers commonly used in deep, high temperature wells are cross-linked polymers such as guar, hydroxypropyl guar and carboxy-methylhydroxypropyl guar and are present in the aqueous fracturing fluid at concentrations from about 10 to 80 pounds per 1000 gallons. Other polymers for high temperature service (i.e. above 175° F.) include carboxymethyl [and] hydroxyethyl cellulose, acrylamide copolymers, crosslinked with organotitanate, organozirconate, aluminum, and antimony compounds.
Tests have shown that if these gelled fluids and their residue are not removed following the fracture treatment, the conductivity of the propped fracture can be reduced by as much as 90%. The damage is due to two types of plugging: (1) the residue on the fracture walls caused by the filter cake buildup thereon, and (2) by the viscous fluid and residue left in the pores of the propped fracture.
Tests have also shown that the damage to the fracture is more severe in high temperature wells because only certain cross-linked fluids (e.g. those crosslinked with organometallic cross-linkers) can be used. These crosslinked, gels generally present in the fracturing fluid at concentrations ranging from 0.25 to 1.00 wt%, are difficult to break. Moreover, as mentioned above, for deep wells, breakers frequently cannot be used.
FIGS. 1 and 3 show the residue left on the propped particles and fracture walls of a simulated propped fracture based on laboratory tests. Prior to treatment in accordance with the present invention, these propped fractures had retained permeabilities of only 23.7% and 25.3%, respectively. (Retained permeability is damaged permeability divided by undamaged permeability times 100.)
The method of the present invention employs dilute aqueous solutions of chlorine dioxide to degrade the polymer and dissolve polymer residue in the fracture and on the fracture walls. The chlorine dioxide solution is injected into the propped fracture following the fracturing treatment and flow back of the well. The injection is at matrix rates and is in such amounts to provide deep penetration into the propped fracture. One of the advantages of the chlorine dioxide is that it is not reactive with most formation materials and at the dilute concentration is not unduly corrosive.
The amount and concentration of the chlorine dioxide solution will depend upon several factors, including the length of the fracture generated, the degree of difficulty in degrading the polymer, temperature, and fracture geometry. Normally however, the concentration of the chlorine dioxide in the aqueous medium will be between 50 and 4,200 ppm, preferably 100 to 2000 ppm, and most preferably between 100 and 1000 ppm. The volume of this solution will be injected to invade at least 20% of the propped fracture. Thus, for most oil wells, the solution penetration will be at least 60 feet and for most gas wells at least 100 feet. The upper limit of the volume will be dictated by economics but ten pore volumes of the propped fracture will be sufficient for most applications. Preferably from .2 to 10 pore volumes will be injected. The fracture pore volume is defined as the calculated pore volume of the propped fracture following bleed off.
The chlorine dioxide may be used as a aqueous solution generated at the site of use. As is known, chlorine dioxide is a unstable highly reactive gas which is soluble in and decomposes in water. Because of its instability, it is common for chlorine dioxide to be generated at the point of use and used immediately. Several methods of onsite preparation of chlorine dioxide is described as for example in U.S. Pat. Nos. 4,077,879; 4,247,531; and 4,590,057; all of which are incorporated herein by reference.
Alternatively, the chlorine dioxide may be added in the form of stabilized chlorine dioxide solution. Stabilized chlorine dioxide is a compound which dissociates and tends to maintain the available chlorine dioxide in the aqueous solution at a fixed level. DIKLOR marketed by Exxon Chemical Company is a stabilized chlorine dioxide.
Operation
Prior to commencing pumping operations, aqueous chlorine dioxide is generated at the well site. DIKLOR S generated by a system provided by Exxon Chemical Company is one source of chlorine dioxide. This system generates aqueous chlorine dioxide at concentration levels of 1 to about 4,200 ppm. As a general rule, and subject to economics, the amount of chlorine dioxide needed will depend on the amount of polymer used in the fracturing fluid.
The weight ratio of chlorine dioxide to polymer will range from about 1:5 to 1:100 with 1:10 to 1:50 being preferred.
For many treatments, 3,000 to 20,000 gallons of the dilute (50 to 4200 ppm) chlorine dioxide will by prepared in a rig tank. Alternatively, where generated chlorine dioxide is used (e.g. DIKLOR S), the aqueous chlorine dioxide may be generated and pumped down the well alone or with other fluids (including water) at the generation rate.
In a preferred embodiment of the invention, the fracturing operation will be carried out in the normal manner which may involve the following injection sequence: a preflush (a pad of gelled aqueous fracturing fluid without proppant), followed by the fracturing fluid with proppant. The aqueous fracturing fluid will normally have a neutral pH (6-8) although acid or base pH may also be employed (pH 3 to 10). The fracture is generated and propagated as pumping continues to permit the placement of the propping agent. The fracture is then permitted to close on the propped fracture with the fluid bleeding off into the formation. The well is normally shut in for a period ranging from 2 to 24 hours. The well then is backflowed to remove a portion of the gelled fracture fluid from the propped fracture. Backflowing causes formation fluids to displace a portion of the fracturing fluid in the propped fracture. The amount of backflowing will vary but from 0.2 to 0.9 pore volume of the propped fracture volume are typical to remove at least 10% of the polymers from the propped fracture. Following the backflowing step, the aqueous chlorine dioxide solution is injected into the formation at matrix rates to penetrate deeply into the fracture. The active chlorine dioxide should penetrate at least 60 feet and preferably at 100 feet into the propped fracture. The well is then shut in for a period ranging from 1 to 24 hours to permit the chlorine dioxide to react and degrade and/or dissolve the polymer. It should be noted that the chlorine dioxide reacts with the polymer on the fracture face as well as the polymer residue in the pores of the propped fracture.
The fracturing fluid used in the treatment of wells may also include other additives such as fluid loss additives, corrosion inhibitors, buffers, clay stabilizers, non-emulsifiers, surfactants, etc.
The following laboratory experiments demonstrate the severity of fracture plugging caused by gelled fracturing fluids and the effectiveness of chlorine dioxide solution in fracture cleanup.
EXPERIMENTS
EXPERIMENTS______________________________________Equipment:Test Cell Two core slabs (Ohio Sandstone) samples were retained in an apparatus and positioned to have confronting faces to simulate a horizontal fracture. Pumping, flowline, and temperature control facilities were provided to control injection into the space between the cores, leak off from the cores, and temperature of the core and fluids.Materials:2 wt % KCl water solution (core saturation)Frac Fluid:Pad 2 wt % KCl water solutionBase Gel Sample A: hydroxypropyl guar (HPG).sup.2 Sample B: guar.sup.1 Sample C: acrylamide baseCrosslinked Gel Sample A: HPG with titanate.sup.3. Sample B: Guar with titanate.sup.3. Sample C: Acrylamide base polymer with titanate.sup.3.Proppant 20/40 mesh sintered alumina proppant.sup.4.Chlorine 0.42% aqueous solution.sup.5.DioxideTest Procedure:The fluid injected (at 2 ml/min.) into the cell ineach test was in the following sequence. Flow Time2% KCl water solution 10 min.Base gel 10 min.Crosslinked gel 90 min.Crosslinked gel with proppant packed to desired concentration______________________________________ .sup.1 marketed by Aqualon Co. or HiTek Polymers, Inc. .sup.2 marketed by Aqualon Co. or HiTek Polymers, Inc. .sup.3 marketed by DuPont as Tyzor GBA .sup.4 marketed by Norton Abrasives as Interprop Plus .sup.5 marketed by Exxon Chemical Company as DIKLOR S
The fracturing fluid was mixed and sheared to simulate pumping through the well tubing. The fluid was sheared and heated to 150° F. and pumped at a shear rate of 40-50/sec into the cell maintained at 120° F. The cell temperatures was set at 120° F. to model cooldown. The leakoff rate from each core was monitored vs time. A back pressure of 1000 psi was maintained on the cell. Residence time in the cell was approximately 5 minutes.
The proppant amount was selected in each test to provide 2 lb/sq ft in the 1/3 inch slot separating the core faces in the cell. Once the proppant was placed, a closure stress of 1000 psi was applied. The cell was shut-in at the control temperature (250° F.) and allowed to set for 10 hours.
The cell was then opened and backflow was simulated by pumping 2% KCl at 2ml/min for 50 min., while closure stress was increased to 8000 psi.
Chlorine dioxide (DIKLOR S) was then flushed alternately through (a) the packed space and (b) through a portion of the packed space and vertically through the core slabs (by means of bleed off valves in the top and bottom of the apparatus holding the slabs core). The cell was shut in and production simulated by flowing 2% KCl through the cell at 2 ml/min for 50 hrs. Conductivity and permeability of the packed spaced (e.g. packed fracture) were recorded hourly and represented in the Tables as a 10 hour average.
EXPERIMENT No. 1 (SAMPLE A)
The 2% KCl and base gel and crosslinked gel were injected into the cell as described above. The gel concentration was 40 lb/1000 gallon. The initial chlorine dioxide treatment was with 500 ppm (DIKLOR S) which was flowed alternately through the cell at 2 ml/min at 10 min. intervals as follows
10 min. through the pack
10 min. through one core slab
10 min. through the other core slab
10 min. through the pack
Closed in for 4 hours
The second chlorine dioxide treatment was with 1000 ppm DIKLOR S which was flowed at 1 ml/min through the pack and cores in the following sequence
25 min. through pack
40 min. through core slabs
60 min. through pack
The cell shut in for 2 hours.
Table I presents the recorded data.
TABLE I__________________________________________________________________________ HOURS CLOSURE CONDUC- AFTER STRESS TIVITY WIDTH PERM. CLOSURE (psi) (md.ft.) (in.) (Darcies)__________________________________________________________________________Before Treatment 0 8000 680 0.186 43.9After Initial 10 8000 1467 0.184 95.7TreatmentAfter SecondTreatment 20 8000 1135 0.180 75.7 50 8000 1161 0.180 77.4__________________________________________________________________________
The percent retained permeability was 43% (2% KCl solution). This represents an 81% improvement. The equilibrium leakoff rate was 0.0114 ml/min/sqcm. and the Cw was 0.00281 ft/sq. root min. (Cw is the combined fluid loss coefficient of the fracturing fluid.)
FIG. 3 illustrates considerable polymer on the fracture face as a filter cake prior to treatment. FIG. 4 taken after treatment illustrates a clean fracture face.
EXPERIMENT NO. 2 (SAMPLE B)
Experiment No. 2 used Sample B and was similar to Experiment No. 1 except only one chlorine dioxide treatment (1000 ppm DIKLOR-S) was used. DIKLOR-S was flushed through the cell at 1 ml/min in the following sequence:
25 min. through pack
40 min. through core slabs
60 min. through pack
The cell was then shut in for 2 hours. The data for the simulated fracture are presented in Table II.
TABLE II__________________________________________________________________________ HOURS CLOSURE CONDUC- AFTER STRESS TIVITY WIDTH PERM. CLOSURE (psi) (md.ft.) (in) (Darcies)__________________________________________________________________________Before Treatment 0 8000 707 0.184 46.1 10 8000 1041 0.182 68.6After Treatment 18 8000 877 0.181 58.5 30 8000 1135 0.180 75.7 50 8000 1299 0.180 86.6__________________________________________________________________________
Retained permeability was 48% (2% KCl solution), or 98% improvement over the damaged untreated propped fracture. Equilibrium Leakoff rate was 0.0119 ml.min/sqcm. Cw was 0.00285 ft/sq. root min.
FIG. 1 illustrates the presence of guar in the pores and on the fracture wall prior to treatment. However, as illustrated in FIG. 2, the chlorine dioxide treatment removed substantial amounts of the polymer residence from the pores and the walls.
EXPERIMENT NO. 3 (SAMPLE C)
Experiment No. 3 was carried out with Sample C. This test was similar to Experiments 1 and 2 except the chlorine dioxide flushing was as follows:
250 ppm DIKLOR-S flowed at 1 ml/min through the pack for 80 min., followed by 1 hour shut-in, and finally 250 ppm DIKLOR-S was flowed through the core slabs for 80 min. at 0.5 ml/min and then through the pack for 20 min. at 1 ml/min.
The cell was then shut-in for 1 hour.
Table III presents the data for the simulated fracture:
TABLE III__________________________________________________________________________ HOURS CLOSURE CONDUC- AFTER STRESS TIVITY WIDTH PERM. CLOSURE (psi) (md.ft.) (in) (Darcies)__________________________________________________________________________Before Treatment 0 8000 445 0.186 28.7After Treatment 10 8000 765 0.184 49.9 250 8000 1702 0.180 113.5 30 8000 2273 0.180 151.5 50 8000 2335 0.180 155.7__________________________________________________________________________
Retained permeability was 86% (2% KCl), more than five times higher than the untreated damaged propped fracture. Cw - 0.00313 ft/sq. root min.
The improved results demonstrated by the above experiments are believed due to the following three factors: (a) the viscous crosslinked polymer fluid is broken, (b) high conductivity holes are formed in the propped fracture (best seen in FIG. 2), and (c) elimination of residue on the fracture wall (compare FIGS. 3 and 4).
The chlorine dioxide in addition to reacting with the polymer gelling agent will also react with resinous fluid loss additives.
These tiny resinous particles reduce fluid loss of the fracturing fluid by forming, or assist in forming, a filter cake on the fracture wall. Typically, resinous fluid loss additives are made of C 5 olefinic compounds. One such commercial material is marketed by Hercules Chemical Company as Piccovar AB-180.
It is desirable to remove the filter cake containing the polymer and resinous fluid loss additives following treatment to increase permeability of formation fluids into and through the propped fracture.
Laboratory tests on mixtures of resin and polymers (guar and HPG) in 2% KCl at 180.F indicated that the chlorine dioxide reacts with both the resin and the polymer gelling agent. The reaction is faster with the gelling agent polymer than with the resin.
The resinous fluid loss additive in the filter cake thus limits chlorine dioxide leak off into the formation permitting deep penetration of active chlorine dioxide into the propped fracture. However, with time, the resin is also degraded by the chlorine dioxide. | A method of fracturing a subterranean formation involving the use of crosslinked gels to form a fracture and deposit particulate proppant therein followed by the introduction of dilute aqueous solutions of chlorine dioxide in the propped fracture to degrade the gel. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application contains subject matter that may be related to the subject matter in the following U.S. applications filed on Apr. 22, 2005, and assigned to the assignee of the present application: “Method and Apparatus for Managing and Accounting for Bandwidth Utilization Within A Computing System” with U.S. application Ser. No. 11/112,367 (Attorney Docket No. 03226/643001; SUN050681); “Method and Apparatus for Consolidating Available Computing Resources on Different Computing Devices” with U.S. application Ser. No. 11/112,368 (Attorney Docket No. 03226/644001; SUN050682); “Assigning Higher Priority to Transactions Based on Subscription Level” with U.S. application Ser. No. 11/112,947 (Attorney Docket No. 03226/645001; SUN050589); “Method and Apparatus for Dynamically Isolating Affected Services Under Denial of Service Attack” with U.S. application Ser. No. 11/112,158 (Attorney Docket No. 03226/646001; SUN050587); “Method and Apparatus for Improving User Experience for Legitimate Traffic of a Service Impacted by Denial of Service Attack” with U.S. application Ser. No. 11/112,629 (Attorney Docket No. 03226/647001; SUN050590); “Method and Apparatus for Limiting Denial of Service Attack by Limiting Traffic for Hosts” with U.S. application Ser. No. 11/112,328 (Attorney Docket No. 03226/648001; SUN050591); “Hardware-Based Network Interface Per-Ring Resource Accounting” with U.S. application Ser. No. 11/112,222 (Attorney Docket No. 03226/649001; SUN050593); “Dynamic Hardware Classification Engine Updating for a Network Interface” with U.S. application Ser. No. 11/112,934 (Attorney Docket No. 03226/650001; SUN050592); “Network Interface Card Resource Mapping to Virtual Network Interface Cards” with U.S. application Ser. No. 11/112,063 (Attorney Docket No. 03226/651001; SUN050588); “Network Interface Decryption and Classification Technique” with U.S. application Ser. No. 11/112,436 (Attorney Docket No. 03226/652001; SUN050596); “Method and Apparatus for Enforcing Resource Utilization of a Container” with U.S. application Ser. No. 11/112,910 (Attorney Docket No. 03226/653001; SUN050595); “Method and Apparatus for Enforcing Packet Destination Specific Priority Using Threads” with U.S. application Ser. No. 11/112,584 (Attorney Docket No. 03226/654001; SUN050597); “Method and Apparatus for Processing Network Traffic Associated with Specific Protocols” with U.S. application Ser. No. 11/112,228 (Attorney Docket No. 03226/655001; SUN050598).
[0002] The present application contains subject matter that may be related to the subject matter in the following U.S. applications filed on Oct. 21, 2005, and assigned to the assignee of the present application: “Method and Apparatus for Defending Against Denial of Service Attacks” with U.S. application Ser. No. 11/255,366 (Attorney Docket No. 03226/688001; SUN050966); “Router Based Defense Against Denial of Service Attacks Using Dynamic Feedback from Attacked Host” with U.S. application Ser. No. 11/256,254 (Attorney Docket No. 03226/689001; SUN050969); and “Method and Apparatus for Monitoring Packets at High Data Rates” with U.S. application Ser. No. 11/226,790 (Attorney Docket No. 03226/690001; SUN050972).
[0003] The present application contains subject matter that may be related to the subject matter in the following U.S. applications filed on Jun. 30, 2006, and assigned to the assignee of the present application: “Method and System for Controlling Virtual Machine Bandwidth” with U.S. application Ser. No. TBD (Attorney Docket No. 03226/871001; SUN061021); “Virtual Switch” with U.S. application Ser. No. TBD (Attorney Docket No. 03226/873001; SUN061023); “System and Method for Virtual Network Interface Cards Based on Internet Protocol Addresses” with U.S. application Ser. No. TBD (Attorney Docket No. 03226/874001; SUN061024); “Virtual Network Interface Card Loopback Fastpath” with U.S. application Ser. No. TBD (Attorney Docket No. 03226/876001; SUN061027); “Bridging Network Components” with U.S. application Ser. No. TBD (Attorney Docket No. 03226/877001; SUN061028); “Reflecting the Bandwidth Assigned to a Virtual Network Interface Card Through Its Link Speed” with U.S. application Ser. No. TBD (Attorney Docket No. 03226/878001; SUN061029); “Method and Apparatus for Containing a Denial of Service Attack Using Hardware Resources on a Virtual Network Interface Card” with U.S. application Ser. No. TBD (Attorney Docket No. 03226/879001; SUN061033); “Virtual Network Interface Cards with VLAN Functionality” with U.S. application Ser. No. TBD (Attorney Docket No. 03226/882001; SUN061037); “Method and Apparatus for Dynamic Assignment of Network Interface Card Resources” with U.S. application Ser. No. TBD (Attorney Docket No. 03226/883001; SUN061038); “Generalized Serialization Queue Framework for Protocol Processing” with U.S. application Ser. No. TBD (Attorney Docket No. 03226/884001; SUN061039); “Serialization Queue Framework for Transmitting Packets” with U.S. application Ser. No. TBD (Attorney Docket No. 03226/885001; SUN061040).
BACKGROUND
[0004] Network traffic is transmitted from a network, such as the Internet, from a sending system (e.g., a computer system) to a receiving system (e.g., a computer system) via a network interface card (NIC). The NIC is a piece of hardware found in a typical computer system that includes functionality to send and receive network traffic. Typically, network traffic is transmitted in the form of packets, where each packet includes a header and a payload. The header contains information regarding the source address, destination address, size, transport protocol used to transmit the packet, and various other identification information associated with the packet. The payload contains the actual data to be transmitted from the network to the receiving system.
[0005] Each of the packets sent between the sending system and receiving system is typically associated with a connection. The connection ensures that packets from a given process on the sending system reach the appropriate process on the receiving system. Packets received by the receiving system (via a NIC associated with the receiving system) are analyzed by a classifier to determine the connection associated with the packet.
[0006] Typically, the classifier includes a connection data structure that includes information about active connections on the receiving system. The connection data structure may include the following information about each active connection: (i) the queue associated with the connection; and (ii) information necessary to process the packets on the queue associated with the connection. Depending on the implementation, the connection data structure may include additional information about each active connection. Such queues are typically implemented as first-in first-out (FIFO) queues and are bound to a specific central processing unit (CPU) on the receiving computer system. Thus, all packets for a given connection are placed in the same queue and are processed by the same CPU. In addition, each queue is typically configured to support multiple connections.
[0007] Once the classifier determines the connection associated with the packets, the packets are sent to a temporary data structure (e.g., a receive ring on the NIC) and an interrupt is issued to the CPU associated with the queue. In response to the interrupt, a thread associated with the CPU (to which the serialization queue is bound) retrieves the packets from the temporary data structure and places them in the appropriate queue. Once packets are placed in the queue, those packets are processed in due course. In some implementations, the queues are implemented such that only one thread is allowed to access a given queue at any given time.
SUMMARY
[0008] In general, in one aspect, the invention relates to a method for virtualizing a network interface card, comprising creating a first plurality of virtual NICs, assigning each of a plurality of receive rings on the network interface card (NIC) to one of the first plurality of virtual NICs, and if the number of virtual NICs is greater than the number of receive rings on the NIC, creating a first software ring corresponding to one of the plurality of receive rings on the NIC, creating a first plurality of software receive rings associated with the first software ring, creating a second plurality of virtual NICs, and assigning each of the first plurality of software receive rings to one of the second plurality of virtual NICs, wherein the plurality of receive rings is less than a sum of the first plurality of virtual NICs and the second plurality of virtual NICs.
[0009] In general, in one aspect, the invention relates to a system, comprising a network interface card (NIC) comprising a plurality of receive rings and a host operatively connected to the NIC comprising a first plurality of virtual NICs, a first software ring, a first plurality of software receive rings associated with the first software ring, and a second plurality of virtual NICs, wherein each of the plurality of receive rings is associated with one selected from a group consisting of one of the first plurality of virtual NICs and the first software ring, and wherein at least one of the first plurality of software receive rings is associated with one of the second plurality of virtual NICs.
[0010] In general, in one aspect, the invention relates to a computer usable medium having computer readable program code embodied therein for causing a computer system to execute a method for virtualizing a network interface card (NIC), the method comprising creating a first plurality of virtual NICs, assigning each of a plurality of receive rings on the network interface card (NIC) to one of the first plurality of virtual NICs, and if the number of virtual NICs is greater than the number of receive rings on the NIC, creating a first software ring corresponding to one of the plurality of receive rings on the NIC, creating a first plurality of software receive rings associated with the first software ring, creating a second plurality of virtual NICs, and assigning each of the first plurality of software receive rings to one of the second plurality of virtual NICs, wherein the plurality of receive rings is less than a sum of the first plurality of virtual NICs and the second plurality of virtual NICs.
[0011] Other aspects of the invention will be apparent from the following description and the appended claims.
BRIEF DESCRIPTION OF DRAWINGS
[0012] FIG. 1 shows a schematic diagram in accordance with one or more embodiments of the invention.
[0013] FIG. 2 shows a virtual network stack in accordance with one or more embodiments of the invention.
[0014] FIGS. 3-4 show flow charts in accordance with one or more embodiments of the invention.
[0015] FIG. 5 shows a computer system in accordance with one or more embodiments of the invention.
DETAILED DESCRIPTION
[0016] Specific embodiments of the invention will now be described in detail with reference to the accompanying figures. Like elements in the various figures are denoted by like reference numerals for consistency.
[0017] In the following detailed description of embodiments of the invention, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description.
[0018] In general, embodiments of the invention provide a method and apparatus to virtualize network interface cards (NICs). In one or more embodiments of the invention, each virtual NIC is associated with a serialization stack containing a virtual serialization queue and a virtual protocol stack. In one or more embodiments of the invention, virtual NICs are associated with packet destinations, which may be containers, virtual machines, or services. Further, packets may be transmitted either through polling mode or interrupt mode.
[0019] Further, embodiments of the invention provide a method and apparatus to virtualize NICs when the number of virtual NICs exceeds the number of receive rings on the physical NIC. In one or more embodiments of the invention, each receive ring on the physical NIC is associated with a virtual NIC. When there are many virtual NICs and not enough receive rings in hardware, one or more software rings are created on top of a receive ring to further route packets. In one or more embodiments of the invention, software receive rings are created within the software ring, and virtual NICs are created on top of the software receive rings.
[0020] FIG. 1 shows a system in accordance with one or more embodiments of the invention. As shown in FIG. 1 , the system includes a network interface card ( 100 ), multiple software rings (e.g., software ring 1 ( 155 ), software ring 2 ( 200 )), multiple virtual NICs (e.g., virtual NIC 1 ( 125 ), virtual NIC 2 ( 130 ), virtual NIC 3 ( 225 ), virtual NIC 4 ( 180 ), virtual NIC 5 ( 220 )), multiple receive rings (e.g., receive ring 1 ( 105 ), receive ring 2 ( 110 ), receive ring n ( 115 )), and multiple software receive rings (e.g., software receive ring 1 ( 165 ), software receive ring 2 ( 170 ), software receive ring 3 ( 210 ), software receive ring 4 ( 215 )). Each of these components is described below.
[0021] The network interface card ( 100 ), or NIC, refers to a piece of hardware designed to allow computers to communicate over a physical network (not shown). The NIC ( 100 ) includes a network interface (NI) (i.e., the hardware on the NIC used to interface with the network). For example, the NI may correspond to an RJ-45 connector, a wireless antenna, etc. The packets received by the NI are then sent to other components on the NIC ( 100 ) for processing. The NIC ( 100 ) may be connected to a host ( 103 ) via an expansion card. Alternatively, the NIC ( 100 ) may reside on the motherboard of the host ( 103 ). The NIC ( 100 ) is associated with a Media Access Control (MAC) address and may transfer data in interrupt mode, in which the NIC ( 100 ) alerts the host ( 103 ) of an available data transfer, or in polling mode, in which the host ( 103 ) requests data from the NIC ( 100 ). Those skilled in the art will appreciate that other modes of data transfer, such as programmed Input/Output (I/O) or Direct Memory Access (DMA), may be used for data transfer between the host ( 103 ) and the NIC ( 100 ).
[0022] The NIC ( 100 ) also includes multiple receive rings (e.g., receive ring 1 ( 105 ), receive ring 2 ( 110 ), receive ring n ( 115 )) and a classifier ( 120 ). In one or more embodiments of the invention, the receive rings (e.g., receive ring 1 ( 105 ), receive ring 2 ( 110 ), receive ring n ( 115 )) correspond to portions of memory within the NIC ( 100 ) used to temporarily store the received packets. Further, in one embodiment of the invention, a ring element of the receive rings (e.g., receive ring 1 ( 105 ), receive ring 2 ( 110 ), receive ring n ( 115 )) may point to host memory. In one or more embodiments of the invention, the receive rings (e.g., receive ring 1 ( 105 ), receive ring 2 ( 110 ), receive ring n ( 115 )) are implemented as ring buffers in the NIC ( 100 ). In one or more embodiments of the invention, a device driver (not shown) provides an interface between the NIC ( 100 ) and the host ( 103 ) and exposes the receive rings (e.g., receive ring 1 ( 105 ), receive ring 2 ( 110 ), receive ring n ( 115 )) to the host. In one embodiment of the invention, the classifier ( 120 ) is configured to analyze the incoming network traffic, typically in the form of packets, received from the network (not shown).
[0023] In one embodiment of the invention, analyzing individual packets includes determining to which of the receive rings (e.g., receive ring 1 ( 105 ), receive ring 2 ( 110 ), receive ring n ( 115 )) each packet is sent. In one embodiment of the invention, analyzing the packets by the classifier ( 120 ) includes analyzing one or more fields in each of the packets to determine to which of the receive rings (e.g., receive ring 1 ( 105 ), receive ring 2 ( 110 ), receive ring n ( 115 )) the packets are sent. As an alternative, the classifier ( 120 ) may use the contents of one or more fields in each packet as an index into a data structure that includes information necessary to determine to which receive ring (e.g., receive ring 1 ( 105 ), receive ring 2 ( 110 ), receive ring n ( 115 )) that packet is sent. The classifier ( 120 ) may be implemented entirely in hardware (i.e., the classifier ( 120 ) may be a separate microprocessor embedded on the NIC ( 100 )), or the classifier ( 120 ) may be implemented in software stored in memory (e.g., firmware, etc.) on the NIC and executed by a microprocessor on the NIC ( 100 ).
[0024] In one or more embodiments of the invention, each receive ring (e.g., receive ring 1 ( 105 ), receive ring 2 ( 110 ), receive ring n ( 115 )) is associated with a virtual NIC (e.g., virtual NIC 1 ( 125 ), virtual NIC 2 ( 130 )). The virtual NICs (e.g., virtual NIC 1 ( 125 ), virtual NIC 2 ( 130 )) provide an abstraction layer between the NIC ( 100 ) and the various packet destinations (e.g., packet destination 1 ( 145 ), packet destination 2 ( 150 )) (e.g., containers and/or services) executing on the host ( 103 ). More specifically, each virtual NIC (e.g., virtual NIC 1 ( 125 ), virtual NIC 2 ( 130 )) operates like a NIC ( 100 ). For example, in one embodiment of the invention, each virtual NIC (e.g., virtual NIC 1 ( 125 ), virtual NIC 2 ( 130 )) is associated with one or more Internet Protocol (IP) addresses, associated with one ore more MAC addresses, associated with one or more ports, and configured to handle one or more protocol types. Thus, while the host ( 103 ) may be operatively connected to a single NIC ( 100 ), packet destinations (e.g., packet destination 1 ( 145 ), packet destination 2 ( 150 )) (e.g., containers, virtual machines, and/or services) executing on the host ( 103 ) operate as if the host ( 103 ) is bound to multiple NICs. Those skilled in the art will appreciate that a virtual NIC (e.g., virtual NIC 1 ( 125 ), virtual NIC 2 ( 130 )) may be defined solely by one or more IP addresses or one or more MAC addresses, and that ports and protocols are not required to instantiate a virtual NIC.
[0025] Each of the virtual NICs (e.g., virtual NIC 1 ( 125 ), virtual NIC 2 ( 130 )) is operatively connected to a corresponding serialization stack (e.g., serialization stack 1 ( 135 ), serialization stack 2 ( 140 )). In one embodiment of the invention, each serialization stack (e.g., serialization stack 1 ( 135 ), serialization stack 2 ( 140 )) includes functionality to process packets in accordance with various protocols used to send and receive packets (e.g., Transmission Communication Protocol (TCP), Internet Protocol (IP), User Datagram Protocol (UDP), etc.). Further, each serialization stack (e.g., serialization stack 1 ( 135 ), serialization stack 2 ( 140 )) may also include functionality, as needed, to perform additional processing on the incoming and outgoing packets. This additional processing may include, but is not limited to, cryptographic processing, firewall routing, etc.
[0026] In one embodiment of the invention, each serialization stack (e.g., serialization stack 1 ( 135 ), serialization stack 2 ( 140 )) includes network layer and transport layer functionality. In one embodiment of the invention, network layer functionality corresponds to functionality to manage packet addressing and delivery on a network (e.g., functionality to support IP, Address Resolution Protocol (ARP), Internet Control Message Protocol, etc.). In one embodiment of the invention, transport layer functionality corresponds to functionality to manage the transfer of packets on the network (e.g., functionality to support TCP, UDP, Stream Control Transmission Protocol (SCTP), etc.).
[0027] In one embodiment of the invention, each serialization stack (e.g., serialization stack 1 ( 135 ), serialization stack 2 ( 140 )) includes a virtual serialization queue (not shown). In one embodiment of the invention, each virtual serialization queue corresponds to a data structure having at least two queues, an inbound queue and an outbound queue. Each of the queues within the virtual serialization queues is typically implemented as first-in first-out (FIFO) queues. Further, each virtual serialization queue is configured to send and receive packets from an associated virtual NIC (e.g., virtual NIC 1 ( 125 ), virtual NIC 2 ( 130 )) via an associated serialization stack (e.g., serialization stack 1 ( 135 ), serialization stack 2 ( 140 )). In addition, each virtual serialization queue is configured to send and receive packets from one or more associated packet destinations ( 118 ) (e.g., containers and/or services). The structure of the virtual serialization queue is discussed in greater detail in FIG. 2 .
[0028] In one embodiment of the invention, the virtual NIC (e.g., virtual NIC 1 ( 125 ), virtual NIC 2 ( 130 )) may be bound to a virtual machine (e.g., Xen Domain) instead of a serialization stack (e.g., serialization stack 1 ( 135 ), serialization stack 2 ( 140 )). In such cases, the virtual NIC is bound to an interface (e.g., a Xen interface), where the interface enables the virtual NIC to communicate to with the virtual machine. In one embodiment of the invention, the aforementioned virtual machine includes its own serialization stack and includes its own operating system (OS) instance, which may be different than the OS executing on the host.
[0029] Continuing with FIG. 1 , the system also includes two software rings (e.g., software ring 1 ( 155 ), software ring 2 ( 160 )). In one or more embodiments of the invention, a software ring is created when more virtual NICs (e.g., virtual NIC 1 ( 125 ), virtual NIC 2 ( 130 ), virtual NIC 3 ( 225 )virtual NIC 4 ( 180 ), virtual NIC 5 ( 220 )) are needed than there are receive rings (e.g., receive ring 1 ( 105 ), receive ring 2 ( 110 ), receive ring n ( 115 )) on the physical NIC ( 100 ). In one embodiment of the invention, each of the software receive rings is located in the Media Access Control (MAC) layer of the host ( 103 ). As shown in FIG. 1 , each software ring (e.g., software ring 1 ( 155 ), software ring 2 ( 160 )) is associated with multiple software receive rings (e.g., software receive ring 1 ( 165 ), software receive ring 2 ( 170 ), software receive ring 3 ( 210 ), software receive ring 4 ( 215 )). In one or more embodiments of the invention, the software receive rings are configured to temporarily store received packets in memory, similar to receive rings (e.g., receive ring 1 ( 105 ), receive ring 2 ( 110 ), receive ring n ( 115 )) on the physical NIC ( 100 ).
[0030] Software classifiers (e.g., software classifier 1 ( 160 ), software classifier 2 ( 205 )) associated with each software ring (e.g., software ring 1 ( 155 ), software ring 2 ( 160 )) analyze each received packet to determine to which software receive ring (e.g., software receive ring 1 ( 165 ), software receive ring 2 ( 170 ), software receive ring 3 ( 210 ), software receive ring 4 ( 215 )) to send the packet. Similar to the classifier ( 120 ) on the NIC ( 100 ), the software classifiers (e.g., software classifier 1 ( 160 ), software classifier 2 ( 205 )) may use the contents of one or more fields in the packet to direct the packet to the appropriate software receive ring (e.g., software receive ring 1 ( 165 ), software receive ring 2 ( 170 ), software receive ring 3 ( 210 ), software receive ring 4 ( 215 )). Those skilled in the art will appreciate that an arbitrary number of software receive rings (e.g., software receive ring 1 ( 165 ), software receive ring 2 ( 170 ), software receive ring 3 ( 210 ), software receive ring 4 ( 215 )) may be associated with a software ring (e.g., software ring 1 ( 155 ), software ring 2 ( 160 )).
[0031] In addition, each software receive ring (e.g., software receive ring 1 ( 165 ), software receive ring 2 ( 170 ), software receive ring 3 ( 210 ), software receive ring 4 ( 215 )) on each software ring (e.g., software ring 1 ( 155 ), software ring 2 ( 160 )) is associated with a virtual NIC (e.g., virtual NIC 3 ( 225 ), virtual NIC 4 ( 170 ), virtual NIC 5 ( 220 )), which is associated with a serialization stack (e.g., serialization stack 3 ( 235 ), serialization stack 4 ( 190 ), serialization stack 5 ( 230 )). As described above, each virtual NIC (e.g., virtual NIC 3 ( 225 ), virtual NIC 4 ( 170 ), virtual NIC 5 ( 220 )) implements the functionality of a physical NIC in software; each serialization stack (e.g., serialization stack 3 ( 235 ), serialization stack 4 ( 190 ), serialization stack 5 ( 230 )) is responsible for implementing network layer and transport layer functionality. Further, each serialization stack (e.g., serialization stack 3 ( 235 ), serialization stack 4 ( 190 ), serialization stack 5 ( 230 )) may be operatively connected to a packet destination (e.g., packet destination 4 ( 195 ), packet destination 5 ( 240 ), packet destination 6 ( 245 )). In one or more embodiments of the invention, each packet destination (e.g., packet destination 4 ( 195 ), packet destination 5 ( 240 ), packet destination 6 ( 245 )) corresponds to a container or service configured to send and receive packets from a physical network.
[0032] As shown in FIG. 1 , a software ring (e.g., software ring 1 ( 155 ), software ring 2 ( 160 )) may be created on top of a receive ring (e.g., receive ring n ( 115 )), or a software ring may be created on top of another software ring (e.g., software ring 1 ( 155 ). In one or more embodiments of the invention, software rings (e.g., software ring 1 ( 155 ), software ring 2 ( 160 )) enable packets from the physical network to be differentiated among multiple packet destinations (e.g., packet destination 4 ( 195 ), packet destination 5 ( 240 ), packet destination 6 ( 245 )) corresponding to containers, virtual machines, or services on a single physical host ( 103 ). Those skilled in the art will appreciate that any number of levels of virtual NICs (e.g., virtual NIC 1 ( 125 ), virtual NIC 2 ( 130 ), virtual NIC 3 ( 225 ) virtual NIC 4 ( 180 ), virtual NIC 5 ( 220 )) and software rings (e.g., software ring 1 ( 155 ), software ring 2 ( 200 )) may be created on top of a physical NIC ( 100 ), and that these levels may be structured in multiple ways.
[0033] FIG. 2 shows a serialization stack in accordance with one embodiment of the invention. Various components described above in FIG. 1 may be collectively referred to as a serialization stack ( 275 ). In one embodiment of the invention, the serialization stack ( 275 ) includes a virtual protocol stack ( 260 ) and a virtual serialization queue ( 265 ) and is associated with a virtual NIC ( 255 ). In one embodiment of the invention, the serialization stack ( 275 ) may be bound to one or more receive rings or software receive rings ( 250 ) (depending on the implementation). Further, the virtual serialization stack ( 275 ) may be bound to one or more packet destinations ( 270 ) (e.g., containers and/or services). All of the aforementioned components in the serialization stack ( 275 ) are bound together such that a packet received by the virtual NIC ( 255 ) associated with a particular serialization stack ( 275 ) is sent through the components of the serialization stack ( 275 ) until the packet reaches the packet destination ( 270 ) (e.g., containers and/or services) associated with the particular serialization stack ( 275 ). In one embodiment of the invention, the host includes multiple serialization stacks ( 275 ), each of which includes a virtual protocol stack ( 260 ) and a virtual serialization queue ( 265 ).
[0034] FIG. 3 shows a flow diagram in accordance with one or more embodiments of the invention. First, a network interface card (NIC) is obtained (Step 301 ). As stated above, the NIC is connected to a host and is responsible for sending and receiving packets between the host and a physical network. Once the NIC is obtained, a determination is made regarding the number of virtual NICs needed on the host (Step 303 ). In one or more embodiments of the invention, the number of virtual NICs needed corresponds to the number of packet destinations on the host. Further, in one or more embodiments of the invention, packet destinations on the host correspond to containers, virtual machines, or services that send and receive packets. For example, a virtual NIC may be created for each virtual machine on the host, or a virtual NIC may be created for each application running on each virtual machine on the host.
[0035] Once the number of virtual NICs to be created has been determined, the receive rings on the NIC are assessed (Step 305 ). In one or more embodiments of the invention, a single receive ring corresponds to a single virtual NIC and temporarily stores packets to be sent to the virtual NIC. As a result, when more virtual NICs are needed than there are receive rings on the NIC, one or more soft rings is created to appropriately route packets to the extra virtual NICs.
[0036] Virtual NICs are first created from the NIC (Step 307 ). Next, a determination is made about whether there are fewer receive rings on the NIC than there are virtual NICs (Step 309 ). If not, the receive rings on the NIC are assigned to virtual NICs (Step 317 ). Otherwise, a software ring is created on top of one of the receive rings on the NIC (Step 311 ). A set of software receive rings is then created within the software ring (Step 313 ) and more virtual NICs are created and assigned to the software ring (Step 315 ). As described in FIG. 1 , the software ring is associated with a software classifier, which directs packets to the appropriate software receive rings based on the contents of the fields in the packet headers.
[0037] Once the virtual NICs have associated with the software ring, a determination is made about whether more virtual NICs need to be created (Step 309 ). If so, the process is repeated until all virtual NICs can be assigned a receive ring or software receive ring; then the receive rings and software receive rings are assigned to the virtual NICs (Step 317 ). As stated above, software rings can be arbitrarily created on top of receive rings or software receive rings with the software rings. As a result, different structures involving software rings can be created to handle the same number of virtual NICs.
[0038] FIG. 4 shows a flow diagram in accordance with one or more embodiments of the invention. Initially, packets are received by a NIC (Step 430 ). Next, a classifier associated with the NIC determines which receive ring on the NIC to send the packets to (Step 432 ). The packets are then sent to the appropriate receive ring (Step 434 ) based on the classifier's assessment. At this stage, the processing of the packets differs depending on mode in which the virtual serialization queue (which is bound to the receive ring or connected to the receive ring via a software ring) is operating. The aforementioned virtual serialization queue is associated with the serialization stack bound to the virtual NIC associated with the receive ring. Continuing with the discussion of FIG. 4 , the processing of the packets depends on whether the virtual serialization queue is operating in polling mode or interrupt mode (Step 436 ).
[0039] If the virtual serialization queue is operating in polling mode, then the packets remain in the receive ring until the virtual serialization queue requests a specified number of packets from the receive ring (Step 438 ). In one embodiment of the invention, the virtual serialization queue does not request any packets when there are packets already queued on the virtual serialization queue. In one or more embodiments of the invention, the virtual serialization queue retrieves all packets from the receive ring when a request is made for packets. Those skilled in the art will appreciate that the receive rings store a finite number of packets. Thus, if the receive rings receive packets at a faster rate than the rate at which the corresponding virtual serialization queues requests the packets, the receive rings will eventually fill completely with packets and packets received after this point are dropped until packets on the receive rings are requested and processed.
[0040] Alternatively, if the virtual serialization queue is operating in interrupt mode, then an interrupt is issued to the CPU bound to the receive ring (i.e., the CPU bound to the virtual serialization queue that is bound to the stack associated with the receive ring) (Step 442 ). The packets are then sent to the virtual serialization queue or an intermediate software ring based on the structure of the system.
[0041] Once the packets are requested, a determination is made about whether a software ring is linked to the receive ring (Step 444 ). If so, the packets are sent to the software classifier corresponding to the software ring (Step 446 ), which further sends the packets to the appropriate software receive rings according to the operating mode (Step 434 -Step 444 ). If not, the packets are sent to the virtual NIC (Step 448 ). The virtual NIC subsequently sends the packets to the associated serialization stack (Step 450 ), where the packets are processed and then sent to the packet destination (e.g., a virtual machine, a container, a service, etc.) (Step 452 ).
[0042] The invention may be implemented on virtually any type of computer regardless of the platform being used. For example, as shown in FIG. 5 , a computer system ( 500 ) includes a processor ( 502 ), associated memory ( 504 ), a storage device ( 506 ), and numerous other elements and functionalities typical of today's computers (not shown). The computer ( 500 ) may also include input means, such as a keyboard ( 508 ) and a mouse ( 510 ), and output means, such as a monitor ( 512 ). The computer system ( 500 ) is connected to a local area network (LAN) or a wide area network (e.g., the Internet) (not shown) via a network interface connection (not shown). Those skilled in the art will appreciate that these input and output means may take other forms.
[0043] Further, those skilled in the art will appreciate that one or more elements of the aforementioned computer system ( 500 ) may be located at a remote location and connected to the other elements over a network. Further, the invention may be implemented on a distributed system having a plurality of nodes, where each portion of the invention (e.g., network interface card, virtual network interface card, software ring, etc.) may be located on a different node within the distributed system. In one embodiment of the invention, the node corresponds to a computer system. Alternatively, the node may correspond to a processor with associated physical memory. The node may alternatively correspond to a processor with shared memory and/or resources. Further, software instructions to perform embodiments of the invention may be stored on a computer readable medium such as a compact disc (CD), a diskette, a tape, a file, or any other computer readable storage device.
[0044] While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims. | A method for virtualizing a network interface card includes creating a first plurality of virtual NICs, assigning each of a plurality of receive rings on the network interface card (NIC) to one of the first plurality of virtual NICs, and if the number of virtual NICs is greater than the number of receive rings on the NIC, creating a first software ring corresponding to one of the plurality of receive rings on the NIC, creating a first plurality of software receive rings associated with the first software ring, creating a second plurality of virtual NICs, and assigning each of the first plurality of software receive rings to one of the second plurality of virtual NICs, wherein the plurality of receive rings is less than a sum of the first plurality of virtual NICs and the second plurality of virtual NICs. | 6 |
BACKGROUND OF THE INVENTION
This invention deals with the disposition of fly ash produced when coal is burned in installations such as electric power generating plants. Due to its properties, fly ash is difficult to dispose of primarily because of its tendency to dust and the difficulty of preventing such dust from getting into the atmosphere and creating an environmental hazard.
It has been common practice to moisten the ash with suitable quantity of water or other liquid and after mixing the two, to dispose of the mixture at a sanitary land fill or similiar place of disposal.
A discussion of the problems of creating a satisfactory mixture of liquid and fly ash is contained in U.S. Pat. No. 4,472,198, issued Sept. 18, 1984. As pointed out in this patent, if the ash is insufficiently moistened, dust is still generated and can escape into the atmosphere, whereas if excessive liquid is mixed with the ash, the mixture is difficult to transport and otherwise handle.
U.S. Pat. No. 4,472,198 describes the batching of measured quantities of fly ash and water, and mixing them in a batch mixer to produce mixed batches of fly ash sludge. This patent fails to reveal the necessary apparatus and procedure to produce in a commercial manner, a uniform end product.
It is an object of this invention to provide apparatus that will produce in a reliable manner large quantities of disposable moisturized fly ash material.
A further object is to reduce the time required to produce mixed batches of the resultant sludge and to insure uniform quality from batch to batch.
SUMMARY OF THE INVENTION
The mixer used to blend the moisture with the fly ash is of the type disclosed in my U.S. Pat. No. 4,506,984 issued Mar. 26, 1985. Very little alteration is required to adapt this type of batch mixer to the present use. Combined with the mixer is a volumetric bin or batcher which measures the required amount of fly ash for each batch to be mixed along with a means to measure an amount of water to ensure the proper final liquidity or cohesiveness of the material produced.
The batching system is cycled automatically so that while the mixer is mixing, the batcher is being loaded and as soon as the batch is suitably mixed and discharged from the mixer, a properly measured quantity of fly ash is ready for discharge from the batcher into the mixer.
The discharge of water into the mixer is coordinated with passage of dry material into the inlet opening of the mixer. The quantity of water will vary with the type of fly ash being treated but in all cases can be fed at a rate to insure complete introduction prior to the completion of the mixing cycle.
To insure the batcher is completely filled so that the quantities of material will not vary from batch to batch, probes are used which are actuated by contact with the fly ash as it reaches prescribed levels in the batcher. Valves disposed in the inlet passage to the batcher and the passage from the batcher to the mixer are operated in sequence during the operation cycle. The inlet valve is preferably of the type that can be "jogged" to allow slower feeding of material as the requisite level is approached. Accordingly, the lower of the two probes in the upper portion of the batcher is used to start the jogging of the inlet valve. The higher probe causes the valve to completely close, but it is significant that complete closure of the valve is retarded and the jogging is continued a sufficient time after the upper probe is actuated to allow the material in the batcher to settle, and for some of the air entrained in the ash to escape, thus insuring a full batch is being measured.
Actually the probe which eventually causes closure of the batcher inlet valve has a timer which requires the powder be in constant contact with the probe for the time set on the full probe timer, generally in the range of three to four seconds. If due to settlement of the powder, the probe is uncovered prior to expiration of this period of time, the filling gate is again opened introducing more powder and the full timer is again reset.
Any shrinkage which occurs after the expiration of the timer does not affect the amount of material introduced into the batcher because the gate has now been closed and the desired batch has been measured.
The time allowed for settling of the fly ash powder enables escape of sufficient entrained air with the result that the settled fly ash has a density that does not vary materially from batch to batch. This time also enables the level of the ash to stablize so that measurements are made while the material is in a static state. As a result the size of the batches can be repeated and if the same amount of water is added for each batch, the final moisture will be consistent.
While this form of control is not as accurate as when batches are weighed, where an accuracy of plus or minus one percent may be specified, it is accurate enough for present purposes and is much more economical and more rapid in its operation. Experience has indicated it is possible to maintain the variation in size of batches to be in the range of about five percent, which insures the final moisturized end product is acceptable for disposal purposes.
Equally important with accurate filling of the batcher is the complete discharge of the batcher contents to maintain consistant size of batches. Accordingly, when the gate between the batcher and the mixer is opened, air is introduced through bin pads to assist in discharge of fly ash from the batcher. When the material in the batcher reaches a level uncovering the empty level probe, a bin vibrator is actuated which prevents bridging of the material in the throat of the batcher and assists in its discharge.
The system is sealed to prevent escape of fly ash during any portion of its passage through the equipment. During charging of the mixer, air is vented from the mixer to the batcher thus avoiding the build up of pressure in the mixer. During charging of the batcher, air is vented from the batcher to the fly ash holding silo or to the bag house; a check valve in the vent from the mixer to the batcher prevents flow of air from the batcher to the mixer during charging of the batcher.
It is essential that the batcher be completely filled, and completely emptied, during each cycle of the systems operation. Otherwise the quantity of water used will not produce the required density of the final product. It is also essential that the flow of the material into the batcher be shut off when the proper volume has been reached to insure a constant solids content.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of the combined batching and mixer package;
FIG. 2 is a side elevation of the apparatus shown in FIG. 1; and
FIG. 3 is a schemating wiring diagram for controlling the level of ash in the volumetric batcher.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The drawings generally depict the arrangement of the batcher 11 above one side of the mixer 12. As shown in FIGS. 1 and 2, the batcher has a rectangular upper section 13 which is provided with a window 14 through which the level of the fly ash can be viewed. The lower position of the batcher has three sides that taper downwardly, the slope of the front side 15 being roughly similar to the slope of the two end sides 16. The back side 17 is vertical. Suitable framework 18 provides support for the batcher with the legs resting on the ground or any suitable support for the batcher and mixer. If the mixer is to discharge into a truck, the mixer and the batcher are mounted on a platform under which the truck can be driven to receive one or more mixed batches of moistened fly ash material.
The outlet at the lower end of the batcher 11 communicates with a gate 21 which in this instance includes a rotary plug valve actuated by the air cylinder 22. The lower end of the gate is connected to the inlet of the mixer by means of a dust boot 23 which accommodates any misalignment vertically or laterally between the bin and the mixing chamber.
As shown in the broken away section in FIG. 1, extending through the top 24 of the batcher are two probes 25 and 26, the probe 25 extending to a lower level than the probe 26.
The probes 25 and 26 are utilized to produce signals indicating the presence of material within their range. They are solid state capacitance probes of a type commonly used for this type of application. The probes actuate power relays which in turn are utilized to operate the air cylinder 27 that oscillates the rotary valve 28 located in the inlet gate 29.
Referring to the probe 25, the presence of fly ash in the batcher reaching a level to which the probe responds will cause the valve 28 to be "jogged", i.e. oscillated between an open and closed position. This retards the passage of material through the gate and enables it to be closed with more accurate cut-off at the end of the charging cycle.
The probe 26 serves to indicate when the level of material reaches its elevation that the oscillation of the valve 28 should cease and complete closure should occur. It has been observed, however, that even when this probe is actuated, the material in the batcher continues to settle and therefor, jogging of the valve should be continued for up to three or four seconds, with the result that entrained air is removed, variations in density are eliminated and more uniform quantity of fly ash is measured from batch to batch. Consequently more uniform quantity of moisture will be obtained in the final mixtures of different batches.
To prevent failure of the probe 26 to cause closure of the valve 28, an over fill probe 30 is also provided which is used only as an emergency to protect against malfunction of probe 26.
As previously mentioned, the mixer 12 is of the type described in my U.S. Pat. No. 4,506,984. Material is introduced from the dust boot 23 through an opening in the cover 35 on the top of the mixer. This opening is off to one side and is sealed to prevent escape of dust. Also passing through the cover are the pipes 36 that provide water to the nozzles that discharge water over different areas of the surface of the batch being accumulated in the mixer. It is important that water be supplied concurrently with the charging of the mixer and be continued until after all material is in the mixer so that the portions of the rotating blades in the mixer which extend above the batch can be flushed to prevent build up of material. Flow through the pipes 36 can be staggered so that water can be evenly distributed in different parts of the mixer and the final rate of flow for instance through two of the pipes can be reduced prior to final closure of the measuring valve controlling the flow through the pipe supplying the last amount of water. In addition to the measuring valves which are shut when the requisite quantity of water has been supplied, there is the hand valve 37 for shut off and drainage of the water system. In the system here described, there are two solenoid flow control valves, each serving two nozzles with the timing of one slightly over-lapping the period of discharge from the other.
The mixer is provided with the customary discharge gate, as shown in U.S. Pat. No. 4,165,185, which is swung across the opening in the hopper 38 to permit discharge when the gate is opened and to prevent such discharge when the gate is closed. There is no danger of unmixed fly ash escaping to the atmosphere through this gate since the gate is only opened after the fly ash is properly mixed.
To facilitate discharge of fly ash from the batcher 11, the sloping walls 15 and 16 are provided with bin flow pads 41 introduce low pressure, fluidizing air along the inner sides of the sloping walls in a well known manner. The blower 38' supplying air to the flow pads 41 is started at the same time that the gate 21 is opened. When the level has dropped to a point exposing the probe 40 which extends through the lower portion of the vertical wall 15 of the batcher, a vibrator 42 mounted on the outside of the batcher starts to vibrate. This prevents bridging of the fly ash in the throat of the batcher After a suitable time, the vibrator stops, the blower is turned off and the gate 21 is closed.
During the charging of the mixer, air is vented from the top of the mixer through the hose 43 to the fitting 44 on the top of the batcher. In this fitting is a check valve 45 which enables air to be vented from the mixer to the batcher, but which prevents movement of air in the opposite direction from the batcher to the mixer. Instead, when the batcher is being charged, air is vented to either the silo from which the fly ash is supplied, or to the bag house. A suitable hose 46 is provided for this purpose.
Referring now to FIG. 3, there is shown a schematic wiring diagram for controlling the above described components. In operation, and assuming that batcher 11 is completely empty and ready to start a new cycle, a signal from terminal 49 of a main controller such as a programmable controller passes through normally closed overfill probe timer relay 50 and then through normally closed jog probe timer relay 51 to open fill gate 28. Upon the opening of gate 28, fly ash flows into the batcher in a fill operation. As fly ash flows into the batcher, the fly ash eventually completely covers empty probe 40. At this time empty probe 40 closes normally closed empty probe timer relay 52 and opens normally open empty probe timer relay 53 in preparation for later discharge as will hereinafter be described. An empty probe timer 56 is reset at the same time relay 52 is closed and relay 53 is opened, and a normally closed empty probe timer relay 57 is closed. Also, a normally open empty probe timer relay 58 is closed and a normally closed empty probe timer relay 59 is opened.
Fly ash continues to flow into batcher 11 until it reaches jog probe 25. At this point, jog probe 25 activates jog probe timer 54 and activates jog light 55 to indicate to an operator that jogging is taking place. As jog probe timer 54 cycles, it causes relay 51 to continuously pulse on and off depending upon the cycle time of timer 54. Thus, fill gate 28 jogs open and closed depending upon the pulse from timer 54 to slow the flow of fly ash into the batcher.
When the fly ash inside the batcher reaches full probe 26, full probe 26 actuates a full probe timer 60 which in turn closes a normally open full probe timer relay 61. At the same timer timer 60 also closes a normally open full probe timer relay 62. Should the full probe 26 become uncovered, due to settling of the fly ash or otherwise, prior to the end of the timing period of the timer 60, the timer is reset and can complete its timing cycle cnly if the probe remains covered during the full timing period.
After receiving the full input signal from terminal 64, the main controller automatically sends a discharge signal through terminal 65 to open discharge gate 21. Since relay 52 had previously been closed by the covering of empty probe 40, the signal from terminal 65 reaches discharge gate 21 and opens gate 21. At the same time the discharge gate open signal passes through relay 57, which was previously closed by the covering of empty probe 40, to cause the aeration valve 66 to open so that the fly ash within the batcher is aerated to aid in its discharge. At the same time an aeration light 67 is energized to indicate to an operator that aeration is taking place.
Discharge gate 21 remains open as the fly ash is discharged, and once the level of the fly ash inside the batcher uncovers empty probe 40, empty probe 40 energizes timer 56 which in turn immediately closes relay 53 to begin operation of vibrator valve 41. At the same time a vibrator light 74 is energized to indicate to an operator that vibration is occurring. During the predetermined cycle time of timer 56, the batcher is vibrated to shake loose any fly ash that may be caught on the sides of batcher while at the same time the fly ash continues to discharge through gate 21. At this time, timer 56 also opens relay 57 to close aeration valve 66, turn off light 67 and stop aeration. At the end of the predetermined cycle time for timer 56, timer 56 opens relay 52 and relay 53 to close the discharge gate 21 and vibrator valve 41, respectively. Fly ash discharge and vibration of batcher is thus stopped. At the same time, timer 56 closes relay 58 which in turn energizes a light 68 through relay 59 indicating to an operator that batcher is empty. Also, a signal is sent through terminal 69 to the automatic main controller to indicate that batcher is empty. The main controller then sends a signal through terminal 49 to open fill gate 28 as previously described. This cycle continues as described for any desired number of batches.
As previously described, overfill probe 30 is a safety device for shutting down the system should the batcher be overfilled for some reason. As shown in FIG. 3, if fly ash within the batcher reaches overfill probe 30, probe 30 actuates an overfill probe timer 70 and at the same time energizes a light 71 to indicate to an operator that there is an overfill condition. Upon the actuation of timer 70, timer 70 will open relay 50 which will interrupt the signal from the main controller to fill gate 28 and cause fill gate 28 to close. The system will thus be shut down until the cause for the over fill condition is determined and corrected.
As shown in FIG. 3, main lines 72 and 73 are connected to opposite terminals of a power source. Typically, this power source is a 120 volt, single phase, 60 Hz power source which is conventionally available.
The following time cycle is typical of the operation of the equipment. During the first 20 seconds of the cycle after the starting signal, the batcher is filled. Assuming the average batch consists of approximately 130 cubic feet of fly ash, this charging time has been found to be reliably adequate with the equipment illustrated. An additional 20 seconds is required to discharge the batcher, with the batch vibrator being operated the last 5 seconds. Simultaneously with the discharge from the batcher, water is supplied to the mixer. There are 3 stages of water introduction, the last valve supplying water a few seconds after the discharge gate from the batcher is closed.
The mixing cycle starts simultaneously with the discharge of the batcher, but the initial part of the total 75 second mixing cycle indicated includes mixing of only a small portion of the batch and the final half of the mixing cycle which occurs during discharge from the mixer occupies nearly all of the mixer discharge cycle of 421/2 seconds.
It is not necessary to discharge all the contents of mixer prior to the end of each cycle as long as a new batch of fly ash of the desired amount is introduced with the desired quantity of water, the mixer discharge gate may be closed prematurely. This allows a total time of 45 seconds except for the last batch which requires 65 seconds to completely discharge the mixer at the end of the total period of operation.
It will be noted the second and subsequent filling of the batches each is allowed 20 seconds, which results in the fly ash being held in the batcher for a portion of the mixing time in excess of the 20 second filling time. During this time, there may be further settling of the fly ash, augmented perhaps by vibration from the mixer, and it is even possible the level will disappear beneath the window 14, but such settling is of no consequence because the batch has been measured under conditions enabling subsequent batches to contain approximately the same quantity of fly ash.
Using this cycle, it should be possible to produce 130 tons of mixed material per hour. If the material weighs 50 pounds per cubic foot, 130 tons equal 5,200 cubic feet of ash. To produce this quantity would require continuous cycles of 40 batches per hour. | A volumetric batcher is combined with a batch mixer so that similiar batches of powdered fluidizable material such as fly ash can be mixed with constant quantities of water resulting in mixtures having the same moisture. This enables their disposal at a land fill site or the like. To insure that the material in the batcher is settled to the desired degree before the inlet valve is closed, a high level indicator is provided which jogs the inlet valve to retard the rate of flow and this valve is allowed to continue to jog until a short period of time has elapsed during which the high level probe is constantly under the influence of the fly ash, at which time it is completely closed. Additional means are provided for insuring complete discharge from the batcher, measuring and timing the flow of water and removing air from the mixer and batcher during charging operations. | 1 |
TECHNICAL FIELD
This invention relates to a system and method for pumping fluids, such as water. More particularly, the present invention relates to a self-cleaning screening system and method that reduces the collection of debris in water pumps and other devices in a fluid pumping system.
BACKGROUND
In order to pump fluids, from one location to another, pipes are used as fluid conduits, and pumps are used to force fluid through the pipes. For example, in a pool or spa (or hot tub), a pumping system may be used to draw water into an inlet located in the pool or spa and to force the water out of an outlet back into the pool or spa. (Those skilled in the art will understand that the terms “spa” and “hot tub” are generally used interchangeably. For simplicity, the remainder of this description will use only the term “spa,” which will be understood to encompass spas and hot tubs.) Generally, such pumping systems will include one or more skimmers and/or filters located downstream from the inlet and upstream from a pump to prevent debris from reaching the pump, as build-up of debris at a pump's input may render the pump inoperable.
Some debris, however, may not be trapped by the skimmer and filter, thereby allowing such untrapped debris to reach the pump. As a result, some pumping systems have incorporated a screen (or screen-trap) upstream of the pump's input in order to capture untrapped debris. While these screens do reduce and even prevent debris from reaching the pump, they must be manually cleaned and maintained, making them cumbersome and costly.
Accordingly a need exists for a pumping system that includes an effective pump screen that can be cleaned and maintained automatically. The present invention provides such a pumping system.
SUMMARY
The present invention is a pumping system and method that reduces the amount of debris that may clog and even render inoperable a pump or other apparatus in a fluid pumping system.
The invention may be used in spa, hot tub, swimming pool, pond, aquarium, chemical treatment plant, or water treatment plant with a pumping system that includes, for example, a circulation pump and a high-speed pump. Circulation pumps are generally small, efficient pumps that are used for constant fluid circulation, while high-speed pumps are powerful pumps that are turned on periodically to operate, for example, water jets in a pool or spa. According to an embodiment of the invention, a high-speed pump may be turned on periodically to remove debris trapped in the screen, thereby automatically cleaning the screen.
For convenience, the remainder of this description will refer to a “water” pumping system in a spa. But it will be understood that the present invention is not limited to spa pumping systems, but rather may be used in any suitable fluid pumping system, including swimming pools, ponds, aquariums, chemical plants, or water treatment plants, in which fluid is circulated by a fluid pumping system. In addition, the description refers to a “screen” or “screening” apparatus and method. It will be appreciated by those skilled in the art that the terms “screen” and “screening” are not intended to limit the invention in any way, but rather are broad terms intended to encompass any apparatus or device that can be used to separate, sift, block, or trap any debris or particulate matter carried by the water passing through the pumping system, including without limitation screens, sieves, filters, strainers, and sifters. Moreover, as embodied in this invention, the “screen” may operate passively or actively, or using a combination of both. An example of a passive “screen” would be a sifting grid located within a pipe. An example of an active “screen” would be a motorized filtration system.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of a spa with a cutaway section showing parts of a pumping system in accordance with an embodiment of the present invention.
FIG. 2 is a plan view of a pumping system in accordance with an embodiment of the present invention for use in a spa.
FIG. 3A shows an embodiment of the screen in accordance with an embodiment of the present invention.
FIG. 3B is a cross-sectional view along line 3 B— 3 B of FIG. 3 A.
FIG. 4A shows an alternative embodiment of the screen in accordance with an embodiment of the present invention.
FIG. 4B is a cross-sectional view along line 4 B— 4 B of FIG. 4 A.
Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the present invention.
FIG. 1 shows a spa 100 , including a cut-away section that reveals part of a water pumping system 101 used in the spa 100 . The spa includes a vessel 101 , in this case, a tub, for holding water. Those skilled in the art will appreciate that the tub is only an example of a vessel in accordance with the present invention. The various applications in which this invention may be used (e.g., swimming pools, aquariums, ponds) may have a different vessel, at least in shape and dimensions.
In accordance with an embodiment of the present invention, the pumping system 101 of the spa 100 includes a circulation pump 102 , a jet pump 106 , and a screen 116 . Examples of suitable circulation pumps 102 include 98-Watt Circulation Pump manufactured by Laing Thermotech, Inc., as well as circulation pumps made by Grundfos, 3131 N. Business Park Ave., Freeno, Calif. 93727, or by Cal Pump, 13278 Ralston Ave., Sylmar, Calif. 91342. Examples of suitable jet pumps are the 3.0 or 4.0 HP 2-speed Sta-Rite pump, or single-speed pumps commonly used to filter pools or pump wells. The circulation pump 102 may be connected by a pipe 110 to circulation outlets 114 within the spa 100 , and the jet pump 106 may be connected by a pipe 112 to jets 104 within the spa 100 . A filtration inlet pipe 108 may be used to feed water from within the spa 100 to the input of the screen 116 , and a pipe 118 may be used to connect the input of the jet pump 106 to the screen 116 and the inlet pipe 108 at or near the input to the screen 116 . The output of the screen 116 may also be connected to the input of the circulation pump 102 by another pipe 120 . The arrows in FIG. 1 indicate the direction of flow of water through the pumping system 101 .
As explained above, the circulation pump 102 is a relatively small, efficient pump for continuously circulating the spa water using the circulation outlets 114 . A separate jet pump 106 , which is relatively large and high-powered in comparison to the circulation pump 102 , is periodically used to pump water to the jets 104 . Such a two-pump system may be more efficient than using a single pump for both circulating water and providing water at high pressure to the jets 104 . This potential increase in efficiency results because the efficient low-power circulation pump 102 may be kept running at all times to keep the spa clean, while the high-power jet pump 106 , which generally requires substantially more power than the circulation pump 102 , need only be turned on periodically when operation of the jets 104 is desired.
The screen 116 in the embodiment of FIG. 1 may be used to trap or filter debris being carried in the water passing through the inlet pipe 108 . Those skilled in the art will appreciate that spas generally include a skimmer and/or filter (not shown in FIG. 1) located between the inlet pipe 108 and the water in the spa 100 . Such a skimmer/filter is used to trap debris in the water of the spa 100 so that debris will not reach the spa's pumps. However, in conventional pumping systems, some debris is able to bypass the initial skimmer/filter. Debris that bypasses the skimmer/filter may build-up on the impeller of the circulation pump 102 , clogging the circulation pump 102 and even rendering it inoperable. Build-up of debris on the circulation pump 102 means that the pump 102 must be cleaned, which was done manually in conventional systems. Thus, in accordance with an embodiment of the present invention, the screen 116 is placed in the pumping system before the input to the circulation pump 102 to reduce the amount of water-borne debris that would otherwise reach the circulation pump 102 . The jet pump 106 may then be operated periodically or as necessary to pull debris out of the screen 116 and divert the debris to the primary filters (not shown) of the spa 100 . In addition, the powerful jet pump 106 may pump the debris back into the spa 100 , where it may be trapped by the skimmer/filter.
FIG. 2 shows an exemplary spa pumping system 200 in accordance with an embodiment of the present invention. Those skilled in the art will appreciate, however, that the invention is not limited to spas; rather, the spa embodiment of the invention is merely shown as an example, and the invention can be applied to any filtered body of fluid, e.g., water. FIG. 2 shows a portion of a spa 204 having a surface 205 for holding water, with the water line being indicated by reference numeral 202 . The spa 204 is shown separately in the upper left and lower right portions of FIG. 2, but those skilled in the art will recognize that both portions are part of the same spa 204 . While not required, the pumping system 200 may include a skimmer 206 and a preliminary filter 208 . As indicated by the arrows in the skimmer 206 and preliminary filter 208 , water from the spa 204 passes through the skimmer 206 and the preliminary filter 208 , both of which are designed trap at least some of the debris present in the water so that the debris will not reach the downstream parts of the pumping system 200 . The downstream parts may include a screen, 222 , a circulation pump 226 connected by pipe 228 to a heater 230 , and an ozone generator 232 connected by a pipe 234 to an ozone injector 238 , which is also connected to the heater 230 by a pipe 236 . The optional ozone generator 232 and heater 230 may be coupled to the ozone injector 238 , which outputs heated, ozonated water into the spa 204 via an output pipe 240 (see also reference numeral 242 ).
Some debris may escape the optional skimmer 206 and preliminary filter 208 and be carried in the water through pipes 210 , 220 , and 224 to a circulation pump 226 . Accordingly, screen 222 is provided in the pumping system 200 to trap at least some of the debris that escapes the skimmer 206 and filter 208 before the debris can reach the input to the circulation pump 226 or any downstream features in the pumping system 200 , such as the heater 230 or ozone injector 238 . A jet pump 216 , which may be connected by pipe 214 to pipes 210 and 220 using a T-junction 212 or other suitable plumbing device, may be run periodically or as needed to pull trapped debris from the screen 222 and divert the debris to the primary filters of the spa 204 ; for example, the jet pump 216 may pump the debris back into the spa water 202 , where it may be trapped by the skimmer 206 and filter 208 . As such, the screen 222 may be automatically cleaned, obviating the need for cumbersome, time consuming, expensive manual cleaning of the screen 222 .
In the embodiment of FIG. 2, the jet pump 216 is coupled to the screen 222 via pipes 220 and 214 and junction 212 . It will be appreciated, however, that the jet pump 216 and its coupling to the screen 222 could be configured differently. For example, pipe 214 could be eliminated. Alternatively, pipes 220 and 214 as well as junction 212 could be eliminated, with the jet pump 216 thus directly connected to the screen 222 .
As those skilled in the art will appreciate, the screen 222 may be formed in a variety of ways. For example, as shown in FIGS. 3A and 3B, if the pipes 210 and 220 are cylindrical, a perforated, circular disk 302 may be inserted or integrally formed in pipe 220 , so that the planar surface of the disk 302 is orthogonal to the flow of water. The perforated disk 302 has sufficient perforations to allow water to pass through the pipe 220 and to trap debris carried in the water. The number and dimension of the performations may be altered as necessary to permit sufficient water flow. Of course, if pipe 220 has a different cross-sectional shape, for example, a square shape, the disk 302 would have a corresponding shape. FIGS. 4A and 4B show an alternative embodiment of the screen 222 , in which the screen 222 is formed from a flexible mesh 402 disposed over an opening 404 of pipe 220 . In this alternative embodiment, pipe 220 is separate from, and inserted into, T-junction 212 , allowing the flexible mesh 402 to be secured across the opening 404 . FIG. 4B is a cross-sectional view along line 4 B— 4 B in FIG. 4A, showing the flexible mesh 402 disposed over opening 404 in a manner that allows water to pass through the mesh 402 while at the same time trapping debris in the mesh 402 .
A variety of methods may be used to effect operation of the jet pump 216 and thus automatic cleaning of the screen 222 . One method is to provide a conventional timer 244 , coupled to the jet pump 216 . The timer 244 may be set up to turn the jet pump 216 on and off periodically, for example, once a day for five minutes, using, for example, a conventional switch or relay 245 on the jet pump 216 . Such periodic running of the jet pump 216 allows the screen 222 to be cleaned automatically, as desired. The switch 245 could also be equipped with a manual feature, in addition to the timer 244 , allowing the jet pump to be manually turned on and off to clean the screen 222 , as needed, but without the need to manually remove the screen for cleaning. Alternatively, a conventional flow-sensing device 248 could be located before (or after) the circulation pump 226 . The flow sensing device 248 could be coupled, for example, to a conventional controller 246 that, based on the flow rate of water in pipe 224 (or pipe 228 ), operates to turn the jet pump 216 on and off. As yet another alternative, a pressure sensing device, current or voltage sensing device, or other monitoring device could be provided in the pumping system 200 to monitor operation of the circulation pump 226 , in known fashion. The pressure sensing device, current or voltage sensing device, or other monitoring device would then be coupled to the controller 246 . As performance of the circulation pump 226 is impeded by the build-up of debris in the screen 222 , the controller 246 , monitoring such impeded performance, could operate to turn the jet pump 216 on and off, using, for example, the switch or relay 245 . The controller 246 and sensor could be configured such that the controller turns on the jet pump 216 when the pressure, current, voltage, or other sensed parameter reaches, exceeds, or dips below a predetermined threshold level, in known fashion. Once the controller 246 determines that the sensed parameter has dropped back below or has gone back above the threshold level (for example, by a given amount), the controller could then operate to turn off the jet pump 216 , in known fashion. Operating the jet pump 216 would then act to remove the trapped debris from the screen 222 , allowing the circulation pump 226 to resume normal operation. It will be recognized from the above description that any time the powerful jet pump 216 is turned on and the circulation pump 226 is off, the jet pump 216 will pull water back through the jet pump 216 and thus clear the screen 222 of debris.
Those skilled in the art will recognize that other methods of automatically operating the jet pump 216 exist. For example, an optical sensor could be used to monitor the amount of debris trapped in the screen 222 . All such alternatives fall within the scope and spirit of the present invention.
Accordingly, using the present invention, any debris that is trapped in the screen 222 may be automatically cleaned using the jet pump 216 . This obviates the need for a human to manually clean the screen 222 . It will be appreciated, however, that the invention is not limited to a single jet pump. Some pumping systems, for example, in a spa, may use multiple jet pumps. Any one or a combination of such jet pumps could be used to effect cleaning of the screen 222 . Further, the invention is not limited to the use of a jet pump 216 to clean the screen 222 . Any suitable pump may be used to clean the screen 222 ; for example, a high-powered pump used for draining the pool or spa could be operated periodically in order to automatically clean the screen 222 . Moreover, the jet pump 216 may be replaced by any device capable of sucking or blowing debris from the screen 222 .
In an alternative embodiment of the present invention, a dedicated high-power cleaning pump could be placed in line 210 . A check valve is then installed in line 214 . The dedicated pump in line 210 is then started when debris is to be removed from the screen 222 . As another alternative, instead of using the jet pump 216 , the circulation pump 226 may be run in reverse to clean the screen 222 . In this alternative, the filter 208 could be removed, and the debris would flow back into the spa 204 . The debris could then be removed from the spa water 202 manually or by replacing the filter 208 .
A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, the T-junction 212 shown in FIG. 2 need not be used; instead, pipes 210 , 220 , and 214 may be an integral T-pipe. Moreover, several alternative embodiments have been described for controlling operation of the jet pump 216 to remove debris from the screen 222 . Any one, or a combination, of those embodiments may be used to control the jet pump 216 . Accordingly, other embodiments are within the scope of the following claims. | A system and method for reducing the collection of debris in a fluid pumping system. The system and method may be used in pools, spas, or other applications in which fluids are circulated through a fluid-containing vessel. The system includes a first pump that circulates fluid. A screen is coupled to the input of the first pump and acts to prevent debris from reaching the first pump. A second pump may be used to remove debris from the screen. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to the manufacture of polishing cloths of the class to be used with an abrasive powder or slurry for polishing various work pieces on a lapping machine.
Japanese Patent Publication No. 30158/1979 discloses a polishing cloth of the above type made of microporous polyurethane sheet materials. The microporous polyurethane sheet is produced using the well-known wet coagulation process by impregnating a substrate fabric with a solution of polyurethane elastomer in a solvent, and immersing the impregnated fabric in a liquid which is a nonsolvent for polyurethane elastomer but miscible with said solvent so that polyurethane solution is coagulated into a microporous structure. The polishing cloth is produced by compressing the resulting sheet at a temperature above the softening point of the polyurethane elastomer to impart the sheet with an adequate hardness.
Experiments have shown, however, that the resulting polishing cloths produced by the above known process have certain disadvantages and thus are far from satisfactory. The compression under heat tends to partially collapse pores and reduce their sizes in terms of greatly decreased air-permeability. In addition, the pores may be easily clogged with abrasive powder particles with the result being decreased polishing efficiency and also increased scratches on the work piece surfaces. If the polishing cloth is too soft, it is difficult to maintain flatness accuracy free from relief on the polished surface particularly when the polishing is carried out at high speeds under high pressures.
SUMMARY OF THE INVENTION
It is, therefore, the principal object of this invention to provide a process for manufacturing a microporous polyurethane based polishing cloth having improved properties.
According to the invention, there is provided a method for manufacturing a polishing cloth comprising the steps of impregnating a nonwoven fabric sheet made of a synthetic fiber having a melting point higher than that of polyurethane elastomer with a solution containing polyurethane elastomer, wet-coagulating the impregnated sheet to form a microporous composite sheet, and heating the resulting sheet in an essentially uncompressed condition at a temperature higher than the softening point of said polyurethane elastomer for a sufficient length of time to impart to the sheet a degree of hardness greater than 80 and an air-permeability greater than 25 cc/cm 2 /second.
BRIEF DESCRIPTION OF THE DRAWING
The single FIGURE shows the difference in the polishing rates of a polishing cloth according to this invention and a prior art polishing cloth over a period of five hours.
DETAILED DESCRIPTION OF THE INVENTION
Nonwoven fabrics which may be used in this invention are those made from synthetic fibers having a melting point higher than that of polyurethane elastomer. Examples of fiber materials include polyesters such as polyethylene terephthalate and its copolymers, and nylons such as nylon 6 and nylon 66. Short staple or filaments are employed. The fabrics preferably have a thickness from 2 to 10 mm and a basis weight from 300 to 1500 g/m 2 .
The polyurethane solution used for impregnating the nonwoven fabric may be those conventionally used for the manufacture of synthetic leather by the wet coagulation process. The solution may additionally contain other polymers such as polyvinyl chloride, polymethyl methacrylate and acrylonitrile-styrene rubber in an amount of up to equal parts by weight of polyurethane elastomer. The polymer concentration in the polyurethane solution may vary depending upon the desired deposit amount of polymer to the fabric and generally ranges from 5 to 30% by weight. The deposit amount of polymer, in turn, varies with the intended use of particular polishing cloths and generally ranges from 40 to 260% by weight of the substrate fabric on dry basis. After impregnating with the polyurethane solution, the fabric may be treated by the well-known wet coagulation technique, washed with water and then dried to give a microporous composite sheet having open cell structure. The resulting microporous sheet is preferably sliced adjacent its opposite surfaces to remove skin layers. If necessary the remainder may be further sliced into two or more sheets each having a thickness of 0.5 to 5 mm. Alternatively, this slicing operation may be carried out after the entire microporous sheet has been heat-treated as fully discussed below.
We have found that when the polyurethane microporous composite sheet is heated at a temperature higher than the softening point of polyurethane elastomer under essentially uncompressed condition, it is possible to increase the air-permeability of the sheet while imparting an adequate hardness to the sheet. The porosity of the microporous sheet substantially remains unchanged by this heat treatment. This indicates that walls defining micropores are partially fused together to form larger pores. The temperature at which the microporous sheet is treated may vary with the length of treating time and generally ranges from 180° C. to 250° C. The treating time generally ranges from 2 to 45 minutes. The lower treating temperature requires the longer treating time and vice versa. Of course a temperature higher than the melting point of the material of substrate fabric should be avoided.
This heat treatment is preferably carried out by blowing hot air or hot inert gas under such conditions that the microporous sheet is not compressed at all or compressed slightly, i.e. less than 10% in the thickness. This heat treatment is continued until the resulting product has a degree of hardness greater than 80 and an air-permeability greater than 25 cc/cm 2 /second as determined by Japanese Industrial Standard (JIS) K 6301- 1975, 5.2 and L 1096-1979, 6.27, respectively, as described hereinafter. These parameters are required for polishing work pieces without clogging while maintaining surface flatness and preventing relief.
The heat treatment of this invention may enhance the hardness and air-permeability of the cloth to at least 1.02 times, preferably 1.05 to 1.2 times and at least 1.5 times, preferably 1.6 to 2.3 times, respectively, greater than their original values.
After the heat treatment, the resulting product may be buffed to finish into smooth surfaces.
The following examples will further illustrate this invention. All percents therein are by weight unless otherwise indicated.
EXAMPLE 1
A polyester staple nonwoven fabric having a thickness of 5 mm and a basis weight of 700 g/m 2 was impregnated with a solution of polyurethane elastomer (TC-66, sold by Dainippon Ink And Chemicals, Inc.) in dimethylformamide having varying concentrations at a rate of 6.1 kg/m 2 . The impregnated sheet was immersed in a 7% aqueous solution of dimethylformamide to coagulate the polyurethane solution, thoroughly washed with water and then dried. The resulting microporous composite sheet was sliced adjacent the opposite surfaces to remove skin layers. The remainder was further sliced at the center into two sheets each having a thickness of 2 mm.
The sliced sheets were heat-treated by blowing hot air having a temperature of 230° C. for 4 minutes and then buffed to finish into smooth surfaces. (Run Nos. 1-3)
The above process was repeated except that a solution of a mixture (8:2) of polyurethane elastomer and polyvinyl chloride resin dissolved in dimethylformamide at a concentration of 18% was used. (Run No. 4)
For comparative purposes, the sliced microporous composite sheets as used in Run Nos. 1-3 were treated by the method disclosed in hereinbefore cited Japanese Patent Publication No. 30158/1979. The sheets were placed in a hot press and heated at 165° C. at a pressure of 8 kg/cm 2 for 30 seconds to a compression degree of 53%. (Run Nos. 5-7) Properties of samples before and after the heat treatment are shown in Table 1 below.
TABLE 1__________________________________________________________________________Run No. 1 2 3 4 5 6 7__________________________________________________________________________Polymer concentration, % 10 15 18 18 10 15 18Amount of solid deposit, % 85 130 155 155 85 130 155Hardness, degreeBefore treatment 69 76 82 85 69 76 82After treatment 81 83 87 90 91 93 94Ratio of After/Before 1.17 1.09 1.06 1.06 1.32 1.22 1.15Air-permeability, cc/cm.sup.2 /sec.Before treatment 22.0 16.5 13.4 13.4 22.0 16.5 13.4After treatment 44.7 37.2 27.4 26.1 1.11 0.72 0.72Ratio of After/Before 2.03 2.25 2.04 1.95 0.05 0.04 0.05Porosity, %Before treatment 81.0 77.2 75.2 68.2 81.0 77.2 75.2After treatment 78.3 79.5 75.0 68.9 41.4 39.5 39.2Ratio of After/Before 0.97 1.03 1.00 1.01 0.51 0.51 0.52Pore size, μmBefore treatment 45 25 20 17 45 25 20After treatment 150 85 80 65 25 15 10Ratio of After/Before 3.3 3.4 4.0 3.8 0.6 0.6 0.5Pore sectional area, μm.sup.2Before treatment 1635 640 345 278 1635 640 345After treatment 7675 3835 2720 1710 340 280 240Ratio of After/Before 4.7 6.0 7.9 6.2 0.2 0.4 0.7__________________________________________________________________________
EXAMPLE 2
The procedures of Run Nos. 1-3 and 5-7 in Example 1 were repeated except that the polyester nonwoven fabric was replaced by a nylon 6 nonwoven fabric (Run Nos. 8-10 and 12-14, respectively) or a nylon/polyester (1:1) mixed fiber nonwoven fabric (Run Nos. 11 and 15, respectively) and the heat treatment was carried out at 210° C. for 4 minutes.
Properties of samples before and after the heat treatment are shown in Table 2 below.
TABLE 2__________________________________________________________________________Run No. 8 9 10 11 12 13 14 15__________________________________________________________________________Polymer concentration, % 10 15 18 18 10 15 18 18Amount of solid deposit, % 85 130 155 155 85 130 155 155Hardness, degreeBefore treatment 72 76 83 80 72 76 83 80After treatment 81 85 88 87 93 93 96 95Ratio of After/Before 1.13 1.11 1.06 1.09 1.29 1.26 1.16 1.19Air-permeability, cc/cm.sup.2 /sec.Before treatment 18.5 14.8 12.8 10.9 18.5 14.8 12.8 10.9After treatment 35.3 29.5 26.5 25.3 1.31 0.92 0.65 0.65Ratio of After/Before 1.91 1.99 2.07 2.32 0.07 0.06 0.05 0.06Porosity, %Before treatment 78.2 73.0 71.3 70.3 78.2 73.0 71.3 70.3After treatment 75.1 72.3 69.2 69.0 38.2 32.1 30.1 30.7Ratio of After/Before 0.96 0.99 0.97 0.98 0.49 0.44 0.42 0.44Pore size, μmBefore treatment 40 20 17 17 40 20 17 17After treatment 145 70 60 60 25 15 10 10Ratio of After/Before 3.6 3.5 3.5 3.5 0.6 0.8 0.6 0.6Pore sectional area, μm.sup.2Before treatment 1550 500 300 285 1550 500 300 285After treatment 6200 2620 1860 1840 380 250 220 200Ratio of After/Before 4.0 5.2 6.2 6.5 0.2 0.5 0.7 0.7__________________________________________________________________________
As can be seen from Table 1 and Table 2, the treatment according to this invention greatly increased the air-permeability, pore size and pore sectional area, whereas the known technique decreased these characteristics significantly. The porosity remained substantially unchanged by the treatment of this invention but decreased about one half by the known technique. Both techniques were effective to improve the hardness.
In the above tests, hardness was determined by the method according to JIS K6301-1975, 5.2, using a rubber hardness meter (C-type, Kobunshi Keiki Co., Ltd.). This method is an indentation-type test employed to measure the hardness of rubber, in which a spring loaded (5,000 gf) indentor rod which narrows at a 35° angle to a smaller flat tip which is pressed through a hole not less than 10 mm in dia.) in a flat loading disc resting on the flat surface of a piece of the material which is larger than the loading disc and at least 6 mm thick. If the indentor intends the test material by 2.54 mm, i.e., projects 2.54 mm beyond the lower surface of the loading disc, it receives a hardness value of 0 in the test and if it does not indent the test material, i.e., the tip of the indentor is level with the lower surface of the loading disc, the test material receives a hardness value of 100 in the test.
Air-permeability was determined by the method according to JIS L1096, 6.27, using a Frazir type air-permeability tester. This test equipment employs a suction fan mounted on the lower end of a vertical cylinder having a partition with an air hole in it mounted in the middle of the cylinder and barometers fitted above and below the partition. The test material is clamped to the upper end of the cylinder to form a porous lid. The speed of the fan is adjusted to provided a standard pressure differential of (1.27 cm H 2 O) in the upper chamber. By use of a conversion table, the barometric pressure in the lower chamber gives the air permeability of the test material in terms of the air volume which passes through the tester (cm 3 /cm 2 /s). The test is conducted 5 times and the results averaged.
Porosity was determined by the following method. A quantity of methanol is placed in a graduated cylinder to a predetermined level. Then the sample is completely immersed in methanol and the increment in total volume is measured (n cc). Thereafter the sample is withdrawn from the cylinder and the decrease in the volume of methanol (m cc) is measured. The porosity may be calculated by the following equation:
Porosity=[m/(n+m)]×100
The pore size and pore sectional area were determined using electron-micrographs. These data represent average values.
EXAMPLE 3
Run Nos. 1 and 3 in Example 1 were repeated at varying temperatures and varying treating times. Increase in the hardness and air-permeability was determined in terms of the ratio of these values after the treatment relative to the corresponding values before the treatment. The results are shown in Table 3 below.
TABLE 3______________________________________ Run No. 1 3 Polymer conc., % 10 18Temp., Time, Air-perme- Air-perme-°C. min. Hardness ability Hardness ability______________________________________170 45 1.10 1.05 -- --180 45 1.16 1.62 1.01 1.42190 45 -- -- 1.05 1.89200 17 1.16 1.92 1.05 1.95240 3 1.20 1.95 1.06 2.03250 2 1.25 0.74 1.05 2.07260 1.5 -- -- 1.10 0.10______________________________________
EXAMPLE 4
Run Nos. 8 and 10 of Example 2 were repeated at varying temperatures and varying treating times. Increase in the hardness and air-permeability was determined in terms of the ratio of these values after the treatment relative to the corresponding values before the treatment.
The results are shown in Table 4 below.
TABLE 4______________________________________ Run No. 8 10 Polymer conc., % 10 18Temp., Time, Air-perme- Air-perme-°C. min. Hardness ability Hardness ability______________________________________170 45 1.14 1.28 1.05 1.18180 45 1.14 1.62 1.05 1.51190 10 1.17 2.03 1.07 1.77200 5 1.18 2.11 1.08 2.01210 5 1.21 2.20 1.10 2.27220 5 1.35 0 1.17 0______________________________________
As can be seen in Table 4, the air-permeability decreased to zero by the treatment at 220° C. for five minutes because of melting of the nylon 6.
Polishing test
Using polishing cloths obtained in Run Nos. 3 and 7 in Example 1, a high quality silicon wafer for use in the manufacture of integrated circuit substrates was polished. The machine used in the test was Model LM-600 sold by Techno Co., Ltd. The polishing conditions were as follows:
Abrasive powder: colloidal silica
Slurry concentration: Abrasive powder:H 2 O=1:19
Slurry pH: 10.3
Temperature: 23° C.
Slurry flow rate: 2.3 liter/min.
Coolant flow rate: 1 liter/min.
Lap wheel rotation: 100 rpm.
Work piece pressure: 400 g/cm 2
Dressing: every 30 minutes polishing
The change of polishing rate against time is shown in the accompanying drawing. In case of the polishing cloth produced by the method of this invention, the polishing rate remained constant over more than five hours and the work piece retained excellent flatness accuracy. No machining scratch was observed on the polished surface. On the other hand, the polishing cloth produced by the prior art method was clogged with abrasive powder only after 1 hour operation and the polishing rate gradually decreased thereafter. A number of machining scratches were observed on the polished surface.
While particular embodiments of the invention have been described, various modifications may be made without departing from the true spirit and the scope of the invention which is defined in the appended claims. | A method for manufacturing polishing cloths of the class to be used with abrasive powders on a lapping machine is disclosed. The method comprises the steps of impregnating a nonwoven fabric sheet with a solution of polyurethane elastomer, wet-coagulating the impregnated sheet, and heating the resulting microporous composite sheet at a temperature higher than the softening point of the polyurethane elastomer under an essentially uncompressed condition. | 3 |
BACKGROUND OF THE INVENTION
This invention relates to the treatment of pyrophoric materials such as sponge iron.
Sponge iron is a product utilized in the steel making industry as a basic source for the production of steel. Generally speaking, sponge iron is produced by exposing hematite (Fe 2 O 3 ) iron ore in comminuted form to a reducing gas environment at temperatures somewhat below blast furnace temperatures. The production of sponge iron is the subject of a large number of patents, including the following U.S. Pat. Nos. 2,243,110; 2,793,946; 2,807,535; 2,900,247; 2,915,379; 3,128,174; 3,136,623; 3,136,624; 3,136,625; 3,375,098; 3,423,201; 3,684,486; 3,765,872; 3,770,421; 3,779,741; 3,816,102; 3,827,879; 3,890,142; and, 3,904,397. The final sponge iron product of practically all of the processes disclosed in these patents is in a particulate or pellet form.
Typically, the components of sponge iron are metallic iron, iron oxide, gangue and possibly carbon. Metallic iron is iron which has been totally reduced by the reducing gas environment. Gangue is the term used in the industry to refer to all non-ferrous material, except carbon contained in the ore. Gangue may include silica, alumnia, lime, magnesia, phosphorus, sulfer and possibly other materials. A deposit of carbon on the outside surface of the sponge iron particulate will be described in greater detail hereinafter. In all of the iron ore reduction processes just referred to, freshly produced sponge iron as found in the final vessel in the process is at a very high temperature, typically at 1500° F. or even higher. The freshly produced sponge iron at high temperature must be moved from the final reactor to some type of storage location or be immediately utilized in a steel producing process. In the past, it was more typical that the freshly produced, high temperature sponge iron be used rather quickly in the production of steel. However, in the last few years, this situation has changed. There are more and more iron ore reducing plants being built in various parts of the world entirely removed from steel producing facilities. Therefore, it has become necessary that sponge iron be stored and even shipped long distances.
Freshly produced sponge iron at high temperatures is not a stable material. In fact, such sponge iron is pyrophoric and subject to degradation through oxidation by exposure to air or water.
Storage and shipment of sponge iron is not a new problem. But, the importance of pacifying the sponge iron has now reached great significance. Attempts to at least partially cool the sponge iron to a safe temperature are found in the prior art. It is known that freshly reduced sponge iron must be cooled down significantly. Some cooling has been incorporated into the reduction process. Generally, this initial cooling occurs while the just-reduced sponge iron is still in the reduction reactor. U.S. Pat. No. 3,904,397 of Celada and others discloses the utilization of cooled, spent reducing gas in such a cooling reactor. Other U.S. patents which refer generally to the utilization of a cooling step immediately after reduction include U.S. Pat. Nos. 3,765,872; 3,684,486; 3,136,625; 3,136,624; and, 3,136,623.
U.S. Pat. Nos. 3,816,102 of Celada et al. and 3,136,624 of Mader et al. disclose a process for coating or depositing a layer of carbon onto the hot sponge iron during the initial cooling of the just-reduced sponge iron. Carbon is deposited for the next step in the process, i.e., the electric furnace, which converts the iron to steel, and also the carbon present reacts with the remaining iron oxide to finish the reduction (FeO+C→CO+Fe). One of the results of the deposition of the carbon layer on the sponge iron is the formation of a protective shell against reoxidation of the hot sponge iron because iron combined with carbon such as Fe 3 C is supposedly less sensitive to oxygenation than the reduced metallic sponge iron. "Storage and Transportation of HYL DRI Pellets" presented by Ing. Raul G. Quintero, Hylsa, S.A. and Mr. G. E. McCombs, Pullman Swindell, Third Direct Reduction Congress, Instituto Latinoamericano del Fierro y el Acero, Caracas, Venezuela, July, 1977. U.S. Pat. No. 3,423,201 of Celada et al. discloses a method for cooling sponge iron having such a carbon layer deposited thereon. In Celada U.S. Pat. No. 3,423,201, a second cooling step is initiated when the temperature of the reduced ferrous material in the cooling reactor has dropped below the value at which cracking of reducing gas (and thus depositing of carbon on the sponge iron particulate) occurs. The Celada U.S. Pat. No. 3,423,201 states that the sponge iron is cooled to a temperature "near room temperature."
Basically, all of the just-discussed patents disclose the cooling of the sponge iron while still in a reactor. In order to cool the sponge iron in a reactor, it is necessary for the cooling gas to flow through the pile of sponge iron. Typically, the cooling gas takes the paths of least resistance and therefore is not equally distributed among all the sponge iron particulate. Further, the cooling gas serves to deposit fines in particular locations out of the flow paths of direct cooling gas flow so that hot spots of fines are formed. Such fines may also clog flow paths through the particulate and thus prevent cooling.
If the sponge iron is dumped from the reactor with certain portions at dangerously high temperatures, the likelihood of a significant portion of the entire batch or pile of sponge iron being eventually re-oxidized is high. This re-oxidation may not occur until the sponge iron is already on board a ship and in the middle of an ocean. The dangers to personnel of this type of fire, in addition to the economic loss, are considerable.
Another proposed solution to this problem has been suggested by the Midrex Corporation. Midrex Corporation has made public a chemical treating process sold under the trademark CHEMAIRE. The CHEMAIRE process is a combination of chemical treatment and air passivation to inhibit rusting and re-oxidation. "Direct From Midrex," Vol. 3, No. 2 brochure. Disadvantages of this type of system are several. First of all, the complete distribution of the chemical upon the particulate sponge iron is very unlikely. Secondly, the addition of the chemicals may or may not have any effect upon subsequent use of the sponge iron in the production of steel.
In summary, it was long ago recognized that sponge iron must be reduced below dangerous temperature levels in order to prevent re-oxidation. The main or most common method that has been used as disclosed in U.S. patents has been to cool the sponge iron while in the final reactor. Industrial practice has proven that cooling of the sponge iron in the final reactor has not been totally satisfactory. One possible solution to the problem as shown in the prior patents has been to dispose a layer of carbon upon the sponge iron during the cooling process. However, it has been found in practice that the carbon layer does not eliminate the problem since the core of the particulate sponge iron pellets may remain at too high a temperature and eventually re-oxidize upon exposure to air or water. Finally, a chemical treatment has been proposed, one disadvantage to such treatment being a likelihood of inadequate distribution of the chemical upon the particulate sponge iron.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a new and improved method for reducing the temperature of freshly-reduced sponge iron to a safe level for storage and shipment. In summary, the method of treating sponge iron disclosed here includes the steps of transferring freshly-reduced sponge iron in particulate form to a separator vessel and passing a cooling gas stream through the sponge iron in order to initially cool and fluidize lighter or smaller particles and fines. The lighter particles and fines are then transferred by fluidization so that only the larger or heavier, more solid sponge iron particles remain. The sponge iron remaining is then transferred by vibratory conveyor towards a storage area; and, the cooling gas is applied to the remaining sponge iron simultaneously with conveyance by vibratory motion toward a storage area in order to reduce the average temperature of the sponge iron to a safe level.
This summary of the invention is not intended to fully and accurately describe any or all of the patentable features of this invention. The features for which patent protection has been sought are set forth in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic flow chart of a method for reducing the temperature of freshly reduced sponge iron to a safe level of this invention;
FIG. 2 is a side, schematic view of the vessel containing the apparatus for simultaneously conveying and cooling certain sponge iron particulate;
FIG. 3 is a schematic, sectional view of a portion of the apparatus of FIG. 2; and
FIG. 4 is a schematic flow chart view of another embodiment of the method for reducing the temperature of recently-produced sponge iron to a safe level.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, FIGS. 1-3 illustrate a method generally designated as M-1 for reducing the temperature of freshly-reduced sponge iron to a safe level for storage and shipment. A second, equally important method M-2 for reducing the temperature of recently-produced sponge iron is illustrated in FIG. 4.
The method M-1 is carried out by the apparatus generally designated by the number A-1 in FIG. 1. The apparatus A-1 includes compressor 10 which is connected to inlet gas feed line 11 at its inlet and to outlet, compressed gas line 12 at its outlet. A cooling coil 14 is mounted in the compressed gas outlet line 12 for cooling the compressed gas prior to introduction through connecting line 15 to fines bin 16. The compressed gas line 12 is also connected by line 17 to a separator vessel or reactor 18.
The separator reactor 18 includes a main vessel housing 18a having a cylindrical riser 18b extending upwardly therefrom. The riser 18b is connected to conduit 19 which empties into a cyclone separator 20.
The cyclone separator 20 can be one of a number of commercially manufactured units, followed by a secondary dust removal system such as a bag house, electrostatic precipitator, or other commercially available equipment. The gas and fines in the cyclone separator are cooled by any type of surrounding water jacket structure such as shown schematically at 21. The filtering apparatus 20 is connected by collection conduit 22 to the fines bin 16.
A horizontal vibratory conveyor apparatus 25 is mounted in the bottom of the reactor vessel housing 18a for conveying sponge iron particulate from the vessel housing 18a to cooling reactor 26.
The cooling reactor 26 is shown schematically in FIG. 1 and in somewhat more detail, but also schematically, in FIGS. 2 and 3. A generally cylindrical vessel 26a mounts a vibratory spiralling conveyor platform 27 having a central support tube 28. The entire spiralling conveyor is permanently attached to the central support tube 28 and terminates in a horizontal entry conveyor portion 27a at the bottom thereof and in a horizontal exit conveyor portion 27b at the top thereof. The spiralling conveyor 27 and support tube 28 are both mounted for vibratory motion by a vibration imparting mechanism illustrated schematically and designated as 30. One such vibratory spiralling conveyor 27 having a central support tube 28 in vibratory mechanism 30 is available from Carrier Corporation.
Referring to FIG. 3, the spiralling conveyor 27 is formed by a spiralling platform 31 which is welded or otherwise connected to the central support tube or shaft 28. A side member or edge 32 is attached to the spiralling platform 31 and a second, perforated spiralling plate or deck 33 is attached to the side member 32 and extends parallel to the platform 31 for vibration therewith. The spiralling platform or deck 33 is also attached by suitable braces (not shown) to the central support tube 28. A plurality of nozzles 34 are mounted on the spiralling support platform 31 and are directed upwardly to spray fluid, liquid or gas upwardly through the perforated deck 33 into the sponge iron mass S supported on the plate 33. Openings 35 and 36 are positioned in the central support tube 28 above and below the perforated supporting deck 33 for passing a cooling gas both above and below the deck 33. The cooling gas is then circulated outwardly of the spiralling conveyor 27 and upwardly through the vessel top perforated support barrier 36a to reactor outlet 26b.
The gas outlet conduit 26b for cooling reactor vessel 26 is attached to a wet scrubber 40. The wet scrubber 40 is connected to conduit 41 which extends back into connection with inlet line 11.
The central support tube 28 of the cooling reactor 26 is connected to conduit 42 which provides for the transfer of cooling gas from separator 20 into the central support tube 28 for flow through the vibrating, spiralling deck 33 and the sponge iron positioned thereon.
A solids collection conduit 43 is attached to the bottom of the central support tube 28 and another solids collection conduit 44 is attached to the bottom of the wet scrubber 40. The conduits 43 and 44 are adjoined to a common solids collection line 45 which extends to a suitable collection point for collecting dust, fines and other miscellaneous particulate which may collect in either apparatus.
In practicing the method M-1 of this invention, recently-reduced sponge iron S is delivered into separator vessel housing 18a through horizontal conveyor 50 from reactor vessel 51, which is actually part of a sponge iron reducing system.
As the sponge iron enters the vessel housing 18a from vibrating conveyor 50, it tends to fall downwardly due to gravity. Cooling gas entering through line 17 and gas plenum 17a mounted about separator vessel housing 18a flows upwardly to fluidize the falling sponge iron particulate. Fluidization of the sponge iron particulate by the cooled gas serves both to reduce the temperature of the particulate and to separate and remove smaller or lighter particles and fines of the sponge iron for fluidized transfer upwardly through tubular riser 18b. The remaining sponge iron particulate, which is principally heavier or larger, solid sponge iron particles or pellets, flows downwardly and into horizontal conveyor 25.
The separated fines flow upwardly through riser tube 18b, through conduit 19 into the separator 20 wherein the fines are separated from the gas, the cleaned cooling gas flowing through conduit 42 to the central support tube 28 of cooling reactor 26 and the separated or filtered fines and smaller particles being transferred through conduit 22 to the fines bin 16. The fines and smaller particles may be transferred from the fines bin 16 under gas pressure from the line 15 to a briquetting plant or other destination.
The remaining sponge iron travels along conveyor 25 and enters the spiral vibratory conveyor 27 at 27a and travels upwardly around tube 28 toward outlet 27b.
The clean cooling gas enters the central support tube 28 from conduit 42 and flows downwardly therethrough and outwardly of the tube 28 through openings such as 35 and 36 above and below the vibrating, perforated support deck 33. The cooling gas passes over the vibrating solid sponge iron particles and cools the sponge iron particles as they are transferred upwardly along the spiral path to the exit 27. The temperature of the cooling gas flowing radially outwardly through openings such as 35 and 36 is sufficiently low, and the exposure of the solid particulate as it is vibrated is sufficiently great, that the sponge iron particulate is reduced to a safe temperature prior to exit at vibratory conveyor exit point 27b. The cooling gas flows outwardly through the vibrating remaining sponge iron particulate and into the interior 26a of the cooling vessel 26 and upwardly through the perforated barrier 36a into outlet conduit 26b. The cooling gas, which will undoubtedly contain some more fines and perhaps dust, is then cleaned in the wet scrubber 40 before flowing through conduit 41 back to entrance line or conduit 11. The sponge iron coming out of the cooling reactor 26 at conveyor exit 27b is now at a sufficiently low temperature that it will not re-oxidize upon contact with air or water and is thus safe for shipment and storage.
A further feature of this invention is the utilization of the nozzles 34 to provide a cooling liquid mist to the vibrating sponge iron particles. It is contemplated that this cooling mist will only be applied during the latter or upper spirals after the temperature of the vibrating sponge iron particulate has already been sufficiently reduced. Basically, the addition of the mist is to finally prepare the vibrating, cooled sponge iron particulate for exposure to the environment at the exit conveyor 27b.
The method M-2 of reducing the temperature of recently-produced sponge iron is accomplished by apparatus A-2 of FIG. 4. Basically, the same equipment is utilized in apparatus A-2 as in apparatus A-1. Therefore, wherever possible, the same number or letter designations will be utilized. The method M-2 for reducing the temperature of recently-produced sponge iron is provided by transferring sponge iron S from reactor bin 51 through vibratory conveyor 50 to the separator or fluidizing vessel 18. The fluidizing vessel 18 includes a central fluidizing housing 18a having mounted thereon a riser tube 18b. Cooling gas enters the apparatus A-2 through entry line 60 and joins recycling gas from line 61 for cooling through cooling coil 62. The cooled gas is then compressed in compressor 10 for delivery to compressed cooling gas line 63 connected to the central support tube 28 of the cooling reactor 26. The compressed, cooled gas flows outwardly through the vibrating spiralled conveyor 26 in the same manner as has been described with respect to the method M-1. The finally cooled sponge iron exits through conveyor 64 which is attached to the top exit spiralled conveyor portion 27b. The cooling gas, however, is not at this point collected and filtered for reuse as in the method M-1, but rather, the cooling gas of the method M-2 exits through line 65 which is connected to vessel plenum chamber 66. The vessel plenum chamber 66 is an annular chamber that surrounds the fluidizing vessel housing 18a, which is provided with suitable openings such as 66a illustrated schematically in FIG. 4, for allowing gas entry into the vessel 18a for fluidizing the sponge iron coming off of conveyor 50. The fluidizing gas again separates fines and lighter sponge iron particles for transfer through riser conduit 18b into separators 20. The separators 20 are illustrated as being cyclone separators and again are water cooled by water jacketing at 21 for cooling the fines and lighter particles prior to collection in horizontal vibratory feeder 22 and subsequent depositing in the fines bin 16. The cooling gas cleaned of fines and lighter particles enters transfer conduit 67 for flow to bag house 68 and then flow into return line 61. The further filtered particles exit through lines 68a and 68b of the bag house and also enter the fines bin 16 through line 69. The recycled gas coming out of the bag house enters line 61 and is joined by makeup line 60 prior to entry into cooling coil 62. The fines again are sent to a briquetting process or other destination as desired.
The larger, more solid particulate flows downwardly through the separator housing 18a and into horizontal vibrating conveyor 25 for transfer to the spiralling or helical vibratory conveyor 27. As the more solid particles travel upwardly, cooling gas flowing through central support tube or downcomer 28 cools the vibrated particulate in the same manner as has been described with respect to FIGS. 2 and 3. In this manner, the temperature of the sponge iron leaving through the top spiral conveyor end portion 27b is reduced to a safe level thus pacifying the material for exposure to air or other ambient oxidizers.
In the embodiments of both processes M-1 and M-2, the cooling gas is an inert gas in that it has no oxidizing ingredients therein to re-oxidize with the recently-produced sponge iron. The inert gas may be any suitable reducing gas including a reducing tail gas taken from the reduction process itself; or, the cooling gas may be truly inert and thus incapable of oxidizing or reducing the particulate being cooled and separated.
The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes and alterations may be made without departing from the spirit of the invention. | A method of reducing the temperature of sponge iron to a safe level for storage and shipment including the steps of transferring freshly prepared sponge iron in particulate form to a separator vessel, such sponge iron being at dangerously high temperatures rendering it susceptible to oxidation; passing a cooling gas stream through the sponge iron in order to initially cool and fluidize the sponge iron and transfer smaller particles and fines away from the larger, more solid sponge iron particulate; conveying by vibration the remaining sponge iron towards a storage area and applying the cooling gas to the remaining sponge iron as it is conveyed towards storage in order to reduce the average temperature of the sponge iron to a safe level. | 2 |
CROSS-REFERENCES TO RELATED APPLICATION
The present application claims priority under 35 U.S.C. §119(a) to Korean application number 10-2012-0057328, filed on May 30, 2012, in the Korean Intellectual Property Office, which is incorporated herein by reference in its entirety as set forth in full.
BACKGROUND
1. Technical Field
The present invention relates to a semiconductor circuit, and more particularly, to a repair control circuit and a semiconductor integrated circuit using the same.
2. Related Art
A semiconductor integrated circuit 1 in the related art includes, as illustrated in FIG. 1 , a plurality of unit memory blocks (hereinafter referred to as “MAT”), each of which is provided with a plurality of memory cells, a plurality of bit line sense amplifiers BLSA, a word line driver 10 , and a repair control circuit 20 .
The repair control circuit 20 includes, as illustrated in FIG. 2 , a repair address generation unit 21 , a comparison unit 22 , and a repair unit 23 .
The repair address generation unit 21 generates repair column addresses CRADDR<0:n> in response to a plurality of MAT selection signals MATSEL<0:n> and a bank active signal ActiveBK.
The comparison unit 22 activates a repair signal REP if the column addresses CADDR<0:n> and the repair column addresses CRADDR<0:n> coincide with each other.
The repair unit 23 activates a repair column selection signal RYi<c> if the repair signal REP is activated.
As a method to reduce time for testing in the related art, a plurality of word lines are simultaneously activated to reduce column access time tRCD after a read command and precharge time tRTP after a column access.
Referring to FIG. 1 , a method for simultaneously activating a plurality of word lines WL<a> and WL<b> has been used to reduce time for testing.
However, this method is unable to be used after cells in which defects have occurred are repaired, and the reason is as follows.
If the plurality of word lines LW<a> and WL<b> are activated after the repair is performed, corresponding MAT selection signals MATSEL<0:n> are generated.
It is then required that a repair column selection signal RYi that corresponds to one repair column address CRADDR<0:n> is generated according to one MAT selection signal MATSEL<i>.
However, since the plurality of MAT selection signals, for example, two MAT selection signals MATSEL<i, j>, are simultaneously generated, the column selection signals Yi<a, b> that correspond to different column addresses are simultaneously activated, and this causes a column repair error to occur.
A wrong repair column selection signal RYi is activated instead of a normal column selection signal, and data which is different from the data that is required in a test operation is output that may cause a fatal problem.
Accordingly, the test method in the related art through simultaneous enabling of a plurality of word lines is unable to be used after the repair, and thus is not possible to reduce test time.
SUMMARY
An embodiment of the present invention relates to a repair control circuit and a semiconductor integrated circuit using the same, which can reduce test time.
In an embodiment of the present invention, a repair control circuit includes: a selection signal generation unit configured to generate selection signals in response to surplus addresses, a selection unit configured to selectively output a plurality of memory block selection signals for selecting one or more of a plurality of memory blocks connected to word lines in response to the selection signals, and a repair address generation unit configured to generate repair addresses in response to the selection signals and outputs of the selection unit.
In an embodiment of the present invention, a semiconductor integrated circuit includes: a plurality of memory blocks in which a plurality of word lines are arranged, a plurality of word line drivers driving one or more of the plurality of word lines in response to a plurality of memory block selection signals, and a repair control circuit determining whether to perform a repair through comparison of repair addresses generated in response to surplus addresses and the plurality of memory block selection signals with external addresses.
According to the embodiments of the present invention, it is possible to perform a test in which a plurality of word lines are simultaneously activated even after the repair of cells in which defects have occurred is performed, and thus is possible to reduce test time.
BRIEF DESCRIPTION OF THE DRAWINGS
Features, aspects, and embodiments are described in conjunction with the attached drawings, in which:
FIG. 1 is a block diagram illustrating the configuration of a semiconductor integrated circuit in the related art,
FIG. 2 is a block diagram illustrating the internal configuration of a repair control circuit in FIG. 1 ,
FIG. 3 is a block diagram illustrating the configuration of a semiconductor integrated circuit according to an embodiment of the present invention,
FIG. 4 is a block diagram illustrating the internal configuration of a repair control circuit in FIG. 3 ,
FIG. 5 is a circuit diagram illustrating the internal configuration of a selection signal generation unit in FIG. 4 ,
FIG. 6 is a circuit diagram illustrating the internal configuration of a selection unit in FIG. 4 ,
FIG. 7 is a circuit diagram illustrating the internal configuration of a repair address generation unit in FIG. 4 ,
FIG. 8 is a circuit diagram illustrating the internal configuration of a repair address generation unit in FIG. 4 , and
FIG. 9 is a timing diagram illustrating the operation of a repair control circuit according to an embodiment of the present invention.
DETAILED DESCRIPTION
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings through various embodiments.
FIG. 3 is a block diagram illustrating the configuration of a semiconductor integrated circuit 100 according to an embodiment of the present invention.
As shown in FIG. 3 , the semiconductor integrated circuit 100 according to an embodiment of the present invention includes a plurality of unit memory blocks (hereinafter referred to as “MAT”), each of which is provided with a plurality of memory cells, a plurality of bit line sense amplifiers BLSA, a plurality of word line drivers 10 , and a plurality of repair control circuits 200 .
The plurality of unit memory blocks may be divided into a first block 110 and a second block 120 .
The semiconductor integrated circuit 100 according to an embodiment of the present invention makes it possible to perform a test using a method in which a plurality of word lines WL<a> and WL<b> are simultaneously activated even after the repair of cells in which defects have occurred is performed.
FIG. 4 is a block diagram illustrating the internal configuration of a repair control circuit 200 in FIG. 3 .
As illustrated in FIG. 4 , a repair control circuit 200 includes a selection signal generation unit 210 , a repair address generation unit 230 , a comparison unit 240 , and a repair unit 250 .
The selection signal generation unit 210 is configured to generate selection signals SIOSEL_L and SIOSEL_H in response to a bank active signal ActiveBK and a column address, such as a surplus column address, CA<12>.
The selection unit 220 is configured to select one of a plurality of memory block selection signals (hereinafter referred to as “a plurality of MAT selection signals”) MATSEL<0:n/2-1> and MATSEL<n/2:n> in response to the selection signals SIOSEL_L and SIOSEL_H, and to output the selected signal as a final MAT selection signal MATINF<0:n>.
The MAT of the first block 110 may be selected according to MATSEL<0:n/2-1>, and the MAT of the second block 120 may be selected according to MATSEL<n/2:n>.
The repair address generation unit 230 is configured to generate repair column addresses CRADDR<0:n> in response to the final MAT selection signal MATINF<0:n>, the bank active signal ActiveBK, and the selection signals SIOSEL_L and SIOSEL_H.
The repair address generation unit 230 may be divided into first and second blocks 231 and 232 .
The comparison unit 240 is configured to activate a repair signal REP if the repair column addresses CRADDR<0:n> coincide with column addresses CADDR<0:n>.
The repair unit 250 is configured to activate a repair column selection signal RYi<c> if the repair signal REP is activated.
FIG. 5 is a circuit diagram illustrating the internal configuration of a selection signal generation unit 210 in FIG. 4 .
As illustrated in FIG. 5 , the selection signal generation unit 210 includes a plurality of inverters and a plurality of NAND gates.
The selection signal generation unit 210 performs logical products of the bank active signal ActiveBK and the surplus column address CA<12> to generate the selection signal SIOSEL_H, and performs logical products of the bank active signal ActiveBK and an inverted surplus column address CA<12> to generate the selection signal SIOSEL_L.
FIG. 6 is a circuit diagram illustrating the internal configuration of a selection unit 220 in FIG. 4 .
As illustrated in FIG. 6 , the selection unit 220 includes a plurality of NAND gates and a plurality of inverters.
The selection unit 220 performs logical products of the selection signal SIOSEL_L and the plurality of MAT selection signal MATSEL<0:n/2-1> to output the final MAT selection signal MATINF<0:n/2-1>, and performs logical products of the selection signal SIOSEL_H and the plurality of MAT selection signal MATSEL<n/2:n> to output the final MAT selection signal MATINF<n/2:n>.
FIG. 7 is a circuit diagram illustrating the internal configuration of a repair address generation unit 231 in FIG. 4 .
As illustrated in FIG. 7 , the first block 231 of the repair address generation unit 230 includes a plurality of NOR gates, a plurality of NAND gates, a plurality of inverters, and a plurality of delay elements DLY 1 to DLY 5 .
The first block 231 generates repair address control signals ResetRA and SetRA using pulse signals generated with a predetermined time difference in response to the selection signals SIOSEL_L and SIOSEL_H and the bank active signal ActiveBK.
The shift of the repair address control signals ResetRA and SetRA is determined by the selection signals SIOSEL_L and SIOSEL_H and the bank active signal ActiveBK.
The shift timing of the repair address control signals ResetRA and SetRA is determined by delay elements DLY 1 to DLY 3 .
The pulse widths of the repair address control signals ResetRA and SetRA are determined by delay elements DLY 4 and DLY 5 .
FIG. 8 is a circuit diagram illustrating the internal configuration of a repair address generation unit 232 in FIG. 4 .
As illustrated in FIG. 8 , the second block 232 of the repair address generation unit 230 includes a plurality of inverters, a plurality of transistors, and a plurality of fuses.
The second block 232 generates repair column addresses CRADDR<0:n> depending on whether the fuse corresponding to the final MAT selection signal MATINF<0:n> has been cut during a low-level period of the repair address control signal ResetRA.
FIG. 9 is a timing diagram illustrating the operation of a repair control circuit 200 according to an embodiment of the present invention.
Referring to FIG. 9 , the repair control operation according to the present invention will be described.
Two word lines are simultaneously activated during an active period of the bank active signal ActiveBK for a test operation.
The selection signal SIOSEL_L is activated using the surplus column address CA<12> of a low level in an active state of the bank active signal ActiveBK (see FIG. 5 ).
MATSEL<0:n/2-1>, which is one of the plurality of MAT selection signals MATSEL<0:n/2-1> and MATSEL<n/2:n>, is selected using the activated selection signal SIOSEL_L, and is output as the final MAT selection signal MATINF<0:n> (see FIG. 6 ).
On the other hand, the repair address control signals ResetRA and SetRA are generated during the active period of the selection signal SIOSEL_L (see FIG. 7 ).
The repair column addresses CRADDR<0:n> are generated depending on whether the fuse, which corresponds to the final MAT selection signal MATINF<0:n> generated by selecting MATSEL<0:n/2-1>, has been cut, and the repair address control signals ResetRA and SetRA (see FIG. 8 ).
If the repair column addresses CRADDR<0:n> coincide with the column addresses CADDR<0:n>, the repair signal REF is activated, and thus the repair column selection signal RYi<c> is activated to perform the repair operation (see FIG. 4 ).
Then, the selection signal SIOSEL_H is activated via shifting of the surplus column address CA<12> to a high level (see FIG. 5 ).
MATSEL<0:n/n>, which is one of the plurality of MAT selection signals MATSEL<0:n/2-1> and MATSEL<n/2:n>, is selected using the activated selection signal SIOSEL_H, and is output as the final MAT selection signal MATINF<0:n> (see FIG. 6 ).
On the other hand, the repair address control signals ResetRA and SetRA are generated during the active period of the selection signal SIOSEL_H (see FIG. 7 ).
The repair column addresses CRADDR<0:n> are generated depending on whether the fuse, which corresponds to the final MAT selection signal MATINF<0:n> generated by selecting MATSEL<n/2:n>, has been cut, and the repair address control signals ResetRA and SetRA (see FIG. 8 ).
If the repair column addresses CRADDR<0:n> coincide with the column addresses CADDR<0:n>, the repair signal REF is activated, and thus the repair column selection signal RYi<c> is activated to perform the repair operation (see FIG. 4 ).
As described above, according to an embodiment of the present invention, the MAT selection signals are sequentially generated using the surplus column address CA<12>, and thus normal repair column addresses CRADDR<0:n> that correspond to the MAT selection signals, respectively, are generated. Accordingly, it is possible to perform the test in which the plurality of word lines WL<a> and WL<b> are simultaneously activated even after the repair of cells in which defects have occurred is performed.
While certain embodiments have been described above, it will be understood to those skilled in the art that the embodiments described are by way of example only. Accordingly, the is semiconductor memory apparatus described herein should not be limited based on the described embodiments. Rather, the semiconductor memory apparatus described herein should only be limited in light of the claims that follow when taken in conjunction with the above description and accompanying drawings. | A repair control circuit and a semiconductor integrated circuit using the same, which can reduce test time, are provided. The semiconductor integrated circuit includes a plurality of memory blocks in which a plurality of word lines are arranged, a plurality of word line drivers driving one or more of the plurality of word lines in response to a plurality of memory block selection signals, and a repair control circuit determining whether to perform a repair through comparison of repair addresses generated in response to surplus addresses and the plurality of memory block selection signals with external addresses. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a multiprocessor computer system, comprising n synchronously controlled parallel-operating computer modules, each of which is localized in its own fault isolation area, Each computer module comprises a processor module; a data channel connected to a data connection of the processor module; a reducing encoder connected to the data channel in order to form a code symbol from a data word received so that the relevant encoders forms, on the basis of a data word comprising k data symbols, a code word consisting of k+1≦n<3k code symbols of a code incorporating a simultaneous correction capability in at least two code symbols; a memory module comprising a first data input which is connected to a first data output of the associated reducing encoder, and to a second data output; and a data word reconstruction module which is connected via an interconnection network, to the relevant second data outputs of the memory modules of the various computer modules in order to receive a relevant code symbol of a code word from each computer module in order to reconstruct a data word therefrom, the data word reconstruction module comprising a third data output which is connected to said data connection and to said data channel, said data channel also comprising a second data connection for external data input/output.
2. Description of the Prior Art
Such a computer system is disclosed in the previous U.S. Pat. No. 4,512,020 issued Apr. 16, 1985, assigned to the assignee of the present application. For such a multiprocessor computer system a comparatively small total memory capacity suffices for a comparatively high processor capacity, for example in comparison with a total triplication of processor and memory capacity distributed between a corresponding number of faults isolation areas. In accordance with the previous Patent Application, similarly to when using the total triplication, the total circuit of one such fault isolation area may exhibit an arbitrary data error without the operation of the multiprocessor computer system as a whole being impeded. The computer system in accordance with the previous Patent Application has several modes of operation. In one of these modes an arbitrary symbol error can be corrected (provided that it is known which symbol is incorrect) plus one single bit error. In another mode, two arbitrary one-bit errors can be corrected. Several codes which are capable of correcting several bit errors are known per se, for example, the "Fire" codes; the error location while using the last-mentioned codes may be completely arbitrary.
The error correction capability according to said Patent Application is an extension of that disclosed in the previous U.S. Pat. No. 4,402,045 assigned to the assignee of the present application. The latter offers several redundancy levels which can be used to implement the data input/output. A high degree of redundancy with ample correction of errors is achieved by multiplying the connections for data input/output in the same way as the multiplication of the computer modules in the computer system itself. The relevant peripheral apparatus may then be of a multiple construction. On the other hand, the peripheral apparatus may also be singular without redundancy. Intermediate redundancy levels can also be implemented. These different redundancy levels can also be incorporated in the multiprocessor computer system disclosed in said U.S. Patent Application Ser. No. 416,992. In many cases it is necessary to implement an input/output memory, for example for buffering and reformatting the data. The memory capacity is then usually comparatively small when considered as cost factor in comparison with the other cost factors which would occur if a code word comprising n symbols with associated data reconstruction sectors, data interconnections and the like were to be formed. This is also applicable if, in addition to the input/output memory, an input/output processor module and possibly further components associated therewith are required.
Consequently, the input/output data is received in non-coded form (as viewed in relation to the error correction code); therefore, it is an object of the invention to ensure that the input/output data may not be processed in such a way during the input/output process that a bit error occurring could be converted in the reducing encoder into a multibit symbol error. Such a multibit symbol error might be correctable in many cases, but should another bit error occur in the same code word, the error correction capability of the code might easily be insufficient. The object in accordance with the invention is achieved in that each computer module also comprises a second data channel which is connected in series with said second data connection and which comprises a third data connection to the environment; an input/output memory module which is connected, at least when the generator matrix (G i ) of the associated reducing encoder maps a data bit on more than one code bit, to the second data channel by way of a second, non-reducing encoder and a third data input and a decoder which is associated with the second encoder, the following relations existing between the generator matrix (G i ) of a reducing encoder, at least in as far as this encoder maps a data bit on more than one code bit, the generator matrix [G i ] of the second encoder, and the generator matrix [G i * -1 ] of the decoder:
[G]·[G.sub.i *.sup.-1 ]=[I], the identity matrix;
[F]=[G.sub.i ]·[G.sub.1 *.sup.-1 ],
in which each column of [F], written as consisting of bits, contains at the most one "1" and for the remainder exclusively "zeros", each row of [F] containing at least one "1", so that in the relevant computer module a bit of a data word encoded in the input/output memory is mapped on at the most one bit of the code symbol which can be formed from the data word. In as far as a reducing encoder maps a data bit on "zero" code bits, an error in the relevant data bits will not be passed on to the relevant memory module. In as far as the mapping is performed on one code bit in the reducing encoder, a bit error in the input/output memory will be passed on as only a single bit error in the relevant memory module, even when no special steps are taken in the second encoder/decoder. In both cases the generator matrix of the second encoder may have the properties of an identity matrix (multipled or not by a transposition matrix which modifies the sequence of the bits) for the relevant data bit. In as far as the reducing encoder maps a data bit on more than one code bit, the relevant generator matrices must satisfy more severe requirements.
Preferably, the error correction capability of the code allows for at least one arbitrary error vector in at least one code symbol. In conjunction with the "erasure" mode of said U.S. Pat. No. 4,512,020 the idea of the invention offers a very attractive implementation.
Preferably, a data word reconstruction module has at least two selectively activatable modes of operation each with a different correction capability. The flexibility in dealing with different error causes is thus further enhanced.
Preferably, each row of the matrix [F] contains exactly one "1". In that case many errors of the input/output memory do not become manifest in the relevant memory module of the main memory and the error probability in the latter memory is minimized.
Preferably, each column of the matrix [F] contains exactly one "1". All errors of the input/output memory then become manifest in the relevant memory module of the main memory so that the input/output memory can be readily tested.
The invention also relates to a computer module for use in a multiprocessor computer system of the kind described in which the reducing encoder maps at least one data bit on at least two code bits, the combination formed by the decoder and the reducing encoder mapping each bit from the input/output memory on at the most one bit in the memory module. Using such a computer module, an error-tolerant multiprocessor computer system can be readily formed.
BRIEF DESCRIPTION OF THE FIGURES
The invention will be described in detail hereinafter with reference to some Figures.
FIG. 1 is a block diagram of a multiprocessor computer system in accordance with the invention.
FIG. 2 shows an example of a generator matrix of an error correction code for use in a system as shown in FIG. 1.
FIG. 3 shows the separate generator matrices of the reducing encoders, second encoders, and decoders shown in FIG. 2 for a first case;
FIG. 4 shows these separate generator matrices for a second case;
FIGS. 5 and 6 illustrate a further possibility for the matrix [F] and the consequences thereof for the generator matrices.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a block diagram of a multiprocessor computer system in accordance with the invention. Part of this Figure corresponds to the diagram of FIG. 3 of the previously U.S. Pat. No. 4,402,045 which is incorporated herein by way of reference. The multiprocessor computer comprises four synchronously controlled computer modules which all execute the same instructions. The synchronization mechanism (not shown) may consist of a system of four mutually synchronized clocks, but has been omitted for the sake of simplicity. The first computer module comprises a processor module 20, for example a suitable microprocessor. The address output thereof is connected to the address input of the local memory 30. The data can be applied to the data input of the local memory module 30 via a data channel 70 and a reducing encoder 40. The sixteen-bit data word is thus converted into an eight-bit code symbol. When the memory 30 is read, the code symbol is applied to a register 50 which has a width of 32 bits. Each sub-computer comprises such a register and all registers are filled with all four 8-bit code symbols. The output of the code word register 50 is connected to the data word reconstruction module 60. This module is capable of correcting an arbitrary incorrect code symbol (arbitrary location and also arbitrary error) so that one of the (four) sub-computers can fail in an arbitrary manner (unless the failure itself adversely affects the operation of the other sub-computers). As has already been stated, in some cases bits in different code symbols can also be corrected (2 bits, each of which is situated in a different code symbol, or 1 code symbol in the erasure mode, which code symbol is then ignored, plus 1 bit in a further code symbol). The above possibilities are applicable to a code based on four-bit symbols; each data and each code word actually consists of two halves, each half thus comprising two and four symbols, respectively. The encoding circuits are simple due to the use of comparatively short symbols. In the extreme left computer module the number of bits transported per word (data word or code word) via the relevant line is indicated. For a different choice of the numbers and lengths of the symbols, corresponding situations occur, provided that each symbol contains at least two bits.
The computer also comprises a data input/output system. Again only the associated part of the input/output system for one computer module will be described. There is provided a connection element 80. This is, for example, a bi-directional tristate buffer which is activated by the processor 20 or an associated control element via control lines (not shown). The connection element may also be completely passive, for example a bus connection; however, all connected elements (data transmitters/receivers) are then selectively activated. A data channel 90 which has a width of 16 bits and which is terminated by a second connection element 140. Also provided is an input/output processor 100, which may be dispensed with in given cases. An address output of the processor 100 is connected to the address input of the memory 110. In the absence of a processor, this memory is, for example, a first-in-first-out (FIFO) buffer which requires no external addressing. Cases in which a processor is required occur, for example, when data is to be formatted for storage in a magnetic disc memory; in addition to the buffer function of the memory 110, also the addition or removal of synchronization information, indication information and void spacing information is then necessary. Such a magnetic disc memory will be connected in one of the ways disclosed in said U.S. Pat. No. 4,512,020. The same is applicable to other input/output situations. In a set-up involving little redundancy, only one of the connection elements 140, 142, 144, 146 is active for transmission, while for receiving all connection elements are active in parallel for all receiving the same information. In a set-up involving a high redundancy, the relevant peripheral apparatus also has a multiple construction (for example, an n-fold construction) and similar reducing encoders are connected, in the same manner as elements 40-46, to the connection elements 140-146 for transmission and, for reception, each of the connection elements 140-146 comprises its own data word reconstruction module which receives all code symbols of the code word. A large variety of possibilities exists between these two extremes.
The different correction facilities previously described relate to different types of failure of the system. When a processor, for example the processor module 20 or the I/O processor module 100, is faulty, such a fault is usually permanent (has a duration amounting to a large number of successive processor cycles) and causes many multibit errors in the code symbol formed (for example by the reducing encoder 40) on the basis of the incorrect data word. There is no remedy against this situation other than the use of the possibilities offered by the symbol correction code in the data word reconstruction module 60. This is because the error in the data word often involves several bits.
The second category of errors is caused by the memory modules. Part of these errors is permanent and involves several bits in a data word (module 140) or in a code symbol (module 30), for example because the address decoder is faulty. Single-bit errors occur much more frequently. These errors often appear as temporary failures. On the one hand such an error may be temporary, for example in that a data bit is disturbed by an alpha radiation particle which induces charge leakage. On the other hand a data bit error may be permanent (for example the bit valve may be continuously zero) but it does not affect other data bits and, because the same address is addressed only at intervals, it also appears as a temporary single bit error. It may also be, for example, when the memory is bit-organized, that one of the integrated circuits outputs only "zeros"; this concerns, for example, a semi-permanent error in the j th bit position of the relevant word/symbol. It is important that such a single bit error, occurring in the memory module 110, does not become manifest as a multibit error upon presentation, via the reducing encoder 40 and possibly after intermediate storage in the memory 30, to the data word reconstruction module 60. In combination with a symbol error in another computer module, such a multibit error would usually be incorrectable. Thus, a single bit error in the module 110 may cause at the most a 1-bit error on the output of the encoder 40. Moreover, the encoder 120 may not introduce further redundancy.
The code is thus defined on symbols comprising 4 bits each, so that only half a data word comprising 2×4=8 bits and one half a code word comprising 4×4=16 bits need be considered. It follows directly therefrom that the generator matrices (Go . . . G3) of the reducing encoders 40 . . . 46 are always 4×8 matrices and that the generator matrices [G o * -1 . . . G 3 * -1 ] of the relevant decoders 130 . . . 136 are always 8×8 matrices. No information may be modified or lost during the encoding in the second encoders 120-126 and the decoding in the decorders 130-136. It follows therefrom that the generator matrices [G o * . . . G 3 *] must not be singular and that the product
[G.sub.0 *.sup.-1 ]·[G.sub.0 *]=[I]
is equal to an identity matrix [I] (and similarly in the other modules).
We also define:
[F]=[G.sub.i ]·[G.sub.i *.sup.-l
so that [F] is the generator matrix for forming the associated code symbol from the content of the memory module (110 . . . 116) in accordance with:
a=[F]·b
It is known that the matrix [F] is found as follows. When a table is known with all feasible data words (vectors) b, and each associated code symbol a, the base vectors b which contain only one bit "1" produce the matrix [F]: each column of the matrix [F] is then formed by the code symbol a associated with such a base vector b. An error in b may cause at the most one one-bit error in a. Therefore, each column of the matrix [F] may contain no more than one "1".
In the system according to the present state of the art, each data word can be reconstructed from the relevant code symbols of an arbitrary choice of k (in the present embodiments: k=2) computer modules. For the generator matrices [G o ] . . . [G n ] of the reducing encoders, each choice of k rows of the matrix ##EQU1## results in a square non-singular matrix. Let such a matrix be referred to as: ##EQU2## This matrix consists of k×k coefficients which are elements of the Galois field GF(2 b in which b is the length of the symbol expressed in elements of GF(2), (bits). The matrix [G abc . . . ] has an inverse matrix [G abc -1 .sub.. . . ], so that the product [G abc . . . ]·[G abc -1 .sub.. . . ]=[I] is an identity matrix. Evidently,
[a°φφ . . . ]·[G.sub.abc . . . ]=[G.sub.a ],
in which [a°φφ . . . ] consists of k elements of the Galois field GF(2 b ), a° being the unity element and φ the zero element. It follows therefrom that:
[G.sub.a ]·[G.sub.abc.sup.-1.sub.. . . ]=[a°φ . . . ].
This may also be written as:
[G.sub.a ]·[I]·[G.sub.abc.sup.-1 .sub.. . . ]=[a°φ . . . ].
Because [G i * -1 ]·[G i *]=[I], the following may be written:
[G.sub.a ]·[G.sub.i *.sup.-1 ]·[G.sub.i *]·[G.sub.abc.sup.-1 .sub.. . . ]=[a°/ . . . ].
Let us define [G i *]·[G abc -1 .sub.. . . ]=[P] and previously we defined:
[F]=[G.sub.a ]·[G.sub.i *.sup.-1 ], so that [F]·[P]=[a°φ . . . ].
Because [G 1 *] and [G abc -1 .sub.. . . ] are both non-singular, [P -1 ] also exists, so that [P -1 ]·[P]=[I]; consequently,
[F]=[a°φ . . . ]·[P.sup.-1 ].
Thus far, [P] was considered as a matrix of k×k (in this case k=2) coefficients which formed elements of the Galois GF(2 b ) (in this case b=4). Without any loss of generality, the matrix [P] and the other matrices may be assumed to be binary matrices (in which case the coefficients are formed by bits), because the coefficients of GF(2 b ) are replaced by their companion matrices with coefficients of GF(2): ##EQU3## If the matrix [F] contained a row comprising only coefficients "0", the matrix [P -1 ] would also contain such a row (i.e. one of the first four rows). However, this would mean that the matrix [P -1 ] would be singular, and it has been proved that that is not the case. Therefore, each row of the matrix [F] contains at least a single "1". Some obvious choices for [F] are the following:
[F]=[a°φ] (1)
[F]=[φa°] (2)
[F]=[a°a°] (3)
Case (1) means that the first half of a data word encoded by the relevant second encoder is copied in the input/output memory on the code symbol to be formed by the reducing encoder of the relevant computer module. Case (2) means that the other half data word is copied on the relevant code symbol in the input/output memory. In these cases a bit error in the copied half is translated into a bit error in the code symbol. A bit error in the non-copied half has no effect on the information in the code symbol. Consequently, the associated processor module cannot perform a periodic test on the non-copied half. Similarly, other configurations can be found for the matrix [F] for other values of the variables n (number of modules, in this case 4), k (number of data symbols in a data word, in this case 2), and b (number of bits in a symbol, in this case 4). It appears from the foregoing that [G i ] matrices suffice for the second encoder generator matrix, for which matrices [G i *] is non-singular, and
[G.sub.i *.sup.-1 ]·[G.sub.i ]=[F],
in which [F] is a matrix having coefficients in the Galois field GF(2), with the characteristics that each row contains at least one "1" and each column contains at the most one "1". In this case we use the term "companion matrices" whose elements are selected from the Galois field GF(2),
A series of generator matrices for case (1) will now be given by way of example; the derivation of the corresponding matrices for the case (2) is extremely elementary. FIG. 2 shows an example of a generator matrix [G] for the relevant code. This generator matrix has already been given by way of example in the previous U.S. Pat. No. 4,512,020, said Application being incorporated herein by way of reference. FIG. 3 shows the separate generator matrices for the relevant reducing encoders, second encoders and decoders.
It follows from the foregoing that: [G i ]·[G i * -1 ]=[a°φ]. It follows therefrom that the first row of the matrix [G i *] must be equal to the first line of the matrix [G i ]. The lower (second) line of the matrix [G i *] must be chosen so that this matrix is non-singular. It has been found that this can already be achieved within the limitation of the code as defined in the last-mentioned Patent Application by the lines [a°φ] or [φa°]. It is to be noted, however, that these are not the only possibilities; however, the above possibilities can be readily implemented. The generator matrices for the decoders follow directly therefrom.
Next said case (3) will be considered. Therein, the code symbol is formed by bit-wise and modulo-2 addition of the content of the first and the second half of the word in the input/output memory. Each bit error in the input/output memory is thus mapped on the associated code symbol. The error frequency induced by the input/output memory is thus doubled ceteris paribus. It is an advantage, however, that the entire input/output memory can now be tested by the processor module 20 . . . 26. FIG. 4 shows the generator matrices for the reducing encoders, second encoders and decoders. The following is applicable:
[G.sub.i ]·[G.sub.i *.sup.-1 ]=[a°a°] or [G.sub.i ]=[a°a°]·[G.sub.i *.sup. ].
In order to save parts, the first row of the matrix [G i *] can again be chosen from [φa°] and [a°φ]. In the second case:
[G.sub.i ]=[G.sub.i1 G.sub.i0 ]=[a°a°]·[a.sub.1 °φ.sub.j ].
It follows therefrom that
G.sub.i1 =a°+a.sup.i a.sup.i =G.sub.i1 +a°
G.sub.i0 =a.
If a j ≠0, [G i ] is non-singular and there is no problem. On the other hand, if G i0 =φ, the value [φa°] must be chosen for the upper row of [G i *].
FIG. 5 illustrates another possibility for the matric [F] for the same values of the variables n, k, b, and the consequences thereof for the generator matrices. For the matrix [F] a configuration is deliberately chosen which not only comprises two submatrices associated with two elements of the Galois field GF(2 4 ). The matrix [F], FIG. 5, first line, satisfies the requirements stated above. This associated set of generator matrices [G i *] is found by way of the associated matrix [G i * -1 ] as follows:
[G.sub.i ]·[G.sub.i *.sup.-1 ]=[F].
The implementation may be as follows. Because [G i ] and [F] are extended from matrices [G i '] and [F'] which are non-singular, surely
[G.sub.1 *.sup.-1 ]=[G.sub.1 '.sup.-1 ]·[F'].
The [G i * -1 ] found is usually only one of the feasible solutions. Let us assume: [G 3 ']=[a°φ] which matrix has been shown previously. [G 3 '] and [F'] may then be shaped as shown on the second line in FIG. 5. Because [G 3 ']=[G 3 ' -1 ], [G 3 * -1 ]=[G 3 ' -1 ]·[F], resulting in the same matrix as [F'].
The generator matrix [G 2 ] is determined similarly:
[G.sub.2 ]=[φa°].
[G 2 '] can be found in accordance with FIG. 5, third line, as a permutated identity matrix. [G 2 ' -1 ]=[G 2 '] and, using the previously determined matrix [F'], [G 2 * -1 ] can be determined in accordance with FIG. 5, fourth line, Therefrom, [G 2 *] as shown on the second line of FIG. 5 can be determined.
The matrix G 1 is: [a 7 a 11 ].
In accordance with previously stated criteria, i.e. the aim for simplicity, ##EQU4## It follows therefrom for the inverse: ##EQU5## For the matrix [F], the previously determined value can be used again, so that the matrix [G 1 * -1 ] is found in accordance with FIG. 6, first line; this Figure is a continuation of FIG. 5. Finally, the generator matrix [G 1 *] is calculated as [G 1 *]=[F' -1 ]·[G' 1 ], in accordance with FIG. 6, second line..
Finally, the matrix [G o ]=[a 11 a 7 ]; for the sake of simplicity, ##EQU6## The relevant generator matrices are found from [G o * -1 ]=[G 1 ' -1 ]·[F], and [G o *]=[F' -1 ]·[G o '], as shown on the third line and the fourth line, respectively, of FIG. 6. | A multiprocessor computer system having n parallel-operating computer modules which each include a processor module, a memory module and a data word reconstruction module, wherein each module of said system processes the same piece of data simultaneously and in parallel. The data words are applied to a reducing encoder so that code symbols stored in the relevant computer modules form a code word. The relevant error-correction code has a simultaneous correction capability in at least two code symbols. Each data word reconstruction module receives the entire code word in order to reconstruct the data word therefrom. Each computer module also has an input/output memory module. This module receives a coded data word which is decoded when it is presented again. Decoding is performed so that each bit in the input/output memory is mapped on at the most one bit of the associated memory module. | 6 |
INTRODUCTION
[0001] The present invention concerns the field of multi-function wireless terminals, in particular for short range communication between the terminals.
BACKGROUND ART
[0002] The need to enhance the communication between participants of the same meeting is not new. Accenture and Hewlett-Packard have presented a solution based on the iPaq, a pocket PC able to receive news and the list of attendees, send or receive messages or locate a particular place on the map. This solution is used by the World Economic Forum in Davos (CH) since many years. Each participant receives such an iPaq device with bidirectional communication capabilities. The participant is therefore always kept up to date with the latest events or reports. The communication capabilities were mainly toward the management center for receiving the data and sending messages. The direct communication between terminals is limited to standard portable phone abilities, i.e. sending business card via Bluetooth or infrared.
[0003] A new generation of terminals is proposed in the PCT/IB2005/052537 in which the communication capabilities have been greatly improved. Thanks to an additional communication channel, a genuine communication between two terminals was possible. This capability was also used for detecting the proximity of a particular terminal by watching the radio signal of the nearby terminals and discriminating according to a filter set by the user.
[0004] Due to the lack of precision of such detection method, only rough positioning is possible and the distance from a given terminal to a target terminal was only an estimation.
[0005] The announcement of a new technology allowing high precision distance measurements between two or more devices opens new field of application. Taking advantage of this new technology allows distance measurements with a precision in the order of 10 cm.
BRIEF DESCRIPTION OF THE INVENTION
[0006] The aim of the present invention is to provide new technical features to participants using a position determination module in their terminals. Today, user-friendly management of a multitude of functions is limited or simply not possible due to the impossibility to precisely locate a participant. All functions of the terminal must be made accessible via menus at all times, leading to complex and deep menu trees that are hard to memorize. It is the object of this invention to propose a wide range of applications easily available to the user.
[0007] According to a first object of the invention, it is proposed a wireless interactive communication device comprising a microprocessor accessing a memory, this communication device comprising a communication channel to receive and store in the memory a database containing the spatial model of the venue where the device is used, this device furthermore comprising a facility to determine its position by listening to synchronized fixed beacons, allowing the communication device to retrieve from the spatial model the area of the venue where it is located, subsequently allowing the communication device to adapt its functionality and or wireless communication behavior to the area where it is located, allowing the reduction of the interactive communication device power consumption and/or the optimization of the wireless communication bandwidth.
[0008] According to a second object of the invention, it is proposed a method to broadcast location dependent commands to a wireless terminal, said terminal comprising means to dynamically determine its physical position, said method comprising the steps of discriminating the commands which refer to the location area where the terminal is located, executing this command, said command consisting of enabling a function on the terminal, this function being related with an event in the location area.
[0009] According to a third object of the invention, it is proposed a method to define a subset of broadcasted audio or video channels among a set of audio or video channels on a wireless terminal comprising means to dynamically determine its physical position, this method comprising the steps of receiving the set of audio or video channels, checking if the reception of at least one channel is allowed according to the current location of the terminal, defining the subset of channels according to the location of said terminal and allocating the subset of channels to selectable channels by the user.
[0010] According to a fourth object of the invention, it is proposed a method to manage the reception of messages on a wireless terminal, said terminal comprising means to dynamically determine its physical position. This terminal receives an instruction from a management center to enable/disable the prompt of the received messages to the terminal's holder related to a location area, this method comprising the steps of receiving a message from the management center, determining according to the current physical location and the location area defined in the instruction message if the reception of messages is disabled, in the positive event, storing said message without prompting the user. When the current physical location is outside the location area defined in the instruction message, the terminal prompts the user informing the same of the received messages. In an alternative case, the management center sends an enable instruction message allowing the terminal to inform the user of the received messages regardless of the current location.
[0011] According to a fifth object of the invention, it is proposed a method to control the access of a wireless terminal's holder to premises at an inlet, said terminal comprising means to dynamically determine its physical position, this method comprising the steps of detecting the presence of a person by detection means located in the inlet, obtaining the physical location of the terminal and if a terminal is physically present in the inlet, allowing the terminal's holder to access to the premises.
[0012] According to a sixth object of the invention, it is proposed a method to identify a wireless terminal's holder to premises, said terminal comprising means to dynamically determine its physical position, this method comprising the steps of acquiring an image of the premises, receiving the physical position of the terminal, retrieving the name of the terminal's holder, displaying the image of the premises together with the name of the terminal's holder at the visual location corresponding to the location of said terminal.
BRIEF DESCRIPTION OF THE FIGURES
[0013] The invention will be better understood thanks to the attached figures in which:
[0014] the FIG. 1 illustrates the wireless terminal listening to a plurality of beacons,
[0015] the FIG. 2 illustrates the automatic command mode,
[0016] the FIG. 3 illustrates the step of filtering channels depending of the location,
[0017] the FIG. 4 illustrates an optical barrier which will be crossed by a terminal's holder,
[0018] the FIG. 5 illustrates how an image acquired with a surveillance camera is enhanced with the name of each person.
DETAILED DESCRIPTION OF THE INVENTION
[0019] The FIG. 1 shows how a wireless terminal ME determines its current location. This method uses at least two beacons BE 1 , BE 2 which are able to interact with the terminal ME. This interaction has the form of a bidirectional communication between the two beacons and the terminal and uses the response delay. This can be the base of a vector determination from the known location of the beacon. Another measurement with another beacon allows the determination of another vector, the intersection of these two vectors defining the current location of the terminal ME. In some cases, we can obtain two intersections and this uncertainty can be solved by using either the location's history (previous location) or a third and in some cases fourth beacon. While using the location's history, the proper intersection is the one which is the nearest from the last known unambiguous location.
[0020] The location determination can be either active or passive. In the active mode, the beacons interact with the terminal. An exchange protocol allows the terminal to determine the distance from a beacon. After determining the distance to multiple beacons the exact position is calculated.
[0021] In the passive mode, the beacons are broadcasting synchronized signals. The terminal listens to these synchronized signals. The use of 3 or more beacons also named anchors allows the terminal to calculate its position using time difference of arrival method.
[0022] This position information can be transmitted to nearby terminals in an identification packet at a regular interval. Thanks to this information, a terminal can create a 3D representation of all terminals around it.
[0023] According to the first embodiment of the invention, the wireless interactive communication device ME comprises a memory with a database in which the spatial model of the venue is stored. More generally, the walls, gates, doors, stairs are defined in this database for a specific conference area. Due to the fact that such device is battery powered, special care of the power consumption is taken. The behavior of the device can vary according to the definition of the current location of the device. This behavior can not only vary in function of the location but also in function of the time. For example, if the participant is in the restaurant, the rate to determine its location can be lowered, in particular if no change was noticed during a predefined period.
[0024] In the same manner, during a conference which is defined by a starting and ending time, the participant is assumed to be at the same place and the position detection rate is lowered.
[0025] Additional means can be used to detect a terminal's movement such as a vibration detector. No vibration of the terminal means that the location was not modified. When vibrations are detected, the location determination module is fully awake.
[0026] The rate of the position messages sent to the management center can be influenced by the location. Depending on the area where the terminal is located, the number of messages can vary. This is also another method to efficiently manage the bandwidth allocated to such messages. In case of particular event taking place in a room, e.g. during a voting process, the position messages of the terminals in this room are temporarily disabled to allocate full bandwidth to the voting responses.
[0027] According to the second object of the invention, the terminal ME, in view of the high number of functions proposed to the user, has a complex and deep menu tree to access all these functions. Each portable phone is acquainted with such an interface and the user spends a lot of time to retrieve a specific function. The purpose of the present invention is to reshape the proposed functionalities of the terminal according to the event currently held at a location area. Only the terminals which are present within this location area will react and switch from the normal mode of operation to the new mode of operation. One example is a vote taking place at the room B 2 . The upper FIG. 2 shows a terminal in standard mode displaying the default menu. In case that not all present participants are allowed to vote, the management system only enables participants allowed to join this voting process. A message is sent from the management center to the selected participants with a voting command, the location area where the voting process takes place and possibly the question to be answered. The terminals receiving this command first check if the location area condition is met. In the contrary, the terminal simply ignores this command.
[0028] In case that the terminal is located within the location area defined in the command, the default menu is replaced by a specific menu related to the voting process without any user's intervention. This is illustrated by the lower FIG. 2 . When the selection is done, the terminal sends a message back to the management center which gathers all responses. In an alternate embodiment, the message sent from the management center can comprise a timeout to switch back to the standard menu, in particular, if no action is taken by the user. Alternatively, the management center can also send a cancellation command to restore the standard menu on the terminals. The application will exit automatically, when the user walks out of the session.
[0029] It is to be noted that, according to an embodiment, the alternate menu enabled by the command can't be accessible in normal operation. Some functions remain hidden to the user even if he/she is entering the standard menu and trying to find the alternate menu.
[0030] According to the third object of the invention, the wireless terminal ME is used to receive audio channels e.g. for simultaneous translation. The known solution is to send those channels via infrared, which automatically limits the area covered to the room where transmitters are installed, since the infrared signal does not penetrate walls. When radio waves are used instead of infrared waves, an additional problem is raised when several events take place at the same time at close locations. It is then necessary for a participant to choose the conference in its location area and then select the translation language. If the participant leaves the location area of this conference and joins another conference, he will continue to receive the translation of the previous conference.
[0031] Another drawback of this situation is the confidentiality issue. The infrared waves were naturally limited to the conference room and no one outside this room could receive the translations. This is in some cases very important. If negotiations are in progress in a room, the translation channels should not be accessible outside the room.
[0032] The present invention proposes a smart filtering method based on the current location of the terminal. Several translation channels are transmitted by the management center covering more than one room or event. Depending of the current location of the terminal, the same filters the channels not referring to the location area where the terminal is located. The user can simply choose a language without having the need to select the appropriate room. The terminal proposes the channels A, B or C which only refer to the location area. When the terminal leaves the location area, the reception of the channels is automatically disabled.
[0033] The same can be applied for video or images. For example the chart or power-point presentation currently displayed beside the lecturer is sent through a channel automatically selected by the terminal depending of the location of same. In case that a user has selected to display lecturer support, using the location area attached to the image data, the terminal can select among different images, the one that corresponds to the terminal's location. This simplifies the selection proposed to the user by eliminating all information not relevant for this session.
[0034] In order to secure the channel's reception, beside the filtering function based on the current location, an additional level of security can be achieved by encrypting the channels. Yet another level of security can be achieved by sending the corresponding key only to the terminals located in the conference location area.
[0035] This function can be applied to messages instead of audio channels. This wireless device receives a general purpose messages and comprises discriminating means for checking if the reception of at least one message is allowed according to the current location of the device. The message contains an indication in which location the reception is allowed (positive discrimination) or in which location the reception is not allowed (negative discrimination). The discriminating means comparing the current location and the received location indication and allowing (or blocking) the messages to be prompted to the user according to the result of this comparison.
[0036] According to the fourth embodiment, the wireless terminal could receive messages. These messages can be generally addressed (or group addressed) or dedicated to only one terminal. Usually, once the message arrives to the terminal, the same gives a signal to the user, through a sound or a vibration. The present invention addresses the problem of disturbing the user with messages at an inappropriate time. The location determination means of the terminal are used to determine if the terminal is allowed to prompt the user with received messages. The prompting decision is made based on information sent by the management center, which comprises the location area where the disabling state is to be applied. The terminal checks whether it is located in that area and acts accordingly. The location is a room where a conference takes place. From the time the conference begins until the conference ends, the location area defined by the room is disabled from receiving messages.
[0037] According to a first embodiment, the terminal executes the function of enabling or disabling the message reception. When a message arrives, verification is carried out to check whether the current location is within a disabled location area. In the positive event, the terminal stores the message without giving any notice to the user. When the terminal goes out the disabled location area, it automatically enables the processing of the messages and prompts the user if messages have been received in the meantime.
[0038] When the session is over, the management center sends a message to release the terminal restrictions allowing it to prompt the user with the messages received in between.
[0039] According to another embodiment, the management center handles all enabling and disabling functions by refraining from sending messages to terminals located in a disabling area. The management center gathers the location of each terminal and when a message should be addressed to a terminal, the center checks the current state of the location where the terminal is located and sends or suspends the message to it.
[0040] When the management center detects that the terminal has left the conference's room, the messages previously suspended are sent.
[0041] One problem that the management of the conference is faced with is the proper detection of the end of a session. The starting time is usually not a problem since it is scheduled in advance and the disabling message can be sent in advance. It is to be noted that such disabling command could be accompanied with a time at which the command takes effect. An additional time could also be attached to this message to set a time at which the restriction is released.
[0042] However, a session can last more that the foreseen time and the generation of prompting signals at the expected end time can have a disastrous effect if the session is still continuing. This is the reason why the management center can use the indication that a percentage of the participants have left the conference room to automate the end status of the conference. According to an example, the number of participants (or terminals) is counted during the conference (the number at the middle of the conference is a good base) and when a predefined percentage (e.g. 30%) of this number has left the conference room, this will be the time to send the releasing command.
[0043] According to the fifth object of the invention, the terminal is used to control the access of a terminal's holder to premises. The FIG. 4 shows an optical barrier to detect the presence of a person positioned in an inlet accessing the premises. Various techniques can be used based on ultra-sound, infrared or Doppler detectors to detect the entry into another room.
[0044] When detection occurs, the management center checks the presence of the terminals in that area and in particular if the terminal positioned where the detection means are located has the right to go in.
[0045] Alternatively, if no terminal is detected, an alarm can be generated or the next gate remains closed.
[0046] More generally, the terminal can warn the user when entering in a non-allowed zone. The terminal stores data relative to the permission to specific areas in relation to the terminal's holder. When the terminal moves to a restricted area, the terminal sends a signal to warn the user.
[0047] This feature allow e.g. to keep the doors open as long as authorized persons are entering. When detection is made at the inlet without the corresponding detection of the terminal's older, the door is closed. If the access control is further assisted by a control person, the attention is given to that person only in case that non-terminal's older is present at that door.
[0048] According to the sixth object of the invention, the terminal's location serves to the identification of a person on an image. Control cameras acquire images, which are displayed on a screen. As shown in the FIG. 5 , the physical location of each terminal's holder located on the acquired image is determined, so as to produce an image with the name (NM 1 , NM 2 . . . NM 5 ) beside each person. The image processing first isolates each terminal and obtains its physical location. The image is therefore arranged so that for each position recognized, the owner's name is attached to the position determined. Thanks to the location information received from the terminals, the system can match an image with identification and therefore can apply the name on the displayed image.
[0049] According to an alternative embodiment shown in FIG. 5 , the initial picture taken while registering the terminal's holder, is displayed in an external region of the displayed image for easily comparing the genuine holder and the person's face currently shown. The system can additionally draw a line between each person identified in a crowd and their respective initial pictures. This system speeds up the identification of alien, which on one hand do not bear a terminal or on the other hand use the terminal of another person. Special marking of the image being possible by the system in the first case, the second case still needs a human comparison. | The possibility to determine with high precision the position of a wireless interactive communication device within pre-defined boundaries opens new range of services, which are location based.
According to the invention, it is proposed a wireless interactive communication device comprising a microprocessor accessing a memory, this communication device comprising a communication channel to receive and store in the memory a database containing the spatial model of the venue where the device is used, this device furthermore comprising a facility to determine its position by listening to synchronized fixed beacons, allowing the communication device to retrieve from the spatial model the area of the venue where it is located, subsequently allowing the communication device to adapt its functionality and or wireless communication behavior to the area where it is located, allowing the reduction of the interactive communication device power consumption and/or the optimization of the wireless communication bandwidth. | 8 |
FIELD OF THE INVENTION
[0001] The invention concerns a room heating system with a heatable floor having a floor heating system, and a room thermostat having a room air sensor and being connected with a regulating unit for the floor heating system.
BACKGROUND OF THE INVENTION
[0002] Such a room heating system is, for example, disclosed in the company brochure “Wireless regulation for floor heating” of Danfoss A/S, No. VD.78.K3.02, January 2002. The room thermostat measures the room temperature, and in dependence of the room temperature influences the floor heating system so that the temperature of the room air can be kept substantially constant.
[0003] The floor heating system can have different embodiments. Commonly known are, for example, floor heating systems working with a heat carrying medium, for example hot water. In this case, the regulating unit influences the flow of this heat carrying medium through the floor. The floor then acts as heat exchanger, which supplies the heat from the heat carrying medium to the room air.
[0004] In another embodiment, the floor heating system can work electrically. For this purpose, resistance heating elements are then inserted in the floor. The regulating device then influences the current, which flows through the resistance heating elements. Also in this case, the floor supplies the increased temperature, which is generated in the resistance heating elements by the flowing current, to the room air.
[0005] To many people a room heating via the floor is very comfortable. However, floor heating systems involve problems, which do not occur in connection with radiators. Depending on the nature of the floor used, it is important to have the floor temperature under control. When, for example, a wooden floor is concerned, the temperature must be limited to prevent a drying of the wood and a subsequent damaging of the floor. On the other hand, with a floor covered by tiles, stones or slabs, it is desired to keep a minimum temperature to avoid that a user gets “cold feet”.
[0006] To determine the floor temperature, a temperature sensor can be built into the floor. In many cases, a hollow space is provided, for example a pipe, in which the temperature sensor can be located. However, with such a location, some regulation problems occur. Due to the inertia of the floor, delays occur in the measuring, so that a regulation takes place too late, which causes an overshoot. Further, the position of the temperature sensor in the floor must be selected very carefully, as the future fitting up of the room can have an influence on the measured temperature. When, for example, a wardrobe is placed exactly over the temperature sensor, the wardrobe will reflect heat back to the floor, which influences the measuring of the floor temperature.
SUMMARY OF THE INVENTION
[0007] The invention is based on the task of improving the temperature control in a room.
[0008] With a room heating system as mentioned in the introduction, this task is solved in that the room thermostat has a surface temperature sensor, which determines a temperature on the surface of the floor from a distance.
[0009] Thus, this surface temperature sensor is a “remote sensor”, which can be located at a distance to the floor. This will eliminate practically all the problems involved in bedding the temperature sensor in the floor. Further, the room thermostat is combined with the surface temperature sensor, so that a compact component is achieved. This component is only negligibly or not at all larger than a traditional room thermostat, so that for the user of the room changes are practically not noticeable. Further, also the communication between the regulating unit and the individual sensor, that is, the room air sensor and the surface temperature sensor, is simplified. When these two sensors are located next to each other, it is possible that one single transmission path to the regulating unit will be sufficient. The location of the room thermostat merely has to be chosen so that on the one hand the room thermostat can determine the room air temperature; on the other hand, however, also the surface temperature of the floor. This leaves more freedom for decorating the room, as the structural measures to be taken when locating the surface temperature sensor require substantially less efforts than bedding the temperature sensor in the floor.
[0010] Preferably, the surface temperature sensor is an infrared sensor. By means of an infrared sensor, the temperature of the floor surface can be determined relatively exactly, also over a certain distance. Such an infrared sensor is, for example, known from DE 297 16 166 U1. However, here the temperature is not controlled in a closed room, which would be the case according to the present invention.
[0011] Preferably, the room thermostat is wirelessly connected with the regulating unit. Thus, no mounting of wires is required to ensure the communication between the room thermostat and the regulating unit. On the contrary, the wireless connection can take place via electromagnetic waves, for example, radio or light. This gives even more flexibility for locating a room thermostat in a room, that is, changes in decorating can be compensated very quickly. It is merely required that the surface temperature sensor can “see” the floor, that is, can perform measuring over a certain distance.
[0012] Preferably, the room thermostat gives the surface temperature sensor a priority with regard to influencing the regulating unit. In other words, the influence of the surface temperature sensor on the regulating unit is larger than the influence of the room thermostat sensor. This considers the requirement that the temperature of the floor is a decisive size for influencing the regulating unit.
[0013] Preferably, the room thermostat has a minimum/maximum value selection unit for the surface temperature. Thus, it can be selected, if the floor temperature should be limited to a minimum value or a maximum value. When, for example, the floor has a wooden surface, it is desired to set the temperature at a maximum of 25° C. When now assuming that the room temperature shall be 26° C. and the floor temperature is set to 25° C., the floor heating system will supply heat until the floor temperature reaches 25° C. Also when the temperature is lower, for example, only 24° C., for example caused by an open window, no more heat will be supplied, when the floor temperature has reached the maximum limit. When, however, to avoid cold feet, the temperature of a tiled floor in the bathroom is set at at least 27° C. and at the same time the room temperature is set at a lower value, for example 23° C., the floor heating system is only turned off, when at the same time the floor temperature is at least 27° C. This also applies, when the room temperature exceeds its desired value, for example because the sun shines into the room.
[0014] Preferably, the room thermostat is located at a height in the range of 1.2 to 1.8 m over the floor. In this height, the room thermostat has the possibility of determining the room air temperature on the one side and the surface temperature of the floor on the other side with a sufficient accuracy, so that the temperature control in the room can be performed with the required reliability.
[0015] Preferably, the room thermostat is located at a maximum distance of 0.3 m from a wall. Thus, it interferes very little with decorating the room.
[0016] Preferably, the room thermostat determines the surface temperature at certain intervals. Particularly, when the room thermostat is wirelessly connected with the regulating unit, also wires for an energy supply to the room thermostat are undesired. Thus, the room thermostat is supplied from batteries. These should last as long as possible. When the surface temperature of the floor is only determined from time to time, electrical energy for this process will also only be required from time to time. The intervals, at which the surface temperature is determined, may be fixedly preset. However, they can also be chosen freely by the user. Finally, it is also possible to generate these intervals by means of a random generator.
[0017] It is preferred that the room thermostat only passes on values of the surface temperature to the regulating unit, when a change exceeds a predetermined value. A relatively large consumption of electrical energy occurs, when the data from the room thermostat are transmitted to the regulating unit. This transmission is only made, when absolutely required. This is only the case, when the values of the surface temperature have changed so that the regulating unit must interfere to maintain or re-establish a desired state.
[0018] It may be advantageous that the room thermostat only transmits surface temperature values to the regulating unit, when a medium surface temperature value changes by more than a predetermined value over a predetermined period. For example, four measurings can be made over a period of 15 to 30 minutes. Only when the medium value increases or decreases, this change is transmitted to the regulating unit. Thus, short-term influences, for example from sun radiation, people or animals in the room, are absorbed in such a manner that they cause no additional energy consumption.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In the following, the invention is described on the basis of a preferred embodiment in connection with the drawings, showing:
[0020] FIG. 1 a schematic view of a heating system with several rooms, and
[0021] FIG. 2 a schematic view of a room heating system.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] FIG. 1 shows a schematic view of a heating system 1 with three rooms 2 , 3 , 4 , each being provided with a floor heating system 5 to 7 . In the present case, each floor heating system 5 to 7 is made as a heating hose, that is, a pipe fitted in a meander-shape, which is fitted in the plaster 8 ( FIG. 2 ) of a floor 9 . A heat carrying fluid, for example hot water, then flows through these floor heating systems 5 to 7 .
[0023] The supply of the floor heating systems 5 to 7 takes place via an inlet connector, to which the floor heating systems 5 to 7 are connected. The control of the heat carrying fluid flowing through the floor heating systems 5 to 7 occurs via a control module 11 , to which the floor heating systems 5 to 7 are connected. For each floor heating system, the control module 11 has a controllable valve 12 to 14 . Depending on the released opening degree of the valves 12 to 14 , a smaller or larger amount of the heat carrying fluid is flowing through the floor heating systems 5 to 7 .
[0024] The control module 11 is controlled by a control device 15 . The control device 15 is connected with a zone control 16 , on which certain parameters meant to apply for the whole heating system 1 can be set via setting elements 17 a, 17 b.
[0025] Each room 2 to 4 has a room thermostat 18 to 20 , which communicates with the control device 15 via a wireless connection 21 to 23 , feeding back, among other things, the actual room temperature, that is, the room air temperature, to the control device 15 . A desired room air temperature can be set for each room 2 to 4 via a setting device 24 to 26 . The zone control 16 can be used for programming the control device 15 .
[0026] As can be seen from FIG. 2 , each room thermostat 18 has, besides the setting device 24 , also a room air sensor 27 , with which the room air temperature can be determined. Additionally, each room thermostat also has a surface temperature sensor 28 , by means of which the temperature at the surface 29 of the floor 9 can be determined. The surface temperature sensor 28 is, for example, an infrared sensor, which receives the heat radiation originating from the surface 29 . For this purpose, it is merely required that the surface temperature sensor 28 can “see” the surface 29 , that is, a connection by way of radiation is possible.
[0027] The fact that the floor 9 temperature is determined directly on the surface 29 results in a faster reaction of the floor heating. When, for example, sunlight reaches the surface 29 , a higher temperature will occur here. This can be considered in connection with the supply of the floor heating systems 5 to 7 . The same applies for water on the floor, for example when a person leaves the bath or the shower. Until now, it has been necessary to wait for an evaporation, which caused a cooling of the floor, which then had to reach the built-in sensor. In the solution shown here, the water is immediately detected by the surface temperature sensor 28 , and a correspondingly fast reaction is possible.
[0028] The temperature, which is desired on the floor 9 surface 29 , depends on, among other things, a layer 31 , which forms the floor 9 surface.
[0029] When this layer 31 is made of wood, it is endeavoured not to exceed a predetermined temperature, to prevent a drying of the wooden floor. For example, the temperature on the surface 29 should not exceed 29° C.
[0030] When, however the layer 31 consists of tiles or slabs, it is desired to set a certain minimum temperature of, for example, 25° or 27°, so that a user will not get “cold feet” when running around on the floor 9 surface 29 .
[0031] Accordingly, the room thermostat does not only evaluate the signals of the room air sensor 27 , but also the signals of the surface temperature sensor 28 . Here, the user can decide if he wants a predetermined minimum value of the surface temperature or a predetermined maximum value of the surface temperature. As stated above, a maximum value, which shall not be exceeded, will, for example, be set for a wooden floor, whereas with a tiled floor a pre-determined minimum temperature is set.
[0032] It may now be ensured that the output signals of the surface temperature 28 are treated with a higher priority than the output signals of the room air sensor 27 . This setting can be made already in the room thermostat 18 , which then prefers the transmission to the zone control 16 of the signals originating from the surface temperature sensor 28 . However, this prioriting can also be made in the zone control 16 or even in the control device 15 . Together with the control device 15 and the control module 11 , the zone control 16 forms a regulating device, which influences the floor heating.
[0033] The priority can briefly be explained as follows: When the layer 31 is of wood, and the desired room temperature is set to 26° C. and the maximum floor temperature to 25° C., the floor heating system 5 is supplied with heat, until the floor temperature reaches 25° C. This is determined by means of the surface temperature sensor 28 . When the room temperature drops to 24° C., for example because a window is opened, additional heat will not be supplied, as the temperature of the floor 9 forms the limit.
[0034] When, however, the layer 31 consists of tiles, whose temperature shall be at least 27° C., and at the same time the room temperature is set to 23° C., the heat supply is only turned off, when the temperature at the floor 9 surface 29 is at least 27° C., also when an increased sun radiation or several people in the room have caused the room temperature to exceed the predetermined 23° C.
[0035] The room thermostat 18 is mounted in a height A in the range from 1.2 to 1.8 m over the floor 9 . It has a maximum distance of 0.3 m to a wall 32 , on which it is mounted.
[0036] The fact that the room thermostat 18 communicates wirelessly with the zone control 16 causes the heating system 1 to be very flexible. There are no problems in reacting to changes of the fitting up of each in individual room 2 to 4 . Such a system is also easy to service, as a consumer can easily determine if a room thermostat 18 is defective or not. Typically, such a heating system 1 has several room thermostats 18 to 20 , and one of the other room thermostats 18 to 20 can be used to determine if only the individual room thermostat or the complete system is defective. When, for example, it is desired to determine, if the transmission path between the room thermostat 18 and the control device 15 works, a light emission diode and a button, which is provided on the room thermostat 18 , can be used. For reasons of clarity, these are not shown here. When the button is pressed, the diode lights up, and the room thermostat 18 will attempt to get in touch with the control device 15 . When a communication between these two units is possible, the diode will turn off. The user can then see immediately, if a connection has been established or not.
[0037] With a wireless communication between the room thermostat 18 to 20 and the zone control 16 , each room thermostat 18 to 20 is supplied with the required electrical power from batteries. In order to ensure the longest possible life of the batteries, it is advantageous, when the room thermostats 18 to 20 do not constantly perform measurings and transmit data.
[0038] Therefore, it is ensured that a measuring of the surface temperature is only made at certain intervals. These intervals can be fixedly preset or freely selected. They can also be generated by a random generator. When the measured surface 31 temperature shows no large variations, no data are transmitted to the zone control 16 . Also sudden temperature changes, which, for example, occur because of sun radiation or a domestic animal, which lies down under the surface temperature sensor, can be filtered out in a simple manner. To save current, but also to avoid too large variations in the heat supply, not every increase is passed on immediately. On the contrary, it can be attempted to form a medium value over a predetermined number of measurings and merely send information to the zone control 16 , when also this medium value reflects a temperature change. | A room heating system includes a heatable floor having a floor heating system, and a room thermostat having a room air sensor and being connected with a regulating unit for the floor heating system. The temperature control in a room is improved by providing the room thermostat with a surface temperature sensor, which determines a temperature on the surface of the floor from a distance. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 12/504,491, entitled “DROP-IN CHLORINATOR FOR PORTABLE SPAS,” filed on Jul. 16, 2009, the contents of which are hereby incorporated by reference herein in its entirety.
FIELD OF INVENTION
This disclosure relates to water purification particularly with respect to water containing vessels such as spas, hot tubs, whirlpools, pools and the like and to a chlorinator or oxidizer generator suitable for such purpose.
RELATED ART
Portable spas have become quite popular as a result of their ease of use and multiplicity of features such as varied jet and seating configurations. Maintaining appropriate water chemistry and sanitation is of course important to enhancing the spa user experience.
SUMMARY
The following is a summary of various features, aspects, and advantages realizable according to various illustrative embodiments of the invention. It is provided as an introduction to assist those skilled in the art to more rapidly assimilate the detailed discussion which ensues and does not and is not intended in any way to limit the scope of the claims which are appended hereto in order to particularly point out the invention.
An illustrative embodiment of a portable spa drop-in chlorinator includes a housing having an inlet at a first end, wherein an electrode assembly is mounted so that spa waters flows through the electrodes and out of a second end of the device. When an appropriate voltage is applied, the electrodes interact with the fluid within the chlorinator to generate various oxidizing agents. In one embodiment, the chlorinator is cylindrical and is sized to fit within the central opening of a filter element located in a filter compartment of a portable spa.
In one embodiment, respective outer electrodes comprise titanium, while inner electrodes comprise doped diamond particles embedded in a plastic mesh substrate. In other illustrative embodiments, the doped diamond surface comprises the surface of a whole diamond electrode. In other illustrative embodiments, the diamond coated substrate may be selected from one of the group including titanium, niobium, silicon, platinum, or stainless steel. The electrodes may be solid metal plates or a mesh, the latter providing increased surface area.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a drop-in chlorinator according to an illustrative embodiment;
FIG. 2 is a top view of the chlorinator of FIG. 1 ;
FIG. 3 is a sectional view of the chlorinator of FIG. 1 taken at 3 - 3 of FIG. 1 ;
FIG. 4 is a schematic perspective view of an illustrative electrode assembly embodiment;
FIG. 5 is a top end perspective view of a drop-in chlorinator illustrating an electrode assembly according to FIG. 4 encapsulated in the device;
FIG. 6 is a top view of a second electrode assembly embodiment;
FIG. 7 . is a top schematic view illustrating one implementation of the electrode assembly of FIG. 6 ;
FIG. 8 is a top schematic view illustrating a second implementation of the electrode assembly of FIG. 6 ;
FIG. 9 illustrates one method of fabricating the assembly of FIG. 6 ;
FIGS. 10-12 are side schematic views illustrating various applications of chlorinators according to the illustrative embodiments; and
FIG. 13 is a side exploded view of a drop-in chlorinator assembly useful in the application of FIG. 12 .
DETAILED DESCRIPTION
FIGS. 1-3 depict an illustrative embodiment of a compact drop-in chlorinator 11 . The chlorinator 11 has a cylindrical housing 13 . An electrode assembly 15 comprising electrodes 25 , 27 , 29 , 31 is disposed vertically through the interior of the housing 13 and retained in the housing 13 , for example, by surrounding epoxy potting compound 17 . In an illustrative embodiment, epoxy 17 fills the interior of the cylinder 13 except for the space occupied by the electrode assembly. An electrical cable 19 supplies the device 11 with power and is also encapsulated by the epoxy potting compound 17 . Respective end caps 16 , 18 enclose the opposite ends of the housing 13 and assist in shielding the electrode assembly 15 from foreign matter, and are optional in various embodiments.
In one embodiment, spacers 20 may be used to space the electrodes apart. As seen in FIG. 5 , the epoxy potting may overlap the spacers 20 and edges of the electrodes 25 , 27 , 29 , 31 to hold the assembly 15 in position.
As illustrated in FIG. 4 , the electrode assembly 15 comprises a pair of outer electrodes and a number of inner electrodes. In the illustrative embodiment of FIGS. 1-4 , an outer electrode pair 21 and two inner electrodes 23 are provided. In this embodiment, the outer electrode pair 21 comprises a pair of rectangular titanium electrodes 25 and 29 , while the inner electrodes 23 comprise rectangular diamond electrodes 27 and 31 . Electrical leads L 1 , L 2 emanating from the cable 19 are welded or otherwise electrically connected to the respective titanium electrodes 25 , 29 . The inner electrodes 27 , 31 float electrically, i.e., are not connected to ground. Additional inner electrodes, for example, up to twenty, may be provided in alternate embodiments.
In one embodiment, the titanium electrodes 25 , 29 comprise titanium coated with ruthenium iridium. The diamond electrodes 27 , 31 may comprise 0.250 micron boron doped diamond crystals embedded in a teflon sheet (plastic matrix) such that diamond protrudes from each side of the sheet. The plastic matrix can be polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyethylene, polypropylene or other suitable materials. In alternate embodiments, the diamond electrodes can comprise either a coating on a substrate or whole diamond designed to be self supporting.
In a second electrode assembly embodiment 18 shown in FIG. 6 , a single central rectangular diamond electrode 41 is positioned between respective titanium outer electrodes 43 , 45 . In one embodiment illustrated in FIG. 9 , the electrode assembly 18 of FIG. 4 is tightly wrapped in a solid plastic film or tape 49 to keep the epoxy potting material out of the assembly 18 during fabrication. Again, the electrodes 41 , 43 , 45 may be separated and positioned by nonconductive, e.g. plastic mesh spacers 55 ( FIG. 7 ) or individual plastic spacers 57 ( FIG. 8 ). The central diamond electrode 41 floats electrically, i.e., is not connected to ground. The ends of the plate electrodes 43 , 43 may be passivated, e.g., ruthenium iridium coated to avoid corrosion and calcium scale.
Illustrative uses of a drop-in chlorinator are shown in FIGS. 10-12 . FIG. 10 shows an “over the bar top” application where the electrode cable 19 extends over the top edge of the spa 101 and suspends the chlorinator 11 in a floating position in the spa water.
FIG. 11 illustrates an embodiment wherein the electrical cable 19 passes through a pass through seal 107 in the sidewall 104 of the spa 101 into the spa tub or filter compartment, suspending the chlorinator 11 in one of those areas. The “dry” side 103 of the cable 19 may be located in the electrical equipment area of the spa 101 where it may interface with the spa controller circuitry as hereafter described in more detail
In the embodiment of FIG. 12 , the electrical cable 19 enters the filter compartment 105 and is dropped down the central cylindrical opening 106 of a filter element 107 . In this position, spa water is pulled through the electrode assembly, e.g. 15 , of the unit 11 by the pump of the spa water circulation system. Thus, the diameter of the cylindrical chlorinator 11 is selected to fit down the internal pipe of the filter element 107 . The chlorinator 11 may of course be located elsewhere in the circulation path of the spa. While a snug fit between the chlorinator 11 and internal filter pipe is shown in FIG. 12 , a looser fit is preferred, for example, providing a difference of 0.25 inches between the respective diameters of the two parts. In one illustrative embodiment, the drop-in chlorinator may be 1.3 inches in diameter and six inches in length or otherwise properly sized to fit down a filter stand pipe.
A drop-in chlorinator assembly particularly useful in the embodiment of FIG. 12 is illustrated in FIG. 13 . That assembly includes a chlorinator 11 , a stand pipe cap assembly 109 , and a pass through assembly 111 . The diameter of the pipe section 113 of the cap assembly 109 is selected such that it fits snugly into the central cylindrical opening in the filter element 107 , while the diameter of the rim 115 of the cap portion 117 is such that it abuts the top surface 121 of the filter element 107 . A strain relief device 119 is further provided and, when assembled, is attached to the cable 19 in the interior of the cap assembly 109 . The chlorinator 11 is thus suspended with the filter element 107 at a position determined by the length of L 3 of the cable 19 . The pass through assembly 111 includes a strain relief providing nut 122 , a pass through fitting 123 and first and second 9-rings 125 , 127 .
In various alternate embodiments, the electrodes are rectangular in shape and each comprise a boron doped synthetic diamond electrode tailored to flow rate. Such electrodes may be formed, for example, by chemical vapor deposition (CVD) of a very thin coating of boron or nitrogen doped diamond onto a niobium substrate. Such electrodes may be fabricated, for example, by Adamant, Chauxde-Fords, Switzerland. Other substrate materials may be used such as titanium, silicon, platinum or stainless steel. Embodiments may also be constructed of self-supporting diamond without using a substrate, such as may be obtained, for example, from Advanced Oxidation, Cornwall, U.K. In various embodiments, the substrates may either be solid plates or mesh, the latter providing increased surface area.
In operation of illustrative embodiments in an illustrative portable spa environment, a constant current mode of operation of the device 11 may be employed. In such case, a selected current flow through each electrode pair in the range of 1-5 amps, for example, 2 amps, may be used with a floating voltage across the outer electrode pair of 5-24 volts. In such embodiments, flow rates through the cell 11 may range from ½ gallon to 5 gallons per minute. An advantage of the chlorinator according to embodiments above is that it has low salt level requirements (0 ppm to 1000 ppm) vs. typical 3500-5000 ppm. Electronically, a constant current AC/DC transformer supplying 1 to 5 amps at 5 to 24 volts D.C. may be used along with a microcontroller to control activation of the chlorinator 11 .
In such embodiments, hydroxyl radicals are generated directly off the electrode plates. The hydroxyl radicals then oxidize organic waste in the process water or react with water and dissolved salts to produce various oxidizers. These include but are not limited to, ozone (O3), hydrogen peroxide (H2O2), sodium hypochlorite (NaHOCl/OCl), chlorine dioxide (ClO2), sodium persulfates (NaHSO5) and sodium percarbonate (Na 2 CO 3 ). This broad spectrum of oxidizers is capable of neutralizing organic and other contaminants which may be present.
A chlorine generator system according to an illustrative embodiment may operate in an open-loop mode using scheduled and timed generation of chlorine. The length and interval of daily generation is typically a function of the spa size, bather load, and water salinity. In such a system, the cell 11 may produce a constant stream of 0.1 to 0.60 ppm (parts per million) chlorine in a 4 gpm flow (0.5-2 amp & 1000-2000 ppm salt). To maintain the chlorine level in the water, the cell 11 must operate longer for a large spa than for a small spa. Additionally the cell 11 must run longer with a higher expected bather load. The salt level has a strong direct relationship to the quantity of chlorine produced.
In an illustrative open loop system the user inputs three variables to the system at start-up. The first is the SPA SIZE or (SPA). A size code may be used (e.g. 1-8). The anticipated USE LEVEL or (USE) (1-5) is the second variable. Use level “(1)” corresponds to minimal use and vacation mode. A higher level should be entered if more bathing is expected. The user preferably adjusts the use level over the course of use. The third start-up variable input is the water hardness (Hd). This parameter controls the polarity reversal cycle timing used to clean the electrodes. This variable may not be employed in alternate embodiments.
As an additional input feature, a manual chlorine addition (Add) or BOOST command may be implemented. This command instructs the system to generate enough chlorine to add 2 ppm to the spa. This chlorine Add temporarily overrides scheduled operation times.
The manual Add or BOOST command dictates that the system run for a length of time sufficient to add 2 ppm Chlorine. The amount of time needed to bring the water to 2 ppm is highly dependent on the amount of bather load in the water. A standard 24 hour dose or longer may be needed to completely bring the water up. In one implementation of the Add or BOOST command, the system switches from 2 amps to 4-4.5 amps to rapidly generate chlorine. One run cycle every six hours may be used to maintain uniform around the clock treatment.
In one embodiment, salt is measured each time the unit 11 generates chlorine as well as when requested by the user. The system measures the salt level of the water by means of measuring the voltage and current across the cell 11 . The voltage reading is then compared against allowable limits. The salt concentration is normalized, and displayed on the user interface. A voltage higher or current lower than specified returns a low salt error and a voltage less or current higher than specified returns a high salt error.
If there is a low salt condition, an error may be sent to the spa controls, triggering a “water care” icon to flash. The unit 11 may be allowed to continue to generate chlorine in this condition. The spa controls or controller modulates available voltage or current to a regulated limit to automatically compensate for low salt or conductivity situations. If there is a high salt condition, an error will be sent to the spa controls, again triggering the water care icon to flash. In this case, the unit 11 will not generate chlorine until the salt level has been corrected.
To prevent mineral scale on the electrodes 53 , 55 , 57 , 59 , polarity reversal may be used. The time period of the reversal is a function of water hardness and is preferably made adjustable to a user input hardness reading. Rapid cycling of the electrodes will cause premature electrode failure. Therefore a dead band in the cycle may be implemented to allow the electrodes to discharge prior to the polarity reversal. The dead band interval may be, for example, a minimum of 10-20 seconds.
At either initial start-up or at a maintenance event, the spa water should be manually balanced. Once the spa water has been balanced it should be super chlorinated (5 ppm). Super chlorination prepares the system for operation and immediate spa usage by cleaning the spa after a period of nonuse. After super chlorination, salt is added to the water. The spa control system may operate such that the water care icon is blinking to indicate that the salt level is low and/or the unit has not been initialized or programmed. Salt should be added slowly into the filter compartment while all of the jets are operating. The jets should operate an additional 10 minutes after the salt is fully added. An example of a target salt concentration is 1000 ppm. High demand users can add up to 2000 ppm salt, which will lower the hours required to generate chlorine and therefore lower the USE level. A salt level reading is preferably taken every time the unit begins a generation cycle to ensure proper salt levels at start-up and during the time between water changes.
Typical operation of an illustrative system preferably requires a weekly chlorine and water quality check to ensure that the system is working correctly. Although the user is not required to enter the chlorine concentration, the value is needed to determine the use level. Over the course of the first month, the user may determine their Use Level by taking a reading of the water before they enter the spa. If the chorine level is low, e.g., “1” or less, the user will want to increase the use level by one to increase the output. If the user finds that the chlorine level is 5 or higher, the user will want to drop the use level by one and retest in a few days or a week. If the bather load is predictable, the use level may only need occasional adjustments.
If the bather load is sporadic, the user may want to perform a manual addition. In such case, the user may enter the spa control menu and confirm an addition (Add or Boost). The addition operation turns the system on immediately and operates the specified amount of time determined to elevate the chlorine level by 2 ppm (this depends on bather load and time and cannot be guaranteed). If the water is overly polluted such that the actual bather load far exceeded the anticipated bather load, a manual dichlor/MPS dose may be used and is compatible with the system.
Typically, the spa will require a monthly manual shock with MPS or dichlor to eliminate any accumulated waste. The oxidizer level should be brought to and held at 5 ppm while all jets configurations and pumps are operated for 30 minutes each. It is important to monitor pH at this time as well to ensure that the water remains balanced.
Over time the water level in spa typically drops from evaporation or splash out. When fresh water is added to the spa, it is important to rebalance the water and monitor the salt concentration. The system may employ a conductivity sensor to determine the amount of salt in the water and whether it is too high or too low. A water care icon may be arranged to blink to indicate that the salt is low and that more salt is needed. Salt should be added in 0.25 lb (100 g) increments to ensure that it is not over dosed.
While the apparatus and method have been described in terms of what are presently considered to be the most practical and preferred embodiments, it is to be understood that the disclosure is not limited to the disclosed embodiments. It is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims.
Those skilled in the art will appreciate that various adaptations and modifications of the just described preferred embodiment can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein. | An oxidizer generating apparatus comprising a cylindrical housing and an electrode assembly attached at one end of the housing comprising at least three vertically disposed electrodes, the electrodes being spaced apart so as to define a water flow path between them, the electrodes comprising titanium outer electrodes and at least one inner diamond electrode. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to multiple function end effector tools, and more particularly, relates to an exchangeable multi-functional tool suitable for use on a robotic end effector disposed on the distal end of a robotic arm.
2. Discussion of the Relevant Art
Automated production lines in use today incorporate automatic machinery and automatic control arms to perform numerous functions. Generally these robotic control arms perform one particular function. With improvements in the state of the art intelligent robots are capable of changing their tools while using end effortor mechanisms disposed on the distal end of the robotic arm. These end effector mechanisms are capable of retrieving and/or exchanging several of these tools so that the arm is capable of more than one function and may be readily programmed to accomplish any number of functions. Generally, however, the tools themselves are capable of performing one type of function such as, grasping an outer diameter, grasping in inner diameter, inserting a screw, applying paint, welding, etc.
Automatic production lines utilizing robots with arms capable of changing tools affixed to the distal end of the robotic arm is generally referred to an end effector, and typical of these, is the apparatus disclosed in copending application Ser. No. 577,570 filed on Feb. 6, 1984. An end effector affixed on the robotic arm used on this type of robot is disclosed in detail in U.S. Pat. No. 4,591,198, issued to Mathew L. Monforte, on May. 27, 1986 (Ser. No. 580,715) filed on Feb. 16, 1984. An end effector tool utilized on the end effector mentioned above is disclosed in detail in application Ser. No. 591,265 filed on Mar. 19, 1984, now abandoned, is capable of a single function.
The exchangeable multi-function end effector tool described herein is a further improvement over the known state of the art since it provides a tool suitable for use with a robotic end effector that is capable of performing multiple functions as will be described in detail hereinafter.
Therefore, it is an object of the present invention to provide an exchangeable multi-function end effector tool that is capable of being received on the extending fingers of an end effector.
It is another object of the present invention to provide a multiple function end effector tool which may be readily captured and released by an end effector disposed on the distal end of a robotic arm.
It is yet another object of the present invention to provide a multi-functioned end effector tool which when captured by the end effector maintains the mechanical integrity of this system.
It is still yet another object of the present invention to provide a multi-functioned end effector tool that may be readily modified to perform alternative multiple functions.
It is still yet another object of the present invention to provide a multi-functioned end effector tool that is readily captured by a robotic end effector while maintaining the mechanical integrity and accuracy of the system.
It is still yet another object of the present invention to provide a multi-functioned end effector tool capable of providing automatic sensing to indicate when the tool has captured an element or component and has placed it in the proper position.
SUMMARY OF THE INVENTION
An exchangeable multiple-function end effector tool suitable for use with a robotic end effector having a pair of extending fingers, including indexing means and computer controlled locking means and disposed on the distal end of a robotic arm, according to principles of the present invention, comprises in combination; an arrangement for removably affixing the multiple-function end effector tool on the extending fingers of the robotic end effector a tool device having an affixing arrangement disposed thereon which includes first and second gripping mechanisms requiring first and second elements and releasably retaining same, provision being made for engaging and disengaging the elements separately or together.
The foregoing and other objects and advantages will appear from the description to follow. In the description reference is made to the accompanying drawing which forms a part hereof, and in which is shown by way of illustration, specific embodiments in which the invention may be practiced. These embodiments will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is best defined by the appended claims.
BRIEF DESCRIPTION OF THE DRAWING
The subject matter which I regard as my invention is particularly pointed out and distinctly claimed in the concluding portion of this specification. The invention, however, both to organization and method of operation, together with further objects and advantages thereof may best be understood by reference to the following description taken in connection with the accompanying drawing, wherein like reference characters refer to like elements and in which:
FIG. 1 is a perspective view, not to scale, of a multi-functional end effector tool affixed to an end effector disposed on the distal end of a robotic arm which is computer controlled, according to the principles of the present invention.
FIG. 2 is a front elevational view of the multi-functional end effector tool shown in FIG. 1;
FIG. 3 is a bottom view of the multi-function end effector tool disclosed in FIGS. 1 and 2;
FIG. 4 is a side view, in elevation, of an alternative embodiment of a multi-functional end effector tool; and
FIG. 5 is a bottom view of the multi-functional end effector tool shown in FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the figures, and in particular to FIGS. 1 and 2, which show a multiple-function end effector tool 10, according to the principles of the present invention. The end effector tool is shown affixed to the extending fingers 12 and 14 emanating from an end effector 11, of the type disclosed in the U.S. Pat. No. 4,591,198 (Ser. No. 580,715) to M. L. Monforte which is incorporated herein by reference, as if set forth at length, and disclosed above. The end effector fingers 12 and 14 are provided with an indexing arrangement in the form of apertures 16, 18, and 20 disposed in finger 12 and apertures 22, 24 and 26 disposed in finger 14, preferably elongated and adapted to receive mating elongated members 16a, 18a, and 20a provided in the generally vertically disposed portions 28 and 30 of the frame 32 of the multiple-function end effector tool 10. The extending fingers 12 and 14 are hollow members having disposed therein computer controlled locking mechanisms 34 and 36 disposed internally in extending fingers 14 and 12, respectively. The details of the indexing arrangement and locking mechanisms 34 are described in the U.S. Pat. No. 4,591,198 (Ser. No. 580,715) to M. L. Monforte mentioned earlier.
The rear portion 38 of the frame 32 is fabricated of a conventional tongue and groove or cooperating U-channel arrangement wherein the tongue portion 40 is affixed to the vertical portion 28 of frame 32 and is permitted to freely slide within the groove or channel 42 provided in the vertical portion 28 of the frame 32. The tongue and groove portions preferably being disposed in a horizontal place, capable of free movement therebetween, thus permitting the vertical portions 28 and 30 to move in a horizontal plane and permitting the lower portions 44 and 46 extending from portions 28 and 30, respectively, to move in a horizontal direction towards and away from each other; the reasons therefor will become apparent shortly. Thus, movement of the fingers 12 and 14 coupled to the end effector 11, disclosed in U.S. Pat. No. 4,591,198 (Ser. No. 580,715), will permit the lower portions 44 and 46 to engage and disengage an object, element or component, which will be explained hereinafter.
The groove or channel 42 is provided with an upper lip portion 48 and a lower lip portion 50. The electronic circuitry 52, integrated or otherwise, is contained in a housing 54 which is affixed to the upper lip portion 48 in a conventional manner. The electronic circuitry is coupled to the main control computer 51 and robotic arm 53, not shown, via cable harness 55 and 56 connected thereto.
A shelf portion 58 (see FIG. 3) has one end thereof affixed to lower lip portion 50 by means of a pair of screws 60 and 62 being inserted through cooperating apertures 64 and 66 respectively, adapted to cooperate therewith. Apertures 64 and 66 are preferably slightly elongated to allow for the alignment of the spring loaded suction cup 68 which extends therethrough as will be explained hereinafter.
The suction cup 68 includes a suction portion 70 disposed on one end of a hollow rod 72. The suction portion may be fabricated of a resilient material, such as rubber or any other plastic material. The rod includes a central aperture 74 which extends completely therethrough having one end thereof terminating at the suction portion 70 and the other end having a nipple thereon suitable for connection, via a flexible hose 76, to a vacuum system, not shown through a control valve activated by the main computer system, not shown. An aperture provided in the shelf portion 58 is provided with an Oilite bearing 78, that permits relatively friction free movement of the rod 72 through the aperture 78 while maintaining the alignment thereof. A spring member 82 circumscribes the rod 72 and is disposed between a collar 84 used to hold the suction portion 70 onto rod 72 and the bearing 80, thus urging the suction portion 70 of the spring loaded vacuum suction cup 68 away from the shelf portion 58 in the direction of arrow 86. The suction portion 70 extends beyond the lower portions 44 and 46 so that it may readily engage a flat surface 88 provided on a disk member 90. The upper portion of hollow rod 72 is provided with a second collar 92 which serves two functions; one being to limit the travel of the rod 72 in the direction of arrow 86 and the second, as will be explained later, will indicate the position of the spring loaded vacuum suction cup 68. Proximate the upper distal end of rod 72 a tapered collar 94 is affixed in conventional manner. Hereagain, the function thereof will be explained hereinafter.
The inner surface of vertical portions 28 and 30 are provided with inwardly extending members 96, 98, 100 and 102, respectively, which have mounted therebetween roller bearings 104 and 106, respectively. Inwardly extending members 96, 98, 100 and 102 are disposed on vertical portions 28 and 30 directly in line with each other and the roller bearings 104 and 106 are positioned to come into contact with the sloped surface of collar 94. Thus when roller bearings 104 and 106 are urged into contact with collar 94 they will cause collar 94 to rise in an upwardly direction (in the direction of arrow 108) moving rod 72 in an upwardly direction raising the suction portion 70 upwardly into the open portion 110 of the end effector tool 10. The most inwardly extending edges of members 96, 98, 100 and 102 function as limit stops and prevent the extending fingers 12 and 14 from closing the multiple-function end effector tool 10 beyond the predetermined limits.
A circuit board 110 is disposed on the forward edge of shelf portion 58 and has mounted thereon a pair of light emitting diodes (LED's) 112 and 114 which are connected, via wires 116, to the housing for the electronic circuitry 54. A pair of photoelectric detectors 118 and 120 are mounted on a printed circuit board 122 disposed on shelf portion 58 on the other side of the collars 94 and 92 with the light beams emanating from diodes 112 and 114 impinging directly upon the cooperating detectors 118 and 120, so that when collar member 92 is raised to the first level the light emitted from LED 112 will be blocked thereby, and when the collar reaches the second level the light emitted from LED 114 will be blocked thereby, thus breaking the light path from light emitting diodes 112 and 114 to photoelectric detectors 118 and 120, respectively. Thus, the interruption of the light paths (sensing device) will provide a signal to the main computer, not shown, indicating when the suction portion 70 has reached the proper level permitting further closing of the fingers 12 and 14 so that the lower portions 44 and 46 may readily engage a second component or member 124 within the channels 126 and 128 provided in lower portions 44 and 46, respectively.
Referring now to FIGS. 4 and 5, which disclose an alternative embodiment of the instant invention. The extending fingers 12 and 13 of a robotic end effector, not shown may engage the extending protrusions 130, 132, and 134 provided on the top 136 of housing 138 and protrusions 140, 142 and 144 provided on the bottom 146 of housing 136 thereby enabling the multi-function tool 148 to move to a desired location. In this embodiment a dual vacuum system is incorporated. The inner and outer vacuum systems are separately controlled by the computer and control valves, not shown, which are coupled, via flexible hoses 150 and 152, to the spring loaded vacuum suction cup 154 which is disposed in the center and suction cups 156, 158 and 160 which are equally spaced and disposed about the periphery of an imaginary circle so they may readily pick up a generally flat disk-shaped member 162 having its center removed. The centrally disposed suction cup 154 may readily engage a component 164, which has a generally flat surface and a central portion accessible to the centrally disposed suction cup 154.
Suction cup members 156, 158 and 160 are similar in construction to the spring loaded vacuum suction cup 68 described in the earlier embodiment and may be utilized to engage component 162 from a holding fixture by moving the robotic end effector into position. Once the vacuum has been activated in flexible hose line 150 component 162 will be affixed to suction cups 156, 158 and 160 and movement of the robotic end effector towards component 164 be readily accomplished.
For example, the embodiment shown in FIGS. 4 and 5 may operate by having component 164 placed in a holding fixture with a solder ring 166 disposed proximate the circumference thereof. The central suction cup may be provided with a generally longer throw position so that its construction, although being similar to the spring loaded vacuum suction cup 68 described in conjunction with the prior embodiment, may be adjusted to permit extension beyond the edges of suction cups 156, 158 and 160, thereby enabling it to engage component 164 in the center thereof. Once the vacuum has been created, component 164 will adhere to the suction cup 154.
Once components 162 and 164 have been affixed to the multi-function tool, which may be moved to a washing operation or flux bath and then pressed against the flat surface wherein components 162 and 164 come into contact with each other with the soldering sandwiched therebetween. Thus, the assembly may now be subjected to a heating operation, such as ultra-sonic welding, where the solder causes the components to be soldered together. Releasing of the vacuum permits the new assembly to be removed from the multi-function tool 148. Those knowledgeable in the art may utilize this type of multi-function device to perform a variety of different functions.
The first embodiment, in operation, utilizes the same capturing method for obtaining a component 90 and by movement of the end effector fingers 12 and 14 causes the object 90 to rise within the fixture, thus permitting the lower portions 44 and 46 of the multi-function tool to engage a second component 124 within the channels 126 and 128 provided in lower portions 44 and 46, respectively. With this type of multi-function tool the components may be subjected to another operation such as cleansing, and be released simultaneously or individually since component 124 may readily be released by moving fingers 12 and 14 in an outwardly direction, while component 90 may be retained by the spring loaded vacuum suction cup 68 as long as the vacuum remains intact. The vacuum being intact, after contacting a component, clearly indicates the acquisition of a component and this provides a signal to the central computer, in a conventional manner, after a prescribed period of time.
Hereinbefore has been disclosed a multiple-function end effector tool suitable for use with robotic end effectors. The utilization of multi-function tools is limitless and the imagination of those knowledgeable in the art can envision an infinite number of variations in these basic components. Therefore, it will be understood that various changes in the details, materials, arrangement of parts and operating conditions which have been hereinbefore described and illustrated in order to explain the nature of the invention may be made by those skilled in the art within the principles and scope of the present invention. | An exchangeable multiple function end effector tool suitable for use on the distal end of a robotic end effector includes, in combination; a device for removably affixing the multiple function and effector tool onto a pair of extending fingers provided on a robotic end effector. The multiple function tool is provided with an apparatus for acquiring a first element or component and releasably retaining same and further incorporates a second gripping device which is capable of acquiring a second element or component and releasably retaining same in the tool. Provision is made for engaging and disengaging the elements either separately or in unison. Movement, assembly or disassembly of the elements remains a function of the end effector and its control mechanisms. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to a shift control mechanism for an automatic transmission for a motor vehicle and more particularly to a shift interlock mechanism to preclude undesired or inadvertent shifting of the transmission.
The shift control mechanism for an automatic transmission is typically capable of placing the transmission in either a park mode or various non-park modes by manual actuation of a shift lever. The non-park modes typically include reverse, neutral, and two or more drive positions. The shift control mechanism typically includes a detent mechanism which coacts with the shift lever to define each shift position and impede inadvertent movement of the shift lever out of any given shift position.
Most automatic transmissions also include some provision for locking the shift lever in the park detent position while the ignition switch is in the off position as an aid to theft prevention. Most automatic transmissions further include a brake shift interlock whereby the shift lever inhibited from being moved out of the park detent position unless and until the service brakes of the vehicle are applied. This precludes undesired acceleration of the vehicle resulting from inadvertent movement of the shift lever from the park to a drive or reverse position.
It is important that the ignition/switch interlock and the brake/switch interlock be provided in a cost effective manner.
SUMMARY OF THE INVENTION
This invention is directed to the provision of an improved transmission shift interlock mechanism for use on a vehicle having an automatic transmission.
More specifically, this invention is directed to the provision of a transmission shift interlock mechanism that is cost effective.
This invention is further directed to the provision of an improved holding device that is especially suitable for use in a transmission shift interlock mechanism.
The holding device according to the invention comprises a housing; an annular electromagnet positioned within the housing and having a central passage therethrough; an annular armature formed of a thermomagnetic material and having a central aperture; an elongated tubular stem formed of a non-magnetic material, having a reduced diameter as compared to the armature, centrally secured at one end thereof to the armature with the central passage of the stem coaxial with the aperture of the armature, and positioned slidably in the central passage of the electromagnet with the annular outer portion of the armature radially outwardly of the stem positioned proximate a rear annular face of the electromagnet and the free end of the stem extending forwardly beyond a front annular face of the electromagnet and defining an abutment surface; a cable extending slidably through the armature aperture and through the tubular stem; and abutment means on the cable defining an abutment surface rigid with the cable proximate the stem abutment surface. With this arrangement, and with the electromagnet deenergized, the cable is free to move in either axial direction relative to the housing by axial sliding movement within the stem but, with the electromagnet energized and the annular outer portion of the armature held magnetically against the rear annular face of the electromagnet, the cable is free to move axially forwardly relative to the housing by axial sliding movement within the stem but is precluded from moving axially rearwardly relative to the housing by engagement of the abutment surfaces and the magnetic attraction of the armature to the electromagnet. The use of a separate abutment surface on the cable for coaction with the abutment surface defined on the stem facilitates assembly of the holding device and specifically allows successful and reliable operation of the holding device over a wide range of assembly and part dimension tolerances.
According to a further feature of the invention, the holding device is utilized to provide the brake/shift interlock for a transmission shift interlock system wherein the ignition shift interlock is provided by a cable extending between the ignition switch and a park/lock member and the invention holding device is piggy-backed on the cable so that the holding device cable is constituted by the ignition shift interlock cable.
In the disclosed embodiment of the invention, the invention holding device is utilized as the brake/shift interlock of a steering column mounted shift control mechanism and provides a compact, reliable, efficient shift interlock mechanism especially suitable for use in a steering column shift environment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective somewhat schematic view of a transmission shift interlock according to the invention shown in association with a vehicular steering column;
FIG. 2 is a somewhat diagrammatic view of the invention transmission shift interlock;
FIG. 3 is a cross-sectional view taken on line 3--3 of FIG. 2;
FIG. 4 is a detail view of a portion of the shift interlock;
FIGS. 5 and 6 are detail perspective views of portions of the shift lever mechanism; and
FIG. 7 is a generalized circuit diagram showing the electrical operation of the invention shift interlock.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention shift interlock is seen in FIG. 1 in association with a motor vehicle, such for example as an automobile, including an engine 10, an automatic transmission 12, a drive shaft 14, a steering column 16 including a steering shaft 18 associated with a steering wheel 20, a service brake 22, a shift control mechanism 24, and an ignition switch assembly 26.
Shift control mechanism 24 (FIGS. 1, 4 and 5) includes a mounting bracket 28, a detent plate 30, a shift lever 32, a clevis 33, a crank arm 34, a bell crank 36, and a connecting rod 38.
Mounting bracket 28 is fixedly secured to steering column 16 in underlying relation to steering wheel 20.
Detent plate 30 (see also FIG. 4) may be mounted on bracket 28 or may be secured directly to steering column 16. Plate 30 has a generally arcuate configuration, and defines a plurality of detent notches to define the various transmission shift positions or modes including a park mode detent notch 30a and a plurality of further detent notches 30b defining the further transmission modes.
Shift lever 32 includes an outboard handle portion 32a for access by the vehicle operator, a shaft portion 32b, a pivot portion 32c, and an inboard detent portion defining a detent 32d. Pivot portion 32c is positioned between the upper and lower arms of clevis 33 so as to mount the lever 32 for pivotal movement about a pivot shaft 40 extending between the upper and lower arms of the clevis.
Crank arm 34 is secured to the free end of a pivot shaft 42. Pivot shaft 42 extends at right angles from clevis 33 and is journaled in a journal portion 28b of bracket 28. Shift lever 32 and crank arm 34 may thus be pivoted in unison about the pivot axis defined by pivot shaft 42.
Bell crank 36 is mounted for pivotal movement on a shaft 44 carried by bracket 28 and includes an input arm 36a and an output arm 36b. Input arm 36a includes an elongated slot 36c slidably receiving a ball 34a fixedly mounted on the free end of crank arm 34.
Connecting rod 38 is secured to the free end of bell crank output arm 36b by a pin 46 and is connected in known manner to a conventional mode select lever 48 of the automatic transmission 12.
Pivotal movement of shift lever 32 about pin 40 moves detent 32d in and out of engagement with detent notches 30a, 30b and pivotal movement of arm 32 about the axis of pivot shaft 42 moves the transmission, via arm 34, crank 36, and rod 38, between its various modes with detent 32d moving into successive alignment with respective detent notches corresponding to the respective transmission modes.
Ignition switch assembly 26 includes an ignition switch 50, a switch housing 51, and a switch interlock member 52 (FIG. 2) positioned within housing 51. Switch assembly 26 is mounted on steering column 16 between the steering wheel and the shift control mechanism 24. Switch 50 is arranged for rotary movement, in response to insertion of the proper key, between a plurality of positions including an off position and a run position with the ignition switch interlock 52 moving with the tumbler mechanism of the ignition switch to selectively alter the angular position of a lobe 52a defined by the switch interlock member.
In accordance with the invention, an ignition shift interlock mechanism 54 is provided and a brake shift interlock mechanism 56 is further provided.
Ignition/shift interlock 54 is operative to preclude movement of the transmission out of the park position unless and until the ignition switch is moved to a run position, and brake/shift interlock 56 is operative to preclude movement of the transmission out of the park position unless and until the service brakes are applied.
ignition/shift interlock 54 includes a cable assembly 58 and a park/lock member 61.
Cable assembly 58 includes a cable 60, a sheath 62 slidably encasing the cable, an end fitting 64 connected to the rear end of the cable, and a connector 66 connected to the front end of the cable.
End fitting 64 (FIG. 2) includes a bore 64a receiving the rear end 62a of sheath 62, a bore 64b for slidable passage of cable 60, a counterbore 64c, a further counterbore 64d, and a bayonet fitting 64e. A pin 68 is slidably received in counterbore 64d and is fixedly secured to the rear end 60a of cable 60, and a coil spring 70 received in counterbore 64c urges pin 68 and thereby cable 60 rearwardly or to the left as viewed in FIG. 2. Bayonet fitting 64e is utilized to readily mount the fitting 64 to the housing 51 of the ignition switch assembly with pin 68 urged via spring 70 into engagement with the outer periphery of ignition switch interlock member 52.
Connector 66 has a Z configuration and includes a rear portion 66a fixedly secured to the front end 60b of cable 60, a front portion 66b, and a interconnecting crank portion 66c.
Park/lock member 61 (FIGS. 1 and 4) is in the form of a lever mounted for pivotal movement at one end thereof about a pivot pin 72 mounted, for example, on detent plate 30. Park/lock member 61 includes an interlock structure at its other or free end for coaction with detent 32d. The interlock structure on the park/lock member includes a leading finger portion 61a and a follower finger portion 61b coacting with portion 61a to define a slot 61c. Park/lock member 61 further includes an intermediate aperture 61d receiving the crank portion 66a of connector 66 whereby to pivotally connect the forward end of cable 60 to the park/lock member.
With reference to FIG. 4, it will be seen that after detent 32d has been moved out of park detent slot 30a and into slot 61c by pivotal movement of shift lever 32 about pin 40, any attempt to thereafter move the detent about the axis of pin 42 to another transmission mode will be blocked by finger portion 61a of park/lock lever 61 to the extent that pivotal movement of the park/lock lever about pivot pin 72 is precluded. Pivotal movement of park/lock member 61 about pin 72 is precluded by the engagement of pin 68 (FIG. 2) with lobe 52a of ignition switch interlock member 52 in so long as the ignition switch is in an off position. When the ignition switch is moved to an on position, the ignition switch interlock member moves to a position where a recess portion 52b of the interlock member is in confronting relation with pin 68 and the pin and thereby the cable is free to move rearwardly or to the left, as viewed in FIG. 2, by an amount equal to the difference in the radius's of lobe 52a and recess 52b. The various system springs and resistances are preferably chosen so that the cable does not move immediately rearwardly or to the left upon movement of the ignition switch to the run position but, rather, the system force balances are such that after detent 32d has been moved out of the park notch 30a by pivotal movement of shift lever 32 about pin 40, the subsequent movement of the detent about the axis of pivot shaft 42 has the effect of engaging the forward finger portion 61a of the park/lock lever and pushing the park/lock lever out of the way by pivotal movement about shaft 72, to allow the detent and the shift lever to move to a new shift mode position. The described ignition/shift interlock will thus be seen to preclude movement of the transmission out of park unless and until the ignition switch is moved to a run position.
Brake/shift interlock 56 comprises an electromagnetic holding device piggy-backed on the ignition/shift interlock, and specifically, piggy-backed on the cable 60 of the ignition/shift interlock.
Brake/shift interlock 56 (FIG. 2) includes a housing assembly 74, an electromagnet assembly 76, an armature assembly 78, and a stop button 80.
Housing assembly 74 includes a mounting bracket 82, a front cylindrical housing 84, a rear cylindrical housing 86, and a rear connector 88. Bracket 82 includes a rear tubular portion 82a swivelly mounted in a counterbore 84a in the forward end of housing 84 by a swivel connection 90 and further includes a plate-like forward mounting portion 82a defining a mounting aperture 82b. Rear housing 86 is cylindrical and is swivelly connected to front housing 84 via a swivel joint 92. Rear connector 88 is swivelly mounted at 94 in a rear hub portion 86a of rear housing 86.
Electromagnet assembly 76 includes a bobbin or canister 96 and a coil 98.
Canister or bobbin 96 is positioned forwardly in housing 84 and includes inner 96a and outer 96b concentric cylindrical walls defining an annular space 96c therebetween.
Coil 98 comprises electrically conductive wire wound in known manner around canister inner wall 96a and occupying annular space 96c. The inner and outer walls of the canister are connected by a front wall 96d but the annular space 96c is open rearwardly.
Armature assembly 78 includes an annular disk shaped armature 100 formed of a ferromagnetic material and a tubular stem 102 formed of a non-magnetic material.
Stem 102 has a reduced diameter as compared to the diameter of the armature, and is centrally secured at its rear end, as by staking 102d, to the armature with the central passage 102a of the stem coaxial with a central aperture 100a in the armature. Stem 102 is positioned slidably in the central passage 104 defined by the inner wall 96a of the canister with the annular outer portion 100b of the armature, radially outwardly of the stem, positioned proximate the rear annular face of coil 98 and the stem extending forwardly beyond the front wall 96d of the canister and through a bore 84b in housing 84 to position the free forward end 102b of the stem within tubular portion 82a of bracket 82 and define an annular abutment surface 102c at its forward edge.
A cavity 106 is defined rearwardly of the armature assembly within the housing assembly and a coil spring 108 is positioned in cavity 106 and biases armature 100 forwardly toward coil 98.
Stop button 80 is in the form of an annular collar crimped to cable 60 forwardly of but proximate abutment surface 102c and defining a rearward abutment surface 80a for coaction with abutment surface 102c. Abutment surfaces 102c and 80a may be separated, for example, by a distance of 1 millimeter.
In the assembled relation of the brake/shift interlock, aperture 82b in bracket 82 is mounted on pivot shaft 72 and the front end 62 of sheath 62 is received in connector 88 with cable 60 passing centrally through the electrical magnetic assembly and specifically passing slidably through the central passage 102a of the tubular stem 102 for connection to connector 66.
Leads 110 and 112 connect to opposite ends of coil 98 as seen in FIGS. 2 and 7. With continued reference to FIG. 7, the generalized schematic diagram shown therein includes a positive battery terminal, ignition switch 50, a fuse 114, lead 110, coil 98, lead 112, and a lead 116 extending to a junction 118. Junction 118 connects to a center high mount brake stop lamp 120 and also connects via a lead 122 to a normally open brake switch 124 which is connected to the negative battery terminal by a lead 126 passing through a fuse 127. Left and right stop lamps 128, 130 are also connected to junction 118 through a multi-function switch block 132 of known configuration. Preferably one or more diodes (not shown) are included in the electrical circuit of the holding device so as to assure proper polarization of the device and to prevent the propagation of inductive noise or other transients through circuitry attached thereto. Various configurations of diodes may be employed to achieve polarity protection and/or switching and/or noise suppression.
When the ignition switch is moved to a run position, battery voltage is fed to the coil 98 and the coil is energized by completion of a path through any of the brake lights 120, 128 or 130, which do not illuminate since a minimal amount of current is drawn by the coil. The energized coil magnetically pulls the armature 100 against the rear or left side of the coil, as viewed in FIG. 2, so that any attempted movement of cable 60 in the rearward or left direction is precluded by the attraction of the armature to the coil and the immediate abutting engagement of the abutment surfaces 102c and 80a. When the brake pedal 22 is depressed, and the brake switch 124 is thereby actuated to its closed position, battery potential is placed on the brake light circuit at juncture 118 which also places that same potential on terminal 112 of the coil. Since substantially the same potential now appears on both terminals of the coil, the coil will be deenergized thereby releasing the armature 100 and allowing cable 60 to move rearwardly.
It will be seen, therefore, that shift lever 32 cannot be moved out of the park position unless and until the ignition switch has been moved to a run position and the brake pedal has been applied. Specifically, as the ignition switch is moved to the run position, the coil is energized as seen in FIG. 7 to attract the armature and preclude rearward or leftward movement of the cable even though the cable is otherwise free to move rearward by virtue of movement of the ignition switch to its run position. When the brake pedal is thereafter applied, the coil is deenergized, the armature 100 is released, and the cable 60 is now free to move rearwardly under the urging of the shift lever and, specifically, under the urging of detent 32d against the forward finger portion 61a of park/lock member 61.
The electromagnetic holding device 56, as compared to prior art electromagnet holding devices, has the advantage of allowing greater tolerance with respect to manufacturing procedures and with respect to part dimensions. Specifically, it is critical that the armature 100 define a specific gap between the armature and the coil in order for the coil and armature to develop sufficient attractive force to preclude leftward or rearward movement of the cable. In the invention arrangement, the armature is free to seek this ideal gap position by virtue of the sliding relationship between the cable and the tubular stem 102, as compared to a construction in which the tubular stem is crimped or otherwise attached to the cable.
Whereas a preferred embodiment of the invention has been illustrated and described in detail, it will be apparent that various changes may be made in the disclosed embodiment without deploring the scope or spirit of the invention. | A holding device and a transmission shift interlock mechanism employing the holding device. The holding device is intended to immobilize a cable and includes a generally cylindrical electromagnet with a central passageway extending therethrough and a holding assembly comprised of a ferromagnetic body joined to a tubular non-magnetic stem. The ferromagnetic body and stem have a passageway therethrough and the stem passes through the central passageway of the electromagnet. The cable passes slidably through the stem and a stop collar is secured to the cable immediately forwardly of the stem for abutting coaction with the forward end of the stem. In the transmission shift interlock mechanism, the cable extends from an ignition switch interlock member to a park/lock member pivotally mounted beneath the steering column of the vehicle and acting in the locked position thereof to preclude movement of the shift lever detent from the park detent position to a drive or reverse detent position of the vehicle automatic transmission. The holding device is piggy-backed on the cable proximate the park/lock lever and includes a mounting bracket securing the holding device proximate the park/lock member. | 7 |
FIELD OF THE INVENTION
This invention addresses the need for improved core balance throughput, and accomplishes this by designing a special centering geometry interface.
BACKGROUND OF THE INVENTION
Turbochargers are a type of forced induction system. They deliver air, at greater density than would be possible in the normally aspirated configuration, to the engine intake, allowing more fuel to be combusted, thus boosting the engine's horsepower without significantly increasing engine weight. This can enable the use of a smaller turbocharged engine, replacing a normally aspirated engine of a larger physical size, thus reducing the mass and aerodynamic frontal area of the vehicle.
Turbochargers ( FIGS. 1 and 2 ) use the exhaust flow, which enters the turbine housing ( 2 ) from the engine exhaust manifold to drive a turbine wheel ( 51 ), which is located in the turbine housing. The turbine wheel is solidly affixed to the turbine end of a shaft, becoming the shaft and wheel assembly ( 50 ). A compressor wheel ( 20 ) is mounted the other end of the threaded shaft, referred to as the “stub shaft” ( 56 ), and the wheel is held in position by the clamp load from a compressor nut ( 30 ). The primary function of the turbine wheel is providing rotational power to drive the compressor.
The compressor stage consists of a wheel ( 20 ) and it's housing ( 10 ). Filtered air is drawn axially into the inlet of the compressor cover by the rotation of the compressor wheel ( 20 ). The power generated by the turbine stage to the shaft and wheel drives the compressor wheel to produce a combination of static pressure with some residual kinetic energy and heat. The pressurized gas exits the compressor cover through the compressor discharge and is delivered, usually via an intercooler, to the engine intake.
In one aspect of compressor stage performance, the efficiency of the compressor stage is influenced by the clearances between the compressor wheel contour ( 28 ) and the matching contour ( 13 ) in the compressor cover. The closer the compressor wheel contour is to the compressor cover contour, the higher the efficiency of the stage. In a typical compressor stage with a 76 mm compressor wheel, the tip clearance is in the regime of from 0.31 mm to 0.38 mm. The closer the wheel is to the cover, the higher the chance of a compressor wheel rub, so there has to exist a compromise between improving efficiency and improving durability.
The wheels in a compressor stage do not rotate about the geometric axis of the turbocharger, but rather describe orbits roughly about the geometric center as seen in FIG. 3 . The “geometric center” ( 35 ) is the geometric axis of the turbocharger. The compressor end, with data taken from a cylindrical nut of the turbocharger, describes a series of orbits ( 81 ), which are grouped as larger orbits ( 83 ) for the purposes of evaluating the shaft motion of the rotor group.
The dynamic excursions taken by the shaft are attributed to a number of factors including: the unbalance of the rotating assembly, the excitation of the pedestal (i.e., the engine and exhaust manifold), and the low speed excitation from the vehicle's interface with the ground.
As a dynamic assembly, the rotating assembly passes through several critical speeds. At the first critical speed, the critical mode is rigid body bending. In this mode, the rotating assembly describes a cylinder. At the second critical speed, the critical mode is again that of a rigid body, but in the conical mode about the outer ends of the bearing span. At the third critical speed the critical mode is that of shaft bending. The third critical speed occurs at from 50% to 70% of the operational speed. The first two critical speeds are much lower than that and are passed through very quickly during accelerations.
The first two modes are predominantly controlled by the bearing stiffness. The third mode, that of shaft bending, is predominately controlled by the stiffness of the shaft. The stiffness of the shaft is proportional to D s 4 where D s is the diameter of the shaft.
The power losses due to the bearing system are predominantly controlled by D s 3 . So it can be seen that the control of the third critical mode is a compromise between power losses, thus efficiency and shaft bending. When there is an unbalance force, acting on the rotating assembly at the compressor-end of the turbocharger, the stiffness of the shaft is a major factor in countering that force and also in allowing the turbocharger to continue to run after a compressor wheel rubs against its cover.
After a loss of oil pressure or oil flow to any of the journal or thrust bearings, the predominant ultimate cause of turbocharger failure is contact between a wheel and cover. This contact can be as mild as a rub of the rotating wheel on the cover, or an impact of the wheel on the cover. To minimize the risk of this contact, the manufacturer takes many steps to build dynamic integrity into the rotating components.
In a mid-sized, commercial Diesel turbo, for example, with a 76 mm compressor wheel, the shaft and wheel ( 50 ), seen in FIG. 2 , which is recognized as the welded assembly of the turbine wheel ( 51 ) to the shaft, is balanced in two planes, the nose ( 89 ) and the backface ( 88 ). Since the shaft and wheel is finished as a very accurately machined, single component, with shaft diameters ground to tolerances in the tenth of a thousandth of an inch regime (2.54 microns), its inherent balance is quite good. In addition to these tightly held diametral tolerances, the diameters which support the journal bearings ( 70 ) on the large diameter end ( 52 ) of the shaft, and the stub shaft ( 56 ), upon which the compressor wheel and small parts are both axially and radially located, are held to a complex cylindricity tolerance measured in the regime of tenths of a micron.
The shaft and wheel component for the turbocharger size above is balanced within a range of 0.4 to 0.6 gm-mm. The next components in the rotating assembly are the thrust washer and flinger. Both components are ground steel and of relatively small diameter when compared to a wheel. The thrust collar has a mass of around 10.5 gm; the flinger has a mass of around 13.3 gm. Because they are totally circular and have a high degree of finish, these components have very close to perfect balance. The next component is the compressor wheel, which has a mass of around 199 gm.
The compressor wheel is an extremely difficult part to machine and balance. While it is ultimately balanced to a range of from 0.04 to 0.2 gm-mm in each plane, getting down to that limit is difficult. FIG. 4 shows a compressor wheel casting ( 15 ), FIG. 5 shows the same casting machined. The chucking lug ( 16 ) on top of the nose is used to locate the wheel for the first machining operation, which sets the machining of the backface ( 22 ); the lower mounting face ( 22 ); the OD ( 33 ) of the wheel; and the bore ( 27 ) in the center of the wheel. It is extremely critical to machine the bore ( 27 ) in the center of the wheel such that it is centered on the hub at both the nose end ( 21 ) and the hub end ( 22 ). This means that the majority of the mass of the machined wheel is centered on the bore ( 27 ) of the compressor wheel. The act of centering the as-yet un-machined casting on the imaginary turbocharger centerline ( 35 ) also results in blades of equal length which further contributes to the balance of the component. If the wheel is not chucked exactly on center with the hub profile, the machining of the blade contour surfaces ( 28 ) off center (of the hub) results in blades of different lengths. Blades of unequal length can cause not only balance and blade frequency problems, but also once-per-revolution unwanted acoustic problems.
In the next chucking operation on the OD of the wheel ( 33 ) the top of the nose of the compressor wheel is machined flat so that this surface ( 21 ) is flat and parallel to the lower mounting surface ( 22 ), and perpendicular to the bore ( 27 ). Because the surface ( 21 ) on the nose of the compressor wheel is machined in a second chucking, it is difficult to develop the parallelism required with the lower mounting surface. This parallelism is critical from the aspect of maintaining the stub shaft cylindricity with the bearing journal zone ( 52 ). The reason it is critical is to ensure that, when clamp load is applied to this flat surface on top of the nose of the compressor wheel, the clamping forces are parallel to the shaft and wheel centerline, as defined by the cylindricity of the journal bearing surfaces ( 52 ) and the stub shaft mounting surfaces. This shaft and wheel centerline must then be parallel to, and co-incident to, the turbocharger axis for the assembly to have acceptable core balance.
The compressor nut should not be referred to as a nut in the normal sense of the term. The function of the compressor nut is to apply sufficient clamp load to the compressor wheel such that it will not rotate under any dynamic conditions from max speed from cold start to hot shutdown at max speed.
While the nut is a relatively low mass item, at 6.3 gm in the turbo under discussion, its contribution to unbalance (as against balance) can be very large. A requirement of the nut is that the lower face, the face in contact with the face ( 21 ) on the nose of the compressor wheel, must be manufactured to a very tight perpendicularity tolerance to the bore of the thread in the compressor nut, in the range of 0.03 to 0.04 mm, so that when the nut is threaded onto the shaft and clamp load applied, the aforementioned lower face of the nut is applying a load close to normal to the face ( 21 ) on the nose of the compressor wheel. Failure to apply this load symmetrically, either normal to the face of the compressor wheel, or parallel to the shaft centerline ( 35 ), will cause bending of the shaft, with the result that the mass of the compressor wheel, nut, and stub shaft will be displaced from the turbocharger axis ( 35 ) causing a large unbalance in the rotating assembly. Since the nut is extremely difficult to assemble exactly on axis, the mass of the nut is a critical factor in the level of unbalance the bearing system can tolerate. For the same degree of unbalance in the core, the lower the mass of the nut, the higher the geometric run-out acceptable tolerance. Much effort goes into the design of the top end of the compressor wheel, the nut ( 30 ), and the amount of thread ( 57 ) visible above the nut to keep the mass in this zone to a minimum. If the nut is not perpendicular to the top of the compressor wheel, and parallel to the stub shaft below the nut, then the threaded part of the stub shaft, above the nut (i.e., with thread no longer engaged with the thread on the stub shaft), will also be off-center with the centerline of the stub shaft below the nut, and ultimately, off-center with the turbocharger axis, thus contributing to even greater core unbalance.
At the point of manufacturing, all of these critically balanced items are assembled and the core balanced, that is, the balance of the rotating assembly, assembled to the bearing housing, supported by the journal bearings, is spun at high speed with oil pressure supplied to support the rotating shaft on its designed oil film. This procedure checks the balance of the rotating “core”. If the balance is within limits, then the core is satisfactory and is released for assembly into a complete turbocharger. If the balance is out of limit, then the core undergoes a procedure to bring the balance into limits before it is assembled into the housings to produce a turbocharger.
Accordingly, when the turbocharger leaves the factory, the rotating core is within a balance limit, and the turbocharger could be expected to live for several engine rebuild periods.
In the period the turbocharger is operating on the engine, the balance of the rotating core can be degraded in many ways, some of which are listed here: the turbine wheel is subjected to damage from particles, sometimes quite large, from the combustion chamber and exhaust manifold, which causes damage ranging from bending to breaking off of parts of the blades, which then causes a deviation from the factory balance condition; the compressor wheel also can be subjected to damage inflicted by “foreign objects” which are ingested into the system. Loss of oil pressure for a period can cause loss of support of the rotating assembly, which can result in a wheel rub on either, or both wheels, which, at minimum, can cause the removal of some blade material (by rubbing on the housing), which then alters the mass of several adjacent blades, or in a heavier rub can bend the blades. Both of these resultants will cause a change in the balance of the rotating assembly.
If the rotating assembly does develop an unbalance condition less than those discussed above, a resultant of the core unbalance can be the generation of acoustic abnormalities at a once per revolution frequency. With a turbocharger rotating at 150,000 RPM to 300,000 RPM, an unbalance-related acoustical event will be in the frequency range of 2,500 to 5,000 Hertz, which makes the frequency somewhere around the highest frequency producible by a flute (2093 Hz) and the highest producible by a piano, (4186 Hz). So the customers do complain about the audible noise.
A measure of the efficacy of a turbocharger bearing system is the ability of the bearing system to control and support the rotating assembly under all conditions. Turbocharger bearing systems come in many designs from ball bearings for very large and some high performance turbochargers, to different configurations of fixed sleeve bearings, floating oil film bearings, air bearings. They all have one thing in common, and that is the need for fine balance control of the rotating assembly.
The level of balance for the individual components is generated, to some extent, by the level of balance acceptable by the bearing system in the rotating assembly. An automotive type, oil pressure fed, well designed bearing system will present to a manufacturer a maximum unbalance which the bearing system can control and will provide sufficient damping that it remains in control of the shaft excursions under all conditions. This means that any balance condition lower than the maximum unbalance condition acceptable for that bearing system, on a specific engine, is acceptable from an engineering point of view. The cost to achieve this level of core unbalance increases as the level of acceptable unbalance decreases. In the experience of the inventor, some turbocharger cores pass through the core balance “gate” with no additional attention. Some cores need attention, which can be as little as undoing the compressor nut, rotating some components, re-applying the clamp load and then re-testing, to replacing components in the rotating core.
The goal of a turbocharger manufacturer is to offer product at the lowest cost with the highest possible reliability and durability. Balance is a key factor in the durability and reliability drivers. So it can be seen that there is a general need to present cores to the core test device which fall well inside the unbalance lower limit to both decrease assembly costs and increase turbocharger life.
SUMMARY OF THE INVENTION
The above objects were accomplished, and the present invention achieved, by the development of a self-centering geometry between the top of the compressor wheel and the lower face of the compressor nut to align these two components to the turbocharger axis and thus reduce the potential unbalance of the rotating core.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example and not limitation in the accompanying drawings in which like reference numbers indicate similar parts and in which:
FIG. 1 depicts a section of a turbocharger assembly;
FIG. 2 depicts the rotating components in a turbocharger;
FIG. 3 depicts the orbits made in testing;
FIG. 4 depicts a compressor wheel casting;
FIG. 5 depicts a machined compressor wheel;
FIG. 6 depicts the compressor wheel mounted on a shaft, with a nut;
FIG. 7 depicts the assembly of FIG. 6 subjected to runout of the nut;
FIGS. 8A and B depict the first embodiment of the invention;
FIGS. 9A and B depict the second embodiment of the invention;
FIGS. 10A and B depict the first variation of the first embodiment of the invention;
FIGS. 11A and B depict the first variation of the second embodiment of the invention; and
FIGS. 12A and B depict the third embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Turbocharger assemblies are core balanced to ensure required life and to control rotational vibration induced noise. The inventor realized that a high percentage of turbocharger cores were not passing the core balance checking station which means that the turbochargers had to be re-processed, some several times, to achieve a “pass” under the core balance limit. The mean number of passes through the core balancing operation was 3, with a maximum allowable of 5, before the core was rejected for major rework. This resulted in major manufacturing and capital costs to the manufacturer.
Compressor wheel machining must be an intricate and extremely accurate task (see above) in order for the compressor wheel center of gravity to lie on the turbocharger axis when the wheel is included in the turbocharger assembly.
As shown in FIG. 7 , as clamp load is applied to the compressor wheel, by rotating the nut to travel down the helix angle of the thread, several events can happen. The act of rotating the nut against the face ( 21 ) on the nose of the compressor wheel can cause the nut to dig into the face and track off-center. This tracking causes the mass center of the nut to move off the turbocharger axis which results in an unbalance (N), equal to the mass of the nut times the displacement (R n ) perpendicular to the turbocharger axis.
This displacement also causes a bending of the stub shaft which results in yet another unbalance force (S), which is equal to the mass of the stub-shaft ( 57 ) deviated from the turbocharger axis ( 35 ) times the displacement (R s ). The bending of the stub-shaft can also cause a displacement of the compressor wheel center-of-gravity, which is indicated in FIG. 7 as an unbalance force of “C”. Resisting these bending events, is the interaction of the outside diametral surface of the stub-shaft ( 61 ), which is a sliding fit with the inside diametral surface ( 26 ) of the hole ( 27 ) in the compressor wheel ( 20 ), aided by the compression of the clamp load applied by the interaction of the internal threads ( 32 ) in the compressor nut ( 30 ) against the threaded end ( 57 ) of the stub-shaft ( 56 ), forcing the lower mounting face ( 22 ) of the compressor wheel against the stub shaft face.
Contrary to the normal and widespread design and manufacturing protocol for machining a compressor wheel with the top surface ( 21 ) of the nose of the compressor wheel machined flat, whereby to make flush contact with a flat-bottomed nut ( 30 ), as shown in FIG. 6 , the inventor, as seen in FIGS. 8A and 8B , added self centering complementary mating contact surfaces to the compressor nut and compressor wheel, for example, an exterior frusto-conical surface ( 92 ) to the compressor nut ( 34 ) and an interior frusto-conical surface ( 95 ) to the top of the nose of the compressor wheel ( 20 ). The surfaces are referred to as “frusta” conical since the peak of the shape would be in the area occupied by the compressor wheel bore, thus, would be “cut off”. This frusto-conical interface prevents the nut from rocking and tracking on the nose of the compressor wheel while centering the top of the compressor wheel and the compressor nut on the shaft. With this exterior frusto-conical interface in place, the nut forces the interior frusto-conical surface in the top of the nose of the compressor wheel to center itself under the nut, and thus the clamping forces are resolved such that they center on the shaft and wheel centerline. This reduces the opportunity for there to be a major out-of-balance force due to any offset of the centers of gravity of the stub shaft, nut, and compressor wheel. As a result, the major unbalance force on the compressor end is confined to only the imbalance of the compressor wheel component itself.
For the purpose of defining the self-centering mating surfaces of the nut and wheel, all that is necessary is that one surface includes an annular region of narrowing concavity, the complementary surface includes a region of widening convexity, which cooperate such that when the two surfaces are brought together, the narrowing concavity and the complementary widening convexity cause the compressor wheel to center under the nut. The surfaces may be, e.g., frusto-conical, frusto-spherical, part conical and part spherical, even mixtures of flat and conical or flat and spherical (“stepped”), or combinations of differently angled conical surfaces or combinations of different curvature surfaces used in the interface of nut and compressor wheel, it is assumed that the conical surfaces can be any angle, and the curve be any curvature, so long as the mating surfaces exhibit concentricity with the shaft axis and cooperate to center the compressor wheel at the shaft axis. The interface shape may even assume the shape of a surface of revolution of a Bezier curve, or the shape of revolution of a path of Bezier curves, so long as the contacting surfaces cooperate to center the nose end of the compressor wheel. The cooperating surfaces could even be provided with one or more concentric, reverse image “ripples”. However, since all designs have a similar degree of effectiveness, manufacturing cost would dictate a preference for simpler, easily manufactured engaging surfaces.
In the first variation of the first embodiment of the invention, as seen in FIGS. 10A and 10B , the exterior and interior frusto-conical elements are reversed as compared to FIGS. 8A and 8B . The interior frusto-conical surface ( 94 ) is fabricated onto the nut ( 36 ), and the exterior frusto-conical surface ( 93 ) is fabricated into the compressor wheel ( 20 ). While geometrically this juxtaposition causes no difference in the assembly of nut and wheel to the shaft, structurally it causes a shift to greater compressive stress on the nose of the compressor wheel.
In the second embodiment of the invention, as seen in FIGS. 9A and 9B , the inventor added an exterior frusto-spherical surface ( 96 ) to the compressor nut ( 37 ) and an interior frusto-spherical surface ( 99 ) to the top of the nose of the compressor wheel ( 20 ). This frusto-spherical interface prevents the nut from rocking and tracking on the nose of the compressor wheel while centering the top of the compressor wheel and the compressor nut on the shaft. With this exterior frusto-spherical interface in place, the nut will center itself on the interior frusto-spherical surface in the top of the nose of the compressor wheel. Thus the clamping forces are resolved such that they center on the shaft and wheel centerline. This reduces the opportunity for there to be a major out-of-balance force due to any offset of the centers of gravity of the stub shaft, nut and compressor wheel. As a result, the major unbalance force on the compressor end is confined to only the imbalance of the compressor wheel component itself.
In the first variation of the second embodiment of the invention, as seen in FIGS. 11A and 11B , the exterior and interior frusto-conical elements are reversed. The interior frusto-spherical surface ( 98 ) is fabricated onto the nut ( 39 ), and the exterior frusto-spherical surface ( 97 ) is fabricated into the compressor wheel. While geometrically this juxtaposition causes no difference to the assembly of nut and wheel to the shaft, structurally it causes a shift to greater compressive stress on the nose of the compressor wheel.
In the third embodiment of the invention, as seen in FIGS. 12A and 12B , the intersection of the top surface of the wheel and the sides of the nose of the wheel is used as the centering medium. In the exemplary third embodiment of the invention, a large chamfer ( 101 ), radius, or spherical surface is machined into the top face, and the side face of the nose of the compressor wheel. The compressor nut ( 39 ) has fabricated into its surface a mating frusto-conical ( 100 ) or frusto-spherical surface. As clamp load is applied to the compressor nut, by rotating the compressor nut down the thread ( 57 ), the nut centers on the compressor wheel ( 20 ) and the nut and compressor wheel center to the stub shaft ( 56 ). This centering at assembly forces the mass centers of the stub shaft, nut, and compressor wheel to become aligned with the turbocharger axis ( 35 ). This centering thus reduces the opportunity for there to be a major out-of-balance force due to any offset of the centers of gravity of the stub shaft, nut, and compressor wheel. As a result, the major unbalance force on the compressor end is confined to only the imbalance of the compressor wheel component itself.
Now that the invention has been described, | Turbochargers operate at extremely high speed, so balance of the rotating core is of the utmost importance to turbocharger life. A special frusto-conical, or frusto-spherical, centering geometry is added to the interface of the compressor nut and the nose of the compressor wheel to aid in keeping the wheel, nut, and stub-shaft centered on the turbocharger axis to reduce the degree of core unbalance. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to improvements in recovering valuable by-products from mixed salt-rich aqueous solutions and, more particularly, to the production of potassium sulfate and sodium sulfate from sea water brines, natural bitterns or the like.
2. Description of the Prior Art
There are numerous solar salt facilities around the world operating under a wide variety of plant sizes and operating conditions. Such facilities, however, have not been expanded to recover by-product salts from their residual brines because of the complexity of the salts contained therein and the comparatively large expenditures of capital equipment that would be necessitated under current technology to recover significant quantities of valuable by-product salts. Additionally, by-product recovery is exacerbated by the fact that potassium salt concentrations in residual brines is low and such potassium usually crystallizes in the form of various double salts mixed with magnesium sulfate and sodium chloride.
One system which discloses a variety of processing techniques for the recovery of valuable potassium salts is U.S. Pat. No. 3,528,767. This patent describes the solar evaporation of bitterns with sequential segregation of the precipitating salts so that various potash-rich fractions may be isolated and processed separately. The processing includes suitable crushing and classification followed by a flotation separation. When it is desired to produce potassium sulfate as an end-product, generally the potassium salts are converted to schoenite which is subsequently converted with hot water or aqueous potassium chloride solutions to yield the potassium sulfate product. A problem with the aforementioned processing is that the salts which are precipitated in the evaporation ponds do not provide any simple method or opportunity for producing sodium sulfate.
SUMMARY OF THE INVENTION
This invention comprehends a significantly improved process which is commercially feasible for use with bitterns having a significant potassium concentration. The process involves the initial reduction of sulfate ion concentration in a feedstock brine from a range of about 10-15 moles per 1000 moles water to about 6-9 moles per 1000 moles water. This is accomplished by cooling the brine having a concentration of less than about 20 moles per 1000 moles of water into a metastable zone so that only glauber salt (Na 2 SO 4 .10H 2 0) crystallizes, and then producing salt cake (Na 2 SO 4 ) by salting out with a recycle salt epsomite mixture from a later schoenite flotation step.
By removing part of the sulfate ion in the above manner salt (NaCl) crystals, which may be subsequently recovered by solar pond evaporation to improve overall salt plant yield, will not be contaminated by sulfate. Additionally, initial sulfate removal allows the first potassium salt produced from a subsequent pond evaporation step to be sylvinite which can thereafter be harvested separately. The recovery of a sylvinite-rich fraction provides a highly significant advantage in that it may be subsequently combined with schoenite with a flotation purifying step to produce high yields of potassium sulfate. A still further significant advantage is that the reject salts from the flotation step comprises the recycled salt mixture used to salt-out sodium sulfate at the beginning of the process.
DESCRIPTION OF PREFERRED EMBODIMENTS
The flow sheet on the accompanying drawing represents a preferred embodiment for carrying out the present invention. Brine is taken from a salt processing plant at a specific gravity or density of about 29° Be or less. At this density it will be understood that substantially all gypsum and a major portion of salt (NaCl) have been already precipitated out of the brine.
The following table illustrates typical brine concentrations at increasing densities:
______________________________________ Solution Composition, moles/1000Density Mg, moles H.sub.2 O°Beg/cc Wt. % MgSO.sub.4 MgCl.sub.2 K.sub.2 Cl.sub.2 Na.sub.2 Cl.sub.2______________________________________25.0 1.208 1.03 5.53 5.17 0.99 48.9828.5 1.245 2.4 10.33 16.15 2.44 36.2030.0 1.261 3.6 12.50 25.35 3.27 27.7931.8 1.281 4.5 16.17 31.76 3.97 19.7033.8 1.304 5.5 19.39 40.85 6.13 13.3134.7 1.315 6.0 17.53 48.45 7.18 9.8835.2 1.321 6.5 15.42 56.60 7.58 6.4435.5 1.324 7.0 13.06 63.81 5.80 3.4835.6 1.325 7.5 10.97 70.31 2.69 1.72______________________________________
The aforementioned residual brine flows from the main salt plant and is combined in line 16 with a recycle stream 14. The stream 14 is supernatent liquor from a salt cake conversion step to be hereinafter described. The residual brine and supernatent liquor form the feedstock to the process of the present invention.
The combined feedstock flows through line 16 to a series of heat exchangers 12. The heat exchangers are designed so that the feedstock may be rapidly cooled from ambient to a temperature of less than 0° C. and preferably to a temperature of between 0° C. and -10° C. At such temperatures and at the preferred density of about 28.5° Be, glauber salt (Na 2 SO 4 .10H 2 0) will be crystallized to the exclusion of unwanted salts such as epsomite (MgSO 4 .7H 2 0). (Reference: International Critical Table of Numerical Data, Physics, Chemistry & Technology, Published for the National Research Council by McGraw-Hill, New York, 1926-1930, p. 282 7 volumes plus index; Kali and Steinsalz, 1 (1955) No. 11, pp. 18-32.)
The rapidly cooled brine flows through line 18 to glauber salt crystallizers 20. Since the cooling must be sufficiently rapid through intermediate temperatures to avoid precipitation of epsomite, it can be seen that the crystallizers should also be equipped with suitable cooling means. Generally, by maintaining the large circulating magma in the crystallizers at the desired temperature, an entering feed stream will be quickly cooled to the preexisting temperature. In some cases, the heat exchangers 12 may not be necessary. Crystallization is also enhanced by insuring supersaturation by maintaining a large seed bed of glauber salt crystals.
Glauber salt crystals are separated from the mother liquor by centrifuging or the like (not shown) and the cold supernatent liquor is pumped through line 30 and used as a heat exchange medium by countercurrent flow through the aforementioned heat exchangers 12. In this way heat loss is minimized and the cooling step is rendered more energy efficient. The liquor exits the heat exchangers through line 32 and flows as the main feed stream to a series of solar evaporation ponds.
The glauber salt crystals are transported through line 22 to salt cake crystallizers 24. Here, the glauber salt is converted to salt cake (Na 2 SO 4 ) by salting out with a recycle salt mixture incoming through line 26. The recycle stream comprises an aqueous mixture of sodium chloride and epsomite crystals from the reject underflow of flotation cells 66. Such crystals are preferably separated from the mother liquor underflow, washed, and recycled to line 26. Alternately, the glauber salt mixture can be subjected to a drying or evaporation treatment to yield salt cake.
The salt cake crystals from crystallizer 24 are separated from the mother liquor by centrifuging, filtering or the like and washed, dried and collected as product. The mother liquor therefrom is returned to the beginning of the overall process through line 14 described hereinabove.
Supernatent liquor recovered from the aforementioned glauber salt crystallization step enters successively four ponds which are shown schematically in the flow sheet. It will be appreciated that more ponds could be used depending on the type of salts present and the desired recovery products. The ponds are arranged to sequentially evaporate water from the entering feed stream liquor to thereby allow the selective harvesting of the desired salts.
The first or preliminary solar pond 40 produces sodium chloride alone. The sodium chloride (salt) is recovered by means known in the art and processed in the same manner as salt in the main salt plant. It will be understood that since a major portion of the sulfate ions have been removed from the feed stream liquor as salt cake, the sodium chloride is recovered in a purity comparable to that recovered in the main plant.
From the preliminary sodium chloride pond 40, the supernatent liquor flows to a second pond 42 whereby additional water is evaporated and sylvinite (KCl plus NaCl) precipitates in quantities suitable for effective recovery. Supernatent liquid from the sylvinite pond 42 flows to a third pond 44 wherein water is evaporated and mixed potash salts precipitate and are recovered therefrom by means known in the art. Generally, such mixed potash salts comprise varying amounts of kainite, carnallite and possibly some schoenite.
The supernatent liquor from the third pond is subsequently flowed to a fourth pond 46 which is a repository for the end liquor. Such liquor generally contains a high concentration of magnesium chloride which, if economics permit, can be recovered and/or converted to magnesia or other compounds in which a market may be found.
Referring back to pond 42, the sylvinite recovered is comminuted and classified at reference numeral 54 by means known in the art. Since the sylvinite is preferably handled as a sludge, it may be necessary to thicken it prior to its transport through line 56 to flotation cells 66. Generally, the sylvinite particles should be reduced to a size that can be effectively floated or otherwise treated.
Referring now to pond 44, the mixed potash salts are recovered by means known in the art and, with optional crushing and/or classifying pre-treatment, the salts are transported to a crystallizer 60. In the crystallizer, the mixed potash salts are converted to a crude schoenite mixture by the techniques discussed in U.S. Pat. No. 3,528,767 which is herein incorporated by reference.
The crude schoenite mixture leaves the crystallizers and is mixed with the pre-treated sylvinite from line 56 to form a primary mixture in line 62 which flows to the flotation cells 66. The flotation cells, known in the art, operate in conjunction with appropriate flotation reagents to effect a separation of schoenite and potassium chloride from unwanted reject salts. In this way the crude sylvinite and schoenite mixtures are purified and/or refined to produce an appropriate reaction mixture for a subsequent potassium sulfate conversion step. The reject underflow 68 from the flotation cells include materials suitable for the glauber salt salting-out step. Such recycle salt consists of an impure sodium chloride/epsomite mixture which, after appropriate pretreatment, is recycled to line 26 for use in the aforementioned salt cake crystallizer 24.
The refined overflow mixture flows through line 72 to crystallizer 80 whereby potassium sulfate is produced by metathesis and/or leaching reaction known in the art (note U.S. Pat. No. 3,528,767). The potassium sulfate is formed into crystals suitable for facilitating further handling such as drying and storage as a final product. The supernatent reaction liquor is preferably recycled to the schoenite crystallizers 60 through line 84.
While the invention has been described with respect to preferred embodiments, it should be understood that various changes may be made without departing from the spirit and scope of the invention which is particularly set forth and claimed hereinbelow. | The improved production of sodium sulfate, potassium sulfate and other valuable salts from salt plant bitterns or the like wherein initial reduction in sulfate ion concentration yields salt cake and greatly facilitates the selective recovery of potassium and other valuable by-product salts. The process includes cooling the bitterns while below a certain concentration to produce glauber salt, followed by successive solar evaporation steps to yield harvestable potash salts. The salts are selectively treated and then refined by flotation. The flotation overflow is converted to potassium sulfate product by decomposition and crystallization steps and the underflow provides a recycle salt mixture for converting the glauber salt to salt cake. | 2 |
The present invention relates to a coupling force control system for a fluid coupling with a lockup mechanism disposed between input and output elements.
BACKGROUND OF THE INVENTION
1. Field of the Invention
A coupling force control system for a fluid coupling equipped with a lockup mechanism, such as a torque convertor of an automatic transmission for an automotive vehicle, typically changes a coupling force to regulate slippage of the fluid coupling to a target amount in a predetermined region of engine operating conditions. The lockup mechanism provides the fluid coupling with an increase in coupling force when slippage, defined as the difference between rotational speeds transmitted to and from the fluid coupling, rises above a predetermined or target amount, and a decrease in coupling force when slippage falls below the predetermined or target amount.
2. Description of Related Art
A coupling force control system of the type referred to above is known from, for example, Japanese Unexamined Patent Publication No. 57-33,253. In such a system, when an accelerator pedal is depressed to release the lockup mechanism while the engine operates in a specific region of operating conditions, it is desirable not to instantaneously release the lockup mechanism, but rather to gradually lower the coupling force of the lockup mechanism at a constant rate so that the lockup mechanism allows slippage to increase gradually as it is uncoupled. Such a gradual increase of slippage in the lockup mechanism suppresses an abrupt increase in the rotational speed of the engine and helps to improve drive feeling.
Nevertheless, in the system mentioned above, in spite of a large displacement of the accelerator pedal, accompanied by an abrupt increase of drive torque, the lockup mechanism is unlocked with a gradual increase of slippage. Consequently, the frictional elements of the lockup mechanism are subjected to excessive wear, and the durability of the lockup mechanism is lowered.
SUMMARY OF THE INVENTION
It is, therefore, a primary object of the present invention to provide a fluid coupling with input and output shafts connected by a lockup mechanism which is uncoupled with a gradual reduction of coupling force.
It is another object of the present invention to provide a fluid coupling with its input and output shafts connected by a lockup mechanism which can be uncoupled at a speed suitably varied for improved durability.
These objects of the present invention are accomplished by providing a fluid coupling with a lockup mechanism which is unlocked at an increased speed upon a large displacement of the accelerator pedal. The fluid coupling is provided with an activation means for applying hydraulic pressure to the lockup mechanism to couple and uncouple the fluid coupling. The activation means is controlled, by release control means, so as to decrease gradually the hydraulic pressure at a predetermined rate. The fluid coupling is uncoupled with a gradual decrease in coupling force in a predetermined engine operating condition. The predetermined rate of pressure decrease is changed so as to advance the uncoupling of the fluid coupling when an engine load sensor detects engine loads higher than a predetermined engine load, while the release control means controls the activation means so as to gradually decrease the hydraulic pressure.
According to the fluid coupling of the present invention, because the coupling force of the lockup mechanism is gradually reduced at a predetermined rate of change when the lockup mechanism is released to unlock the fluid coupling, an abrupt increase in engine speed, arising from the release of the lockup mechanism, is prevented. Moreover, when the accelerator pedal is depressed heavily and, as a result, the engine load is suddenly increased, because the reduction of the coupling force becomes more rapid, the speed at which the lockup mechanism is released is hastened, so that wear of the friction elements of the lockup mechanism is effectively suppressed. Durability of the elements is, therefore, maintained.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and features of the present invention will be apparent to those skilled in the art from the following description, which is directed to a preferred embodiment of the invention, when considered in conjunction with the appended drawings, in which:
FIG. 1 is an illustration showing a hydraulic pressure circuit for controlling hydraulic pressure applied to a fluid coupling, having a lockup clutch, so as to change the coupling force of the fluid coupling;
FIG. 2 is a block diagram of a control system for the fluid coupling;
FIG. 3 is a flow chart illustrating a coupling force control sequence;
FIG. 4 is a diagram showing a slip control region of engine operating condition;
FIG. 5 is an explanatory diagram of changing a duty rate for acceleration;
FIG. 6 is an explanatory diagram of changing a duty rate for hill climbing; and
FIG. 7 is a graph showing the opening characteristics of the throttle valve as a function of vehicle speed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings in detail and, in particular, to FIG. 1, a fluid coupling, such as a torque converter 2, with a lockup mechanism for an automotive automatic transmission, is shown. The fluid coupling includes a pump 2a, a turbine 2b and a stator 2c. The pump and turbine 2a and 2b are, respectively, fastened to such shafts as an engine crankshaft or engine output shaft 1 and a transmission shaft 3 of a transmission. The transmission may be, for example, a four speed automatic transmission (not shown). The pump and turbine 2a and 2b are placed face to face with a slight clearance between them. The stator 2c, which performs torque amplification, is located between the pump 2a and turbine 2b.
