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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a phase selector, and more particularly, to a phase selector with the functionality of deciding a phase of an output clock to trigger a flip-flop by comparing phases of an input data signal and an input clock.
2. Description of the Prior Art
In digital circuits, clock signals are essential reference signals for accessing digital data. Typically, latch time for accessing digital data in digital circuits is determined using either rising edge or falling edge triggers. In some cases, even though two different sub-circuits in a circuit system utilize exactly the same clock source, clocks and digital data transmitted to the sub-circuits may be asynchronous due to transmission delay or noise interference.
Take a transmitting device comprising two flip-flops as an example herein. Please refer to FIG. 1 and FIG. 2 . FIG. 1 is a schematic diagram illustrating digital data transmitted between two flip-flops 110 and 120 . FIG. 2 is a timing diagram illustrating clocks and digital data in FIG. 1 . An input data signal D 1 and a clock C 1 are used herein as inputs to the flip-flop 110 , having waveforms and timing relation shown in FIG. 2 . Assume that both flip-flops 110 and 120 are rising edge triggered, thus the input data signal D 1 will be latched at t 1 , the flip-flop 110 will output latch data D L to the flip-flop 120 , and the latch data D L will have a transition from “0” to “1” from t 1 , as shown in FIG. 2 . Clocks C 1 and C 2 respectively for the two flip-flops 110 and 120 are asynchronous. Therefore, if a rising edge trigger of the clock C 2 happens at t 2 during the period when the latch data D L is changing from “0” to “1” as shown in FIG. 2 , latch errors will be induced in the flip-flop 120 , resulting in errors in digital data transmission.
SUMMARY OF THE INVENTION
It is therefore one of the objectives of the present invention to provide a phase selector and a related clock selection method for generating an appropriate reference clock in data transmitting device, thus improving the accuracy of reading/writing data.
According to one embodiment of the present invention, the present invention discloses a phase selector, for outputting an output clock to a flip-flop according to an input data signal latched by the flip-flop, the phase selector comprising: a clock phase adjustor, for adjusting the delay of an input clock to generate a first clock and a second clock, wherein the clock phases of the first clock and the second clock are different; a phase detector, for detecting phase relation between the input data signal and the first clock to generate a detecting signal; a decision circuit, coupled to the phase detector, for generating a selecting signal according to the detecting signal; and a selection circuit, coupled to the decision circuit, for selecting the input clock or the second clock to generate the output clock to the flip-flop according to the selecting signal.
According to another embodiment of the present invention, the present invention discloses a data transmitting device, comprising: a first flip-flop, for latching an input data signal to output a data signal according to a first clock; a second flip-flop, coupled to the first flip-flop, for latching the data signal to output an output data signal according to an output clock; and a phase selector, coupled to the first flip-flop and the second flip-flop, for generating the output clock to the second flip-flop according to phase relation between the data signal and a second clock; wherein the frequency of the output clock is substantially equal to the frequency of the second clock.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram illustrating digital data transmitted between two flip-flops according to the prior art.
FIG. 2 is a timing diagram illustrating clocks and digital data in FIG. 1 .
FIG. 3 is a schematic diagram illustrating a data transmitting device with a phase selector.
FIG. 4 is a timing diagram illustrating clocks and digital data in FIG. 3 .
FIG. 5 is a schematic diagram illustrating an embodiment of a phase selector of the present invention.
FIG. 6 is a schematic diagram illustrating the phase selector in FIG. 5 in detail.
FIG. 7 is a truth table of related signals in FIG. 6 .
DETAILED DESCRIPTION
Please refer to FIG. 3 and FIG. 4 . FIG. 3 is a schematic diagram illustrating a data transmitting device with a phase selector 330 of the present invention. FIG. 4 is a timing diagram illustrating clocks and digital data in FIG. 3 . As shown in FIG. 3 , the phase selector 330 determines whether a phase of a clock C 2 needs to be delayed to generate a delay clock C 3 according to a latch data D L . Therefore, the delay clock C 3 with a relatively delayed phase can be used to latch bit values of the latch data D L accurately. For example, in FIG. 4 , the phase selector 330 delays the clock C 2 for a half-period, i.e. 180 degrees of phase. A rising edge trigger of the delay clock C 3 occurs at t 3 for a flip-flop 320 to latch the latch data D L . Distinct from the clock C 2 with no delay ( FIG. 2 ), the delay clock C 3 with a relatively delayed phase ( FIG. 4 ) can latch bit values of the latch data D L accurately. In practical embodiments, the delay amount applied to the clock C 2 can be programmable by circuit designers. In other words, the clock C 2 can be delayed for a delay amount other than a half-period if appropriate. Accordingly, in one embodiment of the present invention, the flip-flop 310 is positioned in an analog signal domain, and the flip-flop 320 is positioned in a digital signal domain. In such a case, a signal D 1 is outputted from an analog circuit, and a signal D 0 is outputted to a digital circuit. In other embodiments, the flip-flop 310 can be positioned in a digital signal domain, and the flip-flop 320 can be positioned in an analog signal domain. In such a case, the signal D 1 is outputted from a digital circuit, and the signal D 0 is outputted to an analog circuit. Please note that the two above examples are not meant to be a limitation of the present invention.
FIG. 5 is a schematic diagram illustrating an embodiment of a phase selector 500 of the present invention. The phase selector 500 comprises a clock phase adjustor 515 , a phase detector 510 , a decision circuit 590 , and a selection circuit, such as a multiplexer 570 . The clock phase adjustor 515 comprises a first delay unit 550 and a second delay unit 560 . The decision circuit 590 comprises a first counter 520 , a second counter 530 , and a control circuit 505 . The control circuit 505 comprises a selection circuit 540 and a latch circuit 580 .
The first delay unit 550 delays an input clock C 2 for some degree of phase delay to generate a first delay clock C D1 . Because the phase detector 510 detects that a phase of an input data signal D L lags behind that of the first delay clock C D1 , a detecting signal S 1 remains at a logic level “0”, and another detecting signal S 2 is a continuous square wave. If the phase of the input data signal D L leads that of the first delay clock C D1 , the detecting signal S 1 is a continuous square wave, and the detecting signal S 2 remains at the logic level “0”. The selection circuit 540 decides whether a selecting signal S W is output to switch the multiplexer 570 according to the detecting signals S 1 and S 2 . In one preferred embodiment that can prevent an erroneous switching operation of the multiplexer 570 , the decision circuit 590 receives the detecting signals S 1 and S 2 via the first and second counters 520 and 530 respectively and thus outputs the selecting signal S W ; and the second delay unit 560 delays the input clock C 2 for some degree of phase delay to generate a second delay clock C D2 . The multiplexer 570 then selects the input clock C 2 or the second delay clock C D2 to be an output clock C 3 according to the selecting signal S W . In other words, the selecting signal S W for controlling the multiplexer 570 is decided according to phase relation between the input data signal D L and the first delay clock C D1 . When the phase of the input data signal D L leads that of the first delay clock C D1 , the multiplexer 570 selects the input clock C 2 as the output clock C 3 . When the phase of the input data signal D L lags behind that of the first delay clock C D1 , however, the multiplexer 570 selects the second delay clock C D2 as the output clock C 3 .
Moreover, after the selection circuit 540 sends the selecting signal S W to switch the multiplexer 570 , the latch circuit 580 will send a disable signal S DIS to the selection circuit 540 . The disable signal S DIS thus stops the selection circuit 540 from switching the multiplexer 570 , thereby avoiding system instability due to frequent switching operations. After the selection circuit 540 is stopped for an appropriate period of time, the latch circuit 580 will send an enable signal S EN to restart the selection circuit 540 .
FIG. 6 is a schematic diagram illustrating the phase selector in FIG. 5 in detail. As shown in FIG. 6 , the phase selector 600 comprises a Bang-Bang phase detector 610 , a first counter 620 , a second counter 630 , an AND gate 640 , a delay circuit 650 , a NOR gate 660 , a multiplexer 670 , a NOT gate 680 , and an OR gate 690 . The AND gate 640 , the NOR gate 660 , and the OR gate 690 form a control circuit 605 . The delay circuit 650 delays an input clock C 2 for a quarter-period, i.e. 90 degrees of phase, to generate a first delay clock C D1 . The NOT gate 680 inverts the input clock C 2 to generate a second delay clock C D2 . In other words, the NOT gate 680 delays the input clock C 2 for 180 degrees of phase. The second delay clock C D2 is thus sent to the multiplexer 670 . If a phase of an input data signal D L leads that of the first delay clock C D1 , a detecting signal S 1 is a continuous square wave, and another detecting signal S 2 remains at a level “0”. Moreover, when a square wave number (i.e. a pulse number) of the detecting signal S 1 counted by the first counter 620 reaches a threshold value, the phase of the input data signal D L will lead that of the first delay clock C D1 . Therefore, the first counter 620 outputs a first selecting signal S W1 at a logical level “1”. Because the detecting signal S 2 remains at the level “0”, a square wave number of the detecting signal S 2 counted by the second counter 630 is zero. Thus, the second counter 630 outputs a second selecting signal S W2 at a logical level “0”. In such a case, the multiplexer 670 selects the input clock C 2 as an output clock C 3 . Otherwise, the multiplexer 670 selects the second delay clock C D2 as the output clock C 3 . The first and second selecting signals S W1 and S W2 are input into the NOR gate 660 to generate a disable signal S DIS . The disable signal S DIS and an enable signal S EN are input into the OR gate 690 to generate a reset signal S R . Further, the reset signal S R and the first delay clock C D1 are input into the AND gate 640 to generate a control signal S C for controlling the first and second counters 620 and 630 . After Boolean calculation, the relation between the control signal S C and other signals can be represented as follows:
S C =C D1 [S EN +( S W1 +S W2 )′].
FIG. 7 is a truth table 700 of the first selecting signal S W1 , the second selecting signal S W2 , the disable signal S DIS , the enable signal S EN , the reset signal S R , the first delay clock C D1 , and the control signal S C . As shown in FIG. 7 , when square wave numbers counted by the first and second counters 620 and 630 are below the threshold value, the first and second selecting signals S W1 and S W2 are both logically “0”. Meanwhile, the disable signal S DIS is “1”, thus the reset signal S R is certain to be “1”. Because the first delay clock C D1 is a clock signal, the control signal S C is also a clock signal serving as a reference clock for the first and second counters 620 and 630 . In other words, the first and second counters 620 and 630 continue to count the square wave numbers. When either square wave number reaches the threshold value, the corresponding selecting signal (i.e. the first selecting signal S W1 or the second selecting signal S W2 ) changes to be logically “1”. The disable signal S DIS thus becomes logically “0”. Meanwhile, if the enable signal S EN is not available, i.e. logically “0”, the reset signal S R becomes logically “0”, and the control signal S C also becomes logically “0”. Therefore, the reference clock for the first and second counters 620 and 630 is “0”, so the first and second counters 620 and 630 stop counting the square wave numbers. Additionally, the counters act as memories to store the results of the selecting signals S W1 and S W2 . When the enable signal S EN is available, i.e. logically “1”, the reset signal S R becomes logically “1”, and the control signal S C is a clock signal again. The counters are reset to “0” at rising edges of the enable signal S EN . In the above described way, the control circuit 605 formed by the NOR gate 660 , the OR gate 690 , and the AND gate 640 is utilized to avoid system instability due to frequent switching operations of the output clock C 3 .
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims. | A phase selector is disclosed. The phase selector is utilized for outputting an output clock to a flip-flop according to an input data signal latched by the flip-flop. The phase selector includes: a clock phase adjustor, for adjusting the delay of an input clock to generate a first clock and a second clock, wherein the clock phases of the first clock and the second clock are different; a phase detector, for detecting phase relation between the input data signal and the first clock to generate a detecting signal; a decision circuit, coupled to the phase detector, for generating a selecting signal according to the detecting signal; and a selection circuit, coupled to the decision circuit, for selecting the input clock or the second clock to generate the output clock to the flip-flop according to the selecting signal. | 7 |
FIELD
[0001] This invention generally relates to the testing and evaluation of underground formations or reservoirs. More particularly, this invention relates to maximizing fluid pumping output capacity in situations where limited electrical power is available downhole and where space is also limited as a result of a need for reduced diameter testing tools.
BACKGROUND
[0002] Wells drilled into the ground to recover deposits of oil, gas or other desirable minerals trapped in geological formations often need to be evaluated as to the presence and particular characteristics of those deposits or as to the characteristics of the formations in which those deposits are found. After the presence of such deposits has been confirmed and a portion has been produced, additional evaluations may be performed to determine the quantity and condition of that portion of the original deposit remaining within the geological formation.
[0003] One technique for evaluating deposits and formations is to lower an evaluation tool into the well on a wireline. The purpose of some wireline tools is to measure the pressure characteristics of the formation and to retrieve a fluid sample for later analysis in a laboratory. These wireline tools have come to be known as Wireline Formation Testers or WFT's. Other methods of conveyance also exist. The term Drill Stem Testing or DST is frequently used when drill pipe or coiled tubing is used to convey the formation test tool into the well. WFT's and DST's may employ pumps to withdraw fluids from the formation or to inject fluids into the formation.
[0004] WFT's can be conveyed on a variety of different types of wireline with some standards for wireline sizes and for the number of electrical conductors having developed within the industry. Wireline sizes typically vary from 0.100 inches to 0.520 inches outer diameter, containing between 1 and 7 internal conductors. Normally two layers of external steel armour surround the conductors to provide protection and strength.
[0005] Wireline design options are constrained in several respects. The wireline must be able to fit on a spool that is capable of being mounted on a truck or on a portable skid unit. The spool itself must accommodate a sufficient length of wireline to reach the bottom of deep wells. Together, these two requirements determine a maximum possible diameter for a continuous portable wireline of any given length.
[0006] Another requirement is that the wireline must be strong enough to support its own weight, in addition to the weight of the tools to be conveyed plus an allowance for over pull in the event that the tools become subjected to frictional sticking forces. This requirement works to increase the amount of steel armour and therefore to decrease the amount of space available for the internal electrical conductors and insulating materials.
[0007] Another requirement is for high voltage ratings between the conductors and ground, as well as between the conductors themselves, if a plurality of conductors is desired. This requirement tends to increase the thickness of the insulating material that surrounds the conductors, further decreasing the amount of space available for the conducting material. Finally, the current carrying capacity of wireline increases with the diameter of the conducting material and electrical power is the product of voltage times current.
[0008] When considered together, the aforementioned design requirements all work to place an upper limit on the amount of power that can be conveyed downhole via a portable wireline. Because power downhole is necessarily in limited supply, it is prudent to make the most efficient possible use of that power which is available, particularly in those instances where the wireline tool is expected to perform mechanical work.
[0009] Conventional wirelines were first developed before the existence of WFT's and at a time when electronic technology was not in the advanced state it is today. The 7-conductor (heptacable) wireline which has become fairly standard for openhole wireline operations provided early tool designers with a plurality of signal pathways that enabled several measurements to be transmitted to the surface concurrently. Today, the need for multiple signal pathways is reduced or eliminated by the use of telemetry communications between the downhole tools and the surface equipment.
[0010] First generation WFT's did not provide for direct continuous pumping of formation fluids or of borehole fluids. Pressure drawdown measurements were made indirectly using pressurized hydraulic fluid to drive pre-test pistons moving within chambers or test-volumes. Continuous pumping capacity was not a design consideration, so that standard heptacable wireline was adequate for the purpose and hydraulic fluid pumping efficiencies were not of great concern.
[0011] While some second generation of WFT's tools do provide for direct continuous pumping of formation and of borehole fluids, the use of pressurized hydraulic fluid actuation continues. In these newer tools, the pressurized hydraulic fluid is often employed to actuate reciprocating downhole pumps, commonly referred to as mud-pumps, in addition to actuating pre-test pistons within pre-test volumes.
[0012] Hydraulic systems are known to be inherently inefficient. The overall efficiency of a hydraulic system can be calculated as the product of the individual efficiencies of all of the system components. These components necessarily include a hydraulic fluid pump with both mechanical and volumetric losses, in addition to piping, valves and other sources of frictional loss that cause heat generation in the hydraulic fluid. These hydraulic losses further diminish an already limited amount of downhole power that can be delivered to the mud-pump.
[0013] A second disadvantage of hydraulic actuation is the lack of ability to directly determine the position of the component being actuated. First generation WFT's employed pre-test designs with fixed volume chambers to address this limitation. Some second generation WFT's employing hydraulic actuation techniques require complex sensing apparatus to determine pre-test volumes or to control mud-pump through-put volumes. Frequently, this lack of ability to accurately control the volume of fluid being pumped has resulted in tool designs that continue to include pre-test volume capabilities, even though this is approach is functionally redundant in combination with a mud-pump.
[0014] A third disadvantage of hydraulically actuated mud-pumps is that the best commercially available axial piston pumps to pressurize hydraulic fluid do not provide adequate output volumes in the small diameter sizes that would be required to manufacture a high mud-pump capacity WFT of a small enough diameter to be suitable for slim boreholes. In this case it is hydraulic fluid output capacity that may become the overall limiting design constraint.
[0015] A fourth disadvantage of hydraulically actuated mud-pumps is that inherent design difficulties exist in routing power and communication links through the electric motor and hydraulic pump sub-assembly. While hollow-shafted electric motors are commercially available, hollow bore hydraulic pumps are neither commercially available nor conceptually practical to design. For hydraulically actuated mud-pump designs, this restriction necessitates the routing of power and communication links around the outside of the electric motor and hydraulic pump sub-assembly. This in turn limits the maximum outer diameter of the motor and hydraulic pump sub-assembly, reducing its potential output power, as well as greatly complicating overall assembly and maintenance tasks. While this maximum outer diameter constraint may be mitigated by routing some of the power and communication lines through the motor stator windings rather than around the outside of the motor, such approach introduces additional difficulties due to line cross-talk and transient noise from motor switching, while it further increases assembly and maintenance complexity.
[0016] Some of the other limitations of the currently available WFT's are described in the literature. WO97/08424 teaches a method of well testing and intervention that combines wireline with coiled tubing to overcome the fluid injection and discharge limitations of conventional WFT's. While the method in WO970848 might be an effective option, it is complex, costly and time consuming due to the need for large amounts of specialty surface equipment.
[0017] A second example of a limitation of existing WFT mud-pumps can be found in U.S. Pat. No. 7,395,703, which teaches the use of a complex system of controls to overcome the limitations of pre-tests that are performed in variable test volumes. U.S. Pat. No. 7,395,703 does not indicate how such pre-testing might be done as part of a continuous, rather than a discrete process.
[0018] A third example of a limitation of existing WFT mud-pumps can be found in U.S. Pat. No. 6,964,301, which teaches a method of formation sampling that uses two separate flow pathways. The first flow pathway is used to collect the sample while the second flow pathway, concentric around the first flow pathway at the inlet port, acts as a guard to limit the amount of drilling fluid filtrate entering into the first flow pathway. The intent of this arrangement is to minimize contamination of formation fluid samples. While this scheme might be partially effective, such a complex arrangement would not likely be necessary if a mud-pump of sufficient capacity were employed to ensure adequate cleanup of drilling fluid filtrate in the invaded zone prior to collecting the sample.
[0019] A recent patent which discloses formation testing while connected to a pipe string, instead of a wireline, is U.S. Pat. No. 7,594,541 (Ciglenec et al) entitled “Pump Control for Formation Testing”.
[0020] What is still needed, therefore, are simple downhole pumping techniques which make optimum use of the limited amount of power that can be supplied over wireline cables, while providing higher capacity output with pumping characteristics that are inherently useful for WFT's and that are designed in ways that make them amenable to deployment in smaller diameter formation test tools.
SUMMARY
[0021] There is provided a high efficiency fluid pumping apparatus and methods having of an electronic motor controller controlling at least one electric motor that is directly coupled to the input of a hollow helical mechanism. The output of the hollow helical mechanism is directly coupled to the shaft of a reciprocating piston pump. Each moving component of the apparatus is designed with a hollow central bore, so that the apparatus assembly will accept a continuous, stationary, hollow conduit containing electrical through wiring and or fibre optics for power and communication to devices physically positioned below the apparatus. Check valves are provided to allow for pump intake and exhaust strokes and a 4-way valve is provided to permit the sources of the pump intake and exhaust to be reversed.
[0022] In some embodiments the invention relates to a wireline formation test tool that includes a high efficiency downhole fluid pump. The wireline formation tester may be of a small diameter such as 3⅜″ outer diameter, or even smaller.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] These and other features will become more apparent from the following description in which reference is made to the appended drawings. These drawings are for the purpose of illustration only and are not intended to be in any way limiting, wherein:
[0024] FIG. 1 is a schematic cross-sectional view of one embodiment of a wireline formation test tool in which the present invention may be used.
[0025] FIG. 2 is a schematic cross-sectional view of an alternative embodiment of a wireline formation test tool in which the present invention may be used.
[0026] FIG. 3 a is a is a schematic view of the electric motor section 300 of the embodiments of the wireline formation test tools of FIG. 1 and FIG. 2 .
[0027] FIG. 3 b is a schematic cross-sectional view of the electric motor section 300 of the embodiments of the wireline formation test tools of FIG. 1 and FIG. 2 .
[0028] FIG. 4 a is a schematic cross-sectional view of the hollow helical mechanism section 400 of the embodiments of the wireline formation test tools of FIG. 1 and FIG. 2 , shown at the upper limit of the range of its travel.
[0029] FIG. 4 b is a schematic cross-sectional view of the hollow helical mechanism section 400 of the embodiments of the wireline formation test tools of FIG. 1 and FIG. 2 , shown at the lower limit of the range of its travel.
[0030] FIG. 5 a is a schematic cross-sectional view of the reciprocating piston pump section 500 of the embodiments of the wireline formation test tools of FIG. 1 and FIG. 2 , shown at the upper limit of the range of its travel.
[0031] FIG. 5 b is a schematic cross-sectional view of the reciprocating piston pump section 500 of the embodiments of the wireline formation test tools of FIG. 1 and FIG. 2 , shown at the lower limit of the range of its travel.
[0032] FIG. 6 shows a method in accordance with one embodiment of the invention.
[0033] FIG. 7 a is a schematic cross-sectional view of an embodiment of a planetary roller screw with a hollow central bore.
[0034] FIG. 7 b is a schematic cross-sectional view of an embodiment of a recirculating roller screw with a hollow central bore.
[0035] FIG. 7 c is a schematic cross-sectional view of an embodiment of a lead screw with a hollow central bore.
DETAILED DESCRIPTION
[0036] In one or more embodiments, the invention relates to a high efficiency fluid pump that may be used in a downhole tool for formation evaluation or for well stimulation purposes. In some embodiments, the invention relates to methods for using a high efficiency fluid pump. In one or more embodiments, the invention relates to a wireline formation evaluation tool that includes a high efficiency fluid pump. The invention will now be described with reference to FIG. 1 through FIG. 7
Structure and Relationship of Parts:
[0037] FIG. 1 shows one embodiment of the invention that relates to a wireline formation evaluation tool 100 that includes a high efficiency fluid pump. A borehole 101 is shown to have penetrated two impermeable geological formations 102 , in addition to a permeable geological formation 103 . In order to evaluate the reservoir characteristics of the permeable formation 103 , the wireline formation evaluation tool 100 is conveyed into borehole 101 , via wireline 110 , so that an upper hydraulic isolation packer 160 is positioned above the permeable formation 103 and a lower hydraulic isolation packer 162 is positioned below the permeable formation 103 . The spacing between the upper and lower packers may vary. The packers are shown in their activated position, where their sealing elements have been brought into contact with the borehole wall, in order to provide fluid isolation of the interval of the borehole between the packers.
[0038] The wireline formation evaluation tool 100 further comprises an electronics section that includes a motor controller 120 ; an electrical motor section 300 that is more fully described in FIG. 3 a and FIG. 3 b ; a hollow helical mechanism section 400 that is more fully described in FIG. 4 a and FIG. 4 b ; a pump section 500 that is more fully described in FIG. 5 a and FIG. 5 b ; an optional fluid sampling section 130 ; a fluid property measurement section 140 ; and an optional well stimulation fluid carrier section 170 .
[0039] A first internal fluid pathway is connected to a 4-way valve 503 and passes through internal components, devices and valves appropriate to the optional tool configurations being employed. The first internal fluid pathway may be connected to a first external fluid port 161 , placing it in fluid communication with the isolated interval of borehole between the isolation packers, or in the alternative it may be connected to an internal chamber in the optional fluid sampling section 130 or to an internal chamber in the optional well stimulation fluid carrier section 170 . By changing the 4-way valve setting, the first internal fluid pathway can either be connected to the high efficiency fluid pump intake 501 or it can be connected to the high efficiency fluid pump exhaust 502 . A second internal fluid pathway is connected to the 4-way valve 503 and passes through internal tool components, devices and valves appropriate to the optional tool configurations being employed. The second internal fluid pathway may be connected to a second external fluid port 141 , placing it in fluid communication with the borehole annulus above upper hydraulic isolation packer 160 , or in the alternative it may be connected to an internal chamber in the optional fluid sampling section 130 or to an internal chamber in the optional well stimulation fluid carrier section 170 . Construction of the 4-way valve 503 is such that the second internal fluid pathway is connected to either the high efficiency fluid pump intake 501 or to the high efficiency fluid pump exhaust 502 , but in a manner opposite to that of the first internal fluid pathway.
[0040] FIG. 2 shows an alternative embodiment of the invention that relates to a wireline formation evaluation tool 200 that includes a high efficiency fluid pump. A borehole 101 is shown to have penetrated two impermeable geological formations 102 , in addition to a permeable geological formation 103 . In order to evaluate the reservoir characteristics of the permeable formation 103 , a wireline formation evaluation tool 200 is conveyed into borehole 101 , via wireline 110 , so that a probe 250 is positioned at a point within the interval of the permeable formation 103 .
[0041] The probe is shown in its extended position, where the sealing element has been brought into contact with the borehole wall, in order to provide fluid isolation of a small, essentially circular area of the borehole. The probe 250 is held firmly against the wall of the borehole by a backup arm or similar device 252 , also shown in the extended position.
[0042] The wireline formation evaluation tool 200 further comprises an electronics section that includes a motor controller 120 ; an electrical motor section 300 that is more fully described in FIG. 3 a and FIG. 3 b ; a hollow helical mechanism section 400 that is more fully described in FIG. 4 a and FIG. 4 b ; a pump section 500 that is more fully described in FIG. 5 a and FIG. 5 b ; an optional fluid sampling section 130 ; a fluid property measurement section 140 ; and an optional well stimulation fluid carrier section 170 .
[0043] A first internal fluid pathway is connected to a 4-way valve 503 and passes through internal components, devices and valves appropriate to the optional tool configurations being employed. The first internal fluid pathway may be connected to a first external fluid port 251 , placing it in fluid communication with the isolated interval of borehole at the tip of the probe 250 , or in the alternative it may be connected to an internal chamber in the optional fluid sampling section 130 or to an internal chamber in the optional well stimulation fluid carrier section 170 . By changing the 4-way valve setting, the first internal fluid pathway can either be connected to the high efficiency fluid pump intake 501 or it can be connected to the high efficiency fluid pump exhaust 502 . A second internal fluid pathway is connected to the 4-way valve 503 and passes through internal tool components, devices and valves appropriate to the optional tool configurations being employed. The second internal fluid pathway may be connected to a second external fluid port 141 , placing it in fluid communication with the borehole annulus, or in the alternative it may be connected to an internal chamber in the optional fluid sampling section 130 or to an internal chamber in the optional well stimulation fluid carrier section 170 . Construction of the 4-way valve 503 is such that the second internal fluid pathway is connected to either the high efficiency fluid pump intake 501 or to the high efficiency fluid pump exhaust 502 , but in a manner opposite to that of the first internal fluid pathway.
[0044] FIG. 3 a is a schematic view of one embodiment of an electrical motor section 300 . FIG. 3 b is a corresponding schematic cross-sectional view of the same embodiment of an electrical motor section 300 . Other embodiments comprising at least one electrical motor are possible. Referring to FIG. 3 b , an upper electrical motor 310 is comprised of a hollow motor shaft 312 , a permanent magnet rotor 313 and an electrically wound stator 314 . Similarly, a lower electrical motor 320 is comprised of a hollow motor shaft 322 , a permanent magnet rotor 323 and an electrically wound stator 324 . The upper hollow motor shaft 312 is mechanically coupled to the lower hollow motor shaft 322 by a hollow shaft coupler 315 . The mechanical output of the electrical motor section 300 is coupled to a hollow helical mechanism section 400 that is more fully described in FIG. 4 a and FIG. 4 b , via a hollow shaft spider-coupler 330 and a hollow détente-ball torque limiter 340 . A hollow tubular conduit 350 is provided for electrical wiring and fibre optic connections of any devices positioned below the electrical motor section 300 . Construction of electrical motor section 300 is such that a single rotational position resolver 311 is able to provide rotational position feedback for both the upper electrical motor 310 and the lower electrical motor 320 . It will be recognized by those skilled in the art that this control arrangement can be easily extended to control a plurality of motors.
[0045] FIG. 4 a is a schematic cross-sectional view of an embodiment of a hollow helical mechanism section 400 , shown at the upper limit of the range of its travel. FIG. 4 b shows the same embodiment of a hollow helical mechanism section 400 at the lower limit of the range of its travel. A hollow helical screw 410 is held in position by roller bearings 411 and by roller thrust bearings 412 . A helical nut assembly 413 is prevented from rotating by guide sleeve 414 but is free to travel along the length of the hollow helical screw 410 . The internal central bore of the hollow helical mechanism 400 is designed to accept a hollow tubular conduit containing electrical wiring and fibre optic connections for any devices positioned below the hollow helical mechanism section. A hollow sleeve 415 and a hollow coupler 416 move with the helical nut assembly 413 , providing a means for connection to the reciprocating piston pump section that is more fully described in FIG. 5 a and FIG. 5 b.
[0046] FIG. 5 a is a schematic cross-sectional view of an embodiment of a reciprocating piston pump section 500 , shown at the upper limit of the range of its travel. FIG. 5 b shows the same embodiment of a reciprocating piston pump section 500 , at the lower limit of the range of its travel. Pump body 501 forms a core upon which two intake check valves 523 and two exhaust check valves 513 are mounted. Each intake check valve 523 comprises an intake piston 520 , an intake piston seal 521 , and an intake return spring 522 . Fluid intake is provided via an intake fluid tube 524 and low profile intake elbow 525 . Each exhaust check valve 513 comprises an exhaust piston 510 , an exhaust piston seal 511 , and an exhaust return spring 512 . Fluid exhaust is provided via an exhaust fluid tube 514 and low profile exhaust elbow 515 . A reciprocating piston shaft 551 is disposed within the bore of a pressure tube 550 and provides a means of mounting for a piston assembly 540 and two opposing piston seals 541 . Both ends of the reciprocating piston shaft 551 are constrained to run through seal assemblies 530 and opposing rod seals 531 . A hollow tubular conduit 552 is provided for electrical wiring and fibre optic connections of any devices positioned below the reciprocating piston pump section 500 .
[0047] FIG. 6 shows a method for operating a fluid pumping system 600 in accordance with one embodiment of the invention. The method first includes providing a downhole motor controller 601 with a desired motor torque reference value 602 or alternatively with a range of motor torque reference values. Similarly, the method includes providing the downhole motor controller 601 with a desired motor speed reference 603 or alternatively with a range of motor speed reference values. Utilizing the desired values for motor torque and motor speed, in conjunction with motor rotational position data supplied by the rotational position resolver 311 , the motor controller adjusts the characteristics of the power supplied to the electric motor section 300 . After taking into consideration the individual efficiencies of the electric motor section 300 , the hollow helical mechanism section 400 , and the reciprocating piston pump section 500 , precise control of desired pumping characteristics can be achieved. This arrangement eliminates any need of additional feed-back control loops such as those based on pump output pressure measurement or based on pump piston displacement measurement. In one embodiment, motor torque is held constant by the motor controller 601 , while motor speed is controlled within an acceptable range of values. After including calculated allowances for the efficiencies of all components of the high efficiency assembly 610 , this method of fluid pump control has the effect of providing control over pump output pressure within the range of the capacity of the pump, and without the need to measure pump output pressure directly. In a second embodiment, motor speed is held constant by the motor controller 601 , while motor torque is controlled within an acceptable range of valves. After including calculated allowances for the efficiencies of all components of the high efficiency assembly 610 , this method of fluid pump control has the effect of providing control over pump output rate, within the range of the capacity of the pump, and without the need to measure pump output rate directly. In a third embodiment, the electric motor section 300 is first started and then stopped after a desired time interval has elapsed or alternatively after a desired number of motor shaft revolutions has occurred, while both motor torque and motor speed are controlled within desired ranges of values. This method of pump control has the effect of providing control of discrete pump output volumes, at desired output pressures and at desired pump output rates, within the range of the capacity of the pump.
[0048] FIG. 7 a is a schematic cross-sectional view of an embodiment of a planetary roller screw 700 with a hollow central bore. Planetary roller screws with solid central cores are commercially available. A plurality of roller screws with helical splines on the outer surfaces thereof 704 are disposed between a nut 701 and a lead screw 705 comprising a helical spline on the outer surface thereof. Gear teeth are provided on each end of the roller screws to mate with two ring gears 702 while circumferential spacing of the plurality of roller screws is maintained by two spacer inserts 703 .
[0049] FIG. 7 b is a schematic cross-sectional view of an embodiment of a recirculating roller screw 710 with a hollow central bore. Recirculating roller screws with solid central cores are commercially available. A plurality of roller screws with circumferential grooves on the outer surfaces thereof 712 are disposed between a nut 711 and a lead screw 715 comprising a helical spline on the outer surface thereof. Engagement between the roller screw circumferential grooves and the lead screw helical spline is made possible through the use of even multiples of multi-start threading for the helical spline. Circumferential spacing of the plurality of roller screws is maintained by a roller cage 713 which is held in position by two retainers 714 .
[0050] FIG. 7 c is a schematic cross-sectional view of an embodiment of a lead screw 720 with a hollow central bore. Lead screws with solid central cores are commercially available. A nut 721 comprising a helical spline on the inner surface thereof is directly engaged with a lead screw 722 comprising a helical spline on the outer surface thereof.
Operation:
[0051] Referring now to FIG. 1 and to FIG. 2 , in a first embodiment the high efficiency fluid pump intake 501 is brought into fluid communication with a hydraulically isolated area of the geological formation 103 via external fluid port 161 , while the high efficiency fluid pump exhaust 502 is brought into fluid communication with the borehole annulus via external fluid port 141 . This first embodiment permits fluid to be extracted from the formation 103 and expelled into the borehole annulus while pressure measurements are recorded. In a second embodiment the high efficiency fluid pump intake 501 is brought into fluid communication with the borehole annulus via external fluid port 141 , while the high efficiency fluid pump exhaust 502 is brought into fluid communication with a hydraulically isolated area of a geological formation 103 via external fluid port 161 . This second embodiment permits borehole fluid to be injected into the formation 103 while pressure measurements are recorded. In a third embodiment the high efficiency fluid pump intake 501 is brought into fluid communication with a hydraulically isolated area of a geological formation 103 via external fluid port 161 , while the high efficiency fluid pump exhaust 502 is brought into fluid communication with a sample chamber disposed in the optional fluid sampling section 130 . This third embodiment permits fluid to be extracted from the formation 103 and expelled into the sample chamber while pressure measurements are recorded. In a fourth embodiment the high efficiency fluid pump intake 501 is brought into fluid communication with a cushioning fluid contained in a first isolated volume in a fluid sample chamber disposed in the optional fluid sampling section 130 , while the high efficiency fluid pump exhaust 502 is brought into fluid communication with the borehole annulus via external fluid port 141 . This fourth embodiment permits the cushioning fluid to be extracted from the first isolated volume in the fluid sample chamber while formation fluid is simultaneously drawn into a second isolated volume in the sample chamber that is separated from the first isolated volume by means of a moveable piston. This arrangement permits the collection of formation fluid samples without the risk such formation fluid samples becoming contaminated through direct contact with internal pump components. In a fifth embodiment the high efficiency fluid pump intake 501 is brought into fluid communication with a stimulation fluid contained in a chamber disposed within the optional well stimulation fluid carrier section 170 , while the high efficiency fluid pump exhaust 502 is brought into fluid communication with a hydraulically isolated area of a geological formation 103 via external fluid port 161 . This fifth embodiment permits stimulation fluid to be injected into the formation 103 while pressure measurements are recorded. In a sixth embodiment the high efficiency fluid pump intake 501 is brought into fluid communication with the borehole annulus via external fluid port 141 , while the high efficiency fluid pump exhaust 502 is brought into fluid communication with a first isolated fluid chamber disposed within the optional well stimulation fluid carrier section 170 . This sixth embodiment permits borehole fluid to be expelled into the first isolated fluid chamber, while stimulation fluid contained within a second isolated fluid chamber that is separated from the first isolated volume by means of a moveable piston is simultaneously injected into the hydraulically isolated area of a geological formation 103 . This arrangement permits the handling of corrosive stimulation fluids such as acids without such corrosive fluids coming into direct contact with internal pump components.
[0052] In all embodiments, the desired pumping parameters are determined and appropriate reference values or ranges of values for motor torque 602 and for motor speed 603 are calculated and transmitted by telemetry link to the downhole motor controller 601 . The downhole motor controller 601 may use a commercially available method of motor control such as “Field Oriented Control” or “Flux Vector Control” to regulate both motor torque and motor speed independently. After an acknowledgment that the reference values have been received by the motor controller 601 a command is sent to start the motor section 300 . On motor start up, the initial direction for motor rotation is determined by the position of the reciprocating piston assembly 540 in relation to the limits of its travel, and is selected to be the greater of the two available distances. Mechanical power from the output shaft of the motor assembly is transmitted via the spider coupler 330 and the détente ball torque limiter 340 to the lead screw 410 of the hollow helical mechanism 400 . The rotating lead screw 410 induces linear motion in the helical nut assembly 413 and consequently transmits this linear motion to the reciprocating piston shaft 551 which is connected to the helical nut assembly 413 by hollow coupler 416 . This linear movement of the reciprocating piston shaft 551 causes the piston assembly 540 to move within the bore of the pressure tube 550 resulting in the displacement of fluid. This fluid displacement causes an increase in fluid pressure on one side of the moving piston assembly 540 , defeating the exhaust return spring 512 of the exhaust valve 513 located on the higher pressure end of the pump to permit an exhaust of the pressurized fluid. Simultaneously, there is a drop in fluid pressure on the opposite side of the moving piston assembly 540 , defeating the intake return spring 522 of the intake valve 523 located on the lower pressure end of the pump to permit an intake of the unpressurized fluid. As a safety precaution against loss of communications, the motor controller 601 will only continue to operate the motor section 300 for a fixed period of time, unless it receives a further command to continue for another fixed period of time. This scheme has the effect of permitting semi-autonomous downhole motor control with a built in failsafe mechanism. Whenever the piston assembly 540 approaches the end of its permitted travel in either direction, the motor controller 601 applies a proprietary algorithm to decelerate motor speed to zero and then to reverse the direction of motor rotation and accelerate once again to the motor reference speed 603 or to the previous speed setting within the permissible range of values. Whenever the direction of travel of the piston assembly 540 changes, both intake check valves 523 and both exhaust check valves 513 change their state, opening or closing as required. As pumping progresses, pertinent data are transmitted from downhole to a surface display that can be viewed by the operator. Adjustments may be made to the motor torque 602 and motor speed 603 reference values by the operator and the new values may be sent downhole to the motor controller 601 in order to fine tune the characteristics of the pumping. At the conclusion of the pumping operation a stop command is sent to the downhole motor controller 601 .
[0053] In this patent document, the word “comprising” is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements.
[0054] The following claims are to be understood to include what is specifically illustrated and described above, what is conceptually equivalent, and what can be obviously substituted. Those skilled in the art will appreciate that various adaptations and modifications of the described embodiments can be configured without departing from the scope of the claims. The illustrated embodiments have been set forth only as examples and should not be taken as limiting the invention. It is to be understood that, within the scope of the following claims, the invention may be practiced other than as specifically illustrated and described. | A high efficiency fluid pumping apparatus and methods having of an electronic motor controller controlling at least one electric motor that is directly coupled to the input of a hollow helical mechanism. The output of the hollow helical mechanism is directly coupled to the shaft of a reciprocating piston pump. Each moving component of the apparatus is designed with a hollow central bore, so that the apparatus assembly will accept a continuous, stationary, hollow conduit containing electrical through wiring and or fiber optics for power and communication to devices physically positioned below the apparatus. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention related to computer modeling.
2. Scope Of Related Prior Art
Computer models typically are shown visually to a user in which surfaces are displayed at desired locations and orientations. The user may interact with the model to cutaway, move and otherwise manipulate portions of the model. However, much of the this is done without the aid of tactile feedback.
Typically, when a sculptor is modifying or manipulating a physical model, there is force feedback. The computer model simulation lacks this element.
There has been some limited use of force, or haptic, feedback. In molecular docking studies, a robotic arm was used to supply molecular interaction forces as described in "Project GROPE: Haptic Displays for Scientific Visualization," by F. P. Brooks, P. M. Ouh-Young, J. J Batter, P. J. Kilpatrick, Proceedings of SIGGRAPH '90, pp. 177-186 (August 1990).
In another application, a haptic device was used as a nanomanipulator for a scanning tunneling microscope as described in "The Nanomanipulator: A Virtual-Reality Interface for a Scanning Tunneling Microscope" by R. M. Taylor, W. Robinett, V. L. Chi, F. P. Brooks, W. V. Wright, R. S. Williams, and E. J. Snyder, Proceedings of SIGGRAPH '93, pp. 127-134 (August 1993). This enabled scientists to manipulate individual atoms on a planar surface. This, however, was limited only to this specific use.
A medical planning and training system in "Dynamic Force Feedback in a Virtual Knee Palpation," by G. Burdea, N. Langrana, K. Lange, D. Gomez, and S. Deshpande, Journal Of Artificial Intelligence in Medicine, (1994). has also been developed which simulates knee palpation through the use of visual and haptic feedback. This system was specially designed for, and works only with knee palpation.
Currently there is a need to provide tactile feedback corresponding with a visual representation of a computer model to aid in model manipulation.
SUMMARY OF THE INVENTION
A computer model system starts with a volumetric dataset model. A visual representation is provided to an operator. The operator then employs a haptic device to "examine" the model. The haptic device(s) is monitored to determine its location. This location is equated to locations of the model. A scalar map of values, referred to as density values are employed in determining a normal force to an isosurface, and also viscous forces opposite the velocity of the haptic device. This creates the illusion of physically touching the model.
The operator may then select one of several "virtual tools" which can be used to modify the volumetric model. The model parameters in a small locality of the device are modified to create the illusion of melting, building-up, painting, air brushing, burning, stamping and other modifications to the model. The forces provided to the haptic device are also modified to be consistent with the visual representation and the volumetric model.
OBJECTS OF THE INVENTION
An object of the present invention is to provide a system which provides force feedback sensation to an operator consistent with a visual representation of the computer model.
Another object of the present invention is to provide a means for manipulating a three-dimensional volumetric model in which the user may visualize modifications and "feel" the model as it is being modified.
BRIEF DESCRIPTION OF THE DRAWINGS
While the novel features of the invention are set forth with particularity in the appended claims, the invention, both as to organization and content, will be better understood and appreciated, along with other objects and features thereof, from the following detailed description taken in conjunction with the drawings, in which:
FIG. 1 is a simplified flowchart illustrating the functioning of the present invention.
FIG. 2 is a diagram of the forces being simulated.
FIG. 3 illustrates the use of some model modification tools on a volumetric wall.
FIG. 4 is a simplified block diagram of a computer modeling system according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
A simplified flowchart of the functioning of the present invention is shown in FIG. 1. The haptic interaction loop begins in step 11 after an initial image of the scene has been computed and displayed. The next step in the interaction loop is to obtain the current position and orientation of a haptic pointer device operated by an operator 1 at step 13. The virtual counterpart of this physical pointer device will be referred to as a "tool", since it will often be used, for example, as a virtual scalpel, chisel, or paintbrush.
An operator may intend to modify the model in step 15. If necessary, the modification computation is performed in step 17, and the volume database is updated in step 19. In addition, the pixel status buffer is updated in step 21 to indicate which pixels of the image have been affected by this modification operation.
Once the optional modification step is complete, the current force is computed in step 23 and supplied to the haptic device.
During the rendering in step 25, some small number of pixels that require updating are rendered by conventional methods, such as a ray casting method.
Finally, in step 27, it is determined if it is time to refresh the physical display device. If so, the current image is copied to the screen and graphics hardware is used to render a geometric object in step 27 that indicates the size, position, and orientation of the current tool.
The data modification operation need not occur for every iteration of the haptic interaction loop. Instead, a timer may be employed indicating elapsed time since the previous modification. The main reason for limiting the rate at which data modification occurs is that in the preferred embodiment, a haptic refresh rate of 1 to 5 kHz is maintained. Therefore, there is only a small amount of computational time left over after the force calculation in each iteration. Increasing the rate of data modification would decrease the amount of time available to update the pixels of the image affected by the modification.
The rate at which the physical display device is refreshed is also limited by an elapsed time threshold. In the case, the limit is imposed since refresh rates much greater than 30 Hz are unnecessary.
Each voxel of the volumetric data set represents some properties of the data in the small three-dimensional region surrounding that voxel. Typically, volumetric data consists of scalar values representing material density, from which a gradient direction and magnitude can be computed. Shading properties such as color and ambient, diffuse, and specular lighting coefficients may also be stored in each voxel. A voxel may contain additional material properties such as stiffness and viscosity.
Example data which could be used to represent a voxel of the computer model are shown in Table 1. In this example, a single index value is used to represent several material properties through the use of a look-up table. This reduces the amount of computer memory required to store the model, but requires all properties derived from the look-up table to be modified simultaneously.
TABLE 1______________________________________Property Type Size (bytes)______________________________________Density Scalar 1Gradient Direction Encoded Unit Vector 2Gradient Magnitude Scalar 1Color R,G,B 3Material Properties Look-up Table Index 1______________________________________
The force equations are based on two principal requirements. First, the interaction forces must be calculated fast enough to be used within an interactive system. Second, the forces imparted to the user should be consistent with the rendering of the volumetric object.
In order to meet the speed requirement and since the haptic device used in the present implementation could only handle translation forces, the force calculation is simplified to a point contact. This has been shown to be a reasonable simplification for many tasks. The general equation used for feeling an object using a point contact model is:
F=A+R(V)+S(N) (1)
and is illustrated in FIG. 2. The force F supplied to operator 1 located at position P and moving in direction V is equal to the vector sum of an ambient force A, a motion retarding force R(V), and a stiffness force S(N) normal to object D 2 which is inside object D 1 . The ambient force A is the sum of all global forces acting on the tool, such as a gravitational or buoyant force. The motion retarding force is proportional to velocity and can be used to represent a viscous force. The last term captures the stiffness of the object and is always in the direction of the gradient. When simulating interaction on rigid surfaces, which are generally governed by Hooke's law, this term can then be set to a linear force function in the direction of the surface normal and proportional to the penetration distance of point P.
This general equation for force feedback is the basis for calculating forces which are consistent with different types of rendering methods.
The display of volume data may require segmentation of a volume into its parts. In a similar manner, a segmentation step which produces force feedback properties to the model may also be employed.
In Table 1, please notice that the material properties take into account both viscous and stiffness forces.
While it is possible to precompute distance to an isosurface for every voxel in the volume, it was decided to investigate techniques for approximating stiffness and retarding forces based only on the density field. There are two reasons for this. First, the system allows for the interactive modification of the volume. Creating a new distance map for the volume would be prohibitive. Second, for small penetration distances, the density field itself can give a reasonable approximation of the distance to an isosurface. Similar to volume rendering, the retarding and stiffness force functions used to feel an isosurface become dependent on transfer functions: ##EQU1##
Here the density d is used as an indicator of penetration distance between the isosurface density values d i and d j , where d i <d j . The function f r (d) maps density values into retarding force magnitudes while f s (d) maps density value into stiffness force magnitudes. For example, these transfer functions may be: ##EQU2##
The retarding force f r (d) is set to a linear function proportional to the difference in density above d i . Similar to haptic volume rendering, the coefficients E, F, and G specify a linear mapping from density values to force magnitudes.
The stiffness force f s (d) varies from zero to G depending linearly on where the value d lies between d i and d j . This can be viewed as a penetrable shell model with viscous internal properties. A nice property of this model is that it allows the user to feel subsurface structure since the density and normal vector may change below the surface. Many other operator-selected transfer functions may be used.
To aid the user during volume modification, synthetic guide forces can be applied. For example, a virtual plane perpendicular to a surface can be used as a guide when attempting to cut a straight line.
The data modification component of this haptic visualization method is an optional component that can be used to modify any local property of the data stored in the volume database. A local property is one that affects only a small region of the volume, and therefore will cause only a small region of the image to require updating. All properties represented by a value stored in each voxel are local properties of the model. Values which are derived through the use of a look-up table represent dependent properties that cannot be modified independently. For example, if opacity is derived from a look-up table indexed by material density, it cannot be modified using this method since any change to the look-up table could potentially result in wide spread changes in the model. The index value itself could be modified, thereby modifying all properties that are derived from the look-up table. If opacity is instead stored in each voxel, then this is a local property that can be modified with this method.
Local data properties can be modified by setting them to a constant value, or by applying a filter to the current values. With the constant value method, the current color value in each voxel that the tool encounters could be replaced by some constant color value in order to "paint" the object.
With the filter method, an object could be "melted" by updating density values in a small region around the tool location according to d i =(1-α)d i-1 , where d i is the new density value, d i-1 is the current density value, and α is obtained by sampling a spherical filter with a Gaussian distribution centered at the tool location.
In contrast to melting, an object can be "constructed" using, d i =αD+(1-α)d i-1 where D is the density of the material that we are adding to the volume. Note that melting is just a special case of constructing with D=0. In fact, constructing will appear like melting whenever the opacity of d i is less than the opacity of the d i-1 that it is replacing.
The two modification methods described above can lead to a wide variety of tools by varying the constant value or filter type, and the data properties that are modified. In the present system, a modification operation is defined by providing the modification method, the extent of modification, the properties affected, and any necessary filter and constant values. A tool is composed of one or more modification operations, with the condition that no property is affected by more than one modification operation in a tool.
FIG. 3 illustrates the use of some model modification tools on a volumetric wall. These tools are described briefly in Table 2, where the first column indicates a tool name, the second column lists the modification method used for each operation, the third column defines the properties that are modified for each operation, and the last column describes the modification process. Specific constants for the instance of the tools shown in FIG. 2 are given in parenthesis in the last column.
TABLE 2______________________________________ Property DescriptionTool Name Method Affected (example)______________________________________Melt Filter Density remove densityConstruct Filter Density add density (63% dense)Burn Filter Density remove density Filter Color blend in blackSquirt Filter Density add density (63% dense) Filter Color add colorStamp Filter Density add shape (cross- hair filter) Filter Color add color (green) Constant Index set material (shiny)Paint Constant set color (yellow) Constant set material (shiny)Airbrush Filter Color blend color (purple) Constant Index set material (dull)______________________________________
In FIG. 4 a computer modeling system according to the present invention is shown. Operator 1 interacts with a haptic device 33, a control panel 31 and a display device 35. The display device may be any apparatus which can display two-dimensional images and computer models to operator 1. The control panel may be any conventional input device used for providing information to a computer system, or may be the haptic device itself.
The haptic device may be an input/output type device such as a "pencil-like" segment which operator 1 holds, connected to a series of arm segments in which the segments are connected to each other to make a continuous mechanical arm. Each segment meets at a joint which has both a sensor for determining the angular position of the joint, and a motor for causing a feedback force to be applied between the arm segments, and ultimately to the operator. A tip of a "pencil-like" arm segment of a haptic device 33 may be used as the functional point at which forces are computed and modifications are made.
A computer model is created by a model creation device 3 and provided to model memory 43. Optionally, model memory may receive a computer model in its final form and have it prestored. A tracking device 37 (which may alternatively be provided by haptic device 33) monitors sensors of haptic device 33 to determine a location of a desired point of haptic device 33. Typically the point monitored would be the end of the "pencil-like" arm segments of haptic device 33.
A force computation device 39 is connected to tracking device 37 and model memory 43. Force computation device 39 receives the information from tracking device 37 to determine the location of the functional point of the haptic device. When this point has a location which intersects the model stored in model memory 43, force computation device provides a force value to haptic device 33 causing haptic device 33 to exert that amount of force in the specified direction against operator 1. This gives the illusion to operator 1 that the tip is hitting the model.
Model memory has stored densities which represent stiffness and viscosity coefficients for different locations of the model to simulate different materials. For example, a very high stiffness force and a low viscosity force would simulate ice and conversely a very low stiffness force and a high viscosity would simulate a putty- like object.
A renderer 45 reads the graphics information from model memory 43 and provides this information to a display device 35. Display device 35 then displays model surfaces, and optionally the haptic device in correct relation to those model surfaces which is correctly associated with the forces experienced by operator 1 from haptic device 33. This provides the illusion through both sight and touch of actually interacting with the virtual model.
Not only is it possible to interact with, feel, and visualize the model, but when operator 1 interacts with control panel 31, a mode may be selected in which the model may be modified and forces computed and images rendered according to the modified model. The modes determined by a control panel 31 may allow operator 1, using haptic device 33 to cut away, burn, melt, build up, pull, or push portions of the model in the vicinity of the tip of pencil-like arm of haptic device 33.
Based on the mode selected by operator 1 through control panel 31, a model modification device 41 modifies parameters of the model consistent with the mode and location of haptic device 33. Examples of possible modifications which may be made to the model are described later.
The present invention provides force feedback based upon the characteristics of the model itself, however, the present invention does not have to be limited to only non-moving objects. The present invention, with proper force calculations, may also provide force feedback for interaction with moving objects. For instance, haptic device 33 may be used to collide with, or "hit" an object causing the object to move to a different location. This may provide feedback such as a "feel" of hitting an object which may be possibly moving when it is hit. The material of the object may also be taken into account along with the motion and momentum of the object in order to have the object crush or deform as it is hit and/or moved in a direction. In the instance of a collision, an inertial force is also computed and added to the other existing forces to produce the resultant force.
The more processing and the more complex the calculations, the more processing power is required which may become restrictive. Theoretically, however, it is possible to determine, and provide this force and visual feedback of moving bodies.
While specific embodiments of the invention have been illustrated and described herein, it is realized that modifications and changes will occur to those skilled in the art. It is therefore to be understood that the appended claims are intended to cover all such modification and changes as fall within the true spirit and scope of the invention. | A computer modeling and visualization system employs both 3D visual modeling and force feedback through a haptic device consistent with the visual display of the computer model. Force, or haptic, interaction is employed for exploring computer models. Point contact force equations were created for quickly computing forces directly from a model data which are provided to the haptic device, causing it to apply that force to an operator. The force equations employed are consistent with isosurface and volume rendering, providing a strong correspondence between visual and haptic rendering. The method not only offers the ability to see and feel the volumetric model but allows interactive modification and display of the model. | 6 |
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable
CROSS-REFERENCE TO RELATED APPLICATIONS
Priority of U.S. Provisional patent application Ser. No. 60/025,371, filed Sep. 3, 1996, for "Ball Pump Including Spare Needles and Storage for Spare Needles" and of U.S. Provisional patent application Ser. No. 60/032,880, filed Dec. 13, 1996, for "Apparatus for Picking up, Transporting, and Storing Balls", both incorporated herein by reference, is hereby claimed.
REFERENCE TO A "MICROFICHE APPENDIX"
Not applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to apparatus for use with sports balls. More particularly, the present invention relates to sports ball retrieving, transporting, and storing apparatus.
2. General Background of the Invention
The most common means of transporting and storing larger sports balls is in a bag made of mesh netting whose opening and closing is controlled by a draw string. Loosening the draw string permits the bag to be opened sufficiently to allow the balls to be placed in the bag. The draw string is then drawn or pulled to sufficiently reduce the bag opening and then fastened to prevent the balls from falling or rolling out of the net bag. Another common means of transporting and storing balls is a bag made of canvas, mesh or various synthetic fabrics (i.e. nylon) or a combination of these materials whose opening is controlled by the use of fasteners (including but not limited to zipper(s), Velcro brand fastening strips, snaps, hooks, buttons, rope, bungee cords or other devices or means). The fastener is unfastened and the balls are placed in the bag. The fastener is then refastened which helps prevent the balls from falling or rolling out of the bag.
The above-mentioned netting and bag represent the state of the art for larger balls (i.e. soccer, volleyball, basketball, football, rugby, general recreational balls used in grade schools, etc.) and are only capable of transporting and storing balls not picking up the balls. The bags and nets when used for storage present additional problems. It is difficult, and at time impossible, to do an accurate visual inventory of the balls because of the opacity of the fabric or the inability to clearly see all the balls in a net because some balls will partially or totally block the view of the other balls. Since a quick, accurate, visual inventory cannot be done with bags or nets, balls will be lost. The loss of balls is a costly event because of the constant need of buying unnecessary replacements.
Storing balls in bags is undesirable because many types of balls need to dry out thoroughly and bags do not permit air to circulate easily around the ball which increases the likelihood of mold and mildew which reduces the life of the ball. Nets and bags are awkward to hang for storage and normally end up of the floor. For example, in youth soccer leagues, each team has a ball bag and at the end of the season there may be fifty or more bags left on the floor as storage. This is not only a very poor way to store balls but it is a time consuming nightmare for the equipment managers who do the yearly inventory for leagues with many teams.
The nets and bags are not capable of picking up the balls, awkward to open, difficult to load (really a two person operation) and virtually impossible to get a quick accurate visual inventory which increases the chance of losing balls. One professional soccer team mentioned that they lose two soccer balls per practice. Recreational youth leagues give out fewer and fewer balls to the volunteer coaches because so many balls are lost or not returned at the end of the season. It is estimated that leagues replace between 15-25% of their ball inventory every season simply due to loss.
It can clearly be seen that there exists a need for an apparatus for picking up, transporting and storing balls for convenience, practicality and monies saved by having to purchase fewer replacement balls.
The following references are incorporated herein by reference (as are all references cited by these references): (related to the ball retriever):
U.S. Pat. Nos. 4,184,707; 4,193,625; 4,334,601; 4,596,413; 5,083,797; 5,086,948; 5,238,162; 5,292,161; 5,433,491; 5,634,680; EP 289 428 A; (related to the ball pump):
U.S. Pat. Nos. 438,150; 463,507; Des. 88,081; 2,960,263; 3,014,595; 3,412,897; 4,278,119; 4,716,796; 4,797,040; 5,427,003.
BRIEF SUMMARY OF THE INVENTION
The present invention comprises two independent, rigid or semi rigid, rectangular frames held parallel by equal (or approximately equal) lengths of tension elements (elastic cords) at /or near (within 12 inches) of each corner of the frame. If the frame is lengthened or widened (two or more ball apparatus frames are aligned and attached together either permanently or temporarily) additional tension elements may be placed along the frame to insure that sufficient tension is maintained to hold (pinch) the balls between the framing members.
The force necessary to stretch the tension elements is important. It is essential that the tension element provide sufficient tension to hold the balls in the frame yet be capable of being stretched to allow the ball to enter the frame with moderate effort. The size, type and number of balls to be picked up and transported determines the relative tension range necessary (i.e. the collective tension necessary to pick up and store 12 ping pong balls is very little, less than 5 ounces, whereas the collective tension necessary in a single ball apparatus to pick up and store four size 4 soccer balls is between 10 to 24 lbs. of tension (force)).
The width of the frame is determined by the diameter of the ball (volume) to be picked, transported or stored. The interior width of the framing members must be narrow enough to prevent the ball (volume) from falling through or getting stuck in the frame yet wide enough to create a channel to help hold the balls securely in the apparatus. If one were to inscribe a square in a circle, where the four comers just touch the circle, the width of the square is equal to approximately 70% of the diameter of the circle. Therefore, the corners of the inscribed square are the optimum stable points to apply pressure. The optimum design is to have the framing members pinch the balls at the stable points and then provide adequate channel width to help insure that the balls stay in the apparatus. The range for an open framing member (channels to the hold balls) is 50-90% of the ball diameter.
The present invention comprises a ball retrieving apparatus for retrieving balls of a first diameter, comprising a pair of parallel, spaced-apart frames and tensioning means connecting the two frames, urging the frames together, the tensioning means applying sufficient tension on the frames to normally keep them apart a distance less than the first diameter, but the tensioning means being sufficiently elastic to allow the frames to separate enough to allow a ball to pass between the lower portion of the frames. Preferably, the tensioning means also comprise spacing means for urging the frames apart.
The present invention can also be described as apparatus for picking up, transporting and storing balls, comprising:
two opposing frames;
tension elements separating the two opposing frames;
wherein, when the two opposing frames are forced over a sphere, the tension elements stretch and/or the sphere compresses sufficiently to permit the sphere to enter between the frames, and once the sphere is between the frames it is kept in place by the forces created by the stretched tension elements trying to regain their original unstretched configuration and the pinched sphere trying to regain its original configuration by trying to expand out. The tensioning means preferably also comprise spacing means for urging the frames apart. The frames can advantageously have a width less than the diameter of a ball to be retrieved therewith, and the frames are preferably spaced apart less than the diameter of a ball to be retrieved therewith. In some cases, the frames have a width less than twice the diameter of a ball to be retrieved therewith. Preferably, the frames have a length aprroximately equal to four to five times the diameter of a ball to be retrieved therewith.
The ball retrieval apparatus of the present invention can be used for balls for soccer, volleyball, basketball, football, rugby, general recreational balls used in grade schools, baseballs, tennis balls, ping pong balls, and golf balls, for example (in general, when used for smaller balls, the number of balls held per retriever increases).
The present invention also includes ball pump apparatus comprising a ball pump which uses detachable needles for inflating balls and at least one storage receptacle for the detachable needles. Preferably, the ball pump includes a handle having an outer diameter and a barrel having an outer diameter, there is a storage receptacle in the handle, and the outer diameter of the handle is approximately equal to the outer diameter of the barrel. The storage receptacle could instead or in addition be in the barrel. The handle is preferably at least partially transparent. Preferably, a plurality of needles are included in the receptacle. Preferably, the needles are positionable in the receptacle to make noise when the ball pump is shaken; for example, the needles can be stored loose in the storage receptacle in the handle.
BRIEF DESCRIPTION OF THE DRAWINGS
For a further understanding of the nature, objects and advantages of the present invention, references should be had to the following detailed description taken in conjunction with the accompanying drawings, in which like reference numerals denote like elements, and wherein:
FIGS. 1-33 show the ball retrievers of the present invention; and
FIGS. 34-47 show the ball pumps of the present invention
DETAILED DESCRIPTION OF THE INVENTION
Ball Retrieving apparatus
FIGS. 1 and 2 show a first embodiment of the ball retrieving, storing, and transporting apparatus of the present invention, ball retriever 10. Ball retriever 10 includes two frames 11, 12 made of preferably tubular material, such as aluminum or plastic pipe (such as polyvinylchloride--PVC). Bungee cords 13 (or other suitable tensioning means or tension elements) connect frame 11 to frame 12, passing through holes drilled or otherwise formed in frames 11 and 12. Caps 14 could be threaded and include a slot for a screwdriver (or could simply be plugs which friction fit into the outside holes) to close the outer holes through which bungee cords 13 pass (the outer holes are bigger than the inner holes to allow a knot or crimp or other bungee cord retaining means to pass into frames 11 and 12). A strap 20 includes a first portion 21 and a second portion 22 connected with a buckle 23 to allow strap 20 to come apart for loading of cones 50, 55 (as shown in FIGS. 6 and 7). Strap 20 is held onto the frame 12 with sewn loops 24. Retriever 10 can preferably hold 4 balls (such as size 4 or size 5 soccer balls, volley balls, footballs, basketballs, etc.).
One could omit the sewn loops 24 and buckle 23 from strap 20 and instead use attaching devices such as Velcro brand hook-and-loop fasteners or snaps on each end of the strap 20 to hold strap 20 onto frame 12 and allow the strap 20 to receive cones 50, 55. End attachments are ultimately more convenient to use but increase production costs.
FIGS. 3, 4, and 5 show soccer balls in apparatus 10. In FIGS. 3 and 4, there are four size 4 balls 34. In FIG. 5, there are two size 4 balls 34, one size 5 ball 35, and one size 3 ball 33.
FIGS. 6 and 7 show an alternative ball retriever 110 which includes telescoping frames 111 and 112 (to allow the number of size 4 balls to be carried to vary from 3 to 5, for example). Any suitable telescoping means can be used to accomplish this. Also, frames 111 and 112 include textured handles 141 to allow easy grasping of the retriever 110. Retriever 110 also includes a bag 40 (zippered, for example) for holding a first aid kit, for example.
FIGS. 8 and 13 show the preferred embodiment of the present invention, retriever 210. Retriever 210 includes first, second, third, fourth, fifth, sixth, seventh and eighth 13/4" by 13/4" PVC elbow connectors 231 for connecting 3/4" PVC pipe, each elbow connector having a 1/4" diameter hole drilled therein. Retriever 210 also includes a first 1/4" diameter, 51/2" long, bungee cord 13 connecting the first and fifth elbow connectors, a second 1/4" diameter, 51/2" long, bungee cord 13 connecting the second and sixth elbow connectors, a third 1/4" diameter, 51/2" long, bungee cord 13 connecting the third and seventh elbow connectors, a fourth 1/4" diameter, 51/2" long, bungee cord 13 connecting the fourth and eighth elbow connectors. A first 4" long PVC pipe 232 is connected to the first and second elbow connectors with internal pipe connectors, a second 4" long PVC pipe 232 is connected to the third and fourth elbow connectors with internal pipe connectors, a third 4" long PVC pipe 232 is connected to the fifth and sixth elbow connectors with internal pipe connectors, and a fourth 4" long PVC pipe 232 is connected to the seventh and eighth elbow connectors with internal pipe connectors. A first 321/2" long PVC pipe 233 is connected to the first and third elbow connectors with internal pipe connectors, a second 321/2" long PVC pipe 233 is connected to the second and fourth elbow connectors with internal pipe connectors, a third 321/2" long PVC pipe 233 is connected to the fifth and seventh elbow connectors with internal pipe connectors, and a fourth 321/2" long PVC pipe 233 is connected to the sixth and eighth elbow connectors with internal pipe connectors. Strap 20 having a first 2' long part 21 and a second 2' long part 22 is connected to the first and second 4" long PVC pipes, the strap 20 having a disconnectible connector 23 to allow the first part of the strap to be separated from the second part of the strap. A bag 40 is riveted to the third and fourth 321/2" long PVC pipes 233; bag 40 may have a zippered opening (with two zippers, for example).
FIG. 9 shows retriever 310, which could, for example, comprise retriever 10 connected to retriever 210 as, for example, with glued connectors.
FIG. 10 shows a retriever 410 long enough to hold 5 size 4 soccer balls. Instead of bungee cords 13, retriever 410 uses elastic fabric panels 413, made of for example Spandex brand elastic fabric, as the tensioning means. Panels 413 include suitable means to hold them onto frames 411, 412 (such as sewn loops). The frames 411 and 412 can be made of the materials of any of the other frames.
FIG. 12 shows a double retriever 510 including two straps 20, with wide frames 511 and 512.
FIGS. 15-21, 24, and 25 show retrievers of the present invention including netted frames to allow the retrievers to hold more than one vertical line of balls. Retriever 610 is shown in FIG. 15 and includes netted frames 611 and 612. The net material 614 can be attached to frames 611 and 612 in any suitable manner. Retriever 620 is shown in FIGS. 16 and 18 and is slightly narrower than three size 4 soccer balls, while retriever 630 shown in FIGS. 17 and 19 is slightly wider than three size 4 soccer balls. Retriever 640 is shown in FIG. 20 and is slightly narrower than four size 4 soccer balls, while retriever 650 shown in FIG. 21 is slightly wider than four size 4 soccer balls. Retriever 660, shown in FIGS. 24 and 25, includes a wide bag 640. An advantage of the netted retrievers is that they weigh less per ball capacity than the non-netted retrievers shown in FIGS. 1-14 (when the frames are made of the same material).
FIGS. 26 and 28 show a retriever 710 which includes a single piece 713 of bungee cord at the top and a single piece 713 at the bottom which provide elastic members to hold a number of flag poles 60. Suitable means can be provided to prevent lack of flag poles 60 in the retriever 710 from affecting the tension between frames 711 and 712. Flag poles 60 are preferably telescoping, as shown in FIG. 29, from about three or three and a half feet in length to a regulation height for soccer games. Highly visible flags 61 could be made of any high-visibility material and could be replaced with standard orange plastic flags. Flag poles 60 could be made of white PVC pipe, for example. Flag poles 60 have suitable means, such as spikes 62, for holding poles 60 in the ground.
It may be desirable, when plastic pipe is used to make the frames (such as frames 11, 12, 112, 113, 211, 212, 611, 612) to put vent holes somewhere in the frame to allow heat to escape from the pipe to perhaps prevent the pipe from warping when left in a hot car.
As can be seen in the drawings, it is preferred to have only one vertical layer of balls in the ball retrieving apparatus of the present invention to allow the balls to be easily counted.
FIGS. 30-33 show a bag 150, which is similar to a standard, commercially available net bag for soccer balls, but which has an easy means for opening and closing the bag. The net portion 151 of bag 150 could be made of nylon, for example. Bag 150 includes a net portion 151 and a closure portion 152. The closure portion 152 can include a plastic loop 153 and some means for closing the portion of the loop 153 adjacent the opening of the bag 150. The loop 153 can be slidably threaded onto the net portion 151 of the bag, and a closure slide 154 can be somehow fixedly attached to a portion of the net portion 151 of the bag 150 so that sliding the closure slide 154 toward the bag opening causes the opening to close, and sliding the closure slide in the other direction causes the opening to open. Loop 153 is sufficiently stiff to cause the net portion of the bag to open when the slide is moved away from the opening.
Loop 153 can be made of a thin flexible plastic hollow tube material (or it could be solid) so that when it opens, it flexes the net open and allows balls to be easily pushed in with one's feet, as shown in FIG. 32. A strap portion 155 is preferably made of some comfortable material to allow the bag 150 to be easily comfortably carried on one's shoulders.
The net portion 151 of bag 150 could be made of nylon, for example.
The loop 153 can, at its end distal from the opening of the bag, removably connect to the net so that cones 50, for example, can be carried on the loop 153. Sports pump apparatus:
The sports pump of the present invention could be attached in some suitable manner to the ball retrieving apparatus of the present invention.
FIGS. 34-47 show sports pumps of the present invention with capability of holding spare needles (and preferably including spare needles therein).
The pump of the present invention can comprise a standard ball pump modified as described herein. In the preferred sport pump 70 of the present invention (see FIGS. 34 and 35), the handle 71 has a diameter approximately equal to the diameter of the barrel 72 or compression cylinder 72 of the sport pump, and has a length great enough to allow spare needles 81 to easily be placed therein. Preferably, the needles 81 can be loose in the handle 71 (as shown in FIG. 34) so that they will rattle around to give an audio signal to the pump owner that there are still spare needles available. The top 73 of the handle is preferably removable (it can be hinged, threaded, friction fit, or magnetic fit). The hollow handle 71 is preferably clear to allow a visual indication of the presence of spare needles 81 (though it could be opaque).
The base of the cap may be optionally threaded to screw onto the compression cylinder (it may also be latched or friction fit).
The lower end of the compression cylinder has a threaded inset for the needle to screw in to.
FIGS. 36A-36F show alternative designs for the hollow handle (handles 71A, 71B, 71C, with removable, for example screw-on, caps 73A, 73B, 73C).
The hollow handle may instead by T-shaped (as handle 76 shown in FIG. 37). Spare needles 81 can be stored as indicated in FIG. 37, and the ends of the storage spaces 77 can be plugged with magnets or any other means for preventing the needles 81 from falling out and being lost.
A disk-shaped handle 78 could hold spare needles 81 in place with magnetic attraction, or there could be a removable cap holding the needles in the plunger (as shown in FIG. 38).
As shown in FIGS. 39 and 40, the spare needles 81 could be placed in the top of the compression cylinder 72 (in which case an optional cover 82 could be used to prevent loss of needles and to keep dirt off of the needle threads).
As shown in FIG. 41, the spare needles 81 could be placed in the top and/or the bottom of the compression cylinder 72 (in which case optional covers 83, 84 could be used to prevent loss of needles 81 and to keep dirt off of the needle threads), placed perpendicular or approximately perpendicular to the compression cylinder 72.
As shown in FIG. 42, the spare needles 81 could be stored in a sleeve 85 attached to the compression cylinder. The sleeve could be extruded or glued or otherwise attached. The sleeve 85 is preferably clear to allow visual inspection of the number of spare needles available. At least one end of the sleeve 85 could have a hinged top, a threaded top, a compression fit, a plug, or some other appropriate cap to keep the needles from falling out of the sleeve.
As shown in FIGS. 44 and 45, the spare needles 81 could be stored in a large diameter plunger rod 92 with a hollow center. The handle 94 of the pump could have a cap 93 thereon to close the hollow rod 92. The cap 93 could be hinged, threaded, compression fit, or a plug.
As shown in FIG. 46, the compression cylinder could have a hard, thick wall. Spare needles 81 could be stored in a cavity 95 in the wall of compression cylinder 172. There could be a sliding cap 96 to cover the cavity to keep the needles in. Instead of a sliding cap, any suitable closure or retaining means could be used, such as plugs or magnets.
As shown in FIG. 47, the compression cylinder could have a soft, thick wall. Compression cylinder 272 could be totally or partially covered with very soft plastic, cork, or Silly Putty-like material so that needles 81 could be pushed directly into the material.
An alternative pump apparatus, not shown in the drawings, would comprise a standard pump in a container (as a clear container for three tennis balls), with extra needles in the container as well.
Bungee cords are the preferred tensioning means because they serve not only to pull the two frames together, but they also keep the frames apart, making it easier to pick up the first ball with the ball pickup apparatus of the present invention.
As can be seen, the ball retrieving apparatus of the present invention serves to retrieve, store, transport, and inventory sports balls easily and efficiently.
All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. All materials used or intended to be used in a human being are biocompatible, unless indicated otherwise.
Fabric-coated elastic cord, such as Bungee cord, can be purchased from Sea Ties in Baton Rouge, La., USA. This cord can be used for the tension means 13, etc.
The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims. | Apparatus for picking up, transporting and storing balls comprises two oposing planes separated by tension elementss which when forced over a solid, hollow or pressurized sphere simultaneously stretches the tension elements and/or compresses the sphere sufficiently to permit the sphere entry between the planes. Once the sphere is between the planes it is kept in place by the forces created by the stretched tension trying to regain their original unstretched configuration and the pinched sphere trying to regain its original configuration by trying to expand out. | 8 |
BACKGROUND OF THE INVENTION
Platelet-activating factor (PAF) has recently been identified as an acetyl glyceryl ether phosphorylcholine (AGEPC), i.e., 1-O-hexadecyl/octadecyl-2-O-acetyl-sn-glycero-3-phosphorylcholine (Hanahan, D. S. et al., J. Biol. Chem., 255: 5514, 1980). It is a potent lipid mediator of inflammation and anaphylaxis and is produced by stimulated basophils, neutrophils, platelets, macrophages, endothelial cells, and IgE-sensitized bone marrow mast cells. PAF exerts a myriad of biological actions. It induces smooth-muscle contraction, aggregration, chemotaxis, and degranulation of neutrophil and heightened metabolic activity of macrophages in vitro. It also reduces coronary blood flow and contractile force of isolated guinea pig heart, leading to cardiac anaphylaxis. In various animal models, PAF induces bronchoconstriction, hyperalgesia, hypotension, neutropenia, thrombocytopenia, increased cutaneous vascular permeability, increased hematocrit, and lysosomal enzyme secretion. In man, intradermal injection of PAF at 0.1 μg per site elicits a biphasic inflammatory response, which is potentiated by prostaglandin E 2 . Thus, PAF has been linked to various biologic activities and pathways making it one of the important mediators responsible for a variety of physiological process which are known to be associated with a large group of diseases, for example, inflammatory diseases, cardiovascular disorders, asthma, lung edema, endotoxin shock syndrome, and adult respiratory distress syndrome.
The compounds of the present invention are potent and specific PAF-antagonists. They belong to the class of neolignan compounds related to piperenone, a known insect antifeeding substance, and 5-allyl-2-(3,4-dimethoxyphenyl)-3a,α-methoxy-3-methyl-2,3,3a,6-tetrahydro-6-oxobenzofuran, the subject matter of copending application Ser. No. 541,806, filed Oct. 13, 1983 now U.S. Pat. No. 4,540,709. Both piperenone and the 5-allyl compound mentioned above were isolated from the Chinese herbal plant Piper futokadzsura Sieb. See K. Matsui et al., Agr. Biol. Chem. 40, 1045 (1976); ibid, 40, 1113 (1976); and Matsui et al., Tetrahedron Letters 24, 1905 (1975). Although the plant has been used in Chinese herbal medicine for the treatment of arthritic conditions, no one had successfully isolated nor identified the active substance until our work on the 5-allyl compound and the compounds of the present invention. We found these compounds to be potent and specific PAF-antagonists useful not only in the treatment of arthritic conditions but also for other diseases including asthma, hypertension, lung-edema, endotoxin shock syndrome, adult distress syndrome and the like.
Accordingly, it is the object of the present invention to provide a class of novel compounds as specific PAF-antagonists.
Another object of this invention is to provide processes for the preparation of these PAF-antagonists.
A further object of this invention is to provide a pharmaceutically acceptable composition containing these novel compounds as the active ingredient for the treatment of diseases which are subject to the mediation of PAF.
Still a further object of this invention is to provide a method of treatment comprising the administration of a therapeutically sufficient amount of one or more of the PAF-antagonists to a patient suffering from various skeletal-muscular disorders including but not limited to inflammation, e.g., osteoarthritis, rheumatoid arthritis and gout; allergic disorders; hypertension; cardiovascular disorder; asthma; lung edema; skin diseases; psoriasis; endotoxin shock syndrome; or adult respiratory distress syndrome.
DETAILED DESCRIPTION OF THE INVENTION
A. Scope of the Invention
This invention relates to the specific PAF-antagonists of formula: ##STR1## wherein R 1 is
(1) when it is joined to the ring by a double bond, O, S, CR 5 R 6 , NR 5 or NOR 5 where R 5 and R 6 independently represent H, loweralkyl, haloloweralkyl, loweralkenyl, aryl or aralkyl as defined below; or
(2) when it is joined to the ring by a single bond, SR 5 , SOR 5 , SO 2 R 5 , NR 5 R 6 , or OR 7 wherein R 7 represents R 5 , COR 5 , COOR 5 , CSR 5 or COSR 5 ;
R 2 is
(a) loweralkyl especially C 1-6 alkyl such as methyl, n-propyl, i-propyl, t-butyl, cyclopropyl, n-hexyl, cyclopentyl or cyclohexyl;
(b) loweralkenyl especially C 1-6 alkenyl such as vinyl, allyl, --CH 2 CH═CH--CH 3 or --CH 2 --CH 2 CH═CHCH 2 CH 3 ; or
(c) loweralkoxy especially C 1-6 alkoxy such as methoxy, ethoxy or propoxy;
(d) lower alkynyl especially C 1-6 alkynyl, e.g. --CH 2 --C.tbd.CH, --C.tbd.C--CH 3 and --CH 2 --C.tbd.C--CH 3 ;
(e) aralkyl especially aryl loweralkyl such as benzyl or substituted benzyl, e.g., p-methoxybenzyl, m,p-dinitrobenzyl o,p-difluorobenzyl or p-methylbenzyl;
(f) haloloweralkyl especially CF 3 ;
R 3 is
(a) loweralkyl especially C 1-6 alkyl;
(b) aryl especially phenyl or substituted phenyl such as p-methoxyphenyl, 2,4-dichlorophenyl, p-methylphenyl or the like; or
(c) loweralkenyl especially C 1-6 alkenyl;
(d) OR 5 where R 5 is as previously defined except that it cannot be CH 3 ;
(e) O--CO--R 5 ;
(f) SR 5 ;
(g) NR 5 R 6 ; or
(h) haloloweralkyl;
R 4 is
(a) loweralkyl especially C 1-6 alkyl;
(b) lower alkenyl;
(c) lower alkynyl;
(d) hydrogen; or
(e) aralkyl;
(f) hydroxy;
(g) alkoxy;
(h) halogen;
(i) azido;
(j) amino;
(k) alkylamino;
(l) dialkylamino;
(m) nitro;
(n) cyano; or
(o) thioalkyl;
X is
(1) H;
(2) loweralkyl especially C 1-6 alkyl such as methyl, ethyl, propyl, t-butyl, pentyl, benzyl, cyclopropyl, cyclopentyl or cyclohexyl;
(3) loweralkenyl especially C 2-6 alkenyl, for example, vinyl, allyl, and buten-2-yl;
(4) loweralkynyl especially C 2-6 alkynyl such as --C.tbd.CH, --CH 2 C.tbd.CH, --C.tbd.C--CH 3 ;
(5) aryl of 6 to 10 carbons especially phenyl or substituted phenyl of formula Ar(X') n wherein X' independently is X, n is 1 to 5;
(6) aralkyl especially aryl loweralkyl such as benzyl or Ar(X') n -loweralkyl;
(7) R 5 O--;
(8) R 5 CO;
(9) R 5 COO;
(10) R 5 COS;
(11) R 5 OCO;
(12) R 5 SCO;
(13) R 5 CONR 6 ;
(14) R 5 NR 6 CO;
(15) R 5 R 6 N;
(16) R 5 S;
(17) R 5 SO;
(18) R 5 SO 2 ;
(19) halo especially fluoro, chloro or bromo;
(20) --O(CH 2 ) m O-- where m represents 1 or 2;
(21) --(NH 2 )C═NH;
(22) --CN;
(23) --NO 2 ;
(24) --(CH 2 ) m OR 5 ;
(25) --(CH 2 ) m COOR 5 ;
(26) heteroaryl or substituted heteroaryl of formula Q r X' where Q r is heteroaryl such as thienyl, furyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl, isoxazolyl, isothiazolyl pyrryl, imidazolyl, pyrazolyl, pyranyl, 2H-pyrryl, imidazolidinyl, imidazolinyl, pyrazolidinyl, pyrrolidinyl, pyrrolinyl, piperidyl, piperazinyl, morpholinyl, tetrazolyl, indolyl or the like; and X' is as previously defined; or
(27) halo loweralkyl especially CF 3 --;
R 8 is
H n-propyl or allyl;
Z is
O, S, SO, SO 2 , NH, NR 6 wherein R 6 is loweralkyl.
Preferably, the compounds of the present invention are of formula (II). ##STR2## wherein R 2 , R 5 , R 4 , X and n are as previously defined.
More preferably the compounds of the present invention are of formula (III) ##STR3## wherein R 2 , R 5 and X are as previously defined.
The most preferred compounds of this invention are those having the following formula: ##STR4##
B. Preparation of the compounds within the scope of the invention
The novel compounds of the present invention can be prepared by the following representative processes: ##STR5## wherein R 8 is H or allyl; and the oxidants can be Pb(OAc) 4 , Pb(OBz) 4 , or Tl(NO 3 ) 3 .3H 2 O etc. ##STR6##
The starting materials of these processes are readily available. For example, the substituted m-hydroxyphenol is commercially available and the cinnamyl alcohol is easily prepared by reduction of the corresponding cinnamic acid.
The condensation to form the phenol ether (IIIa) or (IIIb) is conducted under dehydration conditions, e.g., the Mitsunobu conditions (Synthesis, 1, pabe 1 et seq., 1981), and dehydrobromination, respectively. The ring closure to produce the dihydrobenzofuran intermediate (IVa) or the benzofuran derivative (IVb) is carried out normally in a high boiling aprotic, neutral or basic solvent, e.g., diethylaniline, at about 150°-270° C., preferably, at about 220° to 250° C. When R 8 is allyl, the ring closure proceeds by way of a normal and an abnormal claisen rearrangement similar to that described by Schmid et al. in Helv. Chem. Acta., 55, page 1625 et seq., 1972. Finally, oxidation by lead tetraacetate or other mild oxidation reagents is employed to afford the compound of formula (I). For those compounds that may exist in optical isomers (d-, l-, or dl-form), resolution is accomplished by HPLC (high pressure liquid chromatography) using a chiral pak column or other conventional methods.
C. Utility of the compounds within the scope of the invention
This invention also relates to a method of treatment for patients (or mammalian animals rasied in the diary, meat, or fur industries or as pets) suffering from disorders or diseases which can be attributed to PAF as previously described, and more specifically, a method of treatment involving the administration of a compound of formula (I) as the active constituent.
Accordingly, the compounds of formula (I) can be used among other things to reduce inflammation, to correct respiratory, cardiovascular, and intravascular alterations or disorders, and to regulate the activation or coagulation of platelets, the pathogenesis of immune complex deposition and smooth muscle contractions.
For the treatment of inflammation, cardiovascular disorder, asthma, or other diseases mediated by the PAF, a compound of formula (I) may be administered orally, topically, parenterally, by inhalation spray or rectally in dosage unit formulations containing conventional non-toxic pharmaceutically acceptable carriers, adjuvants and vehicles. The term parenteral as used herein includes subcutaneous injections, intravenous, intramuscular, intrasternal injection or infusion techniques. In addition to the treatment of warm-blooded animals such as horses, cattle, sheep, dogs, cats, etc., the compounds of the invention are effective in the treatment of humans.
The pharmaceutical compositions containing the active ingredient may be in a form suitable for oral use, for example, as tablets, troches, lozenges, aqueous or oily suspensions, dispersible powders or granules, emulsions, hard or soft capsules, or syrups or elixirs. Compositions intended for oral use may be prepared according to any method known to the art for the manufacture of pharmaceutical compositions and such compositions may contain one or more agents selected from the group consisting of sweetening agents, flavoring agents, coloring agents and preserving agents in order to provide pharmaceutically elegant and palatable preparation. Tablets contain the active ingredient in admixture with non-toxic pharmaceutically acceptable excipients which are suitable for the manufacture of tablets. These excipients may be for example, inert diluents, such as calcium carbonate, sodium carbonate, lactose, calcium phosphate or sodium phosphate; granulating and disintegrating agents, for example, corn starch, or alginic acid; binding agents, for example starch, gelatin or acacia, and lubricating agents, for example magnesium stearate, stearic acid or talc. The tablets may be uncoated or they may be coated by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monostearate or glyceryl distearate may be employed. They may also be coated by the techniques described in the U.S. Pat. Nos. 4,256,108; 4,160,452; and 4,265,874 to form osmotic therapeutic tablets for controlled release.
Formulations for oral use may also be presented as hard gelatin capsules wherein the active ingredient is mixed with an inert solid diluent, for example, calcium carbonate, calcium phosphate or koalin, or as soft gelatin capsules wherein the active ingredient is mixed with water or an oil medium, for example peanut oil, liquid paraffin, or olive oil.
Aqueous suspensions contain the active materials in admixture with excipients suitable for the manufacture of aqueous suspensions. Such excipients are suspending agents, for example sodium carboxymethylcellulose, methylcellulose, hydroxypropylmethylcellulose, sodium alginate, polyvinylpyrrolidone, gum tragacanth and gum acacia; dispersing or wetting agents may be a naturally-occurring phosphatide, for example lecithin, or condensation products of an alkylene oxide with fatty acids, for example polyoxyethylene stearate, or condensation products of ethylene oxide with long chain aliphatic alcohols, for example heptadecaethyleneoxycetanol, or condensation products of ethylene oxide with partial esters derived from fatty acids and a hexitol such as polyoxyethylene sorbitol monooleate, or condensation products of ethylene oxide with partial esters derived from fatty acids and hexitol anhydrides, for example polyxyethylene sorbitan monooleate. The aqueous suspensions may also contain one or more preservatives, for example ethyl, or n-propyl, p-hydroxybenzoate, one or more coloring agents, one or more flavoring agents, and one or more sweetening agents, such as sucrose or saccharin.
Oily suspension may be formulated by suspending the active ingredient in a vegetable oil, for example arachis oil, olive oil, sesame oil or coconut oil, or in a mineral oil such as liquid paraffin. The oily suspensions may contain a thickening agent, for example beeswax, hard paraffin or cetyl alcohol. Sweetening agents such as those set forth above, the flavoring agents may be added to provide a palatable oral preparation. These compositions may be preserved by the addition of an antioxidant such as ascorbic acid.
Dispersible powders and granules suitable for preparation of an aqueous suspension by the addition of water provide the active ingredient in admixture with a dispersing or wetting agent, suspending agent and one or more preservatives. Suitable dispersing or wetting agents and suspending agents are exemplified by those already mentioned above. Additional excipients, for example sweetening, flavoring and coloring agents, may also be present.
The pharmaceutical compositions of the invention may also be in the form of oil-in-water emulsions. The oily phase may be a vegetable oil, for example olive oil or arachis oils, or a mineral oil, for example liquid paraffin or mixtures of these. Suitable emulsifying agents may be naturally-occurring gums, for example gum acacia or gum tragacanth, naturally-occurring phosphatides, for example soy bean, lecithin, and esters or partial esters derived from fatty acids and hexitol anhydrides, for example sorbitan mono-oleate, and condensation products of the said partial esters with ethylene oxide, for example polyoxyethylene sorbitan monooleate. The emulsions may also contain sweetening and flavoring agents.
Syrups and elixirs may be formulated with sweetening agents, for example glycerol, propylene glycol, sorbitol or sucrose. Such formulations may also contain a demulcent, a preservative and flavoring and coloring agents. The pharmaceutical compositions may be in the form of a sterile injectable aqueous or oleagenous suspension. This suspension may be formulated according to the known art using those suitable dispersing or wetting agents and suspending agents which have been mentioned above. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent, for example as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose any bland fixed oil may be employed including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid find use in the preparation of injectables.
A compound of (I) may also be administered in the form of suppositories for rectal administration of the drug. These compositions can be prepared by mixing the drug with a suitable non-irritating excipient which is solid at ordinary temperatures but liquid at the rectal temperature and will therefore melt in the rectum to release the drug. Such materials are cocoa butter and polyethylene glycols.
For typical use, creams, ointments, jellies, solutions or suspensions, etc., containing the anti-inflammatory agents are employed.
Dosage levels of the order from about 1 mg to about 100 mg per kilogram of body weight per day are useful in the treatment of the above-indicated conditions (from about 50 mg to about 5 gms. per patient per day). For example, inflammation is effectively treated and anti-pyretic and analgesic activity manifested by the administration from about 25 to about 75 mg of the compound per kilogram of body weight per day (about 75 mg to about 3.75 gms per patient per day). Advantageously, from about 5 mg to about 50 mg per kilogram of body weight per daily dosage produces highly effective results (about 250 mg to about 2.5 gm per patient per day).
The amount of active ingredient that may be combined with the carrier materials to produce a single dosage form will vary depending upon the host treated and the particular mode of administration. For example, a formulation intended for the oral administration of humans may contain from 5 mg to 5 gm of active agent compounded with an appropriate and convenient amount of carrier material which may vary from about 5 to about 95 percent of the total composition. Dosage unit forms will generally contain between from about 25 mg to about 500 mg of active ingredient.
It will be understood, however, that the specific dose level for any particular patient will depend upon a variety of factors including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, route of administration, rate of excretion, drug combination and the severity of the particular disease undergoing therapy.
D. Biological data supporting the utility of compounds within the scope of the invention
The compounds of formula (I) have been found to be PAF inhibitors, as shown below in Table I, by a published bioassay. See. T. Y. Shen et al., Proc. Nat. Acad. Sci., U.S.A., 82, 672 (1985); and S. B. Hwang et al., Biochem., 22, 4756 (1983).
TABLE I______________________________________% Inhibition of PAF Receptor by the Compounds ofFormula (I) ##STR7## % Dose Inhibi-X n R.sup.8 R.sup.2 R.sup.3 (μM) tion______________________________________3,4- -- CH.sub.2 CH.sub.2 CH.sub.3 H 3a, α- 5 90-95di-OCH.sub.3 OCH.sub.3 1 83-89 0.3 73-76 0.1 58-59 0.03 30-333,4- -- CH.sub.2 CH.sub.2 CH.sub.3 H 3a, β- 5 61di-OCH.sub.3 OCH.sub.3 1 313,4- -- H allyl 3a, β- 5 57di-OCH.sub.3 OCH.sub.3 1 263,4- -- allyl H 3a, α - 1 68di-OCH.sub.3 OC.sub.2 H.sub.5 0.3 423,4- -- allyl H 3a, β- 5 73di-OCH.sub.3 OC.sub.2 H.sub.5 1 45______________________________________
The following examples serve to illustrate but are not intended to limit the scope of the present invention.
EXAMPLE 1
5-Allyl-2-(3,4-dimethoxyphenyl)-3-acetoxy-3-methyl-2,3,3a,6-tetra-hydro-6-oxobenzofuran
Step A: Preparation of 3-Allyloxyphenol
A solution of resorcinol (40 g, 0.4 mol) and allyl bromide (32 g, 0.26 mol) in acetone (500 ml) containing potassium carbonate (55 g, 0.4 mol) was heated, with stirring, under reflux for 10 hours. The mixture was filtered, and the filtrate was evaporated to dryness. The residue was purified by means of PrepPak 500/silica on a Waters Associates Prep LC/System 500 at 250 ml/min using hexane-ethyl acetate (8:1, v/v) as a liquid phase. 3-Allyloxyphenol was isolated as a colorless oil (20 g, 51% based on ally bromide); NMR (chloroform-d): δ4.78 (s, OH), 4.55 (d, J=5.5 Hz, CH 2 CH═CH 2 ), 5.29-5.50 (m, CH 2 CH═CH 2 ), 6.07 (m, CH 2 CH═CH 2 ), 7.18 (t, J=8.5 Hz, H-5), 6.46-6.58 (m, remaining Ar--H).
Anal. Calc. for C 9 H 10 O 2 : C, 71.98; H, 6.71. Found: C, 71.99; H, 6.63.
Step B: Preparation of Ethyl 3,4-dimethoxycinnamate
Carbethoxymethylene triphenylphosphorane (150 g, 0.3 mol) was added to a solution of 3,4-dimethoxybenzaldehyde (50 g, 0.3 mol) in dry dichloromethane (150 ml), and the mixture was stirred at room temperature overnight. The solution was concentrated to about 50 ml, and the precipitate was filtered off and washed with hexane-dichloromethane (4:1, v/v). The combined filtrates were evaporated to a residue, which was purified by silica gel chromatography using hexane-ethyl acetate (9:1, v/v) as the eluant. The title compound was isolated as a crystalline mass (65 g, 91%), m.p. 52°-53° C.
Anal. Calc. for C 13 H 16 O 4 : C, 66.07; H, 6.83. Found: C, 66.18; H, 6.77.
Step C: Preparation of 3,4-Dimethoxycinnamyl Alcohol
3,4-Dimethoxycinnamyl alcohol was prepared by one of the following procedures:
(a) A solution of lithium aluminum hydride (0.02 mol) in diethyl ether (20 ml) was added dropwise to a solution of ethyl 3,4-dimethoxycinnamate (9.4 g, 0.04 mol) in diethyl ether (150 ml), and the mixture was heated under reflux for 1 hour. Water (15 ml) and 2.5N sodium hydroxide (5 ml) were added to the cooled solution, and the precipitate was filtered off and washed with ether. The combined filtrates were washed with water, dried, and evaporated to dryness. The crude product was put on a column of silica gel and eluted with hexane-ethyl acetate (1.5:1, v/v). 3,4-Dimethoxycinnamyl alcohol was isolated as a crystalline mass (5.0 g, 65%), m.p. 76°-76.5° C.
(b) A solution of lithium aluminum hydride (0.1 mol) in THF (100 ml) was added dropwise to a stirred suspension of 3,4-dimethoxycinnamic acid (41.6 g, 0.2 mol) in THF (150 ml) at room temperature. After the addition, the mixture was stirred for 2 hous, and the solution was evaporated in vacuo to a residue, which was partitioned between dichloromethane and aqueous sodium hydroxide. The organic layer was washed three times with water, dried, and evaporated to an oil. Crystallization from ethyl acetate-hexane gave 3,4-dimethoxycinnamyl alcohol (24 g, 62%), m.p. 76°-77° C.
Anal. Calc. for C 11 H 14 O 3 : C, 68.00; H, 7.27. Found: C, 67.96; H, 7.15.
Step D: Preparation of 3,4-Dimethoxycinnamyl Allyloxyphenyl Ether
Diethyl azodicarboxylate (26.1 g, 0.15 mol) and triphenyl phosphine (39.3 g, 0.15 mol) were added to a solution of 3-allyloxyphenol (15 g, 0.1 mol) and 3,4-dimethoxycinnamyl alcohol (19.4 g, 0.1 mol) in THF (100 ml). The mixture was stirred at room temperature overnight, and ethyl ether was added. The precipitate was filtered off, and the filtrate was evaporated to a residue, which was purified by HPLC using hexane-ethyl acetate (4:1 v/v) as a liquid phase. 3,4-Dimethoxycinnamyl allyloxyphenyl ether was isolated as a crystalline mass (7.4 g, 23%), m.p. 60°-60.5° C.; NMR (CDCl 3 ): δ3.93, 3.94 (s, s, 2 OCH 3 ), 4.57 (d, t, J=5.5, 1.5, 1.5 Hz, CH 2 CH═CH 2 ), 4.71 (d, d, J=6.0, 1.5 Hz, CH═CHCH 2 ), 5.28-5.50 (m, CH 2 CH═CH 2 ), 6.10 (m, CH 2 CH═CH 2 ), 6.26-6.40 (m, CH═CHCH 2 ), 6.56-7.28 (m, ArH).
Anal. Calc. for C 20 H 22 O 4 : C, 73.60; H, 6.79. Found: C, 73.36; H, 6.81.
Step E: Preparation of Rac-(2S,3S)-5-allyl-6-hydroxy-2-(3,4-dimethoxypehnyl)-3-methyl-2,3-dihydrobenzofuran
A solution of 3,4-dimethoxycinnamyl allyloxyphenyl ether in diethylaniline (6 ml) was heated at 225° C. for 13 hours, cooled, and diluted with diehtyl ether (30 ml). The solution was washed with 2N HCl and water, dried, and evaporated to a residue, which was purified by flash column chromatography on silica gel using hexane-ethyl acetate (4:1, v/v) as the eluant. The crude product was isolated as a crystalline mass (1.3 g, 43%), and was used for oxidation without further purification. A portion of this material was fractionated by HPLC to give pure Rac-(2S,3S)-5-allyl-6-hydroxy-2-(3,4-dimethoxypehnyl)-3-methyl-2,3-dihydrobenzofuran, m.p. 98°-99° C.; NMR (CDCl 3 ): δ1.39 (d, J=7.0 Hz, CH 3 ), 3.40 (d, J=5.5 Hz, CH 2 CH═CH 2 ), 3.40 (m, H-3), 3.91, 3.92 (s, s, 2 OCH 3 ), 4.95 (s, OH), 5.10 (d, J=9.0 Hz, H-2), 5.17-5.26 (m, CH 2 CH═CH 2 ), 6.60 (m, CH 2 CH═CH 2 ), 6.44 (s, H-7), 6.90-7.02 (m, ArH).
Anal. Calc. for C 20 H 22 O 4 : C, 73.60; H, 6.79. Found: C, 73.38; H, 6.73.
Step F: Preparation of 5-Allyl-2-(3,4-dimethoxyphenyl)-3-acetoxy-3-methyl-2,3,3a,6-tetrahydro-6-oxobenzofuran and related compounds
Lead tetraacetate (275 mg, 0.6 mmol) was added to a solution of Rac-(2S,3S)-5-allyl-6-hydroxy-2-(3,4-dimethoxypehnyl)-3-methyl-2,3-dihydrobenzofuran (100 mg, 0.3 mmol) in dry methanol (10 ml), and the mixture was stirred at room temperature for 1.5 hours and evaporated to dryness. The products were extracted with dichloromethane and separated by flash column chromatography on silica gel (hexane-ethyl acetate, 4:1 to 2:1, v/v) followed by HPLC (silica gel; hexane-tetrahydrofuran, 4:1, v/v). The first eluted compound is rac-denudatin B (9.1 mg), NMR (CDCl 3 ): δ1.15 (d, J=7.0 Hz, CH 3 ), 2.21 (m, H-3), 3.16 (s, OCH 3 ), 3.19 (m, CH 2 CH═CH 2 ), 3.92 (s, 2ArOCH 3 ), 5.12-5.21 (m, CH 2 CH═CH 2 ), 5.38 (d, J=9.5 Hz, H-2), 5.86 (s, H-7), 5.91 (m, CH 2 CH═CH 2 ), 6.30 (t, J=1.5 Hz, H-4), 6.83-6.92 (m, ArH). The second spot was identified as rac-kadsurenone (6.2 mg), NMR (CDCl 3 ): 1.12 (d, J=7.0 Hz, CH 3 ), 2.69 (q, d, J=7.0., 1.5 Hz, H-3), 3.04 (s, OCH 3 ), 3.15 (d, J=8.0 Hz, CH 2 CH═CH 2 ), 3.89, 3.90 (s, s, 2ArOCH 3 ), 5.11 (d, t, J=13, 1.5 Hz, CH 2 CH═CH 2 ), 5.12 (d, t, J=17, 2 Hz, CH 2 CH═CH 2 ), 5.24 (s, H-2), 5.85 (m, CH 2 CH═CH 2 ), 5.89 (s, H-7), 6.22 (t, J=1.5 Hz, H-4), 6.86 (d, J=8.5 Hz, H-5'), 6.90 (d, d, J=8.5, 2 Hz, H-6'), 7.02 (d, J=2.0 Hz, H-2'). The epimeric acetates (24.4 mg, about 1:1 mixture) were separated by HPLC into two isomers: the β-isomers, 5-allyl-2-(3,4-dimethoxyphenyl)-3a,β-acetoxy-3-methyl-2,3,3a,6 -tetrahydro-6-oxobenzofuran. (CDCl 3 ): δ1.32 (d, J=7.0 Hz, CH 3 ), 2.14 (s, OAc), 2.58 (d, J=7.5 Hz, CH 2 CH═CH 2 ), 3.08 (m, H-3), 3.94, 3.95 (s, s, 2ArOCH 3 ), 5.07 (d, J=8.5 Hz, H-2), 5.10-5.21 (m, CH 2 CH═CH 2 ), 5.73 (s, H-7), 5.81 (m, CH 2 CH═CH 2 ), 6.13 (d, J=2.5 Hz, H-4), 6.94 (ArH); and the α-isomer, 5-allyl-2-(3,4-dimethoxyphenyl)-3a,α-acetoxy-3-methyl-2,3,3a,6-tetrahydro-6-oxobenzo-furan. NMR (CDCl 3 ): δ1.34 (d, J=7.0 Hz, CH 3 ), 2.13 (s, OAc), 2.59 (d, J=7.5 Hz, CH 2 CH═CH 2 ), 3.07 (m, H-3), 3.94, 3.95 (s, s, 2OCH 3 ), 5.11 (d, J=7.5 Hz, H-2), 5.10-5.20 (m, CH 2 CH═CH 2 ), 5.75 (s, H-7), 5.79 (m, CH 2 CH═CH 2 ), 6.14 (d, J=2.5 Hz, H-4), 6.91-6.96 (m, ArH).
Rsolution of the product was accomplished by a Chiralpak column of -20° C. using hexane-2-propanol (9:1, v/v) as a liquid phase.
EXAMPLE 2
3a-Methoxy-3-(3,4,5-trimethoxyphenyl)-5-propyl-2,3,3a,6-tetrahydro-6-oxobenzofuran
Step A: Preparation of ω-(3-Allyloxyphenoxy)-3,4,5-trimethoxyacetophenone
Potassium carbonate (13.3 g, 0.096 mol) was added to a solution of 3-allyoxyphenol (12 g, 0.08 mol) and 3,4,5-trimethoxyphenacylbromide (21.9 g, 0.096 mol) in acetone (250 ml), and the mixture was heated under reflux for 8 hours. It was filtered and the filtrate was evaporated to a residue, which was purified by HPLC (hexane-ethyl acetate; 2:1, v/v). The title compound was isolated as a crystalline mass; recrystallization from diethyl ether-petroleum ether gave pure ω-(3-allyloxyphenoxy)-3,4,5-trimethoxyacetophenone (8.6 g, 36%), m.p. 64°-65° C.
Step B: Preparation of 5-Allyl-6-hydroxy-3-(3,4,5-trimethoxyphenyl)benzofuran
A solution of ω-(3-allyloxyphenoxy)-3,4,5-trimethoxyacetophenone (3 g) in diethylaniline (3 g) was heated in a sealed tube at 235° C. for 5 hours cooled, and put on a column of silica gel to give 540 mg of 5-allyl-6-hydroxy-3-(3,4,5-trimethoxyphenyl)benzofuran. In addition, the corresponding 5-allyl-4-hydroxy isomer and the 7-allyl-6-hydroxy derivative were also isolated.
Step C: Preparation of 6-Hydroxy-3-(3,4,5-trimethoxyphenyl)-5-propyl-2,3-dihydrobenzofuran
A solution of 5-allyl-6-hydroxy-3-(3,4,5-trimethoxyphenyl)benzofuran (130 mg) in glacial acetic acid (1 ml) containing 10% palladium-on-charcoal (50 mg) was hydrogenated for 2.5 h. The mixture was filtered and the filtrate was evaporated to give 6-hydroxy-3-(3,4,5-trimethoxyphenyl)-5-propyl-2,3-dihydrobenzofuran (90 mg).
Step D: Preparation of 3a-Methoxy-3-(3,4,5-trimethoxyphenyl)-5-propyl-2,3,3a,6-tetrahydro-6-oxo-benzofuran
Lead tetraacetate (200 mg) was added to a solution of 6-hydroxy-3-(3,4,5-trimethoxyphenyl)-5-propyl-2,3-dihydrobenzofuran (100 mg) in dry methanol (10 ml), and the mixture was stirred at room temperature for 1 hour. The solution was evaporated to a residue, which was put on a flash column of silica gel and eluted with hexane-ethyl acetate (4:1, v/v). The title compound was isolated as a mixture of epimers.
EXAMPLE 3
3a-Methoxy-2-(3,4,5-trimethoxyphenyl)-5-propyl-2,3,3a,6-tetrahydro-6-oxo-benzofuran
Step A: Preparation of 6-Hydroxy-3-(3,4,5-trimethoxyphenyl)-5-propylbenzofuran
A solution of 5-allyl-6-hydroxy-3-(3,4,5-trimethoxyphenyl)benzofuran (300 mg) in ethyl acetate (2 ml) containing 5% palladium-on-charcoal was hydrogenated for 20 minutes. The mixture was filtered and the filtrate was evaporated to give 6-Hydroxy-3-(3,4,5-trimethoxyphenyl)-5-propylbenzofuran.
Step B: Preparation of 6-Hydroxy-2-(3,4,5-trimethoxyphenyl)-5-propylbenzofuran
Compound 6-hydroxy-3-(3,4,5-trimethoxyphenyl)-5-propylbenzofuran (1 g) was heated with stirring, with polyphosphoric acid at 130° C. for 20 minutes. It was cooled and the mixture was partitioned between diethyl ether and water. The organic layer was dried and evaporated to a residue, which was put on a flash column of silica gel and eluted with hexane-ethyl acetate (4:1, v/v). In addition to the product 6-Hydroxy-2-(3,4,5-trimethoxyphenyl)-5-propylbenzofuran (200 mg).
Step C: Preparation of 6-Hydroxy-2-(3,4,5-trimethoxyphenyl-5-propyl-2,3-dihydrobenzofuran
A solution of 6-Hydroxy-2-(3,4,5-trimethoxyphenyl)-5-propylbenzofuran (200 mg) in glacial acetic acid (1 ml) containing 10% palladium-on-charcoal was hydrogenated for 2.5 hours. The mixture was filtered and the filtrate was evaporated in vacuo to give 6-hydroxy-2-(3,4,5-trimethoxyphenyl)-5-propyl-2,3-dihydrobenzofuran (155 mg).
Step D: Preparation of 3a-Methoxy-2-(3,4,5-trimethoxyphenyl)-5-propyl-2,3,3a,6-tetrahydro-6-oxo-benzofuran
Lead tetracetate (200 mg) was added to a solution of 6-hydroxy-2-(3,4,5-trimethoxyphenol)-5-propyl-2,3-dihydrobenzofuran (100 mg) in dry methanol (10 ml), and the mixture was stirred at room temperature for 1 hour. It was concentrated to dryness, and the residue was partitioned between diethyl ether and water. The organic layer was dried and evaporated to residue, which was put on a flash column of silica gel and eluted with hexane-ethyl acetate (4:1, v/v). 3a-methoxy-2-(3,4,5-trimethoxyphenyl)-5-propyl-2,3,3a,6-tetrahydro-6-oxo-benzofuran was isolated as an epimeric mixture.
EXAMPLE 4
3a-acetoxy-2-(3,4-dimethoxyphenyl)-3-methyl-5-n-propyl-2,3,3a,6-tetrahydro-6-oxobenzofuran and related compounds
Step A: Preparation of (2S,3S)-6-Hydroxy-2-(3,4-dimethoxyphenyl)-3-methyl-5-propyl-2,3-dihydrobenzofuran
A solution of Rac-(2S,3S)-5-allyl-6-hydroxy-2-(3,4-dimethoxyphenyl)-3-methyl-2,3-dihydrobenzofuran (1.28 g) in ethyl acetate (30 ml) containing 10% palladium-on-charcoal (40 mg) was hydrogenated at 20 p.s.i. for 2 hours. The mixture was filtered and the filtrate was evaporated to give (2S,3S)-6-Hydroxy-2-(3,4-dimethoxyphenyl)-3-methyl-5-propyl-2,3-dihydrobenzofuran (1.2 g); n.m.r. (CDCl 3 ): δ0.99 (t, CH 2 CH 2 CH 3 ), 1.37 (d, CH 3 --3), 1.65 (m, CH 2 CH 2 CH 3 ), 2.55 (t, CH 2 CH 2 CH 3 ), 3.38 (m, H-3), 3.90, 3.91 (s, s, 2OCH 3 ), 4.69 (b, OH), 5.07 (d, J 9.0 Hz, H-2), 6.06-7.01 (Ar--H), 6.38 (s, H-7).
Step B: Preparation of 3a-acetoxy-2-(3,4-dimethoxyphenyl)-3-methyl-5-n-propyl-2,3,3a,6-tetrahydro-6-oxo-benzofuran and related compounds
Lead tetracetate (275 mg, 0.6 mmol) was added to a solution of (2S,3S)-6-Hydroxy-2-(3,4-dimethoxyphenyl)-3-methyl-5-propyl-2,3-dihydrobenzofuran (100 mg), 0.3 mmol) in dry methanol (10 ml), and the mixture was stirred at room temperature for 1.5 hours and evaporated to dryness. The products were extracted with dichloromethane and separated by flash chromatography on silica gel (hexane-ethyl acetate, 4:1 to 2:1, v/v) followed by HPLlC (silica gel; hexane-tetrahydrofuran, 4:1, v/v). The first eluted compound was (2S,3S,3aR)-2-(3,4-dimethoxyphenyl)-3a-methoxy-3-methyl-5-n-propyl-2,3,3a,6-tetrahydro-6-oxo-benzofuran (9 mg), n.m.r. (CDCl 3 ): δ0.99 (t, J 7.5 Hz, CH 2 CH 2 CH 3 ), 1.16 (d, J 7.0 Hz, CH 3 --3), 1.55 (m, CH 2 CH 2 CH 3 ), 2.20 (m, H-3), 2.39 (m, CH 2 CH 2 CH 3 ), 3.16 (s, OCH 3 ), 3.92 (s, s 2Ar--OCH 3 ), 5.38 (d, J 9.5 Hz, H-2), 5.84 (s, H-7), 6.27 (s, H-4), 6.84-6.93 (Ar--H). The second spot was identified as (2S,3S,3aS)-2-(3,4-dimethoxyphenyl)-3a-methoxy-3-methyl-5-n-propyl-2,3,3a,6-tetrahydro-6-oxo-benzofuran (6 mg), n.m.r. (CDCl 3 ): 0.96 (t, J 7.5 Hz, CH 2 CH 2 CH 3 ), 1.15 (d, J 7.0 Hz, CH 3 --3), 1.53 (m, CH 2 CH 2 CH 3 ), 2.38 (m, CH 2 CH 2 CH 3 ), 2.72 (m, H-3), 3.05 (s, OCH 3 ), 3.90, 3.91 (s, s, 2OCH 3 ), 5.26 (s, H-2) 5.92 (s, H-7), 6.22 (s, H-4), 6.88-7.06 (m, Ar--H). The corresponding epimeric acetates (24 mg, about 1:1 mixture) were separated by HPLC: (2S,3S,3aR)-3a-Acetoxy-2-(3,4-dimethoxyphenyl)-3-methyl-5-n-propyl-2,3,3a,6-tetrahydro-6-oxo-benzofuran n.m.r. (CDCl 3 ): 0.93 (t, J 7.0 Hz, CH 2 CH 2 CH 3 ), 1.34 (d, J 7.0 Hz, CH 3 --3), 1.40 (m, CH 2 CH 2 CH 3 ), 1.83 (m, CH 2 CH 2 CH 3 ), 2.13 (s, OAc), 3.05 (m, H-3), 3.94, 3.95 (s, s, 2OCH 3 ), 5.08 (d, J 8.2 Hz, H-2), 5.73 (s, H-7), 6.15 (d, J 1.5 Hz, H-4), 6.88-6.99 (m, Ar--H); and (2S,3S,3aS)-3a-Acetoxy-2-(3,4-dimethoxyphenyl)-3-methyl-5-n-propyl-2,3,3a,6-tetrahydro-6-oxo-benzofuran, n.m.r. (CDCl 3 ): δ0.92 (t, J 7.02 Hz, CH 2 CH 2 CH 3 ), 1.34 (d, J 7.0 Hz, CH 3 --3), 1.38 (m, CH 2 CH 2 CH 3 ), 1.83 (m, CH 2 CH 2 CH 3 ), 2.13 (s, OAc), 3.07 (m, H-3), 3.94 (s, 2OCH 3 ), 5.10 (d, J 7.6 Hz, H-2), 5.73 (s, H-7), 6.15 (d, J 1.5 Hz, H-4), 6.84-6.94 (m, Ar--H).
EXAMPLE 5
(2S,3S,3aS)-2-(3,4-Dimethoxyphenyl)-3a-methoxy-3-methyl-5-n-propyl-2,3,3a,6-tetrahydro-6-methoxyiminobenzofuran
(2S,3S,3aS)-2-(3,4-Dimethoxyphenyl)-3a-methoxy-3-methyl-5-n-propyl-2,3,3a,6-tetrahydro-6-methoxyiminobenzofuran was prepared from (2S,3S,3aS)-2-(3,4-dimethoxyphenyl)-3a-methoxy-3-methyl-5-n-propyl-2,3,3a,6-tetrahydro-6-oxobenzofuran and methoxylamine hydrochloride in pyridine at room temperature for 3 days. The product was purified by flash column chromatography on silica gel (hexane-ethyl acetate, 9:1, v/v) followed by HPLC to afford (2S,3S,3aS)-2-(3,4-dimethoxyphenyl)-3a-methoxy-3-methyl-5-n-propyl-2,3,3a,6-tetrahydro-6-methoxyiminobenzofuran, n.m.r. (CDCl 3 ): δ0.98 (t, J 7.5 Hz, CH 2 CH 2 CH 3 ), 1.11 (d, CH 3 --3), 1.64 (m, CH 2 CH 2 CH 3 ), 2.52 (m, CH 2 CH 2 CH 3 ), 3.0 (s, OCH 3 ), 3.84 (s, Ar--OCH 3 ), 4.04 (s, NOCH 3 ), 5.07 (s, H-2), 5.72 (s, H-7) 6.48 (s, H-4), 6.87-7.12 (m, Ar--H).
EXAMPLE 6
(2S,3S,3aS)-5-Allyl-2-(3,4-dimethoxyphenyl)-3a-ethoxy-3-methyl-2,3,3a,6-tetrahydro-6-oxo-benzofuran
Following substantially the same procedures as described in Example 2, Step E, except that ethanol was used in place of methanol there were obtained two products: (2S,3S,3aR)-5-allyl-2-(3,4-dimethoxyphenyl)-3a-ethoxy-3-methyl-2,3,3a,6-tetrahydro-6-oxo-benzofuran, n.m.r. (CDCl 3 ): δ1.15 (t, J 7.0 Hz, OCH 2 CH 3 ), 1.15 (d, J 7.0 Hz, CH 3 --3), 2.17 (m, H-3), 3.17 (m, CH 2 CH═CH 2 ), 3.33 (q, OCH 2 CH 3 ), 3.92 (s, 2OCH 3 ), 5.10-5.22 (m, CH 2 CH═CH 2 ), 5.41 (d, J 9.5 Hz, H-2), 5.82 (s, H-7), 6.33 (t, J 1.5 Hz, H-4), 6.82-6.92 (m, Ar--H); and (2S,3S,3aS)-5-allyl-2-(3,4-dimethoxyphenyl)-3a-ethoxy-3-methyl-2,3,3a,6-tetrahydro-6-oxo-benzofuran, n.m.r. (CDCl.sub. 3): δ0.95 (t, J 7.0 Hz, OCH 2 CH 3 ), 1.12 (d, J 7.5 Hz, CH 3 --3), 2.76 (m, H-3), 3.15 (m, CH 2 CH═CH 2 ), 3.28 (q, OCH 2 CH 3 ), 3.92, 3.93 (s, s, 2OCH 3 ), 5.07-5.20 (m, CH 2 CH═CH 2 ), 5.26 (s, H-2), 5.89 (s, H-7), 5.91 (m, CH 2 CH═CH 2 ), 6.30 (s, H-4), 6.80-7.06 (m, Ar--H).
EXAMPLE 7
(2S,3S,3aS)-5-Allyl-2-(3,4,5-trimethoxyphenyl)-3a-methoxy-3-methyl-2,3,3a,6-tetrahydro-6-oxo-benzofuran
Following substantially the same procedures of Example 1, Steps A to F, there were obtained the following intermediates and products:
3,4,5-Trimethoxycinnamyl allyloxyphenyl ether, in 16.2% yield from 3-allyloxyphenol and 3,4,5-trimethoxycinnamyl alcohol. Mass spectrum: m/e 356 (M+.);
Rac-(2S,3S)-5-allyl-6-hydroxy-2-(3,4,5-trimethoxyphenyl)-3-methyl-2,3-dihydrobenzofuran in 24% yield, m.p. 166°-167° C.; mass spec. m/e 356 (M+.)
Anal. Calc. for C 21 H 24 O 5 : C, 70.77; H, 6.79. Found: C, 70.35; H, 6.74;
(2S,3S,3aS)-5-Allyl-2-(3,4,5-trimethoxyphenyl)-3a-methoxy-3-methyl-2,3,3a,6-tetrahydro-6-oxo-benzofuran, n.m.r. spectrum is in accord with the structure and indicating a mixture of epimers. | Substituted 2,3,3a,6-tetrahydro-6-oxobenzofuran derivatives have been prepared. These neolignans are found to have potent and specific PAF (Platelet-Activating-Factor) antagonistic activities and thereby useful in the treatment of various diseases or disorders mediated by PAF, for example, pain, fever, inflammation, cardiovascular disorder, asthma, lung edema, allergic disorders, skin diseases, psoriasis, toxic shock syndrome and adult respiratory distress syndrome. | 2 |
BACKGROUND OF THE INVENTION
Weighting scales capable of rapidly weighing a series of flat articles have recently been developed. One type of such scale is a vibrating tray scale wherein a flat article is conveyed onto the platform of the scale, the conveying mechanism is removed from contact with the article, a holding device holds the flat article firmly on the platform, and the platform is oscillated thereby causing flex-members that support the platform to oscillate. A transducer is attached to one of the flex-members to measure the frequency of oscillation of the platform. Based upon such measurement, the weight of the article on the platform can be determined. Details relative to the structure of a vibrating tray scale, the method of operation and the method of determining the mass of an article thereon are fully described in U.S. Pat. No. 4,778,018. With such a scale, one is able to weigh articles at rate of two to four articles per second. The rate of weighing depends upon the size of the articles to be weighed as well as the characteristics of the particular vibrating tray scale.
One of the important features of a vibrating tray scale is the need to lock the base of the scale when the tray is not being vibrated for purposes of obtaining the weight of an article on the tray. The base of the scale is that part which provides support to the flex-members and the base in turn is supported by a frame or housing. Various locking mechanisms have been used with success for the purpose of achieving stabilization of the base during the time articles are transported on and off the tray. In U.S. Pat. No. 4,778,018 a solenoid type of device is used that clamps onto the base from the top and bottom. In U.S. Pat. No. 4,836,311 a mechanism is described that not only provides a locking mechanism but also initiates the oscillation of the tray. In U.S. Pat. No. 4,844,188 a mechanical locking device is shown that is activated to lock the base upon the article transporting mechanism being activated and deactivated when the article is to be weighed. Although all of these locking mechanisms have worked satisfactorily well, a need still exists for a relatively simple, reliable and fast locking mechanism.
SUMMARY OF THE INVENTION
A locking mechanism for a vibrating tray scale has been conceived that is not only simple, reliable and fast, but also contributes to greater weighing accuracy. This locking mechanism is used to lock the base of the weighing scale during the time flat articles are transported onto and off the tray before and after being weighed. The locking mechanism includes an armature plate that is attached to the base of the scale and an electromagnetic device that is secured by a flexure spring to the frame of the scale.
Upon energization of the electromagnetic device, the biasing force of the spring is overcome and the electromagnet is attracted to and engages the armature to hold the base of the scale stationary. While the base is stationary, articles are transported onto and off the platform. During the weighing of the the articles, the electromagnet is de-energized and a spring removes the electromagnetic from contact with the armature. During the period the electromagnetic device is disabled, an article can be weighed. After weighing, the base will be locked again by energizing the electromagnet, the article will be removed from the tray, and another article will be placed thereon.
The greater accuracy that accompanies use of the instant locking mechanism results from the self compensating effect of the mechanism; whereby, the base is located in the position at which it comes to rest without being moved into a set position as was done with prior locking mechanisms.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a cross sectional view of a vibrating tray scale that incorporates the instant invention;
FIG. 2 is a cross sectional view of the locking mechanism for the vibrating tray scale in the unlocked portion taken along the lines 2--2 of FIG. 1;
FIG. 3 is a cross sectional view of the locking mechanism in the locked position taken along the lines 2--2 of FIG. 1; and
FIG. 4 is a plan view of a portion of the locking mechanism shown in FIG. 2 and 3 and taken along the lines 4--4 of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With initial reference to FIG. 1, a vibrating tray scale is shown generally at 10 and includes a frame 12 to which two upright plates 14 are secured. A pair of angular leaf springs 16 (only two being shown) are secured to each upright plate 14, as for example with bolts 18, and the springs 16 support a base 20. Four flex-members 22 (only two being shown) are supported by the base 20 and in turn support a tray 24. One of the flex-members 22 has a transducer 23 attached thereto for measuring oscillation of the flex-members. The details of the flex-members 22 are shown and described in U.S. Pat. No. 4,836,313 and will not be described in detail.
The tray 24 has a plurality of openings 26 therein. Two posts 28 are supported by the frame 12 and each has an opening 30. Each opening 30 receives a spring 32 therein. A carriage 38 has openings 40, each of which receives a post 28 and a spring 32, the springs having the effect of urging the carriage upwardly. The carriage 38 includes a plurality of laterally aligned pairs of projections 42, only one of each lateral pair being shown in FIG. 1. Each projection has an opening 44. The openings 44 of paired projections 42 receive a shaft 46 that rotatably supports a roller 48. Reference can be had to U.S. Pat. No. 4,844,188 for a more detailed description to the carriage 38 and associated components.
A number of small rollers is supported by a wall 51 including a drive roller 50 and a plurality of idler rollers 52, 54, 56, and 58. The drive roller 50 is secured to the shaft 53 of a motor (not shown). The rollers 52 and 54 are idler rollers that are rotatably supported by pins 60 secured to the wall 51. The roller 58 is supported by a one way clutch 62 that in turn is mounted on a pin 63 secured the wall 51. The roller 56 is rotatably supported by a pin 61 that is attached to a pivot arm 64. The pivot arm 64 is pivotally mounted on a pin 65 that is secured to the wall 51 and an expansion spring 66 has one of its ends attached to the pivot arm and its other end attached to an abutment 68 secured to the wall 51. This allows the roller 56 to be pivotally moved and urged in a counter-clockwise direction by the spring 66. Pins 72 are secured to the frame (by means not shown) intermediate the projections 42 and rotatably support rollers 74 and another roller 76 is rotatably mounted on a pin 78, the later being supported by the frame (by means not shown). A belt 80 is trained about the rollers 48, 50, 52, 54, 56, 58, 74 and 76. By actuation of the one way clutch 62, thereby braking the roller 68, as the belt is being driven by the drive roller 50, the roller 56 will be driven in a clockwise direction as seen in FIG. 1 and urged to the right so as to "contract" the belt 80 to cause the carriage 38 to be pulled downwardly to overcome the springs 32 of the brackets 28. Upon release of the one way clutch 62, the rollers 58 will rotate freely and the springs 52 will urge the carriage 38 upwardly. Reference can be had to U.S. Pat. No. 4,844,188 for a full description as to the functioning of such a pull down and release mechanism. It will be appreciated that other pull down and release mechanisms can be used as well and the type of such mechanism does not form part of the instant invention.
Located above the tray 24 and in registration with each roller 48 are a plurality of arms 82 each of which has a paddle 84 at the end thereof. The arms 84 are supported by the tray 24 by means not shown. Each paddle 84 engages the belt 80 portions trained about some of the rollers 48 when the carriage 38 is in its uppermost position. In such a position, when the drive roller 50 is rotated, and the one way clutch 62 is disengaged, mail placed between the nip of the first paddle 84 and the belt 80 will be conveyed onto the platform 24 until such time as the flat is observed (by means not shown). After the flat is observed, the one way clutch will be activated and the carriage 28 will be lowered. Again, reference can be had to U.S. Pat. No. 4,844,188 for details of this operation. With the carriage 38 lowered, the article on the platform will be weighed as described in U.S. Pat. No. 4,778,018.
What has been shown and described to this point does not form part of the instant invention and has been included only for the purpose of describing the environment in which the instant invention can be practiced.
Referring now particularly to FIGS. 2 and 3, a locking mechanism is shown at 85 and includes a generally L shaped armature 86 having elongated, vertically extending openings 92 which is attached to the base 20 as by bolts 94 received within the elongated openings. An elongated, laterally extending block 96 is secured to the frame 12 and supports a rigid platform 98 which has an opening 100 therein. Attached to the platform 98 is one end of a leaf spring 102, which leaf spring has a base portion 104 that is attached to the platform 98 as by bolts 106. An electromagnet 108 has a button 110 at the top thereof and is secured to the leaf spring 102 by a bolt 111 that is receivable within the opening 100. Secured intermediate the electromagnet 108 and, leaf spring 102 is an L-shaped guard 109 the vertical extent of which is horizontally aligned with the top of the button 110. A power line 112 is connected to the electromagnetic 108 and is attached to any convenient power supply 114 (shown only in FIG. 3). With such configuration, the leaf spring 102 urges the electromagnet 108 downwardly away from the armature 86 when no power is supplied to the electromagnet 108 by the power supply 114.
In operation, the vibrating tray scale 10 requires stabilization of the base 20 during non weighing time in order to keep the base from swaying due to vibrations created when an article is being conveyed onto the tray 24. After an article has been transported onto the scale tray 24, the transport carriage 38 is lowered into the article non contacting, weighing position, the locking mechanism 85 is de-energized, thereby allowing the spring 102 to pull to button 110 away from the armature 86 and releasing the base 20 to free the system for weighing. At the end of the weighing cycle, the locking mechanism 85 is re-energized by supply power from the power source 114 to restabilize the base.
When the electro magnet 108 of the locking mechanism 85 is energized, it is attracted to the armature 86 which is attached to the base 20 by the two adjusting screws 94. This causes the electro magnetic 108 to lift upwardly because of the magnet attraction to the armature 86 and become attached to the armature, thereby bending the leaf spring 102 as seen in FIG. 3. Since the spring 102 and the block 96 are connected as one piece, they form a mechanical connection between the base 20 and the electromagnet 85 thus effectively connecting the base to the frame 12. The effect is to physically lock the scale base 20 to the frame 12 and create potential energy in the leaf spring 102. When the electromagnet 108 is deenergized, the leaf spring 102 will assume its original shape, as seen in FIG. 2, to drive the the electromagnet to its lower position allowing a gap between the button 110 and the armature 86 thus freeing the scale base for weighing. For optimum performance, the preferred gap between the button 96 and the armature 86 is adjusted to 0.030 inches when the locking mechanism 85 is deenergized.
The advantages of the locking mechanism 85 shown and described are that of simplicity and low cost, self compensation, zero force, and high efficiency. The locking mechanism 85 of the instant invention contains few components and thus is simple in structure and inexpensive in construction. The self compensating factor is a result of the position of the scale base 20 relative to the frame 12 dependent on the leveling of the frame on the frame's support. Since the scale generally has no means to level itself, a requirement of the locking mechanism is to lock the base 20 in whatever position it may come to rest. A mechanism that uses detents, whether single or multiple, tends to produce a predetermined locking position for the scale base 12. This in turn effects the accuracy of the scale since this predetermined locking position may not be the natural locking position. The locking mechanism 85 of the instant invention has infinite positioning accuracy within its range and eliminates the positioning effect which reduces scale accuracy.
Prior mechanisms lock the base by pressing on the base scale. Upon release, these mechanisms impart a movement to the scale base 20. The locking mechanism 85 of the instant invention does not have this undesirable effect and thus there is a zero force imparted to the base 20 during release. Furthermore, prior locking mechanisms require approximately 200 milliamps at 60 volts, whereas the locking mechanism of the instant invention requires 40 milliamps at 40 volts for an improvement factor of 3.3.
The above embodiment has been given by way of illustration only and other embodiments of the instant invention will be apparent to those skilled in the art from consideration of the detailed description and the attached drawing. Accordingly, limitations on the instant invention are to be found only in the claims. | This invention relates to locking mechanism for a weighing scale capable of weighing flat articles at a high rate and with a high degree of accuracy. The locking mechanism of the instant invention is applicable to a vibrating tray type scale which requires a mechanism for stabilizing the base of the scale during periods when articles are being conveyed onto and off the tray of the scale. An electromagnetic locking mechanism has been conceived that provides advantageous for a vibrating tray scale. These advantages are simple construction, low cost, self compensating and zero force requirement. With a such locking mechanism, the vibrating tray scale functions more accurately and rapidly. | 6 |
TECHNICAL FIELD
The present invention relates generally to a combustion chamber for diesel engines, and more particularly, to improvements upon a swirl chamber used in association with a combustion chamber for diesel engines.
BACKGROUND ART
In general, diesel engines are notorious as a major source of environmental contaminants such as NOx and fumes. However, no effective measures have been accomplished for solving those problems. It is known that these problems are due to the incomplete combustion in the engine occurring because of inadequate mixing of air and fuel. To solve these problems, swirl-aided combustion systems are commonly used. Here is one example for tackling this problem, which is disclosed in Japanese Patent Laid-open Application No. 07-97924. Referring to FIG. 10 , the known combustion chamber fitted with a swirl chamber will be described:
In FIGS. 10A and 10B the right-hand side (toward the central axis 103 ) is called “rearward”, and the left-hand side (toward the cylinder liner 104 ) is “forward” each as designation for convenience only. The known combustion chamber shown in FIGS. 10A and 10 B is provided with a cylinder 101 having a cylinder head 105 , a reciprocating piston 102 , and a combustion chamber 109 . In addition, the cylinder head 105 is provided with a recess 106 in which a mouthpiece 107 is fitted. The mouthpiece 107 is provided with a top-open recess 107 a, and t15he recess 106 includes a bottom-open recess 106 a. The top-open recess 107 a and the bottom-open recess 106 a constitute a space 108 functioning as a swirl chamber, hereinafter the space being referred to as “swirl chamber 108 ”. The swirl chamber 108 communicates with the combustion chamber 109 through a main nozzle hole 111 having a center axis 113 . The main nozzle hole 111 is forwardly inclined toward the swirl chamber 108 . The mouthpiece 107 is additionally provided with a pair of sub-nozzle holes 102 112 , through which a secondary air is forced into the swirl chamber 108 on the compression stroke. The sub-nozzle holes 112 are symmetrically positioned on opposite sides of the central axis 113 - 114 as shown in FIG. 10 A.
Under the construction mentioned above, however, a major disadvantage is that the second air ejected through the sub-nozzle holes 112 does not reach the central part of the swirl chamber 108 , thereby failing to bring about effective swirls therein. In this way the conventional sub-nozzle holes 112 are not conducive to the full utilization of the secondary air.
The disadvantages mentioned above is due to the following arrangement of the sub-nozzle holes 112 : When a hypothetical sphere 115 is supposed about the center 107 c of the open end 107 b of the top-open recess 107 a, and the radius of the open end 107 b and that of the sphere 115 are respectively supposed to be 100% and 70%.
The sphere 115 having a radius of 70% passes outward, whereas the sphere 115 having a radius of 50% passes inward in FIGS. 10A and 10B . In this situation, the central axis 112 a- 112 b of each of the sub-nozzle holes 112 passes outside the sphere 115 .
In another aspect, when the mouthpiece 107 is seen from just above, the sub-nozzle holes 112 have their upper openings 112 c deviated from the center of the swirl chamber 108 so that even if every sub-nozzle hole is oriented vertically, the central axis 112 a- 112 b of each sub-nozzle hole 112 cannot pass inside the 50% sphere 115 .
Accordingly, an object of the present invention is to provide an improved swirl chamber capable of causing effective swirls to help air and fuel being well mixed, and dispersing the fuel well in the swirl chamber.
Another object of the present invention is to provide an improved swirl chamber capable of reducing the production of both NOx and fumes, not one or the other under the conventional system.
SUMMARY OF THE INVENTION
According to theThe present invention,is directed to a swirl chamber used in association with a combustion chamber, wherein thefor diesel engines. The combustion chamber is defined by a piston, a cylinder, and a cylinder head, includes a. A mouthpiece is fitted in a holerecess of the cylinder head, the hole havingrecess has a bottom-open recess, and the mouthpiece includingincludes a top-open recess, the. The bottom-open recess and the top-open recess constitutingconstitute a space for the swirl chamber; a. A main nozzle hole is produced through a base wall of the mouthpiece to allow the swirl chamber to effect communication between the combustion chamber and the swirl chamber; and a. A pair of sub-nozzle holes which are separated from the main nozzle hole,and are produced through the base wall of the mouthpiece, the. The holes beingare positioned on opposite sides of thea central axis of the main nozzle hole when the mouthpiece is seen from just above; wherein each of the sub-nozzle holes is arranged to pass inside a hypothetical sphere depicted around a center of an upper circle of the top-open recess and having a radius of 70% of a diameter of the upper circle of the top-open recess. A hypothetical sphere is centered at a center of an upper circle of the top- open recess. The hypothetical sphere has a radius of 70 % of a radius of the upper circle of the top - open recess and each of the sub - nozzle holes is arranged to pass a central axis of the sub - nozzles through an interior area of the hypothetical sphere.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is generally a diagrammatic view exemplifying a first embodiment of the present invention; FIG. 1A being a plan view, FIG. 1B being a cross-sectional view taken along the line B—B of FIG. 1A ; FIG. 1C being a bottom view, and FIG. 1D being a cross-sectional view taken along the line D—D;
FIG. 2 is generally a diagrammatic view exemplifying the nozzle hole in the mouthpiece shown in FIG. 1 ; FIG. 2A being a vertical cross-sectional side view of the mouthpiece, FIG. 2B being a perspective view of the nozzle hole; FIG. 2C being a diagrammatic view of the nozzle hole viewed in the direction indicated by the arrow C in FIG. 2A , and FIG. 2D being a bottom view of the nozzle hole;
FIG. 3 is generally a diagrammatic view exemplifying the swirl chamber shown in FIG. 1 ; FIG. 3A being a horizontal cross-sectional plan view of a cylinder incorporating a piston, and FIG. 3B being a cross-sectional side view of the swirl chamber and the surrounding part members;
FIG. 4 is a graph showing NOx content in the exhaust gases under the first embodiment shown in FIG. 3 , in comparison with a contrasted example 1 having no sub-nozzle holes;
FIG. 5 is a graph showing the amount of NOx and fumes exhausted under the first embodiment shown in FIG. 3 , in comparison with contrasted examples 1 and 2;
FIG. 6 is generally a graph showing the relationship between the cross-sectional area of the sub-nozzle holes and the characteristics of gases exhausted from the swirl chamber of FIG. 3 ; FIG. 6A showing variations in the amount of NOx in relation to the cross-sectional area; FIG. 6B showing variations in the amount of fumes in relation to the cross-sectional area; and FIG. 6C showing variations in the total amount of NOx and fumes in relation to the cross-sectional area;
FIG. 7 is generally a diagrammatic view exemplifying the mouthpiece of a second embodiment; FIG. 7A being a plan view, FIG. 7B being a cross-sectional view taken along the line B—B in FIG. 7A ; FIG. 7C being a bottom view, and FIG. 7D being a cross-sectional view taken along the line D—D in FIG. 7B ;
FIG. 8 is generally a diagrammatic view exemplifying the mouthpiece of a third embodiment; FIG. 8A being a plan view, FIG. 8B being a cross-sectional view taken along the line B—B in FIG. 8A ; FIG. 8C being a bottom view, and FIG. 8D being a cross-sectional view taken along the line D—D in FIG. 8B ;
FIG. 9 is generally a diagrammatic view exemplifying the mouthpiece of a fourth embodiment; FIG. 9A being a plan view, FIG. 9B being a cross-sectional view taken along the line B—B in FIG. 9A ; FIG. 9C being a bottom view, and FIG. 9D being a cross-sectional view taken along the line D—D in FIG. 9B ; and
FIG. 10 is generally a diagrammatic view exemplifying a known swirl chamber; FIG. 10A being a plan view of the mouthpiece and the piston, and FIG. 10B being a vertical cross-sectional side view of a swirl chamber and surrounding part members.
DESCRIPTION OF PREFERRED EMBODIMENTS
Throughout the drawings like numerals are used to designate like components, and in FIGS. 1B , 3 B, 7 B, 8 B, 9 B, and 2 A the right-hand side is “forward”, and the left-hand side is “rearward” for convenience of illustration only. A first embodiment is shown in FIGS. 1 to 6 , in which a pair of sub-nozzle holes 12 are provided upright in parallel with the central axis 3 of a cylinder 1 . This is the same with a second embodiment shown in FIG. 7 , but in the third embodiment shown in FIG. 8 and a fourth embodiment shown in FIG. 9 the sub-nozzle holes 12 are slightly converged and slightly diverged toward their top open ends, respectively. The feature common with all the embodiments is that the sub-nozzle holes are spaced from, and positioned symmetrically on opposite sides of, the main nozzle hole. In addition, the sub-nozzle holes are produced on the forward side.
In FIG. 3B a reciprocating piston 2 is provided inside a cylinder 1 along whose central axis 3 the piston 2 moves up and down. The cylinder 1 has a head 5 having a recess 6 in which a mouthpiece 7 is fitted. The recess 6 includes a bottom-open recess 6 a, and the mouthpiece 7 includes a top-open recess 7 a. The bottom-open recess 6 a and the top-open recess 7 a constitute a space 8 that is utilized as a swirl chamber. The cylinder 1 is provided with a combustion chamber 9 having a main nozzle hole 11 passing through the mouthpiece 7 . The combustion chamber 9 and the swirl chamber 8 communicate with each other through the main nozzle hole 11 , which is forwardly inclined toward the swirl chamber 8 from the combustion chamber 9 , as shown in FIG. 3 B. The mouthpiece 7 has an undersurface 7 d in a plane perpendicular to the central axis 3 of the cylinder 1 .
As best shown in FIG. 3B , a fuel jet nozzle 19 and a heat plug 20 are provided toward the swirl chamber 8 . The piston 1 is provided with a triangular recess 21 adapted to guide a gas flow, wherein the root portion of the recess 21 is positioned immediately below the main nozzle hole 11 , and as best shown in FIG. 3A , the recess 21 expands progressively far from the main nozzle hole 11 , thereby having a diminishing depth, as best shown in FIG. 3 B.
The principle underlying the combustion chamber 9 fixed with the swirl chamber 8 is as follows:
On the compression stroke the piston 2 rises, thereby introducing compressed air into the swirl chamber 8 to cause swirls therein. When the piston 2 reaches the top dead point, fuel is ejected through the ejection nozzle 19 . The fuel is mixed with the air in the swirl chamber 8 , and the charge of fuel and air is ignited, and burned in the chamber 8 , and as a result, it expands in volume. The expanded gases pass into the combustion chamber 9 through the main nozzle hole 11 . The fresh charge expands and rises as it goes away from the main nozzle hole 11 in the triangular recess 21 . The fuel-content in the fresh charge mixes with air in the combustion chamber 9 , and the mixture is ignited and burned.
The sub-nozzle holes 12 will be described:
In FIGS. 1A to 1 D, particularly in FIGS. 1B and 1D , the sub-nozzle holes 12 are provided in pair through a base wall 10 of the mouthpiece 7 . Each of the sub-nozzle holes 12 is away from the main nozzle hole 11 such that they are symmetrically positioned about the central axis 13 of the main nozzle hole 11 or about its extension 14 , depending upon the shape of the main nozzle hole 11 .
FIGS. 1A , 1 B, and 1 D show a hypothetical sphere 15 about a center 7 c which is the center of the open end 7 b ( an upper circle ) of the recess 7 a. The radius of the open end 7 b ( an upper circle ) is supposed to be 100%, and that of the sphere 15 to be 50%. Each of the sub-nozzle holes 12 is positioned such that its central axis 12 a- 12 b passes through the sphere 15 , or in the drawing, through an interior area of the sphere 15 .
Preferably, the radius of the sphere 15 is 70%; more preferably, 60%, and most preferably, 50%. In FIGS. 1A , 1 B, and 1 D the innermost, middle, and outermost sphere 15 are drawn in correspondence to 50%, 60%, and 70%, respectively. It has been demonstrated that this range of angular positioning of the sub-nozzle holes 12 enables a secondary air to gather at the center of the swirl chamber 8 , thereby making the most of the air ejected through the sub-nozzle holes 12 and causing effective swirls in the swirl chamber 8 .
FIG. 1A shows, as a preferred embodiment, that the center 12 c of the upper open end of each sub-nozzle hole 12 overlaps the sphere 15 having a radius of 50% when the mouthpiece 7 is seen from just above, thereby enabling the central axis 12 a- 12 b of each sub-nozzle hole 12 to pass through the center of the swirl chamber 8 . In this case, the radius is preferably 70%, more preferably 60%, and most preferably 50% of that (100%) of the open end ( upper circle ) of the top-open recess 7 b.
In FIGS. 1 A B and 1 D, a hypothetical reference line 16 extends just upwards. The position of each hole 12 is determined in relation to this hypothetical reference line 16 ; that is, each sub-nozzle hole 12 is positioned such that its central axis 12 a- 12 b coincides with the reference line 16 in every direction as viewed in FIGS. 1A to 1 D.
In this way the sub-nozzle holes 12 are positioned at various angles for the reference line 16 (FIGS. 1 B and 1 D). If it is positioned at a relatively small angle to the reference line 16 , the sub-nozzle hole 12 can be short in length, thereby reducing frictional resistance to the flow of a secondary air passing through the sub-nozzle hole. In FIG. 1B where the cross-section of the mouthpiece 7 is viewed from the side, and the two sub-nozzle holes 12 appear to be in alignment. In the case where the mouthpiece 7 is viewed from a side, as shown in FIG. 1B , the central axis 12 a- 12 b of the sub-nozzle hole 12 is preferably inclined at 30° or less to the reference line 16 , which will be referred to as “first angle”. In FIG. 1D where the cross-section of the mouthpiece 7 is viewed from the back, and the sub-nozzle holes 12 appear to be arranged side by side. When the main nozzle hole 11 is positioned at a rearward side portion of the mouthpiece 7 and the mouthpiece 7 is viewed from a rear of the mouthpiece 7 , the central axis 12 a- 12 b of the sub- nozzle hole 12 is preferably inclined at 15° or less, which will be referred to as “second angle”. In another preferred embodiment the first angle is 15° or less, and the second angle is 8° or less; more preferably, 8° or less to 4° or less, and most preferably, 4° or less to 2° or less.
In the embodiment illustrated in FIGS. 1B and 1C the first angle is 30° and the second angle is 15° each angular relation being indicated by chain lines.
The size of each sub-nozzle hole 12 is determined as follows:
It has been demonstrated that when the main nozzle hole 11 has an open end having an effective area is supposed to be 100%, the total area of the open ends of the two sub-nozzle holes should be in the range of 3% to 15%; preferably, 4 to 10%; more preferably, 6 to 10%, and most preferably, 7 to 9%. In short, the range of 3 to 15%, or preferably, of 5 to 15% is effective to reduce the production of NOx and fumes evenly.
The main nozzle hole 11 is constructed as follows:
Referring to FIGS. 2A to 2 D, the main nozzle hole 11 includes a main groove 17 and a pair of side grooves 18 communicatively continuous to the main groove 17 through banks (not numbered). In FIG. 2A , each side groove 18 is formed such that its central axis 18 a is slightly behind the central axis 17 a of the main groove 17 . Each side groove 18 is also arranged that its angle of elevation is smaller than 45° of the axis 17 a.
As best shown in FIG. 1A , each of the side grooves 18 gradually but slightly becomes narrower in width toward the depth of the main nozzle hole 11 while the main groove 17 remains the same along its full length. The side grooves are positioned such that the distance between them diminishes toward their forward ends. Each of the side grooves has a progressively diminishing cross-sectional area toward its forward end. When the mouthpiece is seen from just above, each of the side grooves is arranged at a position retreated from an upper opening of every sub-nozzle hole in parallel to a center axis of the main nozzle hole and immediately rearwards thereof.
Referring FIGS. 4 and 5 , the major advantage of the first embodiment is that environmental contaminants such as NOx and fumes are reduced in the exhaust gases, which will be demonstrated, on condition that the applied load is the same:
From FIG. 4 , it will be understood that the first embodiment has less nitrogen oxides (NOx) than a contrasted example (1) that has neither sub-nozzle holes 12 nor the side grooves 18 . It will be appreciated that the sub-nozzle holes 12 and the side grooves 18 are effective to reduce NOx content.
FIG. 5 shows that the first embodiment has less NOx and less fumes than contrasted examples 1 and 2, wherein the contrasted example 2 has sub-nozzle holes corresponding to the sub-nozzle holes 12 but no grooves corresponding to the side grooves 18 . The comparison between the contrasted examples 1 and 2 shows that the addition of the secondary air sub-nozzle holes 12 are conducive to the reduction of NOx and fumes. Likewise, the comparison between the first embodiment and the contrasted example 2 shows that the side grooves 18 are conducive to the reduction of NOx and fumes.
The efficiency of reducing exhaust gases depends upon the area of the open end of the sub-nozzle hole 12 . Referring to FIGS. 6A to 6 C, each horizontal co-ordinate is the percentage of the total minimum area of the open ends of the sub-nozzle holes 12 to the area of the open end of the main nozzle hole 11 . The vertical co-ordinate of FIG. 6A indicates variations in the amount of NOx; in FIG. 6B the vertical co-ordinate indicates variations in the amount of fumes, and in FIG. 6C the vertical co-ordinate indicates variations in the total amount of NOx and fumes. Each coefficient of variation is calculated, as a reference value, based upon the amount of NOx and fumes produced in the combustion chamber having no sub-nozzle holes 12 . Let the reference value be α, and the amount of variation be β. Then, the coefficient of variation will be (β−α)/α.
As shown in FIG. 6C , the absolute value of the total reduction rate is maximized when the area of the open end of the sub-nozzle holes 12 is 7.7%. Let the absolute value of the reduction rate at this stage be 100%. It has been demonstrated that to increase the rate of reduction of exhaust gases up to 98%, the total area of the open ends of the sub-nozzle hole 12 must be in the range of 7 to 9%, and if it exceeds 95%, the total area can be in the range of 6 to 10%. If it exceeds 60%, the total area can be in the range of 3 to 15%. Among these ranges, when it exceeds 70%, and both NOx and fumes effectively decrease, the total area is in the range of 4 to 10%. As a result, it will be concluded that the total area of the open ends of the sub-nozzle holes preferably in the range of 3 to 15%; more preferably, 4 to 10%, further preferably, 6 to 10%, and most preferably, 7 to 9%.
Referring to FIGS. 7 , 8 and 9 , a second embodiment, a third embodiment and a fourth embodiment will be described, respectively:
In the second embodiment shown in FIG. 7 the total area of the open ends of the sub-nozzle holes 12 is 8% of the area (100%) of the open end of the main nozzle hole 11 , wherein each sub-nozzle hole has an open end having the same area. This embodiment reduces the production of NOx or fumes or both, as clearly demonstrated by comparison with the contrasted examples 1 and 2.
In the third embodiment shown in FIG. 8 the pair of sub-nozzle holes 12 are inclined forwardly and upwardly toward the swirl chamber 8 or, in other words, slightly converged toward the swirl chamber 8 from the combustion chamber 9 in contrast to the first and second embodiments where they extend upright between the combustion chamber 9 and the swirl chamber 8 . In FIG. 8B the angle of incline is 30° and in FIG. 8D , the angle of incline is 15° toward each other.
In the fourth embodiment shown in FIGS. 9A to 9 D, the pair of sub-nozzle holes 12 are inclined rearwardly and upwardly toward the swirl chamber 8 , as best shown in FIG. 9B , and, as shown in FIG. 9D , are inclined outwardly or, in other words, slightly diverged toward the swirl chamber 8 from the combustion chamber 9 . In FIG. 9B the angle of incline is 30° and in FIG. 9D , the angle of incline is 15° toward each other. | A swirl chamber used in association with a combustion chamber for diesel engines, includes a pair of sub-nozzle holes on the opposite sides of a main nozzle hole to supply a secondary air into the swirl chamber, the sub-nozzle holes being positioned such that the secondary air ejected therethrough is fully utilized for the combustion in the swirl chamber, thereby securing the complete combustion and the reduction of environmental contaminants such as NOx and fumes. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention is directed toward novel high molecular weight and high purity mPEG alcohol compositions as well as a process for obtaining said compositions by removing PEG diols from the M-PEG alcohol.
[0003] 2. Description of the Prior Art
[0004] The therapeutic efficacy of bioactive molecules can be improved by conjugating them with poly(ethylene glycol)(PEG). The PEG is often a linear poly(ethylene glycol) with one hydroxyl end group capped with a methyl group and the other hydroxyl group activated for conjugation. An activated mPEG is made from mPEG alcohol, which in turn is typically made by initiating anionic polymerization of ethylene oxide with methanol or its equivalent. If there is any water in the polymerization, it forms a linear PEG with hydroxyl groups on both ends. Since the PEG diol undergoes the same activation and conjugation chemistry as mPEG alcohol, it's presence in the mPEG alcohol is undesirable.
[0005] The amount of PEG diol can be reduced by decreasing the amount of water in the polymerization reactor. U.S. Pat. No. 6,455,639, discloses the production of M-PEG alcohol by polymerization of EO under very dry conditions with molecular weights up to 20,861. Obtaining these very low levels of water requires great effort.
[0006] Alternatively, the PEG diol can be converted to its unreactive dimethyl ether. This is performed by initiating polymerization of EO with benzyl alcohol, permethylating all the hydroxyl groups (both on the benzyl PEG and PEG diol), and then removing the benzyl group to give mPEG alcohol and dimethyl PEG (U.S. Pat. No. 6,448,369). The permethylation of the PEG diol requires two additional chemistry steps, and the concentration of the desired mPEG alcohol is reduced by the presence of the dimethyl PEG.
[0007] In addition to the processes described above, a variety of purification techniques for removal of excess diol have been described in the literature. Snow (Snow U.S. Pat. No. 5,298,410, 1994) converted all the hydroxyl groups to dimethoxytrityl ethers, separated the ditrityl PEG from the methyl trityl PEG by reverse phase chromatography, and then removed the trityl group from the methyl trityl PEG to give mPEG. Lapienis (Lapienis and Penczek, J. Bioactive Compatible Polymers, 16, 206 (2001)) used ultrafiltration to purify 2K mPEG, although analysis indicated that little if any PEG was removed. Kazanskii (Kazanskii et al, Polymer Science Ser. A, 42, 585 (2000)) also used ultrafiltration to remove impurities. Kokufuta (Kokufuta et al, Polymer, 24, 1031 (1983)) describes the narrowing of the molecular weight distribution of PEG by complexing it with polyacrylic acid (PAA).
[0008] All prior art purifications cited above use mPEG alcohol with a molecular weight of 5 kDaltons or less. The longevity of bioactive molecules attached to PEG increases with the molecular weight of the PEG. Therefore, it is desirable to use activated mPEG alcohols with molecular weights of at least 10 kdaltons.
SUMMARY OF THE INVENTION
[0009] The invention is directed toward novel high molecular weight and high purity mPEG alcohol compositions as well as a process for obtaining said compositions by using separation techniques to remove PEG diols from the mPEG.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0010] The invention comprises a monomethoxy poly(ethyleneglycol) of at least 95% chemical purity by weight, having a polydispersity value of less than 1.1 and having a defined molecular weight of from 10,000 Daltons to about 60,000 Daltons. Preferably, the monomethoxy poly(ethyleneglycol) of the invention has a polydispersity value of less than 1.05. The invention further comprises a process for obtaining a monomethoxy poly(ethyleneglycol) of at least 95% chemical purity by weight, having a polydispersity value of less than 1.1 and having a defined molecular weight of at least 10,000 Daltons and up to around 60,000 Daltons. The process comprises a first step of providing an impure monomethoxy poly(ethyleneglycol) characterized as a monomethoxy poly(ethyleneglycol) having one or more impurities including poly(ethyleneglycol) [hereinafter “PEG diol”] and low molecular weight organic and inorganic molecules. The impure monomethoxy poly(ethyleneglycol) can be obtained according to well-known polymerization techniques as described in “Poly(Ethylene Oxide)” (F. E. Bailey, Jr. and J. V. Koleske, Academic Press, New York, 1976).
[0011] The impure monomethoxy poly(ethyleneglycol) is directly purified by means of one or more separation techniques such as, but not limited to, polymeric adsorption/desorption, ultrafiltration, chromatography, precipitation or combinations of one or more of the above. The separated PEG diol and low molecular weight organic or inorganic molecules are then removed from the purified monomethoxy poly(ethyleneglycol). The PEG diol may be either of higher or of lower molecular weight than the purified monomethoxy poly(ethyleneglycol) thereby obtained.
[0012] In one embodiment of the invention, the separation technique comprises polymeric adsorption/desorption. The polymeric adsorption/desorption preferably comprises treatment of the impure mPEG alcohol with a polymer containing repeating pendant functional groups capable of hydrogen bonding with the ether oxygen atoms of mPEG alcohol and/or PEG diol, in the presence of a protic solvent. Preferably, the pendant functional groups are selected from the group consisting of CO 2 H, SO 3 H, PO 3 H 2 , NH, NH 2 , OH and SH. Preferably, the polymer is a polyacid. More preferably, the polymer is a poly(carboxylic acid). Most preferably, the polymer is a crosslinked poly(carboxylic acid) resin. Preferably, the protic solvent is selected from the group comprising water, a C 1-3 alcohol or a mixture thereof. More preferably, the protic solvent is water.
[0013] In a second embodiment of the invention. The separation technique comprises ultrafiltration. Ultrafiltration comprises contacting an impure mPEG alcohol solution with a membrane of the appropriate pore size as to allow materials of lower molecular weight to pass through the membrane and be removed.
[0014] The separation technique of chromatography comprises placing the polymer on one end of a column packed with an active support, passing a suitable solvent through the column, and collecting fractions at the other end of the column. The various components of the impure alcohol are separated on the column and collected in separate fractions.
[0015] Analysis of the mPEG polymer for PEG diol content is determined by critical condition HPLC analysis (Gorshkov; J. Chrom. 523, 91 (1990); Kazanskii et al, Polymer Science Ser. A, 42, 585 (2000); Lapienis and Penczek, J. Bioactive Biocompat Polymers, 16, 206 (2001). Critical condition chromatography is useful in this application for analytical separation of the mPEG from PEG diol as the retention time of the polymer is independent of molecular weight, and is only a function of polymer end groups. Specifically in this case, the mPEG and PEG diol polymers are derivatized with 3,5-dinitrobenzoyl chloride and separated at the critical point on a reversed phase analytical column with UV detection.
[0016] The separation technique of precipitation comprises the successive precipitation of polymer from a solution by addition of a miscible nonsolvent, by controlled cooling, or by controlled evaporation of solvent. The polymer molecules with higher molecular weight precipitate first.
[0017] In a preferred embodiment of the invention, the process further includes the step of isolating the pure monomethoxy poly(ethyleneglycol) composition from aqueous solution by an isolation technique selected from the group consisting of spray drying, addition of a non-solvent, extraction into a good solvent followed by addition of a non-solvent and evaporation of solvent under vacuum. The more preferred isolation technique comprises spray drying. The step of spray drying comprises spraying a solution of polymer into a chamber to form droplets, the solvent of which is evaporated in a flow of hot air to give a dry powder.
Examples
Example 1
Ultrafiltration
[0018] Removal of Low Molecular Weight Polymer from 30K mPEG
[0019] A 3.8 kg sample of crude mPEG (Mp 31,491, 5.0 mol % diol) was dissolved in about 75 kg of DI water and loaded to the ultrafiltration feed tank. An Osmonics 2.5 m 2 10K MWCO membrane (model #PW2540F1080) was installed. The recirculation pump was turned on at 28% output. The retentate and permeate back pressure valves were adjusted to achieve a retentate flowrate of 15 lpm with a 30 psi transmembrane pressure. The tank volume was initially concentrated down to about 40 liters, at which time DI water was continuously added in order to maintain a constant tank volume. A total of 303 kg of permeate was collected at an average rate of about 0.4 lpm. GPC analysis of a composite sample indicated the permeate contained 0.7 kg of mPEG. The GPC profile of the permeate was noticeably skewed to the lower molecular weight material. The retentate fraction in the feed tank was further concentrated to about 33 liters and then drained through a 0.2 micron polypropylene polish filter. The final 32.9 kg retentate sample contained 7.6% mPEG by GPC (2.5 kg mPEG). DI water was loaded to the feed tank and recirculated for about 15 minutes to rinse the membrane and piping. GPC analysis indicated the 36.3 kg rinse sample contained an additional 0.6 kg of mPEG. The mPEG in the final retentate sample was isolated using a spray dryer. The diol concentration in the final isolated product was 2.7 mol %.
Example 2
Polyacrylic Acid (PAA)
[0020] Removal of High Molecular Component at Ambient Temperature from 20K mPEG
[0021] Crude 20 kDa mPEG was dissolved in DI water to make a 1.49 wt % solution of mPEG. 317.3 g of this solution were added to a 1-L Erlenmeyer flask fitted with a mechanical stirrer. While stirring, a total of 21 g of Dowex MAC-3 PAA ion exchange resin (containing 48 wt % water) were added. The reaction was stirred at 25° C. for 42 hours. The resin was filtered. GPC analysis of the corresponding filtrate indicated that the high molecular weight component was reduced from 8.6 to 0.3 area %.
[0022] Removal of High Molecular Component at Higher Temperature from 20K mPEG
[0023] Crude 20 kDa mPEG was dissolved in DI water to make a 1.19 wt % solution of mPEG. 571.2 g of this solution were added to a 1-L round bottom flask fitted with a water recirculation bath, mechanical stirrer, condenser, and N 2 purge. While stirring, 22.4 g of Dowex MAC-3 PAA ion exchange resin (containing ˜50 wt % water) and 0.083 g of hydroquinone were added. The reaction was stirred at 63° C. for 4.3 hours. The resin was filtered. GPC analysis of the corresponding filtrate indicated that the high molecular weight component was reduced from 9.2 to 0.6 area %.
[0024] Removal of High and Low Molecular Components from 20K mPEG
[0025] 8017.1 g of 0.725 % aqueous mPeg were added to a 12 litter round bottom flask equipped with a mechanical stirrer, condenser, temperature controller, and N 2 purge. While stirring, 93 g of Dowex MAC-3 PAA (contain ˜50% water) and 1.4 g of hydroquinone were added. The reaction was stirred at 56° C. for 39 hours. The resin containing the high molecular PEG component was separated by filtration and discarded. 7900 g of filtrate containing 31 g of mPEG were collected and GPC analysis showed the high molecular weight component was reduced from 4.6 to 0.2 area %.
[0026] The filtrate was added back to the reactor along with 91 g of fresh PAA (enough to complex greater than 75% of the mPEG). The reaction mixture was stirred at 61° C. for 32 hours. The PAA resin containing the mPEG was collected by filtration and the filtrate (7872 g) was discarded. 115 g of the PAA resin wetcake (containing mPEG) were washed with deionized water and added back to the reactor along with 237 g of 30% aqueous tetrahydrofuran (THF). The mixture was stirred at 25° C. for 20 hours. The PAA resin, from which the mPEG had now been removed, was separated from the mPEG solution by filtration and discarded. GPC analysis of the filtrate showed the low molecular weight component was reduced from 4.0 to 0.7%. THF was removed from the filtrate and 14.8 g mPEG was isolated by extracting the filtrate with chloroform.
Example 3
Spray Drying
[0027] A Buchi B-191 Mini Spray dryer was set up with the following operating parameters: nitrogen flow was 700 L/h, inlet temperature was 95° C., vacuum aspirator was 50% of the maximum speed, and DI water was fed at 15% of the maximum rate. After the system was equilibrated for 30 minutes, the outlet temperature was 36° C. A 951-g aqueous solution containing 3.0 wt % of mPEG (28.5 g) was loaded at 15% of the maximum rate. Over the course of the 3 hour and 10 minute addition, the inlet temperature was adjusted to 97, then 99° C. The outlet temperature ranged from 36 to 38° C. A total of 9.5 g of mPEG was collected as a fluffy white powder from the cyclone. The mPEG contained 0.31 wt % water by Karl Fisher titration.
Example 4
PAA, Ultrafiltration, and Spray Drying
[0028] A sample of M-PEG (Mp 28164, 3.6 mol % PEG diol) was treated with PAA as described above to provide 15.2-kg of an aqueous solution containing 92.7 g of polymer. The solution was subjected to ultrafiltration using an Osmonics 10K MWCO polyethersulfone membrane as described above to provide a 3.2-kg aqueous solution containing 67.7 g of polymer. A portion of the aqueous solution was spray dried as described above to provide 9.1 g of mPEG polymer (Mp 29178) containing 1.3 mol % of PEG diol. | The invention is directed toward novel high molecular weight and high purity mPEG alcohol compositions as well as a process for obtaining said compositions by removing PEG diols from the mPEG alcohol after polymerization is complete. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This disclosure generally involves a method to prepare a nanosized-structure film and its application, especially the method to prepare a nanosized-structure film of multi-phobic effects and its application.
2. Description of the Related Art
Currently, there are many varieties and preparation methods of nanosized film materials and the preparation methods include colloid suspension chemical deposit method, self-assembly method, surface improvement method and electrochemical deposit method and with these methods many types of nanosized-structure functional films are prepared, such as nanosized-semiconductor film, nanosized porous film, nanosized optic film, nanosized magnetic film and nanosized tribological film. With the available technology, nanosized structure film is generally prepared from particles and liner. From the above functions of nanosized-structure films, yet no nanosized-structure film of multi-phobic effects and its preparation methods are claimed. This type of film utilizes the phobic effects to make any substances contacting a substrate (liner) to be fast released or dispersed from the substrate and thus prevent them from adhering to the substrate.
There are many decomposing, hydrophobic and oleophobic materials (i.e., the concept of single-phobic and dual-phobic), and their products are hydrophobic and oleophobic and thus they are water-proof and oil-proof. In the available technology the action merely repels water or oil is called single-phobic and the action repels both water and oil called dual-phobic. We define these materials as phobic-effect materials.
Currently, the phobic-effect materials generally consist of many chemical materials, which combine with the substrate through chemical reaction or chemical bonds and thus change the chemical and physical properties of the substrate. The representative phobic-effect materials include Teflon, N-(t-butyl) acryamide, ethyl-tetradecyl acrylate, vinyl laurate, halogen-bearing monomer, and N-fluoro styrene. Another way to render the substrate water-proof and oil-proof is to add wrapping materials of hydrophobic or oleophobic group (functional group) to the substrate, which are generally super-fine powder or liquid. However, the available technology tend to have the following demerits:
I. The available nanosized-structure films have no multi-phobic effects and they are generally optic film, magnetic film, semiconductor film, conducting film and tribological film.
II. The “phobic-effects” materials in the available technology have merely a single function of water-proof, oil-proof, bacteria-proof, or electromagnetic-proof and they are generally not phobic to several substances.
III. The chemical compositions of the available technology mainly consist of organic substances or wrapping material. The materials have unstable performances and poor durability, and some of them even contain contaminating components and fail to meet ecological requirements.
IV. In the available technology of the single-phobic materials, some powdered materials are used. However, because of their relatively large particle size (generally above 1000 nm) they are not easy to disperse in liquid to form a colloid. When added to the medium, they merely generate unobvious effects and even impair product's luster. In addition, the functional groups on the powder are absorbed onto the powder surface through physical means, therefore, the bonds between the functional groups and the powder are not strong and will be weakened with lapse of time and increase in temperature, thus impairing the functions of the materials and products.
BRIEF SUMMARY OF THE INVENTION
In certain embodiments, a nanosized-structure film material of multi-phobic effects and its application are described. This material keeps the performances of both the substrate and product stable and has multi-functions of being hydrophobic, oleophobic, dust-proof, bacteria-proof and aging-proof.
More specifically, a new type of film and concept of function are proposed, i.e., nanosized structure “multi-phobic effects” film and its preparation. As used herein, the term “multi-phobic effects” means that functionally the nanosized film is able to catalyze, decompose, repel and disperse 3 or more substances, including water, oil, organic foreign matter, inorganic dust, bacteria, light, electricity and magnetism. On the other hand, the single-phobic or dual-phobic materials in the background technology belong to “element-phobic material”.
A new method to prepare nanosized-structure film and its application are also described herein, in which the primary nanosized particle and filming substance are combined with the substrate under given conditions to form stable nanosized-structure compounded film.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
In the drawings, the sizes and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the shapes of various elements and angles are not drawn to scale, and some of these elements are arbitrarily enlarged and positioned to improve drawing legibility. Further, the particular shapes of the elements as drawn, are not intended to convey any information regarding the actual shape of the particular elements, and have been solely selected for ease of recognition in the drawing.
FIG. 1 is a schematic diagram of an embodiment illustrating a substrate coated with a nanosized film of multi-phobic effects.
DETAILED DESCRIPTION OF THE INVENTION
As noted above, a method to prepare multi-phobic effects nanosized-structure film and its application are described herein. It features nanosized material comprising: nanosized bacteria-proof material, nanosized catalysts, nanosized interfacial material, nanosized surface energy-consuming materials and nanosized decomposing materials. The particle size of above materials is below 100 nm, and the above nanosized materials are modified with fluorocarbon surfactants and kept continuous with fluorocarbon filming substances. The thickness of the film is below 500 nm and the film structure may be divided into discontinuous phase and continuous phase.
In the embodiment illustrated in FIG. 1 , a plurality of three types of nanosized particles 10 , 20 and 30 , also referred herein as “nanoparticles”, are randomly distributed in a filming substance 2 to form a nanosized film 4 . The nanosized film 4 is coated or otherwise integrated on a substrate 1 through penetration, absorption and chemical bonds. More specifically, nanoparticles 10 , 20 and 30 represent at least three types of materials and collectively provide multi-phobic effects. Each type of the nanoparticles 10 , 20 and 30 is surfaced modified by at least one of a corresponding type of fluorocarbon surfactant, 12 , 22 and 32 , respectively.
In particular, a method to prepare multi-phobic effects nanosized-structure film and its application are described as follows:
I. Selection of Raw Materials:
(I) Selection of Nanosized Materials:
a. Nanosized bacteria-proof material: silica carrier-based (SiO 2-X ) metal ion bacteria-proof material, at proportion of 8%-12%. Brand: SS 1 , DS 1 and SP 1 .
b. Nanosized catalysts: nanosized titanium oxide (TiO 2 ). Brand: DJ 3 , DJ 3-S .
c. Nanosized decomposing material: zinc oxide (ZnO). Brand: MN6Z.
d. Nanosized interfacial material: Alumina (AlO 3 ). Brand: NR-3Al.
e. Nanosized surface energy-consuming material: (TiO 2 ). Brand: RX-05.
(II) Selection of Modifying Aids:
Nanosized material modifying aids may be selected from different types of fluorocarbon surfactants depending on type of the above-mentioned nanosized materials, including:
Nanosized bacteria-proof material: tetrafluoro-isophthalonitrile surfactant.
Nanosized catalysts: fluorocarbon silane surfactant.
Nanosized decomposing material: perfluoro fluoro-silicone polymeric surfactant.
Nanosized interfacial material and surface energy-consuming material: 5% fluoroalkyl surfactant.
(III) Selection of Filming Substance:
The filming substance may be selected from fluorocarbon filming active material. An example of a filming substance includes, but is not limited to: perfluoro alkyl sulfuryl alkyl acrylate.
(IV) Selection of Dispersing Media of Nanosized Material:
The dispersing medium for modifying nanosized material may be an aromatic hydrocarbon. Typically, aliphatics-substituted aromatics, or their derivatives, for example, toluene and xylene are used as dispersing medium.
In preparation of dispersing medium for nanosized-structure film, on the other hand, deionized water is used.
II. Preparation Methods:
(I) Process for Modifying Nanosized Material:
The nanosized material used can be modified as follows: Disperse the above-mentioned nanosized powdered materials in dispersing medium xylene, add fluorocarbon surfactants to the dispersing medium at proportion of nanosized material: fluorocarbon surfactants ranging from about 1:0.005-1:0.01to make hydroxyl groups on surface of nanosized material completely react with fluorocarbon surfactants, remove dispersing medium, and obtain nanosized modified powdered materials through drying.
(II) Process of Preparation of Nanosized Compounded Material:
1. Compounding proportion for nanosized compounded powder: Thoroughly mix the above-mentioned nanosized materials in an agitator at proportion of:
a:b:c:d:e=20-30%:15-25%:20-30%:15-25%:15-20%
(III) Preparation of Nanosized Filming Paste:
1. Selection of Raw Materials
f. Nanosized material: the above-mentioned nanosized modified compounded material, 0.1-2%.
g. Fluorocarbon filming substance: perfluoro alkyl sulfuryl alkyl acrylate 2-4%.
h. Functional aid: polyoxyethylennated alcohol, 0.05%-0.1%.
i. Dispersing medium: deionized water, 85-95%.
In one embodiment, the compounding proportion is:
f:g:h:i=2%:4%:0.1%:93.9%
2. Process of Preparation of Filming Paste:
Prepare raw materials at the above-mentioned proportion, add functional aid to dispersing medium (deionized water) at 50-70° C. and constant agitation to make the functional aid evenly dissolved in dispersing medium, slowly add the modified nanosized compounded material to the above solution under agitation at 120-160 rpm for 20-30 minutes, make indirect dispersion with emulsifying machine for 10-20 minutes to make nanosized material evenly dispersed in the liquid phase, slowly add fluorocarbon filming substance to the dispersed nanosized liquid phase and slowly and evenly mix the solution.
(IV) Process of Preparation of Nanosized-structure Film:
Thoroughly clean the substrate to be filmed, apply the filming paste onto the substrate through spray or dipping, dry the pasted substrate at 120-180° C. for 0.5-1 minute and control the thickness of nanosized-structure film through adjusting paste concentration, production link or filming-pressure.
Advantageously, the nanosized film prepared with the above-mentioned technical scheme has different functions, filming process, used materials and microstructure, and offers the following merits:
I. The nanosized-structure film in this disclosure is in-situ combined with the substrate and is inseparable from the substrate.
II. The nanosized material used for the nanosized-structure film is a multi-functional compounded material and through surface modifying, the film is able to repel and disperse water, oil, organic foreign matter, inorganic dust, bacteria, light, electricity and magnetism and overcome the demerits of single-phobic or dual-phobic materials in the existing technology.
III. The modifying aids for nanosized materials are mainly fluorocarbon surfactants, and a slight addition will remarkably reduce surface tension of a liquid (e.g., lower that of water from 73 mn/m to 8 mn/m).
IV. Due to the unique geometric dimension and electric negativity of fluorine atom, the modified nanosized material is highly thermal-stable, and highly resistant to very strong acid, alkali and oxidant.
V. Finally, fluorocarbon is used as the filming material to remarkably reduce film thickness, keep the chemical and physical properties and color of the original substrate, and greatly improve transparency and permeability.
From the above analysis, the multi-phobic effect nanosized-structure film prepared according to the method described herein eliminates the demerits of the background technology.
The following non-limiting examples describe specific processes and compositions for preparing films of multi-phobic effects.
EXAMPLE 1
Modified Nanosized Material
Add 30 g fluorocarbon surfactants (trade name: FN-80) to 200 ml toluene solvent, after complete dissolution, slowly add 200 g nanosized silica powder into above surfactant-containing solvent, then thoroughly mix the solution to make them completely react, remove toluene, dry the reaction product in oven at 120° C. and finally disperse the dried product with air-flow crusher to obtain white powdered nanosized modified material.
EXAMPLE 2
Add 100 g nanosized titanium oxide to 800 mL xylene, evenly mix them at room temperature, slowly add 8 g fluorocarbon surfactant to the mixed solution, under ultrasonic dispersion while adding, after addition continue ultrasonic agitation for 10 minutes to make them completely react, remove xylene from the solution to obtain the reaction product of titanium oxide and fluorocarbon surfactant, dry the reaction product in oven under 150° C., and finally disperse the dried product with air-flow crusher to obtain white powdered modified nanosized titanium oxide.
With the above method other modified powdered nanosized materials can be obtained such as modified nanosized zinc oxide and nanosized alumina.
EXAMPLE 3
Preparation of Nanosized Compounded Powder
Compound nanosized modified powders prepared in example 1 and 2 at the following proportion:
1. Selection of Raw Materials:
a. Nanosized bacteria-proof material: silica of size 30 nm; b. Nanosized catalysts: titanium oxide of size 20 nm; c. Nanosized decomposing material: zinc oxide of size 60 nm; d. Nanosized interfacial material: alumina of size 50 nm. e. Nanosized surface energy-consuming material: titanium oxide of radium 10 nm.
2. Mixing Proportion:
a:b:c:d:e=23%:20%:22%:20%:15%
3. Technological Process:
Add the above modified nanosized materials as per the above sequence and proportion to mixer, thoroughly mix them at 150 rpm for 30 minutes and then take them out.
EXAMPLE 4
Preparation of Nanosized Filming Paste
1. Selection of Raw Materials
f. Nanosized modified mixture 0.5%; g. Fluorocarbon filming substance perfluoro alkyl sulfuryl alkyl acrylate 5%; h. Functional aid: fatty alcohol polyoxyethylene ether, 0.1%; i. Dispersing medium: deionized water having conductivity below 0.1.
2. Mixing Proportion:
f:g:h:i=0.5%:5%:0.1%:94.4%
3. Preparation of Filming Paste:
Prepare raw materials at the above proportion, add functional aid to dispersing medium (deionized water), accelerate agitation to make functional aid evenly dissolved in dispersing medium, slowly add modified nanosized mixture of Example 3 to the above solution, mix the solution with agitator under 160 rpm for 30 minutes, evenly disperse the nanosized material in liquid phase for 10 minutes with emulsifying machine, disperse fluorocarbon filming substance and slowly add it to the dispersed nanosized liquid phase under slow agitation till even dissolving of the filming substance.
EXAMPLE 5
Preparation of Fabric Nanosized-Structure Film
Wash the to-be-filmed fibrous fabric, evenly spray the above paste on surface of the fabric twice, dry the paste-sprayed fabric in oven at 150° C. for 1 minute and obtain nanosized-structure filmed fabric.
EXAMPLE 6
Preparation of Nanosized-Structure Film on Glass Product Surface
Clean the glass product surface, adhere the nanosized filming paste onto glass product surface, take out the pasted glass product, dry it in oven at 120° C. for 5 minutes, take out it again and let it cool down.
EXAMPLE 7
Preparation of Nanosized-Structure Film on Vehicle Body Surface
Clean the vehicle body surface, evenly spray the nanosized filming paste onto vehicle body surface, and heat the said body in oven at 80° C. for 10 minutes.
EXAMPLE 8
Preparation of Nanosized-Structure Film on Brick, Stone and Wood Wall Surface
Clean the brick, stone and wood wall surface, evenly spray the above paste onto wall surface, and contact an infrared heating source (100° C.) with the wall surface for 5 minutes to obtain nanosized filmed wall surface.
All of the above U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet, are incorporated herein by reference, in their entirety.
From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims. | A method to prepare multi-phobic effects nanosized-structure film and its application are described, which features nanosized silica, titanium oxide and zinc oxide compounded materials of previous size 3-100 nm are in-situ combined with substrate through fluorocarbon surfactants and perfluoro alkyl filming substance under specific conditions to form a nanosized-structure film. The reaction between fluorocarbon surfactants and hydroxyl groups on surfaces of nanosized particles renders the modified nanosized particle and nanosized film having extremely high chemical stability, resistance, and the capacity to repel and disperse water, oil, bacteria, organic dust, gas, electricity, magnetism and light (i.e., multi-phobic effects). This technology may be widely used in surface modification of fabric, chemical fiber, cotton, wool, glass product, brick-stone concrete and wood wall. | 2 |
FIELD OF THE INVENTION
The present invention relates to a soil characterization apparatus and method for using the same, and more particularly, to a characterization apparatus, and a method to employ such apparatus, which is adapted for use with cone penetrometer rods and other direct push emplacement technologies, for subsurface contaminant plume and landfill measurement testing.
BACKGROUND OF THE INVENTION
The permeability of soil is defined as the soil's conductivity to fluid flow. The permeability of soil to fluid flow depends upon the magnitude of soil gas and groundwater flow when subjected to particular natural and/or unnatural pressure gradients. Pressure gradients exist due to natural effects such as hydraulic gradients (in the case of groundwater) and barometrically imposed gradients (in the case of soil gas). Unnatural (forced) gradients can be imposed by soil vapor extraction, air sparging, active venting, pump and treat, and other remediation processes requiring the movement of fluids through the soil.
The design of any of these processes requires a knowledge of the flow characteristics of the soil to be remediated. The soil's permeability is the largest variable, which can vary by orders of magnitude in any given hydrological and/or geological environment. Therefore, knowledge of soil gas permeability is required to design soil vapor extraction systems and understand, in general, the movement of gas in the soil. Similarly, knowledge of saturated hydraulic conductivity (or, the soil's permeability to liquid flow) is required to predict movement of groundwater in saturated soils.
Soil permeability has historically been measured either in laboratories on a very small scale or in the field on a very large scale. Laboratory measurements rarely agree with data collected in the field due to the difficulty of obtaining truly undisturbed soil samples. Further, laboratory test results are usually at least an order of magnitude lower than actual field results.
Because of the high cost and time constraints of obtaining field measurements, it is oftentimes beneficial to first obtain soil permeability measurements in a laboratory setting. The flow of fluid and the travel of contaminant plumes in subsurface soils are capable of being mathematically modeled if the soil's permeability is known. Frequently, however, it is difficult to readily determine the accuracy of the soil's permeability for several reasons. For example, soil is heterogeneous in varying degrees, usually depending upon the type of soil in the surrounding environment, the depth of the soil and the physical scale of interest. Additionally, it is known that soil permeability can vary between two to three orders of magnitude at most soil remediation sites. Consequently, the ability to obtain quality predictive modeling results in the laboratory, whether to estimate soil gas travel or to design alternative remediation systems, is heavily dependant upon the accuracy of the predicted soil permeability and the surrounding environment.
In the field, soil gas permeability measurements are obtained either through total borehole flow or isolated packer (also referred to as a "straddle packer") measurement techniques. Total borehole flow measurements are obtained from open or screened boreholes, where gas or liquid is injected into or extracted from the borehole well. In particular, permeability measurements (gas or liquid) are typically obtained from boreholes using a cylindrical flow model and geometry. Long screened or uncased sections of the borehole are subjected to unnatural (e.g., forced) pressure gradients and the resultant flow into or out of the well is subsequently measured in order to obtain the soil permeability. For one-dimensional radial symmetric (cylindrical) flow geometries such as these, the test region is relatively long and a radius of influence is either measured (or can be predicted) to determine the surrounding soil's permeability. The inherent weakness with this approach, however, is that it results in providing only an average permeability over the test region, and cannot delineate stratigraphic features within any particular test region or depth.
A disadvantage to the current method of obtaining permeability measurements in the field is that it is impossible to translate unmodified open borehole measurement techniques to penetrometer measurement because of size limitations and the penetrometer's compaction of the soil.
Various direct push measurement techniques exist, with perhaps the use of penetrometer rods (or, "penetrometers") being the most common. The direct push technologies using penetration rods include an elongated rod which is pushed into the ground to penetrate the ground and subsurface depths. Generally, each penetrometer rod is a continuously cylindrical steel tube having a hollow interior channel. At one end of some penetrometer rods (e.g., the end which is embedded in the ground) is placed a cone-shaped tip (seen generally in FIG. 3). These types of penetrometers are referred to as "cone penetrometers." If desired, the penetrometer rod can travel deeply into the subsurface by the assistance of a hydraulic ram or other conventional means.
Use of a penetrometer rod to obtain permeability data is inherently less intrusive than drilling boreholes. Penetrometers provide vastly more data in the same amount of time as do drilled holes, at a much lower cost and risk to the operators of penetrometer. Penetrometers, and other direct push techniques (such as the ResonantSonic system) are rapidly advancing as hole formation and soil characterization tools because they are capable of emplacement in difficult media. Therefore, conducting permeability measurements with direct push techniques, instead of in drilled boreholes, retains all of the advantages of penetrometer emplacements.
Conventional cone penetrometer systems are already outfitted for soil gas and liquid sampling, geophysical measurements, in-situ chemical analysis, temperature logging, pore pressure measurements, and direction indicating capabilities. For example, permeability measurements are conducted with cone penetrometer emplacements by observing the dissipation of pore pressure after the soil has been compacted by the rod emplacement. The ability to obtain pore pressure data is included in a conventional geophysical measurement package located at the tip of the cone penetrometer. A disadvantage to this type of testing, however, is that this type of measurement requires a knowledge of the soil type to infer the soil's permeability, which in many cases is difficult to predict. Furthermore, this type of testing cannot be conducted in high permeability zones because the pressure dissipation in the soil is too rapid.
Conversely, conducting cone penetrometer testing using a spherical flow model, as described in the present invention, can provide detailed soil permeability data as a function of the depth at which the measurement is taken. This is because the testing region is relatively small (measured in fractions of a meter versus meters for the cylindrical model), allowing discrete measurements at high resolution in boreholes.
Therefore, it is an object of the present invention to provide a measurement method which allows quantitative in-situ determination of gas and saturated liquid permeability with a modified cone penetrometer and other direct push techniques.
It is also an object of the present invention to provide a soil permeability measurement method which substantially reduces field costs, is rapidly emplaced, generates minimal secondary waste generation and reduces worker exposure to chemical and radiological hazards.
It is a further object of this invention to obtain steady state measurements of air and saturated liquid permeability at various subsurface depths during a direct push technique which is unaffected by the compaction of the soil caused by the penetrometer.
It is also an object of the present invention to utilize a spherical flow geometry measurement method, in conjunction with direct push techniques, to obtain information relating to soil permeability as a function of depth.
It is another object of the present invention to provide a in situ measurement apparatus adapted to employ a spherical flow model to obtain information relating to soil permeability as a function of depth, without substantial disturbance of subsurface soil.
SUMMARY OF THE INVENTION
A method for discrete soil gas and saturated liquid permeability measurements with direct push emplacement systems (such as a cone penetrometer). A modified direct push emplacement system having at least one injection port and at least one monitoring port is first engaged to penetrate the soil to a predetermined depth. Gas or liquid is then injected into the soil at a predetermined location on the penetrometer rod. Next, a differential pressure response is recorded from at least two measurement ports, which are at a known distance from the injection port (on the same penetrometer rod). This pressure response data allows calculation of the soil permeability directly by using a one-dimensional, spherical, steady state, porous flow model to measure the effective permeability of the soil, without substantial disturbance of the surrounding soil.
The present invention is well-suited to direct push applications for a number of reasons. First, because the present method's environmental sphere of influence is small and discrete (e.g., in or around the direct push system), the amount of fluid injected into (or extracted from) the test region is small. This is important because of the limited space inside the direct push system for fluid pressure transfer lines and monitoring lines. Second, the present method does not require a long time period to reach a steady state condition. This provides for obtaining multiple measurements in relatively short periods of time while providing high spatial resolution. Third, the present invention's methodology is designed such that the compaction of soil adjacent to the rod, caused by the direct push system, has minimal impact on the inferred soil permeability.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial cross sectional view of the present invention inserted into the subsurface;
FIG. 2 is a graphical representation of the fluid flow field when the present invention is employed;
FIG. 3 is a partial cross sectional view of the present invention;
FIG. 4 is a partial cross sectional view of the present invention as tested in the laboratory;
FIG. 5 is a graphical illustration of the gas pressure distribution adjacent to the test set up according to FIG. 4;
FIG. 6 is a graphical illustration of the pressure profiles along and perpendicular to the axis of a penetrometer rod as set up according to the configuration of FIG. 4;
FIG. 7 is an alternate embodiment of the present invention;
FIG. 8 is a side view of an alternate embodiment of the present invention;
FIG. 9 is a detailed view of a portion of the embodiment shown in FIG. 8;
FIG. 10 graphically illustrates the portable vehicle employed with the invention of FIG. 8;
FIG. 11 is another side view of the invention illustrated in FIG. 8, depicting additional components disclosed; and
FIG. 12 illustrates the one dimensional steady state, spherical porous flow model disclosed in the present invention.
DESCRIPTION OF THE INVENTION
As seen in FIG. 1, the present invention includes a hollow-channeled penetrometer rod 10 having a cone 11 at one end (as seen in FIG. 3), at least one or more injection ports 13 and a plurality of measurement ports 15 along the length of rod 10, both ports integrally formed into or upon rod 10. In one embodiment, cone 11 on rod 10 is preferably of similar diameter as the diameter of rod 10. Each pressure port is in gas-flow communication with pressure sensor 23 through the hollow interior channel 17 of rod 10 and each port is formed at a predetermined radial distance away from any other port. In the preferred embodiment, each injection port 13 is at least equal to one half of the diameter of rod 10 to induce constant soil pressure in the adjacent environment.
Preferably, there is only a single injection port 13, and each injection port 13 is screened or slotted, is designed to allow air or fluid injection or extraction through the screened or slotted section, and is designed to assist the surrounding soil to reach equilibrium in a short time when subjected to fluid pressure. Further, measurement ports 15 would be fabricated at at least two locations above the extraction zone. These ports would be filtered penetrations into the probe which would allow pressure communication up to the ground surface. Thus, each injection port 13 is adapted to engage one end of a conventional injection line 21a through which either gas or liquid can flow. The exterior length of injection lines 21a is then placed within the interior channel 17 of rod 10, with the injection line's second end terminating at pressure source 21 above the surface to supply gas or liquid to injection port 13.
The plurality of measurement ports 15 are adapted to retain one or more sensor means 15a (as seen in FIG. 1) which are electrically or hydraulically connected via signal communication means 23a within the rod's interior channel 17 to one or more predetermined sensing devices 23 located above the surface. Such sensing devices, for example, can include a wire, a conventional manometer, or a computer, all adapted to electrically communicate with the sensor means and being capable of receiving soil permeability measurement data.
To obtain soil permeability measurements, rod 10 is inserted (or, pushed) into the ground by any conventional means. The interior channel 17 of rod 10 will contain the necessary injection lines and electrical signal wires which connect to the injection ports and measurement ports, respectively. As rod 10 is inserted into the subsurface, and because cone 11 is of substantially similar diameter as the diameter of rod 10, the rod's 10 exterior surface 25 will have a tight fit above and below the injection ports and measurement ports. Then, a fluid, such as a liquid or a gas, is injected through injection line 21a (or extracted from the injection line) to an injection port 13 on the penetrometer rod 10. This injection (or extraction) will result in a spherical flow field as the fluid moves outward from the rod, and is required to induce an equilibrium in the surrounding soil for accuracy. In most circumstances, soil equilibrium is achieved in less than five minutes. Subsequently, the flow field will become essentially spherical even if the soil adjacent to the rod is of a much lower permeability (due to soil compaction). As represented in FIG. 2, the injection or extraction source is represented as a spherical volume with radius r o . Fluid is added (or removed) from the zone at a known rate. The medium has a permeability, k, which is assumed homogeneous.
Eventually, equilibrium will be reached, which means that for any given injection rate, the radial pressure profile along the axis of penetrometer rod 10 is identical to that which would occur if rod 10 (and compacted soil) did not exist. Once equilibrium has been reached, a permeability measurement is obtained from the sensing means 23a and communicated to sensing devices 23. Measurement of the pressure gradient at some distance from the injection port produces adequate information to infer the permeability accurately. Subsequently, rod 10 can be further pushed into the subsurface 30 for additional or repetitive testing. In light of the foregoing, those of skill in the art will realize that additional measurements can be obtained through sensing means 23a, such as atmospheric pressure, temperature, and fluid flow rate.
When the exterior surface of rod 10 is in tight fitting relationship with the immediate soil, the permeability test data results may be heavily influenced by the compacted soil annulus formed as penetrometer 10 is forced into the adjacent soil. A compacted layer as thin as half a centimeter would likely result in artificially low inferred permeability due to the high pressure gradient caused in this region by the reduction of soil porosity. As such, the pressure field will eventually become spherical as the distance from the injection zone increases. The details of the extraction source geometry can be ignored if radial pressure measurements are taken at a distance from the source. The resulting radial pressure profile then allows the definition of r o as the distance from the extraction source to the first pressure measurement location (as seen in FIG. 2).
FIGS. 4 and 6 exemplify a laboratory test simulation where the steady state radial symmetric AIRFLOW code was used to model the soil gas response. In this example, a 4.4 cm-diameter penetrometer with a 32 cm-high screened injection zone is emplaced in soil with a uniform permeability of 5 Darcies. The resulting contour plot (as seen in FIG. 5) indicates that at a short distance from the extraction source, the isobars become very spherical. The cylindrical geometry eventually results in a spherical flow field. At slightly less than 0.5 of a meter from the injection source, the pressure profile along the axis of the penetrometer equals the profile radially outward from the penetrometer rod. Additionally, as seen in FIG. 12, a one dimensional steady state flow model is employed to generate the desired information. In particular, R is the universal gas constant, P o is the pressure inside the sphere, P is the pressure outside of the sphere, r o is the radius within the sphere, r is the radius outside of the sphere, ρ is the density, μ is the viscosity of the injection fluid, T is the temperature, and m is the fluid's flow rate. Those of skill in the art will realize that with obtaining the proper data, this model can be employed in a data acquisition unit and analysis device without undue experimentation to obtain the desired results.
In geographic areas composed of highly saturated conditions, an alternative embodiment of the present invention is adapted to obtain permeability measurements using inflatable packers inside of the rod. In this fashion, and as seen in FIG. 7, miniature packers 35 are secured along the penetrometer rod at preselected intervals. Each packer 35 is capable of being inflated, so that when rod 10 is at the desired subsurface depth, all the packers are inflated to provide a stable support structure for the rod and also provide a plurality of enclosed testing regions 50. Each testing region 50 includes a port 15 which allows fluid pressure communication with the soil. The packer 35 allows injection of air into the soil while the pressure measurements accurately monitor soil gas pressure. This design has the advantage of leaving the penetrometer rod open for other uses. In operation, each testing region 50 can either be an injection port 13 or a measurement port 15.
An alternate embodiment of the present invention is shown in FIGS. 8-11. In this embodiment, a direct push emplacement system is mounted on a truck for portability. The system includes rod 51 similar to rod 10 above, and preferably, is a conventional two inch diameter by approximately three foot long length. The internal channel of rod 51 includes tubing 67 which can transport fluid from the earthen surface to the point of desired injection (defined as the injection zone). Gas (such as air) or liquid (such as water) is injected into the soil through a screened or filtered portion 53 located at the bottom of rod 51. Rod 51 includes a plurality of precision pressure sensors 55 (preferably five) embedded in rod 51 to measure the pore fluid pressure in the soil at specific distances from the injection zone. The electrical signals generated from sensors 55 are then transmitted to the earthen surface to a data acquisition unit 57 (such as a computer) by conventional means, such as electrical wire or cable 59. The fluid injection zone pressure and temperature inside rod 51 are measured with sensors 61. Like sensors 55, the information generated by sensors 61 is transmitted to the earthen surface through conventional means, such as cable 59.
As seen in FIGS. 10-11, the alternate embodiment is employed by stationing truck 63 over a preselected measurement location 65. Penetrometer rod is pushed to the desired measurement depth 65. Gas or fluid is then pumped into the injection tubing 67 from box 69 containing the gas and fluid pumps. For example, a reservoir of clean water 71 (or similar fluid) can be used to provide the injection fluid. Preferably, pump box 69 also includes meters (not shown) that measure the gas and fluid flow rates. Signals from these flow meters, and pressure sensors 55, 61 in the rod section, can then be transmitted to data acquisition unit and analysis device 57 through cable 59. Data acquisition unit and analysis device 57 calculates the permeability using mathematical models described above. The advantage of the present invention is that it provides higher quality data and will work over long distances (e.g., hundreds of feet). In contrast, the previous methods are difficult to employ using long pressure measurement tubes.
The present invention offers several advantages over conventional soil permeability techniques. For example, the present invention provides an absolute measure of soil permeability and is adapted to measure a wide range of soil permeability conditions in both saturated and unsaturated soil. The invention also does not require permanently occupying the inner core of the penetrometer and is designed to pass other electrical signals and tubes running to measurements at the penetrometer's tip. Finally, the cost savings of this method, when compared to drilled borehole measurements, are significant. Borehole formation costs range from tens to hundreds of thousands of dollars for a typical well, depending on the type of drilling operation, nature of contamination, depth of well, and the geologic media. Additionally, a typical drilling operation for a 100 ft. well requires two to five days. In contrast, the method of the present invention can be accomplished in one day with a full suite of measurements. In both gas and liquid permeability measurements, the measurement time per station is less than five minutes, so 20 to 40 measurements could be accomplished during one push, in one day. This provides a great deal of detail in permeability distribution.
Whereas the drawings and accompanying description have shown and described the preferred embodiment of the present invention, it should be apparent to those skilled in the art that various changes may be made in the form of the invention without affecting the scope thereof. | An apparatus and method for discrete soil gas and saturated liquid permeability measurements with direct push emplacement systems (such as a cone penetrometer rod). A modified direct push emplacement system having at least one injection port and at least two measurement ports is first engaged to penetrate the soil to a predetermined depth. Gas or liquid is then injected into the soil at a predetermined location on the penetrometer rod. Next, a pressure response is recorded from each measurement port, which is at a known distance from the injection port (on the same penetrometer rod). This differential pressure response data allows calculation of the soil permeability directly by using a one-dimensional, spherical, steady state, porous flow model to measure the effective permeability of the soil, without substantial disturbance of the surrounding soil. The present invention minimizes false indications of reduced permeability as a result of soil compaction during the penetrometer emplacement. | 6 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part Application of prior pending application U.S. Ser. No. 001,648, filed Jan. 9, 1987, now abandoned entitled "AN ISOLATION, STERILIZATION AND MAXIMUM OBSERVATION TENT", the teachings of which are incorporated by reference.
BACKGROUND OF THE INVENTION
This invention relates to a device for the isolation of a body or a part of the body in a sterile environment and more particularly, this invention relates to device for the isolation of a corpse during and after the performance of an autopsy to prevent possible infection and contamination of medical personnel.
In many medical procedures, it is desirable to isolate the body of the patient. Isolation is important to protect a patient from microorganisms in the general environment. Patient isolation is also extremely important in the treatment of a patient suffering from a highly infectious disease for the safety of attending medical personnel.
In the case of an autopsy, isolation of the corpse is extremely desirable to protect the doctors and attendants during the autopsy, especially when a lethal and possibly contagious disease was the cause of death. Isolation could be important when AIDS, Jacob Creutzfeld disease, Hepatitis or Tuberculosis, for example, was the cause of death.
Furthermore, once the autopsy has been performed, infection of personnel can occur during the clean-up process. Blood spills, pieces of tissue and other fluids and matter associated with the autopsy can soil personnel clothing and the equipment and floors in the autopsy suite creating a risk of infection to personnel. Indeed, even the air surrounding the corpse may be infected with air-born microorganisms creating a health risk. Thus, personnel performing the autopsy are at risk during the autopsy and furthermore, personnel involved with the clean-up of the autopsy suite and the transport of items used during the autopsy are also in danger of infection. It has become apparent that equipment and procedures should be utilized during the autopsy that minimize the risk of spread of possible infection from the corpse. Therefore, it would be desirable to have an isolation apparatus surrounding the corpse to contain body matter, prevent microorganisms from becoming air-born and to provide a convenient and safe method to remove the matter during the clean-up after the autopsy. It would also be desirable to have a means for disinfecting the air within such an isolation apparatus after the autopsy has been performed and before the isolation is broken by removing the corpse from the isolation device.
Various devices have been suggested to isolate a body and to contain body matter while procedures are performed on the body. For example, U.S. Pat. No. 4,224,936 to Cox discloses a transit isolator that facilitates the transfer of a patient from one unit to another. The isolator comprises two sets of frames, one of which has suspended from it, an isolator in the form of a flexible film envelope and a basal structure to support the patient and all horizontal members. Essentially, this device is for the protection of a hypersensitive patient and would not contain matter secreted from the body of the patient. Moreover, it would not allow attending personnel to work on the patient without removing him from isolation.
U.S. Pat. No. 4,367,728 to Mutke discloses an isolation apparatus comprising a flexible envelope divided into a plurality of sealed sections having air or gas supplied so that optimum inflation condition of the sack is always achieved. It should be noted that this device is optimally a device for treatment of live patients. Furthermore, it requires air or gas systems for the good of the patient and to maintain isolation compartments.
Prior to the present invention there simply was no apparatus which could effectively protect medical personnel from contamination during an autopsy, provide a means for safe disposal of contaminated materials utilized during the autopsy and also disinfect the air after the autopsy had been performed.
Accordingly, it is a principal object of the present invention to provide a simple and inexpensive apparatus to isolate a corpse or part of the corpse from its surroundings during a medical procedure such as an autopsy so that medical personnel performing the medical procedure are protected from infectious matter.
A further object of the present invention is to provide an isolation apparatus which will reduce the risk of infection to physicians and other attending personnel during and after a medical procedure.
Another object of the present invention is to provide an isolation apparatus which is collapsible into its own self-contained disposable bag thereby allowing the apparatus and any corpse matter resulting from the medical procedure which had been performed to be disposed of with minimum risk of spread of infection.
Yet another object of the present invention is to provide an isolation apparatus having means for disinfecting the air within the isolation apparatus after the medical procedure is completed an before the isolation seal is broken.
Still another object of the present invention is to provide an isolation apparatus having means for collection and containment of body matter and fluids secreted during a medical procedure.
SUMMARY OF THE INVENTION
The present invention provides a simple and inexpensive isolation apparatus which will isolate a corpse during a medical procedure such as an autopsy and contain matter spilling from the corpse during the procedure that may be infectious.
Doctors and attendants performing the medical procedure are then protected both during and after the procedure and through the clean-up and sterilization process.
The isolation, sterilization and maximum observation (ISMO) tent of the present invention comprises a frame and a one-piece form fitted translucent sheet supported by the frame. The ISMO tent of the present invention may be sized to fit a whole corpse on which the medical procedure will be performed. In a preferred embodiment, the bottom edges of the tent have a continuous elastic band secured thereto, similar to the elastic band on a shower cap, so that when the tent is placed on an operating table the elastic band draws the edges of the tent under the table so that any liquids that might otherwise spill and reach the floor of the operating room are trapped by the tent itself. In a preferred embodiment, there is an adsorbent material, treated with disinfectant, in close proximity to the bottom edge of the tent to adsorb any fluids that may be trapped by the pocket formed by the elasticized edges of the tent.
Important features of the present invention are those features designed to reduce or eliminate the risk of spread of contagious diseases. Thus, the tent itself completely encloses the corpse and has portholes which are sealably released when a hand is pushed through to allow an attendant to perform the autopsy. The tent will have one or more slits or openings releasably sealed with flaps that can be opened for removal of organs and/or insertion of instruments. The tent is provided with an extended rear panel comprising a disposable bag, sealable with a flap, so that at the end of the procedure, the entire tent and even the frame may be collapsed into the bag and sealed with the flap for easy and sanitary disposal of the device. In addition, along the top of the side walls of the tent, one or more atomizers are placed for decontaminating sprayers which can be activated after the medical procedure to decontaminate all air-born, ambient particles and gases before the isolation seal is broken and the corpse is removed.
The invention will be more clearly understood from a reading of the following detailed description of the invention taken together with the drawing in which like reference numbers refer to like members throughout the various figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a full corpse isolation, sterilization and maximum observation tent in accordance with the present invention;
FIG. 2 is a left side view of an isolation, sterilization and maximum observation tent in accordance with the present invention;
FIG. 3 is a perspective view of a half corpse isolation, sterilization and maximum observation tent in accordance with the present invention;
FIG. 4 is a schematic diagram of the edge seal and fluid collector of the isolation, sterilization and maximum observation tent and its attachment to the support or table on which the corpse rests in accordance with the present invention; and
FIG. 5 is a perspective view of an isolation, sterilization and maximum observation tent showing its attachment to the table or support in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
At the outset, the invention is described in its broadest overall aspects with a more detailed description following.
The isolation, sterilization and maximum observation (ISMO) tent of the present invention is comprised of a frame and a one piece form fitted sheet supported by the frame. The frame for the ISMO tent is comprised of various interlocking parts. The frame may be formed of any material capable of supporting the tent. Suitable materials are aluminum, steel or even hard plastic. If it is desired that the frame be disposable along with the tent, an inexpensive material may be used to form the frame and the frame will be provided with hinges or telescopic fittings or any suitable means so that the frame can fold into itself for compact disposal. Should it be desirable to have a permanent frame, the frame can attach to either the floor, the ceiling, or the table.
The ISMO tent of the present invention may be made for a procedure involving the whole body or merely a portion of the body. A whole body tent is useful when an autopsy is being performed. A half body tent would be used when the medical personnel are examining only a portion of the body, for example the head when a patient has died from a brain disorder or from a head injury. The structure of the ISMO tent of either embodiment is similar, except that the whole body ISMO tent will be sized and structured to surround the whole corpse.
FIG. 1 illustrates the whole body ISMO tent. A preferred embodiment of the frame is shown in FIG. 1, the frame comprises vertical posts 14 that can be attached to either the table 22, or the floor, or even the ceiling. The frame may consist of horizontal members 16 depending on the materials used to make the frame. The frame has hooks 30 that coincide with the location of the loops 21 on the tent. There is an elastic band 48 attached o three sides near the bottom edge of the tent that pulls the bottom edge of the tent under the table thereby sealing the tent against the edges of the table. An adsorbent material that may be treated with a disinfectant aids in sealing the tent to the edge of the table and adsorbs any fluids that may collect along the edge of the table.
FIG. 3 illustrates the half body ISMO tent. The frame for the half body ISMO tent consists of vertical members 42 and can have horizontal members 45 as well. The body or half body rests on table pads 12 which are supported by the table 22. Frame supports 13 are provided to hold the frame 21 on the table pads 12. In either embodiment, a headrest 17 may be provided for the corpse.
The tent 20 for both the whole and half corpse ISMO is a one piece, clear, flexible sheet that is supported by the frame. The tent may hang from the frame by plastic attachment loops 21 which are attached to the tent 20. The flexible tent may be formed from any material which will allow viewing through the tent. Therefore, any transparent air-tight material, such as a flexible plastic or polyurethane would be suitable in the present invention. The whole corpse and half corpse ISMO tents of the present invention are substantially identical except for their lengths.
The ISMO tent of the present invention is designed with numerous features which will maintain isolation during the autopsy and prevent the spread of infection during and after autopsy. The tent sides are designed to be long enough to extend past the bottom of the table as the tent is supported by the frame. FIG. 4 shows the sides of the tent securely held in place by the elasticized edge 48 of the tent to the underside of the table. As shown in FIG. 3, the sides of the tent drape over the edges of the table 22 on which the corpse rests, then are tucked under the edge, in the direction of the arrows in this figure, and are held in place under the table by an elastic edge 48 pulling tight.
FIG. 4 illustrates the liquid seal and securing system of the tent sides. In FIG. 4, it can be seen that when the ISMO tent drapes over the sides of the table, the liquid seal 49, which may consist of an adsorbent material, is pulled tightly against the side of the table 22. The table 22 may support table pad 12 on which the corpse rests.
FIG. 5 further illustrates the liquid sealing mechanism for securing the tent to the table. The adsorbent material 50 is located all along the outer edge of the tent. Below this adsorbent strip 50 is the elastic band 48 attached to three sides of the tent 20. An adhesive strip 51 is located on the front edge of table 20 and seals the front edge of the tent. The other three sides of the tent are pulled tightly against the table. Any liquid on or near the edges of the table is thereby adsorbed and disinfected by the adsorbent strip 50.
FIG. 2, which shows a left side view from behind the head of the patient within either the half corpse or whole corpse ISMO tent, illustrates other safety features. The tent 20 has aperture type expanding portholes 24 for the doctor's and technician's access to the corpse. Aperture type is meant that the portholes are sealed prior to the insertion of a hand or object therethrough. Upon their insertion, the opening of the porthole 24 unfolds to permit the object to go through, but will still maintain a seal to prevent microorganisms from inside the tent from escaping into the environment. The portholes may additionally be provided with gloves for the medical personnel. The portholes may be placed anywhere along the tent that it is envisioned access to the corpse will be required. These portholes 24 enable access to the corpse while maintaining isolation between the attendants and the corpse.
The tent may have one or more small sealable portholes or pockets 25 sealable with a flap 26 communicating with the interior of the tent to allow insertion of instruments into the tent 20. One embodiment of this pocket 25 and flap 26 is shown more clearly in FIG. 2 in a place it can be positioned. The pocket 25 can be positioned anywhere on the tent 20 for the convenience of the attendants. For example, the rear of the tent 20 may also have a pocket 25 and a sealable flap 26 that is able to be opened and closed, for example by a velcro seal, for the removal of organs. This configuration is shown in FIG. 3. The flap 26 can be sealed with means such as velcro strips and will maintain the isolation in the ISMO tent until it is released and an object pushed through into or out of the pocket 25.
The features which will maximize prevention of the spread of infection are the atomizers 31 and the disposal bag 28. Along the top of the sides of the tent and in communication with the interior of the tent are one or more atomizers 31 and the disposal bag 28. Along the top of the sides of the tent and in communication with the interior of the tent are one or more atomizers 31 for decontaminating sprays which can be activated after the procedure to decontaminate all air-born, ambient particles or gases inside the tent before removal of the corpse 15 from the tent 20. Conventional atomizers, such as those used in the funeral industry may be incorporated into the present invention.
The disposal bag 28 is located at the rear of the tent. The tent 20 has an extended rear pocket which forms a disposal bag 28 that is attached to the rear of the table. At the end of the procedure, the entire tent may be collapsed into the bag 28 for easy and sanitary disposal of the tent and the corpse matter contained therein. The disposal bag is then sealed by suitable means. This allows for completely sanitary disposal of the fluids and remains incorporated therein.
It is understood that the form of the isolation, sterilization and maximum observation tent shown and described herein is a preferred embodiment and that the device may be constructed of various other materials without departing from the spirit and scope of the invention. The invention is defined as all embodiments within the scope of the claims which follow. | An isolation, sterilization and maximum observation (ISMO) tent for the isolation of a corpse during a medical procedure and to contain matter spilling from the corpse. The ISMO tent includes a frame and a form fitted translucent sheet supported by the frame, and will preferably have a continuous elastic band secured to the bottom edge of the sheet and an absorbent material, treated with disinfectant, in close proximity thereto to prevent spillage of infectious material. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to the field of treating substrates with a treating medium. More particularly, the present invention is directed to an apparatus and method for turbulently applying a treating medium onto a substrate to more effectively apply the medium onto and throughout the substrate in a more controlled manner.
2. Discussion of Related Art
Man-made fibers are generally formed by extruding a spinning solution through a spinnerette to form a tow made up of a number of individual filaments, usually at least about 3,000 filaments, or more. In the production of these fibers, it is usually necessary to subject the tow of fibers to some kind of treatment with a liquid treating medium at some state in the manufacture of these fibers.
For example, the tow of fibers is generally washed with water for the purpose of removing a spinning solvent. Alternatively, a lubricating agent, a sizing agent, or a finishing agent may be applied to the fibers during their manufacture and as a last step before being wound onto a creel in order to improve their handleability and processability during and after manufacture. So too, the treating medium may comprise a dye to color the fibers, a washing medium to remove excess dye after a dyeing operation, or a chemical agent to modify the physical and/or chemical properties and behavior of the fibers.
Similarly, a woven cloth may also have need for being treated with a liquid treating medium during its manufacture at a textile mill. Thus, the steps of washing, dyeing, adding a finishing agent, an antistatic agent, ect. may also be applied to such a cloth as well. As used herein, the term "substrate" is meant to include one or more fibers in the form of a tow, or in a form where the fibers have been worked to form a cloth, such as, a woven or knitted fabric etc.
Various means have been employed in the prior art for applying a treating medium onto a substrate such as a tow of fibers or a fabric.
In one system, the substrate merely enters and leaves a bath containing the treating medium. For example, in some wet spinning operations, a freshly spun synthetic fiber tow is passed through one or more baths of hot water to remove the residual solvent from the filaments. A major disadvantage of this process is that it is inefficient. This inefficiency stems from the fact that circulation of the hot water around and through the moving tow is generally poor.
In another system, such as the one described in U.S. Pat. No. 3,791,788, the substrate passes through a confined zone having elaborate deflecting surfaces provided therein as the treating medium is applied. While the confined zone may aid in the effectiveness of applying the treating medium onto the substrate, this system may suffer from the disadvantage that the treating medium is applied in a manner which does not provide a satisfactory degree of agitation of the fibers within the substrate. As a result, all of the surface area of the fibers may not thoroughly be subjected to the effects of the treating medium and, most importantly, not all the fibers will have been separated from one another, i.e, deagglomerated. The treating medium is generally applied by flowing through a channel which is transverse to the direction of substrate travel. As a result, the flow pattern of the treating medium and the manner in which it impinges upon the substrate is such that it may not be effective in getting at the surface of each fiber.
In yet another system, the treating medium is applied by means of spray jets as the substrate passes in close proximity. This system of application is meant to overcome yet another disadvantage associated with each of the first two applicating systems noted above. In particular, one of the primary concerns in the production of synthetic fibers in the form of a tow is the sticking of one fiber to another which results in a decrease in the overall tensile strength of the tow. In contrast to the baths or confined treatment zones discussed above, the application of the treating medium by means of spray jets is generally able to disentangle and unstick any fibers that are joined together, particularly when the treating medium employed is an oiling agent or a finishing agent, due to the direct and forceful impingement of the fibers with the treating medium. However, when the substrate is allowed to simply freely pass past the spray jets, there is no real control as to the amount of impingement upon the fibers. As a result, the fibers usually wind up being stretched, even to the point of breakage. Such stretching and/or breaking of the fibers within a tow will generally undesirably affect its strength characteristics.
SUMMARY OF THE INVENTION
Applicant has discovered a new apparatus for applying a treating medium onto a substrate, particularly a tow of fibers, which apparatus avoids substantially all of the disadvantages and problems noted above with respect to the prior art application systems.
Applicant's apparatus is able to apply the treating medium in a turbulent manner while the substrate is in a confined zone. In this manner, a controlled amount of turbulence can be applied to the substrate such that each individual fiber is completely and uniformly contacted with the treating medium. Moreover, by virtue of the controlled turbulence within a confined treatment zone, the fibers are agitated to such an extent they are deagglomerated without, however, causing excessive stretching or breaking of the fibers. Still further, the apparatus of the present invention, in contrast to some of the more elaborate prior art systems, is simple, economical and is no more than about eight to twelve inches in length.
More specifically, in its most broadest embodiment, the apparatus of the present invention comprises an upper member, a lower member and two side members. The upper and lower members and two side members form a chamber through which the moving substrate and a treating medium pass. The upper member extends upwardly from an upper horizontal plane and the lower member extends downwardly from a lower horizontal plane. The planes are parallelly spaced apart by a distance equal to the height of the two side members. The upper member has at least one cavity extending perpendicular to the upper horizontal plane, one end of which opens into the chamber and the other end of which is adapted to receive a first means for turbulently applying treating medium onto the substrate. The lower member also has at least one cavity extending perpendicular to the lower horizontal plane one end of which opens into the chamber and the other end of which is adapted to receive a second means for turbulently applying treating medium onto the substrate wherein for each cavity present on the upper member, there is a cavity present in the lower member having the same longitudinal axis.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of one embodiment of the turbulent flow liquid application apparatus of the present invention.
FIG. 2 is a cross-sectional view of the apparatus taken along line A--A of FIG. 1 looking at the apparatus in the direction of substrate travel.
FIG. 3 is a cross sectional view of the apparatus taken along line B--B of FIG. 1 looking at the apparatus from the top.
FIG. 4 is a cross-sectional view of the apparatus taken along line C--C of FIG. 1 looking at the side of the apparatus.
DETAILED DESCRIPTION OF THE INVENTION
In order to better understand the construction and use of the apparatus and method for applying a treating medium onto a substrate in accordance with the present invention, it will be described in connection with the treatment of a filamentary tow of synthetic fibers. It is to be understood, however, that various other types of substrates, as that term has been defined herein, such as finished or partly finished fabrics, may also be treated by the apparatus and method herein.
The apparatus and method of the present invention can be utilized to remove excess or unwanted materials or fluids from a tow of fibers or from a finished or partly finished fabric. Alternatively, the present apparatus and method can be utilized to assure complete and uniform penetration of a liquid treating medium such as a dye bath, finishing additives, oiling agents, delustrants, or various other chemicals through a tow of fibers or a fabric. In either manner, the fibers are agitated in a controlled manner such that in addition to effectively applying the treating medium onto the fibers in only a short distance of fiber travel, every filament in the tow is separated from adjacent filaments to deagglomerate the fibers and to help prevent further sticking of the fibers to one another during subsequent processing but in a manner which does not adversely affect the qualities of the fibers.
Referring to the accompanying Figures, wherein like numerals designate the same apparatus element throughout the various views, there is shown a turbulent flow application apparatus generally designated as 10. The application apparatus 10 is comprised of an upper member 12 and a lower member 14 which are held in a parallelly spaced apart relationship by two side plates 16. The side plates 16 are slidably secured to the upper and lower members 12 and 14 by any conventional manner such as by a threaded rod 18 extending through the members 12 and 14 and side plates 16 which is fixed by a locking nut 20. Alternatively, the upper and lower members and the two side plates may be held together by a simple clamping means (not shown).
The space between the upper and lower members 12 and 14 and side plates 16 forms a confined zone through which a substrate such as a tow of fibers 25 passes. The lower face 32 of the upper member 12 forming a horizontal plane and the upper face 34 of the lower member 14 also forming a horizontal plane and the inner faces 36 of side plates 16 define the limits of the confined zone through which the tow 25 passes. The confined zone thus has a width "w" and a height "h" as best seen in FIG. 2.
As can be seen from the drawing, tow 25 is introduced into apparatus 10 in the form of thin flat ribbon of filaments. This arrangement of filaments can generally be obtained by simply allowing a tow to freely pass over a number of rollers and thereby flatten and spread out.
The width "w" of the opening through the confined zone of the apparatus may be slightly greater in width than the flattened tow 25. The turbulent action of the treating medium on the tow causes it to spread in both the horizontal and vertical directions so that it completely and uniformly fills the area available to it within the confined zone of the apparatus.
As noted above, it is desired to have the width of the opening of the confined zone slightly greater than the width of the flattened tow 25. The width "w" can be adjusted by moving side plates 16 towards or away from each other, which plates may be provided with slots 40 extending from the upper face 42 to the lower face 32 of the plates through which rods 18 pass thereby making the plates slidably engaged with members 12 and 14.
The height "h" of the confined zone is defined by the height of the side plates 16. Generally, this height is in the range of between about 1.5 and 15 times the vertical thickness of the substrate being treated before it enters the application apparatus and is about 0.05 to about 1.0 inch.
As can best be seen in FIGS. 2 and 4, each member 12 and 14, respectively, is provided with at least one cavity. For each cavity present in the upper member, there is a corresponding cavity present in the lower member having the same longitudinal axis. The cavities may comprise essentially any shape such as a cylindrical bore or in the shape of a parallelepiped or a prism, etc. In the embodiment shown in the Figures, a cylindrical base is depicted as the cavity contained in each of the upper and lower members. It is to be understood, however, that the apparatus of the present invention is not limited to such a configuration.
Cylindrical bore 50 contained within upper member 12 is positioned perpendicularly to the horizontal plane formed by lower face 32. The lower end 54 of cylindrical bore 50 opens into the confined zone. The upper end 56 is coextensive with upper surface 80 of upper member 12 and is adapted so as to accommodate a turbulent flow applicator means 70 which is secured by securing means 72. Similarly, cylindrical bore 52 is contained within lower member 14 and is positioned perpendicularly to the horizontal plane formed by upper face 34. The upper end 58 of cylindrical bore 52 opens into the confined zone. The lower end 60 is coextensive with lower surface 90 of lower member 14 and is adopted so as to accommodate a turbulent flow applicator means 74 which is secured by securing means 76. Bores 50 and 52 are coaxial with one another having the same longitudinal axis.
Desirably, the diameter of bores 50 and 52 are equal to one another and is substantially the same as width "w" of the confined zone. Suitably, the bore diameter is generally in the range of between about 0.25 to about 2.0 inches. The height "H" of each bore is generally such that the distance between the applicator and the substrate (shown as height H in FIG. 4) is between about 0.125 to about 2.0 inches, and preferably about 0.25 to 1.0 inch so as to provide proper impingement of the substrate with the treating medium to assure good turbulence and penetration.
Applicator means 70 and 74 may be the same or different. Suitable applicators which can effectively apply a treating medium in a controlled turbulent manner and which provide a desirable flow path include spray jets, ultrasonic probes, pulsing jets, vibratory devices and the like. Spray jets are available as nozzles, channels or spray bars. Most preferred are spray jet nozzles having an orifice diameter of between about 0.031 to 0.188 inch. In a preferred embodiment, the spray jets are mounted on a universal joint so as to make them pivotable and thereby be able to adjust the angle of treating medium impingement upon the fibers. The spray pattern emanating from a nozzle may be a hollow cone, a full cone, a solid stream, a square stream, or preferably, a flat spray pattern.
When using an ultrasonic probe, the treating medium liquid is ultrasonically vibrated desirably at 20 Khz whereby the probe transfers the high intensity energy to the moving tow of fibers. A phenomenon known as cavitation produces a shearing on anything that is near the ultrasonic probe tip. The ultrasonic energy imparted to the flowing fluid and substrate promotes agitation, blending, deagglomeration and dispersion.
In operation, the tow 25 advances through the confined zone in the direction indicated by Arrow Z. A treating medium such as water, lubricating oil, sizing agent, dye, etc. is supplied to applicators 70 and 74 via inlet conduits 84.
As the tow passes over and underneath the cylindrical bore openings into the confined zone, the treating medium emanating from the applicators impinges upon the fibers from above and/or below. If only one applicator is used, the flow rate is adjusted to ensure that a turbulent flow is obtained sufficient to not only completely and uniformly contact the overall surface area of the fibers but to moreover effectively agitate and vibrate the fibers as depicted in FIG. 3 so as to cause a deagglomeration action. It has been determined that better turbulence is obtained when using only the lower applicator but that overall properties are enhanced by using both nozzles directed to impinge upon the substrate in the confined zone. Typically, the flow rate of one applicator when used alone would generally be in the range of from about 0.2 to about 2.0 gal/min.
When both applicators are simultaneously used to apply the treating medium, the treating medium leaving applicator 70 contacts and passes through tow 25 and then continues on to deflect in opposing orifice 52 and once again contacts tow 25. Similarly, the treating medium leaving applicator 74 contacts and passes through tow 25 and then continues on to deflect in opposing orifice 50 from where it once again contacts tow 25. A similar effect is obtained when only one applicator is utilized. The action of the treating medium flowing in one direction and then deflecting so that it essentially reverses its direction and flows in the other direction is enough to create the sought after turbulence.
When both applicators are used, the overall action of the treating medium flowing in both directions simultaneously and then deflecting in the opposing orifice where it reverses direction and then joins with the flow of the applicator in that orifice is such that an extremely turbulent zone is created which is very efficient in applying the treating medium onto and throughout the fibers and, moreover, is extremely efficient in deagglomerating the fibers. Despite this extreme turbulence, excessive stretching of the fibers or breaking of the fibers is nevertheless essentially prevented due to the fact that the tow of fibers enters this turbulent zone while contained within the confined treatment zone. When both applicators are used, the flow rate of the treating medium through one applicator is generally also in the range of between about 0.2 to about 2.0 gal/min.
The treating medium leaving apparatus 10 leaves countercurrently as shown by Arrow A in FIG. 3 through the fiber inlet side of the confined zone of the apparatus and cocurrently as shown by Arrow B through the fiber outlet side of the confined zone. Desirably, a collection tank (not shown) is situated immediately beneath the application apparatus to collect the treating medium as it leaves and recycle it to the apparatus.
Preferably, various parts of the application apparatus are made from materials which offer the minimum amount of friction against the fibers so as to reduce the possibility of fiber fraying. Such materials include but are not limited to Teflon, polished chrome platings, glass, ceramics, and the like, and would be most beneficial if used as the material of construction for the upper and lower members 12 and 14 and side plates 16.
It is to be understood that the embodiment disclosed herein is merely illustrative and that this embodiment can be modified or amended and that numerous other embodiments can be contemplated without departing from the spirit and scope of the present invention. | An apparatus is disclosed for continuously applying a treating medium onto a moving substrate in a turbulent manner. The apparatus is provided with a chamber through which the substrate and the treating medium are passed. Both the upper and lower portions of the chamber each have at least one cavity which is perpendicular to the direction of travel of the substrate, wherein the respective cavities of the upper and lower portions are coaxial with one another. Each cavity contains an applicator which is capable of turbulently applying the treating medium onto the substrate. A method of treating a substrate with a treating medium using this apparatus is also disclosed. By means of the apparatus and method disclosed, a substrate can be treated in a more controlled and efficient manner. | 3 |
BACKGROUND OF THE INVENTION
The present invention relates to methods and apparatus for producing an improved insulation and, more particularly, to a method and apparatus to impregnate cellulose fibers with a chemical solution to impart to the cellulose fiber fire and/or pest resistance.
Cellulose fiber thermal insulation generated from hammermilled newspaper has been used as a loose-fill insulation in buildings for more than thirty years. In order to reduce the fire hazard connected with this type material, various dry chemicals have been blended into the milled fibers, most notably, mixtures of powdered borax, such as sodium borate pentahydrate and boric acid. Fortuitously, these borates also give the finished material some measure of pest resistance. To obtain an acceptable flame spread resistance, this process requires a weight ratio of dry chemicals to cellulose fiber of about 1 to 3. Although various other dry chemicals have been utilized for imparting fire resistance, these chemicals usually require higher dose rates and introduce other problems, such as corrosiveness, toxicity, cost, microbial activity and adverse moisture absorption characteristics. A survey of the various chemicals and techniques utilized and representing the state of the art is given by R. W. Anderson of the U.S. Government's Energy Research and Development Administration in a paper entitled "Survey of Cellulose Insulation Materials," dated January 1977, and available through the National Technical Information Service (NTIS). A significant problem cited is the gross separation of the dense chemical particles from the fibers leaving the fibers unprotected, causing excessive dust and waste of chemical.
Until recently, the utilization of borates to chemically treat cellulose fiber materials to provide a thermal insulation has been adequate although wasteful. However, as the cost of domestic energy has burgeoned, the demand for all forms of thermal insulation has increased dramatically. With the advent of increased demand for cellulose fiber insulation, a proportionally increased demand for a supply of borate chemicals also appeared. However, the supply of borate chemicals was found to be somewhat inelastic and severe shortages of borates and, consequently, of properly treated cellulose fiber insulation came into existence accompanied by volatile prices and speculation with existing supplies. It has consequently become apparent that a substitute chemical, as well as a new process for manufacturing cellulose fiber insulation having permanently adequate fire retardant properties, is needed.
The textile industry has long known of the effectiveness of many chemical fire retardant agents which are utilized at much lower proportions to cellulose fiber content than has been practiced by the insulation industry utilizing borates. For example, one method of fireproofing textile fabrics has been to dip the material in a solution of specific concentration leaving a residual chemical intimate with and thoroughly absorbed in the fibers. Such dip and dry techniques are not practical in the cellulose fiber insulation industry because the cellulose fiber particles are very small, loose and not readily subject to such a dipping and drying process. Furthermore, it is not known which chemical agents offer the best combination of properties for both manufacturing and the finished product. Thus, even though the textile industry has fire-proofed textiles by the dipping and drying process, such a technique does not indicate how loose fiber may be impregnated with a wet chemical. Furthermore, the technical grade phosphates utilized in the textile industry are far too expensive for economic utilization in cellulose fiber insulation even at the lower residual treatment concentrations applied to the textiles.
It has been found that agricultural grade phosphates provide adequate fire-retardance, constitute a less expensive chemical than any of the various borates and may be utilized in substantially smaller ratios (see "Ammonium Polyphosphate Liquid Fertilizer As A Fire Retardant For Wood," American Wood-Preserver's Association, 1969, pages 1-12, by Eckner, Stinson and Jordan; and "Fire Suppression & Detection Systems," Glencoe Press 1974, by John L. Bryan.) However, such lower cost agricultural phosphates are difficult to pulverize and do not adapt to the dry blending process with reasonable yield or effectiveness. Furthermore, the more common of the agricultural phosphates (diammonium orthophosphate) has been found unstable in solution, in milling and at elevated temperatures, tending to evolve free ammonia which is an unacceptable nuisance in the manufacturing process. The use of agricultural grade phosphates in conventional wet blending processes can involve a high energy cost for a subsequent drying and is, therefore, impractial as well. The required tolerances within which variations in the proportion of the various constituents may vary cannot be practically achieved in continuous dry blending processes. Unacceptable variations in the proportions are further exacerbated by the fact that there is generally insufficient adhesion of the dry chemical to the fibers to prevent gross separation of the chemical and the cellulose fibers during bagging, shipping and application.
Utilizing the method and process of the invention disclosed herein, the full potential of cellulose fiber insulation may be realized. Not only can sufficient process control tolerances be achieved in practice, but a superior loose fill insulation, particularly applicable in the insulation of existing buildings, is obtained. Furthermore, the present invention generates a fire retardant cellulose fiber insulation which remains intact even in the presence of direct flame impingement and does not melt or contribute to fuel the fire. Because the present invention utilizes a wet impregnation and drying process, the fire retardant impregnation is complete and uniform assuring a uniformity of properties with no material separation. In addition, resistance to vermin and microorganisms is easily obtained by simply mixing into the solution traces of appropriate chemical or biocidal agents with the fire retardant chemical prior to impingement on the cellulose fibers. Corrosion protection can likewise be obtained with the addition of appropriate chemical inhibitors.
The raw materials, including the phosphates and the cellulose fibers, are low cost and widely available in large quantities. Furthermore, the cellulose fibers may be obtained from recycled newsprint and other waste materials which make optimal use, and thus conservation, of natural resources. In addition, the agricultural grade phosphates utilized in the present invention are among the most plentiful bulk chemicals available and, unlike borates, can amount to but a negligible fraction of the total use of such chemicals for agricultural purposes. Another advantage of the method and apparatus in accordance with the present invention is that the materials used are physically and chemically benign achieving the maximum of occupational safety and environmental protection in both the manufacturing and installation process. Furthermore, the finished product has a low content of very fine particles and, thus, a much reduced tendency to make dust. Finally, a principal advantage of the present invention is that the manufacturing plant involvement, know-how, energy and operating costs are less than for other types of insulation processes and the installation skills and equipment required are minimal and well known.
SUMMARY OF THE INVENTION
The present invention comprises a cellulose material treatment system which initially incorporates a pulverizing apparatus for pulverizing cellulose material into a quantity of cellulose fiber. A means for formulating a composite solution of at least one protective chemical agent is provided. A means for uniformly wetting the cellulose fiber with the solution is provided and includes a means for separating the cellulose fibers into individual particles and a means for spraying a mist of the composite solution into the individual particles. A means for drying and then collecting the individual particles to form a quantity of treated cellulose fibers is finally provided.
More particularly, a shredder or hammermill or other similar device initially breaks the cellulose material into relatively coarse particles. The resultant material may then be sorted to take out any metallic materials or heavy particles which may be contained therein. The resultant cellulose material is next air conveyed along ducting by means of a fan positioned to generate a flow of air through the ducting, to a cyclone separator which separates the cellulose material from the flowing air and deposits the cellulose material in a bin. The exhaust air may then be exhausted through a filter to remove fine fibers and dust. The coarse cellulose particles in the paper bin are metered by an adjustable speed screw feeder to a second hammermill for milling the material into fibers, preferably small enough to pass through a 10/64 to 16/64 inch screen. A portion of the exhaust air from the first cyclone separator, which has been heated in the hammermill process, is recycled to the inlet of the second hammermill to aid in the subsequent drying process step. Of course, it will be appreciated that any means for pulverizing the cellulose material to obtain quantities of cellulose fibers having a relatively small size can be utilized in accordance with the present invention.
At the output of the second hammermill, a fan is provided to again air convey the cellulose fibers along a flow path defined by additional ducting to a second cyclone separator. Incorporated as part of the fan at the output of the second hammermill is an injection nozzle to generate fine droplets of a fire retardant chemical solution. This solution is sprayed from the injection nozzle into the small cellulose fibers from the second hammermill as the cellulose fibers are blown past the nozzle so that the fine droplets are intimately contacted with the cellulose fibers and are absorbed therein. Subsequently, most of the moisture is extracted from the fibers by the hot dry air generated by the pulverizing process and utilized in the air conveyance of the fibers. The air is utilized to convey the particles to the second cyclone separator and preferably has a temperature sufficient to produce substantially dry impregnated fibers in a second cyclone separator. The second cyclone separator separates the impregnated cellulose fibers and deposits those fibers in a second bin from which the finished product may be withdrawn and bagged. The exhaust air from the second cyclone separator may also be exhausted through the filter which recovers the small cellulose fibers remaining and exhausts the filtered air and water vapor. The resultant fibers collected in the filter may be returned to the second collection bin utilizing additional ducting and fans.
The chemical solution sprayed by the injection nozzle may be prepared by a batch process or by counterflow percolation of heated liquid upward through a fixed bed of soluble chemical, such as ammonium phosphate. Using the percolation method, the concentration may be regulated by the simple method of thermostatic control of the resultant saturated solution since the concentration of the chemical in such a saturated solution is almost strictly a function of temperature.
In addition to controlling the concentration of chemical in the solution, the amount of such solution which is combined with the cellulose fiber in order to achieve the desired chemical to cellulose ratio may be achieved by slaving a chemical solution pump to the second hammermill in the following manner.
Recognizing first that the current provided to the drive motor of the second hammermill is related to the mass flow rate of cellulose fiber processed by the mill, the current transformer of an adjustable current relay installed in the drive motor line of the second hammermill may be utilized to generate a signal which is proportional to the mass flow rate of the cellulose fiber. This signal may then be utilized to control an adjustable speed drive mechanism equipped with an external signal follower feature. Once the desired ratio between chemical solution and cellulose fiber is defined, the adjustable speed drive may be appropriately calibrated to adjust the pumping rate of the injection pump which draws the saturated solution from a settling tank and forces the solution through the injection nozzle. Thus, once the desired ratio between the chemical solution and paper is set, the adjustable speed drive in conjunction with the adjustable current relay acts to adjust the speed of the injection pump to follow the current level of the second hammermill motor thereby maintaining a ratio between chemical and cellulose fiber within a narrow tolerance over a wide range of cellulose fiber flow rates. This method may also be applied to a process in which only one hammermill is used in a single storage milling operation.
The preferred embodiment of the present invention thus provides control apparatus whereby a constant concentration of chemicals in a solution and a constant ratio between the amount of chemical and cellulose fiber in a finished product may be maintained within narrow tolerances. It is also obvious that, when a screw feeder is used to meter pre-grooved paper to the finish mill, feed speed can be used to provide the proportional control of the injection pump.
Finally, apparatus may be provided in the present invention to combine auxilliary fire retardant or pest retardant chemicals with the saturated solution just prior to its being sprayed through the injection nozzle. Of course, to obtain the proper chemical solution in a batch process, the auxiliary chemicals may be added directly to each batch as it is formulated.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other advantages and features of the present invention will be apparent from the detailed discussion taken below in conjunction with the accompanying drawings wherein like reference characters refer to like parts throughout and in which:
FIGS. 1A and 1B combine to illustrate a plant schematic representative of the apparatus and method of the present invention;
FIG. 2 is a detail showing a preferred embodiment of an injection nozzle;
FIG. 3 is a partial plant schematic illustrating a batch process of obtaining the chemical solution;
FIGS. 4A and 4B represent a block diagram illustrating a cellulose fiber insulation process in accordance with the present invention including various controls, alarms and displays;
FIG. 5 is a graph showing the relationship between paper flow rate, screw displacement, screw speed and motor speed for given finish mill current values in a specific embodiment of the present invention; and
FIG. 6 is a graph showing the relationship between flow and pressure for given pump speeds in a specific embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIGS. 1A and 1B, a cellulose fiber insulation process plant schematic 100 is shown in accordance with the present invention. Initially, paper material 102, which is preferably waste paper such as old newspapers, is loaded onto conveyor belt 108 which feeds the waste paper into a hammermill 112 where the waste paper is pulverized. The hammermill 112 is operative in response to a drive motor 110. The conveyor belt 108 may be powered by an adjustable speed drive motor 106 whose speed may be manually adjusted to provide an optimal feed rate for the waste paper 102. Of course, it will be appreciated that various other means to initially pulverize the waste paper may be provided without departing from the spirit of the present invention. For example, a shredder may be utilized.
The resultant pulverized waste paper from the hammermill 112 is preferably of a size which will pass a 3/4" to 1-1/4" screen. If the waste paper 102 contains heavy or magnetic materials, the pulverized waste paper from the hammermill 112 may be sorted in a sorter (not shown) which may be placed at the output of the hammermill 112.
The coarse particles from the hammermill 112 are next blown into a flow path 115 by a fan 114. The flow path 115 may be defined by any of a number of types of ducting which confines and directs a flowing stream of air. The coarse particles are air conveyed along the flow path 115 to a cyclone separator 116 which separates the coarse particles from the flowing air and causes the exhaust air to pass along a flow path 117.
In the preferred embodiment, the flow path 117 directs the exhaust air from the cyclone separator 116 through a filter apparatus 148 to remove any remaining fine fibers and dust. An auxiliary fan 146 may also be provided in the flow path 117 to provide sufficient exhaust air velocity along the flow path 117.
The coarse particles introduced into the cyclone separator 116 are collected in a paper bin 118 which includes an adjustable speed screw feeder 122 for feeding the coarse paper particles from the bottom of the paper bin 118 to a second hammermill 126. The screw feeder 122 is also provided with an adjustable speed drive motor 120 which may be externally adjusted to vary the rate at which the coarse paper particles are withdrawn from the paper bin 118.
Part of the air from the first cyclone separator 116 flowing along the flow path 117 is channeled along a third flow path 127 in which a damper 129 is placed to regulate the air flow, and then into the hammermill 126 to provide a source of heated air to assist in the drying process after the cellulose fibers are sprayed with the chemical solution. It will be appreciated, of course, that the various hammermill and separator steps result in the generation of heat energy which causes the flowing air in the flow paths 115 and 117 to be heated. Thus, a separate air heater will generally not be necessary.
The final milling, which occurs in the hammermill 126, preferably produces a quantity of paper cellulose fibers small enough to pass through a 10/64" to 16/64" screen. The cellulose fibers from the hammermill 126 are propelled to a fan 130. The fan 130 may, of course, be a part of the hammermill 126. An injection nozzle 132 is provided in the flow path after the hammermill 126 for spraying a chemical solution into the stream of flowing cellulose fibers to wet the cellulose fibers with the chemical solution. In the preferred embodiment, an injection nozzle 132 is provided to spray a very fine mist or fog of the solution and may be of a type shown in FIG. 2.
Referring to FIG. 2, air with suspended cellulose fiber particles flows along the flow path 20 towards the fan or blower 130, after which it is exhausted to the second cyclone separator 138 along the flow path 137. Because the chemical solution may be of a highly viscous nature and may further contain a high fraction of suspended solids, a relatively large and open nozzle 22 is preferable for reliability. Furthermore, the solution flow rates vary over a wide range so that the inlet pressure may be too low to accomplish any degree of hydraulic atomization in certain instances. To overcome these problems and limitations, a high velocity compressed air jet is used to impinge upon the low velocity, laminar liquid stream to produce a highly atomized, high velocity turbulent fan of solution particles which can penetrate and intimately contact the low density turbulent stream of air suspended cellulose fiber particles.
Thus, in FIG. 2, the solution is inserted through a pipe 24 which is attached to a bolted saddle flange 26 fixed to the duct wall of the flow path 20. Also fixed to the bolted saddle flange 26 is a second pipe 28 which conveys compressed air. The pipes 24 and 28 extend through the bolted saddle flange 26 preferably to the center of the flow path 20. The pipe 26 has a nozzle 22 fixed to its end and is positioned to spray the solution along a path parallel to the direction in which the air and suspended cellulose fiber particles are flowing. The air flowing along the pipe 28 is sprayed from a second nozzle 30 which is positioned to provide a high velocity jet of air in a direction opposite to the direction of flow of the air and suspended cellulose fiber particles along the flow path 20. The two nozzles 22 and 30 are positioned opposite to one another so that the jet of air from the nozzle 30 will cause the stream of solution from the nozzle 32 to be atomized. If the solution being sprayed from the nozzle 22 has a low pressure, then the resultant spray will have a pattern illustrated by the spray pattern 32. If the solution from the nozzle 22 has a high pressure, then a spray pattern 34 will result.
The advantage of this method of contact between the solution and the cellulose fibers becomes clear when the density and surface mismatch between the fibers and the original dry chemical materials is considered from a mixing standpoint. By way of example, if 100 pounds per minute of fiber material is conveyed in a 4,000 scfm air stream, a superficial fiber density (neglecting fiber volume and air weight) of about 0.025 pounds per cubic foot results. The dry, solid chemical particles have a material density of approximately 150 pounds per cubic foot, resulting in a required flow rate of about 10 pounds per minute. On a dry, solid basis, the volume ratio would exceed 6,000 cubic feet air suspended fibers per cubic foot of solid chemical particles. When the respective dry surface contact areas between the fibers and chemical particles are taken into account, the contact mismatch is further aggravated. This severe contact mismatch between the relatively dense, coarse and lower mass of chemical and the relatively light and porous paper fibers is partially overcome when the chemical is dissolved into an aqueous solution thereby doubling in volume. The vigorous air atomization of the solution then provides the means of extending the surface and volume of the chemical in uniform proportions by several orders of magnitude thereby increasing manyfold the degree of uniformity with which the paper fibers are coated and impregnated with the chemical. Further, the dissolved chemical is virtually all in a colloidial, molecular or ionic form so that each of the millions of finely divided solution particles actually convey billions of sub-microscopic chemical particles which are readily and permanently absorbed into the microscopic paper fibers throughout their surface and volume.
Returning to FIGS. 1A and 1B, after the cellulose fibers are wetted, they are blown along the flow path 137 into the second cyclone separator 138. As the fine cellulose fibers travel along the flow path 137, they are dried by the hot air which is utilized as the flow medium. Thus, it is preferable to provide a flow of hot air along the flow path 137 which is sufficiently long to cause the particles to be substantially dry by the time they enter the cyclone separator 138.
For example, in one embodiment of the present invention, a process energy balance analysis showed that no additional heat was needed for drying, provided sufficient contact time was allowed for the process. A sufficient contact time was provided if the ducting defining the flow path 137 was 10 inches in diameter and 20 feet long giving a volume of approximately 11 cubic feet. If a temperature difference between the relatively dry air and the relatively moist fibers of 80° F. exists, then sufficient drying results.
Also provided in the flow path 137 is a pressure switch 134 which automatically stops the process if a blockage, sufficient to cause a pressure threshold to be exceeded, occurs in the system. In addition, a flow switch 136 is provided to likewise stop the system if a lack of material is sensed to be flowing along the flow path 137. The pressure switch 134 and the flow switch 136 may be coupled, for example, to the power circuit of an adjustable speed drive 196 controlling a solution injection pump 192 so as to turn off the injection pump 192. The pressure switch 134 and the flow switch 136 may also be coupled to shut down a drive motor 121 which provides the motive force to the hammermill 126. The operation of these switches will be further discussed subsequently.
The exhaust air from the second cyclone 138 is exhausted into the flow path 117 to pass through the filter apparatus 148. The treated and then dried cellulose fibers collected by the second cyclone separator 138 are then collected in a bagger bin 140. An adjustable speed drive motor 142 is coupled to a bagger screw 144 at the bottom of the bagger bin 140 from which the treated cellulose fibers may be withdrawn and placed in appropriate containers for shipment to the utilization site using a screw drive 142 and a motor 144.
The filter apparatus 148 receives the exhaust gases from the first cyclone separator 116 and the second cyclone separator 138 and filters small cellulose fibers from the flowing air and exhausting the air and solution vapors from the exhaust nozzle 151. The collected particles drop or may be shaken to the bottom of the filter apparatus 148 where they may be air conveyed along a flow path 153 which is coupled to the second cyclone separator 138. In order to move the air along the flow path 153, a source of compressed air 150 is initially provided to blow the collected cellulose fibers from the filter apparatus 148 and a fan 152 is provided in the flow path 153 to blow the particles so removed into the second cyclone separator 138. The filter apparatus may use any of a number of filtering techniques well known in the art for filtering particles from a stream of air.
The ratio of the chemical to cellulose fiber combined utilizing the injection nozzle means 132, which includes the solution nozzle 31 and the air jet nozzle 32 previously described in conjunction with FIG. 2, may be set and maintained by an automatic control system. The implement such a control system, an adjustable current relay 198 is provided to vary, and thus control, the current to the drive motor 121. By externally adjusting the adjustable current relay 198, the rate at which the hammermill 126 produces cellulose fiber particles inserted into the path 129 may be defined. The adjustable current relay 198 also provides a control signal to an adjustable speed drive 196 which provides the motive force for the injection pump 192. The amount of chemical solution pumped by the injection pump 192 will be proportional to the amount of cellulose fiber produced by the hammermill 126 and injected into the flow path 129 because of a signal follower 149, which generally will be incorporated as a part of the adjustable speed drive 196. A desired ratio between the chemical solution and the cellulose fiber mixture may be externally set by adjustment of the adjustable speed drive 196 to vary the rate at which the injection pump 192 operates in response to a given signal from the adjustable current relay 198.
In the preferred embodiment, a chemical solution flows along the path 189 in response to pumping action by the injection pump 192 and is therefrom caused to pass along a path 201 to the injection nozzle 132. Also incorporated as part of the injection pump apparatus is a pressure relief valve mechanism which senses pressure in the path 201. If the pressure sensed exceeds a threshold, a sensor 194 provides a signal to open a relief valve 197 to thereby relieve the pressure in the flow path 201 by releasing solution into the input flow path 189.
A pressure switch 200, a flow switch 202, a flow meter 204 and a solenoid valve 203 may also be placed in the flow path 201 to provide the process control to be described subsequently.
An auxiliary chemical solution feeder apparatus may also be provided and is particularly useful if the percolation method of obtaining a saturated solution is used. In a preferred embodiment, the auxiliary chemical solution feeder comprises an adjustable speed drive motor 212 coupled to operate a chemical solution feeder pump 210. The pump 210 is interposed in a flow path 211 along which auxiliary chemicals 208, held in an auxiliary chemical tank 206, are pumped. The flow path 211 is then coupled to the flow path 201 to thereby cause the auxiliary chemicals to be mixed with the fire retardant chemical solution, the mixture being inserted into and sprayed from the injection nozzle apparatus 132. The pumping rate of the pump 210 may be slaved to the rate of the drive motor 121 in a manner similar to that described in conjunction with the positive displacement injector pump 192. Thus, the signal follower means 149 may be used to provide a signal to the pump 210 to define the rate at which the pump 210 operates and thus the flow rate of the chemicals along the path 211.
The chemical solution flowing in the flow path 189 may be prepared by counterflow percolation of heated liquid upward through a fixed bed of soluble solid fire retardant chemical, such as raw phosphate prill. Such a process produces a supernatant consisting of a saturated solution at a fixed temperature. More particularly, a tank 171 is provided into which dry chemicals 154 may be placed. The resultant mass of chemicals forms a soluble bed 166 surrounding a perforated pipe 168 so that a chemical solution flowing along a pipe 159 is caused to pass through the perforations in the pipe 168 and percolate up through the soluble chemical bed 166 to form a saturated solution of the chemical 164.
The saturated solution 164 is drawn off through the baffles 174 into a pipe 179. A circulating pump 178 is provided to draw the saturated solution 164 from the tank 171 and cause it to pass through a heater 180 and into a pipe 181. A thermostat 182 is incorporated in the pipe 181 to monitor the temperature of the solution coming from the heater 180 and provide a signal to turn the heater off if the solution in the path 181 is too hot and on if the solution is too cool. By using thermostatic control, a saturated solution at a fixed temperature is provided with the concentration of chemical in solution defined since the concentration is a function of temperature.
A portion of the solution flowing along the path 181 is recirculated back into the tank 171. As the solution is decanted off and consumed in the process, tap water 156 is added to the tank 171, for example, by adding water to the pipe 179 to dilute the saturated solution flowing along the pipe 179 into the heater 180. A float switch 160 is provided in the tank 171 to sense the level of saturated solution and provide a signal to a solenoid valve 158 to allow tap water to be mixed into the saturated solution if the level of the tank falls below a certain value. Thus, the float switch 160 and the solenoid valve 158 combine to provide a means whereby the level of solution in the tank 171 is maintained.
The residue or sludge 170 which results from the process is collected in the bottom of the tank 171 and may be periodically drained through a drain by opening a valve 172.
In operation, a portion of the chemical solution flowing along the path 181 is bled off and passed along the pipe 165 to a settling feed tank apparatus 184 which comprises a basket strainer 188, a baffle 186 and a line strainer 187. The saturated solution circulates through the basket strainer 188 and baffle 186 and is drawn out by the pump 192. Any excess solution input to the tank 184 is caused to return to the holding tank 171 through an overflow drain 185. The settling tank 184 may also be provided with a downward sloping surface in the bottom of which is a drain valve 190 to allow the residue collected to be periodically drained off.
The proper concentration of chemical solution may also be obtained in a batch process. Thus, referring to FIG. 3, a specific quantity of chemicals 154 is placed in a mix tank 350. A set quantity of tap water 156 is added to the mix tank 350 along the pipe 352. A flow meter 354 may be placed in the pipe 352 to measure the quantity of water which has been input to the mix tank 350 so that a valve 364 may be turned off when sufficient water has been added. In order to obtain the chemicals in solution, compressed air is caused to flow along the pipes 360 and through the sparging venturies 358 to thereby cause turbulance in the mix tank to facilitate the solution of the chemicals in the water. Once the desired solution is obtained, the solution 164 may be drawn off through the baffle 356. A heater and thermostatic control (not shown) as previously described may also be utilized in this embodiment, as may the settling feed tank 184. A drain 362 is also provided in the mix tank 350 to allow sludge and other deposits to be drained periodically from the tank 350.
A block diagram of the arrangement of various controls and alarms which may be utilized in conjunction with the present invention is given in FIG. 4. The system may employ a combination of analog and binary signals to monitor and control automatic operations with manual overrides provided for all functions.
Specifically, a low chemical ratio control or indicator 420 is provided to monitor the ratio of chemical to paper being produced. Coupled to the low chemical ratio indicator 420 is the normally closed (NC) contact of the solution flow switch 202 which indicates subnormal chemical flow, the normally opened (NO) contact of a solution thermal switch 193 which is placed in the flow path 189 (FIG. 1B) and indicated subnormal temperature of the chemical solution, and the normally opened contact of the adjustable current relay 198 which indicates sufficient paper flow. If any of the above contacts in the normally opened or normally closed terminals of the switch are closed, then the low chemical ratio indicator 420 sends a signal to a horn and light 421 thereby energizing the flashing light and horn which indicates that insufficient chemical is being mixed with the cellulose fiber particles. Normally, the adjustable current relay 198 provides an analog signal to the adjustable speed drive 196 of the injection pump 192 on a lead 460 to control the operation of the chemical injection system including the pump drive and the solenoid valves. Thus, the low chemical ratio indicator 420 indicates the abnormal situation where proper solution flow is called for, but either insufficient flow volume or concentration fails to develop and a product deficient in chemical content is being produced. Such a situation calls for remedial action by an operator.
Corresponding to the low chemical ratio indicator 420 is the high chemical ratio 422. Coupled to the high chemical ratio indicator 422 is the normally closed contact of the adjustable current relay 198 which indicates a low paper flow when it is opened and the normally opened contact of the solution flow switch 202 which indicates a normal operating level of solution flow when it is closed. If both of these contacts are actually closed and conducting, then the high chemical ratio indicator 422 activates a bell and flashing light 423 which indicates that the ratio of chemical to paper being produced is too high.
In operation, such a situation will generally not occur because the adjustable current relay 198 will normally have generated an analog signal of a magnitude which would have shut down the adjustable speed drive 196 of the chemical injection pump 192, thereby avoiding overdosing the product with chemical and water and preventing excessive build-ups of these constituents in the ducting. If a high chemical ratio indication is given, however, operator attention is required.
A third indicator is the injector function 424 which receives a tachometer generator signal from a tachometer generator 415, indicating the rotation speed of the chemical injection pump; the analog signal from the adjustable current relay 198 along the lead 460 indicating the flow rate of the paper; and the output from the normally closed terminal of the flow switch 202, which indicates insufficient chemical flow. If either the rotational speed of the chemical injection 192 or the paper flow rate is sensed by the adjustable current relay as normal and the normally closed contact of the flow switch 202 is conducting indicating insufficient current flow, then the injector function 424 generates a signal to a light 425 indicating an injection system failure requiring operator action.
A fourth indicator is the injector clog indicator 426, which is coupled to the normally opened contact of the pressure switch 200 in the chemical flow path. If the normally opened contact of the pressure switch 200 is conducting, indicating an excessive injection pressure, then a warning light 427 is activated by the injector clog indicator 426 because of a probable blockage of the nozzle 132. Under this situation, it is preferable that the normally closed contact of the pressure switch 200, which will be non-conducting, be coupled to a start/stop relay 404 to shut down the adjustable speed drive 196 and, consequently, the chemical injection pump 492, to prevent excessive wear or damage to the pump 192.
A fifth control is provided by the ammeter 428 which is coupled to the analog signal on the lead 460 from the adjustable current relay 198 of the finish hammermill 126. The resultant analog signal is displayed on the ammeter 428 to visually indicate the level of paper flow as well as the mill load. Such an indicator provides the operator with the information needed to regulate the paper feed rate with remote control of the adjustable speed drive of the screw feeder 122.
To facilitate this function, the adjustable speed drive 120 of the screw feeder 122 is provided with an output volt meter 419 to indicate the drive speed selected. The mill load is controlled by manual adjustment of this speed from the remote control 412. An additional normally opened contact in the adjustable current relay 198 is coupled to a starter 403 to turn on or off the adjustable speed drive 120 and, thereby, interrupt the screw feeder is abornally high loads occur. Such a turn off control is automatic.
A sixth indicator which may be provided is a tachometer 416 coupled to the tachometer signal from the tachometer generator 415. The tachometer 416 thus provides a visible indication of the speed of the chemical injection pump. By comparing the tachometer value and the ammeter reading from the ammeter 428, proper operation of the signal follower which controls the proportional operation of the chemical injection system can be assured. Calibration curves and charts may be posted adjacent to these instruments to provide the operator with information on the chemical composition of the product during normal operation.
The next indicator is the low air indicator 430, which is coupled to the normally closed contact of the finish mill air flow switch 136. The low air control operates a warning light 431 which indicates the possibility of fan malfunction is the normally closed contact of the flow switch 136 is opened.
A filter clog indicator 432 may also be provided and coupled to the normally opened terminal of the pressure switch 134. When the normally opened switch terminal is closed, there is indicated an excessive back pressure in the flow path 137 (see FIG. 1). Such a condition initiates a warning light 433 indicating a need to clear the ducting 137 or clean the filter apparatus 148. The pressure level setting of this control is preferably sufficiently low that no interference or misinterpretation of the flow switch signal will occur.
A ninth indicator which may be provided is the high bag bin level indicator 434. A bag bin level detector 417 may be placed at a location in the bagger bin 140 (see FIG. 1) so that if the normally opened contact of the bag bin level detector switch is closed, a warning light 435 is turned on indicating that the bin 140 is too full. The normally closed contacts of the bag bin level detector 417 are also coupled to the starter 403 so that if the bin 140 is too full, the switch 403 is turned off and the adjustable speed drive 120 and, thus, the screw feeder 122 is shut down and no additional paper is processed until the level of product in the bin 140 is reduced. At that point, the resumption of the process will begin automatically.
A thermal switch 410 may also be provided in the breaker mill fan duct 115. In operation, the normally opened contacts of the thermal switch 410 close when the temperature level exceeds the normal operating range. The normally opened contacts are coupled to a fire alarm indicator 436 which initiates a siren and flashing light 437 when the normally opened contact is closed. The siren and flashing light indicates a fire hazard or actual fire in the breaker mill paper system requiring immediate operator attention. It will be appreciated that the principal fire hazard exists in this part of the process due to the flammability of the air suspended raw ground paper leaving the breaker mill and also due to the ever-present possibility of ignition by sparks generated by foreign objects passing inadvertently into the hammermill. Permanently installed chemical injection nozzles (installed at various points in the system-not shown) and supplied with fire retardant chemical solution from the process holding tank and circulating system and controlled by solenoid valves, provide the operator with an effective fire extinguishing method.
A high paper bin level indicator 438 coupled to the normally opened terminal of a paper bin level detector 418 in the paper bin 118 (FIG. 1), which, when closed, indicate that the bin 118 is full and causing a warning light 439 to be activated. In such a situation, the normally closed contacts of the paper bin level detector 418 open automatically interrupting the operation of the raw paper feed conveyor starter 401. Thus, no additional raw paper enters the breaker mill 112 until sufficient ground paper is processed through the finish mill 126 to bring the paper bin level down to the normal operating range.
In addition to the above-described indicators, various remote control or manual switches 411, 412 and 413 may be provided to activate the raw paper feeder conveyor 108, the screw feeder 122, the chemical injection pump 192, and the solenoid valves 203 and 205 in the chemical solution pipes. Various additional controls (not shown) may also be provided, including motor starters; electrical overload protection; tank level detectors and the make-up water solenoid valves; circulating pump flow switches; pressure switches for pump protection; bag air automatic controls for feeding, packing, weighing, counting, labeling, etc.; thermostatic control for solution heating; ph controlled chemical injection in the mix tank for fine adjustment of the solution composition; flow meters for instantaneous and totalized display and control of the solution feed and preparation; pressure relief valves for maximum safe pressure limits in the system; air pressure regulators for automatic control of the air flow in various parts of this system; and magnetic and air suspension separators for removing heavy foreign matter and raw materials.
By way of illustration, the present invention may be practiced according to the following where the primary fire retardant chemical utilized was monoammonium phosphate. Of course, it will be appreciated that the present invention is not so limited and may involve other solutions and formulations of a soluble nature. Indeed, small amounts of other chemicals, such as sulfur, silicate, sulfate, borate, sodium, potassium, halogens and other ions, such as those illustrated in patent application Ser. No. 870,385, filed Jan. 18, 1978 and now abandoned, by Robert J. McCarter, can produce additional fire retardant properties with further reduction in cost. According to the illustrated example, the batch method was utilized as described in conjunction with FIG. 3 in accordance with the following formulation:
______________________________________1. IMC 10-50-0 Suspension Grade Agricultural Monoammonium Phosphate (MAP) (Specification sheet appended) 5 400-lb Scoops (Skip Loader) 2000 lb2. Tap Water at 170° F. (initially) 34 ft.sup.3 (253 2120) lb3. Aqua Ammonia-Technical 29% NH.sub.3, 26° Baume (Specific Gravity: 0.9, Density; 7.49 lb per gal.) 30 gal. (Total); NH.sub.3 (29%) = 65 lb, H.sub.2 O (71%) = 160 lb 225 lb Solution Batch Total 4345 lb4. Composition MAP % 46.0 NH.sub.3 % 1.5 H.sub.2 O % 52.5 100.005. Trace Fungacide: Dow-cide™ (Sodium Pentachlorophenate) 197 grams = 6.94 oz. - 0.4345 lb 100 ppm______________________________________
The plant, operating in the manner previously described, produces a steady output of from 2 to 3 30-lb bags per minute of finished insulation. The finish mill 126 flow characteristics are given in FIG. 5 for dry #1 newsprint broken through a 11/4 inch screen and fed to a Forster Model No. 2, Ser. No. 259-R hammermill with a 12/16" screen and direct-driven by a 125 hp G.E. 505S Frame 440/480 volt, 60 HZ., 3-phase, 2-pole, 3450 rpm motor. A 16 inch diameter paper screw feeder is driven through a 62.5 to 1 reduction by a 7.5 hp, 220 vdc shunt-wound motor. The solution injection system characteristics are given in FIG. 6 for the solution formulation given above where there was 47% solids at 130° F., 11.0 lb/gal density using a Teel Model 1P610 progressive cavity-type belt driven pump at a 3.5 to 5 reduction and powered by a Century shunt-wound dc motor rated by 1.0 hp at 1750 rpm. A typical mill operating condition is as follows:
______________________________________Paper Feeder Set, volts dc 60Screw Drive Speed, rpm 480Screw Speed, rpm 8Finish Mill amps 100Paper Flow, lb/min 80Pump Speed, rpm 770Pump Drive Speed, rpm 1100Injector Pressure, psig 20Solution Flow, gpm 1.75______________________________________
This operating condition produces a finished material having the following composition, properties and specifications as manufactured:
______________________________________Chemical Content (dry basis) % by Weight 10.3Fungacide Content (dry basis) ppm 10.3Moisture Content, % by Weight 5.4Flame Spread Rating (ASTM E-84, 2-ft Tunnel)Conditioned Sample, Fresh 26Aged Sample 22______________________________________
Since certain changes may be made in the foregoing disclosure without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description and drawings be construed as illustrative and not limiting. | A cellulose fiber insulation, a manufacturing method and a plant for practicing the method. Waste paper is pulverized in a hammermill apparatus to provide a quantity of cellulose fiber particles which are air conveyed past a fog-type injection nozzle where the particles are wetted with a solution of fire and/or pest resistant and corrosion inhibiting chemicals. The wetted particles are thereafter air conveyed away from the nozzle with heated exhaust air from the hammermill apparatus to dry the particles prior to depositing them in a storage bin. The air by which the particles are conveyed may be exhausted through a filter to catch residual particles which may be returned to the storage bin or directly to the process. The sprayed solution may be prepared by a batch process or by counterflow percolation of heated liquid upward through a bed of soluble fire-retardant chemical. The concentration of chemical in the resultant saturated solution may be regulated by a thermostatic control system. The weight ratio of solution to cellulose fiber may be controlled by sensing the flow rate of the cellulose fiber and generating signals to regulate the rate at which the solution is sprayed from the nozzle. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of Korean Application Nos. 10-2005-0057821 and 10-2005-0058011 both filed on Jun. 30, 2005, which are hereby incorporated by reference as if fully set forth herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to laundry machines, and more particularly, to a control unit assembly for controlling a laundry machine.
2. Discussion of the Related Art
In general, the laundry machine is a general term for a washing machine for washing and spinning, a dryer for drying, a dryer and washing machine for washing and drying. In the washing machines, there are a drum type washing machine and a pulsator type washing machine.
Of the washing machines, the drum type washing machine removes dirt from laundry by friction taken place between washing water and the laundry as the laundry is dropped by a weight of the laundry lifted as a drum coupled to a motor with a shaft rotates in regular/reverse directions by rotation force of the motor, after introduction of the laundry into the drum type washing machine, and supply of the washing water to the drum through a detergent box together with detergent in the detergent box.
Owing to less entangling of the laundry, and an excellent washing capability compared to the pulsator type washing machine, recently the drum type washing machines spread, rapidly.
A related art drum type washing machine will be described with reference to FIG. 1 .
The drum type washing machine is provided with a substantially hexahedral body 1 , having a laundry opening in a front for introduction and taking out the laundry, with a door 2 on one side of the front having the laundry opening for selective opening/closing of the laundry opening.
At an upper portion of the front of the body 1 , there is a control unit 3 for operation of the drum type washing machine.
The control unit 3 is provided with a plurality of buttons and a rotary knob for user's application of washing functions, and a display window for displaying a progress of operation of the drum type washing machine.
The control unit 3 assembly will be described in more detail with reference to FIG. 2 .
The control unit is provided with a control panel 31 which forms an exterior of the control unit 3 , a printed circuit board (PCB) 32 having various electric devices mounted thereon, and a coating guide 33 for mounting the PCB 32 .
The control panel 31 is provided with fastening portions for coupling the coating guide 33 thereto. The fastening portions are fastening bosses 31 a projected outwardly from a rear surface of the control panel 31 , respectively.
Moreover, on the front of the control panel 31 , there are a plurality of pass through holes 31 b , buttons 31 c , and transparent windows 31 d , for user's easy operation and notice of operation progress.
Referring to FIGS. 2 and 3 , in order to make the exterior of the drum type washing machine elegant, the exterior of the control panel 31 is curved.
Mounted on the PCB 32 , there are electric devices for controlling operation of the drum type washing machine, input devices 32 a , such as the knob or switches, and so on for transmission of control signals of the drum type washing machine to the control unit (not shown), and display devices 32 b , such as LED lamp, for displaying a progress of operation.
The coating guide 33 receives the PCB 32 , and has fastening portions 331 at an upper portion and a lower portion in correspondence to the fastening bosses 31 a on the control panel 31 for coupling the coating guide 33 to the control panel 31 .
Each of the fastening portions 331 has a fastening hole 331 a . At the time of coupling the coating guide 33 to the control panel 31 , the fastening bosses 31 a and the fastening holes 331 a are brought into contact respectively, and screws are driven thereto from a rear surface of the fastening portions 331 .
However, the related art control unit assembly has the following problems.
First, as can be known from FIG. 3 , the coupling of the coating guide 33 having the PCB mounted thereon to an inside of the control panel 31 with the curved exterior surface causes to form a large gap T between the input devices 32 a and the display devices 32 b on the PCB and the control buttons and so on on the control panel 31 , to cause problems of defective contact between the input device 32 a and the buttons 31 c , and poor brightness of the display device 32 b at the transparent window 31 d due to the large gap between the display device 32 b and the transparent window 31 d.
Second, referring to FIG. 4 , there have been poor alignments happened between the coating guide 33 having the PCB mounted thereon and the control panel 31 in processes of coupling the coating guide 33 to the control panel 31 , i.e., the input device 32 a and the display device 32 b on the PCB 32 are aligned with the buttons and the transparent window on the control panel 31 , inaccurately.
That is, in the process for coupling the coating guide 33 to the control panel 31 , there can be misalignment between the fastening hole 331 a in the fastening portion 331 and the screw hole in the fastening boss 31 a . In this case, it is liable that the worker forcibly fastens a screw through the screw hole in the fastening boss 31 a and the fastening hole 331 a in the fastening portion 331 , failing exact contact of the button on the control panel 31 with the input device 32 a on the PCB 32 and exact match between the LED lamp 32 b of the PCB 32 and the transparent window 31 d in the control panel 31 .
The mismatch between the LED lamps 32 b with the transparent window 31 d , causing the LED lamps to illuminate wrong transparent windows, is liable to make the user misunderstand operation of the drum type washing machine.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a laundry machine that substantially obviates one or more problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a laundry machine having a control unit assembly of an improved structure which can improve an assembly work of the control unit assembly, and enables exact match between relevant components in the assembly.
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.
To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a laundry machine includes a drum, a cabinet which forms an exterior of the laundry machine and protects the drum, a control panel having various operational buttons for operation of the drum, and coupling portions, a plurality of coating guides having fastening portions corresponding to the coupling portions for mounting to a rear surface of the control panel, a plurality of printed circuit boards (PCB) respectively mounted on the coating guides each having an electric circuit mounted thereon, joining portions for joining the coating guides together so as to place the coating guides closer to an inside of the control panel, and holders for preventing the coupling portions and the fastening portions from moving with respect to each other at the time the coupling portions are brought closer to the fastening portions, respectively.
Preferably, the fastening portion includes walls on an upper portion of the coating guide having fastening hole, and the holder includes at least one rib projected from the wall around the fastening hole.
Preferably, the holders are formed opposite to each other with respect to the fastening hole.
Preferably, the coupling portion includes a fastening boss, and the holder has an end sloped for easy placing in of the fastening boss.
Preferably, the holders opposite to each other with respect to the fastening hole is distanced enough to allow sliding of the fastening boss.
Preferably, the fastening portion is walls on an upper portion of the coating guide, and the holder is a cylinder projected from the wall around the fastening hole.
Preferably, the cylinder has an inside diameter with a size enough to allow sliding of the fastening boss.
Preferably, the fastening portion is walls on an upper portion of the coating guide, and the holder is an arc projected from the wall around the fastening hole.
The holder may be formed on an upper side and a lower side or a left side and a right side of the fastening hole.
Preferably, the joining portion is formed on a side of each of the coating guides.
Preferably, the coating guides joined together form an outside appearance having a curvature at which the PCBs and the operation buttons can be placed closer.
Preferably, the joining portion includes a hook on one of the coating guide, and a joining surface on the other coating guide having a hook hole for holding the hook.
Preferably, at least one hook and hook hole are formed, respectively.
Preferably, a plurality of hooks are formed, and the plurality of hooks have holding directions to be held at the hook holes different from one another.
Preferably, the joining portion further includes position guide means for guiding the hook to the hook hole for easy fastening of the hook to the hook hole.
Preferably, the position guide means includes a guide projection from one of the coating guides, and a guide projection receiver at the other coating guide for receiving the guide projection.
Preferably, the projection is adjacent to the hook.
Preferably, at least one of the guide projections and the guide projection receivers are formed, respectively.
In another aspect of the present invention, a control unit assembly includes a control panel having various operation buttons and coupling portions, a plurality of coating guides coupled to a rear surface of the control panel having fastening portions corresponding to the coupling portions, a plurality of printed circuit boards respectively mounted on the coating guides, each having an electric circuit mounted thereon, joining portions for joining the coating guides together so as to place the coating guides closer to an inside of the control panel, and holders for preventing the coupling portions and fastening portions from moving with respect to each other when the fastening portions are aligned with the coupling portions.
The drum type washing machine of the present invention has the following advantages.
The placing of the PCB mounted on the coating guide closer to the inside of the control panel, enabling accurate alignment of the buttons and the transparent windows on the control panel with the input devices on the PCB, permits to enhance perfection of the product.
The placing of the PCB mounted on the coating guide closer to the inside of the control panel, enabling accurate alignment of the buttons and the transparent windows on the control panel with the input devices on the PCB, permits smooth operation of the buttons, and to provide an accurate operation progress to the user.
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
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 embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings;
FIG. 1 illustrates a perspective view of a related art drum type washing machine;
FIG. 2 illustrates an exploded perspective view of a control unit of a related art drum type washing machine;
FIG. 3 illustrates a plan view of a control unit of a related art drum type washing machine, schematically;
FIG. 4 illustrates a transverse section of a control unit of a related art drum type washing machine;
FIG. 5 illustrates an exploded perspective view of a control unit of a drum type washing machine in accordance with a preferred embodiment of the present invention;
FIG. 6 illustrates a plan view of a control unit of a drum type washing machine in accordance with a preferred embodiment of the present invention, schematically;
FIG. 7 illustrates an enlarged view of “A” part in FIG. 5 ;
FIG. 8 illustrates a transverse section of a control unit of a drum type washing machine in accordance with a preferred embodiment of the present invention; and
FIG. 9 illustrates an exploded perspective view of a control unit of a drum type washing machine in accordance with another preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the preferred 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.
A control unit assembly 3 of a drum type washing machine will be described with reference to FIG. 5 .
Referring to FIG. 5 , the control unit 3 assembly includes a printed circuit board (PCB) 32 having various electric devices mounted thereon for operation of the drum type washing machine, a control panel 31 which forms an exterior of the control unit, and a coating guide 33 having the PCB 32 mounted thereon and fastening portions 331 for coupling the coating guide 33 to the control panel 31 .
The PCB 32 has the electric devices mounted thereon for controlling the drum type washing machine.
The PCB 32 has input devices 32 a , such as switches and knobs, for user's direct control of the electric devices, as well as display devices 32 b , such as LED lamps for displaying a progress of washing of the drum type washing machine.
In the meantime, after mounting the PCB 32 on the coating guide 33 , coating liquid is applied thereto as an water proof treatment.
This is because the drum type washing machine 1 has frequent contact with water due to the introduction/taking out of the wet laundry. That is, the coating prevents the electric devices on the PCB 32 from being happened to contact with water.
On the other hand, the control panel 31 forms an exterior of the control unit and protects the electric devices mounted on the PCB 32 .
In addition to this, the control panel 31 has button portions 31 c connected to the input devices 32 a on the PCB 32 for user's control of the drum type washing machine from an outside thereof, and transparent windows 31 d for transmission of a light from the display devices 32 b on the PCB 32 .
It is preferable that the button portions 31 c are push buttons for user's easy operation.
It is preferable that the control panel 31 has fastening portions for coupling the coating guide 33 to the control panel 31 , preferably formed of a plurality of fastening bosses 31 a.
The coating guide 33 includes a body 321 of rectangular plates each having a cavity for receiving the PCB 32 , and a plurality of fastening portions 331 at an upper portion and a lower portion of the body 321 .
It is preferable that the body 321 has individual bodies in correspondence to a number of the PCBs 32 . For reference, though the embodiment shows two bodies 321 and two PCBs 32 , number of the bodies 321 and the PCBs 32 are not limited to two. In the following description of the embodiment, the individual bodies 321 a and 321 b will be called as a first body 321 a and a second body 321 b.
In the meantime, it is preferable that each of the bodies 321 a and 321 b has supporting members 35 formed on an inside for supporting the PCB 32 , more preferably with holding members 34 for preventing the PCB 32 supported thus from falling off to an outside of the body 321 a , or 321 b.
The fastening portions 331 at the upper portion and the lower portion of the body 321 are formed to match to the fastening bosses 31 a on the inside of the control panel 31 .
In this instance, the fastening portion 331 has at least one face directed upward vertically, and a fastening hole 331 a in a fastening surface 331 b opposite to the fastening boss 31 a.
Also, the fastening portion 331 has opposite walls 331 c , and a holder 331 d on an inside of each of the opposite walls 331 c and on an upper surface of the body 321 in contact to the inside of the opposite walls 331 c perpendicular thereto.
It is preferable that the holder 331 d is a rib projected outwardly from a fastening surface 331 b , more preferably three in total around the fastening hole 331 a . This is for making movement of the fastening boss 31 a the smallest by supporting the fastening boss 31 a from three directions at the time the fastening boss 31 a of the control panel 31 is in contact with the fastening hole 331 a.
It is preferable that the ribs 331 d have distances centered on the fastening hole 331 a which permits the fastening boss 31 a slide.
It is preferable that the body 321 has a plurality of wire fastening ribs 36 formed on upper and lower sides of the fastening portion 331 for fastening wires lead from the PCB 32 .
The body 321 has joining portions 40 for joining the individual bodies 321 a and 321 b together. The joining portions 40 are on sides of the bodies 321 a and 321 b respectively, for joining the bodies 321 a and 321 b , together.
In this instance, referring to FIG. 6 , it is preferable that a plan view of an outside appearance of the first body 321 a and the second body 321 b joined together with the joining portions 40 is not in straight line, but knuckled at a predetermined angle.
It is preferable that the curvature the two bodies 321 a and 321 b form is the same with the curvature of the exterior of the control panel 31 . This is for placing the input devices 32 a on the PCB 32 mounted on the coating guide 321 closer to the button portions 31 c , the transparent windows 31 d and so on of the control panel 31 .
That is, this is for enhancing accuracy of alignment of the button portions 31 c with the input devices 32 a by placing the input devices 32 a closer to the button portions 31 c of the control panel 31 at the time the coating guide 32 is coupled to the control panel 31 .
The joining portion 40 will be described in more detail with reference to FIG. 7 .
The joining portion 40 includes hooks 41 on a side of the second body 321 b of the plurality of individual bodies 321 a and 321 b , and a joining surface 42 having hook holes 42 a on a side of the first body 321 a which is to be coupled to the second body 321 b for holding the hooks 41 on the second body 321 b.
Though the embodiment shows the hooks 41 on the second body 321 b and the joining surface 42 on the first body 321 a , it does not matters even if positions of the hooks 41 and the joining surface 42 are interchanged.
It is preferable that numbers of the hooks 41 and the joining surfaces 42 are at least one, respectively. It is preferable that at least one hook hole 42 a is formed in the joining surface 42 , for enabling hooking of a plurality of hooks 41 to the joining surface 42 .
The embodiment shows three hooks 41 on the side of the second body 321 b . The joining surface 42 has spaces for receiving the hooks 41 respectively, and sockets each with a hook hole 42 a in a circumference for holding the hooks 41 .
It is preferable that the hooks 41 have holding directions different from adjacent one, more preferably, as shown in FIG. 7 , opposite to adjacent one.
The socket shape of the joining surface 42 also has a plurality of hook holes 42 a equal to a number of the hooks 41 , and the hook holes 42 a are formed in opposite directions of the joining surfaces 42 in order to match to the hooks 41 formed in opposite directions. According to this, a plurality of the joining surface 42 are formed.
Shapes of the hook 41 and the joining surface 42 are not limited to the embodiment.
Thus, as the hooks 41 are held at the hook holes 42 a , the first body 321 a and the second body 321 b are coupled, and because the hooks 41 are held at the hook holes 42 a in opposite directions, even if the coating guide 33 is pressed in one direction, the hooks 41 do not fall off the hook holes 42 a , to couple the first body 321 a and the second body 321 b , more firmly.
Moreover, the joining portion 40 may further include guide means for guiding joining positions of the hooks 41 and the socket shape of joining surface 42 .
Referring to FIG. 7 , it is preferable that the position guiding means holds the first body 321 a and the second body 321 b so that the first body 321 a and the second body 321 b do not move in addition to a function for guiding joining positions of the hooks 41 and the joining surfaces 42 .
The position guiding means includes a guide piece 43 projected from a side of the first body 321 a , and a guide piece receiver 44 on a side of the second body 321 b for receiving the guide piece 43 .
It is preferable that at least one guide piece 43 is formed adjacent to each of the hooks 41 .
It is preferable that the guide piece receiver 44 is formed within a space of the socket shaped joining surface 42 of the first body 321 a.
It is preferable that the guide piece 43 is formed to fit in the guide piece receiver 44 , for preventing the first body 321 a and the second body 321 b coupled together from moving.
A process for coupling the coating guide having bodies joined together to the control panel will be described.
The PCB 32 is mounted on the coating guide 33 . Then, the coating guide 33 is fastened to the control panel 31 with screws.
In this instance, the fastening bosses 31 a on the inside of the control panel 31 are brought into contact with the plurality of fastening portions 331 on the coating guide 33 , respectively.
In this instance, the fastening boss 31 a is guided by the holders 331 d on the fastening portion 331 until the fastening boss 31 a is in contact with the fastening surface 331 b having the fastening hole 331 a , such that the screw hole in the fastening boss 31 a is aligned with the fastening hole 331 a in the fastening portion 331 .
In this instance, lateral movement of the fastening boss 31 a is held by the holders 331 d so that the fastening boss 31 a is aligned with the fastening surface 441 b exactly without any lateral movement.
By this, referring to FIG. 8 , the coating guide 33 can be easily fastened to the control panel 31 having the fastening boss 31 a aligned with the fastening surface 441 b , exactly.
In the meantime, the wires lead from the PCB 32 are fastened to the wire fastening ribs 36 on the upper portion and the lower portion of the body 321 , to arrange the wires neatly, and to prevent the wires from coming between the body 321 and the control panel 31 to cause inaccurate assembly.
A coating guide in a drum type washing machine in accordance with another preferred embodiment of the present invention will be described with reference to FIG. 9 attached herein.
The coating guide in a drum type washing machine in accordance with another preferred embodiment of the present invention is identical to the coating guide in a drum type washing machine in accordance with a preferred embodiment of the present invention, except the holder.
The holder 50 has a section of an arc around the fastening hole 331 a of the fastening portion 331 projected from the fastening surface 331 b , formed on upper and lower sides or right and left sides of the fastening hole 331 a.
Though not shown, the holder 50 may have, not only a shape of the arc, but also a shape of a cylinder having the same arc.
If the holder 50 has the shape of a cylinder, it is preferable that an inside diameter of the cylinder has a size to allow the fastening boss slides in/out therethrough.
A process for assembling the control panel 31 to the coating guide 33 will be described.
Once an outside circumferential surface of the fastening boss 31 a of the control panel 31 is placed on an inside circumferential surface of the arc or cylinder shaped holder 50 , the fastening hole 331 a of the fastening portion 331 having the holder 50 formed thereon is aligned with the screw hole in the fastening boss 31 a.
In this instance, since the fastening portion, placed in the fastening boss 31 a , does not move, the control panel 31 can be fastened to the coating guide 33 with screws, easily.
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. | The present invention relates to laundry machines, and more particularly, to a control unit assembly in a laundry machine which enables easy assembly and accurate alignment of an input device of a printed circuit board with a button portion of a control panel.
The control unit assembly includes a control panel having various operation buttons and coupling portions, a plurality of coating guides coupled to a rear surface of the control panel having fastening portions corresponding to the coupling portions, a plurality of printed circuit boards respectively mounted on the coating guides, each having an electric circuit mounted thereon, joining portions for joining the coating guides together so as to place the coating guides closer to an inside of the control panel, and holders for preventing the coupling portions and fastening portions from moving with respect to each other when the fastening portions are aligned with the coupling portions, thereby improving assembly work, preventing malfunction of the laundry machine, and permitting easy detection of an operation progress. | 3 |
FIELD OF THE INVENTION
The present invention relates generally to the field of producing encased food emulsion products and more specifically to the production of consistent dimensions and density within such products as they are encased.
BACKGROUND OF THE TECHNOLOGY
In the food emulsion packaging industry, products such as sausage, frankfurters, various cheeses, processed hams, bologna, etc., are produced and packaged in casings. The casing materials are either natural or synthetic and are variously edible and nonedible. Predominantly, shirred casing sticks are used in the stuffing of food emulsion products, the casing material being in tubular form. A casing stick is produced from axially compressing a length of tubular casing material such that accordion-like pleats are formed, substantially decreasing the length of the tubular casing material from extended lengths of 70 to 100 feet or more to compressed lengths which may be only as long as 10 to 20 inches. Typically, the shirring of tubular casing material has been a separate operation from that of stuffing the casing to produce the food emulsion products. More recently, the shirring of the casing has been done by various methods, using automated equipment, directly in conjunction with the operation of the stuffing equipment itself, especially in highly automated stuffing operations. When such "on-site" shirring methods are employed, typically a length of tubular casing material is shirred rapidly and then, in its shirred form, is immediately transferred to and fitted over, for example, a stuffing horn which forms an extension from a food emulsion pump. Regardless of the method used, the shirred casing stick ends up being axially telescoped onto the stuffing horn which then extends through the bore of the casing stick.
Food emulsion products range in diametrical size from rather small, such as, for example, Vienna sausage, up to relatively large sizes such as, for example, bologna. Regardless of the diametrical size of the end product, the method of stuffing the food emulsion into the casing is predominantly the same: the stuffed food emulsion is pumped through a stuffing horn into a tubular casing which is paid out from a shirred stick which has been fitted over the stuffing horn. (In some situations, nonshirred casings are used to produce larger diameter products.) The pressure and force exerted by the moving food emulsion extrusion pulls the casing, into which the food emulsion is being stuffed, along with it, thus packaging the product. Various means, well known to those with skill in the art, are employed to form the encased food product into links, as might be found in frankfurters, or into chubs which is a term applied to lengths of bologna. Various means are used to separate and cut off the lengths or chubs.
Large sausage products are predominantly used in producing sliced products for sale to the public. Much of this sliced product business today is based on selling prepackaged quantities wherein the sliced pieces must have consistent texture, density and size to enhance customer appeal and also so the packaged product, package by package, is consistent in weight. It is very common to find sliced prepackaged products which have a consistent weight of, for example, 12 ounces. For smaller food emulsion products, such as frankfurters, there are normally a set number of pieces in a given weight package such as, for example, 10 frankfurters in a 16 ounce (one pound) package. Cheeses are normally sold in either presliced packages of consistent weight or in short cylindrical sections which consistently weigh, for example, one pound. To produce such products having consistent weight, the stuffing operation must be able to produce a product which has consistent density and a consistent cross sectional size. For sliced products, this insures that each slice will weigh exactly the same as each other slice. For link products each link would weight exactly the same as each other link. Thus the packaging of these products can be accomplished on automated high speed packaging equipment without the necessity to weigh and mark each separate package. In addition, sizing of the pieces to be prepackaged is important to ensure that they will fit uniformly into the packaging that was designed for them.
Over many years the industry has determined through experience (trial and error), the optimum stuffing and processing conditions for various types of food emulsion products. Such products generally are sought to be stuffed and encased to an ideal "green" or unprocessed diameter. When a casing is understuffed from the recommended green diameter, the resultant product is usually not uniform in diameter from end to end and from piece to piece. The product may have a wrinkled appearance caused by the casing not being fully expanded to the extent of its design. This, by itself, creates a product with diminished appeal to the customer. In addition, there is a tendency for such understuffed products to have what is known as "emulsion breakdown" resulting in the formation of pockets of fat or liquid which further degrade the product in respect to end use. Such an understuffed product, of course, cannot be used for prepackaging where consistent weight and sizing are critical. On the other hand, when a casing is overstuffed beyond the recommended green diameter, the elastic limits of the casing material may be exceeded, causing the casing material to split and break apart either at the stuffing station or subsequently, in transport, or in cooking, smoking or other processing operations. The result is wasted product and the complications, labor and expense which are necessary for the clean up. Even if the elastic limits of the casing material are not exceeded, because the thickness and compositional consistency of the casing material varies to some degree, overstuffing may well cause bulges resulting in inconsistencies in the cross sectional sizing of the food emulsion product, from end to end, over its length. As mentioned before, such can readily result in inconsistent piece or link weights for prepackaged products, and may cause difficulty in the actual packaging due to inconsistent size control.
Many devices and systems have been proposed and are well known to those with skill in the art for controlling the pay out of tubular casing material from the shirred casing stick on the stuffing horn. These generally fall into two categories. The first of these categories is referred to as a brake. A brake system usually acts to apply circumferential pressure or force onto the outside of the casing material at a point which is adjacent to the end of the stuffing horn. Thus, the casing material must traverse a small space between the outside diameter of the stuffing horn and the inside diameter of the brake. The function of a brake is to provide an interference fit between the brake and the stuffing horn such that a desired degree of force is required to pull the casing material through the small space. Some variation in the sizing of this small space can be applied by increasing or decreasing the pressure imposed by the brake means. For example, the brake means may be a resilient ring made of some sort of synthetic elastomer with its inside diameter axially being smaller than the outside diameter of the stuffing horn. With such a device, typically the brake ring is forced over the end of the stuffing horn, expanding the elastic brake ring such that consistent pressure is placed circumferentially onto the outside diameter of the tubular casing material. This pressure results in friction between the outside surface of the casing material and the brake ring as well as the inside surface of the casing material and the stuffing horn
Sizing devices, on the other hand, take the form of discs or rings, of a given set size, which are placed over the stuffing horn adjacent to its outlet end, being arranged such that the casing material must traverse over the sizing device. The principal of operation is that the sizing device is set and designed to expend the casing material, and in some cases slightly stretch it to its ultimate diameter, as the casing material traverses over the sizing device. Sizing devices tend to take out substantially all of the folds, pleats and wrinkles in the casing material and, further, to impose a frictional contact to the moving casing material as it passes over the sizing device. Thus, a given amount of pressure and force is required to pull the casing material over the sizing device. The pulling force and pressure, which move the casing material over the sizing device, are supplied by the moving food emulsion being extruded and stuffed into the casing.
In many cases, combinations of brake systems and sizing devices are used, the arrangement typically being that the casing material first is pulled over the sizing device and then through the small space between the brake means and the stuffing horn. Such combined arrangements are said to provide the ultimate degree of control over the pay out of the casing material as it moves from the shirred casing stick to the output end of the stuffing horn where the extruding food emulsion actually enters the casing. Various brake systems provide some degree of adjustment of the frictional pressure being applied to the casing material which is traversing the brake. However, there are no known effective methods for adjusting the frictional force being applied to the interior of the casing by the sizing devices as the casing material is in motion during the stuffing of the casing.
Because there are variations in casing wall thickness and compositional consistency, as well as variations in the consistency and density of the food emulsion as it exits the output end of the stuffing horn, it is desirable to provide as much control as possible to the flow of casing material being paid out from the shirred casing stick. It is known in the industry that, in respect to a given size of casing, increasing the diameter of the sizing disc increases the casing hold back by way of increasing the force required to overcome the friction between the sizing disc and the inside wall of the casing. However, this approach has its limitations in that care must be taken not to force the size of the casing material beyond its elastic limits or to provide too much frictional contact such that the extruding food emulsion overstuffs the casing, causing the problems discussed above. On the other hand, undersizing the sizing disc can result in the production of understuffed green product and the problems, likewise, discussed above.
As mentioned above, the problem is that, in respect to the sizing devices that are known, no means are known or available by which the sizing devices can be effectively adjusted after the stuffing operation commences. Unfortunately, the above-discussed variations and inconsistencies do not become readily apparent until the stuffing operation is commenced, and the only way, at that point, of compensating for such variations and inconsistencies is by halting the stuffing operation to make adjustments. This necessitates disassembly of the system as the shirred casing stick needs to be removed from the stuffing horn, either to make adjustments to the sizing device or to install a different size of sizing device. In the high-speed automated operations used at present in the food stuffing industry, not only is such a requirement undesirable and impractical but it also is considered intolerable. As a result, much attention has been focused on improving the consistency and wall thickness of the casing material as well as on improving the consistency and density of the food emulsion as extruded. Although significant strides have been made in improving these areas, the variables and inconsistencies still exist and are still a notable factor inhibiting optimization of the production of encased food emulsion products.
U.S. Pat. Nos. 3,457,588 and 3,553,769 teach the use of an unusually complicated and cumbersome adjustable sizing device with several, typically four, sizing elements which can be radially expanded outwardly from the stuffing horn by simultaneously turning elongated shafts. The elongated shafts are extended parallel to the axis of the stuffing horn to about the point where the stuffing horn is connected to the food emulsion pump. The elongated shafts are rotated simultaneously through a system of toggle links driven by a means for producing linear motion, i.e., a machine screw.
U.S. Pat. No. 4,202,075 also teaches means for adjusting the size of a sizing device. The sizing device taught by this reference is formed from a tubular mechanism with an enlarged end which radially engages the internal surfaces of the casing being drawn across it. The mechanism disclosed by U.S. Pat. No. 4,202,075 does not provide any means for adjustment of the sizing device during the stuffing of the casing, but rather, only when the casing material is stationary.
U.S. Pat. No. 4,535,508 teaches the use of an expandable casing sizing mechanism with sizing members which are radially expandable in contact with the internal casing surfaces. However, like the device shown in U.S. Pat. No. 4,202,075, the apparatus of U.S. Pat. No. 4,535,508 is not adjustable during the casing stuffing operation when the casing material is moving.
U.S. Pat. No. 4,512,059 discloses a rigid petal-like sizing member, including means for applying force for outwardly expanding the device against the inner surface of the casing. In this device, the force for expanding the petals of the sizing member is provided by the movement of the casing itself, but is not adjustable to vary the amount of force being applied to the moving casing material.
U.S. Pat. 4,528,719 discloses a sizing ring comprising two pieces. The two pieces are compressed together, one element inside the other, to expand the device against the interior of the moving casing material, but not while the casing material is moving.
U.S. Pat. Nos. 4,077,090 and 4,164,057 both disclose a combination sizing device and brake ring assembly. The sizing device is mounted on a slidable sleeve, fitted onto and over the stuffing horn. The sleeve is moved reciprocally along the longitudinal axis of the stuffing horn. Longitudinal movement of the sleeve causes the sizing device to engage the inside wall of the casing and push it against a stationary brake ring, thus applying adjustable frictional force to both the inside and outside walls of the casing material before it comes into contact with the stuffing horn. Following this, the flow of casing material is redirected against the stuffing horn and through a more or less conventional brake ring. In these two patents, however, there is no means included for adjusting the sizing or braking forces during the stuffing of the casing.
U.S. Pat. No. 4,727,624 teaches a single piece sizing device of resilient material which can be expanded and contracted radially, adjusting the pressure imposed on the inside surface of the casing material. Unlike many of the previous sizing devices, the apparatus of U.S. Pat. No. 4,727,624 may be adjusted during the stuffing of the casing by longitudinal movement of a pipe which is fitted over the stuffing horn, the pipe being extended toward the food emulsion pump to the input end of the stuffing horn and beyond the remote end of the shirred casing stick which is fitted over the pipe. Longitudinal motion of the pipe imposes pressure onto the one piece sizing device which, in turn, expands radially to increase the pressure on the inside surface of the casing material. This causes hold back and expansion of the casing material simultaneously. However, the adjustment can only be accomplished if the food emulsion extrusion is halted, and thus this sizing device is not designed for adjustment while the casing material is moving.
None of the foregoing patents describe or disclose an uncomplicated or noncumbersome sizing mechanism which is both adjustable during the stuffing operation and wherein the sizing mechanism does not need to be removed from the stuffing horn in order to load casing material onto that stuffing horn. In addition, none of the foregoing devices are readily adaptable to the automated, on-site casing shirring mechanisms with automated food emulsion stuffing systems, both of which are becoming increasingly and prominently used in the food emulsion stuffing industry. Such devices usually require casing material which has been previously shirred into casing sticks at a separate location. Accordingly, means are needed which are adaptable to shirring and can provide sizing of the casing material as it is paid out from the stuffing horn, to both size the casing material by expanding and smoothing it from its shirred state and to provide hold back to insure correct sizing of the stuffed food emulsion product as explained previously. Such sizing means should be adjustable during stuffing operations to compensate for the variations in both the food emulsion being extruded and in the casing material, should be adjustable to provide casing material expansion where desired and should be operable to either permit the fitting of a shirred casing stick thereover without removal of the sizing means from the stuffing horn or permit the shirring of the casing material as it is telescoped onto the stuffing horn, likewise, without removal of the sizing means from the stuffing horn.
SUMMARY OF THE INVENTION
The present invention comprises means for sizing food emulsion casing material as it is paid out from the end of, for example, the stuffing horn of a food emulsion extrusion system. The sizing device is preferably adapted to unfold the pleats of a shirred casing stick while concurrently smoothing the wrinkles in the surface of that casing stick, both being accomplished as the casing material is moved over the surface contact areas of the sizing means. The sizing means is fully adjustable, while the casing material is moving over it, to either stretch and expand the material of the casing or to avoid stretching the material of the casing, depending on the desire of the food emulsion extrusion system operator. The means for sizing also provides the desired degree of hold back to the pay out of the casing material and is fully adjustable in respect to the degree of hold back applied while the casing material is moving over that sizing means. Adjustment to the sizing means may be accomplished at any time as the sizing means preferably includes remote adjustment means which are operable both while the casing is being stuffed and otherwise. Thus, detected variations in the casing material thickness and composition, as well as variations in the perimeter size of the casing material, may be compensated for immediately as the casing material is being stuffed by the food emulsion extrusion system. In addition, variations in the composition of the food emulsion itself may be likewise compensated for during the stuffing of the casing by the food emulsion extrusion system.
Primarily, the sizing means is designed to permit the shirring of casing material as it is telescoped over the stuffing horn, using unshirred casing material paid out from, for example, rolls of continuous, flattened casing material. The casing material is projected onto and over the stuffing horn by means known to those with skill in the art.
Further, the sizing means may be adapted to permit the sheathing or telescoping of an unshirred casing material over the sizing means and onto the stuffing horn of the food emulsion extrusion system, without disassembly or removal of the sizing means or any part or portion of it, thus permitting the use of known automated, on-site casing shirring equipment in combination with the food emulsion extrusion system. Advantageously, the sizing means of the present invention is preferably adapted to be mounted onto and over a standard stuffing horn of a food emulsion extrusion system without modification or change to that stuffing horn. On the other hand, the sizing means of the present invention may be readily adapted to other means for stuffing as will be well understood by those with skill in the art.
Adjustment to the sizing means of the present invention may be accomplished manually by the operator of the food emulsion extrusion system or may be accomplished, at the other extreme, by a fully automated and computerized detection and closed loop feed back system adapted to operate mechanized means for adjustment of the sizing means; of course, any degree, style, type or design of automation and/or mechanization to such adjustment means, within the understanding of those with skill in the art, are included within the scope of the present invention. The adjustment means of the present invention is preferably adapted to permit the use of different codes or sizes of casing without change of the sizing means provided the internal bore of the unshirred casing material is sufficiently large enough to permit the sheathing or telescoping of that material over the sizing means. The present invention is readily adapted to be applied to the production of a full range of sizes of stuffed and encased food emulsion products, for example, a range of products from the smallest being, e.g., Vienna sausage and the like, to the largest being, e.g., bologna and similar sized products. The present invention is also adapted to be used with a full range of casing materials including those which are natural and those which are synthetic, those which are edible and those which are nonedible. The present invention may be readily used with unshirred casing materials without adaptation, and it could be adapted to be used with pre-shirred casing sticks.
In the preferred embodiment of the present invention, the adjustment means comprises a tube which is sheathed or telescoped over and onto the stuffing horn of a food emulsion extrusion system. The tube predominantly encases the stuffing horn but is preferably not as long as the stuffing horn itself. At the input end of the stuffing horn, i.e., that end which is mounted to the food emulsion pump of the extrusion system, there is a bearing means, for example, a Teflon® PTFE ring which is fitted over the stuffing horn and slid along its length to abut against the food emulsion pump. Next, the tube of the adjusting means is telescoped over the length of the stuffing horn into abutment with the bearing means. Then, positioning means are fitted over the output end of the stuffing horn and slid back against the end of the tube of the adjusting means. The positioning means are then fixed to the food emulsion stuffing horn with sufficient clearance to permit the rotation of the adjustment means about the longitudinal axis of the stuffing horn.
In the preferred embodiment, the positioning means are fixed stationarily to the stuffing horn such that such means do not rotate, but however are removable for cleaning, etc., as, for example, by use of a set screw means. Interposed between the adjustment means and the positioning means are preferably a plurality of sizing heads. At least one of these sizing heads is fixed to the positioning means and remains stationary. Another of the sizing heads is preferably mounted in fixed position to the end of the adjustment means and moves with rotation of the adjustment means about the stuffing horn. Additional movable sizing heads may be interposed as will be hereinafter explained.
The sizing heads are preferably adjustable such that in their fully retracted position, a length of unshirred casing material may be sheathed or telescoped over them with sufficient clearance in between to result in a loose fit. On the other hand, the sizing heads are preferably adjustable in their extended position such that they are adapted to fully expand the casing material to its full unshirred perimeter dimensions or somewhat beyond by stretching the casing material. Thus the degree of frictional contact and force imposed by the sizing means on the interior walls of the casing material is preferably fully adjustable providing both expansion of the casing material, stretching it if desired, and fully adjustable hold back force to the pay out of the casing material from the output end of the stuffing horn. If desired, the sizing means of the present invention may be designed, in length, such that sufficient length of the stuffing horn extends therebeyond to mount a conventional brake device (a device which imposes force to the exterior walls of the moving casing material).
Accordingly, it is a principal object of the invention to provide an improved food stuffing apparatus for tubular food casings. The apparatus includes:
(a) a food casing filling horn means with a food inlet end, a food outlet end and a cylindrical shaft intermediate to the inlet and outlet ends. As with most food casing filling machines, the improved apparatus includes pump means for extruding a foodstuff through the food casing filling horn means; and
(b) the above elements are used in combination with a stationary food casing sizing means and an independently adjustable food casing sizing means telescoped over the cylindrical shaft of the food casing filling horn for expansion of unfilled casing loaded on the filling horn. Both the stationary food casing sizing means and the adjustable food casing sizing means have means for engaging and peripherally expanding the food casing. Only movement of the adjustable food casing sizing means being required in order for both the stationary and adjustable food casing sizing means to engage and expand the casing immediately prior to being filled.
It is a further object of the invention to provide for an improved stuffing apparatus which incorporates novel sizing heads which can be circular in shape and eccentrically mounted in a plane which is transverse to the longitudinal axis of the food casing stuffing horn. Alternatively, the invention contemplates sizing heads for engaging and expanding tubular food casing on the stuffing horn which are generally oblong in shape.
It is yet a further object to provide such a filling apparatus in combination with means for shirring casing directly onto the filling horn without disassembly or removal of the sizing device.
A still further principal object is to provide for a method of stuffing tubular food casing by the steps of:
(a) providing a stuffing apparatus for tubular food casing comprising a filling horn, pump means for extruding a foodstuff through the filling horn, a stationary casing sizer head and an adjustable casing sizer head. The casing sizer heads are telescoped over the filling horn and positioned transverse to the longitudinal axis of the filling horn;
(b) rotating the adjustable casing sizer head to substantially align it with the stationary sizer head;
(c) loading a tubular food casing onto the filling horn and over the casing sizer heads without disassembly or removal, and
(d) rotating the adjustable casing sizer head sufficiently for both the stationary sizer head and adjustable casing sizer head to engage and peripherally expand the casing on the filling horn as a foodstuff is extruded into the casing to withdraw empty casing from the filling horn.
These and other features of the sizing means of the present invention will be more fully explained and disclosed in greater detail by the accompanying drawings and the following detailed description of the preferred embodiment. As will be well understood by those with skill in the art, the sizing means of the present invention may readily be adapted to the packaging of many other substances, foodstuff as well as materials which are not foods. Thus, the description herein in relation to food emulsion products is intended to be exemplary and is not intended to be a limitation regarding application of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 an exploded side elevational view of the sizing means of the present invention as it relates to a conventional stuffing horn of a food emulsion extrusion system.
FIG. 2 is a side elevational view of the sizing means of the present invention showing the assembly of the elements shown in FIG. 1.
FIG. 3 is a front elevational view, in cut-away, as shown from position III--III of FIG. 2.
FIG. 4 is a front elevational view, in cut-away, as viewed from position IV--IV of FIG. 2.
FIG. 5 is a front elevational view of the sizing means of the present invention in its fully retracted position as shown from view V--V of FIG. 2.
FIG. 6 is a front elevational view of the sizing means of the present invention as viewed from the position of VI--VI of FIG. 7.
FIG. 7 is a side elevational view of the sizing means of the present invention in its fully extended position as viewed from position VII--VII of FIG. 6.
FIG. 8 is a front elevational view of a first alternate embodiment of the sizing means of the present invention as shown in its fully extended position.
FIG. 9 is a front elevational view of a second alternate embodiment of the sizing means of the present invention shown in its fully extended position.
FIG. 10 is a side elevational view of a section of the sizing means of the second alternate embodiment of the present invention in its fully extended position as shown by a view from position X--X of FIG. 9.
FIG. 11 is a side elevational view of the sizing means of the present invention as shown in FIG. 2, but with the addition of a schematic representation of means for shirring the flattened casing material as it is telescoped onto the stuffing horn over the sizing means.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 there is shown a stuffing horn 11 mounted to a conventional meat pump 13. The stuffing horn 11 is in the form of a tube with an internal bore 15 extending therethrough into meat pump 13. Telescoped onto stuffing horn 11, from the output end 17 to the input end 19, is bearing means 21. Bearing means 21 may simply be in the form of a truncated cylindrical section of a Teflon® PTFE tube. The function of bearing means 21 is to provide thrust support for other elements of the sizing means of the present invention as will be further explained hereinafter; bearing means 21 also serves to space apart the other elements of the sizing means of the present invention from meat pump 13, providing a readily replaceable wear surface for the other elements of the sizing means of the present invention as will be further explained hereinafter.
Continuing with reference to FIG. 1, there is shown adjustment means 23. Adjustment means 23 preferably comprises an adjustment tube 25 which is an elongated cylindrical section with its inside diameter 27 sized to permit adjustment tube 25 and the balance of adjustment means 23 to be readily fitted over output end 17 of stuffing horn 11 and slid thereonto and telescoped therealong to the point of contact between adjustment means 23 and bearing means 21.
At the lead end 29 of adjustment tube 25, there is located bearing flange 31. Bearing flange 31 is fixed to the lead end 29 of adjustment tube 25, bearing flange 31 being that element of adjustment means 23 which comes into face-to-face contact with bearing means 21. Opposite to lead end 29 is trailing end 33 of adjustment tube 25. Removably fixed to trailing end 33 of adjustment tube 25 is adjustable sizing head 35.
Adjustable sizing head 35 is preferably removably fixed to trailing end 33 by, for example, recessed cap screws 37 extending through mounting apertures 39 in adjustable sizing head 35. Recessed cap screws 37 are threaded into bolt blocks 41 which may be permanently fixed to the exterior surface of adjustment tube 25 adjacent to trailing end 33 about as shown in FIG. 1. For example, bolt blocks 41 may be welded or brazed to adjustment tube 25 if adjustment tube 25 is made of a metal. Alternatively, bolt blocks 41 may be formed as an integral part of adjustment tube 25, for example, if adjustment tube 25 is made of a plastic material.
As will be well understood by those with skill in the art, bolt blocks 41 may be attached to adjustment tube 25 by a wide variety of well known different methods. Likewise, adjustable sizing head 35 may be mounted to and/or fixed to the trailing end 33 of adjustment tube 25 by any one of a variety of different well known methods as will be well understood by those with skill in the art. Adjustable sizing head 35 may be removable, for example, in the situation where adjustment tube 25 is made of metal and likewise, for example, adjustable sizing head 35 is made of metal also. Alternatively, for example, adjustable sizing head 35 could be made integral with adjustment tube 25 (as might be the case where all plastic material is utilized) as will be well understood by those with skill in the art. Preferably, adjustment means 23 is made from stainless steel although alternatively it could be made from any one of a wide variety of different metals or plastics or combinations of metals and plastics vis-a-vis the assembly of various elements of adjustment means 23.
Also shown in FIG. 1 is stationary sizing fixture 43 which preferably comprises fixed collar 45, in the form of a truncated cylindrical section, to which is mounted stationary sizing head 47. Fixed collar 45 is mounted to stuffing horn 11 and removably fixed thereto by, for example, hex-head set screw 49 which extends radially through fixed collar 45 in threaded engagement therewith, as will be well understood with those with skill in the art. The internal aperture 51 of fixed collar 45 is preferably sized the same as the inside diameter 27 of adjustment tube 25, both being sized to permit fixed collar 45 to be readily fitted over the output end 17 of stuffing horn 11 and slid therealong. Stuffing horn 11 extends through fixed collar 45 and beyond to provide a mount for a conventional braking device (not shown), if desired, and to provide a mount for casing expansion collar 75 as will hereinafter be explained in reference to FIG. 11.
Further, as shown in FIG. 1, adjacent to lead end 29 of adjustment tube 25 is positioned means for rotating 53 which functions to exert rotational pressure onto adjustment means 23, thus enabling the repositioning of adjustment means 23 circumferentially around stuffing horn 11. In its simplest form as shown in FIG. 1, rotational means 53 is comprised, for example, of handle 55 which extends tangentially from the diameter of adjustment tube 25 and handle mount 57. In the example shown in FIG. 1, handle 55 is mounted to handle mount 57 which in turn is fixed to the exterior surface of adjustment tube 25 as will be well understood by those with skill in the art by reading the following explanation and description. Handle 55 could be attached to adjustment tube 25 by any one of a number of different well known methods.
The tangential positioning of handle 55 in relation to the diameter of adjustment tube 25 is only one of a number of different positions that could be assumed by handle 55. For example, handle 55 could extend radially outward from adjustment tube 25, the only requirement being that force applied to handle 55, in a circumferential direction perpendicular to the longitudinal axis of adjustment tube 25, causes the rotational movement of adjustment tube 25 about its longitudinal axis. Handle mount 57 is optional and is merely shown to provide an exemplification of means to strengthen the attachment of handle 55 to adjustment tube 25 as will be well understood by those with skill in the art. Handle 55 and handle mount 57 may be fixed to adjustment tube 25 in the preferred embodiment, wherein the elements of adjustment means 23 are made of stainless steel, by, for example, welding. Alternately, handle 55 might be, for example, bolted to handle mount 57 as will be well understood by those with skill in the art.
The assembly of the elements of the sizing means of the present invention are shown in FIG. 2. As can be seen from viewing FIG. 2, bearing flange 31 is in face-to-face contact with bearing means 21 in a relationship which will be well understood by those with skill in the art as a thrust bearing relationship. Bearing means 21 may be stationary or it may be rotatable, such as might be found when using a ball or roller type thrust bearing. In the preferred embodiment, where a Teflon® PTFE ring is used, bearing means 21 would preferably be stationary, although occasional rotation thereof in relation to meat pump 13 will cause no difficulty, problem or harm.
Also, as shown in FIG. 2, adjustable sizing head 35 and stationary sizing head 47 are in face-to-face relationship. In the assembly of the sizing means of the present invention, as mounted on stuffing horn 11, bearing means 21, adjustment means 23 and stationary sizing fixture 43 are all axially aligned with the axis of stuffing horn 11 and are all coaxial therewith.
FIG. 3 shows a front view of the sizing means of the present invention in cut-away as viewed from the position of III--III in FIG. 2. As can be readily seen from viewing FIG. 3, the radial center point of adjustable sizing head 35 is offset from the radial center point of adjustment tube 25 and stuffing horn 11. However, the axis of rotation of adjustable sizing head 35 is still maintained as the axis of rotation of adjustment tube 25, and both are coincident to and coaxial with the longitudinal axis of stuffing horn 11.
As will be recognized by viewing FIG. 3 because the axis of rotation of adjustable sizing head is eccentric, as handle 55 is rotated in the direction of the arrow extending to the right, away from handle 55, contact surface 59 of adjustable sizing head 5 will be rotated in an arc which describes a circumferential path having a radius which extends from the axis of rotation of adjustment tube 25 to contact surface 59. As will also be noted from viewing FIG. 3, the distance from the axis of rotation of adjustment tube 25 to a point on adjustable sizing head 35 which is directly opposite from contact surface 59, is substantially less than the radius which extends from that axis of rotation of adjustment tube 25 to contact surface 59 as a result of its eccentric axis. Thus, the circumferential path described from that opposite point will be substantially less in diameter than for the diameter associated with the circumferential path described by contact surface 59.
FIG. 4 is a cut-away view from the front as viewed from position IV--IV of FIG. 2. FIG. 4 shows handle 55 attached to handle mount 57 which, in turn, is attached to the wall of adjustment tube 25 as described previously. Bearing flange 31 is also shown in position against bearing means 21 which is not shown in FIG. 4 as it is behind bearing flange 31 in the view of FIG. 4. The positioning of adjustment tube 25, telescoped (sheathed) over stuffing horn 11, is clearly shown in FIG. 4. In the preferred operation of the sizing means of the present invention, stuffing horn 11 remains stationary, in position, while the movement of handle 55 in the direction shown by the arrow, extending from handle 55 in FIG. 4, causes rotation of adjustment tube 25 about stuffing horn 11. This rotation causes bearing flange 31 to rotate in face-to-face relationship against bearing means 21. As mentioned previously, handle mount 57 reinforces the attachment of handle 55 to the wall of adjustment tube 25.
Referring to FIG. 5, there is shown a front elevational view of the sizing means of the present invention as viewed from position V-V of FIG. 2. As can be seen from FIG. 5, set screw 49 extends radially through the wall of fixed collar 45, and thus set screw 49 can be tightened against stuffing horn 11 to lock stationary sizing fixture 43 in position in relation to stuffing horn 11. Also as shown in FIG. 5, stationary sizing head 14 is directly aligned with the position of adjustable sizing head 35 as shown in FIG. 3, thus, adjustable sizing head 35 cannot be seen in FIG. 5 but is directly behind stationary sizing head 47 in the view shown in FIG. 5.
In the preferred embodiment of the present invention, stationary sizing head 47 is identical in shape and size to adjustable sizing head 35, both of which are in the form of circular discs with eccentric axes of rotation. As mentioned previously, adjustable sizing head 35 rotates about the axis of rotation of adjustment tube 25, that axis of rotation of adjustment tube 25 being coincident and coaxial with the longitudinal axis of stuffing horn 11. On the other hand, stationary sizing head 47, being mounted to fixed collar 45, does not rotate, but rather remains in the position shown in FIG. 5. Rotation of handle 55, from the positions shown in FIGS. 3, 4 and 5 to the position shown in FIG. 6, a 180° arc of rotation, causes the rotation of adjustment tube 25 and consequently the rotation of adjustable sizing head 35 to the position as shown in FIG. 6.
The sizing means of the preferred embodiment of the present invention as shown in FIG. 5 is in the fully retracted position such that unshirred casing material, with an internal circumference at least as large as the circumference of stationary sizing head 47 (which is the same circumference as that of adjustable sizing head 35), may be readily fitted over that circumference with some degree of clearance therebetween.
Referring to FIG. 6, there is shown the fully extended position of the sizing means of the present invention. The peripheral distance extends, beginning from contact surface 59, around that circumferential surface portion of stationary sizing head 47 which extends beyond the circumferential surface of adjustable sizing head 35, and then likewise continues to extend around that portion of the extension of the circumferential surface of adjustable sizing head 35 which extends beyond that of stationary sizing head 47. Thus, a peripheral surface is inscribed which is substantially larger than that of the circumference of either stationary sizing head 47 or adjustable sizing head 35 taken individually. As shown in FIG. 6, contact surfaces 59 and 61 are now brought into engagement with the inside surface of a portion of tubular casing 63 (shown in FIG. 7) which has been deshirred from the shirred casing material which had been formed over the exterior surface of stationary sizing head 47 and adjustable sizing head 35 when in their retracted position as shown in FIG. 5. The formation of the shirred casing material will be further explained hereinafter in reference to FIG. 11. Thus, the peripheral distance inscribed, in relation to the fully extended positioning of the sizing means of the present invention as shown in FIG. 6, is sufficiently great enough to preferably be larger than the circumferential dimension of the inside surface of the fully extended, deshirred casing tube.
In the extended position shown in FIG. 6, contact surfaces 59 and 61 serve to expand, and if desired, to stretch the casing material as it traverses over those surfaces, in direct relation to the degree of extension of those contact surfaces 59 and 61. It will be understood by those with skill in the art that rotation of handle 55 from the position shown in FIG. 5 through a lesser arc than 180° (as shown in FIG. 6) will result in a lesser extension of adjustable sizing head 35, from the retracted position shown in FIG. 5, permitting the peripheral distance which inscribes contact surfaces 59 and 61 to be adjusted to any degree, from that of fully retracted as shown in FIG. 5 to that of fully extended as shown in FIG. 6. Thus, the degree of frictional contact between contact surfaces 59 and 61 and the inner surface of the tubular casing are infinitely adjustable up to a point of full expansion of the tubular casing or beyond to a stretched position, over-expanding the tubular casing by stretching it beyond its original interior circumference if desired.
Referring to FIG. 7, there is shown a side elevational view of the fully extended positioning of the sizing means of the present invention as viewed from position VII-VII of FIG. 6. Also shown in dotted line form is a representation of the extension of a tubular casing 63 being stretched over contact surfaces 59 and 61. Note, in the view of FIG. 7, that stationary sizing head 47 remains in the same position as is shown in FIGS. 2, 5 and 6, while adjustable sizing head 35 now extends downwardly opposite from the position shown in FIGS. 2 and 3 to the position shown in FIG. 6. Also note in FIG. 7 that handle 55 is shown as extending upwardly, opposite to the position that is shown in FIGS. 2-5; this is because handle 55 has been rotated 180° as shown in comparing FIGS. 5 and 6. As will be understood by those with skill in the art, all of adjustment means 23 has been rotated 180° from the position shown in FIG. 2 to that shown in FIG. 7. It is to be understood that adjustment means 23, in the preferred embodiment, comprises adjustment tube 25, bearing flange 31, adjustable sizing head 35, recessed cap screws 37, bolt blocks 41, handle 55 and handle mount 57.
Referring to FIG. 8, there is shown an alternate embodiment of the sizing means of the present invention. In the embodiment shown in FIG. 8, adjustable sizing head 65 is in the form of a modified diamond with the tips of the diamonds being rounded off. Likewise, stationary sizing head 67 is in the same form of a modified diamond with the tips of the diamond being rounded off. All other elements are identical to those described before in relation to FIGS. 1-7. In FIG. 8, as will be well understood by those with skill in the art, adjustment means 23 need only be rotated 90° to achieve full extension of contact surfaces 59 and 61. In the embodiment shown in FIG. 8, there are four contact surfaces: 59, 59', 61 and 61', yet the area engaged by each of those surfaces is substantially reduced due to a smaller radius for the rounded off points of the diamonds in comparison to the circular surfaces of stationary sizing head 47 and adjustable sizing head 35. The embodiment shown in FIG. 8 is particularly adapted to use with casings made of water soaked reconstituted cellulose such as might be employed, for example, in the production of, frankfurters.
Yet another alternate embodiment of the present invention is shown in FIG. 9. This second alternate embodiment is a variation on the first alternate embodiment shown in FIG. 8. In FIG. 9 there is shown adjustable sizing head 65 and stationary sizing head 67. In addition, variable sizing head 69 is added. Variable sizing head 69 is identical in size and form to that of the rounded off diamond form of adjustable sizing head and stationary sizing head 67 as shown in FIGS. 8, 9 and 10. Variable sizing head 69, in the position shown in both FIGS. 9 and 10, is locked to stationary sizing head 67 using hex-head lock screws 71 as will be well understood by those with skill in the art. The embodiment shown in FIG. 9 provides a total of six contact surfaces 59, 59', 61, 61', 73 and 73' which engage the interior surface of the tubular casing wall. Loosening off hexhead lock screws 71 permits the rotation of variable sizing head 69, independently of either stationary sizing head 67 or adjustable sizing head 65, such that variable sizing head 69 can be aligned with stationary sizing head 67, for example, to enable a shirred casing stick to be sheathed thereover. Rotation of adjustment means 23, in turn, causes adjustable sizing head 65 to be aligned with stationary sizing head 67, thus, resulting in the full retraction of the sizing means of the second alternate embodiment shown in FIGS. 9 and 10.
Once the casing material has been fitted over the second alternate embodiment of the sizing means shown in FIGS. 9 and 10, that casing material being shirred in the process as will be further explained hereinafter in reference to FIG. 11, variable sizing head 69 is rotated 60° and hex-head lock screws 71 are set in place, thus locking variable sizing head 69 to stationary sizing head 67 as mentioned above. A portion of the shirred casing material is unshirred and the tubular section thereof is extended across the second alternate embodiment of the sizing means shown in FIGS. 9 and 10. Then, adjustment means 23 is rotated to any degree up to 60° to provide the degree of frictional contact that is desired, even to the extent of stretching the circumference of the tubular casing section as it traverses the extended position of adjustable sizing head 65, stationary sizing head 67 and variable sizing head 69. The contact surfaces 59, 59', 61, 61', 73 and 73' of the embodiment shown in FIGS. 9 and 10 are those portions of adjustable sizing head 65, stationary sizing head 67 and variable sizing head 69, respectively, which engage the interior surface of the tubular casing.
As will be understood by those with skill in the art, it is possible to likewise make variable sizing head 69 infinitely adjustable in the same manner that adjustable sizing head 65 is infinitely adjustable. This could be done by interposing a second adjustment tube between adjustment tube 25 and stuffing horn 11 such that variable sizing head 69 could be adjusted in the same manner that adjustable head 65 is adjusted by rotation of adjustment tube 25.
Means for shirring the tubular casing 63 onto the stuffing horn are shown in FIG. 11 comprising a casing expansion collar 75 which is fitted over the output end 17 of stuffing horn 11 and preferably positioned in a spaced apart relationship to fixed collar 45, although casing expansion collar 75 could abut fixed collar 45 in a face-to-face relationship as will be understood by those with skill in the art. Casing expansion collar 75 is preferably in the form at a truncated cylindrical section having a bore therethrough which extends parallel to the axis of rotation at that cylindrical section but which is offset therefrom to the same extent that the radial center point of adjustable sizing head 35 is offset from the radial center point of adjustment tube 25 as was explained above in reference to FIG. 3. Casing expansion collar 75 is somewhat larger in diameter than either adjustable sizing head 35 or stationary sizing head 47. Thus, tubular casing 63 which is sheathed over casing expansion collar 75 has sufficient clearance to be easily sheathed over both adjustable sizing head 35 and stationary sizing head 47 when in the fully retracted position as shown in FIG. 5.
The function of casing expansion collar 75 is to open up tubular casing material 63 from a flattened posture to the form of a hollow cylindrical section as tubular casing 63 is sheathed (telescoped) over casing expansion collar 75. Also, casing expansion collar 75 provides backup support for shirring rollers 77 which drive the outer surface of tubular casing 63 over casing expansion collar 75 and onto the sizing means of the present invention as shown in FIG. 11.
Shirring rollers 77 are formed preferably from a resilient material, for example, a urethane elastomer or a synthetic rubber such as neoprene. The axes of rotation of shirring rollers 77 are perpendicular to the axis of rotation of casing expansion collar 75. Shirring rollers 77 are sized and positioned such that they will frictionally be in contact with the outside surface of tubular casing 63 as it passes over casing expansion collar 75; thus, rotation of shirring rollers 77 serves to drive tubular casing 63 over casing expansion collar 75, telescoping tubular casing 63 over both the sizing means of the present invention and stuffing horn 11. Shirring rollers 77 are mounted on power driver shafts 79 which cause shirring rollers 77 to rotate in frictional contact with the outer surface of tubular casing 63. The inner surface of tubular casing 63 slides across the smooth outer surface of casing expansion collar 75.
Tubular casing 63, initially, is in a flattened form being packaged on a reel 81 which is suspended on mandrel 83 which is free to rotate. The rotation of shirring roller 77 by power driver shafts 79 causes tubular casing 63 to pay out from reel 81. Initially, the end of tubular casing 63 is fed, usually manually, over casing expansion collar 75 where it is engaged by shirring rollers 77 which feed tubular casing 63 over the sizing means of the present invention and stuffing horn 11. The end of tubular casing 63, as so fed, comes into contact with casing stop 85 which, for example, may be a ring mounted to adjustment tube 25 at a location which is adjacent to handle 55 and handle mount 57 as shown in FIG. 11. As will be well understood by those with skill in the art, casing stop 85 may readily take a variety of different forms. Likewise, casing stop 85 could be integral with handle 55 or handle mount 57 or both.
As tubular casing 63 comes into casing stop 85, it begins to, and continues, to bunch up, taking the form of accordion pleating. Thus the tubular casing 63 is shirred as shown in FIG. 11, allowing, for example, as much as 100 feet or more of the tubular casing 63 to be shirred onto the relatively short length of the sizing means of the present invention and the stuffing horn 11.
While FIG. 11 shows a reel 81 of flattened tubular casing suspended on a mandrel, it will be understood that such casing may also be folded in a carton container (not shown) for payout to the shirring mechanism, previously described.
Regardless of whether flattened casing 63 is supplied from a continuous reel or in folded form from a carton, the apparatus of FIG. 11 also contemplates casing feed, lock and adjustment means of known design (not shown) positioned between reel 81 and shirring rollers 77 to assist in withdrawing a predetermined length of flattened casing from the casing supply source for delivery to the stuffing horn for shirring in the manner previously described.
The system for delivery of casing to the stuffing horn also advantageously includes a reciprocating casing carrier for transporting the terminal end section of a new length of casing from the supply source to stuffing horn 11 for shirring. Suitable representative feed, lock and casing carrier apparatus for withdrawing and transporting lengths of casing to the stuffing horn are disclosed in detail by U.S. Pat. No. 3,919,739, and particularly U.S. Pat. No. 4,534,084, the disclosures of which are incorporated by reference herein.
Although the preferred and alternate embodiments of the present invention have been described in considerable detail, it will be apparent to those skilled in the art that those preferred and alternate embodiments of the present invention are capable of numerous modifications, variations and combinations without departing from the concepts, spirit and scope of the present invention as defined by the appended claims which are hereby specifically included, by this reference, in the foregoing specification. | Casing material is paid out from the stuffing horn of a food emulsion extrusion system to stuff a food emulsion product. The casing material is drawn over a sizing means which provides varying degrees of sizing and hold back force to the casing material as it is paid out. The degrees of sizing and hold back force are adjustable while the casing is being stuffed with extruded food emulsion. New casing material may be loaded onto the stuffing horn over the sizing means without removal of any element of the sizing means from the stuffing horn. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to pole grasping-type climbers utilizing paired grasping structures, and more particularly, to paired tree climbing members which are worn on the feet to be alternately raised by the user to attain a desired elevation on a vertical member such as a pole, a tree trunk or the like.
2. Description of the Prior Art
According to the prior art, a variety of tree stands or climbers have become available commercially to serve as, for instance, elevated hunting platforms or work platforms for gaining access to elevated structures. One variety of tree climber comprises upper and lower climbing frames. Tree climbers of this variety described in U.S. Pat. No. 4,331,216 to the present inventor typically are comprised of paired grasping structures, each structure being moved independently of the other in a step-wise fashion to attain the desired elevation on the vertical member.
Typical of such conventional tree stands is the widespread use of bolted connections which must be properly completed and/or adjusted prior to use. Such connections and adjustments often prove time consuming and cumbersome, especially in the dark, and require the user to carry wrenches or similar tools into the field. According to some designs, a two-person assembly team is virtually a necessity in completing such installation.
Another problem with tree climbers of the prior art is the restrictive closed frame structure which encircles the tree or pole. Unless the tree is of a relatively uniform cross-section (not likely), protruding limbs of excessive length or other oversized outcroppings will prevent further vertical progress, or at least make it difficult to navigate around the obstruction. One solution to this problem is addressed in U.S. Pat. No. 4,225,013, the apparatus of which includes a pair of C-shaped arcuate clamping members which partially encircle the tree. In use, branches and other protrusions are passed through the open portion of the arcuate clamping members as the climber ascends and descends the tree. These C-shaped openings, however, will accommodate only those trees sized within a limited range of diameters. Another problem with this apparatus is the absence of the rigidity offered by various closed-frame designs.
Yet another problem with prior art devices is their relatively cumbersome bulk, even in their collapsed condition, which hinders transportability especially over heavily wooded terrain.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a tree or pole climbing device which is readily assembled, even in darkness, and which is easily adjusted, both during and after installation about the pole, tree trunk, or other similar vertical member, and during removal therefrom, such assembly, adjustment, and removal readily accomplished by a single person.
It is another object of the present invention to provide a tree or pole climbing device which can readily accommodate and operate on vertical members having a relatively wide range of diameters.
It is a further object of the present invention to provide a tree or pole climbing device which can easily traverse those protruding limbs of excessive length and other oversized outcroppings extending from the vertical member which otherwise hinder vertical access by the user.
It is yet another object of the present invention to provide a tree or pole climbing device which offers a relatively rigid structure while affixed to the vertical member and which safely secures the climber to the vertical member.
A further object of the present invention is to provide a climbing stand having relatively compact dimensions when in the collapsed condition, and which is easily transportable by a single person.
A still another object of the present invention is to provide a safety strap which is engaged with the climbing device and with the tree or pole to add further security to the user. These and other objects are achieved in the present invention which includes two climbing members which are attached to the climbing feet and alternately raised in a stepwise fashion while ascending or descending the tree to attain the desired elevation. Each foot climbing member includes a platform portion and a clamping portion. The platform portion is affixed to the user's feet by a set of quick release straps. A support arm extends forward from each platform portion and terminates at a clamping portion rigidly attached thereto. The clamping portion has a hook or bow-like shape with its concave side directed back toward the platform portion. Teeth-like protrusions are integrally formed within the concave side and engage with the back side of the tree pole. The forward-most edge of the platform may also include said teeth-like protrusions for engaging with the front side of the tree pole. The climbing members are constructed to be mirror images of each other to be respectively worn on the right and left feet of the user.
One end of the clamping portion is releasably affixed to the support arm. In a like manner, the support arm is releasably affixed to the platform portion. According to the invention and its various embodiments, the clamping portion is adjustable relative to the platform portion so as to accommodate vertical members having a wide range of diameters. According to one embodiment, a flanged end of the clamping portion is releasably engaged with the channel of the support arm and secured thereto at any of a selection of engagement points arrayed along in the support arm by a spring-tensioned locking pin passing through and securing together both elements. According to a second embodiment, the end of the clamping portion is affixed to a collar through which a tubular support arm slidably extends. A spring-tensioned or other quick-release locking pin is passed through overlapping engagement holes in both members to secure them together.
A third embodiment of the present invention replaces the spring-tensioned locking pin of the first embodiment with a knurl-ended bolt which secures the flange of the clamping portion to the support arm. According to any one of the first three embodiments, the support arm extends out of the plane of the platform portion at a predetermined angle, the support arm collapsing against the platform portion during transport. According to a fourth embodiment, the platform end of the support arm telescopes through a collar which is rigidly affixed to an upturned edge of the platform portion. The support arm of this embodiment is longitudinally fixed within the collar at any one of an array of spaced-apart engagement holes disposed in the support arm through which a spring-tensioned locking pin, knurl-ended bolt or the like is passed to secure together the two elements.
After the climbing members have been vertically moved by the user in stepwise fashion to the desired elevation the top climbing member, and each of the climbing members is then secured to the tree by a strap lock referred to as an "Am-Lock" strap. The Am-Lock strap includes two hooks securely fixed to the opposite ends of a sturdy strap and a tensioning device affixed intermediate the hooks. The strap is wrapped about the diameter of the vertical member and the hooks are affixed to opposite ends of the climbing member. Optionally, notches may be formed into the hook portion or the climbing member to accommodate the hooks. The tensioning device is then operated to bring the strap into a tightened embracing relationship with the vertical member and the clamping portion.
Adjustable backpack-style carrying straps are attached to the platform portion to enable transportability. When not in use, the straps are folded and stored within recesses formed in insulative seat cushion material layered on the platform portion.
With the foregoing and other objects, advantages and features of the invention that will become hereinafter apparent, the nature of the invention may be more clearly understood by reference to the following detailed description of the invention, the appended claims and to the several views illustrated in the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial view of the tree climbing members of the present invention shown mounted in a tree and supporting a hunter;
FIG. 2 is a top plan view of one of the paired climbing members of the first embodiment of the invention, said climbing member, worn on the right foot of the user;
FIG. 2A is a pictorial view of the Am-Lock strap shown in FIG. 2 in a detached condition from the clamping portion of the climbing member, illustrating additional details of the strap;
FIG. 3 is a bottom plan view of the climbing member of the embodiment shown in FIG. 2;
FIG. 4 is an enlarged side view of FIG. 3, partially in cross-section, of the spring-tensioned locking member in an engaged position and securing together the clamping member and support arm of one embodiment of the invention;
FIG. 5 is a fragmentary view of FIG. 4, showing the spring-tensioned locking pin in a withdrawn, disengaged position;
FIG. 6 is an enlarged, fragmentary, cross-sectional view of the platform portion of the climbing member shown in FIG. 2, showing the platform and seat cushion material;
FIG. 7 is a perspective view of the engaged clamping portion and support arm of a second embodiment of the invention;
FIG. 8 is a perspective, partially exploded, view of the engaged clamping portion and support arm of a third embodiment of the invention;
FIG. 9 is a perspective, partially exploded, fragmentary view of the angularly adjustable support arm of any of the first three embodiments engaged with an upturned edge of the platform portion;
FIG. 1O is a perspective view of the paired climbing members of a fourth embodiment of the invention;
FIG. 11 is a top plan view of a right-foot climbing member of the fourth embodiment of the invention, in its mounted position about a vertical member such as a tree trunk;
FIG. 12 a side view of FIG. 11, partly in cross-section, showing the preferred mounted position;
FIG. 13 a top plan view of a right-foot climbing member of the first embodiment of the invention, further showing the carrying straps positioned for transport;
FIG. 14 is a side view, partly in cross-section, of the carrying straps and climbing member shown in FIG. 13.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now in detail to the drawings wherein like parts are designated by like reference numerals throughout, there is illustrated in FIG. 1 a pictorial view of the climbing stand of the present invention mounted in a tree and supporting a hunter, the tree climbing stand designated generally by reference numeral 10. The climbing stand 10 comprises a pair of left and right members, each of which is designated generally by reference numeral 20.
Now referring to FIG. 2, each climbing member 20 made in accordance with this invention includes an elongated platform portion 22 constructed preferably of a sturdy metal such as sheet steel or aluminum. The platform portion 22 includes a forward end 24, a back end 26, and is framed along its length by a pair of substantially parallel edges 28,30. An upturned edge 32 integrally formed with the platform portion 22 is disposed along the outer parallel edge 30 of a right climber member 20 worn on the user's right foot. In like manner, an upturned edge 32 is integrally formed with the platform portion 22 of a left climber member, said upturned edge 32 disposed along a corresponding outer parallel edge 28 of the platform portion 22. The platform portion 22 is affixed to the user's foot by two paired sets of quick release strap means 34. The strap means 34 comprise a tongue end 36 disposed on one of each pair of strap means 34, said tongue end 36 adjustably engagable with a cinch-type fastening means or buckle 38 disposed on each of the corresponding strap means 34 of each pair.
Referring to FIG. 3, which is a bottom view of the climbing apparatus shown in FIG. 2, the strap means 34 are shown securely fastened to the platform portion 22 with a bolted connection 35 passing therethrough.
A flange 41 of the support arm 40 is disposed parallel to the upturned edge 32 of the platform portion 22. A back end 42 of the arm 40 is affixed to the upturned edge 32 by a bolted connection 44 which enables the arm 40 to swivel out of the plane of the platform portion 22 as will be further described. The forward end 46 of the support arm 40 extends beyond the forward end 24 of the platform portion 22. A plurality of spaced attachment holes 47 are disposed along the length of the support arm 40 to accommodate the varying diameter of poles encountered during use.
A clamping portion or hook 48 is adjustably affixed to the extended support arm 40. The clamping portion 48, which is constructed of a relatively stiff and strong metal such as steel, has a bow-like shape with its concave side directed back to the platform portion 22 when one end 50 of the clamping portion 48 is affixed to the support arm 40. An array of teeth-like protrusions 51 are integrally formed along the forward edge 24 of the platform portion 22 to securely engage with the pole. Optionally, another array of such protrusions (not shown) are integrally formed along the concave side of the clamping portion 48. In those instances where it is desirable to protect the tree from injury by a conventional protective sheath having protrusions 51, a U-shaped cross-section (not shown) made of a non-skid material such as an elastomer may be removably positioned over the protrusions 51.
Referring now to FIGS. 2-5, in one of the preferred embodiments the clamping portion end 50 includes a flange 52 with an L-shaped cross-section which is slidably engaged with a corresponding channel 54 disposed in the support arm 40. The clamping portion end 50 is slidably adjustable along the length of the support arm 40. After the climbing member 10 has been adjusted about the tree member (not shown) such that the forward end 24 of the platform portion 22 and the clamping portion 48 are in simultaneous contact with the tree, the clamping portion 48 is engaged with the support arm 40 at the appropriate one of the attachment point recesses 47 with a quick-release spring-tensioned locking device 56. Locking device 56 which is also described in my concurrently filed patent application entitled "Automatically Adjustable Tree Climbing Stand" and is incorporated herein by reference, includes an engagement pin 58 which is biased into engagement by a spring 60, causing projection of the pin 58 into the overlapped engagement recesses 47 of the support arm channel 54 and clamping portion flange 52, as shown in FIG. 4. To disengage the engagement pin 56 from the openings 47 for purposes of adjustment, disassembly, or maintenance, a pull ring 62 affixed to the opposite end of the pin 56 is grasped and pulled to slidably withdraw the pin 56 from said recesses 47.
Referring to FIGS. 1-3, 15, after the user has reached the desired elevation, each of the climbing members 20 are secured thereto by a strapping system called the "Am-Lock" strap available from Amacker International, Inc. of Delhi, La. As shown in FIG. 15, the Am-Lock strap includes two hook means 70 disposed at opposite ends of a bifurcated strap 72. A tensioning device 74 joins together the bifurcated ends 76 of the strap 72 at an intermediate location thereof.
Additional details of the Am-Lock strap are shown in FIG. 2A which illustrates the strap in a detached condition from the clamping portion 48 of the climbing member 20. Each hook means 70 is comprised of a single length of metal rod 70a which is formed into a doubled-over structure having an eyelet 70b at one end and paired opposite ends 70c formed into C-shaped or L-shaped hooks. The eyelet 70b of each hook means 70 engages with a strap end 72a passing therethrough.
The tensioning device 74 is comprised of a ladder-type buckle 74a having a plurality of crossbars 74b. A lever 74c is rotatably affixed to an inboard crossbar 74b. Laterally extending protrusions 74d disposed on the lever 74c engage with corresponding detents 74e disposed in the buckle 74a when the lever 74b is rotated into a locked position. The strap 72 is threaded in a serpentine manner into one end of the unlocked buckle 74a, between the crossbars 74b, about the lever 74c, and exits at the opposite end of the buckle 74a after passing around another crossbar 74b. When the lever 74c is rotated into the locked position, the strap 72 becomes firmly cinched within the buckle 74a. Tensioning adjustment is made by altering the length of strap 72 within the buckle 74a. Alternatively, a bifurcated strap (not shown) may be used, having one bifurcated end affixed to an outboard crossbar 74b, the other bifurcated end threaded into the tensioning device in the above-described manner from the opposite end of the buckle 74a. Tensioning adjustment is accomplished by extending or withdrawing the strap through the buckle 74a prior to locking.
In operation, the Am-Lock strap is straddled about the diameter of the pole 150 and each hook means 70 is engaged with opposite ends of the clamping member 48. Optionally, spaced notches 78 may be formed on the outside surface of the clamping member 48 to receive the hook means 70. The tensioning device 74 is then operated to bring the strap 7 into a tightened embracing relationship with the pole 150 and the clamping portion 48 to add an additional degree of rigidity and security to the climbing member 20. According to the invention, the Am-Lock strap may be similarly used in conjunction with any of the variety of commercially available tree stands or pole climbers having pole-embracing clamping members, including but not limited to those pole climbing devices having cross-bar, square-shaped, or arcuate-shaped clamping members.
Now referring to FIG. 6, an enlarged, fragmentary, cross-sectional view of the platform portion 22 of the climbing member 20 shown in FIG. 2 shows a foam cushion layer 80 placed on the platform 22. The cushion 80 is resilient, and protects the users feet while climbing and serves as a soft seat while waiting.
A second embodiment of the present invention is shown in FIG. 7. According to this embodiment, the flanged clamping or gripping end 50 of the first embodiment shown in FIGS. 2 and 3 is replaced with a rigid metal square collar 90 having a square shaped opening 92 through which a tubular support arm 94 having a corresponding cross-section extends. An engagement recess or hole 98 is disposed in the square collar 90. A plurality of engagement recesses or holes 100 is arrayed along the length of the support arm 94. A retention pin 96 is projected through the collar recess 98 and one of the overlapping support arm recesses 100, and secured thereto, to rigidly affix the support arm 94 at a desired extension relative to the collar 90, after adjustment of the support arm 94 along the direction of the arrow 102. An array of teeth-like protrusions 104 is arrayed along the concave side of the clamping member 48 for gripping the tree 150 at a chosen elevation.
A third embodiment of the present invention is shown in FIG. 8. According to this embodiment, the square collar 90 of the second embodiment shown in FIG. 7 is replaced with a planar flange element 106. At least two engagement recesses 108 are disposed through the element 106. The clamping member 48 of this embodiment is positioned longitudinally relative to the platform member (not shown) in the direction shown by arrow 110 such that the two engagement recesses 108 overlap two similarly spaced-apart engagement recesses 112 disposed through the support arm 94. A bolted connection utilizing a knurl-knob bolt 114 is projected through each of the overlapped recesses 108,112, the bolt end captured by a securing nut (not shown) affixed to an inner surface of the support arm 94. Alternatively, the support arm recesses 112 may be tapped such that the bolts 114 may be securely engaged therein. A protective U-shaped sheath 116 is shown installed along the concave side of the clamping portion 48 in the manner previously described to protect the tree from the teeth 51 shown in FIG. 7.
According to any of the three embodiments described above and shown in FIGS. 2-8, the support arm 40,94 is pivotable about the bolted connection 44 through the upturned edge 32 of the platform portion 22. The support arm 40,94 is pivoted to a desired angle, such as 30 degrees from the plane of the platform portion 22, to establish the necessary structural and geometrical relationship of the support arm 40 and its attached clamping member 48 with the pole, and also to orient the platform member 22 in a generally preferred horizontal position relative to the ground.
Now referring to FIG. 9, the support arm 40,94 is shown in an operative position after being reoriented along the direction of the arrow 47 from its collapsed position within the plane of the platform portion 22. Two angularly spaced apart engagement recesses or holes 43, relative to the pivoting connection 44, are disposed in the upturned edge 32 and selectively correspond with an overlapping recess 49 disposed in the support arm 40. A bolt 45 and wingnut 45' secures the support arm 40,94 either within or without the plane of the platform portion 22 in a collapsed or operative position, respectively, after the bolt 45 has been simultaneously projected through the corresponding engagement recesses 43,49.
A perspective view of a fourth embodiment of the present invention is shown in FIG. 10. The pivotable connection 44 of the first three embodiments previously described is replaced with a rigid metal square collar 120 having a corresponding shaped opening through which any of the support arms 40,94 may slidably extend. The collar 120 is rigidly affixed by a weld bead 122 to the upturned edge 32 of the platform portion 22, and extends angularly outwardly from the plane of the platform portion 22 at about a 30 degree angle. A lengthwise array of engagement recesses or holes 124 are disposed along the platform portion end of the support arm 40,94. An engagement recess 126 is disposed through the collar 120. After the support arm 40,94 has been extended a desired length through the collar 120, a locking pin 128 is projected through the collar engagement recess 126 and then through the support arm recess 124 corresponding to the desired extension. Now referring to the clamping portion end of the support arm 40,94, it will become clear to one skilled in the art to which this invention pertains that any of the configurations of the first three embodiments previously described may be affixed thereto to provide an extensive degree of flexibility including the ability of the apparatus to accommodate poles 150 of extreme girth. In like manner, the support arm 40,94 may be extended to enable easy traversal about protruding limbs of excessive length or other oversized protrusions. According to FIG. 10 and for exemplary purposes only, the flanged end portion 50 of the third embodiment is shown affixed to the support arm 40,94 by locking pins 130. Other connecting devices such as bolts may be used. Quick release strap means 132 of the type previously described affix the climber 10 to the user's feet prior to ascending or descending the tree or pole in a stepwise manner. The strap means may also be configured with an ankle encasing arrangement 134 to provide additional stability to the user. As shown in this view, an array of pole-engaging protrusions 136 are integrally formed into the concave side of the clamping portion 48, as well as along each of the forward platform edges 138.
FIG. 11 is a top plan view of a right-foot climbing member 20 of the fourth embodiment of the invention shown in its mounted position about a pole 150. Protrusions 136 disposed on both platform and clamping portions 22,48 are shown engaging with an exemplary tree trunk 152 shown in this view. A side view of the embodiment of FIG. 11, partly in cross-section, is shown in FIG. 12, further illustrating the preferred mounting angle of the platform portion 22 relative to the support arm 40,94 and the tree trunk 152 on which the climber 10 is mounted. The angle between the plane of the platform portion 22 and the support arm 40,94 is about 30 degrees, and the platform portion 22 is about perpendicular to the longitudinal axis of the tree trunk 152.
Now referring to FIG. 13, a top plan view of a right-foot climbing member 20 of the first embodiment of the invention shows a pair of adjustable carrying straps 138 for transporting the climber 10 in a backpack-like manner. Each of straps 138 is affixed to the platform portion 22 with a pair of bolted or riveted connections 140, and is adjustable through a buckle means 142. When the climber 10 is not being transported, the straps 138 are folded and stored within recesses 144 formed into the seat cushion material layered on the top side of the platform portion 22. Padded sleeves 146 may be installed about the straps 138 to provide an additional degree of carrying comfort to the user during transport. FIG. 14 is a side view, partly in cross-section, of the embodiment of FIG. 13, further showing the carrying straps 138 affixed to the collapsed climber 10, the climber 10 shown in its fully transportable configuration.
Only one of the climbing devices 20 is provided with carrying straps 138 since the other climbing device may be compactly nested there with the Am-Lock strap device, previously mentioned, and can be used to maintain the two climbing devices in a compact nested condition during transportation or storage.
Although certain presently preferred embodiments of the invention have been described herein, it will be apparent to those skilled in the art to which the invention pertains that variations and modifications of the described embodiments may be made without departing from the spirit and scope of the invention. Accordingly, it is intended that the invention be limited only to the extent required by the appended claims and the applicable rules of law. | A tree climber comprising a pair of climbing members, adapted to be affixed to the user's feet by quick release straps. Each climbing member includes a support arm extending forward from a platform portion and terminating at one end of a moveable hook shaped clamping portion which engages the back side of the pole. Several embodiments show a clamping portion which is adjustably affixed to the terminus of the support arm with either a slidable collar and tube configuration or a clamped configuration. Another embodiment includes a slidable collar affixed to the platform portion, the support arm extending therethrough to a desired length corresponding to the diameter of the pole. The adjustable clamping portion of any of the embodiments may be used in combination with the extendable support arm to accommodate a wide range of tree trunk or pole diameters and to easily traverse protruding limbs which would otherwise arrest further vertical progress. A strapping assembly secures the tree climber to the tree at the desired elevation. In its collapsed configuration the climbing members are nested and easily transported or stored. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present patent application is related to U.S. patent application Ser. No. ______, entitled “Heated Chuck for Laser Thermal Processing,” filed on Dec. 1, 2004, the same day as the current application, and both are assigned to the present Assignee, Ultratech, Inc., of San Jose, Calif., which patent application is incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to apparatus and methods for thermally processing semiconductor substrates in semiconductor manufacturing, and in particular relates to support members (“chucks”) for supporting a substrate (semiconductor wafer) during laser thermal processing (LTP).
[0004] 2. Description of the Prior Art
[0005] The fabrication of integrated circuits (ICs) involves subjecting a semiconductor substrate to numerous processes, such as photoresist coating, photolithographic exposure, photoresist development, etching, polishing, and in some cases heating or “thermal processing”. Thermal processing is used, for example, to activate dopants in doped regions (e.g., source and drain regions) of the substrate for certain types of ICs. Thermal processing includes various heating (and cooling) techniques, such as rapid thermal annealing (RTA) and laser thermal processing (LTP).
[0006] Various techniques and systems for performing LTP of semiconductor substrates (“wafers”) are known and are used in semiconductor device manufacturing. Example LTP systems and methods are described in U.S. Pat. No. 6,747,245 entitled “Laser Scanning Apparatus and Methods for Thermal Processing” (the '245 patent), and in U.S. Pat. No. 6,366,308 B1, entitled “Laser Thermal Processing Apparatus and Method” (the '308 patent), which patents are incorporated by reference herein.
[0007] LTP involves rapidly bringing the temperature of the wafer up to the annealing temperature and then rapidly back down to the starting (e.g., ambient or background) temperature in a single cycle. Given of the relatively large sizes of the typical wafers used in semiconductor manufacturing (e.g., 300 mm in diameter), the heat is more efficiently applied to only a small region of the wafer at a given time.
[0008] Using the '245 patent and the '308 patent as examples, a laser beam is formed into a narrow high-intensity image (e.g., a line image) that is scanned over the wafer surface, e.g., in a raster pattern. This process can involve a heat flux in excess of 1000 W/mm 2 over the narrow image. The peak temperature TP reached by the wafer surface at the region being irradiated during LTP is relatively high (e.g., ˜1,300° C.).
[0009] The uniformity of the peak temperature TP determines the sheet resistance uniformity of activated doped regions formed therein, which in turn determines the performance of resulting semiconductor devices.
[0010] Attaining a uniform peak temperature TP over the wafer depends on the stability of the laser power and on the temperature uniformity of the wafer surface (referred to hereinbelow as the “background substrate temperature”). Maintaining a constant background temperature of the substrate, however, is problematic when the LTP process utilizes a spatially varying thermal load such as a scanned laser beam.
[0011] Accordingly, the art of LTP and related arts would benefit from apparatus and methods directed to maintaining the substrate being processed at a constant background temperature at the locations of the substrate not being directly subjected to the spatially varying thermal load.
SUMMARY OF THE INVENTION
[0012] One aspect of the invention is a chuck apparatus for laser thermal processing a substrate. The apparatus includes a housing having a planar upper surface, a lower surface, and an enclosed interior chamber. The chamber has a peripheral interior surface, which generally consists of the inner surfaces of the outer portions of the housing, such as the bottom surface of a top plate, the upper surface of a bottom plate, and the inner surface of a cylindrical sidewall capped by the top and bottom plates. The chamber is adapted to contain a metal in liquid and vapor form (referred to herein simply as a “metal liquid/vapor”). The chuck apparatus includes one or more heating elements arranged within the chamber interior. The one or more heating elements are adapted to heat the housing and the metal liquid/vapor to a background temperature. The apparatus also includes one or more wicks arranged adjacent the chamber peripheral interior surface. The one or more wicks are adapted to supply liquid metal to most, or all, of the chamber peripheral interior surface. Portions of the metal liquid/vapor are redistributed within the chamber by vaporizing the liquid metal at a hot spot within the chamber formed by heat transferred from the substrate to the chamber, and condensing the metal vapor away from the hot spot. This redistribution of the metal liquid/vapor serves to quickly uniformize the temperature of the housing, so that the temperature of the housing can be maintained at the background temperature.
[0013] Another aspect of the invention is a method of maintaining a substrate at a substantially constant background temperature while subjecting the substrate to a spatially varying thermal load, such as from a laser beam used to perform LTP of a semiconductor wafer as the substrate. The method includes transferring heat associated with the spatially varying thermal load from the substrate to a metal liquid/vapor held within a sealed chamber in thermal communication with the substrate. The transferred heat forms within the chamber a hot spot that is surrounded by cooler regions. The method also includes redistributing portions of the metal liquid/vapor by vaporizing the liquid metal at the hot spot, and condensing the metal vapor in the cooler regions to uniformize the temperature of the sealed chamber, and consequently, the substrate in good thermal communication therewith. The method may also include removing heat from the chamber using, for example, a heat sink in good thermal communication with the chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is an exploded side view of an example embodiment of the heater module of the present invention illustrating a short, hollow cylindrical center section capped by top and bottom plates that define the module chamber, and wherein a first cut-out (C 1 ) shows liquid and metal vapor within the chamber, a support brace along with openings in the braces that permit the circulation of metal throughout the chamber, and a second cut-out (C 2 ) shows a wick that lines most or all of the chamber interior surface, and liquid metal being conducted by the action of the wick to cover the chamber peripheral interior surface;
[0015] FIG. 2 is a top-down view of an example embodiment of the heater module of the present invention, shown with the top plate removed and a portion of the wick removed to reveal the internal components within the module chamber, and showing a portion of the wick (dotted line) adjacent the inner surface of the sidewall;
[0016] FIG. 3 is a cross-sectional view of a heated chuck for performing LTP of a substrate using an LTP laser beam, wherein the chuck includes the heater module of FIG. 1 , and illustrating the hot spot ( 812 ) and the cooler regions ( 814 ) of the chamber interior that occur during LTP irradiation; and
[0017] FIG. 4 is a close-up side view of the example embodiment of the top plate having a protective layer formed thereon that prevents contamination of the substrate.
[0018] The various elements depicted in the drawings are merely representational and are not drawn to scale. Certain proportions thereof may be exaggerated, while others may be minimized. The drawings are intended to illustrate various implementations of the invention, which can be understood and appropriately carried out by those of ordinary skill in the art.
DETAILED DESCRIPTION OF THE INVENTION
[0019] In the following detailed description of the embodiments of the invention, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are 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 changes may 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, and the scope of the present invention is defined only by the appended claims.
[0020] As mentioned above, achieving a uniform peak temperature over the substrate surface during LTP is critical in manufacturing semiconductor devices that require uniform sheet resistance of activated doped regions. Achieving peak temperature uniformity in LTP is facilitated by creating an environment wherein the substrate efficiently absorbs energy from the incident LTP laser beam. If the substrate is undoped or lightly doped, it is necessary to bring the substrate up to a constant background temperature TC prior to irradiating the substrate with the LTP laser beam in order to increase the absorption of the laser beam. Failure to do this can result in the beam passing through the substrate and to the chuck in some cases. Further, it involves maintaining the substrate at the constant background temperature TC even as the scanned LTP laser beam subjects the substrate to a spatially varying thermal load.
[0021] The chuck of the present invention is adapted to maintain a constant background substrate temperature TC significantly higher than room temperature even when the substrate is subject to the spatial varying thermal load from a scanned LTP laser beam. In an example embodiment, constant background temperature TC is in the range from about 350° C. to about 450° C. In one example embodiment, the constant background temperature TC is kept uniform across the substrate to +/−4° C., and in another example embodiment is kept uniform across the substrate to +/−6° C.
[0022] In the description below, the phrase “spatially varying thermal load” is used to describe the delivery of heat to different locations (positions) on the substrate at different times, e.g., by scanning an LTP laser over the substrate surface to be processed. As discussed below, the spatially varying thermal load on the substrate is communicated to corresponding locations within the heater module chamber.
[0023] Also, the phrase “constant background temperature” is understood to mean “constant or substantially constant,” wherein the variation in the background temperature is held to within a range that does not substantially affect the resultant LTP process. Likewise, the “constant background temperature” is assumed to be substantially uniform, i.e., is uniform over the substrate to the degree necessary to perform LTP of the substrate without substantial adverse results.
[0024] Also, in a preferred embodiment, the “constant background temperature” is elevated, i.e., is significantly higher than room temperature, e.g., 350° C. to 450° C. Also, the “constant background temperature” refers to the temperature of a portion of an object (e.g., the substrate) other than that portion immediately surrounding the spatially varying thermal load at any given time.
[0025] Further, the terms “gas” and “vapor” are used interchangeably herein. Also, as discussed below, the where term “metal” is intended to include both the liquid and vapor states, the phrase “metal liquid/vapor” is used for the sake of abbreviation and clarity.
[0000] Heater Module
[0026] FIG. 1 is an exploded side view of an example embodiment of a heater module 10 used in the chuck of the present invention. The chuck is described in detail below. Heater module 10 includes hollow cylindrical section (sidewall) 20 having respective upper and lower rims 22 and 24 and respective inner and outer surfaces 26 and 28 ( FIG. 2 ). Attached to upper rim 22 is a top plate 30 , and attached to lower rim 24 is a bottom plate 40 . Top plate 30 has an upper surface 32 and a lower surface 34 , and bottom plate 40 has an upper surface 42 and a lower surface 44 . Sidewall 20 , top plate 30 and bottom plate 40 constitute an enclosed, sealed housing having an enclosed interior chamber 50 . In an example embodiment, top plate 30 and bottom plate 40 are respectively sealed to upper and lower sidewall rims 22 and 24 , e.g., by welding.
[0027] Chamber 50 contains a metal 51 , which may be solid at room temperature, and both a liquid and a gas at the elevated operating or background temperature. Note that the portion of metal 51 in the vapor state is shown as small circles in FIG. 1 for the sake of illustration. In an example embodiment, metal 51 is or includes an alkali metal, such as one or more of potassium, cesium and sodium. In an example embodiment, metal 51 is introduced to interior chamber 50 during assembly and is permanently sealed therein during the operation of the heater module. In an example embodiment, the inner surface 26 of sidewall 20 , the bottom plate upper surface 42 and the top plate lower surface 34 define an example of a “chamber peripheral interior surface.”
[0028] In an example embodiment, sidewall 20 is formed from Monel-metal. Also in an example embodiment, top plate 30 and bottom plate 40 are formed from or otherwise include Monel-metal in order to safely contain metal liquid/vapor 51 , which in the case of an alkali metal such as potassium is very reactive.
[0029] FIG. 2 is a top-down view of heater module 10 of FIG. 1 , shown with top plate 30 removed to reveal the internal components of the module that reside within chamber 50 . In an example embodiment, heater module 10 includes one or more thin, rectangularly shaped braces 100 that span chamber 50 from one portion of sidewall inner surface 26 to another, and that extend upward from bottom plate upper surface 42 up to the plane defined by upper rim 22 . Braces 100 serve to define sub-chambers, such as sub-chambers 50 A, 50 B, 50 C and 50 D, within chamber 50 . Braces 100 preferably include openings 110 ( FIG. 1 ) sized to allow for metal liquid/vapor 51 to flow between the sub-chambers and throughout the entire chamber 50 , as described below. In an example embodiment, braces 100 are arranged at equal angles relative to one another and divide chamber 50 into equal-sized sub-chambers, such as the four sub-chambers 50 A- 50 D, as illustrated. In an example embodiment, heater module 10 also includes support members 55 , arranged in chamber 50 and mechanically coupled to top plate 30 and to bottom plate 40 to add stiffness to the heater module.
[0030] Heater module 10 further includes one or more heating elements 150 , such as heater cartridges, arranged to heat chamber 50 . Heating elements 150 serve to heat chamber 50 , and to convert some of the liquid metal to vapor. In an example embodiment, a number of heating elements (e.g., eight, as show in FIG. 2 ) are arranged adjacent inner surface 26 of sidewall 20 and extend inwardly toward the center of the chamber. In an example embodiment, a heating element 150 is arranged on either side of each brace 100 so that each sub-chamber 50 A- 50 D contains two heater elements.
[0031] Each heating element 150 is connected to a lead 190 (e.g., wires) that connects the heating element to a power supply 200 . Power supply 200 is adapted to provide select amounts of power to the heating elements, as described in greater detail below. Power supply 200 is operably connected to a heater module controller 220 that controls the operation of heater module 10 , as described in detail below. Each heating element 150 generates heat by dissipating electrical power provided to it by power supply 200 .
[0032] Heater module 10 also includes one or more temperature probes 300 at corresponding one or more positions within chamber 50 . Temperature probes 300 measure the temperature of chamber 50 at each of the one or more locations and generate corresponding temperature signals ST in response thereto. Temperature probes 300 are operably coupled to heater module controller 220 , which is adapted to receive and process the temperature signals.
[0033] With reference to FIGS. 1 and 2 , heater module 10 includes one or more wicking elements (“wicks”) 360 that cover most or all of chamber 50 peripheral interior surface. Wicks 360 serve to transport by capillary action liquid metal to most or all of the chamber peripheral interior surface. This process is illustrated in FIG. 1 in cut-out C 1 , which illustrates liquid metal 51 being conducted up wick 360 toward top plate lower surface 34 so that the chamber 50 peripheral interior surface is covered with a thin coating or film of liquid metal.
[0034] In an example embodiment, one or more wicks 360 are supported by or are fixed to bottom plate upper surface 42 and extend upward along inner wall surface 26 of sidewall 20 and extend across top plate lower surface 34 . In an example embodiment, one or more wicks 360 also cover heater elements 150 to facilitate the heating of liquid metal 51 .
[0035] In FIG. 1 , the wicks 360 , shown adjacent top and bottom plates 30 and 40 , have respective folded ends 361 that extend downward and upward along the inner surface 26 of sidewall 20 . This wick arrangement illustrates example embodiments wherein the folded ends either establish contact with an existing wick arranged along inner surface 26 , or meet up with one another to cover some or all of the sidewall inner surface.
[0036] In respective example embodiments, each wick 360 is in the form of a screen or fiber bundle made of metal, ceramic or glass compatible with the metal liquid/vapor. The material used in wicks 360 is preferably readily “wet” by the liquid metal. Wick 360 has interstices 362 sized to support capillary transfer of liquid metal 51 to those portions of the chamber peripheral interior surface not otherwise accessible by the liquid metal at rest within the chamber. The term “wet” as used herein refers to the requirement for a small contact angle between the liquid metal and the wick material. The wicking action of one or more wicks 360 serves to maintain a film of liquid metal on those portions of chamber peripheral interior surface that play a significant role in heat transport to and from the chamber, as described below. In an example embodiment, the entire chamber peripheral interior surface is covered with a film of liquid metal using one or more of wicks 360 .
[0000] Chuck With Heater Module
[0037] FIG. 3 is a side view of a heated chuck 500 for laser thermal processing according to the present invention, and that includes the heater module 10 discussed above. Chuck 500 includes a thermal insulator layer 520 having an upper surface 522 and a lower surface 524 . In an example embodiment, insulator layer 520 is arranged with its upper surface 522 immediately adjacent lower surface 44 of bottom plate 40 so that the insulator layer and the heater module are in good thermal communication. In an example embodiment, insulator layer 520 is in direct contact with bottom plate 40 , while in another example embodiment a thin layer of flexible graphite (not shown), such as GRAFOIL® (available from American Seal and Packing Co., Fountain Valley, Calif.), is arranged between the insulator layer and the bottom plate. In an example embodiment, insulator layer 520 is a plate of fused silica or quartz. In an example embodiment, insulator layer 520 includes LD-80, available from Pyromatics Corporation of Willoughby, Ohio.
[0038] Chuck 500 also includes a heat sink 600 arranged to be in good thermal communication with the insulator layer 520 through lower surface 524 . In an example embodiment, heat sink 600 is in the form of a cooled plate made from a material with a high thermal conductivity. In an example embodiment, the cooled plate of the heat sink is made of aluminum. In an example embodiment, heat sink 600 includes a cooling channel 602 (partially shown in FIG. 3 ) fluidly coupled to a cooling unit 540 adapted to flow a cooling fluid through the cooling channel to remove heat from the heat sink. In an example embodiment, cooling channel 602 is formed in the cooled plate.
[0039] Insulator layer 520 is arranged between heater module 10 and heat sink 600 and is adapted to maintain a substantially constant thermal gradient between the two. In an example embodiment, heater module 10 is at a temperature of about 400° C., while heat sink 600 is at a temperature of about 20° C.
[0040] Upper surface 32 of top plate 30 is adapted to support a substrate (semiconductor wafer) 700 having an upper surface 702 , a lower surface 704 and an outer edge 706 . With reference to FIG. 4 , in an example embodiment, top plate 30 includes, atop upper surface 32 , a layer 710 of material (e.g., a coating or a plate) having an upper surface 712 upon which substrate 700 is supported. The material making up layer 710 is one that does not contaminate substrate 700 . Example materials for layer 710 include silicon, silicon oxide or silicon nitride, or any combination thereof.
[0041] With reference again to FIG. 3 , chuck 500 also includes a chuck controller 720 operably coupled to heater module controller 220 . Chuck controller 720 controls the operation of the chuck, including the heater module, as described below. Chuck controller 720 is also operably coupled to cooling unit 540 to control the flow of a cooling fluid (e.g., water) through cooling channel 602 of heat sink 600 .
[0000] Method of Operation
[0042] With continuing reference to FIG. 3 , there is also shown a LTP laser beam 880 incident upon substrate upper surface 702 . LTP laser beam 880 is moved (“scanned”) over substrate surface 702 as part of performing LTP of substrate 700 , e.g., to activate dopants in the substrate at or near the substrate upper surface.
[0043] LTP laser beam 880 presents a spatially varying thermal load to the substrate that will ultimately end up increasing the substrate's background temperature if the heat it creates in the substrate is not properly dissipated. Any change in the substrate background temperature creates undesirable variations in the LTP process, and in particular affects the activation of dopants in the substrate during LTP.
[0044] Accordingly, prior to irradiating substrate 700 with LTP laser beam 880 , chuck controller 720 instructs heater module controller 220 via a signal S 1 to activate power supply 200 via signal S 2 . In response thereto, power supply 200 provides electrical power (shown schematically as arrow 810 ) to heating units 150 via a power signal SP, which heats up heater module 10 by introducing heat into chamber 50 . In an example embodiment, the power input from power supply 200 is about 3.5 kW steady state to maintain heater module 10 at about 400° C.
[0045] The liquid metal 51 contained in chamber 50 is heated by heating units 150 . This heat quickly and uniformly spreads over the entire inner surface of chamber 50 of heater module 10 via the wicking action of wicks 360 and the evaporation and condensation of the metal liquid/vapor within the chamber. Heat transport is highest at the chamber peripheral interior surface, which is mostly, or entirely, covered by wicks 360 . With substrate 700 in good thermal contact with heater module 10 , the substrate takes on the constant background temperature TC of the heater module.
[0046] Heater module controller 220 also receives temperature signals ST from temperature probes 300 and uses these signals to regulate the temperature of heater module 10 by providing the temperature information to the heater module controller 220 . In response, heater module controller 220 regulates the amount of power 810 (via power signal SP) supplied by power supply 200 to heating units 150 . In this manner, the temperature of the heater module, as measured by temperature probes 300 , can be precisely controlled, e.g., to within 1° C.
[0047] With continuing reference to FIG. 3 , when substrate 700 is brought up to a desired constant background temperature TC, then LTP laser beam 880 is scanned over substrate upper surface 702 . This introduces a spatially varying thermal load on the substrate, which translates to a spatially varying temperature on the substrate. This, in turn, creates a corresponding spatially varying temperature within chamber 50 of heater module 10 . Chamber 50 has a “hot spot” 812 corresponding to the position of the LTP laser beam at substrate surface 702 , and “cooler regions” 814 surrounding the hot spot. Hot spot 812 moves around chamber 50 as LTP laser beam 880 scans over substrate surface 702 .
[0048] The temperature variation in chamber 50 caused by the spatially varying thermal load is quickly ironed out by the evaporation and condensation of metal liquid/vapor 51 within the chamber, by the movement of the metal vapor throughout the chamber volume, and by the movement of the liquid metal via capillary action through the one or more wicks 360 covering the chamber peripheral interior surfaces. The transfer of heat and metal vapor from hot spot 812 out to cooler regions 814 is illustrated in FIG. 3 by arrows 816 .
[0049] Metal 51 in liquid form is capable of absorbing copious amounts of heat by evaporation because of its large latent heat of vaporization. The metal liquid turns to vapor in the “hot spots” 812 in the cavity corresponding to the location of the scanned LTP laser beam 880 at substrate 700 . The vaporized metal is then replaced by liquid metal via capillary action of one or more wicks 360 . The metal vapor then condenses to a liquid state in the cooler regions 814 of the chamber as the spatially varying thermal load moves to a different region of the chamber. The heat taken in by heater module 10 is transferred to heat sink 600 through insulator layer 520 , and is dissipated, as illustrated by power-out arrow 820 .
[0050] Insulator layer 520 is adapted to maintain a substantially constant thermal gradient between the heater module and the heat sink, and therefore transfers heat from one to the other at a substantially constant rate. This rate is chosen so that the heater module can be electrically controlled at the constant background temperature, even when the laser is operated at maximum power.
[0051] In an example embodiment, the amount of heat removed from chamber 50 is greater than that provided by the spatially varying thermal load associated with LTP laser beam 880 , less an amount of heat lost by radiation and convection from substrate 700 and the heater chamber. This ensures that the heating system (i.e., heating elements 150 , power supply 200 , heater module controller 220 and temperature probes 300 ) is required to provide some heat to maintain the heater module, and thus the substrate, at the substantially constant background temperature TC.
[0052] The very high thermal conductivity effectively provided by heater module 10 ensures a high degree of temperature uniformity (e.g., to within +/−4° C.) except, of course, at or in close proximity to the position on the substrate being subject to the thermal load, e.g., LTP laser beam 880 . This in turn allows the substrate to have a uniform constant background temperature TC at those locations not being irradiated by LTP laser beam 880 . The maximum temperatures reached during the LTP process depend primarily on the substrate temperature at the beginning of the annealing cycle and the power stability in the laser beam. Keeping the substrate temperature uniform therefore assists in keeping the LTP annealing process uniform. This translates into consistent and reliable device performance.
[0053] The many features and advantages of the present invention are apparent from the detailed specification, and, thus, it is intended by the appended claims to cover all such features and advantages of the described apparatus that follow the true spirit and scope of the invention. Furthermore, since numerous modifications and changes will readily occur to those of skill in the art, it is not desired to limit the invention to the exact construction and operation described herein. Accordingly, other embodiments are within the scope of the appended claims. | Chuck methods and apparatus for supporting a semiconductor substrate and maintaining it at a substantially constant background temperature even when subject to a spatially and temporally varying thermal load. Chuck includes a thermal compensating heater module having a sealed chamber containing heater elements, a wick, and an alkali metal liquid/vapor. The chamber employs heat pipe principles to equalize temperature differences in the module. The spatially varying thermal load is quickly made uniform by thermal conductivity of the heater module. Heatsinking a constant amount of heat from the bottom of the heater module accommodates large temporal variations in the thermal heat load. Constant heat loss is preferably made to be at least as large as the maximum variation in the input heat load, less heat lost through radiation and convection, thus requiring a heat input through electrical heating elements. This allows for temperature control of the chuck, and hence the substrate. | 1 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to an interrogator that exchanges information with transponders by using an RF signal of the macro-wave band, specifically to an interrogator provided with antennas suitable for exchanging RF signals with multiple transponders.
[0002] Movable body identification equipment (identification system by radio waves) is composed of an interrogator and plural transponders responding to the interrogator. The interrogator radiates an RF signal of the microwave band (including the quasi-microwave band) from an antenna to the transponders not having the cells, and exchanges information with the transponders. The transponders receive the RF signal from the interrogator with small antennas, and rectify the RF signal to attain the DC power supply, clocks and data, and in response to the data, answer the information of the memory to the interrogator from the small antennas.
[0003] The exchange of information includes, for example, discrimination of identification numbers different in each of the transponders. In this case, applying the transponders on articles such as packages will achieve a system that discriminates the packages being carried on a belt conveyer, without using human hands (for example, refer to International Publication No. WO98/21691).
[0004] The distance of communication within which the information exchange is possible between the interrogator and the transponders is determined depending on the antenna and the power of an RF transmitting signal that the interrogator generates, in case of the capability and the shape and size of the transponders being constant. If the antenna is a phased array antenna that is synthesized with multiple antenna elements, the distance of communication will be prolonged. If the antenna is an antenna with single element, the communication area will be limited within an area near the antenna; thus, the antenna structure of the interrogator limits the range of the distance of communication. A traveling wave antenna is used, for example, in equipment having the transponders applied to the examination of tickets, which discriminates the transponders one by one (refer to Japanese Utility Model Laid-open (Kokai) No. Hei 2-32174).
SUMMARY OF THE INVENTION
[0005] In a case where a single interrogator is desired to secure communications with as many transponders as possible, an antenna configuration for the interrogator that allows an array of multiple transponders within a communication area becomes essential.
[0006] However, in a quasi-microwave band, for example, a phase synthesis of an electromagnetic wave radiated from the interrogator and electromagnetic waves radiated from the transponders in the space is apt to create fluctuations of the electromagnetic waves; and it is difficult to realize a uniform electromagnetic field over a wide range. Further, if plural transponders are arrayed close to each other, the mutual coupling between the antennas will disturb the radiation characteristic to thereby deteriorate the antenna characteristic, which makes it difficult to attain the power that the transponders need.
[0007] The present invention has been made in view of the foregoing circumstances, and it provides an interrogator having an antenna that secures an intensified and uniform electromagnetic energy concentrated on areas near antenna elements and thereby achieves an array of multiple transponders in a shorter distance of communication, and a goods management system applying the same.
[0008] In order to solve the problem of the invention, the interrogator is furnished with a sleeve antenna that includes a monopole conductor of {fraction ( 1 / 4 )} wavelength (free space wavelength) continuously connected to a core wire of a coaxial cable on one end thereof, and a feed point on the other end, in which the sleeve antenna is grounded at the feed point. An antenna having such a physical makeup generates an electromagnetic field on an outer conductor of the coaxial cable, and by setting the part of the coaxial cable to a length of some wavelengths, the part functions as an antenna. Accordingly, it becomes possible to array plural transponders in an area covering a length of some wavelengths from the open end of the sleeve antenna.
[0009] First, the general characteristic of a sleeve antenna will be discussed. FIG. 1 illustrates a basic configuration of the monopole antenna. The antenna includes a monopole in which the coaxial cable having a core wire 1 and a dielectric substance 3 and an outer conductor 2 extends the core wire 1 from the open end by a length of about ¼ wavelength of the free space wavelength, which is excited by a signal source 5 . And, it is idealistic that an infinite ground plane 4 is formed vertically to the monopole antenna including the open end.
[0010] The radio wave radiated from a monopole antenna having this sort of configuration has a voltage distribution V, a current distribution Cl, and a radiation pattern P between the core wire 1 (monopole antenna) and the ground plane 4 , as shown in FIG. 2. The radiation pattern P is formed at the symmetric position to the monopole antenna 1 .
[0011] Here, as shown in FIG. 3, if the grounding is made at a feed point 14 , the ground plane will move to the feed point 14 , and varies the voltage and current distributions on the antenna. The signal from the signal source 5 is transmitted through the coaxial cable, and resonates at the signal source frequency on the monopole portion 1 to radiate an electromagnetic wave. At that moment, the outer conductor 2 of the coaxial cable has a voltage or current excited, which forms a current distribution C 2 shown in FIG. 4. FIG. 4 illustrates an equivalent characteristic of the antenna shown in FIG. 3. In the monopole antenna shown in FIG. 1, only the equivalent portion to the ¼ wavelength functions as an antenna; however, in the sleeve antenna shown in FIG. 3, on the portion of the outer conductor 2 of the coaxial cable is created a voltage or current distribution, whereby the electromagnetic wave is radiated from the outer conductor 2 as well. That is, the whole structure including the monopole antenna and the coaxial cable portion functions as an antenna. The invention adopts the sleeve antenna shown in FIG. 3.
[0012] Thus, in the sleeve antenna shown in FIG. 3, an intensified and uniform electromagnetic energy is securely attained to be concentrated on areas near the monopole antenna and the coaxial cable portion. Accordingly, multiple transponders can be arrayed in that area. In other words, even if the antenna characteristics of the transponders are deteriorated, or even if the electromagnetic distributions are different in the fluctuations, the areas adjacent to the antenna elements attain an intensified electromagnetic field, which makes it possible to secure the electromagnetic energy over a wide area that the individual transponders need.
[0013] Here, the electromagnetic wave radiated by the antenna shown in FIG. 3 is spread all around the circumference of the coaxial cable. Therefore, in case of using the microwave band, it is effective to form a physical makeup such that the antenna is disposed close to a ground plane though a thin dielectric layer (or film) less than few millimeters, and the electromagnetic wave radiated toward the ground plane is reflected by the ground plane to radiate on the other side of the ground plane. In consequence, the electromagnetic energy supplied to the transponders can be increased.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Preferred embodiments of the present invention will be described in detail based on the followings, wherein:
[0015] [0015]FIG. 1 is a chart explaining a configuration of a monopole antenna;
[0016] [0016]FIG. 2 is a chart explaining a current/voltage distribution of the monopole antenna and a radiation pattern of an electromagnetic wave;
[0017] [0017]FIG. 3 is a chart explaining a configuration of a sleeve antenna;
[0018] [0018]FIG. 4 is a chart explaining a current distribution of the sleeve antenna;
[0019] [0019]FIG. 5( a ) illustrates a plan view that explains an interrogator as the first embodiment relating to the invention;
[0020] [0020]FIG. 5( b ) illustrates a side view that explains an interrogator as the first embodiment relating to the invention;
[0021] [0021]FIG. 6( a ) illustrates a plan view that explains an interrogator as the second embodiment relating to the invention;
[0022] [0022]FIG. 6( b ) illustrates a side view that explains an interrogator as the second embodiment relating to the invention;
[0023] [0023]FIG. 7( a ) illustrates a plan view that explains an interrogator as the third embodiment relating to the invention;
[0024] [0024]FIG. 7( b ) illustrates a side view that explains an interrogator as the third embodiment relating to the invention;
[0025] [0025]FIG. 8 is a side view that explains an interrogator as the forth embodiment relating to the invention;
[0026] [0026]FIG. 9 is a chart explaining a configuration of an interrogator as the fifth embodiment of the invention;
[0027] [0027]FIG. 10 is a block diagram explaining an example of an RF signal line controller used in the interrogator in FIG. 9;
[0028] [0028]FIG. 11 is a block diagram explaining an example of a switching signal generation circuit used in the RF signal line controller in FIG. 10;
[0029] [0029]FIG. 12 is a block diagram explaining another example of the RF signal line controller used in the interrogator in FIG. 9;
[0030] [0030]FIG. 13 is a perspective view explaining a stock control system applying the interrogator antennas as the sixth embodiment of the invention;
[0031] [0031]FIG. 14 is a perspective view explaining managed goods in the sixth embodiment in FIG. 13;
[0032] [0032]FIG. 15( a ) illustrates a plan view that explains an interrogator as the seventh embodiment relating to the invention;
[0033] [0033]FIG. 15( b ) illustrates a side view that explains an interrogator as the seventh embodiment relating to the invention;
[0034] [0034]FIG. 16( a ) illustrates a plan view that explains an interrogator as the eighth embodiment relating to the invention; and
[0035] [0035]FIG. 16( b ) illustrates a side view that explains an interrogator as the eighth embodiment relating to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0036] An interrogator relating to the invention and a goods management system applying the same will be discussed further in detail with reference to some embodiments shown in the accompanying drawings.
[0037] FIGS. 5 ( a ) and 5 ( b ) illustrate an interrogator as the first embodiment of the invention, which includes plural sleeve antennas switched by selectors and plural transponders arrayed near each of the sleeve antennas, and manages multiple transponders as a whole. FIG. 5( a ) is the plan view and FIG. 5( b ) is the side view. In FIGS. 5 ( a ) and 5 ( b ), 16 a - 16 e denote the sleeve antennas as shown in FIG. 3, 113 denotes an interrogator body, 111 an RF signal line that supplies the sleeve antennas 16 a - 16 e with an RF signal from the interrogator body 113 through an input/output terminal 112 , and 17 a - 17 e denote RF signal selectors that switch the connections between each of the sleeve antennas and the RF signal line 111 . Each of the sleeve antennas has the outer conductor grounded at the feed point. Further, 19 denotes a dielectric plate, and 18 a conductive plate (ground plane) stuck on the rear side of the dielectric plate 19 . The above construction forms an interrogator antenna incorporated with the interrogator body 113 .
[0038] Further, in FIGS. 5 ( a ) and 5 ( b ), 110 denotes a transponder group disposed on the front side of the dielectric plate 19 , very close to the sleeve antennas 16 a - 16 e . Each of the transponders forms a long and narrow plane rectangle, and in a practical use, it is stuck on the side face of an article in stock control, for example. FIGS. 5 ( a ) and 5 ( b ) omit to illustrate the articles, and shows the state that the rectangular transponders put on all the articles in stock control are arranged.
[0039] Each of the rectangular transponders incorporates a rectangular-shaped antenna and an IC chip. The IC chip includes a rectifier that rectifies an RF signal from the antenna to generate a DC voltage, a receiving circuit that extracts clocks and data, etc., from the RF signal, a memory that stores information such as the identification number of its own, and a transmitting circuit that transmits the information of the memory in accordance with the received data, using the received RF signal.
[0040] Further, the interrogator body 113 includes a transmitting circuit that modulates data for interrogation into an RF signal, and a receiving circuit that receives a signal transmitted from a transponder and extracts information.
[0041] The sleeve antennas 16 a - 16 e are disposed inside the dielectric plate 19 , with such a degree of spacing that the antennas do not come in direct contact with the transponder group 110 electrically mechanically.
[0042] The ground plane 18 is placed close to the sleeve antennas 16 a - 16 e , on the side opposite to the transponder group 110 ; and, it reflects the radio waves that the sleeve antennas radiate to the transponder group 110 so as to increase the power supplied thereto.
[0043] As shown in FIGS. 5 ( a ) and 5 ( b ), the sleeve antennas 16 a - 16 e are disposed slant to the dielectric plate 19 . When the sleeve antennas 16 a - 16 e have such an angle in the layout, and each of the transponder antennas has the linearly polarized wave, the plane of vibration of the linearly polarized wave of the transponder antennas moves in close to the plane of vibration of the linearly polarized wave of the sleeve antennas 16 a - 16 e (to the longitudinal direction of the antennas), which raises the power for exchanging the RF signals.
[0044] When each of the transponder antennas has the plane of vibration of the linearly polarized wave in the longitudinal direction along the rectangular shape of the transponder, the RF signal can be exchanged at the maximum efficiency by bringing the plane of vibration into coincidence with the longitudinally directional plane of vibration of the sleeve antennas. However, since the number of the transponders that one sleeve antenna can communicate with decreases in that case, it is effective to lay out the sleeve antennas with an angle as shown in FIGS. 5 ( a ) and 5 ( b ), thereby increase the number of the transponders, even with a slight decrease of the efficiency.
[0045] This embodiment achieves an interrogator with antennas that enables multiple arrangements of the transponders.
[0046] FIGS. 6 ( a ) and 6 ( b ) illustrate an interrogator as the second embodiment of the invention, in which the sleeve antennas are arranged in the longitudinal direction of the dielectric plate. FIG. 6( a ) and FIG. 6( b ) are the plan view and the side view, respectively. In FIGS. 6 ( a ) and 6 ( b ), 26 a - 26 e denote the sleeve antennas disposed in parallel to the longitudinal direction of a dielectric plate 29 . The other configuration is the same as in the first embodiment. That is, the sleeve antennas 26 a - 26 e , RF signal selectors 27 a - 27 e , RF signal line 211 , RF signal input/output terminal 212 , and ground plane 28 configure an interrogator antenna, and a transponder group 210 is disposed very close to the sleeve antennas 26 a 26 e . Here, the interrogator body is omitted in the drawing.
[0047] The sleeve antennas 26 a - 26 e in the second embodiment have the plane of vibration perpendicular to the plane of vibration of the rectangular transponder antennas. This configuration of the plane of vibration of the transponders being perpendicular to that of the sleeve antennas weakens the impedance coupling between the sleeve antennas and the transponder antennas, and decreases the power to be supplied. However, in reverse, the load is apt to be lessened each other, and thereby the optimization of the distance between them will realize an interrogator with the sleeve antennas capable of communicating multiple transponders.
[0048] FIGS. 7 ( a ) and 7 ( b ) illustrate an interrogator as the third embodiment of the invention, in which the sleeve antennas are disposed to shorten the RF signal line for the power distribution. FIG. 7( a ) and FIG. 7( b ) are the plan view and the side view, respectively. To shorten the RF signal line is to decrease the loss of the RF signal generated.
[0049] In FIGS. 7 ( a ) and 7 ( b ), 36 a - 36 e denote the sleeve antennas disposed with the orientations reversed each other, in parallel to the longitudinal direction of a dielectric plate 39 . 311 denotes an RF signal line that feeds the RF signal to the antennas arranged in that manner, 312 an RF signal input/output terminal arranged virtually on the center of the RF signal line 311 . The other configuration is the same as in the second embodiment. That is, the sleeve antennas 36 a - 36 e , RF signal selectors 37 a - 37 e , RF signal line 311 , RF signal input/output terminal 312 , and ground plane 38 configure an interrogator antenna, and a transponder group 310 is disposed very close to the sleeve antennas 36 a - 36 e . Here, the interrogator body is omitted in the drawing.
[0050] The third embodiment has the advantage of reducing the RF signal loss generated in the RF signal line 311 , by arranging the sleeve antennas 36 a - 36 e with the orientations changed so as to shorten the length of the RF signal line 311 , and integrating the RF signal selectors 37 a and 37 b , and 37 c and 37 d each into one IC package.
[0051] [0051]FIG. 8 illustrates an interrogator as the fourth embodiment of the invention, in which the interrogator antennas of the first, the second, or the third embodiment are connected in parallel. In FIG. 8, 65, 66 , 67 each denote the interrogator antenna as shown in either of FIGS. 5 ( a ) and 5 ( b ) -FIGS. 7 ( a ) and 7 ( b ) (hereafter, this will be mentioned as antenna group). 68 denotes an RF signal line 311 , 69 an RF signal input/output terminal of the interrogator antenna in this embodiment. The interrogator antenna in this embodiment uses a plurality of the antenna groups shown in either of FIGS. 5 ( a ) and 5 ( b )—FIGS. 7 ( a ) and 7 ( b ), so that the processable number of the transponders can further be increased.
[0052] Here, to increase of the number of the parallel connections elongates the RF signal line 68 , and increases the RF signal loss; however, if the output power of the RF signal of the interrogator body is high, or if the receiving sensitivity of each transponder is high, the permissible RF signal loss will be high, and the number of the parallel connections will become possible to increase, without being limited to three in FIG. 8.
[0053] [0053]FIG. 9 illustrates an interrogator as the fifth embodiment of the invention, which is provided with the RF signal selectors for each of the antenna groups. In FIG. 9, 70 - 77 signify antenna groups shown in either of FIGS. 5 ( a ) and 5 ( b )—FIGS. 7 ( a ) and 7 ( b ), ANTk 0 -ANTk 07 (k=0-7) sleeve antennas that the antenna group 7 k includes, a 0 -a 7 RF signal selectors furnished with each of the sleeve antennas, b 0 -b 7 RF signal selectors furnished with each of the antenna groups 70 - 77 , 78 an RF signal line that supplies the RF signal to the RF signal selectors b 0 -b 7 , 79 an RF signal line controller that controls the connection/disconnection of the RF signal selectors a 0 -a 7 and the RF signal selectors b 0 -b 7 , and 80 an RF signal input/output terminal of the interrogator antenna of this embodiment.
[0054] The interrogator antenna of this embodiment uses 64 sleeve antennas in total, one of which is selected in accordance with the operation of the RF signal selectors a 0 -a 7 and the RF signal selectors b 0 -b 7 and is connected to the RF signal line 78 , which is controlled by the RF signal line controller 79 .
[0055] In this embodiment, since each antenna group has the RF signal selector, the load of the interrogator body is reduced in comparison to the forth embodiment, and more antenna groups can be installed. Accordingly, the processable number of the transponders can be increased to a great extent.
[0056] [0056]FIG. 10 illustrates an example of the RF signal line controller 79 . Since the antenna switching circuits and the peripheral circuits thereof, which constitute each RF signal selector, are disposed close to each of the antennas, the supply voltage that drives a switching control signal and each circuit is preferably supplied through one RF signal line together with the RF signal. The line controller 79 in FIG. 10 is configured in view of the above.
[0057] In FIG. 10, 89 signifies a switching signal superposing circuit tat superposes a dc voltage from a power supply terminal 90 and a control signal from a control terminal 91 on an RF signal from an RF signal input/output terminal 98 , and 92 signifies a transmission line. Further, 93 signifies a switching signal separation circuit that separates the RF signal, control signal, and supply voltage from the signal sent by the transmission line 92 , 94 a low pass filter that omits undesired RF components from the supply voltage that the switching signal separation circuit 93 has separated, 95 a switching signal generation circuit that generates switching signals to the RF signal selectors a 0 -a 7 and the RF signal selectors b 0 -b 7 , on the basis of the control signal that the switching signal separation circuit 93 has separated, and 96 an antenna switching circuit, which is composed of the selectors a 0 -a 7 and the selectors b 0 -b 7 .
[0058] The low pass filter 94 supplies the supply voltage to the switching signal generation circuit 95 and the antenna switching circuit 96 . The RF signal to the antenna to be switched is inputted/outputted through the RF signal input/output terminal 97 . Only one of the sleeve antennas of the interrogator antenna is selectively connected to the RF signal line 78 (transmission line 92 ), by the switching, whereby communications between plural transponders become possible.
[0059] [0059]FIG. 11 illustrates an example of the switching signal generation circuit 95 . In FIG. 11, 107 signifies a switching signal input terminal, 108 , 109 signify a 4-bit binary counter, 110 , 111 a 3-to-8 line decoder, and 112 , 113 an octal D-type latch.
[0060] As an arbitrary number of pulses are inputted as the control signal from the switching signal input terminal 107 , the switching signal input terminal 108 counts the number of the pulses, and the output signal at the third bit is inputted to the clock input CLK of the 4 bit binary counter 109 . The 3-bit outputs QA, QB, QC of the 4-bit binary counter 108 pass through the 3-to-8 line decoder 110 and the octal D-type latch 112 to be converted into the switching signals that drive the selectors a 0 -a 7 provided to the sleeve antennas. The switching signals are capable of switching plural (8, at the maximum) sleeve antennas.
[0061] The 4-bit binary counter 109 increments one count every 8 counts of the 4-bit binary counter 108 . The 3-bit outputs QA, QB, QC of the 4-bit binary counter 109 pass through the 3-to-8 line decoder 111 and the octal D-type latch 113 to be converted into the switching signals that drive the selectors b 0 -b 7 provided to the antenna groups. The switching signals are capable of switching plural ( 8 , at the maximum) antenna groups.
[0062] Next, FIG. 12 illustrates another example of the RF signal line controller 79 . In this example, rectifying a part of the RF signal generates the power supply voltage. In FIG. 12, 100 signifies a switching signal superposing circuit tat superposes a control signal from the control terminal 91 on the RF signal from the RF signal input/output terminal 98 . 103 signifies a switching signal separation circuit that supplies an RF signal to the antenna switching circuit 96 and a rectifying circuit 104 by an internal coupling circuit thereof, and separates the control signal superposed on the RF signal. The rectifying circuit 104 rectifies an inputted RF signal to generate a dc supply voltage to be supplied to the switching signal generation circuit 95 and the antenna switching circuit 96 . The other circuits are the same as those shown in FIG. 10, and the explanation will be omitted. Also in this example, only one of the sleeve antennas of the interrogator antenna is selectively connected to the RF signal line 78 , by the switching, whereby communications between plural transponders become possible.
[0063] [0063]FIG. 13 illustrates a stock control system as the sixth embodiment of the invention, in which the interrogator antennas shown in FIG. 9 are applied to a rack of plural shelves that controls the reception and stock of managed goods. The managed goods includes a file and document, CD (Compact Disk), DVD (Digital Versatile Disk), etc., and a control terminal controls the goods using an identified result by the interrogator.
[0064] [0064]FIG. 13 illustrates the shelves up to two. In FIG. 13, 121, 128 each denote a shelf board on the lower shelf, and a shelf board on the upper shelf; the antenna group is installed on each shelf board, and an interrogator 115 is installed on the right near side of the lower shelf board 121 . The interrogator 115 has a control terminal 132 connected thereto, through a control line 114 .
[0065] The antenna group installed on the shelf board 121 possesses a board 120 , four sleeve antennas 119 embedded in the board 120 , an RF signal selector 118 for the sleeve antennas 119 , and an RF signal selector 117 for the antenna group. The managed goods are placed on the antenna group, which are illustrated with the symbol 123 in FIG. 13, and as described later, rectangular transponders 122 are applied on the managed goods 123 . And, the RF signal line and the ground plane are formed on the board 120 , which are not illustrated in the drawing.
[0066] Similarly, the antenna group installed on the shelf board 128 possesses a board 127 , four sleeve antennas 125 embedded in the board 127 , an RF signal selector 134 for the sleeve antennas 125 , and an RF signal selector 126 for the antenna group. The managed goods are placed on the antenna group, which are illustrated with the symbol 124 in FIG. 13, and rectangular transponders 133 are applied on the managed goods 124 . And, the RF signal line and the ground plane are formed on the board 127 , which are not illustrated in the drawing. The board 127 and the RF signal line thereon are connected to the interrogator 115 through RF coaxial cables 129 , 131 connected to RF coaxial connectors 116 , 130 . In this embodiment, the interrogator 115 includes the function of the switching signal superposing circuit of the RF signal line controller.
[0067] [0067]FIG. 14 illustrates a form of the managed goods 123 , 124 . The managed goods 123 ( 124 ) has the form, such as a file, document, CD, DVD, and the like. The rectangular transponders 122 ( 133 ) are applied on the underside of the managed goods 123 ( 124 ) so as to face to the sleeve antennas 119 , 125 .
[0068] In this embodiment, the RF signal selectors 117 , 126 select either of the antenna groups installed on the shelf boards 121 , 128 ; further, the RF signal selectors 118 , 134 select either one of the sleeve antennas 119 , 125 . And, the number of the antennas 119 , 125 installed and the location thereof recognizes that a managed goods of which identification number stays at which location of which shelf board. Thus, a further subdivided location becomes possible, and a fine stock control becomes possible accordingly.
[0069] And, in view of the distinctive features of the invention, it is widely applicable to the control of goods, such as a goods control in a shop, a files and books control in an office, etc., in addition to the above stock control.
[0070] Now, if an optical indicator such as an LED is used which lights or flickers by the switching signal in combination with the RF signal selectors 117 , 126 , and the RF signal selectors 118 , 134 , it will be possible to confirm by visual observation the location of a managed goods on which a rectangular transponder for exchanging data is attached.
[0071] FIGS. 15 ( a ) and 15 ( b ) illustrate an interrogator using such an optical indicator, as the seventh embodiment of the invention. FIG. 15( a ) and FIG. 15( b ) are the plan view and the side view, respectively. The basic structure of the interrogator antenna is the one from the second embodiment shown in FIGS. 6 ( a ) and 6 ( b ); and indicators 145 - 149 are each connected to the sleeve antenna sides of the RF signal selectors 27 a - 27 e . Naturally, any of the interrogator antennas in the first through third embodiments and the antenna groups in the fourth through sixth embodiments can be the basic structure of the interrogator antenna to which the indicators 145 - 149 are connected.
[0072] One of the indicators 145 - 149 lights or flickers, when one of the RF signal selectors 27 a - 27 e corresponding to the indicator is selected, whereby the selected sleeve antenna can be confirmed by visual observation.
[0073] Further, the indicators can be attached to the RF signal selectors b 0 -b 7 in FIG. 9, as well as to the RF signal selectors 117 , 126 in FIG. 13, in addition to the RF signal selectors 27 a - 27 e . When one of the selectors is selected, the corresponding indicator lights or flickers, which enables the confirmation of a selected antenna group by visual observation.
[0074] Next, FIGS. 16 ( a ) and 6 ( b ) illustrate an interrogator using a sound source instead of an optical indicator, as the eighth embodiment of the invention. FIG. 16( a ) and FIG. 16( b ) are the plan view and the side view, respectively. Sound sources 165 - 169 are each connected to the sleeve antenna sides of the RF signal selectors 27 a - 27 e.
[0075] The sound sources 165 - 169 are made up with piezoelectric buzzers that emit audible sounds, and so forth. When any one of the RF signal selectors 27 a - 27 e is selected, the sound source corresponding to the selected one of the selectors emits an audible sound; accordingly, it becomes possible to confirm the selected sleeve antenna by hearing the sound. Naturally, any of the interrogator antennas in the first through third embodiments and the antenna groups in the fourth through sixth embodiments can be the basic structure of the interrogator antenna to which the sound sources 165 - 169 are connected.
[0076] Further, the sound sources can be attached to the RF signal selectors b 0 -b 7 in FIG. 9, as well as to the RF signal selectors 117 , 126 in FIG. 13, in addition to the RF signal selectors 27 a - 27 e . When one of the selectors is selected, confirming the sound of the sound source connected to the selected selector permits the confirmation of a selected antenna group.
[0077] Further, it is also possible to combine the indicators and the sounds source. It is possible to properly use the indicators and the sound sources, in a case suitable for making sounds and a case suitable for emitting lights, and also possible to use both at the same time.
[0078] According to the invention, the antenna group is able to secure an intensified and uniform electromagnetic energy concentrated on the areas near the antenna elements, which accomplishes an interrogator that enables information exchange with multiple transponders in a shorter distance of communication. Using the interrogator of the invention will achieve movable body identification equipment such as a goods management system that identifies multiply arrayed goods, and so forth.
[0079] It should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalence of the appended claims. | The invention provides an interrogator with an antenna that allows information exchanges with multiple transponders in a shorter distance of communication, by securing an intensified and uniform electromagnetic energy concentrated on areas near antenna elements. The interrogator is furnished with a sleeve antenna that includes a monopole conductor of ¼ wavelength (free space wavelength) continuously connected to a core wire of a coaxial cable on one end thereof, and a feed point on the other end, in which the sleeve antenna is grounded at the feed point. The interrogator has a plurality of the transponders arrayed near the antenna, and a plurality of the antennas selected by RF signal selectors. The interrogator antenna of the invention will achieve movable body identification equipment such as a goods management system for identifying multiply arrayed goods, etc. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation of co-pending U.S. patent application Ser. No. 13/223,909, entitled “Valve for Hydraulic Fracturing Through Cement Outside Casing”, filed Sep. 1, 2011, in the name of the inventors Michael Sommers and Stephen Jackson. The earlier effective filing date of that application is hereby claimed pursuant to 35 U.S.C. §120. That application is also hereby incorporated by reference for all purposes as if set forth herein verbatim.
BACKGROUND
[0002] 1. Field of the Invention
[0003] This invention is directed to a valve utilized for hydraulically fracturing multiple zones in an oil and gas well without perforating the cement casing. A relatively new oil/gas well completion method involves the use of a valve that is installed as pan of the easing string of the well and provides for cement flow within the casing when the valve element is in a closed position and allows for axial flow of fracturing fluid through the cement casing to fracture the formation near the valve. The invention disclosed herein is an improved valve used in this process.
[0004] 2. Description of Related Art
[0005] Current designs for valves used in the completion method disclosed above are prone to failure because cement or other debris interferes with the opening of the valve after the cementing process has been completed. Portions of the sliding sleeve or pistons commonly used are exposed to either the flow of cement or the cement flowing between the well bore and the casing string.
SUMMARY OF THE INVENTION
[0006] The valve according to the invention overcomes the difficulties described above by isolating a sliding sleeve between an outer housing and an inner mandrel. A rupture disk in the inner mandrel ruptures at a selected pressure. Pressure will then act against one end of the sliding sleeve and shift the sleeve to an open position so that fracturing fluid will be directed against the cement casing. The sliding sleeve includes a locking ring nut to prevent the sleeve from sliding hack to a closing position.
BRIEF DESCRIPTION OF DRAWINGS
[0007] FIG. 1 is a side view of the valve according to one embodiment of the invention.
[0008] FIG. 2 is a cross sectional view of the valve in the closed position taken along line 2 - 2 of FIG. 1
[0009] FIG. 3 is a cross sectional view of the valve taken along line 3 - 3 of FIG. 2
[0010] FIG. 4 is a cross sectional view of the sliding sleeve
[0011] FIG. 5 is a cross sectional view of the locking ring holder
[0012] FIG. 6 is a cross sectional view of the locking ring
[0013] FIG. 7 is an end view of the locking ring
[0014] FIG. 8 is a cross sectional view of the valve in the open position
[0015] FIG. 9 is an enlarged view of the area circled in FIG. 8 .
DETAILED DESCRIPTION
[0016] As shown in FIG. 1 , an embodiment of valve 10 of the invention includes a main housing 13 and two similar end connector portions 11 , 12 .
[0017] Main housing 13 is a hollow cylindrical piece with threaded portions 61 at each end that receive threaded portions 18 of each end connector. End connectors 11 and 12 may be internally or externally threaded for connection to the casing string. As show in FIG. 2 , main housing 13 includes one or more openings 19 , which are surrounded by a circular protective cover 40 . Cover 40 is made of a high impact strength material.
[0018] Valve 10 includes a mandrel 30 which is formed as a hollow cylindrical tube extending between end connectors 11 , 12 as shown in FIG. 2 . Mandrel 30 includes one or more apertures 23 that extend through the outer wall of the mandrel. Mandrel 30 also has an exterior intermediate threaded portion 51 . One or more rupture disks 41 , 42 are located in the mandrel as shown in FIG. 3 . Rupture disks 41 , 42 are located within passageways that extend between the inner and outer surfaces of the mandrel 30 . Annular recesses 17 and 27 are provided in the outer surface of the mandrel for receiving suitable seals.
[0019] Mandrel 30 is confined between end connectors 11 and 12 by engaging a shoulder 15 in the interior surface of the end connectors. End connectors 11 and 12 include longitudinally extending portions 18 that space apart outer housing 13 and mandrel 30 thus forming a chamber 36 . Portions 18 have an annular recess 32 for relieving a suitable seal. A sliding sleeve member 20 is located within chamber 36 and is generally of a hollow cylindrical configuration as shown in FIG. 4 . The sliding sleeve member 20 includes a smaller diameter portion 24 that is threaded at 66 . Also it is provided with indentations 43 that receive the end portions of shear pins 21 . Sliding sleeve member 20 also includes annular grooves 16 and 22 that accommodate suitable annular seals.
[0020] A locking ring holder 25 has ratchet teeth 61 and holds locking ring 50 which has ratchet teeth 51 on its outer surface and ratchet teeth 55 on its inner surface shown in FIG. 9 . Locking ring 50 includes an opening at 91 as shown in FIG. 7 which allows it to grow in diameter as the sliding sleeve moves from the closed to open position.
[0021] Locking ring holder 25 has sufficient diameter clearance so that the locking ring can ratchet on the mandrel ratcheting teeth 63 yet never loose threaded contact with the lock ring holder. Locking ring holder 25 is threaded at 26 for engagement with threads 24 on the mandrel. Locking ring holder 25 also has a plurality of bores 46 and 62 for set screws, not shown.
[0022] In use, valve 10 may be connected to the casing string by end connectors 11 , 12 . One or more valves 10 may be incorporated into the easing string. After the casing string is deployed within the well, cement is pumped down through the casing and out the bottom into the annulus between the well bore and the casing as typical in the art. After the cement flow is terminated, a plug or other device is pumped down to wipe the casing and valve clean of residual cement. When the plug or other device has latched or sealed in the bottom hole assembly, pressure is increased to rupture the rupture disk at a predetermined pressure. The fluid pressure will act on sliding sleeve member 20 to cause the shear pins to break and then to move it downward or to the right as shown in FIG. 7 . This movement will allow fracing fluid to exit via opening 23 in the mandrel and openings 19 in the outer housing. The fracing fluid under pressure will remove protective cover 40 and crack the cement casing and also fracture the foundation adjacent to the valve 10 .
[0023] Due to the fact that the sliding sleeve member 20 is mostly isolated from the cement flow, the sleeve will have a lessor tendency to jam or require more pressure for actuation.
[0024] In the open position, locking ring 50 engages threads 63 on the mandrel to prevent the sleeve from moving back to the closed position.
[0025] A vent 37 is located in the outer housing 13 to allow air to exit when the valve is being assembled. The vent 37 is closed by a suitable plug after assembly.
[0026] Although the present invention has been described with respect to specific details, it is not intended that such details should be regarded as limitations on the scope of the invention, except to the extent that they are included in the accompanying claims. | A valve for use in fracing through cement casing in a well allows for flow of cement down the well during the cementing process and in the open position allows for fracing fluid to be directed through the cement casing for fracturing the formation adjacent the valve. The valve is constructed so as to reduce the likelihood of the valve to jam as a result of cement or other foreign material. | 4 |
BACKGROUND OF THE INVENTION
This invention relates generally to semipermeable membranes and, more particularly, to a membrane made from a condensation polymer which has a molecular weight distribution that provides for enhanced physical properties and is particularly suited for use as an ultrafiltration membrane.
The term "ultrafiltration" as used in this application is intended to encompass microfiltration, nanofiltration, ultrafiltration, reverse osmosis and gas separation. Ultrafiltration may be performed using a variety of physical layouts which are well known to those skilled in the art and include both spiral wound and tubular modules.
Many applications of ultrafiltration technology involve food processing where sanitary conditions must be maintained at all times. This necessitates periodic cleaning with relatively harsh chemicals such as (by way of example only) chlorine containing compounds, other oxidizing agents, acids, alkalies and surfactants. These chemicals tend to degrade the membrane material and the ability of the membrane to withstand these chemicals is, in many cases, the determining factor in the useful life of the membrane.
Known materials for use in forming ultrafiltration membranes include many commercially available polymers such as polyether sulfone, polysulfone, polyarylether sulfones, polyvinylidene fluoride, polyvinyl chloride, polyketones, polyether ketones, polytetrafluoro ethylene, polypropylene and polyamides. The foregoing polymers differ widely in their physical properties and the particular material selected is based upon the properties necessary to support a particular use. While the higher molecular weight "chain" polymers such as polyvinyl chloride and polytetrafluoro ethylene exhibit superior resistance to degradation from cleaning chemicals, they also have undesirable attributes which eliminate them from consideration as membrane materials for certain applications. On the other hand, the lower molecular weight "condensation" polymers which exhibit certain desirable properties particularly suited for ultrafiltration applications are not as durable and have a short and unpredictable service life when exposed to the types of chemicals aforementioned.
SUMMARY OF THE PRESENT INVENTION
The present invention comprises an ultrafiltration membrane which is formed from a condensation polymer that has been modified to have a molecular weight distribution that is higher than would otherwise be the case or alternatively has a relatively low percentage of low molecular weight fraction present in the polymer or, preferably, both of these traits. Known additives for imparting desired physical properties to the membrane can be incorporated into the formulation.
OBJECTS OF THE INVENTION
It is therefore an object of the present invention to provide an ultrafiltration membrane which is formed from a condensation polymer and thus has the desired properties of such a polymer but which has been modified to provide an altered molecular weight distribution and as a result thereof has improved physical properties.
As a corollary to the foregoing object, an aim of this invention is to provide an ultrafiltration membrane particularly suited for use in food processing equipment which has improved resistance to degradation from cleaning compositions used in such applications.
One of the other aims of my invention is to provide an improved ultrafiltration membrane having superior resistance to chemical degradation which also exhibits the desired physical properties of membranes heretofore formed from condensation polymers of the type well known to those skilled in the art.
One of the important objectives of this invention is to provide an ultrafiltration membrane having a longer and more predictable service life when used in food processing equipment and other applications where harsh chemicals are employed to clean the equipment than has been possible with membranes known in the prior art.
Still another object of the invention is to provide an improved ultrafiltration membrane which is compatible with existing membrane additives used to impart desired properties to the membrane such as hydrophilicity and uniform pore size.
It is also an important object of this invention to provide an ultrafiltration membrane which exhibits superior resistance to degradation by harsh cleaning chemicals and also has a more uniform pore size distribution than prior constructions, thus improving performance of the membrane.
As a corollary to the object next above set forth, an aim of the invention is to provide an ultrafiltration membrane having improved filtration efficiency in comparison to other membranes typically employed in the food processing and similar industries.
Other objects of the invention will be made clear or become apparent from the following specification and claims.
DETAILED DESCRIPTION OF THE INVENTION
Synthetic polymers of the type useful in the present invention are those formed from the condensation of one or more different monomers. The polymers thus formed typically have different weight distributions among the polymer chains because of varying quantities of the molecules which make up the chains. Condensation polymers particularly suited for forming ultrafiltration membranes have relatively low number average molecular weights (e.g. within the range of about 25,000 to about 63,000) in comparison to chain polymers, i.e. those made by chain polymerization of reactive monomers (typical molecular weights for these polymers are from about 100,000 to about 1,000,000).
For purposes of the present specification and claims, number average molecular weight (MN) is defined as follows: ##EQU1## Weight average molecular weight (MW) is defined as follows: ##EQU2##
Where N i is the number of molecules having molecular weight of M i (i=1, 2, 3, . . . r), where r is an integer.
A typical condensation polymer of the type useful in the present invention will have an unmodified number average molecular weight (MN) of about 63,000 or less and a weight average molecular weight (MW) of from about 100,000 to about 160,000. The weight fraction (WF) of molecules with a molecular weight of less than 50,000 will typically be around 30% to 35% (although some known polymers of the prior art which are useful in membrane formation have WFs as low as just under 16% or MNs slightly above 62,000 these are generally not preferred for the present invention).
Suitable condensation polymers include polyether sulfone, polysulfone and polyarylether sulfones. Polyether sulfone is represented by the formula: ##STR1##
Polyether sulfones which are useful as starting materials for the present invention will have MNs in the range of approximately 39,000 to 50,900 and WFs in the range of 22 to 34%.
Polysulfones useful in the present invention are represented by the formula: ##STR2##
Suitable polysulfones for carrying out the present invention will have an MN of 43,000 to 54,000 and a WF=19.8 to 23%.
Polyarylether sulfones are represented by the formulas: ##STR3## where A=1,4-phenylene or 4,4'-biphenylene,
C=1,4-phenylene or 4,4'-biphenylene, and
n=2 to 300.
The polyarylether sulfones will generally have an MN=50,800 to 62,500 and a WF=17 to 21.25%. Suitable polyarylether sulfones include poly(oxy-1,4-phenylene sulfonyl-1,4-phenyleneoxy-4,4'-biphenylene) and poly(oxy-1,4-phenylene sulfonyl-1,4-phenyleneoxy-4,4'-biphenyleneoxy-1,4-phenylene sulfonyl-1,4-phenyleneoxy-1,4-phenylene) having the following respective formulas: ##STR4##
It has been discovered that when these condensation polymers are modified to have a number average molecular weight of about 59,000 or greater or a weight fraction of molecules with a molecular weight of not more than 50,000 which is no more than about 19% of the total of all molecules in the polymer, or both such properties, greatly superior properties for an ultrafiltration membrane formed from such polymers result.
The preferred method of modifying the molecular weight distribution of the polymer is through fractional precipitation although other known techniques for concentrating a high molecular weight fraction of a polymer, such as membrane separation and size exclusion chromatography may be utilized.
The following examples illustrate the principle of modifying the molecular weight distribution of a condensation polymer to impart the desired properties discussed above.
EXAMPLE 1
300g. of a polyether sulfone polymer [MN=39,100; MW=156,000 and WF 33.96% (as determined by gel permeation chromatography)]was dissolved in 1.2 liters of N-methyl pyrrolidone (NMP) and then mixed in a blender. 1.9 1 of 80% (v/v) of NMP in water was then added. 190 ml of 50% (v/v) NMP in water was then added to precipitate the high molecular weight fraction of the polymer. The precipitate was collected as a gel. This gel was redissolved in 0.75 liters of NMP and a high molecular weight fraction was again precipitated by adding 400 ml of 60% (v/v) solution of NMP in water. The precipitated gel was then redissolved in 750 ml of NMP solvent and a third high molecular weight fraction was precipitated by adding 400 ml of the 60% (v/v) solution of NMP. Again, the gel was separated and redissolved in the 0.75 liters of NMP solvent and then reprecipitated a final time by adding 400 ml of the 60% NMP in water solution. This precipitate was dissolved in 750 ml of NMP and gelled by adding dropwise to water.
The modified polymer prepared as described above was washed several times with water and then dried for 24 hours at 150 degrees Celsius. The modified polymer had a molecular weight of 183,000 (as determined by gel permeation chromatography (GPC)), its MN=91,700 (as determined using GPC) and a WF=10.53 % (as measured by GPC).
The modified polymer was blended with 5% (w/w) of polyvinylpyrrolidone (PVP) in NMP. The PVP was present in two parts of approximately equal quantity, the first having a MN of 150,000 and a molecular weight (MW) of 612,000 and a second having an MN of 271,000 and an MW of 906,000. The PVP additive improves the hydrophilicity of the completed membrane.
The modified polymer blended with PVP was dissolved in a mixture containing N-methyl pyrrolidone and sulfolane. A suitable pore former, such as ethylene glycol or lithium chloride, both well known to those skilled in the art, was added in a quantity to present a concentration of from 1 to about 10 % (w/v) of the pore former in the final product. The amount of pore former added was determined by the degree of porosity desired in the final product. The admixture was thoroughly blended and after degassing using conventional techniques was cast on a substrate such as a nonwoven fabric. A doctor blade was employed to disperse the casting in a uniform manner at a thickness of approximately 10 mils. The smoothed product was immediately gelled by immersion in a bath of cold water and N-methyl pyrrolidone [NMP being present from 0-70% (v/v)] for 15 seconds followed by continuous water washing for approximately 24 hours to remove all extraneous extractable contaminates.
Chlorine resistance of a membrane prepared according to Example 1 was assessed by soaking samples in a chlorine bath and then removing the samples, folding same and applying 30 p.s.i. The procedure was repeated with the samples being examined under a microscope to determine the presence of cracks. The results are summarized in Table 1 following:
TABLE I______________________________________DEGREE OF CHLORINE ATTACK VERSUSMEMBRANE EMBRITTLEMENT-EXAMPLE 1POLYMERS Time of No. of FoldsMembrane Exposure at 30 psi untilPolymer Material (hours) crack______________________________________Polyether sulfone.sup.1 4 >20Polyether sulfone.sup.1 6 4Polyether sulfone.sup.2 4 >20Polyether sulfone.sup.2 5 4Unmodified 1 1Polyether sulfone.sup.3______________________________________ note: .sup.1 prepared according to Example 1. Test sample had MN = 94,600, WF = 7.67%. Blended with PVP having MN = 150,000 and MW = 612,000 .sup.2 prepared according to Example 1. Test sample had MN = 94,600, WF = 7.65%. Blended with PVP having MN = 271,000, MW = 906,000 .sup.3 MN = 47,000, WF = 30%
Efficiency of the membrane prepared according to the Example 1 was assessed both before and after chlorine exposure. Samples were placed in a cross flow flat test cell unit and tested for water and 8% whey flux at 40 degrees Celsius. Whey permeate was analyzed for protein using tricholoroacetic acid turbidity test and percent rejection of whey protein by each membrane was calculated. The results are summarized in Table 2.
TABLE 2______________________________________MEMBRANE FILTRATION EFFICIENCY--EXAMPLE 1 POLYMERSMembranePolymer Water Flux Whey Flux Whey ProteinMaterial (gal/ft.sup.2 -day) (gal/ft.sup.2 -day) Rejection (%)______________________________________Polyether 167 29 99.98sulfone.sup.1Unmodified 305 30 99.93Polyethersulfone.sup.2______________________________________ note: .sup.1 see note 1, table 1 .sup.2 see note 3, table 1
EXAMPLE 2
300g. of polyether sulfone resin (MN=45,000; MW=107,000 and WF=30.4%) was dissolved in 1.2 liters of N-methyl pyrrolidone (NMP) and then mixed in a blender. The mixture was then diluted with 1.9 liters of 80% (v/v) NMP in water followed by two solvent precipitations as set forth in Example 1. The precipitate was then dissolved in 750 ml of NMP (per example 1) followed by adding dropwise to water to precipitate the final product. The precipitate was washed with water to remove any NMP and then dried for 24 hours at 150 degrees Celsius.
The modified polymer had an MN=59,800 an MW=129,000 and a WF=17%. The modified polymer was blended with 5% (w/w) polyvinylpyrrolidone (per example 1) having an MN=150,000 and a MW=612,000 and then cast and hardened in the manner discussed in Example 1 to present a usable membrane.
Chlorine resistance of membrane prepared according to Example 2 was assessed by soaking samples in a chlorine bath and then removing the samples, folding same and applying 30 p.s.i. pressure. The procedure was repeated with the samples being examined under a microscope to determine the presence of cracks. The results are summarized in Table 3 following:
TABLE 3______________________________________DEGREE OF CHLORINE ATTACK VERSUSMEMBRANE EMBRITTLEMENT--EXAMPLE 3POLYMERS Time of No. of FoldsMembrane Exposure 30 psi untilPolymer Material (hours) crack______________________________________Polyether sulfone.sup.1 4 >20Polyether sulfone.sup.1 5 18Unmodified 1 1Polyether sulfone.sup.2______________________________________ note: .sup.1 Prepared according to Ex. 2. Test sample had MN = 59,800, MW = 129,000 and WF = 17%. Blended with PVP having MN = 150,000 and MW = 612,000. .sup.2 see note 3, table 1
EXAMPLE 3
In this example, 300 g of polyether sulfone resin having an MN=45,000, an MW=107,000 and a WF=30.4 % was dissolved in 1.2 1 of N-methyl pyrrolidone. Four solvent precipitations were carried out according to the procedure set forth in Example 1. The final product had an MN=94,600, an MW=161,000 and a WF=11.5%.
The modified polymer was blended with 5% (w/w) of one of two polyethyl oxazolines. The first had an MN=33,000 and an MW=72,000. The second had an MN=159,000 and an MW=370,000. The polymers were combined with a suitable pore former and cast according to the procedure previously described.
Chlorine resistance of membranes prepared according to Example 3 was assessed by soaking samples in a chlorine bath and then removing the samples, folding same and applying 30 p.s.i. The procedure was repeated with the samples being examined under a microscope to determine the presence of cracks. The results are summarized in Table 4 following:
TABLE 4______________________________________DEGREE OF CHLORINE ATTACK VERSUSMEMBRANE EMBRITTLEMENT--EXAMPLE 3POLYMERS Time of No. of FoldsMembrane Exposure 30 psi untilPolymer Material (hours) crack______________________________________Polyether sulfone.sup.1 3.5 >20Polyether sulfone.sup.1 5.0 10Polyether sulfone.sup.2 5.0 >20Polyether sulfone.sup.2 7.0 10Polyether sulfone.sup.3 4.0 >20Polyether sulfone.sup.3 5.0 6Unmodified 1.0 2Polyether sulfone.sup.4______________________________________ note: .sup.1 Prepared according to Example 3. Test sample had MN = 94,000, MW = 161,000 and WF = 11.15% Blended with 5% polyethyl oxazoline MN = 33,000 and MW = 72,000 .sup.2 Prepared according to Example 3. Test sample had MN = 94,000, MW = 161,000 and WF = 11.15%. Blended with 5% polyethyl exazoline MN = 159000 and MW = 370000 .sup.3 Polyether sulfone MN = 94,000, WF = 11.65% blended with PVP MN = 271,000, MW = 906,000 .sup.4 Polyether sulfone MN = 45,000, MW = 107,000. WF = 30% blended wit PVP MN = 271,000 and MW = 906,000
While the invention encompasses any condensation polymer that is capable of being formed into an ultrafiltration membrane, a preferred group of polymers is that consisting of polysulfone, polyether sulfone and polyarylsulfones such as poly(oxy-1,4-phenylene sulfonyl-1,4-phenyleneoxy-4,4'-biphenylene) and poly(oxy-1,4-phenylene sulfonyl-1,4-phenyleneoxy-4,4'-biphenyleneoxy-1,4-phenylene sulfonyl-1,4-phenyleneoxy-1,4-phenylene). The most preferred polymer for use in the present invention is polyether sulfone.
It is to be understood that the modified polymers according to the present invention may be formed into copolymers with other known membrane forming materials including copolymers of the named condensation polymers with each other and copolymers and mixtures of other unmodified polymers.
The membrane materials according to the invention may also incorporate other known membrane additives such hydrophilicity enhancers, e.g. hydrophilic urethane and polyoxazolines.
The hardened membrane material may be processed in a conventional matter to form the final membrane including the use of pore formers or to achieve the desired end product. Suitable pore formers include low molecular weight organic compounds, inorganic salts and organic polymers, for example vinyl pyrrolidone/dimethyl aminomethyl methacrylate; polyoxazolines such as poly(2-ethyl-I-oxazoline) and poly(2-methyl-2-oxazoline); copolymers of polysulfone such as polysulfone-b-polyethylene oxide and polysulfone-b-polyvinyl pyrrolidone; and copolymers of polyether sulfone such as polyether sulfone-b-polyethylene oxide and polyether sulfone-b-polyvinyl pyrrolidone.
Other suitable pore formers include low molecular weight organic acids such as acetic acid, propionic acid and sulfolane and inorganic salts such as lithium chloride, lithium bromide, lithium fluoride, sodium bicarbonate, sodium carbonate and sodium acetate. Organic polymers such as poly(N-vinyl pyrrolidone) and poly(ethylene glycol) may also be used as pore formers.
From the foregoing it will be seen that this invention is one well adapted to attain all ends and objects hereinabove set forth together with the other advantages which are obvious and which are inherent in the structure.
It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.
Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth is to be interpreted as illustrative and not in a limiting sense. | The subject of this invention is a novel polymeric composition useful in membrane technology such as microfiltration, nanofiltration, ultrafiltration, reverse osmosis and gas separation. The composition is formed by taking a known condensation polymer such as polyether sulfone, polysulfone or a polyarylether sulfone and modifying it to change the molecular weight distribution. The useful polymers of the invention will have an unmodified number average molecular weight of about 63,000 or less and weight fraction of molecules with a molecular weight of 50,000 or less in the range of 30 to 35%. Utilizing fractional precipitation or other known techniques for concentrating a high molecular weight fraction of a polymer the polymers are modified to have a number average molecular weight of a least 59,000 or a weight fraction of molecules with a molecular weight of 50,000 or less of not more than 19%. Superior resistance to cracking and other forms of membrane degradation results from using the polymer compositions of the present invention in filtration applications. | 1 |
TECHNICAL FIELD
[0001] The technical field relates to a door panel limiting method and a planar door stopper, and more particularly to the planar door stopper normally and flatly disposed on a floor and framed around the corners and the periphery of the bottom of a door panel or extended across the thickness of an outer side of the bottom of the door panel.
BACKGROUND
[0002] In general, a conventional door stopper limits the position of a door panel by a magnetic attraction method, and the door stopper is in form of a magnetic lug having a magnet at an end of the door stopper. When use, the door stopper is fixed to a wall behind the door panel, and an iron plate is installed to the backside of the door panel. When the door panel is opened, the iron plate at the backside of the door panel is attracted and attached onto the magnet of the door stopper to maintain the door panel in an open status.
[0003] However, the conventional door stopper installed onto a wall has the following problems: Special screws or anchors are required for the installation in order to fix the magnetic lug, and thus causing inconvenience to construction and damaging the wall, and the magnetic lug is an obvious projection on the wall, and thus the magnetic lug may injure a person's leg by collision easily. In addition, the power of limiting the door panel provided for attaching the door panel simply by the magnetic attraction method is insufficient, so that a large-area door panel may be detached from the magnetic lug easily when the wind is relatively large.
[0004] Among the advanced conventional door stoppers, the door stoppers are normally and flatly disposed on a floor, and such door stopper has a tab with induced magnetism and swayable upward, and a magnet installed at the bottom of the door panel for magnetically attracting the tab. For instance, Japanese Unexamined Patent Application No. 2001-159265 is one of the typical embodiments of such door stoppers.
[0005] However, the door stopper installed to the floor has to make a groove under the door panel and install a magnet into the groove, so that the tab of the door stopper on the floor is movably embedded into the groove. Alternatively, a hardware accessory having a groove is installed under the door panel, and if the groove of the hardware accessory is too narrow, then the tab of the door stopper will not be latched securely. On the other hand, if the groove is too deep, then the thickness of the hardware accessory will be too large, so that the door panel with the bottom too close to the floor cannot be installed. Although the aforementioned two embodiments can reduce the chance of getting injured in a collision, yet they still have the drawbacks of causing inconvenience to construction and damaging the door panel.
[0006] In addition, the tab of the aforementioned door panel is obliquely embedded into the groove, and thus just an end of the tab is attracted to the magnet in the groove. The smaller the magnetic attraction area, the less the stopping effect. As a result, the tab of the door stopper may fall off easily in situations such as strong wind or collision to the door panel, and there is an issue of disabling the door stopper easily.
[0007] In view of the aforementioned problems, the disclosure of this disclosure based on years of experience in the related industry to conduct extensive researches and experiments, and finally provided a feasible solution to overcome the problems of the prior art.
SUMMARY
[0008] Therefore, it is a primary objective of this disclosure to provide a planar door stopper, particularly a planar door stopper normally and flatly disposed on a floor, magnetically attracted by a surface area, and framed around the corners and the periphery of the bottom of the door panel or extended across the thickness of an outer side of the bottom of the door panel, so as to overcome the aforementioned drawbacks of the prior art, including the inconvenient construction of the conventional door stoppers, and the problems of damaging the door panel, and resulting in a small magnetic attraction area and a poor stopping effect.
[0009] To achieve the aforementioned and other objectives, the planar door stopper of this disclosure comprises a fixed plate fixed to a floor; a limiting frame plate pivotally installed on the fixed plate and upwardly swayable with respect to the floor; a first magnetic attraction plate, installed on the limiting frame plate, for driving the limiting frame plate to sway upward with respect to the floor by magnetic attraction; and a limiting slot, formed on the limiting frame plate, and framed around the corners and periphery of the door panel or extended across the thickness of an outer side of the bottom of the door panel when swaying the limiting frame plate upward with respect to the floor.
[0010] In an embodiment, the door panel includes a second magnetic attraction plate installed at the bottom of the door panel and capable of producing a magnetic attraction with the first magnetic attraction plate.
[0011] In the aforementioned planar door stopper, the fixed plate is flatly fixed to floor, and the limiting frame plate and the first magnetic attraction plate are normally and flatly disposed on floor and stacked on the fixed plate. When the door panel is opened to a position above the limiting frame plate, the second magnetic attraction plate of the door panel and the first magnetic attraction plate of the limiting frame plate produce a magnetic attraction to drive the first magnetic attraction plate to sway the limiting frame plate upwardly, so that the first magnetic attraction plate is magnetically attached onto the second magnetic attraction plate in a planar contact manner, while the limiting slot of the limiting frame plate is swayed upward and framed around the corners and the periphery of the bottom of the door panel or extended across the thickness of an outer side of the bottom of the door panel, so as to achieve the effect of limiting the door panel at an opening position.
[0012] To release the limitation of the door panel, a user simply steps on the edge of the limiting frame plate to resume the limiting frame plate and the first magnetic attraction plate to their position of being flatly attached onto the floor, since the limiting slot of the limiting frame plate is framed around the corners and periphery of the bottom of the door panel or extended across the thickness of an outer side of the bottom of the door panel, and the edge of the limiting slot of the limiting frame plate is slightly protruded from the door panel. Therefore, the limitation of the door panel can be released, and the door panel can be rotated and opened freely to provide a very convenience use.
[0013] In addition, the fixed plate is fixed to the floor and disposed at a position below the moving door panel while opening the door panel, and the second magnetic attraction plate is fixed to the bottom of the door panel without damaging the wall or door panel during construction, so as to provide a simple and easy construction. In addition, the first magnetic attraction plate and the second magnetic attraction plate may be magnetically attached to each other in a planar contact manner to increase the magnetic attraction area significantly and prevent the first magnetic attraction plate and the second magnetic attraction plate from falling out, and also to prevent the limiting frame plate from falling out from the bottom of the door panel. In the meantime, the limiting slot of the limiting frame plate is provided and framed onto the corners of the bottom of the door panel or extended across the thickness of an outer side of the bottom of the door panel to achieve the effects of stopping the door panel from moving further, and improving the stopping effect of the door stopper.
[0014] Embodiments of this disclosure are described below:
[0015] According to the aforementioned structural characteristics, the first magnetic attraction plate may be a magnetic plate or a magnetic metal plate, and the second magnetic attraction plate may also be a magnetic plate or a magnetic metal plate. For example, if the first magnetic attraction plate is a magnetic plate, the second magnetic attraction plate may be a magnetic metal plate; or if the first magnetic attraction plate is a magnetic metal plate, the second magnetic attraction plate may be a magnetic plate. Of course, the first magnetic attraction plate and the second magnetic attraction plate may be magnetic plates with opposite magnetic poles.
[0016] According to the aforementioned structural characteristics, the limiting slot is substantially in a rectangular shape or U-shape, and the limiting slot has a width greater than the thickness of the door panel.
[0017] According to the aforementioned structural characteristics, the first magnetic attraction plate has an inner edge pivoted to an inner periphery of the limiting slot, and the fixed plate has a link plate pivoted to the fixed plate and capable of swaying upward with respect to the floor, and the first magnetic attraction plate has an end pivoted to the limiting frame plate and the other end pivoted to the link plate, so that the linkage of the mutually pivoted fixed plate, link plate, first magnetic attraction plate, limiting frame plate defines a four-link-rod assembly. Therefore, if the first magnetic attraction plate is magnetically attracted by the second magnetic attraction plate, the first magnetic attraction plate will be moved upwardly in a horizontal moving manner while driving the limiting frame plate and the link plate to move upward, so that the first magnetic attraction plate is still parallel to the floor and the bottom of the door panel during the whole moving process, so that the first magnetic attraction plate is parallel to the bottom of the door panel and upwardly attached onto a surface of the second magnetic attraction plate to provide a stable magnetic attraction effect.
[0018] This disclosure further provides a door panel limiting method comprising the steps of: installing a planar door stopper to a floor and the planar door stopper being configured to be corresponsive to a moving path of a door panel, and the planar door stopper including a first magnetic attraction plate and a limiting frame plate linked to the first magnetic attraction plate, and an end of the limiting frame plate being pivoted to the planar door stopper and swayable upward, and the other end of the limiting frame plate having a limiting slot with a width greater than the thickness of the door panel; and installing a second magnetic attraction plate at the bottom of the door panel and the second magnetic attraction plate being configured to be corresponsive to the first magnetic attraction plate, such that when the door panel is opened, the attraction of the second magnetic attraction plate exerted to the first magnetic attraction plate drives the first magnetic attraction plate and the limiting frame plate to turn and move upward, and the limiting slot of the limiting frame plate is framed around the corners and the periphery of the door panel or extended cross an outer side of the bottom of the door panel, so as to limit the door panel at an opening position.
[0019] In the aforementioned method, the first magnetic attraction plate has an inner end pivoted to an inner edge of the limiting slot, and the planar door stopper has a fixed plate disposed at the bottom of the planner door stopper and flatly fixed onto the floor, and an end of the limiting frame plate is pivoted to an outer end of the fixed plate, and an inner end of the fixed plate is further pivoted to a link plate, and the other end of the link plate away from the fixed plate is pivoted to an outer end of the first magnetic attraction plate, so that a four link rod structure is formed among the mutually pivoted fixed plate, link plate, first magnetic attraction plate, and limiting frame plate, and when the first magnetic attraction plate is magnetically attracted by the second magnetic attraction plate, the first magnetic attraction plate is capable of moving parallel to the floor and displacing upward with respect to the bottom of the door panel, while driving the limiting frame plate and the link plate to sway upward, and the first magnetic attraction plate is capable of being magnetically attached onto a surface of the second magnetic attraction plate in a planar contact manner.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a perspective view of a first preferred embodiment of this disclosure;
[0021] FIG. 2 is a schematic perspective view showing a using status of the first preferred embodiment of this disclosure as depicted in FIG. 1 ;
[0022] FIG. 3 is an exploded view of the first preferred embodiment of this disclosure as depicted in FIG. 1 ;
[0023] FIG. 4 is a sectional view of the first preferred embodiment of this disclosure as depicted in FIG. 1 ;
[0024] FIG. 5 is a sectional view of the first preferred embodiment of this disclosure as depicted in FIG. 2 ;
[0025] FIG. 6 is a schematic perspective view showing a using status of the first preferred embodiment of this disclosure as depicted in FIG. 2 ;
[0026] FIG. 7 is a sectional view of the first preferred embodiment of this disclosure as depicted in FIG. 6 ;
[0027] FIG. 8 is a schematic perspective view showing a using status of a second preferred embodiment of this disclosure; and
[0028] FIG. 9 is a schematic side view showing a using status of the second preferred embodiment of this disclosure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] The technical content of this disclosure will become apparent with the detailed description of preferred embodiments and the illustration of related drawings as follows.
[0030] With reference to FIGS. 1 to 5 for a planar door stopper in accordance with a preferred embodiment of this disclosure, the planar door stopper comprises a fixed plate 1 , a limiting frame plate 2 and a first magnetic attraction plate 3 . The fixed plate 1 may be fixed to the floor by adhesion or a locking method, and an end of the limiting frame plate 2 is pivoted to the fixed plate 1 through a first shaft 51 , so that the limiting frame plate 2 can be swayed upwardly with respect to the floor.
[0031] The limiting frame plate 2 has a limiting slot 21 with a width greater than the thickness of the door panel, and the first magnetic attraction plate 3 is installed onto the limiting frame plate 2 and an inner side of the magnetic attraction plate 3 is pivoted to the inner edge of the limiting slot 21 , so that the first magnetic attraction plate 3 can sway the limiting frame plate 2 to move upwardly with respect to the floor by magnetic attraction, and the limiting slot 21 is swayed together with the limiting frame plate 2 to move upwardly with respect to the floor. In FIGS. 1 to 7 , the limiting slot 21 is substantially in a rectangular shape, so that the limiting slot 21 has an effect of limiting the door panel by the corners 71 of the bottom of the door panel 7 . In another embodiment, the limiting slot 21 may be U-shaped as shown in FIGS. 8 and 9 and extended across the outside thickness of the door panel 7 to limit the bottom of the door panel 7 .
[0032] In FIGS. 6 and 7 , the corner 71 of the door panel 7 further includes a second magnetic attraction plate 6 capable of producing magnetic attraction with the first magnetic attraction plate 3 . In FIGS. 8 and 9 , the second magnetic attraction plate 6 is not necessary to be installed at the corner 71 of the bottom of the door panel 7 . As long as the bottom of the door panel 7 is configured to be corresponsive to the first magnetic attraction plate 3 and capable of attracting the first magnetic attraction plate 3 to move upward.
[0033] In the embodiment, the first magnetic attraction plate 3 is a magnetic plate or a magnetic metal plate, and the second magnetic attraction plate 6 is also a magnetic plate or a magnetic metal plate. Specifically, if the first magnetic attraction plate 3 is a magnetic plate, the second magnetic attraction plate 6 may be a magnetic metal plate. Alternatively, if the first magnetic attraction plate 3 is a magnetic metal plate, the second magnetic attraction plate 6 may be a magnetic plate, or both of the first magnetic attraction plate 3 and the second magnetic attraction plate 6 are magnetic plates with opposite magnetic poles.
[0034] In FIG. 3 , the fixed plate 1 is pivoted to a link plate 4 through a second shaft 52 , and the limiting frame plate 2 and the link plate 4 are pivoted to both ends of the fixed plate 1 respectively, so that the link plate 4 can be swayed upwardly with respect to the floor. The first magnetic attraction plate 3 has an end pivoted to an inner edge of the limiting slot 21 by a third shaft 53 and the other end pivoted to the link plate 4 by a fourth shaft 54 , and both ends of the first magnetic attraction plate 3 are pivoted to the limiting frame plate 2 and the link plate 4 respectively. With the pivoting relationship between the aforementioned components, the linkage among the fixed plate 1 , the limiting frame plate 2 , the first magnetic attraction plate 3 and the link plate 4 defines a four-link-rod assembly.
[0035] In FIGS. 4 and 5 , the fixed plate 1 is flatly fixed to the floor during use, and the link plate 4 together with the fixed plate 1 may be fixed to the floor, and the limiting frame plate 2 and the first magnetic attraction plate 3 are normally and flatly disposed on the floor and stacked on the fixed plate 1 and the link plate 4 .
[0036] In FIGS. 6 and 7 , when the door panel 7 is opened to a position above the limiting frame plate 2 , the second magnetic attraction plate 6 of the door panel 7 and the first magnetic attraction plate 3 of the limiting frame plate 2 produce magnetic attraction to drive the first magnetic attraction plate 3 to move the limiting frame plate 2 and the link plate 4 synchronously upward.
[0037] Now, the four-link-rod linkage of the aforementioned components is capable of maintaining the first magnetic attraction plate 3 to be parallel to the floor and the bottom of the door panel 7 in the whole moving process, so that the first magnetic attraction plate 3 is attached to the surface of the second magnetic attraction plate 6 in the manner of being parallel to the bottom of the door panel 7 , so as to provide stable magnetic attraction and magnetically attract the first magnetic attraction plate 3 to the second magnetic attraction plate 6 . In the meantime, the limiting slot 21 of the limiting frame plate 2 is swayed upwardly, so that the limiting slot 21 as shown in FIGS. 6 and 7 are framed at the corners 71 at the bottom of the door panel 7 or the outer periphery of the door panel 7 . Alternatively, the limiting slot 21 is extended across an outer side of the thickness of the bottom of the door panel 7 as shown in FIGS. 8 and 9 , so that even if there is a strong wind or a person colliding with the door panel 7 , the limiting slot 21 framed at the corners 71 or the periphery of the bottom of the door panel 7 will not fall out easily, so as to provide the effect of stopping the door panel 7 stably.
[0038] To release the limitation of the limiting frame plate 2 on the door panel 7 , a user simply steps on the edge of the limiting frame plate 2 to resume the limiting frame plate 2 and the first magnetic attraction plate 3 to their position of being flatly attached onto the floor, since the limiting slot 21 of the limiting frame plate 2 is framed around the corners 71 and the periphery of the bottom of the door panel or extended across the thickness of an outer side of the bottom of the door panel 7 , and the edge of the limiting slot 21 of the limiting frame plate 2 is slightly protruded from the door panel 7 . Therefore, the limitation of the door panel 7 can be released, and the door panel 7 can be rotated and opened freely to provide a very convenience use.
[0039] In addition, the fixed plate 1 is fixed to the floor and at a position along the moving path of the door panel 7 during construction, and the second magnetic attraction plate 6 is fixed to the bottom of the door panel 7 without damaging the wall or the door panel 7 , so as to provide a simple, convenient and quick construction. In addition, the first magnetic attraction plate 3 and the second magnetic attraction plate 6 are magnetically attracted to each other in a planar contact manner, and thus achieving the effects of increasing the magnetic attraction area significantly, and preventing the first magnetic attraction plate 3 and the second magnetic attraction plate 6 from falling out, so as to prevent the limiting frame plate 2 from falling out from the periphery of the corners 71 of the bottom of the door panel 7 . In the meantime, the limiting slot 21 of the limiting frame plate 2 is framed around the corners 71 of the bottom of the door panel 7 or the outer thickness of the bottom of the door panel 7 to stop the door panel 7 from moving, so as to achieve a stable limiting effect and improve the stopping effect of the door stopper.
[0040] According to the aforementioned embodiment, this disclosure further provides a door panel limiting method comprising the steps of: installing a planar door stopper to a floor and the planar door stopper being configured to be corresponsive to a moving path of a door panel 7 , and the planar door stopper including a first magnetic attraction plate 3 and a limiting frame plate 2 linked to the first magnetic attraction plate 3 , and an end of the limiting frame plate 2 being pivoted to the planar door stopper and swayable upward, and the other end of the limiting frame plate 2 having a limiting slot 21 with a width greater than the thickness of the door panel 7 ; and installing a second magnetic attraction plate 6 at the bottom of the door panel 7 and the second magnetic attraction plate 6 being configured to be corresponsive to the first magnetic attraction plate 3 , such that when the door panel 7 is opened, the attraction of the second magnetic attraction plate 6 exerted to the first magnetic attraction plate 3 drives the first magnetic attraction plate 3 and the limiting frame plate 2 to turn and move upward, and the limiting slot 21 of the limiting frame plate 2 is framed around the corners 71 and the periphery of the door panel 7 or extended cross an outer side of the bottom of the door panel 7 , so as to limit the door panel 7 at an opening position.
[0041] In the aforementioned method, this embodiment is the same as the previous one. In addition to the limiting frame plate 2 having the limiting slot 21 and the first magnetic attraction plate 3 , this embodiment further comprises a fixed plate 1 and a link plate 4 , and the linkage among the mutually pivoted fixed plate 1 , limiting frame plate 2 , first magnetic attraction plate 3 and link plate 4 forms a four-link-rod assembly. When the first magnetic attraction plate 3 is magnetically attracted by the second magnetic attraction plate 6 , the limiting frame plate 2 and the link plate 4 are driven to sway upward simultaneously, so that the first magnetic attraction plate 3 is still parallel to the floor and the bottom of the door panel 7 during the moving process, and the first magnetic attraction plate 3 is parallel to the bottom of the door panel 7 and upwardly attached onto a surface of the second magnetic attraction plate 6 , and the two magnetic attraction plates are magnetically attached with each other in a planar contact manner, so as to increasing the magnetic attraction area and preventing the first magnetic attraction plate 3 and the second magnetic attraction plate 6 from falling out. | Disclosed is a planar door stopper installed to a floor with respect to a moving path of a door panel, such that when the door panel is opened, the bottom of the door panel is attracted by the planar door stopper, and the planar door stopper is turned and moved upward and framed around the corners and the periphery of the door panel or extended cross an outer side of the bottom of the door panel, so as to limit the door panel at an opening position and overcome the drawbacks of a conventional door stopper which hinders walkway and causes inconvenient to construction. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a mat. More particularly, the present invention relates to a mat for a urinal.
2. Description of the Prior Arts
Numerous innovations for urinal mats have been provided in the prior art that will be described. Even though these innovations may be suitable for the specific individual purposes to which they address, however, they differ from the present invention.
A FIRST EXAMPLE, U.S. Pat. No. 5,313,672 to Luedtke et al. teaches a urinal mat provided with upstanding baffles to decelerate a stream of urine impinging thereon. The base of the mat is contoured and flexible to conform generally to the geometry within the urinal. Openings through the base are provided to permit liquids to drain through. Optionally provided are upstanding posts to receive a cake of deodorant thereon. An alternative embodiment provides a depression in the base into which deodorant may be deposited during manufacture. A flexible flange depends from an edge of the mat to engage the urinal sidewall in order to direct flush water over the mat.
A SECOND EXAMPLE, U.S. Pat. No. 5,604,937 to Davenport teaches a urinal screen assembly for disposition adjacent the drain of a urinal. The screen assembly includes feet or risers depending from the lower surface to maintain a spaced relation between at least the marginal edge of the assembly to allow liquid to flow therebetween and simultaneously prohibit the passage of unwanted solid materials. The main body portion of the screen assembly is provided with a plurality of tapered apertures which provide fluid communication therethrough and minimizes splash-back caused by an impinging stream of urine.
It is apparent that numerous innovations for urinal mats have been provided in the prior art that are adapted to be used. Furthermore, even though these innovations may be suitable for the specific individual purposes to which they address, however, they would not be suitable for the purposes of the present invention as heretofore described.
SUMMARY OF THE INVENTION
ACCORDINGLY, AN OBJECT of the present invention is to provide a mat for a urinal that avoids the disadvantages of the prior art.
ANOTHER OBJECT of the present invention is to provide a mat for a urinal that is simple and inexpensive to manufacture.
STILL ANOTHER OBJECT of the present invention is to provide a mat for a urinal that is simple to use.
BRIEFLY STATED, STILL YET ANOTHER OBJECT of the present invention is to provide a mat for. a urinal. The mat includes a base, baffles, hooks, and an optional container. The container receives either a urinal cake or an annunciator. The annunciator includes an activity switch, a signal conditioner, a counter conditioner, a sensor transducer that is exposed to the stream of urine, and an annunciator display that is visible and activates, either visibly and/or audibly, when the sensor transducer is impinged upon by the stream of urine.
The novel features which are considered characteristic of the present invention are set forth in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of the specific embodiments when read and understood in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
The figures of the drawing are briefly described as follows:
FIG. 1 is a diagrammatic perspective view of a first embodiment of the present invention in use;
FIG. 2 is an enlarged diagrammatic top plan view of the area generally enclosed by the dotted curve identified by arrow 2 in FIG. 1;
FIG. 3 is a diagrammatic cross sectional view taken along line 3 — 3 in FIG. 2;
FIG. 4 is an exploded diagrammatic perspective view of a second embodiment of the present invention;
FIG. 5 is an exploded diagrammatic perspective view of a third embodiment of the present invention;
FIG. 6 is a block diagram of the circuitry of the third embodiment of the present invention shown in FIG. 5 .
FIG. 7 is a diagrammatic perspective view of a forth embodiment of the present invention in use;
FIG. 8 is a diagrammatic elevational taken along in direction of arrow 8 in FIG. 7;
FIG. 9 is a diagrammatic cross sectional view taken along line 9 — 9 in FIG. 7; and
FIG. 10 is an electrical schematic of the forth embodiment of the present invention.
LIST OF REFERENCE NUMERALS UTILIZED IN THE DRAWING
First Embodiment
10 mat of present invention for urinal 12
12 urinal
14 drain of urinal 12
16 base for overlying drain 14 of urinal 12
17 throughbores in base 16 for permitting stream of urine to drain therethrough
18 baffles for decelerating stream of urine impinging thereon
20 hooks
22 central portion of base 16
24 periphery defining central portion 22 of base 16
Second Embodiment
26 container for selectively receiving item
28 lowermost periphery of container 26
30 tabs extending intermittently, and radially outwardly, from lowermost periphery 28 of container 26
32 uppermost periphery of container 26
34 posts of container 26
36 hooks terminating posts 34 of container 26
37 urinal cake
38 disk of container 26
40 perforations through disk 38 of container 26
42 amusing indicia on disk 38 of container 26
43 optional lens
Third Embodiment
44 annunciator
46 activity switch of annunciator 44
48 signal conditioner of annunciator 44
50 counter integrator of annunciator 44
52 sensor transducer of annunciator 44 for exposing to stream of urine
53 corresponding perforation
54 annunciator display of annunciator 44 for activating when sensor transducer 52 of annunciator 44 is impinged upon by stream of urine
56 group of perforations of perforations 40 through disk 38
58 LED (Light Emitting Device)
Fourth Embodiment
60 indicia
62 tabs
64 optional lenticular lens with cooperating indicia
66 side wall
68 upper surface of container 74
70 battery
72 separate discreet flasher component
74 container
76 electronic flasher components
78 housing of the at least one LED 58
80 optional switch device
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the figures, in which like numerals indicate like parts, and particularly to FIG. 1, a first embodiment of the mat of the present invention is shown generally at 10 for a urinal 12 having a drain 14 .
The configuration of the mat 10 can best be seen in FIGS. 2 and 3, and as such, will be discussed with reference thereto.
The mat 10 comprises a base 16 , baffles 18 , and hooks 20 . The base 16 is for overlying the drain 14 of the urinal 12 . The base 16 has throughbores 17 . The throughbores 17 are for permitting a stream of urine to drain therethrough. The baffles 18 upstand from the base 16 . The baffles 18 are for decelerating the stream of urine impinging thereon. The hooks 20 upstand from the base 16 . The hooks 20 selectively engage an item, that consist of the group comprising a disk 38 and a container 26 .
The base 16 is contoured and flexible for conforming generally to the urinal 12 .
The base 16 has a central portion 22 . The central portion 22 of the base 16 is defined by a periphery 24 . The periphery 24 of the central portion 22 of the base 16 is circular-shaped.
The hooks 20 are inverted L-shaped. The hooks 20 upstand intermittently from the periphery 24 of the central portion 22 of the base 16 .
The baffles 18 are slender, elongated, and pin-shaped. The baffles upstand from outboard of, and around, the hooks 20 .
The throughbores 17 through the base 16 are disposed both in, and outboard of, the central portion 22 of the base 16 .
A second embodiment of the mat 10 can be seen in FIG. 4, and as such, will be discussed with reference thereto.
The mat 10 further comprises a container 26 . The container 26 is selectively engaged in the hooks 20 . The container 26 is for selectively receiving an item.
The container 26 has a lowermost periphery 28 . The lowermost periphery 28 of the container 26 is continuous, ring-shaped, and has tabs 30 . The tabs 30 of the container 26 extend intermittently, and radially outwardly, from the lowermost periphery 28 of the container 26 . The tabs a 30 of the container 26 are selectively received by the hooks 20 , and when engaged thereby, the container 26 is maintained in the central portion 22 of the base 16 .
The container 26 further has an uppermost periphery 32 . The uppermost periphery 32 of the container 26 is continuous, ring-shaped, and spaced above the lowermost periphery 28 of the container 26 .
The container 26 further has posts 34 . The posts 34 of the container 26 are spaced-apart from each other so as to form spaces in the container 26 . The posts 34 of the container 26 extend upwardly from the lowermost periphery 28 thereof to the uppermost periphery 32 , where they terminate in hooks 36 . The hooks 36 of the posts 34 are inwardly radially facing.
The container 26 is for receiving a urinal cake 37 .
The hooks 36 of the posts 34 receive a disk 38 . The disk 38 may have optional perforations 40 therethrough and amusing indicia 42 thereon protected by an optional lens 43 .
A third embodiment of the mat 10 can best be understood from FIGS. 5 and 6, and as such, will be discussed with reference thereto.
The mat 10 further comprises an annunciator 44 . The annunciator 44 is received in the container 26 .
The annunciator 44 comprises an activity switch 46 , a signal conditioner 48 , and a counter integrator 50 .
The annunciator 44 further comprises a sensor transducer 52 . The sensor transducer 52 of the annunciator 44 is for exposing to the stream of urine.
The annunciator 44 further comprises an annunciator display 54 . The annunciator display 54 of the annunciator 44 is visible and is for activating when the sensor transducer 52 is impinged upon by the stream of urine.
The perforations 40 through the disk 38 are a group of perforations 56 . The group of perforations 56 through the disk 30 coincide with, so as to expose, the sensor transducer 52 , the annunciator display 54 , and the LEDS (Light Emitting Device) 58 .
The disk 38 may be covered by an optional protective lens 43 having a corresponding perforation 53 .
A fourth embodiment of the mat 10 can best be understood from FIGS. 7, 8 , 9 and 10 , and as such, will be discussed with reference thereto.
The mat 10 comprises further comprises a container 74 . The container 74 , having a side wall 66 , is selectively engaged in hooks 20 of base 16 for overlying drain 14 of urinal 12 , utilizing tabs 62 . The container houses a battery 70 and associated electronics. The associated electronics comprises at least one LED (Light Emitting Device) 58 . electronic flasher components 76 may be optionally contained in housing 78 of the at least one LED 58 or may be installed as a separate discreet flasher component 72 so as to cause the at least one LED 58 to flash.
An upper surface 68 of container 74 will have indicia 60 thereon and may be covered by an optional lenticular lens with cooperating indicia 64 . The at least one LED 58 , will be placed so as to be visible through the upper surface 68 and may or may not protrude through both the upper surface 68 and the optional lenticular lens with cooperating indicia 64 .
An optional switch device 80 is shown connected in a series loop with the battery 70 and the at least one LED 58 for activating and deactivating the this forth embodiment. It is to be noted that the light emitting device may be typically an incandescent lamp or a light emitting diode.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.
While the invention has been illustrated and described as embodied in a mat for a urinal, however, it is not limited to the details shown, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute characteristics of the generic or specific aspects of this invention. | A mat for a urinal. The mat includes a base, a disk with indicia thereon, baffles, hooks, and an optional container. The container receives either a urinal cake or an annunciator. The annunciator includes an activity switch, a signal conditioner, a counter conditioner, a sensor transducer that is exposed to the stream of urine, and an annunciator display that is visible and activates, either visibly and/or audibly, when the sensor transducer is impinged upon by the stream of urine. | 4 |
This application is a continuation of Ser. No. 626,681, filed July 2, 1984, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to exterior and interior building paints. The present invention more particularly relates to heat insulation of buildings by application of an insulating material to lower heating and cooling costs and enhance energy savings.
2. Brief Description of the Prior Art
Paint, in and of itself, has certain insulation characteristics when applied to the exterior or the interior of a building. However, it has not previously been known or suggested to incorporate insulation materials into paint to thereby produce an insulating paint. Hollow glass microspheres have been used in thermal insulating applications and as extenders in a variety of applications. The glass microspheres or extenders are suggested for application in epoxies, pastes, putties, adhesives, and sealants. Such extenders are particularly known and have been found useful to reduce weight while increasing the body or volume of plastic formed products.
Prior art patents are equally devoid of any reference to insulating paints for use in building heating and cooling applications. A paint insulation for an electrical conductor is shown in Japanese Patent No. 52-8486. The insulation is provided for use on an electrically conductive wire.
A fire resistant paint, manufactured by dispersing powdered glass and a powdered blowing agent through the paint, is shown in U.S. Pat. No. 3,630,764, to R. Shannon. At high temperatures, the dispersion agents are physically transformed into a layer of foamed glass which insulates the protected surface from the heat of the fire.
Hollow glass particles or microspheres are used to impart thermal insulation and fire resistance characteristics to a building panel in U.S. Pat. No. 4,235,836, to L. Wassel. The hollow glass particles are bonded with a refractory material by a binder.
U.S. Pat. No. 4,104,073, to W. Koide, et al., discloses the addition of glass microspheres or "microballoons" to putty in order to form a fire resistance seal. Microballoons are defined as fine, hollow particles of organic or inorganic material. The interior voids of the microballoons may be closed or open to the atmosphere.
Russian Pat. No. 717005 discloses a phosphate filler of spheroid shape for reducing the density of an insulating material. Hollow glass microspheres for sound insulation in a sheet-like material are shown in U.S. Pat. No. 4,079,162, to A. Metzger. U.S. Pat. No. 4,184,969, to B. Bhat, shows a fire resistant cellular fiber mixed with paint.
West German Pat. No. 1,921,559 shows a wallpaper paste that is adhered by heat and foams to effect sound and thermal insulation. An extrusion process for materials containing silica and alumina microspheres is shown in U.S. Pat. No. 4,273,806 to B.G. Sechler.
U.S. Pat. No. 3,968,060, to D. Vincent, shows micro capsules formed of a polymeric material. The capsules are of a small diameter of less than 5 microns and in one example, are incorporated in paint to give flame resistance and "hiding" power. Vincent shows a ratio of 0.1 to 1.0 pound of microcapsules per gallon of paint. The microcapsules are added to paint already formulated.
U.S. Pat. No. 4,286,013, to M. Daroga, et al., discloses a flame resistant barrier coating incorporating, by weight 20%-45% hollow glass microspheres. Daroga does state that the hollow glass microspheres are thermal insulators. Daroga would require a microsphere size of between 10 and 250 microns.
OBJECTS AND SUMMARY OF THE INVENTION
It is the principal object of the present invention to provide an insulating paint product having increased energy savings when the paint is applied to the exterior or interior of a building.
It is a related object of the present invention to provide an insulating paint of the foregoing character which is easily and cheaply manufactured from existing paint formulations and glass microspheres.
It is a further related object of the present invention to provide an improved method for the manufacture of insulating paint.
In accordance with the objects of the invention, a paint having insulation properties is formulated by the addition thereto of hollow glass extenders or microspheres. The paint formulation includes a known two-step mixing process. In the first or dispersion step, referred to as the grind stage or portion, surfactants or wetting agents, coalescing agents, defoamers, fillers, and the like, are added to a selected pigment and water. High speed rotational mixing of these various components results in a uniform dispersion of the components.
In a second stage or portion of the known mixing process, referred to as the letdown stage, additional materials are added including acrylic resins, additional water, buffers, defoamers and the like. The letdown stage is a simple mixing process, at a relatively lower speed of rotational mixing.
Paint formulations, including the well known additives and components referred to generally above, can vary widely. In the present invention, it is important to add hollow glass microspheres or extenders, of a particular diameter, to the formulation process. In order to obtain proper dispersion of the microspheres throughout the mixture, it is necessary that the microspheres be added as one of the last additives in the dispersion or grind stage of the process. It is also necessary that a particular weight portion or amount of microsphere material be added compared to the number of gallons of paint being manufactured in a given mix. This amount of microsphere material has been found to be between 0.5 and 0.75 but preferably about 0.75 pound of glass microspheres to one gallon of paint in the final formulation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A paint and a paint formulation process are hereinafter disclosed which incorporate an insulation material in the form of glass microspheres, such as commercially available hollow glass extenders, resulting in the production of what is hereinafter referred to as an insulating paint product. The insulating paint is manufactured to a preferred predetermined ratio of 0.75 pound of glass microspheres to one gallon of paint in the final formulation.
Formulation of the insulating paint generally follows principles well known in the art of formulating and mixing paint. A dispersion step or grind stage is performed first. In this step, predetermined amounts of water, surfactants, coalescing agents, defoamers, pigments, and fillers, along with such other standard material additives as are used in paint formulations, are mixed at high speed in an appropriate mixer or mill.
At the end of the grind stage, glass microspheres are added to the grind formulation in an amount of between about 0.5 pound to about 0.75 pound per gallon of paint formulated, preferably 0.75 pounds per gallon, and thoroughly mixed. It has been found that below 0.5 pound glass microspheres per gallon of paint does not give the superior insulation results desired. More than 0.75 pound of glass microspheres per gallon of paint results in a mixture that is so thick and viscous that it cannot be adequately mixed or worked.
It is important that the microspheres be added at the end of the grind stage or they will not adequately disperse in the mixture. Failure to adequately disperse the microspheres results in a gritty, grainy paint having poor surface characteristics.
As mentioned previously, the proportion of microspheres to a given paint formulation, is also important. Too large a quantity of the microspheres results in a paint formulation which is so dense that it cannot be properly or thoroughly mixed. Too small an amount of the microspheres results in a paint which does not exhibit good heat transfer resistance characteristics so important in insulation.
One glass microsphere product that has been found particularly well suited for use in the manufacture of the insulating paint is sold under the name Extendospheres XOL-200, manufactured by P.A. Industries, Chattanooga, Tenn. The physical properties of the glass microspheres are seen in the following table:
______________________________________GLASS MICROSPHERE PROPERTIESPROPERTY VALUE______________________________________Physical Form Free Flowing PowerColor WhiteBulk Density 7.5-9.0 lbs/ft.sup.3Effective Specific Gravity 0.22-0.28 gm/ccAverage Particle Size 100 micronsThermal Conductivity 0.35 BTU in/hr ft.sup.2 °F.Softening Point 1800° F.pH, Water Suspension 7.2Moisture Absorption, 24 Hrs, Wt % 0.4%Floaters, Minimum % by Volume 90%______________________________________
It is believed that particle size can vary between 50 and 150 microns, but that 100 microns is preferable. It is correspondingly believed that particle density can vary to between 0.20 and 0.30 gm/cc.
The base paint to which the glass microspheres are added includes surfactants to wet the pigments and enhance mixability. The pigments can include Titanium Dioxide, a white pigment. Ethylene glycol, for example, is an additive used to prevent the paint from drying too quickly. Coalescing agents or film forming materials put a film on the paint as it dries. Defoamers, as are known to those in the art, keep bubbles down during manufacture and use of the paint. The foregoing additives or ingredients are conventionally added during the grind stage of the mixing operation.
Various additives are added during the letdown stage of the mixing operation, occurring at relatively slower rotational mixing speeds. Thickening agents and acrylic resins, which allow the paint to adhere to the painted surface of a building interior or exterior are added. Buffers are used to maintain the pH at a set value. Turpentine and other petroleum products are used as aromatic solvents to mask the odor the paint would otherwise have.
The preceding two step formulation process, is well known in the industry. In any given case the exact order of material additives and amounts may vary. In any event, there is always a grind stage and a letdown stage.
The following Example illustrates the present invention.
EXAMPLE
Water, surface active agents and pigments are mixed in a suitable mixing tank and mixed at 1800 RPM for about 15 minutes. The microspheres described in the preceding Table, in a ratio of 0.75 pounds per gallon of paint, are then added and agitation is continued at about 1500 RPM until the microspheres are completely and uniformly dispersed. The foregoing comprises the grind stage. The remaining ingredients, principally the latex resin vehicle, are added and stirring is continued in the letdown stage at a reduced speed of about 1000 RPM until all the ingredients are thoroughly mixed. The final few ingredients are added. The latex base insulating paint thus produced is placed into appropriate containers for subsequent use.
The percent of glass microspheres to the total additives, excluding water, by weight, is on the order of 6.5 to 8.5 percent. These weight percentages equate to 0.5 to 0.75 pounds of microspheres per gallon of paint.
Though the invention has been described with a certain degree of particularity, the scope of the invention is more particularly defined in the appended claims. | An insulating paint for exteriors or interiors of buildings includes glass microspheres or hollow glass extenders, having a density of about 0.22 to 0.28 grams per cubic centimeter, and a diameter of about 100 microns. The microspheres are dispersed by high speed mixing in the grind stage of the paint formulation. The paint provides insulation against heat loss. | 2 |
FIELD OF THE INVENTION
The invention relates to microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS) device fabrication, including embodiments to processes producing a single-crystalline device fabricated on a single-sided or double-sided polished wafer employing processing from only one side and having a significant separation between the device and substrate.
BACKGROUND OF THE INVENTION
MEMS and NEMS technology continues to find new applications and employ multiple fabrication techniques. One known fabrication approach uses a high-temperature low pressure chemical vapor deposition (LPCVD) process to deposit polycrystalline silicon on top of a wafer with complementary metal-oxide-semiconductor (CMOS) circuitry. The polycrystalline silicon is then patterned to form a resonator.
In another known approach, a resonator is made through bulk micromachining on a silicon-on-insulator (SOI) wafer. The insulating layer acts as an etch stop for the deep reactive ion etch (DRIE) which defines the resonator shape in two dimensions (the plane of the wafer). The trenches are then refilled with silicon dioxide, and an epitaxial layer of silicon is grown over the device. This layer allows for circuitry to be later fabricated above the MEMS device. Next, holes are etched into the epitaxial layer to allow a vapor, such as a hydrofluoric (HF) acid etch in to selectively etch the silicon dioxide and release the resonator. Finally, the holes are filled using a vacuum deposition process resulting in a vacuum-sealed MEMS resonator.
Another known process is directed at producing a surface micromachined resonator similar to that above. However, this process uses polycrystalline SiGe instead of polycrystalline silicon. There are two methods: 1. Deposit the SiGe as a polycrystalline material which requires a lower temperature than that of polycrystalline silicon or 2. Deposit the SiGe at an even lower temperature which results in amorphous SiGe, and then use a laser to rapidly heat the surface which results in polycrystalline SiGe and does not affect any underlying circuitry.
Yet another process is similar to the previous except that a dome shape is achieved by depositing polycrystalline silicon over a sacrificial oxide at a temperature where the polycrystalline silicon is compressively stressed.
Existing methods include three release techniques: basic, backside, and surface micromachining.
For the basic release technique, the device is shaped on the front side of an SOI wafer. HF is then used to release the device by etching the insulator layer. Disadvantages include that the device's proximity to the substrate is defined by the insulator layer. This subjects the device to a higher risk of stiction during processing and operation.
For the backside release technique, SOI wafers have the device created on the front side. After all processing is completed, etch holes are patterned on the backside and the wafer is etched from the backside. The insulator layer behaves as an etch-stop. The insulator is then etched separately in an etch which is selective to just the insulator, which releases the structure. Disadvantages include a backside alignment which requires double-side polished wafers that is less accurate (front-to-back alignment) and which requires a larger dead-space around the device. This also requires a long backside etch and results in a weaker wafer.
For the surface micromachining technique, the devices are made above the plane of the wafer using processes such as chemical vapor deposition (CVD) to deposit the device material on top of a sacrificial material. The material is then patterned and the device is released using an etch which is selective to only the sacrificial material. The material used for this is not single-crystal, resulting in poorer behaviors including lower Q when used for a resonant device.
What is needed, therefore, are techniques for single-sided fabrication with enhanced compatibility of MEMS technology with standard CMOS technology and a process by which single-crystal MEMS/NEMS devices can be created alongside circuitry without the need for processing from the backside of the wafer.
SUMMARY OF THE INVENTION
One embodiment of the present invention provides a process by which single-crystal MEMS/NEMS devices can be created alongside circuitry without the need for processing from the backside of the wafer. References to MEMS fabrication methods and MEMS devices include NEMS fabrication and NEMS devices unless specifically mentioned otherwise. This may be referred to as micro/nanoelectromechanical systems (MNEMS). An embodiment produces a single-crystalline device fabricated on a single-sided polished wafer. It employs processing from only the front-side, resulting in a significant separation between the device and substrate that is realized by an isotropic etch.
Embodiments of the process can form devices employing an SOI (or similar) wafer or by implanting a buried layer with etch characteristics different from the substrate (e.g. an oxide layer). If other than an SOI wafer is used, a material with etch characteristics different from the substrate or a material that will react with the substrate to form a material with etch characteristics different from the substrate is ion implanted into the substrate to form the underside of the device.
Generally, when SOI or implanting is mentioned, any wafer including various materials may be used provided the middle material is not etched by the first or third etch.
Embodiments support single crystal (high-Q) structures, hermetic wafer-level packaging, CMOS-compatibility, and minimal deviations from or additions to existing CMOS processes.
One embodiment includes a method for producing a micro/nanoelectromechanical system (MNEMS) device that comprises providing a multilayer wafer that comprises an upper layer, a middle layer, and a substrate; forming a device in the upper layer material, where gaps are defined in the upper layer material; filling the gaps with at least one protective gap material where the at least one protective gap material has etch characteristics that are different from the etch characteristics of the device's upper layer material and different from the substrate. It further includes removing at least a top portion of the at least one protective gap material from the upper layer; etching the at least one protective gap material, wherein a portion of the at least one protective gap material remains on the sidewalls of the surrounding upper layer; etching the substrate beneath the device, excluding the middle layer, thereby releasing the device from the substrate; and etching the middle layer wherein the etch of the step of etching the middle layer is selective to the middle layer and the at least one protective gap material.
In other embodiments, forming a device in the upper layer comprises a deep reactive ion etch (DRIE), and the step of removing at least a top portion of the at least one protective gap material comprises chemical-mechanical polishing (CMP).
Another embodiment further comprises a step of at least partially forming circuitry, performed after the step of removing at least a top portion of the at least one protective gap material. In one embodiment, the step of etching the at least one protective gap material comprises deep reactive ion etching (DRIE). In another embodiment, the step of etching the at least one protective gap material comprises a xenon difluoride (XeF 2 ) etch.
For other embodiments, the at least one protective gap material is one protective gap material and the step of etching the at least one protective gap material comprises a directional, anisotropic etch. For yet another embodiment, the directional, anisotropic etch comprises a deep reactive ion etch (DRIE). For additional embodiments, the etch of the step of etching the substrate beneath the device is selected from the group consisting of: an isotropic etch, a first anisotropic etch followed by an isotropic etch, and a cycling of anisotropic/isotropic etches. For still other embodiments, the steps are performed in any order providing that high temperature processes of forming the device are performed before forming circuitry.
One embodiment includes a method for producing a micro/nanoelectromechanical system (MNEMS) device comprising: providing a multilayer wafer comprising an upper layer, a middle layer, and a substrate; forming a device in the upper layer by defining gaps wherein a protecting layer is deposited on the upper layer, and where the protecting layer gap material has etch characteristics that are different from the etch characteristics of the upper layer and the substrate; etching through the middle layer; etching the substrate beneath the device, excluding the middle layer, thereby releasing the device from the substrate; and etching the middle layer wherein the etch of the step of etching the middle layer is selective to the middle layer and the protecting layer. In embodiments, the wafer comprises circuitry.
In other embodiments, the step of forming a device comprises deep reactive ion etching (DRIE) and the step of forming a device also comprises etchants selected from the group consisting of: sulfur hexafluoride (SF 6 ), oxygen (O 2 ), and silicon tetrafluoride (SiF 4 ).
For further embodiments, the step of etching the substrate comprises removing substrate beneath device while reforming a protecting layer. For still other embodiments, the steps are performed in any order providing that high temperature processes of forming the device are performed before forming circuitry.
One embodiment includes an implant method for producing a micro/nanoelectromechanical system (MNEMS) device comprising: providing a substrate; implanting a middle layer; etching to the implanted middle layer, thereby delineating a device; etching through the implanted middle layer, thereby removing the substrate beneath the device; and removing the implanted middle layer beneath the device. In other embodiments, the substrate comprises circuitry. In yet other embodiments, the etching to the implanted middle layer step comprises a deep reactive ion etch (DRIE). For other embodiments, these steps may be performed in any order, providing that high temperature processes of forming the device are performed before forming circuitry.
The features and advantages described herein are not all-inclusive and, in particular, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the drawings, specification, and claims. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and not to limit the scope of the inventive subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective diagram illustrating a device configured in accordance with one embodiment of the present invention.
FIGS. 2A-2H are sectional elevation views illustrating a plurality of processing steps for fabricating a multilayer or a silicon-on-insulator MEMS device configured in accordance with one embodiment of the present invention.
FIGS. 3A-3E are sectional elevation views illustrating a sequence of processing steps for an implant fabricating process for a MEMS device configured in accordance with one embodiment of the present invention.
FIG. 4 is a flow chart depicting a multilayer or a silicon-on-insulator fabrication process where circuitry is provided after etching and insulating the upper layer in accordance with one embodiment of the present invention.
FIG. 5 is a flow chart depicting an implant fabrication process in accordance with one embodiment of the present invention.
FIG. 6 is a flow chart depicting a multilayer or a silicon-on-insulator fabrication process where circuitry is provided before MEMS device etching steps in accordance with one embodiment of the present invention.
FIG. 7 is a flow chart depicting a multilayer or a silicon-on-insulator fabrication process using an etch with simultaneous deposition of a protective layer in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION
In one embodiment, begin with (1) a CMOS wafer with circuitry already fabricated. (2) Etch trenches to define MEMS structure using an anisotropic etch. During the etch, a protective layer is deposited simultaneously and remains only on the sidewalls of the etched cavity. In one embodiment, the etch could use sulfur hexafluoride (SF 6 ) to etch the silicon and oxygen (O 2 ) to form the protective layer on the sidewalls. In another embodiment, the protective layer is formed from a combination of O 2 , SiF 4 , and SF 6 . In another embodiment, the protective layer is SiO 2 formed from an O 2 plasma (plasma-enhanced oxidation). (3) The etch is either timed or stops on a middle layer (e.g. SOI) whose etch characteristics are different from that of the materials above and below. The middle layer can be formed, for example, by either pre-CMOS (e.g. bonded SOI, Separation by Implantation of Oxygen (SIMOX), etc.) or post-CMOS (SIMOX, ion implantation). (4) The middle layer is removed from the bottom of the trenches via an etch (e.g. reactive ion etch (RIE)/DRIE, wet etch, etc.) to expose the substrate material. (5) The substrate is then etched isotropically, first anisotropically and then isotropically, or by cycling between anisotropic and isotropic etches. The protective layer may be removed during the etch of the middle layer. As a result, the etch to remove the substrate may first require the reformation of a protective layer, and its removal at the bottom of the trench (e.g. via an anisotropic etch). (6) The middle layer is etched (e.g. using a vapor HF etch).
In another embodiment, begin with: (1) a wafer with circuitry fabricated. (2) Etch trenches to define a MEMS structure using an anisotropic etch. The etch is either timed or stops after etching to the middle layer. The middle layer can either be preexisting (e.g. SOI) or formed after CMOS (ion-implantation). (3) A thin protective layer is formed on the sidewalls. This could be done before or after step 4. If after step 4, this requires an etch that will remove this layer from the bottom of the trenches. (4) The middle layer is etched at the bottom of the trenches. (5) The substrate material is then etched isotropically, anisotropically first and then isotropically, or by cycling between anisotropic and isotropic etches. (6) The middle layer is etched (e.g. such as vapor HF etch).
In another embodiment, (1) etch trenches into wafer. The etch is either timed or stops on a middle layer. The middle layer can be preexisting (e.g. SOI) or formed after CMOS (e.g. ion-implantation). (2) the middle layer is etched to expose the substrate (3) the trenches are refilled (e.g. CVD, vapor deposition (VD), or deposition) and then etched-back using anisotropic etch, chemical-mechanical polishing or planarization (CMP), or similar) with either a protective material whose etch characteristics are different from the wafer material above and below the middle layer, or first a thin conformal protective layer (e.g. silicon dioxide) with the bottom removed via an anisotropic etch, followed by the deposition of a second material with different etch characteristics from the protective layer (e.g. polycrystalline silicon), but whose characteristics may be similar to the materials above and below the middle layer. (4) CMOS circuitry is created. (5) Trenches that were refilled are etched such that protective layer remains on the sidewalls, the etch continues until the substrate material is exposed. (6) The substrate material is then etched isotropically, first anisotropically and then isotropically, or by cycling between anisotropic and isotropic etches. (7) The protective layer and middle layer are etched (e.g. such as vapor HF etch).
FIG. 1 is a perspective diagram illustrating a structure 100 including substrate 110 with circuitry 125 and device 135 configured in accordance with one embodiment of the present invention.
FIGS. 2A through 2H constitute a sequence of schematic drawings showing a plurality of certain steps in the process of manufacturing a silicon-on-insulator device including an intermediate step of fabricating circuitry in accordance with one embodiment of the present invention.
FIG. 2A is a sectional elevation view 200 of a multilayer or a silicon-on-insulator (SOI) wafer substrate depicting a middle insulator layer 205 between silicon layers 210 and 215 . This corresponds to step 1405 of the flow chart in FIG. 4 .
In FIG. 2B , trenches 320 may be formed in silicon layer 315 using processes such as photolithography and etching technology such as reactive ion etch (RIE) to include deep reactive ion etch, well known to those skilled in the art. Middle insulator layer 305 is etched while silicon layer 310 of structure 300 may or may not be etched. This corresponds to step 1410 of the flow chart in FIG. 4 .
FIG. 2C depicts formation of first protective material 430 , whose etch characteristics differ from that of the material forming the device, and second gap filling material layer 425 on the top surface of silicon layer 415 , filling trench areas 420 . Any material 430 that is not etched by the etch used for the gap filling material 425 or the substrate 410 may be employed. Material layers 430 and 425 may fill or cover the sidewalls. Sidewall covering is employed when the MEMS device is fabricated after CMOS fabrication. Filling may be used if the MEMS device is fabricated before or after CMOS. As an example, the oxide of material layer 415 may be grown or deposited. In another embodiment, instead of the oxide material layer insulator, an etch of silicon layer 415 may result in insulated sidewalls as a byproduct of the etch. Any etch may be employed where a protective material is deposited during the etch (e.g. a cryo-etch). Middle layer 405 and silicon layer 410 of structure 400 remain. This corresponds to step 1415 of the flow chart in FIG. 4 .
In FIG. 2D , a top portion of materials 430 and 425 of FIG. 2C may be removed from top layer of silicon 515 , leaving first and second, materials in trenches 520 . Removal may be by processes such as chemical-mechanical polishing or planarization. (CMP) of structure 500 . In one embodiment, removal may be by an anisotropic etch such as RIE, or an isotropic etch such as HF. The timing of the etch should be controlled to ensure that the trench fill-material is not removed. Layers 505 and 510 remain. This corresponds to step 1420 of the flow chart in FIG. 4 .
The sectional elevation view of structure 600 of FIG. 2E depicts optional formation of circuitry 625 in layer 615 in a conventional manner. Circuitry may be placed at various locations on the wafer or die. The circuitry formation or partial formation step is preferably performed when there will be no subsequent processing steps that may jeopardize the integrity of circuitry 625 . This may include high temperature processes. Trenches 620 and layers 605 and 610 remain. This corresponds to step 1425 of the flow chart in FIG. 4 .
FIG. 2F depicts an etch of the gap filling material in trenches 620 of FIG. 2E (also shown as gap filling material 425 from FIG. 2C ) such that material 730 remains on the sides of trenches 720 of layer 715 . A directional, anisotropic etch such as DRIE may be employed if the second gap filling material is not used. Otherwise, if a second gap filling material is used, the etch can be either isotropic or anisotropic. The etch extends through layer 705 into layer 710 of structure 700 . This corresponds to step 1430 of the flow chart in FIG. 4 . This etch could include a xenon difluoride (XeF 2 ) etch.
In FIG. 2G , an isotropic or combination anisotropic/isotropic etch is used to remove the material of substrate layer 810 beneath the device, but not remove middle insulating layer 805 beneath the device, thereby releasing the device from the substrate 810 . Protective material remains on the sides of trenches 830 of layer 815 of structure 800 . This corresponds to step 1435 of the flow chart in FIG. 4 .
FIG. 2H shows middle material 905 beneath trench-delineated device 935 removed in an etch which is selective to just the middle insulator and gap-filling material. Protective material on the sides of trenches 930 of layer 915 of structure 900 is removed as well as middle material 905 . This corresponds to step 1440 of the flow chart in FIG. 4 .
FIGS. 3A through 3E represent a sequence of schematic drawings showing a plurality of certain steps in the process of manufacturing an implant process device in accordance with another embodiment of the present invention.
FIG. 3A is an implant process initial step illustrating structure 1000 including optional formation of circuitry 1025 on surface 1015 of substrate 1010 in a conventional manner. Circuitry may be placed at various locations on the wafer or die. The circuitry formation or partial formation step is preferably performed when there will be no subsequent processing steps that may jeopardize the integrity of circuitry. This corresponds to step 1505 of the flow chart of FIG. 5 .
FIG. 3B shows implanted insulator 1140 in structure 1100 including circuitry 1125 on surface 1115 of substrate 1110 . The implanted insulating material 1140 , or a material that will react with the substrate to form an insulating material, is ion implanted into the substrate to form the underside of the device. This corresponds to step 1510 of the flow chart of FIG. 5 .
FIG. 3C depicts an etching of structure 1200 where trenches 1220 are formed from surface 1215 in substrate 1210 to or through implanted insulator layer 1140 . This is an anisotropic etch for which the implanted insulating layer may act as an etch-stop and may be either a dry etch (DRIE or RIE) or a wet etch. Also depicted is protective layer 1230 formed on the side walls of trenches 1220 , formed by etching. Structure 1200 may include circuitry 1225 on surface 1215 of substrate 1210 . This corresponds to step 1515 of the flow chart of FIG. 5 .
In FIG. 3D , substrate 1310 beneath device 1335 is removed. This may include etching through the implanted layer 1140 under trenches 1320 and removal of the substrate beneath the device with an isotropic etch (or anisotropic/isotropic combination) followed by removal of the implanted material 1140 . This releases trench-delineated device 1335 from substrate 1310 . This corresponds to step 1520 of the flow chart of FIG. 5 .
In FIG. 3E , implanted insulating layer 1140 beneath device 1335 and protective layer 1230 of FIG. 3C are removed, if not removed in the step of FIG. 3D . This corresponds to step 1525 of the flow chart of FIG. 5 .
FIG. 4 is a flow chart depicting an embodiment of a multilayer or a silicon on insulator fabrication process 1400 including the steps of: providing a multilayer or a silicon on insulator (SOI) substrate 1405 ; etching a silicon layer (and perhaps middle layer) to form trenches 1410 ; depositing one protective layer or a first protective and then a second gap filling material on an upper layer 1415 ; removing the protective layer or protective layer and gap filling material by, for example, CMP 1420 ; optionally fabricating circuitry 1425 ; etching through the one protective layer or first and second material layers 1430 ; removing silicon beneath the trench-delineated device 1435 ; and removing the middle layer beneath the device 1440 .
FIG. 5 is a flow chart depicting an embodiment of an implant process 1500 including the steps of: providing a substrate optionally configured with circuitry 1505 ; implanting a middle layer 1510 ; etching to or through the implanted layer 1515 ; wherein trench side walls are protected, removing substrate beneath device for step 1520 ; and removing implanted insulator layer 1525 .
FIG. 6 is a flow chart depicting an embodiment of a fabrication process 1600 including the steps of providing a multilayer or an SOI wafer with CMOS devices 1605 ; etching to or through the middle layer 1610 to form trenches; protecting the trenches formed in the upper layer 1615 (to passivate/insulate the sidewalls); removing the protective layer at the bottom of the trenches through a directional etch 1620 ; removing the substrate beneath the device through an isotropic etch 1625 ; and then the middle materials are removed 1630 .
FIG. 7 is a flow chart depicting an embodiment of a multilayer or a silicon on insulator fabrication process 1700 using a cryo-etch. This simultaneously deposits the protective layer during the etch of the upper layer using SF 6 and passivates/insulates the sidewalls using condensation of oxides. It includes the steps of: providing a substrate optionally configured with circuitry 1705 ; cryo-etching to the middle layer 1710 , wherein trench side walls are protected with a protective layer; etching through middle layer 1715 ; removing substrate beneath device while reforming the protective layer, if needed 1720 ; and removing middle layer 1725 .
Embodiments may include the following steps for fabricating a CMOS-compatible silicon device: 1) deposit a field oxide; 2) etch the oxide/active area; 3) etch silicon to form resonator or other device; 4) grow gate oxide; 5) deposit polysilicon #1; 6) etch polysilicon; 7) source/drain doping; 8) include intra-poly dielectrics; 9) deposit polysilicon #2; 10) include poly-metal dielectrics; 11) deposit metal layer #1; 12) deposit intra-metal dielectrics; 13) deposit metal layer #2; 14) passivation; 15) etch openings (e.g. DRIE); 16) isotropic silicon etch (Release step #1); 17) HF vapor-phase etch (Release step #2); 18) deposit glass frit; and 19) melt glass frit under vacuum.
Note that the steps may be performed in alternate orders providing that high temperature processes are preferably performed before forming the circuitry.
Summarizing, embodiments include using CVD, vapor deposition (VD), or thermal oxidation to produce sidewall protection. Methods use the condensation of material on the sidewalls to form the protection layer, this is performed during the etches, and not in a separate step. Some etches do not include SF 6 and O 2 as etch gases. In addition, the buried oxide layer of embodiments presented is etched before the protection layer is deposited. Also, one procedure of embodiments is to create devices by refilling the trenches, and then etching out the interior of the trench. Furthermore, a middle layer can be formed in only certain parts of the wafer by ion implantation.
The foregoing description of the embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of this disclosure. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto. | A process producing a single-crystalline device fabricated on a single-sided polished wafer employing processing from only the front-side and having a significant separation between the device and substrate is provided. In one embodiment, a method comprises an upper layer and a lower substrate. A device is formed in the upper layer, defined by gaps. The gaps are filled with at least one material that has etch characteristics different from those of the device and the substrate. At least a top portion of the gap material is removed from the upper layer. The gap material is etched so that a portion of the gap-material remains on the sidewalls of the surrounding upper layer. The material beneath the device is then etched, excluding an insulating layer beneath the device, releasing the device from the substrate. The insulating material beneath the device is then etched, the etch being selective to the insulating material and the gap material. | 7 |
FIELD OF THE INVENTION
This invention relates to the concept of functionally hyperactive red/far-red light sensor genes such as a modified phytochrome A (PHYA) nucleic acid molecule of which a serine/threonine amino acid at the hinge region between the amino- and the carboxy-domains and at the N-terminal serine/threonine cluster of phytochrome for Pr/Pfr-dependent phosphorylation/dephosphorylation was substituted with alanine. The phytochrome A functions as the photoreceptor in far-red wavelength light in mediating the suppression of shade avoidance and the greening of leaves. These modified phytochromes lacking critical serine/threonine residues for phosphorylation are hyperactive under far-red light. Another group of the modified phytochromes with bathochromic shift in their Pr-absorption band greatly is to provide an enhanced far-red sensitivity of plants growing under canopy and shade conditions. The present invention also provides the methods and processes for generating transgenic higher plants transformed with the said nucleic acid molecule to engineer internode elongation of economically important crop plants.
BACKGROUND OF THE INVENTION
Phytochrome is a photoreceptor that control diverse aspects of growth and development in higher plants. Upon irradiation, the photoreceptor undergoes reversible interconversion between biologically inactive, red-absorbing phytochrome (Pr) and biologically active, far-red light absorbing phytochrome (Pfr) that enables it act as a molecular light switch. Photoconversion into Pfr form by red light treatment triggers its nuclear translocation from cytosol, initiating signaling that alters gene expression and thereby growth and development of plants. There are two photoisomers, red light (λmax=660 nm) absorbing form (designated to Pr) and far-red light (λmax=730 nm) absorbing form (designated to Pfr). Particularly, the absorption spectra of phytochrome are near the spectrum of canopy ( FIG. 1 , Neff et al, 2000). This spectral property shows it is directly related to shade avoidance. The initiation of shade avoidance depends on low R (red): FR (far red light) ratio. Low R: FR ratio accelerates not only the shade avoidance reaction that involves hypocotyls elongation, but also early flowering that causes immature fruit developments (Smith & Whitelam, 1997).
The photoreceptor consists of a 116-127 kDa apoprotein and a covalently attached linear tetrapyrrole chromophore. In plants, the apoproteins are encodes by a small gene family, e.g., five members PHYA-E in Arabidopsis . Molecular genetic analysis revealed that individual members of phytochromes play overlapping but distinct physiological roles. PHYA, a type 1 photo-labile phytochrome, controls very low fluence response and FR-high irradiance response, while type 2 phytochrome, encoded by PHYB-E, abundant in light-grown tissues, regulates low fluence responses (Quail et al., 1995; Neff et al., 2000).
Previously, oat PhyA was shown to undergo post-translational modification after red-light treatment, including phosphorylation at serine 598 th residue (Lapko et al., 1999). The Pfr-specific phosphorylation at serine 598 th residue suggested a regulatory role of this residue on photo-sensory signalling. To test the possibility, in the present invention, we performed site-directed mutagenesis with oat PHYA, substituting serine 598 th to alanine (designated S598A PHYA in the invention). The biological activity of mutated PHYA was compared with wild type PHYA by overexpression into phyA-null mutant of Arabidopsis . Under FR light condition, both wild type PHYA and S598A PHYA could complement phyA-deficient mutant, showing FR-high irradiance response. However, at adult stage, transgenic Arabidopsis plants overexpressing S598A PHYA exhibited shortened internode in adult plants and shortened petiole, whereas transgenic plants overexpressing wild type PHYA did not show any noticeable defect in adult morphology. Overexpression of PP2A gene resulted in a suppressed internode phenotype similar to that of S598A mutant phytochrome. Thus, we include in the invention the overexpression of PP2A gene as being equivalent to bona fide hyperactive phytochrome by keeping it dephosphorylated in vivo. These results indicate that S598A PHYA is more biologically active than wild type PHYA at least in the regulation of internode elongation.
Serine-to-alanine substitutions at the N-terminal serine/threonine cluster in phytochromes result in hyperactive phytochromes in Arabidopsis thaliana (Stockhaus et al., 1992). Among the N-terminal serine residues, serine-7 is the only residue in the cluster that is specifically autophosphorylated or phosphorylated by a phytochrome kinase in vivo (Lapko et al., 1997). Thus, S7A mutant phytochrome is a hyperactive phytochrome.
It has been possible to locate the active site of the autophosphorylating phytochrome A (acting as a “phytochrome kinase”). The PAS-related domain in the C-terminal half of the protein contains active site residues. Mutation or deletion of these residues is expected to result in hyperactivity of phytochrome A in vivo, since such mutants cannot autophosphorylate the protein.
By using the method of site-directed mutagenesis (Bhoo et al., 1997) and DNA shuffling, we have also generated phytochrome A mutants that absorb far-red shade light more effectively than wild type. This was achieved by substituting critical amino acid residues (for example, isoleucine-80) within the chromophore binding crevice of phytochrome A. FIG. 1 illustrates how a few nanometer red shift of the Pr-absorption band, so that it can absorb canopy and shade lights several orders of magnitude more effectively in the far-red wavelength than with the overexpression of wild type phytochrome. We propose that the far-red spectral action spectrum for the induction of seed germination (Shinomura et al., 1996) is consistent with the Pr-absorption spectrum of “hot band” or “twisted” chromophore conformation origin, the bathochromic mutant phytochromes are hyperactive in the responses of higher plants to far-red light.
This invention can be practically applied to control growth and development in general and internode elongation and leaf greening of higher plants in particular (Smith and Whitelam, 1997). The higher plants referred to here are those economically important in agriculture and horticulture. As used herein, the term “economically important higher plants” refers to higher plants that are capable of photosynthesis and widely cultivated for commercial purpose. The term “plant cell” includes any cells derived from a higher plant, including differentiated as well as undifferentiated tissues, such as callus and plant seeds.
SUMMARY OF THE INVENTION
The present invention relates to nucleic acid molecules encoding modified phytochrome A (PHYA) protein of which 598 th serine amino acid for Pfr-dependent phosphorylation was substituted by alanine. Such nucleic acid molecules preferentially encode a protein with the amino acid sequence as given in SEQ ID NO: 2. The mutant phytochrome A displays hypersensitive biological activity in the response of higher plants to far-red wavelength light.
The present invention extends to other mutant phytochromes that exhibit similar hyperactivity in the far-red spectral region and under canopy/shade light conditions. Such mutant phytochromes include 7 th serine-to-alanine mutants, PAS-related domain substitution/deletion mutants, and also the spectral mutants that absorb far-red light effectively.
Also, provided includes an uninterrupted gene sequence encoding the S598A PHYA, a nucleic acid fragment that can be directly ligated into recombinant DNA constructs, and the S598A PHYA expression vectors that can be readily used to transform cells of higher plants according to the present invention.
Provided also are transgenic higher plants that are readily accessible to the Agrobacterium -mediated transformation. Overexpression of the S598A PHYA gene results in shortened internodes. These phenotypic traits can be exploited in a way that higher plants of interest harboring the S598A PHYA gene exhibit dwarfism, a very important commercial trait in horticulture and agriculture.
Therefore, the present invention provides: 1. Nucleic acid molecules encoding a polypeptide of a modified oat phytochrome A (PHYA) of which 598 th serine amino acid for Pfr-dependent phosphorylation was substituted by alanine, comprising a nucleotide sequence as given in SEQ ID NO: 1.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows the illustration of the bathochromic shift of the Pr-absorption spectrum. Note that the Pr form of phytochrome now strongly absorbs far-red light of wavelength longer than 700 nm.
FIG. 2 A and FIG. 2B show site-directed mutagenesis of oat phytochrome A. The 598 th serine residue, a target of Pfr-dependent phosphorylation was changed to alanine. After mutagenesis, XbaI digestion was performed to get a correct mutant gene (A). mt1 and mt2 are two different clones after mutagenesis, and wt is oat wild-type phyA gene in the vector. S is Promega 1 kb DNA ladder (G571 1). Some DNA sizes of 1 kb DNA ladder are indicated. A XbaI site at 1798bp was created during the mutagenesis. So, there are 3 fragments in the WT, 2820bp, 525bp and 3330bp, whereas there are 4 fragments in the MT, 1760bp, 951bp, 525bp and 3330bp. At the bottom of the FIG. 2A , 525bp band was shown. From the results, m1 clone showed the right restriction pattern and was further confirmation by DNA sequencing. B. DNA sequencing gel showing the changes of bases. WT sequence 5′-AGTT-3′ was changed to 5′GCTC-3′, which changed the Serine at 598 to Alanine.
FIG. 3 A and FIG. 3B show transgene expression of wildtype PHYA and S598A PHYA. FIG. 3 A. RT-PCR. The arrow showed the amplified bands of C-terminus DNA fragment of oat phyA (581bp). FIG. 3 B. Western blot analysis. 50 ug of each protein sample was used for this analysis. The arrow showed the protein band of phyA. Lane WT, protein sample from wild-type Arabidopsis thaliana (positive control); lane A, protein sample from wild-type Arabidopsis thaliana phyA-201 mutant (negative control); the number represents independent transgenic seed lines of WT and MT; lane S, DNA standard (Gibco 1 kb ladder, 15615-016).
FIG. 4 shows FR-high irradiance response of transgenic seedlings. The seedlings were grown on MS media for 4 days in darkness or under FR light. The scale bar indicates 5 mm.
FIG. 5 A and FIG. 5B show adult morphology of transgenic plants. FIG. 5 A. The morphology of representative plants grown under longa-day condition for 5 weeks. FIG. 5 B. The average heights of plants grown under long day condition for 6 weeks. Each measurement was done with at least 12 plants.
DETAILED DESCRIPTION OF THE INVENTION
Phytochromes are the best characterized photoreceptor that regulate diverse aspects of growth and development in higher plants. Upon irradiation, it exhibits interconvertible photo-conversion between biologically inactive Pr (red absorbing phytochrome) form and biologically active Pfr (far-red absorbing phytochrome) form that enables it to act as a molecular light switch (Butler et al., 1959). The activated Pfr triggers downstream signaling that result in diverse photo-responses. Upon Pfr formation after red light absorption, phytochrome undergoes several conformational changes. The Pfr-chromophore is more exposed than the Pr-chromophore (Park et al., 2000). The N-terminal domain is more exposed in the Pr form than in the Pfr form. The hinge region is preferentially exposed in the Pfr form. These conformational changes would trigger downstream signaling events. Phosphorylation is a primary mechanism that transduces signaling in eukaryotes. Phytochrome signaling involves several phosphorylation events. Phytochrome itself exhibited Ser/Thr kinase activity (Yeh and Lagarias, 1997). PKS1, one of the phytochrome interacting factors including PIF3 and NDPK2 have been phosphorylated by phytochrome (Fankhauser, et al., 1999). Interestingly phytochrome is also phosphorylated in a Pfr-dependent manner. The 598 th Serine residue is preferentially phosphorylated in the Pfr form in vivo (Lapko et al., 1999). In vitro kinase assay showed that the 598 th serine was shown to be important for the light-regulation of autophosphorylation/phosphotransfer activity of phytochrome. As an effort to characterize the biological role of phosphorylation at 598 th serine of phytochrome in vivo, we performed site-directed mutagenesis and generated mutant PHYA of which 598 th serine was substituted by alanine. After generation of transgenic plants that overexpress wildtype PHYA or mutant PHYA using phyA-null Arabidopsis mutant, the phenotypes of transgenic plants were examined.
Using immunoblot analysis, we identified transgenic lines that overexpress foreign gene, PHYA or mutant PHYA (FIG. 3 A and FIG. 3 B). Two lines of wildtype PHYA overexpressing lines, designated as WT #4 and WT #6, and several lines of S598A PHYA overexpressing lines were chosen for further analysis.
To test whether introduced PHYA is biologically functional in Arabidopsis , we grew seedlings under FR light or in the dark. As shown in FIG. 4 , Ler wild type showed typical FR-responses, including shortened hypocotyl, expanded cotyledons, while phyA-null mutant exhibited skotomorphogenic development, such as long hypocotyl, closed cotyledons. The WT#4 and WT#6 transgenic seedlings showed typical light-dependent photomorphogenic development. Under the same condition, S598A PHYA transgenic lines complemented phyA null mutant, exhibiting FR-dependent photomorphogenic development. These results indicate that S598A PHYA is functional, complementing phyA-deficiency of phyA-201 mutant in Arabidopsis.
Previously oat PHYA was shown to be active in several dicot plants (Boylan and Quail, 1989; Boylan and Quail, 1991), mediating FR-HIR. In Arabidopsis , transgenic lines that overexpressing PHYA did not show any effects on adult morphology, while transgenic lines of tobacco and tomato exhibited several agronomic important traits such as dwarfism. When we grew the transgenic Arabidopsis plants that overexpress S598A PHYA, the transgenic lines showed dwarfism, while transgenic lines of PHYA were normal, compared to wild type (FIG. 5 ). The results suggest that S598A phyA is hyperactive to mediate adult dwarfism in Arabidopsis , compared to wildtype phyA. This trait is a potent agronomical target that can be applied to flowering plants to reduce cell/organ elongation resulting in improved agronomic values
EXAMPLES
Plant Materials and Growth Conditions
Seeds of pea plant was germinated and grown under sterile condition on the Murashige and Skoog (MS) media. The Arabidopsis thaliana ecotype Ler, phyA-201 mutants, and transgenic lines were grown on 0.5× MS medium. All Arabidopsis cultures were maintained in a controlled environment culture room at 26° C., 70% humidity and for the photoperiod of 16 hours. The Arabidopsis transformation was performed according to the simplified floral dip method, a well known technique to the art. For FR-high irradiance response, growth chamber (model E-30LED1; Percival Scientific, Inc., Boone, Iowa) equipped with FR light-emitting diode was used.
Enzymatic Treatments of DNA
DNA manipulations were carried out according to the standard procedures with some modifications whenever required. Restriction enzyme digestions were routinely done in 20 μl reaction volumes with an enzyme of 1-5 units per microgram DNA, and the mixtures were incubated at an appropriate temperature for 1-2 hours. Restriction enzyme digestion buffers used were those supplied by the manufacturer for each particular enzyme, unless specified otherwise. For ligation reactions, DNA fragments, either a digestion mixture or a PCR product, were first separated on 0.8-1.5% agarose gels, depending on the sizes of the DNA fragments of interest, and the desired DNA fragment was purified from the gel piece using either the GENECLEAN II Kit (BIO 101, Vista, USA) or the Gel Extraction Kit (Omega Biotek, Doraville, USA). Ligations were performed usually at the molar ratio of 1:1 to 1:3 in a 10 μl volume using the buffer supplied by the manufacturer, and the mixture was incubated at 13-16° C. for 10 minutes (for sticky-end ligations) or 30 minutes (for blunt-end ligations). T4 DNA ligase and its corresponding ligase buffer (NEB, Beverly, Mass., USA) were routinely used with 5-10 units of ligase in a 10 μl volume reaction. Polymerase chain reaction (PCR) was usually carried out 25 cycles, each with 1 minute denaturation at 94° C., 1 minute annealing at 60° C., and polymerization at 72° C. for 2 minutes per 1000 bases using the Pfu polymerase. For quantitative analysis, PCR was run 15-20 cycles, depending the gene expression levels, using the Taq polymerase (Promega, Madison, Wis.).
E. coli Transformation
For general cloning purpose, E. coli strain XL1-blue was routinely used as host cells for the transformation with plasmid DNAs. The competent E. coli cells were prepared in the laboratory and usually had an efficiency of 5×10 −6 to 10 −7 colonies per μg control vector DNA. Three to five microliter of the ligation mixture was usually used to transform 100 μl of the competent E. coli cells. After incubation on ice for 20 minutes, the cell-DNA mixture was heat-shocked at 42° C. for 1 minute, and 1 ml of SOC medium was added. The mixture was then gently rotated at 37° C. for 1 hour to render the cells recovered from damage, and 50-300 μl was spread on LB plates containing an appropriate antibiotic. The plates were incubated at 37° C. overnight or until positive colonies were visible.
Plasmid Isolation and Purification
Vector DNA was isolated routinely by the alkaline-SDS method from E. coli culture. A 1 ml (for high copy number plasmid) or a 10 ml LB-ampicillin culture (for low copy number plasmid) was routinely prepared for the small scale purification of plasmid DNA. For the large scale purification, TB medium (Terrific broth, 47.6 grams of TB mix per liter, Difco, Detroit, USA) which gives higher plasmid DNA yields, instead of LB medium, was used. To prepare plasmid DNA for DNA sequencing and Agrobacterium transformation, those isolated by the alkaline-SDS method was further purified using the Plasmid Miniprep Kit II (Omega Biotek, Seoul, KOREA).
The Expression of the Genes and Proteins in the Transgenic Plants
After the screening of the transgenic plants, RT-PCR technique was used to confirm the transcription of the introduced gene. Total RNAs from the transgenic seedlings were prepared by using RNeasy® Plant mini kit (Qiagen, 74903) and followed the standard procedure to generate cDNA by MMRV-reverse transcriptase (Strategene). 5 μg of total RNA was used for the cDNA synthesis. After the synthesis of the cDNA, PCR was performed to confirm the expression of the genes in the transgenic plants. The used primers were 5′-GAATGAAGAACAGATGAAGC-3′ (SEQ ID NO: 3) and 5′-TTGTCCCATTGCTGTTGGAGC-3′ (SEQ ID NO: 4). The products are the C-terminal gene fragments of oat phyA whose size is 581 base pairs. To check the expression of WT and MT proteins and the amounts, the western blot analysis was performed. The preparation of protein samples from the transgenic plants was done as follows: about 4 leaves from each plant were taken off before bolting, put the leaves between the water-soaked Whatman filter papers, and incubated the leaves for at least 12 hours under dark condition. The leave samples were grinded in the microcentrifuge tubes using sea sands and plastic rods. This protein extraction procedure were performed on the ice or in the cold room under the green light condition, and the used buffer for the protein extraction composed of 70 mM Tris (pH 8.3), 35% ethylene glycol, 98 mM (NH 4 ) 2 SO 4 , 7 mM EDTA, 14 mM Sodium metabisulfite, 0.07% polyethyleneimine and 2.8 mM PMSF (all from Sigma except ethylene glycol that is from Fisher). The extracted protein samples were centrifuged at 14,000 rpm and 4° C. for 15 min, and the supernatant were used as protein samples for the western blot analysis. The protein samples were quantified by using Bio-Rad protein assay kit (500-0001), and 50 ug of protein samples were loaded onto the 10% SDS-PAGE gels for the western blot analysis. The protein bands on the SDS-PAGE gel were transferred to PVDF membrane (Hybond-P, Amersham Phamacia Biotech), and the membrane was incubated with oat phyA-specific monoclonal antibody, oat22 and oat25, for 2 hours and developed by using ECL™ western blotting analysis system purchased from Amersham Phamacia Biotech (RPN 2108). For the detection of Arabidopsis phyA, P25 and mAA7 antibodies were added to the reaction.
Site-Directed Mutagenesis of S598A Oat PHYA
The full size of cDNA encoding Avena phytochrome A (phyA) from pFY 122 (Boylan and Quail, 1989) was cloned to pGEM®-11zf(+) (Promega P2411) by digesting with BamHI and EcoRI. After purifying the pGEM®-11zf(+) plasmids containing full-length oat phyA cDNA, the site-directed mutagenesis in order to create Ser598Ala Avena phyA mutant was performed by using GeneEditor™ in vitro site-directed mutagenesis system (Promega Q9280). The oligonucleotide sequence of mutagenic primer for the mutagenesis is phosphorylated-5′-GCGGGAAGCTGCT CTAGA TAACCAGATTGG-3′ (SEQ ID NO: 5). The bold and italic bases are the mutagenized ones from the original sequence 5′-AGTT-3′ (SEQ ID NO: 6) to 5′-GCTC-3′ (SEQ ID NO: 7), and the underlined sequence, 5′-TCTAGA-3′ (SEQ ID NO: 8) is a created XbaI restriction site which is used for the screening of the mutant gene. This new restriction site (XbaI) was introduced by silent mutation near the position to be mutated, allowing rapid and efficient screening for the mutant phyA (Ser598Ala mutant). After the mutagenesis, the mutagenized plasmids were purified and confirmed by XbaI digestion and DNA sequencing. DNA sequencing was done by using Sequenase version 2.0 DNA sequencing kit (Amersham, USB, US70770) with 35 S-ATP.
DNA Sequencing and Sequence Analysis
All cDNA and DNA fragments and the junctions of the expression vector constructs were confirmed by direct DNA sequencing on both strands. DNA sequencing was carried out using the ABI PRISM 310 Genetic Analyzer (Perkin Elmer, Foster City, USA) as described in the manufacturer's manual. For each sequencing run, about 500 ng of plasmid DNA and 2-4 picomoles of 15-17 mer sequencing primer were used. Computer-assisted sequence analysis was performed using the BLAST program (NCBI, USA).
Gel Electrophoresis of DNA
Agarose gel electrophoresis of DNA was usually performed using gels with a concentration range of 0.8-1.5%, depending on the size of the DNA fragments to be analyzed, using the TAE buffer (40 mM Tris-acetate, 1 mM EDTA, pH 8.0). Electrophoresis was performed at a constant voltage rage of 50-200, depending on the amount of DNA loaded onto wells, for a desired time or until DNA fragments were well separated. The gel was stained with 0.5 μg/ml ethidium bromide solution, visualized on an UV transilluminator, and photographed if required.
Construction of Plant Expression Vectors
The wild-type (WT) and Ser598Ala mutant (MT) genes were subcloned into the plant transformation vector, pBI121 (Clontech, Cat No. 6018-1: 13 Kb, CaMV 35S promoter etc.). For the subcloning, the vector (pBI121) was digested with BamHI and EcoICRI, and the WT and MT genes in pGEM®-11zf(+) were eluted by sequential enzyme treatment: EcoRI digestion, T4 polymerase treatment for making blunt ended DNA and BamHI digestion. Since the vector and the genes have one blunt end and one cohesive end, they can be ligated and subcloned. After the subcloning and confirmation of the genes in pBI121, the purified plasmids were used for the transformation into phyA deficient Arabidopsis thaliana . Since the vector has a kanamycin-resistant gene, the seeds having the transformed genes were selected by geminating on the agar plate containing 50 μg/ml kanamycin.
References
Bhoo S. H., Hirano T., Jeong H. Y., Lee J. G., Furuya M. & Song P. S. (1997) Phytochrome photochromism probed by site-directed mutations and chromophore esterification. J. Am. Chem. Soc., 119, 11717-11718
Boylan M. T. and Quail P. H. (1989) Oat phytochrome is biologically active in transgenic tomatoes. Plant Cell, 1, 765-773.
Boylan, M. T. and Quail, P. H. (1991) Phytochrome A overexpression inhibits hypocotyl elongation in transgenic Arabidopsis . Proc. Natl. Acad. Sci. USA, 88, 10806-10810.
Fankhauser, C., Yeh, K. C., Lagarias, J. C., Zhang, H., Elich, T. D., and Chory, J. (1999). PKS1, a substrate phosphorylated by phytochrome that modulates light signaling in Arabidopsis . Science 284, 1539-1541.
Lapko, V. N., Jiang, X. Y., Smith, D. L., and Song, P. S. (1997). Posttranslational modification of oat phytochrome A: Phosphorylation of a specific serine in a multiple serine cluster. Biochemistry, 36, 10595-10599.
Lapko, V. N., Jiang, X. Y., Smith, D. L., and Song, P. S. (1999). Mass spectrometric characterization of oat phytochrome A: Isoforms and posttranslational modifications. Protein Science, 8, 1032-1044.
Neff, M. M., Fankhauser, C., and Chory, J. (2000) Light: an indicator of time and place. Genes Dev. 14, 257-271.
Park, C. M., Bhoo, S.-H. and Song, P.-S. (2000) Inter-domain crosstalk in the phytochrome molecules, Cell Dev. Biol., 11, 449-456.
Quail, P. H., Boylan, M. T., Parks, B. M., Short, T. W., Xu, Y., and Wagner, D. (1995) Phytochromes: Photosensory perception and signal transduction. Science, 268, 675-680.
Shinomura, T., Nagatani, A., Hanzawa, H., Kubota, M., Watanabe, M., and Furuya, M. (1996). Action spectra for phytochrome A- and B-specific photoinhibition of seed germination in Arabidopsis thaliana . Proc. Natl. Acad. Sci. USA, 93, 8129-8133.
Smith H. & Whitelam G. C. (1997) The shade avoidance syndrome: multiple responses mediated by multiple phytochromes. Plant, Cell & Environ. 20, 840-844
Stockhaus, J., Nagatani, A., Halfter, U., Kay, S., Furuya, M., and Chua, N.-H. (1992) Serine-to alanine substitutions at the amino-terminal region of phytochrome A results in an increase in biological activity. Genes Dev. 6, 2364-2372.
Yeh, K. C., and Lagarias, J. C. (1998). Eukaryotic phytochromes: light-regulated serine/threonine protein kinases with histidine kinase ancestry. Proc. Natl. Acad. Sci. USA 95, 13976-13981. | The present invention includes modified phytochrome A (PHYA) nucleic acid molecules in which DNA sequences coding for “active site” amino acid residues have been mutated to generate hyperactive phytochromes. In particular; a serine/threonine residue at the hinge between the N- and C-terminal domains as well as at the N-terminal serine/threonine cluster of phytochromes (e.g., serine-598 and serine-7 in oat phytochrome A) for (a) Pr/Pfr-dependent phosphorylation and (b) dephosphorylation by a phytochrome phosphatase (PP2A) was substituted with alanine. (c) In addition, amino acid residues within the phytochrome chromophore pocket are mutated to generate the bathchromic shift of the Pr-absorption band of both wild type and above-mentioned mutant phytochromes. The plants with the bathchromically shifted absorption spectrum are expected to respond to the canopy and shade conditions for growth and greening responses to far-red light with greater efficiency than are the wild type plants with normal absorption band maxima. These mutative modifications confer hyperactivity to the far-red light responsive phytochromes A. Thus, the biological activity of the modified oat PHYA was shown to be hyperactive compared to wild type PHYA, characterized by its ability to reduce internode elongation of adult plants. Overexpression of the phytochrome phosphatase exhibits a suppressed growth with shorter internodes and belated flowering, qualitatively consistent with the phenotype of a ser598ala mutant oat phytochrome. The invention also includes plants having at least one cell expressing the modified PHYA, vectors comprising at least one portion of the modified PHYA nucleic acids, and methods using such vectors for producing plants with reduced stature. | 2 |
CROSS-REFERENCES TO RELATED APPLICATIONS
None.
FIELD OF THE INVENTION
The present invention relates to a magnetic enclosure for temporarily retaining documents, printed indicia, photographs or the like. More particularly, the present invention provides an enclosure that is created in an economical manner by laminating a magnetic material to a transparent sleeve created through the production process. The magnetic material serves as a backing member for mounting, displaying and for securing printed indicia, creative content or other material in a convenient to use fashion.
BACKGROUND OF THE INVENTION
There are a number of sleeves and other constructions that are available today for holding documents and displaying materials. These constructions can be produced in a number of configurations and may include a pair of plastic sheets, the combination of an opaque sheet and a transparent sheet as well as the use of partially translucent sheets.
In a construction that utilizes two transparent sheets, the sheets are usually aligned with one another and are then bonded or fused either through the use of heat or adhesive along three sides. This creates an opening, usually along the top end edge that can be used to insert the material to be held within the sleeve. With a pair of transparent sheets, a two-sided document can be inserted and is visible on each of the faces of the document, however, if the sleeve is attached to an opaque structure only one side of the document to be displayed is visible.
A similar construction may be produced using the combination of one transparent sheet and one opaque sheet. In such an arrangement, the sheets are again aligned with one another and typically three edges are bonded or fused together to create an enclosure. The opening can be along any edge, but again as provided above, the opening is commonly found along the top end edge. As one of the sheets is opaque, the inserted material is visible only on a single side.
As with each of the foregoing constructions, while the inserted material is viewable, at least on one side, the user of the assembly must then still either pin, tape or otherwise adhere or affix the sleeve to a wall, bulletin board, appliance, structure or the like in order for the passersby to see or witness the material that has been inserted. In addition, such constructions are often flimsy, due to the materials used in fabricating the construction and depending upon the size and/or thickness of the material to be inserted, use of the sleeve can be awkward.
In a number of applications or situations it is generally desirable to be able to temporarily hang or display indicia, creative material or the like. Typically, this is done through the use of repositional or removable adhesives, tapes, tacks and the like. With adhesives, a residue can be left, particularly if the sleeve is left for a prolonged period of time. Likewise, tape may also leave a residue and may be difficult to peel off from the structure to which it has been applied. Tacks of course, while not leaving an adhesive residue will create holes or punctures in the structure that they are used with and after repeated hangings a number of holes will be produced, requiring patching and/or painting to again conceal. The foregoing can be avoided through the use of a bulletin board, cork panels or the like, but this however limits positioning of the display to the location of such panels. In addition, the user is required to purchase the additional structure in order to prepare the display.
Other mechanisms by which to hang or display indicia or creative material include the use of individual magnets, which may be decorative in appearance. Magnets are particularly suitable in today's office environment as cubicle walls and the like often have components which are susceptible to receiving magnets. However, in order to use individual magnets, one must first locate a magnet, which often means removing a magnet that was supporting something else, likely to the detriment of the person who had used the magnet in the first place. Alternatively, the magnet may be used to hold up numerous displays, making the area looked cluttered. In addition, with a build-up of sheet material or thickness beneath the magnet, the strength of the magnetic forces is also diminished and as such the materials supported by the magnet as well as the magnet itself may fall to the ground.
A still further problem with magnets, is that when decorative or theme based magnets are used, particularly in an office or communal environment, the decorative elements may be distasteful or even offensive to individuals who may view the display. In addition, use of colorful magnets can also detract from the message that the magnets are being used to display.
Use of magnet sign supports is generally well known in the signage industry but surprisingly, such devices have not found their way into the office environment or small or home office setting. This is likely due to the complexity and cost associated with such products thereby limiting the potential applications. Such magnetic backing material may include a set of preformed ridges that can be used to temporarily hold or support a plastic film or even the material to be displayed itself. In the former instance, the film is inserted into the ridged areas thereby creating something of a sleeve into which the material to be displayed can be inserted. However, with this construction as neither the plastic sheet material nor visual indicia is held in position, the sheet and indicia is subject to loss due to slipping from the ridged area. Moreover, the manufacture of such ridged areas is expensive in that creating the ridges and sleeve fixtures adds additional steps to the process of producing the construction.
Other uses of magnetically backed display material include magnetic material having a pre-coated layer of adhesive disposed on the material, which is in turn covered by a release liner. This material has a width of about ¼″ to around ½″ and resembles a roll of adhesive tape in that the product is often wound on itself The user, cuts a piece of the magnetic material to the desired length and then removes the release liner and applies the magnetic material in strips to the back of the material to be displayed. For example, a magnetic strip could be applied to one of the prior art type sleeves discussed above. Producing such a construction is however time consuming, in that it requires cutting of the magnetic material to length, removing the release liner material and positioning of the magnetic strips to complete the assembly. While this ad hoc approach may be a suitable temporary arrangement, it does not solve the long term need of the user, as the adhesive bond between the substrate and the magnetic material mail fail over time causing the display to fall to the ground.
What is needed therefore, is a display assembly, that can easily accommodate and confine material and indicia to be viewed and that overcomes the drawbacks set forth above. In addition, the assembly must be one that can be produced in an economical and efficient manner; such as through an in-line press application that facilitates the production of the display assembly of the present invention.
BRIEF SUMMARY OF THE PRESENT INVENTION
The embodiments of the present invention described below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of the present invention.
In one embodiment of the present invention, a laminated construction for containing visual material to be viewed is described and includes a magnetic layer, which has first and second end edges and first and second longitudinally extending sides. The magnetic layer has a predetermined size and configuration and first and second faces that are opposite one another. A first adhesive layer is disposed in a pattern on the magnetic layer on one of the first and second faces. A first imageable layer is provided and has first and second faces, first and second transversely extending end edges and first and second longitudinally extending sides. One of the faces is placed in contact with the first adhesive layer that has been applied or coated on the magnetic layer. A second adhesive pattern is also provided and is applied to the other face of the first imageable layer in a pattern that is distinct from the pattern of the first adhesive layer. A second imageable layer is provided and includes first and second faces, first and second longitudinally extending sides and first and second transversely extending end edges. The construction that is formed when the second imageable layer is adhered to the first imageable layer by the second pattern of adhesive creates an open space that has a size and configuration which is less than the size and configuration of magnetic layer. The open space is used to contain the document or other visible indicia.
In a further embodiment of the present invention, a method of making laminated construction for containing visual material to be viewed is described and includes the steps of initially providing a web of magnetic material having first and second faces. Then a pattern of adhesive is coated on one of the faces of the web of magnetic material. Next, a first imageable layer of material having first and second faces is advanced to an assembly point whereupon the layer is placed into contact with the first pattern of adhesive. A second pattern of adhesive is applied to the other face of the imageable sheet opposite that of the face in contact with the first pattern of adhesive. A second layer of material with first and second faces is applied to the second adhesive pattern such that the imageable layer, second layer and second pattern of adhesive form a pocket to retain visual material.
A still further embodiment of the present invention is described and includes a method of producing a magnetic display form. This embodiment includes the steps of initially providing a laminate that has magnetic properties and a first face and a second face, one of the faces is capable of receiving print or images. Next, a pattern of adhesive is applied to the laminate on one of the first and second faces. The pattern of adhesive has first and second portions. A first web of material is advanced in a machine or first direction and has a first dimension. A second web of material is also advanced in a machine direction and has a second dimension that is different than the first dimension. Then the first web of material is adhered to the first portion of the pattern of adhesive and the second web is applied or adhered to the second portion of the pattern of adhesive. An overlapping arrangement is created between the first and second webs of material so as to provide an accessible opening to a cavity formed between the first and second webs and the laminate.
In yet a still further embodiment of the present invention a substantially quadrate, display assembly is described and includes a magnetic material having a thickness ranging from about 10 to 25 mils and having a first face and a second face. The magnetic material is capable of traversing an in-line press. The substantially quadrate assembly also includes sheet stock that is adhered to a magnetic material and can receive indicia. The sheet stock is selected from a group of materials including bond paper, tag stock and combinations thereof and the sheet stock can transverse an in-line press in conjunction with the magnetic layer. The assembly also includes a transparent layer that has a thickness of greater than about 2 mils and is adhered to the sheet stock through a pattern of adhesive. The sheet stock and transparent layer are adhered together in such a manner so as to create a space between the sheet stock and the transparent layer, and the space has a size less than the sheet stock. The magnetic layer, sheet stock and transparent layer once formed into a laminated construction can be produced from an in-line configuration.
These and other objects of the invention will become clearer from a review of the figures and detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
These, as well as other objects and advantages of this invention, will be more completely understood and appreciated by referring to the following more detailed description of the presently preferred exemplary embodiments of the invention in conjunction with the accompanying drawings, of which:
FIG. 1 depicts a front elevation of the visual display form prepared in accordance with the present invention;
FIG. 2 is a cross sectional view of FIG. 1 shown along line 3 — 3 depicting the layers of the present invention;
FIG. 3 is cross sectional view of FIG. 1 shown along line 3 — 3 , illustrating a further embodiment of the present invention;
FIG. 4 a front elevation illustrating the layers adhered to one another;
FIG. 5 is a schematic view of an exemplary embodiment used in the construction of the present invention;
FIG. 6 is a further schematic view of the process depicted in FIG. 5 ;
FIG. 7 is a schematic depiction of a process used in the preparation of a further embodiment of the present invention; and
FIG. 8 is a further schematic of the process used in FIG. 7 above.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is now illustrated in greater detail by way of the following detailed description, but it should be understood that the present invention is not to be construed as being limited thereto.
The present invention provides for a much more economical and efficient manner of producing a visual display form construction having an internally formed pocket, cavity, recess or the like on a substrate or laminate that has magnetic properties. The present invention is directed to both the product configuration as well as the methods for producing the assembly, including the ability to produce the assembly in an in-line configuration.
Turning now to FIG. 1 , an exemplary embodiment of the present invention is depicted generally by reference to numeral 10 . The assembly 10 has first and second transversely extending end edges 12 and 14 , respectively, and first and second longitudinally extending sides 16 and 18 , respectively. As illustrated in FIG. 1 , the assembly 10 has been provided with rounded or die cut corners, however, it should be understood that the invention may have squared off edges, diagonal corners and the like. In addition, the configuration of the present invention may be configured into any number of geometric and animate shapes. The manufacturing process described below is adapted to producing such shapes by altering the patterns of adhesive that are applied to the construction and die cutting the assembly 10 into the desired shape as will be understood by those having ordinary skill in the art.
FIG. 2 provides a cross section of assembly 10 . The base of the assembly 10 comprises a magnetic layer 20 , which has first and second faces 21 and 23 , respectively. The magnetic layer 20 , as with each of the other layers ( 22 , 24 and 28 ) of the construction herein, excluding the adhesive patterns, each have first and second transversely extending end edges and first and second longitudinally extending sides. Each of the sides and end edges held generally within the confines of the side and edges of assembly 10 shall be simply referred to with respect to the numerical limitations provided above 12, 14, 16 and 18.
The magnetic material may be purchased from Flexmag Industries, of Marietta Ohio and may have a thickness ranging from 5 to 30 mils, with 10 to 25 mils being preferred and approximately 15 mils being more preferred.
The second face 23 of the magnetic layer 20 has a pattern of adhesive 22 applied to the second face 23 . The adhesive layer or pattern 22 may include generally any permanent type adhesive such as pressure sensitive adhesives, acrylic based adhesives, hot melts, cold glues, etc. One such supplier of permanent adhesives is HB Fuller of St. Paul, Minn.
The pattern or layer of adhesive 22 may be coated or applied in any number of configurations. For example, the adhesive 22 may cover the entire face 23 of the magnetic layer 20 , may be applied in a spot or other geometric pattern such as lines or stripes. The adhesive layer 22 must however be coated in a sufficient manner and amount so as to provide adequate coverage and adhesion between the layers of the assembly.
Still referring to FIG. 2 , an imageable layer 24 is then applied over the pattern of adhesive 23 . The term “imageable” as used herein, includes a substrate that is capable of receiving print, indicia or images such as through the use of ink jet, dot matrix, electrostatic and other non-impact printing or imaging means. In addition, the term includes a substrate to which a coating may be applied so as to make it more receptive to receiving print or images. The imageable layer has first and second faces 25 ″ and 25 ′, respectively. The imageable layer 24 may be selected from any number of appropriate materials such as 20–24 pound bond paper, tag or card stock, printable films such as a polyethylene based film or the like. The material for the imageable layer 24 should be selected for its ability to receive toner or accept ink. However, it should be understood that the layer 24 need not be provided with any printing or imaging and may remain blank. In addition, layer 24 may be colored so as to provide a background or contrast to the visual indicia to be inserted within the construction.
Where the imageable layer 24 is provided with printing or images, the printing or imaging may include instructions on use of the form, complimentary graphics to the intended insert or the like. Complimentary graphics may include printed pattern, warning indicia such as the terms “NOTICE” or “CAUTION” or the like. Such printing can be provided off line from the manufacturing operation of the assembly 10 and accomplished by electrostatic print engines, ink jet, and the like. When accomplished apart or away from the manufacturing apparatus, the printing may be done in repetitive patterns so that during the cutting and processing of the assembly 10 , it is not significant where the imageable layer 24 is cut or separated from the web on which it is printed.
A second layer or pattern of adhesive 26 is then coated or applied and positioned on the second face 25 ′ of the imageable layer 24 . Unlike the first pattern of adhesive 22 , the second pattern 26 is applied in a “U” or an inverted “U” shaped configuration. This is required so as to facilitate the preparation of a cavity, recess, pocket or the like so as to be able to receive the material to be displayed in the configuration. The second pattern 26 has a width of about ¼ of an inch to about ½ of an inch with about ⅜ of an inch being preferred. The width of the adhesive pattern 26 must be sufficient in order to prevent the inserted material from poking through the edge of the construction so that rips or weaknesses are not created in the assembly 10 . That is, if a substantially rigid piece is inserted into the assembly 10 , the piece may have a sharp corner that could puncture or break through the pattern of adhesive.
FIG. 2 also illustrates the imposition of the next layer 28 on the assembly 10 . The layer 28 again may be imageable so that complimentary graphics, colors, or indicia can be provided to the construction to highlight or facilitate the communication of the message of the insert to be provided in the assembly 10 .
Layer 28 is adhered to the assembly 10 through the pattern of adhesive 26 on its first face. The second face would then serve as the visible exterior face of the layer 28 and hence assembly 10 .
The layer 28 is desirably at least translucent if not transparent, which is preferred. In addition, the layer 28 may be provided with only portions of the layer being transparent with other areas of layer 28 being only translucent or opaque. In this way, use instructions can be provided on the sides of the insert, and would be concealed from view due to the translucence or opaque characteristics of the layer 28 .
The combination of layer 28 , adhesive pattern 26 and layer 24 form to create a pocket, recess, cavity or the like 30 , which can accommodate a variety of inserts. The size of the cavity would vary depending upon the size of the layers 20 , 24 and 26 , respectively. For example, if the layers 20 , 24 and 26 were each 8½ by 11 inches, then the interior cavity 30 would be approximately 7½″ by 10½″. Obviously, other sizes and dimensions are possible.
In still a further embodiment layer 28 could be provided with a patterned transparency so as to serve as part of a sweepstakes or promotion. Users or recipients of a game piece would bring the game piece to a predetermined location and insert the piece into the assembly. The patterned transparency would illustrate whether the consumer or recipient revealed a specific code or message such as “WINNER” or a combination that may unlock a prize.
Turning now to FIG. 3 , a further embodiment of the present invention is provided. In this embodiment, the construction of the layers is similar to that as depicted above, however, layer 28 is now portioned into first and second portions, 28 A and 28 B, respectively. As depicted in the drawing, portion 28 A is substantially smaller than portion 28 B, but may be approximately equal to portion 28 B, that is each portion may be between 50 to 60% of the length and width of layer 28 . For greater clarity, and in order to create the overlapping arrangement, if one portion were provided that made up 50% of the length and width of the layer 28 , then the other portion would have to be at least slightly larger than the other portion, approximately 51–100% of the size of the sheet so that an overlap was created between the two portions and more preferably about 51 to about 65%. In an exemplary embodiment, the amount of overlap ranges from at least ⅛ of an inch to about ¾ of an inch with about ⅜ of an inch being preferred. That is, one of sheets 28 A or 28 B would preferably have from 51% to 65% of the size of the other of sheets 28 A or 28 B.
FIG. 4 provides a front elevational view showing overlapping portions 28 A and 28 B. Reference to numeral 20 in this embodiment includes not only the magnetic layer by also a laminated magnetic layer having a imageable layer applied thereover.
The overlap created by portions 28 A and 28 B in effect provides a resealable enclosure for the material to be inserted in the cavity 30 . In addition, in a further embodiment of the present invention, the second pattern of adhesive 26 may then be provided in an almost full perimeter seal. That is, the adhesive extends nearly substantially entirely around the perimeter of the sheet or layer 26 . The break in the adhesive seal corresponds with the area of the overlap of the assembly 10 . In this embodiment, a pouch like structure is created wherein the inserts provided in cavity 30 cannot fallout regardless of the positions of the assembly. This is do to the nearly complete perimeter seal retains the insert in a secure position and the overlapping flap create a closure that requires manipulation in order for the material to be removed from the interior.
In the present invention, either one or both of the layers 24 or 28 may be printed with indicia or images, such as graphics. The printing or imaging may be complimentary or supplemental to the material to be inserted. The printing on layer 24 may also be viewable through changing the pattern of transparencies on layer 28 , so that a changeable sign or background can be created by the construction without the need to create an entirely new assembly 10 .
Turning now to FIG. 5 , where an exemplary schematic is provided for producing the present invention. In this example, a continuous web of magnetic material 20 is provided. The present invention may also be made in a cut sheet arrangement, wherein the difference includes supplying a stack of cut sheets of magnetic material to the manufacturing operation. It should also be understood that the web of material may be a laminated construction in which a magnetic sheet has an imageable layer already adhered to one side of the web.
The web of magnetic material 20 is provided to a rotary press 100 where a pattern of adhesive 102 is applied to the web of material 20 . Where the web is provided in a non-laminated arrangement, the web 20 first has an imageable layer applied to the layer through the use of a permanent adhesive as described above and is then supplied to the rotary press 100 .
Once the pattern of adhesive 102 is applied to the web 20 , the web 20 is provided to a nip roller 104 . It should be understood that depending on the configuration of the final assembly 10 , the adhesive pattern 102 may comprise a “U” shaped pattern, an inverted “U” or other shapes as are necessary, including a perimeter seal and a nearly complete perimeter seal.
At the nip roller 104 , the web of material 20 having the pattern of adhesive 102 applied thereto is joined with a second layer 28 that is supplied from a continuous web arrangement. Again, in a cut sheet embodiment, previously cut sheets of layer 28 would be fed into a cooperative arrangement with the layer of magnetic material 20 .
The nip roller 104 causes the web of material 20 to be bound or adhesively secured to the second layer 28 due to the adhesive pattern 102 . The web of material continues to travel in a machine direction and is severed into individual assemblies 10 by a die or other cutting mechanisms 106 . After the cutting or severing operation, the individual assemblies are collected for distribution (not shown).
Now with respect to FIG. 6 , a side view of the schematic apparatus as described above in reference to FIG. 5 is provided. The web of magnetic material 20 is advanced in a machine direction. As provided previously, the web 20 may be provided in a laminated or non-laminated configuration, that is, with or without a layer of imageable material thereon. The web 20 of material is passed through a rotary press 100 that applies a pattern of adhesive 102 to the web 20 . The coated web 20 may then be passed through an UV treatment zone (curing, drying) 108 to cure the adhesive. Next, the web 20 travels in the machine direction through a nip roller 104 where layer 28 is bound or adhesively secured to the web 20 to create a further laminated construction. The laminated construction may then pass through a second UV station 110 and then finally to a die cutting or severing station 106 after which the individual assemblies 10 are created and then stacked for distribution (not shown).
Turning now to FIG. 7 , where a further illustrative embodiment of the present invention is presented. Again a web 220 of magnetic material is moved in a machine direction and passed to a rotary press 200 to apply a pattern of adhesive 202 . The coated web is then passed to a nip roller 204 where first and second portions, 28 A and 28 B, respectively, of a second layer are provided. The nip roller 204 presses the first and second portions of the layer 28 into contact with the adhesive pattern 202 , thereby forming an adhesive bond and a laminated structure. The structure is then forwarded to a die cutting or severing step 206 where the web is separated into individual pieces.
FIG. 8 provides an alternative configuration for the method of the present invention. In FIG. 8 , unwinds are provided for each of the first and second portions 28 A and 28 B of the present invention. The first and second portions 28 A and 28 B are provided in an overlapping arrangement so as to create a resealable area that prevents the inserts from escaping from the cavity 30 as provided in FIG. 1 .
The overlapping arrangement of the first and second portions 28 A and 28 B of the present invention may also be provided with a repositional adhesive or a cohesive seal (mating patterns of adhesive that bond only to one another) so that a further secure closure can be provided. In this embodiment, one of the first and second portions 28 A and 28 B would be provided in a pre-coated arrangement and fed into the manufacturing arrangement as provided in accordance with the present invention.
It will thus be seen according to the present invention a highly advantageous visual display form has been provided. While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it will be apparent to those of ordinary skill in the art that the invention is not to be limited to the disclosed embodiment, that many modifications and equivalent arrangements may be made thereof within the scope of the invention, which scope is to be accorded the broadest interpretation of the appended claims so as to encompass all equivalent structures and products. | The present invention relates to a magnetic enclosure for temporarily retaining documents, printed indicia, photographs or the like. More particularly, the present invention provides an enclosure that is created by laminating a magnetic material to a transparent sleeve created through the production process. The magnetic material serves as a backing member for mounting, displaying and securing printed indicia, creative content or other material in a convenient to use fashion. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to a receiver of a code-division multiple access system and, in particular, to a receiver of a code-division multiple access system intended to improve a reception quality.
In a conventional mobile communication system such as a mobile telephone, use has been made of a multiplexing system such as a time division multiple access (TDMA) system or a frequency division multiple access (FDMA) system. However, in response to a growing demand for effective use of frequencies following an increase in number of subscribers and for multimedia communications, attention is directed to a code division multiple access (hereinafter abbreviated to CDMA) system as a multiplexing system for a next-generation mobile telephone. The CDMA system is a technique for simultaneously carrying out a plurality of communications by the use of signals in a same frequency band by means of the spread spectrum technique. In a CDMA mobile communication system using the above-mentioned technique, a plurality of users occupy a same frequency and a same time and modulate communication data by the use of spread codes assigned to the users to identify the users. The spread codes of the users are orthogonal to one another. Therefore, at a receiving side a multiplexed signal obtained by multiplexing all user's communication data is multiplied by a spread code used by each user in a same phase so as to extract communication data of a desired user.
In the CDMA mobile communication system, a communication quality is determined by orthogonality of communication data signals of all users multiplexed In the same frequency. Practically, however, due to variation in a propagation condition, the orthogonality can not completely be maintained. Therefore, when the signal of the desired user is demodulated a signal component of another user is undesiredly contained to result in deterioration in signal quality. In order to avoid the deterioration in signal quality, the receiving side measures a ratio between a signal reception level and an interference reception level for the desired user and requests a transmitting side to change transmission power so as to satisfy a predetermined ratio. In this approach, a transmission level is increased at the transmitting side in order to maintain a predetermined signal-to-interference ratio (hereinafter abbreviated to SIR) at a CDMA receiver in the CDMA mobile communication system. However, increase in transmission level prevents the reduction in power consumption at a terminal and the improvement in degree of multiplexing into the same frequency. In order to solve the above-mentioned problem, attention is directed to an interference removing technique. In the interference removing technique, an interference wave, i.e., a signal component other than that of a desired user is removed from a communication data signal received. Thus, it is possible to improve a reception signal quality even in a low SIR condition.
Hereinafter, description will be made of a CDMA receiver using the interference removing technique. Herein, it is assumed that the CDMA receiver performs an interference removing operation of a multistage type in which interference removal is repeatedly carried out in three stages for three users.
FIG. 1 shows the structure of a conventional CDMA receiver for carrying out interference removal in a multistage fashion. The CDMA receiver comprises a reception timing detecting section 10 for detecting reception timings of three users and, in correspondence to the reception timings, interference estimating sections in each stage. The interference estimating sections includes first- through third-stage interference estimating sections 11 11 through 11 13 corresponding to the reception timing of a first user, first through third-stage interference estimating sections 11 21 through 11 23 corresponding to the reception timing of a second user, and first- through third-stage interference estimating sections 11 31 to 11 33 corresponding to the reception timing of a third user. The CDMA receiver further comprises residual signal producing sections 12 1 and 12 2 .