The torque converter 2 is provided with a lockup clutch 5 forming a lockup mechanism between the turbine 2b and a housing or converter case 4. When the lockup clutch 5 is activated, the pump 2a and turbine 2b, and hence the engine output shaft 1 and transmission shaft 3, are mechanically connected or locked together. The lockup clutch 5 is urged alternatively in the lockup direction (to the right as viewed in FIG. 1), by hydraulic pressure introduced in its lockup pressure chamber 5a on a side of the turbine 2b, and in the non-lockup direction (to the left), by hydraulic pressure introduced in its release pressure chamber 5b on a side of the housing. The lockup clutch 5 is activated by a hydraulic pressure control circuit A.
In the hydraulic pressure control circuit A is a lockup control valve 10 for governing or controlling the supply of oil to the lockup clutch 5. The lockup control valve 10 is provided with a spool 10a and a spring 10b for urging the spool 10a to the right as viewed in FIG. 1. The lockup control valve 10 has a line pressure inlet port 10c, through which the line pressure is introduced into the lockup control valve 10, and a release pressure outlet port 10d connected to the lockup pressure chamber 5a of the lockup clutch 5. These inlet and outlet ports 10c and 10d are brought into communication with each other when the lockup control valve 10 forces the spool 10a to the right so as to allow the line pressure to be applied into the lockup pressure chamber 5a through a lockup pressure line 11a. The lockup control valve 10 further has a lockup pressure outlet port 10e and a tank port 10f. The lockup pressure outlet port 10e is in communication with the release pressure chamber 5b of the lockup clutch 5 through a release pressure line 11b and with a pressure chamber 10g through a branch pressure line 11c branching off from the release pressure line 11b. The hydraulic pressure P1 at the lockup pressure outlet port 10e acts on the spool 10a at the left-hand end via the branch pressure passage 11c. The pilot pressure chamber 10g is in communication with an oil tank 14 via a pilot pressure line 12, having a duty solenoid valve 13 disposed therein. The duty solenoid valve 13 opens and closes the pilot pressure line 12.
The duty solenoid valve 13 keeps the pilot pressure line 12 open when it is operated at a duty rate D of 100% and closed when it is operated at a duty rate D of 0%. As is well known, changing the duty rate D of the duty solenoid valve 13 causes a change in fluid flow from the pilot pressure line 12 to the tank 14 so as to regulate the pilot pressure Po applied to the lockup control valve 10. According to the difference between pressures acting on the opposite ends of the spool 10a produced by the hydraulic pressure P1 at the lockup pressure outlet port 10e, the pressure SP1 applied by the spring 10b, and the pilot pressure Po at the pilot pressure port 10h, the lockup control valve 10 allows the spool 10a to move reciprocally to the right and left so as to bring the lockup pressure outlet port 10e alternatively into communication with the line pressure inlet port 10c and the tank port 10f. In this way, the hydraulic pressure P1 developed at the lockup pressure outlet port 10e, which acts as a release pressure on the lockup clutch 5, is regulated corresponding to the pilot pressure Po in the pilot pressure line 12. The coupling force of the lockup clutch 5 is proportional to the hydraulic pressure Pl developed at the lockup pressure outlet port 10e.
Accordingly, when duty solenoid valve 13 operates, at a duty rate of 100%, to fully open the pilot pressure line 12, the lockup control valve 10 shuts off the communication between the line pressure inlet port 10c and the lockup pressure outlet port 10e so that no hydraulic pressure is applied into the release pressure chamber 5b of the lockup clutch 5. The lockup clutch 5 is, therefore, completely coupled with a maximum coupling force. With a gradual reduction of the duty rate D, the lockup control valve 5 correspondingly develops hydraulic pressure in the release pressure line 11b and decreases hydraulic pressure in the lockup pressure line 11a. When the duty rate D is changed to 0%, the lockup clutch 5 is completely uncoupled.
Referring to FIG. 2, an electrical control unit, for controlling the duty rate D of the duty solenoid valve 13 so as to control the lockup control valve 10, is shown. The coupling force of the lockup clutch 5 is varied by the electrical control unit as the duty rate D is changed. The control unit, which includes a central processing unit (CPU) 20, receives various signals, such as those representative of vehicle speed V, throttle opening Th, transmission gear position Gp, engine speed Ne, and turbine speed Nt. Such signals are generated by a vehicle speed sensor 21, a throttle opening sensor 22, a transmission gear position sensor 23, an engine speed sensor 24, and a turbine speed sensor 25, respectively. All of these sensors are well known to those skilled in the art and, accordingly, are not described.
The operation of the lockup clutch 5 depicted in FIG. 1 is best understood by reviewing FIG. 3, which is a flow chart illustrating a coupling force control routine.
After starting the coupling force control routine, various signals are read at step S1 to determine a vehicle speed V, a throttle opening Th, a transmission gear position Gp, an engine speed Ne and a turbine speed Nt. The difference between the engine speed Ne and the turbine speed Nt is calculated at step S2 in order to determine actual slippage Ns caused between the input and output shafts of the torque converter 2. In addition, another calculation is made at step S3 to determine the deviation DN of the actual slippage Ns from a target slippage No. After these calculations are performed, a decision is made at step S4, based on the vehicle speed V and throttle valve opening Th, whether the engine operates within a slip control region shown in FIG. 4. If the answer to the decision made in step S4 is yes, the engine is operating within the slip control region. Then, further decisions are made, at steps S5, S6 and S7, regarding the rate of change DTh of the throttle opening Th, the throttle opening Th itself and the engine speed Ne, respectively. When the rate of change DTh of the throttle opening Th is smaller than a predetermined rate DTho, it is decided that there is no demand for acceleration of the vehicle. When the throttle opening Th is smaller than a predetermined opening Tho and the engine speed is larger than a predetermined engine speed Ne1, it is judged that the vehicle is not moving down a slope. It is to be noted that the predetermined speed Ne1 and the predetermined throttle opening Tho are upper critical values for defining what is considered to be a low speed engine operating zone. If the answers to all the decisions made in steps S5, S6 and S7 are yes, a control is made to cause the coupling force of the lockup clutch 5 to approach a target coupling force value. For the coupling force control, control parameters A and B, necessary for calculation of a feedback control slippage for slip control, are determined at step S8. The control parameters are determined based on experience, and depend on characteristics, such as size, of the engine. Then, the feedback control value U for slippage is calculated, based on the deviations DN(i) and DN(i-1) of the actual slippage Ns(1) and Ns(i-1), from the target slippage No for the present and previous sequence cycles (i) and (i-1), respectively, and the control parameters A and B at step S9. Specifically, the feedback control value U is calculated from the following equation:
U=A×DN(i)+B×DN(i-1)
Thereafter, the duty rate correction value DD is retrieved from a duty rate correction map (not shown) defined relative to feedback control value U for slippage. The duty rate correction value is used to determine a duty rate D(i) for the present sequence cycle by correcting a duty rate D(i-1) for the previous sequence cycle with the duty rate correction value DD at step S10. At step S11, the previous slippage deviation DN(i-1) is replaced by the present slippage deviation DN(i).
If the answer to the decision made at step S4 regarding the slip control region is no, this indicates that the engine operating condition is within a lockup region or a torque converter control region shown in FIG. 4. Then, a decision is made at step S12 as to whether a transition of the engine operating condition (IA S-T EC) from the slip control region to the torque converter control region has just occurred. If the answer to the decision made at step S12 is no, the previous slippage deviation DN(i-1) is replaced with the present slippage deviation DN(i) at step S13. A decision is made at step S14 as to whether or not the engine operating condition is within a lockup region. The duty rate D is set to its maximum rate Dmax at step S16 when the engine operating condition is within the lockup region so as to completely activate the lockup clutch 5. Otherwise, the duty rate is set to its minimum rate Dmin at step S16 when the engine operating condition is out of the lockup region so as to completely release or uncouple the lockup clutch 5.
If the answer to the decision made at step S12 is yes, this indicates that a transition of the engine operating condition from the slip control region to the torque converter control region has just occurred Then, the duty rate D is changed stepwise by decrements, at a predetermined change rate DDf, to the minimum rate Dmin at step S17 for feedforward control so as to bring the lockup clutch 5 into complete uncoupling.
If the answer to the decision regarding the rate of change DTh of the throttle opening made at step S5 is no, this indicates that there is a demand for acceleration. Then, the duty rate D is changed stepwise by decrements, at the predetermined change rate DDf, to the minimum rate Dmin at step S18 for acceleration feedforward control so as to completely uncouple the lockup clutch 5. When the throttle opening Th is smaller than the predetermined opening Tho and the engine speed Ne is smaller than the predetermined speed Ne1, the duty rate D is changed stepwise by decrements, at the predetermined change rate DDf, to the minimum rate Dmin at step S21 for anti-vibration (U-V) feedforward control. The lockup clutch 5 is thus brought into complete uncoupling. This U-V feedforward control is executed to suppress vibrations during low speed engine operation. However, if the throttle opening Th is larger than the predetermined opening Tho, another decision is made at step S19 as to whether the engine speed Ne is lower than a predetermined speed Ne2. It is to be noted that the predetermined speed Ne2 is higher than the predetermined speed Ne1 and is considered to be the upper critical engine speed for defining a hill climbing engine operating zone. This zone is defined when the throttle opening Th is greater than the upper critical throttle opening Tho. If the answer to the decision made at step S19 is yes, this indicates that the vehicle is traveling or climbing uphill. Then, the duty rate D is changed stepwise by decrements, at the predetermined change rate DDf, to the minimum rate Dmin at step S20 for uphill travel feedforward control so as to completely uncouple the lockup clutch 5. Otherwise, if the answer to the decision at step S19 is no, the decision regarding the predetermined speed Ne1 is made at step S7. In any feedforward control, the decrement of the predetermined change rate DDf is performed as is shown in FIG. 5.
After any of the steps S11, S15, S16, S17, S18, S20 or S21, a decision is made at step S22 as to whether any feedforward control takes place to change the duty rate D stepwise by decrements, at the predetermined change rate DDf, for gradually releasing or uncoupling the lockup clutch 5. If the answer to the decision is yes, a final decision is made at step S23 as to whether the throttle opening Th is larger than a specific throttle opening Thv, which varies according to the vehicle speed V as is shown in FIG. 7. The specific throttle opening Thv, used for the determination of engine load, is made smaller as the vehicle speed V becomes higher. If the answer to the decision is yes, this indicates that the engine is operating under higher loads. Then, the duty rate D is immediately changed to a minimum rate Dmin at step S24 so as to completely release or uncouple the lockup clutch 5. Finally, after establishing the duty rate D in the above described manner, a drive signal is provided to drive the duty solenoid valve 13 at the established duty rate D at S25. The final step orders return to the first step at step S1.
As is apparent from the above, when the engine is subjected to an acceleration demand, when the vehicle travels uphill, or when the engine is subjected to a low load and low speed operation, the lockup clutch is released by gradually reducing the coupling force. Such a coupling force reduction is accomplished by changing the duty rate D by decrements at the predetermined rate DDf of change. Furthermore, when the throttle opening sensor 22 detects throttle openings Th which are greater than the predetermined opening Thv, indicating higher engine loads, during the reduction of the coupling force of the lockup clutch 5, the duty rate D is immediately changed to the minimum rate Dmin. The lockup clutch 5, therefore, is instantaneously and completely released.
Accordingly, the lockup clutch 5 is released or uncoupled when the engine operating condition is within a region in which torque multiplication is required in the torque converter 2. In other words, the lockup clutch is released immediately after the transition of an engine operating condition from the slip control region to the converter region, when the engine is under acceleration during which the change rate DTh of the throttle opening is greater than the predetermined rate DTho, when the vehicle travels uphill, when the throttle opening Th is greater than the predetermined throttle opening Tho and the engine speed Ne is higher than the predetermined speed Ne2, and when the engine operating condition enters into a region in which vehicle vibrations are easily caused, wherein the throttle opening Th is smaller than the predetermined throttle opening Tho and the engine speed Ne is lower than the predetermined speed Ne2. In these engine operating conditions, the coupling force of the lockup clutch 5 is gradually reduced, corresponding to stepwise changes by decrements at the predetermined rate DDf. Consequently, the engine speed is changed smoothly and does not undergo an abrupt increase.
Moreover, even when a reducing control of the coupling force, as described above, is present, when the throttle opening Th of the throttle valve is made larger than a specific throttle opening Thv, corresponding to a vehicle speed V, due to a large depression of the accelerator pedal, the duty rate D is immediately changed to the minimum rate Dmin. The lockup clutch 5 is thus instantaneously and completely released or uncoupled. This prevents the friction elements of the lockup clutch 5 from being subjected to abrasion for a long time and, therefore, improves the durability of the lockup clutch 5.
It is to be noted that although the duty rate D is immediately changed to the minimum rate Dmin when the engine operates in a specific region of higher loads, defined by throttle openings Th which have greater than the specific throttle openings Thv according to vehicle speeds V, the change rate DDf of duty rate DDD is greater in the high load region than in the regions wherein a reducing control of the coupling force is performed.
By means of the fluid coupling force control system of the present invention, releasing of the lockup mechanism is performed gradually. An abrupt increase of engine speed is, therefore, prevented when the lockup mechanism is released, so as to provide an improvement in the feel of operation. In addition, when engine load is suddenly increased, etc., as the lockup mechanism is gradually released, its speed of release is hastened, suppressing wear, so that the durability of the lockup mechanism is improved. Thus, an improvement in operating feeling is provided, and the durability of the lockup mechanism is maintained.
It is to be understood that although the present invention has been described with respect to a preferred embodiment thereof, various other embodiments and variants, which fall within the scope and spirit of the invention, may be possible. Such other embodiments and variants are intended to be covered by the following claims. | A fluid coupling has a lockup mechanism, which is unlocked at an increased speed upon a large displacement of an accelerator pedal, and is provided with an activator for applying hydraulic pressure to the lockup mechanism to couple and uncouple the fluid coupling. The activator is controlled by a release controller so as to decrease graudally the hydraulic pressure at a predetermined rate. The fluid coupling is thus uncoupled with a gradual decrease of coupling force when an engine operates in a predetermined engine operating condition. The predetermined rate of pressure change is modified so as to advance uncoupling of the fluid coupling when an engine load is higher than a predetermined engine load, while the release controller controls the activator so as to decrease gradually the hydraulic pressure. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/811,791 filed Jun. 8, 2006, the entire contents of which is hereby incorporated by reference.
FIELD OF THE INVENTION
The present invention is directed to processes for extracting hemp fibers.
BACKGROUND OF THE INVENTION
Historically, hemp fibers have been used in the textile industry. However, recent breakthroughs in materials science have allowed strong and renewable fibers, for example those from hemp, to replace glass fibers as reinforcement in composite materials. Development of protocols to extract hemp fibers while maintaining their integrity is an important aspect to their use in both the textile industry and in composite materials. Such protocols preferably avoid the use of hazardous and/or non-biodegradable agents.
In common fiber plants, e.g. hemp, flax and jute, a bark-like layer containing bast fibers surrounds a woody core. The bast fibers are surrounded by pectin or other gums. Decortication, either manually or mechanically, is a Process to remove the bark-like layer from the woody core.
Extraction of fiber from the decorticated bark would allow its eventual usage. Extraction primarily involves removal of pectin and colour-containing materials from the fiber (degumming). Pectin is a polysaccharide which is a polymer of galacturonic acid. Pectin is not soluble in water or acid. However, it can be removed by strong alkaline solutions like caustic soda (concentrated sodium hydroxide).
General methods for isolation of clean fibers include dew retting, water retting, and chemical and enzymatic processes, with different variations. In these methods, the glue that holds the fibers together must first be loosened (or removed altogether) by retting. In conventional retting, stalks are dew-retted by allowing them to lie in the field after cutting. In some areas of the world, hemp is water-retted by placing bundles of stalks in ponds or streams. These retting approaches depend on digestion of pectin by enzymes secreted by microbes thriving under favorable conditions. Although water-retting yields more uniform fiber, the process pollutes the water. Dew-retting requires anywhere from two to six weeks or more to complete, requiring the stalks to be turned at least once for highest-quality fiber. Dew-retting is thus affected by the weather, which offers no guaranty of favorable conditions.
On an industrial scale, chemical retting is common. It involves violent, hazardous chemicals like soda ash, caustic soda and oxalic acid. Enzyme retting involves the action of pectinase with or without other enzymes like xylanase and/or cellulase. However, the practical application of such enzymes for isolation of hemp fiber remains to be proven.
Various retting processes are known in the art. Clarke et al (2002) describes a process of removing pectin or gummy materials from decorticated bast skin to yield individual fibers by placement of the bast skin (with or without soaking in an enzyme solution in a pretreatment process) into a closed gas-impermeable container such as plastic bag. The enzyme-producing microbes natural to the bast skin, will thrive on the initial nutrients released by the enzyme pretreatment and will finish the retting process in this closed environment. Clarke et al (2002) also describes an alternative pre-treatment process involving chemicals instead of enzymes, and this includes caustic soda, soda ash, sodium silicate, oxalic acid and ethylenediaminetetraacetic acid (EDTA).
Both chemical and enzyme retting processes generally utilize common chelating agents like oxalic acid and EDTA to expedite the process. All have their problems in application and disposal on an industrial scale. Oxalic acid is classified or designated as a toxic, corrosive and hazardous material (particularly to the kidneys) by various jurisdictions (WorkSafe criteria). EDTA is very inert with no or negligible ability to biodegrade in the environment. EDTA is found in many natural waters and occurs at higher levels in wastewater effluents. EDTA has already been banned in Western European countries, in Australia and in parts of the United States of America, and many countries severely restrict or carefully control EDTA as a component in detergents or washing agents.
Thus, there is a need for a milder process for isolating hemp fibers that involves environmentally-friendly and/or biodegradable agents.
SUMMARY OF THE INVENTION
In accordance with one aspect of the invention, there is provided a method of extracting hemp fibers from decorticated hemp bast skin comprising pre-treating the decorticated hemp bast skin with an aqueous solution containing di-sodium citrate, tri-sodium citrate or a mixture thereof having a pH of from about 6-13 at a temperature of about 90° C. or less; and subsequently treating recovered fiber with a pectinase.
In accordance with another aspect of the invention, there is provided a method for determining extent of completion of a plant fiber degumming process comprising: treating degummed fiber with a pectinase to release reducing sugar from any residual pectin on the degummed fiber; and, quantifying the released reducing sugar.
In accordance with yet another aspect of the invention, there is provided a method for determining extent of completion of a plant fiber softening process comprising: providing wet processed fiber in a container that constrains the wet processed fiber laterally; placing a weight on top of the wet processed fiber; and, measuring a change in bulk size of the wet processed fiber due to compression by the weight.
An aqueous solution containing di-sodium citrate alone has a pH of about 6. An aqueous solution containing tri-sodium citrate alone has a pH of about 8. Addition of small amounts of a stronger base, e.g. sodium hydroxide, can convert di-sodium citrate to tri-sodium citrate and/or elevate the pH above 8. Caustic conditions, i.e. pH above 13, are avoided. Preferably, the pH is about 8-12. Preferably, the aqueous solution contains tri-sodium citrate.
Concentration of di- and/or tri-sodium citrate is preferably in a range of from about 0.4% (w/v) to about 1.6% (w/v), based on total volume of the aqueous solution. If desired, the pH can be elevated by addition of a stronger base. Preferably, the stronger base is an aqueous solution of sodium hydroxide having a concentration in a range of from about 0.01% (w/v) to about 0.5% (w/v) based on total volume of the aqueous solution.
Temperature of the aqueous solution is about 90° C. or less, preferably in a range of from about 45° C. to about 85° C., more preferably in a range of from about 55° C. to about 85° C., for example in a range of from about 65° C. to about 85° C. The aqueous solution is not subject to pressurization. Extraction is preferably performed for a period of time up to about 10 hours, more preferably up to about 5 hours, even more preferably in a range of from about 1 hour to about 5 hours. The aqueous solution may be stirred or agitated to facilitate extraction.
If desired, pre-treatment of the fibers may occur in more than one stage, a first stage in which the fibers are treated with di-sodium citrate and/or tri-sodium citrate without the addition of a stronger base, followed by one or more further stages in which the fibers are treated with tri-sodium citrate with the addition of a stronger base (e.g. sodium hydroxide, potassium hydroxide, etc.) to adjust the pH, preferably to a pH in a range of from 10-13. Concentrations of the tri-sodium citrate and the stronger base in the further stages are as described above. Temperature and time conditions of the further stages are as described above. Advantageously, the first stage increases extraction efficiency of further stages. If desired, the fibers may be washed with water between stages.
Pre-treatment as described above, whether done in one stage or more than one stage, is advantageously performed without the presence of enzymes, for example without pectinases. As a result of pre-treatment with di-sodium citrate and/or tri-sodium citrate, subsequent enzymatic treatment with pectinase is more efficient and/or may be performed under milder conditions. Advantageously, pre-treatment as described herein permits practical, industrially applicable enzymatic treatment of hemp fibers under mild, environmentally friendly conditions.
Hemp fibers recovered from pre-treatment are preferably rinsed with water before enzymatic treatment with pectinase. Enzymatic treatment of recovered hemp fibers employs one or more pectinases, preferably from fungal or bacterial sources. Preferably, enzymatic treatment is performed in an aqueous medium at a pH of from about 4-6. More preferably, the pH is from about 4.5-5. Preferably, the temperature at which enzymatic treatment is performed is in a range of from about 30° C. to 45° C., more preferably in a range of from about 40° C. to 45° C. Preferably, the aqueous medium contains salts and/or buffers, for example monosodium citrate. Concentration of any salts or buffers should not be too high as to unduly affect activity of the enzyme. For example, the concentration of monosodium citrate may be in a range of about 3-7 mM, e.g. 5 mM.
Preferably, enzymatic treatment of the fibers is performed for a period of time in a range of from about 0.5-36 hours, more preferably from about 0.5-6 hours, for example from about 1-5 hours or from about 0.5-4 hours or from about 1-3 hours. Stirring or agitation of the aqueous medium may be done. Preferably, the aqueous medium is stirred or agitated constantly during enzymatic treatment. Purified fiber after enzymatic treatment may be rinsed with water.
Purified fiber may be subjected to other treatments, for example bleaching, dyeing, etc., for its eventual application.
Advantageously, pre-treatment with di-sodium citrate and/or tri-sodium citrate permits effective extraction of hemp fiber under mild conditions using environmentally-friendly agents. Further, enzymatic treatment of fibers recovered from pre-treatment with di-sodium citrate and/or tri-sodium citrate advantageously increases efficiency of pectin removal during the subsequent enzymatic treatment. Furthermore, pre-treatment of hemp fibers with di-sodium citrate and/or tri-sodium citrate advantageously permits the use of milder enzymatic treatment conditions, thereby permitting recycling of enzymes in the extraction of the fibers. For example, used enzyme solutions can be reused for other batches of fiber up to 4 times, or even more in some cases.
Further, sodium citrates, which have been widely used in detergent and cleaners, are non-toxic, non-carcinogenic, non-bioaccumulative, non-hazardous (according to WorkSafe classification) and highly biodegradable. According to Seventeenth Report of the Joint FAO/WHO Expert Committee on Food Additives, World Health Organisation Technical Report Ser., 1974, No. 539 ; FAO Nutrition Meetings Report Series, 1974, No. 53., citric acid and citrates occur in many foods and are normal metabolites of carbohydrates in all living organisms (Gruber & Halbeisen, 1948).
Citrate is the starting point of the tricarboxylic acid cycle, also known as the Citric Acid Cycle or Krebs Cycle. This cycle is a series of chemical reactions occurring in rhe cells of plants, animals and micro-organisms. Sodium citrate in doses of up to 4 g has been extensively used in medical practice for many years without giving rise to ill effects. Sodium citrates are rapidly and ultimately biodegradable under aerobic and anoxic conditions. For example, sodium citrate attained 90% ThOD (Theoretical Oxygen Demand) in a closed bottle test for ready biodegradability during 30 days.
In contrast, EDTA (though non-toxic) is inert in the environment and banned in various regions for washing purposes. Oxalic acid is classified as a “hazardous and toxic” substance.
Since pectin plays a major role in gluing hemp fibers together, estimation of residual pectin in treated fiber helps to determine the extent of completion of the degumming process, and hence the quality of fiber. Enzyme hydrolysis is a specific reaction, as compared to other chemical processes, which can break down other polysaccharides than pectin. For determination of the removal of pectin from fiber, the enzyme pectinase can be used to hydrolyse any residual pectin from treated fiber. Quantification of the released sugars will indicate the amount of residual pectin on the fiber.
For such quantification, the use of a commercial pectinase from a culture broth of common fungi like Aspergillus can be complicated by co-production of other indigenous polysaccharide-hydrolysing enzymes like cellulases and xylanases during the fermentation process. Such concern of contaminating enzymes can be reduced by using a recombinant pectinase expressed in an organism, for example E. coli , which produces neither cellulase nor xylanase.
Further features of the invention will be described or will become apparent in the course of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be more clearly understood, embodiments thereof will now be described in detail by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is a graph of optical density (O.D.) determined at 350 nm or 270 nm as a function of reaction time (minutes) for the release of materials into solution during extraction of Canadian hemp TAB fibers by a process of the present invention; and,
FIG. 2 is a graph of optical density (O.D.) determined at 350 nm or 270 nm as a function of reaction time (minutes) for the release of materials into solution during extraction of Chinese hemp fibers by a process of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Example 1
Extraction of Fiber from Decorticated Bast Skin of Canadian Hemp
Ten grams of decorticated hemp bast skin of Canadian hemp TAB was pre-treated by agitation in 200 ml of an aqueous solution containing 0.8% (w/v) of tri-sodium citrate at 85° C. for 3 hr. Release of material into solution was monitored via optical density (O.D.) measured by UV-Vis spectroscopy at 270 nm and 350 nm ( FIG. 1 ). The dilution factor to yield the appropriate O.D. is shown in parenthesis in FIG. 1 . Pre-treated fiber was then rinsed twice with water.
Recovered fiber was treated in 200 ml of an aqueous solution containing the enzyme pectinase (Novozyme Pectinase Ultra SP-L, 1040 U) and 5 mM sodium citrate, with pH around 4.5, at 45° C. After 1 hr, the enzyme solution was recovered for recycling. The fiber was rinsed twice. The fiber has a beige color ready to be separated into finer fiber.
Example 2
Extraction of Fiber from Decorticated Bast Skin of Chinese Hemp
Soaking: Ten grams of decorticated hemp bast skin was soaked in 200 ml of water at 80° C. for 30 min.
Step 1: The fiber was then agitated in 200 ml of a solution containing 0.8% (w/v) of tri-sodium citrate at 80° C. for 1 hr. Treated fiber was rinsed twice with tap water.
Step 2: Step 1 was followed by agitation in 200 ml of an aqueous solution containing 0.8% (w/v) of tri-sodium citrate and 0.2% (w/v) of NaOH at 80° C. for 1.5 hr. Treated fiber was rinsed twice with water.
Step 3: Recovered fiber was treated in 200 ml of a solution containing the enzyme pectinase (Novozyme Pectinase Ultra SP-L, 1040 U) and 5 mM sodium citrate, with pH around 4.5, at 45° C. After 1 hr, the enzyme solution was recovered for recycling. The fiber was rinsed twice. The fiber was ready to be separated into finer fiber. Release of materials into each of the solutions was monitored via O.D. measured by UV-Vis spectroscopy at 270 nm and 350 nm ( FIG. 2 ). The dilution factor to yield the appropriate O.D. is shown in parenthesis in FIG. 2 .
Example 3
Softening of Hemp Fiber
After enzymatic treatment from Examples 1 and 2, wet hemp fiber (5 g) was washed with 120 ml of isopropanol for 5 min to produce a colored isopropanol solution. The colored isopropanol solution was decanted, and the fiber was allowed to air-dry. The fiber is softer than those without the isopropanol treatment.
Example 4
Preparation of Recombinant Polygalacturonase of Erwinia carotovora Expressed in E. coli
The production of a recombinant pectinase, i.e. polygalacturonase of Erwinia carotovora , has been accomplished via (i) isolation of the pectinase gene from Erwinia carotovora via PCR, (ii) cloning into a linearized plasmid pTrX, and (iii) expression of the said gene in Escherichia coli . The precursor plasmid pTrX for gene cloning has previously been published (Sung et al., U.S. Pat. No. 5,759,840 issued Jun. 2, 1998 to Sung et al., the disclosure of which is herein incorporated by reference). It contains a functional Trichoderma reesei xylanase gene and therefore can express the enzyme xylanase.
PCR was used to generate a DNA fragment encoding both the secretion leader and the mature pectinase with the PCR primers Ecp-N1a and Ecp-C1a in the construction of plasmid pEcp3a.
Ecp-N1a
1 2 3 4 5 6 7 8
secretion leader E Y Q S G K R V
5′-TT GCT AGC GAA TAT CAA TCA GGC AAG CGA GTT TTA TC
NheI
Ecp-C1a
379 378 377 376 375 374 373 372 371 370
stop K K V T V N K I Q W
5′-AA AGA TCT TTA CTT CTT AAC GGT GAC GTT CTT GAT TTG CCA
Bgl II
SEQ ID NO: 1 = EYQSGKRV
SEQ ID NO: 2 = TT GCT AGC GAA TAT CAA TCA GGC AAG CGA GTT TTA TC
SEQ ID NO: 3 = KKVTVNKIQW
SEQ ID NO: 4 = AA AGA TCT TTA CTT CTT AAC GGT GAC GTT CTT GAT TTG CCA
The PCR template is the DNA of the bacterium Erwinia carotovora which was directly liberated under normal PCR protocol. With the primers Ecp-N1a, a PCR product of 1100 bp was prepared. This product was cut by the restriction nucleases NheI and BglII, and was ligated into a NheI/BglII-linearized plasmid pTrX to generate new plasmid pEcp3a.
Subsequent cloning steps involved (i) transformation into the E. coli HB101 competent cells followed by spreading on YT plate (containing 5 g yeast extract, 3 g bacto-tryptone, 5 g NaCl, 15 g of agar in 1 L of water, 1 g Remazol Brilliant Blue R-D-xylan) and ampicillin (100 mg/L), (ii) identification of the pectinase transformants containing the new plasmid pEcp3a, through the loss of xylanase activity (absence of a clearing zone or halo around the colonies on the blue xylan plate overnight at 40° C.), and (iii) confirmation of the successful cloning through dideoxy nucleotide sequencing of the isolated plasmid pEcp3a.
The production of the recombinant pectinase was accomplished via culture of the E. coli transformants with plasmid pEcp3a. The culture conditions comprised a 5 ml culture of overnight innoculant in 2YT medium (16 g bacto-tryptone, 10 g yeast extract, 5 g NaCl, 1 L of water) containing ampicillin (100 mg/L). It was spread out on an tray (32×25 cm) evenly covered by 0.5 L of solidified YT agar (8 g yeast extract, 5 g bacto-tryptone, 5 g NaCl, 15 g of agar in 1 L of water) containing ampicillin (100 mg/L). The cultures were grown at 37° C. After 40 hr, cells (2 g) were harvested for extraction of pectinase.
The harvested cells were put into a tube for a freeze-thaw extraction of pectinase. The procedure comprised a freezing period in a dry ice/ethanol bath for 5 min, followed by water/ice bath for 10 min. The procedure was repeated thrice. The cells were extracted with buffer (5 mal, 100 mM Na citrate, pH 5.5). Centrifuging at 8000×g for 30 min yielded a supernatant containing pectinase that can directly be used for the analytical assay in Example 5.
Example 5
Analysis of Residual Pectin in Treated Fiber
Extent of removal of pectin from hemp fiber was determined via measurement of the quantity of reducing sugar generated by the specific hydrolysis of residual pectin on the treated fiber by a pectinase.
C1 is a comparative sample of untreated hemp. C2 is a comparative sample of hemp processed with 7% (w/v) NaOH at 90° C., the processing resulting in fiber damage. C3 is a comparative sample of commercially available chemically processed hemp obtained from Aurorasilk Com. (Portland, Oreg., U.S.A.). S1 is a sample of hemp processed in accordance with Example 2.
Commercial processes such as those used to produce the sample C3 generally involve the use of high pressure (e.g. 80 lbs per square inch), high temperature (e.g. 160° C.) and high concentration of sodium hydroxide (e.g. 6% (w/v)).
One of the pectinases used was the recombinant polygalacturonase of Erwinia carotovora expressed in E. coli as prepared in Example 4. The other pectinase used was Novozyme Pectinase (polygalacturonase) from Aspergillus niger . The following general method was used.
A reaction mixture containing 30 mg of treated fiber and 1 U of recombinant pectinase or 20 μl diluted Novozyme Pectinase (50× dilution) in 400 μl of a buffer (100 mM sodium citrate, pH 5.0 for recombinant pectinase, pH 4.5 for Novozyme Pectinase), was heated at 40° C. After 1 hr, 50 μl of the reaction solution was removed and was added into 1 ml of 10 mM NaOH to stop further hydrolysis. The amount of reducing sugar was determined with a well-established method involving the hydroxylbenzoic acid hydrazide reagent (HBAH) (Lever, 1972 Analytical Biochem 47:273-279, the disclosure of which is herein incorporated by reference). After HBAH treatment, the solution turned yellow. The quantity of reducing sugar can be determined though the reading of O.D. at 420 nm, and read against a standard curve with O.D. versus known quantities of galacturonic acid. Table 1 provides results.
TABLE 1
Release of reducing sugar from
Release of reducing sugar from residual
residual pectin (OD 420 ), by
pectin (OD 420 ), by Novozyme Pectinase
recombinant pectinase of
(polygalacturonase) from
Sample
Erwinia carotovora , overnight
Aspergillus niger
C1
2.350
1.353
C2
0.154
0.168
C3
0.169
0.334
S1
0.342
0.215
It is evident from Table 1 that an extraction process of the present invention is effective at degumming hemp fiber. According to analysis by the recombinant bacterial Erwinia carotovora pectinase, the process of Example 2 as represented by Sample S1 was not as effective as the commercial process (C3) or the process using 7% NaOH(C2), but the conditions in C2 and C3 were much harsher and less environmentally friendly. However, alternative analysis by the fungal Aspergillus niger pectinase indicated the reverse order of effectiveness, with S1 possessing less residual pectin than C3. Although slightly different results were obtained from the two analytical tests, both tests generally showed S1 having most of the pectin removed by the process of Example 2 as compared to untreated hemp. This example demonstrates the effectiveness of pectinase-based analysis for determining residual pectin.
Example 6
Method for Monitoring the Softness of the Fiber Mass
Softness of the fiber is a premium quality of the processed fiber, in addition to its brightness and separateness. An efficient method for monitoring the gradual softening of the fiber from a rigid crude mass during the course of treatment is useful for the development of the optimal processing technology.
A monitoring method, called the “Drop Test”, has been established based on the ability of rigid and non-separated fiber strands to stand up to a certain weight added on the top. During the treatment process, the loss of rigidity due to the softening or separation of the wet processed fiber mass will decrease its resistance to stand up to the set weight. This gradual loss of resistance to the set weight can be determined by measuring the decreasing space occupied by the fiber mass in a graduated cylinder. The space occupied by the treated fiber mass is a combination of its swollen bulk and air space caused by the rigidity of the bulk itself.
To this end, wet processed fiber mass, which has already been drained of solution, was placed in a glass graduated cylinder. A weight in form of a Teflon™ puck was gently dropped on top of it. Against the marking of the graduated cylinder, the volume or space occupied by the fiber mass was determined. Such measurement was repeated thrice, and the mean of the 3 measurements was accepted. As the treatment progressed, the degummed fiber mass softened, it started to lose its rigidity to stand up against the puck, thus gradually occupying lesser space in the cylinder.
Example 7
“Drop Test” for Monitoring Canadian Hemp Fiber Processed Via Variations of the 2-Step Protocol of Example 1
Five samples of Canadian hemp fiber were processed via five protocols as outlined in Table 2. S2 represents samples processed in accordance with the present invention. Major variations in the protocol from Example 1 are indicated in parenthesis. The general conditions of Example 1 are indicated in the last row of Table 2 as reference.
TABLE 2
Sample
Step 1
Step 2*
S2
Tri-sodium citrate, 55° C., 5 hr
Pectinase Ultra, sodium
(55° C., 5 hr)
citrate buffer, 45° C.
C4
Tri-sodium citrate, 55° C., 5 hr
Sodium citrate buffer,
(55° C., 5 hr)
45° C. (without pectinase)
C5
Water, 55° C., 5 hr (without
Water, 45° C. (without
tri-sodium citrate; 55° C., 5 hr)
pectinase, or sodium citrate
buffer)
C6
Water, 55° C., 5 hr (without
Sodium citrate buffer,
tri-sodium citrate; 55° C., 5 hr)
45° C. (without pectinase)
C7
Bypassing Step 1
Pectinase Ultra, sodium
citrate buffer, 45° C.
Example
Tri-sodium citrate, 85° C., 3 hr
Pectinase Ultra, sodium
1
citrate buffer, 45° C., 1 hr
*Step 2 was allowed to proceed to show the effect of pectinase on the fiber. The fiber samples were monitored with the “Drop Test” at 2, 4, 6, 24, 30 and 48 hr.
For monitoring the processing of 3 g of decorticated Canadian hemp fiber, a standard 250-ml graduated cylinder with a height of 32 cm, an inner diameter of 3.8 cm and markings for 2 ml was used. A circular Teflon™ puck having an outer diameter of 3.6 cm, a height of 2 cm, a weight of 22 g and three holes of diameter of 0.4 cm drilled vertically in the center, was placed gently into the cylinder to slide onto the top of the fiber mass. A reading of the space occupied by the fiber mass (bulkiness) was made based on the bottom of the puck against the marking on the cylinder.
As the treatment progressed, the fiber started to lose its rigidity and was less able to stand up against the Teflon™ puck. The whole mass became less bulky and softer, thus occupying less space under the weight of the same puck (Table 3).
After Step 1, based on the bulkiness of the processed fibers, it was obvious that samples S2 and C4 treated with tri-sodium citrate in Step 1, had smaller bulk or occupied less space, as compared to C5 and C6 that were processed with water only (44 ml and 48 ml versus 69 ml and 72 ml). Visually S2 and C4 were lighter in color compared to C5 and C6. This confirms the beneficial role of tri-sodium citrate in softening and brightening the fiber. The tri-sodium citrate treatment in Step 1 also enhanced the effect of the subsequent enzymatic Step 2 as indicated below.
TABLE 3
Bulk Size (ml)
Bulk Size (ml)
Step 2
Sample
Step 1
2 hr
4 hr
6 hr
24 hr
30 hr
48 hr
S2
44
40
40
34
32
28
27
C4
48
47
48
39
41
38
39
C5
69
66
64
62
64
64
62
C6
72
72
57
62
65
61
66
C7
—
75
64
57
46
46
45
During Step 2, sample S2 treated with pectinase continued with a greater decrease in bulk over time (12 ml in 24 hr) (Table 3), as compared to C4 (7 ml in 24 hr), which was subjected to sodium citrate buffer without the enzyme.
During Step 2 both samples C5 and C6 treated without pectinase and previously processed with only water in Step 1 showed comparatively smaller decrease in bulk with time (5 ml in C5 vs. 7 ml in C6, after 24 hr) (Table 3). However, visually C6 was brighter than C5, with the former subject to sodium citrate buffer and the latter in water only.
Sample C7, which has bypassed the Step 1 of tri-sodium citrate treatment and relied solely on the pectinase treatment of Step 2 showed a steady decrease in bulk with time (Table 3), contrary to C4, C5 and C6. This confirmed the essential role of pectinase in softening the fiber. However, C7 remained bulkier than S2 after 24 hr (46 ml vs. 32 ml) and 48 hr (45 ml vs. 27 ml) with the size of the bulk not reducing further, unlike sample S2. Furthermore, the processed C7 is visually darker than S2. These differences between S2 and C7 demonstrate the crucial role in Step 1 of tri-sodium citrate for enhancing the subsequent pectinase treatment step in the processing of hemp fiber.
Determination of the Simple Sugars Released During Step 2
The simple sugars released with or without Pectinase Ultra in Step 2 were determined in order to demonstrate the effect of the variations in Steps 1 and 2 outlined in Table 2. The procedure for quantification of released sugar was identical to that described in Example 5. To this end, 50 μl of the reaction supernatant was removed and added into 1 ml of 10 mM NaOH to stop further hydrolysis. The amount of reducing sugar was determined with a well-established method involving the hydroxylbenzoic acid hydrazide reagent (HBAH) (Lever, 1972 Analytical Biochem 47:273-279, the disclosure of which is herein incorporated by reference). After HBAH treatment, the solution turned yellow. The quantity of reducing sugar can be determined though the reading of O.D. at 420 nm as indicated in Table 4.
TABLE 4
Release of reducing sugars
(OD 420 ) during step 2
Sample
2 hr
4 hr
6 hr
24 hr
30 hr
48 hr
S2
0.945
1.279
1.501
2.134
2.445
2.789
C4
0.046
0.110
0.132
0.189
0.206
0.266
C5
0.010
0.014
0.018
0.025
0.029
0.041
C6
0.045
0.079
0.094
0.163
0.184
0.202
C7
1.078
1.558
1.904
2.835
2.930
3.280
Of five samples (Table 4), only S2 and C7 with pectinase in Step 2 released significant amount of reducing sugars into the supernatants. Among the remaining three samples without pectinase in Step 2, sample C5 released little or no reducing sugar in the process,
Analysis of Residual Pectin Retained in Processed Canadian Hemp Fiber
In addition to the “Drop Test” to check the rigidity or softness of the fiber, the extent of degumming in samples S2, C4, C5, C6 and C7 was also investigated. To this end, the residual pectin remaining in the fiber samples was determined via the enzymatic analysis which has already been described in Example 5. For comparison, C3, the commercially available chemically processed hemp obtained from Aurorasilk Com. (Portland, Oreg., U.S.A), was used as a reference. The Novozyme Pectinase (polygalacturonase) from Aspergillus niger , was used to release the reducing sugar from any residual pectin on the samples. The reducing sugar released from the different fiber samples was determined at 2 hr, 5 hr and 24 hr (Table 5).
TABLE 5
Release of reducing sugar from residual pectin (OD 420 )
of the processed fiber samples, by Novozyme Pectinase
Processed
(polygalacturonase) from Aspergillus niger
sample
2 hr
5 hr
24 hr
S2
0.121
0.208
0.537
C4
0.408
0.979
2.756
C5
0.338
0.590
2.093
C6
0.582
1.589
5.196
C7
0.387
0.813
2.954
C3
0.207
0.317
0.548
In the enzymatic analysis (Table 5), sample S2 which was treated with tri-sodium citrate in Step 1 and Pectinase Ultra in Step 2, has very little reducing sugar released by the pectinase at 2 hr, 5 hr and 24 hr. This indicates that it has only retained very little residual pectin, comparable to sample C3, the commercially available chemically processed hemp (0.537 OD versus 0.548 OD respectively at 24 hr).
The other samples C4, C5, C6 and C7, which have not been treated with tri-sodium citrate in Step 1 or pectinase in Step 2, retained significant amount of pectin (2.756, 2.093, 5.196 and 2.954 OD respectively at 24 hr). In sample C7 which bypassed Step 1, the sole treatment with pectinase in Step 2 failed to remove most of the pectin. As a result, a significant amount of residual pectin remained in the processed fiber C7 (Table 5).
Although the processed sample C5 was the most bulky in the Drop Test (Table 3) and demonstrated the least release of simple sugar into the supernatant during Step 2 (Table 4), it released a relatively small amount of reducing sugar in the residual pectin analysis (0.590 OD at 5 hr, Table 5) compared to C4, C6 and C7. This suggests that most of the pectin remained embedded in the processed sample C5.
The existence of embedded pectin in C5 was confirmed when the already processed sample (C5) was subjected to another round of more rigorous processing, involving a Step 1 with tri-sodium citrate (55° C., 5 hr), and a Step 2 with Pectinase Ultra (sodium citrate buffer, 45° C.), both steps involving sodium citrate versus water only in the original design in Table 2. An analysis of the supernatant in the new Step 2, showed a large release of simple sugars from the re-processed C5, with OD of 1.221 and 1.967 after 2 and 6 hr, respectively. This release of reducing sugar waste by the re-processed sample C5 was comparable to that of sample S2 in Table 4, thereby confirming the role of tri-sodium citrate in the degumming process.
Example 8
“Drop Test” for Monitoring Chinese Hemp Fiber Processed Via Variations of the 3-Step Protocol of Example 2
For the processing of 6 g crude Chinese decorticated hemp fiber, a standard 500-ml graduated cylinder with a height of 32 cm, an inner diameter of 5.3 cm and markings for 5 ml was used. A circular Teflon™ puck having an outer diameter of 4.8 cm, a height of 2 cm, a weight of 55 g and three holes of diameter of 0.4 cm drilled vertically in the center was placed on top of the processed fiber to get an accurate reading of the bulk of the mass against the cylinder.
Four samples of Chinese hemp fiber were processed via four protocols as outlined in Table 6. Major variations in the protocol from Example 2 are indicated in parenthesis. The general conditions of Example 2 are indicated in the last row of Table 6 as reference.
TABLE 6
Sample
Step 1
Step 2
Step 3*
S3
Tri-sodium citrate,
NaOH, tri-sodium
Pectinase Ultra,
80° C., 1 hr
citrate, 80° C.,
sodium citrate
1.5 hr
buffer, 45° C.
S4
Tri-sodium citrate,
NaOH, tri-sodium
Same
80° C., 1 hr
citrate, 80° C.,
4 hr (4 hr)
C8
Water, 80° C., 1 hr
NaOH, water, 80° C.,
Same
(without tri-sodium
1.5 hr (without
citrate)
tri-sodium citrate)
C9
Water, 80° C., 1 hr
NaOH, water, 80° C.,
Same
(without tri-sodium
4 hr (without tri-
citrate)
sodium citrate; 4 hr)
Example
Tri-sodium citrate,
NaOH, tri-sodium
Pectinase Ultra,
2
80° C., 1 hr
citrate, 80° C.,
sodium citrate
1.5 hr
buffer, 45° C.,
1 hr
*Step 3 was allowed to proceed to show the effect of pectinase on the fiber. The fiber samples were monitored with the “Drop Test” at 1, 3, 4 and-5 hr.
In summary, samples S3 and S4 were treated with tri-sodium citrate in Steps 1 and 2 in accordance with the present invention. The only difference between S3 and S4 was that the time of Step 2 involving NaOH was extended from 1.5 hr for S3 to 4 hr for S4 (Table 6). The conditions for samples C8 and C9 were identical to those of S3 and S4, except that tri-sodium citrate was absent in both Steps 1 and 2. All 4 samples were eventually treated with pectinase in Step 3.
As the treatment progressed, the fiber started to lose its rigidity and was less able to stand up against the Teflon™ puck. The whole mass became less bulky and softer, thus occupying less space under the weight of the same puck (Table 7). The fiber mass from Step 1 was measured with the 500-ml graduated cylinder as indicated above. In Steps 2 and 3, the fiber mass was measured with the smaller 250-ml cylinder and the smaller puck described in Example 7.
TABLE 7
Bulk Size (ml)
Bulk Size (ml)
Bulk Size (ml)
Step 3
Sample
Step 1
Step 2
1 hr
3 hr
4 hr
5 hr
S3
145
46
43
40
41
38
S4
150
42
40
39
38
38
C8
145
60
58
56
48
48
C9
175
49
52
50
42
40
After Step 1, the four samples remained very rigid and bulky (145-175 ml) (Table 7).
In Step 2 involving sodium hydroxide, S3 and S4 with tri-sodium citrate added in the process had a smaller bulk (46 ml and 42 ml, respectively) (Table 7), as compared to C8 and C9 without the tri-sodium citrate (60 ml and 49 ml, respectively), thus generally confirming the beneficial role of tri-sodium citrate in softening the fiber in the process. The length of treatment (1.5 hr for S3 and C8 versus 4 hr for S4 and C9) also affected the decrease of the bulk in Step 2.
In the pectinase Step 3, samples S3 and S4 which were subject to tri-sodium citrate in Steps 1 and 2, retained a smaller bulk with time (Table 7), as compared to C8 and C9. As an example, after 5 hr with pectinase, the bulks of sample S3 and S4 were 38 ml and 38 ml, versus 48 ml and 40 ml for C8 and C9, respectively. This shows that initial treatment with tri-sodium citrate in Steps 1 and 2 enhance the softening effect on the fiber by pectinase in Step 3.
Analysis of Residual Pectin in Processed Chinese-Fiber
In addition to the “Drop Test” to check the rigidity or softness of the fiber, the extent of degumming in samples S3, S4, C8 and C9 was also investigated. The residual pectin remaining on the fiber samples was determined via the enzymatic process which has already been described in Examples 5 and 7. For comparison, C3, the commercially available chemically processed hemp obtained from Aurorasilk Corn. (Portland, Oreg., U.S.A), was used. The reducing sugar released from the different fiber samples was determined at 2 hr, 5 hr and 24 hr (Table 8).
TABLE 8
Release of reducing sugar from residual pectin (OD 420 )
of the processed fiber samples, by Novozyme Pectinase
Processed
(polygalacturonase) from Aspergillus niger
sample
2 hr
5 hr
24 hr
S3
0.080
0.112
0.335
S4
0.073
0.105
0.363
C8
0.084
0.125
0.439
C9
0.064
0.090
0.270
C3
0.220
0.302
0.575
In the enzymatic analysis (Table 8), all four samples have a smaller amount of reducing sugar released by the pectinase at 2 hr, 5 hr and 24 hr than the reference sample C3, the commercially chemically processed hemp. This indicates that the four samples have retained very little residual pectin, thus all were successfully degummed. Although all four processed samples lost most of their pectin (Table 8), samples S3 and S4 were judged softer or less rigid than C8 and C9, based on the Drop Test (Table 7).
REFERENCES
Jaskowski, M. C., U.S. Pat. No. 4,481,355 issued on Nov. 6, 1984.
Jaskowski, M. C., U.S. Pat. No. 4,568,739 issued on Feb. 4, 1986.
Jaskowski, M. C., U.S. Pat. No. 4,617,383 issued on Oct. 14, 1986.
Raimann, W., U.S. Pat. No. 5,510,055 issued on Apr. 23, 1996.
Sung, W. L., Yaguchi, M. and Ishikawa, K. U.S. Pat. No. 5,759,840 issued on Jun. 2, 1998.
Kling, A. and Specht, V., U.S. Pat. No. 3,954,401 issued on May 4, 1976.
Chiyouzou, H. Espacenet patent abstract of JP 55026267 published on Feb. 25, 1980.
Clarke, A. F., Dennis, H. G. S, Wang, X. and Jurren, C. J.; PCT international application PCT/AU20/00931, published on 10 Jul. 2002.
Adamsen, A. P. S., Akin, D. E. and Rigsby, L. L. (2002) Textile Res. J. 72:789-794.
Zhang, J., Johansson, G., Petterson, B., Akin, D. E., Foulk, J. A., Khalili, S. and Henriksson. G. (2003) Textile Res. J. 73:263-267.
Adamsen, A. P. S., Akin, D. E. and Rigsby, L. L. (2002) Textile Res. J. 72:296-302.
Lever (1972) Analytical Biochem 47:273-279.
Singh, D. P., Report of the Central Research Institute for Jute & Allied Fibres, Indian Council of Agricultural Research entitled “Ramie ( Boemmeria nivea )”. Section entitled “Degumming”. Extracted from the Internet May, 2006.
Ouajai, S. and Shanks, R. A. (2005) Macromol. Biosci. 5:124-134.
Zhang, J. (2006) Doctoral Thesis Dissertation entitled “Biochemical Study and Technical Applications of Fungal Pectinase”. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 137.
Other advantages that are inherent to the structure are obvious to one skilled in the art. The embodiments are described herein illustratively and are not meant to limit the scope of the invention as claimed. Variations of the foregoing embodiments will be evident to a person of ordinary skill and are intended by the inventor to be encompassed by the following claims. | A method of extracting hemp fibers from decorticated hemp bast skin involves pre-treating the decorticated hemp bast skin with an aqueous solution containing di-sodium citrate, tri-sodium citrate or a mixture thereof having a pH of from about 6-13 at temperature of about 90° C. or less; and subsequently treating recovered fiber with a enzyme. Determining the extent of completion of a plant fiber degumming process involves treating degummed fiber with a recombinant pectinase expressed in an organism that produces neither cellulose nor xylanase, to release reducing sugar from any residua pectin on the degummed fiber, and, quantifying the released reducing sugar. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation application of application Ser. No. 09/012,528 filed Jan. 23, 1998 now U.S. Pat. No. 5,948,145, the disclosures of which are incorporated herein by reference.
TECHNICAL FIELD
This invention relates to the recovery and purification of gases, particularly refrigerants, through the use of the venturi effect.
BACKGROUND OF THE INVENTION
Refrigeration systems such as those used in automotive and home appliances and air conditioners require that the refrigerant used be relatively free of foreign matter such as oil, water, and air. Since these systems rely on pressure to keep the refrigerant compressed, it is critical that hermetic integrity be maintained. If the refrigeration system breaks down, the refrigerant must be removed to facilitate the repair of the system. In the past, the refrigerant, a colorless, odorless gas, was discharged into the atmosphere. This discharge not only wasted the relatively expensive refrigerant, but also may have contributed significantly to the breakdown of the ozone layer of the earth's atmosphere. Because fluorocarbons used in automotive and household appliances are environmentally dangerous, it is desirable to prevent their harmful release.
Recycling capabilities provide a financial benefit for technicians who generally filter and reuse refrigerant instead of replacing it with relatively costly new refrigerants. Containment and recycling is also economically beneficial to the technician who recovers the refrigerant from refrigeration units which are beyond repair.
Unfortunately, the environmental and economic advantages of recycling refrigerant must compete with the temptation of simply releasing the refrigerant into the atmosphere. In light of this conflict, any successful recover or recycling system must provide repair personnel with an easy to use apparatus that encourages the recycling of the refrigerant in comparison to the easier course of merely releasing the refrigerant into the atmosphere.
Refrigerant recovery processes taught in the Prior Art have focused on the use of molecular sieves and silica gels, products which are expensive to purchase, and while re-usable, require the application of heat during the regeneration process. This step of heating adds significant costs to the economics of the process, and often adds to the temptation to simply discard the molecular sieves or silica gel, with associated appropriate environmental disposal concerns.
Venturi devices have found application in fluidized bed food freezers in which the refrigerant is turbo expanded air, and in which the refrigerant is circulated by a venturi-like device such as an ejector as patented in U.S. Pat. No. 5,438,845. Variable volume venturi devices have also been described as air induction inputs for air conditioning system. Each unit in this configuration was described as including a round inlet collar, an elongated plenum to form a venturi, hinged volume dampers, secondary air openings, bottom plenum chamber and a pattern controller and patented in U.S. Pat. No. 4,448,111.
More traditional uses of a venturi reside in the gas scrubber field, when used to remove particulate matter from a gaseous effluent stream, as for example in the following U.S. Pat. Nos. 5,279,646; 4,140,501; 4,057,602; 4,012,469; 3,998,612; 3,898,308; 3,690,044; 3,638,924; and 3,616,613.
To date, there still exists a need for a cost-effective technology which can purify gas streams, particularly refrigerants, which contain water vapor or oil contaminants or both, which capitalizes on venturi design, yet which is easy to operate without the need for heat-intensive regeneration procedures.
SUMMARY OF THE INVENTION
The present invention is directed to a novel apparatus and method for recovering, purifying and recycling gases, particularly refrigerants, which utilize the venturi and Joule-Thompson effects, in contrast to the use of molecular sieves and/or silica gels. When using the apparatus of this invention and depending upon the location of the purification cells, either upstream or downstream of the compressor, both water and/or acid and oil, are removed from the refrigerant gas(es) as well as non-condensables. The invention will utilize a plurality of impingement surfaces which aid in the coalescence of various condensable contaminants from the gas stream, for eventual recovery.
These and other objects of this invention will be evident when viewed in light of the drawings, detailed description, and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may take physical form in certain parts and arrangements of parts, a preferred embodiment of which will be described in detail in the specification and illustrated in the accompanying drawings which form a part hereof, and wherein:
FIG. 1 is reaction schematic of the recovery/purification unit showing several venturi cells connected in series;
FIG. 2 is an elevational view schematically illustrating one configuration for a venturi cell;
FIG. 3 is an elevational view schematically illustrating a second configuration for a venturi cell;
FIG. 4 is an elevational view schematically illustrating a third configuration for a venturi cell;
FIG. 5 is an elevational view schematically illustrating a fourth configuration for a venturi cell;
FIG. 6 is an elevational view schematically illustrating a fifth configuration for a venturi cell; and
FIG. 7 is a elevational view schematically illustrating a modification of the view shown in FIG. 2 showing the venturi cell with a closed bottom and a plurality of apertures for the inflow of gas.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
This invention will now be described in detail with referenced to preferred embodiments thereof. Throughout the specification, including the claims, compositions are given in percent by weight unless the contrary is expressly stated.
With reference to FIG. 1, an overall reaction schematic sequence is shown for the processing and purification of a gas, e.g., refrigerant, such as R-12 (dichlorodifluoromethane). In this instance, the refrigerant which has become contaminated with non-condensables or water or acidic materials, or combinations thereof is shown within cylinder 6 prior to entry into cylinder 10 via solenoid valve 8, said cylinder 10 having a vapor side 12 and a liquid side 14 with a dip tube 16 therein and a cylinder or tank heater 18 disposed at the bottom of the cylinder or tank. The vapor side 12 of the cylinder receives gaseous refrigerant for transfer into the inlet side 20 of at least one venturi cell 22a/b/c/d. These cells have outlet side 24 and a drain plug 34 at the bottom, for removal of any accumulated condensed water vapor which is removed from the refrigerant. The venturi 28a/b/c/d within the venturi cell can assume various configurations as will be discussed below. In one embodiment of the invention, the venturi will have a bottom half 30 which is capable of receiving the refrigerant through an opening disposed therein and an upper half 32, the upper half being essentially closed at the top with an outlet 24 for refrigerant for passage to a compressor 36, an oil separator 38, a condenser 40 and ultimately returning to the holding cylinder 4 with pumping 3 to the recovery cylinder 2. Optionally, sight glasses 42 and a valve 44 are interposed in the refrigerant path.
FIG. 2 illustrates one embodiment of the venturi cell 22a which is used in the refrigerant purification and processing. In this configuration, the venturi cell itself is positioned within a housing, preferably cylindrical 46 into which is positioned two conic segments 48 and 52. The first conate segment 48 is open at a base 72 of the segment, thereby permitting the ingress of refrigerant 64 into, and closed at its apex 74. The second conate segment 52 is a frustoconical segment which joins the first conate segment 48 at a region 50 between the apex and base of this first conate segment. The second conate segment is closed at its base 78 and closed at the frustum 76 at which region 50 it is attached to the first conate segment 48. Refrigerant therefore, enters the first conate segment 48 and proceeds into the second conate segment 52 by egress through at least one aperture 58, preferably more than one aperture, in the first conate segment above the attachment region 50 and the apex 74 of the first conate segment. The size of the apertures coupled with the flow rate of the refrigerant will create a pressure drop between the first and second conate regions, thereby causing a decrease in the temperature of the refrigerant as it passes from the first to the second conate region by the Joule-Thompson effect, the inherent cooling of a gas as it expands from a region of higher pressure into a region of lower pressure. This cooling effect will also cool both the interior and exterior walls of the second conate region at a location adjacent to and above the attachment region 50, thereby permitting and facilitating condensation of condensables residing within the refrigeration stream.
In order to maximize the venturi effect within the venturi cell, it is preferred, although not required, that the inlet side 20 be directed toward a top of the venturi cell by an angularity α of the inlet into the venturi cell 22. Preferably, the angle α is less than 90°, and more preferably, is less than 45°. An angle of 37° has been found to work satisfactorily, although the preferably degree of angularity of this inlet stream is believed to be dependent upon the flow rate of the refrigerant stream as well as the geometry of the first and second conate sections. In order to facilitate the swirling pattern within the venturi cell, a pair of wings 60, 62 are affixed to the base of the second conate section. It is believed that a maximal configuration will have a differing lengths for the wing extensions. The swirling pattern is maintained in the second conate segment by positioning of the egress tube 24 at one side of the base of this segment as well as the positioning of the egress apertures toward the apex of the first conate segment. The venturi cell will optionally have shut-off valves 66, 68, 70 to stop the flow of refrigerant and condensables as they may be removed from the venturi cell through drain tube 34. Non-condensable vapors (e.g., acid gases) are removed via tube 92 into collection vessel 94.
FIG. 7 illustrates a variation of the embodiment shown in FIG. 2, wherein the first conate segment 48 is closed at its base 72 of the segment, thereby requiring the ingress of refrigerant into the conate segment through at least one and preferably a plurality of apertures 65, suitably positioned near the base of the segment.
In FIG. 3, a modification of the venturi cell shown in FIG. 2 is shown. This venturi cell 80 has a first frustoconical segment 82 which is open at its base and a second inverted frustoconical segment 84 which is closed at its base 90, the two conical segments attached at a neck attachment region 86 which is at the apex of the two frustoconical segments. In operation, the refrigerant will enter the venturi cell through inlet 20 and be directed toward a top of the venturi cell by an angularity α of the inlet into the venturi cell 80. Preferably, the angle α is less than 90°, and more preferably, is between 20-70°. A more preferred angle of 30-45° has been found to work satisfactorily, although the preferably degree of angularity of this inlet stream is believed to be dependent upon the flow rate of the refrigerant stream as well as the geometry of the first and second conate sections. The first frustoconical segment 82 is open at its base thereby permitting the inflow of refrigerant 88 through its base. At the neck attachment region 86, the narrow dimension of the neck limits the flow between the first frustoconical region 82 and the second frustoconical region 84, thereby creating a pressure differential between the two regions, this differential being proportionate to the flow rate of the refrigerant gas being passed through the cell. As the refrigerant gas passes through this neck region 86 and expands into the second conical segment 84, the refrigerant will decrease in the temperature due to the Joule-Thompson effect, the inherent cooling of a gas as it expands from a region of higher pressure into a region of lower pressure. This cooling effect will also cool both the interior and exterior walls of the second conate region 84 at a location adjacent to and above the neck attachment region 86, thereby permitting and facilitating condensation of condensables residing within the refrigeration stream through drain tube 110 with associated shut-off valve 108. While the outlet side of the venturi cell 80 is generally toward one side of the second frustoconical segment 84, it need not be so positioned, as shown in FIG. 3, wherein this exit tube 24 is positioned at approximately the middle of the base 90 of the second frustoconical segment. Optionally, a noncondensable removal tube 92 is positioned toward the top of the housing 46 to permit collection and removal of noncondensables which are contained within the refrigerant stream. In one specialized embodiment, the venturi effect will be supplemented by a second refrigerant flow stream supply 96 which enters the first frustoconical segment near its open-ended base 98 through shut-off valve 106 and exits near the close-ended base 90 of the second frustoconical segment 100 through shut-off valve 104 and second refrigerant return exit tube 102. In a preferred embodiment, and to provide additional fine-tuning of the recovery and purification system, a heater 112 is positioned at the base of the housing for temperature control if needed.
In FIG. 4, a modification of the venturi cell shown in FIG. 3 is shown. This venturi cell 114 has a first frustoconical segment 82 which is open at its base and angled with respect to a longitudinal axis of the cell, and a second inverted frustoconical segment 84 which is closed at its base 90, the two conical segments attached at a neck attachment region 86 which is at the apex of the two frustoconical segments and having a degree of angularity β as measured along a longitudinal axis of the cell. Preferably, this angle β is between 5-80° inclusive, and more preferably, between 20-60° inclusive, and most preferredly, between 40-50° inclusive. In operation, the refrigerant will enter the venturi cell through inlet 20 and be directed toward a top of the venturi cell by an angularity α of the inlet into the venturi cell 114. Preferably, the angle a is less than 90°, and more preferably, is between 20-70°. A more preferred angle of 30-45° has been found to work satisfactorily, although the preferably degree of angularity of this inlet stream is believed to be dependent upon the flow rate of the refrigerant stream as well as the geometry of the first and second conate sections. The first frustoconical segment 82 is open at its base thereby permitting the inflow of refrigerant 88 through its base. At the neck attachment region 86, the narrow dimension of the neck limits the flow between the first frustoconical region 82 and the second frustoconical region 84, thereby creating a pressure differential between the two regions, this differential being proportionate to the flow rate of the refrigerant gas being passed through the cell. As the refrigerant gas passes through this neck region 86 and expands into the second conical segment 84, the refrigerant will decrease in the temperature due to the Joule-Thompson effect, the inherent cooling of a gas as it expands from a region of higher pressure into a region of lower pressure. This cooling effect will also cool both the interior and exterior walls of the second conate region 84 at a location adjacent to and above the neck attachment region 86, thereby permitting and facilitating condensation of condensables residing within the refrigeration stream through drain tube 110 with associated shut-off valve 108. While the outlet side of the venturi cell 114 is generally toward one side of the second frustoconical segment 84, it need not be so positioned, as shown in FIGS. 3-4, wherein this exit tube is positioned at approximately the middle of the base 90 of the second frustoconical segment. In one specialized embodiment, the venturi effect will be supplemented by a second refrigerant flow stream supply 96 which enters the first frustoconical segment near its open-ended base 98 through shut-off valve 106 and exits near the close-ended base 90 of the second frustoconical segment 100 through shut-off valve 104 and second refrigerant return exit tube 102.
In FIG. 5, yet another modification of the venturi cell is shown. This venturi cell 116 has only a single conate segment 82 which is open at its base. In operation, the refrigerant will enter the venturi cell through inlet 20 and be directed toward a top of the venturi cell by an angularity α of the inlet into the venturi cell 116. Preferably, the angle α is less than 90°, and more preferably, is between 20-70°. A more preferred angle of 30-45° has been found to work satisfactorily, although the preferably degree of angularity of this inlet stream is believed to be dependent upon the flow rate of the refrigerant stream as well as the geometry of the first and second conate sections. The conical segment 82 is open at its base thereby permitting the inflow of refrigerant 88 through its base. At the apex of the conical segment 87, the narrow dimension of the neck, which is at least slightly smaller than that of the internal diameter of exit tube 24, limits the flow into exit tube 24, thereby creating a pressure differential between the conical segment 82 and exit tube 24, this differential being proportionate to the flow rate of the refrigerant gas being passed through the cell. As the refrigerant gas passes through this apical neck region 87, it partially expands and thereby lowers temperature of the refrigerant due to the Joule-Thompson effect, the inherent cooling of a gas as it expands from a region of higher pressure into a region of lower pressure. This cooling effect will also cool the interior and exterior walls of the conate region 82 at a location adjacent to and above the apical neck region 87, thereby permitting and facilitating condensation of condensables residing within the refrigeration stream through drain tube 110 with associated shut-off valve 108. In one specialized embodiment, the venturi effect will be supplemented by a second refrigerant flow stream supply 96 which enters the conate segment 82 near its open-ended base 98 through shut-off valve 106 and exits near the apical neck region 87 via return 100 through shut-off valve 104 and second refrigerant return exit tube 102.
In FIG. 6, still yet another modification of the venturi cell is shown, especially useful on the supply side of the compressor. In this configuration, the venturi cell itself is positioned within a housing, preferably cylindrical 46 into which is positioned various conical segments. A lower outer conic segment 122 is sealingly positioned within a lower interior conic segment 124, preferably having an inner circular opening 130 which extends beyond an outer circular opening 132. Refrigerant enters into the venturi cell 120 via inlet 20, which bifurcates into a first inlet segment 142 which is directed upwardly within the cell and a second inlet segment 144 which penetrates into the lower chamber formed between the first and second lower conate segments at the exit port 146 of the second segment. Most of the refrigerant flow from the second inlet segment is directed in a downward pathway in this lower chamber, with a portion being directed into at least one, preferably two or more perforations 140 near an apex of the inner conate segment.
The upper conate segment within the venturi cell is also comprised of various conical segments. An upper outer conic segment 126 is a frustoconical segment which joins with the lower outer conate segment 124 at a region 138 between the apex and base of this lower outer conate segment. The second conate segment is closed at its base 162 and closed at the region 138 at which region it is attached to the lower outer conate segment 124. Entirely disposed within the upper outer conate segment 126 is an inner frustoconical conate segment 128 with a closed base 160 and an inverted top 180 in sealing engagement with a protruding conduit 148 in communication with an opening at the apex of the lower inner conate segment 122. This conduit allows passage of the refrigerant gas from the interior region 176 of the cell through the lower inner conate segment 134 and into the upper interior conate segment 128 for impingement of the gas onto impingement dam 150 after egress through at least one exit port 168. The impingement dam will optimally have a protruding tip 152 with a laterally extending arm 154 and a vertically extending arm 156 for maintaining a swirling gaseous pattern as well as facilitating the liquid removal from the gas stream.
An upper entry conduit 158 permits passage of the refrigerant gas into the upper chamber defined between the upper inner and outer conate segments for eventual egress through exit 24. In a preferred embodiment, at least a portion of the upper chamber will contain a filter material 166, suitable for oil removal from the refrigerant stream. Inner liquid removal conduit 170, positioned within the inverted top of the inner conate segment 128, and outer liquid conduit removal conduit 172. positioned near sealing region 138, allow for the removal of any accumulated liquid(s), either oil or condensed water vapor, as well as lower liquid conduit 174.
In order to maximize the venturi effect within the venturi cell, it is preferred, although not required, that the inlet side 20 be directed toward a top of the venturi cell by an angularity α of the inlet into the venturi cell 22. Preferably, the angle α is less than 90°, and more preferably, is less than 45°. An angle of 37° has been found to work satisfactorily, although the preferably degree of angularity of this inlet stream is believed to be dependent upon the flow rate of the refrigerant stream as well as the geometry of the first and second conate sections.
Without being bound to any one particular theory of operation, it is believed that hot refrigerant vapor and oil enter the venturi cell via inlet tube 20 with bifurcation into two separate streams. The vapor which is released through conduit 142 enters the interior of the cell with minimal resistance and will be the primary discharge location. Impingement of the refrigerant will be onto the exterior wall of the upper outer venturi segment 126 and will raise the temperature of this impinged portion of the segment, typically in proximity to that which contains the filter medium 166. The hot oily vapor will decrease in temperature due to a combination of the Joule-Thompson effect coupled with the lower exterior venturi cell wall temperatures. This cooler refrigerant gas initially released from conduit 142 will recombine with the bifurcated refrigerant gas which exited through conduit 146 into the lower chamber 136 between the lower two conate segments, 122,124 and enter the lower inner conate segment 122 through opening 130 as shown at 134, thereby reheating the refrigerant gas which was in the interior 176 of the venturi cell, the temperature in this lower chamber region being between 4-15° F. hotter than that within the interior of the lower conate segment 122. As the refrigerant vapor moves through the inner conate segment, it is impinged and still further reheated by the at least one, and preferably more than one perforation in the upper region of the inner conate segment, for which at least a portion of the refrigerant gas which flowed through segment 144 and port 146 will pass thereby creating turbulence in the upwardly flowing refrigerant stream. This refrigerant stream passes through at least one opening 168 in protruding conduit 148 under pressure (i.e., 115-125 psig) striking dam 150. In this low-pressure area of the cell, oil that was missed prior to this chamber is now collected and the cooled refrigerant enters conduit 158 for passage into the upper chamber between the inner 128 and outer 126 upper conate segments. In a preferred embodiment, this chamber will contain at least a portion of a filter media, (e.g., a gas line filter media) to aid in the oil separation. Due to the impingement angle α, this refrigerant gas will be reheated and egress via exit line 24. Recovered oil is returned back to the compressor by a solenoid valve 178 which is activated in a definable timing sequence.
In one alternative embodiment of the invention of the configuration described in conjunction with FIG. 6, it is recognized that a temperature sensitive solenoid valve could be added into protruding conduit 148, thereby maximizing the Joule-Thompson effect, by assisting in the development of a higher pressure on one side of the venturi cell which is prior to the constriction device, e.g., protruding conduit 148 or the apertures 168. Upon the sensing of a predefined temperature, the solenoid valve would open, thereby permitting flow through the apertures 168 in a pulsed manner.
In another aspect of this invention, it is seen that what has been described in this invention is the application of a venturi cell design which has a plurality of impingement surfaces which aid in the coalescence of various condensable contaminants in the gas feed stream. These impingement surfaces can be the lower conate segment 122, or the upper outer conate segment 126, or similarly configured surfaces.
EXAMPLE
A venturi arrangement as described in FIGS. 1-2 was constructed and arranged and tested using R-12 (diclorofluoromethane) at a flow rate of 8 oz./min, the refrigerant initially being loaded to a level of 35 ppm by weight water. The system was tested at various pressures, not optimized, as indicated in the Table. It is clear that it was possible to reduce the amount of water vapor contained within the refrigerant through the use of the above described system.
TABLE I______________________________________R-12 Refrigerant (Dichlorodifluoromethane) 20-32 15-26 1-9Composition Initial psig psig psig______________________________________High Boiling Residues 2.23 .03 .02 <.01(% by volume)Water (ppm by weight) 35 20 11 24______________________________________
The testing was conducted in accordance with Appendix 95 of ARI Standard 700. The results are for a single pass through a single Venturi unit at the identified three different pressure ranges supplied to the inlet of the unit.
This invention has been described in detail with reference to specific embodiments thereof, including the respective best modes for carrying out each embodiment. It shall be understood that these illustrations are by way of example and not by way of limitation. | This invention describes a process for the purification of a refrigerant gas by feeding the refrigerant through at least one venturi cell. In one configuration, the venturi will have a first conical segment with an open base through which said refrigerant gas can enter, and a second conical segment which is connectedly affixed to the first conical segment in a leak-proof manner and in communication with the segment to permit refrigerant gas flow therethrough in addition to a configuration that creates a pressure differential between said first and said second conical segments. There can be more than one venturi cell depending upon the degree of purification required for the refrigerant gas. | 1 |
BACKGROUND OF THE INVENTION
The present invention concerns a metering pump for liquid products.
PRIOR ART
Notably two types of devices for precision metering of liquid products are known, viz., the motorized gear pump and the flowmeter with flow rate controller. These two types of devices have problems, particularly when there is a need for rather rapid change of the liquid product being metered, as for instance in robotized installations for car body painting. It is necessary, in fact, when the product to be metered is rapidly changed, that the metering device is able to be rapidly and easily rinsed in such a way that during metering of a given product not a particle of the previous product be left in the metering device. The two known types of devices have problems of rinsing caused by difficult access for the rinsing or cleaning product or by idle spaces where the product to be eliminated may persist as a film or lump. On the other hand, rinsing that is not optimized will lead to a larger consumption of the product as well as to a longer duration of acceptable rinsing.
It is generally admitted that the gear pump represents the more reliable and more precise metering device, but is also the metering device that is more difficult to rinse in an appropriate manner. A gear pump of the type considered here comprises at least one driving gear and one driven gear, said gears each being held on a shaft mounted on bearings located in the pump body. These bearings give rise to idle spaces difficult to rinse and apt to retain pumped product that is degraded, crystallized or hardened. One way to avoid such idle spaces is that of arranging packing seals on each bearing, which means a minimum of four packings per pump. These packing seals are expensive, generally require some maintenance, and are always susceptible to leak.
The document JP 04 041 984 describes a gear pump in which the two gears are guided by the outer peripheral surface of friction teeth sliding on an inner peripheral surface of the pump chamber. While the problems mentioned above are partly eliminated by elimination of the gear shafts, the driving gear of this device is set in rotation by a shaft that is rigidly mounted. This has the particular disadvantage of dictating the lateral position of the driving gear, which necessitates a larger pump chamber and hence additional idle lateral spaces that are difficult to rinse.
The patent FR 2 163 935 describes a gear pump in which the driving gear is rotated by a driving shaft fixed in a manner to transmit only a rotation torque, the driven gear comprising no support shaft. The driving shaft of this pump does not comprise a packing seal, the sealing being made by a layer of the pumped liquid. Such disposition does not facilitate the rinsing of the pump and causes difficulties to use in the case of frequent changes of the pumped liquid.
The packing described in DE 14 03 912 can under no circumstances be suitable for a pump as proposed here, as it is adapted to a pump having the driving heat rigidly fixed to the driving shaft, being disposed between two bearings supporting the driving shaft.
It is a first aim of the invention, therefore, to propose a metering pump for liquid products improved over known metering pumps.
It is a further aim of the invention to propose a metering pump having a rinsability distinctly improved over that of known pumps.
Still another aim is that of proposing a metering pump that is able to meter a volume of liquid in precise manner.
These different aims are attained by a metering pump for liquid products having the characteristics disclosed herein.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferential embodiment of a metering pump for liquid products is described below, the description to be considered while referring to the annexed drawing comprising the figures in which
FIG. 1 presents a lateral view along a first section of a metering pump for liquid products according to the invention,
FIG. 2 presents the same pump along a section in a plane perpendicular to the plane of the section of the preceding figure,
FIG. 3 presents the constituent elements of a metering pump in a schematic way.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows that the body 1 of the pump comprises a bottom plate 10 , an intermediate plate 11 and a front plate 12 , these three plates here having an essentially rectangular external shape and similar dimensions, which are superimposed as can be seen in the figure. Means of attachment schematically shown at 13 hold these three plates assembled. A seal not shown in the figure secures tight sealing of the contacting faces of these three plates.
The intermediate plate 11 seen in elevation in FIG. 2 essentially consists of a plate, rectangular in this embodiment, which comprises a chamber 110 consisting of at least two lobes each able to receive a gear 30 , 31 of a set of gears 3 . One can see in FIG. 1 that in the embodiment of the pump represented, chamber 110 reaches entirely across the intermediate plate 1 . The intermediate plate 11 additionally comprises an entry channel 111 for liquid that ends in the chamber 110 , as well as an exit channel 112 for liquid that leaves said chamber. The openings of these channels can each be arranged on one of the lateral walls of the intermediate plate 11 , as shown here, or channels 111 and/or 112 may be extended into either the bottom plate 10 or the front plate 12 while their openings would be located on a periphery of these plates.
The pump additionally comprises a set of gears 3 comprising a driving gear 30 and at least one driven gear 31 as well as drive organs 4 and packing seal 5 .
The drive organ 4 comprises a motorized organ not represented in this figure which ends in a drive shaft 40 that goes through a bearing 120 set in the front plate 12 . The bearing 120 can be a sliding bearing as shown here or a roller bearing. The end 41 of shaft 40 has a shape such that it can be introduced into a recess 300 of the gear 30 of corresponding shape so that it will be able to rotate said gear. In the case represented here, the end 41 and the recess 300 are both hexagonal, but any other shape allowing a rotating drive could be suitable.
One notices in the figure that the gears 30 and 31 are not supported by any shaft, they are guided while rotating, solely by the outer peripheral surface of the teeth in sliding contact on the inner periphery of the lobes of chamber 10 . The lubrication of the surfaces moving relative to each other is assured by the product being pumped. The shaft 40 that is flexibly connected with the driving gear 30 at its end 41 only serves to drive said gear while being without any support or guiding function. The shaft 40 or its end 41 can hence only transmit a torque to the driving gear 30 while any other force in whatever direction is excluded. Since the gears 30 and 31 are no longer guided laterally by a shaft, they can now settle laterally under the effect of pressure of the product being pumped, which acts on their sides. It is thus possible to have a lateral space to both sides of each gear that is as small as feasible, provided a thin sheet of the pressurized product is present that will secure lateral centering of the gear in its lobe. In this way the hollow spaces which would have to be rinsed between two products being pumped are strongly diminished, and only a single set of packing seals 5 has to be fixed on the shaft 40 .
In known manner, the packing seal 5 can consist of packings, of lip seals or, as shown here, of a mechanical lining. The mechanical lining has the advantage over other known types of packing seals, of exhibiting the smallest frictional force in rotation. Therefore, preferably a mechanical packing is selected which consists of a sealing ring 50 freely mounted around the shaft 40 and able to move axially in a recess 121 in bearing 120 while being pressed against the front side of gear 30 by an elastic organ, for instance a spring 51 , in order to mechanically secure a tight seal between the chamber 110 and the shaft 40 . An O-ring 52 serves as a static sealing barrier in the rear of the sealing ring 50 . Means represented in the figure at 55 allow rotation of the sealing ring to be prevented. Relative to known designs, that of the packing seal 5 here described allows the sealing barrier to be as close as possible to the end 41 of shaft 40 , which substantially contributes to a reduction of the hollow spaces that must be rinsed between two products being pumped. It has been mentioned before that the gear 30 was positioned laterally by the equilibrium of the pressures being exerted on its two sides. Since the side of gear 30 that is linked as described to the shaft 40 is lower than the opposite side, gear 30 would tend to be pressed against the inside of the front plate 12 . The elastic organs 51 will therefore be of a size such that they exert a force able to compensate the difference between the opposing forces being exerted on the two opposite sides of gear 30 .
Optionally, the packing seal 5 described above is made more complete by a supply 53 of a packing liquid coming from an external reservoir 54 . The packing liquid fills the part of recess 121 on the side of O-ring 52 that is opposite to that in contact with the liquid being pumped, and thus exerts a counterpressure on this seal so that its sealing will be improved. A leak of packing liquid in the direction of chamber 110 or a leak of pumped liquid across the seal 52 would lead to a change in level of the packing liquid in the reservoir 54 . By monitoring this level it is therefore possible to detect liquid leaks at the packing seal in any one direction. The presence of a packing liquid in the hollow parts of recess 121 also prevents a condensation and crystallization of the pump ed liquid in these hollow parts.
The gear metering pump as described above is thus optimized so as to substantially improve its rinsability, by eliminating the hollow spaces to be rinsed between two different p products being pumped d, which leads to savings of both the rinsing product and rinsing time. The simplified pump design which uses a smaller number of pump components and requires just a single packing seal reduces by as much the manufacturing cost as well as the risk of leaks, and improves its reliability.
The above pump can advantageously be used to meter a product being pumped, the volume of product pumped being essentially proportional to the number of revolutions of gear 30 or 31 . By monitoring this number of revolutions it is possible, therefore, to obtain a precision metering pump. Such a pump is presented schematically in FIG. 3 .
One recognizes in this figure the pump body 1 with the driving gear 30 being driven by the shaft 40 as described previously. The other end of shaft 40 is driven by a motor 41 , which preferably is an electric motor but can also be a pneumatic or hydraulic motor or a motor of any other known type able to drive the shaft 40 . A reducing gear or gear box 42 can be arranged on the shaft 40 between the motor 41 and the pump. The rotating speed of gears 30 and 31 of the pump or the volume of liquid pumped are thus equal or proportional to the number of revolutions of shaft 40 as well as of motor 41 . An encoder 43 able to record this number of revolutions can thus send a control signal to a control unit 44 , for instance an electronic unit containing or not containing a programmed microprocessor and able to record this signal and regulate the pumping process, e.g., by cutting the power supply to the motor 41 when the desired quantity of product has been pumped. The encoder can be arranged at the end of the shaft on motor 41 , as shown schematically by the encoder 43 in position A, on shaft 40 in front of or behind the reducing gear 42 , if present, as shown schematically in positions B and C, or in the pump itself, as shown schematically at position D. The encoder 43 is of any known type, optical, inductive, capacitive or other, that is able to record the number of revolutions of the motor 41 , of the shaft 40 or of one of the gears 30 or 31 , depending on the position (A, B, C, D) where it has been installed.
The design of the metering pump can be compact, with the motor 41 being directly glued to the pump body 1 , or more distributed, with a shaft 40 that consists of a flexible drive shaft. Such a pump is advantageously mounted on a robotic painting arm, for instance in the painting of car bodies, where the pump together with its drive motor can be located in the mobile part of the robotic arm or, if one wants to minimize the moving masses, the motor 41 can be housed in a part of the base of the robotic arm while the pump body can be located in the mobile end of the arm, while the two elements are linked by a flexible shaft 40 . A distributed design with flexible or rigid drive shaft 40 can also be used in order to obtain an explosion-proof pump where the motor 41 that might produce sparks can be remote from the pump body I that could be located in an explosive atmosphere.
In each of the possible applications of such a metering pump, it will be determined by the application considered whether or not a reducing gear or gear box 42 are incorporated, and where the encoder 43 will be placed among any of the positions described above.
The modular design described allows such a metering pump to be employed in numerous applications, painting, metering of chemical products, food products, pharmaceuticals, etc.
The constituent elements of the pump body 1 as well as the gears 3 and the packing seal 5 are made of materials which essentially are compatible with the products being pumped, and which can be metals or alloys, for instance stainless steel, synthetic materials, or ceramics, and these materials may be uncoated or coated with a protecting layer. It is not necessary that the different constituent elements of the pump be made of the same material.
A variety of different versions can be envisaged for the design of a gear metering pump according to the invention. The pump has been described as having one driving gear and one driven gear; it could just as well comprise a number of driven gears arranged along the periphery of a driving gear. The chamber of the pump body would then have the number of lobes required to receive one gear each. The pump body has been described as consisting of three assembled plates, so as to facilitate machining of the chamber 110 of the intermediate plate. It would also be possible for the intermediate plate 11 to be made as a single piece together either with the bottom plate 10 or the front plate 12 . Also, the pump body 1 has been described as being of rectangular shape, but it actually could have whatever shape able to accommodate a pumping chamber such as that described. On the other hand, the metering pump has been described as comprising an electric motor and an encoder, in particular. These two elements could be replaced by a step motor, where the number of steps to be executed is determined by the volume of product to be pumped. | The invention concerns a metering gear pump comprising a set of gears supported and guided solely by the inner peripheral surface of the lobe of the chamber wherein they are housed. They do not comprise any shaft to act as support or guide, thereby enabling to reduce significantly useless spaced difficult to rinse when changing the product to be pumped. For the same purpose, the driving shaft is flexibly connected to the driving gear. Such arrangement provides the advantage of requiring only one single packing seal. Such a pump, connected to a drive motor and an encoder delivering a signal proportional to the number of pump cycles, enables to provide an accurate metering pump for numerous uses. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to curved handles for manually operated implements such as mops, brooms, paint applicators, reach rods, and a variety of other handheld tools. The invention provides a handle which is not only ergonomically shaped for maximum efficiency, but is also configured to allow cleaning members and other working elements to be attached to either end of the handle for effective use in different cleaning and other functional modes.
Most implement handles are substantially straight in design and, as a result, so are the majority of brooms, mops, applicators and other implements employing elongated handles. Over the years, handles have been provided which contain some degree of curvature, as exemplified by U.S. Pat. Nos. 6,203,626, 6,487,747, U.S. Des. Pat. Nos. D413,234, and 433,890, or more drastic curved configurations which are purportedly designed to enhance appearance or provide the user with an ergonomic advantage, e.g. U.S. Pat. Nos. 2,753,579 and 5,791,006. However, many of these prior art handles do not accomplish the results claimed for the variety of potential users. In addition, such handles are often difficult to manufacture and they are cumbersome when it comes to storage of the implements. Existing handles also do not provide the option of connecting different working attachments at both ends of the handle for efficient and ergonomic use in different use positions.
SUMMARY OF THE INVENTION
It is thus the object of the present invention to provide a curved handle for a manually operated implement which overcomes the disadvantages and limitations of prior products.
It is an object of the present invention to provide a curved handle for a manually operated implement which permits the connection of different attachments to either working end of the handle, to allow efficient, effective, and ergonomic use of the implement in different working modes.
It is a further object of the present invention to provide a curved handle for a manually operated implement which is highly efficient in use regardless of which end of the handle has a working attachment secured thereto.
It is still another object of the present invention to provide a curved handle for a manually operated implement which is easy to manufacture and convenient to store.
It is another object of the present invention to provide a curved handle for a manually operated implement which has two working ends and, as a result, has the flexibility to be used both on horizontal, vertical and elevated surfaces.
It is a further object of the present invention to provide a curved handle for a manually operated implement which assists in relieving the user of the common back strain caused by manual implements with prior art handles.
These and other objects are accomplished by the present invention, a uniquely configured curved handle for manually operated implements. The handle has a straight segment extending to a first curved segment having a uniform radius of curvature and a second curved segment having a different uniform radius of curvature, extending from the first segment. The handle has two working ends and a threaded connection on each end for securing various cleaning or other working members or attachments. This multi-use handle can thus be used in implements performing numerous different applications on horizontal, vertical and elevated surfaces.
The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The invention, itself, however, both as to its design, construction and use, together with additional features and advantages thereof, are best understood upon review of the following detailed description with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevation view of the curved handle of the present invention.
FIG. 2 is an exploded elevation view of a manually operated implement, a pushbroom, employing the curved handle of the present invention with a pushbroom head.
FIG. 3 is an elevation view of an assembled manually operated implement, a pushbroom, employing the curved handle of the present invention with a pushbroom head.
FIG. 4 is an elevation view of a prior art handle secured to a cleaning attachment, a pushbroom head.
FIG. 5 is a cross-section view taken from FIG. 1 .
FIG. 6 is a cross-sectional elevation view showing the manner of locking connection between the handle of the present invention and a working attachment such as a pushbroom head.
FIG. 7 is an elevation view, in partial section, showing the sleeve and cover at the end of the handle of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Handle 1 of the present invention comprises an integral, solid, unbendable elongated shaft 2 having first working end 4 and second working end 6 . Threaded connector 8 , with threaded end 10 and multi-sided sleeve 12 , is located at end 4 and threaded connector 14 , with threaded end 16 and cylindrical sleeve 18 , is located at end 6 .
Handle 1 can be of a given length of any dimension convenient for use with a manual implement, such as a pushbroom or mop or other working tool, but it has been found that a length, excluding the length of connectors 8 and 14 , in the range of fifty to sixty inches to be the most ergonomic.
Significantly, handle 1 has substantially straight segment 1 a , extending from connector 8 at end 4 . Straight segment 1 a has length L which represents @ 15-20% of the overall length of handle 1 . The remaining length of handle 1 , from the terminus of straight segment 1 a to connector 14 , is a smoothly curved, continuously concave section. This curved section comprises first curved segment 1 b and second curved segment 1 c . Curved segment 1 b extends from the terminus of straight segment 1 a in a uniform radius of curvature R 1 (measured from C 1 , the center of the circle of R 1 ) for a distance of 40-60% of the overall length of the handle. Segment 1 b optimally has a uniform radius of curvature of approximately two times the length of the handle. Curved segment 1 c extends in a smooth curve from the terminus of segment 1 b for a distance of 30-35% of the overall length of the handle. Segment 1 c optimally has a uniform radius of curvature R 2 (measured from C 2 , the center of the circle of R 2 ) of approximately one-third the length of the handle. The primary longitudinal axis of segment 1 c approaches, but is not parallel to, the ground surface on which the working attachment to which the handle is to be connected is used.
For instance, an exemplar handle with an overall length of sixty inches, would have a straight segment 1 a with a length of approximately ten and a half inches, a curved first segment 1 b with a length of approximately thirty inches and a radius of curvature of 120 inches, and a curved second segment 1 c with a length of approximately nineteen and a half inches and a radius of curvature of seventy-eight inches. A handle of these dimensions is disclosed merely for illustrative purposes. The handle of the present invention is not to be considered restricted to these or correspondingly proportional dimensions.
Handle 1 has the versatility to be used with attachments at either working end 4 or 6 . FIG. 2 shows the components, pushbroom head 20 and locking nut 22 , which would be used when handle 1 is employed as a pushbroom at end 4 . It is contemplated that any type of attachment directed towards cleaning or other working application on a ground, floor or other horizontal surface, e.g. a floor squeegee, sponge or dust mop, roller mop, floor roller for applying adhesives and solvents etc., can be connected to end 4 .
FIG. 2 also depicts a cleaning or other type of working member or attachment, such as wall sponge 26 , configured to be secured at end 6 , to be used on vertical and elevated surfaces. Such attachments could include a wall squeegee, paint roller, sheetrock sander, scrub brush, and the like.
In the assembled pushbroom mode, shown in FIG. 3 , pushbroom head 20 is secured to handle 1 via threaded end 10 , shown in FIG. 6 , and locking bracket 38 . It is contemplated that locking bracket 38 would be similar to that which is described in U.S. Pat. No. 5,502,862. Locking nut 22 is provided to further secure the connection.
FIG. 5 , a cross-section of connector 8 taken from FIG. 1 , shows flat surface 28 on threaded end 10 . Locking nut 22 comprises threads 30 which screw into corresponding threads 32 in pushbroom head 20 . Bottom surface 36 of locking nut 22 is also flat. When threaded end 10 of connector 8 , configured to be screwed into corresponding threads 33 of pushbroom head 20 , is fully threadably secured within the head, locking nut 22 is subsequently screwed into the head such that its flat bottom surface 36 contacts flat surface 28 of the threaded end. Tightening locking nut 22 against flat surface 28 provides an added, significant locking feature between handle 1 and head 20 , which may be used with or without pushbroom locking bracket 38 . As a practical matter, tightening locking nut 22 onto flat surface 28 provides a necessary locking means which ensures for a stable handle to head connection, not otherwise available.
As best seen in FIG. 7 , removable connector cover 24 is cylindrical, corresponding to the cylindrical shape of sleeve 18 of connector 14 . Cover 24 has internal threads 25 which are configured to be threadably engaged with threaded end 16 of connector 14 to protect the threads and to provide for the comfort of the user. Compressible rubber or plastic O-ring 29 is positioned over the end of sleeve 18 , so that when cover 24 is tightened onto threaded end 16 , it squeezes O-ring 29 against the cylindrical sleeve, presenting a sealed and seamless fit. Base section of working attachment 26 configured to be secured to end 6 of handle 1 , has internal threading similar to cover 24 , so as to be threadably engaged against sleeve 18 and sealed via O-ring 29 .
Cover 24 comprises open hooked eyelet section 27 . Eyelet section 27 not only permits handle 1 to be hung for storage when a working attachment is secured to end 4 , but it also serves as a convenient hook component for reaching elevated areas where objects which otherwise may be out of reach can be retrieved.
The configuration of handle 1 , when employed on a pushbroom head or similar pushing implement, provides the user with an ergonomic tool which is quite effective in cleaning operations. As seen in FIG. 3 , the pushing force applied at end 6 is more efficiently directed forward and downward, due to the connection of pushbroom head 20 to straight segment 1 a and curved segments 1 b and 1 c . In addition, and importantly, the curved configuration of handle 1 provides significant help in relieving back strain of the user, who is now free to assume a more comfortable and normal pushing position by remaining straighter and more upright, as shown in FIG. 3 .
This is in contrast to the more awkward, fatiguing body position which is associated with straight handles. FIG. 4 shows the common, representative straight handle 40 in use. The straight, more upwardly extending nature of the handle serves to decrease the effect of the pushing action, making it more difficult for the user, and requiring additional pushing force from a higher, less comfortable, less natural angle. As a result the user must assume more of a crouching position to do the work, thus resulting in increased strain to the back.
As shown in FIG. 2 , located at end 6 of handle 1 is working attachment 26 which could be a wall sponge or brush, as discussed above, for cleaning vertical and elevated surfaces. Used in this mode, handle 1 is held around straight segment 1 a , which provides a ready handle portion, making it easier for the user to grasp and elevate handle 1 and working attachment 26 . Handle 1 , with its straight segment 1 a , thus provides a convenient and ergonomic straight handle portion, on handle 1 itself, to allow a user to easily hold and control the implement when it is to be elevated.
In addition, handle 1 of the present invention, when used on vertical and elevated surfaces, overcomes obstacles which straight handles do not address. The curvature of the handle creates increased leverage and thus allows for increased pressure on the work surface. The curvature also creates space between the user and the work surface. This is especially helpful when working overhead to keep debris from falling on the user, thus generally promoting a cleaner and safe work environment.
The disclosure herein, while it is directed to a handle with a shaft having a straight segment and two segments which comprise a smoothly curved, continuously concave section, is not to be considered as to be restrictive of the scope of the herein invention. For instance, depending on the desired angular curve on the handle, it is contemplated that the handle of the present invention may be configured with more than two curved segments with different radii of curvature, in order to make up the full length of the curved, concave section. The exact curvature or radius of curvature of each segment is also not to be considered limited to the herein disclosure.
Certain novel features and components of this invention are disclosed in detail in order to make the invention clear in at least one form thereof. However, it is to be clearly understood that the invention as disclosed is not necessarily limited to the exact form and details as disclosed, since it is apparent that various modifications and changes may be made without departing from the spirit of the invention. | A curved handle for a manually operated implement has a straight segment extending from a first curved segment having a uniform radius of curvature and a second curved segment having a different uniform radius of curvature extending from the first segment. The handle has two working ends and a threaded connection on each end for securing various working attachments or members. This multi-use handle can thus be used in implements performing numerous different applications on horizontal, vertical and elevated surfaces. | 1 |
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates generally to communications devices for the handicapped, and more specifically to an improved scanning process for use with lists and matrices.
Many attempts have been made to enable persons with motor and/or speech impairments to communicate more effectively with others. Methods presently in use generally employ one or more electrical switches coupled to an electronic control circuit. Closure of these switches by the user allows desired symbols or preselected phrases to be chosen and communicated to others. Typically, a keyboard of some type is coupled through control logic to a printer or lighted display.
Keyboards of any type have serious drawbacks in that they are not suitable for use by many handicapped or impaired persons. Although these persons may have good cognitive faculties, due to various physical impairments they are not able to accurately select and close the contacts on a keyboard matrix.
One alternative to the matrixed keyboard input is the use of a single switch, coupled with a dynamic presentation of the items to be selected. For example, a row or matrix of lights corresponding to letters of the alphabet or preselected messages can be individually, sequentially lighted. The user is then able to make his selection by closing the single switch while the desired item is being presented. This method has advantages in that it is inherently very simple to use and understand by anyone who is able to manipulate a single switch.
However, such a method has a serious drawback in that selection of individual items can be extremely time consuming. Each item must be presented for a long enough time period to insure that the user will be able to comprehend that his desired item is being presented, and make the necessary switch closure. For most impaired persons, such a period runs several seconds, and may run several tens of seconds for some. If an item must be selected from a group or list of forty or more elements, it is easily seen that the element selection process may take several minutes. This is especially true when the user's attention wanders, causing him to miss the desired selection and requiring him to wait for the scanning process to return. This wandering of attention is an important problem, and is greatly exaggerated by the fact that the user must wait a long time for his selected element to be presented. Long delays cause boredom and frustration, and may sharply curtail the use of an otherwise helpful communication aid.
It would be desirable to provide a communications method and device which utilizes a dynamic scanning presentation of elements for selection by the user. It is further desirable that the element selection can be made by operating a single switch, and it is extremely desirable that the average selection time and quantity of switch operations per selection is kept to a minimum.
Therefore, according to the present invention, a method for dynamic scanning of lists or arrays comprises the steps of scanning through the list in a forward direction at a speed greater than the response time of the user, and, upon receipt of a switch closure, reversing direction and scanning at a slow speed, thereby allowing item selection upon a second switch closure by the user. The forward and reverse scanning speeds are preferably dependent on parameters established by the response abilities of the user.
It is preferable that a device constructed according to the present invention be able to interface with a variety of communications devices. Therefore, the present invention provides a general apparatus for providing the scanning and interpreting of switch closures, and allowing interfacing with a communications device to be selected by the user. Thus, modifications of the device disclosed in connection with the drawings can be used to interface the impaired user with a variety of electronic and microprocessor driven displays and devices.
The novel features which characterize the present invention are defined by the appended claims. The foregoing and other objects and advantages of the invention will hereinafter appear, and for purposes of illustration, but not of limitation, a preferred embodiment is shown in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of the method of the present invention;
FIG. 2 is a timing diagram corresponding to the method of FIG. 1;
FIG. 3 is block diagram of a device for scanning an array according to the present invention;
FIG. 4 is a diagram of a particular keyboard as used with a preferred embodiment of the invention;
FIG. 5 is a schematic diagram of the input and control logic for a preferred embodiment of the present invention;
FIG. 6 is a schematic diagram of an LED display and printer driving portions of a preferred embodiment of the present invention;
FIG. 7 is a diagram of a circuit for interfacing a keyboard scanner with an electronic switch selection circuit; and
FIG. 8 is a perspective view of a mechanical switch suitable for use by handicapped persons.
FIG. 9 is a perspective view of an alternative embodiment of the mechanical switch of FIG. 8 suitable for use by handicapped persons.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The method and apparatus of the present invention encompasses certain communications devices suitable for use by handicapped persons. The present invention is especially suitable for use by those who must use a non-speech form of communication and do not have the dexterity to operate a keyboard instrument efficiently. An instrument constructed according to the present invention can be used to interface the impaired person with nearly any device allowing him to communicate with others.
Linear scanning of the alphabet is a desirable way for the impaired individual to communicate with others. Use of the alphabet allows the individual to communicate without any limitations on the words he may use to express himself, a problem which is prevalent with the use of preselected vocabulary. The linear scanning concept is simple for the user in that each letter of the alphabet is presented sequentially to the handicapped individual, and he typically indicates his selection of the desired letter by closing a switch when that letter appears. After the selected letter is registered, the scanning process begins again and the individual selects the next letter. It will be appreciated that numbers and other symbols can be, and usually are, presented to the individual in addition to the alphabet.
Such a linear scanning technique is an extremely time consuming process. It will be appreciated that, in order to function properly, the sequential presentation of elements, which can be letters or other symbols, must be done at a rate which is slower than the response time of the impaired individual to ensure proper selection. If the scanning rate is too fast, the individual must try to anticipate when the desired element will be presented, and try to time his switch operation to coincide with such presentation. This is a highly inaccurate procedure at best. "Reliable response time" may be conveniently defined as that period of time in which the individual is virtually assured of being able to complete the selection process. This process includes the perception of the element (symbol) presently being displayed, the decision as to whether or not it is the element desired for selection, and the actual physical manipulation of a switch to indicate selection. For severely handicapped individuals, such as those with certain nervous or muscular disorders, the reliable response time may be fairly long. This can be the case even with persons whose intellectual capabilities are virtually unimpaired. A reliable response time of three to five seconds is not uncommon, and times of ten seconds or more are sometimes encountered. Since in many instances the attempt to have the individual anticipate the occurrence of his desired letter or symbol actually increases the reliable response time, due to distraction and other factors, it will become apparent to those skilled in the art that each element presented to the individual must be presented for a period of time at least as long as his reliable response time.
It will quickly become apparent that the selection of each symbol can be a time consuming process indeed. As a rough approximation of the average time required to select each symbol, it is safe to assume that the average number of symbols which must be passed before reaching the chosen one lies at approximately the midpoint of the number of symbols in the list. Thus, for a list of the alphabet, plus perhaps 8-10 additional symbols, it would be expected that, on the average, approximately fifteen symbols must be presented to the individual for each one that is selected. This assumes that the individual actually captures the selected symbol the first time around every time. Obviously, if this is not the case, the entire list must be scanned again prior to selection of a single symbol. If an average of fifteen symbols per selection is assumed, and the person's reliable response time is five seconds, it is seen that the average capture time per selection is 75 seconds, assuming no mistakes. Thus, such a linear scanning process is, at best, extremely tedious and time consuming.
Although it is possible to decrease the average selection time of the characters by placing the most frequently chosen characters toward the beginning of the list, it has been determined that presenting the symbols out of a known order, such as alphabetical or numerical order, creates confusion on the part of the user and is often counterproductive.
The present invention employs a two step sequential scanning process of a list or array of symbols which greatly improves the selection time per symbol over the linear scanning method. This improved scanning method will sometimes be referred to as "critically damped scanning". The method of the present invention is best described with relation to FIG. 1, which shows a string of lights 10 which are sequentially lighted. Each light corresponds to a letter of the alphabet, and they are individually lit in sequence beginning with A. In the present invention, the serial activation of the lights 10 corresponding to the letters of the alphabet occurs at a rate much faster than the reliable response time of the individual. For example, if the reliable response time is approximately five seconds, the lights 10 in FIG. 1 can be activated at one second intervals. When such a high speed scan is used, the individual looks at the target letter and attempts to operate a switch when his target letter lights up. Since the scan rate is faster than his response time, the light actually being presented at the time the switch is depressed will not be the selected letter. FIG. 1 shows a typical example in which the desired selection is the letter H, and activation sequence has moved on to the letter K by the time switch closure is actually made at point X 1 . The lighting sequence then reverses direction and sequentially lights the letters at a slower rate, which is determined by the reliable response time of the individual, and is the same rate as the linear scan discussed above. He is then able to close the selection switch a second time when the letter H is activated the second time, shown as point X 2 in FIG. 1.
A timing diagram of the selection procedure of FIG. 1 is shown in FIG. 2. Here, it is seen that the letters are presented in forward sequence at short time intervals t 1 . The switch operation to select the letter H actually takes place at a later time, in the case of FIG. 2 while the forward scanning process is on the letter K at point X 1 . At that time, the scanner reverses direction and presents each letter for a longer time interval t 2 , which is as long as the reliable response time of the individual. When the scanner reaches the letter H on the reverse scan, the switch is closed again, at point X 2 , thereby indicating that the letter H has been selected.
An apparatus constructed according to the present invention also preferably incorporates means for terminating the reverse scan if a selection is not indicated by a second switch closure within a preselected number of presentations on the reverse scan. If the selection is not made within this preselected number, the forward scanning sequence will start again at the beginning of the list. In this way, a minimum amount of time will be wasted during the slow speed reverse scan if the switch was initially closed by accident or too early in anticipation of the desired selection.
It will become apparent to those skilled in the art that the present invention need not be limited to linear strings of lights. Lights can be arranged in arrays which are scanned row by row, or in other patterns. A large matrix can be scanned by rows to select the row the desired element is on, and then the row is scanned to select the desired element on that row. It is not necessary to use lights at all with the present invention. For example, serial presentation of the alphabet can be made by audio means, such as through an electronic voice synthesizer. The letters can be presented at a rate faster than the reliable response time of the individual, and recited in reverse order, in the manner of FIG. 2, when the first switch closure is made. The same technique may be applied to pictures projected on a screen. The time to scan the entire list is much shorter than with the linear scanning method, which greatly decreases total selection time if the individual does not select the desired symbol the first time around.
It will be apparent that tremendous time savings can be had through use of critically damped scanning. For the selection of each element, only a small number of presentations are made at the slow speed necessary for a response by the individual. The remainder are made at a higher speed, which allows the list to be scanned much more rapidly. The actual time savings are a function of the forward scan speed selected, the reliable response time of the individual, and the number of mistaken switch closures made by the individual. These factors are interrelated to a great extent. For example, the reverse scan speed must be no faster than the reliable response time of the individual. A large portion of the potential time savings is unrealized if a large number of presentations must be scanned at the slower reverse speed. Preferably, the maximum of reverse presentations is given by the formula:
r=R/f (1)
where r is the number of presentations made during the reverse scan, f is the presentation time for each letter during the forward scan, and R is the reliable response time of the individual. Thus, if the forward scanning rate is five times the reliable response time of the individual, the maximum number of presentations made in the reverse scan made prior to resetting the forward scanning procedure should be five. The selection of r in this manner causes the reverse scan of the same number of elements as are forwardly scanned in the time R. If the reliable response time was properly chosen, the individual will complete the first switch closure before the forward scan has gone more than five presentations beyond the desired selection. A greater number of reverse scan presentations will cause a waste of time if a switch closure is accidentally made during the forward scan, and a smaller number will not insure that the desired selection will be reached on the reverse scan prior to resetting.
The selection of the forward scan presentation time (f) depends on several factors. Foremost is the recognition time of the individual. Irregardless of the total reliable response time, from recognition through switch closure, the forward scan presentation time must be long enough that the individual can recognize that his desired selection has been presented. Thus, if the individual takes one second to recognize a presentation, and two more seconds to be certain of switch closure upon recognition of the desired symbol, the forward scan rate can be no faster than one presentation per second. Typically, lamps or LEDs are used to present the symbols, and the recognition time is much faster than this. Thus, the forward presentation rate can be substantially faster.
If the recognition time of the user is a limiting factor, the forward scan speed can be increased by activating two or more lights simultaneously in an overlapping sequence. Thus, the next 1 or 2 elements are activated while the element in question remains activated. This allows each element to be activated for a period exceeding the user's recognition time while the time between successive presentations is shortened below the recognition interval. The use of a capacitor in parallel with the light or LED causes a sufficient delay. Since recognition time is usually not a limiting factor, the embodiment disclosed below will assume the individual presentations are sufficient.
Another factor to consider is the relationshp between the typical number of reverse scan presentations needed and the total number of elements in the list. Since the number of reverse scan presentations made is related to the forward scanning rate by equation (1), a high forward scan rate causes a high number of reverse presentations to be necessary for each selection. Little benefit is gained when the expected number of reverse scan presentations is large in comparison to the total number of elements in the list. It has been determined that setting the maximum number of reverse scan presentations at five for most arrays is fairly efficient. The scanning rates and number of presentations are referenced to the basic time unit of the reliable response time of the individual using the device, and are adjusted to retain proportional relationships when used by individuals having different reliable response times.
For purposes of discussion, a preferred apparatus embodying the present invention includes control circuitry and interfacing adapted to operate in conjunction with a Texas Instrument Speak & Spell, a consumer product which utilizes audio and visual feedback to assist the operator in learning spelling. The standard consumer item utilizes a matrixed keyboard for input. The preferred embodiment discussed below shows the circuitry necessary for an impaired individual to use such a product with the scanning method described above.
FIG. 4 shows a diagram of the modified keyboard of the Speak & Spell suitable for use with the present invention. Each letter and symbol has a corresponding LED, and these are lit sequentially as described above. The scanning sequence begins with the ON position, and scans each row from left to right, returning to the top row after the bottom row has been scanned. If no switch closures are made, the forward scanning will cycle endlessly through the matrix.
FIG. 3 shows a block diagram of the preferred apparatus 12. A switch 14 is operable by an individual, and is coupled to the device 12 through a debounce circuit 16. The debounced switch closure signal is coupled to the clock inputs of four flipflops FF 1 , FF 2 , FF 3 , and FF 4 . FF 1 controls a slow speed oscillator 18, used to drive the reverse scan. FF 2 controls a fast oscillator 20, used to run the forward scan. Both oscillators 18, 20 have adjustable frequency outputs. FF 3 is used to control the direction of the scan, and FF 4 is coupled to a delay circuit 22, the output of which resets the entire circuit. A reverse counter 24 will also reset the circuit when the desired number of presentations have been made on the reverse scan. The outputs of the oscillators 18, 20 are NANDed together to give a single clock signal 26 for the remainder of the circuit. This clock signal 26 drives a printer interface circuit 28, used to connect to an optional printer (not shown), and a matrix decode circuit 30, which sequentially steps through the elements to be presented to the user and decodes them to drive the matrix of FIG. 4, represented by an LED display 32. The matrix decode circuit 30 also drives a keyboard interface circuit 34, which is used to inform a microcomputer contained in the Speak & Spell as to the identity of an element which has been selected.
When the apparatus 12 is initialized at power up, or has been reset after an element selection, the output of the fast oscillator 20 is driving the matrix decode circuit 30 so that the elements are being presented in the forward scan mode. The initial states of the flipflops FF 1 , FF 2 , FF 3 , and FF 4 are such that the fast oscillator 20 is operating, the slow oscillator 18 is not operating, and an UP/DN output is "up", so that the elements are being scanned in the forward mode. The initial operation of the switch 14 causes the flipflops FF 1 , FF 2 , FF 3 , FF 4 to change state, so that the slow oscillator 18 is driving the matrix decoder 30 in the down, or reverse, direction. The down signal enables the counter 24, which is preset to reset the device 12 after the desired maximum number of reverse scan presentations have been made. The device 12 continues to reverse scan until the counter 24 indicates that the maximum number of presentations have been made, or until a second switch closure occurs. At the second switch closure, the slow oscillator 18 ceases operation and the matrix decode circuitry 30 locks in the selected elememt. FF 4 triggers the delay circuit 22, which resets the device 12 after a predetermined delay. The matrix decode circuit 30 enables the keyboard interface 34 after the second switch closure so that the selected element is entered into the operational communications device (not shown), in this case a Speak & Spell.
A detailed schematic diagram of the simplified diagram of FIG. 3 is shown in FIGS. 5 through 7. The preferred embodiment as shown in these figures includes some additional features not discussed in connection with the basic diagram of FIG. 3. The preferred embodiment includes a mode switch, which allows the device to operate in either the standard linear scanning mode as used by the prior art, or in the improved critically damped scanning mode. Another feature is that the reset mode can be selected to operate as described in FIG. 3, or to reset the device only upon a third switch closure made after the desired element is selected. Preferred operation is for both mode switches to be set so that the device operates as described in connection with FIG. 3.
A portion of the schematic diagram of the preferred embodiment is shown in FIG. 5. A reset mode switch 36 has two positions. An AUTO position which provides for automatic reset after a predetermined delay interval after the element selection is made. The MANUAL position provides that the circuit will not be reset until a third switch closure is made. A scan mode switch 38 has positions 1 and 2, with position 1 connecting logical variable M1* to ground, and position 2 connecting the variable M3* to ground. The variable which is not connected to ground is coupled to the power supply, and is therefore a logical High. When the scan mode switch 38 is set to position 1, the device operates in the linear scanning mode. When the mode switch is in position 2, the device operates in the high speed, bi-directional mode.
The input switch 14 is merely a normally open mechanical switch coupled to a debounce circuit 16. When the switch 14 is open, the capacitor 40 is charged and both transistors Q 1 , Q 2 are on, causing the voltage V 1 to be Low (ground). When the input switch 14 is closed, the capacitor 40 is shorted to ground causing the transistors Q 1 , Q 2 to turn off and the junction voltage V 1 to become High, the exact voltage being determined by the ratio of the resistors R 1 , R 2 . Two cross coupled NOR gates 42,44 to form an SR flipflop, and two additional gates 46, 48 form an input buffer. The state of the flipflop will not change unless the INPUT ENABLE signal is Low. Derivation of the INPUT ENABLE signal is discussed in connection with FIG. 6. When the input switch 14 is depressed and released, the junction voltage V 1 goes High, then Low, which causes the NOR gate flipflop, to generate a pulse. This pulse is coupled to the clock (CK) inputs of the control flipflops FF 1 , FF 2 , FF 3 , FF 4 , and acts as their triggering signal.
When the device 12 is set in the two speed scanning mode, the fast flipflop FF 2 is initially set, giving a High output, and the slow flipflop FF 1 is initially reset to give a Low output. This causes the fast oscillator 20 to operate while the slow oscillator 18 does not. Both oscillators 18, 20 are astable logical devices having a controllable delay time on one side of the cycle. Referring to the fast oscillator 20, when the fast flipflop FF 2 output is High, and coupled to one input of a NAND gate 50, the output of the NAND gate 50 is determined by its other input, coupled to voltage V 2 . When the NAND gate 50 output is Low, the transistor Q 3 is off, causing the capacitor voltage V 3 to be High. This causes the next two transistors Q 4 , Q 5 to both be on, so that voltage V 2 is Low. When voltage V 2 is Low, the NAND gate 50 output is driven High, turing on the transistor Q 3 and driving the capacitor voltage V 3 near to the ground. This turns off the two transistors Q 4 and Q 5 , causing voltage V 2 to go High. When V 2 goes High, the NAND gate 50 output again goes Low, turning the transistor Q 3 off and allowing the capacitor voltage V 3 to go High after a delay determined by the capacitor 52 and variable resistor 54 values. When the voltage V 3 becomes somewhat greater than V 2 , the emitter voltage of the transistor Q 4 is higher than the base causing both transistors Q 4 , Q 5 to turn on, driving V 2 Low. This cycle repeats as long as the output from the fast flipflop FF 2 is High. The oscillator 20 frequency is determined primarily by the recharge rate of the capacitor 52, and only incidentally by the delay times imposed by the various transistors Q 3 , Q 4 , Q 5 and NAND gate 50. This frequency can be varied by adjusting the variable resistor 54 to meet the constraints imposed by the reaction time of the user.
The slow flipflop FF 1 was initially reset, so that its output was Low. This causes the output of the slow oscillator NAND gate 56 to always remain High, whereby the slow oscillator 18 does not operate. The D input of the slow flipflop FF 1 is coupled to the output of the fast flipflop FF 2 , so that the slow flipflop FF 1 changes state upon receipt of a clock pulse. This causes the slow oscillator 18 to begin operation.
When the device 12 is in the forward scan mode, a clock pulse is generated by a switch closure as described above. This first clock signal causes the fast oscillator 20 to cease operation and the slow oscillator 18 to begin operation. At the same time, the direction flipflop FF 3 switches from an initial High output setting, corresponding to a forward scan, to a Low output. This causes the device 12 to begin scanning in the reverse direction.
The output of the fast flipflop FF 2 remains Low after the first clock pulse because its D input is grounded. After the second clock pulse, the output of the slow flipflop FF 1 goes Low, so that neither oscillator 18, 20 is operating. When the first flipflop FF 1 output goes Low, SLOW Q* and FAST Q* are both High causing the output of a NAND gate 58 to go Low. Thus, the signal PRESS is High, and PRESS* is Low, after the second clock pulse is received by the flipflops FF 1 , FF 2 , FF 3 , FF 4 . This indicates to the system that the desired element has been selected by the user.
When PRESS* is High, the output of a NOR gate 60 will be Low, causing MEM* to be High. While PRESS* is Low, the output of the NOR gate 60 will depend on the level of Signal B 5 . When B 5 is High, the NOR gate 60 output will be Low, transistor Q 6 will be off, and signal MEM* will be High. If B 5 is Low, the transistor Q 6 will be turned on and the signal MEM* will be Low. MEM* is used in connection with the optional printer interface 28 discussed in connection with FIG. 6.
Prior to the receipt of the first clock pulse, the output of the reset flipflop FF 4 is High, which drives V 4 High after a predetermined delay in the same manner as described with relation to the astable multivibrators utilized in the fast and slow oscillators 18, 20. Upon receipt of the first clock pulse, the reset flipflop FF 4 output is High because the D input, the NOR summation of PRESS(Low) and A.S(Low), is High.
Shortly after the first clock pulse, Slow Q goes High as described above, allowing A.S to go High. This causes the signal at the D input of FF 4 to go Low. Upon receipt of the second clock pulse, the output of the reset flipflop FF 4 goes Low, because a Low signal is present on the D input. After the predetermined delay period, which is set by the values of the capacitor 62 and variable resistor 64, V 4 is driven Low. This causes the circuit to reset by driving FAST S, SLOW R, RESET S, UP/DN S and PE High. When FF 4 goes High, as a result of RESET S going High, V 4 is driven High after a delay. This causes the various reset signals to go Low, so that the circuit begins operation in its initial state.
When the Reset Mode Switch 36 is set to MANUAL position, A.S remains Low. The D input to FF 4 therefore remains High until after the second clock pulse, when PRESS goes High. Therefore, FF 4 will not cause the circuit to reset until the receipt of a third clock pulse.
Capacitor 66 and resistor 68 cause the circuit 12 to reset when it is originally powered up. When power is applied, capacitor 66 charges gradually, causing V 4 to be drawn Low for a period sufficient for the logic elements to power up. As capacitor 66 charges, V 4 can go high, starting proper operation of the device 12.
Counter 70 resets the device 12 when the predetermined number of reverse scan presentations has been made. When the UP/DN signal is High, indicating the device 12 is counting up, the counter 70 is preset to the preselected value upon receipt of each clock signal C x . Derivation of C x will be described in connection with FIG. 6. When UP/DN goes Low, indicating the device 12 is reverse scanning, each C x input causes the counter 70 to count down. C x pulses once for each element presentation made during the reverse scan. The carry output 72 goes Low when the counter 70 counts down to 1. This causes V 4 to go Low, and the device to be reset. As shown, the counter 70 is preset to 6, so that a maximum of 5 elements are presented in the reverse scan. By changing the preset inputs (P 0 , P 1 , P 2 , P 3 ), the counter 70 can be set to limit the reverse scan presentations to any desired value.
A decoder/divider for the LED matrix of FIG. 4 is shown in FIG. 6. The diodes are matrixed in an eight row by five column array, with two rows from the matrix corresponding to one row of the display board shown in FIG. 4. The 8 X 5 matrix scans from the lower left corner to the upper right corner on a row by row basis. Each LED is lit by connecting one matrix row to the positive power supply, and one matrix column to ground, thus driving a single LED. The row to power supply connection is made by driving transistors Q 7 through two inverting 2 line to 4 line decoders 74 as shown in FIG. 6. It would also be possible to substitute a single 3 to 8 line decoder (not shown) for the two shown in FIG. 6. The decoders 74 are driven by row select signals R A , R B , R C derived from a binary up/down counter 76.
The column to be coupled to ground is selected by driving transistors Q 9 from the output of a BCD to 10 line decoder 78, of which only the first five outputs are used. The column selected is determined by three column select inputs C A , C B , C C , which are derived from the B, C, and D outputs of a BCD up/down counter 80. Since only the last three outputs of the BCD counter are used, the column select signal C A , C B , C C will cycle through five places.
Both counters 76, 80 can be preset upon receipt of a signal PE in the preset input, and this signal PE is derived from the reset portion of the control circuitry as described in connection with FIG. 5. The counters 76,80 are preset to begin scanning of the array with the upper right hand element, or the "ON" LED. A C in input inhibits the operation of row counter 76, and enables the counter 76 to operate only upon receipt of a Low signal. The C out output of column counter 80 goes Low only after the last clock pulse of each cycle. Therefore, the output of row counter 76 is incremented once each time the column counter 80 cycles, causing the matrix to be scanned row by row. By changing the preset inputs to the counters 76,80, it is possible to begin scanning after reset at any desired position in the matrix. The clock signal for the counters 76,80 is O A , the derivation of which will be described below. The counters 76, 80 are bidirectional, with the direction controlled by the UP/DN signal derived in FIG. 5. The row select signals R A , R B , C C and column select signals C A , C B , C C used to control the LED matrix will also be used to drive the keyboard interface circuit 34, as described in FIG. 7.
The CK INT signal is coupled to one input of a NOR gate 82, the output of which is coupled to an inverter 84. The inverter 84 output is fed back to the NOR gate 82 input indirectly through NOR gate 86. The inverter 84 output is also coupled to the clock inputs of a binary 88 and a BCD 90 counter. The A and B outputs of the binary counter 88 (signals O A and O B ) are NORed together in gate 92 and coupled to the second input of the NOR gate 86. The output NOR gate 92 is inverted and used as the INPUT ENABLE signal for the debounce circuitry 16 of FIG. 5.
The subcircuit comprising NOR gates 82, 86 and 92, and inverter 84, is stable when CK INT is Low, and both O A and O B are Low. At that point, the output of inverter 84 is Low, as is the output of NOR gate 92. When CK INT goes High, the output of inverter 84 goes High, and clocks counter 88 once, causing O A to go High. The output of NOR gate 92 is now Low, and will remain that way until O A and O B both again go Low. When CK INT goes Low again, the subcircuit becomes astable, and the output of inverter 84 quickly changes state, triggering the clock inputs to the counters 88, 90. The subcircuit becomes stable, and the inverter 84 output stays low, once O A and O B become Low. The subcircuit thus generates 4 very fast clock pulses each time CK INT makes one complete cycle. This causes O A to clock counters 76 and 80 twice, and C X to clock counter 70 (FIG. 5) once, for each cycle of the CK INT signal. Thus, when CK INT cycles once, all parts of the circuit interpret that event as a single change in position of the presented element of the LED matrix. The INPUT ENABLE signal prevents the device 12 from reading an input while the various logical devices are in the process of changing state to the corresponding to the next element to be presented.
Both the binary and BCD counters 88, 90 become preset to all zeros upon receipt of the preset signal PE. Outputs B 0 through B 6 correspond to ASCII characters while the device 12 scans the alphabet. The additional characters in the matrix correspond to non alphabetic ASCII codes. As discussed in connection with FIG. 5, MEM* can only go Low when the desired element has been selected. This signals a printer (which is optional, and not shown) to print the character defined by the outputs B 0 through B 6 . In order to minimize the number of non-standard characters printed, the printer is inhibited after the first 32 matrix elements have been scanned. When B 5 goes High, MEM* is forced High, which inhibits the printer.
The keyboard interface circuit 34 is shown in FIG. 7. This circuit uses the row select and column select signals R A , R B , R C and C A , C B , C C used to drive the LED matrix. The interface 34 is suitable for use in interfacing the present device 12 with a microprocessor or other device normally used to scan a mechanical switch keyboard. (not shown) The interface 34 as shown is adapted for interfacing with the microprocessor that controls the Texas Instruments Speak & Spell product. The interface circuit 34 utilizes the PRESS* signal derived from FIG. 5, and receives inputs from the microprocessor or other scanning device, and has outputs coupled thereto.
A keyboard scanner will typically continuously pulse each row of the keyboard in sequence, and check all columns in parallel for a corresponding pulse. When a column input to the microprocessor records a pulse, the corresponding activated row enables the microcomputer to determine which switch is closed. The present device 12 utilizes no mechanical switches for the keyboard elements, and must use an interfacing circuit to simulate the mechanical switching connection.
The row scan lines, from which a pulse is output from the microprocesser to each keyboard row sequentially, are coupled to the inputs of an 8-1 data selector 94. The line select inputs A, B, C of the data selector 94 are coupled to the row-select signals R A , R B , R C which control the LED matrix. The PRESS* signal is coupled to an INHIBIT input of the encoder 94, whereby the encoder 94 output is Low whenever the PRESS* signal is High. PRESS* goes Low when the second switch closure indicates that the desired element has been selected. When PRESS* is Low, the output tracks any; signals present on the input line selected by R A , R B and R C .
The output from the data selector 94 is inverted and coupled to the D input of an encoder 96. The A, B and C inputs of the encoder 96 are coupled to the column select signals C A , C B and C C respectively. A High signal is present on whichever output line is defined by the signals at the A, B, C and D inputs. As shown in FIG. 7, only the first 5 outputs are used, so if the signals at the 4 inputs A, B, C, D, with D being the most significant digit, define any number greater than 5, all outputs will be Low. Thus, whenever the D input is High, all outputs will be Low.
When the selected row is pulsed High by the scanning device, this pulse will be passed to the output of the data selector 94, causing the D input to the decoder 96 to pulse Low. During this pulse, the output line defined by the columnm select signals C A , C B , C C will go High. At the end of the pulse, the selected column output will again be Low.
PRESS* becomes Low only after the input switch 14 has been depressed twice as discussed in connection with FIG. 5. Therefore, until the switch 14 has been pressed twice, therefore selecting the particular element desired, no pulse signals are input to the microprocessor through the decoder 96 outputs. Once PRESS* goes Low, the row and column of the selected element become fixed as described in connection with FIG. 6, and the keyboard interface 34 operates to indicate the position of the selected item. The inputs to the data selector 94 are pulsed sequentially, but only the pulse corresponding to the selected row is coupled to the output. This pulse is coupled to the column sense input of the microprocessor as determined by the control signals to the decoder 96. Thus, the microprocessor receives a single column sense pulse when the correct row is pulsed by the microprocessor, so that it correctly reads the selected element in a fashion identical to that which would be obtained if mechanical switches on a keyboard were used.
It will become apparent that this keyboard interface 34 can be used to interface an electronic element selection circuit with any keyboard scanning device sensing the closure of a mechanical switch with row scan pulses and column sense inputs. This circuit 34 interfaces a purely electronic selection signal with a keyboard scanner which expects to see an input from a mechanical switch keyboard.
According to the present invention, any simple electric switch which is manipulable by the user may be used as an input switch. A preferred switch 98 for use by certain severely disabled individuals is shown in FIG. 8. This device is especially suitable for persons who have been paralyzed from the neck, or lower face, down. It is a switch which is manipulable by movements of one of the user's eyebrows, and requires only that the user be able to control movements of his eyebrow muscles. It will become apparent that, with only slight modifications, the switch 98 may be used with other regions of the body. Any area where the skin wrinkles, or where 2 parts move relative to each other, may be used. Examples of such areas are the fingers, wrist or elbow.
The switch 98 has an elastic band 100 which is attached around the head of the user, and holds the switch 98 firmly in place on the user's forehead. Two wheel supports 102, 104 hold a small pivotable wheel 106 in place, to which is attached a conducting lever arm 108 that protrudes through the pivotal wheel 106 to make electrical contact with wheel support 102. Wheel support 102 is also conducting. A conducting bracket 110 is attached a rigid, non-conducting support 112, which also supports one end of each of the wheel supports 102,104. The lever arm 108 moves into and out of contact with the bracket 110 when the wheel 106 is rotated about its axis. Connecting wires 114 are coupled to the bracket 110 and the conducting wheel support arm 102.
When the switch 98 is placed in position, the wheel 106 makes contact with the eyebrow of the user. The wheel 106 is preferably made from a soft material, such as rubber, which allows firm contact, with minimum slippage, with the user's eyebrow. When the user's eyebrows are in the relaxed position, the lever arm 108 is pressed back against the nonconducting rigid support 112, and the circuit is open. When the user's eyebrows are raised, the wheel rotates 106 in a clockwise direction as shown in FIG. 8, and the lever arm 108 makes contact with the bracket 110, thereby closing the circuit between the connecting wires 114. When the eyebrows are relaxed, the lever arm 108 breaks contact with the bracket 110, thereby opening the circuit.
An alternate embodiment to the switch 98 is shown in FIG. 9 and includes a small conducting piece 120 coupled to the rigid support 112 between the arms of the conducting bracket 110. In this position, the lever arm 108 will make contact when it is moved fully away from the bracket 110. With the addition of a third connecting wire 121 coupled to the small conducting piece, the alternate switch 98 becomes a double throw, single pole (DPST) switch. The DPST switch can be coupled ot debounce or other logical circuitry to ensure accurate detection of an intended switch opening or closure.
It will also be apparent that the elastic band 100 need not be used if the rigid support 112 is adapted to be coupled to another object, such as eyeglass frames. It is apparent only that the switch 98 be held in the desired position, and the means for so doing is less important, as long as patient comfort is provided for.
The switch 98 is suitable for use with the scanning device 12 of the present invention, which requires merely a simple open and close switch. This switch 98 is especially suitable for use with severely disabled persons, as it is easily placed in the operating position and causes no interference with other activities. It will be apprecicated, however, that other suitable switches may be used.
Although a preferred embodiment has been described in detail, it should be understood that various substitutions, alterations, and modifications may become apparent to those skilled in the art. These changes may be made without departing from the spirit and scope of the invention as defined by the appended claims. | A user operated switch has a support frame mounted to a person's body. A first electrical contact is mounted on and extends from the frame. Contacting structure includes a friction device positioned against a portion of the person's skin and is supported by an electrically conductive support arm. An electrically conducting lever arm has a first end mounted in the friction device in electrical contact with the support arm. A second end of the lever arm is located adjacent the first contact. Skin movement will cause contact between the first contact and the lever arm. The switch may be modified to act as a double throw, single pole switch. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Division of U.S. patent application Ser. No. 10/248,056, filed Dec. 13, 2002, which claims the benefit of U.S. Provisional Application No. 60/415,395, filed Oct. 2, 2002.
BACKGROUND OF THE INVENTION
[0002] (1) Field of the Invention
[0003] This invention relates to protective coating systems for components exposed to high temperatures, such as the hostile thermal environment of a gas turbine engine. More particularly, this invention is directed to a beta-phase nickel aluminide overlay coating whose grain structure is modified to improve oxidation resistance.
[0004] (2) Description of the Related Art
[0005] Higher operating temperatures for gas turbine engines are continuously sought in order to increase their efficiency. However, as operating temperatures increase, the high temperature durability of engine components must correspondingly increase. Significant advances in high temperature capabilities have been achieved through the formulation of nickel and cobalt-base superalloys. Nonetheless, when used to form components of the turbine, combustor and augmentor sections of a gas turbine engine, superalloys can be susceptible to damage by oxidation and hot corrosion attack and may not retain adequate mechanical properties. For this reason, turbine, combustor and augmentor components are often protected by an environmental and/or thermal-insulating coating, the latter of which is termed a thermal barrier coating (TBC) system.
[0006] Environmental coatings that have been widely employed to protect gas turbine engine components include overlay coatings such as MCrAlX (where M is iron, cobalt and/or nickel, and X is yttrium or another rare earth element), and diffusion aluminide coatings, particularly those containing platinum aluminide (Ni(Pt)Al) intermetallic. The aluminum content of these materials provides for the slow growth of a strong adherent and continuous aluminum oxide layer (alumina scale) at elevated temperatures, which protects the coating and its underlying substrate from oxidation and hot corrosion. As apparent from their names, overlay and diffusion coatings are distinguishable in terms of the processes by which they are formed and the thickness of the zone of chemical interaction that occurs within the substrate surface beneath the coating. This zone, referred to as a diffusion zone (DZ), results from the interdiffusion between the coating and substrate. The diffusion zone beneath an overlay coating is typically much thinner than the diffusion zone created within a diffusion bond coat. Diffusion aluminide coatings are also distinguished from overlay coatings, in that the former consists of intermetallic compounds that form as a result of interdiffusion, while the latter can be multi-phase, containing phases such as gamma (γ) and beta (β) nickel aluminide structures if the substrate is a nickel-base superalloy.
[0007] Ceramic materials such as zirconia (ZrO 2 ) partially or fully stabilized by yttria (Y 2 O 3 ), magnesia (MgO) or other oxides, are widely used as thermal barrier coatings (TBC's), or topcoats, on gas turbine engine components. To be effective, TBC's must strongly adhere to the component surface and remain adherent throughout many heating and cooling cycles. The latter requirement is particularly demanding due to the different coefficients of thermal expansion between TBC materials and the superalloys typically used to form turbine engine components. TBC systems capable of satisfying the above requirements have generally required a bond coat, typically formed of one or both of the above-noted diffusion aluminide and MCrAlX coatings. In addition to protecting the bond coat and underlying substrate from oxidation and hot corrosion, the alumina scale that grows on diffusion aluminide and MCrAlX coatings serves to chemically bond a ceramic layer to the bond coat. A thermal expansion mismatch exists between metallic bond coat materials, the alumina scale and ceramic layer, which results in stresses at their interfaces. Over time, microcracking and damage increase, eventually leading to spallation of the TBC.
[0008] In view of the above, it can be appreciated that bond coats have a considerable effect on the spallation resistance of the TBC, and therefore TBC system life. Consequently, improvements in TBC life have been sought through modifications to the chemistries of existing bond coat materials. Other types of bond coat materials have also been proposed, such as beta-phase nickel aluminide (NiAl) overlay coatings that have also found use as environmental coatings. The NiAl beta phase is an intermetallic compound that exists for nickel-aluminum compositions containing about 30 to about 60 atomic percent aluminum. Notable examples of NiAl coating materials are disclosed in commonly-assigned U.S. Pat. Nos. 5,975,852 to Nagaraj et al., 6,291,084 to Darolia et al., 6,153,313 to Rigney et al, and 6,255,001 to Darolia. These NiAl alloys, which preferably contain a reactive element (such as zirconium) and/or other alloying constituents (such as chromium), have been shown to improve the adhesion of a ceramic TBC layer, thereby increasing the service life of the TBC system.
[0009] In addition to modifications to their chemistry, the effect of the surface finish of diffusion aluminide and MCrAlY bond coats on TBC spallation resistance has also been investigated, as evidenced by U.S. Pat. No. 4,414,249 to Ulion et al. with respect to MCrAlY overlay coatings, and commonly-assigned U.S. Pat. No. 6,340,500 to Spitsberg and co-pending U.S. patent application Ser. No. 09/524,227 to Spitsberg with respect to diffusion aluminide coatings. Ulion et al. disclose that TBC service life can be improved by polishing the surface of a peened and heat-treated MCrAlY overlay bond coat. The benefit of peening is said to be increased density of the bond coat. The Spitsberg patent and patent application teach that the benefit of improving the surface finish of a diffusion aluminide bond coat is that the resulting modified surface morphology of the bond coat eliminates or at least reduces oxidation and oxidation-induced convolutions at the alumina-bond coat interface. The Spitsberg patent further teaches that peening and then heat treating a diffusion aluminide bond coat can significantly improve TBC service life, particularly if the bond coat does not undergo recrystallization during heat treatment. In contrast, the pending Spitsberg application teaches that TBC service life is improved by recrystallizing a diffusion aluminide bond coat to eliminate the original grain boundaries, which is believed to have the effect of creating more stable grains and reducing the quantity of refractory phases at the grain boundaries.
[0010] The mechanism by which TBC spallation initiates can depend on the type of bond coat used. Spallation of TBC deposited on one of the aforementioned beta-phase NiAl overlay bond coats has been observed to occur by delamination of the alumina scale from the bond coat or TBC delamination from the alumina scale. However, the mechanism by which spallation initiates from an NiAl overlay bond coat differs from MCrAlX and diffusion aluminide bond coats as a result of differences in chemistry, microstructure and mechanical properties. For example, NiAl overlay bond coats are believed to exhibit a different spallation mechanism than diffusion aluminide bond coats as a result of having higher creep resistance and flow or yield strengths at elevated temperatures.
[0011] Though having the above-noted advantages, TBC service life on NiAl overlay bond coats containing zirconium and/or chromium has been found to be sensitive to Zr and Cr content. Therefore, improvements in TBC service life deposited on NiAl overlay bond coats would be desirable. However, possible modifications in chemistry, microstructure and mechanical properties that might achieve an improvement must take into account the unique characteristics of NiAl overlay coatings, including the mechanism by which TBC spallation is initiated on an NiAl overlay bond coat.
BRIEF SUMMARY OF THE INVENTION
[0012] The present invention generally provides a beta-phase nickel aluminide (NiAl) overlay coating suitable for use as a bond coat for a thermal barrier coating (TBC) system, and further provides a method for modifying the grain structure of such a bond coat in order to improve the spallation resistance of the TBC system. NiAl overlay coatings of this invention are deposited by methods that conventionally produce a generally columnar grain structure in which grains, and therefore grain boundaries, extend through the bond coat, from the outer surface of the bond coat to the surface of the substrate on which the bond coat is deposited, such that grain boundaries are exposed at the bond coat surface. Methods by which bond coats of this invention are deposited are generally physical vapor deposition (PVD) techniques, including electron beam physical vapor deposition (EBPVD), sputtering and directed vapor deposition (DVD).
[0013] According to a preferred aspect of the invention, the spallation resistance of a TBC deposited on an NiAl overlay coating of a type described above can be improved by modifying the microstructure of the overlay coating, which if properly performed has been shown to improve the oxidation resistance of the overlay coating. The NiAl overlay coating is first deposited on a substrate surface to have grains with grain boundaries that are continuous through the overlay coating from an outer surface of the overlay coating to the surface of the substrate. As a result, the as-deposited grain boundaries of the overlay coating are exposed at the outer surface of the overlay coating. The as-deposited grain boundaries may contain precipitates as a result of the alloyed chemistry of the coating. A particular example is the addition of limited amounts of zirconium and optionally chromium in accordance with commonly-assigned U.S. Pat. Nos. 6,153,313 to Rigney et al, and 6,291,084 to Darolia et al. During or after deposition, the overlay coating is caused to form new grain boundaries that are open to the outer surface of the overlay coating, though many are not continuous through the coating. If precipitates were originally present in the overlay coating, the new grain boundaries contain fewer precipitates than the as-deposited grain boundaries. New grain boundaries can be obtained by causing the overlay coating to recrystallize as a result of the coating sustaining a sufficiently high temperature, either during deposition or in a post-deposition process during which some of the precipitates (if present) are preferably solutioned. For example, the coating may be deposited on a substrate maintained at a sufficiently high temperature so that recrystallization occurs during deposition. Another approach is to cold or warm work and then heat treat the coating at a temperature sufficient to cause recrystallization.
[0014] According to this invention, grain boundaries of an as-deposited NiAl overlay coating that are exposed at the coating surface are prone to accelerated oxidation, particularly if zirconium-containing precipitates are present within the grain boundaries. NiAl overlay coatings processed according to this invention are characterized by grains whose grain boundaries are open to the outer surface of the coating, but are less susceptible to oxidation as a result of the grain boundaries being relocated, such that any precipitates originally present in the as-deposited grain boundaries are within the grains and substantially reduced from the new grain boundaries. As a result, the oxidation resistance of the NiAl overlay coating is improved, corresponding to improved spallation resistance for a TBC deposited on the coating.
[0015] Other objects and advantages of this invention will be better appreciated from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a perspective view of a high pressure turbine blade.
[0017] FIG. 2 is a cross-sectional representation of a TBC system on a surface region of the blade of FIG. 1 along line 2 - 2 .
[0018] FIG. 3 is a cross-sectional representation of an NiAl overlay bond coat of the TBC system shown in FIG. 2 , but in the as-deposited condition.
[0019] FIGS. 4 and 5 are scanned images of an NiAl(Zr) overlay bond coat of a TBC system, shown in FIG. 4 in the as-deposited condition and shown in FIG. 5 following thermal cycling in an oxidizing atmosphere.
DETAILED DESCRIPTION OF THE INVENTION
[0020] The present invention is generally applicable to components that operate within environments characterized by relatively high temperatures, and are therefore subjected to severe thermal stresses and thermal cycling. Notable examples of such components include the high and low pressure turbine nozzles and blades, shrouds, combustor liners and augmentor hardware of gas turbine engines. An example of a high pressure turbine blade 10 is shown in FIG. 1 . The blade 10 generally includes an airfoil 12 against which hot combustion gases are directed during operation of the gas turbine engine, and whose surface is therefore subjected to severe attack by oxidation, corrosion and erosion. The airfoil 12 is anchored to a turbine disk (not shown) with a dovetail 14 formed on a root section 16 of the blade 10 . Cooling holes 18 are present in the airfoil 12 through which bleed air is forced to transfer heat from the blade 10 . While the advantages of this invention will be described with reference to the high pressure turbine blade 10 shown in FIG. 1 , the teachings of this invention are generally applicable to any component on which a TBC system may be used to protect the component from its environment.
[0021] Represented in FIG. 2 is a thermal barrier coating (TBC) system 20 that includes an overlay bond coat 24 and a thermal-insulating ceramic layer, or TBC, on a superalloy substrate 22 that is typically the base material of the blade 10 in FIG. 1 . Suitable materials for the substrate 22 (and therefore the blade 10 ) include equiaxed, directionally-solidified and single-crystal nickel and cobalt-base superalloys. The bond coat 24 adheres the ceramic layer 26 to the substrate 22 through the growth of an alumina scale 28 when the bond coat 24 is exposed to an oxidizing atmosphere, such as during high temperature exposures in air and deposition of the ceramic layer 26 . As shown, the ceramic layer 26 has a strain-tolerant grain structure of columnar grains 30 achieved by depositing the ceramic layer 26 using physical vapor deposition techniques known in the art, such as EBPVD. A preferred material for the ceramic layer 26 is an yttria-stabilized zirconia (YSZ), a preferred composition being about 4 to about 8 weight percent yttria, though other ceramic materials could be used, such as yttria, nonstabilized zirconia, or zirconia stabilized by magnesia, ceria, scandia or other oxides. The ceramic layer 26 is deposited to a thickness that is sufficient to provide the required thermal protection for the underlying substrate 22 and blade 10 , generally on the order of about 75 to about 300 micrometers.
[0022] As an overlay coating, little interdiffusion occurs between the bond coat 24 and the substrate 22 during deposition as well as any subsequent heat treatments (if employed). According to a preferred aspect of the invention, the bond coat 24 is formulated in accordance with commonly-assigned U.S. Pat. Nos. 6,153,313 to Rigney et al, and 6,291,084 to Darolia et al., and therefore contains beta-phase NiAl intermetallic, zirconium and optionally chromium or another element disclosed in Rigney et al. or Darolia et al. For example, the bond coat 24 may contain, in atomic percent, about 30% to about 60% aluminum, about 0.1% to about 1.2% zirconium, optionally up to about 15% chromium, the balance essentially nickel. A thickness of about 50 micrometers is suitable for the bond coat 24 to protect the underlying substrate 22 and provide an adequate supply of aluminum for oxide formation, though thicknesses of about 10 to about 125 micrometers are believed to be acceptable.
[0023] The bond coat 24 is represented in FIG. 2 as having been deposited and processed in accordance with this invention so that any precipitates 40 within the bond coat 24 are located primarily within the grains 32 of the bond coat 24 , but largely absent from the grain boundaries 34 that intersect the surface 36 of the bond coat 24 . In contrast, FIG. 3 represents the overlay bond coat 24 as it would appear if deposited and processed in accordance with conventional practice, e.g, in an as-deposited condition without any additional treatment provided by the present invention. The type of microstructure represented in FIG. 3 is typical of NiAl overlay coatings deposited by PVD, such as EBPVD. In FIG. 3 , the bond coat 24 is characterized by grains 42 that extend through the bond coat 24 , from the surface 36 of the bond coat 24 to the surface 38 of the substrate 22 , such that the grains 42 are generally columnar with a larger aspect ratio than the grains 32 depicted in FIG. 2 . As also represented, the grains 42 have grain boundaries 44 that intersect the surface 36 of the bond coat 24 . The grain boundaries 44 that are open to the bond coat surface 36 are shown as being decorated with precipitates 40 formed during deposition of the bond coat 24 as would result from the presence of zirconium or another alloying constituent within the NiAl material.
[0024] As discussed below, the microstructure depicted in FIG. 2 is more resistant to oxidation than the microstructure depicted in FIG. 3 , with the result that a TBC (the ceramic layer 26 in FIG. 2 ) deposited on the bond coat 24 of FIG. 2 is more resistant to spallation.
[0025] During an investigation leading to this invention, a study of TBC spallation mechanisms on NiAl bond overlay coats alloyed with zirconium (“NiAl(Zr)”) indicated that spallation typically initiated by either delamination of the oxide scale (e.g., scale 28 in FIG. 2 ) from the bond coat or by delamination of the TBC (e.g., ceramic layer 26 in FIG. 2 ) from the oxide scale. Notably, rumpling of the oxide scale, as occurs in diffusion aluminide bond coats, was not observed. This difference was theorized as being the result of improved creep resistance or yield strength of the NiAl(Zr) material, and/or the differences in the coating grain structure resulting from the different processing methods used to form overlay and diffusion coatings. While various properties of coating, including microhardness, strength and plasticity, are known to be effected by microstructure, it is believed that the influence that microstructure might have on oxidation, which leads to TBC spallation, has not.
[0026] The effect of grain structure was investigated, initially by altering the temperature at which NiAl(Zr) overlay bond coats were deposited by EBPVD. In the investigation, forty-one superalloy specimens were coated with a TBC system of the type shown in FIG. 2 . The superalloys was René N5 with a nominal composition in weight percent of Ni-7.5Co-7.0Cr-6.5Ta-6.2Al-5.0W-3.0Re-1.5Mo-0.15Hf-0.05C-0.004B-0.01Y. The bond coats were NiAl overlay coatings containing, by weight, about 22% aluminum, about 4 to about 7% chromium, and about 1% zirconium, the balance nickel and incidental impurities. The bond coats were deposited by EBPVD at deposition (substrate) temperatures of either about 500° C. or about 1000° C. and above. The ceramic topcoats were zirconia stabilized by about 7 weight percent yttria (7% YSZ), and all were deposited by EBPVD. The specimens were furnace cycle tested (FCT) at 2125° F. (about 1160° C.) at one-hour cycles within an oxidizing atmosphere, until TBC spallation occurred.
[0027] Significant scatter in cycles to spallation was observed for the specimens, ranging from less than fifty cycles to about 1100 cycles. The spalled specimens were examined using scanning electron microscopy (SEM) to determine their coating microstructures. A number of microstructural features were quantified, including grain morphology. It was observed that columnar grains (similar to that represented in FIG. 3 ) were typically present in coatings deposited at substrate temperatures of about 500° C., while equiaxed microstructures (similar to that represented in FIG. 2 ) were present in specimens whose deposition temperatures were about 1000° C. and above. The equiaxed specimens had a smaller average aspect ratio and exhibited little texture, indicating that the NiAl(Zr) overlay coatings had undergone recrystallization during deposition. Specimens with equiaxed grain structures were consistently found to exhibit significantly better resistance to spallation (above 600 cycles to spallation) than specimens with columnar grain structures.
[0028] In addition to grain morphology, a low state of residual stress in the grains was also associated with improved resistance to spallation. Average intragrain misorientation (AMIS) levels were measured by orientation imaging microscopy (OIM) using a scanning electron microscope (SEM) and evaluating backscattered electron patterns over a number of test points covering several grains. Low residual stress, or strain, levels, corresponding to measured AMIS of less than about 0.7 degrees, were typically found for the fully recrystallized overlay coatings that were associated with significantly improved spallation resistance.
[0029] In view of the above results, an additional number of specimens were prepared essentially identically to the original specimens, but with all of the NiAl(Zr) overlay bond coats being deposited at a temperature in the range of about 900° C. to about 1000° C., yielding recrystallized equiaxed grain structures. The specimens were evaluated using the same FCT conditions as before, with the result that the additional specimens were again consistently found to exhibit significantly better resistance to spallation than the original specimens as a whole, averaging about 560 cycles to spallation as compared to an average of about 81 cycles for specimens in the previous investigation. Examination of the specimens evidenced that they exhibited significantly better oxidation resistance than coatings deposited at lower temperatures.
[0030] From the above results, it was theorized that deposition (substrate) temperatures on the order of about 900° C. and higher, particularly 1000° C. and higher, cause bulk recrystallization during coating deposition, yielding an equiaxed NiAl overlay coating that is more resistant to oxidation than an as-deposited NiAl overlay coating having columnar grains.
[0031] Further examination of specimens having columnar and equiaxed microstructures showed that a large number of zirconium-rich precipitates decorated the grain boundaries of the columnar NiAl(Zr) coatings (deposited below about 870° C.), as represented in FIG. 3 . FIG. 4 is a pre-FCT scanned image of a specimen having a columnar microstructure, with Zr-rich particles being clearly evident in the grain boundaries (referred to as leaders) open to the coating surface. In contrast, zirconium-rich precipitates within the equiaxed NiAl(Zr) coatings (e.g., deposited at about 1000° C. and higher) were located primarily within the grains and not the grain boundaries, particularly the leader boundaries open to the coating surface, as represented in FIG. 2 .
[0032] For the columnar coatings, it appeared the Zr-rich precipitates in the leader boundaries were very detrimental to the oxidation resistance of the coatings, presumably because of accelerated oxidation at the leader boundaries. Increased oxide growth rates corresponded to depletion of aluminum and zirconium in the surrounding matrix, resulting in the formation of spinel-type oxides and other oxides that are not adherent to the bond coat. A specimen processed in accordance with the above to have an NiAl overlay with a columnar microstructure (as a result of being deposited at a temperature of about 870° C.), was exposed to an oxidizing atmosphere for about one hundred-twenty hours at a temperature of about 2150° F. (about 1180° C.). Upon examination, it was determined that oxidation had occurred via the leader boundaries, allowing for accelerated oxidation through the coating thickness FIG. 5 is a scanned image of a specimen processed in accordance with the above to have an NiAl overlay with a columnar microstructure as a result of being deposited at a temperature of about 870° C., and after exposure to an oxidizing atmosphere for about one hundred-twenty hours at a temperature of about 2150° F. (about 1180° C.). From FIG. 5 , it can be seen that oxidation occurred via the leader boundaries, allowing for accelerated oxidation through the coating thickness.
[0033] From the above, it was concluded that the oxidation resistance of an NiAl overlay bond coat, and therefore the spallation resistance of a TBC deposited on the bond coat, could be achieved by eliminating grain boundaries (leaders) that are open to the coating surface and by eliminating decorated with Zr-rich precipitates. The investigations into the effects of deposition temperature indicated that this object could be at least partially accomplished through the use of deposition temperatures above 1000° C., possibly as low as about 900° C., but preferably above 1050° C., at which recrystallization of NiAl coatings occurs during deposition by PVD processes.
[0034] The upper limit for deposition temperatures required to produce the desired equiaxed microstructure is generally limited by superalloy gamma-prime solutioning and melting temperatures, necessitating tight control of the process temperature. It was theorized that similar improvements in oxidation resistance of NiAl overlay coatings might also be achieved with coatings deposited at lower substrate temperatures, but then caused to recrystallize by suitable post-deposition processing. For example, recrystallization can be induced by a surface mechanical treatment that introduces cold working into the bond coat, so that at least the surface if not the entire overlay coating undergoes recrystallization when sufficiently heated to drive the recrystallization process. For this purpose, sufficiently intense peening is believed to be necessary, followed by a heat treatment at a temperature of about 1000° C., such as about 980° C. to about 1020° C. for a duration of about 0.5 to about 4 hours in an inert or otherwise low-oxygen atmosphere. Recrystallization is expected to be dependent on peening intensity (cold working), such that a sufficient peening intensity would be critical to achieving improved oxidation resistance by way of recrystallization. For this reason, shot peening with full surface coverage and an intensity of at least 6 A is believed to be necessary to produce an NiAl overlay coating having equiaxed grains. Notably, previous uses of peening to densify overlay coatings and close leader boundaries would not result in the recrystallization effect sought by the present invention. While shot peening is a particularly suitable cold and warm working technique because it can be readily controlled and characterized in terms of stresses distribution, it is foreseeable that other cold working techniques could be used.
[0035] An additional benefit to producing equiaxed microstructures through post-deposition processing is the potential to reduce the quantity of Zr-rich precipitates within the coating. Specifically, it is believed that a post-deposition heat treatment at temperatures of about 980° C. or more in a low-oxygen atmosphere (less than 110 torr) should result in the dissolution of at least some of the Zr-rich precipitates, thereby further reducing the likelihood that such precipitates will be present at the leader boundaries. It is further believed that the remaining precipitates 40 will be reduced in size during the heat treating step.
[0036] While the invention has been described in terms of a preferred embodiment, it is apparent that other forms could be adopted by one skilled in the art. Therefore, the scope of the invention is to be limited only by the following claims. | A beta-phase nickel aluminide (NiAl) overlay coating ( 24 ) and method for modifying the grain structure of the coating ( 24 ) to improve its oxidation resistance. The coating ( 24 ) is deposited by a method that produces a grain structure characterized by grain boundaries ( 44 ) exposed at the outer coating surface ( 36 ). The grain boundaries ( 44 ) may also contain precipitates ( 40 ) as a result of the alloyed chemistry of the coating ( 24 ). During or after deposition, the overlay coating ( 24 ) is caused to form new grain boundaries ( 34 ) that, though open to the outer surface ( 36 ) of the coating ( 24 ), are free of precipitates or contain fewer precipitates ( 40 ) than the as-deposited grain boundaries ( 44 ). New grain boundaries ( 34 ) are preferably produced by causing the overlay coating ( 24 ) to recrystallize during coating deposition or after deposition as a result of a surface treatment followed by heat treatment. | 2 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention The invention lies in the field of mounting electronic components or modules, in particular electrooptical modules (known as transceivers). When mounting modules of this type on carriers, for example printed-circuit boards provided with conductor tracks and connection contacts, there is the requirement on the part of the user for modules which can be placed on the printed-circuit board relatively freely and unrestrictedly. This requires modular configurations and suitable mechanical connections which—depending on the available mounting space and accessibility—allow simple horizontal insertion of the modules into suitable holders or permit vertical mounting of the modules.
[0002] U.S. Pat. No. 5,154,631 discloses a mounting device which has mounting rails, with a planar substrate as the carrier of an electric circuit having projections along two opposite edges. The projections may be formed vertically in the mounting rails, the substrate subsequently sliding along angled slots into an end position. Since, however, in the end position, the substrate is not secured against being pulled off in a vertical or angled direction, the mounting device is not suitable for the mounting of the electrooptical modules.
[0003] U.S. Pat. No. 5,734,558 discloses module variants each with a connection-contact strip which either protrudes at right angles from the underside of the module or penetrates the narrow rear wall of the rear region of the module, seen in the pushing-in direction. The first module variant consequently allows only mounting that is exclusively perpendicular to a holder, during which the resilient electrical contacts of the contact strip on the module side penetrate vertically into corresponding co-operating contacts of a contact receptacle on the holder side. This variant requires for mounting and removal a corresponding free space in the vertical direction (referred to hereafter as the Y direction) above the holder. The other variant allows only mounting in a horizontal direction parallel to the upper side of the holder (hereafter referred to as the Z direction), that requires a corresponding free space in front of the holder. Moreover, precise guiding of the module during the connection to the holder is not provided in either variant of the module.
SUMMARY OF THE INVENTION
[0004] it is accordingly an object of the invention to provide a connection system that overcomes the above-mentioned disadvantages of the prior art devices of this general type, which allows both mounting exclusively in the Z direction and mounting with a movement in the Y direction and subsequent movement in the Z direction, with an extremely small free space being required.
[0005] With the foregoing and other objects in view there is provided, in accordance with the invention, a connection system containing a holder having longitudinal sides, an upper side, and holding rails disposed on the longitudinal sides. An electronic component is releasably mechanically connected to the holder and covers at least an amount of residual travel before arriving in an end position. The electronic component has longitudinal sides with two holding regions disposed on each of the longitudinal sides that interact at least partially with the holding rails during the residual travel. The holding rails having gaps formed therein for allowing a vertical insertion of the holding regions perpendicularly in relation to the upper side of the holder. The residual travel into the end position takes place exclusively along a pushing-in direction running parallel to the upper side of the holder.
[0006] The holding regions are rear-engagement devices which, as seen in the pushing-in direction, are disposed one behind another and, during the residual travel, grip at least partially under the holding rails. The gaps are formed such that the rear engagement devices that are leading in the pushing-in direction pass the gaps during a mounting operation without being able to come away from the holder transversely in relation to the pushing-in direction.
[0007] One significant advantage of the connection system according to the invention is that, depending on the circumstances specific to the particular application, in particular according to the space available in each case for mounting and removal, and the desired configuration of the holder on a carrier, it allows if need be both mounting or removal exclusively in the Z direction and mounting essentially vertically, with a movement in the Y direction with a subsequent (small residual) movement in the Z direction, covering the residual amount of travel. One significant aspect of this is that both mounting variants are inherent to the connection system, so that it is quite possible for different sequences of movements also to be realized during mounting and removal. One significant advantage of the invention for user friendliness and reliability is that, when mounting in the Z direction, it is ensured by the envisaged configuration of the gaps with respect to the leading rear-engagement devices that, even when they are moving past the gaps, the rear-engagement devices cannot leave the holding rails transversely in relation to the pushing-in direction at least not without considerable force being exerted. The connection system according to the invention consequently ensures a guided and reliable mounting movement in the Z direction (pushing-in direction) in spite of the alternative mounting and removal possibilities.
[0008] In principle, the reliable guidance of the leading rear-engagement devices during mounting in the Z direction (exclusively) could be ensured by the width of the rear-engagement devices being greater than the gaps and, for example, by the rear-engagement devices being able to be temporarily reduced in their width elastically for the mounting in the vertical direction. However, a configuration that is preferred from a technical mounting viewpoint provides that the width of the gaps corresponds at least to the width of the rear-engagement devices that are leading in the pushing-in direction.
[0009] To allow the leading rear-engagement devices to pass the gaps reliably during the mounting operation in the Z direction (exclusively), according to a preferred configuration of the invention it is provided that the gaps of holding rails lying opposite one another are at a greater spacing than the clear spacing of the assigned leading rear-engagement devices lying opposite one another.
[0010] In particular in cases where there are a relatively large number of interactions during mounting, it is advantageous if the gaps have lead-in slopes and/or removal slopes, along which the rear-engagement devices slide during mounting or removal of the component vertically in relation to the holder. It is particularly preferred that the rear-engagement devices can in this case be of a resilient configuration.
[0011] Other features which are considered as characteristic for the invention are set forth in the appended claims. Although the invention is illustrated and described herein as embodied in a connection system, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0012] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] [0013]FIG. 1 is a diagrammatic, perspective view of a holder according to the invention;
[0014] FIGS. 2 to 4 are perspective views of a mounting sequence of a connection system between a component and the holder according to FIG. 1;
[0015] FIGS. 5 to 7 are perspective views of the mounting sequence from an underside of the component;
[0016] [0016]FIGS. 8 a and 8 b are partial, perspective views of the situation during mounting in Y-Z directions; and
[0017] [0017]FIG. 9 is a partial, perspective view of a detail of the connection system for explaining the situation during mounting only in the Z direction.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] In all the figures of the drawing, sub-features and integral parts that correspond to one another bear the same reference symbol in each case. Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown a holder 1 . The holder 1 is formed of essentially three components, and as seen in a direction of a longitudinal axis of the holder 1 , contains a locking tongue 2 , a holding block 3 and a connection part 4 . The longitudinal axis of the holder 1 coincides with a pushing-in direction Z, defined according to FIG. 1 as the Z direction and running horizontally and parallel to an upper side l a of the holder 1 . The holding block 3 has at its front end lead in slopes or bevels 3 c, 3 d on longitudinal sides 3 a, 3 b for guiding a component housing, still to be described in more detail, or a rear-engagement device on the component side. The bevels 3 c, 3 d are adjoined by portions 3 e, 3 f of parallel holding rails 6 , 7 running on both sides that are formed on the longitudinal sides 3 a, 3 b. The holding rails 6 , 7 are interrupted in a rear region of the holding block 3 by clearances or gaps 8 , 9 . The gaps 8 , 9 reach as far as the connection part 4 , and on the narrow sides of the connection part portions 4 a, 4 b continue forming the rails 6 , 7 .
[0019] A mounting sequence of a component 10 on the holder 1 of the type shown in FIG. 1 is now explained with reference to FIGS. 2 to 4 . The holder 1 is in this case mounted on an upper side 11 of a printed-circuit board 12 , represented in an indicated way, and its contacts are made with non-illustrated electrical supply leads. In the case of the mounting variant explained below, the mounting includes a vertical downward movement perpendicularly in relation to the upper side la of the holder 1 (Y direction) and a subsequent, comparatively small pushing in movement in the Z direction or pushing-in direction Z.
[0020] The component 10 has a component housing 16 , which has on each of its longitudinal sides, seen in the pushing-in direction Z. two rear-engagement devices 18 , 19 , disposed one behind the other. In the view according to FIG. 2, only the rear engagement devices 18 , 19 , which are formed on a side 16 a of the component housing facing the viewer, are visible. Lying opposite on the other longitudinal side 16 b of the housing 16 , corresponding, similar rear-engagement devices, facing the rear-engagement devices 18 , 19 , are formed. Revealed in FIG. 2 are resilient connection contacts 4 c (see also FIG. 1) of the connection part 4 , which, in a final mounted state, are in contact with corresponding connection contact surfaces on the underside of a printed-circuit board disposed in the housing 16 . The contacts 4 c consequently exert a vertical spring force in the Y direction, which is absorbed in the interaction still to be explained in more detail between the rear engagement devices 18 , 19 and the holding rails 6 , 7 of the holder 1 .
[0021] [0021]FIG. 3 shows the component 10 and the holder 1 in an advanced stage of mounting, in which the mounting movement in the Y direction has already been completed, but the remaining mounting in the Z direction still has to take place. With the remaining residual mounting movement, a residual amount of travel W is covered into an end position (FIG. 4). The rear-engagement devices 18 , 19 have in this case already been lowered to the level of a lower side of the rails 6 , 7 facing the upper side 11 of the carrier. The rear engagement device 19 has in this case penetrated the gap 9 . During the subsequent (residual) mounting movement in the Z direction, the component 10 is displaced to the rear until its reaches an end position P shown in FIG. 4. In this case, a rear actuating cam 20 , which can be seen in FIG. 3, is moved by a slideway guide (not represented in any more detail) in such a way that the contacts 4 c (FIG. 2) are initially removed from the plane of movement of the printed-circuit board on the component side and, when the end position P is reached (FIG. 4), spring back onto the assigned connection contact surfaces. The opposing force in relation to the spring forces exerted as this happens is applied, as already mentioned at the beginning, by the engagement of the rear-engagement device behind the assigned rails.
[0022] For further explanation of the mounting operation described above, details of the connection system are represented in FIGS. 5, 6 and 7 in a perspective view from the underside of the configuration (with the printed circuit board 12 from FIG. 2 omitted). The underside of the holder 1 has, in the region of the holding block 3 and the connection part 4 , centering pins 22 for positioning the holder on the surface 11 (FIG. 2) of the printed circuit board 12 . Furthermore, the portions 3 e, 3 f and 4 a, 4 b of the rails 6 , 7 can be seen. Also represented are connection contact surfaces 24 of a printed-circuit board 25 contained in the housing 16 , which in the final mounted state co-operate with the contacts 4 c. The representation in FIG. 5 shows the gap 8 which is provided in the holding rails 6 and, in the course of further mounting, is penetrated by a rear-engagement device 28 lying opposite the rear-engagement device 19 (shown in FIG. 2).
[0023] [0023]FIG. 6 shows the component 10 after completion of the mounting movement in the Y direction and before the component 10 is moved into its end position by the amount of residual travel W in the Z direction. In this state, the rear-engagement devices 19 , 28 that are at the rear, seen in the pushing-in direction Z (referred to hereafter with respect to the pushing-in direction Z also as leading rear-engagement devices) have already penetrated the gap 8 , 9 respectively assigned to them and are bearing against the undersides 6 a, 7 a of the holding rails 6 , 7 . A width b of the gaps 8 , 9 is dimensioned such that it is wider than the width B of the rear-engagement devices 19 , 28 .
[0024] [0024]FIG. 7 shows the component 10 and the holder 1 shortly before reaching the end mounting position, in which a corresponding locking lug 30 penetrates a front clearance in the locking tongue 2 , in order to lock the component 10 with respect to the holder 1 in the Z direction. The rear-engagement devices 19 , 28 that are leading in the Z direction are in this case already resting over a considerable portion of a width B on the undersides 6 a, 7 a of the rails 6 , 7 and consequently engage behind the rails 6 , 7 . The rear-engagement devices 18 , 31 formed further forward on the longitudinal side 16 a, 16 b, seen in the pushing-in direction Z, have run onto the undersides of the portions 3 e, 3 f of the holder 1 in a corresponding way.
[0025] The situation when the component 10 is placed onto the holder 1 is schematically represented in detail with regard to the rear-engagement devices in FIGS. 8 a and 8 b. When the component 10 or its housing 16 is lowered in the Y direction, a run-on slope 19 a of one of the rear-engagement devices represented by way of example (e.g. 19 ) comes into physical contact with a lead-in slope 9 a of the gap 9 (see also FIG. 1). As a result, the rear-engagement devices 19 , 28 lying opposite one another (FIG. 6) are extended in their spacing c to a spacing d, which exists between the vertical surfaces of the lug-like projections lying opposite one another (only the projection 9 b is shown here) of the gaps 8 , 9 . In this case, the rear-engagement devices 19 , 28 facing one another spring open elastically and snap in behind the lug-like projection 9 b in the region of the gap 9 . In this case, a further slope 19 b then bears against an assigned slope 9 c of the projection 9 b. In this way, the component can also be removed again vertically from this position—although only with a certain vertical exertion of force in the Y direction.
[0026] An alternative type of mounting is explained below with renewed reference to FIGS. 1 and 6 and also 9 . It is alternative because the component can also be mounted and removed exclusively in the Z direction. During the pure Z movement, the leading rear-engagement device 19 , 28 are already guided in the frontal region of the holding block 3 , by the bevels 3 c, 3 d, into the desired plane of movement below the portions 3 a, 3 b of the holding rails 6 , 7 . The leading rear-engagement device 19 , 28 in this case pass the gaps 8 , 9 without being able to leave the holder again from these gaps in the vertical direction (at least under the effect of normal mounting forces). As FIG. 9 indicates in this respect, this is because the rear-engagement devices (only one rear engagement device 19 is shown by way of example) continue, with the slope 19 b, to be in physical contact with the slope 9 c in the region of the gap 9 . This ensures that, even in the case of mounting exclusively in the Z direction, the component is always guided reliably and highly precisely onto the holder until it is in the end position. A corresponding situation exists if the component is removed exclusively in the Z direction. | A connecting system for detachably mechanically connecting an electronic component to a support is described. The connecting system has fixed rails that are configured on the longitudinal sides of the support. When the connecting system is assembled, at least two grips on each longitudinal side of the electronic component grip under the fixing rails. Each fixing rail has at least one hole allowing the grips to be introduced vertically in relation to the support, in a direction Y, with the grips advancing in direction Z. The holes are configured in such a way that the advancing grips can pass through them during assembly without leaving the support. | 7 |
FIELD OF THE INVENTION
[0001] The present invention relates to a simple and efficient electrolysis method and device for making electrolyzed water from pure water, and belongs to a field of making functional water by electrolysis without any isolation membrane.
BACKGROUND OF THE INVENTION
[0002] Functional Water is defined by the functional water association of Japan as “a water solution with reproducible and useful functions via artificial methods”. As for various functional water, electrolyzed water is the best known by people at the scientific view, and is deemed by Ministry of Health, Labour and Welfare of Japan (National Ministry of Health of Japan) as the only water with real functions to health. The Ministry of Health of China has authorized to manufacture and sell the electrolyzed water devices. The present invention relates to a field of manufacturing electrolyzed water using the electrolysis method. Negative-potential reduced water and hydrogen-rich water using the electrolysis method are the main types of the electrolyzed water, and also are the main objects of the present invention. The scientists found: the water source from the long-life Villages in the world has the common characters of containing hydrogen and an Oxidation—Reduction Potential ORP thereof being negative, which is called negative-potential reduced water, and generally called reduced water, and afterwards be short for functional water. Such common characters cannot be found in the water source in other areas. Usual river-water, lake-water, tap-water, and drinking water such as purified water in market, distilled water and mineral water, doesn't contain hydrogen, has ORP about +150 mv-500 mv, and has no reducibility. In recent years, based on a lot of scientific reach results and clinical verifications, “medical treatment and nourishing of life using reduced water” based on a principle of effectively removing oxygen free radicals by hydrogen-contained water becomes popular.
[0003] Currently, the devices in the market for manufacturing functional water or reduced water by an electrolysis method, mainly are divided into such two types: with membrane or without membrane, herein, the electrolysis device without membrane is the direction to be developed. However, purified water including distilled water has low conductivity and thus was considered that it was incapable of producing electrolysis current and can not be electrolyzed into functional water or reduced water with negative potential by electrolysis method. After Searching prior patents or devices about electrolyzing water with or without membranes, no actual solutions were found to solve the technical problems of effectively producing functional water or reduced water with negative potential from purified water by electrolysis method. In consideration that purified water is widely drank, and water source with a low-conductivity close to purified water widely exists, it is very urgent for human being to solve the electrolyzing technical problems of producing reduced water adapted for purified water. To resolve the problem, a long-time researches are conducted by the applicant, and finally produces a key breakthrough at both theory and practice.
SUMMARY OF THE INVENTION
[0004] The present invention provides a simple electrolysis method and a device thereof for effectively making electrolyzed water adapted to purified water including distilled water, and relates to a field of electrolyzing water without a membrane.
[0005] Why was it always believed that pure water including distilled water cannot produce electrolyzed functional water by the electrolysis method? The applicant finds that the main reason is that the pure water's conductivity is considered near zero, using the existing electrolysis method and the device thereof, electrolysis of pure water including distilled water has a current about zero, thus cannot be performed. A new and simple electrolysis method and a device thereof provided by the applicant, can increase the conductivity of pure water in the market including distilled water without any artificially-added additives, thus can form a circularly-increasing current of electrolysis, in such way to realize electrolysis of pure water including distilled water, and effectively making electrolyzed water which is pure reduced water with a relatively-high negative potential, and can be used for people to drink, cure and nourish his life. Weak acidic reduced water with a negative potential can also be manufactured in the present invention, which can be used for anti-oxidation beauty and skin care; the present invention can be used to produce electrolyzed water such as hydrogen-rich water etc., or can be used in water treatment or the like; which is advantageous for human's health, and has outstanding advantages of energy conservation and environment protection.
[0006] The present invention is based on three new discoveries of the applicant:
[0000] As the first new discovery, manufacturing electrolyzed water or reduced water via the electrolyzing water method substantially is to transfer a power energy from a power supply to a functional activation energy or a reduction-activation energy of water, the reduction-activation energy and making a reduced water in a negative potential as embodiments for key illustration in the present invention. Main indicators for evaluating reduction-activation energy include: active hydrogen content, with a measuring unit of ppb/L or ppm/L; an Oxidation-Reduction Potential of water, namely ORP, with a measuring unit mV of voltage; and an ORP negative potential also called a negative potential. Generally, if water has a relatively high active hydrogen content and negative potential, then the reduction-activation energy of water namely an anti Oxidation-Reduction of water is relatively strong. The hydrogen content and the ORP negative value are called by the applicant as indictors of reduced water or negative-hydrogen reduced water. The intensity and time of electrolysis current applied are necessary for the power energy to be transferred into activation energy so as to obtain a relatively-high indicator of reduced water. In an electrolyzed water production device, a distance between an electrolytic cathode and an anode thereof is closer, and areas of both the cathode and the anode are lager, then an impedance of water is lower thus the electrolysis current will be higher at the same electrolyzing voltage; in other words, the electrolysis current is inversely proportional to the distance between the cathode and the anode, and is proportional to effective areas of the cathode and the anode; this discovery is vitally important to electrolyze pure water and distilled water with a very-low conductivity.
[0007] As the second discovery, a conductivity of pure water including distilled water in the market is not absolutely zero, namely there are always traces of impurities besides water molecules, some electrolyzed impurities will release electrons, which can increase conductivity, and more electrons can be released as electrolysis repeated, which will increase the electrolysis current. The practical test shows: if a distance between the cathode and the anode is lower, impurities can be better electrolyzed, and then the electrolysis current will increase higher. The traces of impurities are shorted as impurities by the Applicant.
[0008] As the third discovery, impurities in pure water including distilled water, can be electrolyzed to produce free electrons and ion particles, which is not only useful to produce and increase the electrolysis current, but also is very important to produce the indicator of reduced water namely to produce more hydrogen H, hydrogen gas H 2 , and specially to produce negative hydrogen ion H − . Such Principle is described as follows: in the electrolyzed water production device, water molecules are electrolyzed to H + and OH − , OH − can be further electrolyzed into O, H, electron e − etc., while the impurities are electrolyzed to release lots of free electrons e − , which can increase chances that H + +e − →H and H+e − →H − , thus hydrogen content in water is increased; increased H − content can strengthen an ability of water of releasing electrons or anti-oxidation and reduction, and then the ORP value becomes negative from positive. Which cannot be ignored that: some ion particles electrolyzed from impurities are very import for stable existence of negative hydrogen ions H − ; H or H − electrolyzed from OH − within a carrier of ion particles of impurities can exist for a relatively long time, H using ion particles of impurities as carriers thus has more chances to combine free electrons to become H − ; professionals of Japan Sanetaka Shirahata and Shigeo Ohta had some ideas about such phenomenon, which is a main reason for the electrolyzed water whit a relative-high indicator of reduced water. Those three discoveries above are generally called as “a principle of making reduced water via water impurities”, and shortly as an electrolysis principle of water impurities, which discloses a nature and key of making reduced water using water-electrolysis method. In fact, when reduced water is electrolyzed from non-pure water, impurities in water are electrolyzed and also produce electrolysis current and specially form the indicator of the reduced water; however, there are so many impurities in non-pure water as nameless hero and that cannot be focused and deeply known.
[0009] As the above three discoveries namely electrolysis principle of water impurities, a method to electrolyze pure water in the present invention has such characters of: first, a reasonably closest distance possible between the cathode plate and the anode plate, second, largest equivalent areas possible of both the cathode plate and the anode plate, a greater electrolysis current possible at a certain electrolysis voltage such as a safety voltage and other corresponding conditions. On the other hand, the closest distance between both plates shall be limited to a necessary water flowability during electrolysis, because a reasonable water flowability is advantageous for repeated electrolysis of trace impurities in water, which can increase more free electrons and the electrolysis current. Certainly, higher electrolysis voltages can also increase the electrolysis current, but it has some limitations in practical application. Experiments show that: in a water container with a practical area and a reasonable structure of both the cathode plate and anode plate, the distance between both plates become narrow to a range of 0.5-0.1 mm, the electrolysis current of pure water in the market including distilled water may be about 60-200 mA or even higher, and pure reduced water with a relatively-high indicators is able to be produced within several minutes. While in the existing electrolyzed water production device, the distance between both plates or an equivalent distance thereof usually is above 10 mm, even greater, a relatively-high impedance will be formed between both plates during the electrolysis of pure water including distilled water, the electrolysis current is about zero or just several mA; even electrifying for a long time, a result of electrolysis cannot be better. Some literature disclosed that: there was activated carbons in water able to release electrons during electrolysis in the existing electrolysis device, which could increase current and the indicator of reduced water; however experiments have discovered that: it is a misunderstanding to a temporary effect of the activated-carbon pollution or residual impurities, when pure water was produced several times, or activated carbons were completely cleaned therefrom, the impurity pollution or residual impurities were greatly reduced, the electrolysis current would be reduced to several mA, the indicator of reduced water became worse; for which the reason is that the distance between both the cathode plate and the anode plate is relatively far such as above 2 mm, or even more, activated carbon itself capable of releasing trace impurities are hardly ionized to produce free electrons under a safety voltage, it is more difficult to obtain a relatively-high indicator of reduced water. However, activated carbon itself capable of releasing trace impurities can be ionized to produce free electrons under a safe voltage in the device of the present invention. Actual measured indicator of reduced water by electrolyzing pure water at two different distances between both plates and with/without activated carbon are listed in the following Table 1:
[0000]
TABLE 1
Actual measured indicator of the indicators of reduced water at different
distances between both plates and with/without activated carbon
distance between
distance between
both cathode
both cathode
plate and anode
plate and anode
plate = 0.3 mm
plate = 0.2 mm
without
with
without
with
structural characters
activated
activated
activated
activated
testing items
carbon
carbon
carbon
carbon
indicators of
ORP (mv)
−231
−425
159
148
reduced
H content
262
457
0
0
water
(ppb)
electrolysis current
80
250
3
8
(mA)
Remark:
electrolysis is operated for 3 minutes, at a normal temperature, with raw water: ORP = +237 mV, a content of H = 0, pH = 5.5
[0010] Thus, the technical problems of producing reduced water with negative potential from pure water including distilled water are well resolved according to the principle of electrolyzing impurities which is discovered by the applicant of the present invention.
[0011] As for an electrolysis method of pure water including distilled water provided in the present invention, why the electrolysis current is circularly increased and an better electrolysis effect is obtained? The most important reason is that: the shorter distance possible between both electrode plates reduces the impedance between both plates, trace impurities in pure water are easily electrolyzed by a local strong current at a narrow gap between both plates, thus lots of electrons are released, and then a relatively-high initial electrolysis current is obtained, therefore, more water molecules H 2 O are electrolyzed into OH − and H + , OH − is further electrolyzed to O, H + and e − at the anode plate, and the electrolysis current is further increased; the greater electrolysis current is able to prompt more impurities and water molecules to be electrolyzed, then the electrolysis current is further increased again, in such a repeating manner, then the electrolysis current is increased to a maximum. The maximum of the current is up to a composite factor of water quality, a structure of the electrolysis and water quality in the present invention; a good water flowability inside and outside of the gap between the cathode plate and the anode plate greatly influences the indicator level of reduced water, as for this, the applicant will give a detail description in following to the fourth discovery.
[0012] The present invention focuses on electrolyzing impurities in pure water to release electrons and particle carriers so as to produce reduced water, and discloses technical solutions to produce electrolyzed water from raw water with a low conductivity: via reducing the gap distance between both plates and increasing effective areas thereof as possible, without any additives, pure water including distilled water can be efficiently electrolyzed to reduced water with a high activated energy and a negative potential; the gap distance between the different plates is reasonably reduced as possible, it is able to be narrow to 0.1 mm or least if necessary, which is outstandingly advantageous for increasing activated energy of electrolyzed water so as to realized energy conservation and environment protection. Via comparison practical experiments and scientific analysis to the electrolysis device of the present invention with the existing technique of electrolyzing water, the great advantages of the present invention at least relates: firstly, at a comparable quality and value of both device, the device of the present invention has energy conservation of 70%-90%, 60%-90% volume reduction, and 20%-30% water conservation. Secondly, pure reduced water at a negative potential is able to be produced at a low cost in the present invention, such technological achievement is never available before; it is necessary to add some additives such as electrolysis promoting agent to the existing electrolysis device so as to electrolyze and produce pure water though filtration, thus the prior device couldn't be produced pure reduced water at negative potential, but had a risk of the additive safety. Thirdly, the present invention are able to produce alkaline or acidic electrolyzed water, also able to produce such reduced water with alkalinity near raw water while the indicator of reduced water is independent of the alkalinity, which are adapted for most people to drink. However, the prior electrolyzed water production device was only able to produce alkaline reduced water, and the relation between the indicator of reduced water and alkalinity are tight; if a relatively-high indicator of reduced water was selected, water would have a PH value exceeding 9 and be strongly alkaline, which was not adapted for people to drink. A fourth advantage, the present invention is able to greatly increase the electrolysis efficiency of non pure water, can be applied to produce functional water such as hydrogen-rich water for environmental protection and cleaning, which are advantageous to health and environment of human being.
[0013] There are another two discoveries based on the electrolysis principle of trace impurities in water, which are very import to direct the techniques of the present invention:
[0000] the fourth discovery, a structural configuration of both the cathode plate and the anode plate shall be most beneficial for a reasonable water flowability between plates during electrolysis, so that more impurities can enter the gap between plates and be electrolyzed, the indicator of reduced water can accordingly be produced and increased, which is very important for the present invention to provide a practicable electrolyzed water production device with a high efficiency and a high quality and value. “Areas of both plates are configured to be properly asymmetric and unequal”, such structure of the electrolyzed water production device can obtain reduced water with a high indication thereof, and can also reduce the device cost. The configuration of asymmetric area shall be most beneficial for the ion cluster and gas bubbles generated from water molecules being electrolyzed between both plates to quickly spread from edges of both plates upwards. Therefore, if configured as an upper plate and a lower plate, an area of the upper plate shall be appropriately smaller than that of the lower plate, but not much smaller, since the effective electrolysis areas of the both plates are limited by the area of the smaller plate, if much smaller, the electrolysis current will be much smaller and then influence the improvement of the ORP negative value, lose more than gain finally. Experiments verify that: if a structural configuration of the both plates with a smaller upper plate and a larger lower plate, or with a plurality of upper plates of small areas, water molecules between both plates are electrolyzed to ion group, hydrogen and oxygen will diffuse upwards or sideward from the edge of the plate of the smaller area under an electric field of the lower plate, in such way that water molecules and ion cluster flow in the gap between both plates, which is beneficial for more water molecules and impurities to be electrolyzed, so that electrolysis efficiency can be improved. The edge of the upper plate is configured as a curve for increasing a length thereof, which are more beneficial for ion group and gas bubbles to flow outwards so as to improve electrolysis efficiency. Otherwise, if the upper plate has a larger area while the lower plate has a smaller area, hydrogen and oxygen flow to the edge of the plate with small area, will be stopped by the broader area of the upper plate, and then cannot flow upwards smoothly, bubbles will remain round the edge of the plate of smaller area, which is not beneficial for ion clusters and gas to flow in the gap between both plates; ion groups has poor flowability, are remained in the gap between plates and generated by water molecules electrolyzed, will be recombined into water molecules most likely, while reduction of ions will substantially decrease the chance of forming oxygen and hydrogen and particularly decrease the chance of forming negative hydrogen, which substantially decreases the electrolysis efficiency. The indicator of reduced water is substantially worse than that of the upper plate with larger area while the lower plate with smaller area. If the efficient electrolysis areas of both plates are symmetrical and both plates have overlapped edges thereof, it will also not very beneficial for ion group and gas bubbles to spread between the plates, and the indicator of reduced water is inferior to that of the upper plate with larger area while the lower plate with smaller area. The applicant discovers that: the upper plate is configured with a smaller area while the lower plate is configured with a larger area, the upper plate is configured as a cathode plate while the lower plate is configured as an anode plate, can obtain a relative-high indicator of reduced water. The reason is that: the larger lower plate as the anode plate can attract more electrons e − , H − , OH − , thus more OH − can be electrolyzed to O, H − , H, e − at a joining place of the anode plate and a lower edge of the upper plate, and all of which can increase the chance of forming H − , and furthermore can help H, e − to spread transversely and positive ions to spread upwards, the flowability of ions are improved, therefore, the indicator of reduced water can be effectively increased. Otherwise, if the cathode is configured as a lower plate with a larger area, there is no advantage described above, thus the indicator of reduced water become worse. Comparing to both plates being horizontally or vertically disposed, the vertical plates are more beneficial for electrolyzed water to flow, since vertical plates, or slightly-inclined gaps between the smaller upper plate and the larger lower plate, are more beneficial for gas bubbles generated from ionization of water molecules to flow upwards so as to increase flowability of water, therefore, a relatively-high indicator can be obtained. Larger or smaller areas of the cathode plate or the anode plate are dependent on a shape, a substantial area and a structure of the plate. When the area of the anode plate is larger than the area of the cathode plate, the efficiency of producing electrolyzed water may be high, or may be just converse. The principle depends that: areas of both plates are unsymmetrical and then water electrolysis at the cathode and anode plates are unsymmetrical, in comparison to symmetrical electrolysis, H − or H ions have less chance to be recombined into H 2 O or H 2 , while H has more chance to combine electrons released from impurities into H − , and the indicator of reduced water is able to be greatly improved. Indicators of reduced water for three electrolysis advices with different plate areas and structures are listed in table 2, in the first structure, the anode plate has an area greatly larger than that of the cathode plate and the cathode plate is disposed above the anode plate; in the second structure, the anode plate with a larger area is disposed above the cathode plate with a smaller plate; in the third structure, both the cathode and anode plates have the same area.
[0000] TABLE 2 Comparison of indicators of reduced water for three electrolysis devices with different plate areas and structures 1 st 2 nd 3 rd The Electrolysis Devices structure structure structure Indicators of ORP (mV) −201 +52 −129 Reduced Water H content (ppb) 310 0 138 Remark: except for area difference for the small plate, the above three electrolysis devices are the same for other conditions; electrolysis is operated for 3 minutes, at a normal temperature, with raw water: ORP = +176 mv, a content of H = 0, pH = 5.5
Therefore, testing result is consistent with the above analysis.
[0014] The fifth discovery, an ORP negative value of electrolyzed reduced water is mainly dependent on a content of negative hydrogen. Therefore, one of the important differences of the present invention from the prior art, as a main object of the present invention to resolve such pending problems of water electrolysis, reduced water with rich negative hydrogen and in a high ORP negative value is electrolyzed from pure water even distilled water. H 2 or H or H − were believed by some experts as activated hydrogen to help body for antioxidation, but they argued whether H 2 or H or H − was the activated hydrogen, therefore, it is unknown where the important ORP negative value from. A book titled “ Hydrogen Revolution - Miracle Cure and Clinic Research about Negative Hydrogen Ion ” by Japan experts Taneaki Oikawa and Naitou Mareo issued in 2008, disclosed that the negative hydrogen ions has such double functions of both clearing oxygen free radicals and promoting metabolism; a relation between negative hydrogen and the value of ORP was indirectly mentioned in this book. A presentation titled “Activated Hydrogen” by Japanese professor Sanetaka Shirahata described that H and electrons can be combined due to coexisting in a carrier of metal particles, which has a function of clearing oxygen free radicals. Electrons carried in negative hydrogen ions H − are more easily attracted by an external electric field to be released than electrons contained in H 2 or H; therefore, in comparison to H 2 or H, negative hydrogen ions H − are crucial for the ORP negative value. It is particularly easily for H − to releases electrons or to be combined with oxygen free radicals O + into H 2 O after being taken in human cells, which turns harm into good, and thus H − is a better antioxidant than either H 2 or H. The present invention focus on manufacturing reduced water with a high content of negative hydrogen ions and a high ORP negative value. Table 3 shows the indicator data of the reduced water manufactured by one of devices of the present invention.
[0000]
TABLE 3
A: Indicator dada of Reduced water Manufactured by One of
Devices of the Present Invention
Time for electrolysis
3 min
5 min
8 min
indicator of Reduced
ORP (mV)
−235
−369
−458
water
Content of H (ppb)
286
397
493
B: Indicator data of Reduced Water Changed With Time
after Electrolysis Finished in Table 3A
Time after electrolysis
10 min
120 min
240 min
Indicator of Reduced
ORP (mv)
−442
−397
−176
water
Content of H (ppb)
468
433
266
Remark:
electrolysis works for 3 minutes, at usual temperature, with raw water: ORP = +176 mv, a content of H = 0
[0015] Accordingly, during a process of either electrolytic activation or activation energy reduction after electrolysis, the ORP negative value and the content of H change synchronously, increase or decrease synchronously. The ORP negative value in proportion to the content of H verifies that an ORP negative value is mainly dependent on a content of H, while the content of H may be a sum of the three or two from of H 2 , H or H − , but what's the relation between each of them and the ORP negative value? The present invention based on experiments and research of the applicant, and discloses that an ORP negative value mainly depends on the negative hydrogen, not H 2 or H. Though an instrumentation for content detection of the negative hydrogen in water is not available now, the content of H of the indicator data in the above Tables are obtained from the existing hydrogen dissolution tables, which may contain H 2 , H or H − .
[0016] A relation between the content of negative hydrogen and ORP is confirmed via an exclusion analysis method in the present invention: first, the content of H 2 cannot affect the value of ORP, and has no relation to the ORP negative value, and accordingly can be excluded; second, H easily reacts that: H+H=H 2 , and can be kept in water for a relatively short time, it must be temporary even if H can affect the value of ORP, and accordingly H can be excluded too; experiments in the present invention disclose that the phenomena of generating H 2 bubbles via H+H=H 2 has been finished in several seconds after electrolysis is finished, which verifies that the content of H in water is rapidly reduced so that on H 2 bubbles can be continually generated yet. In fact, the ORP negative value can be kept for a long time while on the contrary, but H cannot keep long time in water after electrolysis. The ORP negative value of the reduced water in the present invention can be kept the same or even higher level even after the reduced water has been deposited for 15 days, which depends the electrolysis method of the present invention to improve the activity of reduced water and to obtain an ORP negative value with a high activation energy. The ORP negative value in the reduced water can be kept long for several hours even the reduced water is exposed to air, which is contrary to the rapid reduction of H in water. Evidently, during manufacturing the reduced water via electrolysis method, the content of H has no close relation to the ORP negative value. Experiments in the present invention disclose that: the ORP negative value of the reduced water manufactured in the device of the present invention mainly depends on the content of negative H, namely Therefore, the variation of the content of H in above Tables 3 can be approximately regarded as a variation of the content of negative H. A main object of the present invention is to improve both the content of H in the reduced water and the ORP negative value. Off was regarded as a factor to affect the ORP negative value, which is not the fact, since a decrease of the ORP negative value has no relation to the change of pH, and both alkaline water and acidic water can be obtain the same ORP negative value using the electrolysis method of the present invention, which verifies that the ORP negative value has no relation with the pH value or the content of OH − .
[0017] Restricted substances such as residual chlorine in reduced water is necessary to be considered in this present invention, particularly, the electrolysis device of the present invention is also adapted for raw water including impure drinking water such as boiled tap water, cool boiled water, direct-drink water, or mineral water, and the indicator of the reduced water will be higher, which accords with the above electrolysis principle of impurities; while due to the varied quality of raw water, residual chlorine in reduced water may be increased, thus an adapted electrode plate configuration is desired to remove residual chlorine. It is a good method to remove residual chlorine or the like that materials with high adsorptivity such as activated carbon are used to absorb residual chlorine and some heavy metal ions in water during electrolyzing water.
[0018] As a basic technical solution, a simple and high effective method and device suitable for pure water including distilled water for producing reduced water with a negative potential are provided, wherein, comprises an electrolysis power supply, and an electrolysis electrode-plate assembly connected with the power supply and immersed in water to be electrolyzed during work, a gap is provided between a cathode and an anode of the electrode-plate assembly; a gap distance thereof is at a range of greater than 0 mm and less than 10 mm, and the gap is designed according to a principle of optimal minimization, the gap distance can be less than 0.1 mm if necessary; an area of the gap between the cathode and the anode are designed according to a principle of optimal maximization within the electrodes assembly; the gap distance in accord with optimal minimization and the gap area in accord with optimal maximization are aimed at that: the electrolysis device at a certain electrolysis voltage, water quality and environment, can strongly electrolyze impurities in water and water molecules, and thus produce lots of free electrons; a relatively high electrolysis current is accordingly obtained. As one of preferable embodiments, the anode and the cathode are respectively configured as a cellular electrode and a comblike electrode capable of being inserted into the cellular electrode. Comb teeth of the comblike electrode substantially correspond to cellular holes of the cellular electrode and can be fitted in the according holes, gaps are defined between surfaces of the comb teeth and surfaces of the cellular holes; the effective gap area between the cathode and the anode approximates to an equivalent gap area between interfaces of the cellular electrode and the comblike electrode plus equivalent gap areas between all of the comb teeth and the cellular holes.
[0019] As one technical solution, a water container in accordance with an embodiment of the present invention, comprises a container with water therein, a cover, a controllable electrolysis power supply mounted in the cover, and the electrolysis electrode-plate assembly mounted in the cover and extending downwards into the container. The electrode-plate assembly comprises three electrodes immersed in water in the container during work. The electrolysis electrode-plate assembly is wrapped by the cathode as a first electrode shaped as a cylinder and produced from stainless steel. The stainless-steel cylinder is open at the top, has a plat bottom with a mesh structure, and thus facilities water to flow inside and outside of the cylinder; the cylinder electrode is connected with a negative electrode as a first output of the controllable power supply via a conductor. The cellular electrode as a second electrode thereof produced from activated carbon or other applicable materials and in a cake-like shape has a diameter adapted to the cylinder cathode, and is horizontally mounted in the middle or upper part of the cylinder cathode; and there is a first gap set between a circumference of the cake-like electrode of activated carbon and an inner circumference of the cylinder cathode. The activated-carbon electrode is connected with a second output of the controllable power supply via a conductor. The electrode plate with comb teeth as a third electrode thereof is mounted below the activated-carbon electrode. The comb teeth have an amount, shapes and distribution corresponding to the cellular holes of the cellular electrode, and are able to be fitted in the corresponding cellular holes. A fourth gap is set between the surfaces of the comb teeth and the surfaces of the cellular holes. A fifth gap is set between a lower surface of the activate-carbon electrode with a cake-like shape and an upper surface of the comblike electrode plate, and the comblike electrode plate has mesh holes, which is beneficial to improve a flowability of water and ions. The effective area of a second gap between the cellular electrode and the comblike electrode approximates to the equivalent area of the fourth gap between all the comb teeth and the cellular holes plus the effective area of the fifth gap. The comblike electrode is connected with a third output of the controllable power supply via a conductor, and a third gap is set between a bottom surface of the comblike electrode and a bottom surface of the cylinder cathode. Gap distance of the first, second or third gaps among the three electrodes are at a range of greater than 0 mm and less than 10 mm, and can be less than 0.1 mm if necessary. Pure water, distilled water or usual drinking water can be electrolyzed into weakly alkaline or acidic electrolyzed water with negative potential via the electrode-plate assembly under a control of the first, second outputs and the negative electrode of the controllable power supply, and the weakly alkaline electrolyzed water has slightly higher or lower alkaline.
[0020] As a second technical solution, water is electrolyzed to reduced water with negative potential using the above basic technical solution in accordance with the present invention. Comprises a section of tubular channel, the controllable electrolysis power supply, and the electrolysis electrode-plate assembly. The electrolysis electrode-plate assembly is the same as the first technical solution above. Water is fed to one end of the tubular channel, through the electrolysis electrode-plate assembly, and is taken out from the other end of the tubular channel. Pure water, distilled water or usual drinking water can be electrolyzed to weakly alkaline electrolyzed water with negative potential and slightly higher or lower alkaline, or can be electrolyzed to acidic electrolyzed water with negative potential, or can be electrolyzed to such reduced water with a pH approximating to the raw water via the electrode-plate assembly under a control of the first, second outputs and the negative electrode of the controllable power supply.
[0021] A third technical solution of the present invention is similar to the first technical solution, just except a difference structure of the electrolysis electrode-plate assembly. In the electrolysis electrode-plate assembly of this technical solution, the first electrode is configured as a number N of letter Es aligned side by side and tightly fitted together, and the second electrode of the electrolysis electrode-plate assembly comprises a number N of horizontally-opposed letter Es aligned side by side and tightly fitted together; accordingly letter Es-shaped electrode and opposed letter Es-shaped electrode are inserted each other via concave-convex means and form plurality of letter Z-shaped gaps communicated each other. The letter Z-shaped gap distance is at a range of greater than 0 mm and less than 10 mm in accordance with a minimization principle, and may be less than 0.1 mm if necessary.
[0022] The structure of the electrolysis electrode-plate assembly is not limited to the above first, second and third technical solutions, other structures of the electrolysis electrode-plate assembly based on a minimization of gap distance and a maximization of the gap area of the gap between electrodes to effectively increase the electrolysis current of water and impurities so as to manufacture the reduced water of electrolyzed water desired can still be covered by the claimed scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The physical embodiments adopted in the present invention will be presented by the following depicted embodiments and accompanying drawings for further explanations.
[0024] FIG. 1 is a schematic view of a simple but effective electrolysis device capable of manufacturing electrolyzed water from pure water in accordance with a first embodiment of the present invention;
[0025] FIG. 2 is a schematic view of the simple but effective electrolysis device capable of manufacturing electrolyzed water from pure water in accordance with a second embodiment of the present invention;
[0026] FIG. 3 is a schematic view of the simple but effective electrolysis device capable of manufacturing electrolyzed water from pure water in accordance with a third embodiment of the present invention;
[0027] FIG. 4 is a sectional view the simple but effective electrolysis device capable of manufacturing electrolyzed water from pure water in accordance with a fourth embodiment of the present invention;
[0028] FIG. 5 is a sectional view the simple but effective electrolysis device capable of manufacturing electrolyzed water from pure water in accordance with a fifth embodiment of the present invention;
[0029] FIG. 6 is a sectional view the simple but effective electrolysis device capable of manufacturing electrolyzed water from pure water in accordance with a sixth embodiment of the present invention; and
[0030] FIG. 7 is a sectional view the simple but effective electrolysis device capable of manufacturing electrolyzed water from pure water in accordance with a seventh embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The First Embodiment
[0031] A water container of the above basic technical solution is used in this embodiment. Referring to FIG. 1 , comprises a water container 14 , a cover 13 of the water container 14 , a controllable electrolysis power supply 12 mounted in the cover 13 , and an electrolysis electrode-plate assembly 18 mounted in the cover 13 and extending downwards into the container . The assembly comprises three electrodes, and is immersed in water during work. The electrolysis electrode-plate assembly is wrapped by a cylinder cathode 1 of stainless steel as one electrode, 1 has a opened top and a bottom with mesh circular holes 15 so as to facilitate water inside and outside of the 1 to flow. The 1 is connected with a negative electrode 15 as a first output of the electrolysis power supply 12 by a conductor 4 . A cellular and cake-like electrode 2 in a diameter adapted to the cylinder cathode 1 is horizontally fitted in a middle or upper part of 1 . There is a gap 7 set between a circumference of the cake-like electrode 2 and an inner circumference of the 1 . The cake-like electrode 2 is connected with an output 16 of the controllable power supply by a conductor. A comblike electrode plate is mounted under the cake-like electrode 2 , and the comblike electrode plate has comb teeth in an amount, shapes and distribution corresponding to cellular holes of the cake-like electrode 2 , and are able to be fitted in the corresponding cellular holes. A gap 22 is set between the surface of each comb tooth and the surfaces of the cellular hole. A gap 8 is set between a lower surface of the cake-like electrode 2 and an upper surface of the comblike electrode plate 2 , and the comblike electrode plate 2 has mesh holes, which is beneficial to improve a flowability of water and ions. A total effective area of the gap between the cake-like electrode 2 and 3 approximates to equivalent areas of a number N of gaps 22 plus the effective area of the gap 8 . The 3 is connected with an output 17 of the controllable power supply 17 by a conductor. A gap is set between a bottom surface of the 3 and a bottom surface of the 1 . A gap distance of each gaps 7 , 8 , 9 , and 22 between the electrodes is at a range of greater than 0 mm and less than 10 mm, is configured according to a minimization principle, and may be configured as less than 0.1 mm if necessary. The outputs 16 , 17 , 15 of the controllable power supply forms control modes 1 , 2 , and 3 via different voltage combinations; and thus pure water, distilled water or usual drinking water can be electrolyzed to weakly alkaline electrolyzed water with negative potentials and slightly higher or lower alkaline or acidic electrolyzed water with negative potentials via the electrode-plate assembly under a control. The 1 is fixedly connected with the negative output 15 of the controllable power supply, and a working process and principle will be described below.
[0032] The control mode 1 in accordance with the first embodiment is used to manufacture weakly alkaline reduced water with slightly higher alkaline. The control mode is characterized that: the output 17 of the controllable power supply is connected with the 15 , 12 provides a positive voltage to the cake-like electrode 2 via the output 16 . Pure water including distilled water and trace amounts of impurities are electrolyzed mainly at the gaps 7 , 8 , and a number N of 22 , and the cake-like electrode 2 as the anode with great equivalent specific surface area advantageously absorb negative chloride ions, and trace amount of impurities in water released from the cake-like electrode 2 are ionized to generate electrons, which is beneficial to increase electrolysis current and to advance the chance of H+e − →H − , and a higher indicator of reduced water is accordingly obtained. During electrolysis, water molecules H 2 O are ionized or recombined to ions or materials such as OH − , H + , O, H, H − , O 2 , and H 2 etc. al. O 2 gas and H 2 gas can continuously rise upwards away from the opened top of the 1 , water and ions flowing in gaps in the 1 can be accelerated, and water and impurities in the container can repeatedly flow through the 7 , 8 and a number N of 22 and are electrolyzed, which is beneficial to increase the electrolysis efficiency. Moreover, the cake-like electrode 2 can strongly absorb negative ions such as H − and OH − , the higher electrolytic strength are provided, the more negative ions such as H − and OH − are obtained, and the more negative ions such as H − and OH − are absorbed by the cake-like electrode 2 ; at the same time, more H+ and e− are combined to H 2 and H 2 rises out from water surface, the advantage of the equivalent area of the anode bigger than that of the cathode is apparent. Therefore, the content of OH − in water is higher than H + after electrolysis; the alkalinity of the reduced water is stronger, the pH value is higher. The content of H − is higher, then reduced water with higher indicator is produced, which is weakly alkaline reduced water with a relatively high alkalinity.
[0033] The control mode 2 in accordance with the first embodiment is used to manufacture weakly alkaline reduced water with slightly higher alkaline. The 12 provides a positive voltage to the cake-like electrode 2 via the output 16 , the output positive voltage is lower than the control mode 1 ; at the same time, provides a higher positive voltage to the 3 through the 17 . Water and impurities are electrolyzed mainly at the gaps 7 and 9 , the positive voltage provide to the cake-like electrode 2 by the 12 is lower than the control mode 1 , the absorbability of the cake-like electrode 2 to OH − and H − are accordingly weakened, thus the alkalinity of reduced water is lower than that via the control mode 1 . The electrolysis at the 9 is capable of supplying H − to balance H − loss due to the weakened absorbability of the cake-like electrode 2 , therefore, slightly-alkaline reduced water with higher indicator is according produced.
[0034] The control mode 3 in accordance with the first embodiment is used to manufacture acidic electrolyzed water. The cake-like electrode 2 is connected with the negative electrode of the 12 via the output 16 and namely is connected with 1 . The provides a positive voltage to the 3 through the 17 . Water and impurities are electrolyzed at the 9 , a number N of 22 , and 8 . The cake-like electrode 2 is connected with the negative electrode of the electrolysis power supply, has strong absorbability to positive ions such as H + , and reduces the chance of H + +e − →H 2 ; at the same time, OH − in water is easily electrolyzed into O and H − . the 9 is relatively narrow, when uses the power supply with a low and safety voltage to supply power source, usually is designed at a range of greater than 0 mm and less than 1 mm, more O 2 and less H 2 rise upwards from an inside edge of the 1 through the 7 , and then a fast flow of water, ion current and impurities are accordingly obtained, which is beneficial for H − generated at the 9 to spread outwards, such manner is repeated, and then the content of H + in water higher is than OH − , and the pH value of reduced water is lower, therefore, acidic electrolyzed water with higher indicator is manufactured.
[0035] Table 4 shows the measured indicator data of alkaline or acidic electrolyzed water with a negative potential from pure water via the three control modes in accordance with this embodiment.
[0000]
TABLE 4
Measured indicator Data of the Reduced water Manufactured from
Pure Water via 3 Control Modes in accordance with this embodiment
Control
Control
Control
Time for electrolysis
mode 1
mode 2
mode 3
Indicator Reduced
ORP (mv)
−657
−523
−210
water
Content of H (ppb)
698
578
267
pH value
9.8
8.5
6.1
Remark:
electrolysis works for 3 minutes, at usual temperature, with raw water: ORP = +167 mv, a content of H = 0, pH = 5.5.
[0036] The structure in accordance with the first embodiment is also applicable for unpurified water to manufacture reduced water in a negative potential, the principle and process is similar to the above. Table 5 below shows the indicator of reduced water produced from drinking water in accordance with this embodiment.
[0000]
TABLE 5
Measured indicator of the Reduced water Manufactured from Drinking
Water via 3 Control Modes in accordance with this embodiment
Control
Control
Control
Time for electrolysis
mode 1
mode 2
mode 3
Indicator of Reduced
ORP (mv)
−762
−650
−189
Water
Content of H (ppb)
798
687
238
pH value
9.8
8.8
6.2
Remark:
electrolysis works for 3 minutes, at usual temperature, with raw water: ORP = +286 mv, a content of H = 0, pH = 7.5.
The Second Embodiment
[0037] The structure in accordance with this embodiment is shown in FIG. 2 , and is another embodiment which manufactures reduced water with negative potential from water via the basic technical solution above. Comprises a section of tubular channel 25 , the controllable electrolysis power supply 12 , and the electrolysis electrode-plate assembly 18 mounted in the channel 25 . The assembly is the same as the first embodiment, the difference is that: the gap distance of 22 is M times longer than the first embodiment; water is fed to a water inlet 26 and through the 18 , and accordingly through the gaps 7 , 8 , and 9 between the electrodes, particularly through a number N of gaps 22 for being repeatedly electrolyzed, and then flows out from a water outlet 27 . The outputs 16 , 17 , 15 of the controllable power supply forms control modes 1 , 2 , and 3 via different voltage combinations; and thus pure water, distilled water or drinking water can be electrolyzed to negative-potential reduced water with different pH value under a control to the electrode-plate assembly. The measured indicator of reduced water in accordance with this embodiment are shown in Table 6 below.
[0000]
TABLE 6
Measured Indicator of the Reduced water Manufactured from Pure
Water via 3 Control Modes in accordance with this embodiment
Control
Control
Control
Time for electrolysis
mode 1
mode 2
mode 3
Indicator of Reduced
ORP (mv)
−301
−210
−104
Water
Content of H (ppb)
332
231
118
pH value
9.5
8.1
6.1
Remark:
electrolysis works for 3 minutes, at usual temperature, with raw water: ORP = +242 mv, a content of H = 0, pH = 5.5.
The Third Embodiment
[0038] The structure in accordance with this embodiment is shown in FIG. 3 , performs similarly to the second embodiment, and is another embodiment which manufactures reduced water with negative potential from water via the basic technical solution. Comprises the section of tubular channel 25 , the controllable electrolysis power supply 12 , and the electrolysis electrode-plate assembly 18 mounted in the channel 25 . The assembly comprises three electrodes, and is immersed in water during work. The first electrode 1 of the electrolysis electrode-plate assembly is a U-shaped cylinder; the 1 has an opened top and a plat bottom with mesh holes 15 so as to facilitate water flowing in the 1 . The 1 is connected with the output port 15 of the 12 via the conductor 4 . The electrode 2 has a structure that a number N of horizontal opposite letter Es are aligned side by side and tightly fitted together. The electrode 3 has a structure that a number N of letter Es are aligned side by side and tightly fitted together. The opposed letter Es-shaped electrode 2 and the Letter Es-shaped electrode 3 are inserted each other via concave-convex means and form plurality of Z-shaped gaps 8 communicated each other. An outer peripheral surface of the 2 and an inner peripheral surface of the 1 form the gap 7 therebetween. The 2 is connected with the output 16 of the 12 via the conductor. An outer peripheral surface of the 3 and the inner peripheral surface of the 1 form the gap 9 therebetween. The 3 is connected with the output 17 of the 12 via the conductor. A gap distance of each gaps 7 , 8 and 9 is at a range of greater than 0 mm and less than 10 mm, and the gap distance is configured in accordance with a minimization principle, and may be less than 0.1 mm if necessary; During work, water flows from the water inlet 26 of the tubular channel 25 into and through the 18 , and through the gaps 7 , 8 , and 9 between the electrodes, particularly through a number N of gaps 22 for being repeatedly electrolyzed, and then flows out from a water outlet 27 of the tubular channel 25 . The outputs 16 , 17 , 15 of the controllable power supply forms control modes 1 , 2 , and 3 via different voltage combinations; and thus pure water, distilled water or drinking water can be electrolyzed to negative-potential reduced water with different pH value under a control to the electrode-plate assembly. The measured indicator of reduced water in accordance with this embodiment are shown in Table 7 below.
[0000]
TABLE 7
Measured Indicator of the Reduced water Manufactured from Pure
Water via 3 Control Modes in accordance with this embodiment
Control
Control
Control
Time for electrolysis
mode 1
mode 2
mode 3
Indicator of Reduced
ORP (mv)
−289
−204
−121
Water
Content of H (ppb)
309
230
143
pH value
9.2
8.2
6.1
Remark:
electrolysis works for 3 minutes, at usual temperature, with raw water: ORP = +263 mv, a content of H = 0, pH = 5.5.
The Fourth Embodiment
[0039] The structure in accordance with this embodiment is shown in FIG. 4 , which is different from the first embodiment that the water electrolysis device or the 12 together with the 18 can be configured as a portable electrolyzed water production device. The 18 can be conveniently placed in water in any container and work under a control of the 12 . The working principle and process of this embodiment are similar to the first embodiment, the 18 can be placed in water in the container such as a cup or a bowl, and then can electrolyze water in the container to manufacture reduced water with different pH and high indicator. The measured indicator of reduced water in accordance with this embodiment are shown in Table 8 below.
[0000]
TABLE 8
Measured Indicator of the Reduced water Manufactured from Pure
Water via 3 Control Modes in accordance with this embodiment
Control
Control
Control
Time for electrolysis
mode 1
mode 2
mode 3
Indicator of Reduced
ORP (mv)
−652
−589
−210
water
Content of H (ppb)
687
613
267
pH value
9.8
8.5
6.1
Remark:
electrolysis works for 3 minutes, at usual temperature, with raw water: ORP = +251 mv, a content of H = 0, pH = 5.5.
The Fifth Embodiment
[0040] The structure in accordance with this embodiment is shown in FIG. 5 , which is different from the first embodiment that: the 12 is mounted in a lower part of the container, the electrodes has simple structures, the 2 is shaped as a cake, the 3 is a conductive plate, the 8 is set between the 2 and the 3 , and a number N of gaps 22 is lacked in comparison to the first embodiment. In accordance with this embodiment is also applicable for the 1 as a metal or nonmetal water container. The working principle and process of this embodiment are similar to the first embodiment, while the function of 22 in the numbers of N is lacked. The measured indicator of reduced water in accordance with this embodiment are shown in Table 9 below.
[0000]
TABLE 9
Measured indicator of the Reduced water Manufactured from
Pure Water via 3 Control Modes in accordance with this embodiment
Control
Control
Control
Time for electrolysis
mode 1
mode 2
mode 3
Indicator of Reduced
ORP (mv)
−451
−418
−203
water
Content of H (ppb)
474
463
247
pH value
9.6
8.4
6.0
Remark:
electrolysis works for 3 minutes, at usual temperature, with raw water: ORP = +242 mv, a content of H = 0, pH = 5.5.
The Sixth Embodiment
[0041] The structure in accordance with this embodiment is shown in FIG. 6 , which is different from the fifth embodiment that: the cylindrical cathode 1 is replaced by the water container 14 ; the structure is simple, and is applicable for the water container 14 from conductive materials such as metal. The working principle and process in accordance with this embodiment is same as the first embodiment, besides lack of a number N of gaps 22 . The measured indicator of reduced water in accordance with this embodiment are shown in Table 10 below.
[0000]
TABLE 10
Measured Indicator of the Reduced water Manufactured from Pure
Water via 3 Control Modes in accordance with this embodiment
Control
Control
Control
Time for electrolysis
mode 1
mode 2
mode 3
Indicator of Reduced
ORP (mv)
−448
−406
−198
Water
Content of H (ppb)
487
440
225
pH value
9.6
8.4
6.0
Remark:
electrolysis works for 3 minutes, at usual temperature, with raw water: ORP = +231 mv, a content of H = 0, pH = 5.5.
The Seventh Embodiment
[0042] The structure in accordance with this embodiment is shown in FIG. 7 , which is different from the sixth embodiment that: the control mode of the controllable electrolysis power supply and the electrolysis electrode-plate assembly are simplified, the 2 is not connected with the 12 , the 12 is connected with the 1 via the output 15 , the output 17 is connected with the 3 and thus puts out the electrolysis voltage; and negative-potential reduced water with different pH values are manufactured meanwhile via a configuration of both the gap distances and the gap areas of the 7 , 8 , and 9 . Only such one control mode is used in accordance with this embodiment, this control mode is characterized that: the 12 supplies the positive voltage to the 3 via the output 17 , and the 1 is connected with the negative electrode of the 12 via the output 15 , thus water and trace of impurities are electrolyzed at the gaps 7 , 8 and 9 . The 2 has the same function as the control mode 2 in the first embodiment, but in difference that the positive voltage at the 2 is dependent upon a voltage division of the 8 and the 7 relative to the voltage to the 3 provided by the 12 via the output 17 , but is not from the output 16 of the 12 . Therefore, the pH value of the reduced water can be changed via using the gap distance of the 8 to control the 2 , or the same via changing the positive voltage and duration from the output 17 by the 12 , and then reduced water with an according pH value is obtained. The working principle and process in accordance with this embodiment is same as the control mode 2 in the first embodiment. The measured indicator of reduced water in accordance with this embodiment are shown in Table 11 below.
[0000]
TABLE 11
Tested Measured indicator of the Reduced water Manufactured from
Pure Water via 3 Control Modes in accordance with this embodiment
Control
Control
Control
Time for electrolysis
mode 1
mode 2
mode 3
Indicator of Reduced
ORP (mv)
−431
−402
−192
Water
Content of H (ppb)
443
430
218
pH value
9.6
8.4
6.0
Remark:
electrolysis works for 3 minutes, at usual temperature, with raw water: ORP = +238 mv, a content of H = 0, pH = 5.5. | A simple and efficient electrolysis device for making electrolyzed water from pure water, comprising a controllable electrolysis power supply, an electrolytic electrode plate assembly connected to said power supply, said component being immersed within the to-be-electrolyzed water when in operation. A gap is provided between an anode and a cathode of the electrolytic electrode plate assembly, the gap distance being greater than 0 mm and less than 10 mm, said gap being designed according to the principle of optimal minimization, being less than 0.1 mm when necessary. The area of the surfaces, on either side of the gap, of the anode and the cathode of the electrolytic electrode plate assembly are designed according to the principle of optimal maximization, within the occupied set space. Also disclosed is a simple electrolysis method for making electrolyzed water from pure water. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to cooking apparatus for grilling food and in particular to an apparatus with dual grills which simultaneously cook food from the top and bottom. Each of the grills comprise an array of gas fired tubes forming level cooking surface.
2. Prior Art
An example of a gas fired grill or broiler may be found in Potts, U.S. Pat. No. 1,294,159. The grill has a rack of tubes arranged to form a planar cooking surface. Combustion gases enter an intake manifold at one end of the tubes and exit an exhaust duct connected to the opposite end of the tubes. The tubes may be enclosed in an oven type chamber and a drip pan is placed below the tubes. Individual tubes may be removed from the rack for cleaning or replacement, but the entire rack of tubes is not easily removed. The food being cooked must be turned periodically to insure that it cooks evenly as heat is supplied only from below.
An example of a gas fired cooking apparatus which simultaneously cooks from above and below is disclosed in Dreyfus U.S. Pat. No. 2,723,617. The racks of tubes in Dreyfus' apparatus are perforated burners which distribute a flame along their length. The pipes are not placed in contact with the food but rather the food is supported on cross bars above the pipes. One disadvantage of the aforementioned design is that the food to be cooked comes in contact with the combustion gases which may impart an undesirable flavor.
In Amici, U.S. Pat. No. 4,442,824 a gas fired apparatus is shown as an upper heat source for an outdoor grill. As in Dreyfus, a flame is distributed along a length of pipe. Small bricks suspended above the food absorb the heat and radiate it downward. Food is exposed to the combustion gases within the grill.
Individual electrical heating elements within a row of tubes are used in the following patents for cooking apparatus:
______________________________________Nissen, et al. U.S. Pat. No. 3,320,873Burstein U.S. Pat. No. 3,448,678Bardeau, et al. U.S. Pat. No. 3,472,156______________________________________
The heated tubes in Nissen, et al. and Bardeau, et al. are in direct contact with the food as with the gas fired tubes used by Potts. Burstein discloses a radiant heat cooker with heated tubes both above and below a conveyor supporting the food. A shortcoming of electrically heated tubes is that they are slower to heat up and slower to respond to adjustments than gas fired cooking equipment
SUMMARY OF THE INVENTION
Therefore, an object of this invention is to provide a gas fired cooking apparatus that does not expose food to combustion gases.
Another object of this invention is to provide a cooking apparatus which grills food both from above and below.
Yet another object of this invention is to maximize heat transfer between the grill and the food being cooked, preferably by direct contact.
Still another object of this invention is to provide a cooking apparatus which is adjustable to accommodate a variety of sizes and shapes of food and is easily disassembled for cleaning.
Accordingly, a cooking apparatus is provided with an upper and lower grill, each made up of a set of hollow tubes. Combustion gases are introduced into the tubes of each grill through an intake manifold. An exhaust fan draws the hot combustion gases through the tubes and out an exhaust manifold. The upper grill is hinged at one edge allowing one to open the apparatus and place food on the lower grill. The upper grill is also vertically adjustable to be placed in contact with the top surface of food lying on the lower grill when the apparatus is closed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the front of the cooking apparatus.
FIG. 2 is an exploded view of the cooking apparatus.
FIG. 3 is a detailed view of the upper grill.
FIG. 4 is a detailed view of the burners for the upper and lower grills.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Without limiting the scope of the invention, a description of the preferred features of the invention is hereinafter set forth.
In general, the cooking apparatus has as an upper and lower gas fired grill supported by a frame. The upper grill may be raised so that steak, chicken and the like may be placed on the lower grill. The upper grill can then be lowered to rest on the food, which is cooked on two sides at once. Each of the grills are made up of a set of hollow tubes. Combustion gases are supplied at one end of the tubes and an exhaust system contains the gases exiting at the opposite end. Suitable gases for heating the tubes are methane, ethane, propane or butane. Other methods for producing hot gases to heat the tubes of the grills may be employed without deviating from the scope of the invention.
Referring to FIG. 1, cooking apparatus 1 has lower grill 2 made up of parallel tubes 3 arranged to form a planar cooking surface. Tubes 3 have an intake end 4 connected to intake manifold 5 shown in FIGS. 2 and 4. Combustion gases are delivered to intake manifold 5 where they are drawn through tubes 3. The combustion gases or exhaust gases exit tubes 3 at exhaust end 6. Exhaust manifold 7 directs the exhaust gases from exhaust end 6 back around the sides of lower grill 2. Exhaust manifold 7 has outlets 8 which engage slotted openings 9 in exhaust ducts 10.
Exhaust ducts 10 are part of frame 11 which support lower grill 2 horizontally. Frame 11 also has back plate 12 with slit 40 to receive intake manifold 5 of lower grill 2. As shown in FIG. 2, lower grill 2 may be disengaged from frame 11 for cleaning or repair. However, during operation, lower grill 2 and the portion of frame 11 to which it is connected, remain stationary.
Upper grill 13 has edge 14 pivotally connected to frame 11. Upper grill 13 has parallel tubes 15 which are arranged in a plane. Upper grill 13 is movable from a first position parallel to and overlying lower grill 2 to a retracted position as shown in FIG. 1, which would allow one access to the food on lower grill 2. Additionally, the portion of frame 11 connected to edge 14 of upper grill 13 is vertically extendable to accommodate various thickness of food between the two grills.
Each of tubes 15 of upper grill 13 have an intake end 16 and an exhaust end 17. Referring to FIG. 3, intake manifold 18 is connected to intake ends 16 of tubes 15. In a preferred embodiment, intake manifold 18 is made up of an elongated cylindrical chamber 19 having a side connected to intake ends 16 and a slotted inlet 20 opposite intake ends 16. Chamber 19 is in communication with intake duct 21 of frame 11. Intake duct 21 has a convex shaped opening 22 which conforms to the shape of chamber 19 shown in FIG. 2. Thus, when upper grill 13 is pivoted on edge 14, inlet 20 of chamber 19 continuously receives combustion gases from opening 22 in intake duct 21. Alternatively, chamber 19 could be concave and opening 22 could be convex.
Combustion gases entering tubes 15 of upper grill 11 exit as exhaust gases at exhaust ends 17. An exhaust manifold 23 is connected to exhaust ends 17 and directs the exhaust gases back around to edge 14. Exhaust manifold 23 has outlets 24 centered on edge 14 which are in communication with openings 25 in exhaust ducts 10. Since upper grill 13 may be vertically adjusted it is important that the flow of combustion gases to upper grill 13 and the flow of exhaust gases to exhaust ducts 10 remain uninterrupted. Referring to FIG. 2, intake duct 10 of frame 11 is vertically adjustable relative to back plate 12 supporting lower grill 2. Additionally, openings 25 in exhaust ducts 10 are covered with plates 26 having flanged holes 27. Plates 26 are connected to intake duct 21 and are slidable therewith.
Referring to FIG. 3, edge 14 of upper grill 13 is separated into chamber 19 and outlets 24 of exhaust manifold 23 by seals 28 shown in the cutaway view. Outlet 24 has neck 29 which is inserted into hole 27 of plate 26 during operation. Upper grill 13 can be disengaged from frame 11 by sliding edge 14 sideways until neck 29 is removed from hole 27 on first one side then the other.
Exhaust gases from both lower grill 2 and upper grill 13 are drawn into exhaust ducts 10. Main duct 30 connects exhaust ducts 10 along the bottom of back plate 12. Referring to FIG. 2, exhaust fan 31 is positioned in main duct 30 to induce a draft through the exhaust system and ultimately to draw combustion gases through tubes 3 and tubes 15 of lower grill 2 and upper grill 13, respectively.
As shown in FIG. 4, frame 11 has a separate means to deliver combustion gases to lower grill 2 and upper grill 13. Burner body 32 is connected to frame 11 opposite intake manifold 5 of lower grill 2. A gas line 33 is connected to burner body 32 which in turn distributes the gas along slot 34. Alternatively, burner body 32 may have a series of holes corresponding to tubes 3 of lower grill 2.
Combustion gas is supplied to intake manifold 18 of upper grill 13 by burner body 35 inserted in intake duct 21. Burner body 35 has slot 36 for distributing gas supplied from gas line 33. Valves 37 and 38 are supplied on gas line 33 to individually control the temperature of lower grill 2 and upper grill 13. Oxygen for combustion is drawn into intake manifolds 5 and 18 to mix with the gas by the pressure differential created by exhaust fan 31.
Referring back to FIG. 1, drip pan 39 is provided below lower grill 2 to collect juices from the food being cooked. Pan 39 may be removed from frame 11 for emptying and cleaning.
There are, of course, many alternate embodiments and modifications which are intended to be included within the following claims. | An apparatus for simultaneously grilling food from above and below is provided having upper and lower grilling surfaces of gas fired tubes. The upper grill is hinged to lift up and provide access to the food and is vertically adjustable to accommodate variations in thickness of the item being cooked. The upper and lower grills are supported on a frame having a supply of combustion gases and induced draft exhaust system. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation in part of U.S. application Ser. No. 08/576,998 filed Dec. 26, 1995, now U.S. Pat. No. 5,575,117 which is a continuation in part of U.S. application Ser. No. 08/204,114, filed Mar. 1, 1994, now U.S. Pat. No. 5,501,054.
BACKGROUND OF THE INVENTION
The invention relates generally to wooden structural members used in construction and more specifically to a reinforcement method for notched wooden beams.
Wooden beams may be used in construction to provide a horizontal span between walls or between walls and a central girder, for example as floor or ceiling joists. In such applications, the grain of the wood is aligned with the horizontal span.
Wood has relatively little strength perpendicular to the grain in comparison to its strength along the axis of its grain. For example, a sample of Douglas-fir might have parallel-to-grain tensile and compressive strengths of 15,600 and 3,470 PSI, respectively, but perpendicular-to-grain tensile and compressive strengths of only 360 and 340 PSI, respectively.
The strength of a wooden beam in a spanning application derives from the fact that the forces experienced by the beam when loaded are primarily oriented along the grain (tension, compression and shear) with essentially no cross-grain tension. This assumes, however, that the beam is supported underneath its ends and that the beam is of essentially uniform cross section without cuts or notches. This latter assumption may not always be true in practice. Beams may be cut or notched in various places to run utilities or to fit against other structural members. Notches that extend a significant distance into the beam may be an unavoidable part of the building's design or may occur from poor construction techniques.
Generally, a notch in a beam causes some of the loading of the beam to be manifest as cross grain tension, a mode in which wood is relatively weak. Additionally, the stress concentration at the notch re-entrant corner produces stresses to initiate and propagate a crack. As a result, if a spanning beam is to be notched, it is necessary to use reduced loading figures for that beam resulting in the need for larger or more beams than would otherwise be necessary. In renovation projects, where beam number and size is fixed, notching of the beams may not be allowable.
BRIEF SUMMARY OF THE INVENTION
The present inventors have recognized that the loss of strength caused by the notching of spanning beams and the like results not only by the lower strength of wood across its grain, but also because of the dynamics of crack propagation where cross grain tensile stresses are concentrated at the apex of an advancing crack. This concentration of tensile stress significantly decreases the effective strength of the beam in what is already its weakest mode.
Accordingly, the present invention provides localized high tensile reinforcement across the grain of the beam and spanning a line of anticipated crack propagation. By blocking crack propagation, the strength of a notched beam is significantly increased. Further, the need for extensive reinforcement of the entire beam is avoided.
Specifically, the present invention provides a structural member formed of a wooden beam having a grain directed along the length of the beam between ends and across a width of the beam between edges, the length and width defining an area of opposing beam faces. The beam is notched and the notch has a first cut starting at an edge and crossing the grain and extending less than the width of the beam and second cut abutting the first cut at a corner. A tensile reinforcing material is bonded to at least one opposing face across a hypothetical split line starting at the corner and extending parallel to the grain where an axis of tensile strength of the reinforcing material is directed across the grain.
Thus, it is one object of the invention to provide a reinforcement technique that addresses the mechanism of crack propagation through lumber at notches in the lumber. A limited amount of reinforcement near the notch can increase the strength of notched lumber for cross grain loads over its entire length by stopping crack propagation.
It is another object of the invention to provide a substantial increase in the effective load carrying capacity of beams without the need for extensive reinforcement of the entire beam.
A second beam, substantially equal in length and width to the first beam, may be bonded to the first beam to sandwich the tensile reinforcing material between the beam and the one face.
Thus, it is another object of the invention to provide a reinforcement for a notch centered within the likely path of crack propagation.
In one embodiment, the flexible fiber reinforcing material is a patch having fibers running along an axis. An adhesive is applied to one side of the patch and indicia is attached to the patch indicating a desired alignment of the patch with wood grain. The flexible fiber patch may be applied to a wooden beam with the axis perpendicular to the grain of a wooden beam.
Thus it is another object of the invention to provide a reinforcement method which may be used on site when notching of beams is necessary. The indicia is used to properly align the patch and the adhesive to attach the patch to the beam after the notch has been cut.
The foregoing and other objects and advantages of the invention will appear from the following description. In this description, reference is made to the accompanying drawings which form a part hereof and in which there is shown by way of illustration, a preferred embodiment of the invention. Such embodiment does not necessarily represent the full scope of the invention, however, and reference must be made therefore to the claims for interpreting the scope of the invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a fragmentary, perspective view of a notched wooden beam showing a projected split line extending from a corner of the notch and showing placement of localized reinforcement per the present invention to span this split line;
FIG. 2 is a simplified elevational view of the beam of FIG. 1 without localized reinforcement showing propagation of a crack along the split line with beam loading;
FIG. 3 is an exploded perspective view of a reinforcement according to the present invention and suitable for application in the field;
FIG. 4 is a fragmentary perspective view of a beam similar to that of FIG. 1 having pre-positioned internal reinforcement along an anticipated spit line; and
FIG. 5 is a perspective view of second beam, similar to that of FIGS. 1, 2 and 4 but having an internal notch.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1, a wooden beam 10, terminating at a first end 14, has grain 12 running along its length. The wooden beam 10 has generally rectangular cross section taken perpendicular to the grain 12 and presents generally parallel first and second opposed faces 16 and 18, respectively. Faces 16 and 18 have lengths commensurate with the length of the beam 10 and heights commensurate with the width of the beam 10. In use, the wooden beam 10 may be positioned with faces 16 and 18 oriented in vertical planes and with the length of the wooden beam 10 extending horizontally.
A notch 20 is cut in the first end 14 starting at a lower edge and is characterized by having a first cut 22 cutting across the grain 12 to a corner 24 within the wooden beam 10. At the corner 24, the first cut 22 meets with a second cut 26, the latter which extends along the grain 12 from the corner 24 toward the first end 14. The first cut 22 extends less than the width of the beam 10 so that the notch 20 provides an overhang portion 28 at near end 14 of the beam 10 such as may rest against a sill plate or the like.
Referring now to FIG. 2, when beam 10 is positioned with the overhang portion 28 resting on top of a support surface 30 (shown schematically as an upward arrow), downward loading on the beam 10 (shown by arrow 32) creates a tensile force (shown by arrow 33) on the material of the beam at the corner 24. The notch 20 causes this tensile force 33 to concentrate at the corner 24 promoting a split 34. The split 34 travels along a split line 36 extending parallel to the grain 12 of the beam 10 and thus along the length of the beam 10.
As the split 34 progresses, its apex 38 continues to define a point of concentrated tensile stress permitting the split 34 to expand further even though the total tensile forces 33, if distributed evenly over the length of the beam would be insufficient to separate the grain 12 of the beam 10.
Referring again to FIG. 1, present invention recognizes that localized reinforcement of the beam 10 crossing the split line 36 can substantially increase the working load of a notched beam 10 in spanning applications. In particular, an inverted L-shaped reinforcement patch 40 having a plurality of fiberglass fibers 42 extending along a fiber axis 44, is attached to one face 16 of the beam 10 by means of an epoxy adhesive 46 applied to the face 16. The L-shape of the patch 40 allows it follow the first and second cuts 22 and 26 of the notch 20.
In particular, a vertical, generally rectangular portion 48 of the patch 40 extends somewhat less than the height of the beam 10 to have a lower extent adjacent to the first cut 22 on the face 16 and an upper extent spanning the split line 36. The fibers 42 and fiber axis 44 are arranged vertically in this portion 48 to cross the grain 12 and the split line 36.
A second portion 50 of patch 40 extends from the upper extent of the first portion 48 along the direction of the grain 12 onto the overhang portion 28. The fibers 42 and fiber axis 44 in this portion 50 are also are arranged vertically to cross the grain 12.
The first portion 48 of the patch 40 serves to check any progress of a crack along the split line 36. The second portion 50 serves primarily as an alignment guide for the patch 40, but also increases the strength of the overhang portion 28 against cross grain and shear forces.
A similar patch 40 may be applied to the opposite face 18 of the wooden beam 10 to oppose the first patch 40 and to provide yet further reinforcement. For pre-manufactured beams 10, these patches 40 may be applied at a factory site.
In an alternative embodiment, the patch 40 shown in FIG. 3 may be adapted to field installation. In this case, the fibers 42 may be attached to a carrier 52 such as a polyester film or the like. An adhesive 46 may then be applied on the opposite side of the carrier 52 and may include a removable backing 54 to expose the adhesive 46 prior to placement of the patch 40 on the beam 10. The adhesive may be an epoxy such as those advertised under the tradename WEST SYSTEM such as is commercially available from Gougeon Brothers, Inc. of Bay City, Mich. A cover sheet 56 may then be placed over the fibers 42 on the side opposite the adhesive 46 to provide indicia 58 indicating proper alignment of patch 40 with the grain of beam 10. In a preferred embodiment, the indicia provides a printed arrow indicating the grain direction in the beam 10 when the patch 40 is properly affixed to the beam 10.
Such a patch 40 may be used on the work site when it is necessary to notch a beam 10 for utilities and the like. When the notch 20 is positioned in the middle of the beam multiple patches 40 may be used on each face 16 and 18 to flank the notch 20 and thus, it may be desirable to produce a right and left handed version of the patch 40 with the placement of the cover sheet 56 and the adhesive 46 reversed in the two versions.
Referring now to FIG. 4, a prefabricated notchable beam 10' may be constructed by ripping a normal beam 10 along its length midway between faces 16 and 18 to separate the beam 10' into two parts. Fibers 42 may be glued with an adhesive 60 to the cut face of one half of the beam 10' across an anticipated split line 36' near the ends 14 of the beam 10'. The fibers may be laid solely cross grain. The same adhesive 58 is then used to join the halves of the beam 10' together again about the fibers 42 to hold and stabilize the fibers 42.
Because the exact location of the notch may not be known in advance, the fibers 42 may be placed to extend along the middle one-third of the width of the beam for the last several feet of the beam 10+ at each end or other locations to accommodate reasonably expected notching operations as the beam ends. The fiberglass fibers 42 as embedded in the beam 10' may be readily cut with ordinary wood saws.
Referring now to FIG. 5, the present invention is also applicable in a beam 10" where the notch 20" is placed between ends 14" where the cuts of the notch start and end at an edge of the beam 10". Here the left and right hand versions of the patch 40 (indicated as 40a and 40b) may be used to reinforce the split lines 36" extending in two directions from the notch 20" along the line of the grain 12.
The above description has been that of a preferred embodiment of the present invention. It will occur to those that practice the art that many modifications may be made without departing from the spirit and scope of the invention. In order to apprise the public of the various embodiments that may fall within the scope of the invention, the following claims are made: | A localized fiber reinforcement places strong tensile strength fibers across a hypothetical split line near notches in beams to curtail split propagation caused by cross-grain tension that may otherwise significantly reduce the strength of a beam used as a spanning member. An adhesive coated patch may be applied after a notch is cut in the beam or fibers may be attached to a beam at a factory near the location of an anticipated notching. | 4 |
BACKGROUND
[0001] The present invention relates generally to fluid control valves for production well equipment. In particular, this invention relates to back pressure valves for reverse cementing applications.
[0002] Production wells typically have valves and valve seats also known as check valves and back pressure valves. These valves are utilized in different applications in various industries including but not limited to the oil and gas industry. Current back pressure valves supply a one direction flow and a negative flow from the other direction. This may be desirable when a controlled flow is important for such purposes as safety well control while placing a casing string and/or tubing in a potentially active well.
[0003] Typical valves may be mechanically manipulated to selectively change the direction of flow during operations and then selectively change the flow direction back to an original direction. Valves are usually manipulated between configurations by mechanical movement of the casing/tubing, or placing an inter string inside the casing/tubing string to apply weight on the valve so as to hold the valve in an open configuration. Other mechanisms for manipulating valves include disabling the valve with a pressure activated ball or plug allowing flow to enter the casing/tubing string. But these valves cannot be reactivated, if desired. Other valves are manipulated when the casing bottoms in the rat hole at the bottom of the well bore so that the valve is mechanically held open by the set down weight.
SUMMARY OF THE INVENTION
[0004] The present invention relates generally to fluid control valves for production well equipment. In particular, this invention relates to back pressure valves for reverse cementing applications.
[0005] More specifically, one embodiment of the present invention is directed to a valve for a well pipe, the valve having the following parts: a valve collar connectable to the well pipe; an index piston coaxially positioned within the valve collar for longitudinal translation within the valve collar between closed, flow-open, and locked-open configurations; a detent in the index piston, wherein the detent restricts fluid flow in a circulation direction through a flow path through the index piston; a spring that biases the index piston toward the closed and locked-open configurations; and a plug of the valve collar that mechanically communicates with the index piston to be in corresponding closed, flow-open, and locked-open configurations.
[0006] According to a further aspect of the invention, there is provided a valve for a well pipe, the valve being made up of different components including: a valve collar connectable to the well pipe, wherein the valve collar comprises an indexing lug; an index piston coaxially positioned within the valve collar for longitudinal translation within the valve collar between closed, flow-open, and locked-open configurations, wherein the index piston comprises an index pattern comprising closed, flow-open, and locked-open positions such that when the indexing lug is positioned at the closed, flow-open, and locked-open positions, the index piston is configured in the closed, flow-open, and locked-open configurations, respectively; a detent in the index piston, wherein the detent restricts fluid flow in a circulation direction through a flow path through the index piston; a spring that biases the index piston toward the closed and locked-open configurations; and a plug of the valve collar that mechanically communicates with the index piston to be in corresponding closed, flow-open, and locked-open configurations.
[0007] Another aspect of the invention provides a method of regulating fluid circulation through a well casing, the method having the following steps: attaching a valve to the casing; running the valve and casing into the well, wherein the valve is in a closed configuration to maintain relatively higher fluid pressure outside the casing compared to the fluid pressure in the inner diameter of the casing; circulating fluid down the inner diameter of the casing and through the valve to the outside of the casing, wherein the valve is manipulated by the fluid circulation to an open configuration; and ceasing the circulating fluid, wherein the valve is manipulated to a locked-open configuration.
[0008] The features and advantages of the present invention will be readily apparent to those skilled in the art upon a reading of the description of the exemplary embodiments, which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] A more complete understanding of the present disclosure and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings.
[0010] FIG. 1A is a cross-sectional side view of an embodiment of a valve of the present invention, wherein the valve is shown in a closed configuration.
[0011] FIG. 1B is a schematic side view of an embodiment of an index pattern and indexing lug, wherein the indexing lug is located in a closed position.
[0012] FIG. 2A is a cross-sectional side view of the valve of FIG. 1A , wherein the valve is shown in a flow-open configuration.
[0013] FIG. 2B is a schematic side view of the index pattern and indexing lug of FIG. 1B , wherein the indexing lug is located in a flow-open position.
[0014] FIG. 3A is a cross-sectional side view of the valve of FIGS. 1A and 2A , wherein the valve is shown in a locked-open configuration.
[0015] FIG. 3B is a schematic side view of the index pattern and indexing lug of FIGS. 1B and 2B , wherein the indexing lug is located in a locked-open position.
[0016] FIG. 4 is a cross-sectional side view of an embodiment of a valve of the present invention fixed in a casing by a cement attachment.
[0017] FIG. 5A is a cross-sectional side view of an embodiment of a valve of the present invention, wherein the valve is shown in a closed configuration.
[0018] FIG. 5B is a schematic side view of an embodiment of an index pattern and indexing lug, wherein the indexing lug is located in a closed position.
[0019] FIG. 6A is a cross-sectional side view of the valve of FIG. 5A , wherein the valve is shown in a flow-open configuration.
[0020] FIG. 6B is a schematic side view of the index pattern and indexing lug of FIG. 5B , wherein the indexing lug is located in a flow-open position.
[0021] FIG. 7A is a cross-sectional side view of the valve of FIGS. 5A and 6A , wherein the valve is shown in a locked-open configuration.
[0022] FIG. 7B is a schematic side view of the index pattern and indexing lug of FIGS. 5B and 6B , wherein the indexing lug is located in a locked-open position.
DETAILED DESCRIPTION OF THE INVENTION
[0023] The present invention relates generally to fluid control valves for production well equipment. In particular, this invention relates to back pressure valves for reverse cementing applications. The details of the present invention will now be described with reference to the accompanying drawings. This specification discloses various valve embodiments.
[0024] Referring to FIGS. 1A, 2A , and 3 A, cross-sectional side views of a valve 1 are illustrated. The valve 1 has several major components including: a valve collar 10 , a detent in the form of a ball cage 20 , an index piston 30 , an index pattern 40 , a spring 50 , and a poppet plug 60 . FIGS. 2A and 3A also illustrate cross-sectional side views of the valve 1 . In FIG. 1A , the valve 1 is shown in a closed position. In FIG. 2A , the valve 1 is shown in a flow-open position. In FIG. 3A , the valve 1 is shown in a locked-open position. FIGS. 1B, 2B , and 3 B illustrate schematic side views of the index pattern 40 . In each of these figures, an indexing lug 11 is shown in a different position as described more fully below.
[0025] Referring to FIGS. 1A, 2A , and 3 A, each of the major components of the valve 1 are described. The valve collar 10 is a cylindrical structure that houses the other major components. The valve collar 10 has three sections, including: the indexing section 12 , the mounting section 13 , and the seat section 14 . The mounting section 13 has female threads at its upper and lower ends, wherein male threads of the indexing section 12 are made up to the upper end of the mounting section 13 and male threads of the seat section 14 are made up to the lower end of the mounting section 13 . The indexing section 12 has a shoulder 15 wherein the inside diameter of the indexing section 12 is smaller below the shoulder as compared to above the shoulder 15 . The mounting section 13 has a stem mount 16 that extends from the inside diameter side wall of the mounting section 13 . The stem mount 16 is an arm having an annular eyelet at its distal end for receiving a stem 33 of the index piston 30 . The seat section 14 has a beveled valve seat 18 for receiving the poppet plug 60 .
[0026] The ball cage 20 is a somewhat umbrella-shaped structure mounted to the top of the index piston 30 that serves as a ball valve type of detent. The ball cage 20 has a support shaft 21 that extends along the longitudinal central axis of the ball cage 20 . The ball cage 20 also has a cylindrical stainer section 22 that has an outside diameter slightly smaller than the inside diameter of the indexing section 12 of the valve collar 10 . The strainer section 22 is mounted to the support shaft 21 via a top plate 23 . The strainer section 22 has a plurality of side holes 24 that allow fluid communication through the strainer section 22 . The top plate 23 also has a plurality of top holes 25 that also allow fluid communication through the ball cage 20 . The ball cage 20 is connected to the index piston 30 via the support shaft 21 , which extends into a recess in the top of the index piston 30 . The support shaft 21 is threaded, welded, or otherwise connected to the index piston 30 . The lower edge of the strainer section 22 sits on the top of the index piston 30 and may also be connected thereto. The ball cage 20 also comprises a plurality of balls 26 , which are freely allowed to move about within the ball cage 20 . The outside diameter of the balls 26 are larger than the inside diameter of the side holes 24 and top holes 25 so that the balls 26 are retained within the ball cage 20 .
[0027] The index piston 30 has a plurality of flow ports 31 that extend through the index piston 30 parallel to the longitudinal central axis of the piston 30 . The inside diameter of the flow ports 31 are smaller than the outside diameter of the balls 26 of the ball cage 20 . An annular seal 32 is positioned in a recessed near the top of the outside circumference of the index piston 30 to form a seal between the index piston 30 and the valve collar 10 . The annular seal 32 restricts fluid flow between the two structures even as the index piston 30 translates longitudinally within the valve collar 10 . The indexing piston 30 also has an indexing J-Slot 34 in its exterior wall. The indexing J-Slot 34 has an index pattern 40 described in more detail below. The stem 33 extends from the bottom of the index piston 30 so as to connect the poppet plug 60 to the index piston 30 through the stern mount 16 . The poppet plug 60 is threaded, welded, molded, or otherwise fastened or connected to the end of the stem 33 .
[0028] As shown in FIGS. 1A, 2A , and 3 A, the spring 50 is positioned concentrically around the stem 33 of the index piston 30 . At its upper end, the spring engages the lower face of the index piston 30 and at its lower end, the spring 50 engages a spring shoulder 17 at the upper edge of the stem mount 16 . In FIG. 1A , the spring 50 is illustrated in a relaxed or expanded position, while in FIG. 2A , the spring 50 is completely compressed. In FIG. 3A , the spring 50 is only partially compressed.
[0029] The poppet plug 60 is connected to a lower most end of the stem 33 for longitudinal movement into and out of engagement with the valve seat 18 of the seat section 14 . The poppet plug 60 has a conical seal surface 61 for engagement with the valve seat 18 . The seal surface 61 terminates in a seal lip 62 that deflects slightly when the poppet plug 60 is inserted into the valve seat 18 . The deflection of the seal lip 62 ensures the integrity of the seal when the valve is closed.
[0030] Referring to FIGS. 1B, 2B , and 3 B, the index pattern 40 defines several lug positions that are used to configure the valve in closed, flow-open, and locked-open positions. Closed positions 41 are located in the lower-most portions of the index pattern 40 . When the indexing lug 11 is located in one of the closed positions 41 , the valve 1 is configured in a closed configuration. Flow-open positions 42 are found in the upper-most portions of the index pattern 40 . As shown in FIG. 2B , when the indexing lug 11 is positioned in one of the flow-open positions 42 , the valve 1 is configured in a flow-open configuration. Locked-open positions 43 are found in a medium lower position of the index pattern 40 . When the indexing lug 11 is in a locked-open position 43 , the valve 1 is in a locked-open configuration. FIG. 3B illustrates the indexing lug 11 in a locked-open position 43 which corresponds to a valve 1 configuration that is locked-open as illustrated in FIG. 3A . FIG. 1B illustrates the indexing lug 11 in a closed position 41 , which corresponds to a closed valve 1 configuration as illustrated in FIG. 1A . FIG. 2B illustrates the indexing lug 1 I in a flow-open position 42 which corresponds to a valve flow-open configuration as illustrated in FIG. 2A .
[0031] FIG. 4 illustrates a valve 1 of the present invention assembled into a casing 2 . The annular space between the valve collar 10 of the valve 1 and the casing 2 may be filled with a concrete or cement attachment 3 to allow the valve 1 to be drilled out of the casing should removal of the valve 1 become necessary. In other embodiments of the invention, the valve 1 may be connected to the casing 2 by any means known to persons of skill. For example, the valve 2 may be stung into a casing collar, or threaded into an internal casing flange.
[0032] The process for operating the valve is described with reference to FIGS. 1A, 2A , and 3 A. When the valve is run into the well, the valve 1 is in the closed configuration with the spring 50 holding the valve 1 closed. In the illustrated embodiment, the spring 50 is compressed between the bottom face of the index piston 30 and the spring shoulder 17 . The force of the spring 50 biases the poppet plug 60 toward the valve seat 18 . In particular, the valve 1 is biased to a closed configuration. With the valve 1 in the closed configuration, the indexing lug 11 is located in a closed position 41 as shown in FIG. 1B . As the casing 2 and valve 1 are run into the well, increasing fluid pressure from below the valve 1 is checked against the poppet plug 60 and is not allowed to enter the inner diameter of the casing 2 .
[0033] When it is desired to open the valve 1 , fluid may be circulated down the inner diameter of the casing 2 to the valve 1 . Due to gravity, fluid moving in the circulation direction, or any other forces in play, the balls 26 within the ball cage 20 seat themselves in the tops of some of the flow ports 31 (see FIGS. 1A and 2A ). The circulating fluid then flows through the remaining open flow port(s) 31 . However, for fluid to flow through the valve 1 , the fluid pressure inside the inner diameter of the casing 2 must increase to overcome the fluid pressure outside the valve 1 and to overcome the bias force applied by the spring 50 . When the fluid pressure becomes large enough, the poppet plug 60 unseats from the valve seat 18 to allow fluid to circulate through the valve. The valve 1 becomes partially open.
[0034] As fluid is circulated through the valve 1 , the remaining open flow port(s) 31 present a relatively restricted cross-sectional flow area, a pressure differential is created across the valve 1 . As the flow rate increases, the pressure differential increases. When the pressure differential becomes great enough to overcome the bias force of the spring 50 , the valve 1 is reconfigured to the flow-open configuration (see FIG. 2A ). In this configuration, the valve 1 is completely open and the indexing lug 11 is driven to a flow-open position 42 in the index pattern 40 .
[0035] The relative movement of the indexing lug 11 and the index pattern 40 , as the valve 1 moves from the closed configuration to the flow-open configuration, is described with reference to FIGS. 1B and 2B . As the poppet plug 60 moves out of the valve seat 18 , the index piston 30 translates downwardly relative to the valve collar 10 and the indexing lug 11 . This relative movement corresponds to the indexing lug 11 moving upward in the index pattern from a closed position 41 to a flow-open position 42 (see FIGS. 1B and 2B ). As the indexing lug 11 approaches the flow-open position 42 , the indexing lug 11 contacts and slides along an upper ramp 44 . As the indexing lug 11 slides along the upper ramp 44 , the index piston, ball cage 20 and poppet plug 60 rotate and translate relative to the valve collar 10 . As long as fluid continues to circulate at a sufficient flow rate through the remaining open flow port(s) 31 from the inside diameter of the casing 2 to the exterior of the casing 2 , the indexing lug 11 is driven to the flow-open position 42 . Simultaneously, the spring 50 collapses and the indexing J-slot 34 moves across the indexing lug 11 so as to position the indexing lug 11 in the flow-open position 42 of the index pattern 40 (see FIGS. 1B and 2B ).
[0036] Fluid flow in the circulation direction through the valve 1 may be continued as long as desired to circulate the well. When flow in the circulation direction is discontinued (pumping stops), the pressure equalizes across the flow ports 31 allowing the spring 50 to push the poppet plug 60 upwards. This upward movement of the poppet plug 60 , stem 33 , and index piston 30 will index the indexing J Slot 34 to either the closed position 41 or the locked-open position 43 . The index pattern 40 has alternating closed positions 41 and locked-open positions 43 . Thus, each time flow in the circulation direction is continued and discontinued, the valve 1 will alternate between a closed configuration and a locked-open configuration. Because the index pattern 40 repeats itself indefinitely in circular fashion, there is no limit to the number of times the valve 1 may opened and closed.