A multiplexed signal 13 received by the CDMA receiver is supplied to the reception timing detecting section 10 , the first-stage interference estimating sections 11 11 through 11 31 , and the residual signal producing section 12 1 . The multiplexed signal 13 is a frame signal composed of a plurality of slots. At a predetermined position in the frame, a pilot symbol as predetermined pattern data is added before or after an information symbol of a predetermined length. The reception timing detecting section 10 detects the pilot symbol added to the multiplexed signal 13 to detect data reception timings of desired users. The reception timings thus detected are supplied as reception timings 14 1 through 14 3 to the first-stage interference estimating sections 11 11 through 11 31 , the second-stage interference estimating sections 11 12 through 11 32 , and the third-stage interference estimating sections 11 13 through 11 33 individually for the users, i.e., individually for the reception timings. In synchronism with the reception timings 14 1 through 14 3 detected by the reception timing detecting section 10 for the individual users, the first-stage interference estimating sections 11 11 through 11 31 multiply the multiplexed signal 13 by spread codes assigned to the individual users to extract data signals of the desired users, respectively. The data signals thus extracted are supplied as user signals 15 1 through 15 3 to the second-stage interference estimating sections 11 12 through 11 32 in a subsequent stage, respectively. In addition, the first-stage interference estimating sections 11 11 through 11 31 multiply the extracted user data signals again by the spread codes assigned to the users. Thus, signal components of the users contained in the multiplexed signal 13 are reproduced to obtain reproduction signals 16 1 through 16 3 which are supplied to the residual signal producing section 12 1 . The residual signal producing section 12 1 is supplied with the multiplexed signal 13 in addition to the reproduction signals 16 1 through 16 3 and produces a residual signal 17 obtained by subtracting the reproduction signals 16 1 through 16 3 from the multiplexed signal 13 . The residual signal 17 is used as an input signal to be subjected to interference removal in the second stage.
The residual signal 17 is supplied to the second-stage interference estimating sections 11 12 through 11 32 and the residual signal producing section 12 2 .In synchronism with the reception timings 14 1 through 14 3 detected by the reception timing detecting section 10 for the individual users, the second-stage interference estimating sections 11 12 through 11 32 multiply the residual signal 17 supplied thereto by the spread codes individually assigned to the users to despread the residual signal. Resultant signals (or despread signals) are weak in signal level. Therefore, in order to minimize errors produced in transmission-path estimation required upon demodulation, the user signals 15 1 through 15 3 supplied from the first-stage interference estimating sections 11 11 through 11 31 are added to the resultant signals to produce added user signals increased in ratio of the signal components of the desired users. Thus, data signals of the desired users are extracted. The data signals thus extracted are supplied as user signals 18 1 through 18 3 to the third-stage interference estimating sections 11 13 through 11 33 in a subsequent stage, respectively. In addition, the second-stage interference estimating sections 11 12 through 11 32 subtract, from the user data signals extracted thereat as demodulation signals, signal components corresponding to the user signals 15 1 through 15 3 previously added and multiply results of extraction again by the spread codes assigned to the users, respectively. Thus, signal components of the relevant users contained in the residual signal 17 are reproduced as reproduction signals 19 1 through 19 3 which are supplied to the residual signal producing section 12 2 . The residual signal producing section 12 2 is supplied with the residual signal 17 in addition to the reproduction signals 19 1 through 19 3 and produces a residual signal 20 obtained by subtracting the reproduction signals 19 1 through 19 3 from the residual signal 17 . The residual signal 20 is used as an input signal to be subjected to interference removal in the third stage.
Likewise, the third-stage interference estimating sections 11 13 through 11 33 extract desired user signals for the residual signal 20 and produce demodulation signals 21 1 through 21 3 of the desired users corresponding to the user signals 16 1 through 16 3 and 18 1 through 18 3 produced by the first- and the second-stage interference estimating sections 11 11 through 11 31 and 11 12 through 11 32 , respectively. In this event, the residual signal 20 approaches nearer to zero than the residual signal 17 so that the third-stage interference estimating sections 11 13 through 11 33 produce the demodulation signals 21 1 through 21 3 from the added user signals after the interference is removed at maximum, respectively.
The above-mentioned technique related to the CDMA receiver is disclosed, for example, in Japanese Unexamined Patent Publication (JP-A) No. H10-190494 “INTERFEERENCE CANCELLER AND CHANNEL ESTIMATION”.
However, in the conventional CDMA receiver already proposed, interference is not removed from the multiplexed signal itself supplied to the reception timing detecting section. Therefore, the reception timings of the desired users are detected from the reception signal containing interference waves at a great ratio. As a consequence, it is difficult to detect accurate reception timings. Furthermore, since the interference of the reception signal is removed with reference to such inaccurate reception timings, the reception quality is deteriorated to cancel the effect of interference removal.
SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide a CDMA receiver which enables detection of accurate reception timings even in a condition that an SIR is low.
A CDMA receiver to which this invention is applicable is for receiving, as a reception signal, a signal given by subjecting a data signal comprising predetermined pattern data to spread modulation by the use of a spread code.
According to an aspect of this invention, the receiver comprises:
correlation value data producing means for producing correlation value data obtained by multiplying the reception signal by the spread code and the predetermined pattern data;
signal-to-interference ratio calculating means for calculating a signal-to-interference ratio of said reception signal; and
reception timing determining means for determining a reception timing of said predetermined pattern data in response to said correlation value data and said signal-to-interference ratio.
Preferably, the reception timing determining means determines the reception timing such that the maximum value of the correlation value data exceeds a predetermined first threshold value and that the signal-to-interference ratio exceeds a predetermined second threshold value when the correlation value data have the maximum value.
The signal-to-interference ratio calculating means may calculate the signal-to-interference ratio from the reception signal and the correlation value data produced by the correlation value data producing means.
According to another aspect of this invention, the receiver comprises:
correlation value data producing means for producing, at each sampling point within a predetermined time range, correlation value data obtained by multiplying the reception signal by the spread code and the predetermined pattern data;
correlation value data memorizing means for memorizing, in correspondence to the above-mentioned each sampling point, the correlation value data produced by the correlation value data producing means;
signal-to-interference ratio calculating means for calculating a signal-to-interference ratio of the reception signal;
signal-to-interference ratio memorizing means for producing an interpolating signal-to-interference ratio for the signal-to-interference ratio calculated by the signal-to-interference ratio calculating means for each sampling point within the time range based on a reception timing at which the signal-to-interference ratio is calculated and for memorizing the interpolating signal-to-interference ratios in correspondence to the above-mentioned each sampling point;
retrieving means for retrieving maximum correlation value data among the correlation value data memorized in the correlation value data memorizing means;
correlation value data judging means for judging whether or not the maximum correlation value data retrieved by the retrieving means exceed a predetermined first threshold value;
ratio judging means for judging, when the correlation value data judging means judges that the maximum correlation value data exceed the first threshold value, whether or not a particular signal-to-interference ratio memorized in the signal-to-interference ratio memorizing means in correspondence to a particular sampling point of the maximum correlation value data exceeds a predetermined second threshold value; and
reception timing determining means for determining, when the ratio judging means judges that the particular signal-to-interference ratio exceeds the second threshold value, a reception timing corresponding to the particular sampling point as a reception timing of the predetermined pattern data.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a view showing the structure of a conventional CDMA receiver;
FIG. 2 is a view showing the structure of a CDMA receiver according to a first embodiment of this invention;
FIG. 3 is a block diagram showing a characteristic part of the structure of a first-stage interference estimating section in the first embodiment;
FIG. 4 is a block diagram showing a characteristic part of the structure of a second-stage interference estimating section in the first embodiment;
FIG. 5 is a block diagram showing a characteristic part of the structure of a reception timing detecting section in the CDMA receiver according to the first embodiment;
FIG. 6 is a view for describing a table structure of a correlation value table in the first embodiment;
FIG. 7 is a view for describing a table structure of an SIR information table in the first embodiment;
FIG. 8 is a flow chart showing the content of determination of a reception timing in a reception timing determining portion in the first embodiment; and
FIG. 9 is a block diagram showing a characteristic part of the structure of a reception timing detecting section of a CDMA receiver according to a second embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now, this invention will be described in detail in conjunction with several embodiments.
First Embodiment
FIG. 2 shows the structure of a CDMA receiver according to a first embodiment of this invention. The CDMA receiver in the first embodiment is a CDMA receiver utilizing a multistage-type interference removing technique of repeating interference removal in three stages for three users. However, the number of users and the number of stages are not restricted at all. The CDMA receiver in the first embodiment comprises a reception timing detecting section 30 for detecting reception timings for three users, respectively, and interference estimating sections in each stage in correspondence to the reception timings. The interference estimating sections include first- through third-stage interference estimating sections 31 11 through 31 13 corresponding to the reception timing of the first user, first- through third-stage interference estimating sections 31 21 through 31 23 corresponding to the reception timing of the second user, and first- through third-stage interference estimating sections 31 31 through 31 33 corresponding to the reception timing of the third user. The CDMA receiver further comprises residual signal producing sections 32 1 and 32 2 .
A multiplexed signal 33 received by the CDMA receiver is supplied to the reception timing detecting section 30 , the first-stage interference estimating sections 31 11 through 31 31 , and the residual signal producing section 32 1 . The multiplexed signal 33 is a frame signal composed of a plurality of slots. At a predetermined slot of the slots in the frame signal, a pilot symbol as predetermined pattern data is added before (or after) an information symbol (as information data) of a predetermined length. The reception timing detecting section 30 is supplied with SIR information 34 1 through 34 3 from the first-stage interference estimating sections 31 11 through 31 31 , respectively. The SIR information 34 1 through 34 3 are SIRs measured in correspondence to the reception timings. By detecting the pilot symbols added to the multiplexed signal 33 , the reception timing detecting section 30 corrects the data reception timings detected for the desired users with reference to the SIR information 34 1 through 34 3 corresponding thereto. Reception timing information 35 1 through 35 3 thus corrected are supplied to the first-stage interference estimating sections 31 11 through 31 31 , the second-stage interference estimating sections 31 12 through 31 32 , and the third-stage interference estimating sections 31 13 through 31 33 .
The first-stage interference estimating sections 31 11 through 31 31 are adapted to produce reception timings obtained by preliminarily compensating a processing delay in the reception timing detecting section 30 and other internal propagation delays, and to correct reception timings as demodulation timings with reference to the reception timing information 35 1 through 35 3 supplied thereto for individual users. At the reception timings thus corrected, the first-stage interference estimating sections 31 11 through 31 31 carry out demodulation of the multiplexed signal 33 in correspondence to the users by multiplying the multiplexed signal 33 by spread codes assigned to the individual users. The demodulated data are supplied as reception data 36 1 through 36 3 of the desired users to the second-stage interference estimating sections 31 12 through 31 32 as a next stage. In addition, the first-stage interference estimating sections 31 11 through 31 31 again uses the spread codes assigned to the individual users to reproduce signal components of the relevant users contained in the multiplexed signal 33 . The signal components thus reproduced are delivered as reproduction signals 37 1 through 37 3 to the residual signal producing section 32 1 . The residual signal producing section 32 1 is supplied with the multiplexed signal 33 in addition to the reproduction signals 37 1 through 37 3 and produces a residual signal 38 obtained by subtracting the reproduction signals 37 1 through 37 3 from the multiplexed signal 33 . The residual signal 38 is used as an input signal to be subjected to interference removal in the second stage.
The residual signal 38 is supplied to the second-stage interference estimating sections 31 12 through 31 32 and the residual signal producing section 32 2 . In synchronism with the reception timings for the individual users. The second-stage interference estimating sections 31 12 through 31 32 carry out despreading by multiplying the residual signal 38 supplied thereto by the spread codes individually assigned. Resultant signals have a small signal level.
Therefore, in order to minimize errors produced in transmission-path estimation required upon demodulation, the reception data 36 1 through 36 3 supplied from the first-stage interference estimating sections 31 11 through 31 31 are added thereto to produce added user signals increased in ratio of signal components of the desired users. Thus, data signals of the desired users are extracted. The data signals thus extracted are supplied as reception data 39 1 through 39 3 to the third-stage interference estimating sections 31 13 through 31 33 . In addition, the second-stage interference estimating sections 31 12 through 31 32 subtract, from the extracted reception data demodulated data corresponding to the reception data 36 1 through 36 3 previously added and then multiply user data signals again by the spread codes assigned to the users, respectively. Thus, the signal components of the relevant users contained in the residual signal 38 are reproduced. These signal components are supplied as reproduction signals 40 1 through 40 3 to the residual signal producing section 32 2 . In addition to the reproduction signals 40 1 through 40 3 , the residual signal producing section 32 2 is supplied with the residual signal 38 and produces a residual signal 41 obtained by subtracting the reproduction signals 40 1 through 40 3 from the residual signal 38 . The residual signal 41 is used as an input signal to be subjected to interference removal in the third stage.
In the similar manner, the third-stage interference estimating sections 31 13 through 31 33 extract desired user signals for the residual signal 41 and produce demodulation signals 42 1 through 42 3 of the desired users corresponding to the reception data 36 1 through 36 3 and 39 1 through 39 3 produced by the first- and the second-stage interference estimating sections 31 11 through 31 31 and 31 12 through 31 32 , respectively. In this event, the residual signals 38 and 41 successively approach zero so that the third-stage interference estimating sections 31 13 through 31 33 produce the demodulation signals 42 1 through 42 3 from the added user signals after the interference is removed at maximum, respectively.
Now, description will be made about a characteristic part of the structure of the CDMA receiver in the first embodiment.
FIG. 3 shows the characteristic part of the first-stage interference estimating sections of the CDMA receiver in FIG. 2 according to the first embodiment. In FIG. 2, the first-stage interference estimating sections 31 11 through 31 31 are separately illustrated in correspondence to the reception timings detected for the individual users for which simultaneous demodulation is possible. On the other hand, these sections are integrated in FIG. 3 into a first-stage interference estimating section 44 1 . The first-stage interference estimating section 44 1 has demodulation processing units 45 1 through 45 3 and re-spreading units 46 1 through 46 3 for the reception timings, respectively, and comprises a RAKE combining unit 47 1 and a reproduction signal producing unit 48 1 in common to all of the reception timings. The demodulation processing units 45 1 through 45 3 are similar in structure to one another. The re-spreading units 46 1 through 46 3 are similar in structure to one another. Although three timings are herein illustrated, the number of timings is not restricted in principle as far as the constraint in mounting is eliminated. Hereinafter, the demodulation processing unit 45 1 and the re-spreading unit 46 1 will be described among these demodulation processing units and these re-spreading units.
The demodulation processing unit 45 1 comprises a demodulating portion 49 1 for demodulating an input signal, a reception timing producing portion 50 1 for producing a demodulation timing of the demodulating portion 49 1 , and an SIR information producing portion 51 1 for measuring an SIR of the input signal to produce SIR information. The demodulating portion 49 1 comprises a dispreading part 53 1 and a transmission-path estimating part 54 1 . The demodulation processing unit 45 1 is supplied with the multiplexed signal 33 . The dispreading part 53 1 of the demodulating portion 49 1 multiplies the multiplexed signal by the spread code of a predetermined user to extract a desired user signal. The transmission-path estimating part 54 1 calculates transmission-path characteristic information by the use of a pilot symbol known to be preliminarily contained in the reception signal and compensates despread data with reference to the transmission-path characteristic information. Such demodulation by the demodulation portion 49 1 is carried out in synchronism with the reception timing producing portion 50 1 . The reception timing producing portion 50 1 produces the reception timing obtained by preliminarily compensating the processing delay of the reception timing detecting section 30 or other internal propagation delays, and further corrects the reception timing with reference to the reception timing information 35 1 . For example, the reception timing produced as mentioned above preliminarily considering the delay is used as a base and corrected with reference to the reception timing information 35 1 . The SIR information producing portion 51 1 calculates a signal-to-interference ratio for a signal component which is the despread data despread by the demodulating portion 49 1 and for an interference component which is a remaining component of the reception signal other than the signal component, and produces SIR information representative of the ratio. The SIR information is supplied to the RAKE combining unit 47 1 and, in the first-stage interference estimating section 44 1 , further to the reception timing detecting section 30 .
The RAKE combining unit 47 1 is supplied with the despread data despread by the demodulating portion 49 1 and carries out maximum ratio synthesis with reference to the SIR information produced by the SIR information producing portion 51 1 for the individual reception timings. Specifically, weighted synthesis given by “SIR 1 ×S 1 +SIR 2 ×S 2 +SIR 3 ×S 3 ” is carried out where S 1 through S 3 and SIR 1 through SIR 3 represent the despread data and the SIR information of the individual users, respectively The synthesized output of the RAKE combining unit 47 1 is supplied to the re-spreading units 46 1 through 46 3 .
The re-spreading unit 46 1 comprises a spreading portion 55 1 . The synthesized output of the RAKE combining unit 47 1 supplied to the re-spreading unit 46 1 is directly outputted as the reception data 36 1 . The spreading portion 55 1 multiplies the synthesized output again by the spread code corresponding to each individual user to produce a spread signal. The spread signal is supplied as the reproduction signal 37 1 to the reproduction signal producing unit 48 1 . The reproduction signal producing unit 48 1 is supplied with the reproduction signals 37 1 through 37 3 produced for the individual reception timings and combines these signals to reproduce a signal with the individual timings taken into account, as is equivalent to the multiplexed signal 33 . The reproduction signal 37 herein reproduced is delivered to the residual signal producing section 32 1 . Actually, the residual signal producing section 32 1 produces the residual signal 38 by subtracting from the multiplexed signal 33 the reproduction signal 37 with the individual timings taken into account.
As described above, the first-stage interference estimating section 44 1 corrects the demodulation timing with reference to the reception timing information and produces the demodulated data and the reproduced data. The second- and the third-stage interference estimating sections 44 2 and 44 3 are similar in structure and different from the first-stage interference estimating section 44 1 in that the demodulated data of the preceding stage are supplied and correction of the demodulation timings is not carried out.
FIG. 4 shows the characteristic part of the second-stage interference estimating sections of the CDMA receiver in FIG. 2 according to the first embodiment. In FIG. 2, the second-stage interference estimating sections 31 12 through 31 32 are separately illustrated in correspondence to the reception timings detected for the individual users for which simultaneous demodulation is possible. On the other hand, these sections are integrated in FIG. 4 into a second-stage interference estimating section 44 2 . The second-stage interference estimating section 44 2 has demodulation processing units 56 1 through 56 3 and re-spreading units 57 1 through 57 3 for the reception timings, respectively, and comprises a RAKE combining unit 58 1 and a reproduction signal producing unit 59 1 in common to all of the reception timings. The demodulation processing units 56 1 through 56 3 are substantially similar in structure to one another. The re-spreading units 57 1 through 57 3 are similar in structure to one another. The demodulation processing unit 56 1 comprises a demodulating portion 60 1 for demodulating an input signal, an SIR information producing portion 61 1 for measuring an SIR of the input signal to produce SIR information, and an adder portion 62 1 . The demodulating portion 60 1 comprises a despreading part 63 1 and a transmission-path estimating part 64 1 . The demodulation processing unit 56 1 further comprises a reception timing producing portion 65 1 for producing a demodulation timing of the demodulating portion. Although three timings are herein illustrated, the number of timings is not restricted in principle as far as the constraint in mounting is eliminated. The second-stage interference estimating section 44 2 is substantially similar in structure to the first-stage interference estimating section 44 1 . Therefore, different parts alone will be described.
The demodulation processing unit 56 1 is supplied with the residual signal 38 and the reception timing produced by the reception timing producing portion 65 1 . Demodulation by the demodulating portion 60 1 is carried out in synchronism with the reception timing produced by the reception timing producing portion 65 1 . The reception timing producing portion 65 1 produces the reception timing obtained by preliminarily compensating the processing delay of the reception timing detecting section 30 and other internal propagation delays, and further corrects the reception timing with reference to the reception timing information 35 1 . For example, the reception timing produced preliminarily taking the delay into account is used as a base and corrected with reference to the reception timing information 35 1 . The demodulating portion 60 1 of the demodulating processing unit 56 1 carries out despreading in synchronism with the spread code preliminarily assigned to the user to extract a desired user signal. The despread data despread by the demodulating portion 60 1 are supplied to the adder portion 62 1 . The adder portion 62 1 is supplied from the first-stage interference estimating section 44 1 with the reception data 36 1 corresponding to the reception timing and adds the reception data 36 1 to the despread data. This increases the ratio of the signal component of each individual user contained in the weak residual signal 38 supplied to the second-stage interference estimating section 44 2 as the input signal to be subjected to interference removal, and enhances the accuracy of the demodulation signal. The result of addition in the adder portion 62 1 is supplied to the RAKE combining unit 58 1 .
The re-spreading unit 57 1 comprises a subtracter portion 66 1 and a spreading portion 67 1 . The re-spreading unit 57 1 directly outputs, as the reception data 39 1 the synthesized output obtained by maximum ratio synthesis in the RAKE combining unit 58 1 . Supplied with the synthesized output obtained by maximum ratio synthesis by the RAKE combining unit 58 1 and with a despread signal 68 1 obtained by despreading by the despreading part 63 1 in the demodulating portion 60 1 of the demodulation processing unit 56 1 . The subtracter portion 68 1 of the re-spreading unit 57 1 subtracts the despread signal 68 1 from the maximum synthesized ratio output. The result of subtraction is supplied to the spreading portion 67 1 . The spreading portion 67 1 multiplies the subtraction result by the spread code corresponding to each individual user to produce a spread signal The spread signal is supplied as the reproduction signal 40 1 to the reproduction signal producing unit 59 1 . The reproduction signal producing unit 59 1 is supplied with the reproduction signals 40 1 through 40 3 produced for the individual reception timings and combines these signals to reproduce a signal with the individual timings taken into account, as is equivalent to the residual signal 38 . The reproduction signal 40 herein reproduced is delivered to the residual signal producing section 32 2 . Actually, the residual signal producing section 32 2 produces the residual signal 41 by subtracting, from the residual signal 38 , the reproduction signal 40 with the individual reception timings taken into account.
Thus, the second-stage interference estimating section 44 2 corrects the reception data 36 1 through 36 3 from the first stage and delivers the corrected data to the third stage. A combination of the third-stage interference estimating sections 31 13 through 31 33 (FIG. 2) similarly operates to obtain the reception data 42 1 through 42 3 for the individual users.
Next, description will be made in detail about a characteristic part of the reception timing detecting section 30 of FIG. 2 .
FIG. 5 shows the characteristic part of the reception timing detecting section 30 of the CDMA receiver in the first embodiment. The reception timing detecting section 30 has correlation value calculating units 70 1 through 70 3 for the individual reception timings and comprises a spread code delay generating unit 71 , a spread code producing unit 72 , and a reception timing calculating unit 73 in common to all of the reception timings. Although the correlation value calculating units 70 1 through 70 3 are provided for the three timings, the number of timings is not restricted in principle as far as the constraint in mounting is eliminated. The reception timing calculating unit 73 comprises an SIR calculating portion 74 , a correlation value data averaging portion 75 , and a reception timing determining portion 76 . The spread code producing unit 72 produces the predetermined spread codes for the individual users. The spread code delay generating unit 71 multiplies the spread codes of the individual users produced by the spread code producing unit 72 by the pilot symbol PS as the predetermined (or fixed) pattern data. For each user, the length of the pilot symbol is extracted from the spread code having a predetermined pattern length and is used in multiplication. By shifting the position of extracting the spread code over the width of a predetermined sampling period within a range of a reception timing detectable period, predetermined signal reproduction signals 77 1 through 77 3 are obtained with the spread codes delayed. The correlation value calculating units 70 1 through 70 3 multiply the multiplexed signal 33 by the predetermined signal reproduction signals 77 1 through 77 3 supplied thereto, respectively, to calculate correlation data 78 1 through 78 3 as cross-correlation values therebetween within the reception timing detectable period. The correlation data 78 1 through 78 3 are cross-correlation values corresponding in number to sampling times. The correlation value data averaging portion 75 of the reception timing calculating unit 73 carries out averaging over a predetermined time duration for each sampling and produces a correlation value table.
FIG. 6 shows a table structure of the correlation value table 79 produced by the correlation value data averaging portion 75 . The correlation value table 79 stores sampling times 80 and correlation value levels 81 corresponding thereto. As described above, the correlation value data averaging portion 75 carries out averaging upon the correlation data 78 1 through 78 3 produced by the correlation value calculating units 70 1 through 70 3 over the predetermined time duration for each sampling. For example, it is assumed that N times of sampling is possible within the reception timing detectable period. Then, correlation data average values LV 0 through LV N taken over the predetermined time duration for the sampling times T 1 through T N , respectively, are stored in the correlation value table 79 in correspondence to the sampling times.
Turning to FIG. 5, description will continue. Since the SIR information 34 1 through 34 3 supplied from the first-stage interference estimating section 44 1 correspond in number to the reception timings, the SIR calculating portion 74 calculates, by linear interpolation and averaging, the SIR information at the sampling times within the predetermined time range between time instants before and after the reception timing. The SIR information thus calculated is stored in an SIR information table.
FIG. 7 shows a table structure of the SIR information table 82 produced by the SIR calculating portion 74 . For each sampling time 83 at which the above-mentioned interpolation is carried out, the SIR information table 82 stores the SIR information 84 as interpolated values corresponding thereto. It is assumed that the reception timing is located at a position T m on a time axis.
Then, for a plurality of interpolation sampling times within the time range between “T m −t n ” and “T m +t n ” before and after the reception timing, the SIR information is calculated by linear interpolation and averaging from the SIR information 34 1 through 34 3 corresponding in number to the reception timings and stored as SIR 0 through SIR M .
The reception timing determining portion 76 of the reception timing calculating unit 73 determines the reception timing for demodulation with reference to the information stored in the correlation value table produced by the correlation value data averaging portion 75 and the SIR information table produced by the SIR calculating portion 74 .
FIG. 8 shows the content of reception timing determination at the reception timing determining portion 76 . At first, the reception timing determining portion 76 refers to the correlation value table 79 illustrated in FIG. 6 and retrieves a particular sampling time having a maximum correlation value level (step S 85 ). Then, judgement is made about whether or not the maximum correlation value level is not smaller than a predetermined first threshold value (step S 86 ). If it is judged that the maximum correlation value level is not smaller than the first threshold value (Y in step S 86 ), the SIR information table 82 illustrated in FIG. 7 is searched from the sampling time corresponding to the maximum correlation value level to retrieve the interpolated sampling time corresponding thereto. Since the reception timing is preliminarily known upon preparation of the SIR information table, it is easy to establish the correspondence between the interpolated sampling time 83 of the SIR information within the predetermined range and the sampling time 80 in FIG. 6 . Therefore, the interpolated sampling time 83 corresponding to the sampling time is identified and the SIR information stored in correspondence to the interpolated sampling time can be retrieved (S 87 ). If it is judged in the step S 86 that the first threshed value is not exceeded (N in step S 86 ), the operation returns to the step S 85 to retrieve the next reception timing.
Next, judgement is made about whether or not the SIR information retrieved in the step S 87 is not smaller than a predetermined second threshold value (step S 88 ). If it is judged that the SIR information is not smaller than the second threshold value (Y in step S 88 ), the timing in question is determined as the reception timing (step S 89 ). If it is judged in the step S 88 that the second threshold value is not exceeded (N in the step S 88 ), the operation returns to the step S 85 to retrieve the next reception timing. Finally, judgement is made about completion of retrieval, i.e., whether or not the reception timings of a required number have been determined or whether or not the correlation value table has been completely retrieved. If no further retrieval is required (Y in step S 90 ), a series of operations are finished (END). On the other hand, if any further retrieval is required, the operation returns to the step S 85 to retrieve the next reception timing.
As described above, in the CDMA receiver according to the first embodiment, the SIR information table including interpolation before and after the reception timing is prepared by the use of the SIR information measured by the first-stage interference estimating section 44 1 for each individual user. Furthermore, for the reception signal, the correlation value table is provided to store the correlation value with the pilot symbol to be used as the reception timing in correspondence to each sampling time within a range of the reception timing detectable period. Thus, correction into an optimum reception timing is made. Therefore, even in case where the multistage interference removal of a multi-user type is carried out, it is possible to eliminate the influence of the interference component from the reception timing and to carry out interference removal with reference to the accurate reception timing.
Second Embodiment
The CDMA receiver according to the first embodiment is applied to the multistage interference removal but this invention is not restricted thereto. In a second embodiment, illustration is made of a CDMA receiver which is not applied to the multistage interference removal.
FIG. 9 shows a characteristic part of a reception timing detecting section of the CDMA receiver according to the second embodiment of this invention. Similar parts are designated by like reference numerals as those of the reception timing detecting section 30 in FIG. 2 according to the first embodiment and the description thereof will appropriately be omitted. The reception timing detecting section 100 in the second embodiment has correlation value calculating units 70 1 through 70 3 for individual reception timings and comprises a spread code delay generating unit 71 , a spread code producing unit 72 , and a reception timing calculating unit 101 in common to all of the reception timings. The reception timing calculating unit 101 comprises an SIR calculating portion 102 , a correlation value data averaging portion 75 , and a reception timing determining portion 76 . The spread code producing unit 72 produces the predetermined spread codes for the individual users. The spread code delay generating unit 71 multiplies the spread codes of the individual users produced by the spread code producing unit 72 by the pilot symbol PS as the predetermined pattern data. For each user, the length of the pilot symbol is extracted from the spread code having a predetermined pattern length and is used in multiplication. By shifting the position of extracting the spread code over the width of a predetermined sampling period within a range of a reception timing detectable period, predetermined signal reproduction signals 77 1 through 77 3 are obtained with the spread codes delayed. The correlation value calculating units 70 1 through 70 3 multiply the multiplexed signal 33 by the predetermined signal reproduction signals 77 1 through 77 3 supplied thereto, respectively, to calculate correlation data 78 1 through 78 3 as cross-correlation values therebetween within the reception timing detectable period. The correlation data 78 1 through 78 3 are cross-correlation values corresponding in number to sampling times. The correlation value data averaging portion 75 of the reception timing calculating unit 73 carries out averaging over a predetermined time duration for each sampling and produces a correlation value table illustrated in FIG. 6 .
The SIR calculating portion 102 calculates SIRs at all sampling points from the multiplexed signal 33 and the correlation value data 78 1 through 78 3 corresponding in number to the reception timings. The SIRs are subjected to linear interpolation and averaging for a predetermined period to calculate the SIR information at sampling times in a predetermined time range before and after the reception timing. The SIR information thus calculated is stored in a SIR information table illustrated in FIG. 7, in the manner similar to the first embodiment.
The reception timing determining portion 76 of the reception timing calculating unit 101 determines the reception timing for demodulation with reference to the information stored in the correlation value table produced by the correlation value data averaging portion 75 and the SIR information table produced by the SIR calculating portion 102 . The operation is similar to that illustrated in FIG. 8 and will not be described. For example, the reception timing thus determined may be outputted as the reception timing information for making the reception timing producing section produce the accurate reception timing as described in the first embodiment or may be delivered directly as the reception timing to a demodulator not illustrated in the figure. Thus, the mode of output is not restricted.
In the CDMA receiver of the second embodiment, the reception timing detecting section produces the SIR information table from the multiplexed signal and the correlation value data. Therefore, it is unnecessary for the first-stage interference estimating section to refer to the SIR information as in the first embodiment. This contributes to a reduction in size of the receiver. The above-mentioned reception timing detecting section can notify the accurate reception timing not only to the CDMA receiver using the above-mentioned multistage interference removal but also to other types of receivers.
In the first embodiment, description has been directed to application to the multistage interference removing technique of repeating the interference removal for three users in three stages. However, the number of users and the number of stages are not restricted at all.
As described above, according to this invention, the demodulation timing of the reception multiplexed signal is corrected with reference to the correlation value detected as the reception timing and the SIR in the actual demodulation signal. Therefore, even if the SIR is low, the optimum reception timing can be detected so that the reception quality is improved. In addition, it is possible to lower the SIR required to obtain a predetermined reception quality. Therefore, the transmission power of a mobile terminal in a CDMA mobile communication system can be lowered. This contributes to a reduction in size of the terminal and to low the power consumption. Since the transmission power at each user is lowered, it is possible to increase the number of users for which multiplexing in a same frequency is possible. | In a CDMA receiver which receives, as a reception signal ( 33 ), a signal given by subjecting a data signal comprising predetermined pattern data (PS) to spread modulation by the use of a spread code, a correlation value calculating unit ( 70 1 -70 3 ) produces correlation value data obtained by multiplying the reception signal by the spread code and the predetermined pattern data. A signal-to-interference ratio calculating portion ( 74 ) calculates a signal-to-interference ratio of the reception signal. A reception timing determining portion ( 76 ) determines a reception timing of the predetermined pattern data in response to the correlation value data and the signal-to-interference ratio. Preferably, the reception timing determining portion determines the reception timing such that the maximum value of said correlation value data exceeds a predetermined first threshold value and that said signal-to-interference ratio exceeds a predetermined second threshold value when said correlation value data have the maximum value. | 7 |
BACKGROUND
[0001] This invention concerns a foldable modular structure for a fast-erecting tent or similar shelter.
[0002] The invention relates particularly to tents designed for emergency situations and military use. In this particular type of application, it is required that tents have a relatively small volume when they are disassembled, and that they can be erected and deployed quickly whilst providing shelter capable of resisting harsh weather conditions.
[0003] Generally a tent consists of a structure supporting a canvas, said structure being dismountable, and consisting to this effect of a frame assembled by slotting together tubular sections, which may be articulated with each other.
[0004] Structures are already known that comprise a succession of parallel roof poles forming trusses, linked two by two by connecting bars notably constituting purlins. These connecting bars are slotted together with said roof poles, and to enable the roof poles to be moved closer together and/or apart, these bars be formed of two profiled section members articulated with each other and lockable lengthwise to form a rigid bar or purlin.
[0005] With EP1493886 in particular, a rapidly erectable, modular and foldable structure for tents is known, which consists of an assembly of tubular sections, enabling in particular at least two opposing arches to be formed, linked by at least two purlins, including one ridge purlin. Said ridge purlin in this case consists of the abutment of two profiled sections, each fastened, moreover, at the other end to a ridge part on each of said arches, said end comprising, firstly, pivoting means enabling it to pivot on said ridge part around an axis perpendicular to the plane of the arch, whilst indexing means angularly limit said pivoting and, secondly, pivoting means enable the rotation of said end around a transverse axis parallel to the plane of the arch, in order to enable said profiled section to fold parallel to said arch. The abutment of the two profiled sections of the ridge purlin is achieved by interlocking means capable of immobilising the axial rotation of one section in relation to the other according to the angular positions of the latter defined by said indexing means.
[0006] Due to the limiting of the rotation around an axis perpendicular to the plane of the arches, of each of the sections in relation to the respective arches with which they are linked, and due to the immobilising of the pivoting in relation of the two sections when erecting the structure, such a structure makes it possible to maintain the ridge purlin formed by the assembly of the two sections in a fixed position.
[0007] This system is satisfactory, although it requires relatively precise indexing means to ensure good immobilisation of the pivoting of the ridge purlin without interfering with the abutting operations when erecting the structure.
SUMMARY
[0008] The purpose of this invention is to solve the problems mentioned above, and it aims in particular to propose a foldable modular structure that is simpler and more robust in design than earlier systems.
[0009] With these aims in mind, the invention concerns a foldable modular structure for a fast-erecting tent or similar shelter, consisting of the assembly of profiled sections, generally of the tubular type, intended to support a canvas, said profiled sections forming, in particular, at least two opposing arches linked by at least two purlins, including one ridge purlin.
[0010] According to the invention, the structure is characterised in that a first end of said ridge purlin is linked by a hinge to a first ridge part on a first of said arches, said hinge comprising, on the one hand, first pivoting means allowing said ridge purlin to pivot according to a transverse axis, parallel to the plane of the arch, in order to allow the purlin to fold parallel to said arch, and on the other hand, second pivoting means allowing the ridge purlin to pivot according to an axis perpendicular to the plane of the arch, and the second end of the ridge purlin comprises linking means for linking with a second ridge part on the second of said arches, said linking means being arranged to provide a dismountable but rigid link between the ridge purlin and said second linking part.
[0011] By a dismountable but rigid link, it is understood here a link immobilising the ridge purlin on the second linking part when the structure is erected and in use, but separable during the disassembly operations during routine use of the structure, that is to say when the tent is dismantled, and that with no need for any tools.
[0012] Thus, when the structure is folded away for transport, the ridge purlin can, thanks to the dual-pivoting joint means at its first end which form a sort of swivel joint, be folded against a profiled section forming the first arch. And, when the structure is deployed, the dismountable rigid link of the second end of the ridge purlin to the second arch is capable of immobilising the ridge purlin pivoting with respect to the arches, according to a longitudinal axis of said ridge purlin. Thereby the distance between the arches is maintained, whilst the dismountable rigid link also guarantees the optimum positioning of the ridge purlin to provide the best mechanical flexural strength under the loads to which it is subjected when the tent is in use.
[0013] Typically, the ridge purlin has a generally elongated rectangular cross section, and the ridge purlin will therefore be immobilised in rotation in a position where its cross section extends vertically, offering the best mechanical resistance to vertical loads.
[0014] According to a preferred embodiment, the ridge purlin is telescopic, making it possible to reduce its length in order to place it, when in the retracted position, against one of the rafters constituting the arch, without exceeding the length of that rafter. It will be noted incidentally that, to make the structure more compact when it is folded away, whilst still allowing for large dimensions when it is deployed, said rafters may also be telescopic. When the structure is deployed, the ridge purlin is extended so that its length corresponds to the distance between the arches, which is, moreover, determined by the length of the other purlins, as will be seen below.
[0015] So that the ridge purlin is telescopic as indicated above, it comprises, preferentially, two tubular sections sliding one inside the other, and locking means are provided to lock said sliding sections one onto the other. These locking means may typically be pin-type locking devices, according to a principle that is well known elsewhere, resiliently mounted to be retractable into the inner section and able to engage, when the telescopic purlin is extended, in a hole in the outer section, thereby locking the two sections in position.
[0016] According to another particular embodiment, the hinge connecting the ridge purlin to the first ridge part comprises a clevis, integral with the end of the ridge purlin, pivotably mounted on an intermediate swivel pin according to an axis parallel to the plane of the arch, the intermediate swivel pin being pivotably mounted on the first ridge part according to an axis perpendicular to the plane of the arch. This embodiment achieves the two pivoting movements required of the ridge purlin in relation to the first arch in a simple way.
[0017] According to another particular embodiment, the linking means linking the ridge purlin to the second ridge part comprise a fixed bush linked rigidly to the second ridge part and having a vertical axis, and a lug, integral with the second end of the ridge purlin, extending perpendicular to the longitudinal direction of the ridge purlin and in the longitudinal direction of the cross section of the latter, and arranged to engage slidingly downwards into said bush.
[0018] When the structure is deployed, this lug is simply inserted into said bush to achieve at once the linking of the two arches and the immobilization of the pivoting of the ridge purlin around its own longitudinal axis. The weight of the ridge purlin and the tent canvas supported by the latter is sufficient to hold the lug in place in the bush.
[0019] According to yet another particular embodiment, each of the arches consists of a ridge part and two rafters, preferentially telescopic, attached to said ridge part according to separated axes perpendicular to the plane of the arch, the pivoting of the rafters being limited by stops provided in said ridge part. These embodiments allow the rafters to be folded one against the other when folding away the structure, thereby ensuring the compactness of the folded structure.
[0020] Also preferentially, the ridge parts comprise means of centering them one with the other in order to maintain them in their relative position when the structure is folded away, which maintains the ridge parts and the rafters in their relative positions as long as the structure is not deployed.
[0021] The secondary purlin or purlins that link the two arches together in addition to the ridge purlin, preferentially consist of two profiled sections pivotably attached on one hand to each other and also to their respective arches, according to parallel axes of rotation, so as to allow one of said sections to be folded onto the other, thereby bringing together two neighbouring arches. The axes of rotation of the profiled sections are perpendicular to the general direction of the rafters forming the arches, so that said sections can be folded against the rafters and parallel to them.
[0022] The joint linking the two profiled sections forming a purlin comprises blocking means allowing the two sections to kept aligned after deployment, said blocking means comprising, preferentially, a tubular latch arranged to slide over said sections and to be able to cover the joint and the ends of the two sections adjacent to said joint, thereby immobilising said sections in aligned respective position.
[0023] Other features and advantages will appear in the description that follows of a foldable modular structure for a fast-erecting tent according to the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Referring to the drawings enclosed:
[0025] FIG. 1 is a perspective view of the structure according to the invention, in the transport position, prior to any deployment,
[0026] FIG. 2 shows the first phase of erection, with the deployment of the rafters forming the arches,
[0027] FIG. 3 shows the next stage of erection, with the deployment of the eave purlins,
[0028] FIGS. 4 and 5 show in detail the hinge of the profiled sections constituting said eave purlins, in the folded and deployed positions respectively,
[0029] FIG. 6 shows the structure after complete deployment of the eave purlins, before deploying the ridge purlin,
[0030] FIG. 7 shows in detail the link between the ridge purlin and the first ridge part,
[0031] FIG. 8 is a view of the first ridge part on its own,
[0032] FIG. 9 is a view of the second ridge part on its own,
[0033] FIG. 10 illustrates the beginning of the deployment of the ridge purlin,
[0034] FIGS. 11 and 12 illustrate the connection of the ridge purlin onto the second arch,
[0035] FIG. 13 shows the structure after complete deployment of the eave purlins and the ridge purlin,
[0036] FIG. 14 shows the complete structure, with its legs, ready to receive the tent canvas.
DETAILED DESCRIPTION
[0037] The structure according to the invention illustrated in the different drawings comprises three arches: two end arches 1 and a central arch 2 , each in the shape of an inverted V and consisting of a ridge part 10 , 20 , onto which are attached, pivoting according to axes of rotation A perpendicular to the plane of the arch, two rafters, 11 and 12 , and 21 and 22 , respectively. The pivoting of the rafters on the ridge parts is limited by stops 101 , 201 provided on said ridge parts so as to achieve the desired angle of the V formed by the rafters.
[0038] Each rafter comprises at its opposite end to the ridge part, an angle part 13 , 23 arranged to connect firstly the legs 3 , and secondly, the eave purlins.
[0039] Arches 1 and 2 are connected by three purlins, one ridge purlin 4 which extends between the two ridge parts 10 , 20 of the neighbouring arches 1 , 2 , and two eave purlins 5 which are also connected pivotably with the angle parts 13 , 23 .
[0040] The eave purlins 5 consist of two profiled sections 51 , 52 pivotably attached, on the one hand, to each other, and on the other hand to their respective arches 1 , 2 , according to parallel axes of rotation A 1 to A 4 , as can be seen in FIG. 3 , so as to allow said sections 51 , 52 to be folded one over the other and therefore two neighbouring arches to be moved closer together or apart. The profiled sections 51 , 52 are attached to each other by means of a linking part 53 , which can be seen better in FIGS. 4 and 5 . This linking part 53 , onto which the profiled sections 51 , 52 are pivotably mounted according to axes A 2 , A 3 , parallel to and distant from each other so as to allow the sections to be folded parallel one against the other, also comprises two stops 531 arranged to limit the relative pivoting of the sections in the direction of moving them apart, at a position in which the two sections are in alignment, as shown in FIG. 5 . A latch 54 , in the form of a tubular member slidingly mounted with a simple functional clearance onto one of the sections, can then be slid into a position where it covers the articulation area including the ends of the two sections 51 , 52 and the linking part 53 , and can be immobilised in translation, thereby blocking the two sections in an aligned position, as can be seen in FIG. 6 in particular.
[0041] It will also be noted that the axes of rotation A 1 and A 4 of the two profiled sections on the angle parts 13 , 23 are orthogonal to the rafters 11 , 12 , 21 , 22 , so that, in the folded position, the sections are folded against said rafters, parallel to them, as shown in FIGS. 1 and 2 .
[0042] The ridge purlin 4 consists of two profiled sections 41 , 42 of generally rectangular cross section, sliding one inside the other so that the ridge purlin is telescopic; and it comprises means of locking the two sections 41 , 42 both in the retracted position, to hold the ridge purlin in this retracted position when the structure is folded away, and in the extended position, when the purlin is connecting the two arches 1 , 2 . These locking means may in particular be pin-type locking devices 43 , of a type already known for locking sliding telescopic members.
[0043] The ridge purlin 4 is fastened at one end onto a first arch, for example arch 1 , by means of a concurrent axis hinge system 6 allowing first of all the ridge purlin 4 to pivot in relation to the arch 1 according to an axis A 5 parallel to the plane of said arch, and according to an axis A 6 orthogonal to said plane of the arch, which allows the ridge purlin to be brought against one of the rafters 11 , 12 when the structure is folded away, and, alternatively, when the structure is deployed, to place said purlin 4 perpendicular to the plane of the arch 1 , to connect the second arch 2 to it, the pivoting according to axis A 6 allowing the ridge purlin 4 to be placed in the position where it offers the best resistance to the vertical loads, that is to say with its rectangular cross section, and therefore axis A 5 , oriented vertically. The hinge system 6 typically comprises a swivel pin 61 pivotably mounted according to axis A 6 on the ridge part 10 , and the end of the ridge purlin 4 comprises a clevis 44 pivotably mounted on said swivel pin according to axis A 5 .
[0044] The ridge purlin 4 comprises at its other end a connecting piece 45 comprising a lug 46 which extends perpendicular to the ridge purlin and is oriented according to the largest direction of the cross section of said purlin, that is to say parallel to axis A 5 . The lug is also dimensioned to engage by sliding vertically, as shown in FIG. 11 , into a bush 25 rigidly linked to the ridge part 20 and whose axis A 7 is vertical when the structure is erected. The fixed bush 25 may be made of one piece with the ridge part 20 . Thus when the lug 46 is slotted into the bush 25 , on the one hand the ridge purlin rigidly connects the two ridge parts 10 , 20 , and on the other hand said slotting together prevents the ridge purlin from pivoting according to its longitudinal axis, thereby maintaining it in the optimum position for the strength of the structure.
[0045] In addition, the fixed bush 25 has a centering stud 251 , extending orthogonally to axis A 7 and in the general plane of the ridge part 20 and with dimensions that allow it to engage in a hole 611 provided to this effect in the swivel pin 61 , when the structure is folded away, the ridge parts 10 and 20 being positioned one against the other, as shown in FIG. 1 . Thus, during the first stage of unfolding the structure, illustrated by FIG. 2 , the different ridge parts remain positioned in alignment, avoiding them moving over each other, which could otherwise cause the different components of the structure to move respectively in an uncontrolled way. Thanks to this system of centering the different ridge parts, the deployment and erection of the structure is notably facilitated. In a quite equivalent way, the centering stud could be formed on the swivel pin 61 , cooperating with a hole provided in the fixed bush.
[0046] The structure is erected as follows: starting from the folded position of the structure shown in FIG. 1 , we begin by deploying the rafters 11 , 12 , 21 , 22 by pivoting them on the ridge parts 10 , 20 , in the directions F 1 , until the rafters are brought up against the stops 101 , 201 , in the position shown in FIG. 2 , the ridge parts then being held in place in relation to each other by the studs 251 engaged in the holes 611 .
[0047] We continue to deploy the structure by opening the arches 1 , 2 , as shown by the arrows F 2 in FIG. 3 . This opening movement is accompanied by the pivoting, in directions F 3 , of the profiled sections 51 , 52 constituting the eave purlins 5 , until said sections are in alignment, this alignment being achieved furthermore by said sections coming up against the stops 531 in the linking parts 53 . The latches 54 are then slid in direction F 4 until the profiled sections 51 , 52 are held together in said aligned position.
[0048] The ridge purlin 4 , which until now was still in its position up against a rafter, is deployed by pivoting it around axis A 5 , in direction F 5 , and by pivoting it on itself around axis A 6 in direction F 6 , to bring the ridge purlin perpendicular to the plane of arch 1 , its cross section extending vertically. The ridge purlin is extended by relatively sliding the profiled sections 41 , 42 that constitute it, in direction F 7 , until these sections are locked into the extended position of the ridge purlin, whose second end is then connected to the ridge part 20 of the second arch by engaging the lug 46 in the bush 25 .
[0049] The structure in now in the state illustrated in FIG. 13 . If the rafters are also telescopic, then we now bring them into their extended position, then we connect the legs 3 onto the angle parts 13 and 23 to complete the erection of the structure, which is now ready to receive the tent canvas.
[0050] Folding the structure away, of course takes place by carrying out the operations in reverse order.
[0051] The structure in the example that has just been described has three arches, but of course the same system can be used for structures with two arches or with more than three arches.
[0052] Intermediate secondary purlins could also be used to reinforce the support provided for the canvas, located between the ridge purlin and the eave purlins.
[0053] In similar structures, it is also possible to make the purlins other than the ridge purlin, or at least some of the other purlins, in a similar way to what has been described for the ridge purlin.
[0054] The rafters 11 , 12 , 21 , 22 , can also be telescopic, to increase the width of the structure, whilst still having a folded structure with a small volume. In this case, it will also be possible to use as means of locking for the rafters in the deployed position, and in the retracted position, pin-type locking devices similar to the locking device 43 used on the ridge purlin, or other locking devices of known types used to lock sliding telescopic members in position.
[0055] Although preferentially the profiled sections used have a rectangular cross section, which is generally optimal for reasons of mechanical strength, it is also possible to use sections with a different cross section, as long as, for the telescopic members at least, they are able to slide one inside the other without any relative rotation according to their longitudinal axis. | A foldable modular structure for a fast-erecting shelter comprising the assembly of profiled sections that form at least two opposing arches linked by at least two purlins, including one ridge purlin. A first end of the ridge purlin is linked by a hinge to a first ridge part of a first arch, said hinge comprising first pivoting means allowing said ridge purlin to pivot on a transverse axis, parallel to the plane of the arch, in order to allow the purlin to fold parallel to said arch, and second pivoting means allowing the ridge purlin to pivot on an axis perpendicular to the plane of the arch, and the second end of the ridge purlin comprises linking means for linking with a second ridge part of a second arch, said linking means being arranged to provide a dismountable but rigid link between the ridge purlin and said second linking part. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of and claims priority to U.S. patent application Ser. No. 12/981,758, filed Dec. 30, 2010, which is a continuation of International Application No. PCT/US2008/068781, filed Jun. 30, 2008, which is incorporated by reference in its entirety herein, and from which priority is claimed.
FIELD OF THE INVENTION
[0002] The present invention relates to compounds useful as fragrance or flavor components in fragrance or flavor compositions.
BACKGROUND OF THE INVENTION
[0003] The fragrance industry is constantly reliant on the development of new chemicals with favorable organoleptic properties to provide perfumers and other persons the capability of creating new, unique fragrances for applications such as personal care products, air care products, perfumes, colognes and the like.
[0004] 3-methoxy-3-methyl-1-butanol, also known as Solfit™, is known in the perfume industry and has been applied in many consumer products (WO 9512379; JP 2001226246; JP 2005290236; JP 001104462). The structure of 3-methoxy-3-methyl-1-butanol is shown below:
[0000]
[0005] Some esters derived from this alcohol have been employed as solvents for consumer products (EP 462605A2). Ether analogues of this alcohol have been used as intermediates to useful homoallylic alcohol entities (U.S. Pat. No. 4,990,697).
SUMMARY OF THE INVENTION
[0006] The present invention is directed to the synthesis and application of 3-methoxy-3-methyl-1-butanol derivatives having unique and desired odor or organoleptic characteristics. The compounds of the present invention can be employed alone or incorporated as perfumery ingredients to enhance already existing fragrance compositions, solvents, media and the like.
[0007] In one embodiment, the present invention provides fragrance compounds of the formula (I),
[0000]
[0000] wherein R 1 is an unsubstituted or substituted C 1-6 straight chain alkyl, an unsubstituted or substituted C 3-6 branched chain alkyl, an unsubstituted or substituted C 3-6 straight chain alkenyl, an unsubstituted or substituted C 3-6 branched chain alkenyl, an unsubstituted or substituted C 3-6 cycloalkyl, an unsubstituted or substituted C 1-6 alkoxy, nitrile, halo, an unsubstituted or substituted phenyl, an unsubstituted or substituted benzyl, an unsubstituted or substituted naphthyl, an unsubstituted or substituted aryl, an unsubstituted or substituted piperazino, an unsubstituted or substituted morpholinyl, amino, an unsubstituted or substituted C 1-6 alkylamino, an unsubstituted or substituted C 6-12 arylamino, an unsubstituted or substituted C 1-6 dialkylamino, an unsubstituted or substituted C 6-12 diarylamino, carboxy-C 1-6 alkylamino, carboxy-C 1-6 dialkylamino, an unsubstituted or substituted acetoxy, carboxy, an unsubstituted or substituted carboxyethyl, an unsubstituted or substituted C 1-6 alkylcarbonyl, thio, an unsubstituted or substituted C 1-6 alkylthio, an unsubstituted or substituted C 1-6 alkyloxy, carboxamido, an unsubstituted or substituted C 1-6 alkylcarboxamido, an unsubstituted or substituted C 1-6 dialkylcarboxamido, an unsubstituted or substituted phenoxy, an unsubstituted or substituted benzyloxy, phenylcarbonyl, benzylcarbonyl, an unsubstituted or substituted nitrophenyl, C 1-6 trialkylsilyl or nitro, an unsubstituted or substituted C 1-12 straight chain alkyl sulfonate, an unsubstituted or substituted C 1-12 branched chain alkyl sulfonate, an unsubstituted or substituted C 1-12 straight chain alkenyl sulfonate, an unsubstituted or substituted C 1-12 branched chain alkenyl sulfonate, an unsubstituted or substituted C 1-12 straight chain aryl sulfonate or an unsubstituted or substituted C 1-12 branched chain aryl sulfonate.
[0008] In a preferred embodiment, R 1 as shown in formula I above, is an unsubstituted or substituted C 1-6 straight chain alkyl, an unsubstituted or substituted C 3-6 branched chain alkyl, an unsubstituted or substituted C 3-6 straight chain alkenyl, an unsubstituted or substituted C 3-6 branched chain alkenyl, an unsubstituted or substituted C 3-6 cycloalkyl, an unsubstituted or substituted C 1-6 alkoxy, nitrile, halo, amino, an unsubstituted or substituted C 1-6 alkylamino, an unsubstituted or substituted C 1-6 dialkylamino, carboxy-C 1-6 alkylamino, carboxy-C 1-6 dialkylamino, an unsubstituted or substituted acetoxy, carboxy, an unsubstituted or substituted carboxyethyl, an unsubstituted or substituted C 1-6 alkylcarbonyl, an unsubstituted or substituted C 1-6 alkylcarboxy, an unsubstituted or substituted C 1-6 alkylthio, an unsubstituted or substituted C 1-6 alkyloxy, carboxamido, an unsubstituted or substituted C 1-6 alkylcarboxamido or an unsubstituted or substituted C 1-6 dialkylcarboxamido.
[0009] In a more preferred embodiment, R 1 is a C 1-6 straight chain alkyl, C 3-6 branched chain alkyl, an unsubstituted or substituted C 1-6 alkenyl, an unsubstituted or substituted C 1-6 acyl, or aryl.
[0010] In another embodiment, the invention provides fragrance compounds of the formula (II),
[0000]
[0000] wherein R 2 is the same as described for R 1 above in paragraph 6. In an alternative embodiment, R 2 is as R 1 is described above in paragraphs 7 or 8. Additionally, R 2 may be hydrogen. Usually, the alkyl 3-methoxy-3-methyl-1-butanol esters represented by formula II have a strong fruity note associated with them.
[0011] In another embodiment, the invention provides fragrance compounds of the formula (III),
[0000]
[0000] wherein R 3 is the same as described for R 2 above. Generally, the carbonate compounds represented by formula III have weak, varying odor characteristics but maintain a light and soft quality.
[0012] In another embodiment, the invention provides fragrance compounds of the formula (IV),
[0000]
[0000] wherein R 4 is the same as described for R 2 above. For example, when the alcohol, 3-methoxy-3-methyl-1-butanol, is reacted with an alkoxy acetic acid, a compound of formula (IV) will result from the condensation reaction. Glycolates represented by formula IV generally have a consistent light, powdery musk property.
[0013] In another embodiment, the invention provides fragrance compounds of the formula (V),
[0000]
[0000] wherein R 5 is the same as described for R 2 above. Compounds encompassed by formula (V) often possess variations of plastic and green olfactory notes.
[0014] In another embodiment, the invention provides fragrance compounds of the formula (VI),
[0000]
[0000] wherein R 6 and/or R 7 is a hydrogen or an unsubstituted or substituted C 1-6 straight chain alkyl, an unsubstituted or substituted C 3-6 branched chain alkyl group and n=0-1. Preferably, R 6 and/or R 7 are hydrogen or a methyl group.
[0015] Preferred fragrance compounds are set forth in the table below, in which R n refers to the R group of the respective formula.
[0000]
TABLE 1
Compound
For-
No.
mula
R n
Olfactory Description
1
I
—CH 2 CH(OCH 3 ) 2
weak, marine-like, clean
2
I
—CH 2 CH═CH 2
citrus, herbal, pine, sweet
orange, candy
3
I
—CH 2 C(CH 3 )═CH 2
citrus, green, lemon, slight
orange
4
I
—CH 2 CH═C(CH 3 ) 2
green, chocolate, sweet,
bitter
5
I
—CH(CH 3 )CH═CH 2
strong, mint, citrus, rose
6
I
—CH 2 CH 2 CH 3
woody, floral, slightly
bitter banana
7
I
—CH 2 CH(CH 3 ) 2
woody, green pear, slight
chocolate
8
I
—CH 2 CH 2 CH(CH 3 ) 2
chocolate, liqueur, sour,
slightly pungent
9
I
—CH 2 CH 2 C(OCH 3 )(CH 3 ) 2
mold, mildew
10
II
—H
woody, camphoraceous,
dry, chemical
11
II
—CH 2 CH 3
fruity, banana, floral,
bubble gum
12
II
—CH(CH 3 ) 2
fruity, green, pear, apple,
sour
13
II
—C(CH 3 )═CHCH 3
sugary, sweet sap, green
14
III
—CH 3
weak, light, green, floral
15
III
—CH 2 CH═CH 2
weak, soft chocolate, airy
16
III
—CH 2 CH 2 CH 3
weak, soft musk, light
vanilla
17
IV
—CH 3
weak, fruity, slight
coconut, powder musk
18
IV
—CH 2 CH 3
powder musk, fresh, soft,
light, clean
19
IV
—CH(CH 3 ) 2
very weak, powder musk
20
V
—CH 3
metallic green, plastic
21
V
—CH 2 CH 3
vegetable green, spicy,
plastic
22
V
—CH(CH 3 ) 2
green, licorice, slightly
mint, fresh
23
VI
—H (R 6 ) (n = 0)
fresh, melon, clean, floral,
muguet, green
24
VI
—CH 3 (R 6 ) (n = 0)
fresh, watery melon, clean,
floral, muguet
25
VI
—H (R 6 ), —H (R 7 ) (n = 1)
waxy, oily, muguet, light
floral
26
VI
—CH 3 (R 6 ) —H (R 7 )
waxy, oily, fatty
(n = 1)
[0016] In one embodiment the fragrance compound is selected from 3-methoxy-3-methylbutyl 2-ethoxyacetate, 2-(3-methoxy-3-methylbutoxy)ethanal, 1-methoxy-1,1-dimethyl-3-(3-methylbut-2-enyloxy)propane, 1-methoxy-1,1-dimethyl-3-prop-2-enyloxypropane, and 1-methoxy-1,1-dimethyl-3-(1-methylprop-2-enyloxy)propane.
[0017] In one aspect, the present invention provides a method to modify, enhance or improve olfactory and/or organoleptic property (e.g odor or flavor property) of a fragrance or flavor composition by adding to said composition an olfactory or organoleptic effective quantity of the compound of formulas (I-VI). In one embodiment, a fragrance compound is added to a fragrance carrier, fragrance base or both to provide a fragrance composition. In an alternative embodiment, a flavor compound is added to a flavor carrier to provide a flavor composition. It is understood here also that the invention may be described as the use of any composition containing formulas (I-VI) in fragrance and/or flavor compositions.
DETAILED DESCRIPTION OF THE INVENTION
Fragrance Compositions
[0018] The present invention is directed to the use of the above compounds as fragrances in a fragrance composition. The compounds can be incorporated alone, as a mixture of two or more of said compounds, or as an enhancer to an existing fragrance composition (discussed below). These compounds add a favorable olfactory effect to the desired product. The compounds are typically present in an amount of from about 0.001 to about 30.0 by weight of the total fragrance composition. Typically a more preferred embodiment would contain between 0.01% and 20% by weight and a most preferred embodiment would contain between 0.01% and 10% by weight. None of these examples shown are meant to be limiting or restrictive on the use of the material as stated.
[0019] One embodiment of the present inventions provides a method to modify, enhance or improve the odor properties of a fragrance composition by adding to said composition an olfactory effective quantity of the compound of formulas (I-VI). The invention may also be described as the use of any composition containing compound (I-VI) which can be advantageously employed in the fragrance industry as active ingredients.
[0020] Such compositions may contain or consist of at least one ingredient selected from a group consisting of a fragrance carrier and a fragrance base. Such compositions may also consist of at least one fragrance adjuvant.
[0021] Said fragrance carriers may be a liquid or a solid and typically do not significantly alter the olfactory properties of the fragrance ingredients. Some non-limiting examples of fragrance carriers include an emulsifying system, encapsulating materials, natural or modified starches, polymers, gums, pectins, gelatinous or porous cellular materials, waxes, and solvents which are typically employed in fragrance applications.
[0022] Said fragrance base refers to any composition comprising at least one fragrance co-ingredient. In general, these co-ingredients belong to chemical classes such as, but not limited to: alcohols, aldehydes, ketones, esters, ethers, acetals, oximes, acetates, nitriles, terpenes, saturated and unsaturated hydrocarbons and essential oils of natural or synthetic origins.
[0023] Table 2 provides an example of a formulated fragrance in which compounds of the present invention can be added.
[0000]
TABLE 2
Fragrance Formulation (ingredients are listed in parts per
formulation based on a total of 1000 parts by weight,
and also shown as WT % by formula amount) %
MATERIAL
Parts/1000
Wt %
Acetyl Tetralin
20
2.0
Ambretone
5
0.5
Benzy Acetate
100
10.0
Bergamot Synth
25
2.5
Citral Synth @ 10%
10
1.0
Citronellol, Laevo
40
4.0
Citronellyl Acetate, Laevo
5
0.5
Citronellyl Nitrile, Laevo
7
0.7
Cyclacet
45
4.5
Trepanol
15
1.5
DH Myrcenol
125
12.5
Dynascone @ 10%
5
0.5
Eugenol
5
0.5
Geranium Oil
10
1.0
Hedione
27
2.7
Heliotropine
8
0.8
Hindinol
5
0.5
Ionone, Beta
25
2.5
Iso Bornyl Methyl Ether
25
2.5
Iso E Super
25
2.5
Iso Propxy Ethyl Salicylate
10
1.0
Linalool Syn
85
8.5
Linalyl Acetate
15
1.5
Melonal @10%
5
0.5
Methyl Ionone, Gamma
55
5.5
Norlimbanol Dextro @ 10%
6
0.6
Orange Oil Brazilian
25
2.5
Phenyl Ethyl Alcohol
30
3.0
Rose Oxide
3
0.3
Styrallyl Acetate
8
0.8
Tamarine Base 41.310 G
3
0.3
Terpineol
20
2.0
Thesaron
7
0.7
Triplal Extra
3
0.3
Undecalactone, Gamma
20
2.0
Vanillin
5
0.5
Vertenex
85
8.5
Ylang Oil Extra
3
0.3
2-(3-methoxy-3-methylbutoxy)ethanal
80
8.0
[Compound 23; TABLE 1]
[0024] As used herein, olfactory effective quantity will be defined as the amount of said compound in a fragrance composition in which the individual component will contribute its characteristic olfactory properties, for example an olfactory property found to be more hedonistically appealing. A person of ordinary skill in the art may optimize the olfactory effect of the fragrance composition based on the incorporation of a fragrance compound of the present invention. The fragrance compounds may be used individually, or a part of mixture such that the sum of the effects of all fragrance ingredients present in the mixture yields a higher hedonistic rating. Therefore, the compounds embodied in the present invention can be employed to modify the characteristics of existing fragrance composition via their own olfactory properties or through additively effecting the contributions of other ingredient(s) present within the said composition. The quantity will vary widely depending on the other ingredients present, their relative amounts, the desired effect and the nature of the product.
Flavor Composition
[0025] Compounds of formulas (I-VI) can be employed alone or incorporated into mixtures to enhance already existing flavor compositions. These compounds add a favorable organoleptic property and effect to the desired product. The compounds are typically present in an amount of from about 0.01% to about 20.0% by weight of the total flavor composition. Typically a more preferred embodiment would contain between 0.01% and 10% by weight and a most preferred embodiment would contain between 0.01% and 5% by weight. None of these examples shown are meant to be limiting or restrictive on the use of the material as stated.
[0026] As used herein, organoleptic effective quantity will be defined as the amount of said compound in a flavor composition in which the individual component will contribute its characteristic flavor properties. However, the organoleptic effect of the flavor composition will be the sum of the effects of all flavor ingredients present. Therefore, the compounds embodied in the present invention can be employed to modify the characteristics of the flavor composition via their own organoleptic properties or through additively effecting the contributions of other ingredient(s) present within the said composition. The quantity will vary widely depending on the presence of other ingredients present, their relative amounts, the desired effect and the nature of the product.
[0027] The flavor carrier may be a liquid or a solid and typically do not significantly alter the olfactory or organoleptic properties of the flavor ingredients, respectively. Some non-limiting examples of flavor carriers include an emulsifying system, encapsulating materials, natural or modified starches, polymers, pectins, proteins, polysaccharides, gums and solvents which are typically employed in flavor applications.
[0028] As used herein, the term “flavor carrier” may also encompass the food or beverage to which the fragrance compound (i.e. compounds encompassed by formulas I-VI) are added. Examples of such foods or beverages include, but are not limited to carbonated fruit beverages, carbonated cola drinks, wine coolers, cordials, flavored water, powders for drinks (e.g., powdered sports or “hydrating” drinks), hard candy, soft candy, taffy, chocolates, sugarless candies, chewing gum, bubble gum, condiments, spices and seasonings, dry cereal, oatmeal, granola bars, soups, alcoholic beverages, energy beverages, juices, teas, coffees, salsa, gel beads, film strips for halitosis, gelatin candies, pectin candies, starch candies, lozenges, cough drops, throat lozenges, throat sprays, toothpastes and mouth rinses.
Intended Use
[0029] Compounds of formulas (I-VI) can be employed alone or incorporated into mixtures to enhance already existing fragrance compositions, solvents, media and the like. The use of such compounds is applicable to a wide variety of products in the perfume industry for consumer use such as, but not limited to: sprays, candles, air fresheners, perfumes, colognes, gels, soft solids, solids, devices for introducing said compounds into a space (e.g., a plug-in electrical device or a battery operated device), a liquid wicking system, personal care products such as soaps, talcum powder, antiperspirants, personal wash bar, personal wash liquid, personal wipe, deodorants, shampoos, conditioners, styling sprays, mousses, hair wipes, hair sprays, hair pomades, shower gels and shaving lotions; cosmetics such as oils, lotions and ointments; as well as detergents (e.g., synthetic detergent), fabric care products (e.g., fabric washing liquids and powders, fabric softeners, fabric conditioners), wipes, dishwashing liquids and powders, and household cleaning agents (e.g., hard surface cleaning liquids and powders and aqueous and non-aqueous sprays). The sprays can be aqueous or non-aqueous. The candles and gels can be opaque, translucent, or transparent, and may contain optional ingredients to enhance their appearance. The plug-in and battery-operated devices can include devices that vaporize the fragrance by heat, evaporation, or nebulization.
[0030] The use of such compounds is also applicable to a wide variety of products in the flavor industry such as, but not limited to: foodstuffs such as baked goods, dairy products, desserts, etc.; beverages such as juices, sodas, flavored waters, etc.; confectionaries such as sweets, hard candy, gums, gelatinous materials, etc. The flavor compositions can also be added to pharmaceutical applications, such as lozenges, strips to deliver medicines or personal care products (e.g. fresh breath strips), cough syrup or other liquid or bucally administered medicines.
Synthesis Details
[0031] Compounds of formula I may be isolated from the reaction of 3-methoxy-3-methyl-1-butoxide with an alkyl halide. Similarly, reaction of this alkoxide with an allyl halide results in a compound of formula (I) as well. Table 1 lists the olfactory properties of various novel compounds synthesized in accordance to formula (I). In particular, the unsaturated 3-methoxy-3-methyl-1-butanol ether derivatives described in the present invention all contain citrus and/or green notes incorporated into their odor compositions. Saturation of these olefinic substituents via hydrogenation results in a woody, fruitier olfactory character.
[0032] Compounds encompassed by formula II can be synthesized via simple condensation reactions between the alcohol, 3-methoxy-3-methyl-1-butanol, and the respective carboxylic acid. Alternatively, compounds of formula (II) can be synthesized by direct reaction of the alcohol with the respective acid chloride. Table 1 lists the odor characteristics of various novel compounds synthesized in accordance to formula (II).
[0033] The syntheses of all compounds related to formula (II) proceed with high yields. As represented in Table 1, the majority of the alkyl 3-methoxy-3-methyl-1-butanol esters have a strong fruity note associated with them.
[0034] Compounds of formula III may be isolated from the reaction of 3-methoxy-3-methyl-1-butanol (Solfit™) with an alkyl chloroformate. The synthesis proceeds in a straight forward, facile manner. Table 1 lists the olfactory properties of various novel compounds synthesized in accordance to formula (III). The fragrance compounds encompassed by formula III generally maintain a light and soft quality.
[0035] The syntheses of compounds (glycolates) encompassed by formula (IV) proceeded smoothly and in high yield. Simple esterification of various alkoxy carboxylic acids with 3-methoxy-3-methyl-1-butanol in the presence of a catalytic amount of acid resulted in the desired products. Glycolates of this nature have a consistent light, powdery musk property. The musk qualities associated with these chemical entities have been reported in other glycolate-type compounds (See, e.g., U.S. Published Application No. 2006/0052277, which is hereby incorporated by reference).
[0036] The present inventors have found that glycolates encompassed by formula (V) can be isolated in high yields when the reaction specifically employs 2-(3-methoxy-3-methylbutoxy)acetic acid with a respective alcohol to undergo esterification in similar fashion to the syntheses of compounds of formula (IV). Alternatively, reactions involving an alkyl halo-acetate with 3-methoxy-3-methyl-1-butoxide result in a low yield of the desired glycolate due to a mixture of undesired side products.
[0037] The synthesis of the compound of formula (VI) in which n=0 and R 6 =hydrogen proceeded smoothly via its dimethyl acetal precursor. Cleavage of the acetal group under acidic conditions afforded the respective acetaldehyde. This compound can also be synthesized via ozonolysis of allyl 3-methoxy-3-methyl-1-butanol ether. Such an approach was taken for the compound of formula (VI) in which n=0 and R 6 =methyl. Both compounds possess odor characteristics which can be described as clean, melon-like and fresh with very strong diffusive properties.
[0038] The synthesis of compounds of formula (VI) in which n=1 and R 6 =hydrogen or a methyl group was based on a revised adaptation of previously reported syntheses between alcohols and α-β-unsaturated aldehydes (U.S. Pat. No. 2,694,733; Feldman, D. P.; Stonkus, V. V.; Shimanskaya, M. V.; Avots, A. A. Russ. J. Gen. Chem. 1995, 65, 250-253). In the present case, acrolein and crotonaldehyde have been chosen as the α-β-unsaturated aldehydes. In each of the previously reported syntheses for reactions of this type, specific conditions involving the buffer capacity of the system were stressed. The syntheses reported here proceeded with extremely low yields (<5%) when employing such conditions. The present inventors found that the presence of a catalytic amount of acid greatly promotes the formation of the desired aldehydes. As listed in Table 1, such aldehydes of this nature have a much more waxy, fatty-type aroma than the acetaldehyde analogues (n=0).
Example 1
[0039] This example illustrates the synthesis of 3-(2,2-dimethoxyethoxy)-1-methoxy-1,1-dimethylpropane.
[0000]
[0040] A suspension of sodium hydride (11.8 g, 0.47 mol) in anhydrous THF (400 mL) was warmed to approximately 40° C. under an inert atmosphere. A portion of 3-methoxy-3-methyl-1-butanol (50.0 g, 0.42 mol) was then added dropwise via syringe over a period of 20 minutes during which time the temperature of the mixture was slowly raised to 70° C. at 5 degree intervals. After one hour, bromoacetaldehyde dimethyl acetal (54.0 mL, 0.46 mol) was added dropwise via syringe over a period of 30 minutes and the mixture was stirred vigorously at 70° C. for 16 hours. After this time, the mixture was cooled to room temperature, treated with H 2 O (200 mL) and extracted with diethyl ether (3×200 mL). The organic phases were collected and washed with saturated NaHCO 3 (aq.) (2×200 mL) followed by H 2 O (2×100 mL). The organic phase was dried with MgSO 4 and the solvent was removed under reduced pressure. The resulting light yellow liquid was fractionally distilled (87° C., 3.00 torr) to yield the desired colorless, pure ether (57.0 g, 65.5%). Odor: weak, marine-like, clean. GC/MS(EI): m/z(%)—206(1), 191(1), 159(1), 143(3), 127(4), 111(5), 97(3), 89(2), 85(13), 75(100), 73(37), 69(8), 58(4), 55(3), 47(8), 45(15), 43(7). 1 H NMR (CDCl 3 ); δ 1.16 (s, 6H), 1.81 (t, J=7.33 Hz, 2H), 3.17 (s, 3H), 3.38 (s, 6H), 3.47 (d, J=5.04 Hz, 2H), 3.55 (t, J=7.33 Hz, 2H), 4.48 (t, J=5.04 Hz, 1H). 13 C NMR (CDCl 3 ): δ 25.4, 39.3, 49.2, 53.9, 68.0, 70.8, 73.7, 102.9.
Example 2
[0041] This example illustrates the synthesis of 1-methoxy-1,1-dimethyl-3-prop-2-enyloxypropane.
[0000]
[0042] This compound was synthesized employing a procedure analogous to Example 1 using 3-methoxy-3-methyl-1-butanol (25.0 g, 0.21 mol) and allyl chloride (16.4 mL, 0.20 mol). The isolated crude material was fractionally distilled (22° C., 0.80 torr) resulting in a colorless, pure liquid (22.5 g, 70.8%). Odor: citrus, herbal, pine, sweet orange, candy. GC/MS(EI): m/z(%)—158(1), 143(2), 126(1), 111(3), 97(1), 87(9), 85(7), 73(100), 71(14), 57(9), 55(9), 45(7), 43(13), 41(25). 1 H NMR (CDCl 3 ): δ 1.16 (s, 6H), 1.80 (t, J=7.33 Hz, 2H), 3.17 (s, 3H), 3.50 (t, J=7.79 Hz, 2H), 3.96 (d, J=5.96 Hz, 2H), 5.15 (dd, J=11.9 Hz, 1H), 5.25 (dd, J=18.8 Hz, 1H), 5.90 (m, 1H). 13 C NMR (CDCl 3 ): δ 25.4, 39.3, 49.2, 66.7, 71.9, 73.8, 116.8, 135.1.
Example 3
[0043] This example illustrates the synthesis of 1-methoxy-1,1-dimethyl-3-(2-methylprop-2-enyloxy)propane.
[0000]
[0044] This compound was synthesized employing a procedure analogous to Example 1 using 3-methoxy-3-methyl-1-butanol (25.0 g, 0.21 mol) and methallyl chloride (20.7 mL, 0.21 mol). The isolated crude material was fractionally distilled (103° C., 36.0 torr) resulting in a colorless, pure liquid (28.8 g, 79.3%). Odor: citrus, green, lemon, slight orange. GC/MS(EI): m/z(%)—172(1), 157(1), 140(1), 125(9), 111(2), 101(2), 95(7), 87(9), 85(10), 73(100), 71(11), 69(14), 55(36), 45(9), 43(12), 41(10). 1 H NMR (CDCl 3 ): δ 1.17 (s, 6H), 1.72 (s, 3H), 1.81 (t, J=6.87 Hz, 2H), 3.18 (s, 3H), 3.47 (t, 0.1=7.33 Hz, 2H), 3.85 (s, 2H), 4.87 (s, 1H), 4.94 (s, 1H). 13 C NMR (CDCl 3 ): δ 19.5, 25.5, 39.4, 49.2, 66.5, 73.8, 75.0, 111.8, 142.6.
Example 4
[0045] This example illustrates the synthesis of 1-methoxy-1,1-dimethyl-3-(3-methylbut-2-enyloxy)propane.
[0000]
[0046] This compound was synthesized employing a procedure analogous to Example 1 using 3-methoxy-3-methyl-1-butanol (25.0 g, 0.21 mol) and prenyl chloride (23.9 mL, 0.21 mol). The isolated crude material was fractionally distilled (66° C., 3.00 torr) resulting in a colorless, pure liquid (30.4 g, 77.0%). Odor: green, chocolate, sweet, bitter. GC/MS(EI): m/z(%)—186(1), 171(1), 154(1), 139(58), 103(4), 85(44), 78(4), 73(100), 69(86), 55(11), 45(12), 43(12), 41(26). 1 H NMR (CDCl 3 ): δ 1.15 (s, 6H), 1.66 (s, 3H), 1.73 (s, 3H), 1.79 (t, J=7.33 Hz, 2H), 3.17 (s, 3H), 3.48 (t, J=7.33 Hz, 2H), 3.93 (d, J=6.87 Hz, 2H), 5.34 (t, J=7.33 Hz, 1H). 13 C NMR (CDCl 3 ): δ 18.1, 25.5, 25.9, 39.2, 49.2, 66.5, 67.5, 73.8, 121.2, 136.8.
Example 5
[0047] This example illustrates the synthesis of 1-methoxy-1,1-dimethyl-3-propoxypropane.
[0000]
[0048] A portion of the unsaturated ether, 1-methoxy-1,1-dimethyl-3-prop-2-enyloxypropane, (20.0 g, 0.13 mol) was dissolved in absolute EtOH (120 mL) and to this was added 5% (w/w) catalyst (5% Pd—C). The suspension was stirred at ambient temperature and treated with H 2 (250 psi) for 16 hours. Upon completion, the suspension was filtered through a glass frit (M) filter packed with filter paper and celite and rinsed with ethyl acetate. The solvent was removed under reduced pressure via rotary evaporation affording a light yellow liquid which was fractionally distilled (58° C., 9.70 torr) to yield the desired colorless, pure ether (11.9 g, 59.1%). Odor: woody, floral, slightly bitter banana. GC/MS(EI): m/z(%)—160(1), 145(2), 128(8), 113(12), 87(8), 73(100), 71(20), 55(7), 43(24), 41(11). 1 H NMR (CDCl 3 ): δ 0.90 (t, J==7.33 Hz, 3H), 1.16 (s, 6H), 1.58 (m, 2H), 1.78 (t, J=7.33 Hz, 2H), 3.17 (s, 3H), 3.35 (t, J=6.42 Hz, 2H), 3.47 (t, J=7.79 Hz, 2H). 13 C NMR (CDCl 3 ): δ 10.7, 23.0, 25.5, 39.2, 49.2, 67.0, 72.8, 73.9.
Example 6
[0049] This example illustrates the synthesis of 1-methoxy-1,1-dimethyl-3-(2-methylpropoxyl)propane.
[0000]
[0050] This compound was synthesized employing a procedure analogous to Example 5 using 1-methoxy-1,1-dimethyl-3-(2-methylprop-2-enyloxy)propane (20.0 g, 0.12 mol). The isolated crude material was fractionally distilled (53° C., 5.00 torr) resulting in a colorless, pure liquid (16.0 g, 80.0%). Odor: woody, green pear, slight chocolate. GC/MS(EI): m/z(%)—174(1), 159(1), 142(5), 127(3), 99(2), 87(9), 85(5), 73(100), 71(17), 57(26), 43(11), 41(14). 1 H NMR (CDCl 3 ): δ 0.88 (d, J=6.87 Hz, 6H), 1.16 (s, 6H), 1.78 (t, J=7.33 Hz, 2H), 1.83 (m, 1H), 3.15 (d, J=6.42 Hz, 2H), 3.18 (s, 3H), 3.47 (J=7.33 Hz, 2H). 13 C NMR (CDCl 3 ): δ 19.5, 25.5, 28.5, 39.2, 49.2, 67.2, 73.9, 78.1.
Example 7
[0051] This example illustrates the synthesis of 1-methoxy-1,1-dimethyl-3-(3-methylbutoxyl)propane.
[0000]
[0052] This compound was synthesized employing a procedure analogous to Example 5 using 1-methoxy-1,1-dimethyl-3-(3-methylbut-2-enyloxy)propane (20.0 g, 0.11 mol). The isolated crude material was distilled via Kugelrohr apparatus (25° C., 0.15 torr) resulting in a colorless, pure liquid (9.93 g, 49.2%). Odor: chocolate, liqueur, sour, slightly pungent. GC/MS(EI): m/z(%)—188(1), 173(1), 156(4), 141(11), 99(7), 87(11), 73(100), 71(38), 55(11), 43(30), 41(14). 1 H NMR (CDCl 3 ): δ 0.89 (d, J=6.87 Hz, 6H), 1.16 (s, 6H), 1.45 (q, J=6.87 Hz, 2H), 1.67 (m, 1H), 1.78 (t, J=7.33 Hz, 2H), 3.18 (s, 3H), 3.41 (t, J=6.87 Hz, 2H), 3.47 (t, J=7.33 Hz, 2H). 13 C NMR (CDCl 3 ): δ 22.7, 25.2, 25.5, 38.7, 39.2, 49.2, 67.1, 69.5, 73.9.
Example 8
[0053] This example illustrates the synthesis of 3-methoxy-3-methylbutyl formate.
[0000]
[0054] A portion of 3-methoxy-3-methyl-1-butanol (30.0 g, 0.25 mol) was dissolved in neat formic acid (60.9 g, 1.27 mol) and was stirred at ambient temperature for approximately 6 hours. Upon completion (monitored via GC), H 2 O (100 mL) was added and the solution was extracted with diethyl ether (3×75 mL). The organic phases were collected and washed with saturated NaHCO 3 (aq.) (3×100 mL) followed by H 2 O (2×50 mL). The organic phase was dried with MgSO 4 and the solvent was removed under reduced pressure. The resulting light yellow liquid was fractionally distilled (57° C., 9.00 torr) to yield the desired colorless, pure product (20.9 g, 56.3%). Odor: woody, camphoraceous, dry, chemical. GC/MS(EI): m/z(%)—146(1), 131(1), 85(43), 73(100), 69(14), 55(15), 43(12), 41(13). 1 H NMR (CDCl 3 ): δ 1.18 (s, 6H), 1.85 (t, J=7.33 Hz, 2H), 3.18 (s, 3H), 4.27 (t, J=7.33 Hz, 2H), 8.03 (s, 1H). 13 C NMR (CDCl 3 ): δ 25.2, 38.3, 49.3, 60.7, 73.5, 161.3.
Example 9
[0055] This example illustrates the synthesis of 3-methoxy-3-methylbutyl propanoate.
[0000]
[0056] A portion of 3-methoxy-3-methyl-1-butanol (25.0 g, 0.21 mol) was dissolved in anhydrous THF (200 mL) and purged with nitrogen. To this solution was added the propionyl chloride (20.2 mL, 0.23 mol) dropwise over a 15-minute period. The solution was stirred at ambient temperatures for 2 hours. Upon completion (monitored via GC), H 2 O (100 mL) was added and the solution was extracted with diethyl ether (3×75 mL). The organic phases were collected and washed with saturated NaHCO 3 (aq.) (3×100 mL) followed by H 2 O (2×50 mL). The organic phase was dried with MgSO 4 and the solvent was removed under reduced pressure. The resulting yellow liquid was fractionally distilled (110° C., 36.0 torr) to yield the desired colorless, pure product (29.4 g, 80.1%). Odor: fruity, banana, floral, bubble gum. GC/MS(EI): m/z(%)—173(1), 159(1), 143(1), 101(1), 85(57), 73(100), 69(27), 57(24), 55(16), 43(10), 41(10). 1 H NMR (CDCl 3 ): δ 1.12 (t, J=7.33 Hz, 3H), 1.17 (s, 6H), 1.81 (t, J=7.33 Hz, 2H), 2.30 (t, J=7.33 Hz, 2H), 3.18 (s, 3H), 4.15 (t, J=7.33 Hz, 2H). 13 C NMR (CDCl 3 ): δ 9.2, 25.3, 27.7, 38.3, 49.3, 61.0, 73.6, 174.6.
Example 10
[0057] This example illustrates the synthesis of 3-methoxy-3-methylbutyl 2-methylpropanoate.
[0000]
[0058] This compound was synthesized employing a procedure analogous to Example 9 using 3-methoxy-3-methyl-1-butanol (25.0 g, 0.21 mol) and isobutyryl chloride (24.4 mL, 0.23 mol). The isolated crude material was fractionally distilled (58° C., 3.00 torr) resulting in a colorless, pure liquid (29.6 g, 74.2%). Odor: fruity, green, pear, apple, sour. GC/MS(EI): m/z(%)—188(1), 173(1), 157(1), 115(1), 101(1), 85(55), 73(100), 71(12), 69(25), 55(13), 43(26), 41(15). 1 H NMR (CDCl 3 ): δ 1.14 (d, J=7.33 Hz, 6H), 1.18 (s, 6H), 1.81 (t, J=7.33 Hz, 2H), 2.51 (m, 1H), 3.18 (s, 3H), 4.15 (t, J=7.33 Hz, 2H). 13 C NMR (CDCl 3 ): δ 19.0, 25.3, 34.1, 38.3, 49.3, 61.0, 73.6, 177.3.
Example 11
[0059] This example illustrates the synthesis of 3-methoxy-3-methylbutyl (2E)-2-methylbut-2-enoate.
[0000]
[0060] Portions of tiglic acid (12.6 g, 0.13 mol) and p-toluene sulfonic acid (1.21 g, 6.35 mmol) were dissolved in 3-methoxy-3-methyl-1-butanol (45.0 g, 0.38 mol) and stirred vigorously while heated at 40° C. for 27 hours. After this time, the solution was cooled to room temperature and diethyl ether was added (100 mL). The solution was washed with saturated NaHCO 3 (3×75 mL) followed by H 2 O (100 mL). The aqueous fractions were back-extracted with diethyl ether (50 mL) and the organic layers were dried with MgSO 4 . The solvent removed via rotary evaporation and the resulting clear liquid was fractionally distilled (76° C., 1.23 torr) to afford the desired colorless, pure ester (5.25 g, 20.8%). Odor: sugary, sweet sap, green. GC/MS(EI): m/z(%)—200(1), 185(1), 169(1), 127(1), 101(6), 85(50), 73(100), 69(16), 55(26), 43(7), 41(8). 1 H NMR (CDCl 3 ): δ 1.18 (s, 6H), 1.76 (d, J=7.79 Hz, 3H), 1.81 (s, 3H), 1.85 (t, J=7.33 Hz, 2H), 3.19 (s, 3H), 4.21 (t, J=7.33 Hz, 2H), 6.83 (dq, J=8.71 Hz, 1H). 13 C NMR (CDCl 3 ): δ 12.1, 14.4, 25.4, 38.3, 49.3, 61.1, 73.6, 128.8, 137.0, 168.3.
Example 12
[0061] This example illustrates the synthesis of 3-methoxy-3-methylbutyl methoxyformate.
[0000]
[0062] A portion of 3-methoxy-3-methyl-1-butanol (30.0 g, 0.25 mol) was dissolved in anhydrous THF (100 mL) and purged with nitrogen. To this solution was added methyl chloroformate (21.5 mL, 0.28 mol) dropwise. The solution was cooled to 0° C. and stirred vigorously. To this solution was added pyridine (22.6 mL, 0.28 mol) slowly, which resulted in a very exothermic reaction and the immediate formation of a white precipitate. Upon completion (monitored via GC) (<1 hour), H 2 O (100 mL) was added and the solution was extracted with diethyl ether (3×75 mL). The organic phases were collected and washed with 10% HCl (aq.) (3×75 mL) followed by brine solution (2×50 mL) and H 2 O (2×50 mL). The organic phase was dried with MgSO 4 and the solvent was removed under reduced pressure. The resulting yellow liquid was fractionally distilled (84° C., 9.00 torr) to yield the desired colorless, pure product (35.7 g, 80.0%). Odor: weak, light, green, floral. GUNNED: m/z(%)—176(1), 161(1), 101(2), 85(43), 73(100), 69(22), 59(5), 55(12), 45(6), 43(8), 41(8). 1 H NMR (CDCl 3 ); δ 1.17 (s, 6H), 1.86 (t, J=7.33 Hz, 2H), 3.17 (s, 3H), 3.75 (s, 3H), 4.22 (t, J=7.33 Hz, 2H). 13 C NMR (CDCl 3 ): δ 25.3, 38.3, 49.3, 54.8, 64.8, 73.4, 155.9.
Example 13
[0063] This example illustrates the synthesis of 3-methoxy-3-methylbutyl prop-2-enyloxyformate.
[0000]
[0064] This compound was synthesized employing a procedure analogous to Example 12 using 3-methoxy-3-methyl-1-butanol (25.0 g, 0.21 mol) and allyl chloroformate (25.5 mL, 0.23 mol). The isolated crude material was fractionally distilled (86° C., 3.00 torr) resulting in a colorless, pure liquid (37.3 g, 87.0%). Odor: weak, soft chocolate, airy. GC/MS(EI): m/z(%)—202(1), 187(1), 146(1), 108(1), 101(4), 85(45), 73(100), 69(39), 55(11), 43(8), 41(17). 1 H NMR (CDCl 3 ); δ 1.18 (s, 6H), 1.87 (t, J=7.79 Hz, 2H), 3.18 (s, 3H), 4.23 (t, J=7.33 Hz, 2H), 4.60 (d, J=5.50 Hz, 2H), 5.25 (dd, J=10.54 Hz, 1H), 5.34 (dd, J=18.33 Hz, 1H), 5.91 (m, 1H). 13 C NMR (CDCl 3 ): δ 25.3, 38.3, 49.3, 64.8, 68.4, 73.4, 118.9, 131.8, 155.1.
Example 14
[0065] This example illustrates the synthesis of 3-methoxy-3-methylbutyl propoxyformate.
[0000]
[0066] A portion of the unsaturated carbonate, 3-methoxy-3-methylbutyl prop-2-enyloxyformate, (20.0 g, 99.0 mmol) was dissolved in absolute EtOH (120 mL) and to this was added 1% (w/w) catalyst (5% Pd—C). The suspension was stirred at ambient temperature and treated with H 2 (250 psi) for 2 hours. Upon completion (monitored via GC), the suspension was filtered through a glass frit (M) filter packed with filter paper and celite and rinsed with ethyl acetate. The solvent was removed under reduced pressure via rotary evaporation affording a light yellow liquid which was fractionally distilled (86° C., 3.20 torr) to yield the desired colorless, pure product (18.5 g, 91.5%). Odor: weak, soft musk, light vanilla. GC/MS(EI): m/z(%)—204(1), 189(1), 101(2), 85(34), 73(100), 69(18), 55(9), 43(12), 41(12). 1 H NMR (CDCl 3 ): 0.95 (t, J=7.79 Hz, 3H), 1.18 (s, 6H), 1.67 (m, 2H), 1.87 (t, J=7.79 Hz, 2H), 3.18 (s, 3H), 4.08 (t, J=6.87 Hz, 2H), 4.22 (t, J=7.33 Hz, 2H). 13 C NMR (CDCl 3 ): δ 10.3, 22.1, 25.3, 38.3, 49.3, 64.6, 69.6, 73.6, 155.6.
Example 15
[0067] This example illustrates the synthesis of 3-methoxy-3-methylbutyl 2-methoxyacetate.
[0000]
[0068] A portion of methoxyacetic acid (20 g, 0.22 mol) was dissolved in CH 2 Cl 2 (160 mL) and dimethylformamide (40 mL). The solution was treated with oxalyl chloride (27.1 mL, 0.31 mol) in CH 2 Cl 2 (100 mL) dropwise and stirred at room temperature for 2 hours. The temperature was then increased to 40° C. and the solution was stirred for an additional 40 minutes. The solution was then cooled to room temperature, purged with nitrogen gas for 5 minutes and then cooled to 0° C. The cooled solution was treated with a mixture of 3-methoxy-3-methyl-1-butanol (26.2 g, 0.22 mol) and pyridine (19.8 mL, 0.22 mol) in CH 2 Cl 2 (50 mL) dropwise and was stirred at that temperature for 2 hours. Upon completion, 10% HCl (aq.) was added and the organic layer was washed (3×100 mL) followed by H 2 O (100 mL). The organic phase was dried with MgSO 4 and the solvent was removed under reduced pressure. The resulting yellow liquid was fractionally distilled (71° C., 1.26 torr) to yield the desired colorless, pure product (25.8 g, 61.1%). Odor: weak, fruity, slight coconut, powder musk. GC/MS(EI): m/z(%)—190(1), 175(1), 128(1), 85(37), 73(100), 55(9), 45(24), 41(11). 1 H NMR (CDCl 3 ) δ 1.17 (s, 6H), 1.84 (t, J=7.79 Hz, 2H), 3.17 (s, 3H), 3.43 (s, 3H), 4.00 (s, 2H), 4.25 (t, J=7.33 Hz, 2H). 13 C NMR (CDCl 3 ): δ 25.3, 38.3, 49.3, 59.4, 61.6, 70.0, 73.5, 170.4.
Example 16
[0069] This example illustrates the synthesis of 3-methoxy-3-methylbutyl 2-ethoxyacetate.
[0000]
[0070] Portions of ethoxyacetic acid (50 g, 0.47 mol) and p-toluenesulfonic acid (4.50 g, 23.5 mmol) were dissolved in 3-methoxy-3-methyl-1-butanol (167 g, 1.41 mol) and stirred vigorously while heated at 40° C. for 5 hours. After this time, the solution was cooled to room temperature and diethyl ether was added (100 mL). The solution was washed with saturated NaHCO 3 (3×75 mL) followed by H 2 O (100 mL). The aqueous fractions were back-extracted with diethyl ether (50 mL) and the organic layers were dried with MgSO 4 . The solvent removed via rotary evaporation and the resulting clear liquid was fractionally distilled (70° C., 1.04 torr) to afford the desired colorless, pure product (68.4 g, 71.2%). Odor: powder musk, fresh, soft, light, clean. GC/MS(EI): m/z(%)—204(1), 189(1), 128(4), 85(32), 73(100), 59(9), 55(7), 45(7). 1 H NMR (CDCl 3 ); δ 1.17 (s, 6H), 1.24 (t, J=6.87 Hz, 3H), 1.84 (t, J=7.33 Hz, 2H), 3.17 (s, 3H), 3.57 (q, J=7.33 Hz, 2H), 4.04 (s, 2H), 4.25 (t, J=7.79 Hz, 2H). 13 C NMR (CDCl 3 ): δ 15.1, 25.3, 38.3, 49.3, 61.6, 67.3, 68.2, 73.5, 170.7.
Example 17
[0071] This example illustrates the synthesis of 3-methoxy-3-methylbutyl 2-(methylethoxy)acetate.
[0000]
[0072] This compound was synthesized employing a procedure analogous to Example 16 using 3-methoxy-3-methyl-1-butanol (56.0 g, 0.48 mol) and methylethoxyacetic acid (14.0 g, 0.12 mol). The isolated crude material was fractionally distilled (72° C., 0.96 torr) resulting in a colorless, pure liquid (10.3 g, 39.9%). Odor: very weak powder musk. GC/MS(EI): m/z(%)—218(1), 203(1), 187(1), 160(1), 145(1), 128(8), 101(4), 85(40), 73(100), 69(52), 55(8), 45(10), 43(24), 41(12). 1 H NMR (CDCl 3 ): δ 1.16 (s, 6H), 1.19 (d, J=5.96 Hz, 6H), 1.83 (t, J=7.33 Hz, 2H), 3.17 (s, 3H), 3.65 (m, 1H), 4.04 (s, 2H), 4.23 (t, J=7.33 Hz, 2H). 13 C NMR (CDCl 3 ): δ 21.8, 25.2, 38.5, 49.2, 61.5, 65.9, 72.6, 73.5, 170.9.
Example 18
[0073] This example illustrates the synthesis of 2-(3-methoxy-3-methylbutoxy)acetic acid.
[0000]
[0074] A suspension of sodium hydride (4.70 g, 0.19 mol) in anhydrous THF (100 mL) was warmed to approximately 40° C. under an inert atmosphere. A portion of 3-methoxy-3-methyl-1-butanol (20.0 g, 0.17 mol) was then added dropwise via syringe over a period of 20 minutes during which time the temperature of the mixture was slowly raised to 70° C. at 5 degree intervals. After one hour, sodium bromoacetate (28.2 g, 0.18 mol) was added in small portions over a period of 20 minutes and the mixture was stirred vigorously at 70° C. for 4 hours. Upon completion (monitored via GC), the mixture was cooled to room temperature, treated with diethyl ether (100 mL) and washed with 10% HCl (aq.) (3×75 mL) followed by brine solution (100 mL). The organic phase was dried with MgSO 4 and the solvent was removed under reduced pressure. The crude light yellow liquid was not purified further for use in subsequent reactions. Yield: (29.2 g, 98.0%). Odor: harsh, chemical. GC/MS(EI): m/z(%)—176(1), 161(1), 129(2), 85(30), 73(100), 69(14), 55(9), 45(7). 1 H NMR (CDCl 3 ): δ 1.21 (s, 6H), 1.83 (t, J=5.96 Hz, 2H), 3.21 (s, 3H), 3.66 (t, J=5.96 Hz, 2H), 3.75 (s, 1H), 4.06 (s, 2H). 13 C NMR (CDCl 3 ): δ 25.2, 39.3, 49.4, 68.3, 68.6, 75.0, 173.1.
Example 19
[0075] This example illustrates the synthesis of methyl 2-(3-methoxy-3-methylbutoxy)acetate.
[0000]
[0076] A portion of 2-(3-methoxy-3-methylbutoxy)acetic acid (Example 18) (28.0 g, 0.16 mol) was diluted with methanol (50 mL) and treated with p-toluenesulfonic acid (1.51 g, 7.95 mmol) and stirred vigorously at 40° C. for 3 hours. After this time, the solution was cooled to room temperature and diethyl ether was added (100 mL). The solution was washed with saturated NaHCO 3 (3×75 mL) followed by H 2 O (100 mL). The aqueous fractions were back-extracted with diethyl ether (50 mL) and the organic layers were dried with MgSO 4 . The solvent removed via rotary evaporation and the resulting light yellow liquid was fractionally distilled (60° C., 1.00 torr) to afford the desired colorless, pure product (18.9 g, 62.6%). Odor: metallic green, plastic. GC/MS(EI): m/z(%)—190(1), 175(1), 143(3), 99(8), 85(67), 73(100), 69(27), 55(11), 45(25). 1 H NMR (CDCl 3 ): δ 1.16 (s, 6H), 1.84 (t, J=7.33 Hz, 2H), 3.16 (s, 3H), 3.58 (t, J=7.33 Hz, 2H), 3.73 (s, 3H), 4.06 (s, 2H). 13 C NMR (CDCl 3 ): δ 25.4, 39.1, 49.2, 51.9, 68.2, 68.4, 73.7, 171.0.
Example 20
[0077] This example illustrates the synthesis of ethyl 2-(3-methoxy-3-methylbutoxy)acetate.
[0000]
[0078] This compound was synthesized employing a procedure analogous to Example 19 using 2-(3-methoxy-3-methylbutoxy)acetic acid (14.0 g, 79.5 mmol) and ethanol (28 mL). The isolated crude material was fractionally distilled (65° C., 0.97 torr) resulting in a colorless, pure liquid (7.50 g, 46.9%). Odor: vegetable green, spicy, plastic. GC/MS(EI): m/z(%)—204(1), 189(1), 157(3), 99(10), 85(64), 73(100), 69(24), 55(9), 45(11). 1 H NMR (CDCl 3 ): δ 1.16 (s, 6H), 1.27 (t, J=7.33 Hz, 3H), 1.84 (t, J=7.33 Hz, 2H), 3.17 (s, 3H), 3.59 (t, J=7.33 Hz, 2H), 4.04 (s, 2H), 4.20 (q, J=7.33 Hz, 2H). 13 C NMR (CDCl 3 ): δ 14.3, 25.4, 39.1, 49.3, 60.9, 68.2, 68.6, 73.7, 170.6.
Example 21
[0079] This example illustrates the synthesis of methylethyl 2-(3-methoxy-3-methylbutoxy)acetate.
[0000]
[0080] This compound was synthesized employing a procedure analogous to Example 19 using 2-(3-methoxy-3-methylbutoxy)acetic acid (28.0 g, 0.16 mol) and 2-propanol (75 mL). The isolated crude material was fractionally distilled (70° C., 0.93 torr) resulting in a colorless, pure liquid (21.4 g, 61.8 To). Odor: green, licorice, slightly mint, fresh. GC/MS(EI): m/z(%)—218(1), 203(1), 188(1), 171(1), 146(1), 129(5), 119(3), 99(12), 85(68), 73(100), 69(34), 55(9), 45(15), 43(21), 41(13). 1 H NMR (CDCl 3 ): δ 1.17 (s, 6H), 1.25 (d, J=6.42 Hz, 6H), 1.85 (t, J=7.33 Hz, 2H), 3.17 (s, 3H), 3.60 (t, J=7.33 Hz, 2H), 4.01 (s, 2H), 5.08 (m, 1H). 13 C NMR (CDCl 3 ): δ 21.9, 25.4, 39.1, 49.3, 68.2, 68.5, 68.7, 73.7, 170.2.
Example 22
[0081] This example illustrates the synthesis of 3-methoxy-3-methylbutyl 4-methylbenzenesulfonate.
[0000]
[0082] A portion of p-toluenesulfonyl chloride (32.9 g, 0.17 mol) was dissolved in pyridine (50 mL) and cooled to 0° C. To this solution was added 3-methoxy-3-methyl-1-butanol (20.0 g, 0.17 mol) dropwise slowly via syringe. A white precipitate formed immediately and the mixture was stirred at 0° C. for one hour followed by an additional 3 hours at room temperature. After this time, the mixture was treated with diethyl ether (100 mL) and washed with 10% HCl (aq.) (3×75 mL), saturated NaHCO 3 (aq.) (2×75 mL) and H 2 O (2×50 mL). The organic phase was dried with MgSO 4 and the solvent was removed under reduced pressure. The resulting crude light yellow liquid was not purified further for use in subsequent reactions. Yield: (42.0 g, 91.1%). Odor: odorless. GC/MS(EI): m/z(%)—272(1), 257(1), 207(1), 173(1), 155(4), 91(21), 85(55), 73(100), 69(17), 65(10), 55(8), 45(5), 43(6). 1 H NMR (CDCl 3 ): δ 1.11 (s, 6H), 1.85 (t, J=7.33 Hz, 2H), 2.43 (s, 3H), 3.08 (s, 3H), 4.11 (t, J=7.33 Hz, 2H), 7.33 (d, J=8.25 Hz, 2H), 7.77 (d, J=8.25 Hz, 2H). 13 C NMR (CDCl 3 ): δ 21.7, 25.2, 38.8, 49.3, 67.4, 73.3, 128.0, 129.9, 133.2, 144.8.
Example 23
[0083] This example illustrates the synthesis of 1-methoxy-3-(3-methoxy-3-methylbutoxy)-1,1-dimethylpropane.
[0000]
[0084] A suspension of sodium hydride (2.35 g, 93.1 mmol) in anhydrous THF (60 mL) was warmed to approximately 40° C. under an inert atmosphere. A portion of 3-methoxy-3-methyl-1-butanol (10.0 g, 84.6 mmol) was then added dropwise via syringe over a period of 20 minutes during which time the temperature of the mixture was slowly raised to 70° C. at 5 degree intervals. After one hour, the sulfonate product from Example 22 (23.0 g, 84.6 mmol) was added in small portions After this time, the mixture was cooled to room temperature, treated with diethyl ether (100 mL) and washed with saturated NaHCO 3 (aq.) (2×100 mL) followed by brine solution (2×50 mL). The organic phase was dried with MgSO 4 and the solvent was removed under reduced pressure. The resulting light yellow liquid was fractionally distilled (73° C., 0.95 torr) to yield the desired colorless, pure ether (13.2 g, 71.7%). Odor: mold, mildew. GC/MS(EI): m/z(%)—218(1), 171(1), 154(2), 139(21), 115(3), 99(10), 85(39), 73(100), 69(36), 55(9), 45(18), 43(14), 41(12). 1 H NMR (CDCl 3 ); δ 1.15 (s, 12H), 1.77 (t, J=7.33 Hz, 4H), 3.17 (s, 6H), 3.47 (t, J=7.33 Hz, 4H). 13 C NMR (CDCl 3 ): δ 25.5, 39.3, 49.2, 67.2, 73.8.
Example 24
[0085] This example illustrates the synthesis of 1-methoxy-1,1-dimethyl-3-(1-methylprop-2-enyloxy)propane.
[0000]
[0086] This compound was synthesized employing a procedure analogous to Example 23 using 3-methoxy-3-methylbutyl 4-methylbenzenesulfonate (37.9 g, 0.14 mol) and 3-butene-2-ol (12.4 mL, 0.14 mol). The isolated crude material was fractionally distilled (40° C., 2.45 torr) resulting in a colorless, pure liquid (14.0 g, 58.6%). Odor: strong, mint, citrus, rose. GC/MS(EI): m/z(%)—172(1), 157(1), 117(1), 95(3), 85(14), 73(100), 69(12), 55(33), 45(6), 41(8). 1 H NMR (CDCl 3 ): δ 1.15 (s, 6H), 1.22 (d, J=5.96 Hz, 3H), 1.77 (m, 2H), 3.16 (s, 3H), 3.37 (dq, J=9.16 Hz, 1H), 3.52 (dq, J=8.71 Hz, 1H), 3.79 (t, J=6.87 Hz, 1H), 5.10 (d, J=12.37 Hz, 1H), 5.16 (d, J=16.95 Hz, 1H), 5.72 (dt, J=7.33 Hz, 1H). 13 C NMR (CDCl 3 ): δ 21.4, 25.5, 39.4, 49.2, 64.5, 73.9, 115.6, 140.6.
Example 25
[0087] This example illustrates the synthesis of 2-(3-methoxy-3-methylbutoxy)prop anal.
[0000]
[0088] A portion of 1-methoxy-1,1-dimethyl-3-(1-methyl prop-2-enyloxy)propane (5.75 g, 33.3 mmol) was dissolved in CH 2 Cl 2 (50 mL) and cooled to −78° C. The solution was purged with ozone for approximately one hour. Once the solution became blue, O 2 was bubbled through it for 30 minutes until the color disappeared and the reaction was quenched via addition of triphenylphosphine (10.5 g, 40.0 mmol). The solvent was removed via rotary evaporation and the resulting residue was suspend in a hexane:diethyl ether (1:1) mixture overnight in the refrigerator. The mixture was filtered and the precipitate was rinsed with hexane. The filtrate was placed on a rotary evaporator and the solvent was removed under reduced pressure. The isolated crude material was distilled via Kugelrohr apparatus (64° C., 0.40 torr) resulting in a colorless liquid (4.57 g, 78.8%). Odor: fresh, watery melon, clean, floral, muguet. GC/MS(EI): m/z(%)—174(1), 159(1), 145(1), 127(3), 113(36), 101(5), 85(24), 73(100), 69(75), 59(41), 57(14), 55(11), 45(26), 43(19), 41(22). 1 H NMR (CDCl 3 ): δ 1.17 (s, 6H), 1.27 (d, J=6.87 Hz, 3H), 1.84 (dt, J=6.42 Hz, 2H), 3.18 (s, 3H), 3.61 (m, 2H), 3.76 (dq, J=8.71 Hz, 1H), 9.64 (d, J=1.83 Hz, 1H). 13 C NMR (CDCl 3 ): δ 15.3, 25.4, 39.6, 49.3, 66.5, 73.7, 80.5, 204.0.
Example 26
[0089] This example illustrates the synthesis of 2-(3-methoxy-3-methylbutoxy)ethanal.
[0000]
[0090] A portion of the dimethyl acetal, 3-(2,2-dimethoxyethoxy)-1-methoxy-1,1-dimethylpropane (Example 1), (27.6 g, 0.13 mol) was dissolved in a large excess of neat formic acid (74.0 g, 1.61 mol) and stirred vigorously for 4 hours. Upon completion (monitored via GC), the solution was treated with H 2 O (150 mL) and extracted with ethyl acetate (3×100 mL). The organic phases were collected and dried with MgSO 4 and the solvent was removed under reduced pressure. The resulting light yellow liquid was carefully distilled via Kugelrohr apparatus first to remove any leftover formic acid (25° C., 1.00 torr) followed by isolation of the desired aldehyde (40° C., 0.10 torr) resulting in a colorless, pure liquid (13.0 g, 60.2%). Odor: fresh, melon, clean, floral, muguet, green. GC/MS(EI): m/z(%)—161(1), 145(2), 113(1), 99(6), 85(29), 73(100), 69(27), 55(9), 45(23), 43(14), 41(11). 1 H NMR (CDCl 3 ); δ 1.17 (s, 6H), 1.85 (t, J=7.33 Hz, 2H), 3.17 (s, 3H), 3.61 (t, J=7.33 Hz, 2H), 4.06 (s, 2H), 9.71 (s, 1H). 13 C NMR (CDCl 3 ): δ 25.4, 39.3, 49.3, 68.4, 73.7, 76.5, 201.0.
Example 27
[0091] This example illustrates the synthesis of 3-(3-methoxy-3-methylbutoxy)propanal.
[0000]
[0092] A portion of 3-methoxy-3-methyl-1-butanol (10.0 g, 84.6 mmol) was treated with acrolein (25.1 mL, 0.34 mol) and a small aliquot of concentrated HCl (7 drops). The solution was stirred vigorously at 40° C. in subdued light for 3 days. After this time, the solution was cooled to room temperature and ethyl acetate (75 mL) was added. The solution was washed with saturated NaHCO 3 (aq.) (100 mL) followed by H 2 O (50 mL). The organic phase was dried with MgSO 4 and the solvent was removed under reduced pressure. The resulting light yellow liquid was distilled (58° C., 0.92 torr) to yield the desired colorless aldehyde (8.21 g, 55.9%). Odor: waxy, oily, muguet, light floral. GC/MS(EI): m/z(%)—174(1), 159(1), 127(5), 85(19), 73(100), 69(7), 57(9), 55(8), 45(12), 43(11). 1 H NMR (CDCl 3 ): δ 1.14 (s, 6H), 1.76 (t, J=7.33 Hz, 2H), 2.64 (dt, J=4.12 Hz, 2H), 3.16 (s, 3H), 3.51 (t, J=7.33 Hz, 2H), 3.74 (t, J=5.96 Hz, 2H), 9.77 (t, J=2.29 Hz, 1H). 13 C NMR (CDCl 3 ): δ 25.4, 39.2, 44.0, 49.2, 64.6, 67.6, 73.8, 201.4.
Example 28
[0093] This example illustrates the synthesis of 3-(3-methoxy-3-methylbutoxy)butanal.
[0000]
[0094] This compound was synthesized employing a procedure analogous to Example 27 using 3-methoxy-3-methyl-1-butanol (10.0 g, 84.6 mmol) and crotonaldehyde (42.9 mL, 0.51 mol). The isolated crude material was fractionally distilled (48° C., 0.35 torr) resulting in a colorless liquid (3.24 g, 20.4%). Odor: waxy, oily, fatty. GC/MS(EI): m/z(%)—188(1), 173(1), 141(3), 101(5), 85(18), 73(100), 69(11), 55(7), 43(20), 41(15). 1 H NMR (CDCl 3 ): δ 1.14 (s, 6H), 1.23 (d, J=6.42 Hz, 3H), 1.74 (t, J=6.87 Hz, 2H), 2.45 (qd, J=22.91 Hz, 1H), 2.60 (qd, J=26.12 Hz, 1H), 3.17 (s, 3H), 3.43 (m, 1H), 3.60 (m, 1H), 3.93 (m, 1H), 9.77 (t, J=2.29 Hz, 1H). 13 C NMR (CDCl 3 ): δ 19.9, 25.4, 39.6, 49.2, 50.6, 64.9, 71.0, 73.8, 201.7.
Example 29
[0095] This example illustrates the synthesis of bis(3-methoxy-3-methylbutyl ethane)-1,2-dioate.
[0000]
[0096] A portion of 3-methoxy-3-methyl-1-butanol (5.00 g, 42.3 mmol) was dissolved in CH 2 Cl 2 (25 mL) and cooled to 0° C. An aliquot of oxalyl chloride (2.21 mL, 25.4 mmol) was slowly added dropwise via syringe to the vigorously stirring solution. After one hour, the solution was warmed to room temperature and washed with saturated NaHCO 3 (aq.) (2×50 mL) followed by brine solution (30 mL) and H 2 O (30 mL). The organic phase was dried with MgSO 4 and the solvent was removed under reduced pressure. The resulting clear liquid was distilled via kugelrohr apparatus (160° C., 0.15 torr) to yield the desired colorless, viscous oxalate (4.50 g, 73.3%). Odor: weak, chemical. GC/MS(EI): m/z(%)—290(1), 275(1), 257(1), 227(1), 191(1), 159(1), 101(2), 85(37), 73(100), 69(21), 55(6), 43(7), 41(9). 1 H NMR (CDCl 3 ): δ 1.19 (s, 12H), 1.91 (t, J=7.33 Hz, 4H), 3.18 (s, 6H), 4.37 (t, J=7.79 Hz, 4H). 13 C NMR (CDCl 3 ): δ 25.3, 37.9, 49.4, 63.8, 73.5, 158.0.
[0097] The below examples demonstrate the use of the fragrance formulation of Table 2 in various consumer products. These examples are illustrative only and are not intended to limit the scope of the invention in any way. Unless otherwise noted, all percentages set forth in the examples are by weight (wt). Q.S. means a sufficient quantity.
Example 30
All Purpose Cleaner—Concentrated
[0098]
[0000]
Ingredient
Supplier
Percentage
Purpose
Neodol ® 91-8
Shell
6.00
Surfactant
Dowanol ® DPnB
Dow
6.00
Solvent
Kathon ® CG
Rohm & Haas
0.10
Preservative
Fragrance of Table 2
Takasago Int'l
1.25
Fragrance
D. I. Water
—
86.65
Solvent
Dye
Pylam
Q.S.
Color
[0099] This formulation is for dilution in a bucket at approximately one part concentrate to ten parts tap water.
[0100] Procedure:
[0101] 1. The Neodol® 91-8, Dowanol® DPnB, and fragrance were mixed in a suitable vessel until completely uniform and clear.
[0102] 2. Water was added slowly with constant agitation to the solution in #1. Kathon® was added with mixing and stirring continued for 1 minute. The final formulation was clear.
[0103] 3. Dye was added match standard.
Example 31
Hard Surface Cleaner—Pump Spray
[0104]
[0000]
Ingredient
Supplier
Percentage
Purpose
Neodol ® 91-8
Shell
1.50
Surfactant
Dowanol ® DPnB
Dow
4.00
Solvent
Fragrance of Table 2
Takasago Int'l
0.40
Fragrance
Kathon ® CG
Rohm & Haas
0.07
Preservative
D. I. Water
—
94.03
Solvent
[0105] Procedure:
[0106] 1. Neodol® 91-8, Dowanol® DPnB, and fragrance were mixed in a suitable vessel until completely uniform and clear.
[0107] 2. Water was added slowly to the solution in #1 with constant agitation. The final formulation was clear. Kathon® CG was added with stirring.
[0108] The formulation was then filled into suitable plastic containers (PET preferred), with the proper trigger or pump closure.
Example 32
Liquid Laundry Detergent
[0109]
[0000]
Ingredient
INCI or Nomenclature
Percentage
Water
Water
Q.S.
Glucopon ® 625UP (1)
Alkyl Polyglucosides
12.50
Standapol ® ES-40 (1)
Alkyl Ether Sulfates
25.60
Versene ® 100 (38%) (2)
Tetrasodium EDTA
00.40
MBA (2)
Monoethanolamine
01.00
Sulfuric Acid (25% Aq.)
Acid
03.00
Sodium Chloride (25%)
Salt
01.20
Takasago Fragrance(3)
Fragrance of Table 2
00.75
100.00
[0110] Suppliers
(1) Cognis Corporation (2) The DOW Chemical Co. (3) Takasago International Corporation
Procedure:
[0114] 1. Glucopon® was added to water heated to 65° C. and mix at medium speed until clear.
[0115] 2. Standapol® was added and mixing continued until the mixture was clear and homogenous.
[0116] 3. The mixture was removed from the heat and remaining ingredients were added in order, with mixing at slow to medium speed each addition.
[0117] 4. pH was adjusted with sulfuric acid solution to pH of 8.0 to 8.5.
[0118] 5. Viscosity was adjusted with sodium chloride.
Example 33
Liquid Fabric Softener
[0119]
[0000]
Ingredient
Supplier
Percentage
Purpose
Deionized Water
—
83.50
Solvent
Rewoquat ® WE-16E
Degussa
15.00
Softener
Sodium Chloride
—
0.50
Thickening
Fragrance of Table 2
Takasago
1.00
Fragrance
[0120] Procedure:
[0121] 1. Rewoquat®, fragrance and water were mixed in a suitable vessel until the mixture was translucent to opaque.
[0122] 2. Sodium chloride was added with mixing and mixed for 5 minutes.
Example 34
Hand & Body Lotion
[0123]
[0000]
INCI or
SEQ.
INGREDIENTS
Nomenclature
PERCENT
Part 1
1
Deionized water
Water
QS
1
Versene ® 220
(1)
Tetrasodium EDTA
00.05
2
Carbopol ® 934
(2)
Carbomer 934
00.30
3
Glycerin
Glycerin
01.00
3
Propylene Glycol
Propylene Glycol
01.00
Part 2
4
Myrj ® 52S (sprayed)
(4)
PEG-40 Stearate
01.80
4
Liponate ® GC
(5)
Caprylic/Capric
13.00
Triglyceride
4
Liponate ® IPM
(5)
Isopropyl Myristate
08.50
4
Span ® 65S (sprayed)
(4)
Sorbitan Tristearate
02.00
4
Pharmalan ®, USP
(6)
Lanolin
00.50
4
White Protopet ® IS
(7)
Petrolatum
00.30
4
Propylparaben
(8)
Propylparaben
00.10
Part 3
1
Deionized Water
Water
10.00
1
TEA
Triethanolamine
00.30
Part 4
1
Deionized Water
Water
01.00
1
Unicide ® U-13
(5)
Imidazolidinyl Urea
00.25
Part 5
1
Germaben ® II
(3)
Propylene Glycol
00.70
(and) Diazo-lidinyl
Urea (and)
Methylparaben (and)
Propylparaben
Part 6
1
Takasago Fragrance
Fragrance of Table 2
QS
Oil
[0124] Suppliers:
[0125] (1) Dow Chemical
[0126] (2) Noveon
[0127] (3) Sutton/ISP
[0128] (4) Uniqema
[0129] (5) Lipo Chemicals, Inc.
[0130] (6) Croda
[0131] (7) Crompton/Witco
[0132] (8) Tri-K
[0133] Procedure:
[0134] Part 1
[0135] 1. Seq. #1 was heated to 75° C. and mixed together at medium speed using an overhead mixer until clear.
[0136] 2. Seq. #2 was added slowly to Seq. #1 with mixing. Mixing was continued until Seq. #2 is completely was hydrated. Hydration was checked by dipping a metal spatula into and out of the solution to observe if there are any gum particles that have not hydrated.
[0137] 3. Seq. #3 was added in order to the batch without heating.
[0138] Part 2
[0139] 4. Seq. #4 was premixed and heated until completely melted at approximately 65° C.
[0140] 5. Part 1 was placed on a Homomixer at low to medium speed, and Part 2 added to Part 1 and mixed for 1 minute.
[0141] 6. The batch was placed back onto the overhead mixer at medium speed and premixed Part 3 was added without heating to the batch for approximately 2 minutes.
[0142] 7. Mix was continued at low speed and the mixture was cooled to 35° C.
[0143] 8. Part 4 was premixed at 35° C. and added to the batch, while cooling down at low speed to 30° C.
[0144] 9. Part 5 was added at 30° C. with mixing at low speed.
[0145] Liquid fragrance was added slowly while mixing.
[0146] 10. Lotion was placed in jars and allowed to at room temperature for 24 hours.
Example 35
Clear Liquid Hand Soap
[0147]
[0000]
SEQ.
INGREDIENTS
INCI
PERCENT
1
Deionized water
Water
66.50
1
Methyl Paraben
(1)
Methyl Paraben
00.25
2
Liponic ® EG-1
(2)
Glycereth-26
01.00
2
Glycerin
(3)
Glycerin
01.00
2
Lipopeg ® 6000DS
(2)
PEG-150 Distearate
00.50
3
Monamid ® 716
(4)
Lauramide DEA
03.50
3
Standapol ® ES-2
(3)
Sodium Laureth
25.00
Sulfate
3
Velvetex ® BK-35
(3)
Cocamidopropyl
15.00
Betaine
4
Deionized Water
Water
01.00
4
Unicide ® U-13
(2)
Imidazolidinyl Urea
00.25
5
Fragrance as defined
00.50
in Table 2 above
6
Citric acid (25%
QS
Solution)
[0148] Suppliers:
[0149] (1) TRI-K
[0150] (2) Lipo Chemicals, Inc.
[0151] (3) Cognis/Henkel
[0152] (4) Uniqema
[0153] Procedure:
[0154] 1. The methyl paraben was added slowly to the DI water heated to 65° C. with mixing at medium/high speed using an overhead mixer until completely into solution and clear. (Seq.#1)
[0155] 2. Seq. #2 was added to Sequence #1 at low speed until completely clear.
[0156] 3. Seq. #3 was added to batch without heating, in order of addition, and cooled down to 35° C. with low agitation.
[0157] 4. Seq. #4 was premixed until clear, and added to batch.
[0158] 5. Seq. #5 was added to the batch with low agitation and cooled down to 25° C.
[0159] 6. Seq. #6 was added to adjust batch to desired pH. The product was placed in jars, pouring very slowly onto the sides of the jars to eliminate any additional aeration. pH=adjust to: 6.64+/−0.2; viscosity=18,640 cps (+/−10%) with Brookfield LV Sp. #4 @ 30 rpm
Example 36
Clear Shampoo
[0160]
[0000]
SEQ.
INGREDIENTS
INCI
PERCENT
1
Deionized water
Water
Q.S.
2
Versene ® 220
(1)
Teterasodium EDTA
00.05
3
Methocel ® E4M
(2)
Hydroxypropyl
00.30
(*prep)
Methylcellulose
4
Standapol ® T
(3)
TEA Lauryl Sulfate
18.00
4
Standapol ® A
(3)
Ammonium Lauryl Sulfate
08.00
4
Monamid ®
(4)
Lauramide DEA
04.00
150-LMWC
4
Palmitic Acid
(5)
Palmitic Acid
00.30
5
Glydant ® 2000
(6)
DMDM Hydantoin
00.15
5
Sodium Chloride,
(7)
Sodium hloride
00.34
Granular
5
Citric Acid
(8)
Citric Acid
00.43
6
Takasago perfume
(9)
Fragrance of Table 2
Q.S.
oil
[0161] Suppliers:
[0162] (1) AND
[0163] (2) DOW CHEMICAL CO.
[0164] (3) COGNIS/HENKEL
[0165] (4) UNIQEMA
[0166] (5) Takasago International Corp (TIC), USA
[0167] (6) LONZA
[0168] (7) FISHER SCIENTIFIC
[0169] (8) TIC, USA
[0170] (9) TIC, USA
[0171] Procedure:1. ⅓ of Seq.#1 and Seq.#2 was heated to 85° C. Methocel powder was by mixing thoroughly using ⅕ to ⅓ of the required total amount of water as hot water (80-90° C.). Mixing was continued with overhead mixer at medium speed until all of the particles were wetted down, and a consistent dispersion was obtained. The remainder of the water containing Seq. #2 was added as cold water while mixing. The solution was cooled down to less than 30° C. Mixing was continued after the proper temperature was achieved for approximately 20 minutes. After preparation was completed, the Methocel® solution was reheated to 60° C.
[0172] 2. Seq.#4 at 60 to 65° C. was added slowly to the batch in order of addition with mixing continued at low speed.
[0173] 3. Seq.#5 was added slowly to batch and mixing continued at low speed until room temperature was reached. Citric acid was added to a pH of 5.5-6.0 and sodium chloride was added to achieve the desired viscosity. Fragrance Seq.#6 was weighed and added to the formulation while mixing.
[0174] 4. Viscosity: =2020 cps. (±10%) taken at 20° C., (Brookfield LV Sp.#3 @ 12 rpm), pH=5.5 (+/−0.5)
[0175] The below examples demonstrate the use of the materials claimed in flavor formulations in various consumer products. These examples are illustrative only and are not intended to limit the scope of the invention in any way. In these examples, all % are % (wt), unless otherwise noted and Q.S. means a sufficient quantity.
Example 37
Tooth Paste
[0176] Toothpaste with flavor and the claimed compound(s) was prepared according to the formulation below.
[0000]
Components
WT %
2-(3-methoxy-3-methylbutoxy)ethanal
0.50
[Compound 23; TABLE 1]
Calcium hydrogen phosphate (dihydrate)
50.00
Glycerin
25.00
Sodium lauryl sulfate
1.40
Carboxymethyl cellulose sodium salt
1.50
Saccharin sodium salt
0.20
Sodium benzoate
0.10
Strawberry type flavor
0.70
Purified water balance
qs
Total 100.00
Example 38
Peach Flavor
[0177] Peach flavor utilizing the claimed compound(s) was prepared according to the formulation below utilizing the claimed compounds.
[0000]
Components
WT %
2-(3-methoxy-3-methylbutoxy)ethanal
0.20
[Compound 23; TABLE 1]
Benzaldehyde
0.20
methyl cyclohexyl)ethanone
0.30
Ethyl acetate
2.0
Ethyl butyrate
0.8
Ethyl maltol
0.3
γ-Undecalactone
0.5
Linalool
0.5
Peach flavor base
5.0
Ethyl alcohol balance
q.s.
Total 100.00
Example 39
Green Tea Flavor
[0178] Green tea flavor was prepared according to the formulation below utilizing the claimed compound(s)
[0000]
Components
WT %
Benzyl alcohol
1.0
2-(3-methoxy-3-methylbutoxy)ethanal
0.3
[Compound 23; TABLE 1]
Cis-3-hexenol
0.3
Dimethyl sulfide
0.1
Geraniol
0.6
1-menthol
2.5
Linalool
0.9
Nerolidol
0.2
Terpineol
0.2
Green tea base
5.0
Ethyl alcohol balance
qs
Total 100.00
Example 40
Black Tea Flavor
[0179] Black tea flavor was prepared according to the formula below utilizing the claimed compounds.
[0000]
Components
WT %
α-Ionone
0.2
α-Ionone
0.2
Benzaldehyde
1.0
2-(3-methoxy-3-methylbutoxy)ethanal
1.0
[Compound 23; TABLE 1]
Cis-3-hexenol
6.0
δ-Decalactone
2.5
δ-Dodecalactone
2.0
Damascenone
0.1
Linalool
3.5
Geraniol
6.0
Citral
1.0
Linalool oxide
1.6
Methyl salicylate
2.0
Phenylethyl alcohol
6.0
Hexyl aldehyde
1.0
Propylene glycol balance
qs
Total 100.00 | The present invention is related to substituted butanol derivatives of the formula:
wherein R is an unsubstituted or substituted C 1-6 straight chain alkyl, an unsubstituted or substituted C 3-6 branched chain alkyl, an unsubstituted or substituted C 3-6 straight chain alkenyl, an unsubstituted or substituted C 3-6 branched chain alkenyl, an unsubstituted or substituted C 3-6 cycloalkyl, an unsubstituted or substituted C 1-6 alkoxy, nitrile, halo, amino, an unsubstituted or substituted C 1-6 alkylamino, an unsubstituted or substituted C 1-6 dialkylamino, carboxy-C 1-6 alkylamino, carboxy-C 1-6 dialkylamino, an unsubstituted or substituted acetoxy, carboxy, an unsubstituted or substituted carboxyethyl, an unsubstituted or substituted C 1-6 alkylcarbonyl, an unsubstituted or substituted C 1-6 alkylcarboxy, an unsubstituted or substituted C 1-6 alkylthio, an unsubstituted or substituted C 1-6 alkyloxy, carboxamido, an unsubstituted or substituted C 1-6 alkylcarboxamido or an unsubstituted or substituted C 1-6 dialkylcarboxamido. Such compounds are useful in flavor or flavor compositions. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a semiconductor device, and more particularly relates to a semiconductor device with a termination resistance adjusting circuit for adjusting a termination resistor.
2. Description of the Related Art
A technique is conventionally known in which a termination resistor is built in a semiconductor device in order to attain cost-down of a transmission system and reduction of a substrate mounting area. When the termination resistor built in the semiconductor device is not adjusted, there may be a high possibility that the resistance of the termination resistor has a wide distribution due to manufacturing variation of the termination resistor. If the resistance of the termination resistor is out of a desired range, signal reflection is caused to deteriorate transmission quality, which results in the decrease in a production yield. Also, the resistance of the termination resistor is a factor to determine an output signal voltage of a transmitting circuit in the transmission system. Therefore, stabilization of both the resistance of the termination resistor and the output signal voltage is required.
Conventional techniques are known in Japanese Laid Open Patent Application (JP-P2003-298395A and JP-P2004-32721A: first and second conventional examples), in which a resistance adjusting circuit is built in a semiconductor device to operate a circuit adequately even if the resistance of a termination resistor is out of a desired range.
FIG. 1 is a block diagram showing the configuration of a termination resistance adjusting circuit 100 in the first conventional example. In the first conventional example, a stable reference current Iref is generated based on reference voltages VrefH and VrefL and an external resistance 119 and is applied to a replica resistor 130 . Voltages Va and Vb generated at that time, and the reference voltages VrefH and VrefL are compared by a control voltage generator 120 . Thus, the control voltage generator 120 recognizes the difference between the replica resistor 130 and the external resistance 119 from the comparison result and carries out an adjustment so that the resistance of the replica resistor 130 and that of the external resistance 119 are coincident with each other.
Also, FIG. 2 is a block diagram showing the configuration of an impedance variable circuit 200 in the second conventional example. In the impedance variable circuit shown in FIG. 2 , a synthetic resistance of resistors ( 201 to 209 ) is varied by controlling switches (SW 1 to SW 9 ) and is used as a termination resistor.
FIG. 3 is a circuit diagram showing a specific circuit configuration of a termination resistance adjusting circuit 300 , which is constituted from the above-mentioned termination resistance adjusting circuit 100 and the impedance variable circuit 200 . As shown in FIG. 3 , the termination resistance adjusting circuit 300 is composed of a termination resistor generator 101 , a transmitting circuit 102 , a first reference current generator 104 , a second reference current generator 105 and a termination resistance controller 106 . In the termination resistance adjusting circuit 300 , the first reference current generator 104 generates a stable reference current Iref 1 based on a reference voltage Vref and an external resistance 109 , and applies the reference current Iref 1 to a replica resistor 130 of the termination resistance controller 106 . Also, the second reference current generator 105 generates a stable reference current Iref 4 based on a reference voltage Vref and an internal resistance 108 , and applies the reference current Iref 4 to a replica resistor 131 of the termination resistance controller 106 . The termination resistance controller 106 compares a voltage V 1 generated based on the current Iref 1 and the resistor 130 and a voltage V 2 generated based on the current Iref 4 and the resistor 131 , and recognizes the difference between the internal resistance 108 and the external resistance 109 from the comparing result. Then, the termination resistance controller 106 outputs a control signal Vcont to the termination resistor generator 101 based on the comparing result. The termination resistor generator 101 generates a resistance through separation and synthesis of resistors in response to the control signal Vcont, such that a precision of the internal resistance is coincident with that of the external resistance.
When the termination resistor is assumed to be a resistor value R 150 and the reference current is assumed to be a reference current Iref 2 , a transmitting circuit output voltage Vo is represented by:
Vo=R 150* I ref2 (1)
In the conventional termination resistance adjusting circuit 300 shown in FIG. 3 , the voltages V 1 and V 2 are compared. The voltage V 2 is generated when the current Iref 4 is applied to the resistor 131 . The current Iref 4 is generated based on a reference voltage Vref and the internal resistance 108 . The reference voltage Vref is supplied from a band gap power supply circuit or the like, in which an output voltage variation caused due to external factors such as a temperature variation, a power source voltage variation and the like is small.
The voltage V 1 is generated when the current Iref 1 is applied to the resistor 130 . The current Iref 1 is generated based on the reference voltage Vref and the external resistance 109 which is more stable than the internal resistance in an absolute precision. The reference voltage Vref is supplied from the above-mentioned band gap power supply circuit or the like.
Here, when the internal resistances 108 and 131 are assumed to be R 108 and R 131 , respectively, and the external resistance 109 and the internal resistance 130 are similarly assumed to be R 109 and R 130 , respectively, the voltages V 1 and V 2 are represented by the following equations.
V 2=( V ref/ R 108)* R 131 (2)
V 1=( V ref/ R 109)* R 130 (3)
In this case, since the internal resistances 131 and 108 have the same structure, the relative precision is insured. Therefore, the item of “R 131 /R 108 ” in the above equation (2) has a constant value. Thus, the voltage V 2 is the stable voltage similar to the reference voltage Vref.
Also, since the external resistance 109 has an extremely high precision as compared with the internal resistance, the item of “Vref/R 109 ” in the above equation (3) can be regarded as a constant value. Thus, the voltage V 1 is a value proportional to the internal resistance 130 . FIG. 4 shows the above relation. When the voltages V 1 and V 2 are compared, if the voltage V 1 is determined to be excessively higher than the voltage V 2 (namely, the internal resistance is excessively high), the control signal Vcont is outputted to adjust the resistance R 150 to a low value. Consequently, the precision of the termination resistor 150 after the adjustment is similar to that of the external resistance 109 .
However, the actual adjustment is carried out in a step manner of a definite range. Thus, even in the ideally adjusted state, the resistances before and after the adjustment are discontinuous, which brings about an error depending on the adjustment resolution of the termination resistor 150 . In particular, it could be understood that the maximum error (ERR) is generated in the vicinity of the adjustment.
Under the assumption that the termination resistor has been adjusted, a fixed current Iref 2 is generated based on the stable power voltage Vref and the external resistance 109 and applied to the transmitting circuit 102 . Thus, the transmitting circuit output voltage Vo is a function of the termination resistor 150 , as represented by the following equation (4).
Vo=I ref2* R 150 (4)
FIG. 5 is a diagram showing the waveform of an output signal outputted from the termination resistance adjusting circuit 300 . With reference to the waveform shown in FIG. 5 , the voltage error +ERR, −ERR remains in the output signal waveform due to the adjustment error of the termination resistor 150 . The voltage error +ERR, −ERR sometimes causes poor measurement reproducibility or a large deviation of the output voltage of the transmitting circuit 102 .
In order to avoid these problems, a method is known in which the adjustment resolution is made higher. However, if such a method is employed, the higher precision of the termination resistance controller 106 is required, which leads to a larger circuit scale. Also, since the number of switching circuits in the termination resistor generator 101 is increased, a capacitive load becomes greater, which restricts a frequency band.
The termination resistance adjusting circuit is desired in which the adjustment error to the termination resistor has no influence on the output voltage, without the increase in the circuit scale and the limitation on the frequency band.
SUMMARY OF THE INVENTION
In an aspect of the present invention, a semiconductor device includes a transmitter, a termination resistance adjusting section, a transmitter control section and a control signal generating section. The transmitter has two output terminals and operates based on a control current. The termination resistance adjusting section is connected with the output terminals of the transmitter and applies a termination resistance adjusted in response to a control signal to each of the output terminals of the transmitter. The transmitter control section supplies the control current to the transmitter in response the control signal. The control signal generating section compares a first voltage corresponding to an external resistance and a second voltage corresponding to an internal resistance whose precision is lower than that of the external resistance, and outputs the control signal to the termination resistance adjusting section and the transmitter control section based on the comparing result.
Here, the control signal generating section may include a first reference current generating section which generates a first reference current corresponding to the external resistance, a second reference current generating section which generates a second reference current corresponding to the internal resistance, and a termination resistor control section. The termination resistor control section generates the first voltage and the second voltage based on the first reference current and the second reference current, respectively, and supplies the control signal to the termination resistance adjusting section and the transmitter control section by comparing the first and second voltages.
Also, the transmitter control section may include a reference resistance adjusting section configured to apply a reference resistance corresponding to the termination resistor in response to the control signal, and a control current generating section configured to generate and supply the control current corresponding to the reference resistance to the transmitter.
In this case, the reference resistance adjusting section may include a reference basic resistor, a reference adjustment resistor, and a reference switch circuit configured to connect the reference adjustment resistor with the reference basic resistor in parallel in response to the control signal. Also, the control current generating section may include an amplifier having a positive input connected with a first reference voltage, a first transistor having a gate connected with an output of the amplifier, and a source connected with the reference resistance adjusting section and a negative input of the amplifier, and a current mirror circuit connected with a drain of the first transistor, and to supply the control current as an output current to the transmitter.
Also, the termination resistance adjusting section may include a basic resistor provided for each of the output terminals of the transmitter, a adjustment resistor provided for each of the output terminals of the transmitter, and a switch circuit configured to connect the adjustment resistor with the basic resistor in parallel in response to the control signal.
Also, it is preferable that a ratio of a resistance of the reference basic resistor and a resistance of the reference adjustment resistor is equal to a ratio of a resistance of the basic resistor and a resistance of the adjustment resistor.
Also, the transmitter may include a differential transistor pair configured to drive the output terminals of the transmitter, and a constant current source connected with the differential transistor pair, and configured to supply the differential transistor pair with a constant current determined based on the control current. Instead, the transmitter may include a differential transistor pair configured to drive the output terminals of the transmitter. The control current is supplied as a constant current for the differential transistor pair.
In another aspect of the present invention, a method of adjusting a transmitter in a semiconductor device is achieved by generating a control signal based on an external resistance and an internal resistance built in the semiconductor device, wherein a precision of the external resistance higher than that of the internal resistance; by adjusting load resistances of differential transistor pair as termination resistors in response to the control signal; and by adjusting a constant current for the differential transistor pair in response to the control signal.
The generating a control signal may be achieved by generating a first reference current corresponding to the external resistance; by generating a second reference current corresponding to the internal resistance; by generating a first voltage and a second voltage based on the first reference current and the second reference current, respectively; and by comparing the first and second voltages to generate the control signal.
Also, the adjusting load resistances of differential transistor pair may be achieved by connecting an adjustment resistor with a basic resistor in parallel in response to the control signal.
Also, the adjusting a constant current may be achieved by adjusting a reference resistance corresponding to the termination resistors in response to the control signal; and by supplying the control current corresponding to the reference resistance to the differential transistor pair.
In this case, the adjusting a reference resistance may be achieved by connecting a reference adjustment resistor with a reference basic resistor in parallel in response to the control signal to generate the reference resistance.
Also, the supplying the control current may be achieved by controlling a current flowing through the reference resistance based on a reference voltage; and by supplying as the control current a current corresponding to the current flowing through the reference resistance to the differential transistor pair by a mirror circuit.
Also, a ratio of a resistance of the reference basic resistor and a resistance of the reference adjustment resistor is equal to a ratio of a resistance of the basic resistor and a resistance of the adjustment resistor.
In another aspect of the present invention, a semiconductor device includes a transmitter having a differential transistor pair, a control section configured to generate a control signal based on an external resistance and an internal resistance built in the semiconductor device, wherein a precision of the external resistance higher than that of the internal resistance; a termination resistance adjusting section configured to adjust load resistances of the differential transistor pair as termination resistors in response to the control signal; and a transmitter control section configured to control a constant current for the differential transistor pair in response to the control signal.
Here, the transmitter control section may include a reference resistance adjusting section configured to adjust a reference resistance corresponding to the termination resistors in response to the control signal; and a supplying section configured to supply the control current corresponding to the reference resistance to the differential transistor pair.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a configuration of a termination resistance adjusting circuit in a first conventional example;
FIG. 2 is a circuit diagram showing a configuration of an impedance variable circuit in a second conventional example;
FIG. 3 is a circuit diagram showing a configuration of the termination resistance adjusting circuit when the second conventional example is applied to the first conventional example;
FIG. 4 is a waveform diagram showing an operation of the conventional termination resistance adjusting circuit shown in FIG. 3 ;
FIG. 5 is a diagram showing the waveform of an output signal from a transmitting circuit in the conventional termination resistance adjusting circuit shown in FIG. 3 ;
FIG. 6 is a circuit diagram showing a configuration of a termination resistance adjusting circuit in an embodiment of the present invention;
FIG. 7 is a circuit diagram showing a configuration of a transmitting circuit in the embodiment of the present invention;
FIG. 8 is a diagram showing signal waveforms in an operation of the termination resistance adjusting circuit according to the embodiment of the present invention; and
FIG. 9 is a diagram showing the waveform of an output signal from the transmitting circuit in the termination resistance adjusting circuit according to the embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, a semiconductor device with a termination resistance adjusting circuit of the present invention will be described in detail with reference to the attached drawings.
FIG. 6 is a circuit diagram showing the configuration of the termination resistance adjusting circuit 10 in the embodiment of the present invention. As shown in FIG. 6 , the termination resistance adjusting circuit 10 is provided with a termination resistor generator 1 , a reference current corrector 3 , a first reference current generator 4 , a second reference current generator 5 and a termination resistance controller 6 . The reference current corrector 3 includes a reference resistance generator 7 and a reference current generator 8 .
The first reference current generator 4 generates a reference current Iref 1 based on a reference voltage Vref and an external reference resistor 19 . The first reference current generator 4 supplies the generated reference current Iref 1 to the termination resistance controller 6 . Similarly, the second reference current generator 5 generates a current Iref 4 based on the reference voltage Vref and an internal reference resistor 18 . The second reference current generator 5 supplies the generated reference current Iref 4 to the termination resistance controller 6 , as well as to the first reference current generator 4 . The termination resistance controller 6 applies the reference current Iref 1 to an internal resistance 20 . Consequently, a voltage of a node N 1 becomes a voltage V 1 , and the voltage V 1 is applied to a control signal generating circuit 61 . Similarly, the termination resistance controller 6 applies the reference current Iref 4 to an internal resistance 21 . Consequently, a voltage of a node N 2 becomes a voltage V 2 , and the voltage V 2 is applied to the control signal generating circuit 61 . The control signal generating circuit 61 compares the voltages V 1 and V 2 . The termination resistance controller 6 outputs the comparison result as a control signal Vcont to the termination resistor generator 1 and the reference current corrector 3 . The termination resistor generator 1 receives the control signal Vcont and adjusts a termination resistor 11 and a termination resistor 14 . In the following explanation, since the configuration and operation of the termination resistor 14 are similar to those of the termination resistor 11 , the termination resistor 11 is mainly explained.
The reference resistance generator 7 receives the control signal Vcont from the termination resistance controller 6 , adjusts the resistance of a reference resistor 71 to a resistance R 51 . The reference current generator 8 generates a reference current Iref 3 , which is obtained by applying a reference voltage Vref 2 to the adjusted resistor value R 51 , and supplies the reference current Iref 3 to the transmitting circuit 2 . The reference resistance generator 7 includes a reference resistor 71 , and the reference resistor 71 is composed of a basic resistor 73 and an adjustment resistor 72 to be connected in parallel to the basic resistor 73 . As shown in FIG. 6 , the adjustment resistor 72 is connected to a switch circuit S 1 . The switch circuit S 1 is operated in response to the control signal Vcont outputted from the termination resistance controller 6 . Preferably, the switch circuit S 1 , basic resistor 73 and adjustment resistor 72 , which constitute the reference resistance generator 7 , have the same structures as those constituting the termination resistor generator 1 , so as to be matched with the termination resistor generator 1 .
The reference current generator 8 includes an operational amplifier OP 1 , a transistor MP 1 , a transistor MN 1 and a transistor MN 2 . As shown in FIG. 6 , a gate of the transistor MP 1 is connected to an output end of the operational amplifier OP 1 . A source of the transistor MP 1 is connected to the reference resistance generator 7 . Also, the source of the transistor MP 1 is connected to a negative feedback input terminal of the operational amplifier OP 1 . The transistor MN 1 and the transistor MN 2 constitute a current mirror circuit. A drain of the transistor MP 1 is connected to the gate and drain of the transistor MN 1 . In the reference current generator 8 , the output of this current mirror acts as an output terminal.
FIG. 7 is a circuit diagram showing the configuration of the transmitting circuit 2 in the embodiment of the present invention. As shown in FIG. 7 , the transmitting circuit 2 is composed of a differential transistor pair. The adjusted termination resistors 14 and 11 function as load resistances of the differential transistor pair. In this embodiment, a constant current for the differential transistor pair is supplied as the reference current Iref 3 from the current mirror circuit of the reference current generator 8 . Although not showing, a constant current source may be separately provided and may supply a constant current to the differential transistor pair based on the reference current Iref 3 . When the resistance of the termination resistor 11 is assumed to be a resistance R 50 and the reference current Iref 3 is used, a transmission output level Vo of the transmitting circuit 2 is represented by:
Vo=R 50* I ref3
from FIG. 9 .
The first reference current generator 4 has a stabilized band gap power supply or the like, and generates the reference current Iref 1 by applying a voltage Vref from the stabilized power supply to the external internal resistance R 19 . Also, the second reference current generator 5 has a stabilized band gap power supply similar to that of the first reference current generator 4 , and generates the reference current Iref 4 by applying the voltage Vref from the stabilized band gap power supply to the internal resistance 18 which is expected to have the same value as the external resistance R 19 . Thus, the reference current Iref 1 and the reference current Iref 4 can be represented by the following equations:
I ref1= V ref/ R 19
I ref4= V ref/ R 18
The generated reference current Iref 1 is applied to the internal resistance 20 , and the reference current Iref 4 is applied to the internal resistance 21 . The termination resistance controller 6 compares the voltage V 1 generated by the internal resistance 20 and the voltage V 2 generated by the internal resistance 21 . The voltages V 1 and V 2 can be represented by the following equations:
V 1= I ref1* R 20= V ref/ R 19* R 20 (5)
V 2= I ref4* R 21= V ref/ R 18* R 21 (6)
The termination resistor generator 1 receives the control signal Vcont outputted from the termination resistance controller 6 and drives the switch circuit. Since the switch circuit is turned on, the basic resistor 13 and an adjustment resistor 12 are connected in parallel. When the resistance of the adjustment resistor 12 is assumed to be a resistance R 12 and when the resistance of the basic resistor 13 is assumed to be a resistance R 13 , its synthesized resistance R 50 is changed as follows:
R 50= R 13* R 12/( R 13+ R 12) (7)
Here, the reference resistance generator 7 similarly receives the control signal Vcont outputted from the termination resistance controller 6 and drives the switch circuit. Since the switch circuit is turned on, the basic resistor 73 and the adjustment resistor 72 are connected in parallel. When the resistance of the basic resistor 73 is assumed to be a resistor value R 73 and when the resistance of the adjustment resistor 72 is assumed to be a resistor value R 72 , its synthesized resistor value R 51 is changed as follows:
R 51= R 73* R 72/( R 73+ R 72) (8)
The reference current generator 8 applies the reference voltage Vref 2 to the reference resistor value R 51 provided by the reference resistance generator 7 and generates the reference current Iref 3 . The reference current generator 8 supplies the current Iref 3 to the transmitting circuit. If the reference resistor value R 51 is adjusted, the reference current Iref 3 is also corrected at the same time. FIG. 8 is a diagram showing an operational of the termination resistance adjusting circuit 10 in this embodiment. As shown in FIG. 8 , the operation waveform of the reference current Iref 3 has a relation between the reference resistor R 51 and the termination resistor R 50 , and it can be represented by the following equation:
I ref3= V ref2/ R 51
For this reason, the output signal voltage Vo of the transmitting circuit 2 is represented by a product of the reference current Iref 3 and the resistance R 50 of the termination resistor 11 , and it is represented by the following equation:
Vo=I ref3* R 50= V ref2* R 50/ R 51 (9)
At this time, the termination resistor generator 1 and the reference resistance generator 7 are adjusted at the same time. As a result, the ratio between the resistance R 12 of the adjustment resistor 12 and the resistance R 13 of the basic resistor 13 , and the resistance R 73 of the basic resistor 73 and the resistance R 72 of the adjustment resistor 72 is set as follows:
R 13: R 12= R 73: R 72
Since the respective resistances are set as mentioned above, the following relation is always established between the synthesized resistance R 50 expressed by the equation (7) and the synthesized resistance R 51 expressed by the equation (8):
R 50∝ R 51
At this time, the item of “R 50 /R 51 ” in the equation (9) becomes a constant value in the meaning. Thus, the output voltage can be represented as a function that does not contain a term depending on a resistance, as follows:
Vo∝V ref2
FIG. 9 is a diagram showing the output waveform of the transmitting circuit when the termination resistance adjusting circuit in the embodiment of the present invention is employed. With reference to FIG. 9 , the output signal voltage Vo is outputted as a constant value. This implies that the constant output signal voltage Vo is obtained irrespectively of the controlled state of the internal resistance R 51 .
As described above, according to the present invention, it is possible to design the termination resistance adjusting circuit in which the adjustment error due to the resistance of the termination resistor has no influence on the output voltage. | A semiconductor device includes a transmitter, a termination resistance adjusting section, a transmitter control section and a control signal generating section. The transmitter has two output terminals and operates based on a control current. The termination resistance adjusting section is connected with the output terminals of the transmitter and applies a termination resistance adjusted in response to a control signal to each of the output terminals of the transmitter. The transmitter control section supplies the control current to the transmitter in response the control signal. The control signal generating section compares a first voltage corresponding to an external resistance and a second voltage corresponding to an internal resistance whose precision is lower than that of the external resistance, and outputs the control signal to the termination resistance adjusting section and the transmitter control section based on the comparing result. | 7 |
TECHNICAL FIELD
This invention relates to vehicle dehumidifying mechanisms in general, and specifically to such a system with an improved thermal and air flow efficiency.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 5,509,275 issued Apr. 23, 1996 to Bhatti, et al., and co-assigned to the assignee of the subject invention, discloses a system for continually dehumidifying ambient air that is drawn into a heating, ventilating and air conditioning (HVAC) system of a motor vehicle. Typically, hot air which is also quite humid is simply pulled directly in and forced over a cold evaporator core, which cools the air as well as condensing water out of the air. While drier air enters the passenger cabin, relying upon condensation by the evaporator core brings its own problems, especially microbial growth and its attendant odor. The patent noted provides a desiccant wheel of novel design that continually turns, at slow speed, within the HVAC housing, removing moisture in desiccant lined tubes in an adsorption half of the wheel, which are regenerated in a heated half of the wheel through which hot air is forced. The two “halves” of the wheel are defined by stationary rubbing seals. The tubes run axially from face to face of the wheel, but are not tightly packed, leaving space between for a radial cross flow of outside air that is blown over the outside of the tubes, in both halves of the wheel. The radial cross flow cools the tubes in the adsorption half of the wheel, removing the latent heat released by the desiccant when it adsorbs moisture. The cooling of the tubes in the adsorption half of the wheel is beneficial, since the heat released by the working desiccant is thereby prevented from reaching the evaporator core.
However, the same cross flow, when it crosses the other half of the wheel, is cooler than the heated air simultaneously passing through the inside of the tubes to regenerate the desiccant. Therefore, the cross flow air can potentially reduce the efficiency of the concurrent regeneration process as it passes through the other half of the wheel. In addition, much of the limited volume of the wheel is the empty space necessarily left between the tubes. Since space is at a premium in any HVAC housing, more complete utilization of the volume within the wheel would be desirable.
SUMMARY OF THE INVENTION
The subject invention discloses a more space efficient desiccant wheel that provides maximum utilization of the space within the wheel, combined with a novel system of ducts and seals that confines the radial cross cooling flow only to that half of the wheel where it is most beneficial.
In the preferred embodiment disclosed, the entire internal volume of the wheel, defined between a pair of axially spaced, annular end faces and a concentric outer cylindrical wall and central inner tunnel, is occupied by a closely packed array of evenly circumferentially spaced cells. Each cell is comprised of a pair of solid conductive metal leaves, separated by a constant thickness in a spiral pattern radiating from the central tunnel to the outer wall. A first set of cells, including every other cell contains a constant thickness, corrugated conductive metal fin, with axially oriented corrugations that run the entire axial length of the cell, from end face to end face. The cells in the first set are also axially open at each end face, but radially blocked throughout, because of the orientation of the fin corrugations. Therefore, in the first set of cells there is a potential axial flow path through, but not radial. A second set of cells, including those cells intermediate the first set, contains similar fins, with the same thickness and orientation, but with the axial end of each fin cut off at an angle to provide diagonally and radially opposed openings through the outer wall and central inner tunnel. Each cell of the second set of cells is deliberately blocked at both annular end faces, however. Therefore, in the second set of cells, there is a potential radial flow path from outer wall to inner tunnel (a compound radial and axial flow path), but no axial flow path from end face to end face. The fins in the first set of cells are desiccant coated, while those in the second set of cells are not, and all fins are tightly engaged with the leaves separating the individual cells, so as to provide efficient heat conductive paths through the adjacent cells that are otherwise sealed from one another in terms of potential air flow. In effect, all possible space within the wheel is taken up by cell spaces and their contained fins.
Within the HVAC system and housing, a novel system of ducts and seals directs various air flows through selected cells with maximum thermal efficiency, taking best advantage of the improved space efficiency of the wheel itself. Stationary rubbing seals against the faces of the wheel divide the wheel space enveloped into two basic halves that are also stationary, an adsorption half and a regeneration half, as with the previously patented design noted above. As the wheel slowly turns, cells from each set of cells turn through each half of the space successively and repeatedly. Humid outside air is directed through an outside air feed duct at a front end face of the wheel within the adsorption half of the divided space envelope. Since cells in the second set are axially blocked, humid air flows axially through only cells in the first set, passing axially over their desiccant coated fins. Moisture is adsorbed, and the latent heat released is conducted by the same fins across shared leaves and into adjacent cells in the second set.
Concurrently, outside air (or air at a similar ambient temperature) is fed radially through a feed manifold to the outer wall of the wheel, within the adsorption half of the envelope, and radially enters only cells from the second set (since cells in the first set are radially blocked). The cross flow of air flows radially through and axially across the fins of those cells of the second set of cells located within the adsorption half of the envelope, removing the released heat of adsorption conducted from adjacent cells. Because of the design of the wheel, all available volume within the adsorption half of the envelope is occupied either by cells involved in moisture adsorption, or cells involved in heat removal, with no dead or wasted space. Cross flow air in the adsorption half of the envelope eventually exits its cells into the central tunnel, which is axially blocked by a cap at the front end face. A semi-cylindrical, stationary rubbing seal blocks those radial openings in the central tunnel located in the regeneration half of the envelope. The capped tunnel and the semi-cylindrical seal together create a radial cross flow exhaust duct that directs the cross flow axially out and away from the wheel at the back face, preventing it from radially entering those cells of the second set located in the regeneration half of the envelope.
Also, concurrently, externally heated air is directed through a regeneration duct to the back end face of the wheel on the regeneration half of the space envelope, flowing axially only through those cells of the first set located in the regeneration half (since, again, cells of the second set are axially blocked). The heated air dries and regenerates the desiccant in the cells of the first set, without being cooled by any cross flow air in adjacent cells of the second set, improving the efficiency of operation. Regeneration air with moisture driven out of the desiccant is then axially exhausted away from the front face of the wheel. In addition, in the embodiment disclosed, the radial cross flow air that is exhausted from the central tunnel at the back face of the envelope tunnel is captured and used as pre heated entry air for the regeneration duct and its heater, so that the removed heat of adsorption is not wasted.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will appear from the following written description, and from the drawings, in which:
FIG. 1 is a schematic view of an HVAC system incorporating the desiccant wheel and associated duct work of the invention;
FIG. 2 is a schematic perspective of a space envelope occupied by the desiccant wheel of the invention, showing how it is divided into two basic halves;
FIG. 3 is perspective view of the desiccant wheel alone;
FIG. 4 is a perspective view of several individual cells of the wheel, showing the concurrent axial and radial air flows by arrows; and
FIG. 5 is an exploded perspective view of the wheel and its associated ducts and seals, also showing the concurrent air flows by arrows.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, a vehicle heating, ventilation and air conditioning system, indicated generally at 10 , includes several standard components and structures. A large hollow housing 12 contains a standard evaporator core 14 and heater core 16 , through which a temperature door directs some, all, or none of the cooled air that has passed through evaporator core 14 . Outside air at ambient temperature and humidity is forcibly drawn into housing 12 through inlet 18 by a standard main blower 20 . Rather than being sent over the evaporator core 14 directly, as is standard, the ambient air is first dried by the dehumidifying system of the invention, which includes a wheel, indicated general at 22 , and an associated series of ducts, seals and other components, described in detail later. The details of wheel 22 are described first.
Referring next to FIG. 2, wheel 22 is most easily conceptualized as having a central axis, shown by the dotted line X, and occupying a space envelope arrayed around axis X defined by a front annular end face F, a back annular end face B, an interior tunnel T, and a concentric outer cylindrical wall O. These represent imaginary boundaries, rather than structures, per se, but the wheel 22 can be considered to have equivalent structures, since it fits closely within the same envelope. The space envelope may also be conveniently conceptually divided into a first half or sub volume A, and a second one R, where water adsorption by, and regeneration of, the desiccant respectively take place. While the wheel 22 rotates, the divided space envelope is stationary, with any point on wheel 22 moving through the sub volumes A and R continually and in succession, as will appear below.
Referring next to FIGS. 2 through 4, the basic framework of wheel 22 is a series of generally rectangular solid leaves 24 , of a suitable heat conductive material, most likely aluminum. The edges of the leaves 24 subtend the entire envelope, axially from F to B, and radially from T to O, but are not straight, like spokes of a wheel. Instead, they are folded over into a curve or spiral pattern so as to have a constant separation at any point, rather than a separation that radially diverges in a pie shape, as would spokes of a wheel. This is a known configuration, the advantage of which is that fins of a constant height can be contained between the leaves 24 , which is a great manufacturing advantage. This regularly spaced arrangement of leaves 24 creates a series of regular subdivisions or cells, which are distinguished according to a type and shape of corrugated fin that they contain, and according to whether they are open or closed, axially and radially. Specifically, a first set of every other cell, indicated at D, contains a first type of corrugated fin 26 , formed of a conductive material comparable to the leaves 24 . Fin 26 has constant height corrugations, which are oriented axially and parallel to axis X, extending axially all the way from F to B, and radially all the way from T to O. The cells D of the first set are axially open at both faces F and B, so that air can flow over them parallel to axis X. The fins 26 are inherently radially blocked to flow, however, as are the cells D, because of the axial orientation of the corrugations. The peaks of the corrugations of fin 26 are closely engaged with, and preferably brazed to, the inner surfaces of the leaves 24 that border them. In addition, the surfaces of the corrugations of fins 26 are coated with a suitable desiccant material, such as zeolite, hence the designation D. Between each cell D is an intermediate cell C, distinguished by a different shaped fin 28 that it contains. Cells C of the second of cells house a fin 28 with corrugations of equal height and of the same conductive material, but bare of desiccant material, as it is intended only for heat conduction (hence the designation “C”). Each fin 28 extends radially from O to T, but deliberately not all the axially way from F to B. Instead, each axial end of each fin 28 is sliced off at an angle and both the front and back ends, as best seen in FIG. 4 . This leaves a radial opening through O near the back end face B, and a diagonally opposed radial opening through T near the front end face F, in each cell C. While they are radially open, the cells C are deliberately axially blocked at both end faces F and B, preventing any straight through axial flow that could otherwise occur. The fins 28 are also closely engaged between adjacent leaves 24 , preferably brazed thereto. Brazing of all the fins 26 and 28 between the leaves 24 would create a solid core assembly, just as in a typical plate type heat exchanger. In addition, as disclosed, the tunnel T is capped or blocked at the front face F, for a purpose described below. The radial perimeters of the wheel 22 at the radial limits 0 and T will be inherently “rough” or jagged, more so as the cells are fewer and thicker, and less so as they are increased in number and made thinner. If desired, an additional cylindrical sleeve could be added at both O and T, covering the otherwise jagged perimeter and providing a smoother potential sealing surface on the turning wheel 22 , so long as they did not block the inner and outer radial openings into and out of the cells C. In conclusion, it will be noted that essentially every bit of the space envelope as defined is occupied by cells and their associated fins, with no “dead” or unoccupied space.
Referring next to FIGS. 1, 4 and 5 , wheel 22 is located within HVAC housing 12 , upstream of evaporator core 14 , and associated with a system of ducts, seals, and other components designed to concurrently send various air flows into and out of the cells D and C, depending upon their position within the space envelope subdivisions A and R. A motor 30 turns wheel 22 slowly so that the cells D and C continually move successively through the volumes A and R, at a slow rate of approximately one RPM. The demarcation of the sub volumes A and R is created by a front rubbing seal 32 that bears against the wheel front end face F, and a matching rear rubbing seal 34 that bears against the back end face B. Each seal 32 and 34 has concentric, circular inner and outer perimeters that match the diameters of the wheel outer wall O and inner tunnel T, and which are joined by diametrically opposed cross members, which divide the seals into two halves, in effect, and which thereby serve to direct and confine various air flows into and out of selected ones of the sub volumes A and R as defined above. In addition, the rear rubbing seal 34 includes a semi-cylindrical half sleeve 36 that extends axially inwardly into the wheel central tunnel T, within the sub volume R only, and just far enough to cover and block the radially inner openings into the tunnel T created by the sliced off back end of the fins 28 . Each seal 32 and 34 is fixed to ducts that are stationary to and integral to the housing 12 . Specifically, half of the front rubbing seal 32 is fixed to an outside air feed duct 38 , integral to housing 12 , bearing against the wheel front face F. A rear duct 40 matching the air feed duct 38 , also integral to housing 12 , mounts half of the rear rubbing seal 34 so as to bear closely against wheel back face B. The other half of the rear rubbing seal 34 is fixed to a regeneration air duct 42 , side by side and integral with duct 40 , and held closely against the wheel back face B. In the embodiment disclosed, the regeneration air duct 42 covers the uncapped end of the wheel's central tunnel T, where it also mounts a cylindrical regeneration heater 44 concentric to and just outside of the open end of tunnel T. A regeneration air exhaust duct 46 , side by side and integral with outside air duct 38 , mounts the other half of front rubbing seal 32 close against the wheel front face F. A stationary cross flow feed manifold 48 sealingly engage that half of the wheel outer wall O that is located within the sub volume A. An auxiliary blower 50 forces outside air (or air from some other source, such as the vehicle interior, that is at ambient or lower temperature) into the cross flow manifold 48 . These various ducts and seals cooperate with wheel 22 in a fashion described in detail next.
Still referring to FIGS. 1, 4 and 5 , whenever the air conditioning compressor is activated and the evaporator core 14 is cold, a suitable control system and sensors would determine when the ambient temperature and humidity were sufficient to require dehumidification. Motor 30 begins to turn, auxiliary blower 50 comes on, and regeneration heater 44 is activated. Most likely, regeneration heater 44 , like standard heater core 16 , would simply be fed by engine coolant, and always active, since its presence is irrelevant unless air is directed through it, which does not occur unless auxiliary blower 50 is on. The combination of an active blower 50 and motor 30 establishes several independent and concurrent air flows, which eventually reach an equilibrium. Each flow will be described separately, but their concurrence should be kept in mind. Outside air drawn in by the main blower 20 is forced against the wheel front face F, and, being axially blocked from the tunnel T (which is capped at F) and from the cells C, as well as blocked by the front rubbing seal 32 from the cells D that are located in the sub volume R, can pass axially through only those cells D located in the sub volume A, the “adsorption half” of wheel 22 . About half of the cells D and C are located within the sub volumes A and R at any point in time. The outside air passes over the desiccant coating the fins 26 , which adsorbs water from it, forming a complex molecule and releasing heat, known as the latent heat of vaporization. Just as it takes a good deal of energy to evaporate water into the air initially, a comparable amount of energy is released as heat when it is adsorbed, approximately 972 BTU/lb. This latent heat released within the desiccant coating raises the temperature of the underlying fin 26 , conducting heat to the adjacent leaves 24 and into the fins 28 of the adjacent cells C. Concurrently, a cross flow outside air at ambient temperature (or comparably cool air from another source) is being forced by blower 50 through manifold 48 and radially into only those cells C located within the sub volume A. The cross flow air moves axially across and radially inwardly through the fins 28 in the adjacent cells C, picking up most of the released latent heat conducted into them. Therefore, the outside air exiting into the rear duct 40 and reaching the evaporator core 14 is drier, but not nearly as heated as it would have been without the cooling cross flow through the cells C. The evaporator core 14 is thus kept dry, but not forced to take on all the released latent heat that it otherwise would. The cross flow of air heated with those cells C located in the sub volume A is not simply exhausted back to ambient, in the embodiment disclosed. Instead, cross flow air enters the tunnel T through the openings provided by the cut away fins 28 , where it is axially blocked at the wheel front face F (and thereby prevented from leaking back into the outside air duct 38 ). Heated cross flow air entering the tunnel T is also radially blocked by the half sleeve 36 from entering those cells C located in the sub volume R, it is therefore forced to flow axially out of tunnel T through the back face B and through the regeneration heater 44 . Heater 44 raises the air flow further to a temperature of approximately 170 to 180 degrees Fahrenheit, after which it enters regeneration duct 42 and is forced to loop around and back against the wheel back face B. The heated air in duct 42 is kept within only the sub volume R by the rear rubbing seal 34 and, being unable to re enter the axially blocked cells C, flows axially through only those cells D located within the sub volume R. Within the sub volume R, the desiccant on the fins 26 contain the water adsorbed from their previous trip through the sub volume A. That water is desorbed and driven out by the air heated by heater 44 , regenerating the desiccant, and exhausted from the wheel front face F through the exhaust duct 46 and back to the outside. Again, within the sub volume R, here is no cross cooling flow through the cells C to cool off the adjacent cells D and impact the efficiency of the desiccant regeneration process, because of the blockage provided by half sleeve 36 .
In conclusion, maximum use is made of the available space within the wheel 22 , while the various air flows are directed by the ducts and seals to those parts of the wheel 22 where they are most effective, and blocked from those parts of the wheel 22 where they are potentially counter productive. Variations in both the structure of wheel 22 and the various ducts and seals could be made. The leaves 24 could be flat and radiate like spokes of a wheel, creating cells that were pie shaped, rather than constant in height. However, the fins to fit within pie shaped cells would be much more difficult to manufacture, not having constant height corrugations. The fins 26 and 28 within the two respective sets of cells D and C could be shaped differently, so long as they were axially open through the cells D (which cells are radially blocked), and radially open through the cells C (which cells are axially blocked). For example, the fins 28 within the cells C could maintain the axially oriented corrugations, but be louvered or otherwise relieved in the corrugation walls so as to allow a radial flow. If the fins in the cells C could be manufactured with corrugation walls that were radial, rather than axially oriented, they would provide a radial flow path, while inherently blocking axial flow through the cells C. It would be very difficult to get fins with radially oriented corrugations to conform to the curved shape of the cells C, however. As far as the ducts and seals disclosed, the outside air flow and the regenerating air flows could be directed at either face of the wheel 22 , and could flow either in the same direction, or opposed directions, so long as the seals kept the two flows confined to the two respective sub volumes A and R as defined. The cross flow cooling air exiting those cells C located within the sub volume A could flow in either radial direction, although it is clearly easier to direct it radially inwardly through the outer wall O and then exhaust it out of the tunnel T, rather than vice versa. The cross flow cooling air running through the cells C could simply be exhausted to the outside without being raised in temperature and then looped around back into the regeneration duct 42 . However, using the exhausted heated cross flow air from the cells C located within the sub volume A as pre heated air for the regeneration half of the wheel 22 is desirable for overall thermal efficiency. A regeneration air exhaust duct like 46 is not absolutely necessary, as the regeneration air exiting the cells D located within the sub volume R would be exhausted from the wheel 22 , anyway. Therefore, it will be understood that it is not intended to limit the invention to just the embodiment disclosed. | An improved dehumidification system for automotive use includes a rotating, wheel like heat exchanger with axially open cells that carry a water adsorbing material. Opposed ambient air and heated air flows, covering opposite halves of the wheel, continually adsorb water on one side and are recharged on the other side. Alternating radially closed cells between the axially open cells carry no desiccant material, but receive a cross cooling flow, on the water adsorbing side of the wheel only, to remove the heat released during the water adsorption process. The desiccant recharging process on the other side of the wheel is not disturbed by the cross cooling flow. | 8 |
BACKGROUND
1. Field of the Invention
This invention relates to a method for manufacturing integrated circuits and, more specifically to a method for retaining the integrity of a photoresist pattern during the manufacture of semiconductor integrated circuits.
2. Related Art
In the manufacture of semiconductor integrated circuits, a variety of photolithographic steps are employed. These photolithographic steps encompass forming a layer of photosensitive material, photoresist, overlying a surface of a semiconductor wafer or substrate and defining a pattern therein. Typically, the pattern formed is used to mask portions of an underlying layer to allow unmasked portions of the underlying layer to be removed. The removal of the material of such underlying layers is often performed using a plasma etching process, for example a reactive ion etch process. While in some etch processes the photoresist layer maintains its integrity, that is little or no photoresist is removed and the cross-sectional profile of the resist remains essentially unchanged, in other etch processes the photoresist is removed at a rate comparable to the removal rate of the underlying layer. This loss of integrity is known to affect the patterning of the underlying layer. For example, in some cases the desired feature sizes, as defined by the original photoresist pattern, are not reproduced. In some embodiments portions of the desired features are missing and in some cases both feature size and presence are affected.
Various attempts have been made to improve photoresist integrity during semiconductor processing. For example, it is generally known that baking the photoresist layer, often referred to as a hard bake, after the pattern is formed and immediately prior to a plasma etch improves integrity. In addition, it is known that a blanket exposure of the patterned photoresist with an ultraviolet (UV) light improves photoresist integrity. It is also known to use both a hard bake and UV exposure in combination to improve photoresist integrity. However, such independent or combined use of bakes and blanket UV exposure are at best marginally acceptable for some necessary etch processes, for example some metal etch processes.
Therefore it would be desirable for there to be a process for forming a patterned photoresist layer with improved integrity for use in some etch processes. It would also be desirable for this process to be readily integrated into standard semiconductor processing.
SUMMARY
A method of retaining the integrity of an as formed pattern of a photoresist layer after a plasma etch process is provided. Embodiments in accordance with the present invention provide a plasma treatment for a patterned photoresist layer. In some embodiments an I-line photoresist is employed; in other embodiments a deep UV (DUV) photoresist is employed.
The plasma treatment of the present invention is advantageously performed prior to a plasma etch process for etching a layer or layers underlying the patterned photoresist. In some embodiments of the present invention the plasma treatment provided additionally serves to etch a silicon oxide layer formed over an underlying metal layer. In some embodiments of the present invention a plasma encompassing a fluorocarbon is employed for the plasma treatment.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention may be better understood, and its numerous objects, features, and advantages made apparent to those skilled in the art by referencing the accompanying drawings. For ease of understanding and simplicity, where elements are common between illustrations, common numbering of those elements is employed between illustrations.
FIGS. 1 a and 1 b are cross-sectional views of a portion of a semiconductor integrated circuit depicting portions of a patterned photoresist layer;
FIG. 2 is a cross-sectional view of a portion of a semiconductor integrated circuit showing an etched pattern having severe photoresist degradation in a manner common to the prior art; and
FIGS. 3 a and 3 b are cross-sectional views of the portion of the semiconductor integrated circuit depicted in FIGS. 1 a and/or 1 b at subsequent stages of a process in accordance with the present invention.
DETAILED DESCRIPTION
As embodiments of the present invention are described with reference to the drawings, various modifications or adaptations of the specific methods and or structures may become apparent to those skilled in the art. For example, in some embodiments of the present invention, a silicon oxynitride layer is employed in place of a silicon oxide layer. All such modifications, adaptations or variations that rely upon the teachings of the present invention, and through which these teachings have advanced the art, are considered to be within the spirit and scope of the present invention.
In FIG. 1 a , a cross-sectional view of an embodiment of a semiconductor integrated circuit depicting a patterned photoresist layer is shown. A metal layer 20 is represented overlying a semiconductor substrate 10 . Metal layer 20 encompasses aluminum, copper or any of the alloys of aluminum and copper as are known. In addition, layer 20 includes any of the known multilayer metal films, for example an aluminum film overlying a barrier layer of titanium nitride (TiN).
Layer 30 is an anti-reflective coating (ARC). Such ARC layers 30 are used to reduce or eliminate the effects of standing waves formed by reflections during exposure of the photoresist layer (not shown) from which photoresist portions 50 are formed. As known, the use of ARC layers often improves the resolution of an image projected onto the photoresist layer for forming portions 50 . As depicted, ARC layer 30 is an inorganic material, for example TiN or titanium tungsten (TiW), and is patterned with underlying metal layer 20 . In some embodiments an organic ARC layer (not shown) is used. Typically, such organic ARC layers are patterned when the photoresist layer is developed to form portions 50 . Finally, in some embodiments of the present invention, no ARC layer 30 is employed.
Photoresist portions 50 are formed by projecting an image onto the photoresist layer (not shown) and subsequently developing that image. Portions 50 can be formed from a variety of materials. Typically, such materials are sensitive to a specific, narrow range of the electromagnetic spectrum. For example, some photoresist materials are sensitive to the mercury vapor I-line at 365 nanometers (nm), while other materials are sensitive to what is known as the deep ultra violet (DUV) range at about 245 nm. While in some embodiments of the present invention, an I-line photoresist material having a thickness 52 of approximately 1.3 micron (μm) or a DUV sensitive photoresist material having a thickness 52 of approximately 1.0 μm is employed, it will be understood that embodiments of the present invention also encompass other appropriate photosensitive materials and thicknesses; for example, G-line (436 nm) and electron beam resist materials.
Still referring to FIG. 1 a , semiconductor substrate 10 is depicted as having a minimum of complexity for simplicity and ease of understanding only. Thus it is understood that embodiments of the present invention include alternate substrates 10 having a variety of complexity. For example, in some embodiments substrate 10 is an N-type or P-type substrate, or is an N-type or P-type substrate encompassing N and/or P-type well regions (not shown) and/or an epitaxial layer (not shown). Alternatively, in some embodiments, substrate 10 encompasses a silicon on insulator (SOI) structure, or any other appropriate semiconductor substrate material or structure.
Turning now to FIG. 1 b , another embodiment of the present invention is depicted incorporating an isolation/capping layer 40 . As known, some photosensitive materials are not compatible with some ARC materials. Thus where photoresist portions 50 are to be formed, for example of a DUV photoresist material, a TiN or TiW ARC layer 30 will typically interact with the DUV photoresist material if direct contact between the materials occurs. Hence to prevent this interaction between the ARC material and DUV photoresist, capping/isolation layer 40 is used. An additional benefit of capping layer 40 is to provide for improved adhesion of the DUV photoresist than would be possible if the DUV photoresist were disposed directly on ARC layer 30 . Generally layer 40 is a silicon oxide material formed by chemical vapor deposition or other appropriate method and has a thickness of between 10 to 80 nm. However, other materials, for example a silicon oxynitride, can also be advantageously employed.
Thus, FIGS. 1 a and 1 b , as described, are representative of a photoresist pattern, prior to etching the underlying metal layer 20 . In addition, it will be understood that both FIGS. 1 a and 1 b are consistent with semiconductor processing as known and serve as common points from which prior art processes and embodiments of the present invention diverge.
Turning now to FIG. 2, a cross-sectional view of a portion of a semiconductor integrated circuit showing an etched pattern having severe photoresist degradation is depicted. FIG. 2 is meant to be representative of the structures of FIGS. 1 a and/or 1 b after etching of layer 20 to form metal portions 22 in the manner of the prior art. As shown, after etch, residual photoresist portions 55 are markedly changed with respect to portions 50 as depicted in FIGS. 1 a and/or 1 b . The essentially square corners of portions 50 (FIGS. 1 a and 1 b ) are gone and residual thickness 54 is significantly less than thickness 52 (FIGS. 1 a and 1 b ). As shown, the severe degradation depicted by portions 55 results in associated degradation of metal portions 22 . For example, corners 24 are deformed from the original shape of photoresist portions 50 . While not shown, it has been reported that some processes for etching metal layer 20 to form metal portions 22 will remove essentially all of original photoresist portions 50 resulting in metal portions 22 with severe deformations. Thus it can be seen that a method for preventing such severe deformation of photoresist portions 50 (FIGS. 1 a and 1 b ) is desirable.
FIG. 3 a is a cross-sectional view of the portion of the semiconductor integrated circuit depicted in FIG. 1 b after a plasma treatment in accordance with embodiments of the present invention. Photoresist portions 60 are depicted overlying patterned isolation portions 45 , ARC layer 30 , metal layer 20 and substrate 10 . It should be noted that while treated photoresist portions 60 are depicted having rounded corners 62 , this representation is presented solely to distinguish treated portions 60 from untreated portions 50 (FIGS. 1 a and 1 b ). Thus after treatment, photoresist portions 60 may or may not have such rounded corners 62 .
In some embodiments of the present invention after photoresist portions 50 (FIG. 1 b ) are defined, substrate 10 is positioned in a vacuum chamber (not shown) and treated with a plasma for a predetermined time. For example, in some embodiments a plasma formed from fluoroform (CHF 3 ), carbon tetrafluoride (CF 4 ), nitrogen (N 2 ) and argon (Ar) is ignited in a vacuum chamber at a pressure of between approximately 100 to 300 milliTorr (mT) using between approximately 100 to 600 watts (W) of electrical energy. Once ignited, the plasma is maintained for a predetermined time sufficient to adequately treat portions 50 and form treated photoresist portions 60 . It has been found that a time of between approximately 5 to 20 seconds (sec) is appropriate. It will be understood that the above mentioned ranges for pressure, electrical energy and time are dependent upon, among other things, the specific resist employed for portions 50 . Thus, these ranges are given for illustrative purposes and are not intended to be limiting. Rather, any appropriate combination of pressure, electrical energy and time that results in forming treated photoresist portions 60 is within both the scope and spirit of the present invention.
It will also be understood that within each appropriate gas mixture used for forming treated portions 60 , the specific ratio of the individual components of the mixture can vary to meet specific requirements. Therefore, some embodiments of the present invention encompass gas mixtures of CHF 3 with a flow rate of between approximately 30 to 60 standard cubic centimeters per minute (sccm), CF 4 with a flow rate between approximately 0 to 40 sccm, N 2 with a flow rate of between approximately 10 to 40 sccm and Ar with a flow rate of between approximately 150 to 450 sccm. It will be understood that, as for the other ranges previously mentioned, the above flow rate ranges are likely to be different where different resist materials are used for forming photoresist portions 50 (FIG. 1 b ). Thus, these flow rate ranges are given for illustrative purposes and are not intended to be limiting. Hence, any appropriate combination of pressure, electrical energy, time and gas flow rates that results in forming treated photoresist portions 60 is within both the scope and spirit of the present invention.
Still referring to FIG. 3 a , it has been found that for embodiments having a silicon oxide or silicon oxynitride isolation/capping layer 40 (FIG. 1 b ), the above described plasma treatment for forming treated portions 60 also serves to etch layer 40 to form etched isolation portions 45 . Thus, in some embodiments of the present invention a plasma is maintained in the vacuum chamber for a predetermined time sufficient to both form isolation/capping portions 45 and treated photoresist portions 60 , respectively. For example, where photoresist portions 50 (FIG. 1 b ) are a DUV resist material and isolation layer 40 is a silicon oxide material having a thickness of approximately 20 nm, it has been found that 15 sec in a plasma formed from a gas mixture of 50 sccm CHF 3 , 20 sccm N 2 and 300 sccm Ar, at a pressure of approximately 150 mT and at 500 W of electrical energy advantageously form treated portions 60 .
Turning now to FIG. 3 b , the structure of FIG. 3 a is depicted subsequent to etching ARC layer 30 and metal layer 20 to form patterned ARC portions 35 and metal portions 25 . In addition, treated photoresist portions 60 (FIG. 3 a ) are represented as post-etch photoresist portions 65 having rounded corners 67 . While the exact shape of post-etch portions 65 vary, as represented herein, post-etch portions 65 retain most of their original shape after metal etch. As a result of retaining the integrity of the photoresist pattern, the dimensions of the underlying metal portions 25 are much improved as compared to prior art metal portions 22 (FIG. 2 ).
Thus it can be seen that embodiments in accordance with the present invention have been described that provide for retaining the integrity of a photoresist pattern during a subsequent plasma etch process. It is known that metal etch processes employed in the semiconductor arts require some interaction with the photoresist to attain the highest anisotropic character. Thus it is significant that embodiments of the present invention allow for sufficient interaction with the photoresist to provide this anisotropy, while not allowing degradation to the degree common in the prior art. It will also be understood that embodiments of the present invention have been described that are readily integrated into a typical semiconductor fabrication process. For example, in some embodiments of the present invention the aforementioned plasma treatment is accomplished using a standard oxide etch system, for example a LAM® 4520 or the like (LAM is a registered trademark of LAM Research, Inc., Fremont, Calif.), while in some embodiments the plasma treatment is incorporated as a preliminary step of a monolithic metal etch process.
In addition, it will be realized that embodiments of the present invention incorporate various combinations of photoresist materials and ARC materials both with and without a capping or isolation layer. Thus, for example, in some embodiments an I-line resist material is used with both a capping layer and an ARC layer, while other embodiments incorporate a DUV resist material, an organic ARC material and no capping layer. | A method of retaining the integrity of a photoresist pattern is provided where the patterned photoresist is treated prior to etching the principle layer. The pre-etch treatment encompasses a plasma treatment. In some embodiments employing an anti-reflective coating (ARC) layer, an isolation/protective layer is used to isolate the ARC from the photoresist. In some embodiments, the pre-etch treatment, advantageously provides for patterning the isolation/protection layer. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. Ser. No. 13/233,118, filed Sep. 15, 2011, which issued as U.S. Pat. No. 8,166,712, which was a continuation of U.S. Ser. No. 12/553,453, filed Sep. 3, 2009, which issued as U.S. Pat. No. 8,042,304.
FIELD OF THE INVENTION
[0002] The present invention relates to rain gutters for houses or the like. More particularly, the present invention concerns a porous structure that is inserted within a rain gutter to prevent the gutter from blocking or clogging with debris, such as leaves or other foreign materials.
BACKGROUND OF THE INVENTION
[0003] Rain gutters are commonly installed along the lower edges of a sloping roof under the eaves to catch water draining from the roof. Such gutters can become clogged with debris, such as leaves, twigs, seeds and pods, carried to the roof by wind or gravity and washed into the gutter. This debris fills and clogs the gutters and the gutter downspouts, causing water to overflow out of the gutters and over the eaves.
[0004] Many devices have been proposed to prevent gutters from clogging. One type of device mounts a screen or cover to the open, upper portion of the gutter. Such screens or covers are intended to permit water to flow through, while at the same time catching the debris. Unfortunately, over a period of time, the leaves and foreign matter collect on the devices and disrupt, divert or prevent water from flowing through the device into the gutter. Consequently, screen-type devices require periodic cleaning or maintenance to ensure proper operation.
[0005] Foam filters for gutter systems have been disclosed. U.S. Pat. No. 7,208,081 shows a gutter foam filter formed from columns of open-pore polyether foam, where the columns have a cross sectional shape of a truncated triangle. The columns are held within the gutter underneath a series of gutter spikes. Such foam must be cut to fit gutters of varying width.
[0006] U.S. Pat. No. 4,949,514 concerns a gutter liner formed from solid porous material, such as a reticulated porous polyurethane foam. A flat panel of the porous material is folded into an inverted “U”-shape to define a water channel between the two legs of the inverted “U”. Undulations are formed on the top barrier surface. Ridges may be formed on the outer side surfaces of the liner to engage the side walls of the gutter. When installed within a gutter, such liner structure generally includes a spacer means to keep the side walls of the inverted “U”-shape separate from one another to define the water channel.
[0007] Other foam gutter protectors or inserts have generally trapezoidal cross-sections, optionally with ridges or projections extending from one or multiple surfaces. Long panels or columns of foam are so shaped by cutting away foam material, which generates foam waste.
[0008] Improvements to foam gutter protectors and inserts continue to be sought.
SUMMARY OF THE INVENTION
[0009] In a first aspect, an elongated gutter insert has at least five sides in cross-section wherein a first acute angle (α) is formed between a generally flat top surface and a rear surface, a second acute angle (β) is formed between the top surface and a first front surface, a reflex angle (γ) is formed between the first front surface and the second front surface, a third acute angle (δ) is formed between the second front surface and a bottom surface, and a fourth acute angle (ε) is formed between the rear surface and the bottom surface. Preferably, the first acute angle (α) is in the range of about 65 to about 75 degrees, the second acute angle (β) is in the range of about 15 to about 25 degrees, the third acute angle (δ) is in the range of about 85 to about 95 degrees, the fourth acute angle (ε) is in the range of about 60 to about 70 degrees, and the reflex angle (γ) is in the range of about 290 to about 310 degrees. The corners between surfaces may be sharp, or may be chamfered, beveled or curved. The top surface of the gutter insert has a width that is longer than or approximately the same as a width of a gutter passageway into which the gutter insert is to be installed.
[0010] The gutter insert may be of flexible open pore foam having pore count of about 3 to 25 pores per inch, and density in the range of about 1.0 to 3.5 pounds per cubic foot. Preferably, the foam is reticulated. The foam may have an anti-microbial agent and/or a liquid fire retardant incorporated therein or thereon, or may have a coating thereon that contains one or more of a fire retardant, anti-microbial agent and UV protectant.
[0011] In a second aspect, a gutter system comprises a gutter associated with a building roof system and defining a passageway, and a gutter insert inserted in such passageway.
[0012] In a third aspect, a gutter insert system has a column of foam having a generally square cross-section that comprises four nested together gutter inserts. Each gutter insert has at least five sides in cross-section with a first acute angle (α) formed between a generally flat top surface and a rear surface, a second acute angle (β) formed between the top surface and a first front surface, a reflex angle (γ) formed between the first front surface and the second front surface, a third acute angle (δ) formed between the second front surface and a bottom surface, and a fourth acute angle (ε) formed between the rear surface and the bottom surface. The gutter inserts of the gutter insert system are separable from one another for installation into a gutter passageway. The gutter inserts are formed by cutting the column of foam with two intersecting “Z” or generally “S” patterns, resulting in four nested together gutter inserts. One or more corners of the gutter inserts may be chamfered, beveled or curved.
[0013] In a fourth aspect, a method for making a gutter insert includes the steps of: (a) providing a column of foam having a length and having a generally square cross section, wherein a width of each side of such square is approximately the same as or wider than a width of a gutter passageway into which the gutter insert is to be installed; and (b) slicing the column along its length into four separable gutter inserts. Preferably, the four gutter inserts have substantially identical cross-sectional shapes, and each gutter insert has at least five-sides in cross-section wherein a first acute angle (α) is formed between a generally flat top surface and a rear surface, a second acute angle (β) is formed between the top surface and a first front surface, a reflex angle (γ) is formed between the first front surface and the second front surface, a third acute angle (δ) is formed between the second front surface and a bottom surface and a fourth acute angle (ε) is formed between the rear surface and the bottom surface.
DESCRIPTION OF THE FIGURES
[0014] Numerous other objects, features and advantages of the invention shall become apparent upon reading the following detailed description taken in conjunction with the accompanying drawings, in which:
[0015] FIG. 1 is a right front perspective view of a column of foam;
[0016] FIG. 2 is a right front perspective view of the column of foam of FIG. 1 that has been sliced to form four gutter inserts according to a first embodiment of the invention;
[0017] FIG. 3 is a right front perspective view of the four gutter inserts of FIG. 2 as separated apart from one another;
[0018] FIG. 4 is a right end elevational view of the column of foam as sliced according to FIG. 2 , where the left end elevational view is a mirror image thereof;
[0019] FIG. 5 is a right front perspective view of a “K”-type gutter into which a gutter insert according to the first embodiment of the invention has been installed;
[0020] FIG. 6 is a cross-sectional view of the gutter and gutter insert of the first embodiment taken along line 6 - 6 of FIG. 5 ;
[0021] FIG. 7 is a right end elevational view of a column of foam that has been sliced to form four gutter inserts according to a second embodiment of the invention;
[0022] FIG. 8 is a right front perspective view of a “K”-type gutter into which a gutter insert according to the second embodiment of the invention has been installed;
[0023] FIG. 9 is a right end elevational view of a column of foam that has been sliced to form four gutter inserts according to a third embodiment of the invention; and
[0024] FIG. 10 is a right front perspective view of a “K”-type gutter into which a gutter insert according to the third embodiment of the invention has been installed.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] With reference to the drawings in which like numerals designate similar elements, gutter inserts 20 a , 20 b , 20 c , 20 d according to a first embodiment of the invention may be made from a column 10 of foam as shown in FIG. 1 . The column 10 has a generally square cross-section with four generally straight sides 12 , 14 , 16 , 18 of approximately the same width. The column 10 may have any length, as desired. A representative suitable length is from 6 feet to ten feet.
[0026] Referring to FIGS. 2 and 3 , the column 10 is sliced or cut longitudinally with a blade, a cutting wire, a band knife or other cutting device suitable for cutting compressible material, such as foam. Preferably, the column 10 is cut with a programmable contour cutter, such as model CF 67 from Fecken Kirfel or model OFS from Baumer of America, Inc. A programmable contour cutter may be programmed to cut several columns of foam from one larger foam bun, and sequentially or concurrently make the cuts necessary to form the gutter inserts in such columns.
[0027] As shown in FIGS. 2 and 4 , cuts are made in column 10 in two “Z” patterns 26 , 28 that intersect generally at a midpoint of the square cross-section forming the column 10 to create four gutter inserts 20 a , 20 b , 20 c , 20 d.
[0028] After slicing or cutting the column 10 , the four gutter inserts 20 a , 20 b , 20 c , 20 d may be separated from one another as shown in FIG. 3 . By forming the gutter inserts with this cutting method, preferably all foam material forming the column 10 is used in making the four gutter inserts 20 a , 20 b , 20 c , 20 d , such that no foam material is cut away as waste. This method efficiently produces four gutter inserts from one foam column, thus increasing production output.
[0029] Once cut, the four gutter inserts 20 a , 20 b , 20 c , 20 d may be packaged for shipment to a customer without separating. Thus, a cut column 22 as shown in FIG. 2 can be packaged separately or together with other cut columns for space-saving. The customer may separate the gutter inserts 20 a , 20 b , 20 c , 20 d from one another at the point of installation.
[0030] Each gutter insert 20 a , 20 b , 20 c , 20 d has a five-sided cross-section wherein a first acute angle (α) is formed between a generally flat top surface and a rear surface, a second acute angle (β) is formed between the top surface and a first front surface, a reflex angle (γ) is formed between the first front surface and the second front surface, a third acute angle (δ) is formed between the second front surface and a bottom surface and a fourth acute angle (ε) is formed between the rear surface and the bottom surface. The first acute angle (α) is in the range of about 65 to about 75 degrees, most preferably about 70 degrees. The second acute angle (β) is in the range of about 15 to about 25 degrees, most preferably about 20 degrees. The reflex angle (γ) is in the range of about 290 to about 310 degrees, most preferably about 295 degrees. The third acute angle (δ) is in the range of about 85 to about 95 degrees, most preferably 90 degrees. The fourth acute angle (ε) is in the range of about 60 to about 70 degrees, most preferably about 65 degrees. In the preferred embodiment, the gutter insert has a generally off-set “V” or “check-mark” configuration in cross-section.
[0031] Referring next to FIGS. 5 and 6 , each gutter insert 20 , upon being separated from the column 10 , may be installed within the interior volume of a gutter 30 to block leaves, twigs, pods, seeds and other debris from entering the gutter. When installed, the gutter insert 20 permits fluids to flow through pores of the foam material, while blocking debris. Each gutter insert 20 is installed so that its generally flat top surface 38 extends along the top opening of the gutter, with a front corner 34 and rear corner 36 in contact with the upstanding gutter 30 walls. The front corner 34 of the gutter insert 20 may seat under the front lip 32 of the front gutter wall. The rear surface 40 of the gutter insert 20 is disposed at an angle to the rear gutter wall, leaving a space between the gutter insert and the rear gutter wall. The bottom corner 50 of the gutter insert 20 contacts the bottom inner surface of the gutter. The bottom surface 42 of the gutter insert 20 is angled with respect to the bottom inner surface of the gutter. Front surfaces 46 and 48 of the gutter insert 20 are spaced a distance from the front wall of the gutter 30 . Open volume is left also between the rear surface 40 and the rear wall of the gutter 30 . As shown in FIG. 6 , a substantial portion of the inner volume within the gutter is not filled with foam material, thus allowing fluids that flow through the gutter insert 20 to flow along the length of the gutter channel in two open chambers (dual open chambers) between the gutter insert and the gutter walls until reaching a gutter downspout (not shown) without obstruction.
[0032] Each gutter insert 20 as shown in FIGS. 3 , 5 and 6 has sharp pointed corners, such as corners 34 , 36 . As a possible variation, the gutter insert 20 may be formed with rounded, chamfered or beveled corners.
[0033] Referring next to FIGS. 7 and 8 , a second embodiment of a gutter insert according to the invention is formed by cutting four gutter inserts 60 a , 60 b , 60 c , 60 d out of a foam column 62 . The cutting pattern comprises two intersecting generally “S”-shaped cutting paths 66 , 68 . Different from the first embodiment (e.g. 20 a , 20 b , 20 c , 20 d ), the gutter insert cutting pattern for the second embodiment forms fewer sharp corners.
[0034] Each gutter insert 60 a , 60 b , 60 c , 60 d has a ten-sided cross-section wherein a first acute angle (α) is formed between a generally flat top surface 70 and a rear surface 74 , a second acute angle (β) is formed between the top surface 70 and a first front surface 84 , a reflex angle (γ) is formed between the first front surface 84 and the second front surface 80 , a third acute angle (δ) is formed between the second front surface 80 and a bottom surface 78 and a fourth acute angle (ε) is formed between the rear surface 74 and the bottom surface 78 . The first acute angle (α) is in the range of about 65 to about 75 degrees, most preferably about 71 degrees. The second acute angle (β) is in the range of about 15 to about 25 degrees, most preferably about 21 degrees. The reflex angle (γ) is in the range of about 290 to about 310 degrees, most preferably about 294 degrees. The third acute angle (δ) is in the range of about 85 to about 95 degrees, most preferably about 93 degrees. The fourth acute angle (ε) is in the range of about 60 to about 70 degrees, most preferably about 63 degrees.
[0035] In addition, in the alternate embodiment of the gutter insert 60 , vertical rear surface 72 is interposed between top surface 70 and rear surface 74 , and bottom surface 76 is interposed between rear surface 74 and bottom surface 78 . Moreover, vertical front surface 86 is interposed between top surface 70 and first front surface 84 , and vertical mid surface 82 is interposed between first front surface 84 and second front surface 80 . This alternate embodiment 60 has a construction comparable to gutter insert 20 , but with some chamfered corner regions. Other variations in the cutting patterns 66 , 68 are possible, such as, but not limited to, curved regions rather than chamfered regions.
[0036] Referring next to FIGS. 9 and 10 , a third embodiment of a gutter insert according to the invention is formed by cutting four gutter inserts 90 a , 90 b , 90 c , 90 d out of a foam column 92 . The cutting pattern comprises two intersecting generally “S”-shaped cutting paths 96 , 98 . Different from the first embodiment (e.g. 20 a , 20 b , 20 c , 20 d ), the gutter insert cutting pattern for the second embodiment forms fewer sharp corners and has curved regions (e.g., 102 , 104 , 106 , 108 ).
[0037] The gutter inserts 20 , 60 , 90 have generally planar top surfaces 38 , 70 , 100 that have a width comparable or slightly longer than the gutter opening into which the gutter insert is to be installed. Multiple gutter inserts 20 , 60 , 90 are installed within a gutter channel in end to end relation to create a barrier to debris, while still permitting fluids, such as rain water, to reach the interior of the gutter channel. Fluids within the interior of the gutter channel may flow through the two open volume spaces left between the front surfaces of the gutter insert and the front gutter wall, and the rear surface(s) of the gutter insert and the rear gutter wall. As such, dual chambers are formed to direct fluids along the gutter channel toward the gutter downspout. One or more additional fluid-directing chambers may be formed by varying the configuration of the bottom corner 50 of gutter insert 20 or the bottom surface 76 of gutter insert 60 or the bottom curved surface 110 of gutter insert 90 .
[0038] The foam forming the gutter inserts 20 , 60 , 90 preferably is a flexible, open pore polyether polyurethane foam. The open pore foam permits water or other liquids that impinge on the top surface 38 , 70 , 100 of a gutter insert 20 , 60 , 90 to pass therethrough, while filtering or blocking debris, such as leaves or twigs, that may be carried by water along the roof. Such foam may be reticulated to remove cell windows and increase the porosity and liquid permeability of such foam. Thermal or chemical reticulation methods may be used. Pore count or pore size of such foam is preferably between 3 to 25 pores per inch, most preferably between 5 to 15 pores per inch. Foam density is preferably between about 1.0 and 3.5 pounds per cubic foot, or between 1.4 to 3.5 pounds per cubic foot before any coating is applied. If a coating is applied, such coating may increase the density from 10% to 350%, or greater if desired.
[0039] Various additives may be incorporated into the foam-forming mixture. For example, one or more liquid fire retardants and anti-microbial additives may be included in situ when forming the foam. In addition, coatings may be applied to the formed foam. For example, one or more UV inhibitors, anti-microbial agents and/or liquid fire retardants may be applied to the foam as a coating or as multiple coatings.
[0040] While preferred embodiments of the invention have been described and illustrated here, various changes, substitutions and modifications to the described embodiments will become apparent to those of ordinary skill in the art without thereby departing from the scope and spirit of the invention. | A gutter insert formed of a flexible open cell porous foam has five or more sides and forms an inverted “V” or check-mark shape. Four gutter inserts may be cut from one column of foam material, thereby reducing foam waste. The four gutter inserts may be shipped nested together in columnar form, and separated at the jobsite just before installation. | 1 |
FIELD OF THE INVENTION
This invention relates to a method for separating 4-methyl-2-pentanone from formic acid using certain dimethylamides as the agent in extractive distillation.
DESCRIPTION OF PRIOR ART
Extractive distillation is the method of separating close boiling compounds or azeotropes by carrying out the distillation in a multi-plate rectification column in the presence of an added liquid or liquid mixture, said liquid(s) having a boiling point higher than the compounds being separated. The extractive agent is introduced near the top of the column and flows downward until it reaches the stillpot or reboiler. Its presence on each plate of the rectification column alters the relative volatility of the close boiling compounds in a direction to make the separation on each plate greater and thus require either fewer plates to effect the same separation or make possible a greater degree of separation with the same number of plates. When the compounds to be separated normally form an azeotrope, the proper agents will cause them to boil separately during the extractive distillation and thus make possible a separation in a rectification column that cannot be done at all when no agent is present. The extractive agent should boil higher than any of the close boiling liquids being separated and not form minimum azeotropes with them. Usually the extractive agent is introduced a few plates from the top of the column to insure that none of the extractive agent is carried over with the lowest boiling component. This usually requires that the extractive agent boil twenty Centrigrade degrees or more higher than the lowest boiling component.
At the bottom of a continuous column, the less volatile component of the close boiling mixtures and the extractive agent are continuously removed from the column. The usual methods of separation of these two components are the use of another rectification column, cooling and phase separation or solvent extraction.
4-Methyl-2-pentanone, B. P.=117° C. and formic acid, B. P.=101° C. possess an average relative volatility of about 1.3 and boil so close together that they are difficult to separate by conventional rectification. Extractive distillation would be an attractive method of effecting the separation of 4-methyl-2-pentanone from formic acid if agents can be found that (1) will enhance the relative volatility of 4-methyl-2-pentanone to formic acid and (2) are easy to recover from the formic acid, that is, form no azeotrope with formic acid and boil sufficiently above formic acid to make separation by rectification possible with only a few theoretical plates.
Extractive distillation typically requires the addition of an equal amount to twice as much extractive agent as the 4-methyl-2-pentanone-formic acid on each plate of the rectification column. The extractive agent should be heated to about the same temperature as the plate on to which it is introduced. Thus extractive distillation imposes an additional heat requirement on the column as well as somewhat larger plates. However this is less than the increase occasioned by the additional agents required if the separation is done by azeotropic distillation. Another consideration in the selection of the extractive distillation agent is its recovery from the bottoms product. The usual method is by rectification in another column. In order to keep the cost of this operation to a minimum, an appreciable boiling point difference between the compound being separated and the extractive agent is desirable. It is desirable that the extractive agent be miscible with formic acid otherwise it will form a two-phase azeotrope with the formic acid in the recovery column and some other method of separation will have to be employed.
Berg, U.S. Pat. No. 4,692,219 separated formic acid from acetic acid by extractive distillation. Extractive distillation was used by Berg, U.S. Pat. No. 4,735,690 to remove water and impurities from formic acid and Berg, U.S. Pat. No. 4,793,901 to break the 2-pentanone-formic acid azeotrope.
OBJECTIVE OF THE INVENTION
The object of this invention is to provide a process or method of extractive distillation that will enhance the relative volatility of 4-methyl-2-pentanone from formic acid in their separation in a rectification column. It is a further object of this invention to identify suitable extractive distillation agents that will separate the 4-methyl-2-pentanone-formic acid mixture and make possible the production of pure 4-methyl-2-pentanone and formic acid by rectification. It is a further object of this invention to identify certain amides which in addition to the above constraints, are stable, can be separated from formic acid by rectification with relatively few theoretical plates and can be recycled to the extractive distillation column and reused with little or no decomposition.
SUMMARY OF THE INVENTION
The objects of the invention are provided by a process for separating 4-methyl-2-pentanone from formic acid which entails the use of dimethyl-formamide or dimethylacetamide, either alone or admixed with certain oxygenated organic compounds as the agents in extractive distillation.
TABLE 1__________________________________________________________________________Effective Extractive Distillation Agents Containing DMFA RelativeCompounds Ratios Volatilities__________________________________________________________________________Dimethylformamide (DMFA) 1 6/5 2.0 1.9DMFA, Hexanoic acid (1/2).sup.2 (3/5).sup.2 1.7 1.3DMFA, Heptanoic acid (1/2).sup.2 (3/5).sup.2 1.1 1.3DMFA, Itaconic acid (1/2).sup.2 (3/5).sup.2 1.2 1.1DMFA, Neodecanoic acid (1/2).sup.2 (3/5).sup.2 1.2 1.1DMFA, Octanoic acid (1/2).sup.2 (3/5).sup.2 1.4 1.2DMFA, Pelargonic acid (1/2).sup.2 (3/5).sup.2 1.2 1.1DMFA, Hexanoic acid, Methyl benzoate (1/3).sup.3 (2/5).sup.3 1.6 1.4DMFA, Heptanoic acid, Ethyl benzoate (1/3).sup.3 (2/5).sup.3 1.3 1.3DMFA, Itaconic acid, 2-Octanone (1/3).sup.3 (2/5).sup.3 1.2 1.4DMFA, Neodecanoic acid, Benzyl acetate (1/3).sup.3 (2/5).sup.3 1.1 1.4DMFA, Octanoic acid, Butyl benzoate (1/3).sup.3 (2/5).sup.3 1.3 1.3DMFA, Pelargonic acid, Benzyl acetate (1/3).sup.3 (2/5).sup.3 1.1 1.5__________________________________________________________________________
TABLE 2__________________________________________________________________________Effective Extractive Distillation Agents Containing DMAA RelativeCompounds Ratios Volatilities__________________________________________________________________________Dimethylacetamide (DMAA) 1 6/5 1.1 1.2DMAA, Adipic acid (1/2).sup.2 (3/5).sup.2 2.5 2.9DMAA, Acetyl salicylic acid (1/2).sup.2 (3/5).sup.2 1.8 2.1DMAA, Azelaic acid (1/2).sup.2 (3/5).sup.2 3.0 2.1DMAA, Benzoic acid (1/2).sup.2 (3/5).sup.2 3.0 2.9DMAA, o-tert. Butyl benzoic acid (1/2).sup.2 (3/5).sup.2 2.0 1.9DMAA, Cinnamic acid (1/2).sup.2 (3/5).sup.2 2.3 1.3DMAA, Decanoic acid (1/2).sup.2 (3/5).sup.2 1.5 1.5DMAA, Dodecanedioic acid (1/2).sup.2 (3/5).sup.2 1.6 2.1DMAA, Glutaric acid (1/2).sup.2 (3/5).sup.2 2.0 2.1DMAA, Heptanoic acid (1/2).sup.2 (3/5).sup.2 3.3 3.1DMAA, Hexanoic acid (1/2).sup.2 (3/5).sup.2 2.1 2.1DMAA, 4-Hydroxybenzoic acid (1/2).sup.2 (3/5).sup.2 1.5 1.6DMAA, Itaconic acid (1/2).sup.2 (3/5).sup.2 2.2 2.4DMAA, Malic acid (1/2).sup.2 (3/5).sup.2 2.4 2.5DMAA, Neodecanoic acid (1/2).sup.2 (3/5).sup.2 1.6 1.8DMAA, Neopentanoic acid (1/2).sup.2 (3/5).sup.2 1.5 1.6DMAA, m-Nitrobenzoic acid (1/2).sup. 2 (3/5).sup.2 1.6 2.0DMAA, Octanoic acid (1/2).sup.2 (3/5).sup.2 1.6 2.1DMAA, Pelargonic acid (1/2).sup.2 (3/5).sup.2 1.7 2.1DMAA, Salicylic acid (1/2).sup.2 (3/5).sup.2 1.6 1.3DMAA, Sebacic acid (1/2).sup.2 (3/5).sup.2 1.3 1.6DMAA, o-Toluic acid (1/2).sup.2 (3/5).sup.2 1.9 1.9DMAA, m-Toluic acid (1/2).sup.2 (3/5).sup.2 2.1 1.9DMAA, p-Toluic acid (1/2).sup.2 (3/5).sup.2 1.7 1.5DMAA, 3,4,5-Trimethoxy benzoic acid (1/2).sup.2 (3/5).sup.2 1.9 1.5DMAA, Undecanoic acid (1/2).sup.2 (3/5).sup.2 1.6 2.2DMAA, Adipic acid, Diisobutyl ketone (1/3).sup.3 (2/5).sup.3 2.4 1.9DMAA, Acetyl salicylic acid, Acetophenone (1/3).sup.3 (2/5).sup.3 1.9 1.8DMAA, Azelaic acid, Adiponitrile (1/3).sup.3 (2/5).sup.3 2.6 2.4DMAA, Benzoic acid, Anisole (1/3).sup.3 (2/5).sup.3 1.3 1.6DMAA, o-tert. Butyl benzoic acid, Methyl salicylate (1/3).sup.3 (2/5).sup.3 2.0 1.7DMAA, Cinnamic acid, Butyl ether (1/3).sup.3 (2/5).sup.3 2.5 2.8DMAA, Decanoic acid, Cyclo hexanone (1/3).sup.3 (2/5).sup.3 1.7 1.8DMAA, Dodecanedioic acid, Diisobutyl ketone (1/3).sup.3 (2/5).sup.3 1.4 1.4DMAA, Glutaric acid, Methyl isoamyl ketone (1/3).sup. 3 (2/5).sup.3 1.9 2.7DMAA, Heptanoic acid, Ethyl benzoate (1/3).sup.3 (2/5).sup.3 2.6 2.1DMAA, Hexanoic acid, Methyl benzoate (1/3).sup.3 (2/5).sup.3 1.5 1.2DMAA, 4-Hydroxybenzoic acid, Ethylene glycol diacetate (1/3).sup.3 (2/5).sup.3 1.6 1.3DMAA, Itaconic acid, 2-Octanone (1/3).sup.3 (2/5).sup.3 1.7 2.9DMAA, Malic acid, Diethylene glycol dibenzoate (1/3).sup.3 (2/5).sup.3 1.5 1.2DMAA, Neodecanoic acid, Isophorone (1/3).sup.3 (2/5).sup.3 1.8 1.5DMAA, Neopentanoic acid, 2-Heptanone (1/3).sup.3 (2/5).sup.3 1.3 1.4DMAA, m-Nitrobenzoic acid, Hexyl acetate (1/3).sup.3 (2/5).sup.3 1.7 1.3DMAA, p-Nitrobenzoic acid, Acetophenone (1/3).sup.3 (2/5).sup.3 1.1 1.1DMAA, Octanoic acid, Butyl benzoate (1/3).sup.3 (2/5).sup.3 1.7 1.6DMAA, Pelargonic acid, Benzyl benzoate (1/3).sup.3 (2/5).sup.3 1.1 1.2DMAA, Salicylic acid, Ethyl salicylate (1/3).sup.3 (2/5).sup.3 1.1 1.1DMAA, Sebacic acid, Ethyl butyl ketone (1/3).sup.3 (2/5).sup.3 2.1 1.3DMAA, o-Toluic acid, Diethylene glycol dimethyl ether (1/3).sup.3 (2/5).sup.3 1.7 1.7DMAA, m-Toluic acid, Diethylene glycol diethyl ether (1/3).sup.3 (2/5).sup.3 1.6 1.6DMAA, p-Toluic acid, Dipropylene glycol dibenzoate (1/3).sup.3 (2/5).sup.3 1.7 1.5DMMA, 3,4,5-Trimethoxybenzoic acid, Ethyl phenyl (1/3).sup.3 (2/5).sup.3 1.6 1.5acetateDMMA, Undecanoic acid, 2-Hydroxy acetophenone (1/3).sup.3 (2/5).sup.3 1.1 1.2__________________________________________________________________________
TABLE 3__________________________________________________________________________Data From Run Made In Rectification Column Time, Weight % Weight % RelativeAgent Column hrs. Ketone Formic acid Volatility__________________________________________________________________________33% DMAA, Overhead 3/4 98.7 1.3 3.533% Heptanoic acid, Bottoms 10.3 89.733% Methyl benzoate33% DMAA, Overhead 1.5 90.9 9.1 2.933% Heptanoic acid, Bottoms 4 9633% Methyl benzoate__________________________________________________________________________
DETAILED DESCRIPTION OF THE INVENTION
We have discovered that dimethylformamide (DMFA) and dimethylacetamide (DMAA), either singly or admixed with other high boiling organic compounds, will effectively increase the relative volatility of 4-methyl-2-pentanone to formic acid and permit the separation of pure 4-methyl-2-pentanone from formic acid by rectification when employed as the agent in extractive distillation. Table 1 lists the mixtures containing DMFA in the proportions that we have found to be effective. Table 2 lists the mixtures containing DMAA that are effective. The data in Tables 1 and 2 were obtained in a vapor-liquid equilibrium still. In each case, the starting mixture was 35% 4-methyl-2-pentanone, 65% formic acid. The ratios are the parts by weight of extractive agent used per part of 4-methyl-2-pentanone-formic acid mixture. The relative volatilities are listed for each of the two ratios employed. The compounds which are effective when used in mixtures with DMAA are adipic acid, acetyl salicylic acid, azelaic acid, benzoic acid, o-tert, butyl benzoic acid, cinnamic acid, decanoic acid, dodecanedioic acid, glutaric acid, heptanoic acid, hexanoic acid, 4 -hydroxybenzoic acid, itaconic acid, malic acid, neodecanoic acid, neopentanoic acid, m-nitrobenzoic acid, octanoic acid, pelargonic acid, salicylic acid, sebacic acid, o-toluic acid, m-toluic acid, p-toluic acid, 3,4,5-trimethyoxy benzoic acid, undecanoic acid, diisobutyl ketone, acetophenone, adiponitrile, anisole, methyl salicylate, butyl ether, cyclohexanone, methyl isoamyl ketone, ethyl benzoate, methyl benzoate, ethylene glycol diacetate, 2-octanone, diethylene glycol dibenzoate, isophorone, 2-heptanone, hexyl acetate, butyl benzoate, benzyl benzoate, ethyl salicylate, ethyl butyl ketone, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol dibenzoate, ethyl phenyl acetate and 2-hydroxy-acetophenone. The compounds which are effective when used in mixtures with DMFA are hexanoic acid, heptanoic acid, itaconic acid, neodecanoic acid, octanoic acid, pelargonic acid, methyl benzoate, ethyl benzoate, 2-octanone, benzyl acetate and butyl benzoate.
The two relative volatilities shown in Tables 1 and 2 correspond to the two different ratios investigated. For example, in Table 2, one half part of DMAA plus one half part of acetyl salicylic acid with one part of the 4-methyl-2-pentanone-formic acid mixture gives a relative volatility of 1.8; 3/5 parts of DMAA plus 3/5 parts of acetyl salicylic acid give 2.1. One third parts each of DMAA, azelaic acid and adiponitrile with one part of the 4-methyl-2-pentanone-formic acid mixture gives a relative volatility of 2.6; with 2/5 parts, these three give 2.4. In every example in Tables 1 and 2, the starting material is the 4-methyl-2-pentanone-formic acid mixture which possesses a relative volatility of 1.3.
Three of the agents, DMAA plus heptanoic acid plus methyl benzoate, listed in Table 2 and whose relative volatility had been determined in the vapor-liquid equilibrium still, were then evaluated in a glass perforated plate rectification column possessing 5.3 theoretical plates and the results listed in Table 3. The data in Table 3 was obtained in the following manner. The charge was 100 grams of 4-methyl-2-pentanone and 100 grams of formic acid and after a half hour of operation in the 5.3 theoretical plate column to establish equilibrium, DMAA, heptanoic acid and methyl benzoate at 95° C. and 38 ml/min. were pumped in. The rectification was continued with sampling of the overhead and bottoms after 45 minutes. The analyses are shown in Table 3 and were: overhead 98.7% 4-methyl-2-pentaone, 1.3% formic acid and bottoms was 10.3% 4-methyl-2-pentanone, 89.7% formic acid which gives a relative volatility of 4-methyl-2-pentanone to formic acid of 3.5. After 1.5 hours of continuous operation, overhead and bottoms were again sampled and analysed. The overhead was 90.9% 4-methyl-2-pentanone, 9.1% formic acid and the bottoms was 4% 4-methyl-2-pentanone, 96% formic acid which is a relative volatility of 2.9. This indicates that the relative volatility has been enhanced and separation accomplished by extractive distillation.
THE USEFULNESS OF THE INVENTION
The usefulness or utility of this invention can be demonstrated by referring to the data presented in Tables 1, 2 & 3. All of the successful extractive distillation agents show that 4-methyl-2-pentanone and formic acid can be separated from each other by means of distillation in a rectification column and that the ease of separation as measured by relative volatility is considerable. Without these extractive distillation agents, the relative volatility would be only 1.3 and separation by rectification would be difficult. The data also show that the most attractive agents will operate at a boilup rate low enough to make this a useful and efficient method of recovering high purity 4-methyl-2-pentanone and formic acid from any mixture of these two close boiling compounds. The stability of the compounds used and the boiling point difference is such that complete recovery and recycle is obtainable by a simple distillation and the amount required for make-up is small.
WORKING EXAMPLES
Example 1
Eighteen grams of 4-methyl-2-pentanone, 33 grams of formic acid and 50 grams of DMFA were charged to a vapor-liquid equilibrium still and refluxed for 12 hours. Analysis indicated a vapor composition of 39% 4-methyl-2-pentanone, 61% formic acid and a liquid composition of 24.1% 4-methyl-2-pentanone, 75.9% formic acid which is a relative volatility of 2.0. Ten grams of DMFA were added and refluxing continued for another 11 hours. Analysis indicated a vapor composition of 46.2% 4-methyl-2-pentanone, 53.8% formic acid, a liquid composition of 31.3% 4-methyl-2-pentanone, 68.7% formic acid which is a relative volatility of 1.9.
Example 2
Fifty grams of the 4-methyl-2-pentanone-formic acid mixture, 25 grams of DMAA and 25 grams of acetyl salicylic acid were charged to the vapor-liquid equilibrium still and refluxed for 16 hours. Analysis indicated a vapor composition of 16.3% 4-methyl-2-pentanone, 83.7% formic acid and a liquid composition of 9.8% 4-methyl-2-pentanone, 90.2% formic acid which is a relative volatility of 1.8. Five grams of DMAA and five grams of acetyl salicylic acid were added and refluxing continued for another eleven hours. Analysis indicated a vapor composition of 12.9% 4-methyl-2-pentanone, 87.1% formic acid and a liquid composition of 6.5% 4-methyl-2-pentanone, 93.5% formic acid which is a relative volatility of 2.1.
Example 3
Fifty grams of the 4-methyl-2-pentanone-formic acid mixture, 17 grams of DMAA, 17 grams of azelaic acid and 17 grams of adiponitrile were charged to the vapor-liquid equilibrium still and refluxed for 12 hours. Analysis indicated a vapor composition of 25.5% 4-methyl-2-pentanone, 74.5% formic acid and a liquid composition of 11.8% 4-methyl-2-pentanone, 88.2% formic acid which is a relative volatility of 2.6. Three grams each of DMAA, azelaic acid and adiponitrile were added and refluxing continued for another nine hours. Analysis indicated a vapor composition of 22.4% 4-methyl-2-pentanone, 77.6% formic acid and a liquid composition of 10.7% 4-methyl-2-pentanone, 89.3% formic acid which is a relative volatility of 2.4.
Example 4
A glass perforated plate rectification column was calibrated with methyl cyclohexane and toluene which possesses a relative volatility of 1.46 and found to have 5.3 theoretical plates. A solution comprising 100 grams of 4-methyl-2-pentanone and 100 grams of formic acid was placed in the stillpot and heated. When refluxing began, an extractive agent comprising 33% DMAA, 33% heptanoic acid and 33% methyl benzoate was pumped into the column at a rate of 38 ml/min. The temperature of the extractive agent as it entered the column was 95° C. After establishing the feed rate of the extractive agent, the heat input to the 4-methyl-2-pentanone and formic acid in stillpot was adjusted to give a total reflux rate of 40 ml/min. After 45 minutes of operation, the overhead and bottoms samples of approximately two ml. were collected and analysed by gas chromatography. The overhead analysis was 98.7% 4-methyl-2-pentanone and 1.3% formic acid. The bottom analysis was 10.3% 4-methyl- 2-pentanone and 89.7% formic acid. Using these compositions in the Fenske equation, with the number of theoretical plates in the column being 5.3, gave an average relative volatility of 3.5 for each theoretical plate. After 1.5 hours of continuous operation, the overhead analysis was 90.7% 4-methyl-2-pentanone, 9.1% formic acid, the bottoms analysis was 4% 4-methyl-2-pentanone and 96% formic acid which is a relative volatility of 2.9. These data are presented in Table 3. | 4-Methyl-2-pentanone cannot be easily separated from formic acid by distillation because of the closeness of their boiling points. 4-Methyl-2-pentanone can be readily removed from formic acid by extractive distillation using dimethylamides. Typical effective agents are dimethylformamide; dimethylacetamide and acetyl salicyclic acid; dimethylacetamide, heptanoic acid and methyl benzoate. | 2 |
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to novel cyclopropanoid compositions useful in the synthesis of pyrethroids and to methods of preparing these compositions. The compounds of the invention have the structure ##STR4## where R' is --CH 3 or --CH 2 CH 3 and A is either --H or A, B represents a group having a carbon atom in common with the cyclopropanoid ring, the A, B group having the formula --(CH 2 ) n -- (n=3, 4, or 5) or --(CH 2 ) 2 --Y--(CH 2 ) 2 -- (Y=NCH 3 , O, or S). When A is --H, B is selected from the group consisting of: ##STR5##
In accordance with the method of the present invention, these compounds, as well as other pyrethroid intermediates, can be manufactured from aldehydes in a two step process: ##STR6##
Alicyclic ketones of the formula RR"CO, wherein R,R"=--(CH 2 ) n --(n=3, 4, or 5) or R,R"=--(CH 2 ) 2 --Y--(CH 2 ) 2 --(Y=NCH 3 , O, or S), can also be used as starting materials in lieu of the aldehyde (RCHO).
Although the experimental conditions for a Knoevenagel condensation vary from one starting compound to the next, one can examine the literature for the exact procedure to be followed for a given starting material. An excellent and lengthy review [including a list of various aldehydes and ketones which have been successfully condensed with methyl or ethyl cyanoacetate (listed in Table VII of the review)] can be found in Organic Reactions, 15, pp. 204-599 (1967).
(2) Description of the Prior Art
Because of their low mammalian toxicity, high insecticidal activity, and biodegradability, the pyrethroids have proved quite useful for the control of insect pests. A study of the literature reveals that in the past decade various routes have been developed for the synthesis of these compounds. A collection of a number of methods of preparing certain ester derivatives of trans-chrysanthemic acid and the related synthetic pyrethroids can be found in "Synthetic Pyrethroids", ACS Symposium Series 42, M. Elliott, Ed., American Chemical Society, Washington, D.C., 1977, pp. 45-54, 116-136; and, "The Total Synthesis of Natural Products", Vol. 2, J. ApSimon, Ed., Wiley, New York, 1973, pp. 49-58. A survey of a number of syntheses of pyrethroid acids is reported in Angewandte Chemie, Internat. Ed. Engl., 20, 703-722 (1981).
Of particular interest to the present application are the methods disclosed by Krief et al. and by Annen et al. ##STR7## Reference: A. Krief, DOS 2,615,160 (1976), Roussel-Uclaf; M. J. Devos, L. Hevesi, P. Bayet, and A. Krief, Tetrahedron Lett., 3911 (1976). ##STR8## Reference: K. Annen, et al, Chem. Ber. 111. 3094-3104 (1978).
The Krief et al. process utilizes a phosphorane [(CH 3 ) 2 C═PPh 3 ] to generate a three-membered ring. Phosphorane reagents are very costly and require one equivalent of a strong base such as n-butyllithium to generate. In addition, phosphoranes must be synthesized in the absence of air and protic solvents (even traces of moisture rapidly destroy them); and therefore this type of process is highly unsuitable for an industrial scale-up. Moreover, the Krief cyclization yields a product which can be used to prepare the acid component of only trans pyrethroids whereas, as illustrated below, the method of the present invention results in either the cis-stereoisomer [which often exhibits greater insecticidal activity--e.g., See: M. Elliott, A. W. Farnum, N. F. Janes, P. H. Needham, and D. A. Pulman, Pesticide Sci., 6, 537 (1975)], or the trans stereoisomer. More significantly, Krief et al. utilized their cyclization with only a few specific compounds, such as those having the structure RCH═CHCO 2 R'. In sharp contrast, the method of the present invention failed to yield any cyclopropanoids using RCH═CHCO 2 R' (R=CH 3 or C 6 H 5 ) and (CH 3 ) 2 CHNO 2 (2-nitropropane) in the presence of base in refluxing alcohol.
Annen et al., utilizes a nitro compound and unsaturated cyanoesters similar to those used in the method of the present invention in order to generate cyclopropanoids. However, these are many significant differences between the Annen et al. procedure and the present method:
Annen's cyclization step, which is preceded by a Michael reaction, utilizes a nitro leaving group bonded to a primary (1°) carbon: ##STR9## The intermediate formed by the Michael reaction in the method of the present invention has the leaving group at a tertiary (3°) center: ##STR10## Due chiefly to steric factors, one would expect the ring closure of this latter structure to be much less favorable (if it proceeds at all) than for the similar process involving Annen's (1°) structure. Any basic textbook in organic chemistry indicates that nucleophilic substitution at a 1° carbon is much faster than at a 3° center. For example, the reaction of CH 3 CH 2 Br with I.sup.θ is 1,000 times faster than that between (CH 3 ) 3 C--Br and I.sup.θ. [Reference: Morrison and Boyd, "Organic Chemistry," 3rd Edition, p. 465]. Indeed, the major reaction pathway when nucleophiles interact with 3° halides is often elimination (to yield an alkene) rather than substitution [Reference: Morrison and Boyd, "Organic Chemistry," 3rd Ed., p. 485].
Nothwithstanding these theoretical considerations, the cyclization reaction of the present invention proceeds under considerably milder conditions than those employed by Annen et al. Annen employs metal alcohol at 100° C. (which requires a pressure reactor since the boiling point of CH 3 OH is 65° C.) and excess base accompanied by a very large excess of nitromethane. The method of the present invention procedes readily at 65° C. (refluxing methanol) or 78° C. (refluxing ethanol) and requires only a stoichiometric quantity of base and 2-nitropropane.
Annen et al. shows that his procedure was used successfully to convert ##STR11## in 19% yield. The cyclizatin method of the present invention, using (CH 3 ) 2 CHNO 2 , failed when applied to ##STR12## (R'=CH 3 or CH 2 CH 3 ). The fact that this failure is not simply due to the steric factors involved in forming a fully-substituted ring is illustrated by the fact that a sterically complex cyclopropanoid was formed readily (in less than 5 hours) and in high yield (greater than 70%) using the method of the present invention: ##STR13##
It appears that the process of Annen et al. is most successful when applied to complex steroidal systems and gives poor yields when applied to relatively simple systems. The method disclosed herein, in contrast, proceeds readily in 70-95% yields with a variety of substrates, both simple and complex.
BRIEF DESCRIPTION OF THE INVENTION
As stated previously, the present invention discloses a series of novel cyclopropanoid compositions together with methods of preparing these compositions and related compounds. The compounds of the invention have the structure: ##STR14## where R' is methyl or ethyl and A is either hydrogen or A and B together represent a group having a carbon atom in common with the cyclopropanoid ring and having the formula --(CH 2 ) n -- (n=3, 4, or 5) or --(CH 2 ) 2 --Y--(CH 2 ) 2 where (Y=NCH 3 , O or S). Two such spirocyclic compounds are ethyl 1'-cyano-3',3'-dimethyl-spiro(4-methyl-4-azacyclohexane-1,2'-cyclopropane)-1'-carboxylate and ethyl 1'-cyano-3',3'-dimethyl-spiro(cyclopentane-1,2'-cyclopropane)-1'-carboxylate ##STR15## When A and B are not part of such a spiro group, A is --H and B can be any of the following alkyl or aryl substituents: phenyl, ethyl, (2'-thienyl), (2'-furyl), (3'-pyridyl), (2'-pyridyl), o-chlorophenyl, m-methoxyphenyl, p-tolyl, (9'-decen-1'-yl), (1'-methyl-2'-pyrrolyl), m-nitrophenyl, (3'-cyclohexen-1'-yl), 1'-naphthyl; 2',4'-dichlorophenyl; and isobutyl.
With an aldehyde or alicyclic ketone starting material, the products of the invention can be generated in a two-step procedure: ##STR16## The base utilized in the Step 2 reaction can be an alkali metal alkoxide such as sodium methoxide or sodium ethoxide.
Examination by NMR revealed the cyclopropanoid products of the present invention to be formed as a single stereoisomer (neglecting optical isomerism)--one which after decarbalkoxylation could be a useful precursor to the acid component of cis-pyrethroids.
The aldehyde starting materials (RCHO) which can be utilized in the Step 1 reaction include those wherein R is an alkyl group containing between 1 and 10 carbon atoms inclusive. For example, the compound ##STR17## has been reported to give insecticidally-active esters [Drabek et al., DOS 2731033 (1978)], suggesting that R=isobutyl would be a desirable starting material.
Other satisfactory aldehydes include those wherein R is naphthyl, phenyl, or a benzenoid ring substituted at various positions with alkyl, halogen, nitro, or alkoxy substituents--provided that at least one of the ortho carbons of the benzene ring is substituted with a hydrogen atom (e.g., use of ethyl 2-cyano-3-(2',6'dichlorophenyl)-2-propenoate as a starting material resulted in an insignificant amount of (<10%) of a cyclopropanoid product). Alicyclic rings, including those possessing unsaturation ##STR18## and heterocyclic residues possessing N, O, and/or S atoms in the ring--such as furan, thiophene, pyridine, pyrrole, and indole heterocyclic residues--can also be utilized.
Particularly useful aldehydes include benzaldehyde, propionaldehyde, 2-thiophenecarboxyaldehyde, 2-furaldehyde, 3-pyridinecarboxaldehyde, 2-pyridinecarboxaldehyde, o-chlorobenzaldehyde, m-methoxybenzaldehyde, p-tolualdehyde, 10-undecenal, N-methylpyrrole-2-carboxaldehyde (proceeds very slowly), m-nitrobenzaldehyde, 3-cyclohexenecarboxaldehyde, 1-naphthaldehyde, 2,4-dichlorobenzaldehyde, and isovaleraldehyde.
Although a wide range of C 1 to C 10 alkyl groups can be employed, it has been found that aliphatic alpha, beta-unsaturated aldehydes are not useful starting materials.
Ketones of the formula ##STR19## can be utilized as starting materials in the Knoevenagel (Step 1) reaction. However, with the exception of alicyclic ketones the cyclization step proceeds very poorly, presumably for steric reasons. For example, attempts to form cyclopropanoid products from ##STR20## resulted in ˜10% crude yield of a mixture of products after reaction times of either 2 or 8 hours at reflux.
Attempts to form cyclopropanoid products from ##STR21## afforded after 21/2 hours at reflux the following results: greater than 30% of the product mixture was a non-distillable resinous material; the distilled product (less than 70% yield) contained 20% 4-phenyl-2-butanone and 60% starting cyanoester--the remainder of the distillate could be cyclopropanoid, but was not fully characterized. Longer reaction times merely gave more non-distillable resinous material. In cyclization attempts using ##STR22## after 31/2 hours at reflux, greater than 50% of the product isolated was non-distillable resinous material and the distillate contained mainly (at least one-half) starting material, along with ˜20% acetophenone ##STR23## and other unidentified impurities.
Interestingly enough alicyclic ketones such as cyclopentanone and 1-methyl-4-piperidone could be successfully used to prepare, respectively, ##STR24## The cyclization reaction to prepare the latter (heterocyclic) compound was complete in approximately 5 hours in refluxing ethanol, whereas the similar reaction involved in the preparation of the former was much slower--being ˜50% complete after 6 hours in refluxing ethanol.
Alicyclic compounds useful in the reaction have the formulae RR"C=O, where R, R"=--(CH 2 ) n -- (n=3, 4, or 5), or R,R"=--(CH 2 ) 2 --Y--(CH 2 ) 2 -- (Y=O, NCH 3 , or S).
The novel method of the present invention comprises the Step 2 cyclization reaction, i.e., the reaction of a cyanoester with 2-nitropropane in the presence of an alkoxide base ##STR25## wherein R 1 and R 2 are carbon, R' is methyl or ethyl, A and B represent a group having the formula --(CH 2 ) n -- or --(CH 2 ) 2 --Y-- (CH 2 ) 2 --, n=3, 4, or 5, Y is NCH 3 , O, or S, and R can be selected from the group consisting of alkyl, haloalkyl, alkenyl, haloalkenyl, cycloalkyl, carboalkoxy, heterocycles possessing N, S, and/or O atoms, cycloalkyl, cycloalkenyl, phenyl and substituted phenyl, bicycloalkyl, phenylalkyl, hydroxyalkyl, aminoalkyl, and thioalkyl, provided that when R is alkenyl, R is not conjugated with R 1 and R 2 , and when R is a substituted phenyl group, at least one of the ortho carbons of said phenyl group is bonded to hydrogen.
The base utilized can be an alkali metal alkoxide such as sodium methoxide or sodium ethoxide, or it can be an alkali metal carbonate such as sodium carbonate or potassium carbonate. Indeed, any base that can dissolve in alcohol to generate a small amount of alkoxide should be suitable for this reaction. The solvent (R'OH) is preferably methyl alcohol or ethyl alcohol, although other simple alcohols would be equally useful (e.g., n-propyl or isopropyl alcohol).
The reaction proceeds in refluxing alcohol solvent. Under these conditions and in order to achieve optimum yields, reaction times in excess of two hours are preferred, depending on the nature of the reactants. For example, the cyclization reaction involving ##STR26## proceeded very slowly (requiring two days in refluxing ethanol), but resulted in a satisfactory product.
In order to prepare the desired acid component of pyrethroids, the cyclopropane-cyanoester is first converted to a nitrile product by means of either of the following methods: ##STR27## It has been found (for A=H, B=C 6 H 5 ) that some (˜10-15%) ring-opened material is generated in the one-step process, Method A. Method B (the two-step procedure) is generally preferred in that little or no such ring-opened materials are formed. Another two-step method which could be employed for the conversion is a saponification-decarboxylation process similar to Method B, but employing bicarbonate and 1,3-propanediol at reflux for the second step.
DETAILED DESCRIPTION
The following examples illustrate in greater detail the practice of the present invention, more specifically:
(A) the formation of several intermediate compounds of the formula
______________________________________ ##STR28##
______________________________________ -1, R = C.sub.6 H.sub.5 ; R' = CH.sub.2 CH.sub.3 Example I -2, R = C.sub.6 H.sub.5 ; R' = CH.sub.3 Example II ##STR29## Example III ##STR30## Example IV -5, R = (CH.sub.3).sub.2 CHCH.sub.2; R' = CH.sub.2 CH.sub.3 Example V ##STR31## Example X ##STR32## Example XIII______________________________________
(B) the formation of intermediates
______________________________________ ##STR33## Example VI ##STR34## Example VII______________________________________
(C) the formation of cyclopropanoids of the formula
______________________________________ ##STR35##
______________________________________ --10, R = C.sub.6 H.sub.5 ; R' = CH.sub.2 CH.sub.3 Example VIII --11, R = C.sub.6 H.sub.5 ; R' = CH.sub.3 Example IX ##STR36## Example X ##STR37## Example XI --14, R = (CH.sub.3).sub.2 CHCH.sub.2; R' = CH.sub.2 CH.sub.3 Example XII ##STR38## Example XIII ##STR39## Example XVII______________________________________
(D) the formation of cyclopropanoids of the formula
______________________________________ ##STR40##
______________________________________ --17, R = C.sub.6 H.sub.5 ; Y,Z = CN,H (mixtures of Examples XIV &stereoisomers) XVI --18, R = C.sub.6 H.sub.5 ; Y = COOH; Z = CN Example XV ##STR41## Example XVII ##STR42## Example XVIII______________________________________
EXAMPLE I
Preparation of (E)-Ethyl 2-Cyano-3-phenyl-2-propenoate (1)
A mixture containing 4.0 mL (37.6 mmoles) of ethyl cyanoacetate, 3.95 g (37.2 mmoles) of benzaldehyde, 20 mg of β-alanine, and 1.00 mL of glacial acetic acid in 35 mL of benzene was heated at reflux for 3 hours with continuous azeotropic removal of water by means of a Dean-Stark trap. The product was isolated by cooling the mixture to room temperature, pouring it into 75 mL of 2:1 (v/v)1M aqueous NaOH:saturated brine, and extraction with ether. The organic extracts were washed with 75 mL of 2:1 (v/v) 1M aqueous NaOH:saturated brine, 10% aqueous sodium chloride solution, then were dried over anhydrous magnesium sulfate and subsequently filtered. Removal of the ether and benzene by evaporation at reduced pressure afforded 6.88 g (92% yield) of crystalline cyanoester 1: mp 49°-50° C.
EXAMPLE II
Preparation of (E)-Methyl 2-Cyano-3-phenyl-2-propenoate (2)
A mixture containing 2.0 mL (22.7 mmoles) of methyl cyanoacetate, 2.38 g (22.4 mmoles) of benzaldehyde, 18 mg of β-alanine, and 1.00 mL of glacial acetic acid in 35 mL of benzene was heated at reflux for 2 hours with continuous azeotropic removal of water by means of a Dean-Stark trap. The product was isolated as described in the procedure of Example I, affording 3.83 g (91% yield) of crystalline cyanoester 2: mp 90°-91° C.
EXAMPLE III
Preparation of (E)-Ethyl 2-Cyano-3-(2'-thienyl)-2-propenoate (3)
To a solution of 1.052 g (9.38 mmoles) of distilled 2-thiophenecarboxaldehyde (commercially available: Aldrich Chemical Co.) and 1.00 mL (9.4 mmoles) of ethyl cyanoacetate in 3.0 mL of dioxane at 0° C. (reaction flask kept in an ice-water bath) was added 0.04 mL of piperidine. This mixture was subsequently stirred at 0° C. for 15 minutes and at room temperature for 11 hours. The product was isolated by diluting the mixture with 20 mL of 1:1 (v/v) 1M aqueous NaOH:saturated brine and extraction with ether. The combined extracts were washed thoroughly with 25 mL portions of 10% aqueous sodium chloride, then were dried over anhydrous magnesium sulfate and subsequently filtered. Removal of the ether by evaporation at reduced pressure afforded 1.89 g (98% yield) of crystalline cyanoester 3: mp 92°-93.5° C. [reported mp: 93°-94° C., lit. reference: F. D. Popp and A. Catala, J. Org. Chem., 26, 2738 (1961)].
EXAMPLE IV
Preparation of (E)-Ethyl 2-Cyano-3-(3' -pyridyl)-2-propenoate (4)
A procedure described by B. C. McKusick, R. E. Heckert, T. L. Cairns, D. D. Coffman, and H. F. Mower [J. Am. Chem. Soc., 80, 2806 (1958)] was used to prepare this compound. A mixture of 3.037 g (28.3 mmoles) of 3-pyridinecarboxaldehyde (commercially available: Aldrich Chemical Co.), 3.00 mL (28.2 mmoles) of ethyl cyanoacetate, 0.10 mL (1.01 mmole) of piperidine, and 0.25 mL of glacial acetic acid in 20 mL of absolute ethanol was heated at reflux for 2 hours, after which 40 mL of water was added to this hot solution and the mixture was allowed to cool gradually to room temperature. The crystalline cyanoester 4 was collected by filtration and washed twice with 10 mL-portions of 2:1 (v/v) water:ethanol. Yield of 4: 3.64 g (64%); mp 124°-125° C.
EXAMPLE V
Preparation of (E)-Ethyl 2-Cyano-5-methyl-2-hexenoate (5)
To a mixture of 3.00 mL (28.0 mmoles) of isovaleraldehyde and 3.00 mL (28.1 mmoles) of ethyl cyanoacetate in 4.0 mL of glacial acetic acid was added a solution of 0.10 mL of piperidine in 1.0 mL of glacial acetic acid. This mixture was subsequently stirred at room temperature for 18 hours, after which the product was isolated by diluting the mixture with 50 mL of 10% aqueous sodium chloride and extraction with ether. The combined extracts were washed thoroughly with 50 mL portions of 10% aqueous NaCl, followed by washes with 50 mL of 1:1 (v/v) 1M aqueous NaOH:saturated brine and saturated brine. The organic extracts were then dried over anhydrous magnesium sulfate and subsequently filtered. Removal of the ether by evaporation at reduced pressure, followed by distillation, afforded 3.91 g (77% yield) of cyanoester 5: bp 78°-90° C. (bath temperature, 0.07 mm).
EXAMPLE VI
Preparation of Diethyl Benzylidenemalonate (8)
A mixture containing 3.0 mL (19.8 mmoles) of diethyl malonate, 2.0 mL (19.6 mmoles) of benzaldehyde, 0.10 mL of piperidine, and 65 mg of benzoic acid in 35 mL of benzene was heated at reflux for 6 hours with continuous azeotropic removal of water by means of a Dean-Stark trap. Isolation of the product in the manner described in the procedure of Example I, followed by fractional distillation, afforded 4.27 g (88% yield) of diester 8: bp 105°-140° C. (bath temperature, 0.10 mm). Subsequent treatment of diester 8 with 2-nitropropane and sodium ethoxide in ethanol at reflux, as described for the corresponding cyanoester 1 in Example VIII, failed to yield a cyclopropanoid product.
EXAMPLE VII
Preparation of Ethyl(1-Methyl-4-piperidylidene)-cyanoacetate (9)
A mixture containing 1.05 g (9.27 mmoles) of 1-methyl-4-piperidone (commercially available: Aldrich Chemical Co., 1.00 mL (9.4 mmoles) of ethyl cyanoacetate, and 148 mg of ammonium acetate in 35 mL of benzene was heated at reflux for 3 hours with continuous azeotropic removal of water by means of a Dean-Stark trap. The product was isolated by cooling the mixture to room temperature, pouring it into 30 mL of 2:1 (v/v) 1M aqueous NaOH:saturated brine, and extraction with ether. The organic extracts were washed with 10% aqueous sodium chloride solution, then were dried over anhydrous sodium sulfate and subsequently filtered. Removal of the ether and benzene by evaporation at reduced pressure afforded 1.46 g (76% yield) of cyanoester 9.
EXAMPLE VIII
Preparation of Ethyl 1-Cyano-2,2-dimethyl-3-phenylcyclopropanecarboxylate (10)
A mixture of 534 mg (2.65 mmoles) of cyanoester 1 (produced in accordance with Example I), 0.25 mL (2.78 mmoles) of 2-nitropropane, and 4.0 mL (2.60 mmoles of sodium ethoxide) of an 0.65M solution of sodium ethoxide (prepared from sodium metal and ethyl alcohol) in ethyl alcohol was stirred at room temperature for 10 minutes and subsequently heated at gentle reflux, protected from atmospheric moisture, for 3 hours. The product was isolated by cooling the mixture to room temperature, diluting it with 30 mL of 10% aqueous sodium chloride, and extraction with dichloromethane. The dichloromethane extracts were washed with 10% aqueous sodium chloride, dried over anhydrous magnesium sulfate, and filtered. Removal of the dichloromethane at reduced pressure, followed by evaporative distillation, [bath temperature: 125°-135° C. (0.05 mm)], afforded 620 mg (96% yield) of cyclopropanoid cyanoester 10. The presence of a single sharp peak (δ3.30) for the cyclopropyl H in 10 suggested the presence of only one stereoisomer (neglecting optical isomerism)--the phenyl and cyano substituents being cis, as shown by subsequent decarbalkoxylation results).
EXAMPLE IX
Preparation of Methyl 1-Cyano-2,2-dimethyl-3-phenylcyclopropanecarboxylate (11)
A mixture of 511 mg (2.73 mmoles) of cyanoester 2 (produced in accordance with Example II), 0.25 mL (2.78 mmoles) of 2-nitropropane, and 2.64 mmoles of sodium methoxide (prepared from 61 mg of sodium and methyl alcohol) in 4.0 mL of absolute methanol was stirred at room temperature for 10 minutes and subsequently heated at reflux, protected from atmospheric moisture, for 71/2 hours. The product was isolated as described in the procedure of Example VIII, affording 483 mg (77% yield) of cyclopropanoid cyanoester 11, stereochemically homogeneous as shown by NMR analysis: δ3.83 (singlet, CO 2 CH 3 ) and δ3.30 (singlet, cyclopropyl H).
EXAMPLE X
Preparation of Ethyl 1-Cyano-2,2-dimethyl-3-(o-chlorophenyl)-cyclopropanecarboxylate (12)
A mixture of 640 mg (2.7 mmoles) of (E)-ethyl 2-cyano-3-(o-chlorophenyl)-2-propenoate (6) (prepared from ethyl cyanoacetate and o-chlorobenzaldehyde using the procedure described in Example I for an analogous cyanoester), 0.25 mL (2.78 mmoles) of 2-nitropropane, 357 mg (2.6 mmoles) of anhydrous potassium carbonate, and 4.0 mL of absolute ethyl alcohol was heated at reflux for 3 hours. The product was isolated as described in the procedure of Example VIII, affording 664 mg (88% yield) of cyclopropanoid cyanoester 12, stereochemically homogeneous as shown by NMR analysis: δ3.22 (singlet, cyclopropyl H); bp: 122°-155° C. (bath temperature, 0.08 mm).
EXAMPLE XI
Preparation of Ethyl 1-Cyano-2-(2'-thienyl)-3,3-dimethylcyclopropanecarboxylate (13)
A mixture of 557 mg (2.69 mmoles) of cyanoester 3 (produced in accordance with Example III), 0.25 mL (2.78 mmoles) of 2-nitropropane, and 4.0 mL of an 0.65M solution of sodium ethoxide (prepared from sodium metal and ethyl alcohol) in ethyl alcohol was heated at reflux, protected from atmospheric moisture, for 9 hours. The product was isolated as described in the procedure of Example VIII, affording 524 mg (78% yield) of cyclopropanoid cyanoester 13: bp 120°-148° C. (bath temperature, 0.05 mm); sterochemically homogeneous as shown by NMR analysis (δ3.30, singlet, cyclopropyl H).
EXAMPLE XII
Preparation of Ethyl 1-Cyano-2,2-dimethyl-3-isobutylcyclopropanecarboxylate (14)
A mixture of 490 mg (2.70 mmoles) of cyanoester 5 (produced in accordance with Example V), 0.25 mL (2.78 mmoles) of 2-nitropropane, and 4.0 mL of an 0.65M solution of sodium ethoxide (prepared from sodium metal and ethyl alcohol) in absolute ethyl alcohol was heated at reflux, protected from atmospheric moisture, for 31/2 hours. The product was isolated as described in the procedure of Example VIII, affording 575 mg (95% yield) of cyclopropanoid cyanoester 14: bp 80°-102° C. (bath temperature, 0.05 mm).
EXAMPLE XIII
Preparation of Ethyl 1-Cyano-2,2-dimethyl-3-(p-methylphenyl)cyclopropanecarboxylate (15)
A mixture of 576 mg (2.68 mmoles) of (E)-ethyl 2-cyano-3-(p-methylphenyl)-2-propenoate (7) [prepared from ethyl cyanoacetate and p-tolualdehyde (p-methylbenzaldehyde) using the procedure described in Example I for an analogous cyanoester], 0.25 ml (2.78 mmoles) of 2-nitropropane, 398 mg (2.88 mmoles) of anhydrous potassium carbonate, and 2.0 ml of absolute ethanol was heated at reflux for 7 hours. The product was isolated as described in the procedure of Example VIII, affording 511 mg (74% yield) of cyclopropanoid cyanoester 15: bp: 155°-183° C. (bath temperature, 0.15 mm).
EXAMPLE XIV
Preparation of 2,2-Dimethyl-3-phenylcyclopropanecarbonitrile (17)
A mixture of 234 mg (0.96 mmole) of cyclopropanoid cyanoester 10 (produced in accordance with Example VIII), 174 mg (2.1 mmoles) of sodium bicarbonate, and 35 mg of water in 2.0 mL of 1,3-propanediol was heated at reflux, protected from atmospheric moisture, for 45 minutes. The product was isolated by diluting the cooled mixture with 25 mL of saturated brine and extraction with ether. The ether extracts were washed in successive order with 20 mL of 1:1 (v/v) 1M aqueous NaOH:saturated brine and 20 mL of 10% aqueous sodium chloride, dried over anhydrous magnesium sulfate, and filtered. Removal of the ether by evaporation at reduced pressure afforded 157 mg (95% yield) of nitrile 17 as a mixture of cis and trans stereoisomers, subsequently shown by NMR analysis (vinyl H absorption at approximately 5.0δ) to be accompanied by a minor amount (˜10-15%) of ring-opened by-product.
EXAMPLE XV
Preparation of 1-Cyano-2,2-dimethyl-3-phenylcyclopropanecarboxylic Acid (18)
A mixture of 147 mg (0.60 mmole) of cyclopropanoid cyanoester 10 (produced in accordance with Example VIII), 88 mg (0.64 mmole) of anhydrous potassium carbonate, 0.50 mL of water, and 2.0 mL of methyl alcohol was heated at reflux for 20 minutes. The product was isolated by cooling the mixture to room temperature, cautiously acidifying it by addition of 2 mL of 2M aqueous HCl, subsequent dilution with 20 mL of saturated brine, and extraction with ether. The ether extracts were washed with saturated brine, then dried over anhydrous magnesium sulfate and subsequently filtered. Removal of the ether by evaporation at reduced pressure afforded 110 mg (85% yield) of cyanoacid 18, which was immediately decarboxylated in accordance with Example XVI.
EXAMPLE XVI
Preparation of cis and trans-2,2-Dimethyl-3-phenylcyclopropanecarbonitrile (17)
A mixture of 105 mg (0.49 mmol) of cyanoacid 18 (produced in accordance with Example XV), 85 mg (1.0 mmole) of NaHCO 3 , 18 mg. of water, and 1.0 mL of 1,3-propanediol was heated at reflux, protected from atmospheric moisture, for 45 minutes. The product was isolated as described in the procedure of Example XIV, affording 66 mg (79% yield) of nitrile 17 as a mixture of cis and trans stereoisomers. In contrast to the product isolated in Example XIV, no ring-opened nitrile could be detected by NMR analysis. The trans stereoisomer was characterized by two singlets on its NMR spectrum at δ0.90 and 1.51 (two methyls), whereas the corresponding absorptions for the cis stereoisomer were δ1.17 and 1.35.
EXAMPLE XVII
Preparation of cis- and trans-2,2-Dimethyl-3-(p-methylphenyl)cyclopropanecarbonitrile (19)
A mixture of 222 mg (0.97 mmole) of cyanoacid 16 [prepared in quantitative yield from cyanoester 15 using the procedure described in Example XV for an analogous compound], 127 mg (1.5 mmoles) of sodium bicarbonate, 170 mg (4.0 mmoles) of lithium chloride, and 72 mg (4.0 mmoles) of water in 2.00 ml of dimethyl sulfoxide was heated at 165° C. (external oil bath temperature), while being protected from atmospheric moisture for 18 hours. The product was isolated as described in the procedure of Example XIV, affording 147 mg (82% yield) of nitrile 19 as a 1:1 mixture of cis and trans stereoisomers.
NOTE: Attempts to decarbalkoxylate (i.e., 15→19 directly) cyanoester 15 using the procedure described in Example XIV gave low yields of the desired product (19) and much ring-opened material. Alternatively, an attempt to decarboxylate (i.e., 16→19) cyanoacid 16 in 1,3-propanediol using a procedure similar to that described in Example XVI gave predominately the cis stereoisomer of nitrile 19.
EXAMPLE XVIII
Preparation of Ethyl 1'-Cyano-3',3'-dimethyl-spiro(4-methyl-4-azacyclohexane-1,2'-cyclopropane)-1'-carboxylate (20)
A mixture of 567 mg (2.72 mmoles) of cyanoester 9 (produced in accordance with Example VII), 0.25 mL (2.78 mmoles) of 2-nitropropane, and 4.0 mL of an 0.65M solution of sodium ethoxide (prepared from sodium metal and ethyl alcohol) in absolute ethyl alcohol was heated at reflux, protected from atmospheric moisture, for 5 hours. The product was isolated as described in the procedure of Example VIII, affording 485 mg (71% yield) of cyclopropanoid cyanoester 20: bp 120°-150° C. (bath temperature, 0.05 mm). | Cyclopropanoid cyanoesters of the formula: ##STR1## where R' is --CH 3 or --CH 2 CH 3 , and A is (a) --H, or
(b) A, B represents an aliphatic group joined to a carbon atom on the cyclopropanoid ring, thereby forming a spiro group, A, B being selected from structures having the formula:
(i) --(CH 2 ) n --, wherein n=3, 4, or 5, and
(ii) --(CH 2 ) 2 --Y--(CH 2 ) 2 --, wherein Y is NCH 3 , O, or S); and,
when A is --H, B is selected from the group consisting of: ##STR2## are disclosed. These compositions are useful in the synthesis of pyrethroids. A process for synthesis of cyclopropanoid cyanoesters by reacting 2-nitropropane with cyanoesters of the general formula: ##STR3## is also disclosed and claimed. | 2 |
[0001] This application is a divisional of pending U.S. application Ser. No. 10/145,206 filed May 13, 2002, related to U.S. provisional application No. 60/290,196, filed May 11, 2001, which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] After years of study in necrosis of tumors, tumor necrosis factors (TNFs) α and β were finally cloned in 1984. The ensuing years witnessed the emergence of a superfamily of TNF cytokines, including fas ligand (FasL), CD27 ligand (CD27L), CD30 ligand (CD30L), CD40 ligand (CD40L), TNF-related apoptosis-inducing ligand (TRAIL, also designated AGP-1), osteoprotegerin binding protein (OPG-BP or OPG ligand), 4-1BB ligand, LIGHT, APRIL, and TALL-1. Smith et al. (1994), Cell 76: 959-962; Lacey et al. (1998), Cell 93: 165-176; Chichepotiche et al. (1997), J. Biol. Chem. 272: 32401-32410; Mauri et al. (1998), Immunity 8: 21-30; Hahne et al. (1998), J. Exp. Med. 188: 1185-90; Shu et al. (1999), J. Leukocyte Biology 65: 680-3. This family is unified by its structure, particularly at the C-terminus. In addition, most members known to date are expressed in immune compartments, although some members are also expressed in other tissues or organs, as well. Smith et al. (1994), Cell 76: 959-62. All ligand members, with the exception of LT-α, are type II transmembrane proteins, characterized by a conserved 150 amino acid region within C-terminal extracellular domain. Though restricted to only 20-25% identity, the conserved 150 amino acid domain folds into a characteristic β-pleated sheet sandwich and trimerizes. This conserved region can be proteolytically released, thus generating a soluble functional form. Banner et al. (1993), Cell 73: 431-445.
[0003] Many members within this ligand family are expressed in lymphoid enriched tissues and play important roles in the immune system development and modulation. Smith et al. (1994). For example, TNFα is mainly synthesized by macrophages and is an important mediator for inflammatory responses and immune defenses. Tracey & Cerami (1994), Ann. Rev. Med. 45: 491-503. Fas-L, predominantly expressed in activated T cell, modulates TCR-mediated apoptosis of thymocytes. Nagata, S. & Suda, T. (1995) Immunology Today 16:39-43; Castrim et al. (1996), Immunity 5: 617-27. CD40L, also expressed by activated T cells, provides an essential signal for B cell survival, proliferation and immunoglobulin isotype switching. Noelle (1996), Immunity 4:415-9.
[0004] The cognate receptors for most of the TNF ligand family members have been identified. These receptors share characteristic multiple cysteine-rich repeats within their extracellular domains, and do not possess catalytic motifs within cytoplasmic regions. Smith et al. (1994). The receptors signal through direct interactions with death domain proteins (e.g. TRADD, FADD, and RIP) or with the TRAF proteins (e.g. TRAF2, TRAF3, TRAF5, and TRAF6), triggering divergent and overlapping signaling pathways, e.g. apoptosis, NF-κB activation, or JNK activation. Wallach et al. (1999), Annual Review of Immunology 17: 331-67. These signaling events lead to cell death, proliferation, activation or differentiation. The expression profile of each receptor member varies. For example, TNFR1 is expressed on a broad spectrum of tissues and cells, whereas the cell surface receptor of OPGL is mainly restricted to the osteoclasts. Hsu et al. (1999) Proc. Natl. Acad. Sci. USA 96: 3540-5.
[0005] A number of research groups have recently identified TNF family ligands with the same or substantially similar sequence. The ligand has been variously named neutrokine α (WO 98/18921, published May 7, 1998), 63954 (WO 98/27114, published Jun. 25, 1998), TL5 (EP 869 180, published Oct. 7, 1998), NTN-2 (WO 98/55620 and WO 98/55621, published Dec. 10, 1998), TNRL1-alpha (WO 9911791, published Mar. 11, 1999), kay ligand (WO99/12964, published Mar. 18, 1999), and AGP-3 (U.S. Prov. App. Nos. 60/119,906, filed Feb. 12, 1999 and 60/166,271, filed Nov. 18, 1999, respectively); and TALL-1 (WO 00/68378, published Nov. 16, 2000). Each of these references is hereby incorporated by reference. Hereinafter, the ligands reported therein are collectively referred to as TALL-1.
[0006] TALL-1 is a member of the TNF ligand superfamily that is functionally involved in B cell survival and proliferation. Transgenic mice overexpressing TALL-1 had severe B cell hyperplasia and lupus-like autoimmune disease. Khare et al. (2000) PNAS 97(7):3370-3375). Both TACI and BCMA serve as cell surface receptors for TALL-1. Gross et al. (2000), Nature 404: 995-999; Ware (2000), J. Exp. Med. 192(11): F35-F37; Ware (2000), Nature 404: 949-950; Xia et al. (2000), J. Exp. Med. 192(1):137-143; Yu et al. (2000), Nature Immunology 1(3):252-256; Marsters et al. (2000), Current Biology 10:785-788; Hatzoglou et al. (2000) J. of Immunology 165:1322-1330; Shu et al. (2000) PNAS 97(16):9156-9161; Thompson et al. (2000) J. Exp. Med. 192(1):129-135; Mukhopadhyay et al. (1999) J. Biol. Chem. 274(23): 15978-81; Shu et al. (1999) J. Leukocyte Biol. 65:680-683; Gruss et al. (1995) Blood 85(12): 3378-3404; Smith et al. (1994), Cell 76: 959-962; U.S. Pat. No. 5,969,102, issued Oct. 19, 1999; WO 00/67034, published Nov. 9, 2000; WO 00/40716, published Jul. 13, 2000; WO 99/35170, published Jul. 15, 1999. Both receptors are expressed on B cells and signal through interaction with TRAF proteins. In addition, both TACI and BCMA also bind to another TNF ligand family member, APRIL. Yu et al. (2000), Nature Immunology 1(3):252-256. APRIL has also been demonstrated to induce B cell proliferation.
[0007] To date, no recombinant or modified proteins employing peptide modulators of TALL-1 have been disclosed. Recombinant and modified proteins are an emerging class of therapeutic agents. Useful modifications of protein therapeutic agents include combination with the “Fc” domain of an antibody and linkage to polymers such as polyethylene glycol (PEG) and dextran. Such modifications are discussed in detail in a patent application entitled, “Modified Peptides as Therapeutic Agents,” publicshed WO 00/24782, which is hereby incorporated by reference in its entirety.
[0008] A much different approach to development of therapeutic agents is peptide library screening. The interaction of a protein ligand with its receptor often takes place at a relatively large interface. However, as demonstrated for human growth hormone and its receptor, only a few key residues at the interface contribute to most of the binding energy. Clackson et al. (1995), Science 267: 383-6. The bulk of the protein ligand merely displays the binding epitopes in the right topology or serves functions unrelated to binding. Thus, molecules of only “peptide” length (2 to 40 amino acids) can bind to the receptor protein of a given large protein ligand. Such peptides may mimic the bioactivity of the large protein ligand (“peptide agonists”) or, through competitive binding, inhibit the bioactivity of the large protein ligand (“peptide antagonists”).
[0009] Phage display peptide libraries have emerged as a powerful method in identifying such peptide agonists and antagonists. See, for example, Scott et al. (1990), Science 249: 386; Devlin et al. (1990), Science 249: 404; U.S. Pat. No. 5,223,409, issued Jun. 29, 1993; U.S. Pat. No. 5,733,731, issued Mar. 31, 1998; U.S. Pat. No. 5,498,530, issued Mar. 12, 1996; U.S. Pat. No. 5,432,018, issued Jul. 11, 1995; U.S. Pat. No. 5,338,665, issued Aug. 16, 1994; U.S. Pat. No. 5,922,545, issued Jul. 13, 1999; WO 96/40987, published Dec. 19, 1996; and WO 98/15833, published Apr. 16, 1998 (each of which is incorporated by reference in its entirety). In such libraries, random peptide sequences are displayed by fusion with coat proteins of filamentous phage. Typically, the displayed peptides are affinity-eluted against an immobilized target protein. The retained phages may be enriched by successive rounds of affinity purification and repropagation. The best binding peptides may be sequenced to identify key residues within one or more structurally related families of peptides. See, e.g., Cwirla et al. (1997), Science 276: 1696-9, in which two distinct families were identified. The peptide sequences may also suggest which residues may be safely replaced by alanine scanning or by mutagenesis at the DNA level. Mutagenesis libraries may be created and screened to further optimize the sequence of the best binders. Lowman (1997), Ann. Rev. Biophys. Biomol. Struct. 26: 401-24.
[0010] Structural analysis of protein-protein interaction may also be used to suggest peptides that mimic the binding activity of large protein ligands. In such an analysis, the crystal structure may suggest the identity and relative orientation of critical residues of the large protein ligand, from which a peptide may be designed. See, e.g., Takasaki et al. (1997), Nature Biotech. 15: 1266-70. These analytical methods may also be used to investigate the interaction between a receptor protein and peptides selected by phage display, which may suggest further modification of the peptides to increase binding affinity.
[0011] Other methods compete with phage display in peptide research. A peptide library can be fused to the carboxyl terminus of the lac repressor and expressed in E. coli . Another E. coli -based method allows display on the cell's outer membrane by fusion with a peptidoglycan-associated lipoprotein (PAL). Hereinafter, these and related methods are collectively referred to as “ E. coli display.” In another method, translation of random RNA is halted prior to ribosome release, resulting in a library of polypeptides with their associated RNA still attached. Hereinafter, this and related methods are collectively referred to as “ribosome display.” Other methods employ peptides linked to RNA; for example, PROfusion technology, Phylos, Inc. See, for example, Roberts & Szostak (1997), Proc. Natl. Acad. Sci. USA, 94: 12297-303. Hereinafter, this and related methods are collectively referred to as “RNA-peptide screening.” Chemically derived peptide libraries have been developed in which peptides are immobilized on stable, non-biological materials, such as polyethylene rods or solvent-permeable resins. Another chemically derived peptide library uses photolithography to scan peptides immobilized on glass slides. Hereinafter, these and related methods are collectively referred to as “chemical-peptide screening.” Chemical-peptide screening may be advantageous in that it allows use of D-amino acids and other unnatural analogues, as well as non-peptide elements. Both biological and chemical methods are reviewed in Wells & Lowman (1992), Curr. Opin. Biotechnol. 3: 355-62. Conceptually, one may discover peptide mimetics of any protein using phage display, RNA-peptide screening, and the other methods mentioned above.
SUMMARY OF THE INVENTION
[0012] The present invention concerns therapeutic agents that modulate the activity of TALL-1. In accordance with the present invention, modulators of TALL-1 may comprise an amino acid sequence Dz 2 Lz 4 (SEQ ID NO: 108) wherein z 2 is an amino acid residue and z 4 is threonyl or isoleucyl. Such modulators of TALL-1 comprise molecules of the following formulae:
I(a) a 1 a 2 a 3 CDa 6 La 8 a 9 a 10 Ca 12 a 13 a 14 (SEQ. ID. NO:100)
wherein:
a 1 , a 2 , a 3 are each independently absent or amino acid residues; a 6 is an amino acid residue; a 9 is a basic or hydrophobic residue; a 8 is threonyl or isoleucyl; a 12 is a neutral hydrophobic residue; and
[0018] a 13 and a 14 are each independently absent or amino acid residues.
(SEQ. ID. NO:104) I(b) b 1 b 2 b 3 Cb 5 b 6 Db 8 Lb 10 b 11 b 12 b 13 b 14 Cb 16 b 17 b 18
wherein:
b 1 and b 2 are each independently absent or amino acid residues; b 3 is an acidic or amide residue; b 5 is an amino acid residue; b 6 is an aromatic residue; b 8 is an amino acid residue; b 10 is T or I; b 11 is a basic residue; b 12 and b 13 are each independently amino acid residues; b 14 is a neutral hydrophobic residue; and
[0028] b 16 , b 17 , and b 18 are each independently absent or amino acid residues.
(SEQ. ID. NO:105) I(c) c 1 c 2 c 3 Cc 5 Dc 7 Lc 9 c 10 c 11 c 12 c 13 c 14 Cc 16 c 17 c 18
wherein:
c 1 , c 2 , and c 3 are each independently absent or amino acid residues; c 5 is an amino acid residue; c 7 is an amino acid residue; c 9 is T or I; c 10 is a basic residue; c 11 and c 12 are each independently amino acid residues; c 13 is a neutral hydrophobic residue; c 14 is an amino acid residue; c 16 is an amino acid residue; c 17 is a neutral hydrophobic residue; and
[0039] c 18 is an amino acid residue or is absent.
(SEQ. ID. NO:106) I(d) d 1 d 2 d 3 Cd 5 d 6 d 7 WDd 10 Ld 12 d 13 d 14 Cd 15 d 16 d 17
wherein:
d 1 , d 2 , and d 3 are each independently absent or amino acid residues; d 5 , d 6 , and d 7 are each independently amino acid residues; d 10 is an amino acid residue; d 13 is T or I; d 14 is an amino acid residue; and
[0045] d 16 , d 17 and d 18 are each independently absent or amino acid residues.
(SEQ. ID. NO:107) (I)e e 1 e 2 e 3 Ce 5 e 6 e 7 De 9 Le 11 Ke 13 Ce 15 e 16 e 17 e 18
wherein:
e 1 , e 2 , and e 3 are each independently absent or amino acid residues; e 5 , e 6 , e 7 , e 9 , and e 13 are each independently amino acid residues; e 11 is T or I; and
[0049] e 15 , e 16 , and e 17 are each independently absent or amino acid residues.
I(f) f 1 f 2 f 3 Kf 5 Df 7 Lf 9 f 10 Qf 12 f 13 f 14 (SEQ. ID NO:109)
wherein:
f 1 , f 2 , and f 3 are absent or are amino acid residues (with one of f 1 , f 2 , and f 3 preferred to be C when one of f 12 , f 13 , and f 14 is C); f 5 is W, Y, or F (W preferred); f 7 is an amino acid residue (L preferred); f 9 is T or I (T preferred);
[0054] f 10 is K, R, or H (K preferred);
f 12 is C, a neutral hydrophobic residue, or a basic residue (W, C, or R preferred); f 13 is C, a neutral hydrophobic residue or is absent (V preferred); and f 14 is any amino acid residue or is absent; provided that only one of f 1 , f 2 , and f 3 may be C, and only one of f 12 , f 13 , and f 14 may be C.
[0059] Compounds of formulae I(a) through I(f) above incorporate Dz 2 Lz 4 , as well as SEQ ID NO: 63 hereinafter. The sequence of I(f) was derived as a consensus sequence as described in Example 1 hereinbelow. Of compounds within formula I(f), those within the formula
I(f′) f 1 f 2 f 3 KWDf 7 Lf 9 KQf 12 f 13 f 14 (SEQ ID NO:125)
are preferred. Compounds falling within formula I(f′) include SEQ ID NOS: 32, 58, 60, 62, 63, 66, 67, 69, 70, 114, 115, 122, 123, 124, 147-150, 152-177, 179, 180, 187.
[0060] Also in accordance with the present invention are compounds having the consensus motif:
PFPWE (SEQ ID NO:110)
which also bind TALL-1.
[0061] Further in accordance with the present invention are compounds of the formulae:
I(g) g 1 g 2 g 3 Cg 5 PFg 8 Wg 10 Cg 11 g 12 g 13 (SEQ. ID. NO. 101)
[0062] wherein:
g 1 , g 2 and g 3 are each independently absent or amino acid residues; g 5 is a neutral hydrophobic residue; g 8 is a neutral hydrophobic residue;
[0066] g 10 is an acidic residue;
I(h) h 1 h 2 h 3 CWh 6 h 7 WGh 10 Ch 12 h 13 h 14 (SEQ. ID. NO:102)
[0067] wherein:
h 1 , h 2 , and h 3 are each independently absent or amino acid residues; h 6 is a hydrophobic residue; h 7 is a hydrophobic residue; h 10 is an acidic or polar hydrophobic residue; and
[0072] h 12 , h 13 , and h 14 are each independently absent or amino acid residues.
(SEQ. ID. NO: 103) I(i) i 1 i 2 i 3 Ci 5 i 6 i 7 i 8 i 9 i 10 Ci 12 i 13 i 14
wherein:
i 1 is absent or is an amino acid residue; i 2 is a neutral hydrophobic residue; i 3 is an amino acid residue; i 5 , i 6 , i 7 , and i 8 are each independently amino acid residues; i 9 is an acidic residue; i 10 is an amino acid residue; i 12 and i 13 are each independently amino acid residues; and i 14 is a neutral hydrophobic residue.
[0081] The compounds defined by formulae I(g) through I(i) also bind TALL-1.
[0082] Further in accordance with present invention, modulators of TALL-1 comprise:
a) a TALL-1 modulating domain (e.g., an amino acid sequence of Formulae I(a) through I(i)), preferably the amino acid sequence Dz 2 Lz 4 , or sequences derived therefrom by phage display, RNA-peptide screening, or the other techniques mentioned above; and b) a vehicle, such as a polymer (e.g., PEG or dextran) or an Fc domain, which is preferred;
wherein the vehicle is covalently attached to the TALL-1 modulating domain. The vehicle and the TALL-1 modulating domain may be linked through the N- or C-terminus of the TALL-1 modulating domain, as described further below. The preferred vehicle is an Fc domain, and the preferred Fc domain is an IgG Fc domain. Such Fc-linked peptides are referred to herein as “peptibodies.” Preferred TALL-1 modulating domains comprise the amino acid sequences described hereinafter in Tables 1 and 2. Other TALL-1 modulating domains can be generated by phage display, RNA-peptide screening and the other techniques mentioned herein.
[0085] Further in accordance with the present invention is a process for making TALL-1 modulators, which comprises:
[0086] a. selecting at least one peptide that binds to TALL-1; and
[0087] b. covalently linking said peptide to a vehicle.
[0000] The preferred vehicle is an Fc domain. Step (a) is preferably carried out by selection from the peptide sequences in Table 2 hereinafter or from phage display, RNA-peptide screening, or the other techniques mentioned herein.
[0088] The compounds of this invention may be prepared by standard synthetic methods, recombinant DNA techniques, or any other methods of preparing peptides and fusion proteins. Compounds of this invention that encompass non-peptide portions may be synthesized by standard organic chemistry reactions, in addition to standard peptide chemistry reactions when applicable.
[0089] The primary use contemplated for the compounds of this invention is as therapeutic or prophylactic agents. The vehicle-linked peptide may have activity comparable to—or even greater than—the natural ligand mimicked by the peptide.
[0090] The compounds of this invention may be used for therapeutic or prophylactic purposes by formulating them with appropriate pharmaceutical carrier materials and administering an effective amount to a patient, such as a human (or other mammal) in need thereof. Other related aspects are also included in the instant invention.
[0091] Numerous additional aspects and advantages of the present invention will become apparent upon consideration of the figures and detailed description of the invention.
BRIEF DESCRIPTION OF THE FIGURES
[0092] FIG. 1 shows exemplary Fc dimers that may be derived from an IgG1 antibody. “Fc” in the figure represents any of the Fc variants within the meaning of “Fc domain” herein. “X 1 ” and “X 2 ” represent peptides or linker-peptide combinations as defined hereinafter. The specific dimers are as follows:
[0093] A, D: Single disulfide-bonded dimers. IgG1 antibodies typically have two disulfide bonds at the hinge region of the antibody. The Fc domain in FIGS. 1A and 1D may be formed by truncation between the two disulfide bond sites or by substitution of a cysteinyl residue with an unreactive residue (e.g., alanyl). In FIG. 1A , the Fc domain is linked at the amino terminus of the peptides; in 1 D, at the carboxyl terminus.
[0094] B, E: Doubly disulfide-bonded dimers. This Fc domain may be formed by truncation of the parent antibody to retain both cysteinyl residues in the Fc domain chains or by expression from a construct including a sequence encoding such an Fc domain. In FIG. 1B , the Fc domain is linked at the amino terminus of the peptides; in 1 E, at the carboxyl terminus.
[0095] C, F: Noncovalent dimers. This Fc domain may be formed by elimination of the cysteinyl residues by either truncation or substitution. One may desire to eliminate the cysteinyl residues to avoid impurities formed by reaction of the cysteinyl residue with cysteinyl residues of other proteins present in the host cell. The noncovalent bonding of the Fc domains is sufficient to hold together the dimer.
[0096] Other dimers may be formed by using Fc domains derived from different types of antibodies (e.g., IgG2, IgM).
[0097] FIG. 2 shows the structure of preferred compounds of the invention that feature tandem repeats of the pharmacologically active peptide. FIG. 2A shows a single chain molecule and may also represent the DNA construct for the molecule. FIG. 2B shows a dimer in which the linker-peptide portion is present on only one chain of the dimer. FIG. 2C shows a dimer having the peptide portion on both chains. The dimer of FIG. 2C will form spontaneously in certain host cells upon expression of a DNA construct encoding the single chain shown in FIG. 3A . In other host cells, the cells could be placed in conditions favoring formation of dimers or the dimers can be formed in vitro.
[0098] FIG. 3 shows exemplary nucleic acid and amino acid sequences (SEQ ID NOS: 1 and 2, respectively) of human IgG1 Fc that may be used in this invention.
[0099] FIGS. 4A through 4F show the nucleotide and amino acid sequences (SEQ ID NOS: 3-27) S of NdeI to SalI fragments encoding peptide and linker.
[0100] FIGS. 5A through 5M show the nucleotide sequence (SEQ ID NO: 28) of pAMG21-RANK-Fc vector, which was used to construct Fc-linked molecules of the present invention. These figures identify a number of features of the nucleic acid, including:
promoter regions PcopB, PrepA, RNAI, APHII, luxPR, and luxPL; mRNA for APHII, luxR; coding sequences and amino acid sequences for the proteins copB protein, copT, repAI, repA4, APHII, luxR, RANK, and Fc; binding sites for the proteins copB, CRP; hairpins T1, T2, T7, and toop; operator site for lux protein; enzyme restriction sites for Pfll108I, BglII, ScaI, BmnI, DrdII, DraIII, BstBI, AceIII, AflII, PFlMI, BglI, SfiI, BstEII, BspLullI, NspV, BplI, EagI, BcI, NsiI, BsaI, Pspl406I, AatII, BsmI, NruI, NdeI, ApaLI, Acc65I, KpnI, SalI, AccI, BspEI, AhdI, BspHI, EconI, BsrGI, BmaI, SmaI, SexAI, BamHI, and BlpI.
[0108] FIGS. 6A and 6B show the DNA sequence (SEQ ID NO: 97) inserted into pCFM1656 between the unique AatII (position #4364 in pCFM1656) and SacII (position #4585 in pCFM1656) restriction sites to form expression plasmid pAMG21 (ATCC accession no. 98113).
[0109] FIG. 7 shows that the TALL-1 peptibody (SEQ ID NO: 70) inhibits TALL-1-mediated B cell proliferation. Purified B cells (10 5 ) from B6 mice were cultured in triplicates in 96-well plated with the indicated amounts of TALL-1 consensus peptibody in the presence of 10 ng/ml TALL-1 plus 2 μg/ml anti-IgM antibody. Proliferation was measured by radioactive [ 3 H]thymidine uptake in the last 18 h of pulse. Data shown represent mean±SD triplicate wells.
[0110] FIG. 8 shows that a TALL-1 N-terminal tandem dimer peptibodies (SEQ ID NO: 123, 124 in Table 5B hereinafter) are preferable for inhibition of TALL-1-mediated B cell proliferation. Purified B cells (10 5 ) from B6 mice were cultured in triplicates in 96-well plated with the indicated amounts of TALL-1 12-3 peptibody and TALL-1 consensus peptibody (SEQ ID NOS: 115 and 122 of Table 5B) or the related dimer peptibodies (SEQ ID NOS: 123, 124) in the presence of 10 ng/ml TALL-1 plus 2 μg/ml anti-IgM antibody. Proliferation was measured by radioactive [ 3 H]thymidine uptake in the last 18 h of pulse. Data shown represent mean±SD triplicate wells.
[0111] FIG. 9 . AGP3 peptibody binds to AGP3 with high affinity. Dissociation equilibrium constant (K D ) was obtained from nonlinear regression of the competition curves using a dual-curve one-site homogeneous binding model (KinEx™ software). K D is about 4 pM for AGP3 peptibody binding with human AGP3 (SEQ ID NO: 123).
[0112] FIGS. 10A and 10B . AGP3 peptibody blocks both human and murine AGP3 in the Biacore competition assay. Soluble human TACI protein was immobilized to B1 chip. 1 nM of recombinant human AGP3 protein (upper panel) or 5 nM of recombinant murine AGP3 protein (lower panel) was incubated with indicated amount of AGP3 peptibody before injected over the surface of receptor. Relative human AGP3 and murine AGP3 (binding response was shown (SEQ ID NO: 123).
[0113] FIGS. 11A and 11B . AGP3 peptibody blocked AGP3 binding to all three receptors TACI, BCMA and BAFFR in Biacore competition assay. Recombinant soluble receptor TACI, BCMA and BAFFR proteins were immobilized to CM5 chip. 1 nM of recombinant human AGP3 (upper panel) were incubated with indicated amount of AGP3 peptibody before injected over each receptor surface. Relative binding of AGP3 was measured. Similarly, 1 nM of recombinant APRIL protein was incubated with indicated amount of AGP3 peptibody before injected over each receptor surface. AGP3 peptibody didn't inhibit APRIL binding to all three receptors (SEQ ID NO: 123).
[0114] FIGS. 12A and 12B . AGP3 peptibody inhibits mouse serum immunoglobulin level increase induced by human AGP3 challenge. Balb/c mice received 7 daily intraperitoneal injections of 1 mg/Kg human AGP3 protein along with saline, human Fc, or AGP3 peptibody at indicated doses, and were bled on day 8. Serum total IgM and IgA level were measured by ELISA (SEQ ID NO: 123).
[0115] FIG. 13 . AGP3 peptibody treatment reduced arthritis severity in the mouse CIA model. Eight to 12 weeks old DBA/1 male mice were immunized with bovine collagen type II (bCII) emulsified in complete freunds adjuvant intradermally at the base of tail, and were boosted 3 weeks after the initial immunization with bCII emulsified in incomplete freunds adjuvant. Treatment with indicated dosage of AGP3 peptibody was begun from the day of booster immunization for 4 weeks. As described before (Khare et al., J. Immunol. 155: 3653-9, 1995), all four paws were individually scored from 0-3 for arthritis severity (SEQ ID NO: 123).
[0116] FIG. 14 . AGP3 peptibody treatment inhibited anti-collagen antibody generation in the mouse CIA model. Serum samples were taken one week after final treatment (day 35) as described above. Serum anti-collagen II antibody level was determined by ELISA analysis (SEQ ID NO: 123).
[0117] FIGS. 15A and 15B . AGP3 peptibody treatment delayed proteinuria onset and improved survival in NZB/NZW lupus mice. Five-month-old lupus prone NZBx NZBWF1 mice were treated i.p. 3×/week for 8 weeks with PBS or indicated doses of AGP3 peptibody (SEQ ID NO: 123) or human Fc proteins. Protein in the urine was evaluated monthly throughout the life of the experiment with Albustix reagent strips (Bayer AG).
[0118] FIGS. 16A and 16B show the nucleic acid and amino acid sequences of a preferred TALL-1-binding peptibody (SEQ ID NOS: 189 and 123)
DETAILED DESCRIPTION OF THE INVENTION
[0119] Definition of Terms
[0120] The terms used throughout this specification are defined as follows, unless otherwise limited in specific instances.
[0121] General Definitions
[0122] The term “comprising” means that a compound may include additional amino acids on either or both of the N- or C-termini of the given sequence. Of course, these additional amino acids should not significantly interfere with the activity of the compound.
[0123] Additionally, physiologically acceptable salts of the compounds of this invention are also encompassed herein. The term “physiologically acceptable salts” refers to any salts that are known or later discovered to be pharmaceutically acceptable. Some specific examples are: acetate; trifluoroacetate; hydrohalides, such as hydrochloride and hydrobromide; sulfate; citrate; tartrate; glycolate; and oxalate.
[0124] Amino Acids
[0125] The term “acidic residue” refers to amino acid residues in D- or L-form having sidechains comprising acidic groups. Exemplary acidic residues include D and E.
[0126] The term “amide residue” refers to amino acids in D- or L-form having sidechains comprising amide derivatives of acidic groups. Exemplary residues include N and Q.
[0127] The term “aromatic residue” refers to amino acid residues in D- or L-form having sidechains comprising aromatic groups. Exemplary aromatic residues include F, Y, and W.
[0128] The term “basic residue” refers to amino acid residues in D- or L-form having sidechains comprising basic groups. Exemplary basic residues include H, K, and R.
[0129] The term “hydrophilic residue” refers to amino acid residues in D- or L-form having sidechains comprising polar groups. Exemplary hydrophilic residues include C, S, T, N, and Q.
[0130] The term “nonfunctional residue” refers to amino acid residues in D- or L-form having sidechains that lack acidic, basic, or aromatic groups. Exemplary nonfunctional amino acid residues include M, G, A, V, I, L and norleucine (Nle).
[0131] The term “neutral hydrophobic residue” refers to amino acid residues in D- or L-form having sidechains that lack basic, acidic, or polar groups. Exemplary neutral hydrophobic amino acid residues include A, V, L, I, P, W, M, and F.
[0132] The term “polar hydrophobic residue” refers to amino acid residues in D- or L-form having sidechains comprising polar groups. Exemplary polar hydrophobic amino acid residues include T, G, S, Y, C, Q, and N.
[0133] The term “hydrophobic residue” refers to amino acid residues in D- or L-form having sidechains that lack basic or acidic groups. Exemplary hydrophobic amino acid residues include A, V, L, I, P, W, M, F, T, G, S, Y, C, Q, and N.
[0134] Peptides
[0135] The term “peptide” refers to molecules of 1 to 40 amino acids, with molecules of 5 to 20 amino acids preferred. Exemplary peptides may comprise the TALL-1 modulating domain of a naturally occurring molecule or comprise randomized sequences.
[0136] The term “randomized” as used to refer to peptide sequences refers to fully random sequences (e.g., selected by phage display methods or RNA-peptide screening) and sequences in which one or more residues of a naturally occurring molecule is replaced by an amino acid residue not appearing in that position in the naturally occurring molecule. Exemplary methods for identifying peptide sequences include phage display, E. coli display, ribosome display, RNA-peptide screening, chemical screening, and the like.
[0137] The term “TALL-1 modulating domain” refers to any amino acid sequence that binds to the TALL-1 and comprises naturally occurring sequences or randomized sequences. Exemplary TALL-1 modulating domains can be identified or derived by phage display or other methods mentioned herein.
[0138] The term “TALL-1 antagonist” refers to a molecule that binds to the TALL-1 and increases or decreases one or more assay parameters opposite from the effect on those parameters by full length native TALL-1. Such activity can be determined, for example, by such assays as described in the subsection entitled “Biological activity of AGP-3” in the Materials & Methods section of the patent application entitled, “TNF-RELATED PROTEINS”, WO 00/47740, published Aug. 17, 2000.
[0139] Vehicles and Peptibodies
[0140] The term “vehicle” refers to a molecule that prevents degradation and/or increases half-life, reduces toxicity, reduces immunogenicity, or increases biological activity of a therapeutic protein. Exemplary vehicles include an Fc domain (which is preferred) as well as a linear polymer (e.g., polyethylene glycol (PEG), polylysine, dextran, etc.); a branched-chain polymer (see, for example, U.S. Pat. No. 4,289,872 to Denkenwalter et al., issued Sep. 15, 1981; U.S. Pat. No. 5,229,490 to Tam, issued Jul. 20, 1993; WO 93/21259 by Frechet et al., published 28 Oct. 1993); a lipid; a cholesterol group (such as a steroid); a carbohydrate or oligosaccharide (e.g., dextran); any natural or synthetic protein, polypeptide or peptide that binds to a salvage receptor; albumin, including human serum albumin (HSA), leucine zipper domain, and other such proteins and protein fragments. Vehicles are further described hereinafter.
[0141] The term “native Fc” refers to molecule or sequence comprising the sequence of a non-antigen-binding fragment resulting from digestion of whole antibody, whether in monomeric or multimeric form. The original immunoglobulin source of the native Fc is preferably of human origin and may be any of the immunoglobulins, although IgG1 and IgG2 are preferred. Native Fc's are made up of monomeric polypeptides that may be linked into dimeric or multimeric forms by covalent (i.e., disulfide bonds) and non-covalent association. The number of intermolecular disulfide bonds between monomeric subunits of native Fc molecules ranges from 1 to 4 depending on class (e.g., IgG, IgA, IgE) or subclass (e.g., IgG1, IgG2, IgG3, IgA1, IgGA2). One example of a native Fc is a disulfide-bonded dimer resulting from papain digestion of an IgG (see Ellison et al. (1982), Nucleic Acids Res. 10: 4071-9). The term “native Fc” as used herein is generic to the monomeric, dimeric, and multimeric forms.
[0142] The term “Fc variant” refers to a molecule or sequence that is modified from a native Fc but still comprises a binding site for the salvage receptor, FcRn. International applications WO 97/34631 (published 25 Sep. 1997) and WO 96/32478 describe exemplary Fc variants, as well as interaction with the salvage receptor, and are hereby incorporated by reference in their entirety. Thus, the term “Fc variant” comprises a molecule or sequence that is humanized from a non-human native Fc. Furthermore, a native Fc comprises sites that may be removed because they provide structural features or biological activity that are not required for the fusion molecules of the present invention. Thus, the term “Fc variant” comprises a molecule or sequence that lacks one or more native Fc sites or residues that affect or are involved in (1) disulfide bond formation, (2) incompatibility with a selected host cell (3) N-terminal heterogeneity upon expression in a selected host cell, (4) glycosylation, (5) interaction with complement, (6) binding to an Fc receptor other than a salvage receptor, or (7) antibody-dependent cellular cytotoxicity (ADCC). Fc variants are described in further detail hereinafter.
[0143] The term “Fc domain” encompasses native Fc and Fc variant molecules and sequences as defined above. As with Fc variants and native Fc's, the term “Fc domain” includes molecules in monomeric or multimeric form, whether digested from whole antibody or produced by other means.
[0144] The term “multimer” as applied to Fc domains or molecules comprising Fc domains refers to molecules having two or more polypeptide chains associated covalently, noncovalently, or by both covalent and non-covalent interactions. IgG molecules typically form dimers; IgM, pentamers; IgD, dimers; and IgA, monomers, dimers, trimers, or tetramers. Multimers may be formed by exploiting the sequence and resulting activity of the native Ig source of the Fc or by derivatizing (as defined below) such a native Fc.
[0145] The term “dimer” as applied to Fc domains or molecules comprising Fc domains refers to molecules having two polypeptide chains associated covalently or non-covalently. Thus, exemplary dimers within the scope of this invention are as shown in FIG. 1 .
[0146] The terms “derivatizing” and “derivative” or “derivatized” comprise processes and resulting compounds respectively in which (1) the compound has a cyclic portion; for example, cross-linking between cysteinyl residues within the compound; (2) the compound is cross-linked or has a cross-linking site; for example, the compound has a cysteinyl residue and thus forms cross-linked dimers in culture or in vivo; (3) one or more peptidyl linkage is replaced by a non-peptidyl linkage; (4) the N-terminus is replaced by —NRR 1 , NRC(O)R 1 , —NRC(O)OR 1 , —NRS(O) 2 R 1 , —NHC(O)NHR, a succinimide group, or substituted or unsubstituted benzyloxycarbonyl-NH—, wherein R and R 1 and the ring substituents are as defined hereinafter; (5) the C-terminus is replaced by —C(O)R 2 or —NR 3 R 4 wherein R 2 , R 3 and R 4 are as defined hereinafter; and (6) compounds in which individual amino acid moieties are modified through treatment with agents capable of reacting with selected side chains or terminal residues. Derivatives are further described hereinafter.
[0147] The terms “peptibody” and “peptibodies” refer to molecules comprising an Fc domain and at least one peptide. Such peptibodies may be multimers or dimers or fragments thereof, and they may be derivatized. In the present invention, the molecules of formulae II through VI hereinafter are peptibodies when V 1 is an Fc domain.
[0148] Structure of Compounds
[0149] In General. The present inventors identified sequences capable of binding to and modulating the biological activity of TALL-1. These sequences can be modified through the techniques mentioned above by which one or more amino acids may be changed while maintaining or even improving the binding affinity of the peptide.
[0150] In the compositions of matter prepared in accordance with this invention, the peptide(s) may be attached to the vehicle through the peptide's N-terminus or C-terminus. Any of these peptides may be linked in tandem (i.e., sequentially), with or without linkers. Thus, the vehicle-peptide molecules of this invention may be described by the following formula:
(X 1 ) a -V 1 -(X 2 ) b II
wherein:
[0151] V 1 is a vehicle (preferably an Fc domain);
[0152] X 1 and X 2 are each independently selected from -(L 1 ) c -P 1 , -(L 1 ) c -P 1 -(L 2 ) d -P 2 , -(L 1 ) c -P 1 -(L 2 ) d -P 2 -(L 3 ) e -P 3 , and -(L 1 ) c -P 1 -(L 2 ) d -P 2 -(L 3 ) e -P 3 -(L 4 ) f -P 4
[0153] P 1 , P 2 , P 3 , and P 4 are each independently sequences of TALL-1 modulating domains, such as those of Formulae I(a) through I(i);
[0154] L 1 , L 2 , L 3 , and L 4 are each independently linkers; and
[0155] a, b, c, d, e, and f are each independently 0 or 1, provided that at least one of a and b is 1.
[0156] Thus, compound II comprises preferred compounds of the formulae
X 1 -V 1 III
and multimers thereof wherein V 1 is an Fc domain and is attached at the C-terminus of A 1 ;
V 1 -X 2 IV
and multimers thereof wherein V 1 is an Fc domain and is attached at the N-terminus of A 2 ;
V 1 -(L 1 ) c -P 1 V
and multimers thereof wherein V 1 is an Fc domain and is attached at the N-terminus of -(L 1 ) c -P 1 ; and
V 1 -(L 1 ) c -P 1 -(L 2 ) d -P 2 VI
and multimers thereof wherein V 1 is an Fc domain and is attached at the N-terminus of -L 1 -P 1 -L 2 -P 2 .
[0157] Peptides. The peptides of this invention are useful as TALL-1 modulating peptides or as TALL-1 modulating domains in the molecules of formulae II through VI. Molecules of this invention comprising these peptide sequences may be prepared by methods known in the art.
[0158] Preferred peptide sequences are those of the foregoing formulae I(a) having the substituents identified below.
TABLE 1 Preferred peptide substituents Formula I(a) a 8 is T; a 9 is a basic residue (K most preferred); and a 12 is a neutral hydrophobic residue (F most preferred). Formula I(b) b 3 is D, Q, or E; b 6 is W or Y; b 10 is T; b 11 is K or R; and b 14 is V or L. Formula I(c) c 9 is T; c 10 is K or R; c 13 is a I, L, or V; and c 17 is A or L. Formula I(d) d 13 is T. Formula I(e) e 11 is T. Formula I(f) f 6 is T; f 7 is K; and f 10 is V. Formula I(g) g 5 is W; g 8 is P; g 10 is E; and g 13 is a basic residue. Formula I(h) h 1 is G; h 6 is A; h 7 is a neutral hydrophobic residue; and h 10 is an acidic residue. Formula I(i) i 2 is W; and i 14 is W.
[0159] Preferred peptide sequences appear in Table 2 below.
TABLE 2 Preferred TALL-1 modulating domains Sequence SEQ ID NO: PGTCFPFPWECTHA 29 WGACWPFPWECFKE 30 VPFCDLLTKHCFEA 31 GSRCKYKWDVLTKQCFHH 32 LPGCKWDLLIKQWVCDPL 33 SADCYFDILTKSDVCTSS 34 SDDCMYDQLTRMFICSNL 35 DLNCKYDELTYKEWCQFN 36 FHDCKYDLLTRQMVCHGL 37 RNHCFWDHLLKQDICPSP 38 ANQCWWDSLTKKNVCEFF 39 YKGRQMWDILTRSWVVSL 126 QDVGLWWDILTRAWMPNI 127 QNAQRVWDLLIRTWVYPQ 128 GWNEAWWDELTKIWVLEQ 129 RITCDTWDSLIKKCVPQS 130 GAIMQFWDSLTKTWLRQS 131 WLHSGWWDPLTKHWLQKV 132 SEWFFWFDPLTRAQLKFR 133 GVWFWWFDPLTKQWTQAG 134 MQCKGYYDILTKWCVTNG 135 LWSKEVWDILTKSWVSQA 136 KAAGWWFDWLTKVWVPAP 137 AYQTWFWDSLTRLWLSTT 138 SGQHFWWDLLTRSWTPST 139 LGVGQKWDPLTKQWVSRG 140 VGKMCQWDPLIKRTVCVG 141 CRQGAKFDLLTKQCLLGR 142 GQAIRHWDVLTKQWVDSQ 143 RGPCGSWDLLTKHCLDSQ 144 WQWKQQWDLLTKQMVWVG 145 PITICRKDLLTKQVVCLD 146 KTCNGKWDLLTKQCLQQA 147 KCLKGKWDLLTKQCVTEV 148 RCWNGKWDLLTKQCIHPW 149 NRDMRKWDPLIKQWIVRP 150 QAAAATWDLLTKQWLVPP 151 PEGGPKWDPLTKQFLPPV 152 QTPQKKWDLLTKQWFTRN 153 IGSPCKWDLLTKQMICQT 154 CTAAGKWDLLTKQCIQEK 155 VSQCMKWDLLTKQCLQGW 156 VWGTWKWDLLTKQYLPPQ 157 GWWEMKWDLLTKQWYRPQ 158 TAQVSKWDLLTKQWLPLA 159 QLWGTKWDLLTKQYIQIM 160 WATSQKWDLLTKQWVQNM 161 QRQCAKWDLLTKQCVLFY 162 KTTDCKWDLLTKQRICQV 163 LLCQGKWDLLTKQCLKLR 164 LMWFWKWDLLTKQLVPTF 165 QTWAWKWDLLTKQWIGPM 166 NKELLKWDLLTKQCRGRS 167 GQKDLKWDLLTKQYVRQS 168 PKPCQKWDLLTKQCLGSV 169 GQIGWKWDLLTKQWIQTR 170 VWLDWKWDLLTKQWIHPQ 171 QEWEYKWDLLTKQWGWLR 172 HWDSWKWDLLTKQWVVQA 173 TRPLQKWDLLTKQWLRVG 174 SDQWQKWDLLTKQWFWDV 175 QQTFMKWDLLTKQWIRRH 176 QGECRKWDLLTKQCFPGQ 177 GQMGWRWDPLIKMCLGPS 178 QLDGCKWDLLTKQKVCIP 179 HGYWQKWDLLTKQWVSSE 180 HQGQCGWDLLTRIYLPCH 181 LHKACKWDLLTKQCWPMQ 182 GPPGSVWDLLTKIWIQTG 183 ITQDWRFDTLTRLWLPLR 184 QGGFAAWDVLTKMWTTVP 185 GHGTPWWDALTRIWILGV 186 VWPWQKWDLLTKQFVFQD 187 WQWSWKWDLLTRQYISSS 188 NQTLWKWDLLTKQFITYM 60 PVYQGWWDTLTKLYIWDG 61 WLDGGWRDPLIKRSVQLG 62 GHQQFKWDLLTKQWVQSN 63 QRVGQFWDVLTKMFITGS 64 QAQGWSYDALIKTWIRWP 65 GWMHWKWDPLTKQALPWM 66 GHPTYKWDLLTKQWILQM 67 WNNWSLWDPLTKLWLQQN 68 WQWGWKWDLLTKQWVQQQ 69 GQMGWRWDPLTKMWLGTS 70
[0160] It is noted that the known receptors for TALL-1 bear some sequence homology with preferred peptides:
12-3 LPGCK WDLL I K QWVCDP L BAFFR MRRGPRSLRGRDAPVPTPCVPTEC YDLL V R KCVDCR L L TACI TICNHQSQRTCAAFCRSLSCRKEQGKF YD H L L R DCISCASI BCMA FVSPSQEIRGRFRRMLQMAGQCSQNEY FD S L L H ACIPCQ L RC (SEQ ID NOS: 33, 195, 196, and 197, respectively).
[0161] Any peptide containing a cysteinyl residue may be cross-linked with another Cys-containing peptide, either or both of which may be linked to a vehicle. Any peptide having more than one Cys residue may form an intrapeptide disulfide bond, as well. Any of these peptides may be derivatized as described hereinafter.
[0162] Additional useful peptide sequences may result from conservative and/or non-conservative modifications of the amino acid sequences of the sequences in Table 2.
[0163] Conservative modifications will produce peptides having functional and chemical characteristics similar to those of the peptide from which such modifications are made. In contrast, substantial modifications in the functional and/or chemical characteristics of the peptides may be accomplished by selecting substitutions in the amino acid sequence that differ significantly in their effect on maintaining (a) the structure of the molecular backbone in the area of the substitution, for example, as a sheet or helical conformation, (b) the charge or hydrophobicity of the molecule at the target site, or (c) the size of the molecule.
[0164] For example, a “conservative amino acid substitution” may involve a substitution of a native amino acid residue with a normative residue such that there is little or no effect on the polarity or charge of the amino acid residue at that position. Furthermore, any native residue in the polypeptide may also be substituted with alanine, as has been previously described for “alanine scanning mutagenesis” (see for example, MacLennan et al., 1998 , Acta Physiol. Scand. Suppl. 643:55-67; Sasaki et al., 1998 , Adv. Biophys. 35:1-24, which discuss alanine scanning mutagenesis).
[0165] Desired amino acid substitutions (whether conservative or non-conservative) can be determined by those skilled in the art at the time such substitutions are desired. For example, amino acid substitutions can be used to identify important residues of the peptide sequence, or to increase or decrease the affinity of the peptide or vehicle-peptide molecules (see preceding formulae) described herein. Exemplary amino acid substitutions are set forth in Table 3.
TABLE 3 Amino Acid Substitutions Original Exemplary Preferred Residues Substitutions Substitutions Ala (A) Val, Leu, Ile Val Arg (R) Lys, Gln, Asn Lys Asn (N) Gln Gln Asp (D) Glu Glu Cys (C) Ser, Ala Ser Gln (Q) Asn Asn Glu (E) Asp Asp Gly (G) Pro, Ala Ala His (H) Asn, Gln, Lys, Arg Arg Ile (I) Leu, Val, Met, Ala, Leu Phe, Norleucine Leu (L) Norleucine, Ile, Val, Ile Met, Ala, Phe Lys (K) Arg, 1,4 Diamino- Arg butyric Acid, Gln, Asn Met (M) Leu, Phe, Ile Leu Phe (F) Leu, Val, Ile, Ala, Tyr Leu Pro (P) Ala Gly Ser (S) Thr, Ala, Cys Thr Thr (T) Ser Ser Trp (W) Tyr, Phe Tyr Tyr (Y) Trp, Phe, Thr, Ser Phe Val (V) Ile, Met, Leu, Phe, Leu Ala, Norleucine
[0166] In certain embodiments, conservative amino acid substitutions also encompass non-naturally occurring amino acid residues which are typically incorporated by chemical peptide synthesis rather than by synthesis in biological systems.
[0167] As noted in the foregoing section “Definition of Terms,” naturally occurring residues may be divided into classes based on common sidechain properties that may be useful for modifications of sequence. For example, non-conservative substitutions may involve the exchange of a member of one of these classes for a member from another class. Such substituted residues may be introduced into regions of the peptide that are homologous with non-human orthologs, or into the non-homologous regions of the molecule. In addition, one may also make modifications using P or G for the purpose of influencing chain orientation.
[0168] In making such modifications, the hydropathic index of amino acids may be considered. Each amino acid has been assigned a hydropathic index on the basis of their hydrophobicity and charge characteristics, these are: isoleucine (+4.5); valine (+4.2); leucine (+3.8); phenylalanine (+2.8); cysteine/cystine (+2.5); methionine (+1.9); alanine (+1.8); glycine (−0.4); threonine (−0.7); serine (−0.8); tryptophan (−0.9); tyrosine (−1.3); proline (−1.6); histidine (−3.2); glutamate (−3.5); glutamine (−3.5); aspartate (−3.5); asparagine (−3.5); lysine (−3.9); and arginine (−4.5).
[0169] The importance of the hydropathic amino acid index in conferring interactive biological function on a protein is understood in the art. Kyte et al., J. Mol. Biol., 157: 105-131 (1982). It is known that certain amino acids may be substituted for other amino acids having a similar hydropathic index or score and still retain a similar biological activity. In making changes based upon the hydropathic index, the substitution of amino acids whose hydropathic indices are within ±2 is preferred, those which are within ±1 are particularly preferred, and those within ±0.5 are even more particularly preferred.
[0170] It is also understood in the art that the substitution of like amino acids can be made effectively on the basis of hydrophilicity. The greatest local average hydrophilicity of a protein, as governed by the hydrophilicity of its adjacent amino acids, correlates with its immunogenicity and antigenicity, i.e., with a biological property of the protein.
[0171] The following hydrophilicity values have been assigned to amino acid residues: arginine (+3.0); lysine (+3.0); aspartate (+3.0±1); glutamate (+3.0±1); serine (+0.3); asparagine (+0.2); glutamine (+0.2); glycine (0); threonine (−0.4); proline (−0.5±1); alanine (−0.5); histidine (−0.5); cysteine (−1.0); methionine (−1.3); valine (−1.5); leucine (−1.8); isoleucine (−1.8); tyrosine (−2.3); phenylalanine (−2.5); tryptophan (−3.4). In making changes based upon similar hydrophilicity values, the substitution of amino acids whose hydrophilicity values are within ±2 is preferred, those which are within ±1 are particularly preferred, and those within ±0.5 are even more particularly preferred. One may also identify epitopes from primary amino acid sequences on the basis of hydrophilicity. These regions are also referred to as “epitopic core regions.”
[0172] A skilled artisan will be able to determine suitable variants of the polypeptide as set forth in the foregoing sequences using well known techniques. For identifying suitable areas of the molecule that may be changed without destroying activity, one skilled in the art may target areas not believed to be important for activity. For example, when similar polypeptides with similar activities from the same species or from other species are known, one skilled in the art may compare the amino acid sequence of a peptide to similar peptides. With such a comparison, one can identify residues and portions of the molecules that are conserved among similar polypeptides. It will be appreciated that changes in areas of a peptide that are not conserved relative to such similar peptides would be less likely to adversely affect the biological activity and/or structure of the peptide. One skilled in the art would also know that, even in relatively conserved regions, one may substitute chemically similar amino acids for the naturally occurring residues while retaining activity (conservative amino acid residue substitutions). Therefore, even areas that may be important for biological activity or for structure may be subject to conservative amino acid substitutions without destroying the biological activity or without adversely affecting the peptide structure.
[0173] Additionally, one skilled in the art can review structure-function studies identifying residues in similar peptides that are important for activity or structure. In view of such a comparison, one can predict the importance of amino acid residues in a peptide that correspond to amino acid residues that are important for activity or structure in similar peptides. One skilled in the art may opt for chemically similar amino acid substitutions for such predicted important amino acid residues of the peptides.
[0174] One skilled in the art can also analyze the three-dimensional structure and amino acid sequence in relation to that structure in similar polypeptides. In view of that information, one skilled in the art may predict the alignment of amino acid residues of a peptide with respect to its three dimensional structure. One skilled in the art may choose not to make radical changes to amino acid residues predicted to be on the surface of the protein, since such residues may be involved in important interactions with other molecules. Moreover, one skilled in the art may generate test variants containing a single amino acid substitution at each desired amino acid residue. The variants can then be screened using activity assays know to those skilled in the art. Such data could be used to gather information about suitable variants. For example, if one discovered that a change to a particular amino acid residue resulted in destroyed, undesirably reduced, or unsuitable activity, variants with such a change would be avoided. In other words, based on information gathered from such routine experiments, one skilled in the art can readily determine the amino acids where further substitutions should be avoided either alone or in combination with other mutations.
[0175] A number of scientific publications have been devoted to the prediction of secondary structure. See Moult J., Curr. Op. in Biotech., 7(4): 422-427 (1996), Chou et al., Biochemistry 13(2): 222-245 (1974); Chou et al., Biochemistry, 113(2): 211-222 (1974); Chou et al., Adv. Enzymol. Relat. Areas Mol. Biol., 47:45-148 (1978); Chou et al., Ann. Rev. Biochem., 47: 251-276 and Chou et al., Biophys. J., 26: 367-384 (1979). Moreover, computer programs are currently available to assist with predicting secondary structure. One method of predicting secondary structure is based upon homology modeling. For example, two polypeptides or proteins which have a sequence identity of greater than 30%, or similarity greater than 40% often have similar structural topologies. The recent growth of the protein structural data base (PDB) has provided enhanced predictability of secondary structure, including the potential number of folds within a polypeptide's or protein's structure. See Holm et al., Nucl. Acid. Res., 27(1): 244-247 (1999). It has been suggested (Brenner et al., Curr. Op. Struct. Biol, 7(3): 369-376 (1997)) that there are a limited number of folds in a given polypeptide or protein and that once a critical number of structures have been resolved, structural prediction will gain dramatically in accuracy.
[0176] Additional methods of predicting secondary structure include “threading” (Jones, D., Curr. Opin. Struct. Biol., 7(3): 377-87 (1997); Sippl et al., Structure, 4(1): 15-9 (1996)), “profile analysis” (Bowie et al., Science, 253: 164-170 (1991); Gribskov et al., Meth. Enzym., 183: 146-159 (1990); Gribskov et al., Proc. Nat. Acad. Sci., 84(13): 4355-8 (1987)), and “evolutionary linkage” (See Home, supra, and Brenner, supra).
[0177] Vehicles. This invention requires the presence of at least one vehicle (V 1 ) attached to a peptide through the N-terminus, C-terminus or a sidechain of one of the amino acid residues. Multiple vehicles may also be used; e.g., Fc's at each terminus or an Fc at a terminus and a PEG group at the other terminus or a sidechain. Exemplary vehicles include:
an Fc domain; other proteins, polypeptides, or peptides capable of binding to a salvage receptor; human serum albumin (HSA); a leucine zipper (LZ) domain; polyethylene glycol (PEG), including 5 kD, 20 kD, and 30 kD PEG, as well as other polymers; dextran;
and other molecules known in the art to provide extended half-life and/or protection from proteolytic degradation or clearance.
[0184] An Fc domain is the preferred vehicle. The Fc domain may be fused to the N or C termini of the peptides or at both the N and C termini. Fusion to the N terminus is preferred.
[0185] As noted above, Fc variants are suitable vehicles within the scope of this invention. A native Fc may be extensively modified to form an Fc variant in accordance with this invention, provided binding to the salvage receptor is maintained; see, for example WO 97/34631 and WO 96/32478. In such Fc variants, one may remove one or more sites of a native Fc that provide structural features or functional activity not required by the fusion molecules of this invention. One may remove these sites by, for example, substituting or deleting residues, inserting residues into the site, or truncating portions containing the site. The inserted or substituted residues may also be altered amino acids, such as peptidomimetics or D-amino acids. Fc variants may be desirable for a number of reasons, several of which are described below. Exemplary Fc variants include molecules and sequences in which:
1. Sites involved in disulfide bond formation are removed. Such removal may avoid reaction with other cysteine-containing proteins present in the host cell used to produce the molecules of the invention. For this purpose, the cysteine-containing segment at the N-terminus may be truncated or cysteine residues may be deleted or substituted with other amino acids (e.g., alanyl, seryl). In particular, one may truncate the N-terminal 20-amino acid segment of SEQ ID NO: 2 or delete or substitute the cysteine residues at positions 7 and 10 of SEQ ID NO: 2. Even when cysteine residues are removed, the single chain Fc domains can still form a dimeric Fc domain that is held together non-covalently. 2. A native Fc is modified to make it more compatible with a selected host cell. For example, one may remove the PA sequence near the N-terminus of a typical native Fc, which may be recognized by a digestive enzyme in E. coli such as proline iminopeptidase. One may also add an N-terminal methionine residue, especially when the molecule is expressed recombinantly in a bacterial cell such as E. coli . The Fc domain of SEQ ID NO: 2 is one such Fc variant. 3. A portion of the N-terminus of a native Fc is removed to prevent N-terminal heterogeneity when expressed in a selected host cell. For this purpose, one may delete any of the first 20 amino acid residues at the N-terminus, particularly those at positions 1, 2, 3, 4 and 5. 4. One or more glycosylation sites are removed. Residues that are typically glycosylated (e.g., asparagine) may confer cytolytic response. Such residues may be deleted or substituted with unglycosylated residues (e.g., alanine). 5. Sites involved in interaction with complement, such as the C1q binding site, are removed. For example, one may delete or substitute the EKK sequence of human IgG1. Complement recruitment may not be advantageous for the molecules of this invention and so may be avoided with such an Fc variant. 6. Sites are removed that affect binding to Fc receptors other than a salvage receptor. A native Fc may have sites for interaction with certain white blood cells that are not required for the fusion molecules of the present invention and so may be removed. 7. The ADCC site is removed. ADCC sites are known in the art; see, for example, Molec. Immunol. 29 (5): 633-9 (1992) with regard to ADCC sites in IgG1. These sites, as well, are not required for the fusion molecules of the present invention and so may be removed. 8. When the native Fc is derived from a non-human antibody, the native Fc may be humanized. Typically, to humanize a native Fc, one will substitute selected residues in the non-human native Fc with residues that are normally found in human native Fc. Techniques for antibody humanization are well known in the art.
[0194] Preferred Fc variants include the following. In SEQ ID NO: 2 ( FIG. 3 ), the leucine at position 15 may be substituted with glutamate; the glutamate at position 99, with alanine; and the lysines at positions 101 and 103, with alanines. In addition, one or more tyrosine residues can be replaced by phenyalanine residues.
[0195] An alternative vehicle would be a protein, polypeptide, peptide, antibody, antibody fragment, or small molecule (e.g., a peptidomimetic compound) capable of binding to a salvage receptor. For example, one could use as a vehicle a polypeptide as described in U.S. Pat. No. 5,739,277, issued Apr. 14, 1998 to Presta et al. Peptides could also be selected by phage display or RNA-peptide screening for binding to the FcRn salvage receptor. Such salvage receptor-binding compounds are also included within the meaning of “vehicle” and are within the scope of this invention. Such vehicles should be selected for increased half-life (e.g., by avoiding sequences recognized by proteases) and decreased immunogenicity (e.g., by favoring non-immunogenic sequences, as discovered in antibody humanization).
[0196] As noted above, polymer vehicles may also be used for V 1 . Various means for attaching chemical moieties useful as vehicles are currently available, see, e.g., Patent Cooperation Treaty (“PCT”) International Publication No. WO 96/11953, entitled “N-Terminally Chemically Modified Protein Compositions and Methods,” herein incorporated by reference in its entirety. This PCT publication discloses, among other things, the selective attachment of water soluble polymers to the N-terminus of proteins.
[0197] A preferred polymer vehicle is polyethylene glycol (PEG). The PEG group may be of any convenient molecular weight and may be linear or branched. The average molecular weight of the PEG will preferably range from about 2 kiloDalton (“kD”) to about 100 kD, more preferably from about 5 kD to about 50 kD, most preferably from about 5 kD to about 10 kD. The PEG groups will generally be attached to the compounds of the invention via acylation or reductive alkylation through a reactive group on the PEG moiety (e.g., an aldehyde, amino, thiol, or ester group) to a reactive group on the inventive compound (e.g., an aldehyde, amino, or ester group).
[0198] A useful strategy for the PEGylation of synthetic peptides consists of combining, through forming a conjugate linkage in solution, a peptide and a PEG moiety, each bearing a special functionality that is mutually reactive toward the other. The peptides can be easily prepared with conventional solid phase synthesis. The peptides are “preactivated” with an appropriate functional group at a specific site. The precursors are purified and fully characterized prior to reacting with the PEG moiety. Ligation of the peptide with PEG usually takes place in aqueous phase and can be easily monitored by reverse phase analytical HPLC. The PEGylated peptides can be easily purified by preparative HPLC and characterized by analytical HPLC, amino acid analysis and laser desorption mass spectrometry.
[0199] Polysaccharide polymers are another type of water soluble polymer which may be used for protein modification. Dextrans are polysaccharide polymers comprised of individual subunits of glucose predominantly linked by α1-6 linkages. The dextran itself is available in many molecular weight ranges, and is readily available in molecular weights from about 1 kD to about 70 kD. Dextran is a suitable water soluble polymer for use in the present invention as a vehicle by itself or in combination with another vehicle (e.g., Fc). See, for example, WO 96/11953 and WO 96/05309. The use of dextran conjugated to therapeutic or diagnostic immunoglobulins has been reported; see, for example, European Patent Publication No. 0 315 456, which is hereby incorporated by reference in its entirety. Dextran of about 1 kD to about 20 kD is preferred when dextran is used as a vehicle in accordance with the present invention.
[0200] Linkers. Any “linker” group is optional. When present, its chemical structure is not critical, since it serves primarily as a spacer. The linker is preferably made up of amino acids linked together by peptide bonds. Thus, in preferred embodiments, the linker is made up of from 1 to 30 amino acids linked by peptide bonds, wherein the amino acids are selected from the 20 naturally occurring amino acids. Some of these amino acids may be glycosylated, as is well understood by those in the art. In a more preferred embodiment, the 1 to 20 amino acids are selected from glycine, alanine, proline, asparagine, glutamine, and lysine. Even more preferably, a linker is made up of a majority of amino acids that are sterically unhindered, such as glycine and alanine. Thus, preferred linkers are polyglycines (particularly (Gly) 4 , (Gly) 5 ), poly(Gly-Ala), and polyalanines. Other specific examples of linkers are:
(Gly) 3 Lys(Gly) 4 ; (SEQ ID NO:40) (Gly) 3 AsnGlySer(Gly) 2 ; (SEQ ID NO:41) (Gly) 3 Cys(Gly) 4 ; (SEQ ID NO:42) and GlyProAsnGlyGly. (SEQ ID NO:43)
To explain the above nomenclature, for example, (Gly) 3 Lys(Gly) 4 means Gly-Gly-Gly-Lys-Gly-Gly-Gly-Gly (SEQ ID NO: 40). Combinations of Gly and Ala are also preferred. The linkers shown here are exemplary; linkers within the scope of this invention may be much longer and may include other residues.
[0201] Preferred linkers are amino acid linkers comprising greater than 5 amino acids, with suitable linkers having up to about 500 amino acids selected from glycine, alanine, proline, asparagine, glutamine, lysine, threonine, serine or aspartate. Linkers of about 20 to 50 amino acids are most preferred. One group of preferred linkers are those of the formulae
(SEQ ID NO:193) GSGSATGGSGSTASSGSGSATx 1 x 2 and (SEQ ID NO:194) GSGSATGGSGSTASSGSGSATx 1 x 2 GSGSATGGSGSTASSGSGSATx 3 x 4
[0202] wherein x 1 and x 3 are each independently basic or hydrophobic residues and x 2 and x 4 are each independently hydrophobic residues. Specific preferred linkers are:
(SEQ ID NO:59) GSGSATGGSGSTASSGSGSATHM (SEQ ID NO:190) GSGSATGGSGSTASSGSGSATGM (SEQ ID NO:191) GSGSATGGSGSTASSGSGSATGS, and (SEQ ID NO:192) GSGSATGGSGSTASSGSGSATHMGSGSATGGSGSTASSGSGSATHM.
[0203] Non-peptide linkers are also possible. For example, alkyl linkers such as —NH—(CH 2 ) s —C(O)—, wherein s=2-20 could be used. These alkyl linkers may further be substituted by any non-sterically hindering group such as lower alkyl (e.g., C 1 -C 6 ) lower acyl, halogen (e.g., Cl, Br), CN, NH 2 , phenyl, etc. An exemplary non-peptide linker is a PEG linker,
wherein n is such that the linker has a molecular weight of 100 to 5000 kD, preferably 100 to 500 kD. The peptide linkers may be altered to form derivatives in the same manner as described above.
[0204] Derivatives. The inventors also contemplate derivatizing the peptide and/or vehicle portion of the compounds. Such derivatives may improve the solubility, absorption, biological half life, and the like of the compounds. The moieties may alternatively eliminate or attenuate any undesirable side-effect of the compounds and the like. Exemplary derivatives include compounds in which:
1. The compound or some portion thereof is cyclic. For example, the peptide portion may be modified to contain two or more Cys residues (e.g., in the linker), which could cyclize by disulfide bond formation. 2. The compound is cross-linked or is rendered capable of cross-linking between molecules. For example, the peptide portion may be modified to contain one Cys residue and thereby be able to form an intermolecular disulfide bond with a like molecule. The compound may also be cross-linked through its C-terminus, as in the molecule shown below.
In Formula VIII, each “V 1 ” may represent typically one strand of the Fc domain. 3. One or more peptidyl [—C(O)NR—] linkages (bonds) is replaced by a non-peptidyl linkage. Exemplary non-peptidyl linkages are —CH 2 -carbamate [—CH 2 —OC(O)NR—], phosphonate, —CH 2 -sulfonamide [—CH 2 —S(O) 2 NR—], urea [—NHC(O)NH—], —CH 2 -secondary amine, and alkylated peptide [—C(O)NR 6 — wherein R 6 is lower alkyl]. 4. The N-terminus is derivatized. Typically, the N-terminus may be acylated or modified to a substituted amine. Exemplary N-terminal derivative groups include —NRR 1 (other than —NH 2 ), —NRC(O)R 1 , —NRC(O)OR 1 , —NRS(O) 2 R 1 , —NHC(O)NHR 1 , succinimide, or benzyloxycarbonyl-NH— (CBZ-NH—), wherein R and R 1 are each independently hydrogen or lower alkyl and wherein the phenyl ring may be substituted with 1 to 3 substituents selected from the group consisting of C 1 -C 4 alkyl, C 1 -C 4 alkoxy, chloro, and bromo. 5. The free C-terminus is derivatized. Typically, the C-terminus is esterified or amidated. Exemplary C-terminal derivative groups include, for example, —C(O)R 2 wherein R 2 is lower alkoxy or —NR 3 R 4 wherein R 3 and R 4 are independently hydrogen or C 1 -C 8 alkyl (preferably C 1 -C 4 alkyl). 6. A disulfide bond is replaced with another, preferably more stable, cross-linking moiety (e.g., an alkylene). See, e.g., Bhatnagar et al. (1996), J. Med. Chem. 39: 3814-9; Alberts et al. (1993) Thirteenth Am. Pep. Symp., 357-9. 7. One or more individual amino acid residues is modified. Various derivatizing agents are known to react specifically with selected sidechains or terminal residues, as described in detail below.
[0213] Lysinyl residues and amino terminal residues may be reacted with succinic or other carboxylic acid anhydrides, which reverse the charge of the lysinyl residues. Other suitable reagents for derivatizing alpha-amino-containing residues include imidoesters such as methyl picolinimidate; pyridoxal phosphate; pyridoxal; chloroborohydride; trinitrobenzenesulfonic acid; O-methylisourea; 2,4 pentanedione; and transaminase-catalyzed reaction with glyoxylate.
[0214] Arginyl residues may be modified by reaction with any one or combination of several conventional reagents, including phenylglyoxal, 2,3-butanedione, 1,2-cyclohexanedione, and ninhydrin. Derivatization of arginyl residues requires that the reaction be performed in alkaline conditions because of the high pKa of the guanidine functional group. Furthermore, these reagents may react with the groups of lysine as well as the arginine epsilon-amino group.
[0215] Specific modification of tyrosyl residues has been studied extensively, with particular interest in introducing spectral labels into tyrosyl residues by reaction with aromatic diazonium compounds or tetranitromethane. Most commonly, N-acetylimidizole and tetranitromethane are used to form O-acetyl tyrosyl species and 3-nitro derivatives, respectively.
[0216] Carboxyl sidechain groups (aspartyl or glutamyl) may be selectively modified by reaction with carbodiimides (R″—N═C═N—R″) such as 1-cyclohexyl-3-(2-morpholinyl-(4-ethyl) carbodiimide or 1-ethyl-3-(4-azonia-4,4-dimethylpentyl) carbodiimide. Furthermore, aspartyl and glutamyl residues may be converted to asparaginyl and glutaminyl residues by reaction with ammonium ions.
[0217] Glutaminyl and asparaginyl residues may be deamidated to the corresponding glutamyl and aspartyl residues. Alternatively, these residues are deamidated under mildly acidic conditions. Either form of these residues falls within the scope of this invention.
[0218] Cysteinyl residues can be replaced by amino acid residues or other moieties either to eliminate disulfide bonding or, conversely, to stabilize cross-linking. See, e.g., Bhatnagar et al. (1996), J. Med. Chem. 39: 3814-9.
[0219] Derivatization with bifunctional agents is useful for cross-linking the peptides or their functional derivatives to a water-insoluble support matrix or to other macromolecular vehicles. Commonly used cross-linking agents include, e.g., 1,1-bis(diazoacetyl)-2-phenylethane, glutaraldehyde, N-hydroxysuccinimide esters, for example, esters with 4-azidosalicylic acid, homobifunctional imidoesters, including disuccinimidyl esters such as 3,3′-dithiobis(succinimidylpropionate), and bifunctional maleimides such as bis-N-maleimido-1,8-octane. Derivatizing agents such as methyl-3-[(p-azidophenyl)dithio]propioimidate yield photoactivatable intermediates that are capable of forming cross-links in the presence of light. Alternatively, reactive water-insoluble matrices such as cyanogen bromide-activated carbohydrates and the reactive substrates described in U.S. Pat. Nos. 3,969,287; 3,691,016; 4,195,128; 4,247,642; 4,229,537; and 4,330,440 are employed for protein immobilization.
[0220] Carbohydrate (oligosaccharide) groups may conveniently be attached to sites that are known to be glycosylation sites in proteins. Generally, O-linked oligosaccharides are attached to serine (Ser) or threonine (Thr) residues while N-linked oligosaccharides are attached to asparagine (Asn) residues when they are part of the sequence Asn-X-Ser/Thr, where X can be any amino acid except proline. X is preferably one of the 19 naturally occurring amino acids other than proline. The structures of N-linked and O-linked oligosaccharides and the sugar residues found in each type are different. One type of sugar that is commonly found on both is N-acetylneuraminic acid (referred to as sialic acid). Sialic acid is usually the terminal residue of both N-linked and O-linked oligosaccharides and, by virtue of its negative charge, may confer acidic properties to the glycosylated compound. Such site(s) may be incorporated in the linker of the compounds of this invention and are preferably glycosylated by a cell during recombinant production of the polypeptide compounds (e.g., in mammalian cells such as CHO, BHK, COS). However, such sites may further be glycosylated by synthetic or semi-synthetic procedures known in the art.
[0221] Other possible modifications include hydroxylation of proline and lysine, phosphorylation of hydroxyl groups of seryl or threonyl residues, oxidation of the sulfur atom in Cys, methylation of the alpha-amino groups of lysine, arginine, and histidine side chains. Creighton, Proteins: Structure and Molecule Properties (W. H. Freeman & Co., San Francisco), pp. 79-86 (1983).
[0222] Compounds of the present invention may be changed at the DNA level, as well. The DNA sequence of any portion of the compound may be changed to codons more compatible with the chosen host cell. For E. coli which is the preferred host cell, optimized codons are known in the art. Codons may be substituted to eliminate restriction sites or to include silent restriction sites, which may aid in processing of the DNA in the selected host cell. The vehicle, linker and peptide DNA sequences may be modified to include any of the foregoing sequence changes.
[0223] Methods of Making
[0224] The compounds of this invention largely may be made in transformed host cells using recombinant DNA techniques. To do so, a recombinant DNA molecule coding for the peptide is prepared. Methods of preparing such DNA molecules are well known in the art. For instance, sequences coding for the peptides could be excised from DNA using suitable restriction enzymes. Alternatively, the DNA molecule could be synthesized using chemical synthesis techniques, such as the phosphoramidate method. Also, a combination of these techniques could be used.
[0225] The invention also includes a vector capable of expressing the peptides in an appropriate host. The vector comprises the DNA molecule that codes for the peptides operatively linked to appropriate expression control sequences. Methods of effecting this operative linking, either before or after the DNA molecule is inserted into the vector, are well known. Expression control sequences include promoters, activators, enhancers, operators, ribosomal binding sites, start signals, stop signals, cap signals, polyadenylation signals, and other signals involved with the control of transcription or translation.
[0226] The resulting vector having the DNA molecule thereon is used to transform an appropriate host. This transformation may be performed using methods well known in the art.
[0227] Any of a large number of available and well-known host cells may be used in the practice of this invention. The selection of a particular host is dependent upon a number of factors recognized by the art. These include, for example, compatibility with the chosen expression vector, toxicity of the peptides encoded by the DNA molecule, rate of transformation, ease of recovery of the peptides, expression characteristics, bio-safety and costs. A balance of these factors must be struck with the understanding that not all hosts may be equally effective for the expression of a particular DNA sequence. Within these general guidelines, useful microbial hosts include bacteria (such as E. coli sp.), yeast (such as Saccharomyces sp.) and other fungi, insects, plants, mammalian (including human) cells in culture, or other hosts known in the art.
[0228] Next, the transformed host is cultured and purified. Host cells may be cultured under conventional fermentation conditions so that the desired compounds are expressed. Such fermentation conditions are well known in the art. Finally, the peptides are purified from culture by methods well known in the art.
[0229] The compounds may also be made by synthetic methods. For example, solid phase synthesis techniques may be used. Suitable techniques are well known in the art, and include those described in Merrifield (1973), Chem. Polypeptides , pp. 335-61 (Katsoyannis and Panayotis eds.); Merrifield (1963), J. Am. Chem. Soc. 85: 2149; Davis et al. (1985), Biochem. Intl. 10: 394-414; Stewart and Young (1969), Solid Phase Peptide Synthesis ; U.S. Pat. No. 3,941,763; Finn et al. (1976), The Proteins (3rd ed.) 2: 105-253; and Erickson et al. (1976), The Proteins (3rd ed.) 2: 257-527. Solid phase synthesis is the preferred technique of making individual peptides since it is the most cost-effective method of making small peptides.
[0230] Compounds that contain derivatized peptides or which contain non-peptide groups may be synthesized by well-known organic chemistry techniques.
[0231] Uses of the Compounds
[0232] Compounds of this invention may be particularly useful in treatment of B-cell mediated autoimmune diseases. In particular, the compounds of this invention may be useful in treating, preventing, ameliorating, diagnosing or prognosing lupus, including systemic lupus erythematosus (SLE), and lupus-associated diseases and conditions. Other preferred indications include B-cell mediated cancers, including B-cell lymphoma.
[0233] The compounds of this invention can also be used to treat inflammatory conditions of the joints. Inflammatory conditions of a joint are chronic joint diseases that afflict and disable, to varying degrees, millions of people worldwide. Rheumatoid arthritis is a disease of articular joints in which the cartilage and bone are slowly eroded away by a proliferative, invasive connective tissue called pannus, which is derived from the synovial membrane. The disease may involve peri-articular structures such as bursae, tendon sheaths and tendons as well as extra-articular tissues such as the subcutis, cardiovascular system, lungs, spleen, lymph nodes, skeletal muscles, nervous system (central and peripheral) and eyes (Silberberg (1985), Anderson's Pathology, Kissane (ed.), II:1828). Osteoarthritis is a common joint disease characterized by degenerative changes in articular cartilage and reactive proliferation of bone and cartilage around the joint. Osteoarthritis is a cell-mediated active process that may result from the inappropriate response of chondrocytes to catabolic and anabolic stimuli. Changes in some matrix molecules of articular cartilage reportedly occur in early osteoarthritis (Thonar et al. (1993), Rheumatic disease clinics of North America, Moskowitz (ed.), 19:635-657 and Shinmei et al. (1992), Arthritis Rheum., 35:1304-1308). TALL-1, TALL-1R and modulators thereof are believed to be useful in the treatment of these and related conditions.
[0234] Compounds of this invention may also be useful in treatment of a number of additional diseases and disorders, including:
acute pancreatitis; ALS; Alzheimer's disease; asthma; atherosclerosis; autoimmune hemolytic anemia; cancer, particularly cancers related to B cells; cachexia/anorexia; chronic fatigue syndrome; cirrhosis (e.g., primary biliary cirrhosis); diabetes (e.g., insulin diabetes); fever; glomerulonephritis, including IgA glomerulonephritis and primary glomerulonephritis; Goodpasture's syndrome; Guillain-Barre syndrome; graft versus host disease; Hashimoto's thyroiditis; hemorrhagic shock; hyperalgesia; inflammatory bowel disease; inflammatory conditions of a joint, including osteoarthritis, psoriatic arthritis and rheumatoid arthritis; inflammatory conditions resulting from strain, sprain, cartilage damage, trauma, orthopedic surgery, infection or other disease processes; insulin-dependent diabetes mellitus; ischemic injury, including cerebral ischemia (e.g., brain injury as a result of trauma, epilepsy, hemorrhage or stroke, each of which may lead to neurodegeneration); learning impairment; lung diseases (e.g., ARDS); multiple myeloma; multiple sclerosis; Myasthenia gravis; myelogenous (e.g., AML and CML) and other leukemias; myopathies (e.g., muscle protein metabolism, esp. in sepsis); neurotoxicity (e.g., as induced by HIV); osteoporosis; pain; Parkinson's disease; Pemphigus; polymyositis/dermatomyositis; pulmonary inflammation, including autoimmune pulmonary inflammation; pre-term labor; psoriasis; Reiter's disease; reperfusion injury; septic shock; side effects from radiation therapy; Sjogren's syndrome; sleep disturbance; temporal mandibular joint disease; thrombocytopenia, including idiopathic thrombocytopenia and autoimmune neonatal thrombocytopenia; tumor metastasis; uveitis; and vasculitis.
[0286] Compounds of this invention may be administered alone or in combination with a therapeutically effective amount of other drugs, including analgesic agents, disease-modifying anti-rheumatic drugs (DMARDs), non-steroidal anti-inflammatory drugs (NSAIDs), and any immune and/or inflammatory modulators. Thus, compounds of this invention may be administered with:
Modulators of other members of the TNF/TNF receptor family, including TNF antagonists, such as etanercept (Enbrel™), sTNF-RI, onercept, D2E7, and Remicade™. Nerve growth factor (NGF) modulators. IL-1 inhibitors, including IL-1ra molecules such as anakinra and more recently discovered IL-1ra-like molecules such as IL-1Hy1 and IL-1Hy2; IL-1 “trap” molecules as described in U.S. Pat. No. 5,844,099, issued Dec. 1, 1998; IL-1 antibodies; solubilized IL-1 receptor, and the like. IL-6 inhibitors (e.g., antibodies to IL-6). IL-8 inhibitors (e.g., antibodies to IL-8). IL-18 inhibitors (e.g., IL-18 binding protein, solubilized IL-18 receptor, or IL-18 antibodies). Interleukin-1 converting enzyme (ICE) modulators. insulin-like growth factors (IGF-1, IGF-2) and modulators thereof. Transforming growth factor-β (TGF-β), TGF-β family members, and TGF-β modulators. Fibroblast growth factors FGF-1 to FGF-10, and FGF modulators. Osteoprotegerin (OPG), OPG analogues, osteoprotective agents, and antibodies to OPG-ligand (OPG-L). bone anabolic agents, such as parathyroid hormone (PTH), PTH fragments, and molecules incorporating PTH fragments (e.g., PTH (1-34)-Fc). PAF antagonists. Keratinocyte growth factor (KGF), KGF-related molecules (e.g., KGF-2), and KGF modulators. COX-2 inhibitors, such as Celebrex™ and Vioxx™. Prostaglandin analogs (e.g., E series prostaglandins). Matrix metalloproteinase (MMP) modulators. Nitric oxide synthase (NOS) modulators, including modulators of inducible NOS. Modulators of glucocorticoid receptor. Modulators of glutamate receptor. Modulators of lipopolysaccharide (LPS) levels. Anti-cancer agents, including inhibitors of oncogenes (e.g., fos, jun) and interferons. Noradrenaline and modulators and mimetics thereof.
[0310] Pharmaceutical Compositions
[0311] In General. The present invention also provides methods of using pharmaceutical compositions of the inventive compounds. Such pharmaceutical compositions may be for administration for injection, or for oral, pulmonary, nasal, transdermal or other forms of administration. In general, the invention encompasses pharmaceutical compositions comprising effective amounts of a compound of the invention together with pharmaceutically acceptable diluents, preservatives, solubilizers, emulsifiers, adjuvants and/or carriers. Such compositions include diluents of various buffer content (e.g., Tris-HCl, acetate, phosphate), pH and ionic strength; additives such as detergents and solubilizing agents (e.g., Tween 80, Polysorbate 80), anti-oxidants (e.g., ascorbic acid, sodium metabisulfite), preservatives (e.g., Thimersol, benzyl alcohol) and bulking substances (e.g., lactose, mannitol); incorporation of the material into particulate preparations of polymeric compounds such as polylactic acid, polyglycolic acid, etc. or into liposomes. Hyaluronic acid may also be used, and this may have the effect of promoting sustained duration in the circulation. Such compositions may influence the physical state, stability, rate of in vivo release, and rate of in vivo clearance of the present proteins and derivatives. See, e.g., Remington's Pharmaceutical Sciences, 18th Ed. (1990, Mack Publishing Co., Easton, Pa. 18042) pages 1435-1712 which are herein incorporated by reference in their entirety. The compositions may be prepared in liquid form, or may be in dried powder, such as lyophilized form. Implantable sustained release formulations are also contemplated, as are transdermal formulations.
[0312] Oral dosage forms. Contemplated for use herein are oral solid dosage forms, which are described generally in Chapter 89 of Remington's Pharmaceutical Sciences (1990), 18th Ed., Mack Publishing Co. Easton Pa. 18042, which is herein incorporated by reference in its entirety. Solid dosage forms include tablets, capsules, pills, troches or lozenges, cachets or pellets. Also, liposomal or proteinoid encapsulation may be used to formulate the present compositions (as, for example, proteinoid microspheres reported in U.S. Pat. No. 4,925,673). Liposomal encapsulation may be used and the liposomes may be derivatized with various polymers (e.g., U.S. Pat. No. 5,013,556). A description of possible solid dosage forms for the therapeutic is given in Chapter 10 of Marshall, K., Modern Pharmaceutics (1979), edited by G. S. Banker and C. T. Rhodes, herein incorporated by reference in its entirety. In general, the formulation will include the inventive compound, and inert ingredients which allow for protection against the stomach environment, and release of the biologically active material in the intestine.
[0313] Also specifically contemplated are oral dosage forms of the above inventive compounds. If necessary, the compounds may be chemically modified so that oral delivery is efficacious. Generally, the chemical modification contemplated is the attachment of at least one moiety to the compound molecule itself, where said moiety permits (a) inhibition of proteolysis; and (b) uptake into the blood stream from the stomach or intestine. Also desired is the increase in overall stability of the compound and increase in circulation time in the body. Moieties useful as covalently attached vehicles in this invention may also be used for this purpose. Examples of such moieties include: PEG, copolymers of ethylene glycol and propylene glycol, carboxymethyl cellulose, dextran, polyvinyl alcohol, polyvinyl pyrrolidone and polyproline. See, for example, Abuchowski and Davis, Soluble Polymer - Enzyme Adducts, Enzymes as Drugs (1981), Hocenberg and Roberts, eds., Wiley-Interscience, New York, N.Y., pp. 367-83; Newmark, et al. (1982), J. Appl. Biochem. 4:185-9. Other polymers that could be used are poly-1,3-dioxolane and poly-1,3,6-tioxocane. Preferred for pharmaceutical usage, as indicated above, are PEG moieties.
[0314] For oral delivery dosage forms, it is also possible to use a salt of a modified aliphatic amino acid, such as sodium N-(8-[2-hydroxybenzoyl] amino) caprylate (SNAC), as a carrier to enhance absorption of the therapeutic compounds of this invention. The clinical efficacy of a heparin formulation using SNAC has been demonstrated in a Phase II trial conducted by Emisphere Technologies. See U.S. Pat. No. 5,792,451, “Oral drug delivery composition and methods”.
[0315] The compounds of this invention can be included in the formulation as fine multiparticulates in the form of granules or pellets of particle size about 1 mm. The formulation of the material for capsule administration could also be as a powder, lightly compressed plugs or even as tablets. The therapeutic could be prepared by compression.
[0316] Colorants and flavoring agents may all be included. For example, the protein (or derivative) may be formulated (such as by liposome or microsphere encapsulation) and then further contained within an edible product, such as a refrigerated beverage containing colorants and flavoring agents.
[0317] One may dilute or increase the volume of the compound of the invention with an inert material. These diluents could include carbohydrates, especially mannitol, α-lactose, anhydrous lactose, cellulose, sucrose, modified dextrans and starch. Certain inorganic salts may also be used as fillers including calcium triphosphate, magnesium carbonate and sodium chloride. Some commercially available diluents are Fast-Flo, Emdex, STA-Rx 1500, Emcompress and Avicell.
[0318] Disintegrants may be included in the formulation of the therapeutic into a solid dosage form. Materials used as disintegrants include but are not limited to starch including the commercial disintegrant based on starch, Explotab. Sodium starch glycolate, Amberlite, sodium carboxymethylcellulose, ultramylopectin, sodium alginate, gelatin, orange peel, acid carboxymethyl cellulose, natural sponge and bentonite may all be used. Another form of the disintegrants are the insoluble cationic exchange resins. Powdered gums may be used as disintegrants and as binders and these can include powdered gums such as agar, Karaya or tragacanth. Alginic acid and its sodium salt are also useful as disintegrants.
[0319] Binders may be used to hold the therapeutic agent together to form a hard tablet and include materials from natural products such as acacia, tragacanth, starch and gelatin. Others include methyl cellulose (MC), ethyl cellulose (EC) and carboxymethyl cellulose (CMC). Polyvinyl pyrrolidone (PVP) and hydroxypropylmethyl cellulose (HPMC) could both be used in alcoholic solutions to granulate the therapeutic.
[0320] An antifrictional agent may be included in the formulation of the therapeutic to prevent sticking during the formulation process. Lubricants may be used as a layer between the therapeutic and the die wall, and these can include but are not limited to; stearic acid including its magnesium and calcium salts, polytetrafluoroethylene (PTFE), liquid paraffin, vegetable oils and waxes. Soluble lubricants may also be used such as sodium lauryl sulfate, magnesium lauryl sulfate, polyethylene glycol of various molecular weights, Carbowax 4000 and 6000.
[0321] Glidants that might improve the flow properties of the drug during formulation and to aid rearrangement during compression might be added. The glidants may include starch, talc, pyrogenic silica and hydrated silicoaluminate.
[0322] To aid dissolution of the compound of this invention into the aqueous environment a surfactant might be added as a wetting agent. Surfactants may include anionic detergents such as sodium lauryl sulfate, dioctyl sodium sulfosuccinate and dioctyl sodium sulfonate. Cationic detergents might be used and could include benzalkonium chloride or benzethonium chloride. The list of potential nonionic detergents that could be included in the formulation as surfactants are lauromacrogol 400, polyoxyl 40 stearate, polyoxyethylene hydrogenated castor oil 10, 50 and 60, glycerol monostearate, polysorbate 40, 60, 65 and 80, sucrose fatty acid ester, methyl cellulose and carboxymethyl cellulose. These surfactants could be present in the formulation of the protein or derivative either alone or as a mixture in different ratios.
[0323] Additives may also be included in the formulation to enhance uptake of the compound. Additives potentially having this property are for instance the fatty acids oleic acid, linoleic acid and linolenic acid.
[0324] Controlled release formulation may be desirable. The compound of this invention could be incorporated into an inert matrix which permits release by either diffusion or leaching mechanisms; e.g., gums. Slowly degenerating matrices may also be incorporated into the formulation, e.g., alginates, polysaccharides. Another form of a controlled release of the compounds of this invention is by a method based on the Oros therapeutic system (Alza Corp.), i.e., the drug is enclosed in a semipermeable membrane which allows water to enter and push drug out through a single small opening due to osmotic effects. Some enteric coatings also have a delayed release effect.
[0325] Other coatings may be used for the formulation. These include a variety of sugars which could be applied in a coating pan. The therapeutic agent could also be given in a film coated tablet and the materials used in this instance are divided into 2 groups. The first are the nonenteric materials and include methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, methylhydroxy-ethyl cellulose, hydroxypropyl cellulose, hydroxypropyl-methyl cellulose, sodium carboxy-methyl cellulose, providone and the polyethylene glycols. The second group consists of the enteric materials that are commonly esters of phthalic acid.
[0326] A mix of materials might be used to provide the optimum film coating. Film coating may be carried out in a pan coater or in a fluidized bed or by compression coating.
[0327] Pulmonary delivery forms. Also contemplated herein is pulmonary delivery of the present protein (or derivatives thereof). The protein (or derivative) is delivered to the lungs of a mammal while inhaling and traverses across the lung epithelial lining to the blood stream. (Other reports of this include Adjei et al., Pharma. Res . (1990) 7: 565-9; Adjei et al. (1990), Internatl. J. Pharmaceutics 63: 135-44 (leuprolide acetate); Braquet et al. (1989), J. Cardiovasc. Pharmacol. 13 (suppl. 5): s.143-146 (endothelin-1); Hubbard et al. (1989), Annals Int. Med. 3: 206-12 (α1-antitrypsin); Smith et al. (1989), J. Clin. Invest. 84: 1145-6 (α1-proteinase); Oswein et al. (March 1990), “Aerosolization of Proteins”, Proc. Symp. Resp. Drug Delivery II , Keystone, Colo. (recombinant human growth hormone); Debs et al. (1988), J. Immunol. 140: 3482-8 (interferon-γ and tumor necrosis factor α) and Platz et al., U.S. Pat. No. 5,284,656 (granulocyte colony stimulating factor).
[0328] Contemplated for use in the practice of this invention are a wide range of mechanical devices designed for pulmonary delivery of therapeutic products, including but not limited to nebulizers, metered dose inhalers, and powder inhalers, all of which are familiar to those skilled in the art. Some specific examples of commercially available devices suitable for the practice of this invention are the Ultravent nebulizer, manufactured by Mallinckrodt, Inc., St. Louis, Mo.; the Acorn II nebulizer, manufactured by Marquest Medical Products, Englewood, Colo.; the Ventolin metered dose inhaler, manufactured by Glaxo Inc., Research Triangle Park, N.C.; and the Spinhaler powder inhaler, manufactured by Fisons Corp., Bedford, Mass.
[0329] All such devices require the use of formulations suitable for the dispensing of the inventive compound. Typically, each formulation is specific to the type of device employed and may involve the use of an appropriate propellant material, in addition to diluents, adjuvants and/or carriers useful in therapy.
[0330] The inventive compound should most advantageously be prepared in particulate form with an average particle size of less than 10 μm (or microns), most preferably 0.5 to 5 μm, for most effective delivery to the distal lung.
[0331] Pharmaceutically acceptable carriers include carbohydrates such as trehalose, mannitol, xylitol, sucrose, lactose, and sorbitol. Other ingredients for use in formulations may include DPPC, DOPE, DSPC and DOPC. Natural or synthetic surfactants may be used. PEG may be used (even apart from its use in derivatizing the protein or analog). Dextrans, such as cyclodextran, may be used. Bile salts and other related enhancers may be used. Cellulose and cellulose derivatives may be used. Amino acids may be used, such as use in a buffer formulation.
[0332] Also, the use of liposomes, microcapsules or microspheres, inclusion complexes, or other types of carriers is contemplated.
[0333] Formulations suitable for use with a nebulizer, either jet or ultrasonic, will typically comprise the inventive compound dissolved in water at a concentration of about 0.1 to 25 mg of biologically active protein per mL of solution. The formulation may also include a buffer and a simple sugar (e.g., for protein stabilization and regulation of osmotic pressure). The nebulizer formulation may also contain a surfactant, to reduce or prevent surface induced aggregation of the protein caused by atomization of the solution in forming the aerosol.
[0334] Formulations for use with a metered-dose inhaler device will generally comprise a finely divided powder containing the inventive compound suspended in a propellant with the aid of a surfactant. The propellant may be any conventional material employed for this purpose, such as a chlorofluorocarbon, a hydrochlorofluorocarbon, a hydrofluorocarbon, or a hydrocarbon, including trichlorofluoromethane, dichlorodifluoromethane, dichlorotetrafluoroethanol, and 1,1,1,2-tetrafluoroethane, or combinations thereof. Suitable surfactants include sorbitan trioleate and soya lecithin. Oleic acid may also be useful as a surfactant.
[0335] Formulations for dispensing from a powder inhaler device will comprise a finely divided dry powder containing the inventive compound and may also include a bulking agent, such as lactose, sorbitol, sucrose, mannitol, trehalose, or xylitol in amounts which facilitate dispersal of the powder from the device, e.g., 50 to 90% by weight of the formulation.
[0336] Nasal delivery forms. Nasal delivery of the inventive compound is also contemplated. Nasal delivery allows the passage of the protein to the blood stream directly after administering the therapeutic product to the nose, without the necessity for deposition of the product in the lung. Formulations for nasal delivery include those with dextran or cyclodextran. Delivery via transport across other mucous membranes is also contemplated.
[0337] Dosages. The dosage regimen involved in a method for treating the above-described conditions will be determined by the attending physician, considering various factors which modify the action of drugs, e.g. the age, condition, body weight, sex and diet of the patient, the severity of any infection, time of administration and other clinical factors. Generally, the daily regimen should be in the range of 0.1-1000 micrograms of the inventive compound per kilogram of body weight, preferably 0.1-150 micrograms per kilogram.
[0338] Specific Preferred Embodiments
[0339] The inventors have determined preferred structures for the preferred peptides listed in Table 4 below. The symbol “Λ” may be any of the linkers described herein or may simply represent a normal peptide bond (i.e., so that no linker is present). Tandem repeats and linkers are shown separated by dashes for clarity.
TABLE 4 Preferred embodiments SEQ ID Sequence/structure NO: LPGCKWDLLIKQWVCDPL-Λ-V 1 44 V 1 -Λ-LPGCKWDLLIKQWVCDPL 45 LPGCKWDLLIKQWVCDPL-Λ-LPGCKWDLLIKQWVCDPL-Λ-V 1 46 V 1 -Λ-LPGCKWDLLIKQWVCDPL-Λ-LPGCKWDLLIKQWVCDPL 47 SADCYFDILTKSDVCTSS-Λ-V 1 48 V 1 -Λ-SADCYFDILTKSDVCTSS 49 SADCYFDILTKSDVTSS-Λ-SADCYFDILTKSDVTSS-Λ-V 1 50 V 1 -Λ-SADCYFDILTKSDVTSS-Λ-SADCYFDILTKSDVTSS 51 FHDCKWDLLTKQWVCHGL-Λ-V 1 52 V 1 -Λ-FHDCKWDLLTKQWVCHGL 53 FHDCKWDLLTKQWVCHGL-Λ-FHDCKWDLLTKQWVCHGL-Λ-V 1 54 V 1 -Λ-FHDCKWDLLTKQWVCHGL-Λ-FHDCKWDLLTKQWVCHGL 55
“V 1 ” is an Fc domain as defined previously herein. In addition to those listed in Table 4, the inventors further contemplate heterodimers in which each strand of an Fc dimer is linked to a different peptide sequence; for example, wherein each Fc is linked to a different sequence selected from Table 2.
[0340] All of the compounds of this invention can be prepared by methods described in PCT appl. no. WO 99/25044.
[0341] The invention will now be further described by the following working examples, which are illustrative rather than limiting.
EXAMPLE 1
Peptides
[0000] Peptide Phage Display
[0342] 1. Magnetic Bead Preparation
[0343] A. Fc-TALL-1 Immobilization on Magnetic Beads
[0344] The recombinant Fc-TALL-1 protein was immobilized on the Protein A Dynabeads (Dynal) at a concentration of 8 μg of Fc-TALL-1 per 100 μl of the bead stock from the manufacturer. By drawing the beads to one side of a tube using a magnet and pipetting away the liquid, the beads were washed twice with the phosphate buffer saline (PBS) and resuspended in PBS. The Fc-TALL-1 protein was added to the washed beads at the above concentration and incubated with rotation for 1 hour at room temperature. The Fc-TALL-1 coated beads were then blocked by adding bovine serum albumin (BSA) to 1% final concentration and incubating overnight at 4° C. with rotation. The resulting Fc-TALL-1 coated beads were then washed twice with PBST (PBS with 0.05% Tween-20) before being subjected to the selection procedures.
[0345] B. Negative Selection Bead Preparation
[0346] Additional beads were also prepared for negative selections. For each panning condition, 250 μl of the bead stock from the manufacturer was subjected to the above procedure (section 1A) except that the incubation step with Fc-TALL-1 was omitted. In the last washing step, the beads were divided into five 50 μl aliquots.
[0347] 2. Selection of TALL-1 Binding Phase
[0348] A. Overall Strategy
[0349] Two filamentous phage libraries, TN8-IX (5×10 9 independent transformants) and TN12-I (1.4×10 9 independent transformants) (Dyax Corp.), were used to select for TALL-1 binding phage. Each library was subjected to either pH 2 elution or ‘bead elution’ (section 2E). Therefore, four different panning conditions were carried out for the TALL-1 project (TN8-IX using the pH2 elution method, TN8-IX using the bead elution method, TN12-I the using pH2 elution method, and TN12-I using the bead elution method). Three rounds of selection were performed for each condition.
[0350] B. Negative Selection
[0351] For each panning condition, about 100 random library equivalent (5×10 11 pfu for TN8-IX and 1.4×10 11 pfu for TN12-I) was aliquoted from the library stock and diluted to 300 μl with PBST. After the last washing liquid was drawn out from the first 50 μl aliquot of the beads prepared for negative selections (section 1B), the 300 μl diluted library stock was added to the beads. The resulting mixture was incubated for 10 minutes at room temperature with rotation. The phage supernatant was drawn out using the magnet and added to the second 50 μl aliquot for another negative selection step. In this way, five negative selection steps were performed.
[0352] C. Selection Using the Fc-TALL-1 Protein Coated Beads
[0353] The phage supernatant after the last negative selection step (section 1B) was added to the Fc-TALL-1 coated beads after the last washing step (section 1A). This mixture was incubated with rotation for two hours at room temperature, allowing specific phage to bind to the target protein. After the supernatant is discarded, the beads were washed seven times with PBST.
[0354] D. pH2 Elution of Bound Phage
[0355] After the last washing step (section 2C), the bound phages were eluted from the magnetic beads by adding 200 μl of CBST (50 mM sodium citrate, 150 mM sodium chloride, 0.05% Tween-20, pH2). After 5 minute incubation at room temperature, the liquid containing the eluted phage were drawn out and transferred to another tube. The elution step was repeated again by adding 200 μl of CBST and incubating for 5 minutes. The liquids from two elution steps were added together, and 100 μl of 2 M Tris solution (pH 8) was added to neutralize the pH. 500 μl of Min A Salts solution (60 mM K 2 HPO 4 , 33 mM KH 2 PO 4 , 7.6 mM (NH 4 )SO 4 , and 1.7 mM sodium citrate) was added to make the final volume to 1 ml.
[0356] E. ‘Bead Elution’
[0357] After the final washing liquid was drawn out (section 2C), 1 ml of Min A salts solution was added to the beads. This bead mixture was added directly to a concentrated bacteria sample for infection (section 3A and 3B).
[0358] 3. Amplification
[0359] A. Preparation of Plating Cells
[0360] Fresh E. Coli . (XL-1 Blue MRF′) culture was grown to OD 600 =0.5 in LB media containing 12.5 μg/ml tetracycline. For each panning condition, 20 ml of this culture was chilled on ice and centrifuged. The bacteria pellet was resuspended in 1 ml of the Min A Salts solution.
[0361] B. Transduction
[0362] Each mixture from different elution methods (section 2D and 2E) was added to a concentrated bacteria sample (section 3A) and incubated at 37° C. for 15 minutes. 2 ml of NZCYM media (2XNZCYM, 50 μg/ml ampicillin) was added to each mixture and incubated at room temperature for 15 minutes. The resulting 4 ml solution was plated on a large NZCYM agar plate containing 50 μg/ml ampicillin and incubated overnight at 37° C.
[0363] C. Phage Harvesting
[0364] Each of the bacteria/phage mixture that was grown overnight on a large NZCYM agar plate (section 3B) was scraped off in 35 ml of LB media, and the agar plate was further rinsed with additional 35 ml of LB media. The resulting bacteria/phage mixture in LB media was centrifuged to pellet the bacteria away. 50 ml the of the phage supernatant was transferred to a fresh tube, and 12.5 ml of PEG solution (20% PEG8000, 3.5M ammonium acetate) was added and incubated on ice for 2 hours to precipitate phages. Precipitated phages were centrifuged down and resuspended in 6 ml of the phage resuspension buffer (250 mM NaCl, 100 mM Tris pH8, 1 mM EDTA). This phage solution was further purified by centrifuging away the remaining bacteria and precipitating the phage for the second time by adding 1.5 ml of the PEG solution. After a centrifugation step, the phage pellet was resuspended in 400 μl of PBS. This solution was subjected to a final centrifugation to rid of remaining bacteria debris. The resulting phage preparation was titered by a standard plaque formation assay (Molecular Cloning, Maniatis et al 3 rd Edition).
[0365] 4. Two More Rounds of Selection and Amplification.
[0366] In the second round, the amplified phage (10 10 pfu) from the first round (section 3C) was used as the input phage to perform the selection and amplification steps (sections 2 and 3). The amplified phage (10 10 pfu) from the 2 nd round in turn was used as the input phage to perform 3 rd round of selection and amplification (sections 2 and 3). After the elution steps (sections 2D and 2E) of the 3 rd round, a small fraction of the eluted phage was plated out as in the plaque formation assay (section 3C). Individual plaques were picked and placed into 96 well microtiter plates containing 100 μl of TE buffer in each well. These master plates were incubated in a 37° C. incubator for 1 hour to allow phages to elute into the TE buffer.
[0367] 5. Clonal Analysis (Phage ELISA and Sequencing)
[0368] The phage clones were analyzed by phage ELISA and sequencing methods. The sequences were ranked based on the combined results from these two assays.
[0369] A. Phage ELISA
[0370] An XL-1 Blue MRF′ culture was grown until OD 600 reaches 0.5. 30 μl of this culture was aliquoted into each well of a 96 well microtiter plate. 10 μl of eluted phage (section 4) was added to each well and allowed to infect bacteria for 15 min at room temperature. 130 μl of LB media containing 12.5 μg/ml of tetracycline and 50 μg/ml of ampicillin was added to each well. The microtiter plate was then incubated overnight at 37° C. The recombinant TALL-1 protein (1 μg/ml in PBS) was allowed to coat onto the 96-well Maxisorp plates (NUNC) overnight and 4° C. As a control, the recombinant Fc-Trail protein was coated onto a separate Maxisorp plate at the same molar concentration as the TALL-1 protein.
[0371] On the following day, liquids in the protein coated Maxisorp plates were discarded, and each well was blocked with 300 μl of 2% BSA solution at 37° C. for one hour. The BSA solution was discarded, and the wells were washed three times with the PBST solution. After the last washing step, 50 μl of PBST was added to each well of the protein coated Maxisorp plates. Each of the 50 μl overnight cultures in the 96 well microtiter plate was transferred to the corresponding wells of the TALL-1 coated plates as well as the control Fc-Trail coated plates. The 100 μl mixtures in the two kinds of plates were incubated for 1 hour at room temperature. The liquid was discarded from the Maxisorp plates, and the wells were washed five times with PBST. The HRP-conjugated anti-M13 antibody (Pharmacia) was diluted to 1:7,500, and 100 μl of the diluted solution was added to each well of the Maxisorp plates for 1 hour incubation at room temperature. The liquid was again discarded and the wells were washed seven times with PBST. 100 μl of tetramethylbenzidine (TMB) substrate (Sigma) was added to each well for the color reaction to develop, and the reaction was stopped with 50 μl of the 5 N H 2 SO 4 solution. The OD 450 was read on a plate reader (Molecular Devices).
[0372] B. Sequencing of the Phage Clones.
[0373] For each phage clone, the sequencing template was prepared by a PCR method. The following oligonucleotide pair was used to amplify about 500
nucleotide fragment: primer #1 (5′-CGGCGCAACTATCGGTATCAAGCTG-3′) (SEQ ID NO:56) and primer #2 (5′-CATGTACCGTAACACTGAGTTTCGTC-3′). (SEQ ID NO:57)
[0374] The following mixture was prepared for each clone.
Reagents volume (μL)/tube dH 2 O 26.25 50% glycerol 10 10B PCR Buffer (w/o MgCl 2 ) 5 25 mM MgCl 2 4 10 mM dNTP mix 1 100 μM primer 1 0.25 100 μM primer 2 0.25 Taq polymerase 0.25 Phage in TE (section 4) 3 Final reaction volume 50
[0375] The thermocycler (GeneAmp PCR System 9700, Applied Biosystems) was used to run the following program: 94° C. for 5 min; [94° C. for 30 sec, 55° C. for 30 sec, 72° C. for 45 sec.]×30 cycles; 72° C. for 7 min; cool to 4° C. The PCR product was checked by running 5 μl of each PCR reaction on a 1% agarose gel. The PCR product in the remaining 45 μl from each reaction was cleaned up using the QIAquick Multiwell PCR Purification kit (Qiagen), following the manufacturer's protocol. The resulting product was then sequenced using the ABI 377 Sequencer (Perkin-Elmer) following the manufacturer recommended protocol.
[0376] 6. Sequence Ranking and Consensus Sequence Determination
[0377] A. Sequence Ranking
[0378] The peptide sequences that were translated from variable nucleotide sequences (section 5B) were correlated to ELISA data. The clones that showed high OD 450 in the TALL-1 coated wells and low OD 450 in the Fc-Trail coated wells were considered more important. The sequences that occur multiple times were also considered important. Candidate sequences were chosen based on these criteria for further analysis as peptides or peptibodies. Five and nine candidate peptide sequences were selected from the TN8-IX and TN12-I libraries, respectively.
[0379] B. Consensus Sequence Determination
[0380] The majority of sequences selected from the TN12-I library contained a very conserved DBL motif. This motif was also observed in sequences selected from the TN8-IB library as well. Another motif, PFPWE (SEQ ID NO: 110) was also observed in sequences obtained from the TN8-IB library.
[0381] A consensus peptide, FHDC KWDLLTKOWV CHGL (SEQ ID NO: 58), was designed based on the DBL motif. Since peptides derived from the TN12-I library were the most active ones, the top 26 peptide sequences based on the above ranking criteria (section 5A) were aligned by the DBL motif The underlined “core amino acid sequence” was obtained by determining the amino acid that occur the most in each position. The two cysteines adjacent to the core sequences were fixed amino acids in the TN12-I library. The rest of the amino acid sequence in the consensus peptide is taken from one of the candidate peptides, TALL-1-12-10 (Table 2, SEQ ID NO: 37). The peptide and peptibody that was derived from this consensus sequence were most active in the B cell proliferation assay.
EXAMPLE 2
Peptibodies
[0382] A set of 12 TALL-1 inhibitory peptibodies (Table 5) was constructed in which a monomer of each peptide was fused in-frame to the Fc region of human IgG1. Each TALL-1 inhibitory peptibody was constructed by annealing the pairs of oligonucleotides shown in Table 6 to generate a duplex encoding the peptide and a linker comprised of 5 glycine residues and one valine residue as an NdeI to SalI fragment. These duplex molecules were ligated into a vector (pAMG21-RANK-Fc, described herein) containing the human Fc gene, also digested with NdeI and SalI. The resulting ligation mixtures were transformed by electroporation into E. coli strain 2596 cells (GM221, described herein). Clones were screened for the ability to produce the recombinant protein product and to possess the gene fusion having the correct nucleotide sequence. A single such clone was selected for each of the peptibodies. The nucleotide and amino acid sequences of the fusion proteins are shown in FIG. 4A through 4F .
TABLE 5 Peptide sequences and oligonucleotides used to generate TALL-1 inhibitory peptibodies. Peptibody Sense Antisense SEQ ID oligo- oligo- Peptibody NO Peptide Sequence nucleotide nucleotide TALL-1-8-1-a 29 PGTCFPFPWECTHA 2517-24 2517-25 TALL-1-8-2-a 30 WGACWPFPWECFKE 2517-26 2517-27 TALL-1-8-4-a 31 VPFCDLLTKHCFEA 2517-28 2517-29 TALL-1-12-4-a 32 GSRCKYKWDVLTKQCFHH 2517-30 2517-31 TALL-1-12-3-a 33 LPGCKWDLLIKQWVCDPL 2517-32 2517-33 TALL-1-12-5-a 34 SADCYFDILTKSDVCTSS 2517-34 2517-35 TALL-1-12-8-a 35 SDDCMYDQLTRMFICSNL 2517-36 2517-37 TALL-1-12-9-a 36 DLNCKYDELTYKEWCQFN 2521-92 2521-93 TALL-1-12-10-a 37 FHDCKYDLLTRQMVCHGL 2521-94 2521-95 TALL-1-12-11-a 38 RNHCFWDHLLKQDICPSP 2521-96 2521-97 TALL-1-12-14-a 39 ANQCWWDSLTKKNVCEFF 2521-98 2521-99 TALL-1- 58 FHDCKWDLLTKQWVCHGL 2551-48 2551-49 consensus
[0383]
TABLE 5B
TALL-1 inhibitory peptibodies.
Peptibody
SEQ ID
Peptibody
NO
Peptide Sequence
TALL-1-8-
111
MPGTCFPFPW
ECTHAGGGGG
VDKTHTCPPC
PAPELLGGPS
1-a
VFLFPPKPKD
TLMISRTPEV
TCVVVDVSHE
DPEVKFNWYV
DGVEVHNAKT
KPREEQYNST
YRVVSVLTVL
HQDWLNGKEY
KCKVSNKALP
APIEKTISKA
KGQPREPQVY
TLPPSRDELT
KNQVSLTCLV
KGFYPSDIAV
EWESNGQPEN
NYKTTPPVLD
SDGSFFLYSK
LTVDKSRWQQ
GNVFSCSVMH
EALHNHYTQK
SLSLSPGK
TALL-1-8-
112
MWGACWPFPW
ECFKEGGGGG
VDKTHTCPPC
PAPELLGGPS
2-a
VFLFPPKPKD
TLMISRTPEV
TCVVVDVSHE
DPEVKFNWYV
DGVEVHNAKT
KPREEQYNST
YRVVSVLTVL
HQDWLNGKEY
KCKVSNKALP
APIEKTISKA
KGQPREPQVY
TLPPSRDELT
KNQVSLTCLV
KGFYPSDIAV
EWESNGQPEN
NYKTTPPVLD
SDGSFFLYSK
LTVDKSRWQQ
GNVFSCSVMH
EALHNHYTQK
SLSLSPGK
TALL-1-8-
113
MVPFCDLLTK
HCFEAGGGGG
VDKTHTCPPC
PAPELLGGPS
4-a
VFLFPPKPKD
TLMISRTPEV
TCVVVDVSHE
DPEVKFNWYV
DGVEVHNAKT
KPREEQYNST
YRVVSVLTVL
HQDWLNGKEY
KCKVSNKALP
APIEKTISKA
KGQPREPQVY
TLPPSRDELT
KNQVSLTCLV
KGFYPSDIAV
EWESNGQPEN
NYKTTPPVLD
SDGSFFLYSK
LTVDKSRWQQ
GNVFSCSVMH
EALHNHYTQK
SLSLSPGK
TALL-1-12-
114
MGSRCKYKWD
VLTKQCFHHG
GGGGVDKTHT
CPPCPAPELL
4-a
GGPSVFLFPP
KPKDTLMISR
TPEVTCVVVD
VSHEDPEVKF
NWYVDGVEVH
NAKTKPREEQ
YNSTYRVVSV
LTVLHQDWLN
GKEYKCKVSN
KALPAPIEKT
ISKAKGQPRE
PQVYTLPPSR
DELTKNQVSL
TCLVKGFYPS
DIAVEWESNG
QPENNYKTTP
PVLDSDGSFF
LYSKLTVDKS
RWQQGNVFSC
SVMHEALHNH
YTQKSLSLSP
GK
TALL-1-12-
115
MLPGCKWDLL
IKQWVCDPLG
GGGGVDKTHT
CPPCPAPELL
3-a
GGPSVFLFPP
KPKDTLMISR
TPEVTCVVVD
VSHEDPEVKF
NWYVDGVEVH
NAKTKPREEQ
YNSTYRVVSV
LTVLHQDWLN
GKEYKCKVSN
KALPAPIEKT
ISKAKGQPRE
PQVYTLPPSR
DELTKNQVSL
TCLVKGFYPS
DIAVEWESNG
QPENNYKTTP
PVLDSDGSFF
LYSKLTVDKS
RWQQGNVFSC
SVMHEALHNH
YTQKSLSLSP
GK
TALL-1-12-
116
MSADCYFDIL
TKSDVCTSSG
GGGG VDKTHT
CPPCPAPELL
5-a
GGPSVFLFPP
KPKDTLMISR
TPEVTCVVVD
VSHEDPEVKF
NWYVDGVEVH
NAKTKPREEQ
YNSTYRVVSV
LTVLHQDWLN
GKEYKCKVSN
KALPAPIEKT
ISKAKGQPRE
PQVYTLPPSR
DELTKNQVSL
TCLVKGFYPS
DIAVEWESNG
QPENNYKTTP
PVLDSDGSFF
LYSKLTVDKS
RWQQGNVFSC
SVMHEALHNH
YTQKSLSLSP
GK
TALL-1-12-
117
MSDDCMYDQL
TRMFICSNLG
GGGGVDKTHT
CPPCPAPELL
8-a
GGPSVFLFPP
KPKDTLMISR
TPEVTCVVVD
VSHEDPEVKF
NWYVDGVEVH
NAKTKPREEQ
YNSTYRVVSV
LTVLHQDWLN
GKEYKCKVSN
KALPAPIEKT
ISKAKGQPRE
PQVYTLPPSR
DELTKNQVSL
TCLVKGFYPS
DIAVEWESNG
QPENNYKTTP
PVLDSDGSFF
LYSKLTVDKS
RWQQGNVFSC
SVMHEALHNH
YTQKSLSLSP
GK
TALL-1-12-
118
MDLNCKYDEL
TYKEWCQFNG
GGGGVDKTHT
CPPCPAPELL
9-a
GGPSVFLFPP
KPKDTLMISR
TPEVTCVVVD
VSHEDPEVKF
NWYVDGVEVH
NAKTKPREEQ
YNSTYRVVSV
LTVLHQDWLN
GKEYKCKVSN
KALPAPIEKT
ISKAKGQPRE
PQVYTLPPSR
DELTKNQVSL
TCLVKGFYPS
DIAVEWESNG
QPENNYKTTP
PVLDSDGSFF
LYSKLTVDKS
RWQQGNVFSC
SVMHEALHNH
YTQKSLSLSP
GK
TALL-1-12-
119
MFHDCKYDLL
TRQMVCHGLG
GGGGVDKTHT
CPPCPAPELL
10-a
GGPSVFLFPP
KPKDTLMISR
TPEVTCVVVD
VSHEDPEVKF
NWYVDGVEVH
NAKTKPREEQ
YNSTYRVVSV
LTVLHQDWLN
GKEYKCKVSN
KALPAPIEKT
ISKAKGQPRE
PQVYTLPPSR
DELTKNQVSL
TCLVKGFYPS
DIAVEWESNG
QPENNYKTTP
PVLDSDGSFF
LYSKLTVDKS
RWQQGNVFSC
SVMHEALHNH
YTQKSLSLSP
GK
TALL-1-12-
120
MRNHCFWDHL
LKQDICPSPG
GGGGVDKTHT
CPPCPAPELL
11-a
GGPSVFLFPP
KPKDTLMISR
TPEVTCVVVD
VSHEDPEVKF
NWYVDGVEVH
NAKTKPREEQ
YNSTYRVVSV
LTVLHQDWLN
GKEYKCKVSN
KALPAPIEKT
ISKAKGQPRE
PQVYTLPPSR
DELTKNQVSL
TCLVKGFYPS
DIAVEWESNG
QPENNYKTTP
PVLDSDGSFF
LYSKLTVDKS
RWQQGNVFSC
SVMHEALHNH
YTQKSLSLSP
GK
TALL-1-12-
121
MANQCWWDSL
TKKNVCEFFG
GGGGVDKTHT
CPPCPAPELL
14-a
GGPSVFLFPP
KPKDTLMISR
TPEVTCVVVD
VSHEDPEVKF
NWYVDGVEVH
NAKTKPREEQ
YNSTYRVVSV
LTVLHQDWLN
GKEYKCKVSN
KALPAPIEKT
ISKAKGQPRE
PQVYTLPPSR
DELTKNQVSL
TCLVKGFYPS
DIAVEWESNG
QPENNYKTTP
PVLDSDGSFF
LYSKLTVDKS
RWQQGNVFSC
SVMHEALHNH
YTQKSLSLSP
GK
TALL-1-
122
MFHDCKWDLL
TKQWVCHGLG
GGGGVDKTHT
CPPCPAPELL
consensus
GGPSVFLFPP
KPKDTLMISR
TPEVTCVVVD
VSHEDPEVKF
NWYVDGVEVH
NAKTKPREEQ
YNSTYRVVSV
LTVLHQDWLN
GKEYKCKVSN
KALPAPIEKT
ISKAKGQPRE
PQVYTLPPSR
DELTKNQVSL
TCLVKGFYPS
DIAVEWESNG
QPENNYKTTP
PVLDSDGSFF
LYSKLTVDKS
RWQQGNVFSC
SVMHEALHNH
YTQKSLSLSP
GK
TALL-1 12-
123
MLPGCKWDLL
IKQWVCDPLG
SGSATGGSGS
TASSGSGSAT
3 tandem
HMLPGCKWDL
LIKQWVCDPL
GGGGGVDKTH
TCPPCPAPEL
dimer
LGGPSVFLFP
PKPKDTLMIS
RTPEVTCVVV
DVSHEDPEVK
FNWYVDGVEV
HNAKTKPREE
QYNSTYRVVS
VLTVLHQDWL
NGKEYKCKVS
NKALPAPIEK
TISKAKGQPR
EPQVYTLPPS
RDELTKNQVS
LTCLVKGFYP
SDIAVEWESN
GQPENNYKTT
PPVLDSDGSF
FLYSKLTVDK
SRWQQGNVFS
CSVMHEALHN
HYTQKSLSLS
PGK
TALL-1
124
MFHDCKWDLL
TKQWVCHGLG
SGSATGGSGS
TASSGSGSAT
consensus
HMFHDCKWDL
LTKQWVCHGL
GGGGGVDKTH
TCPPCPAPEL
tandem
LGGPSVFLFP
PKPKDTLMIS
RTPEVTCVVV
DVSHEDPEVK
dimer
FNWYVDGVEV
HNAKTKPREE
QYNSTYRVVS
VLTVLHQDWL
NGKEYKCKVS
NKALPAPIEK
TISKAKGQPR
EPQVYTLPPS
RDELTKNQVS
LTCLVKGFYP
SDIAVEWESN
GQPENNYKTT
PPVLDSDGSF
FLYSKLTVDK
SRWQQGNVFS
CSVMHEALHN
HYTQKSLSLS
PGK
[0384] TABLE 6 Sequences of oligonucleotides used in peptibody construction. Oligo- nucleotide SEQ ID ID number NO Sequence 2517-24 71 TAT GCC GGG TAC TTG TTT CCC GTT CCC GTG GGA ATG CAC TCA CGC TGG TGG AGG CGG TGG GG 2517-25 72 TCG ACC CCA CCG CCT CCT GGA GCG TGA GTG CAT TCC CAC GGG AAG CCG AAA CAA GTA CCC GGC A 2517-26 73 TAT GTG GGG TGC TTG TTG GCC GTT CCC GTG GGA ATG TTT CAA AGA AGG TGG AGG CGG TGG GG 2517-27 74 TCG ACC CCA CCG CCT CCA CCT TCT TTG AAA CAT TCC CACGGG AAC GGC CAA CAAGCA CCC CAC A 2517-28 75 TAT GGT TCC GTT CTG TGA CCT GCT GAC TAA ACA CTG TTT CGA AGC TGG TGG AGG CGG TGG GG 2517-29 76 TCG ACC CCA CCG CCT CCA CCA GCT TCG AAA CAG TGT TTA GTC AGC AGG TCA CAGAAC GGA ACC A 2517-30 77 TAT GGG TTC TCG TTG TAA ATA CAA ATG GGA CGT TCT GAC TAA ACA GTG TTT CCA CCA CGG TGG AGG CGG TGG GG 2517-31 78 TCG ACC CCA CCG CCT CCA CCG TGG TGG AAA CAC TGT TTA GTC AGA ACG TCC CAT TTG TAT TTA CAA CGA GAA CCC A 2517-32 79 TAT GCT GCC GGG TTG TAA ATG GGA CCT GCT GAT CAA ACA GTG GGT TTG TGA CCC GCT GGG TGG AGG CGG TGG GG 2517-33 80 TCG ACC CCA CCG CCT CCA CCC AGC GGG TCA CAA ACG CAC TGT TTG ATC AGC AGG TCC CAT TTA CAA CCC GGC AGC A 2517-34 81 TAT GTC TGC TGA CTG TTA CTT CGA CAT CCT GAC TAA ATC TGA CGT TTG TAC TTC TTC TGG TGG AGG CGG TGG GG 2517-35 82 TCG ACC CCA CCG CCT CCA CCA GAA GAA GTA CAA ACG TCA GAT TTA GTC AGG ATG TCG AAG TAA CAG TCA GCA GAC A 2517-36 83 TAT GTC TGA CGA CTG TAT GTA CGA CCA GCT GAC TCG TAT GTT CAT CTG TTC TAA CCT GGG TGG AGG CGG TGG GG 2517-37 84 TCG ACC CCA CCG CCT CCA CCC AGG TTA GAA CAG ATG AAC ATA CGA GTC AGC TGG TCG TAC ATA CAG TCG TCA GAC A 2521-92 85 TAT GGA CCT GAA CTG TAA ATA CGA CGA ACT GAC TTA CAA AGA ATG GTG TCA GTT CAA CGG TGG AGG CGG TGG GG 25221-93 86 TCG ACC CCA CCG CCT CCA CCG TTG AAC TGA CAC CAT TCT TTG TAA GTC AGTTCG TCG TAT TTA CAG TTC AGG TCC A 2521-94 87 TAT GTT CCA CGA CTG TAA ATA CGA CCT GCT GAC TCG TCA GAT GGT TTG TCA CGG TCT GGG TGG AGG CGG TGG GG 2521-95 88 TCG ACC CCA CCG CCT CCA CCC AGA CCG TGA CAA ACC ATC TGA CGA GTC AGC AGG TCG TAT TTA CAG TCG TGG AAC A 2521-96 89 TAT GCG TAA CCA CTG TTT CTG GGA CCA CCT GCT GAA ACA GGA CAT CTG TCC GTC TCC GGG TGG AGG CGG TGG GG 2521-97 90 TCG ACC CCA CCG CCT CCA CCC GGA GAC GGA CAG ATG TCC TGT TTC AGC AGG TGG TCC CAG AAA CAG TGG TTA CGC A 2521-98 91 TAT GGC TAA CCA GTG TTG GTG GGA CTC TCT GCT GAA AAA AAA CGT TTG TGA ATT CTT CGG TGG AGG CGG TGG GG 2521-99 92 TCG ACC CCA CCG CCT CCA CCG AAG AAT TCA CAA ACG TTT TTT TTC AGC AGA GAG TCC CAC CAA CAC TGG TTA GCC A 2551-48 93 TAT GTT CCA CGA CTG CAA ATG GGA CCT GCT GAC CAA ACA GTG GGT TTG CCA CGG TCT GGG TGG AGG CGG TGG GG 2551-49 94 TCG ACC CCA CCG CCT CCA CCC AGA CCG TGG CAA ACC CAC TGT TTG GTC AGC AGG TCC CAT TTG CAG TCG TGG AAC A
pAMG21-RANK-Fc Vector
[0385] pAMG21. The expression plasmid pAMG21 (ATCC accession no. 98113) can be derived from the Amgen expression vector pCFM1656 (ATCC #69576) which in turn be derived from the Amgen expression vector system described in U.S. Pat. No. 4,710,473. The pCFM1656 plasmid can be derived from the described pCFM836 plasmid (U.S. Pat. No. 4,710,473) by:
destroying the two endogenous NdeI restriction sites by end filling with T4 polymerase enzyme followed by blunt end ligation; replacing the DNA sequence between the unique AatII and ClaI restriction sites containing the synthetic P L promoter with a similar fragment obtained from pCFM636 (U.S. Pat. No. 4,710,473) containing the P L promoter (see SEQ ID NO: 95 below); and
[0388] substituting the small DNA sequence between the unique ClaI and KpnI restriction sites with the oligonucleotide having the sequence of SEQ ID NO: 96.
SEQ ID NO:95: Aat II 5′ CTAATTCCGCTCTCACCTACCAAACAATGCCCCCCTGCAAAAAATAAATTCATAT- 3′ TGCAGATTAAGGCGAGAGTGGATGGTTTGTTACGGGGGGACGTTTTTTATTTAAGTATA- -AAAAAACATAGAGATAACCATCTGGGGTGATAAATTATCTCTGGCGGTGTTGACATAAA- -TTTTTTGTATGTGTATTGGTAGACGGCACTATTTAATAGAGACCGCCACAACTGTATTT- -TACCACTGGCGGTGATACTGAGCACAT 3′ -ATGGTGACCGCCACTATGACTCGTGTAGC 5′ ClaI SEQ ID NO:96: 5′ CGATTTGATTCTAGAAGGAGGAATAACATATGGTTAACGCGTTGGAATTCGGTAC 3′ 3′ TAAACTAAGATCTTCCTCCTTATTGTATACCAATTGCGCAACCTTAAGC 5′ Cla I Kpn I
[0389] The expression plasmid pAMG21 can then be derived from pCFM1656 by making a series of site-directed base changes by PCR overlapping oligonucleotide mutagenesis and DNA sequence substitutions. Starting with the BglII site (plasmid bp # 180) immediately 5′ to the plasmid replication promoter PcopB and proceeding toward the plasmid replication genes, the base pair changes are as shown in Table 7 below.
TABLE 7 Base pair changes resulting in pAMG21 pAMG21 bp # bp in pCFM1656 bp changed to in pAMG21 # 204 T/A C/G # 428 A/T G/C # 509 G/C A/T # 617 — insert two G/C bp # 679 G/C T/A # 980 T/A C/G # 994 G/C A/T # 1004 A/T C/G # 1007 C/G T/A # 1028 A/T T/A # 1047 C/G T/A # 1178 G/C T/A # 1466 G/C T/A # 2028 G/C bp deletion # 2187 C/G T/A # 2480 A/T T/A # 2499-2502 AGTG GTCA TCAC CAGT # 2642 TCCGAGC 7 bp deletion AGGCTCG # 3435 G/C A/T # 3446 G/C A/T # 3643 A/T T/A
[0390] The DNA sequence between the unique AatII (position #4364 in pCFM1656) and SacII (position #4585 in pCFM1656) restriction sites is substituted with the DNA sequence below (SEQ ID NO: 97).
[ AatII sticky end] 5′ GCGTAACGTATGCATGGTCTCC- (position #4358 in pAMG21) 3′ TGCACGCATTGCATACGTACCAGAGG- -CCATGCGAGAGTAGGGAACTGCCAGGCATCAAATAAAACGAAAGGCTCAGTCGAAAGACT- -GGTACGCTCTCATCCCTTGACGGTCCGTAGTTTATTTTGCTTTCCGAGTCAGCTTTCTGA- -GGGCCTTTCGTTTTATCTGTTGTTTGTCGGTGAACGCTCTCCTGAGTAGGACAAATCCGC- -CCCGGAAAGCAAAATAGACAACAAACAGCCACTTGCGAGAGGACTCATCCTGTTTAGGCG- -CGGGAGCGGATTTGAACGTTGCGAAGCAACGGCCCGGAGGGTGGCGGGCAGGACGCCCGC- -GCCCTCGCCTAAACTTGCAACGCTTCGTTGCCGGGCCTCCCACCGCCCGTCCTGCGGGCG- -CATAAACTGCCAGGCATCAAATTAAGCAGAAGGCCATCCTGACGGATGGCCTTTTTGCGT- -GTATTTGACGGTCCGTAGTTTAATTCGTCTTCCGGTAGGACTGCCTACCGGAAAAACGCA- AatII -TTCTACAAACTCTTTTGTTTATTTTTCTAAATACATTCAAATATGGACGTCGTACTTAAC- -AAGATGTTTGAGAAAACAAATAAAAAGATTTATGTAAGTTTATACCTGCAGCATGAATTG- -TTTTAAAGTATGGGCAATCAATTGCTCCTGTTAAAATTGCTTTAGAAATACTTTGGCAGC- -AAAATTTCATACCCGTTAGTTAACGAGGACAATTTTAACGAAATCTTTATGAAACCGTCG- -GGTTTGTTGTATTGAGTTTCATTTGCGCATTGGTTAAATGGAAAGTGACCGTGGGCTTAC- -CCAAACAACATAACTCAAAGTAAACGCGTAACCAATTTACCTTTCACTGGCACGCGAATG- -TACAGCCTAATATTTTTGAAATATCCCAAGAGCTTTTTCCTTCGCATGCCCACGCTAAAC- -ATGTCGGATTATAAAAACTTTATAGGGTTCTCGAAAAAGGAAGCGTACGGGTGCGATTTG- -ATTCTTTTTCTCTTTTGGTTAAATCGTTGTTTGATTTATTATTTGCTATATTTATTTTTC- -TAAGAAAAAGAGAAAACCAATTTAGCAACAAACTAAATAATAAACGATATAAATAAAAAG- -GATAATTATCAACTAGAGAAGGAACAATTAATGGTATGTTCATACACGCATGTAAAAATA- -CTATTAATAGTTGATCTCTTCCTTGTTAATTACCATACAAGTATGTGCGTACATTTTTAT- -AACTATCTATATAGTTGTCTTTCTCTGAATGTGCAAAACTAAGCATTCCGAAGCCATTAT- -TTGATAGATATATCAACAGAAAGAGACTTACACGTTTTGATTCGTAAGGCTTCGGTAATA- -TAGCAGTATGAATAGGGAAACTAAACCCAGTGATAAGACCTGATGATTTCGCTTCTTTAA- -ATCGTCATACTTATGCCTTTGATTTGGGTCACTATTCTGGACTACTAAAGCGAAGAAATT- -TTACATTTGGAGATTTTTTATTTACAGCATTGTTTTCAAATATATTCCAATTAATCGGTG- -AATGTAAACCTCTAAAAAATAAATGTCGTAACAAAAGTTTATATAAGGTTAATTAGCCAC- -AATGATTGGAGTTAGAATAATCTACTATAGGATCATATTTTATTAAATTAGCGTCATCAT- -TTACTAACCTCAATCTTATTAGATGATATCCTAGTATAAAATAATTTAATCGCAGTAGTA- -AATATTGCCTCCATTTTTTAGGGTAATTATCCAGAATTGAAATATCAGATTTAACCATAG- -TTATAACGGAGGTAAAAAATCCCATTAATAGGTCTTAACTTTATAGTCTAAATTGGTATC- -AATGAGGATAAATGATCGCGAGTAAATAATATTCACAATGTACCATTTTAGTCATATCAG- -TTACTCCTATTTACTAGCGCTCATTTATTATAAGTGTTACATGGTAAAATCAGTATAGTC- -ATAAGCATTGATTAATATCATTATTGCTTCTACAGGCTTTAATTTTATTAATTATTCTGT- -TATTCGTAACTAATTATAGTAATAACGAAGATGTCCGAAATTAAAATAATTAATAAGACA- -AAGTGTCGTCGGCATTTATGTCTTTCATACCCATCTCTTTATCCTTACCTATTGTTTGTC- -TTCACAGCAGCCGTAAATACAGAAAGTATGGGTAGAGAAATAGCAATGGATAACAAACAG- -GCAAGTTTTGCGTGTTATATATCATTAAAACGGTAATAGATTGACATTTGATTCTAATAA- -CGTTCAAAACGCACAATATATAGTAATTTTGCCATTATCTAACTGTAAACTAAGATTATT- -ATTGGATTTTTGTCACACTATTATATCGCTTGAAATACAATTGTTTAACATAAGTACCTG- -TAACCTAAAAACAGTGTGATAATATAGCGAACTTTATGTTAACAAATTGTATTCATGGAC- -TAGGATCGTACAGGTTTACGCAAGAAAATGGTTTGTTATAGTCGATTAATCGATTTGATT- -ATCCTAGCATGTCCAAATGCGTTCTTTTACCAAACAATATCAGCTAATTAGCTAAACTAA- -CTAGATTTGTTTTAACTAATTAAAGGAGGAATAACATATGGTTAACGCGTTGGAATTCGA- -GATCTAAACAAAATTGATTAATTTCCTCCTTATTCTATACCAATTGCGCAACCTTAAGCT- SacII -GCTCACTAGTGTCGACCTGCAGGGTACCATGGAAGCTTACTCGAGGATCCGCGGAAAGAA- -CGAGTGATCACAGCTGGACGTCCCATGGTACCTTCGAATGAGCTCCTAGGCGCCTTTCTT- -GAAGAAGAAGAAGAAAGCCCGAAAGGAAGCTGAGTTGGCTGCTGCCACCGCTCAGCAATA- -CTTCTTCTTCTTCTTTCCGGCTTTCCTTCGACTCAACCGACGACGGTGGCGACTCGTTAT- -ACTAGCATAACCCCTTGGGGCCTCTAAACGGGTCTTGAGGGGTTTTTTGCTGAAAGGAGG- -TGATCGTATTGGGGAACCCCGGAGATTTGCCCAGAACTCCCCAAAAAACGACTTTCCTCC- -AACCGCTCTTCACGCTCTTCACGC 3′ [ SacII sticky end] -TTGGCGAGAAGTGCGAGAAGTG 5′ (position #5904 in pAMG21)
[0391] During the ligation of the sticky ends of this substitution DNA sequence, the outside AatII and SacII sites are destroyed. There are unique AatII and SacII sites in the substituted DNA.
[0392] A gene encoding human RANK fused to the N-terminus of Fc was ligated into pAMG21 as an NdeI to BamHI fragment to generate Amgen Strain #4125. This construct was modified to insert a valine codon at the junction of RANK and Fc. The adjacent valine and aspartate codons create a unique SalI site. This allows for the fusion of peptides at the N-terminus of Fc3 between the unique NdeI and SalI sites. The RANK sequence is deleted upon insertion of a new NdeI-SalI fragment. The sequence of the vector is given in FIG. 5A through 5M .
[0393] GM221 (Amgen #2596). The Amgen host strain #2596 is an E. coli K-12 strain derived from Amgen strain #393, which is a derivative of E. coli W1485, obtained from the E. coli Genetic Stock Center, Yale University, New Haven, Conn. (CGSC strain 6159). It has been modified to contain both the temperature sensitive lambda repressor cI857s7 in the early ebg region and the lacI Q repressor in the late ebg region (68 minutes). The presence of these two repressor genes allows the use of this host with a variety of expression systems, however both of these repressors are irrelevant to the expression from luxP R . The untransformed host has no antibiotic resistances.
[0394] The ribosome binding site of the cI857s7 gene has been modified to include an enhanced RBS. It has been inserted into the ebg operon between nucleotide position 1170 and 1411 as numbered in Genbank accession number M64441Gb_Ba with deletion of the intervening ebg sequence. The sequence of the insert is shown below with lower case letters representing the ebg sequences flanking the insert shown below (SEQ ID NO: 98):
ttattttcgtGCGGCCGCACCATTATCACCGCCAGAGGTAAACTAGTCAA CACGCACGGTGTTAGATATTTATCCCTTGCGGTGATAGATTGAGCACATC GATTTGATTCTAGAAGGAGGGATAATATATGAGCACAAAAAAGAAACCAT TAACACAAGAGCAGCTTGAGGACGCACGTCGCCTTAAAGCAATTTATGAA AAAAAGAAAAATGAACTTGGCTTATCCCAGGAATCTGTCGCAGACAAGAT GGGGATGGGGCAGTCAGGCGTTGGTGCTTTATTTAATGGCATCAATGCAT TAAATGCTTATAACGCCGCATTGCTTACAAAAATTCTCAAAGTTAGCGTT GAAGAATTTAGCCCTTCAATCGCCAGAGAATCTACGAGATGTATGAAGCG GTTAGTATGCAGCCGTCACTTAGAAGTGAGTATGAGTACCCTGTTTTTTC TCATGTTCAGGCAGGGATGTTCTCACCTAAGCTTAGAACCTTTACCAAAG GTGATGCGGAGAGATGGGTAAGCACAACCAAAAAAGCCAGTGATTCTGCA TTCTGGCTTGAGGTTGAAGGTAATTCCATGACCGCACCAACAGGCTCCAA GCCAAGCTTTCCTGACGGAATGTTAATTCTCGTTGACCCTGAGCAGGCTG TTGAGCCAGGTGATTTCTGCATAGCCAGACTTGGGGGTGATGAGTTTACC TTCAAGAAACTGATCAGGGATAGCGGTCAGGTGTTTTTACAACCACTAAA CCCACAGTACCCAATGATCCCATGCAATGAGAGTTGTTCCGTTGTGGGGA AAGTTATCGCTAGTCAGTGGCCTGAAGAGACGTTTGGCTGATAGACTAGT GGATCCACTAGTgtttctgccc
[0395] The construct was delivered to the chromosome using a recombinant phage called MMebg-cI857s7 enhanced RBS #4 into F′tet/393. After recombination and resolution only the chromosomal insert described above remains in the cell. It was renamed F′tet/GM101. F′tet/GM101 was then modified by the delivery of a lacI Q construct into the ebg operon between nucleotide position 2493 and 2937 as numbered in the Genbank accession number M64441Gb_Ba with the deletion of the intervening ebg sequence. The sequence of the insert is shown below with the lower case letters representing the ebg sequences flanking the insert (SEQ ID NO: 99) shown below:
ggcggaaaccGACGTCGATCGAATGGTGCAAAACCTTTCGCGGTATGGCA TGATAGCGCCCGGAAGAGAGTCAATTCAGGGTGGTGAATGTGAAACCAGT AACGTTATACGATGTCGCAGAGTATGCCGGTGTCTCTTATCAGACCGTTT CCCGCGTGGTGAACCAGGCCAGCCACGTTTCTGCGAAAACGCGGGAAAAA GTCGAAGCGGCGATGGCGGAGCTGAATTACATTCCCAACCGCGTGGCAGA ACAACTGGCGGGCAAACAGTCGCTCGTGATTGGCGTTGCCACCTCCAGTC TGGCCCTGCACGCGCCGTCGCAAATTGTCGCGGCGATTAAATCTCGCGCC GATCAACTGGGTGCCAGCGTGGTGGTGTCGATGGTAGAACGAAGCGGCGT CGAAGCCTGTAAAGCGGCGGTGCACAATCTTCTCGCGCAACGCGTCAGTG GGGCTGATCATTAACTATCCGCTGGATGACCAGGATGCCATTGCTGTGGA AGCTGCCTGCAGTAATGTTCCGGCGTTATTTCTTGATGTCTGTGACCAGA CACGCATCAACAGTATTATTTTCTCCCATGAAGACGGTACGCGACTGGGC GTGGAGCATCTGGTCGCATTGGGTCAGCAGCAAATCGCGCTGTTAGCGGG CCCATTAAGTTCTGTCTCGGCGCGTCTGCGTCTGGCTGGCTGGCATAAAT ATCTCACTCGCAATCAAATTCAGCCGATAGCGGAACGGGAAGGCGACTGG AGTGGCATGTCCGGTTTTCAACAAACCATGCAAATGCTGAATGAGGGCAT CGTTCCCACTGCGATGCTGGTTGCCAACGATCAGATGGCGCTGGGCGCAA TGCGCGCCATTACCGAGTCCGGGCTGCGCGTTGGTGCGGATATCTCGGTA GTGGGATACGACGATACCGAAGACAGCTCATGTTATATGCCGCCGTTAAG CACCATCAAACAGGATTTCGCCTGCTGGGGCAAACCAGCGTGGACCGCTT GCTGCAACTCTCTCAGGGCCAGGGGGTGAAGGGCAATCAGCTGTTGCCCG TCTCACTGGTGAAAAGAAAAACCACCCTGGCGCCCAATACGCAAACCGCG TCTCCCCGCGCGTTGGCCGATTCATTAATGCAGCTGGCACGACAGGTTTC CGGACTGGAAAGCGGACAGTAAGGTACCATAGGATGCaggcacagga
[0396] The construct was delivered to the chromosome using a recombinant phage called AGebg-LacIQ#5 into F′tet/GM101. After recombination and resolution only the chromosomal insert described above remains in the cell. It was renamed F′tet/GM221. The F′tet episome was cured from the strain using acridine orange at a concentration of 25 μg/ml in LB. The cured strain was identified as tetracyline sensitive and was stored as GM221.
[0397] Expression in E. coli . Cultures of each of the pAMG21-Fc-fusion constructs in E. coli GM221 were grown at 37° C. in Luria Broth medium. Induction of gene product expression from the luxPR promoter was achieved following the addition of the synthetic autoinducer N-(3-oxohexanoyl)-DL-homoserine lactone to the culture media to a final concentration of 20 ng/ml. Cultures were incubated at 37° C. for a further 3 hours. After 3 hours, the bacterial cultures were examined by microscopy for the presence of inclusion bodies and were then collected by centrifugation. Refractile inclusion bodies were observed in induced cultures indicating that the Fc-fusions were most likely produced in the insoluble fraction in E. coli . Cell pellets were lysed directly by resuspension in Laemmli sample buffer containing 10% β-mercaptoethanol and were analyzed by SDS-PAGE. In each case, an intense Coomassie-stained band of the appropriate molecular weight was observed on an SDS-PAGE gel.
EXAMPLE 3
TALL-1 Peptibody Inhibits TALL-1 Mediated B Cell Proliferation
[0398] Mouse B lymphocytes were isolated from C57BL/6 spleens by negative selection. (MACS CD43 (Ly-48) Microbeads, Miltenyi Biotech, Auburn, Calif.). Purified (10 5 ) B cells were cultured in MEM, 10% heat inactivated FCS, 5×10 −5 M 2-mercaptoethanol, 100 U/ml penicillin, 100 μg/ml streptomycin) in triplicate in 96-well flat bottom tissue culture plates with 10 ng/ml TALL-1 protein and 2 μg/ml of Goat F(ab′) 2 anti-mouse IgM (Jackson ImmunoResearch Laboratory, West Grove, Pa.) with the indicated amount of recombinant TALL-1 peptibody for a period of 4 days at 37° C., 5% CO 2 . Proliferation was measured by the uptake of radioactive 3 [H] thymidine after an 18-hour incubation period.
EXAMPLE 4
TALL-1 Peptibody Blocks TALL-1 Binding to its Receptors
[0399] Reacti-Gel 6x (Pierce) were pre-coated with human AGP3 (also known as TALL-1, Khare et al., Proc. Natl. Acad. Sci. 97:3370-3375, 2000) and blocked with BSA. 100 pM and 40 pM of AGP3 peptibody samples were incubated with indicated various concentrations of human AGP3 at room temperature for 8 hours before run through the human AGP3-coated beads. The amount of the bead-bound peptibody was quantified by fluorescent (Cy5) labeled goat anti-human-Fc antibody (Jackson Immuno Research). The binding signal is proportional to the concentration of free peptibody at binding equilibrium. Dissociation equilibrium constant (K D ) was obtained from nonlinear regression of the competition curves using a dual-curve one-site homogeneous binding model (KinEx™ software). K D is about 4 pM for AGP3 peptibody (SEQ ID NO: 123) binding with human AGP3 ( FIG. 9 ).
[0400] To determine if this AGP3 peptibody can neutralize murine AGP3 binding as well as human AGP3, a BIAcore neutralizing assay was utilized. All experiments were performed on a BIAcore 3000 at room temperature. Human TACI-Fc protein (Xia et al, J. Exp. Med. 192, 137-144, 2000) was immobilized to a B1 chip using 10 mM Acetate pH 4.0 to a level of 2900RU. A blank flow cell was used as a background control. Using a running buffer of PBS (without calcium or magnesium) containing 0.005% P20, 1 nM recombinant human AGP3 (in running buffer plus, 0.1 mg/ml BSA) was incubated without and with indicated various amount of AGP3 peptibody (x axis) before injected over the surface of the receptor. Regeneration was performed using 8 mM glycine pH 1.5 for 1 minute, 25 mM 3-[cyclohexylamino]-1-propanesulfonic acid (CAPS) pH 10.5, 1 M NaCl for 1 minute. For determination of murine AGP3 binding, human his-tagged TACI was immobilized to 1000 RU in the above buffer. 5 nM recombinant murine AGP3 (in running buffer plus, 0.1 mg/ml BSA) was incubated without and with the various amounts indicated in FIG. 11 of AGP3 peptibody (x axis) before injected over the surface of the receptor. Regeneration was performed with 10 mM HCl pH2, twice for 30 seconds. Relative binding of both human and murine AGP3 at presence vs absence of AGP3 peptibody (SEQ ID NO: 123) was measured (y axis). Relative binding response was determined as (RU-RU blank/RUo-RU blank). The AGP3 peptibody (SEQ ID NO: 123) inhibited both human and murine AGP3 binding to its receptor TACI ( FIGS. 10A and 10B ). To examine if this AGP3 peptibody blocks AGP3 binding to all three receptors (TACI, BCMA and BAFFR), recombinant soluble receptor TACI, BCMA and BAFFR proteins were immobilized to CM5 chip. Using 10 mM acetate, pH4, human TACI-Fc was immobilized to 6300 RU, human BCMA-Fc to 5000 RU, and BAFFR-Fc to 6000 RU. 1 nM of recombinant human AGP3 (in running buffer containing 0.1 mg/ml BSA and 0.1 mg/ml Heparin) or 1 nM recombinant APRIL protein (Yu, et al., Nat. Immunol., 1:252-256, 2000) were incubated with indicated amount of AGP3 peptibody before injection over each receptor surface. Regeneration for the AGP3 experiment was done with 8 mM glycine, pH 1.5, for 1 minute, followed by 25 mM CAPS, pH 10.5, 1M NaCl for 1 minute. Regeneration for the APRIL experiment was performed with 8 mM glycine, pH 2, for one minute, followed by 25 mM CAPS, pH 10.5, 1 M NaCl for one minute. Relative binding of AGP3 or APRIL was measured. AGP3 peptibody (SEQ ID NO: 123) blocked AGP3 binding to all three receptors ( FIG. 11A ). AGP3 peptibody didn't affect APRIL binding to the receptors ( FIG. 11B ).
EXAMPLE 5
AGP3 Peptibody Blocks AGP3 Mediated B Cell Proliferation
[0401] Mouse B lymphocytes were isolated from C57BL/6 spleens by negative selection. (MACS CD43 (Ly-48) Microbeads, Miltenyi Biotech, Auburn, Calif.). Purified (10 5 ) B cells were cultured in minimal essential medium (MEM), 10% heat inactivated fetal calf serum (FCS), 5×10 −5 M 2-mercaptoethanol, 100 U/ml penicillin, 100 μg/ml streptomycin) in triplicate in 96-well flat bottom tissue culture plates with 10 ng/ml AGP3 (TALL-1) protein and 2 μg/ml of Goat F(ab′) 2 anti-mouse IgM (Jackson ImmunoResearch Laboratory, West Grove, Pa.) with the indicated amount of recombinant AGP3 peptibody (SEQ ID NO: 123) for a period of 4 days at 37° C., 5% CO 2 . Proliferation was measured by the uptake of radioactive 3 [H] thymidine after an 18-hour incubation period.
EXAMPLE 6
AGP3 Peptibody on AGP3-Stimulated Ig Production in Mice
[0402] Mice (Balb/c females of 9-14 weeks of age and 19-21 g of weight) were purchased from Charles River Laboratories, Wilmington, Mass. Mice (n=10) were treated i.p. with 1 mg/Kg of human AGP3 once a day for five consecutive days followed by 5 mg/Kg or 0.5 mg/Kg of AGP3 peptibody (SEQ ID NO: 123) or by saline or by 5 mg/Kg of human Fc. Other mice were left untreated. Mice were sacrificed on the sixth day to measure serum IgM and IgA, which were measured by ELISA. Briefly, plates were coated with capture antibodies specific for IgM or IgA (Southern Biotechnology Associates, Birmingham, Ala.), blocked, and added with dilutions of standard (IgM from Calbiochem, San Diego, Calif. and IgA from Southern Biotechnology Associates) or test samples. Captured Ig were revealed using biotinylated antibodies specific for IgM or IgA (Southern Biotechnology Associates), neutravidin-conjugated peroxidase (Pierce, Rockford, Ill.), and tetramethylbenzidine (TMB) microwell peroxidase substrate (KPL, Gaithersburg, Md.). Optical densities were quantitated in a Thermomax ELISA reader (Molecular Devices, Menlo Park, Calif.).
[0403] Human AGP3-stimulated increase in serum levels of IgM and IgA was blocked by 5 mg/Kg of the anti-AGP3 peptibody (SEQ ID NO: 123) and not by 0.5 mg/Kg ( FIGS. 12A and 12B ).
EXAMPLE 7
AGP3 Peptibody Reduced Spleen B Cell Number in Mice
[0404] Mice (as above, n=7) were treated i.p. for seven consecutive days with 5 mg/Kg or 1.5 mg/Kg or 0.5 mg/Kg of AGP3 peptibody (SEQ ID NO: 123) or with saline or with 5 mg/Kg of human Fc. Mice were sacrificed on the eighth day to count spleen B cell number. Spleens were collected in saline and gently disrupted by manual homogenization to yield a cell suspension. The total cell number was obtained with a H1E counter (Technicon, Tarrytown, N.Y.). Percentages of B cells were derived by immunofluorescence double staining and flow cytometry using fluorescein isothiocyanate (FITC)-conjugated and phycoerythrin (PE)-conjugated Ab against CD3 and B220, respectively (PharMingen, San Diego, Calif.) and a FACScan analyser (Becton and Dickinson, Mountain View, Calif.). B cells were identified for being CD3-B220+. At all doses, the AGP3 peptibody (SEQ ID NO: 123) decreased spleen B cell number in a dose-response fashion ( FIGS. 12A and 12B ) (SEQ ID NO: 123).
TABLE 8 AGP3 Pb Reduces B Cell Number in Normal Mice spleen B cell n = 7 dose (1/day × 7) (1 × 10e6) SD t test saline 51.3 9.6 Fc 5 mg/Kg 45.5 7.1 Peptibody 5 mg/Kg 20.1 3.8 1.37856E−05 1.5 mg/Kg 22.6 6.9 5.10194E−05 0.5 mg/Kg 25.8 3.6 0.000111409
EXAMPLE 8
AGP3 Peptibody Reduced Arthritis Severity in Mouse CIA Model
[0405] Eight to 12 week old DBA/1 mice (obtained from Jackson Laboratories, Bar Harbor, Me.) were immunized with bovine collagen type II (bCII) (purchased from University of Utah), emulsified in complete Freunds adjuvant (Difco) intradermally at the base of tail. Each injection was 100 μl containing 100 μg of bCII. Mice were boosted 3 weeks after the initial immunization with bCII emulsified in incomplete Freunds adjuvant. Treatment was begun from the day of booster immunization for 4 weeks. Mice were examined for the development of arthritis. As described before (Khare et al., J. Immunol. 155: 3653-9, 1995), all four paws were individually scored from 0-3. Therefore arthritis severity could vary from 0 to 12 for each animal. AGP3 (SEQ ID NO: 123) peptibody treatment significantly reduced the severity of arthritic scores ( FIG. 13 ).
[0406] Serum samples were taken one week after final treatment (day 35) for the analysis of anti-collagen antibody level. High binding ELISA plates (Immulon, Nunc) were coated with 50 μl of 4 μg/ml solution of bovine CII in carbonate buffer and plated were kept in cold overnight in the refrigerator. Plates were washed three times with cold water. 75 μl of blocking solution made up of PBS/0.05% tween 20/1% BSA was used to block non-specific binding for an hour. Samples were diluted (in blocking buffer) in dilution plates at 1:25, 1:100, 1:400, and 1:1600 and 25 μl of these samples were added to each well of the ELISA plate for a final dilution of 100, 400, 1600, and 6400 with a final volume of 100 μl/well. After incubation at room temperature for 3 hours, plates were washed three times again. 100 μl of secondary antibody diluted in blocking buffer (rat anti-mouse IgM, IgG2a, IgG2b, IgG1, IgG3-HRP) was added to each well and plates were incubated for at least 2 hours. Plates were washed four times. 100 μl of TMB solution (Sigma) was added to each well and the reaction was stopped using 50 μl of 25% sulfuric acid. Plates were read using an ELISA plate reader at 450 nm. OD was compared with a standard pool representing units/ml. AGP3 peptibody (SEQ ID NO: 123) treatment reduced serum anti-collagen II IgG1, IgG3, IgG2a, and IgG2b levels compared to PBS or Fc control treatment groups ( FIG. 14 ).
EXAMPLE 9
Treatment of AGP3 Peptibody in NZB/NZW Lupus Mice
[0407] Five month old lupus prone NZBx NZBWF1 mice were treated i.p. 3×/week for 8 weeks with PBS or indicated doses of AGP3 peptibody or human Fc proteins. Prior to the treatment, animals were pre-screened for protein in the urine with Albustix reagents strips (Bayer AG). Mice having greater than 100 mg/dl of protein in the urine were not included in the study. Protein in the urine was evaluated monthly throughout the life of the experiment. AGP3 peptibody (SEQ ID NO: 123) treatment led to delay of proteinuria onset and improved survival ( FIGS. 15A and 15B ).
[0408] AGP3 peptibody treatment reduced B cell number in mice. Balb/c mice received 7 daily intraperitoneal injections of indicated amount of AGP3 peptibody (SEQ ID NO: 123) or human Fc protein. On day 8, spleens were collected, and subject to FACS analysis for B220+B cells as set for in Table 8.
TABLE 8 AGP3 Pb Reduces B Cell Number in Normal Mice Spleen B cell n = 7 dose (1/day × 7) (1 × 10e6) SD t test saline 51.3 9.6 Fc 5 mg/Kg 45.5 7.1 Peptibody 5 mg/Kg 20.1 3.8 1.37856E−05 1.5 mg/Kg 22.6 6.9 5.10194E−05 0.5 mg/Kg 25.8 3.6 0.000111409
[0409] The invention now being fully described, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto, without departing from the spirit and scope of the invention as set forth herein. | The present invention concerns therapeutic agents that modulate the activity of TALL-1. In accordance with the present invention, modulators of TALL-1 may comprise an amino acid sequence Dz 2 Lz 4 wherein z 2 is an amino acid residue and z 4 is threonyl or isoleucyl. Exemplary molecules comprise a sequence of the formulae
(SEQ. ID. NO:100) a 1 a 2 a 3 CDa 6 La 8 a 9 a 10 Ca 12 a 13 a 14 , (SEQ. ID. NO:104) b 1 b 2 b 3 Cb 5 b 6 Db 8 Lb 10 b 11 b 12 b 13 b 14 Cb 16 b 17 b 18 (SEQ. ID. NO:105) c 1 c 2 c 3 Cc 5 Dc 7 Lc 9 c 10 c 11 c 12 c 13 c 14 Cc 16 c 17 c 18 (SEQ. ID. NO:106) d 1 d 2 d 3 Cd 5 d 6 d 7 WDd 10 Ld 13 d 14 d 15 Cd 16 d 17 d 18 (SEQ. ID. NO:107) e 1 e 2 e 3 Ce 5 e 6 e 7 De 9 Le 11 Ke 13 Ce 15 e 16 e 17 e 18 (SEQ. ID NO:109) f 1 f 2 f 3 Kf 5 Df 7 Lf 9 f 10 Qf 12 f 13 f 14
wherein the substituents are as defined in the specification. The invention further comprises compositions of matter of the formula
(X 1 ) a -V 1 -(X 2 ) b
wherein V 1 is a vehicle that is covalently attached to one or more of the above TALL-1 modulating compositions of matter. The vehicle and the TALL-1 modulating composition of matter may be linked through the N- or C-terminus of the TALL-1 modulating portion. The preferred vehicle is an Fc domain, and the preferred Fc domain is an IgG Fc domain. | 2 |
TECHNICAL FIELD
[0001] The present application relates generally to gas turbine engines and the like and more particularly relates to systems and methods for surge precursor detection and protection in a compressor by the measurement of power changes near the blade passing frequency.
BACKGROUND OF THE INVENTION
[0002] The compressor pressure ratio of a gas turbine engine generally is set at a pre-specified margin away from the surge/stall boundary (referred to as a surge margin or a stall margin), to avoid unstable compressor operation. In gas turbine engines used for power generation and other purposes, higher system efficiencies generally require higher compressor pressure ratios. Such higher pressure ratios, however, may necessitate a reduction in the operating surge/stall margin and hence a reduction in the response time if surge or stall conditions begin to develop.
[0003] One approach to compressor surge or stall detection is to monitor the health of the compressor by measuring the airflow and the pressure rise through the compressor. These pressure variations may be attributed to a number of different causes such as, for example, unstable combustion, rotating stall, and surge events on the compressor itself. To determine these pressure variations, the magnitude and rate of change of the pressure rise through the compressor may be monitored. This approach, however, does not offer prediction capabilities of rotating stall or surge. Moreover, this approach may fail to offer information in real-time to a control system with sufficient lead time to deal proactively with such events.
[0004] There is thus a desire for improved systems and methods for surge event precursor detection and protection. Such system and methods may determine a measure of surge likelihood in the compressor before an actual surge event itself with sufficient lead time to respond adequately so as to avoid damage thereto.
SUMMARY OF THE INVENTION
[0005] The present application thus provides a method of monitoring a compressor. The method may include the steps of determining a blade passing frequency, determining a power indication for a number of frequencies above and below the blade passing frequency, determining a ratio between a maximum power indication and a minimum power indication for the frequencies for a number of predetermined time intervals, and analyzing the ratio for each predetermined time interval to predict a surge condition of the compressor.
[0006] The present application further provides a compressor system. The system may include a speed sensor for obtaining a speed signal of a rotor, a pressure sensor for obtaining a number of dynamic pressure signals, and a controller configured to determine a blade passing frequency from the speed signal and to determine a surge indication signal based upon the dynamic power signals for a number of frequencies above and below the blade passing frequency.
[0007] The present application further provides a method of monitoring a compressor for surge conditions therein. The method may include the steps of determining a blade passing frequency based upon a rotor speed signal, determining a power indication for a number of frequencies above and below the blade passing frequency based upon a number of dynamic pressure signals, determining a ratio between a maximum power indication and a minimum power indication for the frequencies for a predetermined time interval, analyzing the ratio for each predetermined time interval to predict a surge condition of the compressor, and providing a surge indication signal to the compressor.
[0008] These and other features and improvements of the present application will become apparent to one of ordinary skill in the art upon review of the following detailed description when taken in conjunction with the several drawings and the appended claims.
BRIEF DESCRIPTION OF DRAWINGS
[0009] FIG. 1 is a cross-sectional view of a portion of a known compressor.
[0010] FIG. 2 is a schematic view of a compressor monitoring system as may be described herein.
[0011] FIG. 3 is a flow chart showing a Fast Fourier Transformation analysis for compressor monitoring as may be described herein.
[0012] FIG. 4 is a Fast Fourier Transform representation of the power changes near the blade passing frequency.
DETAILED DESCRIPTION
[0013] Generally described, a highly efficient gas turbine engine produces high electrical power output at a relatively low cost. The compressor in such a highly efficient gas turbine engine thus may be operated to produce a cycle pressure ratio that corresponds to a high firing temperature. As described above, the compressor may experience aerodynamic instabilities, such as, for example, stall and/or surge conditions, as the compressor is used to produce the high firing temperature or the high cycle pressure ratio. A compressor experiencing such stall and/or surge conditions may cause problems that may impact the components and the operational efficiency of the compressor and the overall gas turbine engine.
[0014] Referring now to the drawings, in which like numerals refer to like elements throughout the several views, FIG. 1 shows a portion of a compressor system 100 as may be described herein. The compressor system 100 may include a rotor 110 and a stator 120 . A flow of air 130 may be progressively compressed between the rotor 110 and the stator 120 . Typically, such compressor systems 100 may use multi-stage compression wherein the stator 120 may be configured to prepare and/or redirect the flow of air 130 from the rotor 110 to a subsequent rotor or to a plenum. Other types of compressor configurations may be used herein.
[0015] The compressor system 100 also may include a number of sensors 140 therein. The sensors 140 may sense a number of compressor operating parameters that may be indicative of stall and/or surge conditions. Specifically, the sensors 140 may include, for example, a speed sensor 150 configured to detect the rotational speed of the rotor 110 and a pressure sensor 160 configured to detect pressure dynamically about the rotor 110 . Other types of sensors 140 and other types of operating parameters may be used and detected herein.
[0016] FIG. 2 shows a compressor controller 170 as may be described herein and as may be used with the compressor system 100 . The compressor controller 170 may include a filter 180 , a storage medium 190 , a signal processor 200 , and a surge indicator 210 . Other components also may be used herein. The controller 170 may be in communication with the speed sensor 150 to obtain a rotor speed signal 220 and the pressure sensor 160 to obtain a dynamic pressure signal 230 . Other types of signals may be used herein.
[0017] The filter 180 receives these signals 220 , 230 and may be configured to remove undesired components such as, for example, high frequency noise from the sensed parameters. Other types of filtering may be used herein. As will be described in more detail below, buffering (or storing) of the filtered data over a period of time may be performed over a sample rate during a moving window. In one example, the moving window occurs over a period of about eight (8) seconds. Other window lengths may be used herein.
[0018] The storage medium 190 may be configured to store the filtered and/or buffered data. The signal processor 200 may be coupled to the storage medium 190 and configured to compute a Fast Fourier Transform analysis of the buffered data so as to determine a likelihood of surge. As will be described in more detail below, the signal processor 200 may include a speed-to-frequency converter 202 to convert the rotor speed signal 220 into a blade passing frequency. The blade passing frequency may be a product of the mechanical speed and the number of rotor blades. The signal processor 200 also may include a root mean square (RMS) converter 206 . The RMS converter 206 may compute the root mean square of the dynamic pressure signals 230 . The surge indicator 210 may be coupled to the signal processor 200 and configured to generate a surge indication signal 240 in response to the determination of a likelihood of surge. The surge indication signal 240 may be coupled to the overall compressor system 100 for corrective action such as shutdown and other actions in case of a detected likelihood of surge.
[0019] FIG. 3 shows a flow chart showing a Fast Fourier Transformation analysis 250 that may be used to determine the surge indication signal 240 based, in part, upon the rotor speed signal 220 and the dynamic pressure signals 230 , in block 260 , the blade passing frequency is determined from the rotor speed signal 220 produced by the speed sensor 150 and converted by the speed-to-frequency converter 202 . At block 270 , a power indication is determined for the frequency bands above and below the blade passing frequency via the dynamic pressure signals 230 . The power indication may be a root mean square of the dynamic pressure signals 230 as determined by the root mean square converter 206 . In this example, the power indications may be determined for the frequency bands of about 24 to about 4 hertz above and below the blade passing frequency. Other ranges may be used herein. The power indication in these frequency bands may be monitored about once a second. Other monitoring rates may be used herein.
[0020] At block 280 , a window of the power indications for each frequency for about eight (8) seconds may be collected. This window thus is an eight (8) second time history of the power in each frequency about the blade passing frequency. At block 290 , a minimum power indication and a maximum power indication is determined for each frequency in the window. In block 300 , a ratio of the maximum power indication to the minimum power indication is determined for each frequency. At block 310 , a maximum ratio of the ratios is determined. Depending upon the magnitude, the maximum ratio thus may serve as the surge indication signal 240 . At block 320 , the window may be updated at a rate of about once per second. Other update rates may be used.
[0021] FIG. 4 shows a representation of the Fast Fourier Transformation analysis 250 of the power changes near the blade passing frequency. At approximately 1=1200 seconds, the maximum ratio of the ratios increases substantially on the order of about 50% to 400% from the preceding time period (t=0-1200 seconds). As is shown, the occurrence of the maximum ratio of the ratios becomes more frequent, the stronger the likelihood of surge may exist given the relative changes in power. In addition, the greater the difference in magnitude of the ratios, the stronger the likelihood of surge may exist given the relative changes in power. In this case, a surge 330 takes place at about 1600 seconds where the magnitude of the maximum ratio of the ratios has increase by more than twice that of the preceding the maximum ratio of the ratios of the immediate past 400 seconds. Depending upon the magnitude, one of these spikes (or combinations thereof) may serve as the surge indication signal 240 .
[0022] The Fast Fourier Transformation analysis 250 thus measures the ability of the controller 170 of the compressor system 100 to maintain a desired speed set point. As a surge condition begins to emerge, the controller 170 may lose the ability to maintain the set point as indicated by the larger changes in the power near the blade passing frequency. The Fast Fourier Transformation analysis 250 thus shows the stability, or the lack thereof, of the compressor system 100 . The timely use of surge indication signal 240 therefore may avoid potential compressor damage.
[0023] Advantageously, long term Fast Fourier Transform analyses of compressor operational parameters may alleviate shortcomings in present day analysis and operating procedures. Furthermore, Fast Fourier Transform analysis may aid in capturing accurately abnormal pressure perturbations and hence may minimize false pressure surges by way of using scaling factors and the like. Moreover, these aforementioned advantages may help in predicting the onset of surge and/or stall condition accurately, before the compressor surges or stalls, and thus protect the compressor from damage by way of controlling the operating parameters suitably based on the prediction.
[0024] It should be apparent that the foregoing relates only to certain embodiments of the present application and that numerous changes and modifications may be made herein by one of ordinary skill in the art without departing from the general spirit and scope of the invention as defined by the following claims and the equivalents thereof. | The present application provides a method of monitoring a compressor. The method may include the steps of determining a blade passing frequency, determining a power indication for a number of frequencies above and below the blade passing frequency, determining a ratio between a maximum power indication and a minimum power indication for the frequencies for a number of predetermined time intervals, and analyzing the ratio for each predetermined time interval to predict a surge condition of the compressor. | 5 |
BACKGROUND OF THE INVENTION
[0001] The use of polyvinyl chloride (PVC)-based membranes as a commercial roofing material has come into widespread application in the roofing industry inasmuch as the material is flexible, waterproof and may be rapidly applied over a large area as new roofing, re-roofing or over existing roofing by a wide variety of methods, including mechanical attachment or gluing, with adjacent panels being joined by seams formed by heat-welding or solvent-welding. Such PVC-based roofing membranes typically comprise a three-ply composite of a layer of a polyester, e.g., polyethylene terephthalate (PET) or fiberglass fabric reinforcement sandwiched between two PVC films, the overall composite typically being 30 to 90 mils thick.
[0002] In the late 1990's waterproof flexible photovoltaic solar panels were developed that could be secured to roofing materials, including the aforesaid composite reinforced PVC membranes, thereby permitting the passive generation of electrical energy from rooftops by exposure to the sun, in essence giving roofs a dual utility of conventional protection from the elements and the generation of power.
[0003] A fundamental problem with securing such flexible photovoltaic solar panels to PVC roofing membranes lies in the incompatibility between (1) the adhesive typically used to glue the solar panels to the roofing membranes and (2) the conventional plasticizers used in PVC roofing membranes. More specifically, the PVC in the PVC roofing membrane contains certain plasticizers to enhance the membrane's flexibility, and the most widely used adhesive is a butyl rubber-containing asphalt adhesive either applied to the back side of the solar panels or in the form of two-sided tape. Over a period of two to four years the conventional plasticizers in the PVC layers of the reinforced PVC roofing membrane migrate from the PVC into the butyl rubber-containing asphalt adhesive, which softens the adhesive bond and compromises the elasticity of the PVC layer of the roofing membrane, which in turn weakens and/or destroys the bond between the solar panel and the roofing membrane and seriously compromises the flexibility that allows for expansion and contraction of both the PVC roofing membrane and the flexible solar panel. Although other classes of adhesives have been investigated for securing such solar panels to such PVC roofing membranes, they have more drawbacks than such a butyl-based adhesive. For example, acrylics lack sufficient bond flexibility as soon as they have been applied and are costly, while ethylene vinyl acetate hot melts require special dedicated factory equipment and narrow temperature ranges, making them essentially useless on a job site.
[0004] Accordingly, there is a need in the art for a method of securing conventional flexible solar panels to PVC roofing membranes that provides a strong, elastic, long-lasting bond between the two. This need is met by the present invention, which is summarized and described in detail below.
SUMMARY OF THE INVENTION
[0005] According to the present invention there is provided a method of installing a photovoltaic solar panel on a roof comprising the steps:
(a) securing a PVC membrane to a roofing support; (b) securing a plasticizer-containing PVC membrane to the PVC membrane of step (a); and (c) securing a flexible photovoltaic solar panel membrane to the plasticizer-containing PVC membrane of step (b)
wherein the plasticizer-containing PVC membrane contains PVC-compatible, butyl-resistant plasticizers, and optional additives such as antioxidants, flame retardants, stabilizers, colorants and other conventional additives known in the art
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0009] FIG. 1 is a cross-sectional view of an exemplary roof assembly of the invention that includes a flexible photovoltaic solar panel.
[0010] FIG. 2 is a perspective view of the roof assembly of FIG. 1 with elements of the assembly turned up on one corner.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0011] Referring to the drawings, wherein the same numerals refer to the same elements, there is shown in FIGS. 1-2 a roof assembly 1 comprising a polymeric roofing membrane 10 , typically consisting of two PVC layers 12 with a polyester or fiberglass reinforcement layer 14 interposed between the two PVC layers. Roofing membrane 10 may be secured in conventional fashion to a roof deck of virtually any construction, including frames or flat or curved surfaces of any material, including preexisting roofing or roofing membranes.
[0012] A second element of the roofing assembly is a plasticizer-containing PVC membrane 16 containing PVC-compatible, butyl-resistant plasticizers and optional antioxidants, flame retardants, stabilizers, colorants and other conventional additives known in the art. Exemplary such additives are phenolic antioxidants, antimony oxide and calcium carbonate as flame retardants and minor amounts of cadmium, barium and/or zinc as stabilizers. By “PVC-compatible and butyl-resistant” plasticizers is generally meant plasticizers that do not degrade PVC and that resist or minimize migration from PVC into butyl-based adhesives. Exemplary classes of such plasticizers include polyester-based plasticizers, such as phthalate-based esters, nitrile butyl rubbers, ketone/ethylene ester terpolymers (commercially available form DuPont as Elvaloy® and known polymeric plasticizers. Such a membrane 16 is commercially available as Asphalt-Resistant Vinyl Copolymer/Fabric Laminate from Canadian General Tower, Ltd. of Cambridge, Ontatrio. Membrane 16 may be secured to roofing membrane 10 by conventional heat-welding, solvent-welding or gluing. Heat-welding may be conducted by a heated platen, by the use of a hot air gun or by a dielectric welder. Solvent-welding may be conducted by applying a solvent in which PVC is soluble to roofing membrane 10 or to plasticizer-containing PVC membrane 16 or to both, followed by joining the two membranes; preferred solvents are tetrahydrofuran (THF) and methyl ethyl ketone (MEK). Gluing is preferably conducted by applying an ethylene/propylene copolymer-based adhesive to both membrane 10 and membrane 16 , then joining the two; a preferred adhesive of this type is an epoxy resin-based contact adhesive such as IB Vertibond from IB Roof Systems of Eugene, Oreg.; Sarnacol 2170 from Sika Canada, Inc.; or Pliobond 1746 from Bio-Rad Laboratories, Inc.
[0013] The third and final element of the roofing assembly is a flexible photovoltaic solar panel 20 , typically comprising a flexible substrate 20 a to which is adhered a solar module 20 b. Such panels are commercially available pre-assembled, typically with amorphous silicon photovoltaic cells encased within flexible, water-tight and transparent industrial fabrics and/or polymeric membranes and optionally including output cables and by-pass diodes. Suitable such solar panels 20 are the IB SolarWise 272 Watt and 544 Watt panels available from IB Roof Systems, Inc. of Eugene, Oreg. and the Uni-Solar® PVL 68 Watt and 544 Watt panels from United Solar Systems Corporation of Auburn Hills, Mich. Solar panel 20 is preferably glued to membrane 16 by a water-resistant contact adhesive such as a butyl rubber-containing asphalt adhesive or an ethylene/propylene copolymer adhesive containing butyl rubber, the latter being commercially available as a two-sided tape sold as SikaLastomer®-68 by Sika Corporation of Madison Heights, Mich. Butyl rubber-containing asphalt adhesives, commonly referred to as “rubberized asphalts,” typically comprise 40-60 wt % asphalt, 10-20 wt % of a rubber such as a styrene/butadiene block copolymer and up to 10 wt % of a plasticizer. Application of such an adhesive forms contact adhesive layer 18 between solar panel 20 and membrane 16 . In securing solar panel 20 to membrane 16 , it is preferred to leave suitable-sized longitudinal gaps, on the order of 2 cm wide, in the bond between solar panel 20 and membrane 16 , said gaps being in communication with the atmosphere, so as to permit the release of water vapor and gases and thereby help prevent delamination and maintain flexibility between panel 20 and membrane 16 upon expansion and contraction of the two.
[0014] The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow. | There is disclosed a method of adhering a flexible solar panel to a PVC-based roofing membrane that interposes a certain plasticizer-containing PVC membrane between the solar panel and the roofing membrane. | 8 |
BACKGROUND OF THE INVENTION
[0001] This invention relates generally to absorbent materials, and more specifically to, various litter compositions used for the control and removal of animal waste.
[0002] Known litter compositions are fabricated primarily from one of four materials: clay; vegetable matter such as grass, hay or alfalfa; wood chips, shavings or sawdust; and paper, such as shredded, flaked or pelletized paper. Known clay litters are prone to produce dust, and tracking out by the animal. Further, production of such clay litters results in a large quantity of dust being produced, sometimes referred to as clay fines. Clay fines present a problem to the litter manufacturers since the fines are a waste product and require disposal. In addition such clay products are not biodegradable.
[0003] Sodium bentonite clay is one known material used in the production of litters and is known for its excellent absorption and clumping qualities, as well as for odor retention. However, sodium bentonite is relatively expensive compared to other litter components. Therefore, attempts have been made to reduce the amount of sodium bentonite in clumping litters, for example, mixing pellets of non-absorbing clays with pellets of sodium bentonite clay in varying ratios. However, in these known litters, the properties which are most desirable in the sodium bentonite have been underutilized as most of the clumping and binding qualities of sodium bentonite occur at or near the surface of the clay.
SUMMARY OF THE INVENTION
[0004] In one aspect, an animal litter is disclosed which comprises non-swelling particles and a swelling agent coated on the non-swelling particles.
[0005] In another aspect, an absorbent material is disclosed which comprises clay particles in a size range of −10 to +50 mesh and a coating for the particles which comprises a bentonite powder.
[0006] In still another aspect, a clumping animal litter is disclosed which comprises clay particles in a size range of about −10 to +50 mesh which are agglomerated from clay fines of about −50 mesh size. A coating surrounds the particles.
[0007] In a further aspect, a method for manufacturing a clumping animal litter is disclosed which comprises agglomerating clay fines into particles and coating the particles with a powder.
[0008] In yet another aspect, a clumping animal litter is disclosed which comprises clay particles in a size range of about −10 to +50 mesh in size and bentonite powder of about 200 mesh size. The powder is applied as a coating to the particles in an amount of about 20% to about 40% by weight.
[0009] Additional features and advantages of the present invention are described in, and will be apparent from, the following Detailed Description of the Invention and the figures.
BRIEF DESCRIPTION OF THE FIGURES
[0010] FIG. 1 is a cross sectional view of a particle of coated clumping litter.
[0011] FIG. 2 is a clumping analysis of several samples of coated clumping litter.
[0012] FIG. 3 shows a screen analysis, a bulk density, and a moisture content for each sample analyzed in FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
[0013] Referring to FIG. 1 , absorbent particles 10 include clay fines agglomerated into clay particles 12 , which are coated with a powder 14 . In one embodiment, absorbent particles 10 are utilized in an animal litter. In alternative embodiments, the animal litter includes cat, dog, hamster and livestock litter. The clay fines used in the agglomeration process are about −50 mesh in size and are sometimes referred to as a clay seed base or a seed material. In an exemplary embodiment, clay particles 12 range in size from about −10 mesh to about +50 mesh, based on standard U.S. mesh.
[0014] In an exemplary embodiment, the clay fines are agglomerated using a pin mixer. A powder 14 is applied to particles 12 to form a coating. Powder 14 is the active ingredient of the litter. Exemplary coating powders include at least one of a sodium bentonite powder and a bentonite/guar gum blended powder. However, the powder coatings may be augmented with either or both of an odor control agent and an anti-microbial agent. Particle 10 is spherical in shape, the shape shown is by way of example only as it is contemplated that a host of shapes and sizes of coated particles can be produced by the embodiments and processes described herein.
[0015] One specific embodiment includes recovery of waste fines which include Calcium-Montmorillonite. The Calcium-Montmorillonite fines are agglomerated in a pin mixer using water as a binder. The agglomerated fines have a moisture content of about 20% to about 40%. In another embodiment, the fines have a moisture content of about 28% to about 34%. The agglomerated fines are then coated with a bentonite powder of about 200 mesh using a centrifugal coater or a rotary coater/dryer system.
[0016] In one embodiment, the clay fines are fed into a pin mixer using a screw extruder. Moisture (water) is added to the fines to act as a binder, in one embodiment about 28%, while in the extruder. The fines and the moisture result in a cake like substance as it enters the pin mixer. A pin mixer includes a shaft with a series of pins which breaks up the cake and results in the formation of small, spherically shaped particles which are separated from the cake-like batch using shaker screens. As previously described, in one embodiment, the clay fines are about −50 mesh in size and after addition of the moisture and the pin mixing process, resulting in particles 12 of between about −10 mesh and +50 mesh in size. Other methods are contemplated which include using binders of guar gum and water or starch and water.
[0017] Another embodiment utilizes a blend of clay fines and bentonite fines with water as a binder to produce particles 12 through the pin mixing process. Still another embodiment utilizes sodium bentonite fines with water as a binder to produce particles 12 of between about −10 mesh and +50 mesh in size through the pin mixing process. The agglomerated fines, including the clay and bentonite embodiment, or the bentonite embodiment, are then coated with a bentonite powder of about 200 mesh using a centrifugal coater or a rotary coater/dryer system for improved clumping capability.
[0018] In alternative embodiments, methods for coating an outer surface of clay particles 12 with powder 14 include utilization of at least one of a fluidized bed dryer, a semi-continuous centrifugal coater or a rotary coating and drying system. In the rotary system, clay particles 12 and powder 14 are tumbled in a drum to mix for about 60 seconds. The litter is then removed from the drum and the drum is heated to about 300° to about 400° Fahrenheit and the litter is returned to the drum and dried until about an 8% moisture content is obtained.
[0019] The resulting coated litter is typically in the −10 to +50 mesh size range, with a moisture content from about 15% to about 5%, preferably with a moisture content of about 8%. In one embodiment, the bentonite coating is about 20% to about 40% by weight of a coated particle. In an alternative embodiment, the bentonite coating is about 25% to about 35% by weight of a coated particle. In a further alternative embodiment, the bentonite coating is about 30% by weight of a coated particle.
[0020] In alternative method for producing the litter, the agglomerated fines are placed in a fluidized bed and bentonite coating is sprayed in a low concentration solution.
[0021] FIGS. 2 and 3 are an analysis of several samples of coated clumping litter which includes 70% by weight particles produced from fines as described above and 30% by weight 200 mesh bentonite coating. FIG. 2 illustrates clumping weight and clumping strength for several representative samples and is charted based upon wetting, for example, 15 minutes after wetting with a saline solution, and for 15 minutes, one hour, and 24 hours after being wetted with a standard urine sample. FIG. 3 shows a screen analysis, a bulk density, and a moisture content for each sample analyzed in FIG. 2 . The screen analysis indicates a weight and a percentage for each sample that passed through standard mesh screens, for example, 8, 12, 14, 20, 40, and 50 mesh screens.
[0022] The litter resulting from the compositions and methods described above has superior clumping properties as the active clumping agent is kept on the surface of the particles, where the clumping bonds are formed. in addition, the litter has a dust content which is lower than known clumping litters, resulting in less tracking, as the coating processes described above result in a shell being formed around the agglomerated particles. Further, the litter is easier to remove from litter boxes than known clumping litters as the litter described herein is less likely to attach to litter boxes.
[0023] In the above described embodiments, coating with bentonite provides a litter which includes the clumping and absorption qualities of a litter which is composed solely of sodium bentonite. However, due to the coating process, the amount by weight of sodium bentonite is reduced over known clumping litters, resulting in more efficient use of the sodium bentonite while providing a production cost savings over those litters with higher percentage amounts of sodium bentonite. In addition, the coated litter produced provides a lighter weight product and has a unique, homogeneous appearance that appeals to consumers. Further, the agglomeration process results in a utilization of clay product fines, which heretofore have been considered waste products, and since clay is not biodegradable, clay fines have traditionally required space for disposal.
[0024] While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.
[0025] It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims. | A clumping animal litter is disclosed which includes non-swelling particles and a swelling agent coated on the non-swelling particles. In one embodiment, the non-swelling particles are manufactured by agglomerating clay fines. | 8 |
TECHNICAL FIELD
This invention relates to signal equalizers and, in particular, to adaptive fade equalizers.
BACKGROUND OF THE INVENTION
It has been found that amplitude and delay distortion resulting from multipath fading can, under certain conditions, be a major cause of transmission deterioration in both digital and FM radio communications systems. Experimental and analytical evidence indicate that outages of wideband digital systems, caused by this phenomenon (i.e., frequency selective fading), may exceed system performance objectives. This means that techniques for handling flat fades, such as AGC, will not be adequate to maintain satisfactory wideband digital transmission, and that additional correction will be required. Even the use of space diversity techniques will not eliminate completely the problems associated with selective fading. The use of some form of equalization will still be required to achieve the desired level of system performance. (See, for example, U.S. Pat. No. 4,261,056, filed July 16, 1979, and assigned to applicant's assignee.)
The problem, however, is that signal fading resulting from multipath transmission is basically unpredictable. Accordingly, the compensation introduced by a fade equalizer must be capable of automatically adapting to the changing signal conditions. One such adaptive equalizer, employing feedback techniques, is disclosed by H. Miedema in his copending application, Ser. No. 158,404, filed June 11, 1980, now U.S. Pat. No. 4,330,764. While this equalizer compensates the amplitude distortion, it does not provide delay equalization in the case of nonminimum phase fades. Indeed, for a nonminimum phase fade, the delay distortion is doubled. In another variation of the feedback equalizer, disclosed in a copending application by G. D. Martin, Ser. No. 203,645, filed Nov. 3, 1980 now U.S. Pat. No. 4,361,892, all-pass networks, which are more difficult to realize, are used to compensate the delay distortion for both minimum and nonminimum phase fades.
SUMMARY OF THE INVENTION
In its most general form, an adaptive equalizer, in accordance with the present invention, comprises a cascade of feed-forward stages, each one of which includes: a first parallel wavepath including a first adjustable attenuator; a second parallel wavepath including a second adjustable attenuator and an adjustable delay network; and means for combining the signals in the two wavepaths in a common output.
When used as an adaptive fade equalizer, control means are provided for adjusting the equalizer parameters in response to changes in the fade characteristics.
It is an advantage of the present invention that because of the unique relationship among the elements of the different equalizer stages, all of the stages can be adjusted simultaneously. In particular, it is shown that only the attenuator elements need be adjusted dynamically during fade conditions. The delay elements can be fixed and the fade notch translated into frequency coincidence with the equalizer bump frequency.
It is a further advantage of the invention that it produces simultaneous amplitude and delay equalization of the received signal for both minimum and nonminimum phase fades. Finally, by using only feed-forward sections, instead of feedback, instability problems during nonminimum phase fades are avoided.
An alternative, transversal filter equivalent of the feed-forward equalizer is also disclosed.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a portion of a radio communication system including a multipath transmission medium;
FIG. 2 shows an adaptive equalizer in accordance with the present invention;
FIG. 3 shows, in block diagram, an arrangement for automatically controlling the parameters of the equalizer of FIG. 2;
FIG. 4 shows an illustrative embodiment of a fade notch detector and oscillator control voltage generator;
FIG. 5, included for purposes of explanation, shows the delay response of a frequency selective fade for the minimum and nonminimum phase cases;
FIG. 6 shows an illustrative embodiment of a phase analyzer;
FIG. 7 shows an illustrative embodiment of an equalizer gain adjustment circuit;
FIGS. 8 and 9, included for purposes of explanation, show the equalizer input signal and the equalizer output signal for various gain adjustments;
FIGS. 10 and 11 show a flow chart for adjusting the equalizer gain parameters; and
FIG.12 shows an alternative, transversal filter equivalent of the feed-forward equalizer of FIG. 2.
DETAILED DESCRIPTION
While the present invention can be employed in any situation wherein signal equalization is desired, in the discussion that follows its use as a multipath fade equalizer will be described.
Referring to the drawings, FIG. 1 shows a portion of a radio communication system including a transmission source 9, a multipath transmission medium 10 and, at the receiver 8, an adaptive equalizer 11. In a moderately broadband system, the transmission medium 10 can be reasonably represented by a two-path model. Thus, in FIG. 1 medium 10 is shown to include a direct path 15 between the transmission source and the receiver, and an indirect path 16. The former is characterized by a gain factor a. The latter is characterized by a relative delay τ and a gain factor α, where τ, α and a vary as functions of time.
At the receiver, the total received signal R(jω), includes a direct path component and an indirect path component and is given by
R(jω)=a(1+be.sup.-jωτ)T(jω) (1)
where
a is a scale parameter;
b is a shape parameter;
τ a fixed delay difference in the channel;
ab=α;
and
both the received signal R(jω) and the transmitted signal T(jω) are complex functions.
It can be shown that when the amplitude of the delayed signal is less than that of the direct signal (i.e., b<1), the transmission medium is a so-called "minimum phase shift network." When the amplitude of the delayed signal is greater than the direct path signal (i.e., b>1), the medium has the characteristics of a "nonminimum phase shift network." (For a discussion of minimum phase shift networks, see "Network Analysis and Feedback Amplifier Design," by H. W. Bode, published by D. Van Nostrand Company, Inc. of New York, Fourth Printing, pp. 242 et seq.)
A fade notch occurs when the two received signal components destructively interfere. The function of the equalizer is to reduce the inband amplitude and delay distortion produced by the fade such that the equalized signal, E N (jω), at the output of the equalizer is substantially the same as the transmitted signal T(jω).
FIG. 2, now to be considered, shows an adaptive equalizer in accordance with the present invention comprising N feed-forward stages. Each stage comprises: a first parallel wave path 1-1, 1-2 . . . 1-N including a first adjustable attenuator 20-1, 20-2 ... 20-N such as, for example, a PIN diode; wavepath 2-1, 2-2 . . . 2-N including a second adjustable attenuator 21-1, 21-2 . . . 21-N, and an adjustable delay means 22-1, 22-2 . . . 22-N; and means 23-1, 23-2 . . . 23-N for combining the signals in the two wavepaths. The combined signal in each of the first N-1 stages is coupled to the next stage in the equalizer. The combined signal from the last stage, E N (jω), is the equalizer output signal.
It should be noted that the first stage differs from the other N-1 stages in that the signal combiner 23-1 forms a difference signal whereas combiners 23-2 . .. 23-N form sum signals. The reason for this difference will become apparent in the discussion that follows.
With an input signal R(jω), the output signal E 1 (jω) of the first equalizer stage is the difference in the signals in the two paths 1-1 and 2-1 given by
E.sub.1 (jω)=b.sub.1 R(jω)-a.sub.1 e.sup.-jωT.sbsp.1 R(jω) (2)
where a 1 and b 1 are the attenuator gain factors for the respective wavepaths.
Substituting from equation (1) for R(jω), one obtains
E.sub.1 (jω)=ab.sub.1 (1-K.sup.-jωT)(1+be.sup.-jωτ)T(jω), (3)
where
K=a.sub.1 /b.sub.1
and
T=T.sub.1.
Expanding (3) yields
E.sub.1 (jω)=ab.sub.1 (1+be.sup.-jωτ -Ke.sup.-jωT -Kbe.sup.-jω(T+τ))T(jω) (4)
Making K=b and T=τ, equation (4) reduces to
E.sub.1 (jω)=ab.sub.1 (1-K.sup.2 e.sup.-jω2T)T(jω) (5)
This simplification is made possible by using a differencing combiner in stage 1. Having introduced the minus sign in equation (5) by this means, the remaining combiners are summing combiners.
In a similar manner, the output from stage 2 can be written
E.sub.2 (jω)=(b.sub.2 +a.sub.2 e.sup.-jωT.sbsp.2)E.sub.1 (jω). (6)
Substituting from equation (5) and combining terms, E 2 (jω) reduces to
E.sub.2 (jω)=ab.sub.1 b.sub.2 (1-K.sup.4 e.sup.-jω4T)T(jω) (7)
where
K.sup.2 =b.sup.2 =a.sub.2 /b.sub.2
and
T.sub.2 =2T=2τ.
In general, one can write for the output of the N th stage
E.sub.N (jω)=aC[1-K.sup.(2.spsp.N.sup.) e.sup.-jω2.spsp.N.sup.T ]T(jω) (8)
provided
a.sub.i /b.sub.i =(a.sub.1 /b.sub.1).sup.2.spsp.(i-1) =K.sup.2.spsp.(i-1) =b.sup.2.spsp.(i-1) (9)
and
T.sub.i =2.sup.(i-1) T.sub.1 (10)
for
1≦i≧N,
where
C=b 1 b 2 . . . b N is frequency independent.
For a minimum phase fade, b=K<1, the term K 2 .spsp.N becomes very small and equation (8) reduces to
E.sub.N (jω)=aCT(jω). (11)
Since a and C are frequency independent parameters, the equalizer output signal, as given by equation (11), is simply a scaled (i.e., totally equalized) replica of the transmitted signal. This is the equivalent of a flat fade which can be compensated by the AGC system in the receiver.
For a nonminimum phase fade, b=K>1, the term K 2 .spsp.N is much greater than unity and equation (8) reduces to
E.sub.N (jω)=-aCK.sup.2.spsp.N e.sup.-jω2.spsp.N.sup.T T(jω) (12)
where aCK 2 .spsp.N is a frequency independent term and e -j ω2.spsp.N T is a linear phase term. Thus, for both the minimum and nonminimum phase cases, the equalizer eliminates the frequency selective nature of the transmission medium due to multipath transmission.
The number of stages included in the equalizer will depend on the system requirements. For example, let us assume a 40 dB, minimum phase selective fade. This may be generated when a=1.0 and b=0.99. The number of stages required is given by
K.sup.2.spsp.N <<1.
Assuming K 2 .spsp.N ≦0.1, and further noting that K=b=0.99, one obtains that
N≧7.84.
This implies a minimum of 8 stages.
The above example represents a worst case condition in the sense that the fade is assumed to be due exclusively to destructive interference of the two signal components when a=1 and b=0.99. However, a 40 dB fade is obtained for other values of medium parameters such as a=0.1 and b=0.9. For this condition, one obtains a 40 dB fade which is composed of a 20 dB flat fade and a selective fade of only 20 dB. For this condition, a 5 stage equalizer will yield the same degree of equalization as the 8 stages operating on a 40 dB selective fade. In an article entitled "A New Selective Fading Model: Application to Propagation Data," by W. D. Rummler, published in the May-June 1979 issue of the The Bell System Technical Journal, it is shown that on the average most fades include components of both flat and selective fades. Since flat fades can be compensated by the AGC action of the receiver, a feed-forward equalizer with a relatively small number (i.e., 5 or 6) of stages will be adequate to provide substantial outage reduction. In the same Bell System Technical Journal article W. D. Rummler shows that the channel delay τ can be treated as a constant, set at 6.3 nsec. However, other values for τ are also possible.
As indicated hereinabove, signal fading is a dynamic phenomenon and, hence, means must be provided for sensing changing signal conditions and for readjusting the equalizer in response to these changes. FIG. 3, now to be considered, illustrates, in block diagram, one embodiment of an arrangement for adjusting the equalizer parameters so as to accommodate such changing signal conditions when the equalizer is used to compensate for multipath fades. Since the channel delay τ can be treated as a constant, the control algorithm can be simplified by fixing the delay elements 22-1, 22-2 . . . 22-N. As a result, the gain bump of the equalizer occurs at a fixed frequency. This means that the location (i.e., frequency) of the fade notch must be detected and then translated so that in all cases it is aligned with the equalizer gain bump frequency. Following this, the gain of the equalizer is adjusted such that it equals the magnitude of the selective fade portion of the fade. Accordingly, the equalizer 11 is located between an input frequency converter 43 and an output frequency converter 44 which serve to translate the signal fade notch frequency into coincidence with the equalizer bump frequency, and then back to within the IF band. Both converters receive a signal from a common voltage controlled local oscillator 45 whose output frequency is determined by a frequency error signal derived from a controller 50.
If the fade notch is not exactly aligned with the equalizer gain bump, the equalized spectrum will display an "S" shaped amplitude response. To detect this, the spectrum at the output of the equalizer is examined at frequencies surrounding the equalizer bump frequency f e . This is done by the two bandpass filters 39 and 40 which are tuned to frequencies f e+ and f e- , respectively, where f e- is a frequency below f e , and f e+ is a frequency above f e . The filter outputs are coupled to the controller which develops the appropriate compensating error signal for changing the oscillator frequency.
The location of the fade notch is determined by sampling the input signal at three frequencies, f 1 , f 2 and f 3 , within the band of interest, where f 2 is at band center and f 1 and f 3 are advantageously as close to the band edges as possible. Sampling is accomplished by feeding a portion of the input signal to each of three bandpass filters 32, 33 and 34 tuned, respectively, to f 1 , f 2 and f 3 . The three filter outputs are coupled to controller 50.
A second determination to be made is whether or not there is a minimum or nonminimum phase fade. This information is required by the controller in order to set the relative gain factors {a i } and {b i } of the equalizer stages. During a minimum phase fade, {a i } is advantageously set equal to unity, with {b i } adjusted to values less than one. For a nonminimum phase fade, {b i } is advantageously set equal to unity with {a i } made less than one. The information required to make this determination is obtained by sampling the signal at the input to the equalizer. The determination is made in a phase analyzer 51, which communicates the results of the determination to controller 50.
Finally, the three sampled frequencies f 1 , f 2 and f 3 are compared at the output of the output converter and the information thus derived is used to update the gain coefficients {a i } and {b i }. The output signal is sampled by bandpass filters 36, 37 and 38, and the sampled signals, thus obtained, are coupled to the controller.
In the discussion that follows, various illustrative circuits for providing the above-indicated control functions will be described. These circuits, collectively, comprise what has been referred to as the controller.
1. Fade Notch Detector and Oscillator Control Voltage Generator.
FIG. 4 shows, in block diagram, the portion of the controller 50 concerned with determining the fade notch frequency, f n , and adjusting the frequency of the local oscillator 45 so as to shift the fade notch into frequency coincidence with the equalizer bump frequency, f e .
As indicated hereinabove, to determine the fade notch frequency, the spectral power of the input signal is measured at three points. It can be shown that, based upon these measurements, the fade notch frequency can be approximated by ##EQU1## where f c is the frequency at band center;
and
A 1 2 , A 2 2 and A 3 2 are proportional to the power in the spectral samples centered at frequencies f 1 =f c -Δf, f 2 =f c , and f 3 =f c +Δf, respectively.
It is the function of the fade notch detector and oscillator control voltage generator to generate a control voltage that will produce frequency changes in oscillator 45 that are proportional to f n . Accordingly, the outputs from bandpass filters 32, 33 and 34 are coupled, respectively, to power detectors 72, 71 and 70 whose outputs are A 1 2 , A 2 2 and A 3 2 . Signals A 1 2 and A 3 2 are combined in differential amplifier 75 to produce signal A 1 2 -A 3 2 . Signal A 2 2 is amplified and inverted in amplifier 73 to produce signal -2A 2 2 , which is then combined with signals A 1 2 and A 3 2 in summing network 74 to produce signal A 1 2 +A 3 2 -2A 2 2 . The output of amplifier 75 is then divided in divider 76 by the output from summing network 74 to produce signal component A given by ##EQU2##
Signal component A is then multiplied in multiplier 77 by a voltage v.sub.Δf/2 that is proportional to Δf/2, and the resulting product added, in a summing network 78, to a second voltage v c that is proportional to f c . The resulting signal, v f , at the output of summing network 78 is then
v.sub.f =v.sub.c +Av.sub.Δf/2 (15)
where
v f is proportional to f n , as given by equation (13).
In the initial adjustment of oscillator 45, a voltage v.sub.(f.sbsb.e -f .sbsb.c.sub.) is applied to the oscillator such that the local oscillator frequency, f o , applied to the frequency converters 43 and 44 is
f.sub.o =f.sub.e -f.sub.c, (16)
where
f e is the equalizer bump frequency;
and
f c is the frequency at band center.
The function of the oscillator control voltage is to shift that frequency an amount f c -f n , so that the fade notch, rather than band center, is in frequency coincidence with the equalizer bump frequency. Accordingly, an incremental voltage Δv proportonal to f c -f n is required. (For purposes of this discussion, it is assumed that the oscillator output frequency is proportional to the control voltage over the range of interest.) This control voltage is obtained by multiplying v f by -1 in a multiplier 79, and adding voltage v c to the result in summing network 80. The resulting signal Δv is then given by
Δv=v.sub.c -v.sub.f, (17)
which is proportional to f c -f n as required.
In addition to this primary frequency control, there is a second oscillator control contribution made by sensing the spectral power at two frequencies f e+ and f e- about the equalizer bump frequency f e . Thus, in FIG. 4, the outputs from bandpass filters 39 and 40 are coupled to a pair of power detectors 81 and 82. The outputs P e+ and P e- from the latter are coupled, in turn, to an integrator 83 which generates a signal that is proportional to the difference in the signal power, integrated over a period of time. This integrated signal is applied to summing network 80 and serves as a vernier adjustment of the oscillator control voltage Δv.
2. Phase Analyzer
The relative adjustment of the gain factors a i and b i where i=1, 2, . . . , N in the respective equalizer stages is determined, in the first instance, by the phase characteristic of the fade. If the fade is a minimum phase fade, a i is made equal to unity and b i is made less than unity for all i. Conversely, for the nonminimum phase fade, b i is made equal to unity and a i is made less than unity for all i. Accordingly, means, in the form of a phase analyzer 51, are provided for examining the signal and making the necessary determination. In this regard, it can be shown that the delay responses of minimum and nonminimum phase fades vary in opposite directions as a function of frequency. For example, consider a fade having the amplitude response given by curve 84 in FIG. 5. If it is a minimum phase fade, the delay response is a maximum at the notch frequency, decreasing symmetrically as a function of frequency, as shown by curve 85. If, on the other hand, it is a nonminimum phase fade, the delay response is a minimum at the notch frequency, increasing as a function of frequency, as illustrated by curve 86. Thus, if the delay τ(f n ) at the fade notch frequency f n is compared with the delay τ(f n ') at a frequency f n ', symmetry located on the other side of the band center frequency, f.sub. c, the nature of the fade can be determined. That is, if
τ(f.sub.n)>τ(f.sub.n ')
it is a minimum phase fade, whereas if
τ(f.sub.n)<τ(f.sub.n ')
it is a nonminimum phase fade.
Thus, to determine the delays at frequencies f n and f n ', the phase analyzer comprises two delay sensors 105 and 106, as illustrated in FIG. 6. Noting that the delay is equal to the derivative of the phase angle with respect to frequency, delay sensor 105 evaluates the phase angle at the fade notch frequency f n and at a frequency f n +δf, where δf is relatively small, and then takes their difference to obtain a measure of the delay. It then does the same thing at f n ' and compares the two delays.
To determine φ(f n ), a component of the signal R(jω) is multiplied, in a mixer 91 located in delay sensor 105, by a signal cos 2πf n t derived from a local oscillator 92. It will be noted that the fade notch frequency is shifted to coincide with the bump frequency f e of the equalizer. Hence, oscillator 92 is simply tuned to f e . Signal R(jω) is also multiplied in a mixer 93 by a signal sin 2πf n t, obtained by passing the signal from oscillator 92 through a 90 degree phase shifter 89. The multiplier outputs are passed through lowpass filters (LPF) 94 and 95 (i.e., with cut-off frequency at 1 Hz) and then divided in divider 96 to form a signal proportional to tan φ(f n ). The latter is then coupled to a network 97 whose output is proportional to the arctangent of its output signal.
This process is also followed at a frequency f n ±δf, to produce at the output of a second network 98 a second signal proportional to φ(f n ±δf. The signals from the two networks 97 and 98 are coupled to differential amplifier 99 to form the difference signal φ(f n )-φ(f n +δf) which is proportional to the delay τ(f n ) at f n .
An identical procedure is followed at frequencies f n ' and f n '±δf in delay sensor 106. While the frequency of the notch is known by virtue of its coincidence with the equalizer frequency f e , the frequency f n ' is a variable. Accordingly, the oscillator control signals V.sub.(fe-fc), ΔV, Vc, generated in the controller are used to control the frequencies of a second pair of oscillators 100 and 101. Oscillator 101 has an additional vernier control voltage V.sub.δf proportional to δf. In all other respects, the operation of the second delay sensor 106 is as described hereinabove. The output signal τ(f n '), which is proportional to the delay at frequency f n ' is coupled along with the output signal τ(f n ) from sensor 105 to a differential amplifier 107 which forms a difference signal at its output. If the output signal is positive, i.e., τ(f n )>τ(f n '), the fade is a minimum phase fade, and a signal P equal to logic level "1" is produced at the output of a zero level comparator 108. If, on the other hand, the difference signal is negative, the fade is a nonminimum phase fade and a logic level "0" signal is produced.
3. Equalizer Gain Adjustment
The gain adjustments, a i and b i , in each of the equalizer stages are made by sampling both the equalizer input signal and the equalizer output signal at three frequencies across the band of interest. The reasons for sampling the input signal are (1) to determine whether or not a multipath, frequency selective fade has occurred, and (2) to determine what side of band center the fade notch is located. The output signal is sampled so as to determine the proper gain settings.
FIG. 7, now to be considered, shows that portion of the controller 50 relating to the equalizer gain adjustments. At the input end of converter 43, the input signal is sampled at three frequencies within the band of interest by means of bandpass filters 32, 33 and 34 whose center frequencies are f c -Δf, f c and f c +Δf, where f c is band center, and f c ±Δf are close to the band edges. The filter outputs are coupled to power detectors 110, 111 and 112 whose outputs are A 1 2 , a 2 2 and A 3 2 .
To determine whether or not a multipath fade has occurred, difference signals A 2 2 -A 3 2 and A 1 2 -A 2 2 are formed in differential amplifiers 113 and 114, and these differences compared to a specified threshold signal V T in magnitude comparators 115 and 116.
The significance of the difference signals can be appreciated by referring to FIGS. 8 and 9 which show the amplitude variations across the signal band for two different fade conditions. If, as illustrated by curve 131 in FIG. 8 or curve 135 in FIG. 9, the fade notch falls above f c (i.e., between f c and f c +Δf, or above f c +Δf), A 1 2 will typically be much larger than A 2 2 so that the magnitude of A 1 2 -A 2 2 will exceed the threshold level V T . If the fade notch falls below f c (i.e., between f c and f c -Δf, or below f c -Δf) as illustrated by curve 132 in FIG. 9, the magnitude of A 3 2 -A 2 2 will exceed V T . Finally, if the fade notch falls near f c , the magnitudes of both difference signals will exceed V T . In all cases, this indicates a multipath fade. Accordingly, all outputs from comparators 115 and 116 are coupled to an OR gate 117 whose output M is level "1" if either of the three above-noted conditions prevails.
If, on the other hand, the amplitude variations across the band are such that the difference signals do not exceed the specified threshold V T , the output M from gate 117 is level "0", indicating the absence of a multipath fade, or a fade that is shallow enough to be ignored.
Having established the presence of a multipath fade, we next wish to locate its position relative to band center. To do this, a difference signal A 1 2 -A 3 2 is formed in differential amplifier 118 and this difference compared to a zero level reference in comparator 119. If A 1 2 is greater than A 3 2 , as in FIG. 8, a comparator output signal SL of level "1" is produced. If, on the other hand, A 1 2 <A 3 2 , as in FIG. 9, a comparator output signal SL of level "0" is produced.
At the equalizer output, the signal is again sampled at frequencies f c and f c ±Δf, by means of bandpass filters 36, 37 and 38, and the samples detected in power detectors 120, 121 and 122 to produce signals B 1 2 , B 2 2 and B 3 2 . The object here is to examine these three signal components and to determine whether the signal has been undercompensated or overcompensated. When properly adjusted, the equalizer output signal will be substantially flat across the band. If, however, the signal is undercompensated, it will have an amplitude distribution as indicated by curve 133 in FIG. 8 or curve 136 in FIG. 9. If it is overcompensated, it will have the shape given by curve 134 in FIG. 8, or curve 136 in FIG. 9. Accordingly, to determine the output signal state, the midband signal B 2 2 is compared with the edgeband signal, farthest from the fade notch. With the fade notch located above f c , B 2 2 is compared with B 1 2 . Thus, the difference between signals B 1 2 and B 2 2 is formed in a differential amplifier 123 and the resulting difference signal is compared to a zero level reference in a zero level comparator 125. If B 2 2 <B 1 2 , the comparator output signal Δ 1 is level "0", indicating undercompensation, in which case the gain factors, a i , of the variable attenuators are increased for the minimum phase case, whereas the gain factors, b i , are increased for the nonminimum phase case. If, on the other hand B 2 2 <B 1 2 , Δ 1 ="1", in which case a i is decreased for the minimum phase case, and b i decreased for the nonminimum phase case.
When the fade notch is below band center (SL="0"), as shown in FIG. 9, B 2 2 is compared with B 3 2 .Accordingly, a difference signal B 3 2 -B 2 2 is formed in difference amplifier 124, and this difference compared with zero level in a zero level comparator 126. Depending upon the sign of the difference, output signal Δ 2 will be either at level "0" or level "1", indicating the required gain adjustment. A summary of the possible states, and the indicated gain adjustments are given hereinbelow in Table I.
TABLE I______________________________________ Minimum Phase Nonminimum Phase Fade FadeSL Δ.sub.1 Δ.sub.2 a.sub.i b.sub.i a.sub.i b.sub.i______________________________________1 0 Increase 1 1 Increase1 1 Decrease 1 1 Decrease0 0 Decrease 1 1 Decrease0 1 Increase 1 1 Increase______________________________________
Having made the various measurements, and generated the several control signals M, SL, Δ 1 , Δ 2 and P, the actual adjustments of the equalizer parameters are under the control of a microprocessor, such as the BELLMAC 8 (BELLMAC is a registered trademark of Western Electric) microprocessor, or its equivalent. Recalling the earlier discussion, that all of the gain factors are related as given by equation (9), the algorithm for making the gain adjustments is relatively simple.
FIGS. 10 and 11 outline the above-described procedure for adjusting the equalizer gain parameters a i and b i . Having defined the number of stages N and the band center frequency f c , the system is initialized by setting a i =0, b i =1 for all i=1, 2, . . . , N and P=1. These are the gain settings when there is no multipath transmission and for which the equalizer is transparent. The microprocessor then reads the control signals M, SL, Δ 1 , Δ 2 , f n , and P whose meanings are summarized hereinbelow.
______________________________________Control Signal Summary______________________________________M = 1 indicates presence of frequency-selective, multipath fadeM = 0 indicates absence of multipath fadeSl = 0 indicates fade notch frequency is above band centerSL = 1 indicates fade notch frequency is below band centerΔ.sub.1 = 0 indicates equalized signal is undercompensated while SL = 1Δ.sub.1 = 1 indicates equalized signal is overcompensated while SL = 1Δ.sub.2 = 0 indicates equalized signal is overcompensated while SL = 0Δ.sub.2 = 1 indicates equalized signal is undercompensated while SL = 0p = 1 indicates minimum phase fadep = 0 indicates nonminimum phase fadef.sub.n fade notch frequency______________________________________
If M is not "1", there is no multipath fade and a i and b i are left in their previous states. b i is unity and a i is zero for all i. If, on the other hand, M=1, indicating the presence of a multipath fade, the location of the fade is examined by calculating f c -f n . If this value is greater than one-half the channel bandwidth, the fade is out of band. For this case, the nature of the fade (i.e., minimum or nonminimum phase) is irrelvant so that the P setting remains in its previous state. Depending upon the slope SL of the inband amplitude dispersion, and the degree of over or under compensation, as indicated by Δ 1 and Δ 2 , the gain factors a i and b i are incremented and/or decremented, depending upon the nature of the fade, as indicated by P.
If the fade notch f n falls within the band (i.e., f o -f n is less than one-half the channel bandwidth) the phase characteristic of the fade is examined. If, for example, P is determined to be "1", indicating a minimum phase fade, the b i settings are examined. It will be recalled that for P=1, b i is set to unity for all i=1, 2, . . . , N. Accordingly, if b 1 is not less than unity, no immediate readjustment of the gain settings is called for, and the operational flow is to reexamine the a i settings by rechecking the slope SL and degree of compensation, Δ 1 , Δ 2 .
If, however, it is found that b i is less than unity, all b i gain settings are transferred to a i , and b i is set equal to unity. The new settings are then outputted.
A similar set of adjustments are made for P=0 except, in this case, a i is set equal to unity and b i is appropriately adjusted.
FIG. 12 shows an alternative, transversal filter equivalent of the N-stage feed-forward equalizer of FIG. 2. This embodiment comprises a delay line 160 with 2 N taps, where the tap spacing is T. Each of the 2 N taps 161-1, 161-2 . . . 161-2 N+ is coupled to a summing network 162 where the 2 N signal components, thus obtained, are summed to produce the equalized output signal.
Referring to the fed-forward embodiment of FIG. 2, the equalizer transfer function H(jω) can be expressed as ##EQU3##
If, as before, we make
C=b.sub.1 b.sub.2 . . . b.sub.N, ##EQU4##
Equation (21), however, is also the transfer function of a 2 N tap transversal filter with tap spacing T, and tap weights C(-1) i K i for 0≦i≦2 N -1. Inasmuch as the equalizer embodiments of FIGS. 2 and 12 are equivalent, the control algorithm described hereinabove with respect to the feed-forward equalizer is equally applicable for controlling a transversal filter equalizer for minimizing linear distortion caused by multipath fading.
It should be noted that the transversal filter equalizer operates on a modulated carrier signal (either RF or IF), and not on a baseband (i.e., demodulated) signal, which is typically the manner in which conventional transversal filters are used. | The dispersive effects of frequency selective fading in a digital, FM, or AM radio system are reduced by means of an adaptive equalizer (11) comprising a cascade of feed-forward stages (1,2, . . . N), each of which includes: a first parallel wavepath (1-1, 1-2, . . . 1-N) including a first adjustable attenuator (20-1, 20-2, . . . 20-N); a second parallel wavepath (2-1, 2-2, . . . 2-N) including a second adjustable attenuator (21-1, 21-2, . . . 21-N) and delay means (22-1, 22-2, . . . 22-N); and means (23-1, 23-2, . . . 23-N) for combining the signals in said wavepaths and for coupling said combined signal to the next stage. By a suitable selection of parameters, according to two unique relationships, a transfer function can be realized which can compensate for amplitude and delay distortions caused by minimum and nonminimum phase fades. | 7 |
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to new and useful improvements in general purpose digital computing systems. More specifically, it relates to a neural network architecture which uses an intercommunication scheme within an array structure for a completely connected network model.
2. Background Information
The neural computing paradigm is characterized as a dynamic and highly parallel computationally intensive system typically consisting of input weight multiplications, product summation, neural state calculations, and complete connectivity among the neurons.
Most artificial neural systems (ANS) in commercial use are modeled on von Neumann computers. This allows the processing algorithms to be easily changed and different network structures implemented, but at a cost of slow execution rates for even the most modestly sized network. As a consequence, some parallel structures supporting neural networks have been developed in which the processing elements emulate the operation of neurons to the extent required by the system model and may deviate from present knowledge of actual neuron functioning to suit the application.
An example of the typical computational tasks required by a neural network processing element may be represented by a subset of the full Parallel Distributed Processing model described by D. E. Rumelhart, J. L. McClelland, and the PDP Research Group, Parallel Distributed Processing Vol. 1: Foundations, Cambridge, Mass., MIT Press, 1986. A network of such processing elements, or neurons, is described in J. J. Hopfield, "Neurons With Graded Response Have Collective Computational Properties Like Those of Two-State Neurons," Proceedings of the National Academy of Sciences 81, pp. 3088-3092, May 1984. This processing unit in illustrated in FIG. 1 and Table 1.
Referring to FIGS. 1, neural network processing unit, or neuron 40, typically includes processing tasks, including input function I i 44 and activity function Y i 42, and connectivity network 46, 48 which, in the worst case, connects each such neuron to every other neuron including itself.
Activity function Y i 42 may be a nonlinear function of the type referred to as a sigmoid function. Other examples of activity function Y i 42 include threshold functions, probabilistic functions, and so forth. A network of such nonlinear sigmoid processing elements 40 represents a dynamic system which can be simulated on a digital processor. From a mathematical perspective, nonlinear dynamic models of neurons can be digitally simulated by taking the derivative of the nonlinear equations governing the neurons functions with respect to time and then using numerical differentiation techniques to compute the function. This mathematical basis allows mapping the nonlinear continuous functions of neural networks onto digital representations. In discrete time steps, input function I i multiplies digital weight values W ij by digital signal values, Y j , on each neuron input and then form a sum of these product's digital values. The input to the activity function Y i is the output I i , and its output, in this case, is activity function Y i directly; alternatively, the output could be some function Y i .
The accuracy of the nonlinear digital simulation of a neural network depends upon the precision of the weights, neuron values, product, sum of product, and activity values, and the size of the time step utilized for simulation. The precision required for a particular simulation is problem dependent. The time step size can be treated as a multiplication factor incorporated into the activation function. The neurons in a network may all possess the same functions, but this is not required.
Neurons modeled on a neural processor may be simulated in a "direct" and/or a "virtual" implementation. In a direct method, each neuron has a physical processing element (PE) available which may operate simultaneously in parallel with the other neuron PE's active in the system. In a "virtual" implementation, multiple neurons are assigned to individual hardware processing elements (PE's), which requires that a PE's processing be shared across its "virtual" neurons. The performance of the network will be greater under the "direct" approach but most prior art artificial neural systems utilize the "virtual" neuron concept, due to architecture and technology limitations.
Two major problems in a "direct" implementation of neural networks are the interconnection network between neurons and the computational speed of a neuron function. First, in an artificial neural system with a large number of neurons (processing units, or PE's), the method of connecting the PE's becomes critical to performance as well as cost. In a physical implementation of such direct systems, complete connectivity is a requirement difficult if not impossible to achieve due to the very large number of interconnection lines required. Second, the neural processing load includes a massive number of parallel computations which must be done for the "weighting" of the input signals to each neuron.
The relatively large size of the neural processing load can be illustrated with respect to a 64×64 element Hopfield network (supra), completely connected with symmetrical weights. Such a network has 64×64=4,096 neurons which, for a fully interconnected network, has 4096×4096 or approximately 16×10 6 weight values. A 128×128 element Hopfield network has 128×128=16,384 neurons with 256×10 6 weights. A sum of the weights times neuron input values across all neurons provides the input to each neuron's activation function, such as the sigmoid activation function previously described. Each computation contributes to the overall processing load which must be completed for all neurons every updating cycle of the network.
One structure for implementing neural computers is a ring systolic array. A systolic array is a network of processors which rhythmically compute and pass data through a system. One example of a systolic array for implementing a neural computer is the pipelined array architecture described by S. Y. Kung and J. N. Hwang, "A Unified Systolic Architecture for Artificial Neural Networks," Journal of Parallel and Distributed Computing 6, pp. 358-387, 1989, and illustrated in FIG. 2 and Table 2. In this structure each PE 50, 52, . . . , 54 is treated as a neuron, labeled Y i . Each neuron contains the weight storage 51, 53, . . . , 55 for that neuron with the weights stored in a circular shifted order which corresponds to the j th neuron values as they are linearly shifted from PE to PE. Assuming the initial neuron values and weights have been preloaded into PEs 50, 52, . . . , 54 from a host, the network update cycle computes the I i (steps 1 through 7) and Y i (step 8) values, as shown in Table 2. In this fashion a neural network can be modeled on a systolic array.
The ring systolic array architecture (FIG. 2 and Table 2) has the following performance characteristics assuming overlapped operations:
SYSTOLIC RING period=Nδ.sub.M +δ.sub.A +δ.sub.bus +δ.sub.S ( 1)
where the following delay variables are used, representing the delay through each named element:
δ M =Multiplier delay.
δ A =Communicating Adder: 2-1 add stage delay.
δ X =Sigmoid generator delay.
δ BUS =Communicating Adder: communications bypass stage delay.
and N represents the total number of neurons.
It is an object of this invention to provide an improved array processor apparatus and method.
It is a further object of this invention to provide an improved neural system architecture and method.
It is a further object of this invention to provide an artificial neural system which provides improved direct modeling of large neural networks.
It is a further object of this invention to provide an improved interconnection network for simplifying the physical complexity of a neural array characterized by total connectivity.
It is a further object of this invention to provide an improved neural array architecture and method adapted for efficient distribution over a plurality of interconnected semi-conductor chips.
SUMMARY OF THE INVENTION
In accordance with the apparatus of the invention, an array processor comprises a plurality of input function elements, with each input function element selectively allocated to a set of neurons, and each neuron including means for generating a neuron value from a selected set of input function elements and for communicating said neuron value back to said selected set of input function elements.
In accordance with the apparatus and method of this invention, the total connectivity of each neuron to all neurons, including itself, is accomplished by an orthogonal relationship of neurons: that is, a given multiplier element operates during a first cycle as a row element within an input function to a column neuron, and during a second cycle as a column element within an input function to a row neuron.
In accordance with the method of the invention, an array processor comprising orthogonal sets of neurons and a plurality of input function elements, is operated according to the method comprising the steps of (1) operating a first neuron upon a first subset of said input functions to generate and load back into said first subset a neuron value, and (2) allocating each of said first subset of input function elements to one of a set of orthogonal neurons.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the invention will be more fully appreciated with reference to the accompanying Figures, in which:
FIG. 1 is a schematic representation of a typical neuron function.
FIG. 2 is a schematic representation of a prior art ring systolic array.
FIG. 3 is a schematic representation of a four neuron array illustrating total connectivity.
FIGS. 4A and 4B are symbolic and schematic representations of a communicating adder designed according to the invention.
FIGS. 5A and 5B are symbolic and schematic representations of multiplier designed according to the invention.
FIGS. 6A and 6B are symbolic and schematic representations of an activity function generator (herein, a sigmoid generator) designed according to the invention.
FIG. 7 is a schematic representation illustrating the interconnection of communicating adders, multipliers, and sigmoid generators to form a four neuron matrix.
FIGS. 8 thru 15 are a schematic representation showing the states of selected elements of the four neuron matrix of FIG. 7 through two neuron update cycles of operation.
FIG. 16 is a timing diagram for the bit serial embodiment of the invention.
FIG. 17 is a schematic representation of a physical layout structure for the packaging and wiring of a neuron matrix.
FIG. 18, 18A, and 18B are a schematic representation of a multiplier quadrant of a sixteen neuron matrix.
FIGS. 19, 19A, and 19B are a schematic representation of a physical layout structure for the packaging and wiring of a neuron matrix having multiplier array chips and neuron activation function chips.
FIGS. 20A and 20B are symbolic and schematic representations of an embodiment of the neuron activation function chips of the neuron matrix of FIG. 19.
FIG. 21 is a schematic block diagram illustrating the neural array network of the invention within a host environment.
FIG. 22 is a schematic representation of the row scalability embodiment of the invention showing the use of an iterative adder.
FIG. 23 is a schematic block diagram of the iterative adder of FIG. 22.
FIG. 24 is a schematic block diagram of the dual path adder embodiment of the invention.
FIGS. 25A and 25B are schematic block diagrams of the multiplier function, illustrating another aspect of the dual path adder embodiment of the invention.
FIGS. 26A and 26B are schematic block diagrams of the sigmoid, or activation, function for the row scalability embodiment of FIG. 22.
FIG. 27 is a schematic block diagram of an example of a multiplier chip for row scalability.
FIG. 28 is a schematic representation illustrating an example of a multiplier array chip for a row scalability embodiment of the invention, using a two row building block for an N=1024 neuron system.
FIG. 29 is a schematic representation of a three dimensional embodiment of the invention for a four neuron SNAP.
FIG. 30 is a schematic block diagram of the three dimensional, four neuron SNAP embodiment of FIG. 29.
FIG. 31 is a schematic representation of neuron input values through two update cycles of operation of the three dimensional, four neuron SNAP embodiment of FIGS. 29 and 30.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
This invention relates to a neural processor including orthogonal sets of neuron elements and provision for transporting neuron values between elements. A neuron comprises (1) an input function, typically a set of input function elements, or multiplier elements each responsive to an input value and a weight value to provide a weighted output, (2) a combination or reduction function, typically an adder tree for combining the weighted outputs from the multiplier elements into a single value, and (3) an activation function responsive to the single value for generating the neuron output. In the worst case, of total connectivity, each of the neurons in an N×N array of neurons is connected to communicate its neuron output as an input value to all neurons, including itself--and thus would have a set of N multiplier elements at its input function. In accordance with a preferred embodiment of this invention, the combination function includes a reverse communication path for communicating the neuron output back just to its own input function. Alternatively, a separate communication path may be provided. The total connectivity of each neuron to all neurons, including itself, is accomplished by the orthogonal relationship of neurons: that is, a given multiplier element operates during a first cycle as a row element within an input function to a column neuron, and during a second cycle as a column element within an input function to a row neuron.
The four basic operations generally implemented by a neural computer simulating a completely connected N neuron network are:
1. N 2 Multiplications
2. N Product Summations
3. N Activation Functions
4. N×N Communications
As will be hereafter described, in accordance with a preferred embodiment of the invention, the architecture of a scalable neural array processor (also referred to as SNAP) provides the N 2 multiplications by utilizing N 2 multipliers, the N product summations by tree structures, the N activation functions by utilizing separate activation function modules, and the N×N communications by a reverse path mechanism included within adder tree structures.
In connection with preferred embodiments of the invention hereinafter described, the function implemented by the neural processor is: ##EQU1## Where: N is the number of neurons, F(x) is the neuron activation function which in a preferred embodiment is set equal to a sigmoid activation function whose form can be: ##EQU2## And Where: The subscripts on the weights W such as W 13 represent the weight of the connection between neurons, in this example from Neuron 3 to Neuron 1.
In the embodiments of the invention to be hereafter described, it is assumed that the weights are fixed for the duration of the network execution. However, as these weights are loadable from a host computer, learning algorithms may be implemented at the host and weight updating provided. Further, referring to FIG. 21, in the preferred embodiments of the invention to be hereafter described, host computer 30 also initializes network 32 architectures by (1) loading (a) the number of neurons in the network to be simulated by the architecture, (b) all the connection weights, (c) the initial neuron values, and (d) the number of network update cycles to be run, (2) starting the model into execution, and (3) reading the neuron values at the completion of network execution.
Hereafter, in assessing and comparing the performance of various neural processing architectures, only performance during execution is considered, and not the initialization time and the host processing time.
In accordance with a preferred embodiment of the invention, a multiplier and adder tree array structure to be described provides a means for transporting neuron values between the neuron elements. The interpretation of equation 2 for this embodiment of SNAP is based on noting that for each neuron i there is a weight multiplication with the same Y j input but with different weights. This is seen by expanding equation 2 for each neuron value and comparing the equations for the multiple neuron outputs. For example, the N neuron outputs formed from equation 2 are as follows:
Y.sub.1 =F(W.sub.11 Y.sub.1 +W.sub.12 Y.sub.2 +. . . +W.sub.1N Y.sub.N)
Y.sub.2 =F(W.sub.21 Y.sub.1 +W.sub.22 Y.sub.2 +. . . +W.sub.2N Y.sub.N)
Y.sub.N =F(W.sub.N1 Y.sub.1 +W.sub.N2 Y.sub.2 +. . . +W.sub.NN Y.sub.N)
Referring to FIG. 3, as an example, a four (N=4) neuron array with N 2 interconnections is shown, illustrating the principle of total connectivity (and the almost impossibility of physically realizing an N neuron matrix as N becomes much larger.) Herein, neuron 60 comprises adder tree 62, multipliers 64, 66, 68, 70, and sigmoid generator 72. This neuron structure is replicated, forming three more neurons 90, 92, 94, in which sigmoid generators 74, 76, 78 are associated with adder trees 80, 82, 84, respectively, and multiplier circuits 91, 93, 95, 97, 61, 63, 65, 67, 71, 73, 75, 77, as shown. The output value Y2' from sigmoid generator 74 of neuron 90 is fed back (that is, interconnected by data paths 69) to the inputs to multipliers 66, 93, 63, and 73, which form the second row of a four by four multiplier matrix. The output value Y3' from sigmoid generator 76 of neuron 92 is fed back (interconnected by data paths 79) to the inputs to multipliers 68, 95, 65, and 75, which form the third row of the four by four multiplier matrix. While not shown, the outputs Y1' and Y4' of sigmoid generators 72 and 78 of neurons 60 and 94, respectively, are fed back (interconnected) to the inputs of multipliers 64, 91, 61, and 71 forming the first row of the multiplier matrix, and to multipliers 70, 97, 67, and 77 forming the fourth row of the matrix, respectively. Herein, the weights and neuron values are represented by some arbitrary number of bits on the data communication paths reflecting the precision of the value, for example a 16 or 32 bit representation, and these values can be produced and communicated in parallel or serial fashion.
Assuming the Y j inputs (such as Y1, Y2, Y3, and Y4) and their associated weights are separately available and there are N separate parallel multipliers (such as multipliers 64, 66, 68, 70) then for a given neuron "i" (such as neuron 60), N products can be formed in parallel (at the outputs of multipliers 64, 66, 68, 70) in one multiplier delay time. These N products are then added together using 2 to 1 adders arranged in a tree structure (such as adder tree 62) to form a final summation X which is passed to the F(X) unit (such as sigmoid generator 72) to produce the i th neuron output (such as Y1'). With N neurons (such as 60, 90, 92, 94) of this type, N neuron values (such as interconnected neuron values Y1', Y2', Y3', Y4') can be produced.
As the output of each neuron is interconnected to the input of all other neurons in the matrix, including itself, the N neurons 60, 90, 92, 94 of FIG. 3 require N 2 connections 69, 79, . . . , which, as N increases, is difficult if not impossible to physically realize.
In accordance with the present invention, in order to achieve the completely interconnected structure in SNAP, as required by equation 2 but without the difficulties presented by the interconnection scheme set forth in FIG. 3, a novel method of transporting the neuron values is provided. This is accomplished through the use in a matrix of orthogonal neurons (to be hereinafter described in connection with the four neuron SNAP of FIG. 7) of the SNAP adder tree of FIGS. 4A, 4B, the SNAP multiplier of FIGS. 5A, 5B, and the SNAP sigmoid generator of FIGS. 6A, 6B. Herein, a pair of neurons are orthogonal if they time share an input function element. Other interconnection networks can be utilized provided they have the attribute of reducing a plurality of inputs to one value, which value is communicated back to the inputs, as is described hereafter in the SNAP adder tree example of FIGS. 4A, 4B.
Referring to FIG. 4A, a symbolic representation of the adder tree 108 of the invention is provided, with the 2-1 adders designated by the letter A.
Referring to FIG. 4B, the more detailed representation of the adder tree 108 of the SNAP is shown. Three SNAP 2-1 adder elements 120, 122, 124 are shown in a 2 stage pipelined tree arrangement. Output stage 110 2-1 adder element 124 has Driver-1, DRVR1, block 126 on its output and two Driver-2, DRVR2, blocks 128, 130 bypassing adder 124, but in a reverse direction. Drivers 126, 128, 130 are responsive to enable/disable signals (generated by state control 34 of FIG. 21) which, when in the disable state, keeps the driver output in a high impedance state and when in the enable state turns the driver into a non-inverting buffer. When DRVR1 block 126 is enabled DRVR2 blocks 128, 130 are disabled and visa versa. This structure is replicated at the input stage, with both input adders 116, 118 having outputs 112, 114, respectively, forming the inputs to output stage 110. In this manner the adder tree can provide the summation function in one direction, DRVR1's enabled - DRVR2's disabled, while essentially acting as a communication path in the reverse direction, DRVR1's disabled - DRVR2's enabled. Alternatively, a separate reverse communication path can be utilized, as hereinafter described in connection with FIG. 24. Also, pipeline latches (not shown) would generally be provided on the inputs to the adders.
An adder tree (such as 108) using 2 to 1 adders (such as adders 120, 122, 124) will require Log 2 N adder stages. It should be noted that SNAP's communicating adder 108 represents its logical function since, for example, depending upon technology, the DRVR1 126 function could be incorporated in the gate devices required by each of adders 110, 116, 118 thereby adding no additional delay to the add function. Alternatively, and in the general sense, the forward summation and reverse communication path may be implemented with 2 to 1, 3 to 1, . . . , N to 1 adders, or combinations thereof. Also, in the general sense, the summation function may be any function (Boolean or arithmetic, or combination thereof) which converges a plurality of inputs to an output value.
Referring to FIGS. 5A and 5B, SNAP's multiplier 160 is designed to work with communicating adder 108. Storage is provided in register 162 for the neuron values and in register 164 for their associated weights. The Equation (2) Y j and W ij values, or operands, are initialized from the HOST computer into registers 162, 164, respectively, and are inputs to multiplier 166. The Y j values in register 162 after initialization are received from the communicating adder along path 170 when it is in communicating mode; that is, DRVR1s 126, 168, . . . , disabled and DRVR2s 128, 130, . . . , enabled. While block 166 is here shown as a multiplier, the invention is not so restricted, and alternative functions may therein be provided for generating an output function to driver 168 within the scope of the invention.
Referring to FIGS. 6A and 6B, SNAP sigmoid generator 180 also works with communicating adder 108 by first calculating in generator block 182 and storing in register 184 the neuron value Y i from the summation of weighted inputs, DRVR1s enabled - DRVR2s disabled and second by passing the generated neuron Y value in reverse fashion, DRVR1s disabled - DRVR2s enabled, back through adder 108 to be received by multiplier 160. As previously noted, functions other than a sigmoid function may be implemented in activation function block 180 without departing from the spirit of the invention.
Referring now to FIG. 7, a four neuron SNAP matrix in accordance with a preferred embodiment of the invention is set forth. In the embodiment of FIG. 7, the arrangement of FIG. 3 is modified by a structure in addition to those of FIGS. 4 through 6 in order to make use of the communication path of this embodiment of the invention through the adder tree. This additional structure is another set of N communicating adder trees (one being represented by adder tree 232) with sigmoid generators 220, 222, 224, 226 placed orthogonal to a first set 210, 212, 214, 216. FIG. 7 shows these additional N structures in a 4 neuron SNAP. The added horizontal structures, or row sections, including communicating adder trees 232, etc., and activation, or sigmoid, generators 220, 222, 224, 226 are exactly the same as the vertical structures previously described in connection with FIGS. 4, 5, and 6, with the exception that there are new driver enable/disable signals (not shown) required for the row sections. In FIGS. 7 thru 15, for simplicity in explanation, the vertical column adder trees (such as adder 230) and associated sigmoid generator (such as sigmoid generator 210) are labeled with a lower case v, for vertical, while the horizontal adder trees (such as 232) and their associated sigmoid generators (such as 224) are labeled with a lower case h, for horizontal. Similarly, references to drivers DRVR1 and DRVR2 associated with vertical adder trees and corresponding sigmoid generators (even though not specifically shown in FIGS. 7-15) will be identified with a lower case v. Similarly, drivers associated with horizontal trees and generators are identified by lower case h. Herein, each input function block, such as multiplier 246, is associated with orthogonal neurons: that is, allocated in a time shared manner to one vertical neuron 230 and one horizontal neuron 232, in a manner now to be described.
Referring now to FIGS. 8 thru 15, a description of several states of the four neuron SNAP of FIG. 7 are presented for two cycles of update operation in accordance with a preferred embodiment of the method of the invention. In each of FIGS. 8 thru 15, asterisks are used to illustrate the function being performed in the respective process steps or states. The matrices of FIGS. 8 through 15 correspond to FIG. 7, simplified by not including the data path lines, with horizontal adder tree 232 (and, similarly, adder trees 286, 288 and 290) represented by horizontal bars, and vertical adder tree 230 (and, similarly, adder trees 280, 282 and 284) represented by vertical bars. For clarity of explanation, in FIGS. 9 through 15, selected active elements are identified by reference numerals.
The matrix of FIGS. 7 and 8 is initialized, herein, by the host loading the weights (FIGS. 1 and 5B) and first neuron values Y1, Y2, Y3, Y4 into the multiplier registers 162, 164 (FIG. 5B) of each column. Thereafter, the SNAP structure of the invention operates as follows.
Step 1: MULTIPLY. Referring to FIG. 8, neuron values Y i are multiplied by weights W ij in parallel in multipliers 240, 242, . . . , 250, . . . , 278.
Step 2: VERTICAL FORWARD. Referring to FIG. 9, vertical column adder trees 230, 280, 282, 284 are operated with DRVR1vs enabled, and DRVR2vs, DRVR1hs and DRVR2hs disabled to combine, herein provide the summation, of the weighted neuron values. (In this description of FIGS. 7 thru 15, the "s", such as is used in "DRVR1vs", designates the plural.)
Step 3: GENERATE VERTICAL. Referring to FIG. 10, vertical activation functions, herein sigmoid generators 210, 212, 214, 216 produce the vertical neuron values, Y i vs: Y1', Y2' Y3', Y4'.
Step 4: VERTICAL REVERSE. Referring to FIG. 11, vertical adder trees 230, 280, 282, 284 are operated with DRVR2vs enabled, and DRVR1vs, DRVR1hs, and DRVR2hs disabled to communicate the Y i vs back to the input registers 162 (FIG. 5B) of multipliers 240, 242, . . . , 250, . . . , 278.
This completes the first update cycle, such that the input values Y1, Y2, Y3, Y4 initialized down the columns have been modified and positioned across the rows of the matrix as values Y1', Y2', YE', Y4', respectively.
Step 5: MULTIPLY VERTICAL. Referring to FIG. 12 in connection with FIG. 5B, vertical neuron values Y i v (in registers 162) are multiplied (multiplier 166) by weights W ij (in registers 164).
Step 6: HORIZONTAL FORWARD. Referring to FIG. 13 in connection with FIG. 4B, horizontal adder trees 232, 286, 288, 290 are operated with DRVR1hs enabled, and DRVR2hs, DRVR1vs, and DRVR2vs disabled to produce the summation 171 of the weighted neuron values.
Step 7: GENERATE HORIZONTAL. Referring to FIG. 14 in connection with FIG. 6B, horizontal sigmoid generators 220, 222, 224, 226 produce Y i hs Y1", Y2", Y3" Y4".
Step 8: HORIZONTAL REVERSE. Referring to FIG. 15, horizontal adder trees 232, 286, 288, 290 are operated with DRVR2hs enabled, and DRVR1hs, DRVR1vs, and DRVR2vs disabled to communicate the Y i hs Y1", Y2", Y3" Y4" back to the input registers of multipliers 240, 242, . . . , 250, . . . , 278.
This completes the second update cycle, such that the original input values Y1, Y2, Y3, Y4, now twice modified, appear as Y1", Y2", Y3", Y4" positioned down the columns.
Steps 1 through 8 are repeated until a host specified number of iterations have been completed.
To evaluate the performance of the SNAP architecture with respect to the objects of the invention the following delay variables are used, representing the delay through each named element:
δ M =Multiplier delay.
δ A =Communicating Adder: 2-1 add stage delay.
δ S =Sigmoid generator delay.
δ B =Communicating Adder: communications bypass stage delay.
And the following general assumptions noted:
1. The system defined clock period is C, with all delays specified as multiples of C.
2. In this embodiment of SNAP, 2 to 1 adders are used in the summation tree function with log 2 N additional stages, where N is the total number of neurons being simulated and is equal to the number of neuron inputs.
The performance of the SNAP architecture may be represented by the time required for generating the neuron outputs. Since SNAP, as with the ring systolic array, is based on recursive equation 2, the computation of Y i (t+1) cannot begin before the previous Y i (t) values have been calculated and received at the input. In this example, the multiply and sigmoid functions are not pipelined, but require their inputs to be held constant for the whole multiplier or sigmoid delay. (Of course, they could be pipelined.) For the safeness of the structure and performance reasons, it is desired that the values for a computation are present in the inputs of the various functional units when required and that the input logic and weight access operate in parallel with the multiply operations, ie. in pipelined mode. In order to achieve safeness with no additional delays, each operation must follow in sequence at the completion of the previous operation, as follows:
1. Multiply,
2. Add tree,
3. Sigmoid generator, and
4. Communication tree.
This sequence of events requires a simple control mechanism such as the use of a counter whose output value is compared against delay values representing the listed events, namely: the multiplier delay, the log 2 N communicating adder tree - add mode delay, the sigmoid delay, and the log 2 N communicating adder tree - communications mode delay. When a delay match occurs the next event in sequence is started.
Assuming this control sequence is followed the period between neuron values is:
SNAP period=δ.sub.M +(log.sub.2 N)δ.sub.A +δ.sub.S +(log.sub.2 N)δ.sub.B
Assuming δ A =δ B =1C, a reasonable assumption, then SNAP's period is:
SNAP period=δ.sub.M +2(log.sub.2 N)C+δ.sub.S
An assumption up to this point has been that the weights and neuron values are represented by some arbitrary number of bits reflecting the precision of the value, for example a 16 or 32 bit representation. The value representation choice can greatly limit the physical implementation of SNAP as each multiplier in the array must support the representation. N 2 32 bit multipliers, for example, would greatly limit the number of neurons, N, supported by the physical implementation. In line with this design issue, is the question of how much precision is required by the neural network problem being mapped onto the SNAP implementation. The amount of precision seems to be problem specific, consequently a desirable feature for the SNAP architecture would be to allow user specified precision as required by the application. Using a bit serial approach with programmable specified bit length solves not only the user selectable precision issue but also greatly eases the physical inplementation. Each multiplier's weight and Y j registers function as variable length shift registers where the bit length L of the operands is programmable from the host. The multipliers provide bit serial multiplication, with L or 2L bits of precision, injecting the result bits into the communicating adder, which is also of bit serial design. For examples of bit serial multiplier designs, see Lyon, R. F., "Two's Complement Pipeline Multipliers", IEEE Transactions on Communications, April 1976, pp. 418, 425, the teachings of which are incorporated herein by this reference. The sigmoid generator must either be of bit serial design or be able to handle variable length sum of product values.
Referring to FIG. 16, for the case where the multiplier provides L bits of precision, the sigmoid generator is not bit serialized, but rather processes a sum of product input of length L, the bit serial SNAP period is:
Bit Serial SNAP period=2(log.sub.2 N)C+2(L)C+δ.sub.S
Referring to FIG. 17, in accordance with an embodiment of the invention providing a physical layout structure having advantageous packaging and wiring characteristics for arrays of large N, the N×N array of multipliers is partitioned into four quadrants, each representing N/2×N/2 multipliers with adder trees, with sigmoid generators placed horizontally and vertically between the quadrants.
Referring to FIG. 18, for example, one of the four neuron SNAP multiplier quadrants of the array structure of FIG. 17 is shown. In FIG. 18, capital letter A indicates a 2 to 1 adder. These are arranged as horizontal and vertical adder trees, such as 300, 302, respectively, as described in connection with FIG. 4A. Multiplier cells M are as described in connection with FIG. 5A. Larger arrays utilize the same building blocks yielding a space and wiring efficient matrix. For the larger arrays the number of wire crossings for the adder tree data paths is not more than log 2 (N/2) in both horizontal and vertical wiring channels. Sigmoid generators 310 through 324 are provided on the rows, and 330 through 344 on the columns, of the matrix.
Referring now to FIG. 19, an example of a packaging scheme for the SNAP architecture of the invention will be described. Herein, two different types of chips are used, one being multiplier array M-CHIPs 400 through 436, of the form shown in FIG. 18, and the second being neuron activation function chips 440, 442, 444, 446, including input communicating adder trees 460, 462, 464, 466, respectively, for each SIG1v . . . SIG-Nv, and SIG1h . . . SIG-Nh, such as 450 through 456. In this example packaging scheme, to allow for expansion, SIG chip input communicating adder trees 460 through 466 are each modified slightly, as shown in FIGS. 20A and 20B.
Referring to FIG. 20B, additional drivers, DRVR3, such as 480, 482, have been added to adder stages 484, 486, allowing adder stages, such as 120, to be bypassed under control of state definition control 34 (FIG. 21) in a forward direction in a similar manner to the bypass of adders, such as adder 124, provided in the reverse direction by DRVR2s 128, 130. An adder stage is bypassed in the forward direction when that stage is not required by the system being built. In a smaller system, chips are connected and input adder stages are bypassed such that the chips used connect to the correct level in the adder tree. With the SIG chip example of FIG. 20 containing three adder stages 484, 486, 488, two different systems can be built, one with one M-CHIP per quadrant and the second with four M-CHIPs, such as 400, 402, 404, 406 per quadrant as shown in FIG. 19. Of course larger input trees can be designed into the SIG chip allowing much greater growth. This is not a particular chip I/0 problem since the connections to the adder tree may be bit serial. With this scheme the expansion must be done by a factor of four within each quadrant in order to keep a symmetric N/2×N/2 relationship within the quadrant. For examples see Table 3.
Referring to FIG. 21, host 30 is shown in two way communication with scalable neural array processor 32, which includes various drivers, such as DRVR1, DRVR2, DRVR3 all responsive to enable/disable state definition control 34 in accordance with the protocols herein described.
Referring to FIG. 22, a row scalability embodiment of the invention will be described. In this embodiment, provision is made for processing an N by N neural array matrix less than N rows at a time; in this example, two rows at a time. Thus, two rows 500, 502, each N multipliers 504, 506 long, have iterative adders 508, 510, . . . , 512 installed on the outputs of vertical communicating adder trees 514, 516, . . . , 518, respectively.
Referring to FIG. 23, iterative adder 512, for example, comprises adder 520 and storage register 522. Iterative adder 512 accumulates in register 522 partial summations from vertical communicating adder tree 518 as column 518 is cycled N/#Rows times until the final summation is formed and then supplied to Sigmoid generator 524. Similarly, iterative adders 508 and 510 accumulate the partial sums from adder trees 514, 516 respectively, two rows 500, 502 (#Rows) at a time, and provide the final summation to activation (Sigmoid) functions 526, 528, respectively. After these column summations are completed, N neuron values are generated by activation functions 524, 526, 528, . . . , and communicated back up adder trees 514, 516, . . . , 518 to horizontal adder trees 500, 502, as will be described hereafter in connection with FIGS. 24 through 26.
Referring to FIG. 24, vertical adder tree 518 (see FIG. 22) is shown in accordance with the dual path embodiment of the invention. Herein, for performance reasons and in contrast to adder tree 108 (FIG. 4B), separate reverse communication paths 530, 531, 532, 534, 536 are provided from sigmoid 524 register 570 (FIG. 26B) output Y N back to multipliers 504, 506, . . . (While four reverse communication paths 530 through 536 are shown in FIG. 24, only two would be required for the two-row at a time embodiment of FIG. 23.) Depending upon the size of tree 108, and the technology used, drivers DRVR2 538, 540 are used on the reverse communication paths 530 through 536 to handle the loading. While reverse communication paths 530, 532, 534, 536 are shown following adder tree paths 540 through 550, this is not necessary, as their destinations are input registers 564 (FIG. 25B) to multipliers, such as 504, 506.
Referring to FIGS. 25 and 26, multipliers 504, 506 and sigmoid generator 524 are modified by providing lines 560, 562 to allow for this separate reverse communication path.
Referring to FIG. 25B, multiplication function 504, for example, stores N/#Rows of neuron values and associated weights in Y value stack 564 and weight stack 566, respectively. Stacks 564, 566 store N/#Rows of neuron values in a first-in first-out arrangement. Similarly, referring to FIG. 26B, as each row 500, 502 must be cycled N/#Rows times, Sigmoid generator 524 (FIG. 26A) includes register 570 and thus is of pipelined design to allow for overlapped operations.
Referring to FIG. 27 in connection with FIG. 22, a row scalability embodiment of the invention is illustrated wherein two rows represent minimum building block for 2×128 multiplier array chip 601 with 2-7 stage dual path adders, one per row 500, 502, and 128 one stage adders 591 593, one per column 514, . . . , 518, used to create an N=1024 neuron system. Lines ROW-1(xxx)h 590 are the outputs of seven stage communicating adders 592 for first row 500, replicated at lines 594 and adders 596 for second row 502. Herein, column output partial sum lines PS1, PS2, PS3, . . . , PS128 are provided, each for connecting to iterative adders 508, 510, . . . , 512 in a sigmoid generator chip with the input tree bypassed. Expansion is done by adding rows to the system and connecting the sigmoid generator chips as shown in FIG. 28.
The performance of SNAP with row scalability is not symmetric as would be expected with a period associated with the column Y i production and a different period associated with the row Y i production. ##EQU3##
As rows are added the performance becomes more symmetric and with N columns×N rows, equals the performance of SNAP without row scalability, as previously discussed.
Referring to FIGS. 29 and 30, the SNAP orthogonal switching concept of the invention is extended from the two dimensional row/column switch in neuron definition to a three dimensional switch between planes of neurons. In the cube like structure 640 of FIG. 29, four planes 642, 644, 646, 648 each represent one of the neurons in a four neuron network. Add convergence is illustrated by four pyramid like structures 650, 652, 654, 656, one for each neuron, comprising 2 to 1 adder elements. Thus, sidel 642 represents a first neuron, including input elements 660, 662, 664, 666 initialized to values Y1, Y2, Y3, Y4, respectively. During a first cycle of operation, the first neuron value Y1' is generated and loaded back into input elements 660, 662, 664, 666. During a second cycle, the Y1' value from input element 660, the Y2' value from input element 670, and Y3' and Y4' values from corresponding input elements from side3 646 and side4 648 are fed to sigmoid generator 700 to produce value Y1". In FIGS. 30 and 31, the cube structure of FIG. 29 is unfolded to illustrate a four-neuron snap through two update cycles. The concept of orthogonality is preserved in this embodiment, inasmuch as each input element, such as element 660, is time shared between two neurons, in this case a first neuron comprising input elements 660, 662, 664, 666 and a second neuron comprising input elements 660, 670, . . .
By using the communicating adder tree, as herein described, or any similar interconnection structure, and the SNAP structure of the invention, the inherent limitations of the N 2 connections is greatly minimized allowing a regular structure for expandability while still keeping complete interconnectivity. Furthermore the performance impact of the required N 2 communications is log 2 N, which is a small impact as N increases.
In Table 4, a summary performance evaluation and comparison with alternate architectures is set forth, including hardware cost and performance comparison between the SNAP, BIT SERIAL SNAP, and SNAP ROW architectures of the invention, and the SYSTOLIC RING architecture of the prior art.
While preferred embodiments of the invention have been illustrated and described, it is to be understood that such does not limit the invention to the precise constructions herein disclosed, and the right is reversed to all changes and modifications coming within the scope of the invention as defined in the appended claims.
TABLE 1______________________________________NEURAL NETWORK COMPUTATION EXAMPLE______________________________________INPUT FUNCTION Ii ##STR1##ACTIVITY FUNCTION Yi(t) ##STR2##NETWORK FULL CONNECTIVITY - EACHCONNECTIVITY NEURON CONNECTS TO EVERY OTHER NEURON INCLUDING ITSELF.______________________________________
TABLE 2__________________________________________________________________________OPERATION SEQUENCE FOR RING SYSTOLIC ARRAYARCHITECTURE FOR NEURAL NETWORKSPE-1 PE-2 PE-N__________________________________________________________________________1 - Y1*W11 Y2*W22 . . . YN*WNN2 - ACC1 = Y1*W11 ACC2 = Y2*W22 . . . ACCN = YN*WNN3 - PE-1 ← Y2 PE-2 ← Y3 . . . PE-N ← Y14 - Y2*W12 Y3*W23 . . . Y1*WN15 - ACC1 = ACC1+Y2*W12 ACC2 = ACC2+Y3*W23 . . . ACCN = ACCN+Y1*WN16 - PE-1 ← Y3 PE-2 ← Y4 . . . PE-N ← Y2MULTIPLY, ACCUMULATE, AND SHIFT UNTIL N-1 ACCUMULATE OPERATIONSARE COMPLETED.7 - PE-1 ← Y1 PE-2 ← Y2 . . . PE-N ← YN8 - Y1' = F(ACC1) Y2' = F(ACC2) . . . YN' = F(ACCN)9 - CONTINUE WITH THE NEXT NETWORK UPDATE CYCLE.__________________________________________________________________________
TABLE 3__________________________________________________________________________EXPANSION OPTIONSMULTIPLIER CHIP CONTAINS 16 × 16 MULTIPLIERS SUPPORTING16 VERTICAL AND 16 HORIZONTAL SIGMOID ACTIVATION CHIPSSIG INPUT # MULTIPLIER CHIPS TOTAL # MULTIPLIERTREE STAGES PER QUADRANT CHIPS IN SYSTEM N__________________________________________________________________________1 1 4 322 4 16 644 16 64 1286 64 256 2568 256 1024 51210 1024 4096 1024__________________________________________________________________________
TABLE 4__________________________________________________________________________ARCHITECTURE COMPARISONS PERFORMANCE EXAMPLE δ.sub.A = δ.sub.bus = 1CNETWORK HARDWARE DELAY EQUATION N L = 32__________________________________________________________________________SYSTOLIC N-MULTIPLIERS Nδ.sub.M + δ.sub.A + δ.sub.S + δ.sub.bus 128 128δ.sub.M + 2 + δ.sub.SRING N-WT STORAGE w/N WTS 512 512δ.sub.M + 2 + δ.sub.S N-2 to 1 ADDERS 1,024 1,024δ.sub.M + 2 + δ.sub.S N-SIGMOID GENERATORS 1-CIRCULAR BUSSNAP N.sup.2 -MULTIPLIERS δ.sub.M + 2(log.sub.2 N)C + δ.sub.S 128 δ.sub.M + 14 + δ.sub.S N.sup.2 -WT STORAGE w/1 WTS 512 δ.sub.M + 18 + δ.sub.S 2N(N-1)-COMMUNICATING 1,024 δ.sub.M + 20 + δ.sub.S ADDERS 2N-SIGMOID GENERATORBIT- N.sup.2 -MULTIPLIERS 2(log.sub.2 N)C + 2(L)C + δ.sub.S 128 78 + δ.sub.SSERIAL N.sup.2 -WT STORAGE w/1 WTS 512 82 + δ.sub.SSNAP 2N(N-1)-COMMUNICATING 1,024 84 + δ.sub.S ADDERS 2N-SIGMOID GENERATORSNAP-ROW PERFORMANCE #ROWS(N)-MULTIPLIERS N(#ROWS) WT STORAGE N.sup.2 /(N(#ROWS)) WTS #ROWS(N-1)-DUAL PATH ADDERS ##STR3## N(#ROWS-1)- COMMUNICATING ADDERS N + #ROWS SIGMOID GENERATORS__________________________________________________________________________ | The neural computing paradigm is characterized as a dynamic and highly parallel computationally intensive system typically consisting of input weight multiplications, product summation, neural state calculations, and complete connectivity among the neurons. Herein is described neural network architecture called SNAP which uses a unique intercommunication scheme within an array structure that provides high performance for completely connected network models such as the Hopfield model. SNAP's packaging and expansion capabilities are addressed, demonstrating SNAP's scalability to larger networks. Each neuron generating a neuron value from a selected set of input function elements and communicating said neuron value back to said set of input function elements. The total connectivity of each neuron to all neurons is accomplished by an orthogonal row-column relationship of neurons where a given multiplier element operates during a first cycle as a row element within an input function to a column neuron, and during a second cycle as a column element within an input function to a row neuron. | 6 |
CROSS REFERENCE TO RELATED APPLLICATION
This application claims the benefit of U.S. Provisional Application Ser. No. 60/027,255, filed Sep. 30, 1996, and is a divisional of U.S. patent application Ser. No. 08/927,146, filed Sep. 3, 1997, now U.S. Pat. No. 5,941,464, entitled "Manure Spreader Apparatus".
FIELD OF THE INVENTION
The present invention relates generally to a tank type manure spreader and more particularly to apparatus for containing manure, transporting the contained manure to a discharge area, such as a field, and dispensing the manure onto the field.
BACKGROUND OF THE INVENTION
Various mobile equipment exists for dispensing a wide range of fertilizers onto lawns, gardens and fields. Of particular interest with respect to the present application is fertilizer spreading apparatus of the type commonly referred to as a manure spreader, which as its name implies is typically used to spread animal wastes, such as barnyard manure. In a typical farm operation, manure is hauled from a confined holding area and dispensed as fertilizer onto fields where crops are to be grown. To this end, a variety of manure spreaders have been developed over the years to haul and distribute different types of manure. For instance, conventional box spreaders are preferred for handling dry, clumpy types of manure.
Box spreaders, well known in the agricultural implement art, include a box-like container having a conveyor moveable along the floor for transferring the material to the rear of the box. Rotating beaters, typically paddle shaped, are mounted in a transverse fashion at the rear of the box to engage and break up the material that has been conveyed rearwardly. The paddles also serve to distribute the broken up material in a swath as the spreader is transported across the field.
Even though box spreaders have proven to be effective for dry, clumpy manure, they have not been as effective for transporting and distributing manure having a significant liquid content. One problem is that box spreaders are not sealed, resulting in leakage when liquid or semi-liquid is being transported to the field, which in many instances is over publicly traveled roadways. To overcome this and other problems encountered with respect to the handling of liquid types of manure, spreaders have been developed in which the material is held in a leak resistant container.
In one common design the container is a tank having a cross section that is generally V-shaped with inwardly angled sides for guiding the material to an auger assembly mounted in the bottom thereof, which in turn conveys the material to a distribution assembly for discharge from the tank. This type of spreader, as opposed to a box spreader, is commonly referred to as a tank spreader and is well adapted for handling cattle manure in liquid or slurry form as well as other types of manure such as swine and poultry manure.
In tank type spreaders, there are various arrangements employing either one or two augers for moving the material to the discharge area. A typical example of a single auger machine is shown in U.S. Pat. No. 5,221,049, issued Jun. 22, 1993 in the name of Gilbert W. Linde, et al. In this spreader a single auger in the bottom of the tank conveys material to a distribution assembly that expels material out the side of the tank. The spreaders described in the following paragraphs all relate to double auger machines.
In U.S. Pat. No. 5,386,943, issued Feb. 7, 1995 in the name of Kenneth J. Peters, a dual auger arrangement is depicted in which a transverse beater type expeller is mounted above the augers to engage material as it is urged rearwardly by the augers. In U.S. Pat. No. 5,199,638, issued Apr. 6, 1993 in the name of Thomas R. Fischer, and U.S. Pat. No. 5,275,335, issued Jan. 4, 1994 in the name of Stanley W. Knight, et al, dual augers, rotating in the same direction, are utilized in a cooperative manner to convey material to a side discharge assembly. In the '335 patent one auger is mounted above the other, while in the '638 patent the augers are mounted in a side-by-side fashion at the same elevation. In still another representative prior art machine, dual augers are shown in U.S. Pat. No. 5,435,494, issued Jul. 25, 1995 also in the name of Stanley W. Knight, et al. In one embodiment of the '494 machine the augers are counter rotating and have different diameters, one of which is used as a feed auger and the other of which is used as a discharge auger.
In another type of prior art tank spreaders, dual augers urge material to expellers that are mounted for rotation about rearwardly located horizontal shafts. Exemplary of this combination are U.S. Pat. No. 3,871,588, issued Mar. 18, 1975 in the name of John B. Long, et al, U.S. Pat. No. 4,124,166, issued Nov. 7, 1978 in the name of Gustave Lucas, and U.S. Pat. No. 4,801,085, issued Jan. 31, 1989 in the name of Thomas R. Fischer.
In yet another arrangement wherein dual augers urge material rearwardly for discharge, expellers are mounted to rotate about vertical axes. Typical of this latter arrangement, is U.S. Pat. No. 5,501,404, issued Mar. 26, 1996 in the name of Donald A. Meyer, et al, which in the principal embodiment shows rotary expeller means with blades extending from a vertical shaft mounted rearwardly and external of the tank.
Another example of the latter arrangement is an early U.S. Pat. No. 2,296,909, issued Sep. 29, 1942 in the name of Merrills L. Dake, showing a truck mounted spreader used for spreading granulated material, such as salt, sand, or the like. In this spreader the augers, mounted within a flat bottomed tank, are counter rotating to discharge the material through an opening in the back wall of the tank onto distribution discs rotating about vertical shafts.
Notwithstanding the numerous kinds of spreaders available for transporting and discharging slurry type manures that are somewhat liquid in consistency, applicants have embraced additional needs for a reliable spreader that effectively spreads manure in a desired pattern on the field. More particularly, applicants have determined that the general need exists for spreading material, having a range of liquification from a sticky type pen manure to a wetter type, such as municipal sludge, without disruption of operation regardless of weather conditions. The below described apparatus is a new and useful solution, not heretofore devised, to these problems that addresses these needs.
SUMMARY OF THE INVENTION
An important object of the present invention is to overcome the problems mentioned above by providing improved mobile apparatus for transporting and distributing material such as manure.
In pursuance of this and other important objects the present invention contemplates a new and improved material spreader having a mobile tank for receiving and discharging material to be distributed, a pair of augers rotatably mounted in the tank for conveying material received in the tank to a discharge area, an opening in the tank in the vicinity of the discharge area, and distribution means mounted outside the tank for receiving material discharged through the opening and distributing it as the tank is transported over a field. The distribution means comprise a pair of slingers each associated with a corresponding auger and comprising a flat material receiving spinner member having material engaging means extending upwardly therefrom. The distribution means further comprising a pair of rotatably mounted vertical shafts on which the material receiving spinner members are mounted, and means for rotating the shafts in opposite directions, whereby material received in the tank is urged toward the discharge area by the augers and dropped on the spinner members via the opening whereupon it is engaged by the material engaging means and propelled away from the tank.
The invention more particularly contemplates a material spreader of the general type described above wherein the augers have an end portion with interrupted flighting extending outwardly from the rear wall of the tank. The augers are operatively disposed above the spinner members mounted on vertical driven shafts extending through the interruptions in the flighting.
The foregoing and other objects, features and advantages of the invention will appear more fully hereinafter from a consideration of the detailed description which follows, in conjunction with the accompanying sheets of drawings wherein both the principal embodiment and a second embodiment of the present invention are illustrated by way of example. It is to be expressly understood, however, that the drawings are for illustrative purposes and are not to be construed as defining the limits of the invention.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a manure spreader.
FIG. 2 is a top view of the manure spreader shown in FIG. 1.
FIG. 3 is a view, taken from the right end of the manure spreader shown in FIGS. 1 and 2.
FIG. 4 is an enlarged fragmentary top view of the rear portion of the auger on the right side of the manure spreader shown in FIGS. 1-3.
FIG. 5 is an end view of the auger shown in FIG. 4.
FIG. 6 is a fragmentary side elevational view of a manure spreader in which the elements of the claimed invention are incorporated.
FIG. 7 is a fragmentary top view of the manure spreader shown in FIG. 6.
FIG. 8 is a view, taken from the right end of the manure spreader shown in FIGS. 6 and 7.
DESCRIPTION OF THE INVENTION
Referring now to the drawings for a more detailed description of the present invention, FIGS. 1, 2 and 3 show the side, top and end views of a manure spreader, generally designated by reference numeral 10, in which the elements of the present invention are incorporated. More specifically, spreader 10 includes a tank 11, with a capacity of 3000 gallons, mounted on a frame 12 supported by a pair of tandem ground engaging wheels 13, 14 on the left side, shown in FIG. 1, and a like pair of tandemly mounted ground engaging wheels 15 (only one shown) on the right side. A towing vehicle, such as a tractor, is hitched in towing and driving engagement with the spreader via a tongue 16 and a drive shaft 17. Rotative force from shaft 17 (attached to tractor power take-off ("PTO") shaft in conventional manner) is coupled to hydraulic pump 18 via drive belt 20.
Tank 11 comprises front wall 21, rear wall 22, a pair of inclined side walls 23, 24, and bottom 25 comprising a pair of side-by-side, adjacent, arcuate troughs separated by an intermediate interconnecting area. Mounted within the trough are a pair of augers 26, 27 having flighting 28, 30 with a circular projection of approximately 24 inches that is accommodated by the radius of the arcuate troughs 31, 32, respectively. The augers, mounted in bearing assemblies 33, 34 affixed to the rear wall 22, are driven by a pair of hydraulic motors 35, 36 to rotate flighting 28, 30 in opposite directions (arrows a and b) that urge material in the bottom of tank 11 in a rearward direction. Motors 35, 36 operatively coupled to pump 18 in a conventional manner, are mounted on frame 12 within enclosure 39 extending forwardly from front wall 21.
A discharge area in the rear bottom vicinity of tank 11 includes arcuate openings 37, 38 in the bottom of the rear most part of the troughs. Directly below the opening are a pair of slinger assemblies comprising 30 inch circular spinner elements 40, 41, mounted for rotation in directions c, d, respectively, via driven shafts 42, 43 extending downwardly from hydraulic motors 46, 47 secured to back wall 22 of tank 11. Motors 46, 47 are coupled to pump 18 via appropriate hydraulic lines 48 in a conventional manner for providing rotative force to the slinger assemblies. Extending upwardly from spinners 40, 41 are a plurality of material engaging fins 44, 45, respectively, for engaging material discharged from the tank through openings 37, 38. The number and shape of the fins on the spinners is varied to accommodate the material and desired spread pattern of the material being distributed rearwardly from the spreader as it traverses the field. The spread pattern can also be changed by varying the volume of material delivered to the slingers. To this end, gate 50 (FIGS. 1 and 2) can be slideably adjusted to block or completely close openings 37, 38. Gate 50 is shown in the full open position.
Now turning to FIGS. 4 and 5 for a detailed description of a feed assist assembly, generally designated by reference numeral 51. Also see FIG. 2, where the feed assist assembly is shown in the vicinity of opening 38. Only one feed assist assembly will be described hereinafter; however, it should be understood that identical assemblies are used, one being associated with each of the augers. Rearwardly of where flighting 30 of auger 27 terminates along core 52, adjacent opening 38 (see FIG. 2), are four paddle assemblies 53, 54, 55, 56, secured axially along core 52. Four paddles 57, 58, 60, 61, extending at 90 degree increments, are secured to rigid elements 62, 63, 64, 65, welded to core 52, by shear bolts 71, 72, 73, 74. Completing each paddle assembly, using assembly 56 as an example, are semi-circular clamping elements 66, 67 that conform to the outer surface of core 52, and are held snugly in place by bolts 68, 70 for conjoint rotation of the paddles with auger 27.
Thus, under conditions where feed assist assembly 51 is rotated in direction b, the forwardly facing surfaces 75, 76, 77, 78 of paddles 57, 58, 60, 61, respectively, engage manure in the discharge area for delivery to the slingers via the openings in the bottom of tank 11. In the event the material is frozen to a degree that it is not being properly fed through the opening the shear bolts will shear at a predetermined level of force in a conventional manner. When this occurs rigid elements 62, 63, 64, 65 will break away from the paddles and continue to rotate with auger 27 and slice through the rigid material that is otherwise immovable via the paddles. The clamping force holding the paddles is set at a predetermined level sufficient to permit independent rotation of core 52 within the semi-circular clamping elements when the shearing force of the shear bolts is attained.
A spreader is shown in FIGS. 6, 7 and 8 of the drawings in which the elements of the claimed invention are incorporated. In this apparatus the rearmost portions of the augers 26', 27' comprise interrupted flighting 28', 30', that extends beyond the rear wall 22' to discharge material rearwardly from the tank to compartment 80 and then downwardly to spinners 40', 41', which are disposed on shafts 42', 43' extending below compartment 80'. Hydraulic motors 46', 47' rotate shafts 42', 43' which extend through the interruptions in flighting 28', 30. The forward components of the spreader (not shown) are identical to those shown in FIGS. 1, 2 and 3.
Of the many implicit and explicit advantages of the present invention one of the most important is the provision of a spreader that accommodates and distributes efficiently and effectively large amounts of material, especially slurry type manure of varying consistencies, regardless of weather conditions.
While preferred structure in which the principles of the present invention are shown and described above, it is to be understood that the invention is not limited to such preferred structure, but that, in fact, widely different means of varying scope and configuration may be employed in the practice of the invention. | A material spreader comprising a mobile tank for receiving and discharging waste material, such as manure. The spreader includes a conveying assembly comprising one or more augers rotatably mounted in the tank for conveying material received in the tank to a discharge area. An opening in the vicinity of the discharge area permits material to be dispensed to a slinger assembly mounted outside the tank adjacent the opening. Material is distributed by the slinger in a controlled pattern as the tank is transported over a field. | 0 |
This application is a divisional application claiming priority from U.S. patent application Ser. No. 09/315,411, filed on May 20, 1999.
FIELD OF THE INVENTION
The field of this invention relates to suspending one tubular in another, especially hanging liners which are to be cemented.
BACKGROUND OF THE INVENTION
In completing wellbores, frequently a liner is inserted into casing and suspended from the casing by a liner hanger. Various designs of liner hangers are known and generally involve a gripping mechanism, such as slips, and a sealing mechanism, such as a packer which can be of a variety of designs. The objective is to suspend the liner during a cementing procedure and set the packer for sealing between the liner and the casing. Liner hanger assemblies are expensive and provide some uncertainty as to their operation downhole.
Some of the objects of the present invention are to accomplish the functions of the known liner hangers by alternative means, thus eliminating the traditionally known liner hanger altogether while accomplishing its functional purposes at the same time in a single trip into the well. Another objective of the present invention is to provide alternate techniques which can be used to suspend one tubular in another while facilitating a cementing operation and still providing a technique for sealing the tubulars together. Various fishing tools are known which can be used to support a liner being inserted into a larger tubular. One such device is made by Baker Oil Tools and known as a “Tri-State Type B Casing and Tubing Spear,” Product No. 126-09. In addition to known spears which can support a tubing string for lowering into a wellbore, techniques have been developed for expansion of tubulars downhole. Some of the techniques known in the prior art for expansion of tubulars downhole are illustrated in U.S. Pat. Nos. 4,976,322; 5,083,608; 5,119,661; 5,348,095; 5,366,012; and 5,667,011.
SUMMARY OF THE INVENTION
A method for securing and sealing one tubular to another downhole facilitates cementing prior to sealing and allows for suspension of one tubular in the other by virtue of pipe expansion techniques.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-4 are a sectional elevation, showing a first embodiment of the method to suspend, cement and seal one tubular to another downhole, using pipe expansion techniques.
FIGS. 5-11 a are another embodiment creating longitudinal passages for passage of the cementing material prior to sealing the tubulars together.
FIGS. 12-15 illustrate yet another embodiment incorporating a sliding sleeve valve for facilitating the cementing step.
FIGS. 16-19 illustrate the use of a grapple technique to suspend the tubular inside a bigger tubular, leaving spaces between the grappling members for passage of cement prior to sealing between the tubulars.
FIGS. 20-26 illustrate an alternative embodiment involving a sequential flaring of the inner tubular from the bottom up.
FIGS. 28-30 illustrate an alternative embodiment involving fabrication of the tubular to be inserted to its finished dimension, followed by collapsing it for insertion followed by sequential expansion of it for completion of the operation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a tubular 10 is supported in casing 12 , using known techniques such as a spear made by Baker Oil Tools, as previously described. That spear or other gripping device is attached to a running string 14 . Also located on the running string 14 above the spear is a hydraulic or other type of stroking mechanism which will allow relative movement of a swage assembly 16 which moves in tandem with a portion of the running string 14 when the piston/cylinder combination (not shown) is actuated, bringing the swage 16 down toward the upper end 18 of the tubular 10 . As shown in FIG. 1 during run-in, the tubular 10 easily fits through the casing 12 . The tubular 10 also comprises one or more openings 20 to allow the cement to pass through, as will be explained below. Comparing FIG. 2 to FIG. 1, the tubular 10 has been expanded radially at its upper end 18 so that a segment 22 is in contact with the casing 12 . Segment 22 does not include the openings 20 ; thus, an annular space 24 exists around the outside of the tubular 10 and inside of the casing 12 . While in the position shown in FIG. 2, cementing can occur. This procedure involves pumping cement through the tubular 10 down to its lower end where it can come up and around into the annulus 24 through the openings 20 so that the exterior of the tubular 10 can be fully surrounded with cement up to and including a portion of the casing 12 . Before the cement sets, the piston/cylinder mechanism (not shown) is further actuated so that the swage assembly 16 moves further downwardly, as shown in FIG. 3 . Segment 22 has now grown in FIG. 3 so that it encompasses the openings 20 . In essence, segment 22 which is now against the casing 12 also includes the openings 20 , thereby sealing them off. The seal can be accomplished by the mere physical expansion of segment 22 against the casing 12 . Alternatively, a ring seal 26 can be placed below the openings 20 so as to seal the cemented annulus 24 away from the openings 20 . Optionally, the ring seal 26 can be a rounded ring that circumscribes each of the openings 20 . Additionally, a secondary ring seal similar to 26 can be placed around the segment 22 above the openings 20 . As shown in FIG. 3, the assembly is now fully set against the casing 12 . The openings 20 are sealed and the tubular 10 is fully supported in the casing 12 by the extended segment 22 . Referring to FIG. 4, the swage assembly 16 , as well as the piston/cylinder assembly (not shown) and the spear which was used to support the tubular 10 , are removed with the running string 14 so that what remains is the tubular 10 fully cemented and supported in the casing 12 . The entire operation has been accomplished in a single trip. Further completion operations in the wellbore are now possible. Currently, this embodiment is preferred.
FIGS. 5-12 illustrate an alternative embodiment. Here again, the tubular 28 is supported in a like manner as shown in FIGS. 1-4, except that the swage assembly 30 has a different configuration. The swage assembly 30 has a lower end 32 which is best seen in cross-section in FIG. 8 . Lower end 32 has a square or rectangular shape which, when forced against the tubular 28 , leaves certain passages 34 between itself and the casing 36 . Now referring to FIG. 7, it can be seen that when the lower end 32 is brought inside the upper end 38 of the tubular 28 , the passages 34 allow communication to annulus 40 so that cementing can take place with the pumped cement going back up the annulus 40 through the passages 34 . Referring to FIG. 8, it can be seen that the tubular 28 has four locations 42 which are in contact with the casing 36 . This longitudinal surface location in contact with the casing 36 provides full support for the tubular 28 during the cementing step. Thus, while the locations 42 press against the inside wall of the casing 36 to support the tubular 28 , the cementing procedure can be undertaken in a known manner. At the conclusion of the cementing operation, an upper end 44 of the swage assembly 30 is brought down into the upper end 38 of the tubular 28 . The profile of the upper end 44 is seen in FIG. 10 . It has four locations 46 which protrude outwardly. Each of the locations 46 encounters a mid-point 48 (see FIG. 8) of the upper end 38 of the tubular 28 . Thus, when the upper end 44 of the swage assembly 30 is brought down into the tubular 28 , it reconfigures the shape of the upper end 38 of the tubular 28 from the square pattern shown in FIG. 8 to the round pattern shown in FIG. 12 . FIG. 11 shows the running assembly and the swage assembly 30 removed, and the well now ready for the balance of the completion operations. The operation has been accomplished in a single trip into the wellbore. Accordingly, the principal difference in the embodiment shown in FIGS. 1-4 and that shown in FIGS. 5-12 is that the first embodiment employed holes or openings to facilitate the flow of cement, while the second embodiment provides passages for the cement with a two-step expansion of the upper end 38 of the tubular 28 . The first step creates the passages 34 using the lower end 32 of the swage assembly 30 . It also secures the tubular 28 to the casing 36 at locations 42 . After cementing, the upper end 44 of the swage assembly 30 basically finishes the expansion of the upper end 38 of the tubular 28 into a round shape shown in FIG. 12 . At that point, the tubular 28 is fully supported in the casing 36 . Seals, as previously described, can optionally be placed between the tubular 28 and the casing 36 without departing from the spirit of the invention.
Another embodiment is illustrated in FIGS. 12-15. This embodiment has similarities to the embodiment shown in FIGS. 1-4. One difference is that there is now a sliding sleeve valve 48 which is shown in the open position exposing openings 50 . As shown in FIG. 12, a swage assembly 52 fully expands the upper end 54 of the tubular 56 against the casing 58 , just short of openings 50 . This is seen in FIG. 13 . At this point, the tubular 56 is fully supported in the casing 58 . Since the openings 50 are exposed with the sliding sleeve valve 48 , cementing can now take place. At the conclusion of the cementing step, the sliding sleeve valve 48 is actuated in a known manner to close it off, as shown in FIG. 14 . Optionally, seals can be used between tubular 56 and casing 58 . The running assembly, including the swage assembly 52 , is then removed from the tubular 56 and the casing 58 , as shown in FIG. 15 . Again, the procedure is accomplished in a single trip. Completion operations can now continue in the wellbore.
FIGS. 16-19 illustrate another technique. The initial support of the tubular 60 to the casing 62 is accomplished by forcing a grapple member 64 down into an annular space 66 such that its teeth 68 ratchet down over teeth 70 , thus forcing teeth 72 , which are on the opposite side of the grappling member 64 from teeth 68 , to fully engage the inner wall 74 of the casing 62 . This position is shown in FIG. 17, where the teeth 68 and 70 have engaged, thus supporting the tubular 60 in the casing 62 by forcing the teeth 72 to dig into the inner wall 74 of the casing 62 . The grapple members 64 are elongated structures that are placed in a spaced relationship as shown in FIG. 17 A. The spaces 76 are shown between the grapple members 64 . Thus, passages 76 provide the avenue for cement to come up around annulus 78 toward the upper end 80 of the tubular 60 . At the conclusion of the cementing, the swage assembly 82 is brought down into the upper end 80 of the tubular 60 to flare it outwardly into sealing contact with the inside wall 74 of the casing 62 , as shown in FIG. 18 . Again, a seal can be used optionally between the upper end 80 and the casing 62 to seal in addition to the forcing of the upper end 80 against the inner wall 74 , shown in FIG. 18 . The running assembly as well as the swage assembly 82 is shown fully removed in FIG. 19 and further downhole completion operations can be concluded. All the steps are accomplished in a single trip.
FIGS. 20-25 illustrate yet another alternative of the present invention. In this situation, the swage assembly 84 has an upper end 86 and a lower end 88 . In the run-in position shown in FIG. 20, the upper end 86 is located below a flared out portion 90 of the tubular 92 . Located above the upper end 86 is a sleeve 94 which is preferably made of a softer material than the tubular 92 , such as aluminum, for example. The outside diameter of the flared out segment 90 is still less than the inside diameter 96 of the casing 98 . Ultimately, the flared out portion 90 is to be expanded, as shown in FIG. 21, into contact with the inside wall of the casing 98 . Since that distance representing that expansion cannot physically be accomplished by the upper end 96 because of its placement below the flared out portion 90 , the sleeve 94 is employed to transfer the radially expanding force to make initial contact with the inner wall of casing 98 . The upper end 86 of the swage assembly 84 has the shape shown in FIG. 22 so that several sections 100 of the tubular 92 will be forced against the casing 98 , leaving longitudinal gaps 102 for passage of cement. In the position shown in FIGS. 21 and 22, the passages 102 are in position and the sections 100 which have been forced against the casing 98 fully support the tubular 92 . At the conclusion of the cementing operation, the lower segment 88 comes into contact with sleeve 94 . The shape of lower end 88 is such so as to fully round out the flared out portion 90 by engaging mid-points 104 of the flared out portion 90 (see FIG. 22) such that the passages 102 are eliminated as the sleeve 94 and the flared out portion 90 are in tandem pressed in a manner to fully round them, leaving the flared out portion 90 rigidly against the inside wall of the casing 98 . This is shown in FIG. 23 . FIG. 25 illustrates the removal of the swage assembly 84 and the tubular 92 fully engaged and cemented to the casing 98 so that further completion operations can take place. FIGS. 24 and 26 fully illustrate the flared out portion 90 pushed hard against the casing 98 . Again, in this embodiment as in all the others, auxiliary sealing devices can be used between the tubular 92 and the casing 98 and the process is done in a single trip.
Referring now to FIGS. 27-30, yet another embodiment is illustrated. Again, the similarities in the running in procedure will not be repeated because they are identical to the previously described embodiments. In this situation, the tubular 106 is initially formed with a flared out section 108 . The diameter of the outer surface 110 is initially produced to be the finished diameter desired for support of the tubular 106 in a casing 112 (see FIG. 28) in which it is to be inserted. However, prior to the insertion into the casing 112 and as shown in FIG. 28, the flared out section 108 is corrugated to reduce its outside diameter so that it can run through the inside diameter of the casing 112 . The manner of corrugation or other diameter-reducing technique can be any one of a variety of different ways so long as the overall profile is such that it will pass through the casing 112 . Using a swage assembly of the type previously described, which is in a shape conforming to the corrugations illustrated in FIG. 28 but tapered to a somewhat larger dimension, the shape shown in FIG. 29 is attained. The shape in FIG. 29 is similar to that in FIG. 28 except that the overall dimensions have been increased to the point that there are locations 114 in contact with the casing 112 . These longitudinal contacts in several locations, as shown in FIG. 29, fully support the tubular 106 in the casing 112 and leave passages 116 for the flow of cement. The swage assembly can be akin to that used in FIGS. 5-11 in the sense that the corrugated shape now in contact with the casing 112 shown in FIGS. 29 at locations 114 can be made into a round shape at the conclusion of the cementing operation. Thus, a second portion of the swage assembly as previously described is used to contact the flared out portion 108 in the areas where it is still bent, defining passages 116 , to push those radially outwardly until a perfect full 360° contact is achieved between the flared out section 108 and the casing 112 , as shown in FIG. 30 . This is all done in a single trip.