[0037] The relative movement of the indexing lug 11 and the index pattern 40 , as the valve 1 moves from the flow-open configuration to the locked-open configuration, is described with reference to FIGS. 2B and 3B . When fluid flow in the circulation direction is discontinued, the valve 1 is no longed held in the flow-open configuration. The spring 50 pushes the index piston 30 upwardly relative to the valve collar 10 and the indexing lug 11 . This relative movement corresponds to the indexing lug 11 moving downward in the index pattern 40 from a flow-open position 42 to a locked-open position 43 (see FIGS. 2B and 3B ). As the indexing lug 11 approaches the locked-open position 43 , the indexing lug 11 contacts and slides along a lower ramp 45 . As the indexing lug 11 slides along the lower ramp 45 , the index piston 30 , ball cage 20 and poppet plug 60 rotate and translate relative to the valve collar 10 . The spring 50 expands to drive the indexing lug 11 to the locked-open position 43 . Simultaneously, the spring 50 expands and the indexing J-slot 34 moves across the indexing lug 11 so as to position the indexing lug 11 in the locked-open position 43 of the index pattern 40 (see FIGS. 2B and 3B ).
[0038] If the valve 1 had previously been in the locked-open configuration immediately before fluid flow in the circulation direction is started and stopped, the valve will then cycle to a closed configuration. The relative movement of the indexing lug 11 and the index pattern 40 , as the valve 1 moves from the flow-open configuration to the closed configuration, is described with reference to FIGS. 2B and 1B . When fluid flow in the circulation direction is discontinued, the valve 1 is no longed held in the flow-open configuration. The spring 50 pushes the index piston 30 upwardly relative to the valve collar 10 and the indexing lug 11 . This relative movement corresponds to the indexing lug 11 moving downward in the index pattern 40 from a flow-open position 42 to a closed position 41 (see FIGS. 2B and 1B ). As the indexing lug 11 approaches the closed position 41 , the indexing lug 11 contacts and slides along a lower ramp 45 . As the indexing lug 11 slides along the lower ramp 45 , the index piston 30 , ball cage 20 and poppet plug 60 rotate and translate relative to the valve collar 10 . The spring 50 expands to drive the indexing lug 11 to the closed position 41 . Simultaneously, the spring 50 expands and the indexing J-slot 34 moves across the indexing lug 11 so as to position the indexing lug 11 in the closed position 41 of the index pattern 40 (see FIGS. 2B and 1B ).
[0039] In certain embodiments of the invention, the valve 1 may be cycled between closed, flow-open and locked-open configurations an unlimited number of times as the index pattern 40 around the index piston 30 is a repeating pattern without end. In other embodiments of the invention, the index pattern 40 may have more than one locked-open position 43 , such that the different locked-open positions 43 have different heights in the index pattern 40 . Locked-open positions 43 of different heights hold the valve 1 open in different degrees so as to make it possible to provide restricted flow through the valve 1 in the reverse-circulation direction.
[0040] According to one embodiment of the invention, a casing string 2 is deployed with complete well control while making up the casing string 2 and positioning it into the desired location of the well bore. Once the casing 2 is positioned at its desired location and the top end of the casing is secured with safety valves (cementing head or swage) the back pressure valve 1 may be disabled (without casing/tubing movement) allowing flow from the well bore to enter the string and exit from the top of the string which in return will allow placement of desired fluids into the well bore and around the casing string 2 . When the fluid is at the desired location within the well bore the movement of fluid can be stopped by reactivating the back pressure valve 1 .
[0041] Certain embodiments of the invention include cementing float equipment back pressure valves for reverse cementing applications. These valves involve the use of an indexing mechanism to activate and deactivate the back pressure valve allowing fluid movement from desired directions. The activation process may be manipulated as often as desired during operations of running casing in the hole or the actual cementing operations.
[0042] The valve may be activated as follows. First, when the valve 1 is in the normal operation mode (closed position), flow from the outside is checked (see FIG. 1A ). The well may be circulated from the inside of casing to outside without deactivation of back pressure valve 1 . Increased flow rate creates pressure drop across flow ports 31 , thus indexing the valve into the open position (see FIG. 2A ). Releasing the flow pressure allows the lug to hold the valve 1 open (see FIG. 3A ). Flow from either direction can be achieved at this time (circulation or reverse-circulation) (see FIG. 3A ). The valve may be closed again by increased flow rate from the inner diameter to outside of casing/tubing 2 . ( FIG. 2A ) This allows the valve 1 to return to normal operation (no flow allowed from outside to inside). ( FIG. 1A ) This process can be repeated as often as desired.
[0043] The valve 1 allows complete well control while running the casing/tubing 2 in the hole with the ability to circulate the well without manually activating the indexing mechanism. When desired the valve can be locked-open to perform reverse circulation. If or when desired the valve can be activated again to shut off (check) the flow from annuals gaining complete well control again with the ability to release any pressure trapped on the side of the casing/tubing string. The valve can be activated and deactivated as often as desired.
[0044] Referring to FIGS. 5A, 6A , and 7 A, cross-sectional side views of an alternative valve 1 are illustrated. The valve 1 has several major components including: a valve collar 10 , a detent flapper 27 , an index piston 30 , an index pattern 40 , a spring 50 , and a flapper plug 63 . In FIG. 5A , the valve 1 is shown in a closed position. In FIG. 6A , the valve 1 is shown in a flow-open position. In FIG. 7A , the valve 1 is shown in a locked-open position. FIGS. 5B, 6B , and 7 B illustrate schematic side views of the index pattern 40 . In each of these figures, an indexing lug 11 is shown in a different position as described more fully below.
[0045] Referring to FIGS. 5A, 6A , and 7 A, each of the major components of the valve 1 are described. Similar to the previously described embodiment, the valve collar 10 is a cylindrical structure comprising an indexing section 12 , a mounting section 13 , and a seat section 14 . As before, the indexing section 12 has a shoulder 15 . The mounting section 13 has a stem mount 16 that extends from the inside diameter side wall of the mounting section 13 . The stem mount 16 is an arm having an annular eyelet at its distal end for receiving a stem 33 of the index piston 30 . The seat section 14 has a beveled valve seat 18 for receiving the flapper plug 63 .
[0046] As shown in FIGS. 5A, 6A and 7 A, the index piston 30 has a plurality of flow ports 31 that extend through the index piston 30 parallel to the longitudinal central axis of the index piston 30 . At least one detent flapper 27 is positioned at the opening of at least one of the flow ports 31 . An annular seal 32 is positioned in a recessed near the top of the outside circumference of the index piston 30 to form a seal between the index piston 30 and the valve collar 10 . The annular seal 32 restricts fluid flow between the two structures even as the index piston 30 translates longitudinally within the valve collar 10 .
[0047] In this embodiment of the valve 1 , the indexing section 12 of the valve collar also has an indexing J-Slot 34 in its interior wall. The indexing J-Slot 34 has an index pattern 40 . The stem 33 extends from the bottom of the index piston 30 through the stem mount 16 . As shown in FIGS. 5A, 6A , and 7 A, the spring 50 is positioned concentrically around the stem 33 of the index piston 30 . At its upper end, the spring engages the lower face of the index piston 30 and at its lower end, the spring 50 engages a spring shoulder 17 at the upper edge of the stem mount 16 . In FIG. 5A , the spring 50 is illustrated in a relaxed or expanded position, while in FIG. 6A , the spring 50 is completely compressed. In FIG. 7A , the spring 50 is only partially compressed. The flapper plug 63 is connected to a lower most end of the seat section 14 of the valve collar 10 for pivotal movement into and out of engagement with the valve seat 18 of the seat section 14 . The flapper valve seats in the valve seat 18 and is biased to a closed position by a spring as is known in the art. The flapper plug 63 has a conical seal surface 61 for engagement with the valve seat 18 . The flapper plug 63 is opened by the stem 33 when the stem extends through to the seat section 14 to push the flapper plug 63 from its biased position in the valve seat 18 . When the index piston 30 and stem 33 are driven downwardly relative to the flapper valve, the stem extends through the valve seat 18 to push and hold the flapper valve open. In further embodiments of the invention, the poppet plug 60 or flapper plug 63 are replaced with any valve mechanism known to persons of skill.
[0048] Referring to FIGS. 5B, 6B , and 7 B, the index pattern 40 defines several lug positions that are used to configure the valve in closed, flow-open, and locked-open positions. Closed positions 41 are located in the upper-most portions of the index pattern 40 . When the indexing lug 11 is located in one of the closed positions 41 , the valve 1 is configured in a closed configuration. Flow-open positions 42 are found in the lower-most portions of the index pattern 40 . As shown in FIG. 6B , when the indexing lug 11 is positioned in one of the flow-open positions 42 , the valve 1 is configured in a flow-open configuration. Locked-open positions 43 are found in a medium upper position of the index pattern 40 . When the indexing lug 11 is in a locked-open position 43 , the valve 1 is in a locked-open configuration. FIG. 7B illustrates the indexing lug 11 in a locked-open position 43 which corresponds to a valve 1 configuration that is locked-open as illustrated in FIG. 7A . FIG. 5B illustrates the indexing lug 11 in a closed position 41 , which corresponds to a closed valve 1 configuration as illustrated in FIG. 5A . FIG. 6B illustrates the indexing lug 11 in a flow-open position 42 which corresponds to a valve flow-open configuration as illustrated in FIG. 6A .
[0049] In the embodiments of the invention illustrated in FIGS. 5A, 6A , and 7 A, one or more flapper valves 27 are seated in the tops of the flow ports 31 . To allow restricted flow through the flow ports 31 in the circulation direction, at least one of the flow ports 31 is not equipped with a flapper valve. In still further embodiments of the invention, the ball cage 20 or flapper valves 27 are replaced with any valving system known to persons of skill, wherein the valving system provides restricted fluid flow through the flow ports in the circulation direction, and unrestricted fluid flow through the flow ports 31 in the reverse-circulation direction.
[0050] The valve described with reference to FIGS. 5, 6 and 7 is operated in a similar manner as that described for FIGS. 1, 2 and 3 .
[0051] As described herein the detent in the indexing piston takes on many forms. In FIGS. 1A, 2A , and 3 A, the detent is a fewer number of balls 26 than flow ports 31 . In alternative embodiments of the invention, the ball cage 20 retains the same number of balls 26 as flow ports 31 , but each of the balls has grooves in their exterior surfaces so that when the balls 26 lodge or seat themselves in the openings of the flow ports 31 , a relatively smaller amount of fluid passes through the grooves in the balls 26 and into the flow ports 31 . In FIGS. 5A, 6A , and 7 A, the detent is a fewer number of detent flappers 27 than flow ports 31 in the indexing piston 30 . In an alternative embodiment of the invention, the detent has the same number of detent flappers 27 as flow ports 31 , but the detent flapper(s) 27 only partially closes the flow port(s) 31 when the detent flapper(s) 27 moves to a closed position. For example, where the flow port(s) 31 has a circular cross-section, the detent flapper(s) 27 has a half-moon cross-section to only partially close the flow port(s) 31 .
[0052] Therefore, the present invention is well-adapted to carry out the objects and attain the ends and advantages mentioned as well as those which are inherent therein. While the invention has been depicted, described, and is defined by reference to exemplary embodiments of the invention, such a reference does not imply a limitation on the invention, and no such limitation is to be inferred. The invention is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those ordinarily skilled in the pertinent arts and having the benefit of this disclosure. The depicted and described embodiments of the invention are exemplary only, and are not exhaustive of the scope of the invention. Consequently, the invention is intended to be limited only by the spirit and scope of the appended claims, giving full cognizance to equivalents in all respects. | A valve for a well pipe, the valve having the following parts: a valve collar connectable to the well pipe; an index piston coaxially positioned within the valve collar for longitudinal translation within the valve collar between closed, flow-open, and locked-open configurations; a detent in the index piston, wherein the detent restricts fluid flow in a circulation direction through a flow path through the index piston; a spring that biases the index piston toward the closed and locked-open configurations; and a plug of the valve collar that mechanically communicates with the index piston to be in corresponding closed, flow-open, and locked-open configurations. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to an apparatus for imparting desired amount of buoyancy to submerged articles, and more particularly to an apparatus which give buoyancy to such articles as pipe lines to be laid along the bottom of a body of water, thereby to reduce their weight in water and enable more efficient horizontal and vertical movements thereof.
One method of moving weighty items on the bottom of a body of water, or in the water, such as pipeline laying, is to build a working base on land, connecting the pipes at the base, and then successively drawing the connected pipes to the opposite shore through the water.
When the apparent weight in water of the article being drawn through the water or along the bottom is too light, the article may be moved by surges or currents in the water. The article must therefore be suitably weighted, such as by applying concrete to the outer surfaces thereof. However, conversely, if the apparent weight is too heavy, friction is caused between the article being drawn and the bottom of the water, thereby resulting in difficulties of drawing. In the latter case, means are provided throughout the length of the article being drawn to reduce the apparent weight thereof in water. When the drawing is completed, the buoyancy providing means are removed manually by divers.
One problem in, for example pipe laying, using prior art buoyancy means is in the nature and handling of the buoyancy means. When drawing the pipe line from one shore and along the bottom to the opposite shore, the water pressure changes according to the depth of the water. In order to suitably reduce the weight in water, the buoyancy means should maintain constant the buoyancy irrespective of the water depth or changes in water pressure. Also, on a practical basis, the buoyancy means should be easy to transport, store and attach to the submerged article.
Conventional buoyancy means have comprised floats made of steel pipes having both ends closed air-tight and attached to the pipeline, for example, to give suitable buoyancy thereto. The capacity of the floats having such stiff shells, may be kept constant in spite of the changes of water pressure. However, disadvantageously, the prior floats are expensive, and the weight and volume are large so that transportation expense is high and a large storage space is required. Moreover, it is troublesome to attach the prior floats to the pipeline being laid because of their heavy weight; it is necessary to use large scale loading machines, such as cranes. Also, disadvantageously, when removing the prior stiff shelled means from the article being drawn through the water, the floats tend to rapidly surface through the water due to their large buoyancy, thereby resulting in dangerous possibilities of colliding with machinery and workers.
Another prior buoyancy means uses floats of an air tight bag made of synthetic fibric into which air is filled. This prior means presents no problem in transportation or storage; however, disadvantageously, it is difficult to regulate the buoyancy to counteract changes in water depth. Thus, when this means is attached to the article being drawn, the buoyancy is changed adversely to cause either the article to rise or the article to be dragged by friction. This prior means cannot be used for water depths of more than 20 m.
SUMMARY OF THE INVENTION
The present invention aims to eliminate the foregoing and other deficiencies and disadvantages of the prior art.
An object is to provide an apparatus which retains constant the buoyancy by automatically regulating the inside pressure of the floats to compensate for changes of water pressure due to changes in water depth, and which may always give desired buoyancy to the submerged articles in atmospheric air, or from a shallow depth to large depth or vice versa.
Another object is to provide an apparatus imparting buoyancy to a variety of articles, which is light weight, compact, inexpensive and easy to transport and store.
A further object is to provide a buoyancy apparatus which is easily attached to and detached from submerged articles, such as pipelines, and is easily removed from the article in water after completion of the laying or drawing process.
A still further object of the invention is to provide a buoyancy apparatus which is particularly suited for giving buoyancy to pipelines being laid in water, is widely applicable to oceanic structures or other weighty materials in or through water, and to floating of marine transports at or from or to the bottom of water.
The foregoing and other objects and features of the invention are attained in an apparatus comprising one or more floats, which have bag shapes and are made of soft air tight material and furnished on the outer part thereof with means for attaching same to submerged articles, pipes for feeding pressurized air into the floats, and a differential pressure regulating valve disposed close to the floats. The differential pressure regulating valve regulates the amount of pressurized air supplied to the floats via the pipes, when the difference in pressure between the inside of the floats and the outside is lower than a predetermined value, and when the difference is higher than the predetermined value, it exhausts the air to the outside.
Advantageously, the inventive apparatus utilizes the merits of an air bag of soft material to resolve the problem of fluctuations of inside pressure and buoyancy instability caused by the fluctuations, make possible the maintenance of constant buoyancy imparted to the submerged article, irrespective of the atmospheric pressure and depth of water, and if necessary to almost remove buoyancy in water
Other objects and structures and features of the invention will be apparent from the following description.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an explanatory pictorial view depicting application of the invention in imparting buoyancy to a pipeline being laid along the bottom of a body of water;
FIG. 2 is a partial enlargement of the above embodiment of FIG. 1;
FIG. 3 is a side view depicting structure of the float arrangement of FIG. 2 and attachment thereof to a weighty article in water;
FIG. 4 is a partial front view of the embodiment of FIG. 3;
FIG. 5 is a cross-sectional view depicting an illustrative differential pressure regulating valve utilized in the invention;
FIG. 6 is a side view depicting an illustrative float according to the invention; and
FIG. 7 is an enlarged view of the connection shown in FIG. 6.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Turning to FIG. 1, there is depicted a pipe line 1 being laid along the bottom 2 of a body of water and towed from the left shore toward the right shore (see arrow) by a tugboat 3. The pipeline comprises a plurality of section and is assembled first at a base location on the left shore prior to the drawing operation. The buoyancy apparatus according to the invention 4 is connected to the pipe line prior to drawing.
FIGS. 2 to 5 depict in further detail the illustrative apparatus 4, which as shown in FIG. 2, is formed with a soft air-tight material in a bag shape, and is provided as floats 5 to be attached to the pipeline 1. A pipe 6 is provided for supplying pressurized air (from a source not shown) into floats 5. A differential pressure regulating valve 7 is provided close to one of the floats such as the left float in communication with pipe 6.
The floats 5 are cylindrical in shape and are of air tight construction. They are preferably of rubber or synthetic fabric coated with synthetic resin as a basic material. Both end are sealed air tight. The basic material is preferably of plain fabric of 1280 to 1820 deniers, such as nylon, vinyl or Tetoron. The surface of the basic cloth is coated with a thin film of natural or synthetic rubber or synthetic resin. The scale and number thereof are designed in accordance with the weight and volume of the article in the water, to be imparted with suitable buoyancy. When making a large float, a plurality of cylindrical basic cloths 51 (FIG. 6) are connected in an overlapping manner and the basic cloths 52 of a cap shape are interconnected as depicted. If the article in water is a pipeline, the floats are prepared in sufficient number to enable imparting of sufficient buoyancy to the number, weight and length of pipes. The floats may be attached onto the pipes at a suitable distance from each other.
As depicted in FIG. 2 or FIG. 4, the float 5 is wound with reinforcing bands 8 at suitable outer parts thereof, for detachably attaching to, for example, pipelines. Attaching band 9 extends from both ends of each reinforcing band 8 and has catching or connecting means 10 (FIGS. 3,4,6) at its ends for attachment to the pipeline 1. The shape of the catching means may be selected arbitrarily; in the depicted example, it is triangular. Pipeline 1 has a receiving catch 11 (FIG. 3,4) at parts corresponding to the catching means 10, and in the depicted example, such receiving catch 11 is a hook. The hook 11 is preferably welded to a steel band 12 (FIG. 3) wound on the outer circumference of the pipe corresponding to the attaching band 9. The float 5 has a connection 13 (FIG. 2,6,7) disposed at its end to pipe 6.
The end structure is depicted in greater detail in FIG. 7 wherein the cap shaped base cloth 52 is attached at its hole with a rubber plate 40 screwed with a connecting metal 131. Rubber cover 41 is attached to the outer circumference.
The pipe 6 is used to supply pressurized air from a source not shown into the floats 5 via valve 7 and connections 13. Since the article, such as pipeline 1, to which buoyancy is to be imparted may differ in shape, the pipe 6 may differ in configuration. In this embodiment using a pipe line 1, pipe 6 is comprised of a stem pipe 14 disposed along pipeline 1 from the left shore, and a branch pipe 15 having a valve 16 (FIG. 2) disposed at one end thereof and connected to step pipe 14 via valve 7. The pipe 15 is also connected to the floats at the connections 13. Pipes 6 may be of rubber or steel or other suitable material. When the pipes 6 are made of metal, such as steel, they may be welded to the outer periphery of the pipeline 1, or welded to the steel bands 12 (see FIG. 4). When pipes 6 are of rubber or other non-metallic material, they may be detachably held by means of appropriate means at the same positions.
The differential pressure regulating valve 7 is connected to pipes 6 and is located close to float 5. It automatically regulates the inside pressure of float 5. If the difference in pressure between the inside of float 5 and the outside is lower than a predetermined value, pressurized air is supplied into float 5. Conversely, if the difference is higher than the predetermined value, the air in the float is exhausted into the water or atmosphere.
The structural details of the regulating valve 7 are shown in FIG. 5. Valve 7 is defined with an inlet port 17 in communication with pipes 6 (namely branch pipe 14 in the depicted example) and with an outlet port 20 in communication with floats 5, as well as a valve room 18 having a valve disc 21 and a valve disc room 19, disposed between the inlet port 17 and the outlet port 20. The valve disc 21 is slidable within a guiding concave 22 formed at the lower part of the valve room 18 and the valve disc room 19. Within the valve room 18 is a valve seat 23 to contact valve disc 21, is protruded from the upper part, and around the concave 22 a spring 24 is arranged to moderately push the valve disc 21 to the valve seat 23.
There is defined a room 26 with a partition 25 upwards of the valve seat room 19. The room 26 is provided with a diaphragm 27 so that the room 26 is divided into a lower diaphragm room 28 and an upper spring room 29. The spring room 29 is formed with windows 30 communicating with the outside. The partition 25 is formed with a hole 31 to communicate the diaphragm room 28 with the valve seat room 19. The valve disc 21 is provided at its upper portion with a valve stem 32 which protrudes through the partition 25 into the diaphragm room 28. The diaphragm 27 has a hole 33 at its center to provide communication between the diaphragm room 28 and spring room 29. The hole 33 is formed coaxially with valve stem 32. Spring 34 is provided in spring room 29, which pushes the diaphragm 27 to diaphragm room 28 to close hole 33 by means of valve stem 32.
The strength of spring 34 is determined such that when the pressure of the diaphragm room 28 exceeds by a small amount the pressure of spring room 29 (for example 0.5 kg/cm 2 ), the diaphragm 27 is balanced. Thus, the desired pressure may be determined by using spring 34 of a particular strength, and its practical range is preferably about between 0.3 to 1.0 kg/cm 2 . The reason alower limit of 0.3 kg/cm 2 was selected is that a lower strength would render the spring unfunctionable or at best difficult to function. The upper limit was selected because greater strength is difficult to maintain in production of floats having soft properties and high strength. Hole 33 of diaphragm 27 may be directly formed in the diaphragm like a film, but inorder to precisely close the hole and keep the spring 34 stable, the present example uses a middle piece 35 in the diaphragm which is formed with the hole 33 and is caused to serve as a receiving seat for one end of the spring 34.
In laying the pipeline 1, work is done on shore prior to drawing. Steel bands 12 are wound onto the pipes. Successive segments of pipes are connected together to form the pipeline 1. Pipes 6 are arranged along the pipeline 1; floats 5 are suitably positioned along the pipeline at suitable distances from each other, by engaging the catch means 10 disposed on bands 9 with receiving catches 11 to connect the floats to the pipeline 1. Branch pipe 15 is connected to floats 5 through connections 13. The foregoing attachment process can be readily and easily carried out since the floats are light in weight.
Assuming that a part of pipeline 1 is on land together with floats 5 and pipe 6 is filled with pressurized air, the inside of the floats would be under atmospheric pressure. Thus, rooms 28,29 of the diaphragm 27 would be both under atmospheric pressure, so that valve disc 21 descends separately from the valve seat 23 and opens by the pressure force of the spring 35 against the pressure of spring 24. Accordingly, pressurized air is fed into float 5 from outlet port 20 via inlet port 17, valve room 18 and valve seat room 19 to expand the float. When the inside pressure of float 5 reaches the desired value, e.g. a pressure of 0.5 kg/cm 2 , the inside pressure of the float reaches the interior pressure of chamber 28 so that the diaphragm is balanced. The valve disc 21 again contacts the valve seat 23 to check the pressurized air flowing into float 5. Then, the catch band 9 is tensed by expansion of the float 5 and the catch means 10 is not easily removed from receiving catch 11.
When pipeline 1 is drawn along the bottom of the water, as shown in FIG. 1, and the floats 5 are also submerged, water floods into spring room 29 from windows 30 so that the diaphragm 27 is again unbalanced and it is deformed toward room 28, whereby the valve disc 21 is pushed down and pressurized air is caused to flow into floats 5. When air pressure exceeds the water pressure by a predetermined value, the diaphragm is balanced and the valve disc 21 closes. Thus, when pipeline 1 is moved into deeper water, the diaphragm 27 is subjected to greater water pressure and valve disc 21 opens and closes, by repetition of which the pressurized air is fed into the float, and the air pressure is always kept above the water pressure by the predetermined value. Thus, the pipeline 1 is always given a constant buoyancy even in deep water, shallow water or medium depth water, and is smoothly moved without causing any friction with the water bottom 2.
When pipeline 1 is further drawn along the water bottom toward the opposite shore and floats 5 come gradually towards shallow water, the difference in pressure between the rooms 28 and 29 is less than the predetermined value. At this time, the diaphragm 27 is deformed toward compression of spring 34, whereby the hole 33 is separated from valve stem 32 to provide communication between diaphragm room 29 and spring room 30 by open hole 33. Then valve disc 21 contacts valve seat 23 by pressing force of spring 24 and closes. Thus, pressurized air in float 5 flows into spring room 29 from outlet port 20 via hole 31 and hole 33, and the pressure within floats 5 drops until the difference in pressure from water pressure becomes the predetermined value.
Following the changes of water depth during laying of pipeline 1, the pressure of the float 5 is regulated to be above water pressure by a predetermined value, and floats 5 maintain the same volume. After completion of laying of the pipeline 1, a diver opens valve 16, and the air within float 5 is exhausted into the water and the float volume is reduced. When connection 13 is separated and catch means 10 are taken off from receiving catch 11, floats 5 are separated from the pipeline 1 and surfaces. The speed at which the floats surface is moderate and cause no harm. The buoyancy apparatus may also be removed on land. If the end of pipes 6 is released to the atmosphere, valve disc 21 opens by the difference in pressure between valve room 18 and valve seatroom 19 and the pressurized air within the float 5 is released through pipes 6. Thus, there are two ways of removing the apparatus after completion of operation and any one can be selected according to work demands.
The following is an actual example of the invention.
EXAMPLE
I. The inventive apparatus was used to give buoyancy to a pipeline (appx 5300 m) to be laid on the bottom of a sea and to be used for landing crude petroleum.
II. The pipe was 1066.8 mm φ in outer diameter and coated with concrete to be 1318.3 mm φ in outer diameter and 1396 kg/m in weight.
III. The float was cylindrical, of nylon plain cloth coated with natural rubber (FIG. 6) 600 mm φ in diameter and 4 m in length. The differential pressure regulating was set at 0.5 kg/cm 2 of predetermined pressure value and the float was 1175 kg each.
IV. The pipes were connected by welding on land, and the floats were attached thereon at 13 m distance. The pipes were drawn from land to the sea bottom while supplying air into each pipe by using a compressor at 7 kg/cm 2 . The construction of pipeline was accomplished to the opposite shore without any problems even though the water depth varied from zero depth to 36 meters depth of water.
The above mentioned explanation has referred to the reduction of weight in water of the pipeline. Of course, the invention is not limited to such use. The invention can of course be used to float the submerged article to a desired depth for towing; it also can be used to cause submerged articles to surface.
The foregoing description is illustrative of the principles of the invention. Numerous other variations and modifiations thereof would be apparent to the worker skilled in the art. All such variations and modifications are to be considered to be within the spirit and scope of the invention. | An apparatus for imparting suitable buoyancy to submerged articles, such as pipelines, to reduce their weight in water and enable efficient movement thereof. The apparatus comprises at least one float comprising air tight material, pipe for supplying pressurized air thereinto, and a differential pressure regulating valve arranged close to the float and connectable to the pipe for regulating the amount of pressurized air supplied to the float dependent upon the difference in pressure between that in the float and a predetermined value. Advantageously, the apparatus is easily transportable, stored and attached to the items to which it imparts the desired amount of buoyancy; the apparatus also keeps constant the buoyancy regardless of the depth of water, thus, enabling easy and safe moving of submerged articles. | 5 |
FIELD OF THE INVENTION
[0001] This invention relates to an apparatus for storing currency that is not readily retrievable by the carrier. More specifically, to a purse or bag which has an opening allowing currency to be inserted, while not allowing it to be retrieved.
BACKGROUND OF THE INVENTION
[0002] Patrons of gaming houses have always considered winning a privilege. One of the keys to being successful is deciding when to stop playing. Most often a player who has won will continue to gamble in anticipation of winning more. Eventually, they will either win or lose not only the previous winnings but also all of or most of the money they came with.
[0003] Some people have methods to help avoid this dilemma. One such method is the pocket method. This requires that the player place all winnings in one pocket, while only wagering money from another. Once the wagering pocket is empty then the player takes his winnings and goes home. The phallacy of this method is that most players get caught in the frenzy of gaming and begins to skim from the winning pocket until all funds are exhausted. Another variation of this method is to give your winnings to a friend for safekeeping. The problem with this is that most often either the friend skims the winnings or the player returns and encourages the friend to provide them with more money.
[0004] What is needed is a means to safe keep a players winnings, while denying or delaying the release of the winnings to the player. The present invention overcomes the problems as recited above by providing a portable currency bag which allows the winnings to be placed inside and having a locking device to prevent immediate entry by the player.
SUMMARY OF THE INVENTION
[0005] The invention overcomes the problems of the previous methods by providing a portable locking currency bag which is small, durable, and light weight. The currency bag has an opening at one end to allow the winnings to be inside, and a locking system at the other preventing the player from immediately removing the winnings. It is contemplated that the currency bag may either be worn around the waist or as a shoulder bag.
[0006] It is an object of the invention to provide a currency bag.
[0007] It is another object of the invention to provide a currency bag having a locking system that prevents immediate removal of winnings.
[0008] Another object of the invention is to provide currency bag acceptable for use at gaming establishments that allows the deposit of currency.
[0009] An object of the invention is to provide currency bag that can be worn around the waist.
[0010] It is another object of the invention to provide an apparatus which has a timed delay locking system.
[0011] Other features and advantages of the present invention will be apparent from the following description in which the preferred embodiments have been set forth in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] In describing the preferred embodiments of the invention reference will be made to the series of figures and drawings briefly described below.
[0013] [0013]FIG. 1 shows an embodiment of the invention.
[0014] [0014]FIG. 2 shows a detail of the opening of the invention.
[0015] [0015]FIG. 3 shows a detail of the invention.
[0016] [0016]FIG. 4 shows a detail of the timer lock.
[0017] [0017]FIG. 5 shows a detail of the combination lock.
[0018] [0018]FIG. 6 shows a detail of the screwed connection.
[0019] [0019]FIG. 7 shows a detail of the key lock.
[0020] [0020]FIG. 8 shows another embodiment of the invention.
[0021] [0021]FIG. 9 shows a detail of the opening.
[0022] [0022]FIG. 10 shows the tumble mechanism in the container.
[0023] [0023]FIG. 11 shows the tumble mechanism.
[0024] [0024]FIG. 12 shows the spring assembly of the tumble mechanism.
[0025] [0025]FIG. 13 another embodiment of the invention.
[0026] [0026]FIG. 14 shows the rear of the invention.
[0027] [0027]FIG. 15 shows a detail of the locking connection.
[0028] There may be additional structures described in the foregoing application that are not depicted on one of the described drawings. In the event such a structure is described but not depicted in a drawing, the absence of such a drawing should not be considered as an omission of such design from the specification.
DETAILED DESCRIPTION OF THE INVENTION
[0029] In the following description, the present invention will be described in this embodiment as a process for producing shellfish meal. Those skilled in the art will readily recognize that the equivalent of such process and its applicability for all crustaceans.
[0030] Referring to FIGS. 1 thru 7 , the portable currency bag ( 1 ) is shown having an upper portion ( 2 ) made of a hard polymer, metal, plastic, or resin. An opening ( 3 ) allows currency to be deposited within the bag ( 1 ). The upper portion ( 2 ) is connected to a container ( 4 ). The container ( 4 ) is connected to the upper portion ( 2 ) by either glue/epoxy, or stitching. The container ( 4 ) has an opening at one end ( 5 ) that has a locking mechanism ( 6 ). This locking mechanism ( 6 ) can be either a standard key or combination lock. Additionally, the locking mechanism ( 6 ) can be either a time delay locking mechanism ( 6 a ), keyed lock ( 6 b ), screwed connection ( 6 c ), or combination lock ( 6 d ).
[0031] In the preferred embodiment, FIGS. 8 and 9 the portable currency bag ( 8 ) has an upper portion ( 9 ), with an opening ( 10 ) to allow currency to be inserted. FIG. 10 shows the tumble mechanism ( 11 ) is a half moon shaped tray ( 12 ) that catches the currency. The tumble mechanism ( 11 ) also prevents the user from removing the currency once it is deposited. The bottom of the container portion has an opening ( 15 ), which is closed with a locking mechanism ( 16 ).
[0032] In FIGS. 10 - 12 a cutaway of the bag shows the tumble mechanism 11 having a an arm 13 with a spring assembly ( 17 ). The spring assembly ( 17 ) includes an arm ( 18 ) engaged with a spring 19 against a backstop ( 20 ). In operation, the user places the currency in the opening ( 10 ) and turns the lever ( 13 ) loading the spring while depositing the currency into the container ( 14 ). Upon release the half moon tray ( 12 ) returns to position and thus prevents the currency from being removed. To deter entry and vandalism the container portion is made of either tear resistant canvas or leather. The portable currency bag can be worn as either a shoulder bag (FIG. 14), or as a fanny pack (FIG. 15). A detachable shoulder strap ( 21 ) is connected by ring ( 22 ), or fanny belt ( 26 ) can be attached to the fanny belt by slide connector ( 27 ). In this embodiment, the bag ( 30 ) is connected to the fanny belt ( 26 ) by inserting the connector stem into the opening ( 29 ) in the rear of the currency bag ( 30 ). The user then slides the bag down locking into place.
[0033] Further modification and variation can be made to the disclosed embodiments without departing from the subject and spirit of the invention as defined in the following claims. Such modifications and variations, as included within the scope of these claims, are to be considered part of the invention as described.
PARTS LIST 1. Portable Currency Bag 2. Upper Portion 3. Opening 4. Container 5. Container End Opening 6. Locking Mechanism 8. Portable Currency Bag 9. Upper Portion 10. Opening 11. Tumble Mechanism 12. Half Moon Shaped Tray 13. Spring Loaded Lever 14. Container Portion 15. Container Portion Opening 16. Locking Mechanism 17. Spring Assembly 19. Spring 20. Back Stop 21. Shoulder Strap 22. Connector Ring 23. Container 24. Opening 25. Locking Mechanism 26. Fanny belt 27. Connector assembly 28. Connector Stem 29. Currency Bag opening 30. Currency Bag | This invention relates to portable banking apparatus, more specifically to a portable currency bag. The present invention overcomes the problems of garners losing winnings by providing a portable currency bag which allows the winnings to be placed inside and having a locking device to prevent immediate entry by the player. | 0 |
RELATED APPLICATION
[0001] The current patent application is a continuation-in-part application, claiming priority benefit with regard to all common subject matter to U.S. patent application Ser. No. 13/569,987, entitled “ADJUSTABLE BACKSHELL FOR WIRING HARNESS” and filed Aug. 8, 2012. The earlier-filed identified patent application is hereby incorporated by reference in its entirety.
BACKGROUND
[0002] Backshell devices provide a secure connection between a wiring harness and an associated electrical connector. Backshells not only provide strain relief to prevent damage to the termination points of the wiring harness but may also be designed for coupling with and anchoring a braided sheath encasing the wires in the wiring harness to protect the wiring from the effects of electromagnetic interference (EMI).
[0003] The particular design of an electrical or electronic system may require that a wiring harness enter a backshell at a particular angle. For example, some systems require a wiring harness to enter a backshell from a straight orientation, a 45° orientation, or a 90° orientation. To accommodate these different requirements, various configurations of backshells are known, including 0°, 45°, and 90° backshells. Unfortunately, the required orientation of wiring harnesses to their backshells is often not known until the devices are installed, so installers must stock and carry all configurations of the backshells.
[0004] Adjustable backshells have been developed in an attempt to resolve the above described problems, but known adjustable backshells are either difficult to use and adjust and/or overly complicated and expensive.
[0005] Accordingly, there is a need for an improved adjustable backshell that overcomes the limitations of the prior art.
SUMMARY
[0006] The present invention solves the above-described problems and provides a distinct advance in the art of backshell devices by providing an improved adjustable backshell that can be quickly and easily configured to secure a wiring harness in nearly any orientation.
[0007] A backshell constructed in accordance with various embodiments of the invention broadly includes a tubular, open-ended, cable-receiving portion; a tubular, open-ended, connector portion; and a swivel joint interconnecting the cable-receiving portion and connector portion. The cable-receiving portion and connector portion are relatively shiftable my means of the swivel joint so that the cable-receiving portion and connector portion may assume an infinite number of relative positions between a substantially straight and axially aligned position and a 90° position.
[0008] An embodiment of the swivel joint may comprise a first circumferentially extending bearing surface carried by a front end of the cable-receiving portion; a second circumferentially extending bearing surface carried by a rear end of the cable connector portion; and structure operable to maintain the first and second bearing surfaces in mating adjacency during relative swiveling movement of the cable-receiving and connector portions.
[0009] An embodiment of the structure for maintaining the bearing surfaces together may comprise an annular connection flange carried by the connector portion, and a collar formed in the connector portion and surrounding the connection flange. Mating slots are formed in the annular connection flange and the collar to receive a snap-ring or similar fastener for holding the flange and collar together.
[0010] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Other aspects and advantages of the present invention will be apparent from the following detailed description of the embodiments and the accompanying drawing figures.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0011] Embodiments of the present invention are described in detail below with reference to the attached drawing figures, wherein:
[0012] FIG. 1 is a perspective view of a backshell constructed in accordance with a first embodiment of the present invention.
[0013] FIG. 2 is a side elevational view of the backshell positioned in its straight or aligned orientation.
[0014] FIG. 3 is a perspective view of the backshell positioned in its 90° orientation.
[0015] FIG. 4 is a vertical sectional view of the backshell positioned in its straight orientation.
[0016] FIG. 5 is a vertical sectional view of the backshell positioned in its 90° orientation.
[0017] FIG. 6 is a perspective view of the cable receiving portion of the backshell.
[0018] FIG. 7 is a perspective view of the connector portion of the backshell with its locking not removed.
[0019] FIG. 8 is a perspective view of a backshell in its straight orientation, constructed in accordance with a second embodiment of the present invention.
[0020] FIG. 9 is a side elevational view of the second embodiment of the backshell in its straight orientation.
[0021] FIG. 10 is a perspective view along the longitudinal axis of the second embodiment of the backshell in its straight orientation.
[0022] FIG. 11 is a vertical sectional view taken along line 11 - 11 of FIG. 9 of the second embodiment of the backshell in its straight orientation.
[0023] FIG. 12 is a sectional view taken along line 12 - 12 of FIG. 10 of the second embodiment of the backshell in its straight orientation illustrating the interior of a swivel joint.
[0024] FIG. 13 is a perspective view of the second embodiment of the backshell positioned in its right-angle orientation.
[0025] FIG. 14 is an exploded view of the second embodiment of the backshell seen from a first side of the backshell.
[0026] FIG. 15 is an exploded view of the second embodiment of the backshell seen from a second side of the backshell.
[0027] The drawing figures do not limit the present invention to the specific embodiments disclosed and described herein. The drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0028] The following detailed description of the invention references the accompanying drawings that illustrate specific embodiments in which the invention can be practiced. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized and changes can be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense. The scope of the present invention is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled.
[0029] In this description, references to “one embodiment”, “an embodiment”, or “embodiments” mean that the feature or features being referred to are included in at least one embodiment of the technology. Separate references to “one embodiment”, “an embodiment”, or “embodiments” in this description do not necessarily refer to the same embodiment and are also not mutually exclusive unless so stated and/or except as will be readily apparent to those skilled in the art from the description. For example, a feature, structure, act, etc. described in one embodiment may also be included in other embodiments, but is not necessarily included. Thus, the current technology can include a variety of combinations and/or integrations of the embodiments described herein.
[0030] A backshell 10 constructed in accordance with various embodiments of the invention is illustrated in the drawing figures and broadly includes a tubular, open ended, cable-receiving portion 12 ; a tubular, open ended, connector portion 14 ; and a swivel joint 16 interconnecting the cable-receiving portion 12 and the connector portion 14 . The cable-receiving portion 12 and connector portion 14 are relatively shiftable my means of the swivel joint 16 so that the cable-receiving portion 12 and connector portion 14 may assume an infinite number of relative positions between the substantially straight and axially aligned position of FIGS. 1 , 2 , and 4 and the 90° position of FIGS. 3 and 5 .
[0031] Embodiments of the backshell 10 may be used with copper wires, fiber optic cables, or any other conductors. As used herein, the term “wiring harness” includes any number and type of electrical, optical, or other conductors.
[0032] The cable-receiving portion 12 of the backshell is best illustrated in FIGS. 4 and 6 and includes a tubular body 18 having a rear section 20 and a forward joint section 22 . The rear section 20 includes a sheath termination nipple 24 that is formed by a pair of spaced-apart radially enlarged flanges 26 , 28 that define an annular fastener-receiving channel 30 therebetween. The outermost surfaces of the flanges 26 , 28 and the channel 30 may be knurled or otherwise roughened to increase their friction. A sheath of a wiring harness (not shown) as well as the wiring harness=s outer jacket may be stretched over the flanges 26 , 28 and then compressed and held in the channel 30 by a clamp, clip, spring, or other fastener. A slot 32 is formed in the channel 30 for grounding purposes.
[0033] The forward section 22 of the cable-receiving portion 12 includes an obliquely oriented, annular bearing wall 34 provided with a continuous circular groove 36 . The forward section also includes a radially outwardly and forwardly extending peripheral collar 38 equipped with an internal slot 40 . The outermost surface of the collar 38 may be knurled or otherwise roughened to provide a gripping surface for holding and adjusting the backshell as described below.
[0034] The connector portion 14 of the backshell 10 is best illustrated in FIGS. 1 , 5 , and 7 and includes a tubular body 42 presenting a forward section 44 and a rear joint section 46 . The forward section 44 includes a toothed peripheral edge 48 that serves to locate and hold a connector insert as described below and a pair of laterally spaced apart, radially outwardly extending, annular shoulders 50 , 52 . A threaded coupling nut 54 is rotatably coupled to the forward section of the connector portion by spaced-apart inwardly extending collars 56 , 58 . The collars 56 , 58 are positioned on opposite sides of the shoulder 50 and together define an annular channel 60 in which the shoulder 50 is received.
[0035] The forward section 44 also receives and supports a connector insert (not shown) that is configured to mate with a complemental connector on an electrical or electronic device when the coupling nut 54 is threaded over the complemental connector. The connector insert may be a receptacle-type or “female” insert comprising a plurality of receptacles disposed therein or may be a plug-type or “male” insert with a plurality of outwardly extending pins or plugs. The individual wires in the wiring harness enter the rear section 20 of the cable-receiving portion 12 of the backshell and terminate at the rear of the connector insert in a conventional manner.
[0036] The rear joint section 46 of the connector portion 14 includes an annular, obliquely oriented connection flange 62 presenting a bearing wall 64 provided with a continuous groove 66 . In addition, the outboard surface of the flange 62 has a continuous peripheral slot 68 .
[0037] As best shown in FIGS. 4 and 5 , the forward joint section 22 of the cable-receiving portion 12 and the rear joint section 46 of the connector portion 14 are joined by the swivel joint 16 to present the overall backplate 10 . An O-ring 70 is seated within groove 66 , and a metallic snap-ring 72 is inserted into slot 68 . The forward joint section 22 of the cable-receiving portion 12 is then pressed onto flange 62 of the connector portion 14 such that the collar 38 surrounds the flange 62 , and the snap-ring 72 seats into the slots 40 and 68 . In this orientation, the bearing walls 34 and 64 are in close, mating adjacency, with the O-ring 70 captively retained between the grooves 36 and 66 , and with the snap-ring 72 within slots 40 and 68 serving to maintain the rotary connection between cable-receiving portion 12 and connector portion 14 .
[0038] In order to adjust the relative positions of the cable-receiving portion 12 and connector portion 14 , an installer may simply grasp the portions and exert a relative turning or twisting movement until they are in the desired angular relationship. Advantageously, no tools are required to adjust the angular orientation of the backshell. It will be appreciated that the cable-receiving portion 12 and connector portion 14 may assume any position between that shown in FIG. 1 where the longitudinal axes of the portions are in essentially parallel, offset relation, to the 90° position of FIG. 3 . Once positioned in a desired relative orientation, the cable-receiving portion 12 and connector portion 14 may be locked or otherwise held in place by a suitable locking mechanism.
[0039] The components of the backshell may be formed by any suitable materials including synthetic resin materials, metals, and allows and may be of any size to accommodate any type and size of wiring harness.
[0040] A backshell 100 constructed in accordance with an additional embodiment of the present invention is shown in FIGS. 8-15 and broadly comprises a cable-receiving portion 112 , a connector portion 114 , and a swivel joint 116 . The cable-receiving portion 112 and the connector portion 114 are substantially similar to the cable-receiving portion 12 and the connector portion 14 of the backshell 10 described above. The backshell 100 may further include a first tubular body 118 , a rear section 120 , a forward joint section 122 , a sheath termination nipple 124 , a pair of flanges 126 , 128 , a fastener-receiving channel 130 , a first slot 132 , a first bearing wall 134 , a first groove 136 , a first collar 138 , a second slot 140 , a second tubular body 142 , a forward section 144 , a rear joint section 146 , a peripheral edge 148 , a pair of annular shoulders 150 , 152 , a nut 154 , a pair of collars 156 , 158 , a channel 160 , a connection flange 162 , a second bearing wall 164 , a second groove 166 , a third slot 168 , an O-ring 170 , and a snap ring 172 , all of which are substantially similar to the like-named components of the backshell 10 discussed above.
[0041] The swivel joint 116 is similar to but not exactly the same as the swivel joint 16 . The swivel joint 116 may allow the cable-receiving portion 112 to rotate or swivel with respect to the connector portion 114 to achieve an infinite number of orientations of the backshell 100 between a “straight” orientation, seen in FIGS. 8-10 wherein the longitudinal axes of the cable-receiving portion 112 and the connector portion 114 are in essentially parallel, offset relation, and a “right-angle” orientation, seen in FIG. 13 wherein the longitudinal axes of the two portions 112 , 114 are at approximately 90° relative to one another. The swivel joint 16 allows a similar action with the cable-receiving portion 12 and the connector portion 14 of the backshell 10 . However, in order to prevent over rotation, which may damage the wiring or cabling retained within the backshell 100 , the swivel joint 116 prevents rotation of the cable-receiving portion 112 beyond approximately 180°. Furthermore, the swivel joint 116 may include features which allow the backshell to assume a plurality of easily-selected preset orientations. In addition to some of the components listed above, the swivel joint 116 may further include a race post 174 , a race 176 , a detent post 178 , a post collar 180 , and a plurality of detents 182 .
[0042] The race post 174 , as shown in FIGS. 10 , 12 , and 15 , may be generally cylindrical with a sidewall, a first end, and a second end. In an exemplary embodiment, the race post 174 may be positioned on the first bearing wall 134 , which is an inner surface of the first collar 138 of the forward joint section 122 , such that the second end is attached to the first collar 138 and the first end protrudes outward away from the first collar 138 . In other embodiments not shown in the figures, the race post 174 may be positioned on the second bearing wall 164 .
[0043] The race 176 , as shown in exemplary embodiments in FIGS. 10 , 11 , and 14 , may include a channel or recess formed in the surface of the second bearing wall 164 of the rear joint section 146 . In other embodiments not shown in the figures, the race 176 may be formed in the surface of the first bearing wall 134 . The race post 174 may be retained by and slidable within the race 176 . A depth of the race 176 may be equal to or greater than a height of the race post 174 . A width of the race 176 may be equal to or greater than a diameter of the race post 174 . The race 176 may have a generally arcuate shape. An exemplary race 176 may have semi-circular shape and may extend approximately halfway around, or approximately 180° along, the second bearing wall 164 , as best seen in FIGS. 10 and 14 . The race 176 may include a first end 184 and an opposing second end 186 . The race 176 and the race post 174 may be positioned relative to one another such that, when the backshell is in the straight orientation, the race post 174 is aligned and in contact with the first end 184 of the race 176 and when the backshell is in the right angle orientation, the race post 174 is aligned and in contact with the second end 186 of the race 176 .
[0044] The detent post 178 , as best seen in FIGS. 12 , 14 , and 15 , may be generally cylindrical with a sidewall, a first end, and an opposing second end positioned on a longitudinal axis. In some embodiments, the detent post 178 may have threads on an external surface of the sidewall. Furthermore, the first end may include a single slot, a pair of crossed slots, a hex opening, a torx opening, or the like. The second end may have a convex shape with a rounded or hemispherical surface, a pointed or conical surface, a frustoconical surface, a pyramidal surface, a frusto pyramidal surface, or the like. In some embodiments, the detent post 178 may be a set screw, wherein the first end is configured to receive a tool, such as a screwdriver.
[0045] The post collar 180 , as shown in FIGS. 8-10 and 12 - 14 , generally has a hollow cylindrical shape with a single sidewall and may be positioned on an outer surface of the first collar 138 of the forward joint section 122 . Furthermore, a central axis of the post collar 180 may be aligned with an opening in the first collar 138 . In other embodiments not shown in the figures, the post collar 180 may be positioned on an outer surface of the rear joint section 146 and may align with an opening therein. The post collar 180 may include threads on an inner surface of the sidewall. The post collar 180 generally receives the detent post 178 such that the first end of the detent post 178 is accessible above the post collar 180 or through the opening of the post collar 180 and the second end protrudes through the first collar 138 . Rotation of the detent post 178 within the post collar 180 adjusts the longitudinal position of the detent post 178 along the axis of the post collar 180 .
[0046] The detents 182 , as shown in FIGS. 10-12 and 14 , may include concave impressions formed in the surface of the second bearing wall 164 of the rear joint section 146 . In other embodiments not shown in the figures, the detents 182 may be formed in the first bearing wall 134 . The detents 182 may have a rounded or hemispherical shape, a pointed or conical shape, a pyramidal shape, or the like. In an exemplary embodiment of the backshell 100 , there may be nine detents 182 formed in the second bearing wall 164 with an angular spacing therebetween of approximately 22.5°. Thus, from the first detent 182 A to the last detent 182 B, the detents 182 may occupy an angular range of approximately 180°. Since both the detents 182 and the race 176 occupy an angular range of approximately 180° on the second bearing wall 164 , a portion of the detents 182 may be co-located with a portion of the race 176 .
[0047] The swivel joint 116 may operate as follows. When the backshell is in the straight orientation, seen in FIGS. 8-10 , the race post 174 may be aligned and in contact with the first end 184 of the race 176 . And, the first detent 182 A may receive and retain the second end of the detent post 178 , as shown in FIG. 12 . Retention of the detent post 178 in one of the detents 182 provides a resistance to the easy rotation of the cable-receiving portion 112 with respect to the connector portion 114 . The resistance may be adjusted by rotating the detent post 178 in the post collar 180 . For example, the resistance may be increased by rotating the detent post 178 in a first direction, such as clockwise, while the resistance may be decreased by rotating the detent post 178 in a second, opposing direction, such as counter-clockwise.
[0048] A user may adjust the orientation of the backshell 100 by rotating the cable-receiving portion 112 with respect to the connector portion 114 . Generally, when the backshell is in the straight orientation, the user may rotate the cable-receiving portion 112 in only a first direction, such as clockwise, because the race post 174 being in contact with the first end 184 of the race 176 prevents rotation of the cable-receiving portion 112 in the opposite (counter-clockwise) direction. While the user rotates the cable-receiving portion 112 , the race post 174 may slide within the race 176 . The user generally has to apply enough torque to the cable-receiving portion 112 to overcome the resistance provided by the detent post 178 being retained by the first detent 182 A. As the user continues to rotate the cable-receiving portion 112 , the detent post 178 may become aligned with other detents 182 and may be retained, at least momentarily, therein. If so desired, the user may stop rotation of the cable-receiving portion 112 when the detent post 178 is aligned with any of the intermediate detents 182 , or at any other angular position. Once the user rotates the cable-receiving portion 112 approximately 180°, the backshell 100 is in the right-angle orientation, seen in FIG. 13 , and the detent post 178 aligns with and is retained by the last detent 182 B. In addition, the race post 174 contacts and aligns with the second end 186 of the race 176 , thereby prohibiting further rotation in the first direction. When it is desired to return the backshell 100 to the straight orientation, or another angular position, the user may rotate the cable-receiving portion 112 in a second direction, such as counter-clockwise.
[0049] Preventing rotation of the cable-receiving portion 112 of the backshell 100 beyond approximately 180° may prevent damage to the wires or cables retained within the backshell 100 . The wires may twist, rotate, or bend when the cable-receiving portion 112 is rotated to place the backshell 100 in the right-angle orientation. Allowing the cable-receiving portion to rotate beyond 180° would continue to twist the wires—possibly leading to damage. Since the rotation is limited, when the user wants to return the backshell to the straight orientation, he has to rotate the cable-receiving portion 112 in the opposite direction, which untwists and unbends the wires.
[0050] Although the invention has been described with reference to the embodiments illustrated in the attached drawing figures, it is noted that equivalents may be employed and substitutions made herein without departing from the scope of the invention as recited in the claims.
[0051] Having thus described various embodiments of the invention, what is claimed as new and desired to be protected by Letters Patent includes the following: | A backshell includes a cable-receiving portion presenting a front end, a rear end, and a first longitudinal axis; a connector portion presenting a front end, a rear end, and a second longitudinal axis; and a swivel joint operably coupling the front end of the cable-receiving portion with the rear end of said connector portion and operable to permit selective relative movement between the cable-receiving portion and the connector portion such that they may assume different relative positions with the longitudinal axes thereof at correspondingly different angles. | 7 |
This application in the U.S. national stage application of International Application No. PCT/OE96/00476 having an international filing date of Mar. 19, 1996.
FIELD OF THE INVENTION
The invention relates to a method and a device for the process management of a paper machine for the production of paper and/or board, using at least one measuring device for registering physical characteristic values and at least one regulating or controlling device for the operating means used in the paper machine.
BACKGROUND OF THE INVENTION
In the earlier international Patent Application WO 95/08019 A1, which is not a prior publication, a device is proposed for operating an installation specifically for the production of deinked pulp. The installation includes at least one waste paper preparation means, downstream of which a paper machine or at least one dewatering machine is connected. In this case, measuring devices for registering spectral and/or physical characteristic values of the waste paper suspension are already used. Furthermore, regulating or controlling devices are used there for the operating means of the waste paper preparation means. There is also at least one state analyser, designed in the form of one or more parallel neural networks, for the waste paper suspension. The analyzer, by means of the characteristic values of the measuring device, supplies controlled variables for process management to the regulating or controlling devices of the operating means for the waste paper preparation means.
In the case of the device described above for the production of deinked pulp, using as great a proportion as possible of waste paper, there is in particular the problem that the quality of waste paper introduced into the installation fluctuates severely. For example, there can be, in the respective mixture of waste paper, sharply variable proportions of, for example, coloured illustrated paper, gray newsprint, white paper, contaminated paper, old books, for example with adhesive residues, such as telephone directories, cartons, packages, coated papers and contaminations of all types. The device previously described in the earlier Patent Application solves these problems in a satisfactory manner for the waste paper preparation means.
EP-A-0,137,696 discloses a method and an associated device for registering the water content of a paper web during production, in which, via an optical infrared measurement, use is made of the fact that water has an absorption band at 1.94 μm. To this end, a measuring channel and a reference channel having a different wavelength than the water absorption band is used. In addition, U.S. Pat. No. 5,282,131 discloses a system for regulating a pulp washing plant, in which a neuron network is employed to verify predictable process parameters. In the case of both of these documents, therefore, only some aspects of paper production are addressed.
OBJECTS AND SUMMARY OF THE INVENTION
An object of the present invention is to use the measurement principle on which the above described device is based directly in a paper machine. The object is achieved, according to the invention, in that, using the measuring device, spectral characteristic values are registered at different wavelengths on the operating materials of the paper machine. The operating materials are the starting material directly before the flow box on the paper machine and/or the intermediate or final product. The signals from the measuring device for the spectral characteristic values are evaluated by at least one neural network and statements about the product quality are derived therefrom. The statements are, in particular, the quality parameters of the paper or of the board. Signal variables are derived from the statements about the product quality. The signal variables may be used, on the one hand, for feedback control in the so-called stock preparation upstream of the paper machine, and on the other hand, for the feed forward control of the paper machine itself.
In the case of feedback control, the parameters of the stock preparation are adjusted to produce the stock quality necessary for an intended paper or board quality. In the case of feedforward control, on the other hand, the operating means of the paper machine are controlled so that an intended paper or board quality is achieved with a given stock quality.
The result of the invention is to provide, for the first time, the possibility of an on-line measurement using the spectrometer in a paper machine. By suitable evaluation, with determination of the quality values of the paper or the board, the quality-influencing parameters in the stock preparation for the paper machine can also be influenced. The delay times which were produced with the previously normal laboratory measurement are thus dispensed with.
In the associated arrangement, spectroscopes or spectrometers are used, in particular for picking up spectral distributions or overall spectra. The neural networks are used within the context of the invention, specifically for the evaluation of spectral characteristic values. Either the diffuse backscatter intensity or the diffuse transmitted intensity of selected spectral ranges is used as input variables for the neural networks. Further parameters of the stock suspension or of the paper or board, for example, consistency, moisture, grammage and the like, may also advantageously be used as input variables for the neural networks. Output variables from the neural networks are mechanical quality parameters of the paper or board produced, such as in particular, the so-called CMT value, the breaking length, the burst pressure, and other factors which are significant for the practical suitability of the paper. The neural networks can be trained using quality parameters measured off-line in the laboratory.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects and advantages of the present invention will be better understood with reference to the following detailed description of several embodiments thereof, which is illustrated by way of example, in the accompanying drawings, wherein:
FIG. 1 schematically illustrates an embodiment of the invention in the context of a paper producing machine;
FIGS. 2 a and 3 schematically illustrate two partial neural networks for use in FIG. 1 and FIG. 2 b illustrates the use of certain preferred wavelengths as inputs to the neural networks; and
FIGS. 4 to 7 show alternative embodiments for utilizing the data provided by spectrometers.
DETAILED DESCRIPTION OF THE INVENTION
In the figures, identical or identically acting parts have corresponding reference symbols.
In FIG. 1 an installation for producing paper is designated by 1 , which essentially comprises the so-called stock entry 2 , the actual paper machine with flow box 3 , a downstream wire mesh conveyor belt 4 for the transport of the wet paper webs, further roller tracks such as 5 and 6 for drying and winding up a paper web 110 and a size press 9 . In particular, the size press 9 can be arranged between drying devices 7 and 8 . Installations of this type for producing paper are known and in use in practice in a wide range of technical configurations.
In the installation according to FIG. 1 there is a first spectrometer 10 in the region of the stock inlet 2 . The measuring area 11 of the spectrometer 10 is directed onto the stock suspension that is used for the starting material for the paper production. A second spectrometer 10 ′ has its measuring area 11 ′ directed onto the paper web 110 upstream of the size press 9 . Furthermore, a third spectrometer 10 ″ is arranged with its measuring area 11 ″ downstream of the size press 9 , the measuring are 11 ″ may be directed onto the sized paper before the adjacent wind-up device, which is not shown in detail.
In FIG. 2 a a three-layer neural network in designated by 20 , and, for example, comprises input neurons EN 1 to EN 7 and further neurons ZN 1 to ZN 5 and an associated output neuron AN 1 . Using the neural network 20 , the spectrum from the first spectrometer 10 is evaluated. The backscatter intensities I 1 to I n from preferred wavelengths λ i of the schematic diagram in FIG. 2 b are used as inputs for the neural network 20 . Statements about the quality of the paper to be produced may be obtained from the wavelength intensities I i with i=1, . . . , n. The statements of the paper quality of output AN 1 can be used, on the one hand, for the feedback control in the stock preparation and, on the other hand, for feedforward control in the paper machine 1 itself.
Shown in FIG. 3 is another three-layer neural network 30 , which has input neurons EN 8 to EN 12 and further neurons ZN 6 to ZN 9 and an output neuron AN 2 . Using this second neural network 30 , data from the spectrometers 10 ′ and 10 ″ are evaluated in a similar manner to that in FIG. 2 a. It is also advisable to use the moisture 31 of the paper web 110 as a measured variable as a further input variable. Hence, statements about the product quality of the finished paper or board may be obtained on output AN 2 . Furthermore, mechanical parameters, such as the so-called CMT factor, the breaking length, and the burst pressure, can also be obtained.
It is also possible to provide, for the two further spectrometers 10 ′ and 10 ″, one dedicated partial neural network each. The neural networks according to FIGS. 2 and 3 can also be combined, the reliability of the derivation of the measured variables being improved by their interlinking.
Alternative possibilities for use of spectrometers in the context of paper and board production are set forth in FIGS. 4 to 7 . For each of FIGS. 4 to 7 there is a unit 50 for stock preparation, a so-called central stock area 70 , a paper machine 100 , which corresponds to the paper machine 1 according to FIG. 1, and a neural network 200 , which is assigned to the paper machine 100 and corresponds to the neural network 20 of FIG. 2 a. The units 50 , 70 , 100 and 200 are integrated into a functional loop.
In FIG. 4 the spectrometer 10 according to FIG. 1 is assigned to the unit 50 for stock preparation. There, it is possible, for example, to register pulp or different waste paper materials, which is indicated by means of the parallel arrows. Via the central stock area 70 , suitable output material passes to the paper machine 100 . In addition to the signals from the spectrometer, the machine parameters and actuating variables and the data about the required paper quality are fed to the neural network 200 . Following off-line training via laboratory measurements on finished paper, the required mixing parameters and actuating variables for the output stock are given to the central stock area 70 using the neural network 200 .
In FIG. 5, the measurement using the spectrometer 10 takes place at the stock inlet for the paper machine 100 , that is to say downstream of the central stock area 70 . With a construction of the neural network 200 which is in principle identical, the result here is the possibility of generating actuating signals, such as actuating variables and parameters for the stock preparation 50 , on the one hand, and actuating variables for the paper machine 100 , on the other hand.
In the case of the arrangement according to FIG. 6, the spectrometer 10 is used on the finished paper or board emergent within the paper machine 100 . In accordance with FIG. 6, using the neural network, it is likewise possible to obtain actuating variables for the paper machine 100 , as well as actuating signals for the stock preparation 50 or the central stock area 70 .
In the case of the alternatives shown in FIGS. 4 to 6 , the neural network 200 is in each case directly assigned to the paper machine 100 , the required mechanical paper quality data being predetermined as important characteristic variables. In FIG. 7, an example is specified which specifically relates to the stock preparation 50 , that is to say the unit 50 of FIGS. 4 to 6 . In addition to the unit 50 for the stock preparation, having known individual elements, such as a so-called pulper, a refiner or the like, there is here, moreover, a stock pulping unit 55 . The stock pulping unit 55 essentially prepares waste paper and mixes it in specific proportions with a suitable pulp suspension.
In FIG. 7 the unit 50 for the stock preparation is assigned a neural network 220 , to which the required fibre qualities are input as characteristic variables. Using the spectrometer 10 , in this case measurements are made on the pulped stock before the actual stock preparation 50 , and the measured intensity signals are entered into the neural network 220 . Following suitable training of the neural network 220 , suitable actuating signals for the stock preparation 50 may be obtained using the measured values.
In the individual examples, it was shown that as a result of on-line measurement using one or more spectrometers and evaluation using one or more neural networks, as well as determination of the quality values of the paper or board to be produced, the quality determining parameters of the stock preparation and of the paper machine can be influenced on-line. In contrast to previous approaches utilizing discontinuous methods using laboratory measurements, the present invention avoids delay times. | A method and apparatus for using a neural network to control a paper or paper board production machine. By using spectrum measuring devices, the characteristics of the starting materials for the paper and board production and/or their intermediate or final products are registered and the values fed to a neural network. The network provides statements concerning the paper and board quality, from which signals for the feedback and/or feedforward control of the production process may be derived. | 3 |
The present invention generally relates to a calibration tool for setting a reciprocating blade on an electric trimmer and more particularly, relates to a calibration tool for setting the reciprocating blade on an electric trimmer to a pre-determined clearance such that the blade does not cut or bite the skin of a customer when used by a barber or a hair stylist.
BACKGROUND OF THE INVENTION
Electric hair trimmers have been widely used in trimming hair by barbers and hair stylists. The hair trimmer is normally constructed of a stationary blade that has a substantially straight role of cutting teeth, and a reciprocating blade that has a roll of cutting teeth that is complimentary to the roll of teeth on the stationary blade. When hair enters into a space between the adjacent teeth of the stationary blade, a tooth on the reciprocating blade passes across the space and thereby engaging and shearing the hair. The electric hair trimmers are capable of trimming hair to a very small distance from the skin or scalp of a person.
An electric hair trimmer, after repeated use, must be cleaned, sharpened and recalibrated such that the trimmer can cut hair effectively, without cutting or biting the skin of the person. When the reciprocating blade is removed from the trimmer for cleaning or sharpening, it is usually reassembled into the trimmer on a trial and error basis. There are no tools currently available in calibrating the position of the reciprocating blade relative to the stationary blade in the trimmer. It is therefore a time consuming and laborious process for remounting a reciprocating blade into a trimmer.
It is therefore an object of the present invention to provide a blade setting tool for mounting a reciprocating blade into an electric hair trimmer.
It is another object of the present to provide a blade setting tool that can be used to effectively calibrate the position of the reciprocating blade relative to the stationary blade.
It is still another object of the present invention to provide a blade setting tool that enables the mounting of a reciprocating blade into an electric trimmer with minimum calibration effort.
It is still another further object of the present invention to provide a blade setting tool that is capable of calibrating a reciprocating blade when it is mounted into an electric hair trimmer such that the trimmer does not cut or bite the skin of a person.
SUMMARY OF THE INVENTION
In accordance with the present invention, a blade setting tool for calibrating the position of a reciprocating blade relative to a stationary blade in an electric hair trimmer is provided. The blade setting tool can be advantageously used in the remounting of the reciprocating blade after the blade has been cleaned or sharpened.
In a preferred embodiment, a blade setting tool is constructed by an elongated base plate that has two opposing end walls formed integrally with and projecting upwardly from a top surface of the elongated base plate; a calibration blade that has a first plurality of teeth fixedly mounted to an inside surface of a first end wall, the first plurality of teeth is parallel to the top surface of the elongated base plate; a compression plate slideably mounted juxtaposed to an inside surface of a second end wall facing the first end wall; a compression means for compressing the compression plate towards the first end wall when a reciprocating blade/stationary blade assembly is mounted in between the compression plate and the first end wall; and at least two apertures in the elongated base plate for mounting by screws the reciprocating blade to a trimmer after a second plurality of teeth on the reciprocating blade intimately engages and mashes the first plurality of teeth on the calibration plate.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is a perspective view of the blade setting tool and a reciprocating blade/stationary blade assembly to be calibrated.
FIG. 2 is a perspective view of the present invention blade setting tool with the reciprocating blade/stationary blade assembly mounted therein.
FIG. 3 is a partial, cross-sectional view illustrating the compression plate and the compression means of the present invention blade setting tool.
FIG. 4 is a cross sectional view of the present invention blade setting tool with a trimmer shown in ghost lines.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention discloses a blade setting tool for use in calibrating the position of a reciprocating blade used in an electric trimmer after the blade has been removed for cleaning or sharpening. The blade-setting tool can be used efficiently to calibrate the position and mounting of the reciprocating blade relative to the stationary blade such that when the trimmer is used, no cutting or biting of the skin of the person receiving a hair cut can occur.
The present invention blade setting tool is a device that enables the setting of hair trimmer blades to the appropriate position to avoid cuts and biting of the skin of a customer. The device can be advantageously used in professional barber shops and beauty salons. The blade setting tool enables one to position blades in such a manner as to allow a more accurate method of trimming a customer's hair. The blade setting tool includes a bottom plate that would slide underneath the teeth of the calibration blade, which is mounted at one end of the tool. Screws are then used to secure the position of the reciprocating blade in the hair trimmer. The reciprocating blade, sometimes called the liner blade, must be accurately mounted in the electric trimmer in order for the trimmer to work satisfactorily without the cutting or biting problems. The present invention blade setting tool enables one to efficiently set the reciprocating blade with a clearance between about 0.024 and about 0.025 inches from the tip of the stationary blade and thus avoiding problems in the function of the trimmer.
Referring initially to FIG. 1 , wherein a present invention blade setting tool 10 is shown in a perspective view. A reciprocating blade/stationary blade assembly 20 is also shown in FIG. 1 for mounting into the setting tool 10 .
The blade setting tool 10 is constructed by a base plate 12 that has two opposing end walls 14 , 16 projecting upwardly from a top surface 18 of the elongated base plate 12 .
The two opposing end walls 14 , 16 may be formed integrally with the elongated base plate 12 , or may be assembled to the elongated base plate 12 by mechanical means, such as by screws (not shown). On the first end wall 14 is mounted a calibration blade 22 that has a first plurality of teeth 24 fixedly mounted to the inside surface 26 of the first end wall 14 . The first plurality of teeth 24 is mounted parallel to the top surface 18 of the elongated base plate 12 as shown in FIG. 1 .
The present invention blade setting tool 10 further includes a compression plate 28 which is slidably mounted juxtapose to end spaced apart from the inside surface 30 of the second end wall 16 facing the first end wall 14 . The compression plate 28 is compressed toward the first end wall 14 by a compression means 32 , such as a threaded bolt, as shown in FIG. 1 . The threaded bolt 32 engages a threaded hole 34 in the second end wall 16 and thus pushing on the compression plate 28 and the reciprocating blade/stationary blade assembly 20 when it is mounted on the elongated base plate 12 . It should be noted that the reciprocating blade/stationary blade assembly 20 has a reciprocating blade 36 and a stationary blade 38 . Two mounting aperatures 40 which are threaded are further provided in the end of the stationary blade 38 for mounting into an electric trimmer (not shown).
FIG. 2 is a perspective view of the present invention blade setting tool 10 with the reciprocating blade/stationary blade 20 mounted therein. It should be noted that the first plurality of teeth 24 on the calibration blade 22 intimately engages and mashes with the second plurality of teeth 42 on the reciprocating blade 36 , while the third plurality of teeth 44 on the stationary blade 38 is inserted under the first plurality of teeth 24 of the calibration blade 22 , as shown in FIG. 2 . The position of the reciprocating blade 36 is thus fixed by the intimate engagement and then, two screws are used to mount the reciprocating blade to a reciprocating linkage (not shown) in the electric trimmer 50 . This is shown in FIG. 4 . The mounting of the reciprocating blade 36 is achieved through two mounting holes 46 provided in the reciprocating blade 36 . This is made possible by inserting two mounting screws 48 through two apertures 52 in the elongated base plate 12 .
A detailed view of the compression plate 26 in relation to the second end wall 16 and the compression means 32 is shown in FIG. 3 in a cross-sectional view.
While the preferred embodiment of the invention have been described above, it will be recognized and understood that various modifications can be made in the invention and the appended claims are intended to cover all such modifications which may fall within the spirit and scope of the invention. | A blade setting tool for calibrating the mounting position of a reciprocating blade in an electric trimmer after the blade has been removed for cleaning or sharpening. The blade setting tool provides a time-saving and convenient method for mounting of the reciprocating blade such that a pre-determined clearance is maintained between the reciprocating blade and the stationary blade to avoid cutting or biting problems during a hair cut. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a non-provisional application claiming the benefit of U.S. Provisional Patent Application No. 60/211,775 filed Jun. 15, 2000, entitled “Electronic Mail (E-Mail)/Internet Appliance,” which is hereby incorporated by reference.
NOTICE OF COPYRIGHT PROTECTION
A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the United States Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
FIELD OF THE INVENTION
This invention relates generally to electronic mail methods and systems. More particularly, the present invention relates to electronic mail Internet appliance methods and systems.
BACKGROUND
Electronic mail (Email) is fast becoming as integral a part of life as the telephone. Like telephone access, email access is available to many in the home as well as in the workplace. Additionally, public places, such as libraries and coffee houses, now provide email access. One appeal of electronic mail is that it provides a capability to keep in touch with long distance friends and relatives without incurring long-distance charges. Another advantage is that electronic mail provides an interface mechanism for collecting information from Internet services.
However, conventional email systems require the user to own or access a computer with Internet access. Not everyone owns a computer or wants to leave their home merely to read or send electronic mail. Additionally, not every one has access to the Internet or wants to pay a monthly fee for such access.
Another requirement of many conventional email systems is that one access an email account via the telephone network, thus tying up a phone line. One can normally install a second phone line or acquire an alternative Internet access mechanism, such as Digital Subscriber Line (DSL) or cable. However, these solutions are often expensive.
Certain conventional systems (e.g., the Landel Telecom MailBug™ system) implement an email device that plugs into a household phone jack in serial with a telephone. A user of such a conventional system, therefore, does not need a personal computer to access email.
Although a user of conventional systems plugs the device into a household phone jack, email reading and manipulation is performed “offline.” In other words, using such a conventional system does not tie up a phone line for longer than the time required to download or upload email from a mail server. Thus additional phone lines or alternate Internet access mechanisms are not necessary for the system user to access email.
Conventional systems, however, have some shortcomings. First of all, the display provided in such conventional systems is unnecessarily cluttered. Additionally, in order to perform certain functions using such conventional systems, a user is required to execute unnecessary steps.
The following patents discuss various aspects of telephony useful for background information and are incorporated herein by reference: Telephone Set, U.S. Pat. No. D410,005; Telephone Set, U.S. Pat. No. D405,447; Method And Structure For Detecting A Customer Premises Equipment Alerting Signal, U.S. Pat. No. 5,862,212; Caller Id Telephone With Signal Attenuation, U.S. Pat. No. 5,836,009; Telephone Set, U.S. Pat. No. D397,112; Text Transmission Using DTMF Signalling, U.S. Pat. No. 5,699,417; Caller Id And Call Waiting For Multiple CPEs On A Single Telephone Line, U.S. Pat. No. 5,583,924; and Caller Id And Call Waiting For Multiple CPEs On A Single Telephone Line, U.S. Pat. No. 5,574,777.
What is needed is a method and system for providing personal computer-free email access that avoids the disadvantages of conventional systems, while offering additional advantages.
SUMMARY
Embodiments of the present invention provide methods and systems for an email Internet appliance. Implementations of the present invention comprise a method, a process, a system, an apparatus, a computer readable medium, and a data stream.
Embodiments of the present invention provide mechanisms for manipulating email messages without the necessity for a personal computer. Manipulating email messages comprises inserting an email message into a classification container associated with a classification display section, segmenting a user interface into classification display sections, displaying a classification container in each classification display section, deleting an email message, sending an email message, and scrolling a page of email messages at a time.
Alternative embodiments of the present invention provide streamlined mechanisms for manipulating email messages by deleting. An example of one such mechanism comprises an invoking of a Delete-All option to quickly and efficiently delete all email messages without requiring a user to select an email message before all messages can be deleted. Another example comprises a mechanism allowing a user to invoke a Select-All option before invoking a Delete option to subsequently delete all messages. Such a mechanism permits a user to select all of the messages as a group, rather than individually, in order to efficiently delete all email messages.
Another embodiment provides a streamlined mechanism for manipulating email messages by sending saved messages. An example of such a mechanism comprises selecting a saved message, and then invoking a Send option. In yet another embodiment, a user is prompted as to whether the user wants to save an email message that has been sent. This prompting feature may be enabled/disabled at the option of a user via a setting in a configuration file that can be dynamically modified via a properties or options interface in alternative embodiments.
Additionally, embodiments of the present invention provide streamlined mechanisms for manipulating email messages by scrolling one page at a time. One example of such a mechanism comprises double clicking on a scroll bar and then selecting either an up arrow key or a down arrow key. Another example comprises a mechanism in which a user invokes a softkey (or a programmable function key).
An embodiment of the present invention provides a streamlined capability to select items in a network service. An example implementation of this capability comprises creating a short cut to an information item in a network service, and then invoking the short cut. In one embodiment, the network service comprises a news service. An exemplary news service is the LYCOS News Service.
An embodiment of the present invention provides a streamlined capability for updating (and creating) a phone book. Such a capability comprises the steps of receiving a data collection, which has phone data comprising a name and a number associated with the name, extracting the phone data from the data collection, determining whether the phone data is unique, and, if the phone data is unique, then adding the phone data to the phone book. Such an embodiment provides an advantage over conventional systems in that some conventional systems require a user to manually add phone data to each of a generic data collection, such as an address book, and a phone book.
An embodiment of the present invention provides a scrollable display for allowing a user to view at least six, but no more than fifteen, lines at a time. Such a screen is large enough for efficient viewing of messages, but small enough to keep the cost of the device to a minimum. And, in alternate embodiments, input is available via keyboard, and output is accomplished through an RJ-11 interface to a public switched network. Such input and output mechanisms provide a user with capabilities similar to personal computers, but without the added cost.
Embodiments of the present invention provide several advantages over conventional systems. First of all, a user of one embodiment of the present invention can access email accounts without having to use, or purchase, a personal computer. Secondly, a user of an embodiment need not tie up a phone line while reading email messages. Other embodiments provide streamlined methods for manipulating email messages, including but not limited to, the deleting of messages, the sending of messages and the page scrolling of messages. Additional improvements permit users to create or modify a phone book from a data collection, such as an address book. Another advantage for users of an embodiment is the capability to directly access desired information items within a network service.
Additional objects, advantages, and novel features of the invention will be set forth in part in the description which follows, and in part will become more apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 comprises an exemplary hardware embodiment of the present invention.
FIG. 2 comprises an embodiment of the present invention illustrating interconnection with a Public Switched Telephone Network.
DETAILED DESCRIPTION
One embodiment of the present invention comprises an electronic mail (email) Internet appliance that provides email service and information service via a telephone line connection. Advantageously, a user does not have to use a computer or similar device to communicate via email or to access information services. The user may use the email device for email communication and for accessing information services.
In an embodiment, the email device is of a compact, low profile design that includes a keyboard and a display. The device advantageously is relatively small (in an exemplary embodiment—approximately 10.6″ long×7″ deep×2.75″ high) and light (in an exemplary embodiment—approximately 1.75 lbs including the battery). As a result of its relative smallness and lightness, the email device is portable. The device connects to a standard, analog telephone line, supports dual tone multi-frequency (DTMF) or touch-tone dialing, and requires an AC power source. Thus, the device may be easily disconnected from a first location such as at the user's home, transported with the user, and set up at another location such as a hotel room of the user.
As noted, in addition to the display, the email device includes a keyboard for composing messages and implementing other functions. The keys of the keyboard are full-sized as those used in a keyboard of a word processor or such similar equipment. The email device may include buttons or other non-standard keyboard keys for use in composing email messages and executing other functions in connection with email or the information service. For example, the email device may include send, reply, forward, delete, etc. buttons. As another example, softkeys may be included to make selections from displayed lists easier. Advantageously, the buttons and softkeys or function keys are spaced on the email device such that they are easy to use.
The device also includes a display for presenting email messages and information that are received, email messages that are composed by a user of the device, and instructions, advice and other text information. An exemplary email device includes an eight-line screen display that is large enough to allow the user to see complete lines (seventy-nine characters in an exemplary embodiment) of text. The display may be configured in a number of different ways. For example, the top line of the display may include information that provides current status of the device. This current status information may include a time and date indication and the device may make automatic adjustments for the implementation of daylight savings time. The center six lines of the display may be used for a list of email messages, for display of information, for instructions to a user, etc. The bottom line of the display may include information such as display labels for the function keys of the device. Further, the display may include fluorescent backlighting to provide excellent readability. In addition, the display may include scrolls (up/down, side-to-side, right/left) to enable the user to change the text being displayed. The user can further modify the contrast and brightness of the display.
Generally, an exemplary embodiment of the email device, according to the present invention, includes the following components: the device; a 12 volt ac-dc adapter; a 9 volt battery; a 6-foot telephone line cord, guide or manual, and a summary of operation.
The device may share a telephone line with a telephone or other equipment such as an answering machine, but the device does not interrupt or otherwise affect conventional telephone service on the telephone line. A second line for the email device is unnecessary. When sharing the line, the email device senses when the line is in use and places a call to send or retrieve email only when the line is not being otherwise used. All reading and composing of messages is done while the email device is off-line, and therefore, the activities of reading and composing email do not tie up the telephone line.
In an embodiment, the email device provides a single mailbox (single email address) for email messages, but any number of people may share the mailbox. The largest email message that may be received on the email device is a message of 16,000 characters, which is about four pages of typed text. Any characters in excess of this number are deleted. The original email message in undeleted form may be made available on a web-mailbox to which the user may have access.
When an email message or other information is received, a slow blinking light on the device may be set to indicate that a message or other information has been received. The slow blinking light, a different light, or a different indicator may be used in the email device to provide an indication to the user of the following: an unread email message; a new voicemail (such as on an answering machine on the line), a new call to the line; a line-in-use status. The light may be “on” continuously when the telephone or other connected equipment is in use on the telephone line. When a call is being received, then the blinking light may blink more quickly.
A problem with the blinking light or other indicator being used with the receipt of new voicemail messages is that it is difficult for a user to determine whether new calls, new email messages, or voice mails have been received. The difficulty stems from the fact that a call may be received to the caller's line, but then the caller hangs up leaving no message. Even though no message has been left, the light blinks to indicate that a call had been received. The blinking light frustrates a user who checks the email device to find that in fact, no new message (email or voice mail) has been received. Thus, an exemplary embodiment provides that no light or other indicator blink or otherwise operate to indicate the receipt of a new call. In this way, the light blinks at least to indicate the receipt of a new email, so that when the user checks for messages, at least a new email message is present.
In alternate embodiments, the email device may be set for either manual or automatic email checking. In automatic checking, the email device checks for new email for the user on a variable basis. If the email device is frequently used, then the email device may check for new emails more often than if the device is less frequently used. The device in automatic checking mode generally checks at least once per day, and may check every few hours. A manual check for new messages may be initiated at any time by the user, even if the email device is in the automatic mode. In an exemplary embodiment, this manual check may be carried out while in the automatic mode by pressing the CONNECT key or the CTRL key of the device.
To view an email message on the display of the email device, the user may be required to provide a password. In other words, password protection may be incorporated as a feature of the email device.
The email messages that are received by an email device may be stored, may be accessed, and may be managed. For example, the email device allows for storage of up to 100 messages with a total capacity of up to 120K characters.
In an exemplary embodiment, the email device displays all messages (whether received, sent, or outgoing) in the same display. In other words, when a user selects email on the email device, the user is presented with a list of all emails regardless of whether the emails were received, sent, or “to-be” sent. Because the display only allows for six email messages to be shown at any one time, it quickly becomes cumbersome to navigate through a large list of email messages. The email device has a limited memory capacity, and thus, the “all email” display feature may have been implemented as a way to save memory.
Another exemplary embodiment of the email device includes a feature whereby “sent messages” are separated from the other email messages, and the sent messages may be displayed in their own section in the display of the email device. Yet another exemplary embodiment of the email device further reduces the possibility of clutter on the display of email messages by giving the user the choice of saving and/or of deleting an email message that has been sent. This choice may be presented to the user after the user strikes the key that sends the email message. If the user chooses the “not save” or to “delete” the sent email message, then the sent email message does not appear on the display.
In some embodiments of the email device, a user who has saved an email message, and who now desires to send the saved email message must first open the email message and then press a function button labeled “change” before the user is given the option to “send” the saved email message. An alternative embodiment of the email device allows a user to “send” the saved email message without first having to press the “change” button.
Also, in some embodiments of the email device, when a user connects the email device to the server and the server is transmitting email messages to the email device, the display of the device bears the message: “Forwarding your mail”. Because the term “forwarding” may be ambiguous and confused with functions of email forwarding to others, an alternate embodiment substitutes the message: “Sending your mail.”
To scroll through the email messages, the user may use up or down arrows. But to scroll up or down a page at a time, it is necessary in some embodiments for the user to hold down the CNTRL key while pressing the up or down arrows to accomplish the scrolling. This is a disadvantage because a user may not intuitively or otherwise know to hold down the CNTRL key to obtain page scrolling. Thus, alternative embodiments of the email device provide that a user not have to hold down the CNTRL key while using the up or down arrows to accomplish the page scrolling. Instead of the CNTRL key, some other key, such as a shift key or a softkey, may be pressed (but not necessarily held down), or a double click on the scroll bar prior to using the up or down arrows may accomplish the page scrolling.
In an exemplary embodiment, a diamond shape or symbol is used in various ways in the email device. For example, the email device distinguishes between read and unread mail on the display through the use of a diamond shape or symbol. The same diamond symbol is used to identify mail that is to be sent, but has not yet been delivered. The diamond symbol also is used to identify the most frequently used function keys. Given that repetitive use of the diamond symbol may cause possible confusion, an alternative embodiment does not repeat the use of a diamond symbol or shape. In other words, the diamond symbol or shape is used at most for one feature or function. Other symbols or shapes are used in place of the other diamond shapes previously used.
In another embodiment, an email device includes storage (non-volatile electronic memory) for one or more address books that may be used by the caller in connection with email messaging. For example, an email address book of the device may store up to 100 addresses. The device also may include a telephone book for the storage of frequently used telephone numbers, and the telephone book may store up to 100 telephone numbers. In some embodiments, the address book for email addresses and the telephone book for telephone numbers do not compliment one another. In other words, a user has to separately enter information about an addressee in the email address book, and then enter information about the addressee in the telephone book. In an alternative embodiment, where the information for the addressee is the same between the email address book and the telephone book, the information is entered into one of the two books then copied into the second book.
The email device further includes a feature that allows a user to use the device to check an email message box associated with another email account, so long as the service provider supports the appropriate standards for such a feature. For example, an exemplary embodiment of the email device uses the POP3 protocol.
An embodiment of an email device, according to the present invention, may be used to send an email to anyone with an Internet email address. A person does not have to have an email device to receive emails from a user of the email device. The user of the email device may send an email message to more than one person (or email address).
In an exemplary embodiment, the email device may be used in a manual mode to compose and send email messages. When a user is done composing an email, the user indicates the message is ready to be sent by pressing a function button labeled “send”. Pressing the “send” button does not actually send the email, it only saves the composed email message in ready-to-send form. If a user wants to send the message (while in manual mode), the user must press the function key labeled “done” to get out of the email menu. When the user has reached the top level of the of the email menu, then the user must press the “connect button”. A disadvantage of this exemplary embodiment in the manual mode is that some users may mistakenly believe that they have sent an email message after they have pressed the “send” button. Thus, because of this possibility of confusion, another exemplary embodiment of the email device provides that the manual mode not be used—at least for composing and sending email messages.
Advantageously, the email device places a local call or an 800 number call to send and retrieve email message. Thus, there are no long distance or other toll charges in connection with the use of the device for email.
The email device also includes a calling number identification (CallerID) feature so that a user does not have to have a separate CallerID box to identify incoming calls. The CallerID feature may provide the name, number, time, and date of a call that has been received on the telephone line. The CallerID feature may include a CallerID log to save up to ninety-seven call records. A telephone number that is included in an entry in the CallerID log may be auto-dialed through the use of a telephone book Caller ID log. When the telephone number of an incoming call matches a number in the email devices' telephone book, then a name is displayed indicating the name of the person or entity calling.
As previously noted, the email device may be used to obtain information through a Web service. In an exemplary embodiment, a user may press the “e-Info” key of the email device or a soft key to display Web service information. For example, the following types of information may be obtained: top news, sports news, world news, entertainment news, health news, stock quotes, sports scores, daily horoscopes, and local weather forecasts. The email device does not include a browser, so the email device is unable to be used to browse the Web.
In an exemplary embodiment, once a user chooses “e-Info” and a connection is made to the server, the user is presented with two choices: LYCOS News Service; or More to Come. The More to Come option is not really an option in this embodiment because nothing has been implemented. Therefore, an alternative embodiment does not present the user with those two choices. Rather, when only the LYCOS news Service (or any other service) is only available, then the email device goes directly to the only available option.
Another exemplary embodiment allows a user of the e-Info feature to create shortcuts to speed the selection of information items. For example, the user may identify a city to be used in connection with the provision of weather information, or may identify particular stocks for use in providing the user with stock information. Yet another exemplary embodiment includes a shortcut for the user in the use of the “return” key to enter information into the e-Info section or feature. For example, in this yet another exemplary embodiment, the user may select “weather” as information desired and may be prompted to enter the initials of the State for the weather information. Rather than having to press or implement some other function like an OK function after the state initials have been entered, this yet another exemplary embodiment allows the user to simply press the “return” key after the initials of the State have been entered. In some instances in the yet another exemplary embodiment, the “return” key may be pressed in place of the “OK” or other key in other embodiments to signal the continuation of a function. Advantageously, the “return” key is typically easier to press and steps of the process may be eliminated by the use of the “return” key instead of the “OK” key.
The email device is provided with the email service through a service provider that bills the user for the service provided. The service provider typically operates a service platform in a data network such as the Internet to provide email services to each of the email devices that are served by the service provider.
The email device may provide for email with attachments that are text or HTML, or other file types that can be converted into text. Other types of attachments (graphics, spreadsheets, pictures, etc.) cannot be viewed on the email device, and are deleted from any email message including such an attachment at the server. Advantageously, a service provider may provide a computer user with a web-mailbox account so that the user may access email messages that have been sent with attachments. Another advantage is that the web-mailbox account may include a duplication of the emails that the user received on the email device (but with attachments where they are included with emails).
In an embodiment, the email device does not include a printer. To print an email, the user may forward the email to a location that does include a printer and print the email from that forwarded location. In addition, a user may use a computer (connected to the Internet) with a printer to access the web-mailbox account so that the email message is accessed and printed.
Additional information from a human factors analysis is discussed in the ensuing paragraphs.
Exemplary embodiments of the email device include a manual. An alternative exemplary embodiment provides a 1-2 page help guide as a summary of the manual. Such a help guide may be used by beginners, who would be intimidated by a manual, and by experienced people, who desire to jump right in to operation of the device rather than read a manual.
An exemplary embodiment of the email device provides the device in “automatic” mode as the default mode. In automatic mode, the email device periodically sends or receives email messages without user intervention. This is a useful feature because in some embodiments of the email device, it has not been clear when a message has been “sent”. For example, in some embodiments of the email device, when a user has finished composing a message, the user indicates that the message is ready to be sent by processing a function button labeled “send”. In manual mode, this button does not actually insure that the mail will be sent. If a manual mode user wishes to transmit an email, that user must first press “send”, then press “done” to get out of email mode. Finally that user must push the “connect” button to actually transmit the mail. It is likely that some users (while in manual mode) will wrongfully assume that mail has been sent the “send” function button has been pressed. Such users would be frustrated. Thus, an exemplary embodiment provides for an automatic mode to be used as the default operating mode rather than a manual mode.
Additional objects, advantages, and novel features of the invention will be set forth in part in the description which follows, and in part will become more apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention.
EXAMPLE
FIG. 1 and FIG. 2 show an example of an embodiment of the present invention. FIG. 1 illustrates an embodiment of an Email Internet Appliance 100 . An Email Internet Appliance 100 comprises a standard full size QWERTY keyboard 50 for input and a display 20 for presenting output to a user. Other types of keyboards may be utilized in alternative embodiments.
Display 20 comprises a message/text display area 25 , which displays six lines of text, in one embodiment, a line below the message/text display area 28 for display labels 28 which label function keys 29 , and a status information line 27 , which presents the current status of the Email Internet Appliance 100 and is located above the message/text display area 25 . Examples of current status information that may be provided to a user include mode of operation (automatic or manual) and date/time. Other display types may be used in alternative embodiments, providing a display of up to fifteen lines of message/text.
Located below label function keys 28 are function keys 29 . Function keys 29 are keys programmed to implement certain functions, such as “Change”, “Delete-All” and “Forward”. Buttons 30 are located to the side of the message/text display area 25 and invoked by a user to surface screen menus. Scrolling keys 35 (for scrolling up) and 36 (for scrolling down) are provided for navigating through large numbers of email messages.
A status indicator light 40 , in one embodiment, employs a blinking frequency to indicate Email Internet Appliance 100 status. For example, a fast blink may indicate that an email has been received, a slow blink may indicate a voicemail message has been received, and a status indicator light 40 that is constantly on may indicate that the phone is in use.
The Email Internet Appliance 100 provides a user with electronic mail (or email) access without the need for a computer. In one embodiment, a user plugs a household telephone into the Email Internet Appliance 100 , which then attaches to the phone system.
FIG. 2 comprises an illustration of an embodiment in which the present invention is interfaced to a conventional telephone system. A telephone 110 is connected to an email Internet appliance 100 using an RJ-11 interface. Email Internet Appliance 100 is then plugged into a telephone system interface, such as a RJ-11 phone jack 150 .
An RJ-11 phone jack 150 provides network access from an email user's house to the Public Switched Telephone Network 120 . The Public Switched Telephone Network 120 provides a communications path to a Data Network 130 , implemented by an Internet Service Provider, in one embodiment. Data Network 130 comprises, among other network elements, a mail server 140 . Examples of a Data Network 130 include, but are not limited to, an internet and an intranet.
An email user of an Email Internet Appliance 100 accesses the user's email by establishing a connection to a mail server 140 . Once the connection is established, Email Internet Appliance 100 and mail server 140 exchange information using the Internet Post Office Protocol, POP3, in one embodiment. The exchange of information may include, for example, the downloading of received email messages from the mail server 140 to the Email Internet Appliance 100 or the uploading of sent email messages from the Email Internet Appliance 100 to the mail server 140 .
A user conducts an email session with at least one mail server. The user displays email messages in the email message text area 20 of an email appliance 10 . In one embodiment, email messages are stored in classification containers. Examples of classification containers include vectors, lists, text fields and windows. Each container represents a different message category, based upon a type or classification of the email message. Email message categories comprise new, sent, read, marked for deletion, and saved message types. Classification containers will store at least one email message type. The scrollable email message text area 20 displays a concatenation of these categories of email messages. Each message category may be displayed in a clearly marked segment (for example, a listing of all email messages of a particular type preceded by a descriptive header) or all categories may be merely listed one after the other, but with email messages grouped according to message type. A classification container will be displayed in each display section or segment.
Alternatively, a user may be given a choice of which email message types the user would like to see displayed in the scrollable email message text area 20 . Based upon the user's selection (or classification display section request), a concatenation of the sections representing the selected email types appears in scrollable email message text area 20 . A classification container will be displayed in each section or segment.
In alternate embodiments, a user conducts an email session by first accessing at least one mail server. The user then downloads and/or uploads mail messages from/to the server. Mail messages, including those received and those sent but saved, are stored in a database in one embodiment. Additionally, an email session may be conducted according to the Internet Post Office Protocol POP3.
A user of the present invention can manipulate email messages in the manners previously discussed. In one embodiment, deleting an email message, including the simultaneous deleting of multiple messages, is streamlined. All email messages may be quickly deleted by invoking a “Delete-All” option. In alternate embodiments, a Delete-All option may be implemented as a softkey or as a menu option, which is made visible by hitting a “control” key. When selected, the Delete-All option removes all email messages from all classification containers.
In another embodiment of the present invention, a user first chooses a “Select-All” option, and then invokes a “Delete” option to quickly and efficiently delete all email messages, by removing all messages from all classification containers. In alternate embodiments, a Select-All and a Delete option may be implemented as softkeys or as menu options, which are made visible by hitting a “Control” key.
Additionally, in order to quickly and efficiently delete multiple email messages, but not necessarily all messages, a user of an embodiment of the present invention first selects (e.g., highlights) at least two messages and then invokes a “Delete” option, resulting in the removal of all messages from all classification containers. As discussed above, a Delete option may be implemented as a softkey or as a menu option, which is made visible by hitting a “Control” key.
Another typical way a user manipulates email messages in the present invention is to send a message. One embodiment streamlines the sending process by allowing the user to first select at least one saved message, and then invoke a “Send” option. This results in the selected messages being “sent” or transferred from the appropriate classification container(s) on the present invention to a mail server implementing the POP3 protocol, in one embodiment.
In an alternate embodiment, a user is prompted each time the user sends an email message. The user is queried by a prompter in communication with the Display 20 as to whether the user desires to save a copy of the sent mail message. This prompting feature may be enabled/disabled at the option of a user via a setting in a configuration file that can be dynamically modified via a properties or options interface in alternative embodiments.
An additional manner of manipulating email messages in the present invention is to scroll messages up or down one page at a time. One embodiment streamlines the page scrolling process by allowing the user to first double click on a scroll bar, and then to press an up arrow or a down arrow to cause the display of email messages to scroll up or down, respectively, one page at a time. In an alternative embodiment, a user selects a softkey (or a programmable function key) to scroll up or down one page at a time, depending upon the function that is represented by the softkey.
With the present invention, a user is in communication with a computer network, such as an internet, and is able to connect in a more streamlined manner in order to communicate with network services. In an embodiment, the user can establish (i.e., create new or modify existing) configuration files and save configuration files that are associated with network services. As a first step in connecting to a network service, the user selects a desired network service, such as the LYCOS News Service, from a menu that is made visible by depressing a softkey or function key, in one embodiment. The present invention then connects to the network service through the Public Switched Telephone Network (PSTN) to a server or an Internet Service Provider (ISP), in alternative embodiments. The present invention forwards the network service address, which corresponds to the user's selection, and the previously established configuration file. The network service address directs the server, in one embodiment, to the network service with which to connect. The configuration file directs the network service to present the user's desired interface (or configuration).
In another embodiment, a user of the present invention creates a short cut to an invention item in a network service. A user then invokes the short cut to go directly to the area of the network service to which the short cut refers.
Once the user connects and the network service automatically configures, the user may then conduct an interface session with the selected network service. An interface session with a network service, including a news service such as the LYCOS News Service, comprises user activities such as browsing through email messages of current events and engaging in chat sessions.
An embodiment of the present invention also provides a mechanism to create or modify (i.e., update) a phone book from other data collections, such as an address book. A user selects an option to create or modify a phone book from a data collection, such as an address book. The user provides the name of a data collection, and the present invention receives that data collection and extracts phone data, comprising a name and an associated phone number, from the data collection. If a phone book does not exist, the present invention creates a new phone book from this extracted data. Or, the present invention compares the name and number pairs of the extracted phone data to the name and number pairs in the existing phone book, and adds those pairs that are unique (i.e., do not appear in the existing phone book) to the existing phone book.
It should be noted that the present invention may also be embodied as computer readable code on computer readable medium. The computer readable medium is any data storage device that can store data, which can thereafter be read by a computer system. Examples of computer readable medium include read-only memory, random access memory, CD-ROMs, magnetic tape, optical storage devices, and DVD discs. The computer readable medium can also be distributed over a network via interconnected computer systems, so that the computer readable code is stored and executed in a distributed fashion.
Various embodiments of the invention have been described in fulfillment of the various objects of the invention. It should be recognized that these embodiments are merely illustrative of the principles of various embodiments of the present invention. Numerous modifications and adaptations thereof will be apparent to those skilled in the art without departing from the spirit and scope of the present invention. | The present invention provides methods and systems for implementing an improved electronic mail (email) Internet appliance. Improved capabilities include streamlined mechanisms for viewing and managing email messages and for accessing network services. An email Internet appliance obviates the conventional requirements of purchasing a personal computer and tying up a phone line for long periods of time in order to exchange email messages and to read on-line news updates. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a heating collar for heating a pipe or the like by induction heating; more particularly this invention relates to a heating collar having four separate, but cooperating, coils or windings.
2. Background of the Invention
In many processes, in the fabrication and construction of pipes or pipelines, or in the application of coating and the like to such pipes, it is frequently desirable to preheat the pipe in the predetermined area or zone to be treated such as in welding, pipe coating and similar processes. Such zonal heating has been effected in the past, for example, by applying a torch flame to the area to produce the desired heat. However, the heating effects produced by a torch flame are highly localized, and are not suitable for many processes which require a uniform heat application, for instance, around the circumference of the pipe.
For example, in field performed processes in which a coating of epoxy or the like is sprayed onto a previously welded pipe joint, the entire area of the joint to be coated should be uniformly and evenly preheated to a temperature of 300°-500° F. prior to the application of he coating material to enable a desired uniform epoxy coat of, for instance, 25-35 mils to be deposited. Such coating processes are used, for instance, in applications in which pipes are provided with a protective epoxy coat, except for its ends at which welding to adjacent pipe sections in the field is effected. After the welding process, the uncoated joint is coated with epoxy to thereby effect a pipe coated along the entire length of the pipe, including the welded junction, for resisting corrosion and other deleterious influences to which the pipe may be subjected. Uneven heat, such as by torch preheating, may produce uneven or unreliable coatings, which may result in areas of the pipe being undesirably exposed to the elements, resulting in premature pipeline failures. The torch preheating also is slow to perform, usually done manually, and requires carrying the torch and its accessories from each joint to the next.
SUMMARY OF THE INVENTION
The present invention provides a heating apparatus or collar for producing induction currents in a pipe or the like to heat it. This heating collar includes a pair of hinged frames adapted to be removably located or positioned around a pipe. A plurality of electrically conducting wires are carried upon the frames, each wire (except as indicated hereinafter) extending substantially between the unhinged ends of the frames to each encircle the pipe when the collar is closed around the pipe. A plurality of connectors are mounted in the frames to connect one end of each wire to an end of another wire, except for a first and a last wire of each winding, to define four continuous electrically conducting windings around the pipe. The first and last wires of each winding are connected to a source of alternating electrical potential.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of a heating apparatus of the present invention shown in closed position around a pipe which is indicated in cross-section;
FIG. 2 is a side elevational view of the heating apparatus shown in FIG. 1;
FIG. 3 is a perspective view of one form of the male connector assembly for use with the heating apparatus of FIG. 1;
FIG. 4 is a perspective view of one form of the female connector assembly for use with the heating apparatus of FIG. 1;
FIG. 5 is a semi-diagrammatic view of the various connections for the wires on the heating apparatus to show the formation of four separate windings;
FIG. 6 is an electrical circuit diagram of the power source and its connections to the windings of FIG. 5; and
FIG. 7 is a modified form of the circuit diagram shown in FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, a heating apparatus is shown in the form of a hinged collar 10 encircling a pipe 12 to be heated. The collar extends over the pipe both circumferentially, as shown in FIG. 1, and axially (parallel to the axis of the pipe), as shown in FIG. 2. The collar 10 is comprised of a plurality of arcuate shaped sections, such as the two semi-circular frames 14 and 16, hinged together at the top in a manner later to be described. These semi-circular frames 14 and 16 are substantially identical except for their interconnecting bottom ends, also later to be described. The frame 14 is formed from two semi-circular plates 18 and 20 which are interconnected and held in spaced parallel relationship by means of outer rods 22 which are bolted to the semi-circular plates 18 and 20 by means of bolts 24. Similarly, the semi-circular frame 16 is formed by semi-circular plates 26 and 28 which are interconnected and held in spaced apart relationship by means of outer rods 22 (not shown) which are bolted to the semi-circular plates 26 and 28 by means of bolts 24. Each arcuate frame member, 14 or 16, is provided with a pair of circularly arranged and parallel rows of inner rods 30 which are connected to the arcuate plates 18 and 20, and 26 and 28, by means of bolts 32. The wires, later to be described, are wound on the frame members between the two inner rows of rods 30 and, therefore, only the outer row of rods 30 appears in FIG. 2.
The hinged connection between the semi-circular frames 14 and 16 comprises a hinge frame 34 which includes triangular members 36 and 38 disposed outside of the frames 14 and 16 and interconnected by means of a securing rod 40 which is bolted to the triangular members 36 and 38 by means of bolts 42. The triangular frame member 36 is bolted by means of bolt 44 to the semi-circular plates 18 and 26; the bolt 44 passes through overlapping portions of the semi-circular plates 18 and 26 and, therefore, provides a pivot point for the forward portion of the frame assembly as shown. Similarly, the triangular plate 38 is bolted to the semi-circular plates 20 and 28 by means of a bolt 46 which also passes through overlapping portions of these semi-circular plates and, therefore, provides the pivot point for the rear portion of the frame members 14 and 16. A plurality of wires 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68 and 70 are carried on the frame between the inner and outer rows of rods 30 and cover substantially the entire axial width of the collar, as shown in FIG. 2. Wires 48 through 54 inclusive and wires 60 through 66 inclusive extend for the full circumference of the collar from the male connector box to the female connector box, as will be described hereinafter. Wires 68 and 70 connect from the male connector box, as will hereinafter appear, and extend counterclockwise to terminals 3 and 1, respectively, as will be explained hereinafter. Wires 56 and 58, similarly, extend counterclockwise from the male connector box to terminals 7 and 5, respectively, as will be explained hereinafter. On the rear side of the collar 10, that is, from the rear of FIG. 2, a pair of wires 72 and 74 (the major portions of which are hidden) extend in a clockwise direction from the female connector box to terminals 8 and 6, respectively. Similarly, another pair of wires 76 and 78 (the major portions of which are hidden in FIG. 2) extend in a clockwise direction from the female connector assembly to terminals 4 and 2, respectively.
Referring now to FIGS. 1, 3 and 4, the lower portion of the right hand hinge assembly 14 includes a male connector box assembly 80, shown in FIG. 3, while the lower portion of the left hand hinge assembly 16 includes a female connector box or assembly 82, shown in FIG. 4. The male and female assemblies 80 and 82, shown in FIGS. 3 and 4, respectively, are illustrated in these figures in a simplified form, it being understood that FIG. 5 shows a diagrammatic representation of a modified form of these assemblies. At any event, the male assembly 80 consists of a plurality of projections 84 adapted to be received in corresponding recesses 86 in the female connector assembly 82, shown in FIG. 4.
The male connector assembly 80 is contained in an insulating box defined by upper and lower non-conducting plates 88 and 90 and non-conducting side plates 92 and 94. The side plates 92 and 94 are connected to the arcuate plates 18 and 20, respectively, by means of bolts or screws (not shown). Likewise, the female connector assembly 82 is contained in an insulating box consisting of upper and lower non-conducting plates 96 and 98, respectively, and non-conducting side plates 100 and 102, the sides 100 and 102 being connected to the semi-circular plates 26 and 28, respectively.
Each projection 84 on the male conductor assembly is provided with a pair of electrically conducting plates 104 spaced apart apart and separated by an insulating plate 106. In similar fashion, each recess 86 is provided with electrically conducting plates 108 at the sides thereof, and adjacent recesses are separated by non-conducting plates 110. When the heating collar is placed in the position shown in FIG. 1, the projections 84 on the male connector assembly 80 are received in the recesses 86 in the female connector assembly 82 at which time the conducting plates 104 of the male conductor assembly are in contact with the conducting plates 108 of the female connector assembly.
In the modified form shown in FIG. 5, the male connector assembly 80' is provided with narrower projections at the ends formed by single conducting plates 104 which are received in correspondingly narrower recesses at the ends of the female connector assembly 82', it being understood that the portions of the female connector assembly outboard of the end conducting plates 104 are formed of non-conducting material.
With the arrangement shown in FIG. 5, there are four windings on the collar 10 as follows: terminal 1 connects through wire 70 (see also FIG. 2) into the male connector assembly 80' to the left hand conducting plate 104 through the next adjacent conducting plate 108 on the female connector assembly 82' through the wire 66 through conducting plates 104 and 108 to wire 62, through conducting plates 104 and 108 to wire 78 and to terminal 2; the second coil or winding extends from terminal 3 through wire 68 to the male connector assembly 80' through conducting plates 104 and 108, through wire 64 through conducting plates 104 and 108, through wire 60 through conducting plates 104 and 108, through wire 76 to terminal 4; the third coil extends from terminal 5 through wire 58 to the male connector box 80' through conducting plates 104 and 108, through wire 54 through conducting plates 104 and 108, through wire 50 through conducting plates 104 and 108, through wire 74 to terminal 6; the fourth coil or winding extends from terminal 7 through wire 56 to the male connector assembly 80' through conducting plates 104 and 108, through wire 52 through conducting plates 104 and 108, through wire 48 through conducting plates 104 and 108, through wire 72 to terminal 8. Thus, the coil extending between terminals 1 and 2 is interlaced between the coil or winding extending between terminals 3 and 4, or, in other words, is in a bifilar arrangement. The coil or winding extending between terminals 5 and 6 is interlaced with the coil or winding extending between terminals 7 and 8 and, therefore, is also in a bifilar arrangement. Since these two bifilar arrangements are disposed in end to end relationship, the ultimate result is a quadrafilar arrangement.
Referring now to FIG. 6, there is shown a circuit diagram which includes a power generator generally designated by the reference numeral 120. This power generator is basically in the form of a brushless alternator having a single primary winding P and a pair of secondaries S1 and S2. The construction of this power generator is such that it is capable of delivering 50 KVA preferably at a frequency of about 800 cycles. If the two secondaries S1 and S2 were connected in series as shown, the generator 120 would be capable of delivery 220 volts. However, under the circumstances where the present invention was employed, the requirements were that the voltage should not exceed 110 volts. Accordingly, the secondaries S1 and S2 of FIG. 6 have been connected to the circuit of FIG. 5 in the following manner.
The upper terminal 122 of the secondary S1 is connected to the upper terminal 124 of the secondary S2 and the lower terminal 126 of the secondary S1 is connected to the lower terminal 128 of the secondary S2. The upper terminal 122 is also connected through contactor K1, through fuses F1 and F2 to terminals 2 and 4, respectively; the upper terminals 122 and 124 are also connected through contactor K2, through fuses F3 and F4 to terminals 6 and 8, respectively. The lower terminals 126 and 128 connect with terminals 1, 3, 5 and 7 thereby providing a source of 110 volts alternating current for the four coils or windings on the collar. If desired, the voltage to the coils or windings can be measured by means of a voltmeter 130 which is placed across the output terminals of the two secondaries. If it is desired to measure the current to any one of the four windings, a current transformer 132 can be placed around any one of the wires leading to a given winding and the amount of current through that particular wire can be measured by an ammeter 134 which is connected to the current transformer 132. Capacitors C1, C2, C3 and C4 are placed across the windings as shown.
The circuit of FIG. 7 shows an arrangement where the secondaries of the power transformer 120 are not connected to each other and are feeding two separate windings each on the heating collar. As shown in FIG. 7, the upper terminal 122 connects through the contactor K1 and through the fuses F1 and F2 to the terminals 2 and 4 only. The lower terminal 126 of the secondary S1 feeds into terminals 1 and 3 only. The upper terminal 124 of the secondary S2 feeds through contactor K2, fuses F3 and F4, to terminals 6 and 8 only and the lower terminal 128 of the secondary S2 feeds to terminals 5 and 7 only. In this way, the windings extending from terminals 1 and 2 and terminals 3 and 4 are fed separately from the windings extending between terminals 5 and 6 and terminals 7 and 8.
Returning now to a further consideration of FIGS. 3 and 4, in order to maintain the electrically conductive and insulating blocks and plates in their relative positions, an insulating rod is provided through each of the parallel alignments of the plates; insulating rod 140, for example, extends through the side insulating plates 92 and 94 of the insulating box of the male connector assembly and also extends through the intermediate conducting plates 104 and non-conducting plates 106 and any other insulating blocks interposed in the arrangement; a similar insulating rod (not shown) is employed to maintain the relative location of the insulating plates and blocks and conducting plates on the female connector assembly 82. A tightening nut 142 is provided on the side of the female connector assembly. This nut has a shank (not shown) which is threadedly received in a hole in the semi-circular plate 26, and this shank extends inwardly into contact with a metal plate (not shown) which bears against the insulating plate immediately inboard of the semi-circular plate 26. Thus, by tightening the nut 142 a compressive force can be exerted across the entire assembly when the male and female connectors are disposed in their interdigitated relationship thereby locking the collar in the position shown in FIG. 1.
When the heating collar is placed upon and around a pipe 12 as shown in FIG. 1, top rollers 144 will support the heating collar 10 on the pipe 12 and will also permit the collar to be rolled along the length of the pipe for a limited distance. Side rollers 146 do not necessarily contact the side of the pipe 12 but serve to keep the collar 10 generally centrally disposed around the pipe and prevent scraping of the sides of the collar 10 against the sides of the pipe.
The wires forming the various windings or coils on the collar 10 are preferably of "double O" gauge copper with an insulating coat thereon. With the generator shown in FIGS. 6 and 7, this arrangement should be capable of heating a pipe of iron containing material to between approximately 300°-500° F. or higher.
In operation, the heating collar 10 is placed in an encircling arrangement around the pipe 12 by first opening the semi-circular frames 14 and 16 about the hinge 34. The collar 10 is then lowered onto the pipe 12 until the rollers 144 come to rest upon the top surface of the pipe. The collar is then closed by placing the connector assemblies in the closed position shown in FIG. 1 after which the nut 142 is tightened. The circuit shown in FIG. 6 or 7 is then actuated after the proper connections have been made and the pipe can be heated to the desired temperature, for example, 500° F. After the pipe is heated, it is ready for the subsequent steps to be formed, such as depositing the epoxy coating or welding the preheated joint, etc. The heating collar can be easily moved from the preheating area by merely rolling the collar 10 along the axis of the pipe 12 upon the rollers 144. The heating collar can then be located at the next junction to be heated or, alternatively, the coil can easily be removed by first loosening the nut 142 and opening up the hinged sections and lifting the collar off the pipe.
Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications, apart from those shown or suggested herein, may be made within the spirit and scope of this invention. | Apparatus for producing induction currents in a pipe to heat the same comprising an axially extending collar adapted to removably surround the pipe, the collar including at least two arcuate frames hingedly connected in end to end circumferential relationship and having a pair of free ends adapted to be opened for placing the frames around the pipe, a plurality of electrically conducting wires carried upon the frames across the axial width thereof and extending circumferentially between the free ends, a connector assembly mounted at each free end, each connector assembly having a plurality of connectors, each connector of each assembly being connected to an end of a wire and being connected electrically to a connector of the other assembly when the frames are in closed position around the pipe, the wires on one axial half of the collar being connected to each other to form two interlaced bifilar windings; the wires at the other axial end of the collar being interconnected to form two interlaced bifilar windings arranged in end to end axial relationship with the bifilar windings of the first axial end of the collar thereby resulting in an overall quadrafilar winding for the collar, and a source of alternating electric potential connected to the windings to produce induction heating in the pipe. | 7 |
BACKGROUND
[0001] This disclosure relates to lavatory systems.
[0002] Unpleasant odours are all too prevalent in lavatory systems, for example public lavatories, especially public urinals. While such systems will usually employ water traps to prevent sewer gas from infiltrating, odours upstream of the water trap have only been able to be dealt with heretofore by regular flushing of the water trap to remove accumulated urine and/soil, by attempting to mask the odour by other strong smells such as pine or naphthalene, or by ventilation as a whole of, and especially by air extraction from, the room (hereafter: “lavatory room”) in which the lavatory system is installed.
[0003] The present disclosure adopts a quite different approach. As explained in more detail below with reference to specific embodiments, we seek to remove odour directly from its source.
SUMMARY OF THE DISCLOSURE
[0004] In accordance with a first aspect of this disclosure, there is provided an extraction system for a lavatory unit selected from urinals and toilet bowls, the lavatory unit including a receptacle for human liquid or solid waste, the receptacle having an outlet for such waste; the extraction system being adapted to extract odours from a region upstream of the receptacle outlet, and comprising: a shallow housing having front and rear walls, and side walls interconnecting the front and rear walls, the depth of the housing from the front to the rear wall being substantially less than distances across the front and rear walls from one side to the other thereof, the housing mounting a centrifugal fan with its axis perpendicular to the rear wall, the fan having an axial air inlet located centrally of the front wall and an air outlet generally tangential to the fan in a side wall of the housing, the housing being adapted for mounting with a ducting connection providing for airflow for odour-laden air from a region of the lavatory unit upstream of the receptacle outlet to the air inlet and with the air outlet being coupled to discharge air from the air outlet in a manner removing odour from the vicinity of the lavatory unit.
[0005] Where the lavatory unit has a water trap associated with the receptacle outlet, the housing is may be provided with two ducting connections, namely a first connection from a region of the lavatory unit upstream of the water trap to the air inlet and a second connection from the air outlet to the lavatory unit downstream of the water trap.
[0006] Accordingly, in a second and alternative aspect of this disclosure, there is provided an extraction system for a lavatory unit, selected from urinals and toilet bowls, of the kind including a water trap; the extractor system being adapted to extract odours from a region upstream of the water trap, and comprising: a shallow housing having front and rear walls and side walls interconnecting the front and rear walls, the depth of the housing from the front to the rear wall being substantially less than distances across the front and rear walls from one side to the other thereof, the housing mounting a centrifugal fan with its axis perpendicular to the rear wall, the fan having an axial inlet located centrally of the front wall and an outlet generally tangential to the fan in a side wall of the housing, the housing being adapted for mounting with a ducting connection from a region of the lavatory unit upstream of the water trap to the inlet and a ducting connection from the outlet to the lavatory unit downstream of the water trap.
[0007] Alternatively, the air outlet may be coupled to an absorbent filter unit adapted to absorb odour from air discharged from the extraction system via said air outlet to atmosphere. Suitably, the absorbent filter unit comprises a carbon filter, preferably capable of regeneration.
[0008] Whereas the housing is preferably adapted for mounting its rear wall to a generally vertical surface such as a wall or an internal surface of a water cistern, as explained below, it may be sufficient for the housing to be merely supported by the ducting to which it is coupled, so that no direct connection between the housing and any supporting surface may be required.
[0009] Where the outlet is coupled to a soil pipe, a non-return valve is suitably included in the ducting connection from the outlet to the soil pipe.
[0010] Where the lavatory unit comprises a receptacle in the form of a toilet bowl with a cistern, the housing may be mounted to a preferably generally vertical surface internally of the cistern above the maximum water level thereof. The ducting connection may comprise a pipe or hose coupled from a region of the toilet bowl adjacent its rim to the inlet. In this case the housing may simply be fitted to its ducting connections so as to be above the maximum water level of the cistern, without fixture to any surface of the cistern. Where the cistern has a flushing mechanism with a built-in overflow into the toilet bowl and a cistern lid with a seal, the inlet may simply be open to the interior of the cistern above its water line, and the ducting connection to the inlet may comprise the said built-in overflow.
[0011] In an alternative arrangement in which the lavatory unit comprises a receptacle in the form of a toilet bowl with a cistern having a flushing mechanism with a built-in overflow into the toilet bowl and a cistern lid with a seal, the housing may be mounted to a wall adjacent the cistern, and the ducting connection to the inlet may comprise a pipe coupled between the inlet and the water cistern above its maximum water level and the said built-in overflow. Alternatively, the housing may simply be fitted to the ducting connections without any direct fixing of the housing to the wall.
[0012] In installations in which the housing is mounted interiorly of a water cistern and the ducting connection from the outlet to the lavatory unit downstream of the water trap comprises piping connecting the outlet to the soil pipe via a non-return valve, power connection to a motor for the fan may be via wiring that extends from the said motor through said outlet and along said piping, issuing through the wall thereof, at a position upstream of the non-return valve, for electrical connection to a source of electric power.
[0013] Where the lavatory unit comprises a urinal with a urinal bowl having an outlet for urine therefrom, the housing is conveniently mounted to a wall alongside the urinal bowl, the ducting connection to the air inlet comprising piping tapping into plumbing for the urinal unit downstream of the outlet from the urinal bowl, and immediately above its water trap, where the urinal is fitted with a water trap, airflow of odour laden air from a region upstream of the urinal outlet being via that outlet, the said plumbing and the ducting connection to the air inlet. Where the urinal is fitted with a water trap, there may be ducting connection from the air outlet via piping coupling the air outlet to a waste pipe from the urinal unit connected to the downstream side of the water trap. Alternatively, the air outlet may simply be coupled to a said absorbent filter unit adapted to absorb odour from air discharged from the extraction system via said air outlet to atmosphere.
[0014] Where the lavatory unit comprises a urinal of the kind comprising a trough in which urine is collected before passing via an outlet comprising a drain from the trough and a water trap to a waste pipe, the housing is mounted to a wall, the ducting connection to the air inlet comprising piping tapping into plumbing for the urinal between the drain and the water trap. The air outlet may be coupled to a ducting connection comprising piping coupling the air outlet to the said waste pipe downstream of the water trap. Alternatively, the air outlet may simply be coupled to a said absorbent filter unit adapted to absorb odour from air discharged from the extraction system via said air outlet to atmosphere.
[0015] In the case of urinals, the fan preferably runs continuously, in which case, a non-return valve may be omitted. However, for added security to prevent back-flushing of sewer gas, should there be a power-cut, a non-return valve may be fitted regardless.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Referring now to the accompanying drawings by way of example only:
[0017] FIG. 1 shows an exploded sectional view of a fan and housing taken along the line I-I in FIG. 2 ;
[0018] FIG. 2 is an elevational view of the fan and housing of FIG. 1 as seen in the direction of the arrow A in FIG. 1 ;
[0019] FIG. 3 is a scrap sectional view taken along the lines in FIG. 2 ;
[0020] FIG. 4 is a generally schematic view of an embodiment of extraction system applied to a urinal;
[0021] FIG. 5 is a longitudinal sectional view through a non-return valve;
[0022] FIG. 6 is a generally schematic view of an embodiment of extraction system applied to a toilet bowl and cistern;
[0023] FIG. 7 is a generally schematic view of a variation of the extraction system of FIG. 6 ; and
[0024] FIG. 8 shows an alternative embodiment of fan and housing with discharge of air from the air outlet of the extraction system via an absorbent filter unit to atmosphere.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0025] A shallow housing 1 for a centrifugal fan 2 is shown in FIGS. 1 and 2 . The housing comprises a front wall 3 and a rear wall 4 . Centrifugal fan 2 is preferably a radial blower. Suitable 12 volt DC radial blowers with electronically commutated external rotor motor are available from ebm-papst UK Ltd of Chelmsford, Essex under the trade designation REF 100-11/12, and have a total thickness of fan and motor of under 25 mm. The motor of fan 2 is mounted by screws to mounts 5 on rear wall 4 . An inlet stub pipe 6 is mounted centrally of front wall 3 via a frustoconical portion 7 to define plenum 8 for inlet air on the inlet side of fan 2 . The fan draws air in axially and ejects it in a tangential direction. The fan blades are preferably backwardly curved to reduce noise and increase efficiency. Side walls 9 extending perpendicular to the front wall extend from each edge of front wall 1 towards the rear wall. An interior wall 10 is mounted within a chamber effectively defined by the front wall and side walls to guide air flow towards an outlet stub pipe 11 mounted in one side wall. It will be seen that interior wall 10 follows the cylindrical profile of the fan at a fixed radial separation over three-quarters of a circumference before diverging to outlet 11 . Front wall 3 is generally square apart from three of its four corners, which are cut-away. As best shown in the scrap sectional view of FIG. 3 , apertured triangular flanges 12 are mounted to side walls 9 at their edges furthest from front wall 3 at positions corresponding to the cut-away corners. In practice the main portion 13 of housing 1 , comprising the front wall with its sidewalls, the flanges and the interior wall may be moulded, for example from acrylic plastics, in one piece. Rear wall 4 forms a complete square with apertured corners corresponding to the positions of apertured flanges 12 . A shallow upstanding wall 14 is integrally formed on rear wall 4 , again by moulding the rear wall 4 in one piece, at positions just in board of the positions occupied by sidewalls 9 when the main portion 13 is offered up to rear wall 4 already mounting the fan 2 and motor. Fixings inserted through the apertures in flanges 12 and rear wall 4 enable the fan and its housing 1 to be mounted to a generally vertical surface. As can be seen from FIG. 1 , the depth of the housing from the front to the rear wall is substantially less than distances across the front and rear walls from one side to the other.
[0026] Providing cut-away corners reduces the space occupied by the housing 1 . Thus, the remaining corner may also be cut-away, although this is not shown in FIG. 2 .
[0027] Turning now to FIG. 4 , a urinal 15 comprises a urinal basin 16 with a drain 17 from which urine, together with water used periodically to flush the urinal basin, passes via a conventional water trap 18 to a waste pipe 19 . Urinal basin 16 will generally be mounted to a vertical wall. A housing 1 with fan 2 and motor is conveniently mounted alongside urinal basin 16 on the same wall. Ducting 20 is provided between a region upstream of the water trap and inlet 6 of housing 1 . The ducting 20 here comprises piping tapped into the plumbing for the urinal unit below drain 17 immediately above its water trap 18 . Ducting 21 connects outlet 11 with waste pipe 19 downstream of water trap 18 .
[0028] The fan motor suitably runs continuously, avoiding reverse penetration of sewer gas, while substantially reducing the odour of urine without needing to mask it with another strong smell. However, for additional security against sewer gas, a non-return valve 22 may be incorporated in the system, suitably between the outlet 11 of housing 1 and waste pipe 19 . As shown in FIG. 5 , valve 22 comprises a generally cubic housing 23 defining a valve chamber 24 therewithin. Two stub pipes 25 , 26 are coupled to housing 23 . One stub pipe 25 is simply joined to one wall 27 of housing 23 . The other penetrates through a wall 28 of the housing 23 opposite wall 27 , its end 29 being cut at an angle. A flap valve 30 is pivoted at 31 so as to overlie cut end 29 by gravity. Air pressure created by fan 2 is sufficient to open flap valve 30 to allow odour-laden air to pass. When the motor stops, the flap valve will close cut end 29 preventing back flushing of sewer gas.
[0029] The system illustrated in FIG. 4 has the advantage that air extraction is applied to the region in which the odour is generated, so that significantly less power is consumed as compared with an extraction system seeking to reduce odour by ventilating the lavatory room as a whole. A typical motor for fan 2 has a consumption of 7.5 watts/hour.
[0030] The extraction system illustrated in FIG. 4 may be applied equally well to a urinal of the kind comprising a trough in which urine is collected before passing via a drain from the trough and a water trap to a waste pipe. In this case, housing 1 would be mounted to a convenient wall, the ducting connection to the inlet 6 comprising piping tapping into plumbing for the urinal between its drain and its water trap, and the ducting connection from the outlet 11 comprises piping coupling the outlet 11 to the said waste pipe downstream of the water trap.
[0031] Similar odour-reducing extraction may be applied to the toilet bowl of a water closet, as explained with reference to FIGS. 6 and 7 .
[0032] A water closet 32 is schematically illustrated in FIG. 6 and comprises a toilet bowl 33 with an outlet 34 to a conventional S-bend water trap exiting into a soil pipe 35 . Toilet bowl 33 is flushed from a water cistern 36 by a flushing mechanism, indicated schematically at 37 , which may be operated mechanically by a user (lever, press-button, etc) in conventional fashion or under automatic control (for example a proximity detector) again in a manner known per se, and is typically lifted to allow water within the cistern to pass through an opening into a conventional down pipe 38 issuing into toilet bowl 33 Cistern 36 has a water feed 39 from an external source controlled by a float valve 40 , here a conventional ball-cock 41 , which sets a maximum water level in the cistern. The flushing mechanism 37 here includes a built-in overflow 42 into the toilet bowl 33 via the normal flushing down pipe 38 . The cistern 36 has a cistern lid 43 with a seal 44 . In the arrangement of FIG. 6 , the housing 1 , with fan 2 and motor, is mounted to a generally vertical surface 45 internally of the cistern 36 above the maximum water level thereof. The inlet 6 is simply open to the air space above the water level in the cistern. The outlet 11 is coupled via piping 46 and a non-return valve 22 to soil pipe 35 downstream of the S-bend. Operation of the extractor unit creates a partial vacuum within the cistern drawing odour-laden air from the toilet bowl via ducting provided by the down pipe 38 and overflow pipe 42 into the airspace above the water line within the cistern and hence to inlet 6 , the odour-laden air being exhausted via piping 46 to the soil pipe.
[0033] Rather than employing the overflow and normal down pipe, a housing 1 within the cistern 36 may be coupled by a separate pipe from the toilet bowl adjacent its rim to inlet 6 .
[0034] In another alternative arrangement shown in FIG. 7 , housing 1 is mounted alongside cistern 36 , inlet 6 being coupled to the air space above the water level in the cistern via a pipe 47 through the wall of the cistern.
[0035] Whereas urinal systems will normally operate continuously, toilet bowl systems may be set to operate only intermittently, for example by the motor being switched on for a set period from each operation of the flushing mechanism to exhaust odour-laden air from the bowl.
[0036] In the arrangements of FIGS. 4 and 7 , there is no problem in supplying electric power to the fan motor. A suitable 12 volt transformer/adaptor 48 may be mounted at a convenient position and coupled to the mains power supply, wiring 49 providing DC power to the motor. With in-cistern installation of the housing 1 , wiring 50 from transformer/adaptor 48 is conveniently fed into cistern 36 via piping 46 and outlet 11 , as shown in FIG. 6 .
[0037] As an alternative, in any of the above arrangements, to fixing the rear of the housing to a (preferably, generally vertical) surface such as a wall or an interior surface of a water cistern, the housing may simply be fitted to, and supported by, the ducting. In this case, the apertured flanges 12 may be omitted.
[0038] Because the preferred fan motors have such small power requirements in all the illustrated arrangements, several such motors may be coupled to a single transformer/adaptor. The adoption of a shallow housing 1 enables the housing to be mounted in an inconspicuous position against the wall of the lavatory room, or within the cistern itself as in the FIG. 6 arrangement.
[0039] For ease of comparison, parts of the extraction system shown in the embodiment of FIG. 8 that correspond to parts of the extraction systems illustrated in FIGS. 1 , 2 and 3 are identified with like reference numerals.
[0040] In FIG. 8 , a shallow housing 1 for a centrifugal fan (not shown, but identically mounted to the fan of FIGS. 1 to 3 ) comprises a front wall 3 and a rear wall 4 . An air inlet stub pipe 6 is mounted centrally of front wall 3 via a frustoconical portion 7 to define plenum 8 for inlet air on the inlet side of the fan. The fan draws air in axially and ejects it in a tangential direction. Side walls 9 extending perpendicular to the front wall extend from each edge of front wall 1 towards the rear wall. Rather than being provided with an outlet stub pipe serving as an air outlet, as in the embodiment of FIGS. 1 to 3 , in the present embodiment, tangentially driven air from the centrifugal fan issues into an absorbent mass 101 contained within a filter housing 102 defined between extended portions 103 and 104 of the front and rear walls 3 and 4 . In this embodiment filtered air is discharged to atmosphere through a grille 105 formed in the extended top wall 103 . Absorbent mass 101 is suitably a carbon filter. The carbon filter may be provided in the form of a replaceable filter cartridge 106 , as illustrated, in which the filter mass 101 is mounted to an end wall 107 fitted with a tab 108 . When the filter mass is full, a user may simply withdraw the cartridge from the housing 102 by pulling on tab 108 . In the case of a carbon filter, the cartridge can be regenerated by heating to drive off the trapped odour molecules, and can then be re-used. Optionally, as shown, there may be a second cartridge 109 behind a further grille 110 , and with a similar tab 111 for removing and replacing it. Cartridge 109 may contain a perfume.
[0041] Variations are possible. Whereas the filter and the optional perfume source are here mounted within the same housing as the fan, which provides a particularly compact construction, this is not necessary. The filter could be coupled to the fan housing air outlet by ducting to discharge filtered air to atmosphere at a position remote from the fan housing.
[0042] Apart from discharge of filtered air to atmosphere, either in the immediate vicinity of the fan housing, as in the above illustrated arrangement, or at a remote position, as in the above described variation, the extraction system may be mounted to urinals or lavatories in all the ways described and illustrated in FIGS. 4 , 6 and 7 . | An extraction system for removing unpleasant odor includes a housing having front and rear walls and side walls interconnecting the front and rear walls. The depth of the housing from the front to the rear wall is substantially less than distances across the front and rear walls from one side to the other thereof. A centrifugal fan is mounted to the housing with an axis of the fan being perpendicular to the rear wall. The fan has an axial air inlet located centrally of the front wall for receiving odor-laden air and an air outlet from the fan is tangential to the fan and coupled to discharge air to atmosphere from the extraction system. An absorbent filter unit is located within the housing downstream of the fan and includes an absorbent mass and a perfume source. Air discharged to atmosphere is both substantially free of the odor and scented via the absorbent filter unit. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 12/972,674 filed Dec. 20, 2010, the disclosure of which is hereby incorporated in its entirety by reference herein.
TECHNICAL FIELD
[0002] The illustrative embodiments generally relate to the automatic maintenance of data contained on a wireless device.
BACKGROUND
[0003] Twenty or thirty years ago, people generally had one or two points of contact, a home phone number and maybe a business phone number. Unless a person moved or changed jobs, these numbers were unlikely to change, and the numbers were often recorded by hand in a paper contact phone book or a ROLODEX.
[0004] Nowadays, however, the landscape has dramatically changed. With the onset of email, people often have a multitude of “addresses” at which they can be contacted.
[0005] Further, the prevalence of cellular phones has added an additional wrinkle Users may buy new phones, without changing physical addresses, and change numbers. Additionally, since cellular phones store phone numbers, many people have stopped remembering phone numbers of friends and family. Of course, if a cellular phone is lost or ruined, all these stored numbers (and/or email addresses) may be lost.
[0006] Cellular phone stores may offer an option to have a list of numbers on an existing phone printed or backed up. But this requires a trip to the store to have this service performed. Even if the backup capability is available on a home-PC, through a wired connection, the user may have to remember to connect the phone and activate the back-up program.
SUMMARY
[0007] In a first illustrative embodiment, a computer-implemented method includes downloading a plurality of data elements from a wireless device to a connected vehicle computing system (VCS). The illustrative method further includes determining, via the VCS, whether a user account, corresponding to the wireless device, exists in storage.
[0008] Also, the illustrative method includes determining, via the VCS, whether the user account currently has stored data elements of the same type as the downloaded data elements associated therewith. The method further includes comparing, via the VCS, the downloaded data elements to the stored data elements. This comparison may be contingent on whether the user account has stored data elements associated therewith.
[0009] This illustrative method also includes storing any downloaded data elements not currently existing in the data elements associated with the user account and not in conflict with data elements associated with the user account.
[0010] The method further includes resolving conflicts, via the VCS, between downloaded data elements and currently existing data elements, to establish which of the conflicting elements is representative of a proper version of the element. Finally, the illustrative method includes storing the proper version of the element resulting from each conflict resolution.
[0011] In a second Illustrative embodiment, a method for populating a wireless device with data includes connecting to a wireless device from a vehicle computing system (VCS) and determining, via the VCS, if a set of data elements on the wireless device is below a certain size threshold.
[0012] The illustrative method additionally includes determining, via the VCS, if a user account corresponds to a user of the wireless device and determining, via the VCS, if the user account has one or more data elements of a certain type for which it was determined that the data elements on the wireless device were below the threshold. Finally, the method includes automatically uploading, from the VCS to the wireless device, the data elements of the certain type.
[0013] In a third illustrative embodiment, a computer-implemented method for replacing an invalid data element includes determining, via a vehicle computing system (VCS) that a data element is invalid. The illustrative method further includes accessing one or more social networking sites, through the VCS, associated with a user account corresponding to a wireless device containing the invalid data element.
[0014] In this illustrative embodiment, the method also includes, for each social networking site accessed through the VCS, determining whether or not a data type corresponding to the invalid data element is available for a party corresponding to the invalid data element. In this embodiment, the method additionally includes comparing a data element stored on the social networking site under the data type with the invalid data element, if the data type is available.
[0015] Also, according to this illustrative method, if the data element stored on the social networking site differs from the invalid data element, the invalid data element stored on at least one of a local storage or the wireless device is replaced with the data element stored on the social networking site.
[0016] In a fourth illustrative embodiment, a computer-implemented method for replacing an invalid data element includes determining, via a vehicle computing system (VCS) that a data element is invalid and determining whether an email address is associated with the invalid data element.
[0017] This illustrative method also includes, for one or more email addresses associated with invalid data elements, sending a request email to the email address associated with the respective invalid data element. The request email may include a request for an update of the data element.
[0018] The illustrative method further includes receiving a response to the request email, the response including a valid response element to the request for an update of the data element. Finally, the illustrative method includes replacing the invalid data element with the valid response element.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 shows an illustrative example of a vehicle computing system and a remote network;
[0020] FIG. 2 shows an illustrative example of a process for data storage, maintenance, and recovery;
[0021] FIG. 3 shows an illustrative example of a process for data restoration;
[0022] FIG. 4A shows an illustrative example of a process for email address verification;
[0023] FIG. 4B shows an illustrative example of a process for invalid email address automatic correction;
[0024] FIG. 5 shows an illustrative example of a process for cross account data maintenance; and
[0025] FIGS. 6A and 6B show illustrative examples of processes for invalid phone number automatic correction.
DETAILED DESCRIPTION
[0026] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
[0027] Although the following describes the invention in terms of illustrative embodiments, these examples are provided for non-limiting illustrative purposes only, and are not intended to limit the scope of the invention thereto.
[0028] FIG. 1 illustrates an example block topology for a vehicle based computing system 1 (VCS) for a vehicle 31 . An example of such a vehicle-based computing system 1 is the SYNC system manufactured by THE FORD MOTOR COMPANY. A vehicle enabled with a vehicle-based computing system may contain a visual front end interface 4 located in the vehicle. The user may also be able to interact with the interface if it is provided, for example, with a touch sensitive screen. In another illustrative embodiment, the interaction occurs through, button presses, audible speech and speech synthesis.
[0029] In the illustrative embodiment 1 shown in FIG. 1 , a processor 3 controls at least some portion of the operation of the vehicle-based computing system. Provided within the vehicle, the processor allows onboard processing of commands and routines. Further, the processor is connected to both non-persistent 5 and persistent storage 7 . In this illustrative embodiment, the non-persistent storage is random access memory (RAM) and the persistent storage is a hard disk drive (HDD) or flash memory.
[0030] The processor is also provided with a number of different inputs allowing the user to interface with the processor. In this illustrative embodiment, a microphone 29 , an auxiliary input 25 (for input 33 ), a USB input 23 , a GPS input 24 and a BLUETOOTH input 15 are all provided. An input selector 51 is also provided, to allow a user to swap between various inputs. Input to both the microphone and the auxiliary connector is converted from analog to digital by a converter 27 before being passed to the processor. Although not shown, numerous of the vehicle components and auxiliary components in communication with the VCS may use a vehicle network (such as, but not limited to, a CAN bus) to pass data to and from the VCS (or components thereof).
[0031] Outputs to the system can include, but are not limited to, a visual display 4 and a speaker 13 or stereo system output. The speaker is connected to an amplifier 11 and receives its signal from the processor 3 through a digital-to-analog converter 9 . Output can also be made to a remote BLUETOOTH device such as PND 54 or a USB device such as vehicle navigation device 60 along the bi-directional data streams shown at 19 and 21 respectively.
[0032] In one illustrative embodiment, the system 1 uses the BLUETOOTH transceiver 15 to communicate 17 with a user's nomadic device 53 (e.g., cell phone, smart phone, PDA, or any other device having wireless remote network connectivity). The nomadic device can then be used to communicate 59 with a network 61 outside the vehicle 31 through, for example, communication 55 with a cellular tower 57 . In some embodiments, tower 57 may be a WiFi access point.
[0033] Exemplary communication between the nomadic device and the BLUETOOTH transceiver is represented by signal 14 .
[0034] Pairing a nomadic device 53 and the BLUETOOTH transceiver 15 can be instructed through a button 52 or similar input. Accordingly, the CPU is instructed that the onboard BLUETOOTH transceiver will be paired with a BLUETOOTH transceiver in a nomadic device.
[0035] Data may be communicated between CPU 3 and network 61 utilizing, for example, a data-plan, data over voice, or DTMF tones associated with nomadic device 53 . Alternatively, it may be desirable to include an onboard modem 63 having antenna 18 in order to communicate 16 data between CPU 3 and network 61 over the voice band. The nomadic device 53 can then be used to communicate 59 with a network 61 outside the vehicle 31 through, for example, communication 55 with a cellular tower 57 . In some embodiments, the modem 63 may establish communication 20 with the tower 57 for communicating with network 61 . As a non-limiting example, modem 63 may be a USB cellular modem and communication 20 may be cellular communication.
[0036] In one illustrative embodiment, the processor is provided with an operating system including an API to communicate with modem application software. The modem application software may access an embedded module or firmware on the BLUETOOTH transceiver to complete wireless communication with a remote BLUETOOTH transceiver (such as that found in a nomadic device).
[0037] In another embodiment, nomadic device 53 includes a modem for voice band or broadband data communication. In the data-over-voice embodiment, a technique known as frequency division multiplexing may be implemented when the owner of the nomadic device can talk over the device while data is being transferred. At other times, when the owner is not using the device, the data transfer can use the whole bandwidth (300 Hz to 3.4 kHz in one example).
[0038] If the user has a data-plan associated with the nomadic device, it is possible that the data-plan allows for broad-band transmission and the system could use a much wider bandwidth (speeding up data transfer). In still another embodiment, nomadic device 53 is replaced with a cellular communication device (not shown) that is installed to vehicle 31 . In yet another embodiment, the ND 53 may be a wireless local area network (LAN) device capable of communication over, for example (and without limitation), an 802.11g network (i.e., WiFi) or a WiMax network.
[0039] In one embodiment, incoming data can be passed through the nomadic device via a data-over-voice or data-plan, through the onboard BLUETOOTH transceiver and into the vehicle's internal processor 3 . In the case of certain temporary data, for example, the data can be stored on the HDD or other storage media 7 until such time as the data is no longer needed.
[0040] Additional sources that may interface with the vehicle include a personal navigation device 54 , having, for example, a USB connection 56 and/or an antenna 58 ; or a vehicle navigation device 60 , having a USB 62 or other connection, an onboard GPS device 24 , or remote navigation system (not shown) having connectivity to network 61 .
[0041] Further, the CPU could be in communication with a variety of other auxiliary devices 65 . These devices can be connected through a wireless 67 or wired 69 connection. Also, or alternatively, the CPU could be connected to a vehicle based wireless router 73 , using for example a WiFi 71 transceiver. This could allow the CPU to connect to remote networks in range of the local router 73 . Auxiliary device 65 may include, but are not limited to, personal media players, wireless health devices, portable computers, and the like.
[0042] Using a connection automatically established with a paired wireless device, a vehicle computing system can backup, track, update and even correct wireless device data. In an environment where more than one paired device is present, at least a primary (or higher ranking) device will be managed in any given instance. When only one device is present, unless pairing is disabled, data management will automatically occur for that device, without a need for driver intervention.
[0043] Additionally, such a system can utilize Internet based tools to update, delete and correct stored data. It is possible, in such an environment, for a person's entire email list and/or phone list, for example, to be checked in the background while a drive is occurring. Through use of social networking sites, and assuming that information posted on these sites is accurate, a vehicle computing system is capable of automatically actively managing wireless data in the background.
[0044] FIG. 2 shows an illustrative example of a process for data storage, maintenance, and recovery. In this illustrative embodiment, a vehicle computing system first connects to a paired wireless device (or is paired and connected to a device, or connects to a device if no pairing is needed, etc.) 201 . Once the connection is established, the vehicle computing system downloads some or all of the data stored on the device 203 .
[0045] In this illustrative embodiment, examples are given with respect to contact data stored on the device, but the methods described herein could also be used, for example, to update and/or backup programs, pictures, movies, sound, etc.
[0046] The computing system then checks to see if data for a user account associated with the wireless device already exists 205 . This data could have been previously downloaded from a wireless device (the same device or a different device), uploaded by a user, etc. If there is no data currently associated with the wireless device (either if there is no account, or if the account is empty), the data from the wireless device is added to the account 207 . This data may be saved on the vehicle computing system and associated with this account in future situations.
[0047] If there is existing data stored on the vehicle computing system already, the data from the wireless device is compared to the existing data. In this illustrative embodiment, the data is compared one contact at a time 209 .
[0048] If there is no data on the phone to use for comparison 211 , i.e., the phone is empty of contacts, then it is likely that the phone is either a new phone or the phone has had its memory erased for some reason. In an instance such as this, the system may ask the user (or automatically decide) if locally stored data associated with that phone or user account should be added to the empty device 213 . If the user does not want to add the data, the process exits (since there is no data for comparison and the stored data is not to be added to the phone).
[0049] If the user wishes to add the data, the data is transferred from the vehicle computing system storage to the user's wireless device 227 . In some instances, a password or PIN may be associated with the account to prevent unwanted access to account data by unauthorized users.
[0050] If the wireless device was not empty 211 , then the system checks for a variance in the data associated with a particular contact 215 . For example, a new phone number could exist, a different phone number could exist, or a new or different email (or other associated data, address, fax number, etc) could exist.
[0051] It is also possible that the variance is simply that a particular number stored on the device is simply not present on the local storage, or vice versa. Moving through the data, in a situation such as this, could comprise, for example, moving through vehicle stored data that had no remote correspondence after the remote data had been parsed. Similarly, if the remote (on the device) data is parsed in alphabetical order, gaps in the local storage will be discovered.
[0052] If all the data associated with a contact is the same 215 , the system advances to the next piece of data 225 and performs the comparison process, unless no data remains to be analyzed 229 . As previously noted, since all the data (remote and locally stored) is currently on the temporary or permanent memory of the vehicle computing system, the data advancement may parse both sets of data doing two way comparisons in order to update both memories (the remote memory and the local vehicle computing system memory) with a single pass. It would also be possible, of course, to parse the data remotely on the device and then additionally (if desired) parse local data elements that had not yet been considered (or all the local data).
[0053] If there is a variance in the data 215 (for example, without limitation, local data differs from the data obtained from the remote source, or vice versa), the system may first check to see if there is simply additional data 217 . In this illustrative embodiment, additional data is distinguished from different data. For example, without limitation, additional data could be an instance of a second phone number associated with the data from the remote device, when a first number associated with the data from the remote device already exists in duplicate in the local storage. Or a new email address (if no email address existed or if a different, duplicated email address existed, etc.).
[0054] The additional data is added to the missing location 219 (be it on the local storage or on the remote storage), as a comparison may be made bi-directionally based on data. If data is to be added to the remote storage device (wireless device), a driver may be asked in advance, since there is a possibility that the driver intentionally deleted the data, and does not want it re-added if the last local store included the now-deleted data.
[0055] Next, the data variance is checked to see if different data is present. In this example, different data is an instance of one number being stored in one location, and a second, different number being stored in the other location. That is, for example, without limitation, only a single number is stored in each location, but those numbers are difference. Although not necessarily required, in this illustrative example, preference is given to the data taken from the wireless device in the event of a discrepancy, since it is assumed that this data is more likely to be the up to date data. In other words, if a different number is stored locally and remotely, the remote number is used to replace the local number 223 , instead of the other way around.
[0056] Once all the data has been parsed and considered, the process exits 229 . Once the process has exited, there may be a robust, complete, and up to date copy of the remote data stored locally, and any missing gaps in the remote data may have been filled in by stored local data. Also, it is possible that the system queries a user before replacing data in either storage location, so as not to overwrite desired data, or re-write or duplicate data that is no longer desired.
[0057] FIG. 3 shows an illustrative example of a process for data restoration. In this illustrative embodiment, the vehicle computing system connects to a mobile device 301 (phone, PDA, etc., although in this example the device is represented by a cellular phone). Initially, the system checks to see if the connection to the device was the result of a new pairing with the device 303 (e.g., the device has presumably not been paired with the system previously).
[0058] If the pairing is a new pairing, then it is likely that either a user has never used the system (e.g., a new user) or has obtained a new phone. Accordingly, when a new pairing is detected 303 , the system asks the user if the user wishes to tie the phone to a previously existing account (assuming at least one account exists in the system).
[0059] If the user wishes to use an existing account, then in this illustrative embodiment, the system asks the user for a PIN 311 (password, ID, etc.) in order to prevent unauthorized access to an account. The system loops until a proper PIN is entered (or a predefined number of times), checking the validity of the PIN 313 and notifying the user if the PIN was incorrect 315 .
[0060] Once a valid PIN is entered, the local account is associated with the device and the corresponding data may also be uploaded to the phone 317 (thus populating the phone book and/or email contacts, in this example, although applications and other backed-up data could also be loaded from the vehicle computing system storage). The system then exits 325 . It may also be possible to prompt the user for acceptance before the local data is uploaded to the device.
[0061] Further, it may be the case that some data already exists on the wireless device. In this instance, the system may perform a cross-check as in FIG. 2 before uploading the data, so as to accurately cross-populate the data, as opposed to simply overwriting the existing data on the device with the locally stored data associated with the account.
[0062] If the user elects not to use an existing account, then the system asks the user if the user would like to create a new account 319 . If the user elects to create an account, the system prompts the user to enter a PIN 321 or other protection code. The data from the wireless device (if any exists), is then downloaded and used to populate the local data associated with the account 323 .
[0063] FIG. 4A shows an illustrative example of a process for email address verification. In this illustrative embodiment, the vehicle computing system initiates (automatically or per user request) a check of email addresses (stored locally or downloaded from a wireless device) 401 .
[0064] Moving to a first email address 403 , the vehicle computing system first checks to see if there are any remaining addresses 405 (i.e., in this particular instance, if a first address in NULL, indicating no email addresses). If there is at least one email address, the vehicle computing system sends an email to the current email address 407 .
[0065] The email sent to the address can be in several forms. The vehicle computing system could access a user's email account and send an email through that account on behalf of the user. Alternatively, the system could have an email address associated therewith for system use, and use that email. Any suitable method of “testing” an email address may be used.
[0066] The system then advances to a next email address 409 , and continues to retrieve and “test” email addresses until no addresses remain for testing 405 .
[0067] If at least one email has been sent 410 (if no emails have been sent, e.g. no email addresses exist, or testing is done on a periodic basis for each address, and no addresses that have not been recently tested exist, etc.) the system waits for a predetermined amount of time 411 . In this embodiment, the predetermined amount of time is to allow for bounce-backs from invalid email addresses. If the system has an address associated therewith, this wait may not be implemented, but the delay helps ensure that adequate opportunity for rejection exists.
[0068] After the predetermined amount of time has passed 411 , the vehicle computing system checks the associated email account (from which the emails were sent) for responses indicating invalid email addresses 413 . In this illustrative embodiment, a list of “bounced” emails is accumulated 415 for parsing, although any suitable method of checking the emails may be implemented in accordance with the spirit of the invention.
[0069] If emails remain on the “bounced” list 417 , the system deletes the email address from local (or remote) storage corresponding to the email address that was bounced 419 . It may also be desirable to set a marker with respect to the deleted email, so that future cross-referencing with a wireless device does not result in re-population of the invalid email (assuming the device is not immediately updated). The system then advances to a next email on the bounced list, and continues to parse and delete email addresses until no bounced emails remain, at which point the system exits 423 .
[0070] FIG. 4B shows an illustrative example of a process for invalid email address automatic correction. In this illustrative embodiment, instead of simply deleting an email address, as denoted in step 419 of FIG. 4A , the vehicle computing system will attempt to determine a valid email address to replace the invalid one before deleting the invalid email address.
[0071] Once an email address has been determined to be invalid, the system checks to see if any social networking accounts are associated with the local user account storing the invalid email address (or the remote device storing the invalid email address) 431 . If no social networking accounts exist, then in this example, the address is deleted 421 . Additionally or alternatively, before deleting the email address, the vehicle computing system could send a reminder email to a valid user email address, notifying that user that a particular email address was deleted (in case the user can manually re-program a valid email address).
[0072] If one or more social networking accounts (e.g., without limitation, FACEBOOK, LINKEDIN, MYSPACE, etc.) exist that are associated with the user account and are accessible by the vehicle computing system (presumably, although not necessarily, through the use of a stored ID and password), the vehicle computing system contacts a first social networking account 433 . The system then checks to see if a contact corresponding to the contact for whom the email address is to be deleted exists within the user's social network 435 . This may require a correspondence between the stored user name and the chosen social networking name.
[0073] If no contact exists, the system checks to see if any unprocessed social networks remain 451 . If so, then the system selects a new account 453 and repeats the checking process, otherwise the system assumes that a replacement email address is not available in this manner and deletes the email address 421 .
[0074] If the contact does exist on a social network, the system then parses the account page of the contact to see if an email address is retrievable from that page 437 . If no email address is available, the system moves on to a next account (if any).
[0075] If an email address is available, however, the system checks to see if the email address listed on the social networking site corresponds to the email address that is about to be deleted 439 . If the email addresses are the same, then the system does not attempt to repopulate the email contact information stored with the user account with the known invalid email.
[0076] If a different email address is available over the social networking site, however, the system updates a local storage with that email address (since it knows the one it is overwriting is invalid) 441 and tests the new email address for validity 443 (possibly in the manner described with respect to FIG. 4A ).
[0077] If the test is successful (e.g., in this example, no bounce-back) 445 , the system stores the new email address as a valid email address (possibly updating the wireless device as well) and moves to a next email address 421 . If the test is not successful, the system may delete the new email address and check for additional social networking accounts from which a valid email address may be obtained 451 .
[0078] FIG. 5 shows an illustrative example of a process for cross account data maintenance. In this illustrative example, two accounts have agreed to share common data. For example, if a husband and wife have common numbers, and one of them updates a number, they may not remember to tell the other party that the number was updated. This illustrative embodiment would facilitate the automatic update of the number to the other party's device.
[0079] In this illustrative embodiment, the vehicle computing system connects to a wireless device 501 . Once the connection is established, the system checks to see if cross-account pairing is enabled for the connected device 503 . If pairing is not enabled, the system exits 509 .
[0080] If cross-account pairing is enabled, the system may compare data downloaded from the wireless device with the account (or accounts) to which the user is cross-paired 505 . In this illustrative example, only data that matches (e.g., where the contact data is the same for both accounts) is evaluated for updates (e.g., all user data may be checked, but updates are only performed on common contacts). It may also be possible, however, to compare all data for updates, and cross populate the accounts with any missing data (if the users wish to completely share all data).
[0081] In this example, the system accumulates all the matches between accounts during the comparison 505 , although the system could also perform the update process as the common contacts are established.
[0082] If one or more matches remain 507 , the system checks to see if there is a variance between data stored in the cross-paired account(s) and the current match 511 . If there is no variance, the system moves on to a next match 525 . If there is a discrepancy in the data 511 , the system checks to see if any additional data 513 exists with respect to the contact in one account that is not present in the other account. For example, one account may have a first phone number associated with the contact, and a second account may have a first and second phone number associated with the same contact. The additional data from the contact having the additional data is added to the contact lacking the data 515 .
[0083] If no additional data exists, or after additional data has been added, the system checks to see if different data exists. Note that, while the illustrative embodiment defines additional data as an instance where similar and additional data exists for a contact format (phone, email, etc), it is possible to have additional and different data. For example, a first account could have one phone number and one email address associated therewith, and a second account could have two phone numbers (one similar to the first contact's) and a different email address associated therewith. Thus, after the additional phone number had been cross-populated, the variance between email addresses may still need to be evaluated.
[0084] If different data exists 517 , the system then determines whether or not the data in one of the accounts should be replaced 519 . This could be done through a user query as to the correct data, by using an update date/time associated with each data element (since it may be likely that the more recently updated data is the accurate data, although not necessarily), or through any other suitable method.
[0085] If it is determined that the data in one of the accounts should be replaced, then the system adds the correct data to the account with the invalid or old data 521 and deletes the old data 523 . As this process occurs, it is possible that data from the presently connected device may be used to update the stored account of a non-connected but cross-linked user. Thus, when that user connects at a later date, the stored account data associated with that user may already be in an updated condition with respect to the cross-linked user's account.
[0086] A next data element is then examined 525 . Once all the data has been examined, and no matches remain, the system exits 509 .
[0087] FIGS. 6A and 6B show illustrative examples of processes for invalid phone number automatic correction.
[0088] In the illustrative process shown in FIG. 6A , a contact is identified as an invalid contact 601 (or rather, the phone number associated with the contact is invalid). This may be the result of a determination by the vehicle computing system (such as a rejected phone call) or it may be identified by the user as invalid.
[0089] If there are one or more social networks associated with the user account in which the invalid contact is stored 603 , the vehicle computing system logs in to at least a first of the social networks 605 . The system then searches contacts on the user's social network site, looking for a name match to the contact corresponding to the invalid phone number 615 .
[0090] If a match is found, the system checks to see if a phone number is saved with respect to that contact on the social networking site 619 . If a different number exists on the site, that number is assumed to be the correct number and is saved locally 621 . The process then exits 623 .
[0091] If no contact exists, or if there is no number or the same number, the system will check to see if access to any additional social networking sites is available.
[0092] If no social networking sites are available, or once all site options have been exhausted, the system checks to see if an email address is associated with the contact 607 . This email address may have also been obtained while the system was searching one or more social networking sites.
[0093] The vehicle computing system sends a request email to the email address 609 , requesting an updated phone number. This email may be sent from an account associated with the vehicle, a user account, etc.
[0094] The vehicle computing system then periodically checks the email account from which the email was sent for a response 611 (this may be a separately running process, since the response will likely take some time to obtain).
[0095] The process then exits 613
[0096] FIG. 6B shows an illustrative example of a process for checking for a response email. The process checks the email account 631 to see if a response has been received 633 . If the response has been received, the system checks the response to see if a valid response number has been included with the response 637 . If there is a valid response to the email, and if the response contains a valid number, then the vehicle computing system uses the number to update the contact 639 . This update can be done to locally saved data, data saved on the wireless device, or both.
[0097] Although the invention has been described in terms of illustrative embodiments, these examples are provided for illustrative purposes only, and are not intended to limit the scope of the invention in any manner.
[0098] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention. | A computer-implemented method includes downloading data elements from a wireless device. The method includes determining whether a user account exists in storage and determining whether the user account currently has stored data elements of the same type as the downloaded data elements associated therewith. The method further includes comparing the downloaded data elements to the stored data elements. This method also includes storing any downloaded data elements not currently existing in the data elements associated with the user account and not in conflict with data elements associated with the user account. The method further includes resolving conflicts between downloaded data elements and currently existing data elements, to establish which of the conflicting elements is representative of a proper version of the element. Finally, the method includes storing the proper version of the element resulting from each conflict resolution. | 6 |
CROSS-REFERENCES TO RELATED APPLICATIONS
This application claims priority from R.O.C. Patent Application No. 090110716, filed May 4, 2001, the entire disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates generally to semiconductor devices and, more particularly, to measuring the depth of a well in a semiconductor device or substrate.
The depth and shape of the boundary of a well affect the electrical properties of a power integrated circuit (IC), especially in R ds-on , the threshold voltage, and the drain-to-source breakdown voltage. Thus, monitoring the depth and shape of the boundary of a well is an important task.
Traditionally, the spreading resistance probe (SRP) is used to simulate the depth of a well. A well-skilled operator is needed, however, to prepare the sample prior to measurement with the probe. Moreover, the use of the probe for well measurement is time-consuming and expensive. If the width of the device region is smaller than 50 μm, this method cannot be used.
In another technique, the secondary ion mass spectroscopy (SIMS) is used to analyze the distribution of dopants in the device. If the width of the device region is smaller than 100 μm, however, such a method cannot be used.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed to an effective and relatively inexpensive way for measuring the depth of a well in a semiconductor device or substrate. In specific embodiments, the device having a well in a substrate is cut through the well, and different regions forming the well are selectively removed by an etchant to expose the boundary of the well. The depth of the well is measured by scanning electron microscopy (SEM) or other suitable techniques.
In accordance with an aspect of the present invention, a method for measuring the depth of a well of a substrate comprises providing a substrate having a well therein and a cut through a depth of the well. The substrate is exposed to an etchant to reveal a discontinuity in a boundary at the depth of the well. The depth of the well is measured at the boundary.
In some embodiments, the well is a p-type well and the substrate is an n-type substrate. In other embodiments, the well is an n-type well and the substrate is a p-type substrate. In some embodiments, the etchant may comprise nitric acid, hydrofluoric acid, saturated iodide, and deionized water. The iodide may be selected from the group consisting of potassium iodide (KI) and sodium iodide (NaI). In other embodiments, the etchant may comprise nitric acid, hydrofluoric acid, saturated iodine, and deionized water.
In specific embodiments, the substrate is dipped into the etchant to reveal the discontinuity in the boundary at the depth of the well. The etchant is at a temperature of about 20-30° C. The substrate is dipped in the etchant for about 10-50 seconds. The substrate is washed with deionized water after exposing the substrate to the etchant to reveal the discontinuity in the boundary at the depth of the well. The depth of the well may be measured by a scanning electron microscope.
Another aspect of the present invention is directed to a method for measuring a depth of a boundary between a first conducting doped region and a second conducting doped region. The method comprises using an etchant to selectively etch the first conducting doped region and the second conducting doped region to reveal a boundary therebetween. The etchant has a different selectivity between the first conducting doped region and the second conducting doped region. The method further comprises measuring the depth of the boundary between the first conducting doped region and the second conducting doped region.
In some embodiments, the boundary is a p-n boundary. The etch rate of the second conducting doped region is higher than the etch rate of the first conducting doped region. The first conducting doped region may be a p-doped region and the second conducting doped region may be an n-doped region.
Another aspect of the present invention is directed to a method for measuring the depth of a boundary between a first n-doped region with a first doped concentration and a second n-doped region with a second doped concentration which is different from the first doped concentration. The method comprises using an etchant to selectively etch the first n-doped region with the first doped concentration and the second n-doped region with the second doped concentration which is different from the first doped concentration to reveal a discontinuity at a boundary therebetween. The method further comprises measuring a depth of the boundary between the first n-doped region and the second n-doped region.
In accordance with another aspect of the present invention, an etchant having an etch rate of an n-doped region which is higher than an etch rate of a p-doped region comprises the following:
1 molar ratio of nitric acid;
0.01-0.05 molar ratio of hydrofluoric acid;
2 molar ratio of deionized water; and
0.001-0.003 molar ratio of iodide ions.
In some embodiments, the etchant has an etch rate of a first n-doped region having a first n-dopant concentration which is higher than an etch rate of a second n-doped region having a second n-dopant concentration, wherein the second n-dopant concentration is lower than the first n-dopant concentration.
In accordance with another aspect of the present invention, a method for measuring depths of boundaries comprises using an etchant to selectively etch a p-doped region, a first n-doped region having a first n-dopant concentration, and a second n-doped region having a second n-dopant concentration which is higher than the first n-dopant concentration, to reveal a first boundary between the p-doped region and the first n-doped region, and to reveal a second boundary between the first n-doped region and the second n-doped region. The etch rates are characterized as follows:
an etch rate of the second n-doped region>
an etch rate of the first n-doped region>
an etch rate of the p-doped region.
The method further comprises measuring a depth of the first boundary and a depth of the second boundary. The depths may be measured using a scanning electron microscope.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional schematic diagram of a substrate having a p-n boundary;
FIG. 2A is a cross-sectional schematic diagram of the right side of the cut substrate of FIG. 1 after cutting off the left side of the device along line I—I according to an embodiment of the present invention;
FIG. 2B is a cross-sectional schematic diagram of the right side of the cut substrate of FIG. 2A after etching according to an embodiment of the present invention;
FIG. 3 is a cross-sectional schematic diagram of a power IC;
FIG. 4A is a cross-sectional schematic diagram of the right side of the cut substrate of FIG. 3 after cutting off the left side of the device along line III—III according to an embodiment of the present invention; and
FIG. 4B is a cross-sectional schematic diagram of the right side of the cut substrate of FIG. 4A after etching according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a cross-sectional schematic diagram of a device or substrate 30 with a p-n boundary. The substrate 30 is typically a silicon substrate, and includes a p-doped region (p well) 36 and n-doped regions 32 , 34 with different concentrations of n dopants. In the embodiment shown, the concentration of the n-doped region 32 is higher than that of the n-doped region 34 . A p-n boundary 35 is formed between the p-doped region 36 and the n-doped region 34 . The n-doped region 32 and the n-doped region 34 are separated by a boundary 33 .
The substrate 30 is cut along the line I—I. FIG. 2A shows the right side of the substrate 30 after the cut. The right side of the cut substrate 30 is dipped into an etchant to selectively remove the n-doped regions 32 , 34 (by greater amounts than the p well 36 ) to reveal a discontinuity in the p-n boundary 35 between the p-doped region 36 and the n-doped region 34 , as illustrated in FIG. 2 B. The etchant has the characteristics that the etch rates of the n-doped regions 32 , 34 are faster than the etch rate of the p-doped region 36 . After achieving the desired etching, the depth and shape of the p-n boundary 35 in the treated substrate 30 can be measured using a scanning electron microscope (SEM) or other suitable techniques.
In the embodiment shown in FIGS. 1-2B, the etchant includes a selectivity ratio of n-doped region to p-doped region which is typically between about 1.3 and 1.8. A suitable etchant may comprise, for example nitric acid, hydrofluoric acid, iodine, and deionized water; or nitric acid, hydrofluoric acid, iodide, and deionized water. The iodide is saturated and can be, for example potassium iodide (KI) or sodium iodide (NaI). In a specific embodiment, the molar ratio of nitric acid to hydrofluoric acid to deionized water to iodide ion is about 1: (0.01-0.05): 2: (0.001-0.003). The temperature during etching is typically maintained at about 20-30° C. The processing time is typically about 10-50 seconds.
After selectively removing the n-doped regions 32 , 34 , the substrate is subjected to a wash with deionized water or the like to remove the residual of the etchant. The SEM is then used to measure the depth and shape of the boundary of the p well 36 .
In the embodiment shown, the etchant has a high selectivity for the n-doped region to the p well in the silicon substrate, so that the n-doped region can be removed faster than the p well region to facilitate measurement of the depth of the p well. Moreover, this technique can be used to measure the depth of an n well. In that case, the etchant can be selected to have a high selectivity for the n well to the p-doped region in the substrate.
The etchant can also be used to reveal the boundary 33 between the n-doped regions 32 , 34 which have different n dopant concentrations. This is possible because the etchant has a high etch rate for the n-doped region 32 with the higher concentration than for the n-doped region 34 with the lower concentration. After dipping the substrate 30 in the etchant, a discontinuity in the boundary 33 between the n-doped regions 32 , 34 is revealed, as illustrated in FIG. 2 B. The treated substrate 30 is washed with deionized water or the like, and the SEM is used to measure the depth of the boundary 33 between the n-doped regions 32 , 34 .
In a specific example, the difference in dosage between the n-doped regions 32 , 34 is over 100 times.
The following describes the difference in the etch rate for an etchant that comprises nitric acid, hydrofluoric acid, iodine or iodide, and deionized water. The etch rate for the higher concentration n-doped region 32 is greater than the etch rate for the lower concentration n-doped region 34 , which is greater than the etch rate for the p-doped region or p well 36 . This is achieved because the reacting rates between iodide ions and p-dopants (such as B+) and between iodide ions and n-dopants (such as P + ) are different. The reacting rate of iodide ions and P + ions (n-dopants) is faster than the reacting rate of iodide ions and B + ions (p-dopants). If the concentration of P + ions increases, the reacting rate of iodide ions and P + ions increases. The etching rate of B + ions or P + ions reacting with iodide ions is relative to the oxidizing rate of the corresponding matrix silicon atoms. The silicon atoms oxidize to form silicon oxide, and the silicon oxide is removed by hydrofluoric acid.
The above-described method can be applied to measure the depth of a well in various devices or substrates. In one example, the method is employed to measure the depth of the p well of a power IC as illustrated in FIGS. 3-4B. FIG. 3 shows the cross-sectional schematic diagram of the power IC substrate 10 , which includes an n + doped region 26 , an n − doped region 28 , and a p − well 12 . In a specific embodiment, the n + doped region 26 has a dosage of about 1E18 cm −2 -1E19 cm −2 ; the n − doped region 28 has a dosage of about 1E16 cm −2 -1E17 cm −2 ; and the p − well 12 has a dosage of about 7E13 cm −2 . A p-n boundary 13 is formed between the p − well 12 and the n − doped region 28 . The substrate 10 includes a trench 14 , a gate oxide layer 16 , a gate 18 , an n + source 20 , a BPSG layer 22 , and a p + region 24 . In a specific embodiment, the n + source 20 has a dosage of about 1E16 cm −2 ; and the p + region 24 has a dosage of about 5E14 cm −2 .
In this example, the etchant comprises 18 ml of 70% nitric acid, 2.2 ml of 49% hydrofluoric acid, 2 ml of deionized water, and 0.2 g potassium iodide. The power IC substrate 10 is cut along the line III—III, as shown in FIG. 4A, and then subjected to a dip in the etchant for 25 seconds. The etched substrate 10 is washed with deionized water. This procedure reveals a discontinuity in the p-n boundary 13 in the substrate 10 , as seen in FIG. 4 B. In addition, it reveals a discontinuity in the boundary 27 between the n + doped region 26 with the higher concentration and the n doped region 28 with the lower concentration.
The above-described arrangements of apparatus and methods are merely illustrative of applications of the principles of this invention and many other embodiments and modifications may be made without departing from the spirit and scope of the invention as defined in the claims. The scope of the invention should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents. | The present invention is directed to an effective and relatively inexpensive way to measuring the depth of a well in a semiconductor device. In accordance with an aspect of the present invention, a method for measuring the depth of a well of a substrate comprises providing a substrate having a well therein and a cut through a depth of the well. The substrate is exposed to an etchant to reveal a discontinuity in a boundary at the depth of the well. The depth of the well is measured at the boundary by scanning electron microscopy (SEM) or other suitable techniques. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to rotary machines and particularly to sealing of a medium flow path within the machine.
2. Description of the Prior Art
The design and construction of efficient rotary machines, and of gas turbine engines in particular, has historically required careful confinement of the working medium gases to the flow path of the machine to preserve aerodynamic performance and to protect the internal components of the machine from thermal degradation.
Typical construction details in a region radially inward of the working medium flow path of a gas turbine engine are shown in U.S. Pat. No. 3,515,112 to Pettengill entitled "Reduced Clearance Seal Construction." In a Pettengill type construction the radially inward ingestion of working medium gases into the internal regions of the machine is prevented by flowing air radially outward between the stator or stationary element and the rotor or rotating element of the machine. The air flowed outwardly is termed purge air and is supplied to the cavity at a pressure greater than the pressure of the local working medium gases in the flow path. The rate of flow of the purge air through the cavity is set by the minimized combination of pressure differential and flow area between the purge supply and the flow path. For example, if the minimized flow conditions in the Pettengill construction occur across the labyrinth seal, the rate of flow across the seal will establish the rate of flow through the cavity. Similarly, if the minimized conditions of pressure differential and area occur across the narrow passage between the relatively rotating components at the disk rim, the flow rate through the cavity will be restricted by the flow rate through the passage.
Within the cavity the purge air adjacent the rotating member is pumped radially outwardly in response to frictional forces between the air and the radially extending surfaces of the rotor. If the pumping rate exceeds the rate at which purge air is supplied through the labyrinth seal, a circulation zone is established within the cavity. The excess of pumped air over purge air is forced across the passage leading to the working medium flow path and radially inward along the stationary member. As the circulating air travels across the passage, a portion of the working medium gases is ingested and circulated with the cavity air. As this occurs, the temperature of the air within the cavity becomes elevated and the durability of the local components becomes adversely effected.
New concepts are continually sought within the rotary machinery art to minimize the performance losses inherently imposed upon the machine by flowing substantial amounts of purge air between the relatively rotating components to prevent ingestion of the working medium gases.
SUMMARY OF THE INVENTION
A primary aim of the present invention is to improve the operating efficiency of a gas turbine engine. Minimizing the amount of purge air required to prevent the ingestion of working medium gases into internally located cavities is one goal. In furtherance of the stated primary aim, a reduction in the radial outflow of air through various boundary layers is desired and, in one aspect, a specific object is to invert the radial pressure gradient conventionally imposed upon the boundary layer by internal pressure forces within the cavity. A concomitant aim is to increase the clearance between the rotating and the stationary elements of a rotary machine without adversely affecting performance or durability.
According to the present invention air within a cavity which is formed between a rotating element and a stationary element of a rotary machine is accelerated to a tangential velocity which approximates the tangential velocity of the rotating element at a corresponding radial position.
A primary feature of the present invention is the air injection nozzle which is oriented so as to discharge the air flowing therefrom in the direction of rotation of the rotating element. In one embodiment the nozzle is canted radially inward so as to impart an inward velocity component to the air flowing therethrough. Another feature of the present invention is the substantial clearance between the rotating element and the stationary element of the machine at the outer end of the cavity.
A principal advantage of the present inventon is increased cycle efficiency which results from a reduction in the amount of purge air which must be flowed through the cavity to prevent the ingestion of working medium gases. Additionally, the clearance between the rotating and stationary elements of a gas turbine engine in the region of the disk rim is increased to insure that destructive interference between the relatively rotating elements does not occur. The durability of the components adjacent to the cavity is increased through a reduction in the cavity temperature as the ingestion of medium gases is stopped.
The foregoing, and other objects, features and advantages of the present invention will become more apparent in the light of the following detailed description of the preferred embodiment thereof as shown in the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a simplified cross section view of the portion of the turbine section of a gas turbine engine;
FIG. 2 is a sectional view taken along the line 2--2 as shown in FIG. 1;
FIG. 3 is a graph showing the relationship between radius and the tangential velocity of the air within the central portion of the cavity; and
FIG. 4 is a graph showing the relationship between radius and the mass flow rate of air through the boundary layer adjacent the rotating element.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A gas turbine engine is typical of rotary machines in which the inventive concepts taught herein may be advantageously employed. A portion of the turbine section of such an engine is shown in FIG. 1. The stator assembly is formed of a cylindrical case 14 which has, extending radially inward therefrom, one or more rows of stator vanes 16. A diaphragm 18 extends radially inward from the vanes. The rotor assembly is comprised of at least one disk 20 which has, extending radially outward therefrom, a row of rotor blades 22. A side surface 24 of the disk opposes but is spaced apart from the diaphragm 18. A cavity 26 is formed between the side surface and the diaphragm. A labyrinth seal 28 closes the radially inward end of the cavity. The rows of blades and vanes are alternatingly disposed across an annular flow path 30 which radially bounds the outward end of the cavity 26. A passage 32 extends between the cavity and the flow path. The flow path 30 carries the working medium gases which include products of combustion from a combustion chamber 34 axially downstream through the engine. A plurality of nozzles 36, which are more graphically viewable in FIG. 2, are circumferentially spaced about the passage 32. Relatively cool air is flowable to the nozzles from the compression section of the engine through conduit means 38. Each nozzle has a 90° bend in the direction of rotation of the rotor assembly.
During operation of the engine air is flowed through the nozzles 36 and discharged tangentially in the direction of rotor rotation to cause the air within the cavity 26 to swirl. In the ideal condition the swirling air is accelerated to a tangential velocity which is equal to the tangential velocity of the disk side surface 24 at a corresponding radial location. Operation under the ideal condition, as is discussed below, prevents the radial outflow of air through the disk boundary layer.
As is discussed in the prior art section of the application, relatively cool air is conventionally flowed through the cavity 26 to purge the cavity of hot medium gases. The mass rate of flow of purge air must exceed the mass rate of flow of air pumped radially through the disk boundary layer in order to substantially eliminate ingestion. Advantageously in the present construction, the amount of purge air required to prevent ingestion is reduced through the judicious use of the purge air to decrease the mass flow rate of air pumped through the boundary layer.
A reduction in the boundary layer mass flow rate is achieved by altering the net sum of the radial florces acting upon each particle in the boundary layer. Free vortex and forced vortex phenomenon are employed to effect this reduction.
In a free vortex flow field, which is characteristic of the air in the central region of the cavity 26, the radial pressure gradient is equal in magnitude and opposite in direction to the radial acceleration acting upon each particle.
(dP/dr) = ρ a.sub.R
where
ρ is the density of air;
(dP/dr) is the radial pressure gradient; and
a R is the radial acceleration.
The radial acceleration is expressible in terms of the tangential velocity and radius,
a.sub.R = (V.sub.T.sup.2 /r)
Where
V T is the tangential velocity of the air; and
r is the radius from the center of rotation to the local region.
Equating the radial pressure gradient in the center of the cavity to the radial acceleration, the gradient becomes expressible in terms of the local tangential velocity of the air.
(dP/dr) = ρ (V.sub.T.sup.2 /r
The radial pressure gradient in the central portion of the cavity (dP/dr) is imposed laterally upon the boundary layer adjacent the side surface 24. In contrast to the air in the central portion of the cavity, however, the air in the boundary layer is subjected to forced vortex phenomenon. In forced vortex fields the tangential velocity of the air is equal to the tangential velocity of the adjacent structure.
V.sub.T = wr
Where
w is the angular velocity of the adjacent structure.
Summing the radial forces on a particle in the boundary layer, the net radial force is shown below:
F = a.sub.R - (1/ρ dP/dr) = ((wr).sup.2 /r ) - ((V.sub.T).sup.2 /r
Where
F is the net radial force per unit mass on a particle within the boundary layer.
According to the concepts taught herein, air within the cavity is accelerated to a tangential velocity (V T ), which is equal to the local tangential velocity (wr) of the side surface 24 by flowing purge air through the nozzles 36. Resultantly, the net radial force in the local region of the boundary layer becomes 0 and the radial outflow of air ceases.
Cessation of the radial outflow in the vicinity of the passage 32 eliminates recirculation patterns which conventionally cause a portion of the working medium gases to be ingested into the cavity and allows a corresponding reduction in the amount of purge air required to oppose ingeston. In one embodiment the radial clearance between the relatively rotating components of the labyrinth seal is reduced to diminish the supply of purge air, although a small amount of air is continually flowed to limit the temperature of the air within the cavity.
As is viewable in the FIG. 2 embodiment, each of the nozzles is canted radially inward approximately 15° from a tangent line. The canted geometry reduces aerodynamic perturbations caused by the back of the adjacent nozzle. Canting the nozzles axially rearwardly with respect to the engine axis may produce a similar benefit. The essential feature of each nozzle, however, remains the ability of the nozzle to impart tangential swirl to air within the cavity. Further, any device capable of producing the tangential swirl described herein is substitutable for the nozzles of the preferred embodiment shown.
Although the invention has been shown and described with respect to a preferred embodiment 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 the scope of the invention. | A rotary machine, such as a gas turbine engine, capable of reliable operation with improved overall cycle efficiency is disclosed. Various construction details which aerodynamically isolate internal cavities of the machine from the flow path for the working medium gases are developed. A sealing system built around the use of free vortex phenomenon reduces the amount of air which must be flowed through the cavity to prevent ingestion of the working medium gases into the cavity. | 5 |
RELATED APPLICATION DATA
[0001] This application claims priority of U.S. Provisional Application No. 61/979,291 filed on Apr. 14, 2013, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to hydrostatic transmissions, and more particularly to pump control systems for hydrostatic transmissions.
BACKGROUND
[0003] Hydrostatic transmissions are well known and generally include a hydraulic pump and a hydraulic motor. The hydraulic pump and the hydraulic motor may be arranged as separate components or may be combined together in an integral unit. Axial swashplate type hydraulic piston pumps are frequently used in many such hydrostatic transmissions. Such pumps generate a pump action by causing pistons to reciprocate within a piston bore, with reciprocation of the pistons being caused by a swashplate that the pistons act against as a cylinder barrel containing the pistons rotates. Pump fluid output flow or displacement for each revolution of the barrel depends on the bore size and the piston stroke as well as the number of pistons that are utilized. The swashplate can pivot about a swashplate pivot center or axis, and the swashplate pivot angle determines the length of the piston stroke. By changing the swashplate angle, the pump displacement can be changed as is known in the art.
[0004] With the swashplate at its extreme pivot angle relative to the axis of rotation of the barrel, a maximum fluid displacement is achieved. When the swashplate is centered at a right angle relative to the axis of rotation of the barrel, the pistons will not reciprocate and the displacement of the pump will be substantially zero. In some axial swashplate type piston pump designs, the swashplate has the capability of crossing over center which results in the pump displacement being generated at opposite ports. In an over center swashplate axial piston pump, each system port can be either an inlet or an outlet port depending on the pivot angle of the swashplate. Over center axial swashplate piston pumps are widely used in hydrostatic transmissions, to provide driving in both forward and reverse directions.
[0005] One use for hydrostatic transmissions is zero turn vehicles such as zero turn lawn mowers. A separate over center swashplate axial piston pump may drive a hydraulic motor and wheel on each side of the vehicle. When the swash plate angles of the two pumps are equal and the output flow rotates the wheels in the same direction at the same speed, the vehicle travels in a substantially straight line path in either the forward or the reverse direction. When the swash plate angles of the two pumps are not equal and the output flow rotates the wheels in the same direction but at different speeds, the output flow rotates one wheel faster than the other so that the vehicle will turn. When one of the pumps is rotating its associated wheel in one direction and the other pump is rotating its associated wheel in the other direction, the vehicle will make a zero radius turn. An operator interface allows the vehicle operator to control the swashplate angles of the separate over center swashplate axial piston pumps, to control straight line or turning or zero radius turns for the vehicle.
SUMMARY OF INVENTION
[0006] The present disclosure provides a system and method for controlling a hydraulic pump system. A swashplate type axial piston hydraulic pump may have a swashplate tiltable about a swashplate tilt axis, a barrel with axial pistons disposed in the barrel, the barrel and pistons being rotatable about a barrel rotation axis relative to the swashplate, the pistons each being moveable relative to the barrel along a straight line piston path, and the pistons having a stroke determined by the position of the swashplate. A fluid-powered actuator may be drivingly connected to the swashplate for displacing the swashplate about the swashplate tilt axis in response to fluid power provided thereto. An electrical controller may generate electrical command signals in response to controller inputs, and communicate such control signals to a fluid power control device. The fluid power control device is responsive to the control signals to vary fluid power provided to the actuator and thus change a tilt angle of the swashplate.
[0007] According to one aspect of the invention, a pump control system includes: a pump including a swash plate tiltable about a swashplate tilt axis, wherein rotation of the swashplate changes the title angle and effects a change in volumetric displacement of the pump; an actuator drivingly coupled to the swashplate, the actuator operative to displace the swashplate about the tilt axis to change the volumetric displacement of the pump; and a fluid power control device operative to vary fluid power provided to the actuator in response to a control signal; and a controller operatively coupled to the fluid power control device, the controller configured to generate the control signal to modulate the fluid power provided by the fluid power control device to the actuator to effect rotation of the swashplate.
[0008] According to one aspect of the invention, the system includes an input device operatively coupled to the controller, the input device operative to provide an input command corresponding to an output characteristic of a hydrostatic transmission, wherein the controller is configured to control an angular orientation of the swashplate based on the input command.
[0009] According to one aspect of the invention, the system includes a sensor communicatively coupled to the controller, the sensor operative to detect an angular position of the swashplate and to provide the detected angular position to the controller.
[0010] According to one aspect of the invention, the controller is configured to effect rotation of the swashplate independent of a user supplied command.
[0011] According to one aspect of the invention, the fluid power control device comprises an electronically-operated valve.
[0012] According to one aspect of the invention, the electronically-operated valve comprises a pressure control valve.
[0013] According to one aspect of the invention, the actuator comprises a hydraulic actuator.
[0014] According to one aspect of the invention, the hydraulic actuator comprises a linear actuator or a rotary actuator.
[0015] According to one aspect of the invention, the actuator is directly coupled to the swashplate.
[0016] According to one aspect of the invention, the actuator is indirectly coupled to the swashplate.
[0017] According to one aspect of the invention, the actuator comprises a ball-screw actuator.
[0018] According to one aspect of the invention, the system includes a prime-mover coupled to the pump and operative to provide mechanical power to the pump module.
[0019] According to one aspect of the invention, the system includes a hydrostatic transmission.
[0020] According to one aspect of the invention, a zero-turn lawn mower includes a prime mover, and a hydrostatic transmission having a swashplate control system as described herein.
[0021] According to one aspect of the invention, the system includes a method for controlling volumetric displacement of a hydraulic pump having a swash plate tiltable about a swashplate tilt axis, wherein rotation of the swashplate changes the title angle and effects a change in volumetric displacement of the pump. An actuator is drivingly coupled to the swashplate, the actuator operative to displace the swashplate about the tilt axis to change the volumetric displacement of the pump. The method includes using an electronic controller to modulating hydraulic power provided to the actuator to effect rotation of the swashplate.
[0022] According to one aspect of the invention, modulating hydraulic power includes using a fluid power control device to modulate fluid power to the actuator.
[0023] According to one aspect of the invention, the method includes: receiving at the controller a user-initiated command corresponding to an output characteristic of the hydrostatic transmission; and controlling an angular orientation of the swashplate based on the user-initiated command.
[0024] According to one aspect of the invention, the method includes: receiving at the controller position data corresponding to an angular orientation of the swashplate; and controlling an angular orientation of the swashplate based on the position data.
[0025] According to one aspect of the invention, using the electronic controller to modulate hydraulic power provided to the actuator includes modulating pressure independent of a user supplied command.
[0026] The foregoing and other features of the invention are hereinafter described in greater detail with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a perspective view of an exemplary zero-turn-radius mower employing a hydrostatic transmission to which the principles of the invention can be applied, as discussed below.
[0028] FIG. 2 is a block diagram of an exemplary control system in accordance with aspects of the present invention.
[0029] FIG. 3 is a schematic diagram of an exemplary control system in accordance with an embodiment of the present invention.
[0030] FIG. 4 is a schematic diagram illustrating a fluid-powered rotary actuator that may be used in a control system in accordance with the present invention.
[0031] FIG. 5 is a schematic diagram of another exemplary control system in accordance with an embodiment of the present invention.
[0032] FIG. 6 is a block diagram illustrating an exemplary regulator that can be used to control swashplate position in accordance with the present invention.
[0033] FIG. 7 is a perspective view of certain components of an exemplary pump that may be used in accordance with the present invention.
[0034] FIG. 8 is an enlarged perspective view of certain other components of an exemplary pump that may be used in accordance with the present invention.
DETAILED DESCRIPTION
[0035] Aspects of the present invention will now be described in the context of a hydrostatic transmission of a zero-turn-radius mower. It should be appreciated, however, that aspects of the invention are applicable to other applications in which a hydrostatic transmission is utilized.
[0036] Referring now to the drawings in detail, and initially to FIG. 1 , an exemplary zero-turn-radius mower 10 is illustrated. It is noted that the design of the illustrated mower 10 is merely exemplary in nature, and it will be appreciated that other mower designs and vehicle types can be used in accordance with the invention.
[0037] The mower 10 includes a frame 12 , a mower deck 14 supported by the frame 12 for mowing grass, an operator seat 16 , and a plurality of controls 18 for operating the mower 10 . A rear mounted engine attached to the frame 12 behind the seat 16 provides power to left and right hydrostatic transmissions also mounted to the frame 12 (the engine and hydrostatic transmissions are not shown in FIG. 1 ). As will be described in more detail below, each hydrostatic transmission includes a hydraulic pump having a swashplate, the swashplate operative to vary a volumetric displacement of the respective hydraulic pump.
[0038] A controller 20 is attached to the frame 12 and preferably located in an enclosure or other protected area. In the embodiment shown in FIG. 1 the controller 20 is located under the seat 16 , although other locations are contemplated. As will be described in more detail below, the controller 20 is operatively coupled to the plurality of controls 18 and to the swashplate of each hydrostatic transmission. Based on commands received from the controls 18 , the controller 20 can control the hydrostatic transmissions to independently drive respective rear wheels 22 to propel the mower and provide zero-turn-radius functionality.
[0039] With reference to FIG. 2 , a block diagram is provided illustrating the general architecture of a control system 30 in accordance with the present invention. More specifically, the system 30 includes the aforementioned controller 20 , which can include a processor for executing instructions and a storage device, such as memory, for storing instructions executable by the processor. Alternatively, the controller 20 may be in the form of a dedicated circuit, such as an application-specific integrated circuit (ASIC) or other custom circuit.
[0040] The controller 20 is operatively coupled to a user interface module 32 (also referred to as an input device) to receive inputs for operating the mower 10 . Generally, the user interface module 32 converts operator commands into signals that can be read by the controller 20 . Thus, for example, the user interface module 32 can include the plurality of operator controls 18 and sensing devices operatively coupled thereto, the sensing devices operative to convert, for example, linear or rotary motion into signals readable by the controller 20 (e.g., analog voltage or current signals, digital signals, etc.). The signals provided to the controller 20 may correspond to a desired output characteristic of the hydrostatic transmission (e.g., speed, power, torque, swashplate position, etc.).
[0041] Exemplary operator controls include a steering wheel, pedals, lap bars, joysticks and the like, while exemplary sensors include potentiometers, encoders, resolvers, and the like. The operator controls 18 may also include devices that provide binary on/off data, e.g., selector switches, pushbuttons and the like. Based on data received by the controller 20 from the user interface module 32 , the controller 20 generates a control signal for regulating a position of a swashplate of the hydrostatic transmission.
[0042] A power module 34 provides fluid or electric power to the system. In some embodiments the power module 34 may be fluid power provided by a pump (e.g., pneumatic or hydraulic power). In other embodiments the power module 34 may provide electric power. Power provided by the power module 34 is provided to a regulator module 36 .
[0043] The regulator module 36 receives the power provided from the power module 34 and the control signal from the controller 20 . Based on the control signal from the controller 20 , the regulator module 36 modulates the power (e.g., pressure or voltage) at its output and provides the modulated power to an actuator module 38 . The actuator module 38 includes an actuator, such as a pneumatic, hydraulic or electric actuator, which may be in the form of a linear or rotary actuator. Modulation of the power provided to the actuator module 38 produces a desired displacement of the actuator.
[0044] A pump module 40 includes a hydraulic pump having a rotatable swashplate to vary displacement of the pump, the swashplate being operatively coupled to the actuator of the actuator module 38 . By virtue of the coupling between the actuator and the swashplate, displacement of the actuator also effects angular displacement of the swashplate.
[0045] Accordingly, pump displacement (and thus power output by each hydrostatic transmission) is electronically controlled by the controller 20 . Such control by the controller 20 is advantageous in that it enables rotation of the swashplate independent of a user-supplied command. Independent control can be useful for implementing custom control modes for the mower 10 , such as cruise control, optimal implement speed control, four-wheel steering control, etc.
[0046] With additional reference to FIG. 3 , a schematic representation of a control system 50 in accordance with FIG. 2 is shown for a system using hydraulically actuated swashplate. While a hydraulic system is illustrated in FIG. 3 , it should be appreciated that other types of fluid power may be utilized without departing from the scope of the invention. For example, instead of hydraulic power the system may utilize pneumatic power.
[0047] As shown in FIG. 3 a hydrostatic transmission 52 includes a variable displacement hydraulic pump 54 for generating hydraulic power used by the hydrostatic transmission 52 . The hydraulic pump 54 may be driven by a prime mover 56 , such as an internal combustion engine, an electric motor or the like via drive system 58 (e.g., belt drive, chain drive, gear drive, etc.). Hydraulic power generated by the pump 54 is provided to a hydraulic motor 60 of the hydrostatic transmission 52 via ports, conduits and/or lines (not shown) within the hydrostatic transmission 52 . The hydraulic motor 60 converts the hydraulic power received from the pump 54 into rotational power, which is provided at the output shaft 62 for driving wheels 22 .
[0048] The hydraulic pump 54 includes a rotatable swashplate 64 , where variation of the angular position of the swashplate 64 varies its tilt angle and thus displacement of the pump 54 (e.g., between a minimum displacement (e.g., approximately 0%) and a maximum displacement (e.g., 100%)). An angle sensor 66 monitors the swashplate 64 to detect an angular position of the swashplate 64 . The sensor 66 may be in the form of an encoder, a resolver, or other suitable sensor for detecting angular position or displacement. The sensor may directly monitor position of the swashplate 66 , or indirectly monitor the position of the swashplate (e.g., via a trunnion shaft).
[0049] Operatively coupled to the swashplate 64 are first and second hydraulic cylinders 68 and 70 . The cylinders 68 and 70 may be indirectly coupled to the swashplate 64 . For example, the swashplate 64 may include a trunnion shaft 73 that effects rotation of the swashplate, the trunnion shaft being coupled to the cylinders 68 and 70 via arms 68 a and 70 a . Alternatively, the cylinders 68 and 70 may be directly coupled to the swashplate 64 . Linear displacement of the first cylinder 68 effects rotation of the swashplate 64 in a first direction, and linear displacement of the second cylinder 70 effects rotation of the swashplate 64 in a second direction opposite from the first direction.
[0050] The first and second cylinders 68 and 70 are in fluid communication with first and second fluid power control devices 72 and 74 , respectively. First and second fluid power control devices 72 and 74 , which in the present example are two-way valves, receive hydraulic power from a hydraulic power source 76 , such as a fixed-displacement pump driven by the prime mover 56 . While the exemplary embodiment utilizes two-way valves, other devices may be used, e.g., three-way valves.
[0051] While linear actuators are described in the present embodiment, other types of actuators may be used without departing from the scope of the invention. For example, instead of linear actuators, rotary actuators may be utilized. Briefly, FIG. 4 illustrates use of rotary actuators in a hydraulic system. The system is similar to the hydraulic portion of FIG. 3 , except the first and second actuators 68 and 70 are replaced with a rotary hydraulic actuator 67 . In response to hydraulic power provided by the fluid power control devices 72 and 74 to the rotary actuator 67 , rotation of an output shaft 67 a in a forward or reverse direction is achieved. The output shaft 67 a may be directly coupled to the trunnion shaft 73 of the swashplate 64 , or optionally a gearbox 67 b may be arranged between the output shaft 67 a and the trunnion shaft 73 .
[0052] Additionally, while not shown in FIG. 3 the system can include an adjustment device to set a neutral position for the hydraulic actuators. The adjustment device is manipulated during a calibration procedure to return the cylinders 68 and 70 (or rotary actuator 67 ) to a neutral position and remain in that position during power loss.
[0053] The controller 20 includes one or more outputs for providing control signals, status signals, etc. to other devices, such as the fluid power control devices 72 and 74 . For example, first and second outputs 78 and 80 of the controller are operatively coupled to the first and second fluid power control devices 72 and 74 , respectively, to provide first and second control signals (e.g., analog signals such as 0-10 VDC or 4-20 mA signals) to the respective fluid power control devices 72 and 74 that are proportional to a desired fluid flow through the fluid power control devices, or proportional to a desired fluid pressure at the output of the fluid power control devices. In this regard, 0 VDC (or 4 mA) may correspond to no fluid flow or no pressure, while 10 VDC (or 20 mA) may correspond to 100% fluid flow or 100% pressure. In this manner, the controller 20 can control the delivery of fluid power to the actuators 68 and 70 . While analog signals are described in the present example, other signal types may be utilized without departing from the scope of the invention. For example, instead of using outputs embodied as analog outputs, control signals may be communicated to the valves 72 and 74 (or other devices) via a communication bus (e.g., a network). The controller may include additional outputs that may be used by the system, such as wheel speed reference signals, implement speed reference signals, or any other parameter that may be controlled by the controller 20 . Such outputs may be used to provide enhanced control functions.
[0054] The controller 20 includes one or more inputs for receiving data from other devices, such as the operator controls 18 . For example, the controller 20 includes a first input 82 for receiving an input command from a user-operated device, such as a speed command, a power command, a direction command, etc. For sake of clarity only one input is shown for the operator controls. It will be appreciated, however, that the controller 20 may have a plurality of inputs as needed for the respective operator controls. As discussed above, the user operated device may be coupled to a sensor 86 so as to convert linear or rotary motion into a signal readable by the controller 20 . The controller 20 also includes a second input 84 communicatively coupled to the angle sensor 66 for receiving data corresponding to an angular position of the swashplate 64 . The controller 20 may optionally include other inputs for detecting various parameters, such as, for example, power take off engaged/disengaged, prime mover speed, implement speed, wheel speed, or any other parameter that may be used by the controller 20 . The inputs may be analog inputs (e.g., 0-10 VDC, 4-20 mA, etc.), digital inputs, optical inputs, networks, or other conventional means for providing data to the controller 20 .
[0055] Referring to FIG. 5 , another embodiment of a control system 50 ′ in accordance with the present invention is illustrated. The system 50 ′ is similar to the system 50 of FIG. 3 , except that electrically-operated actuators are used instead of hydraulically operated actuators. More particularly, the hydrostatic transmission 52 and its subcomponents (hydraulic pump 54 and swashplate 64 , hydraulic motor 60 ), the prime mover 56 , drive system 58 , angle sensor 66 , controller 20 and associated I/O are the same as those in the system of FIG. 3 . Therefore, discussion of these components will be omitted for FIG. 5 .
[0056] The system 50 ′ includes first and second electrically-operated actuators 69 and 71 operatively coupled to the swashplate 64 . Stepper motors, servo motors, shape memory alloys and piezoelectric actuators are examples of electrically-operated actuators that may be used in accordance with the present invention. The electrically-operated actuators 69 and 71 may be indirectly coupled to the swashplate 64 . For example, the swashplate 64 may include a trunnion shaft 73 that effects rotation of the swashplate 64 , and the trunnion shaft may be coupled to the electrically-operated actuators 69 and 71 via arms 68 a and 70 a . Alternatively, the electrically-operated actuators 69 and 71 may be directly coupled to the swashplate 64 . Linear displacement of the first electrically-operated actuator 69 effects rotation of the swashplate 64 in a first direction, and linear displacement of the second electrically-operated actuator 71 effects rotation of the swashplate 64 in a second direction opposite from the first direction.
[0057] While linear electrically-operated actuators are described in the present embodiment, other types of electrically-operated actuators may be used without departing from the scope of the invention. For example, instead of linear actuators, rotary actuators may be utilized. In one embodiment, the linear actuator is a motor-driven ball-screw arrangement.
[0058] The electrically-operated actuators 69 and 71 receive power from an electrical power source 77 . The electrical power source 77 , for example, may be an alternator or generator driven by the prime mover 56 . Alternatively, the electrical power source 77 may be a battery.
[0059] The electrically-operated actuators 69 and 71 are operatively coupled to the controller 20 via outputs 78 and 80 . The outputs may be analog outputs that provide a voltage or current control signal as described with respect to the embodiment of FIG. 3 , a communication network that provides digital control signals to the actuators, or any other means for communicating the control signals to the actuators 69 and 71 . Based on the control signals, the electrically operated actuators 69 and 71 rotate the swashplate 64 into any one of a number of different positions, and may be considered infinitely variable.
[0060] Regardless of the form of the actuators (i.e., hydraulic or electric), the controller 20 includes logic configured to position the swashplate 64 so as to produce a desired characteristic from the hydrostatic transmission 52 (e.g., output power, output speed, output torque, etc.). The logic may be stored in memory of the controller 20 and executable by a processor of the controller 20 . The logic stored in the controller 20 may be configured to control the position of the swashplate 64 based on a user-command provided by the plurality of controls 18 . For example, the plurality of user-operated controls 18 , such as a foot-operated pedal, a hand-operated lever, or the like can be operatively coupled to a respective sensor 86 to provide a signal corresponding to displacement of the pedal or lever (or other device). The signal generated by the sensor 86 can be provided to the controller 20 via the first input 82 . The controller 20 can equate a low end of the signal range (e.g., 0 VDC, 4 mA) to a first angular position of the swashplate 64 corresponding to minimum pump displacement, and a high end of the signal range (e.g., 10 VDC, 20 mA) to a second angular position of the swashplate 64 corresponding to a maximum pump displacement. The user-input signal may be filtered and scaled as is conventional.
[0061] The logic executed by the controller 20 may include a position regulator for controlling a position of the swashplate 64 . In this regard, the signal generated from the sensor 86 can be a “reference” position for the swashplate 64 , and the signal provided by the angle sensor 66 can be the “actual” position of the swashplate 64 . Based on a difference between the reference position and the actual position, the position regulator may generate a control signal, which may be filtered and scaled as is conventional. The control signal may be provided to one of the fluid power control device 72 and 74 (or to the electrically-operated actuators 69 and 71 ) via the outputs 78 and 80 of the controller 20 . In response to the control signal, the fluid power control devices 72 or 74 will alter the fluid flow and/or fluid pressure provided to the actuators 68 or 70 , thereby causing actuator displacement and effecting rotation of the swashplate 64 . Alternatively, in response to the control signal the electrically-operated actuators 69 and 71 will utilize the electrical power from the power source 77 to produce actuator displacement, thus effecting rotation of the swashplate 64 .
[0062] With reference to FIG. 6 , an exemplary position regulator 100 is illustrated in block form, the position regulator 100 being executable by the controller 20 to control an angular orientation of the swashplate 64 . Beginning at block 102 , the controller 20 receives the user input signal for controlling a feature of the hydrostatic transmission, e.g., output velocity. The user input signal may be a signal obtained from the user interface module 32 . For example, and as described herein, the user may manipulate an operator control 18 , which in turn causes a sensor 86 coupled to the operator control 18 to generate a signal. The signal, which may be an analog signal, a digital signal, an optical signal or any other signal readable by the controller 20 , preferably is proportional displacement of the respective operator control. The generated signal is read by the controller 20 via an input module corresponding to the type of signal (e.g., an analog voltage signal would be input via an analog voltage input). Next at block 104 the user input signal is optionally scaled and filtered to produce a signal corresponding to the regulated parameter. In the example shown in FIG. 6 , the user input signal may be scaled to correspond to the feedback device coupled to the swashplate (i.e., sensor 66 ). In this regard, the user input signal could be scaled to correspond to swashplate angular orientation. Based on such scaling, the output of block 104 is a position reference signal and is provided to a positive input of summing junction 106 .
[0063] As described herein, an angular position of the swashplate 64 is detected by sensor 66 and is provided to the controller 20 at block 108 . The sensor signal may be analog, digital, optical or any other signal type readable by the controller 20 . Next at block 110 , the position feedback signal is optionally scaled and filtered to correspond to the position reference signal, and the position feedback signal then is provided to a negative input of summing junction 106 . The output of the summing junction is an error signal indicative of the error between the desired position of the swashplate 64 and the actual position of the swashplate 64 . The error signal is provided to an input of controller 112 , which is shown as a proportional-plus-integral-plus-derivative (PID) controller, although other controllers may be used (e.g., a proportional controller, a proportional-plus-integral controller, etc.).
[0064] Based on the error signal the controller 112 generates a control signal, which is output by the controller at block 114 and provided to the actuator (e.g., to one of the fluid power control devices 68 or 70 in FIG. 3 or to one of the electrical actuators 69 and 71 in FIG. 5 ). In response to the control signal, displacement of the actuator and thus of the swashplate 64 is effected.
[0065] While the exemplary embodiment is described in the context of a position regulator, it should be appreciated that other regulation schemes may be employed without departing from the scope of the invention. For example, a speed regulator, torque regulator, power regulator, etc. may be used instead of or in conjunction with the position regulator.
[0066] Referring now to FIGS. 7-8 , each hydrostatic transmission 52 includes a conventional over center swashplate type axial piston hydraulic pump 54 . Pump 54 includes an input 120 that is drivingly connected to prime mover 56 to rotate a conventional pump barrel 122 . A plurality of axial pistons 124 are disposed within the pump barrel 122 and rotate with the pump barrel 122 about a barrel axis 126 . Pump 54 also includes a conventional over center swashplate 64 which is tiltable about a swashplate tilt axis 128 . The pistons 124 are each moveable relative to the barrel along a straight line piston path 130 that is substantially parallel to the barrel rotation axis 126 , and the pistons 124 have a stroke determined by the position of the swashplate 64 . When the swashplate 64 is in a neutral or center position perpendicular to the barrel axis 126 , the stroke of the pistons 124 is substantially zero and the output fluid flow displacement from the pump 54 is substantially zero. When the swashplate 64 begins to be displaced or titled in either direction about its tilt axis 128 , the stroke of pistons 124 begins to increase and output fluid flow displacement from the pump 54 begins. As the tilt angle of the swashplate 64 increases, the stroke of pistons 124 increases and the output fluid flow displacement from the pump 54 increases in a known manner. The output fluid flow displacement from pump 54 will be in one direction when the swashplate 64 is tilted in one direction from its neutral position and will be in the other direction when the swashplate 64 is tilted in the opposite direction. The output fluid flow from each pump 54 of each hydrostatic transmission flows through conduits (not shown) to a hydraulic motor 60 ( FIG. 3 ) of each hydrostatic transmission 52 , and such output flow rotates its associated hydraulic motor 60 to rotate its associated wheel 22 in the forward or reverse direction in a known manner. A reservoir 132 provides hydraulic fluid to the pump 54 , and a lever 134 opens and closes a fluid by-pass route (not shown) to enable pushing vehicle 10 when required.
[0067] Although the invention has been shown and described with respect to a certain embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described elements (components, assemblies, devices, compositions, etc.), the terms (including a reference to a “means”) used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application. | A hydrostatic transmission system includes a pump including a rotatable swash plate, wherein rotation of the swashplate effects a change in volumetric displacement of the pump. An actuator is coupled to the swashplate, the actuator operative to effect rotation of the swashplate to change the volumetric displacement of the pump. An electronic controller is operatively coupled to the actuator, the electronic controller configured to command the actuator to effect rotation of the swashplate. | 5 |
RELATED APPLICATIONS
This application is related to and claims the benefit of co-pending provisional application serial No. 60/100,535 filed on Sep. 9, 1998 entitled ANGLE OF ATTACK DETECTION AND INDICATION SYSTEM.
FIELD OF THE INVENTION
The present invention relates to detection of the angle of attack of an airfoil moving through the air and is particularly useful in piloting of aircraft, including light aircraft.
BACKGROUND OF THE INVENTION
The flying of an aircraft is dependent on the generation of lift resulting from the movement of an airfoil through the air. The generation of lift results when the angle of the chord line of the airfoil relative to the apparent wind is within a relatively small range of angles, the acceptable range of angles of attack. As shown in FIG. 1, the angle of attack is defined as the angle between the airfoil chord line and the relative wind direction. The chord line is defined as the line that connects the trailing edge (A) of the wing with the center curvature (B) of the wing. This range of angles varies considerably from one airfoil design to another, but even so, is ordinarily not significantly higher than about 18 degrees for light aircraft. When the angle of attack exceeds its upper limit, air separates from the upper surface of the airfoil (wing) and results in a decrease in lift. This loss of lift, or stall, is generally associated with an inability of the wing to support the aircraft.
It is a well known safety feature of light aircraft to detect and inform the pilot of an excessive angle of attack because this is the primary indicator of conditions that accompany a stall, or loss of lift of the wings. Obviously, loss of lift at the wings is of major importance in the piloting of a plane. Providing a display on the instrument panel indicating the angle of attack provides the pilot with important information useful for maintaining a safe attitude while flying.
There have been prior attempts to provide an aircraft pilot with information from which the pilot can take corrective actions to avoid or minimize the entry of excessive angles of attack, but each prior effort has been subject to limitations in its utility for light aircraft. A major shortfall of known prior efforts has been their reliance on alternating current, a power source not generally available in light aircraft. These efforts have employed equipment that requires A.C. power for components such as synchro transmitters and servo repeaters. Also, potentiometers and gear trains have been employed to enhance signal resolution. These types of systems are costly to manufacture and thus, their use has been largely restricted to large expensive aircraft.
Prior systems based on A.C. power supplies generally have required a method of amplifying the small detected angle for proper viewing by the pilot on a rotary dial spanning 360 degrees. Most cockpit indicators require a servo repeater and a gear train to amplify the sensed indication for meaningful viewing by the pilot. One such system is described in U.S. Pat. No. 3,475,958 issued Mar. 16, 1967 to Sabadishin and Argentieri (the inventor herein) and incorporated herein by reference. Since most indicator system currently employ a gear train to amplify the angle of attack angle of 18 degrees to approximately 360 degrees for best viewing and indication to the pilot, stops are employed at the transducer to maintain the system in mechanical synchronization. The need for approximately 360 degrees is because of the use of a rotary dial type indicator.
The stops, the gear trains and the related shafts have been a constant source of problems such as problems associated with slippage. Furthermore, there are substantial maintenance requirements for system calibration. The angle of attack system described herein addresses the cost and technical problems of the prior known efforts. Additionally, a display is provided that is vertically oriented rather than circular, thus providing an easy means to observe indication of angle of attack.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view showing the relative position of an airfoil in cross-section, with respect to the relative wind, the chord line of the airfoil and the angle of attack.
FIG. 2 is a circuit diagram of a transmitter suitable for use in accordance with a preferred embodiment of the invention.
FIG. 3 is a circuit diagram of an indicator suitable for use in accordance with a preferred embodiment of the invention.
FIG. 4 illustrates the mechanical configuration of the transmitter according to the invention.
FIG. 5 is a plan view of the angle of attack indicator according to the present invention.
FIG. 6 provides a schematic top view of a circular mask connected to a movable vane in accordance with the present invention.
FIGS. 7A and 7B respectively illustrate schematic views of the change in wing cross-section chord line angle as a function of the degree of flap extension of the airfoil relative to the zero reference and incident wind direction.
FIG. 8 illustrates a circuit block diagram for compensating the indicator zero due to flap extension according to an aspect of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, wherein like reference numerals are used to indicate like parts, and in particular to FIG. 4, transmitter 100 includes a vane 110 that is exposed to the slip stream outside an aircraft. The vane is directly coupled via shaft 115 to a circular mask 120 that is located between a set of circularly arranged illuminators such as LEDs 140 on one side and an associated set of photo sensor detector devices 160 on the opposite side. As shown in FIG. 4, there is a one-to-one correspondence between the two sets 140 , 160 . Mask 120 includes apertures 122 disposed in a corresponding circular pattern and is rotatable in response to the moveable vane 110 . The mask operates to cover certain ones of the light emitting devices based on the position of the mask and the spaced apart slots or apertures, which enable radiation from at least one of the illuminated light emitting devices to pass to the corresponding detector for causing detection. The LED arrangement is preferably mounted on a printed circuit board 105 . Electronic components which include decade counters 165 are also disposed on PC board 105 and operate at a clock frequency f to alternately illuminate the series of LEDs. A detailed illustration of the electronic circuitry is depicted in FIG. 2 . The number of LEDs employed in the system is relative to the angle that is desired to be measured. As previously mentioned, displaced opposite every LED on PC board 105 (i.e. emitter board) is a corresponding photo transistor disposed on a second PC board 109 . Electronic circuitry including reset detector logic 163 is also disposed on PC board 109 . When a photo transistor detects a lit LED, a reset signal is generated which resets the decade counters 165 and restarts the alternate illumination of the LEDs 140 . The mask, driven by the vane via shaft 115 operates to cover the illuminated LEDs corresponding to the vane displacement angle. Therefore, a reset signal is generated by the photo transistor when the first lit LED is encountered corresponding to the vane angle of attack position.
As shown in FIG. 3, the indicator 200 operates in synchronism with the transmitter 100 . A clock signal (CLOCKin) generated at the transmitter via clock circuitry 170 is hard wired over line 172 to the indicator 200 , and drives the count of corresponding decade counters 265 . These decade counters alternately illuminate a set of indicator display LEDs 240 . An exemplary configuration of display indicator 200 is depicted in FIG. 5, where each of the display LEDs in the array 240 is configured within a housing 205 in the cockpit and oriented in a vertical fashion with corresponding indicia 222 to provide visual indication of the angle of attack of the aircraft. Note that, in the preferred embodiment, the electronic circuitry associated with the display indicator 200 , including the decade counters 265 and LED array 240 , may be disposed on and interconnected via a PC board. Referring again to FIG. 3 (in conjunction with FIG. 2) reset signal generator logic circuitry 163 , 164 (FIG. 2) at the transmitter is hard wired via line 173 to indicator 200 to reset the indicator decade counters 265 (and hence indicator LEDs 240 ) and therefore maintain the visual indication to the pilot in synchronization with the transmitter.
To elaborate, if the incident wind onto the airplane wing is such that a five degree displacement of the vane from the chord line of the wing results (i.e. a change of from zero to five degrees), then the movement of the vane of an amount equivalent to five degrees causes subsequent rotation of the circular mask by an equivalent amount, so that the transmitter mask is covering the first 4 LEDs equivalent to the 5 degree displacement of the vane from the chord line. In synchronism with the transmitter via the clock frequency f, the display indicator will show five LEDs lit. The transmitter decade counters 165 are reset (pin 15 ) when the fifth photo transistor in the photo-array 160 (FIGS. 2, 4 ) detects a lit LED. At the same time the reset signal which is hard wired to the indicator will reset the decade counters 265 (pin 15 ) of the indicator at the same synchronous count. The clock maintains this cycle of counts at the clock frequency which is input to both the transmitter and display indicator decade counters 165 , 265 (pin 14 ) and there will be a steady indication of 5 degrees until the vane changes its angular position. A new count is generated up or down in synchronism with the vane's increase or decrease in angular position. Note that the clock enable input is represented at pin 13 for each of the decade counters.
As shown in FIGS. 4 and 6 there is illustrated the unique construction of the mask and its features of amplifying the small detected angle of attack without utilizing a gear train. The array of transmitter LEDs are displaced over an angle of substantially 360 degrees. The mask which is directly attached and driven by the vane, moves through an angle equal to the angle to be measured. In this case the angle is 22 degrees. The effective amplification is achieved by the construction of the mask, as shown in FIGS. 4 and 6. Each consecutive window or slot of the mask, of which there are 22 (1, 2, 3, . . . 21, 22) shown, is constructed one degree larger than the previous window. Each consecutive window or slot has an equal width w and a length (L 1 , L 2 , L 3 , . . . L 21 , L 22 ) which is successively larger than the previous slot length so as to correspond to an angular measurement associated with the angle of the air flow. In the preferred embodiment, the configuration of the mask is in the form of a circular disk with slots positioned as shown in FIG. 6 and radially from the center aperture C (for receiving the shaft) so as to achieve a resolution of substantially 1 degree. Note that lesser or greater resolution may be achieved by varying the configuration of the mask (i.e. adding or removing slots, which may result in an increase or decrease in the overall size of the mask) with a corresponding increase or decrease in the number of emitters and detectors respectively positioned on opposite sides of the mask. At the zero position of the vane and mask all LEDs in the transmitter are facing open windows or slots, and can be detected by the corresponding photo transistors. However, since the transmitter LEDs are sequenced ON by the decade counters 165 at the clock frequency f, the first LED at the zero position (i.e. LED 1 of FIG. 6) will cause activation of the reset signal (FIG. 2) and cause the decade counters 165 to start their count over. The same reset signal is sent to the indicator decade counters 265 which causes only the zero position indicator light LED to be illuminated, and thus appear to remain illuminated due to the clock frequency f. When the vane moves to a new angle, let's assume the new angle is the one degree position, then the mask will be moved to cover the zero position transmitter LED while all the remaining transmitter LEDs are remaining visible to the photo transistors through the mask's open slots. The decade counters 165 will be reset when the corresponding photo transistor in array 160 is turned ON by the second LED (i.e. LED 2 of FIG. 6 ). This causes a corresponding reset of the decade counters 265 in accordance with the clock frequency which allows the zero and the one degree indicator light to effectively appear to remain ON. That is, the frequency with which the zero and one position indicator LEDs will alternately illuminate is much greater than the eye flicker rate so that the user effectively views the display 200 as a solid light bar. There will be greater or lesser vertical illumination of the display indicator as the vane and attached mask move to a larger or smaller angle.
As mentioned, the clock frequency is set higher than the eye flicker rate, and therefore, the indicator display appears to be a solid light bar. This feature provides an indication of angle of attack without creating a distracting flicker on the instrument panel.
This unique mask arrangement eliminates all mechanical gearing usually associated with prior angle of attack indicators and employed to amplify a signal at the transmitter source and/or indicator. No synchronism of mechanical parts are required, so stops are not required at the transmitter vane for synchronizing the indicator with the vane.
As shown particularly in FIGS. 2, 3 , 4 , and 6 , this preferred embodiment of the invention is an all solid state direct current (DC) power system. The system is preferably powered by a 12 volt power supply. The D/C power system is well-suited for installation on the smallest aircraft which do not employ alternating power sources, but is not limited to small aircraft. Large aircraft would also benefit since a direct current system is less expensive, and the D/C power supply on an aircraft is more reliable than an A/C source. An additional advantageous feature of the present invention consists in the fact that only four wires are needed to connect between the transmitter and display indicator, as shown in FIGS. 2 and 3. That is, a positive (12 volt supply) and a negative (ground) terminal, as well as a reset signal and clock signal are utilized in connecting between the transmitter and display indicator to allow the indicator and transmitter to be in electrical communication and synchronism. This allows the repetition of the angular measurement associated with the airflow incident to the airfoil without any servos, but rather using complete solid state electronics. A further advantageous feature is that the only moving part is the transmitter vane and its attached mask.
The use of decade counters provides for the possibility of a large number of LEDs to associate with particular angles and resolution. In the preferred embodiment, each of the ten counts associated with a corresponding decade counter (of which there are three) is associated with a one degree angle. Accordingly, this provides a possibility for 30 counts before one runs out of one degree increments or before one runs out of room on the decade counter for illuminating another LED.
Another enhancement to the system as described herein, is illustrated in FIG. 8 . FIG. 8 depicts an embodiment to the electronic circuitry described herein where the circuit operates to compensate for a change in chord angle by shifting the system zero reference. This change in chord angle is a result of deployment of the aircraft flaps. Referring now to FIGS. 7B, it can be seen that when an aircraft's flaps are deployed, the wing cross-section chord line assumes a higher angle to the relative wind. As shown in FIG. 7B the angle B is larger than the angle A and varies with the degree of extension of the flap. Therefore, provisions must be made to display this to the pilot of the aircraft. During calibration, the wind vane is set up so that the zero system reference is known. This is represented by chord line X as shown in FIG. 7 A. Generally, the vane is set up so that it is parallel to the wing and thus, to the chord line. This may typically be accomplished by constructing two points or pins that protrude from the fuselage and that are at the same angle as the wing. One may then place a level or other measurement instrument onto the wing to determine what the particular angle is. The vane is then set up at the same angle and locked into place via conventional means. However, and as can be seen in FIG. 7A, when the flaps are lowered, and by the definition of the wing cross-section chord line as the line that connects the trailing edge of the wing with the center curvature of the wing, the chord line Y is at a higher or larger angle (i.e. angle Φ) than that of the original. Accordingly, the wing has a new zero reference point (i.e. chordline Y). However, one can not simply adjust and calibrate the vane with the new angle. To overcome this problem, the circuit described below with reference to FIG. 8, permits an electronic readjustment or calibration of the angle readout at the display indicator.
Referring now to FIG. 8, the system provides that when a zero shift is selected by an extension (or retraction) of the flap position by a predetermined amount, a signal is generated indicative of the flap position which is input to module 310 which enables a corresponding “divide by N” line. The transmitter clock 170 operates in the usual manner to generate a clock frequency signal which passes through gate logic module 320 to display indicator 200 . The clock signal is allowed to clock the indicator display through the gate logic until the “divide by N” module 330 is satisfied. At the same time however, the clock signal 322 output from gate logic module 320 to the transmitter is blocked until the “divide by N” function is satisfied. This process advances the indicator display by the amount of the angular wing chord change due to the flap extension. The gate logic module 320 then allows the clock signal to activate the transmitter count which adds the vane position to the indicator display. The reset signal generated in the transmitter for a specific vane position then resets the transmitter, indicator, and the “divide by N” count and starts the described process over at the prescribed clock rate. Note that module 330 may be an additional decade counter where the given flap signal is indicative of the offset amount.
An example of the operation of the circuit is as follows. When the flaps are lowered by, for example, pilot action, a new wing chord line represents a theoretical degree zero shift of, for instance three degrees. The flap signal then selects a “divide by 3”—the indicator count will result in a display of three degrees. Up until that time the transmitter is blocked so as not to clock the vane position. When the “divide by 3” criteria is satisfied, the transmitter is then allowed to clock the vane position and add its count to the indicator which then displays the increase in the angle of attack.
While the foregoing describes the preferred embodiment of a system for displaying the angle of attack on a vertical light bar, it is to be understood that any electronically generated display would be suitable, such as simulation of a rotary dial by illumination of an electronic display. An additional feature is the generation of a warning signal, such as an audible signal (such as a horn or buzzer) or physical signal (such as a stick vibration) when excessive angle of attack is being approached. Also, a flashing light bar might be employed to catch the pilot's attention in case of a high angle of attack. This may be accomplished via placement of particular transmitter LEDs and detectors at discrete positions associated with certain threshold angles. That is, a discrete LED may be placed anywhere along the appropriate required angles. For instance, when the wing flap is lowered, one of two discrete position LEDs may be activated so as to indicate the appropriate angular change. Conventional electronic circuitry may be employed to provide such indicator signal to the indicator 200 with corresponding electronic detection circuitry to receive the signal and provide the appropriate output to the user. One can have any number of discrete positions in order to transmit specific signals (for example, dependant on flap position) to provide any type of additional indication, as well as a corresponding slot and photo detector associated with that specific LED to provide appropriate detection and signal transmission. An example is depicted in FIG. 6 where slot 23 is used to represent a discrete position associated with a warning or indication signal generated through corresponding emitter/detector operations.
Although the invention has been described and pictured in a preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example, and that numerous changes in the details of construction and combination and arrangement of parts may be made without departing from the spirit and scope of the invention as hereinafter claimed. It is intended that the patent shall cover by suitable expression in the appended claims, whatever features of patentable novelty exist in the invention disclosed. | The angle of attack of an airfoil moving through the air can be detected and a display provided electronically through use of an all-solid-state system powered by a D.C. source. A wind vane mounted on one end of a shaft is exposed to the airflow while a windowed mask is provided at the other end of the shaft. By providing an appropriate array of openings in the mask, and a series of associated optical transmitters and receivers on opposed sides of the mask, extremely fine sensitivity can be provided in detection of angle of rotation of the mask and thus in the angle of rotation of the vane. The angle of the vane is directly established by the angle of attack. The detected angle of attack is then displayed on a vertically oriented light bar on the instrument panel, for instance in a light aircraft. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to the broad field of radar counter measure devices, and more particularly to a system of at least one decoy radar transmitter, deployed away from and linked to a main tactical radar complex, for protecting said radar complex against attack from an armed radar homing missile by providing radar emissions which are phase coherent to the transmission of the radar complex.
Tactical stationary radar facilities are normally deployed at locations to provide surveillance of a portion of airspace to detect moving targets. These radar complexes usually employ a parabolic reflector type main antenna which generally comprises some predetermined array of feedhorns. The object of the antenna is to direct a pulsed pencil beam of radiation, known more commonly as the main lobe of radiation, in desired directions normally fanning the airspace. In addition to the main lobe, the radar antenna also transmits other unwanted radiations, known as side lobes, which result principally because of imperfections in the radar antenna design.
Radar radiation reflections from objects within the conveyed airspace are received by the radar receiver and are generally correlated by a moving target indicator (MTI) type processor which is generally incorporated as part of the radar receiver. The MTI usually is equipped with a signal conditioning and filtering processor which utilizes the phase information from the reflected pulse radiations to determine valid moving targets from existing environmental clutter. In operation, the radar transmitter sends out pulsed energy in an aimed direction at a predetermined pulsed repetition frequency (PRF). Reflections may be returned from a number of objects in each aimed direction within a known time portion (target return time) of each period of the PRF. The filter signal processor of the MTI normally compares the phase of successive reflected pulsed radiation information to discriminate moving targets from existing clutter. Returned pulse radiation which has little or no phase differences between successive reflections is usually considered as clutter and is rejected from other returned pulse radiation which bear substantial phase differences. The reflected radiation information passed by the MTI filter processor is considered as potential moving targets.
Recently, specific attack weaponry, known commonly as anti-radiation missiles (ARM), have been designed to home in on the side lobe radiation transmitted by the radar antenna for the purposes of destroying the radar facility. Some of these ARM's use broadband tuned receivers adjusted to radar frequencies as a means of direction tracking. Their guidance systems are known to direct the missile trajectory normal to detected wavefronts of the side lobe radiation generated from the main radar antenna, whereby the ARM may be automatically steered to the center of the radar antenna. These type ARM's are limited in their guidance dynamics by the response of their servodynamic mechanisms which is primarily interested in direction steering the ARM in the path toward the source of side lobe radiation.
One proposed method of counter measure against an ARM attack is the strategic deployment of one or more small radar transmitters, known as decoys, away from the main radar site. The purpose of these decoys is to transmit signals which attempt to imitate the main radar side lobe emissions to confuse an ARM that may be attacking a radar complex and cause the attacking ARM to impact harmlessly at a point away from both the main radar complex and the decoys. More specifically, the decoy transmissions are designed to combine in space with the main radar side lobe transmissions to compositely form wavefronts which appear to the guidance system of an ARM as being transmitted from a virtual side lobe radiation source remote from either the main radar complex or the decoy. These compositely formed wavefronts maintain confusion within the ARM's guidance system until the radar transmission wavefronts of either the main radar or decoys are singularly detected by the ARM; but by this time, it is estimated that the guidance mechanisms of the ARM are unable to respond to redirect the ARM away from the designated impact point set up by the compositely formed wavefronts. In order to confuse the ARM in the aforementioned manner, the decoys must approximate the main radar side lobe emissions as closely as possible. However, if the side lobe radiation is not emulated properly by the decoy, it may in addition to confusing the ARM also confuse the MTI function of the main radar. One likely possibility is in the case when the decoy signals are reflected off of stationary clutter and are received by the radar MTI processor during the target return time.
The side lobe radiation of some known proposed types of decoys are triggered off of the main transmission pulse of the radar which provides for time synchronizations of the side lobe radiation of the decoy with the main radar side lobe radiation, but does not provide for any phase coherent relationship therewith. Reflections off of stationary clutter from the side lobe radiation of these types of decoys may appear to the MTI portion of the radar receiver as if the Earth is shaking back and forth, in which case, all such clutter may have apparent doppler effects and be passed through the MTI filter processor. Thus, the side lobe radiation from these types of decoys may destroy the filter processing of the MTI, under certain conditions, by producing false doppler phase changing effects causing stationary clutter to be falsely identified as moving targets. Accordingly, if decoys of this type are used as a counter measure against attacking ARM's, the MTI processor of the main radar may not be capable of nulling out clutter properly under all conditions and in some cases, it may be difficult to distinguish an actual moving target from unfiltered clutter. Therefore, it appears that if decoys are to be a viable counter measure against ARM's for protection of a radar complex, the imitation of the main radar side lobe emissions by the decoy should be enhanced to the point where reflections from clutter will not interfere with the MTI processor's rejection of unwanted clutter.
In another aspect of main radar transmissions, the high frequency carrier waveform within the pulsed transmissions of the main radar are subjected, at times, to certain coded phase reversal patterns, like Barker codes, for example. Previously proposed decoy systems are not known to emulate main radar side lobe radiation to this extent. It may be possible, under some conditions, that the guidance system of an ARM may be capable of distinguishing the different phase patterns between the main radar and decoy side lobe radiation. To improve upon the counter measure protection provided by a decoy system, a better replica of the main side lobe radiation which includes these phase reversal patterns as provided by the decoy transmissions should be considered.
In addition, most known previously proposed decoys are to be individually provided with operating power away from the radar by means of an engine-generator set. In the case in which a plurality of decoys are deployed about the radar complex, each would require its own engine-generator set and associated fuel storage capabilities. Such proposed decoy installations have been considered relatively expensive and heavily burdened with mechanical apparatus which may tend to reduce their availability. Any improvement in decoy systems which would simplify the method of providing operating power hereto would surely enhance the probability of their becoming an integral part of all tactical radar complexes in the future.
SUMMARY OF THE INVENTION
In accordance with the present invention, a decoy radar transmitter is governed by a control signal derived from a main radar transmitter to emit radiation which is phase coherent with the carrier frequency content of the main radar transmissions. More specifically, a main radar-to-decoy link couples the main radar transmitter with at least one decoy radar transmitter. A portion of the link located at the main radar transmitter derives a composite control signal comprising a phase coherent subharmonic of the carrier frequency of the main radar, a signal representative of a phase coded modulation sequence of the carrier frequency transmissions of the main radar, and a signal having a power content. The composite control signal is transmitted to at least one decoy radar transmitter over a single conduction path. Another portion of the link is located at the at least one decoy radar transmitter to receive the composite control signal and to separate therefrom the power signal which is used for energizing the decoy radar transmitter. In addition, the another portion also separates the phase coherent subharmonic and the phase coding representative signal from the composite control signal. A frequency multiplication is performed to increase the frequency of the separated phase coherent subharmonic, preferably to the approximate value of the carrier frequency of the main radar transmitter. The phase coded modulation sequence is obtained from the separated phase coding representative signal and used to modulate the frequency multiplied phase coherent subharmonic to form a control signal which governs the radar emissions of the at least one decoy radar transmitter.
Preferably, the phase coded modulation sequence of the carrier frequency is derived at the main radar transmitter by frequency shift keying between a number of predetermined frequencies, each of which corresponding to a phase polarity of the phase coding sequence of the carrier frequency of the main radar transmitter. The frequency shift keyed signal is combined with the phase coherent subharmonic to compositely constitute a portion of the control signal. At the at least one decoy, the frequency shift keyed signal is separated from the composite control signal, preferably by a bandpass filter, and the phase coded modulation sequence is obtained by frequency discrimination of the filtered signal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified sketch of a radar installation suitable for embodying the principles of the present invention; and
FIG. 2 is a schematic block diagram of a main radar-to-decoy link suitable for use in the embodiment of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a main radar complex 10 including a radar transmitter (not shown) and a directional antenna 12 both of the type wellknown in the pertinent art, is tactically located for surveillance of an air space 14. Deployed a predetermined distance from the main radar complex 10 is at least one decoy radar transmitter 16 which includes a conventional omnidirectional type transmitting antenna 18. A main radar-to-decoy link, which may be comprised of portions 20 and 22 of the main radar 10 and decoy 16, respectively, tied together by a single signal path 24 which may be a coaxial cable or other suitable conducting path, delivers a composite signal formed by the portion 20 of the main radar 10 and transmitted over the conduction path 24 to the portion 22 of the decoy 16. The composite signal passing over the single conduction path 24 provides the decoy with its sole source of operational power and a control signal which governs the radar transmissions of the decoy 16.
In operation, the radar antenna 12 of the main radar complex 10 may generate a certain amount of side lobe radiation denoted simply in the sketch of FIG. 1 by the dotted line 26. That portion 20 of the radar-to-decoy link derives signals which are representative of the characteristics of the transmissions 26 of the main radar 10. These derived signals are compositely conducted along with a power signal through path 24 to the portion 22 of the decoy 16. (The portions 20 and 22 of the radar-to-decoy will be described in greater detail hereinbelow. Separation of the power signal from the derived signal is performed at portion 22 of the decoy 16. In addition, portion 22 deciphers the main radar emission characteristic information from the received desired signals and governs the radiation transmitted from the decoy antenna 18 in accordance therewith. The decoy transmissions are denoted simply in the sketch of FIG. 1 on the dotted lines 28. As was described briefly in the Background section, some emissions 28 from the decoy 16 may combine with the main radar emissions 26 to form a number of wavefronts, one of which is shown simply at 30, in accordance with well known principles of microwave radiation theory. These wavefronts 30 are produced to confuse any attacking anti-radiation missles (ARM) or other similar radar homing type attack missles, shown simply at 32, and cause the attack missle 32 to impact harmlessly in an area 34 remote from both the main radar complex 10 and decoy 16.
In addition to confusing the guidance systems of the ARM 32 by effecting wavefronts 30 in the airspace 14, the radar emissions 28 may also be reflected from stationary clutter 36, such as mountain ranges, or slow moving clutter 38, such as rain clouds, for example. As shown simply in FIG. 1, these reflected emissions 35 and 37 may be received by the antenna 12 of the main radar complex 10 and may possibly interfere with the signal processing of a moving target indicator (MTI) system which is a conventional part of the radar complex 10. However, the radar-to-decoy link of the preferred embodiment provides for governing the radar emissions 28 of the decoy 16 to be phase coherent with the radar transmissions of the main radar 10, which will be described in greater detail hereinbelow, thus, greatly reducing the probability of interference with the workings of the MTI processor as a result of reflections from the decoy emissions. Furthermore, the radar-to-data link is additionally capable of governing the radar emissions 28 to the extent of imitating any sophisticated phase coding, similar to that of Barker codes, for example, which may be imparted to the radar emissions 26.
Referring now to the radar-to-decoy link which is displayed functionally in FIG. 2, a signal 50, which is representative of the unmodulated carrier frequency of the radar transmitter 10, is input to a frequency divider function 52 incorporated into the portion 20 of the main radar 10. The signal 50 is preferably selected at a point in the radar transmitter 10 where the carrier frequency is in the range of hundreds of megahertz prior to being boosted to the gigahertz range. Consequently, the frequency divider 52 may be comprised of a cascaded number of digital down counters, the design of which being well known in the pertinent art. The resulting output signal 54 of the frequency division is a phase coherent subharmonic of the unmodulated radar carrier frequency and is subsequently pulse modulated by an amplitude modulation function 56 which is cascased downstream of the frequency divider network 52. A pretrigger signal 58 which may be selected from the circuitry of the radar transmitter 10, preferably from that portion which produces the phase coding of the carrier waveform, is used to provide an indication to the amplitude modulation function 56 that the radar 10 will transmit a pulsed envelope of radiation at some predetermined later time. The pretrigger signal 58 is generally synchronized with the pulse repitition frequency (PRF) of the radar transmitter 10 which may be either fixed or variable. The function 56 may key on the pretrigger signal 58 to pulse modulate the phase coherent subharmonic signal 54 based on a predetermined time delay and pulse width, both of which may be adjusted for the purpose of compensating for delays resulting from the circuit embodiment functionally shown in FIG. 2 or even, for further confusing the ARM by manipulating the radar transmissions of the decoy 16. Thus, the principal function of the amplitude (pulse) modulator 56 is to provide a signal 60 having a pulsed envelope of the phase coherent carrier frequency subharmonic in some predetermined timed relationship with the pulsed transmissions of the main radar 10, the strategy being to most effectively confuse the ARM with the embodied circuitry. Pulse modulators, like function 56, are well known to the pertinent art and are generally embodied with high frequency switching diodes, like pin diodes, for example, to provide a configuration in which there exists a delay element responsive to the pretrigger signal and a pulse generator element responsive to the delay element to generate the output signal 60.
A conventional frequency shift keying (FSK) function 62 is additionally disposed in the portion 20 of the radar-to-decoy link for the purposes of detecting the phase coding imparted to the carrier frequency of the radar 10 prior to transmission. Two suitable frequencies F 1 and F 2 may be selected from a range of available frequency signals within the radar transmitter 10 and may be coupled to FSK function 62 over signal lines 64 and 66, respectively. It is understood that a frequency generator may alternatively be employed within the portion 20 to generate the freqencies F 1 and F 2 in lieu of selecting them from the radar transmitters without departing from the scope of the invention. A third input signal 68 to the FSK function 62 may be provided from the phase coding portion of the radar transmitter 10 and may be concomittantly representative of the phase polarity being imported to the carrier frequency being transmitted by radar 10. Accordingly, the input signal 68 governs the selection of use of the frequencies F 1 and F 2 supplied to FSK function 62 corresponding to the phase coded polarity imparted to the radar carrier frequency.
A sequence of selected frequencies including F 1 or F 2 effected by the FSK function 72 is coupled to a conventional combiner 70 over signal line 72. In the combiner 70, the sequence of selected frequencies including F 1 and F 2 , which are representative of the phase coded polarity of the main radar transmissions, is conventionally combined with the phase coherent subharmonic of the main radar carrier to form a control signal 74 which includes the phase characteristic information of the main radar carrier frequency transmission.
The control signal 74 may be combined with a power signal 76 which should be of a low enough frequency to be easily separated from the control signal 74 at a downstream point within the radar-to-decoy link. Preferably, the power signal 76 is derived from a convenient 400 HZ power source generally disposed within the radar transmitter 10. The combiner, which is shown at 78, may be embodied with well known circuits in a configuration which permits little to no interaction between the high frequency control signal 74 which is in the range of tens of megahertz and the low frequency power signal 76 which may be approximately 400 Hz. A suitable embodiment (not shown) may be comprised of a first circuit element having principally capacitive properties of an appropriately chosen value being disposed in series with the control signal 74 so as to provide very low impedance to high frequency components, and very high impedance to low frequency components; a transformer element which provides isolation for the coupling of the power signal 76 to the combiner 78 and may, in addition, step up the voltage of the power signal 76, say in the order of thousands of volts, to reduce the losses in the signal transmission through the coaxial path 24; and a second circuit element having principally inductive properties of an appropriately chosen value being disposed between the capacitive element and transformer element to provide high impedance to the high frequency components and low impedance to low frequency components. A composite signal 80 may be formed at the connection of the capacitive and inductive elements, for example, for transmission through the coaxial path 24.
As was described in connection with FIG. 1, the radar 10 and decoy 16 are connected by a single conduction path 24 which may be a coaxial cable, for example. A suitably chosen cable may be one which has a cable load of about 400Ω and an impedance of around 50 to 75Ω. It is not necessary for the cable to be impedance matched for the power signal frequency at the receiving end, in particular, but it should exhibit short line characteristics at the power signal frequency and act as a shunt capacitor. Normally, the working voltage of the cable is chosen to be approximately twice the operating voltage which may be around 1500 volts RMS so that the 400 Hz power signal conducted to the decoy is in the range of 4 to 5 KW which adequately meets the requirements of most decoys.
Separation of the power signal 76 from the composite signal 80 is performed by a separator function 82 which may be embodied in a similar configuration as that of the combiner 78. That is, the composite signal 80 may be coupled to both a capacitive and an inductive element (not shown), the inductive element having an appropriately chosen value to pass substantially the low frequency power signal 84 attenuated slightly by the loss of passive elements in the link and the capacitive element having an appropriately chosen value to pass substantially high frequency control signal 86 also attenuated slightly by the loss of circuit elements of the link. The passed power signal may be coupled to a conventional AC to DC power supply converter 88 wherein a transformer element may be utilized to step down the voltage of the power signal 84 to a convenient operational level suitable for the type of circuitry embodying the decoy 16. The converter 16 may additionally rectify and filter the stepped down voltage signal to effect a DC voltage power signal 90 which may be distributed to the circuits of the decoy 16.
The separated high frequency control signal 86 may be coupled simultaneously to two conventional bandpass filters 92 and 94. The bandpass filter 92 has a center frequency value selectively adjusted so that it passes the frequency of the subharmonic signal 54 and substantially filters out the FSK frequencies including F 1 and F 2 . Likewise, the bandpass filter 94 has a center frequency selectively adjusted so that the filter 94 passes the frequencies including F 1 and F 2 , but substantially filters out the subharmonic frequencies of signal 54. Cascaded with the filter 92 is a frequency multiplier function 96 which multiplies the output of filter 92 to a higher frequency value which may be the value of the carrier frequency used in the main radar 10. The multiplier 96 may be embodied with a phase-locked loop (PLL) for performing the initial stages of multiplication, say while still in the hundreds of megahertz range and the final stages of multiplication may be performed by any number of well-known circuits including a cascaded number of voltage doublers comprised of transformer diode configurations, for example, which may ultimately generate a phase coherent replica 97 of the carrier frequency of the main radar 10. Concurrently, the output of the bandpass filter 94 may be voltage limited by a conventional limiter circuit 98 to effect a substantially constant amplitude waveform which may be thereafter submitted to a frequency discriminator 100. The frequency discriminator 100 identifies the frequency, like F 1 or F 2 , for example, present at the output of filter 94 and produces a signal state, normally a high level (true) or low level (false), at its output 102 representative thereof. Thus, the signal state of the discriminator output 102 varies in accordance with the phase coding specified at the main radar 10.
A conventional phase modulator circuit 104 may provide for both an in-phase and 180° out-of-phase split of the phase coherent replica signal 97 and in addition, selects one of either the in-phase or out-of-phase signals in accordance with the state of signal 102. Accordingly, the output signal 105 of the phase modulator 104 is not only a phase coherent replica of the pulsed carrier frequency radiation of the main radar 10, but also emulates the phase coding of the carrier frequency within the pulsed envelope. A conventional radar amplifier 106 is governed by the output signal 105 to drive an omni-directional antenna 18 which suffices to generate side lobe type radiation that substantially emulates the amplitude characteristics of the side lobe type radiation of the main radar.
In summary, at the main radar 10, an unmodulated radar carrier frequency monitored signal or some phase coherent representative thereof 50 is frequency divided (52) to effect a phase coherent subharmonic signal 54 which is pulsed modulated (56) in a predetermined time relationship with the pulsed modulation of the radar transmissions utilizing pretrigger information (58) supplied by the radar transmitter 10. In addition, the phase coding information imparted to the carrier frequency within the pulsed transmissions of the radar 10 are specified by frequency shift keying between at least two frequencies F 1 and F 2 (62). For example, if the carrier frequency is to be transmitted inphase during a portion of the pulsed transmission, then frequency F 1 may be selected and similarly, if the carrier frequency is to be transmitted 180° out-of-phase during another portion of the pulsed transmission, then frequency F 2 may be selected. The frequency representative phase coding information is combined with the pulsed phase coherent subharmonic (70) to form a control signal 74 which is to be used to govern the transmissions of the decoy transmitter 16. A power signal 76 which may have a low frequency of approximately 400 Hz is stepped up in voltage, say to one or two kilovolts, for example, and combined with the control signal 74 for transmission over the single conduction path 24.
At the decoy transmitter 16, the high voltage power signal is stripped (82) from the composite signal 80 and manipulated to provide the primary source of power to the decoy radar transmitter. The pulsed phase coherent carrier frequency subharmonic and the frequency shift keying signal representative of the phase coding are separated (82) from the remaining control signal 86 utilizing filters 92 and 94, respectively. The separated phase coherent carrier frequency is multiplied in frequency (96) to the value of the radar carrier frequency, thus effecting a phase coherent replica of the transmitted carrier frequency of the radar 10. The sequential phase coding information is discriminated (98 and 100) from the FSK signal and correspondingly imparted to the pulsed replica 97 of the radar carrier frequency at 104, thus reproducing the phase coding of the main radar transmitter 10 within the pulsed replica of the phase coherent carrier frequency 97. The phase coherent, phase coded, pulsed replica of the carrier frequency signal 105 then governs the radar transmissions of the decoy utilizing a conventional radar amplifier 106 and omnidirectional antenna 18 which are suitable for the purposes of generating side lobe type radiation. In this manner, a decoy radar transmitter 16 is governed by the main radar transmitter to generate radar emissions which have coherent phase characteristics with the transmissions of the main radar 10.
It is understood that while the present invention has been described hereinabove in connection with a particular embodiment, it should not be so limited to any one embodiment, but rather should be construed broadly in accordance with the breadth and scope of the following claims. | A decoy radar transmitter governed by a control signal derived from a main radar transmitter to emit radiation which is phase coherent with the carrier frequency of the main radar transmission is disclosed. A section of the main radar transmitter generates a control signal compositely formed by the combination of derived signals including a phase coherent subharmonic of the carrier frequency of the main radar, a frequency shift keyed signal and a signal having a power content. The frequency shift keyed signal is representative of a phase coded modulation sequence of the carrier frequency transmissions, each frequency fo the frequency shift keying corresponds to a phase polarity of the phase coding. A single coaxial cable conducts the composite control signal to the decoy radar transmitter. Upon receiving the composite control signal, a section of the decoy radar transmitter separates the power signal from the received control signal for use in energizing the decoy radar transmitter. The other signals are also separated from the compositely received control signal, whereupon the separated phase coherent subharmonic is frequency multiplied to approximately the carrier frequency of the main radar and the frequency shift keyed signal is frequency discriminated to obtain the phase coding sequence. Thereafter, the frequency multiplied phase coherent subharmonic is modulated with the obtained phase coding sequence to form a signal which governs the radar emissions of the decoy radar transmitter. | 5 |
This is a continuation-in-part of application Ser. No. 07/194,339, which was filed on May 16, 1988, now U.S. Pat. No. 4,906,926.
BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to proximity sensors and related circuits, and particularly to such systems adapted for sensing metal workpieces in hostile conditions.
Proximity sensors are used in various facets of manufacturing for detecting the approach or the presence of metal objects. An example of a suitable application for such devices is for automated sheet metal forming lines such as progressive die press operations where proximity sensors could be used for determining whether or not material handling systems are properly engaging workpieces as they are moved from one work station to another. If a part engaging member such as a shovel or articulated gripper does not properly receive a workpiece and such absence is detected, the material handling and fabrication machinery could be interrupted to correct the failure. Workpieces which are not in their proper position can lead to the generation of scrap and can also damage equipment of the fabrication system.
Inductive type proximity sensors have been in use for many years and operate on the principle that approaching magnetic objects change the inductive characteristics of the sensor, which, in a simplified form, is no more than a coil of wire wrapped around a ferrite core. This change in inductance or in the corresponding impedance characteristic, produces a reduced output from a resonant tank circuit which the sensor is a part of. The tank circuit voltages are detected and output through appropriate signal processing electronics. Present proximity sensor systems operate at relatively high frequencies (e.g. 200 to 300 KHz), and are used with high "Q" tank circuits (i.e. circuits with high impedance to resistance ratios). Such sensor systems cannot sense through a layer of metal to detect objects on the opposite side of the layer, due to eddy current losses occurring in the metal layer. Accordingly, such proximity sensors have a sensing face which is nonmetallic. Typically, the coils are potted using epoxy compounds or other plastic materials which cover one sensing face. In many applications for proximity sensors such as the application discussed above, proximity sensors are exposed to extreme environmental conditions where they can be struck by metal workpieces and subjected to abrasives, cutting fluids, etc. For such applications, the vulnerable configuration of prior art proximity sensors renders them unsuited for use. Accordingly, there is a need to provide a proximity sensor which can be encased in a durable material such as a metal, while providing sensitivity for detecting other metal objects which may be fixed upon the surface of the durable material.
There is a need for such proximity sensors to be configured such that false readings or outputs thereof are not generated due to the "bouncing" of the workpiece within the manufacturing handling system. For example, if the sensor were placed upon the surface of a workpiece gripper, the gripper would initially sense the presence of the workpiece that was positioned upon it. If the workpiece bounced, however, there would be a window of time before the workpiece was repositioned or fixed upon the sensor, in which the sensor would output an erroneous indication that the workpiece was not within the gripper. Such an erroneous indication could cause great harm to the entire manufacturing process (i.e., shutting down an assembly line) and should be avoided.
In addition to the foregoing, since present inductive proximity sensors are used with high "Q" tank circuits, and since a full metallic enclosure results inherently in a circuit with a low "Q" value, there is a need for an amplifier system which can function with a low "Q" circuit and detect small changes in that "Q" value.
In accordance with this invention, several embodiments of proximity sensor systems achieving the above mentioned desirable characteristics are provided. Proximity sensors according to this invention can be encased in metal such as stainless steel while enabling the detection of approaching metal objects and, more importantly, of metal objects which are fixed in a stationary manner upon the metal case of the sensor. The resulting sensor is extremely durable and can therefore be used in hostile operating conditions. These capabilities are achieved, in part, by driving the proximity sensor coil at a relatively low frequency, for example, at less than 20 KHz. The stainless steel encasing material is relatively invisible to the low excitation frequency, since eddy current losses decrease with frequency. The reason that a portion of the sensing field extends through a given thickness of stainless steel is that one product of circuit "Q" and skin depth have been maximized. Skin depth is greater for a high resistivity material like stainless steel and it also is larger for lower frequencies. Therefore, the relative "invisibility" of the stainless is due to the low frequency used and to the high electrical resistivity of the stainless. These features make it necessary to employ relatively low "Q" tank circuits (since "Q" decreases with frequency). Various circuit designs are disclosed as means for evaluating small changes in output of the sensing inductor which provide excellent sensitivity, while enabling use of low "Q" low frequency sensing circuits. Further, the sensors of the embodiments of this invention are relatively insensitive to the bouncing of the workpiece within the workpiece handling system and provide a detection signal output even during workpiece bouncing conditions.
Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which this invention relates from the subsequent description of one preferred embodiments and the appended claims, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial view of a workpiece gripper incorporating a proximity sensor in accordance with a first embodiment of this invention.
FIG. 2 is a cross-sectional view through the gripper sensor taken along line 2--2 of FIG. 1.
FIG. 3 is a partially elevational and partially cross-sectional view of a proximity sensor in accordance with a second embodiment of this invention used in conjunction with a shovel type metal workpiece transporting device.
FIG. 4 is an electrical schematic diagram showing a simplified electrical circuit for a monitor in accordance with a first embodiment of this invention.
FIG. 5 is a simplified electrical circuit of a monitor according to a second embodiment of the invention.
FIG. 6 is a waveform diagram related to the circuit shown in FIG. 5.
FIG. 7 is an electrical schematic diagram of a sensor circuit made accordance with the teachings of this invention.
FIG. 8 is a pictorial view of proximity sensors made in accordance with a third embodiment of this invention used to properly align a metal workpiece.
FIG. 9 is a pictorial view of one of the proximity sensors shown in FIG. 8.
FIG. 10 is a pictorial view of proximity sensors made in accordance with a fourth embodiment of this invention and used to detect the height of a stack of metal workpieces.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a gripper assembly, generally designated by reference number 10, incorporating a proximity sensor 12 in accordance with one embodiment of the present invention. Gripper assembly 10 is robotically controlled to properly position gripper jaws 14 and 16 to engage a workpiece. As previously mentioned, there is a need to determine with certainty whether or not workpiece handling systems have, in fact, properly received a workpiece such as a sheet metal blank. Gripper assembly 10 incorporates proximity sensor 12 as the engaging face of jaw 16. Thus, when a sheet metal workpiece is received between jaws 14 and 16, and the jaws are clamped against the workpiece, the workpiece is in direct contact with proximity sensor 12. Due to the rugged construction of proximity sensor 12, it is capable of restraining significant gripping forces. Jaw 14 forms a gripper point 18 which slightly penetrates the workpiece surface to ensure positive engagement. Monitor 44 provides the electrical circuitry which outputs a digital signal (although analog outputs are possible) which triggers associated equipment such as warning devices or automatic shut-down systems.
With particular reference to FIG. 2, details of the construction of proximity sensor 12 are shown. Proximity sensor 12 includes a cup-shaped housing 22 made from a stainless steel material. A central depression 24, defined by top plate 25 of housing 22, receives gripper point 18 when the jaws 14 and 16 are closed without a workpiece present. An inductor coil 26 is wrapped within ferrite core 28 and potting material is employed to fill the voids around the core. Coil 26 generates a sensing field which penetrates housing 22 and is present at face 42. Additional encasing metal layers are formed by end plates 30 and 32. Columnar member 31 is also defined by housing 22 and is coupled to top plate 25 and to bottom plate 30 in a cooperative "I-beam"-like arrangement. That is, impaction force is created upon plate 25 when jaws 14 and 16 are closed. This impaction force is transmitted through columnar member 31 and subsequently to plate 30 while being distributed therethrough. Such use of member 31 minimizes the structural deformation of plate 25 by the created impaction force thereby minimizing structural failure thereof. Threaded mounting post 34 enables sensor 12 to be secured to jaw 16. Cable assembly 36 is connected to opposite ends of coil 26 and is held in position by metal tubular stiffener 38. FIG. 2 illustrates a sheet metal workpiece 40 in close contact with sensing face 42.