Those skilled in the art can readily appreciate that various embodiments have been disclosed which allow a tubular, such as 10 , to be suspended in a running assembly. The running assembly is of a known design and has the capability not only of supporting the tubular for run-in but also to actuate a swage assembly of the type shown, for example, in FIG. 1 as item 16 . What is common to all these techniques is that the tubular is first made to be supported by the casing due to a physical expansion technique. The cementing takes place next and the cementing passages are then closed off. Since it is important to allow passages for the flow of cement, the apparatus of the present invention, in its various embodiments, provides a technique which allows this to happen with the tubular supported while subsequently closing them off. The technique can work with a swage assembly which is moved downwardly into the top end of the tubular or in another embodiment, such as shown in FIGS. 20-26, the swage assembly is moved upwardly, out of the top end of the tubular. The creation of passages for the cement, such as 34 in FIG. 8, 76 in FIG. 17A, or 102 in FIG. 22, can be accomplished in a variety of ways. The nature of the initial contact used to support the tubular in the casing can vary without departing from the spirit of the invention. Thus, although four locations are illustrated for the initial support contact in FIG. 8, a different number of such locations can be used without departing from the spirit of the invention. Different materials can be used to encase the liner up and into the casing from which it is suspended, including cement, blast furnace slag, or other materials, all without departing from the spirit of the invention. Known techniques are used for operating the sliding sleeve valve shown in FIGS. 12-15, which selectively exposes the openings 50 . Other types of known valve assemblies are also within the spirit of the invention. Despite the variations, the technique winds up being a one-trip operation.
Those skilled in the art will now appreciate that what has been disclosed is a method which can completely replace known liner hangers and allows for sealing and suspension of tubulars in larger tubulars, with the flexibility of cementing or otherwise encasing the inserted tubular into the larger tubular.
The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made without departing from the spirit of the invention. | A method for securing and sealing one tubular to another downhole facilitates cementing prior to sealing and allows for suspension of one tubular in the other by virtue of pipe expansion techniques. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a divisional of co-pending U.S. application Ser. No. 10/205,789 filed Jul. 26, 2002, the teachings of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention is directed at an animal feeder in general and more particularly to a cage-mounted feeder which positions one or more feeding dishes away from the cage's perimeter and toward the center of the cage so that the scattering of feed is contained substantially within the cage. The feeder allows the dish to be mechanically moved and positionally exchanged between the perimeter of the cage and a location within the cage for ease of access in filling, emptying or cleaning of the dish.
BACKGROUND OF THE INVENTION
[0003] Small animals, particularly birds, are often housed for long periods of time within some sort of cage. In order to feed these animals, it is necessary to gain access to the interior of the cage. It is also advantageous if the feeding station or one or more dishes are located away from the perimeter and towards the center of the cage so that any scatter of food or water does not fall outside the cage, and so that the animals (preferably birds) have room to access the dish without being encumbered by the walls of the cage.
[0004] Most cages have feeding dishes attached to the perimeter of the cage for ease of access by the caretaker and sometimes include a small door located in a sidewall of the cage, and separate from the main access door, to refresh/replace or clean the food and water dishes. Thus, when the food/water dish is placed at the perimeter of the cage, it makes it easy to service, but also makes it more likely that food will fall outside the cage. When the dish is located in the center of the cage, it is much more difficult to access and service, because one needs to open the main door to get to the dish, thereby engaging with the occupant of the cage who may want to escape, or play, or run and hide.
[0005] Various patents have been identified which seek to address the above referenced problem of scatter. For example, U.S. Pat. No. 5,713,305 to Oveta and Robert Hollaway discloses a feeder which is clamped to the wall of the bird cage and comprises a rigid extension bar which is not capable of maneuvering for access, but rather is stationary, permanently locating the feeding dish at the center of the cage. U.S. Pat. No. 5,289,796 discloses a bird feeder to be hung from a tree with a height adjustment to allow the entirety of the feeder to be lowered for gaining access thereto.
[0006] Attention is also directed to U.S. Pat. No. 5,634,430 entitled “Reduced Mess Bird Feeder” which discloses a bird feeder which is designed so that a feeding bird leaves a reduced amount of bird food in an area outside the bird cage when compared to a conventional bird feeder. Such feeder relies upon the use of a plurality of feeder dishes and a pedestal, the pedestal including a base permanently positioned within the cage center. In addition, attention is directed to U.S. Pat. No. 1,575,101 which appears to again disclose the permanent positioning of a bird feeder at the cage center. Other patents of general interest include U.S. Pat. No. 3,119,372 entitled “Bird Cage Feeder Device”, U.S. Pat. No. 3,415,226, entitled “Bird Feeder”.
[0007] In spite of all the above disclosures, there still remains a need for a consumer friendly feeding device that facilitates the ability to easily replenish the bird feeder, yet which also positions the feeder at a location within the cage to minimize scatter. The present invention, therefore, has as its principal object the development of such a bird or small animal feeding device that can be conveniently positioned at different locations within the cage so that the feeder can be readily accessed at a perimeter/door location, yet repositioned and relocated within the cage environment to reduce the amount of feed, seeds and husks that are naturally scattered by the bird or other animal, and to reduce the amount of attention necessary by the bird/animal owner to maintain a clean and healthy environment.
[0008] It is thus, also an object of this invention to provide an apparatus for feeding small animals or birds contained in a cage by providing a centralized feeder which can be maneuvered to the cage wall for access through the door by the caretaker.
[0009] It is a further object of this invention to provide a centralized feeder for a cage that can be positioned within the cage without the main cage door being open,
[0010] It is further object of this invention to provide a centralized feeder for a cage that does not require a secondary access door at the perimeter of the cage.
[0011] It is still further object of the present invention to provide a feeder apparatus for a cage that provides adjustability and maneuverability of the feeder apparatus to various locations within the cage for cleaning, rearrangement, etc.
[0012] It is a further object of this invention to provide a feeder apparatus that is easy to access and which substantially contains scattering of food and/or liquid inside the cage due to its position.
[0013] It is still further object of the present invention to provide a feeder apparatus containing the above mentioned attributes which can also simultaneously serve as a perch while the occupant feeds.
[0014] It is a still further object of the present invention to provide a maneuverable feeder apparatus for a cage which provides a means for supporting containers for water, food, etc
SUMMARY OF THE INVENTION
[0015] A feeder for a cage, designed to reduce the scattering of food and to provide a cleaner and healthier caged environment, wherein the cage has a wall and an interior space for housing an animal such as a bird, including a cage door. The feeder comprises a feeder mechanism which includes a feeder receptacle attached to an extension structure, wherein the extension structure extends between the receptacle and the wall of said cage. The extension structure is manually engageable and adjustable for positioning the feeder receptacle at a selected location in the interior space of the cage and at a selected location at a cage door for access to the feeder receptacle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] To better understand and appreciate the invention, refer to the following detailed description in connection with the accompanying drawings:
[0017] FIG. 1 is a perspective view of a cage feeder apparatus constructed according to one embodiment of the present invention.
[0018] FIG. 2 is a cross-sectional side view of the cage feeder apparatus of FIG. 1 .
[0019] FIG. 3 is a top view of the cage of FIG. 4 with the top bars removed for clarity according to a second embodiment of the present invention.
[0020] FIG. 4 is a perspective view of the second embodiment of the present invention.
[0021] FIG. 5 is a cross-sectional side view of the second embodiment of the present invention.
[0022] FIG. 6 is a perspective view of a cage feeder apparatus constructed according to a third embodiment of the present invention.
[0023] FIG. 7 is a cross-sectional side view of the feeder apparatus in a retracted position for servicing according to the third embodiment.
[0024] FIG. 8 is a partial perspective view of the pivoting mechanism of FIG. 4 .
[0025] FIG. 9 is another perspective view of another preferred embodiment of the present invention.
[0026] FIG. 10 is a cross-sectional view of the feeder apparatus of FIG. 9 .
[0027] FIG. 11 is another perspective view of another preferred embodiment of the present invention.
[0028] In the appended drawings common elements use the same numeric character but are distinguished by the addition of a letter to identify a common element between embodiments (for instance 10 , 10 A, 10 B, etc.).
DESCRIPTION OF PREFERRED EMBODIMENTS
[0029] The present invention comprises a feeder preferably having one or more dishes or feed receptacles which are connected to a push/pull or pivoting rod which extends outside the cage and is maneuverable in a variety of planes (in/out—xy-plane along the x axis, up/down—zx or zy-plane along the z axis) or axially in the xy-plane around a pivot point at the edge of the cage such that the dish can be easily placed at the center of the cage for feeding and moved close to the door of the cage for filling and cleaning. In addition, the positioning mechanism may also comprise a retractable/foldable arm, an arm pivoted off another location inside the cage other than the cage wall, or a combination of rods or arms that allow for positional adjustment in multiple planes. In the case of the feeder being suspended from the ceiling of the cage, the attachment mechanism may be flexible such as a cord.
[0030] The feeder of the present invention is attached to the exterior of the cage through a rod or series of rods which can be maneuvered to allow access by the animal/bird at the center of the cage and by the caretaker through a cage door.
[0031] While the cages shown in the drawings and described herein are drawn as rectangular in shape, the cages could be of nearly any shape (round, hexagonal, dome-shaped, etc.) to contain a small animal or bird as its temporary or permanent home. In addition, all of the various features illustrated and discussed below within each preferred embodiment are understood to be applicable within all of the preferred embodiments discussed herein.
[0032] FIG. 1 shows a preferred cage 10 which has a feeder mechanism installed therein. In the interest of clarifying the invention, only some of the bars of the cage are shown, while others have been removed. The feeder mechanism 20 as shown contains a receptacle 12 having two removable dishes or fixed cavities for containment of food 14 and water 16 . The receptacle 12 of the invention could contain more or less cavities depending on what may be desirably fed to the occupant of the cage.
[0033] The receptacle 12 travels on two rails 22 , 24 which are slidably engaged with hollow tubes 26 , 28 on the bottom of the receptacle 12 . The rails 22 , 24 are attached at opposite sides of the cage to act as a height locating device for the feeder receptacle between the door 40 of the cage and the cage floor. The rails 22 , 24 may also act as a perch for the cage occupant to use while feeding. A central rod 30 with a handle 32 is attached to the receptacle 12 and can be used to push or pull the receptacle 12 to a position near the center of the cage for feeding or to the door 40 at the edge of the cage for servicing (filling, emptying or cleaning the dishes or cavities in the receptacle 12 ).
[0034] The receptacle 12 may contain similarly shaped dishes which fit into the cavities of the receptacle 12 which may then be interchanged with other dishes for ease of cleaning, filling, etc.
[0035] FIG. 2 show the cage 10 A and feeder mechanism 20 A in cross-sectional side view, again with most of the cage bars removed for clarity of presentation. Here, the rod 30 A is extended nearly its full length to position the feeder mechanism 20 A near the center of the cage 10 A. As the arrow A indicates, by pulling on the handle 32 A, the feeder mechanism 20 A can be maneuvered to close proximity of the door 40 A of the cage 10 A. This eliminates the need to reach into the center of the cage to access the receptacle 12 A. Again, with the feeder near the center of the cage 10 A, spillage from the receptacle 12 A will be contained within the cage.
[0036] Turning to FIGS. 3-5 , a second preferred embodiment of the present invention is shown, where in FIG. 3 , the feeder mechanism 20 C can be easily maneuvered near the center of the cage or to the access door 40 B as shown by the arrow B. In this embodiment, a pivoting (see FIG. 3 for a top view with bars removed for clarity) mechanism 50 is located at the corner of the cage 10 D which can pivot the receptacle 12 C from near the center of the cage to the access door 40 B. FIG. 4 is a perspective view of the second embodiment of the present invention illustrating additional details of the pivot mechanism 50 B. The pivot mechanism comprises a hollow tube 56 which slips over the corner bar 52 of the cage 10 E and which sits on a fixed collar 54 which is firmly attached to the corner bar 52 , locating the height of the pivot mechanism 50 B and, thereby, the feed receptacle 12 D. As shown in FIG. 8 the fixed collar 54 B and tube 56 B may each include intermeshing teeth 59 which may act as a detent for positioning the feeder mechanism 20 D of FIG. 4 near the center of the cage 10 E. Thus, the feeder mechanism can be lifted slightly and rotated to a specific angle and on different planes inside the cage and the intermeshing teeth will guarantee it remains in that position. As shown in FIGS. 4, 5 and 8 a thumb screw 58 , 58 A and 58 B or wing nut may be engaged with a threaded hole in the tube 56 , 56 A to prevent unwanted horizontal movement of the feeder mechanism 20 D. It should be noted that as shown in FIG. 4 it may be advantageous to angle the sides of the feeder receptacle 12 C and 12 D to match the angle that the receptacle makes when it engages the wall of the cage. Receptacle 12 C and 12 D may have a removable dish inside.
[0037] FIG. 5 is a cross-sectional side view of FIG. 4 showing how the receptacle 12 E is supported by rod 60 and rod 62 which is angled down to a lower point on tube 56 A to provide vertical stability for receptacle 12 E. It should be noted that rods 60 and 62 may be firmly attached to the tube 56 A. Furthermore the rod attached to thumbscrews 58 A can be releasably engaged to hollow tube 56 A, as illustrated in FIG. 5 . Furthermore, this concept of fixed rods 60 and 62 and releasable thumbscrew 58 A apply to all other preferred embodiments herein.
[0038] A third preferred embodiment of the present invention is shown in FIGS. 6 and 7 illustrating a cage design where the access door 40 C is located in the top of the cage 10 F. Again, some of the cage bars have been removed in the FIGS. to provide clarity to the understanding of the present invention. In this preferred embodiment, gravity is used to assist in lowering the feed receptacle 12 F to its desired height in the cage. The mechanism for lowering the receptacle 12 F comprises a handle or ring 32 B, a rod 30 B which is slidably engaged with a hollow tube 56 C, which is attached to a central flat bar 76 spanning a portion of the top of the cage 10 F.
[0039] In FIG. 6 the feeder receptacle 12 F is shown as being in two portions with the rod 30 B centered between them for balance. The receptacle may comprise one, two or more removable dishes or fixed cavities surrounding the rod which may then be rotated under the cage door 40 C for access.
[0040] FIG. 7 is a cross-sectional side view of FIG. 6 showing the rod 30 C withdrawn from the cage such that the feeder receptacle 12 G is at the top of the cage and in close proximity to the cage door 40 D. FIG. 7 shows a spring clip 78 A mounted to the rod 30 C which secures the feeder receptacle 12 G in the up position while it is being accessed. The spring clip 78 A remains in an expanded position when the rod is extended into the cage (reference numeral 78 in FIG. 6 ) and is compressed when the rod 30 C is drawn through the tube 74 A until the spring clip 78 A clears the tube 74 A and expands back out to hold the receptacle 12 G in the up position (see FIG. 7 ). Compressing the spring clip 78 A, allows the clip and the rod 30 C to slide down through the tube 56 D and bring the receptacle 12 G into a lowered position for access by the occupant of the cage (see FIG. 6 ). In addition, thumbscrew 58 C conveniently holds tube 56 D in the up position and/or at any position in the vertical z-plane.
[0041] FIG. 9 illustrates yet another preferred embodiment of the present invention. In this embodiment, the feeder mechanism generally identified at 80 is shown in the form of a house configuration, wherein the feeder receptacles 82 for food and/or water are contained within the feeder, and are removable for ease of replenishing and cleaning. At or near the apex 84 of the house configuration an opening is provided to allow for connection to the rail 86 . As can be seen, rail 86 is preferably of square or rectangular shape, or other equivalent geometric shape to restrict rotation of the feeder 80 . Extension structure 88 is shown extending between said feeder 80 and the wall of the cage 90 . Preferably, in FIG. 10 , a side cross-sectional view of FIG. 9 , the extension structure 88 extends beyond the cage and includes a handle 92 to facilitate manual engagement by the user so that the feeder mechanism can be selectively positioned at the door 94 , which is illustrated in FIG. 10 is open position.
[0042] FIG. 11 illustrates yet another preferred embodiment of a feeder mechanism 96 . In this configuration the feeder mechanism is attached at its bottom location 98 via extension structure 100 , which, as shown, preferably comprises two elongated bar sections forming a general right angle configuration. However, in the broad context of the present invention, the extension structure may simply comprise a single bar section attached to the side of feeder mechanism 96 . In addition, it can be appreciated that extension structure 100 extends from the roof 102 the cage so that it can be manually engaged and positioned at a selected location in the interior space of the cage and at a selected location at the door opening 104 .
[0043] The present invention is not limited to the preferred embodiments described herein and could include any of a variety of mechanisms such as folding arm, extendable rod, pivoting, rotating or hanging mechanisms located on or near the perimeter of the cage that allow a feeder receptacle to be maneuvered from near the center of the cage to the perimeter of the cage in proximity to an access door.
[0044] In addition, the feeder mechanism described herein may be combined with a mechanical engagement means where upon opening of the cage door, the feeder mechanism is triggered to move the feeder receptacle automatically towards the cage wall and upon closing the cage door, the receptacle is positioned near the cage center.
[0045] The description and drawings illustratively set forth the presently preferred invention embodiment. We intend the description and drawings to describe this embodiment and not to limit the scope of the invention. Obviously, it is possible to modify these embodiments while remaining within the scope of the following claims. Therefore, within the scope of the claims, one may practice the invention otherwise than as the description and drawings specifically show and describe. | A feeder for a cage, designed to reduce the scattering of food and to provide a cleaner and healthier caged environment, wherein the cage has a wall and an interior space for housing an animal such as a bird, including a cage door. The feeder comprises a feeder mechanism which includes a feeder receptacle attached to an extension structure, wherein the extension structure extends between the receptacle and the wall of said cage. The extension structure is manually engageable and adjustable for positioning the feeder receptacle at a selected location in the interior space of the cage and at a selected location at a cage door for access to the feeder receptacle. | 0 |
ORIGIN OF THE INVENTION
This invention was made with Government support under contract NAS1-18585 awarded by NASA. The Government has certain rights in this invention.
FIELD OF THE INVENTION
This invention relates generally to airfoils and relates specifically to porous airfoils having reduced drag and increased lift properties when compared to solid airfoils of essentially the same configuration and under the same flight conditions.
BACKGROUND OF THE INVENTION
An airfoil can readily be optimized for one set of design constraints consisting of specified values for such parameters as lift, drag, pitching moment, thickness, chord, etc. Achieving this goal for multiple, oftentimes contradictory, sets of design constraints is the objective of the discipline of multi-point design for airfoils. Three basic approaches have, thus far, been employed to achieve multi-point design of an airfoil that will reduce drag and improve lift on a specific airfoil configuration. These approaches have involved (1) determining the contours of a single solid profile from some optimized average of several single point designs, (2) matching multiple design requirements by constructing multi-element wings, and (3) producing an airfoil shape that satisfies several design requirements and to remedy some unwanted flow phenomena with ad-hoc solutions, for example, providing slots to reduce the strength of recompression shocks occurring within a certain narrow speed range.
The first of these approaches can be successfully applied if the design points are sufficiently close spaced together. The second previous approach may cause problems in weight and structure, and sometimes creates new aerodynamic problems in itself due to the need for fairings to accommodate additional gear that must be blended into the overall wing design. The third approach can be useful in fixing a certain aerodynamic problem but usually fails to significantly broaden the operational range of a wing design.
There remains a definite need in the art for an improved airfoil design and process of making same that will satisfy several sets of design constraints over a wide speed range.
Accordingly, it is an object of this invention to provide a new and novel airfoil configuration that becomes self-adaptive to very dissimilar flow conditions, and thus, lends itself to applications in multi-point design for airfoils.
Another object of the present invention is to provide a porous airfoil that vents the airflow flowing over the airfoil to improve the lift and drag characteristics thereof at both subcritical and supercritical conditions.
Another object of the present invention is a process for constructing an airfoil.
Still another object of the present invention is an airfoil having cavities beneath porous upper and lower surfaces.
A still further object of the present invention is a process for making airfoils self-adaptive to dissimilar flow conditions.
Another object of the present invention is a new and novel design process for developing aerodynamic wing designs.
SUMMARY OF THE INVENTION
According to the present invention, the foregoing and additional objects of the present invention are attained by placing cavities with contoured barrier walls, formed by a core piece, beneath a porous upper and lower surface patch that stretches over the nominal chord of an airfoil. These cavities permit the high pressures occurring in the nose and trailing edge regions to be vented toward the zones of relatively low pressure in the mid-section of the airfoil. This venting leads to inflow into the airfoil in the nose region which effectively reduces the nose radius. Further downstream along the porous airfoil, the venting process leads to recirculation bubbles that displace the enveloping streamlines and thereby shift the effective position of maximum thickness further aft while increases its magnitude. The magnitude of these modulations of the flow field in the vicinity of a profile depend on the angle of attack, the degree of porosity, free stream Mach number and the shape of the baseline airfoil.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant advantages thereof will become more apparent as the same becomes better understood by reference to the following drawings wherein:
FIG. 1 is a sectional view of an exemplary porous airfoil according to the present invention;
FIG. 1a is a partial, perspective view of the airfoil shown in FIG. 1 with portions of the top airfoil skin broken away to illustrate the rib support structure therefor;
FIG. 2 is a plan view of a portion of one of the porous surfaces of the airfoil shown in FIG. 1 as seen looking in the direction of arrow II;
FIG. 3 is a somewhat schematic sectional view of the airfoil shown in FIG. 1 exaggerating the cavity depth to illustrate the venting technique created by the present invention;
FIG. 4 is a graphic comparison showing the effect of porosity on lift versus angle of attack for subcritical flow past a specific airfoil;
FIG. 5 is a graphic comparison similar to FIG. 4 illustrating the effect of porosity on lift versus angle of attack for supercritical flow past the same airfoil;
FIG. 6 is a graphic comparison by means of drag polars demonstrating the effect of porosity on the same airfoil and at the Mach number employed in the illustration of FIG. 5; and
FIG. 7 is a schematic illustration of the relative thickness versus chord of the self-adaptive airfoil effect utilizing the porosity of the present invention to effectively obtain different shape solid airfoil results at two selected Mach numbers and angles of attack.
DETAILED DESCRIPTION
Referring now to the drawings and more particularly to FIG. 1, there is shown a porous airfoil according to the present invention and designated generally by reference numeral 10. Airfoil 10 is provided with an external skin or outer layer 11 having a porous top wall surface 12 and a porous bottom wall surface 14. A barrier wall or core piece 15 extends chordwise along the entire chord of airfoil 10. A forward portion of barrier wall 15 is provided with an arcuate contour and serves as support for skin 11 at the leading edge portion 16 of airfoil 10. The aft portion of barrier wall 15 tapers to a sharp edge and serves to support skin 11 at the trailing edge 17 of airfoil 10. Top porous wall 12 and bottom porous wall 14 are of identical construction and are continuations of skin 11 and integrally secured to barrier wall 15 at the respective leading and trailing edges 16, 17 thereof. Except for the attachment points at the leading and trailing edge surfaces, top porous wall surface 12 and bottom wall surface 14 are spaced from barrier wall 15 to thereby form separate cavities 19,20 between barrier wall and the respective porous top and bottom wall surfaces 12,14. Suitable spars or ribs 13 (FIG. 1a) extend along the chord of airfoil 10 for support and attachment of skin 11 thereto at spaced intervals along the airfoil span, as will be further explained hereinafter. A trough 13a, formed between each pair of ribs 13, constitutes the cavities 19 between barrier wall 15 and top porous top wall surface 12. Identical ribs and troughs (not shown) are provided as support for bottom wall surface 14 and serve to form cavities 20 between barrier wall 15 and bottom wall surface 14.
Cavities 19,20 are each of substantially equal depth and extend from the exterior surface of respective top and bottom surfaces 12, 14 through the respective pores 22,24 therein to the surface of barrier wall 15, as indicated by arrow pair a--a. The depth of cavities 19,20, or the distance between arrows a--a, would normally be in the range of one and one-half to three percent of the chord. Barrier wall or core piece 15 in the illustrated embodiment is shown as constructed of solid material. While this is a suitable design for a wind-tunnel model, airfoil designs for flight vehicles would normally use some lightweight construction involving honeycomb, spars, struts, or the like. The entire skin 11, including top wall surface 12 and bottom wall surface 14, is of uniform thickness, as indicated by arrow pair b--b for top wall 14. The thickness for these surfaces 12,14 would normally be in the range of 0.010 to 0.020 inch.
Referring to FIG. 2, a plan view of a portion of bottom wall surface 14 is shown as seen looking in the direction of arrow II of FIG. 1. This view illustrates one exemplary bore diameter size, bore arrangement, and the spacing between individual bores 24. As shown therein, the diameter of each individual bore 24 is designated by arrow pair c--c, while the chordwise spacing between individual adjacent bores is designated by arrow pair e--e. The spanwise spacing between individual adjacent rows of bores 24 is designated by arrow pair d--d. All bores 24 in a specific configuration are normally of equal diameter (c--c), and in the range of 0.0025 to 0.010 inch. The distance between arrows e--e, or the minimum chordwise spacing between individual bores 24 is within the range of 0.0050 to 0.025 inch, while the distance between arrows d--d or the spanwise spacing between adjacent rows of bores 24 is in the range of 0.10 to 0.20 inch. Depending on a particular choice for skin thickness, bore diameter, chordwise and spanwise spacing of the bores, the geometric porosity (i.e., the total hole area versus the airfoil surface area) ranges from 2.5 to 10 percent.
The bore size, spacing between the rows and spacing between adjacent bores would normally be the same in both the top and bottom wall surfaces in a specific airfoil 10.
Referring now to FIG. 3, a schematic representation of the venting of the air flow through cavities 19,20 is shown. As denoted by the arrows, the high pressure air flow at the leading edge or nose portion 16 of airfoil 10 enters cavities 19,20 and is vented toward, and exits at the zones of relative low pressure in the midsection of airfoil 10. This venting technique leads to inflow into airfoil 10 in the nose or leading edge region 16 to effectively reduce the airflow nose radius. Further downstream along porous airfoil 10, the venting process leads to recirculation bubbles which exit airfoil 10 at substantially the mid-chord section thereof and serve to displace the enveloping streamlines of the airflow about airfoil 10. This shifts the effective position of the airfoil maximum thickness further aft and increases its magnitude, as will be more clearly explained hereinafter. The magnitude of these modulations of the flow field in the vicinity of a specific airfoil profile 10 depend on the airfoil angle of attack, the degree of porosity, the free stream Mach number and the shape of the baseline airfoil.
In a computational pilot study of the present invention, the Euler equations were solved for transonic flow (0.63≦M.sub.∞ ≦0.8, 0°≦α≦2°) over the known NACA 0012 airfoil and over supercritical airfoils with solid, as well as porous surfaces. The porous surfaces studied were as illustrated in FIG. 1 with the porous top wall 12 and bottom wall 14 surfaces stretching over the entire airfoil chord between nose leading edge 16 and trailing edge 17, and with cavities 19,20 disposed beneath the top and bottom surfaces 12,14.
FIGS. 4 and 5 graphically demonstrate that porosity applied to a NACA 0012 airfoil configuration dramatically increases lift for both subcritical (M.sub.∞ =0.63, FIG. 4) and supercritical (M.sub.∞ =0.80, FIG. 5) air flow.
As indicated by the drag polars in FIG. 6, the wave drag taken at constant lift for supercritical flow past a porous NACA 0012 profile is up to one order of magnitude lower than for its solid counterpart. This phenomenon occurs for ∞≦0.5° where, for any fixed angle of attack, porosity of the present invention leads to additional lift without any apparent increase in wave drag, as graphically shown in FIG. 6.
Referring now to FIG. 7, an illustration of the novel self-adaptive capability, or responsiveness to dissimilar flow conditions of a porous NACA 0012 configured airfoil constructed in accordance with the present invention, is shown. Using the calculated porous surface pressure distribution as target pressures, equivalent solid airfoil shapes were constructed using a computational design tool. As illustrated in this FIG., the subcritical equivalent airfoil basically retains the drop shape of the NACA 0012 profile, while it has become thicker and asymmetric. Thus, incidence as well as camber constitute the lift of the porous variant of the NACA 0012 airfoil whereas for a solid NACA 0012 airfoil, incidence is the sole lift producing mechanism. The supercritical companion piece reveals a distinct flattening of the upper surface combined with a hump-shaped closure towards the trailing edge, typical for high-speed airfoils.
The effectiveness of porosity has also been demonstrated for an already optimized supercritical airfoil wherein, a specific porous surface in combination with separate top and bottom cavities to promote airflow venting, leads to an expansion of the operational Mach number and incidence range. In general, it may be said that by employing the teachings of the present invention to make airfoils self-adaptive to dissimilar flow conditions, an entirely new area in aerodynamic wing design is created.
Although the invention has been described relative to specific embodiments thereof, it is not so limited and there are numerous modifications and variations thereof that will be readily apparent to those skilled in the art in the light of the above teachings. For example, cavities 19 and 20 could be of diverse depth, one or both could be varied along the chord, or otherwise within the scope of the invention. Also, the exterior configuration of barrier wall or core piece 15 could be provided with different contours to tailor the flow in cavities 19,20 to specific design requirements.
Skin 11 forming top and bottom wall surfaces 12 and 14 is conventionally constructed of suitable thin, lightweight metal such as aluminum, aluminum alloys, titanium, or the like, that inherently have some degree of flexibility. These walls, as well as the inner core piece 15, could be constructed of different gauge sheet metal or other flexible materials to satisfy specific design goals. In addition, the area of the porous surfaces may be divided into specific patches or zones with single or multiple cavities being provided for the various porous patches to provide additional control mechanisms. Also, the individual bores constituting a specific porous surface may be of diverse diameters, the rows thereof may be uniform or staggered and the spacing between individual bores in the same or different zones may be varied for additional controls. Active blowing or suction may also be employed to provide an additional means of manipulating the flow of porous airfoils. Also, the porous surfaces may be confined to either the top or bottom of the airfoil in some instances.
These and other modifications and variations of the invention will appear obvious to those skilled in the art in the light of the above teachings.
It is therefore to be understood that within the scope of the appended claims, the invention may be practiced other than as specifically described herein. | A porous airfoil having venting cavities with contoured barrier walls, formed by a core piece, placed beneath a porous upper and lower surface area that stretches over the nominal chord of an airfoil is employed, to provide an airfoil configuration that becomes self-adaptive to very dissimilar flow conditions to thereby improve the lift and drag characteristics of the airfoil at both subcritical and supercritical conditions. | 1 |
This application is a division of application Ser. No. 08/434,161, filed May 2, 1995, entitled METHOD AND APPARATUS FOR PARALLEL PROCESSING OF FUZZY RULES and now U.S. Pat. No. 5,796,917.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for calculation in parallel of multiple fuzzy logic inference rules. The present invention concerns also a circuit architecture for implementation of the parallel calculation.
Specifically the present invention relates to a method for parallel processing of multiple fuzzy logic inference rules organized in fuzzy sets or logical functions of multiple fuzzy sets including membership functions defined in a so-called discourse universe and said rules being configured essentially as IF-THEN rules with at least one antecedent preposition and at least one consequent implication and said prepositions including at least one term of comparison between the membership functions and a plurality of input data and the terms being separated by logical operators.
2. Discussion of the Related Art
Fuzzy logic has now been established as a technique capable of supplying solutions for broad classes of control problems for which conventional techniques, e.g. those based on Boolean logic, have proven unsuited, and for providing acceptable performance at acceptable cost.
Fuzzy logic supplies a method of modelling the ‘inaccurate’ modes of reasoning typical of the human mind and which play an essential role in the human ability to make decisions under conditions of uncertainty.
Fuzzy logic operates on a linguistic description of reality using a particular class of variables termed ‘linguistic variables’. The values of said variables include words or phrases of any natural or artificial language. Basically, to each variable is assigned a corresponding semantic meaning of the words or phrases which are used in the modelling of a given problem.
In addition, to each variable can be syntactically joined a set of values dependent upon it which can take on different meanings depending on the context in which they are employed. Said values are found starting from a primary term which represents the variable, from one of its contraries, and from a series of so-called modifiers of the primary term, as described in European patent application no. 92830095.3.
Each value assigned to a linguistic variable is represented furthermore by a so-called fuzzy set, a possibilistic distribution function which links each value of the variable corresponding definition domain known as the universe of discourse.
The functions which identify a fuzzy set in the universe of discourse of a variable are called membership functions FA. For example, a value FA=0 indicates the non-membership of the point in the fuzzy set identified by the function, while a value FA=1 indicates the certainty of membership of the point in the fuzzy set. The assembly of all the fuzzy sets of a linguistic variable is called a ‘term set’.
Membership functions are defined by means of a sample representation obtained by dividing the definition domain in m points and the interval [0, 1] in 1 levels.
At present, definition or storage in a fuzzy logic based electronic controller of the membership functions which identify the fuzzy sets represents one of the major constraints on development of new fuzzy logic applications and thus limits the theoretical potential of this methodology.
Indeed, if it is desired to implement the membership functions in hardware to reflect the semantics of the fuzzy concept and to obtain a correct incidence of a term in a rule, one is forced to use considerable memory space. This makes fuzzy logic advantageous only for those applications where the term set of the linguistic variable consists of a reduced number of membership functions.
The data for a membership function are normally stored in a memory word. In known devices the memory area occupied is thus negatively influenced by the number of data necessary for defining these membership functions.
In many cases it has proven sufficient to store triangular membership functions, generally not symmetrical, or trapezoid membership functions so as to reduce the amount of data necessary for their storage.
With these triangular or trapezoid membership functions, it is not at all necessary to store the values of the function at all points of the universe of discourse. It is sufficient to store only the points where the curve changes slope and the value of this slope.
Appropriate logical operations—termed ‘inferential’—which allow description of the behavior of a system with the change in input parameters are performable among the membership functions. These operations are performed by fuzzy rules which have generally a syntax of the following type:
IF X IS A , THEN Y IS B
where 1 is the input value, A and B are membership functions FA which represent system knowledge, and Y is the output value.
The part of the rule preceding the term THEN is called the ‘left’ or ‘antecedent’ part while the following part is called ‘right’ or ‘consequent’ part of the inference rule.
The implication between the antecedent part and the consequent part of a fuzzy rule is governed by two laws:
modus ponens: in it the truth of the implication (Th), i.e. of the consequent part of the rule, depends on that of the premise (Hp), i.e. the antecedent part of the rule;
modus tollens: in it occurrence of the implication (Th) which ensures correctness of the premise (Hp).
Adopting the modus ponens as the rule, the degree of truth of the entire rule cannot be greater than that of the antecedent part.
Since the antecedent part can be made up of one or more terms T corresponding to hypotheses of the type (F is F′) on the data F and on the membership functions F′ its overall degree of truth which we shall indicate by the symbol W in the following description depends on the inference operations on these same terms T.
In addition the overall degree of truth W takes on a determinate value by applying to these terms T the logical operators AND, OR and NOT.
Electronic data processing tools which allow performance of this type of operation require a particular architecture expressly dedicated to the set of inference operations which constitute the fuzzy logic computational model.
With reference to triangular or trapezoid membership functions FA such as those set forth in FIG. 1, a weight ∝ of a set of data I for an antecedent part term represented in the universe of discourse U by means of a membership function I′ means the greatest value of the intersection between the input data set I and the membership function I′ corresponding to said term T.
In a processor operating with fuzzy logic procedures there must be room for a circuit capable of calculating the overall degree of truth W regardless of the logical operators present.
Heretofore multivalue fuzzy logic inferences were calculated in different ways.
In a project developed at OMRON by T. Yamakawa et al. the inference processing circuit can operate analogically in parallel only on four rules whose antecedent part can have at most three terms.
In addition to this initial limitation, for design simplicity other constraints were imposed:
the terms T of the antecedent part of the rules can be separated only by logical operators AND;
the membership functions I′ of the term sets of the input variables I can only have an S, Z, trapezoid or triangular shape;
the inputs are deterministic, i.e. they correspond to an individual point P in the universe of discourse U.
An architecture of H. Watanabe et al. performs in parallel all the rules for the same output variable. The user is however limited in his choice of the variables with which he can work. These can be only four input variables and two output variables out of fifty-one rules, or two input variables and one output out of one hundred two rules.
A plurality of Watanabe circuits can be connected in cascade under control of a software program in such a manner as to process more than one hundred two rules. In this case moreover it is possible to introduce a feedback of the output signal on the input of one of the components.
In like manner circuits of this type can be connected to operate with a larger number of input variables.
These architectures however involve an increase in the area of silicon occupied since they require memories of greater size.
A third known solution is the Fuzzy Micro Controller of Neural Logix in which only symmetrical and linear membership functions (triangles, trapezes, etc.) are used. Since each antecedent part of a rule can contain up to a maximum of sixteen terms, there are sixteen fuzzifiers at the input of this circuit.
The Neural Logix circuit can process up to sixty-four rules. Variables to be controlled or fedback output variables can be applied as inputs.
In this processing circuit a neural network determines the smallest of the sixteen terms contained in the antecedent part of the rule. The overall degrees of truth W of all sixty-four antecedent parts are used to calculate the maximum value by means of a circuit having a single register which is continually updated on the basis of each evaluation of the weight of each antecedent part.
Lastly, a processor known in the trade as ‘WARP’ and manufactured by processes sequentially up to two hundred fifty-six rules whose antecedent parts are made up of four terms.
The architecture of the inferential part was designed to calculate the degree of truth of the premise by means of parallel computation on four α values. These α values are taken simultaneously from the data memory once the input variables are known.
In the case of rules whose antecedent parts contain more than four terms T separated by logical operators the processing is carried out by dividing said antecedent parts in several antecedent sub-parts each of which contains four terms in the antecedent part allowing for the partial truth level w of each antecedent sub-part obtained by means of a feedback to the inference calculation circuit.
All the circuits heretofore available to the technicians of the industry cannot be considered absolutely effective because their efficacy depends strongly on the type of application.
In particular, the architectures which give priority to parallel processing of the inference rules in such a manner as to gain processing time lose necessarily in occupied silicon area.
On the other hand reduction of the occupied memory area by a decrease in the number of computational units causes efficiency of parallel processing to depend strongly on the number of rules associated with each individual inference operation.
Actually, if all the inferences to be processed are characterized by the same number N FR of fuzzy rules there can be a less than optimal use of available resources each time the number of processing units N PU present in the architecture is not exactly a submultiple of the number N FR of fuzzy rules.
In this case the following relationship is not satisfied:
N FR mod N PU =0
i.e. N FR is not exactly divisible by the number N PU .
In practice it is not always possible to introduce a number of inferential units equal to the number of the rules describing the process. Typically one is forced to oversize or undersize the calculation structure.
The technical problem underlying the present invention is to identify a new parallel processing method for multiple fuzzy rules which would not depend on the number of terms making up the antecedent part of the rules or the logical operators linking them.
SUMMARY OF THE INVENTION
The present invention provides simultaneous processing of several rules which can be configured dynamically in a flexible manner on the basis of the characteristics of the different applications for which the fuzzy logic is designed.
In one aspect of the invention, parallel processing is used for various rules. The rules are divided so that no antecedent has more than a certain number of elements. New rules are created for the remaining elements of an antecedent which has more than the specified number. Each rules is processed in parallel to determine a weight. The weights of the rules are then combined to determine an overall truth level. In another aspect of the invention, all of the rules process the same number of elements in an antecedent. Neutral elements are added to rules having fewer elements. In another aspect of the present invention, processing is modular so that identical processing can be performed for various rules and antecedent elements in a tree structure.
Another aspect of the invention provides an apparatus for performing parallel processing. The apparatus may include several identical processing units arranged in a tree structure for processing the antecedents of rules. The processing units receive input data and operators, determine weights based upon the input data and combine the weights using the operators. In another aspect of the invention, the processing units include a control unit for providing the proper input data and operators to the processing unit so that each rule is properly processed.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIGS. 1A-1D show membership functions I′ of a possible term set and a set of input data I,
FIGS. 2A-2B show schematically possible circuit architectures designed for implementation of the method in accordance with the present invention,
FIG. 3 shows a detail common to the architectures of FIGS. 2A-2B,
FIG. 4 shows in greater detail the structure of the detail of FIG. 3, and
FIG. 5 shows schematically a circuit provided in accordance with the present invention for implementation of the multiple fuzzy rule parallel processing method.
DETAILED DESCRIPTION
With reference to FIGS. 1A-1D a membership function, indicated by I′, of a linguistic or logical variable M is represented by means of a vectorial system where along the axis of the abscissa is defined a so-called universe of discourse U while along the ordinate axis is defined a so-called degree of truth or membership G.
The input data are represented by the same reference system.
In FIGS. 1A-1D are shown four membership functions I′ which identify in the universe of discourse U fuzzy sets which are part of a so-called term set. The weights α I of each term T of an inference rule R, i.e., the highest value of the intersection between the set of input data I and the membership function I′ corresponding to said term T, are also shown.
As shown in FIGS. 2A and 2B, the present invention includes a new inferential unit 1 which determines exhaustively the overall degree of truth W in an inference rule R. The inferential unit 1 is provided by means of a modular structure which can be configured in such a manner as to process multiple fuzzy rules in parallel.
By way of example let us consider a rule R 1 formed as follows:
IF (A is A′) AND (NOT B is B′) OR NOT [(C is C′) AND (D is D′)] THEN
The antecedent part of this rule R 1 is made up of four terms Tj placed between round parentheses and takes on a value determined by applying thereto the logical operators present AND, OR and NOT, assigning to them decreasing priority in the order NOT, AND, OR.
In the graphs of FIGS. 1A-1D are shown the weights ∝ A , ∝ B , ∝ C and ∝ D for the four terms Tj:
∝ A =maxx [min( A, A ′)]
∝ B =maxx [min(not B, B ′)]
∝ C =maxx [min( C, C ′)]
∝ D =maxx [min( D, D ′)]
In fuzzy logic semantics, with the operators AND and OR are associated respectively minimum and maximum operations between two or more elements while with the operator NOT is associated a complementary operation for one in the universe U.
The exemplary rule R 1 is then solved in the method in accordance with the present invention in accordance with the following successive steps:
calculate the complement of one CTB corresponding to a first logical operator NOT of the term TB,
calculate the minimum partial truth levels w 1 and w 2 corresponding to operators OR, of the weights α i of the terms TA and CTB and TC and TD respectively:
w 1 =min [ a A ,(1 −a B )]
w 2 =min( a C −a D )
calculate the complement to one Cw 2 corresponding to another operator NOT of the partial truth level w 2 ,
evaluate the overall truth level W of the rule R 1 as maximum corresponding to a logical operator AND between the values w 1 and Cw 2 :
Ω=max( w 1 , Cw 2 )
In practice the input variables I can be reduced to a single value P in the universe of discourse U (then termed ‘crisp’ input). In these cases the truth level α j of each term T j the value of the membership function I′ corresponding to that input value P.
For the sake of simplicity we shall refer below in the description to this P type of input value.
In FIGS. 2A and 2B are shown schematically examples of possible circuit architectures designed for parallel processing of multiple fuzzy logic inference rules.
Specifically FIG. 2A shows a structure for simultaneous processing of several fuzzy rules with four terms in the antecedent part while FIG. 2B shows a tree structure for the processing of a fuzzy rule with more than four terms T in the antecedent part.
The circuit architectures of FIGS. 2A and 2B are inferential units 1 having modular structure and comprising a plurality of the same circuit elements designed for inferential processing. Said elements are indicated by number 2 and can be connected in parallel or in a tree structure.
This embodiment is based on a fuzzy system for a process with a universe of discourse U which can be represented by a seven-bit code and a degree of truth G which can be represented by a four-bit code.
The inferential unit 1 is represented in greater detail in FIG. 3 .
The inferential unit 1 in the example considered consists internally of four identical circuits 2 . Advantageously in accordance with the present invention each of these circuits 2 computes the premise of a rule.
Preferably the rules R have antecedent parts made up of only four terms T separated by three operators of the AND/OR type.
Each circuit 2 has two inputs I 1 and I 2 and an output O and processes a fuzzy rule R.
The input I 1 receives a set of data ALFA each of which is coded by means of sixteen bits and represents the values of the weights α and α′ to be processed. The input I 2 receives a set of logical operators OPC coded by means of three bits for the logical operations to be realized.
Specifically each circuit 2 receives in the data set ALFA four rules R to each of which correspond four fuzzy sets FS as well as a series of three logical operator codes OPC.
The coded signals OPC indicate the logical operations to be performed and specifically the logical operator AND is made to correspond to the logical value 1, i.e. the minimum fuzzy logic operation, while to the logic value 0 is made to correspond the logical operator OR, i.e. the maximum fuzzy logic operation.
All the circuits 2 supply as an output O the value OMEGA for the inference rule Ri processed.
The value OMEGA can represent the overall degrees of truth of four different rules R or, as an alternative, the partial truth levels w of a rule R with more than four terms T in the antecedent part on the basis of which the overall degree of truth Ω of the rule can be calculated.
As shown in FIG. 4 the sixteen values contained in ALFA are distributed on four lines corresponding to the four inference rules R to be processed simultaneously together with the codes OPC of the logical operations which must be performed between the terms Tj of each rule R.
In the case of a fuzzy rule R 2 whose antecedent part is made up of four terms Tj, i.e. the type:
IF ( A is A ′) AND ( B is B ′) AND ( C is C ′) AND ( D is D ′) THEN
the overall degree of truth Ω can be determined directly and simultaneously for the four terms T of the rule with a structure of the type shown in FIG. 3 .
In the case of a rule R 3 with more than four terms T in the antecedent part, i.e. of the type:
IF ( A is A ′) AND ( B is B ′) AND ( C is C ′) OR ( D is D ′) OR ( E is E ′) AND ( F is F ′) OR ( G is G ′) THEN
one can apply the method in accordance with the present invention separating the starting rule in several sub-rules with four terms in the antecedent part and a consequent term and introducing depending on necessity additional logical operators in such a manner as to obtain exactly four terms in the antecedent part for each sub-rule.
Introduction of these additional logical operators must leave unchanged the starting rule R 3 . With them are then associated the corresponding neutral elements. If the added operator is a logical OR it is followed by the term 0 while if the added operator is a logical AND it is followed by the term 1 .
After distribution in sub-rules it is possible to apply to each of them the processing method in accordance with the present invention to obtain partial truth levels w. The overall degree of truth Ω of the rule R is then obtained as the maximum or minimum of the partial weights w depending on whether the rule R was broken at an operator OR or AND respectively.
The exemplary rule R 3 can be broken in two sub-rules by adding an operator OR and the corresponding neutral element 0 obtaining:
IF ( A is A ′) AND ( B is B ′) AND ( C is C ′) OR ( D is D ′) THEN
IF ( E is E ′) AND ( F is F ′) OR ( G is G ′) OR 0 THEN
The overall degree of truth n will be the highest of the partial truth levels w 1 and w 2 since the starting rule R 3 was broken at an operator OR. The rule can be implemented by means of a tree structure of the same type as shown in FIG. 2 B.
These examples permit understanding of how the use of a modular structure in accordance with the present invention allows obtaining directly the N overall degrees of truth Ω of N distinct inference rules R (with N equal to four in the example considered) and each of which has N terms in the antecedent part or the N partial truth levels w for a given rule R with more than N terms in the antecedent part.
In this manner the processing method in accordance with the present invention reduces to an Nth the time required for processing of a set of fuzzy rules.
Naturally whether processing N inference rules R or a rule R with more than N terms in the antecedent part it is disadvantageous to insert a number of twin circuits equal to the number of fuzzy rules which determine the related output variable, i.e. a number of circuits equal to the process variables, in such a manner as to find the overall degree of truth Ω by making use of a single processing cycle. But it is reasonable to think of a system having a number of identical circuits which approaches most the number of rules by which the process under observation is described.
Indeed, one of the major advantages of the fuzzy rule processing method in accordance with the present invention is the repeatability of the basic inference structure. In this manner, by analyzing the process to be monitored, after determination of the number of the input variables and implications necessary for processing, the user can choose the number of inference units best suited to said structures for inferential calculation depending on whether the more stringent restraint is processing time or circuit size.
Even though the introduction of several functionally equivalent blocks involves increase in the sizes of the overall circuit the size of the circuit portion assigned to inferential computation is such as to permit several presences thereof in a processor operating with fuzzy logic procedures and especially when the phenomenon to be monitored requires reduced processing times. Indeed, the processing method in accordance with the present invention permits reducing processing time by (Nr−1) times where Nr is the number of twin structures, equal to the number of rules present, to be inserted in parallel. Thus, for example, if there were X rules to be processed in a single structure there would have to be performed X-processings while by employing X twin structures in parallel a single processing would be sufficient, thus reducing the total performance time by (X−1) times.
FIG. 5 shows the structure of a fuzzy rule processing circuit 6 comprising an inferential unit 1 which performs the method in accordance with the present invention.
The fuzzy rule processing circuit 6 includes a first decoder block 3 which receives at input data COMP through bus 31 and has an output connected through a bus 32 to a second sorter block 4 . The decoder block 3 has additional outputs connected through a bus 33 to a third selector block 5 and through a bus 34 to an inferential unit 1 respectively.
The sorter block 4 receives at input data RE through a bus 41 and data DA through a bus 42 . It is also connected at output through a bus 43 to the third selector block 5 .
The third selector block 5 has a plurality of outputs connected through multiple busses 51 to the inferential unit 1 .
The inferential unit 1 supplies at output through multiple busses 61 the value OMEGA.
We shall now discuss the operation of the fuzzy rule processing circuit 6 of FIG. 5 for parallel calculation of the degree of truth of four terms T of the antecedent part of a fuzzy rule.
The fuzzy rule processing circuit 6 receives at input sixteen fuzzy terms and must sort them correctly inside the related rules by means of the functional blocks which it includes.
The decoder block 3 acquires all the information COMP to constitute the data and supply the values:
RCOD: for sorting fuzzy terms on the rules,
COD: for selection of the exact fuzzy set among those contained in the fuzzy term transmitted, and
OPC: containing the code of the logical operators to be applied to the individual fuzzy sets.
The sorter block 4 sorts the sixteen fuzzy terms into. four sets of data rows (ROWi) on the basis of the information supplied by RCOD.
Finally, the selector block 5 extracts from the related fuzzy term the fuzzy set which appears as term T of the antecedent part of the rule R which the circuit is processing based upon the information contained in the signal COD.
The correct sequence of the membership functions contained in the terms T of the antecedent part of the rule R in question and of the operators OPC which link these terms are then supplied to the inferential unit 1 for the actual calculation of the values OMEGA.
Advantageously in accordance with the present invention this value OMEGA can represent the overall degrees of truth of four different rules or, as an alternative, the partial truth levels w of a rule R with more than four terms T in the antecedent part on the basis of which one can then calculate the overall degree of truth n of the rule R.
Having thus described at least one illustrative embodiment of the invention, various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description is by way of example only and is not intended as limiting. The invention is limited only as defined in the following claims and the equivalents thereto. | Method and apparatus of parallel processing of multiple inference rules organized in fuzzy sets or logical functions of multiple fuzzy sets including membership functions defined in a so-called universe of discourse. The inference rules are configured essentially as IF-THEN rules with at least one antecedent preposition and at least one consequent implication. The prepositions have at least one term of comparison between membership functions and a plurality of input data and each term is separated by logical operators. The method associates with the logical operators maximum and minimum operations among two or more elements and calculates exhaustively the overall degree of truth (Ω) of a rule with a maximum or minimum of N partial truth levels. The method is accomplished by a plurality of identical, parallel inferential processors. Each inferential processor determines a preposition or a partial truth level of a preposition. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates to an improved fence assembly having a retaining bar located within horizontal rails of a fence, the retaining bar not having fasteners to secure the horizontal rails of a fence to its vertical posts.
BACKGROUND OF THE INVENTION
[0002] Fences having intersecting vertical posts and horizontal rails have recently become popular and are strong, durable and attractive, while requiring little or no maintenance. In most fence designs, fences use fasteners, such as screws, to fix a plurality of horizontal to rails to a plurality of vertical posts. A disadvantage to these designs that use fasteners is that the fasteners often rust and corrode. Further, it is difficult to assemble fences using screws, as it is hard to tighten the screws in the rails to attach the rails to vertical posts. Moreover, if screws are used, then the fence cannot rotate, thus, making it difficult to set the fences on uneven surfaces.
[0003] There are various designs for fences having vertical posts and horizontal rails known in the prior art. U.S. Pat. No. 7,384,025 to Lo, U.S. Pat. No. 7,347,412 to Zhu and U.S. Pat. No. 6,173,944 to McCarthy all have screws engaging the coupling bars. While the screws are hidden in these designs, these designs suffer from having the screws rust and corrode, and these fence designs are difficult to assemble.
[0004] U.S. Pat. No. 5,454,548 to Moore is a fence design having a solid coupling bar with locking means that firmly locks the rails into pickets forming a rigid structure and thus not enabling any rotation of the rails with the pickets or posts. U.S. Pat. No 6,375,166 to Schall et al. uses inserts with legs for attachment; U.S. Pat. No. D479,612 to Larsen et al. and U.S. Pat. No. 6,969,051 to Gibbs use a locking rod; U.S. Pat. No. 7,021,607 to Alexander uses clips having flaps for attachment; and U.S. Pat. No. 6,752,386 to Bundy uses a sliding lockbar for attachment.
[0005] Another design, the Corigin™ system from Activeyards™ provides a system having horizontal rails and vertical posts where the rails are shown having a punched portion in the rails for connecting the horizontal rails to the vertical posts.
[0006] FIG. 23 shows a detailed cross-section view of the Corigin™ system that is known in the prior art. FIG. 23 provides horizontal rail 2320 , vertical post 2330 and retaining element 2340 having punched portion 2345 .
[0007] FIG. 23 further shows vertical post 2330 and retaining element 2340 being located within aperture 2310 of horizontal rail 2320 . Retaining element 2340 is shown located between upper support ridge 2360 , middle support ride 2365 and lower support ridge 2375 . These support ridges hold retaining element 2340 in place.
[0008] Furthermore, vertical post 2330 is shown having its sides abut upper support ridge 2350 and lower support ridge 2355 . Retaining element 2340 is shown engaging or being engageable with vertical post 2330 . Specifically, retaining element 2340 has a punched portion 2345 that is punched in and is engageable with an opening 2380 in vertical post 2330 . The engagement of the punched portion 2345 with hole 2380 allows vertical post 2330 to be engaged with horizontal rail 2320 .
[0009] FIG. 24 is a further view of the detailed cross-section view of FIG. 24 after being rotated along axis 24 - 24 . Here, punched portion 2345 is shown in hole 2380 . Vertical post 2330 is shown in aperture 2310 of horizontal rail 2320 .
[0010] The Corigin™ design, however, suffers from various deficiencies that are overcome by the present invention. The Corigin™ design cannot fully and freely rotate. Moreover, the Corigin™ design requires an extra step of punching holes in the retaining element, which makes it more difficult to manufacture as the punched portion needs to be lined up with the holes in the vertical posts during manufacturing. The Corigin™ design is exhibits greater wear and tear than the presently claimed invention and has less structural strength as the punched portions are subject to stresses that can cause the fence to deteriorate over time. Structural strength and integrity is important for fence design and the Corigin™ design has weak structural strength and integrity in this regard.
[0011] What is desired therefore is to provide a fence assembly and method that does not use fasteners and has a retaining bar in the assembly that allows for free and easy rotation of the vertical posts with respect to the horizontal rails. It is further desirable to develop a fence assembly and method that provides for rotation of the vertical posts with respect to the horizontal rails allowing for assembly of the fence on an uneven surface. It is further desirable to develop a fence assembly and method that allows for structural strength and integrity of all elements of the fence including the retaining bar. It is further desirable to provide a method for manufacturing a retaining bar for a fence that does not involve punching portions of the retaining bar, which weakens the structural strength and integrity of the bar.
SUMMARY OF THE INVENTION
[0012] Accordingly, it is an object of the present invention to provide a fence assembly that does not use fasteners and has a retaining bar in the assembly that allows for free rotation of the vertical posts with respect to the horizontal rails. It is a further object of the present invention to provide a fence assembly that provides for rotation of the vertical posts with respect to the horizontal rails allowing for assembly of the fence on an uneven surface.
[0013] It is a further object of the present invention to provide a fence assembly that has its retaining bar manufactured as one piece, rather than having the retaining bar require have punched portions that affect the overall strength and stability of the retaining bar. It is a further object of the present invention to provide a fence assembly and method that allows for structural strength and integrity of all elements of the fence including the retaining bar.
[0014] These and other objectives are achieved by providing a fence comprising: one or more horizontal rails, each of the one or more horizontal rails having one or more apertures extending through the one or more horizontal rails; one or more vertical posts, each of the one or more vertical posts passing through the one or more apertures, each of the one or more vertical posts having one or more openings and having one or more walls; one or more retaining elements, each of the one or more retaining elements having a ledge portion and a base portion, the ledge portion of the one or more retaining elements having one or more cavities, the one or more cavities dividing the ledge portion into one or more large sections and one or more smaller sections, the one or more larger sections being separated from the one or more smaller sections by the one or more cavities, wherein the one or more smaller sections are engaged with the one or more openings in the one or more vertical posts to secure the one or more vertical posts to the one or more horizontal rails.
[0015] In certain embodiments, the ledge portion of the one or more retaining elements is not continuous along the entire length of the one or more retaining elements. Rather the ledge portion is divided into pieces (one or more larger sections and smaller sections) allowing for the smaller sections it to interact with the one or more vertical posts.
[0016] In certain embodiments, the fence may include two upper support ridges and two lower support ridges located on each of the one of more horizontal rails. In other embodiments, only some of the one or more horizontal rails have two upper support ridges and two lower support ridges. In other embodiments, there may be just one upper support ridge, just two upper support ridges, or one upper support ridge and one lower support ridge, or two upper support ridges and one lower support ridge. Other combinations are possible whereby a middle ridge may be provided.
[0017] In some embodiments, the base portion of each of the one or more retaining elements extends vertically between one of the upper support ridges and one of the lower support ridges of each of the one or more horizontal rails to maintain the one or more retaining elements between one of the upper support ridges and one of the lower support ridges of each of the one or more horizontal rails. This allows for the retaining element to be secured within the one or more horizontal rails.
[0018] In some embodiments, the ledge portion of each of the one or more retaining elements extends horizontally away from the base portion of each of the one or more retaining elements. In other embodiments, the ledge portion may extend horizontally, but may be angled, so that it can engage with openings in the one or more vertical posts.
[0019] In certain embodiments, the two upper support ridges of each of the one or more horizontal rails are engageable with the one or more vertical posts. This allows the one or more vertical posts to be held in place by the two upper support ridges, and provides structural strength to the fence, preventing or mitigating the one or more vertical posts from rotating with respect to the one or more horizontal rails.
[0020] In certain embodiments, the one or more larger sections of the ledge portion of the one or more retaining elements prevent the one or more vertical posts from rotating once one of the one or more walls of the one or more vertical posts press against an edge of the one or more larger sections.
[0021] In other embodiments, the engagement of the one or more smaller sections with the one or more openings in the one or more vertical posts allows the fence to rotate. The fence can rotate up to 80 degrees though it is preferable for the fence to only rotate up to about 45 degrees. The rotation of the fence allows it to be efficiently installed on uneven surfaces.
[0022] In other embodiments, each of the one or more larger sections and each of the one or more smaller sections of the ledge portion of each of the one or more retaining elements has a rectangular shape. The one or more larger sections and the one or more smaller sections may have alternative shapes, such as squares, triangles, rectangles or trapezoids in other embodiments.
[0023] In certain embodiments, the fence may include each of the one or more horizontal rails having three sides and be U-shaped. In other embodiments, each of the one or more the vertical posts may have four sides and may have a rectangular shape. The openings in the one or more vertical posts may be circular or round. The fence may be modular and may be located on an uneven surface.
[0024] In certain embodiments, the one or more horizontal rails may engageable with a clip, the clip being engageable with a post.
[0025] Other objects of the invention are achieved by providing a retaining element for a fence comprising: a base portion that extends vertically; and a ledge portion that extends horizontally, the ledge portion having one or more cavities, the one or more cavities dividing the ledge portion into one or more larger sections and one or more smaller sections, the one or more larger sections being separated from the one or more smaller sections by the one or more cavities, wherein at least one of the one or more smaller sections is engageable with an opening in a component of the fence. Here, the ledge portion of the retaining element is not continuous along the entire length of the retaining element.
[0026] In certain embodiments, the one or more larger sections prevent the fence from rotating once a wall of a vertical post of the fence presses against an edge of the one or more of larger sections of the ledge portion of the retaining element.
[0027] In certain embodiments, each of the one or more small sections and the one or more larger sections of the ledge portion of the retaining element has a rectangular shape.
[0028] In certain embodiments, the base portion has a greater thickness at the bottom of the base portion than at the top of the base portion. The base portion may sit or be engageable with a lower support ridge of a horizontal rail.
[0029] In certain embodiments, the base portion may extend between an upper support ridge and a lower support ridge of a horizontal rail to attach the retaining element to the horizontal rail.
[0030] Other objects of the invention are achieved by providing a method of manufacturing a retaining element for a modular fence comprising the steps of: providing a retaining element comprising a base portion, the base portion extending vertically and the ledge portion extending horizontally away from the base portion; and machining cavities in the ledge portion, so that the ledge portion is divided into individual sections, the individual sections composed of alternating larger sections and smaller sections.
[0031] The method may have the alternating larger sections and smaller sections be equidistant from one another. The retaining element may be made from a single piece of material.
[0032] Other embodiments may have the ledge portion welded onto the base portion. This embodiment may have the retaining element manufactured without machining the retaining element, but rather may only involve steps of welding the ledge portion onto the base portion.
[0033] Other objects of the invention are achieved by providing a method of installation of a modular fence comprising the steps of: providing one or more one or more horizontal rails, each of the one or more horizontal rails having one or more apertures extending through the one or more horizontal rails; providing one or more vertical posts, each the one or more vertical posts having one or more openings; providing one or more retaining elements, each of the one or more retaining elements having a ledge portion and base portion, the ledge portion of the one or more retaining elements having one or more cavities, the one or more cavities dividing the ledge portion of the one or more retaining elements into one or more larger sections and one or more smaller sections, the one or more larger sections being separated from the one or more smaller sections by the one or more cavities; disposing each of the one or more vertical posts through one of the apertures extending through the one or more horizontal rails; disposing the one or more retaining elements within the one or more horizontal rails; and engaging the one or more small sections of the ledge portion of the one or more retaining elements with the one or more openings in the one or more vertical posts to secure the one or more vertical posts to the one or more horizontal rails.
[0034] The method may involve each of the one or more horizontal rails having two upper support ridges and two lower support ridges, where the base portion of each of the one or more retaining elements extends between the upper support ridges and the lower support ridges of the one or more horizontal rails to maintain the one or more retaining elements between one of the upper support ridges and one of the lower support ridges of each of the one or more horizontal rails.
[0035] Other embodiments involve the fence being installed on an uneven surface.
[0036] Other embodiments involve a step of further rotating the one or more vertical posts with respect to the one or more horizontal rails until the one or more horizontal rails are parallel to the surface.
[0037] Other embodiments involve the steps of providing a clip and two posts; engaging the one or more horizontal rails with the clip; and engaging the clip with the post to provide structural support to the fence.
[0038] Other objects of the invention and its particular features and advantages will become more apparent from consideration of the following drawings and accompanying detailed description. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] FIG. 1 is a perspective view of a fence of an embodiment of the present invention;
[0040] FIG. 2 is a perspective view of a horizontal rail of the embodiment of the present invention shown in FIG. 1 ;
[0041] FIG. 3 is a top view of the horizontal rail of FIG. 2 ;
[0042] FIG. 4 is a bottom view of the horizontal rail of FIG. 2 ;
[0043] FIG. 5 is a side view of the horizontal rail of FIG. 2 ;
[0044] FIG. 6 is a perspective view of a vertical post of the embodiment of the present invention shown in FIG. 1 ;
[0045] FIG. 7 is a side view of the vertical post of FIG. 6 ;
[0046] FIG. 8 is top view of the vertical post of FIG. 6 ;
[0047] FIG. 9 is a perspective view of a retaining element of the embodiment of the present invention shown in FIG. 1 ;
[0048] FIG. 10 is a detailed side view of the retaining element of FIG. 9 ;
[0049] FIG. 11 is a top view of the retaining element of FIG. 9 ;
[0050] FIG. 12 is a side view of the retaining element of FIG. 9 ;
[0051] FIG. 13 is a detailed side view of the horizontal rail and vertical post of the embodiment of the present invention shown in FIG. 1 ;
[0052] FIG. 14 is a top view of the horizontal rail and vertical post of FIG. 13 ;
[0053] FIG. 15 is a detailed cross-section view of the horizontal rail, vertical post and retaining element assembly of the embodiment of the present invention shown in FIG. 1 ;
[0054] FIG. 16 is a detailed cross-section view of the horizontal rail, vertical post and retaining element assembly of FIG. 15 after being rotated;
[0055] FIG. 17 is a top detailed cross-section view of the horizontal rail, vertical post and retaining element assembly of FIG. 15 ;
[0056] FIG. 18 is a detailed cross-section view of the horizontal rail, vertical post and retaining element assembly of FIG. 16 ;
[0057] FIG. 19 is a detailed cross-section view of the horizontal rail, vertical post and retaining element assembly of FIG. 18 where the vertical post is rotated;
[0058] FIG. 20 is a detailed cross-section view of the horizontal rail, vertical post and retaining element assembly of FIG. 18 where the vertical post is rotated until its side hits the edge of the larger section of the retaining element;
[0059] FIG. 21 is a perspective view of the horizontal rail and clip of the embodiment of the present invention shown in FIG. 1 ;
[0060] FIG. 22 is a perspective view of various modules of a fence of the present invention;
[0061] FIG. 23 is a detailed cross-section view of the horizontal rail, vertical post and retaining element assembly of the prior art Corigin™ design; and
[0062] FIG. 24 is a detailed cross-section view of the horizontal rail, vertical post and retaining element assembly of the prior art Corigin™ design after being rotated.
DETAILED DESCRIPTION OF THE INVENTION
[0063] Referring to FIG. 1 , a fence assembly 100 in accordance with the present invention is shown. The fence assembly 100 has vertical posts 130 shown and horizontal rails 120 , 120 ′ and 120 .″ Also shown are end posts 105 and 110 . The assembly may have a greater number or a small number of horizontal rails and/or vertical posts than shown in FIG. 1 .
[0064] FIG. 2 is a perspective view of horizontal rail 120 of FIG. 1 . FIG. 2 shows horizontal rail 120 having top surface 200 , which is divided into sections 220 and 220 ′ by apertures 210 and 210 ′ extending through horizontal rail 120 . Also shown are side surface 230 and the internal components of the rail. Upper support ridges 250 and 260 and lower support ridges 255 and 265 are shown in FIG. 2 . These support ridges are shown extending horizontally or into the center of the interior of horizontal rail 120 .
[0065] FIGS. 3-5 show other views of horizontal rail 120 . Shown in these figures are apertures 210 and 210 ′, although additional apertures may be present in a horizontal rail. Also shown is the bottom surface 300 of the horizontal rail 120 , which is divided into sections 320 and 320 ′ by apertures 210 and 210 ′ extending through horizontal rail 120 . Also shown is a side view of horizontal rail 120 , side faces 225 / 230 and top face 500 .
[0066] FIG. 6 is a perspective view of vertical post 130 . Vertical post 130 is shown having side surfaces 610 , 620 and two other surfaces which are not numbered. The top of the vertical post is shown having sides 650 , 660 , 670 and 680 . Also openings 690 and 690 ′ are shown. These openings are shown being circular, although the openings may be other shapes such as being round, rectangular, oval, pentagonal, or may be additional shapes.
[0067] FIGS. 7 and 8 shown front surface 610 with openings 690 and 690 ′ as well as a top view of the vertical post 130 .
[0068] FIG. 9 is a perspective view of retaining element 900 of an embodiment of the invention. FIG. 9 shows base portion 930 and ledge portions 910 , 910 ′, 910 ″, 920 and 920 ′. The ledge portions 910 , 910 ′, 910 ″ are the larger portions and 920 and 920 ′ are the small portions of the ledge section. A greater or smaller number of ledge portions may be provided for the retaining bar than shown in FIG. 9 .
[0069] Base portion 930 is shown being vertical. Ledge portions 910 , 910 ′, 910 ″, 920 and 920 ′ are shown extending horizontally from the base portion 930 . In FIG. 12 , base portion 930 is shown being angled and having a greater thickness at the bottom of the base portion than at the top. However, the base portion 930 may not be angled in certain embodiments. The ledge portions may be shown either angled up or down, but still extending away from the base portion.
[0070] FIG. 13 is a detailed view of horizontal rails 120 , 120 ′ and vertical posts 130 , 130 ′ in an assembled state. Here, it is shown that the vertical posts 130 , 130 ′ are located within horizontal rails 120 , 120 ′. This is further shown in FIG. 14 where vertical posts 130 , 130 ′ are located with apertures 210 , 210 ′ of the horizontal rail 120 . The top surface 220 , 220 ′ and 220 ″ is also shown in this figure.
[0071] FIG. 15 shows a detailed cross-section view of horizontal rail 120 , vertical post 130 and retaining element 900 of an embodiment of the present invention shown in FIG. 1 . Here, vertical post 130 and retaining element 900 are shown being located within aperture 210 of the horizontal rail 120 . Retaining element 900 is shown located between upper support ridge 260 and lower support ridge 265 . These support ridges hold or maintain the retaining element 900 in place.
[0072] Furthermore, vertical post 130 is shown having its sides abut upper support ridge 250 and lower support ridge 255 . Retaining element 900 is shown engaging or being engageable with vertical post 130 . Specifically, the ledge portion 920 is engageable with opening 690 in vertical post 130 .
[0073] FIG. 16 is a further view of the detailed cross-section view of FIG. 15 after being rotated. Here, ledge portions 910 , 910 ′ and 920 are shown. Ledge portion 920 is shown being located within opening 690 . The edges of ledge portion 920 are shown abutting against opening 690 , however, enough space is left so that vertical post 130 can rotate.
[0074] FIG. 17 is a top detailed cross-section view of FIG. 15 . Here, the side surfaces 610 , 620 , 630 and 640 are shown as well as ledge portions 910 , 910 ′ and 920 , retaining element 900 and the sides 225 , 230 of horizontal rail 120 .
[0075] FIG. 17 shows how ledge portion 920 is located within opening 690 . Ledge portions 910 and 910 ′ are also shown in this figure.
[0076] FIGS. 18-19 show the rotation of vertical post 130 within horizontal rail 120 . FIG. 18 shows vertical post 130 being perpendicular to horizontal rail 120 . FIG. 19 shows vertical post 130 being rotated away from being perpendicular to horizontal rail 120 . FIGS. 18-19 also show the face 610 of vertical post 130 as well as other elements previously described in other figures. Allowing for the vertical post 130 to rotate with respect to horizontal rail 120 is one of the objects of the invention as it allows the fence to rest on uneven surfaces. Moreover, such rotation is free and easy, through providing an advantage during assembly.
[0077] FIG. 20 shows vertical post 130 being rotated away from being perpendicular to horizontal rail 120 until the side of vertical post 610 hits the edge of ledge portion 910 . This stops the vertical post from being further rotated. In certain embodiments, the amount of rotation of vertical post varies, but is not more than eighty degrees.
[0078] FIG. 22 is a perspective view of the horizontal rail 2200 . Horizontal rail 2200 is shown having upper support ridges 2250 and 2260 and being connected to clip 2210 . Clip 2210 has an indent 2225 and vertical opening 2215 to allow a stake (not shown) to be inserted vertically through vertical opening 2115 .
[0079] The clip 2210 is connected to horizontal rail 2200 through a barb 2220 , which fits into bore 2230 on the horizontal rail 2200 .
[0080] FIG. 21 shows fence sections 2110 , 2110 ′, 2110 ″ and 2110 ′″, which are located on uneven surface 2150 . The fence sections are modular and have stakes in between each modular section.
[0081] While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation and that various changes and modifications in form and details can be made thereto, and the scope of the appended claims should be construed as broadly as the prior art will permit.
[0082] The description of the invention is merely exemplary in nature, and thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention. | An improved fence assembly and method of manufacture and assembly of a fence that does not require fasteners. The fence assembly and method includes a retaining element that does not use fasteners and allows the vertical posts of the fence to rotate with respect to the horizontal rails of the fence, so that the fence can be installed on an uneven surface. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The control of sand production in a well is a problem that has been with the oil industry for a very long time. Experience indicates that sanding problems are directly related to production rates of the well. Therefore, the problem of sanding has become more critical lately since proration control by the government has been substantially eliminated due to shortages. Consequently, the oil companies are concerned with substantially increasing production of their wells. In fact, the government is actually requiring an increase of production in Federal waters. It is therefore apparent that oil producing companies would like to know the maximum rate at which they can produce without sanding from wells in which no consolidation or gravelpack has been used. Furthermore, oil companies would be very interested in knowing which wells require gravelpacking or consolidation from the very beginning of production, so that control measures can be instituted from the start. Since there are friable sand reservoirs in known sand producing areas from which economically attractive production rates may be obtained without the use of any form of sand control, it is desirable that some means for distinguishing or predicting those competent sand formations from incompetent sand formations be available so that sand controlling techniques such as gravelpacking or plasticizing may be avoided when unnecessary, or, on the other hand, may be resorted to before sanding problems develop from over production in those formations where such sand control is necessary.
2. Description of the Prior Art
In seeking information concerning zones bearing hydrocarbons such as oil and gas that may exist in subsurface earth formations adjacent a borehole drilled into these formations, various types of exploring devices are typically lowered into the borehole for measuring selective properties of the formations adjacent the borehole. Three principal types of such exploring devices are (a) electrical exploring devices (using either electrodes or induction coils), (b) sonic exploring devices, and (c) radioactivity exploring devices.
The electrical exploring devices measure the electrical resistivity or conductivity of the earth formations. Such electrical resistivity is determined primarily by the amount, distribution and resistivity of the fluids contained in the formation core spaces. The sonic exploring devices, on the other hand, measure the time required for sonic waves to travel across a given span of the earth formation which is related to the sonic velocity of the formation. This sonic velocity is determined primarily by the nature of the rock matrix and particularly its porosity, the state of confining stress and the type of fluid in the pore space.
The radioactivity exploring devices measure either the natural radioactivity of the formation or the radioactivity induced therein by bombardment of the formation with radioactivity particles or rays. Two particular radioactivity exploring devices used to investigate formations are the formations density logging tool and the neutron logging tool. The formation density logging tool emits gamma rays which are diffused through the formation and the number of diffused gamma rays reaching one or more nearby detectors are counted to provide a measure of the electron density of the adjacent formation. Moreover, it is known that this electron density is very closely proportional to the bulk density of the formation in substantially all cases.
The neutron tool, on the other hand, utilizes a source for emitting neutrons into adjacent formations. In one form of neutron device, these neutrons lose energy by collision with atoms of the formation. When the energy level of these neutrons is reduced to the epithermal energy range, they can be detected by a nearby detector which counts the number of epithermal neutrons. Since hydrogen atoms are the only ones whose weights are almost equal to that of the neutron, they are the most effective in reducing the energy level of the neutrons to enable their capture. Thus, it can be said that this type of neutron log is essentially a record of the hydrogen atom density of the rocks surrounding the borehole. Since the formation pore spaces are generally filled with water or fluid hydrocarbon, both of which have about the same amount of hydrogen, a neutron log does not distinghish between oil and water, but is primarily affected by the formation porosity. Gas, on the other hand, will alter this porosity determination by the neutron log.
In general, none of the electrical, acoustic, or radioactivity measurements taken alone give all of the required information concerning the hydrocarbons in the formations or the characteristics of those formations. The various factors which affect each measurement are taken into account and then an interpretation or deduction is made as to the probable characteristics of the formations.
There is considerable experimental evidence which indicates that there is a correlation between the intrinsic strength of a formation and the dynamic elastic constants of the formation as determined from sonic velocity and density measurements. One technique which attempts to predict the competency of sand and thereby also predict the maximum rate at which a well may be produced is described in a paper, "Estimation of Maximum Production Rates from Friable Sandstones Without Using Sand Control Measures", by N. Stein and V. W. Hilchie, Paper No. SPE 3499 published by the American Institute of Mining, Metallurgical and Petroleum Engineers Inc. Copyright 1971. According to this paper, the shear modulus is the most important elastic constant for predicting sanding problems, however, the technique described in the paper is based on the assmmption that the bulk modulus is constant throughout the formation. In general, the bulk modulus varies throughout the formation and this technique would not provide accurate results.
It is possible to obtain the mechanical properties or elastic constants of the formation, such as the shear modulus and bulk modulus (or bulk compressibility) from the value of Poisson's Ratio. Heretofore Poisson's ratio was determined from the sonic shear and compressional velocities, while the sonic compressional velocity which is generally referred to as the acoustic travel time of the formation is readily measured as described above, the sonic shear velocity, is highly attenuated. The sonic shear velocity approaches the velocity of the fluid in the formation, and shear arrivals are often masked in the sonic wave trains making it extremely difficult to measure.
Clearly a need exists for readily determining values for Poisson's ratio which can then be used to determine the mechanical properties and strength of a formation.
SUMMARY OF THE INVENTION
In accordance with the invention, well-logging measurements are combined to produce a parameter indicative of the shaliness of the formation, which is referred to as the shale index. The shale index is then used to compute Poisson's ratio. The invention can be carried out using an approximately programmed general purpose digital computer or a special purpose analog computer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an investigating apparatus suspended in a borehole for deriving a plurality of well-logging measurements and a schematic representation of apparatus for processing these well-logging measurements;
FIGS. 2 and 3 are diagramatic representations of computer program flow charts for carrying out the invention utilizing a general purpose digital computer;
FIG. 4 is a diagramatic representation of a special purpose analog computer for practicing the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there is shown an investigating apparatus 10 located in a borehole 12 on the end of multiconductor cable 14 which is raised and lowered in borehole 12 drilled into earth formation 16 by a suitable winch mechanism (not shown). Investigating apparatus 10 includes exploring devices for obtaining measurements of the acoustic travel time Δ t, bulk density ρ b , deep and shallow resistivities, R xo and R t , spontaneous potential SP, porosity, φ n , derived from a neutron exploring device and the natural gamma ray count, GR, of the formation.
Measurement signals derived from the exploring device 10 are transmitted to the suitable signal processing circuits 20 at the surface of the earth. The signal processing circuits convert the well-logging signals to digital form for temporary storage by way of a digital tape recorder 22 for application to a computer 24 which is programmed in accordance with the teachings of the present invention to process the data in a manner to provide valuable information relative to the nature of the earth formations. It should be appreciated at this point that the digital computer 24 could either be a truck mounted computer for operation at the well site, or the data could be transmitted via a telephone communication or other technique to a computer located some distance away. If the data was recorded on a magnetic tape by way of tape recorder 22, of course, the tape containing the data could be simply directly transported to the distant computer for processing. While the measurements to be used in practicing the present invention are shown in FIG. 1 as having been derived from one exploring device, it should also be understood that these measurements could be derived from a plurality of exploring devices which are run through the borehole at different times. In this event, the data from each run would be recorded on individual magnetic tapes and the total data would then be merged for use by digital computer 24. Such merging may preferably be accomplished by merging all of the data on a single tape for processing by the digital computer. Alternatively, the data could be processed using a special purpose analog computer.
An acoustic exploring device for deriving a measurement for Δ t can be found in U.S. Pat. No. 3,231,041 granted to F. P. Kokesh on Jan. 25, 1966. An exploring device for obtaining the measure of the bulk density can be found in U.S. Pat. No. 3,321,625 granted May 23, 1967 to John F. Wall. An exploring device for obtaining resistivity measurements and measurements of the spontaneous potential can be found in U.S. Pat. No. 3,053,530 granted to G. Attali on July 1, 1969. An example of an exploring device for obtaining a neutron porosity log measurement can be found in U.S. Pat. No. 2,769,918 granted to C. W. Tittle on Nov. 6, 1956.
The neutron tool responds to the amount of hydrogen in the formation, and is essentially a record of the hydrogen atom density in the rocks surrounding the borehole. Liquid hydrocarbons have hydrogen indexes close to that of water and neutron measurements in these formations are primarily affected by porosity. Gas, however, usually has a considerably lower hydrogen concentration which varies with temperature and pressure. Therefore, when gas is present near enough to the borehole to be within its zone of investigation, a neutron log does not provide an accurate measure of formation porosity.
In addition to deriving a measure of formation porosity from the neutron tool, the bulk density and acoustic travel time measurements can also be converted to measurements of formation porosity. The bulk density measurement can be converted to a porosity measurement if the matrix density ρ m and fluid densities ρ f are known. The equation for converting this bulk density measurement to a porosity measurement is: ##EQU1## See pages 43 and 44, "Log Interpretation Principles," published by Schlumberger Limited, New York, New York 10017 which is incorporated herein by reference. Common values of ρ m for various formations are:
2.71 for limestone
2.87 for dolmite
In water sands, the fluid density ρ f is usually set equal to 1. However, in light hydrocarbon and gas bearing formations, the fluid density ρ f will be less than one, and thus the value of porosity φ D derived from the density tool will be higher than the true porosity.
The acoustic travel time Δ t can also be converted to a measure of porosity provided the acoustic travel time of the rock matrix and fluid, Δt m and Δt f respectively are also known. The relationship of the acoustic or sonic derived porosity in terms of Δ t is: ##EQU2## See pages 36 and 37, "Log Interpretation Principles", heretofore mentioned.
The spontaneous potential measurement provided by the exploring apparatus 10 is the difference between the potential of an electrode on the exploring device and the potential of an electrode located at the surface of the earth. Opposite shale formation, spontaneous potential will usually remain fairly constant and thus tend to follow a straight line on the log, called the "Shale Base Line". Opposite permeable formations a spontaneous potential will show excursions from the shale base line. In thick permeable beds free of shale, the spontaneous potential will also reach an essentially constant value defined as the "Sand Line". For further information concerning the spontaneous potential measurement and its uses, see pages 7-12 of the referenced publication "Log Interpretation Principles".
In accordance with a copending patent application entitled Method and Apparatus for Investigating Subsurface Earth Formations, filed by Anderson et al on Oct. 5, 1973, Ser. No. 403,786, elastic constants or elastic modulii of the formation are computed using Poisson's ratio which, in turn, provide useful information regarding the strength of the formation.
Heretofore, Poisson's ratio could be determined in accordance with: ##EQU3## where: ν = Poisson's ratio
V s = sonic shear velocity
V c = sonic compressional velocity
and used to determine the elastic constants. In practice, this method did not yield reliable or accurate results owing to the difficulty in determining the sonic shear velocity.
After detailed investigation and experimentation, it has been found that the Poisson's ratio can be related to the shale content or shaliness of the formation according to the following equation:
ν = 0.125q + 0.27 (4)
where q is the shaliness index defined as: ##EQU4## where φ z is the total space between the matrix grains supporting the overburden, and φ e is the porosity available to water and hydrocarbons. The difference, φ z - φe, is interpreted as the intergranular space occupied by dispersed shale and fine in sands.
As discussed below, to arrive at values for φ z and φ e in the presence of hydrocarbons, a complete analysis of the formation is required. When hydrocarbons are not present, φ z is equal to the sonic porosity φ S , φ e is equal to the density porosity φ D and Eq. 5 can be written as: ##EQU5##
By using the results of equation (4), the elastic constants, bulk compressibility and shear modulus can be determined in accordance with the techniques disclosed in the above referenced Anderson et al copending application.
To obtain the value of Poisson's ratio it is therefore only necessary to determine the value of the shaliness index. In the presence of hydrocarbons this requires a complete analysis of the formation. A technique for obtaining the value of the shaliness index is set forth in detail in U.S. Pat. No. 3,638,484 issued on Feb. 1, 1972 to Tixier and assiged to Schlumberger Technology Corporation, and in a paper entitled "Log Evaluation of Low-Resistivity Pay Sands in the Gulf Coast" by M. P. Tixier, R. L. Morris and J. G. Connell, presented at the SPWLA Ninth Annual Logging Symposium, June 23rd-26th, 1968. Another technique is set forth in a publication entitled "Log Analysis of Sand-Shale Sequence -- A Systematic Approach", by Poupon et al, published in the July, 1970 issue of the Journal of Petroleum Technology where the shaliness index is V sh .
By utilizing the techniques fully explained in the Tixier patent and Tixier et al publication, values for φ e , φ z , q, C p , the sonic compaction factor and S gxo the gas saturation near the borehole wall are obtained for each depth level in the formation. Since these techniques are fully explained in the above referenced patent and publication, they will not be discussed in detail herein.
The values of q at each depth level thus obtained are then utilized, in equation 4 to compute Poisson's ratio.
Referring now to FIG. 2, there is shown a flow diagram for implementing this invention through the use of an appropriately programmed digital computer. Poisson's ratio is computed by running two sweeps through the data. The first sweep is used to obtain values for q at each depth level using the techniques of the above-referenced Tixier patent. This value is then used in a second sweep to compute the value of Poisson's ratio for each depth level. The output of the program can be a listing of q and Poisson's ratio computed for each depth level or a log showing the continuous variation of these parameters as a function of depth.
The first sweep of the program is entered, block 30, and the data derived from the well-logging tool is read on a level-by-level basis, block 32. Values for q are computed for each depth level, block 34, using the techniques disclosed in the referenced Tixier patent and the first sweep ends, block 36.
Sweep 2 is shown in FIG. 3. The sweep is entered, via block 40, after which the input parameter for the first depth level, q, computed in sweep 1 is read, block 42. Next, Poisson's ratio is computed using equation 4, block 44. If this is not the last depth level, NO answer from decision element 46, the depth level is incremented by one, block 54, the program returns to block 42 to analyze the next depth level. When all the depth levels have been analyzed, YES answer from decision element 46, values for q and Poisson's ratio are printed out for each depth level in the borehole, block 48. If a continuous log is required, YES answer from decision element 50, the log is printed out, as represented by block 52, and in either case, the program exits block 62.
Referring now to FIG. 4, there is shown a special purpose analog computer for carrying out the invention. It will be understood that prior to utilizing the analog computer shown in FIG. 4, the well-logging data derived from the borehole is processed in accordance with the techniques of the Tixier U.S. Pat. No. 3,638,484 to provide values for q, for each depth level of the formation and that these values are stored on magnetic tape for playback on tape recorder playback 70.
The value of q computed during the prior computation is applied from tape recorder playback 70 to Poisson Ratio Computer 72 which contains conventional circuits for computing the value of Poisson's ratio in accordance with the equation 4. As shown in greater detail in FIG. 6, the value of q is first applied to a multiply circuit 74 where it is multiplied by a signal proportional to a constant 0.125. The resultant product, 0.125q, is added to a signal proprotional to 0.27 in addition circuit 76 to produce the signal 0.125q + 0.27 which is equal to Poisson Ratio.
The computed values of Poisson's ratio and q are applied to a recorder 78 which produces a continuous recording of the variables as a function of depth. The recorder is controlled by a signal from the tape recorder playback to insure that its operation is synchronized with the tape recorder drives.
While there have been described what are at present considered to be preferred embodiments of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is, therefore, intended to cover all such changes and modifications as fall within the true spirit and scope of the invention. | In accordance with illustrative embodiments of the present invention, measurements of a plurality of earth formation parameters are combined in a new manner to establish Poisson's ratio for the formations surrounding a borehole which is useful for identifying mechanically competent formations. | 4 |
STATEMENT AS TO FEDERALLY SPONSORED RESEARCH
The invention described herein was supported in whole or in part by Grant No. DE07652 from the National Institutes of Health, which have certain rights in the invention.
BACKGROUND OF THE INVENTION
The invention relates to antifingal and antibacterial peptides.
Bacterial and fungal infections are prevalent and, in some cases, life-threatening conditions that affect otherwise healthy patients. Bacterial and fungal infections are especially dangerous for immuno-compromised patients. For these patients, systemic fungal infections can lead to death, since there are few safe and effective antifungal pharmaceuticals for intravenous use. Similarly, infections with various bacterial species can cause sever disease states and even death.
Although several antifungal agents (e.g., clotrimazole, miconazole, ketoconazole, and nystatin) and antibacterial agents (e.g., penicillin, streptomycin, tetracycline, and chlorhexidine) are currently available, these agents are not completely effective. These agents can also lead to drug resistant organisms and can produce adverse side effects. In addition, many are not appropriate for oral or systemic administration.
SUMMARY OF THE INVENTION
The invention features substantially pure peptides containing between 13 and 20 amino acids, inclusive; the peptides have the amino acid sequence: R1-R2-R3-R4-R5-R6-R7-R8-R9-R10-R11-R12-R13-R14-R15-R16-R17-R18-R19-R20-R21-R22-R23, where R1 is Asp or is absent; R2 is Ser or is absent; R3 is His or is absent; R4 is Ala; R5 is Lys, Gln, Arg, or another basic amino acid; R6 is Arg, Gln, Lys, or another basic amino acid; R7 is His, Phe, Tyr, Leu, or another hydrophobic amino acid; R8 is His, Phe, Tyr, Leu, or another hydrophobic amino acid; R9 is Gly, Lys, Arg, or another basic amino acid; R10 is Tyr; R11 is Lys, His, Phe, or another hydrophobic amino acid; R12 is Arg, Gln, Lys, or another basic amino acid; R13 is Lys, Gln, Arg, another basic amino acid, or is absent; R14 is Phe or is absent; R15 is His, Phe, Tyr, Leu, another hydrophobic amino acid, or is absent; R16 is Glu or is absent; R17 is Lys or is absent; R18 is His or is absent; R19 is His or is absent; R20 is Ser or is absent; R21 is His or is absent; R22 is Arg or is absent; and R23 is Gly or is absent; where Gln cannot simultaneously occupy positions R5, R6, R12, and R13 of the amino acid sequence of a peptide.
In preferred peptides, at least one of R7, R8, R11, and R15 is Phe; R9 is Lys; R11 is His; or at least one of R7, R8, and R15 is Tyr; or any combination of these substitutions is present in the peptide. In other preferred peptides, R1, R2, and R3 are absent; alternatively, R22 and R23 are absent; R20, R21, R22, and R23 are absent; or R18, R19, R20, R21, R22, and R23 are absent.
The peptides may have substituents bonded to either terminus of the peptide. For example, the peptide may have an acetyl or a carbamyl addition at the N-terminus, and/or an amide addition at the C-terminus.
Preferred peptides contain 13-16 amino acids, and more preferably contain 13-14 amino acids. The invention further features pharmaceutical compositions including the peptides of the invention.
The peptides of the present invention have potent antibacterial and antifungal properties, and the invention also features methods for treating bacterial and fungal infections using these peptides.
Other features and advantages of the invention will be apparent from the following description and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the amino acid sequence of histatin 3.
DETAILED DESCRIPTION OF THE INVENTION
The invention features peptides containing 13 to 20 amino acids; these peptides include defined portions of the amino acid sequence of the naturally occurring protein histatin 3 (SEQ ID NO: 1), which is shown in FIG. 1 . In addition, the peptides of the invention include defined portions of the amino acid sequence of histatin 3, with amino acid substitutions at particular positions of the peptides. These peptides are referred to herein as “histatin-based peptides.”
Histatins (also referred to in the literature as histidine-rich proteins or HRPs) are salivary proteins that are synthesized in the parotid and submandibular-sublingual secretory glands of humans and Old World monkeys and are believed to be part of the extraimmunologic defense system of the oral cavity. The family of naturally occurring human histatins is a group of twelve low molecular weight peptides. The major family members, which make up 70-80% of the whole family, are histatins 1, 3, and 5, containing 38, 32, and 24 amino acid residues, respectively.
Preparation of the Peptides
The peptides of the present invention can thus be obtained from naturally occurring sources of histatin; alternatively, they can be obtained by recombinant DNA techniques as expression products from cellular sources. The peptides can also be chemically synthesized.
For example, cloned DNA encoding the histatins may be obtained as described by L. M. Sabatini et al., Biochem. Biophys. Res. Comm. 160: 495-502 (1989) and J. C. Vanderspek et al., Arch. Oral Biol. 35(2): 137-43 (1990). cDNA encoding the histatin-based peptides can be cloned by recombinant DNA techniques, for instance, by using degenerate oligonucleotides based on the amino acid sequence of histatin-based peptides as primers for polymerase chain reaction amplification.
Alternatively, oligonucleotides encoding histatins or histatin-based peptides can be synthesized chemically using commercially available equipment. They can then be made double-stranded and cloned into vectors for amplification in prokaryotic or eukaryotic host cells.
Histatin-based peptides can be produced in a variety of expression vector/host systems, which are available commercially or can be reproduced according to recombinant DNA and cell culture techniques. The vector/host expression systems can be prokaryotic or eukaryotic, and can include bacterial, yeast, insect, mammalian, and viral expression systems. The construction of expression vectors encoding histatin-based peptides, transfer of the vectors into various host cells, and production of peptides from transformed host cells can be accomplished using genetic engineering techniques, as described in manuals such as J. Sambrook et al., Molecular Cloning (2d ed. 1989) and Current Protocols in Molecular Biology, (F. M. Ausubel et al., eds.).
Modified histatin-based peptides can also be produced from cloned DNAs containing mutated nucleotide sequences. Histatin-based peptides encoded by expression vectors may be modified due to post-translational processing in a particular expression vector/host cell system.
These peptides can be altered by minor chemical modifications, such as by adding small substituents or by modifying one or more of the covalent bonds within or between the amino acid residues. The substituent groups can be bulky and may include one or more natural or modified amino acids. Useful modifications include the addition of a substituent to either the amino terminus, the carboxyl terminus, or to both ends of the peptide. A combination of additions at both termini is especially useful. Particularly useful modifications include acetylation or carbamylation of the amino terminus of the peptide, or amidation of the carboxyl terminus of the peptide. These alterations do not significantly diminish the antifungal or antibacterial activities of the peptides and appear to stabilize the peptide in its active form and to aid in the prevention of enzymatic degradation of these peptides.
Antifungal and Antibacterial Activities of Histatin-Based Peptides
The antifungal activity of the naturally-occurring histatins, as well as their inhibitory effect on several oral bacteria (such as the cariogenic Streptococcus mutans and the periodontal pathogen Porphyromonas gingivalis ), have been demonstrated in vitro. In addition, the observation that polyhistidine peptides inactivate the herpes simplex virus in vitro and that whole saliva contains inhibitors of the human immunodeficiency virus suggests the possibility that histatins may have anti-viral activity. These in vitro studies support the potential clinical use of compositions containing histatin-based peptides for the treatment of local and systemic candidal infection, oral bacterial diseases such as caries and periodontal disease, systemic bacterial infection, and viral infection.
The antifungal activities of the histatin-based peptides can be measured in assays for killing Candida albicans blastoconidia (as described in T. Xu et al., Infect. Immun. 59(8): 2549-2554 (1991)). The antibacterial activities of the histatin-based peptides can be measured in assays for inhibition of P. gingivalis growth. Histatin-based peptides can also interfere with bacterial virulence by inhibiting hemagglutination caused by B. forsythus and P. gingivalis and by inhibiting proteases such as clostripain; assays that measure these inhibitory activities are therefore useful in measuring the antibacterial activities of histatin-based peptides as well.
The antifungal and antibacterial properties of the histatin-based peptides are a function of both the size and the amino acid sequence of the respective peptides. Peptides having amino acid sequences shorter than those of the naturally-occurring histatins can have antibacterial and antifingal properties that are superior to those of the naturally-occurring histatins, particularly when these properties are measured on a weight basis.
Some of the peptides of the present invention include part of the amino acid sequence:
Asp-Ser-His-Ala-Lys-Arg-His-His-Gly-Tyr-Lys-Arg-Lys-Phe-His-Glu-Lys
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
His-His-Ser-His-Arg-Gly (SEQ ID NO:2).
18 19 20 21 22 23
Alternatively, the peptides of the present invention can include portions of this sequence with amino acid substitutions at one or more positions. Preferred peptides include those in which the glycine at position 9 is replaced by lysine, arginine, or another basic amino acid; the lysine at position 11 is replaced by histidine, phenylalanine or another hydrophobic amino acid; one or more of the histidines at positions 7, 8, and 15 is replaced by phenylalanine, tyrosine, leucine, or another hydrophobic amino acid; one or both of the lysines at positions 5 and 13 is replaced by arginine or another basic amino acid; or one or both of the arginines at positions 6 and 12 is replaced by lysine or another basic amino acid. Combinations of these amino acid replacements can be used as well.
The amino acid substitutions result in peptides that display enhanced antifungal activity in comparison to peptides including the native sequence. For example, the replacement of histidine at positions 7, 8, or 15 with phenylalanine, either singly or in combination, results in peptides with increased antifungal activities in comparison to peptides including the native sequence. Likewise, the replacement of the glycine at position 9 with lysine, or the lysine at position 11 with histidine or phenylalanine, either singly or in combination, results in peptides with noticeably increased fungicidal activities in comparison to peptides having the native sequence. Acetylation or carbamylation of the N-terminus of the native sequence also yields peptides with significant antifungal activity.
An additional feature of the directed amino acid substitutions of the native sequence is that particular types of amino acid substitutions result in peptides with enhanced activities, e.g. antifungal, at non-neutral pH's. For example, the substitution of histidine at positions 7, 8, and 15 with phenylalanine results in peptides having significant antifungal activity at pH 4.0. Peptides with the native sequence are essentially devoid of antifungal activity at this lower pH.
At least some of the antifungal and antibacterial properties of the histatin-based peptides of the invention appear to reside in the amino acid sequence Ala-Lys-Arg-His-His-Gly-Tyr-Lys-Arg (SEQ ID NO:3). Peptide's containing this sequence, as well as peptides having one or more amino acids substituted at various positions of this sequence, are potent antifungal and antibacterial agents. Preferred peptides include those containing the amino acid sequences:
Ala-Lys-Arg-Phe-His-Gly-Tyr-Lys-Arg-Lys-Phe-His (SEQ ID NO:4);
Ala-Lys-Arg-His-Phe-Gly-Tyr-Lys-Arg-Lys-Phe-His (SEQ ID NO:5);
Ala-Lys-Arg-His-His-Gly-Tyr-Lys-Arg-Lys-Phe-Phe (SEQ ID NO:6);
Ala-Lys-Arg-Phe-Phe-Gly-Tyr-Lys-Arg-Lys-Phe-His (SEQ ID NO:7);
Ala-Lys-Arg-Phe-Phe-Gly-Tyr-Lys-Arg-Lys-Phe-Phe (SEQ ID NO:8);
Ala-Lys-Arg-His-His-Lys-Tyr-Lys-Arg-Lys-Phe-His (SEQ ID NO:9);
Ala-Lys-Arg-His-His-Gly-Tyr-His-Arg-Lys-Phe-His (SEQ ID NO:10);
Ala-Lys-Arg-His-His-Lys-Tyr-His-Arg-Lys-Phe-His (SEQ ID NO:11);
Ala-Lys-Arg-His-His-Gly-Tyr-Phe-Arg-Lys-Phe-His (SEQ ID NO:12); and
Ala-Lys-Arg-Tyr-Tyr-Gly-Tyr-Lys-Arg-Lys-Phe-Tyr (SEQ ID NO:13).
Combinations of two or more of these peptides are also effective as antifungal or antibacterial agents.
Therapeutic Applications
The peptides of the present invention can be used in pharmaceutical compositions to treat fungal infections, in particular candidal infection, as well as bacterial infections (e.g., S. mutans, P aeruginosa or P. gingivalis infections) and viral infections (e.g., the herpes simplex virus or human immunodeficiency virus type 1 infections). Vaginal, urethral, mucosal, respiratory, skin, ear, oral, or ophthalmic fungal or bacterial infections are particularly susceptible to histatin-based peptide therapy. Microbes which are specifically amenable to histatin-based peptide therapy include:
a) Candida albicans;
b) Actinomyces actinomycetemcomitans;
c) Actinomyces viscosus;
d) Bacteriodesforsythus;
e) Bacteriodesfragilis;
f) Bacteriodes gracilis;
g) Bacteriodes ureolyticus;
h) Campylobacter concisus;
i) Campylobacter rectus;
j) Campylobacter showae;
k) Campylobacter sputorum;
l) Capnocytophaga gingivalis;
m) Capnocytophaga ochracea;
n) Capnocytophaga sputigena;
o) Clostridium histolyticum;
p) Eikenella corrodens;
q) Eubacterium nodatum;
r) Fusobacterium nucleatum;
s) Fusobacterium periodonticum;
t) Peptostreptococcus micros;
u) Porphyromonas endodontalis;
v) Porphyromonas gingivalis;
w) Prevotella intermedia;
x) Prevotella nigrescens;
y) Propionibacterium acnes;
z) Pseudomonas aeruginosa;
aa) Selenomonas noxia;
bb) Staphylococcus aureus;
cc) Streptococcus constellatus;
dd) Streptococcus gordonii;
ee) Streptococcus intermedius;
ff) Streptococcus mutans;
gg) Streptococcus oralis;
hh) Streptococcus pneumonia;
ii) Streptococcus sanguis;
kk) Treponema denticola;
ll) Treponema pectinovorum;
mm) Treponema socranskii;
nn) Veillonellaparvula; and
oo) Wolinella succinogenes.
Carriers appropriate for administration of pharmaceutical agents to the vagina, the urethra, the ear, the oral cavity, the respiratory system, the ophthalmic region, various mucosal regions, and the skin are known and described, for instance, in Pollock et al., U.S. Pat. No. 4,725,576. Compositions for treatment of systemic infection can be administered by various routes, such as intravenously or subdermally.
Compositions containing the peptides of the present invention can be used in preventive treatment as well. The compositions may contain combinations of histatin-based peptides, in order to obtain maximum activity against all developmental forms of a fungus or bacterium. The ionic strength, presence of various mono- and divalent ions, and pH of the compositions may be adjusted to obtain maximum antifungal or antibacterial activity of the histatin-based peptides, as described in T. Xu et al., Infect. Immun. 59(8): 2549-54 (1991).
In addition, expression vectors encoding the above-mentioned peptides can be used in antifungal or antibacterial treatments. Expression vectors may be administered in compositions which introduce genetic material encoding histatin-based peptides into cells of the patients. For example, recombinant expression vectors based on retroviruses or adenovirus vaccines may be used to infect patients.
The above-described expression vectors can also be used in bacterial substitution therapy. Bacterial substitution therapy can be used to treat fungal or bacterial infection of areas in the urinary/reproductive, respiratory and/or gastrointestinal tracts of a patient. The therapy includes: (1) transforming a particular bacterium with DNA including an expression vector which encodes a histatin-based peptide described above, thereby producing transformed cells; (2) selecting transformed cells which express the peptide encoded by the expression vector, thereby obtaining transformed cells which express a histatin-based peptide; and (3) administering transformed cells which express a histatin-based peptide in an appropriate carrier to the infected area.
Another application of bacterial substitution therapy is treatment of fungal or bacterial infections of the oral cavity. A number of species of the oral bacteria Streptococcus can be used as vehicles for the expression vectors. For example, recombinant S. lactis has been used in oral immunization of mice against a heterologous antigen. Other oral bacteria which can be used as vehicles for expression vectors, plasmids for constructing expression vectors capable of amplification in oral bacterial host cells, transformation methods, and administration of compositions containing oral bacteria to humans have been described.
The pharmaceutical compositions used in the treatment of fungal, bacterial, or viral infections discussed above are not limited to use in humans, but can have veterinary applications as well.
Hemagglutination Activity of Bacteria and Histatin Inhibition of this Activity
Even though the association between hemagglutination activity and adherence on host cells in the oral environment is not clear, it is generally accepted that hemagglutination activity is an indicator for the colonizing ability of bacteria. Periodontal pathogens must adhere to other bacteria and host cells in order to express their noxious destructive potential upon periodontal tissues. Hemagglutination is thought to be involved in bacterial colonization.
Ability for adherence on erythrocytes is of great importance in the interactions of periodontal pathogens with the host. The close proximity of these bacteria with the host tissues as well as with erythrocytes that bathe the periodontal pocket during progression of the disease, indicates multiple interrelations between these elements. Additionally, periodontal microbes require heme-containing products for their survival and multiplication; this need dictates interactions with cells such as erythrocytes that are rich in these compounds. P. gingivalis has been shown to possess both hemagglutinins and hemolysin that provide attachment on erythrocytes and utilization of heme-compounds.
It has been shown that histatin 5 and histatin 8 inhibit hemagglutination of P. gingivalis 381. Complete hemagglutination inhibition was reported for histatin 5 at a concentration of 5 nmol/ml. Thus it appears that histatins and histatin-based peptides can play a role in inhibiting bacterial growth and deleterious activity in the periodontal region.
Clostripain Inhibition by Histatin-Based Peptides
Clostripain is an endopeptidase enzyme synthesized by Clostridium histolyticum . This enzyme, with its protein degradative activity, can be inhibited by histatin 5 and by histatin-based peptides. Thus, histatin-based peptides can inhibit bacterial function by inhibiting bacterial enzymes which are essential for bacterial viability.
OTHER EMBODIMENTS
From the above description, one skilled in the art can easily ascertain the essential characteristics of the present invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions. Thus, other embodiments are also within the claims.
Without further elaboration, it is believed that one skilled in the art can, based on the description herein, utilize the present invention to its fullest extent.
The following specific examples are, therefore, to be construed merely as illustrative, and do not limit the remainder of the disclosure in any way hatsoever. Publications mentioned herein are hereby incorporated by reference.
EXAMPLE 1
MATERIALS AND METHODS
A. Isolation and Chemical Synthesis of Histatin-Based Peptides
The isolation and amino acid sequence determination of human histatins are performed as described in F. G. Oppenheim et al., J. Biol. Chem. 263(16): 7472-7477 (1988). Human parotid secretion from healthy adults is stimulated using sour lemon candies, collected with Curby cups in ice-chilled graduated cylinders, pooled, dialyzed and lyophilized. The total protein in the human parotid secretion is subjected to fractionation on Bio-Gel P-2 (Bio-Rad Laboratories, Richmond, Calif.) developed in 0.05 M ammonium formate buffer, pH 4.0. The protein fractionation enriched with histatins is further purified using reverse-phase high-performance liquid chromatography on a C 18 column. Purified histatins are evaporated to dryness, dissolved in deionized water, quantified by amino acid analysis, lyophilized, and stored at −20° C. until use.
Histatin-based peptides are synthesized by the solid phase method of B. Merrifield, Science 232:341-47 (1986). Peptides are synthesized by a MilliGen/Bioresearch Sam-Two Peptide Synthesizer using Fmoc L-amino acid kits (Millipore, Bedford, MA) and purified on a TSK ODS-i2OT C 18 column (5 μm, 4.6×250 nm) using RP-HPLC (Pharmacia-LKB). The purified peptides are quantified by amino acid analysis on a Beckman System 6300 amino acid analyzer.
B. C. albincans Killing
1) C. albincans Stock
A well-described strain of C. albicans (strain ATCC 44505, which was originally isolated from the human oral cavity) is used in the bioassay. Cultures are stored at 4° C. on Sabourand dextrose agar plates (Difco Laboratories, Detroit, Mich.) until use. Stationary phase growth cells are obtained following growth at 30° C. for 18 hours on Sabourand dextrose agar plates. Colonies are harvested and suspended in 10 mM potassium phosphate buffer (PPB), pH 7.4.
To initiate log phase growth, an aliquot of stock C. albicans is suspended in Sabourand dextrose broth (Difco) and incubated at 30° C. in a shaking water bath. The growth phase is determined by taking aliquots of the culture at one hour intervals to monitor the optical density (O.D.) at 560 nm. Early log phase is obtained at 4 to 6 hours, indicated by an O.D. of about 0.6. Log phase cells are harvested and utilized in the blastoconidia killing assay in a manner identical to that described for stationary phase cells. A final concentration of 10 5 cells/ml (either stationary or log phase fungus) is used in all assays.
(2) Suspension Buffers
The standard suspension buffer utilized in the blastopore killing assay is 0.01 M PPB, pH 7.4. An alternate suspension buffer, N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid (HEPES; Sigma Chemical Co., St. Louis, Mo.), pH 7.4, can also be utilized.
(3) Bioassays
The following assay is used to evaluate the effects of histatins on the killing of blastoconidia of C. albicans.
a. For the killing of blastoconidia assay, 50 μl aliquots of cells (2×10 5 cells/ml) diluted in suspension buffer are allowed to attach to a polystyrene 96-well micro-titer plate (COSTAR, Cambridge, Mass.) for 15 minutes at room temperature, and then incubated with an equal volume of a histatin peptide in suspension buffer for 1 hour at 37° C. Controls are carried out in the absence of histatin peptide. After incubation, wells are washed three times by centrifugation at 1,000×g for 5 minutes and covered with aliquots of molten Sabourand dextrose broth (Difco) containing 2% agarose (Sigma) at 45° C. The plate is then incubated at 30° C. for 8 hours. Under such conditions, live cells will divide and begin to form colonies, while dead cells will remain as single cells. To determine the percentage of blastoconidia killed, a total of 100 single cells and/or colonies are counted under a Nikon inverted microscope at 400× magnification. The extent of killing is calculated using the formula: [1−(number of colonies in treated sample)/(number of colonies in control)]×100%.
(4) Statistical Analysis
Data are obtained by calculating the mean and standard deviation from triplicate assays. From the dose response relationship, doses effecting a 50% killing (LD 50 ) are determined.
C. Bacterial Growth Inhibition and Cell Killing Assays
(1) Bacterial Strains and Culture Conditions
a. The bacteria that is used in one investigation, Porphyromonas gingivalis strain A7A1-28, is a typical key pathogenic organism associated with destructive periodontal diseases. The bacteria are multiply subcultured in Enriched Todd Hewitt broth (ETHB, Difco Lab., Detroit, Mich.). Microorganisms are stored in the same broths containing 20% and 50% glycerol, at −20° C. and −70° C., respectively. These serve as stock cultures from which all preparations originate.
Working stock cultures are maintained by weekly transfer to Brain Heart Infusion Anaerobic Sheep Blood Agar plates (BHIA, Becton Dickinson and Co., Cockeysville, Md.), and Trypticase Soy Anaerobic Sheep Blood Agar plates (TSA, Becton Dickinson and Co., Cockeysville, Md.). Plates are incubated for 3 to 4 days under strictly anaerobic conditions. For the bacteriostatic assay, bacteria are collected from plates, inoculated into the aforementioned broth and grown at 37° C. under strictly anaerobic conditions for 24 to 48 hours.
b. Two other bacterial species are used in a bacterial cell killing assay system. These bacterial species are Streptococcus mutans strain SJ32 and Pseudomonas aeruginosa ATCC Accession No. 27853. The assays are performed using liquid overnight cultures (nutrient broth for P. aeruginosa ; Todd Hewitt broth for S. mutans ) of growth media from frozen stocks of these bacterial species. In the assay, the bacteria are diluted into assay buffer (10 mM Potassium Phosphate, pH 6.0 with 20 mM NaCl for P. aeruginosa ; and 10 mM Potassium Phosphate, pH 5.2 with 20 mM NaCl for S. mutans ) to a concentration of 2×10 5 cful/ml (1×10 9 cfu/OD/ml) and combined with an equal volume (250 μl) of peptide to produce 500 μl of incubation mixture with a final concentration of 10 5 cfu/ml. Controls constitute buffer and bacteria but no peptide. After incubation at 37° C. (30 minutes incubation for P. aeruginosa ; and 60 minutes incubation for S. mutans ), the mixtures are plated onto agar media (nutrient agar for P. aeruginosa ; and Todd Hewitt media with 0.5% glucose for S. mutans ) and incubated at 37° C. until colonies develop. The mean number of colonies is determined from a minimum of 4 plates, and percent killing is determined by comparing the colony number arising from control cultures versus the colony number arising from peptide-containing assay mixtures.
(2) Microdilution Bacteriostatic Assay
A modification of the typical microdilution assay for the determination of minimal inhibitory concentration (MIC) of antimicrobial agents is utilized to investigate the bacteriostatic activity of the peptides. A standardized bacterial inoculum ( P. gingivalis ) is exposed to serially diluted antimicrobial peptides in an enriched broth medium that is suitable for the growth of anaerobic bacteria. The test is adapted for use in the 96-well microtiter plates. Results with the microdilution method have been shown to be comparable to other known techniques for antimicrobial susceptibility such as the dilution method, the agar dilution method, and the broth-disk elution method. In the typical assay, the microtiter plate is observed at multiple time points after inoculation for visible growth. The modification introduced here is based on the spectrophotometric reading of the microtiter plate after incubation.
Microorganisms from cultures maintained in the aforementioned plates are inoculated into 5 ml of the above-mentioned broths and cultured overnight at 37° C. under strictly anaerobic conditions with continuous agitation on a minishaker (IKA-Labortechnik, Staufen i. Br., Germany). The bacteria are grown until reaching the late log phase and are then suspended in the same broths to an optical density (O.D.) of 0.1 at 560 μm. The peptides are diluted in 0.01 M phosphate buffered saline (PBS), pH 7. Forty-μl aliquots of peptide dilutions are added to each well of a U-bottom microtiter plate (Costar, Cambridge, Mass.) to give final concentrations of 2000, 1000, 500, and 250 μM. Twenty μl of bacterial inoculum are added to all the wells. Finally, 100 μl of the suitable broth are added to each well. The optical density of the wells of the microtiter plate is determined using a microplate reader set at 550 nm, and the plate is then incubated under strictly anaerobic conditions for 24 hours. Controls are made by replacing the peptide dilutions with PBS alone. After the incubation, the mixtures in each well are mixed manually to resuspend sedimented bacteria, and the plate is then read again. The experiments are conducted twice every time. The biologic activity is calculated according to the formula:
100−[[(Fin ODexp-In ODexp)/(Fin ODctr-In ODctr)]×100]
where:
Fin ODexp is the OD of the final experimental group;
In ODexp is the OD of the initial experimental group;
Fin ODctr is the OD of the final control group; and
In ODctr is the OD of the initial control group.
In addition, the % increase in time to reach mid-log phase growth is calculated.
D. Inhibition of Hemagglutination Assays
(1) Strains and Growth Conditions for Hemagglutination Assays
The P. gingivalis strain of Section C. (1) is also used for the hemagglutination assays. The bacterial growth and culture conditions are also the same as those described in Section C. (1).
(2) Hemagglutination Assay
A classic assay is utilized to determine the hemagglufination potential of the P. gingivalis strain. Microorganisms are inoculated into BFB broth and cultured overnight, for approximately 24 hours at 37° C. under strictly anaerobic conditions with continuous agitation on a minishaker (IKA-Labortechnik, Staufen i. Br., Germany). The bacteria are harvested by centrifugation at 3,000 r.p.m. for 20 minutes, at 4° C., washed twice in 0.01 M phosphate buffered saline (PBS), pH 7.4, and suspended in the same buffer to an optical density of 1.0 at 550 nm. Erythrocytes are obtained from a young male with O-type blood. (No difference in hemagglutination is observed in experiments with different ABO blood groups.) One ml of blood is drawn each time, washed twice in PBS at 1,000 r.p.m. for 10 minutes at 4° C. and suspended in the same buffer at a 2% (v/v) final concentration. Fifty μl of the bacterial suspension are serially diluted in PBS (two-fold steps) in a 96-well U-bottom microplate (Costar, Cambridge, Mass.). Fifty μl of the erythrocyte suspension are added to each well. Controls without bacteria or erythrocytes are included. The microplate is slightly shaken and incubated at room temperature for 2 hours. Visible examination on a white background is used to determine hemagglutination. The amount of hemagglutination is rated as none moderate (+/−), or strong (+). Erythrocytes in control wells with PBS precipitate to the center of the well, whereas erythrocyte-bacteria aggregates precipitate at the periphery of the bottom. The hemagglutination titer is expressed as the reciprocal of the highest dilution of the bacterial suspension providing visible hemagglutination.
(3) Histatin Peptide Inhibition of Hemagglutination Assay Preparation of erythrocyte and bacterial suspensions are the same as for the hemagglutination assay. Fifty μl of histatin peptide solutions are diluted in PBS in a U-bottom microplate, at various two-fold concentrations with 600 nmol/ml being the highest. The bacterial concentration utilized is normally twice the minimal concentration which gives strong hemagglutination. Equal volumes of the bacterial suspension are poured into the wells containing the histatin peptides. Finally, 50 μl of erythrocyte suspension are added in each well. The microplate is slightly shaken and incubated at room temperature for 2 hours. Controls are made by replacement of the peptide dilutions with PBS only. The experiments are conducted at least twice. The lowest histatin peptide concentration without hemagglutination is determined upon visual examination. The highest final histatin peptide concentration utilized is 100 nmol/ml.
E. Clostripain Assays
Clostripain from Clostridium histolyticum (Sigma Chemical Corp., St. Louis, Mo.) is dissolved in deionized water to a concentration of 1 mg/ml (300 units/mg) and activated with the addition of 10 mmol/L DTT. To measure its hydrolytic activity, clostripain ( 6 units) is added to 50 nmol/L Hepes buffer, pH 7.5, containing 80 μmol/L BAPNA (benzoyl-arginine-p-nitroanilide), together with 5.6 μmol/L of histatin peptide inhibitor. As controls, assays are performed in the absence of any histatin peptide inhibitor. The activity is monitored continuously at 405 nm using a Molecular Devices V max microtitre plate reader. The activities are determined from the maximum rates of substrate hydrolysis. Assays are done in duplicate, and the means normalized to the controls.
13
1
32
PRT
Homo sapiens
1
Asp Ser His Ala Lys Arg His His Gly Tyr Lys Arg Lys Phe His Glu
1 5 10 15
Lys His His Ser His Arg Gly Tyr Arg Ser Asn Tyr Leu Tyr Asp Asn
20 25 30
2
23
PRT
Homo sapiens
2
Asp Ser His Ala Lys Arg His His Gly Tyr Lys Arg Lys Phe His Glu
1 5 10 15
Lys His His Ser His Arg Gly
20
3
9
PRT
Homo sapiens
3
Ala Lys Arg His His Gly Tyr Lys Arg
1 5
4
12
PRT
Homo sapiens
4
Ala Lys Arg Phe His Gly Tyr Lys Arg Lys Phe His
1 5 10
5
12
PRT
Homo sapiens
5
Ala Lys Arg His Phe Gly Tyr Lys Arg Lys Phe His
1 5 10
6
12
PRT
Homo sapiens
6
Ala Lys Arg His His Gly Tyr Lys Arg Lys Phe Phe
1 5 10
7
12
PRT
Homo sapiens
7
Ala Lys Arg Phe Phe Gly Tyr Lys Arg Lys Phe His
1 5 10
8
12
PRT
Homo sapiens
8
Ala Lys Arg Phe Phe Gly Tyr Lys Arg Lys Phe Phe
1 5 10
9
12
PRT
Homo sapiens
9
Ala Lys Arg His His Lys Tyr Lys Arg Lys Phe His
1 5 10
10
12
PRT
Homo sapiens
10
Ala Lys Arg His His Gly Tyr His Arg Lys Phe His
1 5 10
11
12
PRT
Homo sapiens
11
Ala Lys Arg His His Lys Tyr His Arg Lys Phe His
1 5 10
12
12
PRT
Homo sapiens
12
Ala Lys Arg His His Gly Tyr Phe Arg Lys Phe His
1 5 10
13
12
PRT
Homo sapiens
13
Ala Lys Arg Tyr Tyr Gly Tyr Lys Arg Lys Phe Tyr
1 5 10 | Substantially pure peptides containing between 13 and 20 amino acids, inclusive, having the amino acid sequence: R1-R2-R3-R4-R5-R6-R7-R8-R9-R10-R11-R12-R13-R14-R15-R16-R17-R18-R19-R20-R21-R22-R23, where R1 is Asp or is absent; R2 is Ser or is absent; R3 is His or is absent; R4 is Ala; R5 is Lys, Gln, Arg, or another basic amino acid; R6 is Arg, Gln, Lys, or another basic amino acid; R7 is His, Phe, Tyr, Leu, or another hydrophobic amino acid; R8 is His, Phe, Tyr, Leu, or another hydrophobic amino acid; R9 is Gly, Lys, Arg, or another basic amino acid; R10 is Tyr; R11 is Lys, His, Phe, or another hydrophobic amino acid; R12 is Arg, Gln, Lys, or another basic amino acid; R13 is Lys, Gln, Arg, another basic amino acid, or is absent; R14 is Phe or is absent; R15 is His, Phe, Tyr, Leu, another hydrophobic amino acid, or is absent; R16 is Glu or is absent; R17 is Lys or is absent; R18 is His or is absent; R19 is His or is absent; R20 is Ser or is absent; R21 is His or is absent; R22 is Arg or is absent; and R23 is Gly or is absent; and where Gln cannot simultaneously occupy positions R5, R6, R12, and R13 of the amino acid sequence, as well as pharmaceutical compositions containing these peptides and methods for treating fuingal and bacterial infections using these peptides, are disclosed. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to a switching device for actuating an electrical drive motor of a working tool, for example, a vacuum cleaner. The switching device includes a microswitch with a switching pin for switching the microswitch on and off and an actuating element for actuating the switching pin.
Microswitches provided with a switching pin for operating an electrical drive motor of a working tool, for example, a household appliance like a vacuum cleaner, are known. With their help power to the drive motor can be supplied, respectively, interrupted. The switching pin can be switched on and off by an actuating element which protrudes through the casing of the appliance toward the exterior and can be actuated by the operator. Such microswitches are robust and can be manufactured easily; however, they are not able to carry out other operations than the switching on and off function. In particular, it is not possible with these microswitches to prevent, while the motor is running, the operator from reaching into the working tool into rotating members which is dangerous to the operating person, without providing additional safety measures.
It is, therefore, an object of the invention to suggest a microswitch with which an actuating of the drive motor in a dangerous situation can be securely prevented.
SUMMARY OF THE INVENTION
The switching device for actuating an electrical drive motor of a working tool according to the present invention is primarily characterized by:
a housing;
a microswitch, comprising a switching pin for switching on and off the microswitch, positioned in the housing;
an actuating element for actuating the switching pin positioned in the housing so as to be accessible from the exterior of the housing;
a switching mechanism comprising a plurality of members including the switching pin and the actuating element, wherein one of the members of the switching mechanism is moveable into an operating position in which the microswitch is operative and into a switched-off position in which the microswitch is switched off;
a locking element for arresting the moveable member in the operating position;
a releasable safety stop releasably connected to the housing;
the locking element resting on the releasable safety stop; and
wherein, when the releasable safety stop is released, the moveable member is switched into the switched-off position.
Preferably, the moveable member is the switching pin.
In another embodiment of the invention, the moveable member is a transfer lever positioned between the switching pin and the actuating element.
The transfer lever is connected to the locking element and is preferably supported at the locking element so as to be pivotable about a pivot axis. Advantageously, the transfer lever has an end face and is pivotably connected with the end face to the locking element.
The switching pin is preferably positioned at a greater distance to the pivot axis than a point of contact between the actuating element and the transfer lever.
In another embodiment, the switching pin and a point of contact between the actuating element and the transfer lever are positioned at opposite ends of the transfer lever.
The microswitch is expediently pivotable about a pivot axle fixedly connected to the housing.
The switching device preferably further comprises a stop fixedly connected to the housing, wherein in the switched-off position the switching pin rests at the stop.
The microswitch advantageously comprises a projection which is unitary with the microswitch and wherein the projection forms the locking element.
The locking element is a stop pin that is movably connected to the microswitch.
Preferably, a guide connected to the housing is provided in which guide the stop pin is guided translatorily.
The switching device amy further comprise a spring connected to the stop pin for biasing the stop pin such that the moveable member is biased into the operating position, wherein the force of the spring is smaller than an actuating force acting on the moveable member for switching on the microswitch. Preferably, the safety stop is a pivotable member of the working tool. The pivotable member is expediently a cover. When the cover is in an open position, the moveable member is in the switched-off position.
The actuating element is a pivot lever having a contour with projections and recesses defining the operating position and the switched-off position.
The pivot lever is pivotable about an angular range of substantially 90°, wherein each one of the end positions of the pivot lever within the angular range defines the switched-off position.
Preferably, a stop lever is provided, wherein the pivot lever has a contour with depressions and wherein the stop lever engages lockingly in the end positions and in an intermediate position of substantially 45° one of the depressions of the contour of the pivot lever.
The stop lever expediently comprises a locking portion biased in the direction of engaging the depressions.
A release lever for releasing the stop lever from the depressions is advantageously provided.
According to the invention, a switching mechanism for switching the microswitch is provided. This mechanism comprises at least the actuating element and the switching pin and a member of this switching mechanism is designed to be moveable from an operating position to a switched-off position. This member of the switching mechanism is the switching pin in a preferred embodiment and can be locked in its operating position by a locking element which is supported on a releasable safety stop and can be moved into the switched-off position when the safety stop is released. During operation the safety stop prevents that the locking element, due to an actuating force acting on the switching pin of the microswitch, is moved into a position disabling the switching mechanism such that the drive motor is inadvertently turned off. On the other hand, as a safety measure, the microswitch cannot be switched on if the locking element is not supported on the safety stop which, for example, can be formed as a casing portion covering the drive motor as well as further rotating members of the working tool.
In a preferred embodiment, the microswitch is designed to be pivotable about a fixedly mounted pivot axle whereby the switching pin is moved from its operating position into its non-operating position. The locking element can be designed as a stop pin that is pivotably (movably) connected with the microswitch. A free end thereof is supported on the releasable safety stop in the operating position. Preferably, the stop pin is spring-loaded in the direction of the operating position, with the force of the spring being lower than the actuating force acting on the switching pin. Thus, it is ensured that the switching pin is transferred into its switched-off position when the safety stop is released; on the other hand, the switching pin can be easily moved back into its operating position in any position of the appliance whereby the switching mechanism is enabled again.
According to a further embodiment it is suggested to provide a transfer lever between the actuating element and the switching pin; advantageously this transfer lever is pivotably supported on the locking element and, in the operating position, transfers the actuation of the actuating element onto the switching pin. When the safety stop is released, the locking element travels into a recess and moves the transfer lever into the switched-off position in which the drive motor cannot be turned on.
Advantageously, the safety stop is a member of the working tool and can be swivelled, like, for example, a cover. Therefore, additional safety measures which are to prevent a reaching in from the exterior can be left out.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects and advantages of the present invention will appear more clearly from the following specification in conjunction with the accompanying schematic drawings, in which:
FIG. 1 shows a side view of the inventive microswitch with a switching mechanism comprising an actuating element and a switching pin, illustrated in switched-off position of the microswitch;
FIG. 2 shows a microswitch in a switched-on position (solid lines);
FIG. 3 illustrates the microswitch in a switched-off position (solid lines) with the safety stop being released;
FIG. 4 illustrates the microswitch according to FIG. 3 with a locking element of a different design;
FIG. 5 shows a cross-section according to FIG. 1 with a microswitch and a switching mechanism comprising actuating element, transfer lever, and switching pin;
FIG. 6 shows a plan view of the embodiment according to FIG. 5;
FIG. 7 illustrates the embodiment according to FIG. 5, in operating position;
FIG. 8 shows a plan view of the embodiment according to FIG. 7;
FIG. 9 illustrates the embodiment according to FIG. 5, in a switched-off position with the safety stop being released;
FIG. 10 shows a plan view of the embodiment according to FIG. 9; and
FIG. 11 shows a cross-section according to FIG. 9 with the safety stop being blocked.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a cross-sectional side view of a working tool 1, for example, a household appliance like a vacuum cleaner, with a microswitch 2 for actuating a not illustrated electrical drive motor. The microswitch is mounted in a housing 26 and can be actuated from the exterior via an actuating element 27 which is designed in the illustrated embodiment as a rotatable pivot lever 16 penetrating the housing wall. In FIG. 1 the microswitch 2 is illustrated in a switched-off position; a switching pin 14 of the microswitch 2 that can be pushed into the micro-switch 2 for activating it (activation position), abuts the pivot lever 16 and, in conjunction with it, forms a switching mechanism 3 for transferring the switching travel onto the switching pin 14.
The microswitch 2 is pivotably supported on a fixedly mounted pivot axle 10 and can, as is illustrated in FIG. 2, be pivoted into two positions by rotation about the pivot axle 10. In order to prevent an inadvertent rotation of the microswitch 2 from the operating position 4 (FIGS. 1 and 2) into the switched-off position 5 (FIG. 3) in which the switching pin 14 is in the extended deactivation position, a locking element 6 is arranged at the microswitch 2; in FIGS. 1, 2, and 3, the locking element 6 is embodied as a stop pin 8 that is pivotably connected to the microswitch. In the operating position 4, its free end, positioned opposite the microswitch 2, abuts a safety stop 9. When the stop pin 8 abuts the safety stop 9, the operating position of the switching pin 14 is fixedly defined; a slipping of the stop pin 8 and the microswitch 2, due to switching forces acting on the switching pin 14, are precluded so that the switching mechanism 3 is enabled.
According to a not illustrated embodiment, the microswitch can also be displaced translatorily.
The stop pin 8 is essentially translatorily movable in a guide 13 that can, for example, be formed by a recess or a bore 31 within the housing wall (FIG. 3). Expediently, the stop pin 8 is spring-loaded in the direction of the operating position 4 for which purpose a spring 28 is provided that encloses the stop pin 8 and is arranged on a part 29 that is designed as a sleeve which is slipped onto the stop pin 8 to be axially freely movable. The part 29 has a closed end face opposite the microswitch. The spring 28 is a compression spring; however, its compression force, at any position of the microswitch, is lower than the switching force that acts on the switching pin 14 and that is required for switching on the drive motor. Releasing the safety stop 9 from its blocking position results in the stop pin 8 traveling into the recess 31, due to the pressure of the switching force acting on the switching pin 14, and in the switching pin 14 arriving at its switched-off position by rotation of the microswitch 2. However, if the switching force acting on the switching pin 14 is reduced, the microswitch 2 can travel back into the operating position 4 by the force of the compression spring 28, independent of the position of the appliance (see FIGS. 2 and 3).
The spring 28 can also be formed as an tension spring, one end of which is attached to the means 29 designed as a ring flange being formed as a unitary part with the stop pin and the other end of which is supported on the interior wall 30 of the housing 26. The spring action of the spring 28 results in the stop pin 8 being pulled deeper into the recess 31 by the force of the spring when the safety stop 9 is swivelled off its blocking position; thereby, the switching pin 14 is displaced from its operating position into its switched-off position.
In a particularly simple embodiment the spring 28 can be omitted as long as it is ensured that a switching force acting on the switching pin 14 for displacing the locking element and the microswitch 2 from the operating position 4 into the switched-off position 5 is lower than the force required for starting the drive motor. Thereby it remains ensured that the microswitch 2 is pivoted under the action of the switching force when the safety stop 9 is opened, without the switching pin 14 being switched into its operating position; the part 29 may then be omitted. If the switching force for swivelling the microswitch is not acting, stop element and microswitch can, at least in the working position of the appliance, also return into the operating position 4 due to the own weight of the microswitch.
The safety stop 9 is expediently designed as a pivotable member 11 of the appliance 1, for example, a cover 12, which can be removed for cleaning and maintenance in the case of a vacuum cleaning appliance with a brushing roller. With this embodiment it is securely prevented that the drive motor can be activated in the lifted position of the cover 12' illustrated in FIGS. 2 and 3. In the lifted position, the front wall 32, forming the safety stop 9, of the cover, is lifted off the recess 31 such that the stop pin 8 can travel farther into the recess 31 and the switching pin 14 is moved from its operating position 4 into its switched-off position 5. Now, the microswitch 2 cannot be actuated any more so that maintenance and cleaning of those parts located under the cover 12, like the brushing roller or the like, are possible without any risk of injury.
The swivelling path of the microswitch 2 can be blocked by a further, fixedly mounted stop 15 at which the switching pin 14 of the microswitch 2 advantageously rests in the switched-off position 5 in order to limit a maximum rotation of the microswitch 2 and to facilitate the return into the operating position. The end position can also be determined by the free end of the stop pin 8 hitting a rear wall 33 of the casing 26 after releasing and lifting the cover 12, according to FIG. 3. In order to facilitate a return of the switching pin 14 from the switched-off position into the operating position, it may be advisable to provide the free end of the front wall 32 of the cover 12, according to a non-illustrated embodiment, with a tapered surface that facilitates a return of the stop pin 8 against the force of the spring 28 on closing the cover 12. Moreover, the stop 15 is helpful when the appliance is assembled since the mounting position of the microswitch 2 is clearly defined by it.
The switching pin 14 of the microswitch 2 can be actuated by rotating the pivot lever 16 that projects through the wall of the housing 26 to the exterior. The switching pin 14 abuts the contour 17 of the pivot lever 16 at an approximately concentric distance to the pivot axis 34 and engages projections 18 and recesses 19 of the contour 17. A switched-off position of the microswitch 2 (FIG. 1) is defined by the switching pin 14 engaging recesses 19, whereas a switched-on position is defined when the switching pin 14 abuts a projection 18 and is pushed into the microswitch 2, see FIG. 2. According to FIG. 1, the pivoted lever 16 can be advantageously swivelled at an angular range 20 of approximately 90° from a vertical end position 21 into a horizontal end position 22. The end positions 21 and 22 each define a switched-off position in which the switching pin 14 engages a recess 19 of the contour 17. However, in an intermediate position 23 of preferably approximately 45°, the switching pin 14 abuts a projection 18 by means of which the switching pin 14 is pushed into the microswitch 2 and the drive motor is started.
In a further embodiment according to FIG. 4, the locking element 6 of the microswitch 2 can also be designed as an projection 7 that forms a unitary member together with the microswitch 2 and is a portion of the enclosure of the microswitch. The free end 7' of the projection 7 protrudes through the recess 31 within the wall of the housing 26 at the switched-off position 5. In the operating position 4, the projection 7 is pushed downward by the bottom edge 38 of the front wall 32 of the cover 12 and is kept in this position. The transfer from the operating position 4 into the switched-off position 5 is carried out by the force of a spring, not illustrated, or by a transversely acting force at the resting point 39 located between the contour 17 of the pivoted lever 16 and the switching pin 14; the transversely acting force is located at a distance to the pivot axle 10 of the microswitch and a torque acting on the microswitch 2 is thus formed.
FIGS. 5 to 11 illustrate a further embodiment in which the switching mechanism 3 comprises the actuating element 27, an adjustable transfer lever 42 and the switching pin 14; the same reference numerals are used for the same members. In this embodiment, the microswitch 2 is fixedly connected to the casing 26 by screw connections 44. The operating position 4 (FIGS. 5 to 8) and the switched-off position 5 (FIGS. 9 to 11) are exclusively determined by the position of the transfer lever 42. As is illustrated in the plan views of FIGS. 6, 8, and 10, the locking element 6 which is formed by the stop pin 8 is designed to be off-set parallel to the microswitch 2. The stop pin 8 is translatorily displaceable in a guide 45 (not illustrated in detail) and can travel deeper into the recess 31 of the wall of the casing 26 when the safety stop 9 is released by lifting the cover 12' (FIGS. 9 and 11), whereby the transfer lever 42 is positioned in the switched-off position 5 and the switching mechanism 3 is disabled.
At one end face 46, the transfer lever 42 is mounted at the locking element 6 so as to be pivotable about a pivot axis 43. The free end of the transfer lever 42 projects past the switching pin 14 of the microswitch 2 such that the switching pin 14 can be switched on by a rotating movement of the transfer lever 42.
On the opposite side of the switching pin 14, an actuating means 48 is arranged as to be connected with the transfer lever as a single piece and it abuts the contour 17 of the pivoted lever 16. The actuating member 48 is arranged at a shorter distance to the pivot axis 43 than the switching pin 14.
An actuating movement carried out by the pivot lever 16 from the switched-off position according to FIGS. 5 and 6 to an operating position according to FIGS. 7 and 8 results in the actuating member 48 to be pushed down and thus a rotation of the transfer lever 42 which moves the switching pin 14 of the microswitch 2 into the operating position. Due to the greater distance of the switching pin 14 to the pivot axis 43 than to the actuating member 48, even a short actuating travel acting on the actuating member 48 is sufficient for carrying out the required lift for moving the switching pin 14 into the operating position.
During this process, the actuating travel carried out by the pivot lever 16 is transformed into a pure rotating movement of the transfer lever 42 since the stop pin 8 with its free end abuts the safety stop 9 and cannot withdraw translatorily.
FIGS. 9, 10, and 11 illustrate the transfer lever 42 in the switched-off position 5 in which the switching mechanism 3 is disabled and the microswitch 2 is not switched on. The cover 12, the front wall 32 of which forms the safety stop 9, is in a lifted position, removed from the recess 31, whereby the stop pin 8 is backwardly displaced into abutment at a rear wall 33 due to the force of the pivot lever acting on the actuating means 48.
At the surface of the transfer lever 42, opposite the actuating member 48, a spring 28, preferably a coil spring, is arranged. Its end positioned opposite the transfer lever 42 is supported at the screw connection 44 by which the microswitch 2 is mounted to the housing. Relative to the pivot axis 43, the spring 28 is designed to be located between the actuating means 48 and the switching pin 14. An actuating movement of the pivot lever 16 in the direction of the switched-off position 5 of the transfer lever 42 leads to a force acting onto the spring 28 which results in the transfer lever 42 to open due to the greater distance of the spring 28 relative to the pivot axis 43 than to the actuating member 48. This causes the stop pin 8 to be displaced into the recess 31 whereby the transfer lever is moved into the switched-off position 5. Through the opening of the transfer lever 42, the point of application of force between pivot lever 16 and actuating member 48 shifts from the tip to the lateral mantle surface of the actuating member 48 such that the transfer levers 42, when the stop pin 8 is displaced further into the recess 31, is opened further and further due to the pressure of the spring 28. Accordingly, the actuating movement of the pivot lever 16 is more and more oriented in the direction of the translatory movement of the stop pin 8. By the opening of the transfer lever 42, it is securely prevented that the free end of the transfer lever can act on the switching pin 14 and thus may lead to an inadvertent starting of the drive motor.
When the pivot lever 16 is returned into its starting position according to FIGS. 5 or 6, the actuating member 48 slips into the recess 19 of the contour 17 of the pivot lever 16 under the force of the spring 28. Simultaneously the stop pin 8 is pulled out of the recess 31 and returned from the switched-off position 5 into operating position 4.
According to a non-illustrated embodiment the spring 28 can also be omitted, as long as it is ensured that the force required for switching on the switching pin 14 is higher than frictional forces within the supporting location of the stop pin 8 and within the pivot axle, respectively the location of contact 47 between pivot lever 16 and actuating members 48. If the spring is omitted, an actuating movement of the pivoted lever 16 will press the transfer lever 42 onto the switching pin 14 even if the safety stop is released; however, with increasing actuating travel of the pivot lever 16, the switching-on force within the switching pin 14 will result in the stop pin 8 to be displaced into the recess 31 before the operating position of the switching pin 14 is reached. If the actuating movement of the pivot lever 16 is reversed, the transfer lever 42 can again be returned into the operating position 4 by the force within the switching pin 14. This procedure can be supported by bevelling the lower edge 38 of the safety stop 9 whereby the insertion of the cover 12 into its stop position is facilitated when the stop pin 8 is not or only partly retracted.
According to FIG. 1, moreover, a stop lever 24 expediently abuts the contour 17 of the pivot lever 16 and is offset downwardly by approximately 90 degrees relative to the microswitch 2. A locking portion 35 is formed at one free end of the stop lever 24 and engages further recesses 40 of the pivot lever 16 in a locking manner in the two end positions 21 and 22 as well as at the intermediate position 23 and thus prevents a rotation of the pivot lever 16. As a result, the end positions 21 and 22 in which the microswitch 2 is switched off, independent of the position of the cover 12, as well as the intermediate position 23 in which the microswitch is switched on, can be locked. The stop lever 24 is supported at the housing wall by a spring 36, and the locking portion 35 of the stop lever 24 is pressed against the contour 17 of the pivoted lever 16 by the force of the stopping spring 36. A release lever 25 is provided for releasing the locking portion 35 from engagement. It is pivoted about the same pivot axis 34 as the pivot lever 16 and protrudes through the opening within the wall of the housing 26 to allow actuation. The release lever 25 is provided with a tooth-shaped projection 37 which contacts the upper surface of the stop lever 24 when the operator pushes the release lever 25 down and thus releases the locking engagement by the locking portion 35 of the stop lever 24 by pushing it out of the recess 40. A swiveling of the pivot lever 16 is thus again possible until the locking portion 35 again engages a recess 40 in a locking manner. During the swivelling movement of the pivot lever 16, the tooth-shaped projection 37 always contacts the upper surface of the stop lever 24 due to a self-locking friction, for example, within the pivot joint of the release lever 25, and is being forced back into its upper starting position by the force of the spring 36 when the locking portion 35 again engages a recess 40. Advantageously, the friction is higher than the torque acting about the pivot axis 34 and caused by the weight of the release lever, such that the stop lever 24 is relieved from the weight of the release lever 25 after the swivelling process is terminated.
At its intermediate position 23, the pivot lever 16 is advantageously only locked in the direction of its horizontal end position 22 in order to prevent an unintentional downward swivelling due to the weight of the pivot lever 16. For this reason, the locking portion 35 abuts, according to FIG. 2, a projecting portion 41 of the recess 40, whereas the side of the contour opposite the projecting portion 41 is open so that the pivot lever 16 can be swivelled upwardly by the operator into its upper end position 21 (FIG. 1) without actuating the release lever 25.
In the case of a vacuum cleaner, the pivot lever 16 is expediently identical with the lower section of the grip bar of the vacuum cleaning appliance, respectively, it forms a projection, onto which the grip bar can be slipped. In this case, the intermediate position 23 defines the working position, whereas storing positions of the appliance are determined by the end positions 21 and 22.
The present invention is, of course, in no way restricted to the specific disclosure of the specification and drawings, but also encompasses any modifications within the scope of the appended claims. | The switching device for actuating an electrical drive motor of a working tool has a housing and a microswitch, including a switching pin for switching on and off the microswitch, positioned in the housing. An actuating element for actuating the switching pin is positioned in the housing so as to be accessible from the exterior of the housing. A switching mechanism with a plurality of members including the switching pin and the actuating element is provided. One of the members of the switching mechanism is moveable into an operating position in which the microswitch is operative and into a switched-off position in which the microswitch is switched off. A locking element for arresting the moveable member in the operating position is provided. A releasable safety stop is releasably connected to the housing. The locking element rests on the releasable safety stop. When the releasable safety stop is released, the moveable member is switched into the switched-off position. | 0 |
CROSS REFERENCES
[0001] This application claims the benefit of U.S. Provisional Application 60/340,419 filed Dec. 14, 2001 and U.S. patent application Ser. No. 10/057,759 filed Jan. 25, 2002.
TECHNICAL FIELD
[0002] A major objective of chronotherapy for indications such as asthma, gastric acid secretion and cardiovascular diseases is to deliver the drug in higher concentrations during the time of greatest need and in lesser concentrations when the need is less. Symptoms associated with “GERD” (Gastro Esophageal Reflux Disease) vary in severity throughout a 24-hour period. Accordingly, higher plasma concentrations of a histamine H 2 antagonist, such as nizatidine, are required to provide relief from acid secretion in response to fatty meals, as well as to attenuate the “midnight gerd” seen to occur in patients in response to the circadian rhythm to gastric acid secretion, while lower plasma concentrations are adequate in early morning hours and between meals. This is accomplished by administering a pulsatile release dosage form of the present invention, which provides a controlled release of an histamine H 2 antagonist from properly designed dosage forms. In particular, the present invention relates to a unit dosage form of an assembly of two or more bead populations, each of which is designed to release the therapeutic agent as a rapid or sustained release pulse after a predetermined delay with resulting plasma concentration varying in a circadian rhythm fashion, thereby enhancing patient compliance and therapeutic efficacy, reducing both cost of treatment and side effects.
BACKGROUND OF THE INVENTION
[0003] Many therapeutic agents are most effective when made available at a constant rate at or near the absorption site. The absorption of therapeutic agents thus made available generally result in desired plasma concentrations leading to maximum efficacy, minimum toxic side effects. Much effort has been devoted to developing sophisticated drug delivery systems, such as osmotic devices, for oral application. However, there are instances where maintaining a constant blood level of a drug is not desirable. For example, a “position-controlled” drug delivery system (e.g., treatment of colon disease or use of colon as an absorption site for peptide and protein based products) may prove to be more efficacious. A pulsatile delivery system is capable of providing one or more immediate release pulses at predetermined time points after a controlled lag time or at specific sites. However, there are only a few such orally applicable pulsatile release systems due to the potential limitation of the size or materials used for dosage forms. Ishino et al. disclose a dry-coated tablet form in Chemical Pharm. Bull. Vol. 40 (11), 3036-041 (1992). U.S. Pat. No. 4,851,229 to Magruder et al., U.S. Pat. No. 5,011,692 to Fujioka et al., U.S. Pat. No. 5,017,381 to Maruyama et al., U.S. Pat. No. 5,229,135 to Philippon et al., and U.S. Pat. No. 5,840,329 to Bai disclose preparation of pulsatile release systems. Some other devices are disclosed in U.S. Pat. No. 4,871,549 to Ueda et al. and U.S. Pat. Nos. 5,260,068; 5,260,069; and 5,508,040 to Chen. U.S. Pat. Nos. 5,229,135 and 5,567,441 both to Chen disclose a pulsatile release system consisting of pellets coated with delayed release or water insoluble polymeric membranes incorporating hydrophobic water insoluble agents or enteric polymers to alter membrane permeability. U.S. Pat. No. 5,837,284 to Mehta et al. discloses a dosage form which provides an immediate release dose of methylphenidate upon oral administration, followed by one or more additional doses spread over several hours.
[0004] Studies have shown that gastric acid secretion, especially the midnight gerd, follows a circadian rhythm. In such cases, administration of a different kind of unit dosage form which delivers the drug in higher concentrations during the time of greatest need, for example, around dinner and close to midnight, and in lesser concentrations at other times, is needed. Commonly assigned and co-pending U.S. application Ser. No. 09/778,645, which is incorporated in its entirety, discloses a pulsatile release system comprising a combination of two or three pellet populations, each with a well-defined release profile. In accordance with the present invention, a plasma profile is obtained which varies in a circadian rhythm fashion following administration of the novel dosage form.
SUMMARY OF THE INVENTION
[0005] The present invention provides a pulsatile release, multi-particulate dosage form comprising a mixture of two types of beads comprising a histamine H 2 receptor antagonist: IR (Immediate Release) Beads and TPR (Timed Pulsatile Release) Beads. Release profiles which approximate the daily fluctuations in gastric acid secretion are obtainable by blending IR Beads and TPR Beads at an appropriate ratio estimated from pharmaco-kinetic modeling. The IR Beads typically comprise two coatings applied to non-pareil seeds (# 25-30 mesh). The first coating contains a histamine H 2 antagonist and a binder, such as hydroxypropyl cellulose. The drug layered beads are coated with a seal coating of Opadry Clear to produce IR Beads. TPR Beads can be produced by applying a second functional membrane comprising a mixture of water insoluble polymer and an enteric polymer to IR Beads, both plasticized polymeric systems being applied from aqueous or solvent based systems.
[0006] The pulsatile release oral capsule formulation of the present invention comprises a combination of two types of spherical beads containing the active substance. IR (immediate release) Beads allow immediate release of the active while TPR Beads allow a delayed “burst” release (timed pulsatile release) of the active after a lag of 3-4 hours. When administered at bedtime (capsule containing IR Beads+TPR beads), the immediate release of the active is intended to provide relief from acid secretion in response to the meal, while the delayed “burst” is intended to attenuate the “midnight gerd” seen to occur in patients in response to the circadian rhythm to gastric acid secretion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The invention will be described in further detail with reference to the accompanying Figures wherein:
[0008] [0008]FIG. 1 shows Circadian Rhythm variations in gastric acid secretion (Reference: the presentation by Gordon L. Amidon at the Formulation Optimization and Clinical Pharmacology, a Capsugel Sponsored Conference at Tokyo, Apr. 23, 1999, p. 16).
[0009] [0009]FIG. 2 shows the drug release profiles from Nizatidine Pulsatile Capsules, 150 mg (75 mg IR Beads+75 mg TPR Beads) of Example 1, wherein the TPR Beads have different pulse coating levels.
[0010] [0010]FIG. 3 shows the drug release profile for Nizatidine Pulsatile Capsules, 150 mg (75 mg IR Beads+75 mg TPR Beads) of Example 2.
[0011] [0011]FIG. 4 shows the target or simulated in vitro drug release profile used in PK simulation.
[0012] [0012]FIG. 5 compares the simulated plasma levels of Nizatidine Pulsatile Capsule versus 300 mg IR Dose following oral administration at (a) night time and (b) day time.
[0013] [0013]FIG. 6 shows the plasma level of Nizatidine following oral administration in a healthy volunteer when dosed after dinner with Pulsatile Capsule, 150 mg (75 mg IR Beads+75 mg TPR Beads) (a bimodal display) versus 150 mg IR Dose.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The active core of the novel dosage form of the present invention may be comprised of an inert particle or an acidic or alkaline buffer crystal, which is coated with a drug-containing film-forming formulation and preferably a water-soluble film forming composition to form a water-soluble/dispersible particle. Alternatively, the active may be prepared by granulating and milling and/or by extrusion and spheronization of a polymer composition containing the drug substance. The amount of drug in the core will depend on the dose that is required, and typically varies from about 5 to 90 weight %. Generally, the polymeric coating on the active core will be from about 1 to 50% based on the weight of the coated particle, depending on the lag time and type of release profile required and/or the polymers and coating solvents chosen. Those skilled in the art will be able to select an appropriate amount of drug for coating onto or incorporating into the core to achieve the desired dosage. In one embodiment, the inactive core may be a sugar sphere or a buffer crystal or an encapsulated buffer crystal such as calcium carbonate, sodium bicarbonate, fumaric acid, tartaric acid, etc. which alters the microenvironment of the drug to facilitate its release.
[0015] To produce Timed Pulsatile Release (TPR) Beads, a water soluble/dispersible drug-containing particle is coated with a mixture of a water insoluble polymer and an enteric polymer, wherein the water insoluble polymer and the enteric polymer may be present at a weight ratio of from 4:1 to 1:1, and the total weight of the coatings is 10 to 60 weight % based on the total weight of the coated beads. The drug layered beads may optionally include an inner dissolution rate controlling membrane of ethylcellulose. The composition of the outer layer, as well as the individual weights of the inner and outer layers of the polymeric membrane are optimized for achieving desired circadian rhythm release profiles for a given active, which are predicted based on in vitro/in vivo correlations. In accordance with one embodiment of the present invention, a unit dosage form is provided wherein the unit dose comprises a mixture of immediate release beads (IR Beads, which are drug-containing particles without a dissolution rate controlling polymer membrane) and TPR Beads (drug containing particles with a coating of a blend of water insoluble polymer and enteric polymer exhibiting a lag time of 2-4 hours following oral administration), thus providing a two-pulse release profile. A unit dosage form, which does not comprise a rapid release bead population acting as a bolus dose, is also an embodiment of the present invention.
[0016] The present invention also provides a method of making a pulsatile release dosage form comprising a mixture of two bead populations comprising the steps of:
[0017] 1. preparing a drug-containing core by coating an inert particle such as a non-pareil seed, an acidic buffer crystal or an alkaline buffer crystal with a drug and a polymeric binder or by granulation and milling or by extrusion/spheronization to form an immediate release (IR) bead;
[0018] 2. coating the IR bead with a mixture of plasticized water-insoluble and enteric polymers to form a Timed Pulsatile Release (TPR) bead;
[0019] 3. filling into hard gelatin capsules IR beads and TPR beads at a proper ratio to produce pulsatile capsules providing the desired release profile.
[0020] The release profile for TPR beads can be determined according to the following procedure:
[0021] Dissolution Procedure:
[0022] Dissolution Apparatus: USP Apparatus 2 (Paddles at 50 rpm) using a two-stage dissolution medium (first 2 hrs in 700 mL 0.1 N HCl at 37° C. followed by dissolution at pH=6.8 obtained by the addition of 200 mL of pH modifier) and Drug Release determination by HPLC).
[0023] The TSR Beads prepared in accordance with present invention release, when tested by the above procedure, not more than 25%, more preferably not more than 15%, and most preferably not more than 5% in 2 hours, about 15-80%, more preferably about 20-65%, and most preferably about 30-50% in 3 hours, and not less than 60%, more preferably not less than 70%, and most preferably not less than 80% in 4 hrs.
[0024] Dosage forms in accordance with the present invention typically comprise a combination of IR Beads and TPR Beads at a ratio from 3:1 to 1:3, preferably a ratio from 2:1 to 1:2. In accordance with certain embodiments, the ratio of IR Beads to TPR Beads is approximately 1:1.
[0025] The histamine H 2 receptor antagonists suitable for incorporation into these circadian rhythm release (CRR) drug delivery systems include acidic, basic, zwitterion, or neutral bioactive molecules or their salts indicated for the treatment of active duodenal ulcer, such as nizatidine, cimetidine, ranitidine, and famotidine.
[0026] An aqueous or a pharmaceutically acceptable solvent medium may be used for preparing drug-containing core particles. The type of film forming binder that is used to bind the drug to the inert sugar sphere is not critical but usually water soluble, alcohol soluble or acetone/water soluble binders are used. Binders such as polyvinylpyrrolidone (PVP), polyethylene oxide, hydroxypropyl methylcellulose (HPMC), hydroxypropylcellulose (HPC), polysaccharides such as dextran, corn starch may be used at concentrations of 0.5 to 5 weight %. The drug substance may be present in this coating formulation in the solution form or may be dispersed at a solid content up to 35 weight % depending on the viscosity of the coating formulation.
[0027] The drug substance, a binder such as PVP, a dissolution rate controlling polymer (if used), and optionally other pharmaceutically acceptable excipients are blended together in a planetary mixer or a high shear granulator such as Fielder and granulated by adding/spraying a granulating fluid such as water or alcohol. The wet mass can be extruded and spheronized to produce spherical particles (beads) using an extruder/marumerizer. In these embodiments, the drug load could be as high as 90% by weight based on the total weight of the extruded/spheronized core.
[0028] The active containing cores (beads, pellets or granular particles) thus obtained may be coated with one or two layers of dissolution rate controlling polymers to obtain desired release profiles with or without a lag time. The inner layer membrane largely controls the rate of drug release following imbibition of water or body fluids into the core while the outer layer membrane provides for the desired lag time (the period of no or little drug release following imbibition of water or body fluids into the core). The inner layer membrane may comprise a water insoluble polymer, or a mixture of water insoluble and water soluble polymers. Representative examples of water insoluble polymers useful in the invention include ethylcellulose, polyvinyl acetate (Kollicoat SR#0D from BASF), neutral copolymers based on ethyl acrylate and methylmethacrylate, copolymers of acrylic and methacrylic acid esters with quaternary ammonium groups such as Eudragit NE, RS and RS30D, RL or RL30D and the like. Representative examples of water soluble polymers are low molecular weight HPMC, HPC, methylcellulose, polyethylene glycol (PEG of molecular weight>3000) at a thickness ranging from 1 weight % up to 10 weight % depending on the solubility of the active in water and the solvent or latex suspension based coating formulation used. The water insoluble polymer to water soluble polymer may typically vary from 95:5 to 60:40, preferably from 80:20 to 65:35.
[0029] The polymers suitable for the outer membrane, which largely controls the lag time of up to 6 hours may comprise an enteric polymer and a water insoluble polymer at a thickness of 10 to 50 weight %. The ratio of water insoluble polymer to enteric polymer may vary from 4:1 to 1:2, preferably the polymers are present at a ratio of about 1:1. The water insoluble polymer typically used is ethylcellulose.
[0030] Representative examples of enteric polymers useful in the invention include esters of cellulose and its derivatives (cellulose acetate phthalate, hydroxypropyl methylcellulose phthalate, hydroxypropyl methylcellulose acetate succinate), polyvinyl acetate phthalate, pH-sensitive methacrylic acid-methacrylate copolymers and shellac. These polymers may be used as a dry powder or an aqueous dispersion. Some commercially available materials that may be used are methacrylic acid copolymers sold under the trademark Eudragit (LI 00, S100, L30D) manufactured by Rhom Pharma, Cellacefate (cellulose acetate phthalate) from Eastman Chemical Co., Aquateric (cellulose acetate phthalate aqueous dispersion) from FMC Corp. and Aqoat (hydroxypropyl methylcellulose acetate succinate aqueous dispersion) from Shin Etsu K.K.
[0031] Both enteric and water insoluble polymers used in forming the membranes are usually plasticized. Representative examples of plasticizers that may be used to plasticize the membranes include triacetin, tributyl citrate, triethyl citrate, acetyl tri-n-butyl citrate diethyl phthalate, castor oil, dibutyl sebacate, acetylated monoglycerides and the like or mixtures thereof. The plasticizer may comprise about 3 to 30 wt. % and more typically about 10 to 25 wt. % based on the polymer. The type of plasticizer and its content depends on the polymer or polymers, nature of the coating system (e.g., aqueous or solvent based, solution or dispersion based and the total solids).
[0032] In general, it is desirable to prime the surface of the particle before applying the pulsatile release membrane coatings or to separate the different membrane layers by applying a thin hydroxypropyl methylcellulose (HPMC) (Opadry Clear) film. While HPMC is typically used, other primers such as hydroxypropylcellulose (HPC) can also be used.
[0033] The membrane coatings can be applied to the core using any of the coating techniques commonly used in the pharmaceutical industry, but fluid bed coating is particularly useful.
[0034] The present invention is applied to multi-dose forms, i.e., drug products in the form of multi-particulate dosage forms (pellets, beads, granules or mini-tablets) or in other forms suitable for oral administration.
[0035] The following Examples illustrate the dosage formulations of the invention.
EXAMPLES
[0036] Pulsatile Release capsules of nizatidine, a novel histamine H 2 receptor antagonist, comprise a mixture of two sets of beads: The first set is referred to as immediate release (IR) Beads and are designed to provide a loading dose by releasing all of the nizatidine within the first hour, preferably within the first 30 minutes. The second set is referred to as the Timed Pulsatile Release (TPR) Beads and are designed to release nizatidine in a ‘burst’ over a period of 2 hours after about 2-4 hour lag time. The TPR Beads are produced by applying an outer layer of pulse coating (comprising a blend of an enteric polymer such as HPMCP and a water insoluble polymer such as ethylcellulose) on IR Beads. The two sets of beads when filled into capsule shells at an appropriate ratio will produce the target circadian rhythm release profile required for maintaining drug plasma concentrations at potentially beneficial level when taken orally twice a day, after breakfast and dinner.
Example 1
[0037] Nizatidine (5787.7 g) was slowly added to an aqueous solution of hydroxypropylcellulose such as Klucel LF (643.1 g) and mixed well. # 25-30 mesh sugar spheres (3700 g) were coated with the drug suspension in a Glatt fluid bed coater. The drug containing particles were dried, and a seal coat of Opadry Clear (2% w/w) was first applied. These drug containing IR Beads were provided with an outer membrane by spraying a solution of 1:1 blend of ethylcellulose and HPMCP plasticized with diethyl phthalate in 98/2 acetone/water in a fluid bed coater for a weight gain of approximately 39-40%. The coated particles are cured at 60° C. until the polymers were coalesced to produce TPR Beads. Pulsatile Release Nizatidine Capsules, 150 mg, were manufactured by filling 75 mg IR Beads and 75 mg TPR Beads into size 0 hard gelatin capsules using a MG Futura capsule filling equipment. The drug release testing was performed using USP Apparatus 2 (Paddles @ 50 rpm) in 0.1N HCl for 2 hours and subsequently at pH 6.8. The release profiles generated from Pulsatile Release Capsules comprising TPR Beads with different membrane coating levels are presented in FIG. 2.
Example 2
[0038] Nizatidine (168 kg) was slowly added to an aqueous solution of hydroxypropylcellulose such as Klucel LF (18.6 kg) and mixed well. # 25-30 mesh sugar spheres (107.4 kg) were coated with the drug suspension in a Glatt fluid bed coater, equipped with a 32″ bottom spray Wurster insert. The drug containing particles were dried, and a seal coat of Opadry Clear (2% w/w) was first applied and dried in the Glatt fluid bed unit as a precautionary measure to drive off excessive surface moisture. These drug containing IR Beads were provided with an outer membrane by spraying a solution of 1:1 blend of ethylcellulose and HPMCP plasticized with diethyl phthalate in 98/2 acetone/water in a fluid bed coater for a weight gain of approximately 39-40%. The coated particles are cured at 60° C. for 4 hours to produce TPR Beads (batch size:300 kg). Pulsatile Release Nizatidine Capsules, 150 mg, were manufactured by filling 75 mg IR Beads and 75 mg TPR beads into size 0 hard gelatin capsules. The drug release profile is shown in FIG. 3.
Example 3
[0039] In order to assess the type of in vitro release profile needed to achieve a circadian rhythm effect under in vivo conditions, a modeling exercise was performed using the pharmacokinetic parameters for nizatidine. A diurnal variation in the pharmaco-kinetics of nizatidine has been reported by Jamali, A. Thomson, P. Kirdeikis, M. Tavernini, L. Zuk, R. Marriage, R. Simpson, and V. Mahachai (the reference entitled, “Diurnal variation in the pharmaco-kinetics of Nizatidine in healthy volunteers and in patients with peptic ulcer disease”, Journal of Clinical Pharmacology 35:1071-1075, 1995 is incorporated in its entirety). A pharmaco-kinetic modeling was done separately to try to mimic both night time and day time results individually. Mean serum concentrations of nizatidine achieved in healthy volunteers were taken from the same literature. Theoretical in vitro dissolution profile (FIG. 4) as well as in vivo serum levels achieved during nighttime and daytime dosing, were simulated using the pharmaco-kinetic models developed. The advantages of a pulsatile dosage form are evident in attached FIG. 5 that compares simulated serum levels achieved with an immediate release dose of nizatidine versus the proposed pulsatile dose, being orally administered at (a) nighttime and (b) daytime. The proposed dosage form is seen to give two pulses about 3.5-4.0 hours apart, maintaining an acceptable serum concentration for about 6.0-8.0 hours in the body, irrespective of whether night time or day time dosing is considered. Thus, the presence of the TPR portion should ideally sustain enough drug in the body right around midnight when literature has reported a circadian rhythm to gastric acid secretion and increased severity of symptoms associated with GERD.
[0040] Clinical supplies, nizatidine pulsatile Capsules, 150 mg, comprising of 75 mg IR and 75 mg TPR Beads were manufactured following Example 1, by filling hard gelatin size# 0 capsules. FIG. 6 shows the plasma concentration profile (a bimodal display) achieved in a healthy volunteer when dosed after dinner.
Example 4
[0041] The nizatidine pulsatile Capsules prepared in Example 3 were utilized in two randomized, double-blind, comparative, multiple dose efficacy studies. The clinical efficacy studies included a total of 428 subjects with GERD who were treated with the subject nizatidine Capsules and 215 treated with placebo. For the purpose of summarizing the nizatidine Capsules efficacy data, the two randomized, double-blind, comparative, multiple dose efficacy studies were conducted under identical protocols during the same time period, and identical case report forms were used for both studies. Clinical studies were designed to assess the safety and efficacy of nizatidine Capsules 150 mg bid, nizatidine Capsules 300 mg and placebo in adult subjects with clinical symptom and endoscopic evidence of erosive and ulcerative GERD. Subjects meeting the entry criteria were randomized to receive one of the three treatments and began taking study medication in the evening on Day 0. Study medication was taken for up to 12 weeks, with follow-up visits at weeks 3,6 and 12.
[0042] The results of the combined efficacy analyses indicated that clinically and statistically significant healing of erosive esophagitis with associated symptom relief was produced by the nizatidine Capsules administered either as individual doses (150 mg bid) or as a single nightly dose of 300 mg. For the nizatidine Capsule 150 mg bid, statistically significant and clinically meaningful overall healing was also demonstrated. Subjects treated with nizatidine Capsules bid had a significantly greater mean change from baseline in their endoscopy grade and there was a notable trend toward efficacy in the proportions of subjects who had >2 points improvement in baseline endoscopy grade compared to those treated with placebo. Subjects treated with nizatidine Capsules 300 mg qd also had a greater mean change from baseline in their endoscopy grade. Based on subject rated nighttime symptom scores, statistically significant and clinically meaningful night time relief of heartburn, regurgitation and retrosternal pain was demonstrated during the first week of treatment for both nizatidine Capsules 150 mg bid and nizatidine Capsules 300 mg qd. Based on Investigator-rated night time symptom scores, treatment with nizatine Capsules 150 mg bid was significantly superior to placebo at Week 12 for heartburn and regurgitation, and there a trend toward efficacy for retrosternal pain. Treatment with nizatidine Capsules 300 mg qd was significantly superior to placebo at Week 12 for heartburn, regurgitation and retrosternal pain. Based on Investigator rated daytime symptom scores, treatment with nizatidine Capsules 150 mg bid was significantly superior to placebo at Week 12 for daytime heartburn and retrosternal pain. Nizatidine Capsules 300 mg qd was significantly superior to placebo at Week 12 for daytime retrosternal pain. Subjects treated with nizatidine Capsules 150 mg bid used significantly less antacid tablets per day than did those treated with placebo (P<0.001).
[0043] The study conclusion was as follows:
[0044] “Overall, in subjects with endoscopically proven GERD, nizatidine CR administered in doses of either 150 mg bid or 300 mg qd was effective in healing esophageal erosions and in relieving GERD symptoms.”
Example 5
[0045] Cimetidine was slowly added to an aqueous solution of polyvinylpyrrolidone and mixed well. # 25-30 mesh sugar spheres were coated with drug solution in a Glatt fluid bed granulator. The drug containing pellets were dried, and a seal coat of Opadry Clear (2% w/w) was first applied. The inner polymer coating was applied to the active particles by spraying an aqueous dispersion of ethylcellulose (aquacoat® ECD-30 with dibutyl sebacate as the plasticizer to produce intermediate release (IntR) Beads. An outer coating formulation was prepared by mixing two separate aqueous dispersions of Eudragit L30D plasticized with acetyl tri-n-butyl citrate and Aquacoat ECD-30 (an aqueous dispersion of ethylcellulose) plasticized with dibutyl sebacate. The combined coating formulation was sprayed onto the ethylcellulose coated IntR Beads. The coated particles are cured at 60° C. until the polymers were coalesced to produce TSR Beads. The finished SR and TSR Beads were tested for in vitro dissolution properties using USP Dissolution Apparatus 2 at a paddle speed of 50 rpm. The beads were dissoluted using a three-stage dissolution medium, i.e., first 2 hours in 0.1 N HCl, next 2 hours at pH 4.0 and then at pH 6.8 for additional 14 hours, the pH of the medium being changed by adding a pH modifier. The results obtained are presented in Table 1. The dissolution results show that there is a lag time of about four hours followed by sustained release occurring over a period of 12-14 hours for the TSR Beads.
TABLE 1 Dissolution Data for SR and TSR Beads of Example 4 TSR Beads SR Beads SR Coating (1.8% w/w)/ Time, hours SR Coating (1.8% w/w) TSR Coating (15% w/w) 1.0 0.2 0 2.0 0.1 0 3.0 0.5 0.5 4.0 0.2 0.4 5.0 15 10 6.0 42 24 8.0 71 47 10.0 85 62 12.0 93 72 14.0 98 78 16.0 103 86 | A unit dosage form, such as a capsule or the like, for delivering drugs into the body in a circadian release fashion comprising one or more populations of drug-containing particles (beads, pellets, granules, etc.) is disclosed. Each bead population exhibits a pre-designed rapid or sustained release profile with or without a predetermined lag time of 3 to 5 hours. Such a circadian rhythm release drug delivery system is designed to provide a plasma concentration—time profile, which varies according to physiological need at different times during the dosing period, i.e., mimicking the circadian rhythm and severity/manifestation of gastric acid secretion (and/or midnight gerd), predicted based on pharmaco-kinetic and pharmaco-dynamic considerations and in vitro/in vivo correlations. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates generally to a display device and more particularly, to a liquid crystal electro-optical modulator and a method of optical modulation.
As information technology continues to evolve, the demands for light modulation in commercial product applications such as c-signature, e-tag, e-booking and smart cards have been increasing in recent years. It is desirable to have an electro-optical modulator that is cost effective and satisfies the commercial product applications.
BRIEF SUMMARY OF THE INVENTION
Examples of the invention may provide an electro-optical modulator and a method of optical modulation.
Examples of the invention may provide an electro-optical modulator that comprises a substrate, a first electrode over the substrate, a second electrode over the first electrode, the first electrode and second electrode being capable of providing an electric field between the first electrode and the second electrode, and a modulating structure between the first electrode and the second electrode, the modulating structure containing at least one liquid crystal cell capable of operating in one of a reflective mode and a transmissive mode under the control of the electrical field.
Examples of the invention may also provide an electro-optical modulator that comprises a first pair of electrodes capable of applying a first electric field, a first liquid crystal cell between two electrodes of the first pair of electrodes and capable of operating in one of a reflective mode and a transmissive mode under the control of the first electrical field, a second pair of electrodes over the first liquid crystal cell, the second pair of electrodes capable of applying a second electric field, and a second liquid crystal cell between two electrodes of the second pair of electrodes and capable of being controlled by the second electrical field.
Some examples of the invention may also provide an electro-optical modulator that comprises a first pair of electrodes capable of applying a first electrical field, a first modulating structure between two electrodes of the first pair of electrodes, the first modulating structure including a first liquid crystal cell capable of operating in one of a reflective mode and a transmissive mode under the control of the first electrical field, a second pair of electrodes over the first liquid crystal cell, the second pair of electrodes capable of applying a second electrical field, and a second modulating structure between two electrodes the second pair of electrodes, the second modulating structure including a second liquid crystal cell capable of operating in one of an isotropic mode and an anisotropic mode under the control of the second electrical field.
Examples of the invention may also provide a method of optical modulation that comprises providing a modulator comprising a pair of electrodes, a modulating structure formed between the pair of electrodes, and a liquid crystal cell formed in the modulating structure capable of operating in one of a first mode and a second mode, operating the liquid crystal cell in the first mode, applying an electrical field between the pair of electrodes, and switching the liquid crystal cell from the first mode to the second mode.
Examples of the invention may also provide a method of optical modulation that comprises providing a modulator including a first pair of electrodes, a first liquid crystal cell formed between the first pair of electrodes capable of operating in one of a reflective mode and a transmissive mode, a second pair of electrodes formed over the first liquid crystal cell, and a second liquid crystal cell formed between the second pair of electrodes, operating the first liquid crystal cell in one of the reflective mode and the transmissive mode, and applying an electrical field between at least one of the first pair of electrodes or the second pair of electrodes.
Some examples of the invention may also provide a method of optical modulation that comprises providing a modulator including a first pair of electrodes, a first liquid crystal cell formed between the first pair of electrodes capable of operating in one of a reflective mode and a transmissive mode, a second pair of electrodes formed over the first liquid crystal cell, and a second liquid crystal cell formed between the second pair of electrodes capable of operating in one of an isotropic mode and an anisotropic mode, operating the first liquid crystal cell in one of the reflective mode and the transmissive mode, operating the second liquid crystal cell in one of the isotropic mode and the anisotropic mode, and applying an electrical field between at least one of the first pair of electrodes or the second pair of electrodes.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings examples consistent with the invention. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.
In the drawings:
FIGS. 1A to 1D are cross-sectional diagrams of electro-optical modulators consistent with examples of the present invention;
FIGS. 2A to 2C are diagrams each illustrating a method for operating an electro-optical modulator consistent with an example of the present invention;
FIG. 3A is a cross-sectional diagram of an electro-optical modulator consistent with another example of the present invention;
FIG. 3B is a cross-sectional diagram of an electro-optical modulator consistent with still another example of the present invention;
FIG. 4A is a cross-sectional diagram of an electro-optical modulator consistent with an example of the present invention;
FIG. 4B is a cross-sectional diagram of an electro-optical modulator consistent with another example of the present invention;
FIG. 5A is a diagram illustrating a method for operating the electro-optical modulator illustrated in FIG. 4A ;
FIG. 5B is a diagram illustrating another method for operating the electro-optical modulator illustrated in FIG. 4A ;
FIG. 5C is a diagram illustrating a method for operating an electro-optical modulator consistent with an example of the present invention;
FIG. 5D is a diagram illustrating another method for operating the electro-optical modulator illustrated in FIG. 5C ;
FIG. 6A is a cross-sectional diagram of an electro-optical modulator consistent with an example of the present invention;
FIG. 6B is a cross-sectional diagram of an electro-optical modulator consistent with another example of the present invention;
FIG. 7A is a diagram illustrating a method for operating the electro-optical modulator illustrated in FIG. 6A ; and
FIG. 7B is a diagram illustrating another method for operating the electro-optical modulator illustrated in FIG. 6A .
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the present embodiments of the 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 portions.
FIGS. 1A to 1D are cross-sectional diagrams of electro-optical modulators 10 - 1 to 10 - 4 consistent with examples of the present invention. Referring to FIG. 1A , the electro-optical modulator 10 - 1 includes a substrate 11 , a first conductive layer 12 - 1 , a modulating structure 13 - 1 , a liquid crystal cell 14 and a second conductive layer 12 - 2 . The substrate 11 is optically transparent and may be made of polymer materials such as polyethylenterephthalate (PET), polycarbonate (PC) and polyethersulfone (PES). In one example, the thickness of the substrate 11 may be approximately 125 micrometers (μm), but this may vary for various applications. The first conductive layer 12 - 1 , formed over the substrate 11 , serves as a first electrode of the electro-optical modulator 10 - 1 . The first conductive layer 12 - 1 may be a transparent conductive layer, such as a layer of indium tin oxide (ITO) or indium zinc oxide (IZO) having a thickness of approximately 0.1 to 0.2 μm, or a conducting polymer having a thickness of approximately 1 μm in some examples. The modulating structure 13 - 1 includes a plurality of modulating units 130 and is made of a polymer material such as fish gel and photograph gel. The height of the modulating structure 13 - 1 may range from approximately 5 to 15 μm in one example. The liquid crystal cell 14 includes a plurality of cell units 14 - 1 , each of which may include a mixture of liquid crystal molecules 15 and fine particles 16 . The weight percentage of the fine particles 16 in a cell unit 14 - 1 ranges from approximately 0.1% to 20%. Each of the plurality of cell units 14 - 1 corresponds to one of the plurality of modulating units 130 . Specifically, each of the plurality of modulating units 130 functions to serves as a containment device that encapsulates or confines a corresponding one of the plurality of cell units 14 - 1 . The second conductive layer 12 - 2 , formed over the modulating structure 13 - 1 , serves as a second electrode of the electro-optical modulator 10 - 1 . The second conductive layer 12 - 2 includes a similar material to the first conductive layer 12 - 1 , and has substantially the same thickness as the first conductive layer 12 - 1 .
In the present example, the modulating structure 13 - 1 is formed by a conventional microencapsulating process, which encapsulates droplets of liquid crystal molecules and fine particles in polymer walls.
Referring to FIG. 1B , the electro-optical modulator 10 - 2 includes a similar structure to the electro-optical modulator 10 - 1 illustrated in FIG. 1A except a modulating structure 13 - 2 . The modulating structure 13 - 2 includes a plurality of polymer banks 131 and a sealing layer 132 formed over the plurality of polymer banks 131 . Each of the plurality of polymer banks 131 and the sealing layer 132 defines a modulating unit (not numbered) corresponding to one of the plurality of cell units 14 - 1 . The modulating structure 13 - 2 may be formed by a conventional photolithography or molding process.
Referring to FIG. 1C , the electro-optical modulator 10 - 3 includes a similar structure to the electro-optical modulator 10 - 1 illustrated in FIG. 1A except a modulating structure 13 - 3 . The modulating structure 13 - 3 includes a plurality of polymer walls 133 . Each of the plurality of polymer walls 133 and the second conductive layer 12 - 2 defines a modulating unit (not numbered) corresponding to one of the plurality of cell units 14 - 1 . The modulating structure 13 - 3 may be formed by a conventional photo-induced phase separation process.
Referring to FIG. 1D , the electro-optical modulator 10 - 4 includes a similar structure to the electro-optical modulator 10 - 1 illustrated in FIG. 1A except a modulating structure 13 - 4 . The modulating structure 13 - 4 includes a plurality of modulating units 134 . Each of the plurality of modulating units 134 corresponds to one of the plurality of cell units 14 - 1 . The modulating structure 13 - 4 may be formed by a conventional interfacial polymerization process.
FIGS. 2A to 2C are diagrams each illustrating a method for operating an electro-optical modulator consistent with an example of the present invention. Referring to FIG. 2A , as an example of the electro-optical modulator 10 - 1 illustrated in FIG. 1A , the liquid crystal molecules 15 are oriented in a first pattern such that an incident light is reflected back. Specifically, an incident light at the substrate 11 from, for example, a backlight source is reflected by the liquid crystal cell 14 . Similarly, an incident light at the second conductive layer 12 - 2 from, for example, an ambient light source is reflected by the liquid crystal cell 14 . The electro-optical modulator 10 - 1 is said to operate in a reflective mode. The liquid crystal molecules 15 are not necessarily required to center around fine particles 16 as illustrated in FIGS. 1A and 2A . Other patterns that enable the liquid crystal cell 14 to reflect an incident light are also possible.
Referring to FIG. 2B , an electro-optical modulator 20 - 1 includes a similar structure to the electro-optical modulator 10 - 1 illustrated in FIG. 2A except that the liquid crystal molecules 15 are oriented in a second pattern, which allows an incident light to pass the liquid crystal cell 14 . The electro-optical modulator 20 - 1 is said to operate in a transmissive mode. In operation, by applying a suitable electrical field between the first conductive layer 12 - 1 and the second conductive layer 12 - 2 , a reflective-mode modulator such as the modulator 10 - 1 illustrated in FIG. 2A is able to be switched to a transmissive-mode modulator such as the modulator 20 - 1 illustrated in FIG. 2B , and vice versa. The electro-optical modulators 10 - 1 and 20 - 1 respectively illustrated in FIGS. 1A and 2B therefore exhibit bistable properties, which means that an electro-optical modulator may operate in either a first or a second stable state when an external source such as an electrical field is removed. In the present example, the first state refers to the reflective mode and the second state refers to the transmissive mode, and vice versa. In one example consistent with the present invention, the electrical field ranges from several volts per micrometer to several tens of volts per micrometer. The electrical field may be built by applying voltage signals of different amplitudes or applying voltage signals at different frequencies to the first conductive layer 12 - 1 and the second conductive layer 12 - 2 .
Referring to FIG. 2C , an electro-optical modulator 20 - 2 includes a similar structure to the electro-optical modulator 10 - 1 illustrated in FIG. 2A except a liquid crystal cell 24 , a second conductive layer 22 - 1 and a third conductive layer 22 - 2 separated from the second conductive layer 22 - 1 . The liquid crystal cell 24 includes reflective-mode cell units 24 - 1 and transmissive-mode cell units 24 - 2 . In operation, each of the reflective-mode cell units 24 - 1 is able to be switched to the transmissive mode by applying a first electrical field between the first conductive layer 12 - 1 and the second conductive layer 22 - 1 . Similarly, each of the transmissive-mode cell units 24 - 2 is able to be switched to the reflective mode by applying a second electrical field between the first conductive layer 12 - 1 and the third conductive layer 22 - 2 . Skilled persons in the art will understand that the first conductive layer 12 - 1 extends in a first direction, while the second conductive layer 22 - 1 and the third conductive layer 22 - 2 extend in a second direction substantially orthogonal to the first direction. Furthermore, skilled persons in the art will understand that one of the modulating structures 13 - 2 , 13 - 3 and 13 - 4 respectively illustrated in FIGS. 1B , 1 C and 1 D may also be used in the electro-optical modulators 20 - 1 and 20 - 2 as well as the modulating structure 13 - 1 .
FIG. 3A is a cross-sectional diagram of an electro-optical modulator 30 - 1 consistent with another example of the present invention. Referring to FIG. 3A , the electro-optical modulator 30 - 1 includes a similar structure to the electro-optical modulator 20 - 2 illustrated in FIG. 2C except a light absorbing layer 31 . The light absorbing layer 31 , disposed between the liquid crystal cell 24 and the second conductive layer 22 - 1 and the third conductive layer 22 - 2 , is capable of absorbing light transmitting through the liquid crystal cell 24 and in particular, the cell units 24 - 2 . In another example, the light absorbing layer 31 is disposed over the second conductive layer 22 - 1 and the third conductive layer 22 - 2 so that the conductive layers 22 - 1 and 22 - 2 are sandwiched between the liquid crystal cell 24 and the light absorbing layer 31 .
FIG. 3B is a cross-sectional diagram of an electro-optical modulator 30 - 2 consistent with still another example of the present invention. Referring to FIG. 3B , the electro-optical modulator 30 - 2 includes a similar structure to the electro-optical modulator 20 - 2 illustrated in FIG. 2C except a liquid crystal cell 34 . The liquid crystal cell 34 includes a plurality of dichroic dyes 17 in cell units 34 - 1 . The cell units 34 - 1 are capable of absorbing light transmitting through the liquid crystal cell 34 , which otherwise would operate in the reflective mode in the absence of the dichroic dyes 17 .
The electro-optical modulator 30 - 2 further includes a reflector 32 disposed over the first conductive layer 22 - 1 and the second conductive layer 22 - 2 . The reflector 32 is capable of reflecting light transmitting through the liquid crystal cell 34 and in particular, the cell units 24 - 2 . In another example, the reflector 32 is disposed between the conductive layers 22 - 1 , 22 - 2 . and the liquid crystal cell 34 .
FIG. 4A is a cross-sectional diagram of an electro-optical modulator 40 - 1 consistent with an example of the present invention. Referring to FIG. 4A , the electro-optical modulator 40 - 1 includes a first modulator similar to the electro-optical modulator 10 - 1 illustrated in FIG. 1A and a second modulator 45 . The first modulator 10 - 1 includes the first substrate 11 , the first electrode 12 - 1 , the modulating structure 13 - 1 , the first liquid crystal cell 14 and the second electrode 12 - 2 . The second modulator 45 , which functions to serve as a panel of the electro-optical modulator 40 - 1 , may be laminated to the first modulator 10 - 1 . The second modulator 45 includes a second substrate 41 - 1 , a first polarizer 47 - 1 , a third electrode 42 - 1 , spacers 43 , a fourth electrode 42 - 2 , a fifth electrode 42 - 3 , a second liquid crystal cell 44 , a second polarizer 47 - 2 and a third substrate 41 - 2 .
FIG. 4B is a cross-sectional diagram of an electro-optical modulator 40 - 2 consistent with another example of the present invention. Referring to FIG. 4B , the electro-optical modulator 40 - 2 includes a first modulator 46 and a second modulator 48 . The first modulator 46 is similar to the electro-optical modulator 10 - 1 illustrated in FIG. 1A except a first polarizer 46 - 1 , which is disposed to sandwich the first substrate 11 with the first electrode 12 - 1 . The second modulator 48 includes the second electrode 12 - 2 , the spacers 43 , the fourth electrode 42 - 2 , the fifth electrode 42 - 3 , the second liquid crystal cell 44 , the second polarizer 47 - 2 and the third substrate 41 - 2 .
FIG. 5A is a diagram illustrating a method for operating the electro-optical modulator 40 - 1 illustrated in FIG. 4A . Referring to FIG. 5A , assuming that the second liquid crystal cell 44 is a vertically arranged (VA) mode panel and no electrical field is applied between the third electrode 42 - 1 and the fifth electrode 42 - 3 , an incident light at the third substrate 41 - 2 transmitting through the second polarizer 47 - 2 and the second liquid crystal cell 44 is blocked by the first polarizer 47 - 1 . As a comparison, if an electrical field is applied between the third electrode 42 - 1 and the fourth electrode 42 - 2 , changing the orientation of the liquid crystal molecules in the second liquid crystal cell 44 , an incident light at the third substrate 41 - 2 transmitting through the second liquid crystal cell 44 is reflected by the first liquid crystal cell 14 operating in the reflective mode. The reflected light transmits through the second liquid crystal cell 44 to a viewer 55 at the third substrate 41 - 2 .
FIG. 5B is a diagram illustrating another method for operating the electro-optical modulator 40 - 1 illustrated in FIG. 4A . Referring to FIG. 5B , a first electrical field is applied between the first electrode 12 - 1 and the second electrode 12 - 2 to switch the first modulator 10 - 1 to the transmissive mode. If no electrical field is applied between the third electrode 42 - 1 and the fifth electrode 42 - 3 , an incident light at the first substrate 11 transmitting through the first liquid crystal cell 14 , the first polarizer 47 - 1 and the second liquid crystal cell 44 is blocked by the second polarizer 47 - 2 . As a comparison, if a second electrical field is applied between the third electrode 42 - 1 and the fourth electrode 42 - 2 , changing the orientation of the liquid crystal molecules in the second liquid crystal cell 44 , an incident light at the first substrate 11 transmitting through the first liquid cell 14 and the second liquid crystal cell 44 to the viewer 55 at the third substrate 41 - 2 .
FIG. 5C is a diagram illustrating a method for operating an electro-optical modulator 50 consistent with an example of the present invention. Referring to FIG. 5C , the electro-optical modulator 50 includes a similar structure to the electro-optical modulator 40 - 1 illustrated in FIG. 5A except a second modulator 56 , which is a twisted nematic (TN) mode panel. In operation, if no electrical field is applied between the third electrode 42 - 1 and the fifth electrode 42 - 3 , an incident light at the third substrate 41 - 2 transmitting through the second polarizer 47 - 2 and a second liquid crystal cell 54 is blocked by the first polarizer 47 - 1 . As a comparison, if an electrical field is applied between the third electrode 42 - 1 and the fourth electrode 42 - 2 , changing the orientation of the liquid crystal molecules in the second liquid crystal cell 54 , an incident light at the third substrate 41 - 2 transmitting through the second liquid crystal cell 54 is reflected by the first liquid crystal cell 14 operating in the reflective mode. The reflected light transmits through the second liquid crystal cell 54 to a viewer 55 at the third substrate 41 - 2 .
FIG. 5D is a diagram illustrating another method for operating the electro-optical modulator 50 illustrated in FIG. 5C . Referring to FIG. 5D , a first electrical field is applied between the first electrode 12 - 1 and the second electrode 12 - 2 to switch the first modulator 10 - 1 to the transmissive mode. If no electrical field is applied between the third electrode 42 - 1 and the fifth electrode 42 - 3 , an incident light at the first substrate 11 transmitting through the first liquid crystal cell 14 , the first polarizer 47 - 1 and the second liquid crystal cell 54 is blocked by the second polarizer 47 - 2 . As a comparison, if a second electrical field is applied between the third electrode 42 - 1 and the fourth electrode 42 - 2 , changing the orientation of the liquid crystal molecules in the second liquid crystal cell 54 , an incident light at the first substrate 11 transmitting through the first liquid cell 14 and the second liquid crystal cell 54 to the viewer 55 at the third substrate 41 - 2 .
FIG. 6A is a cross-sectional diagram of an electro-optical modulator 60 - 1 consistent with an example of the present invention. Referring to FIG. 6A , the electro-optical modulator 60 - 1 includes a first modulator similar to the electro-optical modulator 10 - 1 illustrated in FIG. 1A and a second modulator 65 . The first modulator 10 - 1 includes the first substrate 11 , the first electrode 12 - 1 , the first modulating structure 13 - 1 , the first liquid crystal cell 14 and the second electrode 12 - 2 . The second modulator 65 , which functions to serve as a panel of the electro-optical modulator 60 - 1 , may be laminated to the first modulator 10 - 1 . The second modulator 65 includes a second substrate 61 - 1 , a first polarizer 67 - 1 , a third electrode 62 - 1 , a second modulating structure 63 , a fourth electrode 62 - 2 , a fifth electrode 62 - 3 , a second liquid crystal cell 64 , a second polarizer 67 - 2 and a third substrate 61 - 2 .
The first liquid crystal cell 14 is operable in a reflective mode or a transmissive mode. In one aspect, the first liquid crystal cell 14 includes inorganic fine particles such as silica particles and positive liquid crystal molecules. In another aspect, the first liquid crystal cell 14 includes organic fine particles such as polystyrene or divinylbenzene (DVB) copolymer particles and positive liquid crystal molecules. The second liquid crystal cell 64 exhibits an isotropic optical feature (hereinafter “isotropic mode”) in the absence of an electrical field, or exhibits an anisotropic optical feature (hereinafter “anisotropic mode”) in the presence of an electrical field. In the isotropic mode, the optical property of liquid crystal molecules is independent of direction. In contrast, in the anisotropic mode, the optical property of liquid crystal molecules is dependent of direction. In one aspect, the second liquid crystal cell 64 includes carbon nanotube (CNT) particles and negative liquid crystal molecules. In another aspect, the second liquid crystal cell 64 includes carbon 60 Fullerene particles and negative liquid crystal molecules.
FIG. 6B is a cross-sectional diagram of an electro-optical modulator 60 - 2 consistent with another example of the present invention. Referring to FIG. 6B , the electro-optical modulator 60 - 2 includes a first modulator 66 and a second modulator 68 . The first modulator 66 is similar to the electro-optical modulator 10 - 1 illustrated in FIG. 1A except a first polarizer 66 - 1 , which is disposed to sandwich the first substrate 11 with the first electrode 12 - 1 . The second modulator 68 includes the second electrode 12 - 2 , the second modulating structure 63 , the fourth electrode 62 - 2 , the fifth electrode 62 - 3 , the second liquid crystal cell 64 , the second polarizer 67 - 2 and the third substrate 61 - 2 .
FIG. 7A is a diagram illustrating a method for operating the electro-optical modulator 60 - 1 illustrated in FIG. 6A . Referring to FIG. 7A , if no electrical field is applied between the third electrode 62 - 1 and the fifth electrode 62 - 3 , an incident light at the third substrate 61 - 2 transmitting through the second polarizer 67 - 2 and the second liquid crystal cell 64 is blocked by the first polarizer 67 - 1 . As a comparison, if an electrical field is applied between the third electrode 62 - 1 and the fourth electrode 62 - 2 to switch the second liquid crystal cell 64 from the isotropic mode to the anisotropic mode, an incident light at the third substrate 61 - 2 transmitting through the second liquid crystal cell 64 is reflected by the first liquid crystal cell 14 operating in the reflective mode. The reflected light transmits through the second liquid crystal cell 64 to the viewer 55 at the third substrate 61 - 2 .
FIG. 7B is a diagram illustrating another method for operating the electro-optical modulator 60 - 1 illustrated in FIG. 6A . Referring to FIG. 7B , a first electrical field is applied between the first electrode 12 - 1 and the second electrode 12 - 2 to switch the first modulator 10 - 1 to the transmissive mode. If no electrical field is applied between the third electrode 62 - 1 and the fifth electrode 62 - 3 , an incident light at the first substrate 11 transmitting through the first liquid crystal cell 14 , the first polarizer 67 - 1 and the second liquid crystal cell 64 is blocked by the second polarizer 67 - 2 . As a comparison, if a second electrical field is applied between the third electrode 62 - 1 and the fourth electrode 62 - 2 to switch the second liquid crystal cell 64 from the isotropic mode to the anisotropic mode, an incident light at the first substrate 11 transmitting through the first liquid cell 14 and the second liquid crystal cell 64 to the viewer 55 at the third substrate 61 - 2 .
It will be appreciated by those skilled in the art that changes could be made to one or more of the examples described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular examples disclosed, but it is intended to cover modifications within the scope of the present invention as defined by the appended claims.
Further, in describing certain illustrative examples of the present invention, the specification may have presented the method and/or process of the present invention as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. As one of ordinary skill in the art would appreciate, other sequences of steps may be possible. Therefore, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. In addition, the claims directed to the method and/or process of the present invention should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the present invention. | An electro-optical modulator includes a substrate, a first electrode over the substrate, a second electrode over the first electrode, the first electrode and second electrode being capable of providing an electric field between the first electrode and the second electrode, and a modulating structure between the first electrode and the second electrode, the modulating structure containing at least one liquid crystal cell capable of operating in one of a reflective mode and a transmissive mode under the control of the electrical field. | 6 |
BACKGROUND OF THE INVENTION
The compressive load carrying capacity of a body or layer of elastomeric material may be increased several hundred percent by incorporating a plurality of spaced, parallel laminae fabricated of nonextensible material and oriented generally perpendicular to the direction of the compressive load. The laminae increase the compressive load carrying capacity of the elastomeric material by restricting the ability of the material to deflect or bulge in directions transverse to the direction of the compressive load. Specifically, the laminae effectively subdivide the force-free or non-loaded surfaces that extend between the loaded surfaces of the elastomeric material. When loaded in compression, therefore, the material cannot deflect along its force-free surfaces in a large bulge that is continuous between the loaded surfaces of the material. Instead, the "subdivided" force-free surfaces can only deflect in a series of distinct and separate smaller bulges.
The total volume of material in the smaller bulges of a laminated elastomeric structure is significantly less than in the large single bulge that appears in an unlaminated body of elastomeric material. Thus, for a given load, the laminated structure exhibits a smaller change or reduction in height or length than would be experienced by the same body of elastomer without laminae. Since the height or length reduction is a critical parameter for practical use of elastomeric material under compressive loads, the compressive load carrying capacity of the material is increased. At the same time, the ability of the material to yield in shear or torsion in directions parallel to the laminations or transverse to the direction of the compressive load is substantially unaffected.
The characteristics of laminated elastomeric bearings have resulted in the commercial acceptance of the bearings for a variety of applications. Nonetheless, the basic design concept on which the bearings rely also has an adverse effect on their acceptability. In particular, to increase the compressive load carrying capacity of a laminated bearing, while maintaining a specified torsional or translational shear deflection capability, the number of non-extensible laminations must be increased. The non-extensible material is often a high-strength and expensive metal, such as titanium or stainless steel. For many bearing configurations, the metal must be carefully machined, at extra cost. In addition to the expense of the nonextensible laminations, they represent a significant portion, if not substantially all, of the weight of a laminated bearing. The increased cost and weight of higher capacity laminated bearings have thus placed limitations on their commercial acceptance.
Another approach to increasing the compressive load carrying capacity of a layer of elastomeric material is to restrict the ability of the material to bulge by enclosing the force-free surfaces of the material in a circumferential shell or housing. Rosenzweig U.S. Pat. No. 2,359,942 and Wallerstein, Jr. U.S. Pat. No. 3,081,993 both describe and illustrate resilient mountings in which the force-free surfaces of a body of elastomer are partially or wholly enclosed by a bulge-restricting shell. In the Rosenzweig mounting, the body of elastomer is completely encased in a rigid metal housing. Nonetheless, the elastomer is free to bulge to a limited extent because of an annular body of resilient material interposed between the body of elastomer and the rigid housing. The intermediate resilient material is significantly more compressible than the elastomer (i.e., it has a lower Poisson's ratio), and can be compressed by, and to accommodate, bulging of the elastomer. In the Wallerstein, Jr. mounting, a relatively wide, split metal band encircles a cylindrical body of elastomer. A garter spring normally prevents the ends of the band from separating. Thus, when the mounting is loaded in compression, the band initially prevents the central longitudinal portion of the body from bulging. When a predetermined compressive load is reached, however, the elastomer forces the split band open against the resistance of the garter spring. The mounting thereafter deflects or bulges at an increased rate for higher compressive loads.
Although both the Rosenzweig mounting and the Wallerstein, Jr. mounting may be effective in increasing the compression load carrying capacity of a body of elastomeric material, neither mounting is intended to accommodate significant torsional or translational shear motions. In the Wallerstein, Jr. mounting, for example, translational shearing movements between the rigid end members 2 and 3 that are secured to the body of elastomer can only be accommodated by shearing of the unconfined end portions of the elastomer. Similarly, the frictional engagement between the split band and the exterior surface of the elastomeric body effectively prevents the confined central portion of the elastomeric body from deflecting in torsional shear. The Rosenzweig mounting is constructed such that translational movements between a supported and a supporting member stress the elastomer of the mounting in compression, rather than shear. Relative rotation between the supported and supporting members will be strongly resisted by the friction developed between the body of elastomer and the adjacent, radially extending metal parts. A particular problem will be the friction developed beween the elastomer and the lower supporting washer 6 and the related friction developed between the washer 6 and the abutment ring 5.
The use of a bulge-restraining housing or shell in an elastomeric mounting that is intended to accommodate both compressive and torsional loads has been suggested by Irwin U.S. Pat. No. 3,504,905. In the mountings or bearings of the Irwin patent, particularly the bearings of FIGS. 7, 8 and 9, an openwork mesh of wire, for example, encloses the circumference of a laminated elastomeric bearing. The mesh impedes, but does not prevent, the lateral extrusion or bulging of the elastomer from between the nonextensible laminae. At the same time, the openwork structure of the mesh permits parallel movements between adjacent woof strands so as to accommodate twisting or torsional loading of the bearing.
SUMMARY OF THE INVENTION
The present invention is directed to a compression mounting in which at least a portion of an elastomeric body is completely enclosed so that it cannot freely expand circumferentially in response to compressive loads. The shell that encloses the body can be flexed in torsion, however, so as to permit the mounting to accommodate torsional loads. According to the invention, a compression mounting comprises a body of elastomer and a pair of load-transmitting devices that engage and cover at least parts of two opposed and spaced apart surfaces of the body of elastomer. The two load-transmitting devices are disposed and configured to expose a circumferential surface of the elastomeric body. A shell completely covers and encloses at least a circumferential portion of the exposed surface of the elastomeric body. The shell includes a filamentary structure that provides a plurality of substantially parallel and juxtaposed filament portions oriented to circumscribe the exposed circumferential surface. The filament portions are less extensible than the elastomer of the elastomeric body. A matrix material encases the filament portions and flexibly bonds adjacent filament portions to one another in substantially parallel relationship. The shell snugly fits the surface of the elastomeric body and, because of the filament portions, is more resistant to circumferential expansion than the elastomeric body. The shell thus impedes, at least, the circumferential expansion (i.e., bulging) of the enclosed portion of the exposed surface of the body of elastomer. Such a restriction on the ability of the elastomer to deflect in response to compressive loads applied through the load-transmitting devices increases the compressive load carrying capability of the mounting. Since adjacent filament portions are flexibly bonded together by the matrix material, they can move in parallel planes relative to each other so as to permit the shell and the mounting to deflect in response to torsional loads.
In a preferred embodiment of the invention, each load-transmitting device includes a rigid cover plate that engages and covers the corresponding surface of the body of elastomer. The shell completely covers all of the exposed circumferential surface of the body of elastomer so that the shell and the load-transmitting devices cooperate to cover all exterior surfaces of the body of elastomer. The shell is also substantially nonextensible in a circumferential direction as compared to the body of elastomer. The preferred embodiment of the invention thus permits torsional flexibility of the mounting while simultaneously maximizing the compressive load carrying capability of the mounting.
The filamentary structure of the inventive mounting is preferably formed by a single continuous strand fabricated of a multiplicity of filaments oriented lengthwise of the strand. The strand is helically wound in a plurality of turns around the body of elastomer. The juxtaposed filament portions of the shell thus include both adjacent portions of distinct filaments in the strand and any adjacent turns of an individual filament. The matrix material encases each individual turn of the strand and preferably bonds the entire shell to the body of elastomer. The body of elastomer may be cylindrical in shape and its ends may be bonded to the rigid cover plates of the load-transmitting devices. If the load-transmitting devices are disposed at opposite ends of the body of elastomer, each device includes a flange extending laterally beyond the side edges of the body of elastomer so as to engage and support the shell adjacent the ends of the body.
BRIEF DESCRIPTION OF THE DRAWING
For a better understanding of the invention, reference may be made to the following description of three exemplary embodiments, taken in conjunction with the figures of the accompanying drawing, in which:
FIG. 1 is a side sectional view of a compression mounting according to the present invention;
FIG. 2 is a plan sectional view of the mounting of FIG. 1, taken along view line 2--2 of FIG. 1;
FIG. 3 is a partial side sectional view of a modified version of the mounting of FIGS. 1 and 2; and
FIG. 4 is a plan view, partly in section, of another embodiment of a compression mounting according to the present invention.
DESCRIPTION OF EMBODIMENTS
FIG. 1 of the drawing illustrates a compression mounting 10 according to the present invention. The mounting 10 includes a generally cylindrical body of elastomer 12 and a pair of load-transmitting cover assemblies 14 and 16, one at each end of the elastomeric body. The cover assembly 14 includes a circular, rigid cover plate 18 that completely covers and is bonded to an adjacent end of body of elastomer 12. Projecting from the center of the plate 18 is a threaded shaft 20 over which is placed an annular, flat support plate 22 of larger diameter than the cover plate 18. The support plate 22 is held in place by a washer 24 and a hex nut 26 threaded on the end of the shaft 20. The cover assembly 16 is identical to the assembly 14. A threaded shaft 30 projects from the center of a rigid, circular end plate 28. An annular support plate 32 is carried on the threaded shaft 30 and a washer 34 and a hex nut 36 secure the support plate 32 on the shaft 30.
Since the cover assemblies 14 and 16 are disposed at opposite ends of the body of elastomer 12, the annular circumferential surface 38 of the elastomeric body is exposed between the two cover assemblies. The circumferential surface 38 is completely enclosed and covered, however, by an annular shell 40. The shell 40 includes a filamentary structure that provides a multiplicity of substantially parallel and juxtaposed filament portions oriented to circumscribe the circumferential surface 38. The filamentary structure preferably results from helically winding a continuous strand of fibrous or filamentous material about the body of elastomer 12. As will become apparent, the fibrous material should preferably be a high strength and high Young's modulus material, such as graphite fibers, Kevlar fibers, or glass fibers. Such a material will be substantially nonextensible as compared to the body of elastomer 12. As an example, carbon fibers may have a Young's modulus of 30-75 × 10 6 psi, while natural rubber may have a Young's modulus of 100-2000 psi. The helically wound strand may be either a single continuous filament or a multiplicity of filaments oriented generally in a single direction (i.e., lengthwise of the strand). In the case of a single filament strand, the adjacent turns of the filament will define the desired parallel and juxtaposed filament portions. The desired filament portions will be provided in a multiple filament strand by the adjacent portions of distinct filaments and by adjacent turns of any single filament. A multiple filament strand is preferred because the filaments in adjacent windings or turns 42 of the strand will tend to intermingle and make the boundaries between adjacent turns less distinct. Thus, although FIG. 1 of the drawing illustrates sharply defined windings or turns 42 for purposes of facilitating an explanation of the invention, the windings should preferably be indistinguishable. The intermingling of filaments that occurs with a multiple filament strand should not be such as to disrupt the substantial parallelism of the filaments.
The strand of fibrous material is coated with a liquid elastomeric coating prior to being wound around the elastomeric body 12. Suitable coatings include Chemglaze M-313 polyurethane coating, Adiprene polyurethane, and a combination of Chemglaze M-313 polyurethane and Poly B-D polymer. Coatings that will have a low Young's modulus when cured are preferred. Prior to coating a carbon fiber strand, in particular, the carbon filaments should be coated with a suitable sizing to reduce fraying and to enhance the adhesion between the filaments and the elastomeric coating. When the winding process is completed, the elastomeric coating is allowed to cure to form a flexible matrix material. The matrix material encases and embeds each individual turn or winding 42, and preferably each individual filament. The windings 42 of the strand are thus flexibly bonded to each other, as are adjacent individual filaments. The matrix material also bonds the radially innermost run of windings 42 to the circumferential surface 38 of the body of elastomer 12 and to the outer edges of the cover plates 18 and 28. The bond between the windings 42 and the surface 38 may be enhanced by applying any conventional elastomer adhesive to the surface 38 prior to winding. As an alternative, the windings 42 may be bonded just to the edges of the cover plates 18 and 28, and not to the surface 38 of the elastomeric body 12. Opposite ends of the shell 40, as shown in FIG. 1, are supported by the annular support plates 22 and 32 of the cover assemblies 14 and 16, respectively.
When constructed as shown in FIG. 1 of the drawing, the mounting 10 can accommodate substantial, axially directed, compressive loads applied through the cover assemblies 14 and 16. A compressive load may be applied, in the direction of the arrows 44 and 46, by securing the threaded shafts 20 and 30 to a supported member (not shown) and a supporting member (not shown), respectively. The compressive load is transmitted to the body of elastomer through the threaded shafts 20 and 30 and the rigid end plates 18 and 28. The body of elastomer 12 attempts to bulge or expand circumferentially in response to the compressive load and thereby exerts a radially directed load on the shell 40 all about its inner circumference. The radial load on the shell loads the windings 42 and the filaments of the windings in tangentially directed tension or what may be termed "hoop tension". Since the fibrous material in the windings 42 preferably has a high strength and a high Young's modulus (i.e., it is substantially inextensible), it prevents the elastomer from expanding so that any deflection of the body of elastomer 12 must be through bulk compression. Since the bulk modulus of a body of elastomer is several hundred times greater than the compression modulus of the same body of elastomer when it is left free to bulge and deflect, the capacity of the mounting 10 to carry a compressive load is substantially increased in comparison to a similar mounting with an unconfined body of elastomer.
The mounting 10 has the ability to carry an extremely large compression load and still accommodate oscillatory rotational movements between a supported member (not shown) and a supporting structure (not shown). Rotational movements may be applied through the threaded shafts 20 and 30 and the rigid end plates 18 and 28, for example. Since the end plates 18 and 28 are bonded to opposite ends of the body of elastomer 12, the elastomer will be loaded in torsion. The shell 40, which is bonded to the circumferential surface 38 of the body of elastomer 12, will also be loaded in torsion. The flexible bond provided by the matrix material in the shell 40 permits relative parallel movement between adjacent filament portions, to include adjacent turns or windings 42 of the helically wound strand and adjacaent filaments in the strand. In operation, therefore, the shell 40 is free to flex in torsion with the body of elastomer 12 to accommodate torsional loads. The shell 40 may be characterized as anisotropic, being extremely stiff in response to hydrostatic-type radial loads, but being relatively soft in response to torsional loads.
Test specimens resembling the mounting 10 of FIG. 1 were constructed and tested for compression and torsional load capabilities. The bodies of elastomer in the test samples were fabricated of neoprene and varied from 0.38 inch in diameter by 0.50 inch high to 2 inches in diameter by 2 inches high. The cover assemblies were fabricated of steel. The exposed circumferential surfaces of the bodies of elastomer were painted with an adhesive and then covered with windings of fibrous material. The windings were formed by a continuous strand of graphite or Kevlar fibers coated with an elastomeric polyurethane coating. The radial thicknesses of the completed shells in the test samples varied from 0.16 inch to 2.06 inches. The samples exhibited maximum compression stiffnesses in the range of 140,000 to 500,000 pounds per inch and torsional stiffnesses in the range of 4 to 90 inch pounds per degree. The ultimate (failure)compressive loads on the samples varied from 7,400 pounds to 54,000 pounds with a vertical deflection (compression) of from about 0.1 inch to about 0.4 inch. The measured torsional stiffnesses were based on as much as 26° of torsional rotation. It is believed that the angle at which the strand of fibrous material is wound around the body of elastomer is significant and that the angle should preferably be maintained as close as possible to 0° (90° to the longitudinal axis of the mounting). Larger angles of wrap are believed to increase the torsional stiffness of the mounting. Increased torsional stiffness may or may not be desirable, depending upon the proposed use of the mounting.
The testing described above indicates that if axial loads are applied eccentric to the longitudinal axis of a mounting similar to the mounting 10, the mounting is likely to fail by buckling and extrusion of elastomer, rather than by failure of the filamentary structure of the shell 40. Buckling-type failure occrs at lower compressive loads than filamentary structure failure and thus reduces the usefulness of a mounting such as mounting 10. It is believed that the tendency to buckle can be overcome by incorporating in the shell 40 a plurality of filament portions oriented lengthwise of the mounting 10. As shown in FIG. 3, the longitudinally oriented or polar filament portions may be incorporated in longitudinal or polar filamentary strands 48 that overlie the windings 42. The strands 48 of FIG. 3 are not wound on the elastomeric body 12, but are applied in the form of a sheet of strands in a cured elastomeric matrix. The sheet of strands 48 and matrix material is secured to the windings 42 by any suitable adhesive. The longitudinally oriented filament portions may also be incorporated in the shell 40 by winding a single filamentary strand about the elastomeric body 12 and the cover plates 18 and 28, at least. One technique for applying such polar windings is described and illustrated in Krupp U.S. Pat. No. 3,112,234. At torsional deflections greater than about 5°-10°, polar windings will significantly and sharply increase the torsional stiffness of a mounting such as mounting 10.
FIG. 4 of the drawing illustrates another embodiment 50 of the invention. The mounting 50 is a modified form of a conventional mounting that accommodates high radial loads and oscillatory relative rotation between its radially inner and outer surfaces. The mounting 50 comprises a tubular inner metal member 52 surrounded by an annular body of elastomeric material 54. The main section 55 of the body of elastomeric material 54 is shorter than the tubular member 52, although a thin tapered section 56 or 57 of elastomeric material extends axially from each end of the main section 55 to the ends of the tubular member 52. Centered lengthwise of the body of elastomer 54 and the tubular member 52 is an annular sleeve 58 that encircles the body of elastomer and is bonded to the outer circumference 64 of the elastomer. Also surrounding the body of elastomer 54 but spaced axially from the sleeve 58 are a pair of annular and axially spaced apart end caps 60 and 62. Each of the end caps 60 and 62 engages and covers an end portion of the outer circumferential surface 64 of the main section 55 of the body of elastomer 54. The caps 60 and 62 also extend from the circumferential surface 64 over opposite ends of the main elastomeric section 55 and radially inwardly toward the tubular member 52. The radially innermost edges 66 of the end caps 60 and 62 are spaced radially from the tubular member 52 and from the tapered sections 56 and 57 of elastomeric material. The configuration of the end caps 60 and 62 permits limited relative radial movement between the caps and the tubular member 52.
Between the rigid sleeve 58 and each of the end caps 60 and 62 is an "exposed" portion of the outer circumferential surface 64 of the body of elastomer 54. Each "exposed" portion of the surface 64 is covered by a shell 68 or 70 that extends axially of the body of elastomer 54 between the sleeve 58 and the corresponding end cap 60 or 62. As in the shell 40 of FIGS. 1 and 2, each of the shells 68 and 70 comprises a multiplicity of substantially parallel and adjacent windings 72 embedded and encased in a flexible matrix material. The windings 72 are preferably formed of a continuous strand of fibrous or filamentous material coated with a flexible elastomeric coating. The fibrous material may be any one of several high strength, high Young's modulus materials, as discussed previously in connection with the mounting 10 of FIGS. 1 and 2. The coating or matrix material may similarly be any one of a number of flexible coatings. The shells 68 and 70 are bonded to the circumferential surface 64 of the body of elastomer 54 and to the adjacent surfaces of the sleeve 58 and the end caps 60 and 62. The bond to the surface 64 may be omitted, however.
The mounting 50 functions in generally the same manner as a conventional mounting that has a solid metal sleeve extending between and integral with the end caps 60 and 62. The mounting 50 will typically receive a shaft (not shown) through the central tubular member 52 and be pressed into a socket (not shown) that will engage the outer sleeve 58. The shaft will thus support the member defining the socket, through the mounting 50. One conventional installation would be as a shaft passing through an eye at one end of a leaf spring in a motor vehicle. In such installations, the mounting 50 is subjected to high compressive loads applied in a radial direction between the tubular member 52 and the outer sleeve 58. The shells 68 and 70 prevent the body of elastomer 54 from bulging radially in response to a radially directed compression load. The body of elastomer 54 can only bulge at its ends through the spaces between the end caps 60 and 62 and the tubular member 52. The mounting 50 will thus provide essentially the same radial compressive load carrying capabilities as a conventional mounting that incorporates a continuous outer sleeve.
The advantage of the mounting 50 of FIG. 4 over a conventional mounting of the same general type is that the body of elastomer 54 is less highly stressed in response to relative rotation between the tubular member 52 and the outer sleeve 58. In a conventional mounting, the radially inwardly depending flanges of the end caps 60 and 62 are part of and rotate with the outer sleeve 58 relative to the tubular member 52. As a result, the relative rotational movement between the sleeve and the tubular member is accommodated solely by torsional flexing of only that portion of the body of elastomer located between the radially innermost edges of the end caps and the inner tubular member. The relatively high strains imposed on the limited volume of elastomer being loaded in torsion effectively reduce the fatigue life of the elastomer. In the mounting 50, on the other hand, the end caps 60 and 62 can rotate relative to the sleeve 58 due to the torsional flexibility of the shells 68 and 70. The torsional load on the mounting is thus shared by the elastomeric material between the sleeve 58 and the end caps 60 and 62 and by the material between the end caps and the tubular inner member 52. The torsional load on the portion of the body of elastomer between the radially innermost edges 66 of the end caps 60 and 62 and the tubular member 52 is reduced and the fatique life of the mounting 50 is significantly improved as compared to a conventional mounting.
Although the foregoing discussion has dealt with shells comprising fibrous materials, such as carbon fibers, encapsulated with elastomeric materials, any other material or combination of materials that will provide the desired filamentary structure and flexible matrix may be utilized. For example, it is believed that the shell for a mounting such as described above could also be fabricated of an ultramolecular-oriented polymer. As is described in an article entitled "Molecular Composites - Can They Replace Metals?", appearing in the September 1975 issue of "Plastics Engineering" magazine, at pages 42-43, ultramolecular-oriented polymers comprise aligned and extended molecular chains surrounded by randomly oriented and unextended molecular chains. In a shell formed of such a polymer, the aligned molecular chains would provide the required filamentary structure, while the unaligned molecular chains would provide the matrix.
It will be understood that the embodiments described above are merely exemplary and that persons skilled in the art may make many variations and modifications without departing from the spirit and scope of the invention. All such modifications and variations are intended to be within the scope of the invention as defined in the appended claims. | A compression mounting comprises a body of elastomer and a pair of load-transmitting devices that engage and cover two opposed and spaced apart surfaces of the elastomeric body. The two load-transmitting devices are disposed and configured to expose a circumferential surface of the body of elastomer. At least a circumferential portion of the surfaces so exposed is completely covered and enclosed by a shell or housing. The shell includes a filamentary structure that provides a plurality of substantially parallel and juxtaposed filament portions oriented to circumscribe the surface of the elastomeric body. The filament portions are less extensible than the elastomer of the elastomeric body. A matrix material encases the filament portions and flexibly bonds adjacent filament portions to one another. The shell snugly fits the surface of the elastomeric body and is more resistant to circumferential expansion than the elastomeric body. The shell thus impedes, at least, the circumferential expansion of the elastomeric body in response to compression loads exerted on the body through the load-transmitting devices. As a result, the capacity of the mounting to support compressive loads is increased relative to a mounting incorporating unconfined elastomer. The matrix material permits adjacent filament portions to move in parallel planes relative to each other so that the shell and the mounting can deflect in response to torsional loads. | 5 |
This application is a non-provisional application for patent entitled to a filing date and claiming the benefit of earlier-filed Provisional Application for Patent No. 61/742,511, filed on Aug. 13, 2012 under 37 CFR 1.53 (c).
FIELD OF THE INVENTION
This invention relates to a system and a method for melting sulfur and, specifically, to an improved system and an improved method for melting solid sulfur and maintaining the resulting molten sulfur in liquid state. More specifically, the invention relates to safe sulfur melting methods and systems that may be fabricated, installed and operated at low capital costs, with high throughput rates at high operating efficiencies and low maintenance costs. Specific embodiments of the invention include modular and non-modular designs; and the invention may be installed and operated with low to high degrees of automation, allowing the user to tailor the final configuration to meet specific requirements.
BACKGROUND OF THE INVENTION
Conventional techniques for melting sulfur often involve mixing crushed, formed or otherwise solid sulfur with liquid sulfur in a tank that has been kept at temperatures above the melting point of sulfur and maintaining the contents of the tank at such temperatures by heating means. Crushed solid sulfur normally originates from solid sulfur lumps and from solid sulfur storage blocks, commonly known as “sulfur vats”; formed solid sulfur usually comes from special industrial operations designed to make specific forms of solid sulfur, such as slate sulfur and sulfur prills, sulfur pellets sulfur pastilles and other such types of granulated sulfur, which are intended for later melting and use as sulfur feed material in various industrial processes. At atmospheric temperatures sulfur is solid; and it remains solid as long as its temperature remains below approximately 240° F.; above this temperature sulfur becomes a fairly fluid liquid; and it remains a relatively low-viscosity fluid until its temperature reaches about 318° F. Above 318° F. sulfur turns very viscous and becomes difficult to pump.
A process for melting sulfur is described in U.S. Pat. No. 3,355,259, of Lipps et al, in which solid sulfur is fed into a tank and mixed with molten sulfur that has been maintained in liquid state at temperatures between 238° F. and 320° F. by the introduction of hot combustion product gases at certain points below the surface of the molten sulfur. This technique has had some commercial applications in the past, but its use is not cost efficient nowadays for various reasons, among them the additional costs required to monitor, process and control the hot combustion product gases in order to maintain the emissions within current environmental discharge requirements. In addition, the combustion product gases introduce contaminants into the liquid sulfur which translate into additional purification costs downstream and/or in the subsequent processing of the molten sulfur product. Certain other known processes for melting sulfur accomplish the melting by providing a melting vessel and introducing steam coils inside the vessel. These processes are able to produce molten sulfur but their overall efficiencies are limited by the limited heat transfer surface area and the size of the vessels that such arrangements entail.
It is an object of the present invention to provide a system and a method for melting sulfur that do not introduce into the molten sulfur any hot combustion gases or any other external sources of heating media, thus avoiding the cost efficiency disadvantages and the contamination problems associated with processes such as the Lipps et al process. It is also an object of this invention to provide a system and a method for the effective melting of crushed or formed solid sulfur that expedite and improve the removal of underflow solids from the tanks where most of the melting takes place and that do not require the introduction of steam coils inside the melting vessels. Another object of the invention is to provide safe sulfur melting methods and systems that may be fabricated, installed and operated at low capital costs, with high throughput rates at high operating efficiencies and low maintenance costs. A further object of the invention is to provide a practical and efficient system and a practical and efficient method for melting solid sulfur that lend themselves to modular fabrication and factory-assembly for easy and cost-effective shipping and on-site assembly. Yet another object of the invention is to provide a system and a method for the effective melting of solid sulfur that allow all of the molten sulfur to be safely contained during unplanned shutdown periods and where all of the vessels and equipment are located above ground, thereby eliminating or minimizing water intrusion, heat losses and other maintenance problems associated with systems and methods that locate vessels or equipment below ground. Still another object of the invention is to provide a system and a method for melting sulfur that allow the flexibility of processing both low and high volumes of solid sulfur feeds without sacrificing either safety or cost effectiveness. An additional object of the invention is to provide a system and a method for the effective melting of solid sulfur that can be industrially fabricated, installed and operated with minimal or no environmental consequences. These and other objects of the invention will become apparent from the descriptions that follow.
SUMMARY OF THE INVENTION
The system and the method for melting sulfur of this invention are described below with reference to their various system components and method steps. In its broadest embodiment the system of the invention comprises a combination of the following specific components: (a) a high-capacity melting unit; (b) means for pumping molten sulfur; and (c) a heat exchanger located outside the high-capacity melting unit and provided with means for heating pumped molten sulfur to a temperature of between about 275° F. and about 350° F. and returning it to the high-capacity melting unit. In one preferred embodiment the system of the invention comprises a specific arrangement of the following components: (a) a solid sulfur feed unit; (b) a high-capacity melting unit; (c) a compartmentalized pump tank assembly; and (d) a shell-and-tube heat exchanger located outside the high-capacity melting unit. In its broadest embodiment the method of the invention comprises a combination of the following specific steps: (a) receiving and melting solid sulfur in a high-capacity melting unit; (b) pumping the molten sulfur to a heat exchanger located outside the high-capacity melting unit; and (c) heating the pumped molten sulfur in said heat exchanger to a temperature of between about 275° F. and about 350° F. and returning it to the high-capacity melting unit. In one preferred embodiment the method of the invention comprises a specific arrangement of the following steps: (a) feeding solid sulfur to a high-capacity melting unit; (b) melting the fed solid sulfur in the high-capacity melting unit; (c) processing the molten sulfur through a compartmentalized pump tank assembly and pumping it to a shell-and-tube heat exchanger located outside the high-capacity melting unit; and (d) heating the processed and pumped molten sulfur in said shell-and-tube heat exchanger to a temperature of between about 275° F. and about 350° F. and returning it to the high-capacity melting unit.
The solid sulfur feed unit of the invention comprises a bulk solid sulfur feed hopper and a solid sulfur feed conveyor (sometimes referred to herein as the “melter feed conveyor”). The hopper is preferably provided with at least one vibrator on its outer surface. The solid sulfur feed unit may also include a lump breaker crusher, depending on the form of sulfur to be melted. The solid sulfur feed conveyor is preferably provided with a cover arrangement in order to prevent contaminants from being deposited on the sulfur feed and to prevent sulfur dust from being emitted from the sulfur handling system. The high-capacity melting unit comprises a vessel made of steel or similar strong material, having a sloped bottom and provided with at least one mixer, or agitator, and at least one overflow pipe conduit. The vessel is sometimes referred to herein as the “melter”; and it is preferably substantially round with a contoured, or molded, sloped bottom, although it may also have a rectangular shape. The melter is also equipped with external steam blisters, spaced around its outer surface, and used to more conveniently control the temperature of the walls or surfaces of the vessel whenever the ambient temperature fluctuates and to maintain the vessel at the desired temperatures during shutdowns. The term “high-capacity”, as used herein in conjunction with the melting unit, refers to the fact that such melting unit is capable of melting sulfur at a rate of between about 200 and 5,000 tons per day (“TPD”), or higher. During normal operations in accordance with the method of the invention sulfur flows out continuously through the high-capacity melting unit overflow pipe conduit and into the compartmentalized pump tank assembly, and also simultaneously and continuously along the contoured sloped bottom of the melter, through the transfer pipe conduit(s) and into the compartmentalized pump tank assembly. The compartmentalized pump tank assembly is connected to the high-capacity melting unit and comprises (i) a collection compartment that is equipped to receive and hold molten sulfur from the melting unit, (ii) a pumping compartment located downstream from the collection compartment and equipped with pumps that pump molten sulfur to a shell-and-tube heat exchanger and to a molten sulfur product tank or other molten sulfur destination, (iii) a combination of a weir and a fine-mesh screen, both of which are located between the collection compartment and the pumping compartment, with the fine-mesh screen placed above the weir in such a manner that they cause large-size non-meltables (solids other than sulfur) to settle and be collected in the collection compartment, from where they may be conveniently removed periodically by an operator or by some other means, and (iv) steam blisters or similar means for providing sufficient heat to the compartmentalized pump tank assembly to maintain the temperature of the molten sulfur inside the assembly at approximately 245° F. or higher. At least one pump is provided in the pumping compartment of the compartmentalized pump tank assembly to pump and circulate molten sulfur through the shell-and-tube heat exchanger(s), and at least one pump is provided for pumping molten sulfur out of the system. Under certain circumstances it may be possible to have one pump perform both functions, that is, pump and circulate molten sulfur through the heat exchanger(s) and pump sulfur out of the system. The collection compartment allows the settling of the non-meltables in an area from where they may be conveniently removed periodically, as needed, for example by a mechanical excavator, thereby avoiding the significant delays encountered with conventional melting systems due to having to shut down the system for several days in order to allow time to cool and conduct a “turnaround”, i.e., to clean out the melter and pumping equipment, etc.
Sulfur is pumped out of the pumping compartment located downstream from the collection compartment and sent to the prescribed shell-and-tube heat exchanger(s). The prescribed shell-and-tube heat exchanger(s) is (at least one) shell-and-tube heat exchanger designed so that some of the molten sulfur that accumulates in the compartmentalized pump tank assembly may be pumped into and flow inside the heat exchanger tubes while steam is made to flow inside the heat exchanger shell and allowed to condense on the outside of the tubes. Depending on the characteristics of the particular sulfur to be melted, other embodiments of the invention may also make use of different types of heat exchangers, such as plate-and-frame heat exchangers and others. In the shell-and-tube heat exchanger, or exchangers, enough steam is provided to heat the pumped molten sulfur in the heat exchanger tubes to a temperature of between about 275° F. and about 350° F. The heated molten sulfur is then made to exit the tubes of the shell-and-tube heat exchanger and flow into the high-capacity melting unit, where it releases the bulk of the heat (added in the shell-and-tube heat exchangers) to melt the incoming solid sulfur and maintain it in molten state. This feature of the melting system and method of the invention means that virtually all of the system's heating means required to melt the sulfur and maintain its temperature at between about 250° F. and about 300° F. are located outside the melting unit, and not inside the melting unit as is the case in most conventional sulfur melting systems and methods; in other words, the bulk of the heat transfer required by the unit operation takes place outside the melter and melting unit. A competitive advantage of the invention is that the system may be shop-fabricated as a plurality of modules, for example as a package of a bulk solid sulfur feed hopper module, a high-capacity melting unit module, a compartmentalized pump tank assembly module and a heat exchanger module, plus a conveyor assembly module.
In one preferred embodiment of the invention a constantly flowing underflow arrangement is installed on the bottom of the melter's contoured, cone shaped bottom. This underflow arrangement provides continuous removal of non-meltable solids from the bottom of the melter and prevents their build up in the vessel, thereby greatly reducing the potential for significant delays encountered with conventional melting systems due to having to shut down the system for several days in order to allow time to cool and remove the built up solids from the bottom of the melting tank. By providing this underflow, the propensity for abrasion and other damage to the melter from constant movement of these particles is greatly reduced. A grating screen may also be installed as part of the arrangement to prevent very large particles from entering and plugging the underflow.
In another embodiment of the invention a large, non-meltable trash collection sump is added to the bottom of the melter. The collection sump provides a location outside of the melter's vigorous agitation section where large non-meltables may collect. By providing this sump, the propensity for abrasion and other damage to the melter from constant movement of these larger particles is greatly reduced. A cleanout “man way” or “hand way” is normally provided to allow easy removal of these solids. A grating screen may also be installed in the sump when an underflow is provided as discussed above.
In an alternative embodiment of the invention the system and the method disclosed herein are applied to and used in conjunction with a conventional sulfur melting unit of the type that incorporates and employs internal steam coils, or other heating means, located inside said conventional sulfur melting unit, to supplement and improve the efficiency of the sulfur melting operation. This may be done as a new design that combines the external heating concept of the present invention with the internal heating concept of conventional sulfur melting units; or it may be done by incorporating the external heating concept of the present invention to an already existing system that uses conventional internal steam coils, or other heating means, located inside the existing sulfur melting unit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram depicting the key components of the system of the invention arranged in the manner specified by one of the preferred embodiments of the system of the invention.
FIG. 2 is a schematic diagram depicting the key features of the melter component (high-capacity melting unit) of a preferred embodiment of the system of the invention.
FIG. 3 is a rendering of a modular sulfur melting system designed after one of the preferred embodiments of the invention and showing the key modular components of the system of the invention and the key unit operations of the method of the invention.
DETAILED DESCRIPTION OF THE INVENTION
By way of illustration, the sulfur melting system and the sulfur melting method of the invention will be described below with reference to one specific embodiment of the invention, specifically with reference to portions of a system that the owners of the invention have designed for a specific sulfur melting operation. It will be understood that a number of different embodiments are possible which may be adapted to suit the application of the invention to the particular circumstances of other sulfur melting operations.
The specific system design of this particular embodiment is referred to herein as the “High-Capacity Sulfur Melter” or, simply, the “HiCap Sulfur Melter”. The HiCap Sulfur Melter is believed to incorporate the best melting technology in the industry, offering the lowest capital costs, the lowest operating costs and the highest operating efficiencies. In addition, it provides the lowest cost-per-ton of molten sulfur produced while operating within one of the safest methods of remelting sulfur. (Since sulfur is often melted, allowed to solidify and then melted again in many industrial operations, it is not uncommon in industry to use the term “remelting” and “remelted” interchangeably with “melting” and “melted”. No difference with respect to the physical process or unit operation of melting sulfur is intended herein between “melting” and “remelting”, or between “melted” and “remelted”.) The modular design of the HiCap Melters also lends itself to easy relocation and lower installation cost than melters used by other technologies.
The specific HiCap Sulfur Melter system design of this particular embodiment has a rated capacity of 100 tons of sulfur per hour (“TPH”), i.e., 2,400 liquid tons of sulfur per day (“TPD”), and offers the following features and competitive advantages: (a) higher capacity allows much greater flexibility and lower cost for operations; (b) melting can be accomplished with reduced manning (reduced hours); and (c) melting rates may be increased or decreased as market conditions dictate and still accomplish the goal of timely melting the desired sulfur quantities. The specific HiCap Sulfur Melter system incorporates key design functionality, allowing lower maintenance costs, downtime and a high degree of automation. In addition, the modular design allows for easy relocation of the unit from block to block and minimizes installation manpower, cost and risk.
The HiCap Sulfur Melter system comprises a combination of the following components: (a) a solid sulfur feed unit; (b) a high-capacity melting unit; (c) a compartmentalized pump tank assembly; and (d) a shell-and-tube heat exchanger located outside the high-capacity melting unit. These components are shown and identified on FIG. 1 . Referring to FIG. 1 , bulk solid sulfur 1 is fed at ambient temperature to solid sulfur feed unit 2 through bulk solid sulfur feed hopper 3 at a rate of approximately 100 TPH. Bulk solid sulfur feed hopper 3 is equipped with vibrator 4 , attached to its outer surface, and with lump breaker crusher 5 , attached to and below its cone shaped bottom. A grizzly 6 sits on top of hopper 3 and allows −10″ bulk sulfur to pass through and into vibrating hopper 3 and lump breaker crusher 5 , where its size is reduced to −2″. As used herein the designations −10″ and −2″ refer to those solid sulfur particles that have an average size of less than about 10 inches in diameter and less than about 2 inches in diameter, respectively. The −2″ bulk sulfur exits lump breaker crusher 5 and moves on to melter feed conveyor 7 , operably connected to the discharge end of lump breaker crusher 5 . Melter feed conveyor 7 is a variable speed belt conveyor comprising conveyor belt 8 , which is operated by rollers 9 , driven by conveyor motor 10 . It is convenient to maintain a stockpile of crushed vat sulfur or crushed lumps of sulfur nearby the solid sulfur feed hopper when melting. A front-end loader can be used to charge solid sulfur feed hopper 3 from the solid sulfur stockpile.
The −2″ bulk sulfur 11 from melter feed conveyor 7 is fed to high-capacity melting unit 13 through conveyor discharge chute 12 . The rate of the feed (from hopper to melter) of −2″ bulk sulfur 11 into to high-capacity melting unit 13 is controlled by controlling the speed of conveyor belt 8 . The rate is normally determined by the heat that is available in the melter to melt the sulfur. Melter feed conveyor 7 is provided with appropriate instrumentation to help ensure its safe operation.
Bulk solid sulfur 11 from conveyor discharge chute 12 enters the high-capacity melting unit vessel (also referred to as the “melter”) 14 and encounters hot liquid sulfur 44 , which is continuously fed to melter 14 from shell-and-tube heat exchangers 33 (as explained below) thereby forming a mixture of the two sulfurs (ambient-temperature bulk solid sulfur 11 and hot liquid sulfur 44 ). Melter 14 has an inner surface, an outer surface and a sloped bottom. The melter is preferably round or substantially round, with a contoured cone-shape bottom, and is preferably made of steel; however, it may have a rectangular shape or other shapes, and it may also be made of metal, such as stainless steel or aluminum, as well as of other strong material properly selected for operating at the previously stated temperatures. Melter 14 is equipped with at least one mixer, or agitator, 15 , driven by agitator motor 16 . Melter agitator 15 may create a vortex that immediately pulls the −2″ bulk solid sulfur 11 beneath the surface of the liquid sulfur, wetting all solid surfaces and thereby expediting the melting process. Simultaneously, the vigorous agitation immediately incorporates into the mixture hot liquid sulfur 44 (which is continuously fed to melter 14 from shell-and-tube heat exchangers 33 ), thereby providing rapid melting. One agitator with a single blade will suffice in many cases, but it is also feasible to use one agitator with multiple blades, as well as multiple agitators with single or with multiple blades. The temperature in melter 14 , i.e., the temperature of the inner surface and the outer surface of melter 14 , is maintained at approximately 245° F. or higher (and preferably between about 250° F. and 260° F., or higher) by the addition of liquid sulfur 44 heated in steam heated shell-and-tube heat exchanger(s) 33 to approximately between about 275° F. and 350° F. (and preferably between about 280° F. and 290° F.). The rate at which bulk sulfur 11 should be added to melter 14 is determined by the heat available for melting sulfur in melter 14 . The speed of conveyor belt 8 may be controlled by monitoring the temperature of the sulfur in melter 14 and maintaining the conveyor belt speed such that the temperature of the sulfur in melter 14 is kept at a constant pre-established level. In the HiCap Sulfur Melter system depicted in FIG. 1 bulk sulfur 11 enters melter 14 at a rate of approximately 200 TPH; while hot liquid sulfur 44 from shell-and-tube heat exchanger 33 enters melter 14 at a rate of between about 400 and 800 TPH.
Steam blisters 17 are provided on the outer surface of melter 14 to keep the outside surface and the inside surface of the melter hot enough (above approximately 245° F.) in order to conveniently prevent the sulfur in and around the melter from solidifying and clogging the vessels, pumps, conduits and other equipment during scheduled and unscheduled shutdowns (e.g., for cleaning, repairs, and/or regular maintenance) or for any other reason, including periodic fluctuations of the ambient temperature. The steam blisters do not contribute any significant amount of heat to the actual melting of the sulfur inside the melter, since all (or virtually all) of the heat used for melting the sulfur in the melter is provided by the molten liquid sulfur 44 that is generated in the shell-and-tube heat exchangers (as mentioned above and explained below). The steam blisters are preferably circular or semi-circular conduits equipped to receive 50 psig-steam from a steam source (not shown) and release condensate after giving off the required amount of heat. The blisters are preferably placed around and surrounding the melter vessel as shown on FIG. 1 and FIG. 2 . They also may have rectangular conduit shapes and may be placed around the melter in different configurations. In addition to or instead of the steam blisters other means may be used for providing sufficient heat to the melter to keep its outside surface and its inside surface above approximately 245° F. during scheduled and unscheduled shutdowns. Such other means include steam heating tracing, electrical heating tracing and heating devices that use hot oil or pressurized hot water, as well as other such heating means as may be available and practicable.
Melter overflow molten sulfur 18 overflows and exits melter 14 by way of overflow pipe conduit 19 at approximately 255° F. and is directed to compartmentalized pump tank assembly 20 , where it first enters into collection compartment 21 . Likewise, limited rates of melter underflow molten sulfur 22 underflow and exit conical melter bottom 23 and are also directed to collection compartment 21 of compartmentalized pump tank assembly 20 . By directing underflow molten sulfur 22 into collection compartment 21 in this fashion the melting system is able to collect and eventually remove non-meltables 24 and prevent them from settling in the bottom of the melter. Non-meltable solids that are too large to pass through the underflow piping with underflow molten sulfur 22 are collected in trash sump 45 . These features, that is, the trash sump and directing underflow molten sulfur 22 into collection compartment 21 , extend the time between melter clean-outs, thereby improving the operability and the efficiency of the melting system and the melting method. Non-meltables include pebbles, rocks, nuts, bolts, bottles, pieces of wood, debris, plastic bags, plastic containers and the like, which tend to inadvertently enter the solid sulfur storage stockpile from time to time. In the HiCap Sulfur Melter system depicted in FIG. 1 melter overflow molten sulfur 18 enters collection compartment 21 at a rate of between about 500 and 1,000 TPH; while melter underflow molten sulfur 22 enters collection compartment 21 at a rate of between about 30 and 60 TPH.
Compartmentalized pump tank assembly 20 comprises a single tank that is divided into at least two compartments. The first compartment (collection compartment 21 ) is equipped to receive and hold molten sulfur from high-capacity melting unit 13 , and it is preferably subdivided into multiple sub-sections by means of one or more internal baffles 25 . The baffles provide a circuitous route for the molten sulfur flowing within compartmentalized pump tank assembly 20 , and thereby prevent or minimize short circuiting of the circulating molten sulfur to ensure adequate retention time in compartmentalized pump tank assembly 20 . Collection compartment 21 is also equipped with weir 26 and fine-mesh screen 27 , so structured and located that large-size non-meltables may be collected and caused to settle in collection compartment 21 , from where they may be conveniently removed periodically, as needed, by a mechanical excavator, or by some other practicable means, thereby avoiding having to shut down the system for several days in order to allow time to cool and conduct a “turnaround” (clean up the melter and pumping equipment, etc.). Weir 26 is made of steel, and typically would extend approximately 12 inches above the floor of compartmentalized pump tank assembly 20 , extending the entire width of the assembly, and welded or otherwise connected to both (opposite) sides of the assembly. Weir 26 may also be made of aluminum, stainless steel, plastic, synthetic or other strong material. Fine-mesh screen 27 is located contiguous with and above weir 26 , extending from the top of the weir to approximately 12 inches above the normal operating level of the molten sulfur in compartmentalized pump tank assembly 20 , and also extending the entire width of the assembly. Fine-mesh screen 27 is made of steel and has ¼ inch mesh openings. The screen may also be made of aluminum, stainless steel, plastic, synthetic or other strong material, and its mesh openings are typically anywhere between about 1/16 and ½ inch. For convenience in the maintenance and up-keep of the sulfur melting system fine-mesh screen 27 may be fabricated and installed as an easily removable and/or replaceable part of the system, and preferably would be designed to slide in and out of compartmentalized pump tank assembly 20 via a slotted guide. The design should preferably allow removal and replacement of the screen within the compartmentalized pump tank assembly in “hot” condition, i.e., while molten sulfur at 245° F., or higher, flows through it.
Molten sulfur exiting melter 14 as melter overflow molten sulfur 18 and melter underflow molten sulfur 22 enters downstream collection compartment 21 and passes through fine-mesh screen 27 into pumping compartment 28 . Pumping compartment 28 is provided with pumps and pumping equipment that pump molten sulfur from compartmentalized pump tank assembly 20 to the shell-and-tube heat exchangers and to a molten sulfur product tank or other suitable destination. Thus, heat exchanger sulfur pump 29 , operated by heat exchanger sulfur pump motor 30 , pumps molten sulfur 31 into the tube side inlet head 32 of shell-and-tube heat exchanger 33 ; while product storage tank sulfur pump 34 , operated by product storage tank sulfur pump motor 35 , pumps molten sulfur 36 into sulfur product storage tank 39 . One or more strainers 37 are provided between compartmentalized pump tank assembly 20 and sulfur product storage tank 39 in order to remove certain entrained solid impurities that may still be present in the molten sulfur at this point in the system. Two duplex inline strainers are preferred for removing the entrained particulates. Clean molten sulfur product 38 , at a rate of approximately 200 TPH, is then stored in sulfur product storage tank 39 , from where it may be stored, pumped or otherwise delivered off battery limits to the customer's molten sulfur storage facilities. Sulfur product storage tank 39 is provided with steam blisters or other heating means (not shown) to aid in keeping it at an acceptable temperature. Depending on customer needs and the specific logistics of the operations, it may also be practicable to allow the sulfur in pumping compartment 28 to overflow pumping compartment 28 into another vessel or container rather than pumping it to sulfur product storage tank 39 .
The bulk of the non-meltables that were caused to be deposited in collection compartment 21 can be removed from the bottom of compartmentalized pump tank assembly 20 in “hot” condition. When the volume of non-meltables builds up against weir 26 feed conveyor 7 is stopped and new bulk solid sulfur feed to the melting system is discontinued; a large hatch (not shown) on top of compartmentalized pump tank assembly 20 is then opened, allowing access to the interior of the assembly, where non-meltables 24 are subsequently easily removed by a few excavator scoops. Feed conveyor 7 is subsequently restarted and the melting process continued. This particular step (opening compartmentalized pump tank assembly 20 and scooping out accumulated non-meltables 24 ) only takes a couple of hours and is much faster and efficient than the steps taken in conventional melting methods, where tank cleanouts require drainage, cooling, clean out and reheating before resuming service, normally a five-to-seven day turnaround. Compartmentalized pump tank assembly 20 is provided with an automatic level control (not shown) such that all of the newly melted sulfur may be continually pumped to sulfur product storage tank 39 and, eventually, to customers' liquid storage facilities. Compartmentalized pump tank assembly 20 is also provided with steam blisters 40 , or similar heating means, to aid in keeping it at an acceptable temperature (at least 245° F.).
As explained above, heat exchanger sulfur pump 29 , operated by heat exchanger sulfur pump motor 30 , pumps molten sulfur 31 , at about 255° F., into the tube side inlet head 32 of shell-and-tube heat exchanger 33 , where the molten sulfur is heated to between about 280° F. and 300° F. and circulated to high-capacity melting unit 13 . More than one pump may be used to pump molten sulfur 31 . The pump, or pumps, should provide sufficient pressure to pump the molten sulfur through the heat exchanger tubes and allow it to reach melter 14 after being heated to the desired temperature (between about 280° F. and 300° F.). In a preferred embodiment two shell-and-tube heat exchangers, connected in parallel, are used to perform the function of shell-and-tube heat exchanger 33 . Steam 41 is injected into shell section 42 of shell-and-tube heat exchanger 33 , where it give off heat before condensing and exiting shell-and-tube heat exchanger 33 as condensate 43 . Maintaining steam pressure on the shell side of the exchanger at about 70 psig (316° F.) maximizes heat transfer without tube fouling. Flow rates through shell-and-tube heat exchanger 33 are designed to maintain satisfactory heat transfer coefficients and prevent tube fouling. In this fashion virtually the entire source of the heat supplied to high-capacity melting unit 13 for melting sulfur is provided by high-efficiency shell-and-tube heat exchanger 33 . The thus heated molten sulfur exits heat exchanger 33 as hot liquid sulfur 44 , at between about 280° F. and 300° F., and is then circulated to melter 14 , where it transfers its heat to incoming bulk solid sulfur 11 .
A molten sulfur product destination may be a sulfur product tank, similar to sulfur product storage tank 39 , or it may be a sulfur processing system such as a sulfur filtration unit or any other system commonly employed to further process molten sulfur for a number of industrial uses, such as for feed to sulfuric acid manufacturing plants and the like. In order to achieve high efficiencies in the operation of the melting system and method the degree of turbulence provided inside the shell-and-tube heat exchangers should be enough to cause good heat transfer, but not so much as to cause erosion (excessive wear) of the tubes; also the amount, temperature and pressure of the steam used and the flow rates of the molten sulfur streams should be monitored and controlled in order to maintain the prescribed temperature ranges in the melter and in the shell-and-tube heat exchangers.
A preferred embodiment of the high-capacity melting unit of the invention is shown in FIG. 2 , where melter 51 , equipped to receive solid sulfur through sulfur feed inlet pipe conduit 52 and molten sulfur through molten sulfur inlet pipe conduit 53 , is depicted with one single agitator 54 , having a single blade 55 and driven by agitator motor 56 . Melter 51 is also provided with sulfur overflow pipe conduit 57 , baffles 58 and steam blisters 59 . The steam blisters are welded to the outer surface of melter 51 , including the outer surface of its conical sloped bottom 63 . Agitator 54 is used to provide vigorous agitation of the mixture of solid sulfur coming into the melter through sulfur feed inlet pipe conduit 52 and hot molten sulfur coming in through molten sulfur inlet pipe conduit 53 . The vigorous agitation of the mixture immediately pulls the incoming solid sulfur beneath the surface of the liquid sulfur, wetting its solid surface and also quickly incorporating into the mixture the incoming hot molten sulfur, thereby causing the rapid melting of the incoming solid sulfur. Baffles 58 prevent the mixture from just spinning inside the melter; and the impact of the moving molten sulfur hitting the baffles causes additional turbulence and mixing within the melting unit. Baffles 58 also cause the molten sulfur to sweep across melter conical bottom 63 , thereby reducing the potential for settling and buildup of non-meltables on the bottom. A first portion of the molten sulfur exits melter 51 through sulfur overflow pipe conduit 57 and is directed to the compartmentalized pump tank assembly of the system. A second portion of the molten sulfur passes through trash sump 61 , exits the melter through sulfur underflow pipe conduit 60 and is also directed to the compartmentalized pump tank assembly of the system. Non-meltable solids that are too large to pass through sulfur underflow pipe conduit 60 are collected in the upper portion 66 of trash sump 61 from where they may be periodically removed through trash sump access man way 62 . Removal of these larger solid non-meltables may be conveniently done by opening the blind closing flange of access man way 62 and disposing of them in appropriate fashion. Non-meltables include pebbles, rocks, nuts, bolts, bottles, wrenches, bricks, pieces of wood, debris, plastic bags, plastic containers and the like. Grating screen 64 separates upper portion 66 of trash sump 61 from the lower portion 65 of the sump. Non-meltables generally gravitate towards conical slopped bottom 63 of melter 51 and find their way into trash sump 61 . Sulfur in trash sump 61 is generally outside of the vigorous agitation that takes place in melter 51 which allows both the larger and the smaller non-meltables to accumulate there. As previously mentioned, the larger non-meltables accumulate on the upper side of grating screen 64 in the upper portion 66 of trash sump 61 , while the smaller non-meltables travel through grating screen 64 and into lower portion 65 of trash sump 61 . The smaller non-meltables then travel with the aforementioned second portion of the molten sulfur which is passing through trash sump 61 and, together, they exit melter 51 through sulfur underflow pipe conduit 60 , and are further directed to the compartmentalized pump tank assembly of the system, as shown on FIG. 1 , where they are made to settle out and from where they are periodically removed by an excavator bucket or similar means.
FIG. 3 depicts the sulfur melting system of the invention in modular form, showing the key shop-fabricated modular components of the system and the key unit operations of the method of the invention. Referring to FIG. 3 , melter 71 is equipped with solid sulfur inlet 72 , adapted to receive solid sulfur from a conveyor discharge chute of a solid sulfur feed unit (not shown). Melter 71 is also equipped with steam blisters 73 , spaced around its outer surface, and with sulfur overflow pipe conduit 74 . Molten sulfur from melter 71 is made to flow through sulfur overflow pipe conduit 74 into collection compartment 75 of compartmentalized pump tank assembly 76 , which is equipped with steam blisters 77 to aid in providing sufficient heat to keep the molten sulfur that flows through the assembly at the desired temperature of at least 245° F., as already explained. An excavator 78 is shown scooping out non-meltables from the bottom of compartmentalized pump tank assembly 76 . Hatch 85 , on top of compartmentalized pump tank assembly 76 , provides access to the interior of the assembly, where the non-meltables are easily removed by a few excavator scoops. Heat exchanger pump motors 79 operate the heat exchanger pumps that pump molten sulfur out of compartmentalized pump tank assembly 76 through sulfur pipe conduits 80 into shell-and-tube heat exchangers 81 , arranged in parallel fashion. Product sulfur pump motor 83 operates the product sulfur transfer pump that pumps molten sulfur out of compartmentalized pump tank assembly 76 through sulfur pipe conduit 84 into a sulfur product storage tank (not shown). The heated molten sulfur exits the tubes of shell-and-tube heat exchangers 81 through sulfur pipe conduits 82 and flows into the upper portion of melter 71 , where it releases the bulk of the heat added in the heat exchangers, thereby melting the incoming solid sulfur fed to the melter through solid sulfur inlet 72 and maintaining it in molten state, thus completing the unit operation cycle.
Routine maintenance of the sulfur melting system by the operators may consist of general house-keeping, the switching and cleaning of operating strainers as their elements begin to clog and normal maintenance of lubricants, tightening valve packing, repair of minor steam/water drips, etc. Scheduled turnarounds may include pump, agitator and general conveyor servicing and routine motor control center maintenance, which can be done on a periodic basis. If convenient, the compartmentalized pump tank assembly may receive a complete cleanout during turnarounds.
While the present invention has been described herein in terms of particular embodiments and applications, in both summarized and detailed forms, it is not intended that any of these descriptions in any way should limit its scope to any such embodiments and applications; and it will be understood that substitutions, changes and variations in the described embodiments, applications and details of the method and the formulations disclosed herein can be made by those skilled in the art without departing from the spirit of this invention.
Where the article “a” (or “an”) is used in the following claims, it is intended to mean “at least one” unless clearly indicated otherwise. | A system and a method are provided for melting solid sulfur and maintaining the resulting molten sulfur in liquid state. The system and the method may be fabricated, installed and operated at low capital costs, with high throughput rates at high operating efficiencies and low maintenance costs. Specific embodiments of the invention include modular and non-modular designs, which may be installed and operated with low to high degrees of automation, allowing the user to tailor the final configuration to meet specific requirements. The system of the invention comprises a specific configuration of a prescribed solid sulfur feed unit, a prescribed high-capacity melting unit, a compartmentalized pump tank assembly, and a heat exchanger located outside the high-capacity melting unit. The method provided follows the configuration of the system. | 5 |
CROSS REFERENCE DATA
[0001] The present patent application is a divisional of co-pending U.S. patent application Ser. No. 12/756,444, incorporated herein by reference, which was a Continuation-In-Part of U.S. patent application Ser. No. 11/813,471, which was an Entry into U.S. National Phase of PCT application No. PCT/CA2006/000907 filed on Jun. 2, 2006 and also claimed conventional priority of U.S. provisional patent application No. 60/886,336 filed Jun. 8, 2005.
FIELD OF THE INVENTION
[0002] The present invention relates to cleaning devices, and more particularly to a portable dusting tool for cleaning delicate surfaces.
BACKGROUND OF THE INVENTION
[0003] Digital cameras comprise an electronic sensor, such as a charge-coupled device (CCD) sensor or Complementary Metal Oxide Semiconductor (CMOS) sensor, lodged in a recessed sensor chamber of the camera, and onto which is projected the image of what is seen through the lens of the camera. This sensor can acquire the image projected thereon and convert it into electronic data, which is thereafter forwarded to data processing means provided on the digital camera. The data processing means then converts this electronic data into an image file of known format, such as in JPEG, TIFF or RAW formats, stored thereafter on the memory card of the camera. Of course, this sensor must remain as clean as possible, since impurities deposited thereon can undesirably alter the final image acquired by the camera.
[0004] It is inevitable that during normal use of a digital camera, its sensor will become exposed to the atmosphere and its airborne impurities, such as minute airborne dust particles. More particularly, on professional digital cameras having interchangeable lenses such as digital single-lens reflex (DSLR) cameras, the sensor exposed lens surface inevitably becomes contaminated by the atmosphere and its impurities whenever the lens is removed from the body of the camera, for example when switching lenses.
[0005] To clean the sensor of their digital cameras, and more particularly to remove dust particles from its surface, digital camera owners have come up with a number of cleaning methods.
[0006] A common cleaning technique used by digital camera owners is to blow air from a canned air duster directly about the surface of the sensor. This technique, in addition to blowing away the dust on the sensor, has the adverse effect of dispersing and not removing dust particles.
[0007] An alternate technique is to blow canned air into the bristles of a brush and then sweeping the surface of the sensor with the brush. Pressurized air is blown on the bristles for two purposes: (1) for blowing away all impurities that may be present between the bristles of the brush, and (2) for electrostatically charging the bristles of the brush, and thus enhancing the brush's capacity to pick up dust particles present on the camera sensor.
[0008] However, this latter technique also has its drawbacks. Indeed, liquid sometimes squirts out of canned air dusters when air is blown on the bristles, and liquid can thereafter be undesirably smeared on the surface of the sensor when the brush is swept thereacross. Another disadvantage of using canned air dusters is that they are pressurized containers and it is prohibited to bring them aboard aircrafts, which can be inconvenient for travelling photographers for example. Furthermore, pressurized air duster cans are not reusable, and after such a duster has been emptied, it is disposed of and a new one must be purchased.
SUMMARY OF THE INVENTION
[0009] The invention relates to a non-scrubbing dusting tool for cleaning the exposed surface of a digital camera sensor lens in a recessed digital camera sensor chamber, said dusting tool comprising : a duster member defining an elongated shank having opposite one and another end, a tuft of bristles having electrostatic charge built up therein, and first connector means directly coupling said tuft of bristles to said shank one end; a handle; and second connector means directly coupling said handle to said shank another end; wherein each of said bristles define a corresponding leading edge tip opposite said shank, said leading edge tips for operative engagement with the sensor lens; wherein said duster member is sized to adjustably fit inside the camera sensor chamber in such a fashion that said bristles leading edge tips will be able to reach all of the exposed surface of the camera sensor lens while avoiding contaminating contact with the camera sensor chamber; and wherein in an operative sensor lens cleaning condition of said dusting tool, said duster member remains motionless relative to said handle while said dusting tool bristles leading edge tips are manually swept over the camera sensor lens to be cleaned.
[0010] Preferably, there is further included a selectively activated duster actuator, fixedly mounted to said handle and rotatably mounted to said shank; said actuator operating only when said dusting tool is not cleaning the sensor lens; wherein once said electrostatic charge of said tuft of bristles has been depleted, said electrostatic charge thereof is recharged while concurrently removing dust collected by said bristles by bringing said duster tool to an inoperative sensor lens cleaning condition away from the camera sensor chamber and with said actuator being powered to power rotate said shank, wherein said bristles will fan out radially under centrifugal forces.
[0011] Said actuator could then be lodged into a cavity made into said handle. Said first connector means could also consist of a tubular element, integral to said shank one end and defining a flattened mouth portion opposite said shank one end, said tuft of bristles defining an inner end portion frictionally taken in sandwich within said tubular element flattened mouth portion.
[0012] Preferably, said tubular element flattened mouth portion further defines a pair of opposite notches, said notches engaged by registering bristles from said tuft of bristles, wherein said tuft of bristles form a V-shape in said operative lens cleaning condition of said dusting tool, said V-shape providing enhanced lens cleaning capabilities The bristles could be made from polyimide, and preferably having a thickness with the range of 40 to 60 micrometers, and preferably being tapered at their leading edge tip portion. The electrostatic charge build up of said bristles could enable attraction of macroscopic particles up to 14 millimeters in total length, and/or attraction of macroscopic particles down to 1 micrometer in total length.
[0013] The invention also relates to a method of use of a dusting tool for cleaning the exposed surface of a camera sensor lens in a recessed digital camera sensor chamber while avoiding contaminating contact with the side walls of the camera sensor chamber, the method comprising the following steps: a) providing a non-scrubbing duster member defining an elongated shank having opposite one and another ends, a tuft of bristles having electrostatic charge built up therein and first connector means directly coupling said tuft of bristles to said shank one end; a handle; and second connector means directly coupling said handle to said shank another end, with each of said bristles defining a corresponding leading edge tip opposite said shank; b) engaging said duster member inside the camera sensor chamber;
[0014] c) operatively engaging said bristles leading edge tips onto the exposed surface of the camera sensor lens; d) manually sweeping said dusting tool bristles leading edge tips over the full exposed surface of the camera sensor lens including the peripheral edge portion thereof but excluding contaminating contact with the side walls of the camera sensor chamber, while said duster member remains motionless relative to said handle.
[0015] Preferably, in step (a), the electrostatic charge build-up is imparted to said bristles by applying a chemical to said bristles. Alternately, in step (a), the electrostatic charge build-up if said bristles is imparted to said bristles by applying an ionization treatment to said bristles. There could also be further included the steps of: providing a selectively activated duster actuator, fixedly mounted to said handle and rotatably mounted to said shank; depleting said electrostatic charge of said tuft of bristles following said sweeping action of said dusting tool bristles leading edge tips; bringing said duster tool to an inoperative sensor lens cleaning condition and away from the camera sensor chamber; and powering said actuator wherein said shank is power rotated and said bristles are brought to fan out radially under centrifugal forces leading to recharging of said electrostatic charge of said bristles while concurrently removing dust collected by said bristles during said manual sweeping step.
[0016] Preferably, in step (c), said operative engagement of the bristles leading edge tips includes the step of non-contacting sweeping action over the exposed surface of camera sensor lens in closely spaced fashion relative thereto. Alternately, in step (c), said operative engagement of the bristles leading edge tips includes the step of direct contacting sweeping action against the exposed surface of camera sensor lens.
[0017] The invention also relates to the combination of a digital camera having a recessed camera sensor chamber and a sensor lens at a flooring section of said camera sensor chamber, said sensor lens having an exposed surface opening into said camera sensor chamber, and a non-scrubbing dusting tool for cleaning said exposed surface of said camera sensor lens, said dusting tool comprising : a duster member defining an elongated shank having opposite one and another end, a tuft of bristles having electrostatic charge built up therein and first connector means directly coupling said tuft of bristles to said shank one end; a handle; and second connector means directly coupling said handle to said shank another end; wherein each of said bristles define a corresponding leading edge tip opposite said shank, said leading edge tips adapted to operatively engage with said sensor lens; wherein said duster member is sized to adjustably fit inside the camera sensor chamber in such a fashion that said bristles leading edge tips will be able to reach all of the exposed surface of the camera sensor lens while avoiding contaminating contact with the camera sensor chamber; and
[0018] wherein in an operative sensor lens cleaning condition of said dusting tool, said duster member remains motionless relative to said handle while dusting tool bristles leading edge tips are manually swept over the camera sensor lens to be cleaned.
[0019] Preferably, there is further included an elongated protective cap, releasably mounting over said duster member in friction fit fashion against said second connector means when said dusting tool is not in use.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In the annexed drawings:
[0021] FIG. 1 is a perspective view of a dusting tool according to a first embodiment of the present invention;
[0022] FIG. 2 is a front elevation of the dusting tool of FIG. 1 with the handle member and the brush connector cut away, and showing how the bristles of the brush fan out and are rid of dust when the user activates the dusting tool shank rotating motor;
[0023] FIG. 3 is an exploded front perspective view of the embodiment of dusting tool of FIG. 1 , the dusting tool having a brush and corresponding brush connector;
[0024] FIG. 4 is a partially exploded, front elevation view of a dusting tool according to a second embodiment of the present invention.
[0025] FIG. 5 , on the third sheet of drawings, is a view similar to FIG. 3 , but showing a third embodiment of dusting tool;
[0026] FIG. 6 is a plan view of a fourth embodiment of dusting tool;
[0027] FIG. 7 is a top end view of the dusting tool of FIG. 6 ;
[0028] FIG. 8 is a view similar to FIG. 6 , but with the dusting tool rotated by a quarter of a turn;
[0029] FIG. 9 is an enlarged perspective view of the top end portion of the dusting tool of FIG. 6 ;
[0030] FIG. 10 is a plan view of the dusting tool components of FIG. 9 ;
[0031] FIG. 11 is a perspective view of a portion of a digital camera in partially cut-away view, suggesting how the dusting tool of the present invention can be used to clean in a non-scrubbing fashion the exposed surface of the flat sensor lens on the floor of the camera sensor chamber;
[0032] FIG. 12 is a partly schematic side elevational view of the camera sensor chamber of FIG. 11 , suggesting how the non-spinning bristles of the dusting brush of the present invention can reach out to the full peripheral edge portion of the exposed surface of the sensor lens of the camera sensor chamber while avoiding contaminating contact with the adjacent upright walls of the camera sensor chamber; and
[0033] FIGS. 13 to 17 show a prior art roller-type dusting tool, with FIGS. 13-15 being views from a perspective similar to FIGS. 6 to 8 respectively, but showing only part of the handle, and with FIGS. 16 and 17 being views from a perspective similar to FIGS. 11 and 12 respectively, wherein there is suggested that the prior art dusting tool cannot reach the peripheral edge portion of the sensor lens exposed surface.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0034] FIGS. 1-3 show a portable dusting tool 10 for digital camera sensors according to one embodiment of the present invention. Sensor dusting tool 10 comprises a handle member 12 , in turn comprising a casing 14 . Casing 14 defines an elongated main body portion 14 a, and a neck portion 14 b extending from one end of main body portion 14 a.
[0035] Casing 14 , as can be seen in FIG. 2 , is at least partially hollow and in one embodiment may comprise a brush actuator therein, such as an electric rotary motor 16 powered by batteries 18 . Batteries 18 are electrically connected to motor 16 as known in the art, for example by wires (not shown). Handle member 12 is also provided with a switch 20 controlling the selective powering of motor 16 by batteries 18 , and which the user can depress with his finger F (as suggested in FIG. 2 ) to activate motor 16 .
[0036] Motor 16 comprises a rotary shaft 22 connected to and rotating as one with the rotor (not shown) of motor 16 . Shaft 22 extends within the hollow casing neck portion 14 b.
[0037] Dusting tool 10 also comprises a duster member connected to the brush actuator. More particularly, dusting tool 10 is provided with a duster brush 24 that may be operatively coupled to motor 16 through the instrumentality of a brush connector 30 . Brush connector 30 comprises a cylindrical and tubular socket portion 32 , in turn having an open top to allow insertion of the butt end portion of duster brush 24 therein. Socket portion 32 defines four slots 33 extending from its top rim end towards its bottom end and stopping short of the latter. Slots 33 allow the sections of socket 32 therebetween to radially outwardly spread apart as duster brush 24 is inserted in socket portion 32 .
[0038] Moreover, brush connector 30 also comprises an elongated coupling pin 34 tapering towards its outer end, integrally and coaxially affixed to the bottom end of elongated socket portion 32 . The outer free end of coupling pin 34 is centrally and axially bored, and an elongated and cylindrical cavity 35 thus extends coaxially along coupling pin 34 (only shown in FIG. 2 ).
[0039] Brush connector 30 can be coupled to motor 16 by inserting coupling pin 24 in the opening 14 c at the outermost end of casing neck portion 14 b, such that the motor's shaft 22 becomes snugly friction-fitted in cavity 35 of coupling pin 34 .
[0040] As mentioned above, brush connector 30 is preferably operatively coupled to the duster brush motor 16 . Duster brush 24 comprises a shank 25 , made of wood for example, and whose butt end portion 25 a is destined to be received and friction-fitted in the lumen of brush connector socket portion 32 . Shank 25 , at its upper end portion 25 b, comprises a brush head formed of a ferrule 26 holding a bunch of bristles 29 in a tuft 28 . Bristles 29 are destined to be swept about the sensor of a digital camera to pick up and collect dust that may be present thereon, as described hereinafter.
[0041] Importantly, rotary motor 16 is always inoperative when bristles 29 sweep the sensor lens 160 ( FIGS. 11-12 ), i.e. bristles 29 never spin during sensor lens cleaning operations.
[0042] Casing 14 , motor shaft 22 , brush 24 , connector socket portion 32 and coupling pin 34 , are all elongated structures and are arranged coaxially to each other, and define a common longitudinal axis 15 .
[0043] Bristles 29 are preferably made of a synthetic material, e.g. a polyamide material such as Nylon®, but could also be made of a natural material such as feather, wool, or fur. Moreover, bristles 29 are imparted with the following characteristics:
They are preferably soft and resilient. If the bristles are not flexible and resilient enough, they will be prone to breaking during use, and thus broken pieces of bristles may become lodged in the recessed digital camera sensor chamber (not shown) in which the camera sensor lens is nested. Moreover, softer and more resilient bristles are less prone to breaking and are thus more durable. Finally, the bristles need to be delicate enough to be swept about a sensitive surface (e.g. that of a camera sensor) without scratching it. For optimal performance, bristles 29 preferably have a thickness ranging between 40 to 60 μm (micrometers). They have an enhanced electrostatic charge build-up capability. The bristles can readily accumulate electrostatic charges, in order to be able to electrostatically attract dust particles and other macroscopic impurities (e.g. maximum total length of 15 mm) and preferably microscopic impurities (e.g. minimum total length of 1 μm). This characteristic could be imparted to the bristles either (1) during pre-processing, by producing the bristles out of a material having inherent electrostatic charge build-up capabilities; or (2) during post-processing, by applying a chemical or ionization treatment to the produced bristles. Enhanced resistance to chemical substances. This is a desirable characteristic since any alteration in chemical composition of the bristles will affect its capability to electrostatically attract dust.
[0048] The width of the tuft of bristles 28 should be adapted to the size of the optical sensor it is destined to be used on. The tuft of bristles 28 can have a width ranging for example between 1 and 60 millimetres, and should be small enough to fit into the camera's recessed sensor chamber, and it may be large enough to sweep the entire surface of the camera's sensor in a single stroke. Moreover, and as suggested in FIG. 11 , ferrule 26 must have a smaller width than that of the tuft of bristles such that a clearance exists between ferrule 26 and the walls 264 of the sensor chamber 262 when the duster brush 24 is used to sweep the sensor 260 , hence preventing scratching by the ferrule 26 of the sensor chamber walls 264 . For example, a brush 24 with a ferrule 26 having a width of 20 mm, and a tuft of bristles 28 having a width of 24 mm, should preferably be used when cleaning a full frame sensor having dimensions of 36 mm×24 mm.
[0049] The dusting tool according to the illustrated embodiment is made modular in order to be able to receive brushes of different dimensions. This is suggested in FIGS. 3 and 5 , where dusting tools 10 and 10 ′ respectively have differently sized brushes 24 , 24 ′ and complementary brush connectors 30 , 30 ′ respectively. These brush/connector combinations, even though they have differing dimensions, can be coupled to a same handle member 12 .
[0050] To use the dusting tool 10 , it must first be assembled. To do so, the user first inserts batteries 18 in the battery housing if necessary. The user then selects a duster brush 24 of the desired dimensions and inserts the butt end portion 25 a of its shank 25 in the corresponding brush connector socket 32 . The user then connects brush connector 30 to motor 16 by inserting its coupling pin 34 through casing neck portion opening 14 c, and by friction-fitting motor shaft 22 in the coupling pin cavity 35 .
[0051] Prior to dusting a surface such as a camera sensor 260 , it is desirable to rid the tuft of bristles 28 from ambient dust particles that may have gravitated towards it, and/or to remove dust particles that may have remained within the tuft of bristles 29 after a previous use of the dusting tool. It is further necessary to electrostatically charge the bristles 29 in order for them to be able to electrostatically attract and collect dust from the surface to be dusted.
[0052] To do so, the user depresses switch 20 , which activates motor 16 and consequently spins elongated brush 24 along its longitudinal axis at a substantially high speed. This causes the bristles 29 of the brush to fan out radially as suggested in FIG. 2 . The rotation of brush 24 has two effects:
the bristles 29 of the brush move rapidly relative to ambient air molecules. Bristles 29 , as mentioned above, have the inherent capacity to easily build-up an electrostatic charge. Thus, the friction between the rotating bristles 29 and the ambient air molecules causes the bristles 29 to develop an increased electrostatic charge. the dust particles P that may have become lodged between bristles 29 centrifugally accelerate and are expelled from the tuft of bristles 28 .
[0055] Activating motor 16 thus charges the bristles 29 and concomitantly rids brush 24 from dust particles and various other impurities that may be lodged between its bristles 29 , and prepare dusting tool 10 for future use on a surface to be dusted.
[0056] After motor 16 has been deactivated and after rotation of brush 24 has stopped, brush 24 can then be inserted in the sensor chamber 262 of the digital camera 266 , and the non-spinning tuft of bristles 28 can be gently swept across the surface of the camera sensor. Mechanical contact between the distal end portion of the bristles 29 and the digital camera sensor 260 is possible but not essential. Indeed, bringing the tip of the bristles 29 in closely spaced fashion to the digital camera sensor 260 may be sufficient to enable the dust to be attracted by and gravitate towards the electrostatically charged bristles 29 , and to be fully operational to dislodge dust. Since bristles 29 are electrostatically charged, dust particles present on the sensor's surface 260 cling to the bristles 29 of the brush 24 , and are hence removed form the sensor surface 260 .
[0057] Modifications to the above-described embodiment could be made without departing from the scope of the present invention. For example, the dusting tool 10 could be provided with means enabling the user to select various motor speeds for example between 5000 to 20000 RPM in order to vary the rotation speed of the duster brush 24 . Alternately, the duster actuator 16 could be something else than a mere rotary motor; it could for example be a powered actuator selectively activated to engender vibration, rotation, sonication, reciprocating axial motion, or a combination of these actions, of the duster brush 24 including its bristles 29 , in order for the bristles 29 to become electrostatically charged and for impurities lodged between the bristles to be expelled out of the brush.
[0058] Alternatively, the motor 16 could be replaced by an alternate duster actuator that does not require batteries, for example a manual actuator composed of a series of cooperating gears which can be set in motion by manually rotating a crank.
[0059] It is also understood that the brush connector 30 providing modularity to the dusting tool, and releasably connecting the duster brush 24 to the motor 16 , is optional. It is understood that any suitable fastening means, whether they be permanent or quick-release fastening means, could be used to fasten the duster member to the duster actuator. Alternately, the duster brush 24 could be directly connected to the duster actuator 16 in any conventional manner.
[0060] FIG. 4 shows a duster tool 110 according to an alternate embodiment of the present invention. Duster tool 110 comprises a handle member 112 defining a casing 114 , in turn defining an ergonomically shaped main portion 114 a and a neck portion 114 b. Casing 114 houses a motor therein (not shown), the motor having a rotary shaft (not shown) extending at least partially in casing neck portion 114 b and whose rotary movement is controlled by a switch 120 . Moreover, duster tool 110 has a brush member 124 defining a tubular shank 125 (metallic for example), the upper end of which is pressed around a tuft of bristles 128 . Shank 125 fixedly carries, at its bottom end, a connector member 130 (made of plastic for example). Connector member 130 defines a cavity therein (not shown), similar to cavity 35 of brush connector 30 of FIG. 2 , into which can be snugly friction fitted the shaft of the duster tool's rotary motor. In the embodiment of FIG. 4 , brush member 124 and the connector member 130 are fixedly assembled together, and it is this fixed assembly as a whole that is releasable from handle member 112 . Moreover, duster tool 110 is provided with a hollow, elongated protective cap 150 which can be slipped around the brush 124 and secured to the casing 114 by twisting it in place to friction-fit a projection 154 made on the inner peripheral wall of the protective cap 150 within a groove 152 made into the casing neck portion 114 b.
[0061] In still another embodiment of dusting tool 210 shown in FIGS. 6 to 10 , a contoured unibody handle 214 is provided. Socket 232 interconnects handle neck 214 b to duster brush 224 . In brush 224 , ferrule 226 coaxially interconnects elongated shank 225 with the tuft of bristles 228 . Ferrule 226 includes a flattened outer end mouth portion 226 A into which becomes frictionally interlocked the inner end portion of the tuft of bristles 228 . Ferrule mouth portion 226 A further includes two opposite notches 226 B, 226 C, that enable some adjacent bristles to engage therein. Hence, notches 226 B, 226 C enable the tuft of bristles 228 to form an outwardly diverging V-shape, as best shown in FIGS. 6 and 10 . The V-shape of the tuft of bristles 228 optimizes performance of the dust brush 124 , in facilitating access of the bristles to hard to reach areas in the recessed digital camera sensor chamber 262 ( FIG. 11 ).
[0062] Preferably, and as best illustrated in FIGS. 8 , 11 and 12 , the leading edge tip portion 228 A of the tuft of bristles will be tapered, to provide precision in the sensor lens surface to be cleaned while facilitating avoidance of accidental contaminating bristles engagement with the side walls 264 of the sensor chamber 262 of the digital camera 266 .
[0063] FIGS. 13 to 17 show a prior art scrubbing channel 300 , having a handle 302 , a cylindroid roller 304 and a bracket 306 rotatably interconnecting handle 302 and roller 304 . During cleaning operations, roller 304 rotates under power from a spin-inducing electric motor. It is clearly shown in FIG. 17 that as roller 304 moves toward but short of the peripheral edge of sensor lens 260 , roller 304 comes to undesirably abut against the side wall 264 of the camera lens recessed chamber 262 preventing a peripheral edge portion 260 A of the sensor remains uncleaned.
[0064] Clearly, such a prior art scrubbing tool 300 would be inefficient and in fact inoperative in removing dust particles from exposed surface 260 of the digital camera lens sensor at the bottom flooring 266 of this sensor chamber 262 . Indeed, since some dust particles will always remain at peripheral edge 260 A because of the incomplete cleaning operation of scrubbing tool 300 , any motion of the digital camera will inevitably bring about migration of these remaining dust particles towards more central parts of this recessed sensor lens 260 that where previously cleaned, thus rendering useless the previous cleaning in the first place.
[0065] It is further noted that although the present cleaning tool has been described as a cleaning tool for digital camera sensors, the present cleaning tool could be used for cleaning other delicate surfaces, such as optics, i.e. the various glass elements of a camera lens, the mirror of a SLR camera, negative film, transparencies, electro-optical devices such as digital imaging devices, etc. | A method of use of a dusting tool for cleaning the exposed surface of a camera sensor lens in a recessed digital camera sensor chamber while avoiding contaminating contact with the side walls of the camera sensor chamber, the method comprising the steps of providing a non-scrubbing duster member having opposite one and another ends, and a tuft of bristles having electrostatic charge built up therein; engaging the duster member inside the camera sensor chamber; operatively engaging the bristles leading edge tips onto the exposed surface of the camera sensor lens; and manually sweeping the dusting tool bristles leading edge tips over the full exposed surface of the camera sensor lens including the peripheral edge portion thereof but excluding contaminating contact with the side walls of the camera sensor chamber, while the duster member remains motionless relative to the handle. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a division of U.S. application Ser. No. 10/148,503, which was the National Stage of International Application No. PCT/GB00/04624, filed Dec. 4, 2000, which prior applications are incorporated by reference.
FIELD OF THE INVENTION
This invention relates to methods, instruments and devices involved in the repair of damaged tissue present at or on the surface of bone, and/or for filling cavities at the surface of, or in the bones (e.g. condyles of a knee joint), in an animal, including a human being.
Reference will be made hereinbelow to the repair of damaged cartilage. It should be understood that the damaged tissue may be other types of tissue (e.g. bone, skin) including damaged surface of, or defects in, bone itself. Reference will also be made hereinbelow to the repair of cartilage of knee joints and again it should be understood that the present invention may be applied to other body joints and indeed to other organs of the body which consist of or incorporate bone or skin.
BACKGROUND OF THE INVENTION
Defects in the articular surfaces of the knee joint, especially in young active individuals, are currently a focus of interest by orthopedic surgeons. Damage to cartilage which protects joints can result from either physical injure (e.g. osteochondral fracture, secondary damage due to cruciate ligament injury) or from disease (e.g. osteoarthritis, rheumatoid arthritis, aseptic necrosis, osteochondritis dissecans). Osteoarthritis results from general wear and tear of joints and is common in the elderly. Rheumatoid arthritis is an inflammatory condition which results in the destruction of cartilage. It is thought to be, at least in part, an autoimmune disease with suffers having a genetic predisposition to the disease. Orthopedic prevention/repair of damaged joints is a significant burden on the medical profession both in terms of expense and time spent treating patients.
Drug intervention to ameliorate or prevent the onset of cartilage loss are available but do have significant disadvantages.
As an alternative to drug intervention, thus avoiding undesirable side effects, orthopedic surgery is available in order to repair defects and prevent articular damage, thereby leading to serious degenerative changes in the joint. Such changes may result in the need for a total knee replacement which is particularly undesirable in young active individuals with a long life expectancy. If the lifetime of the implant is less than that of the patient, a revision procedure may be necessary. Preferably, such revision procedures are to be avoided, having regard to inconvenience to the patient. Furthermore implant revision procedures are both lengthy and very costly. The use of surgical techniques to repair/replace damaged tissue in joints often requires the removal and donation of healthy tissue to replace the damaged or diseased tissue. There are three sources of donating tissue used in tissue engineering of this type:
i) autograft: tissue is removed from an area of the patient remote from the region to be repaired and grafted to the damaged region to effect the repair;
ii) allograft: tissue is removed from a donating individual, for example a cadaver, and transplanted to the damaged region; and
iii) xenograft: tissue is harvested from another animal species, for example a pig, and placed over the damaged area.
Autografts can be problematic due to the limited availability of suitable tissue and the added trauma to the patient during removal of the tissue from another part of the body to the damaged area. Allografts are limited by immunological reactivity of the host, availability of suitable donor tissue and the problem of transfer of infective agents. Xenografts are even more problematic due to the severe immunological reactivity.
Various techniques for cartilage repair are either in limited current use or under, development but publicly disclosed. The Osteochondral Autogenous Transplant System (OATS) of Arthrx Inc. is arguably the most widely used method. Osteochondral plugs are harvested from a healthy donor and, more particularly, from a site which is claimed to be ‘non-weight-bearing’. These plugs are transplanted into the site of the chondral defect. This procedure has been applied primarily in the knee joint.
However, there are no donor sites in the knee with cartilage of a comparable thickness to that of the deficient site which can be described as ‘non-weight-bearing’ areas. The sulcus terminalis, a frequently used site for harvesting such grafts, is in direct contact with the lateral meniscus at the position of full knee extension, and is therefore a weight-bearing site.
Furthermore, harvesting a large osteochondral plug from the sulcus terminalis may cause the lateral meniscus to become loose and thus impair its load-bearing function. As a result, all the tibio-femoral loads would be transmitted onto the small area of direct contact between the femur and tibia. The resultant stresses could be as high as those arising after meniscectomy with its consequential degenerative changes in the cartilage of the tibial plateau. Such changes have always been regarded as precursors to osteoarthritis.
While the OATS method provides a reasonable technique, including good instrumentation, for transplanting live autogenous grafts for repair of defects in cartilage, it involves introducing potentially damaging effects at other sites with the serious disadvantages discussed above. In addition, harvesting a plug from a donor site creates a new damage in the knee articular surface. For this reason, OATS would not be suitable for the repair of large defects. The use of OATS for small repairs would probably limit the magnitude of the problem discussed above, but it would also limit the indication for using this technique.
The technique known as Autogenous Chondrocyte Implants (ACI) of Genzyme Inc. is a conceptually elegant approach which is gaining popularity, but still in limited use. The procedure is intended for repair of small as well as large irregular defects, and is achieved in a two stage surgery. In the first stage, chondrocytes (cartilage cells) are harvested from the patient and cultured in suspension. In the second stage of the operative procedure, cartilage residue is cleared from the repair site. The site is then covered with a piece of periosteal tissue which is sutured to the perimeter of the repair area. The chondrocytes are then injected into the repair site using a hypodermic syringe, puncturing the periosteum with the needle of the syringe. In a variation of this procedure, the periosteal tissue is applied to the repair site in the first stage of the operation to ensure that, by the time the chondrocytes are due to be injected, an adequate seal has formed between the tissue and the perimeter of the cartilage. There is a high probability of the chondrocytes escaping through the hole of the hypodermic needle in either version of the procedure.
A further problem with the second version of the procedure is the probability of tissue adhesions occurring between the periosteal tissue and the bottom of the repair site.
This procedure does not have an established rate of success and the quality of cartilage in the repair site is questionable. As with the OATS method, this procedure is not minimally invasive. Further, it is an extremely costly procedure. It is also a disadvantage that it requires two operative procedures although the first stage is less invasive as it can be performed arthroscopically.
A procedure proposed by Smith & Nephew involves the production of cartilage discs formed by allogenic chondrocyte culture on an absorbable textile fabric. The discs are grown in the laboratory, the allogenic chondrocytes being cultured on a matrix of a non-woven mesh of a bioabsorbable material, typically polyglycolic acid. When this procedure is completed, the disc is supplied for implantation at the repair site.
An advantage of this method is that it does not involve damage to an intact healthy chondral site since the method uses allogenic sources. Furthermore the procedure is completed in a one stage operation.
The discs can be made in different sizes but there must be a limit to the size of the defect which can be repaired with a loose disc which is merely placed on the repair site. The implant could move freely in the joint. It could wrinkle under the influence of tangential forces and could be completely damaged as a result. This problem would be exacerbated by a low compressive modulus of the material.
A further disadvantage with this method is that the material, being an allograft, runs the risk of viral infection, for example, the HIV virus. Although a small risk, this is an inherent problem with any allograft.
A further problem to be anticipated with this type of graft is the compressive modulus of the material. It may be quite low and the material might be in need of mechanical conditioning (a time consuming and costly process) to achieve a modulus compatible with that of cartilage of the surrounding area.
The Depuy cartilage repair system is a disc of non-woven fabric made of bioabsorbable material that has a hard substrate which enables the implant to be attached to the bone. The shape of the disc allows repair of damaged areas of irregular shapes by using a plurality of discs in a close-packed array. The disadvantages with this system are that the use of too many adjacent hexagonal discs will result in much damage to the bone substrate, and, further the technique may require considerable skill and its application may also be time consuming.
STATEMENTS OF INVENTION
In its broadest aspect the invention relates to a method to repair damaged tissue by forming a groove in said damaged tissue which provides a foundation for the application of material to a site to be repaired wherein said material is anchored in place by securing means.
According to the present invention there is provided a method for the repair of damaged tissue present at or on the surface of bone in an animal, including a human being, the method comprising forming a narrow groove around said damaged tissue, which groove extends into the bone below the damaged tissue, replacing the tissue around which the groove extends by at least one layer of biocompatible replacement material, and anchoring the material to the bone by the use of retaining means extending from the material into the groove.
In a preferred method of the invention said repair extends to the replacement of damaged bone tissue in conjunction with the repair/replacement of tissue attached to bone, e.g. cartilage.
It is well known in the art that damage to joints can extend into bone tissue which requires remedial action to effect a complete repair. Materials used in the repair of bone are also well known in the art and include, by example and not by way of limitation, synthetic bone replacement material (e.g. hydroxyapatite blocks/granules, as well as hydroxyapatite filled polymers); pulverized bone; coral.
Preferably the groove is formed by a reaming device.
Preferably the depth of the groove is a multiple of the thickness of tissue which is replaced. For instance, where the tissue to be replaced is circular then the depth of the groove is preferably at least equal to the diameter of the tissue being replaced. It will be apparent to one skilled in the art that the groove is of sufficient depth to securely retain the replacement material so that it does not get dislodged as the joint articulates. The deeper the groove the more secure the implanted replacement material. However care must be taken to ensure the groove is not too deep since this would represent increased invasiveness.
Preferably the replacement material is in the form of at least one circular, crescent shaped or part circular pad(s) stacked on top of each other. More preferably still said replacement material comprises a plurality of pads. It will be apparent to one skilled in the art that the number of replacement pads used will be determined by the depth of the resultant recess formed after removal of damaged tissue.
It will also be apparent to one skilled in the art that replacement material is broadly construed as materials which facilitate repair such as, tissue (e.g. cartilage, bone, synovium), cells from different origins including chondrocytes, biocompatible gel, comprising tissue/cells, synthetic bone material, coral.
In conditions where extensive damage to tissue has occurred it is preferable to use at least two closely associated pads. For example, and not by way of limitation, FIG. 10 shows a pad arrangement wherein two concentric grooves are formed. A first pad is positioned within the first concentric groove at a site to be repaired. A second, larger concentric groove is formed around the first concentric groove and a second, ring shaped pad, is positioned within the second concentric groove. In this arrangement, two retaining means are used to anchor the pads of replacement material at the site to be repaired.
The material may be bio-absorbable or non-bio-absorbable.
More preferably still said pad provides an increased surface area to which cells adhere and proliferate. More preferably still said pad promotes the differentiation of cells which adhere thereto.
Preferably said pad is adapted to provide a cell culture surface to which at least one of the following cell types adhere, proliferate and/or differentiate: chondrocytic progenitor cells (stem cells); chondrocytes or cartilage-forming cells. Furthermore cells can be genetically engineered to express gene products which, for example facilitate the attachment and/or differentiation of cells which infiltrate the pad.
Ideally said pad is immune silent. It will be apparent to one skilled in the art that it is desirable that the pad does not provoke an immune reaction in the patient.
Preferably the retaining means is in the form of a thin, flexible mesh, more preferably made of a woven fabric.
Alternatively, the retaining means is made of non-woven fabric.
More preferably said replacement material and said retaining means are, over at least part of their length, connected together.
In a further aspect of the present invention, there is provided a set of instruments for the repair of damaged tissue present at or on the surface of bone in an animal, including a human being, the set comprising means for forming a narrow groove around at least part of said damaged tissue, which groove extends into bone below the damaged tissue, means for removing damaged tissue around which the groove extends, and means for anchoring retaining means to the bone so as to retain replacement material at the site from which the damaged tissue has been removed.
Typically, the groove can be made with a, straight or curved punch or with an oscillating saw. It will be apparent to one skilled in the art that the use of an oscillating saw enables the surgeon to make geometric cuts around the damaged tissue thus minimizing the damage to healthy tissue. For example, and not by way of limitation, the surgeon can make a series of angular cuts around a damaged area to surround the damaged tissue. Typically, this results in damaged tissue being sectioned by a polygonal series of cuts as depicted in FIG. 14 .
Preferably, the means for forming the narrow groove is a reaming device.
Typically, the damaged tissue can be excised using a scraping device as depicted in FIGS. 4 and 5 . Alternatively, or preferably, the damaged tissue is removed using a wire brush, FIG. 9 . The use of a wire brush has advantages over the use of a scraping device. Firstly, the abrasive nature of a wire brush although effective at removing damaged cartilage does not have the propensity to damage the underlying bone, which does occur when using a scraping device. Secondly, the wire brush method of removal of tissue promotes tissue re-growth by slight damage to blood vessels in the underlying bone. This promotes local angiogenesis and tissue regrowth.
An alternative to the use of a wire brush to promote angiogenesis is shown in FIG. 16 . Typically the device is a cylindrical rod at the end of which numerous needles are attached. The head including the needles is pressed against the subchondral plate to prick the bone plate at numerous sites and thereby result in a uniform distribution of angiogenesis over the repair site.
Preferably the wire brush is provided with guide means to restrict the abrasive action of the brush to the area of damaged tissue.
In situations where a scraping device is used to remove damaged cartilage, it is advantageous to use guard means to prevent the scraping device damaging surrounding healthy cartilage. Typically, a guard means is located in the groove to abut the scraping device during removal of the damaged cartilage. A guard means is manufactured from any robust, tensile materials to confer protection (e.g. steel, high density plastics).
A further alternative means to remove damaged tissue is a device which comprises a rotatable cutting head comprising a plurality of cutting edges, the cutting head being rotatable relative to a support member which supports the cutting head. An example of such an implement is illustrated in FIG. 17 .
In the embodiment shown in FIG. 17 , the instrument consists of a cutting head that is mounted on the end of a shank, the cutting action is achieved by rotating the shank while the head is moved over cartilage surface and while applying pressure onto the cutting head. The head has a substantially flat end with sharp edged grooves that are formed by making holes in the head in a perpendicular direction to the axis of rotation and by machining of an appropriate amount of material from the end. The end of the instrument being flat skids over the hard and relatively un-deformable surface of the underlying bone (without damaging it), when the instrument reaches the bony surface, after it has removed the cartilage layer.
Alternatively the cutting bead is attached directly to a handle which imparts rotational movement on the cutting head. It will be apparent that the rotational movement can be imparted either by provision of a suitable motor or by simple hand rotation of the handle or shank.
The device illustrated in FIG. 17 can be adapted to provide an implement which can be used as a means to stimulate angiogenesis. The rotating head has a substantially flat end with a few pins protruding above the surface by around 1 mm or less. This instrument could be used after the removal of cartilage from the defective site as described above. The bone scoring instrument would then be brought into contact with the bone and rotated while being moved under pressure, for a short period during which adequate scoring of the bone can be achieved. An illustration of such a device is shown in FIG. 22 .
Preferably the anchoring means comprises a tubular device for pushing the retaining means, in the form of a thin mesh, into the groove. Alternatively, if the groove conformation is polygonal the anchoring means is suitably adapted to facilitate the securing of the retaining means. For example, such anchoring means can be a straight edged blade.
In a further aspect of the present invention, there is provided a replacement element for the repair of damaged tissue present at or on the surface of bone in an animal, including a human being, said element comprising a pad of bio-compatible material shaped and dimensioned to occupy a site from which the damaged tissue, or a part thereof, has been removed.
It will be apparent to one of skill in the art that a replacement element can comprise tissue (e.g. cartilage, periosteum, bone, synovium) or synthetic material. Alternatively, the replacement element can be fluid or gel injected into the recess after removal of damaged tissue. It will also be apparent that combinations of natural tissues and synthetic materials may be advantageously utilized to repair damaged regions. The replacement element or implant may form part of a larger sheet of bio-compatible material which is located on a backing sheet, the element being defined in the sheet and being readily removable therefrom. Preferably the larger sheet includes a covering layer.
In a further aspect, the present invention provides a replacement kit for the repair of damaged tissue present at or on the surface of bone in an animal, the kit comprising at least one replacement element of the invention and means anchorable to the bone so as to retain the replacement element at a site from which damaged tissue has been removed, said retaining means being capable of anchoring location within a groove formed in the bone about said site.
The replacement kit may include the set of instruments of the invention as well as at least one replacement element and the retaining means.
A BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are as follows:
FIG. 1 illustrates cartilage repair by a method of the present invention;
FIG. 2 shows a reamer which is one of the instruments used in the present invention;
FIG. 3 illustrates the operative site after use of the reamer of FIG. 2 ;
FIG. 4 illustrates in section the use of a scraper forming one of a set of instruments of the present invention;
FIG. 5 is a plan view of part of the operative site shown in FIG. 4 ;
FIG. 6 shows the use of a tubular pusher which is another of the set of instruments of the present invention;
FIG. 7 illustrates repair of various sizes and shapes of damaged cartilage;
FIG. 8 illustrates cartilage repair using another embodiment of the present invention;
FIG. 9 illustrates a side view of a wire brush device and guide means for removal of damaged tissue;
FIG. 10 illustrates cartilage repair of a larger damaged region;
FIG. 11 illustrates the combined repair of both cartilage and bone tissue;
FIG. 12 illustrates an integral pad/retaining means;
FIG. 13 illustrates an implement used in the application of a pad and retaining means to a region to be repaired;
FIG. 14 illustrates an alternative groove arrangement;
FIG. 15 illustrates a plurality of pads comprising replacement material for use in tissue repair;
FIG. 16 illustrates an implement from piercing the subchondral bone plate to stimulate angiogenesis;
FIG. 17 illustrates an alternative implement for removal of damaged tissue which comprises a handle, shank and cutting head which includes a plurality of cutting edges;
FIG. 18 illustrates a side view of the cutting head;
FIG. 19 illustrates a further side view of the cutting head;
FIG. 20 illustrates a yet further side view of the cutting head;
FIG. 21 illustrates the removal of cartilage using the implement shown in FIG. 17 ; and
FIG. 22 illustrates an implement for stimulating angiogenesis at a site to be repaired.
DETAILED DESCRIPTION OF THE INVENTION
The invention will now be further described, with reference to the accompanying drawings, and by way of examples only.
Referring to FIG. 1 of the accompanying drawings, there is illustrated part of a knee joint 1 including bone 3 overlaid with cartilage 5 . The method of the present invention involves the formation of an annular space or groove 7 which extends through the cartilage and into the bone terminating within the bone at a level that is a multiple of cartilage depth, for example, four or five times the depth of the cartilage.
Removal of the damaged cartilage from the area of bone defined by the groove 7 results in a space into which is located a small piece or pad of biocompatible material 9 . Pad 9 is shaped and dimensioned to occupy substantially the whole of the space previously occupied by cartilage and the depth of pad 9 corresponds approximately to that of the surrounding cartilage 5 .
FIG. 12 shows an alternative pad arrangement. In this example the pad and retaining sheet form an integral unit which facilitates application to an area to be repaired.
The groove illustrated in FIG. 1 is circular in form. Alternative forms are envisaged. For example, FIG. 14 shows a polygonal groove arrangement. It will be apparent that pads of replacement material are adapted to account for differences in groove arrangement.
Pad 9 is made of a non-woven fabric of a bio-enhancing material which is designed to encourage cell recruitment at a level many times that of untreated material.
Pad 9 may also be bio-absorbable at a rate which is designed to match that of the establishment of a new cartilage layer which is secured to the underlying bone and the surrounding cartilage 5 .
Gene therapy involves the transfer and stable insertion of new genetic material into cells for the therapeutic treatment. Stem cells or pluripotent progenitor cells are suitable targets for gene transfer because the various progeny lineages produced by these cells will potentially express the foreign gene.
Some studies in gene therapy have focused on the use of haematopoietic stem cells. High efficiency gene transfer systems for hematopoietic progenitor cell transformation have been investigated for use (Morrow, J F, 1976, Ann, N.Y. Acad. Sci. 265:13; Salzar, W et al, 1981 in Organization and Expression of Globin Genes, A R Liss, Inc, New York, p 313; Bernstein A 1985 in Genetic Engineering: Principles and Methods, Plenum Press, New York, p 235; Dick J E et al. 1986, Trends in Genetics 2:165). Viral vector systems indicate a higher efficiency of transformation than DNA-mediated gene transfer procedures (e.g. CaPO 4 precipitation and DEAE dextran) and show the capability of integrating transferred genes stably in a wide variety of cell types. Recombinant retrovirus vectors have been widely used experimentally to transduce hematopoietic stem and progenitor cells.
Methods of gene transfer include microinjection, electroporation, liposomes, chromosome transfer, and transfection techniques (Cline M J 1985, supra). Salser et al used a calcium-precipitation transfection technique to transfer a methotrexate-resistant dihydrofolate reductase (DHFR) or the herpes simplex virus thymidine kinase gene, and a human globin gene into murine hematopoietic stem cells. In vivo expression of the DHFR and thymidine kinase genes in stem cell progeny was demonstrated (Salser W et al., 1981 in Organization and Expression of Globin Genes, Alan R Liss, Inc, New York, pp 313-334).
As an alternative, the prosthetic material 9 may be seeded naturally with cells from the joint after the operation.
It may be a useful step in the cartilage repair procedure described, to seed the non-woven pad with autologous cells from the patient, for example, chondrocytes, fibroblasts, stem cell progenitor cells of chondrocytes or fibroblasts. The source of these would be the residual cartilage at the defect site which is removed with the rotatory instrument. A fraction of the cartilage residue will be healthy cartilage. On removal of this residue, it is proposed to decimate it further with tissue disrupting devices which are known in the art or any mechanical or chemical means which can effectively release healthy chondrocytes, fibroblasts or stem cells. A non-limiting example of such a device would be a dounce homogenizer.
With the addition of the appropriate medium to the decimated cartilage removed from the repair site, the result would be a cell suspension into which the repair pad can be soaked for a period after which the pad is implanted according to the invention. The tissue disrupting device can be used with alternative tissue such as synovium harvested from the patient and used in the same manner, except that in this case the cells seeding the pad would be synovial fibroblasts instead of chondrocytes. The advantage of the above is that autologous cells would be used and therefore not rejected by the patient. The use of the pad ensures that much of the cells remain in the site of repair. It is envisaged that the cells would proliferate resulting in inducing tissue that fills the pad in a faster manner than if the latter was not seeded.
Once the material 9 has been positioned at the site from which the damaged tissue has been removed, a piece of thin netting/mesh or tissue 11 is then located in the position illustrated in FIG. 1 . Mesh 11 extends over the pad 9 and into the annular groove 7 into which it is a push-fit. Thus element 11 is a mesh also made of a bio-absorbable material, again calculated to be eliminated at a rate compatible with the growth and fixation of the new cartilage to both the bone and the surrounding cartilage. Element 11 may also be non-woven fabric of a bio-enhancing material, or alternatively can be a piece of tissue, (e.g. periosteum, synovium, fascia, retinaculum).
If cartilage is to be repaired, pad 9 may be supplied in the form of a larger sheet of the same material into which various sizes and shapes of cut-outs have been formed by means of a laser cutting or another suitable means (e.g. stamp, water jet). The shapes chosen are those that are easy to generate or cut using standard instruments. A small cartilage defect is best repaired using a circular reamer with a thin wall having cutting teeth. For an irregular shape, it is preferred to use a plurality of prosthetic elements, each being of a simple shape such as a circle, a crescent or a segment of a circle. These are closely packed to cover the entire repair area.
In an alternative arrangement, repair is effected at a damaged area by the use of at least two concentrically reamed grooves, as illustrated in FIG. 10 . This requires the use of two replacement elements and at least one retaining sheet. A circular pad of replacement material 12 is applied to the inner concentric circle and a ring-shaped pad 13 is applied to the outer concentric circle. Once in place, each of the pads is secured with at least one retaining sheet 14 .
As indicated above, the prosthetic material may form part of a larger sheet which includes a covering or capping layer. The material itself is in the form of a thin layer of a non-woven fabric of a suitable scaffold material which has sufficient strength to be pushed into the circular space previously occupied by the damaged tissue. Typically the material is made of randomly arranged fibers. In the above described embodiment the material is a bio-absorbable material. However in another embodiment the material may be a non-degradable material which is bio-compatible and possesses enhanced surface properties so as to attract tissue growth into the material.
The prosthetic pads themselves can be provided in the form of discs of varying thickness so that the prosthetic scaffold chosen may be of a matching thickness to the adjacent cartilage. As indicated above, it may be supplied in marquetry form with the elements being peeled off when required from a suitable substrate which may be made of, for instance, card. Accordingly the surgeon can select the appropriate elements, including first and subsequent elements, to fill an irregular defect.
The material of the prosthetic elements is the same as that of the covering sheet. The structure is loopy, or random, and stabilized with a bio-compatible adhesive at the sites where the filaments of the material cross or by the entanglement of the filaments.
Referring to FIG. 2 of the accompanying drawings, the operative procedure involves the use of a reamer 15 which is in the form of a circular cross-section tube having a toothed edge 17 at one end. The reamer 15 is provided with a thin steel rod (e.g. Kirschner wire) 19 having located near one end a cylinder 21 of external diameter such that it is a snug fit within reamer 15 . Adjacent cylinder 21 , steel rod 19 has a pointed end 23 enabling rod 19 , and its associated cylinder 21 , to act as a guide for the reamer 15 . In use, the pointed end 23 steel rod 19 is located at the centre of the site which includes the damaged cartilage tissue. Light pressure is applied to the steel rod. Reamer 15 , located around steel rod 19 and cylinder 21 , while being rotated with, for example a power drill, is then subjected to relatively heavy pressure to cut an annular groove which extends through the cartilage and into the bone, as indicated in FIG. 1 .
FIG. 3 of the accompanying drawings shows the position after use of reamer 15 . An annular groove 25 extends through cartilage 27 and into bone 29 to a depth that is a multiple of the cartilage thickness. In this case the annular groove 25 encompasses the defect site 30 and the surrounding cartilage is healthy. FIG. 11 illustrates an instance where both cartilage and bone tissue is repaired. Prior to application of the pad, replacement material is added to damaged bone. Repair of bone tissue can be with bone, (solid or pulverized), coral, or synthetic bone material.
Referring to FIGS. 4 and 5 of the accompanying drawings, there is illustrated removal of cartilage from the area defined by groove 25 . In order to effect this cartilage removal, a metallic guard 31 of part-circular cross section is introduced into the groove 25 so as to protect surrounding healthy cartilage 27 . A scraper device 33 is then used to effect the removal of the cartilage by causing this tool to penetrate through the cartilage layer and then moving it in a direction towards guard 31 .
As stated above, damaged tissue can be removed through the abrasive use of a rotating wire brush as depicted in FIG. 9 . The use of a rotating wire brush as an alternative to the scraping device shown in FIGS. 4 and 5 is advantageous since it is less likely to damage the underlying bone. The brush is provided with a guide means which restricts the movement of the brush to the region of damaged tissue thereby preventing unintentional damage to surrounding healthy tissue.
The implement shown in FIG. 17 is a yet farther device which can be used to remove damaged tissue. FIG. 17 shows an implement comprising a handle 60 which extends into a shank 61 to which is rotatably mounted a cutting head 62 comprising a plurality of cutting edges 63 . Alternatively the cutting head can be rotatably mounted on the handle.
In use the cutting action is achieved by rotating the shank while the head is moved over cartilage surface and while applying pressure onto the cutting head. The head has a substantially flat end with sharp edged grooves that are formed by making holes in the head in a perpendicular direction to the axis of rotation and by machining of an appropriate amount of material from the end.
This instrument is particularly suitable for cutting into a soft material such as cartilage particularly when removing it from the underlying bone causing minimal or no damage to the latter. Referring to FIG. 21 , as the instrument is pressed against cartilage in the direction of Arrow A, the latter being soft, bulges within the groove and is then subject to the cutting action of the sharp edge of the groove. The material removed 34 escapes side-wards through the groove, as illustrated in FIG. 21 , as the instrument moves in the direction of Arrow B. The end of the instrument being flat thus skids over the hard and relatively un-deformable surface of the underlying bone (without damaging it), when the instrument reaches the bony surface, after it has removed the cartilage layer.
In cases of a single repair site, it would be preferable to use a short reamer, which, on completing the groove can be left in situ to act as a guard for the brush during removal of cartilage from the defect site.
Referring to FIG. 6 of the accompanying drawings, once the damaged cartilage has been removed, a prosthetic pad 35 , of a shape appropriate to fill the space previously occupied by the damaged cartilage, is located in that space. A further instrument in the form of a tubular pusher 37 is then used to anchor the prosthetic pad to the bone 29 . Tubular pusher 37 has a wall thickness sufficiently thin to enable it to be pushed into groove 25 . Before this is effected, a circular sheet of fabric netting 39 (made of non-woven fabric) of a diameter of several times that of pad 35 , is laid over the pad so that it extends also over the surrounding healthy cartilage. Pusher 37 is then introduced into groove 25 carrying with it the outer part of netting 39 . Pusher 37 is moved farther into groove 25 until the outer edge of netting 39 is pushed fully into groove 25 . The pusher 37 is then removed leaving the netting 39 jammed into groove 25 . The netting 39 will maintain the pad 35 in place until such time as the pad, whether formed of prosthetic material or ultimately of new cartilage, is itself secured both to the underlying bone 29 and to the surrounding healthy cartilage 27 . The covering sheet fabric may have holes to allow bone and tissue to grow throughout, within the groove thus securing the covering sheet further.
FIG. 13 shows an alternative use of the pusher 37 . In this embodiment the pusher 37 is loaded with a pad and retaining sheet prior to application to the groove. This is particularly suited to the integral pad/retaining sheet of FIG. 12 and advantageously expedites the application and retention of the pad to a site of repair. The retaining sheet is held in position with a retaining ring 40 that can slide along the pusher 37 as this is used to implant the pad in the repair site and introducing the retaining sheet 11 in the annular groove. Thus, by loading the pusher with the implant and retaining sheet it can be supplied to the surgeon in a sterile package, which, on being opened by the surgeon, can be readily used with no need for any further handling by the surgeon. Further, this particular method of packaging would make facilitate implanting the device through small incisions such as those made in arthroscopic or arthroscopically assisted procedures.
The method of the present invention can be applied in connection with a cartilage defect that is confined to an area less than that of a single circular pad. If the defect is large and/or irregular, it can be dealt with by means of a plurality of pads in the shape of circles, ellipses, crescents or other simple shapes. When securing non-circular pads in position, a pusher can be used that, in section, is part circular, for instance, half circular, quarter circular, etc.
FIG. 7 illustrates the use of a single pad which has an, area greater than the whole of the defect area ( FIG. 7A ). FIG. 7B illustrates the use of a circular pad 41 and an adjacent crescent-shaped pad 43 . FIG. 7C illustrates the use of an-elliptical pad 45 as well as a crescent-shaped pad 47 . In practice, the surgeon will choose whichever combination of pads most effectively covers the defect area.
It is feasible accordingly to resurface a substantial area of a knee bone if required.
Referring to FIG. 8 of the accompanying drawing, there is illustrated another embodiment of the present invention. In this case an entire bone plug 51 , which includes the damaged cartilage, is removed from the bone 29 . A prosthetic pad 53 , (to which apply the same attributes of pad 9 previously described), is located on the bone plug in place of the damaged cartilage and an open weave retaining mesh 55 is located around the entire bone plug and pad, thereby securing the pad 53 to the bone plug 51 . The bone plug is then repositioned within the bone as shown in FIG. 8 . The annular space created between the bone plug and the remaining bone is then occupied by the retaining mesh 55 . The bone plug and the host bone will unite through the mesh 55 .
Referring to FIGS. 16 and 22 , devices are illustrated which can be used to stimulate angiogenesis at a site of repair. FIG. 16 shows a cylindrical rod 64 which is provided with a plurality of needles 65 which can be used to pierce the subchondral plate to promote angiogenesis. FIG. 22 shows a device similar in structure to the device in FIG. 17 but with the cutting head replaced with a rotating head 66 which is provided at least one projection 67 fixed to a substantially flat surface 68 . Typically, the projections are approximately 1 mm in height. The application of the rotating head 66 to a tissue surface which has been cleaned of damaged tissue produces an abrasive effect on the bone to score the surface thereby stimulating angiogenesis.
It will be apparent to one skilled in the art that the removable nature of the rotatable heads 62 and 66 is advantageous in so far as replacement heads can be easily and quickly exchanged. The handle 60 or shank 61 can be adapted such that new, unused heads can be fixed to the upper portion of the implement thereby providing a compact storage for the heads which also protects the heads from physical damage. | The invention relates to a method for the repair of damaged tissue present at or on the surface of bone in an animal, the method comprising forming a narrow groove around at least part of said damaged tissue, which groove extends into the bone below the damaged tissue, replacing the tissue around which the groove extends by at least one layer of biocompatible replacement material, and anchoring the material to the bone by the use of retaining means extending from the material into the groove; instruments for use in the repair of damaged tissue and kits comprising said instruments. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION(S)
This is a national phase application under 35 U.S.C. §371 of PCT Application No. PCT/FR2009/052047, filed Oct. 26, 2009, which claims the benefit of French Application No. 08/06011, filed Oct. 29, 2008, the contents of which are expressly incorporated herein by reference.
FIELD OF ART
The present apparatus and system relate to a detachable linking system for two components or similar, intended for ensuring holding in position components one with respect to the other and subsequently authorizing, at a given time, their detachment by a relative movement generated by said system.
BACKGROUND
The term “component” is to be understood in the broad sense thereof and can mean any element, part, device, assembly, sub-assembly, etc. able to be assembled to another identical component or not through said system of the present method, system, and device, up to a given time when it is wanted to detach them.
The detachable linking system can thus find applications in a large number of technical fields.
For example, in a preferred, although not exclusive, application, the system can be integrated into an ammunition including a vector, such as a missile. Indeed, it is known that some parts of the ammunition are detached one from the other upon the ignition and during the trajectory. This is more particularly the case between the base or the bottom of the ammunition and the system for accelerating or propelling the missile linked between them by specific assemblies carrying, in addition to particular equipment, the detachable linking systems being angularly distributed around an internal annular space provided between the base and the acceleration system.
The usually used detachable linking systems generally comprise a linking mechanism between the two detachable components of the assembly, one being stationary, for example a plate, linked to the base, the other one movable, for example a floating support, linked to the acceleration system, and a device for controlling the linking mechanism so as to cause its motion and the detachment of the components.
Such systems are currently of two types.
In the first type, the linking mechanism is a ball-ended spindle, held on the movable support through screwing and having the balls radially projecting at the end of the spindle through the action of a movable central axis of the spindle, being inserted in an abutment inserted on the stationary plate. Upon the operation of the control device, being linked to the movable axis of the spindle via a ring, said axis slides with respect to the spindle and makes grooves arranged on it match with the projecting balls that retract then into the grooves and disconnect the spindle from the abutment integral with the stationary plate. The two components of the base and of the acceleration system are then released and detached one from the other.
Such a system assembly prohibits any angular movement. Indeed, the drawback of an angular shift is to lose contact with all the balls, which may lead to a concentration of efforts on a restricted and too low number of balls, with, in addition, a risk of matting. Furthermore, using several balls has the drawback of only offering one single generator per ball for any contact. Furthermore, crimping the axis with the ring has is of a low dimension, thus restricting the tensile effort for decoupling.
In the second type, the linking mechanism of the system is a breaking one and comprises an element to be broken under the action of the control device driving the mechanism.
In a first case, the element to be broken such as an axis is arranged perpendicular to the tensile effort generated by the device and is supported at the ends thereof by a yoke fastened to the plate and in the centre thereof by a brace being fastened to the floating support and connected to the control device. Breaking occurs at two places of the axis, through shearing.
In a second case, the axis to be broken is arranged parallel and coaxial to the tensile effort being connected at its ends to the plate and to the support.
Breaking is due to the axis being elongated through contraction of the section. The breaking moment is hardly under control.
The breaking effort, through shearing or elongation, is the major drawback of these two assemblies. Furthermore, the uncertainty of the breaking moment is detrimental to a detachment simultaneity, with a risk to cause jamming in the case of an assembly with several detachable linking systems.
Moreover, it is already known from document U.S. Pat. No. 3,014,744 a detachable linking system for two components, comprising a linking mechanism for said components and a control device for said linking mechanism so as to cause said components to be detached.
said linking mechanism being of the elastic deformation type and comprising, according to a longitudinal axis, at least: one rod having a widened end being longitudinally slit and elastically deformable, and fastened, at its other end, to one of said components: axially movable needle having an end being introduced in said widened end of the rod for holding it in an open position and the other end being connected to said control device; and axial hole body, fastened to the other component and surrounding said cooperating ends of said rod and of said needle, being axially linked to the latter and comprising, within said hole, an annular axial abutment against which said widened end of said rod is applied; and said control device being of the axial shift type, according to said longitudinal axis, and acting on said needle of the linking mechanism for moving it away from said widened end of the rod and, through the action of said abutment of the body linked to said shifted needle, for having said elastically deformable widened end switching from its open position to a closed position and enabling the relative crossing of said rod through said abutment of the body.
SUMMARY
The present method, system, and device aim at remedying the drawbacks of the first mentioned systems and relates to an improvement of the detachable linking system of document U.S. Pat. No. 3,014,744 enabling, more particularly, to hold in place the different elements mutually linked, including a possible control for overcoming the manufacturing tolerances, and a detachment during the relative movement at a given selected time, with a minimum effort.
To this end, the detachable linking system for two components of the last mentioned type is remarkable in that said needle is held axially in position with respect to said rod by a deformable ring carried by a component clamping member on said body and applying against an external annular edge of said needle.
Thus, according to the present method, system, and device, the combination is used of the elasticity of the widened end of the rod and of the axial shift of the needle moved by the control device for, on the one hand, linking the two components and, on the other hand, detach them, without any part being broken and with a relatively low detachment effort, as a function of the elasticity of the widened end for switching from its initial open position to its closed position and anyway lower than that required for breaking the prior mechanism. The completely mechanical manufacturing reliability is also to be noticed in such a linking mechanism.
Advantageously, said widened end of said rod has the shape of a longitudinally slit spherical head. And said axial abutment of the body then defines a spherical annular bearing complementary to the spherical head.
Thus, a slight angular clearance is made possible, enabling to absorb manufacturing tolerances from the parts constituting the mechanism and from the associated assembly, and to facilitate the positioning of the system. The contact surface between the spherical head and the axial abutment remains identical as well in every tolerated angular position, contrarily to the ball spindle system. And the contact of the spherical head with the bearing of the abutment is then of the surface type, ensuring a better operation and positioning of the mechanism, instead of being linear according to a generator for each ball of the spindle.
In a preferred embodiment, said spherical head comprises at least two slits arranged in perpendicular longitudinal planes separating said spherical head into four elastically deformable identical quarters, at the centre of which the corresponding end of said needle can be introduced so as to hold it in an initial open position. In order to achieve a much larger elasticity, said slits could extend into the rod, beyond said spherical head.
In another embodiment, said widened end of said rod has a longitudinally slit conical shape.
In particular, said axial abutment is arranged on an annular member mounted around said rod and inserted through screwing on said body. And fastening said rod to the corresponding component preferably occurs through screwing, the end opposed to the widened one being threaded and crossing a hole provided in said component, and a clamping nut providing the fastening of said rod.
Thus, screwing the nut on the rod enables to hold the needle in place through pinching its end by the elastically deformable widened end, pressing against the engaged one of the needle. Furthermore, thanks to the threaded end of the rod, the system can be set according to the distance separating the plate and the floating support of each assembly, which distance can vary as a function of plays and defaults resulting from manufacturing and said relevant assemblies. All plays according to the axis of each system are thereby compensated and, as a result, detachment of the different linking systems provided on the assemblies will occur simultaneously. If there should be a slight tilt, the angular clearance would absorb it.
Furthermore, it should be noticed that said needle is not only pinched by the elastically deformable spherical head, but it is still held axially in position with respect to said rod by the deformable ring carried by the clamping member of the component on said body and applying against an external annular edge of said needle. Thus, should vibrations or the like occur, the holding ring ensures any possible movement and prevent any inopportune unlocking at rest between the needle and the rod.
Moreover, fastening said rod to the corresponding component preferably occurs through screwing, the end opposed to the widened one being threaded and crossing a hole provided in said component, and a clamping nut providing the fastening of said rod.
Moreover, linking said needle to said control device preferably comprises a fastening nut receiving the threaded end of the needle opposite the one introduced in said rod, and a screw of said device.
BRIEF DESCRIPTION OF THE FIGURES
The FIGS. of the appended drawing will better explain how the present method, system, and device can be implemented. In these FIGS., like reference numerals relate to like components
FIG. 1 shows an ammunition and the different constitutive parts thereof.
FIG. 2 shows, in a schematic partial perspective view, detachable linking systems of the present method, system, and device associating two components of the ammunition that are to be detached.
FIGS. 3 , 4 , 5 and 6 are longitudinal sectional views of said linking system of the present method, system, and device according to an exemplary embodiment and shown in its different operating phases from linking of the components, FIG. 3 , until they are completely detached, FIG. 6 .
FIGS. 3A and 5A are enlarged cross sections of the respective open and closed positions of said elastically deformable slit spherical head, taken across the planes and V-V of FIGS. 3 and 5 .
FIGS. 7 and 7A are perspective views of embodiments of the elastically deformable rod of the linking mechanism.
DETAILED DESCRIPTION
The ammunition M shown on FIG. 1 usually comprises several assembled cylindrical parts (or stages), herein referred to as base or rear part 1 , tube or central part 2 and cover or front part 3 , inside which a composite C is located comprising a missile 4 (guidance system 100 and military load not shown) linked to the acceleration and rocking system 5 and that, upon the ignition of the composite and during the flight trajectory, are to become detached.
To this end, in the illustrated and enlarged embodiment of FIG. 2 , the assembly between the base 1 and the acceleration and rocking system 5 of the composite C occurs via detachable linking systems 6 according to the present method, system, and device and being, in such an example, in the number of two. To this end, within the internal annular space 7 being available, between the base and the acceleration system, a specific assembly 8 is provided, comprising two parallel plates, the lower one 9 fastened to the base 1 via braces 10 or similar and the other upper one 11 , referred to as a floating support, connected to the acceleration system 5 through linking systems 6 of the present method, system, and device, as described hereinafter. On such assemblies, particular equipment parts 12 are provided, arranged between said plate 9 and said floating support 11 and also carried on the latter.
As shown on FIG. 3 , the shown detachable linking system 6 comprises a linking mechanism 14 between the stationary plate 9 , connected to the base, and the movable support 11 , connected to the acceleration system and, thus, to the composite C, and a control device 15 of the linking mechanism 14 for leading to the detachment of the base 1 (plate) from the acceleration system 5 (support) of the composite. Naturally, the control devices 15 associated with the assemblies 8 simultaneously act on the linking mechanisms 14 that such assemblies comprise.
In the illustrated exemplary embodiment, the linking mechanism 14 comprises, along a longitudinal axis X-X parallel to the axis of the composite, an elastically deformable rod 16 connected to the plate 9 , a sliding needle 17 connected to the control device 15 and cooperating with the rod 16 , an annular cylindrical body 18 fastened to the floating support 11 and provided with an annular axial abutment member 19 for the elastically deformable rod.
In particular, the rod 16 shown on FIGS. 3 and 7 has an elastically deformable widened end 20 having, in this preferred example, the shape of a spherical head 21 with a diameter larger than that of the rod and having two through slits 22 arranged in perpendicular longitudinal planes for thereby defining four identical quarters or petals 23 . Thus, for providing some elasticity of the end 20 , the slits 22 extend into the rod 16 beyond the spherical head 21 until approximately the third, or even half, of the length of the rod, thereby forming elastically deformable spherical head elongated fingers 24 . The slits 22 arranged in the spherical head 21 allow the quarters or fingers to come closer one to the other in the direction of the axis X-X and, thus, to reduce the initial diameter of the spherical head, occupying an open position on FIGS. 3 and 7 , with a lesser effort, as will be set forth later on. FIG. 7A shows an alternative embodiment of the rod 16 , with a widened end 20 having a conical shape 21 A. The opposite end 25 of the rod 16 has a threaded part 27 crossing a hole 28 provided in the plate and receiving a clamping nut 29 fastening the rod 16 to the plate according to the axis X-X. For holding the rod (in rotation) upon clamping the nut with a wrench or similar, the threaded part 27 ends with a cylindrical land nosepiece 26 . Of course, before being assembled to the plate, the body 18 and the abutment member 19 are arranged around the rod 16 .
As to the needle 17 , it has an elongated cylindrical shape, with one end 30 being smooth and introduced through fitting into the cylindrical internal channel 31 defined by the spherical head 21 deformable elongated fingers 24 of the end of the rod 16 . The introduction distance of the smooth end 30 is substantially equal to the spherical head 21 , so that the latter is held in an initial open position, and this distance is defined by an external shoulder 33 of the smooth end 30 , axially abutting against the spherical head widened end 20 of the rod. Thus, when the smooth end 30 of the needle is inserted into the deformable spherical head 21 resting on the annular axial abutment member 19 , as seen later on, the plate 9 and the floating support 11 of the assembly 8 are locked to each other.
The opposite end 32 of the needle is threaded so as to engage, through screwing, into a fastening nut 34 connecting the control device 15 to the needle 17 via a screw 35 , having its threaded rod 36 cooperating with the nut so as to abut against the threaded end 32 of the needle. Thus, the needle 17 and the screw 35 make up a whole, through the linking nut 34 . It could be furthermore noticed, on FIG. 3 , that there is an axial play J between the control device 15 and the head 37 of the screw 35 so as to absorb some longitudinal movements due to the external environment of the assembly.
The cylindrical body 18 comprises art axial hole 40 being crossed by the needle 17 and surrounding the cooperating ends, respectively with a spherical head 21 of the rod and the smooth one 30 of the needle. Such a cylindrical body 18 is centred in the floating support 11 being fastened on it, as will be seen later on, and carries, according to the axis X-X, the annular axial abutment member 19 .
In particular, such an annular member 19 has its axial hole 41 extending that of the body, for the rod crossing, which hole 41 ends on the needle side with a bearing or a spherical cup 42 against which the spherical head 21 of the rod applies. Of course, the dimensions of the bearing 42 and of the head 21 match with each other. Thus, the contact between the abutment member 19 and the elastically deformable rod 16 occurs via an annular spherical surface portion authorizing for a relative angular clearance of the rod 16 connected to the plate 9 with respect to the body 18 connected to the floating support 11 in all directions like a knee hinge. It is thus understood that clamping the nut 29 of the rod 16 on the plates tends to draw the rod against the plate and thus to press the elastically deformable fingers 24 against the spherical bearing 42 and accordingly to pinch the smooth end 30 of the needle.
Such an annular axial abutment member 19 is mounted through a screwing link 48 in the axial hole 40 of the body 18 and the latter has an external annular shoulder 43 forming a resting plane against which the floating support 11 applies so that the threaded end 44 of the body, coming from the annular shoulder 43 and opposite that receiving the abutment member 19 , crossing a crossing hole 45 provided in the support 11 and emerging above the latter.
A retaining nut 46 is then screwed on the threaded end 44 of the body and applies via its transversal edge 47 on the support 11 , pinching it and immobilizing it against the body.
Furthermore, when the systems 6 are used in severe environments for example with strong vibrations, each linking mechanism 14 could comprise a ring 50 for holding the needle 17 in axial position with respect to the rod 16 despite its smooth end 30 being pinched by the elastically deformable fingers 24 . To this end, on the needle, an external annular shoulder 51 is provided, on which the ring rests, being in turn close, on the other side, to an internal annular shoulder 52 arranged inside the retaining nut 46 . Such a ring 50 is advantageously deformable and prevents the needle 17 from axially moving back, preventing any inopportune locking before the missile is launched.
As to the control device 15 of the system 6 , it moves axially and could be, for example, a driver or similar associated with the movement of the system 5 .
Upon the missile being ignited, the operation of the detachable linking system according to the present method, system, and device occurs as follows.
First of all, in the above mentioned application, the different linking systems 6 provided on the specific assemblies 8 connecting the base 1 to the acceleration system 5 of the missile are all in the same position and set appropriately. Namely, as shown on FIGS. 3 and 3A , each needle 17 of the linking mechanisms 14 is implanted into the spherical head 21 in abutment against the member 19 and thereby prevents any closer shift of the spherical quarters of the head, locking mechanically the rod 16 fastened to the plate 9 to the remainder of the mechanism connected to the floating support 11 under the action of the elastic fingers 24 in an open position against the spherical bearing 42 of the annular axial abutment member 19 . The assemblies are thereby locked.
As now shown on FIG. 4 , when the control device 15 starts its axial shift or its translation according to the arrow F of the axis X-X, it first neutralizes the play J present between the latter and the head 37 of the linking screw 35 with the mechanism, that is the needle, being required for absorbing possible longitudinal axial movements, caused by the external environment.
Continuing its axial shift according to the arrow F, the control device 45 , via the screw 35 , draws the needle, resulting in, on the one hand, the holding ring 50 becoming deformed which, under the action of the tensile effort caused by the axial shift of the device according to the axis X-X, retracts from the annular shoulder 52 of the nut 46 and, on the other hand, the smooth end 30 of the needle of the defined central channel 31 for the quarters 23 of the elastically deformable spherical head 21 of the rod 16 moving hack. The fingers 24 always occupy their initial open position, but are no longer locked in such a position by the needle as shown on FIG. 4 . Sliding of the needle 17 according to the arrow F continues until its external annular shoulder 51 , driving the ring 50 , becomes contacted by the latter, with the transversal bottom 53 of the retaining nut 46 .
The systems 6 are then locked, as the spherical heads 21 are simply carried by the abutment members 19 , but are not detached.
As a result of the control device 15 being driven, the needle 17 continues to slide according to the arrow F along the axis X-X and drives with it, via the axial link between its external annular shoulder 51 and the transversal bottom 53 of the nut, the assembly comprising the nut 46 , the floating support 11 , the cylindrical body 18 and the axial abutment member 19 being integral with each other.
At that time, as shown on FIGS. 5 and 5A , under the action of the spherical bearing 42 of the member 19 moving apart from the rod 16 , the elastically deformable fingers 24 progressively radially converge one to the other, in the direction of the axis X-X until they touch each other when the wall 54 defining the axial hole 41 of the annular abutment member 19 reaches the spherical head 22 of said rod. The latter then occupies the closed position. The detachment is then achieved.
The movement of the control device continues according to the arrow F until the complete detachment represented on FIG. 6 , between the floating support 11 carrying, in addition to the equipment 12 , the above mentioned assembly of the linking mechanism 14 , and the plate 9 on which the rod 16 is fastened, with the head thereof having elastically returned to its initial open position.
As already been reported, such a detachable linking system 6 could find applications in a lot of other fields. Such dimensions and shapes could adapt to any material type requiring decoupling. Moreover, no particular maintenance (greasing, replacement, etc.) is to be provided and the reliability thereof is that of a completely mechanical system without any electrical/electronic control. Furthermore, after being positioned, it is possible to dismantle and then to assemble the system again. | The system of the present method, system, and device comprises a mechanism for linking components including: a rod having a widened and elastically deformable end; an axially movable needle; and a body surrounding the interacting ends of said rod and said needle; and a control device acting on said needle and capable of switching said widened elastically deformable end from an open position to a closed position. | 5 |
[0001] This invention relates to paper coating and paper coaters, and more particularly to short dwell time paper coating and short dwell time paper coaters, also referred to as a short dwell time applicator (SDTA). SDTA's are suitable for applying coatings to a moving surface, be it directly on a web or roll, such as a roll in a film coating application. Background of the Invention Short dwell time coaters, SDTA's, and the method were developed by Consolidated Papers, Inc. and are shown in U.S. Pat. No. 4,250,211 and No. 4,512,279, which are herein incorporated by reference. While this coating method and coater have been adopted worldwide, this coating method and coater is subject to developing streaking which shows up on the paper generally at high speeds say at 3500 ft./min. and certainly by 4500 ft./min, depending on coating weight applied, i.e., the higher coating weight the greater the streaking tendency. Much has been written about this streaking and many attribute it to vortices that develop in the coater when it is operated at higher speeds. Much has also been written in attempts to solve this streaking and/or vortices problem. Still others suggest that uneven web wetting when the paper web first enters this type coater also can result in non-uniform coating. Again, various attempts have been made to try to make the coated web streak free and web wetting more uniform.
[0002] For example, see U.S. Pat. Nos. 4,369,731; 4,839,201; 4,452,833; 4,780,336; and 4,834,018 and other patents, WO 97/08385 all of which are herein incorporated by reference. Also see the Eklund and Norrdahl article entitled “The Characteristics of Flow in a Short-Dwell Coater” appearing in the Tappi Journal May 1986, pages 56-58.
SUMMARY OF THE INVENTION
[0003] The coater and method of the present invention addresses the foregoing difficulties, particularly at higher web speeds and provide a coating process and coater which directs the coating upward onto the sheet in a uniform manner and provides a flow member or modifier in the application zone of the coater to specially direct the flow about the coater to minimize or eliminate the effect of vortices and streaking.
[0004] The coater of the present invention comprises a coating body having an incoming coating supply or metering channel. The body terminates at its upstream end to form an application zone. At the front or upstream side of the coater a spaced gap with a moving surface, be it a web or roll surface, is provided to accommodate coating overflow which functions like the overflow in a short dwell coater to exclude air and helps form a liquid seal. At its downstream end the coater has a doctoring means such as a flexible blade, a bent blade and/or doctor rod, grooved or plain, for doctoring the coating to the desired amount or level on the web or roll surface. As is noted, the coater body forms between its upstream edge (the gap) and downstream edge (the doctor), an application zone. Situated within the application zone is a shaped, streamline flow modifying element or member about which the coating can flow. On the upstream side of the inlet channel, a downstream turn or bend is formed to first direct the flow one direction (opposite the direction of web or roll surface travel) and then another turn or change of direction (upwardly toward the web or roll surface). As shown in FIG. 1, if the upstream side is on the left, the inlet channel first turns to the left then to the right (up) onto the moving surface, be it web or roll. The directing of the flow about the second or upward curve or turn, just before the web or roll, tends to displace any air bubbles in the coating to the inside of the turn, or away from the sheet or roll surface and the upward action or movement of the coating toward the web or roll tends to help insure uniformly wetting of the web or roll surface.
[0005] The coating is then further drawn over the top (or supply) side of flow body around the tip by the rapidly moving ( 3500 feet per minute or more) web or roll surface, and then meets the doctor. The doctor only lets a desired quantity of coating to uniformly pass downstream, which causes much of the coating, preferably a majority, and more preferable several times more coating than is applied to the web, to flow down the downstream (or return) side of the flow modifier. It is believed with this construction the majority of flow is clockwise (as shown in FIG. 1) around the flow modifier element. At the remaining portion or downstream or return side of the flow modifier element, the downwardly flowing coating which is given velocity and momentum by the moving web or roll surface, merges with the newly introduced coating moving from the inlet channel toward the application zone. Preferably, the distance between the downstream side of the coater body forming the gap and the upstream side of the flow modifier is adjustable to help set up the desired flow ratios and gap for the liquid seal in the gap and to insure a metering gap just before the coating leaves the metering slot, starts to flow around the modifier and approaches the moving web or roll surface. Further, the flow passages and flow member are shaped to cause the flow to be restricted or metered as discussed, to provide more uniform cross web distribution of the coating, and to minimize the total amount of newly introduced coating needed to meet the coater's flow requirement. To effect this, narrowing, tapering surfaces toward the downstream direction are provided. It is believed that with the present invention the amount of coating supplied can be reduced 32-54% as compared to a conventional SDTA coater, like that shown in the 4,250,211 patent. For example, a conventional SDTA may need 2.2 gallons of coating supplied per minute per inch of width, while with the present invention that could be reduced to 1.0 to 1.5 gallons per minute per inch of width. With an application zone length of about 2.5 inches and dwell times of 0.0100 to 0.0016 seconds, this represents a web or roll surface speed of 1250 to about 7800 feet per minute (fpm). This is a good operating range for the invention when it is incorporated in size press, film coater or web coating applications. Typical operating ranges for a size press or size press process is 1000 to 6500 fpm, film coater or film coater process is 1000 to 6500 fpm, and direct web coater or coating process is 1000 to 8125 fpm. The advantage of the present invention is its broad operating range from low speed to very high speeds. This is unlike the prior SDTA applicator which is not suitable for such high speeds because of vortices and/or streaking.
OBJECTS OF THE PRESENT INVENTION
[0006] It is an object of the present invention to provide a coater and coating method which operates at high speeds, while minimizing or eliminating streaking the paper web.
[0007] Another object of the present invention is to provide a coater and coating method which minimizes the effects of vortices, but minimizes total coating flow required.
[0008] Yet another object of the present invention is to provide a short dwell time coater and method which minimizes vortices and/or eliminates or diminishes streaking.
[0009] A still further object of the present invention is to provide a coater and coating method which utilizes a flow modifier element or member to cause a smooth, uniform flow to minimize streaking and/or vortices formation.
[0010] Yet a further object of the present invention is to cause the coating to first move downstream and then curve or turn toward the web before entering the application zone.
[0011] Still a further object of the present invention is to provide narrowing, tapering surfaces to provide uniform cross web coating distribution.
[0012] Still a further object is to provide a coater or method for use in coating a moving web or a roll of a film coater or size press.
[0013] A further object is to provide a coater of the present invention which can directly coat paper and/or indirectly coat paper when such coater is provided as part of a film coater or size press.
[0014] These and other objects of the present invention will become apparent from the following written description and accompanying figures of the drawings.
DESCRIPTION OF THE DRAWINGS
[0015] [0015]FIG. 1 is a cross sectional view of a coater of the present invention and illustrates the method of the present invention and the flow paths of the coating within the coater.
[0016] [0016]FIG. 2 is a sectional view taken along the line 2 - 2 of FIG. 1, illustrating how the coating can flow around the flow modifying element or member and one way that element can be mounted in the coater.
[0017] [0017]FIG. 3 is a view of the coater of the present invention incorporated into a film coater having a moving roll surface which receives the coating and in turn transfers the coating to a moving web.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] Referring to the drawings, there is shown in FIG. 1 an applicator or coater portion 18 of a paper coating machine, having a leveling doctor 19 . The applicator 18 is carried on a main beam indicated generally at 20 , extending parallel to and coextensively with a rotatable or movable support or backing roll 22 which rotates in the direction shown by an arrow 24 and supports a moving surface, in this instance, a web of paper 26 , during its travel through an application zone. As noted in FIG. 3, the applicator or coater can also apply coating to a moving roll surface 26 ′ or 27 ′, and from there to a web 108 in a film coating application. Referring back to FIG. 1, the beam 20 has rear and front wall members 28 and 30 forming a chamber 32 therebetween for reception of liquid coating material under pressure from a source of material (not shown), and the walls 28 and 30 converge upwardly toward one another and define a first metering slot 34 which extends upwardly adjacent to and facing the web 26 and support surface of the roll 22 . Although not shown, the front wall 30 may be or otherwise, pivotally mounted relative to the rear wall 28 to permit the chamber 32 to be opened for cleaning and also to adjust the width of the metering slot 34 .
[0019] A doctor in the form of a roll or, in this instance, a coater blade 36 is mounted at the downstream end of the application zone. The application zone is about 2.5 inches in length along the circumference of the roll or web surface. In this instance, the flexible blade 36 is held against a rearward surface 37 on the rear wall 28 by a pneumatic tube 38 which is expandable by the introduction of fluid or air under pressure therein to press against the blade. The coater doctor blade extends above the metering slot 34 into engagement with the web supported on the roll 22 and serves to meter and level the coating applied onto the surface of the web, or in case of film coating on a size press, onto the surface 26 ′ or 27 ′ of the roll 104 or 102 (see FIG. 3).
[0020] An orifice plate support 40 is mounted on the front wall 30 , and adjustably supports an orifice plate 42 which extends toward the roll surface 22 or supported web 26 and generally parallel to the coater blade. The orifice plate 42 has a free tip or edge 44 which is juxtaposed to but spaced slightly from the roll surface or web, such that an adjustably sized space or gap 46 between the edge 44 and the moving surface is formed. The gap is relatively small and less than one inch and usually (anywhere from {fraction (1/16)} to ⅜ of an inch (1.5 to 10 mm) with about {fraction (3/16)} of an inch (5 mm) being preferred). The gap forms the upstream end of the application zone.
[0021] At the two ends of the coater, the spaces between the coater doctor blade 36 and the orifice plate 42 are sealed off in a manner known in the art by flexible edge dams or deckles (not shown), which seal with the upper edges of the wall members 28 and 30 and the orifice plate support 40 , the doctor blade 36 , the orifice plate 42 and the roll surface or supported web 26 , thereby to define a coating material application zone 48 downstream (with reference to coating flow) from the chamber 32 and the metering slot 34 .
[0022] In operation of the applicator thus far described, coating liquid is introduced under sufficient pressure and in sufficient quantity to substantially completely fill the chamber 32 , the metering slot 34 and the application zone 48 defined by the doctor blade 36 , the orifice plate 40 and the end dams, to cause a continuous, copious flow of coating material reversely of the direction of web travel through the narrow space or gap 46 defined between the upper end 44 of the orifice plate and the web or roll surface. This forms a liquid seal at the front of the application zone between the edge and the moving web or roll surface and causes the coating liquid to be applied to the web or roll surface in a very narrow transverse band under a constant positive pressure. The copious excess of coating liquid that flows through the orifice gap 46 reversely of the direction of web or roll surface travel forms a non-abrasive liquid seal with the web or roll surface at the upstream (relative to web travel) or forward edge of the coating application zone; causes the coating liquid in the application zone to be maintained under pressure and to be applied to the web or roll surface under pressure; seals off the forward edge of the application zone against entry of air and foreign matter; strips air from the high speed web or roll surface and helps prevent such air from causing streaks or skips in the coating on the web or roll surface; and permits the downstream coater doctor blade 36 to doctor the coating liquid while the liquid is held under pressure. Specifics as to pressures, times of applications, blading or doctoring pressures and/or other operating conditions can be determined from the patents incorporated herein by reference. For example, application times can be from 0.0100 to 0.0016 seconds; application pressures from 0.25 to 2.5 and doctoring pressures to 9 pt; while supply coating flow is reduced 22 to 40% relative to a conventional SDTA. Of course, web speeds for the present invention may be higher say from 3,500 ft./min. or higher say to 5,000 ft./min. or above as previously mentioned.
[0023] A doctoring tip 50 of the coater blade 36 is beveled or honed to an angle, which is the operating angle of the blade. The lower end of the blade is clamped in its seat by the pneumatic tube 38 , and the bevel is preferably maintained flat or tangential to the web 26 or roll surface at its point of contact, and to this end adjustment means (not shown), but as described in said U.S. Pat. No. 4,250,211 or any other known conventional adjustment means, are provided for adjusting the angular orientation of the coater head or main beam 20 with respect to the web. For example, actuators such as provided by Measurex known as AutoCoat, now Honeywell Precoat Systems could be provided. Likewise, a Roll Flex doctor rod could be provided instead of a blade. In this instance, as shown in FIG. 1, the blade tip 50 is urged or loaded against the roll surface or supported web by a second pneumatic tube 51 mounted in the block 90 on the rear wall member 28 , toward the upper end of the blade. The amount, quantity or weight of coating applied to the web or roll surface is influenced by the force of the blade tip against the web or roll surface and by the angle that the tip makes relative to the web.
[0024] The applicator is generally referred to as a short dwell time applicator. When used directly on a web, this type applicator avoids saturation of the web with coating material, thereby to prevent the water portion of the coating composition as well as the water solution or dispersible materials contained therein from migrating into the web at a more rapid rate than the pigment, the web (or roll surface in the case if a size press or film coater) is exposed to the coating material in the application zone 48 for only a relatively short time. To this end, the width of the application zone in the direction of web travel, as well as the speed of travel of the web through the zone, are controlled to provide a relatively short dwell time of the web within the zone. However, a difficulty which occasionally is encountered in prior art SDTA's is that, depending upon the nature of the paper web and the coating composition, the coating may fail to fully penetrate and fill voids and valleys in the surface of the web. Additionally, due to the speed of the web, induced coating flow and coating characteristics, vortices can and will form in any free spaces. That is, the larger the free space, the greater the tendency to form vortices in the application zone. It is believed that the formation of vortices can cause streaking of the produced paper.
[0025] One way to limit streaking is to limit vortice formations. It is believed limiting free space in the application zone can contribute to reduced vortices and/or streaking. While others have tried this approach, there has not been overwhelming success. It is believed that the manner and way the space is limited and manner and way the coating flow is conducted can have increased success. To help overcome the aforementioned disadvantage, an internal flow member 54 is provided within the application zone 48 for more uniformly applying coating material on the web while the web or moving roll surface is within the zone. The flow member must be and is supported by a holder portion 56 , which in turn may be carried between the front wall 30 and the orifice plate support 40 for movement toward and away from the web, thereby to adjust the position of the flow member 54 relative to the web or roll surface. To permit flow through the holder 56 , a plurality of slots or holes 58 are provided. These openings should be large enough in flow area not to unduly restrict the flow (say 2-3 times that of the metering gap 34 ). For example, they could be drilled holes {fraction (5/16)} to ¾ inch in-diameter spaced say ½ inch apart. They should not unduly weaken the support for the flow member. These holes or openings 58 align with the chamber 32 and supply channel to the application zone.
[0026] Here as the flow member 54 is supported off the orifice plate 42 , it will move with the same, permitting adjustment of the gap the tip 63 makes with the web or roll surface.
[0027] In an alternative construction, the flow member could be supported off of the beam 28 , but such might not be adjustable or would require a separate adjusting means.
[0028] The flow member 54 and its holder 56 divide the application zone 48 into a leading or upstream (relative to the web) application zone or chamber 60 and a lagging or downstream (relative to the web) application zone or chamber 62 , with communication between the upstream and downstream chambers being established at the web or roll surface by passing over the tip 63 of the flow member (which is closely adjacent, 0.032 inches to 0.125 inches (0.81 mm to 3.2 mm), but not touching the web or roll surface) and at the bottom of the flow member through the plurality of openings (or alternatively elongated slots) 58 formed through and transversely of the flow member holder 56 .
[0029] The flow member 54 is located so that initial flow out of the chamber 32 and metering slot 34 first turns upstream relative to the web (to the left as shown in FIG. 1). To assist this initial turn, a lower extending, directing tip or edge 70 is provided at the bottom of the flow member. After leaving the passage formed by slots or opening 58 , the flow encounters a nearly right angle curve 73 and turns upward (as shown in FIG. 1) to cause the flow to then head directly up toward the web (or roll surface). Again, this passage (formed between walls 74 and 76 ) tapers or narrows as it flows toward the web to provide a secondary metering slot to further help diffuse any nonuniform cross web distribution, such as caused by passing through the plurality of the slots or opening 58 . The curved surface 73 , 74 also helps cause any air bubbles in the coating to migrate toward the inside of the curve (toward wall 76 ), and thus away from the moving web (or roll surface) to help keep air bubble imperfections off the web (or roll surface). This curved surface 73 , 74 works in a similar manner to the curved surface disclosed in U.S. Pat. No. 5,436,030, which is incorporated herein by reference. It is also important to keep the velocity in this turn high enough and the viscosity of the coating low enough to facilitate such bubble migration. Velocities of 100 to 1000 feet/minute and viscosities of 1500 to 8000 centipoise (cps) Brookfield at 20 rpm would seem suitable, with about 300-700 feet/minute and 2000-4000 cps preferred.
[0030] As is shown, the distance between the surface 74 and flow member 54 can be independently adjusted to provide a desired gap. To accomplish this, the adjustment mechanism comprising the hinge portion 80 and adjustment and retention screws 82 and 84 are provided. By turning screw 82 downward in its threaded bore 86 , the distance between 74 and 54 may be closed. By turning the screw in the opposite direction, it may be opened, the hinge section springing it upward. Tightening or loosening the locking screw 84 in its threaded bore 88 holds the surface 74 and tip 44 in position. It of course needs to be loosened to make an adjustment to reduce the distance between 74 and 54 .
[0031] Because of the present invention, the flow to the coater of the present invention is between 1-1½ gallons per minute per inch of width. Normal SDTA's require 1.75-2.2 gpm/inch of width. Thus the input flow is different from prior art coaters having flow members therein in that it is considerably smaller, resulting in smaller size coating supply components and lower installation and operating costs.
[0032] The flow then moves up a sloped surface 78 of the flow member which also converges toward the web or roll surface in the downstream (web direction) to cause yet another metering effect to provide more uniform distribution of the coating across the web. Again, this tapered surface is different from many prior art devices which showed surfaces, more or less parallel to the web which would effect undesirable and increased shearing which can set up and may increase unwanted vortex formation. The tapering surfaces of the web or roll and 78 in the present invention help minimize any shearing effect in the application zone and thus minimizing or eliminate formation of vortices and/or streaking. The flow then moves across the doctor or tip 63 . Much of the coating flow is forced downward by the momentum provided by the moving web or roll surface down to return and merge with the incoming coating flow from slot 34 . Other portions of the coating are carried by the web or roll surface to the doctor 36 , in this instance a blade, wherein part is doctored off and some passes beneath the tip 63 to be applied to the web or roll surface.
[0033] In operation of the applicator with the internal flow member 54 and its holder 56 , coating liquid is supplied under sufficient pressure and in sufficient quantity to substantially fill the chamber 32 , the metering slot 34 and the upstream and downstream portions 60 and 62 of the application chamber 48 , thereby to substantially fill the application chamber with a supply of coating material for application on the surface of the web or roll.
[0034] Thus, as the paper web or roll surface 26 travels through the application zone in the direction indicated by the arrow 24 , it receives an initial coating on its surface at or before the gap 44 within the upstream application chamber 60 which coating is partially metered by the internal flow member 54 as the web or roll surface moves toward and by the tip 63 (which does not contact the web or roll surface) from the upstream chamber 60 and into the downstream chamber 62 . Consequently, by the time the web or roll surface enters the downstream application zone 62 , it has already been initially coated and partially metered. Then, within the downstream application chamber, the coating is doctored by the coater blade 36 to the desired coating weight as the web or roll surface exits from the downstream zone.
[0035] Because of the internal flow member 54 , during the relatively limited time of passage through the application zone 48 , coating material is applied and partially metered on the web or roll surface. The internal flow modifier meters the initial coating applied in the upstream application chamber 62 , and produces pressure and limits shear on the coating material which helps to improve coating of the web or roll surface. Subsequently, the coater blade 36 meters and levels the film of fresh coating on the previously coated and partially pre-metered web or roll surface to complete the coating process. This operation is believed, will produce a very uniform and smooth coated surface on the web or roll surface without streaking at higher operating speeds, and if desired, a somewhat denser coating layer may be provided on the web without the disadvantage of subjecting the web to a prolonged dwell or soak time. The use of the flow member also is believed to eliminate or reduce the likelihood of the formation of vortices and streaking. The placement of the flow member and the use of the several tapering surfaces to provide additional cross machine metering and pressure application also help provide a more uniform coating. The tapered surfaces and secondary metering actions are particularly important in eliminating any nonuniform distribution. Also, the limits on shearing and additional pressure provided by the top tapered surface of the flow member with the moving surface (web or roll) helps eliminate vortices and provides more uniform coating application.
[0036] Referring to FIG. 3, a film coater 100 is shown utilizing the present invention. The film coater has two rotating rolls 102 and 104 providing a nip 106 between the two rolls 102 and 104 . A web 108 moves between the two rolls 102 and 104 and coats the web with coating material put on the rolls by the applicators 110 and 112 of the present invention. These applicators 110 and 112 are similar to the applicator 18 shown in FIGS. 1 and 2. The applicator 112 is shown fitted with a doctor blade 114 , while the applicator 110 is shown fitted with a doctor roll 116 rotatably mounted in a doctor roll holder 118 . It should be understood that any of applicators 18 , 110 or 112 could have either a blade or roll type doctor.
[0037] It should be understood that this coater could also be used in conjunction with a size press arrangement wherein an applicator like the present invention applies coating directly to a web moving on a backing roll, while a second applicator applies coating to the moving roll surface of the backing roll which is then subsequently transferred into the opposite side of the web.
[0038] While the invention has been described in conjunction with a moving surface, that surface can be a moving web, as in a short dwell coater, or a moving roll surface as in a film coater.
[0039] While several embodiments of the invention have been described, various modifications, other embodiments and equivalent elements and steps thereof may be devised by one skilled in the art without departing from the spirit and scope of the invention, as defined in the appended claims. | An improved short dwell type coater and method are provided. The coater can coat a web directly or a moving roll surface as in a film coater or size press. The flow path in the coater includes a flow modifier shaped to have the introduced coating first turn upstream relative to the web or roll surface, then turn across a curved surface toward the web or roll and around the flow modifier. The flow then converges toward the top of the flow modifier and passes the tip of the flow modifier. Some flow remains on the web or roll and is subsequently doctored, while most is turned away from the web or roll and merged with the incoming flow. A gap filled with coating overflow provides a liquid seal. This coater and method use coating, reduce vortices and streaking, and can operate at higher speeds. | 3 |
FIELD OF THE INVENTION
This invention relates generally to overhead doors, and in particular, to an overhead door with stacking panels.
BACKGROUND OF THE INVENTION
Overhead doors are utilized to provide security and access control in institutional, industrial and commercial buildings. They fall into two general design categories: coiling doors and segmented panel doors. Each have their advantages and disadvantages making one better suited for a given design application.
Often times a segmented panel door is better suited for a particular application but cannot be used due to the increased space requirement needed to house the panels once the door is opened. Various attempts have been made to reduce the profile of the opened door, such as stacking the panels as taught in U.S. Pat. No. 4,460,030 to Tsunemura et al. and in U.S. Pat. No. 5,685,355 to Cook et al.
The stacking design of those two patents, as do all other known panel stacking designs, maintain a connection point between the panels such as a hinge, or otherwise link the opened panels, for example, with chains, to support the weight of the panels during opening.
Having to maintain a connection point between the panels presents many disadvantages such as placing limitations on the ease of repair of damaged panels and requiring higher energy consuming operators to open the door. Accordingly, there is still a continuing need for improved stacking panel overhead door designs. The present invention fulfills this need and further provides related advantages.
BRIEF SUMMARY OF THE INVENTION
The following disclosure describes a stacking panel overhead door design wherein the panels are independent of one another.
One advantage of unconnected stacking panels is the spring torque to door weight ratio is easy to control. The weight of the door decreases as the door is lifted and a panel disengages completely from its adjacent panel as it reaches the stacked position. This allows for a linear spring torque to door weight relationship requiring a smaller motor compared to existing designs to provide the lifting torque necessary to operate the door, thereby providing concomitant energy savings. Chart A represents the spring torque to door weight ratio.
A second advantage of independent stacking panels is the ease of replacement or repair of a damaged panel.
Other features and advantages of the present design will be apparent from the following more detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are included to provide a further understanding of the present invention. These drawings are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the present invention, and together with the description, serve to explain the principles of the present invention.
Chart A represents an ideal spring torque curve.
FIG. 1 is a front view of the overhead door system.
FIG. 2 is a perspective view of a panel.
FIG. 3 is an end view of a panel without the end cap.
FIG. 4 is a side view of two engaged panels without the end cap.
FIG. 5 is a front view of an end cap with the roller assemblies.
FIG. 6 is a side view of stacked door panels in the open position.
FIG. 7 is a perspective view of the drive mechanism.
Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings which illustrate by way of example the principles of the invention.
DETAILED DESCRIPTION OF THE INVENTION
As required, detailed embodiments of the present invention are disclosed; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various forms. The figures are not necessary to scale and some features may be exaggerated to show details of particular components. Therefore, specific structural and functional details disclosed are not to be interpreted as limiting but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention. Where possible, like reference numerals have been used to refer to like parts in the several alternative embodiments of the present invention described herein.
Turning now to FIG. 1 , in a preferred embodiment, the overhead door 2 comprises a plurality of unconnected panels 4 which operatively travel at each end within a first 6 and second 8 track ( FIG. 6 ).
As shown in FIGS. 2 and 3 , each panel 4 comprises an outer 10 and inner 12 surface with preferably an insulating material 14 in-between. A top 16 and bottom 18 edge each comprise a geometry that allows for engagement and disengagement of its adjacent panel during operation.
Turning to FIG. 5 , end caps 46 are fastened at each panel end. While end caps 46 in and of themselves are not required for operability, the end caps 46 provide esthetic advantages, operative engagement advantages, and fewer panel component parts. When the panels 4 are stacked, the end caps 46 contact each other, not the panels 4 , thereby limiting the bumping and disfigurement of the panels 4 . Instead of the time consuming task of separately mounting a first 26 and second 28 positioning assembly, activation engagement member 34 , and panel guide 38 (described in detail below) to each panel 30 , a prefabricated end cap 46 containing those components is fastened to each panel end 30 . The end caps 46 are preferably molded of high impact plastic.
All panels 4 , including the bottom panel 48 are interchangeable to allow for easy removal of a damaged panel and replacement. The bottom panel 48 ( FIG. 1 ) includes a removably attached weather seal and/or sensing edge 50 affixed to its bottom edge 18 that is removed and reattached to the replacement bottom panel. The end caps 46 of the bottom panel 48 are operatively engaged to a drive mechanism 64 ( FIG. 7 ), for example a cable, chain, belt, or piston.
When the drive mechanism 64 is a cable, the cable arrangement provides the cable 64 an effective operative cable geometry that will allow the cable 64 to operatively wrap on a cable drum 66 . As shown in FIG. 7 , to achieve this, in a preferred embodiment, the cable 64 is positioned vertically from the panel cable attachment 68 , around a first pulley 70 mounted to a vertical pulley bracket 78 , and then around a second pulley 72 mounted to a horizontal pulley bracket 80 and positioned about 15 inches to about 17 inches, optimally about 16 inches behind a wall attachment 82 before the cable 64 wrap on the cable drum 66 .
Turning to FIGS. 3 and 4 , for the top edge geometry a lip 20 is angled in relation to outer panel surface 10 forming angle α. Likewise, trough 22 is angled in relation to inner panel surface 12 forming angle β. For the bottom edge geometry the lip 20 is angled in relation to inner panel surface 12 forming angle α. Trough 22 is angled in relation to outer panel surface 10 forming angle β. When two panels 4 are fully engaged ( FIG. 4 ) the lip 20 of the first panel nests intimately within the trough 22 of its adjacent panel. The lip 20 /trough 22 geometry allows adjacent panels to nest and prevents engaged panels from separating, thereby insuring security, improving the wind load rating, and providing added weather protection. Preferably, a thermal break piece 24 , shown in FIG. 3 , is attached to each panel 4 . Multiple points of contact between the panel top edge thermal break piece 54 and panel bottom edge thermal break piece 56 increase the surface area of the joint to provide a more complete air infiltration seal. In the preferred embodiment, top and bottom thermal break pieces 54 , 56 are fabricated from PVC.
To insure proper panel engagement/disengagement during door closing and opening and to prevent water from traveling from the outside environment to the inside environment, angles α and β are about 10 degrees to about 25 degrees, preferably about 15 degrees to about 20 degrees and optimally about 18 degrees.
While the following elements may be attached directly to a panel 4 , for the advantages described above, in a preferred embodiment they are fabricated as part of the end cap 46 . As shown in FIG. 5 , a first 26 and second 28 positioning assembly, for example, bearing assemblies, are attached to each end 30 of panel 4 . The first positioning assembly 26 comprises a first engagement member, for example, a bearing 32 , extending outward from panel outer surface 10 to operatively engage the first track 6 . An activation engagement member, for example, an activation bearing 34 , is positioned to operatively engage the panel guide 38 of the adjacently superior panel during opening and closing of the door 2 .
Activation engagement member 34 aids in engaging/disengaging the lip 20 and trough 22 of adjacent panels by riding on the panel guide 38 around the panel bottom edge radius 40 to nest the panels in the fully engaged (door closed) position. Bearing 34 remains in contact with panel guide 38 in the stacked position, the fully closed position, and throughout the panel engagement/disengagement operation.
The second positioning assembly 28 comprises an engagement member, for example, a bearing 36 , extending inward from the panel inner surface 12 to operatively engage the second track 8 .
Although optional panel stiffeners may be added to the panel 4 , the present design does not require any stiffeners to be operatively effective, providing additional benefit over known sectional door designs which require stiffeners to achieve equivalent wind load ratings. In a preferred embodiment the insulating material 14 comprises an expandable foam injected between the outer 10 and inner 12 panel surface. While bearings have been used as exemplars for the engagement members, any low friction member, for example, PTFE pads are also contemplated.
Turning now to FIG. 6 , each set of first 6 and second 8 tracks are fixed to both sides of a door opening frame member 76 in known fashion. In a horizontal section 42 of tracks 6 , 8 , the tracks 6 , 8 are separated by a distance equal to the width of a panel 4 . In a vertical section 44 of tracks 6 , 8 , the tracks 6 , 8 are separated by a distance equal to the thickness between the first engagement member (bearing) 32 and the second engagement member (bearing) 36 . The transition between the horizontal section 42 and the vertical section 44 is accomplished through radii γ and δ. Ideally, the radii γ and δ are sized to support only two panels 4 simultaneously. The ideal spring torque curve indicated by Chart A is most closely achieved by having as few panels simultaneously engage radii γ and δ as possible. Since effective disengagement of adjacent panels will not occur if radii γ and δ are sized to only accept one panel, two panels is optimum.
The optimal sizing of the radii γ and δ allows for the advantageous reduced force required to operate the door 2 . Larger radii would require increased initial force to hold the panels, thereby causing the spring torque to door torque to become out of balance near the closed position as those panels are no longer traveling within the radii. Larger radii would also increase the height of the stacked panels 4 above the door opening creating the need for additional overhead space. In the preferred embodiment, the radii γ and δ are about three inches to about five inches, and optimally, about four inches. Along with providing the optimal spring torque to door torque ratio, the optimal radii allow the footprint of the panel stack 58 to fit within the current requirements for a typical rolling steel door construction, thereby allowing easy retrofit.
In operation of a preferred embodiment, to close the overhead door 2 a motor 60 turns a shaft 62 in a direction to unwind a cable 64 from a cable drum 66 attached to the shaft 62 . The bottom panel 48 gravity closes as the cable 64 unwinds. The bottom panel 48 maintains the panel immediately superior to it in the panel stack 58 until the point of transition to the engaged position. As the lip 20 and trough 22 of adjacent panels 4 become engaged, the process begins again as the newly engaged panel maintains its immediately superior panel in the panel stack 58 until the point of transition to the engaged position. The process repeats until all of the panels necessary to close the opening are in place.
To open the door 2 , the opposite occurs. As the motor 60 turns the shaft 62 winding the cable 64 onto the cable drum 66 the bottom panel 48 is raised thereby raising all the panels above it. As a panel 4 travels through the radii γ and δ, the activation bearings 34 located at each panel end disengage the lip 20 and trough 22 of adjacent panels as the activation bearings 34 ride on the panel guide 38 around the panel bottom edge radius 40 . As each succeeding panel is disengaged it pushes the preceding panel into and forms the panel stack 58 .
In this manner, the weight of the door 2 decreases as each panel 4 disengages and joins the panel stack 58 . This allows for easier control of the spring torque to door weight ratio. This linear relationship (indicated by Chart A) requires a much smaller motor to provide the lifting torque necessary to operate the door when compared to known technology where the panels cannot separate from one another.
Because the panels 4 are independent from and unconnected to one another, repair or replacement is easily and quickly accomplished. Returning to FIG. 6 , in the door open position each independent stacked panel 4 can be slid out the rear of the stack until the damaged panel is retrieved. Once repaired or replaced, the removed panels 4 are easily and quickly replaced within the track. No time is lost to removing hinges or otherwise disconnecting and reconnecting one panel to adjacent panels as required with existing technology.
Although the present design has been described in connection with specific examples and embodiments, those skilled in the art will recognize that the present design is capable of other variations and modifications within its scope. For example, although a cable lifting mechanism has been described, any motion that provides for raising and lowering the bottom panel is contemplated. These examples and embodiments are intended as typical of rather than in any way limiting on the scope of the present design as presented in the appended claims. | An overhead door system featuring independent, unconnected panels is described. Each panel end is operatively carried within a pair of parallel tracks. The weight of the door decreases as the door is lifted and each panel completely disengages from its adjacent panel as it reaches the stacked position. This allows for a linear spring torque to door weight relationship requiring a very small motor compared to existing designs to provide the lifting torque necessary to operate the door. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] This invention relates generally to fasteners, and in particular fasteners for connecting two metal plates. Still more particularly, the present invention relates to a locking pin having a cam that expands a lower portion of an outer shell to lock the two metal plates together.
[0003] 2. Description of the Related Art
[0004] As with other mechanical, electrical and electromechanical devices, computers are made up of many components that need to be rigidly fastened together, in order to avoid the absurdity of a loose collection of parts lying in a pile. Components such as cases and frames are typically held together with welds, rivets and other permanent fasteners. Other components, particularly internal components, are held together with nonpermanent fasteners that permit the internal components to be removed and/or replaced.
[0005] Internal components such as processor boards, or board support structures, are typically mounted on racks inside the computer. Each rack has mounting flanges with a hole in each flange, as does a frame holding the processor board. To secure the processor board to the rack, a nonpermanent fastener is placed through the aligned holes in the mounting flange of the rack and the processor board, and then the nonpermanent fastener is tightened, thus holding the two flanges together. Examples of such nonpermanent fasteners are nuts and bolts, setscrews, and clips. A problem with nuts and bolts and setscrews is that they require tools to be fastened or removed. A problem with clips is that they are prone to loosen and/or fall out, and often are unable to provide a very tight connection.
[0006] Thus, there is a need for a nonpermanent fastener that can be used without any tools, to fasten parts, and particularly computer parts, together. The fastener should be able to provide a secure, tight and strong connection that does not loosen with vibration over time. Preferably, the fastener should provide a “locked” position when securing two components together, and an “unlocked” position to remove the fastener. To avoid potential electrical shorting problems caused by the fastener being accidentally dropped onto electrical components in the computer, the nonpermanent fastener should be constructed of a material that is electrically non-conducting. The fastener should be color distinctive for both identification and location. The fastener should have a distinct marking visible to the user that indicates whether the fastener is in the locked or unlocked position. Finally, the fastener should provide a tactile and/or audible feedback indicating when the fastener is in the locked position.
SUMMARY OF THE INVENTION
[0007] As will be seen, the foregoing invention satisfies the foregoing needs and accomplishes additional objectives. Briefly described, the present invention provides a hand tightened locking pin using a unique internal cam configuration to lock the pin assembly.
[0008] The pin assembly includes a sleeve and a locking cam unit. The sleeve includes anti-rotation protrusions that match a keyhole in a first metal plate to prevent rotation of the sleeve. The pin assembly is inserted through the keyhole of the first metal plate and a circular hole in a second metal plate that lies on the first metal plate. When the locking cam unit, which is inside the sleeve, is rotated, a lower portion of the sleeve expands, locking the first and metal plates together. The cam is locked in position by concave shaped ends that mate over bulges in the lower portion of the sleeve. A locked/unlocked indicator on top of the pin assembly indicates when the concave shaped ends are mated with the bulges, thus locking the two metal plates together.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as the preferred modes of use, further objects and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
[0010] FIG. 1 depicts an interior or a computer housing;
[0011] FIG. 2 a - b illustrate lock indicators on a locking pin;
[0012] FIGS. 3 a - c depict details of a processor board rack being connected to a case mounted bracket inside the computer housing;
[0013] FIGS. 3 d - e illustrate details of a sleeve component of the locking pin;
[0014] FIGS. 4 a - b depict additional detail of the sleeve and a locking cam unit that make up the locking pin;
[0015] FIGS. 4 c - d illustrate additional detail of a rotation limiting pin and channel in the locking pin; and
[0016] FIGS. 5 a - b depict additional detail of the locking pin in an unlocked ( FIG. 5 a ) and locked ( FIG. 5 b ) position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] Referring now to the drawing figures, in which like numerals indicate like elements or steps throughout the several views, the preferred embodiment of the present invention will be described. In general, the present invention provides an improved locking pin having an internal rotatable cam that expands a sleeve, thus locking two sheets of metal when the locking pin is inserted into holes in the sheets of metal and the internal rotatable cam is turned.
[0018] With reference now to FIG. 1 , there is depicted an interior of a computer housing 102 . Attached to the inside of computer housing 102 is a case mounted bracket 106 . A processor board rack 104 , designed to hold a processor board or support card/board (none shown), has a rack flange 110 , which mates up with a bracket flange 112 of case mounted bracket 106 . A feature of the present invention, a locking pin 108 , couples rack flange 110 to bracket flange 112 , thus attaching processor board rack 104 to case mounted bracket 106 . As will be seen in further detail below, locking pin 108 includes a sleeve 116 , in which a locking cam unit 114 is seated. As depicted in FIG. 1 , locking pins 108 are in a locked position (which will be discussed in greater detail below), thus firmly coupling the processor board rack 104 to case mounted bracket 106 .
[0019] Referring now to FIG. 2 a, additional detail of locking pin 108 is provided. As shown, locking pin 108 has a first locked indicator 202 and a second locked indicator 204 . When locking pin 108 is in a locked position, about which more is described below, first locked indicator 202 and second locked indicator 204 align as shown. When locking pin 108 is in an unlocked position, by rotating locking cam unit as shown in FIG. 2 b (either clockwise as shown or counterclockwise depending on the design of locking pin 108 ), the first locked indicator 202 and second locked indicator 204 are no longer aligned. Accordingly, first locked indicator 202 and second locked indicator 204 provide a visual cue to a user indicating whether locking pin 108 is in a locked or unlocked position.
[0020] With reference now to FIG. 3 a, processor board rack 104 is shown being removed from case mounted bracket 106 when locking pins 108 are unlocked. Locking pins 108 , and in particular expandable projections 308 are able to slide out of flange circular holes 302 when locking pins 108 are unlocked (allowing expandable projections 308 to be reduced in diameter, as described in further detail below).
[0021] In FIG. 3 b, a bracket keyed hole 304 is shown in rack flange 110 . As shown, bracket keyed hole 304 is shaped to prevent a rotation of sleeve 116 , for reasons described below. After processor board rack 104 is decoupled from case mounted bracket 106 , the unlocked locking pins 108 can be slid out of rack flanges 110 as shown.
[0022] FIG. 3 c provides additional detail of locking pin 108 , an in particular sleeve 116 . As illustrated in FIG. 3 c and in a cross-sectional view in FIG. 3 d, sleeve 116 has anti-rotation protrusions 306 , which mate in keyed hole ends 310 to prevent a rotation of sleeve 116 when locking cam unit 114 is rotated to lock or unlock locking pin 108 .
[0023] FIG. 3 e provides additional detail of sleeve 116 as it is inserted or removed through bracketed keyed hole 304 of rack flange 110 . As sleeve 116 is inserted or removed from rack flange 110 , expandable projection 308 is compressed, allowing expandable projection 308 to slide through bracket keyed hole 304 .
[0024] With reference now to FIG. 3 a, when sleeve 116 is fully inserted through bracket keyed hole 304 and flange circular hole 302 , expandable projection 308 expands, thus presenting a profile that is wider than flange circular hole 302 to lock sleeve 116 in, and to press rack flange 110 against bracket flange 112 .
[0025] Referring now to FIG. 4 a, an exploded view of locking pin 108 , including locking cam unit 114 and sleeve 116 . Note that in a preferred embodiment, sleeve 116 has a retention groove 402 inset into the interior face of a castled perimeter 418 . When locking cam unit 114 is inserted into sleeve 116 , a retention lip 404 on a cam unit disc 412 seats into retention groove 402 , preventing locking cam unit 114 from coming out of sleeve 116 during normal use of locking pin 108 .
[0026] A cam opening 426 passes through the center of sleeve 116 , which affords a passageway for cam 424 and a cam stem 428 to pass through to the interior portion of expandable projection 308 .
[0027] Note that cam 424 of locking cam unit 114 has an ellipse shape 408 , as shown in FIG. 4 b. Ellipse shape 408 is so shaped to lock the locking pin 108 , as described further in FIGS. 5 a - b. Note also that ellipse shape 408 has concave ends 410 , which prevent locking pin 108 from unlocking, again as described in further detail below.
[0028] Referring to FIG. 4 c, a side view of cam unit disc 412 is depicted, to give additional detail of a rotation-limiting pin 414 . Rotation limiting pin 414 seats in a limiting channel 420 , shown in FIG. 4 d, which is inset in the mating side 422 of sleeve 116 . As shown, limiting channel 420 preferably subtends 90° of arc, thus allowing locking cam unit 114 to rotate 90° to lock or unlock locking pin 108 . Alternatively, rotation-limiting pin 414 can be attached to mating side 422 and limiting channel 420 can be inset into the underside of cam unit disc 412 .
[0029] With reference now to FIG. 5 a, locking pin 108 is illustrated in an unlocked position. As shown, in the unlocked position, cam 424 is oriented within an expandable opening 508 such that cam 424 does not press against expandable projection 308 . That is, when locking pin 108 is in the unlocked position, cam 424 does not press against a cylindrical portion 502 , a conical portion 504 , or a bullet nose 506 of expandable projection 308 . (Note that cylindrical portion 502 is preferably attached in a perpendicular orientation to a base 510 of sleeve 116 .) As such, expandable projection 308 retains a relatively narrow diameter, and does not push against an underside surface of rack flange 110 shown in FIG. 1 . Furthermore, in the non-expanded configuration, expandable projection 308 allows locking pin to be removed as described above in FIG. 3 b. Note that first locked indicator 202 and second locked indicator 204 are not aligned, thus indicating the locking pin is in the unlocked condition.
[0030] Referring now to FIG. 5 b, locking pin 108 is depicted in a locked position. In the locked position, cam 424 presses against the interior surface of expandable projection 308 , primarily against the area where cylindrical portion 502 and conical portion 504 meet. This pressure causes the diameter of expandable projection 308 to expand, causing the exterior surface of expandable projection 308 to press against the underside surface of rack flange 110 shown in FIG. 1 , thus locking together the rack flange 110 and the bracket flange 112 . Note also the alignment of first locked indicator 202 and second locked indicator 204 indicating the locked condition of locking pin 108 .
[0031] Because of the configuration and fit of cam 424 , and particularly concave end 410 , against cam retaining bulge 406 , a tactile “snap” feedback is produced with locking pin 108 locks into the locked position. This “snap” feeling transmitted to the user gives a tactile indication, which augments the visual indication afforded by first locked indicator 202 aligning with second locked indicator 204 , that locking pin 108 is locked.
[0032] In a preferred embodiment, sleeve 116 is a first distinctive color, such as (but not exclusively) yellow, and locking cam unit 114 is a second distinctive color, such as (but not exclusively) blue. This distinctive color-coding provides two advantages. First, they allow the user to quickly spot where the locking pins 108 are located. Second, by being different colors, the user can clearly confirm that the sleeve 116 is not rotating when the locking cam unit 114 is being rotated during the locking or unlocking of locking pin 108 .
[0033] The present invention has been described in relation to particular embodiments that are intended in all respects to be illustrative rather than restrictive. Alternative embodiments will become apparent to those skilled in the art to which the present invention pertains without departing from its spirit and scope. For example, although the inventive locking pin has been depicted as securing a processor board rack, the locking pin is also useful in directly securing (fastening) a board or any similar mechanical support structure. Likewise, although the present invention has been described in accordance with use in attaching components inside a computer, it will be appreciated that the locking pin may be useful in any scenario in which a tight locking mechanism is required without the use of tools. Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing discussion.
FIGURE COMPONENT LISTING 102 computer housing 104 processor board rack 106 case mounted bracket 108 locking pin 110 rack flange 112 bracket flange 114 locking cam unit 116 sleeve 202 first locked indicator 204 second locked indicator 302 flange circular hole 304 bracket keyed hole 306 anti-rotation protrusion 308 expandable projection 310 keyed hole ends 402 retention groove 404 retention lip 406 cam retaining bulge 408 ellipse shape 410 concave end 412 cam unit disc 414 rotation limiting pin 416 thumb grip 418 castled perimeter 420 limiting channel 422 mating side 424 cam 426 cam opening 428 cam stem 502 cylindrical portion 504 conical portion 506 bullet nose 508 expandable opening 510 base | A hand tightened locking pin using a unique internal cam configuration to lock the pin assembly. The pin assembly includes a sleeve and a locking cam unit. The sleeve includes anti-rotation protrusions that match a keyhole in a first metal plate to prevent rotation of the sleeve. The pin assembly is inserted through the keyhole of the first metal plate and a circular hole in a second metal plate that lies on the first metal plate. When the locking cam unit, which is inside the sleeve, is rotated, a lower portion of the sleeve expands, locking the first and metal plates together. The cam is locked in position by concave shaped ends that mate over bulges in the lower portion of the sleeve. A locked/unlocked indicator on top of the pin assembly indicates when the concave shaped ends are mated with the bulges. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED-RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
INCORPORATION BY REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
[0003] Not Applicable.
FIELD OF THE INVENTION
[0004] The invention disclosed broadly relates to the field of portable storage media, and more particularly relates to the field of protecting confidential information on portable storage media such as USB storage media.
BACKGROUND OF THE INVENTION
[0005] USB flash storage devices have become a popular way of people to share files with each other. It is common for one to give their USB storage device to someone else and ask him/her to write a file into the storage device. One may also put one or more files on their USB storage device and give the storage device to someone else so that the other person can copy the file off the storage device. Storage sizes on USB storage media has been growing at a rapid pace and it is common to have USB flash storage devices that are over a giga byte. USB hard disk storage media which are a bit larger than USB flash storage devices can also be used for similar file exchange purposes and these easily are of the order of a 100 GB. Given these large capacities one may have several files on their USB storage media.
[0006] Usually when one plugs in a USB storage device into a PC the PC has full access to all of the storage on the storage device and can read or write all of it. When person A gives his storage device to person B, he/she is vulnerable to person B reading or modifying content that person A did not intend. Even if the two people exchanging the storage devices trust each other, it is possible that the machines used in the process may be infected with malicious software and may steal information without the knowledge of the parties concerned. Malicious software may also erase contents of the USB storage device.
[0007] There are finger-print enabled USB storage media that have two partitions; an open partition that is readable/writable by all and a private partition that is completely hidden until a valid fingerprint is provided. If a valid fingerprint is provided the private partition is fully accessible.
[0008] While such a storage device can be used to address some of these issues, by keeping private information in the protected partition and shared information in the open partition. However, the size of the public partition is fixed when the storage device is initialized and cannot be changed without loss of data later. Also data stored in the public partition is vulnerable. Therefore, there is a need for a method and mechanism that overcomes the aforementioned shortcomings.
SUMMARY OF THE INVENTION
[0009] A portable storage system for connecting to a host, the portable storage system includes a storage device for storing information and a switch. The switch includes a get mode wherein the host sees only the free space in the storage device and not the part storing the information. Optionally, the portable storage system includes a give mode wherein the storage medium shows an empty space plus all shared files.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 . is a high level block diagram showing an information processing system according to the invention
[0011] FIG. 2 is a flowchart illustrating a method according to an embodiment of the invention.
[0012] FIG. 3 is a flowchart illustrating a method according to another embodiment of the invention.
DETAILED DESCRIPTION
[0013] Referring to FIG. 1 , there is shown a block diagram of a USB storage system 102 and a computer system 100 according to an embodiment of the invention. On the storage system 102 (e.g., a USB key or portable MP3 player) we have a switch 106 that can be in one of three positions—each corresponding to one of three modes: owner 108 , give 110 , and get 112 . The switch 106 is preferably in a recessed position and is hard to change unless the user uses a pencil tip or other suitable means to push it. So it is easy for the owner to see if the other party who has been given the storage system 102 tries to change the switch position. Alternatively, a dial 116 can be used to .g., last one day, last two days, last 7 days, etc. moving the dial filters the list of files shown.
[0014] A display 114 can be used to display a selected data range which is used to filter the list of files shown in the give position and among other things the state of the device.
[0015] In an alternate embodiment, the recessed switch 106 can be replaced by a set of passwords. No password corresponds to the get mode. There are two distinct passwords for give and owner modes. Each file and directory on the storage system 102 has a flag associated with it that says whether the file/directory is shared. In one embodiment, to simplify usability if a directory is shared, all the files in it are shared.
[0016] In another alternative, the switch 106 can be replaced by a fingerprint reader 117 . For example, when the user places his/her thumb on the fingerprint reader 117 this places the storage unit in the get state and placing the index finger in the reader 117 puts the storage unit in the give state. As in the case of passwords, this gives the user more control because others cannot change the switch from get to give or vise versa.
[0017] Depending on whether the owner wants to get or give files to other people he sets the switch 106 the appropriate position. The storage system 102 uses storage virtualization techniques to create file-systems of varying appropriate sizes that protect the contents on the storage device 103 by blocking access to parts of storage outside the boundaries of the file system are prevented. The storage device is described in detail below.
[0018] If the switch is set to the get position 112 and plugged into computer 100 , the storage system 102 uses storage virtualization to only show the free space on the storage device. For example, if the. USB storage device 103 has 1 GB capacity with 300 MB free, the PC 100 to which the storage device 103 is plugged into it is fooled into thinking that the USB storage system 102 is a 300 MB capacity storage device which is preferably formatted as a VFAT (virtual file allocation table) file system, though other file-systems can be used depending on the user's preferences. The PC 100 can insert files into the storage system 102 , read them back, modify them or even erase these files. It can also create directories and directory hierarchies in the storage system 102 . Assuming that the PC 100 adds files to the storage system 102 that occupy 50 MB, when the storage device 103 is unplugged from PC 100 and reinserted into another PC 2 the storage device 103 now shows up on PC 2 as if it were a 250 MB capacity storage device that is empty. The interruption of the power in between these steps is the signal to the USB storage system 102 that it must show up as an empty storage device 103 since the switch is in the “get” position 112 . So the user can get file A from PC 1 , file B from PC 2 , and file C from PC 3 . All the while each PC cannot see any of the other files the user got from earlier PCs or other files already on the storage device 103 . Any files/directories created in the get position 112 are automatically marked with the shared flag. In other embodiments any files/directories created in the get position 112 may not be automatically marked with the shared flag. The shared flag is only relevant in the “give” 112 or “owner” 108 positions as described below.
[0019] The first time the switch 106 is set to the “give” position 112 , the storage system 102 shows empty space as the only available contents. Files and directories can be created in this space. Any file/directory created in the “give” position 112 is automatically marked as shared. In the “give” position 112 only the files/directories marked “shared” are visible. When unplugged and re-plugged, the storage system 102 only shows those files that are marked shared. The PC 100 has full access to the files in the visible partition. It can read, write or erase these files. However it can make these modifications only to the files in the “give” partition 112 . If the switch is then set to the “get” position 110 the storage device shows only the free space and receives files. Files received in this manner will be visible in the “give” partition since these received files are automatically marked as shared. So if the switch is then moved to “give” position 112 from the “get” position, all recently obtained files are also available for sharing, reading (or rewriting). So a user can put all public info that he wants to share into the storage device 103 by setting it in the give position 112 and inserting the files into the storage system 102 . He can also get various files from other people and these can be given away to others.
[0020] In the owner position 108 all of the storage device 103 is visible to a user of PC 1 00 when the storage system 102 is inserted therein. Also the shared flags on files/directories are visible. The user can clear these flags either at a file level or a directory level. Clearing the shared flag on a directory recursively clears all the flags on the contents of the directory. Setting the flag on a directory only sets the flag on the directory but not its contents. Optionally there can be an operation that recursively sets the shared flag on all of its contents. Also optionally, the storage unit can include a processor, a battery, a display and user interface controls to view the directory and file structure on the storage device 103 and to change the flags for the directories and files without the need to attach the storage unit to a PC. These additional features provide extra flexibility but add cost to the system.
[0021] The storage device can also include a write-protect switch. If this is also set along with the switch in the give position the data in the file-system visible to the host PC is also write protected. The storage system 102 can include a USB connector 113 and the storage 103 can be Flash memory. Alternatively, the storage 103 can be a disk drive, flash, or molecular storage.
[0022] Referring to FIG. 2 , there is shown a flow chart illustrating an information processing method 200 usage model. When user 1 wants to get a file from User 2 , user 1 in step 202 he sets the storage device 103 in the “get” position 112 and gives the storage device 103 to User 2 . in step 204 User 2 attaches the storage system 102 to his PC 100 and sees an empty storage device 103 . In step 206 User 2 puts the file into the storage system 102 and returns the storage system 102 to User 1 . In step 208 User 1 switches the storage system 102 to owner 108 , attaches it to his PC 100 and optionally unchecks the “shared” flag on the file User 2 gave him.
[0023] Referring to FIG. 3 , there is a flow chart illustrating the usage when User 1 wants to give User 2 a file in the USB storage system 102 . In step 302 User 1 stores the file he wants to give to User 2 and puts it into the storage system 102 and sets its shared flag. If it is already on the storage device 103 , then in step 304 , User 1 sets the shared flag. In step 306 , User 1 simply moves the switch 106 to the “give” position 110 and gives User 2 the storage system 102 . In step 308 when User 2 attaches the storage device 103 to his PC 120 he sees a storage system 102 whose capacity is the sum of the size of the shared files and the free space on the storage device 103 . He can read/access the shared files and give User 1 back the storage system 102 .
[0024] In order to further facilitate simplicity of use an additional input mechanism such as dial on the storage unit can specify a date range that is used to select from the list of shared files that are visible in the partition when the switch is put to the give position. In this manner, the user can indicate that only files marked as shared in the last 3 days should be visible in the visible partition. The date range could be indicated on the unit itself or through an interface on a PC.
[0025] Therefore, while there has been described what is presently considered to be the preferred embodiment, it will understood by those skilled in the art that other modifications can be made within the spirit of the invention. | A portable storage system for connecting to a host, the portable storage system includes a storage device for storing information and a switch. The switch includes a get mode wherein the host sees only the free space in the storage device and not the part storing the information. Optionally, the portable storage system includes a give mode wherein the storage medium shows an empty space to the host and any file or directory is marked as shared and wherein the host sees a file-system whose size equals the amount of empty storage space on the storage device and an owner mode showing all of the stored information to the host and enabling the owner of the system to uncheck a shared flag on a storage device that received from another user that added files. | 6 |
[0001] This application claims priority under 35 U.S.C. § 120 as a continuation of U.S. patent application Ser. No. 09/393,126, filed Sep. 10, 1999, entitled “Baseband Wireless Network for Isochronous Communication.”
FIELD OF THE INVENTION
[0002] This invention pertains generally to network systems for exchanging data across a shared medium. More particularly, the invention is a wireless communication network system for isochronous data transfer between node devices of the network system that provides at least one master node device which manages the data transmission between slave node devices of the network system, and which further provides a time division multiple access frame definition which provides each node device on the network system a transmit time slot for communication.
THE PRIOR ART
[0003] Network systems for data communication exchange have been evolving for the past several decades. Particularly, computer network systems have been developed to exchange information and provide resource sharing. Network systems generally comprise one or more node devices which are interconnected and capable of communicating. The most common network systems today are “wired” local area networks (LANs) and wide area networks (WANs). Normally, node devices participating in such wired networks are physically connected to each other by a variety of transmission medium cabling schemes including twisted pair, coaxial cable, fiber optics and telephone systems including time division switches (T- 1 , T- 3 ), integrated services digital network (ISDN), and asymmetric digital subscriber line (ADSL). While wired solutions provide adequate bandwidth or data throughput between node devices on the network, users participating in such networks are generally restricted from mobility. Typically, users participating in a wired network are physically limited to a specific proximity by the length of the cable attached to the user's node device.
[0004] Many common network protocols in use today are asynchronous and packet based. One of the most popular is Ethernet or IEEE 802.3. These types of networks are optimized for bursts of packetized information with dynamic bandwidth requirements settled on-demand. This type of network works well for many data intensive applications in computer networks but is not ideal for situations requiring consistent delivery of time-critical data such as media streams.
[0005] Media streams typically require connection oriented real-time traffic. Most media stream applications need to establish a required level of service. Dedicated connections are required with a predictable throughput. Low traffic jitter is often a necessity and can be provided with the use of a common network clocking reference.
[0006] Fire wire, or IEEE 1394, is an emerging wireline network technology that is essentially asynchronous, but provides for isochronous transfers or “sub-actions”. Isochronous data is given priority, but consistent time intervals of data transfer is limited by mixing isochronous and purely asynchronous transfers.
[0007] Universal Serial Bus (USB) is a popular standard for computer peripheral connections. USB supports isochronous data transfer between a computer and peripheral devices. The computer serves as bus master and keeps the common clock reference. All transfers on USB must either originate or terminate at the bus master, so direct transfers between two peripheral devices is not supported.
[0008] Wireless transmission provides mobile users the ability to connect to other network devices without requiring a physical link or wire. Wireless transmission technology provides data communication through the propagation of electromagnetic waves through free space. Various frequency segments of the electromagnetic spectrum are used for such transmission including the radio spectrum, the microwave spectrum, the infrared spectrum and the visible light spectrum. Unlike wired transmission, which is guided and contained within the physical medium of a cable or line, wireless transmission is unguided, and propagates freely though air. Thus the transport medium air in wireless communication is always shared between various other wireless users. As wireless products become more pervasive, the availability of airspace for data communication becomes proportionally more limited.
[0009] Radio waves travel long distances and penetrate solid objects and are thus useful for indoor and outdoor communication. Because radio waves travel long distances, radio interference between multiple devices is a common problem, thus multiple access protocols are required among radio devices communicating using a single channel. Another common problem associated with wireless transmission is multi-path fading. Multipath fading is caused by divergence of signals in space. Some waves may be refracted off low-lying atmospheric layers or reflected off objects such as buildings and mountains, or indoors off objects such as walls and furniture and may take slightly longer to arrive than direct waves. The delayed waves may arrive out of phase with the direct waves and thus strongly attenuate or cancel the signal. As a result of multipath fading, operators have resorted to keeping a percentage of their channels idle as spares when multipath fading wipes out some frequency band temporarily.
[0010] Infrared communication is widely used for short-range communication. The remote controls used on televisions, VCRs, and stereos all use infrared communication. The major disadvantage to infrared waves is that they do not pass through solid objects, thus limiting communication between devices to “line of sight”. These drawbacks associated with the current implementation of wireless technology in network systems have resulted in mediocre performance and periodic disruption of operations.
[0011] In addition to the above noted drawbacks of Firewire and USB, there are currently no standards for wireless implementations of either. Of the wireless networks in use today, many are based at least in part on the IEEE 802.11 (wireless ethernet) extension to IEEE 802.3. Like wireless ethernet, this system is random access, using a carrier sense multiple access with collision detect (CSMA-CD) scheme for allowing multiple transmitters to use the same channel. This implementation suffers from the same drawback of wireline ethernet described above.
[0012] A similar implementation intended for industrial use is that of Hyperlan™. While still an asynchronous protocol, Hyperlan™ uses priority information to give streaming media packets higher access to the random access channel. This implementation reduces, but does not eliminate the problems of sending streaming media across asynchronous networks.
[0013] The Home-RF consortium is currently working on a proposal for a wireless network specification suitable for home networks. The current proposal specifies three types of wireless nodes, the connection points (CP), isochronous devices (1-nodes), and asynchronous devices (A-nodes). Isochronous transfers on the Home-RF network are intended for 64-kbps voice (PSTN) services and are only allowed between I-node devices and the CP device that is connected to the PSTN network. There is no allowance in the Home-RF specification for alternative methods of isochronous communication such as might be required for high quality audio or video.
[0014] The Bluetooth Special Interest Group™ has developed a standard for a short range low bit-rate wireless network. This network standard does overcome some of the shortcomings of random access networks, but still lacks some of the flexibility needed for broadband media distribution. The Bluetooth network uses a master device which keeps a common clock for the network. Each of the slave devices synchronizes their local clock to that of the master, keeping the local clock within +/−10 microseconds (/xsecs). Data transfer is performed in a Time Division Multiple Access (TDMA) format controlled by the master device. Two types of data links are supported: Synchronous Connection Oriented (SCO) and Asynchronous Connection-Less (ACL). The Master can establish a symmetric SCO link with a slave by assigning slots to that link repeating with some period Tsco. ACL links between the master and slave devices are made available by the Master addressing slave devices in turn and allowing them to respond in the next immediate slot or slots. Broadcast messages are also allowed originating only at the master with no direct response allowed from the slave devices.
[0015] Several limitations exist in the Bluetooth scheme. All communication links are established between the master device and the slave devices. There are no allowances for slave-slave communication using either point-to-point or broadcast mechanisms. Additionally, isochronous communications are only allowed using symmetric point-to-point links between the master device and one slave device. The TDMA structure used by Bluetooth is also limiting in that slot lengths are set at N*625 μsecs where N is an integer 0<=1<=5.
[0016] All of the above wireless network schemes use some form of continuous wave (CW) communications, typically frequency hopping spread spectrum. The drawbacks of these systems are that they suffer from multipath fading and use expensive components such as high-Q filters, precise local high-frequency oscillators, and power amplifiers.
[0017] Win et. al. have proposed using time-hopping spread spectrum multiple access (TH-SSMA), a version of Ultra-Wide Band (UWB), for wireless extension of Asynchronous Transfer Mode (ATM) networks which is described in the article to Win, Moe Z., et al. entitled “ATM-Based TH-SSMA Network for Multimedia PCS” published in “IEEE Journal on selected areas in communications”, Vol. 17, No. 5, May 1999. Their suggestion is to use TH-SSMA as a wireless “last hop” between a wireline ATM network and mobile devices. Each mobile device would have a unique connection to the closest base station. Each mobile-to-base connection would be supplied with a unique time hopping sequence. Transfers would happen asynchronously with each node communicating with the base at any time using a unique hopping sequence without coordinating with other mobile devices.
[0018] There are significant drawbacks to the TH-SSMA system for supporting media stream transfers between devices of the network. This method is designed to link an external switched wireline network to mobile nodes, not as a method of implementing a network of interconnected wireless nodes. This method relies on the external ATM network to control the virtual path and virtual connections between devices. Base stations must be able to handle multiple simultaneous connections with mobile devices, each with a different time hopping sequence, adding enormously to the cost and complexity of the base station. Transfers between mobile devices must travel through the base station using store and forward. Finally, all mobile nodes are asynchronous, making truly isochronous transfers impossible.
[0019] Accordingly, there is a need for a wireless communication network system apparatus which provides for isochronous data transfer between node devices of the network, which provides at least one master node device which manages the data transmission between the other node devices of the network, and which provides a means for reducing random errors induced by multipath fading, and which further provides communication protocol to provide a means for sharing the transport medium between the node devices of the network so that each node device has a designated transmit time slot for communicating data. The present invention satisfies these needs, as well as others, and generally overcomes the deficiencies found in the background art.
BRIEF DESCRIPTION OF THE INVENTION
[0020] The present invention is a wireless communication network system for isochronous data transfer between node devices. In general, the network system comprises a plurality of node devices, wherein each node device is a transceiver. Each transceiver includes a transmitter or other means for transmitting data to the other transceivers as is known in the art. Each transceiver also includes a receiver or other means for receiving data from the other transceivers as is known in the art. One of the transceivers is preferably structured and configured as a “master” device. Transceivers other than the master device are structured and configured as “slave” devices. The master device carries out the operation of managing the data transmission between the node devices of the network system. The invention further provides means for framing data transmission and means for synchronizing the network.
[0021] By way of example, and not of limitation, the data transmission framing means comprises a Medium Access Control protocol which is executed on circuitry or other appropriate hardware as is known in the art within each device on the network. The Medium Access Control protocol provides a Time Division Multiple Access (TDMA) frame definition and a framing control function. The TDMA architecture divides data transmission time into discrete data “frames”. Frames are further subdivided into “slots”. The framing control function carries out the operation of generating and maintaining the time frame information by delineating each new frame by Start-Of-Frame (SOF) symbols. These SOF symbols are used by each of the slave devices on the network to ascertain the beginning of each frame from the incoming data stream.
[0022] In the preferred embodiment, the frame definition comprises a master slot, a command slot, and a plurality of data slots. The master slot is used for controlling the frame by delineating the SOF symbols. As described in further detail below, the master slot is also used for synchronizing the network. The command slot is used for sending, requesting and authorizing commands between the master device and the slave devices of the network. The master device uses the command slot for ascertaining which slave devices are online, offline, or engaged in data transfer. The master device further uses the command slot for authorizing data transmission requests from each of the slave devices. The slave devices use the command slot for requesting data transmission and indicating its startup (online) or shutdown (offline) state. The data slots are used for data transmission between the node devices of the network. Generally, each transmitting device of the network is assigned one or more corresponding data slots within the frame in which the device may transmit data directly to another slave device without the need for a “store and forward” scheme as is presently used in the prior art. Preferably, the master dynamically assigns one or more data slots to slave devices which are requesting to transmit data. Preferably, the data slots are structured and configured to have variable bit lengths having a granularity of one bit. The present invention provides that the master device need not maintain communication hardware to provide simultaneous open links between itself and all the slave devices.
[0023] Broadcast is supported with synchronization assured. This guarantees that media can be broadcast to many nodes at the same time. This method allows, for example, synchronized audio data to be sent to several speakers at the same time, and allows left and right data to be sent in the same frame.
[0024] Asynchronous communication is allowed in certain slots of the frame through the use of either master polling or CSMA-CD after invitation from the master.
[0025] The means for synchronizing the network is preferably provided by a clock master function in the master device and a clock recovery function in the slave devices. Each node device in the network system maintains a clock running at a multiple of the bit rate of transmission. The clock master function in the master device maintains a “master clock” for the network. At least once per frame, the clock master function issues a “master sync code” that is typically a unique bit pattern which identifies the sender as the clock master. The clock recovery function in the slave devices on the network carries out the operation of recovering clock information from the incoming data stream and synchronizing the slave device to the master device using one or more correlators which identifies the master sync code and a phase or delayed locked loop mechanism. In operation, the clock master issues a “master sync code” once per frame in the “master slot”. A slave device trying to synchronize with the master clock will scan the incoming data stream for a master sync code using one or more correlators. As each master sync code is received, the phase or delayed locked loop mechanism is used to adjust the phase of the slave clock to that of the incoming data stream. By providing a common network clock on the master device, with slave devices synchronizing their local clocks to that of the master clock, support for synchronous and isochronous communication in additional to asynchronous communication is provided. Time reference between all device nodes is highly accurate eliminating most latency and timing difficulties in isochronous communication links.
[0026] As noted above, each transceiver carries out the operation of transmitting and receiving data. In wireless transmission, data is transmitted via electromagnetic waves, which are propagated through free space. In the preferred embodiment, the invention provides data transmission via baseband wireless technology. This method uses short Radio Frequency (RF) pulses to spread the power across a large frequency band and as a consequence reduces the spectral power density and the interference with any device that uses conventional narrowband communication. This method of transmitting short pulses is also referred to as Ultra Wide Band technology. This present implementation provides baseband wireless transmission without any carrier. Use of baseband wireless greatly reduces multipath fading and provides a cheaper, easier to integrate solution by eliminating a sinewave carrier. According to the invention, there is no carrier to add, no carrier to remove, and signal processing may be done in baseband frequencies.
[0027] Additionally, using short pulses provides another advantage over Continuous Wave (CW) technology in that multipath fading can be avoided or significantly reduced. The present invention further provides a modulator or other means for modulating data as is known in the art, a demodulator or other means for demodulating data as is known in the art, and a gain controller or other means for controlling the gain of each of the transceivers. In the preferred embodiment, the means for modulating data comprises a modulator which converts the TDMA frames into streams of baseband pulses. The means for demodulating data comprises a demodulator which converts incoming baseband pulses into TDMA frames.
[0028] In a first embodiment, the invention provides pulse modulation and demodulation with on/off keying. The transmitting device modulates a “1” into a pulse. A “0” is indicated as the absence or lack of a pulse. The receiver locks on to the transmitted signal to determine where to sample in the incoming pulse streams. If a pulse appears where the signal is sampled, a “1” is detected. If no pulse appears, a “0” is detected.
[0029] In another exemplary embodiment, the invention provides pulse modulation and demodulation using a pulse amplitude modulation scheme. Here, the transmitting device modulates a digital symbol as a pulse amplitude. For example, a three bit symbol can be represented with eight levels of pulse amplitude. The receiver locks on to the transmitted signal to determine where to sample the incoming pulse stream. The level of the pulse stream is sampled, and the pulse amplitude is converted to a digital symbol.
[0030] The gain controlling means carries out the operation of adjusting the output gain of the transmitter and adjusting the input gain of the receiver.
[0031] The network system also includes a hardware interface within the Data Link Layer of the Open Systems Interconnection (OSI) Reference Model comprising a multiplexer/demultiplexer unit and a plurality of slot allocation units.
[0032] The master devices described herein, in addition to carrying out its functions as a master device, may also carry out functions as a slave device as described above. For example, the master device may also engage in data transfer of non-protocol related data with a slave device.
[0033] An object of the invention is to provide a baseband wireless network system which overcomes the deficiencies in the prior art.
[0034] Another object of the invention is to provide a baseband wireless network system which provides isochronous data communication between at least two node devices on the network.
[0035] Another object of the invention is to provide a baseband wireless network system which provides a master device which manages network data communication between the other nodes devices of the network.
[0036] Another object of the invention is to provide a baseband wireless network system which provides a time division multiple access frame definition which provides each node device on the network at least one transmit time slot for data communication.
[0037] Another object of the invention is to provide a baseband wireless network system which provides a time division multiple access frame definition which provides means for sharing the data communication medium between the node devices on the network.
[0038] Another object of the invention is to provide a baseband wireless network system which provides baseband wireless data communication between the node devices of the network.
[0039] Further objects and advantages of the invention will be brought out in the following portions of the specification, wherein the detailed description is for the purpose of fully disclosing the preferred embodiment of the invention without placing limitations thereon.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0040] The present invention will be more fully understood by reference to the following drawings, which are for illustrative purposes only.
[0041] FIG. 1 is a functional block diagram showing a network system in accordance with the invention;
[0042] FIG. 2 is a functional block diagram of a transceiver node device in accordance with the invention;
[0043] FIG. 3 a is a functional block diagram of a master clock synchronization unit;
[0044] FIG. 3 b is a functional block diagram of a slave clock synchronization unit;
[0045] FIG. 4 is a time division multiple access frame definition in accordance with the present invention;
[0046] FIG. 5 is a functional block diagram of the Medium Access Control hardware interface of the present invention; and
[0047] FIG. 6 is a functional block diagram of a slot allocation unit provided in the Medium Access Control hardware.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0048] Persons of ordinary skill in the art will realize that the following description of the present invention is illustrative only and not in any way limiting. Other embodiments of the invention will readily suggest themselves to such skilled persons having the benefit of this disclosure.
[0049] Referring more specifically to the drawings, for illustrative purposes the present invention is embodied in the apparatus shown FIG. 1 through FIG. 6 . It will be appreciated that the apparatus may vary as to configuration and as to details of the parts, and that the method may vary as to details and the order of the steps, without departing from the basic concepts as disclosed herein. The invention is disclosed generally in terms of a wireless network for isochronous data communication, although numerous other uses for the invention will suggest themselves to persons of ordinary skill in the art.
[0050] Referring first to FIG. 1 , there is shown generally a wireless network system 10 in accordance with the invention. The network system 10 comprises a “master” transceiver device 12 and one or more “slave” transceiver devices 14 a through 14 n . The master device may also be referred to as a “base” transceiver, and slave devices may also be referred to as “mobile” transceivers. Master transceiver 12 and slave transceivers 14 a through 14 n include a transmitter or other means for transmitting data to the other transceivers of the network 10 via a corresponding antenna 18 , 20 a through 20 n . Transceivers 12 , 14 a through 14 n further include a receiver or other means for receiving data from the other transceivers via its corresponding antenna 18 , 20 a through 20 n . While the illustrative network 10 shows the transceiver devices 12 , 14 a through 14 n using a corresponding single shared antenna 18 , 20 a through 20 n for both transmission and reception, various arrangements known in the art may be used for providing the functions carried out by the antenna 18 , 20 a through 20 n , including for example, providing each of the transceiver devices 12 , 14 a through 14 n a first antenna for transmission and a second antenna for reception.
[0051] As described further below, the master transceiver 12 carries out the operation of managing network communication between all transceivers 12 , 14 a through 14 n of the network 10 . The master transceiver 12 includes means for managing the data transmission between the transceiver nodes of the network 10 as described further below.
[0052] Referring now to FIG. 2 as well as FIG. 1 , a functional block diagram of the “Physical layer” implementation of a transceiver node device 22 in accordance with the present invention is shown. The “Physical layer” as described herein refers to the Physical layer according to the Open Systems Interconnection (OSI) Reference Model. This model is based on a proposal developed by the International Standards Organization (ISO) to deal with connecting systems that are open for communication with other systems.
[0053] Master transceiver 12 and slave transceivers 14 a through 14 n of the network 10 are structured and configured as transceiver device 22 as described herein. The transceiver node device 22 comprises an integrated circuit or like hardware device providing the functions described below. Transceiver device 22 comprises an antenna 24 , a transmitter 26 connected to the antenna 24 , a data modulation unit 28 connected to the transmitter 26 , and an interface to Data Link Layer (DLL) 30 connected to the data modulation unit 28 . The transceiver device 22 also includes a receiver 32 connected to the antenna 24 and a data demodulation unit 34 connected to the receiver 32 and to the interface to the interface to Data Link Layer (DLL) 30 . A receive gain control unit 36 a is connected to the receiver 32 , a transmit gain control unit 36 b is connected to the transmitter 26 . A framing control unit 38 is operatively coupled to the data modulation unit 28 and the data de-modulation unit 34 . A clock synchronization unit 40 is also operatively coupled to the data modulation unit 28 and the data demodulation unit 34 .
[0054] Antenna 24 comprises a radio-frequency (RF) transducer as is known in the art and is preferably structured and configured as a receiving antenna and/or a transmitting antenna. As a receiving antenna, antenna 24 converts an electromagnetic (EM) field to an electric current, and as a transmitting antenna, converts an electric current to an EM field. In the preferred embodiment, antenna 24 is structured and configured as a ground plane antenna having an edge with a notch or cutout portion operating at a broad spectrum frequency ranging from about 2.5 gigahertz (GHz) to about 5 GHz with the center frequency at about 3.75 GHz. It will be appreciated that antenna 24 may be provided with various geometric structures in order to accommodate various frequency spectrum ranges.
[0055] Transceiver node device 22 includes hardware or circuitry which provides an interface to data link layer 30 . The interface to data link layer 30 provides an interface or communication exchange layer between the Physical layer 22 and the “higher” layers according to the OSI reference model. The layer immediately “above” the Physical layer is the data link layer. Output information which is transmitted from the data link layer to the interface 30 is communicated to the data modulation unit 28 for further data processing. Conversely, input data from the data-demodulation unit 34 is communicated to the interface 30 , which then transfers the data to the data link layer.
[0056] Transceiver node device 22 includes hardware or circuitry providing data modulation functions shown generally as data modulation unit 28 . The data modulation unit 28 carries out the operation of converting data received from the interface 30 into an output stream of pulses. In the case of pulse amplitude modulation, the amplitude of the pulse represents a value for that symbol. The number of bits represented by a pulse depends on the dynamic range and the signal to noise ratio. The simplest case comprises on-off keying, where the presence of a pulse of any amplitude represents a “1”, and the absence of a pulse represents “0”. In this case, data modulation unit 28 causes a pulse to be transmitted at the appropriate bit time to represent a “1” or no pulse to be transmitted at the appropriate time to represents a “0”. As described further below, the pulse stream produced by transceiver 22 must be synchronous with a master clock of the network 10 and must be sent at the appropriate time slot according to a frame definition defined for the network. The pulse stream is then communicated to transmitter 26 for transmission via antenna 24 .
[0057] Transceiver node device 22 includes hardware or circuitry providing means for transmitting data to other transceivers on the network shown generally as transmitter 26 . The transmitting means of transceiver 22 preferably comprises a wide band transmitter 26 . Transmitter 26 is operatively coupled to the data modulation unit 28 and to the antenna 24 . Transmitter 26 carries out the operation of transmitting the pulse stream received from modulation unit 28 and transmitting the pulse stream as electromagnetic pulses via antenna 24 . In the preferred embodiment, information is transmitted via impulses having 100 picosecond (ps) risetime and 200 ps width, which corresponds to the 2.5 through 5 GHz bandwidth.
[0058] Transceiver node device 22 includes hardware or circuitry which provides means for receiving data from other transceivers shown generally as receiver 32 . The receiving means of transmitter 22 preferably comprises a wide band receiver 32 . Receiver 32 is operatively coupled to the antenna 24 and the data demodulation unit 34 . Receiver 32 carries out the operation of detecting electromagnetic pulse signals from antenna 24 and communicating the pulse stream to the data de-modulation unit 34 . The received signal does not necessarily have the same spectrum content as the transmitted signal, and the spectrum content for received and transmitted signals vary according to the receive and transmit antenna impulse response. Typically, the received signal is shifted toward a lower frequency than the transmitted signal.
[0059] Transceiver node device 22 further includes hardware or circuitry providing means for controlling the gain of signals received and transmitted shown generally as gain control units 36 a , 36 b . The transmit gain control unit 36 b carries out the operation of controlling the power output of the transmitter 26 and receive gain control unit 36 a carries out the operation of controlling the input gain of the receiver 32 .
[0060] As indicated above, the pulse stream produced by modulator 28 must be synchronous with the master clock of the network 10 . In order to maintain a synchronized network, one device must serve the function of being a clock master and maintain the master clock for the network. Preferably, the master device 12 carries out the operation of the clock master. All other slave devices must synchronize with the master clock. The invention includes means for synchronizing the network system 10 provided by the clock synchronization unit 40 in transceiver 22 .
[0061] Referring to FIG. 3 a as well as FIG. 1 and FIG. 2 , a functional block diagram of a clock synchronization unit 40 a for the master device 12 is shown. In the master device 12 , the clock synchronization unit 40 a includes hardware or circuitry providing the functions described herein. Clock synchronization unit 40 a comprises a clock master function 42 which maintains a master clock 44 for the network 10 . The master clock 44 runs at a multiple of the bit rate. As described in further detail below, transmit time is divided into “frames”, and transceiver devices are assigned specific “slots” within each frame where the devices are permitted to transmit data. At least once per frame, the clock master function 42 issues a master sync code. The master sync code is a unique bit pattern that does not appear anywhere else in the frame which identifies the sender as the master device 12 .
[0062] Referring to FIG. 3 b as well as FIG. 1 and FIG. 2 , a functional block diagram of a clock synchronization unit 40 b for the slave devices 14 a through 14 n is shown. In the slave devices 14 a through 14 n , the clock synchronization unit 40 b includes hardware or circuitry providing the functions described herein. Clock synchronization unit 40 b comprises a local or slave clock 46 and a clock recovery function 48 . The slave clock 46 also runs at a multiple of the bit rate.
[0063] The clock recovery function 48 carries out the operation of scanning the incoming data stream received by receiver 32 to detect or otherwise ascertain the master sync code using one or more correlators. When the clock recovery function 48 detects the master sync code, the clock recovery function 48 will predict when the next master sync code will be transmitted. If the new master sync code is detected where predicted, the transceiver 22 will be considered “locked” or otherwise synchronized with the clock master 42 and will continue to monitor and verify future incoming master sync codes. If the clock recovery function 48 fails to detect a threshold number of consecutive master sync codes, lock will be considered lost. As each master sync code is received by the transceiver, a phase or delayed locked loop mechanism is used to adjust the phase of the slave clock 46 to that of the incoming pulse stream.
[0064] The clock recovery function 48 includes a master sync code correlator 50 . A slave transceiver trying to achieve synchronization or “lock” with the master clock examines the incoming data stream to detect the master sync code, as described above. The master sync code correlator 50 carries out the operation of detecting the first incoming pulse and attempting to match each of the next arriving pulses to the next predicted or pre-computed pulse. After the initial master sync code is detected, the clock recovery function 48 of the slave transceiver device will perform a coarse phase adjustment of its bit-clock to be close to that of the incoming pulse stream. When the next master sync code is expected, a mask signal is used to examine the incoming pulse train stream only where valid pulses of the incoming master sync code are expected. The primary edge of the incoming pulse is compared with the rising edge of the local clock, and any difference in phase is adjusted using a phase-locked loop mechanism. If the incoming pulse stream matches the master sync code searched for, the correlator 50 signals a successful match. If the incoming pulse stream differs from the master sync code, the process is repeated. Multiple correlators may be used to perform staggered parallel searches in order to speed up the detection of the master sync code.
[0065] The clock recovery function 48 further includes a phase lock mechanism 52 . As each predicted master sync code is detected at the slave transceivers, the phase lock mechanism 52 carries out the operation of determining the phase difference between the local slave clock 46 and the incoming pulses. The phase lock mechanism 52 adjusts the phase of the slave clock 46 so that the frequency and phase of the slave clock 46 is the same as that of the incoming pulses, thereby locking or synchronizing the local slave clock 46 to master clock 44 of the master transceiver 12 .
[0066] Referring again to FIG. 2 , as well as FIG. 1 , the transceiver node device 22 includes hardware or circuitry which provides demodulating functions and is shown generally as data demodulation unit 34 . The data demodulation unit 34 carries out the operation of converting the input pulse stream from receiver 32 into a data stream for higher protocol layers. The data de-modulation unit 34 comprises a phase offset detector 54 and a data recovery unit 56 . In an isochronous baseband wireless network, data streams will be received from different transceivers with different phase offsets. The phase offset is due to path propagation delays between the transmitter, the receiver and the master clock 44 .
[0067] As described in further detail below, a transmitter will be assigned a data “slot” within a frame to transmit to another device. The phase offset detector 54 carries out the operation of ascertaining the phase delay between the expected zero-delay pulse location, and the actual position of the incoming pulses. Typically, a known training bit pattern is transmitted before the data is transmitted. The phase offset detector 54 in the receiving device detects or otherwise ascertains the training bit pattern and determines the phase offset of the incoming pulse from the internal clock. The phase determined is then communicated to the Data Recovery Unit 56 . In the case of pulse amplitude modulation, the training sequence is also used to provide a known pulse amplitude sequence against which the modulated pulse amplitudes can be compared in the data transmission.
[0068] The Data Recovery Unit 56 in a receiving device carries out the operation of converting the incoming pulse stream data into bit data during time slots that a transmitting device is sending data to the receiving device. In the case of on-off keying modulation, the data recovery unit 56 carries out the operation of examining the pulse stream during the designated time slot or “window” for the presence or absence of a pulse. In pulse amplitude modulation, the data recovery unit 56 carries out the operation of examining the pulse stream during the designated time slot or “window” to ascertain the amplitude of the pulse signal. The “window” or time slot in which the receiving device examines pulse stream data determined by the expected location of the bit due to the encoding mechanism and the offset determined by the phase offset detector 54 . The information converted by the data de-modulation unit 34 is then communicated to the interface to data link layer 30 for further processing.
[0069] Referring now to FIG. 4 as well as FIG. 1 and FIG. 2 , a Time Division Multiple Access (TDMA) frame definition is shown and generally designated as 58 . The TDMA frame definition 58 is provided and defined by the data link protocol software of the present invention. More particularly, the TDMA frame 58 is defined by the Medium Access Control (MAC) sublayer software residing within the Data Link Layer according the OSI Reference model.
[0070] The means for managing the data transmission between the transceiver nodes of the network 10 is provided by software algorithms running and executing in the Medium Access Control. The Medium Access Control protocol provides algorithms, routines and other program means for managing and controlling access to the TDMA frame definition 58 and its associated slot components. The architecture of TDMA frame definition 58 provides for isochronous data communication between the transceivers 12 , 14 a through 14 n of the network 10 by providing a means for sharing the data transmit time that permits each transceiver of the network to transmit data during a specific time chunk or slot. The TDMA frame architecture divides data transmission time into discrete data “frames”. Frames are further subdivided into “slots”.
[0071] In the preferred embodiment, the TDMA frame definition 58 comprises a master slot 60 , a command slot 62 , and a plurality of data slots 64 a through 64 n . The master slot 60 contains a synchronizing beacon or “master sync”. More preferably, the “master sync” is the same code as the “master sync code” as described earlier for clock synchronization unit 40 . The command slot 62 contains protocol messages exchanged between the transceiver devices of the network. Generally, each of the data slots 64 a through 64 n provides data transmission time for a corresponding slave device 14 a through 14 n of the network 10 . Preferably, each data slot assigned is structured and configured to have a variable bit width and is dynamically assigned by the master device. In an alternative arrangement, the slave devices 14 a through 14 n request the use of one or more of the data slots 64 a through 64 n for data transmission. In either arrangement, the master may also be assigned one or more slots to transmit data to slave devices. If random access devices are connected to the network, these devices may be assigned a common random access time slot by the master. These devices will communicate using a CSMA-CD or similar protocol within the allocated time slot.
[0072] As noted above, the transceiver device 22 includes a framing control function 38 . The framing control function 38 carries out the operation of generating and maintaining the time frame information. In the master device 12 the framing control function 38 delineates each new frame by Start-Of-Frame (SOF) symbols. The SOF symbols are unique symbols, which do not appear anywhere else within the frame and mark the start of each frame. In the preferred embodiment, the SOF symbols serve as the “master sync” and as the “master sync code” for the network and are transmitted in the master slot 60 of frame 58 . These SOF symbols are used by the framing control function 38 in each of the slave devices 14 a through 14 n on the network to ascertain the beginning of each frame 58 from the incoming data stream. For example, in one illustrative embodiment, the invention utilizes a 10-bit SOF “master sync” code of “0111111110”.
[0073] Various encoding schemes known in the art may be used to guarantee that the SOF code will not appear anywhere else in the data sequence of the frame. For example, a common encoding scheme is 4B/5B encoding, where a 4-bit values is encoded as a 5-bit value. Several criteria or “rules” specified in a 4B/5B code table, such as “each encoded 5-bit value may contain no more than three ones or three zeros” and “each encoded 5-bit value may not end with three ones or three zeros”, ensure that a pulse stream will not have a string of six or more ones or zeros. Other techniques known in the art may also be used including, for example, bit stuffing or zero stuffing.
[0074] The master transceiver 12 carries out the operation of managing network data communication via the exchange of “protocol messages” in the command slot 62 of frame 58 . The master transceiver 12 carries out the operation of authenticating slave transceivers 14 a through 14 n , assigning and withdrawing data time slots 64 a through 64 n for the slave transceivers 14 a through 14 n , and controlling power of the slave transceivers 14 a through 14 n.
[0075] Master transceiver 12 authenticates or registers each slave transceiver by ascertaining the “state” of each of the slave transceivers of the network 10 . Each transceiver operates as a finite-state machine having at least three states: offline, online, and engaged. When a transceiver is in the offline state, the transceiver is considered “unregistered” and is not available for communication with the other devices on the network 10 . Each slave transceiver must first be “registered” with master transceiver 12 before the slave transceiver is assigned or allocated a data slot within the TDM A frame 58 . Once a transceiver is registered with the master transceiver 12 , the device is considered “online”.
[0076] A slave transceiver that is in the “online” state is ready to send data or ready to receive data from the other devices on the network 10 . Additionally, an “online” transceiver is one which is not currently transmitting or receiving “non-protocol” data. Non-protocol data is data other than that used for authenticating the “state” of the transceiver devices.
[0077] A transceiver is “engaged” when the transceiver is currently transmitting and/or receiving “non-protocol” data. Each slave device maintains and tracks its state by storing its state information internally, usually in random access memory (RAM). The state of each slave device is further maintained and tracked by the master device 12 by storing the states of the slaves in a master table (not shown) stored in RAM.
[0078] In operation, the master transceiver 12 periodically broadcasts an ALOHA packet in the command slot 62 to ascertain or otherwise detect “unregistered” slave devices and to receive command requests from the slave transceivers of then network. More generally, an ALOHA broadcast is an invitation to slave transceivers to send their pending protocol messages. This arrangement is known as “slotted ALOHA” because all protocol messages including the ALOHA broadcast are sent during a predetermined time slot. In the preferred embodiment, the ALOHA broadcast is transmitted at a predetermined interval. Responsive to this ALOHA packet and in the next immediate TDMA frame, an “unregistered” slave device 14 n transmits a signal in command slot 62 identifying itself as slave device 14 n and acknowledging the master device with a registration or “discovery” (DISC) request indicating additional information, such as the bandwidth capabilities of the device. When the registration request is received by the master transceiver 12 , the master table records in the master table that device 14 n is “online”. The master transceiver 12 also transmits a confirmation in command slot 62 to the slave device 14 n that the state of slave device 14 n has changed to “online”.
[0079] When the slave device 14 n receives the confirmation command from the master device 12 , the slave device 14 n then changes its internal state to “online”. If more than one slave transceiver replies with an acknowledgement to an ALOHA broadcast in the same frame, a packet collision may occur because both transceivers are attempting to occupy the same command slot 62 within the frame 58 . When a collision is detected in response to an ALOHA broadcast, the master transceiver 12 transmits another ALOHA message directed to a subset of the slave devices based on a binary-search style scheme, a random delay scheme or other similar searching means known in the art.
[0080] The master transceiver 12 also periodically verifies each slave transceiver device that is “online” or “engaged” according the master table to ascertain whether any failures have occurred at the slave device using a “time-out” based scheme. According to this time-out scheme, the master transceiver 12 periodically transmits a POLL packet in command slot 62 to a specific “online” slave device 14 n from the master table to ascertain the state of the slave device 14 n . In the preferred embodiment, the master transceiver 12 transmits a POLL signal every ten seconds. Responsive this POLL packet, slave device 14 n transmits an acknowledgement signal in the command slot 62 of the next immediate frame identifying itself as slave device 14 n and acknowledging its state. Responsive to this acknowledgement signal, the master transceiver 12 confirms verification of device 14 n and continues with other tasks. In the event slave device 14 n is shutdown or otherwise unavailable, master transceiver 12 will not receive a return acknowledgement and master transceiver 12 will fail to verify device 14 n . After a predetermined number failed verifications from a slave device, a time-out is triggered, and the master transceiver 12 will change the state of such slave device to “offline”.
[0081] In the command slot 62 , the flow of protocol messages between the transceivers is preferably governed by a “sequence retransmission request” (SRQ) protocol scheme. The SRQ protocol framework provides confirmation of a protocol transaction after the entire protocol sequence is completed. Effectiveness and success of the transmission of a protocol sequence are acknowledged at the completion of the entire protocol sequence rather than immediately after the transmission of each message as in the traditional Automatic Retransmission request (ARQ) approach. Because a protocol sequence may include a plurality of protocol messages, the overhead associated with acknowledging each protocol message is avoided, and bandwidth use is improved thereby. The ARQ protocol scheme is described further detail in issued U.S. Pat. No. 6,597,683, entitled “MEDIUM ACCESS CONTROL PROTOCOL FOR CENTRALIZED WIRELESS NETWORK COMMUNICATION MANAGEMENT,” filed on Sep. 10, 1999 which is expressly incorporated herein by reference.
[0082] Referring again to FIG. 3 as well as FIG. 1 and FIG. 2 , a plurality of data slots 64 a through 64 n is provided for each slave transceiver 14 a through 14 n of the network 10 which is registered as “online”. The master transceiver 12 further manages the transmission of information in slots 64 a through 64 n through traditional Time Division Multiple Access (TDMA). The command slot 62 operates in traditional TDMA mode in addition to the “slotted ALOHA” mode described above for inviting protocol messages from the slave transceivers as determined by the master transceiver 12 . The slotted ALOHA mode, which is active when the master invites a protocol message, continues until the slave protocol message is received without collision. Once the slave protocol messages is received or “captured” by the master transceiver, the command slot operates in a regular TDMA mode until the entire protocol exchange sequence between the master device and the “captured” slave device is completed. Traditional TDMA mode is used, for example, when a first slave transceiver makes a data link request to the master transceiver in order to communicate data to a second slave transceiver.
[0083] For example, a first slave transceiver 14 a (microphone) has audio data to transmit to a second slave transceiver 14 b (speaker). The master transceiver 12 manages this data transaction in the manner and sequence described herein. As indicated above, the master transceiver periodically sends an ALOHA broadcast to invite protocol messages from the slave devices of the network. Responsive to this ALOHA broadcast, slave transceiver 14 a transmits a data-link request (REQ) to master transceiver 12 identifying itself as the originating transceiver and identifying the target slave transceiver 14 b . Responsive to this REQ request, the master transceiver 12 verifies the states of originating or source transceiver 14 a and target transceiver 14 a according to the master table. If both originating transceiver and target transceiver are “online” according to the master table, the master transceiver transmits a base acknowledge (BACK) to the originating transceiver 14 a and a service request (SREQ) to the target transceiver indicating the identity of the originating transceiver 14 a and assigns a data slot to the originating transceiver 14 a within the TDMA frame 58 for data communication. If target transceiver is “offline”, the master transceiver 12 transmits a base negative acknowledge (BNACK) packet to the originating transceiver to confirm the unavailability of the target transceiver. If the target transceiver is “engaged” in communication with another device, the master transceiver 12 transmits a base busy (BBUSY) packet to the originating transceiver to indicate the unavailability of the target transceiver.
[0084] When the originating transceiver 14 a receives the BACK packet, the transceiver 14 a waits for a data-link confirmation from the master transceiver 1 , after which the transceiver 14 a begins transmitting data within a dynamically assigned data slot. Responsive to the SREQ packet from the master transceiver 12 , the target transceiver 14 b transmits a return acknowledge (ACK) to the master transceiver 12 indicating that transceiver 14 b is ready to receive data. The transceiver 14 b also begins to monitor the corresponding data slot assigned to the originating transceiver 14 a . Responsive to the return ACK from target transceiver 14 b , the master transceiver 12 transmits a data-link confirmation to originating transceiver 14 a to indicate that target transceiver is ready to receive data communication.
[0085] After originating transceiver 14 a completes its data transmission to the target transceiver 14 b , the transceiver 14 a terminates its data link by initiating a termination sequence. As indicated above, the master transceiver 12 will periodically transmit an ALOHA broadcast to find unregistered device nodes or to invite protocol requests from registered device nodes.
[0086] The termination sequence comprises communicating a terminate (TERM) process by the originating transceiver 14 a to the master transceiver 12 in response to an ALOHA message from the master transceiver 12 . In transmitting the TERM message, the originating transceiver may also identify the originating device 14 a and the target device 14 b . Responsive to this TERM message, the master transceiver 12 carries out the operation of checking the states of the originating transceiver 14 a and the target transceiver 14 b , and transmitting to transceiver 14 b a Service Termination (STERM) command.
[0087] The master transceiver verifies the state of the originating device and the target device to confirm that both devices are currently engaged for communication. If both devices are engaged, the master transceiver 12 transmits a reply BACK message to the originating transceiver to acknowledge its termination request and to indicate that the status of originating device has been changed to “online” in the master table. Additionally, master transceiver transmits a STERM message to target transceiver 14 b to indicate that originating transceiver 14 a is terminating data communication with target transceiver 14 b.
[0088] Responsive to the STERM message, the target transceiver 14 b carries out the operation of checking its internal state, terminating the reception of data, and replying with an acknowledgement (ACK). The target transceiver 14 b first checks its internal state to ensure that it is engaged in communication with originating transceiver 14 a . If target transceiver 14 b is engaged with a different transceiver, it replies with a NACK message to the master transceiver 12 to indicate target transceiver 14 b is not currently engaged with originating transceiver 14 a . If target transceiver 14 b is engaged with transceiver 14 a , then target transceiver 14 b stops receiving data from transceiver 14 a and sets its internal state to “online”. Target transceiver 14 b then transmits to master transceiver 12 an ACK message to indicate that it has terminated communication with transceiver 14 a and that it has changed it state to “online”.
[0089] When the master transceiver 12 receives the ACK message from the target transceiver 14 b , it changes the state of target transceiver 14 b in the master table to “online” and replies to target transceiver 14 b with a confirmation of the state change. The master transceiver 12 also considers the data slot which was assigned to originating transceiver 14 a as released from use and available for reallocation. When a NACK message is received by master transceiver 12 from target transceiver 14 b , a severe error is recognized by master transceiver 12 because this state was not previously registered with the master table. The master transceiver then attempts a STERM sequence with the remaining related slave devices until the proper target transceiver is discovered or otherwise ascertained.
[0090] When a user of a slave device terminates or interrupts power to the slave or otherwise makes the slave unavailable for communication, the device preferably initiates a shutdown sequence prior to such termination. The shutdown sequence comprises a shutdown (SHUT) message from the slave device 14 n to the master transceiver 12 , in response to an ALOHA broadcast from the master 12 . Responsive to the SHUT message, the master 12 replies to the slave device 14 n with a BACK message indicating that state of slave device 14 n has been changed to “offline” in the master table. Responsive to the BACK message, the slave device 14 n changes its internal state to “offline” and shuts down.
[0091] Referring now to FIG. 5 , a functional block diagram of the Medium Access Control hardware interface of the present invention is shown and generally designated as MAC 66 . In general, the MAC 66 is provided at the Data Link Layer between the Network Layer and the Physical Layer of the OSI reference model. More particularly, the MAC 66 provides the hardware circuitry within Medium Access Control (MAC) sublayer of the Data Link Layer according the OSI reference model. The Medium Access Control protocol provided by the present invention provides the software for controlling the processes of the various components of the MAC 66 as described below.
[0092] The MAC 66 comprises an integrated circuit or like hardware device providing the functions described herein. The MAC 66 provides means associated with each transceiver for connecting multiple data links received from the Logical Link Layer to a single physical TDMA link. The MAC 66 comprises a communication interface 68 for providing communication with the Medium Access Control Protocol 69 , a Physical Layer interface 70 for communication with the Physical layer, a plurality of slot allocation units (SAU) 72 a through 72 n each operatively coupled to the communication interface 68 , a Multiplexer/Demultiplexer (Mux/Demux) unit 74 operatively coupled to the Physical Layer interface 70 and each of the SAU 72 a through 72 n , and a Logical Link Control (LLC) interface 73 connected to each of the SAU 72 a through 72 n . A plurality of data interfaces 76 a through 76 n are also provided for transmitting data to and receiving data from the LLC interface 73 . Each data interface 76 a through 76 n is connected to a corresponding SAU 72 a through 72 n.
[0093] Data streams in the present invention will flow in both directions. For example, output data will be transmitted from higher level protocols through the DLL hardware 66 and out to the Physical Layer via interface 70 . Input data is received from the Physical Layer through interface 70 into the MAC 66 and then communicated to the higher level protocols. Within the MAC 66 the data path comprises the data interfaces 76 a through 76 n connected to the SAU 72 a through 2 n , the SAU 72 a through 72 n connected to the Mux/Demux 74 , and the Mux/Demux 74 connected to the Physical Layer interface 70 . The direction of data flow within each SAU 72 a through 72 n is controlled by the Medium Access Control protocol 69 via communication interface 68 . The communication interface 68 is preferably separated from the data path through MAC 66 . This arrangement provides simple data sources, such as audio streaming devices, a direct connection to the MAC 66 .
[0094] The Mux/Demux 74 carries out the operation of merging outgoing data streams from the SAU 72 a through 72 n into a single signal transmitted by the Physical Layer. In the preferred embodiment, a TDMA scheme is used for data transmission. Under the TDMA multiple access definition scheme, only one device may be transmitting at any given time. In this case, the Mux/Demux 74 is connected to the outputs of each SAU. The output of the Mux/Demux 74 is then operatively coupled to the Physical Layer interface 70 . The Mux/Demux 74 also carries out the operation of distributing incoming network data received from the Physical Layer via interface 70 into the SAU 72 a through 72 n . Generally, the currently active SAU will receive this incoming data.
[0095] Referring now to FIG. 6 as well as FIG. 5 , a block diagram of an SAU unit is shown and designated as 72 . Each SAU unit 72 a through 72 n are structured and configured as SAU 72 . SAU 72 comprises an output buffer unit 78 , an input buffer unit 80 , a control logic unit 82 connected to the output buffer unit 78 and the input buffer unit 80 , and control status registers 84 connected to the control logic unit 82 . The output buffer unit 78 stores data to be transmitted from a first device to another device in a First-In-First-Out (FIFO) buffer (not shown), encodes the buffer's output using a 4B/5B or similar encoding scheme and provides the resulting bit stream to the Mux/Demux unit 74 via line 86 a . The data to be transmitted is provided through the interface 73 via line 85 a . The input buffer unit 80 receives data from the Physical layer through the Mux/Demux unit 74 via line 86 b , decodes it according the same 4B/5B or similar encoding scheme, and stores the data in a FIFO buffer (not shown) which is connected to the data path interface 73 via line 85 b . Lines 85 a and 85 b are operatively coupled to data interfaces 76 a through 76 n for communication with interface 73 . Lines 86 a and 86 b are operatively coupled for communication with Mux/Demux unit 74 .
[0096] The control logic unit 82 comprises a state machine that controls the operation of the output buffer unit 78 and input buffer unit 80 as well as the communication between the MAC and the Logical Link Layer (LLC), and the MAC and the Physical Layer. The values of the control registers 84 are set by the LLC above the MAC layer via line 88 and control the operation of the SAU.
[0097] The control registers 84 comprise a SAU enable register 90 , a data transfer direction register 92 , a slot start time register 94 , and a slot length register 96 . The SAU enable register 90 determines whether the SAU 72 should transmit or receive data. The data transfer direction register 92 determines whether the SAU 72 is set up to transmit to the Physical Layer or to receive from the Physical Layer. The slot start time register 94 provides the SAU 72 with the time offset of the slot measured from the start of the frame, during which the SAU 72 transmits data to the Physical Layer.
[0098] The slot length register 96 determines the length of the slot. The status registers 84 provide the LLC with information about the current state of the SAU. The status registers comprise an input buffer unit empty flag, an input buffer unit full flag, an output buffer unit empty flag, an output buffer unit full flag, and an input decoder error counter. The buffer unit empty flag indicate whether the respective buffer units are empty (i.e., contain no data). The buffer unit full flag indicate whether the respective buffer units are full (i.e., cannot store additional data). The input decoder error counter indicates the number of error detected during the decoding of data arriving from the Physical Layer.
[0099] The SAU 72 transmits or receives data autonomously after being set up by the LLC. The setup consists of writing appropriate values into the data transfer direction register 92 , the slot start time register 94 , and the slot length register 96 and then enabling the SAU 72 by asserting the SAU enable register 90 . The slot start time and slot length values provided in registers 94 , 96 respectively are designated to the communicating device by the network master 12 . These values are determined by the master 12 in such a way that no two transmitters in the network transmit at the same time, a requirement of the TDMA communication scheme. During transmission, the SAU 72 will monitor the current time offset within the frame and compare it with the slot start time. When the two values are equal, the SAU 72 will provide the Physical Layer with encoded data bits from the output buffer 78 until the frame has reached the end of the time slot allocated to the SAU 72 as determined by the slot length register 96 . If the output FIFO buffer is empty during the allocated time slot, the SAU 72 will transmit special bit codes indicating to the receiver that there is no data being transmitted.
[0100] Likewise, the SAU 72 will monitor the current time offset within the frame during data reception and compare it to the slot start time register 94 . When the two values are equal, the SAU 72 will acquire data from the Physical Layer through the Mux/Demux Unit 74 , decode it and store the decoded data in the input FIFO buffer. If the decoder detects a transmission error, such as a bit code sequence not found in the 4B/5B encoding table, the data stored in the input FIFO buffer is marked as invalid and the input decoder error counter is incremented. If the decoder detects special bit codes indicating empty data, the latter are ignored and will not be stored in the input FIFO buffer.
[0101] Accordingly, it will be seen that this invention provides a wireless communication network system for isochronous data transfer between node devices of the network, which provides a master node device having means for managing the data transmission between the other node devices of the network system, which further provides means for framing data transmission and means for synchronizing the network communication protocol, thus providing a means for sharing the transport medium between the node devices of the network so that each node device has a designated transmit time slot for communicating data. Although the description above contains many specificities, these should not be construed as limiting the scope of the invention but as merely providing an illustration of the presently preferred embodiment of the invention. Thus the scope of this invention should be determined by the appended claims and their legal equivalents. | An ultra wide band communication network is provided. One embodiment ultra wide band network includes a master transceiver and a slave transceiver structured to communicate with the master transceiver using a plurality of ultra wide band pulses. The master transceiver includes a framing control unit configured to generate a plurality of TDMA frames, each of the plurality of TDMA frames having a plurality of slots, each of the plurality of slots having a start of frame slot configured to identify each of the plurality of TDMA frames to the slave transceiver. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules that allow a reader to quickly ascertain the subject matter of the disclosure contained herein. This Abstract is submitted with the explicit understanding that it will not be used to interpret or to limit the scope or the meaning of the claims. | 7 |
TECHNICAL FIELD
[0001] The present invention relates generally to an integrated toilet system for removing or preventing waste obstructions. More particularly the present invention relates to using fluid means to unblock or prevent blockages in a toilet system.
BACKGROUND
[0002] It is common for current toilet systems to become blocked by waste. Often the waste which clogs a toilet is hard and unyielding, clinging to the walls of toilet traps. This can cause toilets to overflow, and impedes their use. Many methods and apparatuses in the art have employed the use of variations of plungers. The use of plungers and other external apparatuses present a number of problems concerning sanitation and ease of use. Sanitation is a problem because after an apparatus is removed from the toilet, it has unsanitary water and waste material clinging to one or more of its surfaces. Additionally, while in use, many plungers cause splashes of contaminated water to exit toilet bowls.
[0003] For users who don't have an external apparatus conveniently located with respect to the toilet, it is sometimes inconvenient and/or embarrassing to retrieve it. Another problem presents itself for users of lesser skill or physical agility, which may find it difficult to use an external apparatus, such as, for example, a toilet plunger.
SUMMARY OF THE INVENTION
[0004] A waste fragmenting toilet apparatus with pressurized water jets is disclosed which overcomes or improves upon the problems discussed above. In general, the apparatus includes a toilet bowl, a toilet trap, a water supply, and a plurality of water jet nozzles. The water jet nozzles are located within line of sight of recurrent waste blockage zones, interior to the toilet trap and/or toilet bowl. When actuated, the water jet nozzles inject pressurized water into the waste blockage zones, which weakens and/or fragments any blockages. Subsequently, a water pressure head, vacuum, pressurized air, or other means are used to flush the weakened and/or fragmented waste out of the trap and/or toilet bowl.
[0005] Due to the integral nature of the apparatus with respect to a toilet, unsanitary water and other waste that may otherwise splash out of the toilet bowl are flushed down the toilet. Additionally, the apparatus is easy to use and requires little, if any, physical agility or skill to actuate.
[0006] In one embodiment, a waste fragmenting toilet is disclosed that includes a toilet bowl, a toilet trap, and a water supply. The toilet bowl includes a bottom which is coupled to a toilet trap. The toilet trap includes a plurality of oscillating water jet nozzles positioned along one or more walls of the toilet trap. The water supply includes one or more controllable water valves. The controllable water valves control water flow to the plurality of oscillating water jet nozzles. The plurality of oscillating water jet nozzles may inject pressurized water into the toilet trap in an oscillating arc or pattern.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] A more particular description of the invention briefly described above is made below by reference to specific embodiments. Several embodiments are depicted in drawings included with this application, in which:
[0008] FIG. 1 depicts a side view of a waste fragmenting toilet apparatus with oscillating water jet nozzles;
[0009] FIG. 2 depicts an embodiment similar to FIG. 1 , additionally including oscillating water jet nozzles in a toilet bowl;
[0010] FIG. 3 depicts an embodiment similar to FIG. 1 , including some electronic components;
[0011] FIG. 4 depicts an embodiment similar to FIG. 1 , including capacitive sensors;
[0012] FIG. 5 depicts a perspective view of a waste fragmenting toilet apparatus with buttons;
[0013] FIG. 6 depicts an embodiment similar to FIG. 1 , additionally having an enzyme reservoir;
[0014] FIG. 7 depicts an embodiment similar to FIG. 1 , additionally including infrared lights and sensors;
[0015] FIG. 8 depicts an embodiment similar to FIG. 1 , additionally including a pump;
[0016] FIG. 9 depicts an embodiment similar to FIG. 8 , additionally including a pressure regulator and valve;
[0017] FIG. 10A depict a perspective view of a manually actuated waste fragmenting toilet apparatus;
[0018] FIG. 10B depict perspective view of a manually actuated waste fragmenting toilet apparatus;
[0019] FIG. 11 depicts an embodiment similar to FIG. 1 , additionally including a water tank;
[0020] FIG. 12A depicts a perspective view of a waste fragmenting toilet apparatus with a pump inside a water tank;
[0021] and FIG. 12B depicts a side view of a waste fragmenting toilet apparatus with a pump inside a water tank; and
[0022] FIG. 13 depicts an embodiment similar to FIG. 1 , additionally including pressure sensors.
DETAILED DESCRIPTION
[0023] A detailed description of the claimed invention is provided below by example, with reference to embodiments in the appended figures. Those of skill in the art will recognize that the components of the invention as described by example in the figures below could be arranged and designed in a wide variety of different configurations. Thus, the detailed description of the embodiments in the figures is merely representative of embodiments of the invention, and is not intended to limit the scope of the invention as claimed.
[0024] In some instances, features represented by numerical values, such as dimensions, mass, quantities, and other properties that can be represented numerically, are stated as approximations. Unless otherwise stated, an approximate value means “correct to within 50% of the stated value.” Thus, a length of approximately 1 inch should be read “1 inch+/−0.5 inch.”
[0025] FIG. 1 depicts a side view of a waste fragmenting toilet apparatus with oscillating water jet nozzles 108 . Toilet apparatus 100 includes toilet bowl 102 , toilet trap 104 , and water supply 106 . Toilet bowl 102 includes a bottom which is coupled to toilet trap 104 . Toilet trap 104 includes a plurality of oscillating water jet nozzles 108 positioned along the toilet trap 104 . Water supply 106 includes one or more controllable water valves 110 that control water flow to the plurality of oscillating water jet nozzles 108 , wherein the plurality of oscillating water jet nozzles 108 inject pressurized water into toilet trap 104 in an oscillating arc or pattern. The oscillating water jets 108 may be formed of compliant orifices which oscillate due to water pressure bending and moving the compliant orifices causing an oscillating arc or pattern.
[0026] When the waste fragmenting toilet apparatus 100 is actuated, water valves 110 receive pressurized water from water supply 106 . Water valves 110 then distribute the water to oscillating water jet nozzles 108 . Subsequently, nozzles 108 may inject water in a stream in sequential directions, one direction at a time per nozzle 108 , along their respective arcs. In other words, when actuated, each nozzle 108 may inject a single beam of water into toilet trap 104 at any instant in a downstream drainage direction. Over a period of time, the angle of each nozzle 108 changes and so the direction of its corresponding beam of water changes, while the location of each nozzle 108 stays the same. Due to the oscillating movement of each nozzle 108 , it traces out the same path repeatedly over a period of time; in this way, the water injected from nozzles 108 may impact any waste present in the same locations repeatedly, rapidly eroding parts of the waste until it is sufficiently eroded to be forced down toilet trap 104 by a pressure head, siphon jet, pressure difference, and/or other means used to flush toilet apparatus 100 .
[0027] In some embodiments, the oscillating arcs of nozzles 108 include angles between 0 and 90 degrees with respect to a direction which is normal to a surface whereon a respective water jet nozzle of the plurality of oscillating water jet nozzles is positioned.
[0028] In some embodiments, nozzles 108 change the angles of their respective fluid streams simultaneously, sequentially, and/or selectively depending on location of a waste blockage.
[0029] In some embodiments, nozzles 108 inject water in an oscillating arc because each nozzle 108 includes a compliant member, integral to nozzle 108 , which vibrates at a certain frequency. The frequency at which the compliant member vibrates changes a range of motion of the oscillating arc of each nozzle 108 . The frequencies of vibration are dependent on the pressures and flow rates of the water which is injected by nozzles 108 . In another embodiment, nozzles 108 inject water in an oscillating arc enabled by integrated servo motors included in each nozzle.
[0030] In some embodiments, nozzles 108 inject pressurized water into toilet trap 104 in a circular arc, the injected water cleaning the one or more walls of toilet trap 104 while impinging on any waste blockages.
[0031] Controllable water valves 110 are controlled using any of a variety of means including a continuously rotating shaft, a valve manifold, a pressure difference, etc. In embodiments using a continuously rotating shaft to control valves 110 , the rotating shaft is driven by a motor which is connected to a power supply. When the power supply is attached, or when a power switch is closed, the shaft rotates. At specific shaft angles or over shaft angle ranges, different valves 110 are opened or closed to allow water to flow to their respective nozzles 108 . Additionally, in some embodiments, the rotating shaft is powered manually.
[0032] In some embodiments using a valve manifold to control valves 110 , the valve manifold uses solenoids which open and close valves 110 . In these embodiments, the valve manifold includes a power source to energize the solenoids and to power circuitry that switches the solenoids for different valves 110 on and off. In some further embodiments, the circuitry includes one or more processors and memory.
[0033] In some embodiments using a pressure difference to control valves 110 , when valves 110 are pressurized using water pressure from any of a variety of sources including water supply 106 , a manually actuated pressure, a mechanical pump, etc., one or more of valves 110 open or close. This may be accomplished using any of a variety of means including a diaphragm, one or more pressure sensors, pistons, etc.
[0034] In some embodiments using a diaphragm, when the diaphragm is strained it also pushes and/or pulls open valves 110 . In some embodiments using pressure sensors, the sensors, by means of a wire or wirelessly, communicate a pressure to circuitry which will open and/or close valves 110 . The pressure is communicated and utilized by any of a variety of means, including via a voltage difference, a change in current, a change in capacitance, a change in inductance, a change in resistance, a time rate of change of any of the preceding, etc. The circuitry often includes one or more power sources. In a further embodiment, a pressure sensor receives power from a power source. The sensor's output is a voltage difference which is proportional to the pressure. This output is connected to a base of a transistor, which signal is amplified and used to supply voltage to a solenoid to open valves 110 . In some embodiments using pistons, as water pressure increases or decreases, the pistons change their positions. These changes in position are used to actuate the opening and closing of valves 110 .
[0035] In one embodiment, for example, a piston is positioned inside a hollow shaft, sealing one side of the shaft from the other. The shaft is connected at one end to a body of water connected to water supply 106 and at the other end the shaft includes a compressible gas which is isolated by a closed end of the shaft. The piston separates the gas from the water, and moves in one direction toward the gas when the water pressure increases. The piston moves toward the water side of the shaft when the water pressure decreases. The piston is connected to valve 110 by means such as a wire, chain, connecting rod, etc. such that when the water pressure increases, the piston moves toward the gas and valve 110 opens. When the water pressure decreases, the piston moves toward the water and valve 110 closes.
[0036] In some embodiments using a pressure difference to control valves 110 , pressure sensors 112 are included in toilet trap 104 , which are positioned on walls of toilet trap 104 , in locations between oscillating water jet nozzles 108 . These sensors 112 are used to determine where a waste blockage is located, as a sensor on one side of the blockage will read a different pressure than that on another side of the blockage. For example, in some embodiments, valves 110 include a microcontroller which includes instructions for determining a location of a blockage based on pressure readings. The microcontroller also includes instructions for opening or closing solenoids, which then control valves 110 based upon the location of the blockage. Valves 110 also often include a power source for powering the solenoids, the pressure sensors, and the microcontroller.
[0037] In the depicted embodiment, the one or more valves 110 are placed in the same location. In some embodiments, this is done with a valve manifold. In some other embodiments, valves 110 are positioned in different locations within toilet apparatus 100 . In yet other embodiments, water supply 106 includes a number of valves 110 equivalent to a total number of oscillating water jet nozzles 108 , such that each valve 110 controls flow of water to a different water jet nozzle 108 .
[0038] In the depicted embodiment, toilet apparatus 100 includes 6 oscillating water jet nozzles 108 positioned along toilet trap 104 . Nozzles 108 are positioned at intervals to enable better coverage of all of toilet trap 104 . In some embodiments, nozzles 108 are positioned such that a waste blockage at any position within toilet trap 104 can be impinged upon by water from nozzles 108 injected in a direction which coincides with a direction of water flow when toilet apparatus 100 is flushed. This is for the purpose of increasing a pressure difference between an impinged side of the blockage and an opposite side of the blockage.
[0039] In some embodiments, water supply 106 connects directly to a potable water line with a water pressure great enough to flush waste in toilet bowl 102 and toilet trap 104 down a drain. In some other embodiments, water supply 106 connects directly to a gray water line. In such embodiments, water from the gray water line may need to be filtered sufficiently so as to not block or cause undue sediment buildup on valves 110 or nozzles 108 .
[0040] In some embodiments, the water pressure in a water line connected to water supply 106 isn't great enough on its own to flush waste in toilet bowl 102 and toilet trap 104 down the drain. In such embodiments toilet apparatus 100 includes an elevated body of water, a pressurized body of fluid, and/or a vacuum-assisted flushing system in order to help with flushing. In some embodiments, in addition to oscillating water jet nozzles 108 , toilet trap 104 includes a siphon jet which actuates upon flushing toilet apparatus 100 .
[0041] Oscillating water jet nozzles 108 inject water with a kinetic energy. In embodiments where the kinetic energy of the water is great enough to cut through materials of toilet trap 104 and/or toilet bowl 102 , a material of higher wear resistance is included in regions where the injected water strikes toilet trap 104 and/or toilet bowl 102 . In one embodiment, the material included in regions where the injected water strikes toilet trap 104 is made of silicon carbide (SiC). In another embodiment, toilet bowl 102 and toilet trap 104 are comprised of a more erosion and wear resistant ceramic material than porcelain, such as fused alumina (Al 2 O 3 ).
[0042] In some embodiments, toilet trap 104 includes a last water jet nozzle of oscillating water jet nozzles 108 which injects water in a direction toward a drain exit of toilet trap 104 . In some further embodiments, the last water jet nozzle injects water with such a high kinetic energy that the water that impinges waste and any piping connected to the drain exit of toilet trap 104 pierces any of a variety of pipe materials common to such systems that it impinges on, such as polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS), 316 stainless steel, etc. In such embodiments, the piping impinged upon includes sections or interior coverings made of high erosion and wear resistant materials, such as SiC, fused Al 2 O 3 , titanium nitride (TiN), etc. In some other further embodiments, the last water jet nozzle injects water in a circle pattern, or other pattern, in order to cut away any obstructions which are lodged at and/or near the drain exit of toilet trap 104 . Some examples of items which are commonly lodged at the drain exit include children's toys, baby wipes, feminine hygiene products, needles, cigarette butts, sanitary napkins, and elastomer items such as latex balloons or nitrile gloves.
[0043] FIG. 2 depicts an embodiment similar to FIG. 1 , additionally including oscillating water jet nozzles in a toilet bowl. Toilet apparatus 200 includes toilet bowl 202 . Toilet bowl 202 includes one or more oscillating water jet nozzles 208 positioned along one or more walls of toilet bowl 202 . Oscillating water jet nozzles 208 inject pressurized water into toilet bowl 202 in an oscillating arc. In addition to breaking up waste blockages, in some embodiments, oscillating water jet nozzles 208 inject pressurized water in an oscillating arc such that the injected water cleans the surface of toilet bowl 202 .
[0044] FIG. 3 depicts an embodiment similar to FIG. 1 , including some electronic components. Toilet apparatus 300 includes one or more processors 312 and memory 314 .
[0045] FIG. 4 depicts an embodiment similar to FIG. 1 , including capacitive sensors. Toilet apparatus 400 includes toilet trap 404 , water supply 406 , and capacitive sensors 416 positioned on and/or in walls of toilet trap 404 . Toilet trap 404 includes one or more oscillating water jet nozzles 408 . Water supply 406 includes one or more controllable water valves 410 . When a waste blockage is located in toilet trap 404 between a first set of capacitive sensors 416 , the first set of capacitive sensors 416 has a different capacitance than when no waste blockage is located between the first set. This is similarly true with a second set, a third set, etc. In this way, capacitive sensors 416 are used to determine general locations of waste blockages within toilet trap 404 . In some embodiments, for example, a change in capacitance of a set of capacitive sensors 416 is found using electronic components such as those found in a capacity meter. This information is then used to actuate one or more valves 410 via other electric circuitry, which cause certain nozzles 408 to inject water into toilet trap 404 . For example, in a further embodiment, toilet apparatus 400 includes a microcontroller which includes instructions for controlling valves 410 .
[0046] FIG. 5 depicts a perspective view of a waste fragmenting toilet apparatus with buttons. Toilet apparatus 500 includes one or more tactile control buttons 518 and a plurality of oscillating water jet nozzles (not shown) which inject pressurized water into a toilet trap (not shown). Control buttons 518 actuate the oscillating water jet nozzles when depressed. In the depicted embodiment, toilet apparatus 500 includes three control buttons 518 which each have a different function. In a further embodiment, the three buttons 518 flush toilet apparatus 500 , actuate all nozzles, and actuate each nozzle one at a time in a pattern beneficial to flushing, respectively.
[0047] FIG. 6 depicts an embodiment similar to FIG. 1 , additionally having an enzyme reservoir. Toilet apparatus 600 includes enzyme reservoir 620 , water supply 606 , and toilet trap 604 . Water supply 606 includes one or more controllable water valves 610 . Toilet trap 604 includes a plurality of oscillating water jet nozzles 608 . Enzyme reservoir 620 includes a concentrated enzyme solution which breaks down fecal and other waste matter. Enzyme reservoir 620 is coupled to valves 610 such that water from water supply 606 is mixed with the concentrated enzyme solution to form a less concentrated enzyme solution. The less concentrated enzyme solution is then injected into toilet trap 604 via nozzles 608 . This less concentrated enzyme solution then partially or completely breaks down waste in toilet trap 604 . Additionally, the less concentrated enzyme solution continues to break down waste in subsequent waste pipes such as a drain and sewer. This decreases the amount of breaking down waste from toilet apparatus 600 which is needed to be done in a septic system and/or in a reclamation plant. Since nozzles 608 inject the less concentrated enzyme solution into the toilet trap in an oscillating arc (as described previously), the enzyme solution also mixes more fully with waste in toilet trap 604 , increasing the efficiency of the enzymes' processes of breaking down waste.
[0048] FIG. 7 depicts an embodiment similar to FIG. 1 , additionally including infrared lights and sensors. Toilet apparatus 700 includes toilet trap 704 . Toilet trap 704 includes a plurality of oscillating water jet nozzles 708 , one or more infrared (IR) lights 722 (meaning infrared light emitting devices), and one or more infrared (IR) light sensors 724 positioned on one or more walls of toilet trap 704 . IR lights 722 each contain an IR light transmitter, and IR light sensors 724 each contain an IR light receiver. When an IR light 722 transmits an IR signal, a number of IR light sensors 724 do or do not receive the signal. A location of a waste blockage is determined dependent on IR signal strength, which IR light sensors 724 receive the IR signal, reflectivity of walls of trap 704 , positioning of IR lights 722 and IR light sensors 724 , and orientations of IR lights 722 and IR light sensors 724 . Based upon this determination, certain nozzles 708 actuate to break up the waste blockage.
[0049] In some embodiments, toilet trap 704 includes a number of IR lights 722 equal to a number of IR light sensors 724 . Each IR light 722 is included in an IR pair with an IR light sensor 724 . In some further embodiments, each IR pair is set to send and receive a specific IR wavelength. In some other embodiments, toilet trap 704 includes a number of IR lights 722 which isn't equal to a number of IR light sensors 724 .
[0050] FIG. 8 depicts an embodiment similar to FIG. 1 , additionally including a pump. Toilet apparatus 800 includes water supply 806 and toilet trap 804 . Toilet trap 804 includes a plurality of oscillating water jet nozzles 808 . Water supply 806 includes pump 826 and one or more controllable water valves 810 . Pump 826 includes an inlet and one or more outlets. Toilet trap 804 includes oscillating water jet nozzles 808 . Pump 826 pressurizes water between water supply 806 and nozzles 808 . Subsequently, nozzles 808 inject the pressurized water into toilet trap 804 . In some embodiments, water supply 806 has a water pressure magnitude which isn't high enough for nozzles 808 to inject water with a high enough kinetic energy to effectively break up waste blockages. It is for this reason that pump 826 increases water pressure.
[0051] FIG. 9 depicts an embodiment similar to FIG. 8 , additionally including a pressure regulator and valve. Toilet apparatus 900 includes water supply 906 , toilet trap 904 , pressure regulator 928 , pressure relief valve 930 . Toilet trap 904 includes a plurality of oscillating water jet nozzles 908 . Water supply 906 includes pump 926 and one or more controllable water valves 910 . Pump 926 includes an inlet and one or more outlets. Toilet trap 904 includes a plurality oscillating water jet nozzles 908 . As shown, pressure regulator 928 and pressure relief valve 930 communicate fluidly with one or more of the same outlets of pump 926 . Pressure regulator 928 additionally communicates fluidly with the plurality of controllable water valves 910 , while pressure relief valve 930 communicates fluidly with the inlet of pump 926 . When water pressure in one or more outputs of pump 926 reach a threshold pressure, pressure regulator 928 stops excess pressure from reaching controllable water valves 910 . Pressure relief valve 930 lowers the water pressure of the outlet of pump 926 by opening, allowing the pressurized water to flow into the inlet of pump 926 ; this continues until the water pressure is low enough at the outlet of pump 926 that pressure relief valve 930 closes.
[0052] For example, in some embodiments, the threshold pressure is 120 pounds per square inch (psi). When the pressure in the outlet of pump 926 is higher than 120 psi, pressure regulator 928 is open enough to let water at 120 psi through it, and as a result, the water pressure of water in controllable water valves 910 is 120 psi. By-pass valve 930 divers water around pump 926 when the supply water pressure is all that is needed to clear a blockage or a lower pressure option is selected by a user.
[0053] In some embodiments, pump 926 includes a pressure sensor positioned at an outlet of pump 926 . When water pressure at the outlet of pump 926 reaches a determined water pressure level, pump 926 slows down and/or shuts off. This can save power and prevent pump 926 from overly pressurizing the outlet of pump 926 , and any connecting piping.
[0054] In some embodiments, pump 926 is an electrical pump. In some other embodiments, pump 926 is manually actuated.
[0055] FIG. 10A and FIG. 10B depict perspective views of a manually actuated waste fragmenting toilet apparatus. Toilet apparatus 1000 includes a manually actuated hand pump 1026 . As shown in FIG. 10A , the depicted embodiment includes a manual pump 1026 which is easily actuated by a user using his or her hands. As shown in FIG. 10B , the depicted embodiment includes a manual foot pump 1026 which is easily actuated by a user using one or more of his or her feet. The hand and foot pump may be used to increase water pressure to the oscillating water jets in the toilet.
[0056] FIG. 11 depicts an embodiment similar to FIG. 1 , additionally including a water tank. Toilet apparatus 1100 includes water supply 1106 and toilet trap 1104 . Water supply 1106 includes water tank 1132 . Water tank 1132 fluidly communicates with water supply 1106 such that water tank 1132 stores water from water supply 1106 . Water tank 1132 may include a water pump 1108 for increasing water pressure within tank 1132 before delivery through the oscillating water jets.
[0057] FIG. 12A and FIG. 12B depict a perspective view and a side view, respectively, of a waste fragmenting toilet apparatus with a pump inside a water tank. Toilet apparatus 1200 includes water supply 1206 . Water supply 1206 includes water tank 1232 and pump 1226 . In some embodiments, as depicted in FIG. 12B , pump 1226 communicates fluidly with water tank 1232 . Water stored in water tank 1232 flows, due to a pressure difference, through pump 1226 . In another embodiment, pump 1226 fluidly communicates directly with water supply 1206 . In one embodiment, as depicted in FIG. 12A , water tank 1232 includes an orifice, inside which pump 1226 is at least partially seated, such that pump 1226 is actuated from outside water tank 1232 .
[0058] FIG. 13 depicts an embodiment similar to FIG. 1 , additionally including pressure sensors. Toilet apparatus 1300 includes toilet trap 1304 and toilet bowl 1302 . Toilet trap 1304 includes a plurality of oscillating water jet nozzles 1308 and pressure sensors 1334 positioned on one or more walls of toilet trap 1304 . Pressure sensors 1334 read different pressures around a blockage than they normally would when no blockage is present. In this way, the location of a waste blockage in toilet trap 1304 can be determined, and nozzles 1308 are actuated where the blockage is located to break it up. For example, in some embodiments, when a toilet is flushed a water level within toilet bowl 1302 increases due to a waste blockage, which doesn't allow water to leave the system. The increased water level applies a greater than normal pressure to pressure sensors 1334 and to walls of toilet trap 1304 at a toilet bowl side of the waste blockage. The water pressure at a drain side of the waste blockage will be less than normal or the same. | A waste fragmenting toilet apparatus with pressurized water jets is disclosed. The apparatus includes a toilet bowl, a toilet trap, a water supply, and a plurality of oscillating water jet nozzles. The oscillating water jet nozzles are located within line of sight of recurrent waste blockage zones, interior to the toilet trap and/or toilet bowl. When actuated, the oscillating water jet nozzles inject pressurized water into a trap area breaking up waste material as it passes through. The oscillating water jet nozzles may be used to preemptively prevent blockages and to remove existing blockages. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of our earlier provisional application U.S. Ser. No. 60/320,015, filed Mar. 18, 2003.
BACKGROUND OF INVENTION
[0002] This invention relates to the production of a synthesis gas (syngas) using an autothermal reactor (ATR) and a reforming exchanger.
[0003] Reforming of hydrocarbons is a standard process applying a plurality of generally endothermic reactions for the production of hydrogen-containing synthesis gas used for manufacturing ammonia or methanol, for example. A conventional autothermal reforming reactor (ATR) is a form of steam reformer including a catalytic gas generator bed with a specially designed burner/mixer to which preheated hydrocarbon gas, air or oxygen, and steam are supplied. Partial combustion of the hydrocarbon in the burner supplies heat necessary for the reforming reactions that occur in the catalyst bed below the burner to form a mixture of mostly steam, hydrogen, carbon monoxide (CO), carbon dioxide (CO2), and the like. Effluent from the steam reformer is then usually further converted in shift converters wherein CO and steam react to form additional hydrogen and CO2, especially for ammonia or other syntheses where hydrogen is a main desired syngas constituent.
[0004] Advantages of ATR are low capital cost and easy operation compared to a conventional catalytic steam reformer, for example. Disadvantages of commercial ATR processes are the capital costs, operating difficulties, and plot area requirements associated with the air separation unit (ASU), especially where operating personnel and plot area are limited or other factors make an ASU undesirable. Where the synthesis gas is used for ammonia production, low temperature distillation has been used to remove excess nitrogen and other impurities to obtain a 99.9% purity level.
[0005] The present invention addresses a need for producing hydrogen from an ATR without using an ASU and/or low temperature distillation, by operating the ATR with excess air, supplying the ATR process effluent to a reforming exchanger to provide heat for additional syngas production, and partially purifying the product hydrogen stream without the need for low temperature processing for nitrogen rejection. Reforming exchangers used with autothermal reformers are known, for example, from U.S. Pat. Nos. 5,011,625 and 5,122,299 to LeBlanc and 5,362,454 to Cizmer et al., all of which are hereby incorporated herein by reference in their entirety. These reforming exchangers are available commercially under the trade designation KRES or Kellogg, Brown and Root (KBR) Reforming Exchanger System.
SUMMARY OF INVENTION
[0006] The present invention uses a reforming exchanger in parallel with an autothermal reactor (ATR) in a new hydrogen plant with reduced capital costs, reduced energy requirements, greater ease of operation, and reduced NOx and CO2 emissions, or in an existing hydrogen plant where the hydrogen capacity can be increased by as much as 40-60 percent with reduced export of steam from the hydrogen plant. The resulting process has very low energy consumption.
[0007] The present invention provides in one embodiment a process for producing hydrogen. The process includes: (a) catalytically reforming a first hydrocarbon portion with steam and air in an autothermal reactor to produce a first syngas effluent at a temperature from 650° to 1050° C., desirably 650° to 1000° C.; (b) supplying the first syngas effluent to a reforming exchanger; (c) passing a second hydrocarbon portion with steam through a catalyst zone in the reforming exchanger to form a second syngas effluent; (d) discharging the second syngas effluent from the catalyst zone adjacent the inlet to form a syngas admixture with the first syngas effluent; (e) passing the admixture across the catalyst zone in indirect heat exchange therewith to cool the admixture and heat the catalyst zone; (f) collecting the cooled admixture from an outlet of the reforming exchanger; (g) shift converting the admixture to obtain a carbon dioxide-rich gas stream lean in carbon monoxide; and (h) separating the carbon-dioxide-rich gas stream to form a hydrogen-lean, mixed gas stream comprising nitrogen and carbon dioxide and a hydrogen-rich product stream.
[0008] If desired, the reforming, shift conversion and mixed gas separation can be at a process pressure from 10 to 200 bars, e.g. above 30 bars. The nitrogen and carbon dioxide removal can consist of membrane separation or pressure swing adsorption, or a like unit operation that can simultaneously remove a mixture of gases from the hydrogen at the process pressure and desirably does not require separate sequential steps for carbon dioxide and nitrogen removal. The process desirably includes compressing air to the catalytic reforming with a gas turbine drive and recovering heat from exhaust from the gas turbine. The catalyst zone can include catalyst tubes, and the process can further include: supplying the first syngas effluent to a shell-side of the reformer; supplying the second hydrocarbon portion with steam through the catalyst tubes; and discharging the second syngas effluent from the catalyst tubes adjacent the shell-side inlet to form the syngas admixture. The autothermal reformer can be operated with excess air. The hydrogen-rich gas stream from the shift conversion can have a molar ratio of hydrogen to nitrogen less than 3. The nitrogen and carbon dioxide removal is desirably free of cryogenic distillation, and the process is desirably free of air separation. The proportion of the first hydrocarbon portion relative to a total of the first and second hydrocarbon portions is desirably from 55 to 85 percent. The proportion of the first hydrocarbon portion relative to a total of the first and second hydrocarbon portions is more desireably 60 to 80 percent. The hydrogen product stream can have a purity of at least 70% up to 99.5%, desirably at least 90%, more desirably at least 95%, even more desirably at least 97%, and especially at least 98.5%, by volume. The process can include supplying the hydrogen product stream to a fuel cell for the generation of an electrical current, or to a hydrotreater, e.g. to up-grade a crude oil, or to other refinery processes.
[0009] In another embodiment, the invention provides an apparatus for preparing syngas. The apparatus includes: (a) autothermal reactor means for catalytically reforming a first hydrocarbon portion with steam and air to produce a first syngas effluent at a temperature from 650° to 1050° C.; (b) means for supplying the first syngas effluent to an inlet of a reforming exchanger; (c) means for passing a second hydrocarbon portion with steam through a catalyst zone in the reforming exchanger to form a second syngas effluent; (d) means for discharging the second syngas effluent from the catalyst zone adjacent the inlet to form a syngas admixture with the first syngas effluent; (e) means for passing the admixture across the catalyst zone in indirect heat exchange therewith to cool the admixture and heat the catalyst zone; (f) means for collecting the cooled admixture from an outlet from the reforming exchanger; (g) means for shift converting the admixture to obtain a carbon dioxide-rich gas stream lean in carbon monoxide; and (h) means for separating the carbon-dioxide-rich gas stream to form a hydrogen-lean, mixed gas stream comprising nitrogen and carbon dioxide and a hydrogen-rich product stream. The separation means of the apparatus can include a pressure swing adsorption unit or a membrane separator.
BRIEF DESCRIPTION OF DRAWINGS
[0010] [0010]FIG. 1 is a simplified schematic process flow diagram of the ATR-reforming exchanger process according to one embodiment of the invention.
DETAILED DESCRIPTION
[0011] One embodiment of a process according to the present invention has the general configuration shown in FIG. 1. Desulfurized natural gas or other hydrocarbon supplied from line 2 is mixed with process steam from line 4 and the mixture is preheated in a feed preheat exchanger 6 . The steam to carbon ratio of the mixture is desirably from 2.0 to 4.0, e.g. about 3. A first portion of the preheated steam-hydrocarbon mixture is fed via line 8 to the burner in autothermal reformer (ATR) 10 , and a second portion is supplied via line 12 to the tube-side inlet of reforming exchanger 14 . If desired, additional steam can be added via line 36 to line 8 .
[0012] Air is supplied via line 16 and mixed with steam from line 18 , and the steam-air mixture is preheated in preheater 38 , e.g. to a temperature from 200° C. to 650° C., and sent to the burner via line 20 , taking due care to maintain the flame temperature in the burner below 1500° C. The air is desirably excess air, by which is meant that the resulting molar ratio of hydrogen to nitrogen (following shift conversion) in the syngas is less than about 3 (the typical stoichiometric ratio for ammonia syngas make-up). Using air instead of oxygen or oxygen-enriched air can be economically beneficial where the nitrogen content and/or hydrogen purity of the syngas is not critical, for example, in fuel cells, in the hydrotreatment of crude oil or heavy fractions thereof, or in applications where the nitrogen is inert and the presence thereof does not significantly affect the economics of the method for the use of the syngas. Air can be used as a substitute for pure oxygen when economic or space consideration restrict the use of a conventional air separation unit (ASU), such as when an ATR/reforming exchanger is used for producing hydrogen for use on a floating production storage and offtake (FPSO) facility. If desired, the air can be supplied by a compressor that driven by a gas turbine, and heat recovered from the gas turbine exhaust, for example, to preheat process feed streams, generate process steam, or the like.
[0013] The molar ratio of steam to molecular oxygen in the air-steam mixture is desirably from about 0.8 to about 1.8, more desirably about 1 to about 1.6, and the molar ratio of oxygen to carbon in the hydrocarbon feed to the ATR can be from about 0.5 to about 0.8, desirably from about 0.6 to 0.7. The split of the hydrocarbon feed to the ATR 10 (line 8 ) relative to the total hydrocarbon feed to the ATR 10 and the reforming exchanger 14 (line 2 ), is desirably from 55 to 85 percent, more desirably from 60 to 80 percent, and particularly 65 to 75 percent to the ATR. The operating conditions and flow rates are generally optimized for maximum hydrogen production.
[0014] The syngas effluent in line 22 from the ATR 10 can be supplied to the shell-side inlet of the reforming exchanger 14 . The reformed gas from the outlet ends of the catalyst tubes 24 mixes with the ATR effluent and the mixture passes across the outside of the catalyst tubes 24 to the shell-side outlet where it is collected in line 26 . The combined syngas in line 26 is cooled in the cross exchanger 6 and waste heat boiler 28 to produce steam for export, and supplied to downstream processing that can include a shift section 30 (which can include high temperature, medium temperature and/or low temperature shift converters), heat recovery 32 , mixed gas separation 34 such as CO2 removal (pressure swing adsorption (PSA) or membrane separation, for example), and the like, all unit operations of which are well known to those skilled in the art. The separation 34 is desirably free of low temperature or cryogenic separation processes used to remove excess nitrogen in ammonia syngas production, which require a separate upstream removal system for carbon dioxide that can solidify at the low temperature needed for nitrogen removal.
[0015] The heat requirement for the reforming exchanger 14 is met by the quantity and temperature of the ATR effluent. Generally, the more feed to the reforming exchanger, the more heat required to be supplied from the ATR effluent. The temperature of the ATR effluent in line 22 should be from 650° to 1000° C. or 1050° C., and can desirably be as hot as the materials of construction of the reforming exchanger 18 will allow. If the temperature is too low, insufficient reforming will occur in the reforming exchanger 14 , whereas if the temperature is too high the metallurgical considerations become problematic. Care should also be taken to ensure that operating conditions are selected to minimize metal dusting. Operating pressure is desirably from 10 to 200 bars or more, especially at least 25 or 30 bars, and can be conveniently selected to supply the hydrogen product stream at the desired pressure, thereby avoiding the need for a hydrogen compressor.
[0016] The present invention is illustrated by way of an example. A reforming exchanger installed with an ATR as in FIG. 1 where air is used in place of oxygen for 50 MMSCFD hydrogen production has a total absorbed duty in the fired process heater of 38.94 Gcal/hr, and has the associated parameters shown in Table 1 below:
TABLE 1 ATR-Reforming Exchanger Process with Excess Air Catalyst ATR ATR Shell-side Air-steam tube inlet, feed, effluent, outlet, to ATR, Stream ID: line 12 line 8 line 22 line 26 line 20 Dry Mole Fraction H2 0.0200 0.0200 0.3578 0.4492 N2 0.0190 0.0190 0.4628 0.3561 0.7804 CH4 0.9118 0.9118 0.0013 0.0036 AR 0.0000 0.0000 0.0055 0.0042 0.9400 CO 0.0000 0.0000 0.0835 0.1026 CO2 0.0000 0.0000 0.0891 0.0843 0.0300 O2 0.0000 0.0000 0.0000 0.0000 0.2099 C2H6 0.0490 0.0490 0.0000 0.0000 C3H8 0.0002 0.0002 0.0000 0.0000 Total Flow 312.6 713.9 4154.2 5414.7 2446.2 KMOL/HR (dry) H2O 947.7 2164.0 2827.0 3380.6 728.9 KMOL/HR Total Flow 1260.3 2878.0 6981.2 8795.3 3175.1 KMOL/HR Total Flow 22288 50896 134887 156700 83990 KG/HR Pressure 25.9 25.9 22.4 22.1 24.0 (kg/cm 2 abs) Temperature 601 601 1011 747 621 (° C.)
[0017] In addition, the data in Table 1 are for an example that represents low capital cost, low energy consumption, easy operation, and reduced NOx and CO2 (56 percent less than a comparable steam reforming hydrogen plant of the same capacity) and CO2 emissions. This process is an attractive option for construction of new hydrogen production facilities where excess nitrogen is desired or can be tolerated, or can be economically removed from the sythesis gas.
[0018] As another example, a reforming exchanger is installed with an ATR as shown in FIG. 1 wherein air is used as the oxygen source, for a 50 MMSCFD hydrogen production. Typical pressures and temperatures are indicated in FIG. 1 for this example, and other associated parameters are shown in Table 2 below:
TABLE 2 ATR-Reforming Exchanger Process with Excess Air Oxidant Catalyst ATR Shell-side Air-steam tube inlet ATR feed effluent, outlet, line to ATR, Stream ID: 12 line 8 line 22 26 line 20 Dry Mole Fraction H2 0.0200 0.0200 0.4115 0.4792 N2 0.0023 0.0023 0.4020 0.3089 0.7804 CH4 0.9612 0.9612 0.0026 0.0227 AR 0.0000 0.0000 0.0048 0.0037 0.0094 CO 0.0000 0.0000 0.0803 0.0875 CO2 0.0150 0.0150 0.0987 0.0980 0.0003 O2 0.0000 0.0000 0.0000 0.0000 0.2099 C2H6 0.0013 0.0013 0.0000 0.0000 C3H8 0.0002 0.0002 0.0000 0.0000 Total Flow 371.5 754.3 4069.7 5299.5 2094.1 KMOL/HR (dry) H2O 1074.8 2182.2 2610.9 3325.1 656.2 KMOL/HR Total Flow 1446.3 2936.5 6680.5 8624.6 2750.3 KMOL/HR Total Flow 25395 51557 124039 149434 72482 KG/HR Pressure 25.5 23.6 22.8 22.5 23.6 (kg/cm 2 abs) Temperature 601 601 884 659 621 (° C.)
[0019] The data in Table 2 are also for an example that represents low capital cost, low energy consumption, easy operation, and reduced NOx and CO2 emissions. The effluent recovered from the reforming exchanger includes 47.9% H2, 30.9% N2, 8.8% CO, and 9.9% CO2. The reforming exchanger effluent undergoes shift conversion, as shown in FIG. 1, resulting in an effluent having a composition of 51.9% H2, 28.6% N2, 0.5% CO, and 16.6% CO2. Purification by PSA results in a purified product having a composition of 98.0% H2, 0.80% N2, and 1.0% CH4.
[0020] The foregoing description of the invention is illustrative and explanatory of the present invention. Various changes in the materials, apparatus, and process employed will occur to those skilled in the art. It is intended that all such variations within the scope and spirit of the appended claims be embraced thereby. | Low-energy, low-capital hydrogen production is disclosed. A reforming exchanger 14 is placed in parallel with an autothermal reformer (ATR) 10 to which are supplied a preheated steam-hydrocarbon mixture. An air-steam mixture is supplied to the burner/mixer of the ATR 10 to obtain a syngas effluent at 650°-1050° C. The effluent from the ATR is used to heat the reforming exchanger, and combined reformer effluent is shift converted and separated into a mixed gas stream and a hydrogen-rich product stream. High capital cost equipment such as steam-methane reformer and air separation plant are not required. | 8 |
CROSS REFERENCE TO RELATED APPLICATION
This is a continuation application of U.S. patent application Ser. No. 60/072,777 entitled as above which was filed on Jan. 27, 1998, for which benefit of filing date is requested.
FIELD OF THE INVENTION
The invention relates to an improved device for interstation drying of freshly printed substrates in a printing press.
BACKGROUND OF THE INVENTION
In the operation of a rotary offset press, an image is reproduced on a sheet of paper or some other print stock by a plate cylinder which carries the image, a blanket cylinder which has an ink transfer surface for receiving the inked image, and an impression cylinder which presses the paper against the blanket cylinder so that the inked image is transferred to the paper. In some applications, a protective and/or decorative coating is applied to the surface of the freshly printed sheets. The freshly printed sheets are then conveyed to a sheet delivery stacker in which the finally printed sheets are collected and stacked.
In many instances printing liquids applied at an intermediate printing station of a multi-stand printing press use water as a solvent, dilutent or vehicle. These may be applied as images, spot coatings or overall coatings prior to subsequent in-line lithographic printing. If too much water remains on the printed substrate, problems with delayed drying and image quality can occur because moisture inhibits drying of ink. The problems are exacerbated as press speed is increased.
The wet ink and coatings should be dried before the sheets are stacked or run back through the press for a second pass, to prevent smearing defects and to prevent offsetting of the ink on the unprinted side of the sheets as they are stacked. Spray powder has been applied between the freshly printed sheets which are to be stacked to improve sheet handling and to separate one delivered sheet from the next sheet to prevent offsetting while the ink and/or coating dries. One limitation of the use of spray powder is that fugitive particles of the spray powder disperse into the press room and collect on press equipment, causing electrical and mechanical breakdowns and imposing a potential health hazard for press room personnel.
DESCRIPTION OF THE PRIOR ART
Hot air convection heaters and radiant heaters have been employed to reduce the volume of spray powder applied, except for the small amount needed for sheet handling purposes. Hot air convection heaters are best suited for slow to moderate speed press runs in which the exposure time of each printed sheet to the hot air convection flow is long enough that aqueous base inks and coatings are set before the sheets reach the stacker.
For high-speed press operation, for example, at 5,000 sheets per hour or more, the exposure time of each printed sheet as it passes through the dryer station is not sufficient to obtain good drying by convection flow alone. Radiant heaters such as infra-red heat lamps provide greater drying efficiency because the short wave length infra-red energy is preferentially absorbed in the liquid inks and coatings to provide rapid evaporation. The infra-red radiant energy releases water and volatiles from the ink and/or coating. Consequently, a humid air layer clings to the printed surface of the sheet as it moves through the dryer, and will be trapped between adjacent sheets in the stack unless it is removed.
As press speed is increased, the exposure time (the length of time that printed sheet is exposed to the radiant heat) is reduced. Consequently, the output power of the radiant lamp dryers has been increased to deliver more radiant energy to the printed sheets in an effort to compensate for the reduction in exposure time.
The higher operating temperatures of the high-powered lamps cause significant heat transfer to the associated printing unit, coater and press frame equipment, accelerated wear of bearings and alterations in the viscosities of the ink and coating, as well as upsetting the water balance of aqueous coatings. The heat build-up may also cause operator discomfort and injury.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, a fast medium wave infrared dryer is provided. The dryer preferably operates at a lamp bulb temperature of about 1600°-1800°F. The lamp is mounted in a housing which has a row or rows of air passages for cooling of the lamp and housing. The cooling air is blown past the lamp onto freshly processed substrates to aid in drying. The combination of intense infrared radiation and high velocity air to scrub the surface of substrate passing under the working face of the dryer enhances drying. The housing and/or the lamp preferably includes reflectors having a highly reflecting surface which is well suited for reflecting a high percentage of infrared radiation provided by the lamp and which is relatively immune to tarnishing at high temperature. The dryer includes a control system which monitors the presence of supply air pressure electrically connected in a circuit which controls the lamp. This permits the lamp to be turned off in the event there is a failure in the supply of cooling air, in order to prevent high temperature produced by the lamp from causing damage or implicating safety concerns. The dryer unit is a streamlined compact design well suited for fitting into the small space that is provided by press manufacturers between printing stations. The dryer is mounted within an extractor shell which pulls a vacuum to draw off the air which was blown past the lamp and provided by the working surface of the dryer and extracts that air after it impacts onto the freshly printed surface of a substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of a first embodiment of the invention showing its transverse relation to the path of the incoming freshly printed substrate;
FIG. 2 is a schematic end elevation view of a preferred commercial embodiment of the first embodiment of FIG. 1 shown in relation to the path of freshly processed substrate;
FIG. 3 is a schematic top plan view of the preferred commercial embodiment of FIG. 2;
FIG. 4 is a partially cut-away side elevation of the commercial embodiment of FIG. 3;
FIG. 5 is a transverse elevational section showing the commercial embodiment on the line 5--5 of FIG. 3;
FIG. 6 is a transverse elevational section showing the commercial embodiment on the line 6--6 of FIG. 3;
FIG. 7 is a bottom view of the preferred commercial embodiment of FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
In the description that follows, the same or similar reference numerals will be used to indicate the same or similar parts. With reference to FIG. 1, there is illustrated a dryer assembly forming a first embodiment of the present invention. Dryer 10 is used to dry ink or coating on a freshly processed (printed) substrate 11 as it passes under the dryer in the direction of arrow 13. A better view of this relationship in connection with the commercial embodiment (unit) of the first embodiment of FIG. 1 is shown in FIG. 2.
The dryer 10 includes an elongated dryer housing 12, preferably formed as an aluminum extrusion. This is considered an important feature because it is readily formed to contain continuous elongated cavities or passages for air and it has excellent heat transfer capacity. Elongated housing 12 preferably defines first and second cooling air passages denominated cooling air passages 14 and 16, best seen in FIGS. 1, 5 and 6, which run the length of elongated housing 12. End plates 18 and gaskets 19 close off the open ends of cooling air passages 14 and 16 at each end of housing 12. Although twin air cooling passages are shown, they could be combined into one elongated air cooling passage or be flow interconnected. More than two elongated cooling air passages should be considered within the scope of invention.
Housing 12 has a back 15, a first side portion 17 and a second side portion 21, which are more or less shaped as three sides of a rectangular shape customary with extrusions. The elongated dryer housing can be said to have a working face 24 which in the operational orientation of the dryer as in FIGS. 1 and 2 is positioned just above the freshly printed substrate 11 passing under the dryer in the direction 13. The working face 24 is formed as a semi-cylindrical concave opening 24 bounded generally by the back 15 and side portions 17 and 21 on opposite sides of the working face and running the length of housing 12. A curved wall 25 is formed in the interior of elongated housing 12 in front of (below) back 15. Curved wall 25 partly defines air passages 14 and 16. Curved wall 25 has a curved outer surface 27 partly defining the concave opening 24. The working face can be considered to include an elongated infrared lamp 30 which is centrally positioned generally in the concave space 24 spaced below curved wall 25, preferably as shown in FIGS. 1, 5 and 6. Lamp 30 comprises a fast medium wave infrared lamp which preferably has two infrared bulbs as illustrated although the number and power is a matter of choice. The bulbs preferably operate at a temperature of about 1600°-1800° F. to provide the desired fast medium wave infrared radiation. One lamp that has been used in a unit constructed in accordance with the teachings of the present invention is manufactured by Heraeus as their 9698 436 model lamp. Heraeus model 53798 lamp has been selected for a commercial unit.
The curved outer surface 27 of curved wall 25 should be provided as a reflecting surface well suited to reflecting infrared radiation and capable of withstanding elevated temperatures in air generated by the infrared lamp 30 in close proximity to the reflecting surface. The most preferred reflective surface 29 that could be recommended for this purpose is gold as gold reflects around 98 percent of medium wave infrared radiation incident thereon. Gold does not tarnish, withstands heated air and as mentioned is an excellent reflector of infrared radiation. Gold plating has the disadvantage of increased cost.
A convenient implementation of a reflective surface has been accomplished by mounting first and second reflectors 26, 28 onto the curved outer surface 27 of curved wall 25 wherein the surface of reflectors 26 and 28 facing lamp 30 are highly polished aluminum. The Heraeus bulb used in the preferred embodiment commercial unit includes a curved reflector behind the filaments which is gold plated. Therefore a gold plated reflecting surface can be provided as part of the bulb package. Reflectors 26, 28 are provided with a row of openings 34 spaced along their length, which as will be seen, serve as exit ports for cooling air directed toward lamp 30 from air passages 14, 16. They are aligned with openings 32 into the air passages.
Referring now to FIGS. 1, 5, 6 and 7, housing 12 has two rows of spaced holes (openings) 32 running along curved wall 25 and fluidly connecting cooling air passages 14, 16 with working face 24 in front of the reflecting surface of wall 25. As seen in FIGS. 5, 6 and 7, air from passages 14, 16 within housing 12 is directed toward the bulbs for lamp 30 and passes by the lamp, cooling the lamp by picking up heat from the lamp and housing and becoming heated air in the exchange. In the commercial embodiment of FIGS. 2-7, the working face may be protected by a loosely mounted quartz lens 58 selected to pass most of the infrared radiation produced by lamp 30 on through it. The loose mounting takes account of thermal expansion. Passages 60 are provided on each side of lens 58 whereby the cooling air from openings 32, 34 escapes the working face and impinges the substrate 11. The commercial embodiment of FIG. 6 preferably also includes longitudinal side pieces 62 on each side which are fluidly connected to one of the air cooling passages 14, 16 by means of openings 64 and 66 which direct some of the air in passages 14 and 16 out onto the substrate 11 as additional high velocity air directed onto the surface of the substrate. This air picks up heat from the parts of housing 12 to raise the temperature of the air being deposited on the substrate and helps cool housing 12 as well. Heated air impacting the substrate 11 assists in drying the ink or coating by removing volatiles from it. The exact number and spacing of openings is a matter of choice and must be balanced with the incoming air supply so that there is sufficient pressure to produce high velocity air to impact the substrate. Good pressure has been provided on the sheet with an average air velocity of about 27-30 inches of water column. This may be varied depending upon press speeds, ink or coatings used and solvents, etc. The idea is to scrub the vapor being volatilized by the infrared radiation and heat so that it does not interfere with further drying and is not available to recondense on the sheet. Dryer 10 is housed within an extractor which extracts the air from the slots along the sides after it has impacted the surface of the substrate to assist drying of the ink or coating on the substrate. The air is extracted in a direction opposite the direction the drying air is moving when it contacts the substrate. Spent air is extracted from above the substrate.
In FIG. 1, air is supplied to housing 12 from supply duct 22 which is fastened to the back 15 of housing 12 over a pair of intake slots 20. Gasket 23 prevents air under pressure from escaping. In FIGS. 3 and 4, intake slots 20 are located closer to an end of the dryer and the intake shape is modified. It is attached to the housing 12 through the housing of the extractor. The area of intake slots 20 is preferably at least about twice the combined area of the holes in the housing 12 to insure a relatively high pressure air flow through the outlet holes that are present whereby the pressurized air is directed onto the substrate. This prevents slots 20 from becoming a restriction that builds up too much air pressure in the supply duct instead of pressurizing the air flow passages 14, 16.
Dryer 10 also has a control unit 36 which is connected by a connection piece 35 to housing 12 or mounted on an extractor in which housing 12 resides. Control unit 36 has cover 37 and an air pressure sensor 40 which senses air pressure from chamber 16 or chamber 14, as the case may be, which is delivered to the control unit by means of a nipple 38. Control unit 36 acts to shut down lamp 30 if no air pressure is sensed by sensor 40 from within cooling air passage 16 or 14. This is an important aspect of dryer 10 because the safe operation of the dryer depends in part in the cooling action of the air from passages 14 and 16 upon lamp 30. These lamps operate at around 5000 to 6000 watts at 480 volts in an exemplary embodiment having twin filaments about 43 inches long (1100 mm). Without good air flow, the dryer will overheat and may overheat and damage adjacent press parts. Lamp 30 is supported spaced apart from the curved outer surface of curved wall 25 by means of standoffs 39. Lamp 30 may be supported in housing 12 by a support strip 42 and mounting clamps 43 which comprise a support assembly. Power connector leads 44 are schematically shown in FIG. 1. Power supply connector 46 shown in the other Figures is connected to leads 44 to provide power for the twin bulbs of lamp 30.
The dryer 10 is preferably part of an extractor. In FIGS. 2-7 the housing 12 is mounted in an extractor housing 48. Extractor housing 48 has the air inlet 22 in FIG. 5 which delivers pressurized air through slots 20 into the respective air cooling passages 14 and 16. Air cooling passages 14, 16 are shown to be separated but could be in fluid flow connection inside housing 12 if desired to promote more uniform air pressure. Air passages 14, 16 could also be a single cooling air passage behind curved wall 25.
In the extractor 48, a relative vacuum is maintained to draw in the air which has passed through the air flow openings in housing 12 after it has impacted on the substrate to assist drying and for disposal away from the press to a remote area. The extracted air moves in the reverse direction as compared to the applied high velocity air as shown in FIG. 2. The combination of air flow and infrared radiation promotes rapid drying of the freshly printed substrate 11. Housing 48 further includes vacuum outlet 50 which is connected to a space 52 through suction openings 54 in FIG. 6. Space 52 within housing 48 leads to suction inlets 56 in the form of slots running the length of dryer housing 12 along the outside edge portions 17 and 21. Vacuum is preferably provided by the suction of a blower.
One significant advantage of the dryer 10 is that it is so compact that it can be installed between printing units of a press as well as at the delivery end of the press. The working face of dryer 10 is preferably positioned within the printing press so that the lamp is only about one and one half to about two inches from the substrate being dried. In tests using a dryer of the type described, speeds of 10,000 impressions per hour have been possible with adequate drying.
In the best mode an exemplary commercial unit includes 33 nozzles in the protective glass area and 66 nozzles outside the protective glass area wherein the nozzle diameters in both cases have a diameter of about 0.09 inches. Air exit velocity has been measured from the nozzles at about 342 feet per second at one pound per square inch exit pressure. A bulb manufactured by Heraeus has a lamp specification of 6,000 watts which operates at 480 volts. In a test of a commercial unit, a stack of sheets could be run back through the press after waiting for about 2 hours instead of the 4 hours normally allowed for curing of lithographic inks. In some cases, printing could be accomplished in a second pass right after the first pass was completed. The extractor should extract as much or more air than is being supplied by the dryer and the air is preferably filtered. The bulb is preferably tied to the operation of the press so that when the press stops the bulb is turned off and turned on again when the press is restarted.
Those skilled in the art will appreciate that various modifications to the method and apparatus of the present invention may be made without departing from the scope of invention as defined in the appended claims. | A dryer is disclosed in a compact design for interstation use on printing presses, particularly lithographic presses. High velocity air is combined with intense infrared radiation to heat, evaporate and scrub vapor from freshly printed substrates. Air under pressure is provided through passages in a housing which is passed toward and by the infrared lamp in such a way as to cool the lamp and thereafter impact the substrate being dried. A pressure sensing control prevents operation of the lamp without the cooling air. The lamp power circuit is switched off if air pressure is lost. The dryer is mounted in an extractor housing provided with a negative pressure to extract the supplied air after it impacts upon the substrate. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of application Ser. No. 10/634,123, filed Aug. 4, 2003, pending.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to the fabrication of semiconductor dice. More particularly, the present invention pertains to methods and apparatus for redistributing bond pads on semiconductor dice to more widely pitched locations to facilitate formation of semiconductor die assemblies.
[0004] 2. State of the Art
[0005] As is well known, the manufacture of semiconductor devices involves many process steps. A large number of like semiconductor devices may be fabricated on a thin wafer or other bulk substrate of semiconductive material such as silicon. Each semiconductor device comprises a chip or die of semiconductor material onto which are fabricated various electronic components such as transistors, inductors, resistors and capacitors, all operably connected to form a useful device. The wafer is then subdivided to form the discrete semiconductor devices, also known as integrated circuits (ICs). The semiconductor devices may be protectively packaged either prior to or following a singulation step, wherein the wafer is severed into individual semiconductor devices. While integrated packages may be formed of two or more chips, the integration of multiple functional circuits on single chips has also become common, leading to chips with a large number of input/output (I/O) terminals for signal transmission, power supply, ground (or bias), and testing. There has been a continuing effort in the industry to enhance the functional density of semiconductor devices while simultaneously decreasing their size. Densification in chip fabrication has many advantages, including overall reduction in cost, reduction in package volume, and enhanced electrical efficiency due to shorter signal transmission paths. Moreover, increased miniaturization has enabled the formation of complex integrated circuits on a single chip or die, such as a so-called “computer on a chip.”
[0006] In general, the circuits on a chip or die terminate in conductive bond pads arrayed on the die's active surface, typically in one or more rows about the die periphery or across a central portion of the die. These bond pads are generally formed of aluminum or an aluminum alloy and are designed to be conductively connected to terminals of a carrier substrate such as an interposer or circuit board, the pattern of terminals on which may not correspond to the locations of the corresponding bond pads on the die. In addition, the lateral bond pad-to-bond pad separation (pitch) may be too close for satisfactory direct attachment to a substrate. Thus, if the conductive connection to carrier substrate terminals is to be at least in part by wire bonding, as in a dense wafer-level chip-scale package, it is difficult to achieve the desired connection without crossing of wires, undue closeness of wires, or an overly steep bonding angle, all of which may lead to a higher frequency of shorting, such as may be induced by wire sweep. Currently proposed packages have even greater numbers of bond pads packed into smaller spaces, i.e., with finer pitch.
[0007] Where a conventional package is intended to be attached in flip-chip configuration to conductive areas of an interposer or other substrate, i.e., by direct attachment with solder bumps, a redistribution layer (RDL) is currently added to the package. A conventional wafer-level semiconductor package 10 with a single RDL 20 is depicted in Prior Art FIG. 1 . The package 10 comprises a semiconductor die 12 with an active surface 18 and a backside 28 . The package 10 includes a plurality of conductive die bond pads 14 on the active surface 18 , typically either in a peripheral arrangement or along a generally central axis. In this prior art package, a die passivation layer 16 covers the active surface 18 between the die bond pads 14 to protect and electrically insulate the active surface 18 . A conventional RDL 20 comprises a metallization layer formed on the die passivation layer 16 or on one or more additional layers 26 A, 26 B . . . 26 N of passivating material. The metallization layer is typically applied by a thin film deposition process which requires photolithography and etching to define the traces of RDL 20 therefrom. Various methods may be used for forming the under-bump metallization (UBM) 22 to which the redistribution layer (RDL) 20 is joined. Typically, a UBM 22 consists of at least an adhesion/fusion barrier layer and a wetting layer (and often an intermediate layer), in order to form a pad structure which adheres well to traces 20 and to which a solder material will be attracted, or “wet,” when heated to a molten state during formation of a solder ball or bump 24 . The package 10 may be inverted atop a substrate such as an interposer (not shown) and the solder balls or bumps 24 joined to conductive areas in the form of terminal pads thereon. In a complex high-pitch ball array package, two or three redistribution metallization layers may be used, with intervening passivation layers separating the metallization layers. As a result, multiple steps of passivation deposition, etching, metallization deposition and etching are required.
[0008] Variations and improvements of the basic redistribution metallization layer are described in the following references:
[0009] U.S. Pat. No. 5,554,940 of Hubacher describes a redistribution layer which, in addition to bump pads, also includes separate test pads which may be contacted with cantilever probe needles. Each test pad is situated near a respective bond pad so that the same (or similar) probe card apparatus and cantilever needles may be used to test the semiconductor device, either on the bond pads (for a wire-bonded device) or on the test pads (for a bumped device).
[0010] In U.S. Pat. No. 6,536,653 of Wang et al., a method for bumping and bonding semiconductor packages is disclosed.
[0011] U.S. Pat. No. 6,204,562 of Ho et al. reveals a multichip module (MCM) for flip-chip attachment. The package is formed of a plurality of wafer-level chip-scale dice, wherein the larger die uses a bump pad redistribution layer for joining the dice in a flip-chip manner.
[0012] In U.S. Pat. No. 6,197,613 of Kung et al., a first bump pad redistribution layer is connected to a second redistribution layer at a different level by a via plug passing through an applied insulating layer.
[0013] In U.S. Pat. No. 6,372,619 of Huang et al., a redistribution layer is connected to elevated bump pads by vias through an insulating layer.
[0014] U.S. Pat. No. 6,433,427 of Wu et al. teaches a wafer-level package having a redistribution layer in which the redistributed bump pads are underlain by two stress-buffer layers.
[0015] U.S. Pat. No. 6,277,669 of Kung et al. describes a method for making a pad redistribution layer on a wafer-level package, wherein the distributed bump pads are underlain by an elastomeric material.
[0016] U.S. Pat. No. 6,043,109 of Yang et al. describes a method for making a wafer-level two-die package utilizing a redistribution layer on the smaller of the dice and connecting the redistribution layer to the larger die by wire bonding.
[0017] In each of the above references, one or more redistribution layers are used, typically requiring multiple deposition and etching steps. Expensive masks and reticles are required. Under-bump metallization (UBM) will also be required at the redistributed bond pad locations, adding to the overall cost. Thus, the current methods of forming RDLs require many processing steps and are time consuming and expensive. In addition, for each change in die size, for example, die “shrinks,” a heavy capital investment will be incurred. The actual extent of production costs has not been fully delineated because conventional RDL technology is relatively new and not yet fully developed. Further, there is substantial incompatibility between terminal pad pitch of many carrier substrates, such as module boards used to fabricate multichip modules, and solder ball pitch of dice employing conventional RDL technology. For example, terminal pad pitch may be constrained to about 0.5 mm, whereas solder ball pitch may be significantly finer, for example, about 0.1 to 0.2 mm.
[0018] In the manufacture of packages using redistribution metallization, the dice are typically packaged prior to Known Good Die (KGD) testing. Thus, it is important to achieve a very high yield in order to reduce production costs. However, in the current state of the art, the yield is known to be unacceptably low.
[0019] It would be desirable to provide a chip-scale semiconductor package with increased pitch, increased yield, fewer packaging steps, and at reduced cost.
[0020] It would also be desirable to provide a chip-scale semiconductor package which may be attached to a carrier substrate either by wire bonding or by flip-chip attachment.
[0021] It would be further desirable to provide a chip-scale semiconductor package with improved redistribution of bond pads.
[0022] It would be still further desirable to provide an improved pad redistribution method useful for chip-scale flip-chip semiconductor packages having die bond pads either along the die periphery or along a central axis across the die.
BRIEF SUMMARY OF THE INVENTION
[0023] In various exemplary embodiments of the present invention, methods are presented for fabricating semiconductor dice in a configuration which may facilitate forming semiconductor die assemblies of improved reliability with greater ease and economy. More particularly, the methods of the present invention avoid the use of one or more redistribution metallization layers for connecting die bond pads to an array of conductive bumps. The invention applies not only to assemblies including one or more dice, such as chip-scale wire-bonded packages and flip-chip packages, but may also be employed in fabricating other semiconductor die packages and assemblies.
[0024] The methods of the present invention use a layer of anisotropically conductive material, also commonly termed a “z-axis film,” as an “areal redistribution pad” to which intermediate conductive bumps, balls, or other connectors may be mounted by conventional bump-forming and/or wire-bonding equipment.
[0025] An example of an anisotropically conductive material useful in the present invention is a thin polymeric film formed with a dense pattern of laterally unconnected, generally parallel, conductive transverse “columns,” i.e., pins passing through the film. The conductive columns are preferably formed of a metal or metal-containing material to which a conductive ball or bump may be readily joined and retained in place. The columns are exposed on at least one surface of the film for joining of the balls or bumps thereto. An example of one such film is a polyimide film or tape containing a dense array of conductive metal columns. The columns are sufficiently laterally separated to avoid shorting.
[0026] The anisotropic film or tape is readily adhesively attached to a die passivation layer, and conductive redistribution balls or bumps may be easily formed on and attached to the anisotropic material at any locations thereon. The conductive redistribution balls or bumps are then connected to the die bond pads by the well-developed, conventional method of wire bonding. Shorting in the x- and y-axes is avoided by the construction of the anisotropic material, and shorting in the z-direction is prevented by the die passivation layer underneath the film. The conductive redistribution balls or bumps on the semiconductor die may be electrically attached to terminal pads of another substrate such as an interposer, circuit board, die, package or wafer by wire bonding or, alternatively, by flip-chip attach using another ball or bump formed thereon at the same location. This fabrication process may be accomplished with conventional equipment commonly used in the industry. As noted above, the anisotropic material acts as an “areal redistribution pad,” to which conductive balls or bumps may be bonded at any location thereon. Thus, any requirement for conventional under-bump metallization technology is avoided.
[0027] The present invention also encompasses, in additional embodiments, semiconductor die assemblies and packages fabricated of the present invention as well as higher-level assemblies incorporating the present invention.
[0028] Other features and advantages of the present invention will become apparent to those of skill in the art through consideration of the ensuing description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0029] In the drawings, which depict exemplary embodiments of various features of the present invention:
[0030] FIG. 1 is a cross-sectional view of a segment of a chip-scale semiconductor package with a conventional redistribution layer for repositioning solder bumps to match the attachment pads of an interposer;
[0031] FIG. 2 is a flow chart showing the general acts used in forming a wire-bondable semiconductor package with redistribution conductive bumps of the invention;
[0032] FIG. 3 is a perspective view of an exemplary semiconductor wafer of the invention comprising a plurality of fabricated dice with die bond pads;
[0033] FIG. 4 is an enlarged cross-sectional edge view of a portion of an exemplary semiconductor wafer of the invention, as taken along line 4 - 4 of FIG. 3 ;
[0034] FIG. 5 is an enlarged perspective view of an exemplary anisotropically conductive (z-axis conductive) film useful in forming a semiconductor package of the invention;
[0035] FIG. 6 is a perspective view of an exemplary semiconductor wafer upon which are attached fields of anisotropically conductive material of the invention;
[0036] FIG. 7 is an enlarged cross-sectional edge view of a portion of an exemplary semiconductor wafer upon which are attached fields of anisotropically conductive material of the invention, as taken along line 7 - 7 of FIG. 6 ;
[0037] FIG. 8 is a perspective view of an exemplary semiconductor wafer upon which redistribution conductive bumps are formed on fields of anisotropically conductive material of the invention;
[0038] FIG. 9 is an enlarged cross-sectional view of a portion of an exemplary semiconductor wafer with redistribution conductive bumps formed on fields of anisotropically conductive material of the invention, as taken along line 9 - 9 of FIG. 8 ;
[0039] FIG. 10 is a perspective view of an exemplary semiconductor wafer with wire bonds connecting die bond pads to redistribution conductive bumps of the invention;
[0040] FIG. 11 is an enlarged cross-sectional view of a portion of an exemplary semiconductor wafer with wire bonds connecting die bond pads to redistribution solder bumps of the invention, taken along line 11 - 11 of FIG. 10 ;
[0041] FIG. 12 is a perspective view of an exemplary semiconductor device formed of the invention and wire bonded to a carrier substrate;
[0042] FIG. 13 is a flow chart showing the general acts of the invention used in forming a flip-chip chip-scale semiconductor package with redistribution;
[0043] FIG. 14 is a perspective view of a portion of an exemplary semiconductor wafer of the invention with wire bonds connecting die bond pads to redistribution conductive bumps, followed by formation of flip-chip bumps atop the redistribution conductive bumps;
[0044] FIG. 15 is an enlarged cross-sectional view of a portion of an exemplary semiconductor wafer of the invention with wire bonds connecting die bond pads to redistribution conductive bumps, followed by formation of flip-chip bumps atop the redistribution conductive bumps, as taken along line 15 - 15 of FIG. 14 ;
[0045] FIG. 16 is a cross-sectional view of an exemplary, singulated chip-scale semiconductor die package of the invention configured for flip-chip attachment to a carrier substrate; and
[0046] FIG. 17 is a cross-sectional view of the exemplary singulated chip-scale semiconductor die package of FIG. 16 attached by flip-chip technique to a carrier substrate and underfilled by methods of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0047] In the present invention, a redistribution of I/O contacts or terminals is achieved without forming a conventional redistribution structure having one or more redistribution layers separated by passivation layers. In the present invention, an array of conductive redistribution bumps or balls is formed on an anisotropically conductive material disposed on the package and then connected to the bond pads of the die by wire bonding. The fabrication sequence, including formation and wiring of the redistribution bumps, may be performed at the wafer level. The resulting assembly may be attached to another substrate such as an interposer, another packaged die, a wafer or a circuit board by wire bonding or, alternatively, by flip-chip bonding.
[0048] Fabrication of a wire-bondable semiconductor package of the invention may be described as performing the general acts shown in blocks in FIG. 2 . Each of the acts is illustrated in one or more of FIGS. 3 through 12 .
[0049] Turning now to FIG. 2 , the acts in forming a wire-bondable semiconductor package 70 are numbered from 80 through 92 and include the following:
[0050] In act 80 , a semiconductor wafer 40 on which is fabricated a plurality of dice 50 is provided. As used herein, the term “wafer” encompasses not only conventional silicon wafers but also other bulk substrates of semiconductive material such as gallium arsenide and indium phosphide wafers as well as silicon-on-insulator (SOI) substrates, as exemplified by silicon-on-glass (SOG) substrates and silicon-on-sapphire (SOS) substrates. Each semiconductor die 50 is fabricated with an electronic circuit in the form of an integrated circuit thereon. In an exemplary wafer of FIGS. 3 and 4 , the wafer 40 has a backside 44 and an active surface 42 containing a plurality of discrete semiconductor dice 50 , the portion of active surface 42 of each die 50 having a pattern of conductive bond pads 52 thereon connected to the integrated circuits thereof (not shown). The bond pads 52 are shown surrounded by a die passivation layer 56 to electrically insulate and environmentally protect the active surface 42 . The edges 46 of each location of a die 50 are defined by cut lines, i.e., saw or scribe lines 48 A and 48 B, respectively, parallel to the x-axis and y-axis of wafer 40 , respectively. In this example, bond pads 52 are arrayed along a central axis 54 of each die 50 . Application of the invention to a die 50 with peripherally arrayed bond pads 52 will also be discussed subsequently.
[0051] The next act 82 utilizes application of an anisotropically conductive material 60 , such as a commercially available film or tape illustrated in FIG. 5 , to die 50 . Such anisotropically conductive materials 60 are also known in the industry as z-axis tape or z-axis film and are electrically conductive in only one direction, i.e., parallel to the z-axis or vertical axis, perpendicular to the plane of the film or tape. As shown, one type of anisotropically conductive material 60 may comprise a film or tape of insulative polymer 76 of a height or thickness 72 , into which a relatively dense pattern of parallel conductive metal elements 74 is embedded, generally passing through the film or tape from an upper surface 75 to a backside 77 thereof. The insulative polymer 76 is typically a dielectric material such as polyimide or other polymer. The conductive metal elements 74 may be columns formed of, for example, a metal such as tungsten, aluminum, copper, silver, gold, or alloys thereof and exposed at their upper ends 81 , i.e. on the upper surface 75 of the anisotropically conductive material 60 , so that conductive bumps or balls may be bonded to the columns. It is currently preferred that the columns 74 be formed of gold. The column diameter 79 may vary but, for example, may be between about 1 μm and about 15 μm. It is currently more preferred that the column diameter 79 be between about 2 μm and about 8 μm. The column diameter 79 and spacing or pitch 73 are preferably imposed so that a plurality of exposed columns 74 will be bonded to a single conductive bump or ball formed or placed thereon. In FIG. 5 , the diameter 59 of the footprint of an exemplary conductive bump is shown in broken lines as at least partially contacting a dozen or more columns 74 . The exposed column upperends 81 may occupy only a small portion of the upper tape surface 75 and still effectively retain the conductive bumps or balls by metallurgical bonding thereto. The anisotropically conductive material 60 is shown in FIG. 5 with an adhesive layer 78 , such as a pressure-sensitive adhesive layer on the backside 77 , for adhesion to a die passivation layer 56 (see FIG. 7 ).
[0052] As depicted in FIGS. 6 and 7 , the anisotropically conductive material 60 is applied in act 82 to the die passivation layer 56 between rows of bond pads 52 . In the wafer stage, a single elongate strip of a film or tape of anisotropically conductive material 60 may be applied over adjacent portions of two rows of dice 50 and later cut with the underlying wafer 40 when the semiconductor dice 50 are singulated. In the event that the anisotropically conductive material of the film does not have an integral adhesive layer 78 , a separately applied adhesive material may be utilized to secure the film to the dice or, alternatively, the insulative polymer may comprise a thermoplastic resin and the film of anisotropically conductive material 60 adhered to semiconductor dice 50 by a brief application of heat.
[0053] In the next act 84 , as shown in FIGS. 8 and 9 , redistribution conductive balls or bumps 58 are placed on the anisotropically conductive material 60 and bonded to the exposed column upper ends 81 (not shown) by the use of heat, pressure and/or ultrasonic vibration as is practiced conventionally in the wire bonding art. The redistribution conductive balls or bumps 58 may be formed of any applicable metallurgy, and currently are preferably gold, for forming robust gold intermetallic bonds with gold columns 74 in the anisotropically conductive material 60 . Bump placement may be by any applicable method which will form the balls or bumps in desired locations for subsequent joining to another substrate 66 ( FIG. 12 ). For a wire-bondable package 70 , the redistribution conductive ball or bump locations may be selected to provide high-quality, widely pitched wire bonds 62 with the bond pads 52 , as shown in FIGS. 10 and 11 , and simultaneously enable the subsequent formation of short, high quality wire bonds 64 with a substrate 66 , as depicted in FIG. 12 .
[0054] Following the placement and bonding of redistribution conductive balls or bumps 58 on the anisotropically conductive material 60 , the redistribution conductive balls or bumps 58 are wire bonded in act 86 to the bond pads 52 . Act 86 is illustrated in FIGS. 10 and 11 . Although any wire-bonding system may be used, standoff stitch bonding (SSB) is currently preferred. An SSB machine can be used to first apply the redistribution conductive balls or bumps 58 to the upper surface 75 (see FIG. 5 ) of anisotropically conductive material 60 , form a ball 102 on each of the bond pads 52 , then loop and form a stitch bond with the redistribution conductive ball or bump 58 . In addition, the SSB method may be used for final wire bonding of redistribution conductive ball or bump 58 to another substrate 66 , e.g., an interposer.
[0055] The next act 88 is shown as cutting the wafer along cut lines 48 A and 48 B to singulate the discrete dice 50 , using any of the methods well known in the industry. Optionally, a further protective layer (not shown) of insulating material may be applied over the bond pads 52 and adjacent portions of the wire bonds 62 in the wafer stage, i.e., before singulation.
[0056] In act 90 , the redistribution conductive balls or bumps 58 are attached to terminal pads 68 of another substrate 66 by wire bonding. The substrate 66 may be an interposer, a wafer, a partial wafer, another semiconductor die, a circuit board or other electronic component. As illustrated in FIG. 12 , a chip-scale semiconductor package 70 has been formed by the method of the invention and has been wire bonded to terminal pads 68 of substrate 66 . If desired, in act 92 the assembly may be protected by application of a thermoplastic encapsulant over the semiconductor die 50 , wire bonds 64 and terminal pads 68 by transfer molding, injection molding or pot molding, or by so-called “glob top” encapsulation techniques applying a viscous, flowable silicone gel or epoxy encapsulant.
[0057] It should be noted that the present invention is not limited to use with singulated semiconductor dice, but that multidie groupings, sometimes known as “partial wafers,” may also benefit therefrom. For example, in still another embodiment of the invention, the conductive redistribution balls or bumps of the present invention may be used in conjunction with “jumper” bond wires connecting bond pads of adjacent dice of a partial wafer, as well as providing connections to another substrate for two or more dice along, for example, a single edge of the partial wafer.
[0058] The use of anisotropically conductive materials 60 is also very advantageous for flip-chip devices requiring redistribution of I/O locations for a ball grid array (BGA) configuration. The acts in forming such a semiconductor package are shown in FIG. 13 , of which acts 80 , 82 , 84 , 86 , and 88 are the same as described for the wire-bondable package 70 . The method of FIG. 13 differs from that of FIG. 2 in that an additional act 94 is performed to form conductive flip-chip balls or bumps 100 , otherwise known as stud bumps, atop the existing conductive redistribution balls or bumps 58 . This act is illustrated in FIGS. 14 and 15 as being performed at the wafer level. In this act, a ball grid array (BGA) is formed on the active surface portions of the semiconductor dice 50 of the wafer 40 .
[0059] The wafer 40 may then be cut along cut lines 48 A and 48 B to singulate the semiconductor dice 50 , as shown in FIG. 16 . Optionally, prior to singulation in act 88 , a further dielectric layer (not shown) may be applied over portions of the active surface 42 of the wafer 40 , including exposed portions of the active surface 42 , bond pads 52 , anisotropically conductive material 60 , wire bonds 62 and redistribution conductive balls or bumps 58 , leaving conductive flip-chip balls or bumps 100 projecting therefrom.
[0060] In act 96 , shown in FIG. 17 , the package 70 is inverted and the flip-chip balls or bumps 100 of package 70 are attached to a mirror-image set of conductive terminal pads 106 on the substrate 66 . The substrate 66 is shown as an interposer with an internal metallization layer 104 terminating in the conductive terminal pads 106 but, as before, the substrate 66 may comprise a wafer, a partial wafer, another die, a circuit board or other electronic component. In the event that the unsingulated wafer 40 is to be flip-chip bonded to a substrate 66 comprising another wafer or substrate shaped like a wafer, singulation may be performed following flip-chip attach 96 .
[0061] In act 98 , the package 70 may be underfilled with a passivating material 108 , typically an electrically insulative, flowable polymer in gel or viscous liquid form.
[0062] The order of acts shown in FIGS. 2 and 13 need not be followed in a strictly consecutive fashion. Thus, for example, singulation may be performed earlier in the order than shown. In addition, other acts may be added as desired or required to fabricate the final semiconductor die package.
[0063] In another embodiment of the present invention generally formed according to the method of FIG. 13 , an anisotropically conductive material 60 may be used to redistribute peripheral bond pads 52 in a flip-chip package 70 to a central area of the die to form an array of locations suitable for flip-chip attachment using conductive balls or bumps 100 . The acts of FIG. 13 may be used to form this type of package.
[0064] In yet another application of the present invention, partial wafers comprising two or more unsingulated semiconductor dice may be flip-chip attached to another substrate of the present invention. For example, four semiconductor dice joined edge to edge in a row may be simultaneously flip-chip attached to another substrate. Such an approach may be used to fabricate, for example, a multichip memory module.
[0065] The present invention thus provides a lower cost alternative to the use of conventional redistribution layers and requires fewer process steps with the elimination of under-bump metallization. Further, the present invention also provides an effective interim solution for wafer-level packaging in which cost is still unacceptably high for low-yielding wafers and conventional wafer-level packaging technology is not yet fully commercialized.
[0066] Although the foregoing description contains many specific details, these should not be construed as limiting the scope of the present invention, but merely as providing illustrations of some exemplary embodiments. Similarly, other embodiments of the invention may be devised which do not depart from the scope of the present invention. Moreover, features from different embodiments of the present invention may be employed in combination. The scope of the invention is, therefore, indicated and limited only by the appended claims and their legal equivalents, rather than by the foregoing description. All additions, deletions, and modifications to the exemplary embodiments of the invention, as disclosed herein, which fall within the meaning and scope of the claims are embraced thereby. | Methods and apparatus for eliminating wire sweep and shorting while avoiding the use of under-bump metallization and high cost attendant to the use of conventional redistribution layers. An anisotropically conductive (z-axis) conductive layer in the form of a film or tape is applied to the active surface of a die and used as a base for conductive redistribution bumps formed on the anisotropically conductive layer, bonded to the ends of conductive columns thereof and wire bonded to the bond pads of the die. Packages so formed may be connected to substrates either with additional wire bonds extending from the conductive redistribution bumps to terminal pads or by flip-chip bonding using conductive bumps formed on the conductive redistribution bumps to connect to the terminal pads. The acts of the methods may be performed at the wafer level. Semiconductor die assemblies using the present invention are also disclosed. | 7 |
This is a division, of application Ser. No. 443,223 filed Feb. 19, 1974, now U.S. Pat. No. 3,996,308.
BACKGROUND OF THE INVENTION
Anaerobic adhesive systems are those which are stable in the presence of oxygen, but will polymerize in the absence of oxygen. Polymerization is initiated by the presence of a peroxy compound. The cured, cross-linked resins serve as sealants and as adhesives.
Typical resin monomers are terminated with polymerizable acrylate esters such as methacrylate, ethacrylate and chloracrylate esters. The other ingredients typically present are an initiator, preferably an organic hydroperoxide such as cumene hydroperoxide, tertiary butyl hydroperoxide and the like. There is also normally provided a stabilizer against free radical initiation, such as a quinone or hydroquinone, in an amount sufficient to prevent premature polymerization of the adhesive due to decomposition of the peroxy compound. There are also preferably present one or more accelerators which are preferably nitrogen-containing compounds such as tertiary amines, imids, sulfamids and the like which promote the rate of cure.
Cure will be accelerated by the presence of a suitable metal, such as a transition metal, or its ion.
An anaerobic adhesive is applied to one or both of the surfaces to be joined. When the two surfaces are joined and oxygen excluded, cure will be initiated. As is well known, surfaces such as glass may require application of a suitable accelerator such as a transition metal compound, which will increase the rate of cure upon the substantial exclusion of oxygen or air.
Anaerobic adhesives have been well published in the art as for instance, in U.S. Pat. Nos. 2,895,950; 3,041,322; 3,043,820; 3,046,262; 3,203,941; 3,218,305; 3,300,547; 3,435,012, 3,547,851 and 3,625,875.
Anaerobic adhesive systems are typically supplied from a water-like liquid to a light-weight grease in consistency. One end-use application is to apply the adhesive to the threads of a bolt or mating nut which are then assembled. The adhesive fills the spaces between the threads which excludes oxygen and enables cure. In the normal situation, the metals present in the bolt or the nut accelerate cure.
A problem exists, however, in fixturing other surfaces together with initiation and completion of cure, and in providing a controlled quantity of anaerobic monomer to the surfaces to be bonded. No prior art composition provides the desirability and convenience of instant fixturing merely by finger pressure combined with sufficient cured strength to provide bonds of structural integrity.
SUMMARY OF THE INVENTION
According to the present invention, there are provided anaerobic pressure sensitive adhesive compositions which can be applied from or as sheets, tapes and the like to substrates to be bonded by cure upon the exclusion of oxygen.
The anaerobic pressure sensitive adhesives compositions of this invention include a curable anaerobic resin system containing one or more anaerobic resins combined with a thermoplastic polymer system containing one or more high molecular weight thermoplastic polymers, the combination of which alone or upon inclusion of a tackifier, constituting a pressure sensitive adhesive system upon evaporation of essentially all of the solvent present. Further, there is provided in the anaerobic pressure sensitive adhesive composition an initiator system which is latent until made active by substantial exclusion of oxygen, preferably in combination with a suitable accelerator.
In one embodiment, if the anaerobic pressure sensitive adhesive system contains free transition metal ions, then at least the peroxy initiator may be encapsulated in microspheres which, upon rupture, and upon the exclusion of oxygen, will initiate cure. In another embodiment, a suitable metal accelerator may be encapsulated.
If metals which act as accelerators are present and an encapsulated technique is not employed, then the metals should be inactivated. This may be accomplished by scavenging each component of the system with a chelating agent, which may then be removed, if desired.
The thermoplastic polymers used in the preparation of the pressure sensitive anaerobic compositions of this invention are preferably of sufficient molecular weight so as to be elastomeric at room temperature. Further, they must be capable of being combined with the anaerobic resins and not greatly interfere with the creation of a cross-linked latticework of the anaerobic resins and prevent bending of the cured anaerobic polymer to the selected substrates to be joined.
In general, the amount of anaerobic resins combined with the thermoplastic polymer will range from about 35 to about 99% by weight based on the total weight of the anaerobic resins provided and the thermoplastic polymer(s) with which it is combined, and, if present, a tackifier but exclusive of the amount of initiator system added. The preferred amount of anaerobic resin(s) combined in the thermoplastic polymer(s) is from about 55 to about 95% by weight.
In addition, the thermoplastic polymer must be selected such that the composition alone or with tackifiers and upon the inclusion of an initiator system will form, after solvent evaporation, a curable pressure sensitive adhesive layer or film of sufficient cohesive strength to be applied to a substrate from differential release surfaces without disruption of the layer or film. The fully formulated, essentially solvent-free anaerobic pressure sensitive adhesive should be elastomeric at room temperature.
In addition, anaerobic pressure sensitive adhesive compositions should when applied to a surface, wet the surface and conform to the intricacies of the surface so that a uniform bond will be created upon cure and that cure will extend throughout the layer of applied anaerobic pressure sensitive composition to maximize cohesive bond strength.
To constitute a suitable pressure sensitive adhesive of this nature, the net composition when free of solvent should have, prior to cure, a static shear strength of at least about 2 minutes at a 250 gram load per 0.25 square inch and a 180° peel value of at least about 0.5 lb per inch, preferably at least about 1.0 lb per inch when using standard test methods.
DESCRIPTION OF THE INVENTION
According to the present invention there are provided curable anaerobic pressure sensitive adhesive compositions which will cure in the presence of a peroxy or perester compound and in the absence of oxygen.
By the term "anaerobic resin system" as used herein, there is meant one or more anaerobic resins having at least one, preferably two, polymerizable acrylate ester moieties, normally on the ends of the backbone, which will polymerize or cure in the presence of a peroxy initiator and upon the substantial exclusion of oxygen or air, and preferably also in the presence of a suitable accelerator system.
Illustrative, but in no wise limiting, of the anaerobic resins which can be used in the preparation of pressure sensitive adhesive compositions of the invention are polymerizable acrylate esters. As used herein, "acrylate esters" include the alpha-substituted acrylate esters, such as the methacrylate, ethacrylate, and chloroacrylate esters.
Of particular utility as adhesive monomers are polymerizable di-and other polyacrylate esters since, because of their ability to form cross-linked polymers, they have more highly desirable adhesive properties. However, monoacrylate esters can be used, particularly if the non-acrylate portion of the ester contains a hydroxyl or amino group, or other reactive substituent which serves as a site for potential cross-linking. Examples of monomers of this type are hydroxyethyl methacrylate, cyanoethyl acrylate, t-butylaminoethyl methacrylate and glycidyl methacrylate. Anaerobic properties are imparted to the acrylate ester monomers by combining with them a peroxy polymerization initiator as discussed more fully below.
One of the most preferable groups of polyacrylate esters which can be used in the adhesives disclosed herein are polyacrylate esters which have the following general formula: ##STR1## wherein R 1 represents a radical selected from the group consisting of hydrogen, lower alkyl of from 1 to about 4 carbon atoms, hydroxy alkyl of from 1 to about 4 carbon atoms, and the radical ##STR2## R 2 is a radical selected from the group consisting of hydrogen, halogen, and lower alkyl of from 1 to about 4 carbon atoms; R 3 is a radical selected from the group consisting of hydrogen, hydroxyl, and ##STR3## m is an integer equal to at least 1, e.g., from 1 to about 15 or higher, and preferably from 1 to about 8 inclusive; n, is an integer equal to at least 1, e.g., 1 to about 20 or more: and p is one of the following: 0,1.
The polymerizable polyacrylate esters utilized in accordance with the invention and corresponding to the above general formula are exemplified by, but not restricted to the following materials: di-, tri-and tetra-ethylene glycol dimethacrylate, dipropylene glycol dimethacrylate, polyethylene glycol dimethacrylate, di (pentamethylene glycol) dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol di (chloroacrylate), diglycerol diacrylate, diglycerol tetramethacrylate, tetramethylene dimethacrylate, ethylene dimethacrylate, neopentyl glycol diacrylate and trimethylol propane triacrylate.
Yet, another class of acrylate esters are those which are formed by the reaction of:
(a) an acrylate ester containing an active hydrogen atom in the alcoholic moiety of the ester; with
(b) an organic polyisocyanate.
Compositions including this general type of ester are disclosed in U.S. Pat. No. 3,425,988. Preferably, the active hydrogen is the hydrogen of a hydroxyl or a primary or secondary amine substituent on the alcoholic moiety of the ester, and the polyisocyanate is a diisocyanate. Naturally, an excess of the acrylate ester should be used to ensure that each isocyanate functional group in the polyisocyanate is substituted.
The most preferred of the acrylate esters used in the manner described in the preceding paragraph are those in which the acrylate ester is a substituted alkyl or aryl acrylate ester, most preferably having the formula: ##STR4## wherein X is --O-- or ##STR5## wherein R 5 is a hydrogen atom or a monovalent hydrocarbon radical containing up to 10 carbon atoms, and is preferably a hydrogen atom or an alkyl or aralkyl radical with from 1 to 10 carbon atoms; R 2 is as defined above; and R 4 is an alkylene radical with from 1 to 10 carbon atoms, or a divalent aromatic radical containing up to 14 carbon atoms, preferably phenylene, biphenylene or naphthylene.
Naturally R 5 and R 4 can contain any substituents or linkages which do not adversely affect the molecule for its intended use herein.
Typical polyisocyanates which can be reacted with the above acrylate esters to form polyacrylate monomers are toluene diisocyanate, 4,4'-diphenyl diisocyanate, di-anisidine diisocyanate, cyclohexylene diisocyanate, 2-chloropropane diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,2'-diethyl ether diisocyanate, 3-(dimethylamino)-pentane diisocyanate, tetrachlorophenylene diisocyanate-1,4 and trans-vinylene diisocyanate. Still other polyisocyanates that may be used are higher molecular weight polyisocyanates obtained by reacting an excess of any of the above described isocyanates with polyamines containing terminal, primary and secondary amine groups, or polyhydric alcohols, for example, the alkane and alkene polyols such as glycerol, 1,2,6-hexanetriol, 1,5-pentanediol, ethylene glycol, polyethylene glycol, 4,4'-dihydroxydiphenyldimethylmethane and condensation products of alkylene oxides with 4,4'-dihydroxydiphenyldimethylmethane.
Other acceptable monomers which can be used in the compositions according to the invention are acrylate terminated epoxy or ester units, i.e., reaction products of acrylic acid with hydroxy terminated ester or epoxy compounds, or low polymers thereof. Also contemplated by this invention are any other anaerobically curing monomers which, with their respective initiators, accelerators and stabilizers, i.e., inhibitors, are formulated according to the instant invention into a pressure sensitive anaerobic adhesive having the advantageous properties of the compositions of the instant invention.
Naturally, any of the above described acrylate and polyacrylate ester monomers can be used in combination, if desired.
The presently preferred anaerobic monomers are triethyleneglycol dimethacrylate; the reaction product of hydroxypropyl methacrylate with methylene-bis-phenyl-4,4'-diisocyanate a polymer formed by methacrylate capping of a 1:1 adduct of toluene diisocyanate and hydrogenated 2,2-bis (4-hydroxyphenyl) propane as well as mixtures thereof.
There may also be present reactive monomers such as acrylic acid, methacrylic acid and the like which will cross-link with anaerobic monomers.
By the term "thermoplastic polymer system," as used herein, there is meant one or more high molecular weight thermoplastic polymers which, alone or in admixture, have a high enough average molecular weight in order that the resultant curable anaerobic pressure sensitive adhesive composition will have sufficient cohesive strength to be transferred from a conventional release surface to one substrate to be bonded to another substrate, alone, or in combination with a tackifier. Suitable average molecular weight will, of course, vary depending upon the type of thermoplastic polymer or polymer mixtures used, as well as upon the tackifier or tackifiers used, if any. Although it is desired that the polymers employed be compatible with the anaerobic resin system, they may be incompatible forming a heterogeneous system which remains pressure sensitive and transferable in nature and capable of curing. The word "combined" is used herein to indicate any workable combination, regardless of its physical form, of one or more thermoplastic polymers with one or more anaerobic monomers. Thus, a given combination may be a solution or otherwise and may or may not be homogeneous, provided only that it is useful in the pressure sensitive anaerobic composition of the invention.
Typical of the thermoplastic polymers which can be used are polyvinyl chloride, polyvinyl ethers, polyvinyl acetates; acrylic based polymers; polyurethanes, polyesters, polyamids, natural and synthetic elastomers and the like as well as mixtures thereof. The preferred thermoplastic polymers are polyvinyl chloride, polyurethanes, polyesters and acrylic based polymers.
By a "catalyst system" there is meant an acid or base catalyzed system typically containing at least one peroxy initiator, preferably, although not necessarily, at least one accelerator which preferably is a nitrogen containing compound and preferably, although not necessarily, at least one stabilizer against free radical polymerization for the anaerobic resin system.
Typical of the peroxy compounds which may be employed as initiators are the hydroperoxides, preferably organic hydroperoxides of the formula R 6 OOH, wherein R 6 is generally a hydrocarbon radical containing up to about 18 carbon atoms, preferably an alkyl, aryl or aralkyl radical containing from 1 to about 12 carbon atoms. Typical examples are cumene hydroperoxide, methyl ethyl ketone hydroperoxide and the like.
As accelerators there may be mentioned liquid and solid organo-nitrogen compounds including but not limited to organic amides such as formamide, succinimide and the like; tertiary amines such as tributylamine, triethylamine, hexamethyl pararosaniline and the like; aromatic tertiary amines such as dimethyl paratoluidene and the like; organic sulfimides such as benzoyl sulfimide and the like; as well as mixtures thereof. Normally solid organo-nitrogen compounds are particularly preferred as they have the least effect on the viscosity of the resulting composition as well as the least tendency to migrate from the composition.
Typical stabilizers are quinones, hydroquinones, and sterically hindered phenolic compounds.
Depending upon the amount of anaerobic resin system contained in the polymer system, the amount of initiator plus accelerator added will generally range from about 0.5 to about 20 percent or more by weight based on the total weight of the polymer system plus anaerobic resin system, and if present, a tackifier.
By the term "anaerobic pressure sensitive adhesive," there is meant a mixture of the thermoplastic polymer system, anaerobic resin system and the catalyst system and, if desired, a tackifier, which in a solvent-free state is permanently tacky at room temperature, and which firmly adheres to a variety of ordinary surfaces upon contact without the need of more than finger pressure. Further, it must conform to the surface irregularities of normal surfaces and have a sufficient shear modulus to resist removal subsequent to application to a surface.
To meet these criteria, the net, essentially solvent-free composition must have static shear strength of at least 2 minutes using a 250 gram test weight and a 0.25 square inch test surface and a 180° peel strength of at least 0.5 lb per inch, preferably 1.0 lb per inch, when measured by the standard tests specified herein and will separate from a conventional release surface such as a silicone coating and the like, without cohesive failure.
As indicated, a tackifier may be employed to induce or enhance pressure sensitive properties. Typical tackifiers are rosins, rosin derivatives, terpenes, synthetic tacky resins, low molecular weight polyacrylates and the like as well as mixtures thereof. The tackifiers employed in general have a molecular weight less than about 5,000, preferably below about 1,000.
The anaerobic pressure sensitive adhesive compositions of this invention normally contain substantial quantities of anaerobic resins in order that the thermoplastic polymer system employed will not interfere to any great extent with thorough and complete cross-linking or curing of the anaerobic resin system and to maximize bond upon cure. The anaerobic pressure sensitive adhesive compositions may contain, based on a total weight of anaerobic resin system and the thermoplastic polymer system, and if present, tackifiers, from 35 to 99% by weight anaerobic resin system, preferably from about 55 to about 95% by weight and more preferably from about 70 to about 90% by weight.
For certain applications, care should be taken in preparing the anaerobic pressure sensitive adhesives of this invention to cope with trace transition metal ions which may be present in each constituent of the composition, including the anaerobic resin system and the thermoplastic polymer system, typically picked up from the vessels and systems used in their production.
If allowed to remain in the composition, the transition metal ions, while present in concentrations too low to complete cure, may, even at room temperature, consume a certain quantity of the peroxy initiator. As a result, sufficient tackiness may be retained so that pressure sensitive adhesive properties will not be destroyed, but the ability of the composition to cure may diminish to a degree that ultimate bond strength will not be structural. That is, a cross-linked latticework will not develop throughout the applied pressure sensitive composition and cohesive failure may result. If necessary, the effect of transition metal ions in the compositions of this invention may be controlled by means, such as chelation, known to the art. When accelerated cure is desired, however, transition metal compounds (e.g., copper salts) may advantageously be used as primers or activators external to the pressure sensitive anaerobic composition of the invention.
One way to cope with the metal ions is to scavenge them prior to or following their admixture in a mutually compatible solvent prior to casting of the pressure sensitive adhesive layer onto a release liner, which may also require scavenging.
Typical of the solvents which are employed for dissolving the constituents of the pressure sensitive compositions are non-polar aliphatics, aromatics, alcohols and the like which will not affect the peroxy compound. Ketones, for instance, should be avoided. Among the suitable solvents there may be mentioned toluene, isopropyl alcohol and mixtures thereof.
If the constituents of the pressure sensitive adhesive composition are properly scavenged, the active metals can be reintroduced, but in another form. Rather than being active in the composition, their effect may be rendered latent by encapsulating them in microspheres such that they will not be in contact with the peroxy initiator until the microspheres are ruptured upon the application of pressure to react with the peroxy compound to accelerate cure.
An alternative route to prevent premature cure during shelf life or storage is to encapsulate the peroxy compound alone or with its accelerators. Then the active metals or metal ions can be left in the pressure sensitive adhesive composition without fear that premature cure or deactivation will occur.
With care being taken to isolate the peroxy compound of the catalyst system by encapsulation or the elimination or isolation of active metal or metal ions, the pressure sensitive adhesive ingredients can be cast into a film on release coated surfaces or surfaces to be bonded without fear that premature cure or deactivation will occur.
Weight of pressure sensitive adhesive composition applied to a surface to be bonded may be varied over a wide range with the general object of achieving surface wetting for a strong and tenacious bond. Typical coating weights are, after solvent evaporation, from about 12 to about 40 grams of net solids per square meter.
When the anaerobic pressure sensitive adhesive is applied to differential release surfaces, it is required that the applied anaerobic pressure sensitive adhesive layer be removable from the release liner of maximum interfacial bond, typically a silicone coated liner, for transfer to a substrate without cohesive disruption of the anaerobic pressure sensitive adhesive layer. It is desirable for any given application to have the coating as thin as conveniently possible when the surface(s) to which the anaerobic pressure sensitive adhesive is applied provides the active metal accelerator. Cross-linking will then rapidly occur throughout the anaerobic resin and the surfaces will be bonded together. If the coating is too thick, longer cure times will be required or there would be formed an internal weakness which could result in cohesive failure of the partially cured resin.
As an alternative, by employing micro-encapsulated accelerators within the pressure sensitive adhesive composition, greater cure rates and complete cure can be realized. Surface priming with accelerators may also be employed.
In substance, the total anaerobic pressure sensitive adhesive system acts as a binding agent for the anaerobic monomers until cure is complete and then the residual constituents only serve as fillers for the system. However, higher thermoplastic polymer system concentrations can also aid in improving flexural strength of the cured composition at some potential sacrifice in shear strength.
The types of products typically formed are the self-wound tapes, the surface of the supporting tape having differential release properties, sandwich constructions in which the anaerobic pressure sensitive adhesive composition is contained between two carrier liners having differential release surfaces, and similar products. All that is necessary is that the anaerobic pressure sensitive adhesive layer be transferable to a substrate and completely separated from its carriers to leave only an anaerobic pressure sensitive adhesive in contact with the substrate to be bonded to another substrate.
Of course, it is also understood that the liquid anaerobic pressure sensitive adhesive can also be applied directly to a surface to be subsequently joined to another surface, provided the solvent is removed before such joining.
In the following Examples, one or more of the following anaerobic resin systems were employed for the formulation of anaerobic pressure sensitive adhesive compositions:
RESIN I
Approximately 75% of a reaction product of 2 moles of hydroxypropyl methacrylate with 1 mole of methylene-bis-phenyl-4,4'-diisocyanate and 25% triethyleneglycol dimethacrylate.
RESIN II
Approximately 66% of a polymer formed by hydroxypropyl methacrylate capping of a 1:1 adduct of toluene diisocyanate and hydrogenated 2,2-bis (4-hydroxyphenyl) propane, 26% hydroxypropyl methacrylate, 7% acrylic acid and 1% methacryloxypropyltrimethoxysilane.
The following test methods were employed in evaluating the pressure sensitive properties and properties of the cured end-products. In determining pressure sensitive adhesive properties, the adhesive composition was cast on a suitable support such as paper or Mylar tm .
Static Shear Strength -- Federal Test Method Std. No. 147B, Method 20.1 (Load 250 grams) 180° Peel (dynamic -- 12 inches/min) -- ASTM D-1000/68 Lap Shear -- ASTM D-1002/64
EXAMPLE I
To a heated flask equipped with a stirrer and a reflux condenser there was added 1800 grams of toluene, 1200 grams of Resin I and 300 grams of Resin II. The mixture was heated with stirring at 70° C until a homogeneous solution was formed. To the stirred solution there was added 300 grams of a thermoplastic vinyl chloride copolymer known as VAGH-2706 manufactured and sold by Union Carbide Corporation, and the mixture stirred until it again became homogeneous. To the resultant mixture there was added with stirring 180 grams of an aqueous alcoholic solution containing a chelating agent for trace transition metal ions. The solution was held at a temperature between 40°-50° C and stirred for 3 hours and the chelated transition metal ions removed.