A proximity sensor in accordance with the second embodiment of this invention is shown in FIG. 3 and is generally designated by reference number 90. Sensor 90 is particularly adapted to be mounted to a metal workpiece engaging "shovel" 92 which is adapted to engage and lift a corner of a sheet metal blank. Shovel 92 defines a flared opened end 102 and a barrier 104 which controls the position of one workpieces. Shovel 92 is made from stainless steel with sensor 90 mounted to the bottom of the shovel, such that it senses the workpiece through the bottom surface of the shovel. Sensor 90 includes coil 94 wrapped around ferrite core 96, and is mounted to shovel 92 via bracket 98.
An example of circuitry which enables proximity sensor 12 to detect the approach of a workpiece 40 or the placement of workpiece 40 upon the sensor is shown in FIG. 4. This figure is a simplified schematic for monitor circuit 50. Circuit 50 is particularly useful for use with a low inductance sensor coil, such as that shown in FIG. 4, which in accordance with an experimental embodiment of applicant, had an inductance of about 4 mH. Circuit 50 includes a bridge circuit having a pair of arms formed by fixed value resistors 52 and 54. The lower half of one bridge is formed by voltage controlled resistor 56 which provides a variable resistance as a function of input voltage on line 58. The remaining leg of the bridge is formed by L-C parallel resonant tank circuit 64 which includes proximity sensor coil 26 and capacitor 66. Bridge nodes 60 and 61 are power inputs and nodes 62 and 63 are outputs. The outputs from bridge nodes 62 and 63 are fed into OP/AMP 70 which amplifies their difference and receives a power supply voltage at inputs 72 and 74. The output of OP/AMP 70 is directed back through bridge node 60 and is also directed through diode 76 to OP/AMP 78, having an output which drives voltage controlled resistor input 58. Line 80 provides an output signal for signal processing and threshold detecting circuits, according to well known designs.
In operation of monitor circuit 50, L-C tank circuit 64 operates at resonance and can be represented by an equivalent resistor 84. Monitor circuit 50 would preferably be designed to operate at a frequency in the range of up to 20 KHz. In one experimental embodiment, monitor circuit 50 oscillated at about 1000 Hz. During normal operation, the bridge is intentionally maintained slightly out of balance through appropriate selection of the elements of the arms of the bridge. When a metal object approaches or is fixably placed upon housing 22 proximity sensor coil 26, the "Q") of the circuit decreases due to a change in the inductance (or corresponding impedance) value of coil 26, which reduces the effective resistance of equivalent resistor 84. This imbalance causes the voltage along OP/AMP positive input 79 to decrease, which signal is fed back to voltage controlled resistor 56, causing its equivalent resistance value also to drop, tending to maintain the circuit in balance. The combined effect on the equivalent resistance of resistor 84 and voltage controlled resistor 56 causes the alternating signal through the circuit detected at output line 80 to be decreased upon the approach of a ferrous metal object to proximity coil 26 or the placement of this object upon casing 22. The circuit therefore operates as a "Q" multiplier by exaggerating small changes in the L-C tank circuit 64 provided by the balancing influence of voltage controlled resistor 56.
FIG. 5 illustrates another embodiment of a monitor circuit 106 which may be used with proximity sensor 90 having a physically large coil with a corresponding large inductance value associated therewith. This design employs a modified Colpitts oscillator, comprising coil 94 in a tank circuit with capacitors 108 and 110 with an output between the capacitors fed into emitter 112 of transistor 114. Temperature compensating thermistor 116 and variable resistor 118 are used to adjust the biasing and operating point of transistor 114. FIG. 6 illustrates oscillations taking place through monitor circuit 106. The curves can be divided into two sections, the first section 124, above dotted line 120, represents the free oscillations or "ringing" within the tank circuit which is driven by the portion of the curve represented by 122 which is the region that transistor 114 is conducting. Accordingly, the system operates like a conventional Colpitts oscillator but with the transistor operating only in one lower portion of the curve as a driver, and thus the system is a non-linear driven oscillator. Monitor circuit 106 operates best at frequencies of around 1000 Hz.
In operation, monitor circuit 106 is allowed to oscillate as shown in FIG. 6, but upon the approach of a ferrous material or the placement of the material upon casing 22, the inductive coupling and eddy current loses within that material absorb energy, thus significantly reducing the amplitude of curve 124 which is coupled to output line 126.
Referring now to FIG. 7, there is shown a sensor circuit 148 of the preferred embodiment of this invention having monitor circuit 50 coupled to a threshold circuit 150 by output line 80. Threshold circuit 150 then measures the amplitude of the oscillations associated with line 80 and compares the measured amplitude with a fixed or predetermined amplitude value stored therein. If the measured amplitude exceeds (or alternatively is less than) the predetermined value, then threshold circuit 150 will produce a signal on line 152 indicating the presence of a metal workpiece in close proximity to or fixed upon casing 22. The threshold circuit 150, in one embodiment, comprises a typical Schmitt trigger device.
The use of such an adjustable threshold circuit 150 in combination with the ability to detect a metal workpiece directly resident upon casing 22 allows sensor circuit 148 to detect only metal workpieces directly resident upon casing 22 or alternatively within some range with respect to casing 22. Additionally, the sensor 12 of this invention will not respond to substantially any stainless steel member, such as gripper point 18, due to the frequency at which the sensor 12 is oscillating. This feature, in combination with the use of the aforementioned threshold circuit 150, allows sensor 12 to detect the presence (or absence) of a metal workpiece residing between gripper point 18 and sensor 12. By allowing the sensor to determine the presence of a workpiece directly in contact with its casing and employing a thresholding circuit to allow workpiece indications upon the presence of the workpiece, on the sensor, such erroneous indications (i.e., detection of metal workpieces outside of the defined range) may be reduced. This threshold circuit 150 then produces an affirmative acknowledgement of the presence of the workpiece when the amplitude of the signal on line 80 is compared to the fixed or predetermined level in the manner previously described.
Signal line 152 is further coupled to a time delay circuit 154 which produces a signal on line 156. Delay circuit 154 maintains the signal on line 156 for a predetermined amount of time after the signal on line 152 is absent. This use of delay circuit 154 provides for the substantial reduction of detection errors associated with the bouncing of the metal workpiece off of sensor casing 22 during normal material handling or gripping operations.
That is, after the metal workpiece initially contacts sensor casing 22, signal on line 152 is generated and shortly thereafter, signal on line 156 is generated. If the metal workpiece bounces off of casing 22, then the generation of signal on line 152 is terminated, correctly indicating the absence of the metal workpiece from the surface (or close proximity to) casing 22. Since, however, the workpiece is still within the grasp of the material handling or manufacturing system (i.e., between jaws 14 and 16) such an indication would be erroneous. Therefore, time delay circuit 154 causes signal on line 156 to continue to reflect the correct presence of the metal workpiece. Upon the return of the metal workpiece to casing 22, signal on line 152 is generated and signal on line 156 continues to be held constant. It is only after a set amount of time has passed, without the further presence of the metal workpiece upon, or in close proximity to casing 22, that signal on line 156 reflects the absence of the workpiece. If this time has passed without the return of the workpiece to casing 22, then it is correctly indicated as signal on line 156 that the workpiece is no longer within this portion of the handling system.
Output device 158 may be one of a plurality of types including a programmable logic controller, and receives signal on line 156 and provides an output (i.e., such as visual display) indicating the presence, absence or, alternatively, both the presence and the absence of the workpiece within a portion of the handling or manufacturing system.
Referring now to FIG. 8, there is shown a metal workpiece alignment apparatus 160 containing a plurality of vertical members 162-172 which define a workpiece receiving area 174 upon which a workpiece 176 is to be received. Apparatus 160 further contains proximity sensors 178 and 180 which substantially correspond to sensor 12 shown generally in FIGS. 1 and 2. As shown in FIG. 9, sensor 178 (or 180) is deployed or mounted within a generally rectangular, closed housing 182 defining a face portion 184 through which sensor 178 (or 180) may direct a magnetic field. In alignment apparatus 160, sensors 178 and 180 may be deployed such that each of them is in close proximity to one of the members 162, 164, 166, 168, 170 or 172. The sensor face 184 associated with each of the sensors 178 and 180 is then positioned toward the workpiece receiving area 174. Therefore, when the workpiece 176 is placed within the receiving area 174, the sensors 178 and 180, by means of the magnetic field through face portions 184, will determine the proximity or placement of workpiece 176 within receiving area 174 in the aforedescribed manner. This determination of the presence of the workpiece 176, within area 174, will insure that workpiece 176 is properly aligned therein and the initiation of other manufacturing and/or assembly operations (i.e., the initiation of a dual press) may then begin. It should also be realized that sensors 178 and 180 may be electrically coupled to the aforedescribed monitor circuit 50 in the previously described manner, and the presence of workpiece 176 within the workpiece receiving area 174 may be affirmed by the generation of an electrical signal on line 156 to the typical output device 158 in the manner previously described.
Referring now to FIG. 10, there is shown a workpiece stacking arrangement 188 containing workpieces 190, 192, 194, 196 and 198, which are stacked in a storage arrangement. Sensors 200, 202, 204 and 206 are deployed in this fourth embodiment of this invention and are used to determine the overall height 208 of the stacking arrangement 188. That is, sensors 200, 202, 204 and 206 are substantially similar to sensors 178 and 180, shown generally in FIG. 8, and are vertically stacked upon each other such that the faces 184 associated therewith are directed to the stacking arrangements 188. Each of the sensors 200, 202, 204 and 206 has an unique height 210 associated therewith and is electrically coupled, in the aforedescribed manner, to a monitor circuit 50 and then to an output device 158. Height 210 is defined to be in one embodiment, the smallest distance from ground of a point upon face 184, of each of the sensors 200-206. The output device 158 may then be made to determine the relative height 208 of the stacking arrangement 188 by receiving each of the aforedescribed outputs of sensors 200, 202, 204 and 206. Each sensor 200- 206 will provide an output signal only if the height 208 of stacking arrangement 188 is substantially equal to or greater than its unique height 210. Monitor circuit 50 may be made to display the approximate height 208, of arrangement 188, by simply determining which of the sensors 200, 202, 204 or 206 have provided an output signal and then displaying the largest height 210 associated with this group of output producing sensors 200, 202, 204 or 206. Such an embodiment, as shown in FIG. 10, may be used in a workpiece storage area in which it is desired to gain information concerning the relative amount of workpieces still left within the area for such things as inventory purposes.
While the above description constitutes the preferred embodiments of the present invention, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope and fair meaning of the accompanying claims. | Proximity sensors for detecting the presence of metal objects such as sheet metal workpieces within workpiece engaging devices such as grippers and shovels. The proximity sensors are jacketed in a stainless steel casing, making them rugged and resistant to impact damage. Monitor circuits are used with the sensor which enable the devices to sense objects through their metal casing, these objects being disposed upon the sensor casing. A thresholding circuit and a delay circuit are further disclosed and which reduce erroneous indications of the presence of the metal objects upon the sensor. Other embodiments are disclosed which allow for the proper alignment of metallic workpieces within an area and for the determination of the height of a stack of workpieces. | 6 |
CROSS REFERENCE TO RELATED PATENT APPLICATIONS
The present application is a divisional patent application of U.S. patent application Ser. No. 10/644,130 filed on Aug. 20, 2003 now U.S. Pat. No. 7,140,533 for a “Single Piece Packaging Container and Device for Making Same.”
BACKGROUND OF THE INVENTION
The present invention is directed to packaging containers and a device for making the containers. More particularly, the present invention pertains to configurations for a packing container having self-formed end closures, created from a single piece of material. The present invention also pertains to a device for forming the containers.
Packaging for lengthy items takes many forms. One construction includes a pair of corrugated, laminated paperboard top and bottom U-shaped channels configured for one to fit within the other. Most packages formed in this manner require separate end closures or caps, usually manufactured from cardboard or wood. These caps generally are stapled to adjacent package walls. Not only does this method necessitate close-fit manufacturing, but it is also very cumbersome at installation, and may cause content damage due to incompletely formed or off-positioned staples.
In another variety of packaging container, one of the top and bottom U-shaped channels has a notch cut into opposing side walls of the “U,” so that the “U” portion may be folded over at a 90 degree angle. In such a configuration, channel ends are closed by the folded base portion and the side walls of the “U,” which are folded over adjacent side walls. To seal such a package, tape or a like strip-type adhesive sealant must be extended over the flaps that then are folded over the adjacent side walls. Even though a seal may be formed, openings may remain at the juncture of the folded-over base portion and the cover portion, seriously weakening the package. This design is disclosed in U.S. Pat. No. 4,976,374.
Another existing packaging container, disclosed in Loeschen, U.S. Pat. No. 6,382,447, resolves the above-referenced problems by providing a packaging container in which the entirety of the end closure is formed from the packaging material itself. However, the container base unit, which forms end closures for the packaging container, features mitered corners. These mitered corners require complex die-cutting with mirrored tools, and mandatory strapping at specific positions to restrain the miter flaps. The patent to Loeschen, which is commonly assigned herewith, is incorporated herein by reference.
A new, single-piece packaging container cut without miters is disclosed in application Ser. No. 10/264,506, filed Oct. 4, 2002, assigned to the assignee of the present invention and incorporated herein by reference. The end closures of this packaging container are formed from the packaging material itself. The container allows for no gaps at its closure locations, because its end closures meet or overlap along the container's main body portion, providing a high degree of structural strength and package integrity. Manufacturing the container is extremely simple and cost-effective, requiring only two straight saw-cuts on each package end.
Occasionally, packaging containers must accommodate objects with varied local height elevations, or objects that require segregation during shipping or storage. Normally, shippers rely on foam fillers or container partitions to protect such irregularly shaped or fragile objects. Foam fillers may compress, leak, or shift, and container partitions may shift or break during shipping, rendering shippers' attempts to protect their products worthless. Accordingly, there exists a need for specialized configurations for a single-piece packaging container having self-formed end closures, providing better protection for fragile and/or irregularly shaped objects than undependable foam fillers or container partitions.
BRIEF SUMMARY OF THE INVENTION
Configurations for a packing container formed from a single, preformed, rigid unit of U-shaped cross-section having a main body portion with a bottom wall and opposing side walls, and having self-formed end closures are disclosed. The unit forms a plurality of end closures, at each end of the packaging container. Each end closure is formed from a plurality of closure panels extending from and adjacent to each end of the main body portion. The main body portion and the plurality of end closures are separated from one another by fold lines.
For purposes of the present disclosure, the package material, although defined as having a U-shaped cross-section is, in fact, formed from a material having a channel-like or squared U-shape having a flat or near-flat bottom wall. The corners may be formed having a radius of curvature (i.e., rounded) or they may be formed having relatively sharp angles. However, again, for purposes of the present disclosure, the container material is referred to as “U-shaped.”
The main body portion and the plurality of closure panels all have straight-cut corners at their junctions with each other. Some closure panels are configured for folding generally perpendicular to each other and to the main body bottom wall, and others are configured for folding generally parallel to each other and to the main body bottom wall.
In one embodiment, the packaging container is configured to enclose an object with an elevated end (e.g., a support post with an attached asymmetrical flange). One of the end closure's closure panels has approximately the same height as the elevated end of the object to be packaged. Another embodiment is configured to enclose an object with an elevated mid-section (e.g., a crankshaft with integrated cam). Additional closure panels are included with this configuration, to accommodate the “bulge” made by the object's elevated mid-section.
In another embodiment, the packaging container is configured to enclose an object with random elevations. Two of the end closure's closure panels have approximately the same height as the highest elevation of the object to be packaged. A fourth embodiment is configured to enclose two or more dissimilar objects that should be prevented from touching or intermingling during shipping in separate compartments. Another embodiment is configured to combine elements of the four above-referenced configurations, allowing a user to ship objects with elevated ends, elevated mid-sections, or random elevations in separate compartments. A sixth embodiment is configured to enclose one or more objects with a set of two closure panels that are about equal in length to one another.
These and other features and advantages of the present invention will be apparent from the following detailed description, in conjunction with the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The benefits and advantages of the present invention will become more readily apparent to those of ordinary skill in the relevant art after reviewing the following detailed description and accompanying drawings, wherein:
FIG. 1 is a side view of a configuration for a single-piece packaging container with straight-cut end closures constructed in accordance with the principles of the present invention, the container being shown with its first, second, and third closure panels laid open, prior to folding and securing;
FIG. 2 is a side view of the configuration of FIG. 1 , showing the packaging container enclosing an object with an elevated end;
FIG. 3 is a side view of another configuration for single piece packaging container with straight-cut end closures constructed in accordance with the principles of the present invention, the container being shown with its first, second, and third closure panels laid open, prior to folding and securing;
FIG. 4 is a side view of the configuration of FIG. 3 , showing the packaging container enclosing an object with an elevated mid-section;
FIG. 5 is a side view of another configuration of a single piece packaging container with straight-cut end closures constructed in accordance with the principles of the present invention, the container being shown with its first and second closure panels laid open, prior to folding and securing;
FIG. 6 is a side view of the configuration of FIG. 5 , showing the packaging container enclosing an object with random elevations;
FIG. 7 is a front view of the configuration of FIG. 5 along line 7 - 7 , showing the packaging container enclosing an object with random elevations;
FIG. 8 is a side view of another configuration of a single piece packaging container with straight-cut end closures constructed in accordance with the principles of the present invention, the container being shown with its first, second, and third closure panels laid open, prior to folding and securing;
FIG. 9 is a side view of the configuration of FIG. 8 , showing the packaging container enclosing two objects in two separate compartments;
FIG. 10 is a side view of another configuration of a single piece packaging container with straight-cut end closures constructed in accordance with the principles of the present invention, the container shown enclosing two objects, one with an elevated end, and the other with an elevated mid-section, in two separate compartments;
FIG. 11 is a side view of another configuration of a single piece packaging container with straight-cut end closures constructed in accordance with the principles of the present invention, the container being shown with its first and second closure panels laid open, prior to folding and securing;
FIG. 12 is a side view of the configuration of FIG. 11 , showing the packaging container enclosing an object;
FIG. 13 is a perspective view of one device for forming the cuts in the packaging container material;
FIG. 14 is a perspective view of one exemplary container having cuts formed therein;
FIG. 15 is a cross-sectional view taken along line 15 - 15 of FIG. 14 , illustrating a pair of embossings formed in the container material for enhanced container formation;
FIG. 16 is a perspective view of the cutter carriage shown with the carriage in the up or loading position;
FIG. 17 is a side view of the cutter carriage of FIG. 16 shown with the carriage moving into the down or cutting position;
FIG. 18 is a partial side view of the cutter shown with a container loaded therein and with the holding pins securing the container within the cutter;
FIG. 19 is a cross-sectional view taken along line 19 - 19 of FIG. 18 ;
FIG. 20 is a partial side view of the carriage;
FIG. 21 is a perspective view of the cutter showing the indexing assembly in the retracted position;
FIG. 22 is a perspective view of the cutter similar to FIG. 21 but showing the indexing assembly in the extended position; and
FIG. 23 is a front view of the cutter showing the scale windows through a lower portion of the carriage and the scale visible therethrough.
DETAILED DESCRIPTION OF THE INVENTION
While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described presently preferred embodiments with the understanding that the present disclosures are to be considered exemplifications of the invention and are not intended to limit the invention to the specific embodiments illustrated.
It should be further understood that the title of this section of this specification, namely, “Detailed Description Of The Invention,” relates to a requirement of the United States Patent Office, and does not imply, nor should be inferred to limit the subject matter disclosed herein.
Referring now to the figures and in particular FIG. 1 , there is shown a packaging container 10 , configured to enclose an object with an elevated end (e.g., a support post with an attached asymmetrical flange) in one of the embodiments of the present invention. The packaging container is formed in a U-shaped cross-section. Preferably, the packaging container is formed from laminated paperboard material. The packaging container includes a main body portion 12 , first closure panels 14 , 16 , second closure panels 18 , 20 , and a third closure panel 22 . The straight-cut first, second, and third closure panels are formed from an extension of the main body portion 12 . The main body portion has a bottom wall 24 and side walls 26 . The first, second, and third closure panels 14 , 16 , 18 , 20 , and 22 , also have bottom walls 28 , 30 , and 32 , and side walls 34 , 36 , and 38 .
The first closure panels 14 , 16 are formed adjacent to and at either end of the main body portion 12 . The side walls 34 of the first closure panels 14 , 16 have first straight-cut corners 40 . The main body side walls 26 also have straight-cut corners 42 , immediately adjacent to the first panels' straight-cut corners 40 . First fold lines or creases 44 can be formed between the main body bottom wall 24 and the firs closure panels' bottom walls 28 at the junctures of the straight-cut corners 42 , 44 to facilitate folding.
The second closure panels 18 , 20 are adjacent to the first closure panels 14 , 16 . The second closure panels 18 , 20 are separated from the first panels 14 , 16 by second fold or crease lines 46 formed between the first closure panels' bottom walls 28 and the second closure panels' bottom walls 30 , parallel to the first fold lines 44 . The side walls 36 of the second closure panels 18 , 20 include first straight-cut corners 48 at the junctures with the first closure panels 14 , 16 . The side walls 34 of the first closure panels 14 , 16 include second straight-cut corners 50 adjacent to the second closure panels 18 , 20 .
The third closure panel 22 is adjacent to one of the second closure panels 18 . The third closure panel 22 is separated from the second panel 18 by third fold or crease lines 52 formed between the second closure panel's bottom walls 30 and the third closure panel's bottom walls 32 , parallel to the first and second fold lines 44 , 46 . The side walls 38 of the third closure panel 22 include straight-cut corners 54 at the junctures with the second closure panel 18 . The side walls 36 of the second closure panel 18 include second straight-cut corners 56 adjacent to the third closure panel 22 .
The height h 26 of the main body side walls 26 is about equal to the heights h 34 , h 36 , and h 38 of the first closure panels side walls 34 , second closure panels side walls 36 , and third closure panels side walls 38 . The length l 14 of one of the first closure panels 14 is approximately equal to the height h 52 of the object 52 (see FIG. 2 ) with an elevated end enclosed within the package 10 . The length l 16 of the other first closure panels 16 is approximately equal to the heights h 20 , h 34 , h 36 , and h 38 of the main body, first closure panels, second closure panels, and third closure panel side walls 20 , 34 , 36 , and 38 .
Referring to FIG. 2 , assembling the package 10 is straightforward and readily carried out. The package 10 is placed on a surface, with the main body 12 , and the first, second, and third closure panels 14 , 16 , 18 , 20 , and 22 , laid out flat. The article to be packaged 58 is placed in the main body portion 12 . The first panels 14 , 16 are then folded upwardly, so that the first panels 14 , 16 are perpendicular to the bottom wall 24 of the main body portion 12 . As the first panels 14 , 16 are folded, their side walls 34 can be inserted between the main body side walls 26 . The second panels 18 , 20 are then folded over, perpendicular to the first panels 14 , 16 , so that the bottom walls 30 of the second panels 18 , 20 lie substantially parallel to the bottom wall 24 of the main body portion 12 . As the second panels 18 , 20 are folded, their side walls 36 can be inserted between the side walls 34 of the first panels 14 , 16 . Finally, the third panel 22 is folded, generally perpendicular to the first closure panels 14 , 16 , generally parallel to the main body bottom wall 24 , and overlapping one of the second closure panels 20 . As the third panel 22 is folded, its side walls 38 can be inserted between the side walls 26 of the main body portion 12 . FIG. 2 shows the package 10 fully assembled and enclosing an object 58 with an elevated end. One of the corners 50 of one of the first closure panels 14 and one of the corners 48 of one of the second closure panels 18 may be trimmed to facilitate package forming.
Another embodiment of the present invention is displayed in FIGS. 3 and 4 , which show a packaging container configuration designed to enclose an object with an elevated mid-section 60 (e.g., a crankshaft with an integrated cam). Similar to the configuration shown in FIGS. 1 and 2 , the packaging container 10 includes a main body portion 12 , first closure panels 14 , 16 , and second closure panels 18 , 20 , but the present embodiment incorporates two third closure panels 22 , 23 instead of one. The lengths l 14 , l 16 of the first closure panels 14 , 16 are approximately equal to the heights h 26 , h 34 , h 36 , and h 38 of the main body, first closure panels, second closure panels, and third closure panel side walls 26 , 34 , 36 , and 38 .
Referring to FIG. 4 , to assemble the package, the main body 12 , and the first, second, and third closure panels 14 , 16 , 18 , 20 , 22 , and 23 are laid out flat on a surface. The article to be packaged 60 is placed in the main body portion 12 . The first panels 14 , 16 are then folded upwardly, so that the first panels 14 , 16 are perpendicular to the bottom wall 24 of the main body portion 12 . As the first panels 14 , 16 are folded, their side walls 34 can be inserted between the main body side walls 26 . The second panels 18 , 20 are then folded over at roughly a 45-degree angle to the first panels 14 , 16 , so that the bottom walls 30 of the second panels 18 , 20 lie at substantially at 45-degree angle to the bottom wall 24 of the main body portion 12 . As the second panels 18 , 20 are folded, their side walls 36 can be inserted between the side walls 34 of the first panels 14 , 16 . Finally, the third panels 22 , 23 are folded, generally at a 45-degree angle to the second closure panels 18 , 20 , parallel to the main body bottom wall 24 , and overlapping one another to accommodate the mid-section bulge of the object 60 . As the third panels 22 , 23 are folded, their side walls 38 can be inserted between the side walls 26 of the main body portion 12 . The second closure panels 18 , 20 may vary in length l 18 , l 20 , but together should always be equal to the length l 12 of the main body portion 12 . FIG. 4 shows the package 10 fully assembled and enclosing an object 60 with an elevated mid-section.
A third embodiment of the present invention is illustrated in FIGS. 5-7 , which show a packaging container configuration designed to enclose an object with random elevations 62 . Similar to the configurations shown in FIGS. 1-4 , the packaging container 10 includes a main body portion 12 , first closure panels 14 , 16 , and second closure panels 18 , 20 , but no third closure panels. The lengths l 14 , l 16 of the first closure panels 14 , 16 are approximately equal to the highest height of the object 62 with random elevations enclosed within the package 10 .
Two additional short slits 64 , 66 are cut into the side walls 26 of the main body portion 12 , creating small support wedges 68 , 70 . The slits 64 , 66 are positioned close to the center of the main body portion side walls 26 , and are spaced approximately two inches apart. The height h 64 , h 66 of the slits is approximately half the height h 26 of the main body portion 12 side walls 26 . Both support wedges 68 , 70 are slightly deformed inward, allowing the second closure panels 18 , 20 to rest upon them (see FIGS. 6 and 7 ) when closed.
FIGS. 6 and 7 show the packaging container 10 as assembled. The main body 12 , and the first and second closure panels 14 , 16 , 18 , and 20 are laid out flat on a surface. The article to be packaged 62 is placed in the main body portion 12 . The first panels 14 , 16 are then folded upwardly, so that the first panels 14 , 16 are perpendicular to the bottom wall 24 of the main body portion 12 . As the first panels 14 , 16 are folded, their side walls 34 can be inserted between the main body side walls 26 . The second panels 18 , 20 are then folded over, perpendicular to the first panels 14 , 16 so that the bottom walls 30 of the second panels 18 , 20 lie substantially parallel to the bottom wall 24 of the main body portion 12 . As the second panels 18 , 20 are folded, their side walls 36 can be inserted between the side walls 34 of the first panels 14 , 16 . The side walls 36 of the second closure panels 18 , 20 rest on the support wedges 68 , 70 formed in the main body side walls 26 . FIG. 6 shows the package 10 fully assembled and enclosing an object 62 with random elevations. FIG. 7 shows a front cut-away view of the package 10 fully assembled and enclosing an object 62 with random elevations.
A fourth embodiment of the present invention is demonstrated in FIGS. 8 and 9 , which show a packaging container configuration designed to enclose two related but dissimilar objects or groups of objects 72 , 74 , which should be prevented from touching or intermixing during shipping. Similar to the configurations shown in FIGS. 3 and 4 , the packaging container 10 includes a main body portion 12 , first closure panels 14 , 16 , second closure panels 18 , 20 , and third closure panels 22 , 23 . The lengths l 14 , l 16 of the first closure panels 14 , 16 and l 22 , l 23 of the third closure panels 22 , 23 are approximately equal to the heights h 20 , h 34 , h 36 , and h 38 of the main body, first closure panels, second closure panels, and third closure panel side walls 20 , 34 , 36 , and 38 .
Referring to FIG. 9 , to assemble the package, the main body 12 , and the first, second, and third closure panels 14 , 16 , 18 , 20 , 22 , and 23 are laid out flat on a surface. The articles to be packaged 72 , 74 are placed on either end of the main body portion 12 . The first panels 14 , 16 are then folded upwardly, so that the first panels 14 , 16 are perpendicular to the bottom wall 24 of the main body portion 12 . As the first panels 14 , 16 are folded, their side walls 34 can be inserted between the main body side walls 26 . The second panels 18 , 20 are then folded over, perpendicular to the first panels 14 , 16 , so that the bottom walls 30 of the second panels 18 , 20 lie substantially parallel to the bottom wall 24 of the main body portion 12 . As the second panels 18 , 20 are folded, their side walls 26 can be inserted between the side walls 34 of the first panels 14 , 16 . Finally the third panels 22 , 23 are folded, generally perpendicular to the second closure panels 18 , 20 and the main body bottom wall 24 , and generally parallel to the first closure panels 14 , 16 . As the third closure panels 22 , 23 are folded, their side walls 38 can be inserted between the side walls 36 of the second closure panels 18 , 20 . When folded, the third closure panels 22 , 23 form a double-thick divider, separating the packaged objects 72 , 74 . The second closure panels 18 , 20 may vary in length l 18 , l 20 , but together should always be equal to the length l 12 of the main body portion 12 . FIG. 9 shows the package 10 fully assembled and enclosing objects 72 , 74 that should be prohibited from touching or intermixing during shipping.
The present configuration additionally may be used as a packaging container with a built-in spacer. Frequently, objects are somewhat shorter than the length of available shipping containers. For example, it would be economical to ship an object four feet to five-and-a-half feet in length in a six-foot-long standard box. Usually, such an object would be randomly placed in a too-large box and covered with foam fillers or other, similar protective materials. However, fillers may compress, leak, or shift, leaving shipped objects without protection. Conversely, using the packaging container 10 described in FIGS. 8 and 9 , the short object could be placed against one end of the container 10 , and then custom enclosed into a segregated side, with a double-thick divider separating it from the other, fully-formed, hollow chamber. The present configuration allows shippers to customize packaging containers by creating a segregated, perfectly-sized compartment within a standard-sized box.
A fifth embodiment of the present invention is demonstrated in FIG. 10 , which shows a packaging container configuration designed to combine all four of the above described configurations. As described in detail above, the packaging container 10 exhibited in FIG. 10 can accommodate and object with an elevated end 58 , an object with an elevated mid-section 60 , an object with random elevations 62 (not shown), and objects that must be segregated during shipping 72 , 74 . To accomplish the composition of FIG. 10 , the side of the main body portion 12 containing the object with an elevated end requires four closure panels ( 14 , 18 , 22 , 76 ), and the side of the main body portion 12 containing the object with an elevated mid-section requires five closure panels ( 16 , 20 , 23 , 78 , 80 ). All of the closure panels are folded and inserted according to the above descriptions, resulting in completely object coverage and a double thick divider. If an object with random elevations 62 was packaged as part of a combination container, four closure panels would be required for its end of the container.
A sixth embodiment is presented in FIGS. 11 and 12 , which show a packaging container configuration designed to enclose one or more objects 82 . Similar to the configuration shown in FIGS. 5 and 6 , the packaging container 10 includes a main body portion 12 , first closure panels 14 , 16 , and second closure panels 18 , 20 , but no third closure panels. The lengths l 14 , l 16 of the first closure panels 14 , 16 are approximately equal to the heights h 26 , h 34 , and h 36 of the main body, first closure panels, and second closure panels side walls 26 , 34 , and 36 . In that this is a “seamless” container, the second closure panel 20 has a length l 20 that is about equal to the length l 12 of the main body portion 12 .
FIG. 12 shows the packaging container 10 as assembled. The main body 12 , and the first and second closure panels 14 , 16 , 18 , and 20 are laid out flat on a surface. The article to be packaged 82 is placed in the main body portion 12 . The first panels 14 , 16 are then folded upwardly, so that the first panels 14 , 16 are perpendicular to the bottom wall 24 of the main body portion 12 . As the first panels 14 , 16 are folded, their side walls 34 can be inserted between the main body side walls 26 . The second panels 18 , 20 are then folded over, perpendicular to the first panels 14 , 16 so that the bottom walls 30 of the second panels 18 , 20 lie substantially parallel to the bottom wall 24 of the main body portion 12 . As the second panels 18 , 20 are folded, their side walls 36 can be inserted between the side walls 34 of the first panels 14 , 16 . In that the length l 20 is about equal to the length l 12 of the main body portion 12 , the container appears to be “seamless”; that is, the container appears to be without a mid container seam across the top (which is panel 20 ) or the main body portion 12 .
Referring now to FIG. 13 , there is shown one cutter device 102 for forming or making the side wall cuts in the container 10 material. The cutter 102 includes a frame 104 , a container support 106 and a carriage 108 that moves in a reciprocating manner in the direction of the cut. As illustrated, the container support 106 includes beam 110 on which are mounted stand-offs 112 for receiving the container 10 . The container 10 rests on the stand-offs 112 to define a base surface 114 and side surfaces 116 for supporting the container 10 as it is cut.
The carriage 108 is configured to move down and up, toward and away from the container 10 as it rests on the support 106 . The carriage 108 is configured to support a pair of rotary cutters 118 , for example, circular saws, one each mounted a carriage side wall 120 . In this manner, as the carriage 108 moves up and down (as indicated by the arrow at 122 ), the cutters 118 move up and down for cutting through the side walls of the container 10 .
As best seen in FIGS. 16 and 20 , a cutting anvil 124 is positioned on the support 106 at the location at which the cutters 118 move into the container 10 . The anvil 124 includes channels 126 formed in the side walls to permit movement of the cutters 118 through the container side walls without contacting the anvil 124 side walls. In addition, the anvil 124 can include a raised portion or ridge 128 that extends transversely across the top wall 129 of the anvil 124 between the side wall channels 126 .
In a present embodiment, the carriage 108 is moved up and down by action of a drive 130 , such as the exemplary pneumatic cylinder. The pneumatic cylinder 130 is mounted to an upper carriage plate 132 to which the carriage side plates or walls 120 (mounting the cutters 118 to the carriage 108 ) are mounted. In this manner, reciprocating movement of the cylinder 130 moves the carriage 108 which moves the cutters 118 into and out of contact with the container 10 . Other drives will be recognized by those skilled in the art and are within the scope and spirit of the present invention.
The cutters 118 are fixedly mounted to the carriage 108 to permit readily moving the carriage 108 up and down for cutting the container side walls. To facilitate holding or maintaining the container 10 in place as the carriage 108 moves downward and the cutters 118 move into contact with the container side walls, a pair of holding pins 134 can be mounted to the support 106 . The holding pins 134 move outwardly to hold the container 10 side walls against the carriage side surfaces 116 as the cutters 118 make contact with the container 10 . In a present embodiment, the pins 134 are pneumatically actuated.
To further provide a “clean” container 10 appearance, the cutting device 102 is configured to emboss the container top or bottom wall 24 at fold or crease lines between the side wall cuts. As seen in FIGS. 15 and 19 , the upper carriage plate 132 includes a transverse groove 136 formed therein that corresponds to the top wall ridge 128 . In this manner as the carriage 108 moves down to move the cutters 118 into contact with the container 10 side walls, the upper plate 132 “presses” the container top (or bottom) wall 24 between the upper carriage plate 132 and the support top wall 129 , sandwiching the container wall 24 between the ridge 128 and the groove 136 , thus “embossing” a groove into the wall 24 .
To provide the appropriate spacing between cuts (e.g., to form appropriate sized panels 12 , 14 , 16 ), the cutter device 102 can include an indexing assembly 138 . The indexing assembly 138 includes a drive 140 , such as the exemplary pneumatic cylinder, to move the container 10 a desired distance once a first cut is made to position the container 10 for a second cut. To effect movement, the cylinder 140 cycles between a retracted position ( FIG. 21 ) and an extended position ( FIG. 22 ). The extension length or distance of the cylinder 140 can be set to correspond to the desired distance between cuts.
As seen in FIG. 23 , the carriage 108 can include openings or windows 142 in a side thereof that overlie a scale 144 that is applied to the support beam 110 . In this manner, the distance along the length of the container 10 at which the cut or cuts are formed can be precisely set and controlled.
All patents referred to herein, are hereby incorporated herein by reference, whether or not specifically done so within the text of this disclosure.
In the present disclosure, the words “a” or “an” are to be taken to include both the singular and the plural. Conversely, any reference to plural items shall, where appropriate, include the singular.
From the foregoing, it will be observed that numerous modifications and variations can be effected without departing from the true spirit and scope of the novel concepts of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated is intended or should be inferred. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims. | Configurations for a packing container formed from a single, preformed, rigid unit of generally U-shaped cross-section are disclosed. One configuration utilizes three end closures to enclose an object with an elevated end. Another configuration employs three end closures to enclose an object with an elevated mid-section. A third configuration uses two end closures to enclose an object with random elevations. With three end closures, a fourth configuration encloses two or more dissimilar objects in separate compartments. The fourth configuration is especially useful for items that should be prevented from touching or intermingling during shipping. A fifth configuration combines elements of the other four configurations, allowing a user to ship objects with elevated ends, elevated mid-sections, or random elevations in separate compartments. A sixth configuration encloses one or more objects with two end closures that are about equal in length to one another. A device for forming the container is also disclosed. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to an electric cylinder for actuating a door lock which can attach to the existing lock for opening and shutting the door.
[0003] 2. Description of Related Art
[0004] The existing lock for opening and shutting the door is generally designed to use a key so that if the key has been carried and lost or is missing, picking permits the lock to be unlocked by inserting a special tool or a picking tool into the keyhole of the lock. If a lock without a keyhole is attached to the door, additional equipment which has high reparation costs is required.
[0005] Recently, a lock structure is proposed to prevent unlawful unlocking without using a proper key, for example, as disclosed in JP-A-2002-276215, however these locks must be provided on the door when it is built, or the door must be reconstructed.
SUMMARY OF THE INVENTION
[0006] Problem to be Solved by the Invention:
[0007] It has been desired that the picking can be completely prevented by detaching the existing door lock and attaching the electric cylinder for receiving an electric signal to the door lock so as to attach easily to the existing door lock the electric cylinder which permits code operation or remote operation for sending the electric signal.
[0008] It is an object of this invention to provide an electric cylinder for actuating a door lock which may be easily attached to the existing door lock to prevent the picking completely, and an electric cylinder door lock not having a keyhole.
[0009] Means for Solving the Problems:
[0010] The electric cylinder for actuating a door lock of this invention is characterized in that a motor shaft is displaced by the operation of a motor to associate a rotary can with a disc, one end of said motor shaft is accommodated in a hole portion which is formed in the bottom of the case, all electric cylinder parts are accommodated in the case, said rotary can is divided into two upper and lower parts which are always associated with each other, said disc is put displaceably with a spring in the case, the electrode of said motor is changed to extend and contract said motor shaft, and the tailpiece is associated with the operation of the extension and contraction to actuate a dead bolt.
[0011] According to the electric cylinder for the door lock of this invention, it is to provide considerably a convenient electric cylinder which may be easily attached to the existing door lock so as to use a telephone, to provide the remote operation from one's room of house or apartment, or to provide a locking and unlocking lock which may be operated with a fingerprint and a tenkey.
[0012] According to the electric cylinder for the door lock of this invention, wiring cables of a motor for extending and contracting the shaft, or a stepping motor are disposed at the position regardless of the rotation of the rotary dish plate, so that the cylinder may be rotated at an angle of more than 360° to correspond to foreign locks such as European locks and the like.
[0013] The electric cylinder for the door lock of this invention is characterized in that the electric cylinder may be easily attached to the existing door lock by clamping bolts from the front side of the existing door to provide the electric cylinder door locks not having a keyhole.
SIMPLE DESCRIPTION OF DRAWINGS
[0014] [0014]FIG. 1 shows the whole exploded view of the electric cylinder;
[0015] [0015]FIG. 2 shows a perspective view where all parts of the electric cylinder are accommodated in the case to be assembled and associated with the dead bolt of the existing door;
[0016] [0016]FIG. 3 shows a plan view where the electric cylinder is set to the existing door opening and shutting lock;
[0017] [0017]FIG. 4 shows a partial perspective view of upper and lower rotary can parts for the motor provided with a screwed shaft; and
[0018] [0018]FIG. 5 shows a partial perspective view of the whole exploded electric cylinder provided with a motor and a rotary dish plate to rotate the electric cylinder at an angle of more than 360 degrees.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] The preferred embodiments of the invention will be illustrated hereinafter with reference to the accompanying drawings.
[0020] [0020]FIG. 1 shows the exploded parts of the whole of the electric cylinder in the perspective view. The electric cylinder mechanism is illustrated in the exploded perspective view. Plural stand poles 2 along which springs 3 are winded, are fixed to the bottom of a case 1 . A disc 4 is secured to the plural poles 2 by rings 5 when the plural poles 2 are passed through holes 18 of the disc 4 . A hollow pole 30 provided with the bottom of the case 1 is inserted into a central hole 32 of the disc 4 .
[0021] A shaft 9 associated with a motor 8 is inserted in a central hole 28 of the bottom of a lower rotary can part 6 , and when the lower rotary can part 6 and the motor 8 are connected by stop rings 34 and 35 set in two grooves 33 notched on the shaft 9 , the shaft 9 is entered in a hole 31 of the central hole 30 provided on the bottom of the case 1 to arrange the motor 8 and the case 1 in a linear relation. This motor 8 is a stepping motor which can extend and contract the shaft 9 in the arrow directions 50 and 45 .
[0022] The motor 8 is integrated with a stationary can 15 . The cables 39 and 40 are drawn from holes 17 of the stationary can 15 through the cable through grooves of a projected portion. The motor 8 is clamped by a stationary metal fitting 10 and attached to the stationary can 15 by bolts 11 . An upper rotary can part 13 is integrated through a cylinder part 38 with a tailpiece 14 which is associated with a dead bolt for a door lock. The upper rotary can part 13 is secured to the stationary can 15 by clamping a ring to a groove formed on the cylinder part 38 to pass the tailpiece 14 through a central hole 16 opened in the stationary can 15 .
[0023] The stationary can 15 integrated with the upper rotary can part 13 by a clamping ring 20 is pushed by means of a ring plate 55 and accommodated in the case 1 , because bolts 22 are secured through the hole of the ring plate 55 into screwed holes 27 of the case 1 . Then, the ring plate 55 is set on a step face 37 of the stationary can 15 to be completely integrated with the case 1 . The stationary can 15 of the integrated electric cylinder is passed through a central hole 53 of a decorative seat block 25 and integrated with the decorative seat block 25 to contact the surface 41 of the decorative seat block 25 with the door surface. An inner case 21 for a door lock is attached to the stationary can 15 by inserting bolts 13 through a dead bolt 24 for the door lock into the screwed holes 36 of the stationary can 15 .
[0024] The electric operation will be illustrated with reference to the accompanying drawings; the two cables 39 and 40 for a power source are used in the motor 8 . When the positive electrode is connected to the cable 39 and the negative electrode is applied to the cable 40 , the shaft associated with the motor 8 is displaced in the direction of the arrow 50 to push the rotary lower can part 6 associated with the shaft 9 to enter a projection 7 integrated with the rotary lower can part 6 into a number of holes 26 opened on the disc 4 accommodated in the case 1 .
[0025] At this state, when the case is turned by hand, the rotary lower and upper can parts 6 and 13 are associated with each other and turned together through groove faces 42 to transmit a turning movement to the tailpiece 14 , so that the dead bolt 24 is actuated to provide an unlocking state. However, when the dead bolt 24 is contacted to a socket of the door (not shown), the dead bolt 24 is not actuated to the normal position. In this case, as the cylinder case 1 is continued to turn by hand, springs 3 are contracted, and when a further constant power is applied to the engaging portions, or projections 7 of the rotary can part 6 and holes 26 of the disc 4 , the projections 7 are detached from the holes 26 because at least one of the projection 7 and the hole 26 is provided with the inclined angle, so that the cylinder case 1 is turned by hand force to generate a clicking sound (click-clack).
[0026] When one cable 39 is connected to the negative electrode and the other cable 40 is connected to the positive electrode, the shaft 9 of the motor 8 is returned in the arrow direction 45 to detach the rotary lower can part 6 from the disc 4 so as to permit them both to be unassociated. The spring 3 is functioned to escape the pushing movement because the disc 4 is pushed toward the bottom of the case if the rotary lower can part 6 may be badly engaged with the disc while the shaft is displaced in the arrow direction 50 . Moreover, during locking, plural holes 26 opened on the disc 4 are not engaged and connected with the projections 7 integrated with the rotary lower can part 6 , so as to always provide the free-rotation of the cylinder case 1 .
[0027] [0027]FIG. 2 and FIG. 3 show a perspective view and a plan view for the assembled state where a dead bolt for opening and shutting the door lock is associated with the cylinder case 1 for accommodating all parts of the electric cylinder. The opening and shutting is carried out by turning an opening and shutting knob 44 with fingers to displace the dead bolt 24 within a door.
[0028] When the dead bolt 24 is inserted through a door dead bolt guide 19 into a locking hole provided on the wall, the door is locked. The knob 44 is turned from the locking hole so as to provide the unlocking state. The dead bolt guide 19 is fixed to the end face of the door by bolt 54 .
[0029] [0029]FIG. 4 shows a partial perspective view of rotary upper and lower can parts for using a screwed motor shaft. The shaft 9 of the motor 8 is screwed and the hole 28 of the lower can part 6 is screwed, so that when the shaft 9 is rotated, the rotary lower can part 6 engaged with the shaft 9 is advanced at the positive electrode to be associated with the disc 4 . As the negative electrode is connected to the motor, the rotary lower can part 6 is detached from the disc 4 , or the shaft 9 of the motor 8 is not extended and contracted. The shaft 9 and the hole 28 of the rotary lower can part 6 are respectively provided with screws, so that the rotary lower can part 6 is reciprocated and associated with the disc 4 .
[0030] [0030]FIG. 5 shows a partial perspective view of a whole exploded electric cylinder provided with the motor 8 and the rotary dish plate 46 , the electric cylinder may be rotated under an angle of more than 360 degrees.
[0031] The shaft 9 of this stepping motor 8 is disposed in parallel to the tailpiece assembly and contacted with the surface of the rotary dish plate 46 . One side of the rotary dish plate 46 is provided with a movable rectangular rod 51 and the other side of the rotary dish plate 46 is provided with a cylindrical rod 52 which is inserted through a spring 43 into a hole 31 of a hollow pole 30 . The one movable rectangular rod 51 is associated with a cylinder 47 having a slide hole 49 of the tailpiece assembly in the piston-cylinder relation.
[0032] The tailpiece 14 associated with the rotary dish plate 46 is disposed in parallel to the stepping motor 8 , so that the cables 39 and 40 drawn from the stepping motor 8 do not hinder the rotation of rotary dish plate 46 . Accordingly, the electric cylinder may be rotated at the more than 360 degrees. After the tailpiece 14 is inserted through the hole 16 into the rotary cylinder 15 , when the ring 20 is clamped in an annular groove 48 provided on the cylinder 17 of the tailpiece assembly, the tailpiece assembly is fixed in the rotary cylinder 15 . The disc 4 , the rotary dish plate 46 , the tailpiece assembly and the rotary cylinder 15 are disposed in a linear relation and accommodated in the case 1 .
[0033] When the one cable 39 is connected to the positive electrode and the other cable 40 is connected to the negative electrode, the shaft 9 associated with the motor 8 is displaced in the arrow direction 50 as shown in FIG. 1, to push the rotary dish plate 46 associated with the shaft 9 , so that the projections 7 integrated with the rotary dish plate 46 are entered into plural holes 26 opened on the disc 4 which is accommodated in the cylinder case 1 . In this state, turning the cylinder case 1 by hand, the turning movement permits the disc 4 and the rotary dish plate 46 to be associated with each other and transmitted through the rectangular rod 51 of the rotary dish plate 46 and the slide hole 59 provided in the cylinder 47 of the tailpiece assembly to the tailpiece 14 , so that the dead bolt 24 is actuated to provide an unlocked state. However, when the dead bolt 24 is contacted to a socket of the door (not shown), the dead bolt 24 is not actuated to the normal position. In this case, as the cylinder case 1 is continued to turn by hand, springs 3 are contracted, and when a further constant power is applied to the engaging portions, or projections 7 of the rotary dish plate 46 and holes 26 of the disc 4 , the projections 7 are detached from the holes 26 because at least one of the projections 7 and holes 26 is provided with the inclined angle, so that the cylinder case 1 is turned by hand force to generate a clicking sound (click-clack).
[0034] Effects of the Invention:
[0035] According to this invention, the electric cylinder may be easily attached to the existing door lock to prevent picking completely.
[0036] This invention is to provide the electric cylinder door lock not having a keyhole with a means of easily attaching the cylinder to the existing door opening and shutting lock from the front side of the door by clamping the bolts. According to the electric cylinder for actuating the door lock of this invention, the cables of the stepping motor do not hinder the rotation of the rotary dish plate which is based on the locking and unlocking operations for carrying out the rotation of the electric cylinder, so that this electric cylinder may be adapted to use in foreign cylinder locks such as European cylinder locks so as to turn it at an angle of more than 360 degrees.
[0037] According to the electric cylinder for actuating the door lock of this invention, the electric cylinder may be easily attached to the existing door locks. Using the telephone or the remote operation from one's room, and moreover using the fingerprints and the tenkeys, the electric cylinder may be used in the locking and unlocking lock.
[0038] According to this invention, during unlocking operation when a further constant force is applied to this electric cylinder, the associated engagement of the rotary can or dish plate and the disc is detached from each other, so that the cylinder case may be free-rotated in manual operation.
DESCRIPTION OF REFERENCE NUMBERS
[0039] [0039] 1 . . . a cylinder case
[0040] [0040] 2 . . . stand poles
[0041] [0041] 3 . . . springs
[0042] [0042] 4 . . . a disc
[0043] [0043] 5 . . . clamping rings
[0044] [0044] 6 . . . a lower rotary can part
[0045] [0045] 7 . . . projections
[0046] [0046] 8 . . . a motor
[0047] [0047] 9 . . . a shaft
[0048] [0048] 10 . . . a clamping metal fitting
[0049] [0049] 11 . . . bolts
[0050] [0050] 12 . . . a cable passing groove
[0051] [0051] 13 . . . an upper rotary can part
[0052] [0052] 14 . . . a tailpiece
[0053] [0053] 15 . . . a stationary can
[0054] [0054] 16 , 17 , 18 . . . holes
[0055] [0055] 19 . . . a dead bolt guide for a door
[0056] [0056] 20 . . . a clamping ring
[0057] [0057] 21 . . . an inner case for a lock
[0058] [0058] 22 , 23 . . . bolts
[0059] [0059] 24 . . . a dead bolt
[0060] [0060] 25 . . . a decorative seat block
[0061] [0061] 26 . . . a number of holes
[0062] [0062] 27 . . . a hole
[0063] [0063] 28 . . . a central hole of a lower rotary can part
[0064] [0064] 29 . . . engaging grooves
[0065] [0065] 30 . . . a hollow pole
[0066] [0066] 31 . . . a hole of a hollow pole
[0067] [0067] 32 . . . a central hole
[0068] [0068] 33 . . . grooves of a shaft
[0069] [0069] 34 . . . a clamping ring
[0070] [0070] 35 . . . a clamping ring
[0071] [0071] 36 . . . a screwed hole
[0072] [0072] 37 . . . a set portion of a stationary can part
[0073] [0073] 38 . . . a cylinder portion
[0074] [0074] 39 , 40 . . . cables for positive and negative electrodes
[0075] [0075] 41 . . . a surface of a decorative seat block
[0076] [0076] 42 . . . a groove face
[0077] [0077] 43 . . . a spring
[0078] [0078] 44 . . . an opening and shutting knob
[0079] [0079] 45 . . . an arrow
[0080] [0080] 46 . . . a rotary dish plate
[0081] [0081] 47 . . . a tailpiece cylinder
[0082] [0082] 48 . . . an annular groove of a tailpiece cylinder
[0083] [0083] 49 . . . a slide hole of a tailpiece cylinder
[0084] [0084] 50 . . . an arrow
[0085] [0085] 51 . . . a rectangular rod of a rotary dish plate
[0086] [0086] 52 . . . a cylindrical rod of a rotary dish plate
[0087] [0087] 53 . . . a central hole of a decorative seat block
[0088] [0088] 54 . . . bolts
[0089] [0089] 55 . . . a ring plate | Problems of the Invention:
It is to provide an electric cylinder for actuating a door lock which may be easily attached to the existing door lock to prevent picking completely, and an electric cylinder door lock not having a keyhole.
Means for Solving the Problems:
The electric cylinder for actuating a door lock of this invention is characterized in that a motor shaft is displaced by the operation of a motor to associate a rotary can with a disc, one end of said motor shaft is accommodated in a hole portion which is formed in the bottom of the case, all electric cylinder parts are accommodated in the case, said rotary can is divided into two upper and lower parts which are always associated each other, said disc is put displaceably with a spring in the case, the pole of said motor is changed to extend and contract said motor shaft, and the tailpiece is associated with the operation of the extension and contraction to actuate a dead bolt. | 4 |
TECHNICAL FIELD
[0001] The invention relates to a method of separably coupling a propulsion module dedicated to flight and a module dedicated to carriage, the coupling of these modules forming an aircraft. The invention also relates to a modular aircraft able to implement such a method.
[0002] The invention applies to the aeronautical field. Conventionally, aircraft comprise propulsion structures dedicated to flight—flight deck, engines, wings and tail unit—and structures dedicated to the carriage of passengers and/or goods—fuselage and hold. The invention relates to the connection between these structures.
PRIOR ART
[0003] An aircraft is conventionally a single cell structured simultaneously to provide propulsion/lift and to carry passengers and/or goods.
[0004] All the operating cycles: flight, maintenance, overhaul, embarkation/loading, disembarkation/unloading, etc. have an impact on the aircraft as a whole.
[0005] The main problem is that the entire aircraft is tied up throughout all of the phases of operation of an aircraft cycle on the ground and, as a result, most of the phases are sequential and cannot be performed in parallel. Thus, the cycle remains incompressible, despite every effort made at optimizing the time spent on each of these phases.
[0006] The concept of separating the flying part and the carriage part is known. The approach was developed notably by Lockheed and described for example in pioneering patents U.S. Pat. No. 2,388,380, U.S. Pat. No. 2,577,287 or U.S. Pat. No. 2,683,005, or even in alternative forms described in patents U.S. Pat. No. 3,361,396 or U.S. Pat. No. 4,379,533. This approach involves providing an assembly between the two modules—propulsion and carriage—that makes it possible to reconstruct an overall structure similar to that of a conventional aircraft structure, with a carriage module situated under or on the module dedicated to flight.
[0007] These solutions do not allow the creation of a simple, dependable and quick disconnectable coupling between the modules. In addition, aerodynamic constraints are not met because of the discontinuities between the aerodynamic envelopes of the modules: turbulence is thus created in flight and this has the result of creating significant drag. Fuel consumption is thereby appreciably increased.
SUMMARY
[0008] The invention seeks to get around these disadvantages by proposing two connections, an axial connection and a radial connection, between the two modules to form a central cell of continuous form. This configuration is then consistent with the aerodynamic constraints having a drag which is similar to, or even better than, that of a conventional present-day aircraft.
[0009] More specifically, one subject of the present invention is a method of separably coupling a propulsion module dedicated to flight, incorporating avionic equipment—wing structures assembly, flight deck, flight controls, drive, tail unit—and a module dedicated to the carriage of passengers and/or goods, the coupling of these modules forming a modular aircraft. This method consists in creating the modules around an external form with overall continuous curvature extending longitudinally along a main axis and having complementary tubular coupling end parts. It then consists in axially coupling the coupling ends of the modules aligned along a longitudinal axis coinciding with the main axes using disconnectable mechanical connections. A longitudinal connection is formed axially and a connection is formed radially so that continuity of external form occurs at these connections, the propulsion module being positioned behind the carriage module in the conventional direction of travel of the aircraft. The wing structure of the propulsion module comprises two opposite sweeps which are connected at the end and between the disconnectable mechanical connections.
[0010] Advantageously, the avionic equipment of the propulsion module—flight deck, flight controls, wing structure assembly, drive, tail unit—is positioned according to the requirements for balancing in order to observe the laws of mechanics of flight of the modular aircraft once it has been assembled.
[0011] This modular nature allows the use of several carriage modules for one and the same propulsion module. It is thus possible to get around the need of making the same aircraft up using the same modules each time, thus improving the flight cycle: the carriage module can be prepared in advance of the phase of use, allowing a significant time saving. In addition, the maintenance cycles involving the carriage module are also optimized because they can be performed as a parallel task, and the propulsion module operating time is optimized for reduced operating costs. In particular, the time spent parked on the ground is reduced to a minimum. In addition, the times spent pressurizing and depressurizing the carriage module can be evened out over time.
[0012] Preferably, the carriage module is disconnected as soon as the aircraft lands and is transported to a disembarkation station of the airport, thus allowing a new module to be reconnected to the same propulsion module immediately, ready for a new flight.
[0013] According to advantageous embodiments:
[0014] the distance between the wing structure sweeps is set to minimize the flow of load between the wing structure and the propulsion module; that being so, the flow of load absorbed is substantially less than the load absorbed in the current design in which the wings are embedded in the fuselage of an aircraft—by the first rib of the central section—because the lever arm, which passes on the fixed-end bending moment between the wing structure and the fuselage of a conventional aircraft, is thereby appreciably lengthened;
[0015] the carriage module has an oblong external fuselage of a shape and length that are suited to the type of carriage—passengers and/or goods—and to the type of flight—long-haul or medium-haul—the shape of the fuselage making it possible to define substantially the same center of gravity while at the same time varying the capacity to carry goods and/or passengers, the axial and radial connections making it possible to achieve an interchangeable coupling between one propulsion module and various carriage modules;
[0016] the external shape of the fuselage is dimensioned so that it too, in addition to the wing structure of the propulsion module, contributes to creating the lift of the modular aircraft and thus improving the overall balance;
[0017] the external shape of the fuselage of the carriage module is that of an ogive in order to improve drag during flight.
[0018] The invention also relates to a modular aircraft able to implement such a method. This modular aircraft comprises a propulsion module dedicated to flight, combining avionic equipment—wing structures assembly, flight deck, flight controls, engines, tail unit—and a module dedicated to the carriage of passengers and/or goods, these modules being coupled to one another by disconnectable mechanical means. The modules comprise external cells extending longitudinally along a main axis and having tubular end parts of the same outline in the region of two disconnectable-coupling means—one axial-coupling means which extends axially to keep an end face of the propulsion module against an end face of the carriage module, these complementary faces extending radially, and one radial-coupling means which extends radially to keep an end face of the propulsion module against an end face of the carriage module, these complementary faces extending longitudinally—so as to form a continuous continuation of external form at the coupling means, the propulsion module being positioned behind the carriage module in the conventional direction of travel of the aircraft. The wing structures assembly of the propulsion module comprises two wing structures having opposite sweeps which are connected at the end and by a longitudinal connecting spar extending between the disconnectable-coupling means.
[0019] According to certain preferred embodiments:
[0020] said end faces are substantially planar;
[0021] the wing structures assembly is made up of an upper wing structure, positioned forward of a lower wing structure which supports the engine and comprises two symmetric wings which are embedded in the propulsion module under the flight deck, and the upper wing structure extends above the carriage module and comprises a central portion which is extended longitudinally by the connecting spar and is embedded in a complementary portion of the carriage module, these portions having the complementary faces on which the radial-coupling means are mounted;
[0022] said complementary faces of said portions are planar, the longitudinal complementary face of the carriage module forming a flat on the carriage module;
[0023] a retractable front landing gear is mounted on the carriage module and a retractable rear landing gear is mounted on the propulsion module;
[0024] at least one additional catching element is mounted in a rear position of the carriage module and can be coupled disconnectably to a catching element mounted on a vehicle that drives the carriage module along on the ground, the catching elements forming a disconnectable-coupling means;
[0025] each of the axial-coupling means and radial-coupling means consists of at least one disconnectable element, particularly a spigot, combined with a retractable locking means arranged in a housing.
DESCRIPTION OF THE DRAWINGS
[0026] Further details, features and advantages of the present invention will become apparent from a study of the non-limited description which follows, with reference to the attached figures which respectively depict:
[0027] FIGS. 1 a and 1 b: perspective overall views of two examples of a modular aircraft according to the invention comprising a module intended for the carriage of passengers and of goods respectively;
[0028] FIGS. 2 a and 2 b : perspective views of the passenger-carriage and goods-carriage modules corresponding to FIGS. 1 a and 1 b respectively;
[0029] FIG. 3 : a side view of the two modules of one example of modular aircraft according to the invention, these being positioned along one and the same axis so that they can be coupled;
[0030] FIG. 3 a : a view in cross section of the means of disconnectable attachment of the passenger carriage module according to FIG. 3 to a vehicle that drives it along on the ground;
[0031] FIG. 3 b: a view in cross section of one example of a mounting of a spigot of the axial-coupling means of the carriage module according to FIG. 3 ;
[0032] FIG. 4 : a half view from the front of the propulsion module according to FIG. 3 ; and
[0033] FIGS. 5 a and 5 b , a side view and a view from above of the modular aircraft of FIG. 3 after the modules have been coupled.
DETAILED DESCRIPTION
[0034] In this text, the qualifiers “front”, “rear”, “upper” and “lower” or their equivalents, relate to elements which are positioned in relation to an aircraft in conventional movement. The qualifiers “transverse”, “longitudinal”, “radial” denote positionings in relation to the main dimension of an aircraft extending along an axis X′X.
[0035] With reference to the overall views of FIGS. 1 a and 1 b, two examples of a modular aircraft la and lb according to the invention have been illustrated. These aircrafts have one and the same propulsion module 2 coupled to the rear of a module 3 a for the carriage of passengers and their luggage ( FIG. 1 a ) or of a module 3 b for the carriage of goods ( FIG. 1 b ), along a main axis X′X. The aircraft and its constituent modules exhibit symmetry with respect to a central plane Ps which, when the aircraft or the modules are on the ground, is vertical. The modules 2 , 3 a and 3 b have central external forms 20 , 30 a, 30 b of overall continuous curvature. The interchangeable nature of the modules means that the operating cycles for operating a fleet of aircraft can be optimized.
[0036] The propulsion module 2 incorporates the avionic equipment dedicated to flight and flight control around the central tubular cell 20 : a double wing structure 4 , engines 5 a, 5 b, a flight deck 6 , flight controls (built into the electronic cabinets in the hold and not visible in the figures), and a steering tail unit 7 arranged at the rear of the tubular cell 20 .
[0037] The double wing structure 4 is made up of an upper wing structure 4 a and of a lower wing structure 4 b which extend transversely to the central cell 20 and are jointed together at their ends 40 . The length of the connections between the wing structures 4 a, 4 b is reduced because of the sweeps formed by these wing structures. The structural bracing of these sweeps stiffens the reaction to the cantilever effect between the built-in end where the lower wing structure 4 b is embedded in the central cell 20 and the coupling of the top wing structure 4 a to the carriage module 3 a or 3 b. In addition, vertical winglets 4 c are provided at the tips of the wings to contribute to weakening the wing tip vortex effect and reduce the drag of the aircraft.
[0038] The upper wing structure 4 a, arranged forward of the lower wing structure 4 b, comprises two wings 40 a which form a sweep bending toward the front “Av” of the aircraft and are connected by a central portion 41 . This central portion 41 is extended longitudinally by a connecting spar 42 between the upper wing structure 4 a and a radial end face 22 of the central tubular cell 20 of the propulsion module 2 . This spar provides reinforcement and balances structural loading. In addition, the length of this spar is determined so that the distance between the wing structure sweeps minimizes the absorption of the flow of load between the wing structure and the propulsion module.
[0039] The lower wing structure 4 b supports the engines 5 a, 5 b and that makes it possible to reduce the noise impact on the ground during take off or landing phases. This lower wing structure 4 b is made up of two symmetric wings 40 b which form a sweep bending toward the rear “Ar” of the aircraft. The length of the connections between the wing structures 4 a, 4 b is reduced because of the sweeps. The wings 40 b of the lower wing structure 4 b are embedded laterally in the central cell 20 under the flight deck 6 . A calculator of a center of gravity (not depicted) assists with balancing the propulsion module by managing the mass of fuel contained in the upper wing structure 4 a compared with that contained in the lower wing structure 4 b.
[0040] The carriage module 3 a or 3 b extends longitudinally along the same axis X′X as the propulsion module 2 and to the front of this same module 2 . The front 31 of the carriage modules 3 a, 3 b advantageously has the shape of an ogive providing aerodynamic optimization for best penetration through the air and to limit the angle of drag in flight. The module 3 a is in the form of a substantially cylindrical fuselage of circular base 30 a, making it possible to simplify its production line and its maintenance. Access doors 9 are incorporated into the fuselage.
[0041] Because the carriage module is not designed to obey only flight control constraints, these being dedicated to the propulsion module, there is even more freedom in the form it can adopt. However, this carriage module is self-contained in terms of energy supply as it houses an auxiliary power unit (APU). An APU in fact supplies the energy necessary for starting the engines, for the air conditioning and for pressurizing the module.
[0042] The form of the carriage module can be adapted homothetically to suit the type of goods and/or the type of flight, for example from a transversely widened form like that illustrated in FIG. 1 b. This module in particular has an external fuselage of oblong shape of ovoid type 30 b, of a length suited to the type of goods and to the type of flight—long-haul or medium-haul—this ovoid shape of the fuselage allowing more or less the same center of gravity to be defined while at the same time varying the capacity to carry goods or passengers.
[0043] FIGS. 2 a and 2 b respectively show the passenger-carriage module 3 a and goods-carriage module 3 b. More specifically, the coupling faces 32 and 33 for coupling with the propulsion module are visible in these figures. These faces are planar and orthogonal. The face 32 is radial and extends perpendicular to the main axis X′X. The longitudinal other face 33 extends parallel to the axis X′X as far as, on the one hand, an edge 100 in common with the radial face 32 and, on the other hand, a radial cutout 101 of an upper cylindrical section 102 .
[0044] Spigots 50 and 51 are respectively incorporated into the radial face 32 and longitudinal face 33 in order to perform the mechanical couplings with the propulsion module, as will be described in greater detail hereinafter. As an alternative, these spigots may be incorporated into the corresponding coupling faces of the propulsion module. These spigots are situated substantially in the central plane of symmetry Ps of the modules 3 a and 3 b and are off-centered respectively toward the edge 100 and toward the cutout 101 in order to maximize the push-together fit of the modules and the relative immobilization thereof once coupled. Effective and safe locking of the “fail safe” type (see below) is thus obtained.
[0045] The mechanical couplings to be achieved between a carriage module 3 a and a propulsion module 2 are now described with reference to the side view of FIG. 3 which illustrates these modules aligned along the axis X′X so that they can be coupled. The modules have, facing one another, tubular end parts 31 a and 21 of the same outline, so as to ensure complementary shape continuity, after coupling, with the same external form.
[0046] The carriage module 3 a comprises, arranged under the generally cylindrical fuselage 30 a of this module: cameras 70 which assist with running, a retractable front landing gear 34 , coupling spigots 50 and 51 and an additional spigot 55 for coupling to a vehicle 5 that tows it along the ground.
[0047] In one embodiment, the view in cross section of FIG. 3 a illustrates the spigot for attachment of the carriage module 3 a to a towing vehicle 5 . This additional spigot 55 enters a housing 62 of the vehicle 5 via a bushing 52 mounted on a bearing 53 .
[0048] Prior to coupling to the propulsion module, the passengers and luggage and/or the goods are loaded as a parallel operation then, as soon as the carriage module 3 a is ready to depart, it can already be pressurized, making it possible to even out the cabin pressurizing/depressurizing curves, for better passenger comfort.
[0049] In addition to the equipment already described with reference to FIGS. 1 a and 1 b, the propulsion module 2 comprises, with reference to FIG. 3 , the orthogonal coupling faces—the radial face 22 (to be coupled to the face 32 ) and the longitudinal face 23 (to be coupled to the face 33 )—a retractable landing gear 24 , a stabilizing stand leg 25 —to facilitate coupling/uncoupling phases and to stabilize the module while it is being filled with fuel—and retractable locking shutters 60 and 61 (shown as hidden detail through the wing structure 4 a ). These locking means are mounted in housings 62 , 63 which receive the spigots 50 and 51 of the carriage module 3 a. In the phase in which the propulsion module 2 approaches and runs along the axis of the carriage module 3 a, the pilots are assisted by cameras 71 , 72 installed on the central portion 41 of the upper wing structure 4 a of the module: there is no longer a direct view of the runway because the spar 42 and the upper wing structure 41 do not allow a complete view but instead allow an appreciation to be gained via viewing means capable of supplying additional data, for example regarding the condition of the runway.
[0050] The coupling (arrows Fc) of the two modules by bringing them axially closer together along the axis X′X is automated by laser with load transfer compensation—in the same way as known guidance systems of “Belouga” type—in order to avoid any risk of damage. The spigots 50 and 51 simultaneously and respectively marry with the housings 62 and 63 . When the flanges 40 c and 41 c of the spigots 50 and 51 have penetrated sufficiently far into the housings 62 and 63 , the blocking shutters 60 , 61 are actuated under pressure to block the spigots and lock them in these housings. The axial housing 50 of the radial face 32 is a cylindrical recess 62 . The housing of the radial spigot 51 of the longitudinal face 33 is a longitudinal slot 63 made in the central portion 41 .
[0051] The coupling between the modules has built-in safety (or is what is known as “fail safe”), guaranteeing an equivalent of two points of connection to each coupling point thanks to their positioning in interfaces 22 / 32 and 23 / 33 which are orthogonal. This coupling makes it possible to prevent any risk of the modules becoming detached.
[0052] The center-of-gravity computer mentioned earlier is also used for balancing according to the type of carriage module connected to the propulsion module, and in flight to balance the aircraft to make it stable and flyable, in conjunction with the flight controls.
[0053] When the propulsion 2 and carriage 3 a or 3 b modules are being separated following landing, the propulsion module goes to the end of the runway and the pressure on the shutters is removed: the spigots 50 and 51 are released by the withdrawal of the shutters 60 and 61 freed of their pressurizing. A drive vehicle comes to collect the carriage module to bring the passengers or goods to the terminal provided for disembarkation. The carriage module remains self-contained in terms of energy by starting its APU. During the transfer time, a new module, which has already been filled, is coupled to the propulsion module so that the aircraft thus reconstructed can run out to the end of the runway and take off immediately.
[0054] The view in cross section in FIG. 3 b shows one example of the mounting of the spigot 50 on the rear coupling face 32 of the carriage module 3 a. The spigot 50 is mounted on a domed sealed end 15 held by a structural stiffening web 16 . The domed end 15 is fixed at the end of the fuselage skin 30 a by orbital rivets 17 . A fairing 18 extends the fuselage skin to form the coupling face 32 .
[0055] With reference to the front half view of the propulsion module 2 illustrated in FIG. 4 , it is apparent that the upper wing 40 a and the lower wing 40 b of the wing structures are far enough apart that the upper wing 40 a does not disturb the engine 5 a. This figure also partially shows the coupling face 22 for coupling with the radial face 32 of the carriage module 3 a (see FIG. 2 a ), the flight deck 6 and the tail unit 7 .
[0056] When the two, propulsion 2 and carriage 3 a, modules are coupled by the blocking of the spigots 50 and 51 in the appropriate housings 62 and 63 by the shutters 60 and 61 ( FIG. 3 ), the modular aircraft 1 is as illustrated in the side and top views of FIGS. 5 a and 5 b . The carriage module 3 a in this instance is a module of the “ferry flight module” type created using a very short fuselage in the overall shape of an ogive and dimensioned to ballast the aircraft and give it an aerodynamic shape. The external forms of the modules 2 and 3 a are in continuous continuation once the modules have been coupled which means that the aircraft la appears to be made up as a single piece. Advantageously, the forms may be slightly conical in order to improve their centering and flush fitting and the aerodynamic connection between them.
[0057] The invention is not restricted to the embodiments described and depicted. Thus, there may be multiple spigots on each coupling face, these for example being organized in a line, a circle or an array. These spigots may be mounted on the coupling faces of the carriage module or of the propulsion module. Further, the pressure means applying pressure to the spigots may be actuating cylinders, springs or elastic leaves. | According to one embodiment, a modular aircraft includes a propulsion module dedicated to flight, combining avionic equipment—wing structures assembly, flight deck, engines, tail unit—and a module dedicated to the carriage of passengers and/or goods. These modules include external cells extending longitudinally along a main axis and having tubular end parts of the same outline in the region of two disconnectable-coupling structures, one axial-coupling structure for keeping an end face of the propulsion module against an end face of the carriage module, and one radial-coupling structure for keeping an end face of the propulsion module against an end face of the carriage module. The wing structures assembly of the propulsion module includes two wing structures having opposite sweeps which are connected at the end and by a longitudinal connecting spar. | 1 |
Field Of Invention
[0001] The present invention relates to step ladders and more particularly pertains to an improvement to an A-frame ladder allowing it to be placed on uneven surfaces.
BACKGROUND
[0002] Stepladders are free-standing ladders that can be erected without support from a wall, and can be folded together under transport. A stepladder consists of a step frame, which is pivotally attached to a smaller support frame. The step frame includes a number of rungs, or steps. Steps are climbing supports with “walking and/or stepping surfaces” typically ranging anywhere from 8 cm deep to 2-5 cm. The upper step is often a step-plate or platform, enabling a user to stand and move safely and comfortable. The step and support frames are connected by some locking mechanism that prevents the stepladder from collapsing.
SUMMARY OF THE INVENTION
[0003] The present invention overcomes a limitation of the prior designs, specifically by providing an easy to use mechanism wherein the stepladder is self-leveling. Whilst similar to conventional stepladders in some respects, the instant invention is able to accommodate uneven ground by virtue of a unique hinge apparatus.
[0004] A conventional fold out type stepladder only works well on a flat surface and is very unstable on anything else. In such instances, all of the legs of the ladder fail to touch the surface. In such instances, the conventional stepladder is not stable and not easy to stand upon, when set on uneven ground. For example, a fruit picker's ladder solves part of the problem by only having three legs; two in a step frame and a single leg at the back. They work well when pushed between the branches and foliage of a tree, but are mostly unstable when free standing.
[0005] Many inventions have tried to address this problem but they are inadequate at best; most being of the extendable leg type. They are awkward and time consuming to set up, particularly when the ladder has to be moved to many locations as in fruit picking. In accordance with aspects of the present disclosure, the instant self leveling stepladder with a universal hinge joint provides many new advantages that traditional a-frame step ladders are not capable to deliver.
[0006] In the description herein, some details are provided, such as examples of components and/or methods, to provide a thorough understanding of embodiments of the present invention. One skilled in the relevant art will recognize, however, that an embodiment of the invention can be practiced without one or more of the specific details, or with other apparatus, systems, assemblies, methods, components, materials, parts, and/or the like. In other instances, well-known structures, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Embodiments of the present disclosure are described herein with reference to the drawings, in which:
[0008] FIG. 1 is a side front perspective drawing image of the self-leveling step ladder self-leveling on uneven ground, in accordance with an embodiment of the instant invention;
[0009] FIG. 2 is a side rear perspective drawing image of the self-leveling step ladder self-leveling on uneven ground, in accordance with an embodiment of the instant invention;
[0010] FIG. 3 is a front perspective drawing image of the self-leveling step ladder self-leveling on uneven ground, in accordance with an embodiment of the instant invention;
[0011] FIG. 4 is an exploded top perspective image of the hinge comprised of a rubber tendon joint as the universal hinge, in accordance with one embodiment of the instant invention;
[0012] FIG. 5 is an exploded top perspective image of the hinge comprised of a ball and socket joint as the universal hinge, in accordance with another embodiment of the instant invention;
[0013] FIG. 6 is an exploded top perspective image of the hinge comprised of a mechanical joint as the universal hinge, in accordance with another embodiment of the instant invention;
[0014] FIG. 7 is an exploded top perspective image of the hinge comprised of a set of interlocking eye joints serving as the universal hinge, in accordance with another embodiment of the instant invention; and
[0015] FIGS. 8A and 8B are side and top views of the hinge comprised of a rope threaded ball joint as the universal hinge, in accordance with another embodiment of the instant invention.
[0016] FIG. 9 is an alternate embodiment illustrating a Y-shaped frame side, in accordance with another embodiment of the invention.
[0017] The novel features which are characteristic of the invention, as to organization and method of use, together with further objects and advantages thereof, may be better understood from the following brief disclosure considered in connection with the accompanying drawings in which one or more preferred embodiments of the invention are illustrated by way of example. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention.
DETAILED DESCRIPTION
[0018] The novelty of this invention revolves around the movement allowed by an unconventional hinge. Its unique design can be applied to almost any type of fold out step ladder. By virtue of the hinge, the two sides of a fold-out step ladder are allowed full movement in all planes. The two sides can open conventionally and also swing from side to side and at angles to each other. Their movement allows all four legs of the ladder to find contact with uneven ground and provide a stable platform to climb up on.
[0019] The universal hinge may be many possible versions, as illustrated in FIGS. 4-8 . For example, the universal joint may comprise an embodiments as simple as two linked eyes ( FIG. 7 ), one on each step frame, a piece of rope or cable passing through each frame. Or, alternatively, in another embodiment, a more complex version such as a knuckle style joint ( FIG. 5 ), similar to that used in automobile suspension. Whatever way, free movement to both frames will allow for all four legs to be stable on uneven ground.
[0020] Although this is a novel universal joint, there is nothing highly technological about the hinge. It could be merely two eye bolts linked together or two U-bolts; one attached to either frame. It could be as simple as a cable or tendon ( FIG. 6 ) from one side to the other. This design allows the ladder to open conventionally and also allows the frames to move from side to side independent of each other. It is this free movement in all planes that allows for all four legs to contact the uneven ground at the same time. The ladder very easily and quickly finds a stable position for safe climbing.
[0021] The applications and usage are many for the instant invention, ranging from a two or three step utility ladder, to high reaching ladders suitable for fruit picking. The invention will suit any application using a four-legged adjustable ladder on uneven ground. This style of four legged fruit picker ladder is much more stable than the three legged version. All versions allow movement in three planes to allow four-leg contact and engagement with uneven ground. It is to be appreciated that one or more of the elements depicted in the drawings/figures can also be implemented in a more separated or integrated manner, or even removed or rendered as inoperable in certain cases, as is useful in accordance with a particular application. Thus, while the present invention has been described herein with reference to particular embodiments thereof, a latitude of modification, various changes and substitutions are intended in the foregoing disclosures, and it will be appreciated that in some instances some features of embodiments of the invention will be employed without a corresponding use of other features without departing from the scope and spirit of the invention as set forth.
[0022] For example, the ladder having a wider base going up to a more triangular point—picker style—could be made of aluminum and fiberglass sides and round ladder rungs. Various sizes will accommodate all sorts of picking from straddling berries to picking coffee, for example, on mountain sides and all kinds or other fruits up to 16 feet or more. In other examples, configuring the instant invention as a low level two or three step ladder—non wobbly—for garden use, clipping and pruning.
[0023] Therefore, many modifications may be made to adapt a particular situation or material to the essential scope and spirit of the present invention. It is intended that the invention not be limited to the particular terms used and/or to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include any and all embodiments and equivalents falling within the scope of the instant disclosure.
[0024] The foregoing description of illustrated embodiments of the present invention, including what is described herein, is not intended to be exhaustive or to limit the invention to the precise forms disclosed herein. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the present invention, as those skilled in the relevant art will recognize and appreciate. As indicated, these modifications may be made to the present invention in light of the foregoing description of illustrated embodiments of the present invention and are to be included within the spirit and scope of the present invention. | A self leveling stepladder with a universal hinge joint providing many new advantages that traditional a-frame step ladders are not capable to deliver. | 4 |
FIELD OF THE INVENTION
The present invention relates to plankton removal from fish pens, more particularly to an improved system for displacing plankton from fish pens.
BACKGROUND OF THE PRESENT INVENTION
Fish rearing in pen, for example, in open net pens that usually but not exclusively are enclosed by open mesh, are exposed to the conditions prevailing in the water surrounding the pen.
Several undesirable conditions can occur in this water including, but not limited to:
1. Presence of toxic or parasitic plankton (usually algae or sealice).
2. Undesirable water temperature (usually too high).
3. Undesirable oxygen concentrations in the water (usually too low).
In natural bodies of water stratification of the water column can occur. This can lead to a condition where an undesirable condition is present in the upper part of the column but not below a certain depth. Examples of this condition include algal blooms where the significant portion of the bloom is in the euphotic or illuminated part of the column and thermal stratification wherein warmer water overlies colder water with a distinct thermocline between them. Often these phenomena are associated and sometimes linked.
Operators in some areas often use multiple air-lift pumps to provide algae-free water during algal blooms. These pumps are small, so many are required and do not discharge in a radial fashion. In addition, the flow rate achievable is low so that they often fail to provide adequate mitigation. Typically, these pumps would be arranged around the perimeter of a tarped net-pen system discharging in over the tarp.
Applicant is aware of one operator in Chile who has tried a simple vertical pipe with a pump inside it and discharges from the pipe in a substantially vertical direction. The reports have had reports that this strategy was not very successful. We have no data on flow rates so and therefore cannot estimate current or downfield dispersion.
One example of aeration and/or circulating devices is shown in U.S. Pat. No. 5,564,828 issued Oct. 15, 1996 to Haegeman which shows a system that takes water from in the pen moves it vertically and then disperses it with a tangential component to disperse and mix the water in the tank or pen. U.S. Pat. No. 4,350,648 issued Sep. 21, 1982 to Watkins and U.S. Pat. No. 5,110,510 issued May 5, 1992 to Norcross each describe recirculation systems wherein the output is diverted radially and adjustment are provided to control the output and how the water is recirculated, i.e. in Watkins a diffuser cone is connected to a diffuser hood that move together between a mixing position wherein the cone blocks the flow of water through float on which the system is mounted and an aerating position wherein the diffuser hood is positioned against the float and the cone is spaced above the float to divert the water.
U.S. Pat. No. 4,798,168 issued Jan. 17, 1989 to Vadseth et al. describes a system wherein water is pumped (air lifted) from below and injected tangentially into a peripherally closed tank to expel water in the tank through an overflow outlet. This patent does refer to drawing water at a suitable temperature form below, but they are discussing operation in cold temperatures where the water below is at a higher temperature than the water in the tank and they use the higher temperature water from below to raise the temperature in the tank.
BRIEF DESCRIPTION OF THE INVENTION
It is the main object of the invention to provide a system (method) for removing plankton from a fish pen.
Broadly the present invention relates to a method of removing plankton from a fish pen comprising pumping a cleaning water from a depth sufficiently low to provide a source of cleaning water having a density significantly higher than the water density of water in said pen, said pumping delivering higher density cleaning water at a velocity sufficient to distribute said higher density water across at least a major portion of the area of said pen while permitting at least a portion of said higher density water to sink toward a bottom of said pen at a rate to,carry plankton with it and dispensing said plankton carried to said bottom by said cleaning water from said pen.
Preferably said pumping dispenses said cleaning water substantially radially of an outlet without formation of an abrupt downward plume of water at said outlet.
Preferably said pumping dispenses said cleaning water substantially radially of an outlet to form a surface plume that extends over a major portion of the area of the surface of said pen. Preferably said pumping dispenses said cleaning water at a velocity having a component radially of said outlet of between 1 and 3 meters/second.
Preferably said pumping dispenses said cleaning water at a flow rate of between 1 and 2 cubic meters/second.
Preferably said cleaning water in said pen has a downward velocity obtained substantially solely based on turbulence and the difference in density between said cleaning water and said water in said pen.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features, objects and advantageous will be evident from the following detailed description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings in which
FIG. 1 is a schematic side elevation showing a pumping arrangement for practicing the present invention.
FIG. 1A is a section through the top end of the pipe showing the adjustment sleeve fixed in maximum open position.
FIG. 2 is a plan view of a layout using a single pumping system to service a plurality of side-by-side pens.
FIG. 3 is a schematic side elevation showing curved velocity vectors showing that the cleaning water has a velocity with a radial component and a downward component.
FIG. 4 is a cross section through a pen of a computer simulation showing velocity vectors (direction only) around a pumping system positioned in the center of the pen.
FIG. 5 is a plan view illustrating the layout used to actually measure water velocity at different distances from the pumping system and at different depths
DETAILED DESCRIPTION OF THE INVENTION
The plankton generally is not killed by a lowering of water temperature and thus, the plankton problem may only be cured by displacing it from the pen. Generally the goal may be expressed in terms of reducing the plankton density as expressed in cells per cubic milliliter (ml). A typical bad bloom might be as high as 10 to the 7 cells/ml. It is difficult to establish a number that is an “acceptable” level as it varies with both fish species and plankton species. With the present invention applied to a pen formed by an enclosed bag with a bottom outlet Applicant has achieved levels of 300-400 cells/ml when the outside was at a level of about 10 7 cells/ml. This was with very toxic algae and sensitive fish (Atlantic salmon), but with the stated results it was unnecessary to take the fish off feed. Effective mitigation might only be achieved with as little as a tenfold reduction. Success has been reported with as little as a 60% reduction.
FIG. 1 shows a side elevation of a pumping and dispensing system suitable for the present invention 10 . The system 10 illustrated is supported a suitable ring type float 12 that supports a motor such as a hydraulic motor 14 there above on a structure schematically represented at 16 that is connected to and extends above the float 12 . The structure 16 also extends below the float 12 and supports an open cage 18 formed by circumferentially spaced rods 20 ( 4 shown in FIG. 1) that are connected to the upper end of pipe 22 . The length D from the level L of the water to the intake end 22 A of the pipe 22 which preferably will be in the form of a bell mouth (not shown) tapering to the diameter of the pipe 22 is selected as will be described below to be sufficiently long to receive water from a suitable source.
A drive shaft 24 extends vertically form the motor 14 down through the float 12 , structure 16 and cage 18 into and for a distance down the pipe 22 and is connected to and drives a suitable pump impellor schematically indicated at 26 (See U.S. Pat. No. 5,681,146 issued Oct. 28, 1997 to White the teachings of which are incorporated herein by reference for the preferred impellor for use with the invention)
The shaft 24 also passes through and is concentric with an inverted conical deflector 27 that deflects the flow from the top of the pipe from flowing vertically to flowing substantially horizontally and radially out of the cage 18 as schematically represented the arrows 28 , Preferably the cone is oriented to direct the flow into the pen to be substantially horizontal across the pen. The sharp edge at the outlet 21 of the pipe 22 around which the flow adjacent to the periphery of the pipe 22 must flow generates turbulence in the water leaving the pipe 22 and this turbulence and the difference in density between the incoming water and the water in the pen produce a downward component of velocity to the incoming water leaving the pipe 22 which will normally be the sole source of the downward component.
The float 12 supports the pipe 22 cage 18 and cone 27 so that the depth d of the top of the cone 27 from the surface L of the water in the pen is generally less than about 500 mm and preferably d will be between 300 and 400 mm.
The pumping system 10 may be positioned in the centre of a single pen (as schematically represented in FIG. 4 but more likely a single pumping system 10 will be used to services a plurality of side by side pens such as illustrated in FIGS. 2 and 3. As shown in plan in FIG. 2 a double row of 4 pens each formed with sides 32 and bottoms 34 (see FIG. 3) of netting as represented by the dotted lines. A pair of pumping systems strategically placed in the corners of pens 30 symmetrically positioned on opposite sides of the axial and transverse centre lines of the plurality of pens each directing flow radial in all directions from its outlet as indicated by the arrows 36 i.e. same as the flow represented by the arrows 28 in FIG. 1, however the arrows 36 are also shown in FIG. 3 to show the downward component of the flow of the cleaning water (characteristics of which will be described below) to sweep the plankton from the pens i.e. primarily through the bottoms 34 , but some may also flow through the sides 32 of the pens 30 . The corners of the two pens in which the pumping systems 10 have been positioned are bevelled off as indicted by the bevelled sidewalls 32 A in FIG. 2 . Obviously if the pumping system were located inside of a pen for example in the centre of a pen the bottom would be provided with a suitable aperture 9 not shown) to accommodate the pipe 22 .
In FIGS. 2 and 3 the service barge for the pens 30 and to which the pens 30 are moored is indicated at 38 and the depth of the bottom of the pens 30 by the height H and the length of the end 22 A of the pipe 22 by the distance D.
The sink rate of the cleaning water discharging from the pumping system 10 is substantially solely dependent on the differential density. It is thus an important feature of the invention to ensure that the radial discharge spreads the water out rapidly while preventing the formation of an abrupt downward plume. The term “abrupt downward plume” is intended to describe a plume that extends laterally from the outlet of pipe 22 i.e. from the cage 18 a short distance relative to the size of the pen for example less than 10% of the diameter of the pen and is the water is moving predominantly downward at this spacing from the outlet. The cone 26 directs the flow form the pipe 22 in a manner to obtain a surface plume that extends over a major portion of the area of the surface of the pen 30 that the flow from the pipe 22 is cleaning adjacent to the outlet of the pipe 22 , preferably at least 80% of the area of the pen that the flow from the pipe 22 .
The distance D is thus selected to provide access to a source of cleaning water having a density significantly higher than the water in the pens in which the plankton is growing so that the cleaning water leaving the pumping system 10 will have a component in the downward direction that is derived primarily form this difference in density, i.e. the downward component is induced primarily by gravity and the depth or distance D should threshold in a position to deliver higher quality water to the upper strata. Generally the toxic algal bloom does not usually extend significantly below the level of light penetration required for photosynthesis. Typically, in cold northern waters, this depth is on the order 10 meters, thus depth D will normally be greater than 10 meters.
Temperature is one factor that determines density but salinity must also considered as it contributes to density that controls the sink rate of the water. Typically, the water at depth D will have higher salinity and lower temperature than in the pen 30 .
It is preferred to obtain a discharge in the radial direction of between 1 and 3 meters/second (m/s). In one specific application of he invention the discharge was at about 2 m/s from the cage 18 . The flow from the system 10 will generally be 1 and 2 cubic meters per second (m 3 /s) and in the specific system referred to the flow was 1.5 m 3 /s.
The pumping system 10 should be able to adjust both the flow rate and the discharge velocity. The flow rate is adjusted by a changing the pump impellor 26 rpm and the discharge velocity is adjusted by a sliding sleeve 100 (see FIG. 1A) which is mounted in the pipe 22 by suitable bolts 102 that may be removed and the position of the sleeve changed by moving axially of the pipe to restrict the discharge area between the cone 26 and the top edge 21 of the pipe 22 i.e. the top edge of the sleeve becomes equivalent to the edge 21 . The sleeve 100 may be moved to provide a maximum outlet size as indicated at O max and a minimum outlet size as indicated at O min (see FIG. 1A) This permits adjustment for both different pen sizes and different density regimes.
Typical net-pens 30 are 10 meters deep i.e. distance H generally equals about 10 meters. Ideally, one would want the sink rate of the water to be equal to that depth H divided by the time it takes the water to move radially out from the pump 10 to the farthest edge 32 of the pen. Since it is difficult to know the sink rate in practice, the operator will adjust the discharge velocity until the desired lowering of cell count occurs at the side 32 . Assuming the velocity profile across the pen follows the distance square law one can estimate at transit time.
The best rule of thumb is to measure the plankton concentration and adjust accordingly. In practical terms one would set the flow rate to supply the desired amount of water to meet the fish's oxygen needs, as established by measuring oxygen (O 2 ) in the pens, and then adjust the velocity of discharge until the plankton levels were acceptable. In real world situations, given that this is an emergency device, it is believed the operator will likely pump as much water as possible and not bother with the details.
The purpose of this device is to provide water, which is superior in quality than that at the surface; to fish raised in a floating pen by lifting said water from a depth where it occurs and distributing it into the pen.
To prevent incursion of the undesirable surface water the pens may be enclosed with a tarp (commonly used to prevent such incursion) forming a barrier. This modifies the dispersion pattern by redirecting the outward flow downwards and may improve the effective dilution of the toxic algae.
As above indicated the pumping system 10 may also be positioned in the center of a pen 30 discharging outwards. A significant advantage of this approach is that the discharge is not required to traverse a net barrier in order to reach the fish. The drawback is that it would be more difficult to install during an emergency.
FIG. 4 is a computer-generated model of a system constructed according to the present invention showing eh velocity vector through one slice through a pen 30 with the pumping system 10 in the center profile
Velocities in the diagram of FIG. 4 range from a high of 2 m/s within the pump tube 22 to a low of few millimetres per second at the far pen wall 32 .
FIG. 5 shows the locations relative to the pumping system 10 where various water velocity measurements were made in a test to determine the effectiveness of the system. As shown the pumping system 10 was located adjacent to the periphery at one side of a circular pen 30 A and velocities were measured at circumferentially spaced locations 1 , 2 , 3 , and 4 on the periphery of the pen 30 A location with the same identifying number are spaced the same distance from eh pumping system 10 but are positioned on opposite sides of the pen. Table 1 presents the results of these tests using averages of the readings at each of the points.
TABLE 1
Depth d
Depth d
Depth d
Depth d
Depth d
Distance to
0 cm
30 cm
1 m
2 m
3 m
Pump 10
Velocity*
Velocity*
Velocity*
Velocity*
Velocity*
Location
meters(m)
m/second
m/second
m/second
m/second
m/second
1
4.5
0.41
0.27
0.04
0.04
0.04
2
8.2
0.29
0.21
0.03
0.02
0.03
3
10.7
0.24
0.14
0.05
0.03
0.02
4
11.5
0.2
0.12
0.04
0.03
0.02
• *Radial velocity - average of three readings
By averaging the readings from opposite sides pen 30 A compensated for the effect of the tidal currents at the site where the tests were conducted. These measured values confirmed that the computer model was accurate to the extent required.
Flow dispersion tests were also conducted using rhodamine dye to monitor flow patterns from the pump and to simulate a plankton effect. Observations were conducted during the tests by personal at the water surface, and by scuba divers at a depth of 10 meteres. Observations verified earlier velocity measurements and proved that flow penetration occurred to the desired depth of 10 meters. The movement of the dye simulates the expected movement of the plankton and confirmed that the plankton will be displaced from the pen when the present invention is applied
Having described the invention modifications will be evident to those skilled in the art without departing from the spirit of the invention as defined in the appended claims. | A method of mitigating plankton from fish pens moves denser cleaning water from a selected depth into the pen and discharges it to flow horizontally across the pen, but with a downward component and at a sufficient velocity so that the cleaning water sweeps (carries) the plankton from the pen. | 8 |
This is a continuation of U.S. application Ser. No. 08/516,744, filed Aug. 18, 1995, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to devices and methods for the transverse separation of material webs, particularly paper webs.
2. Description of Related Technology
The invention is concerned with a method as well as with a device for the transverse separation (i.e., cutting) of material webs. Such methods and devices are used, for example, in paper machines and, furthermore, in machines which are connected downstream of the paper machine, for example, in rewinders, coating machines, and reel cutters.
The known devices have a knife that is as wide as the machine and extends transversely with respect to the movement of the paper through the paper machine.
In the machines known in the art, the teeth of the knife cause "indentations" at the cutting edge of the web. These indentations are separated the same distance as the distance between the teeth of the knife.
During the separation process, it is advantageous to achieve a cut edge which is as shred-free as possible across the width of the material web.
Moreover, low indentation depth of the residual flap running into the coating machine is very important. If the paper indentations are too long and are partly cut or remain hanging, they cause doctor stripes or moist stripes in the case of LWC paper, for example, under the coating blade of the coating machine, and most of the time these stripes lead to tears.
Thus far, attempts have been made to shorten the indentations on the cutting edge of the material web: the tooth geometry of the knife has been varied and the rate at which the knife is introduced to the material web has been increased. Although the indentations can be made somewhat smaller, they cannot be avoided, especially at high web velocities. Indentations still represent a great problem.
SUMMARY OF THE INVENTION
It is an object of the invention to overcome one or more of the problems described above. It is also an object of the invention to reduce or completely avoid the indentations that occur at the cut edge of a material web during the separation of the web.
According to the invention a device and method for the separation of a running material web utilizes a toothed knife. The knife is swung into the material web at a very sharp angle of inclination with respect to the web. This angle of inclination is at most 45°.
Other objects and advantages of the invention will be apparent to those skilled in the art from the following detailed description taken in conjunction with the drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially schematic side view of a separating device according to the invention.
FIG. 2 is a partially schematic side view of a second embodiment of a separating device according to the invention.
FIG. 3 is an enlarged and partially schematic side view of the device of FIG. 2.
FIG. 4 is an enlarged view of a cut material web showing cutting indentations from a separating device according to the invention.
FIG. 5 is a side view of a separating device according to the prior art.
FIG. 6 is a side view of a second embodiment of a separating device according to the prior art.
FIG. 7 is a top view of a material web cut by a separating device according to FIGS. 5 or 6.
FIG. 8 is a top plan view of a knife according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
According to the invention, a separation device has a knife that is inclined extremely sharply against a material web with respect to a direction of movement of the web.
As a result of the extreme inclination of the knife to the material web, indentations on the cut edge of the separated web are greatly shortened and at best, disappear completely. The cut edge becomes a straight line. This result can be explained by the following four physical effects:
1. As a result of the extreme inclination of the knife, cutting time is shortened because to achieve complete separation of the paper web, it is not the height of the cutting teeth, but essentially the distance between the foot of the cutting teeth and the material web that must be reduced.
2. As a result of the extreme inclination of the knife, the indentations on the material web become shorter since the active cutting point migrates with the running web along the cutting tooth flank.
3. As a result of the extreme inclination of the knife, cutting time and indentation depth of the web are reduced, since, after the web is pierced by the first tooth tips, it attempts to "climb up" on the teeth of the knife. This leads to a slight movement of the web in the direction of the tooth feet, as a result of which the separation process is shortened. Thus, the web no longer has the tendency to avoid evade! the knife. As a result, the tendency of the web to form folds is avoided.
4. With a device according to the invention, the separation of the web is accomplished by cutting and not by tearing (as occurs with prior art separation devices). This is especially advantageous for the subsequent processing of the web.
In order to provide for easier handling of a machine-wide knife according to the invention, the device may include a knife having several separations at points along the width of the machine, resulting in several partial knife pieces. The partial pieces of the knife are lighter and shorter than traditional machine-wide knives and therefore are preferable for purposes of assembly or replacement.
A knife according to the invention is introduced to the material web via an activating element, which can operate, for example, pneumatically, hydraulically, electrically, piezoelectrically, magnetostrictively, magnetically or inductively. The force and the path (that is, the speed) of the knife can be adapted to meet desired requirements by using a suitable transmission (with a lever or another transmission). The movement of the knife can be in the form of a translation, a rotation or a combined movement thereof. A rotary inducing movement with the aid of a pneumatic cylinder with lever transmission is preferable.
A method and the device according to the invention make it possible to reduce the depth of the indentations on the web to zero in the ideal case. In such a case, the cut edge corresponds to a straight line along the entire width of the web which extends perpendicular to the direction of movement of the web.
As discussed herein, a decisive measure according to the invention consists in having an extremely sharp angle of inclination between the knife and the web. Accordingly, the angle should be less than 45° and the indentations of the knife should be oriented opposite to the direction of movement of the web.
Moreover, it has been found that there are two further parameters that have a certain influence on the indentation of the web: first, the speed of the material web and, second, the velocity with which the knife is placed into its working position. These three parameters: the angle between the material web and the knife, the velocity of the material web, and the velocity with which the knife is swung toward the web; can be adapted to one another in such a way that the cut edge of the material web will be approximately a straight line. Furthermore, it has been found the these three parameters are related to each other through the following equation:
tan α=V.sub.knife /V.sub.web
where:
α=the angle of inclination between knife and web;
V knife =the velocity of movement of the knife perpendicularly to the web; and
V web =the web velocity.
With respect to the drawings, FIGS. 1 and 2 each show a separating device according to the invention. FIG. 1 shows a "counterdirectional" cutting process. Here, the teeth of a knife 7 are directed against the web. In other words, the direction of movement of the knife 7 as it is swung (i.e. rotated) toward the web (see arrow d) is opposite or counter to a direction of movement w of a material web 5 being cut by the knife 7. Based on the kinematics of the device, at the moment of separation of the web 5, an immersion angle α (shown as angle 18 in FIG. 1) is formed between the knife 7 and the web 5. This angle is, for example, 20°. Even in the rest position, the knife 7 forms an angle 19 with the web 5, this angle being substantially smaller than 90°.
FIG. 2 shows a separation device according to the invention which is similar to the device shown in FIG. 1. However, this device carries out a swinging or rotational "codirectional" cutting process. Here, the knife 7 is not directed opposite to the web 5, but it is swung or rotated in a direction d' and thus generally moves in the same direction as the web 5 (moving in the direction w) during the cutting process.
Besides the knife 7, both the device shown in FIG. 1 and the device shown in FIG. 2 have means for swinging the knife 7, shown as an activating element 8 which engages with a double lever 9. Furthermore, the device includes means for adjusting the velocity of the knife 7 shown in the figures by the activating element 8. The knife 7 is secured at one of the free ends of the double lever 9.
FIGS. 3 and 4 show a mode of operation of an extremely inclined knife according to the invention. FIG. 3 shows the web 5 in a side view in a very schematic representation. The vector diagram in FIG. 3 shows a vector 15 of the relative velocity of the knife 7 with respect to the material web 5. It further shows a vector 16 of the relative velocity of the web to an optionally present velocity component of the knife. Vectorial addition of these two quantities gives a resultant vector 16a which forms an angle 21 with the vector 16. Under ideal conditions, the cut edge is adjusted so that the cutting angle 18 corresponds to the angle 21 between the vectors 16a and 16. In such a case, an ideal cutting line 14 is obtained as shown in FIG. 4. It can be seen from FIG. 4 how the partial sections of the individual tooth flanks 4 run together to a totally straight cutting line 14.
FIGS. 3 and 4 illustrate the ideal case of the cutting geometry. If, during penetration of the material web by a tooth tip 17, the material web "climbs onto" the tooth tip 17, then the movement processes are somewhat different. As previously noted, the speed of the material web, and the velocity with which the knife is placed into its working position influence the indentation of the web. The speed of the material web is controlled by means for adjusting the velocity of the material web that include one or more rolls 6, 6'.
FIGS. 5 and 6 show separating devices according to the state of the art. In the device according to FIG. 5, the knife 7 operates "counterdirectional" to the material web. The rest position of the knife forms an angle 11 of about 90° with the material web. Although during the cutting process this angle is smaller than 90°, it is by far not as small as an angle of inclination formed between a web and a device according to the invention.
In the device according to FIG. 6, an angle 11 is again about 90°. Due to the "codirectional" movements of the material web 5 and the knife 7, the immersion angle 13 of the knife 7 during the cutting process is greater than 90°.
The devices according to FIGS. 5 and 6 according to the state of the art provide an indented cut edge 3 as shown in FIG. 7. The indented cut edge 3 is very unfavorable for further processing.
FIG. 8 shows a knife 7 according to the invention. Indentations 2 of this knife are designed as in the known commercial knives. However, the fact that the knife 7 is made up of individual segments is new. The commissures 10 between the individual knives are placed expediently at the feet of the teeth, as shown in FIG. 8.
The following is an identification of the reference numbers used in the drawings:
1 Active cutting point
2 Tooth
3 Indented cut edge
4 Tooth flank
5 Material web
6 Roll
6' Roll
7 Knife
8 Activating element
9 Lever
10 Separation point
11 Angle: rest position of the knife in construction of the prior art
12 Angle: cutting angle of the prior art (counterdirectional)
13 Angle: cutting angle of the prior art (codirectional)
14 Cutting line
15 Velocity vector perpendicular to the web
16 Velocity vector parallel to the web
17 Tooth tip
18 Angle: adjusted cutting angle of the new construction
19 Angle: rest position of the new construction (counterdirectional)
20 Angle: rest position of the new construction (codirectional)
21 Angle: angle between vectors 15 and 16
The foregoing detailed description is given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as modifications within the scope of the invention will be apparent to those skilled in the art. | A device and method for separating a running material web includes a knife, having a substantially planar body and a toothed edge, and an apparatus for swinging the knife into the running material web. The method includes running the material web in a direction and subsequently swinging the knife toward the web in a direction, the cutting edge contacting the web at an angle of inclination between the knife body and the web measuring at most 45°. | 1 |
CROSS REFERENCE TO RELATED APPLICATION
This patent specification is based on U.S. provisional application 60/766,576, filed on Jan. 29, 2006 in the U.S. Patent and Trademark Office, the entire contents of which are incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This disclosure relates to a system, method, and computer program for providing brokerage services, and particularly for aggregated access to a plurality of brokerage services related to financial markets.
2. Discussion of the Background
Today investors are discovering that computers and, in particular, electronic trading of financial instruments over computer networks such as the Internet, have greatly empowered investors to self-manage and track their financial investment portfolios. Whether an individual investor is seeking to occasionally buy or sell stocks, bonds, or other financial instruments; a day trader conducting numerous such transactions each day; or a professional investor such as a licensed broker who manages the financial portfolios of numerous clients, access via a computer network to financial markets has become increasingly an important channel to conduct these transactions.
The ease of access to electronic trading has opened up great opportunities for novice investors to actively trade and maintain portfolios of their own without requiring participation in mutual funds or assistance from financial advisors or professional portfolio managers. This has resulted in the individual investor gaining hands-on experience with trading in financial instruments such as equities, and allowing them to transition to instruments such as bonds, foreign exchanges, and other instruments over global markets.
In order to have access to concurrent access to multiple markets it is necessary to access multiple brokerage services simultaneously. First, simultaneous brokerage access allows a user to monitor and take actions on multiple markets without delay. Second, this would create a natural competitive market among the participating brokers to offer competitive brokerage commissions. For example, an options specialized broker may offer the best brokerage rates for options contracts while another broker could offer the best margins over equity trades. Similarly a specialized foreign exchange (forex) commodities broker can be in a position to offer the better deal than a generic one.
Traditionally, concurrent trading in multiple markets and multiple instruments has been the domain of big institutional investors due to the resource heavy requirement of having dedicated fund managers for each channel of execution or type of financial instrument or market. However, complex trading strategies are difficult for an individual because usually each brokerage service requires a different access terminal client or user interface that each demands dedicated extra resources when managing a personal portfolio.
SUMMARY OF THE INVENTION
According to an aspect of the present invention, a brokerage aggregation system for receiving an electronic message having at least one activity request directed to one or more brokerage service firms and outputting the activity request includes an input interface configured to receive the electronic message in a first predetermined format, a plurality of output interfaces, each configured to connect to a corresponding brokerage service firm, and to transmit the at least one activity request in one of a plurality of second predetermined formats, wherein each of the plurality of second predetermined formats corresponds with a particular brokerage service firm, and a controller configured to receive and extract the at least one activity request from the electronic message, determine to which of the plurality of output interfaces the at least one activity request is to be transferred for subsequent transmission to a destination brokerage service firm, reformat the at least one activity request from the first predetermined format to the second predetermined format corresponding to the output interface previously determined, and transfer the at least one activity request after reformatting to the determined output interface for subsequent transmission to the destination brokerage service firm.
According to another aspect of the present invention, a brokerage aggregation method for receiving an electronic message having at least one activity request directed to one or more brokerage service firms and outputting the activity request includes receiving from an input interface the electronic message in a first predetermined format; extracting the at least one activity request from the electronic message; determining to which of a plurality of output interfaces the at least one activity request is to be transferred for subsequent transmission to a destination brokerage service firm; reformatting the at least one activity request from the first predetermined format to a second predetermined format corresponding to the output interface previously determined, the second predetermined format corresponding with a particular brokerage service firm; transferring the at least one activity request after reformatting, to the determined output interface; and transmitting the reformatted at least one activity request to the destination brokerage service firm.
Still according to another aspect of the present invention, a computer readable program including instructions for receiving an electronic message having at least one activity request directed to one or more brokerage service firms and outputting the activity request, the computer program being embedded in a computer readable medium, includes receiving from an input interface the electronic message in a first predetermined format; extracting the at least one activity request from the electronic message; determining to which of a plurality of output interfaces the at least one activity request is to be transferred for subsequent transmission to a destination brokerage service firm; reformatting the at least one activity request from the first predetermined format to a second predetermined format corresponding to the output interface previously determined, the second predetermined format corresponding with a particular brokerage service firm; transferring the at least one activity request after reformatting, to the determined output interface; and transmitting the reformatted at least one activity request to the destination brokerage service firm.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
FIG. 1 shows a conventional system for accessing multiple brokerage service firms;
FIG. 2 shows a brokerage aggregator according to one embodiment of the present invention;
FIG. 3 shows a method of operation of the brokerage aggregator;
FIG. 4 shows a routing table used by the brokerage aggregator according to an embodiment of the invention;
FIG. 5 shows a method of operation of a reformatting unit used by the brokerage aggregator according to an embodiment of the present invention; and
FIG. 6 shows one implementation of a computer processing unit used in the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
In the following description, various aspects of the present invention will be described. For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the present invention. However, it will also be apparent to one skilled in the art that the present invention may be practiced without the specific details. Furthermore, well known features may be omitted from or simplified in the specification in order not to obscure the present invention.
FIG. 1 shows a conventional system 100 used to access multiple brokerage services. In the example of FIG. 1 , a user 102 intends to make financial activity requests, such as buying or selling equities, on clearing exchanges 116 , 118 , and 120 . The clearing exchanges can represent one or more financial markets or financial exchange institutions, such as NASDAQ, The New York Stock Exchange, or any foreign exchange. Such clearing exchanges are widely known to the public and those skilled in the art.
The user has accounts with brokerage firms 110 , 112 , and 114 , each firm being able to execute transactions on a different clearing exchange. Such Brokerage firms include for example Ameritrade, E-trade, or Fidelity and other firms that are widely known to the public. The user wishes to maintain access to brokerage firms 110 , 112 , and 114 concurrently in order to efficiently complete transactions over multiple clearing exchanges. In order to accomplish this, the user must access three separate access clients 104 , 106 , and 108 simultaneously. FIG. 1 shows that each access client is running on a separate machine, with three separate connections to each brokerage firm, but the access client can also represent different interfaces that must be kept open simultaneously on the same machine. In either case, the user must switch between various user interfaces to complete each transaction, which consumes time and computer resources.
FIG. 2 shows one possible implementation of an embodiment of the claimed invention. A Brokerage Aggregation System 200 is shown having a controller 220 , an input interface 208 , and output interfaces 222 , 224 , and 226 .
In FIG. 2 , an access terminal client 204 connects to the input interface 208 . Access terminal client 204 is preferably a computer processing unit (CPU) operated by a user 202 . However it is not limited to a CPU. Access terminal client 204 may be replaced with other types of devices including, but not limited to, client terminals in communications with one or more servers, or with personal digital/data assistants (PDA), laptop computers, mobile computers, Internet appliances, two-way pagers, mobile phones, or other similar desktop, mobile or hand-held electronic devices. Other or equivalent devices can also be used to practice the invention.
The input interface 208 is preferably an Ethernet interface, however it may be any type of networking interface that is commonly known to those skilled in the art, including but not limited to a wireless interface or a serial interface. The link 206 between the access terminal client 204 and the input interface 208 is optionally achieved by an Ethernet cable connection. However, the link, and any other link or connection described in this specification, may be any type of connection achieved between two electronic devices on a network. Examples of such links are a serial communications link, a wireless connection, or any other type of connection commonly known to achieve network connectivity. Further, the communication link 206 is preferably over any IP access network, including but not limited to various derivatives of IP, TCP, UDP protocol carriers such as Internet, an intranet, a wireless access such as GPRS, a Virtual Private Network (VPN), and other types of communications networks.
The input interface 208 connects to the controller 220 . The controller 220 is shown as a sub-system within the Brokerage Aggregation System 200 . Controller 220 includes a determination unit 210 , communication bridging unit 218 , and reformatting units 212 , 214 , and 216 . Throughout this specification, the term “determination unit” may be interchanged with the term “routing unit” or “router” without changing its meaning. Also, the term “reformatting unit” may be interchanged with the term “gateway” or “gateway server” without changing its meaning.
The input interface 208 is connected to the determination unit 210 . The determination unit 210 is in one embodiment a CPU, but it may also be any computing device or router with the ability to receive, process, and transmit data according to a routing table. Such devices are commonly known to those skilled in the art.
The determination unit 210 is shown in FIG. 2 with three outputted connections 250 , 252 , and 254 , however there may be any number of outputs depending on the scale of the system. The determination unit also has a storage unit 211 for storing a routing table. The determination unit 210 further has an interface 260 that is connected to an information server 264 via a link 262 .
The outputs from determination unit 210 connect to reformatting units 212 , 214 , and 216 . FIG. 2 also shows a communication bridge 218 between the determination unit 210 and the reformatting units, however the determination unit can connect directly to the reformatting units or through any network such as a private network or the internet. There are three reformatting units 212 , 214 , and 216 shown in FIG. 2 , however there may be more depending on the scale of the system. Each reformatting unit may be implemented as a CPU, however it may be any equivalent device that can receive, process, and transmit data.
In an exemplary configuration, each determination unit is connected to a brokerage service firm, such as brokerage firms 234 , 236 , and 238 via the output interfaces 222 , 224 , and 226 . FIG. 2 shows separate physical interfaces used for the output interfaces 222 , 224 and 226 , however each output interface may instead be a virtual interface. An example of a virtual interface is where there is a single physical interface that supports one or more network addresses allowing external devices to view each network address as a separate virtual interface.
The links 228 , 230 , and 232 , that are located between each determination unit and each brokerage firm, can be any type of network connection as was discussed above.
FIG. 2 additionally shows clearing exchanges 240 , 242 , and 244 connected to the brokerage firms 234 , 236 , and 238 respectively. Each brokerage firm and clearing exchange shown in FIG. 2 may be similar to the brokerage firms and clearing exchanges discussed in reference to the conventional system in FIG. 1 .
Next, an operation of the aggregator system 200 will be described.
In the example embodiment of FIG. 2 , the client 204 has network connectivity with each brokerage firm 234 , 236 , and 238 . Preferably, this network connectivity can be achieved with normal methods of establishing IP connectivity through an IP network as is well known in the art. In this example, the user has already been authenticated to communicate with each of the brokerage firms upon establishing connectivity with the brokerage firms. Such authentication procedures are well known to those skilled in the art and will not be discussed in detail.
The user 202 interacts with the access terminal client 204 . The access terminal client 204 is shown having a graphical user interface (GUI) 205 . GUI 205 displays a variety of user options to the user. Through GUI 205 , the user can access multiple brokerage services associated with the brokerage firms 234 , 236 , and 238 to initiate activity requests. Activity requests can be any action requested by the user that pertains to a capability of the system. Examples of activity requests include, but are not limited to, an order request to buy or sell an electronically traded financial instrument, a modification request to modify an order to buy/sell a financial instrument, a request to view the portfolio for a given investor account, and a request to view recent trade history for a given investor account.
After the user makes a selection on a type of activity request, the access terminal client 204 generates an activity request to be sent to the controller 220 . The activity request itself contains information data pertaining to the type of specific transaction that the user inputted to the GUI 205 . The activity request is contained in an electronic message that is formatted for transmission to the controller 220 . It is noted that multiple activity requests may be contained in the message for situations where the user wishes to perform multiple activity requests simultaneously.
The access terminal client 204 formats the message containing the activity request into a common intermediate format (CIF) standard such as Financial Information eXchange (FIX). The FIX standard is exemplary, but any other open standard for formatting financial transactions may be used.
A method illustrating how the message from the user 202 is transmitted to the brokerage firms is shown in FIG. 3 . In step 302 , the input interface 208 receives the message over link 206 and delivers it to the determination unit 210 . The determination unit 210 stores an order routing table in the storage unit 211 . In step 304 , the determination unit 210 extracts the activity request from the message formatted in the common intermediate format (first predetermined format).
In FIG. 3 , step 306 , the determination unit 210 determines to which output interface to transfer the activity request(s). The activity request or order is matched against the entry in the order routing table for a valid pathway to the brokerage service firm. In this example, the order routing table optionally checks a user ID, a destination brokerage firm ID, and then checks to see the proper destination reformatting unit 212 , 214 , or 216 . If a valid entry exists, the same order still in the common intermediate format is forwarded further to the proper reformatting unit.
An exemplary order routing table 400 is illustrated in FIG. 4 . The activity request is checked to see which user and which broker have been specified. The “Gateway” column 408 indicates which gateway, or reformatting unit the request will be routed to. As an optional column, the type of market as listed in column 406 may be specified in the activity request as an indicator on where to route the message.
Additionally, a list of symbols to route to a specific brokerage firm may be in an optional column 410 (example “IBM.L” traded on FTSE is linked to “BROKER-2” for execution action in FTSE not NYSE that “BROKER-1” provides which is also associated with “USER-1”). The information illustrated in FIG. 4 is exemplary only. Other types of electronic information in other formats can also be used and the invention is not limited to the electronic information displayed in FIG. 4 .
In FIG. 3 , step 308 , the reformatting unit receives the activity request from the determination unit and reformats it from the CIF format to the brokerage firm format (second predetermined format) for the corresponding destination brokerage service firm. Each reformatting unit maintains a communication link with a specific brokerage service firm. The brokerage service firm may be a private institution that is designed to receive activity requests in a predetermined format or protocol. The protocol employed by each brokerage firm will be different from the CIF used by the terminal access client 204 , and in many cases the protocol used by the brokerage service firm will be proprietary to the brokerage service firm.
In FIG. 3 , step 310 , the reformatting unit transfers the reformatted activity request to a corresponding output interface, which is either 222 , 224 , or 226 in FIG. 2 . Then, in step 312 , the output interface transmits the reformatted activity request to the destination brokerage firm.
FIG. 5 shows an example activity request and the resulting translating action the gateway server performs. Here an activity request such as 508 for a buy order of 100 stocks of symbol IBM at market price is requested from access terminal client, and the request in common intermediate format (such as FIX). The activity request is transformed into the broker specific format using the database 502 based on table 504 . A sample structure of table 504 is shown in FIG. 5 and may contain an activity type (such as 514 ), a broker side proprietary format string (such as 512 ) and a system side common intermediate format (such as 510 ).
Although not shown in FIG. 5 , it should be understood that the similar reverse transformation from proprietary brokerage format to common intermediate format is also performed for resulting response in connection to the original user activity request. In FIG. 5 when the brokerage service 550 informs the relaying gateway 500 of the order's execution or resulting status in response to user's activity request, the response is translated back into the common intermediate format and is relayed back to the access terminal client for display to the user.
Thus, the above disclosed configuration allows the user to use a single graphical user interface to communicate with multiple brokerage service firms that use various different protocols.
FIG. 2 shows an additional interface 260 connected to the determination unit 210 . The interface 260 allows the determination unit to be connected to an information server 264 over communications link 262 . The information server 264 provides information data to the determination unit such as financial news, brokerage firm information, and financial market values. The information provided by information server 264 is preferably in quantifiable numerical form, such as stock quotes, or price information about brokerage firm rates. An example of such an information server is any web-based stock tracker such as Google Finance or Yahoo Finance.
The determination unit 210 can utilize the information received from the information server in multiple ways. The determination unit can update the routing table 400 with an indication of a stock that is available on a particular market. Additionally, the determination unit 210 can have a triggering mechanism in which the change in price of a stock can trigger a buy or sell order if the stock reaches a certain price. The stock price that triggers such an action can be pre-programmed into the determination unit 210 by the user. When the determination unit 210 triggers such a buy or sell order it then generates an activity request as if the user had sent it. The activity request is then forwarded to the proper reformatting unit based on the route indicated in the routing table, which then forwards the activity request to the designated brokerage firm.
FIG. 6 illustrates a computer system 601 upon which the access client terminal 204 , the determination unit 210 , and the reformatting units 212 , 214 , and 216 of FIG. 2 may be implemented. The computer system 601 includes a bus 602 or other communication mechanism for communicating information, and a processor 603 coupled with the bus 602 for processing the information. The computer system 601 also includes a main memory 604 , such as a random access memory (RAM) or other dynamic storage device (e.g., dynamic RAM (DRAM), static RAM (SRAM), and synchronous DRAM (SDRAM)), coupled to the bus 602 for storing information and instructions to be executed by processor 603 . In addition, the main memory 604 may be used for storing temporary variables or other intermediate information during the execution of instructions by the processor 603 . The computer system 601 further includes a read only memory (ROM) 605 or other static storage device (e.g., programmable ROM (PROM), erasable PROM (EPROM), and electrically erasable PROM (EEPROM)) coupled to the bus 602 for storing static information and instructions for the processor 603 .
The computer system 601 also includes a disk controller 606 coupled to the bus 602 to control one or more storage devices for storing information and instructions, such as a magnetic hard disk 607 , and a removable media drive 608 (e.g., floppy disk drive, read-only compact disc drive, read/write compact disc drive, compact disc jukebox, tape drive, and removable magneto-optical drive). The storage devices may be added to the computer system 601 using an appropriate device interface (e.g., small computer system interface (SCSI), integrated device electronics (IDE), enhanced-IDE (E-IDE), direct memory access (DMA), or ultra-DMA).
The computer system 601 may also include special purpose logic devices (e.g., application specific integrated circuits (ASICs)) or configurable logic devices (e.g., simple programmable logic devices (SPLDs), complex programmable logic devices (CPLDs), and field programmable gate arrays (FPGAs)).
The computer system 601 may also include a display controller 609 coupled to the bus 602 to control a display 610 , such as a cathode ray tube (CRT), for displaying information to a computer user. The computer system includes input devices, such as a keyboard 611 and a pointing device 612 , for interacting with a computer user and providing information to the processor 603 . The pointing device 612 , for example, may be a mouse, a trackball, or a pointing stick for communicating direction information and command selections to the processor 603 and for controlling cursor movement on the display 610 . In addition, a printer may provide printed listings of data stored and/or generated by the computer system 601 .
The computer system 601 performs a portion or all of the processing steps of the invention in response to the processor 603 executing one or more sequences of one or more instructions contained in a memory, such as the main memory 604 . Such instructions may be read into the main memory 604 from another computer readable medium, such as a hard disk 607 or a removable media drive 608 . One or more processors in a multi-processing arrangement may also be employed to execute the sequences of instructions contained in main memory 604 . In alternative embodiments, hard-wired circuitry may be used in place of or in combination with software instructions. Thus, embodiments are not limited to any specific combination of hardware circuitry and software.
As stated above, the computer system 601 includes at least one computer readable medium or memory for holding instructions programmed according to the teachings of the invention and for containing data structures, tables, records, or other data described herein. Examples of computer readable media are compact discs, hard disks, floppy disks, tape, magneto-optical disks, PROMs (EPROM, EEPROM, flash EPROM), DRAM, SRAM, SDRAM, or any other magnetic medium, compact discs (e.g., CD-ROM), or any other optical medium, punch cards, paper tape, or other physical medium with patterns of holes, a carrier wave (described below), or any other medium from which a computer can read.
Stored on any one or on a combination of computer readable media, the present invention includes software for controlling the computer system 601 , for driving a device or devices for implementing the invention, and for enabling the computer system 601 to interact with a human user (e.g., print production personnel). Such software may include, but is not limited to, device drivers, operating systems, development tools, and applications software. Such computer readable media further includes the computer program product of the present invention for performing all or a portion (if processing is distributed) of the processing performed in implementing the invention.
The computer code devices of the present invention may be any interpretable or executable code mechanism, including but not limited to scripts, interpretable programs, dynamic link libraries (DLLs), Java classes, and complete executable programs. Moreover, parts of the processing of the present invention may be distributed for better performance, reliability, and/or cost.
The term “computer readable medium” as used herein refers to any medium that participates in providing instructions to the processor 603 for execution. A computer readable medium may take many forms, including but not limited to, non-volatile media, volatile media, and transmission media. Non-volatile media includes, for example, optical, magnetic disks, and magneto-optical disks, such as the hard disk 607 or the removable media drive 608 . Volatile media includes dynamic memory, such as the main memory 604 . Transmission media includes coaxial cables, copper wire and fiber optics, including the wires that make up the bus 602 . Transmission media also may also take the form of acoustic or light waves, such as those generated during radio wave and infrared data communications.
Various forms of computer readable media may be involved in carrying out one or more sequences of one or more instructions to processor 603 for execution. For example, the instructions may initially be carried on a magnetic disk of a remote computer. The remote computer can load the instructions for implementing all or a portion of the present invention remotely into a dynamic memory and send the instructions over a telephone line using a modem. A modem local to the computer system 601 may receive the data on the telephone line and use an infrared transmitter to convert the data to an infrared signal. An infrared detector coupled to the bus 602 can receive the data carried in the infrared signal and place the data on the bus 602 . The bus 602 carries the data to the main memory 604 , from which the processor 603 retrieves and executes the instructions. The instructions received by the main memory 604 may optionally be stored on storage device 607 or 608 either before or after execution by processor 603 .
The computer system 601 also includes a communication interface 613 coupled to the bus 602 . The communication interface 613 provides a two-way data communication coupling to a network link 614 that is connected to, for example, a local area network (LAN) 615 , or to another communications network 616 such as the Internet. For example, the communication interface 613 may be a network interface card to attach to any packet switched LAN. As another example, the communication interface 613 may be an asymmetrical digital subscriber line (ADSL) card, an integrated services digital network (ISDN) card or a modem to provide a data communication connection to a corresponding type of communications line. Wireless links may also be implemented. In any such implementation, the communication interface 613 sends and receives electrical, electromagnetic or optical signals that carry digital data streams representing various types of information.
The network link 614 typically provides data communication through one or more networks to other data devices. For example, the network link 614 may provide a connection to another computer through a local network 615 (e.g., a LAN) or through equipment operated by a service provider, which provides communication services through a communications network 616 . The local network 614 and the communications network 616 use, for example, electrical, electromagnetic, or optical signals that carry digital data streams, and the associated physical layer (e.g., CAT 5 cable, coaxial cable, optical fiber, etc). The signals through the various networks and the signals on the network link 614 and through the communication interface 613 , which carry the digital data to and from the computer system 601 maybe implemented in baseband signals, or carrier wave based signals. The baseband signals convey the digital data as unmodulated electrical pulses that are descriptive of a stream of digital data bits, where the term “bits” is to be construed broadly to mean symbol, where each symbol conveys at least one or more information bits. The digital data may also be used to modulate a carrier wave, such as with amplitude, phase and/or frequency shift keyed signals that are propagated over a conductive media, or transmitted as electromagnetic waves through a propagation medium. Thus, the digital data may be sent as unmodulated baseband data through a “wired” communication channel and/or sent within a predetermined frequency band, different than baseband, by modulating a carrier wave. The computer system 601 can transmit and receive data, including program code, through the network(s) 615 and 616 , the network link 614 and the communication interface 613 . Moreover, the network link 614 may provide a connection through a LAN 615 to a mobile device 617 such as a personal digital assistant (PDA) laptop computer, or cellular telephone.
In view of the wide variety of embodiments to which the principles of the present invention can be applied, it should be understood that the illustrated embodiments are exemplary only, and should not be taken as limiting the scope of the present invention. For example, the steps of the flow diagrams may be taken in sequences other than those described, and more or fewer elements may be used in the block diagrams.
While various elements of the preferred embodiments have been described as being implemented in software, in other embodiments hardware or firmware implementations may alternatively be used, and vice-versa. | A brokerage aggregation system, method and computer program for receiving an electronic message having at least one activity request directed to one or more brokerage service firms and outputting the activity request. The system includes an input interface configured to receive the electronic message in a first predetermined format, a plurality of output interfaces, each configured to connect to a corresponding brokerage service firm, and to transmit the at least one activity request in one of a plurality of second predetermined formats, wherein each of the plurality of second predetermined formats corresponds with a particular brokerage service firm, and a controller configured to receive and extract the at least one activity request from the electronic message, determine to which of the plurality of output interfaces the at least one activity request is to be transferred for subsequent transmission to a destination brokerage service firm, reformat the at least one activity request from the first predetermined format to the second predetermined format corresponding to the output interface previously determined, and transfer the at least one activity request after reformatting to the determined output interface for subsequent transmission to the destination brokerage service firm. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is entitled to the benefit of Provisional Patent Application Ser. No. 60/186,572 filed Mar. 2, 2000.
[0002] This is a Continuation-in-part of Ser. No. 09/775,362, Feb. 1, 2001, now abandoned.
FIELD OF THE INVENTION
[0003] The present invention is directed to the cryogenic separation of air by distillation for the production of primarily gaseous nitrogen.
BACKGROUND ART
[0004] Nitrogen is among the most heavily produced and used chemicals. It finds application in the petroleum, glass, foods, electronics, pharmaceutical, and metals industries. Cryogenic separation of air is a principal means of producing nitrogen. Cryogenic air separation plants, chiefly for the production of gaseous nitrogen, exist in a number of configurations. These, in turn, group around single distillation column and double distillation column designs. There are many variations of these designs in each category. In most cases the objective is to produce nitrogen at the lowest energy consumption for any given delivery pressure; but aspects such as capital cost and particular features of convenience are equally important.
[0005] A simple single-column system has a relatively low nitrogen recovery, the balance of the air being discharged as an impure product containing a substantial amount of nitrogen. Means have been suggested in more complex designs for increasing the nitrogen recovery in such systems and reducing the amount of energy required per unit of product nitrogen. Two-column systems have inherently greater nitrogen recoveries than simple single-column systems. Nevertheless, simple two-column systems do not necessarily have lower unit energy requirements than improved single column systems. Well-designed systems of either configuration compete for lowest unit energy consumption. The elements of energy consumption, capital cost, and particular convenient features remain important considerations.
OBJECT OF THE INVENTION
[0006] An object of the invention is to provide a process for a two-column cryogenic distillation of air which achieves high nitrogen recovery, low unit energy consumption, and, though nitrogen is produced by each distillation column operating at different pressures, the product gaseous nitrogen is delivered at a single pressure, a desirable and convenient feature, while maintaining high nitrogen recovery and low unit energy consumption.
SUMMARY OF THE INVENTION
[0007] Double distillation column systems which are designed to produce principally nitrogen have the following requirements:
[0008] 1. The condenser condensing nitrogen overheads from the high pressure column must boil a stream which boils at a temperature lower than said nitrogen condensing temperature.
[0009] 2. A vapor stream resulting from the aforementioned boiled stream which enters the low pressure column for further separation must be at or above the operating pressure of the low pressure column.
[0010] 3. The pressure of the low pressure column must be high enough such that at least a portion of the nitrogen overheads from the low pressure column can be condensed in a condenser against a boiling stream which boils at a colder temperature than the condensing nitrogen overheads. This boiling stream can be the bottoms liquid product from the low pressure column which is reduced in pressure upon entry into the condenser.
[0011] It can be seen then that such a system described above becomes easier to effect as the pressure ratio of the pressure of the high pressure column to the pressure of the stream vaporizing in the condenser of the low pressure column becomes greater. This pressure ratio, when coupled with the quantity of nitrogen actually recovered, has a direct impact on the requisite energy to produce a nitrogen product at a given delivery pressure. A greater pressure ratio indicates a higher energy consumption for a given product delivery pressure than other processes which have lower corresponding pressure ratios. For energy reduction, improvements in this process strive to reduce this pressure ratio and the related pressure ratio of the pressure of the high pressure column to the pressure of the low pressure column.
[0012] Another feature desirable but not essential to such processes is the recovery of all or most of the nitrogen at the pressure of the high pressure column, where part of the reflux made in the low pressure column condenser is pressurized and returned as additional reflux to the high pressure column.
[0013] The current invention improves on this process by conducting the condensation of vapors at the pressure of the high pressure column, all of which may be the overhead vapor from the high pressure column, in at least two stages of coolant vaporization in series. The composition of the boiling stream becomes richer in oxygen as the extent of vaporization increases. At essentially a constant temperature of vaporization, the first stage of vaporization occurs at a higher pressure of the vaporizing stream and the second stage at a lower pressure of the vaporizing stream. The vapor from the first stage is both richer in nitrogen and higher in pressure than the vapor from the second stage, and constitutes a feed to the low pressure column. Therefore, the pressure of the low pressure column is maximized—a desirable effect for a given high pressure column pressure, and oxygen is preferentially rejected from the column system from the second stage condenser. Because the composition of the liquid bottoms from the low pressure column are related to the composition of the vapor feed to the bottom of the low pressure column, these bottoms are richer in nitrogen and vaporize at a colder temperature when transferred to the low pressure column condenser and reduced in pressure, which reduces the ratio of the pressure of the high pressure column to the pressure of the low pressure column. The low pressure column condenser coolant can operate just above atmospheric pressure; but in alternative designs may operate at higher pressure, retaining the energy-reduction benefits of the invention. The effects of reducing the pressure ratio of the operating pressures of the two distillation columns, and rejecting an oxygen-rich mixture from the second or last stage of the high pressure column condenser lead to lower compression energy and higher nitrogen recovery, which minimize unit energy expenditure for the nitrogen produced at a specified delivery pressure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 is a schematic representation of one embodiment of the invention.
[0015] [0015]FIG. 2 is a schematic of another embodiment of the invention which has the capability to generate more refrigeration and entails more capital cost than the embodiment of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Referring to FIG. 1, air is compressed and cooled and the water condensate removed before entering typically an adsorption unit for the removal of residual water vapor, carbon dioxide, and other amounts of trace contaminants. The air 101 then enters the main heat exchanger 11 , where it is cooled to a temperature near its dew point, while products of the subsequent distillation—pure nitrogen 108 and waste nitrogen 107 streams enter as cold vapors at the opposite end and are warmed, receiving heat from the air which is being cooled. In some cases a small part of the air 105 may be liquefied and may be removed separately from the balance of the air which remains in vapor state. A reheat stream 106 composed of a second waste nitrogen stream also enters the cold end of the main heat exchanger and is partially warmed, before being withdrawn as 110 for expansion in turboexpander 12 .
[0017] After the air leaves the main heat exchanger, it enters the bottom section of the high pressure column 13 . The high-pressure distillation column is composed of trays or packing to effect mass transfer between the rising vapor and the downflow of liquid. The vapor becomes richer in nitrogen as it rises. The residual oxygen content of the vapor at the top of the column can be below 1 part per billion or 0.5% or higher. Part of the nitrogen vapor is condensed in condensers 15 and 18 in indirect heat transfer with a coolant for return to the column as reflux streams 114 and 115 , i.e. the liquid column flow which scrubs the oxygen out of the rising vapor. The balance of the nitrogen vapor 129 is removed from the high pressure column for warming in heat exchangers 19 and 11 and delivery as product 103 at pressure or to be further compressed in a product compressor.
[0018] The liquid bottoms product 111 from the high pressure column is composed of oxygen, nitrogen, and argon, and is typically termed “rich liquid” or “crude oxygen”. The rich liquid enters subcooler 19 and is divided into the coolant stream 116 which is routed to the nitrogen condensers 15 and 18 and a feed stream 124 to the low pressure column 20 after further subcooling in subcooler 19 .
[0019] Rich liquid 116 is throttled across valve 14 to a pressure low enough to reduce its vaporization temperature below the condensing temperature of nitrogen and enters condenser 15 where it is partially vaporized, as nitrogen vapor is condensed to make reflux for the high pressure column. Rich liquid 116 is partially boiled in condenser 15 and liquid and vapor phases are separated in separator 16 . The residual liquid from condenser 15 has a higher oxygen content than the rich liquid feed to condenser 15 . In order to vaporize the balance of this residual rich liquid, its pressure and temperature must be lowered still by throttling valve 17 which passes the residual rich liquid to condenser 18 , where it is all or nearly all vaporized. Nitrogen vapor from the high pressure column is also condensed in condenser 18 and becomes part of the reflux to the high pressure column.
[0020] The vaporized rich liquid from separator 16 is fed to the bottom of the low pressure column 20 . This rich liquid vapor was vaporized at essentially the operating pressure of the low pressure column. The balance of the rich liquid which was passed to condenser 18 is vaporized, is partially warmed in subcooler 19 and main heat exchanger 11 and turboexpanded in 12 to produce refrigeration. The turboexpander exhaust gas 109 is warmed in subcooler 19 and main heat exchanger 11 and may be used elsewhere or vented to atmosphere. This is a stream of elevated oxygen content; and therefore, its disposition in this manner assists in the separation of the air to make the nitrogen product.
[0021] The low pressure column 20 is a mass transfer device, also constructed of trays or packing, and processing liquid and vapor streams, as described above. The part of the rich liquid stream 124 fed to an intermediate point in the low pressure column has part of its nitrogen content stripped out by the vapor rising from the bottom of the low pressure column. The resulting liquid reaching the bottom of the low pressure column 123 is transferred to the condenser for the low pressure column after being subcooled in subcooler 19 and reduced in pressure at valve 23 . This stream serves as the coolant for condensing the nitrogen overhead vapor from the low pressure column in condenser 24 . The vaporized coolant 127 is passed through subcoolers 19 and main heat exchanger 11 , which recover its refrigeration, and may be used for regeneration of the air purification adsorber, for instance.
[0022] All the nitrogen vapor 128 which is produced in the low pressure column is condensed. Part of the condensate is returned as reflux to the low pressure column; and the remainder 125 is pumped by pump 22 to the pressure of the high pressure column, passed through subcooler 19 , and injected into the high pressure column as additional reflux.
[0023] Another embodiment of the invention is shown in FIG. 2. In this embodiment three condensers are employed for condensing reflux liquids primarily for the high pressure column. The purpose of such an arrangement is to vaporize the last portion of the rich liquid coolant 116 utilizing air as the heating medium in condenser 31 . In so doing, since air at approximately the pressure of the high pressure column 33 condenses at a higher temperature than nitrogen at the pressure at the top of the high pressure column, the last portion of rich liquid 209 which vaporizes in condenser 33 can vaporize at a higher pressure by being heated against air than against nitrogen. A higher pressure stream 208 , composed of streams 206 from condenser 34 and 207 from condenser 31 , is available for turboexpansion and production of additional refrigeration, for instance, for achieving a greater production of liquid nitrogen product, if desired.
[0024] Liquid air 203 produced in condenser 31 is routed principally to the high pressure column 33 for assisting the distillation there. Depending on overall distillation requirements, some liquid air may be routed to low pressure column 20 .
[0025] In other respects the process embodiment in FIG. 2 is similar to that of FIG. 1. Still another embodiment of the invention (not shown) achieves elevation of the low pressure column pressure and the high pressure column pressure by means of elevation of the vaporization pressure of the low pressure column condenser coolant. In these cases said vaporized coolant may also be turboexpanded to produce refrigeration. Another advantage of such operation is that the delivery pressure of the nitrogen product from the high pressure column can be efficiently raised to meet a specified product delivery pressure, while maintaining low energy requirements inherent in the process invention.
EXAMPLE
[0026] A process for the recovery of substantially pure nitrogen at a rate of 2687 Nm3/hr at a pressure of 4.9 atma is conducted in accordance with FIG. 1. Nm3/hr refers to the flow rate of a substance measured as a gas at 0 C. and 1 atma. C. refers to temperature in degrees Celsius; atma refers to pressure in absolute atmospheres. K refers to temperature in degrees Kelvin.
[0027] A feed air flow of 4632 Nm3/hr was compressed to a pressure of 5.2 atma, aftercooled to about ambient temperature, its water condensate removed, and passed to an adsorption unit for removal of water and carbon dioxide, and possibly other contaminants. The purified air 101 was passed to main heat exchanger 11 where it was cooled to approximately its dew point, producing a small amount of liquid. Air 105 entered the bottom of high pressure column 13 at 98.6 K and 5.05 atma. The high pressure column is internally made up of structured packing for mass transfer.
[0028] Gaseous nitrogen at a 94.1 K and 5.0 atma exited from the top of the high pressure column, and a portion was forwarded to subcooler 19 where it was warmed to 95.4 K, and further warmed in main heat exchanger 11 to ambient temperature. Nitrogen product exited the plant at 4.9 atma with an oxygen content of 5 vpm (parts per million by volume). The product constituted a 58% recovery based on the total air delivered to the cold box.
[0029] The balance of the gaseous nitrogen which exited from the top of the high pressure column was condensed in condensers 15 and 18 and returned to the top of the high pressure column as reflux.
[0030] The bottoms liquid product 111 exited from the high pressure column and had an oxygen concentration of 40%. This stream was subcooled to 96 K in subcooler 19 and then divided. The first part 116 at a flow rate of 1830 Nm3/hr was throttled in valve 14 to 3.05 atma and was passed to condenser 15 . 1058 Nm3/hr was vaporized and sent to the bottom of the low pressure column as stream 122 . The remaining liquid was throttled via valve 17 to 2.1 atma before entering condenser 18 as coolant. This remaining liquid was not totally vaporized in order to limit the concentrations of non-volatile contaminants. Stream 119 had a composition of about 51.5% oxygen. Stream 119 was warmed to 95.4 K in subcooler 19 and further warmed in main heat exchanger 11 to 120 K and passed to turboexpander 12 for expansion to 1.04 atma and 101.7 K. The exhaust stream 109 then was passed to the main heat exchanger where it was warmed to about ambient temperature.
[0031] The second part of rich liquid stream 111 was further subcooled to 91.9 K and stream 124 was reduced in pressure by valve 21 and fed to the low pressure column 20 .
[0032] The bottoms liquid product 123 from the low pressure column was subcooled in 19 , throttled via valve 23 to 1.2 atma, and introduced as coolant of condenser 24 . The vaporized coolant 127 had a flow rate of 888 Nm3/hr and contained 49.7% oxygen. This stream was not totally vaporized in order to limit the concentration of non-volatile contaminants. The nitrogen vapor 128 flow rate to condenser 24 was 1013 Nm3/hr and was totally condensed and a portion was returned to the low pressure column as reflux. The remaining liquid nitrogen 125 at a flow rate of 482 Nm3/hr was first passed to pump 22 , which pumped the liquid to the pressure of the high pressure column. Stream 125 was then warmed in subcooler to 93.9 K and added to the reflux flow of the high pressure column.
[0033] It is possible to produce a small amount of liquid product by withdrawing to storage liquid nitrogen at 132 , for instance. It is also possible to add liquid nitrogen at, for instance, 132 , to assist in supplying the refrigeration needs of the plant.
[0034] It is also possible to recover more than 60% of the air as nitrogen at the same pressure of feed air by modification of the operating and plant design conditions, requiring somewhat larger heat transfer equipment.
[0035] While particular embodiments of this invention have been described, it will be understood, of course, that the invention is not limited thereto, since many obvious modifications can be made; and it is intended to include within this invention any such modifications as will fall within the scope of the invention as defined by the appended claims. | Nitrogen gas at a single pressure is produced from a two-column cryogenic distillation of air. The bottoms liquid product from the high pressure column is divided into portions, at least one of which does not enter the low pressure column as a feed stream. By these means, a portion of an oxygen-rich stream is removed from the distillation, further enhancing nitrogen recovery and achieving low specific energy consumption for nitrogen product. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to Spanish Patent Application No. P200703424, filed Dec. 24, 2007.
TECHNICAL FIELD
[0002] The present invention relates to barbecues, and more specifically to domestic barbecues fired by a fuel such as natural gas or propane gas.
BACKGROUND
[0003] Barbecues comprise at least one hot surface upon which food may be disposed so that it may be cooked. The prior art contains known barbecues that comprise a main inlet through which fuel may be introduced in order to heat the hot surface and thus cook the food disposed on it. The fuel used is mainly natural gas or propane gas. A burner is disposed beneath the hot surface and the fuel reaches it through a through-pipe that connects said burner to the main inlet, and the fuel is ignited in said burner (in the form of a flame) and causes the heating of the hot surface and, therefore, the heating of the food disposed on said hot surface.
[0004] In some barbecues, once the fuel has reached the burner a user has to act directly on said burner to ensure the fuel lights, by means of a lighter, for example, or a similar device.
[0005] U.S. Pat. No. 5,813,394 discloses a barbecue in which the flame of the burner is ignited automatically, without the need for a user to act on the burner directly by means of a lighter or a similar device. For this reason, said barbecue comprises electronic control means that act on an igniter that causes the fuel to ignite.
SUMMARY OF THE DISCLOSURE
[0006] It is an object of the invention to provide an alternative barbecue to known barbecues in the prior art.
[0007] A barbecue in one implementation comprises at least one cooking surface upon which food may be cooked, a burner disposed beneath the cooking surface to cause the heating of said surface, and a main inlet through which fuel may reach the burner to allow the heating of the cooking surface when said fuel lights in said burner. The barbecue also comprises first and second through-pipes that connect the main inlet to the burner and through which fuel may pass from said main inlet to said burner, a multi-position gas inlet control valve for allowing fuel to pass to the burner through the first through-pipe when it is in a first position or through the second through-pipe when it is in a second position, and a flow valve linked to the through-pipes and the burner, by means of which the user may regulate the amount of fuel that reaches said burner when the control valve is in the first or the second position.
[0008] The barbecue also includes electromechanical control means that is activated when the control valve is positioned to direct gas flow through the second through-pipe. The electromechanical control means designed to allow or prevent the passage of the fuel through said second through-pipe when the control valve is disposed in the second position. In one embodiment the barbecue 100 also includes a gas pilot linked to the burner to cause, by means of the control means, said gas pilot to light the fuel that reaches said burner, an auxiliary pipe that connects the main inlet to the gas pilot and through which the fuel may pass from said main inlet to said gas pilot when the control valve is disposed in the second position, and an electrical power supply for providing electrical power to the control means.
[0009] As a result, and thanks to the control valve and the presence of two through-pipes that connect the main inlet to the burner, the barbecue may operate in two different operating modes. In the first operating mode the user places the control valve in the first position and affirmatively acts to cause the burner to light by means of lighting means such as a lighter, a manually activated spark device affixed to the barbecue, or similar means. In the second operating mode the user places the control valve in the second position and the control means receives power from the power supply and acts to cause the burner to light automatically.
[0010] Thus, the user may select the second operating mode when he wants to operate the barbecue in a more comfortable way, for example, or the first operating mode when he desires or when, for example, it is not possible to supply electrical power to the control means and it is not possible, therefore, to operate in the second operating mode.
[0011] These and other advantages and characteristics of the invention will be made evident in the light of the drawings and the detailed description thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 schematically shows a barbecue in an embodiment of the present invention.
[0013] FIG. 2 is a front view of a control panel in an embodiment of the present invention.
DETAILED DESCRIPTION
[0014] FIG. 1 shows an embodiment of a barbecue 100 of the present invention, which comprises at least one cooking surface 1 upon which food may be disposed so that it may be cooked, at least one burner 2 disposed beneath the cooking surface 1 to cause the heating of said cooking surface 1 , and a main fuel inlet 3 through which a fuel may be provided to the burner 2 in order to heat the cooking surface 1 , said fuel lighting in said burner 2 . Preferably the fuel is natural gas or propane gas, a flame being caused in the burner 2 (the lighting of said burner 2 ) when said fuel is ignited to cause said flame to heat the cooking surface 1 . The barbecue 100 may be designed to connect the main inlet 3 directly to the general gas inlet of a house, for example, and/or may be designed to connect said main inlet 3 to a gas cylinder (not shown in the figures).
[0015] In order to guide the fuel from the main inlet 3 to the burner 2 the barbecue 100 has a first through-pipe 4 and a second through-pipe 5 that connect said main inlet 3 to said burner 2 , the fuel passing through one of said pipes 4 and 5 from said main inlet 3 to reach said burner 2 . Said through-pipes 4 and 5 may be completely independent or they may comprise a common part that corresponds to the end that reaches the burner 2 , as shown in FIG. 1 . The barbecue 100 also has a gas control valve 6 , preferably a conventional three-position valve although it may also be of another type to allow the fuel to pass from the main inlet 3 to the burner 2 through the first through-pipe 4 or through the second through-pipe 5 , or to prevent the fuel from passing through any of said through-pipes 4 and 5 . Thus, when the control valve 6 is in a first position M the fuel is allowed to pass to the burner 2 through the first through-pipe 4 , said fuel being allowed to pass to the burner 2 through the second through-pipe 5 when said control valve 6 is in a second position A, the fuel being prevented from passing through both through-pipes 4 and 5 at the same time. In a third position O, the fuel is prevented from passing through either of the two through-pipes 4 and 5 .
[0016] The barbecue 100 also has a flow valve 7 linked to the burner 2 and to both through-pipes 4 and 5 , with the result that when the control valve 6 is in the first position M or in the second position A, a user may regulate the amount of fuel that reaches the burner 2 through either of said through-pipes 4 and 5 by acting on said flow valve 7 . The flow valve 7 is preferably of the conventional rotary type, causing said valve to allow more or less fuel to pass through in accordance with the position of said flow valve 7 when it is operated on (in accordance with the rotation of a control knob 17 in relation to an inactive OFF position). Said flow valve 7 having an inactive OFF position, in which it prevents any fuel from passing to the burner 2 , thereby preventing the heating of the cooking surface 1 until the position of said flow valve 7 is modified.
[0017] Due to the two through-pipes 4 and 5 and the characteristics of the control valve 6 , the barbecue 100 is designed to operate in two different operating modes. To ensure that said barbecue 100 operates in a first operating mode, a user places the control valve 6 in the first position M, thereby allowing fuel to pass from the main inlet 3 to the burner 2 through the first through-pipe 4 , while for it to operate in a second operating mode, the user has to place said control valve 6 in the second position A, thereby allowing fuel to pass from said main inlet 3 to said burner 2 through the second through-pipe 5 .
[0018] When the first operating mode is selected the fuel is allowed to pass to the burner 2 through the first through-pipe 4 , and by acting on the flow valve 7 the user may also regulate the amount of fuel that reaches the burner 2 . In order to cause the fuel to ignite in said burner 2 (the lighting of the flame), the user has to act affirmatively on said burner 2 by means of a manual igniter such as a lighter, a manually actuated spark device affixed to the barbecue, or a similar device.
[0019] When the second operating mode is selected the fuel is allowed to pass to the burner 2 through the second through-pipe 5 , and by acting on the corresponding flow valve 7 , the user may also regulate the amount of fuel that reaches the burner 2 . In said second operating mode the user does not have to act on the burner 2 in order to light the fuel, and for this reason the barbecue 100 includes an automatic igniter 10 and a controller/electronic control means 11 that may include, for example, a microprocessor or a microcontroller, which causes the fuel of the burner 2 to light by means of the igniter 10 and which is electronically linked to the control valve 6 , said controller 11 being capable of determining the position of said control valve 6 . Preferably the igniter 10 comprises a spark generator and the controller 11 causes sparks to be generated when it detects that the control valve 6 moves to the second position A. The igniter 10 may also comprise a hot-igniter, with the result that said controller 11 sends, in this case, a current to the igniter 10 in order to heat it when it is detected that said control valve 6 passes to said second position A. Preferably, the barbecue 100 also includes a gas pilot 8 disposed beneath or adjacent to the burner 2 , an auxiliary pipe 9 that connects the main fuel inlet 3 to the gas pilot 8 and through which fuel may pass to said gas pilot 8 , an electric valve 12 disposed in the second pipe 5 and an auxiliary electric valve 13 disposed in the auxiliary pipe 9 . Said barbecue 100 may comprise a gas pilot 8 for each burner 2 or a gas pilot 8 common to all the burners when it has more than one burner. When the user selects the second operating mode, the controller 11 detects said selection and acts on the electric valve 12 and on the auxiliary electric valve 13 in order to allow the fuel to pass through the second through-pipe 5 and through the auxiliary pipe 9 , fuel thus able to reach the burner 2 and the gas pilot 8 . The controller 11 causes said igniter 10 to generate at least one sequence of sparks when fuel is allowed to pass through the auxiliary pipe 9 . The igniter 10 is disposed adjacent to the gas pilot 8 , the sparks causing the gas pilot 8 to light, with the flame of said gas pilot 8 causing the fuel that reaches the burner 2 to light and thereby light said burner 2 , thus heating the cooking surface 1 . Said igniter 10 may also be disposed adjacent to the burner 2 , directly causing said burner 2 to light without the need for the gas pilot 8 , the auxiliary pipe 9 and the auxiliary electric valve 13 .
[0020] Thanks to the control means 11 the second operating mode is flexible, the user being able to select different functions in said second operating mode, such as a timer function or a power control function for example. Thus, the power may be controlled by the cyclical switching on/switching off of the burner 2 for example, the control means 11 acting on the electric valve 12 to allow or prevent the passage of the fuel to said burner 2 , the fuel being allowed to pass through said second through-pipe 5 by means of the control valve 6 . In the case that there is a gas pilot 8 , said gas pilot 8 may remain lit with the control means 11 continuing to allow fuel to pass through the auxiliary pipe 9 , with the result that when fuel is allowed to pass to said burner 2 again there is no need to cause sparks to be generated (or to allow current to pass through the igniter 10 in the case that there is a hot-igniter), the flame of said gas pilot 8 being the one that causes the fuel of the burner 2 to light. If there is no gas pilot 8 , the control means 11 generate sparks (or a current through the igniter 10 ) to cause the fuel of the burner 2 to light. In a preferred embodiment, the barbecue 100 includes a user interface 16 , shown in FIG. 2 , by means of which a user may select desired functions. Said user interface 16 may include a conventional button or key 16 a (or touch pads for example) linked to each function and said functions would be pre-installed in said barbecue 100 , the control means 11 executing the function selected by the user. The user interface 16 may also comprise at least one display 16 b of the type comprising eight segments, for example, and displaying the parameters of at least one of the functions, and buttons or keys 16 c (or touch pads) linked to said display 16 b to increase or reduce the value of the parameter displayed on said display 16 b (of the function selected by the user). In one embodiment, the user interface 16 , the control valve 6 and the flow valve 7 are disposed in a control panel 18 of the barbecue 100 , which is also disposed in a location accessible to the user, such as the front of said barbecue 100 , the side or even the top part, adjacent to the cooking surface 1 .
[0021] The barbecue 100 may also have a thermocouple 14 adjacent to the gas pilot 8 to detect the flame in said gas pilot 8 , and a temperature sensor 15 to detect the temperature of the cooking surface 1 , both the thermocouple 14 and the temperature sensor 15 being connected to the control means 11 . Thus, said control means 11 may determine the presence or absence of a flame in said gas pilot 8 and the temperature of said cooking surface 1 .
[0022] The barbecue 100 may also include supply means, not shown in the figures, to provide electrical power to the controller/control means, said supply means thereby allowing the barbecue 100 to be operated in the second operating mode. Said supply means may comprise a battery disposed in the barbecue 100 or connection means (a plug, for example) to connect said barbecue 100 to an external power source, such as a mains supply, and thereby supply the controller/control means 11 . If the supply means fails or is not available, it will not be possible to operate in the second operating mode, and the user may select the first operating mode to operate the barbecue 100 .
[0023] It is appreciated that the invention may also be used in barbecues with two or more independent cooking surfaces 1 . In this case, each cooking surface 1 may have a control valve 6 , a burner 2 , a first through-pipe 4 , a second through-pipe 5 and a flow valve 7 . The main inlet 3 and the control means 11 may be common to all the cooking surfaces 1 . In this case, the barbecue 100 may also include a gas pilot 8 , an auxiliary pipe 9 and an igniter 10 for each cooking surface, or a gas pilot 8 , an auxiliary pipe 9 and an igniter 10 common to all the cooking surfaces 1 . | A barbecue having a manual operating mode and an automatic operating mode. In the manual operating mode a user is required to act affirmatively on the burner or burners of the barbecue in order to light them. In the automatic operating mode, a controller operably controls an igniter and/or a pilot to automatically light the burner or burners without the need for a user to affirmatively act on the burners themselves. | 0 |
The present invention relates generally to medical electrodes and connectors for effecting an electrical connection between the skin of a patient and electromedical devices such as electrocardiographs and the like. More particularly, it relates to an improved electrode-connector assembly utilizing magnetic means to effect connection.
In recent years a variety of disposable skin electrodes have been introduced into the medical field. Generally, these electrodes are adhesively secured to the skin of the patient and contain a male terminal or "stud" which is adapted to snap into a female terminal in the connector. A lead wire attached to the female terminal completes the electrical connection between the male terminal and the electromedical device. The stud portion of the electrode is generally connected to a metallic plate which is in turn connected to the skin by means of an electrically conductive material such as an electrolyte gel.
The major disadvantage associated with these "snap on" connectors is that a relatively large amount of downward force is required to mate the male portion of the electrode with the female portion of the connector. If the mating is accomplished after the electrode has been secured to the skin of a patient, the downward force often results in a spreading of the electrolyte gel. Spreading of the gel may adversely affect the electrical connection to the skin, shorten the useful life (application time) and also interfere with and weaken the adhesive which holds the electrode on the skin. A further problem involves discomfort to the patient resulting from applying pressure to a sensitive area of the body. Therefore, it has generally been necessary to mate the electrode and connector prior to securing the electrode to the skin. This method is more cumbersome and less efficient.
The problem associated with snap on connector described above has been somewhat alleviated by the use of a clamp connector such as that described in U.S. Pat. No. 3,840,703. This clamp connector has a "clothespin" design, and the user squeezes on the arms of the connector until the opening is large enough to fit around the male portion of the electrode. No downward pressure is required. However, this type of connector can in certain situations be disconnected from the electrode by accidental bumping or by applying tension on the lead wire. It is not well suited for long term monitoring of patients who enjoy freedom of movement.
By utilizing magnetic means to effect connection between the electrode and the connector, the present invention overcomes a major disadvantage associated with prior art skin electrodes and connectors. By using magnetic force to mate the male portion of the electrode with the female portion of the connector, no downward force on the electrode is required.
The use of magnetic means to effect electrical contact is known. U.S. Pat. No. 3,810,258 describes a quick connect electrical coupler comprising a male coupling half and a female coupling half. Each half contains electrical contact means and a permanent magnet. A conical projection in the male half mates with a matching recess in the female half to insure easy alignment when the two halves are assembled.
U.S. Pat. No. 3,964,470 describes a percutaneous intradermal electrical connection system and implant device. The lower portion of the implant device is located beneath the surface of the skin. The upper portion of the implant device contains a cavity which receives an extension of the connector to provide mechanical and electrical contact between the implant device and the connector. In one embodiment, the connection is achieved by magnetic means.
SUMMARY OF THE INVENTION
The present invention provides an improved skin electrode and connector assembly. The electrode portion of the assembly comprises a ferromagnetic electrode plate and an upstanding contact member firmly affixed to the electrode plate, some portion of which forms an electrical contact surface with the connector. Means are provided to adhesively attach the electrode plate to the surface of the skin in a manner that provides secure attachment and good electrical coupling for conducting electrical impulses between the skin and the electrode plate.
The connector portion of the assembly comprises a magnet having a hole in its lower surface for mating with the upstanding contact member, and a lead wire electrically connected to the magnet. The hole in the lower surface of the magnet is formed so that, when mated with the upstanding contact member of the electrode, electrical contact between the electrode and the connector is made on some portion of the upstanding contact member, and a small space is provided between the lower surface of the connector and the top surface of the electrode plate.
The term "ferromagnetic" as used herein refers to any magnetically-responsive material.
The electrode-connector assembly of the present invention provides numerous advantages over those of the prior art. Since the connection between the electrode and the connector is accomplished by magnetic means, no downward pressure on the electrode is required to mate the connector with the electrode, and the connection can be conveniently made after the electrode is in place on the patient's skin.
The mating parts are automatically aligned with the upstanding contact member enters the mating hole in the connector. When mated, the upstanding contact member prevents lateral displacement of the connector and thereby minimizes the possibility of accidental disconnection by tension on the lead wire. Since the connector can be rotated through a 360° angle about the contact member, torsional forces on the lead wire do not interfere with the electrical connection and the patient enjoys greater freedom of movement.
The major improvement in the electrode-connector assembly of the present invention resides in the mating arrangement between the connector and the electrode. The upstanding contact member of the electrode and the mating hole of the connector are designed so that, when mated, contact between the connector and the electrode occurs on some portion of the upstanding member and not on the surface of the electrode plate. The surface of the electrode plate is separated from the lower portion of the connector by a small space. In this manner, electrical contact between the mating parts is improved because the contact pressure is concentrated over a small surface area. There is less chance of dust and debris collecting on the contact surface to interfere with electrical contact. Additionally, the existence of a small air space between the connector and the electrode plate allows the electrode to be more efficiently and economically constructed. The entire top surface of the electrode plate (except for a hole to accommodate the upstanding contact member) can be covered with an adhesive strip for attaching the electrode to the skin.
The most preferred embodiment of the invention provides an additional improvement over magnetic connectors of the prior art. In this embodiment, the upstanding contact member of the electrode comprises an elongated cylindrical member or "pin." The mating hole of the connector is formed so that when the pin and hole are mated there is sufficient clearance between the pin and the wall of the hole to allow the connector to be tilted and lifted off the pin by upward force on the edge of the connector opposite the lead wire, but insufficient clearance to allow the connector to be lifted off the pin by upward force on the lead wire. Upward force on the lead wire causes the pin to intercept the wall of the hole and prevent disconnection. In this embodiment, lifting means are provided on the edge of the connector opposite the lead wire.
This improvement allows easy disconnection of the connector from the electrode by breaking the magnetic force field at one edge. In this manner, considerably less force is required than if disconnection is made by straight axial pull across the full magnetic field. Thus, intentional disconnection is facilitated, but accidental disconnection by upward force on the lead wire is prevented. Although it is most preferred to practice this improvement together with the improvement wherein electrical contact between the connector and the electrode occurs on some portion of the upstanding contact member, these improvements may be practiced separately.
DESCRIPTION OF THE DRAWINGS
Understanding of the invention will be facilitated by reference to the accompanying drawings wherein:
FIG. 1 is a sectional view of the connector portion of the assembly and the upper portion of the electrode.
FIG. 2 is a sectional view of the connector and upper portion of the electrode illustrating the improved locking and disconnect features of the invention.
FIG. 3 is a sectional view of the preferred embodiment of the electrode-connector assembly on the skin of a patient.
FIG. 4 is a plan view of the top of the connector-electrode assembly.
FIG. 5 is a plan view of the bottom of the connector portion of the assembly.
FIG. 6 is an enlarged sectional view of the connector and upper portion of electrode shown in FIG. 3.
FIG. 7 is a sectional view of the connector and upper electrode showing the connector being disconnected from the electrode by use of the lifting means.
FIG. 8 is a sectional view of the connector and upper electrode showing the effect of applying upward tension to the lead wire.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1 connector 10 is magnetically and electrically connected to electrode 12. Connector 10 comprises a magnet 14 having a hole 16 in the lower surface thereof for mating with projecting portion of the electrode and a lead wire 18 electrically connected to the magnet. Lead wire 18 is encased in a protective sheath 19 and connects to an electrocardiograph or the like in the conventional manner.
The electrode 12 of the assembly shown in FIG. 1 comprises an electrode plate 20 of ferromagnetic material and an upstanding contact member 22 firmly affixed thereto. In this embodiment, the upstanding contact member 22 is a cone-shaped projection. The diameter of mating hole 16 at its opening is smaller than the diameter of upstanding contact member 22 at its base. Consequently, when the parts are mated, electrical contact between the connector and the electrode is made on the tapered surface of the upstanding contact member, and space 24 is provided between the upper surface of electrode plate 20 and the lower surface of connector 10.
The assembly of FIG. 2 illustrates the improved locking and easy disconnect feature of the invention. In this embodiment, connection 10 comprises magnet 14 which is in the shape of a washer. The sides and upper surface of magnet 14 are surrounded by ferromagnetic shell 26. Ferromagnetic shell 26 surrounds the magnet in a cup-like fashion. "Cup" magnets of this type are well known in the art. The ferromagnetic cup causes the magnetic flux to be intensified at the edge of the magnet, thereby multiplying the holding force of the magnet. Cup magnets of this type are especially preferred for use in the connectors of the present invention because strong magnetic holding force can be achieved while keeping the size of the connector at a minimum.
The size of the magnet may vary depending upon the desired use of the electrode-connector assembly. In general, the magnet should provide a holding force of at least 250 grams, and, preferably, about 1000 grams. It has been found that a samarium cobalt magnet in the form of a washer 0.5 mm thick and 10 mm in diameter works well for most purposes. Using a magnet of this kind, a small, compact connector having a diameter of about twelve millimeters and a thickness of about 4 millimeters can be made.
Connector 10 has a hole 16 in the lower surface thereof for mating with the projecting portion of the electrode. Lead wire 18 is connected to one side of the connector and the opposite side of the connector has lifting means 28, illustrated as a projecting lip, for applying upward pressure with the thumb or finger to disconnect the connector from the electrode.
In the embodiment shown in FIG. 2, the upstanding contact member 22 is shown as a cylindrical member or pin firmly affixed to the electrode plate 20. This pin mates with hole 16 of the connector. Hole 16 is formed so that there is sufficient clearance between the wall of the hole and the pin to allow the connector to be tilted and lifted off the pin by applying upward force on lifting means 28. Clearance may be provided by outward tapering of the wall of hole 16 on the side adjacent to lifting means 28. It is obvious, however, that other configurations of the hole are possible to accomplish the same result. There is insufficient clearance between the pin and wall of the hole to allow the connector to be tilted and lifted off the pin by upward force on the lead wire. If the connector is tilted from the lead wire side, the pin will intercept the wall of the hole and prevent disconnection. This improvement prevents accidental disconnection by way of the lead wire, yet intentional disconnection is facilitated by way of the lifting means.
In FIG. 2, electrical contact between the connector and the electrode occurs on the surface of the electrode plate and no space is provided between the connector and the electrode plate. Although this embodiment is less preferred, it illustrates that the locking and easy disconnection feature can be practiced separately from the improved electrical contact feature shown in FIGS. 1, 3 and 6-8.
FIG. 3 illustrates the preferred embodiment of the electrode-connector assembly of the invention containing both the improved electrical contact feature and the improved locking and easy disconnection feature.
Connector 10 comprises magnet 14 in the shape of a washer, the top and sides of which are surrounded by ferromagnetic shell 26 to form a cup magnet. Lead wire 18 is connected to one side of connector 10 and lifting means 28 extends from the opposite side of the connector from the lead wire. Connector 10 has a hole 16 in the lower surface thereof for mating with the projecting portion of the electrode.
Electrode 12 comprises electrode plate 20 of ferromagnetic material and an upstanding contact member or pin 22 firmly affixed thereto. Pin 22 has an elongated cylindrical body portion 30 and a beveled base portion 32. The diameter of mating hole 16 at its opening is less than the diameter of beveled base portion 32 of the pin. Consequently, when the connector and electrode are mated, the contact surface between the two is on the beveled base portion of the pin, and a space 24 is provided between the lower surface of the connector and the upper surface of electrode plate 22.
Hole 16 is formed so that when mated with pin 22, there is sufficient clearance between the pin and the wall of the hole to allow the connector to be tilted and lifted off the pin by applying upward force on lifting means 28. There is insufficient clearance between pin 22 and the wall of hole 16 to allow the connector to be tilted and lifted off the pin by applying upward force on the lead wire.
The lower surface of the electrode plate 20 is provided with electrical conducting means to conduct electrical impulses from the skin to the electrode plate. The electrical conductive means may consist of a porous pad containing conductive gel. Pregelled electrodes of this type are well known in the art. It is also well known in the art that pregelled electrodes are preferably packaged with a seal around the gel pad to keep the gel moist. Packaged pregelled electrodes are described in U.S. Pat. No. 3,805,769.
In FIG. 3, the electrical conducting means is illustrated as an electrically conductive pressure sensitive adhesive 34 such as that described in U.S. Pat. No. 3,911,906. The electrode is affixed to the skin by means of an adhesive strip 36 which is placed over the upper surface of the electrode plate 26 and partially fills the space between the connector and the electrode. Adhesive strip 36 extends outwardly beyond the perimeter of the electrode plate 26 so as to attach to the skin and hold the electrode firmly in place.
In operation, the electrode is placed on the skin of the patient which is generally prepared by cleaning and abrading. The electrical conductive material improves the electrical connection and reduces resistance between the skin and the electrode plate. The electrode is securely fastened to the skin by the adhesive strip. The connector is then connected to the electrode by mating with the upstanding contact member. The lead wire of the connector is connected to the monitoring device in the conventional manner.
FIG. 4, shows a top view of the electrode-connector assembly of FIG. 3. The top of connector 10 shows ferromagnetic shell 26 with sheath 19 containing the lead wire 18 attached to one side and lifting means 28 extending outward from the opposite side. Adhesive strip 36, which secures the electrode to the skin, is seen extending from the periphery of the connector.
FIG. 5 is a bottom view of the connector showing ferromagnetic shell 26 and the magnet 14 therein. Hole 16 in the center of the connector mates with the upstanding contact member of the electrode. Sheath 19 containing lead wire 20 enters the connector on one side and lifting means 28 extends from the opposite side of the connector.
FIG. 6 is an enlarged view of the connector and the upper portion of the electrode shown in FIG. 5. FIGS. 7 and 8 illustrate the effect of applying upward force on lifting means 28 and lead wire 18, respectively, when the connector and electrode are mated.
In FIG. 7, it is seen that by expanding the clearance or relief space between the pin 22 and the wall of hole 16 on the side adjacent to lifting means 28, the connector can be removed from the pin by applying upward force on lifting means 28. In this manner the magnetic force field holding the mating parts together can be broken at the edge, and considerably less force is required to disconnect the parts than if the connector is removed by straight axial pull across the entire force field.
In FIG. 8 it is seen that accidental disconnection of the mating parts by applying upward force on the lead wire is prevented by reducing the clearance or relief space between pin 22 and the wall of hole 16 on the side adjacent to the lead wire. Upward force on lead wire 18 causes pin 22 to intercept the wall of hole 16 and thereby interfere with further tilting and removal of the connector from the pin.
The electrode-connector of the present invention is especially suited for obtaining electrocardiograms and other biomedical monitoring such as electromyograms and electroencephalograms.
The electrode-connector assembly of the invention is easy to use and results in minimal discomfort to the patient. Connection of the mating parts is effortlessly made through the use of magnetic connecting means. Electrical contact between the parts is improved by concentrating the magnetic holding force over a small surface area. In addition, the chances of accidentally disconnecting the parts during monitoring is reduced by the locking features of the assembly, yet, intentional disconnection at the end of the monitoring period is facilitated by the special disconnect feature. | An improved biomedical electrode and connector assembly is disclosed wherein the connector contains a magnet to facilitate mating with an elongated upstanding contact member of the electrode. Electrical contact between the connector and the electrode occurs along some portion of the upstanding contact member so that a space or gap is formed between the connector and the electrode plate of the electrode. Apparatus whereby the connector may be intentionally disconnected with ease, but accidental disconnection is prevented, are also provided. | 8 |
RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 11/594,376, filed Nov. 8, 2006 now U.S. Pat. No. 7,322,288, entitled METHOD AND APPARATUS FOR PERFORMING OPERATIONS WITHIN A STENCIL PRINTER, which is a continuation of U.S. patent application Ser. No. 11/265,018, filed Nov. 2, 2005, entitled METHOD AND APPARATUS FOR PERFORMING OPERATIONS WITHIN A STENCIL PRINTER, now U.S. Pat. No. 7,171,898, which is a continuation of U.S. patent application Ser. No. 10/783,123, filed Feb. 19, 2004, entitled METHOD AND APPARATUS FOR SIMULTANEOUS INSPECTION AND CLEANING OF A STENCIL, now U.S. Pat. No. 7,013,802, each of which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The invention relates to apparatus and methods for screen printing, and more specifically to apparatus and methods for the screen printing of electronic substrates such as circuit board assemblies.
BACKGROUND OF THE INVENTION
The manufacturing of circuit boards involves many processes, one of which is the screen printing of solder paste or other adhesives on the surface of a circuit board so that electronic components can thereafter be deposited onto the board. The boards typically have a pattern of pads or some other conductive surface onto which solder paste will be deposited. To accomplish the deposition of solder paste, a stencil is created that has an aperture or a plurality of apertures defining a pattern to be printed on the surface of the board. The solder paste or other adhesive to be deposited on the board is placed on top of the stencil for deposition into the aperture or apertures. A squeegee or wiper blade is passed over the stencil and forces the solder paste into the apertures. Excess solder paste may then be removed from the top of the stencil so that substantially all of the solder paste that remains is in the aperture or apertures. The stencil is then separated from the board and the adhesion between the board and the solder paste causes most of the material to stay on the board. Material left on the surface of the stencil is removed in a cleaning process before additional circuit boards are printed.
Another process in the printing of circuit boards involves inspection of the boards after solder paste has been deposited on the surface of the boards. Inspecting the boards is important for determining that clean electrical connections can be made. An excess of solder paste can lead to shorts, while too little solder paste in appropriate positions can prevent electrical contact. Generally, a vision inspection system is employed to provide a two-dimensional or a three-dimensional inspection of the solder paste on the board.
The stencil cleaning process and the circuit board inspection process are merely two of a number of processes involved in producing circuit boards. To produce the greatest number of circuit boards of consistent quality, it is often desirable to reduce the cycle time necessary to manufacture circuit boards, while maintaining systems that ensure the quality of the boards produced, such as the board inspection and stencil cleaning systems.
SUMMARY OF THE INVENTION
In general, in one aspect, the invention provides an apparatus for cleaning a surface of a stencil while simultaneously inspecting a solder paste deposits on a circuit board. The simultaneous activities of cleaning and inspecting are accomplished by translating the stencil over a fixed stencil wiper, and with the stencil removed from a position over the surface of the circuit board, a vision inspection system can be moved into position to inspect the board. Alternatively, a vision inspection system can inspect the board while the stencil is in a position over the board. Thus, inspection is possible while the stencil is in place over the board or substantially simultaneously with the wiping of the stencil. Aspects of the invention provide improved efficiency during circuit board production.
Embodiments of the invention provide an apparatus for performing operations on a surface of an electronic substrate. The apparatus includes a frame, a dispenser, coupled to the frame, to dispense a material onto the electronic substrate, a stencil moveable on a gantry system having at least one aperture to receive the material as the material is dispensed on the substrate, a controller that controls dispensing of the material on the substrate, and a wiper to remove material from the stencil as the stencil is translated away from the electronic substrate by the gantry system.
Implementations of the invention can include one or more of the following features. The wiper can be fixed in position. The stencil can be moved on the gantry system over a position of the wiper. The apparatus can further include an inspecting probe coupled to a second gantry system for inspecting a surface of the substrate. The inspecting probe can be moveable to a position over the electronic substrate. The stencil can translate over the fixed wiper substantially simultaneously with the inspection of the electronic substrate.
Embodiments of the invention further provide a method for performing a printing operation on a surface of a substrate. The method includes transporting the substrate into a position for printing a material onto the substrate, aligning the substrate and a stencil, the stencil having at least one aperture to receive the material as the material is deposited onto the substrate, depositing the material through the stencil and onto the substrate, and translating the stencil from a position over the surface of the substrate, over a fixed wiper positioned to remove a residual material from the surface of the stencil as the stencil is translated.
Implementations of the invention may include one or more of the following features. The method may further comprise inspecting the substrate using a video probe inspecting system. The steps of inspecting and translating can occur substantially simultaneously. The method may also comprise transporting a second substrate to a printing position while translating the stencil over the fixed wiper.
A still further embodiment of the present invention comprises a method for simultaneously inspecting an electronic substrate and cleaning a stencil in a stencil printer. The method includes positioning the stencil above the electronic substrate, depositing a material on the electronic substrate, separating the stencil and the electronic substrate, translating the stencil to a position removed from the area over the circuit board, inserting an inspecting system in a space occupying the area from which the stencil was removed, and inspecting the electronic substrate while translating the stencil over a fixed wiper for cleaning.
The invention will be more fully understood after a review of the following figures, detailed description and claims.
BRIEF DESCRIPTION OF THE FIGURES
For a better understanding of the present invention, reference is made to the drawings which are incorporated herein by reference and in which:
FIG. 1 is a perspective drawing of a screen printer in one embodiment of the invention;
FIG. 2 a is a top view of the printer of FIG. 1 in a print load phase in one embodiment of the invention;
FIG. 2 b is a top view of the printer of FIG. 1 in an align print and exit completed circuit board phase in one embodiment of the invention;
FIG. 2 c is a top view of the printer of FIG. 1 in a printing phase in one embodiment of the invention;
FIG. 2 d is a top view of the printer of FIG. 1 in a stencil wipe and inspect phase in one embodiment of the invention;
FIG. 2 e is a top view of the printer of FIG. 1 in a complete wipe and exit phase in one embodiment of the invention;
FIG. 2 f is a top view of the printer of FIG. 1 in a wipe and load print phase in one embodiment of the invention;
FIG. 2 g is a top view of the printer of FIG. 1 wipe and align print phase for a second circuit board in one embodiment of the invention; and
FIG. 3 is a side view of a portion of the printer of FIG. 1 according to one embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Embodiments of the present invention are described below with reference to screen printers or stencil printers used to produce printed circuit boards. As understood by those skilled in the art, embodiments of the present invention can be used with electronic substrates other than circuit boards, such as electronic components, and with machines other than screen printers such as pick and place machines or dispensing machines.
Referring to FIG. 1 , a printer 100 in accordance with one embodiment of the invention that applies solder paste or other materials to substrates, such as circuit boards, is shown. The printer is an improvement over the screen printers described in U.S. Pat. No. 6,324,973, which is hereby incorporated by reference.
As shown in FIG. 1 , the printer 100 includes a frame 102 , a controller 104 , a stencil 106 , solder paste cartridges 110 , a dispensing head/squeegee 108 , a board support mechanism 122 , a tractor feed mechanism 114 and a circuit board 116 . The circuit board enters the printer 100 on the tractor feed mechanism 114 . The stencil 106 is attached fixedly to the frame 102 in a position above the position in which the circuit board 116 will enter the printer on the tractor feed mechanism 114 . The dispenser head/squeegee 108 is in proximity to the solder paste cartridges 110 and is attached to the printer 100 in a position above the solder stencil 106 . The solder stencil 106 has apertures through which solder is deposited on the surface of a circuit board. The controller 104 is internal to the mechanisms of the printer 100 . The controller is configured to receive signals from operations in the printer, such as alignment of the board, movement of the stencil, and deposit of the solder paste, and control the printer accordingly.
Circuit boards 116 fed into the printer 100 typically have a pattern of pads or other, usually conductive surface areas onto which solder paste will be deposited. When directed by the controller of the printer, the tractor feed mechanism 114 supplies boards to a location over the board support mechanism and under the stencil 106 . Once arriving at the position under the stencil 106 , the circuit board 116 is in place for a manufacturing operation. To successfully deposit solder paste on the circuit board 116 , the circuit board 116 and the stencil 106 are aligned, via the controller. Alignment is accomplished by moving the stencil or circuit board based on readings from the vision inspection system, discussed below. When the solder stencil 106 and the circuit board 116 are aligned correctly, the stencil is lowered toward the board 116 for application of the solder paste through the apertures, or the circuit board can be raised toward the stencil by the support mechanism 122 .
The pattern of the apertures on the stencil corresponds to the pattern of conductive surfaces or pads already on the circuit board 116 . The dispenser head/squeegee 108 , positioned above the stencil 106 , can vary the amount of solder paste delivered on the stencil 106 and applied by the squeegee. The squeegee 108 wipes across the stencil, thereby pushing solder paste into the stencil apertures and onto the board 116 . Solder paste remains on the circuit board 116 in the preset pattern when the support mechanism supporting the board moves downward away from the position of the stencil, or the stencil moves upward away from the board, under control of the controller. The surface tension between the circuit board 116 and the solder paste causes most of the solder paste to remain on the circuit board when the circuit board 116 and the stencil 106 are separated. A vision inspection system then moves into position over the circuit board 116 to inspect the solder paste deposits to determine whether the solder paste has been accurately placed on the circuit board. Inspection aids in ensuring that the proper amount of material has been deposited and that the material has been deposited at the proper locations on the circuit board. The vision inspection system can use fiducials, chips, board apertures, chip edges, or other recognizable patterns on the circuit board to determine proper alignment. After inspection of the circuit board, the controller controls movement of the circuit board 116 to the next location using the tractor feed mechanism, where electrical components will be placed on the circuit board 116 .
In addition to vision inspection of the circuit board upon completion of the deposition of solder paste onto the circuit board, in one embodiment of the invention, the stencil is cleaned using a wiper to remove excess solder paste from the surface of the stencil prior to beginning a print cycle on a next circuit board. Generally, in known printers, the wiper used to clean the stencil moves over the surface of the stencil after printing has occurred. Removal of excess solder paste can occur after each print cycle, or after a number of print cycles when it has been determined that a substantial amount of solder paste is on the surface of the stencil and should be removed. Additionally, before the circuit board can move to a next print operation in the printer or otherwise, the circuit board is inspected to determine the accuracy with which solder paste has been deposited on the surface of the circuit board.
To accomplish improvements and efficiency in the print cycle, the board inspection process and the stencil cleaning process occur substantially in parallel. During the inspection of at least one of the printed boards, the stencil is moved to a position where a stencil wipe process occurs.
Referring to FIGS. 2 a - 2 g , like numbers referring to like elements, in each of the FIGS. 2 a - 2 g , as each represents a printer in a different phase of printing. In FIGS. 2 a - 2 g , the printer of FIG. 1 is shown in a series of top perspectives. In FIGS. 2 a - 2 g , the wiper remains fixed in position while the stencil is in motion. In FIGS. 2 a - 2 g , the printer 100 includes the stencil 106 , the squeegee 108 , the circuit board 116 , a vision probe 130 , a vision gantry 132 , and a fixed wiper 134 . The vision probe 130 is coupled to the vision gantry 132 , which is coupled to the frame of the printer 100 . The vision probe 130 is located between the stencil 106 and the circuit board 116 . The vision probe 130 moves into position over the circuit board 116 via a vision gantry system. The squeegee 108 is coupled to the frame in a position above the stencil 106 .
In FIG. 2 a , the circuit board 116 is loaded into the printer 100 . In FIG. 2 b , the circuit board 116 and the stencil 106 are aligned. Alignment of the stencil 106 and the circuit board 116 is accomplished by using the vision probe 130 . The vision probe can be, for example, the vision probe discussed in U.S. Pat. No. 5,060,063, entitled, “Viewing and illuminating video probe with viewing means for simultaneously viewing object and device images along viewing axis and translating them along optical axis,” which is assigned to the assignee of the present invention and is herein incorporated by reference. Also incorporated by reference in its entirety is U.S. Pat. No. RE35,615 entitled, “Video Probe Aligning of Object to be Acted Upon,” which further discusses aspects of the vision probe of the present invention. Once aligned, the vision probe 130 is moved from its position to a resting position via the vision gantry 132 , and the circuit board 116 and the stencil 106 come into contact, or substantially close proximity for printing, as shown in FIG. 2 c . Printing of solder paste occurs as the squeegee 108 translates over the surface of the stencil 106 and deposits solder paste through the apertures of the stencil 106 , onto the circuit board 116 . The squeegee 108 can make a full forward sweep and come to a resting position in preparation for a next circuit board 116 . Alternatively, the squeegee 108 can deposit solder paste on the circuit board and return to its starting position.
With solder paste deposited on the surface of the circuit board 116 , the circuit board 116 separates from the stencil 106 by dropping away from the surface of the stencil, shown in FIG. 2 d . Alternatively, the stencil can be moved upward away from the surface of the circuit board 116 . Having completed printing, the stencil translates, for example toward the back of the printer 100 , to be cleaned. While in most known systems the stencil is fixed in position, in the present printer 100 , the stencil can move in a forward and backward motion. The stencil is cleaned by moving from front to back over the surface of the wiper 134 , as the wiper contacts the surface of the stencil and removes excess solder paste. The stencil moves to the back and over the surface of the wiper by moving backward in the printer 100 , i.e., in the negative Y axis direction, and the stencil moves back into position by moving forward in the positive Y axis direction. This motion is the translation of the stencil, although it is possible that translation of the stencil in the printer 100 may occur in the X axis direction alternatively or additionally. The wiper 134 may be fixed in position to a side of the track 136 , which is the track along which the circuit board is transported. The wiper 134 generally contacts the bottom or undersurface of the stencil where deposits of material may become built up. Preferably, the wiper 134 is positioned toward the rear of the printer 100 so as not to interfere with the operation of the stencil and vision system. The stencil 106 is positioned at a level above the wiper 134 . As the stencil translates rearward, the wiper 134 cleans the surface of the stencil by contacting the stencil while the stencil travels over the wiper and removes the residual solder paste.
Referring to FIG. 3 , a side view of the process described in FIG. 2 a - 2 g is shown. From this view, it is more clearly shown that the stencil 106 moves in a forward and backward direction indicated by arrow 190 . As the stencil 106 moves from the first position over the circuit board 116 , it contacts the fixed wiper 134 , leaving a substantial space over the position of the circuit board 116 . Thus, the stencil can move in a first direction that is substantially perpendicular to the position of the circuit board, and in a second planar position substantially parallel to the position of the circuit board.
With continued reference to FIG. 3 , and referring again to FIG. 2 d , during the time in which the stencil is cleaned by the wiper 134 , or substantially simultaneously, the vision probe 130 moves into a position over the surface of the circuit board 116 to perform an inspection task. The vision probe moves in a forward and back motion as indicated by arrow 192 . The vision probe 130 is restricted in its movements to a position over the circuit board while the stencil is being cleaned, since the stencil is moved toward the rear of the printer 100 , allowing a substantial space over the circuit board for the vision probe 130 to inspect. Thus, wiping of the stencil and inspection of the circuit board may be accomplished in parallel. However, it may not be necessary to clean the stencil after each print cycle, so inspection can occur independently of the cleaning of the stencil.
Referring to FIG. 2 e , upon completion of inspection, the circuit board 116 exits the printer 100 . The circuit board 116 can exit the printer while the stencil continues to be cleaned. The printing of a first circuit board 116 is thereby completed, and the circuit board can continue to a next manufacturing cycle. The printer 100 is prepared to accept a new circuit board 116 via tracks 136 , as is shown in FIG. 2 f , and a next print cycle can begin.
While the next circuit board 116 moves into position in the printer, the stencil wipe process is completed and the stencil 106 moves towards the front of the printer 100 to begin the printing cycle for the new circuit board, as is shown in FIG. 2 g.
The process of printing a circuit board including stencil wipe and circuit board inspection as depicted in FIGS. 2 a - 2 g can be repeated any number of times to correspond to the number of boards in need of the printing of solder paste. The process may be required at the completion of the printing of a single circuit board 116 , or it may be completed after a predetermined number of circuit boards 116 are printed, as inspection and cleaning may not be necessary after each print cycle.
Due to the relative positioning of the stencil and the vision probe, and the ability of the stencil to translate toward the back of the printer, substantially simultaneous operations can occur, thereby reducing the cycle time necessary to complete the printing operation. In addition to improving the cycle time, quality is not compromised, as the circuit boards continue to be inspected. For example, in some printing cycles, a typical inspection task may take from 20 to 60 seconds to accomplish. Wiping of the stencil may occur over a duration of 40 to 60 seconds, depending on the type of wipe process in use. Therefore, with the inspection and the stencil wipe working in parallel, both processes may be completed in one minute or less, saving on the order of ½ to 1 minute in cycle time. These cycle periods are exemplary only and may vary depending on the print cycle characteristics for each machine or product.
Embodiments of the invention describe a fixed wiper positioned below the stencil that cleans the bottom surface of a stencil when the stencil is translated over the wiper blade. In other embodiments of the invention, a wiper is fixed above the surface of the stencil to likewise clean the top surface of the stencil. In still further embodiments of the present invention, the stencil translates to a position over the wiper, and the wiper translates orthogonal to the motion of the stencil when the stencil has moved to be positioned over the wiper. In still further embodiments of the invention, more than one wiper is fixed in a position below the stencil for cleaning. Other positions of the wiper in relation to the stencil are envisioned.
In embodiments of the invention, the vision inspection probe moves on a gantry system to inspect the board after deposition has occurred. In other embodiments of the invention, after inspection of the first board, a second board loaded into position for printing can be properly aligned using the vision system, while the stencil continues to be cleaned.
Having thus described at least one illustrative embodiment of the invention, various alterations, modifications and improvements will readily occur to those skilled in the art. Such alterations, modifications and improvements are intended to be within the scope and spirit of the invention. Accordingly, the foregoing description is by way of example only and is not intended as limiting. The invention's limit is defined only in the following claims and the equivalents thereto. | An apparatus for performing operations on a surface of an electronic substrate comprises a frame, a dispenser, coupled to the frame, to dispense a material onto the electronic substrate, a stencil moveable on a gantry system having at least one aperture to receive the material as the material is dispensed on the substrate, a controller that controls dispensing of the material on the substrate, and a wiper to remove material from the stencil as the stencil is translated away from the electronic substrate by the gantry system. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates in general to the field of textile manufacturing and in particular to a method of making textile articles possessing specific levels of durable antimicrobial activity in accordance with the requirements for particular applications.
2. Description of the Related Art
Textile articles composed of various fibers and/or polymers are used in many applications for which the possession of antibacterial activity would be desirable. For example, such articles and applications may include clothing, fabrics, and linens for use in hospitals, polymer-based materials for use in biomedical research, and woven cloth or metal fibers for use in sanitation or cleaning.
One method of imparting antimicrobial activity to textiles utilizes the addition of antibacterial chemical compounds, such as triclosan. However, one problem with treating textiles with antibacterial chemicals is that such compounds tend to wash out, wear out, or otherwise dissipate after relatively little use.
A means of impregnating a more durable antibacterial activity into textile articles has been accomplished through the addition of a substance known as zeolite. Zeolite is a volcanic rock predominantly made of aluminosilicate which is solvated by calcium and sodium cations. When zeolite is crushed into fine particles and added to a mixture of silver, copper, or zinc salts, the calcium and sodium cations in the aluminosilicate are replaced by silver, copper, or zinc metallic cations to form a compound known as “modified zeolite.”
Experiments with modified zeolite demonstrated that the metallic cations, when ionized by the humidity in the surrounding ambient, produce intense electrical fields. These electrical fields lead to the release of oxygen, which has significant antibacterial effects. Furthermore, the metal cations of modified zeolite are capable of chemically mixing with bacterial cell walls, thereby causing growth disruption or destruction of bacterial cells.
It is known that these antibacterial properties can be customized to affect specific microorganisms. Depending on the chemical structure of their cell wall, particular types of bacteria can be disrupted or destroyed according to the metal salt used in the formation of modified zeolite. For example, copper or zinc cations act upon the cell wall of Gram-positive bacteria, whereas silver cations act upon the cell wall of Gram-negative bacteria.
U.S. Pat. No. 4,775,585 by Hagiwara et al. describes a polymer article containing zeolite particles in which a metal ion having bactericidal activity is incorporated in the zeolite by an ion exchange reaction. The polymer article is produced either by admixing metal-ion-containing zeolite particles with a polymer or by molding a zeolite-containing polymer into an article and then treating the article with a metal ion solution. The textile articles made by this method contain between 0.01% and 10% by weight zeolite particles that possess at least one metal ion in an amount less than 92% of the total ion exchange capacity of the zeolite.
However, the antibacterial fiber derived by the method described in the '585 patent has been difficult to exploit in the production of useful articles. Depending on the size and mix of the fibers used, the resulting fabrics have often been unpredictably ineffective or excessively active. For example, a mixture of an apparently adequate percentage of antibacterial fiber with an inert fiber might unexpectedly produce a low-efficacy fabric. Similarly, the resulting fabric might be so active as to destroy all forms of bacteria within its touch, which would render the product unacceptable for use in contact with human skin.
The method of Hagiwara et al. produces textile articles that have undefined levels of antibacterial activity; therefore, they must be tested to determine their level of antibacterial efficacy and the prior art does not provide any teaching for predicting it as a function of textile-design parameters. As will be described hereinafter, the present invention, among other advantages, provides a method of predicting antibacterial properties, thus eliminating the need for efficacy testing of the textile once the properties of the component fibers are known. Nothing has been taught in the prior art to predict the spatial effect of antibacterial fibers and to enable the design of fabrics with a predetermined antibacterial efficacy. The present invention is directed at providing such teachings.
BRIEF SUMMARY OF THE INVENTION
It is an object of the invention to provide a method of making textiles impregnated with a predetermined amount of durable antibacterial material to afford a desired degree of antibacterial activity without the need for laboratory testing of the finished article.
A further object of the invention is to provide a method of making antibacterial textiles possessing specific bacterio-static levels of antibacterial activity.
Another object of the invention is to provide a method of making antibacterial textiles possessing specific bactericidal levels of antibacterial activity.
Still another object of the invention is to provide a method of making textiles so that they contain the minimum amount of modified zeolite necessary to achieve a desired level of antibacterial activity so as to optimize manufacturing costs.
Moreover, another object of the invention is to provide a method of making antibacterial textiles that contain a minimum of modified zeolite so as to preclude allergenic or otherwise irritating reactions resulting from contact with the skin or mucus membranes.
Yet another object of the invention is to provide a method of making durable antibacterial textiles produced with a maximal amount of non-zeolite-treated natural fibers that are comfortable to wear or touch.
To accomplish these objectives, the invention utilizes novel, empirically determined models that allow the predetermination of the accurate amount and quality of modified zeolite required to produce textile articles having a specific degree of antibacterial activity in accordance with the requirements for particular applications.
One advantage of the present invention is that it minimizes the time and expense of testing newly made textile articles for the presence of bactericidal and/or bacterio-static activity. For this purpose, the invention utilizes equations that accurately predict the relationship between the amount and spatial orientation of modified-zeolite-containing polymers or fibers and the desired degree of antibacterial activity.
Some textiles possess antibacterial activity derived from chemicals that can cause allergy. Moreover, the amount of antimicrobial material that is incorporated into an article, or the chemicals used to affix antimicrobial material to an article, can lead to skin irritation, rashes, or other types of allergenic responses. This is particularly troublesome given the fact that many textiles are worn, held, or are otherwise in bodily contact for long periods of time. Thus, another advantage of the present method is that one can calculate the minimum amount of antimicrobial material necessary to impart a desired level of antibacterial activity, making the textile less irritating or allergenic.
Antibacterial textile articles typically are made from large amounts of modified-zeolite-treated polyester or other synthetic polymers. To provide antibacterial textile articles that are more comfortable, the invention can be utilized to maximize the amount of cotton, silk, and other untreated, natural fibers by determining the minimum amount of modified-zeolite-containing synthetic polymers or fibers necessary to impart a desired antibacterial effect. In so doing, the invention provides for a textile article that is more flexible, breathable, or otherwise tactilely comfortable.
In essence, the invention makes it possible to predict the antibacterial activity of a fabric constructed with a mixture of natural and antibacterial fibers and to design the structure of the fabric such as to ensure that it is antibacterial throughout its surface. This produces a fabric that is entirely and substantially uniformly active according to a predetermined degree of efficacy.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 schematically represent modified particles and their respective spheres of antibacterial influence.
FIG. 3 represents a portion of antibacterial fiber with its cylinder of antibacterial fiber influence.
FIG. 4 represents a section of antibacterial thread with its cylinder of thread influence.
FIG. 5 represents a portion of a section of antibacterial fabric according to the invention.
FIG. 6 represents a portion of antibacterial thread in the shape of a partial torus with its cylinder of thread influence.
FIG. 7 shows a cut-away view of FIG. 6 along line A—A.
DETAILED DESCRIPTION OF THE INVENTION
The invention is based on the idea of providing a model for the antibacterial activity of a fiber or cloth containing a modified zeolite component, This model provides a method of predetermining the antibacterial properties of a textile article based upon the concentration of modified zeolite and the physical parameters of the yarn incorporated in it. Accordingly, the invention enables the prediction of the spatial distribution of antibacterial activity of a textile having predetermined physical characteristics. Moreover, the invention provides a procedure for calculating the minimum amount of modified zeolite needed for a textile product to possess a particular level of antimicrobial activity, thus allowing the production of application-sensitive, non-allergenic textile articles.
As used herein, the term yarn is intended to be inclusive of any thread, filament, fiber, polymer or combinations thereof used in woven textiles. The term denier is a unit of fineness equal to the fineness of a yarn weighing one gram for each 9000 meters. As commonly defined in the art, the term warp refers to a series of yarns extending lengthwise in a loom crossed by the woof or weft, the filling yarn of a woven textile article.
In the description that follows, the textiles are described as made with cotton as a complementary fiber to antibacterial polyester yarn of the type described in U.S. Pat. No. 4,775,585. As would be understood by one skilled in the art, antibacterial polyester yarn can by mixed with other natural or synthetic fibers, either exclusively or in combination, provided that they are of nearly the same denier and length in order to create a mechanically acceptable thread or yarn. It is obvious that the antibacterial thread used in the following description can be replaced by an unlimited number of other synthetic textile fibers, such as polyamide or acrylic resins, that may contain modified zeolite.
The method of the present invention allows the predetermination of the amount and quality of antibacterial fibers containing modified zeolite necessary to produce textiles having a specific antibacterial activity. In general, the method follows from a discovery regarding the way the spatial orientation of the modified-zeolite-treated polymer and/or fiber components of a textile article affects its antimicrobial properties. More specifically, the inventors realized that a particle of modified zeolite has an antibacterial effect not only through direct contact with the particle, but also through a zone of influence within the surrounding volume. In other words, a modified zeolite particle can exert an antibacterial effect over a volume of space that is greater than the volume of the particle itself.
To confirm this discovery, an exemplary textile article was constructed and tested as follows. Modified-zeolite powder was added to a polymer before the polymer was used to make textile fibers as described in U.S. Pat. No. 4,775,585, which is incorporated in its entirety herein by this reference. The polymer, in this case a polyester, was then made into fibers about 38-mm long. These polyester fibers contained a mixture of 50 wt % zeolite modified with silver cations and 50 wt % zeolite modified with copper or zinc cations, totaling 0.8 wt % modified zeolite content overall in the article. The polyester fibers were then mixed with cotton fibers of the same length to form a thread which then could be woven. The polyester used was at least equal to 50 wt % of the mixture with cotton, which corresponds to the minimum level of acceptable antibacterial efficacy shown by load tests. These tests demonstrated that polyester fiber loaded with modified zeolite, hereinafter called “antibacterial fiber,” produced an antibacterial effect also on the part of cotton fibers placed close by, even without physical contact.
Based on these findings, the method of the invention was developed to enable the manufacture of woven or non-woven textiles so that the intensity of the antibacterial effect is predetermined based on how modified zeolite is structured within the textile. For example, fabrics can be manufactured such that only parts of the threads composing them contain antibacterial fiber; or non-woven textiles can be manufactured with fibers only parts of which are antibacterial.
Moreover, depending on the application for which the antibacterial textile is intended, it is possible, for example, to produce a bacterio-static effect (halting cell growth) as opposed to a bactericidal effect (destruction of bacteria). In this way, an existing bacterial strain can be preserved or bacterial growth can merely be delayed until the article is removed. This “customization” of a textile article's antimicrobial effect is accomplished by changing the modified zeolite concentration and/or denier of the fibers or polymers used. For example, the modified zeolite concentration in the fabric can be changed by combining the weft thread of a specific denier and constant modified zeolite concentration with a non-zeolite containing warp thread, and by changing the denier of the latter thread to produce the desired result. Consequently, a textile designed according to the method of the invention allows the deduction of its antibacterial properties.
As discussed above, the antibacterial effect of zeolite is due to the presence of silver, copper, or zinc ions (hereinafter “metallic ions”). These metallic ions act directly on bacterial cell walls or indirectly by generating oxygen. Moreover, the volume of antibacterial effect in a given space is in proportion to the density of the above-mentioned metallic ions in the same space. As illustrated in FIG. 1, a modified zeolite particle 1 , which may be a few microns in size, is surrounded by a space in which there is antibacterial efficacy. This space is approximated by a sphere 2 within which the metallic ions can affect microorganisms, i.e., the initial sphere of antibacterial influence.
If a second particle 1 of modified zeolite is placed close to the first modified zeolite particle 1 and at a distance less than the radius of their respective spheres 2 of antibacterial influence, both spheres of influence intersect each other and produce an antibacterial space the size of which is greater than the volumes of each separate sphere 2 . For example, as seen in FIG. 2, if two modified zeolite particles 1 are placed next to one another in such a way that the spheres of antibacterial influence are concentric, tests have shown that the resulting combined sphere 5 of antibacterial influence will have a diameter approximately 40% greater than the two initial spheres of influence.
By extension, if many particles of modified zeolite are integrated uniformly in an antibacterial fiber 6 as shown in FIG. 3, a volume of antibacterial effect, termed the cylinder 7 of fiber influence, is formed, Thus, a volume of antibacterial protection will be provided by the cylinder 7 of fiber influence that is clearly greater than the volume of the antibacterial fiber 6 itself.
As expected, the diameter of the cylinder 7 of fiber influence varies according to the concentration of modified zeolite in the antibacterial fiber 6 . The diameter of the cylinder 7 of fiber influence has not been measured as such, but it has been observed that at least 50% of antibacterial polyester fiber 6 containing 0.8% modified zeolite is needed in a thread in order to obtain a satisfactory antibacterial result, termed “antibacterial effect of reference,” as determined by arbitrary, empirical antibacterial tests based on conventional antibacterial-activity standards. For example, a desired antibacterial effect of reference could be the elimination of a certain percentage (e.g., 99%) of a given bacterium (e.g., Staphylococcus aurus ) after at least one hour of contact with the antibacterial thread.
By further combining multiple fibers into threads, it is understood that the desired effect may be made more intense. As illustrated in FIG. 4, each antibacterial fiber 6 in contact with a cotton fiber 9 of the same length and denier causes an increased cumulative antibacterial effect measured by a cylinder 10 of antimicrobial thread influence. Under these conditions, because of the distribution irregularities of these two types of fiber, it is estimated that the diameter of the cylinder of fiber influence is, at a minimum, 3 to 4 times the diameter of the antibacterial fiber 6 ; thus, a cotton fiber 9 having the same denier and placed in contact with the antibacterial fiber 6 is contained within the cylinder of fiber influence and acquires an induced antibacterial effect throughout its volume. According to one aspect of the invention, this property of the combined thread is utilized to ensure adequate antibacterial activity throughout the entire surface of the resulting textile.
The following empirical formula was developed to calculate the diameter of the cylinder 7 of antimicrobial fiber influence possessed by an antibacterial fiber 6 :
DIf=Df{ 1+2[ Cf /(0.8K)]} ½ ,
where DIf is the diameter of the cylinder 7 of fiber influence; Df is the diameter of the antibacterial fiber 6 ; Cf is the zeolite concentration in percent by weight of modified zeolite in the antibacterial fiber 6 ; and K is a correcting coefficient adjusted by calibration on the basis of laboratory tests.
The value of K is selected to be one when the desired antibacterial effect is equal to the “antibacterial effect of reference,” as defined above; greater than one for a bactericidal antibacterial effect; and less than one if a bacterio-static effect is desired. Thus, the invention can also be used to predict the amount of modified zeolite necessary to produce a desired level of antimicrobial activity.
Woven and non-woven textiles, as well as fabrics, can be used in practicing the invention. Cotton fiber may be entirely or partially substituted with other fibers not having an antibacterial effect as long as their use allows manufacture of a thread having appropriate mechanical characteristics. Thus, referring again to FIG. 4, the cylinder 10 of thread influence in a composite thread 11 that contains an average density of modified zeolite is determined by the modified zeolite density in the antibacterial fibers 6 from which it is made and by the proportion of mixed cotton or other fiber 9 . For example, a mixture of 50 wt % antibacterial fiber 6 containing 0.8 wt % modified zeolite with 50 wt % cotton fiber 9 has a cylinder 10 of thread influence that corresponds to an average modified zeolite concentration of 0.32 wt %, taking into consideration the free spaces 12 between fibers 6 and 9 . These spaces are estimated to result, for example, in an expansion factor (ff) of about 1.25%, which one skilled in the art would recognize to be a realistic and acceptable estimate. If the thread 11 is formed into a yarn containing modified zeolite particles in constant concentration, one can calculate the diameter of the cylinder 10 of thread influence from the diameter of the cylinder 7 of fiber influence of the antibacterial fibers 6 using the following equations:
DIF=DF {( Pf/ 50) ½ +( DIf/Df− 1)[( CF/Cf )( Df/DF )] ½ },
DIf=Df[ 1+2( Cf/ 0.8K) ½ ], and
CF=Cf[Pf /(100 ff )0.8],
where DIF is the diameter of the cylinder 10 of thread influence; DF is the diameter of the composite thread 11 ; Df is the diameter of the fiber 6 containing modified zeolite used as the weft; DIf is the diameter of the cylinder 7 of fiber influence; Cf is the modified zeolite concentration in the antibacterial fiber 6 in weight percent; CF is the average modified zeolite concentration in the thread 11 in weight percent; Pf is the weight percentage of antibacterial fiber 6 in the thread 11 ; and ff is the fiber's expansion factor in the composite thread 11 .
Combining the equations above into a single expression, the following equivalent equation is derived:
DIF/DF =( Pf/ 50) ½ +2[ CfPf /(100 ffK )* Df/DF] ½ .
Thus, to solve for DIF/DF (the diameter of thread influence per thread of a certain diameter), one would first need to determine Df/DF, which is calculated as follows. If one uses warp thread having the metric number of 10, where the metric number 10 is a measure of thread fineness equal to 10 kilometers of thread having a weight of 1 kilogram, then the weight of one kilometer of metric number 10 thread is 100 grams. Assuming the density of this thread is equal to 1, the volume of thread is 100 cm3 and the cross-sectional area (S) of the thread would be
S= 100 cm3/100,000 cm=1×10 −3 cm 2 .
Similarly, if one uses weft fiber having a denier of 1.5, where a denier of 1.5 is a measure of fiber fineness equal to 9 kilometers of fiber having a weight of 1.5 grams, then the weight of 1 km of fiber is 1.5/9=0.17 g/km. Assuming the density of this fiber is equal to 1, the volume of the fiber is 0.17 cm3 and the cross-sectional area (s) of the fiber would be
s= 0.17 cm3/100,000 cm=1.7×10 6 cm 2 .
Since the areas of the thread and fiber above are equal to πr 2 ,
S =( DF/ 2) 2 *3.14 and s =( Df/ 2) 2 *3.14.
Rearranging, s/S=(Df/DP) 2 and Df/DF=(s/S) ½ . Thus,
Df/DF= 1.7×10 −6 /1×10 −3 =(0.0017) ½ =0.041.
Thus, to determine diameter of thread influence (DIF) for a given diameter of thread (DF) containing 65 wt % antibacterial fiber (Pf=65) and 0.8 wt % modified zeolite (Cf=0.8), fiber of 1.5 denier, metric number 10 thread, fiber and thread densities approximately equal to 1, an expansion factor (ff) of 1.25, and Df/DF=0.04 as just calculated:
DIF/DF =(65/50) ½ +2[(0.8)65/(100)(1.25)*0.04] ½ =1.5,
i.e., the calculated diameter of the cylinder of thread influence (DIF) is 1.5 times the diameter of the thread used.
Turning to FIG. 5, an example is given of a warp thread 14 not containing modified zeolite and associated with a weft thread 13 containing modified zeolite. As described, the weft thread 13 creates a sinusoidal cylinder 15 of antimicrobial thread influence that wraps around the warp thread 14 , as illustrated in the figure. Consequently, having a weft thread 13 with a known DIF, as calculated with the formula given above, it is possible to estimate the maximum diameter of the warp thread allowable in order to ensure that it is contained within the cylinder of antimicrobial influence of the weft thread, such that the resulting woven fabric is entirely antibacterial. As determined by the geometry of the composite fabric, it is apparent that the theoretical maximum diameter of the warp thread 14 must be between ½(DIF−DF) and (DIF−DF), depending on how tightly woven the warp and weft fibers are.
For example, if one takes a weft thread 13 with a DIF equal to 1.4 DF, the warp thread 14 will be entirely antibacterial if it is tightly woven and its diameter is less than or equal to 0.4 DF. Conversely, if one desires to use a warp thread with a diameter equal to 0.25 DF, one must use a weft thread with a DIF equal to 1.25 DF. If a larger warp thread is desired, it is possible to change the modified zeolite concentration CP in the antibacterial fiber used and/or the antibacterial fiber percentage Pf in the warp thread 13 to produce the equivalent desired result. For example, if a warp thread with a diameter equal to 0.37 DF is used, the calculation based on the above equations, with K=1, indicates that a solution would be to change the percentage of antibacterial fibers to Pf=52%.
The antibacterial weft thread 16 as depicted in FIGS. 6 and 7 shows a shape resembling a torus section with a concave zone 17 and a convex zone 18 . In the convex zone 18 , a dilution of the metallic ions was discovered, whereas an increase in concentration of metallic ions was seen in the concave zone 17 . Thus, the modified thread's volume 19 of influence is no longer concentric with respect to the weft thread 16 , but shifts towards the inside of the torus section. Consequently, there is a relatively thick antibacterial zone inside the torus, which protects the warp's thread even better.
In the case of manufacture of non-woven fabric, different types of fibers are mixed with a binding agent, usually a thermoplastic binding material. This mixture is spread in even layers (approximately 100 to 500 grams per square meter) and then compressed and heated to a suitable temperature to allow the fusion of the binding thermoplastic material, thereby ensuring that the fibers hold together and form a non-woven textile sheet. Contrary to woven textiles, the fibers of non-woven textiles are not laid on each other; thus, a much larger expansion factor (FF) of about 12 is normal because the fibers fill only about one-twelfth of the sheet volume. Therefore, an expansion factor FF=12 is used in the following example, although other values are possible.
To create a non-woven antibacterial textile, antibacterial polyester fibers and associated materials are selected according to the desired level of antimicrobial efficacy and other application properties. For example, if one wished to produce a non-woven textile capable of absorbing water for use in cleaning wet surfaces, the fibers would be viscose and the binding thermoplastic material preferably polypropylene. The polypropylene (represented in the equation below by the quantity PP) would be about 15% of the total weight of the sheet. (The space that the sheet occupies is not taken into consideration in the expansion factor because this quantity only relates to the expansion due to the fibers.)
Thus, in the following examples, PP is set at 15 (but other values may apply), based on the assumption that 85 wt % of the non-woven textile sheet weight consists of fiber with FF=12. In order to obtain an antibacterial effect, the antibacterial fibers are introduced spread uniformly and in sufficient quantity for the total sheet volume to be filled by the volumes of the cylinders of fiber influence. The volume of fiber influence (VIf) of a cylinder of fiber influence in such case is expressed as:
VIf =( DIf/ 2) 2 3.14 L,
where L represents the length of the fiber and DIf=Df[1+2(Cf/0.8K)] ½ , as defined above.
From a simple geometry, the volume of an antibacterial fiber, designated as “fiber volume” (Vf), is approximately equal to Vf=(Df/2) 2 3.14 L. Thus, the difference between the volume of fiber influence and the fiber volume, (VIf−Vf)=[(DIf/2) 2 −Df/2]3.14 L, is the volume that can be safely filled, assuming a given expansion factor, by the fibers that do not have an antibacterial effect. The cumulative volume of fibers (VF) located in the fiber influence volume (VIf), which has to be taken into consideration when calculating the respective percentages of antibacterial and non-antibacterial fibers, can be calculated as follows:
VF=Vf +( VIf−Vf )/ FF,
where, for an FF value of 12, one obtains VF=(VIf+11 Vf)/12.
For an average fiber density of one, the reasoning used at the fiber level is also representative of an antibacterial non-woven textile composition, and the results obtained are directly applicable to the whole of the non-woven textile because its composition remains homogenous. One can thus determine the percentage (PF) of antibacterial fibers in the non-woven textile that produces a desired antibacterial effect in the non-woven textile as follows:
PF =( Vf/VF )(100 −PP ),
where PP represents the weight percentage of binding thermoplastic material.
For example, if one uses polyester fiber with the specific previous reference content of 0.8 wt % modified-zeolite with a DIf value equal to 3 Df, and if FF=12 and PP=15, a value of PF=51 wt % is obtained (this DIf corresponding to a composition of 51 wt % antibacterial fibers, 15 wt % thermoplastic binding material, and 34 wt % non-antibacterial fibers).
During the weaving process, yarns containing modified zeolite are typically used for weaving of the warp. Compared to the weft, the warp yarn is usually of a much lower denier. In other words, warp containing modified zeolite is much coarser than the weft with which it is woven. Thus, another advantage of the invention is that it allows the manufacture of thin and supple sheets of compact, non-woven fibers (“non-woven textile”) as well as more tactilely comfortable woven textile articles.
The process of the invention enables the manufacture of textiles with durable antibacterial efficacy in applications previously deemed unsuitable for the antibacterial fibers developed in the prior art. For example, a mixture of the polyester fiber described above with conventional cotton fiber produced bed sheet material that retained over 80% of its antibacterial activity after 100 wash cycles, which is longer than the normal life of such products.
As would be understood by those skilled in the art, any number of functional equivalents may exist in lieu of the preferred embodiments described above. Thus, as will be apparent to those skilled in the art, changes in the details, steps and materials that have been described may be made within the principles and scope of the invention illustrated herein and defined in the appended claims. Therefore, while the present invention has been shown and described in what is believed to be the most practical and preferred embodiment, it is recognized that departures can be made therefrom within the scope of the invention, which is therefore not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent products and methods. | Empirically determined models allow the predetermination of the accurate amount and quality of modified zeolite required to produce textile articles having a specific degree of antibacterial activity in accordance with the requirements for particular applications. Equations accurately predict the relationship between the amount and spatial orientation of modified-zeolite-containing polymers or fibers and the desired degree of antibacterial activity. | 3 |
CROSS-REFERENCE
This application is a continuation-in-part of U.S. patent application Ser. No. 07/612,222 filed in the U.S. Patent & Trademark Office on Nov. 9, 1990 now abandoned.
TECHNICAL FIELD
The present invention relates to the manufacture of clothing from dyed cellulose fabrics. More particularly, the present invention relates to a composition, bleaching agent, bleaching element and method for inhibiting the yellowing known to occur when manufacturing intentionally distressed, dyed cellulose fabrics.
BACKGROUND OF THE INVENTION
Clothing made from cellulose fabrics such as cotton is well known. For example, a denim fabric has been used for many years to manufacture work clothes such as jeans. Such clothing was produced with a starch based sizing that eased the manufacturing and handling processes, but resulted in a stiff relatively uncomfortable garment. Also, the fabric had been dyed with a dark blue indigo that, when washed, bled from the fabric. Thus, after a substantial period of wear and washing, the denim fabric lightened in color and the garment became more pliable and comfortable. In addition, the fabric took on a used or distressed appearance, particularly on the seams, panels and raised areas where the stitching had been made.
In time, and particularly recently, denim clothing has become more popular. Denim fabrics are being utilized not only to make work clothes, but for jackets, coats, shirts and a seemingly endless variety of other garments. The used or distressed look has likewise become fashionable. As a result, manufacturers of denim clothing have developed methods by which to distress denim fabric. One method employed to distress a denim fabric is known as "acid washing." This method typically consists of abrading the denim fabric through the use of pumice stones or some other abrading device such as silica sand to produce a softer, more pliable fabric with random, localized areas of lighter color.
Described more particularly, acid washing of a denim garment has been accomplished by the following steps. A quantity of garments are first washed in a solution to remove the starch-based sizing. The garments are then dry tumbled in a quantity of pumice rock or silica sand that has been impregnated with an oxidizer solution, usually potassium permanganate. After tumbling, the garments are washed in a neutralizing solution to remove any excess oxidizer. The garments are then dried in a conventional manner.
Other methods of distressing denim or other fabrics are known. For example, U.S. Pat. No. 4,740,213, issued on Apr. 26, 1988 to Francesco Ricci, discloses a method of producing a random faded effect on cloth or made-up garments, and the endproduct obtained by implementation of such a method. The method described in this patent comprises the steps of bleaching the cloth in a dry state, utilizing granules of pumice or similar materials impregnated with a fluid having powerful bleaching properties, tumbling the granules and cloth together in a rotating drum such that close contact is brought about between the two, recovering the granules following rotation of the drum for a set duration, and neutralizing any residual bleaching agent held in the cloth by washing and drying.
Another method of distressing fabrics is disclosed in U.S. Pat. No. 4,850,156, issued on Jul. 25, 1989 to David L. Bellaire. This patent discloses a method of preparing porous abrasive rock for use in distressing fabric including the steps of impregnating rocks placed in a vacuum vessel with a bleaching solution under reduced pressure, maintaining the reduced pressure for a first interval while injecting the solution beneath the rocks, and then increasing the vessel pressure above ambient for a second interval prior to removal and use of the rocks to abrade fabric.
These method have provided a distressed appearance to the denim fabric suitable for the many types of denim garments. However, it has been observed that the acid-washed denim fabric is susceptible to yellowing when exposed to ultraviolet light, such as sunlight. Such latent yellowing of the fabric is undesirable. Further, the intensity of the yellowing increases with the duration of the fabric's exposure to ultraviolet light. In some instances, the yellowing can be so severe that the finished garment is rendered unsaleable. It is not unusual for otherwise acceptable denim garments to yellow sufficiently to render the garments unsaleable. Thus, manufacturers of acid washed or distressed denim clothing seek to inhibit, if not eliminate, yellowing of the denim fabric.
Yellowing of the denim fabric is believed to result from the presence of anthranilic acid on or in the garment. The anthranilic acid is believed to be produced during the acid washing process. As noted above, denim fabric is conventionally treated with the well-known dye indigo. While naturally available, indigo dye can be and is synthesized for industrial use. Synthesized indigo dye is usually a blue powdery material with a copper luster. The principal coloring matter of indigo dye has a chemical formula of C 16 H 10 O 2 N 2 . During the acid washing process, the indigo dye oxidizes to produce isatin, a crystalline compound or indole that has oxygen molecules at carbon positions "2" and "3". Isatin is commonly orange to red in color, water soluble and has a chemical formula of C 6 H 5 NO 1 .
As also noted above, at least one method of preparing pumice stones for use in the acid washing process is to soak or otherwise impregnate the stones with a bleaching agent such as potassium permanganate, KM n O 4 . An excess amount of potassium permanganate is usually present in the acid wash process. It is believed that this excess of potassium permanganate facilitates further oxidation of the isatin, resulting in the formation of anthranilic acid. Anthranilic acid is a white to pale powder and water soluble. It is known that, in time, anthranilic acid discolors to a yellow color. The chemical reaction whereby the anthranilic acid becomes discolored is not known to the inventor. However, the inventor is aware of the fact that such discoloring occurs. It is believed by the inventor that the presence of anthranilic acid on or within the distressed denim material is a, if not the, primary cause of the latent yellowing which occurs when acid-washed denim garments are exposed to ultraviolet light.
There is a need in the art, therefore, for a composition and method by which to inhibit the yellowing of denim fabric. This need has been recognized previously. Various chemicals have been used to attempt to combat this problem including ultraviolet and ozone inhibitors. For example, different methods and chemicals have been used to try to neutralize the bleaching agent in an effort to inhibit yellowing. Some of these attempts have included treating the acid-washed denim fabric with bi-sulfates. These methods, however, are expensive and have met with limited success. The need for a cost effective method and composition for inhibiting the yellowing of distressed denim fabric thus remains.
SUMMARY OF THE INVENTION
The present invention fulfills the above-described need in the prior art by providing a composition, a bleaching element, a method of making a bleaching element for distressing fabric and a method for distressing fabric whereby the tendency of acid-washed fabric to yellow is eliminated or substantially reduced. In specific, the present invention solves the problem of latent yellowing of finished, distressed denim garments experienced by manufacturers of such clothing.
Briefly described, the composition of the present invention comprises an acid and an oxidizer in solution that acts to inhibit yellowing of the denim fabric. In one preferred embodiment, the composition of the present invention comprises a solution of about 1 to 25% by weight of potassium permanganate as an oxidizer and about 0.5 to 50% by weight of phosphoric acid as an acid.
The bleaching element of the present invention includes the foregoing described composition. Described somewhat more particularly, the preferred bleaching element of the present invention is an abrading device such as pumice stone or silica sand impregnated with the foregoing described composition.
The method of the present invention for making a bleaching element for distressing fabric includes the step of impregnating an abrading device such as pumice stone or silica sand with the foregoing composition. Described somewhat more particularly, a preferred method of the present invention includes the step of impregnating an abrading device such as pumice stone with a composition in solution comprising an acid and an oxidizer. A preferred oxidizer is potassium permanganate. A preferred acid is phosphoric acid.
The method of the present invention for distressing fabric includes the step of tumbling fabric to be distressed in a tumbler with a plurality of bleaching elements made in accordance with the present invention. The bleaching elements abrade and bleach the fabric during the tumbling process, thereby distressing the fabric and producing the "acid-washed" appearance. It is believed that the composition of the present invention also acts to retard substantially or to stop entirely the oxidation process that results in the formation of anthranilic acid during a conventional acid-washing process. In this manner, it is believed that the present invention eliminates or greatly reduces the latent yellowing of the finished garment upon exposure to ultraviolet light.
Thus, it is an object of the present invention to provide an improved method for distressing fabric.
It is another object of the present invention to provide an improved bleaching element for use in distressing fabric.
It is a further object of the present invention to provide an improved method for making a bleaching element for use in distressing fabric.
It is a further object of the present invention to provide a composition for use in distressing fabric that eliminates or greatly reduces the yellowing of acid-washed fabrics.
It is a further object of the present invention to provide a method for distressing fabric that eliminates or greatly reduces the yellowing of acid-washed fabrics.
It is a further object of the present invention to provide a bleaching element for use in distressing fabric that eliminates or greatly reduces the yellowing of acid-washed fabrics.
It is a further object of the present invention to provide a method, bleaching element and composition to distress fabrics that increases the quantity of saleable end product by eliminating or greatly reducing the yellowing of acid-washed fabrics.
It is still a further object of the present invention to provide a method for distressing fabric that eliminates or greatly reduces yellowing of the fabric in an economical and efficient fashion.
These and other objects, features and advantages of the present invention will become apparent by a reading of the following detailed description in conjunction with the appended claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention includes a composition to be used in distressing fabric, particularly denim cloth, a bleaching element which includes this composition, a method of making such a bleaching element, a method of distressing fabric with this bleaching element, and a garment distressed with this bleaching element. The composition and bleaching element of the present invention are suited for use in a tumbling machine wherein fabric, typically denim cloth, is abraded and bleached to give the fabric a distressed or used appearance. In a preferred embodiment, the composition and bleaching element of the present invention are suited for acid-washing denim garments.
A composition made in accordance with the present invention includes a bleaching agent. A bleaching agent is a material that lightens or whitens a substrate through chemical action. Chlorine related compounds are well known bleaching agents. At least two classes of chlorine related compounds can be used as bleaching agents; including chlorine, hypochlorites and chlorite. Manganese compounds may also be used as a bleaching agent; for example, potassium permanganate and sodium permanganate. Permanganates are a purple salt of permanganic acid and typically used as oxidizing agents and disinfectant. Potassium permanganate has been found to be a preferred bleaching agent for use in the composition of the present invention. Potassium permanganate is a highly oxidative agent and is water soluble.
A composition made in accordance with the present invention also includes an acid. As defined herein, the acid is any compound that will lower the pH of an aqueous solution. The acid compound can be organic or inorganic. Suitable acids that can be used in the present invention include, but are not limited to, inorganic acids such as hydrochloric acid, sulfuric acid and phosphoric acid. A tribasic acid, more particularly phosphoric acid, has been found to be well suited for the preferred composition. Phosphoric acid is conventionally provided in liquid or solid form and has a chemical formula H 3 PO 4 . For example, pure phosphoric acid is a white crystalline, water soluble solid. The inventor know of no reason why other inorganic acids could not be utilized within the scope of the present invention. It is thus to be understood that a preferred composition of the present invention is provided as an aqueous solution.
The bleaching element of the present invention can be made by impregnating an abrading device with the composition of the invention. Those of ordinary skill in the art will appreciate that the abrading device is thus susceptible to impregnation by the composition. Suitable abrading devices include pumice stone and silica sand. Other suitable abrading devices include diatamateous earth and di-calcium phosphate or various binders of mineral aggregates. Such abrading devices are known in the art but, as detailed below, have not been treated with the composition of the present invention.
The bleaching element of the present invention is preferably made by impregnating the abrading device with the composition of the present invention. Such impregnation may be accomplished in any suitable manner, including by soaking the abrading device in a solution of a predetermined amount of an acid such as phosphoric acid, an oxidizer such as potassium permanganate, and water. For example, a predetermined quantity of pumice stone may be introduced into the solution and permitted to soak in the solution for a time sufficient to impregnate the stone. At the expiration of such a time, the stone is withdrawn from the solution and dried. The stones are then ready for use in the distressing process of the present invention.
To treat fabric or a garment with the bleaching element of the present invention, the bleaching elements may be made in accordance with the above-described method. A method of distressing fabric in accordance with the present invention includes abrading fabric with such bleaching elements. A quantity of these bleaching elements are loaded into a tumbling machine containing the fabric or garments to be treated. The fabric or garments are tumbled in the tumbler with the bleaching elements to give the fabric or garments the desired acid-washed appearance and feel. Once the tumbling action is concluded, the fabric or garments are removed from the tumbler and "derocked," meaning that any particulate matter contained on or in the material is removed. The garments are then rinsed in a neutralizing solution. The rinse may, but need not, include a neutralizing agent such as a bisulfate compound. The fabric or garments are then dried and may be further processed for retail sales.
Those skilled in the art will appreciate that the fabric or garment has been abraded or "acid-washed" in order to obtain a fashionable and comfortable garment. Moreover, it has been discovered by the inventor that fabric and garments that have been treated in this manner do not yellow when exposed to sunlight. The following example is provided to yet further describe the present invention and to disclose the best mode contemplated by the inventor of carrying out the invention.
EXAMPLE I
Two sets of bleaching elements were made, one control group and one test group made in accordance with the present invention.
Control Group
The control group was made as follows. A one hundred (100) gallon tank was filled with approximately fifty (50) gallons of water. The temperature of the water was approximately 120° Fahrenheit. Eighteen pounds (18 lbs.) of crystalline potassium permanganate was added to the water in the tank. The solution was well mixed, by motor-driven propeller, for a period of ten (10) minutes. Approximately fifty pounds (50 lbs.) of pumice stone was then placed into the solution. The pumice stone was left in the solution for a period of approximately thirty (30) minutes. The pumice stone was then removed from the solution and allowed to air dry under ambient conditions for approximately twenty (20) minutes.
Test Group
The test group was made in accordance with the present invention as follows. A one hundred (100) gallon tank was filled with approximately fifty (50) gallons of water. The temperature of the water was approximately 120° Fahrenheit. Eighteen pounds (18 lbs.) of crystalline potassium permanganate was added to the water in the tank. In addition, one (1) gallon of 75% by weight phosphoric acid was added to the water. This solution was well mixed, by a motor-driven propeller, for a period of ten (10) minutes. Approximately fifty pounds (50 lbs.) of pumice stone was then placed in the solution. The pumice stone was left in the solution for a period of approximately thirty (30) minutes. The pumice stone was then removed from the solution and allowed to air dry under ambient conditions for approximately twenty (20) minutes.
Twenty pairs of new, blue indigo dyed jeans made of a denim fabric were placed into a two hundred and fifty pound (250 lb.) capacity Milnor "open pocket" washing machine. The washing machine was filled with approximately eighty (80) gallons of water. The temperature of the water was approximately 145° Fahrenheit. A quantity of approximately twenty-four ounces (24 oz.) of alpha amalyze enzyme was added to the water in the washing machine. The jeans were washed (or desized) in this solution for a period of approximately fifteen (15) minutes. At the conclusion of this time period, the solution was drained from the washing machine.
The washing machine was then refilled with eighty (80) gallons of clean water. The temperature of the water was approximately 110° Fahrenheit. The jeans were rinsed in this water through activation of the washing machine for a period of approximately five (5) minutes. At the conclusion of this time period, the water was drained from the washing machine. The jeans were then spun in the washing machine to remove excess water. The jeans were then removed from the washing machine and drained in a conventional dryer. This completed the "pre-washing" process for all twenty (20) pairs of jeans.
Ten pairs of the pre-washed jeans were placed in a Troy "belly washer" tumbling machine having a perforated drum. The control group bleaching elements, comprising approximately fifty pounds (50 lbs.) of pumice stone soaked in solution including potassium permanganate, were placed in the tumbling machine. The jeans were tumbled in the tumbling machine for a period of approximately twenty (20) minutes. At the conclusion of this time period, the jeans were removed from the tumbling machine. The jeans were then derocked. The jeans were then placed in a two hundred and fifty pound (250 lb.) washing machine. The washing machine was filled with approximately eighty (80) gallons of water. The temperature of the water was approximately 140° Fahrenheit. A quantity of a neutralizing agent, namely, five pounds (5 lbs.) of hydroxalamine sulphate was added to the water. (It is to be understood that a bisulfate or an acetic and peroxide mixture could also be used as a neutralizing agent.) The jeans were washed in this solution for a period of approximately eighteen (18) minutes. At the conclusion of this time period, the solution was drained from the washing machine.
The washing machine was then refilled with eighty (80) gallons of clean water. The temperature of the water was approximately 120° Fahrenheit. The jeans were rinsed in this water through activation of the washing machine for a period of approximately five (5) minutes. The jeans were then spun in the washing machine to remove excess water. The jeans were then removed from the washing machine and dried in a conventional dryer. This completed the "acid washing" process for these ten (10) pairs of jeans.
The remaining ten (10) pairs of the pre-washed jeans were likewise placed in a Troy "belly washer" tumbling machine having a perforated drum. This tumbling machine was not the same as that used previously. This time, however, the test group bleaching elements, made in accordance with the present invention and comprising fifty pounds (50 lbs.) of pumice stone soaked in solution including potassium permanganate and phosphoric acid, were placed in the tumbling machine. The jeans were tumbled in the tumbling machine for a period of approximately twenty (20) minutes. At the conclusion of this time period, the jeans were removed from the tumbling machine. The jeans were then derocked. The jeans were then placed in a two hundred and fifty pound (250 lb.) Milnor washing machine. The washing machine was filled with approximately eighty (80) gallons of water. The temperature of the water was approximately 140° Fahrenheit. A quantity of a neutralizing agent, namely, five pounds (5 lbs.) of hydroxalamine sulphate was added to the water. The jeans were washed in this solution for a period of approximately eighteen (18) minutes. At the conclusion of this time period, the solution was drained from the washing machine.
The washing machine was then refilled with eighty (80) gallons of clean water. The temperature of the water was approximately 120° Fahrenheit. The jeans were rinsed in this water through activation of the washing machine for a period of approximately five (5) minutes. The jeans were then spun in the washing machine to remove excess water. The jeans were then removed from the washing machine and dried in a conventional dryer. This completed the "acid washing" process for these jeans.
Five (5) pairs of jeans treated with the control group bleaching elements and five (5) pairs of jeans treated with the test group bleaching elements were placed in direct sunlight for a period of approximately ten (10) hours. At the conclusion of this time period, a visual examination of all ten (10) pairs of jeans was conducted. It was found that the five (5) pairs of jeans tumbled in with the control group bleaching elements had yellowed greatly, but the five (5) pairs of jeans tumbled with the test group bleaching elements had retained this original blue color and had not yellowed.
Similarly, the remaining five (5) pairs of jeans treated with the control group bleaching elements and the remaining five (5) pairs of jeans treated with the test group bleaching elements were placed in ultraviolet light cabinets for a period of approximately four (4) hours. It is to be understood that these remaining ten (10) pairs of jeans were subjected to direct ultraviolet light. At the conclusion of this time period, a visual examination of all ten (10) pairs of jeans was conducted. It was found that, as with the pairs of jeans exposed to direct sunlight, the five (5) pairs of jeans tumbled with the control group bleaching elements had yellowed greatly, but the five (5) pairs of jeans tumbled with the test group bleaching elements had retained their original blue color and had not yellowed.
The foregoing description and examples of the preferred embodiments of the present invention are given by way of illustration. In light thereof, those of ordinary skill in the art will appreciate that various modifications made are made without departing from the spirit and scope of the present invention. | A composition, bleaching agent, bleaching element, method for making a bleaching element and a method for intentionally distressing fabric, typically blue indigo denim cloth. The disclosed composition includes a mixture of an oxidizer and an acid that eliminates or substantially reduces yellowing of the fabric after acid washing. The preferred oxidizer is preferably selected from the group consisting of potassium permanganate, sodium permanganate and sodium hypochlorite. The preferred acid is an acid such as phosphoric acid. A bleaching element made in accordance with the present invention includes an abrading device impregnated with the composition of the present invention. The method for intentionally distressing fabric such as denim includes the step of tumbling or otherwise subjecting the fabric to a bleaching element made in accordance with the invention. The disclosed invention further includes a finished garment treated by the disclosed method for intentionally distressing fabric. | 3 |
STATEMENT AS TO FEDERALLY SPONSORED RESEARCH
This invention was supported in part by U.S. Public Health Service Grants DK41513, GM46577, DK39773, DK38452 and NS10828, and an award from the NIDDK. The government may have certain rights in the invention.
This application is a continuation in part of provisional application U.S. Ser. No. 60/016,774, filed May 7, 1996.
This application is a continuation in part of provisional application U.S. Ser. No. 60/016,774, filed May 7, 1996.
BACKGROUND OF THE INVENTION
The invention relates to protein kinases and methods of activating or inhibiting the expression of protein kinases.
Mitogen-activated protein kinase (MAPK) cascades have been remarkably conserved in evolution. The core of these cascades is a three-tiered module of serine/threonine kinases that consists of a MAPK-extracellular signal regulated kinase kinase (a MEKK), a MEK, and a MAPK or extracellular signal regulated kinase (ERK). In simple eukaryotes, such as the budding yeast Saccharomyces cerevisiae (S. cerevisiae), and the fission yeast, Saccharomyces pombe (S. pombe), these cascades are activated predominantly by cellular stresses such as nutritional starvation and osmolar stress (reviewed in Elion, TIBS 5:322 (1995); Herskowitz, Cell 80:187 (1995); and Levin et al., Cell Biol. 7:197 (1995)). In mammals, these cascades have evolved to allow responses to complex stimuli (e.g., growth factors and inflammatory cytokines), but in many cases, such as the response to osmolar challenge (Galcheva-Gargova et al., Science 265:806 (1994); Han et al., Science 265:808 (1994)), the primitive stress responses remain intact.
Epistasis analyses in yeast suggest that the Sterile 20 (Ste20) protein serine/threonine kinases and related protein kinases act upstream of the three tiered module. Three mammalian homologs of Ste20 have been reported to date: p21-activated protein kinase (PAK1) and related PAKs (Manser et al., Nature 367:40 (1994); Martin et al., EMBO J. 14:1970 (1995)); germinal center (GC) kinase (Katz et al., J. Biol. Chem. 269:16802 (1994)); and mammalian Ste20-like kinase 1 (MST1) (Creasy et al., J. Biol. Chem. 270:21695 (1995)). Mammalian Ste20s may function upstream of MEKK/MEK/MAP kinase pathways. PAK1 (Manser et al., Nature 367:40 (1994)) and GC kinase (Katz et al., J. Biol. Chem. 269:16802 (1994)) have been shown to be capable of activating mammalian MAPK kinases (Polverino et al., J. Biol. Chem. 270:26067 (1995); Pombo et al., Nature 377:750 (1995); Zhang et al., J. Biol. Chem. 270:12665 (1995)), further illustrating remarkable evolutionary conservation of the MAPK kinases. When co-transfected with MAP kinase, both PAK1 and GC kinase activate the stress-activated protein kinase (SAPK)/c-Jun amino terminal kinase (JNK) cascade. PAK1 also activates the stress activated MAPK, p38, as well.
Ste20 protein kinases can be divided into two families based on their structure and regulation. The first family is the Ste20 family, which includes Ste20, PAK1 and related PAKs. These proteins contain a carboxy terminal catalytic domain and an amino terminal regulatory domain which has a p21 cdc42/rac1 binding region (Manser et al., Nature 367:40 (1994); Martin et al., EMBO J. 14:1970 (1995)). PAK1 appears to be activated by binding to cdc42Hs or Rac1. Following binding to the small GTP-binding proteins, the kinase undergoes autophosphorylation and is activated. Physiologic activators of PAK1 have been identified, and include the chemoattractant peptide fMetLeuPhe, and Interleukin 1 (IL-1) (Zhang et al., J. Biol. Chem. 270:12665 (1995)).
The second family of Ste20s is the Sps1 family. Members of this group include Sps1, which is encoded by the S. cerevisiae Sporulation specific 1 gene, which is necessary for spore formation in response to nutritional starvation; and the mammalian genes MST1 and GC kinase. The catalytic domain is amino terminal in these proteins, and the function of their carboxy terminal regions has not previously been known. These kinases do not contain an identifiable Rac/cdc42Hs binding domain in their non-catalytic regions. The regulation of this family of Ste20s is not well characterized. MST1 appears to be activated by dephosphorylation. Sps1 and its MAPK, Smk1 (Krisak et al., Genes & Development 8:2151 (1994)), are transcriptionally regulated, being expressed only at certain stages of the sporulation process, but it is not known if there are other modes of regulation of Sps1. Physiological activators of the Sps1 family of Ste20s have not been previously identified.
SUMMARY OF THE INVENTION
The invention is based on the discovery of a novel mammalian protein kinase, SOK-1, that belongs to the Sps1 family of Ste20 homologs. SOK-1 (Ste20 oxidant stress response kinase 1) is a protein kinase which is activated by oxidant stress (e.g., 0.5 mM H 2 O 2 ).
Accordingly, the invention features an isolated nucleic acid encoding a SOK polypeptide, particularly SOK-1. The naturally occurring SOK polypeptide can be from a mammal, such as a human, non human primate, e.g., baboons, monkeys and chimpanzees, goats, pigs, micro-pigs, guinea pigs, rabbits, rats and mice. This nucleic acid encodes an amino acid sequence with at least 50% (preferably at least 60%, more preferably at least 70%, more preferably at least 85%) identity to the amino acid sequence set forth in FIG. 1 (SEQ ID NO:2). The invention also features a substantially pure preparation of a SOK polypeptide. The SOK polypeptide preferably has an amino acid sequence with at least 50% sequence identity to the sequence set forth as SEQ ID NO:2. Preferably, the sequence has at least 60%, 70% or 85% sequence identity to the sequence set forth as SEQ ID NO:2. By "SOK polypeptide" is meant all or part of a novel protein kinase, expression of which is activated by oxidant stress.
By "isolated" is meant that the DNA is free of the coding sequences of those genes that, in the naturally-occurring genome of the organism (if any) from which the DNA of the invention is derived, immediately flank the gene encoding the DNA of the invention. The isolated DNA may be single-stranded or double-stranded, and may be genomic DNA, cDNA, recombinant hybrid DNA, or synthetic DNA. It may be identical to a naturally-occurring DNA sequence, or may differ from such sequence by the deletion, addition, or substitution of one or more nucleotides. The DNAs of the invention therefore include, e.g., a recombinant nucleic acid incorporated into a vector, such as an autonomously replicating plasmid or virus; a cDNA or genomic DNA fragment produced by polymerase chain reaction (PCR) or restriction endonuclease treatment; and recombinant DNA which is part of a hybrid gene encoding additional polypeptide sequences.
Also included in the isolated DNAs of the invention are single-stranded DNAs which are generally at least 10 nucleotides long, preferably at least 18 nucleotides long, more preferably at least 30 nucleotides long, and ranging up to full length of the DNAs encoding a SOK polypeptide.
The single stranded DNAs can also be complementary to a SOK coding strand, so that they can be labelled and used as hybridization probes. Preferably the isolated DNA or its complement hybridizes under stringent conditions to all or part of the nucleotide sequence shown in FIG. 1 (SEQ ID NO:2). "Stringent conditions" include, for example, hybridization at 68° C. in 5×SSC/5×Denhardt's solution/1.0% SDS, or in 0.5M NaHPO4 (pH 7.2)/1 mM EDTA/7% SDS, or in 50% formamide/0.25M NaHPO4 (pH 7.2)/0.25M NaCl/1 mM EDTA/7% SDS; and washing in 0.2×SSC/0.1% SDS at room temperature or at 42° C., or in 0.1×SSC/0.1% SDS at 68° C., or in 40 mM NaHPO4 (pH 7.2)/1 mM EDTA/5% SDS at 50° C., or in 40 mM NaHPO4 (pH 7.2) 1 mM EDTA/1% SDS at 50° C. Moderately stringent conditions including washing in 3×SSC at 42° C. The parameters of salt concentration and temperature can be varied to achieve the desired level of identity between the probe and the target DNA. For guidance regarding such conditions see, e.g., Sambrook et al., Molecular Cloning, A Laboratory Manual, Cold Spring Harbor Press, Cold Spring Harbor, N.Y.; and Ausubel et al., Current Protocols in Molecular Biology, John Wiley & Sons, 1995.
DNAs of the invention can be incorporated into a vector, which may be provided as a purified preparation. DNA, either by itself, or incorporated into a vector, can be incorporated into a cell, and the cell can be propagated to form an essentially homogenous population of cells (e.g., prokaryotic cells, or eukaryotic cells such as mammalian cells)containing SOK, by methods that are well known to those skilled in the art. An "essentially homogenous" population of cells is one in which at least 99% of the cells contain the vector or the isolated DNA of the invention.
A further aspect of the invention is a method of determining whether a candidate compound modulates the expression or activity of SOK. The method includes the steps of:
a) providing a first and a second recombinant cell expressing a SOK gene;
b) introducing a candidate compound into the first recombinant cell, but not into the second cell;
c) measuring a SOK function in the first and second cells;
d) comparing the results obtained with the first and second SOK-transformed cells, wherein an increase or decrease in the SOK function in the first cell compared to the second cell is an indication that the candidate compound modulates SOK expression or activity.
In one embodiment of this method, the SOK function to be measured is activation of the gene encoding the transcription factor NFκB. In another embodiment, the function to be measured is protein kinase activity. In other embodiments, the function is arrest of the cell cycle or activation of SOK by H 2 O 2 .
The invention also features a therapeutic composition that includes a SOK polypeptide or DNA as an active ingredient. Such therapeutic compositions can be formulated with a pharmaceutically acceptable carrier. In another aspect, the invention is a method of administering a therapeutically effective amount of a composition of a SOK polypeptide or DNA, or a fragment thereof, to a mammal, to treat a condition characterized by a proliferative response, e.g., to treat a vessel that has sustained balloon angioplasty-induced injury. A "therapeutically effective" amount is an amount that produces a medically desirable result in a patient.
A method of producing a SOK polypeptide is also included in the invention. In this method, cells containing an isolated DNA encoding a SOK polypeptide are cultured under conditions permitting the expression of the SOK polypeptide, and the SOK polypeptide is isolated. Also included in the invention are therapeutic compositions that include DNAs encoding a SOK polypeptide.
In another aspect, the invention is a substantially pure antibody which specifically binds SOK. An antibody that "specifically binds" to SOK binds to SOK and does not substantially recognize and bind to other antigenically-unrelated molecules. Antibodies according to the invention can be prepared by a variety of methods. For example, a SOK protein or antigenic fragment thereof can be administered to an animal in order to induce the production of polyclonal antibodies. Alternatively, the antibodies can be monoclonal antibodies. Such monoclonal antibodies can be prepared using hybridoma technology (see, e.g., Kohler et al., Nature 256:495 (1975); Kohler et al., Eur. J. Immunol. 6:292 (1976); Kohler et al., Eur. J. Immunol. 6:511 (1976); Hammerling et al., In Monoclonal Antibodies and T Cell Hybridomas, Elsevier, N.Y., 1981).
As used herein, "substantially pure" describes a molecule, e.g., a protein, that is substantially free from the components that naturally accompany it. Typically, a compound is substantially pure when at least 60%, more preferably at least 75%, more preferably at least 90%, and most preferably at least 99%, of the total material in a sample is the molecule of interest.
Individuals skilled in the art will recognize that the compositions of the invention can be assembled in. a kit for the detection of SOK polypeptides or RNA. Typically, such kits include reagents containing the DNAs or antibodies of the invention with instructions and suitable packaging for their use as part of an assay for SOK. For example, a kit can contain an anti-SOK antibody that is capable of specifically forming an immunocomplex with SOK in a sample, a solid support to which the antibody is bound, and means to detect the immunocomplex.
In another aspect, the invention features a kinase inactive mutant of a SOK polypeptide, or a DNA encoding such a mutant. By "kinase inactive mutant" is meant a SOK polypeptide which has been altered so that the kinase domain is less active than in the wild-type SOK. Such mutants preferably show 50% or less of the kinase activity of wild-type SOK; more preferably, 25% or less; more preferably, 10% or less; and most preferably, 5% or less of the kinase activity of wild-type SOK. One embodiment is a kinase inactive mutant of SOK-1, in which the invariant lysine in the ATP binding site has been substituted with an arginine.
The invention also features a therapeutic composition containing a kinase inactive mutant of a SOK polypeptide, or DNA encoding such a mutant, as an active ingredient. In another aspect, the invention features a method of downregulating the gene encoding NFκB by administering a therapeutically effective amount of a kinase inactive mutant of a SOK polypeptide, or a DNA encoding such a kinase inactive mutant.
Biologically active fragments of SOK polypeptides, and DNAs encoding such polypeptides, are also included in the invention. An example of such an active fragment is the portion of the SOK-1 polypeptide corresponding to the noncatalytic carboxy terminal region of SOK-1. A "biologically active" fragment is a fragment having at least 10% of the activity of SOK in specific functions, e.g., induction of cell cycle arrest. For example, a biologically active fragment can have 30%, 50%, 80%, 90% or up to 100% or more of the activity of SOK. Such fragments include that encoded by amino acids 286 to 426 of SOK-1, and that encoded by amino acids 286 to 336 of SOK-1.
Therapeutic compositions of the invention include such active fragments, or DNAs encoding such fragments, formulated with a pharmaceutically acceptable carrier. A therapeutically effective amount of such a composition is administered to a patient, e.g., to treat a condition characterized by a proliferative response, such as balloon angioplasty-induced injury, inflammatory responses, or cancer.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. All publications mentioned herein are incorporated by reference. The examples which follow are illustrative only, and not intended to be limiting.
Other advantages and features of the invention will be apparent from the detailed description, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of the nucleotide and predicted amino acid sequences of human SOK-1.
FIG. 2 is a diagram showing an alignment of the amino acid sequence of the catalytic domain of SOK-1 with the amino acid sequence of the catalytic domains of other Ste20 homologs.
FIG. 3 is an autoradiogram of a northern blot of RNA from various tissues, hybridized to a SOK-1 probe.
FIG. 4A is an autoradiogram of a western blot of cells transfected with a HA epitope tagged-SOK-1 gene, probed with anti-HA antibody.
FIG. 4B is an autoradiogram of cells transfected with a HA epitope-tagged SOK-1 and immunoprecipitated with anti-HA antibody, followed by immune complex kinase assay using MBP as substrate.
FIGS. 5A-F are immunofluorescent stains of SOK-1-transfected cells, showing the subcellular localization of SOK-1.
FIG. 6 is a diagram showing the effect of Protein Phosphatase 2A (PP2A) and autophosphorylation on SOK activity.
FIG. 7 is a diagram showing the effect of the C-terminal non-catalytic region on SOK-1 kinase activity.
FIG. 8 is a diagram showing the kinetics of activation of SOK-1 by H 2 O 2 .
FIG. 9A is a diagram showing the effect of SOK-1 on the p38 cascade.
FIG. 9B is a diagram showing the effect of SOK-1 on the ERK1 cascade.
DETAILED DESCRIPTION
Mammalian homologs of the yeast serine/threonine protein kinase, Ste20, can be divided into two groups based on their regulation and structure. The first group, the Ste20 family, includes PAK1 and is regulated by Rac1 and cdc42Hs. Activators of protein kinases in the Ste20 family have been identified. In contrast, little has been known about activators, regulatory mechanisms or physiological roles of the second family, the Sps1 family, which includes GC kinase and MST1. The present invention is based on the identification, cloning and characterization of a human Ste20 homolog, SOK-1. Like members of the Sps1 family of Ste20 homologs, SOK-1 is characterized by an amino terminal catalytic domain. SOK-1 is positively regulated by phosphorylation, and is negatively regulated by its noncatalytic carboxy terminal region. There is no significant sequence similarity between this noncatalytic regulatory region and any other protein kinases.
SOK-1 is markedly activated by depletion of intracellular ATP stores, an important component of ischemia. This novel protein kinase is also activated by oxidant stress, and is the first mammalian Ste20 known to be activated by any cellular stress. This novel protein kinase is not activated by growth factors, alkylating agents, cytokines or environmental stresses including heat shock and osmolar stress. SOK-1 does not act as part of a generalized stress response pathway, but is activated relatively specifically by oxidant stress. Oxidant stress is a prominent component of ischemia and of reperfusion of ischemic tissue.
SOK-1 activates the transcription factor NFκB, which is implicated in a host of pathological conditions including inflammation and autoimmune syndromes. A kinase inactive mutant of SOK-1 can inhibit NFκB activity. SOK-1 also induces cell cycle arrest via a pathway that is independent of other stress activated protein kinases known to effect cell cycle arrest. This cell cycle arrest is mediated by the noncatalytic subunit of SOK-1.
Unlike GC kinase, a member of the Ste20 family, and PAK1, a member of the Sps1 family, SOK-1 does not activate any of the known MAPK pathways, such as SAPK/JNK, p38 or ERK1/-2. SOK-1 thus defines a novel stress response pathway which is likely to include a unique stress-activated MAP kinase cascade. The data suggest that SOK-1 functions similarly to yeast Ste20s, which transduce signals in response to environmental stress.
MATERIALS AND METHODS
Isolation and Analysis of SOK-1 cDNA
Degenerate sense GA(A/G)(C/T)TIATGGCIGTIAA(A/G)CA! (SEQ IF NO:8) and antisense TTIGCICC(T/C)TTIAT(A/G)TCIC(G/T)(A/G)TG! (SEQ ID NO:9) primers were used to amplify DNA from a human placenta cDNA library using Taq polymerase. The PCR products were ligated into the PCRII vector (Invitrogen). A 350 bp fragment was obtained which was not in the database but which had significant homology to the catalytic domain of protein serine/threonine kinases. This fragment was used to screen 500,000 plaques from a human B cell cDNA library in λYES (provided by Stephen J. Elledge, Department of Biochemistry, Baylor College of Medicine). Seven positive clones were isolated, and those containing the largest inserts were analyzed by DNA sequencing of both strands using the dideoxy chain termination method with Sequenase 2.0 (USB, Inc.). DNA and amino acid sequence comparisons were made using the University of Wisconsin Genetics Computer Group programs BLAST, Pileup, and Bestfit, and the BEAUTY (BLAST Enhanced Alignment Utility) and BLASTPAT (BLAST PATtern database search tool) programs from the Human Genome Center, Baylor College of Medicine.