To this solution there was added 70 grams of cumene hydroperoxide containing quinone, 37 grams of benzoylsulfimide and 37 grams of methylene-bis-dimethylaniline to form a catalyst system solution.
The anaerobic pressure sensitive adhesive solution was coated onto the release surface of a backing sheet fabricated from a plastic film and a paper having a silicone release coating. Coating weight after solvent removal was 28 grams per square meter. Another release sheet was applied to protect the anaerobic pressure sensitive adhesive.
A portion of the anaerobic pressure sensitive adhesive was tested for pressure sensitive properties. When applied to a paper support, the 250 gram static shear value was 5.5 minutes. The 180° peel test value on a Mylar tm support was 1.75 lbs/in and failure was cohesive. Surface tack was about 2 inches.
Two aluminum alloy plates measuring 1×4×1/16 inches were each etched on one end with a mixture of chromic and sulfuric acids to form a roughened surface. To one roughened surface there was applied a 1/2 ×1 inch layer of the anaerobic pressure sensitive adhesive. The roughened end of the other plate was placed on the anaerobic pressure sensitive adhesive in overlapping relation thereby including oxygen and initiating cure. The copper in the aluminum alloy accelerated cure and the anaerobic pressure sensitive adhesive bonded plates were allowed to cure for 24 hours at room temperature. The bonded plates were tested in an Instron tester and the bond was found to give a lap shear tensile value of 900 psi.
EXAMPLE II
To a reactor equipped with a stirrer there was added at room temperature and with agitation 500 grams of toluene and 350 grams of tackifier known as Arofene tm 8318 (manufactured by Ashland Chemical Co.). Agitation was continued until a solution resulted.
To another reactor there was added with stirring 2700 grams of a polyurethane resin known as Witcobond tm -308, (manufactured by Witco Chemical Co.) 500 grams of toluene and 1000 grams of isopropanol until a solution was formed.
The contents of both reactors were combined and thoroughly mixed. To the resultant solution there was added 500 grams of an alcohol solution containing a chelating agent for transition metals and the mixture stirred for three hours at room temperature.
To the solution there was added 4000 grams of Resin I and the mixture stirred until a solution resulted.
To the resultant solution there was added a catalyst system comprising 240 grams of cumene hydroperoxide containing quinone, 240 grams of benzoylsulfimide and 240 grams of methylene-bis-dimethylaniline.
As in Example I, the anaerobic pressure sensitive adhesive was coated on the release surface of a support and residual solvent removed to form an anaerobic pressure sensitive layer of a weight of 28 grams per square meter. The formed adhesive layer was protected with a second release coated sheet.
The resultant anaerobic pressure sensitive adhesive layer, prior to cure, was determined to have a 250 gram static shear value of from 2.2 to 3.4 hrs, a 180° peel value of 1 lb/in. and a surface tack about 1 inch.
The procedure of Example I to determine lap shear was repeated. The lap shear tensile value was determined to be about 1200 psi. | There is provided a curable anaerobic pressure sensitive adhesive composition, a mixture of a curable anaerobic system and a high molecular weight polymer system. The mixture which may include a tackifier and other functional additives constitutes a pressure sensitive adhesive and exhibits elastomeric properties. There is also provided in the composition an initiator system necessary to permit curing of the anaerobic pressure sensitive composition upon activation by the exclusion of oxygen. One or more accelerators for cure may also be provided.
In one embodiment a component of the catalyst system may be either absent and provided later or latently present in microspheres which upon rupture will enhance the curing operation. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Provisional Application No. 62/011,968, entitled “Cytokine, Chemokine and Growth Factors in Donor Human Milk”, filed Jun. 13, 2014, which is incorporated herein by reference.
STATEMENT OF GOVERNMENT SUPPORT
This invention was made with government support under Grant No. R21 NR013094 awarded by the National Institutes of Health. The government has certain rights in the invention.
FIELD OF INVENTION
This invention relates to milk supplementation. More specifically, the present invention provides for immunologic and growth-factor supplementation of donated breast milk.
BACKGROUND OF THE INVENTION
Human milk is the preferred form of infant nutrition for the first six months of life as recommended by the American Academy of Pediatrics and the World Health Organization. It contains various antibodies and immune cells, along with compounds that prevent pathogenic bacteria or toxins from binding to receptors, such as lysozyme, lactoferrin, and other oligosaccharides (Yilmaz, et al., Interleukin-10 and -12 in human milk at 3 stages of lactation: a longitudinal study. Adv Ther. 2007 May-June; 24(3):603-10). In addition to immune factors, there are hormones and other growth factors, such as epidermal growth factor (EGF), cytokines, such as transforming growth factor (TGF), and chemokines, including various interleukin proteins (IL-6, IL-8, IL-10, IL-13) and tumor necrosis factor proteins (TNFα and TNF-R) (Castellote, et al., Premature delivery influences the immunological composition of colostrum and transitional and mature human milk. J Nutr. 2011 June; 141(6):1181-7). For the first few days after birth, colostrum is expressed from the mammary glands. During this period the tight junctions of the mammary glands are open allowing for transport of components of the maternal blood, resulting in a composition having markedly different biochemical characteristics from mature milk (Espinosa-Martos, et al., Bacteriological, biochemical, and immunological modification in human colostrum after Holder pasteurization. J Pediatr Gastroenterol Nutr. 2013 May; 56(5):560-8). During lactation, the composition changes as the milk transitions from colostrum to mature milk (Castellote, et al., Premature delivery influences the immunological composition of colostrum and transitional and mature human milk. J Nutr. 2011 June; 141(6):1181-7).
There are an estimated 15 million preterm infants born each year, which account for approximately 12% of the births (World Health Organization, Fact Sheet No. 363, last updated November 2014). The colostrum of preterm mothers expresses high levels of immunologic proteins, growth factors, and cytokines which decreases throughout lactation (Castellote, et al., Premature delivery influences the immunological composition of colostrum and transitional and mature human milk. J Nutr. 2011 June; 141(6):1181-7; FIGS. 1 & 2 ). Due to the unique composition of preterm milk, mothers of preterm infants are encouraged to express colostrum, and to establish lactation and pump as much as possible in the ensuing weeks. The American Academy of Pediatrics Recommendations of Breastfeeding Management for Preterm Infants state that all preterm infants should receive human milk and if mother's own milk (MOM) is unavailable, pasteurized donor human milk, appropriately fortified, should be used (The American Academy of Pediatrics. Breastfeeding and the use of human milk. Pediatrics. 2012; 129(3):e827-e841).
However, not all mothers choose to breast feed, or are able to breast feed, and the most vulnerable infants who require human milk are preterm infants. Moreover, maintaining lactation while separated from a very sick and small newborn must be through pumping in most cases as these infants are too small to suckle at breast. For many mothers this becomes difficult and milk volume is not maintained or there are difficulties storing and transporting the milk safely.
The alternative that is supported by the AAP is provision of human milk purchased from milk banks and provided to preterm infants in lieu of formula. Recently, there has been an escalation in the use of banked donor milk in neonatal intensive care units (NICUs), rising from 25.1% nationally in 2007 to 45.2% in 2011 (p<0.001) (Perrine & Scanlon, Prevalence of use of human milk in US advanced care neonatal units. Pediatrics. 2013; 131(6):1066-1071). This steady increase reached an all-time high of 2.15 million ounces of human banked donor milk dispensed by the Human Milk Banking Association of North America in 2011 (Updegrove, Nonprofit human milk banking in the United States [published online Jul. 29, 2013]. J Midwifery Womens Health. doi:10.1111/j.1542-2011.2012.00267.x).
Women who donate milk to milk banks (non-profit and profit) are screened carefully before being determined to be eligible. Milk produced by donor milk banks is pasteurized by the Holder method (62.5° C. for 30 minutes) to remove harmful bacteria and viruses. It is then pooled, packaged, and sold to hospitals for use in their NICUs. The banked donor milk available for purchase from milk banks is pooled from several donors and is more likely to be from mothers who delivered term versus preterm infants (Edwards & Spatz, Making the case for using donor human milk in vulnerable infants. Adv Neonatal Care. 2012 October; 12(5):273-8; quiz 279-80). This is an important distinction as preterm MOM (milk produced by mothers delivering infants at less than 37 weeks gestation) is qualitatively different from term MOM (milk produced by mothers delivering at or after 37 weeks). The literature describes benefits of banked donor milk versus formula, but there are far fewer studies comparing banked donor milk to MOM (Espinosa-Martos, et al., Bacteriological, biochemical, and immunological modifications in human colostrum after Holder pasteurisation. J Pediatr Gastroenterol Nutr. 2013 May; 56(5):560-8; Ewaschuk, et al., Effect of pasteurization on immune components of milk: implications for feeding preterm infants. Appl Physiol Nutr Metab. 2011 April; 36(2):175-82). Since 2011, only 3 additional studies have addressed differences in CCGF between banked donor milk and MOM (Espinosa-Martos, et al., Bacteriological, biochemical, and immunological modifications in human colostrum after Holder pasteurisation. J Pediatr Gastroenterol Nutr. 2013 May; 56(5):560-8; Reeves, et al. TGF-β2, a protective intestinal cytokine, is abundant in maternal human milk and human-derived fortifiers but not in donor human milk. Breastfeed Med. 2013 December; 8(6):496-502; Ewaschuk, et al. Effect of pasteurization on selected immune components of donated human breast milk. J Perinatol. 2011 September; 31(9):593-8; Groer, et al., Cytokines, Chemokines, and Growth Factors in Banked Human Donor Milk for Preterm Infants. J Hum Lact. 2014 Mar. 24; 30(3):317-323).
Holder pasteurization not only destroys bacteria, viruses, and cells but also destroys or significantly reduces levels of immune proteins such as secretory Immunoglobulin A (sIgA) (Ewaschuk et al., Effect of pasteurization on immune components of milk: implications for feeding preterm infants. Appl Physiol Nutr Metab. 2011 April; 36(2):175-82). Immunoglobulin A, the major antibody in human milk, showed a 45% reduction after pasteurization (McPherson & Wagner, The effect of pasteurization on transforming growth factor alpha and transforming growth factor beta 2 concentrations in human milk. Adv Exp Med Biol. 2001; 501:559-66; Braga & Palhares, Effect of evaporation and pasteurization in the biochemical and immunological composition of human milk. J Pediatr (Rio J). 2007 January-February; 83(1):59-63). Lactoferrin, lysozyme, and bile salt-stimulated lipase in milk are also significantly reduced by Holder pasteurization (Christen, et al., Ultrasonication and the quality of human milk: variation of power and time of exposure. J Dairy Res. 2012 August; 79(3):361-6). Heat denaturation of proteins could reduce the concentrations of other immune molecules such as cytokines, chemokines, and growth factors (CCGF), but the effects on only a few of these have been measured.
For example, one study found Holder pasteurization did not markedly affect lactose, glucose, or myoinositol concentrations in milk, but did result in the formation of lactulose and an increase in furosine concentrations (Espinosa-Martos, et al., Bacteriological, biochemical, and immunological modification in human colostrum after Holder pasteurization. J Pediatr Gastroenterol Nutr. 2013 May; 56(5):560-8).
There has been a general assumption that Holder pasteurization not only destroys bacteria, viruses, and cellular components, but also destroys or significant reduces immune proteins such as secretory Immunogloulin A. (Ewaschuk, et al., Effect of pasteurization on immune components of milk: implications for feeding preterm infants. Appl Physiol Nutr Metab, 2011 April; 36(2):175-82). Secretory IgA showed a 45% reduction after pasteurization (Braga & Palhares, (2007). Effect of evaporation and pasteurization in the biochemical and immunological composition of human milk. J Pediatr ( Rio J ), 83(1), 59-63; McPherson & Wagner, The effect of pasteurization on transforming growth factor alpha and transforming growth factor beta 2 concentrations in human milk. Adv Exp Med Biol. 2001; 501:559-66) the major antibody in human milk. All of the cells in milk are destroyed by this process and heat denaturation of proteins would be likely to reduce the concentrations of immune molecules such as cytokines, chemokines and growth factors (CCGF). Few cytokines have been specifically assayed. IL-10 and eythopoietin were both reported to be markedly reduced by Holder pasteurization, while epidermal growth factor (EGF) concentrations were not reduced, although all values were low before pasteurization as the mean month of lactation was 8 months, and all cytokines are higher in early lactation (Untalan, et al., Heat susceptibility of interleukin-10 and other cytokines in donor human milk. Breastfeed Med. 2009 September; 4(3):137-44). Some cytokines appear preserved after Holder pasteurization, such as TGF-β (McPherson & Wagner, The effect of pasteurization on transforming growth factor alpha and transforming growth factor beta 2 concentrations in human milk. Adv Exp Med Biol. 2001; 501:559-66). As noted in a recent review, a thorough evaluation of the effects of pasteurization on human milk is lacking (Ewaschuk, et al., Effect of pasteurization on immune components of milk: implications for feeding preterm infants. Appl Physiol Nutr Metab, 2011 April; 36(2):175-82).
Microbiota, cells, immunoglobulins, lysozyme, lactoferrin, and oligosaccharides in human milk were reported to be reduced after Holder pasteurization, but only 3 studies analyzing a limited number of CCGF had been done (McPherson & Wagner, The effect of pasteurization on transforming growth factor alpha and transforming growth factor beta 2 concentrations in human milk. Adv Exp Med Biol. 2001; 501:559-66; Untalan, et al., Heat susceptibility of interleukin-10 and other cytokines in donor human milk. Breastfeed Med. 2009 September; 4(3):137-44; Goelz, et al., Effects of different CMV-heat-inactivation-methods on growth factors in human breast milk. 2009 April; 65(4):458-61). Cytokines, chemokines, and growth factors in milk are believed to play important roles in gastrointestinal and immune development of the recipient infant (Oddy, The impact of breastmilk on infant and child health. Breastfeed Rev. 2002 November; 10(3):5-18). They affect immune modulation, maturation, and integrity of the gastrointestinal tract as well as control of inflammation in the developing recipient infant (Garofalo, Cytokines in human milk. J Pediatr. 2010 February; 156(2 Suppl):S36-40). The chemokines play a role in cellular chemoattraction and activation of neutrophils, monocytes, and lymphocytes (Garofalo, Cytokines in human milk. J Pediatr. 2010 February; 156(2 Suppl):S36-40). Cytokines, chemokines, and growth factors (CCGF) probably prime intestinal immune cells, contribute to angiogenesis, help develop the intestinal epithelial barrier function, and generally suppress inflammation (Newburg & Walker, Protection of the neonate by the innate immune system of developing gut and of human milk. Pediatr Res. 2007 January; 61(1):2-8). These effects may be even more important when infants are born preterm and therefore have limited in utero development of their physiological systems (Newburg & Walker, Protection of the neonate by the innate immune system of developing gut and of human milk. Pediatr Res. 2007 January; 61(1):2-8) Milk produced by donor milk banks is pasteurized by the Holder method (62.5° C. for 30 minutes) to destroy harmful bacteria and viruses (Updegrove, Nonprofit human milk banking in the United States. J Midwifery Womens Health. 2013 September; 58(5):502-8).
Preterm infants' risks for necrotizing enterocolitis (Sullivan, et al., An exclusively human milk-based diet is associated with a lower rate of necrotizing enterocolitis than a diet of human milk and bovine milk-based products. J Pediatr. 2010 April; 156(4):562-7), sepsis (Schanler, et al., Feeding strategies for premature infants: beneficial outcomes of feeding fortified human milk versus preterm formula. Pediatrics. 1999 June; 103(6 Pt 1):1150-7), and adverse neurodevelopment (Vohr, et al., Persistent beneficial effects of breast milk ingested in the neonatal intensive care unit on outcomes of extremely low birth weight infants at 30 months of age. Pediatrics. 2007 October; 120(4):e953-9) are significantly reduced when infants receive human milk, but these protective effects could be affected by extensive or exclusive use of banked donor milk if there are lower levels of critical immune molecules.
In light of the dearth of information on the relationship between CCGF in banked donor milk and MOM, along with the importance of immunological proteins, and lactation proteins, in the development in early neonatal life, methods of supplementing donor breast milk and formula are needed in the art.
SUMMARY OF THE INVENTION
CCGF in milk are believed to play important roles in gastrointestinal and immune development of the recipient infant. As donor milk becomes more available and used more widely, the effects of pasteurization on immune components may translate into differential risk for these infants. Preterm infants' risks for necrotizing enterocolitis (Sullivan, et al., (2010). An exclusively human milk-based diet is associated with a lower rate of necrotizing enterocolitis than a diet of human milk and bovine milk-based products. J Pediatr, 156(4), 562-567 e561), sepsis (Schanler, et al., (1999). Feeding strategies for premature infants: beneficial outcomes of feeding fortified human milk versus preterm formula. Pediatrics, 103(6 Pt 1), 1150-1157), and adverse neurodevelopment (Vohr, et al., (2007). Persistent beneficial effects of breast milk ingested in the neonatal intensive care unit on outcomes of extremely low birth weight infants at 30 months of age. Pediatrics, 120(4), e953-959) in particular are significantly reduced when infants receive human milk (usually with added human milk fortifier), but the protective effects may be diminished by the exclusive use of donor milk if there is a diminution of critical immune molecules.
As such, a method is presented for supplementing breast milk. Pasteurized breast milk is obtained and tested for at least one protein factor. The protein factor in the pasteurized breast milk is a cytokine, chemokine, or growth factor. Examples of the protein factor are IL-4, MCP-1, MIP-1α, and a combination of these factors. Levels of the protein factor were compared to levels obtained from preterm milk, and low or deficient levels of the protein factor or factors are supplemented by adding one or more additives to the breast milk, where the additive is one or more cytokine, chemokine, or growth factors. Where levels of the protein factor are low or deficient, IL-4, MCP-1, MIP-1α can be added. For example, factors can be supplemented to bring levels of the protein factor within the range of 9 pg/ml to 151 pg/ml for IL-4, 75 pg/ml to 10400 pg/ml for MCP-1, and 10 pg/ml to 493 pg/ml for MIP1α. Nonlimiting examples of levels for IL-4 include 10 pg/ml, 13 pg/ml, 13.54 pg/ml, 15 pg/ml, 15.7 pg/ml, 20 pg/ml, 30 pg/ml, 40 pg/ml, 50 pg/ml, 60 pg/ml, 70 pg/ml, 80 pg/ml, 90 pg/ml, 100 pg/ml, 110 pg/ml, 120 pg/ml, 130 pg/ml, 140 pg/ml, and 150 pg/ml. Nonlimiting examples of levels for MCP-1 include 75 pg/ml, 80 pg/ml, 85 pg/ml, 90 pg/ml, 100 pg/ml, 110 pg/ml, 120 pg/ml, 130 pg/ml, 140 pg/ml, 150 pg/ml, 200 pg/ml, 250 pg/ml, 300 pg/ml, 350 pg/ml, 400 pg/ml, 450 pg/ml, 500 pg/ml, 550 pg/ml, 600 pg/ml, 650 pg/ml, 700 pg/ml, 750 pg/ml, 800 pg/ml, 850 pg/ml, 900 pg/ml, 950 pg/ml, 1000 pg/ml, 2000 pg/ml, 3000 pg/ml, 4000 pg/ml, 5000 pg/ml, 6000 pg/ml, 7000 pg/ml, 8000 pg/ml, 9000 pg/ml, 10000 pg/ml, 10100 pg/ml, 10200 pg/ml, 10300 pg/ml, 10400 pg/ml. Nonlimiting examples of levels for MIP1α include 10 pg/ml, 15 pg/ml, 20 pg/ml, 25 pg/ml, 30 pg/ml, 35 pg/ml, 40 pg/ml, 50 pg/ml, 60 pg/ml, 75 pg/ml, 80 pg/ml, 85 pg/ml, 90 pg/ml, 100 pg/ml, 110 pg/ml, 120 pg/ml, 130 pg/ml, 140 pg/ml, 150 pg/ml, 200 pg/ml, 250 pg/ml, 300 pg/ml, 350 pg/ml, 400 pg/ml, 450 pg/ml, and 493 pg/ml.
Additional factors can be supplemented in the breast milk. At least one supplemental protein factor is tested, where the supplemental protein factor is IL-10, IL-6, IP-10, TNF-α, IL-8, or a combination of these factors. Where levels of the supplemental protein factor are low or deficient, IL-10, IL-8, IP-10, TNF-α, or a combination of these factors can be added. For example, factors can be supplemented to bring levels of the supplemental protein factor within the range of 8 pg/ml to 98 pg/ml for IL-10, 17 pg/ml to 117 pg/ml for IL-6, 18 pg/ml to 254 pg/ml for TNF-α. Nonlimiting examples of levels for IL-10 include 10 pg/ml, 11 pg/ml, 11.8 pg/ml, 12 pg/ml, 13 pg/ml, 13.54 pg/ml, 15 pg/ml, 15.7 pg/ml, 20 pg/ml, 30 pg/ml, 40 pg/ml, 50 pg/ml, 60 pg/ml, 70 pg/ml, 80 pg/ml, 90 pg/ml, and 98 pg/ml. Nonlimiting examples of levels for IL-6 include 17.69 pg/ml, 18 pg/ml, 20 pg/ml, 25 pg/ml, 26.9 pg/ml, 28 pg/ml 30 pg/ml, 35 pg/ml, 40 pg/ml, 50 pg/ml, 60 pg/ml, 75 pg/ml, 80 pg/ml, 85 pg/ml, 90 pg/ml, 100 pg/ml, 110 pg/ml, and 117 pg/ml. Nonlimiting examples of levels for TNF-α include 18 pg/ml, 20 pg/ml, 21.17 pg/ml, 23.2 pg/ml, 24 pg/ml, 25 pg/ml, 30 pg/ml, 40 pg/ml, 50 pg/ml, 60 pg/ml, 70 pg/ml, 80 pg/ml, 90 pg/ml, 100 pg/ml, 110 pg/ml, 120 pg/ml, 130 pg/ml, 140 pg/ml, and 150 pg/ml. 160 pg/ml, 170 pg/ml, 180 pg/ml, 190 pg/ml, 200 pg/ml, 210 pg/ml, 220 pg/ml, 230 pg/ml, 240 pg/ml, 250 pg/ml, and 254 pg/ml. In specific variations of the invention, EGF is added to remediate low levels or deficient levels in EGF.
In some variations, the breast milk is pasteurized by treatment at 62.5° C. for 30 minutes, 63° C. for 30 minutes, 62° C. for 5 seconds, 65° C. for 5 seconds, or 72° C. for 5 seconds. Optionally, the breast milk is preterm milk, such as human preterm milk.
In certain variations of the invention, at least one lactation protein is also added. Examples of the lactation protein are lysozyme, lactoferrin, and a combinations of these proteins. The lactation protein is optionally added to reach a level of lysozyme of between about 63 g/L and about 173 g/L, and/or a level of lactoferrin of between about 0.78 g/L and about 1.33 g/L.
The methods presented herein may alternatively be used to supplement formula. In variations of the invention pertaining to formula, formula is obtained and supplemented with at least one protein factor in preterm milk to bring the at least one protein factor to levels equivalent to those found in preterm milk. The protein factor is IL-4, MCP-1, MIP-1α, or a combination of the aforementioned factors. The protein factor or factors are optionally supplemented by adding one or more additives to reach levels or ranges of the protein factor disclosed above. In some variations, additional factors can be supplemented in the formula. At least one supplemental protein factor is added to the formula, where the supplemental protein factor is IL-10, IL-6, IP-10, TNF-α, IL-8, or a combination of these factors. In further variations, the supplemental protein factor is supplemented to bring levels of the supplemental protein factor within a level or range as disclosed above. In specific variations of the invention, EGF is added to remediate low levels or deficient levels in EGF. In certain variations of the invention, at least one lactation protein is also added. Examples of the lactation protein are lysozyme, lactoferrin, and a combinations of these proteins. The lactation protein is optionally added to reach levels as disclosed above.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which:
FIG. 1 is a graph showing Mothers' Own Milk (MOM) Volumes (mL/wk) over 6 weeks of Neonatal Intensive Care Unit (NICU) stay. Values shown are mL of MOM produced over 1-week time spans beginning from the end of week 1 to the end of week 6 of a NICU stay. For week 1, n=45; for week 2, n=36; for week 3, n=36; for week 4, n=33; for week 5, n=26; for week 6, n=20. Bars are standard errors of the mean.
FIG. 2 is a graph showing the average (mean) of cytokines from preterm Mothers' Own Milk over time compared to banked donor milk. Error bars represent standard errors of the means.
FIG. 3 is a graph of the log 10 of chemokine and growth factor averages in preterm Mothers' Own Milk over time compared to banked donor milk. Error bars represent standard errors of the means.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As used herein, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a polypeptide” includes a mixture of two or more polypeptides and the like.
As used herein, “about” means approximately or nearly and in the context of a numerical value or range set forth means±15% of the numerical.
As used herein the term “patient” is understood to include an animal, especially a mammal, and more especially a human that is receiving or intended to receive treatment.
As used herein “animal” means a multicellular, eukaryotic organism classified in the kingdom Animalia or Metazoa. The term includes, but is not limited to, mammals. Nonlimiting examples include rodents, mammals, aquatic mammals, domestic animals such as dogs and cats, farm animals such as sheep, pigs, cows and horses, and humans. Wherein the terms “animal” or the plural s are used, it is contemplated that it also applies to any animals.
As used herein “pasteurize” or “pasteurized” means to subject a material to a treatment process to reduce the number of pathogens on or within the material. The treatment process includes subjecting the material to sufficient heat for a sufficient time frame or filtration, thereby rendering microbes, molds, and viruses non-viable or inactive, without substantially altering the chemical composition of the material. The terms “pasteurize” or “pasteurized” are intended to encompass the terms “sterilize” and “sterilization” where the treated material is substantially free of microbial and mold growth or viral load/infectivity. Examples of pasteurization include Holder pasteurization, wherein the material is heated to 62.5° C. for 30 minutes or 63° C. for 30 minutes (Czank, et al., Retention of the immunological proteins of pasteurized human milk in relation to pasteurizer design and practice. Pediatr Res. 2009 October; 66(4):374-9; Goelz, et al., Effects of different CMV-heat-inactivation-methods on growth factors in human breast milk. Pediatr Res. 2009 April; 65(4):458-61); high-temperature, short-time (HTST, i.e. “flash”) pasteurization wherein the material is flowed against a plurality of thermally-conductive plates and rapidly heated to 72° C. (161° F.) for 15 seconds; ultra-heat-treating (UHT), wherein the material is rapidly heated to 140° C. (284° F.) for four seconds; 62° C. for 5 seconds, 65° C. for 5 seconds, or 72° C. for 5 seconds (Goelz, et al., Effects of different CMV-heat-inactivation-methods on growth factors in human breast milk. Pediatr Res. 2009 April; 65(4):458-61).
As used herein “cytokine” means a small protein, polypeptide, or active fragment, which is released by a cell to alter the behavior of another cell, i.e. mediates interactions between cells. Cytokines are typically between 5 and 20 kilodaltons (kDa). The protein acts through a receptor to induce a cell signaling response. Nonlimiting examples of cytokines contemplated here include lymphokines, interferons (IFNs), colony stimulating factors (CSFs), interleukins (ILs) (including IL-10), CD antigens and tumor necrosis factors (TNFs). The cytokines can include homodimeric cytokines, i.e. signaling molecules formed from two identical subunits, and heterodimeric cytokines, i.e. signaling molecules formed from two distinct subunits. A nonlimiting example of a heterodimeric cytokine is interleukin-12 (IL-12), which is formed from a p35 subunit and a p40 subunit.
As used herein “chemokine” (chemotactic cytokine) means a protein, polypeptide, or active fragment, which is released by a cell resulting in chemotaxis, i.e. the ability to directly stimulate directed movement of cells, Chemokines are typically between 8 and 10 kilodaltons (kDa) and generally possess conserved regions with four cysteine residues including cys-cys or cys-X-cys. The protein acts through a G-protein-linked receptor to induce a cell signaling response. Chemokines are classified into four main subfamilies: CXC, CC, CX3C and XC. Chemokines include, without limiting the scope of the invention, RANTE5, MIP-1α, MIP-1β, SDF-1. Tests to determine if a polypeptide possesses chemotactic activity for a population of cells can be readily determined by employing any known assay for cell chemotaxis to determine induction or prevention of chemotaxis. Such assays measure the ability of a protein to induce the migration of cells across a membrane as well as the ability of a protein to induce the adhesion of one cell population to another cell population, such as, without limitation, those described in: Current Protocols in Immunology, Ed, by J. E. Coligan, A. M. Kruisbeek, D. H. Margulies, E. M. Shevach, W. Strober, Pub. by Greene Publishing Associates and Wiley-Interscience (Chapter 6.12, Measurement of alpha and beta Chemokines 6.12.1-6.12.28); Taub et al., J. Clin. Invest. 95:1370-1376, 1.995; Lind et al., APMIS 103:140-146, 1995: Muller et al., Eur. J. Immunol, 25: 1744-1748: Gruber et al., J. of Immunol. 152:5860-5867, 1994; Johnston et al., J. of Immunol. 153: 1.762-1768, 1994; all of which are incorporated herein by reference.
As used herein “growth factor” means a naturally occurring protein or steroid compound possessing the ability to stimulate cell growth, proliferation, healing or differentiation.
As used herein “preterm milk” means milk produced by mammary glands of mothers whom delivered infants “preterm”.
As used herein “preterm” means an infant delivery that occurs before 37 weeks of gestation. The term includes spontaneous preterm delivery and medically induced preterm delivery. Spontaneous preterm delivery (sPTD) means spontaneous delivery 20 to <36 weeks gestation, and includes, without being limited to the specific embodiment, very preterm delivery (VPTD), which mean 20-<33 weeks gestation; moderate preterm delivery (MPTD), which is 33-<36 weeks gestation; spontaneous preterm labor/delivery (sPTL, clinical presentation of sPTD), and spontaneous preterm premature rupture of membranes (PPROM).
As used herein “remediate” means to elevate one or more cytokine levels, chemokine levels, growth factor levels, or lactation protein level to a level within a normal range for the cytokine, chemokine, growth factor, or lactation protein in preterm milk. A normal range is defined as a range of 1 or 2 standard deviations of levels of the cytokine, chemokine, growth factor, or lactation protein obtained from a plurality of samples of preterm milk, based on statistical analysis. As used in the definition, lactation proteins include lysozyme, lactoferrin, and lipase.
As used herein “low levels” means a level of a cytokine, chemokine, growth factor, or lactation protein that is 70%, or less, of the value found in preterm milk. The value used for determining low levels can be the mean value of the cytokine, chemokine, growth factor, or lactation protein in preterm milk, the value representing the lower range for the cytokine, chemokine, growth factor, or lactation protein in preterm milk, or the value representing the upper range for the cytokine, chemokine, growth factor, or lactation protein in preterm milk.
As used herein “deficient levels” means a level of a cytokine, chemokine, growth factor, or lactation protein that is absent or up to 10%, or less, of the value found in preterm milk. The value used for determining low levels can be the mean value of the cytokine, chemokine, growth factor, or lactation protein in preterm milk, the value representing the lower range for the cytokine, chemokine, growth factor, or lactation protein in preterm milk, or the value representing the upper range for the cytokine, chemokine, growth factor, or lactation protein in preterm milk.
Example 1
Mothers of preterm infants less than 1500 g were consented when their newborns were admitted to the hospital NICU. Collection of mother's own milk was obtained after obtaining informed consent, and samples collected by the end of the first week of admission. Exclusion criteria were moribund status, major congenital anomalies, HIV positive status of mothers. A demographic questionnaire was conducted and infant data, including medical complications, weight, feeding and date of discharge, were obtained from nursing and medical charts.
There were 45 maternal infant dyads included in the analysis. The majority of mothers were high school graduates (58%), were single (49%), were poor (income under $25,00/year) (53%), and were primiparous (34%). There were 25% smokers, and 4% self-reported illegal drug use. The mean BMI was 27.6±6.4. The racial composition was 53% Caucasian, 41% African American, 2% Asian-American and 2% other. Twenty four percent considered themselves of Hispanic ethnicity. There were equal numbers of boys and girls born. The infants were evaluated using the appearance, pulse, grimace, activity, respiration (APGAR) test, with each factor having a score of 0, 1, or 2. The mean 2 minute APGAR was 5.93 and the 5 minute APGAR was 7.9. The mean birth weight was 1107±223 g, with a mean gestational age of 28.3±2.33 weeks.
All mothers were encouraged to lactate and provide milk throughout their infants' stay in the NICU. Twenty-five pooled samples of banked donor milk were analyzed and compared to 196 pooled weekly samples of mothers own milk (which represented nearly 2000 samples of daily milk collection). The weeks of collection were from week 1 through week 6 of the infant's admission to the NICU, or until the mother ceased providing mother's own milk (MOM). The number of mothers providing MOM declined over time due to hospital discharge before 6 weeks (N=10), neonatal death (N=2), and change from MOM to formula (N=9) or to banked donor milk (N=8) between weeks 2 to 6. Table 1 shows the number of infants receiving exclusive breast milk by week of admission. This data generally presents the decline in exclusive breast milk feeding.
TABLE 1
Number of infants receiving exclusive mothers'
own milk over time (n = 41).
Week 1
Week 2
Week 3
Week 4
Week 5
Week 6
38
32
32
29
22
18
93%
78%
78%
71%
54%
44%
Many mothers provided MOM for the first week or two and then there was a drop off. Donor milk was acquired from banks that specify the donor mothers test negative for HIV, human t-cell lymphotrophic virus, hepatitis B and C, and syphilis, who do not smoke, who drink no more than 2 alcoholic drinks per day, do not use illegal drugs, and breast-feed an infant of 1 year of age or less. Exact volumes of MOM, human milk fortifier (bovine-based), formula, and donor milk were recorded at every feeding. The donor milk being given with greater frequency in the past six months was purchased from a single non-profit milk bank in Northern Texas. This milk was shipped frozen in aliquots and thawed and measured and either mixed with mother's own milk if it is available or given as the full feeding, the amount determined by the caloric needs of the infant each day.
At each feeding an aliquot of 0.5 ml of milk was removed by tuberculin syringe by the nurse, prior to fortifier, formula, or banked donor milk supplementation, and was labeled and frozen at −20° C. until pickup and delivery to the lab within 2-3 days. The donor milk being used for some infants was also treated in the same manner as the mother's own milk, and supplemental donor milk was collected prior to addition to MOM as described above. The frozen samples for each week were thawed, pooled, centrifuged at 1000 g at 4° C. for 10 minutes, defatted by spooning the fat layer using a Corning spoon No. 3004 (ThermoFisher Scientific, Waltham, Mass.). The whey fraction was filtered through a 0.45 μm Millipore low protein binding PVDF filter (No. SLHVM23N S; ThermoFisher Scientific, Waltham, Mass.) then refrozen at −80° C. in 2 ml Eppendorf tubes (Eppendorf AG, Hamburg, Germany) until analysis. It was noted that MOM samples underwent more than one freezing-thaw cycle, while banked donor milk also went through more freeze-thaw cycles than MOM, which may have further reduced CCGF concentrations. However, previous studies have shown up to 3 freeze-thaw cycles do not significantly alter milk CCGF levels (unreported data; Ramirez-Santana, et al. Effects of cooling and freezing storage on the stability of bioactive factors in human colostrum. J Dairy Sci. 2012; 95(5):2319-2325).
The volumes of MOM produced by the mothers over the 6 weeks of data collection increased over time (<500 mL/week at week 1 to >1500 mL/week at week 6), as seen in FIG. 1 .
The weekly-pooled whey was analyzed through multiplexing with the use of Millipore magnetic bead kits (EMD Millipore, Billerica, Mass.) according to kit directions and analyzed on a MagPix (Luminex Corp., Austin, Tex.). Before analysis a series of experiment were done spiking different matrix solutions to optimize the assay.
Multiplexing allows for quantitative measurements of multiple analytes in a small volume of fluid (25 μL) and is based on attachment of the CCGF to magnetic beads and processing using LED excitation. The MAGPIX machine was calibrated and the kits' standards and controls used to determine the values in pg/mL of the CCGF. Before analysis, a series of experiments were performed by spiking known concentrations of CCGF in different matrix solutions to optimize the multiplex assay. The matrix solution that produced the best recovery (up to 100% for some CCGF) was used for all subsequent analysis. This was a commercial serum matrix used for serum and plasma analyses and was purchased from Millipore and added to standards, controls, and samples. The CCGF analyzed were epidermal growth factor (EGF), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10), macrophage inflammatory protein-α (MIP-1α), monocyte chemotactic protein (MCP), and interferon gamma inducible protein-10 (IP-10), as seen in Tables 2 and 3. This panel of cytokines, chemokines, and growth factors was chosen due to differences in the protein concentrations in preterm versus term milk and they are all reported to be biologically active in human milk (Chatterton, et al. Anti-inflammatory mechanisms of bioactive milk proteins in the intestine of newborns. Int J Biochem Cell Biol. 2013; 45(8):1730-1747).
TABLE 2
Cytokine, chemokine, and growth factor data for week
1 of preterm mother's own milk (pg · mL).
N
Minimum
Maximum
Mean
Std. Deviation
EGF
43
242
21043
11302.48
5845.865
IL10
43
0
88
11.80
20.647
IL4
43
0
151
13.54
30.840
IL8
43
2
19224
770.76
2956.833
IL6
43
1
117
26.90
27.761
IP10
43
257
14515
2461.88
3580.585
MCP1
43
89
10400
2714.39
2834.137
MIP1
43
0
493
38.63
99.312
TNFa
43
2
110
23.19
22.030
TABLE 3
Cytokine, chemokine, and growth factor data for week
2 of preterm mother's own milk (pg · mL).
N
Minimum
Maximum
Mean
Std. Deviation
EGF
37
1403
18149
11821.46
5277.679
IL10
37
0
98
11.83
19.816
IL4
37
0
109
15.71
28.461
IL8
37
2
1497
150.44
296.706
IL6
37
0
95
17.69
20.370
IP10
37
261
9464
1991.37
2220.565
MCP1
37
75
9342
1897.25
2413.097
MIP1
37
0
165
13.17
29.612
TNFa
37
0
254
21.17
41.228
The levels of CCGF were compared between MOM at each lactational week and the pooled banked donor milk. The data for both sample groups were not normally distributed, thus differences were analyzed by Mann-Whitney U tests. To compare changes in MOM CCGF levels from week 1 to week 6, the CCGF were log 10 transformed and t tests between weeks 1 and 6 were performed for each protein. A p value of 0.05 was accepted for statistical significance and SPSS, version 21 (International Business Machines Corporation, Armonk, N.Y.), was used for analysis. Graphs of cytokines and growth factors depict the log 10 on the vertical axis due to the large differences in concentrations between EGF and the chemokines.
Analysis of the donor milk showed that cytokines were present in the donor milk samples. In the first week, there were statistically significant differences between MOM and banked donor milk for all but 3 CCGF (IL-4, EGF, MIP-1α). By week 6, the only CCGF levels that were significantly different were MIP-1α and TNF-α. All other CCGF levels were not significantly different in MOM at 6 weeks versus banked donor milk, as seen in Table 4.
TABLE 4
Comparison of CCGF in preterm mother's own milk using Mann Whitney U, collected
from weeks 1 through 6 of NICU hospitalization, to banked donor milk. a
Week #
IL-10
IL-4
IL-6
TNF-α
EGF
IP-10
MCP-1
MIP-Iα
IL-8
1*
−3.02 c
−0.91
−4.3 d
−5.13 d
1.13
−3.88 d
−3.32 d
−1.35
−4.21 d
2**
−2.47 b
−1.37
−3.17 d
−4.3 d
−1.26
−3.61 d
−2.4 b
−0.253
−2.08 b
3**
−0.575
−1.23
−2.33 b
−3.94 d
−1.07
−3.26 d
−1.67
−1.67
−1.8
4†
−0.628
−0.436
−1.84
−3.56 d
−0.36
−3.2 d
−1.37
−1.99 b
−1.12
5 ††
−0.134
−0.024
0.801
−2.48 b
−0.27
−1.69
−0.452
−1.6
−0.63
6‡
−0.012
−0.095
−0.549
−2.25 b
−0.289
−0.754
−0.297
−2.14 b
−0.89
Abbreviations: CCGF, cytokines, chemokines, and growth factors; EGF, epidermal growth factor; IL, interleukin; IP, interferon gamma inducible protein; MCP, monocyte chemotactic protein; MIP, macrophage inflammatory protein; NICU, neonatal intensive care unit; TNF, tumor necrosis factor.
*N = 44;
**N = 36;
†N = 33;
††N = 26;
‡N = 20.
a Data are Mann-Whtney U Z values in preterm MOM CCGF compared to donor milk CCGF (N = 25).
b p < 0.05;
c p < 0.01;
d p < 0.001.
FIG. 2 depicts the mean levels of the 4 cytokines from weeks 1 to 6 for MOM and the levels in banked donor milk. The level of each cytokine generally decreased over time, but the difference between week 1 and week 6 was statistically significant only for TNF-α (t=4.38, df=62, p<0.001) and IL-6 (t=5.28, df=62, p<0.001). FIG. 3 shows the Log 10 means of the cytokines and growth factors over time for MOM over the course of the study, i.e. from weeks 1 through 6, and the levels found in banked donor milk. There is a significant decline over time in the levels of each cytokine, with the exception of EGF, while chemokines and growth factors concentrations are more preserved. Values were determined as follows; MIP-1α (t=3.17, df=62, p<0.002), IP-10 (t=3.309, df=62, p<0.004), IL-8 (t=3.92 df=62, p<0.001), and MCP-1 (t=4.07, df=62, p<0.001) When comparing donor milk to mother's own milk, a fair comparison would be to test week 6 mothers' own milk, which is mature milk by this stage of lactation against the donor milk, the maturity of which is unknown, but is certainly mature milk. The comparison is presented in Table 5.
TABLE 5
CCGF in mothers' own milk at 6
weeks postpartum compared to donor milk.
Mother's own milk (n = 18)
CCGF
Donor milk (n = 11)
(pg/ml)
M
SD
M
SD
t
P
IL-10
5.5
11.4
1.5
2.5
1.5
0.15
IL-4
5.4
13.6
2.2
4.5
0.92
0.37
IL-6
10.5
29.8
9.4
12.9
0.14
0.89
TNF-α
9.5
9.7
1.7
2.1
3.3
0.002
IL-8
76.6
217.4
24.5
16.9
1.03
0.31
IL-10
1110.9
1475.2
764.2
668.5
2.1
0.04
MCP-1
630.7
828.2
1164.03
1582.3
4.2
0.000
MlP-1α
3.42
12.3
7.2
15.3
2.03
0.049
EOF
10142.0
5818.1
10418.9
7167.2
−0.114
0.91
The data show that preterm milk cytokines decline over time, as expected, although the chemokines such as IL-8, MCP1, IP-10, and MIP-1α appear highly conserved. There is a great deal of variation over time between individual woman's milk samples. Further, there is in general a surprising retention of CCGF in donor milk subjected to Holder pasteurization. The banked donor milk possessed CCGF concentrations that are relatively equivalent to mature milk (MOM) produced after 6 weeks of lactation by mothers of preterm infants. However, preterm infants fed with banked donor milk, instead of MOM, during the first weeks of life accordingly are receiving less of the critical CCFGs.
Holder pasteurization is the method of choice for sterilizing human milk, and the measured CCGF appears to possess some heat-resistant properties, refuting the belief that Holder pasteurization eliminates immune components. The only cytokines that are significantly different in donor milk are TNF-α and IL-10 at 6 weeks postpartum. Most of the significant chemokines are lower in donor milk, but still present in high concentrations. While they are not denatured, it is not clear if they remain functional. This information agrees with a recent publication which used multiplexing of similar CCGFs (Espinosa-Martos, et al., Bacteriological, biochemical, and immunological modification in human colostrum after Holder pasteurization. J Pediatr Gastroenterol Nutr. 2013 May; 56(5):560-8), which showed measurable CCGF in both Holder pasteurized colostrum and mature milk. Differences may be due to effects of the matrix used, as analytes in many human milk samples have been found to exhibit significant matrix effects on measurement values when using the manufacturer's (Millipore) kits and matrix solutions. In the present analysis, the matrix was serum matrix from Millipore added to controls, standards, and samples, which was previously reported to provide a successful milk matrix for multiplexing (Groer, et al., Multiplexing of human preterm and term cytokines. FASEB J . April 2013; 27(Meeting Abstract Supplement):629.7).
Banked donor milk is increasingly being used to feed preterm infants in lieu of formula because there is good evidence that it has protective properties similar to those of MOM (Heiman & Schanler, Benefits of maternal and donor human milk for premature infants. Early Hum Dev. 2006; 82(12):781-787). There are, however, unknown characteristics of banked donor milk (maternal factors, heat resistant viruses, developmental stages of lactation, processing, pooling, freezing) that might influence its bioefficacy and safety (Menon & Williams, Human milk for preterm infants: why, what, when and how? Arch Dis Child Fetal Neonatal Ed. 2013; 98(6):F559-F562). Neonatal intensive care units make decisions about when to institute and discontinue banked donor milk, based at least in part on the cost/benefit ratio of banked donor milk (Arnold, The cost-effectiveness of using banked donor milk in the neonatal intensive care unit: prevention of necrotizing enterocolitis. J Hum Lact. 2002; 18(2):172-177; Jegier, et al., The institutional cost of acquiring 100 mL of human milk for very low birth weight infants in the neonatal intensive care unit. J Hum Lact. 2013; 29(3):390-399). For example, in the study NICU, banked donor milk is stopped and formula instituted around 34 weeks gestational age, a point at which the risk for necrotizing enterocolitis and infection are greatly reduced (Sharma R, Hudak ML. A clinical perspective of necrotizing enterocolitis: past, present, and future. Clin Perinatol. 2013; 40(1):27-51).
Data suggest that banked donor milk may not be developmentally appropriate in terms of CCGF during the early weeks of life in low birth weight infants, but it is superior to formula, which contains no CCGFs. Although not confirmed, it is plausible that critical periods in preterm infant development are aligned with milk biology (Menon & Williams, Human milk for preterm infants: why, what, when and how? Arch Dis Child Fetal Neonatal Ed. 2013; 98(6):F559-F562). Cytokines in milk decline over time of lactation, which may be timed to coincide with maturation of the neonatal gut and immune system (Ustundag, et al. Levels of cytokines (IL-1β, IL-2, IL-6, IL-8, TNF-α) and trace elements (Zn, Cu) in breast milk from mothers of preterm and term infants. Mediators Inflamm. 2005; 2005(6):331-336; Kverka et al. Cytokine profiling in human colostrum and milk by protein array. Clin Chem. 2007; 53(5):955-962; Hawkes, et al. Cytokines (IL-1beta, IL-6, TNF-alpha, TGF-beta1, and TGF-beta2) and prostaglandin E2 in human milk during the first three months postpartum. Pediatr Res. 1999; 46(2):194-199; Castellote, et al., Premature delivery influences the immunological composition of colostrum and transitional and mature human milk. J Nutr. 2011; 141(6):1181-1187).
A prospective study of milk from mothers reported that protein levels were higher in preterm milk over 8 weeks of lactation (Bauer J, Gerss J. Longitudinal analysis of macronutrients and minerals in human milk produced by mothers of preterm infants. Clin Nutr. 2011; 30(2):215-220). In a recent Korean study, the composition of milk to 3 months postpartum was compared between mothers who delivered preterm and a cohort of term mothers, and some differences in milk fatty acid composition were described (Jang, et al., Serial changes of fatty acids in preterm breast milk of Korean women. J Hum Lact. 2011; 27(3):279-285). In another study, beta-endorphin levels at 30 days postpartum did not differ between preterm and term milk (Zanardo, et al., Beta endorphin concentrations in human milk. J Pediatr Gastroenterol Nutr. 2001; 33(2): 160-164).
Neonatal intensive care units are using banked donor milk with greater frequency (Delfosse, et al., Donor human milk largely replaces formula-feeding of preterm infants in two urban hospitals. J Perinatol. 2013; 33(6):446-451). Preterm infants fed exclusively or predominantly with banked donor milk during the first weeks of life will receive lower levels of these immune components than if fed MOM. As such, supplementing the banked milk with immune components and/or other lactation proteins assists in the care of preterm infants and newborns.
Example 2
Banked donor milk is obtained from a milk bank, generally from banks that specify the donor mothers are healthy, test negative for HIV, human t-cell lymphotrophic virus, hepatitis B and C, and syphilis, who do not smoke, who drink no more than 2 alcoholic drinks per day, do not use illegal drugs, and breast-feed an infant of 1 year of age or less. An aliquot of 0.5 ml of milk is removed using a syringe, centrifuged at 1000 g at 4° C. for 10 minutes, defatted by spooning the fat layer using a Corning spoon No. 3004 (ThermoFisher Scientific, Waltham, Mass.). The whey fraction was filtered through a 0.45 μm Millipore low protein binding PVDF filter (No. SLHVM23N S; ThermoFisher Scientific, Waltham, Mass.) and the processed fraction tested to determine the levels of CCGF, as discussed in Example 1. Alternatively, enzyme-linked immunosorbent assay (ELISA) can be used to determine CCGF levels.
Levels of the CCGF in the bank milk are compared to levels of CCGF in preterm milk-early MOM, identified in Example 1. Protein factors or recombinant protein factors, such as IL-4, IL-10, IL-6, IL-8, IP-10, TNF-α, IL-8, MCP-1, and MIP-1α (Life Technologies, ThermoFisher Scientific, Inc. Carlsbad, Calif.) are added to the banked milk as needed, based on the analysis of the banked milk compared to preterm milk-early MOM. For example, for preterm infants, a comparison of preterm milk to banked milk may indicate a difference in TNF-α of 3.7 pg/ml, necessitating the addition of 3.7 pg/ml TNF-α to the bank milk. CCGF levels may be compared based on mean CCGF for the specific cytokine, chemokine or growth factor, the lower limit for the specific cytokine, chemokine or growth factor, or the upper limit for the specific cytokine, chemokine or growth factor. After analysis of the protein factors, and addition of protein factors as required to remediate low or deficient levels of one or more protein factors, the banked milk should approximate the immunological and growth factor properties of preterm milk
Example 3
Banked donor milk can also be tested for lactation proteins. Banked donor milk is obtained from a milk bank, generally from banks that specify the donor mothers test negative for HIV, human t-cell lymphotrophic virus, hepatitis B and C, and syphilis, who do not smoke, who drink no more than 2 alcoholic drinks per day, do not use illegal drugs, and breast-feed an infant of 1 year of age or less. The milk is typically shipped frozen in aliquots and thawed and measured and either mixed with mother's own milk if it is available or given as the full feeding, the amount determined by the caloric needs of the infant each day. An aliquot of 0.5 ml of milk is removed using a syringe, centrifuged at 1000 g at 4° C. for 10 minutes, defatted by spooning the fat layer using a Corning spoon No. 3004 (ThermoFisher Scientific, Waltham, Mass.). The whey fraction was filtered through a 0.45 μm Millipore low protein binding PVDF filter (No. SLHVM23N S; ThermoFisher Scientific, Waltham, Mass.) and the whey fraction tested to determine the levels of proteins. Alternatively, ELISA can be used to test for protein levels. Advantageously, this can be performed concurrently with CCGF testing, in addition to CCGF testing, or independently from CCGF testing or embodiments using CCGF. Banked donor milk can then be supplemented at the same time, or at different times, from CCGF supplementation.
Lactation protein assays can be conducted using available kits, such as human lysozyme enzyme immunoassay (Biomedical Technol., Inc., Ward Hill Mass.), sandwich assays (Czank, et al., et al., Retention of the immunological proteins of pasteurized human milk in relation to pasteurizer design and practice. Pediatr Res. 2009 October; 66(4):374-9; Prentice, et al., The nutritional role of breast milk IgA and lactoferrin. Acta Paediatr Scand. 1987 July; 76(4):592-8), or ELISA assay. After analysis of the lactation proteins, and addition of one or more lactation proteins as required to remediate low or deficient levels of one or more proteins, the banked milk should approximate the lactation protein properties of preterm milk.
Example 4
Formula can be supplemented using cytokines, chemokines, growth factors, and by supplementing lactation proteins, as noted in the above examples. Formula can be analyzed similarly to breast milk when in a suspended state, i.e. any lyophilized or “dry” formula suspended in a liquid carrier. As noted above, formula lacks immunological proteins. As such, the protein factors can be added to reach levels found in preterm milk, as noted in the earlier examples. Lactation protein levels can be determined as provided in example 3, and one or more lactation proteins added as required to remediate low or deficient levels of one or more proteins, the banked milk should approximate the lactation protein properties of preterm milk.
In the preceding specification, all documents, acts, or information disclosed does not constitute an admission that the document, act, or information of any combination thereof was publicly available, known to the public, part of the general knowledge in the art, or was known to be relevant to solve any problem at the time of priority.
The disclosures of all publications cited above are expressly incorporated herein by reference, each in its entirety, to the same extent as if each were incorporated by reference individually.
While there has been described and illustrated specific embodiments of a method of supplementing breast milk, it will be apparent to those skilled in the art that variations and modifications are possible without deviating from the broad spirit and principle of the present invention. It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween. | Donor milk has become a standard of care for feeding preterm infants, particularly those with gestational ages of 34 weeks or less, whose mothers are not lactating or not producing sufficient milk quantities. However, prior to distribution, donor milk is required to undergo pasteurization, typically using the Holder method, which is believed to destroy immune proteins in the milk and denature many other proteins. Donor milk has been found to contain concentrations of chemokines, cytokines, and growth factors, evidencing the value of donor milk over formula. In light of the findings, donor milk is supplemented with chemokines, cytokines, and growth factors that are found to be lower in the donor milk as compared to mother's own milk. | 0 |
BACKGROUND OF THE INVENTION
This invention relates generally to promotional displays sometimes referred to as standees for advertising of movies, videos, events, products and services, and more particularly to an easy and quick, pre-assembled self-erecting display of corrugated fiberboard and solid paperboard or like materials.
A common use of display signs is to advertise a new product or service for entertainment throughout the country. A good example is a new release of movies or movies on video cassette where it is desired to have a striking display to catch the attention of the movie goer or movie renter. It has been found that the most effective set displays are those which have life size figures or if not depicting individual figures, having a floor standing display which reaches the eye level of an adult. The typical dimensions would be 30 inches (76.2 cm) in width and 6 feet (183 cm) in height. One of the difficulties of such a size display is that it exceeds the maximum dimensions allowed by most common carriers providing quick and economical service. A common restriction is that of having a combined girth and length of 84 inches (213.4 cm). A typical display of 30 inches (76.2 cm) by 72 inches (183 cm) greatly exceeds that limit. The net result has been that such life size displays need to be folded lengthwise for shipment.
We have found that it is not only important that a display be of sufficient size and foldable for transport, but that it be automatically erectable when it is removed from the shipping carton and not include any separate pieces which might be lost. A further requirement is that such displays be erected by untrained persons without the benefit of instructions.
Previously, there has been some use of elastic bands in these type of displays in an attempt to create an easier and more rapid assembly process. This use has been limited to just folding of the easel wings and little or no attempt to incorporate other aspects of the display design, particularly multiple levels or curved dimensional surfaces. In most of these cases the display would simply be a single flat display panel with the easel piece previously glued to the back. A variety of perimeter contours and slight dimension effects have been attempted with limited success in achieving interesting and appealing designs. To create a greater dimensional look, additional panels would usually be shipped along and have to be attached at the retail store, which is undesirable as mentioned earlier.
Knockdown folding scores on the display panel and easel, necessary to collapse the display for shipment, must be in an aligned position and can create binding and fracturing at these points. This creates a damaged line across the face of the display panel and is very undesirable for the advertiser as well as for the retailer. Thinner material such as paperboard have been used to help alleviate the stress imposed on these knockdown scores, but without being braced by a curve or fold, these flat panels are weak, tending to warp, false crease, or dog-ear.
In addition, these previous displays have been very limited in size, both in width and in height. This is largely due to the need of fewer knockdown folding scores to minimize the distractive effect of the fractured fold lines. The larger the overall display panel, the more knockdown folding scores necessary to collapse the display down to a size, which is standard in the shipping of these types of displays.
A type of self-erecting display device is shown in the Herlin U.S. Pat. No. 4,773,622. In this case, a stand-up panel is erected by being pinched between adjacent side walls of a hexagonal structure, which pops open with the help of an elastic device. This system relies on the rigidity of an unbraced stand-up panel and a somewhat bulky base structure. This works well for a counter top display, but would substantially limit the size of a floor standing unit. Such a unit would take an excessive amount of floor area, require excessive material, and still have a floppy (unbraced) display panel.
In the Smith U.S. Pat. Nos. 4,493,424 and Re. 32,668, are disclosed display stands which are intended to contain product and open from a collapsed position. The back panel incorporates an upper display panel area, but it relies on the side panels for support and is substantially unbraced at its upper portions. An elastic element is used to open up the structure, but the box-type structure is limited in its adaptability. Also, these prior configurations do not have the ability to adapt to irregular graphic shapes or include multiple contoured panels needed to create an image having a substantial visual impact.
Accordingly, several objects and advantages of the invention are:
(a) to provide a one-piece display which will insure a complete and correctly assembled unit;
(b) to provide an easy, self-erecting display which sets up quickly (1 or 2 seconds);
(c) to provide a display which can have several contoured panels in a multitude of levels;
(d) to provide a self-erecting display which has single or compound curved surfaces for the main display panel;
(e) to provide a self-erecting display which is full sized (maximum video promotion format);
(f) to provide a display which has a knockdown folding score arrangement that allows for unfractured fold lines;
(g) to provide a self-erecting display which has a structurally sophisticated and interesting design to attract attention at the retail store;
(h) to provide a display which does not warp, false crease, or dog-ear under normal conditions;
(i) to provide an easel backed display which can have an irregular perimeter shape without affecting structure;
(j) to provide an easel backed display which minimizes consumption of valuable floor area in the retail store.
Further objects and advantages of the invention will become apparent from a consideration of the drawings and ensuing description.
SUMMARY OF THE INVENTION
The pre-assembled display device of the present invention is of corrugated paper or the like and is foldable for transport to a size acceptable to most parcel carriers and is capable of quick and easy erection by relatively untrained personnel upon removal from a shipping carton. One embodiment of the invention includes a rear display panel and a front display panel, both printed with graphic images and an easel member which is fastened in part to the back side of the rear display panel. An edge of the rear display panel is attached to hinged panels of the easel member. Resilient members such as rubber bands are connected across a vertical fold of the easel member. This causes a wing panel of the easel member to fold rearward for support means and is limited at approximately ninety degrees by a stop panel. This motion will simultaneously force the hinged panel and the edge of the rear display panel forward to create a concave configuration. The rear display panel has a slot therein through which another part of the wing panel passes and is fastened to the back side of the front display panel and pushes the front display panel forwardly away from the rear display panel.
Additional hinged panels from the easel member urged by resilient means another portion of the rear display panel away from the easel member, thus causing a portion of the rear display panel to also assume a convex configuration. The other vertical edge of the rear display panel is attached to a forwardly projecting part of a reverse folded second swing panel of the easel member, inversely causing this second wing panel to unfold rearward also for support means. This motion is limited by a cut out panel connected across the vertical fold of the second wing panel.
A second embodiment also includes a rear display panel, a front display panel and an easel member which is fastened in part to the back side of the rear display panel. The rear display panel has a slot therein through which a part of the easel member passes and is fastened to the back side of the front display panel. A wing panel of the easel member is folded back against the part of the easel member that is attached to the rear display panel. Resilient members are connected across a vertical fold of the easel member to a part of the rear display panel and the wing panel of the easel member. This causes the wing panel of the easel member to unfold rearward for support means and simultaneously causing the cut out panel of the easel member to push the front display panel forwardly away from the rear display panel. Both these embodiments include one or more horizontal folds permitting the entire display to be folded over to reduce its size for shipping.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of one embodiment of the invention;
FIG. 2 is a perspective view of the device of FIG. 1 folded in readiness for packing.
FIG. 3 is a view from one end of the device of FIG. 1 as taken along line 3--3 of FIG. 1;
FIG. 4 is a top view of the device of FIG. 1 as taken along line 4--4 of FIG. 1;
FIG. 5 is a fragmentary perspective drawing of a fold stop panel forming a part of the device of FIG. 1;
FIG. 6 is a plan view of the easel member of FIGS. 1-4 prior to folding;
FIG. 7 is a fragmentary perspective drawing showing details of an interconnection forming part of the embodiment of FIG. 1.
FIG. 8 is a fragmentary perspective view of another interconnection forming part of the embodiment of FIG. 1; and
FIG. 9 is a fragmentary perspective view of an additional interconnection arrangement used in the embodiment of FIG. 1.
FIG. 10 is a rear plan view of the device of FIG. 1.
FIG. 11 is a perspective view of another embodiment of the invention;
FIG. 12 is a perspective view of the device of FIG. 11 folded for packing;
FIG. 13 is a view from one end of the device of FIG. 11 taken along line 13--13 of FIG. 11;
FIG. 14 is a top view of the device of FIG. 11 taken along line 14--14 of FIG. 11.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, a display device 10 is shown in erected form including a front display panel 12 which in this case is a human figure, a rear display panel 14 and an easel member 16. All of these parts may be of a planar material such as corrugated paper or the like. In the specific case of FIG. 1, the rear display panel 14 is of a paperboard material. Display device 10 which when erected is approximately six feet high, is designed such that it can first be folded flat and second, be folded into four separate panels at fold lines 18, 20 and 22. As is apparent from the drawing, the front display panel is displaced forwardly of the rear display panel, forward being toward the direction from which the graphic image is viewed and opposite the rearwardly projecting easel member 16. The rear display panel 14 is forced into a curved configuration, and the easel member 16 folds toward the rear to provide support for the display device 10. When it is desired to pack and ship the device 10, it is first folded such that it is essentially flat and is then folded along lines 18, 20 and 22 of rear display panel 14, lines 18', 20' and 22' of easel member 16 and corresponding fold lines of front display panel 12 to a configuration essentially like that shown in FIG. 2. It is apparent from FIG. 2 that the device 10 may from the position shown be pushed together such that it essentially consists of multiple layers of corrugated paper and paperboard for packing in a flat box. It will be clear that the layers on the outside (fold lines 18', 20' and 22') must be formed with parallel creases or otherwise relieved to permit the device 10 to fold flat.
FIG. 3 is a view of the end of the device of FIG. 1 as taken along line 3--3. In this view the curved rear display panel 14 may be seen to include a plurality of foldover panels 24, 26, 28 and 30 which fold over and are secured to a wing panel 16A of the easel member 16. Panels 24 and 30 are preferably glued or cemented to wing panel 16A. Panels 26 and 28 include slots 32 and 34, respectively, through which are inserted tabs 36 and 38 cut out of wing panel 16A and which fold under slots 40 and 42 in wing panel 16A. Attachment of the foldover panels 26 and 28 of rear display panel 14 by means of the tabs 36 and 38 and the elongated slots 32 and 34 provides flexibility so that some relative movement of the tabs relative to the slots is available during folding of the display device 10.
Wing panel 16A also includes two additional cut out panels 44 and 46 which bridge across the fold line 48 between wing panel 16A and the remaining part of easel member 16 which includes openings into which cut out panels 44 and 46 are inserted. This detail is shown in FIG. 5 in which fragmentary parts of easel member 16 and wing panel 16A are shown. It can be seen that, prior to folding on fold line 48, cut out panel 44 was cut out including vertically extending projections 44A and 44B which, after folding at fold line 48 are inserted through an opening 50 in easel member 16 with projections 44A and 44B being extended to limit the angle at which wing panel 16A may be folded away from easel member 16. Cut out panel 46 is identical and is also inserted through an opening in easel member 16 to limit movement of wing panel 16A.
FIG. 4 is a view from the top of the display device of FIG. 1 including front display panel 12, rear display panel 14, easel member 16, and wing panel 16A. Panel 24 is visible where it is attached to wing panel 16A and also cut out panel 44 which bridges across fold 48 and latches behind easel member 16.
Note that portions of wing panel 16A extend beyond fold 48 and that panel 24 does not fold over the end of easel member 16 at fold line 48 but folds over the end of the part of wing panel 16A which extends forward of fold line 48.
At its opposite end, easel member 16 has a fold line 52 with a major portion of a wing panel 16B extending essentially perpendicular to the remainder of easel member 16 such that it acts as a support for the display device 10. Wing panel 16B is pulled into a perpendicular position by means of a pair of rubber bands, one of which is shown at numeral 54, and both of which are anchored at points on wing panel 16B outwardly of fold line 52 and at points on easel member 16 considerably toward its center from fold line 52. A stop panel 104 includes a notch through which rubber band 54 passes, holding panel 104 perpendicular to wing panel 16B and preventing wing panel 16B from being pulled beyond the desired position by rubber band 54.
Extending on the opposite side of fold 52 are cut-out panels from wing panel 16B including a member 56 which extends through a slot in rear display panel 14 and is attached to the front display panel 12. Also extending from wing panel 16B and angled from a second fold line 58 are a number of extensions, one of which panel 60 is shown attached to a fold over panel 62 on the right hand edge of rear display panel 14. Other such extensions attached to portions of rear display panel 14 are in vertical alignment with panel 60 and are discussed below.
Attached to the back of front display panel 12 is a foldable brace 64 of corrugated paper which passes through slots in rear display panel 14 and easel member 16 and is folded over and tucked under a flap 66 cut out of easel member 16. Another such brace is in vertical alignment with brace 64.
A cut out flap 68 from easel member 16 is folded outwardly by the force of a rubber band 70 to push against the back side of rear display panel 14 causing it to curve forward and an additional stop panel 72 folds over flap 68 and serves as a stop, preventing flap 68 from folding back against the surface of easel member 16 under the force of the rubber band 70. Two or more such combinations such as flap 68, rubber band 70, and stop panel 72 may be used as required. Before the display can be folded, any such flap 68 must be manually folded back into easel member 16 thereby releasing flap 72 to be pulled toward the plane of easel member 16 by rubber band 70.
At the time the display device 10 is folded for packing, the rearwardly extending portion of wing panel 16B is rotated clockwise around fold line 52, stretching rubber band 54 and causing front display panel 12 to be displaced to the left and flat against rear display panel 14. This causes fold line 58 to be rotated to the left and folding wing panel 16B directly against hinged panel 60 and other panels in vertical alignment with panel 60. At the same time wing panel 16A is rotated clockwise around fold line 48 which pulls rear display panel 14 flat against easel member 16. Rear display panel 14 is attached to easel member 16 at vertically aligned points located to achieve the desired curve.
FIG. 6 is a plan view of the easel member 16 of FIGS. 1-4 prior to folding. In this view internal lines shown as solid lines are cuts through the corrugated sheet and the dashed lines indicate fold lines. The major vertical fold lines 48 and 52 are shown which separate wing panels 16A and 16B respectively from the main part of easel member 16. Cut lines 130, 132 and 134 define a series of cut-out panels which extend forwardly of easel members 16 when wing panel 16A is folded toward the back as shown in FIG. 4. Hinged panels 60, 61 and 63 as well as cut out panels 56 and 57 which are inside the periphery of panels 60 and 63, respectively, all fold forward as wing panel 16B folds around fold line 52 ninety degrees to the rear. Cut out panels 56 and 57 extend forwardly as shown in FIG. 4 and are folded at the end as shown with the end portion glued or cemented to the back of front panel 12. Panels 60, 61 and 63 are again folded on fold line 58 such that they are angled approximately forty-five degrees from forward as shown on FIG. 4.
Cut out flap 68 is folded forwardly on line 20' and panel 72 is folded forwardly across flap 68 such as to prevent flap 68 from moving past a position essentially perpendicular to easel member 16. A rubber band 70, not shown in this view, extends between notches in flap 68 and an anchor 69. Flap 68 extends forwardly and urges rear display panel 14 into the curved contour shown in FIGS. 1, 3 and 4. Similar forwardly extending cut out flaps 118 and 120 may be used in the same way as flap 68 if it appears that more is required to cause rear display panel 14 to assume the desired contour. Anchors 75 and 77 provide means for attachment of additional rubber bands between the notches on flaps 118 and 120 and anchors 75 and 77, respectively. Additional flaps like panel 72 can be cut out to provide the corresponding function for flaps 118 and 120 as panel 72 provides for flap 68, if needed.
An anchor 81 in wing panel 16B cooperates with an anchor 100 in the surface of easel member 16 to locate a rubber band which also passes through a notch in panel 104 to hold panel 104 folded downwardly (to the rear). A similar pair of anchors 102 and 103 support another rubber band extending across panel 106. Panels 104 and 106 which are adjacent fold 52 prevent wing panel 16A from being pulled past the desired position essentially perpendicular to the plane of easel member 16, as shown in FIG. 4.
Positioned just below anchor 100 is a small cut out flap 66 which cooperates with an adjacent slot 108 to receive the foldable brace 64 attached to the back of front display panel 12. Brace 64 passes through a slot in member 14, slot 108 and folds under flap 66. Just above anchor 102 is another small flap 110 cooperating with an adjacent slot 112 to receive another foldable brace attached to the back of front display panel 12.
FIGS. 7, 8 and 9 are fragmentary perspective views of certain details of the structure of FIGS. 1-6. FIG. 7 shows a portion of wing panel 16B including horizontal fold line 18 and vertical fold lines 52 and 58. A part of hinged panel 60 extends forwardly and is angled beyond fold line 58 and is fastened to fold over panel 62. A member 56 of wing panel 16B which is in the same plane as the rearwardly extending part of wing panel 16B is shown extending through a slot 122 in rear display panel 14. Also shown in FIG. 7 is anchor 81 to which rubber band 54 is anchored and a portion of fold over panel 78.
FIG. 8 is a fragmentary perspective views of a portion of the display device 10 including part of wing panel 16B, hinged panel 74 and portions of fold over panels 78 and 80, which are secured to hinged panel 74 by inserting cut out flaps 82 and 84 through slots 86 and 88 respectively. Also shown are horizontal fold line 20' and vertical fold line 58.
FIG. 9 is a fragmentary perspective view of a portion of the display device 10 including parts of rear display panel 14, front display panel 12, wing panel 16B and member 56 which passes through a slot 122 in rear display panel 14 and is secured to the back of front display panel 12. Fold line 58 is shown with parts of extension 60.
FIG. 10 is a rear plan view of the display device 10. Most of what is seen consists of easel member 16 including wing panels 16A and 16B including several cut out portions of each. At the top of wing panel 16A is panel 24 which is fastened to wing panel 16A. Below panel 24 is a second, somewhat narrower panel 26 secured to wing panel 16A by means of cut out flap 36 which enters a slot 32 and is folded over and tucked under a slot 40. A similar panel 28 is secured to wing panel 16A using a similar cut out flap 38 which passes through slot 34 and is folded over and tucked under slot 42. Panel 30 is fastened to wing panel 16A in the same manner as is panel 24. Fold line 48 being inbound or to the left of the outer edge of panels 24 and 30, forward extensions of wing panel 16A support panels 24 and 30 and an extension 31 supports panels 26 and 28.
In this view, one sees only the edge of the portion of wing panel 16B which extends to the rear. Also fold lines 52 and 58 are in alignment with member 56 which attaches to front display panel 12. A similar member 57 is also in alignment with and is part of wing panel 16B and is attached to front display panel 12 near the bottom. From fold line 58 and directed forwardly at an angle are hinged panel 60 to which fold over panel 62 is attached and vertically aligned panels 61 and 63. Fold over panels 78 and 80 are attached to panel 61 by means of cut out flaps 82 and 84 which enter slots 86 and 88, respectively and are tucked under slots 90 and 92 in the same manner as described with respect to cut out flaps 36 and 38. Panel 94 is fastened (cemented) to extension 63.
Wing panel 16B includes two small cut out anchors 81 and 103 (see FIG. 6) which serve to anchor one part of each of rubber bands 54 and 55. The opposite ends of rubber bands 54 and 55 are anchored on easel member 16 at anchors 100 and 102 respectively. Adjacent wing panel 16B are panels 104 and 106 which are notched to receive rubber bands 54 and 55 which thereby hold panels 104 and 106 perpendicular to wing panel 16B and thereby prevent wing panel 16B from being pulled past the desired position.
An end of brace 64 from front display panel 12 passes through a slot 108 and is tucked under cut out flap 66 of easel member 16. A second such brace 65 from front display panel 12 passes through a similar slot 112 and is tucked under a cut out flap 110.
Cut out flap 68 is hinged on fold line 20 and includes notches to receive one end of a rubber band 70 as shown on FIG. 6. Flap 68 is restrained from moving above fold line 20 by means of stop panel 72 which is hinged such that it swings over the top of cut out flap 68 and restrains it from being pulled further upward by rubber band 70 which is anchored on easel member 16 by means of anchor 69. Additional cut out flaps 118 and 120 with accompanying rubber bands are located in vertical alignment with flap 68. Applicant has found that one stop flap 72 is adequate to keep flaps 68, 118 and 120 from collapsing under the tension caused by flexing of rear display panel 14.
FIG. 11 is a perspective view of a second embodiment of my invention which also provides a display having three dimensional characteristics and which, although it can be made six feet tall or more, is foldable to be placed into a carton having a major dimensions only slightly greater than half the height of the erected display. In this embodiment, a rear display panel 170 contains on its front surface, desired display material and is foldable at a fold line 172. Located behind rear display panel 170 is an easel member 174 which is, in part, cemented or otherwise secured to the back of rear display panel 170. A front display panel consists of a lower part 176 and an overlapping upper part 138, each of which is fastened to a part of easel member 174.
FIG. 12 is a view of the display device of FIG. 10 partially folded for packing. In this view it will be apparent that the front display panel parts 176 and 138 are separated when rear display panel 170 and easel member 174 are folded together. When these members are pushed together they make a flat assembly having essentially the thickness of several layers of corrugated paper, which is easily placed in a carton for shipping or storage.
FIG. 13 is a view from the left side of the display device of FIG. 10 and shows rear display panel 170, upper part 138 and lower part 176 of the front display panel and the easel member 174. Visible in this view are a number of forwardly extending parts 140, 142, 144, 146 and 148 of easel member 174. Parts 140 and 142 are fastened to upper part 138 and parts 144,146 and 148 are fastened to the lower part 176 of the front display panel. A dashed line indicates fold line 172 of easel member 174 which is at essentially the same location as on rear display panel 170.
FIG. 14 is a view from the top of the display device of FIG. 10 and shows, among other things, edge views of rear display panel 170, upper part 138 and lower part 176 of the front display panel, and easel member 174 which includes a vertical fold line 150 for its entire height including a panel 174A which is fastened to the back of rear display panel 170. Various parts of easel member 174 are formed of cut outs and folded extensions which are fastened to front display panel parts 176 and 138. Extensions of easel member 174 which extend through slots in rear display panel 170 include fold parts 140 and 146, of which part 140 is visible, part 146 being directly below it. Additional foldover extensions 142, 144 and 148 are attached to the front display panel parts; extension 142 being attached to the upper panel 138 and extensions 144 and 148 being attached to lower panel 176.
A rubber band 152 extends between anchors on fold part 140 adjacent upper front display panel member 138 and a non folded extension of easel panel 174A. Also extending from easel panel 174A is a cut out panel 154 which has upper and lower extending projections 156, 158 (see FIG. 13) and which extends through a slot 160 in easel member 174. Thus cut out 154 serves to limit the rotation of member 174 such that it is not pulled past the desired position essentially perpendicular to front display panels 176 and 138 and is essentially like that shown in FIG. 5. A similar rubber band and anchors therefore may extend between fold part 146 and another non-folded extension of easel panel 174A.
When it is desired to fold the embodiment of FIGS. 11-14 for shipping, easel part 174 is rotated clockwise (as seen in FIG. 14) against panel 174A stretching rubber band 154 and causing members 176 and 138 to fold back against rear display panel 170. Rear display panel 170 and each part of member 174 then fold over on line 172, assuming the configuration shown in FIG. 12.
Accordingly, the reader will see that the one-piece, self-erecting display of this invention can be easily and quickly set up and provide an interesting design with irregular shapes and several dimensional levels. In addition, the display can be the full size of the promotional video standee standard without additional floor space and without fractured fold lines, warping, false creasing, or dog-eared corners.
While the above description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of some of the preferred embodiments of the invention. For example:
(a) the orientation of the curve of the rear display panel may be reversed;
(b) any display panel shown may be composed of two or more pieces taped or glued together as a solution to some printing or die cutting machine limitations;
(c) the curved display panel may be a single curve having one of the types of easel mechanisms on both sides of the display, creating either a simple convex or concave curved panel;
(d) the rear display panel may be made of a rigid planar material in which angular configurations could would be achieved;
(e) the rear display panel may include areas in which the easel member is exposed and presenting a graphic image;
(f) additional panels of various shape can be positioned at different levels;
(g) any additional display panels may be composed of two or more separate pieces in order to eliminate fold lines;
(h) the display can be produced in smaller versions for use on counter tops or display shelving;
(i) additional raised panels (usually smaller), can be attached to the display by a thickness of foam tape or like device as to provide a popped out title card, photographic stills, graphic shapes, advertising copy, etc.
(j) horizontally oriented cut out flaps may be attached to the front display panel which automatically push it forward when the display is unfolded.
While only two embodiments have been shown and described herein, it will be recognized by those skilled in the art that many modifications are possible and I do not desire to be limited other than by the scope of the attached claims and their equivalents. | A pre-assembled self-erecting display of corrugated paper or the like includes a rear display panel, a front display panel and an easel member which is fastened in part to the back side of the rear display panel. Resilient members such as rubber bands are connected across a vertical fold of the easel member. This causes a wing panel of the easel member to fold rearward for support means and an edge of the rear display panel to fold forward to create a concave configuration. Hinged panels folding out of the easel member urge an inner portion of the rear display panel away from the easel member, thus causing the rear display panel to obtain a convex configuration. The other edge of the rear display panel is attached to a part of a second wing panel of the easel member, inversely causing it to unfold rearward, also for support means. A part of the easel member passes through a slot in the rear display panel and is fastened to the back side of the front display panel, thus causing a multiple level configuration. Included are one or more horizontal folds permitting the entire display to be folded over to reduce its size for shipping. | 6 |
CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. provisional application 60/553,927 filed Mar. 17, 2004.
FIELD OF THE INVENTION
This invention relates to a lightweight, composite air intake manifold for internal combustion engines and a method for making it.
BACKGROUND OF THE INVENTION
A need exists for lightweight intake manifolds for internal combustion engines capable of withstanding significant internal pressures. Many prior art intake manifolds have been fashioned from cast aluminum which, for a typical four cylinder internal combustion engine, may weigh approximately 15 pounds and may act to heat the intake air charge, adversely affecting performance. Moreover, there is a need for internal combustion engine intake manifolds having internal passages shaped and sized for efficient air flow. What is needed is a lightweight, high strength, low thermal mass intake manifold having internal passage geometry adapted to facilitate air flow and a method for making such an intake manifold.
BRIEF DESCRIPTION OF THE INVENTION
In an embodiment of the present invention the aforementioned need is addressed by providing a lightweight composite air intake manifold and a method for making such a manifold which allows the manifold designer to optimize the internal passage geometry for efficient air flow. A composite air intake manifold of the present invention includes a header and runners having communicating passages. The composite intake manifold is fashioned from resin impregnated carbon fiber cloth which is preferably impregnated and cured between a meltable core mold and a split outside mold. The carbon fiber cloth is oriented throughout the manifold to give the manifold maximum pressure resisting capability with minimum thickness and weight. Because virtually any shape may be adopted for the interior passages of the header and the runners, the interior passages of the header and runners may be shaped to enhance air flow through the manifold.
The method for making the present air intake manifold preferably employs at least two complementary outside mold portions having inside surfaces corresponding to the desired outside surface of the manifold and a core mold having an outside surface corresponding to the desired inside surfaces of the internal manifold passages. The outside mold is preferably made from a durable material for repeated use. The core mold is preferably made from a meltable material such as for example a wax composition that is substantially impermeable to a thermosetting resin. It is important that the core mold material have a melting point that is above the temperature at which the thermosetting resin selected for the manifold cures and that is also below the temperature at which the selected resin begins to degrade after it has been cured.
The manifold is laid up by first placing portions of structural fiber cloth around the core mold. A spray adhesive may be used to position fiber cloth portions upon the complex curved outer surfaces of the core mold. Any appropriate fabric, such as carbon fiber fabric, fiber glass fabric or even ceramic fiber fabric may be used. The outside molds are closed around the fabric covered core mold. After the lay-up is assembled, liquid resin is transferred into the dry structural fabric through holes or channels in at least one of the outer molds. A resin and core mold material combination is selected such that the resin can be cured at a temperature below the melting point of the core mold material. After the resin is cured, the manifold is heated until the core mold material melts and drains out. As stated above, a core mold material and resin combination is selected such that the core mold material may be melted away without degrading the cured resin. A solvent may be used to wash out any remaining core mold material. Fittings for interfacing with other engine components may then be added to the manifold using appropriate adhesives. Alternatively, the fittings may be molded into the manifold if geometry permits. The resulting manifold is very light, may have excellent internal geometry for conducting air flow and may be very strong for resisting high internal pressures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a perspective view of a composite intake manifold.
FIG. 1B is a side view of a composite intake manifold
FIG. 2 is an exploded view the molds needed to lay-up a composite intake manifold body including two outer mold pieces and a core mold.
FIG. 3A is an plan view of a first fabric portion used to cover a runner.
FIG. 3B is an plan view of a second fabric portion used to cover the header.
FIG. 3C is an plan view of a third fabric portion used to cover the header having edges for forming seams that are spaced away from the seams formed by the second fabric portion.
FIG. 3D is an plan view of a fourth fabric portion used to cover the header having edges for forming seams that are spaced away from the seams formed by the second and third fabric portions.
DETAILED DESCRIPTION
Referring to the drawings, FIGS. 1A and 1B illustrates a composite intake manifold 10 . The composite intake manifold 10 includes a manifold body 10 A which further includes a header 12 and, in this example, four runners 14 A, 14 B, 14 C and 14 D extending from the body of header 12 . Each of runners 14 A, 14 B, 14 C and 14 D provides an outlet port. Runners 14 A, 14 B, 14 C and 14 D are bonded to an aluminum outlet fitting 15 A for mating with the intake ports of the cylinders of an internal combustion engine 300 shown in FIG. 1B . Header 12 includes an inlet opening 12 A around which is bonded an inlet fitting 12 B for mating with the outlet fitting of an air supply 200 shown in FIG. 1B or other source of air. A second aluminum fitting 12 C is also glued to header 12 . Header 12 and runners 14 A, 14 B, 14 C and 14 D of intake manifold body 10 A are integrally formed with resin impregnated high strength fabric. The method for fabricating intake manifold body 10 A will be described in greater detail below. As can be seen in FIG. 2 , intake manifold body 10 A is relatively thin walled. Because intake manifold body 10 A is relatively thin walled and fabricated from a high strength lightweight composite material, intake manifold 10 with bonded aluminum fittings 12 B, 12 C and 15 A has a weight that is approximately 30% of the weight of a traditional cast aluminum intake manifold. Intake manifold body 10 A may also have internal passages which may be advantageously shaped to facilitate air flow.
FIG. 2 presents an exploded isometric view of outside molds 102 and 104 as well as core mold 110 for fashioning an intake manifold body 10 A. As can be seen in FIG. 2 , lay-up 100 includes a first outside mold 102 , a second compatible outside mold 104 and a core mold 110 . First and second outside molds 102 and 104 fit together in a clam shell fashion. First and second outside molds 102 and 104 are fashioned from a durable, reusable material. First outside mold 102 includes a mold impression 102 A which is offset from the outside surface of core mold 110 . Similarly, second outside mold 104 includes a corresponding mold impression (not shown) which is offset from the opposite outside surface of core mold 110 . The impressions of outside molds 102 and 104 define a surface that is offset from the outside surface of core mold 110 . These impressions are suitable for forming the outside surface of manifold body 10 A. This degree of offset is generally related to the desired thickness of manifold body 10 A. Second outside mold 104 is shown in FIG. 2 to include a resin inlet port for receiving resin and conveying it to the interior impressions of mated first and second outside molds 102 and 104 . Core mold 110 is preferably fashioned from an expendable wax material which will be described in greater detail below. Core mold 110 includes a header portion 112 for forming header the inside surfaces of header 12 and runner portions 114 A, 114 B, 114 C and 114 D for forming the inside surfaces of runners 14 A, 14 B, 14 C and 14 D.
FIGS. 3A–3D illustrate first, second and third structural fabric portions 132 , 134 and 136 for covering core mold 110 . First structural fabric portion 132 shown in FIG. 3A is tube shaped and has a weave pattern having fibers oriented approximately 45 degrees to its central axis. This weave pattern allows for easy diametrical adjustment as a first fabric portion is placed around one of runner portions 114 A, 114 B, 114 C and 114 D. Although only one first fabric portion 132 is shown in FIG. 3A , at least four and more likely some multiple of four such first fabric portions will be used to cover of runner portions 114 A, 114 B, 114 C and 114 D. Second, third and fourth fabric portions 134 , 136 and 138 shown in FIGS. 3B–3D are for covering header portion 112 . Second fabric portion 134 includes corresponding edge openings 134 A, 134 B, 134 C and 134 D for clearing runner portions 114 A, 114 B, 114 C and 114 D as second fabric portion 134 is wrapped around header portion 112 of core mold 102 . Similarly, third fabric portion 136 shown in FIG. 3C includes openings 136 A, 1136 B, 136 C and 136 D for receiving runner portions 114 A, 114 B, 114 C and 114 D. Fourth fabric portion 138 shown in FIG. 3D also has a series of openings 138 A, 138 B, 138 C and 1138 D for receiving runner portions 114 A, 114 B, 114 C and 114 D of core mold 110 . However, the openings in fabric portion 138 have been offset so that the edges of fabric portion 138 will join at a different location on core mold 110 thus forming a seam at a different location than that formed by third fabric portion 136 . With the use of such offset openings, seams may be placed in other locations around header portion 112 of core mold 110 . This layering of seams with areas of fabric having no seams increases the strength of the resulting manifold body 10 A. The fabric portions shown in FIGS. 3A–3C are intended to be merely examples of the types of structural fabric patterns used to lay-up manifold body 10 A. The fabric portions described above may be applied in multiple plies to achieve a required capability for withstanding internal pressure.
The structural fabric portions described above may, for example, be fashioned from an aramid fiber such as du Pont KEVLAR® fiber or may, for example, be fashioned from fiber glass, carbon fiber or even ceramic fiber for advantageous thermal properties. Multiple layers of first structural fabric portions 132 may be laid up on each runner portion of core mold 110 and multiple layers of second, third and fourth fabric portions 134 , 136 and 138 or other structural fabric portions having various offset opening locations for staggering the locations of seams may be laid up around core mold 110 . The number and type of fabric portions would depend on the intended operating environment and conditions of manifold 10 . For example, a high pressure manifold would require a larger number of layers of structural fabric. Because temperatures in an engine compartment may often exceed 150° F., a resin may be selected which is capable of resisting relatively high temperatures above 150° F. In the alternative, pre-impregnated sheets of structural cloth may be used. The resin present in such pre-impregnated cloth should have a curing temperature below the melting temperature of the core mold material and a degradation temperature above the melting temperature of the core mold material.
The process of laying up manifold body 10 A can be understood by referring to FIG. 2 . FIG. 2 is a perspective view showing outside molds 102 and 104 and core mold 110 used for making an intake manifold body 10 A according to the method of this invention. To conduct the process for making manifold body 10 A, the following components are needed: (1) a first outside mold 102 , (2) a second complementary outside mold 104 , (2) a core mold 110 and (3) at least four fabric portions 132 and at least a combination of fabric portions including at least two of fabric portions 134 , 136 and 138 . Fabric portions 132 , 134 , 136 and 138 may all be fashioned from a dry, unimpregnated structural fiber fabric. In the alternative, some or all of them may be fashioned from structural cloth which is pre-impregnated with resin.
The applicant has found that the best core mold material for both first core mold 110 is a wax composition that is formulated to melt at a temperature above 160° F. Those skilled in the art can formulate a wax having a desired melting point. A supplier of industrial waxes such as Calwax, Inc. of Irwindale, Calif. can easily supply a wax composition having a desired melting point. For example, a wax composition consisting of 40 parts Calwax 126™ wax, 60 parts Calwax 252B™ wax and 1 part Calwax 320™ wax obtained from Calwax, Inc. will melt above 160° F. Ceramic micro-spheres or some other similar material can be added to the core mold composition to reduce thermal expansion effects at the curing temperature of the resin, to reinforce the core material structurally and to even reduce the weight of the core material. The addition of ceramic micro-spheres also makes it possible to compose core mold materials having such favorable thermal expansion characteristics that parts with larger internal volumes can be produced while maintaining the overall shape of the part within exact tolerances. Such space filling materials would also decrease the amount of heat needed to melt a volume of core mold wax. It is generally advantageous to reduce the thermal expansion effects associated with the core mold material.
The process for making manifold body 10 A includes a lay-up process, a resin impregnation step, a curing step and a core mold drain step. The process laying up manifold body 10 A shown in FIGS. 1A and 1B includes the following steps: (1) Structural fabric portions 132 , 134 , 136 and 138 are laid up around core mold 110 . A spray adhesive may be used to force the structural fabric portions to adhere to the complex curved surfaces of core mold 110 . (2) Core mold 110 with laid up fabric is placed between outside molds 102 and 104 which are then clamped tightly together. (3) Low viscosity resin is introduced into a resin entry port 104 A in one of the outside molds. (4) In the case of a resin used in combination with carbon fiber fabric, a typical curing temperature would be about 130° F. An isothermal transfer process may be conducted where heated resin is transferred, via pressure or vacuum or a combination of pressure and vacuum, into a heated lay-up at the resin curing temperature. However, an isothermal transfer process must be conducted rapidly so that resin flows into the layers of the lay-up before it begins to harden.
After the resin is cured, outer molds 102 and 104 are separated from manifold body 10 A. At this point, the core mold material can be melted and drained from manifold body 10 A. This is accomplished by heating the manifold body to a temperature which is above the melting point of the core mold material but below the point at which the cured resin of manifold body 10 A will degrade. The preferred wax composition described above can be melted efficiently at approximately 250° F. which is well below the temperature at which many resin resins will degrade. The melted core mold material can be recovered for future use. Core mold material residue can also be washed out with a solvent that will dissolve the core mold material but that will not attack the resin or carbon fiber material of the composite. What remains is a is an unfinished manifold body 10 A having excess material. After appropriate trimming of the excess material from manifold body 10 A, aluminum fittings 12 B, 12 C and 15 A may be glued to manifold body 10 A using a high strength adhesive, suitable for the application, thus completing intake manifold 10 .
It is to be understood that while certain forms of this invention have been illustrated and described, it is not limited thereto, except in so far as such limitations are included in the following claims and allowable equivalents thereof. | A composite air intake manifold includes a header and runners having communicating passages. The composite intake manifold is fashioned from carbon fiber cloth which is preferably impregnated with resin and cured between a meltable core mold and a split outside mold. The carbon fiber cloth is oriented throughout the manifold to give the manifold maximum pressure resisting capability with minimum thickness and weight. Because virtually any shape may be adopted for the interior passages of the header and the runners, the interior passages of the header and runners may be shaped to enhance air flow through the manifold. | 5 |
BACKGROUND OF THE INVENTION
[0001] This invention relates to the heat treatment of cutting tools, in particular, although not necessarily exclusively, the heat treatment of cutting tools such as twist drills having a shank and a cutting portion to which it is desired to impart different hardness.
BACKGROUND ART
[0002] Cutting tools such as twist drills, milling tools, reamers, countersinks and the like include a cutting portion, formed with a number of cutting edges, and a shank by which the tool is held, for example in a collet chuck or other holder of for example a lathe, machine drill or hand drill. It is common practice to harden the cutting portion of these tools in order that they can cut efficiently. However, it is undesirable to harden the shanks to the same degree, because a relatively soft shank is required if the chuck or other holder is to grip the tool securely.
[0003] These cutting tools are typically manufactured from steel, most usually a high-speed steel. The process by which they are hardened is a heat treatment process, in which blanks for the tools are heated up to a temperature of about 1150-1230° C., at which temperature they are held for a sufficient length of time to ensure that the blank is heated to its core. The blank is then rapidly cooled (i.e. quenched) to effect the change in microstructure that gives the steel its hardness. Hardening of other ferrous and non-ferrous metals can be achieved in a similar manner with suitable heat treatment regimes.
[0004] To give the desired differential hardening (fully hardened cutting portion/soft shank), the conventional approach is to use a salt bath for the heat treatment. The cutting portion of the tool is immersed in the liquid salt, which is held at the necessary high temperature. The shank remains clear of the bath and consequently remains at a temperature which is not sufficiently high for any appreciable hardening to occur.
[0005] The use of a salt bath in this way can reliably produce tools having the desired hardness characteristic, and is still the most common method of hardening used today. However, the process does have drawbacks, most notably the environmental and safety concerns associated with the toxic, extremely high-temperature molten salts used in the bath, which also give rise to difficult and unpleasant working conditions for the operator of the process.
[0006] More recently, it has been proposed to differentially harden cutting tools by treating them in a three-stage vacuum furnace, the tools progressing in a linear fashion through three chambers in the furnace. The tools are loaded in batches into the first chamber which is closed and then evacuated. After a predetermined amount of time, the batch of tools is then moved into the second chamber, which is already under vacuum, and which is held at a high temperature in order to heat the tools to the desired hardening temperature. Having been held in the heated chamber for an appropriate amount of time, the tools are then transferred to the third chamber. Here they are quenched by pumping nitrogen gas into the chamber under high pressure.
[0007] To achieve the desired differential cooling, the tools are held within the chambers of the furnace in carriers, in the form of large metal blocks formed with recesses in which the tool shanks are received. The carriers shield the shanks to some degree from the heated interior of the chamber. However, the temperature of the carriers themselves will increase, particularly where the heat treatment regime dictates that the tools must be held in the heating chamber for any significant length of time, possibly resulting in some unwanted hardening of the shanks. This problem can be exacerbated if the carriers are not allowed to cool sufficiently between batches of tools. The rapid cooling by blasting the tools with nitrogen may also lead to undesirable distortion.
[0008] Moreover, the furnace must be sealed from its surrounding environment, and within the furnace the three chambers must be separately sealed, in order that the necessary vacuum can be maintained, leading to a relatively complex and expensive design of furnace. It is perhaps for this reason that the salt bath still predominates, despite its drawbacks mentioned above.
SUMMARY OF THE INVENTION
[0009] The present invention has as its general aim the provision of heat treatment apparatus and methods for differentially hardening two portions of a cutting tool which offers an economic and reliable alternative to the conventional, and ever less desirable, salt baths.
[0010] In one aspect, the invention provides apparatus for heat treating a cutting tool, comprising a furnace within which there is at least one radiant heating element and a tool holder adapted to receive and shield a first portion of the tool from the heating element whilst a second portion of the tool is directly exposed to radiant heat from said element.
[0011] In another aspect, the invention provides a heat treatment method for hardening a metal tool, the method comprising directly exposing a first portion of the tool to a source of radiant heat in a furnace to raise the temperature of said first portion to an elevated temperature, and shielding a second portion of the tool from said source of radiant heat to maintain it at a temperature lower than the elevated temperature of said first portion.
[0012] The term “tool” used herein is intended to include blanks and semi-finished blanks for tools as well as finished tools themselves.
[0013] By exposing the tools directly to a source of radiant heat it has been found possible to accurately control the differential heating of the two portions of the tool.
[0014] This control is enhanced when, as is preferred, the radiant heat source is arranged to lie alongside the tools when they are being heated in the furnace. In this case, it may also be arranged that the heat source, i.e. the heating element, does not extend alongside or at most extends only partially alongside the tool holder in which a portion of the tool is shielded. This further exaggerates the differential heating of the two portions of the tool.
[0015] Another particularly preferred measure to increase the temperature differential between the two portions of the tools, is to actively cool the tool holder. For instance air, water or some other cooling fluid may be forced through or around the tool holder or some other heat conducting element that is thermally coupled to the tool holder, whereby heat can be drawn away from the holder.
[0016] It is of course more economical to treat batches of tools at one time, and for this reason the furnace may be arranged such that a plurality of tools can be simultaneously exposed to the heating element. For instance, a row or two-dimensional array of tools may be held in one or more tool holders adjacent the element. To ensure a more uniform heating of the tools, two heating elements may be arranged, one either side of the tools, for example to lie parallel with a row of tools. This principle can be extended to layouts including two or more rows or arrays of tools extending parallel to one another, these rows or arrays being held in tool holders within corridors defined between opposed heating elements, e.g. three rows of tools held in three parallel corridors defined by four heating elements.
[0017] Where the tools are treated in batches, it is particularly preferred that each tool is directly exposed to radiant heat from at least one heating element, without being shielded or partially shielded from that element by any of the other tools of the batch. Typically, with the configuration of heating elements described above, this will mean that the tool holders should be arranged to hold at most two parallel rows of tools. Even then, it is desirable to offset the rows from one another such that the tools are fully exposed to the heating element to one side of the batch and only partially shielded from the element to the other side of the batch.
[0018] The furnace preferably also includes means for rapidly cooling the tool or tools subsequent to exposure to the heating element(s). Particularly preferred for this purpose are one or more cooling elements adjacent which a row or array of tools can be disposed in a tool holder, much in the same way as they are held alongside the heating element. The cooling elements, which may for example be cooled themselves by a flow of water or other cooling fluid, absorb heat radiating from the tools to help prevent the atmosphere around the tools increasing significantly in temperature, encouraging rapid cooling of the tools.
[0019] Similar to the heating elements, parallel rows of cooling elements may be arranged within the furnace to define one or more corridors for the tools.
[0020] Conveniently, the furnace may be divided into a heating zone in which the tools are heated by radiant heat and a separate cooling zone in which the tools are cooled, transport means being provided to take the tools from one zone to the other. A particularly convenient form of furnace that can be adopted for this approach is a rotary hearth furnace, in which the tools are carried by a rotating support or hearth, e.g. in their tool holder, through an annular chamber, which may be sub-divided into different temperature zones.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] [0021]FIG. 1 is a part sectioned plan view of a rotary hearth furnace according to an embodiment of the present invention;
[0022] [0022]FIG. 2 is a section, on a slightly enlarged scale, along line II-II of FIG. 1;
[0023] [0023]FIG. 3 shows in cross-section, the heating zone of the furnace of FIG. 1;
[0024] [0024]FIG. 4 shows somewhat schematically, on an enlarged scale the central portion of the heating zone illustrated in FIG. 4;
[0025] [0025]FIG. 5 is a plan view of a tool carrier, on a much enlarged scale, for use in the furnace of FIG. 1;
[0026] [0026]FIGS. 6 a, 6 b, 7 a and 7 b are plan and end views of alternative heat sink blocks for the tool carrier seen in FIG. 5;
[0027] [0027]FIGS. 8 a and 8 b show hardness profiles for blanks for a 10 mm diameter “jobber drill” (twist drill) heat treated respectively by a process according to an embodiment of the present invention (FIG. 8 a ) and a molten salt bath process (FIG. 8 b ); and
[0028] [0028]FIG. 9 is a view similar to FIG. 1, illustrating a modification to the load/unload conveyor arrangement.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] Referring to FIG. 1, a rotary hearth furnace 2 is shown along with an associated load and unload conveyor system 4 . The furnace is designed for heat treating tool blanks, in this example blanks for twist drills formed from high speed steel (HSS).
[0030] The annular interior of the furnace 2 is divided into ten equally sized zones 6 around its circumference. Likewise, the rotary hearth 8 of the furnace 2 is sub-divided into ten equal segments 10 , each segment 10 being adapted for transporting a batch of tool blanks 12 sequentially through the zones 6 of the furnace in a tool carrier 14 as the hearth is indexed through ten corresponding positions.
[0031] The furnace is operated at or very near ambient atmospheric pressure. That is to say it is not evacuated. In this preferred embodiment, the furnace atmosphere (i.e. the atmosphere within the furnace) is nitrogen gas. This helps prevent discolouration of the blanks, and possible de-carburisation of the steel which might occur if they were exposed to oxygen at the high temperatures at which the furnace operates (1150-1230° C.).
[0032] In use, tools are loaded in batches into the carriers 14 , which then travel along the load conveyor 16 to arrive one at a time at transfer table 18 . From here, the carrier 14 is loaded into the furnace 2 , onto a segment 10 of the hearth 8 in a load/unload zone 20 of the furnace 2 . The hearth is then indexed by the length of one segment 10 , in the anti-clockwise direction as indicated by arrows A in FIG. 1, taking the just loaded carrier 14 a into the first of two pre-heat zones 22 , 24 , and bringing another carrier 14 b from the last of five cooling zones 26 - 30 into the load/unload zone 20 . The carrier 14 b is then extracted from the furnace 2 onto the transfer table 18 , from where it travels along the unload conveyor 34 , which runs parallel with but in the opposite direction to the load conveyor 16 . The now heat treated, hardened tool blanks are then removed for further processing (e.g. flute grinding, etc.).
[0033] In subsequent indexing steps, the carrier 14 a and the segment 10 of the hearth on which it sits are taken sequentially through the second pre-heat zone 24 , two high temperature heating zones 36 , 38 and the five cooling zones 26 , to return to the load/unload zone 20 . The pre-heat zones 22 , 24 serve to bring the temperature of the blanks up to about 900° C., prior to their being exposed to the very high temperatures in the heating zones 36 , 38 . This avoids very rapid heating of the blanks 12 , which might lead to undesirable distortion. The time spent in the two heated zones 36 , 38 , in which the tool blanks 12 are elevated to a temperature of about 1200° C., is sufficient to ensure that the blanks 12 are heated through to their cores. The blanks are then rapidly cooled as they enter the first cooling zone 26 , very quickly cooling to a temperature of about 600° C. As they pass through the remaining four cooling zones 27 - 30 , the blanks 12 then cool down to around ambient temperature before being discharged from the furnace 2 .
[0034] Insulation ‘bridges’ (not shown)—that is to say insulating members which span the width of the furnace interior, but which do not encroach on the passage of the tool blanks—are located between the second high temperature zone and the first cooling zone and between the cooling zones themselves. It is notable that this arrangement of the zones, with the tool blanks being loaded and unloaded to and from a cool zone, which is separated from the heated zones not only by the insulating bridges, but also by the two pre-heat zones, leads to only very little loss of heat from the furnace to the surrounding environment.
[0035] Each time the hearth 8 is indexed, one carrier 14 holding treated tool blanks is unloaded from the load/unload zone 20 , to be replaced with a carrier holding new blanks ready for treatment. In this way, the process can operate continuously in a very efficient manner, with both loading and unloading of the carriers taking place at the same location. Advantageously, the rotary hearth design of furnace 2 also takes up a relatively small amount of floor space, particularly when compared with the known vacuum furnaces.
[0036] Turning to FIGS. 2, 3 and 4 , the construction of the furnace will now be explained in more detail. As seen best in FIG. 2, which shows a section through one of the heating zones 38 on the right and one of the cooling zones 30 on the left, the hearth 8 of the furnace is mounted for rotation within a housing 40 . An opening (not shown) is formed in the housing 40 adjacent the load/unload zone 20 , through which the tool carriers 14 can be introduced and removed. A pit 42 below the furnace houses a motor (not shown) to drive a rotor 44 to which the hearth 8 is mounted and by which it is driven to move the segments 10 of the hearth 8 step-wise through the zones 6 of the furnace 2 . Any of a variety of indexing mechanisms may be used for this drive, including for example a globoidal cam indexing mechanism. Such a mechanism is particularly preferred because, although it is simple in construction, it can very accurately index the hearth 8 (e.g. within ±1.0 mm).
[0037] Mounted on each hearth segment 10 is a base plate 50 of mild steel (MS). These plates 50 are water cooled, water being pumped (e.g. at about 3-4 bar) through channels provided in the plate for this purpose. The coolant is supplied under pressure to each base plate 50 from a common supply via the hub of the hearth 8 , from where the coolant is transferred to the plates 50 through flexible pipework. A fitting at the hub allows for relative rotation between a stationary supply pipe and the pipework rotating with the hearth, whilst maintaining a flow of coolant from one to the other.
[0038] The tool carrier 14 , the structure of which is described further below, stands on the base plate 50 , such that it is in thermal communication with the base plate to be cooled by it.
[0039] The heating zones 36 , 38 , as well as the pre-heat zones 22 , 24 are enclosed at their sides and top by a thick layer of an insulating material 52 , to help maintain the necessary elevated temperature in these zones. The insulation 52 a across the top of the heated zones 36 , 38 , and the second pre-heat zone 24 is broken to allow an array of heating elements 54 , in this example four side by side in each zone, to protrude through the insulation from above into the interior of the furnace. The elements are preferably electrically conducting elements which rely on resistance heating, allowing their temperature to be accurately and rapidly controlled. Silicon carbide elements have been found to be particularly suitable.
[0040] The first pre-heat zone 22 does not contain any heating elements in this example, instead being heated by radiated and/or convected heat from the second pre-heat zone 24 .
[0041] The heating elements 54 are equally spaced from one another across the width of the heated zone 38 to define between them three circumferentially extending passages 56 of equal width along which the tool blanks 12 travel as the hearth 8 is indexed. This arrangement, along with the design of the tool carrier 14 (described below) ensures that all of the blanks 12 are uniformly heated by radiant heat from the elements 54 . It is to be noted in particular that, unlike the known vacuum furnace described above, the elements 54 are arranged to be very closely spaced from the tool blanks 12 , allowing very accurate control of the heating of the blanks 12 . Typically, the spacing between an element and an adjacent tool will be about 50 mm or less, although the precise spacing for any particular batch of tools can be selected dependent on the heat treatment regime they require, by adjusting the position of the blanks in their carrier 14 .
[0042] Further control is effected by monitoring the temperature in the high temperature heating zones 36 , 38 of the furnace and the second pre-heat zone 24 , for example using standard thermocouples, and controlling the power to the heating elements to maintain the desired temperatures in these zones. In a typical set up, six thermocouples in each of these three zones would be adequate to give the desired control. The three zones are preferably independently controlled. By way of example, typical temperatures in the three controlled zones would be about 1000° C. in the second pre-heat zone 24 , about 1200° C. in the first high temperature heating zone 36 , and about 1230° C. in the second high temperature zone 38 . Actual values may be varied dependent on factors such as the desired heat treatment regime and the material of the tools being treated.
[0043] In the cooling zones 26 - 30 , which are not insulated, cooling elements 60 depend downwardly from a roof member 62 in a similar array-like fashion to the heating elements 54 , defining continuations 56 a of the passages 56 defined between those elements 54 . The cooling elements are aluminium blocks, which similarly to the base plates 50 , are formed with channels through which cooling water is pumped, in this example at about 3-4 bar pressure. This arrangement can provide for very rapid, yet controlled cooling of the blanks 12 , which is less harsh than the nitrogen quench of the known furnace, resulting in minimal if any distortion.
[0044] As already noted, the blanks are carried through the furnace 2 in tool carriers 14 . Referring to FIGS. 3 and 4, each of these carriers has an MS base 70 on which are mounted three MS heat sinks 72 , which are equally spaced across the width of the base and extend for the full length of the base 70 . The spaces between the heat sinks 72 are filled with an insulating refractory material 74 .
[0045] As seen in FIG. 5, the heat sinks 72 are each formed from two MS blocks 72 a, 72 b, joined mid-way along the length of the base 70 , which are offset at a small angle to one another so that the line of each heatsink 72 approximates to the curvature of the hearth 8 on which they are carried. The base 70 is similarly shaped. The positions of the heatsinks 72 across the width of the base 70 is such that they coincide with the passages 56 , 56 a defined by the heating and cooling elements 54 , 60 .
[0046] In the top surface of each block 72 a, 72 b of the heat sink 72 , there is formed an elongate recess 75 , extending for the full length of the block. Received snugly in this recess is a tool holder 76 , also of MS, in the top surface of which are formed a uniformly spaced series of holes 78 sized to accept the shank ends 80 of the tool blanks 12 to be treated. When received in the holders 76 , the tool blanks protrude upwardly so that their cutting portions lie between the heating elements 54 as they travel through the heating zones 56 , 58 of the furnace 2 . In this way, the cutting portions are exposed to the radiant heat from the elements 54 , whilst the shanks are shielded within the holders, which are themselves disposed below the level of the heating elements (see FIGS. 3 and 4).
[0047] The tool holders 76 , which are themselves cooled by the water-cooled base plate 50 through the heatsinks 72 , also serve to conduct heat away from the shank 80 when it is in the furnace 2 . This, together with the shielding they provide, ensures that the temperature of the shanks 80 is kept below about 800° C., so they are not hardened to any significant degree.
[0048] The division between the soft shank end 80 of the tool blank 12 and the hardened cutting portion 82 can be controlled by the depth of the holes 78 in the tool holder, the deeper the holes the longer the soft shank 80 . The transition between the hardened and soft portions of the blank will not coincide precisely with the depth of the hole, due to the effects of conduction of heat through the blank itself, but it is a matter of simple experimentation to determine the relationship between hole depth and the location of the transition for any particular design of tool.
[0049] The degree of hardening will also be influenced significantly by the spacing between the tool blanks 12 and the heating elements 54 in the furnace 2 . This can be controlled by appropriate positioning of the holes 78 in the tool holders 76 . Different diameter tool blanks will also require different hole arrangements to ensure that they are uniformly heated. The tool holders 76 seen in FIG. 5, having two staggered rows of holes 78 in each holder, would be appropriate, for example, for tools having a diameter of about 8-10 mm. For larger diameter tools, a single row of holes, as seen for example in FIGS. 6 a and 6 b would be more appropriate, whereas smaller diameter tools can be packed more tightly (FIGS. 7 a and 7 b ).
[0050] Advantageously, this approach to accommodating different size tools means that only the tool holders 76 need be changed for different tool batches. A further advantage is that a great degree of control is given over the hardening process by the variables in the described furnace structure, including the position of the heat sinks, the flow of cooling water, the amount of insulation between the heat sink blocks, and the spacing and depth of the holes in the tool holders, the particular optimum parameters for any form of tool, taking into account also the temperatures and time spent in the furnace, being deducible by experimentation. This in turn means that the furnace operating parameters need not necessarily be altered for different forms of tools, the characteristics of the heat treatment process instead being controlled through an appropriate selection of the heat sinks and holders. This has the great advantage that different forms of tool can follow one another through the furnace without any significant time loss.
[0051] [0051]FIGS. 8 a and 8 b illustrate the effectiveness of the heat treatment process possible using the furnace described above. Specifically, if one compares the hardness characteristic of two identical tool blanks (in this example blanks for 10 mm diameter HSS twist drills), one treated in a rotary hearth furnace in accordance with the invention (FIG. 8 a ) and the other in a conventional salt bath (FIG. 8 b ), it can be seen that similar hardness of the cutting portions (i.e. “flute length”) is achieved by both processes, whereas the shank of the blank treated in accordance with the present invention is, if anything, softer than that arrived at conventionally. Moreover, tests have shown that this approach produces very consistent final hardness figures, attributable to the re-produceable heating and cooling profiles that can be achieved for each cycle of work.
[0052] As will be appreciated, the specific example described above is intended to be illustrative, and many modifications to the apparatus described can be made without departing from the invention. For instance, as illustrated in FIG. 9, additional cooling may be provided by cooling fans 90 positioned above the unload conveyor 34 . This figure also illustrates vacuum locks 92 which are provided in this example to stop the ingress of oxygen into the furnace during loading and unloading of the tools. During loading, the tools enter the vacuum lock chamber 92 a at the end of the load conveyor 16 . Doors on either side of the chamber seal the chamber, and the gas within the chamber is pumped down to approximately 1×10 −2 m bar. The chamber is then back-filled with N 2 gas from the furnace. The tools are then loaded into the furnace through the inner chamber door (ie. the one that opens to the furnace load zone). This scheme substantially prevents any oxygen entering the furnace.
[0053] Vacuum lock 92 b operates in a similar way when the tools are unloaded from the furnace onto the unload conveyor 34 . | Apparatus for heat treating a cutting tool comprises a furnace and a tool holder within the furnace adapted to receive therein a first portion of the tool, a second portion of the tool projecting from the tool holder, the second portion of the tool being directly exposed to radiant heat from at least one radiant heating element within the furnace with the first portion of the tool being shielded from the radiant heat. | 5 |
CROSS-REFERENCES TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 14/169,719, filed Jan. 31, 2014, which is a continuation of U.S. patent application Ser. No. 13/211,243, filed Aug. 16, 2011, which claims the benefit of U.S. Patent Application No. 61/382,836, filed Sep. 14, 2010, the disclosures of which are hereby incorporated by reference for all purposes.
FIELD OF THE INVENTION
The present invention generally relates to wireless communication systems employing Distributed Antenna Systems (DAS) as part of a distributed wireless network. More specifically, the present invention relates to a DAS utilizing software defined radio (SDR).
BACKGROUND OF THE INVENTION
Wireless and mobile network operators face the continuing challenge of building networks that effectively manage high data-traffic growth rates. Mobility and an increased level of multimedia content for end users requires end-to-end network adaptations that support both new services and the increased demand for broadband and flat-rate Internet access. One of the most difficult challenges faced by network operators is caused by the physical movements of subscribers from one location to another, and particularly when wireless subscribers congregate in large numbers at one location. A notable example is a business enterprise facility during lunchtime, when a large number of wireless subscribers visit a cafeteria location in the building. At that time, a large number of subscribers have moved away from their offices and usual work areas. It's likely that during lunchtime there are many locations throughout the facility where there are very few subscribers. If the indoor wireless network resources were properly sized during the design process for subscriber loading as it is during normal working hours when subscribers are in their normal work areas, it is very likely that the lunchtime scenario will present some unexpected challenges with regard to available wireless capacity and data throughput.
To accommodate this variation in subscriber loading, there are several candidate prior art approaches.
One approach is to deploy many low-power high-capacity base stations throughout the facility. The quantity of base stations is determined based on the coverage of each base station and the total space to be covered. Each of these base stations is provisioned with enough radio resources, i.e., capacity and broadband data throughput to accommodate the maximum subscriber loading which occurs during the course of the workday and work week. Although this approach typically yields a high quality of service, the notable disadvantage of this approach is that during a major part of the time many of the base stations' capacity is being wasted. Since a typical indoor wireless network deployment involves capital and operational costs which are assessed on a per-subscriber basis for each base station, the typically high total life cycle cost for a given enterprise facility is far from optimal.
A second candidate approach involves deployment of a DAS along with a centralized group of base stations dedicated to the DAS. A conventional DAS deployment falls into one of two categories. The first type of DAS is “fixed”, where the system configuration doesn't change based on time of day or other information about usage. The remote units associated with the DAS are set up during the design process so that a particular block of base station radio resources is thought to be enough to serve each small group of DAS remote units. A notable disadvantage of this approach is that most enterprises seem to undergo frequent re-arrangements and re-organizations of various groups within the enterprise. Therefore, it's highly likely that the initial setup will need to be changed from time to time, requiring deployment of additional staff and contract resources with appropriate levels of expertise regarding wireless networks.
The second type of DAS is equipped with a type of network switch which allows the location and quantity of DAS remote units associated with any particular centralized base station to be changed manually. Although this approach would seem to allow dynamic reconfiguration based on the needs of the enterprise or based on time of day, it frequently requires deployment of additional staff resources for real-time management of the network. Another issue is that it's not always correct or best to make the same DAS remote unit configuration changes back and forth on each day of the week at the same times of day. Frequently it is difficult or impractical for an enterprise IT manager to monitor the subscriber loading on each base station. And it is almost certain that the enterprise IT manager has no practical way to determine the loading at a given time of day for each DAS remote unit; they can only guess.
Another major limitation of prior art DAS deployments is related to their installation, commissioning and optimization process. Some challenging issues which must be overcome include selecting remote unit antenna locations to ensure proper coverage while minimizing downlink interference from outdoor macro cell sites, minimizing uplink interference to outdoor macro cell sites, and ensuring proper intra-system handovers while indoors and while moving from outdoors to indoors (and vice-versa). The process of performing such deployment optimization is frequently characterized as trial-and-error and as such, the results may not be consistent with a high quality of service.
A major limitation of prior art DAS equipment employing digital transmission links such as optical fiber or wired Ethernet is the fact that the prior-art RF-to-digital conversion techniques utilize an approach whereby the system converts a single broad RF bandwidth of e.g., 10 to 25 MHz to digital. Therefore all the signals, whether weak or strong, desired or undesired, contained within that broad bandwidth are converted to digital, whether those signals are desired or not. This approach frequently leads to inefficiencies within the DAS which limit the DAS network capacity. It would be preferable to employ an alternative approach yielding greater efficiencies and improved flexibility, particularly for neutral host applications.
In 2008 the FCC further clarified its E-911 requirements with regard to Phase 2 accuracy for mobile wireless networks. The information required in Phase 2 is the mobile phone number and the physical location, within a few dozen yards, from which the call was made. The Canadian government is reportedly considering enacting similar requirements. Also the FCC is eager to see US mobile network operators provide positioning services with enhanced accuracy for E-911 for indoor subscribers. There is a reported effort within the FCC to try to mandate Phase 2 accuracy indoors, within the next 2 years.
Many wireless networks employ mobile and fixed broadband wireless terminals which employ GPS-based E-911 location services. It has been demonstrated that GPS signals from satellites outdoors don't propagate well into the indoor space. Therefore an alternative, more robust E-911 location determination approach is required for indoors, particularly if the FCC requirements are changed to be more stringent.
Several US operators have expressed concern about how they can practically and cost-effectively obtain these enhanced location accuracy capabilities. Operators are very eager to identify a cost-effective approach which can be deployed indoors for enhanced location accuracy.
One proposed approach toward indoor location accuracy enhancement for CDMA networks would employ a separate unit known as a CDMA Pilot Beacon. A notable disadvantage of this approach for an indoor OAS application is that since the CDMA Pilot Beacon unit is a separate and dedicated device and not integrated within the OAS, it would likely be costly to deploy. The Pilot Beacon approach for CDMA networks employs a Pilot Beacon with a unique PN code (in that area) which effectively divides a particular CDMA network coverage area (e.g., indoors) into multiple small zones (which each correspond to the coverage area of a low-power Pilot Beacon). Each Pilot Beacon's location, PN code and RF Power level are known by the network. Each Pilot Beacon must be synchronized to the CDMA network, via GPS or local base station connection. A variable delay setting permits each Pilot Beacon to have the appropriate system timing to permit triangulation and/or Cell 10 position determination. One optional but potentially costly enhancement to this approach would employ a Wireless Modem for each Pilot Beacon to provide remote Alarms, Control and Monitoring of each CDMA Pilot Beacon. No known solution for indoor location accuracy enhancement has been publicly proposed for WCDMA networks.
One candidate technically-proven approach toward indoor location accuracy enhancement for GSM networks would employ a separate unit known as a Location Measurement Unit or LMU. A notable disadvantage of this approach for an indoor DAS application is that, since the LMU is a separate and dedicated device and not integrated within the DAS, it is costly to deploy. Each LMU requires a backhaul facility to a central server which analyzes the LMU measurements. The LMU backhaul cost adds to the total cost of deploying the enhanced accuracy E-911 solution for GSM networks. Despite the availability of the already technically-proven LMU approach, it has not been widely deployed in conjunction with indoor DAS.
Based on the prior art approaches described herein, it is apparent that a highly efficient, easily deployed and dynamically reconfigurable wireless network is not achievable with prior art systems and capabilities.
BRIEF SUMMARY OF THE INVENTION
The present invention substantially overcomes the limitations of the prior art discussed above. The advanced system architecture of the present invention provides a high degree of flexibility to manage, control, enhance and facilitate radio resource efficiency, usage and overall performance of the distributed wireless network. This advanced system architecture enables specialized applications and enhancements including flexible simulcast, automatic traffic load-balancing, network and radio resource optimization, network calibration, autonomous/assisted commissioning, carrier pooling, automatic frequency selection, radio frequency carrier placement, traffic monitoring, traffic tagging, and indoor location determination using pilot beacons. The present invention can also serve multiple operators, multi-mode radios (modulation-independent) and multi-frequency bands per operator to increase the efficiency and traffic capacity of the operators' wireless networks.
Accordingly, it is an object of the present invention to provide a capability for Flexible Simulcast. With Flexible Simulcast, the amount of radio resources (such as RF carriers, CDMA codes or TDMA time slots) assigned to a particular RRU or group of RRUs by each RRU Access Module can be set via software control as described hereinafter to meet desired capacity and throughput objectives or wireless subscriber needs. To achieve these and other objects, an aspect of the present invention employs software-programmable frequency selective Digital Up-Converters (DUCs) and Digital Down-Converters (DDCs). A software-defined Remote Radio Head architecture is used for cost-effective optimization of the radio performance. Frequency selective DDCs and DUCs at the Remote Radio Head enable a high signal to noise ratio (SNR) which maximize the throughput data rate. An embodiment shown in FIG. 1 depicts a basic structure and provides an example of a Flexible Simulcast downlink transport scenario. FIG. 2 depicts an embodiment of a basic structure of a Flexible Simulcast uplink transport scenario.
It is a further object of the present invention to facilitate conversion and transport of several discrete relatively narrow RF bandwidths. In another aspect of the invention, an embodiment converts only that plurality of specific, relatively narrow bandwidths that carry useful information. Thus, this aspect of the present invention allows more efficient use of the available optical fiber transport bandwidth for neutral host applications, and facilitates transport of more operators' band segments over the optical fiber. To achieve the above result, the present invention utilizes frequency-selective filtering at the Remote Radio Head which enhances the system performance. In some embodiments of this aspect of the invention, noise reduction via frequency-selective filtering at the Remote Radio Head is utilized for maximizing the SNR and consequently maximizing the data throughput. It is a further object of the present invention to provide CDMA and WCDMA indoor location accuracy enhancement. In an aspect of the present invention, an embodiment provides enhanced location accuracy performance by employing pilot beacons. FIG. 3 depicts a typical indoor system employing multiple Remote Radio Head Units (RRUs) and a central Digital Access Unit (DAU). The Remote Radio Heads have a unique beacon that is distinct and identifies that particular indoor cell. The mobile user will use the beacon information to assist in the localization to a particular cell.
It is a further object of the present invention to enhance GSM and LTE indoor location accuracy. In another aspect, an embodiment of the present invention provides localization of a user based on the radio signature of the mobile device. FIG. 4 depicts a typical indoor system employing multiple Remote Radio Head Units (RRUs) and a central Digital Access Unit (DAU). In accordance with the invention, each Remote Radio Head provides unique header information on data received by that Remote Radio Head. The system of the invention uses this header information in conjunction with the mobile user's radio signature to localize the user to a particular cell. It is a further object of the present invention to re-route local traffic to Internet VOIP, Wi-Fi or WiMAX. In this aspect of the invention, an embodiment determines the radio signatures of the individual users within a DAU or Island of DAUs and uses this information to identify if the users are located within the coverage area associated with a specific DAU or Island of DAUs. The DAUs track the radio signatures of all the active users within its network and record a running data base containing information pertaining to them. One embodiment of the present invention is for the Network Operations Center (NOC) to inform the DAU that, e.g., two specific users are collocated within the same DAU or Island of DAUs, as depicted in FIG. 6 . The DAUs then reroute the users to Internet VOIP, Wi-Fi or WiMAX as appropriate. Another embodiment of the present invention is to determine the Internet Protocol (IP) addresses of the individual users' Wi-Fi connections. If the individual users' IP addresses are within the same DAU or Island of DAUs, the data call for these users is rerouted over the internal network.
Applications of the present invention are suitable to be employed with distributed base stations, distributed antenna systems, distributed repeaters, mobile equipment and wireless terminals, portable wireless devices, and other wireless communication systems such as microwave and satellite communications. The present invention is also field upgradable through a link such as an Ethernet connection to a remote computing center.
Appendix I is a glossary of terms used herein, including acronyms.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and advantages of the present invention can be more fully understood from the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a block diagram according to one embodiment of the invention showing the basic structure and an example of a Flexible Simulcast downlink transport scenario based on having 2 DAU and 4 DRU.
FIG. 2 is a block diagram in accordance with an embodiment of the invention showing the basic structure and an example of a Flexible Simulcast uplink transport scenario based on having 2 DAU and 4 DRU.
FIG. 3 shows an embodiment of an indoor system employing multiple Remote Radio Head Units (RRUs) and a central Digital Access Unit (DAU).
FIG. 4 shows an embodiment of an indoor system in accordance with the invention which employs multiple Remote Radio Head Units (RRUs) and a central Digital Access Unit (DAU).
FIG. 5 illustrates an embodiment of a cellular network system employing multiple Remote Radio Heads according to the present invention.
FIG. 6 is a depiction of local connectivity according to one embodiment of the present invention.
FIG. 7 illustrates an embodiment of the basic structure of the embedded software control modules which manage key functions of the DAU and RRU, in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is a novel Reconfigurable Distributed Antenna System that provides a high degree of flexibility to manage, control, re-configure, enhance and facilitate the radio resource efficiency, usage and overall performance of the distributed wireless network. An embodiment of the Reconfigurable Distributed Antenna System in accordance with the present invention is shown in FIG. 1 . The Flexible Simulcast System 100 can be used to explain the operation of Flexible Simulcast with regard to downlink signals. The system employs a Digital Access Unit functionality (hereinafter “DAU”). The DAU serves as an interface to the base station (BTS). The DAU is (at one end) connected to the BTS, and on the other side connected to multiple RRUs. For the downlink (DL) path, RF signals received from the BTS are separately down-converted, digitized, and converted to baseband (using a Digital Down-Converter). Data streams are then I/Q mapped and framed. Specific parallel data streams are then independently serialized and translated to optical signals using pluggable SFP modules, and delivered to different RRUs over optical fiber cable. For the uplink (UL) path optical signals received from RRUs are deserialized, deframed, and up-converted digitally using a Digital Up-Converter. Data streams are then independently converted to the analog domain and up-converted to the appropriate RF frequency band. The RF signal is then delivered to the BTS. An embodiment of the system is mainly comprised of DAU 1 indicated at 101 , RRU 1 indicated at 103 , RRU 2 indicated at 104 , DAU 2 indicated at 102 , RRU 3 indicated at 105 , and RRU 4 indicated at 106 . A composite downlink input signal 107 from, e.g., a base station belonging to one wireless operator enters DAU 1 at the DAU 1 RF input port. Composite signal 107 is comprised of Carriers 1 - 4 . A second composite downlink input signal from e.g., a second base station belonging to the same wireless operator enters DAU 2 at the DAU 2 RF input port. Composite signal 108 is comprised of Carriers 5 - 8 . The functionality of DAU 1 , DAU 2 , RRU 1 , RRU 2 , RRU 3 and RRU 4 are explained in detail by U.S. Provisional Application Ser. No. 61/374593, entitled “Neutral Host Architecture for a Distributed Antenna System,” filed Aug. 17, 2010 and attached hereto as an appendix. One optical output of DAU 1 is fed to RRU 1 . A second optical output of DAU 1 is fed via bidirectional optical cable 113 to DAU 2 . This connection facilitates networking of DAU 1 and DAU 2 , which means that all of Carriers 1 - 8 are available within DAU 1 and DAU 2 to transport to RRU 1 , RRU 2 , RRU 3 and RRU 4 depending on software settings within the networked DAU system comprised of DAU 1 and DAU 2 . The software settings within RRU 1 are configured either manually or automatically such that Carriers 1 - 8 are present in the downlink output signal 109 at the antenna port of RRU 1 . The presence of all 8 carriers means that RRU 1 is potentially able to access the full capacity of both base stations feeding DAU 1 and DAU 2 . A possible application for RRU 1 is in a wireless distribution system is e.g., a cafeteria in an enterprise building during the lunch hour where a large number of wireless subscribers are gathered. RRU 2 is fed by a second optical port of RRU 1 via bidirectional optical cable 114 to RRU 2 . Optical cable 114 performs the function of daisy chaining RRU 2 with RRU 1 . The software settings within RRU 2 are configured either manually or automatically such that Carriers 1 , 3 , 4 and 6 are present in downlink output signal 110 at the antenna port of RRU 2 . The capacity of RRU 2 is set to a much lower value than RRU 1 by virtue of its specific Digital Up Converter settings. The individual Remote Radio Units have integrated frequency selective DUCs and DDCs with gain control for each carrier. The DAUs can remotely turn on and off the individual carriers via the gain control parameters.
In a similar manner as described previously for RRU 1 , the software settings within RRU 3 are configured either manually or automatically such that Carriers 2 and 6 are present in downlink output signal 111 at the antenna port of RRU 3 . Compared to the downlink signal 110 at the antenna port of RRU 2 , the capacity of RRU 3 which is configured via the software settings of RRU 3 is much less than the capacity of RRU 2 . RRU 4 is fed by a second optical port of RRU 3 via bidirectional optical cable 115 to RRU 4 . Optical cable 115 performs the function of daisy chaining RRU 4 with RRU 3 . The software settings within RRU 4 are configured either manually or automatically such that Carriers 1 , 4 , 5 and 8 are present in downlink output signal 112 at the antenna port of RRU 4 . The capacity of RRU 4 is set to a much lower value than RRU 1 . The relative capacity settings of RRU 1 , RRU 2 , RRU 3 and RRU 4 and can be adjusted dynamically as discussed in connection with FIG. 7 to meet the capacity needs within the coverage zones determined by the physical positions of antennas connected to RRU 1 , RRU 2 , RRU 3 and RRU 4 respectively.
The present invention facilitates conversion and transport of several discrete relatively narrow RF bandwidths. This approach allows conversion of only those multiple specific relatively narrow bandwidths which carry useful or specific information. This approach also allows more efficient use of the available optical fiber transport bandwidth for neutral host applications, and allows transport of more individual operators' band segments over the optical fiber. As disclosed in U.S. Provisional Application Ser. No. 61/374593, entitled “Neutral Host Architecture for a Distributed Antenna System,” filed Aug. 17, 2010 and also referring to FIG. 1 of the instant patent application, Digital Up Converters located within the RRU which are dynamically software-programmable as discussed hereinafter can be re-configured to transport from the DAU input to any specific RRU output any specific narrow frequency band or bands, RF carriers or RF channels which are available at the respective RF input port of either DAU. This capability is illustrated in FIG. 1 where only specific frequency bands or RF carriers appear at the output of a given RRU.
A related capability of the present invention is that not only can the Digital Up Converters located within each RRU be configured to transport any specific narrow frequency band from the DAU input to any specific RRU output, but also the Digital Up Converters within each RRU can be configured to transport any specific time slot or time slots of each carrier from the DAU input to any specific RRU output. The DAU detects which carriers and corresponding time slots are active. This information is relayed to the individual RRUs via the management control and monitoring protocol software discussed hereinafter. This information is then used, as appropriate, by the RRUs for turning off and on individual carriers and their corresponding time slots.
Referring to FIG. 1 of the instant patent application, an alternative embodiment of the present invention may be described as follows. In a previous description of FIG. 1 , a previous embodiment involved having downlink signals from two separate base stations belonging to the same wireless operator enter DAU 1 and DAU 2 input ports respectively. In an alternative embodiment, a second composite downlink input signal from e.g., a second base station belonging to a different wireless operator enters DAU 2 at the DAU 2 RF input port. In this embodiment, signals belonging to both the first operator and the second operator are converted and transported to RRU 1 , RRU 2 , RRU 3 and RRU 4 respectively. This embodiment provides an example of a neutral host wireless system, where multiple wireless operators share a common infrastructure comprised of DAU 1 , DAU 2 , RRU 1 , RRU 2 , RRU 3 and RRU 4 . All the previously mentioned features and advantages accrue to each of the two wireless operators.
As disclosed in U.S. Provisional Application Ser. No. 61/374593, entitled “Neutral Host Architecture for a Distributed Antenna System,” filed Aug. 17, 2010 and also referring to FIG. 1 of the instant patent application, the Digital Up Converters present in the RRU can be programmed to process various signal formats and modulation types including FDMA, CDMA, TDMA, OFDMA and others. Also, the Digital Up Converters present in the respective RRUs can be programmed to operate with signals to be transmitted within various frequency bands subject to the capabilities and limitations of the system architecture disclosed in U.S. Provisional Application Ser. No. 61/374593, entitled “Neutral Host Architecture for a Distributed Antenna System,” filed Aug. 17, 2010. In one embodiment of the present invention where a wideband CDMA signal is present within e.g., the bandwidth corresponding to carrier 1 at the input port to DAU 1 , the transmitted signal at the antenna ports of RRU 1 , RRU 2 and RRU 4 will be a wideband CDMA signal which is virtually identical to the signal present within the bandwidth corresponding to carrier 1 at the input port to DAU 1 .
As disclosed in U.S. Provisional Application Ser. No. 61/374593, entitled “Neutral Host Architecture for a Distributed Antenna System,” filed Aug. 17, 2010 and also referring to FIG. 1 of the instant patent application, it is understood that the Digital Up Converters present in the respective RRUs can be programmed to transmit any desired composite signal format to each of the respective RRU antenna ports. As an example, the Digital Up Converters present in RRU 1 and RRU 2 can be dynamically software-reconfigured as described previously so that the signal present at the antenna port of RRU 1 would correspond to the spectral profile shown in FIG. 1 as 110 , and also that the signal present at the antenna port of RRU 2 would correspond to the spectral profile shown in FIG. 1 as 109 . The application for such a dynamic rearrangement of RRU capacity would be e.g., if a company meeting were suddenly convened in the area of the enterprise corresponding to the coverage area of RRU 2 . Although the description of some embodiments in the instant application refers to base station signals 107 and 108 as being on different frequencies, the system and method of the present invention readily supports configurations where one or more of the carriers which are part of base station signals 107 and 108 and are identical frequencies, since the base station signals are digitized, packetized, routed and switched to the desired RRU.
Another embodiment of the Distributed Antenna System in accordance with the present invention is shown in FIG. 2 . As disclosed in U.S. Provisional Application Ser. No. 61/374593, entitled “Neutral Host Architecture for a Distributed Antenna System,” filed Aug. 17, 2010 and also as shown in FIG. 2 the Flexible Simulcast System 200 can be used to explain the operation of Flexible Simulcast with regard to uplink signals. As discussed previously with regard to downlink signals and by referring to FIG. 1 , the uplink system shown in FIG. 2 is mainly comprised of DAU 1 indicated at 201 , RRU 1 indicated at 203 , RRU 2 indicated at 204 , DAU 2 indicated at 202 , RRU 3 indicated at 205 , and RRU 4 indicated at 206 . In a manner similar to the downlink operation explained by referring to FIG. 1 , the operation of the uplink system shown in FIG. 2 can be understood as follows.
The Digital Down Converters present in each of RRU 1 , RRU 2 , RRU 3 and RRU 4 are dynamically software-configured as described previously so that uplink signals of the appropriate desired signal format(s) present at the receive antenna ports of the respective RRU 1 , RRU 2 , RRU 3 and RRU 4 are selected based on the desired uplink band(s) to be processed and filtered, converted and transported to the appropriate uplink output port of either DAU 1 or DAU 2 . The DAUs and RRUs frame the individual data packets corresponding to their respective radio signature using the Common Public Interface Standard (CPRI). Other Interface standards are applicable provided they uniquely identify data packets with respective RRUs. Header information is transmitted along with the data packet which identifies the RRU and DAU that corresponds to the individual data packet.
In one example for the embodiment shown in FIG. 2 , RRU 1 and RRU 3 are configured to receive uplink signals within the Carrier 2 bandwidth, whereas RRU 2 and RRU 4 are both configured to reject uplink signals within the Carrier 2 bandwidth. When RRU 3 receives a strong enough signal at its receive antenna port within the Carrier 2 bandwidth to be properly filtered and processed, the Digital Down Converters within RRU 3 facilitate processing and conversion. Similarly, when RRU 1 receives a strong enough signal at its receive antenna port within the Carrier 2 bandwidth to be properly filtered and processed, the Digital Down Converters within RRU 1 facilitate processing and conversion. The signals from RRU 1 and RRU 3 are combined based on the active signal combining algorithm, and are fed to the base station connected to the uplink output port of DAU 1 . The term simulcast is frequently used to describe the operation of RRU 1 and RRU 3 with regard to uplink and downlink signals within Carrier 2 bandwidth. The term Flexible Simulcast refers to the fact that the present invention supports dynamic and/or manual rearrangement of which specific RRU are involved in the signal combining process for each Carrier bandwidth.
Referring to FIG. 2 , the Digital Down Converters present in RRU 1 are configured to receive and process signals within Carrier 1 - 8 bandwidths. The Digital Down Converters present in RRU 2 are configured to receive and process signals within Carrier 1 , 3 , 4 and 6 bandwidths. The Digital Down Converters present in RRU 3 are configured to receive and process signals within Carrier 2 and 6 bandwidths. The Digital Down Converters present in RRU 4 are configured to receive and process signals within Carrier 1 , 4 , 5 and 8 bandwidths. The respective high-speed digital signals resulting from processing performed within each of the four RRU are routed to the two DAUs. As described previously, the uplink signals from the four RRUs are combined within the respective DAU corresponding to each base station.
An aspect of the present invention includes an integrated Pilot Beacon function within the each RRU. In an embodiment, each RRU comprises a unique software programmable Pilot Beacon as discussed hereinafter This approach is intended for use in CDMA and/or WCDMA indoor DAS networks. A very similar approach can be effective for indoor location accuracy enhancement for other types of networks such as LTE and WiMAX. Because each RRU is already controlled and monitored via the DAUs which comprise the network, there is no need for costly deployment of additional dedicated wireless modems for remote monitoring and control of pilot beacons.
An RRU-integrated Pilot Beacon approach is employed for both CDMA and WCDMA networks. Each operational pilot beacon function within an RRU employs a unique PN code (in that area) which effectively divides the WCDMA or CDMA indoor network coverage area into multiple small “zones” (which each correspond to the coverage area of a low-power Pilot Beacon). Each Pilot Beacon's location, PN code and RF Power level are known by the network. Each Pilot Beacon is synchronized to the WCDMA or CDMA network, via its connection to the DAU.
Unlike the transmit signal from a base station which is “dynamic”, the Pilot Beacon transmit signal will be effectively “static” and its downlink messages will not change over time based on network conditions.
For a WCDMA network, in Idle mode each mobile subscriber terminal is able to perform Pilot Signal measurements of downlink signals transmitted by base stations and Pilot Beacons. When the WCDMA mobile subscriber terminal transitions to Active mode, it reports to the serving cell all its Pilot Signal measurements for base stations and for Pilot Beacons. For CDMA networks, the operation is very similar. For some RRU deployed in an indoor network, the RRU can be provisioned as either a Pilot Beacon or to serve mobile subscribers in a particular operator bandwidth, but not both.
For a WCDMA network, existing inherent capabilities of the globally-standardized networks are employed. The WCDMA mobile subscriber terminal is able to measure the strongest CPICH RSCP (Pilot Signal Code Power) in either Idle mode or any of several active modes. Also, measurements of CPICH Ec/No by the mobile subscriber terminal in either Idle mode or any of several active modes are possible. As a result, the mobile subscriber terminal reports all available RSCP and Ec/No measurements via the serving base station (whether indoor or outdoor) to the network. Based on that information, the most likely mobile subscriber terminal location is calculated and/or determined. For CDMA networks, the operation is very similar to the process described herein.
A previously described embodiment of the present invention referring to FIG. 1 involved having a wideband CDMA signal present within e.g., the bandwidth corresponding to carrier 1 at the input port to DAU 1 . In the previously described embodiment, the transmitted signal at the antenna ports of RRU 1 , RRU 2 and RRU 4 is a wideband CDMA signal which is virtually identical to the signal present within the bandwidth corresponding to carrier 1 at the input port to DAU 1 . An alternative embodiment of the present invention is one where a wideband CDMA signal is present within e.g., the bandwidth corresponding to carrier 1 at the input port to DAU 1 . However, in the alternative embodiment the transmitted signal at the antenna port of RRU 1 differs slightly from the previous embodiment. In the alternative embodiment, a wideband CDMA signal is present within e.g., the bandwidth corresponding to carrier 1 at the input port to DAU 1 . The transmitted signal from RRU 1 is a combination of the wideband CDMA signal which was present at the input port to DAU 1 , along with a specialized WCDMA pilot beacon signal. The WCDMA pilot beacon signal is intentionally set well below the level of the base station pilot signal.
A further alternative embodiment can be explained referring to FIG. 1 which applies in the case where CDMA signals are generated by the base station connected to the input port of DAU 1 . In this further alternative embodiment of the present invention, the transmitted signal at the antenna port of RRU 1 is a combination of the CDMA signal which was present at the input port to DAU 1 , along with a specialized CDMA pilot beacon signal. The CDMA pilot beacon signal is intentionally set well below the level of the base station pilot signal.
An embodiment of the present invention provides enhanced accuracy for determining location of indoor wireless subscribers. FIG. 4 depicts a typical indoor system employing multiple Remote Radio Head Units (RRUs) and a central Digital Access Unit (DAU). Each Remote Radio Head provides a unique header information on data received by that Remote Radio Head. This header information in conjunction with the mobile user's radio signature are used to localize the user to a particular cell. The DAU signal processing can identify the individual carriers and their corresponding time slots. A header is included with each data packet that uniquely identifies the corresponding RRU. The DAU can detect the carrier frequency and the corresponding time slot associated with the individual RRUs. The DAU has a running data base that identifies each carrier frequency and time slot with a respective RRU. The carrier frequency and time slot is the radio signature that uniquely identifies the GSM user.
The DAU communicates with a Network Operation Center (NOC) via a Ethernet connection or an external modem, as depicted in FIG. 5 . Once a E911 call is initiated the Mobile Switching Center (MSC) in conjunction with the NOC can identify the corresponding BaseTransceiver Station (BTS) where the user has placed the call. The user can be localized within a BTS cell. The NOC then makes a request to the individual DAUs to determine if the E911 radio signature is active in their indoor cell. The DAU checks its data base for the active carrier frequency and time slot. If that radio signature is active in the DAU, then that DAU will provide the NOC with the location information of the corresponding RRU.
A further embodiment of the present invention includes LTE to provide enhanced accuracy for determining the location of indoor wireless subscribers. GSM uses individual carriers and time slots to distinguish users whereas LTE uses multiple carriers and time slot information to distinguish users. The DAU can simultaneously detect multiple carriers and their corresponding time slots to uniquely identify the LTE user. The DAU has a running data base that identifies the carrier frequencies and time slot radio signature for the respective RRU. This information can be retrieved from the NOC once a request is made to the DAU.
Referring next to FIG. 7 , the DAU embedded software control module and RRU embedded software control module can be better understood in connection with the operation of key functions of the DAU and RRU. One such key function is determining and/or setting the appropriate amount of radio resources (such as RF carriers, CDMA codes or TDMA time slots) assigned to a particular RRU or group of RRUs to meet desired capacity and throughput objectives. The DAU embedded software control module comprises a DAU Monitoring module that detects which carriers and corresponding time slots are active for each RRU. The DAU embedded software control module also comprises a DAU Management Control module which communicates with the RRU over a fiber optic link control channel via a control protocol with the RRU Management Control module. In turn, the RRU Management Control module sets the individual parameters of all the RRU Digital Up-Converters to enable or disable specific radio resources from being transmitted by a particular RRU or group of RRUs, and also sets the individual parameters of all the RRU Digital Down-Converters to enable or disable specific uplink radio resources from being processed by a particular RRU or group of RRUs.
In an embodiment, an algorithm operating within the DAU Monitoring module, that detects which carriers and corresponding time slots for each carrier are active for each RRU, provides information to the DAU Management Control module to help identify when, e.g., a particular downlink carrier is loaded by a percentage greater than a predetermined threshold whose value is communicated to the DAU Management Control module by the DAU's Remote Monitoring and Control function. If that occurs, the DAU Management Control module adaptively modifies the system configuration to slowly begin to deploy additional radio resources (such as RF carriers, CDMA codes or TDMA time slots) for use by a particular RRU which need those radio resources within its coverage area. At the same time, in at least some embodiments the DAU Management Control module adaptively modifies the system configuration to slowly begin to remove certain radio resources (such as RF carriers, CDMA codes or TDMA time slots) for use by a particular RRU which no longer needs those radio resources within its coverage area. Another such key function of the DAU embedded software control module and RRU embedded software control module is determining and/or setting and/or analyzing the appropriate transmission parameters and monitoring parameters for the integrated Pilot Beacon function contained within each RRU. These Pilot Beacon transmission and monitoring parameters include Beacon Enable/Disable, Beacon Carrier Frequencies, Beacon Transmit Power, Beacon PN Code, Beacon Downlink BCH Message Content, Beacon Alarm, Beacon Delay Setting and Beacon Delay Adjustment Resolution. The RRU Pilot Beacon Control module communicates with the pilot beacon generator function in the RRU to set and monitor the pilot beacon parameters as listed herein.
In summary, the Reconfigurable Distributed Antenna System of the present invention described herein efficiently conserves resources and reduces costs. The reconfigurable system is adaptive or manually field-programmable, since the algorithms can be adjusted like software in the digital processor at any time.
Although the present invention has been described with reference to the preferred embodiments, it will be understood that the invention is not limited to the details described thereof. Various substitutions and modifications have been suggested in the foregoing description, and others will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the appended claims. | The present disclosure is a novel utility of a software defined radio (SDR) based Distributed Antenna System (DAS) that is field reconfigurable and support multi-modulation schemes (modulation-independent), multi-carriers, multi-frequency bands and multi-channels. The present disclosure enables a high degree of flexibility to manage, control, enhance, facilitate the usage and performance of a distributed wireless network such as flexible simulcast, automatic traffic load-balancing, network and radio resource optimization, network calibration, autonomous/assisted commissioning, carrier pooling, automatic frequency selection, frequency carrier placement, traffic monitoring, traffic tagging, pilot beacon, etc. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates of production of heavy hydrocarbons contained in an underground formation by an assisted recovery process using wells drilled with an essentially horizontal section, said wells having an initial practically vertical section starting at the surface of the ground, followed by an inclined or horizontal section extending into the formation.
Extraction of heavy hydrocarbons from an underground formation implies production mechanisms designed essentially to reduce viscosity and to cause displacement followed by aspiration of the heavy oil into wells, and finally bringing it to the surface. There are two methods for generating the energy required for displacement: producing this energy at the surface, in the case of injection of hot fluids (U.S. Pat. No. 4,325,432) or the creation of such fluids in the formation, as in the case of in situ combustion (U.S. Pat. No. 4,501,326).
This principle of reducing the viscosity of heavy oil by heating is generally accompanied by careful selection of well-drilling locations to use the injected energy with increased efficiency.
Hence, development in recent years has stressed the use of wells drilled horizontally in a layer of a formation to increase production yield. Horizontal wells have made it possible (a) to reach reservoirs of hydrocarbons in locations sometimes inaccessible to vertical wells, and (b) have shown improved profitability in production and extraction of petroleum located in certain types of formations.
Hence, initial developments were directed at using horizontal wells to produce heavy hydrocarbons by injecting steam.
Steam injected into a will diffuses in the hydrocarbon, reducing its viscosity and starting its displacement toward a producing well by thermal transmission.
A method of this kind is described in U.S. Pat. No. 4,700,779, in which the reservoir containing the heavy hydrocarbon is pierced by a series of wells with horizontal drains whose horizontal sections are parallel to one another and extend longitudinally in the reservoir.
The hydrocarbon production process is worked by activating a first well in a first stage and a second well located at one end of the formation by injecting steam, and capturing the hydrocarbon in a second step after starting heating in the second well immediately adjacent, which is then transformed from an injector into a producer.
When the opening formed by the steam reaches the second well, steam injection is suspended in the first well and replaced by water injection to maintain sufficient pressure in the reservoir.
It is then sufficient to shift the functions of the wells to extract, at a third well, the hydrocarbon set in motion by the injection of steam at the second well.
Such a technique has been used successfully for production from a hydrocarbon reservoir, but this system can be used only when the hydrocarbon is contained in a single reservoir, while in many cases it is divided among reservoirs superimposed on one another and separated by impermeable secondary rocks. In such cases, each reservoir must be treated individually by the process described above, which rapidly leads to complications in controlling the wells (transmission of commands to switch from production to injection and vice versa) when the number of stratified layers is large.
SUMMARY OF THE INVENTION
The present invention is intended to overcome the above shortcomings when it is desired to use wells with horizontal drains to inject steam through a formation of superimposed reservoirs, and thus eliminate the use of wells alternately for injection and production. In addition, the present invention advantageously makes use of the heat losses into the secondary rocks that occur in conjunction with the injection of steam; in the patent cited above, these losses constitute a major disadvantage because they reduce the production of a well.
The essence of the present invention is the drilling of wells with horizontal drains in each of the superimposed reservoirs, said drains being located in parallel vertical planes, followed by the use of one well for steam injection, with the wells located in the two adjacent layers then being producers.
With this arrangement, heat losses propagated vertically through the rocks are used to ensure acceleration of the heavy hydrocarbon to the producing wells located in the contiguous reservoirs.
The start of production, always accomplished by displacement of fluids, is thus speeded up by the transmission of heat. Hence, the goal of the present invention is to provide a process for assisted recovery of heavy hydrocarbons from underground formations by drilling wells each with an essentially horizontal section, said wells having, at the point where they leave the surface of the ground, an initial practically vertical section, followed by an inclined or horizontal section extending into the formation composed of reservoirs of said hydrocarbons, wherein:
a jet of steam is injected into the formation through a first series of horizontal wells;
the hydrocarbon is extracted from the formation by a second series of horizontal wells, characterized by the formation being composed of at least two superimposed reservoirs separated by secondary rocks, with the horizontal section of a first well extending into a reservoir essentially perpendicular to the horizontal section of a second well located in an immediately adjacent reservoir,
said first well being used as a steam-injection well and the second well as a hydrocarbon-producing well.
In this manner, the hydrocarbon is recovered in the simplest way by two wells with horizontal drains located essentially one above the other in two superimposed layers, the first being the injector and the second the producer, with the injection of steam involving heat transmission through the rock separating them and rapidly causing the start of production in the second well.
According to a particular embodiment of the invention, two horizontal well sections are disposed parallel and in succession in a regular fashion within one reservoir, and the two successive wells located along said reservoir are operated so that one well is for injecting steam and the other well is for--; producing hydrocarbons.
Production capacities are increased by using in addition, a plurality of wells in each reservoir, spaced at regular intervals, said wells acting in succession as producers and injectors in a given reservoir.
Advantageously, the formation comprises a succession of superimposed reservoirs, and a network of wells is formed in a vertical cross section of the formation, with a horizonal section that is essentially orthogonal and extends (a) in a transverse direction at the level of each reservoir and (b) in another, longitudinal direction in said reservoir, and a first series of wells is operated to inject steam, said wells being arranged in a quincunx in this network and a second series of wells being used for production and likewise arranged in a quincunx, complementary to the first. The present invention also includes an assembly for drilling wells in a deep horizontal zone for working the process described above, characterized by the horizonal injecting and producing wells being arranged in quincuncial patterns within the networks formed in the successive vertical planes of the formation.
Advantageously, the superimposed reservoirs are essentially 10 meters thick and the rocks separating said reservoirs are 10 meters thick at most.
Finally, in a preferred embodiment, the distance separating two contiguous parallel horizonal sections in a given reservoir is essentially 100 m.
One specific embodiment of the invention will now be described in greater detail, and will make it easier to understand the essential features and advantages, it being understood that this embodiment has been chosen as an example that is not limitative.
BRIEF DESCRIPTION OF THE DRAWINGS
The assembly of drilling wells for carrying out the process of the invention is illustrated in the accompanying drawings wherein--;
FIG. 1 shows a longitudinal section through the formation, with wells with horizontal drains;
FIG. 2 shows a cross section through the formation along the plane of section A--A;
FIG. 3 shows the comparative hydrocarbon production curves as a function of time, for an ordinary well and a well worked according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a lengthwise section through a geological formation 1 comprising, at a depth, stratified reservoirs 2, 3, and 4 containing heavy hydrocarbons. These reservoirs are superimposed on one another and separated by rocks 5 and 6 composed of impermeable layers such as clay through which the hydrocarbon does not pass.
According to the present invention, it is desired to develop a process of recovery from these reservoirs by extraction to the surface.
In a preliminary step, wells 11, 12, and 13 are drilled, which, starting at the surface of the ground, have an initial practically vertical section, followed by an inclined or horizontal section extending into a reservoir in the formation, said wells being surmounted by drilling towers or derricks 10. Thus, a first well 11 is drilled so as to terminate in first layer 2, a second well 12 in second layer 3, and so on, each reservoir being provided with a horizontal drain.
To cover the entire surface of the formation in one longitudinal direction, a second series of wells 11', 12', and 13' is drilled behind first wells 11, 12, and 13 and surmounted by drilling towers or derricks 10'.
In normal applications of horizontal wells, the drains can reach lengths L extending horizontally for several hundred meters and for a non-limitative average distance of 500 meters.
Wells 11, 12, and 13 are drilled starting at a geographical point selected to allow their horizontal drains to be aligned practically parallel in the vertical direction, i.e. so that they are all practically perpendicular to corresponding derricks 10 and as shown in FIG. 2 are located within the same vertical plane--. However, the present invention could be used equally well if the drains were spread a few meters apart from this vertical direction, i.e. from the vertical plane--.
FIG. 2 shows a cross section of the formation along the plane of section A--A. In this figure we see the first series of wells 10, 11, and 12 with horizontal sections. This figure shows the openings of these wells and the shafts terminating at derricks 10. In a preferred non-limitative version, the three drains of wells 11, 12, and 13 are mutually perpendicular. This drawing includes arrows pointing upward or downward to indicate whether the wells are for injecting steam (downward-pointing arrows) or for production (upward-pointing arrows).
Well 11 serves as a steam injector when this steam enters the reservoir and diffuses heat energy which propagates in all directions, especially through rock 5.
When the heat energy reaches reservoir 3 immediately adjacent to reservoir 2 where it is being emitted, heating takes place in the zone adjacent to producing drain 12, so that extraction can begin.
This heat-diffusion phenomenon is shown for well 22, around which the progress of heating is represented by concentric circles 7.
It can be seen that well 22 acts on the two wells 21 and 23 located in each of the reservoirs in layer 2 above as well as layer 4 below.
Of course, the normal entrainment phenomena caused in reservoirs by displacement of fluid act as shown by horizonal arrows 8 and 9, but this action is relatively late and does not supplement the heat induction phenomena until a considerable time has elapsed.
Thus, in the plane of a vertical section through the formation, there is a network of wells, each link of which is composed of a horizonal drain, said network extending in two orthogonal directions, the first direction being that of the series of wells vertically below the geographical point, and the second direction being longitudinal at a given depth along a reservoir. Within this network, a first series of wells operated as steam injectors is arranged in a quincunx in this network, and a second series of producing wells is likewise arranged in a quincunx, in an arrangement that is complementary to the first series.
This type of network is formed in successive planes of the formation to cover the entire oil field.
To provide some idea of size, the present invention is used preferentially when the reservoirs have a thickness A, B, C on the order of 10 meters and when they are separated by rocks with a thickness d of at least 10 m.
Finally, drilling distance D is selected, separating the wells located in the same reservoir by a distance on the order of 100 m.
FIG. 3 shows theoretical curves representing the cumulative production of a well as a function of time T expressed in operating years.
Curve 15 is for a producing well as commonly used in the prior art, while curve 16 is for a producing well located in a network of steam-emitting wells and producing wells as described in the present invention.
It has been found that production practically doubles in the second year in comparison to the wells formerly used. After four years, production is still double.
Finally, if we compare the curves at tangents with identical slopes (points 17 and 18) corresponding to the end of exploitation of the well, we find that a gain G T in time of one year has been achieved. Production on curve 18 ends after 5 years instead of 6 years as before.
With this gain in time, production reflects a gain G p corresponding to practically 15% of the cumulative production when the well is shut down.
The present invention applies in an especially favorable manner to the production of heavy hydrocarbons with densities between 0.93 and 1. For lower densities, using the process according to the present invention is less useful because the natural flow of the producing well is fast enough not to require external excitation like heating.
Of course, the invention is not limited in any way by the details specified in the above or by the details of the specific embodiment chosen to illustrate the invention. All manner of variations can be made in the specific embodiment described above as an example and in its structural elements without thereby departing from the scope of the invention. Thus, the latter includes all means comprising equivalent techniques for the means described, as well as their combinations. | A process for the assisted recovery of heavy hydrocarbons from an underground formation having a plurality of superimposed reservoirs for the hydrocarbons involves arranging horizontal sections of a plurality of wells so that a first well of a first series of wells extend into a reservoir and is located essentially vertically below a horizontal section of a second well located in an immediately adjacent reservoir, with the first well being used as a steam injection well and the second well being used as a hydrocarbon-producing well. | 4 |
FIELD OF THE INVENTION
[0001] The present invention relates to a process for the recovery of gallium from Bayer process liquors. Bayer process liquor is obtained from alumina industries and contains 450 g/L Na 2 O, 80 g/L Al 2 O 3 and 190±20 ppm of gallium. This invention will be useful in recovering metallic gallium from alumina industries, where gallium is present in the Bayer process liquor.
BACKGROUND OF THE INVENTION
[0002] Gallium is relatively abundant in nature but is not naturally concentrated. It is usually associated with aluminium in bauxite, nephelines and other ores. It has been also found in the ashes of certain kinds of ore. A major resource for the recovery of gallium is gallium bearing aluminium ores. The spent caustic solution from Bayer process, which is recycled, builds up the gallium concentration approximately to 200 ppm. Gallium is also obtained from the iron mud or residues that results from the purification of zinc sulphate solutions, in zinc production.
[0003] Gallium is recovered from Bayer process liquors by the process of
[0004] 1) direct electrolysis
[0005] 2) solvent extraction and
[0006] 3) ion exchange.
[0007] In the direct electrolysis process the gallium is generally recovered from Bayer process liquor by using mercury cathode. The drawbacks of this process are that when the organic content of the Bayer process liquor is high, the process becomes uneconomical due to low current efficiency and the use of the mercury is highly toxic to the environment. In such case preliminary separation of gallium with partial enrichment is carried out either by fractional precipitation (by neutralising the alkali with CO 2 ) or by removal of part of alumina by addition of lime and subsequent recovery of gallium by passing CO 2 . Reference is made to Bhat and Sundarajan, J. Less Common Metals, 1967, 12 pp: 231-238 wherein they have studied the solvent extraction method for the recovery of gallium from the enriched fraction as mentioned above. In this study about 50% of the alumina content of the liquor was precipitated as calcium aluminate by the addition of lime. The gallia and the remaining part of alumina were then co-precipitated by neutralising the alkali with CO 2 . This fraction containing about 0.6% Ga 2 O 3 was dissolved in hydrochloric acid and maintaining free acid at 3N. From this solution gallium was extracted by contacting an equal volume of 20% TBP and then recovered by back extraction with water. Gallium was precipitated with ammonia and the gallium hydroxide dissolved in 10% sodium hydroxide, and from which gallium metal was finally obtained by electrolysis using a gallium cathode and nickel anode. The gallium thus obtained was found to be 99% pure with an overall recovery of 90%. The drawbacks are the destruction of the alumina liquor which cannot be recycled back into the Bayer process.
[0008] Reference is made to Varadhraj et al., J. Appl. Electrochemistry, 1989, 19(1) pp: 61-64, wherein their investigations on the effect of organics employing linear stripping voltammetry techniques on glassy carbon electrodes in alkaline gallate solutions revealed the inhibitory effect of those compounds on the electrodepositions of gallium and hence on gallium recovery from aluminate solutions.
[0009] Reference is made to Dorin and Frazer, J. Appl. Electrochemistry, 1988, 18(1), pp: 134-141, wherein they have electrodeposited gallium from a synthetic Bayer process liquor comprising 4.5M NaOH/0.2M Na 2 CO 3 /0.3M NaCl and 1.7M Al(OH) 3 . The deposition was in part controlled by the mass transfer and in part by electron transfer step. Heavy metal impurities, such as Fe and V, usually found in these liquors, promote the hydrogen evolution reaction, completely inhibiting gallium production if present above certain critical concentrations, i.e. 3 ppm for Fe and 30 ppm for V. The drawbacks of the above mentioned two process are that the direct electrowinning of gallium from Bayer process liquor is not possible if the liquors contain iron and vanadium above their critical limits.
[0010] Reference is made to Leveque and Helegorsky, International Solvent Extraction Conference 1977, pp: 439-442, wherein the solvent extraction of gallium from concentrated Bayer process liquors using Kelex 100 was first reported. The organic phase was made up of 8.5 vol % of Kelex 100, 10 vol % of n-decanol and 81.5 vol % of kerosene. When this organic phase was contracted with a Bayer process liquor containing 75 g/L of Al 2 O 3 , 194 g/L of Na 2 O and 270 ppm of Ga, at 1.0:1.0 aqueous to organic phase ratio at 28° C., 80% of gallium was reported to be extracted in 3 h. The drawback of this process is the slow kinetics where the time taken to reach equilibrium was reported to be 3 h.
[0011] Reference is made to Pesic and Zhou. J. Metals, 1988, 40 pp: 24-26, wherein 80% of gallium extraction was obtained in 4 h from synthetic aluminate solutions containing 200 ppm of gallium. The drawback of this process is again slow kinetics. Reference may be made to Borgess and Mason wherein they have studied the solvent extraction of gallium from a weak Brazilian Bayer process liquor containing 110 ppm Ga, 16-25 g/L of Al 2 O 3 and 108-120 g/L of Na 2 O using 10.0 vol % of Kelex 100, 5.0 vol % of Versatic 10, 8.0 vol % of n-decanol and 77 vol % of kerosene and showed 90% recovery in 2 min. Though the problem associated with the slow kinetics of gallium extraction is overcome by incorporating Versatic 10 acid into the organic phase the process is not addressed the actual recovery of the gallium metal.
[0012] Reference is made to Swift, J Am. Chem. Soc, 1924, 46, 2375-2381, wherein from 6.0 M HCI gallium can be loaded selectively onto diethylether over virtually any probable co-existing elements excepting germanium and Fe(III). The presence of HCl promotes formation of HGaCl 4 which is extracted by solvation, but above 6.0M HCl competition with acid extraction reduces its recovery. Ether extraction was preceded by removal of heavy metal impurities and Fe(III) reduction through aluminum. The drawback of this process is its non selectivity to Fe (III), where aluminium is added to reduce Fe(III) to Fe(II).
[0013] Reference is made to Mihalov, I and Distin, P. A. Hydrometallurgy, 1992, 28, 13-27, wherein a detailed review on the solvent extraction of gallium from HCl solutions was given where several organic agents such as organophosphorous compounds, D 2 EHPA, carboxylic acids, ketones, alkyl amines and quarterly ammonium salts are discussed with respect to their extractability of gallium from HCl solutions. Gallium is extracted as GaCl 4 into quarterly ammonium salts (eg., Tricapryl mono methyl ammonium chloride—Aliquat 336) by anion exchange. The extraction of gallium is rapid and increases with increasing chloride concentration.
[0014] U.S. Pat. No. 5,204,074 teaches the recovery of gallium from basic aqueous solutions thereof such as Bayer liquors by contacting with a medium comprising a gallium extractant. The gallium values are transferred to the extractant which is then contacted with a basic aqueous solution and the gallium then back-extracted into the basic aqueous solution. This solution is then further contacted with a second medium containing a gallium extractant to transfer the gallium values thereto. The gallium enriched second medium is then contacted with a second aqueous solution which can be either acidic or basic to back-extract the gallium values. This is then directly electrolyzed to produce gallium.
[0015] U.S. Pat. No. 5,008,016 discloses the recovery of gallium by liquid/liquid extraction from basic aqueous solutions using an organic phase containing a substituted hydroxyquinoline and caustic soda.
[0016] U.S. Pat. No. 4.169,130 discloses a the recovery of gallium by liquid/liquid extraction with a water immiscible organic phase comprising an organic solvent and a dissolved water insoluble substituted hydroxyquinoline. The recovery of gallium is conducted under inert atmosphere.
[0017] The above patents suffer from the disadvantages that the processes are kinetically slow, require inert atmosphere thereby not being feasible on large scale and low purity of gallium recovered.
OBJECTS OF THE INVENTION
[0018] The main object of the present invention is to provide a process for the recovery of gallium from Bayer process liquors which obviates the drawbacks as detailed above.
[0019] It is another object of the invention to provide a process for the recovery of gallium from Bayer process liquors which results in good yield and purity of gallium.
[0020] It is a further object of the invention to provide a process which results in economical and eco-friendly recovery of gallium from Bayer process liquors.
SUMMARY OF THE INVENTION
[0021] Accordingly the present invention provides a process for the recovery of the gallium from Bayer process liquors which comprises
[0022] i) contacting the Bayer process liquor with an organic phase comprising 10-15 vol % 7(4-ethyl-1-methyloctyl)-8-hydroxyquinoline, 10-15 vol % iso-decanol, 3-7 vol % versatic 10 and 63-77 vol % kerosene at 1.0:1.0 aqueous to organic phase ratio at room temperature,
[0023] ii) separating the loaded organic and aqueous phases and scrubbing the said organic phase with 5.0-6.5 M HCl at 1.0:1.5 organic to aqueous phase ratio and stripping with 1.0-2.0M HCl solution at 1.0:1.0 organic to aqueous phase ratio and adding concentrated HCl to the said strip liquor to raise required acid concentration to 4M,
[0024] iii) adding 1.0-5.0 g/100 ml aliphatic carboxylic acid to the above stripped solution, and contacting the stripped solution obtained in step (ii) with an organic phase having a composition of 10-20 vol % tricaprylmethyl-ammonium chloride, 5-15 % iso-decanol and the balance kerosene at 1.0:0.25 aqueous to organic phase ratio at room temperature, for about 2 min followed by separation of organic phase,
[0025] iv) scrubbing the said organic phase with 5.0-6.5M HCl at 1.0:1.0 organic to aqueous phase ratio and stripping with 3.5-4.5M NaOH solution at 1.0:0.25 organic to aqueous phase ratio,
[0026] v) filtering the solution to remove iron hydroxide and electrowinning the strip solution using copper as cathode and stainless steel as anode in a voltage range from 1.80 to −2.2V to recover gallium
[0027] In an embodiment of the invention the strip liquor of step (i) above has an element composition of:
[0028] Gallium=365.00-371.00 ppm
[0029] Aluminium=250.0-300.00 ppm
[0030] Vanadium=9.0-12.0 ppm
[0031] Iron=150.0-180.0 ppm
[0032] Manganese 1.8-2.5 ppm
[0033] In another embodiment of the invention, the organic chemicals used such as (7-(4-ethyl-1-methyloctyl)-8-hydroxyquinoline, Ascorbic acid, iso-decanol, versatic 10, aliquat 336 and kerosene are of commercial grade and inorganic chemicals such as HCl, NaOH are of analytical grade.
[0034] In another embodiment of the invention the aliphatic carboxylic acid is selected from the group consisting of tartaric acid, citric acid and ascorbic acid.
DETAILED DESCRIPTION OF THE INVENTION
[0035] The Bayer process liquor which gets recycled in the Bayer process after alumina precipitation and vanadium sludge precipitation gets enriched in gallium content normally to the extent of 200 ppm This Bayer process liquor before being sent to bauxite leaching is subjected to stage-I solvent extraction using organic solvent mixture-1 at 1.0:1.0 aqueous to organic phase ratio for 10 min in order to extract gallium from the Bayer process liquor. After this step the organic and aqueous phases are separated and the Bayer process liquor is subjected to bauxite leaching. The gallium loaded organic phase whose composition is described above also contains alumina and soda to the extent of 1900 and 1950 ppm, respectively. These impurities are subjected to scrubbing using 5.0-6.5 M HCl at 1.0:1.5 organic to aqueous phase ratio by mixing for 3 min. In this step the alumina and soda are removed into the scrub solution, whereas the loaded gallium remains in the organic phase with an average loss of 1% into the scrub solution. The scrubbed organic phase is then subjected to stripping step where 99% of the loaded organic phase is stripped using 1.0-2.0M HCl solution at 1.0:1.5 organic to aqueous phase ratio by mixing for 3 min. The gallium stripped organic phase is recycled for stage I solvent extraction. The gallium loaded strip HCl solution is brought to the desired HCl concentration by adding concentrated HCl solution and ascorbic acid is added at a rate of 1.0-5.0 g/100 ml of strip liquor.
[0036] Thus prepared strip liquor is subjected to stage II solvent extraction step. The stage II solvent extraction is conducted at an aqueous to organic phase ratio of 1.0:0.25 by mixing for 2 min. After this step the organic and aqueous phases are separated and the organic phase is subjected to scrubbing with 5.0-6.5M HCl at 1.0:1.0 organic to aqueous phase ratio by mixing for 2 min. After this step the organic and the aqueous phases are separated and the organic phase subjected to stripping with 3.0-5.0M NaOH solution at 1.0:1.0 organic to aqueous phase ratio by mixing for 3 min. All the gallium loaded into the organic phase II is stripped into the caustic solution. After the organic and aqueous phase separation the organic phase is recycled for further stage II extraction. The iron present in the strip liquor is precipitated as iron hydroxides and this precipitate is removed from the aqueous strip liquor by filtration. Thus obtained iron free gallium enriched strip liquor is subjected to electrolysis using copper cathode and steel anode at a potential of −1.95 to −2.05V. Finally gallium is deposited on the copper cathode and collected as a metal with >99% purity. After the deposition the caustic strip liquor is recycled for further stripping of gallium from the organic phase of stage II solvent extraction.
[0037] The uptake of gallium by Kelex 100 proceeds through a cation exchange mechanism in which hydroxyl ions are liberated as shown below:
Ga(OH) 4 − +3HQ( o )=GaQ 3 ( o )+OH − +3H 2 O
[0038] where HQ is Kelex 100 having chemical name (7-(4-ethyl-1-methyloctyl)-8-hydroxyquinoline) and (o) indicates the organic phase.
[0039] The extraction of gallium from HCl solutions onto Aliquat 336 (chemical name tricaprylmethyl-ammonium chloride) is as per the following reaction:
GaCl 4 − +R 3 R′NCl( o )=R 3 R′NGaCl 4 +Cl − ( aq )
[0040] In the process present invention iron is suppressed from being extracted in IInd stage extraction using Aliquat 336. The suppression of iron was studied with the additions of aliphatic carboxylic acid such as tartaric, citric and ascorbic acids and out of these ascorbic acid was found to be successful in suppressing iron from being extracted.
[0041] Approximately 85% of iron can be arrested from being extracted into Aliquat 336 by adding desired amount of ascorbic acid to 50 ml of strip liquor. The remaining 15% iron got precipitated when the loaded Aliquat336 was contacted with 4.0 M NaOH solution for the purpose of stripping and therefore 100% iron removal from the final strip liquor from which gallium is produced by electrowinning.
[0042] Novelty of the present invention is the use of the organic solvent containing Kelex 100, iso-decanol, versatic-10 and kerosene in stage-I extraction which increases the kinetics of the extraction process and also use of aliphatic carboxylic acid such as ascorbic acid in the stage-II extraction reduces the iron impurity in the gallium.
[0043] The following examples are given by way of illustration of the present invention and therefore should not be construed to limit the scope of the present invention.
[0044] Solvent extraction (both stage I and stage II) experiments were conducted by preparing the organic phase of the required composition and mixing it thoroughly with the Bayer process liquor in a glass breaker using a mechanical stirrer at 1000+10 rpm. The glass beaker was immersed in water bath to maintain uniform temperature through out the experiment. All other inorganic chemicals used in this study were of analytical grade and standard laboratory glassware was used for all experimental purposes.
EXAMPLE-1
[0045] 100 ml of Bayer process liquor was stirred with 100 ml of organic solvent-I containing 10% Kelex 100, 10% iso-decanol and 5% versatic-10 and 75% of kerosene for 10 min. and then allowed to settle. The aqueous and organic phases were then separated using separating funnel and a sample was collected from the aqueous solution for gallium analysis. During this stage the organic phase extracts sodium, aluminium and other impurities along with the gallium. Therefore, scrubbing of the organic phase was conducted with 6.0 M HCl at 1.0:1.5 organic to aqueous phase ratio. During this stage gallium remains in the organic phase, which is then stripped with 1.5M HCl at 1.0:1.5 organic to aqueous phase ratio. The gallium concentration in the strip liquor was analysed and was found to be 340 ppm, giving 85% recovery into the strip liquor. This strip liquor containing 1.5 M HCl was made up to .4.0M HCl by adding 14 ml of concentrated HCl to 100 ml of strip liquor along with 2.0 g /100 ml of ascorbic acid for iron suppression. After adding the HCl solution the concentration of gallium is reduced to 298.0 ppm. This was then subjected to solvent extraction stage II for further purification and concentration. The organic phase used in stage II was made up of 15 vol % of Aliquat 336, 10 vol % of iso-decanol and 75 vol % of kerosene. The aqueous to organic phase ratio was maintained at 1.0:0.25 and was mixed thoroughly with the stage I strip liquor for 2 min and then both the phases were separated using separating funnels. The loaded organic phase was scrubbed with 6.0M HCl at 1.0:1.0 organic to aqueous phase ratio and subjected to stripping with 4.0M NaOH solution at 1.0:0.25 organic to aqueous phase ratio. Gallium in the final strip liquor was found to be 4.75 g/L. 100 ml of this strip solution obtained from the second stage extraction was subjected to electrolysis at −1.8 v using EG&G potentiostat/galvanostat model No.273 and gallium was electrowon onto a copper cathode. Stainless steel anode and saturated calomel electrode as reference electrode were used in the electrowinning process. Metallic gallium of about 95% is obtained from the electrolysis of the strip liquor obtained from the IInd stage extraction.
EXAMPLE-2
[0046] 100 ml of Bayer process liquor was stirred with 100 ml of organic solvent I containing 12% Kelex 100, 10% iso-decanol and 10% versatic-10 and 68% of kerosene for 10 min. and then allowed to settle. The aqueous and organic phases were then separated using separating funnel and a sample was collected from the aqueous solution for gallium analysis. During this stage the organic phase extracts sodium, aluminium and other impurities along with the gallium. Therefore, scrubbing of the organic phase was conducted with 6.0 M HCl at 1.0:1.5 organic to aqueous phase ratio. During this stage gallium remains in the organic phase, which is then stripped with 1.5M HCl at 1.0:1.5 organic to aqueous phase ratio. The gallium concentration in the strip liquor was analysed and was found to be 345 ppm, giving 86% recovery into the strip liquor. This strip liquor containing 1.5M HCl was made up to 4.0M HCl by adding 14 ml of concentrated HCl to 100 ml of strip liquor along with 2.0 g/100 ml of ascorbic acid for iron suppression. After adding the HCl solution the concentration of gallium is reduced to 300 ppm. This was then subjected to solvent extraction stage II for further purification and concentration. The organic phase used in stage II was made up of 12 vol % of Aliquat 336, 10 vol % of iso-decanol and 78 vol % of kerosene. The aqueous to organic phase ratio was maintained at 1.0:0.25 and was mixed thoroughly with the stage I strip liquor for 2 min and then both the phases were separated using separating funnels. The loaded organic phase was scrubbed with 6.0M HCl at 1.0:1.0 organic to aqueous phase ratio and subjected to stripping with 4.0M NaOH solution at 1.0:0.25 organic to aqueous phase ratio. Gallium in the final strip liquor was found to be 4.5 g/L .100 ml of this strip solution obtained from the second stage extraction was subjected to electrolysis at −2.2 v using EG&G potentiostat/galvanostat model No.273 and gallium was electrowon onto a copper cathode. Stainless steel anode and saturated calomel electrode as reference electrode were used in the electrowining process. Metallic gallium of about 97% purity is obtained from the electrolysis of the strip liquor obtained from the IInd stage extraction..
EXAMPLE-3
[0047] 100 ml of Bayer process liquor was stirred with 100 ml of organic solvent I containing 12% Kelex 100, 10% iso-decanol and 5% versatic 10 and 73% of kerosene for 10 min. and then allowed to settle. The aqueous and organic phases were then separated using separating funnel and a sample was collected from the aqueous solution for gallium analysis. During this stage the organic phase extracts sodium, aluminium and other impurities along with the gallium. Therefore, scrubbing of the organic phase was conducted with 6.0 M HCl at 1.0:1.5 organic to aqueous phase ratio. During this stage gallium remains in the organic phase, which is then stripped with 1.5M HCl at 1.0:1.5 organic to aqueous phase ratio. The gallium concentration in the strip liquor was analysed and was found to be 380 ppm, giving 95% recovery into the strip liquor. This strip liquor containing 1.5M HCl was made up to 4.0M HCl by adding 14 ml of concentrated HCl to 100 ml of strip liquor along with 2.0 g/100 ml of ascorbic acid for iron suppression. After adding the HCl solution the concentration of gallium is reduced to 333 ppm. This was then subjected to solvent extraction stage II for further purification and concentration. The organic phase used in stage II was made up of 15 vol % of Aliquat 336, 10 vol % of iso-decanol and 75 vol % of kerosene. The aqueous to organic phase ratio was maintained at 1.0:0.25 and was mixed thoroughly with the stage I strip liquor for 2 min and then both the phases were separated using separating funnels. The loaded organic phase was scrubbed with 6.0M HCl at 1.0:1.0 organic to aqueous phase ratio and subjected to stripping with 4.0M NaOH solution at 1.0:0.25 organic to aqueous phase ratio. Gallium in the final strip liquor was found to be 5.32 g/L .100 ml of this strip solution obtained from the second stage extraction was subjected to electrolysis using EG&G potentiostat/galvanostat model No.273 and gallium was electrowon onto a copper cathode. Stainless steel anode and saturated calomel electrode as reference electrode were used in the electrowinning process. Pure metallic gallium of more than 99% is obtained from the electrolysis of the strip liquor obtained from the IInd stage extraction. In a continuous electrowinning plant it is normal practice to maintain a buffer of 40 g/L of gallium to run the plant with reasonable current efficiency and therefore the low concentration of gallium which is 5.32 g/L obtained in the final strip liquor will not cause any current efficiency problems during electrowinning step.
[0048] The main advantages of the present invention are
[0049] The organic phases used in this process can be recycled.
[0050] Metallic gallium obtained is of high purity
[0051] The process is environmentally friendly. | The present invention relates to a process for the recovery of gallium from Bayer process liquors. Bayer process liquor is obtained from alumina industries and contains 450 g/L Na 2 O, 80 g/L Al 2 O 3 and 190±20 ppm of gallium. The present invention utilizes an organic and inorganic phase for a two stage separation process to recover gallium with high purity. | 2 |
RELATED APPLICATIONS
NONE
BACKGROUND OF THE INVENTION
The invention is directed to the field of energetic materials known as poly(N-nitro) dodecane cage compounds and processes to prepare these materials. In particular this invention relates to hexa(N-Nitro),hexaazatetracyclic dodecane compounds which are described in IUPAC nomenclature as 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo-[5.5.0.0 5 ,9.0 3 ,11 ]dodecanes. The parent compounds and corresponding skeleton structures have the common name of isowurtzitane. The skeletons are abbreviated as --HISW; the hexanitrohexaazaisowurtzitanes are abbreviated as HNIW; the compounds and the use of the nomenclature are described in U.S. Pat. No. 5,693,794.
The HNIW compounds have a density of about 2.0 g/cc and six N-nitro groups per molecule. The compounds are polymorphic with at least four crystal forms: alpha, beta, gamma and epsilon. Epsilon HNIW has the highest density. Typically the processes of production will result in the alpha HNIW which is then converted to the epsilon HNIW, see CA,Vol 128, NO.128, No.14, p.595, 167451w, Kawabe, et al, 1998. The product in the epsilon crystal form is preferred for use in energetic compositions such as propellants and explosives. The energetic compositions with HNIWs are described as Cl-20 containing compositions in U.S. Pat. Nos. 5,712,511, and 5,739,325. The preferred usage is to apply this term to the epsilon form of HNIW.
There are problems in developing compositions which utilize the epsilon HNIW as an energetic material. The intermediate HNIW crystal forms need to be available in high purity and yield. The processes for producing the intermediates need to be simplified. The reactions and reaction media need to reduce or eliminate the presence of side reactions, shock-sensitive impurities, other impurities and oxygenated -ISWs so that a high purity, shock insensitive epsilon HNIW crystal can be obtained. It is to these ends that this invention is directed.
BRIEF SUMMARY OF THE INVENTION
This invention provides nitration of N-substituted isowurtzitanes (NHISW) with a nitrating agent consisting essentially of concentrated nitric acid. The reaction is conducted at an elevated temperature and a solid product is recovered that is principally gamma HNIW. A novel process for converting the gamma HNIW to epsilon HNIW is also disclosed. Among the advantages of the invention are that the nitrating agent is highly concentrated nitric acid, a minimum molar excess of nitrating agent to HNIW can be used, the reaction temperatures can be increased and the yield of product is increased and the reaction reaches substantially total completion in a relatively short time.
The nitration processes of this invention directly produces a solid product that can be recovered as essentially pure gamma HNIW and the levels of impurities and side products in the product are reduced or eliminated. The conditions of the nitration can be controlled so that common impurities such as oxa-ISW and dioxa-ISWs and incompletely nitrolysed compounds such as PNAIW are present in only negligible amounts in the nitration media. Reaction promoters and solid proton donor resins can also be used in carrying out the practice of the invention. The optimum reaction conditions are such that yields of gamma HNIW are above about 99%. The invention allows the minimization of costs of production and the costs of waste disposal.
BRIEF DESCRIPTION OF THE FIGURE
The FIGURE contains representative FTIR spectrum of the gamma HNIW product of Example 1 and the reported spectrum from technical publications for gamma HNIW.
DETAILED DESCRIPTION OF THE INVENTION
In the practice of the invention, the principal reactants are the NHISW compounds and the concentrated nitric acid which are reacted at an elevated temperature for a relatively short time. The temperature needs to be at or above the onset temperature for the reaction to occur. As the reaction proceeds, an isolatable solid product will be formed. Significant amounts of HNIW crystals can be recovered from the product. They will be worked up so that a very pure form of gamma HNIW is obtained. This is converted to the epsilon HNIW.
The NHISW has N-substituents which are known as facile leaving groups; these can withstand the rigorous nitration conditions without destruction of the --ISW skeleton and allow the multiple nitrations at the N-sites which ultimately form the hexanitro compound. In effect the NO2 groups replace the facile leaving groups. While there are many potential facile leaving groups for the NHISWs, the problems of cost and availability are such that only a relatively few compounds are presently accessible. Generally, in terms of availability and efficacy, a preferred group of NHISWs are the compounds with skeletons whose N-substituents are selected from up to 6 hydrogen atoms, up to 6 alkyl groups, up to 6 acyl groups, up to 2 alkylaryl groups, up to 2 NO groups, and up to 2 NO2 groups. In terms of current availability, the particularly preferred substituents for the NHISW are hydrogen, acetyl, formyl, benzyl, NO,and NO2 groups. Exemplary compounds include tetraacetyldiformyl isowurtzitane (TADF), tetraacetyldibenzyl isowurtzitane (TADB), teraacetyldinitroso isowurtzitane and tetraacetyldinitro isowurtzitane (TADN).
The concentrated nitric acid reactant is historically considered to be HNO3 and H2O. The exact mechanism of the reactant is still poorly understood in complex nitration systems such as the present invention. The reactant will have an initial concentration of from about 90 to about 98% HNO3. As the reaction proceeds, the NO2 is consumed and the concentration of HNO3 becomes reduced. If the concentration falls to about 70%, the concurrent increase in the concentration of water is sufficient for attacks and decompositions of the HNISW at elevated temperatures. This leads to the oxa and dioxa ISWs and other impurities in the reaction media. In this invention, the reaction condition variables of elevated reaction temperature, choice of coreactant NHISW compounds, shortened reaction time and minimum molar excess of HNO3 can be selected to provide for high yields of gamma HNIW with minimum or undetectable impurities even though the concentration of water is increasing. The concentrated nitric acid is preferably at least about 90% HNO3 and may be from about 95 to about 98% HNO3. Typically, the generally available 95% and 98% HNO3 grades are used.
Another advantage of this invention is that it employs simplified reaction procedures and advantageous ratios of reactants. The molar excess of HNO3 to NHISW is desirably is kept to a minimum. This appears to reduce impurities; it reduces the operating cost of the process and it reduces the waste disposal and clean up costs. The range of the molar excess can be from about 4 to about 6. This corresponds to about 24 to about 36 moles of HNO3 per mole of NHISW. It can also be appreciated that the minimum molar excess of nitrating agent is an advantage whether the reaction is conducted under either batch or continuous operations.
It is preferred to put the concentrated HNO3 in the reactor and then to add the NHISW compound in small portions and mix until a clear solution is formed. The mixing temperature should be in the range of about 20 to 25 degrees C. The temperature of the solution is gradually increased until a temperature is reached where the nitration of the NHISW will begin; this is considered the onset temperature and will be about 75 degrees C. for the conditions set forth in the Examples. It is the elevated temperature of the solution at which appreciable conversion to the HNISW occurs. In some cases, the onset temperature may be at about 80 degrees C. The upper limit for the elevated temperature will in theory be the boiling point of the reaction media. A lower temperature is practical. The Examples show that a temperature range of from about 100 to 115 degrees C. has given good results. A reaction temperature of about 115 degrees C. has been able to produce a gamma HNIW at very high yields and of very high purity with short reaction times. The exact temperature range will also be affected by the presence of solid reaction promoters and solid proton donor resins. These can increase recoverable gamma HNIW, lower onset temperature or decrease impurities.
The overall time of heating for the reaction to reach substantial completion varies within wide limits. The range is from about 3.5 to about 19 hours. It has been found that a short reaction time in the range of from about 3.5 to about 4 hours is adequate to achieve substantial completion of the reaction. Reaction times in the range of 12 and 12.5 to 19 hours have also been used which allow for a margin of safety in reaction control. Under batch reaction conditions, the system can reach about 100% completion.
The invention is also novel in the sense that it appears to be the first time that gamma HNIW is reported to be made by the use of concentrated nitric acid and elevated temperature. The presence of the gamma HNIW from the reaction is indicated by the formation of a white, solid material in the reaction medium that be worked up and identified as gamma HNIW from its FTIR spectrum. The work up and recovery of the HNIW follows the established practices in this field. When the reaction has reached the target degree of completion, the reaction medium will have a suspended solid in the reaction liquid. The system will be cooled to room temperature. Then, the materials will be poured over crushed ice. The solids will be recovered by filtration and examined with NMR. The solids represent the isolatable solid material of the reaction. The NMR will indicate the percentage of HNIW and the percentage of other materials. If oxa or dioxa ISWs are present, they can be identified as such. Further purification steps such as washing can be performed as discussed in Example 1. The high yield and high purity of the gamma HNIW of this invention is demonstrated by the FIGURE. The FTIR spectrum in the FIGURE for the product of the process is substantially as is shown by recognized technical literature publications for gamma HNIW.
The range of HNIW in the isolatable solid material from the reaction media is in the range of at least about 30% to about 99%. Intermediate contents of HNIW in the isolatable solids material were at least about 60%, 80% 95%, 97% and 98% are noteworthy. This HNIW is usually recovered and worked up by aqueous procedures By this stage, as well as in earlier stages, the HNIW can be principally in the gamma form. The gamma form can be converted to epsilon HNISW.
The practice of the invention is illustrated by the following Examples.
EXAMPLE 1
Part A
Preparation of Gamma HNIW by Nitration with 98% HNO3 at Elevated Temperature
Part A of Example 1 illustrates the nitration reaction of the invention in which the reaction is carried out with 98% HNO3 as the nitrating agent, TADF as the NHISW and where the reaction temperature is about 115 degrees C. It demonstrates that the isolated, solid HNIW material that is converted to a gamma HNIW that has an FTIR spectra substantially the same as that reported for the pure gamma HNISW. Part B describes the conversion of the gamma HNIW to the epsilon HNIW. The yields and the purity of the gamma and epsilon HNIW are very high.
A three-necked, round-bottomed flask was fitted with a reflux condenser, a moisture-guard tube, a thermometer, and a stirrer. The equipment was placed in an oil bath. The nitrating agent was concentrated nitric acid in an amount of 15 ml at 98% HNO3 which was placed in the flask. The TADF was added in small portions at such a rate that the temperature of the reaction stays between about 20 and 25 degrees C. The media was stirred while the TADF went into solution. A total of 5.0 gm was added and the solution was clear.
After the addition was completed, the temperature of the reaction mixture was gradually elevated by heating the flask until a reaction temperature of about 115 degrees C. was reached. This temperature corresponds to an external oil bath temperature of 125 degrees C. As the reaction continued, a white, solid material began to form. As the reaction was allowed to continue, additional white solid material was formed. The total heating time was 4.5 hours.
When the reaction approached 100% conversion, the reaction mixture was cooled to room temperature and poured over crushed ice. The white, solid material was recovered by filtration and washing three times with cold water. It was air dried and formed a free-flowing powder. An FTIR spectrum of the product was taken and is shown in the FIGURE. There is a comparison with the published FTIR spectrum for pure gamma HNIW. It can be seen that the product produced by this invention is gamma HNIW of very high purity. The yield of gamma HNIW based on the amount of TADF was consistently in the range of from above about 90% to about 99%.
Part B
Polymorphic Transformation of
Gamma HNIW to Epsilon HNIW
This is a novel process to convert either alpha, beta or gamma HNIW to epsilon HNIW. Mixtures of the crystal forms may also be used. A 1.0 g. sample of gamma HNIW prepared as described above was mixed with 1 ml. Of acetic acid and 4.0 ml of ethyl acetate; this formed a solution. 0.030 gm of seed crystals of epsilon HNIW were added to the solution. Then, 24 ml of hexane were added dropwise to the mixture. A solid material precipitated. The mixture of liquid and solids was stirred for about 30 minutes and filtered. The solid filtrate was washed with hexane and dried to yield epsilon HNIW in quantitative yield. The epsilon HNIW crystals were free-flowing, white solids. If the acetic acid is not present, epsilon crystals are not obtained even with extreme standing times. The acetic acid allows the crystallization media to produce fine quality, epsilon HNIW.
EXAMPLES 2-5
In the following Examples 2-5, variations of the nitration conditions and the concentrated nitric acid reactant of Example 1 were used to demonstrate the effects of time, temperature (reported as internal reaction temperature), reaction promoters and reactant ratios on product yield, product purity and production of side products, by-products, impurities, etc.
The general procedure follows Example 1. The specified amount and type of concentrated nitric acid is put into the flask. The NHISW is added in small portions at such a rate that the temperature of the reaction stays between about 20 and 25 degrees C. while stirring the solution. After the addition is completed, the temperature of the reaction mixture is gradually elevated by heating until the target temperature is attained. The reaction is continued for the desired period of time. The reaction medium is separated into liquids and solid. The isolated solid material is examined by NMR. The approximate % of HNIW can be estimated from the NMR as well as the approximate % of other products. If oxa or dioxa isowurtzitanes were to be present, this can be noted.
(a) 300 mg of TADF were used to form a solution in 1 ml of 98% HNO3. The elevated temperature was about 80 degrees C. and the total time of heating was 4 hrs. A white solid product from the reaction was isolated. It was found to contain about 30% of HNIW and about 70% other products.
(b) The same conditions as in 2(a)above were used except the elevated temperature was at about 115 degrees C. The isolated material was found to contain at least about 98% HNIW and there was less than about 2% other products.
(c) The same conditions as in 2(a) above were used except the amount of TADF was 1,000 mg and the amount of 98% HNO3 was 1.5 ml. The elevated temperature was about 115 degrees C. and the total time of heating was 4 hrs. The isolated material contained about 80% HNIW and about 20% side products. Oxa and dioxa isowurtzitane impurities were among the side products; this indicates decomposition of HNIWs by water.
(d) The same conditions as in 2(c) above were used except the amount of TADF was 1,000 mg and the amount of 98% HNO3 was 2.0 ml. The isolated material was about 80% HNIW and the side products were about 20%. Oxaisowurtzitane was present in the side products; this indicates the decomposition of HNIWs by water.
(e) The same conditions as in 2(c) above were used except the amount of 98% HNO3 was 3 ml. The isolated material was about 98% HNIW and the side products were below about 2%.
(f)The same conditions as in Example 2(e) were used except the amount of materials were tripled. The isolated material was about 98% HNIW and the side products were below about 2%. This shows that the reaction conditions can be scaled up in a predictable manner to produce suitable products.
EXAMPLE 3
95% HNO3 as Nitration Agent
This Example illustrates the use of 95% HNO3 as the concentrated nitric acid for the reactions of this invention. It also illustrates that the molar ratios of reactants can be varied to minimize the amount of excess concentrated nitric acid required to drive the polynitration reaction and that the reaction conditions can be scaled up.
(a) 300 mg of TADF were used to form a solution with 1 ml of 95% HNO3. The elevated temperature was about 115 degrees C. and the total time of heating was 4 hrs. The content of the isolated material was in the range of from above about 95% HNIW to about 97% HNIW and the corresponding range for side products was from about 3% to below about 5%.
(b) 1,000 mg of TADF were used to form a solution with 3 ml of 95% HNO3. The elevated temperature was about 115 degrees C. and the total time of heating was 4 hrs. The content of the isolated material was in the range of from above about 95% HNIW to about 97% HNIW and the corresponding range for side products was from about 3% to about 5%.
(c) The conditions of 3(b) were duplicated except the amounts of materials were tripled. The content of the isolated material was in the range of from above about 95% HNIW to about 97% HNIW and the corresponding range for side products was from about 3% to about 5%. This illustrates that the conditions of the reaction can be scaled up.
EXAMPLE 4
Nitration with Concentrated Nitric Acid and Optionally Solid Reaction Promotors
This Example illustrates that the reaction temperature has a strong effect on the onset of nitration of the NHISWs with the concentrated nitric acid and that at suitable temperatures the nitration can be conducted either with or without solid reaction promoters, such as solid proton donor resins.
(a) 300 mg of TADF were used to form a solution with 3 ml of 98% HNO3. 1300 mg of a solid resin having sulfonic acid groups in the proton form, available as Nafion-H, were also added to the solution. The elevated temperature was about 70 degrees C. The range of heating times were from about 12 to about 15 hours. No identifiable amount of HNIW was seen in the isolated material. The side products were not identified. This illustrates that nitration did not occur at this reaction temperature even in the presence of the concentrated nitric acid and the reaction promotor.
(b) The same conditions as in 4(a) above were used except the elevated temperature was at about 75 degrees C. The isolated material was about 60% HNIW and the side products were less than about 40%. The higher temperature reached the onset of nitration to form the HNIW product. The successful production was very evident.
(c) The same conditions as in 4(a) above were used except the elevated temperature was at about 80 degrees C. The isolated material was about 80% HNIW and the side products were less than about 20%. The higher temperature produced more product. The successful production of solid white product was very evident.
(d) The same conditions as in 4(a) above were used except the elevated temperature was at about 100 degrees C. The isolated material was at least about 95% HNIW and the, side products were less than about 5%. Again, the higher temperature produced even more product.
(e) The same conditions as in 4(a) above were used except the elevated temperature was at about 115 degrees C. The isolated material was at least about 99% HNIW and the presence of other products can be described as nil.
EXAMPLE 5
Nitration with Varying Amounts of Solid Reaction Promoters at Same Reaction Temperature
This Example illustrates the combined benefits that can occur from the optimization of reaction conditions which use the preferred temperature, the type and amount of concentrated nitric acid and the presence of the reaction promotor.
(a) 300 mg of TADF were used to form a solution with 3 ml of 98% HNO3. No reaction promotor was used. The elevated temperature was about 115 degrees C. The range of heating times were from about 12 to 15 hours. The isolated solid material was at least about 98% HNIW and the other products were present in amounts of less than about 2%. This is substantially a repetition of Example 2(f).
(b) The same conditions as in 5(a) above were used except a solid reaction promotor in the form of solid sulfonic acid resin in the protonated form, Nafion-H, was also present. It was used in an amount of 25 mg. The isolated solid material was at least about 98% HNIW and the other products were present in amounts of less than about 2%.
(c) The same conditions as in 5(b) above were used except the amount of Nafion-H was 100 mg. The isolated material was at least about 99% HNIW and there were no identifiable amounts of other products.
(d) The same conditions as in 5(b) above were used except the amount of Nafion-H was 300 mg. The isolated solid material was at least about 99% HNIW and there were no identifiable amounts of other products.
The detailed description and Examples are provided to illustrate specific modes of carrying out the invention.
The invention is intended to cover such equivalent practices, materials and supplementary techniques as would be evident to those skilled in the field and that the scope of the claims should be interpreted to that end. | Processes and compositions for nitration of N-substituted isowurtzitane compounds with concentrated nitric acid at elevated temperatures to form HNIW and recovery of gamma HNIW with high yields and purities. Polymorphic conversion of HNIW crystals to epsilon HNIW crystals is also disclosed. | 2 |
This is a Continuation-in-Part of application Ser. No. 343,852, filed Mar. 22, 1973 now abandoned.
This invention relates to a method for separating garment portions that were originally manufactured in the form of a continuous web, and particularly to a method for removing the separating thread between neighboring knitted garment portions which are produced in a continuous web by a continuous knitting machine.
BACKGROUND OF THE INVENTION
Knitted garments are manufactured in separate portions, such as the body of a sweater or shirt, the collar, sleeve, cuff, etc. Complete garments are thereafter stitched together from various portions. A continuously operating knitting machine is programmed to produce a continuous web comprised of succeeding identical garment portions, e.g. a continuous web of knitted shirt collars, with succeeding garment portions being joined by a knitted-in separating thread.
Each garment portion has a finished and an unfinished edge. The finished edge is the one exposed to view when the garment portion is assembled in the completed garment, e.g. the edge of a cuff. The unfinished edge is sewn into the seam joining the garment portion to the remainder of the garment.
A knitting machine may use one or more spools or supplies of yarn or thread. A predetermined number of rows of a particular color or type of yarn or thread is knitted. Then the knitting machine may switch to another type of yarn or thread and continue the knitting process. Upon completion of a single garment portion in a continuous web of garment portions, the knitting machine is programmed to finish the edge of the garment portion in the web to make the finished edge so that it will not unravel. Then, without interrupting the continuous knitting process, the machine switches to what is known in the art as a spearating thread, and one or more rows of separating thread is knitted. Thereafter, the machine switches back to the original yarn and begins knitting the next garment portion in the web starting at the edge of that portion which is raw and unfinished. Each succeeding garment portion in the web is thus joined to the respective preceding garment portion by separating thread. The continuous web is wound on a beam and the beam is brought to where garments are to be made.
Before garments are manufactured from the garment portions produced in the continuous web, the separating thread between adjacent garment portions must be removed. It is conventional to manually remove the separating thread by pulling it out and/or unraveling the separating thread, or to perform this removal and/or unraveling procedure semi-automatically, with an operator holding the garment while the separating thread is pulled out.
Because of time delays associated with the manual or semi-automatic steps in removing separating thread, it is also known to form the separating thread out of a material that is soluble in water or other appropriate fluid. The web of garment portions is passed through heated, even boiling, water or other appropriate solvent and the correspondingly selected separating thread is melted and dissolves away leaving the separate, but not wet and perhaps somewhat damaged, garment portions. An appropriate drying procedure is thereafter needed, requiring expenditure of extra time and effort.
Finally, it is known to form the separating thread of a material that deteriorates in the presence of heat. Attempts have been made to develop a dry process using such a separating thread formed from a specially developed synthetic filament. With the application of hot air or radiant heat, the thread would melt or materially deteriorate so as to separate the knitted garment portions. This has led to the significant problem of the presence of a separating thread residue on the finished (upstream) edge of all of the separated garment portions. In addition to eliminating the residue on the finished edge of the garment portion, it is advantageous to use a synthetic material for the separating thread whose melt temperature is lower than that of the yarn used to form the garment portion. This would, of course, be a problem in connection with garment portions of synthetic filament yarns.
SUMMARY OF THE INVENTION
It is the primary object of the present invention to temporarily join garment portions in a web by use of a separating thread and to thereafter simply and effectively remove the separating thread.
It is another object of the invention to remove the separating thread without leaving any residue of separating thread on the finished edge of a garment portion.
It is further object of the invention to realize the foregoing objects using any of a wide variety of commercially available, low temperature filaments as separating thread.
These and other objects will become apparent from the following summary and detailed descriptions of the invention.
In accordance with the invention, any of a wide variety of separating threads for knitting garment portions together is selected. The separating thread must have the characteristic that it melts or is otherwise destroyed in the presence of heat and it is preferable that the separating thread melt or destruction temperature is below the temperature which will adversely affect the knitted garment portions which the separating thread joins. For example, a low temperature nylon filament manufactured and sold by Monofilament Company of Waynesboro, Virg. Va. be used. A conventional continuous web of garments portions, preferably knitted garment portions, is formed. The garment portions are conventionally joined by separating thread, e.g. by a continuous knitting process of the garment portions and the separating thread. The web is arranged so that the finished edge of each garment portion is its trailing or upstream edge and the unfinished or raw edge of the garment portion is its leading or downstream edge as the web is moved.
The web passes through an oven wherein the web is subjected to a continuous blast of hot air. The blast of hot air is oriented to impinge upon the web moving through the oven in the downstream direction and more particularly the blast of hot air impinges upon the web obliquely to its direction of extension and movement through the oven and generally in a downstream direction. The heated air is directed at an oblique angle to the direction of travel of the web through the oven so that the heated air initially impinges mostly on the upstream or trailing finished edge of the garment portion. With a slight tensioning of the web, the separating thread is parted at the finished edge of each garment portion, leaving all of the filament residue on the unfinished edge of the succeeding garment portion. The unfinished edge of each garment portion is eventually seamed together with an adjoining other garment portion on the garment. The filament residue is tucked in and incorporated into the finished seam, so that it cannot be seen. Means are provided for moving the continuous web into the oven, for moving the web and garment portions through the oven, for tensioning the web as it is subjected to hot air and for collecting the separated garment portions after they exit from the oven.
There is coordination of the precise type of separating thread filament used, its thickness, the length of the path of travel of the web while it is being exposed to the blast of hot air, the time of exposure of each section of the web to hot air, the heat sensitivity of the yarn used in manufacturing the garment portions, and the temperature of the air impinging upon the web moving through the oven all so as to desirably melt the separating thread and to clear all residue of separating thread from the trailing, finished edge of each garment portion. The foregoing method and apparatus are beneficial in that the garment portions are kept dry because no liquid or solvent is needed to remove the separating thread.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing will be better understood from the following description of the accompanying drawings, in which:
FIG. 1 is a schematic perspective view showing an apparatus in accordance with the invention for practicing the method in accordance with the invention.
FIG. 2 is a representation of the connection by means of separating thread between two neighboring garment portions before the garment portions have been operated upon in accordance with the invention.
FIG. 3 is a representation of the same garment portions after they have been operated upon in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
By means of a standard knitting machine (not shown), a continuous web 10 of garment portions 12, 14, and the like have been knitted. Turning to FIG. 2, garment portion 12 has a downstream or leading edge 16 which is its unfinished edge. Garment portion 14 has an upstream or trailing edge 18 which is its finished edge that should be free of any residue of separating thread.
At least one row of separating thread 20 has been knitted between unfinished edge 16 and finished edge 18. There may may be additional rows of separating thread for enlarging the space between edges 16 and 18 for better access to hot air or for other reasons, although the more separating thread that is used, the more residue that remains after operating upon the web according to the invention. The separating thread is formed of a low temperature filament, e.g. low temperature nylon.
Returning to FIG. 1, web 10 of attached garment portions is unwound, and is then moved toward the heating means described below by belt 22, which belt is driven by roller 24 and is carried on idler roller 26. Roller 24 and belt 22 cooperate with and rotate with roller 28. Roller 28 is biased toward roller 24 to engage the web at the nip of the rollers and pull web 10 therebetween, thereby to move the web of garment portions into heating zone 30. Rollers 24 and 28 are driven by conventional means to rotate past each other at the same rate. In heating zone 30, garment portions 32, 34 move over guiding and supporting roller 36 which is driven with, cooperates with and is biased against roller 38. Conventional drive means (not shown) drive rollers 36, 38 so that they move at the same rate at their nip or point of contact. Preferably, the rate of motion at the nip of rollers 36, 38 is slightly greater than the rate of movement at the nip of rollers 24, 28 so as to draw the neighboring garment portions, here shown as 32, 34, apart.
In heating zone 30 is located hot air blowing heating means 40, which comprises a conventional fan 42 that blows heated air through a conduit 44 in which there is a heating means 46 to heat the flowing air. The now heated air moves into duct 48 which has an outlet 50 of sufficient width to extend at least across and preferably a little wider than the greatest width portion of garment portions 32, 34 and which has a length along the direction of extension of the garment portions sufficient to allow hot air to be blown against the web to melt the separating thread 20 between neighboring garment portions to the desired extent.
What is significant about duct 48 and its outlet 50 is the orientation thereof with respect to the web as the web moves past the duct. The duct is oriented so that the blown hot air is directed at an angle transverse to the web, oblique to the direction of extension of the web as it moves past the duct so that the air is directed to impinge directly upon the finished edge of a pair of cooperating edges that have been joined by separating thread. In the usual situation illustrated herein, the finished edge of a garment portion, such as portion 14, is its upstream or trailing edge 18 and duct 48, 50 is therefore oriented to deliver hot air obliquely downstream and, therefore, principally against the finished edge of each garment portion. As the web is moving in the downstream direction, it is preferable that the blast of air be obliquely downstream, in cooperation with the direction of movement of web 10 through the heating zone. In an alternate arrangement, it may be more preferable to have the web arranged so that the finished edge of each garment portion is its downstream or leading edge rather than its upstream or trailing edge and the oblique orientation of the hot air duct would, therefore, be altered so that the duct is blowing air upstream, rather than downstream.
FIG. 3 depicts what will happen to garment portions 12, 14 after they have moved past duct 48, 50. The heated air from duct 48, 50 is directed to cause the separating thread 20 to melt and deteriorate on the finished, trailing edge 18 of garment portion 14. At the same time, cooperating rollers 36, 38 are drawing the leading or downstream garment portion 14 away from the trailing garment portion 12. The direction of the heated air cooperates with the movement apart of the garment portions to leave the residue of separating thread 20 on the unfinished edge 16 of the trailing garment portion 12. The separation of the garment portions is now completed and the residue is all away from the finished edge 18 of garment portion 14.
Returning to FIG. 1, the now separated garment portions 52, 54, etc. fall or are deposited upon conventional conveyor 56, which is operated by rollers 57, 58 which are conventionally driven (by means not shown) and which carry the garment portions to and deliver them to receptacle 60. The garment portions are now ready for further processing into complete garments.
There has just been described one embodiment of an apparatus for and of a method for automatically removing any heat destructible separating thread that is between adjacent garment portions in a continuous web of such portions, without any manual operations being required in the separating procedure, and without having to wet or otherwise adversely affect the condition of the garment portions and leaving the finished edge of each garment portion free of residue. the foregoing is accomplished by providing a separating thread of heat disintegratable material, moving the continuous web of garment portions held together by separating thread past the heating zone and blowing heated air at an oblique angle to the web and oriented to impinge directly upon the finished edges of each garment portion, thereby to disintegrate the separating thread while freeing the finished edge of each garment portion of any residue.
Although the present invention has been described in connection with a preferred embodiment thereof, many variations and modifications will not become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims. | Knitted garment portions are manufactured in a continuous web of such portions, with each garment portion being attached to the succeeding garment portion in the web by a separating thread that is intended to be subsequently removed; in accordance with the invention, the separating thread is made of a heat sensitive filament which melts or is destroyed when heat is applied, thereby separating the garment portions; heated air is directed at an oblique angle to downstream motion of the web and melts the separating thread on the trailing edge of each garment portion. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus and a process for bonding dry metallic powder to a substrate and more particularly to impact extruding particles to form a continuous thin film on a metallic surface.
The use of impact or peen bond coating techniques has been limited in scope and to laboratory environments as a result of the failure to implement tribology in a practical apparatus for field use. Other bonding methods, such as binders or adhesive merely hold together a mass of discontinuous particles on a given surface. Pressures required for extrusion of the coating material into a continuous coat can destroy the bond between the coating material and the surface of the substrate.
2. Description of the Prior Art
The most pertinent prior patent is believed to be U.S. Pat. No. 3,758,976. This patent discloses a nozzle for blasting a powdered metal mixed with a media against a surface to be coated but does not disclose requirements for utilizing the process in commercial applications. U.S. Pat. No. 4,552,784 utilizes substantially the same steps as the above patent but substitutes rapidly solidified metals to form the powder mix.
Other prior patents include:
U.S. Pat. No. 4,312,900 disclosing a method of treating sliding metal contact surfaces which pits the workpiece surface to be coated, buffs a solid lubricant into the pits and reblasts to partially cover the pits followed by power buffing the surface.
U.S. Pat. No. 3,574,658 disclosing a method of producing a dry-lubricated surface which coats a glass bead media with lubricant for blasting the workpiece surface leaving the lubricant bonded to the surface being coated. Since the beads break down during the process the entire mix must be discarded after one use.
Exploitation of these patents has not been generally achieved on a commercial basis possibly for the reason problems to be overcome in utilizing the process commercially was not set forth, particularly for the peening type methods or for the reason many coating materials disclosed do not require a peening effect since they may be blasted on and leave a coating smear on a substrate.
This invention is distinctive over these patents by providing a virgin surface on a substrate by removing all contaminants and microscopic burrs and maintaining a desired coating/media ratio combined with atmospheric control when impingement burnishing to bond particles on and form a continuous film on a substrate surface. The peen plating process of this invention produces a unique effect not disclosed in these patents in which the peening not only forms a plating function but also a burnishing operation promoting parallel crystal orientation of the solid lubricant employed. Without such parallel orientation, the coating is more subject to corrosion and a shorter wear life by rapidly wearing which also results in a higher coefficient of sliding friction.
SUMMARY OF THE INVENTION
The device to be coated is cleaned to remove any oils, gases, or other coatings. It is then blast cleaned with fine abrasive (100-325 mesh) such as aluminum oxide to remove surface contaminants such as oxides and to expose the base material anchor pattern. Water vapor content in the blast area, media and compressed gas are reduced to predetermined levels.
After cleaning the device, exposure to normal atmosphere must be kept at a minimum until coated. The coating operation uses a high pressure gas to impel a mixture of media and a powdered coating material against the surface to be coated. The coating is impinged or adheres to the surface and is further bonded to the surface and extruded into a continuous film by the peening effect of the media. Humidity and water vapor control is important.
Both the cleaning and the coating machines are similar in function to common air or wheel blast cleaning machines. The requirements in commercializing thin process coating are different from standard equipment in the following ways:
The humidity of the blast atmosphere must be controlled. Water content of the compressed air source and the media must be minimized. Condensation on the interior cabinet walls must be eliminated. Extra fine abrasive and micron size coating materials must be recycled at a minimal loss while having extra ventilation for reasonable operator vision. Mixes of media and coating materials of different densities must maintain consistent ratios in the blast area.
The principal object is to provide an apparatus and a method of forming a continuous coating bonded to the surface of a substrate by adherence and peen burnishing of a metallic powder impelled at high velocity and by molecular attraction of the metallic powder to the substrate surface.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow diagram of the steps of cleaning a workpiece for coating;
FIG. 2 is a flow diagram of the steps of coating a workpiece;
FIG. 3 is a mechanical diagram of a workpiece coating apparatus illustrating one type of material feeder;
FIG. 4 is a fragmentary mechanical diagram of a coating machine illustrating an alternative type of material feeder;
FIG. 5 is a fragmentary vertical cross sectional view, to a larger scale, of the coating feeder;
FIG. 6 is an exploded perspective view, with parts omitted for clarity, of the feeder components; and,
FIGS. 7, 8, 9 and 10 are fragmentary perspective views, to a different scale, illustrating alternative embodiments of the feeder apparatus.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Like characters of reference designate like parts in those figures of the drawings in which they occur.
In the drawings:
The steps of practicing the invention include producing a virgin surface on the area of a metallic workpiece to be coated in which all contaminants and microscopic burrs are removed. A blast cabinet 10 of substantially conventional design is provided and with the workpiece, not shown, in place the cabinet is preheated and humidity control achieved by a control 12. The cabinet reservoir 14 is prefilled with abrasive cleaning material and heated within the cabinet. Dry compressed gas 16 supplies the abrasive cleaning material to a blast gun which impacts the abrasive material on the area of the workpiece to be cleaned as in step 18. During and following the cleaning the abrasive material is returned to the reservoir with the fine particles thereof being removed, as at 20, while the cleaned workpiece is removed from the cabinet and transferred to the coating cabinet 30 (FIG. 2) as at 22.
Referring to FIG. 2, which illustrates the steps of coating the workpiece, the coating machine 25 (Fig.), as presently described, or any substantially conventional coating machine, not shown, is employed to impact the coating material on the substrate to bond the coating particles thereto. The coating machine cabinet 30, including a reservoir 32, filled or containing a mixture of coating and media has the humidity thereof controlled by a humidity control 34. Dry compressed gas 36 supplies the coating and media to a blast gun, not shown, which is directed toward the workpiece to coat and burnish the precleaned surface thereon in the step 38. Following the film coating of the workpiece, the coating and media is recycled to the reservoir. The coating process mechanically bonds a malleable powder to the substrate and extrudes the bonded particles into a continuous coating which resists flaking and can only be removed by abrasive or external chemical erosion. Such mechanical bonding is preferred in many situations as opposed to electroplating which has a tendency for hydrogen embrittlement and its accompanying safety and environment problems. The mechanical bonding is more easily achieved by impelling the powdered metal at the substrate at high velocity wherein bonding occurs due to adherence to the substrate's surface profile (anchor pattern) and in the present invention is partially due to molecular attraction. An example of anchor pattern bonding involves a metallic powder with low shear characteristics, such as lead, aluminum, copper or tin which leave a smear when impelled against a substrate surface having a suitable anchor pattern. Such an anchor pattern is a discontinuous surface of peaks and valleys which the softer metal will cling to. An example of molecular attraction coating is molybdenum disulfide.
Molybdenum disulfide in a lubricant grade is refined from mineral molydenite and is commonly referred to by its trade name Molysulfide.
Molybdenum disulfide (MOS 2 ) is a crystal structure comprising layers arranged with the sulphur atoms on each side of the molybdenum atoms (S--Mo--S). Sulfur has a strong affinity for metallics so when the molybdenum disulfide is impelled onto a surface with enough pressure for reasonable surface contact, a molecular bond is achieved.
Both methods require that the substrate be free of any contaminants, coatings or chemical derivatives such as oxides or other products normally formed in its environment. While a bond may occur to the oxide any difference in expansion or compression rate of the oxide vs. the substrate will cause a fault in the coating and allow corrosion to undermine the coating. Care is also required in the selection of the cleaning media so that it will not initiate a chemical change or leave a residue on or impinge on the surface.
Liquid solvents can be used to remove hydrocarbons. Solvents used prior to blast cleaning must not leave a film. Abrasive blast cleaning is an effective way to remove dry, brittle contaminants.
The preferred cleaning abrasive is aluminum oxide. Silicon carbide, glass beads, polycarbonate grit, steel and iron abrasives, flint and mill slag abrasives can be used where they will not impinge into the surface or leave a film.
The abrasive must be large enough to fracture or abrade away the large areas of contamination and also contain enough fine material to scour the microscopic pores of the substrate. A polished substrate may require a wider abrasive size range to provide a more pronounced anchor pattern. When there is little molecular attraction between the coating material and the substrate and the shear coefficient is high to resist the extruding process, an extra surface preparation step such as etching the surface, may be necessary prior to the abrasive cleaning procedure.
Once the final cleaning cycle begins extreme care must be exercised to avoid the return of contaminants until the coating process is complete. The virgin substrate will have a strong affinity to react with atmospheric constituents or liquid or solid particulate during handling. In demanding situations dry inert atmospheres may have to be used. Less demanding requirements will need control of water vapor and any corrosive gases along with clean and careful handling during processing. Careless scaring of the surface can cause a starting point for coating failure.
Selection of coating materials must not only depend on purpose and design but also on substrate, purity, and size range. Generally, the coating material should be softer than the substrate. A harder coating material can be impinged into a softer substrate with this process but trying to form a continuous coating will be difficult because the substrate will deflect under the pressure of the impacting extrusion process causing fractures in the coating. Size is important to be able to more easily nest in the substrate's pores and the void areas. Generally small sizes are preferred depending on availability, cost and pyrophoric tendency. Purity of a coating material is important due to coating defects caused by tramp elements or processing chemicals.
The impact extrusion process will transform a mass of bonded particles or smears from the coating material into a continuous film. The process is accomplished by impelling a media against the bonded particles to force it deeper into the substrate's surface profile and spread it into a thin film. The extrusion process and the coating process can and is preferred be simultaneous with a barrage of coating material and impact media being hurled at the substrate. As the coating material clings to the surface, the impact media increases the bonding and begins the flattening and spreading process. To avoid hindering the coating process, the media must not contaminate the virgin surface of the substrate, exceed the coating material's plastic strength or tend to abrade away the developing film. It is preferred that the processing be combined so that the media may loosen any weakly bonded material and replace it with firmly bonded particles. It may be necessary to follow the combined process with a purely peening process to finally blend a continuous film.
Selection and sizing of the impacting media depends on the coating and substrate materials and finish desired.
The preferred impact media is steel or stainless steel shot if surface profile requirements permit. Conditioned polycarbonate or nylon media can be used for fine surfaces. Iron abrasives, glass beads and other silica based abrasives are not recommended because of their short life. Aluminum, copper, brass and zinc abrasives leave competitive smears and should be used only on special applications.
Any coating materials can be used that are dry powders and have the above described tendency toward molecular attraction, impingement, cladding or smearing. Precautions must be taken when the material has strong pyrophoric tendencies.
Mass, hardness and durability are important in selecting the type of media. The combination of mass, hardness and durability at a given impelling velocity determines the resulting change in the surface finish of the substrate. If the coating material is soft and pliable then the media can be on the soft side. On typical applications the size of the media is two to three times the size of the cleaning abrasive and the coating material. Generally it is not desirable to greatly modify the substrates' surface profile and therefore a small media is used. A variance of the surface profile is discussed hereinbelow in an example. Size affects the time required for coverage and the impact energy. One standard SAE size steel shot may have three to four times as many particles per pound as the next larger size. A diameter ratio of 2:1 can give an impact energy ratio of 8:1. A harder media is more efficient in transferring the energy of the larger mass.
The combination of durability and hardness is also important to coating integrity. The proper mass and size selection cannot produce a desired impact if the energy is lost in the disintegration of the media upon impact. Also the spent abrasive is difficult to remove from the coating/media mix causing the mix to be discarded early, increasing processing costs. The fractured media also produces sharp edges that tend to abrade the coating away. The desired shape of the media is spherical to produce a smoother, more uniform coating. Some media has long life because it is soft and leaves a smear on the clean substrate inhibiting proper coating bonding.
Controlling contamination also applies to new media. Many durable metallic medias are covered with an oxide due to processing and exposure to the atmosphere. Prior to use the media should be cleaned and surface contamination removed. It is advisable to coat the clean media with the intended coating material to reduce corrosion before use.
The cleaning and the coating processes are similar to blast cleaning and peening processes and must be housed in equipment to contain the materials and to control the environment. Coating and abrasive cleaning materials are costly and should be recycled to minimize processing costs. Since many of the applications will require manually directed processing, the internal machines environment will have to maintain reasonable visibility. Useable suspended material will have to be captured and returned for reuse. Inert dry atmospheres may be required for some application but common work can be accomplished in relatively low humidity environments. Desiccant dryers or heaters can be used to reduce the water vapor content of the internal atmosphere of the stored coating or abrasive materials. Compressed air used for blasting must be clean and dry. Absorption of water vapor from the equipment must be minimized.
The cleaning machine can use a common suction air blast nozzle and a suction pick up regulator. Most common reclaimers are not efficient with the very small abrasive used so the pick-up point for the exhaust ventilation line is placed in the top of the cabinet in a plenum chamber to catch only the air-borne fines. A cyclone reclaimer is placed between the cabinet and the dust collector to save any useable fine abrasive.
Common media accelerating devices can be used such as air blast nozzles or centrifugal blast wheels to impel the materials in the cleaning and coating processes. It is essential, however, that devices are used to insure the mix of coating material to media remains consistent. The flow characteristics of the coating material vs. the media will be different due to the density, size and shape of each constituent. Both throwing devices move air and will tend to separate the lighter material and leave the heavier behind. A positive feeding device must be used to prevent inconsistent mix ratios. Filters used to prevent escape of the materials must be cleaned continuously to avoid accumulation and change of the balance of the mix.
The coating machine 25 (FIG. 3) comprises a generally rectangular upright cabinet 30 defining a workpiece blast area 38, having a hopper or transparent observation panel 39 (FIG. 4), overlying a reservoir 32 containing a coating and media material mix 46 and having a closed circuit air flow means 48. The reservoir 32 is generally inverted frustoconical in general configuration for concentrating the heavy coating/media material 46 falling by gravity from the blast area 38 through the foraminated horizontal partition 50. The reservoir contains a gearmotor M driving mixing plates 52 and a coating/media feeder means 54 as more fully described hereinbelow. A heater 56 is interposed between the mixing plates 52 for humidity control from a control box, not shown. The preferred range of relative humidity is 35-45% which can be accomplished by heating the incoming air to 20°-30° F. over ambient or by using a desiccant dryer, not shown. Tubing 58 connected with the feeder means 54 and a source of dry gas 36 supplies a stream of the coating/media mix 46 to a manually controlled blast gun 59 disposed within the blast area 38 by a flexible tube portion 60. Access to the blast gun is obtained by protective hand/arm glove means 61 extending inwardly of the cabinet from hand/arm apertures 62 (FIG. 4). The blast gun may be supplied with a nozzle as described by the above named U.S. Pat. No. 3,754,976.
The air flow means 48 includes a motor driven blower or fan 63 mounted above the blast area 38 which generates a downdraft flow across the baffle 64 and adjacent the inner surface of the transparent panel 39 and toward the workpiece as indicated by the arrow 65. A downwardly projecting baffle 66 spaced forwardly of the blast area compartment back wall 68 forms an upwardly open air flow path 70 for air to exit the blast area and return to the fan through a common pulse-type cartridge system filter means 72, as indicated by the arrows 74.
The filter means 72 includes an open end sleeve-like filter cartridge 76 vertically disposed axially rearwardly of the back wall 68 and communicating, at its uppermost end, with the fan intake. The filter is within the upper portion of a coating and media fines collecting compartment 78, defined at its lower limit by downwardly converging walls having sufficient slope to avoid stress of non-circulating material, emptying into the reservoir through a partition wall bypass 80. The bottom of the filter is closed by an end plate 81 to insure filtering the air and its top end is partially restricted by an inwardly projecting annular flange 84. The purpose of the baffles 64 and 66 directing the air flow paths 65 and 74 is for creating a negative pressure in the blast area 38 to permit visual inspection of the workpiece during the coating process. The filter 76 is preferably a flexible wall type filter so that a motor driven shaker or air pulse means 86 mounted exteriorily of the cabinet 30 and having the outlet end portion of its discharge tube 90 disposed adjacent the opening of the flange 84 may generate a filter wall flexing action (expanding and contracting) for dislodging coating/media fines clinging to the wall surfaces of the filter.
The coating machine 100 (FIG. 4) diagrams a coating/media collecting and feeding system when steel shot is utilized as the media. A reclaim screw means 102 is disposed at the depending limit of the reservoir 32' for moving the coating mix 46 to a bucket elevator 104 depositing the mix in an elevated reservoir 32" containing a heater 56'. A screw feeder 106 in the depending limit of the reservoir 32" reblends the coating mix and feeds it to a suction gun.
EXAMPLE I
(Die Cast Molds)
Application of solid lubrication powders are good examples because they utilize many of the process features. The process can clean, deburr, and modify the surface to improve life or better retain other lubricants, provide a coating and burnish the coating into a thin, continuous film.
The process can be applied to cast die cast molds. The molds are exposed to hot aluminum and routinely have problems of soldering to the mold and mold release break down causing carbon build up and surface defects in the molded part. A coating of molybdenum disulfide by this process eliminates release problems and the build up of carbon by providing a stationary coating with a better wetting surface and microscopic pockets to improve the retention of the liquid mold release.
The powder selected for the coating process is a molybdenum disulfide with a size range of 1-100 microns and a median size of 30 microns. Purity level is +98% with molytrioxide, oil and acid number less than 0.3% per element. The dies having been thoroughly degreased before processing. The media to be used is a steel shot, -58 mesh +120 mesh, with a hardness range of 40-50 Rc. The shot was previously conditioned in a blast cleaning machine to remove surface scale and oxide and then tumbled with cleaners to remove any graphitic smear and then tumbled with molybdenum disulfide as a protective coating before compounding the coating mix.
The coating mix molybdenum disulfide and steel shot is placed in an airblast machine equipped with a heater in the coating mix reservoir or storage area to maintain a set temperature based on ambient humidity and capable of a range of 100°-250° F.
The coating machine can be equipped with various media handling designs. Since suction pick up does not produce sufficient line velocity to convey steel media a coating machine 100 may be utilized in which a bucket elevator 104 moves the mixture from the bottom of the cabinet reservoir 32' to the top of the cabinet. The screw feeder 106 provides flow control and reblends the mixture. The mixture is gravity fed to a suction blast gun or a blast wheel.
Another media handling approach is to use a pressure fed device. A common abrasive pressure blast tank, not shown, receives a load of abrasive which is then pressurized to the desired blasting pressure. The blast line is located below the tank and then the pressure is equalized, the abrasive flows by gravity into the blast line. The available tanks have no means of preventing segregation of the mix or an easy way of minimizing the water vapor of the mix during storage.
The preferred pressure feeding device 54 (FIGS. 4-10) is located at the bottom of the hopper or reservoir 32 for gravity feed and consists of a cylinder 110 angularly rotated horizontally by the drive shaft 111 of the gearmotor M having a top plate or lid 114 and a base plate or bottom 116 interconnected as by bolts 118. The cylinder is characterized by a circular row of vertical through bores 120 of selected diameter. The lid 114 is provided with an opening 122 adjacent its periphery to allow the mixture 46 to flow into the cylinder bores 120. Similarly the bottom 116 is provided with a companion aperture 124 adjacent its periphery but mismatched with the lid opening 122 as by 180°.
The bottom plate aperture 124 communicates with the air pressure supplied tubing 58 by a funnel-type sleeve 126. Layers of sealing material 130 having apertures cooperating with the plate apertures 122 and 124 are interposed between the cylinder 110 and the respective top and bottom plates for the purpose believed apparent.
Other embodiments of the pressure feeder may be utilized to handle material difficult to feed. For example, mixing or scraping blades 132 radially secured to the gearmotor shaft 111 (FIG. 7) and overlying the top plate 114 insure feeding the mix 46 into the aperture 122 and the cylinder holes 120. An auxiliary air line 134 within the reservoir 32 and communicating with the bottom plate discharge aperture 124 through the top plate (FIG. 8) insures forcible ejection of mix contained with each succeeding cylinder hole 120 into the tubing 58. Another solution for forcing the mix 46 out of the respective cylinder hole 120 as it is disposed over the discharge aperture is separating the tubing 58 at the position of the funnel sleeve 126 so that one end 136 of the tubing projects toward the axis of the respective cylinder holes when aligned with the bottom plate discharge 124 (FIG. 9). Alternatively the pressure in the cylinder holes 120 leaving the position of the discharge aperture 124 may be bridged to the cylinder holes 120 leaving the filling aperture 122 by an inverted U-shaped air line 138 (FIG. 9) mounted on the top plate 114.
Although the mix 46 is injected by the feeder 54 into the discharge tubing 58 in individual charges, the mix will spread itself in the pressurized stream into a homogeneous distribution as it travels through the tubing.
Once the mixture has been fed through the blast gun most of the mix 46 will fall to the bottom of the reservoir 32. The suspended material will be caught by the ventilation air filter 72. The fine particulate collection system must be capable of frequent cleaning and returning the material to the storage reservoir to avoid upsetting the balance of the mix.
The blast area 38 must be kept free of any strongly corrosive or oxidizing gases. To avoid vapor condensation on the inner surfaces of the metallic walls of the enclosure and to remove water absorbed by the dust collector cartridges, the equipment is run with the heat on prior to processing. Compressed air used for the pressure blasting or for the pulse type cartridge system must be oil and water vapor free.
Once the equipment has been preheated and the mold degreased, the mold is blast cleaned in the areas to be coated. All of the blast cleaning abrasive is removed from the mold. The mold should be moved to the coating machine with minimal hesitation to minimize oxidation of the substrate.
The coating is meant to be used in conjunction with the user's normal mold release agents to control situations beyond the normal limits of the agents.
Molybdenum disulfide maintains continuity up to 750° F. and can handle 400,000 psi loading, leaving no residue to discolor the work. The coating is stationary and will not migrate away from heavily loaded areas. The process can be used to produce microscopic indentations which serve as lubrication reservoir to better hold the lubrication under heat or pressure. The coating also provides a more easily wetted surface to draw liquid lubrication into difficult to reach areas.
The use of molybdenum disulfide also highlights a unique feature of the burnishing portion of the process. Its coating characteristics depend on how the crystal is attached to the surface. If the crystal is oriented with its base plane parallel to the surface, the coefficient of friction is 0.1 compared to 0.26 when sitting on an edge. The bond is also not as strong on the edge. In practice, the impacting media replaces or repositions the weaker bonds. Instead of extruding this through material, the burnishing effect slides the layers around to form a continuous film.
The strength of molybdenum disulfide also permits a variation of the process to incorporate a peening function. Burnishing becomes peening when the substrate surface is modified by repeated deflections causing a reshaping of the outer surface. The outer grain structure loses its symmetry as the metallic grains lengthen and become entwined. This surface modification lessens the tendency for cracking as the surface expands and contracts in heating and cooling.
Larger and harder steel shot than the above example can be used as the media to impact this peening function during the coating process to greatly extend the life of the mold. Current practice is to use peening to close up existing cracks in the molds. It is recommended that this new process be used with new molds to reduce the tendency of heat stress cracking and to routinely reprocess the molds before heat stress cracking is observed.
EXAMPLE II
(Tooling)
Another example is the use of the process in coating tooling with a solid lubricant such as molybdenum disulfide. The process is the same as the coating of the molds by preheating the equipment, controlling the atmosphere and completing the cleaning and coating operations.
The cleaning of a tool produces an additional feature. The ground cutting edge of a tool retains burrs. These burrs can fold over and cover part of the cutting edge. The cleaning process removes these burrs to leave a sharp cutting edge.
The molybdenum disulfide coating reduces the high friction and galling in areas when the chips are formed. Lowering friction reduces the build up of heat which tempers the tool. The chips that weld to the cutting edge of a broach cause unacceptable work finish. The burnishing effect can produce compressive stresses in fine cutting edges of tools like taps to substantially improve the fatigue strength of the teeth.
EXAMPLE III
(Bearings)
Another example of the benefits of the process is through the use of molybdenum disulfide coating of sliding bearing surfaces. All new bearing surfaces are not perfectly flat and are supported by the high points. Break-in periods with conventional lubricants result in the point loading of these peaks exceeding the lubricants capability and the metal to metal contact causes cold welding to occur. The cold welding results in these peaks being torn away, disrupting the surface, until the mating surfaces are flat enough to be protected by the strength of the lubricant's film.
This impact extrusion process can provide a continuous coat of molybdenum disulfide to prevent metal to metal contact in the peak areas. The film strength of molybdenum disulfide allows the bearing load to flatten the peaks into the surface rather than tearing them from the surface. This promotes run-in vs. wear-in.
As mentioned hereinabove and as believed obvious other dry lubricants may be used in this process such as tungsten disulfide or titanium disulfide. However the results obtained with molybdenium disulfide has been superior.
Obviously the invention is susceptible to changes or alterations without defeating its practicability. Therefore, I do not wish to be confined to the preferred embodiment shown in the drawings and described herein. | An apparatus and method for thin film coating a substrate comprising spraying a stream of molybdenum disulfide powder mixed with steel shot at a predetermined velocity against the substrate, the velocity being sufficient, when impacting the substrate, to bond minute plate-like particles of molybdenum disulfide to the substrate and form a friction reducing surface thereon. | 1 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to the field of calendaring software, and, more particularly, to providing an ability for a meeting initiator to specify during meeting establishment when respondents are to be prompted for attendance intentions and providing a way to automatically summarize and coordinate delivery of the intention responses.
[0002] In a calendaring application, a meeting initiator generally specifies meeting recipients when a meeting is established. Each of these recipients receives an electronic message constituting an invitation, which the recipients are able to add to their personal calendar. The meeting initiator can specify an optional field that provides feedback regarding whether recipients intend to attend the meeting or not.
[0003] One problem with current systems is that the intentions are prompted for at the time the meeting invitation message is received, which is at approximately the time the meeting was established within the calendaring application. Responses regarding attendance intentions provided upon invitation receipt can be relatively inaccurate.
[0004] That is, meetings are often established as soon as details are finalized, which can be significantly advanced from a time of the meeting event. Scheduling conflicts and other changes occurring between a time invitations to a meeting are sent and the actual meeting time will cause many who originally intended to attend to no longer be able to attend. Thus, intention responses received through conventional calendaring systems are relatively inaccurate.
[0005] Another problem with current systems is that intention responses are conveyed to the meeting initiator or a designated coordinator in a series of messages (often email messages) received at approximately a time that invitees respond with their intentions. Different invitees can send their responses days or weeks apart from each other. This results in a substantial manual effort for the meeting coordinator to group, track, and tally the responses. It is extremely easy for a message coordinator to miscalculate a set of intention responses for a meeting, especially when that coordinator is responsible for multiple meetings, which results in a sometimes overwhelming barrage of intention responses received over a chaotically distributed time period.
BRIEF SUMMARY OF THE INVENTION
[0006] One aspect of the present invention can include a system for managing meetings that permits and establishment of a prompt time and/or a tally time. The system can include a meeting management software program, a meeting data store, and a user interface. The meeting management software program can receive, manage, and store meeting specific information and to perform a set of programmatic actions related to the meeting specific information. The meeting data store can store digitally encoded information including the meeting specific information used by the meeting management software program. The user interface of the meeting management software program can include a meeting establishment view. The meeting establishment view can include a set of interface controls for establishing specifics for a meeting. The meeting establishment view can include a prompt time element that accepts input defining a configurable prompt time. The prompt time can represents a time when potential attendees are to be presented messages to indicate whether each potential attendee intends to attend the meeting. A programmatic trigger for the prompt time, referred to as the prompt trigger, can be established. The meeting management software can fire the prompt trigger and can perform a programmatic action related to the prompt time when a current time equals the prompt time.
[0007] Another aspect of the present invention can include a method, apparatus, computer program product, and system for delaying meeting intention responses. In this aspect, a meeting initialization request for a meeting can be identified. The meeting initialization request can specify a prompt time for attendance intentions. A programmatic trigger, referred to as a prompt trigger, can be established for the prompt time. A firing of this prompt trigger can occur when a current time equals the prompt time. At this time, at least one potential attendee for the meeting can be determined. A set of potential attendees is typically defined by the meeting initiator within the meeting initialization request. An intention message can be sent to the determined potential attendee responsive to a firing of the programmatic trigger. This intention message can be sent at a time close to the prompt time. The intention message can prompt the potential attendee to indicate whether the potential attendee intends to attend the meeting.
[0008] Still another aspect of the present invention can include a method, apparatus, computer program product, and system for summarizing intention responses. In this aspect, a meeting initialization request for a meeting can be identified. The meeting initialization request can specify a tally time for the meeting. The tally time can be a time at which a set of invitee provided intention responses are to be summarized, and/or received intention responses are to be conveyed to a meeting coordinator. A programmatic trigger, referred to as a tally trigger, can be established for the tally time. The tally trigger can fire when a current time equals the tally time. Metrics from a plurality of responses from potential attendees can then be compiled from the responses or otherwise generated. These compiled metrics can be used to create an expected attendance report. The expected attendance report can be sent or otherwise made available to a previously designated entity (e.g., the meeting initiator or other designated meeting coordinator).
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0009] FIG. 1 shows a set of time spaced scenarios that together illustrate a use of a calendaring system that permits a meeting initiator to establish a prompt time and a tally time for meeting attendance intentions in accordance with an embodiment of the inventive arrangements disclosed herein.
DETAILED DESCRIPTION OF THE INVENTION
[0010] The present invention permits a meeting initiator to designate a prompting time, when a meeting entry is established in a calendaring system. The prompting time can be a time when potential invitees are to be sent intention messages, which prompts the potential invitees to indicate whether they are going to attend the meeting. The prompting time can be any time, which will often be a time relatively close to the actual meeting time to be relatively accurate, yet which still provides sufficient advanced warning for a coordinator to make suitable adjustments based upon attendance estimates.
[0011] Additionally, the invention permits a tally time to be specified. The tally time can be a time when intention responses are automatically grouped, summarized, and results are conveyed to a designated coordinator (typically the meeting initiator). Any responses conveyed before the tally time can be held in a delay queue, as opposed to being conveyed to the coordinator's standard email inbox. The queuing can occur at the server side (e.g., email server), at the client side (e.g., email client), or at points in-between (e.g., middleware or network element queuing). When the tally time occurs, a programmatic routine can automatically summarize intention results. These results can be presented as an intention summary to the meeting coordinator, which reduces the burden of manual tallying of responses from the coordinator.
[0012] The present invention may be embodied as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.), or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, the present invention may take the form of a computer program product on a computer-usable storage medium having computer-usable program code embodied in the medium. In a preferred embodiment, the invention is implemented in software, which includes but is not limited to firmware, resident software, microcode, etc.
[0013] Furthermore, the invention can take the form of a computer program product accessible from a computer-usable or computer-readable medium providing program code for use by or in connection with a computer or any instruction execution system. For the purposes of this description, a computer-usable or computer readable medium can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-usable medium may include a propagated data signal with the computer-usable program code embodied therewith, either in baseband or as part of a carrier wave. The computer usable program code may be transmitted using any appropriate medium, including but not limited to the Internet, wireline, optical fiber cable, RF, etc.
[0014] Any suitable computer usable or computer readable medium may be utilized. The computer-usable or computer-readable medium may be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. Examples of a computer-readable medium include a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a rigid magnetic disk and an optical disk. Current examples of optical disks include compact disk-read only memory (CD-ROM), compact disk-read/write (CD-R/W) and DVD. Other computer-readable medium can include a transmission media, such as those supporting the Internet, an intranet, a personal area network (PAN), or a magnetic storage device. Transmission media can include an electrical connection having one or more wires, an optical fiber, an optical storage device, and a defined segment of the electromagnet spectrum through which digitally encoded content is wirelessly conveyed using a carrier wave.
[0015] Note that the computer-usable or computer-readable medium can even include paper or another suitable medium upon which the program is printed, as the program can be electronically captured, for instance, via optical scanning of the paper or other medium, then compiled, interpreted, or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory.
[0016] Computer program code for carrying out operations of the present invention may be written in an object oriented programming language such as Java, Smalltalk, C++ or the like. However, the computer program code for carrying out operations of the present invention may also be written in conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).
[0017] A data processing system suitable for storing and/or executing program code will include at least one processor coupled directly or indirectly to memory elements through a system bus. The memory elements can include local memory employed during actual execution of the program code, bulk storage, and cache memories which provide temporary storage of at least some program code in order to reduce the number of times code must be retrieved from bulk storage during execution.
[0018] Input/output or I/O devices (including but not limited to keyboards, displays, pointing devices, etc.) can be coupled to the system either directly or through intervening I/O controllers.
[0019] Network adapters may also be coupled to the system to enable the data processing system to become coupled to other data processing systems or remote printers or storage devices through intervening private or public networks. Modems, cable modem and Ethernet cards are just a few of the currently available types of network adapters.
[0020] The present invention is described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
[0021] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks.
[0022] The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
[0023] FIG. 1 shows a set of time spaced scenarios 120 , 140 , 160 that together illustrate a use of a calendaring system that permits a meeting initiator 102 to establish a prompt time 112 and a tally time 114 for meeting attendance intentions in accordance with an embodiment of the inventive arrangements disclosed herein. Scenario 120 denotes a set of activities occurring at a meeting initiation time; scenario 140 denotes a set of activities occurring at a prompt time 142 , and scenario 160 denotes a set of activities occurring at a tally time 162 . These times 122 , 142 , and 162 are to be flexibly interpreted to represent a span of time about a specific occurrence. Computing system delays, message delivery delays, and other delays expected in computing systems as well as application, administrator, and user imposed delays (through user specific settings, etc.) are to be expected and are to be considered within the span of time about the specific occurrence.
[0024] In scenario 120 at a meeting initiation time 122 , an initiator 102 can use interface 110 of computing device 104 to establish a new meeting. This interface 110 can include a prompt time element 112 for establishing a prompt time 142 and a tally time element 114 for establishing a tally time 162 . The prompt time 142 (input in element 112 ) can be a time when potential invitees are to be sent intention messages, which prompts the potential invitees to indicate whether they are going to attend the meeting. The tally time 162 (input in element 114 ) can be a time when intention responses are automatically grouped, summarized, and results are conveyed to a designated coordinator. For purposes of FIG. 1 , it should be assumed that the meeting initiator 102 is the designated coordinator. In real-world implementations, the initiator 102 can designate a set of one or more individuals at the meeting establishment time 122 to serve as designated coordinators.
[0025] Input to interface 110 can be recorded in a meeting initialization request 124 , which is conveyed to server 106 . The server 106 can include a calendaring server for managing calendar events and/or a communication server (e.g., an email server). Thus, server 106 can actually be implemented as a set or cluster of interrelated servers each having a combined functionality as indicated herein. The server 106 can determine a set of invitees 108 from the meeting initialization request 124 and can send invitation messages to each. Hence, each invitee 108 can receive through an interface 115 of a computing device 104 a meeting event notice. This notice can either be added to the invitee's personal calendar or not, at the invitee's option. It should be noted that the invitee 108 is not prompted regarding their intention to attend the meeting at this time 122 .
[0026] In scenario 140 at a prompt time 142 , an invitee 108 can be prompted through interface 116 of computing device 104 to indicate whether that invitee 108 intends to attend the meeting. Intention responses 144 can be conveyed to server 106 , where they are queued in data store 109 . The prompting for invitee 108 intentions can occur automatically based upon programmatic triggers established at initiation time 122 based upon values entered by the meeting initiator 102 into the prompt time element 112 .
[0027] In scenario 160 at a tally time 162 , a tally engine 164 can use responses from invitees 108 queued in data store 109 to generate a tally report 166 . This tally report 166 can contain a summary of expected meeting attendance. The report 166 can optionally include links to source documents (responses 109 ), a table showing each invitee's response information, projected attendance at a meeting (which can estimate attendance by non-responding invitees 108 ), and the like. In one embodiment, the actual responses 109 , which were previously delayed in data store 109 can also be conveyed to the initiator 102 . The initiator 102 can access this information through an interface 117 of computing device 104 . The prompting for invitee 108 intentions can occur automatically based upon programmatic triggers established at initiation time 122 based upon values entered by the meeting initiator 102 into the tally time element 114 .
[0028] In one embodiment, the various interfaces 110 , 115 , 116 , 117 shown in the scenarios 120 , 140 , 160 can be part of an integrated calendaring system, such as LOTUS NOTES. In another embodiment, the interfaces 110 , 115 , 116 , 117 can be interfaces from many different software applications, which are communicatively linked to permit them to exchange information. User interfaces 110 , 115 , 116 , 117 can be implemented as graphical user interface (GUIs), Voice User Interfaces (VUIs), multi-modal interfaces, small device interfaces, embedded device interfaces, and the like. The views shown for the interfaces 110 , 115 , 116 , 117 are for illustrative purposes only and other interface controls, arrangement, elements, and the like are to be considered within scope of the invention, which is not to be restricted to those illustrative interface elements shown.
[0029] The meeting management software associated interfaces 110 , 115 , 116 , 117 can include one or more computer program products through which meetings are able to be defined and managed. The meeting management software can be an integrated component of a collaboration suite or can be a stand-alone program. For example, the meeting management software can include, but is not limited to LOTUS SAMETIME, I-CALENDAR, SHAREPOINT, OFFICE LIVE, OUTLOOK, MS PROJECT, and the like. The meeting management software can also be communicatively linked to one or more communication servers, which include email servers, instance messaging servers, fax servers, automated dialing servers, and the like.
[0030] Also, different computing devices 104 can be used by different individuals 102 , 108 to access this calendaring system at different times. Thus, the different invitees 108 can use different client-side applications (having application specific interfaces 115 and 116 ) to maintain their own electronic calendars. Any of a variety of computing arrangements can be utilized to implement the scenarios 120 , 140 , 160 , all of which are to be considered within a scope of the present document.
[0031] The computing device(s) 104 and server 106 can be any computing device capable of rendering and serving content of user interfaces 110 , 115 , 116 , 117 and of performing the processing for meeting events described herein. Clients 104 can include, for example, a personal computer, a notebook computer, a thin client, a kiosk, an embedded computing device, a smart phone, a personal data assistant, a wearable computer, an electronic gaming device, an internet appliance, a media player, a navigation device, and the like. Server(s) 106 can include a set of one or more servers, virtual or physical, capable of facilitating meetings and exchanging communications among initiator 102 and invitee(s) 108 . In one embodiment, the server(s) 106 can be implemented in a cluster or another redundant fashion, which enhances a scalability and a resiliency of the solution presented in FIG. 1 .
[0032] As used herein, the meeting initiation time 122 , the prompting time 142 , and the tally time 162 each represent a time span for a set of activities to occur. These times 122 , 142 , 162 are to be construed liberally to include standard processing and interactive times, which can include delays for data store batch processing, synchronization, confirmation, and the like. Thus, each of these times can represent a time span from minutes to hours or days, depending upon implementation specifics.
[0033] A meeting is defined within as an occurrence or event involving a set of one or more users 102 , 108 . A meeting can also have an associated location, time, and purpose. The meeting can include a physical gathering which one or more person is able to attend, a virtual meeting space, and combinations of the two. Meetings can include one-time occasions as well as repeating occurrences based upon a definable interval.
[0034] Network 103 , which connects the devices 104 , server 106 , and data store 109 to each other, can include any hardware/software/and firmware necessary to convey digital content encoded within carrier waves. Content can be contained within analog or digital signals and conveyed through data or voice channels and can be conveyed over a personal area network (PAN) or a wide area network (WAN). The network 103 can include local components and data pathways necessary for communications to be exchanged among computing device components and between integrated device components and peripheral devices. The network 103 can also include network equipment, such as routers, data lines, hubs, and intermediary servers which together form a packet-based network, such as the Internet or an intranet. The network 103 can further include circuit-based communication components and mobile communication components, such as telephony switches, modems, cellular communication towers, and the like. The network 103 can include line based and/or wireless communication pathways.
[0035] The information managed by server 106 and device(s) 014 can be stored in a one or more data stores, which includes data store 109 . These data stores can be a physical or virtual storage spaces configured to store digital information. The data stores can be physically implemented within any type of hardware including, but not limited to, a magnetic disk, an optical disk, a semiconductor memory, a digitally encoded plastic memory, a holographic memory, or any other recording medium. Each of data stores can be a stand-alone storage unit as well as a storage unit formed from one or more physical devices. Additionally, information can be stored within the data stores in a variety of manners. For example, information can be stored within a database structure or can be stored within one or more files of a file storage system, where each file may or may not be indexed for information searching purposes. Further, the data stores can optionally utilize one or more encryption mechanisms to protect stored information from unauthorized access.
[0036] The diagrams in FIG. 1 illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
[0037] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
[0038] The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated. | A meeting initialization request for a meeting can be identified. The meeting initialization request can specify a prompt time for attendance intentions. A programmatic trigger, referred to as a prompt trigger, can be established for the prompt time. A firing of this prompt trigger can occur when a current time equals the prompt time. At this time, at least one potential attendee for the meeting can be determined. A set of potential attendees is typically defined by the meeting initiator within the meeting initialization request. An intention message can be sent to the determined potential attendee responsive to a firing of the programmatic trigger. This intention message can be sent at a time close to the prompt time. The intention message can prompt the potential attendee to indicate whether the potential attendee intends to attend the meeting. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to a tire manufacturing method and a machine, and particularly to method and a machine for forming a green-case by a first forming machine.
In the first forming machine, beads are driven on portions near both ends of a ply applied on a drum and the both ends are folded back about the beads by means of bladders to form a green-case. The bead setter is required to be driven with a thrust higher than 4 tons to drive the beads and fold back the ply, and therefore in conventional bead setters, hydraulic cylinders have been used.
For example, a hydraulic pump is operated by a large capacity electric motor of 15 Kw or more and the hydraulic cylinder is driven by oil pressure caused by the hydraulic pump to move a bead holder.
The oil pressure of the hydraulic cylinder can be changed barely in two steps of high and low, and it is impossible to set thrust and moving speed separately. Therefore moving speed is sacrificed to obtain a necessary thrust and the production efficiency is low. Since thrust can not be adjusted step by step, it is impossible to correspond with various tire sizes.
In the case where the hydraulic cylinder is operated with high oil pressure, the thrust is too large for some tire sizes and the beads are apt to slip off when the beads are driven or the ply is folded back, therefore there is a problem that quality of the tire deteriorates owing to the slipping off of the beads.
On the other hand, in the case that the hydraulic cylinder is operated with low oil pressure, there is a fear that the thrust for driving the beads or folding back the ply is insufficient and it is impossible to cope with various tire sizes.
Since the hydraulic pump is driven by the electric motor of large capacity, electric power consumption is large. It is necessary to inspect the hydraulic pump periodically to confirm the oil amount, therefore many man-hours are required for maintenance and the work is troublesome. The mechanism becomes complicated because a hydraulic circuit must be constituted, and sometimes an additional cooling fan is required to avoid increase of oil temperature resulting in high cost.
SUMMARY OF THE INVENTION
The present invention has been accomplished in view of the foregoing and one object of the invention is to provide a tire manufacturing method enabling a tire to maintain high quality. Another object of the invention is to provide a tire manufacturing machine of a simple construction and low cost to improving productivity, saving energy and reducing maintenance man-hours.
In order to attain the above one object, the present invention provides a tire manufacturing method for manufacturing on a drum a tire green-case, comprising the steps of: winding a ply round the drum; expanding the drum to enlarge its diameter; positioning annular beads held by an inner bead holder and an outer bead holder at respective predetermined positions on both sides of the drum; advancing each of the inner and outer bead holders toward the drum with thrust controlled by a control means to drive the beads; retreating the inner and outer bead holders; expanding bladders positioned on both sides of the ply; advancing again each of the inner and outer bead holders toward the drum with thrust controlled by the control means to press the expanded bladder laterally, thereby both sides of the ply being folded back so as to wrap the beads; and pressing the both sides of the ply folded back against a main part of the ply.
Since the thrust of the bead holder is controlled by the control means when the bead holder drives the bead, the bead does not slip off at that time. Further, since the control means carries out folding back of the ply controlling the thrust of the bead holder, there is no fear that the driven bead slips off when the ply is folded back. As the result, quality of the produced tire as well as the green-case is improved.
In order to attain the above another object, the present invention provides a tire manufacturing machine for forming a green-case by driving beads on portions near both ends of a ply applied on a drum and folding back both ends about the beads by means of bladders, comprising bead holders movable in the axial direction provided on both sides of the drum for holding the beads to drive them on the portions near both ends of the ply and pressing down the expanded bladders to assist in folding back the both ends of the ply, an electric motor as a power source, control means for controlling the drive of the electric motor, and a driving mechanism through which the electric motor moves the bead holder.
Since the electric motor controlled by the control means drives the bead holder through the driving mechanism, thrust control and moving speed control can be carried out separately. Therefore a pertinent thrust in accordance with a tire size can be obtained when the bead is driven or the ply is folded back to prevent slip off of the bead, and it is possible to shorten working hours and improve production efficiency by increasing the moving speed when the bead holder is merely moved.
Since the mechanism is driven by the electric motor, the construction is simple, maintenance man-hours, i.e., is few, operation is easy and cost can be reduced.
According to an aspect of the present invention, in the above tire manufacturing machine, position detection means for detecting a position of the bead holder is provided, and the control means controls speed and torque of the electric motor on the basis of the position of the bead holder detected by the position detection means.
When the bead holder is in a position for driving the bead or in a position for folding back the ply, the driving and folding back can be carried out with a pertinent thrust by the torque control, and when the bead holder is in a position for moving, the bead holder is moved at a high speed by the moving speed control to shorten working hour and raise production efficiency.
The above-mentioned electric motor may be a servomotor or an induction motor subjected to vector control. Step by step thrust adjustments or fine controls can be carried out in accordance with tire sizes.
The above-mentioned driving mechanism may be a ball screw mechanism connected to the electric motor or an electric cylinder with the electric motor built in. Owing to the ball screw mechanism or a variable speed mechanism of the motor for the electric cylinder, capacity of the motor can be reduced, electric power consumption is small and energy consumption can be suppressed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partly omitted side view of a tire forming machine according to a preferred embodiment of the present invention;
FIG. 2 is an enlarged side view of a bead holder;
FIG. 3 is a rough block diagram of a drive control system of the bead setter;
FIG. 4 is a sectional view of an essential part for showing one step of a green tire forming;
FIG. 5 is a sectional view of the essential part at bead driving;
FIG. 6 is a sectional view of the essential part at bladder expanding;
FIG. 7 is a sectional view of the essential part at ply folding back;
FIG. 8 is a control timing chart in the bead driving step; and
FIG. 9 is a control timing chart in the ply folding back step.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Hereinafter, a preferred embodiment of the present invention will be described with reference to FIGS. 1 to 9.
FIG. 1 is a partly omitted side view of a tire forming machine for the first formation. A driving apparatus 2 is erected on the left side, a rotary shaft 3 is projected to the right horizontally from the driving apparatus 1 and a drum 4 is supported at an end of the rotary shaft 3.
The diameter of the drum 4 can be increased and decreased. On the both sides of the drum 4, bladders 5, 6 are extended in shape of cylindrical bags. When the diameter of the drum 4 is increased, it is larger than the outer diameters of the bladders 5, 6 so that annular steps 5a, 6a are formed between the drum 4 and the bladders 5, 6.
Between the drum 4 and the driving apparatus 2 is disposed an inner bead setter 11 movably right and left. The inner bead setter 11 is erected on a slide carriage 14 and has an annular supporting member 13 for supporting a bead holder 12. The rotary shaft 3 passes through the interior of the annular supporting member 13 along the center line thereof. The slide carriage 14 is supported on a rail 16 laid in right and left direction through sliders 15.
On the side of the driving apparatus 2, a servomotor 18 and a bearing member 21 are supported by a bracket 17, and a ball screw 23 ia supported rotationally by the bearing member 21. A gear 20 fitted to the left end of the ball screw 23 is engaged with a gear 19 fitted to a drive shaft of the servomotor 18. The ball screw 23 extends toward the right and passes through and engages with a nut 24 fixed to the left end part of the slide carriage 14 to form a ball screw mechanism 22.
Therefore, when the ball screw 23 is driven through the gears 19, 20 by the servomotor 18 to rotate, the nut 24 engaged with the ball screw 23 moves right and left together with the slide carriage 14. Namely, the bead holder 12 supported by the annular supporting member 13 of the inner bead setter 11 erected on the slide carriage 14 is moved right and left by the servomotor 18 through the ball screw mechanism 22 to approach and leave the drum.
A plurality of the bead holders 12 are arranged circumferentially on the right side surface of the annular supporting member 13. The bead holders 12 are always on a concentric circle and capable of moving radially all at once to enlarge or reduce the diameter of the concentric circle. As shown in FIG. 2, each bead holder 12 has a side wall 12a, an inclined wall 12b extending obliquely to the right from an outer edge of the side wall 12a and a projection 12c somewhat projected to the right from an inner edge of the side wall 12a.
The bead holders 12 support an annular bead B which is positioned between the inclined walls 12b and the projections 12c along the side walls 12a of the bead holders 12 to be enlarged diametrically by the projections 12c (FIG. 2).
On the right of the drum 4, an outer bead setter 31 is disposed movably right and left in the same manner as the inner bead setter 11. The outer bead setter 31 has a construction symmetrical with the inner bead setter 11 and a plurality of bead holders 32 are supported movably in radial directions on an annular supporting member 33 erected on a rotary pedestal 34.
On the rotary pedestal 34, besides the annular supporting member 33, a case holding apparatus 35 for supporting a green-case is mounted. The rotary pedestal 34 is supported on a slide carriage 36 rotationally about a vertical axis so that positions of the outer bead setter 31 and the case holding apparatus 35 can be alternated with each other by rotating the rotary pedestal 34 by 180 degrees.
The slide carriage 36 is movably supported through sliders 37 on a rail 38 laid in the right and left direction.
On the side of the driving apparatus 2 are supported a servomotor 40 and a bearing member 43 supporting a ball screw 43 rotationally, and a gear 42 fitted to a left end of the ball screw 45 is engaged with a gear 41 fitted to a driving shaft of the servomotor 40. The ball screw 45 extends to the right and passes through and engages a nut fixed to a left end part of the slide carriage 36 to form a ball screw mechanism 44.
Therefore, when the ball screw 45 is driven by the servomotor 40 through the gears 41, 42 to rotate, the nut engaged with the ball screw 45 moves right and left together with the slide carriage 36. Namely, the bead holder 32 supported by the annular supporting member 33 of the outer bead setter 31 erected on the rotary pedestal 34 on the slide carriage 36 is moved right and left by the servomotor 40 through the ball screw mechanism 44 to approach and leave the drum 4.
Thus, the inner bead setter 11 and the outer bead setter 31 can be moved right and left by the servomotors 18, 40 through the ball screw mechanisms 22, 44.
The servomotors 18, 40 having capacities of 2.2 Kw and 3.7 Kw respectively are controlled by a computer 50 as shown in FIG. 3 which is a rough block diagram of the control system.
The servomotors 18, 40 are controlled through motor controller amplifiers 51, 52 in accordance with control instructions from the computer 50.
Numbers of revolutions of the servomotors 18, 40 are detected by encoders 53, 54. Since the detected numbers of revolutions correspond to positions of the inner and outer bead setters 11, 31 moved right and left, the encoders 53, 54 detect the positions of the bead setters 11, 31. The detection signals are fed back to the motor controller amplifiers 51, 52.
The computer 50 is stored with optimum control values of control timing, moving speed (rotational speed) and thrust (rotational torque) for every tire size, and outputs control instruction signals based on the control values to the motor controller amplifiers 51, 52.
The motor controller amplifiers 51, 52 control the servomotors 18, 40 in accordance with the control instructions from the computer 50 and the position detection signals from the encoders 53, 54 with a matched timing. By using the motor controller amplifiers 51, 52, rotational speed and torque can be changed arbitrarily in performance of the servomotors 18, 40.
Green tire forming steps by the above-mentioned tire forming machine 1 are shown in FIGS. 4 to 7 in order and timing charts of the speed control are shown in FIGS. 8 and 9.
At first, as shown in FIG. 4, a ply P is wound round the drum 4, the diameter of the drum is expanded and the inner and outer bead setters 11, 12 having bead holders 12, 32 holding respective annular beads B are positioned at predetermined positions on the both sides.
As the result of the expansion of the drum 4, steps 5a, 6a (FIG. 1) are formed between the drum 4 and the bladders 5, 6 and at the same time similar annular steps Pa, Pa are formed on the wound ply P.
Then the servomotors 18, 40 are operated and the inner and outer bead setters 11, 31 approach the drum 4 to drive the beads.
FIG. 8 is a timing chart of speed control regarding the inner bead setter 11. With regard to the outer bead setter 31 also nearly the same control is carried out.
Immediately after expansion of the drum 4, the servomotors 18, 40 are operated in a speed control mode to move the inner and outer bead setters 11, 31 at a high speed to positions predetermined for every tire sizes (duration T1 of FIG. 8). As shown in FIG. 5, the beads B, B held by the bead holders 12, 32 are driven against the annular steps Pa, Pa formed at the right and left sides of the ply P wound round the drum 4.
Immediately before the beads B, B are driven against the steps Pa, Pa of the ply P, the servomotors 18, 40 are changed over into a torque control mode to press the beads B, B against the steps Pa, Pa of the ply P during a predetermined time (duration T2 of FIG. 8) for bead driving.
Next, the servomotors 18, 40 are changed over into the speed control mode to let the bead holders 12, 32 go back a little at a high speed leaving the beads B, B at the steps Pa, Pa (duration T3 of FIG. 8).
Immediately before the bead holders 12, 32 go back, the bead holders 12, 32 move radially inward a little to reduce the diameter of the concentric circle for releasing the beads B, B.
After the beads B, B are driven in such a manner, a ply folding back step is started and the bladders 5, 6 are expanded. FIG. 6 is a view showing the expanded bladders in which the right and left sides of the ply P are going to be folded back about the beads B, B.
Next, the servomotors 18, 40 are operated in the speed control mode to move the bead holders 12, 32 somewhat expanded at a high speed to positions predetermined for every tire sizes (duration T1 of FIG. 9).
The bead holders 12, 32 press the expanded bladders 5, 6 sideways to lay down the outer periphery of the bladders 5, 6 onto the peripheral surface of the drum 4 so that the right and left sides of the ply P are folded back so as to wrap the beads B.
Immediately before the bead holders 12, 32 reach positions for folding back the ply, the servomotors 18, 40 are changed over into the torque control mode to press the bladders 5, 6 with a thrust predetermined for every tire size.
Therefore, there is no fear that the bead driven already slips off when the ply is folded back. As the result, quality of the green-case after folding back the ply can be maintained high so that quality of the manufactured tire can be improved.
Since the bead holders 12, 32 press the bladders 5, 6 with the predetermined thrust during a predetermined time (duration T2 of FIG. 9), the right and left sides of the ply P folded back are fixedly pressed on the main part of the ply P by the deformed bladders 5, 6.
Then the servomotors are changed over into the speed control mode and the bead holders 12, 32 go back to the original predetermined positions at a high speed (duration T3 of FIG. 9). Thus a green-case is formed and after that the rotary pedestal 34 turns to direct the case holding apparatus 35 toward the drum 4. The green-case is taken up by the case holding apparatus 35 and transported to a next applying stage.
As mentioned above, when the bead holders 12, 32 are positioned at the bead driving positions and the ply folding back positions, the servomotors 18, 40 are controlled in the torque control mode to press the beads with a predetermined thrust matched with the tire size.
And when the bead holders 12, 32 are positioned at other moving positions, the servomotors 18, 40 are controlled in the speed control mode to move the bead holders at the high sped to shorten the working time and raise the production efficiency.
Since the servomotors 18, 40 are controlled through the controller amplifiers 51, 52, rotational speed and torque can be changed within the performance of the motor and the inner and outer bead setters 11, 12 can be subjected to pertinent position control, speed control and thrust control in accordance with tire sizes.
Owing to the ball screw mechanisms 22, 44 and variable speed mechanisms of the motors, the servomotors 18, 40 have small capacities of 2.2 Kw and 3.7 Kw and electric power consumption is low for enabling to suppress energy consumption.
Since the inner and outer bead setters 11, 31 are driven by means of simple structures which are combinations of the servomotors 18, 40 and ball screw mechanisms 22, 44, the cost is low, the maintenance man-hour is few and the working is easy.
Besides the servomotor, an induction motor subjected to vector control or an electric cylinder with a motor built in may be used. | A tire manufacturing method enabling a tire to maintain a high quality and a tire manufacturing machine of a simple construction and low cost by which improvement of productivity, saving of energy and reduction of maintenance man-hour are possible is provided. A tire green-case is manufactured on a drum by the steps of winding a ply round the drum; expanding the drum to enlarge its diameter; positioning annular beads held by an inner base holder and an outer bead holder at respective predetermined positions on both sides of the drum; advancing each of the inner and outer bead holders toward the drum with thrust controlled by a control means to drive the beads; retreating the inner and outer bead holders; expanding bladders positioned on both sides of the ply; advancing again each of the inner and outer bead holders toward the drum with thrust controlled by the control means to press the expanded bladder laterally, thereby both sides of the ply being folded back so as to wrap the beads; and pressing the both sides of the ply folded back against a main part of the ply. | 1 |
This application is a continuation of co-pending U.S. patent application Ser. No. 09/800,253 filed Mar. 6, 2001.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to game controllers, and more particularly, to a genre specific game controller for driving or steering applications.
2. Description of the Prior Art
The concept of a genre specific game controller is well known in the gaming industry. Examples of such genre specific games that utilize genre specific game controllers are flight simulators, first person shooting games, and driving games.
Some examples of driving or steering assemblies for video gaming are shown in U.S. Pat. Nos. 5,829,745 and 6,083,106. The '745 patent discloses a video game control unit with self-centering steering wheel. This control unit includes a separable console and base sections, with the console section housing a steering wheel video game input device that automatically returns to a central, neutral position. This steering wheel controller is very cumbersome and is exclusively dedicated to driving games and cannot be used with other genres of games.