Northern Blot Analysis
Total RNA was isolated from rat organs by the guanidinium thiocyanate-phenol-chloroform method (Witzgall et al., Mol. Cell. Biol. 13:1933 (1993)). Twenty μg of total RNA was size-fractionated on a 1% formaldehyde-agarose gel and transferred to GeneScreen Plus (NEN) membrane as described. Id. Blots were hybridized with a 409-bp HindIII-BamHI fragment from the 3' half of SOK-1 (nucleotides 995-1403) which included 284 bp of open reading frame encoding part of the non-catalytic region, and 125 bp from the 3' untranslated region. This probe was labelled with α!- 32 p dCTP by random priming. Hybridization was carried out for 18 hours at 45° C. in 5×SSPE (1×SSPE: 150 mM NaCl, 10 mM NaH 2 P0 4 , 0.7 mM EDTA), 44% formamide, 5×Denhardt's solution, 1% SDS, 10% Dextran Sulfate, and 100 μg/ml denatured salmon sperm DNA. The membranes were washed twice for 15 minutes at room temperature in 2×SSPE, twice for 30 minutes at 65° C. in 2×SSPE with 2% SDS, and once for 30 minutes at room temperature in 0.2×SSPE. Membranes were exposed to X-ray film for 5 days at -70° C. with intensifying screens.
Plasmids
Plasmids used included pMT3 (pMT2 modified to include sequence encoding the 9 amino acid hemagglutinin (HA) epitope N-terminal to the insert) (Pombo et al., Nature 377:750 (1995)), pCMVS (a CMV-based vector including sequence encoding the 9 amino acid M2 epitope tag N-terminal to the insert), PEBG (a vector that is driven by the human EF-lα promoter and that includes sequence encoding glutathione s-transferase (GST) N-terminal to the insert) (Pombo et al., Nature 377:750 (1995); Sanchez et al., Nature 372:794 (1994)), and pGEX-KG (a prokaryotic expression vector that includes sequence encoding GST N-terminal to the insert) (Guan et al., Anal. Biochem. 192:262 (1991)).
To create pCMV5-SOK-1ΔC, pCMVS-SOK-1 was cut with HindIII and then religated. The pCMV5-SOK-1ΔC construct contains sequence encoding amino acids 1-333 and includes the entire kinase domain of SOK-1, but not the carboxy terminal 93 amino acids of the protein. pEBG-SAPKpS4β, pEBG-p38, pEBG-ERK1 contain the three MAP kinases p54β (the β isoform of the SAPK, p54), p38, and ERK1, respectively, as GST fusion proteins. pRSV-BXB-Raf-1 encodes a variant of c-Raf-1 lacking the regulatory domain. BXB-Raf-1 is constitutively active and transforming (Bruder et al., Genes & Development 6:545 (1992); Pombo et al., Nature 377:750 (1995); Sanchez et al., Nature 372:794 (1994)).
Transfection Protocols and Kinase Assays
Subconfluent COS7 cells were transfected using the DEAE-dextran technique as described (Pombo et al., Nature 377:750 (1995)). One to ten μg of expression plasmid DNA were used per plate and adjusted to a total of 20 μg of DNA with the appropriate empty vector. Forty-eight hours after transfection, cells were exposed to various stimuli or vehicle, and extracts were prepared as described (Pombo et al., Nature 377:750 (1995); Pombo et al., J. Biol. Chem. 269:26546 (1994)). Extracts were exposed to anti-HA or anti-M2 (Kodak) monoclonal antibodies, or to an anti-SOK-1 rabbit polyclonal antibody (see below) for 3 hours, and immune complexes were collected with Protein G-Sepharose beads. Beads were washed three times in lysis buffer, three times in LiCl buffer (500 mM LiCl, 100 mM Tris-HCl, pH 7.61, and three times in assay buffer (Pombo et al., J. Biol. Chem. 269:26546 (1994)). Kinase assays were started by the addition of myelin basic protein (MBP, for SOK-1 and ERK1); GST-c-Jun (1-135), containing the transactivation domain of c-Jun (for SAPK) (Kyriakis et al., Nature 369:156 (1994); Pombo et al., Nature 377:750 (1995); Pombo et al., J. Biol. Chem. 269:26546 (1994)); or ATF-2 (8-94), containing the transactivation domain of ATF-2 (for p38) (Morooka et al., J. Biol. Chem. 270:30084 (1995)), in the presence of γ!- 32 P-ATP (100 μM, 3000-9000 cpm/pmole) and MgCl 2 (10 mM) After 5 to 20 minutes at 30° C., the kinase reactions were stopped with Laemmli sample buffer. Following SDS-polyacrylamide gel electrophoresis and autoradiography, the bands corresponding to the substrate were cut out of the gel and radioactivity was determined by liquid scintillation counting. For all kinase assays, an aliquot of the cell lysate was run on an SDS-polyacrylamide gel, transferred to Imobilon, and subjected to immunoblotting with the appropriate antibody to ensure equivalent expression of the kinases (Morooka et al., J. Biol. Chem. 270:30084 (1995)). Antibody binding was detected using the Enhanced Chemiluminescence System.
Phosphatase Inactivation and Reactivation Experiments
Six 10 cm dishes of COS7 cells were transfected with pMT3-SOK-1. Forty eight hours later, cell lysates were subjected to immunoprecipitation with anti-HA antibody. Immune complexes were divided into equal aliquots and then incubated for 20 minutes at 30° C. with the catalytic subunit of protein phosphatase 2A (PP2A), either with or without the PP2A inhibitor, okadaic acid (100 nM). PP2A was purified from rabbit skeletal muscle (Chen et al., Science 257:1261 (1992)) and was generously provided by Dr. David Brautigan (Center for Cell Signalling, University of Virginia Health Science Center). After the 20 minute incubation, okadaic acid was added to bring the final concentration to 100 nM in all tubes. Immune complexes were washed twice with kinase assay buffer, and then exposed to γ!- 32 P-ATP (100 μM) for 0, 5, 10, or 20 minutes prior to the addition of MBP and subsequent kinase assay for 5 minutes at 30° C.
Production of Anti-SOK-1 Polyclonal Antibodies
A peptide (amino acids 333-426) from the non-catalytic region of SOK-1 was used to generate a polyclonal rabbit antibody. This peptide was expressed in bacteria from pGEX-KG as a GST fusion protein, purified, and used to immunize rabbits according to standard protocols (Harlow et al., Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y. (1988)). The antibodies from each of two rabbits recognized 1 ng of GST-SOK1 on a Western blot when used at a 1:1000 dilution. In addition, at a 1:250 dilution, the antibody immunoprecipitated HA-SOK-1 from lysates of transfected cells.
Production of Anti-SOK-1 Monoclonal Antibodies
Monoclonal antibodies can be generated using the standard Kohler and Milstein technique.
Microinjection and Immunofluorescence
Mouse fibroblast NIH 3T3 cells were grown on glass coverslips and microinjected with the pMT3-SOK-1 expression vector, encoding SOK-1 with the HA epitope tag at its amino terminus. Plasmid DNA was purified twice on a CsCl gradient and extracted three times with phenol and chloroform. Cells were injected in a 3.5 cm dish with an automated microinjection system (AIS; Zeiss (Ansorge et al., J. Biochem Biophys. Meth. 16:283 (1988)) at a pressure between 80 and 170 kPa. The computer settings were as follows: angle, 45°; speed, 10; and time, 0.0 sec. Plasmid DNA was injected at a concentration of 100 μg/ml concentration (Pagano, Genes & Development 8:1627 (1994)). Twenty-four hours after injection, the cells were fixed with 4% paraformaldehyde for 15 minutes, treated with 0.1% SDS in phosphate buffered saline (PBS) for 5 minutes, and permeabilized with 0.5% Triton X100 (in PBS) for 15 minutes. Cells were then processed for immunofluorescence (Brown et al., J. Histochem. Cell. Biol., in press, 1996).
All antibodies were diluted in Dulbecco's modified Eagle's medium containing 10% calf serum. Coverslips were incubated with affinity purified anti-HA antibody (Boehringer Mannheim) at a final concentration of 0.026 mg/ml for one hour. After incubation for 40 minutes in biotinylated goat anti-mouse antibody (Jackson Laboratories) which was diluted 1:50, the coverslips were incubated for 40 minutes in fluorescein isothiocyanate conjugated streptavidin, diluted 1:100 (Jackson Laboratories). All incubations were carried out at 37° C. in a humidified chamber. Between each step, cells were washed three times with PBS. Nuclei were counterstained with bisbenzimide (Hoescht 33258) for 2 minutes at 1 mg/ml in PBS. Coverslips were mounted in Crystal/Mount (Biomedia) and visualized on a Zeiss Axiovert 100 photomicroscope. Cells were imaged with a Bio-Rad Laser Scanning Confocal Microscope.
Derivation of SOK-1 Kinase Inactive Mutants
A kinase inactive mutant of SOK-1 was derived by mutating the ATP binding site of SOK-1, by replacing the invariant lysine with arginine.
Identification and Characterization of SOK-1, A Novel Ste20 Homolog
Screening of the human B cell cDNA library identified two clones of 1.8 kb and 2.0 kb. The nucleotide sequence of the gene encoded by these overlapping clones, and the deduced amino acid sequence of the protein encoded by this gene, are shown in FIG. 1. For the nucleotide sequence, numbers refer to the position of the codon relative to the initiator ATG. The predicted translation product is indicated below the nucleotide sequence, and the numbers refer to the position of the amino acid relative to the initial methionine. The 2.0 kb clone contains a Kozak sequence (gcggccatgg)(SEQ ID NO:10) at a candidate initiation codon (FIG. 1). There is an in-frame stop codon 15 bp 5' of this initiation codon. There are no other candidate initiation codons between this stop codon and the ATG, which suggests that this codon is the true translation start site. A poly (A) tail is present at the 3' end of the 1.8 kb clones.
The open reading frame encodes a protein which is 426 amino acids in length and has a predicted molecular mass of 48,041 daltons. The kinase domain is located in the amino terminal half of the protein and contains all 11 subdomains of serine/threonine kinases (Hanks et al., In Methods in Enzymology, Hunter et al., eds., Academic Press, San Diego, Calif., pp. 38-62 (1991)). Alignment of the catalytic domain of SOK-1 with the catalytic domains of the five most closely related kinases as determined by the BLAST and Bestfit programs is shown in FIG. 2. The deduced amino acid sequences of PAK1 (Manser et al., Nature 367:40 (1994)); Ste20 (Leberer et al., EMBO J. 11:4815 (1993)); MST1 (Creasy et al., J. Biol. Chem. 270:21695 (1995)); Sps1 (Friesen et al., Genes & Development 8:2162 (1994)); and GC kinase (Katz et al., J. Biol. Chem. 269:16802 (1994)) were aligned by eye after being aligned with the Pileup program. Gaps, which were introduced to maintain alignment, are denoted by dots. Roman numerals indicate the eleven protein serine/threonine kinase subdomains (Hanks et al., In Methods of Enzymology, Hunter et al., eds., pp. 38-62, Academic Press, Inc., San Diego, Calif. (1991)). Residues that are conserved in all family members are enclosed in boxes. Comparison of the amino acid sequence of the catalytic domain with other protein kinases using the BLAST program identified the yeast kinase, Sps1 (Friesen et al., Genes & Development 8:2162 (1994)), and the mammalian kinases, MST1 (Creasy et al., J. Biol. Chem. 270:21695 (1995)) and GC kinase (Katz et al., J. Biol. Chem. 269:16802 (1994)) as its closest homologs. Within the catalytic domain, SOK-1 was 50% identical and 68% similar to Sps1, 56% identical and 73% similar to MST1, and 51% identical and 68% similar to GC kinase.
The five kinases most closely related to SOK-1 are Sps1, MST1, GC kinase, Ste20 (Leberer et al., EMBO J. 11:4815 (1993)), and PAK1 (Manser et al., Nature 367:40 (1994)), all of which are Ste20 homologs. Alignment of the amino acid sequence of the catalytic domains of Sps1 and Ste20 with SOK-1 indicates a high degree of evolutionary conservation (FIG. 2). Comparison of the amino acid sequence of the C-terminal non-catalytic region of SOK-1 with the database using the BLAST, BEAUTY, and BLASTPAT programs failed to identify regions of significant homology with any other kinases.
SOK-1 is thus related to the Sps1 family of Ste20s on the basis of its organization, i.e., amino terminal catalytic domain, and sequence similarity within the kinase domain to the Sps1 group. SOK-1 is more similar in sequence to Sps1 (50% identical) than it is to Ste20 (42% identical). Furthermore, Sps1 is more similar to SOK-1 than Sps1 is to Ste20 (44% identical).
SOK-1 Expression
mRNA was extracted from various rat tissues and subjected to Northern blot analysis using a probe from the carboxy terminal non-catalytic region of SOK-1. Expression of a 2300 bp mRNA was detected in all tissues examined except stomach, where the probe hybridized to two transcripts, one of approximately 2600 bp and one of 1500 bp (FIG. 3). Highest levels of expression were in testis, large intestine, brain, and stomach. Intermediate levels of expression were seen in heart and lung. Equal loading of all lanes in the gel was confirmed by ethidium bromide staining. The kinase was expressed in the two human B cell lines examined, Ramos, a Burkitt lymphoma cell line that has features of a germinal center B cell, and HS Sultan, a mature B cell line.
COS7 cells were transfected with pMT3-SOK-1, which encodes a SOK-1 protein with a nine amino acid HA epitope tag on the amino terminus. The results of Western blotting using a monoclonal anti-HA antibody as a probe of the pMT-3SOK-1 transfected cells (+), as well as cells transfected with the vector without the SOK-1 insert (-) are shown in FIG. 4A. Transfection with pMT3-SOK-1, but not the vector alone, resulted in expression of a protein with an approximate molecular weight of 50 kDa (indicated by the arrow in FIG. 4A). The kinase displayed a high degree of constitutive activity toward MBP in immune complex kinase assays. The results of a typical experiment in which COS7 cells were transfected with pMT3 vector alone (-), or 1 μg (1) or 5 μg (5) pMT3-SOK-1 is shown in FIG. 4B. Forty eight hours after transfection, the cells were harvested and lysates were subjected to immunoprecipitation with anti-HA antibody followed by immune complex assay using MBP as substrate. Phosphoamino acid analysis demonstrated that the kinase phosphorylated MBP on serine and threonine residues, but not on tyrosine.
To determine subcellular localization of SOK-1, pMT3-SOK-1, encoding HA-SOK-1, was microinjected into NIH3T3 fibroblasts at a concentration of 100 μg/ml. HA-SOK-1 was detected by staining with the anti-HA antibody as described supra. SOK-1 was localized almost exclusively in the cytoplasm (FIGS. 5B and 5E). A representative slice of 0.2 μm of the same cells is also shown in FIGS. 5A and 5D. The cells were counterstained with Hoescht 33258 to visualize the nuclei (FIGS. 5C and 5F).
Regulation of SOK-1
The role of phosphorylation in the regulation of SOK-1 was explored. Exposure of SOK-1 to protein serine phosphatase 2A (PP2A) in immune complexes reduced SOK-1 kinase activity by approximately 40%. This effect of PP2A was prevented by co-incubation with the PP2A inhibitor okadaic acid (OA). To determine whether autophosphorylation might play a role in activating SOK-1, the protein was partially inactivated by PP2A, then incubated with γ- 32 P-ATP (100 μM) and assayed for reactivation (FIG. 6). Reactivation of SOK-1 kinase activity which correlated with phosphorylation of a 50 kDa protein in the immune complex. The increase in kinase activity over time correlated with the degree of phosphorylation. The phosphorylated protein also demonstrated enhanced electrophoretic mobility after PP2A treatment and retarded mobility after incubation with ATP (FIG. 6). The data thus suggest that phosphorylation, probably autophosphorylation, is an important mechanism of activation of SOK-1.
Autophosphorylation and autoactivation of a kinase in immune complexes, if unrecognized, greatly complicates the identification of activators. After a twenty minute incubation in the presence of ATP, MBP kinase activity of SOK-1 previously inactivated by PP2A, was equal to that of SOK-1 which had not been inactivated by PP2A (FIG. 6). Autophosphorylation and autoactivation may explain the difficulty which has been encountered in identifying activators of the Sps1 family of Ste20 homologs when standard immune complex kinase assays are performed. Under these conditions, no activators of MST1 were identified (Creasy et al., J. Biol. Chem. 270:21695 (1995)), and for GC kinase, TNFA only weakly stimulated kinase activity. Since SOK-1 is markedly activated by autophosphorylation in immune complex kinase assays, incubations for kinase assays of longer than 5 minutes can be expected to mask any differences between control and stimulated cells. Consequently, all subsequent kinase assays were performed for 5 minutes.
SOK-1 has an amino terminal catalytic domain, placing it, on the basis of organization, in the Sps1 group of Ste20s, which includes Sps1, GC kinase, and MST1. These kinases lack the Rac1/cdc42Hs binding domain present in the regulatory domains of Ste20 and the PAK family of kinases, and the role of their carboxy terminal non-catalytic regions is unclear. The ability of the carboxy terminal region of SOK-1 to regulate kinase activity in transfected COS7 cells was tested (FIG. 7). Using MBP as a substrate, the kinase activity of SOK-1, expressed from pCMV5-SOK-1, which encodes SOK-1 with a nine amino acid M2 epitope tag at the amino terminus, was compared with that of M2-SOK-1ΔC, a deletion mutant containing the catalytic domain but missing the carboxy terminal 95 amino acids of the non-catalytic region, and pCMV5, which is the vector containing the M2 epitope tag, but lacking the SOK-1 sequences. Although the cellular extracts were matched for total protein prior to immunoprecipitation with anti-M2 antibody, immunoblots of the extracts revealed that M2-SOK-1ΔC was expressed at a much lower level than full-length M2-SOK-1 (FIG. 7, bottom). Despite the lower expression of M2-SOK-1ΔC, and the presence of much less M2-SOK-1ΔC compared to full-length M2-SOK-1 in the immunoprecipitates, kinase activity, measured as phosphorylation of MBP, was equivalent, consistent with significantly greater specific activity of M2-SOK-1ΔC (FIG. 7). These data suggest that the carboxy terminal non-catalytic region inhibits kinase activity of SOK-1 and is the first demonstration of a role for the non-catalytic region of protein kinases related to the Sps1 group of Ste20s. Inhibition of activity may be due to binding of the carboxy terminal region to the catalytic domain, since the carboxy terminal region (lacking the kinase domain) co-immunoprecipitates with SOK-1ΔC when the two are co-expressed. The carboxy terminal region may exert its inhibitory effect by preventing access by an activator, possibly SOK-1 itself, to a critical site within the catalytic domain, or by inhibiting interaction of the kinase domain with substrates.
SOK-1 is thus regulated by its non-catalytic region, and by phosphorylation. Identification of these two regulatory mechanisms suggests that the regulation of SOK-1 may be similar to the regulation of PAK1. Binding of the inhibitory regulatory region of PAK1 to the small GTP binding proteins appears to allow the kinase to undergo autophosphorylation, which activates the kinase. For SOK-1, binding of the inhibitory regulatory region to an as yet unidentified activator may also allow autophosphorylation and activation to occur. Thus, the primary mechanism of activation of PAK1 and SOK-1 (and possibly other Ste20s) would be similar (autophosphorylation), but the activators to which the regulatory domains bind, allowing autophosphorylation to occur, would differ. Specificity in the activation of Ste20s (and subsequently, MAP kinase cascades) in response to a stimulus could be determined by protein or lipid interaction domains within the regulatory region.
Activation of SOK-1 by Depletion of ATP Stores
SOK-1 is markedly activated by the depletion of intracellular ATP stores, an important component of ischemia. Ischemia is a major cause of morbidity and mortality, and clinically presents as myocardial infarction, stroke, and acute renal failure. Several kinases are activated after reperfusion or after repletion of ATP stores, but SOK-1 is activated during the phase of ATP depletion, suggesting that it is a very early modulator of the response to ATP depletion and therefore ischemia.
Activation of SOK-1 by H 2 O 2
Incubation of Ramos B cells with okadaic acid (1 μM, 20 minutes) activated SOK-1 (Table 1), compatible with regulation of SOK-1 (and/or an upstream activator) by phosphorylation. Numerous agonists that were representative of multiple different classes of stimuli were also tested for their ability to activate SOK-1. Only H 2 O 2 consistently activated SOK-1 when native kinase was assayed after immunoprecipitation from Ramos B cells or when HA-tagged SOK-1 was assayed after immunoprecipitation from transfected COS7 cells (Table 1). H 2 O 2 (0.5 mM) activated SOK-1 approximately 3-fold (p<0.01). No H 2 O 2 -induced increase in MBP kinase activity was detected when immunoprecipitation was performed with preimmune serum. Activation of SOK-1 was evident as early as 10 minutes following exposure of Ramos B cells to H 2 O 2 , peaked at 20 minutes, and remained elevated at 60 minutes (FIG. 8). Activation was evident at 0.1 mM, the lowest concentration tested (2.1-fold increase in kinase activity). SOK-1 is thus markedly activated by oxidant stress. Oxidant stress is a prominent component of ischemia, and of reperfusion of ischemic tissue. Oxidant stress also occurs with ionizing radiation, such as ultraviolet or gamma radiation, and is an important element of inflammation.
This is the first clear demonstration of activation of a member of this group of Ste20s by any stimulus. The activation of SOK-1 by H 2 O 2 not only identifies a new oxidant stress response signal transduction pathway, but also suggests that one role of this and possibly other Ste20s of this group is to respond to environmental stresses just as their homologs do in the simplest eukaryotes. The survival of aerobic organisms depends upon their mounting an effective response to oxidant stress. Activation by oxidant stress suggests that SOK-1, and possibly other as yet unidentified SOK-1 homologs, may, like the Ste20s identified thus far in yeast, play an important role in the responses of the cell to environmental stress.
In contrast to activation of SOK-1 by H 2 O 21 potent activators of the ERK1/-2 cascade, such as epidermal growth factor (EGF), platelet-derived growth factor (PDGF) and the phorbol ester phorbol myristate acetate (PMA) combined with the calcium ionophore, ionomycin, did not activate SOK-1 (Table 1). In the same COS7 cells, these agonists activated ERK1, expressed in pEBG, 5- to 7-fold. Oxidant stress appeared to be a specific activator among the several cellular stresses tested. Specifically, high and low osmolar stress, heat shock, tumor necrosis factor α (TNFα), and anisomycin, which potently activate the SAPK and/or p38 cascades in these and other cells (see Figs. and Galcheva-Gargova et al., Science 265:806 (1994); Han et al., Science 265:808 (1994); Kyriakis et al., Nature 369:156 (1994); Pombo et al., Nature 377:750 (1995); Rouse et al., Cell 78:1027 (1994)), did not activate SOK-1. Platelet activating factor, which signals via a heterotrimeric G protein-coupled receptor and is a potent activator of intracellular Ca 2+ transients in Ramos cells, was also ineffective.
TABLE 1______________________________________Fold-activation of native SOK-1 in Ramos Bcells and HA-SOK-1 in COS7 cells.Agonist Ramos COS7______________________________________H.sub.2 O.sub.2 (0.5 mM, 20 min) 2.9 2.8Okadaic acid (1 μM, 30 min) 2.3 --Interferon-γ (50 ng/ml, 20 min) 1.0 --TNFα (50 ng/ml, 20 min) 1.5 0.9Anti-Ig (20 min) 0.8 --Platelet activating factor (1 μM, 20 min) 1.4 --PMA/Ionomycin (300 nM/1 μM, 20 min) 1.4 1.4Nitrogen mustard (10 μM, 30 min) 1.2 1.4Cyclophosphamide (10 μM, 30 min) 0.9 1.5cisplatin (10 μM, 30 min) 1.0 1.1Heat shock (42° C., 5 min) -- 0.9Anisomycin (50 μg/ml, 20 min) -- 1.1Hyperosmolarity (NaCl 700 mM, 15 min) -- 0.9Hypoosmolarity (150 mOsm, 15 min) -- 0.9EGF (100 ng/ml, 10 min) -- 1.3PDGF (20 ng/ml, 10 min) 1.0 1.2______________________________________ -- = not determined.
Native SOK-1 in Ramos B cells was assayed with MBP as substrate after immunoprecipitation with rabbit polyclonal anti-SOK-1. HA-SOK-1 was assayed after immunoprecipitation with anti-HA antibody from extracts of COS7 cells which had been transfected with pMT3-SOK-1 (5 μg per 10 cm dish).
Hypoosmolar stress was induced by placing cells in Krebs-Henseleit buffer without NaCl (Pombo et al., 1994).
Reactive oxygen radicals, via damage to many cellular components including DNA, can cause cell death, or if less severe, cell cycle arrest at either the G 1 or G 2 checkpoint (Russo et al., J. Biol. Chem. 270:29386 (1995)). DNA damage not only activates checkpoint controls, but may also activate protein kinases, including the SAPKs, c-Raf-1, and ERKs, which are integral components of cytoplasmic signal transduction cascades, as well as the non-receptor tyrosine kinase c-abl (Hibi et al., Genes & Development 7:2135 (1993); Kharbanda et al., Nature 376:785 (1995); Kharbanda et al., J. Biol. Chem. 270:18871 (1995); Livingstone et al., EMBO J. 14:1785 (1995); Radler-Pohl et al., EMBO J. 12:1005 (1993); Russo et al., J. Biol. Chem. 270:29386 (1995); Van Dam et al., EMBO J. 14:1798 (1995)). In order to determine whether activation of SOK-1 was likely to be triggered by DNA damage or by oxidant stress acting via a DNA damage-independent mechanism, alkylating agents were tested for their ability to activate SOK-1. Alkylating agents activate the DNA damage-induced checkpoint controls and protein kinases, but do not produce oxidant stress. Exposure of transfected COS7 cells to the alkylating agents cyclophosphamide, nitrogen mustard, and cisplatin did not activate SOK-1, suggesting that oxidant stress-induced activation of SOK-1 is not mediated by DNA damage response pathways. Thus, activation of SOK-1 by oxidant stress is not part of a generalized response to either cellular or genotoxic stress. Cross-linking surface IgM on Ramos B cells with anti-Ig antibody coupled to beads, which induces apoptosis in these cells, did not activate SOK-1 but did markedly enhance tyrosine phosphorylation of several proteins in these cells.
Although these data clearly place SOK-1 on an oxidant stress response pathway, SOK-1 does not appear to activate the known stress-activated MAP kinase pathways. It has recently been reported that SOK-1 (previously called UK1; the name was changed to SOK-1 to reflect the fact that the kinase is activated by oxidant stress), unlike the closely related GC kinase, did not activate the SAPKs in co-transfection experiments (Pombo et al., Nature 377:750 (1995)). Co-transfection of HA-SOK-1 with the other MAP kinases, p38 (FIG. 9A) and ERK1 (FIG. 9B), both expressed in PEBG, did not result in the activation of the MAP kinases. In the p38 experiments, COS7 cells were transfected with PEBG vector (p38-) or PEBG encoding p38 as a GST fusion protein (p38+), and either pMT3 vector (SOK-1-) or pMT3 encoding HA tagged SOK-1 (SOK-1+). To confirm that p38 could be activated, cells were exposed to NaCl (500 mM) for 10 minutes (NaCl+). p38 kinase activity was assayed with ATF-2 (8-94) as substrate (Morooka et al., J. Biol. Chem. 270:30084 (1995)). p38 was markedly activated by exposure of cells to osmolar stress.
In the ERK1 experiments, COS7 cells were transfected with PEBG vector (ERK1-) or pEBG encoding ERK1 as a GST fusion protein (ERK1+), and either pMT3 vector (SOK-l-), pMT3 encoding HA-tagged SOK-1 (SOK-1+), or as a positive control, pMT3 encoding BXB-Raf (+), a constitutively active c-Raf-1 that is missing the amino terminal regulatory domain (Bruder et al., Genes & Development 6:545 (1992)). ERK1 assays were performed in duplicate with MBP as substrate. As shown in FIG. 9B, ERK1 was activated by co-transfection of pRSV-BXB-Raf-1, but not SOK-1.
Oxidant stress activates the ERKs, and may activate the SAPKs somewhat (Kyriakis et al., Nature 369:156 (1994); Russo et al., J. Biol. Chem. 270:29386 (1995)), but SOK-1 does not appear to be implicated in this activation. SOK-1 did not activate any of four MAP kinase cascades, including SAPKs (Pombo et al., Nature 377:750 (1995)); p38 (FIG. 9A); ERK1 (FIG. 9B); or MEK5/ERK5 (Zhou et al., J. Biol. Chem. 270:12665 (1995)), further indicating that the stress response pathway regulated by SOK-1 is unique. Since evolutionary conservation of the activation of MEKK/MEK/MAPK cascades by Ste20s extends to mammals (Polverino et al., J. Biol. Chem. 270:26067 (1995)); Pombo et al., Nature 377:750 (1995); Zhang et al., J. Biol. Chem. 270:12665 (1995)), and all Ste20s identified to date in yeast or mammals, with the exception of MST1 (Creasy et al., J. Biol. Chem. 270:21695 (1995)) have been shown to activate one or more MAP kinase cascades, it is likely that SOK-1 controls a novel oxidant stress-activated MAP kinase cascade.
SOK-1 Functions
NFκB is a ubiquitously expressed transcription factor that is believed to be critical to diverse processes including T lymphocyte activation, the expression of cellular adhesion molecules, and the expression of interferon β. NFκB appears to play vital roles in transplant rejection, post-ischemic injury, the response to viral infection, and inflammation. Many diverse genes are believed to be under the control of NFκB. NFκB is activated by cytokines, such as TNFα, IL-1β, and IL-2; lipopolysaccharide, the mediator of septic shock; viruses, including Human T Cell Leukemia Virus Type 1, Human Immunodeficiency Virus 1, and Hepatitis B; ultraviolet and X-irradiation; antigen stimulation of T and B lymphocyte receptors; and the tumor promoting phorbol esters. In addition, most, if not all, of the activators of NFκB result in oxidant stress. Therefore, SOK-1 could be a final common pathway for activation of NFκB, and SOK-1 having an inactive kinase domain could be a general inhibitor of NFκB. In order to test these hypotheses, reporter plasmids containing NFκB binding sites linked to the Interleukin 2 (IL-2) receptor α-chain promoter were constructed. SOK-1 activated IL-2 receptor α-chain expression from these constructs, indicating that SOK-1 activates NFκB. In addition, transfection of SOK-1 causes an increase in the binding of a nuclear protein to an oligonucleotide containing a consensus NFκB binding site.
A kinase inactive mutant of SOK-1 was constructed by changing the invariant lysine in the ATP binding site to an arginine. This kinase inactive mutant suppresses nuclear protein binding to the oligonucleotide containing the NFκB consensus binding site. Transcription from the NFκB reporter plasmid is also inhibited by the mutant protein. The kinase inactive mutant thus serves as a dominant inhibitor of activation of NFκB. Inhibitors of NFκB have not heretofore been identified, although they have been sought extensively, since it is believed that inhibition or stimulation of NFκB in inflammatory and autoimmune diseases, as well as cancer or viral infection, may be palliative or curative. Verma et al., Genes & Development 9:2723 (1995).
SOK-1 and Cell Cycle Arrest
Experiments were performed to investigate the role of SOK-1 in the induction of cell cycle arrest, which occurs in many types of cells following oxidant stress. In these experiments, NIH3T3 cells on coverslips were synchronized in G o by serum withdrawal. After twenty-four hours, less than 1% of the cells continued to cycle. Arrested cells were released with 10% calf serum, and were microinjected in early G 1 phase with the pCMV5 vector alone, or pCMV5 containing the gene encoding M2 epitope-tagged SOK-1. Entry into S phase was determined by monitoring BrdU (0.1 mM) incorporation. After microinjection of the pCMV5 vector alone, over 90% of cells entered S phase. In contrast, after injection of pCMV5-SOK-1, less than 5% of cells entered S phase. Injection of a kinase inactive mutant of SOK-1 also induced cell cycle arrest (<5% of cells in S phase).
Since both SOK-1 and the kinase inactive mutant were effective in maintaining cells in G 1 , the non-catalytic carboxy terminal region of the kinase might be mediating cell cycle arrest. To test this hypothesis, pCMV5 containing only the non-catalytic region (nucleotides 858 to 1278, encoding amino acids 286 to 426) of the SOK-1 gene was injected into NIH3T3 cells. Like the constructs containing the full length SOK-1 or the kinase inactive mutant, this construct also induced G 1 arrest (<5% of cells in S phase) SOK-1 thus potently induces arrest in G 1 of the cell cycle, via a mechanism that is not dependent upon the protein's catalytic function. A fragment of the SOK-1 polypeptide of approximately forty amino acids, from amino acid 286 to 336, may be sufficient to induce cell cycle arrest.
SOK-1-mediated cell cycle arrest occurs independently of the p38 and other MAP kinases that are known to induce cell cycle arrest. The ability of SOK-1 to induce cell cycle arrest, as well as to activate NFκB, makes SOK-1 an ideal target for drug development. The ability of SOK-1 to cause cell cycle arrest also suggests that it could be used following balloon angioplasty-induced injury of blood vessels, in order to inhibit the proliferative response which accompanies such injuries and causes restenosis. SOK-1 can also be used to treat other conditions that are characterized by proliferative responses, including inflammatory responses, tumors, and conditions such as atherosclerosis.
Transgenic Animals
SOK polypeptides can also be expressed in transgenic animals. SOK transgenic animals are useful for screening for compounds that enhance or down regulate SOK expression or activity. Animals of any species, including, but not limited to, mice, rats, rabbits, guinea pigs, pigs, micro-pigs, goats, and non-human primates, e.g., baboons, monkeys, and chimpanzees, can be used to generate SOK expressing transgenic animals.
Various techniques known in the art can be used to introduce a SOK transgene into animals to produce the founder lines of transgenic animals. Such techniques include, but are not limited to, pronuclear microinjection (U.S. Pat. No. 4,873,191); retrovirus mediated gene transfer into germ lines (Van der Putten et al., Proc. Natl. Acad. Sci. USA, 82:6148 (1985); gene targeting into embryonic stem cells (Thompson et al., Cell, 56:313 (1989)); and electroporation of embryos (Lo, Mol. Cell Biol, 3:1803 (1983)).
The present invention provides for transgenic animals that carry the SOK transgene in all their nucleated cells, as well as animals that carry the transgene in some, but not all of their nucleated cells, i.e., mosaic animals. The transgene can be integrated as a single transgene or in concatamers, e.g., head-to-head tandems or head-to-tail tandems. For example, transgenic animals can be made in which SOK-1 is under the control of an inducible promoter. The transgene can also be selectively introduced into and/or activated in a particular cell type. Lasko et al., Proc. Natl. Acad. Sci. USA, 89:6232 (1992). The regulatory sequences required for such a cell-type specific activation will depend upon the particular cell type of interest, and will be apparent to those of skill in the art.
Vectors containing some nucleotide sequences homologous to an endogenous SOK gene can be designed for the purpose of integrating via homologous recombination into the endogenous gene and disrupting its function, i.e., making "knockout mice." The transgene also can be selectively introduced into a particular cell type, thus inactivating the endogenous SOK-1 gene in only that cell type. See Gu et al., Science, 265:103 (1984). The regulatory sequences required for such a cell-type specific inactivation will depend upon the particular cell type of interest, and will be apparent to those of skill in the art.
Once transgenic animals have been generated, the expression of the recombinant SOK gene can be assayed utilizing standard techniques. Initial screening can be accomplished by Southern blot analysis or PCR techniques to analyze animal tissues to assay whether integration of the transgene has taken place. The level of mRNA expression of the transgene in the tissues of the transgenic animals can also be assessed using techniques which include, but are not limited to, Northern blot analysis of tissue samples obtained from the animal, in situ hybridization analysis, and RT-PCR. Samples of tissues expressing SOK can also be evaluated immunocytochemically using antibodies specific for the SOK transgene product.
Therapeutic Compositions
The therapeutic compositions of the invention can be used to increase SOK expression or activity in a patient to treat a pathological condition, e.g., a condition associated with a proliferative response, such as inflammatory responses, cancer, atherosclerosis or ballon angioplasty-induced injury to blood vessels. The therapeutic compositions of the invention can also be used to treat pathological conditions associated with NKFB expression, such as transplant rejection, post ischemic injury, and the response to viral infection. These compositions can contain the polypeptides or DNAs of the invention, including SOK-1 or a fragment thereof, or a kinase inactive mutant of SOK-1. Polypeptides can be purified by methods that are known to those skilled in the art. Ausubel et al., Current Protocols in Molecular Biology, John Wiley & Sons, New York, 1995. DNAs can be administered in a manner allowing their uptake and expression by cells in vivo. DNAs can be administered to the patient by standard vectors and/or gene delivery systems. Suitable gene delivery systems include liposomes, biolistic transfer, receptor-mediated delivery systems, naked DNA and viral vectors such as herpes viruses, retroviruses, adenoviruses and adeno-associated viruses. The polypeptides and DNAs of the invention are administered with a pharmaceutically acceptable carrier, and are formulated according to procedures that are well known to those skilled in the art.
Parenteral administration, such as intravenous, subcutaneous, intramuscular or intraperitoneal delivery routes can be used to deliver the therapeutic compositions of the invention. Dosages for particular patients depend upon many factors, including the patient's size, body surface area, age, the particular substance to be administered, time and route of administration, general health and other drugs being administered concurrently. The amount of therapeutic composition to be administered to a patient can be in the range of 1 to 1000 μg/kg of body weight, e.g., 10 to 500, or 20 to 200 μg/kg of body weight. A typical dose of polypeptide or DNA to be administered to a patient is 100 μg per kilogram of body weight.
Diagnostic Applications
Anti-SOK-1 antibodies can be used to assay tissues for SOK-1; elevated SOK-1 levels may be indicative of cell stress caused, e.g., by ischemia resulting from insults such as stroke and myocardial infarction. Immunoassays using anti-SOK-1 antibody are carried out by standard techniques; e.g., the antibody can be labelled with a detectable label and contacted with a tissue sample under conditions which allow immune complexes to form. The uncomplexed labelled antibody is removed, and labelled immune complexes measured as a measure of SOK-1 in the sample. Immunoassays that can be performed using SOK-1 antibodies are well known to those skilled in the art. See e.g., Ausubel et al., Current Protocol in Molecular Biology 2:11:2, John Wiley & Sons, 1995. Immunoassays can utilize radioactive, enzyme-based, or chemiluminescent labels.
__________________________________________________________________________SEQUENCE LISTING(1) GENERAL INFORMATION:(iii) NUMBER OF SEQUENCES: 10(2) INFORMATION FOR SEQ ID NO:1:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 1975 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(ix) FEATURE:(A) NAME/KEY: Coding Sequence(B) LOCATION: 127...1404(xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:CACCGAGCGCCCCTGGTGTCCCTCGTAGTGGACTGACGCCGCAGGGCGAGCTAGCCGGCT60CCGCGCCTCTCCGCGGATCCAGACGCCTCCTGGGGCTGCTGGCGGAGGGTCTGAGGCGGC120GCGGCCATGGCTCACCTCCGGGGATTTGCAAACCAGCACTCTCGAGTG168MetAlaHisLeuArgGlyPheAlaAsnGlnHisSerArgVal1510GACCCTGAGGAGCTCTTCACCAAGCTCGACCGCATTGGCAAGGGCTCG216AspProGluGluLeuPheThrLysLeuAspArgIleGlyLysGlySer15202530TTTGGGGAGGTCTACAAGGGCATCGATAACCACACAAAGGAGGTGGTG264PheGlyGluValTyrLysGlyIleAspAsnHisThrLysGluValVal354045GCCATCAAGATCATCGACCTGGAGGAGGCCGAGGATGAGATCGAGGAC312AlaIleLysIleIleAspLeuGluGluAlaGluAspGluIleGluAsp505560ATCCAGCAGGAGATCACTGTCCTCAGTCAGTGCGACAGCCCCTACATC360IleGlnGlnGluIleThrValLeuSerGlnCysAspSerProTyrIle657075ACCCGCTACTTTGGCTCCTACCTAAAGAGCACCAAGCTATGGATCATC408ThrArgTyrPheGlySerTyrLeuLysSerThrLysLeuTrpIleIle808590ATGGAGTACCTGGGCGGCGGCTCAGCACTGGACTTGCTTAAACCAGGT456MetGluTyrLeuGlyGlyGlySerAlaLeuAspLeuLeuLysProGly95100105110CCCCTGGAGGAGACATACATTGCCACGATCCTGCGGGAGATTCTGAAG504ProLeuGluGluThrTyrIleAlaThrIleLeuArgGluIleLeuLys115120125GGCCTGGATTATCTGCACTCCGAACGCAAGATCCACCGAGACATCAAA552GlyLeuAspTyrLeuHisSerGluArgLysIleHisArgAspIleLys130135140GCTGCCAACGTGCTACTCTCGGAGCAGGGTGACGTGAAGCTGGCGGAC600AlaAlaAsnValLeuLeuSerGluGlnGlyAspValLysLeuAlaAsp145150155TTTGGGGTAGCAGGGCAGCTCACAGACACGCAGATTAAGAGGAACACA648PheGlyValAlaGlyGlnLeuThrAspThrGlnIleLysArgAsnThr160165170TTCGTGGGCACCCCCTTCTGGATGGCACCTGAGGTCATCAAGCAGTCG696PheValGlyThrProPheTrpMetAlaProGluValIleLysGlnSer175180185190GCCTACGACTTCAAGGCTGACATCTGGTCCCTGGGCATCACAGCCATC744AlaTyrAspPheLysAlaAspIleTrpSerLeuGlyIleThrAlaIle195200205GAGCTGGCCAAGGGGGAGCCTCCAAACTCTGACCTCCACCCCATGCGC792GluLeuAlaLysGlyGluProProAsnSerAspLeuHisProMetArg210215220GTCCTGTTCCTGATTCCCAAGAACAGCCCACCCACACTGGAGGGCCAG840ValLeuPheLeuIleProLysAsnSerProProThrLeuGluGlyGln225230235CACAGCAAGCCCTTCAAGGAGTTCGTGGAGGCCTGCCTCAACAAAGAC888HisSerLysProPheLysGluPheValGluAlaCysLeuAsnLysAsp240245250CCCCGATTCCGGCCCACGGCCAAGGAGCTCCTGAAGCACAAGTTCATC936ProArgPheArgProThrAlaLysGluLeuLeuLysHisLysPheIle255260265270ACACGCTACACCAAGAAGACCTCCTTCCTCACGGAGCTCATCGACCGC984ThrArgTyrThrLysLysThrSerPheLeuThrGluLeuIleAspArg275280285TATAAGCGCTGGAAGTCAGAGGGGCATGGCGAGGAGTCCAGCTCTGAG1032TyrLysArgTrpLysSerGluGlyHisGlyGluGluSerSerSerGlu290295300GACTCTGACATTGATGGCGAGGCGGAGGACGGGGAGCAGGGCCCCATC1080AspSerAspIleAspGlyGluAlaGluAspGlyGluGlnGlyProIle305310315TGGACGTTCCCCCCTACCATCCGGCCGAGTCCACACAGCAAGCTTCAC1128TrpThrPheProProThrIleArgProSerProHisSerLysLeuHis320325330AAGGGGACGGCCCTGCACAGTTCACAGAAGCCTGCGGACGCCGTCAAG1176LysGlyThrAlaLeuHisSerSerGlnLysProAlaAspAlaValLys335340345350AGGCAGCCGAGGTCCCAGTGCCTGTCCACGCTGGTCCGGCCCGTCTTC1224ArgGlnProArgSerGlnCysLeuSerThrLeuValArgProValPhe355360365GGAGAGCTCAAAGAGAAGCACAAGCAGAGCGGCGGGAGCGTGGGTGCG1272GlyGluLeuLysGluLysHisLysGlnSerGlyGlySerValGlyAla370375380CTGGAGGAGCTGGAGAACGCCTTCAGCCTGGCCGAGGAGTCCTGCCCC1320LeuGluGluLeuGluAsnAlaPheSerLeuAlaGluGluSerCysPro385390395GGCATCTCAGACAAGCTGATGGTGCACCTGGTGGAGCGAGTGCAGAGG1368GlyIleSerAspLysLeuMetValHisLeuValGluArgValGlnArg400405410TTTTCACACAACAGAAACCACCTGACATCCACCCGCTGAAGCGCACTGCTGT1420PheSerHisAsnArgAsnHisLeuThrSerThrArg415420425TCAGATAGGGGACGGAAGGTCGTTTGTTTTTGTTCTGAGCTCCATAAGAACTGTGCTGAC1480TTGGAAGGTGCCCTGTGCTATGTCGTGCCTGCAGGGACACGTCGGATCCCGTGGGCCTCA1540CATGCCAGGTCACCAGGTCACCGTCTCCTTCCACCCCTGCAGTGTGCTGTTGTGCACGTC1600AGGACGCTGTTCTCTATGCCACTGCCTCCTCCCTCTCCTGGCCCAGCAGTATTGCTCACG1660GGGGCTCCAGCCGCCGGCGTGGCCCTCATGAGCTACGCCTGGGTCTTCTGCAGACTCATG1720CAGCCCTATGGCCGCTCAGACCAAGGCGCAGAGCAACTATCAGGGCATGCTCTGCCTCCT1780CCTCCCATTGAGGTGGGGAGAGGCAACAGGGCAGCCCCCAGAGGAGTGTCCTGGCCGCTG1840TCTCCCGGGCCCATGATGGCCATAGATTTGCCTTGTGGTGTTCCATCAGGTACTGTGTCT1900GCTCATAAGTACTTGTGTCATCCAGAATGTTTTGTTTTTTAAGAAAATTGAATTACTTGT1960TTCCTGAAAAAAAAA1975(2) INFORMATION FOR SEQ ID NO:2:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 426 amino acids(B) TYPE: amino acid(D) TOPOLOGY: linear(ii) MOLECULE TYPE: protein(v) FRAGMENT TYPE: internal(xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:MetAlaHisLeuArgGlyPheAlaAsnGlnHisSerArgValAspPro151015GluGluLeuPheThrLysLeuAspArgIleGlyLysGlySerPheGly202530GluValTyrLysGlyIleAspAsnHisThrLysGluValValAlaIle354045LysIleIleAspLeuGluGluAlaGluAspGluIleGluAspIleGln505560GlnGluIleThrValLeuSerGlnCysAspSerProTyrIleThrArg65707580TyrPheGlySerTyrLeuLysSerThrLysLeuTrpIleIleMetGlu859095TyrLeuGlyGlyGlySerAlaLeuAspLeuLeuLysProGlyProLeu100105110GluGluThrTyrIleAlaThrIleLeuArgGluIleLeuLysGlyLeu115120125AspTyrLeuHisSerGluArgLysIleHisArgAspIleLysAlaAla130135140AsnValLeuLeuSerGluGlnGlyAspValLysLeuAlaAspPheGly145150155160ValAlaGlyGlnLeuThrAspThrGlnIleLysArgAsnThrPheVal165170175GlyThrProPheTrpMetAlaProGluValIleLysGlnSerAlaTyr180185190AspPheLysAlaAspIleTrpSerLeuGlyIleThrAlaIleGluLeu195200205AlaLysGlyGluProProAsnSerAspLeuHisProMetArgValLeu210215220PheLeuIleProLysAsnSerProProThrLeuGluGlyGlnHisSer225230235240LysProPheLysGluPheValGluAlaCysLeuAsnLysAspProArg245250255PheArgProThrAlaLysGluLeuLeuLysHisLysPheIleThrArg260265270TyrThrLysLysThrSerPheLeuThrGluLeuIleAspArgTyrLys275280285ArgTrpLysSerGluGlyHisGlyGluGluSerSerSerGluAspSer290295300AspIleAspGlyGluAlaGluAspGlyGluGlnGlyProIleTrpThr305310315320PheProProThrIleArgProSerProHisSerLysLeuHisLysGly325330335ThrAlaLeuHisSerSerGlnLysProAlaAspAlaValLysArgGln340345350ProArgSerGlnCysLeuSerThrLeuValArgProValPheGlyGlu355360365LeuLysGluLysHisLysGlnSerGlyGlySerValGlyAlaLeuGlu370375380GluLeuGluAsnAlaPheSerLeuAlaGluGluSerCysProGlyIle385390395400SerAspLysLeuMetValHisLeuValGluArgValGlnArgPheSer405410415HisAsnArgAsnHisLeuThrSerThrArg420425(2) INFORMATION FOR SEQ ID NO:3:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 268 amino acids(B) TYPE: amino acid(D) TOPOLOGY: linear(ii) MOLECULE TYPE: protein(xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:ProLysLysLysTyrThrArgPheGluLysIleGlyGlnGlyAlaSer151015GlyThrValTyrThrAlaMetAspValAlaThrGlyGlnGluValAla202530IleLysGlnMetAsnLeuGlnGlnGlnProLysLysGluLeuIleIle354045AsnGluIleLeuValMetArgGluAsnLysAsnProAsnIleValAsn505560TyrLeuAspSerTyrLeuValGlyAspGluLeuTrpValValMetGlu65707580TyrLeuAlaGlyGlySerLeuThrAspValValThrGluThrCysMet859095AspGluGlyGlnIleAlaAlaValCysArgGluCysLeuGlnAlaLeu100105110GluPheLeuHisSerAsnGlnValIleHisArgAspIleLysSerAsp115120125AsnIleLeuLeuGlyMetAspGlySerValLysLeuThrAspPheGly130135140PheCysAlaGlnIleThrProGluGlnSerLysArgSerThrMetVal145150155160GlyThrProTyrTrpMetAlaProGluValValThrArgLysAlaTyr165170175GlyProLysValAspIleTrpSerLeuGlyIleMetAlaIleGluMet180185190IleGluGlyGluProProTyrLeuAsnGluAsnProLeuArgAlaLeu195200205TyrLeuIleAlaThrAsnGlyThrProGluLeuGlnAsnProGluLys210215220LeuSerAlaIlePheArgAspPheLeuAsnArgCysLeuGluMetAsp225230235240ValGluLysArgGlySerAlaLysGluLeuLeuGlnHisGlnPheLeu245250255LysIleAlaLysProLeuSerSerLeuThrProLeu260265(2) INFORMATION FOR SEQ ID NO:4:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 271 amino acids(B) TYPE: amino acid(D) TOPOLOGY: linear(ii) MOLECULE TYPE: protein(xi) SEQUENCE DESCRIPTION: SEQ ID NO:4:ProSerThrLysTyrAlaAsnLeuValLysIleGlyGlnGlyAlaSer151015GlyGlyValTyrThrAlaTyrGluIleGlyThrAsnValSerValAla202530IleLysGlnMetAsnLeuGluLysGlnProLysLysGluLeuIleIle354045AsnGluIleLeuValMetLysGlySerLysHisProAsnIleValAsn505560PheIleAspSerTyrValLeuLysGlyAspLeuTrpValIleMetGlu65707580TyrMetGluGlyGlySerLeuThrAspValValThrHisCysIleLeu859095ThrGluGlyGlnIleGlyAlaValCysArgGluThrLeuSerGlyLeu100105110GluPheLeuHisSerLysGlyValLeuHisArgAspIleLysSerAsp115120125AsnIleLeuLeuSerMetGluGlyAspIleLysLeuThrAspPheGly130135140PheCysAlaGlnIleAsnGluLeuAsnIleLysArgThrThrMetVal145150155160GlyThrProTyrTrpMetAlaProGluValValSerArgLysGluTyr165170175GlyProLysValAspIleTrpSerLeuGlyIleMetIleIleGluMet180185190IleGluGlyGluProProTyrLeuAsnGluThrProLeuArgAlaLeu195200205TyrLeuIleAlaThrAsnGlyThrProLysLeuLysGluProGluAsn210215220LeuSerSerSerLeuLysLysPheLeuAspTrpCysLeuCysValGlu225230235240ProGluAspArgAlaSerAlaThrGluLeuLeuHisAspGluTyrIle245250255ThrGluIleAlaGluAlaAsnSerSerLeuAlaProLeuValLys260265270(2) INFORMATION FOR SEQ ID NO:5:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 270 amino acids(B) TYPE: amino acid(D) TOPOLOGY: linear(ii) MOLECULE TYPE: protein(xi) SEQUENCE DESCRIPTION: SEQ ID NO:5:ProGluGluValPheAspValLeuGluLysLeuGlyGluGlySerTyr151015GlySerValTyrLysAlaIleHisLysGluThrGlyGlnIleValAla202530IleLysGlnValAsxValGluSerAspLeuGlnGluIleIleLysGlu354045IleSerIleMetGlnGlnCysAspSerProHisValValLysTyrTyr505560GlySerTyrPheLysAsnThrAspLeuTrpIleValMetGluTyrCys65707580GlyAlaGlySerValSerAspIleIleArgLeuArgAsnLysThrLeu859095ThrGluAspGluIleAlaThrIleLeuGlnSerThrLeuLysGlyLeu100105110GluTyrLeuHisPheMetArgLysIleHisArgAspIleLysAlaGly115120125AsnIleLeuLeuAsnThrGluGlyHisAlaLysLeuAlaAspPheGly130135140ValAlaGlyGlnLeuThrAspThrMetAlaLysArgAsnThrValIle145150155160GlyThrProPheTrpMetAlaProGluValIleGlnGluIleGlyTyr165170175AsnCysValAlaAspIleTrpSerLeuGlyIleThrAlaIleGluMet180185190AlaGluGlyLysArgProTyrAlaAspIleHisProMetArgAlaIle195200205PheMetIleProThrAsnProProProThrPheArgLysProGluLeu210215220TrpSerAspAsnPheThrAspPheValLysGlnCysLeuValLysSer225230235240ProGluGlnArgAlaThrAlaThrGlnLeuLeuGlnHisProPheVal245250255ArgSerAlaLysGlyValSerIleLeuArgAspLeuIleAsn260265270(2) INFORMATION FOR SEQ ID NO:6:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 272 amino acids(B) TYPE: amino acid(D) TOPOLOGY: linear(ii) MOLECULE TYPE: protein(xi) SEQUENCE DESCRIPTION: SEQ ID NO:6:ProSerLysLeuTyrSerIleGlnSerCysIleGlyArgGlyAsnPhe151015GlyAspValTyrLysAlaValAspArgValThrGlnGluIleValAla202530IleLysValValAsnLeuGluHisSerAspGluAspIleGluLeuLeu354045AlaGlnGluIlePhePheLeuAlaGluLeuLysSerProLeuIleThr505560AsnTyrIleAlaThrMetLeuGluAspValSerMetTrpIleValMet65707580GluTyrCysGlyGlyGlySerCysSerAspLeuLeuLysArgSerTyr859095ValAsnGlyLeuProGluGluLysValSerPheIleIleHisGluVal100105110ThrLeuGlyLeuLysTyrLeuHisGluGlnArgLysIleHisArgAsp115120125IleLysAlaAlaAsnIleLeuIleAsnGluGluGlyMetValLysLeu130135140GlyAspPheGlyValSerGlyHisIleArgSerThrLeuLysArgAsp145150155160ThrPheValGlyThrProTyrTrpMetAlaProGluValValCysCys165170175GluValAspGlyTyrAsnGluLysAlaAspIleTrpSerLeuGlyIle180185190ThrThrTyrGluLeuLeuLysGlyLeuProProLeuSerLysTyrAsp195200205ProMetLysValMetThrAsnLeuProLysArgLysProProLysLeu210215220GlnGlyProPheSerAspAlaAlaLysAspPheValAlaGlyCysLeu225230235240ValLysThrProAlaAspArgProSerAlaTyrAsnLeuLeuSerPhe245250255GluPheValLysAsnIleThrIleThrAsnLeuLysSerAspValAsp260265270(2) INFORMATION FOR SEQ ID NO:7:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 276 amino acids(B) TYPE: amino acid(D) TOPOLOGY: linear(ii) MOLECULE TYPE: protein(xi) SEQUENCE DESCRIPTION: SEQ ID NO:7:ProArgAspArgPheGluLeuLeuGlnArgValGlyAlaGlyThrTyr151015GlyAspValTyrLysAlaArgAspThrValThrSerGluLeuAlaAla202530ValLysIleValLysLeuAspProGlyAspAspIleSerSerLeuGln354045GlnGluIleThrIleLeuArgGluCysArgHisProAsnValValAla505560TyrIleGlySerTyrLeuArgAsnAspArgIleTrpIleCysMetGlu65707580PheCysGlyGlyGlySerLeuGlnGluIleTyrHisAlaThrGlyPro859095LeuGluGluArgGlnIleAlaTyrValCysArgGluArgLeuLysGly100105110LeuHisHisLeuHisSerGlnGlyLysIleHisArgAspIleLysGly115120125AlaAsnLeuLeuLeuThrLeuGlnGlyAspValLysLeuAlaAspPhe130135140GlyValSerGlyGluLeuThrAlaSerValAlaLysArgArgSerPhe145150155160IleGlyThrProTyrTrpMetAlaProGluValAlaAlaValGluArg165170175LysGlyGlyTyrAsnGluLeuCysAspValTrpAlaLeuGlyIleThr180185190AlaIleGluLeuGlyGluLeuGlnProProLeuPheHisLeuHisPro195200205MetArgAlaLeuMetLeuMetSerLysSerSerPheGlnProProLys210215220LeuArgAspLysThrArgTrpThrGlnAsnPheHisHisPheLeuLys225230235240LeuAlaLeuThrLysAsnProLysLysArgProThrAlaGluLysLeu245250255LeuGlnHisProPheThrThrGlnGlnLeuProArgAlaLeuLeuThr260265270GlnLeuLeuAsp275(2) INFORMATION FOR SEQ ID NO:8:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 20 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: Degenerate primer(ix) FEATURE:(B) LOCATION: 3...3(D) OTHER INFORMATION: where R at position 3 is A or G(B) LOCATION: 4...4(D) OTHER INFORMATION: where Y at position 4 is C or T,but not U(B) LOCATION: 6...6(D) OTHER INFORMATION: where N at position 6 is Inosine(B) LOCATION: 12...12(D) OTHER INFORMATION: where N at position 12 is Inosine(B) LOCATION: 15...15(D) OTHER INFORMATION: where N at position 15 is Inosine(B) LOCATION: 18...18(D) OTHER INFORMATION: where R at position 18 is A or G(xi) SEQUENCE DESCRIPTION: SEQ ID NO:8:GARYTNATGGCNGTNAARCA20(2) INFORMATION FOR SEQ ID NO:9:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 23 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: Degenerate primer(ix) FEATURE:(B) LOCATION: 3...3(D) OTHER INFORMATION: where N at position 3 is Inosine(B) LOCATION: 6...6(D) OTHER INFORMATION: where N at position 6 is Inosine(B) LOCATION: 9...9(D) OTHER INFORMATION: where Y at position 9 is C or T,but not U(B) LOCATION: 12...12(D) OTHER INFORMATION: where N at position 12 is Inosine(B) LOCATION: 15...15(D) OTHER INFORMATION: where R at position 15 is A or G(B) LOCATION: 18...18(D) OTHER INFORMATION: where N at position 18 is Inosine(B) LOCATION: 20...20(D) OTHER INFORMATION: where K at position 20 is G or T,but not U(B) LOCATION: 21...21(D) OTHER INFORMATION: where R at position 21 is A or G(xi) SEQUENCE DESCRIPTION: SEQ ID NO:9:TTNGCNCCYTTNATRTCNCKRTG23(2) INFORMATION FOR SEQ ID NO:10:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 10 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: Kozak sequence(xi) SEQUENCE DESCRIPTION: SEQ ID NO:10:GCGGCCATGG10__________________________________________________________________________ | A SOK polypeptide, an isolated DNA having a nucleotide sequence encoding a SOK polypeptide, and a method of determining whether a candidate compound modulates SOK-1 activity or expression, comprising the steps of providing a first and a second recombinant cell expressing a SOK gene; introducing a candidate compound into the first cell, but not into the second cell; measuring a SOK function in the first and second cells; and comparing the results obtained with the first and second SOK transformed cells, wherein an increase or decrease in the SOK function in the first cell compared to the second cell is an indication that the candidate compound modulates SOK expression or activity. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to wooden studs for construction purposes and, more specifically, to methods for manufacturing studs.
BACKGROUND OF THE INVENTION
[0002] Wood frame construction is a very common type of building construction technology used today. In the continual quest to reduce the cost of construction and to increase the productivity of the construction labor force, attention is given to reducing the cost of material, reducing the labor required for construction, and increasing the quality of the material used.
[0003] One nearly ubiquitous structural element used in wood construction is a piece of lumber called a stud. Studs are the vertical, load-bearing pieces of wood in the interior or exterior walls of a building to which sheathing or panel material is attached to form the wall structures. In addition to their use in wall construction, studs are also used in other parts of the framing process. There is a need to provide a reliable, low-cost supply of high-quality wooden studs for the construction industry.
[0004] The traditional stud is made in one piece and cut from tall trees, into 1½ inch by 3½ inch cross-sections (the standard 2×4), or 1½ inch by 5½ inch cross-sections (the standard 2×6), and milled into various lengths—most typically 8 or 9 feet. Such studs are often subject to warping, both bending and twisting.
[0005] Among the many factors which contribute to the cost and quality of wooden studs are the following: (1) the cost of the raw material used, affected by the amount and quality of timber available and the demand for timber; (2) the cost of manufacture of the studs; (3) the cost of transportation, which, among other things, is dependent on the weight of the studs; (4) the resistance to warpage of the studs, which reduces waste and increases the quality of the resulting structures; and (5) ease of use of the studs, affected by weight and by the extent of warpage. Thus, the need for a reliable, low-cost supply of high-quality wooden studs can be translated into a need for straight, stable, lightweight studs made from a source of inexpensive raw material.
[0006] One source of inexpensive raw material used in the construction industry is oriented strand board (OSB), a dimensionally-stable engineered wood sheet product which utilizes the fiber available from “waste” trees which are too small to produce traditional solid-wood products such as studs. The raw material for OSB itself, therefore, is inexpensive, and the manufacturing process is highly automated, making OSB an excellent, cost-effective source of raw material for fabricated lumber.
[0007] OSB has been used in the past as part of fabricated structural members for applications such as trusses, joists, rafters, and girders, i.e., in applications in which it is necessary for a horizontal structural member to carry vertical loads across the horizontal span of the structural member. Such beams, typically in I-beam or box-beam configurations, were structures to which engineered sheet materials could be applied because of the fact that I-beam and box-beam cross-sections are efficient in withstanding the tensile and compressive loads present in such applications, not to mention the fact that timber for long-span structural members is often not readily available.
[0008] However, the concept of engineered structures and in particular hollow box structures has not been widely accepted with respect to studs, i.e., 2×4 and 2×6 structures for use as studs in supporting interior and exterior walls. There are several reasons for this. First, it tends to be counterintuitive to make wooden studs hollow since studs are relatively slender. Second, since studs are designed to receive and to secure fasteners such as nails, it is thought that a hollow stud would not secure the appropriate fasteners as readily as solid wood. Third, studs are sized for placement in vertical, upright positions where they carry mainly compressive forces. Thus, box-shaped designs have not typically been associated with wooden studs.
[0009] In the past, there have been a number of efforts directed to the manufacture of engineered wooden beams, primarily for horizontal beam applications, with very little effort of practical consequence being applied with respect to the manufacture of studs intended primarily to take compressive loads. In fact, essentially no engineered wooden studs, whether or not made primarily of OSB, are available in normal market channels. Furthermore, the configuration of fabricated beam structures and other structures that may be seen in prior art documents are quite complex, and thus would typically be relatively expensive to manufacture.
[0010] There has been a need for a simple, low-cost, stable compressive-load-bearing wooden stud which can be easily manufactured and easily used.
OBJECTS OF THE INVENTION
[0011] Accordingly, it is a principal object of the invention to provide a fabricated wooden stud made primarily of OSB, thereby using wood sources not able to be used for solid timber studs.
[0012] A more specific object of the invention to provide a manufacturing method for a fabricated wooden stud made primarily of OSB.
[0013] It is another object of the invention to provide an improved stud which can be produced at a minimum cost.
[0014] It is object of the invention to provide an efficient manufacturing method for a fabricated wooden stud.
[0015] Another object of this invention is to provide an improved wooden stud having high structural strength without using solid timber.
[0016] Another object of this invention is to provide an improved stud that is not subject to the warping that is often typical of traditional construction lumber.
[0017] Another object of this invention is to provide a manufacturing method which utilizes standard sheets of OSB to construct fabricated wooden studs.
[0018] Another object of this invention is to provide a stud that has lower weight, thereby lowering transportation costs and facilitating use on construction sites.
[0019] Yet another object of this invention is to provide a fabricated stud which has the ability to receive framing nails and other fasteners used in wooden building construction.
[0020] Another object of this invention is to provide a manufacturing method for fabricated wooden studs which is highly automated, requiring a minimal amount of manual intervention.
[0021] These and other objects of the invention will be apparent from the following descriptions and from the drawings.
SUMMARY OF THE INVENTION
[0022] The instant invention is a method for fabricating wooden studs, each of which, broadly described, has the following characteristics: (1) a pair of fully-aligned face-members of OSB spaced from one another and each having first and second ends and first and second elongate edges; (2) first and second fully-aligned edge-members of OSB spaced from one another, the first and second edge-members being adhesively affixed between the face-members along the first edges and second edges thereof, respectively; and (3) a pair of end-members adhesively affixed between the face-members at the ends thereof. Such fabricated wooden stud, preferably made using the method of this invention, is the subject of a concurrently filed patent application, Ser. No. ______, of the same inventor, entitled “Fabricated OSB Stud.”
[0023] The manufacturing method of this invention overcomes the above-noted problems and shortcomings, satisfies the objects of the invention, and produces highly desirable fabricated wooden studs. In describing the method of this invention, certain terminology is used which is defined at the end of this summary section.
[0024] The method for manufacturing fabricated wooden studs includes: (1) providing a supply of face-sheets of OSB, the face-sheets having opposite ends; (2) providing a supply of edge-strips of OSB; (3) providing a supply of end-members; (4) placing a first one of the face-sheets on an assembly base; (5) placing a plurality of edge-strips onto the first face-sheet, with the edge-strips positioned in spaced, parallel relationship to one another; (6) placing a plurality of end-members on the first face-sheet at the opposite ends and between adjacent edge-strips; (7) placing a second of the face-sheets onto all of the placed edge strips and placed end-members to sandwich such edge-strips and end-members between the first and second face-sheets; (8) applying adhesive between the layers at any time during the placing steps, thereby to form a three-layer assembly; (9) pressing the three-layer assembly until the adhesive is set to produce a stud assembly; and (10) cutting the stud assembly along lines which divide the edge-strips to form a plurality of studs.
[0025] In a preferred embodiment of the invention, the method further includes providing a supply of inner-sheets of OSB and cutting the inner-sheets of OSB to create the supply of edge-strips.
[0026] In another preferred embodiment of the inventive method, providing the supply of end-members includes cutting the end-members from at least one of the inner-sheets.
[0027] In certain preferred embodiments of the invention, the method further includes the steps of (1) providing a supply of core-members; (2) placing a plurality of core-members onto the first face-sheet between the adjacent edge-strips; and (3) applying adhesive to the plurality of core-members. In some other preferred embodiments, a plurality of core-members are placed in spaced relationship with each other between each adjacent pair of the edge-strips.
[0028] Other preferred embodiments of the inventive method include the steps of (1) cutting wiring pass-throughs in the first and second face-sheets; and (2) cutting wiring pass-throughs in the core-members.
[0029] In a highly preferred embodiment of the invention, the end-members and the core-members are cut from the supply of inner-sheets of OSB. In such embodiments, wiring pass-throughs are cut in the inner-sheets at locations from which the core-members are cut.
[0030] In another highly preferred embodiment of the inventive manufacturing method, the pressing step includes pressing a stacked plurality of three-layer assemblies.
[0031] Additionally, highly preferred embodiments of the method include trimming the ends of the stud assembly prior to cutting the stud assembly into a plurality of studs.
[0032] The intended meanings of various terms used in this document are set forth in the paragraphs which follow:
[0033] The term “face-member” as used herein refers to each of the two wider elongate pieces which, in preferred embodiments of this invention, form all of the wide sides of the stud. In similar fashion, the term “edge-member” as used herein refers to each of the two narrower pieces which, in preferred embodiments of this invention, form part of the narrow sides of the stud.
[0034] The term “fully-aligned” is used herein with respect to the two face-members or with respect to the two edge-members. The term describes two members as being sized and oriented with respect to each other in certain ways, namely: (1) the two members have substantially equal dimensions of length, width, and thickness; (2) the length directions of the two members are substantially parallel; and (3) perpendicular projections of the two members onto a plane that is perpendicular to either the thickness or width directions of the members (but not both) are fully overlapping.
[0035] The term “end-member” as used herein refers to the two pieces each of which occupies the space inside the stud at an end thereof, such space being formed between the two face-members and the two edge-members.
[0036] The term “core-member” as used herein refers to each piece which is similar to an end-member but which occupies a space inside the stud at a selected location away from the ends of the stud, such spaces being formed by the two face-members and the two edge-members.
[0037] The term “OSB plane” as used herein with respect to a particular OSB member refers, to the plane of the top surface of the sheet of OSB from which the particular member has been cut. For example, if several sheets of OSB material are layered one on top of another, their OSB planes are parallel regardless of the width and length directions of the OSB sheets from which they have been cut.
[0038] The term “face-sheet” as used herein with respect to a method of manufacture, refers to each of the top and bottom OSB layers of the stud assembly.
[0039] The term “edge-strip” as used herein with respect to a method of manufacture, refers to each of the plurality of elongate OSB pieces which are part of the stud assembly and which, when the stud assembly is cut into a plurality of studs, form the edge-members of the studs.
[0040] The term “inner sheet” as used herein with respect to a method of manufacture, refers to the sheets of OSB from which edge-strips, end-members, and core-members are cut.
[0041] The term “stud assembly” as used herein with respect to a method of manufacture, refers to the three-layer sandwich which includes first and second face-sheets with a plurality of edge-strips, end-members, and core-members arranged in accordance with a plan accommodating the stud configuration and the subsequent cutting of the sandwich into a plurality of studs. (See FIG. 3, referred to below.) The term “assembly base” as used herein refers to a preferably horizontal work surface on which the face-sheets and the various members to be sandwiched therebetween are laid up during the stud fabrication process.
[0042] The words “the entire stud is made of OSB” should be understood to allow the use of adhesive to bond the various parts of the fabricated stud together and also to include the optional use of various coatings on the studs, such as a water-repellant coating over the edges of the OSB material.
[0043] The term “broken corners” as used herein with respect to a stud refers to the outer corners along the length of the stud as having been trimmed to have a small radius or slightly beveled character in order to eliminate sharp corners.
[0044] The term “wiring pass-throughs” as used herein refers to holes through the smallest dimension of the stud to allow electrical wiring to be installed easily in walls constructed with such fabricated wooden studs. Wiring pass-throughs in a series of studs forming a wall allow rapid wiring on the job site. The term is used herein to refer both to holes in individual members of the stud (during manufacturing) as well as to holes through the finished stud.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] [0045]FIG. 1 is a partial perspective drawing of an end portion of the fabricated wooden stud.
[0046] [0046]FIG. 2 a , 2 b , and 2 c are the three orthographic views of the fabricated wooden stud, with the stud broken at a point along the length of the stud in order to show both ends of the stud. FIG. 2 a is the face view; FIG. 2 b is the edge view; and FIG. 2 c is the end view.
[0047] [0047]FIG. 3 is a cutaway schematic which illustrates a simple approach to manufacturing the fabricated wooden stud.
[0048] [0048]FIGS. 4 a and 4 b are partial end-view schematics of one corner of the fabricated wooden stud.
[0049] [0049]FIG. 5 is a partial cutaway perspective drawing of a end portion of an embodiment of the fabricated wooden stud which includes insulation in the void space which is formed by the spaced face-members and the spaced edge-members.
[0050] [0050]FIGS. 6 a and 6 b are schematic diagrams of a preferred embodiment of a production line which utilizes the inventive method claimed herein to manufacture fabricated OSB studs.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0051] [0051]FIGS. 1 through 5 assist in description of a preferred embodiment of the fabricated wooden stud produced by the inventive manufacturing method. FIG. 1 shows a perspective drawing of an end portion of fabricated wooden stud 10 , illustrating the general configuration of the stud.
[0052] [0052]FIGS. 2 a - 2 c , which are a set of orthographic views of the fabricated wooden stud, illustrate more clearly the complete structure of a highly preferred embodiment of stud 10 . Edge-members 22 are sandwiched between and adhesively bonded to two face-members 20 . A pair of end-members 24 are also sandwiched between and adhesively bonded to two face-members 20 . Face-members 20 are fully-aligned, as are edge-members 22 . Edge-members 22 are positioned such that elongate outer surfaces 50 and 51 of edge-members 22 are coplanar with first elongate edges 40 and second elongate edges 42 of face-members 20 , respectively. The width of face-members 20 is equal to the full width of stud 10 . In addition, end surfaces 30 and 32 of end-members 24 are flush with first end 31 and second end 33 of face-members 20 , respectively.
[0053] [0053]FIGS. 2 a and 2 c show one core-member 26 also sandwiched between and adhesively bonded to face-members 20 , positioned at a point along the length of stud 10 , away from the ends, thereby dividing the void which is formed by the spaced face-members 20 and the spaced edge-members 22 .
[0054] Referring again to FIG. 1, OSB planes of the various members are indicated by two coordinate axes referenced to the individual members. OSB planes 60 and 62 of face-members 20 , OSB plane 61 of edge-members 22 , end-members 24 , and core-members 26 (not shown in FIG. 1) are all substantially parallel. No OSB planes are illustrated in FIGS. 2 a - 2 c , but in FIG. 2 a , OSB planes 60 , 61 , and 62 would all be parallel to the surface on which the figure is drawn.
[0055] Fabricated wooden stud 10 can be manufactured in a simple and cost-effective manner by a batch process. FIG. 3 illustrates such an approach with a cutaway sketch of a three-layer stud assembly 300 of OSB material.
[0056] Stud assembly 300 , from which studs are cut, is created by arranging edge-strips 101 of OSB (two are labeled but more than two are shown) on OSB face-sheet 100 . Spaces 106 (two are labeled but more than two are shown) between edge-strips 101 are the voids formed by spaced edge-strips 101 and spaced face-sheets 100 and 102 . End-members 24 (two are labeled but more than two are shown) and core-members 26 (two are labeled and shown) are placed at the ends and in spaces 106 between edge-strips 101 as appropriate. Prior to assembly of stud assembly 300 , edge-strips 101 , end-members 24 , and core-members 26 are cut from one or more inner-sheets in a batch process preparatory to the assembly process. Edge-strips 101 , end-members 24 , and core-members 26 are all of equal thickness and in a single layer, in a common plane. OSB face-sheet 102 is placed on top of this second layer, becoming the third layer and completing stud assembly 300 . The OSB planes of all pieces forming stud assembly 300 are parallel.
[0057] During the assembly process, adhesive is applied to all the appropriate surfaces (i.e., at least on adjoining surfaces parallel to the OSB planes) in order to affix together the various members of stud assembly 300 . Stud assembly 300 is then pressed together until the adhesive bonding is secure.
[0058] Acceptable adhesives include adhesives used in the manufacture of OSB, plywood and other engineered lumber. For example, Mira-Lok-#1077 adhesive manufactured by The Huntsman Polyurethanes is an excellent adhesive for this purpose.
[0059] Sawcuts are then made along sawcut lines 80 (two are labeled but more than two are shown) to produce the individual studs. As a result of these sawcuts, portions of edge-strips 101 become edge-members of adjacently-formed studs, and portions of face-sheets 100 and 102 become face-members 20 of adjacently-formed studs.
[0060] The size of typical studs for the building industry varies, with 2×4 (1½″ by 3½″) and 2×6 (1½″ by 5½″) studs being the most common sizes. The fabricated wooden stud disclosed herein, in standard 8-foot lengths, has a weight which is about 18-20% less than standard studs, using two end-members and a single core-member, each of which are 4 inches long. For further cost savings, the thickness of the stud can be reduced to 1⅜″, with the face-members made of {fraction (7/16)}″-thick OSB and the edge-members, end-members, and core-members made of ½″-thick OSB. These typical dimensions are not intended to limit the possible dimensions for the fabricated wooden stud disclosed herein.
[0061] In a highly preferred embodiment of the fabricated wooden stud, the corners of the elongated edges may be broken corners to enhance the safe handling of the stud during use. FIGS. 4 a and 4 b , both partial end-view schematics of a fabricated wooden stud, illustrate two embodiments of broken corners. FIG. 4 a shows beveled corner 90 , and FIG. 4 b shows corner 91 cut with a radius.
[0062] Further, the exposed edges of OSB can be coated with a water-resistant coating to protect the OSB prior to installation of the studs into a building structure.
[0063] Voids 106 which are formed in the interior of the studs, in a common embodiment, are filled with air, forming dead-air spaces which have excellent insulating characteristics. In other embodiments of the inventive stud, voids 106 are filled with other insulating materials which have even better insulating properties than dead air. Such materials include various polymer foams and fiber materials such as fiberglass. FIG. 5 is a partial cutaway perspective drawing of an end portion of an embodiment of fabricated wooden stud 10 which includes insulation 110 in void 106 which is formed by spaced face-members 20 and spaced edge-members 22 .
[0064] A number of variations in the exact form of the fabricated wooden stud are possible, although these are not shown in the figures. For example, the elongate outer surfaces of the edge-members can be inset from the elongate edges of the face-members. In a similar fashion, the end surfaces of the end-members can be inset from the ends of the stud. There may also be situations in which it is desirable to fabricate a wooden stud in which the OSB planes of the edge-members are not substantially parallel to the OSB planes of the face-members.
[0065] Another embodiment of the fabricated wooden stud may include end-members and/or core-members which are not made of OSB but of solid wood or another form of fabricated board such as plywood, particle board or medium density fiberboard (MDF).
[0066] Another embodiment of the fabricated wooden stud may incorporate end-members in which the end surfaces of the end members extend beyond the ends of the face-members.
[0067] [0067]FIG. 6 a is a schematic of a preferred embodiment of a portion of a production line 200 a configured to perform the method of this invention. The method is carried out in a batch process, whereby segments 200 a and 200 b of a production line 200 are used for more than one step of the inventive method, as described in the following paragraphs.
[0068] The first part of the batch process includes providing a supply of edge-strips 101 , end-members 24 , and core-members 26 shown in FIG. 3. Referring to FIG. 6 a , inner sheets are placed on a feeder infeed 210 which supplies inner sheets one at a time to a feeder 212 . Feeder 212 feeds inner sheets onto an alignment conveyor 214 which then moves the inner sheets through knockout machines 216 which cut wiring pass-throughs at the locations on the inner sheets which will later be cut into core-members. (Two knockout machines 216 are shown, representing the option that more than one pattern of wiring pass-throughs may be cut with this arrangement of equipment in production line 200 .) Inner sheets are then stacked on a feeder 218 and moved by a forklift to an infeed table 220 . A plurality of inner sheets are moved onto a platform 222 and pushed onto a saw platform 224 by a pusher 226 . Pusher 226 incrementally indexes the plurality of inner sheets to various positions on platform 224 , enabling a saw 228 to cut edge-strips 101 , end-members 24 , and core-members 26 from the plurality of inner sheets. Edge-strips 101 , end-members 24 , and core-members 26 are stacked (manually in this embodiment) in infeed magazines 230 , ready to be placed in stud assemblies during the next portion of the batch process.
[0069] Feeder 218 , using vacuum to hold sheet material, collects in sequence first face-sheet 100 , arranged edge-strips 101 , end-members 24 , and core-members 26 (arranged as shown in FIG. 3), and second face-sheet 102 and places them on lay-up lift 232 . Lay-up lift 232 provides an assembly base for initial lay-up of stud assemblies (defined above). Edge-strips 101 , end-members 24 , and core-members 26 are collected from magazines (not shown) movably supported on a magazine conveyor 230 . The magazines are positioned in line with the movement of feeder 218 on a magazine conveyor 230 a . As first face-sheet 100 , arranged edge-strips 101 , end-members 24 , and core-members 26 , and second face-sheets 102 are stacked onto a lay-up lift 232 , an adhesive dispenser 234 moves over and dispenses adhesive onto the upper surface of first face-sheet 100 onto which edge-strips 101 , end-members 24 , and core-members 26 are placed and then dispenses adhesive onto edge-strips 101 , end-members 24 , and core-members 26 , onto which second face-sheet 102 is placed. This three-layer assembly is repeated on lay-up lift 232 until ten three-layer assemblies are stacked together on lay-up lift 232 . Lay-up lift 232 , itself or with one or more three-layer assemblies on it, provides what is referred to herein as the assembly base.
[0070] When ten three-layer assemblies are stacked on lay-up lift 232 , a transfer unit 236 moves the stack onto rollers 238 which are arranged in line with presses 240 a and 240 b . Transfer units 242 a and 242 b move the stack of three-layer assemblies into presses 240 a or 240 b respectively, depending on which press is available for use. The press cycle time, during which pressure is applied to the stack, is twice the length of time it takes to assemble the stack of ten three-layer assemblies. After pressing is complete, outfeed rollers 244 a and 244 b are used to transfer stacks out of presses 240 a and 240 b respectively. Stacks of three-layer assemblies, now referred to as stud assemblies, are removed from outfeed rollers 244 a and 244 b by a forklift truck.
[0071] [0071]FIG. 6 b is a schematic of a preferred embodiment of an additional portion of a production line 200 b configured to perform the method of this invention. Referring to FIG. 6 b , after a stack of three-layer assemblies is taken from outfeed rollers 244 a or 244 b (shown in FIG. 6 a ), the stack is fed into a feeder 246 . Feeder 246 feeds stud assemblies one at a time into a corner transfer unit 248 which aligns the stud assembly with a trim saw 250 . Trim saw 250 trims a minimal amount of material from each end of the stud assembly. The trimmed stud assembly is moved onto a rip infeed conveyor 252 which aligns the trimmed stud assembly against a side alignment fence (not shown) and moves the trimmed stud assembly into a rip saw 254 . Rip saw 254 cuts the trimmed stud assembly into multiple studs of final stud width.
[0072] After the studs are ripped from the trimmed stud assembly, and before the studs are coated with sealant at a coater 262 , it is preferred that the outer corners along the length of the studs be trimmed to have broken corners, i.e., corners having a small radius or slightly beveled character. This can be done for all four corners in a single pass through a device such as a multi-surface sander (not shown).
[0073] An outfeed conveyor 256 and a singulation conveyor 258 transfer the individual studs to an coater infeed 260 which in turn drives the individual studs through a coater 262 . Coater 262 places a sealant on the two elongate edges of the studs.
[0074] Final marking, strapping, and stacking of the studs is done on various pieces of production line conveyance and handling equipment well-known to those skilled in the art of lumber production and labeled as 270 in FIG. 6 b. | A method for manufacturing fabricated wooden studs including: providing (a) face-sheets of OSB, the face-sheets having opposite ends, (b) edge-strips of OSB, and (c) end-members; placing a first one of the face-sheets on an assembly base; placing a plurality of edge-strips onto the first face-sheet, the edge-strips being in spaced, parallel relationship to one another; placing a plurality of end-members on the first face-sheet at the opposite ends and between adjacent edge-strips; placing a second of the face-sheets onto all of the placed edge strips and placed end-members to sandwich such edge-strips and end-members between the first and second face-sheets; applying adhesive between the layers at any time during the placing steps, thereby to form a three-layer assembly; pressing the three-layer assembly until the adhesive is set to produce a stud assembly; and cutting the stud assembly along lines which divide the edge-strips to form a plurality of studs. | 4 |
The present invention relates generally to an antenna assembly and specifically to an antenna assembly that provides vertical antenna polarization for use with a mobile computing device or the like.
BACKGROUND OF THE INVENTION
Polarization of an antenna refers to the orientation of an electric field of its radio wave with respect to the earth's surface and is determined by the physical structure of the antenna and by its orientation. Thus, a simple straight wire antenna will have one polarization when mounted vertically, and a different polarization when mounted horizontally.
Polarization is largely predictable from antenna construction. For radio antennas, polarization corresponds to the orientation of the radiating element in an antenna. For a linearly polarized antenna, a vertically positioned antenna will result in vertical polarization. Similarly a horizontally positioned antenna will result in horizontal polarization.
In practice, it is preferable that the orientation of linearly polarized antennas on a transmitter are matched with the orientation of the linearly polarized antennas on a receiver, or else the strength of a signal received at the receiver will be reduced. That is, vertically polarized antennas on a transmitting device are preferably used with vertically polarized antennas on a receiving device and horizontally polarized antennas on a transmitting device are preferably used with horizontally polarized antennas on a receiving device. Intermediate matchings between transmitter antenna and receiver antenna will result in a loss of some received signal strength, but not as much as would result in the case of a complete mismatch between antenna polarizations.
The most common and cost effective method for providing circular coverage area around a base-station antenna is to install an omni-directional antenna pointed upward, perpendicular to the earth. This forces vertical polarization and provides a pattern that is omni-directional in azimuth. Such an antenna position is used in many radio communication schemes such as wireless phone networks, mobile ultra high frequency (UHF) radio such as Citizen's Band (CB) radio, Wi-Fi™ and the like. If the same antenna is mounted parallel to the earth then it will yield horizontal polarization. As a result, the pattern is no longer omni-directional but a “figure 8”. That is, for example, if the tip of the antenna is at 0°, then you will have maximum radiation 90° and 270°, but little radiation at 0° and 180° deg. If there is a need to provide omni-directional coverage with horizontal polarization then the most common method is to use three sector antennas, each designed for horizontal polarization. As a result, it is more expensive and complex to implement an omni-directional horizontally polarized antenna because there are three antennas, a three-way splitter, and three more cables.
Thus, many radio transceivers such as base-stations, for example, are configured with vertically polarized antennas. Accordingly, it is preferable to provide vertically polarized antennas in the transmitting devices in communication with the base-stations. However, due to size limitations, antennas in some mobile communication devices are configured in a horizontal position and, thus, are horizontally polarized. This mismatch results in a loss of signal strength between the mobile communication device and the base-station.
In order to overcome this problem, base-stations or the like can be configured to have horizontally polarized antennas in order to match the horizontally polarized antennas in the mobile communication devices. Such a solution is easiest to implement when designing a network infrastructure from scratch. However, if the mobile communication device is to be used in an existing infrastructure, it is a deterrent to suggest that the existing network infrastructure be overhauled in order to use the mobile communication device efficiently. Further, it is likely that the mobile communication device will be used along with a plurality of different devices, potentially having differently polarized antennas, exacerbating the problem. Yet further, as described above, it is more expensive to provide a base-station having an omni-directional antenna that is horizontally polarized.
Therefore it is an object of the present invention to obviate or mitigate at least one of the above mentioned disadvantages.
SUMMARY
In accordance with an aspect of the present invention there is provided a bracket assembly for attaching to a mobile computing device, the mobile computing device having a use range at which the mobile device is typically positioned when in use, the use range being between a low end angle and a high end angle, the mobile computing device comprising a housing having a reference plane, the bracket assembly configured to support a first antenna at a first angle and a second antenna at a second angle, each of the first angle and the second angle being measured with respect to the reference surface when the bracket assembly is attached to the mobile computing device, the first angle being selected so that the first antenna is in a vertical plane when the mobile computing device is positioned at the low end angle, the second angle being selected so that the second antenna is in a vertical plane when the mobile computing device is positioned at the high end angle.
In accordance with a further aspect of the present invention there is provided a mobile computing device having a use range at which the mobile device is typically positioned when in use, the use range being between a low end angle and a high end angle, the mobile computing device comprising: a housing having a reference plane; a computing assembly located within the housing; a radio transceiver configured to transfer data between the computing assembly and a remote transceiver; an antenna assembly operably connected to the radio transceiver to propagate signals from the radio transceiver to the remote transceiver and to apply signals received from the remote transceiver to the radio transceiver, the antenna assembly comprising: at least a first antenna and a second antenna; and a bracket assembly configured to support the first antenna at a first angle and the second antenna at a second angle, each of the first angle and the second angle being measured with respect to the display surface of the display screen, the first angle being selected so that the first antenna is in a vertical plane when the mobile computing device is positioned at the low end angle, the second angle, being selected so that the second antenna is in a vertical plane when the mobile computing device is positioned at the high end angle.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will now be described by way of example only with reference to the following drawings in which:
FIG. 1 is a perspective view of a mobile computing device with antennas configured in accordance with an embodiment;
FIG. 2 is a perspective view of the mobile computing device without an endcap, illustrating the antennas;
FIG. 3 a is a side view of the mobile computing device;
FIG. 3 b is a side view of the mobile computing device at a typical use angle;
FIG. 3 c is a front view of the mobile computing device; and
FIG. 4 is a side view of an alternate embodiment of the mobile computing device.
FIG. 5 is a side view of yet an alternate embodiment of the mobile computing device; and
FIG. 6 is a front view of yet an alternate embodiment of the mobile computing device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
For convenience, like numerals in the description refer to like structures in the drawings. Referring to FIG. 1 , a mobile computing device is illustrated generally by numeral 100 . Mobile computing device 100 comprises a main body 102 , a screen 104 , a keypad 106 and an endcap 108 . In the present embodiment, mobile computing device 100 is constructed to be modular and readily configurable to accommodate different modules. For example, an antenna, or antennas, can be placed beneath endcap 108 . This modularity allows antennas to be easily removed, added or replaced.
Referring to FIG. 2 , mobile computing device 100 without endcap 108 is illustrated. In the present embodiment, mobile computing device 100 further comprises a first antenna 202 , a second antenna 204 and a bracket assembly 206 . In the present embodiment, first antenna 202 and second antenna 204 comprise an antenna as described in U.S. Pat. No. 7,050,009, titled “Internal Antenna”, issued to Laurian P. Chirila. First antenna 202 and second antenna 204 are attached to main body 102 via bracket assembly 206 . First antenna 202 and second antenna 204 are electrically connected to a radio transceiver (not shown) for processing signals received or to be transmitted via first antenna 202 or second antenna 204 . In the present embodiment, the radio transceiver is configured to operate using antenna diversity to select one of first antenna 202 or second antenna 204 depending on a number of different factors, including signal strength. The design, selection and operation of such antenna diversity schemes will be readily apparent to those of skill in the art and will not be described further herein.
As illustrated in FIG. 2 , first antenna 202 and second antenna 204 are positioned at an angle to mobile computing device 100 and are not necessarily parallel to each other, as will be described in greater detail with reference to FIGS. 3 a , 3 b and 3 c.
Referring to FIG. 3 a , a side view of mobile computing device 100 without endcap 108 is illustrated. A first axis X 1 extends in a plane defined by screen 104 . In the present embodiment, both first antenna 202 and second antenna 204 are positioned at an inclination angle θ 1 to first axis X 1 . Further, in the present embodiment, screen 104 is substantially coplanar, or parallel, with an upper surface of main body 102 .
Referring to FIG. 3 b , a side view of mobile computing device 100 with endcap 108 is illustrated. As shown in FIG. 3 b , mobile computing device 100 is in a typical use position.
In order to match polarization of first antenna 202 and second antenna 204 as much as possible with vertically polarized base-station antennas, it is desirable that first antenna 202 and second antenna 204 be substantially vertical when mobile computing device 100 is in use. Thus, inclination angle θ 1 is selected so that when mobile computing device 100 is in a position in which it is anticipated to be used, referred to as the use position, first antenna 202 and second antenna 204 will be aligned in a vertical plane. The use position can be estimated through one or more of experimentation, field trials or ergonomic study.
Referring to FIG. 3 c , a front view of mobile computing device 100 without endcap 108 is illustrated. As illustrated, first antenna 202 and second antenna 204 are not positioned parallel to each other. Therefore, when the mobile compute device 100 is in the use position, first antenna 202 and second antenna 204 include both a vertically polarized component and a horizontally polarized component. Further, in the present embodiment, first antenna 202 and second antenna 204 are symmetric about symmetry axis X 2 .
As will be appreciated by a person of ordinary skill in the art, positioning first antenna 202 and second antenna 204 as described provides a number of advantages. For example, first antenna 202 and second antenna 204 will be positioned in a substantially vertical plane during use. Although it is difficult to predict an exact use position, positioning first antenna 202 and second antenna 204 based on the anticipated use position increases the likelihood of first antenna 202 and second antenna 204 being in a vertical plane, or substantially vertical plane, when mobile computing device 100 is in use.
As another example, often times mobile computing device 100 has space restrictions, especially at endcap 108 . Accordingly, positioning first antenna 202 and second antenna 204 so they are not parallel can help position them within endcap 108 by reducing the overall height required for the first antenna 202 and second antenna 204 .
As another example, although a majority of base-station antennas are configured for vertical polarization, some network infrastructures may include one or more base-station antennas configured for horizontal polarization. Accordingly, positioning first antenna 202 and second antenna 204 so they are not parallel provides some amount of horizontal polarization. Such horizontal polarization will likely improve the signal strength between mobile computing device 100 and base-stations having antennas that are horizontally polarized.
As another example, whenever an electromagnetic wave is reflected off a metallic surface, its polarization will shift. In an open environment, the polarization of the signal received at mobile computing device 100 will be similar to the polarization of the base-station antenna. However in a dense environment, such as a warehouse for example, multipath propagation of a signal transmitted from the base-station is present and the polarization of the signal received at mobile computing device 100 may include both vertically polarized and horizontally polarized vectors. Having first antenna 202 and second antenna 204 positioned inside the terminal to include some horizontal polarization allows mobile computing device 100 to work at a reasonable performance under these conditions.
In the embodiment described above, screen 104 is substantially coplanar with or parallel to main body 102 . Referring to FIG. 4 , an alternate embodiment of mobile computing device 100 is shown. In the present embodiment, screen 104 is configured at a screen angle θ S to main body 102 .
Similar to the previous embodiment, it is desirable that first antenna 202 and second antenna 204 are in a substantially vertical plane when mobile computing device 100 is in use. Thus, screen angle θ S may also need to be considered when determining inclination angle θ 1 .
Accordingly, when an operator uses mobile computing device 100 , first antenna 202 and second antenna 204 will be in a substantially vertical plane, thereby providing substantially vertical polarization.
As will be appreciated by a person of ordinary skill in the art, the proximity of first antenna 202 and second antenna 204 to the vertical plane largely depends on the precision of the estimation of the use position. However, even if the use position is not precisely estimated, the position of first antenna 202 and second antenna 204 is still improved when compared with the prior art, thereby improving the signal strength for communication with the base-stations.
Referring to FIG. 5 , an alternate embodiment of mobile computing device is illustrated. In this embodiment, first antenna 202 and second antenna 204 are configured at different angles to first axis X 1 . In the previous embodiments, both first antenna 202 and second antenna 204 are configured at inclination angle θ 1 . However in the present embodiment, first antenna 202 is configured at a first inclination angle θ 1A and second antenna 204 is configured at a second inclination angle θ 1B . It will be appreciated that where θ 1A =θ 1B , the antenna configuration is the same as the previously described embodiments. However, where θ 1A ≠θ 1B first antenna 202 and second antenna 204 can be configured to provide a use range of varying use positions for mobile computing device 100 . The use range spans from a predetermined low end angle to a predetermined high end angle. That is, for example, if it is determined that use position may range from a low end angle of 40° to high end use angle of 50°, first inclination angle θ 1A is selected to be 90°−40°=50° and second inclination angle θ 1B is selected to be 90°−50°=40°. Therefore, the potential variation in use position is accounted for by the variation in configuration between first antenna 202 and second antenna 204 . As mentioned above, depending upon the position of device 100 , one of first antenna 202 and second antenna 204 is selected for use by a suitable antenna diversity scheme, as is known in the art.
In the embodiments described above, first antenna 202 and second antenna 204 are connected to main body 102 via bracket assembly 206 . In an alternate embodiment, bracket assembly 206 is rotatably connected to main body 102 , thereby permitting in-field modification to the positioning of first antenna 202 and second antenna 204 within mobile computing device 100 . Once bracket assembly 206 is rotated into a desired position, it is fixed in that position using a set screw or other known mechanism.
In yet another alternate embodiment, first antenna 202 and second antenna 204 are attached to bracket assembly 206 via a flexible material, thereby permitting in-field modification to the configuration of first antenna 202 and second antenna 204 . The flexible material is sufficiently pliable to allow intentional modification of first inclination angle θ 1A and second inclination angle θ 1B , yet is also sufficiently resilient so as to resist accidental modification thereof. The flexible material may be a plastic or other material, but care must be taken not to inhibit the performance of either first antenna 202 or second antenna 204 .
Bracket assembly 106 described above may comprise a single bracket for both first antenna 202 and second antenna 204 or a separate bracket for each of first antenna 202 and second antenna 204 .
Further, although previous embodiments describe first antenna 202 and second antenna 204 as being symmetric about symmetry axis X 2 , this need not be true for all implementations.
Referring to FIG. 6 , in an alternate embodiment, first antenna 202 and second antenna 204 are positioned so that first antenna 202 and second antenna 204 are parallel and θ 1A =θ 1B . As will be appreciated, in the present embodiment there will likely be little to no horizontal polarization of first antenna 202 and second antenna 204 based on their positioning within mobile computing device 100 . However, both first antenna 202 and second antenna 204 will be substantially vertical during use of mobile computing device, thereby providing greater vertical polarization. Thus, for example, the present embodiment may be preferable in an open environment comprising a plurality of base-stations having vertically polarized antennas.
Yet further, although the previous embodiment have been described with θ 1 , θ 1A , and θ 1B all being taken with reference the plane of screen 104 , it will be appreciated that this plane is one merely of choice and another reference plane, such as a plane of keypad 106 , for example, could also be used
Yet further, although the term mobile computing device is used herein with regard to a particular embodiment, it will be appreciated by a person of ordinary skill in the art that the term mobile computing device includes other implementations such as handheld computers, smart phones, personal digital assistants and the like.
In summary, it will be appreciated that the present invention provides an antenna configuration that results in an improved vertical polarization of the antenna when mobile computing device 100 is in use.
Although preferred embodiments of the invention have been described herein, it will be understood by those skilled in the art that variations and combinations may be made thereto without departing from the scope of the appended claims. | A bracket assembly is provided for attaching to a mobile computing device. The mobile computing device has a use range at which the mobile device is typically positioned when in use. The use range varies between a low end angle and a high end angle. The mobile computing device also has a housing having a reference plane. The bracket assembly is configured to support a first antenna at a first angle and a second antenna at a second angle, each of the first angle and the second angle being measured with respect to the reference surface when the bracket assembly is attached to the mobile computing device. The first angle is selected so that the first antenna is in a vertical plane when the mobile computing device is positioned at the low end angle. The second angle is selected so that the second antenna is in a vertical plane when the mobile computing device is positioned at the high end angle. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to an apparatus for pneumatically feeding fiber material to a plurality of carding machines with the intermediary of separate reserve chutes connected to each carding machine upstream thereof as viewed in the direction of material advance. The reserve or upper chutes, in turn, are coupled to a common pneumatic conveyor conduit and advance the fiber material to downstream-connected feed chutes. The fiber transporting conveyor conduit is coupled with an upstream located fiber processing machine, such as a fine opener and contains a fiber-transporting fan.
In a dual-chute card supplying arrangement as disclosed, for example, in U.S. Pat. No. 4,219,289 (issued Aug. 26, 1980) the filling conditions in the upper chute (reserve chute) are not allowed to greatly deviate from the desired normal conditions if a satisfactory uniformity of the fiber lap, as concerns width and time are to be ensured. It is noted that by "filling conditions" there are meant the material quantities in the upper chute, the compression and distribution of the material as well as the shape and size of the material accumulation on the separating surface. The filling conditions in the upper chute depend, among others, from the tuft-air ratio, the tuft size, the air resistance of the separating surface, that is, the shape and size thereof, the transport speed of the fiber tufts, the rate of air discharge and the velocity of air exit at the separating surfaces. Some of these magnitudes depend from the static air pressure, the air quantities and the velocity in the conveyor ducts (transport conduits) leading to the feed chutes. These last-named parameters, in turn, are determined by the operating point of the upstream-connected fan and the filling conditions at the separating surfaces of all downstream-arranged upper feed chutes as well as the geometry of the transport conduits. If fluctuations are maintained within certain narrow limits, satisfactory results can be obtained. The magnitudes of fluctuation are determined by the number of momentarily operating (that is, fiber-consuming) carding machines, the momentary flow rate of material per location, the extent of fiber opening performed on the material supplied to each location as well as the gliding properties and the air resistance of the material. Upon output fluctuations at the individual carding machines, as well as by starting and stopping the carding machines and by density fluctuations in the fiber supply, determined by an upstream-connected cleaning line, the filling conditions often change beyond permissible limits. It is necessary to perform modifications at a number of locations in order to adapt the filling conditions to the changed conditions of the material and the number of the connected carding machines. This is effected in practice usually only during a new setting of the equipment and involves significant expense. Despite such measures there remain, even during a preselected and desired operational condition of a fiber processing system, fluctuations of the filling conditions which are caused by changes during operation. Thus, in the case of each individual carding machine the output speed may change, for example, during coiler can replacement, operational disturbances, verifications, and the like or in case strongly fluctuating material quantities are supplied by the feeding fan into the conveyor duct system which feeds the upper feed chutes (reserve chutes).
In a known apparatus the basic speed of the fiber transport fan is set upon the first production of a predetermined lot for a given number of cards. Upon change of the lot type or a change of the number of cards, for example, because of retooling, interruption in operation, start or stoppage or the like, belt pulleys have to be replaced in order to change the basic speed of the fan and thus the air quantities and/or air velocities in the transport duct and in the reserve chutes of the card feeders. Such an apparatus has therefore the disadvantage that upon change in the composition of a lot or the number of operating cards, the conditions of air flow in the conveying duct may be adjusted only with a significant input of labor which is very time-consuming and causes long down periods.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved apparatus of the above-outlined type from which the discussed disadvantages are eliminated, which permits a particularly simple and rapid adaptation of the air flow conditions in the conveyor duct and in the reserve chute to new conditions upon alteration of a fiber lot or the number of the operating associated carding machines.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the air quantities and/or the air velocity in the conveyor duct is set as a function of lot-specific data or as a function of the number of the associated, momentarily operating carding machines.
By virtue of the fact that the air quantities and/or the air velocity in the conveyor duct is set as a function of the lot-specific data or as a function of the number of the operating carding machines, a simple and rapid adaptation of the air flow conditions in the conveyor duct or in the reserve chute may be achieved in case of a change in the fiber lot or a change in the number of operating cards.
Expediently, the dominantly determinative magnitude, such as lot-specific data (type or fineness of material and the like) and the number of the operating carding machines are determined and/or measured and after an evaluation of these magnitudes, the operation of the supply fan (rpm, flow rate and pressure of air) and - alternatively or additively-the magnitude of the supply channel cross section and/or separating surfaces on the upper chutes of the card feeders are adjusted. These changes are performed automatically and in a preprogrammed manner during resetting of the system and also, during its operation to compensate for operational fluctuations.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1a is a diagrammatic top plan view of a preferred embodiment of the invention, including a plurality of carding machines, each shown in an operating condition.
FIG. 1b is a diagrammatic illustration, similar to FIG. 1a, wherein only some of the carding machines are in an operating state.
FIG. 2 is a diagrammatic elevational view of a fiber supplying system according to another preferred embodiment of the invention.
FIG. 3 is a diagrammatic elevational view of a fiber supplying system according to still another preferred embodiment of the invention.
FIG. 4 is a diagrammatic fragmentary elevational view of a fiber supplying system according to still another preferred embodiment of the invention.
FIG. 5 is a schematic elevational view of a further feature according to the invention.
FIG. 6 is a diagrammatic elevational view of a further embodiment of the invention, including a central computer.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning to FIGS. 1a and 1b, there is illustrated therein a fiber tuft blending installation which has a plurality of feeders 1 equipped with weighing scales and an adjoining tuft blender 2 from which the fiber material is conveyed through a duct 3 to a fine opening assembly 4 which is formed of a condenser, a supply chute, a fine opener and a transport fan 5. The latter pneumatically advances the opened fiber material through a transport duct 6 to the card feeders 7, each supplying a separate, associated carding machine 8. While in the illustration according to FIG. 1a, all twelve cards 8 are in the state of processing fiber material, in the illustration according to FIG. 1b, fiber material is supplied only to six cards 8 which process the fiber material while the other six cards 8 are at a standstill.
Reverting to FIG. 1a, the electric drives 8' of the cards 8 are connected to a control device 9. Electric magnitudes (measuring values) representing the rpm of one or several rolls of the cards 8 are applied to the control device 9. The electric magnitudes may be taken directly from the drives or from a tachometer connected therewith. The output of the control apparatus 9 is connected with the drive motor 10 of the fiber conveying fan 5. If, according to FIG. 1b, in which the control apparatus 9 is not shown, six cards 8 are at a standstill then, according to the rpm of six operating carding machines 8, the rpm of the drive motor 10 is reduced whereupon the fan 5 delivers a reduced air quantity. In this manner, the air quantity is preselected as a function of the number of operating cards 8 or is automatically set wherein in case of a larger number of cards a larger rate of air flow and in case of a lower number of operating cards a lower rate of air flow will be set.
Turning to FIG. 2, there is illustrated a card feeding installation, for example, a "FLEXAFEED" model manufactured by Trutzschler GmbH & Co. KG, Monchengladbach, Federal Republic of Germany, in which the conveying duct 6 is connected to two fiber transporting fans 5 and 5' associated with a separate opener and cleaner 4, 4' so that fiber material is introduced into the conveyor duct 6 from two opposite ends to the reserve chute 7' of each card feeder 7. From each reserve chute 7' material is advanced to an associated feed chute 7". The purpose of the installation is to introduce simultaneously different types of fiber material, for example, cotton and chemical fibers into the conveyor duct 6 for processing by the cards 8. At the head of each card feeder 7 or, stated differently, between each adjoining card feeder 7 there is provided a separate, pneumatically operated shutoff gate 11a-11d which is actuated, for example, by a power cylinder symbolically shown at 12 and which divides the conveyor duct 6 into two zones in which the two different fiber material types are introduced. Thus, in FIG. 2, the gate 11c is in a closed position, as a result of which the first three cards 8 (counted from the left) receive material from the cleaner 4 and the last two cards 8 receive material from the cleaner 4'. The power cylinders 12 are in each instance electrically connected by means of a transducer 13 with the control apparatus 9 whose outputs are connected with the drive motors 10 and 10' associated with the respective fans 5 and 5'. When the position of the shutoff gates 11a, 11b, 11c and 11d changes, the control apparatus 9 varies the rpm of the drive motors 10 and 10' so that, accordingly, the fans 5 and 5' deliver more or less air. In this manner, the air quantity and thus the basic fan rpm is automatically adjusted as a function of the position of the shutoff gates 11a-11d.
Turning now to FIG. 3, downstream of the conveyor fan 5 the conveyor duct 6 contains a flow rate measuring device 14 which is electrically connected with the control (and/or regulating) apparatus 9 by means of a transducer 15. The outputs of the control apparatus 9 are pneumatically connected with setting devices, for example, pressure cylinders 16 which operate devices for changing the cross-sectional passage area of the conveyor duct 6. For this purpose, the latter may have, for example, a plurality of wall elements 17a, 17b and 17c which may be shifted towards or away from the opppositely located wall portions, so that the cross section of the conveyor duct 6 may be reduced or enlarged. The wall elements 17a-17c may be made of an elastic material (for example, rubber or the like) to thus ensure an advantageous seal. According to the embodiment illustrated in FIG. 3, the cross-sectional area of the conveyor duct 6 is changed in such a manner as a function of the air quantities that the value of the desired flow speed is maintained.
Turning now to FIG. 4, the control apparatus 9 (as opposed to the showing in FIG. 3) is connected with the shutoff gates 11a-11c at the head of the reserve chutes 7'. In this manner, the cross-sectional area of the conveyor duct 6 is preselected as a function of the position of the shutoff gates.
According to FIG. 5, a lateral wall of the reserve chute 7' is provided with air outlet openings 7a which may be closed by a gate 20 rotatably supported at one end at the chute wall. The position of the gate 20 may be varied by a power cylinder 21 which is connected with the control apparatus 9 (not shown in FIG. 5).
Turning now to FIG. 6, to the conveyor duct 6 there are connected a pressure measuring device 18 and a flow rate measuring device 14. The pressure measuring device 18, the flow rate measuring device 14, the driving devices of the cards 8 and the power cylinders 12 for the shutoff gates 11 are electrically connected by means of transducers (not shown) to a central control apparatus 9 (for example, a regulator or computer system) which may be a microcomputer with a microprocessor for calculating cross-relationships between measuring and setting magnitudes. The microcomputer may be a TMS model, manufactured by Trutzschler GmbH & Co. KG, Monchengladbach, Federal Republic of Germany. The output of the control apparatus 9 is connected with the drive motor 10 for the fan 5 by means of a motor control 19. The values for the air pressure, the air quantities, the air speed and the number of the operating cards 8 are applied individually or together to the control apparatus (regulator or computing system) 9 which processes the data and affects the rpm of the supply fan 5 and/or the cross-sectional area of the conveyor duct 6. Expediently, the control apparatus 9 is associated with a non-illustrated data memory (automatic desired value setter). In the memory there are stored the required rpm's, for example, for the conveyor fan 5 for determined types of fiber material (lots) or for a desired number of operating cards 8. According to these parameters, the fan rpm may be automatically or manually set or adapted in case of changes.
Advantageously, first the basic settings for the fan 5 and/or the cross-sectional area of the conveyor duct 6 are computed and fed to the apparatus. On such a signal there is superposed an additional regulating or setting magnitude whose value is derived from the momentary deviations of actual values from the desired values for the air speed, and/or air quantities and/or air pressure. The regulating apparatus 9 cooperates with a regulating apparatus which regulates the quantity of the supplied fiber tufts. Also, the regulating apparatus 9 may cooperate with a regulating apparatus which calls and/or monitors and/or regulates the card output. Instead of a supply fan 5 it is feasible to regulate, in the same manner, the rpm of a suction fan forming part of a system which effects fiber tuft conveyance by air suction flows.
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims. | An installation for pneumatically supplying fiber material to a plurality of carding machines arranged for simultaneous operation includes a plurality of card feeders, each being operatively connected to a separate carding machine. Each card feeder has a feed chute delivering fiber material to the carding machine associated therewith and a reserve chute delivering fiber material to the feed chute associated therewith. The installation further has a common transport conduit connected to the reserve chute of each card feeder and a fan contained in the common transport conduit for advancing fiber material by an air stream to the card feeders and a control arrangement for varying the flow rate of the fiber material in the common transport conduit as a function of at least one operational parameter of the installation. | 3 |
BACKGROUND OF THE INVENTION
This present invention relates to the field of plastic bags including reclosable fastener strips with complementary male and female interlocking profiles.
The introduction of a plastic membrane film between the complementary profiles of a reclosable fastener strip to form a gasket and make the fastener strip watertight is already known.
For example, in DK 90 167, the closure strip is U-shaped in cross-section to the profiles in their longitudinal direction. There are two profiles. Each profile is located on one branch of the U. One of these branches is welded to one wall of a bag so that when the branches of the U are pressed against one another, the profiles close over both walls.
U.S. Pat. No. 3,164,186 describes a bag with a funnel that includes a reclosable fastener strip. A tubular film is welded to this strip so as to cover the inside wall of the part of the funnel that is attached to the strip. When the profiles are engaged, the film forms a watertight seal between the interlocking profiles.
U.S. Pat. No. Re 34,554 also describes reclosable fastener strips with one or two membranes. These membranes are welded to the strips or co-extruded with them, and form a watertight seal between the interlocking profiles when the latter are engaged.
These references thus disclose special reclosable fastener strips but do not disclose how to make watertight conventional reclosable fastener strips whose interlocking male and female profiles are already engaged.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a process and an apparatus to make watertight interlocking male or female profiles that are already engaged with one another.
More precisely, the invention discloses a process and an apparatus to form a closure with a gasket, including the following steps:
moving a reclosable fastener strip consisting of two closure strips with engaged interlocking profiles parallel to the longitudinal direction of the closure strips; and
conveying, independently of the closure strips, a membrane to a positioning means in the path of motion of the reclosable fastener strips;
disengaging the profiles from one another;
gradually spreading apart the two closure strips;
introducing and positioning the membrane between the closure strips by use of the positioning means so that its movement downstream of the positioning means is parallel to the movement of one of the closure strips; and
pressing the strips together until the profiles are re-engaged with one another with the membrane between them.
The invention also contemplates an apparatus for implementing this process. The apparatus includes:
a system for moving a reclosable fastener strip, with interlocking profiles engaged with one another, parallel to the longitudinal direction of the strip;
means for positioning a membrane between the closure strips;
mean for separating the profiles in order to disengage the profiles from each other;
guiding control means for gradually separating the closure strips from one another up to the positioning means; and
means for pressing the strips against one another until the profiles are re-engaged with the membrane between them.
Advantageously, the process and apparatus according to the invention also make it possible to seal one edge of the membrane to at least one of the closure strips after the film has been introduced between the profiles.
Advantageously, the process and apparatus according to the invention are also used to introduce a membrane between two closure strips each having attached to it or integrally formed with it a sheet capable of forming one bag wall.
The membrane can be introduced between the profiles of a double profile reclosable fastener strip.
In an advantageous variant, the process according to the invention is characterized by the fact that at least one closure strip is separated from the other closure strip so as to completely clear the space at right angles to the other closure strip or strips.
The apparatus for practicing this particular embodiment of the process also includes guiding means for separating the closure strips in order to completely clear the space at right angles to the other closure strip. The maximum angle between the closure strips when separated may then be approximately 90°.
In an advantageous variant, the invention covers a method and apparatus for introducing the membrane in the form of a single, unfolded tape between the profiles.
Under another variant, the invention covers a method and apparatus for introducing between the profiles a membrane whose lateral portions are folded lengthwise onto themselves to form a double tape.
The invention also covers a reclosable fastener strip with interlocking profiles or a bag including such a reclosable fastener strip characterized in that it also includes a membrane introduced between the profiles according to the process of the invention.
Other aspects, advantages and objectives of the invention will become clear from a reading of the detailed description below.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more fully understood with reference to drawings in which:
FIG. 1 is a fragmentary schematic cross-sectional perspective view of a tube consisting of a plastic film and having a reclosable fastener strip for use in making bags on the apparatus and using the process in accordance with the invention;
FIG. 2 is a schematic longitudinal cross-section showing an apparatus for forming bags and equipped with a unit for introducing a membrane between interlocking profiles in accordance with the present invention;
FIG. 3 is a more detailed schematic side view of the unit for inserting a membrane between interlocking profiles on the bag-making apparatus of FIG. 2 and on which FIG. 3a is a longitudinal view, lateral with respect to the movement of the profiles and FIGS. 3b, 3c, 3d, 3e, 3f, 3g and 3h are schematic sectional views taken off FIG. 3a of the means B through K for controlling the positioning of the profiles;
FIG. 4 is a schematic cross-sectional view of the profile guide means D and E;.
FIG. 5 is a schematic cross-sectional view of the profile guide means H and J, as well as membrane positioning means G;
FIG. 6 is a schematic cross-sectional view of guide means J and K;
FIGS. 7a and 7b are schematic cross-sectional views of sealing means L;
FIG. 8 is a schematic cross-sectional view of a variant of the guide and positioning means shown in FIG. 5;
FIG. 9 is schematic top view of positioning means G of a variant shown in FIG. 6;
FIG. 10 is a schematic representation of another variant of positioning means G; in which FIG. 10a is a top view and figure 10b is a side perspective view;
FIG. 11 is a schematic cross-sectional view with respect to the longitudinal dimension of a tube that includes a double closing device on which the process according to the invention can be implemented;
FIG. 12 is a schematic cross-sectional view of a double recloseable fastener on which the process according to the invention can be implemented;
FIG. 13 is a schematic cross-sectional view depicting the movement of the profiles and membranes and the means for sealing the membranes to the reclosable fastener strips in which FIG. 13a shows a single membrane; FIG. 13b shows the sealing of the single membrane shown in FIG. 13a; FIG. 13c shows a looped, double membrane; and FIG. 13d shows the sealing of the double membrane; and
FIG. 14 is a schematic cross-sectional view of a variant of welding means L.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
According to a preferred embodiment, the process according to the invention is used for forming bags 300 including a membrane 100 to form a gasket for the reclosable fastener strip of the bag. For that purpose, a tube 200, equipped with a single recloseable fastener 3, is fed through a bag forming machine 1 equipped with a gasket adding device in accordance with the present invention.
Details of the tube 200 are shown in FIG. 1. The tube includes a film folded back onto itself to form a lower sheet 204 and an upper sheet 206. Each of these sheets, 204 and 206, serves to form a wall of the final bag 300 formed on the machine and includes a lower 4 and upper 6 closure strip, respectively. Each closure strip 4, 6 is sealed or co-extruded on the free longitudinal edge of its respective sheet 204, 206. The lower strip 4 includes a female profile 7 in the form of a groove. The upper strip 6 includes a male profile 9 that can become interlocked with the female profile 7. Profiles 7 and 9 may be in any form known to those skilled in the field. There may also be a number of profiles 7, 9 on each closure strip 4, 6.
FIG. 2 shows a machine 1 for forming bags and includes a unit 10 for inserting a membrane 100 between profiles 7 and 9. The various means of forming bags and introducing the membrane 100 are designated by letters A through N along the length of the machine. Thus, tube 200 is unwound from a reel A. The unwound tube 200 is then conveyed toward the assembly 10 for inserting the membrane 100 between the profiles of the reclosable fastener strip on the tube. The unit 10 for inserting the membrane 100 includes guides B, C, D, E, H, I, J, K which guide the closure strips of the reclosable fastener strip, means for positioning the membrane G and sealing means L.
The membrane 100 is unwound from a reel 110 by appropriate unrolling means at F. Reference is now made to FIG. 3 which is a more detailed representation of the membrane insertion device 10. The device 10 consists of a number of grooved and aligned rollers 14, 16, 18. It also includes grooved rollers 20, 22, 24 to guide the upper closure strip 6 which includes the male profile 9, and designed to clear a space at right angles to strip 4 which includes the female profile 7. In order not to overload FIG. 3, the male 9 and female 7 profiles are not shown. Flat-surfaced rollers 11, 13, 15, 17, 19, 21, 23, 25, 27 keep the lower closure strip 4 and/or the upper closure strip 6 in position against the grooved rollers 12, 14, 16, 18, 20, 22, 24 (the flat-surfaced rollers 23 cannot be shown on this figure as it is behind grooved roller 22).
Tube 200 with closure strips 4 and 6 passes between the first guide means B (FIGS. 3a and 3b), then is conveyed toward means C for separating the profiles (FIGS. 3a and 3c). At the separation means C, closure strips 4 and 6 are separated by a separator device 29 and guided by flat-surfaced rollers 13 and 27. The separator device 29 includes two grooves. These grooves are radially opposed and the respective bottoms of the grooves converge toward one another in the direction opposite the direction of movement of profiles 7, 9. A female 7 or male 9 profile is positioned in each of the grooves.
While closure strip 4 and the lower sheet 204 are guided in a straight line by the guide means D, the closure strip 6 and the upper sheet 206 are conveyed to the third guide means E. The guide means D consist of a grooved roller 14 and a flat-surfaced roller 15, both of them similar to the grooved roller and flat-surfaced roller of the first guide means B. The third guide means E consist of a grooved roller 20 and a flat-surfaced roller 21. As shown in FIG. 3a, the combined rollers 20 and 21 are tilted both with respect to the longitudinal plane and with respect to the transversal plane of unit 10 (FIG. 3a, FIG. 3e and FIG. 4). The angle of inclination of these wheels with respect to each of these planes is, for example, 45°.
The membrane 100 arrives at the bag making machine vertically and crosswise with respect to the direction of unwinding of the tube 200. The membrane 100 is guided and positioned on the lower strip 4 by positioning means G. In this embodiment of the invention, the positioning means G consists of a positioning roller 30. Roller 30 is a rotating cylinder whose axis of rotation is parallel to the plane of the closure strip 4 and perpendicular to the movement of the lower closure strip 4. The surface that generates the external rotation of the cylinder brushes against profile 7 of strip 4. Positioning means G can also be provided by an inclined and/or curved blade presenting a convex surface in contact with the membrane 100. Other geometries can also be envisaged for positioning means G.
The membrane 100 and the lower closure strip 4 are conveyed toward the fourth guide means H. The fourth guide means H consist of a grooved roller 16 and a flat-surfaced roller 17 which are similar to the first guide means B and the second guide means D. As shown on FIG. 3f, guide means H make it possible to apply the membrane 100 onto the closure strip 4. At this point of forward movement of the tube 200, the upper closure strip 6 and the upper sheet 206 are kept at their free end in a vertical position and reach the level of the fifth guide means I (FIG. 3a, FIG. 5). The planes of lower 4 and upper 6 strips then form an angle α between them, which is equal to a maximum of approximately 90°. Thus, the upper closure strip 6 is separated from the lower closure strip so as to completely free up the necessary space for positioning the membrane 100 on the lower strip 4.
After the membrane 100 is positioned on the lower closure strip 4, the upper closure strip 6 and sheet 206 are gradually moved back into position on the lower strip 4 and the lower sheet 204. This is done with sixth guide means J, consisting of a grooved roller 24 and a flat-surfaced roller 25, which are similar to the third guide means E. The male profile 9 is then re-engaged in the female profile 7 at the location of the guide means K (FIG. 6: on this figure, guide means J are shown by dotted lines to indicate that they are not in the same plane as guide means K). The guide means K are made of a small grooved roller 18 and a small flat-surfaced roller 19, both similar to the rollers of the first, third and fourth guide means B, D, H already described. At guide means K the membrane 100 is inserted between the male 7 and female 9 profiles of the lower 4 and upper 6 closure strips.
The entire assembly of the lower closure strip 4, upper closure strip 6, the lower sheet 204 and upper sheet 206, which also rest on one another, is then conveyed toward sealing means L. Sealing means L consist, for example, of a pressure bar 40 and heating means 45, the pressure bar 40 applying the heating means 45 on to the membrane 100 to seal the membrane 100 to the lower closure strip 4 (FIG. 7a).
According to one variant, the membrane 100 is sealed to the upper closure strip 6, by the pressure bar 40, and heating means 45 that press and heat the membrane 100 and the upper closure strip 6 together (FIG. 7b). Other sealing means L will be described below.
The tube 200 are then be conveyed toward cutting means M to be transformed in a conventional manner into bags 300. The bags 300 are them stacked at a stacking station N.
Numerous variants of the process and of the apparatus described above, can be envisaged while continuing to be in accordance with the invention. Thus, positioning means G can consist of positioning rollers 32, 34, 36, 38 (FIGS. 8 and 9). These rollers 32, 34, 36, 38 are similar in form to that of rollers 30 already described. As shown on FIGS. 8 and 9, rollers 36, 38 are oriented with their axis of revolution parallel to the movement of the lower strip 4. A slight space is reserved between these rollers 36, 38 to guide the membrane 100 to arrive crosswise with respect to the movement of strip 4. Below rollers 36, 38, the membrane 100 is twisted 90° so as to extend over its entire width between rollers 32, 34. The axis of rollers 32, 34 is in a plane parallel to that of closure strip 4 and perpendicular to the direction of movement of closure strip 4. As illustrated in FIG. 8, according to this form of embodiment of the apparatus according to the invention, the space to be reserved at right angles to the closure strip 4 to bring the membrane 100 in contact with the closure strip, is smaller than the space shown in FIG. 5. Thus, guide means I can be inclined, for example, at a 45° angle above the lower closure strip 4. This makes it possible to reduce the torsion imposed on the upper closure strip 6, and to reduce the dimensions of the overall machine 10.
As shown on FIG. 10, in another variant of the apparatus 10 according to the invention, positioning means G include at least one roller 30. FIG. 10a shows a membrane 100 folded in a U shape around the roller 30. The planes of the portions of the membrane 100 before and after the roller 30 are parallel to the plane of the lower closure strip 4. The direction of arrival of the membrane 100 on roller 30 and the departing direction form an angle β which can be more or less open. This configuration can permit further reduction of the angle between lower 4 and upper 6 strips.
The form of embodiment of the process has been described above for the purpose of introducing a sealing membrane 100 between two closure strips 4, 6 of a single recloseable fastener 3 linked to sheets 204, 206 that are capable of forming the walls of a bag 300.
The process for forming a closure strip with a membrane described above can be used both for tubes 200 with single recloseable fastener 3 and for tubes 200 with double recloseable fasteners 5 as shown on FIG. 11. The reclosable fastener strip of FIG. 11 includes a lower closure strip 4, and two upper closure strips 6. The lower strip 4 has two female profiles 7. The two female profiles 7 are at spaced intervals from one another over the width of the closure strip 4. The upper strips 6 each have a male profile 9. The two upper strips 6 are separated from one another by a space 8 extending longitudinally with respect to the profiles 9. The lateral portions of the strips 4 and 6, located on the other side of the profiles with respect to the space 8, are linked respectively to lower and upper sheets 204 and 206 that are capable of forming the walls of a bag 300. This double recloseable fastener 5 is symmetrical with respect to the center of space 8. Sheets 204 and 206 can form either one sheet folded over onto itself, parallel to its longitudinal direction to form a U-shaped cross-section profile as indicated in FIG. 11, or, if separated they can be sealed to one another at their distal edges. In both instances, two symmetrical tubes are formed with respect to the space 8.
Alternatively, another process according to the invention also makes it possible to introduce a membrane 100 between two strips 4, 6 and to seal the membrane 100 to the closure strips, which will only be sealed later to a bag 300 or a sheet capable of forming such a bag 300.
FIG. 12 illustrates an example of strips 4, 6 that are not as yet attached to sheets 204, 206 capable of forming a bag 300. These strips 4, 6 constitute a double recloseable fastener 5 that differs from the one shown on FIG. 11 in that the lateral parts of the strips 4 and 6, located on either side of the profiles with respect to the space 8, rejoin to form a U-shaped profile in cross-section. Each of the two sets of strips 4, 6 located on either side of the space 8 can be welded at a later time to the walls of bags 300 in a manner familiar those skilled in the art.
FIG. 13 is a schematic illustration of how to seal either a single or double membrane 100 on to a double recloseable fastener. FIGS. 13b and 13d are cross sectional views at the level of sealing means L. Single and double membranes are shown in cross-section on FIGS. 13a and 13c, respectively. The double membrane 100 on FIG. 13c is formed by longitudinally folding over its lateral portions, while preserving a space between its free longitudinal edges of its median zone.
Once introduced between the profiles 7, 9 of strips 4, 6, the membrane 100 is sealed by its longitudinal median zone only to the lower strip 4. When the membrane is doubled over, the membrane 100 is sealed by its longitudinal median zone to the lower strip 4 and by its two folded lateral portions to the upper strip 6.
The sealing operation is performed by a sealing bar 42 which presses the membrane 100 at the location of space 8 to the upper face of the lower strip 4 against an anvil 44. The sealing bar 42 has a back and forth movement perpendicular to the plane of movement in which the lower strip 4 moves. The sealing bar 42 includes a flat sealing surface parallel to the plane of the lower strip 4. This flat surface is perpendicular to the direction of application of the pressure necessary for sealing and presses the membrane 100 and the lower strip 4 against the anvil 44.
In order to seal a doubled over membrane 100, the sealing bar 42 includes two shoulders 41, 43. The shoulders 41, 43 extend at right angles on either side of the end of sealing bar 42, and include the flat sealing surface parallel to the plane of the lower strip 4. These shoulders 41, 43 run along the entire length of the sealing bar 42 in a direction parallel to the movement of the lower strip 4. Other sealing bars 46 flank the bar 42. They have a flat sealing surface perpendicular to the direction of application of the sealing pressure through the bar 42. These other sealing bars 46 make it possible to seal the free longitudinal edges of the membrane 100 on to the lower face of the upper strip 6, pressing them together on the shoulders 41, 43.
A single membrane 100 presents the following advantages: it furnishes a sealing gasket over the entire length of the profiles 7, 9; if it is made of very meltable material (EVA, for example), it encapsulates the welded ends of the profiles 7, 9 and makes them also watertight.
A doubled over membrane 100 makes it possible to provide a tamper evident feature. Also, if it is long enough, when product contained in a bag 300 is poured out, it can be turned inside out to protect the profiles 7, 9 and possibly also to form a pouring spout or funnel.
Another way of providing a tamper evident feature is to seal each of the free longitudinal edges of a membrane 100 to different edges of strip 4, 6. FIG. 14 illustrates sealing means L compatible with this form of embodiment of the invention. The apparatus for forming watertight closures according to the invention can also include a pair of sealing means similar to those described above and illustrated in FIG. 7. Sealing bars 42 and 46 described above may advantageously be replaced by small sealing wheels when continuous sealing of the membrane 100 to a recloseable fastener 3, 5 is desired. | A continuous method of providing a gasket to a reclosable fastener strip having reclosable closure strips with interlocking profiles. The fastener strip is moved longitudinally, the profiles are disengaged and the closure strips are separated by approximately 90° from one another. A membrane is conveyed, independently of the fastener strip, along a path that brings it parallel to one of the closure strips. Thereafter, the separated closure strips are brought back together to sandwich the membrane between their respective profiles and the profiles are re-engaged. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a Divisional application of application Ser. No. 09/829,061 filed Apr. 9, 2001 (U.S. Pat No. 6,720,375).
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an adhesive composition and an adhesive optical component using the adhesive composition. More particularly, the present invention relates to an adhesive composition which, by application to easily hydrolyzable materials such as substrates and adherends, suppresses degradation of the materials by hydrolysis and improves durability of the materials; an adhesive composition which provides excellent stress relaxation without plasticizers, suppresses degradation of easily hydrolyzable materials such as substrates and adherents by hydrolysis by application to the material, suppresses degradation of the composition itself and gives adhesive optical components having excellent quality; and an adhesive optical component comprising the adhesive composition such as a polarizing plate and a plate for phase differentiation.
2. Description of Related Art
As the adhesive, acrylic adhesives, polyurethane adhesives, polyester adhesives, rubber adhesives and silicone adhesives have heretofore been used. Among these adhesives, acrylic adhesives are widely used. An acrylic adhesive contains, in general, a copolymer of (meth)acrylic esters and a crosslinking agent. As the copolymer of (meth)acrylic esters, for example, a copolymer of a (meth)acrylic ester such as butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate and decyl (meth)acrylate with a functional monomer for forming crosslinking points is used. The functional monomer is, specifically, a functional monomer having hydroxyl group such as hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate or a functional monomer having carboxyl group such as (meth)acrylic acid, maleic acid, crotonic and itaconic acid.
However, when the acrylic adhesive is applied to a material which is easily hydrolyzed such as films of cellulose acetate, a problem arises in that the material tends to be hydrolyzed due to the effect of carboxyl group in the copolymer of (meth)acrylic esters contained in the acrylic adhesive. The degradation of the material by hydrolysis takes place markedly, in particular, under an environment of a high temperature and high humidity.
Some optical components are used after a polarizing plate is attached to the surface. Typical examples of such optical components include liquid crystal cells in liquid crystal displays (LCD). In general, a liquid crystal cell has a structure in which two transparent electrode substrates having an oriented layer are placed in a manner such that a specific gap is formed between them with a spacer and the oriented layers face to each other at the inside, peripheral portions of the transparent electrode substrates are sealed, a liquid crystalline material is placed and held inside the gap between the transparent electrode substrates and a polarizing plate is disposed on each outer surface of the two transparent electrode substrates via an adhesive layer.
FIG. 1 shows a perspective view exhibiting the structure of an example of the polarizing plate described above. As shown in FIG. 1 , the polarizing plate 10 has a substrate having a three-layer structure in which triacetylcellulose (TAC) film I 2 and TAC film II 2′ are laminated on the faces of a polarizing plate 1 made of polyvinyl alcohol. On one face of the substrate, an adhesive layer 3 for sticking the substrate to an optical component such as a liquid crystal cell is formed. A release sheet 4 is attached to the adhesive layer 3 . In general, a film for protecting the surface 5 is disposed on the face of the polarizing plate opposite to the face having the adhesive layer 3 .
When the above polarizing plate is attached to the above liquid crystal cell, the release sheet 4 is removed first, then the polarizing plate is stuck to the liquid crystal cell via the exposed adhesive layer and the film for protecting the surface 5 is removed.
For the adhesive layer disposed on the polarizing plate, acrylic adhesives are widely used. However, as described above, the acrylic adhesive promotes hydrolysis of the TAC film of the polarizing plate due to the effect of carboxyl group in the copolymer of (meth)acrylic esters and the polarizing plate is degraded. The degradation of the polarizing plate takes place markedly, in particular, under an environment of a high temperature and a high humidity.
In liquid crystal display apparatuses of the STN type, it is widely conducted that a plate for phase differentiation is disposed between a liquid crystal cell and a polarizing plate. As the plate for phase differentiation, in general, a laminate having a TAC film on one or both faces of a stretched film of polyvinyl alcohol and a layer of an acrylic adhesive on the face of the TAC film, is used. An liquid crystal cell is formed by laminating one or a plurality of plates for phase differentiation to an STN cell via the above adhesive layer and then laminating a polarizing plate on the outermost layers. The thus prepared liquid crystal cell also has a problem in that degradation of the TAC film by hydrolysis takes place in the plate for phase differentiation similarly to the degradation of the TAC film in the polarizing plate.
To overcome the above problems, for example, a method in which the amount of carboxyl group contained in the adhesive is decreased (Japanese Patent Application Laid-Open No. Showa 59(1984)-111114) and a method in which a tertiary amine is added (Japanese Patent Application Laid-Open No. Heisei 4(1992)-254803) have been proposed. However, the method in which the amount of carboxyl group is decreased has a drawback in that the excellent balance between the physical properties of the adhesive is inevitably lost and the method in which a tertiary amine is added has a drawback in that the pot life of the adhesive decreases since control of the reactions between a crosslinking agent and various functional groups in the adhesive becomes difficult and workability in various steps deteriorates.
The polarizing plate which is attached to the liquid crystal cell via the adhesive layer has the three-layer structure described above. Due to the properties of the materials, the polarizing plate has poor dimensional stability and, in particular, change in the dimension by contraction or expansion is great in the environment of a high temperature or a high temperature and a high humidity.
However, since, in general, an adhesive having a great adhesive ability is used in the above polarizing plate, stress caused by the change in the dimension of the polarizing plate cannot be absorbed and relaxed by the adhesive layer although lifting and peeling caused by the change in the dimension of the polarizing plate can be suppressed. More specifically, in FIG. 1 , TAC film II 2′ at the front face tends to contract or expand due to change in the humidity and the temperature. On the other hand, TAC film I 2 cannot not contract or expand easily since TAC film I is firmly adhered to the liquid crystal cell via the adhesive layer 3 and the adhesive layer cannot flexibly follow the change in the dimension. As the result, ray passing through TAC film I toward TAC film II cannot proceed straight. This causes undesirable phenomena such as leak of light.
To overcome the above problems, heretofore, a plasticizer is added to the adhesive so that the adhesive is flexible to a suitable degree and stress relaxation takes place. However, the adhesive containing a plasticizer has drawbacks in that the plasticizer bleeds out and that the adherend is stained with the plasticizer when the polarizing plate is peeled by the bleeding out. When a polyfunctional crosslinking agent having a functionality of three or greater is used in an adhesive, the number of crosslinks in the adhesive is decreased. However, the holding ability, i.e., the adhesion with the adherend, inevitably decreases in this case and problems such as lifting and peeling of the polarizing plate tend to arise with passage of the time.
Intensive studies on adhesive compositions exhibiting excellent stress relaxation without adding plasticizers have been made by the present inventors to overcome the above problems and it was found that excellent stress relaxation can be exhibited by using a copolymer of (meth)acrylic esters having a great molecular weight and an oligomer of (meth)acrylic esters having a small molecular weight in combination. However, when this adhesive composition is applied to a polarizing plate and the like, it was found that an undesirable phenomenon occasionally took place in that brightness was different at portions around the edges and at other portions of the polarizing plate.
Moreover, a problem takes place in the acrylic adhesive in that the molecular weight of the copolymer of (meth)acrylic esters decrease since degradation takes place under a condition of a high temperature and a high humidity although the degradation proceeds slowly. As the result, cohesive force in the adhesive becomes insufficient and lifting and peeling take place between a substrate such as a polarizing plate and a plate for phase differentiation and an adherend such as a plate of glass or polycarbonate.
SUMMARY OF THE INVENTION
Under the above circumstances, the present invention has a first object of providing an adhesive composition which suppresses degradation of easily hydrolyzable materials by hydrolysis and improves durability of the materials when the adhesive composition is applied to the materials; a second object of providing an adhesive composition which provides excellent stress relaxation without plasticizers, suppresses degradation of easily hydrolyzable materials by hydrolysis when the adhesive composition is applied to the materials, suppresses degradation of the composition itself and gives adhesive optical components having excellent quality; and a third object of providing an adhesive optical components such as a polarizing plate and a plate for phase differentiation which comprise a layer of the above adhesive composition.
As the result of intensive studies by the present inventors to achieve the above objects, it was found that the first object can be achieved with an adhesive composition comprising a copolymer of (meth)acrylic esters, a crosslinking agents and a phenol derivative, that the second object can be achieved with an adhesive composition comprising a copolymer of (meth)acrylic esters or, preferably, a mixture of a copolymer of (meth)acrylic esters and an oligomer of (meth)acrylic esters, a crosslinking agent, a radical scavenger and, optionally, a secondary antioxidant and that the third object can be achieved by disposing a layer comprising the adhesive composition obtained as described above at least on one face of an optical component.
The present invention has been completed based on the above knowledge.
The present invention provides:
(1) An adhesive composition which comprises (A) a copolymer of (meth)acrylic esters, (B) a crosslinking agent and (C) a phenol derivative (referred to as adhesive composition I, hereinafter); (2) An adhesive optical-component comprising an optical component and a layer which comprises adhesive composition I and is disposed at least on one face of the optical component (referred to as Adhesive optical component I, hereinafter); (3) An adhesive composition which comprises (D) a copolymer of (meth)acrylic esters having a weight-average molecular weight of 500,000 to 2,500,000, (E) a crosslinking agent and (F) a radical scavenger (referred to as adhesive composition II, hereinafter); (4) An adhesive composition which comprises (D′) a mixture of a copolymer of (meth)acrylic esters having a weight-average molecular weight of 500,000 to 2,500,000 and an oligomer of (meth)acrylic esters having a weight-average molecular weight of 1,000 to 10,000 in amounts such that a ratio of the amounts by weight of the copolymer to the oligomer is in a range of 100:5 to 100:100, (E) a crosslinking agent and (F) a radical scavenger (referred to as adhesive composition II′, hereinafter); and (5) An adhesive optical component comprising an optical component and a layer which comprises any of adhesive compositions II and II′ and is disposed at least on one face of the optical component (referred to as Adhesive optical component II, hereinafter)
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a perspective view exhibiting the structure of an example of a polarizing plate.
In the figure, 1 means a polarizing plate made of polyvinyl alcohol, 2 means TAC film I, 2′ means TAC film II, 3 means an adhesive layer, 4 means a release sheet, 5 means a film for protecting the surface and 10 means a polarizing plate.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Adhesive composition I of the present invention will be described in the following.
Adhesive composition I of the present invention comprises a copolymer of (meth)acrylic esters as component (A), a crosslinking agent as component (B) and a phenol derivative as component (C).
As the copolymer of (meth)acrylic esters of component (A), copolymers having portions for crosslinking which can be crosslinked with the crosslinking agent of component (B) are used. The copolymer of (meth)acrylic ester having such portions for crosslinking is not particularly limited. A copolymer can be suitably selected from copolymers of (meth)acrylic esters which are conventionally used as the resin component of adhesives.
Preferable examples of the copolymer of (meth)acrylic ester having such portions for crosslinking include copolymers of a (meth)acrylic ester in which the alkyl group in the ester portion has 1 to 20 carbon atoms, a monomer having a functional group having an active hydrogen and other monomers which are used where desired.
Examples of the copolymer of a (meth)acrylic ester in which the alkyl group in the ester portion has 1 to 20 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, myristyl (meth)acrylate, palmityl (meth)acrylate and stearyl (meth)acrylate. The copolymers of a (meth)acrylic ester may be used singly or in combination of two or more.
Examples of the monomer having a functional group having an active hydrogen include hydroxyalkyl esters of (meth)acrylic acid such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate; acrylamides such as acrylamide, methacrylamide, N-methylacrylamide, N-methylmethacrylamide, N-methylolacrylamide and N-methylol-methacrylamide; monoalkylaminoalkyl (meth)acrylates such as monomethylaminoethyl (meth)acrylate, monoethylaminoethyl (meth)acrylate, monomethylaminopropyl (meth)acrylate and monoethylaminopropyl (meth)acrylate; and ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid and citraconic acid. The above monomers may be used singly or in combination of two or more.
Examples of the other monomers which are used where desired include vinyl esters such as vinyl acetate and vinyl propionate; olefins such as ethylene, propylene and isobutylene; halogenated olefins such as vinyl chloride and vinylidene chloride; styrenic monomers such as styrene and α-methylstyrene; diene monomers such as butadiene, isoprene and chloroprene; nitrile monomers such as acrylonitrile and methacrylonitrile; and N,N-dialkylsubstituted acrylamides such as N,N-dimethylacrylamide and N,N-dimethylmethacrylamide. The above monomers may be used singly or in combination of two or more.
In adhesive composition I of the present invention, the structure of the copolymer of (meth)acrylic esters used as component (A) is not particularly limited and any of random copolymers, block copolymers and graft copolymers can be used. As for the molecular weight, it is preferable that the weight-average molecular weight is in the range of 500,000 to 2,500,000. When the weight-average molecular weight is smaller than 500,000, there is the possibility that adhesion and durability of adhesion with the adherend are insufficient. When the weight-average molecular weight exceeds 2,500,000, the property of following change in the dimension of the substrate may deteriorate. From the standpoint of adhesion, durability of adhesion and the property of following change in the dimension of the substrate, it is preferable that the weight-average molecular weight is 800,000 to 1,800,000 and more preferably 1,200,000 to 1,600,000.
The weight-average molecular weight described above is the weight-average molecular weight of the corresponding polystyrene obtained in accordance with the gel permeation chromatography (GPC).
In the present invention, the copolymer of (meth)acrylic esters of component (A) may be used singly or in combination of two or more. Where desired, homopolymers and copolymers of (meth)acrylic esters having a small molecular weight such as a weight-average molecular weight of 100,000 or smaller can be used in combination with the above copolymer of (meth)acrylic esters having a great molecular weight.
The crosslinking agent of component (B) in adhesive composition I of the present invention is not particularly limited. A compound can be suitably selected from crosslinking agents which are conventionally used in acrylic adhesives. Examples of the crosslinking agent include polyisocyanate compounds, epoxy resins, melamine resins, urea resins, dialdehydes and methylol polymers. In the present invention, polyisocyanate compounds are preferably used.
Examples of the polyisocyanate compound include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate and xylylene diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate; alicyclic polyisocyanates such as isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate; biuret compounds and isocyanurate compounds derived from the above polyisocyanates; and adduct compounds which are reaction products of the above polyisocyanates with low molecular weight compounds having an active hydrogen such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane and castor oil.
In the present invention, the crosslinking agent of component (B) may be used singly or in combination of two or more. The amount is selected, in general, in the range of 0.001 to 50 parts by weight and preferably in the range of 0.01 to 10 parts by weight per 100 parts by weight of the copolymer of acrylic esters of component (A) although the amount may be different depending on the type of the crosslinking agent.
In adhesive composition I of the present invention, a phenol derivative is used as component (C). The phenol derivative is used for suppressing hydrolysis of the easily hydrolyzable material such as a film of acetylcellulose to which the adhesive composition of the present invention is applied.
As the phenol derivative, it is preferable that at least one compound is suitably selected, for example, from single ring phenol compounds, two-ring phenol compounds, three-ring phenol compounds and four-ring phenol compounds.
Examples of the phenol derivative include single ring phenol compounds such as 2,6-di-tert-butyl-p-cresol, butylhydroxyanisole and stearyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate; two-ring phenol compounds such as 4,4′-butylidenebis(3-methyl-6-tert-butylphenol) and 3,6-dioxaoctamethylenebis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate]; three-ring phenol compounds such as 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane; and four-ring phenol compounds such as tetrakis[methylene-3-(3′,5′-di-tert-butyl-4′-hydroxyphenyl) propionate]-methane.
In the present invention, the amount of the phenol derivative of component (C) is selected, in general, in the range of 0.01 to 10 parts by weight per 100 parts by weight of the copolymer of (meth)acrylic esters of component (A). When the amount is less than 0.01 part by weight, there is the possibility that the effect of suppressing hydrolysis is not sufficiently exhibited and the object of the present invention is not achieved. When the amount exceeds 10 parts by weight, the effect of suppressing hydrolysis is not exhibited to the degree expected from the used amount. Moreover, economic disadvantage arises and physical properties of adhesion may be adversely affected. From the standpoint of the effect of suppressing hydrolysis, the physical properties of adhesion and the economy, it is preferable that the amount of the phenol derivative is in the range of 0.05 to 5 parts by weight and more preferably in the range of 0.1 to 2 parts by weight.
Adhesive composition I of the present invention may further comprise various additives conventionally used for adhesive compositions such as plasticizers, silane coupling agents and ultraviolet absorbents as long as the additives do not adversely affect the objects of the present invention, where desired.
When a silane coupling agent, among the above additives, is added to the adhesive composition, adhesion to a liquid crystal cell (glass) under a hot and humid condition is improved and lifting and peeling of the polarizing plate and the plate for phase differentiation are suppressed. As the silane coupling agent, organic silicon compounds which have at least one alkoxysilyl group in the molecule, are compatible with the components of the adhesive composition and transmit light are preferably used. For example, substantially transparent organic silicon compounds having these properties are used. Examples of the silane coupling agent include vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, 3-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, 2-(3,4epoxycyclohexyl)ethyltrimethoxysilane, 3-aminopropyltriethoxysilane and N-phenyl-3-aminopropyltrimethoxysilane. It is preferable that the amount of the silane coupling agent is in the range of 0.001 to 10 parts by weight and more preferably in the range of 0.005 to 5 parts by weight per 100 parts by weight of the adhesive composition.
When adhesive composition I of the present invention having the above composition is applied to easily hydrolyzable materials, degradation of the materials by hydrolysis is suppressed and, in particular, durability under a high temperature and a high humidity can be improved. Therefore, adhesive composition I is advantageously applied to films of acetylcellulose which are easily hydrolyzed.
Adhesive compositions II and II′ of the present invention will be described in the following.
In adhesive composition II, a copolymer of (meth)acrylic esters alone is used as component (D) and, in adhesive composition II′, a mixture of a copolymer of (meth)acrylic esters and an oligomer of (meth)acrylic esters is used as component (D′).
As the copolymer of (meth)acrylic esters of component (D), a copolymer of (meth)acrylic esters having portions for crosslinking which can be crosslinked with the crosslinking agent of component (E) is used. The copolymer of (meth)acrylic esters having portions for crosslinking is not particularly limited. A copolymer can be suitably selected from copolymers of (meth)acrylic esters which are conventionally used as the resin component of adhesive compositions.
Preferable examples of the copolymer of (meth)acrylic esters having portions for crosslinking include copolymers of a (meth)acrylic ester in which the alkyl group in the ester portion has 1 to 20 carbon atoms, a monomer having a functional group having an active hydrogen and other monomers which are used where desired.
Examples of the (meth)acrylic ester in which the alkyl group in the ester portion has 1 to 20 carbon atoms, the monomer having a functional group having an active hydrogen and the other monomers which are used where desired include the (meth)acrylic ester in which the alkyl group in the ester portion has 1 to 20 carbon atoms, the monomer having a functional group having an active hydrogen and the other monomers which are used where desired, respectively, which are described as the examples of the components for the copolymer of (meth)acrylic esters of component (A) used in adhesive composition I.
In adhesive composition II of the present invention, the structure of the copolymer of (meth)acrylic esters used as component (D) is not particularly limited and any of random copolymers, block copolymers and graft copolymers can be used. The weight-average molecular weight of the copolymer is selected in the range of 500,000 to 2,500,000. When the weight-average molecular weight is smaller than 500,000, there is the possibility that adhesion and durability of adhesion with the adherend are insufficient. When the weight-average molecular weight exceeds 2,500,000, the property of following change in the dimension of the substrate may deteriorate. From the standpoint of adhesion, durability of adhesion and the property of following change in the dimension of the substrate, it is preferable that the weight-average molecular weight is 800,000 to 1,800,000 and more preferably 1,200,000 to 1,600,000.
The weight-average molecular weight described above is the weight-average molecular weight of the corresponding polystyrene obtained in accordance with the gel permeation chromatography (GPC).
In the present invention, the copolymer of (meth)acrylic esters of component (D) may be used singly or in combination of two or more.
In adhesive composition II′ of the present invention, a mixture of the copolymer of (meth)acrylic esters described above and an oligomer of (meth)acrylic esters can be used as component (D′) so that stress relaxation is provided.
The oligomer of (meth)acrylic ester may be any oligomer selected from oligomers obtained by homopolymerizing one compound selected from (meth)acrylic esters in which the alkyl group in the ester portion has 1 to 20 carbon atoms, oligomers obtained by copolymerizing at least two compounds selected from the above (meth)acrylic esters and oligomers obtained by copolymerizing at least one compound selected from the above (meth)acrylic esters with other monomers.
Examples of the (meth)acrylic ester in which the alkyl group in the ester portion has 1 to 20 carbon atoms and the other monomers include the (meth)acrylic esters in which the alkyl group in the ester portion has 1 to 20 carbon atoms and the other monomers, respectively, which are described as the examples of the components for the copolymer of (meth)acrylic esters of component (A) used in adhesive composition I.
The weight-average molecular weight of the oligomer of (meth)acrylic esters is selected in the range of 1,000 to 10,000. When the molecular weight is smaller than 1,000, the oligomer bleeds out and there is the possibility that an adherend is stained when a substrate adhered to the adherend via the adhesive composition is removed. When the molecular weight exceeds 10,000, there is the possibility that the property of following change in the dimension of the substrate (stress relaxation) of the adhesive composition deteriorates. From the standpoint of preventing staining of the adherend and the property of following change in the dimension of the substrate, it is preferable that the weight-average molecular weight of the oligomer of (meth)acrylic esters is in the range of 3,000 to 10,000.
It is preferable that the oligomer of (meth)acrylic esters has a ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) representing the molecular weight distribution of 2.0 or smaller. When the ratio Mw/Mn exceeds 2.0, there is the possibility that the oligomer contains components having excessively small molecular weights. Such components may cause bleeding out of the oligomer and staining of an adherend when a substrate adhered to the adherend via the adhesive composition is removed. It is more preferable that the ratio Mw/Mn is 1.7 or smaller.
The weight-average molecular weight and the number-average molecular weight described above are the weight-average molecular weight and the number-average molecular weight, respectively, of the corresponding polystyrene obtained in accordance with GPC.
In the present invention, the oligomer of (meth)acrylic esters may be used singly or in combination of two or more.
In adhesive composition II′ of the present invention, the oligomer of (meth)acrylic esters is used in an amount of 5 to 100 parts by weight per 100 parts by weight of the above copolymer of (meth)acrylic esters. When the amount of the oligomer is less than 5 parts by weight, the property of following change in the dimension of the substrate (stress relaxation) becomes insufficient. When the amount of the oligomer exceeds 100 parts by weight, adhesion with the adherend becomes poor. From the standpoint of the property of following change in the dimension of the substrate and adhesion with the adherend, it is preferable that the amount of the oligomer is in the range of 10 to 70 parts by weight and more preferably in the range of 15 to 50 parts by weight.
In adhesive compositions II and II′, the crosslinking agent of component (E) is not particularly limited. A crosslinking agent can be suitably selected from conventional crosslinking agents used for acrylic adhesives. Examples of the crosslinking agent include the compounds described as the examples of the crosslinking agent of component (B) in adhesive composition I.
In the present invention, the crosslinking agent of component (E) may be used singly or in combination of two or more. The amount of the crosslinking agent is selected, in general, in the range of 0.001 to 50 parts by weight and preferably in the range of 0.01 to 10 parts by weight per 100 parts by weight of the copolymer of (meth)acrylic esters of component (D) or the copolymer of (meth)acrylic esters in component (D′) although the amount may be varied depending on the type of the crosslinking agent.
Adhesive compositions II and II′ comprises a radical scavenger as component (F).
The radical scavenger is a compound which scavenges radicals generated by heat or light or with a heavy metal, suppresses initiation of chain reactions and inhibits chain reactions of the radicals. Since adhesive compositions II and II′ of the present invention comprise the radical scavenger, the following effects are exhibited:
(1) When adhesive compositions II and II′ are applied to an easily hydrolyzable material such as a film of acetyl cellulose, hydrolysis of the material is suppressed. (2) Degradation of the adhesive itself is suppressed and, even when an optical component in which the adhesive composition of the present invention is used is left standing under a condition of a high temperature and a high humidity, lifting and peeling are not easily formed. (3) When a copolymer of (meth)acrylic esters having a great molecular weight and an oligomer of (meth)acrylic esters having a small molecular weight are used in combination so that stress relaxation is exhibited, formation of uneven brightness can be suppressed in a polarizing plate to which the adhesive composition of the present invention is applied.
In the present invention, antioxidants, amine photostabilizers and polymerization inhibitors are preferably used as the radical scavenger.
As the antioxidant, phenolic antioxidants are preferable. Examples of the phenolic antioxidant include single ring phenol compounds such as 2,6-di-t-butyl-p-cresol, 2,6-di-t-butyl-4-ethylphenol, 2,6-dicyclohexyl-4-methylphenol, 2,6-diisopropyl-4-ethylphenol, 2,6-di-t-amyl-4-methylphenol, 2,6-di-t-octyl-4-n-propylphenol, 2,6-dicyclohexyl-4-n-octylphenol, 2-isopropyl-4-methyl-6-t-butylphenol, 2-t-butyl-4-ethyl-6-t-octylphenol, 2-isobutyl-4-ethyl-6-t-hexylphenol, 2-cyclohexyl-4-n-butyl-6-isopropylphenol, mixed cresol modified with styrene, DL-α-tocopherol and stearyl β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate; two-ring phenol compounds such as 2,2′-methylenebis(4-methyl-6-t-butylphenol), 4,4′-butylidenebis(3-methyl-6-t-butylphenol), 4,4′-thiobis(3-methyl-6-t-butyl-phenol), 2,2′-thiobis(4-methyl-6-t-butylphenol), 4,4′-methylenebis(2,6-di-t-butylphenol), 2,2′-methylenebis[6-(1-methylcyclohexyl)-p-cresol], 2,2′-ethylidenebis (4,6-di-t-butylphenol), 2,2′-butylidenebis(2-t-butyl-4-methylphenol), 3,6-dioxaoctamethylenebis[3-(3-t-butyl-4-hydroxy-5-methylphenyl) propionate], triethyleneglycol bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol bis[3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate] and 2,2′-thiodiethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate]; three ring phenol compounds such as 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-tris(2,6-dimethyl-3-hydroxy-4-t-butylbenzyl) isocyanurate, 1,3,5-tris[(3,5-di-t-butyl-4-hydroxy-phenyl)propionyloxyethyl] isocyanurate, tris(4-t-butyl-2,6-dimethyl-3-hydroxybenzyl) isocyanurate and 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene; four-ring phenol compounds such as tetrakis-[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate]methane; and phenol compounds containing phosphorus such as bis(ethyl 3,5-di-t-butyl-4-hydroxybenzylphosphonate) potassium and bis(ethyl 3,5-di-t-butyl-4-hydroxybenzylphosphonate) nickel.
Examples of the amine photostabilizer include bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, polycondensates of dimethyl succinate and 1 -(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine, tetrakis-(2,2,6,6-tetramethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, 2,2,6,6-tetramethyl-4-piperidyl benzoate, bis(1,2,6,6-pentamethyl-4-piperidyl) 2-(3,5-di-t-butyl-4-hydroxybenzyl)-2-n-butyl malonate, bis(N-methyl-2,2,6,6-tetramethyl-4-piperidyl) sebacate, 1,1′-(1,2-ethandiyl)-bis(3,3,5,5-tetramethylpiperadinone), (mixed 2,2,6,6-tetramethyl-4-piperidyl/tridecyl) 1,2,3,4-butanetetracarboxylate, (mixed 1,2,2,6,6-pentamethyl-4-piperidyl/-tridecyl) 1,2,3,4-butanetetracarboxylate, mixed [2,2,6,6-tetramethyl-4-piperidyl/β,β,β′,β′-tetramethyl-3,9-[2,4,8,10-tetraoxaspiro-(5,5)undecane]-diethyl] 1,2,3,4-butanetetracarboxylate, mixed [1,2,2,6,6-pentamethyl-4-piperidyl/β,β,β′,β′-tetramethyl-3,9-[2,4,8,10-tetraoxaspiro-(5, 5)undecane]-diethyl 1,2,3,4-butanetetracarboxylate, condensates of N,N′-bis(3-aminopropyl)ethylenediamine and 2,4-bis[N-butyl-N-(1,2,2,6,6-penta-methyl-4-piperidyl)amino]-6-chloro-1,3,5-triazine, poly[6-N-morpholyl-1,3,5-triazin-2,4-yl][(2,2,6,6-tetramethyl-4-piperidyl)imino]hexamethylene[(2,2,6,6-tetramethyl-4-piperidyl)imide], condensates of N, N′-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and 1,2-dibromoethane and [N-(2,2,6,6-tetramethyl-4-piperidyl)-2-methyl-2-(2,2,6,6-tetramethyl-4-piperidyl)imino]propionamide.
The polymerization inhibitor is an agent conventionally used as the polymerization inhibitor in radical polymerization. Examples of the polymerization inhibitor include divalent phenolic polymerization inhibitors such as hydroquinone, p-methoquinone, t-butylhydroquinone and t-butylcatechol; and phenothiazine.
In the present invention, the radical scavenger of component (F) may be used singly or in combination of two or more. The amount of the radical scavenger is selected, in general, in the range of 0.01 to 10 parts by weight per 100 parts by weight of component (D) or component (D′). When the amount is less than 0.01 part by weight, there is the possibility that the effect of the radical scavenger is not sufficiently exhibited and the object of the present invention is not achieved. When the amount exceeds 10 parts by weight, the effect of the radical scavenger is not exhibited to the degree expected from the used amount. Moreover, economic disadvantage arises and physical properties of adhesion may be adversely affected. From the standpoint of the effect of the radical scavenger, the physical properties of adhesion and the economy, it is preferable that the amount of the radical scavenger is in the range of 0.05 to 5 parts by weight and more preferably in the range of 0.1 to 2 parts by weight.
When an antioxidant is used as the radical scavenger of component (F), a polymerizable antioxidant may be used in a manner such that the polymerizable antioxidant is copolymerized in the preparation of the copolymer of (meth)acrylic esters of component (D) or the copolymer of (meth)acrylic esters in component (D′) so that the unit of the polymerizable antioxidant is incorporated into the prepared copolymer. In this case, the content of the unit of the polymerizable antioxidant is selected, in general, in the range of 0.01 to 10 parts by weight, preferably in the range of 0.05 to 5 parts by weight and most preferably in the range of 0.1 to 2 parts by weight per 100 parts by weight of the total amount of component (D) or component (D′). By incorporating the polymerizable antioxidant into the copolymer, the antioxidant does not easily vaporize and an adhesive composition exhibiting excellent durability can be obtained.
Examples of the polymerizable antioxidant include compounds (a), (b) and (c) having the following structures:
Compound (a) and compound (b) are commercially available as “SUMILIZER GM” [manufactured by SUMITOMO KAGAKU KOGYO Co., Ltd.] and “SUMILIZER GS” [manufactured by SUMITOMO KAGAKU KOGYO Co., Ltd.], respectively.
In adhesive compositions II and II′, a secondary antioxidant may be used as component (G) in combination with the radical scavenger of component (F). When the radical scavenger is used alone, there is the possibility that the radical scavenger itself causes coloring. The secondary antioxidant is used to suppress the coloring.
Examples of the secondary antioxidant include antioxidants containing phosphorus and antioxidants containing sulfur.
Examples of the antioxidant containing phosphorus include trioctyl phosphite, trilauryl phosphite, tristridecyl phosphite, trisisodecyl phosphite, phenyl diisooctyl phosphite, phenyl diisodecyl phosphite, phenyl di(tridecyl) phosphite, diphenyl isooctyl phosphite, diphenyl isodecyl phosphite, diphenyl tridecyl phosphite, triphenyl phosphite, tris(nonylphenyl) phosphite, tris(2,4-di-t-butylphenyl) phosphite, tris(butoxyethyl) phosphite, tetratridecyl 4,4′-butylidenebis(3-methyl-6-t-butylphenol) diphosphite, 4,4′-isopropylidenediphenol alkyl phosphites (the alkyl group having about 12 to 15 carbon atoms), 4,4′-isopropylidenebis (2-t-butylphenol) di(nonylphenyl) phosphite, tris(biphenyl) phosphite, tetra(tridecyl) 1,1,3-tris(2-methyl-5-t-butyl-4-hydroxyphenyl) butane diphosphite, tris(3,5-di-t-butyl-4-hydroxyphenyl) phosphite, hydrogenated 4,4′-isopropylidenediphenol polyphosphite, bis(octylphenyl) bis [4,4′-butylidenebis(3-methyl-6-t-butylphenol)] 1,6-hexanediol diphosphite, hexatridecyl 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenol) diphosphite, tris[4,4′-isopropylidenebis(2-t-butylphenol)] phosphite, tris(1,3-distearoyloxyisopropyl) phosphite, 9,10-dihydro-9-phosphaphenanthrene-10-oxide, tetrakis(2,4-di-t-butylphenyl)-4,4′-biphenylene diphosphonite, distearyl pentaerythritol diphosphite, di(nonylphenyl) pentraerythritol diphosphite, phenyl 4,4,′-isopropylidenediphenol pentaerythritol diphosphite, bis(2,4-di-t-butylphenyl) pentaerythritol diphosphite, bis(2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite and phenylbisphenol-A pentaerythritol diphosphite.
As the antioxidant containing sulfur, it is preferable that dialkyl thiodipropionates and esters of alkylthiopropionic acids with polyhydric alcohols are used. As the dialkyl thiodipropionates, dialkyl thiodipropionates having alkyl groups having 6 to 20 carbon atoms are preferable. As the esters of alkylthiopropionic acids with polyhydric alcohols, esters of alkylthiopropionic having an alkyl group having 4 to 20 carbon atoms with polyhydric alcohols are preferable. In this case, examples of the polyhydric alcohol for forming the ester of a polyhydric alcohol include glycerol, trimethylolethane, trimethylolpropane, pentaerythritol and trishydroxyethyl isocyanurate.
Examples of the dialkyl thiodipropionate include dilauryl thiodipropionate, dimyristyl thiodipropionate and distearyl thiodipropionate. Examples of the ester of an alkylthiopropionic acid with a polyhydric alcohol include glycerol tributylthiopropionate, glycerol trioctylthiopropionate, glycerol trilaurylthiopropionate, glycerol tristearylthiopropionate, trimethylolethane tributylthiopropionate, trimethylolethane trioctylthiopropionate, trimethylethane trilaurylthiopropionate, trimethylolethane tristearylthiopropionate, pentaerythritol tetrabutylthiopropionate, pentaerythritol tetraoctylthiopropionate, pentaerythritol tetralaurylthiopropionate and pentaerythritol tetrastearylthiopropionate.
In the present invention, the secondary antioxidant may be used singly or in combination of two or more. The amount of the secondary antioxidant is selected, in general, in the range of 0.1 to 10 parts by weight per 1 part by weight of the radical scavenger of component (F). When the amount is less than 0.1 part by weight, there is the possibility that the effect of suppressing coloring is not sufficiently exhibited. When the amount exceeds 10 parts by weight, the effect of the secondary antioxidant is not exhibited to the degree expected from the used amount. Moreover, economic disadvantage arises and physical properties of adhesion may be adversely affected. From the standpoint of the effect of suppressing coloring, the physical properties of adhesion and the economy, it is preferable that the amount of the radical scavenger is in the range of 0.5 to 5 parts by weight and more preferably in the range of 1 to 2 parts by weight per 1 part by weight of the radical scavenger.
The adhesive compositions II and II′ 0 of the present invention may further comprise various additives conventionally used for adhesive compositions such as plasticizers, silane coupling agents and ultraviolet light absorbents as long as the objects of the present invention are not adversely affected, where desired, When adhesive compositions II and II′ of the present invention having the above compositions are applied to easily hydrolyzable materials, degradation of the materials by hydrolysis is suppressed and, in particular, durability under the environment of a high temperature and a high humidity can be improved. Therefore, it is advantageous that the adhesive compositions of the present invention are applied to films of acetyl cellulose which are easily hydrolyzed.
When adhesive compositions I, II and II′ are used for optical components, it is advantageous that the compositions transmit light.
In the present invention, a layer comprising any of adhesive compositions I, II and II′ (referred occasionally to as an adhesive layer, hereinafter) can be disposed at least on one face of a substrate and the obtained laminate can be used as an adhesive sheet. Examples of the substrate include paper substrates such as glassine paper, coated paper and cast paper; laminate papers obtained by laminating thermoplastic resins such as polyethylene on the paper substrates; polyester films such as films of polyethylene terephthalate, polybutylene phthalate and polyethylene naphthalate; polyolefin films such as films of polypropylene and polymethylpentene; plastic films such as films of polycarbonate and cellulose acetate; and laminate sheets containing these films. The substrate is suitably selected in accordance with the application of the adhesive sheet.
The above adhesive sheet can be used for transferring the adhesive layer to an adherend or as a component stuck to a desired adherend. When the adhesive sheet is used in the former application, in general, a substrate sheet is coated with a release agent such as a silicone resin. In this case, the thickness of the substrate sheet is not particularly limited. In general, the thickness is 20 to 150 μm.
When the adhesive sheet is used in the latter application, the type and the thickness of the substrate are suitably selected in accordance with the application. A conventional release sheet may be disposed on the adhesive layer, where desired.
In the above adhesive sheets, the thickness of the adhesive layer is, in general, about 5 to 150 μm and preferably about 10 to 90 μm.
The adhesive optical components I and II of the present invention comprises an optical component and a layer which comprises any of adhesive compositions I, II and II′ and is disposed at least on one face of the optical component.
Preferable examples of the above optical component include polarizing plates and plates for phase differentiation each having a TAC film. Examples of the above polarizing plates include polarizing plates used for liquid crystal display apparatuses, for adjustment of quantity of light, for apparatuses using interference of polarized light and for optical detectors of defects.
As the application of adhesive optical components I and II of the present invention, in particular, it is preferable that the layers comprising adhesive compositions I, II and II′ are disposed on polarizing plates and plates for phase differentiation for liquid crystal cells in liquid crystal display apparatuses.
When the adhesive composition I of the present invention is applied to easily hydrolyzable materials, degradation of the materials by hydrolysis can be suppressed and durability can be improved. Therefore, when the adhesive composition is applied to polarizing plates and plates for phase differentiation for liquid crystal cells, hydrolysis of the TAC film disposed in the plates is suppressed and, in particular, durability under the environment of a high temperature and a high humidity can be improved.
Adhesive compositions II and II′ provide excellent stress relaxation without plasticizers. Moreover, when the compositions are applied to easily hydrolyzable materials, adhesive optical components having excellent qualities can be provided since degradation of the materials by hydrolysis can be suppressed and degradation of the adhesive compositions themselves can also be suppressed.
EXAMPLES
The present invention will be described more specifically with reference to examples in the following. However, the present invention is not limited to the examples.
Example 1
Into 200 parts by weight of toluene, 100 parts by weight of a copolymer of acrylic esters having a weight-average molecular weight of 1,200,000 (the unit of butyl acrylate: 97% by weight and the unit of acrylic acid: 3% by weight), 0.05 parts by weight of an adduct of trimethylolpropane and tolylene diisocyanate as the crosslinking agent and 0.5 parts by weight of 2,6-di-tert-butyl-p-cresol as the phenol derivative were added and a solution of an adhesive was prepared.
A substrate of a polyethylene terephthalate film having a thickness of 38 μm which was coated with a silicone resin on one face [manufactured by LINTEC Corporation; the trade name: SP PET38] was coated with the solution of an adhesive prepared above on the face coated with a silicone resin. The substrate coated with the solution of an adhesive was dried at 100° C. for 1 minute and an adhesive sheet having an adhesive layer having a thickness of 30 μm was prepared.
The prepared adhesive sheet was laminated to one face of a TAC film having a thickness of 80 μm in a manner such that the adhesive layer was attached to the TAC film. The obtained laminate was aged at the ordinary temperature for one week and an adhesive optical component having a length of 80 mm and a width of 150 mm was prepared.
The substrate on the adhesive optical component prepared above was removed and the remaining adhesive optical component was stuck to a glass substrate via the exposed adhesive layer.
The obtained product was subjected to the durability tests under the condition of a high temperature and under the condition of a high temperature and a high humidity shown below and the properties were evaluated. No degradation of the TAC film was confirmed. No lifting or peeling from the glass substrate was found.
<Evaluation of the Properties of the Optical Component>
The durability tests were conducted under a condition of a high temperature of 100° C. and dry and under a condition of a high temperature of 80° C. and a high humidity of 90% RH. The degradation of the TAC film (turbidity and coloring) and lifting and peeling from the glass substrate were visually observed and the properties of the optical component were evaluated.
Examples 2 to 7
Optical components were prepared and the properties were evaluated in accordance with the same procedures as those conducted in Example 1 except that compounds shown in Table 1 were used in amounts shown in Table 1 as the phenol derivative in place of 2,6-di-tert-butyl-p-cresol. The results are shown in Table 1.
In Table 1, the phenol derivatives are abbreviated as shown in the following:
C-1: butylhydroxyanisole C-2: stearyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate C-3: 4,4′-butylidenebis(3-methyl-6-tert-butylphenol) C-4: 3,6-dioxaoctamethylenebis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate] C-5: 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane C-6: tetrakis[methylene-3-(3′,5′-di-tert-butyl-4′-hydroxyphenyl) propionate]methane
TABLE 1
Phenol
Evaluation
derivative
of properties
amount
high temperature
type
(part by wt.)
high temperature
and high humidity
Example 2
C-1
1.5
good
good
Example 3
C-2
2.0
good
good
Example 4
C-3
0.5
good
good
Example 5
C-4
0.5
good
good
Example 6
C-5
0.5
good
good
Example 7
C-6
0.5
good
good
Note:
good means that no degradation of a TAC film was confirmed and no lifting or peeling from a glass substrate was formed.
Example 8
Into 300 parts by weight of toluene, 100 parts by weight of the copolymer of acrylic esters which was used in Example 1, 50 parts by weight of a homopolymer of butyl acrylate having a weight-average molecular weight of 50,000, 0.05 parts by weight of an adduct of trimethyloloropane and tolylene diisocyanate as the crosslinking agent and 0.5 parts by weight of 2,6-di-tert-butyl-p-cresol as the phenol derivative were added and a solution of an adhesive was prepared.
Subsequently, the same procedures as those conducted in Example 1 were conducted. Under the condition of a high temperature and a high humidity, no degradation of the TAC film was confirmed and no lifting or peeling from the glass substrate was found.
Example 9
A solution of an adhesive was prepared in accordance with the same procedures as those conducted in Example 1 except that 0.05 parts by weight of γ-glycidoxypropyltrimethoxysilane, which is a silane coupling agent, was further added.
Subsequently, the same procedures as those conducted in Example 1 were conducted. Under the condition of a high temperature and a high humidity, no degradation of the TAC film was confirmed and no lifting or peeling from the glass substrate was found.
Comparative Example 1
The same procedures as those conducted in Example 1 were conducted except that 2,6-di-tert-butyl-p-cresol was not added. In the durability tests under the condition of a high temperature and under the condition of a high temperature and a high humidity, the TAC film became turbid under the condition of a high temperature and a high humidity and peeling from the glass substrate took place under the condition of a high humidity.
Example 10
Into 200 parts by weight of toluene, 100 parts by weight of a copolymer of acrylic esters having a weight-average molecular weight of 1,200,000 (the unit of butyl acrylate: 97% by weight and the unit of acrylic acid: 3% by weight), 0.05 parts by weight of an adduct of trimethyloipropane and modified tolylene diisocyanate as the crosslinking agent and 0.1 part by weight of 2,6-di-tert-butyl-p-cresol as the radical scavenger of a phenolic antioxidant were added and a solution of an adhesive was prepared.
A release sheet of a polyethylene terephthalate film having a thickness of 38 μm which was coated with a silicone resin on one face [manufactured by LINTEC Corporation; the trade name: SP PET38] was coated with the solution of an adhesive prepared above on the face coated with a silicone resin. The release sheet coated with the solution of an adhesive prepared above was dried at 100° C. for 1 minute and an adhesive sheet having an adhesive layer having a thickness of 30 μm was prepared.
The prepared adhesive sheet was laminated to one face of a polarizing plate having a three-layer laminate structure composed of a film of triacetylcellulose, a film of polyvinyl alcohol and a film of triacetylcellulose laminated in this order in a manner such that the layer of the adhesive was attached to the polarizing plate. The obtained laminate was aged at the ordinary temperature for one week and an adhesive optical component having a length of 80 mm and a width of 150 mm was prepared.
The release sheet on the adhesive optical component prepared above was removed and the remaining adhesive optical component was stuck to both faces of a glass plate for a liquid crystal cell via the exposed adhesive layer so that an orthogonal Nicol was formed.
The properties of the obtained optical component was evaluated in accordance with the methods described in the following. The results of the evaluation are shown in Table 2.
<Evaluation of the properties of the optical component>
The durability tests were conducted under the condition of a high temperature of 100° C. and dry for 1,000 hours and under the condition of a high temperature of 80° C. and a high humidity of 90% RH for 1,000 hours.
The results were evaluated as follows:
(1) Resistance of a TAC Film to Hydrolysis
The condition of degradation (turbidity and coloring) of a TAC film was evaluated by visual observation. When no lifting or peeling was found, the resistance to hydrolysis was evaluated as good. When lifting and peeling were found, the resistance to hydrolysis was evaluated as poor.
(2) Durability (Resistance of an Adhesive to Degradation)
The presence or the absence of lifting and peeling of an optical component from a glass plate was visually observed. When no lifting or peeling was found, the durability was evaluated as good. When lifting and peeling were found, the durability was evaluated as poor.
(3) Effect of Suppressing Difference in Brightness
Difference in brightness at peripheral portions and at inner portions (the picture frame phenomenon) of a polarizing plate was visually observed. When no picture frame phenomenon, i.e., no difference in brightness, was found, the effect of suppressing difference in brightness was evaluated as good. When the picture frame phenomenon, i.e., the difference in brightness, was found, the effect of suppressing difference in brightness was evaluated as poor.
(4) Resistance to Coloring of an Adhesive
An adhesive layer was formed on a polarizing plate and the resultant laminate was stuck to a glass plate. The obtained optical component was placed under the condition of a high temperature of 100° C. and dry for 1,000 hours or under the condition of a high temperature of 800° C. and a high humidity of 90% RH for 1,000 hours. The change in color of the optical component was obtained by the measurement of the degree of yellowing (b*) and the degree of redding (c*) in accordance with the method of Japanese Industrial Standard K 7103 using a color difference meter [manufactured by NIPPON DENSHOKU Co., Ltd.; SQ-2000]. The resistance to coloring was evaluated in accordance with the following criteria:
good: a change smaller than 0.5 fair: a change of 0.5 or greater and smaller than 1.0 poor: a change of 1.0 or greater
Example 11
An optical component was prepared and evaluated in accordance with the same procedures as those conducted in Example 10 except that 0.1 part by weight of an antioxidant containing phosphorus which was a 4,4′-isopropylidenediphenol alkyl phosphite [manufactured by ASAHI DENKA KOGYO Co., Ltd.; the trade name: ADEKASTAB 1500] was further added as the secondary antioxidant. The results are shown in Table 2.
Example 12
An optical component was prepared and evaluated in accordance with the same procedures as those conducted in Example 10 except that 25 parts by weight of a homooligomer of butyl acrylate having a weight-average molecular weight of 4,000 (Mw/Mn=1.5) and 0.05 parts by weight of the antioxidant containing phosphorus used in Example 11 [ADEKASTAB 1500] were further added. The results are shown in Table 2.
Example 13
An optical component was prepared and evaluated in accordance with the same procedures as those conducted in Example 12 except that 0.05 parts by weight of an antioxidant containing sulfur which was dimyristyl thiodipropionate [manufactured by ASAHI DENKA KOGYO Co., Ltd.; the trade name: ADEKASTAB AO-503A] was used in place of the antioxidant containing phosphorus “ADEKASTAB 1500”. The results are shown in Table 2.
Example 14
An optical component was prepared and evaluated in accordance with the same procedures as those conducted in Example 10 except that 25 parts by weight of a homooligomer of butyl acrylate having a weight-average molecular weight of 10,000 (Mw/Mn=1.6) was further added and 0.1 part by weight of a phenolic antioxidant [manufactured by SUMITOMO KAGAKU KOGYO Co., Ltd.; the trade name: SUMILIZER GS] was used in place of 0.1 part by weight of 2,6-di-t-butyl-p-cresol. The results are shown in Table 2.
Example 15
An optical component was prepared and evaluated in accordance with the same procedures as those conducted in Example 14 except that 0.05 parts by weight of an amine photostabilizer which was tetrakis(2,2,6,6-tetramethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate [manufactured by ASAHI DENKA KOGYO Co., Ltd.; the trade name: ADEKASTAB LA-57] was used in place of 0.1 part by weight of the phenolic antioxidant “SUMILIZER GS”. The results are shown in Table 2.
Example 16
An optical component was prepared and evaluated in accordance with the same procedures as those conducted in Example 15 except that 0.05 parts by weight of an antioxidant containing phosphorus which was bis(2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite [manufactured by ASAHI DENKA KOGYO Co., Ltd.; the trade name: ADEKASTAB PEP-36] was further added. The results are shown in Table 2.
Example 17
An optical component was prepared and evaluated in accordance with the same procedures as those conducted in Example 10 using 100 parts by weight of a copolymer of acrylic esters having a weight-average molecular weight of 1,200,000 (the unit of butyl acrylate: 96.9% by weight, the unit of acrylic acid: 3% by weight and the unit of a polymerizable phenolic antioxidant [manufactured by SUMITOMO KAGAKU KOGYO Co., Ltd.; the trade name: SUMILIZER GM]: 0.1% by weight), 25 parts by weight of a homooligomer of butyl acrylate having a weight-average molecular weight of 10,000, 0.05 parts by weight of an adduct of trimethylolpropane and modified tolylene diisocyanate and 0.05 parts by weight of the antioxidant containing phosphorus “ADEKASTAB 1500” which was used above. The results are shown in Table 2.
Example 18
An optical component was prepared and evaluated in accordance with the same procedures as those conducted in Example 10 except that 0.5 parts by weight of hydroquinone which was a polymerization inhibitor was used in place of 0.1 part by weight of 2,6-di-t-butyl-p-cresol. The results are shown in Table 2.
Comparative Example 2
An optical component was prepared and evaluated in accordance with the same procedures as those conducted in Example 10 except that 2,6-di-t-butyl-p-cresol was not used. The results are shown in Table 2.
Comparative Example 3
An optical component was prepared and evaluated in accordance with the same procedures as those conducted in Example 12 except that either 2,6-di-t-butyl-p-cresol or the antioxidant containing phosphorus “ADEKASTAB 1500” was not used. The results are shown in Table 2.
TABLE 2
Evaluation of properties of optical component
effect
resistance
of suppressing
resistance to
to hydrolysis of
difference in
coloring of
TAC film
durability
brightness
adhesive
Example 10
good
good
good
fair
Example 11
good
good
good
good
Example 12
good
good
good
good
Example 13
good
good
good
good
Example 14
good
good
good
good
Example 15
good
good
good
fair
Example 16
good
good
good
good
Example 17
good
good
good
good
Example 18
good
good
good
fair
Comparative
poor
poor
good
good
Example 2
Comparative
poor
poor
poor
good
Example 3
In Examples 10 to 18, the resistance to hydrolysis of a TAC film, the durability and the effect of suppressing difference in brightness were good. In Examples 11 to 14, 16 and 17, the resistance to coloring of an adhesive was good. In Example 14, although the phenolic antioxidant was used alone without secondary antioxidants, the resistance to coloring of an adhesive was good since the specific antioxidant causing little coloring was used. In Example 17, the polymerizable antioxidant was used as the phenolic antioxidant and introduced into the copolymer of acrylic esters by copolymerization. The optical component exhibiting excellent properties could be obtained.
In contrast, in Comparative Examples 2 and 3, hydrolysis of the TAC film took place and coloring of the film was observed since no antioxidants were added. Portions of the adhesive optical component were peeled from the glass plate. In Comparative Example 3, the difference in brightness was found in the polarizing plate. | An adhesive sheet including an adhesive composition disposed on at least one face of a film of acetyl cellulose, the adhesive sheet being produced by coating a solution of the adhesive composition on the face of the film and drying the solution to form a laminate, the adhesive composition containing (A) a copolymer of (meth)acrylic esters,(B) a crosslinking agent and (C) a phenol compound. The adhesive composition in the adhesive sheet serves to suppress degradation of easily hydrolyzable materials by hydrolysis, improve durability and provides excellent stress relaxation without using plasticizers. | 2 |
CROSS-REFERENCE TO THE RELATED APPLICATIONS
This application is a continuation-in-part of copending application Ser. No. 104,099, filed Oct. 5, 1987, the contents of which are incorporated herein by reference as if set out in full.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to the field of purifying fluid streams by the removal of at least sulfur compounds therefrom. More particularly, the present invention relates to new and integrated processes which involve the utilization of a primary adsorption bed containing a regenerable, physical adsorbent and an auxiliary sorption bed containing a chemisorbent for the removal of sulfur compounds from the fluid stream, which processes provide for higher yields and product purity while at the same time generally require less energy consumption and/or capital costs.
2. Discussion of Related Art
The removal of sulfur compounds, particularly hydrogen sulfide, carbonyl sulfide and alkyl mercaptans from hydrocarbon streams is desirable for many reasons, depending in part upon the intended use of the final sweetened product. Since a very large percentage of the lighter hydrocarbons in liquid streams are ultimately used as fuel per se, the presence of sulfur compounds is objectionable because of the safety factors and corrosion problems associated with such compounds and the unpleasant odor imparted and the air pollution resulting from the combustion thereof. When used as fuels for internal combustion engines, the sulfur compounds are deleterious to the effectiveness of known octane improvers such as tetraethyllead. The hydrocarbon streams are also generally subjected to hydrocarbon conversion processes in which the conversion catalysts are, as a rule, highly susceptible to poisoning by sulfur compounds.
So too, the tremendous increase in demand for natural gas in recent years has made the gas producers far more dependent on "sour" gas fields than ever before. As used herein, a "sour" gas is defined as a gas containing mercaptans and/or hydrogen sulfide. "Sweetening" is defined as the removal of the mercaptans and hydrogen sulfide from a gas or liquid stream. Formerly, when a gas well came in "sour", it was capped off because the supply and demand situation did not permit its purification. Recently, however, these capped wells have been put into production and are being utilized regardless of their hydrogen sulfide and mercaptan content.
Several methods for sweetening hydrocarbons streams have been proposed and utilized in the past, including both chemical and physical techniques.
The chemical processes have involved purely chemical reactions such as scrubbing with mono- or diethanolamine or countercurrent extraction using a hot potassium carbonate solution, and chemisorption methods in which iron oxide sponge or zinc oxide reacts with the sulfur compounds to form iron sulfide and zinc sulfide, respectively.
A widely used chemical system for treating natural gas streams involves scrubbing with mono- or diethanolamine. The natural gas is passed through the amine solution which absorbs the hydrogen sulfide. The solution from the absorption equipment is passed to a stripping column where heat is applied to boil the solution and release the hydrogen sulfide. The lean, stripped solution is then passed to heat exchangers, and returned to the absorption equipment to again absorb hydrogen sulfide gas. The principle disadvantages of the amine system are its high operating cost, the corrosive nature of the absorbing liquid, its inability to remove mercaptans and water from gas streams, as well as its general inability to selectively remove hydrogen sulfide from carbon dioxide.
Another prior art system is the iron sponge method of purifying natural gas, utilizing iron oxide impregnated wood chips in a packed bed. The gaseous mixture containing hydrogen sulfide and/or mercaptans contacts a packed bed of iron oxide sponge, preferably chemically absorbing the sulfur impurities on the exposed iron oxide surface. A major disadvantage of this method of sweetening natural gas is that the fusion of iron sponge particles with sulfur frequently causes a high pressure drop through the bed. Moreover, the operational cost is high because the adsorbent must be replaced frequently. Finally, the iron sulfide is pyrophoric and thus presents serious problems with the disposal of the used iron oxide.
Hydrogen sulfide has also been removed from natural gas by countercurrent extraction with a hot potassium carbonate solution. In such a system, as in the amine system discussed above, both hydrogen sulfide and carbon dioxide are removed by chemically combining with potassium carbonate and later released by stripping with steam. Generally, significant disadvantages of this method of sweetening natural gas are that an amine system must follow the potassium carbonate system to remove the final traces of the sulfur compounds such as hydrogen sulfide and the non-selectivity for removing the hydrogen sulfide from the carbon dioxide.
Zinc oxide has also been used for removing sulfur compounds frmm hydrocarbon streams. However, its high cost and substantial regeneration costs make it generally uneconomical to treat hydrocarbon streams containing an appreciable amount of sulfur compound impuritie on a volume basis. So too, the use of zinc oxide and other chemisorption materials similar to it disadvantageously generally require the additional energy expenditure of having to heat the sulfur containing fluid stream prior to its being contacted with the stream in order to obtain a desirable sulfur compound loading characteristic.
Selective physical adsorption of sulfur impurities on crystalline zeolitic molecular sieves is a widely used method. Both liquid phase and vapor phase processes have been developed. As used herein, a "physical adsorbent" is an adsorbent which does not chemicall react with the impurities that it removes.
A typical hydrocarbon sweetening process comprises passing a sulfur-containing hydrocarbon stream through a bed of a molecular sieve adsorbent having a pore size large enough to adsorb the sulfur impurities, recovering the non adsorbed effluent hydrocarbon until a desired degree of loading of the adsorbent with sulfur-containing impurities is obtained, and thereafter purging the adsorbent mass of hydrocarbon and regenerating the adsorbent by desorbing the sulfur containing compounds therefrom.
The adsorbent regenerating operation is conventionally a thermal swing or combined thermal and pressure swing type operation in which the heat input is supplied by a hot gas substantially inert toward the hydrocarbons, the molecular sieve adsorbents and the sulfur-containing adsorbate. When treating a hydrocarbon in the liquid phase, such as propane, butane or liquified petroleum gas (LPG), natural gas is ideally suited for use in purging and adsorbent regeneration, provided that it can subsequently be utilized in situ as a fuel wherein it constitutes an economic balance against its relatively high cost. Frequently, however, the sweetening operation requires more natural gas for thermal-swing regeneration than can advantageously be consumed as fuel, and therefore, constitutes an inadequacy of the regeneration gas. The result is a serious impediment to successful design and operation of sweetening processes, especially when desulfurization is carried out at a location remote from the refinery, as is frequently the case.
But even when treating a hydrocarbon in the gaseous phase with a physical adsorbent such as crystalline zeolitic molecular sieves, a purge gas must still be provided to regenerate the sulfur compound laden adsorbent, involving the same disadvantages noted above when using a liquid phase hydrocarbon stream. Generally, a product slip-stream from an adsorbent bed in the adsorption mode is utilized as the desorption gas for regenerating a used bed. The utilization of this product gas for regeneration purposes during the entire adsorption cycle disadvantageously reduces the final product yield. Moreover, it is generally difficult to get complete sulfur-compound removal when utilizing such a physical adsorbent.
A need consequently exists to provide a process for removing sulfur-compounds from a liquid or gaseous stream which process is more economical and efficient than the prior art techniques discussed above.
SUMMARY OF THE INVENTION
Applicants have discovered processes for removing at least sulfur compounds from a fluid stream which eliminates or substantially avoids all of the disadvantages noted above.
More particularly, Applicants' processes involve a totally new approach to the use of sorbents for removing sulfur compounds from a fluid stream which involves the integration of two types of sorbent beds, namely, a physical adsorbent and a chemisorbent, to arrive at a combination which is more efficient and economical than the use of either type of sorbent alone.
By virtue of this invention, the advantages of using each type of sorbent are retained while the disadvantages are substantially reduced or eliminated. This results in a process which involves less capital costs and lower operating costs while simultaneously providing a high yield of treated fluid at even greater purity.
More specifically, by studying curves plotting cycle time versus the sulfur compound concentration in the adsorption effluent and regeneration effluent, respectively, of an adsorbent bed containing regenerable, physical adsorbent, Applicants recognized that there were defined regions within the overall adsorption cycle which suggested that the conventional means of running the adsorber on the adsorption and regeneration modes might advantageously be changed. By integrating these primary physical adsorbent beds with auxiliary sorbent beds which utilize chemisorbents, Applicants have discovered that they can actually take advantage of the defined regions that they were able to recognize in the cycle plots and arrive at the present invention.
In general, the integrated process of the present invention comprises passing a fluid stream containing at least sulfur compound impurities through a primary adsorbent bed containing an adsorbent capable of physically adsorbing the sulfur compound impurities which adsorbent bed is in the adsorption mode, and withdrawing an adsorption effluent substantially free of sulfur compound impurities. A portion of this adsorption effluent, or some other suitable gas, is desirably heated and used as a regeneration medium to regenerate another primary adsorption bed containing sulfur compound-laden adsorbent which is in the desorption mode.
The regeneration effluent leaving the adsorbent bed undergoing regeneration is allowed to leave the overall process and is utilized as fuel, flared, or the like.
This flow scheme continues until the sulfur compound concentration within the regeneration effluent progressively increases to a maximum peak value and then proggressively decreases to a substantially lower value. At this point in the cycle, the regeneration effluent is now recovered by passing it to an auxiliary sorber containing chemisorbent which is selective for the sorption of sulfur compounds which may still be present in this regeneration effluent. A treated regeneration effluent is provided which is substantially free of sulfur compounds. This treated regeneration effluent may then be combined with the adsorption effluent to form the product stream.
This second phase of the cycle is continued until there begins to be a breakthrough of sulfur compounds in the adsorption effluent. At this time, the third phase of the cycle begins in which the adsorption effluent, now containing a predetermined concentration of sulfur compounds which is advantageously higher than that required to be in the ultimate product, is introduced into the auxiliary sorber so as to produce a product stream substantially free of sulfur compounds. At the same time, once this third phase of the cycle begins, the portion of the adsorption effluent entering the primary adsorber in the regeneration mode, or the other suitable gas used as a regeneration medium, is no longer heated so as to cool this bed in preparation for its subsequent adsorption mode. The adsorption cycle is complete when the amount of sulfur compound concentration within the adsorption effluent exceeds a predetermined value.
In an alternative embodiment of the present invention, in which the amount of water vapor present in the product stream must be kept to a minimum, the cycle scheme discussed above may be altered so as to minimize, or substantially eliminate, such water vapor content in the product.
This water vapor may originate from the fluid feed stream and/or may be formed in the auxiliary sorber, if zinc oxide is the sorbent employed, wherein zinc oxide reacts with hydrogen sulfide to form zinc sulfide and water.
Thus, in this alternative embodiment, as in the previous embodiment, the fluid feed stream containing at least sulfur compound impurities is passed through the primary adsorbent bed containing an adsorbent which is capable of physically adsorbing the sulfur compound impurities and any water vapor that may be present in the fluid feed stream such that an adsorption effluent is withdrawn which is substantially free of sulfur compound impurities and water vapor.
As in the embodiment discussed above, a portion of the adsorption effluent, or some other suitable gas, is then desirably heated and used as a regeneration medium to regenerate another primary adsorption bed containing sulfur compound-laden, and possibly water vapor-laden, adsorbent which is in the desorption mode.
The regeneration effluent leaving the adsorbent bed undergoing regeneration is also allowed to leave the overall process, as in the previous embodiment, and utilized as fuel, flared, or the like. The flow scheme continues until the sulfur compound concentration within the regeneration effluent progressively increases to a maximum peak value and then progressively decreases to a substantially lower value. At this point in the cycle, the regeneration effluent is now recovered. However, unlike the previous embodiment in the which the regeneration effluent is passed to the auxiliary sorber for removal of sulfur compounds which may still be present, in this embodiment, the regeneration effluent is recombined with the feed stream and passed through the primary adsorber once again. This is done to remove water vapor which may be present in the regeneration effluent derived from the adsorbent that is being regenerated.
In this alternative embodiment, the hot regeneration effluent must be cooled so as to condense and then remove as much water as possible such that there is no water buildup in the system caused by the recycling of the regeneration effluent. Advantageously, it is preferably indirectly heat-exchanged with the relatively cooler adsorption effluent so that the adsorption effluent is heated prior to its entering the auxiliary sorber.
This mode of operation continues until the water vapor concentration within the regeneration effluent is no higher than desired or, alternatively, has passed the maximum peak value and has progressively decreased to a substantially constant value. At this point in the cycle, the regeneration effluent, now no longer containing any appreciable amount of water vapor, may be directly passed to the auxiliary sorber as in the second phase of the embodiment discussed above. The remaining phases of the cycle are then carried out in a manner substatially the same as in the earlier embodiment. Of course, if desired, the recycle of the regeneration effluent to the feed stream may be continued for the entire cycle. The adsorption effluent is desirably passed to the auxiliary sorber at least as early as the beginning of sulfur compound breakthrough from the primary adsorber.
If zinc oxide is utilized in the auxiliary sorber as the chemisorbent, the sorber may optionally also contain an adsorbent that is capable of adsorbing water, particularly water that is generated by the zinc oxide reaction. Such adsorbent is generally located in the auxiliary sorber such that it is the last sorbent that the fluid stream passes through prior to exiting the sorber at its discharge end.
As a result of this integration of the primary and auxiliary sorbers containing their respective disparate sorbents, one of the primary advantages obtained is the ability to use less of the physical adsorbent in the primary adsorber than would ordinarily be required. Although at first, this reduction in the amount of adsorbent in the primary adsorber might not seem unusual inasmuch as an auxiliary sorber is also being utilized in the present invention, what is surprising and clearly advantageous is that the amount of the reduction of such adsorbent inventory is much more than would be expected.
Thus, by allowing sulfur compounds to break through in the adsorber effluent instead of trying to remove essentially all of the sulfur compounds in the primary adsorber bed, as has been true with the prior art, the amount of adsorbent reduction is advantageously much greater than the proportional amount of reduction in sulfur loading. In other words, if, for example, the sulfur load were reduced by about 20%, it would be expected that the amount of adsorbent in the adsorber would correspondingly be reduced by a similar amount. In contrast, however, a substantially greater reduction in adsorbent inventory is realized, i.e., the amount of adsorbent is generally reduced by about 20 to 70% depending upon the inlet feed conditions and the amount of sulfur breakthrough allowed, with its concomitant increase in savings.
Moreover, by reducing the amount of adsorbent present in the primary adsorbers, there is less adsorbent that is required to be regenerated. As such, less purge gas is required for regeneration and less energy is required to heat the bed being regenerated to the proper desorption conditions.
Still further, the integrated processes of the present invention also offer a novel method for heating the chemisorbent in the auxiliary sorbers whose sulfur compound loading capacity generally increases as its temperature is increased. Thus, in contrast to conventional techniques, the process of the present invention takes advantage of the heat that is present in the hot regeneration effluent and effectively and advantageously utilizes this heat to raise the temperature of the chemisorbent in the auxiliary sorber thereby greatly decreasing the energy requirements that would otherwise have to be supplied for such a heating step.
Of course, by realizing that the sulfur compound peak appears early in the regeneration effluent during the regeneration cycle and recovering the regeneration effluent once this peak has passed, yet an additional advantage is obtained which is in contrast to the prior art wherein none of the regeneration effluent is recovered and utilized as product stream.
Still further, by combining the sulfur removal effects of the physical adsorbent contained within the primary adsorber and the chemisorbent contained within the auxiliary sorber, and integrating these two types of sorbers in the manner discussed herein, a greater product purity is able to be obtained than is generally possible when using the physical adsorbent alone. So too, where the amount of water vapor present in the product is critical, the integrated processes of the present invention are able to provide a product which is substantially devoid of such water vapor.
Finally, and perhaps most importantly, the overall integrated processes of the present invention generally provide a more attractive economical system when considering such factors as operating costs and initial capital installation costs for the treatment of a particular fluid stream as contrasted to the use of either of the sorbents contained within the primary or auxiliary sorbers alone for the treatment of the same fluid streams and, in general, are even more economically attractive than the use of an amine scrubbing solution particularly when the cost for subsequently removing mercaptans are also included.
The present invention provides for a unique, simple and elegant method for removing sulfur compounds from a fluid streams in a most economical and efficient manner.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph which sets forth curves of hydrogen sulfide concentration in the regeneration effluent and in the adsorption effluent, respectively, as a function of cycle time; a curve of water concentration in the regeneration effluent as a function of cycle time; and a curve of the regeneration effluent temperature as a function of cycle time for a typical adsorption cycle in an adsorber containing a physical adsorbent.
FIG. 2, which comprises FIGS. 2A, 2B, 2C, and 2C', shows a series of schematic flow sheets showing the flow of the fluid stream as it is being treated in one embodiment of the integrated process of the present invention during the various phases thereof. FIG. 2C' is an alternative embodiment of FIG. 2C.
FIG. 3 is a graph showing the effect of hydrogen sulfide concentration in the effluent leaving an adsorbent bed (the amount of breakthrough) for a particular feedstream composition and inlet conditions on the overall capital cost of an integrated molecular sieve/zinc oxide system of the present invention.
FIG. 4 is a graph showing the effect of hydrogen sulfide breakthrough from the primary adsorber for a particular feedstream composition and inlet conditions on the amount of regeneration gas required for regenerating the adsorbent beds in an integrated molecular sieve/zinc oxide system of the present invention.
FIG. 5 is a graph showing the effect of hydrogren sulfide breakthrough on the overall energy requirements of an integrated molecular sieve/zinc oxide system of the present invention for a particular feedstream composition and inlet conditions.
FIG. 6 is a graph showing the effect of hydrogen sulfide breakthrough on the amount of regeneration gas that is to be flared in an integrated molecular sieve/zinc oxide system of the present invention for a particular feedstream composition and inlet conditions.
FIG. 7 is a schematic flow sheet showing a supplemental phase of the cycle of the present invention in an alternative embodiment in which the amount of water in the product stream is critical.
FIG. 8 is a further embodiment of FIG. 7 which provides for the regeneration of adsorbent contained within the auxiliary sorber.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, a number of curves are shown for a conventional adsorption cycle in which 140 million standard cubic feet per day (hereinafter "MMSCFD") of natural gas are treated in an adsorption bed containing zeolite molecular sieve selective for the removal of sulfur compounds, particularly hydrogen sulfide in this exemplary case. The feed is introduced to the adsorber at 100° F. and at a pressure of 1150 psig having an inlet hydrogen sulfide concentration of about 150-190 parts per million on a volume basis (hereinafter "PPMV") and a water vapor concentration of about 20 to 1000 parts per million on a volume basis. As is shown, the time for a complete cycle of the adsorption process is 300 minutes.
As the natural gas flows through a newly regenerated bed from a previous cycle, an adsorption front of hydrogen sulfide is established at the inlet end of the adsorber. As adsorption continues, this front moves progressively towards the outlet end of the adsorber. As is seen from curve B, which shows the amount of hydrogen sulfide present in the adsorption effluent, it is generally not until the latter part of the cycle is reached, that hydrogen sulfide begins to break through the outlet end of the adsorber. In this case, in which a 300 minute cycle is utilized, essentially no hydrogen sulfide appears in the adsorption effluent until about 200 minutes have elapsed into the cycle. Hence, about the first two thirds of the adsorption cycle produces an adsorption effluent with substantially no hydrogen sulfide present. It is only in the final third of the cycle that hydrogen sulfide begins to appear in the adsorption effluent and continues until the final pre-determined hydrogen sulfide concentration is reached, here 10 ppmv, at which point the cycle is ended and the bed is put on a regeneration mode.
Turning to the regeneration of this now impurity-laden bed, curve A plots the amount of hydrogen sulfide appearing in the regeneration effluent as a function of cycle time. It is seen that the hydrogen sulfide concentration peaks very early in the regeneration cycle and then progressively decreases to a substantially constant level of less than about 20 ppmv for the remaining time of the cycle. Hence, essentially only the first third of the regeneration cycle contains a high concentration of hydrogen sulfide in the regeneration effluent. The remaining two thirds of the cycle contains a substantially lower level of hydrogen sulfide.
As is well known to those skilled in the art, the regeneration of a physical adsorbent such as crystalline zeolitic molecular sieve material, generally requires such regeneration to be carried out at elevated temperature. In contrast, in the adsorption mode, the maximum sulfide loading capacity is obtained at lower temperatures. Accordingly, during regeneration, as noted by curve C which sets forth the temperature of the regeneration effluent leaving the adsorber during the regeneration mode as a function of cycle time, it is seen that the bed quickly reaches its desired regeneraiion temperature of about 500° F. and remains at that temperature for the desired period of time at which point cooling begins for the subsequent adsorption mode. Once cooling begins, it quickly brings the temperature of the bed back to the desired temperature of about 120° F.
By virtue of the present invention, Applicants have effectively utilized these phenomena that are occurring during an adsorption cycle to produce an integrated process taking advantage of the fact that there are periods within the cycle in which the hydrogen sulfide concentration in either the regeneration effluent or adsorption effluent is substantially lower than at other times. This effective utilization of these periods of low sulfide concentration in conjunction with the appreciation and recognition that a significant decrease in the amount of adsorbent inventory of a bed containing a physical adsorbent can be realized if the load is slightly decreased, has resulted in the integrated processes of the present invention.
Moreover, Applicants have also utilized curve D of FIG. 1 which sets forth the amount of water present in the regeneration effluent during the cycle, to modify the basic integrated process of the present invention into an alternative embodiment in a manner such that the product stream contains substantially no water by appreciating and recognizing that the amount of water present in the regeneration effluent also rises to a peak value during the cycle and then progressively decreases to a substantially lower value. Thus, by knowing when the water concentration within the regeneration effluent is high and low during the cycle, appropriate changes may be made to the process to provide for a substantially dry product.
Reference is now made to FIG. 2, in which it is shown how the present invention divides the typical adsorption cycle into at least three phases and integrates the physical adsorbent bed with an auxiliary chemisorbent bed to provide the integrated process of the present invention in one embodiment teereof. It is noted that the same reference numerals have been used throughout the FIGS. to designate the same elements.
In FIG. 2A, a fluid feed stream is introduced via line 10 into primary adsorber 100 which contains a physical adsorbent selective for the adsorbent of sulfur compounds within the fluid stream. Adsorption effluent leaving in line 20 is substantially free of such sulfur compounds.
In the preferred embodiment shown in FIG. 2A, about 5 to 30%, preferably about 10 to 20% of the adsorption effluent leaving adsorber 100 is diverted from line 20 to line 30 and utilized as a regeneration medium for primary adsorber 110 which is in a regeneration mode. Adsorber 110 also contains physical adsorbent which is now laden with sulfur compounds from a previous adsorption cycle. Inasmuch as the regeneration of the adsorbent in primary adsorber 110 favors an elevated temperature, it is desirable to heat the adsorbent contained therein in any conventional manner. Preferably, as shown in FIG. 2A, the side stream of adsorption effluent in line 30 is heated in a furnace 140 prior to its being introduced via line 35 into adsorber 110. The regeneration effluent leaves through line 40 and inasmuch as the sulfur compound concentration in this first part of the cycle is very high, as noted in curve A of FIG. 1 discussed above, this portion of the regeneration effluent is allowed to leave this purification system and used either as a fuel, flared, or the like, as is conventional. The adsorption effluent in line 20, as noted above, is substantially free of sulfur compounds and provides the required product stream.
It is noted that the use of the adsorption effluent as the regeneration medium for another bed is not required in the present invention. Indeed, any externally supplied suitable material may be used as the regeneration medium in this phase of the cycle provided that it is capable of removing the sulfur impurities from the sulfur-laden bed without loading the bed with still other impurities and it is substantially inert to both the adsorbent material and the fluid feed stream material. Suitable materials which may be utilized as the regeneration medium include, but are not limited to, inert gases such as nitrogen, argon; fuel-type gases such as natural gas; hydrogen; or a residue gas of natural gas which has had its sulfur impurities and heavy hydrocarbons removed; and the like.
Inasmuch as one of the objectives of the present invention is to recover as much regeneration effluent as possible and ultimately use such recovered effluent as product, the use of an externally provided regeneration medium which is not compatible with the product stream is generally limited to only the first phase of the cycle, as shown in FIG. 2A. The regeneration effluent in this first phase contains a very high amount of sulfur compounds and is removed from the system in any event, whether adsorption effluent is used as the regeneration medium or whether some other material is used, such as nitrogen. Once the regeneration effluent is no longer removed from the system and is instead recovered, as is shown in FIG. 2B, which will be discussed more fully below, the regeneration medium should then desirably be provided from a stream within the purification system itself. Of course, if, for example, natural gas were being treated for the removal of sulfur impurities, the regeneration medium could be provided from an external source throughout the entire cycle if it were to comprise natural gas or a residue gas as defined above since such material would naturally be compatible with the final product.
Turning back to FIG. 2A, it is noted that if the cycle were to be continued in the manner shown in FIG. 2A, it would amount to a conventional adsorption/regeneration cycle in which adsorption effluent would continuously be recovered from adsorber 100 as a product stream and regeneration effluent from adsorber 110 would continuously be removed from the system throughout the entire cycle, thereby disadvantageously losing product yield. But that is where the similarity between the prior art and the present invention ends, as will be shown below.
Still referring to FIG. 2A, vessel 120 is an auxiliary sorber containing chemisorbent, which as discussed above, generally has a better sulfide loading at elevated temperatures. Accordingly, since the adsorption effluent is substantially free of sulfide compounds, it is not necessary to pass this effluent through auxiliary bed 120 for further sulfur compound removal. As such, the relatively low temperature adsorption effluent advantageously does not undesirably cool the sorbent contained within auxiliary bed 120. However, it is understood that the adsorption effluent may nevertheless be passed through the auxiliary bed, if it is so desired, as shown by dotted lines 77 and 79, if the resulting temperature in the auxiliary bed is acceptable or if some other means is provided (not shown) to subsequently or simultaneously heat the bed to a higher temperature.
Thus, as an alternative embodiment of the present invention, which is not shown in FIG. 2A, the hot regeneration effluent leaving primary adsorber 110 at line 40 can be indirectly heat exchanged with the much cooler adsorption effluent contained in line 20 which heated adsorption effluent could then indeed be desirably passed through auxiliary sorber 120 in order to heat the sorbent contained therein. Moreover, if desired, an external heat source may also be provided (not shown) to the heat adsorption effluent in line 33 for subsequent passage into auxiliary sorber 120.
In yet another embodiment of the present invention, also not shown in FIG. 2A, it is also possible to heat the adsorption effluent in line 30 by indirect heat exchange with the hotter regeneration effluent leaving in line 40 prior to the adsorption effluent stream entering furnace 140 thereby decreasing the heating costs associated with operating furnace 140.
When the sulfur compound concentration within the regeneration effluent progressively increases to a maximum value and then progressively decreases to a substantially lower value, the second phase of the cycle begins as illustrated in FIG. 2B.
Essentially the only difference between the flow scheme of Figrre 2A and FIG. 2B is the passing of the regeneration effluent through auxiliary sorber 120. Thus, in contrast to the prior art, from this point on in the adsorption cycle of the present invention, the regeneration effluent leaving primary adsorber 110 is recovered by passing this regeneration effluent through the auxiliary sorber in which sulfur compounds contained within the regeneration effluent are removed. Since the major portion of the hydrogen sulfide or other sulfur impurity such as mercaptans contained within primary adsorber 110 have already been removed in the first phase of this cycle, as noted by curve A of FIG. 1, the remaining sulfur compounds present in the regeneration effluent after this sulfur compound peak has passed, can easily be accommodated on an economical and efficient manner with auxiliary bed 120 from which a treated regeneration effluent emerges in line 50 and desirably combines with the adsorption effluent in line 33 to form the product stream in line 60.
As noted earlier, the adsorption effluent, either in whole or in part, need not be the regeneration medium that is used to regenerate sulfur-laden adsorbent bed 110. While externally provided sources may be used as a regeneration medium, as discussed above, such an externally provided regeneration medium should generally not be employed once the second phase of the cycle begins in which the regeneration effluent is recovered and used as product, unless the externally provided regeneration medium is compatible and acceptably combined with the product stream.
Accordingly, in lieu of such an externally provided regeneration medium, the fluid feed stream from line 10 and/or the product stream in line 60 may be used in whole or in part with or without the adsorption effluent as a regeneration medium for regenerating primary adsorber 110. Any of these streams are perfectly suitable for such regeneration.
Moreover, as in FIG. 2A discussed above, while the adsorption effluent in line 33 is shown in FIG. 2B as by passing auxiliary sorber 120 since the adsorption effluent is still substantially free of sulfide compounds, if desired, it may be passed through auxiliary sorber 120.
This second phase of the adsorption cycle continues until the adsorption front contained within primary adsorber 100 progressively moves toward the outlet end thereof and finally breaks through at which time an increase in sulfur compound concentration appears in the adsorption effluent. The third phase of the cycle is then implemented which is shown in the embodiment of FIG. 2C.
The flow scheme in FIG. 2C is different from that shown in FIG. 2B in essentially two respects. Firstly, the adsorption effluent, now containing sulfur compounds in an amount greater than that required in the product, is passed through auxiliary sorber 120 via lines 33 and 42 to remove these sulfur compounds. So too, in the embodiment shown in FIG. 2C in which the adsorption effluent is used as the regeneration medium, heating of the portion of the adsorption effluent entering adsorber 110 for regeneration purposes is also discontinued by shutting off furnace 140. In this manner, the temperature of the adsorbent contained within adsorber 110 is advantageously cooled in advance of its being put onto an adsorption mode. Of course, such cooling of adsorber 110 would be required regardless of the source of the regeneration medium and any heating of such a regeneration medium other than adsorption effluent would similarly cease in this third phase of the cycle.
In this third phase of the cycle, regeneration effluent still continues to be recovered and treated by being introduced into an auxiliary sorber. In the embodiment shown in FIG. 2C, the same auxiliary sorber is used to treat both the adsorption effluent and the regeneration effluent. However, a plurality of such sorbers may be employed either in series or in parallel including extra sorbers to allow for replacement of used sorbent. Similarly, although only one primary adsorber is depicted in FIG. 2 as being on the adsorption mode and one on the regeneration mode, respectively, it is well known to those skilled in the art that a plurality of such adsorbers may be employed in a manner which is conventional in the art.
A product stream being substantially free of sulfur compounds comprising the treated adsorption effluent and the treated regeneration effluent is then obtained.
In the embodiment shown in FIG. 2C, by combining the regeneration effluent with the substantially colder adsorption effluent in line 42, the temperature of the combined stream entering auxiliary sorber 120 may be low enough such that it undesirably cools the sorbent in auxiliary sorber 120. Accordingly, if desired, it may be advantageous to utilize an indirect heat exchanger (not shown) as a further embodiment of this invention in order to heat the combined stream prior to its entering auxiliary sorber 120.
The third phase of the cycle is complete and adsorption ends when the sulfur compound concentration in the adsorption effluent reaches a pre-determined value, such as 10 ppmv shown in FIG. 1.
As yet a further embodiment of the present invention, because the product stream leaving the auxiliary sorber 120 is substantially devoid of sulfide compounds and since product specifications usually allow for some sulfur compounds to be present in the product streams, say 5 ppmv, it is possible if desired, to by-pass a portion of the adsorption effluent in line 33 around the auxiliary sorber 120 via dotted line 70 and combine this effluent with the product in line 60. The combination of the effluent having a sulfide concentration of say 10 ppmv with the product stream having 0 ppmv of sulfide would result in the required product specification of 5 ppmv. Of course, depending upon the actual amount of sulfur compounds contained within the adsorption effluent and the actual required product specification, one skilled in the art can readily vary the proportions of the effluent and product streams in order to arrive at a particular final average which should equal the product specification for the amount of sulfur compounds allowed. The advantage of by-passing some adsorption effluent past the auxiliary sorber is to reduce the sulfur loading on this bed and consequently increase its operating life.
Referring now to FIG. 2C', a further alternative embodiment for the third phase of the cycle is shown. Here, the feedstock enters through line 10 and is split into lines 12' and 14' to ente primary adsorbers 100 and 110, respectively. In this embodiment, a portion of the feedstock is introduced to adsorber 110 at the inlet thereof instead of introducing regeneration medium at the outlet end as in the embodiment shown in FIG. 2C. In this manner, although the adsorbent contained within adsorber 110 has not yet been cooled to be strictly speaking on the adsorption mode, it nevertheless is employed on a somewhat semi-adsorption mode in which cooling is provided by the entering feedstock which progressively allows for additional adsorption capability as cooling continues by the introduction of the relatively cooler feedstock into adsorber 110. Moreover, since only a portion of the feedstock is entering adsorbers 100 and 110, respectively, the amount of sulfide load per bed is considerably lower. This is one of the advantages of this alternative embodiment, i.e., the adsorption effluents leaving adsorbers 100 and 110 at lines 16' and 18', respectively, have considerably lesser amount of sulfur compound concentration than the adsorption effluent of the embodiment shown in FIG. 2C. In this manner, less loading is also required in auxiliary sorber 120.
The adsorption effluents leaving adsorbers 100 and 110 can then individually and separately be treated by one or more auxiliary sorbers or, as shown in FIG. 2C', can be combined and passed via line 20' to auxiliary sorber 120 and be recovered as a product stream containing a purified fluid stream in line 22'.
The fluid stream that is suitably treated in the process of the present invention is not critical with respect to its origin, its constituent molecular species or its relative proportions of those molecular species within the feedstock. Thus, the fluid stream may be a hydrocarbon stream resulting from the destructive hydrogenation of coal or it may be obtained from deposits of natural gas or petroleum. Sulfur-containing condensates from natural gas, i.e., the LPG compositions rich in propane and butanes, are also well suited to the present process as are natural gasolines and relatively light petroleum fractions boiling between about -44° to about 180° F. which are mostly comprised of C 3 to C 6 hydrocarbons. Moreover, liquid or liquifiable olefin or olefin-containing streams, such as those used in alkylation processes, containing propylene butylene, amylene, and the like, are also suitably employed. The preferred feedstock for treatment in accordance with the present invention is, however, a sour natural gas.
Generally, the sulfur compound impurities present in these feed streams comprises at least one but ordinarily a mixture of two or more of hydrogen sulfide, the mercaptans such as ethyl mercaptan, n-propyl mercaptan, isopropyl mercaptan, n-butyl mercaptan, isobutyl mercaptan, t-butyl mercaptan, and the isomeric forms of amyl and hexyl mercaptan, the heterocyclic sulfur compounds such as thiophene and 1,2 dithiol, and aromatic mercaptans exemplified by phenyl mercaptan, organic sulfides generally and carbonyl sulfide, and the like.
The physical adsorbent employed in the primary adsorbers of the present invention are adsorbents which are regenerable and which are applicable for selectively adsorbing the above noted sulfur compound impurities from a fluid stream by means of a physical adsorption process in contrast to a chemical reaction. Suitable physical adsorbents include, but are not limited to, crystalline zeolite molecular sieves, carbon-based adsorbents, silica gel, activated alumina, and the like.
The physical adsorbents which are particularly suitable in the process of this invention are the crystalline zeolite molecular sieves.
The term "zeolite", in general, refers to a group of naturally occurring and synthetic hydrated metal-alumino silicates, many of which are crystal in structure. There are, however, significant differences between the various synthetic and natural materials in chemical composition, crystal structure and physical properties such as x-ray powder diffraction patterns.
The structure of the crystalline zeolite molecular sieves may be described as an open three-dimensional frame work of SiO 4 and AlO 4 tetrahedra. These zeolites are activated by driving off substantially all of the water of hydration. The space remaining in the crystals after activation is available for adsorption of absorbate molecules. This space is then available for adsorption of molecules having a size, shape and energy which permits entry of the adsorbate molecules to the pores of the molecular sieves.
Molecular sieves having pores with an apparent minimum dimension of at least 3.8 angstrom units have been found satisfactory when the sulfur compound impurity which is to be adsorbed is hydrogen sulfide. For normal mercaptans having less than seven carbon atoms, the apparent pore size should be at least about 4.6 angstrom units. The sulfur compounds of larger molecular dimensions such as isopropyl mercaptan, isobutyl mercaptan, t-butyl mercaptan, the isomeric form of amyl and hexyl mercaptan, and the heterocyclic sulfur compounds exemplified by thiophene as well as the aromatic mercaptans exemplified by phenyl mercaptan require the use of a zeolitic molecular sieve having apparent pore openings of at least about 6 angstrom units.
The term "apparent pore size" as used herein may be defined as the maximum critical dimension of the molecular species which is adsorbed by the zeolitic molecular sieve in question under normal conditions. The apparent pore size will always be larger than the effective pore diameter, which may be defined as the free diameter of the appropriate silicate ring in the zeolite structure.
Among the naturally occurring zeolitic molecular sieves suitable for use in the present invention include mordenite and chabazite, both having an apparent pore size of about 4 angstrom units, erionite having an apparent pore size of about 5 angstrom units, and faujasite having a pore size of about 10 angstroms.
The preferred synthetic crystalline zeolitic molecular sieves includes zeolites A, X, Y and L, each of which have a pore size of about 3 to 10 angstroms and which are all well known to those skilled in the art. Reference is made to U.S. Pat. No. 3,620,969 which discusses these zeolites. Most preferred are zeolites 4A, 5A, and zeolite 13X, alone or in combination with each other.
The pore size of the zeolitic molecular sieves may be varied by employing different metal cations. For example, sodium zeolite A (U.S. Pat. No. 2,882,243) has an apparent pore size of about 4 angstrom units, whereas calcium zeolite A has an apparent pore size of about 5 angstrom units.
The zeolites occur as agglomerates of fine crystals or are synthesized as fine powders and are preferably tableted or pelletized for large scale adsorption uses. Pelletizing methods are known which are very satisfactory because the sorptive character of the zeolite, both with regard to selectivity and capacity, remains essentially unchanged. Many suitable inert binder materials or compositions are well known in the art including clays, refractory metal oxides and alkali metal silicates, if it is desired to utilize the adsorbents in agglomerated form. In general, the individual molecular sieve crystals are quite small (of the order of 10 microns) and hence in fixed bed operation, at least, it is advantageous to agglomerate the crystals into beads, pellets, extrudate forms, etc., either with or without added binder material.
Generally, the conditions for adsorption utilizing the molecular sieves include a temperature in the range from about 32° to about 200° F., and more preferably a temperature in the range from about 50° to about 140° F. at a pressure of 0.1 to 4000 psig and more preferably 10 to 2000 psig. For desorption, it is desirable to maintain the adsorbent undergoing regeneration at a temperature of from about 300° to about 700° F., more preferably about 450° to about 600° F., at the same pressure range noted for adsorption.
Activated alumina is a porous form of aluminum oxide of high surface area. It is capable of selective physical adsorption in many applications and is chemically inert to most gases and vapors, non toxic and will not soften, swell or disintegrate when immersed in water. High resistance to shock and abrasion are two of its important physical characteristics. The adsorbed material may be driven from the activated alumina by suitable choice of reactivating temperature, thus returning it to its original adsorptive form.
Activated aluminum may be reactivated to its original adsorptive efficiency by employing a heating medium at any temperature between 250° F. and 600° F. For thorough regeneration, the temperature of the regenerating gas on the exit side of the bed should reach at least 350° F.
Silica gel is a granular, amorphous form of silica, made from sodium silicate and sulfuric acid. Silica gel has an almost infinite number of sub-microscopic pores or capillaries by which it can act as a selective adsorbent depending upon the polarity and molecular size of the constituents within the fluid feed stream that is being treated.
The use of these physical adsorbents as well as adsorbents such as activate carbon, and the like, are well known to those skilled in the art and their selection, operating conditions and regenerating conditions are easily ascertainable to those skilled in the art.
The sorbents that are suitable for use in the auxiliary sorbers of the present invention are preferably chemisorbents which chemically react with the sulfur compounds rather than merely physically adsorbing them as do the physical adsorbents discussed above. Generally, these materials are not readily regenerable and must be discarded and replenished when they are laden with the sulfur compound materials. Obviously, these chemisorbents must be able to also selectively remove sulfur compound impurities from the fluid streams such as those described above.
Suitable chemisorbents that are applicable in the present invention include but are certainly no limited to, zinc oxide; iron sponge; causticized alumina; impregnated carbon, such as carbon impregnated with iodine or metallic cations; as well as zeolite A, zeolite X or zeolite Y, all of which have been ion exchanged with either zinc, copper or iron cations; chelating compounds such as metal complexes and the like; and suitable liquid treating solutions capable of selectively removing sulfur compound impurities such as Merox (distributed by UOP, Des Plaines, Ill.); and the like.
Preferably, zinc oxide is utilized as the sorbent in the auxiliary sorber.
The determination of the size of the primary and auxiliary beds that are employed for a given fluid feedstock at a particular set of conditions involves a balancing of capital costs, operating costs, regeneration requirements and recovery, gains in sorbent inventory reduction, and the like, in order to arrive at an overall cost for a particular system and a further determination as to whether the optimized combination has been obtained.
Generally, as noted above, even a slight decrease in the loading requirements of the primary adsorber will result in a larg reduction in adsorbent inventory. This is vividly demonstrated below in Table I in which the % reduction in the amount of molecular sieve required to remove hydrogen sulfide from a feed stream of natural gas at a variety of different starting hydrogen sulfide concentrations and at different inlet pressures is set forth when going from the case in which the molecular sieve adsorbent is expected to reduce the sulfide concentration to 1 ppmv, as may be required by the prior art, to the embodiment of the present invention in which the sulfide is allowed to break through the primary adsorber to the extent of 5 ppmv, which will ultimately be removed by an auxiliary sorber containing 300 cubic feet of zinc oxide.
TABLE I______________________________________MOLECULAR SIEVE BED SIZE COMPARISONS % ReductionH.sub.2 S in. Feed Pressure in Amount of MSFeed (ppmv) (psig) Needed at 5 ppmv______________________________________(1) 20 1000 27(2) 50 1000 14(3) 100 1000 9(4) 1000 1000 2(5) 10 500 73(6) 20 500 40(7) 50 500 11(8) 100 500 9(9) 1000 500 4______________________________________
As is clearly seen, depending upon the inlet conditions of the feed stream, it is not uncommon to be able to realize reductions in the molecular sieve inventory of as much as 50 to 75 percent.
Generally, for a given breakthrough of sulfide compounds from the primary adsorbent bed, as the feed pressure increases, and/or as the temperature of the feed decreases, and/or as the amount of the sulfur compounds within the feed stream decreases, the less molecular sieve that is required. However, it is not always feasible or even desirable to alter any of these feed inlet conditions.
Thus, the quantity of sulfur compounds contained within the feed stream clearly cannot be modified prior to its introduction into the system for it is the purpose of this very process to reduce that sulfur concentration. So too, it would also be economically unsound to increase the pressure of such a feed stream prior to its entering the adsorption bed merely to reduce the quantity of adsorbent that is required if the energy and capital costs to compress such gas would exceed the cost of adsorbent saved.
As to the temperature of the feed stream, it is generally desirable to cool this stream if its temperature is greater than about 130° F., preferably greater than about 150° F., and more preferably when the temperature is greater than about 175° F. The economic savings realized by utilizing less adsorbent offsets the energy costs associated with such cooling. Generally, the feed stream is cooled to a temperature in the range of from about 90° to 110° F., preferably about 100° F.
The one variable which can, however, clearly be controlled by the process of the present invention and which has a material effect upon the overall costs of the system is the amount of sulfur compound breakthrough allowed to occur in the primary adsorber.
In particular, once a particular breakthrough is chosen, the amount of sorbent required in the auxiliary bed to provide a given operating life before replacement is necessary is determined based on design considerations well known to those skilled in the art. Similarly, based upon design consideations well known to those skilled in the art, once the inlet and outlet conditions for the primary adsorber are also known, it is a simple matter to determine the amount of adsorbent needed to provide the chosen sulfide concentration breakthrough in the adsorption effluent. This initial determination, however, may not be the most optimized design although the amount of physical adsorbent may have nevertheless been reduced. The optimum fine tuning of this design will depend upon the overall costs involved for a particular system including the initial capital costs and continuing operating costs for a given period of time. This is clearly demonstrated in Table II below.
TABLE II__________________________________________________________________________OVERALL COSTS OF DIFFERENTSULFIDE REMOVAL SYSTEMS__________________________________________________________________________ FEED: Natural Gas 900 MMSCFD H.sub.2 S = 25 ppmv CO.sub.2 = 1.0% Optimized DEA.sup.1 MS MS + ZnO MS + ZnO ZnO 50% SOLN__________________________________________________________________________INITIAL CHARGEMS, M$ (BEDS) 918(12) 680(12) 360(8) -- --ZnO, M$ (BEDS) -- 780(6) 520(4) 7611 --REGEN, GAS REQ'DMMSCFD 126 45 25 -- --UTILITY COSTSMS M$/YR 459 340 180 0 0ZnO M$/YR 0 780 520 7611 0REGEN, BTU, M$/YR 1080 798 400 0 0ZnO FEED PREHEAT, M$/YR 0 0 0 3234 0REGEN. DEA, M$/YR 500 250 0 0 2618TOTAL M$/YR 2039 2168 1100 10845 2618SAVINGS.sup.2, M$/YR 939 1068 -- 9745 1518CAPITAL COSTSMS, MM $ 11.4 9.6 5.6 -- --ZnO, MM $ -- 3.3 3.5 5.0 --REGEN. DEA, MM $ 2.0 1.4 -- -- --DEA, MM $ -- -- -- -- 8.2TOTAL MM $ 13.4 14.3 9.1 5.0 8.2__________________________________________________________________________ .sup.1 DEA = diethanolamine Assumptions made: 1. H.sub.2 S loading in ZnO is equal to 12 lbs H.sub.2 S/ft.sup.3 ZnO. 2. 1ft.sup.3 ZnO = $175.00; ZnO life = 6 months 3. MS life = 2 yrs 4. $3/MM BTU for MS regen. treatment. 5. MS cost = $1.75/lb. .sup.2 Relative savings when using optimized MS + ZnO system as compared to system being considered.
As is clearly seen, although the "MS+ZnO" example is quite advantageous over the MS, ZnO or DEA systems alone, an optimieed combination of MS and ZnO could still be designed which provides even more dramatic results.
The most easily controlled optimization variable for obtaining the most cost effectiveness in the integrated system of the present invention is the amount of sulfur compound breakthrough from the primary adsorber.
Applicants have determined that for an inlet feed stream pressure of from about 0.1 to about 4000 psi, a temperature in the range of from about 32° to about 700° F., and a sulfur compound concentration in the feed stream of about 1 to about 5000 ppmv, the capital cost of the integrated system will economically be optimized if the sulfur compound breakthrough is in the range of from about 1 to 10 ppmv, preferably from about 1 to about 6 ppmv, and most preferably from about 2 to 5 ppmv.
This is demonstrated in Table III below in which a number of runs were made using the same feed stream composition and inlet conditions as noted therein for various hydrogen sulfide breakthroughs of from 1.0 to 18.0 ppmv.
TABLE III__________________________________________________________________________NATURAL GAS DESULFURIZATION__________________________________________________________________________ FEED: Natural Gas Flow Rate: 100 mmscfd Pressure: 1000 psig Temperature: 90° F. H20: Sat'd at Flowing Condition H2S: 20 ppmv Product Spec: 0.1 ppmv H2SM.S./ZnO System__________________________________________________________________________B.T. MS BED (ppmv H2S) 1.0 2.0 5.0 10.0 15.0 18.0CYCLE TIME (hrs) 8 8 8 8 8 8ADSORBENT INVENTORYMS, lbs (bed) 119,400(2) 111,600(2) 97,200(2) 87,600(2) 85,200(2) 84,600(2)ZnO, lbs (bed) 1,610(2) 3,230(2) 8,060(2) 16,130(2) 24,190(2) 29,020(2)REGEN GAS (MMSCFD)Required** 10.95 9.63 8.07 6.95 6.52 6.31Flared or Treated 5.48 4.82 4.03 3.48 3.26 3.15INITIAL CHARGE (M$) *MS 179.10 167.40 145.80 131.40 127.80 126.90ZnO 10.26 20.52 51.30 102.60 153.91 184.70Total 189.36 187.92 197.10 234.00 281.71 311.60UTILITY COST (M$/yr.)MS 89.55 83.70 72.90 65.70 63.90 63.45ZnO 10.26 20.52 51.30 102.60 153.91 184.70Energy Cost 105.31 93.78 79.10 68.73 64.93 3.16Total 205.12 198.00 203.30 237.03 282.74 311.31CAPITAL COST (MM$)MS 1.814 1.718 1.554 1.433 1.403 1.392ZnO 0.152 0.225 0.400 0.610 0.761 0.810Total 1.966 1.943 1.954 2.043 2.164 2.202__________________________________________________________________________ Basis: *MS: $1.50/lb, 2 yr. life ZnO: $175.00/cu ft., 6 month life **Assume 1/2 of the regen gas is flared or treated
It is noted that while the specific results set forth in Table III and FIGS. 3, 4, 5 and 6 are all based on a given set of feed inlet conditions of temperature, pressure, sulfide concentration and for a given product specification, this data is nevertheless indicative of the general trend of the relationships shown therein. Thus while a change in inlet conditions or product specification may somewhat affect the absolute amount of adsorbent reduction, Applicants have determined that a sulfide breakthrough in the range of from about 1 to about 10 ppmv still provides the most optimum results for an inlet feedstream pressure of from about 0.1 to about 4000 psi, a temperature in the range of up to about 700° F., and a sulfur compound concentration in the feedstream of about 1 to about 5000 ppmv, as noted earlier.
FIG. 3 graphically sets forth the relationship of capital cost of the integrated system as a function of the amount of breakthrough from the primary adsorber bed. The above noted optimum breakthrough concentrations are vividly depicted in this graph.
While FIGS. 4, 5 and 6, based on the results of Table III above, seem to infer that the higher the breakthrough, the lower the overall costs which include energy requirements, the amount of regeneration gas that is flared, and the amount of regeneration gas that is required, the overall economic considerations are such that the capital costs of the system by far outweigh these operating costs. Consequently, the optimum breakthrough concentration for obtaining the lowest capital cost is generally the ideal concentration for obtaining the optimum economic benefit for the overall system as a whole.
The optimized molecular sieve/zinc oxide system provides a substantial savings in utility costs and in initial capital costs as well as a dramatic decrease in the amount of regeneration gas that is typically lost in prior art techniques. While the individual zinc oxide system requires a lower initial investment cost, the much higher yearly operating costs more than make up for this initial difference in installation cost.
We now turn to FIGS. 7 and 8, which depict alternative embodiments of the basic integrated process discussed above. As noted earlier, there may be occasions when downstream processing of the treated fluid stream may require strict tolerances as to the amount of water present in that stream. Such water may, for example, be undesirable due to possible corrosion problems or freeze-ups that it may cause in such downstream processing steps.
If there is any water present in the treated product stream leaving the integrated process of the present invention, it most likely will have originated from either or both of two sources: the fluid feed stream itself and/or the auxiliary sorber. Thus, depending upon the source and nature of the fluid feed stream entering the integrated process of the present invention as well as its temperature and pressure, the amount of water that is present may vary from about 0 ppmv to about saturation. Generally, the physical absorbent utilized in the primary adsorber, in addition to adsorbing sllfur compound impurities, typically is capable of also adsorbing water as well. Consequently, upon regeneration of such a spent adsorbent, not only sulfur-compound impurities are present in the regeneration effluent, but water is present as well. Without providing some means to remove this water, it simply stays in the effluent, even after passing through the auxiliary sorber, and ultimately winds up in the product stream.
Indeed, if zinc oxide, for example, is utilized as the chemisorbent in the auxiliary sorber it, in and of itself, is also a source of water generation which is caused by the chemical reaction of the zinc oxide with the sulfide compounds to produce water as a by-product. This water also finds its way into the product effluent stream. Hence, even if the entering fluid feed stream is relatively dry, with a very low water concentration, the final product may nevertheless contain a higher than desired moisture content due to the use of zinc oxide as the chemisorbent. However, since zinc oxide is the most preferred sorbent material for the selective removal of the sulfur impurities, this water by-product must be dealt with if the amount of water present in the product stream is of importance.
In the embodiment shown in FIGS. 7 and 8, Applicants have provided a process which modifies the process of FIGS. 2A-C in a manner such that the amount of water present in the product stream is controlled to the extent desirable, even so as to provide a substantially dry product stream.
In essence, the overall process of FIGS. 2A-C is modified by incorporating an additional intermediary phase into the cycle, which phase takes into account and provides for the water that may be present in the regeneration effluent and the water that may be generated by a chemisorbent such as zinc oxide.
More particularly, the first phase of this alternative embodiment, in which the amount of water contained within the product stream is to be controlled, is essentially identical to the first phase of the embodiment shown in FIG. 2, and is accurately depicted in FIG. 2A. The fluid feed stream containing an appreciable amount of water, enters line 10 and is passed through primary adsorber 100 which contains a physical adsorbent selective for adsorbing both sulfur compounds and water from within the fluid stream. Zeolite molecular sieve is the preferred physical adsorbent for such selectivity. Adsorption effluent leaving in line 20 is substantially free of both sulfur compounds and water.
As in the previous embodiment discussed earlier, a portion of adsorption effluent, if desired, is utilized to regenerate the spent adsorbent contained within primary adsorber 110 which is now laden with sulfur compound impurities as well as water. Preferably, as shown in FIG. 2A, the adsorption effluent is first heated in furnace 140 prior to entering adsorber 110. The regeneration effluent, in this first phase, contains a high concentration of sulfur compound impurities and is either flared, used as fuel, or the like.
This first phase, as in the previous embodiment, is continued until the hydrogen sulfide peak of curve A in FIG. 1 has passed, and the regeneration effluent contains a reduced, substantially constant sulfur compound concentration. However, as can be noted from FIG. 1, although the hydrogen sulfide peak (curve A) has passed, the water peak shown in curve D has not yet even been reached. Accordingly, even though the amount of sulfur compounds present in the regeneration effluent is substantially reduced, the amount of water will actually be increasing for a period of time. Consequently, instead of immediately proceeding with the process phase depicted in FIG. 2B, in which the regeneration effluent is recovered by passing it directly to an auxiliary sorber, in this alternative embodiment, an additional phase is first carried out so as to control the amount of water that is present in the product stream.
This additional, supplementary phase, is carried out between the first and second phases of the embodiment discussed above, which are depicted schematically in FIGS. 2A and 2B, respectively. This supplementary phase is schematically shown in FIG. 7. Here, instead of passing the regeneration effluent directly to the auxiliary sorber as shown in FIG. 2B, regeneration effluent is recovered by recombining the effluent with the incoming feed stream so that it is able to once again be subjected to the primary adsorber for water removal. To prevent a water buildup in this recycle, a conventional water knockout pot is provided for the removal of condensed water vapor after the regeneration effluent has been cooled prior to its being recombined with the feed stream.
More specifically, the hot regeneration effluent leaves primary adsorber 110 via line 40 at a temperature of from about 42° F. to about 700° F. and is indirectly heat exchanged in heat exchanger 150 with the cooler adsorption effluent contained in line 33 which is at a temperature of from about 32° F. to about 200° F. The regeneration effluent, now having a reduced temperature of from about 35° F. to about 400° F., is then passed in line 82 to knockout pot 160 in which from about 50% to about 90%, preferably about 75% to 90% of the moisture contained in the regeneration effluent is removed. Knockout pot 160 is not critical to the present invention and any other water removal means well known to those skilled in the art would equally be applicable. From knockout pot 160, the regeneration effluent is then combined with fluid feed stream in line 10 to form a combined feed stream entering primary adsorber 100 via line 80.
The adsorption effluent, after having been heated to a temperature of from about 35° F. to about 250° F., enters line 86 and may then be introduced into auxiliary sorber 120. It is understood that where the amount of water present in the product will be of concern and, therefore, this alternative embodiment of the present invention will be practiced, the primary adsorbers will be sized accordingly so as to compensate for the added sulfur compounds and water that will be introduced as a result of the recycled regeneration effluent. HHence, until there is sulfur compound breakthrough from the primary adsorber (curve B of FIG. 1), there will be substantially no sulfur compounds or water present in the adsorption effluent. While it is therefore not necessary to pass the adsorption effluent to the auxiliary sorber until such sulfur breakthrough, it may nevertheless be done, if so desired. Otherwise, the adsorption effluent in line 86 may simply by-pass auxiliary sorber 120 as shown by dotted line 70. Generally, the primary adsorbers are designed such that there is no water breakthrough from the primary adsorbers.
In this alternative embodiment, in addition to containing a sorbent that is capable of removing sulfur compound impurities, the auxiliary sorber may also contain an additional physical adsorbent to adsorb any water that may possibly still be present in the effluent, as may be desired, in order to obtain a product stream having a particular moisture content or to have a product stream with substantially no water present at all. Such physical adsorbent would be segregated from the chemisorbent, preferably as a separate layer, and positioned close to the discharge end of the sorber such that the last layer that the effluent stream is subjected to as it is leaving the sorber is the physical adsorbent which will remove moisture therefrom.
In the case where zinc oxide is utilized as the chemisorbent for the auxiliary sorber, and where it is important to control the amount of water present in the product stream, it may be necessary to provide such a physical adsorbent so as to adsorb the moisture that is generated by the zinc oxide/sulfide reaction.
Based upon conventional stochiometric principles, one skilled in the art can readily determine how much physical adsorbent would be required to adsorb the amount of moisture produced in the zinc oxide reaction and/or entering the auxiliary sorber to arrive at a particular moisture concentration in the discharged product stream.
In the embodiment shown in FIG. 7, it is understood that once the physical adsorbent becomes laden with either water and/or sulfur, the auxiliary sorber will have to come off-stream and the adsorbent either be replaced or regenerated. In FIG. 8, however, a further embodiment is set forth in which such regeneration is carried out on-stream.
Referring to FIG. 8, a second auxiliary sorber 120' is shown which is on a regeneration mode for the physical adsorbent contained therein. In this embodiment, the adsorption effluent, instead of being directly passed to adsorber 110 for the regeneration of the adsorbent contained therein, is first passed through sorber 120' and only then on to adsorber 110. In this manner, the physical adsorbent contained within auxiliary sorber 120' is regenerated simultaneously with the adsorbent in adsorber 110. Except for line 88, which carries the auxiliary sorber eflluent to adsorber 110, and the simultaneous regeneration of auxiliary sorber 120', the process scheme of FIG. 8 is essentially identical to the scheme of FIG. 7.
The supplemental phase depicted in FIGS. 7 and 8 is continued until the desired value of water concentration in the regeneration effluent is reached as noted by curve D in FIG. 1. Once that value is obtained, the process of this embodiment may then continue as is or, alternatively, continue with the second and third phases of the embodiment discussed earlier which is depicted in FIGS. 2B and 2C.
However, even when continuing this alternative embodiment with the phases of 2B and 2C, the auxiliary sorber should desirably still contain physical adsorbent to aid in the removal of water from the product stream when zinc oxide is utilized as the chemisorbent therein. So too, the simultaneous regeneration of the auxiliary sorber and the primary adsorber with adsorption effluent may still be carried out even during the phases depicted in FIGS. 2B and 2C. | The present invention relates to a new and integrated process involving the utilization of a primary adsorption bed containing a regenerable, physical absorbent and an auxiliary sorption bed containing a chemisorbent and an optional physical absorbent for the removal of sulfur compounds and water from a fluid stream, which process provides for higher yields, higher purity and lower costs. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to a novel method for inhibiting microvascular thrombosis and, more particularly, to a method for reducing the thrombogenicity of microvascular anastomoses during microvascular reconstruction by the topical administration of a blood coagulation inhibitor known as lipoprotein-associated coagulation inhibitor (LACI) and alternatively as tissue factor pathway inhibitor (TFPI).
Thrombosis of microvascular anastomoses, particularly in cases of extremity trauma in free flap reconstructions, is a significant problem for the reconstructive surgeon. A recent survey by Salemark, Microsurgery 12, 308-311 (1991), revealed that many centers routinely make use of systemic anticoagulation for replants and free flap transfers. However, the risk for generalized hemorrhage [Leung, Hand 12, 25-32 (1980); Hirsh, Semin. Thromb. Hemostas. 12, 21-32 (1980)], with compounding risks from blood transfusion products, leaves open the question of benefit from massive systemic circulatory alteration merely to preserve flow in a small vessel supplying blood to non-vital tissue.
The concept of site-specific action by an antithrombotic agent, administered through simple topical application was proposed by Cooley and Gould, Microsurgery 12, 281-287 (1991). Since those vessels which are prone to thrombosis are exposed during the reconstructive effort, with ready access to the lumenal surface during the anastomotic repair, an agent could be applied through the course of normal vessel irrigation, potentially achieving a highly localized effect through surface binding to the thrombogenic site(s). In fact, Cooley et al. have described one possible agent, a peptide based on the platelet-binding and fibrin-polymerizing region of fibrinogen, and have shown its ability to reduce the occurrence of thrombotic occlusion in a rat model [6th Ann. Meeting, Amer. Soc. Reconstructive Microsurgery, Toronto, Canada. Sep. 21-23, 1990].
Thrombosis caused by vascular injury is at least partially if not predominantly initiated through the tissue-factor-mediated pathway of coagulation.
Plasma contains a multivalent Kunitz-type inhibitor of coagulation, referred to herein as tissue factor pathway inhibitor (TFPI). This name has been accepted by the International Society on Thrombosis and Hemostasis, Jun. 30, 1991, Amsterdam. TFPI was first purified from a human hepatoma cell, Hep G2, as described by Broze and Miletich, Proc. Natl. Acad. Sci. USA 84, 1886-1890 (1987), and subsequently from human plasma as reported by Novotny et al., J. Biol. Chem. 264, 18832-18837 (1989); Chang liver and SK hepatoma cells as disclosed by Wun et al., J. Biol. Chem. 265, 16096-16101 (1990). TFPI cDNA have been isolated from placental and endothelial cDNA libraries as described by Wun et al., J. Biol. Chem. 263, 6001-6004 (1988); Girard et al., Thromb. Res. 55, 37-50 (1989). The primary amino acid sequence of TFPI, deduced from the cDNA sequence, shows that TFPI contains a highly negatively charged amino-terminus, three tandem Kunitz-type inhibitory domains, and a highly positively charged carboxyl terminus. The first Kunitz-domain of TFPI is needed for the inhibition of the factor VII a /tissue factor complex and the second Kunitz-domain of TFPI is responsible for the inhibition of factor X a according to Girard et al., Nature 328, 518-520 (1989), while the function of the third Kunitz-domain remains unknown. See also copending application Ser. No. 07/301,779, filed Jan. 26, 1989, now U.S. Pat. No. 5,106,833. TFPI is believed to function in vivo to limit the initiation of coagulation by forming an inert, quaternary factor X a : TFPI: factor VII a : tissue factor complex. Further background information on TFPI can be had by reference to the recent reviews by Rapaport, Blood 73, 359-365 (1989); Broze et al., Biochemistry 29, 7539-7546 (1990).
Recombinant TFPI has been expressed as a glycosylated protein using mammalian cell hosts including mouse C127 cells as disclosed by Day et al., Blood 76, 1538-1545 (1990), baby hamster kidney cells as reported by Pedersen et al., J. Biol. Chem. 265, 16786-16793 (1990), Chinese hamster ovary cells and human SK hepatoma cells. The C127 TFPI has been used in animal studies and shown to be effective in the inhibition of tissue factor-induced intravascular coagulation in rabbits according to Day et al., supra, and in the prevention of arterial reocclusion after thrombolysis in dogs as described by Haskel et al., Circulation 84, 821-827 (1991).
Recombinant TFPI also has been expressed as a non-glycosylated protein using E. coli host cells and obtaining a highly active TFPI by in vitro folding of the protein as described in co-pending application of Judy A. Diaz-Collier, Mark E. Gustafson and Tze-Chein Wun, on "Method of Producing Tissue Factor Pathway Inhibitor", Ser. No. 07/844,297, filed Mar. 22, 1992, now U.S. Pat. No. 5,112,091, the disclosure of which is incorporated by reference herein.
The cloning of the TFPI cDNA which encodes the 276 amino acid residue protein of TFPI is further described in Wun et al., U.S. Pat. No. 4,966,852, the disclosure of which is incorporated by reference herein.
BRIEF DESCRIPTION OF THE INVENTION
In accordance with the present invention a novel method is provided for inhibiting microvascular thrombosis. The method comprises topically administering to a warm blooded mammal at the site of microvascular anastomoses contemporaneously with microvascular reconstruction of a small, but effective amount of TFPI sufficient to reduce the thrombogenicity of microvascular anastomoses.
The invention is illustrated herein by topical application of the TFPI to a rabbit ear artery model of crush/avulsion injury subjected to microvascular repair. In this illustrative topical application of TFPI, traumatized arteries treated through lumenal irrigation with normal saline vehicle (controls) achieved patency rates of 8% and 0% at 1 and 7 days postoperatively (p.o.), respectively. Heparin irrigation (10 units/ml) resulted in patencies of 40% at both evaluation times. In contrast, TFPI at a dose of 20 μg/ml (0.2 ml total volume; 10-minute exposure) yielded a 91% patency rate at 1 day, and 73% at 7 days p.o. (p<0.0005 vs. controls). Systemic anticoagulation effect was checked with peripheral blood prothrombin time (PT) and activated partial thromboplastin time (APTT). These values were not altered after topical treatment with TFPI. Scanning electron microscopy revealed dramatically inhibited thrombogenesis upon the injured surfaces of TFPI-treated vessels. These results support the effectiveness of TFPI used as a topically-applied antithrombotic agent for the prevention of thrombosis in clinical microvascular surgery.
It will be appreciated that the method of the invention is useful for other warm blooded mammals, e.g. humans, in a analogous manner. It is expressly adapted for microvascular reconstruction such as by free flap transfer or replantation surgery.
As defined herein, TFPI can be either glycosylated or non-glycosylated.
DETAILED DESCRIPTION OF THE INVENTION
While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as forming the present invention, it is believed that the invention will be better understood from the following detailed description of preferred embodiments taken in conjunction with the accompanying drawings in which:
FIG. 1 is a bar graph that shows the patency rates achieved at 1 and 7 days postoperatively, for each of three treatment groups, in which topical administration of TFPI during microvascular repair of a vascular trauma in a rabbit ear model is compared with similar administration of heparin or the control vehicle (normal saline) without either TFPI or heparin.
FIG. 2, in 3 parts, namely FIGS. 2A, 2B and 2C, shows the scanning electron micrographs at several magnifications of the lumenal surfaces of vessels one hour after reflow, following microvascular repair and topical administration of TFPI as in FIG. 1. FIG. 2A=30X; FIG. 2B=100X; FIG. 2C=2000X.
FIG. 3, in 3 parts, namely FIGS. 3A, 3B and 3C, shows scanning electron micrographs at several magnifications of the lumenal surfaces one hour after reflow, following microvascular repair and topical administration of heparin as in FIG. 1. FIG. 3A=30X; FIG. 3B=100X; FIG. 3C=2000X.
FIG. 4, in 3 parts, namely FIGS. 4A, 4B and 4C, shows scanning electron micrographs at several magnifications of the lumenal surfaces one hour after reflow, following microvascular repair and topical administration of the control vehicle without either TFPI or heparin as in FIG. 1. FIG. 4A=30X; FIG. 4B=100X; FIG. 4C=2000X.
In order to illustrate the invention in greater detail, the following illustrative microsurgical repair of vascular trauma accompanied with administration of TFPI was carried out. It will be appreciated, however, that the invention is not limited to this exemplary work or to the specific details set forth in these examples.
EXAMPLES
Materials and Methods
The NIH guidelines for the care and use of laboratory animals were followed throughout. New Zealand White rabbits (3-5 lbs) were anesthetized with intramuscular injection of ketamine (100 mg) and xylaaine (20 mg). Under sterile conditions, the central ear artery was exposed over a length of 20 mm. A modification of the crush-avulsion injury of Cooley and Hansen, Microsurgery 6, 46 48 (1985), was created as follows. Two Webster needleholders were clamped firmly upon the artery 2 mm from each other, then moved apart in proximal-distal directions, traumatically severing the artery. Temporary microvascular clamps were applied beyond the Webster crush sites, and the lumen was flushed with normal saline. The torn ends of the artery were minimally trimmed, preserving essentially the entire length of traumatized artery. An end-to-end anastomosis was next performed using 8-10 stitches of 10-0 nylon suture. Before tying the last stitch, 0.2 ml of a test solution was irrigated across the anastomosis and injured lumen, filling the vessel with the fluid. It was left in place for 10 minutes, then washed out with normal saline. One of three solutions was used per vessel on a blinded, randomized basis: TFPI at a concentration of 20 μg/ml in normal saline, heparin (10 units/ml) in normal saline, or normal saline (the control vehicle).
The TFPI used in these Examples was obtained through recombinant DNA clones expressed in E. coli It is a 277 amino acid protein consisting of the 276 residue sequence described by Wun et al., J. Biol. Chem. 263, 6001-6004 (1988), and in U.S. Pat. No. 4,966,852, with an additional Alanine residue inserted at the N-terminus as further described in the aforesaid copending application of Diaz-Collier, Gustafson and Wun, Ser. No. 07/844,297, filed Mar. 22, 1992, now U.S. Pat. No. 5,212,091. It is >95% homogeneous.
Upon completion of the repair and irrigation of the lumen as described above, the temporary clamps were released. In 34 arteries (from 17 rabbits), the patency was followed for 1 hour, then the wound was closed Re-anesthetization was induced at 1 and 7 days post-operatively for re-evaluation of patency.
In a separate series, 9 arteries (from 5 rabbits), were divided into 3 groups of 3 vessels each; TFPI, heparin or vehicle was administered to each as described above. The injured and repaired vessels were harvested after 1 hour of flow, fixed in buffered glutaraldehyde, and prepared for examination of the lumenal surfaces with a scanning electron microscope. Blood was drawn from a femoral vein branch before arterial injury and again one hour after reflow (before vessel harvest). Prothrombin (PT) and activated partial thromboplastin (APTT) times were determined on plasma samples using a standard, commercially available fibrometer.
Results
Patency rates for all groups are shown in FIG. 1. All vessels that were patent at 1 day had shown clear patency at 1 hour of reflow. Vessels found thrombosed at 1 day were still thrombosed at 7 days, for all groups. The patency rates for the control (vehicle-treated) arteries were 8% (1/13) at 1-day and 0% (0/13 at 7 days postoperatively. Heparin-treated vessels achieved 40% (4/10) patency at both 1 and 7 days, with a significant improvement noted at 7 days (p <0.025; Fisher exact test). TFPI treatment resulted in 91% (10/11) and 73% (8/11) patency rates at 1 and 7 days, significantly better than controls for both time periods (p <0.0005). The TFPI-treated vessels had a significantly higher patency than heparin-treated vessels at 1 day (p <0.02), but not at 7 days (p >0.1).
Peripheral blood PT and APTT values for TFPI-treated rabbits were within the normal range (6-8.5 sec. for PT; 14-18 sec. for APTT). The times for each animal showed no differences between pre- and post-treatment values.
Scanning electron microscopy at 15 KV of patent specimens harvested after 1 hour of flow showed at 30× magnification a suture line obscured by thrombus in control (FIG. 4A) and heparin-treated (FIG. 3A) vessels. In contrast, the suture line and surrounding vessel lumen was virtually clear of any sizable thrombotic accumulation in TFPI-treated vessels (FIG. 2A). At higher magnification (100× and 2000×), the controls displayed a mixed thrombus of fibrin strands and platelet aggregates. Heparin-treated vessels had dramatically less fibrin strand formation, with most of the thrombus composed of platelet aggregates and entrapped red blood cells (FIGS. 3B and C). TFPI-treated vessels showed very few organized thrombotic elements, leaving what appeared to be a surface relatively inert to thrombogenesis (FIGS. 2B and C).
Relative to the problems encountered with large vessel, cerebral and coronary thrombosis, reconstructive microvascular surgery has the great advantage of easy and often necessary surgical access to the vessels that are most prone to thrombosis. During the microvascular repair, the surgeon is able to achieve direct exposure of the thrombogenic surface. The standard treatment for injured vessels has been to identify all traumatized portions, to resect and replace (with vein grafts) those considered too severely injured, and to administer systemic antithrombotic agents (heparin, aspirin, dipyridamole, and/or dextran most frequently) to prevent the occurrence of subsequent thrombosis. Several problems may exist, not all of which may be known to the surgeon: an apparently normal vessel surface may in fact have a significant thrombogenic capacity, due to endothelial denudation, fine medial tears, or possibly an activated coagulation pathway on the surface of an otherwise uninjured vessel; the extent of vessel injury may be beyond direct visibility to the surgeon, even with the aid of a microscope; vein grafts may be limited in availability or the selection may be less than ideal; the traumatic incident or an unsuspected systemic coagulopathy may augment the probability for localized or generalized hemorrhage, respectively. For these reasons, the development of an efficacious antithrombotic agent applied through intra-operative topical irrigation in accordance with the present invention is useful and very practical.
Heparin has been shown to have a high affinity for endothelium in vivo. [Hiebert and Jaques, Thrombosis Res. 8, 195-204 (1976); Hiebert and Jaques, Artery 2, 26-37 (1976); Mahadoo et al., Thrombosis Res. 12, 79-90 (1977)]. A significant improvement in microvascular patency with topical heparin compared with unheparinized solutions has been shown experimentally. Reichel et al., J. Hand Suro. 13A, 33-36 (1988), using a rat crushed artery model of thrombosis, demonstrated that heparin, urokinase and other agents moderately enhanced patencies (up to 55%, compared to a control level of 10%) after topical administration only. A more dramatic improvement was noted by Cooley et al. using a 21-residue peptide homologue to the carboxy-terminus of the fibrinogen gamma chain (83% patent, compared with 17% for controls). [6th Ann. Meeting, Amer. Soc. Reconstructive Microsurgery, Toronto, Canada, Sep. 21-23 (1990)]. In accordance with the present invention, comparably high levels of success using a substantially different agent, TFPI.
Recent studies with TFPI using in vitro assays have shown that it forms a complex with tissue factor, and Factors VIIA and Xa, rendering these key clotting cascade enzymes ineffective. [Broze et al., Blood 71, 335 (1988)]. In accordance with the present invention, topical application of TFPI to a traumatized vessel surface may allow it to complex with these enzymes which have been activated through the vascular injury. Following blood flow reestablishment, the capacity of the extrinsic pathway of coagulation at this site is substantially reduced. Since TFPI can be applied locally and in minute quantities, systemic effects are virtually non-existent, as was shown by the foregoing results.
Topical administration of the TFPI can be carried out by conventional methods of administration of topically effective drugs which are well-known to persons skilled in the art. For example, the TFPI can be administered topically in the conventional manner whereby heparin is thus administered as a topical agent during microsurgery. See, e.g., Cooley and Gould, Microsurgerv 12, 281-287 (1991). For conventional methods of topical administration reference can also be had to the numerous texts and treatises in the field of drug administration, e.g., Remington's Pharmaceutical Sciences, Ed. Arthur Osol, 16th ed., 1980, Mack Publishing Co., Easton, PA. Preferably, the TFPI is carried in a physiologically acceptable vehicle or control such as normal saline or buffered saline such as with phosphate buffered saline or other such pharmaceutically acceptable buffers, e.g., HEPES. It can also be administered in a powder, salve or ointment form in conventional vehicles. The amount of TFPI administered to the site of the vascular trauma can be a very small amount, depending in part, on the degree and extent of the trauma. Doses of TFPI of from about 1 μg/ml to about 100 μg/ml applied in a volume of about 0.01 to about 1 ml volume over an exposure period of 1 to several minutes are suitable.
Various other examples will be apparent to the person skilled in the art after reading the present disclosure without departing from the spirit and scope of the invention. It will be understood that all such other examples are included within the scope of the appended claims. | A method for reducing the thrombogenicity of microvascular anastomoses in a warm blooded mammal comprising administering to said mammal at the site of said microvascular anastomoses contemporaneously with microvascular reconstruction of a small but inhibitory effective amount of TFPI. | 0 |
BACKGROUND AND SUMMARY:
With the advent of Surface Mount Devices, Application Specific ICs (ASICs), and double sided boards, board level testing is rapidly becoming a major problem. The test cost also increases dramatically with higher density.
One technique employed in IC designs to improve testability and reduce test cost, is to partition off sections of the main logic design into separately testable modules. The partitioning is accomplished by surrounding the modules with a boundary scan ring, using either Shift Register Latches (SRL) or Scan Registers (SR). This same technique can be used at the boundary of any well-defined logic block. Utilizing a boundary scan technique around an IC's I/O structure provides similar benefits at the board level as at the IC level.
Traditionally in systems employing the boundary scan technique, a trade-off had to be made between the length of the scan and the number of connectors required to interface with the SRLs. If the minimum number of connectors was used (i.e. only that needed to scan in/out the test data/result), then the length of the scan could be tremendous. Regardless of how few points were to be tested, the scan length would not change. Alternatively, the scan length could be broken into smaller segments, but the access lines (connectors) would increase proportionally.
Due to the fixed scan length limitations, it has been impractical to consider adding boundary scan tests internal to an IC where logic blocks may be tested, in conjunction with a system level test (i.e. multi-ICs). This has resulted in having to have a separate testing method for an IC and a board or system.
The present invention allows a continuous scan path to be compressed or expanded so that the path only passes thru the logic sections being tested. This Fast Scan (FSCAN) technique is implemented with a simple logic design that is referred to as the Device Select Module (DSM).
By using FSCAN, devices that are connected on a serial data ring can be selected or deselected allowing the serial path to either flow throw or bypass the device's internal scan path. In addition, FSCAN can be used in IC designs to partition off sections of the core logic for internal scan testing. One advantage of FSCAN over the traditional scan path is that it reduces the test time required to load and unload the scan path and eliminates the need of additional IC pins and board I/O connectors for individual device scan-enable control signals.
Another advantage of the FSCAN technique is that it tends to make the scan path more fault tolerant. For example if a scan sub-ring connected to the main scan path were to experience a short or open condition, causing it to disable the rest of the scan path, it could simply be deselected using the FSCAN's Device Select Module (DSM). Once a DSM is deselected, the main scan path simply bypasses that sub-ring.
It is an object of the present invention to minimize the number of connectors needed for testing.
It is also an object of the present invention to allow boundary scan testing to be performed on a portion of an individual device, an individual device as a whole, a group of devices, and a system.
It is a further object of the present invention to allow a variable scan length so as to minimize scan times.
It is an additional object of the present invention to create a higher degree of fault tolerance.
These and other objects are achieved by a boundary scan test system comprising:
a plurality of logic devices, each having input and output lines for selectively transmitting and receiving data;
a first and second of said logic devices, each further including a logic core and a scan cell having multiple bit positions;
said scan cells being logically located between said logic core and said input and output lines of said first and second logic devices wherein selected bits of said multiple bit positions, under control, are selectively substituted for said data;
each of said first and second said logic devices further including a device select module connected to respective said scan cells of said first and second said logic devices;
said device select module of said first logic device being also coupled to a first bus for receiving test data bits and being further coupled to said device select module of said second logic device via a second bus;
said device select module of said first logic device, in response to selected ones of said test data bits, selectively loading other selected ones of said test data bits into said scan cell connected to said device select module of said first logic device and transmitting other selected ones of said test data bits to said device select module of said second logic device via said second bus; and
said device select modules further controlling the said substitution of data by said connected scan cells.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a number of logic blocks, each surrounded by boundary scan cells controlled by DSMs.
FIG. 2 shows a detailed logic diagram of the presently preferred/embodiment of the DSM used in the invention.
FIG. 3 shows a logic diagram of the presently preferred embodiment of the dual port flip-flop used in the invention.
DETAILED DESCRIPTION OF THE INVENTION
While Device Select Modules (DSMs) may be used in other types of scan designs, the presently preferred embodiment uses the DSMs in a boundary scan. Boundary scan is a testing technique wherein a logic element(s) is surrounded by a scan path, allowing the element(s) to be controlled and observed via the scan path. The boundary scan cells typically consist of serial shift registers. During test each shift register bit has the ability to output data to, or load data from, the element surrounded by the boundary scan. In normal operation each shift register bit has a bypass facility to allow system input and output to propagate thru the shift register unobstructed. These boundary scan cells are known by those skilled in the art.
Referring to FIG. 1, it can be seen that logic device 1 has a logic core 102 that is surrounded by boundary scan cells 101 and 103. Normal incoming data on bus 105 can either be captured by scan cell 101, or passed through to bus 106 feeding logic core 102. Alternatively, data stored in scan cell 101 may be fed onto bus 106 and into logic core 102. Similarly, data output from logic core 102 on bus 107 can either be captured by scan cell 103, or passed through to bus 108. Data can also be output from scan cell 103 onto bus 108.
Logic devices 2 and 100 are similar to logic device 1 in that they have; scan input cells 121 and 131, input bus®s 108 and 112, internal input buses 109 and 113, logic cores 122 and 132, internal output buses 110 and 114, and output buses 111 and 115. Logic devices 1,2, and 100 also have: DSMs 104, 124, and 134; DSM external scan data input buses 150, 153, and 157; DSM external scan data output buses 153, 156, and 160; DSM external control input bus 180; DSM internal scan data output buses 151, 154, and 158; DSM internal scan data input buses 152, 155, and 159; DSM internal control output buses 181, 182, and 183; and internal scan cell connecting buses 161, 162, and 163.
The present invention employs Device Select Modules (DSMs) (104, 124, 134) to provide a mechanism allowing a primary scan ring consisting of external scan data input (150, 153, 157) and output (153, 156, 160) buses along with external control bus (180), to select and access embedded lower level scan rings. In this manner the primary scan ring can be expanded to include one or more sub-rings attached to the primary scan ring. Each sub-ring attached to the primary scan ring may in turn select and access other levels of sub-rings, thus creating a hierarchy of scan sub-rings. After the access to the sub-ring(s) is complete, the primary scan ring may be compressed to its normal length by deselecting the selected sub-ring(s).
A deselected sub-ring is selected by setting its DSM to a logic one during a scan operation. A selected sub-ring is deselected by setting its DSM to a logic zero during a scan. The scan used to select or deselect a DSM(s) is referred to as a Mapping Scan. At power up, or upon reset, all sub-ring DSMs will be initialized to a deselected state.
In addition to providing a hierarchical scan ring structure, the DSM can be used to gate control signals to each sub-ring in the scan network. The scan cells (101, 103, 121, 123, 131, 133) have certain control inputs that allow them to perform scan and test operations. If a DSM is selected, it will allow these control signals to pass through to the scan cells. If deselected, the control signals are gated off.
There are two main advantages in using DSMs. The first is that access time to a selected sub-ring is reduced by not having to clock serial data through the entire length of the expanded scan path. Secondly, an open circuit in one or more of the subrings will not disable the entire scan ring.
In a conventional boundary scan system: bus 150 would be coupled to scan cell 101; scan cell 103 would be coupled to bus 153, which in turn would be coupled to scan cell 121; scan cell 123 would be coupled to bus 156; bus 157 would be coupled to scan cell 131; scan cell 133 would be coupled to bus 160; and control bus 180 (scan clock, scan enable, and other required control inputs) would be coupled to all scan cells 101, 103, 121, 123, 131, and 133. Any data to be loaded into scan cell 131 would thus have to first travel through scan cells 101, 103, 121, and 123. Further, as there is no way to deselect a logic device, all devices are simultaneously caused to shift data from their respective scan cells even if one is interested only in one device. This is turn means that data has to be scanned into all the scan cells for any scan.
As an example of how long a conventional scan loading operation would take, consider the following:
1. Assume that there are 100 logic devices (in FIG. 1, this would be logic devices 1, 2, . . . ,100).
2. Assume that each scan cell is a 100 bit shift register (in FIG. 1 these would be scan cells 101, 103, 121, 123, . . . ,131 and 133).
3. Further assume that the scan clock rate (i.e. how fast data can traverse the scan cells) is 1 MHz.
The amount of time for the operation is therefore: ##EQU1##
While this amount of time does not seem to be particularly long, it must be remembered that each logic device may require thousands of test patterns to be run through in order to test it. In contrast, the present invention allows this time to be dramatically shortened. The DSMs (104, 124, 134) allow each logical device's (1, 2, . . . , 100) scan cells (101, 103, 121, 123, 131, 133) to be selected or deselected, thus varying the length of the scan path. The full functionality of the DSMs will be explained below.
Two scans are required to insert data into the scan cells. The first scan is used to select which DSM(s) is to be placed in the scan path (and thus which scan cells). If a DSM is selected, then it will route the data through its associated scan cells and otherwise will pass data through it. A second scan is used to insert data into, and extract data from, the selected scan cells. An example of this is shown as follows.
1. Assume that there are 100 logic devices (in FIG. 1, this would be logic devices 1, 2, . . . ,100).
2. Assume that each scan cell is a 100 bit shift register (in FIG. 1 these would be scan cells 101, 103, 121, 123, . . . ,131 and 133).
3. Assume that the scan clock rate (i.e. how fast data can traverse the scan cells) is 1 MHz.
4. Assume that logic device 50 is to be loaded with data from its scan cell inputs.
The amount of time for the operation is therefore: ##EQU2##
Total time required using the present invention is 0.0004 seconds as opposed to 0.02 seconds using conventional techniques. Note that in a typical run of 1000 scans cycles, the time for the conventional technique would be 20 seconds. For the present invention, the time would be 0.3001 seconds, as the first scan (i.e. Mapping Scan) only has to be performed once since the last data scan can be used to deselect device 50's DSM. Referring now to FIG. 2, one preferred embodiment of the DSM 104 (from FIG. 1) is shown. The preferred embodiment includes; AND gates 201 and 202, NAND gates 203 and 207, inverter 208, latch 206, Dual port flip-flop 205, and 2-to-1 multiplexor 204. These individual structures may be of the type known in the art.
FIG. 3 illustrates a presently preferred embodiment of the dual port flip-flop 205 as used in FIG. 2. This embodiment includes; D flip-flop 251; and 2-to-1 multiplexor 250. The action of multiplexor 250 is to select the D input of flip-flop 251. If multiplexor select input SEL is low, D0 is connected to the D input of flip-flop 251. If multiplexor input SEL is high, D1 is connected to the D input of flip-flop 251.
By referencing FIGS. 1 and 2, it will now be shown how the inputs to DSM 104 (CTLIN, CKIN, ENAIN -- , RST--, IN1, and IN2) and the outputs from DSM 104 (CTLOUT, CKOUT, ENAOUT -- , OUT2, and OUT1) relate to the buses 150, 151, 152, 153, 180, and 181. Inputs CTLIN, CKIN, ENAIN - and RST are control inputs and all arrive at DSM 104 via bus 180. Input IN1, scan data input, arrives at DSM 104 via bus 150. Input IN2 is from scan cell 103 over bus 152. Outputs CTLOUT, CKOUT, and ENAOUT -- go into both scan cells 101 and 103 via bus 181. Output OUT2 goes into scan cell 101 via bus 151. OUT2 forms the beginning of the internal data scan path which passes thru scan cell 101, over bus 161, thru scan cell 103, and back to DSM 104 input IN2 over bus 152. Output OUT1 is output from DSM 104 via bus 153
The CKIN is the clock used for the scan. As can be seen, this clock is not transmitted to the scan cells (output signal CKOUT) unless the DSM is selected (by action of latch 206) due to the AND gate 202. Similarly, signals CTLOUT and ENAOUT -- are not sent to the scan cells unless the DSM is selected due to AND gate 201 and NAND gate 203 respectively.
The CTLIN signal is used to inform the scan cells (by passing through as output signal CTLOUT) that a certain action is to be performed. In the presently preferred embodiment, this signal is used to latch data in the scan cells by conventional means. In some instances, as more control may be needed, additional lines may be used.
ENAIN -- is an inverted (i.e. low is active) signal that is used to allow data to be scanned into, and out of, scan cells and DSMs. As stated above, the corresponding output signal (ENAOUT -- ) is not output to the scan cells unless the DSM is selected
Latch 206 is constructed such that when input G (from NAND gate 207) is high, then the data present at input D appears as output on Q2. When input G is low, the output Q2 does not change.
Dual port flip-flop 205 is constructed with a clock input CLK, a selector SEL for selecting whether input D1 or input D0 is coupled to output Q1 and a clear input CLR. Note that the CLR input is connected to the RST -- input of the DSM 104.
RST -- is an inverted signal used to reset (i.e. deselect) the DSMs on a global basis. Taking DSM 104 of FIG. 2 as an example, it will now be shown how this is achieved. When the RST - signal is triggered (i.e. pulled low), then the CLR signal is given to dual port flip-flop 205. This causes Q1 to output low. In turn, a 0 appears as the inputs D1 of dual port flip-flop 205, D of latch 206, and M0 of multiplexor 204. The output of NAND gate 207 will be high regardless of what ENAIN -- is. Since G is high (i.e. high from NAND gate 207), then output Q2 will be low as D is low. This deselects the DSM. DSM 104 will remain deselected after the RST -- input goes back to its normal high state if the CKIN and ENAIN -- inputs remain inactive, CKIN is inactive low and ENAIN -- is inactive high.
A DSM may be in one of two states, Selected or Deselected. In each of these two states the DSM can either be Idle, (i.e. scan is disabled) or Active, (i.e. scan is enabled). DSM input ENAIN -- determines the Idle or Active condition for both states. Refer to the preferred embodiment of DSM 104 as shown in FIG. 2 during the following DSM state descriptions.
A DSM is in the Deselect state and Idle if: Q1 and Q2 are low, ENAIN -- is high, and RST -- is high. In this state latch 206 is enabled (G is high by action of Nand gate 207) and Q2 is low as D is low as Q1 from dual port flip-flop 205 is low. Output Q1 is low and remains low regardless of any clock inputs at CLK input from CKIN because of the feedback path from Q1 to D1 back to Q1 (D1 is selected back to Q1 by SEL which is high as ENAIN -- is high). Multiplexor 204 connects Q1 to OUT1 since CTRL is low as Q2 is low. In addition, all control outputs (CTLOUT, CKOUT, and ENAOUT -- ) are disabled by Q2 being low. Also scan data outputs (OUT1 and OUT2) are low because Q1 is low.
A DSM is in the Deselect state and Active if: Q2 is low, ENAIN -- is low, and RST -- is high. In this state latch 206 is not enabled (G is low by action of nand gate 207) and Q2 remains low regardless of the logic level on D. Input DO of dual port flip-flop 205 is directed Q1 by action of SEL being low as ENAIN -- is low. Multiplexor 204 connects Q1 to OUT1 since CNTRL is low as Q2 is low. In this configuration a scan path exist from IN1 to DO, thru dual port flip-flop 205 to Q1, from Q1 to MO, thru multiplexor 204 to OUT1. Control outputs (CTLOUT, CKOUT, and ENAOUT -- )are disable by Q2 being low. While CKOUT is disabled, external scan operations are inhibited between OUT2 and IN2 and thus any external scan path is deselected from the DSM.
A DSM is in the Select state and Idle if: Q1 and Q2 are high, ENAIN -- is high, and RST -- is high. In this state latch 206 is enable (G is high by action of Nand gate 207) and Q2 is high as D is high as Q1 from dual port flip-flop 205 is high. Output Q1 is high and remains high regardless of any clock inputs at CLK input from CKIN because of the feedback path from Q1 to D1 back to Q1 (D1 is selected back to Q1 by SEL which is high as ENAIN -- is high). Multiplexor 204 connects IN2 to OUT1 since CTRL is high as Q2 is high, Control outputs CTLOUT and CKOUT are enabled and ENAOUT -- is disabled (forced high) by ENAIN -- being high. In this configuration scan operations are inhibited thru the dual port flip-flop 205 by the feedback connection (Q1 to D1 to Q1) and externally by ENAOUT -- (external scan enable control) being disable (i.e. forced high) by ENAIN -- being high. However, in this state the DSM can pass control and clock signals from inputs CTLIN and CKIN to outputs CTLOUT and CKOUT to allow attached scan cells to perform certain test operations.
A DSM is in the Select state and Active if: Q2 is high, ENAIN -- is low, and RST -- is high. In this state latch 206 is not enabled (G is low by action of Nand gate 207) and Q2 remains high regardless of the logic level on D. Input DO of dual port flip-flop 205 is directed to Q1 by action of SEL being low as ENAIN -- is low. Multiplexor 204 connects IN2 to OUT1 since CNTRL is high as Q2 is high. In this configuration a scan path exists from IN1 to D0, thru dual port flip-flop 205 to Q1, from Q1 to OUT2, from OUT2 thru an externally connected scan path and back to IN2, from IN2 to Ml of multiplexor 204, and from M1 to OUT1. Control outputs (CTLOUT, CKOUT, and ENAOUT -- ) are enabled by Q2 being high allowing control inputs (CTLIN, CKIN, and ENAIN -- ) to pass thru the DSM and out to externally connected scan cells.
There is a one scan bit overhead for each DSM. This bit is the dual port flip-flop 205 and is used to control the DSM's state (i.e. selected or deselected). The last bit that is clocked into an Active DSM (selected or deselected) before ENAIN -- goes back high (signalling the end of a scan cycle and forcing an "Idle") determines the DSM's next state (selected or deselected). For example, referring to FIG. 2, if DSM 104 is presently in the Select state and Active (Q2 is high and ENAIN -- is low), the last scan bit clocked into Q1 of dual port flip-flop 205 by CKIN is transferred into Q2 of latch 206 after G is driven high by ENAIN -- going high (signalling the end of the select scan cycle and causing the DSM to go Idle). If the last bit (Q1) was a one then Q2 stays at a one and the DSM remains in the Selected state and Idle (Q1, Q2, and ENAIN -- are all high). If the last bit (Q1) was a zero then Q2 changes to a zero and the DSM goes to the Deselect state and Idle (Q1 and Q2 are low and ENAIN -- is high). While Idle, in either the Select or Deselect state, Q1 and thus Q2 cannot chance states (unless RST -- is taken low), thus the next Active scan cycle (ENAIN -- going low) starts off in the state the DSM was placed in after the last Active scan cycle.
When a DSM is Selected and Active, subsequent data is clocked thru the scan loop associated with the DSM before being output to any other DSM (and its loops). Referring to FIG. 1, this would mean (assuming that DSM 104 was selected) that data coming in on bus 150 would pass through DSM 104, onto bus 151, thru scan cell 101, across bus 161, trough scan cell 103, onto bus 152, back through DSM 104 and out onto bus 153. When a DSM is Deselected and Active, subsequent data is clocked only thru the DSM before being output to any other DSM (and its loops). Referring to FIG. 1 again, this would mean (assuming DSM 104 was deselected) that data coming in on bus 150 would enter DSM 104, pass thru the DSM's dual port flip-flop, and exit DSM 104 via bus 153.
While the preferred embodiment of the DSM as shown in FIG. 2 employs a dual port flip-flop, a latch, and other logic gates, it should be apparent that this is only one implementation. One skilled in the art can make many different implementations without departing from the scope of the invention.
The present invention is not limited to having a single DSM per IC. The hierarchical scan can be used to test individual logic blocks within a single IC, or can be used on a more macro approach of allowing scans of logic blocks composed of many ICs. A given DSM may have, in it selectable scan path, a series of other DSMs. In turn, these DSMs may also have in each of their selectable scan paths still another series of DSMs. Thus a true hierarchical scan path structure can be created. Because any one or more of the DSMs (and its associated scan path) in the hierarchy can be selected or deselected, the length of time to perform a test can be as short or long as necessary.
In addition, the present invention is not limited to uses within IC scan designs. A DSM can be implemented as an IC to be used in board designs providing the same hierarchical scan structure at the board level as it provides at the IC level. In the application of a DSM IC, a board scan path could be selected or deselected in the same way as that of an IC's internal scan path.
Also due to the ability to isolate any ring, the present invention allows a test of certain areas even if there is a complete open circuit in some of the rings. Further, a single type of test can be used to isolate faults within an IC, a circuit, a board, and a system. This leads to greatly reduced testing redundancy, higher degree of certainty of a fault, and dramatically reduced testing time and cost.
While references have been made to a specific preferred embodiment of the present invention, no limitations are to be implied from them. The only limitations implied or expressed are those in the claims. | A method of testing circuitry is by the application of scan design which consists of a series of shift registers or latches which form a serial scan path through a logic circuit. The scan path can be used to observe and control logic elements in the design via serial scan operations. The present invention allows a continuous scan path to be compressed or expanded so that the scan path only passes through the desired logic element(s) to be tested. Devices connected on the serial scan path (or ring) can be selected or deselected thus allowing the serial path to either flow through or bypass a given logic circuit's internal scan path. The invention can be used to create a hierarchical scan network consisting of a primary scan ring from which a multiplicity of scan sub-rings may be accessed. | 6 |
[0001] A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent disclosure as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever.
CROSS REFERENCE TO RELATED APPLICATIONS
[0002] The following applications are incorporated herein by reference in their entirety:
“Object-oriented Instruction Set for Use with Resource-constrained Devices”, and “Zero Overhead Exception Handling,” each naming Joshua B. Susser, and Judith E. Schwabe as inventors, which are being filed concurrently with the present application; and “Virtual Machine with Securely Distributed Bytecode Verification”, naming Moshe Levy and Judy Schwabe as inventors, filed Apr. 15, 1997. In addition, an Appendix A entitled “Java Card Virtual Machine Specification: Java Card™ Version 2.1” is attached to this application and forms a part of the present specification.
BACKGROUND
[0006] The present invention relates, in general, to object-oriented, architecture-neutral programs for use with resource-constrained devices such as smart cards and the like.
[0007] A virtual machine is an abstract computing machine generated by a software application or sequence of instructions which is executed by a processor. The term “architecture-neutral” refers to programs, such as those written in the Java™ programming language, which can be executed by a virtual machine on a variety of computer platforms having a variety of different computer architectures. Thus, for example, a virtual machine being executed on a Windows™-based personal computer system will use the same set of instructions as a virtual machine being executed on a UNIX™-based computer system. The result of the platform-independent coding of a virtual machine's sequence of instructions is a stream of one or more bytecodes, each of which is, for example, a one-byte-long numerical code.
[0008] Use of the Java programming language has found many applications including, for example, those associated with Web browsers.
[0009] The Java programming language is object-oriented. In an object-oriented system, a “class” describes a collection of data and methods that operate on that data. Taken together, the data and methods describe the state of and behavior of an object.
[0010] The Java programming language also is verifiable such that, prior to execution of an application written in the Java programming language, a determination can be made as to whether any instruction sequence in the program will attempt to process data of an improper type for that bytecode or whether execution of bytecode instructions in the program will cause underflow or overflow of an operand stack.
[0011] A Java™ virtual machine executes virtual machine code written in the Java programming language and is designed for use with a 32-bit architecture. However, various resource-constrained devices, such as smart cards, have an 8-bit or 16-bit architecture.
[0012] Smart cards, also known as intelligent portable data-carrying cards, generally are made of plastic or metal and have an electronic chip that includes an embedded microprocessor to execute programs and memory to store programs and data. Such devices, which can be about the size of a credit card, typically have limited memory capacity. For example, some smart cards have less than one kilo-byte (1K) of random access memory (RAM) as well as limited read only memory (ROM), and/or non-volatile memory such as electrically erasable programmable read only memory (EEPROM).
[0013] Generally, programs running on a processor of a smart card determine the services offered by the card. As time passes, the programs on the card may need to be updated, for example in order to add a new function or to improve an existing function. To this end, the card should be able to accept new programs which may replace other programs.
[0014] Typically a virtual machine executing byte code (e.g., a full Java virtual machine) requires a sizable amount of memory in loading bytecode and resolving references. Particularly, in the Java virtual machine, symbolic references are used to refer to program elements such as the classes, methods and fields. A Reference to these program elements is resolved by locating the element using its symbolic name. Such operations require a relatively large random access memory (RAM). In an environment that has little RAM, this may not be feasible. Since smart cards are cost-sensitive, they rely on inexpensive, low performance processors and low capacity memory devices. Since cost and power reasons dictate that low-power and low-capacity processor and memory components be deployed in such resource constrained computers, the ability to operate the Java virtual machine on such resource constrained devices is both difficult and yet desirable.
SUMMARY
[0015] In one aspect, a method downloads code to a resource constrained computer. The code is separable into at least one package having at least one referenceable item. The method includes forming the package; forming a mapping of the referenceable item to a corresponding token; and providing the package and the mapping.
[0016] In a second aspect, a method links code downloaded to a resource constrained computer. The method includes receiving the package; receiving a mapping of the referenceable item to a corresponding token; and linking the package using the mapping.
[0017] Advantages of the invention may include one or more of the following. The invention efficiently uses resource on a resource limited device by using smaller storage spaces through unique token identifiers. Further, the invention can link and resolve references to exported items on the resource limited device. Through metadata files such as export files, the invention allows exported elements to be published. Such publication, however, can be done so as to not expose private or proprietary elements and details of the applets and associated libraries. Thereby, various separately developed applications can be loaded onto a resource limited device and share their components with each other without compromising private secure information.
[0018] Moreover, the advantages of an architecture neutral language such as Java can be realized on a resource limited device while preserving its semantics. The tokens may also be used for internal or private elements. Thus, tokens can be assigned to private and package visible instance fields as well as package visible virtual methods. The invention imposes few constraints in assigning tokens, and the token categories may be further defined or optimized for particular applications. As such, the invention supports portable, architecture neutral code that is written once and that runs everywhere, even on resource constrained devices such as smart cards with limited storage capacity.
DRAWINGS
[0019] FIG. 1 illustrates the conversion and loading of hardware platform-independent code onto a smart card.
[0020] FIG. 2 shows a computer system which communicates with the smart card of FIG. 1 .
[0021] FIG. 3 shows a diagram illustrating inter-package dependencies.
[0022] FIGS. 4A and 4B are diagrams illustrating two converter operations.
[0023] FIG. 5 is a diagram illustrating two packages and a package registry for resolving static references.
[0024] FIG. 6 is a flowchart illustrating a linking process in conjunction with the packages of FIG. 5 .
[0025] FIGS. 7A-7I are diagrams illustrating various class, field and method references.
[0026] FIGS. 8A-8I are flowcharts illustrating processes for assigning tokens and supporting tables.
[0027] FIGS. 9A-9C are flowcharts illustrating processes for resolving tokens for instance fields and methods.
DESCRIPTION
[0028] A method is described for representing linking information for object-oriented programs in a compact, secure format. Utilizing this method, said programs can be downloaded, linked and executed on a resource-constrained device. Resource-constrained devices are generally considered to be those that are restricted in memory and/or computing power or speed. Although the particular implementation discussed below is described in reference to a smart card, the invention can be used with other resource-constrained devices including, but not limited to, cellular telephones, boundary scan devices, field programmable devices, personal data assistants (PDAs) and pagers, as well as other small or miniature devices. In some cases, the resource-constrained device may have as little as 1K of RAM or as little as 16K of ROM. Similarly, some resource-constrained devices are based on an architecture designed for fewer than 32 bits. For example, some of the resource-constrained devices which can be used with the invention are based on an 8-bit or 16-bit architecture, rather than a 32-bit architecture.
[0029] Referring to FIG. 1 , development of an applet for a resource-constrained device, such as a smart card 40 , begins in a manner similar to development of a Java program. In other words, a developer writes one or more Java classes and compiles the source code with a Java compiler to produce one or more class files 10 . The applet can be run, tested and debugged, for example, on a workstation using simulation tools to emulate the environment on the card 40 . When the applet is ready to be downloaded to the card 40 the class files 10 are converted to a converted applet (CAP) file 16 by a converter 14 . The converter 14 can be a Java application being executed by a desktop computer. The converter 14 can accept as its input one or more export files 12 in addition to the class files 10 to be converted. An export file 12 contains naming or linking information for the contents of other packages that are imported by the classes being converted.
[0030] In general, the CAP file 16 includes all the classes and interfaces defined in a single Java package and is represented by a stream of 8-bit bytes. All 16-bit and 32-bit quantities are constructed by reading in two or four consecutive 8-bit bytes, respectively. Among other things, the CAP file 16 includes a constant pool component (or “constant pool”) 18 which is packaged separately from a methods component 20 . The constant pool 18 can include various types of constants including method and field references which are resolved either when the program is linked or downloaded to the smart card 40 or at the time of execution by the smart card. The methods component 20 specifies the application instructions to be downloaded to the smart card 40 and subsequently executed by the smart card. Further details of the structure of an exemplary CAP file 16 are discussed in the attached Appendix A at pages 53 through 94.
[0031] After conversion, the CAP file 16 can be stored on a computer-readable medium 17 such as a hard drive, a floppy disk, an optical storage medium, a flash device or some other suitable medium. Or the computer-readable medium can be in the form of a carrier wave, e.g., a network data transmission, or a radio frequency (RF) data link.
[0032] The CAP file 16 then can be copied or transferred to a terminal 22 such as a desktop computer with a peripheral card acceptance device (CAD) 24 . The CAD 24 allows information to be written to and retrieved from the smart card 40 . The CAD 24 includes a card port (not shown) into which the smart card 40 can be inserted. Once inserted, contacts from a connector press against the surface connection area on the smart card 40 to provide power and to permit communications with the smart card, although, in other implementations, contactless communications can be used. The terminal 22 also includes an installation tool 26 which loads the CAP file 16 for transmission to the card 40 .
[0033] The smart card 40 has an input/output (I/O) port 42 which can include a set of contacts through which programs, data and other communications are provided. The card 40 also includes an installation tool 46 for receiving the contents of the CAP file 16 and preparing the applet for execution on the card 40 . The installation tool 46 can be implemented, for example, as a Java program and can be executed on the card 40 . The card 40 also has memory, including volatile memory such as RAM 50 . The card 40 also has ROM 52 and non-volatile memory, such as EEPROM 54 . The applet prepared by the controller 44 can be stored in the EEPROM 54 .
[0034] In one particular implementation, the applet is executed by a virtual machine 49 running on a microprocessor 48 . The virtual machine 49 , which can be referred to as the Java Card virtual machine, need not load or manipulate the CAP file 16 . Rather, the Java Card virtual machine 49 executes the applet code previously stored as part of the CAP file 16 . The division of functionality between the Java Card virtual machine 49 and the installation tool 46 allows both the virtual machine and the installation tool to be kept relatively small.
[0035] In general, implementations and applets written for a resource-constrained platform such as the smart card 40 follow the standard rules for Java platform packages. The Java virtual machine and the Java programming language are described in T. Lindholm et al., The Java Virtual Machine Specification (1997), and K. Arnold et al., The Java Programming Language Second Edition, (1998), which are incorporated herein by reference in their entirety. Application programming interface (API) classes for the smart card platform can be written as Java source files which include package designations, where a package includes a number of compilation units and has a unique name. Package mechanisms are used to identify and control access to classes, fields and methods. The Java Card API allows applications written for one Java Card-enabled platform to run on any other Java Card-enabled platform. Additionally, the Java Card API is compatible with formal international standards such as ISO 7816, and industry-specific standards such as Europay/MasterCard/Visa (EMV).
[0036] Although a virtual machine 49 running on a microprocessor 48 has been described as one implementation for executing the bytecodes on the smart card 40 , in alternative implementations, an application-specific integrated circuit (ASIC) or a combination of a hardware and firmware can be used instead.
[0037] Referring to FIG. 1 , controller 44 uses an installation tool 46 for receiving the contents of the CAP file 16 and preparing the applet to be executed by a processor 48 . The installation tool 46 can be implemented, for example, as a Java program which has been suitably converted to execute on the smart card 40 . In the description below, it is assumed that the controller 44 comprises a virtual machine program 49 running on a microprocessor 48 . The virtual machine 9 need not load or manipulate the CAP file 16 . Rather, the virtual machine 49 executes the applet code in the CAP file 16 . The division of functionality between the virtual machine 49 and the installation tool 46 allows both the virtual machine and the installation tool to be kept relatively small. In alternative implementations, the controller 44 can be hardwired, for example, as an application-specific integrated circuit (ASIC) or it can be implemented as a combination of a hardware and firmware.
[0038] The smart card platform, which can be used for other resource-constrained devices as well, supports dynamically created objects including both class instances and arrays. A class is implemented as an extension or subclass of a single existing class and its members are methods as well as variables referred to as fields. A method declares executable code that can be invoked and that passes a fixed number of values as arguments. Classes also can implement Java interfaces. An interface is a reference type whose members are constants and abstract methods. The virtual machine 49 may include an interpreter or native implementation which provides access to a runtime system which includes the Java Card API and supporting functionalities.
[0039] As shown in FIG. 2 , a computer 221 is equipped with a card acceptance device 24 for receiving the card 40 of FIG. 1 . The computer 22 may be connected to a network 45 which communicates with a plurality of other computing devices, such as a server 47 . It is possible to load data and software onto a smart card over the network 45 using card equipped devices. Downloads of this nature can include applets or other programs to be loaded onto a smart card as well as digital cash and other information used in accordance with a variety of electronic commerce and other applications. The instructions and data used to control processing elements of the card acceptance device and of the smart card may be stored in volatile or non-volatile memory or may be received directly over a communications link e.g., as a carrier wave containing the instructions and/or data. Further, for example, the network 45 can be a LAN or a WAN such as the Internet or other network.
[0040] FIG. 3 shows a diagram illustrating typical hierarchical dependencies among a group of program packages (including both Application Program Interfaces (APIs) and program applets) loaded onto a smart card 40 . Applications may be loaded onto the smart card 40 incrementally and linked on-card for execution so that the functionality of the smart card 40 may be updated with additional capabilities in addition to factory-programmed functionalities. In the diagram, a Java language framework 50 and a Java Card framework 52 exist at a Java Card API level. Above the Java Card API level is a custom API level with one or more custom frameworks 54 . The custom framework 54 may be supplied by one or more value added providers through various software development kits (SDKs) to extend an existing framework or other API. At the highest level is an application level where various applets 56 , 58 and 60 reside.
[0041] As shown in FIG. 3 , a package may depend on other packages at the same API level or from those packages in lower API levels. For example, the applet 58 may refer to program elements in the applet 58 and the Java Card framework 52 may have dependencies from the Java language framework 50 . Moreover, the custom framework 54 at the custom API level and the applets 58 and 60 may have references that depend from the Java Card framework 52 . In turn, the applets 56 and 58 may have references that depend from the custom framework 54 . The applet 56 and the custom framework 54 may also depend from the Java language framework 50 . Although the example of FIG. 3 shows linear dependencies, non-linear dependencies such as circular dependencies may be supported using a suitable converter 14 and installation tool 46 .
[0042] The conversion of a set of class files from, e.g., a Java application, to a CAP file 74 can generally occur on a desktop computer in preparation for installation on a smart card 40 . The desktop computer 22 is generally not as resource constrained as a typical smart card 40 . Additionally, the converting operation may be conducted on other suitable platforms as well.
[0043] FIG. 4A shows a system for converting a package, which may define an applet or a library in preparation for downloading onto smart card 40 . Converter 72 receives data input from one or more class files 70 , which define the functionality of an applet. The converter 72 in turn generates a Java Card CAP file 74 suitable for downloading.
[0044] As discussed in greater detail below, the CAP file 74 contains an export component 82 for resolving references to elements in its package, where those elements may be referenced by other packages. The export component 82 contains entries for static items such as classes, methods and fields. References to dynamic items such as instance fields, virtual methods and interface methods are not required to be presented in the export component, but may be handled according to processes described below.
[0045] In resource constrained devices, the use of Unicode strings to represent items consumes memory and processor resources. In place of strings, the export component 82 maps tokens, or simple unique numerical values, to particular elements defined in other components in the CAP file 74 . The token values used to represent these elements in the export component match those published in a corresponding Export File 80 .
[0046] In more detail, CAP file 74 has, among others, a header component 76 , a constant pool 78 , a method component 80 , and an export component 78 . The constant pool 78 typically includes one or more class, field and method references so that generally references to program elements or items are made indirectly through the package's constant pool 78 . Method component 80 contains all the methods implemented by the applet package represented by CAP file 74 . Method references resolve to methods located in the method component. Class and static field references resolve to locations in class components and static field components, respectively. These are described further in Appendix A.
[0047] Export component 78 includes one or more entries with a token value 84 and corresponding program element link information 86 that describes where in the package defined in the CAP file A 74 a particular program element is to be found. The link information is specific to the content of the CAP file 74 , not the internal representation on a particular card. This component, therefore, does not describe card-specific private or secure information.
[0048] Converter 72 can also generate an Export file 80 during conversion of class files into a CAP file 74 . One Export file is generated for each CAP file. Export file 80 typically has one or more entries with a symbolic name 90 for a particular program element in CAP file 74 and its corresponding token value 92 . Export file 80 provides information about each externally accessible program element of the package of class files and program information in CAP file 74 that may be referenced (imported) by a second package into a second CAP file (described further below). For example, Export file 80 contains references to all of the public classes and interfaces defined in one Java package, and all of the public and protected fields and methods defined in those classes and interfaces. The Export file 80 also contains a mapping of these program elements or items to tokens which can then be used to map names for imported items to tokens during package conversion. The export file does not expose private or proprietary details of the applets and associated libraries. Thereby, various separately developed applications can be loaded onto a resource limited device and share their components with each other without compromising private secure information. The Export file 80 does not expose private or proprietary elements and details of the applets and associated libraries, separately developed applications can be loaded onto the card 40 and share their exported elements with each other without compromising private secure information.
[0049] With reference to FIGS. 3 and 4 , if a number of class files 70 comprising javacard.framework API 52 were being converted, the Export file 80 generated during conversion would allow other applet programs, being converted separately, to know which tokens to use in order to externally reference items of the javacard.framework.API. For instance, if an applet references the framework class PIN, the Export file 80 for the javacard.framework contains an entry for class javacard.framework.PIN along with its respective token. Converter 72 would place this token in the constant pool of the CAP file of the new applet, to represent an unresolved reference to that class in the framework. As explained further below, during applet execution, the token can be used to locate the referenced item in the export component 78 of the framework API package to retrieve the element link information. For example, the link information of a method may provide information to locate the appropriate method contained in the method component 80 of that package.
[0050] FIG. 4B shows converter 72 converting a second package of class files 94 , where those class files 94 import elements from the class files from the first package 70 ( FIG. 4A ). For example, the second package can be a set of applet classes that rely upon certain classes contained, e.g., in a javacard.framework library package, that has been previously converted (as described above with respect to FIG. 4A ). Converter 72 receives data input from class files 94 and from one or more Export files 80 from previously converted packages. Converter 72 generates a CAP file 100 suitable for downloading onto, e.g., the smart card 40 .
[0051] CAP file B 100 for the second package includes an import component 104 with a list of all packages referenced by the applet classes. Each such external package reference comprises a mapping 106 between an internal package token and an external unique Application Identifier (AID) for that package. Each package token is used in other components within CAP file 100 to identify a particular referenced external package in a concise manner, thereby reducing the footprint size of the representation of the applet.
[0052] The CAP file 100 also has, among others, a header component 102 , an import component 104 and a constant pool 108 . The constant pool 108 includes one or more class references 110 , which map each class reference with corresponding package tokens, and class tokens, thereby mapping the specified class to its corresponding external package and class within that package. The use of these tokens is further described below. The constant pool 108 can also include one or more method references 112 which similarly map each method reference with corresponding package tokens, class tokens and method tokens. The constant pool 108 can also include one or more field references 114 , each with its package token, class token, and field token, respectively.
[0053] Generally, references to program elements or items are made indirectly through the constant pool 108 of each package. References to items in other packages are called external, and are represented in terms of tokens. References to items in the same CAP file are called internal, and can be represented either in terms of tokens, or in a different internal format (such as pointers to locations within the CAP file). For example, the external reference 110 to a class is composed of a package token and a class token. Together those tokens specify a certain class in a certain external package. An internal reference to a class may be a pointer to the class structure's location within the CAP file. Alternatively, the external token system can be used internally as well. The external references 112 - 114 refer to a static class member, either a field or method, with a package token, a class token, and a token for the static field or static method. An internal reference to a static class member may be a pointer to the item's location in the CAP file, but can also use the token system. References to instance fields, virtual methods and interface methods consist of a class reference and a token of the appropriate type. The class reference indicates whether the reference is external or internal.
[0054] External references in a CAP file can be resolved on a card from token form into the internal representation used by the Java Card virtual machine. A token can only be resolved in the context of the package which defines it. Just as the export file maps from a package's externally visible names to tokens, there is a set of link information for each package on the card that maps from tokens to resolved references. In this manner, the converter 97 processes both the class files 92 and Export file 94 , creating an image suitable for downloading the applet onto a resource limited device and resolving references (linking) to the first package.
[0055] After the pre-processing performed in FIGS. 4A and 4B , the CAP file of FIG. 4B may be downloaded to the smart card 40 or a resource constrained device that contains the CAP file of FIG. 4A . FIGS. 5 and 6 illustrate in greater detail how token-based linking is done for static elements on the smartcard 40 or a small device. The static elements include elements whose exact representations are identifiable by the converter during the conversion process.
[0056] In FIG. 5 , an image 200 of a package P 2 has been loaded from, e.g., CAP File B 100 , onto card 40 and can be linked to a prior package P 1 prior to or during execution. Program elements in package P 2 200 may include references to methods and other data in external package P 1 which already exists as an image 174 on card 40 (of CAP File A 74 ). The image 174 includes, among other things, a header component 176 , a constant pool 178 , a method component 180 , and an export component 182 which contains a list of tokens for all exported static items 185 . To aid the resolution of the reference to an external package, a package registry 120 is created on card 40 to provide information used to locate one or more external packages, including image 174 of package P 1 which contains particular methods required by image 200 of the package P 2 .
[0057] The image 200 of the package P 2 includes, among other things, a header component 202 , an import component 204 , a constant pool 208 , and a method component 216 , all corresponding to the respective components 102 , 104 , 108 , and 116 in CAP file B 100 . The general organization of these components is described above with respect to the CAP files and in Appendix A. Typically, the method component 216 will include program references such as “new” ( 218 ), “invokestatic” ( 220 ) and “getstatic_b” ( 222 ) along with their respective invoked class references, method references, and field references.
[0058] FIG. 6 shows a link process 140 for package P 2 200 of FIG. 5 . When an executing method in method component 216 invokes a particular method, e.g., Method T, in method component 180 that is located in an external package (package 1 ), linking is required (step 142 ). Using the index provided as an operand to the instruction, the process 140 locates and retrieves in constant pool 208 the matching method reference 212 (step 144 ). As described below, the method reference consists of a package token, class token, and method token which are used to locate that particular method in an external package. Next, process 140 examines the import component 204 to find the unique AID of external package P 1 based on the retrieved package token (step 146 ). Package registry 120 is then examined to find the location of the package P 1 based upon the AID (step 148 ). Once the image 174 for package P 1 is found from package registry 120 , export component 182 of image 174 is searched to locate the class with the specified class token (step 150 ). The program link information for the desired method, e.g., Method T, is then found by searching the list of methods associated with the particular class found in step 150 , to locate the method with the specified method token (here method token Y corresponds to Method T of package P 1 174 ) (step 152 ). Finally, the location of the specified method, e.g., Method T, in method component 180 is determined based on the link information provided for the method in the export component 182 (step 154 ).
[0059] Using the process of FIG. 6 , a package may be downloaded onto a card and prepared for execution by a virtual machine. This process is called “installation.” Various installation processes may be used which differ in the order of processing and linking operations (when the data is received on the card and when it is stored). These installation processes may be optimized based on available resources on the card. In one implementation, no linking occurs and as such, as data is received, it is immediately stored. During interpretation or execution of the code, resolution of external references occur. As such, this implementation is used in a larger (less constrained) small device because all temporary link information is stored permanently on this card.
[0060] As discussed above, instead of Unicode strings as are used in Java class files, tokens are used to identify items in a CAP file and to resolve references on the resource limited device. Tokens for an API are assigned by the API's developer and published in the package export file(s) for that API. Since the name-to-token mappings are published, an API developer may choose any order for tokens within constraints of the invention.
[0061] Together, FIGS. 5 and 6 describe resolution of references to static items, that is, classes, static fields, and static methods. The implementations of these items are fully locatable during compilation and conversion. In contrast, during compilation and conversion, references to instance fields, virtual methods and interface methods are not statically bound to particular implementations. Those items require additional information which is only available with reference to an instance at runtime. Reference resolution to these types are described in reference to FIG. 9A-9C .
[0062] Token assignments for virtual methods preserve relationships within object oriented class hierarchies. Tokens for virtual methods and interface methods are used as indices into virtual method tables and interface method tables, respectively. A particular card platform can resolve tokens into an internal,representation that is most useful for that implementation of a resource limited device VM.
[0063] Some tokens may be resolved to indices. For example, an instance field token may be resolved to an index into a class instance. In such cases, the token value can be distinct from and unrelated to the value of the resolved index.
[0064] Each kind of item in a package has its own independent scope for tokens of that kind. Sample token range and assignment rules for each kind of reference are listed below. Other ranges and assignments of tokens can be made.
Token Type Range Type Scope Package 0-127 Private CAP file Class (Including 0-255 Public Package Interfaces) Static Field 0-255 Public Class Static Method 0-255 Public Class Instance Field 0-255 Public or Private Class Virtual Method 0-127 Public or Private Class Hierarchy Interface Method 0-127 Public Class
[0065] FIGS. 7A-7I are diagrams illustrating representations of references. FIGS. 7A-7C describe references to imported elements, while FIGS. 7D-7I describe references to internal items, some of which use tokens as well.
[0066] FIG. 7A shows a class reference to an external class 180 . The class reference of FIG. 7A includes a package token and a class token. FIG. 7B shows a representation of an external field reference. The external field reference 182 includes a package token, a class token and a field token. FIG. 7C shows a representation of an external method reference 184 . The external reference 184 includes a package token, a class token, and a method token. It is to be noted that, for virtual methods, the high bit of the method token is set to zero. The setting of the high bit indicates that the method is accessible outside of the defining package. The high bit may be the most significant bit such as the 7th bit of a byte, 15th bit of a word, or the 23rd bit of a three-byte unit.
[0067] The high bit of a package token is set to indicate an imported package. This is used to distinguish between external and internal references. As shown in FIGS. 7D-7I , references to internal elements have their high bits set to zero. The formats of FIGS. 7D-7I are examples of extending token usage, in selected cases, to internal items.
[0068] FIG. 7D shows a representation of an internal class reference 186 . The internal class reference 186 includes an offset to a class information structure in the class component. FIG. 7E shows a representation of a static field reference 188 for an internal field. As such, the static field reference 188 has a field which is set to zero and a field for including an offset to a static field in the static field image. FIG. 7F is a representation of a static method reference 190 for internal methods. The static method reference 190 includes a field of padding, that is set to zero, to make the reference the same size as an imported method reference. The static method reference 190 also includes a field which provides information relating to an offset to a static method in the method component.
[0069] FIG. 7G shows a representation of an instance field reference 192 for an internal field. In FIG. 7G , the instance field reference 192 includes an offset to a class information structure in the class component, as well as a field token. FIG. 7H shows a virtual method reference 194 to a public or protected method for an internal method. The virtual method reference 194 includes an offset to a class information structure in the class component, a field which is cleared to indicate an externally accessible virtual method and to conform to the format in FIG. 7C . The virtual method reference 194 also includes a method token.
[0070] Finally, FIG. 7I shows a representation of a virtual method reference 196 to a package visible method for internal methods. The virtual method reference 196 includes an offset to the class information structure and the class component, a field which is set to one indicating that the reference's scope is internal to the package. The reference 196 also includes a method token.
[0071] FIGS. 8A-8I are flowcharts illustrating processes for assigning tokens and constructing virtual method tables and interface method tables. These processes can be performed by a converter 72 , as discussed above. Referring now to FIG. 8A , a process 230 for assigning package tokens is shown. Generally, package references from within a CAP file are assigned tokens which are used only in the CAP file.
[0072] The process 230 first obtains a list of imported packages (step 231 ). The list can be in any order. Next, the process 230 checks whether the number of packages being imported exceeds a predetermined threshold such as 127 (step 232 ). In this case, a limit of 127 is used in order to represent a package token in 8-bits, with the high bit reserved. If the number of imported packages exceeds the predetermined threshold such as 127, the process fails (step 205 ).
[0073] Alternatively, the process 230 initializes the current token value to zero (step 233 ). Next, the process 230 initializes the current package to the first package in the list (step 234 ). The process 230 then checks whether the current package is null (step 235 ). If not, the process 230 assigns the current token to the current package (step 236 ). Next, the process 230 increments the current token value by one (step 237 ), and sets the current package to the next package in the list (step 238 ).
[0074] From step 235 , in the event that the current package is null, indicating there are no more imported packages, the process 230 records the token in an Import component (step 239 ) and exits. References to items in imported packages use token values recorded in the imports component.
[0075] Turning now to FIG. 8B , a process 240 for assigning class and interface tokens is shown. The process 240 first obtains an arbitrarily ordered list of public class and interfaces (step 241 ). Next, it checks whether the number of classes and interfaces exceed a predetermined value such as 256 which is the maximum number of classes that can be represented in 8-bits (step 242 ). If so, the process 240 fails (step 205 ). Alternatively, the process 240 initializes the current token value to zero (step 243 ). It also initializes the current item to the first class or interface in the list obtained in step 241 (step 244 ). Next, the process 240 determines whether the current item is null which indicates that no more classes or interfaces remain in the list (step 245 ). If not, the process 240 assigns a current token value to the current item, which may be a class or an interface item (step 246 ). Next, the process 240 increments the current token value by one (step 247 ) and sets the current item to the next class or interface in the list (step 248 ) before looping back to step 245 . From step 245 , in the event that a current item is null, indicating no more classes or interfaces exist in the list, the process 240 records a token value in the Export component table (step 249 ). Additionally, the process 240 publishes the token values in the export file (step 251 ) and exits.
[0076] FIGS. 8C-1 and 8 C- 2 handle the static field tokens, with FIG. 8C-2 being an optimized version of FIG. 8C-1 by inlining compile-time constants. Externally visible static fields in a package are assigned public tokens. Package-visible and private static fields are not assigned tokens. FIG. 8C-2 describes a process 280 which is an optimization of process 250 . In this optimization, tokens are not assigned for final static fields which are initialized to compile-time constants. In this case, the fields are not linked on-card.
[0077] Turning now to FIG. 8C-1 , a process 250 is shown for assigning static-field tokens in a public class or interface. The process 250 first obtains an arbitrarily ordered list of public and protected static fields in the public class or interface (step 252 ). Then the process 250 sets the current token value to zero (step 254 ) and initializes the current field to the first static field in the list (step 256 ). The process 225 then determines whether the current field is null, indicating no more fields are left (step 258 ). If not, the process 250 assigns the current token value to the current field (step 260 ) and increments the current token value by one (step 262 ). The process 250 then sets the current field to the next static field in the list (step 264 ) before it loops back to step 258 .
[0078] From step 258 , in the event that the current field is null, indicating no more fields are left, the process 250 determines whether the current token is greater than a predetermined value such as 255 which is the maximum number of tokens that can be represented in 8-bits (step 266 ). If so, the process 250 fails (step 205 ). Alternatively, the process 250 records the token values in the export component table if the export component is to be generated (step 268 ). Finally, the process 250 publishes the token values in the export files (step 270 ).
[0079] Referring now to FIG. 8C-2 , a process 280 which optimizes the assignment of static field tokens in a public class or interface is shown. The optimization reduces memory consumption by eliminating compile-time constants and replacing references to the constants inline in the bytecode. The process 280 obtains a list of public and protected static fields in a public class or interface (step 282 ). The process 280 then sets the current token value to zero (step 284 ) and initializes the current field to the first static field in the list (step 286 ). The process 280 then checks whether the current field is null (no more fields) (step 288 ). If not, the process 280 determines whether the current field is a compile-time constant (step 290 ). If so, the process 280 assigns a value such as 0xFF as a token value of the current field (step 296 ). Alternatively, if the current field is not a compile-time constant, the process 280 assigns a current token value to the current field (step 292 ) and increments the current token value by one (step 294 ). From step 294 and 296 , the process 280 then sets the current field to the next static field in the list (step 298 ) before looping back to step 288 to continue processing the tokens.
[0080] From step 288 , in the event a current field is null (no more fields), the process then checks whether the current token exceeds a predetermined threshold such as 255 which is the maximum numbers that can be represented using 8-bits (step 300 ). If so, the process 280 fails (step 205 ). Alternatively, if exporting, the process 280 records the token values in the export component (step 302 ). The process then publishes the token values in the Export file with the compiled time constants (step 304 ) so referencing packages can inline the respective values, before exiting.
[0081] Turning now to FIG. 8D , a process 310 for assigning static method tokens in a public class is shown. The process 310 first obtains a list of public and protected static methods and constructors in a public class (step 312 ). The process 310 then checks whether the number of static methods exceed a predetermined value such as 256 (step 314 ). If not, the process sets the token value to zero (step 316 ) and initializes the current method to the first static method in the list (step 318 ). Next, the process 310 checks whether the current method is null (no more methods) (step 320 ). If not, the process 310 assigns a current token value to the current static method (step 322 ) and increments the current token value by one (step 324 ). The process 310 then sets the current method to the next static method in the list (step 326 ) before looping back to step 320 .
[0082] From step 320 , if the current method is null (no more methods) the process records the token value in the export component (step 328 ) and publishes the token values in the export file (step 330 ) before exiting.
[0083] FIGS. 8E-1 and 8 E- 2 relate to instance field token assignment schemes. FIG. 8E-1 shows a general process for assigning field tokens, while FIG. 8E-2 is one optimized process which extends token assignments to internal (or package-visible and private) fields, groups fields of type reference and allows tokens to be easily mapped to offsets within instances.
[0084] Turning now to FIG. 8E-1 , a process 340 for assigning instance field tokens in a public class is shown. First, the process 340 gets a list of public and protected instance fields in a public class (step 342 ). It then checks whether the number of instance fields exceeds a predetermined value such as 256 (step 344 ) and if so, fails (step 205 ). Alternatively, the process 340 sets the current token value to zero (step 346 ) and initializes a current field to the first field in the list (step 348 ). Next, the process 340 checks whether the current field is null (step 350 ). If not, the process 340 assigns a current token value to the current instance field (step 352 ) and increments the current token value by one (step 354 ). From step 354 , the process sets the current field to the next instance field in the list (step 360 ) before looping back to step 350 . From step 350 , in the event that the current field is null, the process 340 publishes the token values in the export file (step 362 ) and exits.
[0085] Various factors may be considered in optimizing the general approach of FIG. 8E-1 . Generally, the ordering of the tokens remains flexible so that the token arrangement can be adapted to specific implementations. FIG. 8E-2 describes a constrained assignment scheme as shown in the example below:
Visibility Category Type Token public and primitive boolean 0 protected = public byte 1 tokens short 2 references byte[ ] 3 Applet 4 package and references short[ ] 5 private = private Object 6 tokens primitive int 7 short 9
[0086] Referring now to FIG. 8E-2 , a process 370 for optimizing the above assignment of instance field tokens is shown. As before, the process 370 gets a list of all instance fields in a class (step 372 ). Next, the process 370 checks whether the numbered instance fields exceeds a predetermined value such as 256 (step 374 ). If so, the process 370 fails (step 205 ) and if not, the process 370 sorts the list into categories including public and protected primitive types first, public and protected reference types second, package and private reference types third, and package and private primitive types last (step 376 ). The token value is set to zero (step 378 ) and the current field is initialized to the first instance field in the list (step 380 ). Next, the process 370 checks whether the current field is null (step 382 ). If not, the process assigns a current token value to the current field (step 384 ) and increments the current token value by one (step 386 ). The process 370 then determines whether the current field is an integer type (step 388 ). The integer type takes two slots to allow tokens to be easily mapped to instances. If so, the current token value is incremented by one (step 390 ). From step 388 or step 390 , the process 370 sets the current field to the next instance field in the list (step 392 ) before looping back to step 382 .
[0087] From step 382 , if the current field is null, the process 370 publishes the token values of the public and protected instance fields in the export file (step 394 ) before exiting.
[0088] FIGS. 8F-1 and 8 F- 2 assign tokens for virtual methods. FIG. 8F-1 shows a general scheme for virtual method token assignment, while FIG. 8F-2 extends token assignment to package visible virtual methods.
[0089] Referring now to FIGS. 8F-1 and 8 F- 2 , processes for assigning virtual method tokens are shown. Generally, virtual methods defined in a package are assigned either exportable or internal tokens. Exportable tokens are assigned to public and protected virtual methods; in this case, the high bit of the token is zero. Internal tokens are assigned to package visible virtual methods; in this case the high bit of the token is one. Since the high bit is reserved, these tokens range from 0 to 127, inclusive.
[0090] Exportable tokens for the externally visible introduced virtual methods in a class are numbered consecutively starting at one greater than the highest numbered exportable virtual method token of the class's superclass. If a method overrides a method implemented in the class's superclass, that method uses the same token number as the corresponding method in the superclass so that overridden methods may be identified as being related to the method they override.
[0091] Internal virtual method tokens are assigned differently from exportable virtual method tokens. If a class and its superclass are defined in the same package, the tokens for the package-visible introduced virtual methods in that class are numbered consecutively starting at one greater than the highest numbered internal virtual method token of the class's superclass. If the class and its superclass are defined in different packages, the tokens for the package-visible introduced virtual methods in that class are numbered consecutively starting at zero. If a method overrides a method implemented in the class's superclass, that method uses the same token number as the corresponding method in the superclass. For background information, the definition of the Java programming language specifies that overriding a package-visible virtual method is only possible if both the class and its superclass are defined in the same package. The high bit of the byte containing a virtual method token is always set to one, to indicate it is an internal token. The ordering of introduced package virtual method tokens in a class is not specified.
[0092] In FIG. 8F-1 , the process 400 first gets a list of public and protected virtual methods in a class (step 402 ). The process 400 then checks whether the class has a superclass (step 404 ). If so, the process 400 further checks whether the superclass is in the same package (step 406 ). From step 406 , in the event that the superclass is in the same package, the process finds the superclass (step 408 ) and obtains the virtual methods and tokens of the superclass (step 412 ). The set of virtual method includes those defined all of the superclasses of the superclass. From step 406 , in the event of the superclass is not in the same package, the process 400 finds the superclass in the export file of the imported package (step 410 ) and then proceeds to step 412 . From step 412 , the process 400 initializes a current token value to the maximum superclass virtual method token and increments its value by one (step 414 ), ensuring that there will not be token collisions within the hierarchy.
[0093] From step 404 , in the event that the class does not have a superclass, the process 400 initializes to zero the current token value (step 416 ). From step 414 or step 416 , the process 400 initializes the current method to the first virtual method in the list (step 418 ). Next, the process 400 determines whether the current method is null (step 420 ). If not, the process then determines whether the current virtual method is defined by the superclass (step 422 ). If so, the method is an override method and the same token value is assigned to the current method as the one assigned to the overridden method in the superclass (step 424 ) before looping back to step 420 .
[0094] From step 422 , in the event that the current virtual method is not defined by the superclass, it is an introduced method. In that case, the process 400 assigns a current token value to the current method (step 426 ) and increments the current token value by one (step 428 ). The process 400 then sets the current method to the next method in the list (step 430 ) before looping back to step 420 . From step 420 , in the event that the current method is null, the process 400 checks whether the current token value exceeds a predetermined value such as 127 (step 432 ). If so, the process 400 fails (step 205 ). Alternatively, if the token value is not greater than 127, the process 400 publishes the token values in the export file along with the inherited methods and their token values (step 434 ) before exiting. The process of FIG. 8F-1 can also be used for assigning tokens to public and protected virtual methods in a package visible class as shown in FIG. 8F-2 .
[0095] In FIG. 8F-2 , a process 440 for extending token assignment to package visible virtual methods in a class is shown. The process 440 first gets a list of package visible virtual methods in the class (step 442 ). Next, it checks whether the class has a superclass (step 444 ). If so, the process then checks whether the superclass is in the same package (step 446 ). If so, the process 440 then finds a superclass in the same package (step 448 ), gets the package visible virtual methods and tokens of the superclass (step 450 ) and initializes the current token value to the maximum superclass virtual method token plus one (step 452 ) to avoid token collisions within the hierarchy that is scoped to the package. This ensures that token values previously assigned within superclasses are not reused for introduced methods. It is to be noted that step 450 may be recursive up to the superclasses in the same package.
[0096] From step 444 , in the event a class does not have a superclass, or from step 446 , in the event that the superclass is not in the same package, the process 440 sets the current token value to zero (step 454 ). Particularly, if the superclass is not in the same package, package visible virtual methods of that superclass are not accessible and thus not included in step 454 . These potential methods are accounted for when resolving references to virtual methods as described above in FIGS. 9D-2 and 9 D- 3 .
[0097] From step 452 or step 454 , the process 440 initializes the current method to the first virtual method in a list (step 456 ). Next, the process 440 checks whether the current method is null (step 458 ). If not, the process 440 checks whether the current virtual method is defined by a superclass (step 460 ). In this case the method is an override method. If so, the process 440 then assigns the same token value to the current method as assigned to the overriden method in the superclass (step 462 ) before looping back to step 458 .
[0098] From step 460 , if the current virtual method is not defined by its superclass it is an introduced method. In this case, the process 440 assigns a current token value to the current method and sets the high bit to one (step 464 ). The high bit of the virtual method token is used to determine whether it is a public or private virtual method token. Next, the process 440 increments the current token value by one (step 466 ) and sets the current method to the next method in the list (step 468 ) before looping back to step 458 .
[0099] In step 458 , in the event that the current method is null, the process 440 determines whether the current token value exceeds a value such as 127 (which is the maximum number representable in 8-bits with the high bit reserved) in step 470 . If so, the process 440 fails (step 205 ). Alternatively, in the event that the current token value is within range, the process 440 exits. Note that tokens for package visible virtual methods are used internally and are not exported.
[0100] Virtual method references can only be resolved during execution. The virtual method table allows the card to determine which method to invoke based on the token as well as instances of the method's class. The token value is used as an index to the virtual method table. FIG. 8G-1 shows a process 480 for constructing public virtual method tables in a class. First, a list of public and protected virtual methods in the class is obtained (step 482 ). Next, the process 480 gets virtual methods and tokens of a superclass (step 484 ). Step 484 is recursive, including all of the superclasses of the class. The process 480 then creates a table, ordering virtual methods by token values (step 486 ) and eliminates duplicate virtual methods. Duplicates are generated for overridden methods. In this case, the method defined in the current class is represented in the method table instead of the one defined in a superclass. The process 480 then sets a count to a maximum virtual method token class in step 488 and records a table and count in the class component (step 490 ) before exiting.
[0101] Turning now to FIG. 8G-2 , a process 500 which optimizes the construction of public virtual method tables in the class is shown. The process 500 decreases the size required for storing a virtual method table by removing overlapping elements in a superclass' virtual method table.
[0102] The process 500 first gets a list of public and protected virtual methods in a class (step 502 ). Next, the virtual methods and tokens of the superclass are obtained (step 504 ). Step 504 is recursive, including all of the superclasses of the class. Next, the process 500 initializes a table by ordering virtual methods obtained in steps 502 and 504 by token values (step 506 ). This process assumes the process has at least one entry. The process 500 then initializes a count to a maximum virtual method token plus one (step 508 ). The process 500 also sets the base count to zero (step 510 ). Next, process 500 checks whether the count is positive (step 512 ). If so, the process checks whether the first entry in the table is defined by the current class (step 514 ). If not, the process removes the method from the table and shifts the remaining methods up in the table (step 518 ). The process 500 then decrements the count by one (step 520 ) and increments the base count by one (step 522 ) before looping back to step 512 .
[0103] From step 514 , in the event that the first entry is defined in the current class, or in the event that the count is zero in step 512 , the process 500 proceeds to record the table, count and base in the class component (step 516 ) before exiting.
[0104] FIGS. 8H-1 and 8 H- 2 show a process 524 for assigning interface method tokens in a public interface. Particularly, FIG. 8H-2 shows in more detail step 526 of FIG. 8H-1 .
[0105] Referring now to FIG. 8H-1 , the process 524 assigns interface method tokens in a public interface. The process 524 initially obtains a set of interface methods in the public interface (step 525 ). Next, the process 524 obtains a list of superinterfaces of the interface (step 526 ). This operation is defined in more detail in FIG. 8H-2 . The process 524 then merges the set of methods defined by the interface and by its superinterfaces (step 527 ). Next, the process 524 checks whether or not more than 256 methods exist (step 529 ). If so, the process 524 fails (step 205 ). Alternatively, if less than 256 methods exist, the process 524 sets the current token value to zero (step 530 ) and initializes the current method to the first method in the method of set of methods (step 532 ). Next, the process 524 checks whether the current method is null (step 533 ). If not, the process 524 assigns the current token value to the current interface method (step 534 ), increments the current token value by one (step 535 ), and sets the current method for the next method in the set (step 536 ) before looping back to step 533 .
[0106] From step 533 , if the current method is null, the process 524 publishes the superinterface list associated with the interface and the method token values in the export file (step 537 ) and exits.
[0107] Referring now to FIG. 8H-2 , step 526 of FIG. 8H-1 is shown in more detail. First, the process of FIG. 8H-2 selects an interface (step 682 ). Next, it obtains a list of interfaces inherited by the interface (step 684 ) and sets the current interface to the first interface in the list (step 686 ). Next, the process of 8 H- 2 initializes the results set to an empty set (step 688 ). From step 688 , the process of FIG. 8H-2 iteratively adds interfaces to a result set. This is done by first checking whether the current interface is null, indicating that no other interfaces need to be processed (step 690 ). If not, the process obtains a set of superinterface of the current interface (step 692 ). Step 692 invokes the process 526 , recursively.
[0108] Upon completing step 692 , the process of FIG. 8H-2 adds the set of superinterfaces to a result set (step 694 ) and the current interface to the result set (step 696 ). The process then sets the current interface to the next interface (step 698 ) and loops back to step 690 to continue processing all interfaces. From step 690 , in the event that the current interface is null, the process of FIG. 8H-2 exits by returning the result set.
[0109] An interface table contains an entry for each interface directly implemented by a class, and for all superinterfaces of the directly implemented interfaces. Each entry in the interface table contains an identification of the interface and an interface method table. The table maps interface method declarations to implementations in the class.
[0110] FIGS. 8I-1 and 8 I- 2 show a process 700 for constructing an interface table of a class. Particularly, a FIG. 8I-2 shows in more detail steps 708 of FIG. 8I-1 .
[0111] Referring now to FIG. 8I-1 , a process 700 for constructing interface tables is shown. First, the process 700 obtains a list of interfaces, including superinterfaces, (see process 526 ) that are implemented by the current class (step 702 ). Next, the process 700 sets the current interface to the first interface in this set (step 704 ). The process 700 then checks whether the current interface is null, indicating that it is finished (step 706 ). If not, the process 700 proceeds to construct an interface method table for the current interface for the class (step 708 ), as shown in more detail in FIG. 8I-2 . Next, the process 700 sets a current interface to the next interface (step 710 ) before it loops back to step 706 .
[0112] From step 706 , in the event that the current interface is null, the process 700 records the interfaces with their interface method tables in the class component (step 712 ) before exiting.
[0113] Referring now to FIG. 8I-2 , step 708 is shown in more detail. This process first gets the virtual method table for the class (step 722 ) and the interface methods and tokens for the interface, including inherited methods (step 724 ). Next, the process of FIG. 8I-2 initializes an interface method table by ordering the methods by their token value (step 726 ). Next, the process sets the current method to the first method of the interface method table (step 728 ). From step 728 , the process checks whether the current method is null indicating that it is finished (step 730 ). If not, the process of FIG. 8I-2 finds an implementation of the interface method in the virtual method table (step 732 ). Next, the process records a token value of the virtual method in the interface method table at the location of the current method (step 734 ). It then sets the current method to the next method of the current interface (step 736 ) before looping back to step 730 . From step 730 , in the event that the current method is null, the process of FIG. 8I-2 exits.
[0114] The dynamic binding of elements during execution is discussed next in FIGS. 9A-9C which describe resolution of references to dynamic elements. During compilation, conversion and token assignment, references to instance fields, virtual methods and interfaces methods cannot be resolved to a particular implementation, but only to an abstract description of the item.
[0115] In the case of instance fields, tokens are assigned within the scope of the defining class. An instance of the class contains all of the fields defined not only by the class, but also by all of its superclasses. The tokens do not indicate the location of the field within the instance, since they cannot reflect a particular layout of the instance and cannot account for the location of private and package-visible fields defined by the superclass.
[0116] In the case of virtual methods, during compilation and conversion the name and type signature are known, as well as a class within a hierarchy that implements such a method. However, the exact implementation cannot be known until execution, when it is possible to determine the particular class of the instance on which the method is invoked. For example, both a class A and its superclass B implement a method definition M. It cannot be known until execution whether an invocation of the method M on an instance of compile-time type B will result in execution of the implementation of class A or of class B.
[0117] To provide a means for properly dispatching an invocation of a virtual method during execution, virtual method token assignment is scoped within a class hierarchy. That is, a method of a subclass that overrides a method previously introduced in a superclass inheritance chain must have the same token value as the method it overrides. Also, introduced methods (those methods that do not override methods defined in a superclass) must have token values that are unique within the inheritance chain. Virtual method tables are defined for each class to provide a means for mapping a virtual method token to a particular implementation.
[0118] Interface methods are similar to virtual methods in that the particular implementation cannot be known until execution time, but they differ in that interface methods can be inherited from multiple interfaces. Multiple inheritance of interface causes a problem with the way virtual method tokens are assigned. A method in a class which overrides a method introduced in more than one interface cannot necessarily have the same token value as the methods it overrides, as the multiple definitions may all have different values. Therefore each set of methods for a particular interface is assigned token values without regard to the token values of the methods of any other interface.
[0119] Because interfaces do not share token values, additional information is necessary to dispatch an interface method invocation to a particular method implementation. As interface method tokens are unique within the scope of an interface, both the interface method token and the identity of the interface are needed to determine the method implemented by the class of an instance at execution time. An interface table is defined for each class which maps an interface identity to an interface method table. The interface method table maps the interface method tokens for that interface to method implementations in that class.
[0120] FIGS. 9A-9C are flowcharts illustrating processes for resolving tokens during the execution. Referring now to FIG. 9A , a process 580 for resolving instance field references is shown. First, the process 580 obtains an instance containing the field from a run-time stack (step 582 ). Next, the process 580 determines a token associated with the field and maps the token to an index (step 584 ). The mapping of the token to the index may require examining instance field type information. Moreover, the operation may require adjusting the token value by the size of the superclass's instance. Finally, the process 580 finds the representation of the field in the instance using the index (step 586 ) before exiting.
[0121] In FIG. 9B-1 , a process 620 for resolving a reference to public or protected virtual method is shown. First, the process 620 obtains an instance of a class from the runtime stack (step 621 ) and determines the class of the instance (step 622 ). Next, the process 620 accesses the public virtual method table of the class (step 624 ) and obtains a method table entry using the method token as an index (step 626 ). Finally, the process 620 finds and executes the method based on the content of the entry in the virtual method table (step 628 ) and exits.
[0122] Turning now to FIG. 9B-2 , a process 600 for resolving a reference to any virtual method (including package-visible) is shown. First, the process 600 obtains an instance of a class from the runtime stack (step 601 ) and determines the class of the instance (step 602 ). Next, the process 600 determines whether the high bit of the method token is set to one (step 604 ). If not, the process 600 gets a public virtual method table (step 606 ) and uses the method token as an index into the virtual method table (step 608 ). From step 604 , in the event that the high bit of the method token equals one, the process 600 then sets the high bit to zero (step 610 ) and gets the package virtual method table (step 612 ) before proceeding to step 608 . Finally, the process 600 finds and executes the method based on the content of the entry in the virtual method table (step 614 ) and exits.
[0123] FIG. 9B-3 shows an optimized process 670 for resolving a reference to any virtual method, using optimized virtual method tables as described in FIG. 8G-2 . First, the process 670 obtains an instance of a class from the runtime stack (step 671 ) and sets the current class to be the class of the instance (step 672 ). A method table index is initialized to the method token value (step 674 ). The process 670 then determines whether the high bit of the method token equals one (step 676 ). If not, the process 670 sets a base value to the public method table's base of the current class (step 678 ). Next, the method table is set to the public virtual method table of the current class (step 680 ). The process 670 then checks whether the method table index is less than the base value (step 682 ) and if so, sets the current class to be the superclass of the current class (step 684 ). From step 684 , the process 670 loops back to step 676 to continue processing.
[0124] In step 676 , if the high bit equals one, the process 670 sets the high bit of the method table index to zero (step 690 ). It sets the base value to the package method table base of the current class (step 692 ) and sets the method table to the package virtual method table of the current class (step 694 ) before continuing to step 682 .
[0125] From step 682 , if the method table index is greater than the base, the process 670 obtains a method table entry using the method table index plus the base value (step 686 ). The process 670 then finds the method based on the content of the entry in the method table of the current class (step 688 ). Subsequently, the process 670 exits.
[0126] Referring now to FIG. 9C , a process 650 for resolving interface method reference is shown. First, the process 650 obtains an instance of a class from the runtime stack (step 651 ) and sets the current class to the class of the instance (step 652 ). Next, the process 650 searches for the specified interface in the interface table of the current class (step 654 ). The process then determines whether the interface has been found (step 656 ). If not, the process then sets current class to the superclass of the current class (step 660 ) before looping back to step 654 .
[0127] From step 656 , in the event that the specified interface is found, the process 650 obtains the corresponding interface method table in the current class (step 662 ). It then obtains the virtual method token from the entry in the table whose index is equal to the interface method token (step 664 ). The process 650 then obtains the public virtual method table of the class of the instance (step 666 ). The process 650 gets the virtual method location from the entry in the table associated with the virtual method token (step 668 ). The process 650 then locates the method based on the content of the entry in the virtual method table (step 669 ). Once this is done, the process 650 exits.
[0128] Although the invention has been illustrated with respect to a smart card implementation, the invention applies to other devices with a small footprint such as devices that are relatively restricted or limited in memory or in computing power or speed. Such resource constrained devices may include boundary scan devices, field programmable devices, pagers and cellular phones among many others. The invention may prove advantageous when using servlets if there is object sharing between them. Certain desktop systems may also utilize the techniques of the invention.
[0129] The present invention also relates to apparatus for performing these operations. This apparatus may be specially constructed for the required purpose or it may comprise a general purpose computer as selectively activated or reconfigured by a computer program stored in the computer. The procedures presented herein are not inherently related to a particular computer or other apparatus. Various general purpose machines may be used with programs written in accordance with the teachings herein, or it may prove more convenient to construct more specialized apparatus to perform the required method steps. The required structure for a variety of these machines will appear from the description given. Further, it will be appreciated that a virtual machine consistent with the invention can provide functionality beyond that of earlier virtual machines, such as the virtual machines described in the Java™ Virtual Machine Specification.
[0130] While the Java™ programming language and platform are suitable for the invention, any language or platform having certain characteristics would be well suited for implementing the invention. These characteristics include type safety, pointer safety, object-oriented, dynamically linked, and virtual-machine based. Not all of these characteristics need to be present in a particular implementation. In some embodiments, languages or platforms lacking one or more of these characteristics may be utilized. A “virtual machine” could be implemented either in bits (virtual machine) or in silicon (real/physical machines/application specific integrated circuits). Also, although the invention has been illustrated showing object by object security, other approaches, such as class by class security could be utilized.
[0131] The system of the present invention may be implemented in hardware or in computer program. Each such computer program can be stored on a storage medium or device (e.g., CD-ROM, hard disk or magnetic diskette) that is readable by a general or special purpose programmable computer for configuring and operating the computer when the storage medium or device is read by the computer to perform the procedures described. The system also may be implemented as a computer-readable storage medium, configured with a computer program, where the storage medium so configured causes a computer to operate in a specific and predefined manner.
[0132] The program is here, and generally, conceived to be a self-consistent sequence of steps leading to a desired result. These steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It proves convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. It should be noted, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities.
[0133] While the invention has been shown and described with reference to an embodiment thereof, those skilled in the art will understand that the above and other changes in form and detail may be made without departing from the spirit and scope of the following claims.
[0134] Other embodiments are within the scope of the following claims. | A system links architecture neutral code downloaded to a resource constrained computer. The code may be separated into one or more packages having one or more referenceable items. The system maps the one or more referenceable items into corresponding one or more tokens; orders the tokens to correspond to a run-time mode; downloads the packages to the resource constrained computer; and links the packages into an executable code using the ordered tokens. | 6 |
FIELD
[0001] The present disclosure relates to light guide plates, particularly to a mold, a method of manufacturing a glass light guide plate, and the light guide plate manufactured by the mold.
BACKGROUND
[0002] Traditional light guide plate is made of polymethylmethacrylate (PMMA) and other materials. Yellowing and color bias will appear in the light absorption process of PMMA, which affects the energy-saving and durability of the light guide plate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] Implementations of the present technology will now be described, by way of example only, with reference to the attached figures, wherein:
[0004] FIG. 1 is a schematic view of a substrate of a first embodiment of the present disclosure.
[0005] FIG. 2 is a schematic view of a mold that is manufactured from the substrate of FIG. 1 .
[0006] FIG. 3 is a top plan view of a first surface of the mold of FIG. 2 .
[0007] FIG. 4 is a schematic view of a glass substrate placed on the mold in a method of manufacturing a glass light guide plate.
[0008] FIG. 5 is a schematic view of a light guide plate using the manufacturing method of FIG. 4 .
DETAILED DESCRIPTION
[0009] It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features of the present disclosure.
[0010] One definition that applies throughout this disclosure will now be presented.
[0011] The term “comprising,” when utilized, means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in the so-described combination, group, series and the like.
[0012] FIG. 1 and FIG. 2 illustrate a manufacturing method for a mold for manufacturing a light guide plate.
[0013] FIG. 1 illustrates a substrate 10 . In the illustrated embodiment, the substrate 10 is a cubic. The substrate 10 includes a first surface 12 and a second surface 14 . In other embodiments, the substrate 10 can be any other shape, provided that the substrate 10 has two parallel and opposite smooth surfaces.
[0014] The substrate 10 is made of porous heat-resistant material. The porous heat-resistant material is selected from one or several combinations of Hexagonal Boron Nitride (HBN), silica (SiO2) and alumina (Al2O3), and hexagonal carbon (C). The porous heat-resistant material should have high mechanical strength. The density (D) of the porous heat-resistant material range is from about 2.4 grams per cubic centimeter (g/cm3) to about 6.4 grams per cubic centimeter (g/cm3). The porous heat-resistant material should withstand temperatures of between about 500° C. and about 1500° C. The porous heat-resistant material should maintain its shape at these temperatures for a long time. Holes 16 are formed in the porous heat-resistant material, the holes 16 are distributed evenly and are interconnected. The size of aperture (d) of the holes 16 is from about 0.1 nanometers (nm) to about 2.1 microns (μm). Thus, the whole substrate 10 is permeable to air.
[0015] FIG. 2 illustrates a mold 20 . The mold 20 is manufactured using the substrate 10 .
[0016] In detail, the substrate 10 is processed. Light guide spots 22 are formed in the first surface 12 . FIG. 3 illustrates that the light guide spots 22 are distributed on the first surface 12 . A surface processing method can be any of mechanical drilling, laser drilling, chemical etching, physical vapor deposition (PVD), and chemical vapor deposition (CVD).
[0017] Each light guide spot 22 has a same shape and size. In the illustrated embodiment, the plurality of light guide spots 22 is spread on the first surface 12 according to the desired optical design. The light guide spots 22 are substantially hemispherical recesses. Each of the plurality of light guide spots 22 have a diameter ranging from 30 microns to 400 microns in a direction parallel to first surface 12 . The plurality of light guide spots 22 have a depth ranging from 30 microns to 400 microns in a direction perpendicular to the first surface 12 .
[0018] Due to a roughness requirement of the light guide plate surface, the mold 20 is polished to obtain a smooth first surface 12 (molding surface) after the formation of light guide spots 22 .
[0019] FIG. 4 illustrates the mold 20 and a glass substrate 30 . The glass substrate 30 is cubic. The shape and size of glass substrate 30 are substantially equal to those of the mold 20 . However, the glass substrate 30 can have any thickness. In the illustrated embodiment, the thickness of the glass substrate 30 is far smaller than the thickness of the mold 20 . The glass substrate 30 includes an upper surface 32 and a lower surface 34 . The upper surface of 32 and the lower surface 34 are on opposite sides of the glass substrate 30 .
[0020] The glass substrate 30 is manufactured into a light guide plate 100 by the following steps. The mold 20 is heated to the glass transition temperature Tg of the glass substrate 30 (temperature of transforming polymer from high elastic state into glass state). The glass transition temperature Tg of the glass substrate 30 is less than about 1500° C. The mold 20 is kept at this temperature, and the lower surface 34 of the glass substrate 30 is placed on the first surface 12 . During the molding operation, air is exhausted from the mold 20 to generate suction (negative pressure) and the glass substrate 30 is absorbed onto the first surface 12 . The glass substrate 30 is softened by heat conduction, the softened glass filling the plurality of light guide spots 22 on the first surface 12 . Heating is removed from the mold 20 , the temperature of the mold 20 is reduced below the glass transition temperature Tg and gradually cooled to room temperature. The mold 20 is removed, and the glass light guide plate 100 is thereby obtained.
[0021] FIG. 5 illustrates the glass light guide plate 100 . The glass light guide plate 100 includes an upper surface 32 and a lower surface 34 . The upper surface 32 and the lower surface 34 are located at the opposite sides of the glass light guide plate 100 . A plurality of protrusions 340 are formed on the lower surface 34 . The plurality of protrusions 340 are spread on the lower surface according to the desired optical design. The number and positions of the plurality of protrusions 340 correspond to the number and positions of the light guide spots 22 . Each of the plurality of protrusions 340 is substantially the same size and shape. The protrusions 340 are arc-shaped protrusions. The plurality of protrusions 340 have a diameter range from 30 microns to 400 microns in a direction parallel to the lower surface 34 . The depth of the protrusions 340 ranges from 30 microns to 400 microns in a direction perpendicular to the lower surface 34 .
[0022] The mold 20 is made of a porous heat-resistant material, the porosity contributing to the generation of suction during molding of the plate 100 (air is removed through the pores), thereby the softened glass material molding is absorbed on the forming surface after heating to the glass transition temperature.
[0023] The glass light guide plate 100 can be polished to form a smooth surface depending on the circumstances after molding.
[0024] The plurality of light guides 22 can be selected from different desired optical designs based on different refractive indexes of the glass substrate 30 .
[0025] The glass substrate 30 can be post-processed by physical vapor deposition for example, or chemical vapor deposition, or surface treatment.
[0026] The manufacturing method of the glass light guide plate of the present disclosure provides a glass molding technology, microstructures of light guide plate being directly formed on the glass surface. The glass light guide plate 100 has a better light guide plate penetration than traditional PMMA, and is more durable and energy-efficient. Yellowing and color biasing in the glass production process of the light guide plate are much reduced.
[0027] The embodiments shown and described above are only examples. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the detail, including in matters of shape, size, and arrangement of the parts within the principles of the present disclosure, up to and including the full extent established by the broad general meaning of the terms used in the claims. | A mold which is made of a porous heat-resistant material comprises a first surface and a second surface opposite to the first surface. A plurality of light guide spots are formed on the first surface. The light guide spots are light guide spots. The first surface is a smooth polished surface, the mold enables direct manufacture of light guide plates for less heat expended. | 2 |
CROSS REFERENCE TO RELATED APPLICATION
The invention of this application is disclosed in prior co-pending International Application No. PCT/AU80/00023, filed June 18, 1980, the benefit of which is claimed.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to locks and particularly to locks adapted for a wide variety of applications providing domestic door locks, high level security locks with or without cooperating timing devices, motor vehicles ignition locks and the like.
2. Description of the Prior Art
The state of the locksmiths art has reached a very high level of expertise, particularly in relation to mechanically operated locks. Recent developments in key copying machines have however considerably reduced the security of these locks, in view of the ease with which key copies, including master keys, may be made and the difficulty for the lock concerned to be altered to reject a key that has been duplicated without authority.
BRIEF SUMMARY OF THE INVENTION
Our invention overcomes this difficulty and has been developed without reference to locks of the prior art. Accordingly many features of our lock are entirely novel. Whilst a preferred embodiment of the lock will be described herein with reference to a domestic door lock, in its broadest form our invention comprises a lock including a locking member, said locking member being movable between a disengaged and an engaged position, said lock including movable push rod actuating means and substantially immovable wards, said movable means being operable to cause said locking member to move between said disengaged and engaged positions, a key means interengageable with said wards and said movable push rod means, said key operative to actuate said push rod means and thereby said locking member.
According to a further aspect of the invention the said locking member is biassed towards the said disengaged position.
According to a still further aspect of the invention there is provided a lock having movable push rods and substantially immovable rod-like wards arranged in a generally parallel and preferably coaxial relationship; means for accomodating a key including a token at a position adjacent one end of the rod-like element; and means for moving the thus accommodated token over the substantially immovable rod-like wards and against the movable push rods, thereby to move the push rods.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the invention will now be described with reference to the accompanying drawings wherein:
FIG. 1 is a cross-sectional view showing the lock of this invention in a locked (unengaged) configuration with the cylinders equidistant within the casings, rather than eccentric and the handle withdrawn;
FIG. 2 is a cross-sectional view similar to FIG. 1 showing the lock in an unlocked (engaged) configuration;
FIG. 3 is an exploded view of the lock of FIG. 1;
FIG. 4 is an end view taken on the line IV--IV of FIG. 3;
FIG. 5 is an end view taken on the line V--V of FIG. 3;
FIG. 6 is a cross-sectional view of the key;
FIG. 7 is an elevational view of the key;
FIG. 8 is an inverted elevational view of the handle with the key in position;
FIG. 9 is a perspective view of the adjustment tool; and
FIG. 10 is a cross-sectional view taken on the line X--X of FIG. 1.
DESCRIPTION OF PREFERRED EMBODIMENT
Referring to FIG. 1 and FIG. 3, there is provided a handle 10 having a cylindrical neck 11 adapted to be axially movable into and away from a collar 12 of a door rose 13. In use, the rose 13 is positioned within a suitable circular recess in a door (not shown) such that the shoulder 14 of the rose bears against the face of the door. FIGS. 1 and 2 clearly illustrate this, and emphasize a major advantage of this invention in that the lock mechanism is substantially within the door and not merely within the handle as is the case with the prior art. This of course adds to the security of the lock.
The rose 13 is secured to the door by means of bolts (not shown) passing through the door from the other side and engaging the rose in threaded recesses, one of which is shown at 60.
The collar 12 is provided with an internal flange 15 which comprises the upper limiting means for a main compression spring 16, the other end of which bears against a flange 17 of the lock casing 18. The lock casing is secured to the handle 10 by three bolts 19 and is biassed away from same by said spring 16.
The outer casing 18 is axially movable within said rose 13, and is constrained by a first circlip 20 engaged in an annular groove 21 in the lock casing best shown in FIG. 1 or 2.
The lock mechanism compising the crux of this invention is housed within the casing 18 and is prevented from rotating therein by three rods 22 secured in an inner collar 23. The rods 22 allow axial movement of the lock mechanism by sliding within bores 57 provided in the casing 18 best shown in FIG. 1 or 2.
The inner collar 23 is secured within the collar 12 by a second circlip 24 engaged in a second annular groove 25 in the outer collar 12. Within the inner collar 23 is provided the lock cylinder 26, which is provided with a number of fixed rods 29 coaxial with the lock assembly. The lock cylinder is secured against rotation or axial movement within the inner collar by a set screw 27 which is tightened against a shoulder 28 of the cylinder. Hence the cylinder and inner collar 23 may rotate within the outer collar 12 but are restrained axially. The fixed rods 29 are preferably of equal length, and protrude to a level just inside the rim of the outer collar 12. These fixed rods act as wards and may vary in diameter, shape, number and location in the lock cylinder 26.
The inner collar/cylinder, outer casing and outer collar deliberately make a loose fit one within the other, although the components within cylinder 26 are fitted with decreased tolerances. The reason for the variation in tolerances will be explained more fully below.
An inner cylinder 30 having any desired combination of fixed rods 31 as wards and sliding rods 32 as push rods protruding therefrom is provided eccentrically within the upper portion of said outer cylinder 26, such that the said rods also protrude into the neck of the rose collar to a distance approximately the same as the wards 29 but eccentrically with respect to same. The push rods 32 are located within bores 33 and their upper ends are provided with shoulders 34. Removal of the push rods is also prevented by deformities in the lower ends of the rods as shown in FIG. 1 or 2. The locking member is provided within said inner cylinder 30, and in this embodiment comprises a bushing 36 loosely mounted on a rod 37.
Within the lower portion lock cylinder 26 is located an eccentrically bored clutching sleeve 38 having a shoulder 39 on the lower side thereof and castellations 40 on the upper face thereof. The sleeve is affixed to the inner cylinder 30 by any suitable means, such as silver solder or threaded engagement. It is obviously important that the sleeve be rotated with respect to the inner cylinder before it is affixed to same, in order that the same degree of eccentricity is achieved. This is desirable to ensure that the axis of the locking member is parallel to the axis of the lock. An internal flange 41 is provided on the inner sides of the sleeve 38, as seen in FIGS. 1 and 2. Said sleeve is secured against rotation or axial movement within the lock cylinder 26 by any suitable means such as a cup head bolt 42.
Within the sleeve is provided a connecting member 43 which is biassed over rod 37 toward locking member 36 by a compression spring 44 which in turn is restrained by a bar 45 through a hole near the inner end of the connecting member 43 and the flange 41.
The inner end of the connecting member is bored out at 59 to accomodate rod 37. The operative end of the connecting member 43 is shaped into a square rod at 47 to engage a square hole 58 in any known latch withdrawal mechanism shown generally at 48 in FIGS. 1 and 2. The hold in this sleeve 38 through which the locking member passes is eccentric in relation to the cylinder 26 by approximately 0.05 inches.
The key as shown in FIGS. 6 and 7 comprises a flat frame 49 to which is attached a handle 50. The frame is made unidirectional by a tongue 51, and is provided with two rotatable tokens 52, 53 one within the other.
The placement of this inner token 53 is eccentric within the outer token 52 thereby providing a greater number of combinations and thus greater security. Each token is provided with holes 56, which may be varied in number size and location from key to key to suit the variations on the cylinders. In an unillustrated variation the key may be more acceptable to the consumer by the provision of a handle that folds into the same plane as the frame.
The inner face of the neck 11 of the handle 10 is provided with a shallow recess 54 for receiving the key when inserted into the handle in a radial direction. Further, the side of the neck 11 is recessed at 55 to accomodate the key handle 50 on release of the door handle 10 and axial movement of the key within the collar 12. This will now be fully described.
The following relates to the installation of the lock in an exterior door handle, and in most cases is matched with a normal direct acting handle on the inside of the door.
Normally, the handle will inoperatively turn without resistance, the connecting member being withdrawn within the cylinder by spring 44. Hence the handle is not linked to the known latch mechanism, and the door is "locked". The lock of our invention is in "neutral", or disengaged.
The handle is biassed towards the door by spring 16, but may be axially withdrawn so that a key may be radially inserted into recess 54 on the inner face of the handle neck 11. The key must be fully inserted to allow the legs of the handle to fit into recess 55.
Once the key is in position in the handle, the handle may be released, causing the key to be axially carried onto the rods 29, 31 and 32. The key is held by the base of the neck 11 on one side, recesses 54 and 55, and the upper end of the casing 18 on the other side. Thus such handle, outer casing and key axially and rotationally move together in relation to the collar 12.
The inward movement of the key and handle will continue only if the holes in the tokens match the rods with regard to number, spacing, size and shape. If the key does not fit, the handle will turn inoperatively. Rotation of the handle and key may be necessary befoe the key will come to the correct position and the rods penetrate the tokens. On further inward movement of the handle certain holes 56 of the key slide along the respective aligned wards, but the key at other holes depresses the two movable rods by bearing down on their shoulders 34. The push rods 32, which are diametrically opposed, slide the locking member 36 along rod 37 into engagement with connecting member 43. The connecting member thereby is pushed out of sleeve 38 against the bias of spring 44. At this stage rotation of the handle will not open the door, although the key is engaged with and may turn the cylinder.
Further release of the handle results in the bar 45 entering one of the slots formed by the castellation 40 of the connecting member and the entry of the operative end of the connecting member into the co-operative recess 58 in a known latch withdrawal mechanism. Obviously the configuration of the operative end 47 may be adapted to cooperate with the latch mechanism that is desired.
Once the handle is fully released rotation will cause the sleeve, and thus the bar and the connecting member to turn. Hence the door will open.
It is obviously essential that cup head bolt 42 be tight, ensuring no slippage between the sleeve and the cylinder. Other methods of securing these components form part of the invention, as does equivalent methods of securing the cylinder to the collar 23 other than by the set screw 27.
In the preferred form shown, two movable rods 32 are used. This provides protection against the unauthorized depression of one rod 31, as the bushing, which is a loose fit on rod 37, would then become misaligned due to the uneven pressure and lock on rod 37. Friction means such as the provision of thread on rod 37 may be used to enhance such locking action. The immobilization of the bushing thus prevents movement of the connecting member.
A major advantage of our invention is found in the ability to reset the tokens within the key. Either one or both tokens may be reset. Should it be desired to rotate the inner token in relation to the outer token and the key frame, the key is inserted in the door in the normal way. The inner handle assembly (which is not subject to security measures) and the outer handle assembly are removed, exposing the inner face of the lock assembly. The cup head bolt 42 is loosened, and an adjustment tool (FIG. 9) is fitted to the holes 61 in the sleeve and the whole rotated as desired. See FIGS. 4 and 5. This action causes the pins 31, 32 to rotate with respect to pins 29, and hence the inner token relative to the outer in the key. The bolt 42 is then re-tightened.
To alter the outer token in relation to the key frame, the set screw 27 is loosened, and the tool applied to holes 62 in the outer cylinder 26. Rotation of the outer cylinder within the casing 18, which holds the key via the handle recess, achieves the desired result.
Hence a large number of positions may be achieved for one key/lock combination. Variations in the size, shape and position of the holes/rods provides an almost infinite number of combinations.
The ability to easily re-set the lock and its key is seen as one of the most important advantages of the invention. No master key system is thought to be applicable, thus further increasing security.
If desired, a second lock may be fitted to the inner handle, in which case the inner collar (not shown) of the rose of the second lock would be lengthened and expanded to project further through the door to engage and slide over the collar 63 of the first rose. In this case transverse holes are provided through the overlapping collars and long expanding bolts of the Luxon type used from the edge of the door to lock the two collars, and hence the two lock assemblies, together.
Where only the outer handle is fitted with a lock, the inner handle may be provided with a snib to prevent the locking member engaging. Thus even possession of a correct key would not guarantee entry if the inner handle were snibbed.
INDUSTRIAL APPLICABILITY
Whilst our invention has been described in relation to a domestic door lock as represented in the drawings, it is to be appreciated the lock mechanism may take on many forms bearing little physical resemblance to the door lock shown in the drawings. The invention has application ranging from simple domestic systems to the highest level of security control, for example in bank vault mechanisms and defense establishment uses.
Naturally, the higher the level of security required, increasing use may be made of preferred design features such as multiple cylinders, eccentricity of cylinders and tokens, multiple tokens, and the use of sophisticated means equivalent to the connecting member. | A key operated lock having a handle member slidably and rotatably operating within a rose member secured in a door, the rose having a bore therethrough in which a lock cylinder is rotatably mounted but restrained against axial displacement and has an axially displaceable and rotatably mounted latch actuator operably engageable with the handle by a key insertable into the handle transversely to the rotational axis. The lock cylinder has fixed wards extending toward the handle and key member which in the proper position of the key are in alignment with holes in the key which permit interlocking of the handle via the key with the lock cylinder for simultaneous rotation. Push rods are axially movable in the lock cylinder and are displaced by the key through axial movement of the handle to displace the latch actuator into coupling engagement with the lock cylinder for rotation therewith and engagement with the latch release device for the door, so that rotation of the handle via the key will thereby release the latch. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of U.S. Ser. No. 14/217,390 filed Mar. 17, 2014, which in turn claims the benefit under 35 USC 119(e) of U.S. provisional 61/801,509, filed Mar. 15, 2013, the contents and teachings of each which are incorporated herein by reference in entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention pertains generally to electrical communications, and more particularly to condition responsive indicating systems with radio link and including personal portable device for tracking location. The condition responsive indicating systems of the present invention monitor the specific condition of humans or animals. In one preferred manifestation, a fully self-contained collar designed in accord with the teachings of the present invention monitors the location of a pet such as a dog, and provides well-defined and primarily positive stimulus to train the pet to stay within a predetermined area.
[0004] 2. Description of the Related Art
[0005] Dogs are well-known as “man's best friend” owing to the many beneficial services that they provide. However, and likely since mankind first befriended dogs, there has existed a need to control the territory that a dog has access to. There are many reasons that motivate this need, many which may be relatively unique to a particular dog or owner and others that are far more universal.
[0006] Irrespective of the reason, there have been limited ways to exert this control over a dog. One method is a fixed containment structure such as a fence or building. As may be apparent, such structures are typically expensive and time consuming to install, and necessarily static in location. In other words, they are only useful at the location where they are constructed, and so are of no value when a pet and owner travel. Furthermore, these static structures often interfere in other ways with other activities of the dog owner, such as with lawn care or interfering with the owner's movement about a property. In addition, the dog may find ways to bypass the structure, such as by digging under a fence or slipping through a not-quite completely secured gate.
[0007] A second approach to controlling accessible territory is through a combination collar and leash or similar restraint. The leash is anchored to a fixed point, or in the best of situations, to a line or cable along which the dog can travel. Unfortunately, most dogs are notoriously bad at untangling or unwrapping a leash from a fixed object. Consequently, dogs tend to tangle the leash about trees, posts and other objects, and can become completely unable to move. If the owner is not aware that the dog has become tangled, this can lead to dangerous situations in cases such as extreme weather or when the dog has been left unattended for an extended period.
[0008] Additionally, some dogs are very good at escaping the leash, such as by backing away from the leash and using the leash force to slip off the collar, or by chewing through the leash. Once again, if the owner is unaware, the dog may travel from the desired area into other unsuitable areas such as roadways and the like. This may put both dog and humans in jeopardy, such as when a vehicle swerves to avoid the dog or when a dog has a temperament not suited to the general human population.
[0009] The leash also necessarily defines the region in which the dog may travel. For exemplary purposes, with a ground stake and a leash the dog is constrained to a circle. In this example, the owner will typically define the circle to the smallest radius that the dog may desirably travel within. As can be understood, for all but circularly limited areas, this leads to a great deal of space that the dog cannot access, but which would otherwise be suitable for the dog.
[0010] In consideration of the limitations of static structures and leashes, various artisans have proposed vary beneficial further techniques that provide more flexibility and capability, such as buried or above ground transmitter antennas and radio collars that either detect the crossing of a buried line or detect the reception or absence of reception of a signal broadcast by the transmitter antenna. These systems remove the physical link between dog and a static structure, meaning the dog will not get tangled in obstacles when moving about. Further, in the case of a buried line, the line may follow any geometry of land, and so is not limited to a circular pattern limited by a particular radius.
[0011] Unfortunately, burying a line can be difficult or impossible if there are other objects, such as irrigation systems, buried utility lines, landscaping, hard surfaces, trees, or other fixed objects. Additionally, current soil conditions such as frozen soil or snow covered ground in the winter may also limit the ability to bury the line. Radio systems are also well known to be significantly affected by static and other forms of Electro-Magnetic Interference or Radio-Frequency Interference (EMI-RFI). Consequently, a dog may be shocked or otherwise punished without basis or appropriate reason. As is known in the field of psychology, this random punishment can literally destroy the training of a dog, and may lead to erratic or wanton misbehavior. This problem is also very location dependent, meaning that there are places where there is so much EMI-RFI that a radio system is completely unusable. As a result of the inability to completely eliminate or substantially eradicate the effects of EMI-RFI, the use of these radio systems is far from universal. Instead, many dog owners continue to rely upon static structures or leashes to control the territory accessible by their dog.
[0012] With the advent and substantial advancement of Global Positioning Systems (GPS), presently primarily used for navigation, artisans have recognized the opportunity to incorporate GPS technology into pet containment. Several systems have been proposed in the literature for decades, but these systems have not as yet become commercially viable.
[0013] One significant limitation of prior art GPS systems is the accuracy of the system. Accuracy can be dependent upon variables such as atmospheric variations, signal reflections and signal loss due to obstacles, and variability intentionally introduced into the system. Similar variability is found in various radio and cellular locating systems.
[0014] A GPS or similar navigation system that is accurate to plus or minus ten meters is very adequate for navigational purposes, for example to guide a person to a commercial building for a meeting or for other commerce. However, for pet containment this level of accuracy is completely unacceptable. For exemplary purposes, many residential yards are forty feet wide, or approximately 10 meters. A system that is only accurate to plus or minus ten meters might try to locate the dog in either neighbor's yard, depending upon the system on any given day.
[0015] Another limitation is the amount of calculation required to determine whether the pet is within a selected area of containment. Prior art GPS systems use nodes to define the perimeter, and then mathematically calculate where the pet is relative to the nodes. Unfortunately, this requires a substantial amount of computation, which increases greatly as the number of nodes are increased. As a result, these systems commonly rely upon a primary processing system that is remote from the dog, to which the dog's collar is coupled via radio waves or the like. This permits the primary processing system to perform calculations and then relay results or control signals back to the collar. Undesirably, this also adds complexity, drains precious battery power limiting the usable collar time, and again makes the containment system dependent upon conventional radio communications systems. In addition, the need for both the collar and a secondary base station makes the system far less portable. This means, for example, that taking the dog from home to a park is impractical.
[0016] A further limitation of the prior art is battery life. A collar that must be removed and recharged every few hours is unacceptable for most purposes. Unfortunately, the intensive computations required by prior art systems either requires a fast and consequently higher power processor unit, or a communications link such as a radio link to a base station. While the collar unit may transmit data back to the base unit to avoid the need for complex computational ability, even the transmission of position information and reception of collar actions requires a reasonably powered radio. It will be apparent that walkie-talkies, cell phones and other hand-held radio devices all have very large batteries to provide adequate transmission and reception life, and yet these devices often only support several hours of communications. As can be appreciated, size and weight are severely restricted for a device fully self-contained on a dog's collar, and the inclusion of a large battery is undesirable.
[0017] The following patents and published patent applications are believed to be exemplary of the most relevant prior art, and the teachings and contents of each are incorporated herein by reference: U.S. Pat. No. 4,393,448 by Dunn et al, entitled “Navigational plotting system”; U.S. Pat. No. 4,590,569 by Rogoff et al, entitled “Navigation system including an integrated electronic chart display”; U.S. Pat. No. 4,611,209 by Lemelson et al, entitled “Navigation warning system and method”; U.S. Pat. No. 4,817,000 by Eberhardt, entitled “Automatic guided vehicle system”; U.S. Pat. No. 4,999,782 by BeVan, entitled “Fixed curved path waypoint transition for aircraft”; U.S. Pat. No. 5,067,441 by Weinstein, entitled “Electronic assembly for restricting animals to defined areas”; U.S. Pat. No. 5,191,341 by Gouard et al, entitled “System for sea navigation or traffic control/assistance”; U.S. Pat. No. 5,351,653 by Marischen et al, entitled “Animal training method using positive and negative audio stimuli”; U.S. Pat. No. 5,353,744 by Custer, entitled “Animal control apparatus”; U.S. Pat. No. 5,355,511 by Hatano et al, entitled “Position monitoring for communicable and uncommunicable mobile stations”; U.S. Pat. No. 5,381,129 by Boardman, entitled “Wireless pet containment system”; U.S. Pat. No. 5,389,934 by Kass, entitled “Portable locating system”; U.S. Pat. No. 5,408,956 by Quigley, entitled “Method and apparatus for controlling animals with electronic fencing”; U.S. Pat. No. 5,450,329 by Tanner, entitled “Vehicle location method and system”; U.S. Pat. No. 5,568,119 by Schipper et al, entitled “Arrestee monitoring with variable site boundaries”; U.S. Pat. No. 5,587,904 by Ben-Yair et al, entitled “Air combat monitoring system and methods and apparatus useful therefor”; U.S. Pat. No. 5,594,425 by Ladner et al, entitled “Locator device”; U.S. Pat. No. 5,751,612 by Donovan et al, entitled “System and method for accurate and efficient geodetic database retrieval”; U.S. Pat. No. 5,791,294 by Manning, entitled “Position and physiological data monitoring and control system for animal herding”; U.S. Pat. No. 5,857,433 by Files, entitled “Animal training and tracking device having global positioning satellite unit”; U.S. Pat. No. 5,868,100 by Marsh, entitled “Fenceless animal control system using GPS location information”; U.S. Pat. No. 5,911,199 by Farkas et al, entitled “Pressure sensitive animal training device”; U.S. Pat. No. 5,949,350 by Girard et al, entitled “Location method and apparatus”; U.S. Pat. No. 6,043,748 by Touchton et al, entitled “Satellite relay collar and programmable electronic boundary system for the containment of animals”; U.S. Pat. No. 6,114,957 by Westrick et al, entitled “Pet locator system”; U.S. Pat. No. 6,172,640 by Durst et al, entitled “Pet locator”; U.S. Pat. No. 6,232,880 by Anderson et al, entitled “Animal control system using global positioning and instrumental animal conditioning”; U.S. Pat. No. 6,232,916 by Grillo et al, entitled “GPS restraint system and method for confining a subject within a defined area”; U.S. Pat. No. 6,236,358 by Durst et al, entitled “Mobile object locator”; U.S. Pat. No. 6,263,836 by Hollis, entitled “Dog behavior monitoring and training apparatus”; U.S. Pat. No. 6,271,757 by Touchton et al, entitled “Satellite animal containment system with programmable Boundaries”; U.S. Pat. No. 6,313,791 by Klanke, entitled “Automotive GPS control system”; U.S. Pat. No. 6,421,001 by Durst et al, entitled “Object locator”; U.S. Pat. No. 6,441,778 by Durst et al, entitled “Pet locator”; U.S. Pat. No. 6,480,147 by Durst et al, entitled “Portable position determining device”; U.S. Pat. No. 6,487,992 by Hollis, entitled “Dog behavior monitoring and training apparatus”; U.S. Pat. No. 6,518,919 by Durst et al, entitled “Mobile object locator”; U.S. Pat. No. 6,561,137 by Oakman, entitled “Portable electronic multi-sensory animal containment and tracking device”; U.S. Pat. No. 6,581,546 by Dalland et al, entitled “Animal containment system having a dynamically changing perimeter”; U.S. Pat. No. 6,700,492 by Touchton et al, entitled “Satellite animal containment system with programmable boundaries”; U.S. Pat. No. 6,748,902 by Boesch et al, entitled “System and method for training of animals”; U.S. Pat. No. 6,903,682 by Maddox, entitled “DGPS animal containment system”; U.S. Pat. No. 6,923,146 by Kobitz et al, entitled “Method and apparatus for training and for constraining a subject to a specific area”; U.S. Pat. No. 7,034,695 by Troxler, entitled “Large area position/proximity correction device with alarms using (D)GPS technology”; U.S. Pat. No. 7,259,718 by Patterson et al, entitled “Apparatus and method for keeping pets in a defined boundary having exclusion areas”; U.S. Pat. No. 7,328,671 by Kates, entitled “System and method for computer-controlled animal toy”; U.S. Pat. No. 7,677,204 by James, entitled “Dog training device”; U.S. Pat. No. 8,155,871 by Lohi et al, entitled “Method, device, device arrangement and computer program for tracking a moving object”; 2007/0204804 by Swanson et al, entitled “GPS pet containment system and method”; and 2008/0252527 by Garcia, entitled “Method and apparatus for acquiring local position and overlaying information”; and EP0699330 and WO 94/27268 by Taylor, entitled “GPS Explorer”.
[0018] In addition to the foregoing, Webster's New Universal Unabridged Dictionary, Second Edition copyright 1983, is incorporated herein by reference in entirety for the definitions of words and terms used herein.
SUMMARY OF THE INVENTION
[0019] In a first manifestation, the invention is a wireless location assisted zone guidance system adapted to assist in the training and management of an animal. The system includes a collar, a wireless location determination apparatus, at least one animal stimulation apparatus carried by the collar, a processor coupled to the wireless location determination apparatus and operative to receive latitude and longitude information therefrom, memory accessible by the processor, a human interface, and a plurality of guidance zones defined using the latitude and longitude information. Each one of the plurality of guidance zones has an associated unique set of characteristics used by the processor to provide behavioral guidance stimulation to the animal through the animal stimulation apparatus. The improvement comprises a data table stored in the memory as a two-dimensional array having an ordinate and abscissa, a first one of the ordinate and abscissa corresponding to longitude and a second one of the ordinate and abscissa corresponding to latitude, with each value stored in the data table identifying a one of the plurality of guidance zones.
[0020] In a second manifestation, the invention is a method of storing behavioral guidance zone indicia in a double-indexed array having a pair of indices in electronically accessible memory and electronically retrieving behavioral modification actions associated with a current geographic location. In accord with the method, a first one of the double-indexed array indices is electronically associated to a latitudinal offset from a geographic reference point. A second one of the indices is electronically associated to a longitudinal offset from the geographic reference point. A value is stored at each individual array location representing a single behavioral guidance zone selected from a plurality of distinct behavioral guidance zones. A unique set of behavioral processes associated with each one of the plurality of distinct behavioral guidance zones is stored in electronically accessible memory. The current geographic location is represented by latitude and longitude points. A latitudinal offset and a longitudinal offset between the current geographic location and the geographic reference point are electronically determined. The stored value representing the single behavioral guidance zone is electronically retrieved from an individual array location defined by the latitudinal offset and the longitudinal offset. The unique set of behavioral processes associated with the stored value is electronically retrieved.
[0021] In a third manifestation, the invention is a wireless location assisted zone guidance system adapted to assist in the training and management of an animal. The system comprises a wireless location determination apparatus; and at least one animal stimulation apparatus. A processor is coupled to the wireless location determination apparatus and operative to receive latitude and longitude information therefrom and coupled to the at least one animal stimulation apparatus and adapted to operatively control a generation of stimulation. Memory is coupled with and accessible by the processor. A human interface is adapted to operatively enable selective control over the processor. A data table is stored in the memory as a two-dimensional array having a first index adapted to operatively represent an ordinate and having a second index adapted to operatively represent an abscissa. A plurality of geographically defined guidance zones are operatively stored in the data table, a first one of the ordinate and abscissa corresponding to longitude and a second one of the ordinate and abscissa corresponding to latitude, respectively, with each value stored in the data table identifying a one of the plurality of geographically defined guidance zones. The processor is adapted to operatively receive latitude and longitude information from the wireless location determination apparatus, retrieve a value stored in a location in the data table using the longitude information as the first array index and latitude information as the second array index, and use the retrieved value to determine a one of the plurality of guidance zones that the latitude and longitude information from the wireless location determination apparatus is associated with, and provide behavioral guidance stimulation to the animal through the animal stimulation apparatus responsive thereto.
OBJECTS OF THE INVENTION
[0022] Exemplary embodiments of the present invention solve inadequacies of the prior art by providing a look-up table. In a most preferred embodiment of the invention, the table is defined by rows and columns that are mapped to ordinate and abscissa data points representing predefined geographic locations. Each data point offset in the table corresponds to a predefined geographic offset. Each data point in the table stores a value indicative of a particular one of several guidance zones. Each guidance zone has an associated set of characteristics used to provide behavioral guidance to an animal. The determination of the guidance zone is made by determination of the present location using GPS or equivalent signals. Identification of the corresponding table location is made by calculating the latitudinal and longitudinal offsets from a reference point, and using these offsets as the two indices for a double-indexed array. The value retrieved from the double-indexed array identifies the guidance zone. Based upon either or both of collar location history and the desirability value returned from the table, a variety of actions may be triggered within the collar, such as providing appropriate positive or negative stimulus.
[0023] To further improve the accuracy of determination of present location, a position freshly determined through satellite or radio fixing is compared to one or more recently determined and stored historical positions. Depending upon parameters selected at design time, if an impossible jump in position has occurred, or alternatively if a highly unlikely jump in position has occurred, the freshly determined position may be discarded, and a new position determined again. Consequently, momentary erratic reception which is known to occur in position determination systems will be discarded and will not disrupt the accuracy. This can be vital to the quality of animal behavior training.
[0024] The present invention and the preferred and alternative embodiments have been developed with a number of objectives in mind. While not all of these objectives are found in or required of every embodiment, these objectives nevertheless provide a sense of the general intent and the many possible benefits that are available from ones of the various embodiments of the present invention.
[0025] A first object of the invention is to provide a safe and humane apparatus for modifying the behavior of a pet. From the descriptions provided herein and the teachings incorporated by reference herein above, it will be apparent that the present invention may also be applied in certain instances to humans, livestock or other animals. A second object of the invention is to provide a fully self-contained apparatus that will determine location and provide stimulus based upon that location for extended periods of operation. As a corollary, the fully self-contained apparatus is preferably operational with universally available location systems, including but not limited to satellite GPS, cellular telephone triangulation systems, and radio triangulation system such as Loran, but may alternatively be provided with a custom location system if so desired. By using universally available location systems, there is no limit on the locations where the apparatus may be used. Another object of the present invention is to enable simple and efficient set-up and operation by a person. A further object of the invention is to efficiently and expeditiously train a pet, to significantly reduce training time and increase the effectiveness of the training. As a corollary, embodiments of the present invention will preferably provide the effective animal training while preserving the spirit and positive attitude of the animal. Yet another object of the present invention is to enable a person to set an acceptable area or “safe zone” using only the self-contained apparatus, and to adjust or redefine the area again by simple manipulation of the self-contained apparatus. An additional object of the invention is to enable the self-contained apparatus to automatically generate a number of zones that facilitate positive training and behavior modification, and thereby guide a pet or other living being appropriately.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The foregoing and other objects, advantages, and novel features of the present invention can be understood and appreciated by reference to the following detailed description of the invention, taken in conjunction with the accompanying drawings, in which:
[0027] FIG. 1 illustrates a prior art property such as might be mapped in accord with the teachings of the present invention.
[0028] FIG. 2 illustrates a map of numerical values visually overlaid onto and electronically associated with the property of FIG. 1 , in accord with the teachings of the present invention.
[0029] FIG. 3 illustrates the map of numerical values of FIG. 2 , but absent the property illustrations.
[0030] FIG. 4 illustrates the map of numerical values of FIG. 3 , divided into four distinct tiles and including a latitude and longitude reference point associated with each tile.
[0031] FIG. 5 illustrates the upper left tile or quadrant taken from the map of numerical values of FIG. 4 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0032] In a preferred embodiment designed in accord with the teachings of the present invention, a pet owner might want to train a pet to stay within an example property such as that illustrated in prior art FIG. 1 . An outer limit of the property 2 may encompass one or more buildings 3 , a driveway 4 , and a mailbox 5 . If, for exemplary purposes, the pet is or will be trained to walk with the owner to the mailbox, or to retrieve the newspaper from adjacent to the mailbox, then the owner may wish to provide a small peninsula 6 which could extend beyond the bounds of the particular property location.
[0033] A self-contained collar apparatus, which might for exemplary purposes and not solely limiting thereto resemble that illustrated by Swanson et al in 2007/0204804 and incorporated by reference herein above, will contain the necessary electronic components such as illustrated in the Swanson et al FIG. 5 , including components to receive and decipher location determining signals and also explicitly containing both volatile and non-volatile memory. In the preferred embodiment, the location determining signals are converted to latitude and longitude references, though any suitable coordinate reference representative of a geographic area may be used. Switches and a display will also preferably be provided, again such as illustrated in the Swanson et al published patent application, to allow a person to interact with the collar apparatus. Other requisite components, both as described in Swanson et al and as will be understood from the following description, will also be provided therein.
[0034] To establish a new area, a person will interact with the self-contained collar apparatus switches or other suitable input apparatus to identify that a new area is to be recorded. Next, the person will transport the self-contained collar apparatus around the perimeter of the land area, such as by following outer limit 2 . During this traverse of the outer limit 2 , the self-contained collar apparatus will record discrete location points which have been traversed, and add those to a table stored in a memory within the collar. Once the outer limit 2 has been traversed, the person will again interact with the self-contained collar apparatus to identify that the outer limit has been traversed, or, if so enabled, the collar will automatically detect that an area has been completely circumscribed.
[0035] Next, the micro-controller or other suitable processor will preferably automatically convert this outer limit 2 into a table 10 of values such a illustrated for exemplary purposes in FIG. 2 . While the numerals 0-3 are used therein for the purposes of the present illustration, any suitable designations, whether numeric or not, may be used. As but one example, the numerals 0-3 represent four choices, and so may easily be represented by two bits of data. In such case, the possible combinations are binary 00, 01, 10, and 11. While FIGS. 1 and 2 illustrate an exemplary outline of an area that the pet owner might wish to contain a dog within, which is a subset of the total property, the area can be of any geometry, and in the example is somewhat irregular.
[0036] In the preferred embodiment, a number of different zones are defined based upon the traversal of outer limit 2 during initial setup. The area beyond outer limit 2 is defined by an “out-of-bounds” zone 11 represented by a numerical value of zero at each discrete location. Immediately inside of the zero-value locations is a zone of locations assigned a numerical value of one. This will be referred to herein as the “warning zone” 12 . Between “out-of-bounds” zone 11 and “warning zone” 12 in FIG. 2 , a dashed line 13 has been drawn for illustrative purposes. This line does not actually exist in the stored data table, but instead helps to better illustrate the various zones that are defined by the various location values.
[0037] A plurality of discrete locations relatively inward from the warning zone 12 are assigned a numerical value of two, and represent an “alert zone” 14 . Again, for the purpose of illustration only, a dashed line 15 is shown separating alert zone 14 from warning zone 12 . Again, and like line 13 , this line 15 does not actually exist in the stored data table, and is provided solely for illustrative purposes.
[0038] Finally, an innermost “safe zone” 16 preferably intentionally encompasses the largest area of all zones and is populated with discrete location values assigned to equal the numerical value o f three. Dashed line 17 , like lines 13 and 15 , indicates the separate zones, but does not exist in the stored data table.
[0039] As is evident when comparing FIGS. 1 and 2 , line 13 corresponds approximately to outer limit 2 . Due to the discrete nature of the resolution of the particular position determining system, such as a GPS system, the points defined during the traversal of outer limit 2 may or may not exactly correspond to the land location. In addition, since the outer limit 2 may not be linear, and may instead include a number of irregularities such as peninsula 21 and slightly cropped corners 23 and 26 , the data points more interior but generally adjacent to these irregularities will have variability in their associated geometries relative to that of the outer limit 2 . So, and again for exemplary purposes, peninsula 21 is too narrow to provide for the as-illustrated exemplary two data point width provided for each zone. Nevertheless, there is a single data point of numerical value 2 protruding at reference numeral 22 illustrated in FIG. 3 . Consequently, as outer limit 2 was traversed at set-up, a dog can reach the base of mail box 5 , which is located at this single data point of numerical value 2 at reference numeral 22 , without receiving a warning stimulus. Nevertheless, the dog will still receive an alert stimulus such as a vibration. Similarly, the intricacies of notched corner 26 are lost as the corner becomes a simple square corner at reference numeral 27 of FIG. 3 . Likewise, the elaborate stepping of cropped corner 23 fades some to simpler corner 24 , and becomes a very simple single curve at more interior corner 25 .
[0040] Also strictly for the purpose of illustration, and not limiting the invention solely thereto, two GPS location points are used as the width of each of the alert and warning zones. Consequently, in the embodiment as illustrated, each of these alert and warning zones are calculated to be approximately two GPS points in width. It will be understood herein that the width of the zones may be predetermined to be more or less than the exemplary and illustrated two data points. Furthermore, the number of zones may be varied from the three zones that are illustrated.
[0041] While most of the zone areas are, in fact, two data points wide, the width of the zones at sharp transition points, such as corners, may be greater or less than two data points in width. The particular decisions for how to shape interior zones will be determined by algorithms chosen or written by a designer at design time. Furthermore, there may be times where the assisted guidance zone takes on a very irregular shape, forming a narrow peninsula between two larger safe zones. When there is not sufficient room for the predetermined number of zone location pints, such as within peninsula 21 of FIGS. 1 and 2 , in the preferred embodiment the data point calculations begin with the warning zone value first.
[0042] As maybe apparent, a person may choose where to traverse in order to control the formation of various zones. As another example, a person trying to create a larger buffer adjacent a high traffic road would, when setting up the collar zones, simply walk an outer limit farther from the edge of the road. This maintains more consistent zone widths, which is believed to offer better training for an animal than varying the width of the zones. Nevertheless, and alternatively, it is contemplated herein to allow a person the ability to vary the width of zones to correspond with various objects or hazards such as fences, gardens, and roadways.
[0043] FIG. 3 illustrates the data table representation of the land area of FIG. 1 , but without the land features shown. FIG. 3 simply shows the latitudinal and longitudinal plot of the shape of the assisted guidance zones, as defined by the numerical values stored in the data table. In accord with the present invention, a latitude and longitude land map is converted to and saved as an X-Y plot or table of points, where one axis (in this case the rows) represents latitude and the other axis (in this case as illustrated, the columns) represents longitude. Each point is then assigned a numerical value that is representative of a zone within the assisted guidance area.
[0044] These points may for exemplary purposes and in accord with the preferred embodiment, correspond to specific points of geographic latitude and longitude determined to a particular degree of resolution. The degree of resolution may typically be the limit of precision available for a particular location system, such as six decimals of precision in a GPS system. So, as represented in FIG. 4 , the latitude and longitude representations are presented to six decimal precision, though other suitable levels of precision are considered incorporated herein.
[0045] In this illustration of FIG. 4 , reference point 41 may for example represent a point at 44.925866 degrees latitude, and −92.940617 longitude. Reference point 42 may represent a point at 44.925673 degrees latitude, and −92.940617 longitude. Reference point 43 maybe used to represent a point at 44.925673 degrees latitude, and −92.940160 longitude. Reference point 44 may be used to represent a point at 44.925866 degrees latitude, and −92.940160 longitude. While as illustrated these reference points 41 - 44 are shown slightly offset from and intermediate between the various data points, they may instead be selected to correspond exactly to a particular data point in the table.
[0046] As may be appreciated, for a given degree of latitude and longitude resolution, the larger a tile is, the more memory is required to store the tile. In other words, if the resolution were representative of five foot increments across the surface of the earth, it would only take twenty of these increments to cover a one hundred foot property boundary. For a square property of 100 feet by 100 feet, there would only be a total of 400 data points within the outer boundary. Even with the inclusion of data points outside of the boundary, this zone could easily be mapped with a thousand data point tile.
[0047] In contrast, a large property such as a large ranch, farm, park or the like could, using this same five foot resolution, require more than one million points to map. As may be appreciated, this requires one thousand times the tile size to save the entire map zone within a single tile in memory, or one thousand times the available memory.
[0048] Storage of the data table requires memory, and a suitable electronic system within the collar will not be provided with unlimited memory within which to store data points. In accord with a preferred embodiment of the system, the memory will be divided into some combination of slower non-volatile memory and relatively faster but volatile RAM. The slower, non-volatile memory for exemplary but non-limiting purposes might comprise well-known flash memory. If the device uses higher speed memory such as RAM to reduce operation time, and there are more data points than available space in RAM to store the table, the preferred embodiment processor will analyze the table and set up one or more tiles in RAM to be used during system operation.
[0049] To cover the exemplary property of FIG. 1 , the numerical representation of FIG. 4 incorporates a total of four distinct “tiles” or squares that contain these numerical representations. FIG. 5 provides a zoomed-in view of only one of these four tiles, the top left tile of FIG. 4 . Using this preferred numerical representation substantially reduces the calculations required when compared to the prior art.
[0050] In exemplary operation, the latitude-longitude location of a dog is determined through the GPS system as is known in the field of navigation. This is then used to determine which tile, plurality of tiles, or single numerical representation is required to determine the position of the dog. If the tile containing the particular latitude and longitude is not already loaded into RAM, then it will be loaded. This determination will be easily made by comparing the current latitude and longitude to the reference points such as points 41 - 44 to select the appropriate tile(s). Then, preferably and for exemplary purposes, a simple RAM access may be made, where the RAM memory location is calculated based upon the present latitude and longitude offset from the lower-left latitude and longitude found on the numerical representation tile. This lower-left corner may be understood to be the reference location for the tile, such as reference point 41 in the illustration of FIG. 5 . While any point within a tile may be used as a reference location, the lower-left is illustrated for exemplary purposes.
[0051] The offset determination is a simple subtraction of the reference location, such as reference point 41 of FIG. 5 , from the currently determined location. Then, this difference is used as the table index, to directly address the particular table location. In the preferred embodiment, each data point is stored in memory using a double-indexed array, with each of the two indices of the array uniquely representing one of the latitudinal or longitudinal offset from the reference point. For exemplary purposes, this may be written as ArrayName[latitude-offset] [longitude-offset]. Each unique [latitude-offset] [longitude-offset] may for exemplary purposes point to a unique location in memory where the zone value associated with that geographic location is stored.
[0052] In an alternative embodiment, the offset may be additionally converted in a proportional or scalar calculation, where a particular number of degrees of latitude, for example, are known to equal one data point shift to the right in the table. This requires storing the scalar conversion and an extra scalar calculation to look up the data value for a location, both which may be undesirable.
[0053] Once the offset is calculated, then the memory location is queried and the contents of the memory are returned in the form of a numerical value from 0-3, the meaning which represents whether the dog is comfortably within the safe zone (“3” in the preferred embodiment), or is in the alert, warn or out-of-bounds zones. After GPS location is determined, the only calculation required during operation of the dog collar to determine whether the collar is within the assisted guidance zone is the calculation of offset in latitude and longitude from the reference point in the lower left corner of the tile. This is a very rapid and easy calculation, followed by a near-instantaneous read of the memory contents. In the preferred embodiment then, all numerical representation calculations are performed at the time the outer limit is defined, and then these numerical representation tiles are saved, preferably in non-volatile memory such as within EEPROM, flash memory, or equivalent storage.
[0054] The procedure used to clear a map from memory is also quite simple in the preferred embodiment. Once the user selects the map to delete, the associated tiles in memory are simply rewritten to numerical values of zero.
[0055] When the collar is in use for pet containment, the numerical representation tiles may be swapped into and out of active memory as required. This means that storage of diverse locations does not require storage of every location in between. So, for example, storage of two distinct one acre maps on opposite sides of the earth does not require storing millions of acres of maps. Instead, only those tiles associated with a latitude and longitude actually used by a map are required to be stored in memory. Again, while the use of tiles is not essential to the operation of the present invention, the ability to create these tiles means that with only very modest amounts of memory and processing capability, the present invention may be used to map one or a plurality o f assisted guidance areas literally anywhere on earth.
[0056] A number of other features may also desirably or optionally be incorporated into a preferred embodiment pet assisted guidance system. Using the teachings of the present invention, the collar may be designed to contain an entire and independent pet assisted guidance system. In other words, no additional components would need to be purchased or acquired, nor is there a need for any other external device other than the GPS satellites. The collar will preferably interact directly with GPS signals received from GPS satellites, and may for enablement use a commercially available set of components to determine latitude and longitude.
[0057] When desired, a remote control interface or external device may also be provided, but such device is preferably not mandatory. Where such an interface is provided, assisted guidance areas may also be communicated that are calculated without requiring a person to first walk the perimeter. While not solely limited thereto, this can be particularly helpful at popular places such as at dog parks or other public places that might be frequented by many pet owners. In such case, a map already created for the park will be provided and may, for exemplary purposes, be downloaded to the collar. Additionally, with such an interface a user might draw an assisted guidance area perimeter or even various zones on a map and transmit them to the collar.
[0058] As aforementioned, there will preferably be multiple zones in the assisted guidance area such as the “safe”, “alert” and “warning” zones to train and shape the behavior of a pet. For exemplary purposes, a comforting stimulus may be provided at particular intervals to assure or reassure a dog within the safe zone 16 . Furthermore, such stimulus may be timed in accord with activity of the dog, such as when the dog is moving about and remaining within safe zone 16 . For exemplary purposes and not solely limiting thereto, a comforting tone or recorded sound such as the owner's voice saying “good dog” may be periodically generated. In one embodiment contemplated herein, the velocity of the dog, including direction and speed, will also be calculated. In the event there is a danger of the dog moving outside of the safe zone, the comforting stimulus may be withheld, until the dog is confirmed to be remaining in safe zone 16 .
[0059] The alert zone 14 assigned with a numeric value of “2” may be used to generate a vibration which is preferably very distinct from the comforting tone or “good dog” recording of safe zone 16 . This will preferably gently alert the dog of the transition out of safe zone 16 and to the need to return thereto.
[0060] The warning zone 12 assigned with a numeric value of “1” maybe used to trigger an electrical stimulation. Most preferably, this electrical stimulation will be provided through a set of probes using the technology such as illustrated in U.S. Pat. No. 7,677,204 incorporated by reference herein above, which is considered to be a most humane method of application. Nevertheless, and while much less preferable, other known techniques for electrical stimulation will be considered herein as alternative embodiments. In the warning zone, this stimulation may be relatively mild or medium stimulation.
[0061] Finally, a numeric value of “0” designates a point outside of the warning zone. In this case, initially the dog may be stimulated with a stronger electrical stimulation. However, this stimulation will most preferably not continue indefinitely, which will be recognized to be quite aversive. Instead, the dog will preferably receive input similar to that which would be provided by a skilled trainer if the trainer were there in person and controlling the collar unit. In the foregoing description, time is described as one factor for calculating when to discontinue electrical stimulation. Preferably, in addition to time, the direction of travel of the dog will also be considered. As soon as the dog starts moving towards the safe zone, stimulation will be discontinued irrespective of time outside of the safe zone.
[0062] This allows appropriate pet behavior to be rewarded, thereby improving training effectiveness and success. Nevertheless, the present invention is not solely limited to a particular number of zones, or a particular way to represent those zones. The numerical representations from zero to three are preferred, but any other representations that may be machine stored are contemplated herein.
[0063] Desirably, the accuracy of the GPS determinations may be significantly improved by incorporating a loosely coupled inertial navigation system into the collar. The inertial navigation system may then be used to validate GPS readings, and may also be used to discard outlier position info such as might be produced sporadically. For exemplary purposes, when an inertial system indicates no movement of the dog and a GPS or equivalent determination indicates a sudden multi-meter jump, then the data point indicative of a sudden multi-meter jump can be discarded or ignored.
[0064] An inertial system or biometric system may also optionally be used to pre-alert dog state and predict sudden location changes. This can be used to be more pre-emptive at alerting or warning the dog of impending boundaries. Exemplary biometric indicators might be heart or respiration rate, while a sudden head lifting or movement is an exemplary inertial indicator.
[0065] Inertial, biometric and location-based indicators may further be used to control the frequency of position calculation, which in turn is related to the average power consumption and battery life. So, for exemplary purposes, if the collar is in a dwelling, the GPS may be deactivated. Similarly, if inertial and/or biometric indicators suggest that the dog is sleeping, sampling rate maybe substantially less frequent, if at all, until the dog wakes up. Additionally, when the dog is within the safe zone, the sampling rate may also be less frequent.
[0066] While the preferred embodiment table 10 has been described herein above for the purposes of enablement as cooperative with a self-contained collar apparatus such as that illustrated by Swanson et al in 2007/0204804, it should be apparent that the table 10 incorporating discrete values representative of various zones may be used with other apparatus such as found in many other patents incorporated herein by reference above and other systems, as will be understood and appreciated by those skilled in the art.
[0067] Consequently, while the foregoing details what is felt to be the preferred embodiment of the invention, no material limitations to the scope of the claimed invention are intended. The variants that would be possible from a reading of the present disclosure are too many in number for individual listings herein, though they are understood to be included in the present invention. Further, features and design alternatives that would be obvious to one of ordinary skill in the art are considered to be incorporated herein. The scope of the invention is set forth and particularly described in the claims herein below. | A look-up table is defined by at least one reference point, and rows and columns that are offset from the reference. The table rows and columns correspond to ordinate and abscissa data points representing geographic locations. Each data point offset in the table corresponds to a predefined geographic offset. The look-up table contains machine-stored values at each table location, with each value representing a particular one of several guidance zones. The real-time determination of the guidance zone is made by first determining present location using GPS or other wireless location signals. The corresponding table location is identified by calculating latitudinal and longitudinal offsets from a reference point, and using these offsets as the two indices to access a double-indexed array. The value retrieved from the indexed array identifies the guidance zone. Each guidance zone has an associated set of characteristics used to provide behavioral guidance to an animal. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a National Phase Application of International Application No. PCT/EP2008/062783, filed on Sep. 24, 2008, which claims the benefit of and priority to German patent application no. DE 10 2007 046 226.5-16, filed on Sep. 26, 2007. The disclosures of the above applications are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
The invention relates to a composite component comprising at least one first and one second sheet metal plate with at least one layer of a polymer arranged between the first and the second sheet metal plate, and also a method for the production of a corresponding composite component, and also the use thereof
BACKGROUND
In the automobile industry, lightweight components, which apart from a low weight must also have high strength and rigidity, are used to a considerable degree. Frequently, corresponding lightweight components, for example in the case of a vehicle body, also serve as outer skin panels so that their surfaces must also meet correspondingly high standards. One approach for achieving this aim is to combine different materials. Thus, for example, German patent application DE 10 2004 022 677 A1 discloses composite components which, as a sandwich structure, consist of two outer sheet metal plates and one inner polymer layer, the polymer layer being designed as foam material. However, in order to bond the metal parts to the polymer layer, an adhesive or adhesion promoter must be carefully applied. In addition, a double conveyer is disclosed, which is intended to limit the thickness of the reactive foam layer and to assist the reactive foaming process by heatable sections.
Furthermore, the published European Patent Application EP 1 504 892 A1 discloses the provision of a polymer layer consisting of a polyamide or a polyamide-polyethylene blend between two sheet metal plates. This composite component is, however, capable of improvement with respect to its weight.
SUMMARY OF THE INVENTION
On this basis, an aspect of the present invention is to propose a composite component optimized regarding the weight thereof, which is at the same time simple to produce.
The aspect indicated above is achieved in a first teaching of the present invention for a generic composite component in that the polymer layer has at least one foamed polymer layer of a thermoplastic polymer, wherein the foamed polymer layer comprises gas bubbles with a volume percentage of 1% to 80%, in particular 5% to 70%.
It has been shown that the use of a foamed polymer layer can contribute considerably to reducing the weight of a composite component with the same strength and rigidity. By introducing or forming gas bubbles in the foamed polymer layer, the weight of the composite components and the consumption of polymers can be reduced during the production of the foam layer by corresponding volume percentage substitution, as a result of which the manufacturing costs can also be minimized. Furthermore, by using thermoplastic polymers the utilization of an adhesive as adhesion promoter can be dispensed with, since bonding to the metal component can be achieved by heating and cooling the thermoplastic polymer.
In a first embodiment of the composite component according to the invention, the foamed polymer layer consists of a temperature-resistant, thermoplastic polymer. Temperature-resistant, thermoplastic polymers in the sense of the present invention are for example polymers which do not exhibit a loss of shape during heating to 210° C. for a short time and during heating to 190° C. for at least 20 minutes. The composite component is therefore able to safely withstand in particular subsequent priming stages with ensuing hardening of the priming layer.
If the foamed polymer layer contains a polyamide or polyamide-blend, the material costs for the foamed polymer layer can be kept to a minimum. Furthermore, polyamide and also a corresponding polyamide-blend are temperature-resistant. A preferred polymer blend for example is a polyamide-polyethylene blend, in particular a PA6 polyamide with a proportion of grafted polyethylene and a reactive copolymer.
In a next exemplary embodiment of the composite component according to the invention, the layer thickness of the polymer layer is between 50 μm and 5000 μm, preferably between 200 μm and 1000 μm. With the layer thicknesses mentioned, on the one hand the necessary strength and rigidity of the composite are ensured. On the other hand adequate weight reduction is achieved in relation to solid material.
In a next refined embodiment of the composite component according to the invention, the thickness of the sheet metal plates that are used is between 0.15 and 3.0 mm. Preferably a sheet metal plate thickness of 0.2 to 0.5 mm, in particular 0.2 to 0.4 mm is used, since in this range optimum deformation properties of the composite component according to the invention are ensured, for example with respect to utilization as the outer skin panel of a vehicle body.
In order to adapt the composite component optimally to a specific application, the sheet metal thicknesses of the first and second sheet metal plates can be different.
Likewise, depending on application, the sheet metal plates can consist of a steel alloy also of stainless steel, aluminum, magnesium and/or titanium alloys. Other metals which can be processed into sheet metal plates can also be used for the composite component according to the invention. In particular a combination of different metal alloys or metals can also be used.
In order to optimize the properties of a composite component according to the invention, at least one sheet metal plate is coated on one or both sides. The coatings can, for example, be metallic or also organic. For this purpose, the most varied methods to apply the metallic coatings are available, for example electrolytic deposition, hot-dipping, roll-cladding or also physical vapor deposition or chemical vapor deposition.
It is advantageous if a sheet metal plate is pre-treated with adhesive primer or another pre-treatment. The adhesive properties of the foamed polymer layer are improved by means of the adhesive primer. For this, the coatings can be applied onto the sheet metal plate in a coil coating process, for example. Other application methods are naturally equally available for applying organic coatings. The coating of the composite component, for improving the adhesion of the composite, is usually applied on the interface to the foamed polymer layer. Other functions, for example decorative purposes, corrosion protection purposes or else coatings permitting oil-free shaping of the composite component are also possible. Temporary corrosion protection can be achieved for example by oiling the sheet metal plates. However, the oil is normally thoroughly removed before the composite component is produced.
The composite component according to the invention can be used directly in automobile construction, if after its production this has been shaped in a downstream forming process to a blank or to the finished shape.
In a second teaching of the present invention, the aspect indicated above for a method according to the invention for the production of a composite component is achieved in that a first metal strip is unwound from a first coil and a second metal strip is unwound from a second coil,
a thermoplastic foamed polymer layer is applied onto at least one metal strip; the foamed polymer layer is produced by physically introducing gas bubbles into the polymer melt, so that the foamed polymer layer comprises gas bubbles with a volume percentage of 1% to 80%, preferably 5% to 70%; the first metal strip, the thermoplastic foamed polymer layer and the second metal strip are bonded to one another through the effect of temperature and exertion of pressure and the linear composite component that is produced is wound onto a coil or cut into sheet-like composite components.
As already stated, it has been shown that the use of a thermoplastic foamed polymer layer comprising gas bubbles with a volume percentage of 1% to 80%, preferably 5% to 70% leads to considerable reduction in the weight of a composite component consisting of two sheet metal plates and one intermediate polymer layer and at the same time no longer requires the use of adhesive as adhesion promoter. This simplifies production of the composite component considerably and leads to lighter composite components. If the foamed polymer layer is also produced by physically introducing into the polymer melt gas bubbles with a volume percentage of 1% to 80%, in particular 5% to 70%, the density of the polymer foam that is produced can be directly influenced. The gas used for foaming can for example be air, carbon dioxide, nitrogen or another arbitrary gas or possibly also a combination of gases.
The method for the production of the composite component according to the invention is simplified by the fact that, in a next embodiment, the foamed polymer layer is applied onto the first metal strip as pre-extruded foil or the foamed polymer layer is extruded directly onto the first metal strip. The pre-extruded foil can be simply made available for linear processing of the metal strip by means of a further coil and can be bonded accordingly to the metal strips by applying pressure and heat. A further simplification of the method is achieved if the foamed polymer layer is extruded directly onto the first metal strip, advantage being taken of the fact that the foamed polymer layer, when it is extruded, is directly available in a condition having adhesive properties.
In a next embodiment of the method according to the invention, the first metal strip is heated before the foamed polymer layer is applied and/or the second metal strip is heated before being applied onto the foamed polymer layer. Heating results in the fact that the thermoplastic foamed polymer layer, on its interface with the metal, remains in a soft condition and to this extent promotes good adhesion with the sheet metal plate. Due to the insulating effect of the gas bubbles, temperatures can be kept lower and a wide temperature window for the bonding process is made possible.
Furthermore, it is advantageous to bond the first metal strip, the foamed polymer layer and the second metal strip to one another by using a double band press, wherein regulated control of temperature and pressure and also distance regulation take place inside the double band press. In contrast to the counter-rotating rollers that are normally used, specific influence can be exerted on the adhesion of the foamed polymer layer to the metal strips by means of the double band press via the temperature control and also via the pressure control, and in this respect an improved linear composite component can be made available. In particular more uniform foamed polymer layer thicknesses that can be precisely adjusted especially over the entire width may be obtained with this method so that the composite components manufactured in this way are very suitable for use as outer skin panels with optimum surface properties.
In an advantageous embodiment, the double band press has at least one heating zone and a cooling zone and also optionally a pressure zone. The heating zone and the cooling zone ensure a controlled bonding process within the area of the double press. For the heating zone and the cooling zone, preferably in each case a separate continuous belt is provided for conveying the linear composite component in order to further improve temperature control. The pressure zone that is optionally provided can be used for calibration and can be implemented by a pair of rollers, for example. Higher pressures can be adjusted very precisely by means of a pair of rollers, in order to obtain improved uniformity of the thickness of the linear composite component. As a result, the linear composite component also has an improved surface.
For optimum control of temperature, the second metal strip is preferably heated before bonding with the foamed polymer layer and the first metal strip, so that the second metal strip does not have to be fully heated in the downstream application of pressure.
Improved stability of the bubble formation during the foaming operation of the foamed polymer layer is achieved in a next embodiment in that at least one polar gas or a gas mixture containing at least one polar gas is used for the foaming operation.
If, in a further advantageous embodiment of the method according to the invention, laminating strips, whose outer surface lying on the linear composite component is coated and optionally surface-treated, are used in the double band press, the outer surfaces of the linear composite component can be protected from negative production influences and production faults. For example, laminating strips that are sanded and coated with silicone can achieve very good results with respect to the surface quality of the linear composite component.
Finally, the method according to the invention can be configured further advantageously in that the linear composite component is converted before and/or after separation into sheet-like composite components. This results in a particularly economic method for producing the composite component according to the invention.
In a third teaching of the present invention, the composite component according to the invention is used advantageously in automobile, aircraft, ship, submarine, rail-mounted vehicle construction, space or construction industries. Advantages arise namely as a result of the composite component according to the invention whenever lightweight construction concepts demand weight reduction.
BRIEF DESCRIPTION OF THE DRAWINGS
There are a plurality of possible embodiments of the composite component according to the invention, the production methods according to the invention and use thereof. In this connection, reference is made for illustration purposes to the description of two exemplary embodiments in conjunction with the drawing. The drawing shows in:
FIG. 1 a first exemplary embodiment of a composite component according to the invention in a schematic cutaway view;
FIG. 2 a schematic illustration of a device for executing a first exemplary embodiment of the method according to the invention for the production of a composite component; and
FIG. 3 a schematic illustration of a device for executing a second exemplary embodiment.
DETAILED DESCRIPTION
The composite component 1 illustrated in FIG. 1 consists of a first sheet metal plate 2 , a second sheet metal plate 3 and also a foamed polymer layer 4 arranged between both sheet metal plates. The foamed polymer layer 4 in the present exemplary embodiment of the composite component 1 according to the invention consists of a temperature-resistant polymer foam from a polyamide-polyethylene blend containing air bubbles with a volume percentage of 40%. The mass of the polymer between the sheet metal plates is substantially reduced by using a polymer foam without impairing its physical properties. Due to this weight saving, the composite components 1 according to the invention can be used particularly satisfactorily for lightweight construction concepts in the automobile, aircraft or rail-mounted vehicle construction industries. However, further areas of application in lightweight construction—not mentioned here—are possible due to the properties of the composite components.
In FIG. 2 a device for the production of an exemplary embodiment of a composite component 1 according to the invention is now schematically illustrated. A first metal strip 6 , which is pre-heated in a heating zone 7 , is made available by means of a first coil 5 . The metal strip 6 can consist of the most varied metals or alloys, for example, steel, aluminum, titanium etc. In the case of steel alloys, the metal strip preferably has a thickness of 0.15 to 0.8 mm, so that it can be used particularly satisfactorily as outer skin in the construction of vehicle bodies. When using other metals for the production of the composite component, other thicknesses of the sheet metal plates can also be used.
In the exemplary embodiment illustrated of the method according to the invention, the foamed polymer layer is extruded from an extruder 8 directly onto the first metal strip 6 , wherein the extruder 8 is made up of three units, for example. The first unit 9 melts the polymer granulate, whereas the second unit 10 preferably physically introduces gas bubbles, for example air bubbles, into the polymer melt in order to produce the polymer foam. Finally the polymer melt that is aerated with gas bubbles is extruded by means of an extrusion nozzle 11 onto the metal strip 6 and there forms a foamed polymer layer 4 . The second metal strip 12 is made available by unwinding a coil 13 and is heated in a heating section 14 before contact with the foamed polymer layer 4 . The heating section 14 , just as the heating zone 7 , is adapted to the metal that is to be heated. For example, inductive heating of the metal strip is suitable when using a steel alloy. However, other methods can also be used for heating the metal strip.
Contact between the second metal strip 12 and the foamed polymer layer 4 is preferably first made inside the double band press 15 so that, through defined heating in a, for example, segmented heating zone 15 a at temperatures between 210 and 270° C., the foamed polymer layer 4 aerated with air bubbles is bonded between the metal strips 6 , 12 . The double band press can apply positive pressure of up to 30 bar within the area of the heating zones 15 a . The pressure that is built up is sufficient to even out the heat transmission and to melt on the foamed polymer layer 4 satisfactorily.
In a further stage, in a pressure zone 15 b , for example by means of—not illustrated—pressure rollers, a high line pressure of up to 20 bar can be exerted on the linear composite component 1 , as a result of which the adhesion between sheet metal plate 6 , 11 and foamed polymer layer may be improved. In a third stage, the linear composite component 1 is then specifically cooled down in a segmented cooling zone 15 b , so as to calibrate the total composite thickness. If necessary, an additional cooling unit 16 can be arranged on the outlet side of the two-stage double band press, so that the temperature in the linear composite component 1 can be reduced further, for example by means of spraying.
Subsequently, the linear composite component 1 can undergo separation or shaping in order to produce a finished composite component or a semi-finished product. Corresponding devices are not illustrated in FIG. 2 .
Finally, FIG. 3 in a schematic view shows a device for executing a second exemplary embodiment of the method according to the invention, wherein a first metal strip 6 is heated by means of a heating roller 17 a . The temperature of the heating roller 17 can reach 240° C., for example. The extruder 18 directly extrudes a foamed polymer layer 4 onto the first metal strip 6 , wherein inside the extruder gas is physically introduced under pressure into the plastic melt, which gas expands when the pressure is released at the outlet of the extruder 18 and forms fine gas bubbles. The gas bubbles can have a volume percentage of 1 to 80%, preferably 5 to 70%. With the gas bubbles having a volume percentage of 40%, likewise very good results were obtained. Alternatively, however, the foamed polymer layer can also be applied as foil 4 ′ by means of a coil 18 a , which is indicated in FIG. 3 .
High process stability during gas bubble formation resulted by using a polyamide-polyethylene blend in conjunction with a mixture of a polar gas, for example oxygen and a non-polar gas, for example nitrogen. Good results were therefore also obtained by using air to form the bubbles.
Before being fed into the double band press 20 , edge strip re-granulation is carried out using a device 19 , which removes and reprocesses residues of the foamed polymer layer, and for example crushes them up again so they can be returned to the production process.
The second metal strip 12 is then unwound by means of a coil 13 and applied by means of a heating roller 17 b onto the foamed polymer layer 4 . Due to the high temperature of the second metal strip, bonding between the second metal strip and the foamed polymer layer 4 can take place by melting on of the foamed polymer layer 4 . For this purpose, the first metal strip 6 with the foamed polymer layer 4 arranged thereon and the second metal strip 12 are fed into the double band press 20 .
The double band press 20 has three sections, a heating zone 21 , a pressure zone 22 and a cooling zone 23 , the cooling zone 23 and the heating zone 21 each comprising separated laminating strips 24 a , 24 b , 24 c , 24 d . Preferably, the laminating strips have coated and processed surfaces. With the present exemplary embodiment, in the case of a low pressure of approximately 0.2 to 0.5 bar, a temperature of approximately 230° C. is adjusted in the heating zone 21 by means of a temperature-adjusting medium flowing through the plates 25 a and 25 c . In addition, the temperature-adjusting medium can also have higher temperatures, for example 260° C.
Laminating rollers 22 a and 22 b , which form the pressure zone 22 in the present exemplary embodiment, exert a pressure, which for example can lie in the range of approximately 12 bar, on the linear composite component 1 after it has run through the heating zone 21 . Irregularities, for example in the thickness of the linear composite component, are evened out as a result. However, it is also conceivable that higher pressures can be exerted on the composite component by the laminating rollers. For example, the pressure can reach up to 50 or 100 kN.
Preferably, the gap which is formed by the laminating strips 24 a and 24 c in the heating zone 21 runs together in a wedge-shape, so that the foamed polymer layer 4 is compressed. In order to improve uniformity, the plates 25 a and 25 c and also 25 b and 25 d are arranged offset by half a plate against one another.
In the cooling zone 23 , the linear composite component 1 is cooled down to a temperature of less than 180° C. By means of the plates 25 b and 25 d , a pressure of approximately 0.2 to 0.5 bar continues to be exerted on the composite component 1 . Due to the low pressures, edge sealing, as was usual up to now whenever high pressures were used, is no longer necessary and as a result the production method is considerably simplified.
For this purpose, a cooling agent flows through the plates 25 b and 25 d . For example, a cooling agent at a temperature of 20° C. can flow through the plates 25 b and 25 d in order to achieve considerable cooling of the composite component. Afterwards the linear composite component 1 passes through at least one cooling device 26 . Cooling takes place by water-spraying 26 a and subsequent squeeze-rolling 26 b to remove the water. | A composite component comprising at least one first and one second sheet metal plate with at least one layer of a polymer arranged between the first and the second sheet metal plates provides for a component optimized with respect to the weight thereof, and which is at the same time simple to manufacture. The polymer layer of the composite component according to the invention comprises at least one foamed polymer layer of a thermoplastic polymer, wherein the foamed polymer layer comprises gas bubbles with a volume percentage of 1% to 80%, in particular 5% to 70%. | 1 |
RELATED APPLICATIONS
[0001] The present application is a divisional of U.S. Ser. No. 13/844,206, filed Mar. 15, 2013 (now pending), which is a divisional of U.S. application Ser. No. 11/847,192, filed Aug. 29, 2007 (now pending), which in turn is a divisional of U.S. application Ser. No. 10/837,525, filed Apr. 29, 2004 (now U.S. Pat. No. 7,279,451), which in turn is a continuation in part of each of U.S. application Ser. No. 10/694,272, filed Oct. 27, 2003 (now U.S. Pat. No. 7,230,146) and U.S. patent application Ser. No. 10/694,273, filed Oct. 27, 2003 (now U.S. Pat. No. 7,534,366), which in turn is related to and claims the priority benefit of U.S. Provisional Application Nos. 60/421,263 and 60/421,435, each of which was filed on Oct. 25, 2002. U.S. patent application Ser. No. 10/837,525, filed Apr. 29, 2004 is also a continuation-in-part of U.S. patent application Ser. No. 10/694,272, filed Oct. 27, 2003 (now U.S. Pat. No. 7,230,146). The disclosure of each of the aforementioned patent applications and patents is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates to compositions having utility in numerous applications, including particularly refrigeration systems, and to methods and systems utilizing such compositions. In preferred aspects, the present invention is directed to refrigerant compositions comprising at least one multi-fluorinated olefin of the present invention.
BACKGROUND OF THE INVENTION
[0003] Fluorocarbon based fluids have found widespread use in many commercial and industrial applications. For example, fluorocarbon based fluids are frequently used as a working fluid in systems such as air conditioning, heat pump and refrigeration applications. The vapor compression cycle is one of the most commonly used type methods to accomplish cooling or heating in a refrigeration system. The vapor compression cycle usually involves the phase change of the refrigerant from the liquid to the vapor phase through heat absorption at a relatively low pressure and then from the vapor to the liquid phase through heat removal at a relatively low pressure and temperature, compressing the vapor to a relatively elevated pressure, condensing the vapor to the liquid phase through heat removal at this relatively elevated pressure and temperature, and then reducing the pressure to start the cycle over again.
[0004] While the primary purpose of refrigeration is to remove heat from an object or other fluid at a relatively low temperature, the primary purpose of a heat pump is to add heat at a higher temperature relative to the environment.
[0005] Certain fluorocarbons have been a preferred component in many heat exchange fluids, such as refrigerants, for many years in many applications. For, example, fluoroalkanes, such as chlorofluoromethane and chlorofluoroethane derivatives, have gained widespread use as refrigerants in applications including air conditioning and heat pump applications owing to their unique combination of chemical and physical properties. Many of the refrigerants commonly utilized in vapor compression systems are either single components fluids or azeotropic mixtures.
[0006] Concern has increased in recent years about potential damage to the earth's atmosphere and climate, and certain chlorine-based compounds have been identified as particularly problematic in this regard. The use of chlorine-containing compositions (such as chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and the like) as refrigerants in air-conditioning and refrigeration systems has become disfavored because of the ozone-depleting properties associated with many of such compounds. There has thus been an increasing need for new fluorocarbon and hydrofluorocarbon compounds and compositions that offer alternatives for refrigeration and heat pump applications. For example, it has become desirable to retrofit chlorine-containing refrigeration systems by replacing chlorine-containing refrigerants with non-chlorine-containing refrigerant compounds that will not deplete the ozone layer, such as hydrofluorocarbons (HFCs).
[0007] It is generally considered important, however, that any potential substitute refrigerant must also possess those properties present in many of the most widely used fluids, such as excellent heat transfer properties, chemical stability, low- or no-toxicity, non-flammability and lubricant compatibility, among others.
[0008] Applicants have come to appreciate that lubricant compatibility is of particular importance in many of applications. More particularly, it is highly desirably for refrigeration fluids to be compatible with the lubricant utilized in the compressor unit, used in most refrigeration systems. Unfortunately, many non-chlorine-containing refrigeration fluids, including HFCs, are relatively insoluble and/or immiscible in the types of lubricants used traditionally with CFC's and HFCs, including, for example, mineral oils, alkylbenzenes or poly(alpha-olefins). In order for a refrigeration fluid-lubricant combination to work at a desirable level of efficiently within a compression refrigeration, air-conditioning and/or heat pump system, the lubricant should be sufficiently soluble in the refrigeration liquid over a wide range of operating temperatures. Such solubility lowers the viscosity of the lubricant and allows it to flow more easily throughout the system. In the absence of such solubility, lubricants tend to become lodged in the coils of the evaporator of the refrigeration, air-conditioning or heat pump system, as well as other parts of the system, and thus reduce the system efficiency.
[0009] With regard to efficiency in use, it is important to note that a loss in refrigerant thermodynamic performance or energy efficiency may have secondary environmental impacts through increased fossil fuel usage arising from an increased demand for electrical energy.
[0010] Furthermore, it is generally considered desirably for CFC refrigerant substitutes to be effective without major engineering changes to conventional vapor compression technology currently used with CFC refrigerants.
[0011] Flammability is another important property for many applications. That is, it is considered either important or essential in many applications, including particularly in heat transfer applications, to use compositions, which are non-flammable. Thus, it is frequently beneficial to use in such compositions compounds, which are nonflammable. As used herein, the term “nonflammable” refers to compounds or compositions, which are determined to be nonflammable as determined in accordance with ASTM standard E-681, dated 2002, which is incorporated herein by reference. Unfortunately, many HFCs, which might otherwise be desirable for used in refrigerant compositions are not nonflammable. For example, the fluoroalkane difluoroethane (HFC-152a) and the fluoroalkene 1,1,1-trifluoropropene (HFO-1243zf) are each flammable and therefore not viable for use in many applications.
[0012] Higher fluoroalkenes, that is fluorine-substituted alkenes having at least five carbon atoms, have been suggested for use as refrigerants. U.S. Pat. No. 4,788,352—Smutny is directed to production of fluorinated C 5 to C 8 compounds having at least some degree of unsaturation. The Smutny patent identifies such higher olefins as being known to have utility as refrigerants, pesticides, dielectric fluids, heat transfer fluids, solvents, and intermediates in various chemical reactions. (See column 1, lines 11-22).
[0013] While the fluorinated olefins described in Smutny may have some level of effectiveness in heat transfer applications, it is believed that such compounds may also have certain disadvantages. For example, some of these compounds may tend to attack substrates, particularly general-purpose plastics such as acrylic resins and ABS resins. Furthermore, the higher olefinic compounds described in Smutny may also be undesirable in certain applications because of the potential level of toxicity of such compounds which may arise as a result of pesticide activity noted in Smutny. Also, such compounds may have a boiling point, which is too high to make them useful as a refrigerant in certain applications.
[0014] Bromofluoromethane and bromochlorofluoromethane derivatives, particularly bromotrifluoromethane (Halon 1301) and bromochlorodifluoromethane (Halon 1211) have gained widespread use as fire extinguishing agents in enclosed areas such as airplane cabins and computer rooms. However, the use of various halons is being phased out due to their high ozone depletion. Moreover, as halons are frequently used in areas where humans are present, suitable replacements must also be safe to humans at concentrations necessary to suppress or extinguish fire.
[0015] Applicants have thus come to appreciate a need for compositions, and particularly heat transfer compositions, fire extinguishing/suppression compositions, blowing agents, solvent compositions, and compatabilizing agents, that are potentially useful in numerous applications, including vapor compression heating and cooling systems and methods, while avoiding one or more of the disadvantages noted above.
SUMMARY
[0016] Applicants have found that the above-noted need, and other needs, can be satisfied by compositions comprising one or more C3 or C4 fluoroalkenes, preferably compounds having Formula I as follows:
[0000] XCF z R 3-z (I)
[0000] where X is a C 2 or a C 3 unsaturated, substituted or unsubstituted, alkyl radical, each R is independently Cl, F, Br, I or H, and z is 1 to 3. Highly preferred among the compounds of Formula I are the cis- and trans-isomers of 1,3,3,3-tetrafluoropropene (HFO-1234ze)
[0017] The present invention provides also methods and systems which utilize the compositions of the present invention, including methods and systems for heat transfer, foam blowing, solvating, flavor and fragrance extraction and/or delivery, and aerosol generation.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0018] The Compositions
[0019] The present invention is directed to compositions comprising at least one fluoroalkene containing from 3 to 4 carbon atoms, preferably three carbon atoms, and at least one carbon-carbon double bond. The fluoroalkene compounds of the present invention are sometimes referred to herein for the purpose of convenience as hydrofluoro-olefins or “HFOs” if they contain at least one hydrogen. Although it is contemplated that the HFOs of the present invention may contain two carbon—carbon double bonds, such compounds at the present time are not considered to be preferred.
[0020] As mentioned above, the present compositions comprise one or more compounds in accordance with Formula I. In preferred embodiments, the compositions include compounds of Formula II below:
[0000]
[0000] where each R is independently Cl, F, Br, I or H
[0021] R′ is (CR 2 ) n Y,
[0022] Y is CRF 2
[0023] and n is 0 or 1.
[0000] In highly preferred embodiments, Y is CF 3 , n is 0 and at least one of the remaining Rs is F.
[0024] Applicants believe that, in general, the compounds of the above identified Formulas I and II are generally effective and exhibit utility in refrigerant compositions, blowing agent compositions, compatibilizers, aerosols, propellants, fragrances, flavor formulations, and solvent compositions of the present invention. However, applicants have surprisingly and unexpectedly found that certain of the compounds having a structure in accordance with the formulas described above exhibit a highly desirable low level of toxicity compared to other of such compounds. As can be readily appreciated, this discovery is of potentially enormous advantage and benefit for the formulation of not only refrigerant compositions, but also any and all compositions, which would otherwise contain relatively toxic compounds satisfying the formulas described above. More particularly, applicants believe that a relatively low toxicity level is associated with compounds of Formula II, preferably wherein Y is CF 3 , wherein at least one R on the unsaturated terminal carbon is H, and at least one of the remaining Rs is F. Applicants believe also that all structural, geometric and stereoisomers of such compounds are effective and of beneficially low toxicity.
[0025] In highly preferred embodiments, especially embodiments comprising the low toxicity compounds described above, n is zero in which the unsaturated terminal carbon has not more than one F substituent. Applicant has discovered that such compounds have a very low acute toxicity level, as measured by inhalation expoure to mice and rats. In certain highly preferred embodiments the compositions of the present invention comprise one or more tetrafluoropropenes. The term “HFO-1234” is used herein to refer to all tetrafluoropropenes. Among the tetrafluoropropenes, both cis- and trans-1,3,3,3-tetrafluoropropene (HFO-1234ze) are particularly preferred. The term HFO-1234ze is used herein generically to refer to 1,3,3,3-tetrafluoropropene, independent of whether it is the cis- or trans-form. The terms “cisHFO-1234ze” and “transHFO-1234ze” are used herein to describe the cis- and trans-forms of 1,3,3,3-tetrafluoropropene respectively. The term “HFQ-1234ze” therefore includes within its scope cisHFO-1234ze, transHFO-1234ze, and all combinations and mixtures of these.
[0026] Although the properties of cisHFO-1234ze and transHFO-1234ze differ in at least some respects, it is contemplated that each of these compounds is adaptable for use, either alone or together with other compounds including its stereoisomer, in connection with each of the applications, methods and systems described herein. For example, while transHFO-1234ze may be preferred for use in certain refrigeration systems because of its relatively low boiling point (−19° C.), it is nevertheless contemplated that cisHFO-1234ze, with a boiling point of +9° C., also has utility in certain refrigeration systems of the present invention. Accordingly, it is to be understood that the terms “HFO-1234ze” and 1,3,3,3-tetrafluoropropene refer to both stereo isomers, and the use of this term is intended to indicate that each of the cis- and trans-forms applies and/or is useful for the stated purpose unless otherwise indicated.
[0027] HFO-1234 compounds are known materials and are listed in Chemical Abstracts databases. The production of fluoropropenes such as CF 3 CH═CH by catalytic vapor phase fluorination of various saturated and unsaturated halogen-containing C 3 compounds is described in U.S. Pat. Nos. 2,889,379; 4,798,818 and 4,465,786, each of which is incorporated herein by reference. EP 974,571, also incorporated herein by reference, discloses the preparation of 1,1,1,3-tetrafluoropropene by contacting 1,1,1,3,3-pentafluoropropane (HFC-245fa) in the vapor phase with a chromium-based catalyst at elevated temperature, or in the liquid phase with an alcoholic solution of KOH, NaOH, Ca(OH) 2 or Mg(OH) 2 . In addition, methods for producing compounds in accordance with the present invention are described generally in connection with pending United States Patent Application entitled “Process for Producing Fluoropropenes” bearing attorney docket number (H0003789 (26267)), which is also incorporated herein by reference.
[0028] The present compositions, particularly those comprising HFO-1234ze, are believed to possess properties that are advantageous for a number of important reasons. For example, applicants believe, based at least in part on mathematical modeling, that the fluoroolefins of the present invention will not have a substantial negative affect on atmospheric chemistry, being negligible contributors to ozone depletion in comparison to some other halogenated species. The preferred compositions of the present invention thus have the advantage of not contributing substantially to ozone depletion. The preferred compositions also do not contribute substantially to global warming compared to many of the hydrofluoroalkanes presently in use.
[0029] In certain preferred forms, compositions of the present invention have a Global Warming Potential (GWP) of not greater than about 1000, more preferably not greater than about 500, and even more preferably not greater than about 150. In certain embodiments, the GWP of the present compositions is not greater than about 100 and even more preferably not greater than about 75. As used herein, “GWP” is measured relative to that of carbon dioxide and over a 100-year time horizon, as defined in “The Scientific Assessment of Ozone Depletion, 2002, a report of the World Meteorological Association's Global Ozone Research and Monitoring Project,” which is incorporated herein by reference.
[0030] In certain preferred forms, the present compositions also preferably have an Ozone Depletion Potential (ODP) of not greater than 0.05, more preferably not greater than 0.02 and even more preferably about zero. As used herein, “ODP” is as defined in “The Scientific Assessment of Ozone Depletion, 2002, A report of the World Meteorological Association's Global Ozone Research and Monitoring Project,” which is incorporated herein by reference.
[0031] The amount of the Formula I compounds, particularly HFO-1234, contained in the present compositions can vary widely, depending the particular application, and compositions containing more than trace amounts and less than 100% of the compound are within broad the scope of the present invention. Moreover, the compositions of the present invention can be azeotropic, azeotrope-like or non-azeotropic. In preferred embodiments, the present compositions comprise HFO-1234, preferably HFO-1234ze, in amounts from about 5% by weight to about 99% by weight, and even more preferably from about 5% to about 95%. Many additional compounds may be included in the present compositions, and the presence of all such compounds is within the broad scope of the invention. In certain preferred embodiments, the present compositions include, in addition to HFO-1234ze, one or more of the following:
[0032] Difluoromethane (HFC-32)
[0033] Pentafluoroethane (HFC-125)
[0034] 1,1,2,2-tetrafluoroethane (HFC-134)
[0035] 1,1,1,2-Tetrafluoroethane (HFC-134a)
[0036] Difluoroethane (HFC-152a)
[0037] 1,1,1,2,3,3,3-Heptafluoropropane (HFC-227ea)
[0038] 1,1,1,3,3,3-hexafluoropropane (HFC-236fa)
[0039] 1,1,1,3,3-pentafluoropropane (HFC-245fa)
[0040] 1,1,1,3,3-pentafluorobutane (HFC-365mfc)
[0041] water
[0042] CO 2
[0000] The relative amount of any of the above noted components, as well as any additional components which may be included in present compositions, can vary widely within the general broad scope of the present invention according to the particular application for the composition, and all such relative amounts are considered to be within the scope hereof.
[0043] Heat Transfer Compositions
[0044] Although it is contemplated that the compositions of the present invention may include the compounds of the present invention in widely ranging amounts, it is generally preferred that refrigerant compositions of the present invention comprise compound(s) in accordance with Formula I, more preferably in accordance with Formula II, and even more preferably HFO-1234ze, in an amount that is at least about 50% by weight, and even more preferably at least about 70% by weight, of the composition. In many embodiments, it is preferred that the heat transfer compositions of the present invention comprise transHFO-1234ze. In certain preferred embodiments, the heat transfer compositions of the present invention comprise a combination of cisHFO-1234ze and transHFO1234ze in a cis:trans weight ratio of from about 1:99 to about 10:99, more preferably from about 1:99 to about 5:95, and even more preferably from about 1:99 to about 3:97.
[0045] The compositions of the present invention may include other components for the purpose of enhancing or providing certain functionality to the composition, or in some cases to reduce the cost of the composition. For example, refrigerant compositions according to the present invention, especially those used in vapor compression systems, include a lubricant, generally in amounts of from about 30 to about 50 percent by weight of the composition. Furthermore, the present compositions may also include a compatibilizer, such as propane, for the purpose of aiding compatibility and/or solubility of the lubricant. Such compatibilizers, including propane, butanes and pentanes, are preferably present in amounts of from about 0.5 to about 5 percent by weight of the composition. Combinations of surfactants and solubilizing agents may also be added to the present compositions to aid oil solubility, as disclosed by U.S. Pat. No. 6,516,837, the disclosure of which is incorporated by reference. Commonly used refrigeration lubricants such as Polyol Esters (POEs) and Poly Alkylene Glycols (PAGs), silicone oil, mineral oil, alkyl benzenes (ABs) and poly(alpha-olefin) (PAO) that are used in refrigeration machinery with hydrofluorocarbon (HFC) refrigerants may be used with the refrigerant compositions of the present invention.
[0046] Many existing refrigeration systems are currently adapted for use in connection with existing refrigerants, and the compositions of the present invention are believed to be adaptable for use in many of such systems, either with or without system modification. In many applications the compositions of the present invention may provide an advantage as a replacement in systems, which are currently based on refrigerants having a relatively high capacity. Furthermore, in embodiments where it is desired to use a lower capacity refrigerant composition of the present invention, for reasons of cost for example, to replace a refrigerant of higher capacity, such embodiments of the present compositions provide a potential advantage. Thus, It is preferred in certain embodiments to use compositions of the present invention, particularly compositions comprising a substantial proportion of, and in some embodiments consisting essentially of transHFO-1234ze, as a replacement for existing refrigerants, such as HFC-134a. In certain applications, the refrigerants of the present invention potentially permit the beneficial use of larger displacement compressors, thereby resulting in better energy efficiency than other refrigerants, such as HFC-134a. Therefore the refrigerant compositions of the present invention, particularly compositions comprising transHFP-1234ze, provide the possibility of achieving a competitive advantage on an energy basis for refrigerant replacement applications.
[0047] It is contemplated that the compositions of the present, including particularly those comprising HFO-1234ze, also have advantage (either in original systems or when used as a replacement for refrigerants such as R-12 and R-500), in chillers typically used in connection with commercial air conditioning systems. In certain of such embodiments it is preferred to including in the present HFO-1234ze compositions from about 0.5 to about 5% of a flammability suppressant, such as CF3I.
[0048] The present methods, systems and compositions are thus adaptable for use in connection with automotive air conditioning systems and devices, commercial refrigeration systems and devices, chillers, residential refrigerator and freezers, general air conditioning systems, heat pumps, and the like.
[0049] Blowing Agents, Foams and Foamable Compositions
[0050] Blowing agents may also comprise or constitute one or more of the present compositions. As mentioned above, the compositions of the present invention may include the compounds of the present invention in widely ranging amounts. It is generally preferred, however, that for preferred compositions for use as blowing agents in accordance with the present invention, compound(s) in accordance with Formula I, and even more preferably Formula II, are present in an amount that is at least about 5% by weight, and even more preferably at least about 15% by weight, of the composition. In certain preferred embodiments, the blowing agent compositions of the present invention and include, in addition to HFO-1234 (preferably HFO-1234ze) one or more of the following components as a co-blowing agent, filler, vapor pressure modifier, or for any other purpose:
[0051] Difluoromethane (HFC-32)
[0052] Pentafluoroethane (HFC-125)
[0053] 1,1,2,2-tetrafluoroethane (HFC-134)
[0054] 1,1,1,2-Tetrafluoroethane (HFC-134a)
[0055] Difluoroethane (HFC-152a)
[0056] 1,1,1,2,3,3,3-Heptafluoropropane (HFC-227ea)
[0057] 1,1,1,3,3,3-hexafluoropropane (HFC-236fa)
[0058] 1,1,1,3,3-pentafluoropropane (HFC-245fa)
[0059] 1,1,1,3,3-pentafluorobutane (HFC-365mfc)
[0060] water
[0061] CO 2
[0000] it is contemplated that the blowing agent compositions of the present invention may comprise cisHFO-1234ze, transHFO1234ze or combinations thereof. In certain preferred embodiments, the blowing agent composition of the present invention comprise his a combination of cisHFO-1234ze and transHFO1234ze in a cis:trans weight ratio of from about 1:99 to about 10:99, and even more preferably from about 1:99 to about 5:95.
[0062] In other embodiments, the invention provides foamable compositions, and preferably polyurethane, polyisocyanurate and extruded thermoplastic foam compositions, prepared using the compositions of the present invention. In such foam embodiments, one or more of the present compositions are included as or part of a blowing agent in a foamable composition, which composition preferably includes one or more additional components capable of reacting and/or foaming under the proper conditions to form a foam or cellular structure, as is well known in the art. The invention also relates to foam, and preferably closed cell foam, prepared from a polymer foam formulation containing a blowing agent comprising the compositions of the invention. In yet other embodiments, the invention provides foamable compositions comprising thermoplastic or polyolefin foams, such as polystyrene (PS), polyethylene (PE), polypropylene (PP) and polyethyleneterpthalate (PET) foams, preferably low-density foams.
[0063] In certain preferred embodiments, dispersing agents, cell stabilizers, surfactants and other additives may also be incorporated into the blowing agent compositions of the present invention. Surfactants are optionally but preferably added to serve as cell stabilizers. Some representative materials are sold under the names of DC-193, B-8404, and L-5340 which are, generally, polysiloxane polyoxyalkylene block co-polymers such as those disclosed in U.S. Pat. Nos. 2,834,748, 2,917,480, and 2,846,458, each of which is incorporated herein by reference. Other optional additives for the blowing agent mixture may include flame retardants such as tri(2-chloroethyl)phosphate, tri(2-chloropropyl)phosphate, tri(2,3-dibromopropyl)-phosphate, tri(1,3-dichloropropyl)phosphate, diammonium phosphate, various halogenated aromatic compounds, antimony oxide, aluminum trihydrate, polyvinyl chloride, and the like.
[0064] Propellant and Aerosol Compositions
[0065] In another aspect, the present invention provides propellant compositions comprising or consisting essentially of a composition of the present invention, such propellant composition preferably being a sprayable composition. The propellant compositions of the present invention preferably comprise a material to be sprayed and a propellant comprising, consisting essentially of, or consisting of a composition in accordance with the present invention. Inert ingredients, solvents, and other materials may also be present in the sprayable mixture. Preferably, the sprayable composition is an aerosol. Suitable materials to be sprayed include, without limitation, cosmetic materials such as deodorants, perfumes, hair sprays, cleansers, and polishing agents as well as medicinal materials such as anti-asthma components, anti-halitosis components and any other medication or the like, including preferably any other medicament or agent intended to be inhaled. The medicament or other therapeutic agent is preferably present in the composition in a therapeutic amount, with a substantial portion of the balance of the composition comprising a compound of Formula I of the present invention, preferably HFO-1234, and even more preferably HFO-1234ze.
[0066] Aerosol products for industrial, consumer or medical use typically contain one or more propellants along with one or more active ingredients, inert ingredients or solvents. The propellant provides the force that expels the product in aerosolized form. While some aerosol products are propelled with compressed gases like carbon dioxide, nitrogen, nitrous oxide and even air, most commercial aerosols use liquefied gas propellants. The most commonly used liquefied gas propellants are hydrocarbons such as butane, isobutane, and propane. Dimethyl ether and HFC-152a (1,1-difluoroethane) are also used, either alone or in blends with the hydrocarbon propellants. Unfortunately, all of these liquefied gas propellants are highly flammable and their incorporation into aerosol formulations will often result in flammable aerosol products.
[0067] Applicants have come to appreciate the continuing need for nonflammable, liquefied gas propellants with which to formulate aerosol products. The present invention provides compositions of the present invention, particularly and preferably compositions comprising HFO-1234, and even more preferably HFO-1234ze, for use in certain industrial aerosol products, including for example spray cleaners, lubricants, and the like, and in medicinal aerosols, including for example to deliver medications to the lungs or mucosal membranes. Examples of this includes metered dose inhalers (MDIs) for the treatment of asthma and other chronic obstructive pulmonary diseases and for delivery of medicaments to accessible mucous membranes or intranasally. The present invention thus includes methods for treating ailments, diseases and similar health related problems of an organism (such as a human or animal) comprising applying a composition of the present invention containing a medicament or other therapeutic component to the organism in need of treatment. In certain preferred embodiments, the step of applying the present composition comprises providing a MDI containing the composition of the present invention (for example, introducing the composition into the MDI) and then discharging the present composition from the MDI.
[0068] The compositions of the present invention, particularly compositions comprising or consisting essentially of HFO-1234ze, are capable of providing nonflammable, liquefied gas propellant and aerosols that do not contribute substantially to global warming. The present compositions can be used to formulate a variety of industrial aerosols or other sprayable compositions such as contact cleaners, dusters, lubricant sprays, and the like, and consumer aerosols such as personal care products, household products and automotive products. HFO-1234ze is particularly preferred for use as an important component of propellant compositions for in medicinal aerosols such as metered dose inhalers. The medicinal aerosol and/or propellant and/or sprayable compositions of the present invention in many applications include, in addition to compound of formula (I) or (II) (preferably HFO-1234ze), a medicament such as a beta-agonist, a corticosteroid or other medicament, and, optionally, other ingredients, such as surfactants, solvents, other propellants, flavorants and other excipients. The compositions of the present invention, unlike many compositions previously used in these applications, have good environmental properties and are not considered to be potential contributors to global warming. The present compositions therefore provide in certain preferred embodiments substantially nonflammable, liquefied gas propellants having very low Global Warming potentials.
[0069] Flavorants and Fragrances
[0070] The compositions of the present invention also provide advantage when used as part of, and in particular as a carrier for, flavor formulations and fragrance formulations. The suitability of the present compositions for this purpose is demonstrated by a test procedure in which 0.39 grams of Jasmone were put into a heavy walled glass tube. 1.73 grams of R-1234ze were added to the glass tube. The tube was then frozen and sealed. Upon thawing the tube, it was found that the mixture had one liquid phase. The solution contained 20 wt. % Jasome and 80 wt. % R-1234ze, thus establishing its favorable use as a carrier or part of delivery system for flavor formulations, in aerosol and other formulations. It also establishes its potential as an extractant of fragrances, including from plant matter.
[0071] Methods and Systems
[0072] The compositions of the present invention are useful in connection with numerous methods and systems, including as heat transfer fluids in methods and systems for transferring heat, such as refrigerants used in refrigeration, air conditioning and heat pump systems. The present compositions are also advantageous for in use in systems and methods of generating aerosols, preferably comprising or consisting of the aerosol propellant in such systems and methods. Methods of forming foams and methods of extinguishing and suppressing fire are also included in certain aspects of the present invention. The present invention also provides in certain aspects methods of removing residue from articles in which the present compositions are used as solvent compositions in such methods and systems.
[0073] Heat Transfer Methods
[0074] The preferred heat transfer methods generally comprise providing a composition of the present invention and causing heat to be transferred to or from the composition changing the phase of the composition. For example, the present methods provide cooling by absorbing heat from a fluid or article, preferably by evaporating the present refrigerant composition in the vicinity of the body or fluid to be cooled to produce vapor comprising the present composition. Preferably the methods include the further step of compressing the refrigerant vapor, usually with a compressor or similar equipment to produce vapor of the present composition at a relatively elevated pressure. Generally, the step of compressing the vapor results in the addition of heat to the vapor, thus causing an increase in the temperature of the relatively high-pressure vapor. Preferably, the present methods include removing from this relatively high temperature, high pressure vapor at least a portion of the heat added by the evaporation and compression steps. The heat removal step preferably includes condensing the high temperature, high-pressure vapor while the vapor is in a relatively high-pressure condition to produce a relatively high-pressure liquid comprising a composition of the present invention. This relatively high-pressure liquid preferably then undergoes a nominally isoenthalpic reduction in pressure to produce a relatively low temperature, low-pressure liquid. In such embodiments, it is this reduced temperature refrigerant liquid which is then vaporized by heat transferred from the body or fluid to be cooled.
[0075] In another process embodiment of the invention, the compositions of the invention may be used in a method for producing heating which comprises condensing a refrigerant comprising the compositions in the vicinity of a liquid or body to be heated. Such methods, as mentioned hereinbefore, frequently are reverse cycles to the refrigeration cycle described above.
[0076] Foam Blowing Methods
[0077] One embodiment of the present invention relates to methods of forming foams, and preferably polyurethane and polyisocyanurate foams. The methods generally comprise providing a blowing agent composition of the present inventions, adding (directly or indirectly) the blowing agent composition to a foamable composition, and reacting the foamable composition under the conditions effective to form a foam or cellular structure, as is well known in the art. Any of the methods well known in the art, such as those described in “Polyurethanes Chemistry and Technology,” Volumes I and II, Saunders and Frisch, 1962, John Wiley and Sons, New York, N.Y., which is incorporated herein by reference, may be used or adapted for use in accordance with the foam embodiments of the present invention. In general, such preferred methods comprise preparing polyurethane or polyisocyanurate foams by combining an isocyanate, a polyol or mixture of polyols, a blowing agent or mixture of blowing agents comprising one or more of the present compositions, and other materials such as catalysts, surfactants, and optionally, flame retardants, colorants, or other additives.
[0078] It is convenient in many applications to provide the components for polyurethane or polyisocyanurate foams in pre-blended formulations. Most typically, the foam formulation is pre-blended into two components. The isocyanate and optionally certain surfactants and blowing agents comprise the first component, commonly referred to as the “A” component. The polyol or polyol mixture, surfactant, catalysts, blowing agents, flame retardant, and other isocyanate reactive components comprise the second component, commonly referred to as the “B” component. Accordingly, polyurethane or polyisocyanurate foams are readily prepared by bringing together the A and B side components either by hand mix for small preparations and, preferably, machine mix techniques to form blocks, slabs, laminates, pour-in-place panels and other items, spray applied foams, froths, and the like. Optionally, other ingredients such as fire retardants, colorants, auxiliary blowing agents, and even other polyols can be added as a third stream to the mix head or reaction site. Most preferably, however, they are all incorporated into one B-component as described above.
[0079] It is also possible to produce thermoplastic foams using the compositions of the invention. For example, conventional polystyrene and polyethylene formulations may be combined with the compositions in a conventional manner to produce rigid foams.
[0080] Cleaning Methods
[0081] The present invention also provides methods of removing containments from a product, part, component, substrate, or any other article or portion thereof by applying to the article a composition of the present invention. For the purposes of convenience, the term “article” is used herein to refer to all such products, parts, components, substrates, and the like and is further intended to refer to any surface or portion thereof. Furthermore, the term “contaminant” is intended to refer to any unwanted material or substance present on the article, even if such substance is placed on the article intentionally. For example, in the manufacture of semiconductor devices it is common to deposit a photoresist material onto a substrate to form a mask for the etching operation and to subsequently remove the photoresist material from the substrate. The term “contaminant” as used herein is intended to cover and encompass such a photo resist material.
[0082] Preferred methods of the present invention comprise applying the present composition to the article. Although it is contemplated that numerous and varied cleaning techniques can employ the compositions of the present invention to good advantage, it is considered to be particularly advantageous to use the present compositions in connection with supercritical cleaning techniques. Supercritical cleaning is disclosed in U.S. Pat. No. 6,589,355, which is assigned to the assignee of the present invention and incorporated herein by reference. For supercritical cleaning applications, is preferred in certain embodiments to include in the present cleaning compositions, in addition to the HFO-1234 (preferably HFO-1234ze), one or more additional components, such as CO 2 and other additional components known for use in connection with supercritical cleaning applications. It may also be possible and desirable in certain embodiments to use the present cleaning compositions in connection with particular vapor degreasing and solvent cleaning methods.
[0083] Flammability Reduction Methods
[0084] According to certain other preferred embodiments, the present invention provides methods for reducing the flammability of fluids, said methods comprising adding a compound or composition of the present invention to said fluid. The flammability associated with any of a wide range of otherwise flammable fluids may be reduced according to the present invention. For example, the flammability associated with fluids such as ethylene oxide, flammable hydrofluorocarbons and hydrocarbons, including: HFC-152a, 1,1,1-trifluoroethane (HFC-143a), difluoromethane (HFC-32), propane, hexane, octane, and the like can be reduced according to the present invention. For the purposes of the present invention, a flammable fluid may be any fluid exhibiting flammability ranges in air as measured via any standard conventional test method, such as ASTM E-681, and the like.
[0085] Any suitable amounts of the present compounds or compositions may be added to reduce flammability of a fluid according to the present invention. As will be recognized by those of skill in the art, the amount added will depend, at least in part, on the degree to which the subject fluid is flammable and the degree to which it is desired to reduce the flammability thereof. In certain preferred embodiments, the amount of compound or composition added to the flammable fluid is effective to render the resulting fluid substantially non-flammable.
[0086] Flame Suppression Methods
[0087] The present invention further provides methods of suppressing a flame, said methods comprising contacting a flame with a fluid comprising a compound or composition of the present invention. Any suitable methods for contacting the flame with the present composition may be used. For example, a composition of the present invention may be sprayed, poured, and the like onto the flame, or at least a portion of the flame may be immersed in the composition. In light of the teachings herein, those of skill in the art will be readily able to adapt a variety of conventional apparatus and methods of flame suppression for use in the present invention.
[0088] Sterilization Methods
[0089] Many articles, devices and materials, particularly for use in the medical field, must be sterilized prior to use for the health and safety reasons, such as the health and safety of patients and hospital staff. The present invention provides methods of sterilizing comprising contacting the articles, devices or material to be sterilized with a compound or composition of the present invention comprising a compound of Formula I, preferably HFO-1234, and even more preferably HFO-1234ze, in combination with one or more sterilizing agents. While many sterilizing agents are known in the art and are considered to be adaptable for use in connection with the present invention, in certain preferred embodiments sterilizing agent comprises ethylene oxide, formaldehyde, hydrogen peroxide, chlorine dioxide, ozone and combinations of these. In certain embodiments, ethylene oxide is the preferred sterilizing agent. Those skilled in the art, in view of the teachings contained herein, will be able to readily determine the relative proportions of sterilizing agent and the present compound(s) to be used in connection with the present sterilizing compositions and methods, and all such ranges are within the broad scope hereof. As is known to those skilled in the art, certain sterilizing agents, such as ethylene oxide, are relatively flammable components, and the compound(s) in accordance with the present invention are included in the present compositions in amounts effective, together with other components present in the composition, to reduce the flammability of the sterilizing composition to acceptable levels.
[0090] The sterilization methods of the present invention may be either high or low-temperature sterilization of the present invention involves the use of a compound or composition of the present invention at a temperature of from about 250° F. to about 270° F., preferably in a substantially sealed chamber. The process can be completed usually in less than about 2 hours. However, some articles, such as plastic articles and electrical components, cannot withstand such high temperatures and require low-temperature sterilization. In low temperature sterilization methods, the article to be sterilized is exposed to a fluid comprising a composition of the present invention at a temperature of from about room temperature to about 200° F., more preferably at a temperature of from about room temperature to about 100° F.
[0091] The low-temperature sterilization of the present invention is preferably at least a two-step process performed in a substantially sealed, preferably air tight, chamber. In the first step (the sterilization step), the articles having been cleaned and wrapped in gas permeable bags are placed in the chamber. Air is then evacuated from the chamber by pulling a vacuum and perhaps by displacing the air with steam. In certain embodiments, it is preferable to inject steam into the chamber to achieve a relative humidity that ranges preferably from about 30% to about 70%. Such humidities may maximize the sterilizing effectiveness of the sterilant, which is introduced into the chamber after the desired relative humidity is achieved. After a period of time sufficient for the sterilant to permeate the wrapping and reach the interstices of the article, the sterilant and steam are evacuated from the chamber.
[0092] In the preferred second step of the process (the aeration step), the articles are aerated to remove sterilant residues. Removing such residues is particularly important in the case of toxic sterilants, although it is optional in those cases in which the substantially non-toxic compounds of the present invention are used. Typical aeration processes include air washes, continuous aeration, and a combination of the two. An air wash is a batch process and usually comprises evacuating the chamber for a relatively short period, for example, 12 minutes, and then introducing air at atmospheric pressure or higher into the chamber. This cycle is repeated any number of times until the desired removal of sterilant is achieved. Continuous aeration typically involves introducing air through an inlet at one side of the chamber and then drawing it out through an outlet on the other side of the chamber by applying a slight vacuum to the outlet. Frequently, the two approaches are combined. For example, a common approach involves performing air washes and then an aeration cycle.
EXAMPLES
[0093] The following examples are provided for the purpose of illustrating the present invention but without limiting the scope thereof.
Example 1
[0094] The coefficient of performance (COP) is a universally accepted measure of refrigerant performance, especially useful in representing the relative thermodynamic efficiency of a refrigerant in a specific heating or cooling cycle involving evaporation or condensation of the refrigerant. In refrigeration engineering, this term expresses the ratio of useful refrigeration to the energy applied by the compressor in compressing the vapor. The capacity of a refrigerant represents the amount of cooling or heating it provides and provides some measure of the capability of a compressor to pump quantities of heat for a given volumetric flow rate of refrigerant. In other words, given a specific compressor, a refrigerant with a higher capacity will deliver more cooling or heating power. One means for estimating COP of a refrigerant at specific operating conditions is from the thermodynamic properties of the refrigerant using standard refrigeration cycle analysis techniques (see for example, R. C. Downing, FLUOROCARBON REFRIGERANTS HANDBOOK, Chapter 3, Prentice-Hall, 1988).
[0095] A refrigeration/air conditioning cycle system is provided where the condenser temperature is about 150° F. and the evaporator temperature is about −35° F. under nominally isentropic compression with a compressor inlet temperature of about 50° F. COP is determined for several compositions of the present invention over a range of condenser and evaporator temperatures and reported in Table I below, based upon HFC-134a having a COP value of 1.00, a capacity value of 1.00 and a discharge temperature of 175° F.
[0000]
TABLE I
DISCHARGE
REFRIGERANT
Relative
TEMPERATURE
COMPOSITION
Relative COP
CAPACITY
(° F.)
HFO 1225ye
1.02
0.76
158
HFO trans-1234ze
1.04
0.70
165
HFO cis-1234ze
1.13
0.36
155
HFO 1234yf
0.98
1.10
168
[0096] This example shows that certain of the preferred compounds for use with the present compositions each have a better energy efficiency than HFC-134a (1.02, 1.04 and 1.13 compared to 1.00) and the compressor using the present refrigerant compositions will produce discharge temperatures (158, 165 and 155 compared to 175), which is advantageous since such result will likely leading to reduced maintenance problems.
Example 2
[0097] The miscibility of HFO-1225ye and HFO-1234ze with various refrigeration lubricants is tested. The lubricants tested are mineral oil (C3), alkyl benzene (Zerol 150), ester oil (Mobil EAL 22 cc and Solest 120), polyalkylene glycol (PAG) oil (Goodwrench Refrigeration Oil for 134a systems), and a poly(alpha-olefin) oil (CP-6005-100). For each refrigerant/oil combination, three compositions are tested, namely 5, 20 and 50 weight percent of lubricant, with the balance of each being the compound of the present invention being tested
[0098] The lubricant compositions are placed in heavy-walled glass tubes. The tubes are evacuated, the refrigerant compound in accordance with the present invention is added, and the tubes are then sealed. The tubes are then put into an air bath environmental chamber, the temperature of which is varied from about −50° C. to 70° C. At roughly 10° C. intervals, visual observations of the tube contents are made for the existence of one or more liquid phases. In a case where more than one liquid phase is observed, the mixture is reported to be immiscible. In a case where there is only one liquid phase observed, the mixture is reported to be miscible. In those cases where two liquid phases were observed, but with one of the liquid phases occupying only a very small volume, the mixture is reported to be partially miscible.
[0099] The polyalkylene glycol and ester oil lubricants were judged to be miscible in all tested proportions over the entire temperature range, except that for the HFO-1225ye mixtures with polyalkylene glycol, the refrigerant mixture was found to be immiscible over the temperature range of −50° C. to −30° C. and to be partially miscible over from −20 to 50° C. At 50 weight percent concentration of the PAG in refrigerant and at 60°, the refrigerant/PAG mixture was miscible. At 70° C., it was miscible from 5 weight percent lubricant in refrigerant to 50 weight percent lubricant in refrigerant.
Example 3
[0100] The compatibility of the refrigerant compounds and compositions of the present invention with PAG lubricating oils while in contact with metals used in refrigeration and air conditioning systems is tested at 350° C., representing conditions much more severe than are found in many refrigeration and air conditioning applications.
[0101] Aluminum, copper and steel coupons are added to heavy walled glass tubes. Two grams of oil are added to the tubes. The tubes are then evacuated and one gram of refrigerant is added. The tubes are put into an oven at 350° F. for one week and visual observations are made. At the end of the exposure period, the tubes are removed.
[0102] This procedure was done for the following combinations of oil and the compound of the present invention:
[0103] a) HFO-1234ze and GM Goodwrench PAG oil
[0104] b) HFO1243 zf and GM Goodwrench oil PAG oil
[0105] c) HFO-1234ze and MOPAR-56 PAG oil
[0106] d) HFO-1243 zf and MOPAR-56 PAG oil
[0107] e) HFO-1225 ye and MOPAR-56 PAG oil.
[0108] In all cases, there is minimal change in the appearance of the contents of the tube. This indicates that the refrigerant compounds and compositions of the present invention are stable in contact with aluminum, steel and copper found in refrigeration and air conditioning systems, and the types of lubricating oils that are likely to be included in such compositions or used with such compositions in these types of systems.
Comparative Example
[0109] Aluminum, copper and steel coupons are added to a heavy walled glass tube with mineral oil and CFC-12 and heated for one week at 350° C., as in Example 3. At the end of the exposure period, the tube is removed and visual observations are made. The liquid contents are observed to turn black, indicating there is severe decomposition of the contents of the tube.
[0110] CFC-12 and mineral oil have heretofore been the combination of choice in many refrigerant systems and methods. Thus, the refrigerant compounds and compositions of the present invention possess significantly better stability with many commonly used lubricating oils than the widely used prior art refrigerant-lubricating oil combination.
Example 4
Polyol Foam
[0111] This example illustrates the use of blowing agent in accordance with one of the preferred embodiments of the present invention, namely the use of HFO-1234ze, and the production of polyol foams in accordance with the present invention. The components of a polyol foam formulation are prepared in accordance with the following table:
[0000]
PBW
Polyol Component*
Voranol 490
50
Voranol 391
50
Water
0.5
B-8462 (surfactant)
2.0
Polycat 8
0.3
Polycat 41
3.0
HFO-1234ze
35
Total
140.8
Isocyanate
M-20S
123.8 Index 1.10
*Voranol 490 is a sucrose-based polyol and Voranol 391 is a toluene diamine based polyol, and each are from Dow Chemical. B-8462 is a surfactant available from Degussa-Goldschmidt. Polycat catalysts are tertiary amine based and are available from Air Products. Isocyanate M-20S is a product of Bayer LLC.
[0112] The foam is prepared by first mixing the ingredients thereof, but without the addition of blowing agent. Two Fisher-Porter tubes are each filled with about 52.6 grams of the polyol mixture (without blowing agent) and sealed and placed in a refrigerator to cool and form a slight vacuum. Using gas burets, about 17.4 grams of HFO-1234ze are added to each tube, and the tubes are then placed in an ultrasound bath in warm water and allowed to sit for 30 minutes. The solution produced is hazy, a vapor pressure measurement at room temperature indicates a vapor pressure of about 70 psig, indicating that the blowing agent is not in solution. The tubes are then placed in a freezer at 27° F. for 2 hours. The vapor pressure was again measured and found to be 14-psig. The isocyanate mixture, about 87.9 grams, is placed into a metal container and placed in a refrigerator and allowed to cool to about 50° F. The polyol tubes were then opened and weighed into a metal mixing container (about 100 grams of polyol blend are used). The isocyanate from the cooled metal container is then immediately poured into the polyol and mixed with an air mixer with double propellers at 3000 RPM's for 10 seconds. The blend immediately begins to froth with the agitation and is then poured into an 8×8×4 inch box and allowed to foam. Because of the froth, a cream time cannot be measured. The foam has a 4-minute gel time and a 5-minute tack free time. The foam is then allowed to cure for two days at room temperature.
[0000] The foam is then cut to samples suitable for measuring physical properties and is found to have a density of 2.14 pcf. K-factors are measured and found to be as follows:
[0000]
Temperature
K, BTU In/Ft 2 h ° F.
40° F.
.1464
75° F.
.1640
110°
.1808
Example 5
Polystyrene Foam
[0113] This example illustrates the use of blowing agent in accordance with two preferred embodiments of the present invention, namely the use of HFO-1234ze and HFO-1234-yf, and the production of polystyrene foam. A testing apparatus and protocol has been established as an aid to determining whether a specific blowing agent and polymer are capable of producing a foam and the quality of the foam. Ground polymer (Dow Polystyrene 685D) and blowing agent consisting essentially of HFO-1234ze are combined in a vessel. A sketch of the vessel is illustrated below. The vessel volume is 200 cm 3 and it is made from two pipe flanges and a section of 2-inch diameter schedule 40 stainless steel pipe 4 inches long (see FIG. 1). The vessel is placed in an oven, with temperature set at from about 190° F. to about 285° F., preferably for polystyrene at 265° F., and remains there until temperature equilibrium is reached.
[0114] The pressure in the vessel is then released, quickly producing a foamed polymer. The blowing agent plasticizes the polymer as it dissolves into it. The resulting density of the two foams thus produced using this method are given in Table 1 and graphed in FIG. 1 as the density of the foams produced using trans-HFO-1234ze and HFO-1234yf. The data show that foam polystyrene is obtainable in accordance with the present invention. The die temperature for R1234ze with polystyrene is about 250° F.
[0000]
TABLE 1
Dow polystyrene 685D
Foam density (lb/ft 3 )
T ° F.
transHFO-1234ze
HFO-1234yf
275
55.15
260
22.14
14.27
250
7.28
24.17
240
16.93 | Disclosed are the use of fluorine substituted olefins, including tetra- and penta-fluoropropenes, in a variety of applications, including in methods of depositing catalyst on a solid support, methods of sterilizing articles, cleaning methods and compositions, methods of applying medicaments, fire extinguishing/suppression compositions and methods, flavor formulations, fragrance formulations and inflating agents. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
The present application claims priority to U.S. provisional patent application Ser. No. 60/429,959, filed Dec. 2, 2002, entitled “Expandable and Retractable Barbed Tape Concertina Barrier for Door and Window Enclosures.”
FIELD OF INVENTION
This invention relates generally to building structures adapted to serve the purposes of a barrier. This invention relates particularly to expandable and retractable barbed barriers.
BACKGROUND
Typically, barriers, such as windows, walls, bars, fences, and doors, are used to physically block openings. Such barrier systems are inadequate because they inhibit visibility, fail to deter potential intruders, fail to retract, create a risk of inadvertent injury, and can require significant expenditures of time, money, and energy. For example, non-transparent barriers, such as walls, fail to provide visibility to the other side of the barrier. Non-cutting barriers, such as bars, fail to deter attempts at penetration because they do not create a risk of injury to a potential intruder. Non-retractable barriers, such as walls, do not retract and generally must be completely destroyed in order to remove them from a specific location. Non-separated barriers, such as barbed wire concertina, create a substantial risk of injury to parties not attempting to intrude. Furthermore, the use of shatterproof glass, security guards, and guard dogs, can require significant expenditures of time, money, and energy. As a result, a barrier system capable of increased visibility, increased deterrence, increased retractability, decreased risk of injury, and decreased use of resources, would be highly desirable.
A primary object and feature of the present invention is to provide an improved barrier system. It is a further object and feature of the present invention to provide a barrier system capable of providing visibility. Another object of the present invention to provide a system that deters potential intruders from penetrating an opening. Another object of the present invention is to provide a system capable of retracting. Other objects and features of this invention will become apparent with reference to the following descriptions.
SUMMARY OF THE INVENTION
The present invention is a barrier system utilizing cutters, which cut objects attempting to penetrate an opening. The cutters are connected into strips, and the strips are connected to form a substantially planar barrier sheet. The barrier sheet may be encased by breakable separators, which cover the cutters to prevent inadvertent injury but expose the cutters when broken upon an attempt to penetrate the barrier. The barrier may be retracted into an opening, preferably into a concealed compartment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of the barrier system according to a preferred embodiment.
FIG. 2 is a top view of a strip showing the cutters.
FIG. 3 is a front view of a partially-retracted barrier.
FIG. 4 is a front view of the barrier system installed in a door frame.
FIG. 5 is a perspective view of a portion of the barrier sandwiched between separators.
FIG. 6 is a top view of a portion of the barrier sandwiched between separators as shown in FIG. 5
FIG. 7 is a perspective view of a partially-retracted barrier.
FIG. 8 is a side view of a cutter.
FIG. 9 is a top view of a cutter with retained barbs.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1–9 , system 100 comprises cutters 102 and connectors 104 . Connectors 104 are utilized to connect cutters 102 , forming a barrier capable of blocking an opening, such as a storefront window or doorway, from penetration by various objects such as animals, people, and weapons, as shown in FIG. 4 . System 100 may also comprise a separator 106 , capable of separating cutters 102 from their surroundings, so as to prevent accidental cutting of proximately moving objects. System 100 may also comprise a retractor 108 and retraction compartment 110 , for moving cutters 102 in and out of the opening. Preferably, cutters 102 are razors that are used on razor wire. Altematively, cutters 102 can be barbs, such as those extending from barbed wire or those extending from barbed tape, as is known in the art. Under appropriate circumstances, considering issues such as cost, manufacturing, local laws, etc., cutters may be fashioned from other materials, such as sharpened strips of plastic.
The cutters are connected to form strips 207 . Preferably the cutters 102 are integral with the connectors 104 , such as the case with barbed wire or barbed tape, but the cutters may be connected by separate connectors. The preferred distance E between cutters 102 is about 4 inches, as shown in FIG. 2 .
A plurality of strips 207 is connected to each other to form an accordion-like barrier sheet. Preferably the strips 207 are connected to each other utilizing rivets 206 at spaced locations. The preferred distance B between rivets 206 is about 8 inches, as shown in FIG. 1 . Under appropriate circumstances, considering issues such as mechanical failure, cost, manufacturing, etc., bandings, tape, hooks, clips, tie-offs, or spot welds may be used to connect the strips to each other. When the sheet is expanded, the distance A between cutters 102 is preferably about 3 inches, as shown in FIG. 1 . An alternative cutter 102 , having a retainer barb 182 , is shown in FIG. 9 . This cutter is also known in the art as a detainer hook barb.
The barrier sheet is substantially planar, but has many exposed, sharp edges which may be dangerous to innocent passers-by. To prevent inadvertent injury, the barrier sheet may be separated from its surrounding by a breakable protective sheet. The sheet prevents inadvertent injury when whole, but exposes the cutters when broken. Preferably, separator 106 comprises two planar sheets of material which sandwich the cutters 102 , on both sides, as shown in FIG. 5 and FIG. 6 . A separator 106 facing only one side of the cutters 102 may also be used. Preferably, separator 106 is a transparent or porous material, so as to provide for visibility through the barrier. Preferably, separator 106 is made of glass panes 210 . Under appropriate circumstances, considering issues such as cost, manufacturing, security, visibility, etc., other separators 106 , such as plastic panes, drywall, bricks, bulletproof materials, etc., may suffice.
FIG. 2 is a top view of a cutter. Preferably, system 100 comprises a distance C of about 1 inch, a distance D of about 0.5 inches, a distance E of about 4 inches, and a distance F of about 2.5625 inches. Preferably, the two tips 209 of barb 208 , as shown in FIG. 2 , are bent at an angle δ of 10 degrees outside the plane of the strip, in opposite directions on the same barb, as shown most clearly in FIG. 8 . Alternatively, system 100 may comprise a distance G of about 0.75 inches, a distance H of about 0.25 inches, a distance I of about 1.5 inches, and a distance J of about 0.9375 inches, as shown in FIG. 2 . Preferably, the base of the tips 209 have cut-outs 212 that narrow at the barb roots.
FIG. 3 is a front view of a partially-retracted barrier. The retractor 108 is any mechanism capable of pulling cutters 102 in and out of the opening. Preferably, retractor 108 retracts into a hollow compartment 110 , as shown in FIG. 3 . The barrier may retract into the compartment in its expanded form, or it may be compressed to fit into a smaller compartment. Preferably, retractor 108 is a manual retraction system, whereby a user slides the barrier into compartment 110 , utilizing handle 109 , which compresses the strips 207 of cutters 102 upon themselves, like an accordion, as shown in FIG. 7 . Preferably, a gap 220 exists between the side edges of the cutters 102 , and the side edges of the opening, in order to account for expansion as the cutters 102 compress into a retracted position. Under appropriate circumstances, considering issues such as space surrounding the opening, cost, manufacturing, etc., other retractors 108 , such as automated pulling, automated pushing, single removable cutter sheets, etc., may suffice.
Although the above descriptions provide applicant's preferred embodiments of this invention, it will be understood that the broadest scope of this invention includes such modifications as diverse shapes and sizes, as well as diverse materials and colors. In addition, equivalents may be substituted for elements thereof without departing from the true scope of the invention. Such scope is limited only by the below claims as read in connection with the above specification. Furthermore, many other advantages of applicant's invention will be apparent, to persons of ordinary skill in the art, as a result of the above descriptions and as a result of the below claims. | A barrier system utilizing cutters that have been connected into strips, with the strips connected to form a substantially planar barrier sheet. The barrier sheet may be encased by breakable separators, which cover the cutters to prevent inadvertent injury but expose the cutters when broken upon an attempt to penetrate the barrier. The barrier may be retracted into an opening, preferably into a concealed compartment. | 4 |
FIELD AND BACKGROUND OF THE INVENTION
This invention relates in general to the construction of sewing units and, in particular, to a new and useful automatic feed sewing machine unit which includes a device for cutting-open tucks on cut pieces of garment.
DESCRIPTION OF THE PRIOR ART
In a known device for sewing and cutting-open tucks, the fabric layers which are folded along a predetermined line of the cut piece are conveyed into a U-shaped guide having a web formed with a longitudinal slot for a circular knife rotating in a horizontal plane between the fabric layers of the tuck by which, during the sewing operation, the tuck is cut open along its fold edge while the fabric layers are backed on the outside against yielding by the free legs of the guide.
This method leads to satisfactory results in the working of relatively stiff materials. However, it is not suitable for thin and loosely woven fabric, since due to its small inherent stiffness, such a fabric is pushed off the circular path of the cutting edge by the knife and, consequently, cannot be cut open along the predetermined cutting line. Also, in the known device, if cut pieces of materials, having unequal thicknesses are to be worked sequentially, the unchangeable vertical position of the U-shaped guide and the equally unchangeable circular path of the cutting knife have a particularly unfavorable effect.
SUMMARY OF THE INVENTION
The inventive innovation provides an improved guide device for the fold edge of tucks ensuring a secure guidance of the fold edge of the tuck for a completely satisfactory operation of the cutting knife independently of the thickness and nature of the material to be worked and securely preventing a yielding relative to the cutting knife.
In accordance with the invention, the work advance table is formed in the marginal zone of one of its edges, at least partly, with a forked cross-section for introducing and guiding a guide spur for the fold edge of the tuck, which is introduceable between the fabric layers of the folded work. A space saving arrangement is obtained by a pivotal mounting of the guide spur on the drive shaft of the cutting knife. The cutting result is further improved by the provision that, in accordance with a development of the invention, the guide spur forms the counterblade for the cutting knife.
To facilitate the change of the cutting knife and to enable the entire device, when not used, to be brought into a non-operative position in a simple manner, the support of the cutting knife is adapted to accommodate the driving means of the knife and is mounted for pivotal movement about both a horizontal and a vertical axis.
The manufacture of the work advance table advantageously provides that the forked cross-section is formed on an insert which is secured to the advance table.
Accordingly, it is an object of the invention to provide an improved device for guiding fabric into association with a reciprocating needle in a sewing machine for effecting the cutting of a defined pattern of seam stitch and for simultaneously guiding a cutting knife along the folded edge of the work piece material and which includes a spur which enters into the fold between the material and has a slot therein for accommodating a rotating knife therein which is advanced with the spur.
A further object of the invention is to provide a device for cutting into material which has been folded along the fold line and which comprises a carrier plate which is pivotally mounted on a table, for example, in a sewing machine unit, and which includes a rotatable blade which is driven by a motor carried on the carrier plate and wherein the rotating blade is covered around at least a portion of the periphery by a guide spur which has a pointed end for engagement between the fabric material and a trailing slotted end through which the knife extends and which is guided between the adjacent legs of the spur during the cutting operation.
A further object of the invention is to provide a sewing machine unit which includes an advancing work table having an edge with a slot therein around which the material to be worked upon is folded so as to accommodate a spur and a cutting knife which may be advanced along the seam to cut the seam when the work table is advanced relatively thereto.
A further object of the invention is to provide a sewing machine unit and a device for cutting edge seams of material which are simple in design, rugged in construction and economical to manufacture.
For an understanding of the principles of the invention, reference is made to the following description of a typical embodiment thereof as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the Drawings:
FIG. 1 is a simplified front elevational view of a sewing unit having a device for sewing and cutting-open tucks on cut pieces of garments constructed in accordance with the invention;
FIG. 2 is a partial top plan view of the machine shown in FIG. 1 showing the support for the cutting tool and the guide spur and drive therefor;
FIG. 3 is an elevational view, partly in section, taken in the direction of the arrow A in FIG. 2;
FIG. 4 is an elongated view of the cutting knife and spur guide;
FIG. 5 is an enlarged sectional view taken along the line V--V of FIG. 1, but without the cutting mechanism being shown;
FIG. 6 is an enlarged partial perspective view of the guide spur in its operational position during cutting; and
FIG. 7 is a partial top plan view with a tuck made with the device in accordance with the invention in a state after flat ironing.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings in particular, the invention embodied therein, comprises a sewing unit having a device for sewing and cutting-open tucks on cut pieces of garments. The sewing unit serving to illustrate the use of a device in accordance with the invention comprises a frame 1 and a table plate 2. A sewing machine 3, including a work supporting bed 4, is mounted in an opening of the table plate 2. The needle bar 6 which is reciprocable up and down in a well-known manner is mounted in the head of the sewing machine. On its lower end, needle bar 6 carries a needle 7 which cooperates in the usual manner with a shuttle (not shown) to form double back or chain-stitches. A sewing machine drive motor 8 is mounted on frame 1 and is connected to the sewing machine 3 by means of a drive belt 9.
The sewing machine is not provided with its own feed mechanism. To displace the work fabric W, a known feed mechanism is provided which includes two longitudinal guide bars 10, 11 extending parallel to each other and which are secured to frame 1 below table plate 2 and a slide 14 driven by a chain 13 off a motor 12 is guided thereon. Two transverse guide bars 15 and 16, extending parallel to each other, are secured to the slide 14, and a support 17 is displaceably mounted thereon. Thus, support 17 is guided in the manner of a cross-slide. U-shaped arms 18 having legs of unequal length are secured to the two ends of support 17. The short legs of the two arms 18 are connected to support 17 while the long legs extend parallel to the longitudinal axis of sewing machine 3, above table plate 2 and are spaced therefrom. Pneumatic motors 19 and 20 are mounted on the respective free ends of the long legs of arms 18. A template rail 23 is disconnectably secured to respective piston rods 21 and 22 of two pneumatic motors 19 and 20. Template rail 23 comprises a pressure strip 24 which is provided, on its underside, with a soft drive coating to be placed on the fabric, and a guide blade 25. As shown in FIG. 2, guide blade 25 is conformable to the desired seam line S or to the shape of the tuck.
A vertical supporting rod 26, mounted in head 5 of the sewing machine 3, as shown in FIGS. 1 and 5, carries a plate 27 on its lower end having two template rail guide rollers 30, 31, each rotatable about a vertical axes 28 and 29. The guide blade 25 passes between rollers 30, 31 as template rail 23 is displaced.
An advance table 32 serves as a surface on which the work W is placed. The work is folded along the fold line predetermined for the tuck, and is advanced over the advance table 32. Advance table 32 comprises a table plate 33 extending in a plane parallel to the work receiving surface and between the work receiving surface and the pressure strip 24 of the template rail 23. An insert 35 is secured, for example, by soldering, at the edge 34 of a table plate 33 of advance table 32 which is near the template rail 23. At the left front side 36 of insert 35 (FIG. 2), edge 34 of advance table 32 is slightly offset and extends obliquely to the side edge of table plate 33.
As shown in FIGS. 3 and 4, in the zone adjacent its front side 36 (FIG. 2), insert 35 is provided with a recess 37 so that it comprises a forked portion which is open toward template rail 23 and toward front side 36.
Two supports 38 and 39 are provided on the underside of table plate 33, and sliding rods 40 and 41 are secured to each of them, respectively. Sliding rods 40, 41 are each guided in a respective guide block 42, 43 secured to the underside of table plate 2 and displaceable parallel to the latter in the direction of the arrow Z, in FIG. 2.
As shown in FIG. 2, the device for cutting open the doubled work W along the fold or break line while making the tuck comprises a base plate 44 which is secured to work supporting bed 4 of sewing machine 3 by means of screws 46 passed through longitudinal slots 45, as shown in FIGS. 2 and 3. A pivot 47 is fixed in base plate 44 and a supporting plate 48 is pivotally mounted thereon and secured against axial displacement by a clamping disc 49, see FIG. 3. A carrier plate 51 is pivotally mounted on supporting plate 48 by means of a horizontal hinge pin 50 and a shaft 52 is mounted on the free end of carrier plate 51. A cutting knife 53 designed as a multi-edge blade is secured to the threaded lower end of shaft 52 by means of two nuts 54. A bushing 55 is rotatably mounted on shaft 52 below carrier plate 51. Shaft 52, with bushing 55, is axially secured by two setting rings 56. Gear 57 is mounted on the upper end of shaft 52. A drive motor 58 drives shaft 52 and cutting knife 53 and it is secured to carrier plate 51 by means of four angles or supports 59. Shaft 52 of cutting knife 53 is driven through a gear belt 62 from a drive gear 61 mounted on shaft 60 of motor 58.
To adjust the distance of cutting knife 53 from the work supporting surface, a stop screw 64 is provided in carrier plate 51 which is adjustable by means of a lock nut 63.
A guide spur 65 is secured to bushing 55 which is rotatably mounted on shaft 52. Guide spur 65 comprises a vertical shaft portion 66 and a wedge-shape spur portion 67 extending at an angle thereto. The guide spur includes a top edge 65a and a bottom edge 65b formed with a tip projecting against the work in the feed direction, which is indicated by arrow V. To receive the cutting knife 53, spur portion 67 has a slot 68 between top and bottom edges 65a and 65b at the side remote from the tip. Thereby, guide spur 65 forms a counterblade for cutting knife 53. For vertical adjustment of guide spur 65, its fixing screw 69 is passed through a longitudinal slot 70 provided in shaft 66.
The pivotal movement of guide spur 65, the spur portion 67 of which is to be swung between the fabric layers of work W folded around edge 34 of table plate 33 into recess 37 of insert 35, is effected by means of an actuating arm 71, (FIGS. 2 and 4), which is secured to bushing 55 and pivotally connected by a screw 75 to an angle piece 74 which is fixed to the piston rod 72 of a single-action pneumatic motor 73. Pneumatic motor 73 includes a connection 76 and is mounted unilaterally and pivotally on a pillow block 77, FIG. 2, which, in turn, is fixed to carrier plate 51. Piston rod 72 is loaded by a return spring 78 mounted thereon.
As seen in FIG. 2, a fixing flange 79, extending at an angle, is provided on base plate 44, and a single-action pneumatic motor 80 is mounted thereon for swinging carrier plate 51 with the parts arranged thereon about pivot 47. Pneumatic motor 80 comprises a connection 81, a piston rod 82 and a pressure piece 83 which is secured to piston rod 82 and acts on a pressure plate 85 which is fixed to the underside of carrier plate 51 by means of screws 84. Pressure plate 85 of carrier plate 51 is brought into contact with pressure piece 83 by means of a tension spring 86 which is attached on the one side to a stud 87 fixed to carrier plate 51 and, on the other side, by means of two nuts 88, to a stud 89 which is fixed to fixing flange 79.
To limit the pivotal movement of carrier plate 51 and to determine the depth of penetration of cutting knife 53 between the fabric layers of work W, a stop screw 90 is provided which cooperates with pressure piece 85. Stop 90 is screwed into a web 91 of base plate 44 and is adjustable by means of a nut 92.
As usual, pneumatic motors 19, 20, 73 and 80 are connected by flexible tubings to a compressed-air source (not shown) and are advantageously controlled by electromagnetically switchable valves. The valves, as well as sewing machine motor 8, feed motor 12 and motor 58 driving the cutting mechanism, may be controlled either manually or according to a predetermined program. The choice and arrangement of the valves, as well as the design of the control, is the same as conventionally used in such machines and therefore they are not illustrated.
Assuming that motors 8, 12 and 58 are switched off, the partial mechanisms are in their respective initial or rest positions in which table 32 and carrier plate 51 with cutting knife 53 and guide spur 65 occupy the positions indicated in FIG. 2 by dash-dotted lines and template rail 23 is lifted by the pneumatic motors 19 and 20, the device operates as follows: Work W, for example a jacket breastpiece, to be provided with a tuck shown for example in FIG. 7, is folded along the later cutting line of the tuck which, in general, is indicated by a marking line around front edge 34 of table plate 33 of advance table 32 and around recess 37 and, by means of advance table 32, it is passed below the lifted pressure strip 24 of template rail 23 into the position indicated in FIG. 2 in solid lines. Thereupon, template rail 23 is lowered on work W while leaving a free margin depending on the shape of the seam, whereby work W is engaged by friction contact.
Due to a corresponding switching arrangement, after actuating the switches of pneumatic motors 73 and 80, compressed air is supplied through their connections 76 and 81, whereby piston rod 72 of pneumatic motor 73 is displaced against the action of return spring 78 and bushing 55 with guide spur 65 is swung clockwise about shaft 52 so that spur portion 67 of guide spur 65 occupies the position shown in FIG. 2 in dash-dotted lines. Further, by piston rod 82 of pneumatic motor 80 and pressure piece 83 fixed thereon, and acting on pressure plate 85, carrier plate 51 is swung toward work W into the solid line positions shown in FIG. 2. Simultaneously, with a switching operation to clear the compressed air supply to pneumatic motors 73 and 80, drive motor 58 of cutting knife 53 is switched on and drives the cutting knife mounted on shaft 52 through gear 61, gear belt 62 and gear 57.
As soon as carrier plate 51 has reached its working position which is determined and adjustable by stop screw 90 and pressure plate 85, the compressed-air supply to pneumatic motor 73 is interrupted and the cylinder of pneumatic motor 73 is vented. Consequently, return spring 78 becomes effective. Under its action, piston rod 72 is pushed back into its initial position and, through actuating arm 71, bushing 55 with guide spur 65 is swung counterclockwise about shaft 52. At this swinging motion, the wedge-shaped spur portion 67 of guide spur 65 penetrates into recess 37 of insert 35 and thus between the two fabric layers of work W which has been folded around front edge 34 of advance table 32 and insert 35. The spur 65 is urged by return spring 78 from the inside of the folded fabric layers of work W against the fold edge of work W which, during the subsequent cutting operation, is thereby held slightly stretched relative to cutting knife 53. Advance table 32 is then moved back into its initial position, indicated in FIG. 2 in dash-dotted lines. To prevent an unintentional slipping of work W, retaining or pressure fingers (not shown) may be used to temporarily clamp the free margin of work W. Thereupon, by actuating a switch, first motor 12 is put into operation by which, through chain 13, slide 14 with support 17 and thereby, through arms 18, template rail 23 with frictionally engaged work W is displaced from the initial position according to FIGS. 1 and 2 in the direction of arrow V (FIG. 2).
During this displacement, work W is cut open along the fold or break edge except for the distance a, i.e., the part adjacent the point of the tuck which, for reasons of durability of the seam, is not cut open. During this operation, the guide spur 65 forms the counterblade or a countersupport for the cutting knife projecting into slot 68 in spur portion 67. A yielding of even very loosely woven or very thin, pliable fabrics relative to cutting knife 53 is thereby completely eliminated.
Shortly before the edge of work W aligned with lateral edge 36 of insert 35 has reached the stitch formation zone, motor 8 of driving sewing machine 3 through belt 9 is switched on, either by a key switch provided in the displacement path of work W or by photoelectric means. During this further displacement, the tuck seam, whose shape is determined by guide blade 25 of template rail 23 passing between guide rollers 30, 31, which are mounted on the sewing machine, is formed along the dash-dotted line S (FIG. 2). By a corresponding control of feed motor 12, the seam may be locked at both its ends by condensing the stitches or by a temporary reversal of the shifting direction.
During the displacement of template rail 23 with work W from the right-hand to the left-hand side (FIG. 2), the doubled work W is cut open along the fold or break edge, except for the distance a (FIG. 7) and the tuck seam is formed along line S.
To finish the cutting operation, automatically operating solenoid valves (not shown) are controlled, through appropriately arranged limiting switches (not shown) so as to supply pneumatic motor 73 with compressed air through connection 76 and with a short delay, for example, through a timing circuit, to interrupt the compressed-air supply to pneumatic motor 80, and drive motor 58 and, thereby, cutting knife 53 are switched off. The result is that, at the end of the cut, guide spur 65, which is fixed to bushing 55, is swung clockwise through actuating arm 71 so that the wedge-shaped spur portion 67 is withdrawn from its position between the fabric layers of work W and carrier plate 51 with the parts arranged thereon, under the action of tension spring 86, and they are swung back about pivot 47 into its initial position in which cutting knife 53 and guide spur 65 occupy the dash-dotted position shown in FIG. 2.
After completion of the seam along line S (FIG. 2), motors 8 and 12 are switched off, for example, by means of a limiting switch, provided in the displacement path of slide 14 and a corresponding circuit. Thereupon, template rail 23 is lifted from work W by a corresponding supply of compressed air to pneumatic motors 19, 20. Work W can then be removed and template rail 23 may be brought into its initial position, shown in FIGS. 1 and 2, by a corresponding switching on of feed motor 12 and the following work W to be treated which, in the meantime, has been folded along the fold edge to be subsequently cut open and around edge 34 of advance table 32, and is passed with the advance table below the lifted pressure strip 24 of template rail 23 into the position shown in FIG. 2 in solid lines. The cycle is then repeated.
It should also be noted that when not in use, the cutting mechanism can be brought into an idle position. To this end, only tension spring 86 is to be disconnected from stud 87. The entire device is then swung away about pivot 47. If necessary, carrier plate 51 with the parts arranged thereon may be swung up about hinge pin 50.
While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles. | A device for use on a sewing unit in sewing and cutting-open tucks on cut pieces of garments, comprises a sewing machine having a stitch formation zone which operates in conjunction with a work advance table. The work advance table has an edge around which the work is folded and a template rail is supported from the support for the work table and includes a pressure plate portion which may be moved into association with the work and a template rail which provides a guide for the feeding of the work piece into association with the sewing needle so that the shape of the seam may be followed. The apparatus includes a cutting knife which is carried on a carrier plate which is pivotable backwardly and forwardly. The cutting knife comprises a rotatable cutting blade which is rotated by a motor on the pivotal carrier plate. The carrier plate also provides a pivotal support for a guide spur which is in the form of a wedge-shaped plate which has a slot therein through which the blade extends and which includes an outer knife-like edge which engages into the space between the two materials. For this purpose, the work advance table is formed at least partly with a forked cross-section having spaced apart top and bottom legs defining a slot therebetween or an opening for the introduction of the guide spur so that the cutter is guided along the edge of the fabric to effect its cutting operation. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to downhole guide members employed in subterranean boreholes, typically drilled for oil and gas wells. More particularly, the invention relates to a downhole casing guide member comprising a uniquely contoured structure which guides multiple casing strings downhole and maintains such multiple casing strings in substantially fixed, side-by-side relationship with one another downhole within a conductor casing. The contour of the structure maximizes available cross sectional fluid flow area in a conductor casing, in a plane perpendicular to the center longitudinal axis of the conductor casing, to minimize fluid pressure losses when flowing fluids such as drilling fluids or cement slurries around the structure. Moreover, the contour of such structure, in the plane perpendicular to the longitudinal axis of the conductor casing, maximizes the diameter of the casing strings which may be run within a given conductor casing diameter by forming two bores, spaced substantially 180° apart, where a portion of each bore is formed by a portion of the inner wall of the conductor casing. Additionally, the contour of the structure presents tapered upper and lower shoulders which ease insertion into and removal from the conductor casing.
2. General Background
In the development of certain oil and gas fields, it is at times highly desirable to drill multiple, directionally drilled wellbores from a common surface location inside a single large "conductor casing" string. This is especially so in certain offshore oil and gas developments. In the following description, the term "conductor casing" refers generally to the initial, generally large diameter casing string installed, through which multiple wells may be drilled. Conductor casing is typically driven, drilled, or jetted into place so that the lowermost end (the "shoe") is several hundred feet below the mudline.
After the conductor casing is in place, individual wellbores are drilled and the initial casing string of each individual well is run and cemented in place. In this description, the initial casing string for each individual well is referred to as "surface casing ". Although the process and present invention are described in terms of two surface casing strings run within a conductor casing, it is understood that the invention is not limited to arrangements comprising two surface casing strings and in fact comprises different numbers of surface casing strings. Typical arrangements employ two 13-3/8" surface casing strings run substantially side-by-side within a 36" conductor casing, although other combinations of conductor and surface casing diameters may be used and are within the scope of the present invention.
A typical sequence of operations is as follows: a 36" conductor string is driven into the earth so that the casing shoe is several hundred feet below the mudline, or ocean floor. As water depths may be several hundred feet, the total length of conductor casing may be on the order of 1000'. A large diameter drill bit, typically approaching the inner diameter of the conductor casing, is then used to drill out the conductor casing to a depth slightly beyond the conductor casing shoe. Thereafter, a sequence of installation of a downhole casing guide member in the conductor casing, drilling of surface casing holes, and running and cementing of two surface casing strings follows. The operations may vary depending upon the type of guide member used. Drilling, formation evaluation, running of additional casing strings, etc., in each borehole, then proceeds in generally conventional manner through each surface casing string.
It is important for the two surface casing strings to be held downhole in fixed, side-by-side spacing with respect to one another, and the downhole casing guide members serve this purpose. Fluid flow past the downhole casing guide members is necessary for passage of drilling fluids (commonly called "mud") and cement slurries during the drilling of the surface holes and the running and cementing of the surface casing strings. It is desirable, then, that the downhole casing guide member retain the surface casing strings in fixed side-by-side position while permitting use of the largest possible surface casing strings within a given conductor casing, and while occupying as little as possible of the available cross sectional fluid flow area within the conductor casing, thereby preserving relatively uninhibited fluid flow past the guide member. Further, as the guide member must be run into (and at times retrieved from) the conductor casing, a profile which minimizes "hanging up" on ledges, obstructions and the like is desired.
One such structure is described in U.S. Pat. No. 5,560,435, to Sharp, entitled "Method and Apparatus for Drilling Multiple Offshore Wells from Within a Single Conductor String." The invention, by Sharp, discloses a method of drilling multiple wells in a conductor casing string. The invention, by Sharp, uses a downhole drilling guide which is a cylindrical member having two opposing flat, planar surfaces, and includes multiple guide bores in a side-by-side, parallel alignment, for receiving a casing string in each guide bore. The guide member is installed by running it downhole on one surface casing string (secured on a releasable connector) until the guide member rests on an internal shoulder in the conductor casing. Surface casing strings are then run through the guide bores. The configuration of the guide member of Sharp results in little available flow area in the conductor casing when the guide member and surface casing strings are in place. Use of only a single guide member as taught by Sharp may make it difficult to properly guide the second surface casing string through the guide bore. In addition, the relatively abrupt shoulders of the Sharp apparatus would tend to "hang up" on ledges, obstructions and the like within the conductor casing string.
Another such structure is described in U.S. Pat. No. 5,458,199, to Collins et al., entitled "Assembly and Process for Drilling and Completing Multiple Wells." The invention, by Collins et al., uses a downhole tie-back assembly to maintain the casing strings separated while downhole. The downhole tie-back assembly comprises bores for running the casing strings therethrough. In one embodiment, a first casing string is is threaded into screw threads in the first bore, and the first casing string is used to lower the tie-back assembly into place. A collet latch is attached to the exterior of the second casing string, and that collet latch snaps into a mating profile in the second bore, thus connecting the second casing string to the tie-back assembly. Relatively little flow area remains in the conductor casing with installation of the tie-back assembly and the two casing strings. Additionally, the maximum size of casing strings that may be run within the conductor casing is reduced due to the tie-back assembly bores completely encompassing the casing strings, and the relatively abrupt shoulders of the Collins et al assembly may result in hang-ups on interior ledges, etc. in the conductor casing during running.
As can be appreciated, the known downhole casing guide member structure and tie-back assemblies require at least one of the surface casing strings to be latched or secured to the downhole guide member and tie-back assembly to lower such downhole guide member downhole. In effect, one of the surface casing strings serves as the "running string" for the downhole guide member. Moreover, once both casing strings are installed in the downhole guide members of known design, the remaining fluid flow area around the downhole guide member and/or tie-back assembly and the first and second surface casing strings is insufficient for easy flow of displaced drilling fluids and/or cement slurries around the downhole guide member and/or tie-back assembly. Although the maximum diameter of casing strings that may be run within a conductor is (in the case of two casing strings) fundamentally limited to one-half of the inner diameter of the conductor, with the downhole casing guide members of known design the maximum outer diameter of the two casing strings is further limited by the bores in the downhole guide member being completely contained within the diameter of the downhole guide member. The abrupt upper and lower shoulders on the downhole guide members of known design do not permit easy passage past ledges or obstructions in the conductor casing.
SUMMARY OF THE PRESENT INVENTION
The preferred embodiment of the apparatus of the present invention solves the aforementioned problems in a straight forward and simple manner. In the preferred embodiment, the present invention comprises a downhole casing guide member comprising a uniquely contoured structure which:
guides two surface casing strings downhole and maintains such two surface casing strings in substantially fixed, side-by-side spaced relation in the conductor casing;
has a contour which maximizes the available fluid flow area, after installation of the downhole guide member and casing strings, in a plane perpendicular to the center axis of the conductor casing;
has a contour, in a plane perpendicular to the center axis of the conductor casing, which maximizes the outer diameter of the surface casing strings which may be run downhole within a given diameter of conductor casing, by forming two bores, spaced substantially 180° apart, wherein a portion of each bore is formed from a portion of the inner wall of the conductor casing;
is adapted to be run and deployed downhole in a conductor casing on at least one running string, independently from any casing string; and
has tapered upper and lower entry surfaces or shoulders which ease passage of the downhole guide member within the conductor casing.
The downhole casing guide member of the present invention comprises a structure having a center longitudinal axis substantially coincident with the center longitudinal axis of the conductor casing, wherein the formation of such structure in a plane perpendicular to such center axis is generally "Y" shaped in two opposite directions about the center longitudinal axis of the structure. In other words, the formation of such structure in a plane perpendicular to such center longitudinal axis is generally "Y" shaped in a first direction and generally "Y" shaped in a second direction offset 180° from said first direction.
In view of the above, it is an object of the present invention to provide a downhole casing guide member comprising a structure having a center spacing member elongated in the plane perpendicular to the longitudinal axis of the conductor casing; a first pair of radial leg support members wherein each radial leg support member of the first pair flares radially angularly in different directions from one end of the elongated center spacing member; and a second pair of radial leg support members wherein each radial leg support member of the second pair flares radially angularly in different directions from the other end of the elongated center spacing member. The gaps between the two radial leg support members of the first and second pairs form first and second passages, respectively, for fluid flow therethrough.
Another object of the present invention is to provide a structure with first and second cavities which have axes parallel to the center longitudinal axis of the conductor casing. The first and second cavities extend into the first and second passages, respectively, for passage therethrough of first and second tubular members or "running strings" wherein the tubular members are clamped in their respective cavities with respective clamping bracket members. At least one of the first and second tubular members is required to lower the downhole casing guide member downhole in the conductor casing to a predetermined depth.
A further object of the present invention is to provide such a downhole casing guide member which is capable of being lowered downhole via at least one tubular member running string clamped thereto. Therefore the use of the surface casing string for lowering the downhole casing guide member is eliminated and the surface casing string need not be secured to the downhole casing guide member.
It is a still further object of the present invention to provide the uniquely contoured structure with two trough-shaped conduits, each spaced substantially 180° apart, thereby forming two bores for guiding in each bore a respective casing string downhole and maintaining each such respective casing string in substantially fixed spaced relation with respect to the other downhole in the conductor casing. One of the trough-shaped conduits is formed by a first concaved surface connecting the distal end of the first radial leg support member of the first pair and the distal end of the first radial leg support member of the second pair. The other trough-shaped conduit is formed by a second concaved surface connecting the distal end of the second radial leg support member of the first pair and the distal end of the second radial leg support member of the second pair. The first bore, for guiding therein a first surface casing string, is defined by the trough-shaped conduit and the curvature of the interior surface of the conductor casing between the first radial leg support member of the first pair and the first radial leg support member of the second pair. The second bore, for guiding therein a second surface casing string, is defined by the trough-shaped conduit and the interior surface of the conductor casing between the second radial leg support member of the first pair and the second radial leg support member of the second pair.
It is a still further object of the present invention to provide two bores which have a distorted circular outline to provide passageways on each side of a surface casing string when run in its respective bore wherein such passageways allow drilling fluids and/or cement slurries to flow along the side of the surface casing strings within the bore of the conductor casing.
It is a still further object of the present invention to provide such a downhole casing guide member which allows the diameter of the two surface casing strings which may be run within a conductor casing to be maximized.
It is a further object of the present invention to provide a downhole casing guide member which has a top surface and a bottom surface parallel to the top surface wherein the top surface and the bottom surface have beveled ends in close proximity to the outer perimeter thereof, for enhancing passage of the downhole casing guide member into and out of the conductor casing. More specifically, at least a portion of the top and bottom surfaces of each of the radial leg support members of the first and second pairs are beveled.
In view of the above objects it is a feature of the present invention to provide a downhole casing guide member which generally includes a uniquely contoured unitary structure and two clamping support bracket members capable of being secured to such structure.
It is another feature of the present invention to provide a downhole casing guide member which is structurally relatively simple.
It is a further feature of the present invention to provide a downhole casing guide member which is relatively inexpensive to manufacture, and which may be formed in a unitary design, such as by casting or molding.
The above and other objects and features of the present invention will become apparent from the drawings, the description given herein, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a further understanding of the nature and objects of the present invention, reference should be had to the following description in conjunction with the accompanying drawings in which like parts are given like reference numerals:
FIG. 1 is a perspective view of the downhole casing guide member of the present invention;
FIG. 2 is a top view of the downhole casing guide member of the present invention;
FIG. 3 is a top view of the downhole casing guide member installed in a conductor casing and having the first and second casing strings received within the two bores and the two tubular members clamped to the downhole casing guide member;
FIG. 4 is a sectional view along the plane of 4--4 of FIG. 31
FIG. 5 is a sectional view along the plane of 5--5 of FIG. 3;
FIG. 6 is a sectional view of FIG. 4, with running strings in place;
FIG. 7 is a sectional view of FIG. 5, with running strings in place; and
FIG. 8 is a perspective view of a plurality of downhole casing guide members of the present invention, being run into a conductor casing for placement therein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, and in particular FIGS. 1-7, the downhole casing guide member of the present invention is designated generally by the numeral 10. Certain of the drawings omit certain of the reference numerals for clarity. Downhole casing guide member 10 is generally comprised of structure 20 and first and second clamping bracket members 50a and 50b.
Structure 20 has a unitary formation bounded by the inner diameter of conductor casing 5. The unitary formation should provide for a sufficient annular clearance to allow downhole casing guide member 10 to fit within the inner diameter of conductor casing 5 and be lowered to a desired depth in conductor casing 5, as will be herein described. In the exemplary embodiment, downhole casing guide member 10 is bounded radially by radius R1, and is lowered in conductor casing 5 which has an inner radius slightly greater than radius R1. Downhole casing guide member 10 may be dimensioned to fit in any size conductor casing 5.
Structure 20 has center longitudinal axis 8 parallel to the center longitudinal axis of conductor casing 5. The unitary formation of structure 20 in a plane perpendicular to center axis 8 is generally "Y" shaped in two opposite directions about center longitudinal axis 8. In other words, the unitary formation of structure 20 in a plane perpendicular to center longitudinal axis 8 is generally "Y" shaped in a first direction and generally "Y" shaped in a second direction, where the second direction is offset 180° from the first direction. With downhole casing guide member 10 in place in conductor casing 5, the interior area of conductor casing 5 is substantially divided into two halves.
As can be readily seen, the unitary formation of structure 20 significantly reduces the cross sectional area of structure 20 occupying the interior of conductor casing 5, thereby maximizing the diameter of casing strings 7a and 7b (which may be surface casing strings) which can be run inside a given diameter of conductor casing 5. Moreover, the gap between the legs of each "Y" provides a passage for the flow of fluids, such as drilling fluids and/or cement slurries, therethrough.
More specifically, the unitary formation of structure 20 is defined by elongated center spacing member 23 which is elongated in a plane perpendicular to the center longitudinal axis of conductor casing 5; a first pair of radial leg support members 21a and 21b wherein each radial leg support member flares radially angularly in different directions from one end of elongated center spacing member 23; and a second pair of radial leg support members 22a and 22b wherein each radial leg support member flares radially angularly in different directions from the other end of elongated center spacing member 23.
The first pair of radial leg support members 21a and 21b and the second pair of radial leg support members 22a and 22b serve to center and support elongated center spacing member 23 within conductor casing 5, and additionally serve to section the interior of conductor casing 5. The gap between radial leg support member 21a and radial leg support member 21b of the first pair forms first passage 40a. Similarly, the gap between radial leg support member 22a and radial leg support member 22b of the second pair forms second passage 40b. First passage 40a and second passage 40b permit fluids, such as drilling fluids and/or cement slurries, to flow therethrough.
Structure 20 has first and second concaved surfaces 25a and 25b, is circumferentially spaced 180° apart, wherein such concaved surfaces 25a and 25b are substantially symmetrical about curvature mid points P1 and P2 and are bounded by circumference C. First and second concaved surfaces 25a and 25b form elongated center spacing member 23; in addition, first concaved surface 25a forms the exterior surfaces of radial leg support members 21a and 22a, and second concaved surface 25b forms the exterior surfaces of radial leg support members 21b and 22b.
First and second concaved surfaces 25a and 25b form first and second conduits 30a and 30b, respectively, which are trough-shaped and separated by elongated center spacing member 23. Elongated center spacing member 23 serves to space casing strings 7a and 7b within conductor casing 5. The distance from curvature mid point P1 of first concaved surface 25a, to point P1' on circumference C, is diameter D1. Likewise, the distance from curvature mid point P2 of second concaved surface 25b, to point P2' on circumference C, is diameter D2. Point P1' is essentially the mid point of that section of circumference C between radial leg support members 21 a and 22a. Point P2' is essentially the mid point of that section of circumference C between radial leg support members 21b and 22b.
With downhole casing guide member 10 in place within a conductor casing string, trough-shaped conduit 30a and the interior surface of conductor casing 5 between radial leg support members 21a and 22a form a first bore for guiding therethrough casing string 7a. Likewise, trough-shaped conduit 30b and the interior surface of conductor casing 5 between radial leg support members 21b and 22b form a second bore for guiding therethrough casing string 7b.
More specifically, trough-shaped conduits 30a and 30b defined by first and second concaved surfaces 25a and 25b, respectively, allow downhole casing guide member 10 to utilize the inner surface of conductor casing 5 to facilitate guiding casing strings 7a and 7b, respectively, downhole. Moreover, the use of the inner surface of conductor casing 5 allows the diameter of casing strings 7a and 7b to be maximized by eliminating any material or wall which would space casing strings 7a and 7b from the inner surface of conductor casing 5.
As can be appreciated, said first bore, having a portion thereof bounded by the interior surface of conductor casing 5, is capable of guiding therethrough casing string 7a wherein casing string 7a may have an outer diameter of slightly less than D1 or less to permit annular clearance of first casing string 7a within said first bore. Likewise, said second bore, having a portion thereof bounded by the interior surface of conductor casing 5, is capable of guiding therethrough casing string 7b wherein casing string 7b may have an outer diameter of slightly less than D2 or less to permit annular clearance of second casing string 7b. In the preferred embodiment, diameter D1 and D2 are equal.
As can be readily seen, said first bore and said second bore have distorted circular profiles in a plane perpendicular to the center axis of conductor casing 5. When first and second casing strings 7a and 7b are run through their respective bores, a gap exists on each side of first casing string 7a and on each side of second casing string 7b. Thereby, the contour of first concaved surface 25a provides first and second passageways 31a and 31a' when first casing string 7a is journalled in said first bore for permitting fluid (such as, without limitation, drilling fluids and cement slurries) flow therethrough. Likewise, the contour of second concaved surface 25b provides first and second passageways 31b and 31b' when second casing string 7b is run through said second bore for permitting fluid flow therethrough.
While said first bore and said second bore each have a distorted circular profile, the profiles do not compromise the necessary annular clearance for running therethrough first and second casing strings 7a and 7b, respectively. Moreover, the distorted circular profile of said first bore and said second bore provides a sufficient annular clearance which does not allow first casing string 7a and second casing string 7b, respectively, to roll side-to-side by any significant amount therein, when first and second casing strings 7a and 7b are maximized to D1 and D2, respectively, while providing passageways for the flow of drilling fluids and/or cement slurries.
The contour of first and second concaved surfaces 25a and 25b form first wedged shaped region A on one end of elongated center spacing member 23 and second wedged shaped region B on the other end of elongated center spacing member 23 wherein midpoints P3 and P4 of the arc defined by first and second wedged shaped regions A and B, respectively, are circumferentially spaced 180° apart. Structure 20 is not solid in first and second wedge shaped regions A and B. Instead, first and second wedged shaped regions A and B have formed therein first and second passages 40a and 40b, respectively. Since wedged shaped regions A and B are identical only one such wedged shaped region will be described in detail.
In the preferred embodiment, first passage 40a is generally trapezodially-shaped. Nevertheless, any geometrical shape may be substituted provided fluid flow is not significantly compromised. Trapezodially-shaped first passage 40a, formed in wedge shaped region A is defined by first and second linearly sloping surface walls 41a and 41b and surface wall 42. First and second linearly sloping surface walls 41a and 41b slope inwardly from circumference C to surface wall 42.
First and second linearly sloping surface walls 41a and 41b complete the contour of the first pair of radial leg support members 21a and 21b which radially project angularly in different directions from elongated center spacing member 23 and are bounded by circumference C. In other words, the exterior side surface wall of the first pair of radial leg support members 21a and 21b is curved and the interior side surface wall is linearly sloped.
In the preferred embodiment, top surface 47 and the bottom surface 47' of radial leg support members 21a, 21b, 22a, and 22b of structure 20 are beveled to the distal ends thereof, forming shoulders 60, to facilitate the upward and downward movement of downhole casing guide member 10 downhole in conductor casing 5.
Each end portion 23a and 23b of elongated center spacing member 23 is flared as a result of the curvature of first and second concaved surfaces 25a and 25b. End portion 23a of elongated center spacing member 23 has formed therein arch-shaped cavity 27a. Arch-shaped cavity 27a may be semicircular or any other desirable arch shape. Similarly, end portion 23b of elongated center spacing member 23 has formed therein arch-shaped cavity 27b, which may be semicircular or any other desirable arch shape.
Since first and second clamping bracket members 50a and 50b are identical, only one will be described in detail. First clamping bracket member 50a comprises longitudinal support bar member 51a and first and second transverse bars 52a and 53a. Longitudinal support bar member 51a is longitudinally aligned substantially parallel to the center axis of conductor casing 5, thereby presenting minimal obstruction to fluid flow thereby. One end of longitudinal support bar member 51a has first transverse bar 52a coupled thereto, while the other end of longitudinal support bar member 51 a has second transverse bar 53a coupled thereto. Means for fastening first clamping bracket member 50a to structure 20 are provided, to fasten first clamping bracket member 50a to structure 20 with longitudinal support bar member 51a aligned substantially parallel to the center axis of structure 20 (and also of conductor casing 5, as described above). In the preferred embodiment, the means for fastening first clamping bracket member 50a to structure 20 comprises a plurality of threaded bolts 45 engaging threaded holes 45a in structure 20, with nuts 45c made up on bolts 45 and holding first clamping bracket member 50a securely to structure 20. Other fastening means well known in the art may also be used. In the preferred embodiment, first clamping bracket member 50a is formed from a integral construction of longitudinal support bar member 51a and first and second transverse bars 52a and 53a of metal alloys, by casting or forging. However, it is understood that first clamping bracket member and first and second transverse bars 52a and 53a may also be made of separate pieces joined by welding or other suitable means.
First and second transverse bars 52a and 53b, as may be clearly seen in FIGS. 1, 2, and 3, comprise a generally half-circle cutout 70 which is disposed substantially opposite cavity 27a in structure 20. Together, cutout 70 and cavity 27a comprise a circular area when first clamping bracket member 50a is attached to structure 20, providing a location for placing a tubular member 9a in said circular area and clamping structure 20 to tubular member 9a, as will be later described.
Second clamping bracket member 50b is of like construction to 50a. First and second transverse bars 52b and 53b, as may be seen in FIG. 4, comprise a generally half-circle cutout 80 which is disposed substantially opposite cavity 27b in structure 20. Together, cutout 80 and cavity 27b comprise a circular area when second clamping bracket member 50b is attached to structure 20, providing a location for placing a tubular member 9b in said circular area and clamping structure 20 to tubular member 9b, as will be later described. As described above, second clamping bracket member 50b is attached to structure 20 by bolts or other like means, well known in the art.
In the preferred embodiment, longitudinal support bar members 51a and 51b are an elongated arch-shaped in profile, bringing the outer extremities of longitudinal support bar members 51a and 51b substantially to circumference C. Thereby, longitudinal support bar members 51a and 51b provide added support for structure 20 by bearing against the inner wall of conductor casing 5.
Although many different materials and method of manufacture may be used to form structure 20 and clamping bracket members 50a and 50b, in one embodiment ductile iron is used. Furthermore, forming structure 20 in unitary fashion, such as by casting, produces a structure having high strength and minimum mass and consequently volume. However, it is understood that other materials may be used to form structure 20 and clamping bracket members 50a and 50b: other ferrous materials; non-ferrous materials, such as aluminum, zinc, and/or bronze alloys; and non-metallic materials such as plastics or fiber-reinforced composites. Other methods of manufacture of structure 20 and clamping bracket members 50a and 50b, depending upon material, could be molding, forging, welding together of sub-components, or other methods known in the art.
One method of use of the apparatus of the present invention is now described. With reference to FIGS. 6, 7, and 8, tubular member 9a, which may be casing, tubing or drill pipe having a diameter of approximately 5" in an exemplary embodiment, is affixedly secured in arch-shaped cavity 27a via first and second transverse bars 52a and 53a of first clamping bracket member 50a. Tubular member 9b is affixedly secured in arch-shaped cavity 27b via first and second transverse bars 52b and 53b (only 53b shown) of second clamping bracket member 50b. The addition of arch-shaped cavities 27a and 27b for securing therein tubular members 9a and 9b provide a sufficient amount of unoccupied space in first and second passages 40a and 40b to allow fluids to flow through first and second passages 40a and 40b. While the preferred embodiment utilizes two tubular members to lower downhole casing guide member 10, it is understood that in alternative embodiments only one such tubular member may be used.
Thereafter, as illustrated in FIG. 8, a first (and ultimately deepest-set) downhole casing guide member 10 is lowered into conductor casing 5. Once a predetermined spacing has been reached, another downhole casing guide member 10 is clamped to first and second tubular members 9a and 9b. The assembly is then continued to be lowered into conductor casing 5, installing downhole casing guide members 10 at predetermined spacings, which in the exemplary embodiment may be every 100 to 150 feet, until the bottommost downhole casing guide member 10 is at a desired depth within conductor casing 5. For example, the lowermost downhole guide member 10 may be lowered to the seat (not shown) in the lower portion of primary conductor casing 5. Thus, in a 1000' conductor casing, approximately ten downhole casing guide members 10 will be employed. First and second tubular members 9a and 9b may also serve to suspend downhole casing guide member 10 within primary conductor casing 5.
Next, a drilling assembly is lowered down one of the conduits thus formed in conductor casing 5, and a wellbore is drilled (having a diameter sufficient for the surface casing to be run) down to the desired surface casing setting depth. A first casing string 7a is then run to its setting depth and cemented in place. The second wellbore is then drilled in the remaining conduit, and a second casing string 7b is run and cemented in place.
A slightly different sequence of operations may also be followed. After the assembly of downhole guide members 10 is in place within conductor casing 5, when forming the first well of the multiple wells, first casing string 7a is lowered downhole to a depth sufficient to place first casing string 7a within the lowermost downhole casing guide member 10. Thereafter, a drillstring is run down first casing string 7a and drilling and/or under reaming is carried out to a desired casing running depth for first casing string 7a. The drillstring is removed, and first casing string 7a is lowered to said desired casing running depth and cemented in place. A similar process is carried out for second casing string 7b. Once casing strings 7a and 7b are cemented in place, drilling of the remainder of each well proceeds in generally conventional manner, well known in the art.
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 downhole casing guide member comprising a structure having a unitary formation wherein in a plane perpendicular to a center longitudinal axis of the structure, the unitary formation is generally "Y" shaped in two opposite directions about the center longitudinal axis. The downhole casing guide member further comprises at least one clamping bracket member securable to the structure. The unitary formation of the structure serves to maximize available flow area for flow of fluid, liquid slurry and/or cement around the contour of the unitary formation and maximize the diameters of casing strings which may be run within a conductor casing; and tapered upper and lower shoulders on the casing guide member ease passage of the guide member into and out of a conductor casing. Further, the overall configuration and shape of the downhole guide member eases passage of casing strings lowered into or removed from the conduits formed by the guide member. | 4 |
TECHNICAL FIELD
The present invention relates to snow skis or snow boards that are adapted to be ridden and which have bindings mounted thereon. In particular, the present invention relates to fiber reinforced skis such as those formed by the wet wrap or torsion box process wherein a wooden or foam plastic core is wrapped with a fiber-reinforced sheet impregnated with resin, and then cured under pressure in a mold with a base assembly. The term "fiber reinforced" is meant to include any high modulus fibrous materials such as glass, aramid fibers such as Kevlar™, graphite, metal wire, polyester, etc.
BACKGROUND OF THE INVENTION
High performance skis are carefully designed in order to give the user maximum control during skiing. This includes designing the skis to cleanly "carve" turns; that is, during the carving of a turn, every point on the edge of the ski is designed to pass over a single point on the snow. In order to accomplish this, skis are shaped with curved edges such that the waist portion of the ski is narrower than the shovel or tail portions of the ski. In addition to the exterior shape of the ski, the structural core of the ski is carefully tailored such that the ski has the ability to smoothly flex over its length during the carving of a turn.
During skiing, a snow ski flexes continuously both in response to irregularities in the snow and in response to the user's movements, such as during turning. Flexing of a fiber-reinforced ski causes the various layers of fiberglass and other materials that make up the body of the ski to shear with respect to each other. Elements of the ski which effect the interlaminar shear of the materials that make up the ski affect the resulting flex of the ski. As discussed above, skis are designed to flex freely over their length and in accordance with certain desired flex patterns. Elements of the ski that interfere with such flex patterns undesirably affect the performance of the ski.
Mounting ski bindings on the upper surface of skis and positioning relatively rigid boots within the bindings are known to interfere with the desired flex patterns of the ski. Ski bindings are typically mounted on the top surface of the narrowed waist portion of the ski through the use of screw-type fasteners that extend through the top surface of the ski downward into the core of the ski. A number of fasteners are typically used to hold both the toe piece and heel piece of the binding to the ski. Each of these fasteners pierce the layers of fiberglass and other materials positioned within the body of the ski. This compresses the layers of the ski together and reduces their ability to shear with respect to each other during flexing of the ski. Furthermore, the positioning of a rigid plastic ski boot between the toe and heel pieces of a ski binding tends to prevent the ski from flexing in the area beneath the ski boot, thus creating an inflexible "flat" spot in the ski. The introduction of a "flat" or relatively inflexible portion to the center of the ski reduces the ability of the ski to flex over its length, thus affecting the ski's ability to carve a smooth turn.
A related problem is the tendency of screw-type fasteners, used to hold the bindings to the ski, to pull out of the ski under the significant stresses commonly encountered during skiing. Metal reinforcing plates, such as those shown in U.S. Pat. Nos. 3,498,626; 3,635,482; 3,671,054; 3,844,576; 3,861,699; 3,901,522; 3,917,298; 3,928,106; 4,349,212; 4,639,009; and 4,671,529, are commonly used to provide a base element within the body of the ski into which the fasteners may be screwed and held. This helps to solve the problem of fastener pullout but increases the problems related to ski flexing, due to the introduction of a very stiff element to the narrowed waist portion of the ski.
A number of prior art patents attempt to deal with the problems associated with mounting bindings on a ski. U.S. Pat. No. 2,560,693 discloses a separate foot plate system for allowing a ski to flex uniformly over its entire length. This foot plate system is screwed directly into the body of the ski at its ends, consequently, the screws which mount the foot plate system to the skis compress the various layers that make up the body of the ski. Furthermore, the foot plate system raises the bindings and boots off of the upper surface of the ski, thus affecting the ski's performance.
U.S. Pat. No. 4,141,570 discloses the use of an elevated platform to allow the ski to flex between platform supports. However, the platforms themselves are screwed into the body of the ski thus creating the same problems described above. U.S. Pat. No. 3,997,178 discloses a cross-country ski having a two-layer core with the uppermost layer of the core consisting of wood having a thickness of at least 1.5 mm at its thickest part. The wood upper layer stiffens and increases the resistance of the ski to bending and also acts to prevent the binding screws which extend through the plate into the core of the foam plastic ski from being torn out during skiing.
Another system that attempts to reduce the problems caused by mounting bindings on a ski is the so-called "Derby Flex" system described in PCT Patent No. CH83/00039. This system comprises an aluminum plate overlying a hard rubber substrate. The aluminum plate spans the narrowed waist portion of a ski and allows ski bindings to be screwed directly through the aluminum plate and into the rubber substrate rather than directly into the core of the ski. The aluminum plate, however, is screwed directly into the ski at each end in order to attach the aluminum plate to the ski. Consequently, the screws mounting the aluminum plate compress the layers of material forming the body of the ski, thus interfering with the interlaminar shear between the layers of the ski. Furthermore, the Derby Flex system raises the bindings and ski boot away from the body of the ski, thus changing the profile and influencing the performance of the ski.
In addition to flexing of the ski, vibrations in the ski affect both the performance and the comfort of the ski during use. A highly vibratory ski is not as responsive in precise turns, especially on icy slopes. In addition, high frequency vibrations in skis, approximately 150 Hz and above, tend to be transmitted through the binding to the ski boot and user.
German Patent No. 3,934,888 discloses a system for reducing shock and vibration between a ski and a ski binding through the use of a damping plug recessed into a chamber in the body of the ski. German Patent No. 3,934,891 discloses the placement of a viscoelastic layer on the top surface of a ski in between the ski and binding. The binding screws extend through the viscoelastic layer and into the structural layers which make up the body of the ski.
One goal of the present invention is to reduce the effects of the mounting of ski bindings and ski boots on a ski upon the flex patterns of the ski. A related goal is to reduce the transmission of shock and vibration between a ski and a ski binding and ski boot mounted thereon. The present invention achieves this goal without changing the side profile of the ski or adding additional mounting plates to the top of the ski.
SUMMARY OF THE INVENTION
The present invention provides a unique ski construction including an integral binding mounting plate having a thickness sufficient to fully encompass the depth of the binding mounting screws so that the screws do not pass into the body of the ski. A layer of viscoelastic material is positioned between the binding mounting plate and the body of the ski and bonded to each of these elements, whereby the binding mounting plate is both held in place and isolated from the ski body.
The body of the ski of the present invention is designed to flex uniformly along its length to allow for the precise carving of turns. The mounting of ski bindings and boots on the isolated binding mounting plate reduces their interference with the flex patterns of the ski. An integral ski binding mounting plate is thus provided that helps to allow the ski to flex independently of the binding system. The binding mounting plate of the present system accepts most current bindings irrespective of size or shape.
In one embodiment, the ski body is provided with a recess in its top surface adjacent to the narrowed waist portion of the ski. The binding mounting plate is correspondingly shaped to fill the recess in a manner such that the conventional smooth curved top surface of a ski is achieved.
If desired, additional flexible reinforcing material such as fiberglass cloth or mat, or thin sheets of aluminum or steel, may be placed in the narrowed waist portion of the ski to locally strengthen the ski and ensure uniform flexing along its length.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a perspective view of a snow ski with an integral binding isolation mounting plate according to the present invention;
FIG. 2 is a cross-sectional view of the binding isolation mounting plate and ski of FIG. 1;
FIG. 3 is an enlarged exploded side elevational view of the binding isolation mounting plate of FIG. 1;
FIG. 4 is an enlarged side elevational view of the binding isolation mounting plate of FIG. 1 after it has been attached to the body of the ski.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a snow ski comprising a ski body 8 and an integral binding isolation system 9 according to the present invention. The ski body is formed with an upturned shovel portion 10 which prevents the front of the ski from digging into the snow. The body narrows as it progresses longitudinally along its length until it reaches a narrowed waist portion 12 at which point it extends longitudinally and widens into a tail portion 14. As described above, this exterior shape helps the ski carve a proper turn in which the ski turns around a single point in the snow.
As illustrated in FIG. 2, the body of the ski comprises a structural but flexing core 40 which has been shaped to form the shovel portion, waist portion and tail portion of the ski. The core 40 can be formed of any suitable material commonly used in ski fabrication, including wood, a honeycomb metal structure, structural foam, etc. In order to strengthen and stiffen the core, it is desirable to wrap the core 40 with a fiber reinforced layer 42. The fiber reinforced layer could include a triaxially braided composite structure as described in U.S. Pat. No. 4,690,850 (Fezio), a fiber reinforced cloth, a filament wound structure, layers of unidirectional fiber reinforced prepreg or other suitable reinforcement materials.
A number of high modulus fibrous materials can be used to form the reinforced layer 42, including glass, graphite, aramid fibers such as Kevlar™, metal wire and polyester to name a few. The reinforced layer 42 may be formed of a fibrous material that has been preimpregnated with a matrix system, or may be formed of dry fibers which are later impregnated with a matrix. Possible matrix systems include epoxy resins, other adhesive systems, thermoplastic matrix systems, or other suitable high strength, flexible matrix systems.
The number of layers of material, fiber orientations in each layer, and thickness of each material used to reinforce the core 40 are carefully determined to ensure that the finished ski will have the proper structural characteristics. This includes designing the ski such that it has the proper vibration characteristics, can withstand the structural loads present in the application and can properly flex in order to give the ski the ability to cleanly carve a turn.
In order to protect the core 40 and reinforced layer 42, and to cosmetically enhance the ski, protective side walls 44 and top layer 45 may be placed on the vertical side surfaces and top layer, respectively, of the combined core assembly. In the preferred embodiment, the side walls and top layer are formed of a durable protective material such as ABS or ABS/urethane. However, any suitable material that can withstand the harsh temperature environment and punishment experienced by a ski may be used, such as plastics or metals.
In order to achieve high performance, the lower edges of a ski must be able to cut into the snow and ice to allow the skier to perform a turn. Therefore, it is desirable that the lower edges of the ski be formed of a material which can achieve this goal. In the preferred embodiment, two steel edges 46 are placed at the lower corners of the ski. The edges extend longitudinally along the length of the ski and can be formed of any material which creates a durable, sharp edge capable of cutting into snow and ice. The cutting edges 46 are typically formed of steel alloys capable of holding a sharp cutting edge.
To increase performance, a smooth, slick running surface 48 is placed upon the lower surface of the core assembly. The running surface can be formed of any appropriate material which creates a smooth friction-free running surface that allows the ski to move freely over the snow and ice. In the preferred embodiment, sintered polyethylene is used to form the running surface, however other plastics or Teflon™ materials could also be used.
According to the present invention, the body 8 of the ski is formed with an integral binding isolation system 9. The isolation system comprises a recess 32 located on the top surface of the ski in the narrowed waist portion 12 (FIGS. 3 and 4). A layer 60 of viscoelastic material is placed in the recess 32 between the body of the ski and a binding mounting plate 30. The recess 32, layer 60 and mounting plate 30 are formed such that they establish a smooth upper surface of the ski, i.e., the upper surface of the mounting plate forms a smooth continuation of the upper surface of the body of the ski at opposite ends of the recess.
The term "viscoelastic" as used herein means any material capable of storing energy of deformation, and in which the application of a stress gives rise to a strain that approaches its equilibrium value slowly, an example of which is rubber.
An adhesive material capable of bonding the layer 60 to the mounting plate and body of the ski is placed on both surfaces of the layer. The adhesive material could be any material capable of properly bonding the viscoelastic material used to the body of the ski and the binding plate, such adhesives could include epoxy resins, rubber cements or other adhesive systems. The layer 60 may be formed of any suitable viscoelastic material such as urethane or rubber, and the bonding adhesive may be an epoxy resin.
The thickness of the viscoelastic layer 60 should be determined based upon two parameters. First, the thickness of the viscoelastic material should be determined such that the finished ski, complete with bindings and attached ski boot is capable of flexing in a desired manner over the entire length of the ski. Additionally, the thickness of the viscoelastic material should be determined such that, as the body of the ski flexes, the interlaminar stress present between the body of the ski, viscoelastic material, and binding plate are not so high as to destroy the bonds holding the separate parts of the ski together. In general, the thickness of the viscoelastic layer depends on the choice of material used and the amount of isolation and damping desired. In one preferred embodiment, the viscoelastic material is urethane having a thickness of 0.010 inches, but it should be understood that a layer having a thickness in the range of 0.005 to 0.05 inches would be satisfactory.
The viscoelastic material allows the mounting plate 30 to be connected to the body of the ski such that the ski is free to flex without being rigidly restricted by the mounting plate 30. In this design, when the body of the ski flexes, the resulting deformation and interlaminar stress between the body of the ski and mounting plate are contained primarily within the viscoelastic material forming the layer 60. This allows the binding to be mounted to the ski such that it is not rigidly secured along its length to the body of the ski, and instead the body of the ski is free to flex independently of the binding and mounting plate 30.
In alternate embodiments, not shown, some portions of the mounting plate 30 could extend through the viscoelastic layer 60 to provide added stability for the mounting plate 30 with respect to the body of the ski. However, in these embodiments, these portions of the mounting plate should not be rigidly connected to the body of the ski and should therefore ideally not be fixedly attached to the body of the ski.
In order to strengthen the ski and for the body of the ski to flex over its length in a desired flex pattern, it may be beneficial to reinforce the narrowed waist portion of the ski containing the recess 32. The decreased cross-sectional area at the recess 32 could result in the ski being weaker and more flexible along the length of the recess than elsewhere along the length of the ski. This could result in the ski having an undesirable flex pattern and, consequently, poor ability to a turn. It may be beneficial, therefore, to reinforce the narrowed waist portion of the ski containing the recess 32 by placing a reinforcing layer 34 along the upper surface of the core and/or a reinforcing layer 36 along the lower surface of the core. The reinforcing layers 34 and 36 could be additional layers of fiberglass or other materials with the same stiffness as the rest of the layers 42, or the reinforcing layers 34 and 36 could be formed of a higher modulus material such as graphite. The thickness and materials used to reinforce the section of the ski containing the recess 32 should be selected such that the finished ski flexes in a continuous curve along its length during turning.
The mounting plate 30 is formed similarly to the body of the ski. A center core 62 (FIG. 2) is formed to the proper shape and is then overlaid by a reinforcing layer 65. The reinforcing layer could be a triaxially braided composite structure, a fiber reinforced cloth, a filament wound structure, or layers of unidirectional fiber reinforced prepreg. To ensure that mounting screws do not pull out of the mounting plate 30, it could be advantageous to place an additional layer of material 64 between the core 62 and the reinforcing layer 65. This additional layer could be a chopped fiberglass mat, as in the preferred embodiment or a number of other materials such as fiberglass cloth, Kevlar™ cloth, a metal sheet, a plastic sheet, or other similar materials.
In order to protect the interior structure and cosmetically enhance the ski, a protective side wall 68 and top surface 66 are then placed around the core and reinforcing layers. It will be understood that for cosmetic reasons, the top surface 66 will typically be formed of the same conventional material used to form the top surface of the shovel and tail of the ski, for example, ABS or ABS/urethane. After laying up the mounting plate 30, the combined assembly including the body of the ski, the viscoelastic material, and the mounting plate are then cured as a combined assembly under proper temperatures and pressures for the resins or adhesives used throughout the structure. In the preferred embodiment, the combined assembly is cured as one piece, however, the mounting plate and body of the ski could be cured separately and then bonded to the viscoelastic layer 60 using a suitable adhesive as described above.
The recess 32 and mounting plate 30 are sized such that they are long enough to be used as a mounting plate for a conventional ski binding. In addition, the thickness of the mounting plate is sized such that it is thick enough to contain the fasteners 22, used to mount the ski bindings, within the depth of the mounting plate, thus preventing the fasteners from piercing the layer 60 or the body of the ski.
The toe and heel bindings 16 and 18 are illustrated representations only and it is contemplated that the invention will be usable with all standard release bindings. As illustrated, both the toe binding 16 and the heel binding 18 are fixedly secured to the mounting plate 30 through the use of fasteners 22. The fasteners 22 could be any type of screw fastener capable of being secured within the mounting plate without piercing the layer 60 or the body of the ski. In the preferred embodiment, the mounting plate 30 is 9 millimeters thick and is intended to be used with conventional 8 millimeter long binding screws.
The use of the mounting plate 30 allows a relatively stiff, structurally solid mounting surface to be used to mount the bindings to the ski. This prevents the fasteners from being pulled loose from the ski under the significant stresses commonly encountered during skiing. Furthermore, the use of a separate mounting plate 30 and viscoelastic layer 60 to isolate the bindings and ski boot from the ski body creates significant advantages. In a standard ski, the mounting of different brands and types of ski bindings upon the ski affects the flexing of the ski. Therefore, in order to ensure proper performance, a skier may have to try a number of different combinations of skis and bindings in order to get the characteristics desired. In the present invention, the bindings are isolated from the ski body, therefore selection of bindings does not significantly affect the flexing, or performance of the ski.
In addition, the present invention allows the ski to flex over its entire length in the fashion for which it was designed. The effects of the flat or relatively inflexible portions of a ski created by prior binding mounting techniques are eliminated. Furthermore, the viscoelastic material serves to dampen high frequency vibrations that would otherwise be transmitted through the bindings to the skier. All these advantages are gained without the addition of unsightly plates mounted on top of the ski which change the side profile of the ski and affect the ski's performance.
It will be understood that while the present invention finds its principal application in connection with snow skis, the concept disclosed may also be applied to snowboards, since snowboard bindings are also typically screwed into the body of the board with consequent reduction in edge control.
While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention. As an example, the materials used to fabricate the body of the ski or the mounting plate could be changed. Similarly, the shape of the mounting plate or recess could be changed. | A snow ski has a main body with a recess located in the central portion of the top surface of the ski. The recess is adapted to receive a complementary shaped ski binding mounting plate which is bonded to an intermediate layer of viscoelastic material, which is, in turn, bonded to the main body of the ski. The ski binding mounting plate has a thickness such that the fasteners used to hold the ski binding thereon do not extend through the mounting plate into the body of the ski. The body of the ski may also include reinforcing material in the central portion of the ski containing the recess. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation, of U.S. patent application Ser. No. 12/643,280, filed Dec. 21, 2009, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Aspects of the invention relate generally to routing data in computer networks. More particularly, aspects are directed to deadlock prevention in computer networks regardless of system configuration.
[0004] 2. Description of Related Art
[0005] In many communication networks, multiple processors are often employed. The processors may be arranged in different configurations. For instance, an array of processors may be configured in a mesh or torus architecture. The array may also be interconnected to other arrays in different networks.
[0006] Various routing schemes, including flow control, have been employed to pass data between components within such communication networks. However, some communication networks use flow control mechanisms that can stall traffic on a link into a switch of a node until buffer space or other resources become available. Blockage on an output link of a network node may propagate backwards across the switch and stall its input links that are trying to route the stalled output.
[0007] A condition known as “deadlock” can arise in which a stalled link is indirectly dependent upon itself. Deadlock is a serious condition causing loss of data errors and which may require a network restart to correct. Previously, different techniques have been employed to combat deadlock. Unfortunately, such techniques may fail in different situations.
[0008] For instance, a “turn model” may require specific restrictions for each type of network topology. The turn model may fail when the network is missing a link or switch and no longer provides a complete topology. In “up*/down*” routing, an arbitrary network is covered by a spanning tree. Routes are constrained to flow in certain directions; however this may lead to link load imbalance near the root of the spanning tree and may also require a network restart when a link or switch goes down. In “folded Clos” or “fat tree” type networks, deadlock is addressed by imposing route restrictions that may be unduly limiting.
SUMMARY OF THE INVENTION
[0009] Systems and methods which incorporate blocking flow control to prevent deadlock are provided. Such systems and methods function are designed to function even when a network or routes within the network are changed.
[0010] In one embodiment, a method of routing packets in a computer network to avoid deadlock is provided. The method includes assigning a distinct identifier to each switch in the computer network. The distinct identifier is unique to each respective switch. The method also includes setting a turn rule for routing packets across the computer network so that deadlock is avoided. The turn rule prohibiting sending packets from a first switch (A) to a second switch (C) via an intermediate switch (B) given a selected condition. The condition is selected from the group consisting of the distinct identifier of intermediate switch B has a value greater than the values of the distinct identifiers of both first switch A and second switch C, or the distinct identifier of intermediate switch B has a value less than the values of the distinct identifiers of both first switch A and second switch C. The method further includes providing the turn rule to each switch in the computer network, and routing the packets across the computer network according to the turn rule. The selected condition is maintained for subsequent packet routing.
[0011] In one example, the first switch A, second switch C and intermediate switch B are configured for adaptive routing. In another example, first switch A, second switch C and intermediate switch B each maintain multiple routing tables. In a further example, the distinct identifier of each switch is a hash of a hardware identifier.
[0012] In one alternative, the method further comprises supporting a plurality of virtual channels in each switch; determining whether the turn rule would be violated given the selected condition; setting a virtual channel rule that permits violation of the turn rule by selecting a unique ordering of the plurality of virtual channels; and routing the packets across the computer network according to the virtual channel rule, wherein the virtual channel rule is maintained for subsequent packet routing.
[0013] In another alternative, the method further comprises supporting a plurality of virtual channels in each switch, determining whether the turn rule would be violated given the selected condition, and setting a virtual channel rule that permits violation of the turn rule if one and only one of the following conditions occurs: monotonically increasing a virtual channel number from a first channel number to a higher channel number, or monotonically decreasing the virtual channel number from the first channel number to a lower channel number. In this alternative, the method also includes routing the packets across the computer network according to the virtual channel rule. The virtual channel rule is maintained for subsequent packet routing.
[0014] In another example, the computer network is a butterfly network architecture. In a further example, the computer network comprises a chip multiprocessor architecture and each switch is coupled to an associated processor.
[0015] In accordance with another embodiment, a computer-readable recording medium is provided. The recording medium has instructions stored thereon. The instructions, when executed by a processor, cause the processor to perform the operations of assigning a distinct identifier to each switch in a computer network, the distinct identifier being unique to each respective switch; setting a turn rule for routing packets across the computer network so that deadlock is avoided, the turn rule prohibiting sending packets from a first switch (A) to a second switch (C) via an intermediate switch (B) given a selected condition, the condition being selected from the group consisting of: the distinct identifier of intermediate switch B has a value greater than the values of the distinct identifiers of both first switch A and second switch C, or the distinct identifier of intermediate switch B has a value less than the values of the distinct identifiers of both first switch A and second switch C; providing the turn rule to each switch in the computer network; and routing the packets across the computer network according to the turn rule, wherein the selected condition is maintained for subsequent packet routing.
[0016] In one example, the operations further comprise determining whether the turn rule would be violated given the selected condition; setting a virtual channel rule that permits violation of the turn rule by selecting a unique ordering of the plurality of virtual channels; and routing the packets across the computer network according to the virtual channel rule, wherein the virtual channel rule is maintained for subsequent packet routing.
[0017] In another example, the operations further comprise determining whether the turn rule would be violated given the selected condition; setting a virtual channel rule that permits violation of the turn rule if one and only one of the following conditions occurs: monotonically increasing a virtual channel number from a first channel number to a higher channel number, or monotonically decreasing the virtual channel number from the first channel number to a lower channel number; and routing the packets across the computer network according to the virtual channel rule, wherein the virtual channel rule is maintained for subsequent packet routing.
[0018] In a further embodiment, a computer system, comprises a plurality of switching elements that are disposed at respective nodes in the computer system. Each switching element is identified by a distinct identifier. Adjacent switching elements are directly connected to one another. Each switching element implements a turn rule for routing packets so that deadlock is avoided in the computer system. The turn rule prohibits sending packets from a first switching element (A) to a second switching element (C) via an intermediate switching element (B) given a selected condition. The condition is selected from the group consisting of: the distinct identifier of intermediate switching element B has a value greater than the values of the distinct identifiers of both first switching element A and second switching element C, or the distinct identifier of intermediate switching element B has a value less than the values of the distinct identifiers of both first switching element A and second switching element C.
[0019] In one example, the first switching element A, second switching element C and intermediate switching element B are configured for adaptive routing. In another example, the first switching element A, second switching element C and intermediate switching element B each store multiple routing tables. In a further example, the distinct identifier of each switching element is a hash of a hardware identifier of that respective switching element.
[0020] In an alternative, switching elements A, B and C each support a plurality of virtual channels and employ a virtual channel rule permitting violation of the turn rule by following a preselected unique ordering of the plurality of virtual channels.
[0021] In another alternative, switching elements A, B and C each support a plurality of virtual channels and employ a virtual channel rule permitting violation of the turn rule if one and only one of the following conditions occurs: monotonically increasing a virtual channel number from a first channel number to a higher channel number, or monotonically decreasing the virtual channel number from the first channel number to a lower channel number.
[0022] In yet another example, the computer system has a butterfly network architecture. In a further example, the computer system has a mesh network architecture.
[0023] In an alternative, the computer system comprises a chip multiprocessor architecture and each switching element is coupled to an associated processor. And in yet another alternative, the plurality of switching elements comprise routers in the nodes of a computer network. At least some of the routers are connected to hosts for transmitting data packets across the network.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 illustrates a multiprocessor architecture for use in accordance with aspects of the invention.
[0025] FIGS. 2A-B illustrate a router switch in accordance with aspects of the invention.
[0026] FIG. 3 illustrates a routing scenario in accordance with aspects of the invention.
[0027] FIG. 4 illustrates virtual channels for use with aspects of the invention.
[0028] FIG. 5 illustrates a multidimensional switch in accordance with aspects of the invention.
[0029] FIG. 6 illustrates a chip multiprocessor for use with aspects of the present invention.
DETAILED DESCRIPTION
[0030] Aspects, features and advantages of the invention will be appreciated when considered with reference to the following description of preferred embodiments and accompanying figures. The same reference numbers in different drawings may identify the same or similar elements. Furthermore, the following description is not limiting; the scope of the invention is defined by the appended claims and equivalents.
[0031] FIG. 1 illustrates an exemplary computer network architecture 100 for use with aspects of the invention. As shown, the architecture includes a number of switches (S 0 . . . S 63 ) at nodes 102 arranged in a mesh-type configuration. The switches S at adjacent nodes 102 in the X and Y directions of the mesh are connected to one another via connections/links 104 . For instance, switch S 9 is connected to switches S 1 , S 8 , S 10 and S 17 . While a mesh configuration is illustrated, any other architecture may be employed, including torus, butterfly, flattened butterfly and the like.
[0032] In the example of FIG. 1 , switches along the top (S 0 . . . S 7 ) and bottom (S 56 . . . S 63 ) nodes or the side nodes of the mesh may be connected to respective hosts 106 . Hosts may be, for instance, a processing device or computer system connected to the network via a network interface card. Each host 106 may originate and/or receive traffic from nodes in the network. As shown in this example, one switch S (e.g., S 0 , S 4 , S 61 ) connects to each host, although multiple hosts may connect to a single switch S. Other configurations may have multiple switches S connecting to a single host. In addition, certain hosts 106 may couple to another network 108 . All such configurations may be used in accordance with the invention as set forth herein.
[0033] FIG. 2A illustrates an example where a given node 102 includes a multi-port router switch 110 . In the configuration shown, the multi-port router switch 110 is a five-port router switch S. Four ports connect to adjacent nodes in the +X, −X, +Y and −Y directions of the mesh. The fifth port desirably connects to a processor 112 (e.g., a host) co-located at the switch's respective node. In this example, the switch 110 is switch S 4 of FIG. 1 . Thus, the −X direction port connects to switch S 3 , the +X direction port connects to switch S 5 and the −Y direction port connects to switch S 12 . As switch S 4 is located along a top edge of the mesh, its port in the +Y direction connects to a host 106 . While a five-port router switch is shown, other types of multi-port switches may be employed using any number of ports. By way of example, the Mellanox InfiniScale® IV 36 port switch device may be used. This switch device may be employed in a multidimensional 6-ary, 6-flat network topology. The switches used may be of different types or configurations.
[0034] Turning to FIG. 2B , this figure shows that the multi-port router switch 110 may include buffering 114 and a routing mechanism 116 for routing data packets to other nodes in the network. The router switch 110 may also include processing logic or firmware (“logic”) 118 for determining which next switch to route packets along.
[0035] In accordance with one aspect of the invention, each switch S preferably includes the following features. First, the switch S should have a high port count to properly enable routing in the network. For example, in a flattened butterfly network, there should be at least 28 ports per switch S. Other types of networks may employ less or more ports per switch or per dimension. Another feature is that the switch S should have adaptive routing capabilities. Preferably, the switch S should be able to have multiple routing tables in the switch. In this situation, not all ports are routed by a single routing table, enabling the switch to employ port specific routing.
[0036] FIG. 3 illustrates a routing example in accordance with aspects of the invention. Four router switches A, B, C and D are provided. One “turn” (A,B,C) through switch B comprises a pair of hops (A,B) and (B,C), moving a packet of data from A to C via B.
[0037] Each switch “X” is preferably assigned a permanent and distinct identifier “I(X).” The identifiers for the switches A, B, C and D are, respectively, I(A), I(B), I(C) and I(D). An identifier may be assigned by the network, for instance randomly or using a permanent hardware identity. Thus, in the case where the switch has an InfiniBand Globally Unique Identifier (“GUID”) or other unique identifier, that identifier or a hash thereof may serve as the distinct identifier.
[0038] In a real-world example, not all switches S or links 104 are always “up” or active. Generally speaking, there is usually at least one fault under repair. And new switches may be added to the network on an ad-hoc basis. Thus, in order to ensure consistency, the distinct identifier for each switch S preferably does not change over time.
[0039] For the example of FIG. 3 , there are four possible options for the distinct identifiers, namely:
[0040] I(A)<I(B)<I(C)
[0041] I(A)<I(B)>I(C)
[0042] I(A)>I(B)<I(C)
[0043] I(A)>I(B)>I(C)
[0000] A “flow dependence” exists when packet flow on a specific (virtual) channel depends on the ability of packets to flow on another channel. Flow on a channel into a switch is dependent on flow on a channel out of a switch if that switch is capable of routing traffic from the input channel to the output. This dependence relationship between virtual channels can lead to deadlock if any channel depends, directly or transitively, upon itself.
[0044] To avoid such problems, in one aspect routes across switches are determined according to the following rule. Any turn “A to B to C” from switch A across switch B to switch C may be used in a route unless it is the case where I(A)<I(B) and I(C)<I(B). The permanence of the identifiers I(X) guarantees safety from deadlocks even as switches and links come and go from the network and new routes are computed. In this scenario, deadlocks cannot arise even between old traffic and new traffic after a re-routing event because the comprehensive set of turns in all routes never contains a turn I(A)<I(B)>I(C).
[0045] Consider the example where A=4, B=5, C=2 and D=3. In the present embodiment, a packet is routed from A to C. Using the above rule, the packet cannot be routed through switch B, because 4 (A) <5 (B) >2 (C) . However, the packet can be routed through switch D, because 4 (A) >3 (B) >2 (c) . Thus, a turn (A,D,C) would be selected.
[0046] Alternatively, in another embodiment all turn combinations I(A)>I(B)<I(C) could be prohibited with the same effect as above, specifically guaranteed safety from deadlocks. In this case, turn (A,B,C) would be selected because unlike (A,D,C) it would not conflict with the prohibited relation. In the scenario, adjacent switches (e.g., A and B, B and C, A and D, or C and D) are directly connected to one another without any intervening switches.
[0047] The logic for performing adaptive routing may reside in the switches S at each respective node, such as in processing logic or firmware 116 of FIG. 2B . The routing logic is desirably integral to every switch S in the network. Each switch may determine which output port to employ using either a routing table or equivalent logic. A routing table provides flexibility and handles faults gracefully by easily re-routing packets. A “routing algorithm” is desirably implemented by programming the collective set of routing tables. Preferably, each switch S is configured to employ multiple routing tables to enable port specific routing. As changes to the network occur, the switches may recomputed some or all routes through the network.
[0048] Adaptive routing in accordance with an aspect of the invention maps local destinations to sets of ports. The switch managing a data packet may select which switch it will send the packet to. Preset packets sent from selected hosts may be employed to discover the network topology. Desirably, each switch S maintains a table with entries for every host in the network and distances to each host. The distance is determined by the number of hops (e.g., intervening switches/nodes) from the switch via intervening nodes to the host. A given switch may iterate on distance to compute hosts X hops away from itself. This may be done by evaluating neighboring switches. In one aspect, this distance determination is done while adhering to the rule set forth above, namely avoid turns where I(A)<I(B)>I(C), or where I(A)>I(B)<I(C).
[0049] Virtual channels may used to break deadlock in accordance with aspects of the invention by providing alternative routes between nodes in the network. Virtual channels may be employed in various networks to route data packets among nodes in the network. FIG. 4 illustrates an exemplary virtual channel configuration 200 for the routing mechanism 114 of the router switch 110 of FIGS. 2A-B . As shown in FIG. 4 , there is at least one pair of shared physical channels 202 into and out of the switch. A set of independent request and response virtual channels 204 may be multiplexed between the shared physical channels 202 and a crossbar architecture 206 .
[0050] According to one aspect, the aforementioned turn rule may be violated using virtual channels. Specifically, turn combinations of I(A)<I(B)>I(C)—or I(A)>I(B)<I(C)—are only allowed if that turn can be accompanied by a permanent transition to a higher (or lower) virtual network. In other words, networks with multiple virtual channels may use an otherwise impermissible turn to signal a point of transition to a higher-numbered (or lower-numbered) virtual channel. This may be accomplished by limiting the transitions to a preselected ordering of virtual channels.
[0051] Each switch may include N virtual channels. For example, when N=4, there are four virtual channels per physical link. In other words, there are four buffers for the physical link into which a data packet can be stored. In the present example, each virtual channel has its own distinct rank (e.g., 0, 1, 2 or 3). In the case of a flattened butterfly, at least 2 virtual channels should be employed. There are N! (N factorial) different (unique) orderings for the virtual channels. Any of them may be selected. However, once one particular ordering has been selected, it should be followed going forward to avoid deadlock.
[0052] In one example, the turn rule may be violated so long as the packet is routed only to monotonically increasing virtual channel numbers. By way of example, assume the present virtual channel=1. Here, if the turn rule would result in no valid paths along virtual channel 1 , then a route in violation of the turn rule may be selected using virtual channel 2 . Following turns would use virtual channel 2 so long as the turn rule is not violated. Subsequently, if no valid paths are available using virtual channel 2 , then a path violating the turn rule may be selected using virtual channel 3 .
[0053] In an alternative example, the turn rule may be violated so long as the packet is routed only to monotonically decreasing virtual channel numbers. By way of example, assume the present virtual channel=1. Here, if the turn rule would result in no valid paths along virtual channel 1 , then a route in violation of the turn rule may be selected using virtual channel 0 . Following turns would use virtual channel 0 . Thus, the turn rule may be violated using monotonically increasing virtual channel numbers or monotonically decreasing virtual channel numbers. In this situation, only one of these two options may be employed. The network may not vary between the two options without potentially resulting in a deadlock situation.
[0054] As noted above, aspects of the invention may be incorporated in different network configurations. In fact, deadlock may be prevented on any network topology in which each switch has a distinct identifier when incorporating aspects of the invention. By way of example, a two-dimensional mesh architecture such as in FIG. 1 or other two-dimensional architecture such as a torus may be in used. Other multidimensional architectures may also be employed, such as butterfly networks and flattened butterfly networks.
[0055] In one example, every node in the network is assigned an N-dimensional coordinate. There are N axes in the network. Here, in a mesh-type example, the coordinates differ by 1 in adjacent nodes. In other words, each switch connects to every other switch whose coordinates differ on a single axis. Each hop between switches replaces one coordinate.
[0056] FIG. 5 illustrates a 5 dimensional switch 300 . In this example, the switch 300 has 36 bidirectional ports, including 6 ports for hosts. As shown, each link to a neighboring switch differs in a single coordinate.
[0057] During operation, the switch 300 may receive an input packet from any of the connected hosts or from any of the other switches connected on remaining ports. In most cases, the number of physically minimal routes between two switches that differ in j digits is j! (j factorial). The number of permissible routes according to the aforementioned turn rule is less, with a lower bound of (j/2)! 2 .
[0058] For example, consider the minimal routes under the turn model in a 4-dimension flattened butterfly between the switches with addresses (1,2,3,4) and (4,3,2,1). The following routes are legal:
[0059] (1,2,3,4)->(1,2,2,4)->(1,2,2,1)->(4,2,2,1)->(4,3,2,1)
[0060] (1,2,3,4)->(1,2,2,4)->(1,2,2,1)->(1,3,2,1)->(4,3,2,1)
[0061] (1,2,3,4)->(1,2,3,1)->(1,2,2,1)->(4,2,2,1)->(4,3,2,1)
[0062] (1,2,3,4)->(1,2,3,1)->(1,2,2,1)->(1,3,2,1)->(4,3,2,1)
[0063] However, the other twenty possible paths of minimal length contain impermissible turns, such as:
[0064] (1,2,3,4)->(4,2,3,4)->(4,3,3,4)->(4,3,2,4)->(4,3,2,1)
[0065] As can be observed in this example, all of the legal minimal routes in the same virtual network between some pair of switches must pass through the switch whose coordinates are the minima of the corresponding coordinates of the source and destination endpoint addresses. This is (1,2,2,1) in the example above.
[0066] Aspects of the invention may be employed with different types of computer networks. These include distributed systems having hosts and nodes that may be located in numerous physical locations. By way of example, a network may include one or more datacenters coupled together, with hosts comprising different servers within a datacenter or among separate datacenters. The invention may also be employed in multiprocessor computer systems such as chip multiprocessors.
[0067] FIG. 6 illustrates an exemplary chip multiprocessor architecture 400 for use with aspects of the invention. As shown, the architecture includes 64 processors (P 0 . . . P 63 ) arranged in a mesh-type configuration at nodes 402 . The processors at adjacent nodes 402 in the mesh are directly linked to one another via connections 404 . For instance, processor P 9 is connected to processors P 1 , P 8 , P 10 and P 17 . While a mesh architecture is shown, other architectures may be used in accordance with aspects of the invention.
[0068] The processors along the top (P 0 . . . P 7 ) and bottom (P 56 . . . P 63 ) nodes of the mesh may be directly linked to respective memory controllers 406 . As shown in this example, four processors 402 connect to each memory controller 106 . In addition, each memory controller 406 couples to a physical memory 408 . The remaining processors may communicate with the memory controllers 406 through one or more intervening nodes 402 .
[0069] Packet routing may be accomplished in architecture 400 in the same manner as described above. So long as the turn rule is not violated, namely no turns either when I(A)<I(B)>I(C), or when I(A)>I(B)<I(C), deadlock will be avoided. A chip multiprocessor architecture with multiple virtual channels may also use an otherwise impermissible turn to signal a point of transition to a higher-numbered (or lower-numbered) virtual channel. Here, as above, the turn rule may be violated using either monotonically increasing virtual channel numbers or monotonically decreasing virtual channel numbers.
[0070] Although aspects of the invention herein have been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the invention as defined by the appended claims. | Aspects of the invention pertain to routing packets in a computer system while avoiding deadlock. A turn rule is set according to unique identifiers associated with switches in the system. Numeric values of switches in possible turns are compared to determine whether a turn is permissible. The rule applies to all nodes in the system. The rule may be violated when using virtual channels. Here, a violation is permissible when using monotonically increasing virtual channel numbers or monotonically decreasing virtual channel numbers. Alternatively, the violations of the turn rule may be allowed if they force a packet to change to a later virtual channel in some fixed ordering of virtual channels. Deadlock can thus be avoided in many different types of architectures, including mesh, torus, butterfly and flattened butterfly configurations. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation application of U.S. Ser. No. 11/865,423, filed Oct. 1, 2007, now U.S. Pat. No. 7,361,025, which is a divisional application of U.S. Ser. No. 11/365,366, filed Mar. 1, 2006, now U.S. Pat. No. 7,331,796, which claims the benefit under 35 U.S.C. §119(e) of the filing date of U.S. Provisional Patent Application No. 60/715,261; filed Sep. 8, 2005; the disclosures of which are incorporated herein by reference in their entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This invention was made with United States Government support under Contract No. NBCH3039004, DARPA, awarded by the Defense, Advanced Research Projects Agency, whereby the United States Government has certain rights in this invention.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the provision of novel and unique Land Grid Array (LGA) interposers, which incorporate the structure of metal-on-elastomer hemi-torus and other geometrically configured electric contacts to facilitate an array of interconnections between diverse electrical components. The invention is further concerned with a method of producing the inventive LGA interposers.
Land Grid Array (LGA) interposers, by way of example, provide an array of interconnections between a printed wiring board (PWB) and a chip module, such as a Multi-Chip Module (MCM), among other kinds of electrical or electronic devices. LGA interposers allow connections to be made in a way which is reversible and do not require soldering as, for instance, in ball grid arrays and column grid arrays. Ball grid arrays are deemed to be somewhat unreliable on larger areas because the lateral thermal coefficients of expansion driven stresses that develop exceed the ball grid array strength. Column grid arrays hold together despite the stresses but are soldered solutions and, thus, do not allow for field replaceability, which is important because it saves the customer or user significant costs in the maintenance and upgrading of high-end computers for which LGAs are typically used.
2. Discussion of the Prior Art
The basic concept of utilizing LGA interposers to provide an array of electrical connections is well known in the technology. In this connection, reference may be made in particular to Hougham, et al., U.S. Patent Publication No. 2005/0106902 A1, which is commonly assigned to the assignee of this application, and the disclosure of which is incorporated herein by reference in its entirety. This publication describes LGA interposers which define structure consisting of metal-on-elastomer type electrical contacts, wherein a compliant contact consists of an elastomeric material structural element partially coated with an electrically conductive material, preferably such as a metal, so as to form the intended electrical contact. However, there is no disclosure nor suggestion of a compliant contact of an LGA interposer type providing multiple points of electrical contact for each gridpoint in a configuration, such as is uniquely provided by the present invention.
Johnescu, et al., U.S. Patent Publication No. 2005/0124189 A1 discloses an LGA—BGA (Land Grid Array—Ball Grid Array) connector housing and electrical contacts which, however, do not in any manner disclose the novel and inventive LGA interposer metal-on-elastomer structure as provided for herein.
Similarly, DelPrete, et al., U.S. Pat. Nos. 6,790,057 B2 and 6,796,810 B2; and Goodwin, et al., U.S. Pat. No. 6,293,810 B2, describe various types of elastomeric electrical contact systems and devices which, however, do not at all disclose the features and concept of the present inventive metal-on-elastomer LGA interposers and arrays pursuant to the present invention.
SUMMARY OF THE INVENTION
Metal-on-elastomer type LGA contacts, as described hereinabove, have been previously described in Hougham, et al. in which a compliant contact consists of a structural element of a non-conductive elastomer that is coated on a part of its surface with electrically conductive material, which resultingly forms the electrical connection. However, a compliant contact with multiple points of electrical contact for each gridpoint is only disclosed by the present invention, wherein several specific geometries and variants are also described. Among these, a hemi-torus shaped element, such as being similar in shape to one-half of a sliced donut in transverse cross-section) may be oriented concentrically with respect to a via (or proximate thereto), the latter of which passes through an insulating carrier plane to the other side thereof. Metal is deposited onto the external portions of the hemi-toroidal elastomer element in order to form a multiplicity of electrically conductive contacts.
There are two general instances of LGA interconnects made with hemi-toroidally shaped, or other kinds of structural contact elements constituted of elastomeric materials. In the first instance, holes or vias in an insulating carrier plane would first be filled with metal to form solid electrically conducting vias with a surrounding pad or dogbone pad. Onto these pads would be molded both top and bottom elastomeric LGA bodies possessing various shapes, for example, hemi-toroidal. Then in a final step, metal strips would be deposited from the via pad on each side up and over the apex or uppermost ridge of the elastomeric hemi-torus. As illustrated in the drawings, this would then form a continuous electrical path from the highest point on the top hemi-torus shape to the lowest point on the bottom hemi-torus shape at several points for an individual I/O.
In the second instance, the insulating carrier is initially unmetallized with open holes on the desired grid pitch. Then, the top and bottom elastomeric bodies, for instance, hemi-toruses are molded and metallization follows to form the electrically conducting path, as illustrated hereinbelow. In case that during molding, the open hole in the insulator were inadvertently (or purposely) filled with elastomer, (e.g. siloxane), this can be removed in a controlled fashion by a coring or punch step to open a continuous pathway from the top surface to the bottom surface. Metallization can then be deposited on the exposed surface, which is produced thereby in a desired pattern so as to form the electrically conductive pathway.
In addition to the standard two-sided LGA interposer, i.e., on both sides of an insulating carrier phone, a one-sided compliant contact is also generally known in the art, and referred to as a “hybrid” LGA in which the contacts are soldered (ball-grid-array or BGA) to the circuit board but form a compression connection with the module, as in Jobnescu, et al., this frequently being referred to as a “hybrid BGA/LGA” or a “hybrid LGA/BGA” interposer.
There are several types of hybrid BGA/LGA's commercially available; however, the present invention describes a new type of hybrid BGA/LGA combining a metal-on-elastomer hemi-toroidally shaped top or upper contact with a solderable (BGA) bottom or lower contact. This provides significant advantages over existing technologies, and examples thereof are presented hereinbelow.
In one preferred embodiment, an insulating carrier plane with regularly spaced through-holes is treated to create a metal pad on top to fill the holes with electrically conducting metal for a through via, and a bottom surface, for example, by electroplating followed by photolithography. This produces a bottom surface with a pad for a BGA connecting to a circuit board. Then molded onto the top surface is a hemi-toroidal shape of an elastomeric material, such as siloxane rubber. The hemi-torus is located concentric to the metal via pad and surrounds it either fully or partly so that the elastomeric inside edge of the hemi-torus either touches the metal via and pad or lies outside the boundary of the via and pad. Then, metal is deposited to form a path of a continuous electrical connection leading from the top of the elastomer hemi-torus to the pad, which connects to the electrically conducting via to the bottom side of the insulating carrier plane creating a continuous conductive pathway from top to bottom. The metal on the elastomer may be distributed over the entire surface, or fabricated to consist of one or more strips connecting the top of the hemi-torus to the via pad. In a preferred embodiment there can be employed three strips, separated by 60 degrees from one another, although other quantities and spacing are shown herein. All of the strips start at the top of the torus, or slightly on the outside edge, and terminate on the pad in the center, this then providing multiple contact points, which is deemed electrically desirable.
Entrapment of air in the center of the hemi-torus is of concern as it could interfere with reliable seating of the electrical contact in compression. This potential concern can be mitigated by forming an opening or venting slit in the side of the torus during or after molding. Alternatively, any concern about entrapped air can be overcome by making the metal strips which extend over the top of the hemi-torus thick enough to extend over the elastomer surface, so that the gap produced between the uncoated area of the hemi-torus and the module bottom when the metal is in contact with the module bottom provides sufficient venting to allow a facile escape of air from the center of the hemi-torus upon actuation.
Another advantage to having multiple discontinuities in the hemi-torus shape resides in that each segment with its metal strip contact can move independently and better accommodate or compensate for non-uniformities in the mating surfaces.
The hemi-toroidal shape of the interposer can be molded from a compliant (rubbery) material onto each I/O position in an array, and metal strips are fabricated on the top surface of this shape so that they will provide multiple electrical pathways from a single chip module pad to a single printed circuit board pad. When this compliant hemi-torus is thus metalized, and preferably provided with discontinuities in the donut wall so that air would not be trapped preventing good contact, and provided that the compliant button stays well adhered to the insulating substrate or plane by virtue of anchoring holes, surface roughening, or surface treatments or coatings, then a uniquely functioning LGA is readily produced.
A structure pursuant to the invention possesses another advantage. For modules or PCBs that have solder balls or other protruding conductive structures, the LGA interposer array can be actuated into the module/PCB sandwich without the need for any separate alignment step or alignment structures. The ball will nest in the hemi-torus structure and center and stabilize itself with respect to any lateral motion in the x-y directions.
This provides another advantage which may sometimes be invoked, in that a module, which has had solder balls attached thereto, it in preparation for an ordinary BGA solder reflow step could instead be redirected on the assembly line for utilization in an LGA socket. Thus, a single product number part (balled module) could be used in two separate applications: 1) BGA soldering and 2) LGA socketing.
Such torus structures could be made by molding where the molds are made by drilling or machining with a router-like bit. Alternatively, it could be made by chemically or photoetching of the mold material utilizing a mask in the shape of a torus structure. The mask could be made by photolithography directly on the mold die or could consist of a premade physical mask (such as from molybdenum sheet metal) that was separately formed by photolithography and then applied to the mold die.
Another embodiment of this invention utilizes a hemi-torus that has been divided into three or four sections, each of which have been metalized to provide separate electrical paths, and whereby each section can respond mechanically independently when contacted with a pad or solder ball and can thus more reliably form a joint. Moreover, preferably a small space between these sections is created to allow gas to escape freely.
Pursuant to yet another embodiment, a number of the divided sections of a single hemi-torus can be made taller to provide a lateral stop for the case when a balled module is loaded preferably from one side thereof.
According to another embodiment, a wall shape of the sectionally-divided hemi-torus curves back in and under to form a nest so that when a solder ball is brought into contact therewith, it can be pressed down into the nest and snapped into place, or the shape could be curved simply to best nest a solder ball held in place there against.
As described in another embodiment, the I/O consists of multiple hemi-toroidal conic sections or domes that are fabricated into a group to service a single I/O. Each of these domes is metalized separately so that when contact is made with a module pad, redundant electrical paths are formed. The different contacts can also act independently mechanically thus being better able to accommodate local non-uniformities. A further modification would be to make a portion of the hemi-toroidal domes in such a group higher in the z-direction, thus providing a mechanical stop for cases where a balled module is loaded in part from one side, and thus able to constitute an alignment feature.
In the above embodiments, the structures and methods described can be applied to either single sided compliant LGAs (aka hybrid LGA), i.e., on one side of the carrier plane only, or to double sided LGAs. Further, they can be applied to hybrid cases where the corresponding metal pad is either directly in line with the center axis of the upper contact or may be offset therefrom:
As shown in another embodiment, the compliant structures are in a linear form rather than based on a torus or groups of domes. From a linear compliant bar, or alternatively a sectioned bar, multiple contact strips can be formed for each I/O. Further, the multiple metal contact strips could be located on different linear bars for a given I/O. Various arrangements could include multiple metal strips on the same linear section of compliant material, or on different adjacent linear bars in a line, or on different linear bars on either side of the central I/O via.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference may now be made to the following detailed description of preferred embodiments of the invention, taken in conjunction with the accompanying drawings; in which:
FIG. 1 illustrates generally diagrammatically, a metal-on-elastomer LGA interposer array, shown in a transverse sectional view, pursuant to a first embodiment of the invention;
FIG. 2A illustrates a modified embodiment of the metal-on-elastomer LGA interposers, shown in a transverse enlarged sectional view;
FIG. 2B illustrates a perspective view of the LGA interposer array of FIG. 2A ;
FIG. 3 illustrates a perspective view of metal-on-elastomer LGA interposers;
FIG. 4 illustrates a transverse enlarged cross-sectional view of the LGA interposers of FIG. 3 ;
FIG. 5 illustrates a perspective view of a further embodiment of an LGA interposer array;
FIG. 6 illustrates a transverse enlarged cross-sectional view of the interposer array of FIG. 5 ;
FIG. 7 illustrates a perspective view of a further embodiment of a metal-on-elastomer LGA interposer array;
FIG. 8 illustrates a transverse enlarged cross-sectional view of the LGA interposer array of FIG. 7 ;
FIG. 9 illustrates a perspective view of a still further embodiment of a metal-on-elastomer LGA interposer array;
FIG. 10 illustrates a perspective view of a further embodiment of an LGA interposer array, which is similar to that illustrated in FIG. 7 ;
FIG. 11 illustrates a further embodiment in a perspective view of an LGA interposer array showing a modification relative to that shown in FIG. 10 ;
FIG. 12 illustrates a perspective representation of a further LGA interposer array, which is somewhat similar to that of FIG. 10 ;
FIG. 13 illustrates a transverse enlarged cross-sectional view of the LGA interposer array of FIG. 12 ;
FIG. 14 illustrates a perspective view of a further embodiment of an LGA interposer array;
FIG. 15 illustrates a transverse enlarged cross-sectional view of a portion of the LGA interposer array of FIG. 14 ;
FIG. 16 illustrates a transverse enlarged cross-sectional view of an embodiment which is somewhat similar to that of FIG. 14 ;
FIG. 17 illustrates a perspective view of a further embodiment of an LGA interposer array;
FIG. 18 illustrates a transverse enlarged cross-sectional view of the LGA interposer array of FIG. 17 ;
FIG. 19 illustrates a perspective view of a modified embodiment of the LGA interposer array, relative to that shown in FIG. 17 ;
FIG. 20 illustrates a transverse enlarged cross-sectional view of a portion of the LGA interposer array of FIG. 19 ;
FIG. 21 illustrates a modified arrangement consisting of linear bars of metal-on-elastomer contacts shown in a perspective representation;
FIG. 22 illustrates a transverse enlarged cross-sectional view of a portion of the LGA interposer arrangement of FIG. 21 ; and
FIGS. 23-25 illustrate, respectively, alternative-processing concepts for providing the LGA interposer arrays in accordance with various of the embodiments described hereinabove.
DETAILED DESCRIPTION OF THE INVENTION
In the detailed description of the various embodiments, elements or components, which are substantially similar or identical, are designated with the same reference numerals.
Referring to the embodiment of the metal-on-elastomer LGA interposer array 10 , as illustrated in FIG. 1 of the drawings, there are shown a plurality of the interposers 12 in the form of hemi-toroidally shaped elements or so called buttons (generally simulating the shape of a transversely sliced donut). Each of the LGA interposer buttons 12 includes a plurality of circumferentially spaced flexible strip-like metal elements 14 forming electrical contacts which reach from the topmost surface 16 of each respective LGA button 12 to the via 18 which extends through an insulating carrier pad 20 on which the LGA interposer buttons are mounted, and down through the center of the LGA buttons so as to connect to a conductive pad 22 which surrounds through the through via on both sides of the carrier 20 , and extends out along the insulating carrier surface beneath the LGA so as to make electrical contact at the other side or the lowermost end surface 24 of the inversely positioned lower LGA interposer buttons 26 . The electrically-conductive flexible metal elements are primarily strips 14 which extend from the uppermost end of the respective upper LGA interposer buttons 12 inwardly into an essentially cup shaped portion extending to the hole or via 18 formed in the pad 22 .
Consequently, by means of the pads 22 , which are constituted of electrically conductive material or metal and which surround each of the through vias 18 formed in the dielectric material insulating carrier plane 20 , these contact the ends of each of the metal strips 14 , which extend along the external elastomeric material surface of each respective LGA hemi-toroidally shaped interposer structure or button 12 . Accordingly, electrical contact is made from the uppermost or top end of each respective LGA interposer button to the lowermost end 24 of each of the opposite sided LGA interposer buttons 26 at the opposite or lower side of the insulating carrier plane 20 .
With regard to the embodiment illustrated in FIG. 2A of the drawings, wherein the electrical elements 30 consisting of the strips positioned on the top surface 16 of the respective LGA interposer buttons 12 extend towards the through via 18 , in this instance, there is no electrically conductive pad present as in FIG. 1 , but rather the metallic or electrically conductive strips 30 forming the flexible metal contacts extend from the uppermost end 16 of the upper LGA interposer buttons 12 down through the via 18 , the insulating carrier plane 20 to the lowermost ends or apices 24 of the lower inverted LGA buttons 26 on the opposite or bottom side of the structure 10 .
In essence, in both embodiments, in FIGS. 1 and 2A , both the upper and lower LGA interposer buttons 12 , 26 are mirror images and are symmetrical relative to each other on opposite sides of the insulating carrier plane 20 . With regard to FIG. 2B of the drawings, this illustrates primarily a perspective representation of the array of the upper LGA interposer buttons 12 positioned on the insulating carrier plane 20 .
Reverting to the embodiment of FIG. 3 of the drawings, in this instance, the flexible metal electrical contacts 34 , which are positioned so as to extend from the upper ends 16 of each of the respective LGA interposer buttons 12 through the via 18 in the insulating carrier plane 20 , as also represented in the cross-sectional view of FIG. 4 , are designed to have the electrical metal contacts forming a plurality of flexible strips 34 , which extend each unitarily from the upper ends 16 to the lower ends 24 of the hemi-torus shaped buttons 12 , 26 from above and below the insulating carrier plane 20 in a mirror-image arrangement. Hereby, the multiple, circumferentially spaced metal electrical contact strips 34 extend from the uppermost point on one side of the insulating plane to the lowermost point on the opposite side so as to form electrical through-connections at both upper and lower ends and, in effect, forming a reversible structure 10 .
As shown in FIG. 5 of the drawings, in that instance, each of the hemi-toroidally shaped interposer buttons 12 , 26 , which are essentially identical in construction with those shown in FIGS. 3 and 4 of the drawings, have the metal contacts 40 formed so that they extend in a common annular conductive sleeve structure 41 prior to continuing through the via 18 , which is formed in the insulating carrier plane 20 to the upper and lower ends 16 , 26 of the LGA interposer buttons 24 . In FIG. 6 of the drawings, contacts 40 separate only into separated strip-like portions 42 at the extreme uppermost and lowermost ends of the LGA interposer buttons 12 , 26 and then join together into the essentially annular structure 44 extending through the via 18 formed in the insulating carrier plane 20 .
Referring to the embodiment of FIGS. 7 and 8 of the drawings, these illustrate essentially a structure 50 wherein LGA interposer buttons 12 are arranged only on the upper surface 52 of the insulating carrier plane 20 in a manner similar to FIG. 1 of the drawings, and wherein the conductive strips 14 contact metallic or electrically-conductive pads 54 extending respectively through each of the through vias 18 formed in the insulating carrier plane 20 . The lower surface of each metal pad 54 , in turn, may have a solder ball 56 attached thereto in preparation for a subsequent joining, as is known in the technology.
As shown in the perspective representation of FIG. 9 of the drawings, in that instance, the LGA interposer array structure 60 , which is mounted on the insulating carrier plane 20 , is similar to that shown in FIGS. 7 and 8 of the drawings; however, a slit 62 is formed in the elastomeric material of each LGA interposer button 12 , communicating with the interior 64 thereof, and with the through via 18 , which is formed in the insulating carrier plane 20 , so as to enable any gasses or pressure generated to vent from the interior thereof to the surroundings.
FIG. 10 of the drawings is also similar to the structure shown in FIG. 7 , however, in this instance, each elastomeric interposer button 12 has a plurality of slits 62 or discontinuities formed in the annular toroidally-shaped walls thereof, preferably intermediate respective flexible metal strips 14 , which are located on the upper and inward downwardly extending surface of each elastomer buttons, so as to enable each separate segment 68 to be able to resiliently or flexibly respond to changes or irregularities in the topography of elements contacting the LGA interposer buttons 12 . Also, each segment 68 between each of respective metal contact strips 14 may respond mechanically or independently, so as not to only accommodate differences in topography with a mating surface or differences in the shape of mating solder balls, but in cases where a solder ball will be pressed against the toroidal contacts to produce an electrical connection. In effect, this will enable a mechanical or physical compensation for encountered differences in contact surfaces.
With regard to the embodiment of FIG. 11 of the drawings, which is somewhat similar to FIG. 10 , in that instance, at least one or more of the segments 68 , which are separated by the intermediate slits extending through the LGA interposer buttons are different in height, so as to have some of the segments 70 higher than others in a z- or vertical direction relative to the plane of the insulating carrier plane 20 . In this instance, two segments 68 of the four independent segments of each respective LGA interposer button 12 are shown to be lower in height than the other segments 70 .
With regard to FIG. 12 of the drawings, in this instance, the array structure 74 of the hemi-toroidal LGA interposer buttons 76 , which are mounted on the insulating carrier plane 20 , the opposite or lower side 78 of which has solder balls 80 connected to electrically-conductive pads 82 extending through the vias 18 , has the centers 84 of the respective LGA interposer buttons 76 , which have electrical strip-like contacts 88 extending downwardly, as shown in FIG. 13 , have a contoured inner wall configuration 90 , which allows for nesting or a snap-fit with a solder ball (not shown), which may be brought into engagement therewith. In this instance, FIG. 13 showing the cross-sectional representation of FIG. 12 , illustrates the knob-shaped interior sidewall profile 90 of the compliant interposer button with the separate metal contact strips 88 extending upwardly along the interior of wall 90 to the topmost end 92 of each respective LGA interposer button 76 .
As illustrated in the embodiment of FIG. 14 of the drawings, in this instance, as also shown in cross-section in FIG. 15 ; multiple metal strip contacts 88 extend from the top surfaces of the compliant LGA button structure 100 , passing over the top surfaces 102 and extending down into the center part of the hole 104 provided in each interposer button 106 , and meeting with a common pad-shaped metal conductor 108 , which extends along the upper surface 110 of the insulating carrier plane 20 under the button in contact with strips 88 and outwardly until reaching a via 112 , which extends the metal pad downwardly through the insulating carrier plane 20 and along the lower surface 114 thereof, so as to contact solder balls 116 . This is illustrated in the cross-sectional representation of FIG. 15 of the drawings, which also shows a filled injection tube 120 extending through the insulating carrier plane 20 and a residue break off point 122 , where an elastomer portion was separated from an injection port on a mold forming the entire LGA button structure. This embodiment, showing the filled injection tube for the plastic material, is adapted for the method in which the injection molding of elastomeric material is implemented from the bottom side of the insulating carrier plane 20 .
As shown in FIG. 16 of the drawings, which is essentially similar to the embodiment of FIG. 15 , in that instance, this illustrates a filler injection tube, the mold (not shown) forming the LGA button structure is implemented by injection molding from the top side of the mold, and a residual mass of elastomer 132 can be ascertained extending from the side 134 of the elastic LGA button structure 100 from which it was separated at the injection port of a mold.
Also indicated in FIG. 16 are two types of anchoring holes in the insulating carrier plane 20 , wherein one hole 136 extends all the way through to the other side thereof, and wherein a blob 138 of residual excess molding material penetrates slightly beyond the bottom surface of the insulating carrier plane 20 . Another type of anchoring hole or cavity 140 does not extend fully through the insulating carrier plane 20 , but is formed as a depression in the top surface of the latter, so as to mechanically anchor the elastomeric material of each LGA interposer button to the structure or plane 20 .
Reverting to the embodiment of FIGS. 17 and 18 of the drawings, these show another aspect of providing an LGA interposer array 150 on an insulating carrier plane 20 , wherein a multiple of LGA interposer buttons 152 of essentially conical configurations and their electrical metallic strip contacts 154 , which extend over the topmost ends 156 thereof, service a common I/O electrical contact 158 in the form of a pad on the upper surface of plane 20 . In this instance, the structure incorporates an electrically conductive via 160 extending through the insulating carrier plane 20 , shown in a center of a group of four LGA interposer buttons 102 , as a common meeting point of the metal contact strips 154 on pad 158 , which extend from respectively one each of the top of each LGA button down the side thereof and into the via metallurgy of the structure, towards the bottom of plane 20 , as shown in cross-section in FIG. 18 of the drawings.
Reverting to the embodiment of FIGS. 19 and 20 of the drawings, which is quite similar to the embodiment of FIGS. 17 and 18 , in that instance, the primary distinction resides in that at least one or two of the LGA interposer buttons 152 of a respective group thereof has or have a height which differs from the remaining interposer buttons of that group. For example, two or more buttons 152 of each group may be taller than the remaining buttons 164 of that group (of four buttons) in order to essentially create a lateral stop mechanism for a side loading of a module, through such groupings of LGA interposer buttons in respective arrays. In essence, the different heights in the LGA interposer button groups enable a module with an associated solder ball to be brought into contact and aligned by means of lateral insertion, rather than only vertical insertion, wherein the higher LGA interposer buttons provide stops for the solder balls in order to register with the essentially hemi-toroidally shaped elastomeric contacts.
Reverting to the embodiment of FIGS. 21 and 22 of the drawings, in this instance, there is provided an LGA interposer array 170 arranged on an insulating carrier plane 20 , wherein multiple points of contact for each I/O are provided by means of linear bars of elastomeric LGA interposers 172 . This provides a compliant structure on which a plurality of spaced metallic electrical contact strip elements 174 may be positioned so as to extend from the top 176 of each respective interposer bar 172 both above and below the insulating carrier plane 20 , as shown in FIG. 22 , into electrically sleeve-like conductive vias 178 formed extending through the insulating carrier plane 20 in contact with respective metal strip contacts 180 above and below the insulating carrier plane 20 . In that instance, the metal contact strips 180 may be formed with different shapes, such as one typical contact joining from two-separate ships 182 into a single common strip 184 near the top, as clearly illustrated in FIG. 21 , or joining further down near the via extending through the carrier plane to the other side. Furthermore, three or more contact points for each I/O may be provided and different types of contact elements may be utilized along the bar whereby some types may be more suitable for conduction of signals and others for high amperage power feeds.
As illustrated in FIGS. 23-25 , there are shown alternate process flows for a balled module, wherein a balled module zoo, as shown in FIG. 23 , can be directed either towards a solder reflow line for normal BGA connection to a PWB, as illustrated in FIG. 24 , or alternatively, to an LGA interposer assembly 210 where it is assembled by means of a hemi-toroidal LGA and PWB (wiring board) under pressure to make a field replaceable unit, as shown in FIG. 25 of the drawings.
With regard to the configurations of the LGA interposer buttons, these may be of elastic structural members, which are conical, dome-shaped conic sections or other positive release shapes, such as roughly cylindrical or hemispherical, hemi-toroids, and wherein the metal coating forming the electrically conductive contact members or strips terminate at the apices of each of the multiple buttons.
Moreover, the elastomeric material, which is utilized for each of the LGA interposer buttons or for the linear shaped elastic structural member (as shown in FIGS. 21 and 22 ) may be constituted of any suitable molded polymer from any rubber-like moldable composition, which, for example, among others, may consist of silicon rubber, also known as siloxane or polydimethylsiloxane (PDMS), polyurethane, polybutadiene and its copolymers, polystyrene and its copolymers, acrylonitrile and its copolymers and epoxides and its copolymers.
The connectors of the inventive LGA structure may be injection molded or transfer molded onto an insulating carrier plane 20 , and may serve the purpose of mechanically anchoring the contact to the insulating carrier plane and in instances can provide a conduit for the electrical connections which pass from the top surface of the connector to the bottom surface thereof.
In addition to connecting chip modules to printed circuit boards, the arrays of the LGA interposer buttons or linear structure may be employed for chip-to-chip connection in chip stacking or for board to board connections, the contacts may be of any shape and produced by injecting the elastomer in the same side as where the elastomer contact will be anchored to the insulating carrier by a hole or holes or vias, which extend through the insulating carrier or by any cavity edge formed into the surface of the insulating carrier.
In essence, the molding of the elastomeric material component or components, such as the hemi-toroidal interposer or interposers may be implemented in that the elastomeric polymer material is ejected from the same side at which the interposer will be positioned on the insulating carrier plane, and will be anchored to the insulating carrier plane by means of a hole or holes, as illustrated in the drawings, which either extend completely through to the opposite side of the insulating carrier plane, or through the intermediary of a cavity which is etched or formed into the surface of the insulting carrier plane, which does not extend all the way through the thickness thereof, and wherein any cavity may have flared undercut sidewalls from maximum anchoring ability or by simple surface roughening of the insulating carrier plane. This is clearly illustrated in the embodiments represented in FIGS. 15 and 16 of the drawings.
While the present invention has been particularly shown and described with respect to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in forms and details may be made without departing from the scope and spirit of the present invention. It is therefore intended that the present invention not be limited to the exact forms and details described and illustrated, but fall within the scope of the appended claims. | A method of producing a land grid array (LGA) interposer structure, including an electrically insulating carrier plane, and at least one interposer mounted on a first surface of said carrier plane. The interposer possesses a hemi-toroidal configuration in transverse cross-section and is constituted of a dielectric elastomeric material. A plurality of electrically-conductive elements are arranged about the surface of the at least one hemi-toroidal interposer and extend radically inwardly and downwardly from an uppermost end thereof into electrical contact with at least one component located on an opposite side of the electrically insulating carrier plane. | 7 |
DESCRIPTION OF THE INVENTION
Technical Field
This invention relates to cartridges for holding and feeding ribbon for use in typewriters.
Background of the Invention
The feeding of typewriter ribbons in cartridges requires several things. The requirements range from the need for a mechanical mechanism which can be inserted into the cartridge or to engage the cartridge for feeding, which may become quite complex but which must be reliable, to the requirement that the drive mechanism be engaged with the periphery of the takeup spool in order to insure uniform feed of the ribbon to minimize ribbon waste, to cartridges which accommodate the mechanical feed drive and the engagement of the drive with the ribbon periphery.
With the addition of correction capability to a typewriter and the packaging of the correction media, tapes or ribbons, in cartridges, the complexity of ribbon drives and the associated complexity of cartridges has increased. It is necessary to be able to feed the ribbon in the ribbon cartridge without interfering with the correction media cartridge position or operation.
Electrical motor drives for feeding ribbon have increased with the reduction of the mechanical complexity of the print carrier of typewriters as the technology tends to move toward the daisy wheel type printer making room for the mass and size of the electrical motors, typically stepper motors, for ribbon feed. Electrical motors provide a number of advantages in that a stepper motor may then be commanded to provide either a variable amount of feed, depending upon the pitch of the type being typed, or may even provide a variable amount of feed within a single character set depending on the width of the characters in proportionally spaced printing. The use of electric motor drive such as a stepping motor requires that a fixed location be defined so that the cartridge may interface with the motor drive at a fixed point.
With a fixed interface point, a peripheral drive of the takeup spool necessitates the displaceability of the takeup spool to accommodate an increasing diameter of ribbon as the spool accumulates the used ribbon while insuring uniform feed increment of the ribbon during operation. Displaceable takeups must be, of necessity, simple, reliable and relatively inexpensive to be cost effective since the cartridges are designed to be disposable.
An example of a ribbon cartridge which has a moveable takeup spool but which does not have the ribbon spool drive member positioned within and a part of the cartridge is U.S. Pat. No. 4,302,118 to Schaefer, while a spring improvement for providing the bias force of the takeup spool against the driver and providing a yield in the spring with a flat rate force is described in U.S. Pat. No. 4,367,052 to Steger.
While both of these patents illustrate a moveable takeup spool to accommodate increased ribbon bulk as it is wound on the spool, neither one of these patents illustrates a cartridge which has a self-contained drive element engaged with the takeup spool and neither of the patents illustrates a spool carrier which has a stabilizing plane engaging a planar surface of the cartridge, thus minimizing the possibility of misalignment of the takeup spool and a diminished usage of the cartridge and its contained ribbon.
SUMMARY OF THE INVENTION
The advantages of the motor direct drive ribbon feed, such as the ease in directly connecting the cartridge to the drive, uniformity of ribbon feed, simplicity of the ribbon feed mechanism, and the ability to control the increment of feed are available by supporting a takeup spool on a spool carrier contained within the ribbon cartridge and adapting the spool carrier to slide within a predefined guiding channel in the cartridge. The carrier may slide to displace the takeup spool from the driver to accommodate a larger diameter disk of ribbon as it is accumulated on the takeup spool while the carrier takeup spool and ribbon disk are uniformly biased throughout its range of travel by a spring which exerts a constant force on the carrier.
Ribbon drive is provided by a spiked driver member which is meshed with takeup spool with the rate of feed fixed by the cartridge. The cartridge determines the rate of feed by the design of the receptacle which receives and engages the motor drive connection. Direct drive from the motor shaft to the spiked driver is used for a one time use ribbon while a planetary gear drive arrangement is used for multi-strike ribbon.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a partially cutaway top view of a ribbon cartridge incorporating the ribbon feed mechanism of the invention;
FIG. 2 is a bottom view of a drive connection to the ribbon feed driver;
FIG. 3 is a bottom view of an alternative embodiment of the drive connection to the ribbon feed driver;
FIG. 4 is an exploded isometric view of the ribbon feed drive mechanism and carrier for the takeup spool;
FIG. 5 is an isometric bottom view of the drive connection shown in FIG. 2; and
FIG. 6 is a bottom isometric view of the drive connection shown in FIG. 3.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawing, the ribbon cartridge 10 is illustrated. The cartridge 10 defines an interior chamber 12 which may contain a spool of ribbon 14. Extending outwardly from the cartridge are two arms 16 which support a span 18 of ribbon 20.
In order to take up the used ribbon 20, a takeup spool 22 is provided. In this particular instance, in FIG. 1, the takeup spool is cut away to a significant extent to expose and reveal other details of the cartridge.
Takeup spool 22 rotates on a short stub axle 24. Stub axle 24 is formed as a part of or attached to the spool carrier 26. Spool carrier 26 is formed as a flat planar member which has, in the preferred embodiment, notches 28 formed in the side thereof to aid in inserting the member into channel 30. Channel 30 is molded into the cartridge wall 32 and has formed therein tabs 34 which act to restrain the carrier 26 and contain its movement within the channel. Notches 28 are dimensioned such that the notch 28 will pass over tabs 36. The carrier 26 has formed into its end a tab 38 which is raised to permit the hooking of a spring 40 thereunder.
Spring 40 is formed by sharply bending a spring wire at its approximate midpoint to form two legs and then winding the ends of the wire into counter wound coils 42. Coils 42 are then engageable over molded hook restraints 44 formed as a part of the floor 32 of cartridge 10.
In positioning the spring 40, as shown in FIG. 1, the coils 42 must be partially unwound to hook over the restraints 44 and therefore resiliently act to recoil themselves and thereby move the carrier 26 and axle 24 toward the spiked driver 46. The spiked driver 46 is a cylindrical drive roller with sharp protrusions extending therefrom and engageable peripherally with the exterior of the takeup spool 22 or any ribbon wound thereon. The spiked driver is provided with a drive connection 52 which is supported in a journal surface 48 while the opposite end of the spiked driver 46 is supported by a small positioning shaft 50. The connection 52 is formed as a shell of a cylinder with a locating shaft 54 protruding coaxially with the shell and two spline members 56 formed in the outer shell of the connection 52. A gear or mating splined member is positionable over shaft 54 and engaging the splines 56 to provide the drive from the motor to the connection 52 and thence to the spiked driver 46. Associated with the spiked driver 46, either manufactured as a part thereof or attached and fixedly held thereto, is a knurled wheel 58. The knurling on the wheel 58 provides a finger engageable surface so that the ribbon takeup spool 22 may be rotated to accumulate any slack in the span 18 of the ribbon 20.
The connection 52 illustrated in FIG. 2 provides a one-to-one ratio of drive between the motor shaft rotation or the driving gear rotation and the spiked driver 46. This driving ratio is the desired condition for a single use type ribbon.
For multiple strike ribbons which permit a plurality of typing impact overlapped, the driving connection 60 illustrated in FIG. 3 is desirable. The driving connection 60 is a larger diameter cup with splines 62 formed on the interior cylindrical surface of the connection 60. A gear with appropriate spaced splines or teeth may be meshed with the splines 62 and will thus act as a planetary gear reduction system whereby the spiked driver 46, to which connection 60 is connected, will rotate a fraction of a revolution for each revolution of the motor shaft.
Referring again to the spring 40, as the spring member is extended by the translation of carrier 26 and axle 24 in response to an accumulation of used ribbon 20 on takeup spool 22, the coils 42 will be uncoiled. This uncoiling action will, of course, result in a force being exerted at the midpoint of the spring attempting to pull the carrier 26 against the direction it is being moved by the ribbon. As this force increases and the translation distance of the carrier increases, the coils 42 will continue to unwind. The material of the spring, a spring wire, is selected in size and properties to provide a relatively low elastic limit such that as the coil is uncoiled, the elastic limit of the material is exceeded and the tendency to attempt to recoil is reduced. This selection of the elastic limit tends to make the spring exert a constant force against slider 26 without regard to the amount of the distance that the slider has been displaced and the degree of uncoiling of the coils. Thus, the force exerted between the takeup spool 22 and the spiked driver 46 will remain substantially constant throughout the useful life of the cartridge.
OPERATION
The cartridge is operated by positioning it into an appropriate holder and insuring that the drive connection 52 or 60 is appropriately positioned over the drive gear of the ribbon feed mechanism which is powered by an electrical drive motor such as a stepping motor. The ribbon feed mechanism, upon activation, will rotate and cause to be rotated the connection 52 and/or 60 as appropriately installed, thereby causing the rotation of spiked driver 46 while engaged with the periphery of the ribbon disk 14 or the takeup spool 22 holding the ribbon disk 14. As the spool 22 is rotated, ribbon 20 will be pulled onto its periphery, thereby insuring that the ribbon 20 in span 18 is pulled across the span 18, thus presenting new ribbon 20 to the print point. As the diameter of the takeup spool 22 increases with the accumulation into the ribbon disk of ribbon 20, the engagement between the spiked driver 46 and the takeup spool 22 is broken as the takeup spool 22 is translated radially away from the spiked driver 46 as the ribbon disc on spool 22 grows. As the takeup spool 22 is forced away from the spiked driver 46, a similar forcing action occurs between the takeup spool 22 and the axle 24 of carrier 26. As carrier 26 is thus translated away from the spiked driver 46, spring member 40 is caused to extend through the uncoiling of coils 42 on the ends thereof. As the coils 42 uncoil and the material in the spring 40 is stressed beyond the elastic limit thereof, the force exerted on the carrier 26 remains substantially constant and is limited by the elastic limit of the spring material. When the cartridge 10 has exhausted its supply of ribbon 14 and all the ribbon has been accumulated on the takeup spool 22, the carrier 26 will have been translated to its maximum displacement position from the spiked driver 46 and the cartridge is then disposed of.
This design permits the positioning of a drive motor or ribbon feed drive connection immediately below the corner of the cartridge in such a way as to clear any correction material cartridge which may be married with it for insertion into the typewriter, while at the same time providing uniform ribbon feed and the potential for varying the feed increment for different pitches, with a simple feed mechanism. | The feeding of typewriter ribbons is improved by utilizing a cartridge carried driving element engaging the periphery of a translatable take-up spool where the driving element is driven by an interface connection with a driving member connected either directly or through a gear reduction train to a stepper motor. The simplified ribbon feed mechanism provides control over the increment of feed electronically as well as each ribbon cartridge carrying the appropriate gear reductions, if necessary, for different types of ribbons. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 13/349,794 filed Jan. 13, 2012, entitled M ETHOD OF F ORMING C ONDUIT R ECEIVING P ASSAGEWAYS IN A R EFRIGERATOR , which is a division of application Ser. No. 12/402,644 filed Mar. 12, 2009, entitled R EFRIGERATOR WITH M ODULE R ECEIVING C ONDUITS , which claims priority under 35 U.S.C. §119(e) and the benefit of U.S. Provisional Application No. 61/035,775 entitled R EFRIGERATOR W ITH S PACE M ANAGEMENT M ODULES , filed on Mar. 12, 2008, the entire disclosures of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a refrigerator and specifically a refrigerator door having a conduit including utilities for supplying electrical power or fluids to plug-in modules at one or more locations.
Currently designed refrigerators may include adjustable shelves and some optional accessories, such as ice makers and water dispensers, which can be part of the original equipment of the refrigerator or, in some cases, added on to specific modules pre-manufactured to accommodate such additional components. A refrigerator typically will have shelving in the door which can be adjustable but otherwise has very little ability to change the configuration of the refrigerator shelving either in the cabinet of the refrigerator or in the door. There exists a need, therefore, for a refrigerator which can accommodate new accessories in modular form at owner selected locations within a refrigerator and particularly in its door. In order to accommodate such flexibility, it would be desirable to provide a refrigerator having a modular architecture to provide specialized functions, new features, and flexibility to the consumer in selecting desired features.
SUMMARY OF THE INVENTION
In order to accommodate these desirable goals, a refrigerator door includes a conduit carrying utilities for the operation of different modules. The conduit includes one or more access ports with connectors at selected locations or adjustable locations in the refrigerator door for the easy installation of such modules.
The system of the present invention accommodates such a need by providing a hinged access door and a conduit mounted to the door for carrying at least one of an electrical conductor and a fluid transmission tube positioned within the conduit. At least one connector is positioned at a selectable location along the conduit and coupled to at least one of an electrical conductor and a fluid transmission tube. A module requiring at least one of electricity and a fluid for its operation is mounted to the door at a selected location in one embodiment and includes a module connector for mating with the connector for receiving the necessary utilities for operation of the module.
In another embodiment, a refrigerator access door includes at least one hinge for mounting the door to a refrigerator cabinet for opening and closing the door. A first conduit is mounted within the door for carrying at least one of an electrical conductor and a fluid transmission tube. At least one connector is coupled to a selectable location along the first conduit and to at least one of an electrical conductor and a fluid transmission tube. The system includes a second conduit mounted to an inner surface of the door and includes a connector for coupling the second conduit to the connector of the first conduit. The second conduit carries at least one of an electrical conductor and a fluid transmission tube and has at least one connector on the second conduit facing the interior of the cabinet and is coupled to at least one electrical conductor and fluid transmission tube in the second conduit. A module requiring at least one of electricity and a fluid from the second conduit for its operation includes a connector for mating with the connector of the second conduit when the module is mounted to the door at a selected location.
In a further embodiment, a refrigerator access door includes at least one hinge for mounting the door to a refrigerator cabinet for opening and closing the door. A conduit mounted to the door for carrying one of an electrical conductor and a fluid transmission tube includes at least one connector coupled to one or more selectable locations along the conduit and to one of an electrical conductor and a fluid transmission tube. A plurality of modules are provided for mounting to the door wherein at least one module requires at least one of electricity and a fluid from the conduit for its operation and wherein at least one of the modules includes a module connector for mating with at least one connector of the conduit when the module is mounted to the door at a selected location. At least one module includes a conduit and a second connector for coupling to a second module to supply one of electricity and fluid to or through the second module.
Such a modular construction allows the consumer an upgradable refrigerator with interchangeable modules which can easily be removed for service or replacement with a different module having newer features. These and other features, objects and advantages of the present invention will become apparent upon reading the following description thereof together with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view, partly broken away, of a refrigerator embodying the present invention;
FIG. 2 is a fragmentary perspective view of a refrigerator door, such as shown in the refrigerator of FIG. 1 , showing one step of its manufacturing process;
FIG. 3 is a fragmentary perspective view of the door shown in FIG. 2 , shown during a second step of its manufacturing process;
FIG. 4 is a perspective view of the door shown in FIGS. 2 and 3 , shown during a third step of its manufacturing process;
FIG. 5 is a fragmentary perspective view of the door shown during a subsequent step of the door manufacturing process;
FIG. 6 is a fragmentary perspective view of an alternative embodiment of the invention in which a conduit is positioned within a door, such as shown in FIGS. 2-5 ;
FIG. 7 is a fragmentary perspective view of an alternative embodiment in which a conduit is positioned on the inner liner of a door;
FIG. 8 is a fragmentary perspective view, partly exploded, of a refrigerator embodying the present invention, in which a plurality of modules are shown together with a plurality of connectors on the refrigerator door;
FIG. 9 is a fragmentary perspective view, partly exploded, of a refrigerator door with an alternative embodiment of a connection port for a module coupled to the door for receiving utilities;
FIG. 10 is a fragmentary perspective view of an alternative embodiment of connection ports in a door showing a plurality of connecting ports and connectors for multiple modules;
FIG. 11 is a fragmentary perspective view of a quick disconnect connector which can be employed in any of the embodiments of the present invention for supplying two different fluids between a module and a refrigerator door;
FIG. 12 is a fragmentary perspective view of a quick disconnect coupling for supplying a single fluid between a module and the refrigerator door;
FIG. 13 is a fragmentary perspective view of a quick disconnect electrical coupling which can be used in the system of the present invention;
FIG. 14 is a fragmentary perspective view of a refrigerator door showing an alternative embodiment of the present invention wherein a conduit is centered inside the liner of the door;
FIG. 15 is an enlarged fragmentary cross-sectional view, taken along section line XV-XV, of the construction of FIG. 14 ;
FIG. 16 is a perspective view of a door, partly broken away, showing an alternative mounting of a conduit;
FIG. 17 is an enlarged vertical cross-sectional view, taken along section line XVII-XVII of FIG. 16 ;
FIG. 18 is a horizontal cross-sectional view of an alternative embodiment of the mounting of a conduit in a refrigerator door;
FIG. 19 is perspective view of a refrigerator door showing a conduit with multiple connectors and an accordion-type cover for exposing one or more connectors for use in coupling a module thereto;
FIG. 20 is an enlarged section of area XX of the door shown in FIG. 19 ;
FIG. 21 is a perspective view of a refrigerator door including a sliding connector coupled to a conduit for providing variable positioning of a connector for a module;
FIG. 22 is an enlarged perspective view of the area XXII shown in FIG. 21 ;
FIG. 23 is a perspective view of a refrigerator door showing an alternative embodiment of an electrical connector for a module in which a spring-loaded slideable connector is mounted within a track of the conduit for providing electrical power for modules which can be placed at various locations within the refrigerator door;
FIG. 24 is an enlarged fragmentary perspective view of the structure shown in the encircled area XXIV in FIG. 23 ;
FIG. 25 is a perspective view of a refrigerator door showing an alternative arrangement for supplying multiple connecting areas for attaching modules to a refrigerator door;
FIG. 26 is a cross-sectional view taken along section line XXVI-XXVI in FIG. 25 ;
FIG. 27 is a perspective view of a refrigerator door showing interconnected modules;
FIG. 28 is an enlarged fragmentary perspective view showing the details of the interconnection of the modules to one another; and
FIG. 29 is an exploded perspective view of the modules shown in FIGS. 27 and 28 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring initially to FIG. 1 , there is shown a refrigerator 10 embodying the present invention. The refrigerator shown is illustrative only, it being understood that the refrigerator could be a single door, multiple door, left and right door, or any typical refrigerator design in terms of the refrigerator itself. Refrigerator 10 includes a refrigerated cabinet 12 which includes a freezer compartment with a closure door 14 . The refrigerated cabinet 12 is enclosed by a door 18 which embodies the present invention. Door 18 is coupled to cabinet 12 by upper and lower hinge plates 20 and 30 , respectively. A conduit 22 in door 18 receives a bundle of utilities 24 which extend from cabinet 12 within the door 18 , as explained in greater detail below. The door includes access ports with connectors for coupling one or more modules requiring utilities for their operation and which can be mounted to the liner 26 of the door to provide flexibility for the homeowner in selecting desired modules for their particular convenience. The door 18 includes a typical magnetic seal 28 around the periphery thereof and is pivotally mounted at its upper end by pivot plate 20 and hollow pivot pin 22 serving as a conduit for the utilities 24 . Plate 30 also includes a pivot pin 32 to pivotally mount door 18 at its lower end.
The modules are inserted into liner 26 and are mechanically coupled to the door by conventional coupling members within the side walls 23 of the door. Some modules, such as an ice maker or a water dispenser, require some form of utility, such as electrical operating power, a chilling fluid, a warming fluid, or water for dispensing. Such modules are also described in copending patent application Ser. No. 12/343,682 entitled M ODIFIED A TMOSPHERE FOR F OOD P RESERVATION filed on Dec. 24, 2008, (Publication No. 2009/0229278) and U.S. Pat. No. 8,020,360 entitled D EVICE AND M ETHOD TO P RODUCE A M ODIFIED A TMOSPHERE FOR F OOD P RESERVATION , the disclosures of which are incorporated herein by reference.
Common to each of the following described embodiments of the invention is a conduit which extends into the door and which, in one embodiment, is integrally formed in the door as an open passageway by the process illustrated in FIGS. 2-5 . As seen in FIG. 2 , a door 18 is shown with the inner liner 26 typically of a molded polymeric material and an outer skin 27 coupled thereto. The space 29 between the outer skin and liner 26 is open and a mandrel 31 , such as a tubular member, is inserted in a polyethylene sleeve 33 and positioned within the space 29 at a desired location which may vary from door to door.
In the embodiment shown in FIG. 3 , the sleeve 33 and mandrel 31 are positioned in the corner of the door, and the door is then foamed with an insulative foam 35 , as seen in FIG. 4 . Subsequently, the mandrel 31 is removed, as shown by arrow A in FIG. 4 , leaving a cylindrical passageway defining a conduit 40 extending vertically substantially the height of door 18 . The conduit 40 may be the passageway formed as shown in FIG. 4 or may be lined with a cylindrical tube or sleeve 42 ( FIG. 5 ) for receiving a bundle of utility supplying electrical conductors or fluid tubes for electrical and fluid transmission from either the top of the door, as seen in FIG. 1 , or at the bottom of the door. Utility conduits typically fit within a sleeve 42 which extends through an aperture 45 in end cap 44 positioned over the ends of the door 18 to complete the door construction. It is understood that a lower end cap is likewise employed. Not all doors will include end caps, and, in such event, other pathways for providing the utilities will be employed.
Also, instead of foaming a conduit or passageway utilizing mandrel 31 , a tubular conduit, such as 48 ( FIG. 6 ), can be secured to the inner surface 21 of liner 26 by a suitable bonding adhesive and coupled to utilities again through an aperture 45 in an end cap, such as 44 (not shown in FIG. 6 ). Thus, instead of forming a conduit directly in the foam insulation of the refrigerator door, a physical tubular conduit can be placed either within the door ( FIG. 6 ) or on the liner 26 , as illustrated in FIG. 7 .
In FIG. 7 , a tubular member 48 can also define a conduit 40 for the electrical and fluid utilities supplied to the door 18 . In this embodiment, the utilities are supplied through an aperture 45 in end cap 44 , as in the previous embodiment, but, instead of extending directly into a sleeve 42 as shown in FIG. 5 , they are coupled by right angle connectors through the liner and into an external conduit 48 located in the corner of one of the walls 23 of liner 26 . A cover 25 typically is employed to enclose the utilities carrying conduit 48 . Conduit 48 in the various embodiments extends substantially the length of the height of door 18 to make the electrical conductors and fluid tubes available as needed for modules to be placed in the doors and coupled to the utilities as described in the figures below.
Referring now to FIG. 8 , there is shown a refrigerator door 50 . Door 50 can be manufactured as described in connection with FIGS. 2-7 to include an internal or external conduit which leads to mounting ports 52 at spaced locations within the interior 26 of the refrigerator door. Each port 52 includes a connector 54 which is coupled to the utilities 24 which include, for example, electrical conductors and fluid conductors, for supplying utilities to one or more of a plurality of modules 60 requiring electricity, a cooling fluid, water, a heated fluid, or the like, for providing the module with operating utilities. Each of the modules 60 likewise include a connector 56 which mates with connectors 54 when the module is inserted within the refrigerator door. Although four connectors are shown in FIG. 8 with a pair of modules 60 , one or more of the connectors and modules may be employed. Thus, the system shown in FIG. 8 can accommodate from one to four powered modules. Ports 52 include not only quick disconnect connectors (as described below with reference to FIGS. 11-13 ) coupled to the conduit 40 and utilities contained therein but also mounting brackets 55 mounted on the inside of the door walls 23 and correspondingly interengaging mechanical mounting brackets 57 on the sides of the modules 60 , such that the modules can be plugged into the ports 52 and make simultaneous mechanical connection with door 50 as well as electrical an fluid connection through mating connectors 54 , 56 to the supply conduit 40 .
Another arrangement for supplying a module, such as module 60 , in a door 50 is shown in FIG. 9 in which the conduit 40 extending through the interior of door 50 manufactured in the manner previously described terminates in a trough 58 with a snap-on cover plate 62 , such that the utilities, such as a ribbon electrical connector 64 and quick disconnect fluid connectors 66 can be tucked within the trough 58 when not employed and covered by plate 62 . When a module, such as module 60 which mates with connectors 64 and 66 , respectively, is installed within the port 52 as described in connection with FIG. 8 , the cover plate 62 is removed and the connections made between the mating connectors and the module 60 is mounted to the port through the mechanical brackets 55 and 57 . Openings or troughs 58 provide access to one or more discreet locations within the interior of the refrigerator door.
As seen in FIG. 10 , a pair of vertically spaced connectors, such as connector 64 , are placed in troughs 58 with the cover plate 62 covering the connectors when not in use. When modules, such as module 60 , are installed one or more of the connectors 64 can be extended for coupling to supply operating electrical power or fluids to the module being installed. Not all modules will require utilities and, in such cases, snap-on cover 62 can remain in place when a module does not need operating utilities for its use.
The type of connectors employed for coupling a module to the refrigerator door connectors, such as 54 , 56 and 64 , 66 shown in FIGS. 8-10 , are shown in FIGS. 11-13 . In FIG. 11 , there is shown a dual fluid quick disconnect connector 70 which includes a female connector 72 which has nipples 71 which couple to a pair of fluid conduits 73 and 74 , such as water, coolant fluid for refrigeration, or the like. When disconnected from male connector 76 , ball valves seal the gas or liquid in tubes 73 , 74 from escaping connector 72 which is mounted to the refrigerator door. A male connector 76 is mounted to a module and couples to the female connector 72 when a module is installed. Connector 76 includes fluid sealing O-rings 77 and 78 for the concentric passageways for the two different fluids, which are coupled by connector 70 from the refrigerator door conduits 73 and 74 to the modular conduits 79 and 80 which attach to nipples 81 and 83 of male connector 76 .
FIG. 12 is a perspective view of a single fluid interconnection 85 which includes a pair of fittings 86 and 87 with a quick disconnect coupling therebetween. Fitting 86 includes a nipple 88 coupled to fluid conduit 90 extending from the refrigerator door while fitting 87 includes a nipple 89 coupled to conduit 91 associated with a module. Again, when disconnected, connector 86 is sealed. Not all connectors need to include seals and other types of commercially available connectors, such as available from John Guest International Ltd., can be employed.
FIG. 13 shows a typical electrical quick disconnect coupling 100 which includes a female section 102 with a pair of conductors 103 and 104 which are coupled to a module to be inserted in the refrigerator door. The coupling also includes a male section 106 for the pair of conductors 107 and 108 , which couple to the refrigerator door supply conduit 40 as described in the previous embodiments. The same type of connectors or other similar commercially available connectors can be used for the quick coupling and decoupling of a module to the conduits mating connectors of the refrigerator doors in each of the embodiments.
FIGS. 14 and 15 show yet another embodiment of a refrigerator door 110 embodying the present invention and which includes a liner 26 and first and second conduits 40 and 140 . The first conduit 40 is positioned in the insulated space between liner 26 and skin 27 and positions a connector, such as 53 , at a location on the liner surface of door 110 such that a second conduit 140 with utility wires and tubes contained therein can later be mounted to the door 110 . Conduit 140 will have a connector, such as 54 , which mates with connector 53 and supplies a plurality of spaced connectors 54 along conduit 140 for receiving modules, such as module 112 . Thus, the two conduit system allows a first conduit with a single connector to be manufactured in all refrigerator doors and then, as desired, the customer or retailer can retrofit the door by mounting a snap-in second conduit which mates with the first conduit and provides utilities at various locations to optional modules. The conduit 140 includes a plurality of connectors 54 , such as in the embodiment shown in FIG. 8 , which may include both types of connectors 70 , 85 , and 100 as described in the previous drawing figures to supply modules, such as module 112 , at selected vertically spaced locations operating utilities for the module 112 . The utility wires and tubes can extend through an aperture 45 in the upper edge of the door at the pivot point and into conduit 40 in a conventional manner.
FIG. 15 is a vertical cross-sectional view of the positioning of the conduits 40 and 140 and utility conduits 90 , 107 , and 108 , for example, as in the previous embodiment, within conduits 40 and 140 . A decorative shroud 114 ( FIG. 15 ) with openings at spaced-apart locations, as seen in FIG. 14 , to expose connectors 54 may be employed to cover conduit 140 . As in the previous embodiments, the sides 23 of the refrigerator door include conventional mounting brackets 55 for receiving modules, such as module 112 .
In the embodiment shown in FIGS. 16 and 17 , a conduit 40 is formed in a recess 117 in the back wall of liner 26 of door 120 to conceal the conduit and provide additional space for the modules 112 inserted therein. These modules, like the remaining modules, include mechanical coupling brackets 57 which engage brackets 55 in the refrigerator door for securing the modules mechanically to the refrigerator. The modules 112 also include connectors 56 which mate with connectors 54 in the refrigerator door for supplying utilities from the conduit 40 to the modules.
In addition to the door construction shown in FIGS. 14-17 , a conduit 40 can be embedded as shown in the horizontal cross section of FIG. 18 , which represents the molding of the conduit 40 in the center insulated area of the liner in a process similar to that shown in FIGS. 2-5 , except the positioning of the conduit is centered in the liner 26 to mate with a module, such as module 112 , positioned therein and coupled to the door utilizing coupling brackets 55 and 57 in the door and module, respectively.
FIGS. 19 and 20 show an alternative embodiment of the invention in which a refrigerator door 125 , including a liner 26 , has the conduit 40 formed in a rectangular channel on the surface of the liner facing the cabinet of the refrigerator. The conduit includes a plurality of spaced-apart connectors 150 at various locations which are selectively covered by an accordion or foldable cover 152 and 154 , as best seen in FIG. 20 . The movable covers 152 , 154 selectively expose connectors 150 such that a module, such as modules 60 , 112 , and 118 ) can be inserted therein and receive the utilities necessary for operation of the modules. Door 125 includes the usual coupling mechanism, as does the module, for coupling the module mechanically to the door as well as electrically and fluidly to the connectors 150 .
Another embodiment of the invention is shown in FIGS. 21 and 22 in which a conduit 40 is again mounted to the liner 26 of door 130 and includes utilities which are coiled in a slacked condition represented by dashed lines 160 in the figures. The utilities extend from aperture 45 in door 130 through the insulation into the channel-like conduit 40 . Conduit 40 includes, in this particular embodiment, a guide slot 161 ( FIG. 22 ) and guide tab 162 on a carrier 164 which includes connectors 166 and 168 for receiving the utilities through coiled or slack conductors and tubes 160 . Thus, the adjustable positioning of carrier 164 allows a module to be positioned substantially anywhere along the vertical height of door 130 by moving carrier 164 to a desired location, which can be selected by the owner of the refrigerator.
In the embodiment shown in FIGS. 23 and 24 , the door 135 allows similar flexibility, however, it employs an electrical only movable connector 170 which comprises a push-spring contact in a track 172 having electrical conductors 173 and 174 on opposite sides, similar to a track for used for track lighting. By compressing the opposite sides of connector 170 , the socket can be moved upwardly and downwardly to the desired adjusted position. In the embodiment shown, two such connectors 170 are shown, although additional connectors can be mounted within the track 172 , if desired, to accommodate more than two modules at infinitely adjustable positions.
Another embodiment of the invention is shown in FIGS. 25 and 26 in which a refrigerator door 138 includes horizontally extending conduits 40 , 40 ′, 40 ″, and 40 ″′ which are vertically spaced and molded into the liner 26 , as shown in FIG. 26 , to include utility tubes and conductors, such as 73 , 74 , 90 , and 107 , 108 , respectively, as shown in connection with the connector diagrams of FIGS. 11-13 . At horizontally spaced locations along conduits 40 - 40 ″′, there are provided connectors, such as 175 , which, like the remaining connectors in the other embodiments, contain quick disconnect couplings, such as shown in FIGS. 11-13 , for plugging a module, such as module 60 , 112 , and 118 , into the conduits for receiving utilities extending through aperture 45 in the top of door 138 . By providing horizontally spaced connectors 175 , the module connector can be located at the left, center, or right edge of the module as desired, which provides more flexibility for positioning a module within the door 138 .
In addition to providing conduits within the refrigerator door itself, it is possible to utilize modules as the structure for extending utilities throughout the inside of a refrigerator door, as seen in FIGS. 27-29 . In these figures, there is shown a refrigerator door 145 which receives utilities through an aperture 45 in the upper or lower corner of the door in a conventional manner. The utilities, however, extend through an elbow 180 ( FIG. 28 ) from the liner 26 into a first module 182 by means of a quick disconnect coupling 184 . Module 182 is coupled to the liner by standard coupling brackets 185 , which communicate with brackets 55 in the inner edges 23 of the door, as seen in FIG. 29 .
Module 182 may utilize the utilities such as fluid or electricity provided through elbow 180 and connector 182 or merely pass the utilities through to a second module 186 spaced below module 182 and coupled thereto by means of a second quick disconnect coupling 188 . Module 186 also can be coupled to a lower module 190 through a quick disconnect coupling 188 to receive operating power and fluids therefrom. Modules 182 , 186 , and 190 may be powered by utilities through the conduits or, in the case of modules 182 and 186 , it may not require the utilities but act as a passageway for the module 190 . In this instance, it is not necessary to mold the conduit within the refrigerator door but only provide a coupling at elbow 180 such that the modules can be coupled thereto and positioned within the refrigerator door.
Thus, with the present invention, a great deal of flexibility of the options available to the consumer and offered by a retailer is possible. As new modules become available, the fluids, such as coolant liquids, cooled air, inert gases, heated air, electrical power and binary data, can be supplied utilizing the system of this invention. It will become apparent to those skilled in the art that various modifications to the preferred embodiments of the invention as described herein can be made without departing from the spirit or scope of the invention as defined by the appended claims. | A refrigerator door includes the ability to mount a variety of modules requiring utilities, such as electricity and fluids, within adjustable locations in the door of the refrigerator. The door includes a conduit extending in at least one direction and including one or more plug-in connectors for allowing a module with a mating connector to be positioned on the door for supplying operating utilities to the module. This allows the purchaser of the refrigerator to add components and accessories to the refrigerator after purchase or select desired features at the time of purchase. | 5 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a National Stage of International Application No. PCT/JP2009/055202 filed Mar. 17, 2009, the contents of all of which are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
The present invention relates to a pulsation damper, particularly to a pulsation damper that is integrally provided to a high-pressure fuel pump for feeding high pressure fuel to the delivery pipe of an in-cylinder injection internal combustion engine that uses gasoline as fuel, and reduces pulsations generated by the operation of the pump.
BACKGROUND ART
As is known, an in-cylinder injection internal combustion engine using gasoline as fuel includes a high-pressure fuel pump that receives fuel pumped up from a fuel tank by a fuel pump, pressurizes the fuel to a pressure higher than the discharge pressure of the fuel pump, and sends the pressurized fuel to a delivery pipe (high-pressure piping) connected to an injector serving as a fuel injection device. Typically, in an internal combustion engine having such a high-pressure fuel pump, the pressure of fuel that has been pumped up from the fuel tank by the fuel pump is maintained at a “feed pressure”, which is not more than 400 kPa when the fuel is supplied to a fuel chamber formed in the high fuel pressure fuel pump. Fuel that has been supplied to the fuel chamber is then sent from the fuel chamber to a pressurizing chamber in a cylinder via an electromagnetic valve. When the amount of fuel in the pressurizing chamber is adjusted to a predetermined amount by an upward motion of a plunger vertically reciprocating in the cylinder, the electromagnetic valve is closed. When the electromagnetic valve is closed, the fuel is pressurized as the plunger is moved upward, and sent under pressure to the delivery pipe via a check valve. The pressure of fuel sent under pressure from the pressurizing chamber is variable between 4 to 13 MPa in accordance, for example, closing timing of the electromagnetic valve. Then, the fuel of which the pressure has been accumulated in the delivery pipe, is directly injected into the cylinders of the engine by valve opening of the injector. At this time, the amount of fuel that flows into the fuel chamber of the high-pressure fuel pump from the fuel pump per unit time is not necessarily equal to the amount of fuel that flows out from the fuel chamber to the pressurizing chamber in the cylinder per unit time. The difference in the fuel amount causes pulsations in the fuel pressure in the fuel chamber. Also, in such a high-pressure fuel pump, fuel that is being pressurized after being sent from the fuel chamber to the pressurizing chamber of the cylinder is returned to the fuel chamber, so that the amount of fuel sent from the pump to the delivery pipe is adjusted. Therefore, the pressure difference between the fuel in a section including the fuel chamber and the fuel that is being pressurized also generates pulsations of the fuel pressure in the fuel chamber. Such pressure pulsation of fuel, in other words, variation in pressure, varies the amount of fuel sent from the fuel chamber to the pressurizing chamber in the cylinder. This contributes to degradation of the adjustment accuracy of the amount of fuel sent from the high-pressure fuel pump to the delivery pipe.
Accordingly, high-pressure fuel pumps disclosed in Patent Documents 1 and 2 each have a pulsation damper that absorbs pressure pulsation of fuel in a fuel chamber, so as to reduce pressure pulsation described above.
The pulsation damper disclosed in Patent Document 1 has a cross-sectional structure shown in FIG. 9 . That is, the pulsation damper has two sets of two diaphragms 71 a , 71 b provided in a fuel chamber 75 defined in a housing 70 . The diaphragms 71 a , 71 b have outer peripheral joint sections 73 a , 73 b , which are welded to each other and supported by a support member 74 . Each set of the diaphragms 71 a , 71 b has a gas chamber 72 a , 72 b between two diagrams. The gas chambers 72 a , 72 b are filled with inert gas of a predetermined pressure, for example, argon gas or nitrogen gas. The volume of the gas chambers 72 a , 72 b changes in accordance with the fuel pressure in the fuel chamber 75 , so that pressure pulsation as described above is absorbed. The fuel chamber 75 receives fuel from a fuel tank (not shown) via a fuel passage 76 connected to the fuel chamber 75 .
The pulsation damper disclosed in Patent Document 2 has a cross-sectional structure shown in FIG. 10 and includes a plate member 83 and a diaphragm 81 . The plate member 83 forms a fuel chamber 85 with a housing 84 . The plate member 83 and the diaphragm 81 are welded to each other at a joint section 81 a at the periphery. An annular member 86 is provided along the joint section 81 a . The plate member 83 is covered with a pump cover 80 . A gas chamber 82 defined by the plate member 83 and the diaphragm 81 is filled with inert gas of a predetermined pressure, like the pulsation damper disclosed in Patent Document 1. In accordance with the fuel pressure in the fuel chamber 85 , the diaphragm 81 is displaced into the fuel chamber 85 or toward the plate member 83 , thereby absorbing pressure pulsation of fuel.
With either of the pulsation damper of Patent Document 1 or 2, when pressure pulsation of fuel occurs in the fuel chamber, the diaphragm is deformed in accordance with the pressure pulsation in a direction to increase or reduce the volume of the gas chamber. This absorbs the pressure pulsation, thereby reducing changes in the fuel pressure.
In either of these pulsation dampers, when the volume of the gas chamber changes due to deformation of the diaphragm, a force resulting from the pressure of gas filling the gas chamber acts on members forming the outer periphery of the gas chamber including the joint sections, that is, acts on the diaphragms and the plate member. The force acts from within the gas chamber toward the outside of the gas chamber. Thus, when the force acts on the joint sections, it acts to separate joined members, specifically, the joined diaphragms or the joined diaphragm and plate member. Such a force acts on the joint section each time the diaphragms are deformed due to pressure pulsation. Although the force does not completely separate the joined members from each other, the force causes delamination from the innermost parts of the joint sections. In other words, joint loosening occurs. Therefore, these pulsation dampers need to have members for preventing joint loosening such as the support member 74 (Patent Document 1) or the annular member 86 (Patent Document 2), which apply force for pressing joined members against each other.
Patent Document 1: Japanese Laid-Open Patent Publication No. 2008-19728
Patent Document 2: Japanese Laid-Open Patent Publication No. 2008-2361
SUMMARY OF THE INVENTION
Accordingly, it is an objective of the present invention to provide a pulsation damper that, despite a simple structure, is capable of maintaining high reliability at a joint section of a diaphragm that is integrated with a high-pressure fuel pump and operates together with a gas chamber to inhibit pressure pulsations of fuel.
To achieve the foregoing objective and in accordance with the present invention, a pulsation damper for a fuel chamber of a high-pressure fuel pump is provided. The pulsation damper includes a diaphragm and a support member. The diaphragm has a displacement section that is displaced by pressure acting there against. The diaphragm reduces pressure pulsation in the fuel chamber by means of displacement of the displacement section. The support member supports the diaphragm, and, together with the diaphragm, forms a gas chamber. The diaphragm is shaped like a lidded cylinder and has a bottom formed by the displacement section and a cylindrical circumferential section extending perpendicularly from the displacement section. The cylindrical circumferential section has a fitting section that is joined to the support member while being fitted to the support member.
In the above configuration, the cylindrical circumferential section extends from the displacement section of the diagram at a right angle. While being fitted to the support member for the diaphragm, the fitting portion of the cylindrical circumferential section is joined to the support member. Accordingly, the joint section and the displacement section are perpendicular to each other. That is, if the pressure caused by changes in volume of the gas chamber due to displacement of the displacement section acts on the joint section between the cylindrical circumferential section and the support member, the pressure does not act in a direction for separating the fitting portion from the support section. Therefore, the reliability at the joint section between the diaphragm and the support member is maintained at a high level.
According to one aspect of the present invention, the displacement section includes an annular projection and a flat section surrounded by the projection. The annular projection is continuous to the cylindrical circumferential section and has an arcuately bulging cross-sectional shape in the direction opposite to the support member. The cylindrical circumferential section is perpendicular to the flat section.
The stress generated in the diaphragm by pressure applied to the displacement section thereof concentrates on a part that is continuous to the cylindrical circumferential section, which extends in a direction perpendicular to the displacement section, that is, on the periphery of the displacement section. In this regard, the projection that has an arcuately bulging cross-sectional shape in the direction opposite to the support member is formed on the periphery of the displacement section, on which stress is concentrated. Also, the remainder of the displacement section is formed to be flat to increase the area for receiving stress concentrated on the periphery. This relaxes the stress acting on the diaphragm. This allows the reliability at the joint section to be maintained at a high level, and therefore further improves the pressure tolerance as a pulsation damper.
According to one aspect of the present invention, the support member is a pump cover for the high-pressure fuel pump.
According to this configuration, the pump cover of the high-pressure fuel pump, to which the pulsation damper is attached, is used as the support member for the diaphragm of the pulsation damper. Thus, compared to a configuration with an additional support member for supporting the diaphragm, the number of components of the high-pressure fuel pump is reduced, and the size of the high-pressure fuel pump is minimized.
In accordance with one aspect of the present invention, the pump cover partially has a low rigidity section with low rigidity.
According to this configuration, the low rigidity section of the pump cover correspondingly increases the amount of displacement of the pump cover in response to the pressure applied to the displacement section of the diaphragm. That is, in addition to the diaphragm having the displacement section, the cover serving as the support member can absorb pressure changes in fuel, in other words, pressure pulsation. This increases the range of pressure pulsation that can be absorbed by the entire pulsation damper, and therefore improves pulsation reducing performance.
The low rigidity section is, for example, formed by attaching the pump cover to the upper end cylindrical section of a housing of the high-pressure fuel pump, and reducing the thickness of the part that is attached to the upper end cylindrical section so that it has a lowered rigidity. Alternatively, the thickness is reduced in a part of the pump cover to which the cylindrical circumferential section of the diaphragm is joined to form the low rigidity section. Further, the thickness is reduced in a part of the pump cover that faces the displacement section of the diaphragm to form the low rigidity section. These possible structures are all effective.
According to these configurations, it is possible to expand the range of pressure that can be absorbed by the pulsation damper simply by reducing the thickness in a part of the material of the pump cover to form a low rigidity section.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view with a block diagram, showing a high-pressure fuel pump and surrounding configuration, in which a pulsation damper according to one embodiment of the present invention is used;
FIG. 2 is a cross-sectional view showing the cross-sectional structure of the pulsation damper according to the same embodiment;
FIG. 3 is a cross-sectional view showing the cross-sectional structure of a pulsation damper according to a modification of the same embodiment;
FIG. 4 is a graph showing a relationship between a pressure difference calculated by subtracting the pressure of gas sealed in a gas chamber from a fuel pressure, and corresponding changes in volume of the gas chamber;
FIG. 5 is a graph showing a relationship between the pressure difference and the stress per unit amount of change in volume;
FIG. 6 is a cross-sectional view showing the cross-sectional structure of a pulsation damper according to another embodiment;
FIG. 7 is a cross-sectional view showing the cross-sectional structure of a pulsation damper according to another embodiment;
FIG. 8 is a cross-sectional view showing the cross-sectional structure of a pulsation damper according to another embodiment;
FIG. 9 is a cross-sectional view showing the cross-sectional structure of a pulsation damper according to prior art; and
FIG. 10 is a cross-sectional view showing the cross-sectional structure of a pulsation damper according to another prior art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A pulsation damper according to one embodiment of the present invention will now be described with reference to FIGS. 1 and 2 .
FIG. 1 schematically shows a high-pressure fuel pump 20 having a pulsation damper according to the present embodiment and a surrounding structure, or a fuel supply system. The high-pressure fuel pump 20 is attached, for example, to a cylinder head cover of an in-cylinder injection internal combustion engine that uses gasoline as fuel.
As shown in FIG. 1 , the high-pressure fuel pump 20 has a housing 21 , in which a fuel inlet 22 a and a fuel chamber 23 are provided. Fuel that has been pumped by a fuel pump (feed pump) 41 flows into the fuel inlet 22 a . The fuel is then temporarily retained in the fuel chamber 23 . Also, fuel retained in the fuel chamber 23 is sent to a pressurizing chamber 22 c in a cylinder via a fuel communication passage 22 b and an electromagnetic valve 24 . The fuel is then pressurized by a plunger 25 in the pressurizing chamber 22 c , and the pressurized fuel is sent under pressure to a delivery pipe 50 via a check valve 26 and a fuel outlet 22 d.
In this high-pressure fuel pump 20 , the fuel chamber 23 has an opening upper end, and the opening is covered with a pulsation damper. The pulsation damper includes a pump cover 10 and a diaphragm 11 joined to the pump cover 10 . The diaphragm 11 has a flat section 11 a , a projection 11 b , and a joint section 11 c . The projection 11 b is formed to surround the flat section 11 a and has an arcuate cross-sectional shape bulging toward the fuel chamber 23 . The joint section 11 c is joined to the pump cover 10 . The electromagnetic valve 24 is located in the fuel communication passage 22 b , which connects the fuel chamber 23 and the pressurizing chamber 22 c to each other. The electromagnetic valve 24 is a normally closed open type. That is, the electromagnetic valve 24 is closed only when the coil is energized, and closes the fuel communication passage 22 b . Energization of the electromagnetic valve 24 is controlled by an electronic control unit 60 , which controls the operational state of the in-cylinder injection internal combustion engine. Further, a plunger 25 is provided in the cylinder. An end of the plunger 25 opposite to the pressurizing chamber 22 c is coupled to a lifter 27 , while the plunger 25 is urged toward the bottom dead center by a spring 28 . The bottom of the lifter 27 is pressed against a pump cam 30 , which is provided on and rotates integrally with a camshaft. Each time the cam nose of the pump cam 30 lifts the lifter 27 , the plunger 25 is moved upward to pressurize fuel in the pressurizing chamber 22 c.
In the fuel supply system including the high-pressure fuel pump 20 as described above, fuel stored in the fuel tank 40 is supplied to the fuel inlet 22 a of the high-pressure fuel pump 20 at a discharge pressure, for example, of 400 kPa by the fuel pump (feed pump) 41 . The fuel that has been supplied to the high-pressure fuel pump 20 is temporarily retained in the fuel chamber 23 , and is then delivered to the pressurizing chamber 22 c via the fuel communication passage 22 b on condition that the plunger 25 is moving downward in the cylinder and that the electromagnetic valve 24 is in the open state (non-energized state). Thereafter, as the plunger 25 is moved upward, the fuel that has been sent to the pressurizing chamber 22 c starts being pressurized. While the electromagnetic valve 24 is open, the fuel is not provided to the fuel outlet 22 d , but is returned to the fuel chamber 23 via the fuel communication passage 22 b . Then, when the electromagnetic valve 24 is closed based on energization by the electronic control unit 60 , the pressure of fuel in the pressurizing chamber 22 c is increased, for example, to 4 to 13 MPa. The pressurized fuel is provided under pressure from the fuel outlet 22 d to the delivery pipe 50 via the check valve 26 . In the high-pressure fuel pump 20 as described above, it is possible to control the amount and pressure of fuel delivered under pressure to the delivery pipe 50 by controlling the valve closing timing of the electromagnetic valve 24 when the plunger 25 is moved upward. In this manner, fuel stored under pressure in the delivery pipe 50 is injected into the cylinders of the engine when the injector 51 is opened.
In the above described fuel supply system, the amount of fuel supplied per unit time to the high-pressure fuel pump 20 , particularly to the fuel chamber 23 by the fuel pump 41 is not necessary equal to the amount of fuel supplied to the pressurizing chamber 22 c from the fuel chamber 23 via the electromagnetic valve 24 . Therefore, due to the difference between the amount of fuel supplied to and the amount of fuel discharged from the fuel chamber 23 , variation of fuel pressure, or pressure pulsation occurs. In addition, the fuel that is being pressurized as the plunger 25 is moved upward in the pressurizing chamber flows back to the fuel chamber 23 before the electromagnetic valve 24 is closed. This is also a cause of pressure pulsation. Such pressure pulsation is absorbed by the pulsation damper provided to cover the opening of the fuel chamber 23 .
Next, the configuration of the pulsation damper, which absorbs pressure pulsation of fuel in the high-pressure fuel pump 20 and the mechanism of absorption of pressure pulsation will be described with reference to FIG. 2 .
FIG. 2 shows the cross-sectional structure of the pulsation damper according to the present embodiment. As shown in FIG. 2 , the pulsation damper includes the pump cover 10 , which covers the opening of the high-pressure fuel pump 20 ( FIG. 1 ), and the diaphragm 11 , which is supported by the pump cover 10 . The diaphragm 11 contacts fuel retained in the fuel chamber 23 ( FIG. 1 ) and is therefore acted upon by the pressure of the retained fuel. In the present embodiment, the diaphragm 11 is formed like a lidded cylinder with the flat section 11 a and the annular projection 11 b surrounding the flat section 11 a . The flat section 11 a occupies most of the surface area of the diaphragm 11 . The pressure of the fuel applied to the flat section 11 a in a concentrated manner. The projection 11 b bulges into the fuel chamber 23 and has an arcuate cross-sectional shape. That is, a cylindrical circumferential section is provided on the outer periphery of the projection 11 b . The cylindrical circumferential section is perpendicular to the flat section 11 a forming the bottom and extends in a direction opposite to the bulging direction of the projection 11 b . The diaphragm 11 is formed of stainless steel material such as SUS631 (precipitate hardened steel), for example, through pressing to have the described shape. The pump cover 10 also includes a flat section 10 a and an annular projection 10 b surrounding the flat section 10 a . When the pulsation damper is assembled, the flat section 10 a of the pump cover 10 is parallel to the flat section 11 a of the diaphragm 11 , and the projection 10 b bulges toward the diaphragm 11 . Also, a circumferential section is provided on the outer periphery of the projection 10 b . The circumferential section extends in a direction opposite to the bulging direction of the projection 10 b . A hook section 10 c is provided at the upper end of the circumferential section. The hook section 10 c is hooked to the upper end of the opening of the housing 21 ( FIG. 1 ). The pump cover 10 is formed of stainless steel material such as SUS430 (ferritic stainless steel), for example, through pressing to have the described shape.
When assembling the pump cover 10 and the diaphragm 11 together, the distal end of the circumferential section of the diaphragm 11 that is perpendicular to the flat section 11 a and extends in the direction opposite to the bulging direction of the projection 11 b is press-fitted about the circumferential section of the pump cover 10 that is perpendicular to the flat section 10 a and extends in the direction opposite to the bulging direction of the projection 10 b . The press-fitted section is fixed to the circumferential section of the pump cover 10 , which serves as a support member, by welding. In FIGS. 1 and 2 , a part of the diaphragm 11 that is fixed by welding is referred to as the joint section (fitting section) 11 c . When these members are fitted to each other, the gas chamber 12 , which is defined by the pump cover 10 and the diaphragm 11 , is filled with inert gas such as argon gas or nitrogen gas, at predetermined pressure, such as 400 kPa. The gas is sealed in the gas chamber 12 . When the pump cover 10 and the diaphragm 11 are welded to each other, laser welding can be employed in which laser energy of carbon dioxide gas laser or YAG laser is used. Alternatively, resistance welding can be employed in which two members to be welded are pressed against each other and provided with electric current, so that resistance heat melts the members to be welded.
In the pulsation damper, which is configured as described above to be integrally assembled with the high-pressure fuel pump 20 ( FIG. 1 ), the flat section 11 a of the diaphragm 11 , which is exposed to the fuel in the fuel chamber 23 ( FIG. 1 ), receives pressure pulsation of fuel, which is generated when the above described high-pressure fuel pump 20 ( FIG. 1 ) operates. Since the applied fuel pressure, particularly the pressure of fuel that is being pressurized in the pressurizing chamber 22 c ( FIG. 1 ) is normally higher than the pressure of the inert gas sealed in the gas chamber 12 , the flat section 11 a of the diaphragm 11 is deformed toward the pump cover 10 . That is, the deformation reduces the volume of the gas chamber 12 . This absorbs the pressure of fuel. Further, in the pulsation damper according to the present embodiment, when welding the diaphragm 11 to the pump cover 10 , a part of the joint section 11 c where these members are overlapped is perpendicular to the flat section 11 a , which receives the pressure of fuel. Thus, when pressure pulsation of fuel occurs, the joint section 11 c only receives shearing load. Also, due to the decrease in the volume of the gas chamber 12 , the pressure of the sealed gas acting on the joint section 11 c acts in a direction substantially parallel to the joint section 11 c . Since such pressure never acts to separate overlapped parts of the pump cover 10 and the diaphragm 11 in the joint section 11 c , the above described joint loosening is not likely to occur.
The present inventors found out that when the same pressure was applied to both the prior art pulsation damper configured as shown in FIG. 9 and the pulsation damper of the present embodiment, joint loosening, or delamination of the overlapped parts reached 300 μm at maximum in the prior art pulsation damper, and joint loosening was significantly smaller at 0.05 μm in the pulsation damper of the present embodiment.
In the case of the prior art pulsation damper shown in FIG. 10 , when fuel pressure is applied to the flat section of the diaphragm 81 , the stress generated due to deformation of the diaphragm 81 concentrates on the bent section. In contrast, in the pulsation damper according to the present embodiment, the projection 11 b is provided about the flat section 11 a of the diaphragm 11 . The stress generated due to deformation of the diaphragm 11 is relaxed by the projection 11 b . That is, compared to the prior art pulsation damper, the area in which stress is concentrated can be enlarged, so that the maximum value of the stress is lowered. Therefore, when designing pulsation dampers assuming that the maximum value of stress that acts on the section is the same, the separation damper of the present embodiment can have a diaphragm of a larger diameter or a less thickness than that in the prior art pulsation damper. The amount of displacement of a diaphragm is proportional to the 4th power of its radius and inversely proportional to the 3rd power of the thickness. Accordingly, the pulsation damper of the present embodiment can have a larger displacement amount than the prior art pulsation damper. In other words, without increasing the number of the diaphragm 11 , the displacement amount of the volume can be increased.
The pulsation damper of the present embodiment may be modified as shown in FIG. 3 . In this modification, a number of, for example, three, projections 11 b are provided about the flat section 11 a . However, the inventors have found out that the smaller the number of the projections 11 b , the more remarkable the stress relaxing effect became. That is, as shown in FIG. 2 , the structure in which only one projection 11 b is provided in the periphery of the diaphragm 11 achieves the most remarkable stress relaxing effect. Hereafter, the results of experiments performed by the inventors will be described with reference to FIGS. 4 and 5 . The experiments were related to the relationship between the number of projections 11 b provided about the flat section 11 a of the diaphragm 11 and the stress relaxing effect.
FIG. 4 is a graph showing the relationship between a pressure difference, or the pressure obtained by subtracting the pressure of the inert gas sealed in the gas chamber 12 from the fuel pressure, and the amount of change in volume of the gas chamber 12 , that is, the amount of displacement of the flat section 11 a of the diaphragm 11 . The black dots in the graph represent sampled values obtained from the structure shown in FIG. 2 , and the black squares represent sampled values obtained from the structure shown in FIG. 3 .
As obvious from FIG. 4 , the amount of change in volume per unit pressure acting on the diaphragm 11 has a greater value when only one projection 11 b is provided in the periphery of the diaphragm 11 either in a case where the pressure difference has a positive value, that is, when the fuel pressure is greater than the pressure of the inert gas sealed in the gas chamber 12 , and the diaphragm 11 is deformed toward the pump chamber 23 , or in a case where the pressure difference has a negative value, that is, when the diaphragm 11 is deformed toward the fuel chamber 23 .
On the other hand, FIG. 5 is a graph showing the relationship between the pressure difference and the value obtained by dividing, by the amount of change in volume, the maximum value of stress generated when the diaphragm 11 is deformed. In this graph, as in FIG. 4 , the black dots represent values obtained from the structure shown in FIG. 2 , and the black squares represent values obtained from the structure shown in FIG. 3 .
As obvious from FIG. 5 , in a case where the pressure difference has a positive value, the stress per unit amount of change in volume is substantially the same between the structure shown in FIG. 2 and the structure shown in FIG. 3 , when the pressure difference is 300 kPa. In contrast, in a case where the pressure difference is 400 kPa, the structure shown in FIG. 3 has smaller stress per unit amount of change in volume than the structure shown in FIG. 2 . However, the difference is substantially equal to zero. When the pressure difference has a positive value, and between 100 and 200 kPa, the structure shown in FIG. 2 has a smaller stress per unit amount of change in volume. On the other hand, in a case where the pressure difference has a negative value, the smaller the absolute value of the pressure difference, the greater the difference by which the stress per amount of change in volume of the structure shown in FIG. 2 is smaller than that of FIG. 3 becomes. Further, in the range of the pressure difference between −100 to −400 kPa, the stress per unit amount of change in volume of the structure shown in FIG. 2 is 1.5 times smaller than the structure shown in FIG. 3 .
With reference to the results shown in FIGS. 4 and 5 , regardless whether the pressure difference has a positive or negative value or the magnitude of the pressure difference, the structure shown in FIG. 2 achieves a greater amount of change in volume than the structure shown in FIG. 3 . Also, the structure shown in FIG. 2 generally has smaller stress per unit amount of change in volume than that of FIG. 3 . Even if the stress per unit amount of change is greater in FIG. 2 , the different is substantially zero. That is, by providing only one projection 11 b about the diaphragm 11 , the stress relaxing effect and the effect of amount of change in volume are remarkable compared to a case where a multiple, for example, three projections 11 b are formed.
As described above, the pulsation damper according to the present embodiment has the following advantages.
(1) The cylindrical circumferential section, which perpendicularly extends from the flat section 11 a of the diaphragm 11 via the projection 11 b , is fitted about the pump cover 10 . In this state, the fitting section of the cylindrical circumferential section is welded to the pump cover 10 . That is, the diaphragm 11 and the pump cover 10 are assembled such that the joint section 11 c and the flat section 11 a are perpendicular to each other. Thus, even if the pressure caused by changes in volume of the gas chamber 12 due to displacement of the flat section 11 a acts on the welded section between the cylindrical circumferential section and the pump cover 10 , the pressure does not act in a direction for separating the joint section 11 c from the pump cover 10 . Therefore, the reliability of the joint between the pump cover 10 and the joint section 11 c is maintained at a high level.
(2) The projection 11 b , which has an arcuate cross-sectional shape bulging in a direction opposite to the pump cover 10 , is formed in a part surrounding the flat section 11 a , on which stress is concentrated when the diaphragm 11 is displaced, that is, in a periphery continuous to the cylindrical circumferential section of the diaphragm 11 . This relaxes the stress concentrated on the periphery, and thus maintains the reliability of the joint section 11 c at a high level. That is, this further improves the pressure tolerance of the entire pulsation damper.
(3) As in the modification of the present embodiment shown in FIG. 3 , a plurality of projections 11 b may be provided in the periphery of the diaphragm 11 . When only one projection 11 b is provided in the periphery of the diaphragm 11 , a remarkable stress relaxing effect is achieved, and the reliability at the joint section 11 c can be maintained at a high level.
(4) As a support member for the diaphragm 11 , the pump cover 10 of the high-pressure fuel pump 20 is employed. The number of components of the high-pressure fuel pump 20 can be reduced, and the size of the high-pressure fuel pump 20 is maintained to be minimized.
The above described embodiment and its modification may be modified as shown below.
As shown in FIG. 2 or FIG. 3 , which show a modification, the pump cover 10 forming the pulsation damper substantially has a constant thickness. However, the rigidity of the pump cover 10 may be reduced by any of the following configurations.
a. As shown in FIG. 6 , which corresponds to FIG. 2 , the hook section 10 c may have a thin section 10 d , which is thinner than the remainder of the pump cover 10 .
b. As shown in FIG. 7 , which corresponds to FIG. 2 , a thin section 10 e may be provided in a circumferential section that is perpendicular to the flat section 10 a and projects in a direction opposite to the bulging direction of the projection 10 b , that is, in a part to which the diaphragm 11 is welded.
c. As shown in FIG. 8 , which corresponds to FIG. 2 , a thin section 10 f may be formed in the flat section 10 a of the pump cover 10 .
These configurations provide the following advantage in addition to the above advantages (1) to (4).
(5) The amount of displacement of the pulsation damper in accordance with pressure applied to the flat section 11 a of the diaphragm 11 can be increased by the amount of flexing of low rigidity sections, or the thin sections 10 d , 10 e , 10 f. That is, in addition to displacement of the diaphragm 11 , the pump cover 10 serving as a support member can absorb pressure pulsation generated in fuel, so that the pressure pulsation reduction effect is maintained at a high level.
Instead of reducing the rigidity of the pump cover 10 by providing the thin sections 10 d , 10 e , 10 f , the parts that correspond to the thin sections may be formed of a material different from the material of the remaining parts, or of a material having a lower rigidity than the remaining parts, so that the rigidity of the pump cover 10 is reduced. However, different types of stainless steel materials, which are preferable as the materials for the pump cover 10 , do not vary significantly in rigidity. Also, forming the pump cover 10 of different materials requires complicated processes. Thus, reduction of the rigidity of the pump cover 10 is practically most easily and effectively achieved by providing the thin section 10 d , 10 e , or 10 f.
In the illustrated embodiment, the diaphragm 11 is fitted about the pump cover 10 . However, the diaphragm 11 may be fitted inside the pump cover 10 .
When assembling the pump cover 10 and the diaphragm 11 together, the distal end of the periphery of the diaphragm 11 is press-fitted about the periphery of the pump cover 10 , and then the press-fitted section is welded to fix the diaphragm 11 to the pump cover 10 . However, the diaphragm 11 may be joined to the pump cover 10 by a method other than welding. For example, the diaphragm 11 may be joined to the pump cover 10 by fixing the press-fitted section by adhesive or brazing.
The pump cover 10 of the high-pressure fuel pump 20 also functions as a support member supporting the diaphragm 11 . However, the diaphragm 11 may be supported by an additional member provided separately from the pump cover 10 .
In the pulsation damper according to the modification shown in FIG. 3 , the diaphragm 11 has three projections 11 b of the same widths. However, the widths of the projections may be different. Nevertheless, the pulsation damper shown in FIG. 2 is most favorable for relaxing the stress as described above.
The diaphragm 11 has at least one projection 11 b in the periphery surrounding the flat section 11 a . However, a diaphragm having no projection 11 b may be used. That is, a diaphragm may be used in which a flat section 11 a includes a displacement section having an appropriate curvature and continuous to the cylindrical circumferential section. | A pulsation damper mounted in a fuel chamber ( 23 ) of a high-pressure fuel pump ( 20 ) is provided with a diaphragm ( 11 ) having a flat section ( 11 a ) displaced when fuel pressure is applied thereto, a pump cover ( 10 ) for supporting the diaphragm ( 11 ), and a gas chamber ( 12 ) formed by the diaphragm ( 11 ) and the pump cover ( 10 ). Pressure pulsation occurring in the fuel chamber ( 23 ) is suppressed by displacement of the flat section ( 11 a ). The diaphragm ( 11 ) is formed in a closed-bottomed tubular shape with the flat section ( 11 a ) located at the bottom and has a projection ( 11 b ) provided to the periphery of the flat section ( 11 a ) and projecting to the side opposite to the pump cover ( 10 ). A tubular peripheral section extending from the outer periphery of the projection ( 11 b ) so as to be vertical to the flat section ( 11 a ) is fitted over the pump cover ( 10 ). The externally fitting portion of the tubular peripheral section is a joint section ( 11 c ) joined to the pump cover ( 10 ). | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of non-provisional application Ser. No. 12/472,656 filed on May 27, 2009, which in turn claimed the benefit of U.S. provisional patent application 61/060,838 filed Jun. 12, 2008.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
REFERENCE TO A SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX
Not Applicable.
BACKGROUND OF THE INVENTION
Thieves use a variety of tools to break into fenced areas secured with a chain or cable and a padlock or to steal from retail stores displaying wheelbarrows, lawnmowers, barbecue grills, bicycles, motorcycles, or other large items outside. These tools include sledge hammers, acetylene cutting torches, saws, grinders and the like. In addition to these tools, the bolt cutter is a favored tool of burglars for cutting padlocks because of its portability and the fact that it can be used quickly and quietly allowing pilferage even in front of busy retail hardware stores in the middle of the day.
Retail products locked with a chain or cable are typically secured by a padlock that attaches the two open ends of the chain or cable to complete a circle that inhibits unwarranted removal of a retail item that has the securing connector threaded through it such that the item cannot be freely moved beyond a certain distance. Likewise, a gate can be secured by a chain and padlock by wrapping the chain around the swinging end of the gate and the post or pole to which it can be latched. In protecting a padlock used in this context, it is desirable to keep the lock guard relatively small to make it difficult for thieves to access the lock, yet sufficiently large so that the securing padlock's shackle is retained within the lock guard to minimize ready access. It is also desirable to provide a universal device that is not designed for a particular style cable or chain but is universally suitable for use with most chains or looped cables and most brands of padlocks.
For ages, two basic designs of lock boxes having four walls and a top have been used. One inconvenient design was a large box with a loop or bar inside the box for attaching the padlock and without an abutment as in the present invention. The chain or cable being locked was brought up through the bottom of the lock box. This box was inconvenient for two reasons. First, the user was forced to run the chain or cable up through the bottom of the box and could not see the relative position of the ends of the chain or cable once they were inside the box. This made capturing the cable or chain with the padlock difficult. Second, in order to lock the padlock, the user was required to reach inside the lock box. This was difficult and required the lock box to be larger than the present invention, which has an abutment for locking the padlock. The second design was comprised of a box fixed to a first door with a separate protruding element, typically bent, attached to a second door. The protruding element could be inserted into the box through a slot or opening in the back of the box on the first door and secured therein with a padlock. This design cannot be used in a free-standing environment. Thus there is a need for a convenient device for protecting padlocks used to secure the ends of connectors such as chains or cables where the lock is not attached to a bracket, latch, or other solid mounting surface.
Various attempts have been made to protect padlocks over the years, although most address the situation in which the padlock is locked to a wall or latch. Examples of such devices include those disclosed in U.S. Pat. No. 1,220,941 to Bowers, U.S. Pat. No. 1,244,404 to Ankovitz, U.S. Pat. No. 3,392,555 to Beaver, U.S. Pat. Nos. 4,581,907 and 4,898,008 to Eberly, and U.S. Pat. No. 6,622,533 to Santini.
Further attempts to protect locks are directed to bolt seals, as in U.S. Pat. No. 6,036,240 to Hamilton. Some attempts have been made to protect padlocks not secured to a door latch. Examples of such attempts include the devices disclosed in U.S. Pat. No. 3,808,847 to Vesely, U.S. Pat. No. 4,920,772 to Denison, and U.S. Pat. No. 7,003,989 to St. James. None of these devices, however, achieves the results of the present invention.
SUMMARY OF THE INVENTION
The herein disclosed lock guard shrouds the padlock's shackle and sides when fully engaged and secured so as to protect the lock from unauthorized tampering when securing a connecting device such as a cable or chain. The lock guard also protects the cable or chain at its point of connection with the padlock shackle. Moreover, the present invention protects the padlock without the benefit of a latch or solid mounting surface. With the present invention, in just a few seconds, a person can secure a swing gate or a number of free-standing, chained-together items with a padlock and at the same time protect the padlock from tampering.
The lock guard is specifically dimensioned to prevent access to the sides of the padlock and shackle through the lock guard's open bottom. That is, the lateral dimensions of the lock guard make it impossible for a thief to place a bolt cutter, a grinder, or even his/her hand within the lock guard. The lock guard does not however, obstruct access to the keyhole in the padlock and thus the padlock can be easily unlocked with the key. The lock guard can have side holes though which a securing connector, such as a chain, can be threaded and placed over the retainer tab, which is a shelf or plate in the lock guard with a hole in it dimensioned to receive the shackle of the lock. The lock can then be placed inside the lock guard, threaded through the ends of the securing connector and the retainer tab, and locked. To aid in locking the lock once it is in place, an abutment can be added above the retainer tab.
Another feature of the present invention is that it can be used with padlocks equipped with either standard or elongated shackles. For padlocks having elongated shackles, by providing a narrow vertical slot in the top wall, the lock guard can be used without expanding the lateral dimensions of the lock guard, which would make the sides and shackle of the padlock accessible and thus more vulnerable. The slot in the top wall allows the elongated shackle to temporarily extend out of the lock guard when the padlock is being installed. This allows the shackle to be raised above the retainer tab. Once the padlock is locked inside the lock guard, the shackle cannot be raised and pushed through the slot in the top wall.
In addition to the top slot, there is an additional slot in the front wall of the lock guard that permits the user to visually monitor the positions of the padlock, shackle, and the ends of the securing connector, when the padlock is being installed within the lock guard. The shackle must be threaded through the ends of the securing connector (e.g. the chain links at the ends of a chain or loops at the end of a cable) as well as through the retainer tab and the viewing slot facilitates this task.
Importantly, the top slot and front slot are sufficiently narrow to prevent insertion of an adult human finger or hand into the lock guard. Conveniently, the overall design of the lock guard is such that users can install a padlock in the lock guard without putting their hands into the lock guard. Additionally, the slots and openings in the lock guard are not large enough to permit a thief to get to the shackle of the padlock with a bolt cutter or grinding tool.
In another embodiment of the invention, the walls of the lock guard are without slots and the retainer tab is vertical instead of horizontal. With the retainer tab vertical, the upper perimeter of the hole in the retainer tab through which the shackle of the lock is threaded acts as an abutment to assist in locking the lock.
Accordingly, the present invention is compatible with and protects a broad range of padlocks, including padlocks with extended shackles, and protects the connecting device (e.g., a cable or chain) attached to the padlock's shackle, at the point of connection between the connecting device and the shackle.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated in the accompanying drawings, in which:
FIG. 1 is a perspective view of the outside of the lock guard according to one embodiment of the invention;
FIG. 2 is another perspective view of the lock guard according to one embodiment of the invention with portions of the housing cut-away to afford a view of the inside of the lock guard;
FIG. 3 is the same cut-away view of the lock guard as shown in FIG. 2 , but with the addition of a chain secured with a padlock protected by the lock guard;
FIG. 4 is a perspective cut-away view of another embodiment of the invention; and
FIG. 5 is the same cut-away view of the lock guard as shown in FIG. 4 , but with the addition of a chain secured with a padlock protected by the lock guard.
DETAILED DESCRIPTION OF EMBODIMENTS
As illustrated in FIG. 1 , the lock guard 11 consists of five walls: a front wall 13 , side walls 12 and 14 , a rear wall 15 , and a top wall 16 . Instead of having a sixth side or bottom wall, there is a bottom opening 25 . Side walls 12 and 14 have openings 21 and 23 , respectively. Openings 21 and 23 allow the respective ends of the securing connector (e.g., chain or cable, etc.) to be inserted into and removed from the lock guard 11 so the ends can be secured to the shackle of the padlock ( FIG. 3 ). In this particular embodiment of the present invention, top wall 16 has an elongated slot 24 for temporary reception of the shackle of the padlock when the padlock is being installed in the lock guard 11 . Slot 24 allows the lock guard 11 to be used with padlocks having elongated shackles without increasing the size of the lock guard 11 .
FIG. 2 is a perspective view of the lock guard 11 shown in FIG. 1 with portions of sides 14 and 16 removed and all of side 15 removed to show the inside of lock guard 11 . The four side walls 12 , 13 , 14 , and 15 , along with top wall 16 , form a cavity 26 that is accessible through bottom opening 25 . Inside cavity 26 is a retainer tab 41 (located immediately below openings 21 and 23 in side walls 12 and 14 ).
Retainer tab 41 has at least three functions. First, having a hole therein dimensioned to receive the shackle of the padlock, it serves as the point of connection for the padlock. Second, when the retainer tab is permanently fastened to side walls 12 and 14 and front wall 13 , it serves to reinforce the lock guard 11 . Third, in an embodiment of the present invention in which retainer tab 41 has spacer bars 43 and 44 defining a gap 46 , retainer tab 41 and spacer bars 43 and 44 serve to prevent the shackle 32 from being brought sufficiently close to openings 21 and 23 that it could be cut with a bolt cutter or other tool (see FIG. 3 ). Note also that the opening 42 in retainer tab 41 is located laterally in the center of retainer tab 41 so that a user can see the shackle and its position with respect to retainer tab 41 through slots 22 and 24 while securing the padlock to the lock guard 11 .
Cavity 26 can also contain an abutment 45 . Abutment 45 is located above front wall opening 22 and below top wall 16 . Abutment 45 serves as a surface against which the shackle of the padlock can be pushed when the user locks the padlock inside the lock guard 11 . Similar to retainer tab 41 , abutment 45 can be secured to side walls 12 and 14 as well as front wall 13 , and extends in a rearward direction for a distance shorter than the full width of opening 42 .
FIG. 3 is a perspective cut-away like FIG. 2 but, unlike FIG. 2 , shows a padlock 31 and a securing connector, a chain 51 . As shown in FIG. 3 , padlock 31 secures a connecting device, such as chain 51 , within the cavity 26 of lock guard 11 . To lock the padlock 31 inside lock guard 11 , the user inserts the padlock 31 , with the padlock's shackle 32 in the open position (not shown), through the bottom opening 25 of the lock guard and into cavity 26 . The shackle 32 of the padlock 31 is then raised above vertical gap 46 as formed by the left spacer 43 and right spacer 44 of the horizontal retainer tab 41 . If necessary, the shackle 32 can extend through elongated slot 24 of top wall 16 ( FIG. 1 ) to ensure that the shackle 32 is above retainer tab 41 . Connector ends 52 and 53 of chain 51 are placed through the side wall openings 21 and 23 and positioned on top of retainer tab 41 , as shown in FIG. 3 . The open shackle 32 is then threaded through securing device ends 52 and 53 and opening 42 of retainer tab 41 . The lock body 33 is then rotated to align the lock body 33 with the shackle 32 . The padlock 31 is then raised so that the top curve of the shackle 32 bears on the abutment 45 permitting padlock 31 to be locked. The securing device ends 52 and 53 and padlock 31 are then locked securely within lock guard 11 . When needed, padlock 31 is easily unlocked (with a key) through bottom opening 25 .
FIG. 4 is a perspective cut-away of another embodiment 11 a of the invention. The walls 12 a , 13 a , and 14 a in this embodiment do not have slots or holes therethrough. Furthermore, retainer tab 41 a , instead of being horizontal within the lock guard 11 a , is vertical. The retainer tab 41 a can be attached to top wall 16 a and side walls 12 a and 14 a and be further supported with a support 47 spanning between retainer tab 41 a and the front wall 13 a . The retainer tab 41 a can have one or more openings 42 a through which the shackle of the lock can be threaded. The top edges 45 a of openings 42 a act as abutments against which the shackle 32 a of the padlock 31 a can be forced, making locking of the padlock 31 a within the device 11 a very easy.
FIG. 5 is a perspective cut-away of an embodiment 11 a of the invention similar to that shown in FIG. 4 having a vertical retainer tab 41 a . Here, as in FIG. 3 , a padlock 31 a and connector 51 a are shown secured within the invention 11 a . To lock the padlock 31 a within the invention 11 a , the user threads the ends 52 a and 53 a through the shackle 32 a of the padlock 31 a and inserts the padlock 31 a into the invention 11 a with the shackle 32 a in the unlocked and open position (not shown). The shackle 32 a is then threaded through hole 42 a in retainer tab 41 a and the padlock 31 a can then be locked. As explained above, the top edge 45 a of hole 42 a acts as an abutment against which the top curve of shackle 32 a can be forced to lock the padlock 31 a . As with the other embodiments of the invention herein disclosed, the padlock 31 a can be easily removed with a key as the bottom of the lock 33 a is accessible through the bottom 25 a of the device 11 a.
As shown in FIGS. 1 and 2 , side walls 14 and 12 have top halves 62 and 72 , bottom halves 64 and 74 , fore edges 66 and 76 , and aft edges 68 and 78 , respectively. Top halves 62 and 72 have top edges 70 and 80 , respectively, front wall 13 has a top edge 82 , and back wall 15 has a top edge 84 . Finally, slots 22 and 24 have widths 90 and 92 .
Having hereby described the subject matter of the present invention, it should be apparent that many substitutions, modifications, and variations of the invention are possible in light of the above teachings. It is therefore to be understood that the invention as taught and described herein is only to be limited to the extent of the breadth and scope of the appended claims. | A lock guard protects a padlock with a shackle and the ends of a securing connector. The device comprises a five-sided housing with an open bottom. Two opposing sides of the housing have opposing openings therethrough for inserting the ends of the securing connector. Inside the housing is a retaining tab having an opening therethrough dimensioned to receive the end of the shackle. The housing can also contain an abutment providing a surface against which to drive the top of the shackle when locking the padlock within the lock guard. When the retainer tab is vertical, the top edge of the hole in the retainer tab can act as an abutment. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application No. 08/444,625 filed May 19, 1995, abandoned, which is a divisional of U.S. application No. 08/243,545, filed May 11, 1994, now U.S. Pat. No. 5,554,512 issued Sep. 6, 1996, which is a continuation-in-part of U.S. application No. 08/209,502, filed Mar. 7, 1994, abandoned, which is a continuation-in-part of U.S. application No. 08/162,407, filed Dec. 3, 1993, abandoned, which is a continuation-in-part of U.S. application No. 08/111,758 filed Aug. 25, 1993, abandoned, which is a continuation-in-part of U.S. application No. 08/106,463, filed Aug. 12, 1993, abandoned, which is a continuation-in-part of U.S. application No. 08/068,394, filed May 24, 1993.
FIELD OF THE INVENTION
The present invention relates to mammalian flt3-ligands, the nucleic acids encoding such ligands, processes for production of recombinant flt3-ligands, pharmaceutical compositions containing such ligands, and their use in various therapies.
BACKGROUND OF THE INVENTION
Blood cells originate from hematopoietic stem cells that become committed to differentiate along certain lineages, i.e., erythroid, megakaryocytic, granulocytic, monocytic, and lymphocytic. Cytokines that stimulate the proliferation and maturation of cell precursors are called colony stimulating factors ("CSFs"). Several CSFs are produced by T-lymphocytes, including interleukin-3 ("IL-3"), granulocyte-monocyte CSF (GM-CSF), granulocyte CSF (G-CSF), and monocyte CSF (M-CSF). These CSFs affect both mature cells and stem cells. Heretofore no factors have been discovered that are able to predominantly affect stem cells.
Tyrosine kinase receptors ("TKRs") are growth factor receptors that regulate the proliferation and differentiation of a number of cells (Yarden, Y. & Ullrich, A. Annu. Rev. Biochem., 57, 443-478, 1988; and Cadena, D. L. & Gill, G. N. FASEB J., 6, 2332-2337, 1992). Certain TKRs function within the hematopoietic system. For example, signaling through the colony-stimulating factor type 1 ("CSF-1"), receptor c-fms regulates the survival, growth and differentiation of monocytes (Stanley et al., J. Cell Biochem., 21, 151-159, 1983). Steel factor ("SF", also known as mast cell growth factor, stem cell factor or kit ligand), acting through c-kit, stimulates the proliferation of cells in both myeloid and lymphoid compartments.
Flt3 (Rosnet et al. Oncogene, 6, 1641-1650, 1991) and flk-2 (Matthews et al., Cell, 65, 1143-1152, 1991) are variant forms of a TKR that is related to the c-fms and c-kit receptors. The flk-2 gene product is expressed on hematopoietic and progenitor cells, while the flt3 gene product has a more general tissue distribution. The flt3 and flk-2 receptor proteins are similar in amino acid sequence and vary at two amino acid residues in the extracellular domain and diverge in a 31 amino acid segment located near the C-termini (Lyman et al., Oncogene, 8, 815-822, 1993).
Flt3-ligand ("flt3-L") has been found to regulate the growth and differentiation of progenitor and stem cells and is likely to possess clinical utility in treating hematopoietic disorders, in particular, aplastic anemia and myelodysplastic syndromes. Additionally, flt3-L will be useful in allogeneic, syngeneic or autologous bone marrow transplants in patients undergoing cytoreductive therapies, as well as cell expansion. Flt3-L will also be useful in gene therapy and progenitor and stem cell mobilization systems.
Cancer is treated with cytoreductive therapies that involve administration of ionizing radiation or chemical toxins that kill rapidly dividing cells. Side effects typically result from cytotoxic effects upon normal cells and can limit the use of cytoreductive therapies. A frequent side effect is myelosuppression, or damage to bone marrow cells that give rise to white and red blood cells and platelets. As a result of myelosuppression, patients develop cytopenia, or blood cell deficits, that increase risk of infection and bleeding disorders.
Cytopenias increase morbidity, mortality, and lead to under-dosing in cancer treatment. Many clinical investigators have manipulated cytoreductive therapy dosing regimens and schedules to increase dosing for cancer therapy, while limiting damage to bone marrow. One approach involves bone marrow or peripheral blood cell transplants in which bone marrow or circulating hematopoietic progenitor or stem cells are removed before cytoreductive therapy and then reinfused following therapy to restore hematopoietic function. U.S. Pat. No. 5,199,942, incorporated herein by reference, describes a method for using GM-CSF, L-3, SF, GM-CSF/IL-3 fusion proteins, erythropoietin ("EPO") and combinations thereof in autologous transplantation regimens.
High-dose chemotherapy is therapeutically beneficial because it can produce an increased frequency of objective response in patients with metastatic cancers, particularly breast cancer, when compared to standard dose therapy. This can result in extended disease-free remission for some even poor-prognosis patients. Nevertheless, high-dose chemotherapy is toxic and many resulting clinical complications are related to infections, bleeding disorders and other effects associated with prolonged periods of myelosuppression.
Myelodysplastic syndromes are stem cell disorders characterized by impaired cellular maturation, progressive pancytopenia, and functional abnormalities of mature cells. They have also been characterized by variable degrees of cytopenia, ineffective erythropoiesis and myelopoiesis with bone marrow cells that are normal or increased in number and that have peculiar morphology. Bennett et. al. (Br. J. Haematol. 1982; 51: 189-199) divided these disorders into five subtypes: refractory anemia, refractory anemia with ringed sideroblasts, refractory anemia with excess blasts, refractory anemia with excess blasts in transformation, and chronic myelomonocytic leukemia. Although a significant percentage of these patients develop acute leukemia, a majority die from infectious or hemorrhagic complications. Treatment of theses syndromes with retinoids, vitamin D, and cytarabine has not been successful. Most of the patients suffering from these syndromes are elderly and are not suitable candidates for bone marrow transplantation or aggressive antileukemic chemotherapy.
Aplastic anemia is another disease entity that is characterized by bone marrow failure and severe pancytopenia. Unlike myelodysplastic syndrome, the bone marrow is acellular or hypocellular in this disorder. Current treatments include bone marrow transplantation from a histocompatible donor or immunosuppressive treatment with antithymocyte globulin (ATG). Similarly to myelodysplastic syndrome, most patients suffering from this syndrome are elderly and are unsuitable for bone marrow transplantation or for aggressive antileukemic chemotherapy. Mortality in these patients is exceedingly high from infectious or hemorrhagic complications.
Anemia is common in patients with acquired immune deficiency syndrome (AIDS). The anemia is usually more severe in patients receiving zidovudine therapy. Many important retroviral agents, anti-infectives, and anti-neoplastics suppress erythropoiesis. Recombinant EPO has been shown to normalize the patient's hematocrit and hemaoglobin levels, however, usually very high doses are required. A growth factor that stimulates proliferation of the erythroid lineage could be used alone or in combination with EPO or other growth factors to treat such patients and reduce the number of transfusions required. A growth factor that could also increase the number of T cells would find particular use in treating AIDS patients.
SUMMARY OF THE INVENTION
The present invention pertains to biologically active flt3-ligand (flt3-L) as an isolated or homogeneous protein. In addition, the invention is directed to isolated DNAs encoding flt3-L and to expression vectors comprising a cDNA encoding flt3-L. Within the scope of this invention are host cells that have been transfected or transformed with expression vectors that comprise a cDNA encoding flt3-L, and processes for producing flt3-L by culturing such host cells under conditions conducive to expression of flt3-L.
Flt3-L can be used to prepare pharmaceutical compositions to be used in allogeneic, syngeneic or autologous transplantation methods. Pharmaceutical compositions may comprise flt3-L alone or in combination with other growth factors, such as interleukins, colony stimulating factors, protein tyrosine kinases and cytokines.
The invention includes methods of using flt3-L compositions in gene therapy and in treatment of patients suffering from myelodysplastic syndrome, aplastic anemia, HIV infection (AIDS) and cancers, such as breast cancer, lymphoma, small cell lung cancer, multiple myeloma, neuroblastoma, acute leukemia, testicular tumors, and ovarian cancer.
The present invention also pertains to antibodies, and in particular monoclonal antibodies, that are immunoreactive with flt3-L. Fusion proteins comprising a soluble portion of flt3-L and the constant domain of an immunoglobulin protein are also embodied in the invention.
The present invention also is directed to the use of flt3-L in peripheral blood progenitor or stem cell transplanation procedures. Typically, peripheral blood progenitor cells or stem cells are removed from a patient prior to myelosuppressive cytoreductive therapy, and then readministered to the patient concurrent with or following cytoreductive therapy to counteract the myelosuppressive effects of such therapy. The present invention provides for the use of an effective amount of flt3-L in at least one of the following manners: (i) flt3-L is administered to the patient prior to collection of the progenitor or stem cells to increase or mobilize the numbers of such circulating cells; (ii) following collection of the patient's progenitor or stem cells, flt3-L is used to expand such cells ex vivo; and (iii) flt3-L is administered to the patient following transplantation of the collected progenitor or stem cells to facilitate engraftment thereof. The transplantation method of the invention can further comprise the use of an effective amount of a cytokine in sequential or concurrent combination with the flt3-L. Such cytokines include, but are not limited to interleukins ("IL") IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-11, IL-12, IL-13, IL-14 or IL-15, a CSF selected from the group consisting of G-CSF, GM-CSF, M-CSF, or GM-CSF/IL-3 fusions, or other growth factors such as CSF-1, SF, EPO, leukemia inhibitory factor ("LIF") or fibroblast growth factor ("FGF"). The flt3-L is also useful in the same way for syngeneic or allogeneic transplantations.
The invention further includes a progenitor or stem cell expansion media comprising cell growth media, autologous serum, and flt3-L alone or in combination with a cytokine from the group listed above.
The invention further includes the use of flt3-L to expand progenitor or stem cells collected from umbilical cord blood. The expansion may be performed with flt3-L alone or in sequential or concurrent combination with a cytokine from the group listed above.
The invention further includes the use of flt3-L in gene therapy. Flt3-L permits proliferation and culturing of the early hematopoietic progenitor or stem cells that are to be transfected with exogenous DNA for use in gene therapy. Alternatively, a cDNA encoding flt3-L may be transfected into cells in order to ultimately deliver its gene product to the targeted cell or tissue.
In addition, the invention includes the use of flt3-L to stimulate production of erythroid cells in vivo for the treatment of anemia. Such use comprises administering flt3-L to the patient in need of such erythroid cell stimulation in conjunction with or following cytoreductive therapy. The treatment can include co-administration of another growth factor selected from the cytokines from the group listed above. Preferred cytokines for use in this treatment include EPO, IL-3, G-CSF and GM-CSF. Such treatment is especially useful for AIDS patients, and preferably for AIDS patients receiving AZT therapy.
Since flt3-L stimulates the production of stem cells, other non-hematopoietic stem cells bearing flt3 receptors can be affected by the flt3-L of the invention. Flt3-L is useful in in vitro fertilization procedures and can be used in vivo in the treatment of infertility conditions. In the gut, the flt3 ligand is useful in treating intestinal damage resulting from irradiation or chemotherapy. The flt3-L can be also used to treat patients infected with the human immunodeficiency virus (HIV). Such treatment would encompass the administration of the flt3-L to stimulate in vivo production, as well as the ex vivo expansion, of T cells and erythroid cells. Such treatment can prevent the deficiency of T cells, in particular CD4-positive T cells, and may elevate the patient's immune reponse against the virus, thereby improving the quality of life of the patient. The flt3-L can be used to stimulate the stem cells that lead to the development of hair follicles, thereby promoting hair growth.
In addition, flt3-L can be bound to a solid phase matrix and used to affinity-purify or separate cells that express flt3 on their cell surface. The invention encompasses separating cells having the flt3 receptor on the surface thereof from a mixture of cells in solution, comprising contacting the cells in the mixture with a contacting surface having a flt3-binding molecule thereon, and separating the contacting surface and the solution. Once separated, the cells can be expanded ex vivo using flt3-L and administered to a patient.
DETAILED DESCRIPTION OF THE INVENTION
A cDNA encoding murine flt3-L has been isolated and is disclosed in SEQ ID NO:1. A cDNA encoding human flt3-L also has been isolated and is disclosed in SEQ ID NO:5. This discovery of cDNAs encoding murine and human flt3-L enables construction of expression vectors comprising cDNAs encoding flt3-L; host cells transfected or transformed with the expression vectors; biologically active murine and human flt3-L as homogeneous proteins; and antibodies immunoreactive with the murine and the human flt3-L.
Flt3-L is useful in the enhancement, stimulation, proliferation or growth of cells expressing the flt3 receptor, including non-hematopoietic cells. Since the flt3 receptor is found in the brain, placenta, and tissues of nervous and hematopoietic origin, and finds distribution in the testis, ovaries, lymph node, spleen, thymus and fetal liver, treatment of a variety of conditions associated with tissue damage thereof is possible. While not limited to such, particular uses of the flt3-L are described infra.
As used herein, the term "flt3-L" refers to a genus of polypeptides that bind and complex independently with flt3 receptor found on progenitor and stem cells. The term "flt3-L" encompasses proteins having the amino acid sequence 1 to 231 of SEQ ID NO:2 or the amino acid sequence 1 to 235 of SEQ ID NO:6, as well as those proteins having a high degree of similarity or a high degree of identity with the amino acid sequence 1 to 231 of SEQ ID NO:2 or the amino acid sequence 1 to 235 of SEQ ID NO:6, and which proteins are biologically active and bind the flt3 receptor. In addition, the term refers to biologically active gene products of the DNA of SEQ ID NO:1 or SEQ ID NO:5. Further encompassed by the term "flt3-L" are the membrane-bound proteins (which include an intracellular region, a membrane region, and an extracellular region), and soluble or truncated proteins which comprise primarily the extracellular portion of the protein, retain biological activity and are capable of being secreted. Specific examples of such soluble proteins are those comprising the sequence of amino acids 28-163 of SEQ ID NO:2 and amino acids 28-160 of SEQ ID NO:6.
The term "biologically active" as it refers to flt3-L, means that the flt3-L is capable of binding to flt3. Alternatively, "biologically active" means the flt3-L is capable of transducing a stimulatory signal to the cell through the membrane-bound flt3.
"Isolated" means that flt3-L is free of association with other proteins or polypeptides, for example, as a purification product of recombinant host cell culture or as a purified extract.
A "flt3-L variant" as referred to herein, means a polypeptide substantially homologous to native flt3-L, but which has an amino acid sequence different from that of native flt3-L (human, murine or other mammalian species) because of one or more deletions, insertions or substitutions. The variant amino acid sequence preferably is at least 80% identical to a native flt3-L amino acid sequence, most preferably at least 90% identical. The percent identity may be determined, for example, by comparing sequence information using the GAP computer program, version 6.0 described by Devereux et al. (Nucl. Acids Res. 12: 387, 1984) and available from the University of Wisconsin Genetics Computer Group (UWGCG). The GAP program utilizes the alignment method of Needleman and Wunsch (J. Mol. Biol. 48: 443, 1970), as revised by Smith and Waterman (Adv. Appl. Math 2: 482, 1981). The preferred default parameters for the GAP program include: (1) a unary comparison matrix (containing a value of 1 for identities and 0 for non-identities) for nucleotides, and the weighted comparison matrix of Gribskov and Burgess, Nucl. Acids Res. 14: 6745, 1986, as described by Schwartz and Dayhoff, eds., Atlas of Protein Sequence and Structure, National Biomedical Research Foundation, pp. 353-358, 1979; (2) a penalty of 3.0 for each gap and an additional 0.10 penalty for each symbol in each gap; and (3) no penalty for end gaps. Variants may comprise conservatively substituted sequences, meaning that a given amino acid residue is replaced by a residue having similar physiochemical characteristics. Examples of conservative substitutions include substitution of one aliphatic residue for another, such as Ile, Val, Leu, or Ala for one another, or substitutions of one polar residue for another, such as between Lys and Arg; Glu and Asp; or Gln and Asn. Other such conservative substitutions, for example, substitutions of entire regions having similar hydrophobicity characteristics, are well known. Naturally occurring flt3-L variants are also encompassed by the invention. Examples of such variants are proteins that result from alternate mRNA splicing events or from proteolytic cleavage of the flt3-L protein, wherein the flt3-L binding property is retained. Alternate splicing of mRNA may yield a truncated but biologically active flt3-L protein, such as a naturally occurring soluble form of the protein, for example. Variations attributable to proteolysis include, for example, differences in the N- or C-termini upon expression in different types of host cells, due to proteolytic removal of one or more terminal amino acids from the flt3-L protein (generally from 1-5 terminal amino acids).
The term "autologous transplantation" is described in U.S. Pat. No. 5,199,942, which is incorporated herein by reference. Briefly, the term means a method for conducting autologous hematopoietic progenitor or stem cell transplantation, comprising: (1) collecting hematopoietic progenitor cells or stem cells from a patient prior to cytoreductive therapy; (2) expanding the hematopoietic progenitor cells or stem cells ex vivo with flt3-L to provide a cellular preparation comprising increased numbers of hematopoietic progenitor cells or stem cells; and (3) administering the cellular preparation to the patient in conjunction with or following cytoreductive therapy. Progenitor and stem cells may be obtained from peripheral blood harvest or bone marrow explants. Optionally, one or more cytokines, selected from the group listed above can be combined with flt3-L to aid in the proliferation of particular hematopoietic cell types or affect the cellular function of the resulting proliferated hematopoietic cell population. Of the foregoing, SF, IL-1, IL-3, EPO, G-CSF, GM-CSF and GM-CSF/IL-3 fusions are preferred, with G-CSF, GM-CSF and GM-CSF/IL-3 fusions being especially preferred. The term "allogeneic transplantation" means a method in which bone marrow or peripheral blood progenitor cells or stem cells are removed from a mammal and administered to a different mammal of the same species. The term "syngeneic transplantation" means the bone marrow transplantation between gentically identical mammals.
The transplantation method of the invention described above optionally comprises a preliminary in vivo procedure comprising administering flt3-L alone or in sequential or concurrent combination with a recruitment growth factor to a patient to recruit the hematopoietic cells into peripheral blood prior to their harvest. Suitable recruitment factors are listed above, and preferred recruitment factors are flt3-L, SF, IL-1 and IL-3.
The method of the invention described above optionally comprises a subsequent in vivo procedure comprising administering flt3-L alone or in sequential or concurrent combination with an engraftment growth factor to a patient following transplantation of the cellular preparation to facilitate engraftment and augment proliferation of engrafted hematopoietic progenitor or stem cells from the cellular preparation. Suitable engraftment factors are listed above, and the preferred engraftment factors are GM-CSF, G-CSF, IL-3, IL-1, EPO and GM-CSF/IL-3 fusions.
The invention further includes a progenitor or stem cell expansion media comprising cell growth media, autologous serum, and flt3-L alone or in combination with a cytokine growth factor from the list above. Preferred growth factors are SF, GM-CSF, IL-3, IL-1, G-CSF, EPO, and GM-CSF/IL-3 fusions.
In particular, flt3-L can be used to stimulate the proliferation of hematopoietic and non-hematopoietic stem cells. Such stimulation is beneficial when specific tissue damage has occurred to these tissues. As such, flt3-L may be useful in treating neurological damage and may be a growth factor for nerve cells. It is probable that flt3-L would be useful in in vitro fertilization procedures and likely can be used in vivo in the treatment of infertility conditions. Flt3-L would be useful in treating intestinal damage resulting from irradiation or chemotherapy. Since the flt3 receptor is distributed on stem cells leading to the development of hair follicles, flt3-L would likely be useful to promote hair growth.
Since flt3-L has been shown to stimulate T cell proliferation as well as erythrocytes (see Examples, infra), flt3-L finds use in the treatment of patients infected with the human immunodeficiency virus (HIV). Such treatment would encompass the administration of flt3-L to stimulate in vivo production, as well as the ex vivo expansion, of T cells. In addition, flt3-L can prevent the deficiency of CD4 + T cells. Such treatment may elevate or maintain a patient's immune reponse against the virus, thereby improving or maintaining a patient's quality of life. In addition, such in vivo treatment would stimulate cells of the erythroid lineage, thereby improving a patient's hematocrit and hemaglobin levels. Flt3-L can be administered in this setting alone or in sequential or concurrent combination with cytokines selected from the group listed above.
Flt3-L is useful in gene therapy due to its specificity for progenitor and stem cells. Gene therapy involves administration of exogenous DNA-transfected cells to a host that are allowed to engraft. See e.g., Boggs, International J. Cell Cloning, 8: 80-96, (1990); Kohn et. al., Cancer Invest., 7 (2): 179-192 (1989); Lehn, Bone Marrow Transpl., 5: 287-293 (1990); and Verma, Scientific American, pp. 68-84 (1990). Using gene therapy methods known in the art, a method of transferring a gene to a mammal comprises the steps of (a) culturing early hematopoietic cells in media comprising flt3-L alone or in sequential or concurrent combination with a cyokine selected from the group listed above; (b) transfecting the cultured cells from step (a) with the exogenous gene; and (c) administering the transfected cells to the mammal. Within this method is the novel method of transfecting progenitor or stem cells with a gene comprising the steps of: (a) and (b) above. Furthermore, using the same or simolar methods, the cDNA encoding the flt3-L can be transfected into such delivery cells to deliver the flt3-L gene product to the targetted tissue.
Example 1 describes the construction of a novel flt3:Fc fusion protein utilized in the screening for flt3-L. Other antibody Fc regions may be substituted for the human IgG1 Fc region described in Example 1. Other suitable Fc regions are those that can bind with high affinity to protein A or protein G, and include the Fc region of human IgG1 or fragments of the human or murine IgG1 Fc region, e.g., fragments comprising at least the hinge region so that interchain disulfide bonds will form. The flt3:Fc fusion protein offers the advantage of being easily purified. In addition, disulfide bonds form between the Fc regions of two separate fusion protein chains, creating dimers. The dimeric flt3:Fc receptor was chosen for the potential advantage of higher affinity binding of flt3-L, in view of the possibility that the ligand being sought would be multimeric.
As described supra., an aspect of the invention is soluble flt3-L polypeptides. Soluble flt3-L polypeptides comprise all or part of the extracellular domain of a native flt3-L but lack the transmembrane region that would cause retention of the polypeptide on a cell membrane. Soluble flt3-L polypeptides advantageously comprise the native (or a heterologous) signal peptide when initially synthesized to promote secretion, but the signal peptide is cleaved upon secretion of flt3-L from the cell. Soluble flt3-L polypeptides encompassed by the invention retain the ability to bind the flt3 receptor. Indeed, soluble flt3-L may also include part of the transmembrane region or part of the cytoplasmic domain or other sequences, provided that the soluble flt3-L protein can be secreted.
Soluble flt3-L may be identified (and distinguished from its non-soluble membrane-bound counterparts) by separating intact cells which express the desired protein from the culture medium, e.g., by centrifugation, and assaying the medium (supernatant) for the presence of the desired protein. The presence of flt3-L in the medium indicates that the protein was secreted from the cells and thus is a soluble form of the desired protein.
Soluble forms of flt3-L possess many advantages over the native bound flt3-L protein. Purification of the proteins from recombinant host cells is feasible, since the soluble proteins are secreted from the cells. Further, soluble proteins are generally more suitable for intravenous administration.
Examples of soluble flt3-L polypeptides include those comprising a substantial portion of the extracellular domain of a native flt3-L protein. Such soluble mammalian flt3-L proteins comprise amino acids 28 through 188 of SEQ ID NO:2 or amino acids 28 through 182 of SEQ ID NO:6. In addition, truncated soluble flt3-L proteins comprising less than the entire extracellular domain are included in the invention. Such truncated soluble proteins are represented by the sequence of amino acids 28-163 of SEQ ID NO:2, and amino acids 28-160 of SEQ ID NO:6. When initially expressed within a host cell, soluble flt3-L may additionally comprise one of the heterologous signal peptides described below that is functional within the host cells employed. Alternatively, the protein may comprise the native signal peptide, such that the mammalian flt3-L comprises amino acids 1 through 188 of SEQ ID NO:2 or amino acids 1 through 182 of SEQ ID NO:6. In one embodiment of the invention, soluble flt3-L was expressed as a fusion protein comprising (from N- to C-terminus) the yeast α factor signal peptide, a FLAG® peptide described below and in U.S. Pat. No. 5,011,912, and soluble flt3-L consisting of amino acids 28 to 188 of SEQ ID NO:2. This recombinant fusion protein is expressed in and secreted from yeast cells. The FLAG® peptide facilitates purification of the protein, and subsequently may be cleaved from the soluble flt3-L using bovine mucosal enterokinase. Isolated DNA sequences encoding soluble flt3-L proteins are encompassed by the invention.
Truncated flt3-L, including soluble polypeptides, may be prepared by any of a number of conventional techniques. A desired DNA sequence may be chemically synthesized using techniques known per se. DNA fragments also may be produced by restriction endonuclease digestion of a full length cloned DNA sequence, and isolated by electrophoresis on agarose gels. Linkers containing restriction endonuclease cleavage site(s) may be employed to insert the desired DNA fragment into an expression vector, or the fragment may be digested at cleavage sites naturally present therein. The well known polymerase chain reaction procedure also may be employed to amplify a DNA sequence encoding a desired protein fragment. As a further alternative, known mutagenesis techniques may be employed to insert a stop codon at a desired point, e.g., immediately downstream of the codon for the last amino acid of the extracellular domain.
In another approach, enzymatic treatment (e.g., using Bal 31 exonuclease) may be employed to delete terminal nucleotides from a DNA fragment to obtain a fragment having a particular desired terminus. Among the commercially available linkers are those that can be ligated to the blunt ends produced by Bal 31 digestion, and which contain restriction endonuclease cleavage site(s). Alternatively, oligonucleotides that reconstruct the N- or C-terminus of a DNA fragment to a desired point may be synthesized and ligated to the DNA fragment. The synthesized oligonucleotide may contain a restriction endonuclease cleavage site upstream of the desired coding sequence and position an initiation codon (ATG) at the N-terminus of the coding sequence.
As stated above, the invention provides isolated or homogeneous flt3-L polypeptides, both recombinant and non-recombinant. Variants and derivatives of native flt3-L proteins that retain the desired biological activity (e.g., the ability to bind flt3) may be obtained by mutations of nucleotide sequences coding for native flt3-L polypeptides. Alterations of the native amino acid sequence may be accomplished by any of a number of conventional methods. Mutations can be introduced at particular loci by synthesizing oligonucleotides containing a mutant sequence, flanked by restriction sites enabling ligation to fragments of the native sequence. Following ligation, the resulting reconstructed sequence encodes an analog having the desired amino acid insertion, substitution, or deletion.
Alternatively, oligonucleotide-directed site-specific mutagenesis procedures can be employed to provide an altered gene wherein predetermined codons can be altered by substitution, deletion or insertion. Exemplary methods of making the alterations set forth above are disclosed by Walder et al. (Gene 42: 133, 1986); Bauer et al. (Gene 37: 73, 1985); Craik (BioTechniques, January 1985, 12-19); Smith et al. (Genetic Engineering: Principles and Methods, Plenum Press, 1981); Kunkel (Proc. Natl. Acad. Sci. USA 82: 488, 1985); Kunkel et al. (Methods in Enzymol. 154: 367, 1987); and U.S. Pat. Nos. 4,518,584 and 4,737,462 all of which are incorporated by reference.
Flt3-L may be modified to create flt3-L derivatives by forming covalent or aggregative conjugates with other chemical moieties, such as glycosyl groups, lipids, phosphate, acetyl groups and the like. Covalent derivatives of flt3-L may be prepared by linking the chemical moieties to functional groups on flt3-L amino acid side chains or at the N-terminus or C-terminus of a flt3-L polypeptide or the extracellular domain thereof. Other derivatives of flt3-L within the scope of this invention include covalent or aggregative conjugates of flt3-L or its fragments with other proteins or polypeptides, such as by synthesis in recombinant culture as N-terminal or C-terminal fusions. For example, the conjugate may comprise a signal or leader polypeptide sequence (e.g. the α-factor leader of Saccharomyces) at the N-terminus of a flt3-L polypeptide. The signal or leader peptide co-translationally or post-translationally directs transfer of the conjugate from its site of synthesis to a site inside or outside of the cell membrane or cell wall.
Flt3-L polypeptide fusions can comprise peptides added to facilitate purification and identification of flt3-L. Such peptides include, for example, poly-His or the antigenic identification peptides described in U.S. Pat. No. 5,011,912 and in Hopp et al., Bio/Technology 6: 1204, 1988.
The invention further includes flt3-L polypeptides with or without associated native-pattern glycosylation. Flt3-L expressed in yeast or mammalian expression systems (e.g., COS-7 cells) may be similar to or significantly different from a native flt3-L polypeptide in molecular weight and glycosylation pattern, depending upon the choice of expression system. Expression of flt3-L polypeptides in bacterial expression systems, such as E. coli, provides non-glycosylated molecules.
Equivalent DNA constructs that encode various additions or substitutions of amino acid residues or sequences, or deletions of terminal or internal residues or sequences not needed for biological activity or binding are encompassed by the invention. For example, N-glycosylation sites in the flt3-L extracellular domain can be modified to preclude glycosylation, allowing expression of a reduced carbohydrate analog in mammalian and yeast expression systems. N-glycosylation sites in eukaryotic polypeptides are characterized by an amino acid triplet Asn-X-Y, wherein X is any amino acid except Pro and Y is Ser or Thr. The murine and human flt3-L proteins each comprise two such triplets, at amino acids 127-129 and 152-154 of SEQ ID NO:2, and at amino acids 126-128 and 150-152 of SEQ ID NO:6, respectively. Appropriate substitutions, additions or deletions to the nucleotide sequence encoding these triplets will result in prevention of attachment of carbohydrate residues at the Asn side chain. Alteration of a single nucleotide, chosen so that Asn is replaced by a different amino acid, for example, is sufficient to inactivate an N-glycosylation site. Known procedures for inactivating N-glycosylation sites in proteins include those described in U.S. Pat. No. 5,071,972 and EP 276,846, hereby incorporated by reference.
In another example, sequences encoding Cys residues that are not essential for biological activity can be altered to cause the Cys residues to be deleted or replaced with other amino acids, preventing formation of incorrect intramolecular disulfide bridges upon renaturation. Other equivalents are prepared by modification of adjacent dibasic amino acid residues to enhance expression in yeast systems in which KEX2 protease activity is present. EP 212,914 discloses the use of site-specific mutagenesis to inactivate KEX2 protease processing sites in a protein. KEX2 protease processing sites are inactivated by deleting, adding or substituting residues to alter Arg-Arg, Arg-Lys, and Lys-Arg pairs to eliminate the occurrence of these adjacent basic residues. Lys-Lys pairings are considerably less susceptible to KEX2 cleavage, and conversion of Arg-Lys or Lys-Arg to Lys-Lys represents a conservative and preferred approach to inactivating KEX2 sites. Both murine and human flt3-L contain two KEX2 protease processing sites at amino acids 216-217 and 217-218 of SEQ ID NO:2 and at amino acids 211-212 and 212-213 of SEQ ID NO:6, respectively.
Nucleic acid sequences within the scope of the invention include isolated DNA and RNA sequences that hybridize to the native flt3-L nucleotide sequences disclosed herein under conditions of moderate or severe stringency, and which encode biologically active flt3-L. Conditions of moderate stringency, as defined by Sambrook et al. Molecular Cloning: A Laboratory Manual, 2 ed. Vol. 1, pp. 1.101-104, Cold Spring Harbor Laboratory Press, (1989), include use of a prewashing solution of 5× SSC, 0.5% SDS, 1.0 mM EDTA (pH 8.0) and hybridization conditions of about 55 -- C, 5× SSC, overnight. Conditions of severe stringency include higher temperatures of hybridization and washing. The skilled artisan will recognize that the temperature and wash solution salt concentration may be adjusted as necessary according to factors such as the length of the probe.
Due to the known degeneracy of the genetic code wherein more than one codon can encode the same amino acid, a DNA sequence may vary from that shown in SEQ ID NO:1 and SEQ ID NO:5 and still encode an flt3-L protein having the amino acid sequence of SEQ ID NO:2 and SEQ ID NO:6, respectively. Such variant DNA sequences may result from silent mutations (e.g., occurring during PCR amplification), or may be the product of deliberate mutagenesis of a native sequence.
The invention provides equivalent isolated DNA sequences encoding biologically active flt3-L, selected from: (a) DNA derived from the coding region of a native mammalian flt3-L gene; (b) cDNA comprising the nucleotide sequence presented in SEQ ID NO:1 or SEQ ID NO:5; (c) DNA capable of hybridization to a DNA of (a) under moderately stringent conditions and which encodes biologically active flt3-L; and (d) DNA which is degenerate as a result of the genetic code to a DNA defined in (a), (b) or (c) and which encodes biologically active flt3-L. Flt3-L proteins encoded by such DNA equivalent sequences are encompassed by the invention.
DNA that are equivalents to the DNA sequence of SEQ ID NO:1 or SEQ ID NO:5, will hybridize under moderately stringent conditions to the native DNA sequence that encode polypeptides comprising amino acid sequences of 28-163 of SEQ ID NO:2 or 28-160 of SEQ ID NO:6. Examples of flt3-L proteins encoded by such DNA, include, but are not limited to, flt3-L fragments (soluble or membrane-bound) and flt3-L proteins comprising inactivated N-glycosylation site(s), inactivated KEX2 protease processing site(s), or conservative amino acid substitution(s), as described above. Flt3-L proteins encoded by DNA derived from other mammalian species, wherein the DNA will hybridize to the cDNA of SEQ ID NO:1 or SEQ ID NO:5, are also encompassed.
Variants possessing the requisite ability to bind flt3 receptor may be identified by any suitable assay. Biological activity of flt3-L may be determined, for example, by competition for binding to the ligand binding domain of flt3 receptor (i.e. competitive binding assays).
One type of a competitive binding assay for a flt3-L polypeptide uses a radiolabeled, soluble human flt3-L and intact cells expressing cell surface flt3 receptors. Instead of intact cells, one could substitute soluble flt3 receptors (such as a flt3:Fc fusion protein) bound to a solid phase through the interaction of a Protein A, Protein G or an antibody to the flt3 or Fc portions of the molecule, with the Fc region of the fusion protein. Another type of competitive binding assay utilizes radiolabeled soluble flt3 receptors such as a flt3:Fc fusion protein, and intact cells expressing flt3-L. Alternatively, soluble flt3-L could be bound to a solid phase to positively select flt3 expressing cells.
Competitive binding assays can be performed following conventional methodology. For example, radiolabeled flt3-L can be used to compete with a putative flt3-L homolog to assay for binding activity against surface-bound flt3 receptors. Qualitative results can be obtained by competitive autoradiographic plate binding assays, or Scatchard plots may be utilized to generate quantitative results.
Alternatively, flt3-binding proteins, such as flt3-L and anti-flt3 antibodies, can be bound to a solid phase such as a column chromatography matrix or a similar substrate suitable for identifying, separating or purifying cells that express the flt3 receptor on their surface. Binding of flt3-binding proteins to a solid phase contacting surface can be accomplished by any means, for example, by constructing a flt3-L:Fc fusion protein and binding such to the solid phase through the interaction of Protein A or Protein G. Various other means for fixing proteins to a solid phase are well known in the art and are suitable for use in the present invention. For example, magnetic microspheres can be coated with flt3-binding proteins and held in the incubation vessel through a magnetic field. Suspensions of cell mixtures containing hematopoietic progenitor or stem cells are contacted with the solid phase that has flt3-binding proteins thereon. Cells having the flt3 receptor on their surface bind to the fixed flt3-binding protein and unbound cells then are washed away. This affinity-binding method is useful for purifying, screening or separating such flt3-expressing cells from solution. Methods of releasing positively selected cells from the solid phase are known in the art and encompass, for example, the use of enzymes. Such enzymes are preferably non-toxic and non-injurious to the cells and are preferably directed to cleaving the cell-surface binding partner. In the case of flt3:flt3-L interactions, the enzyme preferably would cleave the flt3 receptor, thereby freeing the resulting cell suspension from the "foreign" flt3-L material. The purified cell population then may be expanded ex vivo prior to transplantation to a patient in an amount sufficient to reconstitute the patient's hematopoietic and immune system.
Alternatively, mixtures of cells suspected of containing flt3 + cells first can be incubated with a biotinylated flt3-binding protein. Incubation periods are typically at least one hour in duration to ensure sufficient binding to flt3. The resulting mixture then is passed through a column packed with avidin-coated beads, whereby the high affinity of biotin for avidin provides the binding of the cell to the beads. Use of avidin-coated beads is known in the art. See Berenson, et al. J. Cell. Biochem., 10D: 239 (1986). Wash of unbound material and the release of the bound cells is performed using conventional methods.
In the methods described above, suitable flt3-binding proteins are flt3-L, anti-flt3 antibodies, and other proteins that are capable of high-affinity binding of flt3. A preferred flt3-binding protein is flt3-L.
As described above, flt3-L of the invention can be used to separate cells expressing flt3 receptors. In an alternative method, flt3-L or an extracellular domain or a fragment thereof can be conjugated to a detectable moiety such as 125 I to detect flt3 expressing cells. Radiolabeling with 125 I can be performed by any of several standard methodologies that yield a functional 125 I-flt3-L molecule labeled to high specific activity. Or an iodinated or biotinylated antibody against the flt3 region or the Fc region of the molecule could be used. Another detectable moiety such as an enzyme that can catalyze a colorimetric or fluorometric reaction, biotin or avidin may be used. Cells to be tested for flt3 receptor expression can be contacted with labeled flt3-L. After incubation, unbound labeled flt3-L is removed and binding is measured using the detectable moiety.
The binding characteristics of flt3-L (including variants) may also be determined using the conjugated, soluble flt3 receptors (for example, 125 I-flt3:Fc) in competition assays similar to those described above. In this case, however, intact cells expressing flt3 receptors, or soluble flt3 receptors bound to a solid substrate, are used to measure the extent to which a sample containing a putative flt3-L variant competes for binding with a conjugated a soluble flt3 to flt3-L.
Other means of assaying for flt3-L include the use of anti-flt3-L antibodies, cell lines that proliferate in response to flt3-L, or recombinant cell lines that express flt3 receptor and proliferate in the presenvce of flt3-L. For example, the BAF/BO3 cell line lacks the flt3 receptor and is IL-3 dependent. (See Hatakeyama, et al., Cell, 59: 837-845 (1989)). BAF/BO3 cells transfected with an expression vector comprising the flt3 receptor gene proliferate in response to either IL-3 or flt3-L. An example of a suitable expression vector for transfection of flt3 is the pCAV/NOT plasmid, see Mosley et al., Cell, 59: 335-348 (1989).
Flt3-L polypeptides may exist as oligomers, such as covalently-linked or non-covalently-linked dimers or trimers. Oligomers may be linked by disulfide bonds formed between cysteine residues on different flt3-L polypeptides. In one embodiment of the invention, a flt3-L dimer is created by fusing flt3-L to the Fc region of an antibody (e.g., IgG1) in a manner that does not interfere with binding of flt3-L to the flt3-ligand-binding domain. The Fc polypeptide preferably is fused to the C-terminus of a soluble flt3-L (comprising only the extracellular domain). General preparation of fusion proteins comprising heterologous polypeptides fused to various portions of antibody-derived polypeptides (including the Fc domain) has been described, e.g., by Ashkenazi et al. (PNAS USA 88: 10535, 1991) and Byrn et al. (Nature 344: 677, 1990), hereby incorporated by reference. A gene fusion encoding the flt3-L:Fc fusion protein is inserted into an appropriate expression vector. Flt3-L:Fc fusion proteins are allowed to assemble much like antibody molecules, whereupon interchain disulfide bonds form between Fc polypeptides, yielding divalent flt3-L. If fusion proteins are made with both heavy and light chains of an antibody, it is possible to form a flt3-L oligomer with as many as four flt3-L extracellular regions. Alternatively, one can link two soluble flt3-L domains with a peptide linker.
Recombinant expression vectors containing a DNA encoding flt3-L can be prepared using well known methods. The expression vectors include a flt3-L DNA sequence operably linked to suitable transcriptional or translational regulatory nucleotide sequences, such as those derived from a mammalian, microbial, viral, or insect gene. Examples of regulatory sequences include transcriptional promoters, operators, or enhancers, an mRNA ribosomal binding site, and appropriate sequences which control transcription and translation initiation and termination. Nucleotide sequences are "operably linked" when the regulatory sequence functionally relates to the flt3-L DNA sequence. Thus, a promoter nucleotide sequence is operably linked to a flt3-L DNA sequence if the promoter nucleotide sequence controls the transcription of the flt3-L DNA sequence. The ability to replicate in the desired host cells, usually conferred by an origin of replication, and a selection gene by which transformants are identified, may additionally be incorporated into the expression vector.
In addition, sequences encoding appropriate signal peptides that are not naturally associated with flt3-L can be incorporated into expression vectors. For example, a DNA sequence for a signal peptide (secretory leader) may be fused in-frame to the flt3-L sequence so that flt3-L is initially translated as a fusion protein comprising the signal peptide. A signal peptide that is functional in the intended host cells enhances extracellular secretion of the flt3-L polypeptide. The signal peptide may be cleaved from the flt3-L polypeptide upon secretion of flt3-L from the cell.
Suitable host cells for expression of flt3-L polypeptides include prokaryotes, yeast or higher eukaryotic cells. Appropriate cloning and expression vectors for use with bacterial, fungal, yeast, and mammalian cellular hosts are described, for example, in Pouwels et al. Cloning Vectors: A Laboratory Manual, Elsevier, N.Y., (1985). Cell-free translation systems could also be employed to produce flt3-L polypeptides using RNAs derived from DNA constructs disclosed herein.
Prokaryotes include gram negative or gram positive organisms, for example, E. coli or Bacilli. Suitable prokaryotic host cells for transformation include, for example, E. coli, Bacillus subtilis, Salmonella typhimurium, and various other species within the genera Pseudomonas, Streptomyces, and Staphylococcus. In a prokaryotic host cell, such as E. coli, a flt3-L polypeptide may include an N-terminal methionine residue to facilitate expression of the recombinant polypeptide in the prokaryotic host cell. The N-terminal Met may be cleaved from the expressed recombinant flt3-L polypeptide.
Expression vectors for use in prokaryotic host cells generally comprise one or more phenotypic selectable marker genes. A phenotypic selectable marker gene is, for example, a gene encoding a protein that confers antibiotic resistance or that supplies an autotrophic requirement. Examples of useful expression vectors for prokaryotic host cells include those derived from commercially available plasmids such as the cloning vector pBR322 (ATCC 37017). pBR322 contains genes for ampicillin and tetracycline resistance and thus provides simple means for identifying transformed cells. To construct en expression vector using pBR322, an appropriate promoter and a flt3-L DNA sequence are inserted into the pBR322 vector. Other commercially available vectors include, for example, pKK223-3 (Pharmacia Fine Chemicals, Uppsala, Sweden) and pGEM 1 (Promega Biotec, Madison, Wis., USA).
Promoter sequences commonly used for recombinant prokaryotic host cell expression vectors include β-lactamase (penicillinase), lactose promoter system (Chang et al., Nature 275: 615, 1978; and Goeddel et al., Nature 281: 544, 1979), tryptophan (trp) promoter system (Goeddel et al., Nucl. Acids Res. 8: 4057, 1980; and EP-A-36776) and tac promoter (Maniatis, Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory, p. 412, 1982). A particularly useful prokaryotic host cell expression system employs a phage λ P L promoter and a cI857ts thermolabile repressor sequence. Plasmid vectors available from the American Type Culture Collection which incorporate derivatives of the λ P L promoter include plasmid pHUB2 (resident in E. coli strain JMB9 (ATCC 37092)) and pPLc28 (resident in E. coli RR1 (ATCC 53082)).
Flt3-L polypeptides alternatively may be expressed in yeast host cells, preferably from the Saccharomyces genus (e.g., S. cerevisiae). Other genera of yeast, such as Pichia, K. lactis or Kluyveromyces, may also be employed. Yeast vectors will often contain an origin of replication sequence from a 2μ yeast plasmid, an autonomously replicating sequence (ARS), a promoter region, sequences for polyadenylation, sequences for transcription termination, and a selectable marker gene. Suitable promoter sequences for yeast vectors include, among others, promoters for metallothionein, 3-phosphoglycerate kinase (Hitzeman et al., J. Biol. Chem. 255: 2073, 1980) or other glycolytic enzymes (Hess et al., J. Adv. Enzyme Reg. 7: 149, 1968; and Holland et al., Biochem. 17: 4900, 1978), such as enolase, glyceraldehyde-3-phosphate dehydrogenase, hexokinase, pyruvate decarboxylase, phosphofructokinase, glucose-6-phosphate isomerase, 3-phosphoglycerate mutase, pyruvate kinase, triosephosphate isomerase, phosphoglucose isomerase, and glucokinase. Other suitable vectors and promoters for use in yeast expression are further described in Hitzeman, EPA-73,657 or in Fleer et. al., Gene, 107: 285-195 (1991); and van den Berg et. al., Bio/Technology, 8: 135-139 (1990). Another alternative is the glucose-repressible ADH2 promoter described by Russell et al. (J. Biol. Chem. 258: 2674, 1982) and Beier et al. (Nature 300: 724, 1982). Shuttle vectors replicable in both yeast and E. coli may be constructed by inserting DNA sequences from pBR322 for selection and replication in E. coli (Amp r gene and origin of replication) into the above-described yeast vectors.
The yeast α-factor leader sequence may be employed to direct secretion of the flt3-L polypeptide. The α-factor leader sequence is often inserted between the promoter sequence and the structural gene sequence. See, e.g., Kurjan et al., Cell 30: 933, 1982; Bitter et al., Proc. Natl. Acad. Sci. USA 81: 5330, 1984; U.S. Pat. No. 4,546,082; and EP 324,274. Other leader sequences suitable for facilitating secretion of recombinant polypeptides from yeast hosts are known to those of skill in the art. A leader sequence may be modified near its 3' end to contain one or more restriction sites. This will facilitate fusion of the leader sequence to the structural gene.
Yeast transformation protocols are known to those of skill in the art. One such protocol is described by Hinnen et al., Proc. Natl. Acad. Sci. USA 75: 1929, 1978. The Hinnen et al. protocol selects for Trp + transformants in a selective medium, wherein the selective medium consists of 0.67% yeast nitrogen base, 0.5% casamino acids, 2% glucose, 10 μg/ml adenine and 20 μg/ml uracil.
Yeast host cells transformed by vectors containing ADH2 promoter sequence may be grown for inducing expression in a "rich" medium. An example of a rich medium is one consisting of 1% yeast extract, 2% peptone, and 1% glucose supplemented with 80 μg/ml adenine and 80 μg/ml uracil. Derepression of the ADH2 promoter occurs when glucose is exhausted from the medium.
Mammalian or insect host cell culture systems could also be employed to express recombinant flt3-L polypeptides. Baculovirus systems for production of heterologous proteins in insect cells are reviewed by Luckow and Summers, Bio/Technology 6: 47 (1988). Established cell lines of mammalian origin also may be employed. Examples of suitable mammalian host cell lines include the COS-7 line of monkey kidney cells (ATCC CRL 1651) (Gluzman et al., Cell 23: 175, 1981), L cells, C127 cells, 3T3 cells (ATCC CCL 163), Chinese hamster ovary (CHO) cells, HeLa cells, and BHK (ATCC CRL 10) cell lines, and the CV-1/EBNA-1 cell line derived from the African green monkey kidney cell line CVI (ATCC CCL 70) as described by McMahan et al. (EMBO J. 10: 2821, 1991).
Transcriptional and translational control sequences for mammalian host cell expression vectors may be excised from viral genomes. Commonly used promoter sequences and enhancer sequences are derived from Polyoma virus, Adenovirus 2, Simian Virus 40 (SV40), and human cytomegalovirus. DNA sequences derived from the SV40 viral genome, for example, SV40 origin, early and late promoter, enhancer, splice, and polyadenylation sites may be used to provide other genetic elements for expression of a structural gene sequence in a mammalian host cell. Viral early and late promoters are particularly useful because both are easily obtained from a viral genome as a fragment which may also contain a viral origin of replication (Fiers et al., Nature 273: 113, 1978). Smaller or larger SV40 fragments may also be used, provided the approximately 250 bp sequence extending from the Hind III site toward the Bgl I site located in the SV40 viral origin of replication site is included.
Exemplary expression vectors for use in mammalian host cells can be constructed as disclosed by Okayama and Berg (Mol. Cell. Biol. 3: 280, 1983). A useful system for stable high level expression of mammalian cDNAs in C127 murine mammary epithelial cells can be constructed substantially as described by Cosman et al. (Mol. Immunol. 23: 935, 1986). A useful high expression vector, PMLSV N1/N4, described by Cosman et al., Nature 312: 768, 1984 has been deposited as ATCC 39890. Additional useful mammalian expression vectors are described in EP-A-0367566, and in U.S. patent application Ser. No. 07/701,415, filed May 16, 1991, incorporated by reference herein. The vectors may be derived from retroviruses. In place of the native signal sequence, a heterologous signal sequence may be added, such as the signal sequence for IL-7 described in U.S. Pat. No. 4,965,195; the signal sequence for IL-2 receptor described in Cosman et al., Nature 312: 768 (1984); the IL-4 signal peptide described in EP 367,566; the type I IL-1 receptor signal peptide described in U.S. Pat. No. 4,968,607; and the type II IL-1 receptor signal peptide described in EP 460,846.
Flt3-L as an isolated or homogeneous protein according to the invention may be produced by recombinant expression systems as described above or purified from naturally occurring cells. Flt3-L can be purified to substantial homogeneity, as indicated by a single protein band upon analysis by SDS-polyacrylamide gel electrophoresis (SDS-PAGE).
One process for producing flt3-L comprises culturing a host cell transformed with an expression vector comprising a DNA sequence that encodes flt3-L under conditions sufficient to promote expression of flt3-L. Flt3-L is then recovered from culture medium or cell extracts, depending upon the expression system employed. As is known to the skilled artisan, procedures for purifying a recombinant protein will vary according to such factors as the type of host cells employed and whether or not the recombinant protein is secreted into the culture medium.
For example, when expression systems that secrete the recombinant protein are employed, the culture medium first may be concentrated using a commercially available protein concentration filter, for example, an Amicon or Millipore Pellicon ultrafiltration unit. Following the concentration step, the concentrate can be applied to a purification matrix such as a gel filtration medium. Alternatively, an anion exchange resin can be employed, for example, a matrix or substrate having pendant diethylaminoethyl (DEAE) groups. The matrices can be acrylamide, agarose, dextran, cellulose or other types commonly employed in protein purification. Alternatively, a cation exchange step can be employed. Suitable cation exchangers include various insoluble matrices comprising sulfopropyl or carboxymethyl groups. Sulfopropyl groups are preferred. Finally, one or more reversed-phase high performance liquid chromatography (RP-HPLC) steps employing hydrophobic RP-HPLC media, (e.g., silica gel having pendant methyl or other aliphatic groups) can be employed to further purify flt3-L. Some or all of the foregoing purification steps, in various combinations, are well known and can be employed to provide a substantially homogeneous recombinant protein.
It is possible to utilize an affinity column comprising the ligand binding domain of flt3 receptors to affinity-purify expressed flt3-L polypeptides. Flt3-L polypeptides can be removed from an affinity column using conventional techniques, e.g., in a high salt elution buffer and then dialyzed into a lower salt buffer for use or by changing pH or other components depending on the affinity matrix utilized. Alternatively, the affinity column may comprise an antibody that binds flt3-L. Example 6 describes a procedure for employing flt3-L of the invention to generate monoclonal antibodies directed against flt3-L.
Recombinant protein produced in bacterial culture is usually isolated by initial disruption of the host cells, centrifugation, extraction from cell pellets if an insoluble polypeptide, or from the supernatant fluid if a soluble polypeptide, followed by one or more concentration, salting-out, ion exchange, affinity purification or size exclusion chromatography steps. Finally, RP-HPLC can be employed for final purification steps. Microbial cells can be disrupted by any convenient method, including freeze-thaw cycling, sonication, mechanical disruption, or use of cell lysing agents.
Transformed yeast host cells are preferably employed to express flt3-L as a secreted polypeptide in order to simplify purification. Secreted recombinant polypeptide from a yeast host cell fermentation can be purified by methods analogous to those disclosed by Urdal et al. (J. Chromatog. 296: 171, 1984). Urdal et al. describe two sequential, reversed-phase HPLC steps for purification of recombinant human IL-2 on a preparative HPLC column.
Antisense or sense oligonucleotides comprising a single-stranded nucleic acid sequence (either RNA or DNA) capable of binding to a target flt3-L mRNA sequence (forming a duplex) or to the flt3-L sequence in the double-stranded DNA helix (forming a triple helix) can be made according to the invention. Antisense or sense oligonucleotides, according to the present invention, comprise a fragment of the coding region of flt3-L cDNA. Such a fragment generally comprises at least about 14 nucleotides, preferably from about 14 to about 30 nucleotides. The ability to create an antisense or a sense oligonucleotide, based upon a cDNA sequence for a given protein is described in, for example, Stein and Cohen, Cancer Res. 48: 2659, 1988 and van der Krol et al., BioTechniques 6: 958, 1988.
Binding of antisense or sense oligonucleotides to target nucleic acid sequences results in the formation of complexes that block translation (RNA) or transcription (DNA) by one of several means, including enhanced degradation of the duplexes, premature termination of transcription or translation, or by other means. The antisense oligonucleotides thus may be used to block expression of flt3-L proteins. Antisense or sense oligonucleotides further comprise oligonucleotides having modified sugar-phosphodiester backbones (or other sugar linkages, such as those described in WO91/06629) and wherein such sugar linkages are resistant to endogenous nucleases. Such oligonucleotides with resistant sugar linkages are stable in vivo (i.e., capable of resisting enzymatic degradation) but retain sequence specificity to be able to bind to target nucleotide sequences. Other examples of sense or antisense oligonucleotides include those oligonucleotides which are covalently linked to organic moieties, such as those described in WO 90/10448, and other moieties that increases affinity of the oligonucleotide for a target nucleic acid sequence, such as poly-(L-lysine). Further still, intercalating agents, such as ellipticine, and alkylating agents or metal complexes may be attached to sense or antisense oligonucleotides to modify binding specificities of the antisense or sense oliginucleotide for the target nucleotide sequence.
Antisense or sense oligonucleotides may be introduced into a cell containing the target nucleic acid sequence by any gene transfer method, including, for example, CaPO 4 -mediated DNA transfection, electroporation, or by using gene transfer vectors such as Epstein-Barr virus. Antisense or sense oligonucleotides are preferably introduced into a cell containing the target nucleic acid sequence by insertion of the antisense or sense oligonucleotide into a suitable retroviral vector, then contacting the cell with the retrovirus vector containing the inserted sequence, either in vivo or ex vivo. Suitable retroviral vectors include, but are not limited to, the murine retrovirus M-MuLV, N2 (a retrovirus derived from M-MuLV), or or the double copy vectors designated DCT5A, DCT5B and DCT5C (see PCT U.S. application Ser. No. 90/02,656).
Sense or antisense oligonucleotides also may be introduced into a cell containing the target nucleotide sequence by formation of a conjugate with a ligand binding molecule, as described in WO 91/04753. Suitable ligand binding molecules include, but are not limited to, cell surface receptors, growth factors, other cytokines, or other ligands that bind to cell surface receptors. Preferably, conjugation of the ligand binding molecule does not substantially interfere with the ability of the ligand binding molecule to bind to its corresponding molecule or receptor, or block entry of the sense or antisense oligonucleotide or its conjugated version into the cell.
Alternatively, a sense or an antisense oligonucleotide may be introduced into a cell containing the target nucleic acid sequence by formation of an oligonucleotide-lipid complex, as described in WO 90/10448. The sense or antisense oligonucleotide-lipid complex is preferably dissociated within the cell by an endogenous lipase.
Flt3-L polypeptides of the invention can be formulated according to known methods used to prepare pharmaceutically useful compositions. Flt3-L can be combined in admixture, either as the sole active material or with other known active materials, with pharmaceutically suitable diluents (e.g., Tris-HCl, acetate, phosphate), preservatives (e.g., Thimerosal, benzyl alcohol, parabens), emulsifiers, solubilizers, adjuvants and/or carriers. Suitable carriers and their formulations are described in Remington's Pharmaceutical Sciences, 16th ed. 1980, Mack Publishing Co. In addition, such compositions can contain flt3-L complexed with polyethylene glycol (PEG), metal ions, or incorporated into polymeric compounds such as polyacetic acid, polyglycolic acid, hydrogels, etc., or incorporated into liposomes, microemulsions, micelles, unilamellar or multilamellar vesicles, erythrocyte ghosts or spheroblasts. Such compositions will influence the physical state, solubility, stability, rate of in vivo release, and rate of in vivo clearance of flt3-L. Flt3-L can also be conjugated to antibodies against tissue-specific receptors, ligands or antigens, or coupled to ligands of tissue-specific receptors. Where the flt3 receptor is found on neoplastic cells, the flt3-L may be conjugated to a toxin whereby flt3-L is used to deliver the toxin to the specific site, or may be used to sensitize such neoplastic cells to subsequently administered anti-neoplastic agents.
Flt3-L can be administered topically, parenterally, or by inhalation. The term "parenteral" includes subcutaneous injections, intravenous, intramuscular, intracisternal injection, or infusion techniques. These compositions will typically contain an effective amount of the flt3-L, alone or in combination with an effective amount of any other active material. Such dosages and desired drug concentrations contained in the compositions may vary depending upon many factors, including the intended use, patient's body weight and age, and route of administration. Preliminary doses can be determined according to animal tests, and the scaling of dosages for human administration can be performed according to art-accepted practices. Keeping the above description in mind, typical dosages of flt3-L may range from about 10 μg per square meter to about 1000 μg per square meter. A preferred dose range is on the order of about 100 μg per square meter to about 300 μg per square meter.
In addition to the above, the following examples are provided to illustrate particular embodiments and not to limit the scope of the invention.
EXAMPLE 1
Preparation of Flt3-Receptor:Fc Fusion Protein
This example describes the cloning of murine flt3 cDNA, and the construction of an expression vector encoding a soluble murine flt3-receptor:Fc fusion protein for use in detecting cDNA clones encoding flt3-L. Polymerase chain reaction (PCR) cloning of the flt3 cDNA from a murine T-cell was accomplished using the oligonucleotide primers and the methods as described by Lyman et al., Oncogene, 8: 815-822, (1993), incorporated herein by reference. The cDNA sequence and encoded amino acid sequence for mouse flt3 receptor is presented by Rosnet et el., Oncogene, 6: 1641-1650, (1991), hereby incorporated by reference. The mouse flt3 protein has a 542 amino acid extracellular domain, a 21 amino acid transmembrane domain, and a 437 amino acid cytoplasmic domain.
Prior to fusing the murine flt3 cDNA to the N-terminus of cDNA encoding the Fc portion of a human IgG1 molecule, the amplified mouse flt3 cDNA fragment was inserted into Asp718-NotI site of pCAV/NOT, described in PCT Application WO 90/05183. DNA encoding a single chain polypeptide comprising the Fc region of a human IgG1 antibody was cloned into the SpeI site of the pBLUESCRIPT SK® vector, which is commercially available from Stratagene Cloning Systems, La Jolla, Calif. This plasmid vector is replicable in E. coli and contains a polylinker segment that includes 21 unique restriction sites. A unique BglII site was introduced near the 5' end of the inserted Fc encoding sequence, such that the BglII site encompasses the codons for amino acids three and four of the Fc polypeptide.
The encoded Fc polypeptide extends from the N-terminal hinge region to the native C-terminus, i.e., is an essentially full-length antibody Fc region. Fragments of Fc regions, e.g., those that are truncated at the C-terminal end, also may be employed. The fragments preferably contain multiple cysteine residues (at least the cysteine residues in the hinge reaction) to permit interchain disulfide bonds to form between the Fc polypeptide portions of two separate flt3:Fc fusion proteins, forming dimers as discussed above.
An Asp718 restriction endonuclease cleavage site was introduced upstream of the flt3 coding region. An Asp 718-NotI fragment of mouse flt3 cDNA (comprising the entire extracellular domain, the transmembrane region, and a small portion of the cytoplasmic domain) was isolated. The above-described Asp718-NotI flt3 partial cDNA was cloned into the pBLUESCRIPT SK® vector containing the Fc cDNA, such that the flt3 cDNA is positioned upstream of the Fc cDNA. Single stranded DNA derived from the resulting gene fusion was mutagenized by the method described in Kunkel (Proc. Natl. Acad. Sci. USA 82: 488, 1985) and Kunkel et al. (Methods in Enzymol. 154: 367, 1987) in order to perfectly fuse the entire extracellular domain of flt3 to the Fc sequence. The mutagenized DNA was sequenced to confirm that the proper nucleotides had been removed (i.e., transmembrane region and partial cytoplasmic domain DNA was deleted) and that the flt3 and Fc sequences were in the same reading frame. The fusion cDNA was then excised and inserted into a mammalian expression vector designated sfHAV-EO 409 which was cut with SalI-NotI, and the SalI and Asp718 ends blunted. The sfHAV-EO vector (also known as pDC406) is described by McMahan et al. (EMBO J., 10; No. 10: 2821-2832 (1991)).
Flt3:Fc fusion proteins preferably are synthesized in recombinant mammalian cell culture. The flt3:Fc fusion-containing expression vector was transfected into CV-1 cells (ATCC CCL 70) and COS-7 cells (ATCC CRL 1651), both derived from monkey kidney. Flt3:Fc expression level was relatively low in both CV-1 and COS-7 cells. Thus, expression in 293 cells (transformed primary human embryonal kidney cells, ATCC CRL 1573) was attempted.
The 293 cells transfected with the sfHAV-EO/flt3:Fc vector were cultivated in roller bottles to allow transient expression of the fusion protein, which is secreted into the culture medium via the flt3 signal peptide. The fusion protein was purified on protein A Sepharose columns, eluted, and used to screen cells for the ability to bind flt3:Fc, as described in Examples 2 and 3.
EXAMPLE 2
Screening Cells for Flt3:Fc Binding
Approximately 100 different primary cells and cell lines falling into the following general categories: primary murine fetal brain cells, murine fetal liver cell lines, rat fetal brain cell lines, human lung carcinoma (fibroblastoid) cell lines, human and murine lymphoid and myeloid cell lines were assayed for flt3:Fc binding. Cell lines were incubated with flt3:Fc, followed by a biotinylated anti-human Fc antibody, followed by streptavidin-phycoerythrin (Becton Dickinson). The biotinylated antibody was purchased from Jackson Immunoresearch Laboratories. Streptavidin binds to the biotin molecule attached to the anti-human Fc antibody, which in turn binds to the Fc portion of the flt3:Fc fusion protein. Phycoerythrin is a fluorescent phycobiliprotein which serves as a detectable label. The level of fluorescence signal was measured for each cell type using a FACScan® flow cytometer (Becton Dickinson). The cell types deemed positive for flt3:Fc binding were identified.
EXAMPLE 3
Isolation and Cloning of Flt3 L cDNA from Murine T-Cell cDNA Library
A murine T-cell cDNA library of cell line P7B-0.3A4 was chosen as a possible source of flt3-L cDNA. P7B-0.3A4 is a murine T cell clone that is Thy1.2 + , CD4 - , CD8 - , TCRab.sup.±, CD44 + . It was originally cloned at a cell density of 0.33 cells/well in the presence of rHuIL-7 and immobilized anti-CD3 MAb, and was grown in continuous culture for more than 1 year by passage once a week in medium containing 15 ng/ml rHuIL-7. The parent cell line was derived from lymph node cells of SJL/J mice immunized with 50 nmoles PLP 139-151 peptide and 100 μg Mycobacterium tuberculosis H37Ra in Incomplete Freund's Adjuvant. PLP is the proteolipid protein component of the myelin sheath of the central nervous system. The peptide composed of amino acids 139-151 has previously been shown to be the encephalogenic peptide in experimental autoimmune encephalomyelitis (EAE), a murine model for multiple sclerosis in SJL/J mice. (Touhy, V. K., Z. Lu, R. A. Sobel, R. A. Laursen and M. B. Lees; 1989. Identification of an encephalitogenic determinant of myelin proteolipid protein for SJL mice. J. Immunol. 142: 1523.) After the initial culture in the presence of antigen, the parent cell line, designated PLP7, had been in continuous culture with rHuIL-7 (and without antigen) for more than 6 months prior to cloning.
P7B-0.3A4 proliferates only in response to very high concentrations of PLP 139-151 peptide in the presence of irradiated syngeneic splenocytes and is not encephalogenic or alloresponsive. This clone proliferates in response to immobilized anti-CD3 MAb, IL-2, and IL-7, but not IL-4.
Binding of flt3:Fc was observed on murine T-cells and human T-cells, and therefore a murine T-cell line was chosen (0.3A4) due to its ease of growth. A murine 0.3A4 cDNA library in sfHAV-EO was prepared as described in McMahan et al. (EMBO J., 10; No: 10; 2821-2832 1991). sfHAV-EO is a mammalian expression vector that also replicates in E. coli. sfHAV-EO contains origins of replication derived from SV40, Epstein-Barr virus and pBR322 and is a derivative of HAV-EO described by Dower et al., J. Immunol. 142: 4314 (1989). sfHAV-EO differs from HAV-EO by the deletion of the intron present in the adenovirus 2 tripartite leader sequence in HAV-EO. Briefly, murine T-cell cDNA was cloned into the SalI site of sfHAV-EO by an adaptor method similar to that described by Haymerle et al (Nucl. Acids Res. 14: 8615, 1986), using the following oligonucleotide adapter pair:
______________________________________5' TCGACTGGAACGAGACGACCTGCT 3' SEQ ID NO:33' GACCTTGCTCTGCTGGACGA 5' SEQ ID NO:4______________________________________
Double-stranded, blunt-ended, random-primed cDNA was prepared from 0.3A4 poly (A)+ RNA essentially as described by Gubler and Hoffman, Gene, 25: 263-269 (1983), using a Pharmacia DNA kit. The above adapters were added to the cDNA as described by Haymerle et al.. Low molecular weight material was removed by passage over Sephacryl S-1000 at 65 -- C, and the cDNA was ligated into sfHAV-EO410, which had previously been cut with SalI and ligated to the same oligonucleotide pair. This vector is designated as sfHAV-EO410. DNA was electroporated (Dower et al., Nucleic Acids Res., 16: 6127-6145, (1988) into E. coli DH10B, and after one hour growth at 37 -- C, the transformed cells were frozen in one milliliter aliquots in SOC medium (Hanahan et al., J. Mol. Biol., 166: 557-580, (1983) containing 20% glycerol. One aliquot was titered to determine the number of ampcillin-resistant colonies. The resulting 0.3A4 library had 1.84 million clones.
E. coli strain DH10B cells transfected with the cDNA library in sfHAV-EO410 were plated to provide approximately 1600 colonies per plate. Colonies were scraped from each plate, pooled, and plasmid DNA prepared from each pool. The pooled DNA, representing about 1600 colonies, was then used to transfect a sub-confluent layer of CV-1/EBNA-1 cells using DEAE-dextran followed by chloroquine treatment, similar to that described by Luthman et al., Nucl. Acids Res. 11: 1295, (1983) and McCutchan et al., J. Natl. Cancer Inst. 41: 351, (1986). The CV-1/EBNA-1 cell line (ATCC CRL10478) constitutively expresses EBV nuclear antigen-1 driven from the CMV immediate-early enhancer/promoter. CV1-EBNA-1 was derived from the African Green Monkey kidney cell line CV-1 (ATCC CCL 70), as described by McMahan et al. (EMBO J. 10: 2821, 1991).
In order to transfect the CV-1/EBNA-1 cells with the cDNA library, the cells were maintained in complete medium (Dulbecco's modified Eagle's media (DMEM) containing 10% (v/v) fetal calf serum (FCS), 50 U/ml penicillin, 50 U/ml streptomycin, 2 mM L-glutamine) and were plated at a density of about 2×10 5 cells/well on single-well chambered slides (Lab-Tek). Slides were pretreated with 1 ml human fibronectin (10 μg/ml in PBS) for 30 minutes followed by 1 wash with PBS. Media was removed from the adherent cell layer and replaced with 1.5 ml complete medium containing 66.6 μM chloroquine sulfate. Two-tenths ml of DNA solution (2 μg DNA, 0.5 mg/ml DEAE-dextran in complete medium containing chloroquine) was then added to the cells and incubated for 5 hours. Following the incubation, the media was removed and the cells shocked by addition of complete medium containing 10% DMSO for 2.5 to 20 minutes followed by replacement of the solution with fresh complete medium. The cells were cultured for 2 to 3 days to permit transient expression of the inserted sequences.
Transfected monolayers of CV-1/EBNA-1 cells were assayed for expression of flt3-L by slide autoradiography essentially as described by Gearing et al. (EMBO J. 8: 3667, 1989). Transfected CV-1/EBNA-1 cells (adhered to chambered slides) were washed once with binding medium with nonfat dry milk (BM-NFDM) (RPMI medium 1640 containing 25 mg/ml bovine serum albumin (BSA), 2 mg/ml sodium azide, 20 mM HEPES, pH 7.2, and 50 mg/ml nonfat dry milk). Cells were then incubated with flt3:Fc in BM-NFDM (1 μg/ml) for 1 hour at room temperature. After incubation, the cell monolayers in the chambered slides were washed three times with BM-NFDM to remove unbound flt3:Fc fusion protein and then incubated with 40 ng/ml 125 I-mouse anti-human Fc antibody (described below) (a 1:50 dilution) for 1 hour at room temperature. The cells were washed three times with BM-NFDM, followed by 2 washes with phosphate-buffered saline (PBS) to remove unbound 125 I-mouse anti-human Fc antibody. The cells were fixed by incubating for 30 minutes at room temperature in 2.5% glutaraldehyde in PBS, pH 7.3, washed twice in PBS and air dried. The chamber slides containing the cells were exposed on a Phophorimager (Molecular Dynamics) overnight, then dipped in Kodak GTNB-2 photographic emulsion (6× dilution in water) and exposed in the dark for 3-5 days at 4 -- C in a light proof box. The slides were then developed for approximately 4 minutes in Kodak D19 developer (40 g/500 ml water), rinsed in water and fixed in Agfa G433C fixer. The slides were individually examined with a microscope at 25-40× magnification and positive cells expressing flt3-L were identified by the presence of autoradiographic silver grains against a light background.
The mouse anti-human Fc antibody was obtained from Jackson Laboratories. This antibody showed minimal binding to Fc proteins bound to the Fcγ receptor. The antibody was labeled using the Chloramine T method. Briefly, a Sephadex G-25 column was prepared according to the manufacturer's instructions. The column was pretreated with 10 column volumes of PBS containing 1% bovine serum albumin to reduce nonspecific adsorption of antibody to the column and resin. Nonbound bovine serum albumin was then washed from the column with 5 volumes of PBS lacking bovine serum albumin. In a microfuge tube 10 μg of antibody (dissolved in 10 μl of PBS) was added to 50 μl of 50 mM sodium phosphate buffer (pH 7.2) 2.0 mCi of carrier-free Na 125 I was added and the solution was mixed well. 15 μl of a freshly prepared solution of chloramine-T (2 mg/ml in 0.1M sodium phosphate buffer (pH 7.2)) was then added and the mixture was incubated for 30 minutes at room temperature, and the mixture then was immediately applied to the column of Sephadex G-25. The radiolabelled antibody was then eluted from the column by collecting 100-150 μl fractions of eluate. Bovine serum albumin was added to the eluted fractions containing the radiolabeled antibody to a final concentration of 1%. Radioiodination yielded specific activities in the range of 5-10×10 15 cpm/nmol protein.
Using the slide autoradiography approach, the approximately 1,840,000 cDNAs were screened in pools of approximately 1,600 cDNAs until assay of one transfectant pool showed multiple cells clearly positive for flt3:Fc binding. This pool was then partitioned into pools of 500 and again screened by slide autoradiography and a positive pool was identified. This pool was partitioned into pools of 100 and again screened. Individual colonies from this pool of 100 were screened until a clone (clone #6C) was identified which directed synthesis of a surface protein with detectable flt3:Fc binding activity. This clone was isolated, and its 0.88 kb cDNA insert was sequenced.
The nucleotide and encoded amino acid sequences of the coding region of the murine flt3-ligand cDNA of clone #6C are presented in SEQ ID NOs:1 and 2. The cDNA insert is 0.88 kb in length. The open-reading frame within this sequence could encode a protein of 231 amino acids. Thus, DNA and encoded amino acid sequences for the 231-amino acid open reading frame are presented in SEQ ID NOs:1 and 2.
The protein of SEQ ID NO:2 is a type I transmembrane protein, with an N-terminal signal peptide (amino acids 1 to 27), an extracellular domain (amino acids 28-188) a transmembrane domain (amino acids 189-211) and a cytoplasmic domain (amino acids 212-231). The predicted molecular weight of the native protein following cleavage of the signal sequence is 23,164 daltons. The mature protein has an estimated pI of 9.372. There are 56 bp of 5' noncoding sequence and 126 bp of 3' non-coding sequence flanking the coding region, including the added cDNA adapters. The above-described cloning procedure also produced a murine flt3 ligand clone #5H, which is identical to the #6C clone beginning at nucleotide 49 and continuing through nucleotide 545 (corresponding to amino acid 163) of SEQ ID NO:1. The #5H clone completely differs from that point onward, and represents an alternate splicing construct.
The vector sfHAV-EO410 containing the flt3-L cDNA in E. coli DH10B cells was deposited with the American Type Culture Collection, Rockville, Md., USA (ATCC) on Apr. 20, 1993 and assigned accession number ATCC 69286. The deposit was made under the terms of the Budapest Treaty.
EXAMPLE 4
Cloning of cDNA Encoding Human Flt3-L
A cDNA encoding human flt3-L was cloned from a human clone 22 T cell λgt10 random primed cDNA library as described by Sims et al., PNAS, 86: 8946-8950 (1989). The library was screened with a 413 bp Ple I fragment corresponding to the extracellular domain of the murine flt3-L (nucleotides 103-516 of SEQ ID NO:1). The fragment was random primed, hybridized overnight to the library filters at 55 -- C in oligo prehybridization buffer. The fragment was then washed at 55 -- C at 2× SSC/0.1% SDS for one hour, followed by 1× SSC/0.1% SDS for one hour and then by 0.5× SSC/0,1% SDS for one hour. The DNA from the positive phage plaques was extracted, and the inserts were amplified by PCR using oligonucleotides specific for the phage arms. The DNA then was sequenced, and the sequence for clone #9 is shown in SEQ ID NO:5. Additional human flt3-L cDNA was isolated from the same λgt10 random primed cDNA library as described above by screening the library with a fragment of the extracellular domain of the murine clone #5H cDNA comprising a cDNA sequence essentially corresponding to nucleotides 128-541 of SEQ ID NO:1.
Sequencing of the 988 bp cDNA clone #9 revealed an open reading frame of 705 bp surrounded by 29 bp of 5' non-coding sequence and 250 bp of 3' non-coding sequence. The 3' non-coding region did not contain a poly-A tail. There were no in-frame stop codons upstream of the initiator methionine. The open reading frame encodes a type I transmembrane protein of 235 amino acids as shown by amino acids 1-235 of SEQ ID NO:6. The protein has an N-terminal signal peptide of alternatively 26 or 27 amino acids. There exists a slightly greater probability that the N-terminal signal peptide is 26 amino acids in length than 27 amino acids in length. The signal peptide is followed by a 156 or a 155 amino acid extracellular domain (for signal peptides of 26 and 27 amino acids, respectively); a 23 amino acid transmembrane domain and a 30 amino acid cytoplasmic domain. Human flt3-L shares overall 72% amino acid identity and 78% amino acid similarity with murine flt3-L. The vector pBLUESCRIPT SK(-) containing the human flt3-L cDNA of clone #9 was deposited with the American Type Culture Collection, Rockville, Md., USA (ATCC) on Aug. 6, 1993 and assigned acession number ATCC 69382. The deposit was made under the terms of the Budapest Treaty.
EXAMPLE 5
Expression of Flt3-L in Yeast
For expression of soluble flt3-L in yeast, synthetic oligonucleotide primers were used to amplify via PCR (Mullis and Faloona, Meth. Enzymol. 155: 335-350, 1987) the entire extracellular coding domain of flt3-L between the end of the signal peptide and the start of the transmembrane segment. The 5' primer (5'-AATTGGTACCTTTGGATAAAAGAGACTACAAGGACGACGATGACAAGACACCTGACTGTTACTTCAGCCAC-3') SEQ ID NO:7 encoded a portion of of the alpha factor leader and an antigenic octapeptide, the FLAG sequence fused in-frame with the predicted mature N-terminus of flt3-L. The 3' oligonucleotide (5'-ATATGGATCCCTACTGCCTGGGCCGAGGCTCTGGGAG-3') SEQ ID NO:8 created a termination codon following Gln-189, just at the putative transmembrane region. The PCR-generated DNA fragment was ligated into a yeast expression vector (for expression in K. lactis) that directs secretion of the recombinant product into the yeast medium (Fleer et. al., Gene, 107: 285-195 (1991); and van den Berg et. al., Bio/Technology, 8: 135-139 (1990)). The FLAG:flt3-L fusion protein was purified from yeast broth by affinity chromatography as previously described (Hopp et. al., Biotechnology, 6: 1204-1210, 1988).
EXAMPLE 6
Monoclonal Antibodies to Flt3-L
This example illustrates a method for preparing monoclonal antibodies to flt3-L. Flt3-L is expressed in mammalian host cells such as COS-7 or CV-1/EBNA-1 cells and purified using flt3:Fc affinity chromatography. Purified flt3-L, a fragment thereof such as the extracellular domain, synthetic peptides or cells that express flt3-L can be used to generate monoclonal antibodies against flt3-L using conventional techniques, for example, those techniques described in U.S. Pat. No. 4,411,993. Briefly, mice are immunized with flt3-L as an immunogen emulsified in complete Freund's adjuvant, and injected in amounts ranging from 10-100 μg subcutaneously or intraperitoneally. Ten to twelve days later, the immunized animals are boosted with additional flt3-L emulsified in incomplete Freund's adjuvant. Mice are periodically boosted thereafter on a weekly to bi-weekly immunization schedule. Serum samples are periodically taken by retro-orbital bleeding or tail-tip excision to test for flt3-L antibodies by dot blot assay, ELISA (Enzyme-Linked Immunosorbent Assay) or inhibition of flt3 binding.
Following detection of an appropriate antibody titer, positive animals are provided one last intravenous injection of flt3-L in saline. Three to four days later, the animals are sacrificed, spleen cells harvested, and spleen cells are fused to a murine myeloma cell line, e.g., NS1 or preferably P3x63Ag8.653 (ATCC CRL 1580). Fusions generate hybridoma cells, which are plated in multiple microtiter plates in a HAT (hypoxanthine, aminopterin and thymidine) selective medium to inhibit proliferation of non-fused cells, myeloma hybrids, and spleen cell hybrids.
The hybridoma cells are screened by ELISA for reactivity against purified flt3-L by adaptations of the techniques disclosed in Engvall et al., Immunochem. 8: 871, 1971 and in U.S. Pat. No. 4,703,004. A preferred screening technique is the antibody capture technique described in Beckmann et al., (J. Immunol. 144: 4212, 1990) Positive hybridoma cells can be injected intraperitoneally into syngeneic BALB/c mice to produce ascites containing high concentrations of anti-flt3-L-L monoclonal antibodies. Alternatively, hybridoma cells can be grown in vitro in flasks or roller bottles by various techniques. Monoclonal antibodies produced in mouse ascites can be purified by ammonium sulfate precipitation, followed by gel exclusion chromatography. Alternatively, affinity chromatography based upon binding of antibody to protein A or protein G can also be used, as can affinity chromatography based upon binding to flt3-L.
EXAMPLE 7
Use of Flt3-L Alone and in Combination with IL-7 or IL-3
This example demonstrates the stimulation and proliferation of AA4.1 + fetal liver cells by compositions containing flt3-L and IL-7; as well as the stimulation and proliferation of c-kit-positive (c-kit + ) cells by compositions containing flt3-L and IL-3.
AA4.1-positive (AA4.1 + ) expressing cells were isolated from the livers of day 14 fetal C57BL/6 mice by cell panning in Optilux 100 mm plastic Petri dishes (Falcon No. 1001, Oxnard, Calif.). Plates were coated overnight at 4 -- C in PBS plus 0.1% fetal bovine serum (FBS) containing 10 μg/ml AA4.1 antibody (McKearn et. al., J. Immunol., 132: 332-339, 1984) and then washed extensively with PBS plus 1% FBS prior to use. A single cell suspension of liver cells was added at 10 7 cells/dish in PBS plus 1% FBS and allowed to adhere to the plates for two hours at 4 -- C. The plates were then extensively washed, and the adhering cells were harvested by scraping for analysis or further use in the hematopoiesis assays described below. FACS analysis using AA4.1 antibody demonstrated a >95% AA4.1 + cell population.
C-kit + pluripotent stem cells were purified from adult mouse bone marrow (de Vries et. al., J. Exp. Med., 176: 1503-1509, 1992; and Visser and de Vries, Methods in Cell Biol., 1993, submitted). Low density cells ( 2 1.078 g/cm 3 ) positive for the lectin wheat germ agglutinin and negative for the antigens recognized by the B220 and 15-1.4.1 (Visser et. al., Meth. in Cell Biol., 33: 451-468, 1990) monoclonal antibodies, could be divided into sub-populations of cells that do and do not express c-kit by using biotinylated Steel factor. The c-kit + fraction has been shown to contain pluripotent hematopoietic stem cells (de Vries et. al., Science 255: 989-991, 1992; Visser and de Vries, Methods in Cell Biol., 1993, submitted; and Ware et. al., 1993, submitted).
AA4.1+ Fetal liver cells were cultured in recombinant IL-7 (U.S. Pat. No. 4,965,195) at 100 ng/ml and recombinant flt3-L at 250 ng/ml. Flt3-L was used in three different forms in the experiments: (1) as present on fixed, flt3-L-transfected CV1/EBNA cells; (2) as concentrated culture supernatants from these same flt3-L-transfected CV1/EBNA cells; and (3) as a purified and isolated polypeptide preparation from yeast supernatant as described in Example 5.
Hematopoiesis Assays
The proliferation of c-kit + stem cells, fetal liver AA4.1 + cells was assayed in 3H!-thymidine incorporation assays as essentially described by deVries et. al., J. Exp. Med., 173: 1205-1211, 1991. Purified c-kit + stem cells were cultured at 37 -- C in a fully humidified atmosphere of 6.5% CO 2 and 7% O 2 in air for 96 hours. Murine recombinant IL-3 was used at a final concentration of 100 ng/ml. Subsequently, the cells were pulsed with 2 μCi per well of 3 H!-thymidine (81 Ci/mmol; Amersham Corp., Arlington Heights, Ill.) and incubated for an additional 24 hours. AA4.1 + cells (approximately 20,000 cells/well) were incubated in IL-7, flt3-L and flt3-L+IL-7 for 48 hours, followed by 3 H!-thymidine pulse of six hours. The results of flt3-L and IL-7 are shown in Table I, and results of flt3-L and IL-3 are shown in Table II.
TABLE I______________________________________Effect of Flt3-L and IL-7 on Proliferation of AA4.1 + Fetal LiverCells. Factor Control flt3-L IL-7 flt3-L + IL-7______________________________________ .sup.3 H!-thymidine 100 1000 100 4200incorporation(CPM)______________________________________
The combination of flt3-L and IL-7 produced a response that was approximately four-fold greater than flt3-L alone and approximately 40-fold greater than IL-7 alone.
TABLE II______________________________________Effect of Flt3-L and IL-3 on Proliferation of C-kit + Cells. Factor Control (vector alone) flt3-L IL-3 flt3-L + IL-3______________________________________ .sup.3 H!-thymidine 100 1800 3000 9100incorporation(CPM)______________________________________
Culture supernatant from CV1/EBNA cells transfected with flt3-L cDNA stimulated the proliferation of c-kit + stem cells approximately 18-fold greater than the culture supernatant of CV1/EBNA cells transfected with the expression vector alone. Addition of IL-3 to flt3-L containing supernatant showed a synergistic effect, with approximately twice the degree of proliferation observed than would be expected if the effects were additive.
EXAMPLE 8
Construction of Flt3-L:Fc Fusion Protein
This example describes a method for constructing a fusion protein comprising an extracellular region of the flt3-L and the Fc domain of a human immunoglobulin. The methods are essentially the same as those described in Example 1 for construction of a flt3:Fc fusion protein.
Prior to fusing a flt3-L cDNA to the N-terminus of cDNA encoding the Fc portion of a human IgG1 molecule, the flt3-L cDNA fragment is inserted into Asp718-NotI site of pCAV/NOT, described in PCT Application WO 90/05183. DNA encoding a single chain polypeptide comprising the Fc region of a human IgG1 antibody is cloned into the SpeI site of the pBLUESCRIPT SK® vector, which is commercially available from Stratagene Cloning Systems, La Jolla, Calif. This plasmid vector is replicable in E. coli and contains a polylinker segment that includes 21 unique restriction sites. A unique BglII site is then introduced near the 5' end of the inserted Fc encoding sequence, such that the BglII site encompasses the codons for amino acids three and four of the Fc polypeptide.
The encoded Fc polypeptide extends from the N-terminal hinge region to the native C-terminus, i.e., is an essentially full-length antibody Fc region. Fragments of Fc regions, e.g., those that are truncated at the C-terminal end, also may be employed. The fragments preferably contain multiple cysteine residues (at least the cysteine residues in the hinge reaction) to permit interchain disulfide bonds to form between the Fc polypeptide portions of two separate flt3-L:Fc fusion proteins, forming dimers.
An Asp718-StuI partial cDNA of flt3-L in pCAV/NOT can be cloned into a Asp718-SpeI site of pBLUESCRIPT SK® vector containing the Fc cDNA, such that the flt3-L cDNA is positioned upstream of the Fc cDNA. The sequence of single stranded DNA derived from the resulting gene fusion can be affected by template-directed mutagensis described by Kunkel (Proc. Natl. Acad. Sci. USA 82: 488, 1985) and Kunkel et al. (Methods in Enzymol. 154: 367, 1987) in order to perfectly fuse the entire extracellular domain of flt3-L to the Fc sequence. The resulting DNA can then be sequenced to confirm that the proper nucleotides are removed (i.e., transmembrane region and partial cytoplasmic domain DNA are deleted) and that flt3-L and Fc sequences are in the same reading frame. The fusion cDNA is then excised and inserted using conventional methods into the mammalian expression vector pCAV/NOT which is cut with Asp 718-NotI.
Flt3-L:Fc fusion proteins preferably are synthesized in recombinant mammalian cell culture. The flt3-L:Fc fusion-containing expression vector is then transfected into CV-1 cells (ATCC CCL 70) or COS-7 cells (ATCC CRL 1651). Expression in 293 cells (transformed primary human embryonal kidney cells, ATCC CRL 1573) also is feasible.
The 293 cells transfected with the pCAV/NOT/flt3-L:Fc vector are cultivated in roller bottles to allow transient expression of the fusion protein, which is secreted into the culture medium via the flt3-L signal peptide. The fusion protein can be purified on protein A Sepharose columns.
EXAMPLE 9
Generation of Transgenic Mice That Overexpress Flt3-L
This example describes a procedure used to generate transgenic mice that overexpress flt3-L. Flt3-L-overexpressing transgenic mice were studied to determine the biological effects of overexpression. Mouse (B 16/J) pronuclei were microinjected with flt3-L DNA according to the method described by Gordon et al., Science 214: 1244-1246, (1981). In general, fertilized mouse eggs having visible pronuclei were first placed on an injection chamber and held in place with a small pipet. An injection pipet was then used to inject the gene encoding the flt3-L (clone #6C) into the pronuclei of the egg. Injected eggs were then either (i) transferred into the oviduct of a 0.5 day p.c. pseudopregnant female; (ii) cultured in vitro to the two-cell stage (overnight) and transferred into the oviduct of a 0.5 day p.c. pseudopregnant female; or (iii) cultured in vitro to the blastocyst stage and transferred into the uterus of a 2.5 day p.c. pseudopregnant female. Preferably, either of the first two options can be used since they avoid extended in vitro culture, and preferably, approximately 20-30 microinjected eggs should be transferred to avoid small litters.
EXAMPLE 10
Flt3-L Stimulates Proliferation of Erythroid Cells in the Spleen
This example describes the effect of flt3-L on the production of erythroid cells in the spleen of transgenic mice. Transgenic mice were generated according to the procedures of Example 10. The mice were sacrificed and each intact spleen was made into a single cell suspension. The suspended cells were spun and then resuspended in 10 ml of medium that contained PBS+1% fetal bovine serum. Cell counts were performed thereon using a hemocytometer. Each cell specimen was counted with Trypan Blue stain to obtain a total viable cell count per milliliter of medium according to the following formula: (RBC+WBC)/ml, wherein RBC is the red blood cell count and WBC means the white blood cell count. Each specimen then was counted with Turk's stain to obtain a total white blood cell count per milliliter of medium. The total red blood cell count per milliliter was calculated for each specimen by subtracting the total white blood cell count per milliliter from the total viable cell count per milliliter. The results are shown in the following Table III.
TABLE III______________________________________Erythroid Cell Proliferation in Flt3-L-Overexpressing Transgenic MiceSpleen Total Total Viable Cell Total White Cell Red Blood CellMouse (million cells/ml) (million cells/ml) (million cells/ml)______________________________________Control 1 29.7 27 2.7Control 2 31 24.6 6.4Transgenic 1 44.7 25.6 19.1Transgenic 2 37.3 28.4 8.9______________________________________
From the data of Table III, the white blood cell counts per milliliter were approximately the same as the control mice. However, the red blood cell counts from the spleens of the two transgenic mice were approximately two to three-fold greater than observed in the control mice. Flt3-L stimulates an increase in cells of the erythroid lineage, possibly through stimulation of erythroid proogenitor cells, through the stimulation of cells that produce erythropoietin, or by blocking a mechanism that inhibits erythropoiesis.
EXAMPLE 11
Flt3-L Stimulates Proliferation of T Cells and Early B Cells
Bone marrow from 9 week old transgenic mice generated according to Example 10 was screened for the presence of various T and B cell phenotype markers using antibodies that are immunoreactive with such markers. The following markers were investigated: the B220 marker, which is specific to the B cell lineage; surface IgM marker (sIgM), which is specific to mature B cells; the S7 (CD43) marker, which is an early B cell marker; the Stem Cell Antigen-1 (SCA-1) marker, which is a marker of activated T cells and B cells; CD4, which is a marker for helper T cells and some stem cells; and the Mac-1 marker, which is specific to macrophages, were screened using well known antibodies against such markers. The following Table IV shows the data obtained from screening the bone marrow. Two transgenic mice from the same litter were analyzed against a normal mouse from the same litter (control), and an unrelated normal mouse (control).
TABLE IV______________________________________Effect of flt3-L Overexpression in Transgenic Mice Percentage of Positive Cells Unrelated LittermateMarker Control Control Transgenic #1 Transgenic #2______________________________________B220 30.64 27.17 45.84 48.78sIgM 3.54 2.41 1.94 1.14S7 (CD43) 54.43 45.44 46.11 50.59SCA-1 10.92 11.74 19.45 27.37CD4 6.94 8.72 12.21 14.05Mac-1 36.80 27.15 21.39 18.63______________________________________
The above data indicate that flt3-L overexpression in mice leads to an increase in the number of B cells, as indicated by the increase B220 + cells and SCA-1 + cells. Analysis of B220 + cells by FACS indicated an increase in proB cells (HSA - , S7 + ). The increase in CD4 + cells indicated an approximate two-fold increase in T cells and stem cells. The decrease in cells having the sIgM marker indicated that flt3-L does not stimulate proliferation of mature B cells. These data indicate that flt3-L increases cells with a stem cell, T cell or an early B cell phenotype, and does not stimulate proliferation of mature B cells or macrophages.
EXAMPLE 12
Analysis of the Thymus From Flt3-L-Over-expressing Mice
This Example describes the analysis of the thymus from the transgenic mice generated according to the procedure of Example 10. Six adult mice, each approximately three months of age, were sacrificed. The thymus from each mouse was removed and a single cell suspension was made.
FACS analysis demonstrated that no total change in cell number occurred and that the mice showed no change in the ratios of maturing thymocytes using the markers: CD4 vs. CD8; CD3 vs. αβTCR (T cell receptor); and CD3 vs. γδTCR (T cell receptor). However, a change in the ratios of certain cell types within the CD4 - and CD8 - compartment (i.e., the earliest cells with respect to development; which represent approximately 2% to 3% of total thymus cells) occurred. Specifically, CD4 - and CD8 - cells in the thymus develop in three stages. Stage 1 represents cells having the Pgp-1 ++ , HSA + and IL-2 receptor-negative ("IL-2R-") markers. After stage 1, thymic cells develop to stage 2 consisting of cells having Pgp-1 + , HSA ++ , and IL-2R ++ markers, and then to stage 3, characterized by cells having Pgp-1.sup.±, HSA ++ , and IL-2R - markers. Thymic cells in stage 2 of the transgenic mice were reduced by about 50%, while the population of cells in stage 3 was proportionately increased. These data suggest that flt3-L drives the thymic cells from stage 2 to stage 3 of development, indicating that flt3-L is active on early T cells.
EXAMPLE 13
Use of Flt3-L in Peripheral Stem Cell Transplantation
This Example describes a method for using flt3-L in autologous peripheral stem cell (PSC) or peripheral blood progenitor cell (PBPC) transplantation. Typically, PBPC and PSC transplantation is performed on patients whose bone marrow is unsuitable for collection due to, for example, marrow abnormality or malignant involvement.
Prior to cell collection, it may be desirable to mobilize or increase the numbers of circulating PBPC and PSC. Mobilization can improve PBPC and PSC collection, and is achievable through the intravenous administration of flt3-L to the patients prior to collection of such cells. Other growth factors such as CSF-1, GM-CSF, SF, G-CSF, EPO, IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-11, IL-12, IL-13, IL-14, IL-15, GM-CSF/IL-3 fusion proteins, LIF, FGF and combinations thereof, can be likewise administered in sequence, or in concurrent combination with flt3-L. Mobilized or non-mobilized PBPC and PSC are collected using apheresis procedures known in the art. See, for example, Bishop et al., Blood, vol. 83, No. 2, pp. 610-616 (1994). Briefly, PBPC and PSC are collected using conventional devices, for example, a Haemonetics Model V50 apheresis device (Haemonetics, Braintree, Mass.). Four-hour collections are performed typically no more than five times weekly until approximately 6.5×10 8 mononuclear cells (MNC)/kg patient are collected. Aliquots of collected PBPC and PSC are assayed for granulocyte-macrophage colony-forming unit (CFU-GM) content by diluting approximately 1:6 with Hank's balanced salt solution without calcium or magnesium (HBSS) and layering over lymphocyte separation medium (Organon Teknika, Durham, N.C.). Following centrifugation, MNC at the interface are collected, washed and resuspended in HBSS. One milliliter aliquots containing approximately 300,000 MNC, modified McCoy's 5A medium, 0.3% agar, 200 U/mL recombinant human GM-CSF, 200 u/mL recombinant human IL-3, and 200 u/mL recombinant human G-CSF are cultured at 37 -- C in 5% CO 2 in fully humidified air for 14 days. Optionally, flt3-L or GM-CSF/IL-3 fusion molecules (PIXY 321) may be added to the cultures. These cultures are stained with Wright's stain, and CFU-GM colonies are scored using a dissecting microscope (Ward et al., Exp. Hematol., 16: 358 (1988). Alternatively, CFU-GM colonies can be assayed using the CD34/CD33 flow cytometry method of Siena et al., Blood, Vol. 77, No. 2, pp 400-409 (1991), or any other method known in the art.
CFU-GM containing cultures are frozen in a controlled rate freezer (e.g., Cryo-Med, Mt. Clemens, Mich.), then stored in the vapor phase of liquid nitrogen. Ten percent dimethylsulfoxide can be used as a cryoprotectant. After all collections from the patient have been made, CFU-GM containing cultures are thawed and pooled. The thawed cell collection either is reinfused intravenoulsy to the patient or expanded ex vivo prior to reinfusion. Ex vivo expansion of pooled cells can be performed using flt3-L as a growth factor either alone, sequentially or in concurrent combination with other cytokines listed above. Methods of such ex vivo expansion are well known in the art. The cells, either expanded or unexpanded, are reinfused intravenously to the patient. To facilitate engraftment of the transplanted cells, flt3-L is administered simultaneously with, or subsequent to, the reinfusion. Such administration of flt3-L is made alone, sequentially or in concurrent combination with other cytokines selected from the list above.
EXAMPLE 14
Purification of Hematopoietic Progenitor and Stem Cells Using Flt3-L
This Example describes a method for purifying hematopoietic progenitor cells and stem cells from a suspension containing a mixture of cells. Cells from bone marrow and peripheral blood are collected using conventional procedures. The cells are suspended in standard media and then centrifuged to remove red blood cells and neutrophils. Cells located at the interface between the two phases (also known in the art as the buffy coat) are withdrawn and resuspended. These cells are predominantly mononuclear and represent a substantial portion of the early hematopoietic progenitor and stem cells. The resulting cell suspension then is incubated with biotinylated flt3-L for a sufficient time to allow substantial flt3:flt3-L interaction. Typically, incubation times of at least one hour are sufficient. After incubation, the cell suspension is passed, under the force of gravity, through a column packed with avidin-coated beads. Such columns are well known in the art, see Berenson, et al., J. Cell Biochem., 10D: 239 (1986). The column is washed with a PBS solution to remove unbound material. Target cells can be released from the beads and from flt3-L using conventional methods.
__________________________________________________________________________SEQUENCE LISTING(1) GENERAL INFORMATION:(iii) NUMBER OF SEQUENCES: 8(2) INFORMATION FOR SEQ ID NO:1:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 879 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA to mRNA(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(ix) FEATURE:(A) NAME/KEY: misc.sub.-- feature(B) LOCATION: 1..25(ix) FEATURE:(A) NAME/KEY: misc.sub.-- feature(B) LOCATION: 855..879(ix) FEATURE:(A) NAME/KEY: CDS(B) LOCATION: 57..752(xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:GTCGACTGGAACGAGACGACCTGCTCTGTCACAGGCATGAGGGGTCCCCGGCAGAG56ATGACAGTGCTGGCGCCAGCCTGGAGCCCAAATTCCTCCCTGTTGCTG104MetThrValLeuAlaProAlaTrpSerProAsnSerSerLeuLeuLeu151015CTGTTGCTGCTGCTGAGTCCTTGCCTGCGGGGGACACCTGACTGTTAC152LeuLeuLeuLeuLeuSerProCysLeuArgGlyThrProAspCysTyr202530TTCAGCCACAGTCCCATCTCCTCCAACTTCAAAGTGAAGTTTAGAGAG200PheSerHisSerProIleSerSerAsnPheLysValLysPheArgGlu354045TTGACTGACCACCTGCTTAAAGATTACCCAGTCACTGTGGCCGTCAAT248LeuThrAspHisLeuLeuLysAspTyrProValThrValAlaValAsn505560CTTCAGGACGAGAAGCACTGCAAGGCCTTGTGGAGCCTCTTCCTAGCC296LeuGlnAspGluLysHisCysLysAlaLeuTrpSerLeuPheLeuAla65707580CAGCGCTGGATAGAGCAACTGAAGACTGTGGCAGGGTCTAAGATGCAA344GlnArgTrpIleGluGlnLeuLysThrValAlaGlySerLysMetGln859095ACGCTTCTGGAGGACGTCAACACCGAGATACATTTTGTCACCTCATGT392ThrLeuLeuGluAspValAsnThrGluIleHisPheValThrSerCys100105110ACCTTCCAGCCCCTACCAGAATGTCTGCGATTCGTCCAGACCAACATC440ThrPheGlnProLeuProGluCysLeuArgPheValGlnThrAsnIle115120125TCCCACCTCCTGAAGGACACCTGCACACAGCTGCTTGCTCTGAAGCCC488SerHisLeuLeuLysAspThrCysThrGlnLeuLeuAlaLeuLysPro130135140TGTATCGGGAAGGCCTGCCAGAATTTCTCTCGGTGCCTGGAGGTGCAG536CysIleGlyLysAlaCysGlnAsnPheSerArgCysLeuGluValGln145150155160TGCCAGCCGGACTCCTCCACCCTGCTGCCCCCAAGGAGTCCCATAGCC584CysGlnProAspSerSerThrLeuLeuProProArgSerProIleAla165170175CTAGAAGCCACGGAGCTCCCAGAGCCTCGGCCCAGGCAGCTGTTGCTC632LeuGluAlaThrGluLeuProGluProArgProArgGlnLeuLeuLeu180185190CTGCTGCTGCTGCTGCCTCTCACACTGGTGCTGCTGGCAGCCGCCTGG680LeuLeuLeuLeuLeuProLeuThrLeuValLeuLeuAlaAlaAlaTrp195200205GGCCTTCGCTGGCAAAGGGCAAGAAGGAGGGGGGAGCTCCACCCTGGG728GlyLeuArgTrpGlnArgAlaArgArgArgGlyGluLeuHisProGly210215220GTGCCCCTCCCCTCCCATCCCTAGGATTCGAGCCTTGTGCATCGTTGACTC779ValProLeuProSerHisPro225230AGCCAGGGTCTTATCTCGGTTACACCTGTAATCTCAGCCCTTGGGAGCCCAGAGCAGGAT839TGCTGAATGGTCTGGAGCAGGTCGTCTCGTTCCAGTCGAC879(2) INFORMATION FOR SEQ ID NO:2:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 231 amino acids(B) TYPE: amino acid(D) TOPOLOGY: linear(ii) MOLECULE TYPE: protein(xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:MetThrValLeuAlaProAlaTrpSerProAsnSerSerLeuLeuLeu151015LeuLeuLeuLeuLeuSerProCysLeuArgGlyThrProAspCysTyr202530PheSerHisSerProIleSerSerAsnPheLysValLysPheArgGlu354045LeuThrAspHisLeuLeuLysAspTyrProValThrValAlaValAsn505560LeuGlnAspGluLysHisCysLysAlaLeuTrpSerLeuPheLeuAla65707580GlnArgTrpIleGluGlnLeuLysThrValAlaGlySerLysMetGln859095ThrLeuLeuGluAspValAsnThrGluIleHisPheValThrSerCys100105110ThrPheGlnProLeuProGluCysLeuArgPheValGlnThrAsnIle115120125SerHisLeuLeuLysAspThrCysThrGlnLeuLeuAlaLeuLysPro130135140CysIleGlyLysAlaCysGlnAsnPheSerArgCysLeuGluValGln145150155160CysGlnProAspSerSerThrLeuLeuProProArgSerProIleAla165170175LeuGluAlaThrGluLeuProGluProArgProArgGlnLeuLeuLeu180185190LeuLeuLeuLeuLeuProLeuThrLeuValLeuLeuAlaAlaAlaTrp195200205GlyLeuArgTrpGlnArgAlaArgArgArgGlyGluLeuHisProGly210215220ValProLeuProSerHisPro225230(2) INFORMATION FOR SEQ ID NO:3:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 24 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:TCGACTGGAACGAGACGACCTGCT24(2) INFORMATION FOR SEQ ID NO:4:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 20 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(xi) SEQUENCE DESCRIPTION: SEQ ID NO:4:AGCAGGTCGTCTCGTTCCAG20(2) INFORMATION FOR SEQ ID NO:5:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 988 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA to mRNA(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(ix) FEATURE:(A) NAME/KEY: CDS(B) LOCATION: 30..734(xi) SEQUENCE DESCRIPTION: SEQ ID NO:5:CGGCCGGAATTCCGGGGCCCCCGGCCGAAATGACAGTGCTGGCGCCAGCCTGG53MetThrValLeuAlaProAlaTrp15AGCCCAACAACCTATCTCCTCCTGCTGCTGCTGCTGAGCTCGGGACTC101SerProThrThrTyrLeuLeuLeuLeuLeuLeuLeuSerSerGlyLeu101520AGTGGGACCCAGGACTGCTCCTTCCAACACAGCCCCATCTCCTCCGAC149SerGlyThrGlnAspCysSerPheGlnHisSerProIleSerSerAsp25303540TTCGCTGTCAAAATCCGTGAGCTGTCTGACTACCTGCTTCAAGATTAC197PheAlaValLysIleArgGluLeuSerAspTyrLeuLeuGlnAspTyr455055CCAGTCACCGTGGCCTCCAACCTGCAGGACGAGGAGCTCTGCGGGGGC245ProValThrValAlaSerAsnLeuGlnAspGluGluLeuCysGlyGly606570CTCTGGCGGCTGGTCCTGGCACAGCGCTGGATGGAGCGGCTCAAGACT293LeuTrpArgLeuValLeuAlaGlnArgTrpMetGluArgLeuLysThr758085GTCGCTGGGTCCAAGATGCAAGGCTTGCTGGAGCGCGTGAACACGGAG341ValAlaGlySerLysMetGlnGlyLeuLeuGluArgValAsnThrGlu9095100ATACACTTTGTCACCAAATGTGCCTTTCAGCCCCCCCCCAGCTGTCTT389IleHisPheValThrLysCysAlaPheGlnProProProSerCysLeu105110115120CGCTTCGTCCAGACCAACATCTCCCGCCTCCTGCAGGAGACCTCCGAG437ArgPheValGlnThrAsnIleSerArgLeuLeuGlnGluThrSerGlu125130135CAGCTGGTGGCGCTGAAGCCCTGGATCACTCGCCAGAACTTCTCCCGG485GlnLeuValAlaLeuLysProTrpIleThrArgGlnAsnPheSerArg140145150TGCCTGGAGCTGCAGTGTCAGCCCGACTCCTCAACCCTGCCACCCCCA533CysLeuGluLeuGlnCysGlnProAspSerSerThrLeuProProPro155160165TGGAGTCCCCGGCCCCTGGAGGCCACAGCCCCGACAGCCCCGCAGCCC581TrpSerProArgProLeuGluAlaThrAlaProThrAlaProGlnPro170175180CCTCTGCTCCTCCTACTGCTGCTGCCCGTGGGCCTCCTGCTGCTGGCC629ProLeuLeuLeuLeuLeuLeuLeuProValGlyLeuLeuLeuLeuAla185190195200GCTGCCTGGTGCCTGCACTGGCAGAGGACGCGGCGGAGGACACCCCGC677AlaAlaTrpCysLeuHisTrpGlnArgThrArgArgArgThrProArg205210215CCTGGGGAGCAGGTGCCCCCCGTCCCCAGTCCCCAGGACCTGCTGCTT725ProGlyGluGlnValProProValProSerProGlnAspLeuLeuLeu220225230GTGGAGCACTGACCTGGCCAAGGCCTCATCCTGCGGAGCCTTAAACAAC774ValGluHis235GCAGTGAGACAGACATCTATCATCCCATTTTACAGGGGAGGATACTGAGGCACACAGAGG834GGAGTCACCAGCCAGAGGATGTATAGCCTGGACACAGAGGAAGTTGGCTAGAGGCCGGTC894CCTTCCTTGGGCCCCTCTCATTCCCTCCCCAGAATGGAGGCAACGCCAGAATCCAGCACC954GGCCCCATTTACCCAACTCTGAACAAAGCCCCCG988(2) INFORMATION FOR SEQ ID NO:6:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 235 amino acids(B) TYPE: amino acid(D) TOPOLOGY: linear(ii) MOLECULE TYPE: protein(xi) SEQUENCE DESCRIPTION: SEQ ID NO:6:MetThrValLeuAlaProAlaTrpSerProThrThrTyrLeuLeuLeu151015LeuLeuLeuLeuSerSerGlyLeuSerGlyThrGlnAspCysSerPhe202530GlnHisSerProIleSerSerAspPheAlaValLysIleArgGluLeu354045SerAspTyrLeuLeuGlnAspTyrProValThrValAlaSerAsnLeu505560GlnAspGluGluLeuCysGlyGlyLeuTrpArgLeuValLeuAlaGln65707580ArgTrpMetGluArgLeuLysThrValAlaGlySerLysMetGlnGly859095LeuLeuGluArgValAsnThrGluIleHisPheValThrLysCysAla100105110PheGlnProProProSerCysLeuArgPheValGlnThrAsnIleSer115120125ArgLeuLeuGlnGluThrSerGluGlnLeuValAlaLeuLysProTrp130135140IleThrArgGlnAsnPheSerArgCysLeuGluLeuGlnCysGlnPro145150155160AspSerSerThrLeuProProProTrpSerProArgProLeuGluAla165170175ThrAlaProThrAlaProGlnProProLeuLeuLeuLeuLeuLeuLeu180185190ProValGlyLeuLeuLeuLeuAlaAlaAlaTrpCysLeuHisTrpGln195200205ArgThrArgArgArgThrProArgProGlyGluGlnValProProVal210215220ProSerProGlnAspLeuLeuLeuValGluHis225230235(2) INFORMATION FOR SEQ ID NO:7:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 71 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA to mRNA(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(xi) SEQUENCE DESCRIPTION: SEQ ID NO:7:AATTGGTACCTTTGGATAAAAGAGACTACAAGGACGACGATGACAAGACACCTGACTGTT60ACTTCAGCCAC71(2) INFORMATION FOR SEQ ID NO:8:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 37 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA to mRNA(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(xi) SEQUENCE DESCRIPTION: SEQ ID NO:8:ATATGGATCCCTACTGCCTGGGCCGAGGCTCTGGGAG37__________________________________________________________________________ | Ligands for flt3 receptors capable of transducing self-renewal signals to regulate the growth, proliferation or differentiation of progenitor cells and stem cells are disclosed. The invention is directed to flt3-L as an isolated protein, the DNA encoding the flt3-L, host cells transfected with cDNAs encoding flt3-L, compositions comprising flt3-L, methods of improving gene transfer to a mammal using flt3-L, and methods of improving transplantations using flt3-L. Flt3-L finds use in treating patients with anemia, AIDS and various cancers. | 0 |
This application is a continuation-in-part of Ser. No. 501,421, filed Aug. 28, 1974, now abandoned.
BACKGROUND OF THE INVENTION
The object of the instant invention is to provide a method for polymerizing in situ and durably fixing selected multivalent metal salts of carboxyl-containing vinyl monomers in and on natural fibers and synthetic fibers so that the metal carboxylate polymer may contribute special performance qualities to the fibrous substrate.
Another object of the invention is to provide a new method for rendering textiles flame resistant and mold inhibiting, for conferring resistance to the development of malador from perspiration in textiles, and for developing unique reversible hydroplastic qualities in textiles.
A further object of this invention is to develop self-sanitizing and biocidal qualities in fibrous substrates.
A still further object of this invention is to develop other fabric properties of commercial value by treatment of fibrous substrates with polymerizable multivalent metal-containing vinyl compounds.
It is known that a variety of water-soluble metal salts may be applied to fibrous substrates constituted of cotton or rayon fibers in order to fire proof these substrates; background is summarized by J. E. Ramsbottom ("The Fireproofing of Fabrics," His Majesty's Stationery Office, 1974). Commonly, the effectiveness of these agents was lost after boiling for one hour in water.
It is also known that a variety of metal salts of mercury and silver are effective antibacterial agents, as is, and when applied to fabrics; compounds of metals other than mercury and silver are of lesser importance as antibacterial agents but are more importent for "hidden" antibacterial action: e.g., aluminum and zinc salts applied as ingredients of cosmetic deodorants control bacterial flora of the skin, thereby preventing microbial decomposition and resulting malodor of perspiration in the axillary area. Background information is summarized by R. S. Mohamed (in Chapt. IX "Antibacterial and Antifungal Finishes" of Chemical Aftertreatment of Textiles, editors, H. Mark, N. S. Wooding, and S. M. Atlas, Wiley-Interscience, New York, 1971, p. 507) and by E. G. Klarmann (in Kirk-Othmer Encyclopedia of Chemical Technology, 2nd edition, Vol. 2, Interscience Publishers, New York, p. 622).
It is further generally known that the application and fixation of chemical agents on and in fibrous substrates increase the stiffness of the products. This stiffness is only little changed by wetting the composition. It is desirable, however, for the preparation of casts, molds, and rigidly shaped products that there be a transition from a flexible state to a rigid state. It is useful that this be accomplished as the wet fibrous substrate (completely flexible and moldable) looses water to reach equilibrium with ambient conditions of humidity and temperature.
It is known that carboxyl-containing vinyl polymers may be applied to fibrous substrates from aqueous solution, emulsion, or dispersion. Such coatings are limited to the surfaces of the fibrous substrates, often accumulating at fiber crossover points. The in-place neutralization of these coatings to convert them to heavy-metl salts occurs slowly and often with loss of some of the carboxyl-containing polymer. Moreover, the predominant deposition of these polymers on the surfaces of the fibrous materials has a detrimental effect on the overall balance of performance properties.
It has now been found that polymers of multivalent metal salts of water-soluble carboxyl-containing vinyl monomers can be deposited, efficiently polymerized in situ, and durably fixed in and on natural and synthetic fibers in compositions ranging from 100% cellulosic or natural fiber to 100% synthetic fiber by a process that involves a water-soluble polyvalent metal salt of a carboxyl-containing vinyl monomer, preferably with a small fraction of a water-soluble di- or polyfunctional vinyl monomer, and a free radical initiator applied from aqueous solution to the fibrous substrate and cured under specific conditions.
In accordance with the present invention, a process is provided for depositing polymer in and on various substrates with effectiveness for imparting flame retardancy, mold inhibition, resistance to the development of malodor from perspiration, and reversible plasticity in transition from the wet to the dry state.
The process is comprised of a treatment of the fibrous structure or textile material with the metal salt of the carboxyl-containing vinyl monomer, the presence or absence of an additional water-soluble monofunctional vinyl monomer, and a di- or polyfunctional vinyl monomer that are curable to network structures and durable finishes, imparting the above-mentioned properties to the fibrous substrates.
It was unexpectedly discovered that the forementioned metal salt vinyl monomers, in contrast to the free acid vinyl monomers can be polymerized to high conversions of monomer to polymer in and on fibrous substrates and that the polymers are durably fixed in and on these substrates. The metal salts of the carboxyl-containing vinyl monomers, together with the comonomers, penetrate well into the void and pore structures of fibers, especially fibers of the cellulosic and protein classes. The network polymeric structures are developed in these regions of the fiber as well as on the surfaces of the fibers; the results are relatively low contribution of the network polymer at low add-ons to the development of stiffness in the fibrous substrate and relatively high durabilities of the polymeric network structure.
It will become apparent in the light of illustrations and examples that the instant process provides a simple means for developing network structures involving metal salts of carboxyl-containing vinyl monomers. These metal salt-containing fibrous substrates have interesting performance qualities, especially reduced flammability of the substrates, increased durability of cellulosic substrates upon exposure to soil and weather, attractive self-sanitizing characterisitics, and unique plasticities. These performance characteristics are not achieved in similiar degree by impregnating a metal base into the pre-deposited carboxyl-containing polymer nor by coating fibrous substrates with heavy-metal neutralized carboxyl-containing polymer materials. The latter become insoluble during initial combination of the heavy-metal base and the carboxyl-containing polymer prior to contact with the fibrous substrate, and in any case, these coatings, once deposited, are limited to the outermost surfaces of the fibers and, because the network structure is limited to ionic crosslinks rather than to the carbon-chain crosslinks as the case in this invention, the polymeric deposits are nondurable.
In order to achieve desired conversions of heavy-metal containing monomers to polymers, desired fixation of polymers to substrates, and desired performance properites in the finished fibrous substrates, it is necessary to conduct the reaction with water-soluble free-radical initiators and to carry out the curing step under controlled conditions such that contacts with air during this stage are not excessive. In general, the curing step may be conducted in complete presence of air when the transfer of the heat to the substrate is achieved through conduction from hot solid surfaces, such as rolls "cans," calender, press, or conventional household iron. Transfer of heat might likewise be conducted without special precuations regarding the presence of air when the heat transfer medium involves steam or vapors, such as those from chlorinated hydrocarbons that are commonly used in textile and drycleaning operations. However, when the transfer of heat is conveyed through the gaseous state, it is desirable that air be diluted with an inert gas such as nitrogen or carbon dioxide or that it be diluted with steam; a direct blast of hot air on the substrate impregnated with the aqueous solution of reagents is undesirable and detrimental to polymerization and fixation. It is not essential that air be completely absent; the extent of dilution that is required is relatively low since the vaporation of water from the reagent solution on the substrate provides a degree of dilution that is sufficient in many cases.
It is desirable in order to achieve the full objective of this invention to include in the reagent formulation small amounts of a water-soluble di-or polyfunctional monomer. The presence of such a monomer in conjunction with a major monomer or monomers has general effects of raising the efficiency of conversion of the monomer to polymer and of improving the durability of the polymer.
The essence of the invention, then, is the discovery that high levels of efficiency of conversion of water-soluble metal salts of carboxyl-containing vinyl monomers to polymers can be realized on fibrous substrates under controlled conditions of cure that are well suited to use in textile mills to obtain modified substrates wherein the reduced combustibility, the biocidal characteristics, the sanitizing properties and the plastic characteristics conferred by the fixed polymers are the basis for valuable performance qualities in fibers, yarns, and textile and paper products.
This invention employs multivalent metal salts of water-soluble carboxyl-containing vinyl monomers. The metal ions involved may be magnesium, calcium, barium, aluminum, titanium, vanadium, chromium, iron, cobalt, nickel, copper, zinc, zirconium, iron, cobalt, nickel, copper, zinc, zirconium, molybdenum, silver, cadmium, beryllium, tungsten, mercury, lead, bismuth, yttrium, and rare earth elements. The water-soluble carboxyl-containing vinyl monomers include acrylic acid, methacrylic acid, and itaconic acid. The concentration of multivalent metal salts of water-soluble carboxyl-containing vinyl monomers range from 1-40 weight percent.
The water-soluble di- or polyfunctional vinyl monomers preferred for the purpose of this invention are methylenebisacrylamide and 1,3,5-triacyloylhexahydro-s-triazine. The concentration of polyfunctional monomers in the solution can vary between 0-3 weight percent.
Monofunctional comonomers are of definite value in this invention to provide facile complexing sites for the metal ion. Preferred comonomers include the following: acrylamide, methyacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, dimethyl-2-hydroxypropylaminemethacrylimide, diacetoneacrylamide, methylolated diacetoneacrylamide, N-vinyl-2-pyrrolidone, hydroxyethylacrylamide, and hydroxyethylmethacrylamide. Other water-soluble acrylic-type monomers may be employed in specific cases; these include hydroxyethyl acrylate and methacrylate, hydroxypropyl acrylate and methacrylate, and dialkylaminoethyl acrylates and methylacrylates. The concentration of monofunctional comonomers ranges from 0-15 weight percent.
Among the catalysts or initiators that are effective and preferred for use in this invention are: ammonium, sodium, and potassium persulfate, hydrogen peroxide, peracetic acid, and t-butylhydroperoxide. The concentration of catalysts in the solution ranges from about 0.03 to about 3.0 weight percent.
A wetting agent, although not essential, is commonly employed to facilitate contact of the aqueous solution of reagents with the surfaces of the fibers in the substrate and to facilitate penetration of the reagents into voids and pores of the fibers. Suitable wetting agents are alkali metal alkylsulfosuccinates and ethylene oxide derivatives of alkylated phenols and high molecular weight alcohols.
The vinyl monomers, the di- or polyfunctional reagent, the initiator, and the wetting agent are dissolved in a suitable amount of water for application to the fiber substrate. The total concentration of monomers in the solution can vary over a wide range, for example between 0.1 and 50%, although the preferred concentrations lie between 1 and 40% by weight.
The reagent solution is applied to the substrate in any suitable manner, but the common and preferred method involves immersion of the fiber substrate in the reagent solution followed by compression of the fiber substrate between rolls to express the excess solution. One or more such sequence of operations is commonly employed. The impregnated fibrous substrates are brought to elevated temperature to activate the initiator and to allow polymerization to occur rapidly and completely. The temperature of cure may range from 75° to 200° C and the periods allowed for initiation and polymerization can range from 120 minutes to approximately 0.5 minutes, the latter time being most appropriate for the highest temperature. Preferred temperatures for cure range from 90° to 160° C with corresponding duration of polymerization of 20 minutes down to one minute.
DESCRIPTION OF PREFERRED EMBODIMENTS
The following examples are given to further illustrate the present invention. The scope of the invention is not, however, meant to be limited to the specific details of the examples.
EXAMPLE 1
Solutions were prepared to contain 17.4 parts of acrylic acid, 0.6 parts of methylenebisacrylamide, 0.6 parts of ammonium persulfate, a trace of wetting agent, and water to bring the total to 100 parts by weight. One portion of this solution was set aside for the use as solution a. A second portion of this solution was neutralized with magnesium carbonate to the point that the pH of the solution was 7 and this was designated solution b. A third portion of this solution was brought to a pH of 7 with zinc carbonate and was designated solution c. Another portion of this solution was treated with aluminum chlorohydroxide and designated solution d. The final portion of this solution was neutralized with barium hydroxide to a pH of 7 and designated solution e. Swatches of 80 × 80 cotton printcloth were impregnated into these solutions individually, passed through squeeze rolls to remove the excess reagent, and subjected to cure at 120° C for 10 minutes in atmospheres of steam-nitrogen. The swatches of cured fabrics were rinsed thoroughly in very hot running tap water and air dried. Results are summarized in the following table.
__________________________________________________________________________ Match Test Moisture Water ofSample Conversion (%) Angle.sup.1 Regain (%) Imbibition (%)__________________________________________________________________________a 29 <0°.sup.2 6.5 32b 135.sup.3 100° 12.3 42.8c 116.sup.3 67° 9.7 25.4d 82.5 75° 9.4 26.1e 113.sup.3 67° 9.6 32.5Unmodified cotton <0°.sup.2 6.3 30.8__________________________________________________________________________ .sup.1 The match test angle for flammability of a sample of fabric has been described by Guthrie et al, Textile Research Journal, 23, 527-32, 1953. An angle of 0° is that between the hands of a clock at 12 o'clock; an angle of 180° is that between the hands of the clock a 6 o'clock; likewise, 90° represents the angle between the hands of a clock at 3 o'clock. A value of 180° in the above table indicates that a sample of fabric suspended vertically does not sustain combustion when the flame is removed. Correspondly, a value of 0° normally indicates that the combustion did not proceed at this angle. The higher the angle, the better the results. .sup.2 These samples continued to burn at 0°. .sup.3 The extent of conversion of monomer on fabric to fixed polymer on fabric was based on the weight of the initial air-dried fabric, the wet pickup of a reagent solution, and the weight of the final air-dried fabric. Values of conversion above 100% are due to increases in moisture regain for the polymer-treated cottons.
EXAMPLE 2
To a solution of 1.95 parts of acrylic acid and 0.1 part of methylenebisacrylamide in 100 parts of tetrahydrofuran were added five parts of titanium tetrachloride. The addition was conducted slowly and was accompanied by the formation of a white precipitate. The insoluble solid was removed and the tetrahydrofuran solution was concentrated to a thick syrup under vacuum. The syrup was dissolved in water, 0.07 parts of ammonium persulfate were added, and cotton fabric was impregnated in this solution. The impregnated swatch of fabric was subjected to a cure at 120° for 10 minutes in a steam-nitrogen atmosphere, and subsequently, was washed vigorously in very hot running tap water. The sample of fabric was found to contain 3.7% of titanium and 2.0% of polyacrylic acid by weight. A sample of this treated cotton fabric showed a match test angle of 120°: i.e., the sample no longer supported combustion at 120° after ignition at 180° and rotation to 120°.
EXAMPLE 3
Swatches of cotton fabric were immersed in reagent solutions similar to those described in Example 1, squeezed to remove excess reagent solution, cured for ten minutes at 120° in steam-nitrogen atmosphere, washed vigorously in very hot running tap water for 20-30 minutes, and air dried at room temperature. Samples of these treated fabrics were analyzed for metal ion content and for percent moisture. The results are as follows: Cotton fabric treated with magnesium acrylate reagent solution, 1.3% Mg, and 9.9% moisture; cotton fabric treated with zinc acrylate solution, 5.5% Zn, and 6.4% moisture; cotton fabric treated with aluminum acrylate reagent, 1.55% Al, and 6.52% moisture; and cotton fabric treated with barium acrylate reagent solution, 10.5% Ba, and 7.0% moisture. Samples of the barium acrylate-treated cotton fabric were impregnated with aqueous solutions containing 9% of dimethyloldihydroxyethyleneurea, 0.2% of wetting agent, 4% of polyethylene softener, and 0.8% of zinc nitrate hexahydrate, and heated in a forced draft oven for 3 minutes at 80° C and then three minutes at 160° C. The samples of fabric, before and after treatment with dimethyloldihydroxyethyleneurea, were subjected to a laundering and drying cycle; the sample of poly(barium acrylate)-cotton given the treatment with dimethyloldihydroxyethyleneurea showed improved durable-press rating. After four more laundering and drying cycles, the loss of weight of these samples of fabric was 2.2%, which was essentially identical to that (2.1%) of a conventionally crosslinked cotton fabric.
EXAMPLE 4
Samples of reagent solutions were prepared to contain 10.0 parts of acrylic acid, 7.4 parts of comonomer noted below, 0.6 parts of methylenebisacrylamide, 0.6 parts of ammonium persulfate, 0.1 part of a wetting agent (Tergitol TMN), metal carbonate sufficient to introduce stoichiometric amounts of the metal ion for each carboxyl group or to raise the pH to 7 or above, and water to bring the total to 100 parts by weight. In this case, it was convenient to prepare an initial solution from the acrylic acid and a major portion of the water into which the metal carbonate was introduced prior to the addition of the other ingredients. The comonomers were as follows: (a) acrylamide, (b) N-methylolacrylamide, (c) hydroxyethyl methacrylate, and (d) diacetoneacrylamide. Impregnations of swatches of cotton fabric in these solutions and subsequent steps were conducted as described in Example 1. Portions of these treated fabrics were also given a cure of three minutes at 160° C in a forced draft oven following the fixation treatment at 120° in steam-nitrogen. The samples of fabric were rinsed, boiled in distilled water for 1 hour, and air dried. The efficiencies of conversion of monomers to polymers, based on weight gains after launderings, were (a) 121%, (b) 87%, (c) 94%, and (d) 93%; results were insignificantly different for fixed samples versus the fixed and cured samples.
EXAMPLE 5
A reagent solution was prepared from 14.5 parts of acrylic acid, 0.5 parts of methylenebisacrylamide, 0.483 parts of ammonium persulfate, a trace of wetting agent, calcium hydroxide solution to adjust the pH to the level indicated below, and water to bring the total to 100 parts by weight. Samples of cotton fabric were padded in this solution, passed through squeeze rolls, placed on pin frames, cured for 5 minutes at 120° in an atmosphere of steam-nitrogen, washed thoroughly in hot running tap water, boiled for one hour in distilled water, and air dried. The results are summarized below:
______________________________________pH of treating Conversion of monomersolution to polymer on fabric______________________________________ 1.8 (no Ca(OH).sub.2) 29% 3.5 29% 4.0 54% 5.0 90% 7.0 92%11.0 95%______________________________________
EXAMPLE 6
A reagent solution containing acrylic acid, calcium hydroxide, methlenebisacrylamide, ammonium persulfate, and a trace of wetting agent was prepared; the amounts of materials and the conditions of reaction with cotton printcloth were the same as those described in Example 5, but the calcium hydroxide was present to the extent to develop a pH of 11.0. In a second reagent mixture, 0.2 parts of 1,3,5-triacryloylhexahydro-s-triazine (THT) was introduced in place of the methylenebisacrylamide (MBA), and in a third reagent mixture neither of these reagents was present. All treatments of cotton were conducted under the same conditions. The efficiencies of conversion and the durabilities of the polymers on cotton are summarized below.
______________________________________ Efficiency Retained Retained afterReagent of after 2% acidMixture Conversion.sup.1 Caustic Boil.sup.2 Treatment.sup.3______________________________________-MBA 75% 36% 0%+MBA 96% 72% 53%+THT 95% 75% 55%______________________________________ .sup.1 Determined by weight gain following air-equilibration and drying after a 1-hour boil in distilled water. .sup.2 Determined by weighing after a 1-hour caustic boil, thorough rinse in distilled water, air-drying, and air-equilibration; this followed the treatment in footnote.sup.1. .sup.3 Determined by weighing after soaking in 2% acetic acid for one hou and thorough rinsing, air-drying, and air-equilibration; this treatment followed the treatment described in footnote.sup.2
EXAMPLE 7
A reagent solution was prepared from 9.5 parts of acrylic acid, 0.5 parts of methylenebisacrylamide, 0.5 parts of ammonium persulfate, a trace of wetting agent, 8.2 parts of cupric carbonate, and water to bring the total to 100 parts by weight. Cotton fabric treated with this solution and cured for 3-5 minutes at 120° in a steam-nitrogen atmosphere had an add-on of 4.4%, corresponding to an efficiency of polymerization of 31%. A similar experiment was conducted, but in this case the cupric carbonate was replaced by cobaltous carbonate (7.8 parts). The add-on of network polymer of poly(cobaltous acrylate) was 7.5%, corresponding to an efficiency of polymerization of 56%. When silver oxide was employed as the base for neutralizing the acrylic acid, a network structure of poly(silver acrylate) was fixed on the cotton at similar efficiency of conversion, the fabric turned jet black in color.
EXAMPLE 8
Cotton fabric was treated with a reagent solution consisting of 15 parts of acrylic acid, 0.5 parts of methylenebisacrylamide, 0.5 parts of ammonium persulfate, 8.0 parts of aluminum chlorohydroxide, and water to bring the total to 100 parts by weight. The aluminum content of the finished fabric was 2.8%; this was reduced to 2.2% after the fabric was soaked in 2% acetic acid and then rinsed thoroughly in water.
EXAMPLE 9
A sample of cotton sateen fabric was immersed in a reagent solution consisting of 8.9% lead acrylate, 0.267% methylenebisacrylamide, 0.03% potassium persulfate, and the remainder water. The fabric was put through squeeze rolls to obtain a 90% wet pickup of reagent solution. The fabric was placed on a pin frame, cured for 10 minutes at 120°, washed thoroughly in hot running tap water, and air dried. The add-on was 8%, representing a 100% conversion of monomer to polymer on the fabric.
EXAMPLE 10
Reagent solutions were prepared from individual metal acrylates, methylenebisacrylamide, and ammonium persulfate. Magnesium, barium, calcium, and zinc acrylates were used. Monomer concentrations of metal acrylates varied from 14% to 40%; concentrations of methylenebisacrylamide varied from 0.5% to 1.33%; concentrations of catalyst ranged from 0.5% to 1.33%. In each case, additional base (involving the specific cation) was used if necessary to adjust the pH to 7.0. Samples of cotton sateen fabric were immersed in these reagent solutions, passed through squeeze rolls, cured for 10 minutes at 120°, washed thoroughly, and air dried. Results are summarized below.
______________________________________ Match TestAcrylate Add-on Angle Hand of Fabric______________________________________Magnesium 97% 180° RigidMagnesium 50% 90° StiffMagnesium 33% 80-90° Slightly stiffBarium 42% 70° Slightly stiffBarium 26% 60° Full bodiedBarium 20% 45° SoftCalcium 42% 85-90° StiffCalcium 29% 80-85° StiffCalcium 20% 60° Slightly stiffZinc 53% 85° Full bodied, softZinc 41% 85° SoftZinc 29% 50° Very soft______________________________________
All samples that were stiff when dried to ambient moisture content became soft and pliable when soaked in water. The change was most pronounced for the poly(magnesium acrylate)cotton fabric having an add-on of 97% of polymer. When dry (in equilibrium with ambient temperature and humidity), a strip of the treated fabric 15 mm wide maintained its horizontal status and was capable of supporting a load of 250 grams at a distance of 4 cm from the point at which the strip of fabric was held. When wet, the strip of fabric draped downward incapable of supporting the load from its own weight in the horizontal position. This fabric could be shaped while wet and then dried at elevated temperature or at room temperature to obtain a rigid fabric product that maintained the shape given to it while wet.
EXAMPLE 11
A solution was prepared to contain 12% acrylic acid, 23% basic zirconium acetate, 12% acetic acid, and 0.5% ammonium persulfate. Cotton fabric was padded through this solution, passed through squeeze rolls, cured for 10 minutes at 120°, washed thoroughly and dried. The add-on of polymer to the fabric was 18% corresponding to a 108% conversion of zirconium acrylate to polymer fixed on the fabric. The modified fabric passed the Streak Test (refer to Example 13), whereas unmodified cotton fabric failed the test.
EXAMPLE 12
Samples of cotton sateen fabric were treated with magnesium, calcium, zinc, and barium salts of acrylic acid in the manner described in Example 10. The uniquely large reductions in stiffness of these fabrics in going from the conditioned (70° F, 65% B.H.) to the water-wet state are summarized below.
______________________________________ Wet Stiffness/ConditionedFabric Sample Stiffness______________________________________Unmodified cotton 0.9Poly(magnesium acrylate)- cotton 0.05 to 0.06Poly(calcium acrylate)- cotton 0.018 to 0.025Poly(zinc acrylate)- cotton 0.50 to 0.64Poly(barium acrylate)- cotton 0.06 to 0.27______________________________________
EXAMPLE 13
Samples of cotton fabric were treated with metal salts of acrylic acid, methacrylic acid, and itaconic acid. Methylenebisacrylamide was present in all cases. The amounts of acid were varied to obtain the levels of add-on that are shown in the table. The metal ion was introduced in the form of the oxide or hydroxide in stiochiometric equivalence to the carboxyl group, unless indicated otherwise. The curing reactions were conducted in forced draft ovens at 120° C for 10 minutes. The resulting fabrics were boiled for 1 hour in distilled water, air-dried, and air-equilibrated. The samples of fabric were tested for antibacterial activity by the Streak Test (AATCC Test A2) which is a modification of the Agar Plate Method (W. Engle, "Self-Sterilizing Surfaces," Witherby, London, 8pp (1952)).
______________________________________ Metal Add-on of StreatAcid Ion Polymer Test.sup.1 Fabric Type______________________________________Acrylic Mg 30% M Printcloth" Ca 28 P Sateen" Ca 20 P "" Al 16 P Printcloth" Zn 32 P.sup.+ "" Zn 28 P.sup.+4 Sateen" Ba 26 P Sateen" Cu 4 P.sup.+2 Printcloth" Ag ca. 1 P.sup.+8 "" Co 7 p "" Ni 4 F "" Fe 4 P "Methacrylic Zn 4 P "Itaconic.sup.2 Zn 6 P "None None None F PrintclothNone None None F Sateen______________________________________ .sup.1 P = pass, indicating no undergrowth (superscript indicates mm zone of inhibition) or very slight undergrowth; M = marginal, indicating sligh undergrowth; and F = fall, indicating undergrowth or heavy undergrowth. .sup.2 This was half neutralized with Zn.
A wide variety of fibrous substrates, such as batting, pickerlap, sliver, roving, yarn, pressed sheets, or paper, may be treated equally as well as fabric which has served as the substrate in the foregoing examples. The substrates may consist of natural fibers or synthetic fibers; cellulosic fibers with or without polyester, nylon, or acrylic fibers are the preferred substrates.
EXAMPLE 14
A solution was prepared in the manner described in Example 1 c to contain 1.09% of zinc acrylate, 0.025 of THT, and 0.075% of potassium persulfate. Cotton fabric was treated in the manner described in Example 1. The weight gain was 1.03%. The fabric was laundered and dried for 25 cycles. At this point it showed 100% effectiveness in reduction of Staphylococcus epidermidis in the modified Quinn test. (This example illustrates about minimum concentration of primary metal salt monomer.)
EXAMPLE 15
A reagent bath was prepared in the manner described in Example 1 to contain 40% of magnesium acrylate, 3.0% of MBA, and 3.0% of ammonium persulfate. Fabric treated in this solution and cured for 5 minutes at 150° C had an add-on of 35% and showed reduced rate of combustion when ignited. (This illustrates concentrations of primary monomer and initiator which are considered to be suitable upper limits.)
EXAMPLE 16
A solution was prepared to contain 3% of zinc itaconate, 15% of acrylamide, 0.5% of MBA, and 0.5% of ammonium persulfate. A series of cotton/polyester fabrics was treated with this solution and cure was conducted at 140° C for 8 minutes. After laundering with Tide, the weight gains of the fabrics were found to be as follows: 100% cotton, 12%; 65% cotton, 11%; 50% cotton, 8%; and 35% cotton,, 4%. All samples of fabric rated P (pass, indicating no undergrowth) in the Streak Test involving Staphylococcus anreus and Escherichia coli. (This examples illustrates utilization of comonomer at high level of concentration.) | Water-soluble multivalent metal salts of carboxyl-containing vinyl monomers are polymerized in situ in fibrous substrates and fixed therein as network polymeric structures. This finish is useful for development of flame retardance, sanitizing characteristics, and other special performance qualities in fibrous compositions and fabrics. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 14/723,207, filed on May 27, 2015, and entitled “GRAPHICALLY PRINTED FURNITURE”, which itself claims priority to U.S. Provisional Patent Application Ser. No. 62/003,237, filed on May 27, 2014 and entitled “GRAPHICALLY PRINTED FURNITURE”, the contents of which being incorporated herein in their entirety.
FIELD OF THE INVENTION
The present invention relates to graphical treatment of furniture generally, and more particularly to imprinting graphics upon wood surfaces of furniture.
BACKGROUND OF THE INVENTION
Furniture pieces, whether decorative or functional, desirably exhibit unique and attractive aesthetic features, including, for example, carvings, embossments, color patterns, material overlays, and the like. Such aesthetic features add to the uniqueness and value of the furniture pieces.
Furniture pieces with painted designs, high-quality paintings depicting scenes, objects, and the like can be expensive and impractical for large-scale production. Applicant has discovered that the application of a pre-recorded digital image to a furniture work piece can create the desired aesthetic appearance in an economic and scalable process.
SUMMARY OF THE INVENTION
By means of the present invention, digital images may be imprinted as graphics upon wood furniture work pieces. The digital images may be photographs, optical scans, or otherwise digitally generated or captured image data compiled into a digital image file. The digital image file may be processed by computer software in the generation of a print file that may be executed by a printer to apply ink, toner, or other colorant in a predetermined pattern upon the wood furniture work piece to transfer the image to a print surface of the wood furniture work piece.
In one embodiment, a method for printing a graphical image on a wood furniture work piece includes providing a flatbed ultraviolet (UV)-curable ink printer having a printer controller for operating a print head, and a flat printer bed that is sized to accommodate the wood furniture work piece, as well as providing a processor-enabled computer with software means for generating an executable print file from digital image data. The method includes preparing the wood furniture work piece by sanding a print surface of the work piece with an abrasive having a grit rating of no greater than 150, and placing the wood furniture work piece at the printer bed in an orientation for the print surface to receive UV-curable ink from the printer. A digital image data file is provided to the computer, and a software means is directed to generate the executable print file, and to deliver the executable print file to the printer controller to operate the printer controller in accordance with the executable print file. Prior to priming the print surface of the work piece, the printer is operated to print the graphical image on the print surface with UV-curable ink. Subsequent to printing the graphical image, the print surface is sanded.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a wood furniture work piece of the present invention; and
FIG. 2 is a flow diagram of a method for printing a graphical image on a wood furniture work piece of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The objects and advantages enumerated above together with other objects, features, and advances represented by the present invention will now be presented in terms of detailed embodiments which are intended to be representative of various possible embodiments of the invention. Other embodiments and aspects of the invention are recognized as being within the grasp of those having ordinary skill in the art.
Unless otherwise apparent or stated, directional references, such as “upper”, “lower”, “top”, “bottom”, “vertical”, “horizontal”, and the like are intended to be relative to the orientation of an embodiment of the invention as typically employed by a user.
The present invention is directed to printing a graphical image on a wood furniture work piece, and particularly printing the graphical image on a print surface of the work piece before the print surface has been primed. For the purposes of this application, the terms “prime”, “primed”, “priming”, and the like refer to any treatment of or coating to a print surface of the wood furniture work piece, except only cleaning agents such as solvents that are not intended for permanent residence at the print surface, or for absorbing into the wood furniture work piece. Example priming agents or materials include paint, stain, varnish, sealers, gels, and other materials that may be applied as a coating or a penetrant onto or into the surface of a wood work piece. Example cleaning agents, by contrast, include solvents such as acetone that are intended to be only temporarily present at the surface of the work piece, and are typically removed either manually or by evaporation prior to any further treatment of the wood surface. For the purposes hereof, physical manipulations of the wood surface, including sanding, grinding, debriding, and the like are not considered to be “priming” the surface.
An example wood furniture 10 of the present invention is a table as illustrated in FIG. 1 , includes one or more legs 12 and a tabletop 14 . For convenience in processing, tabletop 14 may be employed as the work furniture work piece to which one or more legs 12 are secured after printing, though it is contemplated that the entire furniture piece 10 may instead be considered the wood furniture work piece. In typical embodiments of the present invention, tabletop 14 may be used as the wood furniture work piece having a generally planar print surface 16 upon which the graphical image may be printed. It is contemplated, however, that the print surface 16 may be non-planar for certain wood furniture work pieces. The wood furniture work pieces of the present invention typically include wood tabletops, such as for dining tables, end tables, coffee tables, and the like, as well as wood countertops, wood bar tops, wood butcher blocks, wood serving plates, and wood presentation pieces primarily used for displaying or serving food.
The wood furniture work piece may be prepared conventionally, including by ripping rough lumber to desired stave sizes, and then adhering the pieces together to produce the tabletop or other furniture piece. The assembly may then be trimmed and sanded to the desired exact dimensions. The wood furniture work piece is prepared for printing by sanding the print surface 16 with an abrasive. It has been found by the applicant that certain abrasive treatment of the print surface 16 substantially aids in the aesthetics and durability of the printed graphical image. In particular, Applicant has determined that sanding print surface 16 with an abrasive having a grit rating of no greater than 150 results in a print surface that is most receptive to the UV-curable inks employed in the printing process of the present invention. In some embodiments, print surface 16 is sanded with sandpaper as the abrasive in a sequence of progressively finer (larger grit rating) sandpaper of between grit ratings of 80-150. In a particular example, a wide belt sander is used to sand print surface 16 sequentially with first a sand paper having a grit rating of no greater than 80, followed by sanding with a sandpaper having a grit rating of no greater than 120, and further followed by sanding with a sandpaper having a grit rating of no greater than 150. The wide belt sander treatment may then be followed by sanding treatment with an orbital sander using, in order, a sandpaper having a grit rating of no greater than 80, followed by sanding with a sandpaper having a grit rating of no greater than 120, and further followed by sanding with a sandpaper having a grit rating of no greater than 150.
The sanded print surface 16 may then be cleaned with a cleaning agent, such as acetone, by wiping print surface 16 with a cloth moistened with acetone or other cleaning agent.
A printer useful in the printing process of the present invention includes an ultraviolet (UV) ink-curable printer with a flat printer bed that is sized to accommodate the wood furniture work piece, and a printer controller for operating a print head. An example UV printer useful in the present invention is available from Canon, Inc. under the brand name OCE Arizona UV Flatbed Printers having a 98 inch by 49 inch by 2 inch flat printer bed, including a vacuum hold-down feature. The UV printer is driven by a printer controller that is communicatively coupled to appropriate software that is configured for generating print files that are executable by the printer controller. Operation of the software is performed by a processor-enabled computer that is communicatively linked to the printer controller.
The prepared wood furniture work piece is placed at the printer bed in an orientation for the print surface to receive UV-curable ink from the printer. Once the wood furniture work piece is appropriately positioned at the printer bed, the printer controller is operated to initiate print head operation to apply the UV-curable ink to the print surface 16 of the work piece in accordance with the executable print file delivered to the printer controller from the computer. Such executable print file is generated by the software from a digital image data file inputted to the computer by a user either directly, or through an external device, such a camera, scanner, external hard drive, or the like. Image data files in .jpg, .jpeg, .pdf, .tiff, and other image data file types are expected to be processable by the software.
As indicated above, an aspect of the present invention is printing the graphical image to the print surface 16 with UV-curable ink prior to priming print surface 16 of the work piece. It has been found by the Applicant that such a processing order significantly benefits the aesthetics and durability of the printed graphical image. Conventional image printing processes, by contrast, require priming the print surface of the work piece with a base colorant or other coat layer prior to allegedly provide a “consistent” color background.
Subsequent to the graphical image printing and curing, the wood furniture work piece is removed from the print bed, and the print surface sanded to obtain the desired aesthetic appearance of the printed image. Preferably, this sanding step is performed with an abrasive, such as sandpaper, with a grit rating of at least 180.
Subsequent to the finishing sanding step, a range of techniques may be used to add additional customization to the appearance of the print surface of the wood furniture work piece. In some embodiments, a stain, varnish, and/or paint may be applied to the printed and sanded print surface 16 . In some embodiments, a stain may be applied by cloth to the printed and sanded print surface 16 , and allowed to dry for 30-120 minutes. A varnish seal coat available from ML Campbell as a conversion varnish may be applied with a spray gun to the stained surface, and allowed to dry for 30-120 minutes. The first seal coat layer over the stain may be sanded with a sandpaper abrasive having a grit rating of at least 220. Second and additional seal coats of conversion varnish may be applied with the spray gun, with each coat application being allowed to dry for 30-120 minutes, followed by sanding with a sandpaper abrasive having a grit rating of at least 220. The one or more layers of conversion varnish comprise a top coat that may protect the printed graphical image and print surface 16 from damage, and may further enhance the aesthetic appearance of the finished work piece.
The invention has been described herein in considerable detail in order to comply with the patent statutes, and to provide those skilled in the art with the information needed to apply the novel principles and to prepare and use embodiments of the invention as required. However, it is to be understood that various modifications can be accomplished without departing from the scope of the invention itself. | A method for printing a graphical image on a wood furniture work piece includes printing on an unprimed print surface of the wood furniture work piece with an ultraviolet-curable ink printer. The print surface of the wood furniture work piece may be prepared for printing by sanding with an abrasive. The graphical image may be converted from a digital image data file sourced from, for example, a camera, an optical scanner, or the like. In this manner, durable digital images may be permanently applied to wood furniture work pieces such as tabletops. | 1 |
TECHNICAL FIELD
[0001] This invention relates to stabilization of the extremely unstable substance atorvastatin, in its crystalline, but particularly amorphous state. The stabilization can be used for the pure substance, but also for the substance in solid or liquid dosage forms.
BACKGROUND ART
[0002] The hemicalcium salt of (3R,5R) 7-[3-phenyl-4-phenylcarbamoyl-2-(4-fluorophenyl)-5-isopropylpyrrol-1-yl]-3,5-dihydroxyheptanoic acid of formula I
[0000]
[0000] known under the non-proprietary name atorvastatin (I), in the text sometimes called the calcium salt of atorvastatin, is produced according to published patents (U.S. Pat. Nos. 4,681,893 and 5,273,995). The said drug is an important representative of hypolipidemic and hypocholesteric drugs.
[0003] Atorvastatin can exist in various crystalline forms or in an amorphous form. The preparation of various polymorphs is described in published patents (U.S. Pat. No. 5,969,156; U.S. Pat. No. 6,121,461; WO 03/004470 and WO 01/36384), the amorphous form in patent U.S. Pat. No. 6,087,511. The crystalline forms are, according to the above-mentioned patents, much more stable than the amorphous form.
[0004] Also the authors of patent EP 680320 pointed out that the substance atorvastatin has insufficient stability. It is stated in the specification of the said patent that it is an unstable substance sensitive to heat, humidity, low pH of the environment, and light, particularly UV radiation. A composition whose main feature are basic inorganic substances is the solution to this problem. Hydroxides, oxides or carbonates are the preferred anions. As to cations, most often calcium, magnesium, and lithium salts are stated. Calcium carbonate is stated as the best solution. Antioxidants of anisole or ascorbate type are also added to the recommended composition.
[0005] In WO 00/34525, the stabilization of a dosage form is solved by adding buffers, especially citrates.
[0006] WO 01/76566 solves the stabilization of a dosage form by adding a basic polymer containing amino or amido groups, for example polyvinylpyrrolidone.
[0007] WO 01/93859 solves the stabilization of HMG-CoA inhibitors, and among them also of atorvastatin, using a substance capable of binding and neutralizing carbon dioxide. Carbon dioxide is, according to the authors of the application, the most important factor leading to the instability of the product. Its effect is ascribed to the lowering of pH, which results in the decomposition of hydroxyacids particularly to their lactones. It is pointed out that gastric troubles may be caused if a medicine with a high content of alkaline substances is administered to patients. This fact limits the possibility of improving the stability by adding a stabilizer to the dosage form.
[0008] WO 02/072073 shows the relation between the pK a value of atorvastatin and the pH value of an aqueous solution of a solid dosage form. According to the quoted application, the dosage form should contain such ingredients which would cause the pH of solution to reach a value not lower than pK a +1.
[0009] Accordingly, it follows from the prior art that the main methods how to solve the problem of the stability of atorvastatin in a dosage form were either increase of the pH of the dosage form, or prevention of the lowering of the pH by CO 2 contained in the atmosphere.
[0010] Despite these measures, the dosage forms of atorvastatin, and particularly if amorphous atorvastatin is in these forms, showed significant instability. Although the formation of undesirable products such as the lactone of atorvastatin was prevented, the formation of other unknown substances occurred. The active substance itself, not in the dosage form, showed even worse stability. Therefore, it was necessary to store and transport amorphous atorvastatin at about −20° C. Naturally, these measures increased the costs of the said operations.
[0011] In addition to the above-mentioned methods, a new method for the preservation of substances susceptible to oxidation with the use of substances trapping air oxygen, often called oxygen absorbers, has been developed. Mitsubishi Gas Chemical (Tokyo, Japan) have developed bags absorbing oxygen based on a reaction of iron under the trade name Ageless (Yoshikawa, Y., Amemiya, A.; Komatsu, T.; Inoue, Y.; Yuyama, M., Oxygen Absorbent for Food Packaging. Jpn. Kokai Tokkyo Koho, Showa 56-33980, 1978). Similar products are also offered, for example, by Multisorb Technologies, Inc. under the trade name Fresh Pax™ or by Standa Industry under the trade name ATCO.
[0012] Many products are available nowadays. They are based on humidity-activated oxygen absorbers, self-activating absorbers, ultraviolet-radiation-activated absorbers, radiation-activated absorbers, microwaves-activated absorbers, absorbers activated by a combination of activation processes, or absorbers not requiring any activation.
[0013] In patent application US 2002/0132359, the use of these absorbers for pharmaceutical preparations sensitive to oxygen is applied for protection. The application is carried out in a blister packing where the absorber is situated between the lid and the blister itself. The application further informs that it is very difficult to find out which of the substances will be susceptible to oxidation. The problem subsists in the fact that often the oxidation does not follow the classical Arrhenius equation, and that is why accelerated stability tests, which are successfully used for other decomposition reactions, fail. The patent application further contains a list of some pharmaceutical substances, which could be sensitive to oxygen. HMG-CoA inhibitors simvastatin or lovastatin are the most relevant ones among them. Both these substances contain a system of conjugated double bonds in a carbocyclic system, which can result in sensitivity to oxygen.
[0014] However, new facts have now surprisingly shown that degradation of atorvastatin, which does not contain this carbocyclic system is also caused by atmospheric oxygen. Moreover, it has been shown that the usual solution to the problem—the pharmaceutical composition containing a substance susceptible to oxidation—, that is the use of a formulation with an antioxidant, has, in the case of atorvastatin (stated, for example, in EP 680320), failed (example 6 of this document).
[0015] The instability of atorvastatin is, according to the above-mentioned patents, usually ascribed to the increased sensitivity to the acidity of the environment, which causes that atorvastatin may dehydrate to the lactone of atorvastatin of formula II
[0000]
[0016] Lactonization is an acid-catalyzed process proceeding probably via the free dihydroxyacid of atorvastatin. Therefore, a solution subsists in adding basic substances to the dosage forms.
DISCLOSURE OF THE INVENTION
[0017] This invention consists in a method for the stabilization of the pharmaceutical active solid substance atorvastatin embedded in a gaseous mixture, the method comprising maintaining a maximum partial pressure of oxygen in the surrounding gaseous mixture of 2 kPa.
DETAILED DESCRIPTION OF THE INVENTION
[0018] We have shown, with the help of exactly controlled experiments, that the instability is also caused by oxidation by atmospheric oxygen. Particularly amorphous atorvastatin shows significant instability towards oxidation, whereas crystalline forms are somewhat more stable. However, this is caused by statistical factors because a substance firmly incorporated in a crystal lattice has a lesser probability to react with atmospheric oxygen than a substance in an amorphous form (Stephen R. Byrn: Solid State Chemistry of Drugs , Academic Press, 1982). Therefore, the oxidative decomposition of crystalline forms of atorvastatin is slower than that of the amorphous form. This is also important for dosage forms because, for example, mechanical stress when producing tablets may lead to partial collapse of the crystalline structure causing instability of the dosage form.
[0019] The following experiments were carried out in order to determine the instability of atorvastatin. The purpose was to find out which factors lead to the degradation of the product.
1. Set of stress tests. The stock solution of atorvastatin (2 ml) was gradually subjected to the following experiments:
a. boil (24 hr) with 2 ml of 0.2 N hydrochloric acid,
b. boil (24 hr) with 2 ml of 0.2 N acetic acid,
c. boil (24 hr) with 2 ml of 0.2 N sodium hydroxide,
d. boil (24 hr) with 2 ml of 4% hydrogen peroxide,
e. boil (24 hr) with 2 ml of water,
f. irradiation with UV radiation (5 hr),
g. irradiation with visible light (24 hr),
h. solid substance heated at 100° C. for 24 hr,
i. solid substance subjected to UV radiation (5 hr),
j. solid substance subjected to visible light (24 hr).
[0021] The results of analytical assessment (HPLC) are summarized in the following table (Table 1):
[0000]
TABLE 1
Conditions
Content of Atorvastatin, %
24 hr boil in 0.1 N HCl
2.1
24 hr boil in 0.1 N AcOH
83.2
24 hr boil in 0.1 N NaOH
72.0
24 hr boil in 2% H 2 O 2
54.8
24 hr boil in water
88.4
5 hr under UV in water
64.3
24 hr in the light
104.5
substance 24 hr, 100° C.
96.3
substance 5 hr, UV
99.3
substance 24 hr, light
96.5
[0022] What could particularly be seen from the results was instability in the acid environment. Furthermore, the substance decomposed significantly also in a solution when subjected to UV radiation, which is in conformity with literary data ( Tetrahedron 49,10, 1979-1984, 1993).
[0023] Decomposition by hydrogen peroxide turned out to be another significant factor.
[0024] In order to make the carried-out experiments more precise, stability tests of solid amorphous atorvastatin and of several selected dosage forms were established. As to containers, polyethylene (PE) and an aluminium foil with a sealable PE layer (Al+PE) were used. Some of the stability data were determined in nitrogen atmosphere (N 2 ) (with a partial pressure of oxygen of roughly 3 kPa).
[0025] The results of these stability tests are summarized in Table 2.
[0000]
TABLE 2
Time, months
Temp., ° C.
Package
P O , kPa
Impurities, %
0
—
entry
—
0.21
3
5
2x RE
18
0.39
3
5
PE + Al
18
0.34
3
5
PE + Al
3
0.34
3
25
2x PE
18
0.77
3
25
PE + Al
18
0.63
3
25
PE + Al
3
0.43
6
5
2x PE
18
0.83
6
5
PE + Al
18
0.71
6
5
PE + Al
3
0.44
[0026] It is obvious from the table that at 25° C., the content of impurities already after 3 months markedly depends on the partial pressure of oxygen in the package. At 5° C. this dependency manifests more markedly only after 6 months. Also the effect of the manner of packaging on the final content of impurities can be seen from the table. The substance in an air-tight PE+Al package shows a better stability than in permeable PE bags.
[0027] In order to precisely determine the decomposition mechanism, the following experiments examining only the oxidative decomposition of atorvastatin were carried out. A recent publication/ Pharmaceutical Development and Technology, 7(1), 1-32 (2002)/described a set of experiments which are suitable for the recognition of oxidation of substances and for the determination of its mechanism.
[0028] The following experiments were carried out:
[0000] a. oxidation of a 1% solution of atorvastatin in the system of ethyl acetate-acetonitrile (1:1) at 40° C. using a radical initiator (2,2′-azobiscyanopentanoic acid) at a pressure of 1 MPa of oxygen;
b. oxidation of a 1% solution of atorvastatin in the system of ethyl acetate-acetonitrile (1:1) at 40° C. without a radical initiator;
c. control experiment in the system of ethyl acetate-acetonitrile (1:1) at 40° C. using a radical initiator (2,2′-azobiscyanopentanoic acid) in an inert atmosphere of argon (the partial pressure of oxygen found as being about 1 kPa).
[0029] The results are summarized in Table 3.
[0000]
TABLE 3
Time, hours
Initiator
P O , MPa
Impurities, %
0
entry sample
0.49
24
yes
1
6.42
48
yes
1
24.37
72
yes
1
30.93
24
yes
0.001
0.98
48
yes
0.001
1.38
24
no
1
9.27
[0030] It follows from the results that atmospheric oxygen itself can oxidize atorvastatin and no radical initiator is necessary for the oxidation. The control experiment in an inert atmosphere of argon showed a small increase in the amount of the lactone of atorvastatin caused by increased temperature and slightly acidic radical initiator.
[0031] The comparison of the profile of impurities from stability tests (Table 2) with the profile of impurities created by oxidation using HPLC-MS was another result of the experiment. It has shown that all significant impurities the amount of which increased during the stability tests, with the exception of the lactone of atorvastatin, are formed by oxidation. On the basis of this knowledge of oxidative decomposition, a solution was looked for which would prevent the contact of the substance itself or the substance in a dosage form with atmospheric oxygen. According to our, and also in literature published/K. C. Waterman, M. C. Roy: Pharmaceutical Development and Technology, 7 (2), 227-234 (2002)/, experience, it is very difficult, when packing the dosage form, to reach the partial pressure of oxygen lower than 2-3 kPa without using a vacuum step. This is, however, a sufficient amount to cause oxidation of the product still occur. An especially suitable method how to achieve a lower concentration of oxygen (as low as below the value of 0.1 kPa) is the use of either vacuum or oxygen absorbers. Therefore, further experiments were carried out with the use of vacuum or of oxygen absorbers. The experiments were carried out with oxygen absorbers Ageless™ from Mitsubishi Gas Chemical and ATCO from Standa Industry. Many other commercially available absorbers can also be advantageously used; for example FreshPax™ (Multisorb Technologies), O-Buster™ (Hsiao Sung Non-Oxygen Chemical Co), Biotika Oxygen Absorber (Biotika) and the like.
[0032] Other aspects of the invention include packaging under nitrogen or argon by a newly developed method. As cited above, pharmaceutical packaging under nitrogen made in the usual manner into a blister does not achieve a partial pressure lower than 2-3 kPa. These values are not sufficient in the case of an especially sensitive substance like atorvastatin.
[0033] In our below described method of packaging, values of the partial pressure of oxygen lower than 1 kPa, in a preferred embodiment lower than 0.4 kPa, can be achieved in a usual pharmaceutical blister.
[0034] The above-mentioned results show that oxidative degradation is an important factor mainly for amorphous atorvastatin and this fact has to be taken into consideration when storing the substance or the final dosage form. We have shown that the use of oxygen absorbers significantly improves the storability of amorphous atorvastatin (examples 1 and 2). It clearly follows from the results that the protection of atorvastatin from atmospheric oxygen completely prevents its decomposition. When using oxygen absorbers, the substance can be then stored at 25° C. without any limitations, which means, in comparison with the storage at a lower temperature, a significant decrease of costs. The substance can also be stored in other containers which let oxygen through partially with the final concentration of oxygen lower than 1%, ideally lower than 0.1%. The substance can also be advantageously packed in an inert atmosphere, which makes the lifetime of the oxygen absorber longer and the initial exothermic reaction when trapping oxygen by the absorption bag milder. The needed capacity of the absorption bag and the resultant equilibrium concentration of oxygen (in ppm) can be calculated from the following equation (Vinod Daniel, Frank L. Lambert: Waac Newsletter 15, 2, 1993, 12-14, 1993):
[0000] [O 2 ]=L/ 12.7 C
[0000] wherein L is the leakage rate of oxygen out of the container in ppm/day, C is absorbance, which is the ratio of the capacity of the absorption bag and the total volume of the container.
[0035] The stabilization method of this invention relates both to the active substance itself and the dosage forms containing atorvastatin, especially atorvastatin in the amorphous state. The described dosage forms of atorvastatin contain approximately 1 to 60% by weight, preferably 3 to 20% by weight of the active substance and several auxiliary substances with various functions, especially to help to release the active substance in a patient's body at the desired rate, to stabilize the dosage form against chemical decomposition or mechanical influences. In order to stabilize atorvastatin in the dosage form, it is usually recommended to add a basic substance, calcium carbonate being mentioned as the most preferable one.
[0036] Such very low partial pressure of oxygen can be achieved, in industrial practice, either by filling under an inert gas, adapted in accordance with the invention, or by a new technique of packaging under reduced pressure or by use of oxygen absorbers.
[0037] The production of blisters is carried out by welding together two sheets. The lower sheet is first shaped in such a manner that a required number of cavities is formed, which cavities correspond in their shape and size to a unit dose of the drug (most often a tablet or capsule). In a further step, the unit dose of the drug is inserted into each of the cavities. The lower sheet, filled in this manner, is overlaid with the upper sheet and both sheets are closely pressed together by means of a pressing roll. In the subsequent step, both sheets are welded together and the welded sheet is cut into individual blisters. A usual method of filling a solid dosage form into the most often used pharmaceutical package, a blister, is carried out in such a manner that the shaped sheet band with tablets passes through a space filled with an inert gas, wherein the upper sheet is pressed against it and welding occurs subsequently. In the atmosphere inside such package there is a partial pressure of oxygen of 2-3 kPa. This state is sufficient with many pharmaceutical substances for their stabilization. However, it cannot prevent oxidation totally and, with especially sensitive substances such as atorvastatin, especially in its amorphous form, it does not ensure complete stability thereof, which leads to the necessity of shortening of the usable life of the composition. Problems of applying the usually employed package under nitrogen with blisters include insufficient wash-out of oxygen from the cavities with tablets, which they entrap with themselves, into the space filled with the inert gas; insufficient tightness of the upper sheet with the lower one immediately before the welding; and possible penetration of air into the cavities immediately before the welding not being avoided in a suitable manner.
[0038] The new method of packaging has been developed by optimization of the parameters of the flow of the inert gas and its distribution in accordance with the packaging process. The main feature of this aspect of the invention is introducing the inert gas into the cavities of the lower shaped sheet with such intensity that the content of the gas in the cavity exchanges at least once, preferably three times. This provision itself can lower the resulting partial pressure of oxygen significantly below 2 kPa, in some cases below 1 kPa. In accordance with a preferred embodiment of the invention, after shaping the cavities in the lower sheet band and filling the same with dosage units, the band enters a purging chamber, constituted by a set of nozzles for targeted introduction of the inert gas into the cavity with the dosage unit and diversion channels for delivery of washed-out air. Air is completely washed out from the cavities by a stream of the inert gas, flowing through the nozzles under a precisely determined and monitored pressure, or flow rate, resp. The flow rate of the inert gas is set in the range of 180 to 3000 l/h. Preferably the flow rate is in the range of 500 to 1500 l/h. The purging chamber is, together with a wiping station (welding of the upper—cover Al sheet with the lower—shaped and filled-in Al sheet), covered in a box with permanent inert atmosphere and a lower pressure above atmospheric than in the purging chamber for sufficient delivery of the washed-out air. In the box there is monitoring of the residual oxygen values with a feedback to the machine run.
[0039] As shown below, this method results, under industrial conditions, in a pharmaceutical package with blisters containing a gas with partial pressure of oxygen lower than 0.4 kPa, usually between 0.2 and 0.3 kPa.
[0040] In pharmaceutical packaging under reduced pressure of 0.3-10 kPa it is more advantageous to use a strip rather than a blister. A strip is a type of packing wherein two sheets are again welded together but none of the sheets is shaped as with the classical blister. The dosage form (a tablet, gelatin capsule, granulate and the like) is inserted into the partially welded strip and not only the filled-in part of the strip, and also the part that will be filled in the subsequent step, are at the same time evacuated, the evacuation taking place for the whole time of the welding operation, wherein complete, air-tight closing of the individual dosage form into the aluminium sheet (strip) occurs.
[0041] In the solution by means of oxygen absorbers it is very advantageous if the substances capable of absorbing oxygen are coated on the upper sheet (i.e., the sheet that is not shaped) and separated from the pharmaceutical composition by a permeable membrane. In such a case each dosage unit is protected individually and, after consumption of only a portion of the package, the residue remains protected.
[0042] Another solution resides in packaging of the dosage units into blisters, at last one sheet being selected from such a material that is well permeable for oxygen (but preferably poorly permeable for steam). The whole blister is in turn closed in a pouch, in which an absorber is located. It can be for example a polypropylene blister, coated in an Al—Al pouch. The solution by means of oxygen absorbers has an advantage of technically more simple makeup, wherein it is not necessary to coat the sheet with an absorber.
[0043] Surprisingly, it has been shown that there is a close relation between atmospheric oxygen and a suitable formulation. Some formulations, which are relatively successful when storing the dosage form with normal access of oxygen, turn out to be unsuitable for oxygen trapping. On the contrary, those that are less suitable in normal conditions, strengthen the stabilization influence of oxygen trapping. Products, which are in no immediate relation to the oxidation are at fault. The lactone of atorvastatin of the above-mentioned formula II is an example. The basic action of calcium carbonate prevents, in normal conditions, the acid-catalyzed reaction and limits the formation of the lactone (EP 680320). When reducing the amount of oxygen, this effect of calcium carbonate is lowered and the concentration of the lactone increases with time. The use of a base like magnesium oxide or hydroxide is usually considered less suitable. In normal conditions, i.e., with the access of oxygen, the formulation with a magnesium base leads not only to the increase in the amount of usual impurities, but also to the formation of many impurities which are not identified when using calcium carbonate. On the contrary, under reduced partial pressure of oxygen, a base of this type strengthens the stabilization effect described above for the 100% substance. It is again a case of complex stabilization, i.e., not only mere limitation of apparent oxidation products. Therefore, stabilization of atorvastatin by combining the effects of the atmosphere with a partial pressure of oxygen lower than 2 kPa, especially lower than 0.4 kPa, and of magnesium oxide or of packaging under an inert atmosphere, or vacuum, and of magnesium oxide, is considered an especially advantageous embodiment according to this invention.
[0044] A further aspect of the invention resides in a suitable analysis of the oxygen content in the pharmaceutical package, without which it would not be possible to carry out the invention. The problem of analysis of the composition of the gas in the pharmaceutical package (especially in blisters) is complicated by necessity to avoid ingestion of atmospheric oxygen from the surroundings when taking a sample, or by lowering the actual oxygen content in the blister in an attempt to avoid this fault when taking a sample.
[0045] Three measurement methods have been developed:
[0000] 1. Measurement A: Measurement of Residual Oxygen by Gas Chromatography with Collection of Gas and Manual Injection.
[0046] Residual oxygen in the inert atmosphere is measured by gas chromatography with a thermal conductivity detector (TCD). The gas is separated in a column containing, as the phase, a molecular sieve, which allows separation of permanent gases. Collection of samples s manual, with readjustment of the blister by deposited septa or by means of dosing from a broken blister by a loop device.
2. Measurement B: Measurement of Residual Oxygen by Means of a Microsensor.
[0047] Residual oxygen in the inert atmosphere is measured directly in the blister by means of a microsensor, which is situated in a needle. This needle is, through a closed space depleted of oxygen (a chamber purged by nitrogen—measured by this sensor as the background), stuck directly into the individual cells in the blister. The microsensor is based on the suitable instrumental method, which is known as selective for oxygen.
3. Measurement C: Measurement of Residual Oxygen by Means of an In-Line Set of Sensors
In-Process Control
[0048] Residual oxygen in the inert atmosphere of the machine is measured directly by means of sensors that are situated in all inertized parts of the packaging machine, including the inlet of nitrogen into the blister cells. These sensors monitor also the outer space.
[0049] Obviously, from the point of view of authenticity of the analysis result, methods B and C are more preferable, since no disruption of the blister occurs and possibilities of contamination during analysis are negligible. Moreover, method C unveils very quickly possible faults in industrial packing.
[0050] This invention is elucidated in greater detail in the following working examples. These examples are of an illustrative nature only and do not limit the scope of the invention in any way.
EXAMPLES
Example 1
[0051] Amorphous atorvastatin (1 g) was sealed in a sealable aluminium foil together with the oxygen absorber Ageless® Z100 (Mitsubishi) or with the absorber of oxygen and carbon dioxide Ageless® E100 (Mitsubishi) and the sample was heated at 80° C. for 72 hr. The reference sample was prepared and heated in the same way without the use of absorbers. The results of HPLC analyses are summarized in Table 4.
[0000]
TABLE 4
Lactone of Atorvastatin,
Conditions
Total Impurities, %
%
Initial
0.49
0
Reference sample
1.32
0.33
Ageless ® Z100
0.64
0.19
Ageless ® E100
0.60
0.14
Example 2
[0052] Amorphous atorvastatin (1 g) was sealed in a sealable aluminium foil together with the oxygen absorber Ageless® Z100 (Mitsubishi) or with the absorber of oxygen and carbon dioxide Ageless® E100 (Mitsubishi) and the sample was heated at 40° C. for 1.5 months. The reference sample was prepared and heated in the same way without the use of absorbers. The results of HPLC analyses are summarized in Table 5.
[0000]
TABLE 5
Lactone of Atorvastatin,
Conditions
Total Impurities, %
%
Initial
0.49
0
Reference sample
1.55
0.22
Ageless ® Z100
0.36
0
Ageless ® E100
0.46
0.06
Example 3
[0053] Tablets having the composition described in Table 6
[0000] TABLE 6 Composition of the Tablets Amount, mg calcium salt of atorvastatin 20.0 lactose monohydrate 42.0 microcrystalline cellulose 60.0 calcium carbonate 88.0 hydroxypropyl cellulose 30.0 pregelatinized corn starch 30.0 polysorbate 1.0 talc 1.5 sodium salt of crosscarmelose 6.0 calcium stearate 0.5
were coated with a usual lacquer containing hydroxypropylmethyl cellulose and sealed together with the absorption bag Ageless® Z100 (Mitsubishi) in an aluminium foil and heated at 80° C. for 72 hours. The reference sample was prepared and heated in the same way without the use of oxygen absorber. The results of HPLC analyses are summarized in Table 7.
[0000]
TABLE 7
Lactone of Atorvastatin,
Conditions
Total Impurities, %
%
Initial
0.60
0.03
Reference sample
4.21
2.58
Ageless ® Z100
1.98
1.13
Example 4
[0054] Tablets containing 20 mg of the amorphous form of calcium salt of atorvastatin having the composition described in Table 8
[0000] TABLE 8 Composition of the Tablet Amount, mg calcium salt of atorvastatin 20.0 lactose monohydrate 42.0 microcrystalline cellulose 60.0 calcium carbonate 88.0 hydroxypropyl cellulose 30.0 pregelatinized corn starch 30.0 polysorbate 1.0 talc 1.5 sodium salt of crosscarmelose 6.0 calcium stearate 0.5
were coated with a usual lacquer containing hydroxypropylmethyl cellulose and filled into a glass vial of a volume of 20 ml (reference sample). In the course of other experiments, the oxygen absorber Ageless® Z100 (Mitsubishi), or the absorber of oxygen and carbon dioxide Ageless® E100 (Mitsubishi), or the oxygen absorber Ageless® Z100 (Mitsubishi) and a desiccant were added into the vial besides the tablets. The vials were closed using a HDPE cap and subjected to 40° C. and 75% RH for 1.5 months. The arrangement of the experiment and the results of HPLC analyses are summarized in Table 9.
[0000]
TABLE 9
Lactone of Atorvastatin,
Conditions
Total Impurities, %
%
Initial
0.49
0
Reference sample
2.38
0.20
Ageless ® Z100
1.09
0.41
Ageless ® E100
1.10
0.48
Ageless ® Z100 +
0.87
0.33
desiccant
Example 5
[0055] Tablets containing 20 mg of the amorphous form of calcium salt of atorvastatin having the composition described in Table 10
[0000] TABLE 10 Composition of the Tablet Amount, mg calcium salt of atorvastatin 20.0 lactose monohydrate 49.6 microcrystalline cellulose 148.0 magnesium oxide 14.0 hydroxypropyl cellulose 28.0 polysorbate 9.0 sodium salt of crosscarmelose 9.0 magnesium stearate 1.4 silicon dioxide 1.0
were coated with a usual lacquer containing hydroxypropylmethyl cellulose, filled into a glass vial of a volume of 20 ml closed with a HDPP cap together with the absorption bag. Ageless® Z100 (Mitsubishi) and stored at 40° C. and 75% RH for 1.5 months. A reference sample was prepared in the same way without adding the oxygen absorber. A preliminary analysis found the partial pressure of oxygen after completion of the experiment. It has shown that the pressure in the vial atmosphere dropped to 0.3 kPa. The results of HPLC analyses are summarized in the following table (Table 11).
[0000]
TABLE 11
Lactone of Atorvastatin,
Conditions
Total Impurities, %
%
Initial
0.79
0
Reference sample
2.12
0
Ageless ® Z100
0.84
0
Example 6
[0056] In order to find out influence of antioxidants on stability of the dosage form, mixtures of the amorphous form of atorvastatin with a basic component and antioxidants were made. These mixtures were filled into glass vials of a volume of 20 ml, closed using a HDPE cap, and heated at 40° C. and 75% RH for 6 weeks. The composition of the said mixtures and the results of HPLC analyses are summarized in Table 12.
[0000]
TABLE 12
Total
Lactone of
Mixture
Component
Impurities,
Atorvastatin,
Number
Mixture Composition
Ratios
%
%
2
calcium salt of
1
2.03
0.05
atorvastatin
calcium carbonate
3
5
calcium salt of
1
4.04
1.12
atorvastatin
calcium carbonate
3
vitamin E
1
6
calcium salt of
1
4.53
1.58
atorvastatin
calcium carbonate
3
β-carotene
1
9
calcium salt of
1
4.71
1.29
atorvastatin
calcium carbonate
3
sodium ascorbate
1
[0057] It follows from the above experiment that the use of antioxidants, routinely used in the pharmaceutical industry, does not prevent oxidation processes in the dosage form.
Example 7
Test of Stability Under Reduced Pressure
[0058] A pure amorphous atorvastatin substance was close din a tempered box under air pressure of 5.5-7.5 kPa. The partial pressure of oxygen was estimated as 1.2-1.5 kPa
[0059] The measurement has given the following results:
[0000]
TABLE 13
Storage
Time,
Storage
Total Impurities,
Sample
days/hrs
Temperature, ° C.
%
0010903/12
23
days
20-25
0.29
0010903/15
42
days
40-42
0.35
0010903/17
55
hrs
60-65
0.33
0010903/18
160
hrs
80-82
0.37
[0060] For comparison, sample 0010903/18 was kept in a thermostat at 80° C. under normal atmospheric pressure, i.e. partial pressure of oxygen about 18 kPa for 160 hours. The total impurities then reached 1.92%.
Example 8
Packaging of the Dosage Form Under Nitrogen
[0061] Tablets containing 40 mg of the amorphous form of the calcium salt of atorvastatin having a composition proportional to that of Example 5 were packaged in an industrial packaging line adapted for packaging under nitrogen. The commercially produced blistering machine WinPack TR 130 from Italian company IMA was used for the packaging. The shaped lower sheet, containing the finished tablets, was transported into a purging chamber, into which also nitrogen under a pressure of 0.1 MPa above atmospheric at the outlet of the nitrogen source has been introduced. The flow rate of the gas in the chamber, i.e. the inlet of nitrogen and its outlet with admixture of air, was maintained at 1500 l/h. The pressure above atmospheric of nitrogen in the protective box was approximately 10 kPa. The tablets were packaged into aluminium Al/Al blisters. The finished package was subjected to a standard stability test; subjected to a load of 40° C. and 75% RH for 3 months. The partial pressure of oxygen in the aluminium package was tested after packaging and after 3 months of storage. Results of HPLC analyses are summarized in the following table.
[0062] Measurement of residual oxygen in the blister was made by a gas chromatography method with collecting the gas and with manual injection. Collection of the gas was made in three different positions in the blister.
[0000]
TABLE 14
Time of Load,
Total Impurities,
P O , kPa
Sample Designation
months
%
Position 1
Position 2
Position 3
040903
0
0.54
0.24
0.23
0.24
3
0.50
0.25
0.27
0.26
070903
0
0.76
0.20
0.19
0.20
3
0.50
0.19
0.20
0.18
Example 9
Packaging of the Dosage Form Under Reduced Pressure
[0063] Tablets containing 40 mg of the amorphous form of the calcium salt of atorvastatin having a composition proportional to that of Example 5 were closed in an experimental apparatus by welding into an Al—Al sheet (strip model) in air atmosphere under reduced pressure 1-1.4 kPa, i.e., under a partial pressure of oxygen of about 0.18-0.25 kPa, and subjected to a load of 40° C. and 75% RH for 3 months. The partial pressure of oxygen in the aluminium package was deduced from the total pressure and usual air atmosphere composition. Results of HPLC analyses are summarized in the following table.
[0000]
TABLE 15
Sample Designation
Time of Load, months
Total Impurities, %
040903
0
0.54
3
0.55
070903
0
0.76
3
0.50 | Stabilization of the pharmaceutical active solid substance atorvastatin alone or in a mixture with other solid substances embedded in a gaseous mixture is carried out in such a manner that in the surrounding gaseous mixture a partial pressure of oxygen of at most 2 kPa, preferably less than 1 kPa, more preferably less than 0.4 kPa is maintained. The corresponding partial pressure is achieved either by use of oxygen absorbers, by packaging under a pressure of 0.3-10 kPa, or by packaging under a slight overpressure of an inert gas, preferably nitrogen, the gas being introduced, by means of nozzles, into the cavities, optionally also into the space of the press roller and of the wiper station. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a division of U.S. application Ser. No. 10/210,787 filed Jul. 31, 2002, which is a continuation of International application PCT/DK01/00075 filed Feb. 1, 2001, the entire content of each of which is expressly incorporated herein by reference thereto.
TECHNICAL FIELD
[0002] The present invention relates to a new medicament for the treatment of non-insulin dependent diabetes mellitus, hypertension, metabolic syndromes and other conditions in mammals.
BACKGROUND ART
[0003] Diabetes is a common disease that has a prevalence of 2-4% in the population. Non-insulin dependent diabetes mellitus comprises about 85% of diabetes most commonly occurring at the age above 40 years. The incidence of non-insulin dependent diabetes mellitus is increasing and is at a global level expected to surpass 200 million subjects at year 2010.
[0004] Diabetes is associated with increased morbidity and a 2-4-fold increase in mortality primarily due to cardiovascular diseases and strokes.
[0005] Non-insulin dependent diabetes mellitus develops especially in subjects with insulin resistance and a cluster of cardiovascular risk factors such as obesity, hypertension and dyslipidemia, a syndrome which first recently has been recognized and is named “The metabolic syndrome” (Alberti K. G., Zimmet P. Z.; Definition, diagnosis and classification of diabetes mellitus and its complications”. Part 1: Diagnosis and classification of diabetes mellitus provisional report of a WHO consultation. Diabet. Med. July 1998; 15(7), p. 539-53).
[0006] In accordance with the WHO-definition (www.idi.org.au/whoreport.htm), a patient has metabolic syndrome if insulin resistance and/or glucose intolerance is present together with two or more of the following conditions:
reduced glucose tolerance or diabetes insulin sensivity (under hyperinsulinaemic, euglycaemic conditions corresponding to a glucose uptake below the lower quartile for the background population) increased blood pressure (≧140/90 mmHg) increased plasma triglyceride (≧1.7 mmol/l) and/or low HDL cholesterol (<0.9 mmol/l for men; <1.0 mmol/l for women) central adipositas (waist/hip ratio for men: >0.90 and for women >0.85) and/or Body Mass Index >30 kg/m 2 ) micro albuminuria (urine albumin excretion: >20 μg min −1 or albumin/creatinine ratio ≧2.0 mg/mmol.
[0013] It has become increasingly evident that the treatment should aim at simultaneously normalizing blood glucose, blood pressure, lipids and body weight to reduce the morbidity and mortality. Diet treatment, exercise and avoiding smoking are the first treatment modalities that should be started. However, it will often be necessary to add pharmacological therapy but until today no single drug that simultaneously attacks hyperglycaemia, hypertension and dyslipidemia are available for patients with metabolic syndrome. Instead, these patients may be treated with a combination of several different drugs in addition to e.g., diet. This type of treatment is difficult to adjust and administer to the patient and such treatment may result in many unwanted adverse effects which in themselves may need medical treatment.
[0014] Consequently there is a long felt need for a new and combined medicament for the treatment of metabolic syndrome thereby also preventing an increase in the number of persons developing the non-insulin dependent diabetes mellitus.
[0015] Existing oral antidiabetic medicaments to be used in such treatment include the classic insulinotropic agents sulphonylureas (Lebovitz H. E. 1997. “The oral hypoglycemic agents”. In: Ellenberg and Rifkin's Diabetes Mellitus. D. J. Porte and R. S. Sherwin, Editors: Appleton and Lange, p. 761-788). They act primarily by stimulating the sulphonylurea-receptor on the insulin producing beta-cells via closure of the K + ATP -sensitive channels. However if such an action also affects the myocytes in the heart, an increased risk of cardiac arrhytmias might be present. Also, it is well know in the art that sulphonylureas can cause severe and lifethreatening hypoglycemia, due to their continuous action as long as they are present in the blood.
[0016] Consumption of soy protein rather than animal protein has been found to lower blood cholesterol (Anderson J. W., Johnstone B. M., Cook-Newell M. E.: Meta-analysis of the effects of soy protein intake on serum lipids. N. Engl. J. Med. 1995; 333; p. 276-282). In addition to this knowledge, recent research also provides evidence that soy protein and/or isoflavones may improve endothelial function and attenuate events leading to both lesion and thrombus formation (Anderson J. W., Johnstone B. M., Cook-Newell M. E.: “Meta-analysis of the effects of soy protein intake on serum lipids”; N. Engl. J. Med. 1995; 333; p. 276-282; Potter S. M., Soy protein and cardiovascular disease: “The impact of bioactive components in soy”. Nutrition Reviews 1998;56, p. 231-235).
[0017] Several attempts to develop new antidiabetic agents and drugs for the treatment or prophylactic treatment of the syndrome not having the adverse effects mentioned above, e.g. hypoglycemia and potential harmful actions on the heart functions have been made over the years. For this purpose, plants provide a vast resource of compounds with the potential to become new antidiabetic agents.
[0018] For instance extracts of the leaves of Stevia rebaudiana Bertoni , a herbaceous member of the Compositae family, have been used for many years in the treatment of diabetes among Indians in Paraguay and Brazil (Sakaguschi M., Kan P Aspesquisas japonesas com Stevia rebaudiana (Bert) Bertoni e o estevioside. Cienc. Cultur. 34; p. 235-248,1982; Oviedo C. A., Franciani G., Moreno R., et al. “Action hipoglucemiante de la Stevia Rebaudiana Bertoni (Kaa-he-e)”. Excerpt. Med. 209, p. 92,1979; Curi R., Alvarez M., Bazotte R. B., et al. Effect of Stevia rebaudiana on glucose tolerance in normal adult humans. Braz. J. Med. Biol. Res., 19, p. 771-774, 1986; Hansson J. R., Oliveira B. H., “Stevioside and related sweet diterpenoid glycoside”. Nat. Prod. Rep. 21, p.301-309, 1993).
[0019] Also, an antihyperglycemic effect has been found in rats when supplementing the diet with dried S. rebaudiana leaves (Oviedo C. A., Franciani G., Moreno R., et al. “Action hipoglucemiante de la Stevia Rebaudiana Bertoni (Kaa-he-e)”. Excerpt. Med. 209:92, 1979). Curi et al. found a slight suppression of plasma glucose when extracts of Stevia rebaudiana leaves were taken orally during a 3-day period. Furthermore, Oviedo et al. reported that tea prepared from the leaves caused a 35% reduction in blood glucose in man.
[0020] A number of Stevia species have been examined and shown to contain labdanes, clerodanes, kaurenes and beyerenes (Hansson J. R., Oliveira B. H., “Stevioside and related sweet diterpenoid glycoside”. Nat. Prod. Rep. 21, p. 301-309, 1993). Any of these substances as well as many others unidentified substances in the leaves could be responsible for the reduction in blood glucose in man.
[0021] In the work of Malaisse W.J. et al (Malaisse W. J., Vanonderbergen A., Louchami K, Jijakli H. and Malaisse-Lagae F., “Effects of Artificial Sweeteners on Insulin Release and Cationic Fluxes in Rat Pancreatic Islets”, Cell. Signal. Vol 10, No. 10, p. 727-733, 1998) the effect of several artificial sweeteners, including stevioside, on insulin release from isolated normal pancreatic rat islets were studied. In this study it was reported that in the presence of 7 mmol/l D-glucose, stevioside in a concentration of 1.0 mmol/l caused a significant increase in insulin output. Also the control group demonstrated a significant increase in insulin output of about 16 times above the basal release value in the presence of 20 mmol/l D-glucose increase. It is therefore uncertain whether the insulin releasing effect is due to the increased glucose level or the presence of stevioside. No diabetic islet cells were studied and the skilled person within the art will know that the mechanism for stimulating normal pancreatic islet cells either not functions at its optimum or not functions at all in the diabetic pancreatic cells, and that the study provided no certain indication of the possible use of stevioside in the treatment of non-insulin dependent diabetes mellitus, hypertension and/or the metabolic syndrome.
[0022] In a Chinese study (Lin Qi-Xian, Cao Hai-Xing, Xie Dong, Li Xing-Ming, Shang Ting-Lan, Chen Ya-Sen, Ju Rui-Fen, Dong Li-Li, Wang Ye-Wen, Quian Bao-Gong, “Experiment of Extraction of Stevioside”, Chinese Journal og Pharmaceuticals 1991, No. 22, p 389-390) is indicated a method for extracting stevioside from stevioside leafs from the origin of Bingzzhou in the Hunan Province. The content of stevioside in the extract was determined using HPLC although the article is silent of the purity of the extract. The produced stevioside tablets were for no apparent reason and medical indication applied to patients in the Wuhan Second Hospital. No data on the influence of stevioside on blood glucose, insulin and/or blood pressure is revealed. It is stated that the tablets were effective to diabetes and hypertension during preliminary clinical observations. However, total lack of data on blood glucose, insulin and/or blood pressure i.e., lack of support by test results and the missing information of which types of diabetes that were treated, makes this an unsupported and unconfirmed assertion.
[0023] Any detailed information of which substance or substances in the leaves that might cause a possible anti-hyperglycemic effect has not yet been disclosed for certainty, and the mechanism of how and to which extent the plasma glucose is reduced is unknown. The above mentioned articles and studies are concerned with the initial discovery of the effects and provide no evidence of which specific component(s) in the leaves that might be the active one(s).
[0024] The effect of intravenous stevioside on the blood pressure was studied in spontaneously hypertensive rats (“The Effect of Stevioside on Blood Pressure and Plasma Catecholamines in Spontaneously Hypertensive Rats”, Paul Chan, De-Yi Xu, Ju-Chi Liu, Yi-Jen Chen, Brian Tomlinson, Wen-Pin Huang, Juei-Tang Cheng, Life Science, Vol. 63, No. 19, 1998, p. 1679-1684). The study showed that during an intravenously administration of stevioside of 200 mg/kg the hypotensive effect was at a maximum, but although reported as being significantly the fall in the systolic blood pressure was only small. Neither the heart rate nor the plasma catecholamines were significantly changed during the observation period. This study indicated that stevioside advantageously could be used for treating hypertension.
[0025] No reports of an effect on plasma glucagon level have previously been reported. Glucagon, a pancreatic islet hormone, acts as a diabetogenic hormone by increasing the hepatic glucose output thereby elevating blood glucose.
[0026] Recent studies and tests made by the present inventors have focused on especially the diterpenoid glycoside stevioside which is a major constituent found in the leaves of Stevia rebaudiana where it may occur in amounts of up to about 10% (Hansson J. R., Oliveira B. H., “Stevioside and related sweet diterpenoid glycoside”. Nat. Prod. Rep. 21, p.301-309, 1993; Bridel M., Lavielle R., Physiologie Vegetale: “Sur le principe sucre'du Kaa' he'e ( Stevia rebaudiana Bertoni ): II Les produits d'hydrolyse diastasique du stevioside, glucose et steviol”. Acad. Sci. Paris 192, p. 1123-1125, 1931; Soejarto D. D., Kinghorn A. D., Farnsworth N. R., Potential sweetening agent of plant origin. III: “Organoleptic evaluation of Stevia leaf herbarium samples for sweetness”. J. Nat. Prod. 45, p. 590-598, 1983; Mossettig E., Nes W. E. Stevioside. II: “The structure of the aglucone”; J. Org. Chem. 20, p. 884-899, 1955; Kohda H., Hasai R., Yamasaki K. et al. “New sweet diterpene glucosides from Stevia rebaudiana ”. Phytochemistry 15, p. 981-983, 1976).
[0027] Also, its aglycone, steviol, has been found to be contained in the leaves of Stevia rebaudiana as well as other sweet-tasting glycosides e.g. Steviolbioside, Rebaudioside A,B,C,D and E, and Dulcoside (Bridel M., Lavielle R., Physiologie Vegetale: “Sur le principe sucre'du Kaa' he'e ( Stevia rebaudiana Bertoni ): II Les produits d'hydrolyse diastasique du stevioside, glucose et steviol”. Acad. Sci. Paris 192, p. 1123-1125, 1931; Soejarto D. D., Kinghorn A. D., Farnsworth N. R., Potential sweetening agent of plant origin. III: “Organoleptic evaluation of Stevia leaf herbarium samples for sweetness”. J. Nat. Prod. 45, p. 590-598, 1983; Mossettig E., Nes W. E. Stevioside. II: “The structure of the aglucone”; J. Org. Chem. 20, p. 884-899, 1955; Mossettig E., Nes W. E. Stevioside. II: “The structure of the aglucone”; J. Org. Chem. 20, p. 884-899, 1955; Kohda H., Hasai R., Yamasaki K. et al. “New sweet diterpene glucosides from Stevia rebaudiana ”. Phytochemistry 15, p. 981-983, 1976).
[0028] The present inventors have already successfully proved that both stevioside and steviol have an anti-hyperglycemic, glucagonostatic and insulinotropic effect when administered intravenously to rats and a stimulatory effect on the insulin secretion from mouse islets in vitro.
[0029] No well defined, chemical stable, non-toxic, reliable and non-adverse effects alternative to the sulphonylureas for the treatment of non-insulin dependent diabetes mellitus is available today, however, and these findings have given rise to further studies and tests of analogues and derivates of these substances in order to find improved and alternative drugs for a self-regulatory treatment of diabetes, hypertension and especially metabolic syndrome in mammals, and preferably in humans.
[0030] In order to prevent sequelae or to delay the developing of a number of the above-mentioned metabolic and functional disorders in humans, there is a need it for new and beneficial dietary supplementations or new self-administrable non-prescription drugs for prophylaxis. The present invention now satisfies this need.
SUMMARY OF THE INVENTION
[0031] Accordingly, the present invention relates to a selectively responsive medicament composition comprising at least one substance including a bicyclo [3.2.1]octan in a double ring system having a basic chemical skeletal of a kaurene structure having the structural formula II:
or an analogue, derivative or metabolite thereof, wherein the substance responds only at an elevated plasma glucose concentrations. Generally, the response of the substance is initiated by a plasma glucose concentration of 6 mmol/l or larger.
[0033] Preferably, the substance is selected from the group consisting of steviol, isosteviol, glucosilsteviol, gymnemic acid, steviolbioside, stevioside Rebaudioside A, Rebaudioside B, Rebaudioside C, Rebaudioside D, Rebaudioside E and Dulcoside A, their pharmaceutically acceptable analogues or their pharmaceutically acceptable derivates. The substance can be isolated from a plant source and can be used alone or in combination with at least one soy protein alone or in combination with at least one isoflavone.
[0034] The substance and composition can be used as a dietary supplement or as a medicament for a mammal. As noted above the substance or composition is responsive in the mammal only when the mammal's plasma glucose concentrations are elevated. Thus, the medicament can be used for treating the mammal for non-insulin dependent diabetes mellitus, metabolic syndrome, to stimulate insulin production, to reduce glucagon concentrations, to suppress fasting plasma triglycerides or total cholesterol levels in the mammal, or for treating hypertension in the mammal. Preferably, the medicament is an oral medicament and is self-regulating.
[0035] The invention also relates to a method of making a selectively responsive composition which comprises associating with a carrier a bicyclo [3.2.1]octan in a double ring system having a basic chemical skeletal of a kaurene structure having the structural formula II, wherein the substance responds only at an elevated plasma glucose concentrations. The composition that is made can be used as a dietary supplement or as one of the medicaments mentioned above.
[0036] The invention also relates to various treatment methods for mammals, including treating non-insulin dependent diabetes mellitus, treating metabolic syndrome, treating hypertension, suppressing fasting plasma triglycerides, suppressing total cholesterol level, or suppressing appetite.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] The invention is further illustrated by the following examples and the accompanying drawings that are intended to illustrate preferred features and properties of the invention, wherein:
[0038] FIG. 1 shows the chemical structure of steviol, isosteviol and stevioside,
[0039] FIG. 2 a shows the effect of stevioside on blood glucose during i.v. glucose tolerance test in normal Wistar rats,
[0040] FIG. 2 b shows the effect of stevioside on blood glucose during i.v. glucose tolerance test in GK rats,
[0041] FIG. 3 a shows the effect of stevioside on glucose-induced release during i.v. glucose tolerance test in normal Wistar rats,
[0042] FIG. 3 b shows the effect of stevioside on glucose-induced release during i.v. glucose tolerance test in GK rats,
[0043] FIG. 4 a shows the effect of stevioside on glucose-stimulated insulin secretion from isolated mouse islets,
[0044] FIG. 4 b shows the effect of steviol on glucose-stimulated insulin secretion from isolated mouse islets,
[0045] FIG. 5 a shows the effect of an i.v. bolus injection of glucose on plasma glucagon levels during an intravenous glucose tolerance test in GK rats,
[0046] FIG. 5 b shows the effect of an i.v. bolus injection of glucose and stevioside on plasma glucagon levels during a glucose tolerance test in GK rats,
[0047] FIG. 6 a shows the systolic blood pressure during 6 weeks treatment of GK rats with stevioside,
[0048] FIG. 6 b shows the diastolic blood pressure in GK rats treated with stevioside.
[0049] FIG. 7 a shows the effect of 10 −3 mmol/l stevioside on the insulin secretion from isolated mouse islets in the presence of glucose ranging between 0 and 16.7 mmol/l,
[0050] FIG. 7 b shows the effect of 10 −6 mmol/l steviol on the insulin secretion from isolated mouse islets in the presence of glucose ranging between 0 and 16.7 mmol/l,
[0051] FIG. 8 a - d shows the acute effects of stevioside in type II diabetic patients, and
[0052] FIG. 9 a - g shows the effects of the action of the combination of stevioside and soy based dietary supplementation in diabetic GK-rats.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0053] Careful structural chemistry studies by the inventors have revealed that all potential substances for stimulating the insulin secretion extracted from the leaves of Stevia rebaudiana share the common unique skeletal structure of bicyclo[3.2.1]octan of the formula I:
This bicyclo[3.2.1]octan can be found in e.g. steviol, isosteviol and in stevioside. The formula I structure has also been recognised in glucosilsteviol, gymnemic acid, steviolbioside, Rebaudioside A, Rebaudioside B, Rebaudioside C, Rebaudioside D, Rebaudioside E and Dulcoside A.
[0055] All these substances also share the common structure of formula II:
which is the basic structure in kaur-16-en-18-oic acid.
[0057] These specific structures of the formula I or II are recognized in several chemical compounds, which have been shown to have a highly potent insulin stimulating effect on isolated mouse pancreatic β-cell, and these structures of formula I and II are evidently the active parts of the molecules in causing the stimulating task.
[0058] This assumption is further confirmed by the fact that tests have shown that steviol having the smallest skeletal structure stimulate the insulin secretion to a greater extent than e.g. the glycoside stevioside having a much larger skeletal structure. Also, the inventors of the present invention have succeeded in purifying the different Rebaudiosides from Stevia rebaudiana and preclinical animal studies indicate the same stimulatory effect on insulin secretion.
[0059] Consequently this indicates that other compounds including the structures of the formula I or II, such as e.g. analogues, derivates and metabolites of the compounds mentioned above, can be used alternatively.
[0060] Studies and tests on rats have disclosed that the insulin stimulating effect of these substances is dependent on the concentration of the plasma glucose.
[0061] The substances comprising the chemical structures, which includes the formula I or II, did not cause an insulin release as long as the plasma glucose concentration was below approximately 6 mmol/l. At plasma glucose concentration above 6 mmol/l, the stimulating effect of the compounds provided an elevated plasma insulin concentration resulting in an immediate suppression of plasma glucose concentration thereby keeping this at a normal level.
[0062] In addition to the above findings, the present inventors have surprisingly found that the substances comprising the chemical structures including the formula I or II also have the capabilities of reducing the glucagon concentration in the blood.
[0063] This characteristic nature and qualities of the substances make them an obvious choice as a component in a medicament for the treatment of especially non-insulin dependent diabetes mellitus (NIDDM).
[0064] The finding that e.g. intravenously administered stevioside inhibited blood glucose responses to intravenous glucose in NIDDM rats (GK rats) but not in normal rats supports this fact. This finding is new and surprisingly has neither been expected nor demonstrated in earlier studies that have only been concerned with normal pancreatic islet cells.
[0065] As a further example of the unique action of the substances according to the invention, stevioside infusion at normal blood glucose did not cause any hypoglycemia irrespective of it being given as a bolus or at a constant intravenous infusion.
[0066] Due to the insulin secretory stimulating effect induced by a slightly elevated plasma glucose concentration, the simultaneous plasma glucagon reducing effect and the inhibited blood glucose response, these substances are able to control, regulate and adjust the plasma glucose concentration of a NIDDM patient to a normal level.
[0067] As a consequence of the glucose-dependency the substances only act when needed, e.g. after the patient has increased blood glucose after having eaten. In NIDDM patients treated with medicaments including these substances hypoglycemia will not occur and hypoglycemia will be counteracted.
[0068] Therefore, the substances provide a self-regulatory system responding only at elevated plasma glucose concentration.
[0069] The substances are preferably used in medicaments for oral medication. When taken orally, the glycosylated substances can be partially metabolised but the basic skeletal structure of the formula I or II will not be changed and the different characteristic effects mentioned above will be preserved.
[0070] The treatment with a medicament including these substances provides an attractive alternative to different types of drugs available and presently used today for the treatment of NIDDM, such drugs being drugs for stimulating the insulin secretion (sulphonylureas or repaglinide), drugs for improving the insulin sensivity (biguanides and thiazolidinediones) or drugs for retarding gastrointestinal carbohydrate absorption (α-glucosidase inhibitors).
[0071] The potential of these new substances has for the first time also been tested in human NIDDM studies and the beneficial and advantageously combined multiple effects in humans of a single substance according to the invention has been demonstrated and will be further described in the examples.
[0072] The above-mentioned human tests have been conducted by orally administrating the substances, but within the scope of the invention the substances can optionally be used in the preparation of medicaments for intravenous, subcutaneous or intramuscular medication.
[0073] The substances further bring along the blood pressure reducing effect. In long-term experiments stevioside acutely suppresses blood pressure in diabetic rat. This important discovery is of the benefit to the diabetic patients that have developed hypertension in relation to or besides their disease.
[0074] When at least one of the substances according to the invention is combined in a medicament also comprising at least one soy protein alone or in combination with at least one isoflavone, it is possible to manufacture a combined preparation of a drug for the treatment of patients with the metabolic syndrome in accordance with the previously definition. Such a medicament may advantageously be used in prophylactic treatment of patient in a risk group. For example, a slow-release drug on the basis composition mentioned above provides a convenient treatment for the patient with the metabolic syndrome.
[0075] The inventors of the present invention have demonstrated that the combination of the substances according to the invention and at least one soy protein have a new unexpected and surprisingly synergistic effect surpassing the additive effect of the single components of the medicament thereby providing a completely new and very important medicament for therapeutic or prophylactic treatment of the metabolic syndrome.
[0076] The present inventors have used the combination of the substances according to the invention and at least one soy protein as a dietary supplementation in human studies. The test results significantly proved, as will be seen in the following examples, that such combination has a beneficial impact on cardiovascular risk markers in type II diabetic subjects.
[0077] Stevioside at a dose as high as 15 g/kg body weight was not lethal to either mice, rats or hamsters (Toskulkao C., Chaturat L., Temcharoen P., Glinsukon T. “Acute toxicity of stevioside, a natural sweetener, and its metabolite, steviol, in several animal species”. Drug Chem. Toxicol. February-May 1997; 20(1-2), p. 31-44). In rats and mice, LD 50 values of steviol were higher than 15 g/kg body weight while the LD 50 for hamsters were 5-6 g/kg body weight. The latter was accompanied with degeneration of the proximal tubular cells, which correlated to increases in blood urea nitrogen and creatinine. Stevioside is excreted by the urine (Melis M. S. “Renal excretion of stevioside in rats”. J. Nat. Prod. May 1992; 55(5), p. 688-90) and is not metabolised in the isolated perfused rat liver (Ishii-Iwamoto E. L., Bracht A. “Stevioside is not metabolised in the isolated perfused rat liver”. Res. Commun. Mol. Pathol. Pharmacol. February 1995; 87(2), p. 167-75).
[0078] Stevioside and steviol showed no mutagenic effect on a number of Salmonella typhimurium strains (Klongpanichpak S., Temcharoen P., Toskulkao C., Apibal S., Glinsukon T. “Lack of mutagenicity of stevioside and steviol in Salmonella typhimurium TA 98 and TA 100”. J. Med. Assoc. Thai September 1997; 80 Suppl. 1, p. 121-128; Suttajit M., Vinitketkaumnuen U., Meevatee U., Buddhasukh D. “Mutagenicity and human chromosomal effect of stevioside, a sweetener from Stevia rebaudiana Bertoni”. Environ Health Perspect October 1993; 101 Suppl. 3, p. 53-56). In another study, it was confirmed that stevioside was not mutagenic whereas steviol, however, produced dose-related positive responses in some mutagenicity test (Matsui M., Matsui K., Kawasaki Y., Oda Y., Noguchi T., Kitagawa Y., Sawada M., Hayashi M., Nohmi T., Yoshihira K., Ishidate M. Jr., Sofuni T. “Evaluation of the genotoxicity of stevioside and steviol using six in vitro and one in vivo mutagenicity assays”. Mutagenesis November 1996; 11(6), p. 573-579).
[0079] Stevioside is not carcinogenic in F344 rats (Toyoda K., Matsui H., Shoda T., Uneyama C., Takada K., Takahashi M. “Assessment of the carcinogenicity of stevioside in F344 rats”. Food Chem. Toxicol. June 1997; 35(6), p. 597-603). Doses as high as 2.5 g/kg body weight/day had no effect on growth or reproduction in hamsters (Yodyingyuad V., Bunyawong S. “Effect of stevioside on growth and reproduction”. Hum. Reprod. January 1991; 6(1), p. 158-165).
[0080] To the knowledge of the inventors, no observations or reports showing potential toxic effects in humans have been published.
[0081] It will be recognized by the skilled artisan that rearranged structures of the formula II are within the scope of the invention, and such rearrangements might occur naturally in the gastro intestinal tract. As example can be mentioned that rearrangement may occur at the C16 forming a double bond to the C15 and thereby leaving a single bond open for substitution at position 17. A COOH group at position 18 is open for a number of reactions such as reaction with alcohol, as well as a number of substituents can be provided at any point of the formula II structure. Also, other substituents such as e.g. saccharides, at the various C-atoms and the structures may be anticipated.
EXAMPLES
[0082] In the following examples, the type II diabetic Goto-Kakizaki (GK) rats originated from Takeda Chemical Ind., Tokyo, Japan and were bred locally.
[0083] The normal Wistar rats and the NMRI mice were available from Bomholtg{dot over (a)}rd Breeding and Research Centre Ltd., Ry, Denmark.
[0084] The rats had a weight of 300-350 g and the mice a weight of 22-25 g. The animals were kept on a standard pellet diet and tap water ad libi tum.
[0085] The stevioside is obtained from the Japanese company WAKO-TriCHEM.
[0086] The abbreviation IAUC means Incremental Area Under the Curve (above basal).
Example 1
[0087] As examples of the effects of a compound including the chemical formulas II, stevioside was tested on normal Wistar rats and on GK rats. 2.0 g glucose/kg body weight and 0.2 g stevioside/kg body weight were dissolved in 0.9% saline and infused intravenously. The plasma glucose and insulin levels were measured over a period of 2 hours.
[0088] The results are shown in FIGS. 2 a , 2 b , 3 a and 3 b , were the O-O series (n=6 for Wistar and n=14 for GK) illustrate glucose infused alone and the {circle over (2)}-{circle over (2)} series (n=6 for Wistar and n=12 for GK) illustrate the combined glucose and stevioside infusion. Data are given as mean±SEM.
[0089] After administration of the glucose load, plasma glucose raised immediately and plasma insulin raised abruptly. When stevioside was added together with the glucose, a diminished glucose response was found in the GK-rat and a significant decrease was observed already after 30 min. In the GK rat, stevioside caused a pronounced increase in the insulin response compared to the Wistar rat. The stevioside-induced insulin response was delayed and increased throughout the whole test. The insulin response was monophasic.
[0090] This discovery of stevioside having a blood glucose reducing effect in the type II diabetic rat indicates that stevioside and compounds having a similar chemical structure can be used in a medicament for the treatment of NIDDM in man.
Example 2
[0091] Islet from 6-10 NMRI mice were isolated and incubated in the presence of 16.7 mmol/l and 10 −9 -10 −3 mol/l stevioside or 10 −9 -10 −3 mol/l steviol.
[0092] The results of these tests are illustrated in FIGS. 4 a and 4 b where each column represents mean±SEM from 24 incubations of single islets. Black bars in FIG. 4 a indicate that stevioside is present and hatched bars indicate that stevioside is absent.
[0093] Black bars in FIG. 4 b indicate that steviol is present and hatched bars indicate that steviol is absent.
[0094] The figures show that stevioside and steviol are capable of potentiating glucose-stimulated insulin secretion. Further tests confirmed that a stimulatory effect was found already at a very low concentration (above 0.1 nM).
Example 3
[0095] During a glucose tolerance test, an intravenous bolus of stevioside of 0.2 g/kg body weight was injected in GK rats (the {circle over (2)}-{circle over (2)} serie (n=6)). GK rats receiving 0.9% saline intravenously served as controls (the O-O serie (n=6)). Glucose 2.0 g/kg body weight was administered as a bolus at timepoint 0 min. The plasma glucagon responses are shown as mean±SEM in FIGS. 5 a (control) and 5 b (GK). The plasma glucagon was suppressed in the stevioside treated GK rat.
Example 4
[0096] GK rats were treated with stevioside 0.025 g/kg body weight/24 h for 6 weeks. Stevioside was administered in the drinking water. GK rats receiving drinking water with 0.111 g D-glucose/kg body weight/24 h served as controls. Systolic ( FIG. 6 a , control: O-O series, stevioside-treated: {circle over (2)}-{circle over (2)} series) and diastolic ( FIG. 6 b , control: O-O series, stevioside-treated: {circle over (2)}-{circle over (2)} series) blood pressures were measured on the tail.
[0097] The figures show a 10-15% decrease in the blood pressure detectable after 2 weeks of treatment and the effect hereafter was stable and consistent during the study period.
Example 5
[0098] The influence of the maximal stimulatory doses of 10 −3 mol/l stevioside and 10 −6 mol/l steviol was studied in NMRI mouse islets over a range between 0 and 16.7 mmol/l glucose. Both stevioside ( FIG. 7 a ) and steviol ( FIG. 7 b ) potentiated insulin secretion at and above 8.3 mmol/l and indicated that the initiating level for stimulating insulin secretion was between 3.3 mmol/l and 8.3 mmol/l of glucose. Black bars in FIG. 7 a indicate that stevioside is present and hatched bars indicate that stevioside is absent. Black bars in FIG. 7 b indicate that steviol is present and hatched bars indicate that steviol is absent.
Example 6
[0099] Twenty type II diabetic patients (6 female/14 males) with a mean age of 63.6±7.5 years participated in a controlled randomised double blind crossover trial. They were supplemented for 6 weeks with soy protein for (50 g/day) with high levels of isoflavones (minimum 165 mg/day) and cotyledon fibers (20 g/day) or placebo (casein 50 g/day) and cellulose (20 g/day) separated by a 3 week wash-out period.
[0100] This dietary supplement significantly reduced LDL-Cholesterol by 10% (p<0.05), LDL/HDL ratio by 12% (p<0.05), Apo B-100 by 30% (p<0.01), triglycerides by 22% (p<0.05) and homocystein by 14% (p<0.01). No change was observed in HDL-Cholesterol, Factor VIIc, von Willebrandt factor, fibrinogen, PAI-1, HbAlc or 24 hour blood pressure.
[0101] The results indicate beneficial effects of dietary supplementation with soy protein on cardiovascular risk markers in type II diabetic subjects. The improvement is also seen in individuals with near-normal lipid values. Ingestion of soy product has been shown to further improve the effectiveness of low-fat diets in non-diabetic subjects and the dietary supplementation in type II diabetic patients may provide an acceptable and effective option for blood lipid control, thereby postponing or even preventing drug therapy.
Example 7
[0102] Twelve type II diabetic patients (4 female/8 males) with a mean age of 65.8±1.6 years, a diabetes duration of 6.0±1.3 years, a mean body mass index of 28.5±1.0, and a mean glycated hemoglobin HbAlc of 7.4±0.4 percent were included in the study.
[0103] The experiment was an acute, paired, cross-over study in which two test meals were served during the experiments (A: Standard meal supplemented with 1 g of stevioside given orally; B: Standard meal given together with 1 g of gelatine (placebo) given orally. The total energy content of the test meals was 1725 kJ ( protein 16 E %, fat 30 E %, carbohydrate 54 E % ).
[0104] Blood samples were drawn from an antecubital vein 30 minutes before and 240 minutes after ingestion of the test meal. The arterial blood pressure was continuously monitored during the experiment. Students paired t-test was used for comparing the effects of stevioside with placebo on the parameters measured. Data are given as mean±SEM.
[0105] Stevioside reduced the postprandial blood glucose response by 18±5% (p<0.004) compared to placebo (absolute IAUC 638±55 vs. 522±64 mmol/l×240 min; p<0.02) as seen in FIG. 8 a . Stevioside tended to stimulate the insulin response in type II diabetic patients (enhance the area under the insulin response curve (IAUC)), however the difference did not reach statistical significance (p=0.09) ( FIG. 8 b ).
[0106] Stevioside significantly reduced the postprandial glucagon levels compared to placebo (348±46 vs. 281±33; p=0.02) ( FIG. 8 c ).
[0107] Stevioside significantly reduced the postprandial glucagon like peptide-1 (GLP-1) levels compared to placebo (2208±253 vs. 1529±296; p<0.045) ( FIG. 8 d ).
Example 8
[0108] Four test diets (A: Standard carbohydrate rich laboratory animal diet (Altromin); n=12 (Alt). B: Altromin supplemented with stevioside (Altromin+Stevioside); n=12; (Alt+Ste). C: Soy plus 20% Altromin; n=12; (Soy). D: Soy plus 20% Altromin plus stevioside; n=12; (Soy+Ste)) were administered for four weeks to four groups of adult rats. Each experimental group consisted of twelve female Goto-Kakizaki with an age of 9 weeks. The rats received the stevioside (0.025 g/kg body weight/day) with the drinking water. By the end of the third experimental week intra-arterial catheters were implanted into the carotid artery thereby enabling blood sampling during a 240 minutes glucose-tolerance test which was carried out by the end of the experiment at week 4. Blood samples were drawn after a bolus infusion of 2.0 g D-glucose/kg body weight. Plasma concentrations of glucose, insulin, and glucagon were measured during the glucose tolerance test. Immediately before the glucose tolerance test fasting levels of triglycerides and cholesterol were determined. Concomitantly, the systolic blood pressure was measured using a tail cuff.
[heading-0109] Effects on Plasma-Glucose:
[0110] As seen at FIG. 8 and in Table I below stevioside reduced the incremental area (IAUC) under the glucose response curve during the glucose tolerance testing both in the Altromin (p<0.05) and in the soy+20% Altromin group (Soy) (p<0.001). The relative effect of stevioside was more pronounced in the group receiving soy+20% Altromin group compared to the group receiving Altromin. The combination of soy and stevioside synergistically reduced the area under the glucose response curve compared to the Altromin group (p<0.0001) ( FIG. 9 a .).
[0111] (Plasma glucose was measured using MPR 3, 166 391, Glucose/GOD-PAP Method from Boehringer Mannheim)
[heading-0112] Effects on Plasma Insulin:
[0113] The group receiving soy+stevioside (Soy+Ste) has reduced incremental area under the insulin response curve compared to the Altromin+stevioside group (Alt+Ste) as seen in FIG. 9 and in Table I below. Considering the concomitant blood glucose responses this indicates that soy increases the insulin sensitivity. Stevioside did not alter the insulin responses in the Altromin and soy diets when studying the total response curve from 0 to 240 minutes. However, in both groups supplementation of the diets with stevioside significantly improved the first phase insulin responses—which is subdued as a characteristic feature of type II diabetes. The combination of soy+stevioside synergistically improved the first phase insulin response (p<0.05) ( FIG. 9 b ).
[0114] (Plasma insulin was measured using Sensitive Rat Insulin RIA, Cat #SRI-13K from Linco)
[heading-0115] Effects on Plasma Glucagon:
[0116] Stevioside significantly reduced the area under the plasma-glucagon response curve during the glucose tolerance test in both the groups receiving Altromin (p<0.003) and soy (p<0.01) (see FIG. 9 c and Table I below).
[0117] (Plasma glucagon was measured using Glucagon RIA, Cat #GL-32K from Linco)
[heading-0118] Effects on Blood Pressure:
[0119] A marked significant suppression of the systolic blood pressure (p<0.05) (Table I) is elicited by stevioside in combination with either Altromin (Δ=−28 mmHg) or soy (Δ=−21 mmHg) as depicted in FIG. 9 d.
[0120] (Blood pressure was measured using TSE Non-Invasive Blood Pressure Monitoring System from Technical Scientific Equipment GmbH)
[heading-0121] Effects on Body Weight:
[0122] The initial weights in the four groups did not differ ( FIG. 5 ). Apparently the combination of soy and stevioside prevented weight gain as seen in FIG. 9 e.
[heading-0123] Effects on Triglyceride and Cholesterol:
[0124] Stevioside causes a significant suppression of the fasting triglyceride levels in combination with either Altromin (p<0.05) or soy (p<0.02) (Table I). Soy significantly reduced the fasting triglyceride levels with or without supplementation of stevioside (p<0.05 and p<0.002, respectively) (Table I). Stevioside given in combination with soy synergistically reduced the fasting total cholesterol levels compared to diets containing Altromin alone (p<0.0001). Soy alone also reduced the total cholesterol levels compared to Altromin alone (p<0.002) ( FIG. 9 f . and FIG. 9 g ) (Table I).
[0125] (Plasma cholesterol was measured GOD-PAP from Roche and triglycerides was measured using GHOD-PAP from Roche)
[0126] Stevioside exerts beneficial effects in type II diabetes i.e. reduces blood glucose, suppresses glucagon and improve first phase insulin secretion. The results also indicates that soy improves insulin sensitivity, a characteristic feature of the metabolic syndrome. Stevioside exerts a pronounced blood pressure reduction both with as well as without the presence of soy. The combination of stevioside and soy has a synergistic suppressive effect on blood glucose levels, enhances first phase insulin secretion, suppresses fasting plasma triglycerides and total cholesterol and the combination of soy and stevioside seems to prevent weight gain. The combination of stevioside and soy appears to possess the potential of an effective treatment of a number of the characteristic features of the metabolic syndrome i.e. type II diabetes, hypertension, dyslipidemia and obesity.
TABLE I IAUC IAUC IAUC p-insulin p-insulin IAUC Change in blood p-glucose (ng/ml × 240 (ng/ml × 30 p-glucagon (pg/ pressure (mmHg) Triglycerides Cholesterol Group (mM × 240 min) min) min) ml × 240 min) From week 0 to 4 (mM) (mM) Altromin 991 ± 96 317 ± 55 11 ± 4 21918 ± 1467 5 ± 4 0.72 ± 0.10 2.51 ± 007 Altromin + 757 ± 53 375 ± 42 19 ± 4 17023 ± 1449 −23 ± 6 0.50 ± 0.04 2.28 ± 0.18 Stevioside Soy + 20% Altromin 820 ± 75 218 ± 22 9 ± 2 26200 ± 2410 8 ± 3 0.49 ± 0.04 2.13 ± 0.08 Soy + 20% Altromin + 439 ± 56 248 ± 27 24 ± 5 17229 ± 1819 −13 ± 5 0.37 ± 0.02 1.84 ± 0.06 Stevioside
Table I: Areas under the p-glucose, -insulin and -glucagon response curves during the glucose tolerance test in the four experimental groups. Change in systolic blood pressure at start and at end of the study period. Fasting plasma-triglyceride and -total cholesterol concentrations by the end of the study. | A substance including the chemical structures of bicyclo [3.2.1]octan or the chemical structures of kaurene for the use in a dietary supplementation or as a constituent in a medicament for the treatment of non-insulin dependent diabetes mellitus, hypertension and/or the metabolic syndrome. The unique chemical structures of bicyclo [3.2.1]octan alone or in a kaurene structure provides the substances, such as e.g. steviol, isosteviol and stevioside with the capability of enhancing or potentiating the secretion of insulin in a plasma glucose dependent manner. The substances including these unique chemical structures also have the capability of reducing the glucagon concentration in the blood and/or lowering the blood pressure thereby providing a self-regulatory treatment system for non-insulin dependent diabetes mellitus and/or hypertension. In a combination drug which also comprise a soy protein, and/or soy fiber and/or at least one isoflavone these substances act synergistically and such combination drugs are highly useful both prophylacticly or directly in the treatment of e.g. the metabolic syndrome and obesity and has due to the self-regulatory effect a widespread applicability as a dietary supplementation. | 2 |
This application claims priority to U.S. Provisional Patent Application Ser. No. 60/341,123, filed Dec. 13, 2001.
BACKGROUND OF THE INVENTION
The present invention relates to safety systems and more particularly to capacitive occupancy detection devices. Occupant detection devices can be used to enable or disable a safety restraint device, such as an airbag, or to determine how many occupants are present in a vehicle or a room. These devices can be used to detect the absence of an occupant in the passenger seat of a vehicle, and thereby disable the deployment of the passenger's airbag. The number of occupants in a vehicle may also be monitored prior to an accident in order to provide a telematic unit, such as Onstar®, with an occupant count in order to dispatch an adequate amount of emergency response. Having an accurate occupant count prior to an accident can also help emergency response personnel to determine if one or several of the occupants may have been ejected from the vehicle during the collision. In the transportation industry, occupant presence detection devices can provide a quickly count of the number of passengers in a plane, train or bus. They can also show which seats are occupied and which are not. This can also apply to theaters or halls where it is desirable to know how many occupants are present and where newly arriving customers can find empty seats.
Various technologies have been proposed to sense the presence of an occupant in a vehicle. Early detection apparatus utilized one or more mechanical switches, which are actuated by the weight of the body upon the seat. Some systems use infrared or ultrasonic transmitters and receivers, which generate signals that are reflected off of the occupant and then received and processed. Capacitive sensors have also been used as a means of detecting the presence of an occupant.
Other capacitance-based systems exist that consist of only one electrode mounted between the seat foam and the seat coverings. These systems also rely on the occupant adding capacitance to the system, and thus causing a change in the voltage, current, or phase of the oscillator signal, which can be detected. However, many of these devices, which claim to be inexpensive, use circuitry that is far more complex than the circuitry of the device described herein. Some or these devices, such as the device described in U.S. Pat. No. 6,161,070, require precision power supplies and amplitude control of the waveform generated by their oscillators. They may require precision components and may only function over a small range of supply voltages. In addition, in order to provide better noise rejection, these devices must have additional circuitry to filter out noise. This adds a great deal of cost and complexity to these devices in comparison with this invention.
Furthermore, some devices, such as the device described in U.S. Pat. No. 4,796,013, cannot accurately detect whether the electrode is disconnected or damaged and will determine this situation to be an empty seat regardless of whether an occupant is present or not. This is because a disconnected electrode reduces the capacitance of the system and a capacitance below a certain threshold is assumed to mean an empty seat. This could prove to be fatal when the device is being used to provide logic that enables or disable a safety restraint device, such as an airbag.
SUMMARY OF THE INVENTION
The purpose of the present invention is to provide an occupant detection device, which avoids the use of mechanical sensing apparatuses, and is less expensive and more reliable than existing capacitive based occupant sensing systems. The present invention includes a single conductive electrode which, in conjunction with its surroundings, forms a capacitor which is a part of a bridge circuit. The device includes an oscillator for continuous excitation of the bridge, a differential amplifier to determine if the bridge is unbalanced, an AC-DC converter circuit to convert the output of the amplifier to a DC signal, and a threshold circuit for triggering the output signal once the output of the AC-DC converter exceeds a predetermined threshold.
One arm of the bridge circuit is used as a reference for the arm of the bridge that contains the electrode. Each arm of the bridge is essentially a low-pass filter. The reference arm of the bridge is tuned to have the same filter characteristics as the arm that contains the electrode. The change in attenuation and phase of the waveform passing through the electrode arm of the bridge is measured with respect to the reference arm of the bridge. Since both arms of the bridge are receiving the same waveform, it does not matter if the amplitude varies slightly.
If an occupant is present on the seat, additional capacitance from the human body is introduced into the bridge via the electrode. This creates differences in the voltage and phase of the waveform in each arm of the bridge circuit. These changes are then amplified by a differential amplifier. The signal is then converted to a DC voltage that, when above a predetermined threshold, causes the device to output a signal that indicates the presence of an occupant. Using a bridge configuration and a differential amplifier allows the circuit to be operated over a wide range of supply voltages. It also reduces the need for high precision components and the need to regulate the amplitude of the waveform produced by the oscillator.
BRIEF DESCRIPTION OF THE DRAWINGS
Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
FIG. 1 illustrates an occupant detection system according to the present invention, as installed in a vehicle.
FIG. 2 shows the block diagram of the basic detection circuit.
FIG. 2 a shows the basic model for a capacitor.
FIG. 2 b shows the sources of capacitance when the seat is empty.
FIG. 2 c shows the sources of capacitance when the seat is occupied.
FIG. 3 shows the output of the differential amplifier before and after the AC-DC conversion when the seat is empty, occupied and when the electrode is disconnected or damaged.
FIG. 4 is a graph of the output voltage of the AC-DC converter versus the capacitance detected on the electrode for an empty seat, an occupied seat and a disconnected or damaged electrode.
FIG. 5 shows the block diagram for the detection circuit of the second embodiment of the invention.
FIGS. 6 a and 6 b show the occupant presence detection device with child-seat detection in accordance with the third embodiment of the invention. FIG. 6 a shows the TOP and SIDE view of the electrode. FIG. 6 b shows the block diagram of the basic detection circuit.
FIG. 6C shows a child-seat on top of the electrode according to the third embodiment of the invention.
FIG. 7 shows an alternate detection circuit.
FIG. 8 is a graph of the output frequency of the detection circuit of FIG. 7 as a function of capacitance.
FIG. 9 shows one way for protecting the electrode in the prior figures from false detection due to moisture.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates an occupant presence detection system 10 for determining the presence of an occupant 12 in a vehicle seat 14 . For illustrative purposes, the occupant presence detection system 10 of the present invention will be described as it is used in a vehicle seat 14 installed in a vehicle passenger compartment 16 in conjunction with an occupant safety system including an automatic safety restraint, such as an airbag 18 ; however, the occupant presence detection system 10 could be used in other applications to determine the presence of an occupant. Although a steering wheel mounted airbag 18 is illustrated as an example, it should also be understood that the present invention is also useful for side airbags, seatbelt pre-tensioners, deployable knee bolsters, and any other automatic safety restraint actuators. A crash detector 19 , such as a crash sensor of any known type, is used to determine the occurrence of a vehicle crash and to determine the crash severity. A telematic unit 20 of the type described above may also be provided.
The system 10 includes a control unit 24 generally comprising a CPU 31 having memory 32 . The CPU 31 is suitably programmed to perform the functions described herein and a person of ordinary skill in the art could program the CPU 31 accordingly and supply any additional hardware not shown but needed to implement the present invention based upon the description herein. In operation, the control unit 24 communicates with the crash detector 19 to determine the occurrence and severity of a crash of the vehicle and activates an appropriate safety system, such as air bag 18 , in response.
The present invention provides a detector circuit 27 to determine the presence of the occupant 12 in the vehicle seat 14 and communicate the presence or absence of the occupant 12 in the seat 14 . As will be described in more detail, the detector circuit 27 generally includes a seat electrode 34 mounted adjacent the area to be occupied by the occupant 12 , in this case in the vehicle seat 14 . The seat electrode 34 comprises a sheet of non-conductive fabric 36 with a pattern sewn on using special conductive thread 38 , such as Dupont Araconâ. The electrode 34 can be made of any conductive material and can be of any size or shape. It does not have to form the same pattern as the conductive thread 38 shown and it could be made from a continuous sheet of conductive material; however, conductive thread 38 is preferred since it can be sewn directly into the non-conductive fabric 36 , which could be the seat 14 cover, or a layer of material below the seat cover. Although a crown-shaped pattern for the thread 38 is shown in FIG. 1 , the pattern of the thread 38 does not have to be the same as the crown shaped pattern depicted in FIG. 1 . The detection circuit can be tuned for any pattern that covers the desired sensing area. The larger the area covered by the electrode, the more sensitive it will be for all occupant seating positions. Although only one detector circuit 27 is shown, it is preferred that a detector circuit 27 , or at least a different seat electrode 34 , would be provided for each available seat in the vehicle. Alternatively, the electrode 34 could be solid, flat electrode instead of the conductive thread 38 .
This invention uses the detection circuit 27 , shown in FIG. 2 , which can use a single differential amplifier 40 and AC-DC conversion circuit 42 to detect changes in the voltage, current and phase of the waveform produce by the oscillator 44 . A single threshold circuit 46 determines if these changes indicate the presence of an occupant. The two inputs to the differential amplifier 40 are each connected to one of a pair of arms in a bridge circuit 48 . One arm of the bridge circuit 48 is used as a reference arm, including R ref , C ref and reference wire 52 . The other arm of the bridge circuit 48 contains the electrode 34 and R occ . An oscillator 50 is connected to both arms. Each arm of the bridge circuit 48 is essentially a low-pass filter. The reference arm of the bridge circuit 48 is tuned to have the same filter characteristics as the arm that contains the electrode 34 . The change in attenuation and phase of the waveform passing through the electrode arm of the bridge circuit 48 is measured with respect to the reference arm of the bridge circuit 48 . Since both arms of the bridge circuit 48 are receiving the same waveform, it does not matter if the amplitude varies slightly.
Noise rejection is accomplished by providing a second wire 52 that is connected to the reference arm of the bridge circuit 48 and twisted together with a wire 54 that connects the electrode 34 to the bridge circuit 48 . Since both wires 52 , 54 pick up the same noise, the noise is not amplified because it is common to both arms of the bridge circuit 48 and both inputs to the differential amplifier 40 . All thresholds and signals in the device vary in proportion to the power supply voltage. As such, the device is tolerant to sudden changes in the supply voltage and will function over a wide range of supply voltages. Wire 54 may also be a coaxial cable in order to avoid noise and interference problems.
The virtual capacitor C v , created by electrode 34 is connected in series with the resistor R occ to form one arm of the bridge circuit 48 . These are connected in parallel with the resistor R ref and the capacitor C ref which form the reference arm of the bridge circuit 48 . Each arm of the bridge circuit 48 is essentially a low pass filter. The product RC determines the characteristic of each low pass filter. When RC changes, the phase and the amplitude of output of the filter changes. The RC value for the reference low pass filter is chosen so the bridge circuit 48 is balanced when the seat is empty. When there is an occupant present in the seat, C v increases and the RC value changes in only one arm of the bridge circuit 48 . The outputs of the two low pass filters are no longer the same. The unbalance in the bridge circuit 48 is detected by amplifying the differences between the two signals. The amplified signal is an AC signal representing the voltage difference between the two filters multiplied by the gain of the amplifier. The difference in phase shifts between the two filters are detected because the leading and lagging portion of each waveform overlap each other causing a voltage differences between theses signals. The AC signal is then passed through the AC-DC conversion circuit 42 to produce a DC signal that is then compared to a predetermined threshold in threshold detection circuit 46 to determine if an occupant is present or if a failure has occurred that causes the output to default to occupant present.
Both an increase and decrease in capacitance can cause a debalance in the bridge circuit 48 . An increase in capacitance indicates the presence of an occupant, while a decrease in capacitance indicates a disconnected or damaged electrode 34 . Both situations will cause the output to indicate “occupied.” This means that if the electrode 34 is damaged, the device will fail in a safe mode that will allow the safety restraints system to revert to a first generation configuration where the safety restraints device is always deployed in the event of a serious accident. However, other embodiments of the invention described below provide detection of these faults allowing for alternative measures to be taken in the event of a device failure.
FIG. 2 a shows the basic model of a capacitor. The formula for a parallel capacitor is, C=∈A/d, where C is capacitance, ∈ is the permittivity, A is area of the plates and d is the distance between the plates. The values of these variables determine the capacitance of the capacitor. Therefore, a change in one or more of these variables causes a change in capacitance. The permittivity and the area of the plates are proportional to the capacitance while the distance between the plates is inversely proportional to the capacitance. This means that an increase in permittivity or area causes an increase in capacitance while a decrease in permittivity or area causes a decrease in capacitance. The opposite is true for the distance between the plates. An increase in the distance between the plates causes a decrease in capacitance while a decrease in the distance between the plates causes an increase in capacitance. The electrode acts as one plate, while the surrounding environment acts as the second plate.
FIG. 2 b shows a model of the sources of capacitance in a typical vehicle. The value C v is the sum of virtual capacitors formed between the electrode 34 and the portion of the chassis beneath the seat (C v1 ), the seat frame (C v2 ), the roof (C v3 ) and the floor pan (C v4 ). However, the invention does not require a grounded frame to function, any type of structure including walls, ceilings, floors and the earth beneath one's feet can act as the second plate of the capacitor. The capacitance of the virtual capacitor C v changes depending on the medium between the electrode 34 and its surroundings.
FIG. 2 c shows the same model with an occupant present. Assuming that we have a capacitor with constant area and distance between the plates, then the capacitance will be altered by the medium put between the plates. When the seat is empty the medium adjacent the electrode 34 is air. Water has a higher permittivity than air and the seat foam and the human body consists of approximately 65% water. Hence, putting a human body between the electrodes and its surroundings will increase the permittivity and, in turn, will increase the capacitance between the electrode and its surroundings (C v2 , C v3 , C v4 ). The weight of the body will also cause the distance between the electrode and the portion or the chassis beneath the seat to decrease, causing an increase in the capacitance C v3 . Therefore, the capacitance of an occupied seat (C′ v ) will be larger than the capacitance of an empty seat (C v ).
FIG. 3 shows the output of the differential amplifier 40 ( FIG. 2 ) before and after AC-DC conversion by AC-DC converter 42 ( FIG. 2 ). When the seat 14 is empty, the difference between the outputs of the two low pass filters will be small and the output of the differential amplifier will be almost flat and will be centered around half-supply. Once it is converted to a DC signal it will be below the predetermined threshold V thresh and the device will output an empty signal. When an occupant is present in the seat 14 or when the electrode 34 is disconnected or damaged, the difference between the outputs of the two low pass filters will be large and the output of the differential amplifier will be a waveform centered around half-supply. Shorting the electrode 34 to the grounded chassis will also have this effect. Once the signal is converted to a DC signal, it will be above the predetermined threshold V thresh and the device will output an occupied signal.
Note that the AC signals for an occupied seat 14 and for a damaged electrode 34 are of opposite phases. This is because when an occupant is present, the capacitance C v increases causing the output signal coming from the sensing arm of the bridge circuit 48 to have a smaller peak-to-peak value than the output signal coming from the reference arm of the bridge circuit 48 . When the electrode 34 is disconnected or damaged, the capacitance C v decreases causing the output signal coming from the sensing arm of the bridge circuit 48 to have a larger peak-to-peak value than the output signal coming from the reference arm of the bridge circuit 48 . When the electrode 34 is shorted to the grounded chassis, the signal on negative input of the differential amplifier will always be much smaller than the signal on the positive input and the output of the amplifier will saturate high and will always produce a DC signal above V thresh .
FIG. 4 shows the plot of the DC output of the differential amplifier versus the value of the virtual capacitance C v for different configurations. Region B corresponds to an empty seat and at least a fairly balanced bridge circuit 48 . C bal indicates the point of the graph that corresponds to a perfectly balanced bridge circuit 48 . Region C of the graph corresponds to an occupied seat. Region A of the graph corresponds to a disconnected or damaged electrode 34 . Regions A and C in FIG. 4 both correspond to a debalanced bridge circuit 48 . The circuit is tuned for a given environment as follows: The position of the MINIMUM of the curve is set by the value or the components in the bridge circuit 48 R occ , R ref and C ref . These values are tuned so that the MINIMUM point on the curve occurs at the value of C v that corresponds to and empty seat (C bal ). The sensitivity of the device to changes in the virtual capacitance C v is tuned by changing the gain of the differential amplifier and the predetermined threshold value V thresh . V thresh must be situated between the MINIMUM of the curve and the saturation voltage of the differential amplifier less a diode drop.
In the second embodiment of the invention, shown in FIG. 5 , a fault detection circuit 60 is incorporated to detect the most common failure modes of a capacitance based system. These include; failure of the oscillator 50 disconnected or damaged electrode 34 , and the electrode 34 being shorted to the grounded vehicle chassis. This allows for the device reading the occupant presence detection device to take alternative actions in the event of a failure. This device utilizes the electrode 34 shown in FIG. 1 .
The fault detection circuit 60 is divided into two independent modules; an oscillator failure detection module 62 and a damaged/grounded electrode detection module 64 . The output of the oscillator 50 is coupled to an AC-DC converter 66 via the capacitor C which only allows an alternating signal to pass. Regardless of the voltage at which the oscillator 50 fails, the signal will not be passed to the AC-DC converter 66 once there is no oscillation. This will cause the DC signal to fall below a predetermined threshold as determined by threshold circuit 68 , triggering the FAULT signal to be output.
The damaged/grounded electrode detection module 64 works by measuring the voltage drop over the resistor R sense using a differential amplifier 72 and converting the resulting AC signal to DC. The voltage drop across R sense varies proportionally with the current drawn by the bridge circuit 48 . A damaged or disconnected electrode 34 will draw less current than an empty seat or occupied seat. Thus, the peak voltage across R sense will be smaller than the peak voltage across R sense when the seat is empty or occupied. A grounded electrode 34 will draw more current that an empty seat or occupied seat. Thus, the peak voltage across R sense will be larger than the peak voltage across R sense when the seat is empty or occupied. Therefore, the DC signal of the AC-DC converter 74 in the damaged/grounded electrode detection module 64 must be compared with both HI and LO thresholds by threshold detection circuit 76 to detect these faults. All thresholds and waveforms in the device vary in proportion to the power supply voltage. As such, the device is tolerant to sudden changes in the supply voltage and will function over a wide range of supply voltages.
The outputs of these modules 62 , 64 are coupled together using a wire OR circuit 78 to provide a generic FAULT signal. However, two individual signals could be output instead of one generic FAULT signal. It is also possible to provide three individual fault signals: oscillator failure, electrode damaged, and electrode grounded if that information is even desired. Implementation of these variations will be apparent to those skilled in the art and are considered to be within the scope of the invention.
In the third embodiment of the invention, shown in FIGS. 6 a and 6 b , a second capacitive sensor 80 , configured to detect pressure, is used in conjunction with the original electrode in order to detect the presence of a child-seat. FIG. 6 a shows the TOP and SIDE view of the sensor. It consists of a basic occupant sensing electrode 34 (as described above) working in conjunction with the pressure-sensing capacitive sensor 80 . The capacitive sensor 80 comprises a sensing electrode 82 , a grounded plate 84 and a compressible material 86 .
As mentioned previously, a decrease in the distance between the electrodes 82 , 84 causes an increase in capacitance. Therefore, the weight of a body, or of a child seat will cause the distance between the sensing electrode 82 and grounded electrode 84 to decrease, causing an increase in capacitance. This will be detected by the second detection circuit 90 as shown in FIG. 6 b.
The second detection circuit 90 is identical to the first, only it is configured to detect a change in pressure due to a compression force causing the material 86 between the sensing electrode 82 and the grounded electrode 84 to compress. The compressible material 86 can be made from any foam, rubber, plastic or fabric that is compressible and retains its height after being compressed. The outputs may be connected to logic circuits, such as the AND gates 90 , 92 shown (with the inverted input on the child seat presence AND gate 92 ).
FIG. 6C shows a child-seat 98 on top of the electrode according to the third embodiment of the invention. In this situation the occupant-detecting electrode 34 would not detect the child seat since it is not conductive. However, the pressure sensor 80 would detect that an object with weight above a predetermined threshold is present. This object could be something other than a child seat. In both cases, however, it would not be desirable to deploy an airbag. When the seat is empty, both outputs would indicate empty. When a seated occupant is present, both outputs would indicate a presence since an occupant is both conductive and has weight above the predetermined threshold. TABLE 1 is a summary of the operation of this embodiment.
TABLE 1
Presence
Child seat
Object in Seat
Sensor Output
Sensor Output
Empty
0
0
Seated Occupant
1
1
Child in Child seat
0
1
Of course, it is also contemplated as part of the present invention to implement the fault detection of FIG. 5 in addition to child-seat detection of FIGS. 6 a and 6 b . The fault detection circuitry shown in FIG. 5 would be connected to both bridges of the device shown in FIG. 6 b . This allows for the device reading the occupant presence detection device to take alternative actions in the event of a failure. This device would utilize the electrode shown in FIG. 6 a.
FIG. 7 shows an alternate detection circuit in which capacitance is used indirectly as the means of presence detection. The electrode 34 becomes a capacitor, C, in an oscillator circuit also including an op-amp 102 and resistor 104 . The frequency at which the oscillator functions is dependent on several parameters including the capacitance C. In an empty state (no human presence) the system will oscillate at a given frequency based on these parameters so long as they remain constant. When an occupant is present, the C value increases. If, for example an RC oscillator is used, an increase in capacitance C results in a decrease in oscillating frequency. This phenomenon can be used to determine the presence of an occupant. Other oscillator configurations may have an output in which an increase in capacitance results in an increase in frequency. It should be apparent to anyone skilled in the art that this will not change the intent of the invention.
A control unit 106 is used to measure the oscillator's frequency. The control unit 106 will compare the incoming frequency to a set threshold frequency. If the incoming frequency has crossed this threshold (meaning capacitance has decreased) the control unit will output an occupied signal. If the frequency has not crossed the threshold, the control unit will output an empty signal. This threshold must be tuned based on the application of the presence detector and the surrounding environment.
This capacitance results in an oscillating frequency of ω 1 . The control unit is tuned so that ω threshold is less than the unoccupied frequency ω 1 . In this configuration, the control unit 106 will output an “unoccupied” signal.
With an occupant in the seat, the occupied capacitance, C, (due to the presence of the occupant) is higher than the empty capacitance. If the resulting frequency is lower than the threshold frequency, the control unit will output an “occupied” signal.
In addition, the control unit 106 can monitor the rate of change of the oscillator's frequency. This allows the control unit 106 to ignore slow changes in frequency which would tend not to represent an occupant sitting on the seat or leaving the seat.
Hysteresis can also be added to the control unit 106 to eliminate flickering of the output signal when the frequency is hovering around the threshold. FIG. 8 shows that in the RC oscillator, the operating frequency of the oscillator must cross ω thresholdoccupied in order for the circuit to output an “occupied” signal. FIG. 8 shows ω thresholdoccupied is the frequency that must be crossed prior to outputting an “empty” signal. These two thresholds can be tuned in the control unit 106 . Hysteresis can also be applied to the first embodiment of this invention by tuning V threshold in the first embodiment as ω threshold is tuned in the second embodiment. When applying hysteresis to the first embodiment a similar output would be shown as in FIG. 8 with the oscillating frequency replaced by the output voltage.
FIG. 9 illustrates one possible technique for avoiding interference from moisture with the capacitance measurement by the electrode 34 . This technique is applicable to any of the embodiments described in any of the preceding Figures. An elastically deformable spacer 110 , preferably comprising foam similar to that used in seats, is positioned on top of the electrode 34 . The electrode 34 is then sealed against water by a seal 112 , such as EPDM rubber. A second spacer 114 (again, possibly foam) and a second seal 116 (again, possibly EPDM rubber) may be positioned below the electrode 34 . The spacers 110 , 114 are preferably larger than the electrode 34 on all sides, preferably by about 0.5 inches. The seals 112 , 116 may be coated with an adhesive on the side facing the spacer 110 , 114 , respectively. The seals 112 , 116 are preferably larger than the spacers 110 , 114 on all sides, preferably by about 1 inch, and thus adhere to the spacers 110 , 114 and to one another 112 , 116 at the overlapping edges. The location where the wires (not shown) exit the electrode 34 is also sealed. Adhesive may also be used between the electrode 34 and spacers 110 , 114 . The lower seal 116 may optionally include a hole 118 to permit air to escape to prevent ballooning.
The arrangement in FIG. 9 mitigates the effect of water on the seat because it requires the occupant to exert a force on the electrode assembly. If enough force is exerted on the upper seal 112 , the spacer 110 will deform and the occupant's body will approach the electrode 34 , thus changing the capacitance and the system will indicate that an occupant has been detected.
If only water is applied to the seat, there is not sufficient force to deform the spacer 110 and the spacer 110 prevents the water from approaching the electrode 34 and therefore prevents the system from falsely detecting an occupant. The arrangement of FIG. 9 could be implemented by placing the electrode 34 inside existing foam of a seat, wherein the spacers 110 and 114 would be the existing foam in the seat.
Alternatively, a moisture detector could be used in conjunction with a presence detector to notify the system when the seat is wet. When a significant amount of moisture is detected, the system could output a signal to indicate that the seat is wet and that the presence detection is currently unreliable or has been deactivated.
Again, although the present invention has been described for use in a vehicle, it would be useful in any seating application, such as those described in the Background of the Invention. Further, the present invention could also be used in non-seating applications to determine the presence of a person. It should be noted that the embodiments described above have been described for purpose of illustration and are not intended to limit the scope of the claimed invention, which is set forth in the claims. Claim terms below are intended to carry their ordinary meaning unless specifically defined otherwise in the claims. Alphanumeric identifiers on method steps are provided for ease of reference in dependent claims and are not intended to dictate a particular sequence for performance of the method steps unless otherwise indicated in the claims. | The purpose of this invention is to sense the presence of a seated occupant in a vehicle such as an automobile, plane, train or bus, or in a room or location where it is desirable to detect if seats are occupied. The occupant presence detection device consists of a single seat-mounted electrode, an oscillator circuit, a bridge circuit, a detection circuit and a circuit for processing the detected signals. The oscillator circuit excites the electrode. If an occupant is present on the seat, additional capacitance from the human body is introduced into the bridge via the electrode. This created differences in the voltage and phase of the waveform in each arm of the bridge circuit which are amplified by a differential amplifier. The signal is then converted to a DC voltage that, when above a predetermined threshold, causes the device to outputs a signal that indicates the presence of an occupant. Using a bridge configuration and a differential amplifier allows the circuit to be operated over a wide range of supply voltages. It also reduces the need for high precision components and the need to regulate the amplitude of the waveform produced by the oscillator. The net result is a capacitive occupant sensing device that is less complex and less expensive that previous capacitive occupant sensing devices, yet is tolerant of power supply fluctuations, is able to function over a wide range of operating voltage and still provides failsafe functionality. | 1 |
This is a continuation of application Ser. No. 08/057,085, filed on May 3, 1993, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image forming apparatus for forming a color image and, more particular, a projector using the same.
2. Related Background Art
A conventional image forming apparatus is exemplified by a projector shown in FIG. 1.
Light emitted from a light source 30 directly or through a reflector 5 is color-separated into red, green, and blue light components by a dichroic mirror 7 for reflecting the red light component and transmitting the green and blue light components therethrough and a dichroic mirror 8 for reflecting the blue light component and transmitting the green light component therethrough and a total reflection mirror 20. The color-separated light components pass through liquid crystal light valves 1, 2, and 3 and are synthesized through a dichroic mirror 9 for reflecting the blue light component and transmitting the red light component therethrough and a dichroic mirror 10 for reflecting the green light component and transmitting the red and blue light components therethrough. The synthesized light is projected through a projection lens 6.
A metal halide lamp having spectral characteristics in the entire visible light range, as shown in FIG. 2 is used as the light source 30.
In the conventional apparatus, a color-separating optical system is located between the light source and the liquid crystal light valves, and optical paths between the light source and the liquid crystal light valves must have predetermined lengths. Illumination light from the light source cannot be perfect telecentric light and contains convergent and divergent components. For this reason, the illumination light has a considerably large loss by divergence during propagation along the optical paths having the predetermined lengths. In addition, the color-separating optical system causes an increase in the size of the apparatus as a whole, thereby degrading portability of the apparatus.
As one method of solving these conventional problems, there may be proposed a single light valve type liquid crystal projector which has one white light source and one liquid crystal light valve having an RGB mosaic color filter. This arrangement allows formation of a projector by one liquid crystal light valve, and the color-separating optical system and the color-synthesizing optical system can be omitted, thereby realizing a very compact apparatus. However, the following problems are still posed by this apparatus.
As the color filter is generally of an absorption type, the amount of white light passing through the color filter is reduced to about 1/3. For this reason, the transmittance of the liquid crystal light valve is reduced, and hence a sufficiently bright display image cannot be obtained.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a compact image forming apparatus having a high light utilization efficiency and a high resolving power and a projector using the same.
In order to achieve the above object according to an aspect of the present invention, there is provided an image forming apparatus having a plurality of imaging means for forming color-separated images and color-synthesizing means for synthesizing the image light components from the plurality of imaging means, characterized by comprising a plurality of light sources, wherein the plurality of imaging means are illuminated with different color light components.
According to another aspect of the present invention, there is provided a projector comprising an elliptical reflector and a light source located near one focal point of the elliptical reflector and a projection lens located such that a pupil thereof is located near the other focal point of the elliptical reflector, wherein imaging means is located at a position equidistantly spaced apart from both the focal points, so that non-image light reflected by the imaging means is directed near the light source.
According to still another aspect of the present invention, there is provided a projector having a reflector of a shape having at least one focal point, a light source arranged near the focal point, imaging means for modulating light from the light source to form an image, and a mosaic color filter for color-separating the light incident on the imaging means into red, green, and blue light components in a mosaic distribution, wherein the mosaic color filer comprises an interference filter for transmitting any of the red, green, and blue light components and reflecting remaining color components, and the reflected remaining light components are directed near the light source.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view showing an arrangement of a conventional projector;
FIG. 2 is a graph showing the spectral characteristics of a white light source used in the conventional projector;
FIG. 3 is a schematic view showing an arrangement of an embodiment of the present invention;
FIG. 4 is a schematic view showing an arrangement of another embodiment of the present invention;
FIG. 5 is a graph showing the spectral characteristics of a color light source used in the embodiments of the present invention;
FIG. 6 is a schematic view showing an arrangement of still another embodiment of the present invention;
FIG. 7 is a schematic view showing an arrangement of still another embodiment of the present invention;
FIG. 8 is a schematic view showing an arrangement of still another embodiment of the present invention;
FIG. 9 is an enlarged sectional view of a liquid crystal light valve according to still another embodiment of the present invention;
FIG. 10 is a view showing an arrangement of a color filter according to still another embodiment of the present invention;
FIG. 11 is a schematic view showing an arrangement of still another embodiment of the present invention;
FIG. 12 is a schematic view showing an arrangement of still another embodiment of the present invention;
FIG. 13 is an enlarged sectional view of a liquid crystal light valve according to still another embodiment of the present invention; and
FIG. 14 is a schematic view showing still another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 3 is a schematic view showing an arrangement of an embodiment of the present invention. Light valves 1, 2, and 3 as imaging means form color images corresponding to the blue, green, and red light components, respectively. An apparatus in FIG. 3 also includes a projection lens 6, dichroic mirrors 8, 9, and 11, a total reflection mirror 20, and color light sources 31 and 32 having spectral characteristics represented by B and G+R, respectively, as shown in FIG. 5. More specifically, the light source 31 is a blue light source, and the light source 32 is a yellow light source having green and red spectra. These components of the apparatus have a layout, as shown in FIG. 3. The light source 32 may be constituted by green and red light sources which are arranged adjacent to each other.
The blue light source 31 is located immediately behind the liquid crystal light valve 1. For this reason, the length of the illumination optical path can be reduced to 1/4 or less of the conventional apparatus shown in FIG. 1. Illumination light emitted from the yellow light source 32 is color-separated into red and green light components by the dichroic mirror 8. The 10 red and green light components are radiated on the liquid crystal light valves 2 and 3, respectively. The length of the optical path can be reduced to about 1/2 the conventional apparatus shown in FIG. 1 in which light components reach the liquid crystal light valves 2 and 3 through two dichroic mirrors. The loss of the divergent illumination light can be greatly reduced, and a brighter image forming apparatus can be arranged.
Note that combinations of the color filters and a white light source may be used in place of the blue and yellow light sources described above.
After the light components pass through the liquid crystal light valves 1, 2, and 3, they are synthesized again through the total reflection mirror 20, the dichroic mirror 9 for transmitting the blue light component and reflecting the green component, and the dichroic mirror 11 for transmitting the red light component and reflecting the green and blue light components. The synthesized light is projected through the projection lens 6.
In this embodiment, if the dichroic mirrors 8 and 11 are designed to transmit the red light component and reflect the blue and green light components, the dichroic mirrors 8 and 11 can be identical to each other, thus resulting in an economical advantage. At this time, if the dichroic mirrors 8 and 11 are constituted by a single dichroic mirror, the number of optical elements and the number of positioning operations can be reduced.
Man's eye is most sensitive to the green light component among the components in the visible range. On the other hand, when light is obliquely incident on parallel flat plates, as in this embodiment, an astigmatism occurs. Judging from these two factors, it is found that the number of times of passing of the green light component through a dichroic mirror can be reduced to obtain a high resolving power. In this embodiment, since the green light component does not pass through a dichroic mirror, a display image having a high resolving power can be obtained.
FIG. 4 is a schematic view showing an arrangement of another embodiment according to the present invention. Light valves 1, 2, and 3 as imaging means form color images corresponding to the blue, green, and red light components, respectively. An apparatus in FIG. 4 also includes a projection lens 6, dichroic mirrors 8, 9, and 10, a total reflection mirror 20, and color light sources 31 and 32 having spectral characteristics represented by B and G+R, respectively, as shown in FIG. 5. More specifically, the light source 31 is a blue light source, and the light source 32 is a yellow light source having green and red spectra. These components of the apparatus have a layout, as shown in FIG. 4.
The blue light source 31 is located immediately behind the liquid crystal light valve 1. For this reason, the length of the illumination optical path can be reduced to 1/4 or less of the conventional apparatus shown in FIG. 1. Illumination light emitted from the yellow light source 32 is color-separated into red and green light components by the dichroic mirror 8. The red and green light components are radiated on the liquid crystal light valves 2 and 3, respectively. The length of the optical path can be reduced to about 1/2 the conventional apparatus shown in FIG. 1 in which light components reach the liquid crystal light valves 2 and 3 through two dichroic mirrors. The loss of the divergent illumination light can be greatly reduced, and a brighter image forming apparatus can be arranged.
After the light components pass through the liquid crystal light valves 1, 2, and 3, they are synthesized again through the total reflection mirror 20, the dichroic mirror 9 for transmitting the blue light component and reflecting the green component, and the dichroic mirror 10 for reflecting the red light component and transmitting the green and blue light components. The synthesized light is projected through the projection lens 6.
With this arrangement, the direction of a projection image can be shifted from that of the embodiment of FIG. 3 by 90°.
The white light source 30 of the conventional projector shown in FIG. 1 often comprises a metal halide lamp. Light emitted from a metal halide lamp generally has a shortage of the blue light component. In addition, when light passes through or reflected by a dichroic mirror, some light components having a wavelength of 400 nm or less are absorbed by the dichroic mirror.
When the above factors are taken into consideration, a light source for generating a blue light component which tends to be short is independently prepared, and a light source for emitting the remaining yellow light component (i.e., the green and red light components) is prepared to obtain an excellent color balance, as in the embodiments of FIGS. 3 and 4. Alternatively, the length of the optical path between the light source 31 for emitting the blue light component and the liquid crystal light valve 1 may be intentionally increased to obtain a length equal to that between the light source 32 for emitting the yellow light component and the liquid crystal light valves 2 and 3. This arrangement much facilitates white balance control.
FIG. 6 is a schematic view showing still another embodiment of the present invention. Light valves 1, 2, and 3 as imaging means form color images corresponding to the blue, green, and red light components, respectively. An apparatus in FIG. 6 also includes a projection lens 6, dichroic mirrors 11, 12, and 13, a total reflection mirror 20, and color light sources 33 and 34 having spectral characteristics for emitting a green color component and red and blue light components, respectively. These components of the apparatus have a layout, as shown in FIG. 6.
The green light source 33 is located immediately behind the liquid crystal light valve 2. Illumination light emitted from the color light source 34 is color-separated into red and blue light components by the dichroic mirror 12. The red and blue light components are radiated on the liquid crystal light valves 3 and 1, respectively. As in the previous embodiments described above, the loss of the divergent illumination light can be greatly reduced, and a brighter image forming apparatus can be arranged.
The respective light components pass through the liquid crystal light valves 1, 2, and 3 and are synthesized again through the total reflection mirror 20, the dichroic mirror 13 for reflecting the blue light component and transmitting the green light component, and the dichroic mirror for transmitting the red light component and reflecting the blue light component. The synthesized light is projected through the projection lens 6.
In this embodiment, if the dichroic mirrors 11 and 12 are designed to transmit the red light component and reflect the blue and green light components, the dichroic mirrors 11 and 12 can be identical to each other, thus resulting in an economical advantage. At this time, if the dichroic mirrors 11 and 12 are constituted by a single dichroic mirror, the number of optical elements and the number of positioning operations can be reduced.
Light passing through a dichroic mirror generally has a larger light amount loss than light reflected thereby. In this embodiment, the blue light component does not pass through a dichroic mirror, the loss of the blue light component can be minimized.
Alternatively, the length of the optical path between the light source 33 for emitting the green light component and the liquid crystal light valve 2 may be intentionally increased to obtain a length equal to that between the light source 34 for emitting the red and blue light components and the liquid crystal light valves 1 and 3. This arrangement much facilitates white balance control. If the dichroic mirror 11 is replaced with the dichroic mirror 10 for reflecting the red light component and transmitting the green and blue light components, the projection direction can be shifted by 90° as in the embodiment shown in FIG. 4.
FIG. 7 is a schematic view showing still another embodiment of the present invention. Liquid crystal light valves 1, 2, and 3 as imaging means form color images corresponding to the blue, green, and red light components. An apparatus in FIG. 7 also includes a projection lens 6, dichroic films 14 and 15 formed at the interfaces of prisms, and color light sources 31, 33, and 35 having spectral characteristics for generating the blue, green, and red color components, respectively. These components have a layout, as shown in FIG. 7.
The blue light source 31 is located immediately behind the liquid crystal light valve 1, so that the length of the illumination optical path is 1/4 or less that of the conventional example in FIG. 1. This also applies to the green and red light sources 33 and 35.
After the respective light components pass through the liquid crystal light valves 1, 2, and 3, they are synthesized again through the dichroic film 14 for reflecting only the blue light component and the dichroic film 15 for reflecting only the green light component. The synthesized light is projected through the projection lens 6.
When ease in design of the dichroic films is to be preferentially considered, a combination of a dichroic film for reflecting only the blue light component and a dichroic film for reflecting only the red light component is more preferable.
In this embodiment, the imaging means corresponding to the R, G, and B light components are illuminated with the R, G, and B light sources, respectively, so that an image forming apparatus having a very high luminance can be realized. As in the conventional example, when a color filter is attached to a white light source, the light amount is greatly reduced. In this embodiment and each embodiment described above, since light sources for emitting appropriate color light components are used, light utilization efficiency can be greatly improved.
In this embodiment, the dichroic prism is used as a color synthesis optical system. However, a crossed dichroic mirror as a combination of the dichroic mirrors described above may be used.
The color light sources described in each embodiment may have spectra matching desired conditions. In this case, a light source having a line spectrum is better than a light source having a wide emission spectrum because the width of chromaticity increases. As it is difficult to prepare a light source for a pure red light component at present, a combination of a light source having a larger amount of red light component than other components and a red filter for increasing purity of the red light component can be used. In this case, although the amount of red light component is slightly reduced by the filter, this combination is far better than the conventional arrangement obtained by attaching a color filter to a white light source when the total light efficiency including the blue and green light components is considered. Color filters may be used for color light sources except for the red light source to increase the color purities of other light components. Since these filters are used to increase the color purities, light amount losses are small. Note that as color light source materials in a metal halide lamp, sodium (Na-), indium (In-), and thallium (Tl-fased) gases are mixed for red, blue, and green, respectively, in addition to mercury.
In each embodiment described above, use of a plurality of light sources may cause unbalance in light amounts between the plurality of light sources with a lapse of time. An error occurs in white balance accordingly. A light amount adjusting means 73 as a means for correcting the white balance error may be arranged in each embodiment described above. Part of the synthesized light is directly received as white balance information or part of light reflected by a screen (not shown) upon incidence of the synthesized light is received as the white balance information while each liquid crystal light valve is set in a light-transmitting state. The white balance information is input to the illustrated light amount adjusting means 73. The light amount adjusting means 73 adjusts the light amount of at least one light source on the basis of the white balance information. For example, in the embodiment shown in FIG. 3, the liquid crystal light valve serves as both the image forming means and the light amount adjusting means. In the embodiment shown in FIG. 7, an ND filter is movably arranged to be inserted in an optical path as needed so as to perform light amount adjustment.
FIG. 8 shows still another embodiment of the present invention exemplifying its optical system. A reflector 43 comprises a cold mirror having a shape of a rotating ellipsoid. This ellipsoid has points a and b as focal points thereof. A light source 30 is located at the focal point b, and the pupil of a projection lens 6 is located at the focal point a. A liquid crystal light valve 41 is located at the middle position between the focal points a and b and is conjugate to a screen (not shown) through the projection lens 6. For this reason, as indicated by broken lines, light rays from the light source 30 and the reflector 43 are focused at an aperture of the projection lens 6 after the light rays pass through the liquid crystal light valve 41. A so-called Kohler illumination system is formed without using any condenser lens.
FIG. 9 is an enlarged sectional view of the liquid crystal light valve 41. A liquid crystal layer 65 is sandwiched between a TFT substrate 57 having TFTs, wiring lines 67, and transparent pixel electrodes 68, and a counter substrate 56 having an interference color filter 60 having R, G, and B phosphors in a mosaic shape, a total reflection film 61, and a transparent counterelectrode 63. Polarizing plates 54 and 55 are adhered to the outer surfaces of the substrates 56 and 57 in a parallel-Nicols state. In this case, a normally black mode is set. The interference color filter 60 is arranged in correspondence with the effective display area of each pixel, and the total reflection film 61 is formed in correspondence with a non-effective display area of each TFT and wiring line. The characteristic feature of this liquid crystal valve lies in a multilayered interference type color filter as the color filter. These layers of the multilayered film can be formed by photolithography such as multilayered film deposition or ion beam etching.
White illumination light W(P+S) as nonpolarized light from the light source and the reflector is converted into a white linearly polarized light component W(P) through the polarizing plate 54 and is converted into monochrome linearly polarized light components such as G(P) and R(P) by the interference color filter 60. These light components are incident on the liquid crystal pixels. On the other hand, the linearly polarized light components such as R+B(P) and G+B(P) reflected by the interference color filter return to the light source 30, as indicated by the broken lines in FIG. 8 because the liquid crystal light valve 41 is located at the middle position between the focal points a and b of the ellipsoid. Light returning to the light source 30 is directed again toward the light crystal light valve 41.
FIG. 10 is a plan view showing the liquid crystal light valve 41 when viewed from the light source. The interference color filter 60 having R, G, and B components corresponding to the pixels is formed in a display area 51 in a mosaic shape. The non-effective display area between the pixels except for the display area is covered with the total reflection film 61 formed on the transparent counter substrate 56. A circle 52 indicated by the alternate long and short dashed line in FIG. 10 represents an illumination area by the reflector 43 and the light source 30. 0f illumination light which illuminates the illumination area 52, illumination light components reaching the non-display area are reflected by the total reflection film 61. This reflected light returns to the light source 30 together with the light reflected by the interference color filter 60, as indicated by the broken lines in FIG. 8. The return light is then directed again toward the liquid crystal light valve 41.
According to this embodiment, since the non-effective light which is absorbed and disappears in the absorption type color filter and a light-shielding mask can return to the light source, this light can be utilized as illumination light again. That is, a return/reutilization loop is formed, and the light utilization efficiency of the illumination light can be greatly improved. Therefore, a brighter image forming apparatus can be realized. In addition, a Kohler illumination system can be formed in front of the liquid crystal light valve (i.e., on the light source side) without using any condenser lens.
In this embodiment, the reflector has a shape of an ellipsoid, but a hyperbolic reflector can be used to obtain the same effect as described above.
FIG. 11 shows still another embodiment exemplifying its optical system. A reflector 53 comprises a cold mirror having a shape of a rotating ellipsoid. This ellipsoid has points a and b as its focal points as in the above embodiment. A light source 30 is located at the focal point b, and the pupil of a projection lens 6 is located at the focal point a. A liquid crystal light valve 42 is located at the middle position between the focal points a and b.
A polarizing beam splitter 45 adhered with a total reflection mirror 20 is located between the liquid crystal light valve 42 and the reflector 53 to constitute a return type polarizing conversion system. Illumination light (non-polarized light) emitted from the light source 30 through the reflector 53 is split by a polarizing beam splitter surface 4 into a p-polarized light component having a polarization plane parallel to the drawing surface and an s-polarized light component having a polarization plane perpendicular to the drawing surface.
The p-polarized light component passes through the polarizing beam splitter surface 4 and illuminates the liquid crystal light valve 42. The s-polarized light component is reflected by the polarizing beam splitter surface 4, reflected again by the total reflection mirror 20, and is reflected by the polarizing beam splitter surface 4. This reflected light returns to the light source 30 because the position of the mirror surface 20 is located at a position equivalent to the middle position between the focal points a and b. In the process in which the reflector 53 reflects the s-polarized light component using the light source 30 as a secondary source, the s-polarized light component is scattered by the bulb portion of the light source 30 or reflected by the reflector 53 to disturb the polarization plane. The light having the disturbed polarization plane is split again by the polarizing beam splitter surface into p- and s-polarized light components. By repeating this process, almost all the light emitted from the light source 30 are polarized into the p-polarized components which are then incident on the liquid crystal light valve 42. The liquid crystal light valve 42 has a mode for polarizing the p-polarized light component. However, when the mode is selected such that the liquid crystal light valve 42 modulates the s-polarized light component, the positions of the liquid crystal light valve 42 and the total reflection mirror 20 need only be reversed.
The illumination light is focused at the aperture of the projection lens 6 by the focusing effect of the elliptical reflector 53 upon transmission through the liquid crystal light valve, as in the embodiment described above. A so-called Kohler illumination system can be formed without using any condenser lens. The liquid crystal light valve 42 has the same basic arrangement as that of the liquid crystal light valve 41 shown in FIG. 9 except for the incident-side polarizing plate 54. Light reflected by an interference color film 60 and the total reflection mirror 61 passes through a polarizing beam splitter 45 and returns to the light source 30 as in the above embodiment. In addition to the return/reutilization effect of the non-effective light reflected by the liquid crystal light valve 42 as in the above embodiment, illumination light is polarized and converted, thereby further improving the light utilization efficiency, and a brighter image forming apparatus can be realized.
An incident-side polarizing plate 54 as in the above embodiment can be arranged to increase the polarization ratio in this embodiment.
As a polarizing beam splitter, a plurality of parallel flat plates such as glass plates may be used overlapping each other in place of the prism type beam splitter. In this case, light is caused to become incident at a Brewster angle to split it into s- and p-polarized light components. This embodiment can realize a lighter apparatus.
FIG. 12 is a view showing an optical system according to still another embodiment. The embodiment in FIG. 12 is different from that of FIG. 8 in that a grid polarizing plate 49 is located on the light source side of a liquid crystal light valve. FIG. 13 is an enlarged sectional view of this liquid crystal light valve 42 and the grid polarizing plate 49.
The grid polarizing plate 49 is obtained by forming a metal grid (lattice) 58 on the surface of a transparent grid substrate 59 of quartz, glass, or the like. The pitch of the grid lines is preferably 50 nm or less. This grid can be formed by X-ray lithography or ion beam drawing. The grid polarizing plate is described in detail in Appl. Optics 6 (1967), 1023 or the like.
The operation of this embodiment will be described below. White illumination light W(P+S) as non-polarized light from the light source and the reflector is split into s- and p-polarized light components by a grid 58. More specifically, an s-polarized light component W(S) is reflected, and a p-polarized light component W(P) passes to illuminate the liquid crystal light valve 42. Since the grid 58 is located at the middle position between the focal points a and b of the elliptical reflector 43, the reflected s-polarized light component W(S) returns to a portion near the light source 30. Of the transmitted p-polarized light component W(P), a non-effective light component reflected by the interference color filter 60 and the total reflection film 61 also returns to a portion near the light source 30 because the reflection position is near the grid 58. As in the above embodiment, the s-polarized light component returning to the light source 30 has a disturbed polarization plane, and part of it serves as illumination light for the liquid crystal light valve 42. The non-effective light components reflected by the interference color filter 60 and the total reflection film 61 are also utilized as illumination light for the liquid crystal light valve 42 through the light source 30 and the reflector 43.
As described above, according to this embodiment, a brighter image forming apparatus obtained by return/reutilization and polarization of the illumination light can be realized by a very simple arrangement shown in FIG. 12.
A hyperbolic reflector may be used in place of the elliptical reflector 43 in this embodiment. As previously described above, when the light returning to the light source is reflected by a reflector to preferentially disturb the polarization plane, the hyperbolic reflector is better than the elliptical reflector due to the following reason. As can be apparent from FIG. 11, when the elliptical reflector is used, return light is reflected by the reflector and emerges. However, when the hyperbolic reflector is used, light is reflected twice and emerges, so that the polarization plane is disturbed much.
When the reception angle of light emitted from the light source is taken into consideration, the elliptical reflector is advantageous over the hyperbolic reflector. Therefore, these two reflectors can be appropriately used in accordance with application purposes.
FIG. 14 shows still another embodiment which exemplifies a direct viewing type image forming apparatus without using a projection lens. The arrangement of this embodiment is substantially the same as that of FIG. 8 except for the projection lens 6, and a detailed description thereof will be omitted. The apparatus of the embodiment shown in FIG. 14 has a cabinet 71 and a diffusion plate 72 for increasing the field angle. The embodiments shown in FIGS. 3, 4, 6, 7, 11, and 12 can equally cope with direct viewing type apparatuses.
The present invention is not limited to the particular embodiments described above. Various changes and modifications may be made without departing from the spirit and scope of the invention.
For example, the imaging means is not limited to the liquid crystal light valve. Any optical element such as a PLZT or the like may be used if it can change the state of the polarized light to obtain information light.
The means for splitting light from the light source into the p- and s-polarized light components is not limited to the polarizing beam splitter. Any optical element such as a birefringent lens made of an optically uniaxial material, a Wollaston prism, a Glan-Thompson prism, and a cholesteric liquid crystal layer if it can split light into a pair of different polarized beam components.
The present invention is not limited to a projector or a direct viewing type display apparatus, but can be extended to a recording apparatus such as a liquid crystal printer.
According to an aspect of the present invention, there is provided an image forming apparatus having a plurality imaging means for forming color-separated images and color-synthesizing means for synthesizing the image light components from the plurality of imaging means, characterized by comprising a plurality of light sources, wherein the plurality of imaging means are illuminated with different color light components.
According to another aspect of the present invention, there is provided a projector comprising an elliptical reflector and a light source located near one focal point of the elliptical reflector and a projection lens located such that a pupil thereof is located near the other focal point of the elliptical reflector, wherein imaging means is located at a position equidistantly spaced apart from both the focal points, so that non-image light reflected by the imaging means is directed near the light source.
According to still another aspect of the present invention, there is provided a projector having a reflector of a shape having at least one focal point, a light source arranged near the focal point, imaging means for modulating light from the light source to form an image, and a mosaic color filter for color-separating the light incident on the imaging means into red, green, and blue light components in a mosaic distribution, wherein the mosaic color filer comprises an interference filter for transmitting any of the red, green, and blue light components and reflecting remaining color components, and the reflected remaining light components are directed near the light source. In this manner, an image forming apparatus and a projector, in which color balance is excellent, and light utilization efficiency and resolving power are high, are obtained. | An image forming apparatus of this invention relates to an image forming apparatus for forming a color image and, more particularly, to a projector using the image forming apparatus. The image forming apparatus includes a color light illuminating system having first and second light sources for emitting different color light components, and first, second, and third imaging units or liquid crystal light valves for modulating the color light components to form color images. The first light source is a light source for mainly emitting two color components corresponding to the images formed by the first and second imaging units, and the second light source is a color light source for mainly emitting a color component corresponding to the image formed by the third imaging unit. | 6 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. application Ser. No. 07/133,831, filed Dec. 16, 1987, now abandoned, a continuation of which, U.S. application Ser. No. 07/609,041, filed Nov. 5, 1990, is now U.S. Pat. No. 5,115,023.
FIELD OF THE INVENTION
The present invention relates generally to the art of hydrolyric condensation polymers of organoalkoxysilanes, and also to the art of organic hybrid polymers of alkoxysilanes.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 4,405,679 to Fujioka et al discloses a coated shaped article of a polycarbonate type resin of improved abrasion resistance comprising a shaped polycarbonate substrate, an undercoat applied and cured on the substrate, and an overcoat applied and cured on the undercoat comprising a hydrolyzate of an epoxy-containing silicon compound, at least one member of the group of hydrolyzates of organic silicon compounds, colloidal silica and organic titania compounds, and a curing catalyst.
U.S. Pat. Nos. 4,500,669 and 4,571,365 to Ashlock et al disclose transparent, abrasion-resistant coating compositions comprising a colloidal dispersion of a water-insoluble dispersant in a water-alcohol solution of the partial condensate of silanol wherein the dispersant comprises metals, alloys, salts, oxides and hydroxides thereof.
In the Journal of Non-Crystalline Solids, Vol. 63, (1984), Philipp et al disclose in "New Material for Contact Lenses Prepared From Si- and Ti-Alkoxides by the Sol-Gel Process" that it is possible to combine inorganic and organic elements to develop materials with special properties.
U.S. application Ser. No. 07/440,845 filed Nov. 24, 1989 now U.S. Pat. No. 5,231,156 by Lin discloses organic-inorganic hybrid polymers prepared by polymerizing an organic monomer in the presence of an inorganic oxide sol comprising an organoalkoxysilane having an organic functional group capable of reacting with said organic monomer.
SUMMARY OF THE INVENTION
To combine the mechanical strength and stability of inorganic materials with the flexibility and film-forming ability of organic materials is an objective of this invention. Organic-inorganic hybrid polymers in accordance with the present invention are prepared by hydrolyric condensation polymerization of an organoalkoxysilane in the presence of a water soluble organic polymer such as polyvinylpyrrolidone.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Commercial abrasion-resistant coatings for stretched acrylic either contain colloidal silica and exhibit poor resistance to corrosion by solvents such as acetone and sulfuric acid, or are based on relatively soft organic polymer systems such as urethanes or melamines.
The hydrolysis of silanes of the general formula R x Si(OR') 4-x , wherein R is an organic radical, R' is a hydrolyzable low molecular weight alkyl group and x is at least one and less than 4, such as methyltrimethoxysilane, dimethyldiethoxysilane and γ-methacryloxypropyltriethoxysilane can be carried out under controlled conditions in the presence of appropriate additives and produces stable, clear solutions that exhibit excellent adhesion to unprimed stretched or cast acrylic. Cured coatings, preferably about four microns thick, typically exhibit Bayer abrasion results (i.e., percent haze after 300 cycles of one kilogram load) of 5-10 percent, have a stress crazing time of 17 minutes upon exposure to acetone and 30 minutes upon exposure to 75% sulfuric acid under 3000 pounds per square inch pressure, and remain crack-free for up to 1900 hours of ultraviolet radiation exposure.
Preferably, the silane hydrolyric polycondensation is catalyzed by an appropriate acid which is volatile and which does not lower the pH of the solution excessively. Preferred catalysts include acetic acid and trifluoroacetic acid. The temperature of the hydrolyric polycondensation reaction must be controlled either by external cooling, or by adjusting the solvent and acid composition to control the reaction rate, preferably not to exceed 45° C. A catalyst, preferably sodium acetate, is added to promote complete cure of the siloxane polymer at temperatures preferably in the range of 80° C. A high molecular weight water soluble organic polymer, preferably polyvinylpyrrolidone having a molecular weight of at least 300,000, is added for optimum film formation. The coated sample is subjected to standard Bayer abrasion testing for 300 cycles, and QUV-B exposure alternating 8 hours of ultraviolet irradiation at 60° C. and 4 hours at 45° C. and 100 percent relative humidity without ultraviolet irradiation. The above invention will be further understood from the description in the specific example which follows.
EXAMPLE I
A solution is prepared comprising 3.0 grams of polyvinylpyrrolidone dissolved in a solvent comprising 50 grams of water, 50 grams of methanol and 2 grams of formaldehyde (37% solution). The polyvinylpyrrolidone has a molecular weight of about 630,000 and is commercially available as K-90 from GAF Corp. A mixture of siloxanes comprising 80 grams of methyltrimethoxysilane and 8 grams of dimethyldiethoxysilane is added to the polyvinylpyrrolidone solution at room temperature, along with three drops of trifluoroacetic acid. After stirring the reaction mixture for two hours, 50 grams of isobutanol and 0.1 gram of sodium acetate trihydrate are added. After further stirring, the sol is filtered and applied to either stretched acrylic or cast acrylic by dip coating for five minutes at room temperature. No pretreatment of the acrylic surface is necessary. The coating is cured at 80° C. for 16 hours. After 300 cycles of Bayer Abrasion testing, the coated acrylic exhibits only 13.7 percent haze, compared with 50 percent haze for uncoated acrylic after the same abrasion testing.
EXAMPLE II
A solution is prepared comprising 18 grams of polyvlnylpyrrolidone dissolved in a solvent comprising 330 grams of deionized water and 330 grams of methanol. A second solution is prepared comprising 480 grams of methyltrimethoxysilane, 48 grams of dimethyldiethoxysilane and 24 grams of glacial acetic acid. The two solutions are combined, stirred for 2 hours at ambient temperature, and diluted with 300 grams of 2-propanol and 150 grams of diacetone alcohol containing 1.8 grams of sodium acetate. A stretched acrylic substrate is dipped into this coating composition and dried in air at ambient temperature for 5 to 10 minutes before curing the coating at 80° C. for 2 hours. After 300 cycles of Bayer Abrasion testing, the coated acrylic exhibits only 8 to 10 percent haze compared with 50 percent haze for uncoated acrylic after the same abrasion testing.
EXAMPLE III
Three grams of the polyvinylpyrrolidone of Example I are dissolved in a solution comprising 35 grams of deionized water and 35 grams of methanol. The solution is stirred for 15 minutes before adding 80 grams of methyltrimethoxysilane, 8 grams of dimethyldiethoxysilane and 4 grams of glacial acetic acid. The mixture is stirred for 2 hours at room temperature, after which 0.2 grams of sodium acetate is added and the mixture is diluted with 50 grams of 2-propanol. A stretched acrylic substrate is dip-coated into the above composition, and the coating is cured at 80° C. for 4 hours. The cured coating is then subjected to Bayer Abrasion testing with the result of 3.5 percent haze after 300 cycles. Ultraviolet radiation exposure testing (QUV-B) results in only light cracking of the coating after 1732 hours.
EXAMPLE IV
Three grams of the polyvinylpyrrolidone of the previous examples is dissolved in 55 grams of deionized water and 55 grams of methanol. After stirring the solution for 15 minutes, 80 grams of methyltrimethoxysilane, 8 grams of dimethyldiethoxysilane and 4 grams of glacial acetic acid are added to the polyvinylpyrrolidone solution. After stirring the sol for 2 hours, 0.2 grams of sodium acetate is added, and the sol is diluted with 50 grams of 2-propanol. A stretched acrylic substrate is dip-coated into the sol, and the coating is cured at 80° C. for 4 hours. The cured coating is subjected to Bayer Abrasion testing with a result of 3.2 percent haze after 300 cycles. In QUV-B testing at 60° C. the coating shows some debonding only after 1184 hours.
EXAMPLE V
Three grams of the polyvinylpyrrolidone of the previous examples are dissolved in 75 grams of deionized water and 75 grams of methanol. After stirring the solution for five minutes, 80 grams of methyltrimethoxysilane, 8 grams of dimethyldiethoxysilane and 4 grams of glacial acetic acid are added. After stirring for 2 hours at room temperature, 0.2 grams of sodium acetate and 50 grams of isopropanol are added. A stretched acrylic substrate is dip-coated into the above composition, and the coating is cured at 80° C. for 4 hours. The cured coating is subjected to Bayer Abrasion testing and shows 3.9 percent haze after 300 cycles.
EXAMPLE VI
Three grams of the polyvinylpyrrolidone of the previous examples are dissolved in 55 grams of deionized water and 55 grams of methanol. After stirring the solution for 15 minutes, 60 grams of methyltrimethoxysilane, 6 grams of dimethyldiethoxysilane and 4 grams of glacial acetic acid are added. After stirring for 2 hours at room temperature, 0.2 grams of sodium acetate and 50 grams of 2-propanol are added. A stretched acrylic substrate is dip-coated into the above composition, and the coating is cured at 80° C. for 4 hours. The cured coating is subjected to Bayer Abrasion testing with a result of 8.4 percent haze. The coating is also subjected to QUV-B exposure, and shows a few cracks after 1328 hours.
EXAMPLE VII
Three grams of the polyvinylpyrrolidone of the previous examples are dissolved in 55 grams of deionized water and 55 grams of methanol. After stirring the solution for 15 minutes, 78.5 grams of methyltriethoxysllane, 7.8 grams of dimethyldiethoxysilane and 4 grams of glacial acetic acid are added. After stirring at room temperature overnight, 0.2 grams of sodium acetate and 50 grams of 2-propanol are added. A stretched acrylic substrate is dip-coated into the above composition, and the coating is cured at 80° C. for 4 hours. The coating shows some cracks after 642 hours of QUV-B exposure.
EXAMPLE VIII
Eighteen grams of the polyvinylpyrrolidone of the previous examples are dissolved in 330 grams of deionized water and 330 grams of methanol. After stirring the solution for 15 minutes, 480 grams of methyltrimethoxysilane, 48 grams of dimethyldiethoxysilane and 24 grams of glacial acetic acid are added. After stirring at room temperature for 2 hours, 0.2 grams of sodium acetate, 300 grams of 2-propanol and 125 grams of diacetone alcohol are added. A stretched acrylic substrate is dip-coated into the above composition, and the coating is cured at 80° C. for 2 hours. The cured coating subjected to Bayer Abrasion testing shows 5.5 percent haze after 300 cycles, and has a few craze lines after 1406 hours of QUV-B exposure.
The above examples are offered to illustrate the present invention. The composition and concentration of the silane, constitution of the alcohol diluent, concentration and type of the acid catalyst, water content, organic polymer and proportion, and other reaction conditions may be varied in accordance with the present invention. The abrasion resistant siloxane organic hybrid polymer coating of the present invention may be used on other substrates. The scope of the present invention is defined by the following claims. | Siloxane organic hybrid polymers and a method of making them by condensation polymerization reaction of organoalkoxysilane in the presence of organic film-forming polymers are disclosed. | 2 |
BACKGROUND OF THE INVENTION
The invention relates generally to encoding of digital data. In particular, the invention relates to a Viterbi convolutional decoder.
The transmission of digital data, particularly for large amounts of data over long distances, must contend with a noisy transmission path. A typical digital communication system is designed to operate at a maximum data rate and a minimum power level. These conflicting requirements usually mean that the system is operating relatively close to the noise level associated with the transmission path. As a result, a significant number of transmitted bits will be overwhelmed by the transmission path noise and will not be accurately received. That is, the bit error rate becomes unacceptably high.
Reducing the transmission rate or increasing the power levels would reduce the bit error rate. However, a more attractive alternative for many systems is to accept the high bit error rate but to provide error correction for the transmitted data. Error correction usually involves an encoder at the transmitting side of the communication path that transforms the data intended to be transmitted according to an error correction code and, necessarily, increases the number of bits to be transmitted. Then a decoder, situated at the receiving end of the transmission path, performs the inverse transformation to the one performed by the encoder. That is, the decoder operates upon the received bits and reproduces the original data. Most importantly, the decoder can use the additional information in the expanded data stream to correct bit errors up to a maximum number. The maximum number of bit errors that can be corrected depends upon the type of coding scheme used and, obviously, depends upon the extra number of transmitted bits. In the usual type of coding scheme, the transmitted bits cannot be divided neatly into data bits and correction bits because the encoder performs fairly complicated mathematical operations upon the entire data stream to produce an expanded data stream.
One type of error correction coding divides the data into regularly sized blocks which the encoder converts to a larger block. The decoder, upon receiving the encoded block, decodes it into its original form, presuming that the maximum number of bit errors has not been exceeded. Another technique, the one used in this invention, does not explicitly block the data but instead encodes or decodes the data a few bits at a time. However, the encoding and decoding depends in an indirect way on data that has already been coded. For this reason, this technique is called convolutional coding. Many types of convolutional decoders are well known. Cain, III in U.S. Pat. No. 3,662,338 discloses a threshold convolutional decoder and Forney, Jr. in U.S. Pat. No. 3,665,396 discloses a sequential convolutional decoder. Encoders for either block or convolutional codes are relatively straightforward, but decoding procedures are far more complicated because they must both perform the inverse transformation and tolerate errors. The development of practical decoding algorithms for convolutional codes has centered around probabilistic decoding algorithms on one hand and threshold or feedback decoding procedures on the other hand.
Probabilistic decoding algorithms are a type of error correction used to calculate the likelihood of the successful message transmission for all possible transmissions on the basis of reliability information extracted from present and past ensembles. The maximum probability then is the determining factor for judging what was transmitted. This approach usually involves the concept of a path of unencoded data. A possible path is defined by the sequence of unencoded data. A probabilistic decoding algorithm then calculates the probability of each path based upon both the currently received encoded data, possibly corrupted by noise, and prior receptions. At some point, the path with the highest probability is judged to be the correct path and therefore the unencoded data is determined. As a result, a memory of a suitable size for the various paths and an arithmetic capability for a message probability computation are required. Viterbi in a technical article entitled "Error Bounds for Convolutional Codes" and appearing in IEEE Transactions on Information Theory, IT-13, April 1967, at pp. 260-269, described a specific path decoding algorithm for convolutional codes which significantly reduces the number of computations needed to choose the most probable path. The theory of Viterbi decoding is well described in U.S. Pat. No. 4,015,238 to Davis and in U.S. Pat. No. 3,789,360 to Clark, Jr. et al. The Viterbi algorithm has been shown to be an efficient and practical decoding technique for short constraint length codes (to be explained later) and has been demonstrated to be a maximum-likelihood procedure.
FIG. 1 shows a relatively simple convolutional encoder in which unencoded information bits are input to a three stage shift register 20. One adder 22 receives the outputs of the three stages of the shift register 20, b 2 , b 1 and b 0 while another adder 24 receives the outputs from only the first and last stage, b 2 and b 0 . Both the adders 22 and 24 are modulo 2 adders so that their individual outputs are 0 or 1. At each clock period, an information bit is shifted into the shift register 20 and the bits already present are shifted toward the right. Also during each clock period, the two adders 22 and 24 output their separate code. It is of course seen that one bit of input data produces two bits of output data, that is, n=1 and m=2 for a rate n/m encoder. For this reason, the encoder of FIG. 1 is called a rate 1/2 encoder.
If it is assumed that the two initial bits b 0 and b 1 are both set to 0, then for the next input bit b 3 =0, the code symbols (0,0) are output while if b 2 =1, then (1,1) is output. In the next clock period, b 3 is shifted into the position of b 2 , b 1 is substituted by b 2 and b 0 is substituted by b 1 . In this further clock period, however, the output code depends not only upon the value of b 3 but also upon b 2 . If (b 3 ,b 2 )=(0,0), then (O,O) is output in this clock period; if they equal (0,1), then (1,0) is output; if they equal (1,0), then (1,1) is output; and if they equal (1,1), then (0,1) is output. In the following clock period, the next input bit b 4 is shifted into the shift register with the remaining elements being shifted right. In this and following clock periods, the values of all three elements of the shift register 20 need to be considered in order to arrive at the correct output code symbols. However, no other input bits besides those three in the shift register 20 need to be considered. Accordingly, the encoder of FIG. 1 is said to have a constraint length of 3 or k=3.
FIG. 2 shows what is commonly known as a trellis for a convolutional encoder. The encircled numbers are the encoder states, that is the last two bits in the register 20, shown as b 1 and b 0 in FIG. 1. The paths from an encoder state are illustrated as solid when the next input bit, b 2 in FIG. 1, is a 0 and illustrated as dashed when the input bit is 1. Also shown enclosed in circles in FIG. 2 are the code symbols that are output from the adders 22 and 24, dependent not only upon the most recent input bit but also upon the state of the next two older bits. The initial encoder state at a depth of zero, as mentioned previously, is assumed to be (O,O), so that at the next depth of the trellis, there are two possible encoder states (O,O) and (1,0). At a trellis depth of 2, there are four possible encoder states, each reachable by only a single path for combinations of (b 3 ,b 2 ). What has been described to this point is simply a decisional tree. However, at a trellis depth of 3, there are again only four encoder states, each reachable by one of two paths. For instance, the encoder state (0,0) at trellis depth of 3 could be reached from an immediately prior encoder state of (0,0) with an input bit of 0 or from an encoder state of (0,1), also with an input bit of 0. The trellis pattern is repeated at each trellis depth greater than 3 for an encoder a constraint length of 3 encoder. The trellis diagram of FIG. 2 is important in convolutional decoders because it has been folded back to form a limited number of encoder states, four in FIG. 2, and the encoder states combined with the most recent input bit, constitute the total number of bits that need to be considered in the initial step of decoding.
The trellis diagram is used in decoding in the following manner. Only one path, defined by the sequence of input bits, is allowed to survive to any given encoder state at each trellis depth but there will be four surviving paths passing each trellis depth greater than the trellis depth of 2. When the next two-bit code symbol is received, the possible paths to the next trellis depth are used to generate tentative code symbols that can be compared with the received code symbol for the extension of the trellis to the new trellis depth. For each of the possible paths into one new encoder state, a probability is calculated as to whether that path had generated the current code symbol. Only the one path with the highest probability leading to that encoder state is allowed to survive. Thus it is seen that the surviving paths can cross, can branch and can become extinct, but always there are four surviving paths at each depth of the trellis.
Rather than calculate the probability that a particular path produced a particular sequence of received symbols, it is common to instead calculate the metric, which is a measure of the distance between the code symbols the path produced and the actually received code symbols. The minimum metric corresponds to the maximum probability. In the case where a hard decision is made on the received code symbols such that either one or the other of the two values of the bits in the code symbol is judged to have been received, then the metric is the number of differences between the received code symbols and the code symbols resulting from the path being evaluated. The advantage of using the metric is that, at each depth of the trellis, the metric is updated according to the most recently received symbols and it is not necessary to recompute the metric of the entire path.
In theory, the path histories for the entire transmission need to be maintained and only at the end of the transmission is the metric minimized to determine the path with the highest probability. This high probability path would then determine the entire transmission. However, in practice, once path histories for 4 or 5 constraint lengths have been calculated, it is highly likely that the oldest parts of the paths satisfactorily determine the input bits. This is explained by Viterbi in an article entitled "Convolutional Codes and Their Performance in Communication Systems", appearing in IEEE Transactions on Communication Technology, Vol. COM-19, No. 5, October 1971. Because of this fact, path histories are generally held in memory for only 4 or 5 constraint lengths and the oldest values are used as the result of the decoding.
It is seen that the decoder is very amenable to parallel design and processing since parallel paths through a multiplicity of encoder states must be calculated at each trellis depth. Parallel implementations are used by Davis and by Clark, Jr. et al in the previously cited patents. A parallel design appears to be implicit in the Viterbi decoders of Doland (U.S. Pat. No. 4,240,156) and Low et al (U.S. Pat. No. 3,697,950) who disclose the hardware for only one path. Obviously, parallel processing provides relatively high speed processors, perhaps with additional complexity due to the need for common metric and path memories. It must be borne in mind, however, that the rate 1/2 encoder, shown in FIG. 1, was presented for its ease of presentation. In fact, there are advantages to operating with longer constraint lengths. The number of encoder states, and thus the number of parallel processors in a parallel design, is 2 k-n , that is, an exponential function of the constraint length less the information bits per input state. For the Viterbi decoders to be described with this invention, there are 64 encoder states. Such a decoder may be very fast but its complexity becomes a limiting factor. For low-cost, low-data rate commercial digital earth stations, for use with satellite communication systems, the complexity of the parallel processing for Viterbi decoding has meant that the decoder hardware has not been available. Ironically, it is precisely in these low-cost stations that the potential coding gain achievable in the Viterbi decoding is most needed. Attempts to reduce the complexity of the individual elements for the parallel processors have compromised the path memory and constraint lengths of the preferred code.
SUMMARY OF THE INVENTION
Accordingly, it is an object of this invention to provide a Viterbi decoder of low complexity and low cost.
It is another object of this invention to provide a Viterbi decoder, the size of which is not exponentially dependent upon the constraint length.
It is yet a further object of this invention to provide a Viterbi decoder that uses serial rather than parallel architecture.
The invention can be summarized as a Viterbi decoder having a high speed arithmetic processor that serially performs the state calculations for all encoder states and which uses the same memory for all the paths.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of a rate 1/2 convolutional encoder with constraint length of 3.
FIG. 2 is a trellis diagram for the convolutional decoder of FIG. 1.
FIG. 3 is a schematic diagram of a rate 1/2 convolutional encoder with a constraint length of 7.
FIG. 4 is a schematic diagram of a rate 2/3 convolutional encoder with a constraint length of 8.
FIG. 5 is a general schematic diagram for the serial Viterbi decoder of this invention.
FIG. 6 is a block diagram illustrating the input section of the present invention.
FIGS. 7 and 8 are signal state diagrams for the rate 1/2 and 2/3 decoders, respectively.
FIG. 9 is a block diagram illustrating the branch metric look-up section.
FIG. 10 is an illustration for the organization of the branches linking the old and new encoder states in a rate 2/3 decoder.
FIG. 11 is a block diagram of the add-compare-select circuit.
FIG. 12 is a memory map of the path memory.
FIG. 13 is a block diagram of the path memory and traceback circuit.
FIG. 14 is a flow diagram illustrating the operation of the invention.
FIGS. 15 and 16 are circuit diagrams of the control circuitry for a rate 1/2 decoder and rate 2/3 decoder, respectively.
FIGS. 17 and 18 are timing diagrams for the control signals for a rate 1/2 decoder and rate 2/3 decoder, respectively.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Two separate Viterbi decoders will be described, one for a rate 1/2 encoder with a constraint length of 7 and another for a rate 2/3 encoder with a constraint length of 8. However, the invention can be used with a general rate n/m decoder. The corresponding convolutional encoders are shown in FIGS. 3 and 4 respectively as examples only. The rate 1/2 encoder, shown in FIG. 3, comprises a 7 bit shift register 26 in which the input data is clocked in a bit at a time. One modulo 2 adder 28 receives the outputs from b 0 , b 1 , b 3 , b 4 and b 6 . Another modulo 2 adder 30 receives the outputs from b 0 , b 3 , b 4 , b 5 and b 6 . There are two output symbols I and Q for each input bit. The rate 2/3 encoder is shown in FIG. 4 and consists of two 3-bit shift registers 32 and 34 and three modulo 2 adders 36, 38 and 40 receiving the bits indicated in FIG. 4. The particular connections shown in FIGS. 3 and 4 define the convolutional code and will need to be considered in constructing the corresponding Viterbi decoders. The input data for the rate 2/3 encoder is shifted in 2 bits per clock period, with 1 bit being shifted into each of the shift registers 32 and 34. For each of the two input bits, three bits of an output symbol define the code word.
The general architecture for the serial Viterbi decoder of the present invention is shown in FIG. 5. The data is received in a data input section 50 which converts the received signal in each signal period to a signal state recognizable within the decoder. An encoder state generator 52 generates one of the 64 encoder states of both the rate 1/2 and the rate 2/3 decoder. The generator further generates the branches that lead to the encoder state, two in the case of the rate 1/2 decoder and four in the case of the rate 2/3 decoder. With the combination of the prior encoder state and the branch, the generator 52 then produces a digital signal indicative of which combination of code symbols would have been received for the particular combination of the branch and the encoder state. This generation of a replica of the transmitted signal must correspond to the encoding code used in the transmitter. This symbol is combined with the output of the data input section 50 in the branch metric computation unit 54 which calculates the distance between the actually received data and the predicted reception based upon the tentative path, defined by the branch and the generated encoder state. This branch metric is then input to the state metric computation unit 56 which adds the branch metric to the state metric of the encoder state at the old end of the branch. This old state metric information is stored in a state metric memory 58. The state metric calculation is performed for each of the two branches (four branches for the rate 2/3 decoder) leading to the new encoder state. Then the branch and its associated prior path is selected which produces the minimum state metric. This new state metric is stored in the state metric memory 58 replacing the old value stored there for the particular encoder state. The branch having the minimum state metric to the new encoder state is stored in a path memory 62 for that encoder state. Once the path to an encoder state has been updated, based upon this previously described calculation, the encoder state generator generates the next of the 64 encoder states. The process is repeated until the next state metrics and the new paths have been calculated for all 64 states. Once all 64 path metrics have been calculated, the path having the minimum metric is chosen to define the oldest values of the paths stored in the path memory. A path traceback calculation unit 60 traces the path leading to the minimum metric encoder state back to its oldest entry based on path information in the path memory 62. This oldest information would be one bit for the rate 1/2 decoder and 2 bits for the rate 2/3 decoder. This data is output on a data output unit 64.
A synchronization unit 66 is required to maintain synchronization between the transmitted data and the timing of the decoder. The synchronization may be phase locked on the received data. The synchronization is triggered on a symbol-by-symbol basis on the recovered clock signal derived from a demodulator in the detector. A timing and control section 68 controls the operation of the decoder. An initialization unit 60 is required to initialize the state metrics and the path histories to zero values at the beginning of decoding for a message.
It is anticipated that the data is transmitted with M-ary phase shifted keying (MPSK). In M-ary phase shifted keying, the phase of a carrier wave is shifted to one of M values for each clock period of the transmitted carrier wave. Because the rate 1/2 encoder produces two bits for a code symbol in each clock period, there are four possible combinations of these symbols. Thus the rate 1/2 encoder requires quadrature phase shifted keying (QPSK). On the other hand, the three-bit code symbol output from the rate 2/3 encoder presents eight possible combinations so that octal phase shifted keying (OPSK) is required. At the receiving end, a quadrature detector detects the in-phase and out-of-phase components, I and Q, of the received wave for each clock period. The input section 50 for both a rate 1/2 and a rate 2/3 Viterbi decoder is shown in FIG. 6 in which the elements proper only to a rate 2/3 decoder are shown in dashed lines. A quadrature detector 70 for the rate 1/2 decoder has three-bit quantized outputs for both the I and the Q components while the corresponding detector 52 for the rate 2/3 decoder has four-bit quantized outputs. Other quantization levels are possible. The signal map for the rate 1/2 decoder is shown in FIG. 7 in which the signals corresponding exactly to the transmitted code signals are shown in the four corners. However, the signal diagram, quantized to three bits in both dimensions, allows for signals other than those precisely defined by the code symbols. The corresponding signal map for the rate 2/3 decoder is shown in FIG. 8 with the eight possible combinations of the transmitted code symbols illustrated in their respective signal locations. If a hard decision were to be made, then the signal locations associated with the received I and Q components would immediately be associated with the nearest allowed code symbol. For instance, in FIG. 8, if the signal a were received in a low noise background, it is fairly certain that a corresponds to the code symbol (000). However, in a noisy environment, the code symbol (000) may be corrupted to the signal location b because of such a noisy environment. In the present embodiment, the hard decision is not made but the fully quantized received signal is processed by the Viterbi decoder, that is, only a soft decision is made as to which of the 64 signal locations in the rate 1/2 decoder and which of the 256 signal locations for the rate 2/3 decoder does the received signal correspond. The 6 or 8 bits of signal location information are buffered in a data buffer 74 or 76. If an over-range capability were desired, the allowed symbols can be moved inward from the outside edges of FIGS. 7 and 8.
The branch metric is the distance between the received signal location and the code symbol that is proper for that branch. In actual practice, the square of the distance between the two signal states is calculated rather than the distance in order to make the metric values less susceptible to changes in the signal-to-noise ratio. This metric calculation can simply use the quantized numbers for judging what was transmitted. Other metrics, such as those based on log-likelihood or correlation product, can instead be used.
For the rate 2/3 decoder, the largest square distance or metric as seen in FIG. 8 is 346, which requires nine bits for binary representation. All distances are therefore scaled down to a smaller number so that a maximum square distance does not exceed a 5 bit representation, that is 31 10 . Similarly, the largest metric for the rate 1/2 decoder is seen from FIG. 7 to be a squared distance of 98, requiring 7 bits. Here the distances are scaled down so that the maximum metric of 51 10 does not exceed a 6 bit representation. A value of 51 was chosen because it results in a maximum possible value of 255 at the state metric adder output, to be described later, which thus utilizes the full range of 8-bit arithmetic. This scaling implies a loss in distance resolution but does not cause any significant degradation in performance. The metrics are still representative of the actual distances although the metrics corresponding to neighboring signal locations are all zeros because of the decreased distance resolution.
The distances from all the signal locations from each of the allowed code symbols, as represented in either FIG. 7 or 8, are programmed into a branch metric look-up table which is implemented in a programmable read-only memory (PROM) 84 located in the branch metric computation unit 54, as illustrated in FIG. 9. The PROM must be 256×6 for the rate 1/2 decoder and 2K×7 for the rate 2/3 decoder.
The encoder state generator 52 sequentially produces every combination of the encoder state and branch. Sixty-four encoder states are arranged, as illustrated in FIG. 10 for the rate 2/3 decoder, so that the state designator corresponds to the input bits which produce that state. Then the encoder state generator 52 can be a counter. The lowest bits of the output of the encoder state generator 52 then correspond to the input bits producing the branch. Note that only two of the four branches are illustrated in FIG. 10. Outputs of the encoder state generator 52 are led to an encoder replica circuit 86 that duplicates the operation of the encoders illustrated in FIGS. 3 and 4. Because the input bits are simultaneously available, the encoder replica circuit 86 could be implemented in a PROM. In fact, it is implemented as a shift register and associated gates or programmable array logic, just as is the encoder. The outputs of the encoder replica 86 designate the allowed code symbol combinations illustrated in FIGS. 7 and 8. For every set of data latched in the soft-decision data buffers 74 and 76, the encoder replica circuit 86 outputs one of four values for the rate 1/2 decoder and one of eight values for the rate 2/3 decoders.
The selection of the survivor path is made in add-compare-select (ACS) arithmetic circuit illustrated in FIG. 11. The function of the ACS section is to compute the new state metrics for all possible paths based upon branch metrics and to select the one path leading to the new encoder state having the lowest state metric. The state metrics for all encoder states are stored in two state metric memories 58a and 58b. The duplication of the state metric memories 58a and 58b can best be understood by referring again to FIG. 10 which shows the possible branches between the old encoder states on the left and the new encoder states on the right. If each of the locations, labeled by the identification of the encoder states, contains the value of the state metric, then the state metric of the old state is added to the branch metric, linking the old state to the new state, to produce the possible new state metric on the right. For the rate 2/3 decoder, there are four branches leading to each of the new states, each coming from a different old encoder state. The 4 possible new state metrics are compared and the state metric having the minimum value is selected. When the compared metrics have identical values, which is chosen is immaterial. In fact, the lowest numbered one is taken. The path associated with the minimum state metric is designated as the survivor path. Once all the new state metrics and associated paths have been selected, the decoding process continues for the next period of received data. Once of the state metric memories 58a and 58b is associated with the column on the left and one with the column on the right. Rather than transferring the contents of the new state metric memory to the old state metric memory upon beginning a new decoding step, the two memories alternate in their functions of old and new state metric memories, that is, in one decoding period one of the memories 58a and 58b is being read from and the other being written into and, in the next decoding period, they perform the opposite function. There is thus no need to explicitly erase the contents of the state metric memories 58a and 58b since they will necessarily be overwritten in a subsequent step. A read address designates the old encoder state and a write address designates the new encoder state. A multiplexer 90 switches one of the read and write addresses when concurrently used to the correct state metric memory 58a or 58b. The old state metric is read from one of the memories 58a or 58b into an adder 92 which adds that value to the branch metric being output from the branch metric look-up table 84 to produce the possible new state metric. An overflow detector 94 detects if the results of the addition of the branch metric and state metric results in an overflow. An active overflow detector 94 indicates to the operator that the branch metric look up table 84 has been programmed with excessively large metrics.
The output of the adder 92 is led to a survivor selector 96 which compares the possible new state metrics leading to each new encoder state. For the 4 possible paths in a rate 2/3 decoder, the survivor selector 96 selects the path having the smallest new state metric. As can be seen from FIG. 10, the oldest two bits to the right of the old encoder state column indicate which of the branches to the new encoder state is the survivor. These two bits of the survivor are input to a path information generator 98 for storage in the path memory. The surviving state metric is input to a subtractor 100 in which it is decreased by the value of the minimum state metric of the previous decoding period. This prior minimum state metric is selected and stored in a minimum state metric selector that receives all state metrics for one decoding period, selects the minimum value and outputs this minimum value for the next decoding step. The subtraction of the minimum state metric prevents the adder 92 from overflowing and thus producing invalid outputs. The adjusted state metric output by the subtractor 100 is then stored in the state memory 58a or 58b that is designated as the new state metric memory.
The organization of the path memory is illustrated in FIG. 12. The row address corresponds to the encoder state designation, in particular, the designation of the new encoder state during a decoding period. The column address corresponds to a frame number which increments once per decoding period and wraps around from frame number 63 to frame number zero. The contents of each location is the survivor designation for that new encoder state in that frame. That is, the oldest two bits of the old encoder state that provided the minimum value metric to the new encoder state is stored. The survivor designation provides sufficient information for the trace back operation to be described later.
The path memory and trace back system is illustrated in FIG. 13 in which the survivor designation is input from the ACS section to the path memory 62. In the storage of the survivor designation, a frame is set to a column write address which is selected by a column address multiplexer 110 which addresses the columns of the path memory 62. In the storage, the row of the path memory 62 is designated by a row write address routed to the memory 62 through row address multiplexer 112. The column write address is the frame number and the row write address is the new encoder state designator.
The operation of the ACS section will now be described with reference to the flow diagram of FIG. 14. After start, the frame number ROW and index r are set to 0. The frame number relates to the decoding period. The ROW number corresponds to the new encoder state and also addresses the rows of the path memory 62. The index r corresponds to the designation of the old encoder state and equals the lowest six bits of the encoder state generator 52. Then new values of I and Q are latched. These values represent the received data in one decoding period. Then the old state metric designated by the index r is taken from the state metric memory 58A or 58B which is the current old state metric memory. Also, the branch metrix is obtained by inputting the index r and the highest two bits of the row address from the encoder state generator 52 through the encoder replica circuit 86 to the branch metric look-up table 84. The remaining address inputs to the table 84 are controlled by the quantized values of the latched I and Q. The output of the table 84 is the metric for this branch. A new state metric indexed by r is then calculated by adding in the adder 92 the old state metric and the branch metric. This value is temporarily stored in register A and represents the state metric for one of the four possible paths (in the rate 2/3 decoder) leading to the new encoder state. The current index r is stored in another register B to indicate to which state the metric belongs. Then the index r is incremented by 1. If, as a result, the index r has a value greater than 63, the index r is set to 0. It should be noted, at this time, that during one decoding period, the old encoder states represented by r are processed sequentially four different times while the new encoder states represented by the ROW address are processed only once. Then based upon the incremented value of r, the old state metric and the branch metrics, based upon the index r, are obtained and a possible new state metric is the sum of the two.
The possible new state metric is then compared with the value of A and the lesser of the two is stored back in A, that is, the lesser state metric is selected. If the register A is replaced, then the register B is updated with the current value of r. A test is then made as to whether r has been incremented three times for the rate 2/3 decoder (or one time for the rate 1/2 decoder), indicating that all four (or two paths) into the new encoder state have been evaluated. If not, the flow returns to increment the value of r to obtain another old encoder state.
If all paths into a new encoder state have been evaluated, then the register b designates the survivor with the minimum state metric which has been determined by the minimization of A. The survivor designation of the register B is stored in the path memory 62 at the location (FRAME+1, ROW). The designation of the path which is stored at this location is the lowest order two bits of r for the rate 2/3 decoder (lowest order bit for rate 1/2 decoder) that produce the minimum value of A. The minimum state metric of the preceding frame is subtracted from the value of A which is stored in the new state metric memory 58A or 58B. Then the ROW is incremented to indicate the processing of a further new encoder state. ROW is compared to the value 63 and if less than or equal to 63, r is incremented in modulo 64 and processing continues for a further new encoder state. If ROW is greater than 63, then all new encoder states have been processed and this decoding period is completed.
The one or two data bits to be output for the current frame or period are then determined by the following procedure. The designation r of the encoder state with the minimum state metric for the frame is used in the trace back of the path memory 62. As illustrated in FIG. 12, the trace-back is performed frame by frame, beginning at the most current complete frame. The next traceback ROW address is found by shifting the present bits of the path memory 62 pointed to by the ROW address 112 into the lower bit(s) of the ROW address generator 114. The number of bits shifted in are two for the rate 2/3 decoder and one for the rate 1/2 decoder. For instance, as illustrated in FIG. 12, if the trace-back begins in Frame 17 and the minimum state metric belongs to encoder state 1 that has a survivor designation of 0, indicating the branch to that encoder state, then the next prior encoder state in the path is encoder state 4. The process is repeated a total of 62 times to work back to the oldest survivor designation in the minimum metric path. The contents of this location are the oldest bits in the path which are then output. The FRAME is then incremented in modulo 64 addition and control returns to the frame or decoding period.
Although the trace-back could be performed between frames, in fact, the trace-back for one frame is performed concurrently with the updating of the next frame. For each of 62 of the 64 values of ROW, one step of the trace-back is performed. Thus, at the end of a frame update, the output data is ready from the previous frame.
What has been described is a strictly serial implementation. Another embodiment, particularly suitable for the rate 1/2 decoder, provides two parallel add-compare-select sections. These two sections each sequentially operate on the 64 old encoder states. However, one section processes the branches to the upper 32 new encoder states while the other section process the branches to the lower 32 new encoder states. As a result, it is not necessary to twice sequence the old encoder states.
The timing and control 64 necessary for the operation of the decoder are shown in FIG. 15 for the rate 1/2 decoder and for the rate 2/3 decoder in FIG. 16. The signals at the timing and control 68 are presented in Table 1 for the rate 1/2 decoder and in Table 2 for the rate 2/3 decoder. The timing diagrams for the control signals are shown in FIG. 17 for the rate 1/2 decoder and in FIG. 18 for the rate 2/3 decoder.
TABLE 1______________________________________RATE-1/2 DECODER CONTROL SIGNALS______________________________________LDNN This loads in the new symbol at the start of each frame.RCO-5 Six address lines from the read counter, producing the index r, that are used for the encoder replica and the state metric RAMs.STORE A/B Temporarily stores state metric in register A to be compared to the next one. Also stores register B.FRZ This signal preserves data at the minimum state metric selector until the previous minimum state metric is clocked to the subtractor input.FRC Forces the survivor metric of the first two states into the minimum state metric selector at the start of a frame.WCO-5 Six address lines from the write (ROW) counter used to indicate the write address for the state and path memories. ##STR1## Write enables for the state metric RAMs and the path memory.PREV This clocks out the previous frame minimum state metric to be used for subtraction in the state metrics of the present frame.TRAS Path memory address selector to a multiplexer which selects a read or write address. Toggles at the be- ginning of every read count.SHLD Loads the optimum starting address for the path traceback, that is, encoder state with minimum state metric in previous frame.TRCO-5 Six address lines from the traceback counter. Down counter is decre- mented every time a path information bit is read out.CCO-5 Six address lines from the column counter used to indicate the column address for the path memory. Incremented once every frame.TRWCO-5 Address lines from the write counter used to indicate the write address (ROW) for the state and path memories. Same as WCO-5.DCLK Clocks out the decoded data bit at the end of frame.______________________________________
TABLE 2______________________________________RATE-2/3 DECODER CONTROL SIGNALS______________________________________FLOAD Load signal derived from the sync signal. This loads the minimum frame metric, resets the read count- er, increments the column counter, loads the traceback counter, and loads the row location of the pre- vious frame minimum metric.IQLOAD Loads the new I and Q coordinates.PTHEN Path enable signal. Loads 00 in the path buffer, which corresponds to the first survivor designation of the first member in a group of four in the present column.LD Resets the write counter and starts the ring counter. Most processes occur in multiples of four for rate 2/3 decoder. A ring counter counts out the four cycles.M.sub.0 LOAD Loads the first survivor metric of the new frame, which is used to compare with other survivors to determine the frame minimum metric.RC 0-5 Address lines from the read counter used for the encoder replica and the state metric RAMs.CC 0-5 Address lines from the column counter used to indicate the column address for the path memory. Incremented once every frame.TC 0-5 Address lines from the traceback counter. Downcounter decremented every time a new survivor is written in.WC 0-5 Address lines from the write counter (ROW) used to indicate the write address for the state and path memories.CO.sub.wc Carry out signal from the write counter used to identify the end of one frame. This is gated through appropriate logic to shut down the system and enable the sync section for the next I and Q coordinate. ##STR2## Metric Enable: used to force into registers A and B the first state metric and the first survivor desig- nation for each group of four in the ACS section. ##STR3## Write Counter Enable: increments the write counter (ROW) after each survivor is determined.PCLK Path Clock: Shifts 2 bits of the path memory pointed to by the row address register into the row ad- dress register for the next trace- back step. ##STR4## Trace Counter Enable: decrements the traceback counter for each survivor written in.BC 0-1 Branch Code: used as the path designation for each survivor in a group of four. These are the lowest order two bits of index r.PTOG Path Multiplexer Signal (path toggle): switches the column count- - er for writing or the traceback counter for reading out into the path memory address. ##STR5## Write enables for the state metric RAMs and the path memory.G.sub.state metric Enable line for metric and path registers A and B in the ACS ##STR6## forcing in of the first metric in a group of four, then becomes condi- tional depending on the values of the other three metrics in the group.CLR.sub.Rgc Clear Ring Counter. Clearing the ring counter disables the whole system. Occurs when the frame is over.DLOAD Data load: used to load the decoder data bits.______________________________________ | A serial Viterbi decoder in which a single set of circuits is sequentially used for all the encoder states to calculate the maximum probability path, as measured against received signals, of unencoded signal sequences to reach each encoder state. The path to any encoder state having the maximum probability is traced back to output the oldest encoded signals. | 7 |
CROSS REFERENCE TO RELATED APPLICATION
This application claims priority to U.S. Provisional Patent Application No. 60/215,479, filed Jun. 30, 2000.
FIELD OF THE INVENTION
This invention relates to a method for imparting soil-resistant and water-repellent properties to fibrous polyamide substrates (such as carpet fibers) by applying an acidic aqueous treating solution containing a silsesquioxane. This invention also relates to the treating solution used to impart soil resistance, and water repellency to the fibrous substrate. This invention also relates to treated fibrous substrate made according to the method of this invention.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 3,493,424 (Mohrlok et al.) describes fibrous materials which are given antislip, dulling, and/or dry-soiling resistance properties by applying a colloidal suspension of a silsesquioxane, followed by drying the material.
U.S. Pat. No. 4,351,736 (Steinberger et al.) describes a textile pile-stabilizing impregnating agent comprising a colloidal suspension of silicic acid and organosilsesquioxanes.
U.S. Pat. No. 4,781,844 (Kortmann et al.) describes a textile finishing agent comprising an aqueous colloidal suspension of an organosilsesquioxane-containing sol and an organic polymer resin containing perfluoroalkyl groups which imparts soil resistance.
SUMMARY OF THE INVENTION
This invention describes a novel process for applying an aqueous acidic treatment comprising a silsesquioxane to a fibrous substrate; preferably carpet, to produce fibers that are totally and uniformly treated. Surprisingly, it has been discovered that the anti-soiling and repellent properties of the silsesquioxane compositions are enhanced at low pH. None of the treating compositions and methods described in the art discloses a method for treating a fibrous substrate using an acidic composition comprising a silsesquioxane to simultaneously achieve good antisoiling and good stain resistance properties.
Specifically, this invention relates to a method for imparting repellency and soil resistance to a fibrous substrate comprising the steps of:
(a) contacting the fibrous substrate in a way to cause total wetting with aqueous acidic composition comprising a silsesquioxane
(b) treating the fibrous substrate using a combination of a sufficiently high temperature and a sufficient long time to effectively exhaust the treating materials onto the fibrous substrate; and
(c) drying the wet treated substrate.
This invention also describes the resulting treated fibrous substrates that exhibit excellent anti-soiling and repellency performance.
The treating process for applying the aqueous acidic composition comprising silsesquioxane can be either an exhaustion process or a topical process. In the exhaustion process, a fibrous substrate is first treated exhaustively by contacting the entirety of each fiber of the substrate with the aqueous composition of this invention. Following the contacting step, the resulting totally wet fibrous substrate is then heated in a water-saturated atmosphere such as a steam box for a time sufficient to affix the treating composition onto each fiber surface. The heated wet fibrous substrate is subsequently rinsed with water and is dried in an oven at sufficient temperature to effectively activate the treating composition on the surface of each fiber. In some cases, application at a sufficient high bath temperature (e.g., over 200° F. (83° C.)) can eliminate the need for the post-steaming operation. The fibrous substrate, having had total penetration throughout each fiber, exhibits significant protection again soiling when compared to untreated carpet as demonstrated by several cycles of “walk-on” tests, and exhibits excellent dynamic water resistance (i.e., the treated carpet resists penetration by water-based drinks spilled from a height).
Examples of suitable exhaustion processes for treating fibrous substrates include immersion, flooding, Beck vat processing, hot otting, padding and puddle foaming application. Useful treating equipment includes equipment available from Eduard Kusters Maschinefabrik GmbH & Co. KG, Krefeld, Germany, such as Kuster's Flex-nip™ equipment, Kuster's foam applicator, Fluicon™ flood applicator and Fluidye™ unit.
Suitable topical treating processes for applying the aqueous acidic composition comprising silsesquioxane include spraying and low density foam application. However, exhaustion treating processes are preferred as they impart superior performance to the treated fibers.
To impart antisoiling resistance to the fibrous substrates, the treating compositions of this invention contain silsesquioxanes. Useful silsesquioxanes include compounds of the formula RSiO 3/2 where R is an optionally substituted alkyl or aryl of up to 7 carbon atoms, and/or co-condensates of hydrosylates of tetraalkoxysilanes with organotrialkoxysilanes having RSiO 3/2 or SiO 2 units. Useful silsesquioxanes are described in U.S. Pat. Nos. 3,493,424, 4,351,736 and 4,781,844, each incorporated herein by reference. Preferred silsesquioxanes are neutral or anionic silsesquioxanes, prior to addition to the composition.
Suitable fibrous substrates includes carpet, fabric, textiles and any substrate woven from fibers such as yarn or thread; carpet is the preferred form of the fibrous substrate. The fiber can be made from any number of thermoset or thermoplastic polymers, such as polyamide, polyester, acrylic and polyolefin; polyamide (e.g. nylon) is the preferred fiber.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The silsesquioxane materials can be any of the types described in U.S. Pat. No. 4,781,844 (Kortmann, et al), U.S. Pat. No. 4,351,736 (Steinberger et al.), U.S. Pat. No. 5,073, 442 (Knowlton et al.) or U.S. Pat. No. 3,493,424 (Mohrlok et al.) each of which are incorporated herein by reference. These silsesquioxanes are of the formula R—Si(OR′)3 alone or together with silanes of the formula Si(OR′)4 wherein R represents a substituted or unsubstituted hydrocarbon radical having 1 to 7 carbon atoms, substituents of which may be halogen atoms and amino, mercapto and epoxy groups, and up to 95% of the R radicals may be methyl groups. R′ represents an alkyl radical with 1 to 4 carbon atoms. Preferred silsesquioxanes are those that are neutral or anionic.
The silsesquioxanes may be prepared by adding silanes to a mixture of water, a buffer, a surface active agent and optionally an organic solvent, while agitating the mixture under acidic or basic conditions. It is preferable to add the quantity of silane uniformly and slowly in order to achieve a narrow particle size of 200 to 500 Angstroms. The exact amount of silane which can be added depends on the substituent R and whether an anionic or cationic surface active agent is used.
Copolymers of the silsesquioxanes in which the units can be present in block or random distribution are formed by the simultaneous hydrolysis of the silanes. The preferred amount of silane of the formula Si(OR′) 4 added is about 2 to 50 percent, relative to the total weight of the silanes employed, prefereably 3 to 20 percent.
The following silanes are useful in preparing the silsesquioxanes of the present invention: methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxyoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, 2-ethylbutyltriethoxysilane, tetraethoxysilane, and 2-ethylbutoxytriethoxysilane.
Generally the composition of this invention comprises from about 0.01 to 1.0 grams of silsesquioxane (0.0025 to 0.25 wt %) dissolved or dispersed in 400 g of water. This composition may be used to exhaustively treat about 100 g of carpet. Preferably the composition comprises from about 0.05 to 0.5 grams of silsesquioxane. The aqueous composition may be rendered acidic by the addition of any inorganic or organic acid, with inorganic acids such as sulfuric being preferred. The acidic aqueous composition preferably has a pH of 4 or less, and more preferably 2 or less.
EXAMPLES
Unless otherwise specified, all percentages shown in the examples and test methods which follow are percentages by weight.
Glossary
SSQO—To a 3-L 3-necked flask equipped with heater, stirrer and condenser was added 1106.0 g of deionized water and 14.0 g of linear alkylsulfonic acid (available from Alfa Aesar Johnson Matthey Ward Hill, Mass.), believed to be dodecylbenzenesulfonic acid). The resulting mixture was heated to 60° C. with stirring until homogeneous, and 280 g of CH 3 Si(OCH 3 ) 3 (methyltrimethoxysilane, available from Sigma Aldrich) was slowly added to the mixture over a 4 hour period. The hydrolysis reaction was allowed to continue overnight at 60° C. with stirring, the resulting reaction product was filtered, then sufficient 20% aqueous NH 4 OH was added to adjust the pH of the mixture to 7. The neutralized mixture was then stripped using a rotary evaporation at a temperature of 50° C. to produce 530 g of distillate consisting primarily of methanol with a small amount of water. The anionic emulsion of silsesquioxane that had formed was 14% solids and had an average particle diameter of approximately 30 nm, as measured using the Multi Angle Sizing (MAS) option on a Zeta Plus zeta potential analyzer (available from Brookhaven Instruments Corp., Holtsville, N.Y.).
UPBEAT—UPBEAT™ nylon 6 carpet, light cream color, color no. 45101, style 51145, having a face weight of 26 oz/yd 2 (0.93 kg/m 2 ), available from Shaw Industries, Dalton, Ga.
T-3—TRANSITION III™ nylon 6,6 carpet, “Blue Moon” color, having a face weight of 36 oz/yd 2 (1.2 kg/m 2 ), available from Burlington Industries, Greensboro, N.C.
Test Methods
The following is a description of the test methods referred to in the Examples and specification.
Simulated Flex-Nip Application Procedure—The Simulated Flex-Nip Application Procedure described below was used to simulate the flex-nip operations used by carpet mills to apply stainblocking compositions to carpet.
In this test, a carpet sample measuring approximately 5 inches by 4 inches (13 cm×10 cm), typically weighing approximately 100 g, is immersed in deionized water at room temperature until dripping wet. Water is extracted from the wet sample by spinning in a Bock Centrifugal Extractor (available from Bock Engineered Products, Inc., Toledo, Ohio) until the sample is damp. The damp carpet sample is then steamed for 2 minutes at atmospheric pressure, at a temperature of 90-100° C., and 100% relative humidity in an enclosed steam chamber.
After steaming, the carpet sample is allowed to cool to near room temperature, and the aqueous treating composition is applied by placing the carpet sample, carpet fiber side down, in a glass tray containing the treating composition. The treating composition contains sufficient treating material(s) to give the desired percent solids on fiber (% SOF) and is prepared by dissolving or dispersing the treating materials in deionized water and adjusting the pH of the resulting aqueous treating solution to desired value using 10% aqueous sulfamic acid. The weight of the treating solution present in the glass tray is approximately 4 times the weight of the carpet sample (e.g., 400 g of treating solution for a 100 g carpet sample). The carpet sample absorbs the entire volume of treating solution over a 1 to 2 minute period to give a percent wet pickup of approximately 400%.
Then the wet treated carpet sample is steamed a second time for 2 minutes (using the same conditions and equipment as described above), is immersed briefly in a 5-gallon bucket half full of deionized water, is rinsed thoroughly under a deionized water stream to remove residual, excess treating composition, is spun to dampness using the centrifugal extractor, and is allowed to air-dry overnight at room temperature before testing.
Water Repellency Test—Treated carpet samples were evaluated for water repellency using 3M Water Repellency Test V for Floorcoverings (February 1994), available from Minnesota Mining and Manufacturing Company. In this test, treated carpet samples are challenged to penetrations by blends of deionized water and isopropyl alcohol (IPA). Each blend is assigned a rating number as shown below:
Water Repellency
Water/IPA
Rating Number
Blend (% by volume)
F
(fails water)
0
100% water
1
90/10 water/IPA
2
80/20 water/IPA
3
70/30 water/IPA
4
60/40 water/IPA
5
50/50 water/IPA
6
40/60 water/IPA
7
30/70 water/IPA
8
20/80 water/IPA
9
10/90 water/IPA
10
100% IPA
In running the Water Repellency Test, a treated carpet sample is placed on a flat, horizontal surface and the carpet pile is hand-brushed in the direction giving the greatest lay to the yarn. Five small drops of water or a water/IPA mixture are gently placed at points at least two inches apart on the carpet sample. If, after observing for ten seconds at a 45° angle, four of the five drops are visible as a sphere or a hemisphere, the carpet is deemed to pass the test. The reported water repellency rating corresponds to the highest numbered water or water/IPA mixture for which the treated carpet sample passes the described test.
Dynamic Water Resistance Test—Dynamic water resistance was determined using the following test procedure. A treated carpet sample (15.2 cm×15.2 cm) is inclined at an angle of 45° from horizontal and 20 g of deionized water is impinged onto the center of the carpet sample through a glass tube with 5 mm inside diameter positioned 45.7 cm above the test sample. The increase in weight (g) of the test sample is measured, with lower weight gains indicating better dynamic water repellency properties.
“Walk-On” Soiling Test—The relative soiling potential of each treatment was determined by challenging both treated and untreated (control) carpet samples under defined “walk-on” soiling test conditions and comparing their relative soiling levels. The test is conducted by mounting treated and untreated carpet squares on particle board, placing the samples on the floor of one of two chosen commercial locations, and allowing the samples to be soiled by normal foot traffic. The amount of foot traffic in each of these areas is monitored, and the position of each sample within a given location is changed daily using a pattern designed to minimize the effects of position and orientation upon soiling.
Following a specific soil challenge period, measured in number of cycles where one cycles equals approximately 10,000 foot-traffics, the treated samples are removed and the amount of soil present on a given sample is determined using colorometric measurements, making the assumption that the amount of soil on a given sample is directly proportional to the difference in color between the unsoiled sample and the corresponding sample after soiling. The three CIE L*a*b* color coordinates of the unsoiled and subsequently soiled samples are measured using a 310 CHROMA METER™ color analyzer with a D65 illumination source. The color difference value, ΔE, is calculated using the equation shown below: Δ E = [ ( Δ L * ) 2 + ( Δ a * ) 2 + ( Δ b * ) 2 ] 1 / 2
where:
ΔL*=L*soiled−L*unsoiled
Δa*=a*soiled−a*unsoiled
Δb*=b*soiled−b*unsoiled
ΔE values calculated from these colorometric measurements have been shown to be qualitatively in agreement with values from older, visual evaluations such as the soiling evaluation suggested by the AATCC, and have the additional advantages of higher precision, being unaffected by evaluation environment or subjective operator differences. The reported ΔE value for each carpet sample is calculated as an average of between five and seven replicates. The lower the reported ΔE value, the better the soil resistance.
Receding Contact Angle Test—The Receding Contact Angle Test provides a quick and precise prediction of the anti-soiling potential of fluorochemical repellent or hydrocarbon repellent candidates. Using this test procedure, receding contact angle values measured with n-hexadecane have correlated well with anti-soiling values measured from actual foot traffic using the “Walk-On” Soiling Test.
To run this test, the repellent candidate is applied to nylon film as a solution, emulsion, or suspension (typically at about 3% solids) via dip-coating. The nylon film is prepared as follows. Nylon film is cut into 85 mm×13 mm rectangular strips. Each strip is cleaned by dipping into methyl alcohol, wiping with a KIMWIPE™ wipe (commercially available from Kimberly Clark Corp., Boswell, Ga.), taking care not to touch the strip's surface, and allowing the strip to dry for 15 minutes. Then, using a small binder clip to hold one end of the strip, the strip is immersed in the treating solution, and the strip is then withdrawn slowly and smoothly from the solution. The coated film strip is tilted to allow any solution run-off to accumulate at the corner of the strip, and a KIMWIPE™ tissue is touched to the corner to pull away the solution buildup. The coated film strip is allowed to air dry in a protected location for a minimum of 30 minutes and then is cured for 10 minutes at 121° C.
After the coated film strip has dried and cured, a drop of n-hexadecane is applied to the strip and the receding contact angle of the drop of is measured using a CAHN Dynamic Contact Angle Analyzer, Model DCA 322 (a Wilhelmy balance apparatus equipped with a computer for control and data processing, commercially available from ATI, Madison, Wis.). The CAHN Dynamic Contact Angle Analyzer is calibrated using a 500 mg weight. An alligator clip is fastened to a piece of coated film strip about 30 mm long, and the clip and film piece are hung from the stirrup of the balance. A 30 mL glass beaker containing approximately 25 mL of n-hexadecane is placed under the balance stirrup, and the beaker is positioned so that the coated film strip is centered over the beaker and its contents but not touching the walls of the beaker. Using the lever on the left side of the apparatus, the platform supporting the beaker is carefully raised until the surface of n-hexadecane is 2-3 mm from the lower edge of the film strip. The door to the apparatus is closed, the “Configure” option is chosen from the “Initialize” menu of the computer, the “Automatic” option is chosen from the “Experiment” menu, and the computer program then calculates the time for a total of 3 scans. The result should be a time interval of 1 second and estimated total time of 5 minutes, which are the acceptable settings to show the baseline weight of the sample. The Return Key is then pressed to begin the automatic measurement cycle. Ten readings of the baseline are taken before the scan begins. The apparatus then raises and lowers the liquid so that 3 scans are taken. The “Least Squares” option is then selected from the “Analysis” menu, and the average receding contact angle is calculated from the 3 scans of the film sample. The 95% confidence interval for the average of the 3 scans is typically about ±1.2°.
Glass Transition Temperature Measurement—Glass transition temperatures of materials can be measured according to ASTM E 1356-91, “Standard Test Method for Glass Transition Temperatures by Differential Scanning Calorimetry or Differential Thermal Analysis,” p. 850.
Examples 1-12 and Comparative Examples C1-C2
In Examples 1-12, using the Simulated Flex-Nip Application Procedure, SSQO silsesquioxane was applied at either 0.1 or 0.3% SOF to either UPBEAT™ nylon 6 carpet or TRANSITION III™ nylon 6,6 carpet. Prior to application, the pH of the treating composition was varied from 7 (as is) or was adjusted to 4 or to 2 by neutralization using 10% aqueous sulfamic acid. The treated carpet was then evaluated for performance using the Water Repellency Test (WR), the Dynamic Water Resistance Test (DWR) (average of two values), and the “Walk-On” Soiling Test (WOS) (one cycle, average of two values).
In Comparative Examples C1 and C2, untreated UPBEAT™ and TRANSITION III™ carpets were evaluated for performance.
Results are presented in TABLE 1.
TABLE 1
WR
(10 point
DWR
WOS
Ex.
% SOF
Carpet
pH
scale)
(g H 2 O)
(ΔE)
1
0.1
UPBEAT
2
0
8.1
1.3
2
0.1
UPBEAT
4
F
15.3
2.8
3
0.1
UPBEAT
7
F
19.9
2.6
4
0.3
UPBEAT
2
0
9.2
0.9
5
0.3
UPBEAT
4
F
19.0
3.4
6
0.3
UPBEAT
7
F
21.3
3.3
C1
untreated
UPBEAT
—
F
20
4.0
7
0.1
T-3
2
F
9.1
2.9
8
0.1
T-3
4
F
21.9
5.3
9
0.1
T-3
7
0 to F
17.4
5.5
10
0.3
T-3
2
F
7.2
2.5
11
0.3
T-3
4
F
22.8
4.9
12
0.3
T-3
7
F
24.1
4.7
C2
untreated
T-3
—
F
20
5.1
The data in TABLE 1 show that both UPBEAT™ T-3 and TRANSITION III™ carpets, when treated with the silsesquioxane treating composition, exhibits superior dynamic water resistance and antisoiling performance when the treating composition has a pH of 2 compared to having a pH of either 4 or 7.
Examples 13-16 and Comparative Examples C3-C7
In Examples 13-16, using the Simulated Flex-Nip Application Procedure, SSQO anionic silsesquioxane was applied at either 0.1 or 0.3% SOF to T3 nylon. Prior to application, the pH of the treating composition was adjusted to 4 or to 2 by neutralizing with 10% aqueous sulfamic acid. The treated carpet was then evaluated for performance using the Water Repellency Test (WR) and the “Walk-On” Soiling Test (WOS) (one cycle, average of two values).
In Comparative Examples C3-C6, the same application and testing procedures were used as in Examples 13-16, except that BAYPROTECT™ AS cationic silsesquioxane was substituted for SSQO anionic silsesquioxane.
In Comparative Examples C7, untreated T3 carpet was evaluated for performance.
Results are presented in TABLE 2.
TABLE 2
WR
%
(10 point
WOS
Ex.
Silsesquioxane
SOF
pH
scale)
(ΔE)
13
SSQO
0.1
2
F
3.0
14
SSQO
0.1
4
F
5.0
15
SSQO
0.3
2
0
1.6
16
SSQO
0.3
4
F
5.2
C3
BAYPROTECT ™ AS
0.1
2
F
3.6
C4
BAYPROTECT ™ AS
0.1
4
F
2.3
C5
BAYPROTECT ™ AS
0.3
2
F
3.5
C6
BAYPROTECT ™ AS
0.3
4
0
1.2
C7
—
—
—
F
6.1
The data in TABLE 2 show that, at the lower pH (2), the anionic silsesquioxane provides superior performance to the cationic silsesquioxane. | This invention relates to a method for imparting soil-resistant and water-repellent properties to fibrous polyamide substrates (such as carpet fibers) by applying an acidic aqueous treating solution containing a silsesquioxane. This invention also relates to the treating solution used to impart soil resistance, and water repellency to the fibrous polyamide. This invention also relates to treated fibrous substrate made according to the method of this invention. | 8 |
TECHNICAL FIELD
The present disclosure relates to semiconductor memory devices, and more particularly, to a semiconductor memory device configured to share a local I/O (input/output) line.
BACKGROUND
A conventional memory core structure minimizes distance between memory cell arrays to maximize memory cell efficiency. In particular, the conventional memory core structure requires a maximum of 16 bits of data outputs, and thus shares a local I/O line.
On the other hand, a high speed memory such as a double data rate (DDR), a DDR-II and a graphic memory outputs a maximum of 32 bits of data. The high speed memory is required to have high speed burst operation, and thus the core must read data as many as a number of the bursts in advance. This function is a prefetch function. The DDR uses 2 bit prefetch and the DDR-II uses 4 bit prefetch. For example, the X16 DDR-II operates at 400MHz with 4 bursts, uses 4 bit prefetch, and reads 64 bits of data by one core access.
However, because the conventional core structure gradually increases an operation speed and widens a bandwidth, it cannot share the local I/O line. As a result, a spatial efficiency cannot be achieved.
SUMMARY OF THE DISCLOSURE
A semiconductor memory device configured to share a local I/O line by sequentially outputting data in a pipeline form is disclosed herein.
The semiconductor memory device includes: a memory cell array including a plurality of memory cells; a plurality of bit line sense amplifiers configured to sense and to amplify data stored in the plurality of memory cells; a plurality of bit lines configured to transmit the data stored in the plurality of memory cells to the plurality of bit line sense amplifiers, respectively; a plurality of bit line dividing circuits configured to selectively divide the plurality of bit lines; and a plurality of column selecting circuits configured to sequentially transmit the data amplified by the plurality of bit line sense amplifiers to corresponding I/O lines.
BRIEF DESCRIPTION OF THE DRAWINGS
The disclosure will be described in terms of several embodiments to illustrate its broad teachings. Reference is also made to the attached drawings.
FIG. 1 is a block diagram illustrating a semiconductor memory device using a pipeline fetch structure; and
FIGS. 2 a and 2 b are timing diagrams of operation signals to explain the operation of the semiconductor memory device of FIG. 1 .
DETAILED DESCRIPTION
The present disclosure will be described in detail with reference to the accompanying drawings.
FIG. 1 is a block diagram illustrating a semiconductor memory device 100 using a pipeline fetch structure. In the semiconductor memory device 100 , a bit line dividing unit 20 is formed at the center portion of a memory cell array 10 composed of a plurality of memory cells 11 , 12 , 13 and 14 . Sense amplifier arrays 30 and 40 composed of a plurality of sense amplifiers with two shown as 31 and 41 , respectively, are connected to both ends of the memory cell array 10 . Here, the bit line dividing unit 20 including NMOS transistors NM 1 , NM 2 , NM 3 and NM 4 that perform switching operation, according to an up bit line switching signal UBL and a down bit line switching signal DBL for dividing bit lines.
In the operation of reading data from memory cells 11 and 12 connected to an enabled word line WLO, the up bit line switching signal UBL is at a low level to turn off the NMOS transistors NM 1 and NM 2 when the data stored in the memory cell 11 connected to the upper sense amplifier array 30 are read. Accordingly, a length of the bit line pair BL and /BL is decreased and a bit line capacitance is reduced, and thereby improving sensing efficiency of the sense amplifiers.
On the other hand, when the data stored in the memory cell 12 connected to the lower sense amplifier array 40 are read, the down bit line switching signal DBL is at a high level to turn on the NMOS transistors NM 3 and NM 4 . The bit line pair BL and /BL of the memory cell 12 positioned in the upper memory cell array 30 of the bit line dividing unit 20 is connected to the lower sense amplifier array 40 . Accordingly, the reading speed of the data stored in the memory cell 11 connected to the upper sense amplifier array 30 is higher than that of the data stored in the memory cell 12 connected to the lower sense amplifier array 40 to sequentially perform the operations for reading the data stored in the two memory cells 11 and 12 . As a result, local I/O line LIO can be shared by using the aforementioned operation property. To illustrate this concept, column selecting units 50 and 60 sequentially transmit the data amplified by the sense amplifiers 31 and 41 to the local I/O line LIO by using a column select signal YI, an up column select signal UYI and a down column select signal DYI.
To read the data from memory cells 11 and 12 , the data stored in the memory cell 11 connected to the upper sense amplifier array 30 are transmitted to a bit line BL 0 . Here, the up bit line switching signal UBL becomes a low level to turn off the NMOS transistors NM 1 and NM 2 .
The data on the bit line BL 0 are sensed and amplified by the bit line sense amplifier 31 . Here, the column select signal YI becomes a high level to turn on NMOS transistors NM 5 and NM 6 . Accordingly, the data amplified by the bit line sense amplifier 31 are transmitted to the local I/O line LIO through a data bus DB. Here, the up column select signal UYI becomes a high level to turn on NMOS transistors NM 9 and NM 10 to form a path for outputting the data amplified by the bit line sense amplifier 31 to the data bus DB.
Thereafter, the data stored in the memory cell 12 connected to the lower sense amplifier array 40 are transmitted to a bit line BL 1 . The down bit line switching signal DBL becomes a high level to turn on the NMOS transistors NM 3 and NM 4 . The data on the bit line BL 1 are sensed and amplified by the bit line sense amplifier 41 . Here, the column select signal YI becomes a high level to turn on NMOS transistors NM 7 and NM 8 .
Therefore, the data are transmitted to the local I/O line LIO through the data bus DB. The down column select signal DYI becomes a high level to turn on NMOS transistors NM 11 and NM 12 to form a path for outputting the data amplified by the bit line sense amplifier 41 to the data bus DB.
Further, the data stored in the memory cell 14 connected to the lower sense amplifier array 40 are transmitted to the bit line BL 1 to read the data from the memory cells 13 and 14 connected to an enabled word line WL 1 . The down bit line switching signal DBL becomes a low level to turn off the NMOS transistors NM 3 and NM 4 .
The data on the bit line BL 1 are sensed and amplified by the bit line sense amplifier 41 . Here, the column select signal YI becomes a high level to turn on the NMOS transistors NM 7 and NM 8 . Accordingly, the data amplified by the bit line sense amplifier 41 are transmitted to the local I/O line LIO through the data bus DB. The down column select signal DYI becomes a high level to turn on the NMOS transistors NM 11 and NM 12 to form a path for outputting the data amplified by the bit line sense amplifier 41 to the data bus DB.
Thereafter, the data stored in the memory cell 13 connected to the upper sense amplifier array 30 are transmitted to the bit line BL 0 . Here, the up bit line switching signal UBL becomes a high level to turn on the NMOS transistors NM 1 and NM 2 . The data on the bit line BL 0 are sensed and amplified by the bit line sense amplifier 31 . The column select signal YI becomes a high level to turn on the NMOS transistors NM 5 and NM 6 .
Therefore, the data are transmitted to the local I/O line LIO through the data bus DB. The up column select signal UYI becomes a high level to turn on the NMOS transistors NM 9 and NM 10 to form a path for outputting the data amplified by the bit line sense amplifier 31 to the data bus DB.
FIGS. 2 a and 2 b are timing diagrams of operation signals to explain the operation of the semiconductor memory device of FIG. 1 . Here, the column select signal YI is inputted with a frequency twice as fast as the general column select signal, and a wave pipe delay time T has a time less than 10 nanoseconds.
FIG. 2 a is a timing diagram of the read operation of the data stored in the memory cells 11 and 12 connected to the enabled world line WL 0 . The data stored in the memory cell 11 connected to the upper sense amplifier array 30 are transmitters the sense amplifier 31 through the bit line pair BL 0 and /BL 0 , and the sense amplifier 31 senses and amplifies the data. The column select signal YI has a high level in a period when the up column select signal UYI is becomes a high level to transmit the data amplified by the sense amplifier 31 to the data bus DB.
Thereafter, the data stored in the memory cell 12 connected to the lower sense amplifier array 40 are transmitted to the sense amplifier 41 through the bit line pair BL 1 and /BL 1 , and the sense amplifier 41 senses and amplifies the data. The column select signal YI has a high level in a period when the down column select signal DYI becomes a high level to transmit the data amplified by the sense amplifier 41 to the data bus DB.
FIG. 2 b is a timing diagram of the read operation of the data stored in the memory cells 13 and 14 connected to the enabled world line WL 1 . The data stored in the memory cell 14 connected to the lower sense amplifier array 40 are transmitted to the sense amplifier 41 through the bit line pair BL 1 and /BL 1 , and the sense amplifier 41 senses and amplifies the data. The column select signal YI has a high level in a period when the down column select signal DYI becomes a high level to transmit the data amplified by the sense amplifier 41 to the data bus DB.
Thereafter, the data stored in the memory cell 13 connected to the upper sense amplifier array 30 are transmitted to the sense amplifier 31 through the bit line pair BL 0 and /BL 0 , and the sense amplifier 31 senses and amplifies the data. The column select signal YI has a high level in a period when the up column select signal UYI becomes a high level to transmit the data amplified by the sense amplifier 31 to the data bus DB.
As mentioned above, efficiency of the core structure is improved with the I/O bandwidth in the high speed memory device by using the pipeline fetch function. Moreover, the semiconductor memory device disclosed herein reduces the bit line capacitance and improves the sensing speed of the sense amplifiers by using the switch element for dividing the bit lines. Thus, the semiconductor memory device sequentially senses the data stored in the memory cells connected to the same word line with the sense amplifiers to share the local I/O line.
Many changes and modifications to the embodiments described herein could be made. The scope of some changes is discussed above. The scope of others will become apparent from the appended claims. | A semiconductor memory device configured to share a local I/O line is described herein. The device includes: a memory cell array including a plurality of memory cells; a plurality of bit line sense amplifiers configured to sense and to amplify data stored in the plurality of memory cells; a plurality of bit lines configured to transmit transmitting the data stored in the plurality of memory cells to the plurality of bit line sense amplifiers, respectively; a plurality of bit line dividing circuits configured to selectively divide the plurality of bit lines; and a plurality of column selecting circuits configured to sequentially transmit the data amplified by the plurality of bit line sense amplifiers to corresponding I/O lines. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to pressurised gas cartridges of the type which may be used in place of conventional pyrotechnic cartridges.
2. History of the Related Art
Pressurised gas cartridges are known, one example being that disclosed in European Patent specification EP-A-499332, to which reference should be made. A disadvantage of the known types of gas cartridges is that they are incapable of generating sufficient rearward force to actuate recoil-operated automatic and semi-automatic weapons. Such weapons depend upon the breech block being moved rearwardly under force applied to it upon firing of a round of ammunition in order to set in train the reloading and recocking cycle.
SUMMARY OF THE INVENTION
To overcome this problem it is proposed herein that a gas cartridge should have a first part which is displaced on firing relative to a second part, so as to apply the necessary force to the breech block to recycle the weapon. In a preferred embodiment, gas used to eject a projectile from the cartridge disclosed in the above mentioned specification is admitted to an expansion chamber prior to being used to eject the projectile, where it acts on the rearwardly movable part.
Preferably the cartridge case is of telescopic construction and has a sleeve which is slidably mounted on a body housing the gas chambers and operating parts. The sleeve may have a forward end wall which overlies the forward end wall of the body, and the expansion chamber is defined between the two end walls. The pressure of gas in the expansion chamber acts on the end wall of the body and drives the body rearwardly in the manner of a piston. The sleeve is held in place by engagement with the wall of the chamber of the weapon. The gas is subsequently discharged from the expansion chamber and used to eject the bullet or other projectile. The moment at which the gas is discharged from the expansion chamber is preferably determined by the sleeve and body entering predetermined relative positions. To this end, the body may have an axially extending spigot which normally projects into and obturates an aperture in the end wall of the sleeve. The relative movement between the sleeve and body leads to the spigot being progressively withdrawn from the aperture until, in the predetermined relative positions, the spigot is withdrawn from the aperture and the gas from the expansion chamber exhausts through it. Although the bullet or other projectile may be held in place to the rim of the sleeve in a conventional way, it may alternatively be fitted to the spigot from which it is released at the instant the pressurised gas is applied to the projectile. Other arrangements for causing a part of a cartridge to be displaced rearwardly may be used in place of that described above.
DESCRIPTION OF THE DRAWING FIGURES
FIG. 1 is a longitudinal section through a pressurised gas cartridge in its charged state prior to firing,
FIG. 2 shows the parts in their relative positions shortly after firing,
FIG. 3 shows the parts in their relative positions at the end of the firing sequence, and
FIG. 4 is a schematic longitudinal cross-section through a portion of a weapon loaded with a gas cartridge according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the invention will be described in the context of the cartridge disclosed in the above-mentioned specification to which reference should be made for a full understanding of the operating mechanism and its manner of operation.
Referring to FIGS. 1 and 4, the cartridge proposed herein has a two-part case formed from a body 10 and a sleeve 14 mounted telescopically on the body. A projectile "P" is disposed at the forward end of the cartridge. In use, the cartridge is loaded into the chamber "C" of a conventional gun having a barrel "A", breech block "B" and firing pin "F", all shown in FIG. 4. The sleeve has a radially inwardly extending wall 16 at its forward end which bounds an aperture 53. Because the cylindrical portion of the sleeve is not under any gas pressure it may have a relatively thin wall. The body is provided at its forward end with an external annular shoulder 54 arranged to cooperate with an internal shoulder 54' at the rearward end of the sleeve in order to limit relative movement of the two parts. An O-ring 55 seals the body to the sleeve at their forward ends.
The body has a radially inwardly extending front wall 33 at its forward end which in the charged state is in close contact with the end wall of the sleeve. An axial spigot 51 projects from the wall 33 and is a sliding fit in the aperture 53. The spigot functions as a slide valve and normally closes the aperture 53. A cavity 35 in the inner side of the wall 33 has a cylindrical portion which serves as a seat for the head 36 of a piston valve having a stem 13. The end wall of the cavity is conical in shape and formed with ports 34 opening into an annular V-sectioned groove in the outer surface of the end wall 33. The groove 60 forms a part of an expansion chamber to be described later. The valve head 36 is formed with a pair of collars 31, 32 defining a groove which receives an O-ring sealing the valve head against the cavity.
An insert 11 is screwed into the rearward end of the body and is sealed relative to the body by an O-ring 15. The insert has a cylindrical extension which defines a bore 20 which guides a skirt portion 57 at the rearward end of the stem 13. A primary gas chamber 21 surrounding the piston valve contains a gas, conveniently air, under a pressure which is preferably at least 50 bar (5×10 7 Pa) and more preferably substantially 200 bar (2×10 7 Pa).
In the charged state of the cartridge as shown in FIG. 1, the body and sleeve are in their closed positions with the two end walls juxtaposed.
Upon the cartridge being fired, the piston valve is moved rearwardly, initially into the position shown in FIG. 2. The valve head 36 is therefore withdrawn from the cavity 35 and frees the ports 34. Gas from the primary chamber escapes into the groove 60 and causes the body to begin its rearward movement relative to the sleeve. This movement begins the enlargement of an expansion chamber 61 which continues to enlarge as rearward movement of the body continues. Gas is prevented from escaping between the body and sleeve by the O-ring 55. During this movement the spigot slides back through the aperture 53 until eventually it is withdrawn completely therefrom into the position shown in FIG. 3. The air from the expansion chamber now escapes through the aperture 53 and ejects the projectile "P" carried by the cartridge. The projectile "P" may be held in place by a lip on the rim of the wall 16, or may be provided with a socket "S" which receives the spigot 51. In the charged state of the cartridge as shown in FIG. 1, the body and sleeve are in their closed positions with the two end walls juxtaposed.
The operating mechanism for the cartridge is substantially as described in the above-mentioned specification and will therefore be described only briefly.
The rearward movement of the piston valve is initiated by displacement of a relief valve which comprises a spool member supported within the skirt 57 of the piston valve. The spool member has a central body portion 12 and forward and rearward shoulders 42, 43 defining grooves for receiving O-rings 40, 41. A stem portion 45 extends rearwardly from the shoulder 43 and is located within a relief passage 23. Frusto-conical valve seats 44 in the relief passage 23 are contacted by a complementary portion of the rearward shoulder and by the rearward O-ring. The forward O-ring 40 is sealed against the bore within the skirt 57. A compression spring 50 applies a relatively weak pressure to the spool member. Two chambers are thereby formed, namely a secondary chamber 22 located between the end of the skirt 57 and the seal ring 41 and third chamber 47 located within the skirt 57 forwardly of the shoulder 42. The chamber 22 is in communication with the primary chamber 21 through a bleed passage 24 existing between the skirt and the bore 20, so that in the charged state the pressures within the chambers 21 and 22 are equalised. A duct 46 extends through the spool member to connect the chamber 47 to a vent in the peripheral surface of the stem portion, whereby the chamber 47 is at atmospheric pressure.
Upon the stem portion 45 being struck by a firing pin "F" moving in the direction of the arrow "A", the spool member is propelled into the skirt, so lifting the rearward shoulder 43 and O-ring 41 from their seats.
Gas in the chamber 22 vents to atmosphere through the relief passage. Although some gas flows through the bleed passage 24 from chamber 21, this flow is negligible and does not prevent the pressure in the chamber 22 falling sharply. The gas in chamber 21 applies pressure to the forward surface of the skirt 57 which greatly overcomes that applied by gas in chamber 22 to the rearward rim of the skirt, and the piston valve tends to move rearwards, as discussed above. Because chamber 47 is at atmospheric pressure and able to vent through duct 46, the spool member is drawn into the skirt, thereby allowing the piston valve to move towards the position shown in FIG. 3.
By varying the length of the spigot 51 or the length of the body of the cartridge or the ratio of the former to the latter, the time at which gas is released and the projectile discharged may be adjusted relative to the rearward motion of the body.
A cartridge in accordance with the invention has the advantage over pyrotechnic cartridges that it is reusable. It is therefore very suitable for use as training ammunition, particularly for semi-automatic pistols and other recoil-operated weapons. The cartridge may also be particularly suitable for use in paint-ball guns, because the ball may be adapted easily to fit on the spigot 51. Although the cartridge has been described as being used to eject a projectile, it will be appreciated that it may be used as a "blank" without a projectile but will still be capable of applying force to the breech block "B".
Modifications may be made to the cartridge described herein within the scope of the invention. In particular, other types of valve arrangements may be employed to admit gas to the expansion chamber in response to the cartridge being struck by the firing pin, and other valve arrangements may be used to discharge gas from the expansion chamber and the desired instant. | A cartridge has a case comprising a body (10) housed telescopically within a sleeve (14). The body encloses a main chamber (21) which contains gas under pressure, and a valve mechanism for venting gas from the chamber (21) into an expansion chamber (61). The pressure of the gas in the expansion chamber causes the body (10) to move rearwardly relative to the sleeve (14) to apply a force to the breech block of the weapon in which the cartridge is used, thereby to initiate the reloading cycle. Gas is vented from the expansion chamber to eject a projectile when a spigot (51) projecting from the body is withdrawn from an aperture (53) in the end wall of the sleeve. | 5 |
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