U.S. Pat. No. 6,083,106 discloses a video game race car simulator assembly for simulating sitting in the driver seat of a racing car when playing a driving video game. This simulator is not designed for home use, and as such prevents the implementation into home video gaming systems such as, for example, Sony PlayStation®, Sega DREAMCAST®, Nintendo 64®, etc.
U.S. Pat. No. 5,785,317 discloses an operation apparatus for a game machine. This game controller is a two-handed controller requiring the user to hold both sides simultaneously and thereby enable them to actuate controls on both sides of the housing. In addition, the housing of this game controller is designed to twist in the middle so as to provide the user with improved feeling and operation. This controller can be utilized for driving games and provide the user with the ability to “steer” by twisting the controller accordingly. This design, althoughunique has a shortfall in that the twisting action of the controller can interfere with the user's ability to actuate any of the controls mounted on the top of the controller. As such, there is too much movement in the controller to provide the user with accurate control over the game being played.
U.S. Pat. No. 5,923,317 discloses a two-handed controller for video games and simulations. This game controller shows the use of buttons disposed on the underside of the game controller to simulate trigger action for the user. These trigger buttons are not part of the D-pad or other movement controls associated with the controller.
To date, all video game controllers for the home gaming environment utilize movement controls and trigger controls (i-e., buttons that control a game action such as, for example, firing one or more weapons and braking or acceleration of a motor vehicle). The movement controls are generally in the form of a joystick or D-pad. The joystick or D-pad provides the user with two-dimensional movement control in a fixed plane. Although most controllers are designed for two-handed actuation, the movement controller (i.e., joystick or D-pad) is one part of the controller that is generally actuated with one of the user's hands (or fingers). As such, in certain genre specific gaming environments, the standard two-dimensional movement control provided by a D-pad or joystick is less than desirable and makes playing the game more difficult for the user.
Examples of such genre specific games are driving games where the user is required to steer a motor vehicle. These games generally require a higher degree of precision and variability in the game controls in order to properly effect steering during play. In addition, in order to provide a more realistic driving/steering experience, the user should be required to utilize both hands for steering. The standard D-pad or joystick fails to meet this preferred criteria. Other steering wheel controllers in the shape of a steering wheel promote the two-handed driving/steering experience, however fail to generally provide the other ergonomically preferred designs of two-handed controllers (e.g., U.S. Pat. Nos. 6,102,803 and 5,785,317)., including the disposition of other controls used in conjunction with the genre specific control.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a game controller that includes additional driving/steering game controls for operation by the user without interfering with the other existing buttons or controls on a two-handed game controller.
It is another object of the invention to provide a game controller that may be selectively used with genre specific driving games, while remaining capable of performing all standard basic two-handed gaming functions.
Yet another object of the invention is to provide a game controller having dedicated driving/steering levers disposed on the underside of the controller that provide more accurate and reliable steering control to the user.
These and other objects are achieved in accordance with an embodiment of the invention, wherein a genre specific game controller for driving and steering applications includes a game controller housing adapted for two-hand operation, a plurality of game controls disposed on an upper side of said housing, and a steering lever disposed on an underside of said housing and having two lever ends each adapted to be actuated by fingers on one of the user's hands.
According to one embodiment, the steering lever is a single piece lever having a rotation axle rotatably connected to the game controller through said housing. The lever ends extend from the rotation axle and when one end is rotated about the rotation axle, the other end moves in an opposite direction. Electronic circuitry disposed within the game controller housing detects the position of the steering lever and outputs variable electrical control commands corresponding to the detected variable positions of the lever ends.
According to another embodiment, the steering lever is a two piece lever having a central axle. Each piece of the two piece lever is rotatably connected to the game controller about the central axle and through the housing. Each of the lever ends are formed by one of the two piece lever and each are independently operable with respect to the other. Electronic circuitry disposed within the game controller housing detects the independent position of each of the steering lever ends and outputs variable electrical control commands corresponding to the detected variable positions of the lever ends.
Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings wherein like reference numeral denote similar components throughout the views:
FIG. 1 a is a front view of a game controller according to a first embodiment of the invention;
FIG. 1 b is a side view of the game controller according to the first embodiment of the invention;
FIG. 1 c is a bottom view of the game controller according to the first embodiment of the invention;
FIG. 2 a is a front view of a game controller according to a second embodiment of the invention;
FIG. 2 b is a bottom view of the game controller according to the second embodiment of the invention,
FIG. 3 a a front view of a game controller according to a third embodiment of the invention;
FIG. 3 b is a side view of the game controller according to the third embodiment of the invention;
FIG. 3 c is a bottom view of the game controller according to the third embodiment of the invention;
FIG. 4 a is a front view of a game controller according to a fourth embodiment of the invention;
FIG. 4 b is a bottom view of the game controller according the fourth embodiment of the invention;
FIG. 5 a is a partial cross section showing the internal operation of the game controller according to the first embodiment of the invention;
FIG. 5 b is a partial cross section showing the internal operation of game controller according to the second embodiment of the invention;
FIG. 6 a is a partial cross section showing the internal operation of the game controller according to the first embodiment of the invention;
FIG. 6 b is a partial cross section showing the internal operation of the game controller according to the first embodiment of the invention;
FIG. 7 is a partial cross section showing the internal operation of the game controller according to the third embodiment of the invention;
FIG. 8 a is a partial cross section showing another embodiment of the internal operation of the game controller according to the first embodiment of the invention;
FIG. 8 b is partial cross section of the lever arrangement of the embodiment of FIG. 8 a;
FIG. 9 a is a partial cross section showing another embodiment of the internal operation of game controller according to the second embodiment of the invention;
FIG. 9 b is a partial cross section of the lever arrangement of the embodiment of FIG. 9 a;
FIG. 10 a is a partial cross section showing another embodiment of the internal operation of the game controller according to the fourth embodiment of the invention;
FIG. 10 b is an exemplary implementation of the sensor arrangement for the embodiment depicted in FIG. 10 a,
FIG. 10 c is another exemplary implementation of the sensor arrangement for the embodiment depicted in FIG. 10 a;
FIG. 11 a is a block representation of the sensor configuration according to the embodiment invention;
FIG. 11 b is a block representation of the sensor configuration according to another embodiment of the invention; and
FIG. 11 c is a block representation of the sensor configuration according to another embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1 a - 1 c , there is shown a game controller 10 according to a first embodiment of the invention. Game controller 10 includes a housing 12 , a plurality of upper game controls 14 and a plurality of front control buttons 16 a - 16 d . A central axis 18 runs through game controller housing 12 transverse to the two-dimensional plane in which the D-pad or joystick operates. The aforementioned D-pad and/or joystick are included in the plurality of upper game controls 14 .
In accordance with the present embodiment, a driving/steering lever 20 is disposed on the underside of the controller housing 12 and is rotatably mounted about a rotation axle 22 which is coaxially aligned with central axis 18 . Lever 20 is spring biased into a center position and includes two lever ends 24 a and 24 b positioned to be actuated by the fingers of the user's right and left hands, respectively. Lever 20 is variably actuated based on the degree of depression applied by the user. Referring to FIG. 1 c , when lever end 24 b is actuated in the direction indicated by arrow Al, the opposing end 24 a is displaced an equal amount in the direction A 2 (as shown by dotted lines in FIG. 1 c ). The variable position ability of lever 20 in addition to its ergonomic disposition on the underside of the controller allows the user to more accurately and realistically apply steering control in response to the video game being played. The rotating action of lever 20 enables the steering/driving control to be accurately and variably controlled while allowing the user to maintain both hands on the controller at all times. This further allows the user to actuate any of the upper 14 or front 16 controls during steering/driving action.
FIG. 5 a shows one example of the electronic implementation of lever 20 into game controller 10 . As shown a potentiometer 42 is connected to a printed circuit board 40 contained within housing 12 . Rotation axle 22 of lever 20 is connected to or integral with the stem of potentiometer 42 , and a spring 44 , wound around axle 22 and held in place by notches 46 a and 46 b , biases lever 20 into its central operable position. Thus, the actuation of either lever end 24 a or 24 b changes the resistance output of potentiometer 42 and thereby allows for the variable steering/driving adjustment of a video game being played through a connected game console (not shown).
FIGS. 2 a and 2 b show a second embodiment where steering lever 20 is separated into two independently operable parts consisting of lever ends 24 a and 24 b . In this embodiment, each lever end 24 a and 24 b is independent of the other. Thus, when lever end 24 b is depressed in the direction indicated by A 1 , lever end 24 a does not move. This embodiment requires additional control circuitry as shown in FIGS. 5 b and 9 a.
Referring to FIG. 5 b , there is shown an embodiment for the independent control and actuation performed by independent levers 24 a and 24 b . As shown, separate potentiometers 42 a and 42 b are connected to circuit board 40 and to the respective lever end 24 a and 24 b via a gear mechanism made up of gears 47 a and 47 b . Those of skill in the art will recognize that the rotation axle 22 must now be configured to allow each lever end 24 a and 24 b to rotate independently of each other. Axle 22 can be configured to have an inner axle 26 connecting lever end 24 a to potentiometer 42 a via gears 47 a and 43 a . Accordingly, an outer axle 28 connects lever end 24 b to potentiometer 42 b via gears 47 b and 43 b . The spring 44 can be positioned as shown and notches 46 a and 46 b are disposed accordingly to allow each lever end 24 a and 24 b to be spring biased in a desired direction or position. Thus, when one lever end 24 a or 24 b is actuated, the corresponding potentiometer 42 a or 42 b will change its resistance output in response to that movement and thereby allow the variable, and increased accuracy of driving control in the desired direction.
The embodiment shown in FIG. 5 b is one example of how such configuration may be implemented. Those of ordinary skill will recognize that various other methods for allowing the independent rotation and actuation may be implemented without departing from the spirit of the invention.
FIGS. 6 a and 6 b show another circuitry implementation operable for the embodiment depicted in FIGS. 1 a , 1 b and 1 c . In this embodiment, a pair of hall effect sensors 48 a and 48 b are connected to the circuit board 40 , and an opposing pair of magnets 49 a and 49 b are positioned on a holder 59 mounted to the axle 22 . Thus, when either of the lever ends 24 a or 24 b are moved, the positions of the magnets 49 a and 49 b are detected by the corresponding hall effect sensors 48 a and 48 b (i.e., based on the strength of the magnetic fields created by the magnets), and the corresponding electrical steering/driving command is generated and output to the connected game console (not shown).
FIGS. 3 a - 3 c show a third embodiment where steering lever 30 is a one piece lever that pivots about a centrally disposed pivot line P, transverse to central axis 18 . Steering lever 30 is spring biased and includes lever ends 32 a and 32 b that are actuated by the user engaging and pulling the lever end in the direction indicated by arrow A 3 . When lever end 32 b is engaged as shown in
FIG. 3 a , opposing end 32 a responds by moving in an opposite direction A 4 (shown in dotted lines). The pivotal action of lever 30 enables the steering/driving control to be accurately and variably controlled while allowing the user to maintain both hands on the controller at all times. This further allows the user to actuate any of the upper 14 or front 16 controls during driving action. FIGS. 4 a and 4 b show a modified embodiment where lever 30 is separated into two independently operable ends 32 a and 32 b , each being pivotal about pivot line P.
FIG. 7 shows the electrical implementation of the embodiments disclosed in FIGS. 3 a - 4 b . As shown, the lever arm 30 is connected to a pivot mount 50 by two legs 34 a and 34 b . The pivot mount 50 includes a pivot ball 52 pivoting upon a pivot indentation 53 within the controller housing, and magnets 49 a and 49 b arranged thereon. The pivot mount 50 , and thereby lever arm 30 , is biased into a center position by springs 36 a and 36 b . Corresponding hall effect sensors 48 a and 48 b are mounted on the circuit board 40 and are positioned so as to detect the movement of the respective magnets 49 a and 49 b and produce electrical control signals accordingly. In the independent arm operation embodiment of FIGS. 4 a and 4 b , the pivot mount 50 need not be separated into two parts, but rather the lever arm 30 separated into it's two lever ends 32 a and 32 b while retaining a flexible connection to prevent separation from each other. In this arrangement, the hall effect sensors 48 a and 48 b and magnets 49 a and 49 b will continue to operate as desired.
FIGS. 8 a and 8 b show another embodiment of the electronic implementation of lever 20 (made up of lever ends 24 a and 24 b ) into the game controller. As shown, lever ends 24 a and 24 b have interlocking teeth 64 a and 64 b , respectively, arranged around the rotation axle 22 . A cap or other securing mechanism 66 attached onto axle 22 and retains lever ends 24 a and 24 b in their operable position on the underside of the game controller. An arm or extension 60 is connected to rotation axle 22 and includes a sensor mechanism 62 for sensing the rotation motion of the lever ends 24 a and 24 b and providing output signals corresponding to the detected lever end movement. Sensor mechanism 62 is described later with reference to FIGS. 11 a - 11 c
FIGS. 9 a and 9 b show another embodiment of the electronic implementation of lever 20 (made up of lever ends 24 a and 24 b ) into the game controller. This embodiment is particularly suited for the independent operation of lever ends 24 a and 24 b , as discussed above with respect to the embodiments of FIGS. 2 a and 2 b . As shown, each lever end 24 a and 24 b includes a corresponding rotation shaft 23 a and 23 b having an arm or extension 61 a and 61 b , respectively. Extensions 61 a and 61 b carry part of the sensor mechanism 62 used to detect the rotation position of each lever arm 24 a and 24 b , respectively. As with the embodiment of FIGS. 8 a and 8 b , a cap or other device 66 secures the levers 24 a and 24 b in their operable positions and onto rotation axles 23 a and 23 b , respectively.
FIGS. 10 a - 10 c show an alternative embodiment for implementing the pivoting steering lever 30 (made up of lever ends 32 a and 32 b ) into the game controller. Accordingly, each lever end 34 a and 34 b is pivotally connected to the circuit board 40 or controller housing 12 via pivot shafts 70 a and 70 b , respectively. A hall effect sensor 48 a and 48 b is mounted on the circuit board 40 , with correspondingly mounted magnets 49 a and 49 b on the respective levers 32 a and 32 b (FIGS. 10 a and 10 b ). FIG. 10 c shows an alternative embodiment where a pressure sensor 58 is connected to the circuit board 40 and operable to detect the pressure applied to the levers and output corresponding control signals from the game controller.
FIGS. 11 a - 11 c show various exemplary embodiments for the implementation of sensor mechanism 62 . FIG. 11 a shows the use of a hall effect sensor 48 mounted to the circuit board 40 and a correspondingly arranged magnet 49 carried by rotating extension 60 . FIG. 11 b shows the use of a light sensor 72 with light source 74 mounted on circuit board 40 . A slotted wheel 76 passes between the sensor 72 and light source 74 so as to provide the rotation detection capability required for the levers. FIG. 11 c shows another embodiment where a piezo sensor is mounted on the extension 60 and in electrical contact with the circuit board 40 .
Those of ordinary skill in the art will recognize that the implementation embodiments shown in FIGS. 5 a - 11 c are examples of such implementation and may be modified without departing from the spirit of the invention
While there have shown and described and pointed out fundamental novel features of the invention as applied to preferred embodiments thereof, it will be understood that various omissions and substitutions and changes in the form and details of the methods described and devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto. | A steering/driving game controller integrates an additional steering lever to the underside of the game controller. The steering lever is spring biased in a center operable positions and is variably actuated such that it is responsive to varying degrees of depression. In response to the varying degree of user depression, the steering/driving controller is capable of outputting steering control signals of varying level to a connected game console, thereby enabling more selective and more accurate driving control within a video game being played on the connected game console. | 0 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to flooring panels for use in commercial, industrial or residential environments. More particularly, this invention relates to flooring panels having an aesthetically pleasing appearance provided by texturing imparted to the surface of the panels. In certain embodiments, the texture is aligned in registration with a visible graphic design displayed by the panel to further enhance the aesthetic appearance of the flooring panel.
[0003] 2. Background Art
[0004] Various laminates, including high pressure laminates and fiberboard core laminates, are commonly used in flooring applications. Fiberboard core laminates used to manufacture flooring products include a plurality of layers, including a fiberboard or organic composite core section, a decorative layer, and a hard and flat protective wear layer of resin-impregnated melamine material.
[0005] The wear layer of the laminate in such systems is typically clear, such that the aesthetic appearance, including any color and/or printed image of the decorative layer, is not obscured by the wear layer. Further, the top surface of the wear layer is typically flat, such that the flooring panel exhibits a two-dimensional appearance to the onlooker. Thus, while the decorative layer may exhibit an appearance that simulates “natural” flooring materials such as hardwood or ceramic tile, the typical laminate wear layer simply allows an unobstructed view of the laminate decorative layer, and does not add to or enhance the aesthetic properties of the flooring panel.
[0006] Some prior art laminate flooring systems have included barely-perceptible indentations imparted to the laminate wear layer to interrupt the aforementioned two-dimensional appearance. Those systems feature shallow indentations of a depth not exceeding 0.25 millimeters (“mm”). Further, the location of individual indentations or the “pattern” of indentations provided in prior art systems are unrelated and unlinked to the aesthetic image provided by the decorative laminate layer. Thus, any indentation pattern in prior art laminate wear layers is not related in any way to the selected aesthetic appearance of the decorative laminate layer.
SUMMARY OF THE INVENTION
[0007] The present invention, in one embodiment, is a decorated floor panel including a core having a top surface and an opposite bottom surface. A decorative layer is adhered to the top surface of the core and, in one embodiment, substantially covers the core. A desired aesthetic appearance, such as a hardwood or ceramic tile appearance, is displayed by the decorative layer of the laminate. Finally, a wear layer is provided over the decorative layer, substantially covering the decorative layer and providing protection from the ambient environment. The wear layer has an exposed wear surface with depressions therein of a variable depth below the wear surface, the depressions being arranged to display a desired texture pattern.
[0008] In another aspect, the present invention is a decorated floor panel as set forth above, wherein the depressions in the wear surface have a depth of at least 0.50 mm below the nominal surface of the wear layer. In this embodiment, the depressions may all be of a constant depth or, alternatively, of a variable depth as exists for the embodiment discussed above.
[0009] In yet another aspect, the present invention is a decorated floor panel in which the decorative layer is provided with a decorative pattern. In one embodiment, a plurality of depressions imparted to the wear layer form a desired texture pattern thereon. The relative orientation of the texture pattern and the decorative pattern is controlled such that the depression pattern and the texture pattern are substantially in registration, creating an enhanced, three-dimensional aesthetic appearance to the decorated floor panel.
[0010] In yet another aspect, the present invention is a floor system comprised of a plurality of individual decorated floor panels assembled together and interlocking with each other by tongue and groove engagement, which is not visible after the floor panels are assembled.
BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS
[0011] [0011]FIG. 1 is a perspective view of an embodiment of the decorated floor panel according to the present invention.
[0012] [0012]FIG. 1A is an enlarged fragmentary view of an embodiment of the decorated floor panel of FIG. 1, the texture pattern being represented out of registration with the decorative pattern.
[0013] [0013]FIG. 1B is an enlarged fragmentary view of an embodiment of the decorated floor panel of FIG. 1, the texture pattern being represented in registration with the decorative pattern.
[0014] [0014]FIG. 2 is a section taken along lines 2 - 2 in FIG. 1.
[0015] [0015]FIG. 3 is a perspective cut-away view of an embodiment of the decorated floor panel according to the present invention.
[0016] [0016]FIG. 4 is a perspective view of a group of decorated floor panels according to the present invention assembled to form a portion of a floor system.
[0017] [0017]FIG. 5 is a section taken along lines 5 - 5 in FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The present invention is more particularly described in the following examples that are intended as illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. As used in the specification and in the claims, “a,” “an,” or “the” can mean one or more, depending upon the context in which it is used. The preferred embodiment is now described with reference to the figures, in which like numbers indicate like parts throughout the figures.
[0019] Referring to FIG. 1, the present invention, in one embodiment, is a decorated floor panel 10 . In the illustrated embodiment, the panel 10 is manufactured from a laminated material having a fiberboard core. Alternatively, the floor panel 10 of the invention may be manufactured from other materials, including other laminates such as high pressure laminate (“HPL”), which have been marketed under such trade names as Formica and Pergo. Other materials may also be utilized to construct the floor panel, such as other natural, recycled or synthetic materials.
[0020] The fiberboard core laminate illustrated in FIG. 3 includes a plurality of discrete layers, including a wear layer 12 , a decorative layer 14 , a core 16 and a backing layer 24 . The illustrated core 16 is preferably manufactured of fiberboard, such as that marketed by companies including Louisiana Pacific, Georgia Pacific, Temple Inland and Weyerhauser. The presently preferred fiberboard core material is formed of high density fiberboard, which is a hardwood/softwood fiber compound compressed at 900-960 kg/m 3 . The preferred fiberboard core material is usually available in 4 or 5 feet widths and lengths of up to 18 feet. In other embodiments, cores 16 of different materials or having different properties may be utilized, including other timber-based products, such as plywood, chipboard or particleboard.
[0021] Referring now to FIGS. 2 and 3, the core 16 has a top surface 18 and an opposite bottom surface 20 . When installed, the bottom surface 20 of the core 16 faces the underlying subfloor (not shown). FIG. 3 illustrates an embodiment having an optional backing layer 24 adhered to the bottom surface 20 of the core 16 . Because the illustrated fiberboard core is not completely impervious to moisture and contaminants, such a backing layer 24 may be provided to improve moisture resistance of the floor panel 10 . Additionally, the backing layer 24 may improve structural integrity of the floor panel 10 by increasing overall thickness and reducing the warp and wear tendencies of uncoated core material. In one embodiment, a clear backing layer 24 of melamine, reinforced with aluminum oxide (AlO 2 ) and impregnated with a thermosetting resin, is utilized. In such an embodiment, an optional layer (not shown) may be interposed between the bottom surface 20 of the core 16 and the backing layer 24 . In one embodiment, the optional layer is constructed of paper. The optional layer may display a printed image, such as a trademark, product number or name, or any other desired marking or designation. In other embodiments, backing layers 24 may be constructed of other materials providing suitable moisture resistance, such as phenolic resins or other natural, synthetic or recycled materials.
[0022] A decorative layer or “decor” layer 14 is adhered, joined, or coupled to the top surface 18 of the core 16 by a chemical adhesive, mechanical connection, or other means known in the art. In the illustrated embodiment, the decorative layer 14 is a sheet of paper that substantially covers the top surface 18 of the core 16 . Thus, in the illustrated embodiment, the top and bottom surfaces 18 , 20 of the core 16 are covered by the decorative layer 14 and the backing layer 24 , respectively. The visible side of the decorative layer 14 , i.e., the side not adhered to the core 16 , is capable of displaying a desired aesthetic appearance, such as a color or pattern. Virtually any color or pattern may be imparted to the decorative layer 14 . For example, currently contemplated patterns include simulated hardwood flooring and simulated ceramic tile, each in a variety of styles, shades and colors. Currently contemplated simulated hardwood styles include pine, heart pine, cherry, maple, beech, oak and mahogany. Simulated tile appearances are contemplated in a range of styles, including a variety of marble and ceramic tile colors, including groutlines in ceramic tile styles. Other currently contemplated patterns include floral patterns, abstract designs, geometric designs and company logos. Other patterns may be selected by the manufacturer or user according to aesthetic preference or design objectives.
[0023] As mentioned above, in one embodiment the decorative layer 14 is manufactured from paper that may be impregnated with a thermosetting resin and provided with the desired aesthetic color and/or pattern. In other embodiments that are not shown, other materials may make up the decorative layer 14 , such as real wood veneer, pulverized stone, or other materials. Additionally, it is possible to achieve a similar decorative appearance by either a direct or indirect printing process directly onto the top surface 18 of the core 16 . In such an embodiment, the decorative layer 14 comprises whatever ink, dye, pigment or other marking substance applied to the core 16 . Alternatively, the decorative appearance may be provided by etching, burning or otherwise marring the top surface 18 of the core 16 . Any such treatment that supplies such a decorative appearance on the top surface 18 of the core 16 is contemplated to comprise the decorative layer 14 as defined herein.
[0024] Referring now to FIG. 3, a wear layer 12 is provided over the decorative layer 14 , substantially covering the decorative layer 14 and providing protection from the ambient environment. The wear layer 12 is adhered, joined, or coupled to the decorative layer 14 , just as the decorative layer 14 is joined to the underlying core 16 . In one embodiment, the wear layer 12 is comprised of a melamine sheet, reinforced with aluminum oxide (AlO 2 ) and impregnated with a thermosetting resin. It is preferred, though not required, that the material selected to comprise the wear layer 12 be the same or similar material as that selected to comprise the backing layer 24 , if a backing layer 24 is utilized. Using “matched” materials for those layers has been found to minimize “warping” and “bowing” of the laminate material.
[0025] Alternatively, a layer of varnish or a UV curable scratch resistant coating may be used in place of the melamine sheet to comprise the wear layer 12 . As further alternatives, other materials providing suitable moisture resistance and resilience to loads and wear to which a floor is subjected may be utilized, such as phenolic resins or other natural, synthetic or recycled materials.
[0026] After manufacture of the laminate material, the wear layer 12 is substantially transparent, so that the aesthetic appearance of the decorative layer 14 is substantially unobstructed by the wear layer 12 . It has been determined that the inclusion of a wear layer 12 as the outermost layer of the laminate generally improves the resistance of the floor panel 10 to wear, including staining or fading of the aesthetic image imparted to the decorative layer 14 .
[0027] As illustrated in FIGS. 2 and 5, the outermost wear surface 26 , i.e., the top surface of the wear layer 12 that is exposed to the ambient environment, is provided with a textured surface condition. Thus, in addition to the decorative aesthetic image displayed by the decorative layer 14 , further aesthetic effect may be achieved by imparting depressions of a constant or variable depth to the wear surface 26 , arranged to display a desired texture pattern. For example, in the embodiment illustrated in FIG. 1 in which the decorative pattern is a wood grain, a texture pattern featuring depressions designed to simulate wood grain may be provided. As a further example, in an embodiment in which the decorative pattern is a simulated ceramic tile having tile portions surrounded by groutlines, a texture pattern having an irregular simulated stone texture and roughened or non-smoothed depressions to simulate recessed grout may be provided. These examples are merely illustrative and are not intended to be exhaustive. Other decorative patterns and texture patterns may be selected by the manufacturer or user according to aesthetic preference or design objectives. When referencing depressions, one skilled in the art will appreciate that this term excludes the edges circumscribing the panel and instead encompasses “depressions” within the periphery of the edges.
[0028] In the embodiment shown in FIG. 1A, the texture pattern is imparted to the floor panel 10 without regard to the positioning of the decorative pattern. Thus, in this embodiment, the wood grain pattern displayed in the decorative layer 14 (depicted in dashed lines in FIG. 1A) does not necessarily “match,” register with, or correspond to the wood grain pattern imparted as three-dimensional texture in the wear layer 12 (depicted in solid lines in FIG. 1A).
[0029] In another embodiment, shown in FIG. 1B, the texture pattern and the decorative pattern may be controlled during the manufacturing process such that the patterns “match.” In the hardwood floor panel example, therefore, the textured grain pattern may be imparted to wear layer 12 (solid lines) in registration with the visible grain pattern in the decorative layer 14 (dashed lines). In such an embodiment, lines of depression in the wear layer 12 are located adjacent or substantially on top of the printed grain lines in the decorative layer 14 of the laminate, providing an enhanced and more realistic aesthetic appearance.
[0030] As a further example, “knothole” patterns 30 in the decorative layer 14 are substantially overlaid by correspondingly shaped depressions in the wear layer 12 in FIG. 1 B. Thus, in this embodiment, the hard wood flooring design displayed by the decorative layer 14 includes the visual appearance of at least one knothole 30 . The wear surface 26 has at least one depression therein in registration with the knothole 30 . The knothole 30 may be of a variety of shapes. In one embodiment, the knothole 30 is substantially circular, and the corresponding depression in registration with the knothole 30 is also substantially circular in top plan view. Other embodiments are contemplated in which the knothole 30 has other shapes, such as an oval shape or some irregular shape similar to those found in natural hardwood planks. Such alternate embodiments are within the scope of the present invention.
[0031] In a currently contemplated hardwood embodiment, the depressions in the wear layer 12 in registration with the decorative pattern are imparted to a depth of at least 0.30 mm below the wear surface 26 . In another contemplated embodiment, the depressions in the wear layer 12 in registration with the decorative pattern are imparted to a depth of at least 0.50 mm below the wear surface 26 . In still another contemplated embodiment, the depressions are imparted to a depth of at least 1.0 mm below the wear surface 26 . In yet other contemplated embodiments, the depressions are imparted to a depth of at least 1.50 mm, 2.0 mm, 2.50 mm, or 3.0 mm, respectively, below the wear surface 26 . The possible width of the depressions is unlimited, but in presently preferred embodiments, widths of between approximately 1.0 mm and 25.0 mm have been utilized.
[0032] Similarly, in the simulated ceramic tile embodiment shown in FIGS. 4 and 5, the texture pattern may be imparted to the wear layer 12 in registration with the image imparted to the decorative layer 14 . In one embodiment, the ceramic tile design of the decorative layer 14 includes the visual appearance of at least one groutline 40 , and the wear layer 12 has at least one depression therein in registration with the groutline 40 . In embodiments where the groutline 40 imparted to the decorative layer 14 is substantially square in shape, the corresponding depression in registration with the groutline 40 is also substantially square in top plan view. In another embodiments, the groutline 40 may be provided in any selected pattern, including but not limited to triangular, hexagonal, octagonal, or other patterns. Such alternate embodiments are within the scope of the present invention.
[0033] In a currently contemplated simulated ceramic tile embodiment, the depressions in the wear layer 12 in registration with the groutline 40 are imparted to a depth below the wear surface 26 of at least 0.30 mm. In another contemplated embodiment, the depressions in the wear layer 24 in registration with the groutline 40 are imparted to a depth below the wear surface 26 of at least 0.50 mm. In still another contemplated embodiment, the depressions are imparted to a depth below the wear surface 26 of at least 1.0 mm. In yet other contemplated embodiments, the depressions are imparted to a depth of at least 1.50 mm, 2.0 mm, 2.5 mm, or 3.0 mm, respectively, below the wear surface 26 . The possible width of the depressions is unlimited, but in presently preferred embodiments, widths of between approximately 5.0 mm and 10.0 mm have been utilized.
[0034] Also in simulated ceramic tile embodiments of the present invention, a “rough” simulated stone texture may be imparted to the areas of the wear layer 12 overlaying the simulated stone image 42 in the decorative layer 14 . Further, any recessed depression in the wear layer 12 substantially overlaying the simulated groutline 40 in the decorative layer 14 may be provided with a “rough” simulated grout texture that is non-smooth visually and to the touch. This non-smooth and “rough” appearance more closely emulates the appearance of stone.
[0035] The selected texture pattern is usually, though not always, imparted to the wear layer 12 in a single manufacturing step, at the time the laminate layers are laminated together. In such an embodiment, the various laminate layers are positioned within a press (not shown) having a caul plate (also not shown) provided with an inverse impression of the selected texture pattern. After the laminate layers are positioned within the press, the caul plate is lowered to contact the wear layer 12 of the laminate. In a single step, under heat and pressure for a selected period of time, the layers are laminated together and the texture pattern is imparted to the wear layer 12 by the action of the caul plate. Through experimentation, it has been noted that satisfactory results may be obtained by the application of between 380-420 psi at between 350° F. -400° F. for a period of 18-60 seconds. These parameters are set forth by way of example only for an approximately 6.0 mm thick melamine wear layer product sold by the Mead Corporation. It is expected that any of these parameters will vary depending on the degree and depth of depressions sought to be imparted to the wear layer or depending on the characteristics of the selected wear layer material. One skilled in the art will appreciate that after experimentation, other parameters may produce similarly satisfactory results.
[0036] Alternatively, the texture pattern may be imparted to the wear layer 12 in a separate operation, after lamination of the various layers into a single workpiece.
[0037] The depth to which the wear layer 12 is depressed to provide the full texture patterns may be controlled during the manufacturing process. It is contemplated that to provide the most beneficial texture pattern, depressions of a depth at least 0.25 mm should be imparted to the wear layer 12 . More specifically, depressions of between 0.30 mm and 5.75 mm in depth, more preferably between 1.0 mm and 5.75 mm in depth, and most preferably between 1.5 mm and 5.75 mm in depth, measured from the nominal surface of the wear layer 12 , have been found to provide the greatest aesthetic effect while not diminishing performance of the overall floor system. These ranges are applicable in embodiments in which a melamine wear layer of approximately 6.0 mm thickness, manufactured by the Mead Corporation, is utilized. It has been found that depressions of a depth up to 0.25 mm less than the nominal thickness of such a wear layer 12 may be achieved using the above-described manufacturing methods; that is, if the nominal thickness is 5.0 mm, then the deepest depressions preferably should be no greater than 4.75 mm. In another preferred embodiment, the deepest depressions should be of a depth up to 0.50 mm less than the nominal thickness of the wear layer 12 .
[0038] It is expected that if other thicknesses, materials or manufacturing methods are selected to comprise the wear layer 12 , different preferred ranges may exist for each selected material.
[0039] Additional process controls or equipment may be required to manufacture flooring panels 10 according to embodiments of the invention in which substantial registration between the decorative pattern and the texture pattern are required. In a presently preferred embodiment, a short-cycle press manufactured by Wemhoner and operated by Stiles Machinery, 3965 44th St. S. E., Grand Rapids, Mich. 49512 has been found satisfactory for achieving such registration between the decorative pattern and the texture pattern.
[0040] During the manufacturing process, in one embodiment, the various separate layers are assembled in preparation for lamination. In the embodiment shown in FIG. 3, for example, a backing layer 24 , a core 16 , a decorative layer 14 and a wear layer 12 are stacked together before entering the press. Through processing equipment controls such as a single sheet alignment system and electrostatic bonding of the various laminate layers prior to entry into the press, alignment between the decorative pattern displayed by the decorative layer 14 and the texture pattern imparted to the wear layer 12 by the caul plate may be achieved within a tolerance of 0.125 inches.
[0041] As illustrated in FIG. 5, individual floor panels 10 according to the invention may be assembled to form a complete floor system. To facilitate assembly, individual floor panels may be provided with means for interlocking with adjacently placed panels. As shown in FIG. 1, each floor panel 10 may include a first pair of parallel sides 50 , 52 having tongue and groove cuts along the first and second parallel sides 50 , 52 , respectively. Each such floor panel 10 further includes a second pair of parallel sides 54 , 56 , perpendicular to each of the first pair of parallel sides 50 , 52 , also having tongue and groove cuts. Thus, each such floor panel 10 is capable of interlocking engagement with an adjacent panel. Alternatively, locking edge connections, such as that described in U.S. Pat. No. 6,006,486 to Moriau et al. (which is incorporated herein in its entirety by reference), may be utilized to form a floor covering system in which neighboring floor panels 10 are detachably secured to one another through a mechanical interlock.
[0042] Along the edges of the floor system, perimeter panels may be cut to length as needed to fit the installation environment and fitted with matching trim pieces (not shown) to provide an aesthetically attractive fit adjacent walls, stairs, doorways or other obstructions or transition areas.
[0043] In a presently preferred embodiment, individual floor panels 10 are manufactured to a width of 11½ inches and a length of 46{fraction (1/16)} inches, with an approximate thickness of {fraction (5/16)} inches. One skilled in the art will appreciate that other panel sizes may be used without departing from the scope of the invention.
[0044] Although the present invention has been described with reference to specific details of certain embodiments thereof, it is not intended that such details should be regarded as limitations upon the scope of the invention except as and to the extent that they are included in the accompanying claims. | A decorated floor panel having a core with a top surface and an opposite bottom surface; a decorative layer coupled to the top surface of the core, the decorative layer having a desired aesthetic appearance; and a wear layer coupled to and substantially covering the decorative layer for protecting the decorative layer. The wear layer has an exposed wear surface with depressions therein of a variable depth below the wear surface, the depressions being arranged to display a desired texture pattern. It is noted that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to ascertain quickly the subject matter of the technical disclosure. The abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims pursuant to 37 C.F.R. § 1.72(b). | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to tube pullers for gripping and removing tubes from surrounding structures. It is particularly useful in removing heat exchanger tubes from tubesheets for subsequent metallurgical evaluation.
2. Description of the Prior Art
Tube grippers for gripping and pulling tubes out of tubesheets are known in the prior art. Typically, such tube grippers include an expandable jaw which may be inserted into the open mouth of the tube. Such expandable jaws usually include a plurality of gripping teeth on their outside surfaces which grip the inside walls of the tube when the jaw is expanded. Thereafter, a hydraulic ram or an equivalent pulling means pulls the tube from its tubesheet.
While such tube pullers are able to satisfactorily remove tubes from tubesheets in a variety of applications, they are seriously deficient in maintaining the metallurgical properties of the tubes they withdraw. This is a particularly serious drawback in nuclear steam generators, where samples of heat exchanger tubes must be periodically withdrawn through the tubesheet separating the primary water system from the secondary water system in order to determine whether or not the tubes in that particular steam generator are afflicted with corrosion degradation. The mouth of such a tube is typically expanded between two and four inches into the tubesheet; the frictional force between such a tube and its tubesheet is so great that a tensile force as high as 10 metric tons may be required to pull the sample tube out from the tubesheet. If the exterior walls of the tube have been degraded and weakened by corrosion, the tensile force required to pull an expanding jaw of a conventional tube puller may cause the tube to break, thereby making it difficult, if not impossible, to determine the exact degree to which the wall of the sample tube was weakened by corrosion degradation. Even if the tensile force which the expanding jaw applies to the mouth of the tube is not sufficient to actually break the tube, the application of such a large tensile force across the cross-section of the tube walls will, at the very least, distort the metallurgical properties of the tube by exacerbating any flaws the tube may have along its radius.
Clearly, a need exists for a tube puller which is capable of quickly and effectively gripping and pulling the tubes in tubesheets without distorting the metallurgical properties of these tubes in the regions sought to be examined.
SUMMARY OF THE INVENTION
Generally speaking, the invention is both an apparatus and process for gripping and pulling tubes without altering the metallurgical properties of the tubes. The invention accomplishes its purpose by means of a tube puller having upper and lower relatively movable grippers. While the invention is particularly adapted for removing sample tubes from tubesheets, it may more generally be used for removing any elongated structure which is frictionally engaged to a surrounding structure.
The apparatus of the invention comprises an upper and lower gripping means for gripping the ends of a longitudinal section of the tube, and a pulling means operatively connected to each of the gripping means. In operation, the apparatus is inserted into an open end of the tube, and the lower gripping means is engaged into the inner walls of the tube near its open end. Next, the upper gripping means is likewise engaged into the inner tube walls at a point further from the open end. The pulling means then applies a tensile force to the lower gripping means located near the open end of the tube. This tensile force has the effect of contracting the diameter of the tube a small amount in the longitudinal section of the tube located between the two grippers. When this plastic contraction in the diameter of the tube has been accomplished along the entire longitudinal section, the tensile force applied by the pulling means is shared by both the upper and lower gripping means, which has the effect of substantially isolating the longitudinal section between the grippers from the tensile force. The tube is then withdrawn from the tubesheet with no significant alterations in the metallurgical properties in the section between the tube grippers.
The apparatus of the invention may include an extendable connecting assembly for mechanically linking the upper and lower gripping means in tandem. The connecting assembly may be slidable between a contracted position and an extended position. More specifically, the connecting assembly may include an outer sleeve where the lower gripping means is located, and a middle sleeve telescopingly engaged to the outer sleeve where the upper gripping means is located. The middle sleeve may be freely slidable within the outer sleeve between the aforementioned contracted and extended positions. The distance between the contracted and extended positions is large enough so that the tube puller will contract the diameter of the tube being pulled enough to relieve a substantial amount of the frictional forces between the tube and the tubesheet, but small enough so that the metallurgical properties of the tube are not significantly altered.
The lower gripping means may include a self-tapping thread which may be threadedly engaged within the mouth of the tube adjacent the tubesheet. The upper gripping means may include an expandable collet having a plurality of barbed threads on its outside surface for releasably gripping the inside surface of the tube. The expandable collet may be formed from a high strength, resilient material such as 17-4 PH stainless steel, and may further include an expander member slidably movable within the mouth of the collet for expanding and contracting the diameter of the collet. The expander member may further be connected to an inner shaft which is concentrically disposed and slidably mounted within the middle and outer sleeves of the connector assembly. Finally, the inner shaft may be connected to an expander assembly which includes a nut having a left-handed thread.
In the process of the invention, a double-gripper tube puller as heretofore described may be inserted into the open mouth of a tube surrounded by a tubesheet. Next, the open mouth of the tube may be gripped by the self-tapping threads of the lower gripping means. Thereafter, the telescopically movable middle sleeve of the connecting assembly may be withdrawn into a contracted position by means of a gauge, for example. The upper gripping means may then be used to grip a portion of the interior wall of the tube which is located well inside the mouth portion of the tube. A hydraulic ram may then apply a tensile force onto the lower gripping means of the tube puller in order both to plastically contract the diameter of the tube a small amount between the lower and upper gripping means. This tensile force also has the effect of elongating the tube in this region a small amount, thereby bringing the middle sleeve of the connecting assembly from the aforementioned contracted position to a fully extended position. In the final step of the process, the tensile load applied to the tube puller by the hydraulic ram is shared by the upper and lower gripping means of the tube puller, and the tube is pulled out of the tubesheet.
BRIEF DESCRIPTION OF THE SEVERAL FIGURES
FIG. 1 is a partial cross-sectional side view of the tube puller of the invention;
FIG. 1A is an enlarged view of the threaded portion of the lower gripper;
FIG. 2 is a cross-sectional view of line II--II through the threaded portion of the lower gripper of the tube puller illustrated in FIG. 1A;
FIG. 3 is a side view of the expander member and lower part of the middle sleeve of the invention;
FIG. 4 is an exploded, partial cross-sectional side view of the expander base of the invention;
FIG. 5A is a cross-sectional view along line B--B in FIG. 4;
FIGS. 5B, 5C, 5D and 5E illustrate the rear faces of the base of the outer sleeve and the expander base, the front face of the expander nut, and the rear face of the expander disc, respectively;
FIG. 6 is a front view of the spacer gauge of the invention, and
FIG. 7 is a side, partial cross-sectional view of the gripper inside a heat exchanger tube.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to FIGS. 1, 1A and 2, wherein like numerals represent like parts, the tube puller 1 of the invention generally comprises a lower gripper 3 which may be screwed into the mouth of a tube to be removed, an upper gripper 25 having an expandable collet 28, and an expander base 57 for selectively expanding the collet 28. Generally speaking, the lower gripper 3 and the upper gripper 25 are linked together in tandem by means of an extendable connecting assembly 2. This connecting assembly 2 is formed from an outer sleeve 5 which carries the lower gripper 3, and a middle sleeve 26 which carries the upper gripper 25. Middle sleeve 26 is slidable for a short distance within the outer sleeve 5; consequently, the upper gripper 25 is extendable or contractable a short distance (illustrated by gaps 45 and 63) with respect to lower gripper 3. The longitudinal movement provided by the slidably mounted middle sleeve 26 in outer sleeve 5 is highly advantageous, because it allows the lower gripper 3 of the tube puller 1 to exert a tensile force on the mouth portion of the tube before both grippers 3 and 25 simultaneously grip and pull the tube. When the puller is used to remove a tube from the tubesheet in a steam generator, such a longitudinal action is particularly advantageous, since it allows the tensile force applied to the lower gripper 3 to plastically relax the two- to four-inch end portion of the tube which has been expanded into the tubesheet.
The lower gripper 3 generally includes outer sleeve 5 which extends between stop member 39 and base 17. The distal end of the outer sleeve 5 includes a threaded portion 7 having a plurality of barbed, self-tapping threads 9 which may best be seen in FIG. 1A. In the preferred embodiment, each of the threads 9 is a sharpened, buttress-type thread. For any given engagement pressure, the barbed profile of the threads 9 grip the inside walls of the tube better than threads having a conventional triangular profile, because the sharp edges of the barbed profile will allow the tips of the threads 9 to more easily penetrate the inner walls of the tube when the threaded portion 7 of the lower gripper 3 is screwed into the tube mouth. Such penetration, of course, serves to ensconce the teeth 9 more securely into the wall of the tube being pulled, thereby increasing the shear stress area in the tube. Consequently, the provision of a barbed thread profile, in lieu of a conventional triangular thread profile, allows the threaded portion 7 of the gripper 3 to apply a maximum amount of tensile force onto the inside surface of the tube being pulled for a minimum amount of screw-torque. The minimization of this screw-torque in turn insures that the engagement of the lower gripper 3 into the mouth of a selected tube will not significantly expand the tube within the tubesheet, and increase the frictional engagement between the tube and the tubesheet.
As may best be seen in FIG. 2, the threaded portion 7 of the lower gripper 3 includes a longitudinally oriented, tapping recess 11. This recess 11 provides the threads 9 with a cutting edge 12 to present to the inside wall of the tube being pulled. Additionally, the space which forms the tapping recess gives the metal shavings formed from the tapping process a place where they may accumulate without obstructing the tapping process. Preferably, threaded portion 7 is formed from 17-4 PH hardened stainless steel, so that the lower gripper 3 of the puller 1 may easily tap into the mouth of a nickle-iron-chromium tube of the type commonly used in nuclear steam generators.
With reference now to FIGS. 1, 4 and 5A, the proximal end of outer sleeve 5 includes a nut portion 13 formed from a pair of flat, wrench-receiving surfaces 15a, 15b. The nut portion 13 provides an area which may be firmly grasped by the jaws of an open-end wrench when the operator of the puller 1 desires to screw the lower gripper 3 into the mouth of the tube. The proximal end of outer sleeve 5 terminates in a base portion 17. The base portion 17 includes a female receiver 19 for receiving the male member 59 of the expander base 57. As is most easily seen in FIGS. 4 and 5B, female receiver 19 is formed by a pair of parallel, chord-shped lugs 21a, 21b. As is best seen in FIGS. 5A and 5B, outer sleeve 5 also includes a concentrically disposed bore 23 for slidably receiving the middle sleeve 26 of the upper gripper 25.
With reference now to FIGS. 1 and 3, the preferred embodiment of the tube gripper 1 further includes an upper gripper 25 disposed on the distal portion 27 of the middle sleeve 26. Upper gripper 25 includes an expandable collet 28 having a frusto-conical interior 29 which tapers into a cylindrical bore 30. The exterior 31 of the expandable collet 28 is threaded with a plurality of barbed, self-tapping threads 33 having much the same profile as the barbed threads of outer sleeve 5. Preferably, the expandable collet 28 includes five longitudinal slots 35a, 35b, 35c, 35d and 35e (not shown) equidistantly disposed around its circumference. These longitudinal slots allow expandable collet 28 to resiliently flex in response to longitudinal movement of expander member 48. Each of these longitudinal slots 35a, 35b, 35c, 35d and 35e preferably terminates in a stress-relieving keyhole 37a, 37b, 37c, 37d and 37e, respectively. These keyholes effectively dissipate the stress concentrated at the base of the aforementioned longitudinal slots when the frustro-conical body 50 of the expander member 48 is pulled backwards. In the preferred embodiment, the longitudinal sections of the collet 28 defined by the slots 35a, 35b, 35c, 35d and 35e each taper inwardly slightly in their unexpanded state, so that they will form a substantially cylindrical body when the frustro-conical body 50 of the expander member 48 is drawn into the interior 29 of the collet 28. In this way, each of the threads 33 of the upper gripper will engage the interior walls of the tube when the collet 28 is expanded.
Expander member 48 includes a frustro-conical body 50 at its distal end which tapers into a shaft 51. The shapes of the frustro-conical body 50 and the inner shaft 51 are complementary to the frustro-conical interior 29 and cylindrical bore 30, and the body 50 and inner shaft 51 are normally disposed in the interior 29 and bore 30 to a greater or lesser extent, depending upon whether the user wishes to expand collet 28. The inner shaft terminates on its proximal side in a threaded end 53 which is engageable within the threaded bore 90 of expander disc 88.
Centrally disposed in the middle sleeve 26 is stop member 39. As previously indicated, stop member 39 limits the amount of longitudinal, telescoping "play" between outer sleeve 3 and inner sleeve 26. More specifically, the slidable longitudinal movement between the outer sleeve 3 and the middle sleeve 26 is limited on the left side by stop member 39 near the middle of the puller 1, and on the right side by the male member 59 of the expander base 57. As is best seen in FIG. 3, the proximal end of the middle sleeve 26 terminates in a threaded portion 47. This threaded portion 47 is normally screwed into a female threaded bore 65 in the expander base 57.
With reference now to FIGS. 1, 4, 5C, 5D and 5E, the expander assembly 55 of the invention 1 includes a expander base 57, a expander nut 75, and a expander disc 88 having a pair of dowel pins 94a, 94b slidably movable within complementary bores 69a, 69b in the base 57.
The front portion of expander base 57 includes the previously discussed male member 59 which is receivable within female receiver 19 at the base 17 of outer sleeve 3. Preferably, the length of male member 59 is slightly longer than the length of the chordal-shaped lugs 29a, 29b which form the female receiver 19, so that the front of the male member 59 will always engage the rear face of the female receiver 19 when the upper gripper 25 is in its most extended position. Such dimensioning controls stoppage of the telescopic movement between the outer sleeve 5 and the middle sleeve 26 by insuring that the front face of the male member 59 will always first seat against the rear face of the female receiver 19, before the lugs 21a, 21b of the female receiver 19 contact the shoulders 61a, 61b of the male member 59. In its interior, expander base 57 includes a centrally disposed threaded bore which extends about two-thirds down its longitudinal axis from male member 59. As is best seen in FIG. 1, this female threaded bore 65 receives the threaded portion 47 of the middle sleeve 26, and thereby secures it within the expander assembly 55. Throughout the last third of its longitudinal axis, expander base 57 includes a relatively narrow smooth bore 67 which opens into the female threaded bore 65 as shown. Smooth bore 67 receives the proximal end 52 of the inner shaft 51 of expander member 48, as illustrated in FIG. 1. As is best seen in FIGS. 4 and 5C, the smooth, centrally disposed bore 67 of expander base 57 is flanked by two other smooth bores 69a, 69b. As previously indicated, bores 69a, 69b slidably receive dowel pins 94a, 94b of disc 88. On its outside, expander base 57 includes a left-handed thread 79 for receiving the threads of nut 75, as well as an annular stop member 71 for limiting the degree to which nut 75 may be withdrawn along the longitudinal axis of expander base 57. Specifically, when expander nut 75 is screwed backwards to its outermost limit, annular shoulder 81 of the nut 75 will engage the annular stop 71 and prevent the nut 75 from being screwed back any further. The stopping function of annular stop 71 is most clearly seen with reference in FIG. 1.
With specific reference now to FIGS. 4 and 5D, expander nut 75 includes a hexagonal exterior 77 which may be easily grasped and turned by the jaws of a conventional wrench. The distal interior portion of nut 75 includes a left-handed threaded 79 which is complementary to the left-handed thread 71 of the expander base 57. The proximal portion of the inside of nut 75 includes an annular recess 83 which, as will presently be seen in more detail, defines the extent to which the frustro-conical body 50 of the expander member 58 may be pulled through the mouth of expandable collet 28 via inner shaft 51. The annular recess 83 of nut 75 is separated from the interior left-handed thread 78 via annular shoulder 81, which coacts with annular stop 71 of expander base 57 to stop the rearward motion of the nut 75 in the manner previously described. The provision of a left-handed thread in the expander base 57 and nut 75 serves two functions. First, it insures that the torque applied to the tube puller 2 when the expander member 48 of the upper gripper 25 is withdrawn into the interior 29 of the collet 28 will serve to tighten, rather than loosen, the threads 9 of the lower gripper from the inside of the tube. Secondly, the inventors have noticed a tendency on the part of persons operating such tube pullers to turn the expansion nuts of the upper gripper in a clockwise direction to secure the upper gripper into the tube, as though they were tightening a screw. Hence, the provision of a left-handed thread on nut 75 insures that this tendency toward a clockwise rotation of the nut will in fact expand the collet 28 inside the tube, rather than loosen it, as would a right-handed thread.
With reference now to FIGS. 1, 4 and 5E, the last major component of the puller assembly is the expander disc 88. As previously indicated, the disc 88 includes a central, threaded bore 90 which receives the threaded end of inner shaft 51 of expander member 48. Flanking threaded bore 90 is a pair of dowel pins 94a, 94b which are securely mounted within complementary bores 92a, 92b. The dowel pins 94a, 94b isolate the screw joint between the threaded end of inner shaft 51 and threaded bore 90 of disc 88 from the torsional forces which the annular surface 85 of the nut 75 exerts onto the disc 88 when the nut 75 is twisted.
With reference now to FIG. 6, the final component of the tube puller 1 of the invention is the spacer tool 100. Spacer tool 100 is generally Y-shaped, having two arms 102a, 102b extending from a single leg 105. In the preferred embodiment, the arms 102a, 102b and leg 105 of the tool 100 are approximately 0.05 in. thick. Additionally, the tip ends of the arms 104a, 104b are preferably tapered so that the spacer tool may be easily slid in the gap 63 between the lugs 21a, 21b of the base 17 of the outer sleeve 3, and the shoulders 61a, 61b flanking the male member 59 of the puller base 57. When the Y-shaped spacer tool 100 is slid into the tube puller 1 in this fashion, the middle sleeve 26 carrying the upper gripper 25 is in its most longitudinally contracted position with respect to lower gripper 3.
A conventional hydraulic ram 117 (schematically represented) is used to exert a tensile force onto the lower gripper 3 of the tool 1. Such rams are capable of exerting a tensile force of over 10 metric tons onto the tool 1, which is sometimes necessary to pull a heat exchanger tube out of a tubesheet.
FIG. 7 illustrates the preferred process of the invention. Here, a tube puller 1 as heretofore described is inserted into the open end of a tube 110 frictionally engaged within a tubesheet 112. In this example, the tube 110 and tubesheet 112 are of the type typically used in a nuclear steam generator. In such generators, the heat exanger tubes 110 are usually expanded around their open ends to form a frictional joint 111 between the tube 110 and the tubesheet 112. Additionally, there is usually a small annular gap 13 between the tube 110 and the tubesheet 112 above the joint 111. Boron salts and other corrosive materials sometimes accumulate in this annular region 113, and cause the walls to corrosively degrade in the longitudinal portion 114 of the tube 110 between the top of the joint 111, and the top surface of the tubesheet 112. Because the tube 110 may be weakened in this region 114, it is important that this region be isolated as much as possible from large tensile forces which can break the tube 110, or, at the very least, negatively distort its metallurgical properties so much in the region 114 that a representative sample is not obtained. Exactly how the gipper 1 of the invention accomplishes this desired result will become evident from the following description of the process of the invention.
After the gripper 1 is inserted into the tube 110, the lower gripper 3 is then engaged within the mouth of the tube by screwing the threaded portion 7 into the inner walls of the tube. In the case of a tube in a nuclear steam generator that has been expanded for a distance of two to four inches around the mouth of the tube in order to secure the tube into the tubesheet, the threaded portion 7 of the lower gripper will preferably overlie this expanded region. The lower gripper 3 is screwed into the tube mouth by grasping nut protion 13 of the outer sleeve 5 with the jaws of an open-end torque wrench and twisting the entire puller 1 in a clockwise direction. This twisting motion continues until the lower gripper 3 is twisted to a desired torque. Such a twisting motion screws the barbed, self-tapping threads 9 of the outer sleeve 5 securely into the inner walls of the tube 110.
Next, in order to insure that the lower gripper 3 will provide tension across the joint 111 of the tube before the upper gripper 25 comes into play, the blades 104a, 104b of the Y-shaped spacer tool are inserted into the gap 63 between the base 17 of the outer sleeve 3 and the shoulders 61a, 61b of the puller base 57. The insertion of the spacer tool 100 telescopically extends the outer sleeve 3 over the middle sleeve 26 to its most extreme, extended position, which abuts the distal end of sleeve 3 against the stopping member 39, thereby completely eliminating any gap 45 between the two. Such positioning between the outer sleeve 3 and the middle sleeve 26 brings the upper gripper 25 to its closest position to the lower gripper 3.
After the grippers are brought into their closest position with respect to one another, the upper gripper 25 is engaged to the inner walls of the tube 110 by rotating nut 75 in a clockwise direction. Because nut 75 engages expander base 57 through left-handed threaded 79, nut 75 moves backwards along the longitudinal axis of the tool 1, thereby drawing the inner shaft 51 of the expander member 48 along with it. Consequently, the barbed threads 33 on the fingers of the expandable collet 28 are pushed outwardly by the frustro-conical body 50 of the expander member 48, which causes them to grippingly engage the interior walls of the tube 110 in the position shown. Preferably, the rotation of nut 75 is accomplished by means of a torque wrench, and the nut 75 is twisted until a desired torque is reached.
In the final steps of the preferred process of the invention, the Y-shaped spacer tool 100 is removed, and the previously-mentioned hydraulic ram 117 of conventional manufacture is detachably mounted around the base 17 of the outer sleeve 5. The cylinders of the hydraulic ram 117 are then actuated, which causes the lower gripper 3 of the tube puller 1 to immediately exert a tensile force on the open end of the tube 110 being pulled. However, because of the small amount of "play" between the outer sleeve 5 holding the lower gripper 3, and the middle sleeve 26 holding the upper gripper 25, no tensile force is applied onto the tube through the upper gripper 25 until the tube has been slightly longitudinally stretched the length of the gap 63 left in the puller assembly by the Y-shaped spacer tool 100. This tensile force causes a very small but significant plastic deformation in the tube which has the effect of slightly decreasing its radial cross-section of the tube 110 in the region of the joint 111. This plastic deformation relaxes the expansion joint 111 between the tube 110 and tubesheet 112. This relaxation of the expansion joint 111, and decrease in the radial cross-section of the tube 110 in turn reduces the amount of frictional engagement between it and the surrounding tubesheet 112. After this very slight radial contraction of the tube has taken place, the middle sleeve 26 is extended to its most extreme position within outer sleeve 5, which in turn causes the connecting assembly 2 of the tube puller to effectively transfer tensile force simultaneously between the hydraulic ram and both the lower and upper grippers 3 and 25. Both the upper gripper 25 and lower gripper 3 then share the tensile load.
It should be noted that the sharing of the tensile load by the upper and lower grippers 25 and 3 essentially isolates the region 114 of the tube 110 between the two grippers 3 and 25 from significant amounts of tensile force. Viewed another way, the upper gripper 25 applies a compressive force on the longitudinal region 114 of the tube 110 which cancels out the tensile force applied to this region by the lower gripper 3. From either perspective, the invention produces the desired effect of preserving the metallurgical properties of the tube in region 114. | Both an apparatus and a process for pulling tubes from a tubesheet with two relatively movable gripping means are disclosed herein. The apparatus of the invention is a tube puller which has upper and lower gripping means for gripping the section of the tube surrounded by the tubesheet. The two gripping means are mechanically linked together by means of an extendable connecting assembly. This assembly includes an outer sleeve where the lower gripping means is located, and a middle sleeve where the upper gripping means is located which is slidable a predetermined distance within the outer sleeve. In the process of the invention, a tube puller as heretofore described is inserted into the mouth of a tube. The lower gripping means is then engaged to the mouth of the tube. The upper gripping means is then engaged in a section of the tube beyond the tube mouth with the extendable connecting assembly in a contracted position. A pulling means including a hydraulic ram then applies a tensile force onto the lower gripping means in order to pull on the mouth of the tube and to plastically contract the outer diameter of the tube in the vicinity of the tubesheet. After such contraction occurs, the connecting assembly between the two gripping means extends to its maximum length, and the pulling means applies a tensile force to both the upper and lower gripping means. Both of the gripping means then coact to withdraw the tube from the tubesheet. The invention preserves the metallurgical properties of the section of tube between the two grippers, which is important when the tubes are being sampled for corrosion degradation. | 1 |
CROSS REFERENCE TO RELATED APPLICATION
This utility patent application is based upon, and claims the filing date of, prior U.S. Provisional application entitled “Sliding Valve Aspiration Engine,” Ser. No. 61/135,267, filed Jul. 18, 2008, by inventor Gary W. Cotton.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to sleeve valve systems for aspirating internal combustion engines, and to internal combustion engines with tubular sliding valves for enhanced aspiration. More particularly, the present invention relates to reciprocating sleeve valve systems and engines equipped therewith of the general type classified in United States Patent Class 123, Subclasses 84, 188.4, and 188.5.
2. Description of the Related Art
A variety of aspiration schemes are recognized in the internal combustion motor arts. In a typical four-cycle firing sequence, gases are first inputted and then withdrawn from the combustion chamber of each cylinder interior during reciprocating piston movements caused by the crankshaft. Gas pathways must be opened and closed during a typical cycle. During the intake stroke, for example, an air/fuel mixture is suctioned through an open intake passageway into the combustion chamber as the piston is drawn downwardly within the cylinder. The intake passageway is typically opened and closed by some form of reciprocating valve mechanism that is ultimately driven by mechanical interconnection to the crankshaft. The combustion chamber must be sealed during the following compression and power strokes, and the valve mechanisms must be closed to block the ports. During the following exhaust stroke, exhaust ports must be opened to discharge spent gases from the combustion chamber.
Spring-biased poppet valves are the most common form of internal combustion engine valve. Typically, poppet valves associated with the intake and exhaust passageways are seated within the cylinder head above the combustion chamber proximate the cylinder and piston. Typical reciprocating poppet valves are spring biased, assuming a normally closed position when not deflected. In a typical arrangement, the bias spring coaxially surrounds the valve stem to maintain the integral valve within the matingly-configured valve seat. Poppet valves are typically opened by mechanical deflection from valve train apparatus driven by camshafts. Typical overhead-valve motor designs include rocker arms comprising reciprocating levers driven by push rods in contact with camshaft lobes. When the camshaft lobe deflects a pushrod to raise one end of the rocker arm, the opposite arm end pivots downwardly and opens the valve. When the camshaft rotates further, the rocker arm relaxes and spring pressure closes the valve. With overhead-cam designs camshafts are disposed over the valves above the head, and valve deflection is accomplished without push rods or rocker arms. Overhead camshafts push directly on the valve stem through cam followers or tappets. Some V-configured engines use twin overhead camshafts, one for each head. Some enhanced DOHC designs use two camshafts in each head, one for the intake valves and one for the exhaust valves. The camshafts are driven by the crankshaft through gears, chains, or belts.
Despite the overwhelming commercial success of poppet-valve designs, there are numerous deficiencies and disadvantages associated with poppet valves. Although poppet valve designs provide manufacturing advantages and cost savings, substantial spring pressure must be repeatedly overcome to properly open the valves. Spring pressure results in considerable drag and friction which increases fuel consumption and limits engine RPM. Poppet valve heads are left within the fluid flow passageway, despite camshaft deflection, and the resulting obstruction in the gas flow pathway promotes inefficiency. For example, back pressure is increased by the valve mass obstructing fluid flow, which contributes to turbulence. Poppet valves are exposed to high combustion chamber temperatures, particularly during the exhaust stroke, that can promote deformation and wear. Thermal expansion of exhaust valves, for example, can interfere with proper valve seating and subsequent sealing, which can decrease combustion performance.
Many of these disadvantages are amplified in high-horsepower or “high R.P.M.” applications. Valve deflection in high power applications is often extreme, increasing the amplitude of valve defection or travel. Damaging valve-to-piston contact can result. As a means of attenuating the latter factor, some pistons are designed with valve clearance regions, but these piston surface irregularities can deleteriously affect the combustion charge and fluid flow through the combustion chamber. Another problem is that the applied drive forces experienced by the valves are asymmetric. The extreme forcing pressure applied by the camshaft to open the valves, for example, is not as uniform as the spring closing pressure. Disharmony between the opening and closing forces contributes to valve lash and concomitant timing problems that interfere with power generation and limit engine R.P.M. Of course, in high power systems involving four or more valves per cylinder, the problems and disadvantages with poppet valve engines are increased proportionally.
So-called “rotary valves” have been proposed for replacing reciprocal poppet valves. Typical rotary valve designs include an elongated tube or cylinder machined with a plurality of gas flow passageways that admit or pass gases. The rotary valves are not reciprocated; the are rotated about their axis to expose passages defined in them in directions normal to their longitudinal axis. Rotary valves must be timed properly to dynamically align their internal passageways with the fluid flow paths of the engine during operation. When rotated to a closing position, the rotary valve passageways are radially displaced, obstructing the normal flow pathways and sealing the engine for firing or compression strokes.
One advantage espoused by rotary valve proponents is the relative simplicity of the design. Further, rotary valves do not penetrate or extend into the cylinder, avoiding potential mechanical contact with the piston, and minimizing fluid flow obstructions. However, the biggest problem with rotary valves relates to ineffective sealing. Although much activity and research has been directed to rotary valve sealing designs, commercially feasible systems have not been perfected. Rotary systems provide inefficient cylinder sealing, lessening firing efficiency, and reducing compression pressure because of leakage. Further, rapid wear of such systems increases the aforementioned problems.
Sliding valves of many configurations are also known in the art. Typical slide valves may be hollow and tubular, or planar, or cylindrical. They are reciprocated within a tubular valve seat region proximate the combustion chamber to alternately open and then close the intake and exhaust passageways. Like rotary valves, sliding valve designs have hitherto been difficult to seal effectively, with predictable negative results.
U.S. Pat. No. 2,080,126 issued May 11, 1937 to Gibson shows a sliding valve arrangement involving a tubular valve driven by a secondary crankshaft. Its reciprocating axis is parallel to the axis of piston deflection. Ports arranged at the side of the piston are alternately opened and closed by piston movements, and gases are conducted through and around portions of the piston exterior.
A similar arrangement is seen in U.S. Pat. No. 1,995,307 issued Mar. 26, 1935, and U.S. Pat. No. 2,201,292, issued May 21, 1940, both to Hickey. The latter patents show designs that aspirate a single working cylinder with a pair of tubular, reciprocating valves that are mounted on either side of the piston and driven by secondary crankshafts. The aspirating valves are forcibly reciprocated between port blocking and port aligning positions. The valves are aligned at an angle slightly off of parallel with the axis of the cylinder.
Other examples of engines with tubular, reciprocating slide valves that move in a direction generally parallel with the drive piston axis are provided by U.S. Pat. Nos. 1,069,794; 1,142,949; 1,777,792; 1,794,256; 1,855,634; 1,856,348; 1,890,976; 1,905,140; 1,942,648; 2,160,000; and 2,164,522 that are largely cumulative.
Hickey U.S. Pat. No. 2,302,442 issued Nov. 17, 1942 shows a tubular, reciprocating sliding valve disposed atop a piston head. The valve slides in an axis generally perpendicular to the axis of the lower drive piston.
U.S. Pat. No. 5,694,890 issued to Yazdi on Dec. 9, 1997 and entitled “Internal Combustion Engine With Sliding Valves” discloses an internal combustion engine aspirated by slidable valves. Tapered, horizontally disposed valve seats are defined near inlet and exhaust ports at the top of the combustion chambers. The slidable valves are tapered to conform to the valve seats. Valve movement is caused by a crankshaft driving a rocker arm that is oriented substantially orthogonal to the rod, whereby crankshaft rotation is translated into horizontal, sliding movements of the planar valves, which reciprocate in a direction normal or transverse to the axis of the piston.
U.S. Pat. No. 7,263,963 issued to Price on Sep. 4, 2007 and entitled “Valve Apparatus For An Internal Combustion Engine” discloses a cylinder head with a cam-driven valve slidably disposed within a valve pocket. The valve, which is displaceable along its longitudinal axis has a tapered portion defining multiple fluid flow passageways. The valve is displaced by cam rotation between a configurations passing gases through the passageways and a configuration wherein the valve flow passageways are closed.
BRIEF SUMMARY OF THE INVENTION
This invention provides an improved sliding valve system for aspirating internal combustion engines, and engines equipped therewith. The system employs tubular, reciprocating sliding valves disposed within sleeves defined within the head secured above the motor's reciprocating pistons. The valves are driven by an independent crankshaft that is exteriorly driven through a pulley.
The sliding valves are positioned within suitable exhaust and intake tunnels in the head. Preferably sleeves are concentrically disposed around the valves and concentrically fitted within the tunnels. Fluid flow through the valves results through ports defined in the body of the tubular slide valves that are aligned with similar ports in their sleeve, that are in turn aligned with ports dynamically positioned above the compression or combustion region of the cylinder located below the head. Gas pressure develops shearing forces on valve sides. Gases are routed through the tubular interior of the sliding intake valve or valves during intake strokes, and exhaust gases are likewise forced out of the combustion cylinder through the interior of the exhaust valve or valves during exhaust strokes. Pressured gases traveling longitudinally through the valve interior passageways are inputted or outputted through lateral valve ports in fluid flow communication with the internal valve passageways.
Rather than pressuring faces of the valves in a direction normal to valve travel, exhaust and intake gas forces are directed against sides of the valves. To minimize potentially detrimental forces applied across the valves during, for example, the critical exhaust stroke, the valve body includes at least one reduced diameter portion forming a relief annulus within the valve chamber that distributes potential shearing pressure about the circumference of the valve. High pressure gas is confined between axially spaced apart sealing rings that prevent gases from flowing axially about the valve exterior.
All intake and exhaust gas flow is thus confined within the tubular interior of the valves. As a result, gas pressure does not develop a substantial resistive force upon leading surfaces of the valve in a direction coincident with the direction of valve travel. Instead gas pressure that might otherwise resist valve travel, and add to friction, is applied as a shear force, and pressure is evenly distributed in the relief annulus. Gas flow is distributed through the valve interior rather than around it, and friction is substantially reduced.
Importantly, the port sizes are maximized for efficient breathing. However, in the past, large sliding valve ports have contributed to inefficiency, reduced sealing, and premature valve failure. In the present design, the slide-valve sleeves are provided with a unique connecting bridge that traverses the port area, aligned with the direction of sliding valve travel. When the valves slidably reciprocate through this region, their sealing rings are supported tangentially by the bridges, to maintain ring integrity.
Thus a basic object of my invention is to provide a highly efficient aspiration or valve system for internal combustion engines, particularly four-cycle designs.
A related object is to provide an improved four cycle, internal combustion engine.
A related object is to improve combustion efficiency within an internal combustion engine. It is a feature of our invention that its advantageous overhead valve geometry and the reduction of valve-train parts needed for the invention increase overall efficiency.
Another important object is to preserve the sealing integrity of sliding valves. One important feature of the invention in this regard is that the head ports are provided with bridges that support the valve sealing rings during motion.
Another basic object is to provide a valve system for internal combustion engines that provides an enhanced power stroke. In other words, it is a feature of this invention that a higher proportion of the total 720 degrees of crankshaft rotation during typical four cycle operation occurs during the power stroke.
Another important object is to provide a sliding valve system of the character described that does not affect combustion chamber volume during operation. Important features of my invention are the fact that chamber expansion during valve displacement is avoided, and that the porting path does not consume the operational compression volume.
A related object is to provide a valve system of the character described wherein the valve structure does not enter the combustion chambers.
Another object is to provide a valve deflection system that applies force symmetrically, to minimize valve lash and allow higher engine speeds.
Yet another basic object is to minimize friction. It is a feature of my invention that spring-biased poppet valves and the typical frictional cam shafts and associate linkages such as rocker arms used to reciprocate poppet valves are avoided.
A still further object is to provide a valve system of the character described that is driven externally by a belt, so that efficiency is increased and complexity is reduced.
Another important object is to avoid so-called split-lift” applications used in the prior art for aspirating motors.
These and other objects and advantages of the present invention, along with features of novelty appurtenant thereto, will appear or become apparent in the course of the following descriptive sections.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
In the following drawings, which form a part of the specification and which are to be construed in conjunction therewith, and in which like reference numerals have been employed throughout wherever possible to indicate like parts in the various views:
FIG. 1 is a fragmentary isometric view of a one-cylinder internal combustion engine constructed in accordance with the best mode of the invention known at this time;
FIG. 2 is an enlarged, fragmentary, plan view of the engine taken generally from a position to the right of FIG. 1 and looking left, with portions thereof broken away or shown in section for clarity;
FIG. 3 is an enlarged, fragmentary sectional view taken generally along line 3 - 3 of FIG. 2 ;
FIG. 3A is a greatly enlarged, fragmentary view of circled region 3 A in FIG. 3 ;
FIG. 4 is an enlarged, fragmentary, isometric view of the preferred cylinder head assembly, with portions thereof broken away or shown in section for clarity or omitted for brevity;
FIG. 4A is a greatly enlarged, fragmentary view of circled region 4 A in FIG. 4 ;
FIG. 5 is an enlarged, partially exploded fragmentary isometric view of the cylinder head assembly of FIG. 4 , with a sliding valve removed from its sleeve, and with portions thereof broken away or shown in section for clarity;
FIG. 6 is an enlarged, fragmentary isometric view taken generally from circled region “ 6 ” in FIG. 5 ;
FIG. 7 is an enlarged bottom isometric view of the preferred cylinder head;
FIG. 8 is an enlarged isometric view of a preferred spool valve, with portions thereof broken away or shown in section for clarity;
FIG. 9 is a side elevational view of a preferred spool valve;
FIG. 10 is an end elevational view of the spool valve of FIG. 9 , looking generally in the direction of arrows 10 - 10 ;
FIG. 10A is a longitudinal sectional view of a preferred spool valve, derived generally in the direction of arrows 10 A- 10 A in FIG. 10 ;
FIG. 11 is an enlarged top plan view of the preferred cylinder head, with phantom lines illustrating various internal parts, and with portions broken away or shown in section for clarity;
FIG. 12 is an enlarged, fragmentary diagrammatic view showing the basic arrangement of the engine power cylinder, the head, the overhead spool exhaust valve, and the exhaust valve sleeve;
FIGS. 13-15 are diagrammatic views of progressive intake spool valve movements during the intake stroke as the power crankshaft rotates;
FIG. 16 is a diagrammatic view showing the intake spool valve position when the spark plug fires at the beginning of the power stroke;
FIG. 17 is a diagrammatic view showing the intake spool valve position at the bottom of the power stroke;
FIG. 18 is a diagrammatic view showing the intake spool valve position at the end of the exhaust stroke;
FIG. 19 is a diagrammatic view showing the exhaust spool valve position at the start of the exhaust stroke;
FIG. 20 is a diagrammatic view showing the fully open exhaust spool valve position at 251 degrees of engine crankshaft angle;
FIG. 21 is a diagrammatic view showing the closing exhaust valve at the beginning of the intake stroke at 222 degrees of crankshaft angle;
FIG. 22 is a diagrammatic view showing the fully closed exhaust valve at the bottom of the intake stroke at 180 degrees of crankshaft angle;
FIG. 23 is a diagrammatic view showing the closed exhaust valve 90 degrees into the compression stroke;
FIG. 24 is a diagrammatic view showing the closed exhaust valve at zero degrees TDC;
FIG. 25 is a longitudinal diagrammatic view of the preferred secondary crankshaft that operates the intake and exhaust spool valves and moves them between positions illustrated in FIGS. 13-24 ;
FIGS. 26-28 are sectional views taken respectively along lines 26 - 26 , 27 - 27 , and 28 - 28 of FIG. 25 ;
FIG. 29 is an isometric view of a preferred spool valve sleeve, with portions broken away for clarity;
FIG. 30 is a bottom plan view of the sleeve of FIG. 29 ;
FIG. 31 is a side elevational view of the sleeve of FIG. 29 ;
FIG. 32 is an end elevational view of the sleeve of FIG. 29 ;
FIG. 33 is an enlarged, side elevational view of a preferred sealing ring used with the sliding valves;
FIG. 34 is an enlarged, plan view of a preferred sealing ring used with the sliding valves; and,
FIG. 35 is an enlarged, fragmentary plan view of circled region 35 in FIG. 33 .
DETAILED DESCRIPTION OF THE INVENTION
With initial reference directed to FIGS. 1-3 , 3 A, 4 , 4 A, and 5 of the appended drawings, a basic single-cylinder, four-cycle internal combustion engine equipped with the aspiration system constructed generally in accordance with the best mode of the invention has been generally designated by the reference numeral 10 . It should be understood that the aspiration system as herein described is suitable for use with engines equipped with multiple cylinders, arrayed in the popular V-configuration or other configurations. The engine 10 has a rigid block 11 housing a primary crankshaft 12 ( FIG. 3 ) of conventional construction that drives a reciprocating power piston 14 ( FIG. 3 ) with a conventional connecting rod 16 . The basic engine illustrated comprises a Honda thirteen-horsepower motor, which is modified as hereinafter described.
The standard combustion power piston 14 reciprocates within a cylinder 18 ( FIG. 3 ) that is externally air-cooled with multiple external heat dissipation fins 20 ( FIG. 1 ) proximate the engine deck 13 . The basic construction of the conventional piston 14 and its accessories is substantially conventional and is not critical to practice of the invention. The instant sliding valve system is disposed within a head, generally indicated by the reference numeral 22 (i.e., FIGS. 4 , 5 , 7 , 11 ), that mounts conventionally above the engine deck 13 above the conventional piston 14 and cylinder 18 described previously. The stroke of power piston 14 moves it upwardly and downwardly in a direction substantially perpendicular to head 11 . For purposes of this invention, the term “head” shall generally designate that region of an internal combustion engine enclosing the combustion chambers, above the pistons. Such a head may be a conventional separate part bolted atop the engine, or in some cases the “head” may be integral with the engine block in a single casting that is thereafter appropriately machined.
With additional reference directed primarily now to FIGS. 4-11 , head 22 houses a pair of tubular, sliding spool valves 24 , 25 ( FIGS. 8-10 ) that aspirate the cylinder 18 . Based upon experiments so far, the tubular exhaust valve 24 and the tubular intake valve 25 are made from titanium in the best mode. While those skilled in the art will recognize that several alloys of titanium and/or titanium steel are available, my experiments have yet to reveal the ideal composition of these critical valves. Ordinary steel compositions however, result in heat damage and premature wear and failure. Furthermore, as illustrated in FIG. 5 , for example, the sliding valves 24 , 25 are mounted in appropriately ported sleeves 27 that fit into the cylinder head and line up with the sliding valve ports and appropriate ports in the head. However, experiments with the engine as depicted with sleeveless valves have shown the design to be rugged and dependable so far.
A drive pulley 26 ( FIG. 1 ) driven by conventional internal crankshaft 12 ( FIG. 3 ) is connected via drive belt 28 to a valve pulley 30 that drives the slide valve crankshaft 32 housed within head 22 . Crankshaft 32 , best seen in FIG. 25 discussed hereinafter, is mounted perpendicularly relative to sliding valves 24 , 25 (i.e., FIGS. 7 , 11 ). It extends across and through compartmentalized crankshaft mounting region 34 ( FIG. 5 ) across the top (i.e., as viewed in FIGS. 4 , 5 ) of the head 22 . Region 34 contains liquid oil for lubricating the crankshaft and the slide valves to be described. Region 34 is normally covered by shroud 35 ( FIG. 3 ). The crankshaft exhaust journal 38 and the crankshaft intake valve journal 40 (i.e., FIG. 25 ) of crankshaft 32 support connecting rods 42 , 44 that respectively operate exhaust slide valve 24 , and intake slide valve 25 . Aligned and integral crankshaft portions 39 , 41 , 43 (i.e., FIG. 25 ) are rotatably constrained within conventional saddles 45 within mounting region 34 (i.e. FIG. 4 , 5 ) and mounted with conventional bearing assemblies 46 ( FIG. 2 ) as known in the art. In the best mode it is proposed that the counterweight sections 109 , 110 , 111 , and 112 of the crankshaft ( FIG. 25 ) be drilled appropriately for crankshaft balancing. Preferably the rotating and reciprocating aspiration slide valve assembly may thus be “balanced” and “tuned” for optimal aspiration performance.
The crankshaft bearing assemblies 46 are bolted within crankshaft region 34 to mount the slide valve crankshaft 32 over the saddles 45 are secured with a plurality of bolts 48 . As best seen in FIGS. 4 , 5 and 7 , head 22 includes a plurality of spaced apart mounting orifices 50 through which head bolts 52 ( FIG. 11 ) extend when mounting the head 22 to the deck 13 .
The intake spool valve 25 (i.e., FIG. 11 ) is slidably received within a sleeve 27 B disposed within head tunnel 55 ( FIGS. 4 , 11 ), that is spaced apart from and parallel with exhaust tunnel 54 and sleeve 27 . Tunnels 54 and 55 are oriented generally perpendicularly to the stroke of the power piston 14 . Exhaust spool valve 24 slidably reciprocates within sleeve 27 concentrically disposed within tunnel 54 . Sleeves 27 , 27 B ( FIGS. 5 , 29 - 32 ) require ports aligned with head ports and valve described hereinafter, as appreciated by those skilled in the art. An air-fuel mixture is drawn into intake valve tunnel 55 from a conventional carburetor 29 ( FIG. 2 ) mounted with screws received within orifices 59 ( FIG. 4 ). Alternatively the invention may be used with fuel injection systems.
As best viewed in FIGS. 29-32 , each sleeve 27 is elongated and tubular. Each has a pair of spaced apart open ends 31 defining opposite ends of an elongated cylindrical passageway in which the sliding valves 24 and/or 25 are inserted. A pair of ports 68 A are separated by a bridge 69 A ( FIG. 29 ) that maintains pressure on the sliding valve rings during operation. While both sleeves are identical in dimensions and geometry, the exhaust sleeve should be of a more expensive heat resistant alloy. It is preferred that the exhaust sleeve be made of Steelite or Nickalloy heat resistant titanium steel alloy.
This invention requires maximal air flow quickly. In other words, it is preferred that the carburetor 29 have a relatively large throat with a relatively short venturi. In the model depicted in the drawings, which has been thoroughly tested, a Honda 350 cc. “dirt bike” motorcycle carburetor is preferred.
Exhaust valve 24 is slidably constrained within its sleeve 27 in tubular tunnel 54 ( FIGS. 5 , 7 , 11 ). The exhaust header 57 ( FIG. 1 ) is preferably screw-mounted upon the head's end surface 58 ( FIGS. 4 , 7 ) with suitable screws that penetrate orifices 60 . Head cooling is encouraged by fin areas 36 ( FIG. 5 ).
As best seen in FIG. 7 , the circular combustion chamber 62 includes a central, threaded spark plug passageway 64 that is spaced between intake ports, collectively numbered 66 , and exhaust ports, collectively numbered 68 ( FIG. 7 ). A conventional spark plug 70 (i.e., FIGS. 1 , 11 ) is threadably mated to passageway 64 , with its electrodes positioned and centered within combustion chamber 62 .
As seen in FIGS. 29-30 , for example, adjacent sleeve ports 68 A are separated from one another by a central bridge 69 A. Similarly intake ports 66 in the head ( FIG. 7 ) built into the combustion chamber may be separated with a bridge 67 that is integral with the head 22 . Similarly, a rigid, centered bridge 69 in the head separates the twin exhaust ports 68 ( FIGS. 6 , 7 ). These ports in the head must align with the valve sleeve ports 68 A seen in FIGS. 29-32 .
As best seen in FIG. 6 , each head exhaust port 68 aligns with sleeve port 68 A. The composite ports have smooth, downwardly inclined sidewalls 74 , 75 that are polished for maximal fluid flow. These walls communicate with a lower orifice 73 in the head that opens to the combustion chamber 62 . The intake ports 66 (i.e., FIG. 7 ) are similarly configured. Importantly, it is desired that corner ridges of the structure be radiused for maximum fluid flow, as illustrated by gently radiused corner regions
Importantly, rigid, transverse bridges 69 A are integrally formed in the sleeve port regions and bisect these regions into twin, side by side orifices 68 A ( FIG. 29 ). The head is similarly ported. In FIG. 7 , for example, there are two pairs of ports 66 and 68 respectively separated by bridges 67 , 69 . Sleeve 69 A bear against critical sealing rings associated with the sliding valves 24 and 25 , as discussed below. By pressuring the sealing rings during valve travel, deformation of the critical sealing rings in the region of the various exhaust ports 68 and intake ports 66 is prevented. As sealing of the tubular slide valves 24 , 25 is critical to the invention, bridges 67 and 69 are vital to the best mode of the invention.
With joint reference directed now primarily to FIGS. 8-12 and 10 A, valves 24 and 25 are structurally virtually identical, so only exhaust valve 24 will be detailed. However, it is thought that the exhaust valve 24 requires a more heat resistance, so a premium grade of titanium alloy steel is preferred.
Each valve 24 , 25 is elongated, substantially tubular, and multi-sectioned. An open connecting rod section 80 enables connection to the connecting rod 42 ( FIG. 12 ). The rod end 42 extends into the interior 82 of section 80 and is journalled by wrist pin 85 ( FIG. 3 ) and is conventionally secured between wrist pin orifices 84 ( FIGS. 9 , 10 A). Importantly, section 80 ends in a closed interior wall 87 that separates region 82 and the connecting rod structure from the rest of the tubular interior 89 ( FIG. 10A ) of the valve 24 . The open end of the interior passageway 89 within each valve directly communicates through tubular tunnels 54 , or 55 ( FIG. 4 ) for aspiration fluid flow. The exterior of valve rod section 80 ( FIGS. 9 , 10 A) is preferably cross hatched by machining to promote oil flow and distribution.
In the best mode each valve has three pairs of external ring grooves to seat suitable sealing rings. For example, a pair of concentric and parallel ring grooves 91 separate valve rod section 80 from port section 94 ( FIG. 9 ). Ring grooves 92 separate port section 94 from adjacent midsection 96 . Similarly, ring grooves 93 separate midsection 96 from open section 98 . FIG. 8 shows that each pair of ring grooves 91 , 92 and/or 93 seats pairs of spaced apart, concentric sealing rings 100 A, 100 B and 100 C respectively, that are externally, coaxially mounted about the valve exterior. Since each valve rod section 80 is in fluid flow communication with head region 34 that contains lubricating oil, rings 100 A are oil rings. It will be recognized by those skilled in the art that when the valves 24 or 25 are fitted within their sleeves 27 , (i.e., FIG. 4 ) the rings 100 A, 100 B, or 100 C will seat within ring grooves 91 , 92 or 93 (i.e., FIG. 9 ) and the exterior of the rings will be flush with the cylindrical outside body of the valves 24 , 25 , touching the interior surfaces of the captivating sleeves 27 .
Each sealing ring 100 A, 100 B, 100 C is preferably made of heat treated and heat resistant nickel alloy steel. As best seen in FIGS. 33-35 , the compressively touching ends of the rings are stepped in the best mode to form an overlapped intersection 113 that forms an improved pressure seal. Preferably, each end of a given ring is configured in the overlapping or stepped configuration of FIG. 35 , where abutting ring ends comprise a notched region 115 and a bordering, elongated tabbed region 116 . The tabbed regions 116 are variably spaced apart from notched regions 115 , with end gaps 117 therebetween. The parallel, spaced apart ring end gaps 117 allow for thermal expansion and contraction of the rings during operation. However, a sealing gap 118 , which is perpendicular to gaps 117 , is defined between mutually aligned and abutting tabbed regions 116 . Gap 118 is much smaller than indicated, and provides a seal, as end regions 116 abut in operation, and seal the gaps for compression. At the same time gaps 117 allow for normal thermal expansion and contraction.
Importantly, the valve port section 94 ( FIGS. 8 , 9 ) includes an enlarged, arcuate cutout 102 functioning as an aspiration port (i.e., either exhaust or intake). Port 102 radially extends about approximately 30-40 percent of the radial periphery of the valve. A gently radiused arch 103 above port 102 ( FIGS. 8 , 10 A) leads to the smoothly configured, generally cylindrical passageway 89 that leads to the exterior of the valve. Passageway 89 ( FIG. 10A ) comprises tubular interior passageway walls 104 , terminating in gently radiused, flared lips 106 ( FIG. 10A ) at the valve end that maximize fluid flow. Aspiration occurs when valve ports 102 are aligned with sleeve ports 68 A ( FIG. 32 ) which are in turn aligned with head port pairs 66 or 68 ( FIG. 7 ), in response to timed, reciprocal movements caused by the valve crankshaft 32 previously described. Thus when port 102 ( FIGS. 3 , 9 ) of the exhaust valve 24 overlies sleeve ports 68 A ( FIG. 32 ) and head ports 68 ( FIG. 7 ), hot exhaust gases may be vented away from the combustion chamber 62 and lower cylinder 18 in response to upward movement of the power piston 14 towards top-dead-center. At this time exhaust gases are vented to the left (as viewed in FIG. 9 ) through port 102 , along the valve interior passageway 89 ( FIG. 8 ) and through head tunnel 54 ( FIG. 7 ) and out header 57 ( FIGS. 1 , 3 ). Similarly, during the intake stroke, air and raw fuel is drawn through carburetor 29 into the head 22 through tunnel 55 ( FIG. 7 ), and into the chamber 89 in the intake valve 25 , through its port 102 and into the cylinder combustion region through head ports 66 ( FIG. 7 ) and aligned sleeve ports 68 A.
Importantly, as slide valves 24 , 25 reciprocate, their multiple sealing rings 100 are prevented from deformation while traversing sleeve ports 68 A by the bridges 69 A (i.e., FIG. 32 ). Further valve deformation is prevented by the downsized diameter of valve midsections 96 (i.e., FIG. 8 ). Referencing FIG. 9 , the arrow 105 indicates the outside diameter of the majority of the length of valve 24 . Sections 80 , 94 , and 98 are all of this relatively larger diameter. Valve midsection 96 however, has a reduced diameter indicated by the arrow 107 ( FIG. 9 ). When the valves 24 , 25 are positioned to “block” the various ports, midsection 96 is positioned over them. Thus a cylindrical or annular region 101 ( FIGS. 3 , 3 A, 4 and 4 A) defined radially around the external periphery of valve midsection 96 between the surrounding tunnels 54 or 55 , and axially defined between the rings 100 on opposite ends of valve midsection 96 , will be in fluid flow communication with the combustion chamber 62 . Annulus 101 thus distributes potential shearing pressure about the circumference of the valve when the ports are blocked during various valve stroke positions to reduce damage. During the power stroke, for example, the shock from rising gas pressure will be uniformly distributed about the radial periphery of valve midsection 96 within annulus 101 , equalizing forces that might otherwise deform the valve.
OPERATION
In FIG. 13 intake valve 25 has started to open at the beginning of the intake stroke. In FIG. 14 the intake valve 25 is now open at approximately 108 degrees BTDC.
FIG. 15 shows the intake valve 25 closing at the end of the intake stroke. Full closure of valve 25 is indicated in FIG. 16 at the beginning of the power stroke.
FIG. 17 shows the bottom of the power stroke, with the intake valve 25 fully closed. In FIG. 18 at the end of the exhaust stroke the intake valve 25 is seen starting to open.
The exhaust valve 24 is seen in FIG. 19 at the start of the exhaust stroke. In FIG. 19 , the plug and cylinder have fired, and at 108 degrees ATDC the exhaust valve 24 starts to open. In FIG. 20 the exhaust valve 24 is completely open, with 251 degrees crankshaft angle.
At the beginning of the intake stroke in FIG. 21 the exhaust valve 24 begins to close, at approximately 222 degrees. The bottom of the intake stroke is seen in FIG. 22 , at which time the exhaust valve 24 is fully “closed,” and the reduced diameter midsection 96 is positioned over the exhaust ports 68 .
In FIG. 23 the exhaust valve 24 is completely open, 90 degrees into the compression stroke. In the positions of FIG. 24 the plug fires, and the exhaust valve 24 is completely closed at zero degrees TDC.
In FIGS. 25-28 the configuration and position of the crankshaft 32 is illustrated. The exhaust valve journal 40 and the intake journal 38 are seen in critical rotational positions.
EXAMPLE
Dyno Test Chart—December, 2008
FACTORY
LOW LOAD
ENGINE
G1 ENGINE
Load %
33%
33%
RPM
2900
2900
Run Time
1:30 minutes
1:30 minutes
lb-ft Torque
7.5
7.5
Brake Horsepower
4.1
4.1
Fuel Usage - Milliliters
12.07
10.86
Nitrogen Oxide—NOX
10.97
10.97
Carbon Monoxide—CO
0.95
1.07
Hydrocarbons—HC
21.9
2.39
Carbon Dioxide—CO2
2.1
2
Oxygen—O2
1.41
1.43
G1 Fuel Usage Results Per Unit of Brake Horsepower
Low Load Fuel Usage: 10% Less than Factory Engine (12.07−10.86=1.21/12.07)
FACTORY
HIGH LOAD
ENGINE
G1 ENGINE
Load %
80%
80%
RPM
3550
3550
Run Time
1:30 minutes
1:30 minutes
lb-ft Torque
10
14
Brake Horsepower
6.7
9.4
Fuel Usage - Milliliters
13.19
8.65
Nitrogen Oxide—NOX
5.97
4.57
Carbon Monoxide—CO
0.58
0.44
Hydrocarbons—HC
11.04
1.07
Carbon Dioxide—CO2
1.29
0.8
Oxygen—O2
1.34
0.67
G1 Fuel Usage Results Per Unit of Brake Horsepower
High Load Fuel Usage: 34.4% Less than Factory Engine (13.19−8.65=4.54/13.19)
G1 High Load Emission Results Per Unit of Brake Horsepower
NOX: 23.4% Less than Factory Engine HC: 90.3% Less than Factory Engine
CO: 24.1% Less than Factory Engine CO2: 37.9% Less than Factory Engine
Two GX 390 Honda 13 hp engines were used for testing and comparisons (i.e., a “stock” engine versus one modified in accordance with the instant invention). Both engine specifications were as follows:
Four stroke valve single cylinder 3.5×2.5 bore & stroke 4.412 rod length Forced air cooling systems Gravity feed fuel systems 87 octane gasoline 23.7 cu/in displacement Transistorized magnet ignition systems
The muffler was removed on both engines to confine exhaust emissions for analysis purposes. The engine with the stock head is named the “Factory” engine on the above chart. The engine with our proprietary head is named the “G1” on the above chart.
All tests were conducted on the same day in a controlled and isolated environment. Fuel and emission measurements were made using the following equipment:
Land & Sea Water Brake Dyno, the Dyno-Max 2000 Model Dyno-Max 2000 Data Analysis Software and Multimedia PC Demonstration, 9.38 SPI Version UEI AGA 5000 Emissions Analyzer ASTME rated ⅜ inch Bellwether 100 cc Tube
The primary objective of house testing was to determine the fuel usage of the modified engine. We kept run time, load and rpm constant. To compare and measure the efficiency, input was divided by output. In our particular case, fuel usage was our input variable and our output variable was the pound-foot of torque produced. Fuel usage and all emissions results of both engines were calculated based on a unit of brake horsepower (torque×rpm/5252).
The low load fuel usage per unit of brake horsepower for the G1 engine was 10% less than the Factory engine. The high load fuel usage per unit of brake horsepower for the G1 engine above. It was determined that fuel consumption of the modified engine G1 was 34.4% less than the Factory engine. The high load emissions per unit of brake horsepower for the G1 engine resulted in 23.4% less nitrogen oxide (NOX),
24.1% less carbon monoxide (CO), 90.3% less hydrocarbons (HC) and 37.9% less carbon dioxide (CO2) compared to the Factory engine.
From the foregoing, it will be seen that this invention is one well adapted to obtain all the ends and objects herein set forth, together with other advantages which are inherent to the structure.
It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations.
As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense. | An internal combustion engine uses separate, tubular and hollow reciprocating sleeve valves that open and close intake and exhaust passageways for improved aspiration. The sliding sleeve valves are disposed within sleeves horizontally disposed within a modified head secured above the combustion chamber. The valves are driven in a path normal to the engine pistons by an independent crankshaft that is rotated through an external pulley driven by the engine crankshaft. Fluid flow occurs through the valve interior and through ports dynamically positioned above the compression cylinder, proximate aligned sleeve and head ports. Sleeve ports are separated by bridges that maintain valve rings in compression during reciprocation to prevent damage. Each valve body has a reduced diameter midsection forming a relief annulus that distributes shearing pressures about the circumference of the valve. High pressure gas is confined between axially spaced apart, stepped sealing rings that prevent gases from flowing axially about the valve exterior. | 5 |
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention related to an evaporated gas supply method in which an evaporated gas having a primary pressure filled in a cylinder is reduced in pressure to a secondary pressure through adiabatic expansion, and the evaporated gas having the secondary pressure is supplied to a predetermined consuming installation.
2. Prior Art
For the purpose of realizing a long-term supply of an evaporated gas in a case where the evaporated gas is supplied to a semiconductor manufacturing factory, such a conventional evaporated gas supply system has been used that the said evaporated gas is filled at a high-pressure condition (for example, 52 kg/cm 2 .abs) in a cabinet cylinder, and it will be supplied after its pressure is reduced by an expansion valve.
Referring to FIG. 10 and FIG. 11, the evaporated gas supply system of the prior art will be described. FIG. 10 is a view showing the outline of a conventional evaporation and supply apparatus and FIG. 11 is a graph showing a change of pressure in an expansion valve.
In a cabinet cylinder 1, an evaporated gas 2 is filled at a high-pressure (primary pressure) condition. A pipe 4 is laid from this cabinet cylinder 1 to a consuming installation 3 such as a semiconductor manufacturing factory, and an expansion valve 5 is attached on the way thereof. By means of this expansion valve 5, the evaporated gas 2 in the cabinet cylinder 1 is reduced in pressure so as to provide the evaporated gas 2 having a low pressure (secondary pressure) usable in the consuming installation 3.
According to the evaporated gas supply method of the prior art, the evaporated gas 2 is being preserved in the cabinet cylinder 1 for a long period of time, and therefore, the evaporated gas 2 to be supplied gets in a saturated state or a state near thereto. If the evaporated gas 2 is supplied from such state by way of the expansion valve 5, a liquid seal will be caused to take place. For instance, in a case where 100% N 2 O having a primary pressure of 50 kg/cm 2 is led to the expansion valve 5 so that its pressure is reduced to a secondary pressure of 5 kg/cm 2 , it will become N 2 O comprising 97% of gas and 3% of liquid. As a result, a liquid seal takes place, resulting in such a problem that the same evaporated gas 2 can not be supplied at a predetermined flow rate to the concuming installation 3.
It is an object of the presnt invention to provide an evaporated gas supply method in which the liquid seal of an evaporated gas can be prevented from taking place.
SUMMARY OF THE INVENTION
In order to achieve the aforementioned purpose, according to the present invention, there is provided an evaporated gas supply method in which an evaporated gas having a primary pressure filled in a cylinder is reduced in pressure to a secondary pressure through adiabatic expansion, and the evaporated gas having the secondary pressure is supplied to a predetermined consuming installation, and which comprises: a step of cooling down the evaporated gas in the cylinder, whereby the enthalpy of the evaporated gas filled in said cylinder is increased over an enthalpy of the secondary pressure on the saturated vapor line in a pressure-enthalpy diagram of the same evaporated gas; and a step of adiabatically expanding the evaporated gas filled in the cylinder so that its pressure is reduced, and supplying the evaporated gas having the reduced pressure to said consuming installation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view showing the evaporated gas supply system according to one preferred embodiment of the present invention.
FIG. 2 is a view showing a change of state when N 2 O filled in a cabinet cylinder 1 whose internal temperature is 40° C. is reduced in pressure from P1=82 kg/cm 2 .abs (Point A) to P2=4 kg/cm 2 .abs (Point B) by an expansion valve 5.
FIG. 3 is a view showing a change of state when N 2 O filled in a cabinet cylinder 1 whose internal temperature is 36.5° C., the critical temperature of N 2 O, is reduced in pressure from P1=74 kg/cm 2 .abs (Point A) to P2=4 kg/cm 2 .abs (Point B) by an expansion valve 5.
FIG. 4 is a view showing a change of state when N 2 O filled in a cabinet cylinder 1 whose internal temperature is 30° C. is reduced in pressure from P1=64 kg/cm 2 .abs (Point A) to P2=4 kg/cm 2 .abs (point B) by an expansion valve 5.
FIG. 5 is a view showing a change of state when N 2 O filled in a cabinet cylinder 1 whose internal temperature is 20° C. is reduced in pressure from P1=52 kg/cm 2 .abs (Point A) to P2=4 kg/cm 2 .abs (Point B) by an expansion valve 5.
FIG. 6 is a view showing a change of state when N 2 O filled in a cabinet cylinder 1 whose internal temperature is 10° C. is reduced in pressure from P1=43 kg/cm 2 .abs (Point A) to P2=4 kg/cm 2 .abs (Point B) by an expansion valve 5.
FIG. 7 is a view showing a change of state when N 2 O filled in a cabinet cylinder 1 whose internal temperature is 0° C. is reduced in pressure from P1=34 kg/cm 2 .abs (Point A) to P2=4 kg/cm 2 .abs (Point B) by an expansion valve 5.
FIG. 8 is a view showing a change of state when N 2 O filled in a cabinet cylinder 1 whose internal temperature is -10° C. is reduced in pressure from P1=25 kg/cm 2 .abs (Point A) to P2=4 kg/cm 2 .abs (Point B) by an expansion valve 5.
FIG. 9 is a view showing a change of state when N 2 O filled in a cabinet cylinder 1 whose internal pressure is 30° C. is reduced in pressure from an initial pressure P1=64 kg/cm 2 .abs (Point A) to a medium pressure PC=10 kg/cm 2 .abs (Point B) and a supply pressure P2=4 kg/cm 2 .abs (Point C) by two expansion valves 5.
FIG. 10 is a view showing the outline of the evaporation and supply apparatus of the prior art.
FIG. 11 is a view showing the change of pressure in the expansion valve.
DESCRIPTION OF REFERENCE NUMERALS
1--cabinet cylinder, 2--evaporated gas, 3--consuming installation, 4--pipe, 5--expansion valve, 10--cooling means, 11--state change monitoring means.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Since the present invention is constructed as mentioned above, an evaporated gas filled in a cylinder is cooled down before it is adiabatically expanded so that its enthalpy becomes at least an enthalpy at the secondary pressure on the saturated vapor line. If this evaporated gas is adiabatically expanded, its pressure will be reduced to a secondary pressure, but no liquefaction is caused to take place at the secondary pressure for supply to the consuming installation because the adiabatically expanded evaporated gas has already obtained the enthalpy at the secondary pressure on the saturated vapor line. Thus, its liquid seal can be prevented from taking place.
EMBODIMENT
Referring to the accompanying drawings, the evaporated gas supply method according to one preferred embodiment of the present invention will be described. The same reference numerals are used for the same elements and the duplicate explanations will be omitted.
The principle of the present invention will be first described in accordance with FIGS. 2 to 8. Each of FIGS. 2 to 8 is a pressure-enthalpy diagram of N 2 O showing a change of state where its pressure is reduced from a primary pressure P1 to a secondary pressure P2=4 kg/cm 2 .abs. As to the primary pressures P1, FIG. 2 shows P1=82 kg/cm 2 .abs, FIG. 3: P1=74 kg/cm 2 .abs, FIG. 4: P1=64 kg/cm 2 .abs, FIG. 5: P1=52 kg/cm 2 .abs, FIG. 6: P1.=43 kg/cm 2 .abs, FIG. 7: P1=34 kg/cm 2 .abs and FIG. 8: P1=25 kg/cm 2 .abs, respectively.
In FIG. 2, a change of state is shown when N 2 O filled in a cabinet cylinder 1 whose internal temperature is 40° C. is reduced in pressure from P1=82 kg/cm 2 .abs (Point A) to P2=4 kg/cm 2 .abs (Point B) by an expansion valve 5. In this case, the temperature of N 2 O caused by its adiabatic expansion in the pressure reduction is lowered to about -63° C. and about 18% of the gas is liquefied.
FIG. 3 shows a change of state when N 2 O filled in a cabinet cylinder 1 whose internal temperature is 36.5° C., this is the critical temperature of N 2 O, is reduced in pressure from P1=74 kg/cm 2 .abs (Point A) to P2=4 kg/cm 2 .abs (Point B) by an expansion valve 5. In this case, the temperature of N 2 O caused by its adiabatic expansion in the pressure reduction is lowered to about -63° C. and about 22% of the gas is liquefied.
FIG. 4 shows a change of state when N 2 O filled in a cabinet cylinder 1 whose internal temperature is 30° C. is reduced in pressure from P1=64 kg/cm 2 .abs (Point A) to P2=4 kg/cm 2 .abs (Point B) by an expansion valve 5. In this case, the temperature of N 2 O caused by its adiabatic expansion in the pressure reduction is lowered to about -63° C. and about 10% of the gas is liquefied.
In FIG. 5, a change of state is shown when N 2 O filled in a cabinet cylinder 1 whose internal temperature is 20° C. is reduced in pressure from P1=52 kg/cm 2 .abs (Point A) to P2=4 kg/cm 2 .abs (Point B) by an expansion valve 5. In this case, the temperature of N 2 O caused by its adiabatic expansion in the pressure reduction is lowered to about -63° C. and about 3% of the gas is liquefied.
FIG. 6 shows a change of state when N 2 O filled in a cabinet cylinder 1 whose internal temperature is 10° C. is reduced in pressure from P1=43 kg/cm 2 .abs (Point A) to P2=4 kg/cm 2 .abs (Point B) by an expansion valve 5. In this case, the temperature of N 2 O caused by its adiabatic expansion in the pressure reduction is lowered to about -63° C., but the gas is not liquefied even by the adiabatic expansion because Point B is on the saturated vapor line (a critical line of saturation). For facilitating the explanation, in addition, the enthalpy on the critical line of saturation at P2=4 kg/cm 2 .abs will be hereinafter defined as "the saturation critical enthalpy (=h 2SC )".
FIG. 7 shows a change of state when N 2 O filled in a cabinet cylinder 1 whose internal temperature is 0° C. is reduced in pressure from P1=34 kg/cm 2 .abs (Point A) to P2=4 kg/cm 2 .abs (Point B) by an expansion valve 5. In this case, the temperature of N 2 O caused by its adiabatic expansion in the pressure reduction is lowered to about -60° C., but the gas is not liquefied even by the adiabatic expansion because Point B is right of the critical line of saturation, namely it is in a state of superheated vapor.
In FIG. 8, furthermore, a change of state is shown when N 2 O filled in a cabinet cylinder 1 whose internal tempeature is -10° C. is reduced in pressure from P1=25 kg/cm 2 .abs (Point A) to P2=4 kg/cm 2 .abs (Point B) by an expansion valve 5. In this case, the temperature of N 2 O caused by its adiabatic expansion in the pressure reduction is lowered to about -57 C., but no liquefaction of the gas is absolutly caused to take place in the expansion valve 5 bacause both the adiabatic expansion course and Point B are right of the critical line of saturation. In addition, P1=25 kg/cm.abs exhibits the maximum enthalpy on the critical line of saturation, and for facilitating the explanation, this pressure will be hereinafter defined as the maximum enthalpy pressure (=P hmax ).
From these inventor's data obtained as mentioned above, the inventor has discovered:
1 If the sate of the evaporated gas 2 fed from the cabinet cylinder 1 to the expansion valve 5 is kept in anyone of the states shown in FIG. 6, FIG. 7 and FIG. 8, the liquefaction of the evaporated gas 2 in the expansion valve 5 can be prevented from taking place; and
2 In order that the state of the evaporated gas 2 is transferred from the state shown in FIG. 2, FIG. 3, FIG. 4 or FIG. 5 to the state shown in FIG. 6, FIG. 7 or FIG. 8, this transfer can be satisfctorily carried out by cooling down the evaporated gas 2.
The discovery 1 is based on the adiabatic expansion courses shown in FIGS. 2 to 8 and the discovery 2 is based on the positional relations of the isotherms depicted in FIGS. 2 to 8.
Referring to FIG. 1, in the next place, the evaporated gas supply system which the inventor has invented will be described.
FIG. 1 is a schematic view showing the evaporated gas supply system according to one preferred embodiment of the present invention. The differences between the evaporated gas supply system according to the present invention and that of the prior art are the addition of a cooling means 10 to the cabinet cylinder 1 and the provision of a state change monitoring means which can detect a physical quantity (such as pressure or temperature) capable of specifying the state of the evaporated gas filled in the cabinet cylinder 1.
In the cabinet cylinder 1, an evaporated gas 2 is filled in a high-pressure (primary pressure) condition, as mentioned above. So, a portion of the evaporated gas 2 gets liquefied. From this cabinet cylinder 1, a pipe 4 is laid to a consuming installation 3, for instance a semiconductor manufacturing factory, and an expansion valve 5 is attached on the way of said pipe 4. The pipe 4 is covered with a heat insulating material for insulation of heat from the out side. By means of this expansion valve 5, the evaporated gas 2 in the cabinet cylinder 1 is reduced in pressure so as to provide the evaporated gas 2 having a low pressure (secondary pressure) usable in the consuming installation 3. The cabinet cylinder 1 has the cooling means 10 and the state change monitoring means 11 installed thereto.
An air cooling system of blowing air into the cabinet cylinder 1 or a liquid cooling system of cooling the outer periphery of the cabinet cylinder 1 with a liquid is applicable as the cooling means 10. And, a thermometer, pressure gage, hygrometer or thermostat is usable as the state change monitoring means 11.
The evaporated gas supply method according to the present invention is effective in a case where (a) the primary pressure of an evaporated gas when filled in a cabinet cylinder 1 exceeds P hmax and (b) the enthalpy thereof at the primary pressure when filled in a cabinet cylinder 1 is less than h 2SC , (namely, in a case where an evaporated gas having a primary pressure is adiabatically expanded as it is and as a result, its liquefaction is caused to take place).
At first, accordingly, it must be done to judge whether the state of the evaporated gas 2 in the cabinet cylinder 1 satisfies the above conditions (a) and (b). In a case where these conditions are satisfied, the cabinet cylinder 1 is cooled down by the cooling means 10 because the evaporated gas will be liquefied, if it is adiabatically expanded as it is. By this cooling of the cabinet cylinder 1, the evaporated gas 2 having the primary pressure goes down along the saturated vapor line. At that time, the change of state of the evaporated gas 2 caused by the cooling means 10 is alwys monitored by means of the state change monitoring means 11, and the detection of this state will be continued until its enthalpy reaches h 2SC . As to the detecting method, it may be satisfactorily carried out to detect the enthalpy of the evaporated gas 2 directly or to detect its pressure or temperatue that exhibits indirectly the state of enthalpy. After the enthalpy of the evaporated gas 2 has reached the desired state, the evaporated gas 2 in the cylinder cabinet 1 is fed to the expansion valve 5, where its pressure is reduced for derivery to the consuming installation 3.
Owing to the abovementioned construction, the present invention can reliably prevent the liquefaction of an evaporated gas in an expansion valve from taking place. In particular, in a case where a device (such as a regulator) which undergoes any bad influence by an evaporated gas containing several percent of liquid is placed downstream of the expansion valve, the present invention is more effective.
In the abovementioned embodiment, a case where the evaporated gas is adiabatically expanded in one stage has been described as one example. However, the present invention is also applicable to a case where the adiabatic expansion of an evaporated gas is carried out in plural stages. In this case, an evaporated gas must be cooled down so that the enthalpy of the evaporated gas before a final adiabatic expansion is carried out reaches h 2SC .
For instance, in a case where when an evaporated gas is adiabatically expanded in two stages, the enthalpy is evitably increased by Δh=5 (kcal/kg) between the first-stage adiabatic expansion and second-stage adiabatic expansion under the condition of 2SC =155 (kcal/kg) and h 1 =148 (kcal/kg), the aimed enthalpy should be 150 (kcal/kg) that is obtained by subtracting Δh from h 2SC . Therefore, the cabinet cylinder will be statisfactorily cooled down so that the state of the evaporated gas before it is adiabatically expanded becomes at least 150 (kcal/kg).
FIG. 9 shows a change of state when N 2 O filled in a cabinet cylinder 1 whose internal temperature is 30° C. is reduced in pressure from an intitial pressure P1=64 kg/cm 2 .abs (Point A) to a supply pressure P2=4 kg/cm 2 .abs (Point C) by two expansion valves 5. The evaporated gas is cooled down so that its first enthalpy h 1 becomes over (h 2SC -Δh), as mentioned above. Then, the evaporated gas 2 is reduced in pressure to a medium pressure PC=10 kg/cm 2 .abs by the first expansion valve so that its enthalpy value is increased by Δh until it is fed to the final expansion valve, and it is further reduced in pressure to a supply pressure P2=4 kg/cm.abs by the final expansion valve. Although the temperature of the evaporated gas is lowered to about -55° C. due to its adiabatic expansion in the final pressure reduction, no liquefaction of the gas is caused to take place even by the adiabatic expansion because Point C is right of the saturated vapor line, i.e. positioned in the reagion of superheated vapor.
In addition, the present invention is not limited to the above embodiment and various modifications can be made to the present invention. Although an expansion valve is used as the device which makes an adiabatic expansion of gas in this preferred embodiment, another means can be used, not limited to the expansion valve, if it has a function of making the adiabatic expansion of gas.
Although this preferred embodiment has been desribed as one example of N 2 O, the present invention is also applicable to an evaporated gas (such as HCl) in which the critical temperature is near to room temperature, the vapor pressure at room temperature is higher and the flow rate is larger.
EFFECTS OF THE INVENTION
The present invention is constructed as desribed above, and therefore, it is possible to effectively prevent the liquid seal of an evaporated gas from taking place. | An evaporated gas supply method in which the liquid seal of an evaporated gas can be effectively avoided, is provided. According to the present invention, there is provided an evaporated gas supply method in which an evaporated gas having a primary pressure filled in a cylinder is reduced in pressure to a secondary pressure through adiabatic expansion, and the evaporated gas having the secondary pressure is supplied to a predetermined consuming installation, and which comprises a step of cooling down an evaporated gas in a cylinder, whereby the enthalpy of the evaporated gas (2) filled in the said cylinder is increased over an enthalpy of the secondary pressure on the saturated vapor line in a pressure-enthalpy diagram of the same evaporated gas, and a step of adiabatically expanding the evaporated gas filled in the cylinder so that its pressure is reduced, and supplying the evaporated gas having the reduced pressure to said consuming installation. | 5 |
BACKGROUND OF THE INVENTION
Prior proposals have been made to use catalysts in smoking articles where the catalyst is mixed with a carbonaceous material to form a combustible fuel element (U.S. Pat. No. 5,211,684). It has also been proposed to use an aerosol precursor of ceramic material for forming an aerosol in a smoking article (U.S. Pat. No. 5,115,820). The coating of a fuel in a smoker's cigarette with ceria also have been proposed (U.S. Pat. No. 5,040,551).
SUMMARY OF THE INVENTION
Broadly, the present invention comprises a cigarette and its method of construction and a operation including a heat source, a flavorant aerosol portion and a mouthpiece in which the heat source includes a liquid fuel and air mixing chamber and a catalyst burning chamber in which the fuel air mixture combusts under the influence of the catalyst.
The invention includes the method of controlling the products of combustion including the amounts of carbon monoxide produced. Such control is found in the construction and operation of the catalyst substrate arrangement including a supporting matrix and coatings thereon which may include one or more of an alumina coating, a cerium oxide coating and finally a platinum/palladium chloride coating. The oxide and nobel metal coatings are catalytic.
The cigarette of the present invention includes a fuel/air mixing section which contains a liquid absorbent reservoir having liquid fuel therein. Air is moved through the reservoir to pick up fuel particles forming a mixture for delivery to the catalytic combustion chamber. The combustion products are drawn through the flavorant portion including a glycerin to generate a glycerin-based aerosol. The flavored aerosol is then delivered to the mouthpiece of the smoker.
The cigarette of the present invention has the dimensions of and the general appearance of conventional cigarettes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of the smoking article of the present invention;
FIG. 1a is a sectional view along line 1a--1a of FIG. 1;
FIG. 2 is the same view as FIG. 1 showing in addition the air, fuel/air mixture and aerosol flow patterns during smoking; and
FIGS. 3a-d are perspective views of honeycombs used in the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the Figures, cigarette or smoking article 10 includes filter mouthpiece section 11, flavorant section 12, aerosol section 13, a fuel storage and air mixing section 16 and a catalytic combustion section 17. Cigarette 10 is defined by outer cylindrical paper wrap 10r which may be a single piece of wrap or be composed of attached or overlapping sections. Additional wrappers and tipping paper may be used.
Mouthpiece section 11 is a filter for filtering the gases of cigarette 10 and may be a conventional cigarette filter. Flavorant section 12 is principally cut tobacco 12a including top dressing or other materials and flavors to enhance the taste of the gases reaching the smoker's mouth. Preferably, cut tobacco 12a fills the space between mouthpiece section 11 and aerosol support material 19.
Aerosol section 13 includes an aerosol support plug 19 with glycerin on it. Alternative to glycerin, polyhydric alcohols such as propylene glycol may be used. Aerosol supporting materials may include carbon mat, magnesium oxide, alumina, glass beads, vermiculite, carbon, aluminum foil and paper coated with hydrolyzed organosiloxanes. The aerosol former can also be added/incorporated into the cut tobacco or a reconstituted tobacco type material. When hot gases of combustion including water vapor water, CO 2 and CO are caused to flow through plug 19 a glycerin aerosol is formed.
Fuel storage and air mixing section 16 includes circumferential side ventilation holes 21 through which outside air enters, see A1-A6 in FIG. 2, cigarette 10 as it is smoked as will be further explained. Section 16 includes fuel absorbent reservoir 22 including a wick material for storing liquid fuel in amounts ranging from about 300-500 microliters (μl). The absorbent fuel reservoir consists of a synthetic fiber liquid transfer wick material which utilizes capillary action. Preferably, Transorb brand wicks are used in the practice of this invention. Reservoir 22 may include any suitable material for holding the liquid fuel and for permitting its mixing with air at the temperature, pressures and air flow velocities present in cigarette 10. The preferred fuel is liquid absolute ethanol. At ambient temperature ethanol to air ratios ranging from 3.3 to 19.0 (by volume) are preferred.
Other combustible fuels such as alcohols, esters, hydrocarbons, methanol, isopropanol, hexane, methyl carbonates of alcoholic flavorings, etc. may be used. Further, heat release fuels may be used which fuels are relatively non-volatile fuel precursors consisting of a volatile fuel component chemically or physically bonded to a support material. Upon heating the volatile fuel component is released. Such fuels have the advantage of preventing evaporative loss of fuel during storage and ensuring the release of fuel in controlled and limited quantities sufficient for combustion and heat generation. Examples of heat release fuels are menthol methyl carbonate, dimethylcarbonate, triethylorthoformate, alcohol absorbed on celite or molecular sieves and "STERNO" brand fuel.
Finally, catalytic activity occurs in section 17 which includes mixture supply tube 24 and inner catalytic-containing ceramic tube 26 which houses honeycomb 25 employing a frictional fit or other attachment means. Ceramic tubes 24, 26 are composed of a dense mullite (3Al 2 O 3 .2SiO 2 ) in a glassy matrix. The material is fine-grained high temperature operative and nonporous. The material has a bulk specific gravity of 2.4; a working temperature of 1650° C. and a flexural strength of 20,000 psi. Tubes 24 and 26 are preferably made of heat resistant material such as MV20 mullite ceramic tubes from McDanel Refractory Co. Catalytic unit 25 which preferably is Celcor or Celcor 9475 honeycomb ceramic material coated with an alumina, and then coated with a catalyst coating material including a rare earth or transition oxide, such as cerium (IV) oxide, and finally are coated with a catalytic coating material including a precious metal solution, preferably, palladium or platinum. After such coating treatment the honeycomb substrate 25 (see FIGS. 3a-d) is placed in cigarette tube 26 (FIGS. 1, 1a and 2). In addition to ceramic material any other suitable non-combustible catalyst support material can be used such as non-woven carbon mat, graphite felt, carbon fiber yarn, carbon felt, woven ceramic fibers, monolith materials. Monolith materials, also referred to as honeycomb materials, are commercially available, (e.g., from Corning Glass Works, Corning, N.Y.). Transition oxides such as Ta 2 O 5 , ZnO, ZrO 2 , MgTiO 3 , LaCoO 3 , RuO 2 , CuO, MnO 2 , and ZnO may be used instead of cerium oxide.
Honeycomb substrate 25 has low pressure drop, high surface area and a high thermal and mechanical strength. Honeycomb structures have a low pressure drop (the difference in pressure created when pulling air through the support) compared to a tightly packed ceramic fiber material. A typical pressure drop (draw resistance) of a cigarette is five (5) inches of water (gauge), such pressure being measured at the mouth end of the cigarette. The honeycomb preferably has square cells and a formula of 2MgO.2Al 2 O 3 .5SiO 2 . The honeycomb has open porosity of 33%; mean pore size of 3.5 microns coefficient of thermal expansion (25-1000° C.×10 -7 /° C. of 10 and a melting temperature of about 1450° C. The honeycomb material forms a heterogeneous catalyst.
With respect to FIG. 3a, honeycomb 25 includes sixteen (16) cells 29. The dimensions of honeycomb 25 are a=5.7 mm; b=5.7 mm and c equals 7 mm. In FIG. 3b, honeycomb 25 includes nine (9) cells 29. The dimensions of honeycomb 25 are: d=4.5 mm, e=4.5 mm and f=7 mm. In FIGS. 3c and 3d dimensions g=13.09±1.17 mm; h=4.3 mm; i=1.8 mm; j=1.8 mm; k=4.3 mm; l=12.29±0.69 mm; m=2.0 mm and n=3.0 mm. FIG. 3c shows a unit with five (5) cells and FIG. 3d shows a unit with two (2) cells.
Subsequent to the aluminum oxide stabilizer wash coating, which wash coat is stabilized for high temperatures present in the device, honeycomb substrate 25 receives a catalytic treatment. Configurations of Celcor Cordierite illustrated in FIGS. 3a-d were catalyzed by treatment as set out in the following examples.
EXAMPLE 1
Two hundred (200) units of Celcor Cordierite #9475 monolith ceramic honeycomb material (2MgO.2Al 2 O 3 .5SiO 2 ; coated with δ-Al 2 O 3 stabilizer for high temperature performance, diameter: 4 inch; height: 1 inch; having 400 cells per square inch) was cut into square sections, monolith units, consisting of nine (9) cells with dimensions 4.5 mm×4.5 mm×7 mm (FIG. 3b). The honeycomb material was dried 110° C. for about 0.5 to 3 hours to reduce the level of occluded or adhered liquid (including H 2 O). The two hundred (200) units were then introduced into a heated (90°C.) solution consisting of 200 ml of deionized distilled water and 17.3692 g Ce(NO 3 ) 3 .6H 2 O. Ce(NO 3 ) 3 is soluble in water. The monolith units, which were agitated by hand every 10 minutes were kept in the heated solution for one-half hour. After removing from the solution, excess liquid was blown from the monolith units with compressed air. The monolith units were then placed on a glass Petri dish and heated at 60° C. on a hot plate for 20 minutes. The monolith units were then dried in air at 110° C. for 1 hour. The above treatment was repeated two more times to give a total of 3 treatments with the Ce(NO 3 ) 3 solution. After the third and final treatment, the monolith units were dried in air at 110° C. overnight so as to substantially dry the impregnated material, and then calcined in air at 550° C. for 5 hours.
The two hundred (200) units so impregnated with Ce(NO 3 ) 3 were divided into four (4) equal lots. Each lot was treated with one of four different solutions of PdCl 2 .
Solution 1
A 2% (wt/vol) Pd solution prepared by diluting 15.7233 ml PdCl 2 solution (0.0318 g Pd/ml) to 25 ml with deionized distilled water.
Solution 2
A 1% (wt/vol) Pd solution prepared by diluting 15.7233 ml PdCl 2 solution (0.0318 g Pd/ml) to 50 ml with deionized distilled water.
Solution 3
A 0.5% (wt/vol) Pd solution prepared by diluting 15.7233 ml PdCl 2 solution (0.0318 g Pd/ml) to 100 ml with deionized distilled water.
Solution 4
A 0.25% (wt/vol) Pd solution prepared by diluting 15.7233 ml PdCl 2 solution (0.0318 g Pd/ml) to 200 ml with deionized distilled water.
Fifty (50) Ce(NO 3 ) 3 impregnated monolith units were added to Solution 1 and heated to 70-80° C. Fifty (50) monolith units were added to each of the other Solutions 2-4 in the same manner. In each case, the monolith units, which were agitated by hand every 10 minutes, were kept in the heated solution for 1 hour. After removing from the solutions, excess liquid was blown from the monolith units with compressed air. The monolith units were then placed on a glass Petri dish and heated at 60° C. on a hot plate for 20 minutes
The monolith units were then dried in air at 110° C. overnight and then calcined in air at 550° C. for 5 hours. The units so treated were found useful in the practice of this
EXAMPLE 2
About three hundred (300) dried monolith units, consisting of two (2) cells (FIG. 3d) with dimensions 3 mm×3 mm×12.3 mm, were impregnated with Ce(NO 3 ) 3 .6H 2 O in a similar manner to that described in Example 1 except that 26.0538 g of Ce(NO 3 ) 3 .6H 2 O in 150 ml deionized distilled water was used.
One hundred of the three hundred (300) Ce(NO 3 ) 3 impregnated monolith units were treated with a heated (70°C.) solution containing 1.6667 g PdCl 2 , 0.25 ml H 2 PtCl 6 (8 wt % solution in water), 10 ml HCl (1M) and 90 ml deionized distilled water in a similar manner to that described in Example 1. The one hundred treated units were found useful in the practice of the present invention.
EXAMPLE 3
About 60 dried nine (9) cell monolith units were impregnated with Ce(NO 3 ) 3 .6H 2 O in a similar manner to that described in Example 1 except that 8.6846 g of Ce(NO 3 ) 3 .6H 2 O in 100 ml deionized distilled water was used.
About 30 of the Ce(NO 3 ) 3 impregnated monolith units were treated with a heated (90°C.) solution containing 6.445 g ZrCl 2 O.8H 2 O in 100 ml of deionized distilled water. The monolith units, which were agitated by hand every 5 minutes, were kept in the heated solution for 0.5 hour. After removing from the solution, excess liquid was blown from the monolith units with compressed air. The monolith units were then placed on a glass Petri dish and heated at 60° C. on a hot plate for 20 minutes. The monolith units were dried in air at 110° C. for 1 hour. The above treatment was repeated two more times to give a total of 3 treatments with the ZrCl 2 O.8H 2 O solution. After the third and final treatment, the monolith units were dried in air at 110° C. overnight so as to substantially dry the impregnated material, and then calcined in air at 720° C. for 5 hours. The about thirty units were found useful in the practice of this invention.
EXAMPLE 4
Fifteen (15) treated monolith units from Example 3 were added to a 0.005 wt % Pt solution prepared by diluting 0.125 ml platinum chloride solution (8 wt % Pt in water) to 200 ml with deionized distilled water. After being immersed in the solution for 10 minutes, the monolith units were removed and excess liquid removed with compressed air. The monolith units were then placed on a glass Petri dish and heated at 60° C. on a hot plate for 20 minutes. The monolith units were then dried in air at 110° C. overnight and then calcined in air at 720° C. for 5 hours. The fifteen units so treated were useful in the practice of the present invention.
EXAMPLE 5
About thirty (30) dried 9 cell monolith units were impregnated with ZrCl 2 O.8H 2 O in a similar manner to that described in Example 3.
Fifteen (15) of the ZrCl 2 O.8H 2 O impregnated monolith units were treated with Ce(NO 3 ) 3 .6H 2 O in a similar manner to that described in Example 3 except that a calcination temperature of 720° C. was used. The fifteen units so treated were useful in the practice of the present invention.
EXAMPLE 6
Fifteen (15) treated monolith units from Example 5 were treated with a 0.005% Pt solution in a similar manner to that described in Example 4.
Ceramic cordierite units may have cell densities from 9 to 400 cell/in 2 . Such cells are coated with a uniform layer of gamma (γ) alumina to increase the stability and the coating surface by one hundred fold or more as described in the Examples above. Generally, the alumina coating is in turn coated with a solution of Ce(NO 3 ) 31 or a slurry of ceria (cerium oxide: CeO 2 ). Cerium nitrate Ce(NO 3 ) 3 is preferred because a more uniform coating can be obtained. Cerium compounds including cerium (III) oxalate carbonate, or nitrate may be used as starter materials provided they are converted to cerium (IV) oxide prior to use in the invention.
Finally, a third coat of a dilute solution of platinum chloride or palladium chloride is applied on the cerium containing coating. These catalyst coatings, when activated (as combustion is initiated) generate temperatures from about 700° C. up to 1000° C. The high temperatures assist in achieving complete combustion of the liquid fuel and air mixture and achieving the further combustion of carbon monoxide (CO).
In the operation of cigarette 10, the smoker draws on mouthpiece section 11 causing outside air to flow through side holes 21 in fuel storage and air mixing section 16 and, in addition, outside air to flow through end hole 31 in section 17 (see 4) air flow arrows AF 1 and AF 2 arrows B 1 and B 2 (FIG. 2)). Outside air flow represented by arrows AF 1 and AF 2 passes through reservoir 16 containing ethanol fuel where a fuel/air mixture is formed. The air/fuel mixture is saturated as it exits reservoir 22. The air/fuel ratio is increased with air drawn through tip opening 31 before the mixture contacts the catalyst surfaces of honeycomb 25. The catalytic surfaces over which the gases flow are about 16 to 65 m 2 /g. The fuel/air mixture changes direction and commences flowing toward mouthpiece 11. As the air/fuel mixture flows, it comes into contact with coated ceramic honeycomb 25 inside tube 26 as the cigarette 10 is lit with a conventional lighter by applying the lighter to the area of tip hole 31. As the gases continue to move toward mouthpiece 11 they are heated by catalyzed combustion (see arrow AR 1 and AR 4 ; FIG. 2). Gas flow continues through delivery tube 27.
As the smoker continues to draw on cigarette 10, combustion gases pass out of delivery tube 27 through glycerin containing plug support 19 forming glycerin aerosol which flows through section 10 picking up flavors from cut tobacco 12a. The aerosol laden with flavorants finally passes through mouthpiece filter 11 to the smoker's mouth. When the smoker stops drawing the catalyst retains sufficient heat in section 17 so that upon the smoker's taking second and subsequent drags combustion will resume without the requirement of relighting.
The products of combustion exiting delivery tube 27 and finally reaching the smoker's mouth are water, CO 2 and CO. The weight of CO per cigarette is less than the weight found in standard cigarettes presently being sold. For example, cigarettes of the present invention have 0.2 mg or below of CO per cigarette.
Reductions in CO are attributable to the procedure in which mixture of air and fuel pass through the honeycomb material which functions as coated and catalyst as herein described. During such flow catalytic action causes oxidation of CO to CO 2 to substantially reduce the CO content as such gases exit tube 27.
In view of the heat generated in combustion section 17 his section may be insulated using aluminum foil/paper laminates, graphite foil, glass fiber, non-woven carbon mats and woven ceramic fibers. Such insulation also maintains the catalyst above its light-off (activation) temperature between puffs.
The catalyst containing portion of the smoking article can be reused. It is contemplated a pack or carton of smoking articles may include one or more catalyst units to which the smoker would attach to the end of the smoking device.
The term "smokeless" means to many in the cigarette industry, a device that heats rather than burns the tobacco. "Flameless" refers to catalytic flameless combustion including catalytic oxidation of volatile organic vapors on a metal or metal oxide. The present inventive device is both "smokeless" and "flameless".
When all the fuel in reservoir 22 has been consumed, cigarette 10 extinguishes itself. Cigarette 10 is designed to produce about 6 to 12 puffs. | A smoking article and its method of construction and operation to provide products of combustion which are used to form flavorable aerosol gases delivered to the smoker's mouth while controlling the composition of such gases of combustion. Hot gases generated in a catalytic section in which fuel and air combust aided by a honeycomb catalytically coated surface including alumina and a cerium compound. | 0 |
FIELD OF THE INVENTION
The present invention generally relates to the field of computers, and particularly to providing sufficient memory for option ROM expansion.
BACKGROUND OF THE INVENTION
The personal computer system is usually booted during a power up sequence using system software and information stored within a system read-only-memory (ROM). Since the system ROM is non-volatile, the ROM contains reliable data or instructions to boot up the system at least to a point where the disk operating system (DOS) can be loaded to complete the boot-up sequence. The Basic I/O System (BIOS) is a set of routines that works closely with the hardware to support the transfer of information between elements of the system, such as memory, disks, and the monitor. The system ROM stores the operating system program, such as BIOS, which is executed upon power-up by the microprocessor to initialize the system, as well as to perform a power-on self-test (POST) and to provide certain low level, hardware dependent support for the display, disk drives, and peripheral devices. More sophisticated routines and data may be included in the system ROM, depending upon the needs and complexity of a given computer system. BIOS code provides the lowest level of interface between the operating system and the hardware. On a system reset or power-on, the typical system retrieves the boot up instructions and data from the 1 megabyte or other size memory where they are stored. Further, a checksum routine is typically executed to verify the status of the BIOS currently available to the system. If the integrity of the BIOS is determined to be good, the boot code initializes the system and its peripherals and passes control to the operating system.
Peripheral Component Interconnect (PCI) is a high-performance, 32-bit or 64-bit bus designed to be used with devices that have high bandwidth requirements, such as display subsystems. Small Computer Standard Interface (SCSI) is an I/O bus designed as a method for connecting several classes of peripherals to a host system without requiring modifications to generic hardware and software. The Configuration Manager is a system component that drives the process of locating devices, setting up their nodes in the hardware tree, and running the resource allocation process. Each of the modes of configuration management (real mode, virtual mode, and protected mode) have their own configuration managers.
The option ROM is a real mode driver designed to manage the resources of some piece(s) of hardware. Its normal operating environment will not allow the code to exceed 64 K, nor will it permit access to code larger than 64 K even if it exists. The environment normally available to an option ROM in a personal computer (PC) is constricted by many legacy requirements. An example of those limits are the 1 megabyte X86 processor Real Mode memory limit, the space allocated for an option ROM runtime images which is usually 128K for all images. Other legacy devices lack universal memory manipulation routines for reserving and using memory and do not comply with the general requirement that unused memory be released as soon as possible.
Because of these restrictions, adding features and meeting industry standard requirements has become almost impossible. Option ROMs are limited to 64 K in size, the nominal maximum, and cannot grow and still operate in all but a few PCs.
There are various other problems involving the limited memory of option ROMs. The initialization time memory generally allocated for option ROM expansion is limited. The run time memory generally allocated for an option ROM is limited. The system expansion location for option ROMs is privileged information, not generally available to the option ROM. The initialization time memory allocation is not universally available on PC platforms. A nominal 64 K limit on option ROMs limits the addition of functionality and features. RAID recognition is a feature which requires access to normally unavailable memory. Simple Boot Support is a feature that requires access to normally unavailable memory.
Therefore, it would be desirable to provide an expanded memory capability for option ROMs.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a method and apparatus for expanding option ROM memory capabilities by using PCI function calls that allow function calls and 32 bit addressing of the FLASH option ROM and an associated FLASH memory.
In a first aspect of the present invention, a method for accessing, via the commands of an adapter, from a read/limited write memory having a first size, a memory area having a second size greater in size than the first size, includes the steps of preparing a load image for transfer to the read/limited write memory, making a determination of the size of the load image, initializing the read/limited write memory to enable addressing of the memory area, and making function calls to enable a configuration space for the adapter.
In a second aspect of the invention, a computer system is disclosed which has an adapter which provides control signals and data to other devices, a read/limited write memory having a first size and being coupled to the adapter to effect data transfers, and a main memory having a second size that is greater than the first size and being used to store an overflow image in a data transfer to the read/limited write memory when the load image to be transferred to the read/limited write memory has a size which exceeds the first size.
In a third aspect of the invention, a computer system which presumes a first size for a FLASH option ROM has an adapter having system BIOS and a non-volatile memory having a second size. The second size is greater than the first size. The system BIOS initiates loading into the non-volatile memory. PCI function calls are made to enable configuration space for the adapter in Big Real Mode.
In a fourth aspect of the invention, a method for using a non-volatile memory as an expanded option ROM includes the steps of using a system BIOS to enter Big Real Mode and making function calls to enable configuration space for an adapter on which the system BIOS resides.
In a fifth aspect of the invention, a method for switching operational modes for transferring data to and from an non-volatile memory the steps of a system BIOS being placed in a first operational mode and initiating process code, separate from the system BIOS and responsive to processing by the system BIOS, that ensures the system BIOS enters a second operational mode or prevents the system BIOS from leaving the second operational mode, in which the second operational mode supports a larger address space than the first operational mode.
The present invention combines various abilities such as placing the system in Big Real Mode if it is not already in that mode, locating the adapters PCI configuration registers, enable/re-enable the FLASH ROM memory on the adapter in a readable free memory space, validating the FLASH ROM memory, copying all or a portion of the FLASH ROM into main memory (below 1 MB), disabling/reverting the FLASH ROM memory to a known state, quitting Big Real Mode if it was started by the process of the present invention, and then using the code/data that was copied from the FLASH ROM to extend/enhance the capabilities of the normal load image and run time binary.
Using an undocumented series of X86 processor instructions that are supported across the X386 and beyond processors, including AMD and Transmeta, an environment is created for the initialization time option ROM that allows access to 4 Gigabytes of linear memory. Using that mechanism, and documented PCI entry points and function calls, the PCI configuration registers for the PCI adapter that the option ROM is booted from are located. The FLASH option ROM image is accessed in its raw form. By this method, the entire option ROM image is accessed, and not just the first 64 K or less that the PC system BIOS would ordinarily use.
The present invention gains access to the FLASH image of the option ROM.
The present invention provides a way to make use of more code and data in an option ROM.
It is to be understood that both the forgoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed. The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate an embodiment of the invention and together with the general description, serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The numerous advantages of the present invention may be better understood by those skilled in the art by reference to the accompanying figures in which:
FIG. 1 illustrates a flow chart which lists the procedural steps in initializing an expanded option ROM memory using PCI function calls;
FIG. 2 illustrates a division of the FLASH memory associated with the option ROM capable of being addressed by 32 bits; and
FIG. 3 illustrates a functional block diagram showing a processor, option ROM, and expanded memory associated with the option ROM; and
FIG. 4 illustrates a diagram of memory as used in the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings.
Referring generally now to FIGS. 1 through 3, exemplary embodiments of the present invention are shown.
The invention makes use of some infrequently used capabilities that are supported by the X86 family of processors, in combination with functions of the PCI specification that are not usually associated with ROM initialization.
Real mode is a single-tasking execution mode supported by the Intel 80286 and later processors. It is an operating mode of x86 chips that replicates the memory management used by 8086 or 8088 chips, although they run much faster. In Real Mode, the running program has full access to the computer's memory and peripherals. In real mode, all of the CPU's protection features are disabled, paging is not supported, and program addresses correspond to physical memory addresses. The address space is limited to 1 MB of physical memory and uses a memory segmentation scheme. Other modes which exist are protected mode and virtual mode. The DOS operating system was not designed to take advantage of protected mode, so it always executes programs in real mode unless a protected mode extender is run first. Real mode limits the processor to 1 MB of memory and provides no memory management or memory protection features. The phrase is often used to describe device drivers that operate in this mode. MS-DOS runs in real mode.
The present invention may be used with a SCSI Device Management System (SDMS) BIOS. This is an SCSI option ROM used for PCI-SCSI devices. It contains a flash utility to update SDMS BIOS onboard host adapters. An adapter is a device such as a circuit that performs a specific function, such as a parallel port.
Big Real Mode (also called 32 bit Real Mode, UnReal Mode and Flat Real Mode) is used to provide access to memory within a 4 Gb linear address space. The X86 processor runs in two distinct modes as described in the Intel processor data sheets. The processor starts in Real Mode with an addressing limit of 1 MB (actually 1 MB 64 K−1 paragraph=16 bytes), and may be switched to Protected Mode, with a multi-terabyte access range using page tables.
Big Real Mode is commonly found in applications that run under real mode operating systems like MS-DOS, PC-DOS, and DR-DOS. DR-DOS provides a full multitasking environment on Pentium, 486, or 386-based hardware, has memory management extensions provided in the operating system, and has programs that can have direct access to create separate threads via the extended Application Programming Interface. Big Real Mode is attained by manipulating the processor into Protected Mode, setting up control registers, and exiting to Real Mode without resetting the special registers.
It is not required that Big Real Mode be the method used to access memory above 1 MB and below 4 GB. Other programming methods, protected mode for example, and methods using hardware could be used to accomplish the same objective. (Big Real Mode is preferred due to simplicity and the fact that hardware may not be available.)
A FLASH ROM is a large capacity, reprogrammable storage device that can store the POST and BIOS routines required for the initialization and operation of the computer system. The FLASH ROM is a non-volatile semiconductor integrated circuit which is derived from EPROM and EEPROM technologies. The architecture of flash chips is based on the idea that it will be seldom written to but will be read often. Because the FLASH ROM may be reprogrammed without being removed from the system, the FLASH ROM provides a greater convenience in making required software updates as compared to conventional ROMs.
Often, the FLASH ROM has spare storage capacity to accept codes intended for the microcontroller. The FLASH ROM has been shared between the microprocessor and a microcontroller. In such systems, the microprocessor possesses control of the FLASH ROM during the power-on reset and boot-up. After the microprocessor has determined the system is properly up and running, the microprocessor copies the BIOS code stored in the FLASH ROM to its main memory array to enhance the performance of the computer system because memory access speed is much quicker for the main memory array than it is for the FLASH ROM.
Various system BIOSs treat PCI configuration registers differently. Some may leave the FLASH ROM address alone, others may zero it out, and still others could leave it accessible. System firmware may be used to read or write to the PCI configuration registers during the startup process. The PCI configuration registers are generally a mixture of read-only registers and read/write registers. Read-only registers may include registers specifically dedicated to one of device id, vendor ID, status, class code, revision ID, header type, subsystem ID, subsystem vendor ID, interrupt pin, and other data. Read/write registers may include registers specifically dedicated to one of command, latency time, cache line size, base address registers, expansion ROM base address, interrupt line, and other data.
Various System BIOS's have code that enables and makes use of Big Real Mode for internal operations as permitted by certain Post Memory Manager (PMM) specifications. When the System BIOS enables Big Real Mode, the process code of the present invention detects this occurrence and prevents Big Real Mode from being disabled when the option ROM has finished using it, leaving it to the System BIOS to disable it.
Because the method may enable memory that conflicts with other existing memory, a test should be made to detect that possibility. Validation is a process used to verify the integrity or some other aspect of the transmitted information. Validation might include finding signatures, checksumming the contents of the memory to a known value, or any method that ‘proves’ the memory is usable. If conflicting memory is found, the code continues to loop (up to some practical limit) looking for memory that will validate. When found, the sequence continues. If not found, the sequence aborts. (An abort could be limiting or disabling depending on the implementation.) Validation may be desirable in some applications.
The undocumented series of X86 processor instructions are those instructions which actually exist but have not been written about or acknowledged in data manuals by their source company. However, they have been discovered and written about by published reference books. For example, reference books detail them as “Undocumented Instructions”.
In FIG. 1, the method for accessing ROM PCI memory above 64 K starts involves the initial step 10 in which the system BIOS puts the load image in FLASH option ROM memory. The system BIOS only needs to find the beginning of the loader program. The access code in the loader finds the remainder of the loader program.
In step 20 , the system BIOS runs the FLASH option ROM initialization code. Upon receipt of a subroutine call from an operating system or application programs, the system BIOS performs the actual hardware control. The BIOS includes a boot strap routine that is performed when the system is powered on and a routine for handling interrupt requests generated by the host adapter. The BIOS coordinates the initializing of the FLASH option ROM memory.
In step 30 , initialization begins. The code enables 32 bit real mode memory addressing, up to 4 gigabytes. BIOS looks for a peripheral component interconnect (PCI) bus and, if it finds one, checks all the PCI cards.
In step 40 , PCI function calls are made. Step 40 contains undocumented instruction sequences to verify/validate the memory spaces that are exposed by the calls. PCI function calls are made to enable the non-volatile memory at addresses which may or may not conflict with preexisting memory regions. Interspersed in step 40 are ‘Big Real Mode’ sequences that verify/validate those memory regions and determined their non-conflicting status. (Physically, the memory exists, but until the PCI calls are made, the memory region will usually be unmapped and therefore inaccessible.) These function calls enable the configuration space for the adapter (e.g., the host computer) that initialized the process. The PCI configuration space is direct mapped into the adapter's address space. This allows the host system to access the PCI configuration registers. Each function in a PCI device has 256 bytes of block addressed configuration space.
PCI interrupt 1 Ah supports a number of functions that access configuration registers. A System BIOS is required to support these calls for PCI adapters. Some of the relevant functions include
PCI_FIND_PCI_DEVICE
EQU (02h)
PCI_READ_CONFIG_BYTE
EQU (08h)
PCI_READ_CONFIG_WORD
EQU (09h)
PCI_READ_CONFIG_DWORD
EQU (0Ah)
PCI_WRITE_CONFIG_BYTE
EQU (0Bh)
PCI_WRITE_CONFIG_WORD
EQU (0Ch)
PCI_WRITE_CONFIG_DWORD
EQU (0Dh).
In step 50 , the overflow image of the FLASH option ROM is accessed and validated. Validation may be performed through checksum calculations.
In step 60 , the code and/or data are copied from the overflow area into main memory.
In step 70 , PCI function calls disable/return configuration space to a previous state. Function calls of the PCI specification are used to read from and write to adapter configuration registers. These calls enable/re-enable/disable adapter memory at locations in Big Real Mode memory.
In step 80 , the initialization process continues using additional code and data from main memory below 1 megabyte.
FIG. 2 illustrates sections of the FLASH memory. This memory may be located on the host adapter. Loading starts in low address memory. All of the initialization code and data dedicated to the option ROM is contained in the one FLASH memory in this embodiment. Contiguous memory locations are used. Various operations occur in low address memory such as search and allocation. Memory size exceeds the 64 K traditionally found in the option ROM and may be as large as 4 Gb. The overflow code and data are stored in the overflow area of the FLASH memory and are not part of the load image. They are only accessible using Big Real Mode memory instructions after being specifically enabled using PCI configuration space reads and writes. The load image, its signature, length, and zero checksum are stored in the FLASH memory. The access code is the new code that allows access to otherwise unavailable PCI configuration memory.
In the particular example of FIG. 2, “55AA” represents the beginning of the option ROM, starting on the boundary of byte 512 and “nn” represents the number of 512 byte blocks there are in the option ROM to fix the load size (such as 64 K). A checksum is generated from the bytes in the nn * 512 area. That checksum, the sum of the digits in hexadecimal disregarding overflow, must by 0. If the checksum is correct, then the System BIOS treats the memory as an option ROM. Other configurations of the memory space may be achieved depending upon the application.
Alternate ways of practicing the invention may be employed which use the same access techniques, but perform other configuration space accesses that could modify other adapter memory to create a more unique execution environment, i.e., permanently change boot code before using it or modifying parameters to affect run-time behavior on a per boot basis.
Instead of using FLASH technology, the expanded memory portion may be implemented by battery backed RAM, EEPROM, EPROM, or even core or bubble memory. The expanded memory only needs to be effectively non-volatile.
FIG. 3 shows a functional block diagram of an embodiment of a computer system 100 having an adapter 102 coupled to an option ROM and a separate FLASH memory. In that case, the option ROM would contain the loader code with the separate FLASH memory containing the portion of memory that is changeable or upgradeable.
As separate units or devices, the FLASH memory may be a second option ROM or another memory device. Contiguous addressing may be employed depending upon the application. In various situations, it may be desirable or necessary to use other than contiguous addressing. If separate memories are used, they may be controlled through different configuration registers.
FIG. 4 illustrates an exemplary diagram of memory allocation by the present invention. In FLASH or similar memory, the lower addresses (e.g., 64 K) correspond to an option ROM. Main memory includes memory addresses up to 1 megabyte. This corresponds to access by Real Mode. Overflow code and data image memory (or, overflow memory) is memory having address above 1 megabyte to 4 gigabytes. The overflow memory and PCI adapter FLASH memory are addressed using Big Real Mode memory accesses. The PCI adapter memory space is enabled using Peripheral Component Interface (PCI) bus function calls, such as PCI_FIND_PCI_DEVICE, PCI_READ_CONFIG_WORD and PCI_WRITE_CONFIG_DWORD.
The present invention is not limited to a certain family of processors and may be practiced with a variety of control devices. The expanded memory 120 is addressable by 32 bits, yielding a capacity of 4 GB. The addressing capability, due to Big Real Mode limitations, is not limited to 4 GB or 32 bits. Other sizes are possible depending upon the application. Since the expanded memory 120 uses FLASH technology, it is not expected to be written to with high frequency. The adapter 102 may be a microprocessor such as an X86 processor. The option ROM and FLASH memory are shown as separate units; however, they may be physically or logically integrated into one unit or device. If the option ROM and FLASH memory were separate units or devices, they would not need to have contiguous addressing.
The present invention overcomes deficiencies encountered by option ROMs such as RAID recognition and the inability to use the Simple Boot Support feature. These features require access to memory that is not normally accessible to an option ROM BIOS.
In RAID recognition, Redundant Array of Independent Disk Drives (RAID) control may be implemented in many ways. A dedicated processor closely coupled to the adapter may be provided to control the drives. Software may be used to take over the control of an existing adapter. If another process takes over the adapter, contention with the process of the present invention needs to be resolved. This may be done by having the other process write into the memory space of the adapter. Big Real Mode provides access to that memory space used by the other process. The process of the present invention uses access code which makes use of the X86 chip's ability to get into Big Real Mode and “peek/poke” memory that would otherwise be inaccessible without the control of the adapter configuration registers with PCI function calls.
Like RAID recognition, Simple Boot Support requires the process code of the present invention to ‘peek/poke’ memory outside the normal Real Mode 1 MB limit. Peak/poke memory is read/write memory which are accessed outside normal operations. For example, video calls are function calls to display elements of an image are normal ways that programs put new information on a display screen. However, it may be more efficient and faster if, instead of function calls, data is directly written into video memory; the process which does this is peeking and poking memory.
Simple Boot (also called Quick Boot) is part of a Microsoft initiative that aims to make the PC seem to be more like any other appliance. Instead of locating all drives, only the boot drive is located, initialized, and accessed. This, combined with other optimizations, speeds up the boot process. The process code of the present invention probes Big Real Mode memory to find out the state of the “Simple Boot Flag” which determines whether all the drives are to be located or if only the boot drive is to be located.
The intermediate device that controls access to the memory is a configurable register located on the adapter that is associated with the memory. Writing the configuration register with a 32 bit address (limited by unchangeable low order bits in the register) locates that memory at the address specified. A 32 bit value may be written in the register that will locate the memory at an address space which already exists. Several registers on the chip with the same address may be written so that various memory regions on the adapter conflict with one another. If, for example, for a 128 K FLASH memory, a register could be written with 1111 1111 1111 1110 0000 0000 0000 0000 0000b. This would enable the FLASH memory at an address range of FFFE0000h to FFFFFFFF. An adapter may also accept bits in the low order positions.
The method and apparatus of the present invention may be applied to expand the memory capability of an option ROM or to memory expansion in general.
It is believed that the method and apparatus for accessing ROM PCI memory above 64 K of the present invention and many of its attendant advantages will be understood by the forgoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely an explanatory embodiment thereof. It is the intention of the following claims to encompass and include such changes. | A method for augmenting the memory capabilities of an option ROM in which PCI function calls are used to access a larger sized non-volatile memory. Thirty two bit addressing is used in the PCI function call routines to allow for 4 GB addressing. An option ROM and the separate larger sized non-volatile memory or a single non-volatile memory may be used for storing the overflow images. | 6 |
BACKGROUND
Although a number of shelters, tents and insulation systems are known or have been suggested in the art, they all have or would have disadvantages. Japanese Patent No. 2004-132006 (Kawahara), for example, discloses a heat-insulating layer for a tent. An air layer D is formed between the tent 3 and a canopy sheet 5. As shown in FIG. 4 of Kawahara, cylindrical members 4 are attached to the exterior cover 5 by staple-shaped elements 8. The Kawahara tent requires a device f for forcing air through a duct d, which would waste energy, and the Kawahara tent is unduly complicated and unreliable, and it would be difficult to transport and set up, especially in remote, harsh environments.
U.S. Patent Application Publication No. 2009/0188539 (Hollinger) refers to the use of inert gas or low pressure within hollow or airtight tubes 901, 911 (FIGS. 9A, 9B) to provide insulation within a multi-layer tent. The Hollinger tent would require a source of inert gas, which would be impracticable, or inflation/deflation of the tubes, and the tubes would be subject to puncturing and damage, or additional construction expense would be required to make them sufficiently rugged. The Hollinger tent is unduly complicated and unreliable, and would be difficult to transport and set up, especially in remote, harsh environments.
Japanese Patent No. 2006-265849 to Shimizu discloses a fabric shelter (FIG. 14), and other shelters known in the art are shown in U.S. Pat. No. 4,102,352 (Kirkham), U.S. Pat. No. 4,607,655 (Wagner et al.), and U.S. Pat. No. 7,178,483 (Wu).
SUMMARY
The disadvantages of the prior art can be overcome to a great extent by a portable, insulated shelter that has flexible inner and outer layers, and lightweight fabric insulation panels located between the inner and outer layers. The shelter may be used, for example, to shelter human occupants in harsh, remote environments. In a preferred embodiment, the inner layer provides the inner surfaces of the shelter, and provides a living space by surrounding the occupants above and on all sides thereof.
The fabric panels may be connected together to provide thermal insulation for the shelter, by surrounding the flexible inner layer above and on all sides thereof. The outer layer may be used to protect the fabric panels (or the inner layer/liner when the fabric panels are not installed) from wind, rain, ice and snow. The flexible outer layer is preferably located outside of the fabric panels, and the shelter has only three layers, such that the fabric panels are sandwiched between the inner layer and the outer layer.
In a preferred embodiment of the invention, the fabric panels each include multiple layers of materials sandwiched together, and the fabric panels are removably connected to each other, and to the frame, by hook and loop fasteners.
In a preferred embodiment of the invention, the shelter may be supported by an exterior frame, made up, for example, of aluminum poles that can be disassembled. The invention is not limited, however to the preferred embodiments. The shelter may be supported by an interior frame made of arches and purlins, in a Quonset but configuration, and/or by other suitable support structures.
In a preferred embodiment of the invention, an HVAC unit is used to provide heat and/or cooling for the shelter occupants. The unit may be powered by electricity, liquid hydrocarbon fuel, or other suitable power sources. In a preferred embodiment, the shelter may be designed to maintain an interior temperature of about seventy degrees Fahrenheit, for outside ambient temperatures in the range of from about minus twenty-five degrees to plus one hundred and twenty-five degrees Fahrenheit, with significant reduction in energy power requirements compared to conventional shelters.
The disadvantages of the prior art may also be overcome to a great extent by using a portable, insulated shelter to protect human occupants in a harsh, remote environment, where the shelter has a liner and an outer layer, and a fabric insulation layer located between the flexible inner and outer layers. According to this aspect of the invention, the flexible inner layer provides the inner surfaces of the shelter, surrounding the occupants above and on all sides thereof, and the fabric insulation panels are installed and/or removed after the inner and outer layers of the shelter are provided.
When the fabric panels are installed, they are sandwiched between the inner and outer layers, and thereby provide thermal insulation for the shelter. In a preferred, especially compact and convenient embodiment of the invention, the top and side walls of the shelter do not have any layers other than the inner and outer layers and the fabric insulation panels.
In a preferred embodiment of the invention, the shelter is convenient and easy to set up. Although a six-foot ladder may be used during assembly, the shelter otherwise can be installed without any special tools.
According to one aspect of the invention, when insulation is desired, the fabric panels are located between the inner and outer layers of the shelter, such that the inner layer of the shelter is provided by the same element in both insulated and non-insulated configurations. The shelter can be changed from a non-insulated to an insulated configuration without changing the interior space of the shelter. In other words, since there is an inner wall located inside the insulation, the shelter has a comfortable, finished configuration, even when the insulation panels are installed, and the inner layer is always located inside the frame elements, even when the insulation panels are not installed. Thus, the insulation system described herein is particularly well suited for providing livable interior conditions in harsh climates, using portable fabric shelters, tents and other soft-walled structures.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1A is a perspective view of a shelter constructed in accordance with a preferred embodiment of the present invention, in a non-insulated configuration.
FIG. 1B is a perspective view of the shelter of FIG. 1A , in an insulated configuration, with insulation panels located between an outer cover and an inner liner.
FIG. 2 is another perspective view of the shelter of FIGS. 1A and 1B , looking into the shelter from the front to the back, with the front of the shelter removed, and with the liner removed.
FIG. 3 is an enlarged view of portion 3 of FIG. 2 , showing a purlin-arch connection.
FIG. 4 is a perspective view of a portion of the shelter of FIGS. 1A and 1B , viewed from inside the shelter, with the liner removed, and with two insulation panels connected to respective arches.
FIG. 5 is a front perspective view, like FIG. 2 , with all of the insulation panels installed, and with one of the liner sections partially re-installed.
FIG. 6 is an enlarged view of portion 3 of FIG. 2 , showing two liner sections surrounding the purlin-arch connection.
FIG. 7 is an enlarged view of a portion of the shelter of FIG. 1B , showing a hook and loop connection between a fifth insulation panel and a sixth arch.
FIG. 8 is a perspective view of a front portion of the shelter of FIG. 1B , viewed from inside the shelter.
FIG. 9A is a cross-sectional view taken along line 9 A of FIG. 1A , showing the liner and the outer cover.
FIG. 9B is a cross-sectional view taken along line 9 B of FIG. 1B , showing the liner, the insulation layer, and the cover.
DETAILED DESCRIPTION
Turning now to the drawings, where like reference numerals designate like elements, there is shown in FIG. 1A an exemplary shelter 10 constructed in accordance with a preferred embodiment of the present invention. The shelter 10 has a front wall 12 , a back wall (not shown), a roof 14 , and side walls 16 . The right side wall (not shown) is the mirror image of the left side wall 16 . The front and back walls 12 , the roof 14 , and the side walls 16 are supported by a suitable frame made of aluminum, steel, wood or the like, which has, by way of example, six arches 18 , 20 , 22 , 24 , 26 , 28 , three longitudinally-extending purlins 30 , 32 , 34 ( FIG. 2 ), and suitable floor-frame members 36 , 38 , 40 , 42 . Depending on expected wind and other conditions, the shelter 10 may be tied to the ground by suitable wires or ropes (not shown). The shelter 10 may have, for example, a Quonset but configuration, and may be, for example, about twenty feet wide and about thirty two and one-half feet long.
The front and back walls 12 of the shelter 10 may have a semi-circular configuration, and are secured to the frame 18 , 28 , 36 , 40 along their peripheries (that is, along the edges of the front and back walls 12 ). If desired, a door 50 ( FIGS. 1A , 1 B) and windows 52 , 54 may be located in the front wall 12 . The roof and side walls 14 , 16 may be formed of one or more rectangular, flexible pieces that extend flexibly from the ground on the right side of the shelter 10 , over the top of the shelter 10 , and to the ground on the left side of the shelter 10 . The front and back walls 12 , the roof 14 , and the side walls 16 are secured together along their peripheries (that is, seamed along all of their adjoining edges) to form a secure, weather-proof enclosure, such that the shelter 10 provides a comfortable interior space for the occupants (not shown), with interior surfaces (not shown in FIG. 1 ) that do not need to be changed or covered even when the shelter 10 is collapsed and taken down for transport to another location.
In a non-insulated configuration, the front and back walls 12 , and the roof and side walls 14 , 16 , across essentially their entire extents, have the two-layer configuration illustrated in FIGS. 1A and 9A . There is an inner fabric liner 70 with an inner surface 71 that faces inwardly toward the occupants (or storage space) inside the shelter 10 . The liner 70 is formed of five rectangular panels 72 , 74 , 76 , 78 , 80 that together are essentially coextensive with the roof and the sidewalls 14 , 16 . As such, the liner 70 covers essentially the entire living space (and/or storage space) provided by the shelter 10 . The liner 70 may be supported by the purlins 30 , 32 , 34 , as discussed in more detail below.
As shown in FIGS. 1B and 9B , an insulation layer 84 may be installed (and, if desired, removed from) between the liner 70 and the outer layer 86 of the shelter 10 . The insulation layer 84 , in the illustrated embodiment, is made up of five rectangular insulation panels 90 , 92 , 94 , 96 , 98 , only two of which can be seen in FIG. 1B , and only one of which ( 94 ) is shown, partially installed, in FIG. 2 . To install the insulation layer 84 , that is, to change the shelter configuration from that of FIG. 1A ( 9 A) to that of FIG. 1B ( 9 B), the inner layer 70 (all five liner panels 72 , 74 , 76 , 78 , 80 ) is completely removed, such that the inside of the shelter 10 is as shown in FIG. 2 . Then, a central insulation panel 94 is threaded between the outer layer 86 and the purlins 30 , 32 , 34 . In operation, the central insulation panel 94 is laid out on the floor of the shelter 10 and aligned with the center bay 106 . Then the panel 94 is lifted up and placed in position, by running the panel 94 over the three purlins 30 , 32 , 34 in the center bay 106 . In the installed configuration ( FIG. 1B ), the center insulation panel 94 is sandwiched between the purlins 30 , 32 , 34 and the outer cover 86 of the shelter 10 .
As shown in FIG. 3 , the front edge 114 of the center insulation panel 94 overlaps the third arch 22 , except where purlin cutouts 116 are provided to make room for purlin-arch connections 118 . The front edge 114 has one cutout 116 for each of three purlin-arch connections 118 , since there are three purlins 30 , 32 , 34 in the illustrated shelter 10 . The front edge 114 of the center insulation panel 94 also has hook and look tabs 120 that wrap around the third arch 22 to secure the panel 94 in the insulated configuration. The insulation panel 94 may be located so that any side windows (not shown) open down and toward the inside of the shelter 10 . The length of the insulation panel 94 is slightly longer than the length of the arches 22 , 24 , such that the ends 122 ( FIG. 2 ) of the panel 94 overlap the floor frame 38 , 42 .
The other four insulation panels 90 , 92 , 96 , 98 are essentially identical to the center panel 94 , and they are threaded, one at a time, between the cover 86 and the purlins 30 , 32 , 34 , and their front edges are connected to the respective first, second, fourth and fifth arches 18 , 20 , 24 , 26 by the same arrangement of hook and look tabs 120 and purlin cutouts 116 . Hook and loop inner seams 124 ( FIG. 4 ) that run essentially the entire lengths of the back edges 126 of the first four insulation panels 90 , 92 , 94 , 96 are then connected to corresponding hook and loop outer seams 128 that run along essentially the entire lengths of the front edges of the second through fifth insulation panels 92 , 94 , 96 , 98 . Each pair of seams 124 , 128 is interrupted in three places by the purlin cutouts 116 , to accommodate the purlin-arch connections. The overlapped seams 124 , 128 provide a sealed thermal barrier between the outside and the inside surfaces of the insulation layer 84 . In the insulated configuration, the arches 20 , 22 , 24 , 26 are located mostly outside of the insulation layer 84 . That is, the arches 20 , 22 , 24 , 26 are located between (1) the flexible seams 124 , 128 of the insulation layer 84 and (2) the flexible outer cover 86 .
Then, after the five insulation panels 90 , 92 , 94 , 96 , 98 are installed, connected to the respective arches, and seamed together, the liner panels 72 , 74 , 76 , 78 , 80 are returned to their original positions. FIG. 5 shows the center liner panel 76 being returned to its original position in the center bay 106 . The liner panels 72 , 74 , 76 , 78 , 80 are seamed together by, for example, hook and loop seams along their edges 134 , 136 ( FIG. 6 ), with suitable purlin cutouts 130 being provided to accommodate the purlin-arch connections 118 .
Liners for the front 12 and back of the shelter 10 may also be removed to permit installation of insulation. The front and back insulation layers and liners may be connected to the outer cover 86 and the first and sixth arches 18 , 28 and the front and back floor-frame members 36 , 40 by suitable zippers or hook and loop seams. Liners for the front and back of the shelter 10 may be installed as shown in FIG. 8 . When the door 50 is made of a flexible material, the liner 70 may be connected to the door 50 by a zipper. When the door is solid (not flexible), the liner 70 may be connected to the door by a suitable adhesive (not illustrated).
The outer layer 86 , which may be made of polyvinyl chloride (PVC), is essentially coextensive with the inner layer 70 (and therefore essentially coextensive with the front and back walls 12 , the roof 14 and the side walls 16 ). The inner layer (liner) 70 may be made of a lightweight polyethylene material. The outer fabric layer 86 completely surrounds the shelter 10 and thereby provides an outer fabric shell which operates as a noise barrier, and which protects all elements inside the outer layer 86 , including the frame elements, from wind, rain, snow and the like and which prevents insects and other pests from entering the shelter 10 .
Each insulation panel 90 , 92 , 94 , 96 , 98 may be made of lightweight, flexible material, and may be constructed of multiple layers 162 , 164 , 166 sandwiched together, as shown in FIG. 9B .
An HVAC unit 200 ( FIGS. 1A , 1 B) can be provided to supply heated, cooled, humidified and/or dehumidified air to the interior of the shelter 10 via suitable tubing 202 and sealed openings 204 through the shelter 10 . If desired, one of the insulating panels 98 may be provided with a pre-cut hole (not shown) to conveniently accommodate the tubing 202 without providing space for air drafts and/or pests to enter the shelter 10 . The HVAC unit 200 may be electric (and connected to a liquid-fueled generator) or may itself be fueled by gasoline, diesel fuel or the like. In a preferred embodiment of the invention, two stovepipe-type openings may be provided.
It can be very expensive to transport liquid fuel to remote locations. Consequently, an important advantage of the present invention is that it can provide an efficient insulating system, forming a three-layer shell around the occupants (or the storage space provided by the shelter 10 ), that reduces overall fuel consumption and that is also lightweight, and convenient to handle and install, and that provides a livable interior space without disrupting the inner surfaces of the interior space when the insulation pieces 90 , 92 , 94 , 96 , 98 are removed and installed. The insulation panels can be affixed in the space 212 ( FIGS. 9A , 9 B) between the inner and outer layers 70 , 86 when desired.
The invention is not limited to the structures, methods and instrumentalities described above and shown in the drawings. Among other things, the invention is not limited to the particular Quonset but configuration shown in the drawings, nor is it limited to the particular number or arrangement of illustrated frame elements. The invention may be implemented, for example, in a Gable-type shelter, and in a wide variety of other configurations. The invention is defined by the claims set forth below. | A portable, insulated shelter consists of flexible inner and outer layers, lightweight fabric panels located therebetween, and connected to each other, a suitable support frame, and a system, such as a HVAC unit and a suitable connector, for actively controlling the interior environment of the shelter. The shelter may be used to protect and provide livable conditions in harsh, remote locations. Methods of selectively installing and removing the fabric panels are also provided, along with methods of setting up and disassembling the shelter. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to equipment for drilling in subterranean formations. More particularly, the present invention is directed to a device which is incorporated in the drill string and which facilitates release of stuck portions of the drill string.
2. Brief Description of the Prior Art
Equipment used for lowering a drill bit into subterranean formations usually includes a string of drill pipes and a bottom hole assembly containing a plurality of drill collars. The drill collars are pipes which have larger diameter, thicker wall and therefore heavier weight than the drill pipes of the upper portions of the drill string. The drill collars are usually necessary for providing sufficient weight for the operation of the drill bit which is at the bottom of the assembly.
The drill string is rotated from the surface by a rotary table. In conventional drilling operations, the rotary table rotates the drill string and provides the power for driving the drill bit into the formation. In other drilling operations, the power to drive the drill bit is derived from a downhole motor.
The downhole motor is usually driven by the pressure of drilling mud which is continuously pumped downhole in the interior of the drill string and which rises to the surface between the walls of the bore hole and the exterior walls of the drill string.
As is well known, portions of the drill string, particularly the lower portions, occasionally become strongly attached, "differentially stuck", to walls of the bore hole. The reason for this is that the external diameter of the drill collars is relatively close to the diameter of the bore hole, and that the drilling mud is circulated in the bore hole under high pressure. This pressure often exceeds several thousands of pounds per square inch (psi). When for some reason, pressurized drilling mud is excluded from between the wall of the drill collar and the subterranean formation then the hydrostatic pressure prevailing in the hole presses the drill collar against the formation with tremendous force. Most frequently such "differential sticking" of a portion of the drill collar to the formation occurs because of accumulation of mud or debris between the drill collar and the formation.
Regardless of the original reason for sticking of the drill collar (or drill pipes) in the bore hole, the phenomenon represents a serious and expensive-to-solve problem for the drilling industry. As is well known, when the drill collar is stuck, the actual drilling operation halts. In accordance with usual practice in the art, the workmen at the drilling rig first try to free the stuck drill collars. When the attempts to free the stuck drill collars fail, then the stuck portion is usually severed from the portion of the drill string which is located above it. The stuck portion of the drill string is either abandoned in the bore hole or is retrieved ("fished-out") from the hole by using various retrieval techniques and devices.
Unfortunately from the view point of the drilling industry, accumulation of solid mud or debris between the walls of a drill collar and the formation is usually accelerated whenever rotation or movement of the drill collars is halted. Thus, unless a differentially stuck drill collar is freed promptly, larger and larger portions become hydrostatically pressed against the formation and freeing the assembly becomes progressively more difficult.
Even though the prior art has been well aware of the abovesummarized problem, it has been, by-and-large, unable to provide an effective solution. Severing the free portion of the drill string from the stuck portion and thereafter abandoning the stuck portion (free point and back-off) is not considered an effective solution in this regard. Other attempts to solve the problem include devices which are located at the top of the drill collars and provide repeated, large, axially directed jolts to the drill string. Many times, however, these devices are unable to free the stuck drill string. For these reasons the present invention fills a great need in the prior art.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a device for freeing stuck portions of a drill string, and particularly to provide a device for freeing differentially stuck drill collars.
It is another object of the present invention to provide a device for freeing stuck portions of a drill string, which device can be incorporated into practically all drill strings, and which is actuable for operation whenever the need arises.
The foregoing and other objects and advantages are attained by a device which is mountable intermediately in the drill string, substantially concentrically with the longitudinal axis of the drill string. The device is usually mounted above the drill collars and just below the drill pipes of the drill string. The device includes a first member concentrically mounted with the drill pipes and a second member concentrically mounted with the drill collars. An intermediate member connects the first and second members in a first, "normal" position wherein these members are in a concentric relationship relative to one another. In the dirst position of the first, second and intermediate members rotation of the drill pipe can be transmitted to the drill collars through these members.
The first, second and intermediate members are held together in their first position by a retainer member which is either severed by application of an axially directed pulling force exceeding a predetermined magnitude, or which, after application of the axially directed pulling force no longer holds the first, second and intermediate members in their first, substantially concentric relationship.
The first, second and intermediate members are configured in such a manner that after application of the axially directed pulling force exceeding the predetermined magnitude, the members are disposed in a second, off-center position relative to one another. The first member is mounted to the intermediate member so that both are capable of free rotation relative to the second member.
During normal drilling operations the device of the present invention is not activated. It merely transmits torque from the drill pipes to the drill collars as an ordinary member of the drill string. When the drill collars become stuck, however, the drilling operator at the drilling rig applies the predetermined pulling force to the drill string thereby causing the first member of the device to occupy its off-center position relative to the second member. This enables the first and intermediate members to rotate freely relative to the second member and the stuck drill collars. As the drill pipes are rotated from the surface by the rotary table the eccentrically disposed first member causes a camming, prying action and a vibration which facilitates freeing of the stuck portions of the drill collars.
The features of the present invention can be best understood together with further objects and advantages, by reference to the following description, taken in connection with the accompanying drawings wherein like numerals indicate like parts.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of the device of the present invention mounted to a drill string in a bore hole, the view showing the device during normal drilling operation;
FIG. 2 is a schematic view of the device of the present invention mounted to a drill string in a bore hole, the view showing the device in its position for freeing a stuck portion of the drill string which is disposed below the device;
FIG. 3 is a cross-sectional view of the device in its first position adapted for normal drilling operations, the view being taken on lines 3,3 of FIG. 1;
FIG. 4 is a cross-sectional view of the device of the present invention, the cross-section being taken on lines 4,4 of FIG. 3;
FIG. 5 is a cross-sectional view of the device of the present invention, the cross-section being taken on lines 5,5 of FIG. 3;
FIG. 6 is a cross-sectional view of the device in its second position adapted for freeing a stuck portion of the drill string disposed in the bore hole below the device, the view being taken on lines 6,6 of FIG. 2;
FIG. 7 is a cross-sectional view of the device of the present invention, the view taken on lines 7,7 of FIG. 6;
FIG. 8 is a partial cross-sectional view of a second preferred embodiment of the device of the present invention, the view being analogous to the cross-sectional view shown in FIG. 3;
FIG. 9 is a partial cross-sectional view of a third preferred embodiment of the device of the present invention;
FIG. 10 is another cross-sectional view of the third preferred embodiment of the device of the present invention, the cross-section being taken on lines 10,10 of FIG. 9;
FIG. 11 is a partial cross-sectional view of a fourth preferred embodiment of the device of the present invention, and
FIG. 12 is a schematic view showing the geometry of the device of the present invention when it is used to free a stuck portion of the drill string.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following specification taken in conjunction with the drawings sets forth the preferred embodiments of the present invention. The embodiments of the invention disclosed herein are the best modes contemplated by the inventor for carrying out his invention in a commercial environment, although it should be understood that various modifications can be accomplished within the parameters of the present invention.
Referring now to the drawing Figures, and particularly to the cross-sectional view of FIG. 3, a first preferred embodiment 20 of the stuck drill collar freeing or releasing device of the present invention is disclosed. As is shown on FIGS. 1 and 2, the device of the present invention is incorporated in the drill string 22 which is disposed in a nominally vertical bore hole 24 drilled in a subterranean formation 26. The drill string 22 includes a plurality of drill pipes 28 attached to one another in the manner customary in the drilling industry. and a bottom hole assembly 30 which is disposed below the drill pipes 28. The bottom hole assembly 30 includes a plurality of drill collars 32 and a drilling bit 34 disposed at the bottom of the drill string 22. In addition to the above-noted major components, the drill string 22, and particuarly the bottom hole assembly 30 thereof may also include additional components such as various subs (not shown) downhole drilling motors (not shown), mule shoes (not shown) and equipment (not shown) for sensing or recording the direction of the bore hole 24.
As it was noted above in the introductory section of the present application for patent, the drill string 22 is normally rotated by a rotary table (not shown) which is located on the drilling rig (not shown) on the surface. In certain type of drilling operations the power for drilling in the formation is provided by the rotary table (not shown). In some other type of drilling operations the power for drilling is provided by a downhole motor (not shown) driven by drilling mud (not shown) which is continuously pumped downwardly within the hollow interior of the drill string 22, and which flows upwardly between the exterior of the drill string 22 and the walls 35 of the bore hole 24. The rotary table (not shown) however, occasionally rotates the drill string slowly even when a downhole motor is used. This is done to avoid, to the maximum extent possible, differential sticking of any portion of the drill string 22 to the walls 35 of the bore hole 24. The device of the present invention is suitable for freeing stuck sections of the drill string 22 regardless whichever technique is used to power the drilling operation.
As it was further noted in the introductory section of the present application for patent, the drill collar containing bottom hole assembly 30 is the portion of the drill string 22 which is most likely to become differentially stuck. Therefore, the device of the present invention is primarily adapted to be mounted in the drill string 22 above the bottom hole assembly 30 just above the uppermost drill collar 32 and below the lower most drill pipe 28. Such mounting of the device of the present invention is shown in the drawing Figures. It should be kept in mind, however, that the present invention is not so limited in principle, and the device of the present invention can be intermediately mounted in the drill string 22 substantially anywhere.
In accordance with the present invention, the device of the present invention is capable of conducting the flow of drilling mud (not shown) in its interior. In normal operation the device of the present invention acts as a substantially regular, concentrically mounted and disposed member of the drill string 22. The device of the present invention is adapted to be actuable to free stuck portions of the drill string 22, particularly the bottom hole assembly 30, only when the need arises.
Referring now primarily to the cross-sectional view of FIG. 3, the device of the present invention is shown to include a first member 36 which is attached to the lowermost drill pipe 28 by threaded joints conventionally used for joining pieces of downhole drilling equipment. More specifically, the drill pipe 28 includes a male thread 38, and the first member 36 comprises two pieces. A top piece 40 of the first member 36 has a female thread 42 through which the top piece 40 is mounted to the male thread 38 of the drill pipe 28. The top piece 40 also has a male thread 44 on the lower part thereof. A second or lower piece 46 of the first member 36 is threadedly attached to the male thread 44 of the top piece 40. The top piece 40 is hollow to permit circulation of drilling mud (not shown). The hollow interior of the top piece 40 includes a shoulder 48 in which a rim 50 of a retainer member 52 rests. The retainer member 52 is described in more detail below.
The second piece 46 of the first member 36 has a tapered male hexagonal boss 54 at its bottom and an interior hexagonal bore 56 which is at an angle relative to the longitudinal axis of the first member 36 and of the drill string 22. In the herein described first specific embodiment 20 of the device of the present invention, the interior hexagonal bore 56 of the second piece 46 of the first member 36 is machined at an angle of 0.125 inch per longitudinal inch. The second piece 46 of the first member 36 contains, above the interior hexagonal bore 56, a socket or cavity 58 to receive and accomodate an upper retainer collar 60 of an intermediate member or spindle 62 which is described in more detail below.
A second member 64 of the device of the present invention has a female thread 66 at its lowermost portion so it can be fastened to an appropriate cross-over 68. The cross-over 68 is, in turn, threadedly fastened to the uppermost drill collar 32 of the bottom hole assembly 30. The second member 64 incorporates a hexagonal opening or cavity 70 which matches and receives the hexagonal boss 54 of the second piece 46 of the first member 36. The second member 64, like the first member 36, is also hollow to permit circulation of drilling mud (not shown) and to accomodate cables (not shown) and the like which may be utilized for placing electronic sensors (not shown), cameras (not shown) and other equipment (not shown) into the bottom hole assembly 30.
The second member 64 includes a plurality of bearings 72 which, under certain conditions, permit free rotation of the intermediate member or spindle 62 relative to the second member 64. Preferably, the bearings 72 comprise four (4) Timken tapered roller bearings, shown in FIGS. 3, 6 and 8. In accordance with the present invention, the first member 36 always rotates together with the drill pipes 28 to which the first member 36 is attached, and the second member 64 always rotates together with the drill collars 32 to which the second member 64 is attached.
The intermediate member or spindle 62 includes a hexagonal section 74 which matches and is accomodated in the hexagonal bore 56 of the second piece 46 of the first member 36. The hexagonal section 74, well shown on the cross-sectional view of FIG. 4, is machined at the same angle to the longitudinal axis of the device of the present invention as the hexagonal bore 56, so that the spindle 62 is capable of limited sliding motion in the hexagonal bore 56.
A collar or rim 60 is provided in the upper portion of the spindle 62. The collar 60 is disposed in the socket or cavity 58 of the second piece 46 of the first member 36. The collar 60 limits the sliding motion of the spindle 62 in the hexagonal bore 56 by engaging a corresponding shoulder 78 in the bottom of the socket 58. A threaded retainer ring 80 engages the bottom of the spindle 62 just below the bearings 72. As is shown in the drawing Figures, and particularly FIGS. 3 and 6, the spindle or intermediate member 62 is disposed within the interiors of the first member 36 and the second member 64.
The retainer member 52 is a hollow tubular body which is disposed within the interior of the spindle 62. Consequently, inner walls 82 of the retainer member 52 comprise a conduit for the drilling mud (not shown). The function of the retainer member 52 is to normally hold the first member 36, the second member 64 and the intermediate member or spindle 62 together as is shown on FIG. 3. For this purpose the rim or collar 50 of the retainer member 52 is engaged by the shoulder 48 formed in the top piece 40 of the first member 36, and the bottom of the retainer member is engaged by a second threaded ring 84. The second threaded ring 84 is disposed below the first threaded ring 80, as is shown in FIG. 3. In the alternative preferred embodiment of the device of the present invention shown on FIG. 8, the retainer member 52 is threadedly engaged in the spindle 62, and therefore the second retainer ring 84 is not needed.
As an important feature of the present invention the retainer member 52 is designed to retain the first member 36, the second member 64 and the intermediate member 62 in their first relative positioning only until an axial force exceeding a predetermined magnitude is applied to the device of the present invention. Therefore, the retainer member 52 includes a weak, thin walled section 85 which is designed to break when the axial force exceeding the predetermined magnitude is applied. The breaking strength of the weak, thin walled section 85 is approximatey two to three times the weight of the bottom hole assembly 30. When the drill collars are of eight (8) inch diameter and the bottom hole assembly 30 is of conventional length, the breaking strength of the thin walled section 85 is typically and approximately 75,000 lbs.
Operation of the device of the present invention should be readily apparent to those skilled in the art from the foregoing description taken in conjunction with the drawing Figures. When the retainer member 52 is intact, as is shown on FIG. 3, the hexagonal boss 54 of the second piece 46 of the first member 36 engages the corresponding hexagonal cavity 70 of the second member 64. The intermediate member or spindle 62 is disposed in the position shown on FIG. 3, and the spindle 62 and the second member 64 are both rotated by the first member 36. The first member 36, the second member 64 and the spindle 62 are disposed concentrically with one another and with the general longitudinal axis of the drill string 22. In this first operative position of the device of the present invention, the device is "transparent" from the viewpoint of the drilling operator (not shown) in the sense that it does not interfere with normal drilling operations.
FIGS. 2, 6 and 7 show the device of the present invention in a second operative position after the device was actuated by the driling operator (not shown) to free the stuck bottom hole assembly 30. To accomplish this, the drilling operator (not shown) lifts the drill string 22 at the drilling rig (not shown) with blocks (not shown) or the like until the predetermined breaking force of the weak section 85 of the retainer member 52 is exceeded. It should be readily understood by those skilled in the art, that unless a portion of the drill string 22 disposed below the device of the present invention is stuck, the breaking force necessary to rupture the weak section 85 of the retainer member 52 can not be attained by lifting the drill string 22. This, of course, serves as a safe guard during normal drilling operations.
Once the retainer member 52 is ruptured, the first member 36 and the drill string disposed above the first member 36 are shifted upwardly relative to the intermediate member of spindle 62 and relative to the second member 64 and the stuck bottom hole assembly 30. During this movement the hexagonal section 74 of the spindle 62 slides in the hexagonal bore 56 until the collar 60 of the spindle 62 interferes with the bottom of the socket 58, as is shown on FIG. 6.
Because the hexagonal bore 56 is at an angle relative to the longitudinal axis of the device of the present invention, in this second operative position of the device of the present invention the first member 36 is off-center relative to the second member 64 and relative to the stuck bottom hole assembly 30. This is shown on FIG. 6 where the longitudinal center line or axis of the device of the present invention is shown with a dotted line and bears the reference numeral 86. In the second operative position of the device of the present invention, the hexagonal boss 54 of the first member 36 is disengaged from the matching hexagonal cavity 70 of the second member 64. Therefore, the second member 64 is no longer rotated by the first member 36. Instead, the bearings 72 permit free rotation of the spindle 62 in the stationary second member 64.
In accordance with the present invention, in an effort to free the stuck bottom hole assembly 30, the drilling operator (not shown) slowly rotates the drill string with the rotary table (not shown) in the second operative position of the device. The schematic view of FIG. 12 illustrates the effect of this rotation. Because the rotating first member 36 is off-center relative to the stuck portion, during each revolution the first member 36 is likely to come into contact with the formation 26 to provide a jolt substantially at a right angle to the nominal longitudinal axis of the drill string 22. This is a camming or prying action which has not been accomplished in any known working device of the prior art.
In addition to the horizontal impulse and camming action, the off-center positioning of the rotating mass also causes a vertical impulse in the stuck drill string. These effects are likely to cause vibration and resonance in the stuck portion in the horizontal direction or in the vertical direction, or both, which help to free the stuck portion. In order to attain optimal frequency of vibration for freeing the stuck portion, (horizontal or vertical resonance) the drilling operator (not shown) may gradually adjust the speed of rotation of the rotary table (not shown).
Once the stuck portion is freed, the entire drill string 22 may be removed from the bore hole 24. Alternatively, the upper portion of the drill string may be slowly lowered while the rotary table (not shown) is carefully rotated, to re-seat the hexagonal boss 54 in the matching cavity 70 of the second member 64. Then, the drilling operation may continue because the device of the present invention is again "transparent" for the purposes of ordinary drilling.
Several modifications of the device of the present invention are apparent from the foregoing description. For example, instead of hexagonal bosses, bores and matching cavities, other multifaceted bosses, bores and cavities may be used. Alternatively, bosses, bores and cavities of cylindrical cross-section having appropriate splines and spline receiving slots, respectively, may be incorporated in the device of the preesnt invention.
FIGS. 9 and 10 illustrate a third preferred embodiment of the device of the present invention. In this embodiment the offcenter positioning of the first member 36 in the second operative position is accomplished by providing spiral splines 88 in the spindle 62 and matching spiral spline receiving slots 90 in the spindle receiving cavity 70 of the first member 36. The splines 88 and the spline receiving slots 90 are off-set relative to the longitudinal axis of the device, so that unless the spindle 62 is fully inserted into the cavity 70 , as shown in FIG. 9, the first member 36 and the second member 64 are off-center relative to one another.
FIG. 11 illustrates a fourth preferred embodiment wherein the first member 36 is maintained in the second member 64 by a spring biased ball 92 which is held in a suitable ball seat 94. In this embodiment, there is no retainer member 52. Application of the predetermined, or larger, axial force unseats the ball 92 from the ball seat 94 and permits the device to shift into its second operative position.
Generally speaking, the device of the present invention is manufactured from steels of the type which are normally used for construction of downhole drilling equipment. The device of the present invention is typically and approximatey four (4) feet long and weighs approximately 600 lbs. The device of the present invention can, of course, be manufactured to fit eight (8) inch diameter or other drill collars and various size drill pipes. The device of the present invention is advantageously incorporated in every drill string whenever the possibility for differential sticking exists.
The breaking strength of the weak walled section 85 of the retainer member 52, or the spring bias of the alternative embodiment shown in FIG. 10 may be specifically adjusted for each drilling operation to fit the anticipated drilling conditions and the weight of the bottom hole assembly. When the weak walled retainer member 52 of the first preferred embodiment 20 is used, it is advantageous to manufacture the retainer member 52 from a lower strength steel than the rest of the device. This renders the dimensions of the weak walled section 85 somewhat less critical and therefore simplifies machining of the weak walled section 85.
Several additional modifications of the device of the present invention may become readily apparent to those skilled in the art in light of the foregoing disclosure. Therefore, the scope of the present invention should be interpreted solely from the following claims. | A device is disclosed which is to be incorporated into a drill string used for drilling in subterranean formations. The device includes a first member concentrically mounted with drill pipes disposed above the device and a second member concentrically mounted with drill collars or drill pipes disposed below the device. An intermediate member connects the first and second members and a retainer member maintains the device in its first operative position wherein the entire device is concentric with the longitudinal axis of the drill string. In the first operative position of the device rotation can be transmitted from the first member to the second member and the device acts as an ordinary member of the drill string. The first, second and intermediate members are configured to be capable of occupying a second operative position relative to one another wherein the first member is off-center relative to the second member and wherein the first member does not rotate the second member. The device is shifted into the second operative position by an axial force exceeding a predetermined level, which force breaks the retainer member or renders it incapable of holding the device in the first operative position. Rotation of the drill string from the surface causes a camming action and vibration in the second operative position of the device which helps to free stuck portions of the drill string. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The underlying concepts, but not necessarily the language, of the following cases are incorporated by reference:
[0002] (1) U.S. provisional application No. 61/207,467; and
[0003] (2) U.S. provisional application No. 61/273,814.
[0000] If there are any contradictions or inconsistencies in language between this application and one or more of the cases that have been incorporated by reference that might affect the interpretation of the claims in this case, the claims in this case should be interpreted to be consistent with the language in this case.
[0004] This case claims benefit of the following provisional applications:
[0005] (1) U.S. provisional application No. 61/207,467; and
[0006] (2) U.S. provisional application No. 61/273,814.
[0007] This case is a Continuation-in-Part and claims priority of co-pending U.S. case No. 12/535,768 titled “Multiple-Resonator Antenna” and filed on Aug. 5, 2009.
FIELD OF THE INVENTION
[0008] The present invention relates to antenna design for radio communication in general, and, more particularly, to antenna design for Radio-Frequency IDentification (RFID) systems.
BACKGROUND OF THE INVENTION
[0009] Radio communication systems have existed for over a century. During this period of time, antenna designers have generated a wide variety of antenna designs with the goal of achieving good performance in a variety of operating conditions.
[0010] Generally, the goal of the antenna designer when designing, for example, a receiving antenna, is to maximize power transfer between an electromagnetic signal incident on the antenna, and the resulting electrical signal generated by the antenna. The higher the power transfer, the higher the received signal-to-noise ratio, which usually results in better receiver performance.
[0011] Also, traditionally, radio receivers have comprised electronic circuitry and a separate receiving antenna interconnected to one another through a suitable cable connection. In such systems, antenna designers must consider the distorting influence of the cable connection and the electronic circuitry on the electromagnetic behavior of the antenna.
[0012] More recently, with the advent of small radio systems based on integrated circuit technology, it has become possible to make so-called Radio-Frequency IDentification (RFID) systems, wherein an entire radio receiver is housed in a package much smaller than the receiving antenna. In such systems, the almost-complete elimination of the distorting influence of the cable connection and the electronic circuitry enables novel antenna designs.
[0013] So-called passive RFID receivers can be much smaller than the receiving antenna in part because they do not require a power supply. Power to operate the receiver is derived from the received radio signal itself. The signal generated by the receiving antenna is rectified by one or more diodes to yield a direct-current (DC) voltage that is used to power the receiver.
[0014] Ideal diodes are perfect conductors when a forward voltage is applied and are perfect insulators when a reverse voltage is applied. Real diodes only approximate this behavior. In particular, real diodes require a minimum forward voltage before becoming good conductors. Accordingly, the signal generated by the receiving antenna, must have a voltage higher than the minimum required by the diodes, before a DC voltage becomes available to power the RFID receiver.
[0015] So, in contrast with traditional antenna design, the goal for the design of passive-RFID-receiver antennas is to maximize not the received-signal power, but rather the received-signal voltage.
[0016] It is well known in the art that antennas are reciprocal devices, meaning that an antenna that is used as a transmitting antenna can also be used as a receiving antenna, and vice versa. Furthermore, there is a one-to-one correspondence between the behavior of an antenna used as a receiving antenna and the behavior of the same antenna used as a transmitting antenna. This property of antennas is known in the art as “reciprocity.”
[0017] An antenna used as a transmitting antenna accepts an electrical signal applied at an input port and produces a transmitted electromagnetic signal that propagates through three-dimensional space. It is well known in the art how to represent such a transmitted electromagnetic signal as a vector in a vector space, for example, as a superposition of spherical harmonics. The behavior of a transmitting antenna at a given frequency can be fully characterized by reporting, for example, the spherical-harmonic components of the transmitted electromagnetic signal that it generates in response to a test electrical signal at that frequency that is applied to the antenna's input port.
[0018] Such a characterization can be used to derive, unambiguously, the behavior of the same antenna when it is used as a receiving antenna. In this case, the input port becomes an output port that generates an output electrical signal in response to an incident electromagnetic signal propagating through three-dimensional space. The incident electromagnetic signal can be specified by, for example, by specifying its spherical-harmonic components. The resulting electrical signal can then be derived through a scalar product with the spherical-harmonic components of the transmitted electromagnetic signal at the same frequency, as is well known in the art.
[0019] A consequence of reciprocity is that an antenna can be fully characterized in terms of its properties as either a transmitting antenna or as a receiving antenna. A full characterization of an antenna when used in one mode (transmitting or receiving) uniquely and unambiguously defines the properties of the antenna when used in the other mode.
[0020] For example, in order to understand or measure the radiation pattern of an antenna it is frequently easier to feed an electric signal into the antenna and then observe the electromagnetic field generated by the antenna. This task can be performed experimentally or computationally. The radiation pattern of the antenna that is obtained through this method also applies when the antenna is used as a receiving antenna. Hereinafter, antennas will be interchangeably referred to as receiving or transmitting, and their properties will be discussed as they apply to either transmission or reception, as convenient to achieve clarity. It will be clear to those skilled in the art how to apply what is said about an antenna used in one mode (receiving or transmitting) to the same antenna used in the other mode.
[0021] FIG. 1 depicts monopole antenna 100 in accordance with the prior art. Monopole antenna 100 comprises monopole 110 , ground plane 120 and co-axial cable connection 130 . Monopole antenna 100 is a very common type of antenna and is representative of how many antennas operate. When an electrical signal is applied to co-axial cable connection 130 , an electric field appears between monopole 110 and ground plane 120 . If the electrical signal has a frequency at or near the so-called “resonant” frequency of the antenna, a large fraction of the power of the electrical signal is converted into an electromagnetic signal that is radiated by the antenna. If the electrical signal has a frequency that is substantially different from the resonant frequency of the antenna, a relatively small fraction of the signal's power is radiated; most of the power is reflected back into the co-axial cable connection.
[0022] In principle, it is possible to make an antenna that radiates efficiently at many frequencies, without exhibiting a band of resonance. In practice, it is difficult to make such antennas, and resonant structures (hereinafter also referred to as “resonators”) are commonly used to make antennas that radiate efficiently.
[0023] FIG. 2 depicts resonant structure 200 , which is an example of a type of resonant structure commonly used to make antennas in the prior art. Resonant structure 200 comprises a length of wire 240 bent in the shape of the letter U, with an input-output port 220 comprising connection points 230 - 1 and 230 - 2 . As depicted in FIG. 2 , the two connection points are attached to the two ends of the wire.
[0024] The frequency of resonance of resonant structure 200 depends on its length. The structure can be modeled as a twin-lead transmission line 210 with a short at one end (i.e., the end opposite input-output port 220 ). The structure is resonant at a frequency for which the length of the transmission line is about one quarter of a wavelength. The range of frequencies near the resonant frequency over which the resonant structure exhibits acceptably good performance is known as the “band of resonance.”
[0025] Resonant structure 200 exhibits resonance in a manner similar to monopole antenna 100 . Near the resonant frequency, the electromagnetic fields generated by the voltages and currents on wire 240 become stronger, and a larger fraction of the power of an electrical signal applied to input-output port 220 is radiated as an electromagnetic signal. Accordingly, resonant structures that exhibit this behavior are referred to as “electromagnetically-resonant.”
[0026] FIG. 3 depicts folded-dipole antenna 300 , which is an example of a common type of antenna in the prior art. Folded-dipole antenna 300 can be modeled as being composed of two instances of resonant structure 200 connected in series. When used as a transmitting antenna, an electrical signal is applied through balanced transmission line 320 .
[0027] Although folded-dipole antenna 300 can be modeled as being composed of two instances of resonant structure 200 connected in series, the signal that it generates when used as a receiving antenna is not the sum of the signals that each instance of resonant structure 200 would generate if used by itself because of the mutual coupling between the two instances of resonant structure 200 .
[0028] FIG. 4 depicts antenna-with-load-element 400 , which is an example of a type of antenna in the prior art for RFID systems known as RFID tags. Antenna-with-load-element 400 comprises: conductive sheets 410 - 1 , and 410 - 2 , electrical connection 420 , connection points 440 - 1 and 440 - 2 , and load element 430 , interrelated as shown.
[0029] Conductive sheets 410 - 1 and 410 - 2 , together with electrical connection 420 , form resonant structure 450 . Load element 430 receives the signal generated by resonant structure 450 through connection points 440 - 1 and 440 - 2 . When used to implement an RFID tag, load element 430 is small relatively to the size of conductive sheets 410 - 1 and 410 - 2 .
[0030] To implement an RFID tag, load element 430 acts as both a receiver and a transmitter. In particular, in a passive RFID tag, transmission is accomplished through a technique known as “modulated backscatter” wherein load element 430 controls the impedance that it presents to the received signal. Modulated backscatter is based on the fact that, in any radio receiver, a portion of the electromagnetic signal incident on the receiving antenna is reflected. The amplitude and phase of the reflected signal depend on the impedance connected to the antenna port, so that load element 430 modulates the reflected signal by controlling its own impedance.
SUMMARY OF THE INVENTION
[0031] Embodiments of the present invention comprise a pair of resonant structures implemented as resonant cavities. Cavities are realized by interconnecting sheets of conductive material such as, for example, metal foil. Two cavities are combined to achieve an antenna structure that, when used as a receiving antenna, has a source impedance that is higher than prior-art antennas. For a given received signal strength, the higher source impedance yields a higher voltage at the antenna output port, resulting in a longer distance of operation for RFID tags based on the present invention.
[0032] An embodiment of the present invention comprises a ribbon of conductive material, such as metal foil, wherein the two ends of the ribbon are folded over the middle part of the ribbon. Between each folded end of the ribbon and the middle part of the ribbon there is a layer of supporting material that supports the ribbon and maintains the folded end of the ribbon at a fixed distance from the middle part of the ribbon. The volume of space between one end of the ribbon and the middle part of the ribbon, which is occupied by the supporting material, forms one electromagnetically-resonant cavity. The supporting material also acts as dielectric.
[0033] A load element is connected between the two folded ends of the ribbon to make an RFID tag. The folded ribbon is the tag's antenna; it has a higher impedance than prior-art antennas for RFID tags, with the result that a higher voltage is generated across the load element.
[0034] For situations where an RFID tag is used near a large metal object, embodiments of the present invention comprise an additional sheet of conductive material, referred to as a “reflector.” For embodiments implemented as a folded ribbon, the reflector sheet is placed parallel to the middle part of the ribbon, on the side opposite the folded ends. A layer of supporting material is between the reflector and the middle part of the ribbon and serves to maintain a fixed distance between them. The presence of the reflector reduces the disruption of tag performance caused by large metal objects in the vicinity of the tag.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1 depicts a monopole antenna in the prior art.
[0036] FIG. 2 depicts a resonant structure in the prior art.
[0037] FIG. 3 depicts a folded-dipole antenna in the prior art.
[0038] FIG. 4 depicts an example of a type of antenna in the prior art for RFID tags.
[0039] FIG. 5 depicts a dual-cavity antenna with a load element in accordance with a first illustrative embodiment of the present invention.
[0040] FIG. 6 depicts a dual-cavity antenna with non-equal cavities in accordance with a second illustrative embodiment of the present invention.
[0041] FIG. 7 depicts a dual-cavity antenna with a reflector in accordance with a third illustrative embodiment of the present invention.
[0042] FIG. 8 depicts a dual-cavity antenna with a dielectric in accordance with a fourth illustrative embodiment of the present invention.
[0043] FIG. 9 depicts a dual-cavity antenna with multiple dielectrics and a reflector in accordance with a fifth illustrative embodiment of the present invention.
[0044] FIG. 10 depicts a dual-cavity antenna with delay elements in accordance with a sixth illustrative embodiment of the present invention.
DETAILED DESCRIPTION
[0045] FIG. 5 depicts dual-cavity-antenna-with-load-element 500 in accordance with a first illustrative embodiment of the present invention. Dual-cavity-antenna-with-load-element 500 comprises: conductive ribbon 510 , load element 520 , and connection points 530 - 1 and 530 - 2 interrelated as shown. In particular, the two ends, 540 - 1 and 540 - 2 , of conductive ribbon 510 , are folded over the middle part 550 of conductive ribbon 510 and they are on the same side of the middle part 550 of conductive ribbon 510 . The two folded ends 540 - 1 and 540 - 2 do not touch one another. Connection points 530 - 1 and 530 - 2 are on the two folded ends, 540 - 1 and 540 - 2 , of conductive ribbon 510 .
[0046] Each of the two folded ends 540 - 1 and 540 - 2 forms a resonant cavity together with the middle part 550 of conductive ribbon 510 . The two cavities are electrically connected together via the shared middle part 550 of conductive ribbon 510 . Compared to prior-art folded-dipole antenna 300 , dual-cavity antenna with load element 500 has a higher impedance. In traditional radio systems, the higher impedance is not an advantage—indeed, in many traditional radio systems it is a disadvantage—but the higher impedance is advantageous in passive RFID tags. The use of a conductive ribbon to form two cavities, instead of using two resonant structures formed by a wire, is a salient difference between folded-dipole antenna 300 and dual-cavity antenna with load element 500 ; this difference gives the latter antenna the advantageous higher impedance. The other illustrative embodiment of the present invention set forth in this disclosure also provide the advantage of a higher impedance.
[0047] Although the two cavities formed by the two folded ends 540 - 1 and 540 - 2 are depicted in FIG. 5 as equal to one another, it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention wherein the two cavities are different.
[0048] Although connection points 540 - 1 and 540 - 2 are depicted in FIG. 5 as being placed near the center of folded ends of ribbon 540 - 1 and 540 - 2 , respectively, it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention wherein the connection points are in different places. For example and without limitation, connection points 540 - 1 and 540 - 2 can be near corners of folded ends of ribbon 540 - 1 and 540 - 2 .
[0049] Although connection points 540 - 1 and 540 - 2 are depicted in FIG. 5 as direct electrical connections such as are known in the art as “ohmic” connections, it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention wherein the connection points are realized differently. For example and without limitation, connection points 540 - 1 and 540 - 2 can comprise capacitors or inductors or more complex impedance-matching networks.
[0050] Although the portions of conductive ribbon 510 wherein the folds occur are depicted as semicircular in shape, it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention with folds having different shapes. For example, and without limitation, FIG. 8 below depicts an alternative embodiment of the present invention that can be implemented by folding a conductive ribbon in a different manner.
[0051] FIG. 6 depicts dual-cavity-antenna-with-non-equal-cavities 600 in accordance with a second illustrative embodiment of the present invention wherein the two cavities are not equal. As with the first illustrative embodiment, this antenna comprises a conductive ribbon 610 , whose ends, 620 and 630 , are folded over the middle part 640 of the ribbon. However, folded end 630 is longer than folded end 620 , and folded end 630 is at a distance 650 from middle part of ribbon 640 that is less than the distance 660 between the shorter folded end of the ribbon 620 and the middle part of the ribbon 640 .
[0052] For the purpose of visual clarity, FIG. 6 does not show connection points or a load element. Such elements in the second illustrative embodiment are identical to the corresponding elements in the first illustrative embodiment and should be understood to be present even though they are not depicted in FIG. 6 . It will be clear to those skilled in the art, after looking at FIG. 5 and reading this disclosure, how to place connection points and how to attach a load element to dual-cavity antenna with non-equal cavities 600 in a manner similar to the manner shown in FIG. 5 for dual-cavity antenna with load element 500 . Hereinafter, for the purpose of visual clarity, other figures that depict alternative embodiments of the present invention will also not explicitly show connection points or a load element. It will be understood that connection points and a load element are also present in all such embodiments, and it will be clear to those skilled in the art, after looking at FIG. 5 and reading this disclosure, how to place connection points and how to attach a load element, in such embodiments, in a manner similar to the manner shown in FIG. 5 for dual-cavity antenna with load element 500 .
[0053] Although, in FIG. 6 , the two cavities differ from one another because the lengths of folded ends 620 and 630 are different, and because distances 650 and 660 are different, it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention wherein the two cavities differ from one another in other ways. For example, and without limitation, the two cavities can differ by:
i. having different lengths, ii. having different widths, iii. the two folded ends having different distances from the middle part of the ribbon, iv. being made of different conductive materials, v. having different shapes, vi. comprising different dielectric materials, vii. comprising different amounts of dielectric materials, viii. comprising different combinations of multiple dielectric materials, ix. having different corners, x. having differently-finished edges, or xi. a combination of i, ii, iii, iv, v, vi, vii, viii, ix, or x.
[0065] FIG. 7 depicts dual-cavity-antenna-with-reflector 700 in accordance with a third illustrative embodiment of the present invention. Dual-cavity-antenna-with-reflector 700 comprises conductive ribbon 710 and conductive reflector sheet 720 . Conductive ribbon 710 implements a dual-cavity antenna in accordance with the first illustrative embodiment or in accordance with the second illustrative embodiment set forth above.
[0066] Although FIG. 7 shows conductive ribbon 710 as having the same shape as conductive ribbon 510 as depicted in FIG. 5 , it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of a dual-cavity antenna with reflector in accordance with the present invention wherein conductive ribbon 710 has the same shape as conductive ribbon 610 as depicted in FIG. 6 . Furthermore, it will also be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of a dual-cavity antenna with reflector in accordance with the present invention wherein conductive ribbon 710 is replaced by one of the alternative embodiments of a dual-cavity antenna according set forth in this disclosure. For example, and without limitation, one such embodiment of a dual-cavity antenna with reflector is depicted in FIG. 9 below.
[0067] Although conductive reflector sheet 720 is depicted as a thin sheet, as might be implemented with metal foil, that extends slightly beyond the outline of conductive ribbon 710 , it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention wherein conductive reflector sheet 720 is realized differently. For example and without limitation, conductive reflector sheet can be:
i. much larger than conductive ribbon 710 , ii. a solid block of conductive material, iii. part of a metal structure that also provides mechanical support, iv. part of the housing of an RFID system, or v. a combination of i, ii, iii, or iv.
[0073] FIG. 8 depicts dual-cavity-antenna-with-dielectric 800 in accordance with a fourth illustrative embodiment of the present invention. Dual-cavity-antenna-with-dielectric 800 comprises: conductive sheets 810 - 1 , 810 - 2 , and 810 - 3 , electrical connections 820 - 1 and 820 - 2 , and dielectric material 830 , interrelated as shown.
[0074] Electrical connections 820 - 1 and 820 - 2 perform the same functions as the curved portions of conductive ribbon 510 in the first illustrative embodiment of the present invention. Conductive sheet 810 - 1 performs the same function as middle part of ribbon 550 in the first illustrative embodiment of the present invention. Conductive sheets 810 - 2 and 810 - 3 performs the same functions as folded ends of ribbon 540 - 1 and 540 - 2 in the first illustrative embodiment of the present invention. In particular, conductive sheets 810 - 2 and 810 - 3 form two resonant cavities, respectively, together with conductive sheet 810 - 1 .
[0075] Although the combination of conductive sheets 810 - 1 , 810 - 2 , and 810 - 3 , and electrical connections 820 - 1 and 820 - 2 can be realized by folding a ribbon of conductive material similar to conductive ribbon 510 with sharp bends around dielectric material 830 , it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention that are realized in a different manner. For example and without limitation, electrical connections 820 - 1 and 820 - 2 can be realized as:
i. single wires or multiple wires, ii. portions of sheet material bent in different shapes, iii. single or multiple connections at single or multiple points along the edges of the interconnected sheets, iv. separate sheets of conductor formed by a stamping process and press fitted together as desired v. solder joints, screws, pins, or other electrically conductive fasteners, vi. plated-through via holes, vii. a combination of i, ii, iii, iv, v, or vi
Furthermore, the electrical connections can extend over larger or smaller sections of one or more edges of the conductive sheets.
[0083] Although conductive sheets and conductive ribbons are depicted in the figures of this disclosure as solid sheets of electrically conductive material such as, for example, metal foil, it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention wherein the conductive sheets and conductive ribbons are realized differently. For example, and without limitation, a conductive sheets or a conductive ribbon can:
i. be a grid of wires, or a mesh, ii. be made of any conductive materials such as metals (e.g., copper, aluminum) or, for example, conductive ink, or conductive paint, iii. be perforated with holes arranged at random or in a regular pattern, iv. be a printed circuit board with one or more interconnection layers, v. comprise notches or jagged edges, vi. have an uneven or rough surface with bumps or lumps, vii. comprise electronic components, such as, for example, resistors, capacitors or integrated circuits, viii. comprise mechanical fasteners such as, for example, screws, nuts, or rivets, ix. comprise solder joints, welds or other electrical or mechanical joints, x. be an array of parallel wires substantially parallel to the prevailing direction of electrical currents within the sheet or ribbon. xi. be a combination of i, ii, iii, iv, v, vi, vii, viii, ix, or x.
[0095] Although dielectric material 830 is shown in FIG. 8 as occupying most of the volume between sheet 810 - 1 and sheets 810 - 2 and 810 - 3 , it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention wherein only none of the volume or only a portion of the volume is occupied by dielectric material, or dielectric material extends beyond the volume between the conductive sheets. It will also be clear to those skilled in the art, after reading this disclosure, how to make and use variants of the illustrative embodiments set forth in this disclosure wherein part or all of the volume of space within one or both of the cavities comprises one or more dielectric materials.
[0096] Many different dielectric materials are known in the art for making resonant structures. For example, and without limitation, dielectric material 830 can be acetate, ABS (Acrylonitrile Butadiene Styrene) of various densities, polyphenylsulphone, polyethersulfone, polysulfone, PETG (Polyethylene Terephthalate Glycol), polycarbonate, teflon, polystyrene, difunctional epoxy resin (FR4), epoxy glass, or polyethylene.
[0097] FIG. 9 depicts dual-cavity-antenna-with-multiple-dielectrics-and-reflector 900 in accordance with a fifth illustrative embodiment of the present invention. Dual-cavity-antenna-with-multiple-dielectrics-and-reflector 900 comprises: conductive sheets 810 - 1 , 810 - 2 , and 810 - 3 , electrical connections 820 - 1 and 820 - 2 , conductive reflector sheet 720 , and dielectric materials 930 - 1 , 930 - 2 , and 930 - 3 , interrelated as shown.
[0098] Conductive sheets 810 - 1 , 810 - 2 , and 810 - 3 , electrical connections 820 - 1 and 820 - 2 are identical to conductive sheets 810 - 1 , 810 - 2 , and 810 - 3 , electrical connections 820 - 1 and 820 - 2 in FIG. 8 , respectively. Conductive reflector sheet 720 is identical to conductive sheet 720 in FIG. 7 and it provides the same advantage as in the illustrative embodiment depicted in FIG. 7 .
[0099] In this fifth illustrative embodiment of the present invention, the volume of space inside the two cavities is occupied by two layers of different dielectric materials, 930 - 1 and 930 - 2 . The volume of space between conductive reflector 720 and conductive sheet 810 - 1 is occupied by dielectric material 930 - 3 . It will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention wherein the volumes of space described in this paragraph are occupied by one or more dielectric materials arranged in one or more layers or in other geometric arrangements.
[0100] FIG. 10 depicts dual-cavity-antenna-with-delay-elements 1000 in accordance with a sixth illustrative embodiment of the present invention. Dual-cavity-antenna-with-delay-elements 1000 comprises: conductive sheets 810 - 1 , 810 - 2 , and 810 - 3 , electrical connections 820 - 1 and 820 - 2 , dielectric material 830 , load element 520 , and delay elements 1010 - 1 and 1010 - 2 , interrelated as shown.
[0101] Conductive sheets 810 - 1 , 810 - 2 , and 810 - 3 , electrical connections 820 - 1 and 820 - 2 and dielectric material 830 are identical to conductive sheets 810 - 1 , 810 - 2 , and 810 - 3 , electrical connections 820 - 1 and 820 - 2 and dielectric material 830 in FIG. 8 , respectively. Load element 520 is identical to load element 520 in FIG. 5 .
[0102] The salient difference between this illustrative embodiment and the previous illustrative embodiments is the way in which load element 520 is connected to conductive sheets 810 - 2 and 810 - 3 . It is well known in the art how to make a delay element using a so-called “serpentine” structure, sometimes also referred-to as a “meandering” structure. Such a structure is depicted in FIG. 10 as implementing delay elements 1010 - 1 and 1010 - 2 , and can be regarded as having an electrical behavior similar to an inductor or similar to a delay line. By connecting load element 520 through one or two such delay elements, it is possible to reduce the length of one or both resonant cavities without an increase in the resonant frequency. This is advantageous because, in the absence of such delay elements, a reduction in the size of a resonant cavity, if other cavity parameters are kept unchanged, is generally accompanied by an increase in the cavity's resonant frequency. In an alternative embodiment of the present invention, one or both of delay elements 1010 - 1 and 1010 - 2 can be serpentine ribbon structures with electric-field couplings to conductive sheets 810 - 2 or 810 - 3 , respectively.
[0103] Although this disclosure sets forth embodiments of the present invention as applicable for implementing RFID systems, it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention that are applicable to other types of radio-communication systems. For example, and without limitation, a radio receiver or transmitter characterized by a high input or output impedance can advantageously utilize an antenna in accordance with an embodiment of the present invention.
[0104] It is to be understood that this disclosure teaches just one or more examples of one or more illustrative embodiments, and that many variations of the invention can easily be devised by those skilled in the art after reading this disclosure, and that the scope of the present invention is to be determined by the following claims. | An antenna for a Radio-Frequency IDentification (RFID) system is disclosed that comprises a pair of resonant cavities. The antenna is realized by folding the ends of a ribbon of conductive material, such as metal foil, over the middle part of the ribbon. The antenna generates a higher voltage than prior-art antennas used in RFID systems, and it makes possible RFID systems with an improved range. In an alternative embodiment, the antenna comprises a reflector that enables the RFID system to better tolerate the presence of nearby metal objects. | 7 |
BACKGROUND OF THE INVENTION
[0001] The art of the present invention relates to wheel chocks in general and more particularly to a wheel chock and method of use having one or more rollers or dollies and an extending handle or arm which allows a user to easily place the chock behind a wheel without the usual bending, stooping, or kneeling required with prior art chock devices. The art of the present invention is especially useful for persons having disabilities or other ailments which limit their ability to bend, stoop, or kneel.
[0002] Wheel chocks (i.e. chocks) are generally wedge shaped structures of a sturdy (and generally heavy) material which are typically placed behind one or more vehicle's wheels in order to prevent accidental vehicle movement and promote safety. The bottom surface often has a coating or is manufactured from a material that enhances the grip with the pavement, ground, or floor beneath the chock. The coefficient of static friction of the bottom surface dictates that if the chock is of a greater mass, the force required to slip the chock out of position will be greater. (i.e. the greater the chock mass, the less chance of slippage and undesired vehicle movement) For ease of removal, the prior art often utilizes a rope tied to the chock which may be pulled to remove the chock. Often the prior art utilizes a concave profile on the wheel contacting surface of the wedge in order to contour to the wheel and increase the force necessary to overrun the chock.
[0003] Wheel chocks are regularly utilized during the loading and unloading of trucks and tractor-trailers. The sheer weight of the aforesaid vehicles requires that the chock be manufactured from a durable and generally heavy material in order to minimize the probability of chock deformation and vehicle movement. Unfortunately, wheel chocks having the required durability are often so heavy that they cannot be easily placed under or mated with the wheels of a vehicle by a single user without undue stresses placed upon the user.
[0004] The prior art attempts to address this issue in U.S. Pat. No. 6,390,245 B1 issued to Metz on May 21, 2002. Metz places a handle onto a lightweight honeycomb material chock in order to facilitate placement of the chock. The art of Metz is designed to be lifted by the user and, by necessity, requires that the chock be of a lightweight material. Unfortunately, a lightweight chock is generally not as sturdy or as likely to inhibit the vehicle from moving.
[0005] The present art represents a heavy and durable wheel chock having a handle and roller assembly which allows the user to easily roll the chock into a mating position under a vehicle wheel and remove the chock when required. The present art does not require the user to physically lift the chock during use. This allows the chock to be manufactured a heavy and durable material and thereby provide the optimum benefits.
[0006] Accordingly, it is an object of the present invention to provide a wheel chock having a roller assist which maximizes chock strength, weight, and retention ability while minimizing user inconvenience.
[0007] Another object of the present invention is to provide a wheel chock having a roller assist with a roller assembly and handle which allows a user to easily place the chock without bending, stooping, or kneeling.
[0008] A further object of the present invention is to provide a wheel chock having a roller assist which also has a chain or cable attachment assembly for securely attaching the chock to a building or other non-movable structure in order to prevent theft.
SUMMARY OF THE INVENTION
[0009] In its preferred form, the art of the present invention represents a chock in the form of a generally wedge shaped structure with a wheel contacting surface, a bottom surface, a front surface, a proximal surface, and a distal surface. The preferred embodiment utilizes a wedge shape of approximately eight inches in width and height which is formed from a laminated rubber or rubber like material. The rubber or rubber like material maximizes the coefficient of static friction with the pavement upon which the chock rests. (i.e. an approximate value of 1.0 on concrete whereas the lightweight aluminum extrusion of Metz has an approximate value less than 0.6)
[0010] For the preferred embodiment, fasteners secure the laminations together and are in the form of one or more threaded rods or bolts which extend through the laminations. Also for the preferred embodiment, one or more plates, washers, or other surface force or load distributing members are placed under the heads or nuts of the fasteners.
[0011] For the preferred embodiment, a handle assembly is attached with and extends from the proximal surface of the chock. A roller assembly having one or more rollers or a dolly assembly is attached with the handle assembly aft of the proximal surface. The roller assembly is positioned with said handle assembly such that when the chock is placed under a wheel with the bottom surface touching the pavement, the rollers are slightly elevated above the pavement. This preferred positioning assures that the rollers do not have any of the chock load upon them when the chock is placed and utilized. For the preferred embodiment, said handle assembly is welded onto the proximal surface plate load distributing member via a handle assembly coupling extending from the proximal surface.
[0012] The roller assembly preferably comprises a carriage and one or more (preferably two) rollers or wheels rotatably attached with said carriage. The carriage is preferably attached via one or more welds with the handle assembly. The user is able to lift the chock by pressing the proximal grip portion towards the pavement and thereafter roll the apparatus to a desired position.
[0013] For the preferred embodiment, the distal surface of the chock has a chain or cable attachment assembly in the form of an eyelet or “U” shaped extension extending therefrom. This allows the apparatus to be secured to a building, structure, or post in order to prevent theft and unauthorized use.
[0014] Operation of the apparatus is simple and intuitive. The user first simply disconnects the apparatus from any building, structure, or post with which it is attached. The user then presses downward (towards the pavement) upon the proximal grip portion and rolls the apparatus to a desired location such as under or behind a vehicle wheel. After use, the user simply repeats the aforesaid procedure and rolls the apparatus to a desired location. The roller assembly allows for easy and convenient placement of the chock and construction of the chock from a heavy and durable material.
[0015] The art of the present invention may be manufactured from a plurality of materials including but not limited to rubber or rubber like materials, metals and alloys thereof, polymers, composites, woods, or ceramics without departing from the scope and spirit herein intended. The apparatus may further be manufactured via molding, machining, casting, forging, pressing, laminating, carving, or utilization of stereo-lithographic or electro-dynamic milling or other techniques which are appropriate for the material utilized.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Numerous other objects, features, and advantages of the invention should now become apparent upon a reading of the following detailed description taken in conjunction with the accompanying drawings, in which:
[0017] FIG. 1 is a right front perspective view of a wheel chock having a roller assist;
[0018] FIG. 2 is a front view thereof;
[0019] FIG. 3 is a rear view thereof;
[0020] FIG. 4 is a left side plan view thereof;
[0021] FIG. 5 is a right side plan view thereof;
[0022] FIG. 6 is a top plan view thereof;
[0023] FIG. 7 is a bottom plan view thereof.
DETAILED DESCRIPTION
[0024] Referring now to the drawings, there is shown in the Figures a preferred embodiment of a wheel chock having a roller assist 10 . In its preferred form, the present art apparatus 10 comprises a chock 12 , a handle assembly 42 , and a roller assembly 36 upon which the entire apparatus 10 may be rolled into position.
[0025] In its preferred form, the art of the present invention represents a chock 12 in the form of a generally wedge shaped structure with a wheel contacting surface 14 , a bottom surface 16 , a front surface 18 , a proximal surface 28 , and a distal surface 24 . Preferably said contacting surface 14 is contoured or shaped, i.e. a arcuate surface, to mate or touch with a vehicle wheel. For the preferred embodiment the chock 12 is formed from a laminated rubber or rubber like belting material 20 having a plurality of layers (laminations) with one or more fasteners 30 extending through the laminations 20 . The fasteners 30 are capable of compressing the laminations 20 together as a solid and strong chock 12 . The preferred embodiment utilizes a wedge shape of approximately eight inches in width and height with alternative embodiments utilizing a plurality of heights and widths based upon the application and user preference.
[0026] Alternative embodiments may utilize a plurality of chock 12 forms (i.e. wedge shaped, elliptical shaped, circular shaped, and rectangular shaped) and methods of manufacture, including but not limited to molding, casting, machining, and laminating. Alternative chock 12 embodiments may be manufactured from a plurality of materials, including but not limited to, polymers, composites, metals, and woods.
[0027] For the preferred embodiment, the fasteners 30 are in the form of one or more threaded rods or bolts 32 which extend through the laminations 20 and are secured via a head or a nut 33 on the proximal 28 or distal 24 surfaces. Also for the preferred embodiment, one or more plates, washers, or other surface force or load distributing members 34 are placed under said heads or nuts 33 . The preferred embodiment utilizes a somewhat triangular shaped plate 34 through which said threaded rods or bolts 32 are placed and which function to fully sandwich the laminations 20 there between. Alternative embodiments may utilize a plurality of fastener 30 forms including but not limited to rivets, pins, screws, and adhesives. Alternative embodiments may also utilize a plurality of load distributing member 34 shapes or none at all based upon user desires, durability requirements, and cost constraints.
[0028] For the preferred embodiment, a handle assembly 42 is attached with or near and extends from the proximal surface 28 of the chock 12 . A roller assembly 36 having one or more rollers or a dolly assembly 40 is attached with the handle assembly 42 aft (i.e. between the proximal grip portion 46 and the proximal surface 28 ) of the proximal surface 28 of the chock 12 . Alternative embodiments may attached said roller assembly 36 with said chock 12 provided the rollers 40 are positioned aft (i.e. between the proximal grip portion 46 and the proximal surface 28 ) of said proximal surface 28 . The roller assembly is positioned with said handle assembly 42 such that when the chock 12 is placed under a wheel with the bottom surface 16 touching the pavement 50 , the rollers 40 are slightly elevated above the pavement 50 . This preferred positioning assures that the rollers 40 do not have any of the chock 12 load upon them when the chock 12 is placed and utilized. For the preferred embodiment, said handle assembly 42 is attached onto the proximal surface 28 plate load distributing member 34 via a handle assembly coupling 29 extending from the proximal surface 28 . In a preferred form, said coupling 29 comprises a tube of substantially equivalent inside diameter as the outside diameter of the handle assembly 42 tubular member 44 . Alternative embodiments may attach said handle assembly 42 with said chock 12 in a plurality of ways including but not limited to pins, friction or press fits within said chock, screws, welds, or adhesives.
[0029] For the preferred embodiment, the handle assembly 42 is a partially “S” shaped tubular member 44 which extends from at or near the proximal surface 28 of the chock 12 to a proximal grip portion 46 of the handle assembly 42 . The proximal grip portion 46 preferably has a grip 48 (i.e. similar to that found upon a bicycle handlebar) which allows the user to easily hold the handle assembly 42 and move the chock 12 on the roller assembly 36 . For the preferred embodiment, the proximal grip portion 46 , when the handle assembly 42 is attached with the chock 12 , is approximately three feet in height and two and one half feet proximal or rearward from the proximal surface 28 of the chock 12 . Alternative embodiments may utilize a handle assembly 42 of any user desirable shape or size and place the height and rearward position at any user desired position.
[0030] The roller assembly 36 preferably comprises a carriage 38 and one or more (preferably two) rollers 40 (i.e. small wheels) rotatably attached with said carriage 38 . For the preferred embodiment the carriage 38 is a substantially flat plate which is attached with said handle assembly 42 on a first leg of said “S” shaped tubular member 44 near said proximal surface 28 of the chock 12 . The carriage 38 is preferably attached via one or more welds but may utilize alternative techniques including but not limited to screws, pins, clamps, bands, or adhesives and may be removable. For the preferred embodiment, the rollers 40 are approximately two and three quarters inch in diameter and positioned so that the circumference is slightly above the pavement 50 when the chock 12 is placed under a wheel. That is, the circumference is positioned slightly above a plane of said bottom surface 16 whereby a weight or a force placed upon said chock 12 does not place said weight or said force upon said rollers 40 . This positioning assures the user that no vehicle weight is placed upon the rollers 40 when the chock 12 is placed under the vehicle wheel. Alternative embodiments may attach the rollers 40 directly to the handle assembly 42 via a plurality of methods (i.e. holes within the handle, welds, retainers, or others methods recognized within the mechanical arts) or utilize a plurality of roller 40 diameters. The roller(s) 40 may be positioned at a plurality of positions aft of the proximal surface 28 of the chock 12 provided that the roller(s) 40 serve as a pivot axis or loci of rotation between the proximal grip portion 46 and the chock 12 . That is, the user should be able to lift the chock 12 by pressing the proximal grip portion 46 towards the pavement 50 and thereafter roll the apparatus 10 to a desired position.
[0031] For the preferred embodiment, the distal surface 24 of the chock 12 has a chain or cable attachment assembly 26 in the form of an eyelet or “U” shaped extension extending therefrom. This allows the apparatus 10 to be secured to a building, structure, or post in order to prevent theft and unauthorized use. Also for the preferred embodiment, the attachment assembly 26 is formed from approximately ½ inch steel rod, bent into a “U” shaped form, and threaded with two of the fasteners 30 extending through the chock 12 . Alternative embodiments may utilize attachment assemblies 26 having a plurality of forms which are integral with or external to the chock 12 provided the attachment assembly 26 is capable of securing the chock 12 .
[0032] Operation of the apparatus 10 is simple and intuitive. The user first simply disconnects the apparatus 10 from any building, structure, or post with which it is attached. The user then presses downward (towards the pavement 50 ) upon the proximal grip portion 46 and rolls the apparatus 10 to a desired location such as under or behind a vehicle wheel. After use, the user simply repeats the aforesaid procedure and rolls the apparatus 10 to a desired location. The roller assembly 36 allows for easy and convenient placement of the chock 12 and construction of the chock 12 from a heavy and durable material.
[0033] Although described for enablement purposes, the lengths, widths, and other dimensional attributes may depart significantly from those specified. The shape, size, location, component numbers and mounting methods utilized for each of the components or constituent elements may take a plurality of forms as recognized within the pertinent arts without departing from the scope and spirit of the present invention.
[0034] Having described the invention in detail, those skilled in the art will appreciate that modifications may be made to the invention and its method of use without departing from the spirit herein identified. Therefore, it is not intended that the scope of the invention be limited to the specific embodiments illustrated and described. Rather, it is intended that the scope of this invention be determined by the appended claims and their equivalents. | A wheel chock having a roller assist comprised of a chock, a handle assembly, and a roller assembly. The wheel chock is controlled and lifted by the handle assembly pivoting on the roller assembly. The roller assembly allows rolling of the chock by a user without the necessity of actually lifting the chock. The preferred embodiment utilizes a chock of a heavy and structurally strong rubber or rubber like laminated belting material. The belting material provides an assured grip with the underlying pavement and also forms a structure which is substantially indestructible by a vehicle or a truck. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a division of my copending U.S. patent application Ser. No. 665,805, filed on Mar. 11, 1976, which is a continuation of application Ser. No. 412,581, filed Nov. 5, 1973 Application Ser. No. 665,805 is now U.S. Pat. No. 4,128,951 and application Ser. No. 412,581 is now abandoned. The disclosure of each of these is incorporated by reference.
BACKGROUND OF THE INVENTION
There are many applications for articles which, in a first form, are easily shaped or molded to a second form in which the article is form stable. This application relates generally to such articles.
The use of casts, fabricated from plaster of paris and like substances, and contoured to the portion of a body for which they are designed to lend support is well-known. Such casts are typically fabricated by methods involving the use of a mixture of plaster of paris and water or other suitable material.
The use of molds and casts for taking impressions of a variety of tangible objects or forms, such as, for example, models, tooth cavities, machine parts and decorative plaques are well-known.
Such molds and casts are ordinarily fabricated by simply pouring the plaster of paris and water mixture or other material into an impression or around the article to be molded and thereafter allowing said mixture to cure. Alternatively, a room temperature vulcanized (RTV) silicon rubber liquid can be mixed with a suitable catalyst and poured over the article for which a mold is desired. When the rubber is cured, it can be separated from the object and used as a mold of the object.
More recently, curable polymeric materials have been used to prepare, in situ, the padding for ski-boots, in effect making each pair a custom made item since the curable material conforms to the leg of the owner.
The use of removable arch supports in shoes is also well-known. Such arch supports are manufactured in standard sizes and shapes, typically by using several layers of leather and selecting each piece of leather as to size and configuration so that the composite structure assumes the desired shape.
Custom-made arch supports that are removable from the shoe are likewise well-known. A measurement technique is employed, such as by making an impression of the bottom of the foot and then fabricating the arch support accordingly.
The procedures for fabricating molds, splints, braces and casts for tangible forms such as, for example, chess pieces, decorative plaques, portions of the human body or any of other myriad purposes, heretofore available however, have left much to be desired. Likewise, the procedures for fabricating arch supports, heretofore available have left much to be desired.
The methods for fabricating such molds, splints, braces and casts for the purposes hereinbefore described involve an untidy procedure and a great deal of difficulty and time in completing the same.
With respect to the arch supports, ready-made products generally do not fit very well, while the custom-made products involve a great deal of difficulty, time, and expense in completing their fabrication.
An object of the present invention is to provide a readily moldable article which, after molding, is form stable.
Another object of the present invention is to provide a means for making articles of unusual shape or configuration.
Another object and purpose of the present invention, therefore, is to provide a method for preparing molds, casts, splints, prosthetic devices or braces for the purposes as hereinbefore explained, and custom made machine castings, decorative plaques, ski boot padding, arch supports or shoe inserts, and the like which will be a tidier and more simple procedure. Insofar as devices to be worn by humans are concerned, the method provides devices with a high degree of comfort for the wearer. The method can also be carried out with a minimum of time or expense.
SUMMARY OF THE INVENTION
The invention, though being of general application to a variety of uses and having numerous tangible forms, as will be described herein, will, however, for the purpose of illustrating the invention, be initially explained with specific reference to a custom-formed shoe insert.
In accordance with the present invention a container having flexible upper and lower walls is filled with a formable material that is capable of curing at about room temperature to form a form-stable material, and the container is inserted in the shoe beneath the bottom of the foot. Preferably, the formable material is a polymeric or prepolymeric material that yields an elastomer or other polymeric material when cured and an appropriate curing agent. Appropriate pressure is applied downwards on the foot while the formable material is curing. The end result is a shoe insert whose upper surface precisely fits the bottom of the foot of the wearer, while its lower surface precisely fits the inner shoe surface.
Generally, the invention comprises the provision of a preformed prosthetic blank which is at least substantially closed and the walls of which are composed generally of flexible barriers. The prosthetic blank is configured in the form of a blank unformed arch support and is adapted to be inserted in a shoe and subjected to an in situ molding process for the purpose of producing a prosthetic foot device in situ. The structural shape of the prosthetic foot device is determined by providing within the interior of the prosthetic blank a curable but initially moldable material.
In one form the material which is to be cured to provide the necessary resilient structural rigidity for the prosthetic device is incorporated within the prosthetic blank at the time of manufacture. In the configuration where the prosthetic blank, as supplied to the customer, contains moldable material within it, there is generally included within the closed walls of the prosthetic blank a curable pre-elastomeric material and a catalyst or cross-linking agent suited for curing the pre-elastomeric material as well as other conventional materials such as, for example, fillers, sponge rubber or cork granules, foaming agents, and the like. The catalyst or cross-linking agent is separated from the polymeric material by a barrier of a material which is, or readily rendered, frangible and thus is easily broken through suitable manipulation of the prosthetic blank to initiate a polymerization reaction.
In the configuration where the prosthetic blank contains no polymeric or prepolymeric material, as supplied to the customer, provisions are made for injecting this material into the prosthetic blank at the time of use. The prosthetic blank must first be squeezed flat or otherwise evacuated so as to remove air bubbles from within the interior of the closed prosthetic blank. Evacuation is followed by the introduction of a suitable premixed polymeric admixture which then polymerizes in situ. In situ molding is accomplished by inserting the prosthetic blank into a preselected shoe or, in another form of the invention, into a ski boot. In the case of a prosthetic device, the intended wearer of the shoe then inserts his foot into the shoe on top of the prosthetic blank. The polymerizable reaction admixture which is provided in the prosthetic blank is allowed to polymerize while the wearer of the shoe applies appropriate pressure on the prosthetic device by standing or by pressing his foot against an appropriate surface. Preferably, pressure is applied by seating the customer and placing weights on his knees, for example, by using sandbags of appropriate weight. By applying less than the customer's full weight on the blank, the foot is incompletely flattened. As a result, the device in its cured state conforms to the incompletely flattened foot. Therefore, support is provided the arch when the customer's full weight is brought to bear on the foot.
The cured final shape of the prosthetic device is determined in some substantial part by the amount of pressure applied during the in situ molding, with the arch being depressed to a flatter profile by increasing the pressure on the prosthetic device during the molding operation. The molding is continued for a period of time sufficient to permit the polymerizable reaction admixture to set to a resiliently rigid condition such that changes or alteration in pressure will not substantially alter its shape.
Curing should be accomplished at approximately room temperature or, in any event, at a temperature such that the wearer of the shoe will not experience any discomfort during the molding process. Also the nature of the curable admixture should be such that it does not generate a great deal of exothermic heat during the polymerization reaction. Suitable polymerizable reaction admixtures are well-known and include for example, room temperature vulcanizing (RTV) silicone rubber forming admixtures, and the like. Such materials are available from, among others, the Dow Corning Company.
When the procedure is followed where the prosthetic blank is first evaluated and then the curable admixture is injected into the void defined by the walls of the prosthetic blank, suitable equipment is provided which preferably accomplishes both the evacuation and the injection without subjecting the wearer of the shoe to long delays. A product resulting from this in situ molding process is a custom made prosthetic foot device which is precisely contoured to the upper surface of the individual shoe's sole and the bottom of the individual wearer's foot.
According to one mode of practicing the invention, the flexible container is evacuated and filled with formable material and is sealed before being inserted into the shoe. A downward pressure on the foot, preferably of a constant value, is maintained as previously described while the formable material is curing. The shoe insert is then complete and ready for use. Accordingly to this first mode of practicing the invention, the amount of formable material that is contained inside the flexible container has to be determined or selected before actually fitting the shoe insert to the foot and shoe of the wearer. The selection process may be accomplished in two different ways.
One way is to choose an empty container having an opening, make a measurement from the foot and the shoe of the customer to determine the amount of filler material that is needed, and then after evacuating air to insert this amount of material into the container and close and seal the container.
Another way of achieving the desired result is to prepare ready-made containers of various shoe sizes and arch void sizes each of which has a predetermined amount of filler material inside. A particular container to be used for a particular customer may then be selected on the basis of the size and shape of the container and the quantity of filler material which it contains. Where ready-made containers are being used, it is necessary to control the initiation of the curing of the filler material. A filler material may be used which is normally in a liquid state but when exposed to a curing agent will cure to a resilient permanent state. The quantity of curing agent that is needed may be quite small. In one embodiment the catalyst is placed inside a bulb, or inner container, that is of frangible construction. Prior to placing a shoe insert inside the shoe it is then necessary to exert pressure on the flexible container at the spot where the bulb or inner container is located, in order to fracture the bulb and thereby release the curing agent, and then the container is kneaded to intimately mix the curing agent and filler materials.
To better distribute the curing agent throughout the formable material, and reduce or eliminate the need for kneading the article to achieve distribution of the curing agent, the agent may be contained in plural small frangible containers positioned throughout the flexible outer container rather than in a single container. The plural containers are preferably uniformly distributed throughout the curable material. The plural containers may take the form of small spheres or be elongate tubular structures. In yet another form of the invention, the curable material and curing agent may be arrayed in alternating layers separated by frangible barriers.
When preformed, it is expected that the moldable article will be shipped to the user. This prevents the opportunity during handling for premature rupture of the frangible containers that separate the curing agent from the curable material. In a particularly preferred embodiment of the present invention, the frangible container is initially formed of a pliant material capable of being rendered frangible by the user. Materials suited to this end are partially cross-linked materials that can be further embrittled by additional cross-linking when exposed to heat, ionizing radiation, microwave radiation, ultrasonic aging, pressure or other suitable initiators.
When the article is formed using a relatively flexible prefrangible material to encase the curing agent, the article can be handled without fear of rupturing the container holding the curing agent until the operation which renders the material frangible is performed.
According to a second mode of practicing the invention the evacuated empty container is filled at the same time it is being fitted to the foot. The empty container is placed within the shoe beneath the foot of the wearer or customer. Then an appropriate amount of formable material is inserted through the opening into the interior of the container. Sufficient pressure is placed on the formable material to fill the container. As before, appropriate weight is then maintained on the foot until the formable material has cured.
DRAWING SUMMARY
FIG. 1 illustrates one embodiment of the present invention and specifically, a top plan view of a ready-made shoe insert;
FIG. 2 is a longitudinal cross-sectional view of the shoe insert of FIG. 1;
FIG. 3 is a fragmentary cross-sectional view of the shoe insert of FIG. 1;
FIG. 4 is an elevational view, partially in cross-section, showing the insert in its operative position between the foot and the shoe of the wearer;
FIG. 5 is a transverse cross-sectional view taken on the line 5--5 of FIG. 4;
FIG. 6 is a perspective view of a measuring apparatus provided in accordance with the present invention;
FIG. 7 is a cross-sectional elevational view taken on the line 7--7 of FIG. 6;
FIG. 8 is a fragmentary cross-sectional view taken on the line 8--8 of FIG. 7;
FIG. 9 is an elevation view, partially in cross-section, of the foot and shoe of the wearer when the measuring apparatus of FIG. 6 is being used;
FIG. 10 is a transverse cross-sectional view taken on the line 10--10 of FIG. 9;
FIG. 11 is a perspective view of a custom-filled shoe insert together with the apparatus for filling it;
FIG. 12 is a cross-sectional elevation view taken on the line 12--12 of FIG. 11;
FIG. 13 is a fragmentary cross-sectional view taken on the line 13--13 of FIG. 12;
FIG. 14 is an elevation view, partially in cross-section, of the insert of FIG. 11 when inserted in the shoe of the wearer;
FIG. 15 is a transverse cross-sectional view taken on the line 15--15 of FIG. 14;
FIG. 16 is a fragmentary cross-sectional view taken on the line 16--16 of FIG. 14;
FIG. 17 is a top view of a custom-filled shoe insert having a cutaway portion.
FIG. 18 is a fragmentary cross-sectional view taken on the line 18--18 of FIG. 17;
FIG. 19 is a top view of a custom filled shoe insert having a cutaway portion.
FIG. 20 is a fragmentary transverse cross-section of the insert of FIG. 19; and
FIG. 21 is a cross-section of a woven material according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference is now made to FIGS. 1 through 5, inclusive, illustrating a ready-made shoe insert in accordance with the invention, and the manner in which it is used.
A flexible container 10 has an upper wall 11 and a lower wall 12. The walls 11 and 12 are generally parallel to each other; more specifically, however, the upper wall is adapted to approximately conform to the bottom of the foot of the wearer or customer, while the lower wall 12 is adapted to approximately conform to the inner surface of the shoe. Continer 10 is filled with a liquid material 13 which comprises a curable material. Such materials are well-known and include, for example, polyesters and polyurethanes. Such materials are disclosed in U.S. Pat. No. 3,782,390 and U.S. Pat. No. 3,786,580. Curable epoxy resins and silicone rubbers such as Dow Corning RTV (Room Temperature Vulcanizing) silicone rubbers which cure at room temperature may also be used. The curing agents for these are selected catalysts for crosslinking. Also suited for certain uses are the latexes of natural or synthetic rubber. In such cases, the curing agent is a dryer for the latex. Inside the container 10 there is a bulb or inner container 15, which is of relatively small size compared to the container 10. The bulb or inner container 15 is frangible, that is, it is easily fractured or ruptured in response to the application of pressure. Contained within the bulb 15 is a liquid or, perhaps, a powdered material 16 which is a curing or drying agent for the curable material. In chemical terms the material 16 might, therefore, be identified as a catalyst.
Prior to placing container 10 inside the shoe of the wearer it is necessary to rupture the bulb or inner container 15. This is accomplished by applying pressure to both the upper wall 11 and the lower wall 12 of the container 10, as indicated in FIG. 3 by the arrows 18. The result is that bulb or inner container 15 is ruptured and the catalytic material 16 is dispersed into the liquid material 13.
The next step is to perform a mixing or kneading operation which may be accomplished by shaking, twisting, and otherwise manipulating the container 10.
Container 10 is then placed inside the customer's shoe and the customer puts his foot in the shoe as shown in FIG. 4. A downward weight is applied to the customer's foot as previously described while the formable material, now identified by numerals 13-16 to indicate both of its components, completes its setting and curing. The amount of weight applied to the foot is preferably maintained at about a constant level. It is preferred to utilize a selected and properly weighted sandbag, or some other convenient type of auxiliary apparatus, in order to insure that the correct amount of downward force is exerted on each foot and also in order to insure that the amount of downward force is relatively constant while the formable material is setting. Then the device is ready for use by the customer.
The shoe insert as illustrated in FIGS. 1 to 5, inclusive, is of such size as to fit beneath part of or the entire length of the customer's foot and fill part of or the entire length of the shoe. However, essentially the same device may be made in a much smaller configuration so that it fits only into the arch beneath the arch of the foot. The method of constructing the device, and the method of using it, are essentially the same in either application.
Container 10 may be integrally formed from a single material, or the upper and lower walls may be formed of different materials and adhesively secured around their peripheral edge. A flexible leather insole may be affixed to the outside top of the flexible container (in contact with the bottom of the wearer's foot) to absorb perspiration to add comfort in wearing and to ease insertion of the foot into the shoe.
MEASURING APPARATUS
Reference is now made to the drawings, FIGS. 6 through 10, inclusive, which illustrates a measuring apparatus provided in accordance with the present invention.
A flexible container 20, best shown in FIG. 6, is used for measuring the volume or quantity of the filler material that should be used in order to fit the foot of a particular customer with the greatest degree of comfort. Container 20 may, for example, be of the same size and configuration as container 10, so that the volume measurement made by utilizing container 20 and its associated apparatus will directly and precisely indicate the volume or quantity of filler material that should be utilized in the container 10 to provide a cured article that conforms to the arch cavity of the customer. Alternatively, a single container may first be used for measuring, then evacuated and filled with formable material to provide the shoe insert.
Container 20 also has a laterally projecting portion 21 which protrudes laterally outward from the instep portion of the container. A flexible tube 22 is attached to the container extension portion 21.
A pump P controlled by a valve V is utilized for supplying an incompressible liquid through the tube 22 in order to fill the container 20 to the desired level. The pump chamber 32 is filled with the incompressible fluid and the measurement of the volume of fluid used to fill container 20 is made by utilizing a scale 33 provided on the pump marked in arbitrary or standard units (milliliters, ounces, etc.). After this measurement has been made, the flexible container 20 is emptied of the incompressible fluid, e.g., it is evacuated through line 22 by suction applied to line 27 from a vacuum line as explained more fully below. A supply line 25 is utilized for refilling the chamber 32 of pump P to its normal level, i.e., to the zero point.
In actual use, a flexible container 20 is placed in each of the shoes of the customer, and the customer is seated and instructed to place the bottom of his foot on top of the containers 20. Sandbags of a prescribed weight are placed on each knee to maintain a constant weight on the feet. Pump P is then employed to fill the container 20 with the incompressible fluid so that the upper surface of the container is in intimate contact with the bottom of the foot while its lower surface is in intimate contact with the inner bottom surface of the shoe. A reading on the scale 33 is then taken to indicate the volume of fluid injected into container 20. The reading will be that at the maximum advance of plunger 34. The volume determined in this way is then used as a measure of the amount of moldable polymeric material which is used to make the arch support as described herein.
The selection of weight value applied on the customer's foot during the fitting process is most important. If a heavy weight is applied, such as the total weight of the person, the arch of the foot is greatly deflected downward. As a result the volume of filler material required in the insert will be at a minimum, and the supporting action which the shoe insert provides to the arch during normal walking and standing will be at a corresponding minimum. On the other hand, if minimum weight is applied to the foot during fitting, such as one-fourth of the weight of the person, then the amount of filler material required in the shoe insert will be at a maximum. The reason is that the space between shoe and foot is greater. The shoe insert when completed will then provide a corresponding maximum amount of support to the arch of the foot. The selected weight value should be held constant when measuring the required volume of the filler material, and again held constant at the same value when the ready-made shoe insert is being completed by curing the filler material.
The base 41 of the pump has a cylindrical chamber which receives the rotary valve V. The external surface of valve V has an annular groove 45 extending somewhat more than 90 degrees, which receives a screw 42 in order to limit the rotary movement of valve V to a quarter circle. Valve V has a longitudinal central opening 48 which always communicates through a passageway 47 (FIG. 8) with the tube 22. It also has a lateral or vertical opening 49 which has two alternate positions corresponding to the extreme rotary positions of the valve. In the position of valve V as shown in FIGS. 7 and 8 the valve passageway 49 communicates with a vertical passageway 44 in the housing 41. Passageway 44 communicates with a chamber 52 in the lower end of tubular member 51, and a ball type check valve 52 is urged by a spring toward the upper end of chamber 52. Chamber 52, except when closed by valve 53, communicates through a vertical passageway 54 with the pump chamber 32. Pump P has a plunger 34 which is movable vertically relative to the pump housing 31.
It is assumed that initially the chamber 32 of the pump P is filled with liquid to the zero point of the scale 33. The operation of filling the container 20 to the desired volume takes place as follows:
Plunger 34 is moved downward which causes valve 53 to open. Liquid flows from chamber 32 through passageway 54 and chamber 52 into the passageway 44. From there it flows into the valve passage 49 and out the valve passage 48 through passage 47 into tube 22. When the flexible container walls are in intimate contact with both foot and shoe, a reading is taken on the scale 33 of pump P. This intimate contact generally occurs within a pressure range of about one to ten inches of water, and it is preferred to establish this pressure level by means of an automatic pressure regulator, not specifically shown. In any event, the amount of fluid injected is sufficient to fill the arch cavity and, if desired, to inject a small amount under the ball and heel of the foot to provide a cushion.
In order to evacuate the container 20, the valve V is rotated to its alternate position. Valve passage 49 then communicates through passage 43 (FIG. 7) with the vacuum line 27. The contents of container 20 are then withdrawn through the vacuum line 27.
While keeping valve V in its rotated or alternate position as just described, the pump may be refilled. Tubular member 51 has a horizontal passageway 55 which communicates with vertical passageway 54. A chamber 56 is formed at the outer end of passageway 55. A passageway 58 communicates between chamber 56 and the refill tube 25. A ball-shaped valve 57 is supported in chamber 56 and normally closes the passageway 58. As the plunger 34 of pump P is raised, however, check valve 57 opens and liquid is drawn from the tube 25 through passageways 58, 56, 55 and 54 into the pump chamber 32.
When the volume of liquid has been measured as described above, a preformed insert as previously described having that volume of curable material can be selected for use. Alternatively, a custom filled insert can be made by injecting the measured volume into a flexible container as discussed below.
CUSTOM-FILLED INSERT
Reference is now made to the drawings, FIGS. 11 through 16, inclusive, illustrating a custom-filled insert provided in accordance with the present invention.
A flexible container 60 has generally the same configuration as has been shown by the containers 10 and 20. Container 60 is to be filled with a formable material capable of curing to a resilient state. Pump P' contains a quantity of the pre-catalyzed material in liquid form. A tube 62 couples pump P' to the resilient container 60, and the operation of the pump is controlled by a valve V'.
Container 60 is placed inside the shoe of the customer. The downward pressure of the customer's foot is then maintained at a constant level in the manner already described. Container 60 and tube 62 are evacuated through line 67 by turning valve V' to its alternate position.
The valve is then returned to the position shown in FIGS. 12 and 13. The plunger of pump P' is pushed downward in order to fill container 60 with the pre-catalyzed formable material. Preferably pump P' is calibrated so that the volume of material delivered to container 60 can be measured. The amount delivered may, for example, that determined using the measuring apparatus described above. A gage G coupled in communication with the supply line 62 may advantageously be used to control the level of pressure that is applied to the formable material. Initially the material is quite liquid with a rather low viscosity, and may be injected into the container under a rather low pressure. The material then cures and hardens in about ten minutes, in a configuration that is determined by the shapes of both the foot and the shoe.
The pressure level as indicated on gage G is significant when container 60 is first being filled, because at this point of time the filler material has a low viscosity and the pressure measurement is quite meaningful. The optimum level of pressure is of the order of one inch of water where both of the container walls are made of highly flexible material. This amount of pressure is then adequate to provide an intimate contact of the upper wall of container 60 with the bottom surface of the foot, and an intimate contact of the lower wall of the container 60 with the inner surface of the shoe. If the container 60 is made of material having any degree of stiffness, however, a significantly higher level of pressure may be required.
When the formable material has cured, the insert is removed from the customer's shoe and the lateral protrusion 61 is cut off along the dotted line 69, as shown in FIG. 11. The customer now has a completed shoe insert that is ready for his permanent usage.
The cleaning of pump P' may present a problem because of the curing and consequent hardening of the filler material. However, it is possible to construct the pump from plastic materials which are inexpensive and can be thrown away after a single usage.
Still another variation of the invention provides a custom-filled shoe insert without the necessity of evacuating the flexible container. The bottom wall of the container is made of non-porous material whereas the upper wall is made of a material which has a certain degree of porosity, such as leather or synthetic leather or the like. The degree of porosity of the latter material is selected so as to permit entrapped air to escape through it, but not the formable material. Therefore, when the formable material is injected into the container the entrapped air is driven out through the pores of the upper wall.
FIG. 17 illustrates yet another ready-made shoe insert employing a preferred feature of the present invention. Shown in FIG. 17 is a flexible container 70 of generally the same construction as containers 10 and 60. Container 70 is similarly filled with a curable material. Plural hollow tubes 72 which contain the curing agent are distributed throughout the container as better seen in FIG. 18.
Preferably, the tubular elements are made of a pliant material that does not break or rupture even with severe handling but which is capable of being converted to frangible material by an embrittling operation. For example, the tubes may be extruded from an uncrosslinked or partially crosslinked polymeric material susceptible of being cured to a frangible state by the action of microwave radiation, ionizing radiation such as gamma radiation, neutrons or high energy electrons, or by the application of heat or other suitable means.
As fabricated, the article can be handled routinely in packaging and shipment. However, just prior to use, the article is exposed to the condition which embrittles the tubular elements. When this operation is complete, the article is manipulated to rupture the tubes and fitting of the insert is accomplished as described in connection with FIG. 1.
Yet another refinement of the present invention is shown in FIG. 19 which illustrates a shoe insert of generally the same configuration as that illustrated, for example, in FIG. 1. In FIG. 19 is illustrated a container 80 which is filled with a curable material. The curing agent is carried in frangible nodules or bubbles on a sheet 81. The construction of sheet 81 is better seen in FIG. 20 which illustrates, in partial transverse cross-section, the inserts of FIG. 18. The walls of container 80 is formed by walls 82 and 83. Disposed within the curable material are sheets 81 defined by a layer 84 having plural bubbles 85 disposed thereon. The curing agent is located in the space defined by the bubbles 85 and layer 84. The sheet is frangible and the bubbles can be caused to rupture to release the curing agent by manipulating the sheets.
Preferably the sheet 81 is fabricated initially from a prefrangible material as described in connection with the discussion of FIGS. 17 and 18 to prevent premature rupture of the bubbles during handling. Prior to use, the article is exposed to the operation which embrittles the sheet 81.
The foregoing description has focused on articles in which the curable material and curing agent are contained within a flexible container. However, this expedient may be unnecessary and even undesirable for certain applications. Thus, in another embodiment of the invention, the curable material can be contained within the pores of a foamed polymeric material, for example a foamed elastomer such as a polyurethane. Impregnation of the foam may be accomplished by dipping it in the liquid curable material. Excess liquid is pressed out of the foam which is then sandwiched between two sheets like sheet 81 in FIG. 19 which contain the curing agent. The article may be made from components cut to size or the article can be trimmed to a desired shape after assembly.
In a further embodiment, the article may comprise a coherent mass of flexible fibers. The coherent mass may be formed by weaving a cloth or by twisting or braiding a length to form a cord or rope. Alternatively, the mass may be a simple batting of entangled fibers.
As fabricated, the largest portion of the fibers will be coated with a viscous curable material. This may be accomplished by dipping the mass in liquid curable material. However, at least a portion of the fibers are hollow tubes of a frangible material containing the curing agent. One such arrangement is shown in FIG. 21, a sectional view of a woven material in which 91 represents a fiber, for example, a natural fiber like cotton or a synthetic fiber such as nylon, coated with a curable material 92. Also woven in the material are hollow tubes 93 of frangible material which contain the curing agent.
The tubes are formed initially of prefrangible material so that the article can be wound or folded for compact storage. Then the article is treated, perhaps by passage through an oven, exposure to microwave radiation or other means to induce further crosslinking to embrittle the tubes containing the curing agent.
When it is desired to use the article, the frangible tubes are ruptured. This can occur during handling by the unwinding or unfolding of the mass or by other suitable manipulation. After the tubes are ruptured, the mass is given a configuration it is desired it retain.
A gauze structure formed in this way could be used to make an orthopedic device which would function like a plaster cast. For example, after setting of a broken bone, an injured limb could be wrapped with the gauze, usually over a protective covering for the limb. When the curable material sets up, the gauze rigidifies and will support the limb as does a conventional cast. Then, if desired, a protection layer may be applied over the gauze. Such a gauze would be porous and, therefore, more comfortable to wear than a plaster cast.
ALTERNATE FORMS
According to the present invention the flexible container 10, 60, 70 or 80 may, if desired, be dismembered and removed so that the cured filler alone may be used as the shoe insert.
According to another variation of the invention a cover member is attached to one surface of the flexible container and becomes a part of the complete shoe insert.
ALTERNATE APPLICATIONS
It should be noted that the technique disclosed herein is not limited to shoe inserts but may also be applied to another body member or to other tangible objects.
SPLINTS, BRACES AND CASTS
The present invention can be utilized for the immobilization of a broken arm or other limb by applying the formable material filled outer container against or around the same until the material cures, whereafter said container can be secured by usual means such as by the use of adhesive or cloth bandages.
MOLDS AND CASTS
Impressions in the form of footprints, human faces, fossils, decorative plaques or other tangible objects can be fabricated for the purpose of making a mold or cast or for maintaining the likeness of the original in a substantially permanent state by the method of the present invention.
The importance of this invention is even more apparent in the area of custom made furniture and prosthetic devices.
Once the catalyst and the formable elastomeric material are united in the outer container in accordance with the procedure as hereinbefore explained, the outer container is comfortably applied to the desired object or portion of the anatomy.
After the curing process is complete, the container is removed from the object, whereupon it is evident that substantially every curve, depression and form of that object has been duplicated onto the container.
From this duplication, the designer is able to custom contour the item of furniture or prosthetic device or other tangible form to the individual specifications of that object, or person, as the case may be. For example, seats for custom made automobiles, space craft or the like could be made by application of the present invention.
The invention has been described in considerable detail in order to comply with the patent laws by providing a full public disclosure of at least one of its forms. However, such detailed description is not intended in any way to limit the broad features or principles of the invention, or the scope of patent monopoly to be granted. | A moldable article useful for making a form-stable article is described. The moldable article comprises a formable material that is a moldable polymeric or prepolymeric substance that can be cured to a form stable state and a curing agent, in close proximity to the curable substance but isolated therefrom, in frangible hollow fibers. In use, the frangible hollow fibers are ruptured to release the curing agent and the moldable article, in a first configuration, can be shaped to a second configuration in which it is maintained until the formable material is cured sufficiently for it to be form-stable in the second configuration. The moldable article can be used to make molds, casts, support for a portion of the human or animal anatomy, or other articles with diverse utilities. | 8 |
This application claims the benefit of Ser. No. 60/039,614, filed on Mar. 18, 1997.
FIELD OF THE INVENTION
The present invention relates to brines used during drilling and completion operations. More particularly, the invention relates to preparation of water soluble polymers to be used in high density drilling, drill-in, and completion brines.
BACKGROUND OF THE INVENTION
Drilling operations typically involve mounting a drill bit on the lower end of a drill pipe or “drill stem” and rotating the drill bit against the bottom of a hole to penetrate a formation, creating a borehole. A drilling fluid—typically a drilling mud—may be circulated down through the drill pipe, out the drill bit, and back up to the surface through the annulus between the drill pipe and the borehole wall. The drilling fluid has a number of purposes, including cooling and lubricating the bit, carrying the cuttings from the hole to the surface, and exerting a hydrostatic pressure against the borehole wall to prevent the flow of fluids from the surrounding formation into the borehole.
A drilling fluid with a relatively high viscosity at high shear rates can place undesirable mechanical constraints on the drilling equipment and may even damage the reservoir. Higher viscosity fluids also exert higher pressures outward on the borehole, which may cause mechanical damage to the formation and reduce the ability of the well to produce oil or gas. Higher viscosity fluids also may fracture the formation, requiring a drilling shut down in order to seal the fracture.
Damage to a reservoir is particularly harmful if it occurs while drilling through the “payzone,” or the zone believed to hold recoverable oil or gas. In order to avoid such damage, a different fluid—known as a “drill-in” fluid—is pumped through the drill pipe while drilling through the payzone.
Another type of fluid used in oil and gas wells is a “completion fluid.” A completion fluid is pumped down a well after drilling operations are completed and during the “completion phase.” Drilling mud typically is removed from the well using “completion fluid,” which typically is a clear brine. Then, the equipment required to produce fluids to the surface is installed in the well.
The viscosity of a drilling or completion brine typically is maintained using polymers, such as starches, derivatized starches, gums, derivatized gums, and cellulosics. Although these polymers are water-soluble, they have a relatively low hydration rate in brines because very little water actually is available to hydrate the polymers, particularly in high density brines.
Heating a brine to at least about 140° F. will increase the hydration rate of starches and/or other water-soluble polymers in the brine. However, heating of brine is time consuming, expensive, and difficult to achieve in the field. Plus, heating of a brine will cause starch dispersed in the brine to build excessive viscosity when subjected to high wellbore temperatures.
Less time consuming and expensive methods that will effectively hydrate water-soluble polymers in high density brines without adversely affecting downhole viscosity are sorely needed.
SUMMARY OF THE INVENTION
The present invention provides a method for producing a precursor polymer dispersion for addition to a brine for use in drilling and completion operations comprising providing a precursor brine having a first salt content, and mixing a water-soluble polymer with the precursor brine at a sufficient concentration and under conditions sufficient to produce a precursor polymer dispersion effective at a sufficient concentration in a final brine having a second salt content to improve the rheology and/or fluid loss control properties of the final brine.
DETAILED DESCRIPTION OF THE INVENTION
A desirable characteristic of any drilling fluid, including a brine, is the ability to flow easily at high velocities even at fluid densities in excess of 17 lb/gal. In rheological terms, the fluid should have a relatively low plastic viscosity, preferably less than about 50, more preferably less than about 40, and most preferably less than about 30. Another desirable rheological property is yield point, which should be at least about 5, preferably from about 5 to 30 lb/100 ft 2 .
Water-soluble polymers, such as starches, normally are added to brines as dry powders or in a non-hydrating carrier fluid, such as tripropylene glycol. The starches are not prehydrated. The resulting viscosity and filtration control is determined by the interaction of the starch and brine, which in most cases is essentially none at ambient temperature. However, the viscosity may become excessive and even uncontrollable at elevated wellbore temperatures.
According to the present invention, adequate rheological properties and filtration control are attained without heating of a high density brine by forming a precursor polymer dispersion of the water-soluble polymers in a precursor brine before adding the polymers to the final brine. Exposure of the precursor polymer dispersion to temperatures as high as about 150-225° F. before use does not cause the excessive viscosity increase seen when the final brine, itself, is heated to such temperatures before use.
The invention is particularly important to high density brines because the degree of dispersion of dry starch particles, and the subsequent degree of hydration of such particles, is the controlling factor in how the starch performs in a high density brine. Where a brine is high density, e.g., 11.6 lb/gal CaBr 2 , the initial particle dispersion of the starch is limited. As a result, a significant particle size is maintained and the degree of hydration is limited. These limitations are alleviated if the starch is dispersed in the brine in the manner herein described.
Brines that are useful in the present invention can contain substantially any suitable salts, including, but not necessarily limited to salts based on alkaline earth metals, such as calcium salts, magnesium salts, sodium salts, potassium salts, cesium salts, zinc salts, aluminum salts, and lithium salts. With the exception of sodium and potassium, the salt may contain substantially any anions, with preferred anions being less expensive anions including, but not necessarily limited to chlorides, bromides, formates, propionates, sulfates, acetates, and nitrates. For sodium and potassium, the anion preferably should not be chloride. A preferred brine for forming the prehydrating mixture contains between about 3.5-6.0 lb/gal of calcium bromide.
Although the invention is particularly useful for prehydrating starches, prehydration also should improve the effectiveness of other water-soluble polymers used in brines. As used herein, the term “water-soluble polymers” is defined to mean polymers that are capable of viscosifying the brine and/or providing filtration control for the brine. Such polymers are known in the art. Preferred polymers are non-toxic polymers which include, but are not necessarily limited to water-soluble starches and derivatized versions thereof, water soluble gums and derivatized versions thereof, and water-soluble celluloses, and derivatives thereof. Starches that are suitable for use in the present invention include, but are not necessarily limited to corn based and potato based starches, preferred starches being more temperature stable starches. Gums that are suitable for use in the present invention include, but are not necessarily limited to xanthan gums, wellan gums, scleroglucan gums, and guar gums. The foregoing water-soluble polymers are widely available from commercial sources.
As used herein, the term “derivatized starches” refers to starches and gums that have been derivatized in a manner that renders them inherently non-fermentable in order to avoid the need for a preservative. Water-soluble “derivatized starches” that should operate successfully as water-soluble polymers in brines include, but are not necessarily limited to: hydroxyalkyl starches and gums; starch and gum esters; cross-link starches and gums; hypochlorite oxidized starches and gums; starch and gum phosphate monoesters; cationic starches and gums; starch and gum xanthates; and, dialdehyde starches and gums. These derivatized starches and gums can be manufactured using known means, such as those set forth in detail in Chapter X of Starch: Chemistry and Technology 311-388 (Roy L. Whistler, et al. eds., 1984), incorporated herein by reference.
Specific examples of suitable derivatized starches that fall within the foregoing categories include, but are not necessarily limited to: carboxymethyl starches; hydroxyethyl starches; hydroxypropyl starches; hydroxybutyl starches; carboxymethylhydroxyethyl starches; carboxymethylhydroxypropyl starches; carboxymethylhydroxybutyl starches; polyacrylamide starches; and, other starch copolymers.
A preferred water-soluble polymer is a derivatized starch known as BIOPAQ, available from Baker Hughes, Inteq. Both derivatized and non-derivatized starches and gums hereinafter will be referred to as “starches.” Unless otherwise specified, the term “starch” or “starches” refers to both derivatized and non-derivatized starches and gums.
In order to prepare the precursor polymer dispersion, between about 0.5-4 lb/gal, preferably between about 1-2 lb/gal of a desired water-soluble polymer is mixed with a brine having a density of between about 9-14 lb/gal, preferably between about 11-13 lb/gal. In a preferred embodiment, about 5 pounds of BIOPAQ is mixed with about 4.2 gallons of calcium bromide brine having a density of about 11.6 lb/gal. In a preferred method, the starch is added to the brine continuously and uniformly while stirring vigorously, e.g., using a paddle mixer at about 300-400 rpm. The starch should be added as quickly as possible before the fluid viscosity increases dramatically; however, slugging in of the starch should be avoided. The resulting dispersion preferably should be pourable at ambient temperature. It may be necessary to subject the dispersion to high shear to improve pourability. Dispersions so prepared should have adequate rheological and filtration control properties even after exposure to aging temperatures of up to about 150-225° F.
The addition of this precursor polymer dispersion to the actual brine will result in a density decrease if the brine density is more than 11.6 lb/gal of salt. The starting brine density will need to be adjusted accordingly, so that the final fluid density is within specification.
The invention will be better understood with reference to the following examples, which are intended to be illustrative only and should not be interpreted as limiting the invention:
EXAMPLE I
A high density brine prepared using a precursor polymer dispersion of the present invention (FLUID A) was compared to a the same brine prepared using a portion of the dry powdered polymer (FLUID B). The following materials were used to make the brines:
FLUID A FLUID B 13.2 lb/gal CaCl 2 —CaBr 2 Brine 289 cc 324 cc Attapulgite 5 g 5 g MgO 3 g 3 g Milcarb (Calcium Carbonate) 50 g 50 g BIOPAQ/Brine Dispersion 119.1 g BIOPAQ (powder) 8 g
The resulting brines exhibited the following properties:
FLUID A
FLUID B
AFTER
AGING
AFTER AGING
INITIAL
AT 200° F.
INITIAL
AT 200° F.
600 rpm
69
79
44
280
300 rpm
45
46
26
198
200 rpm
35
34
19.5
162
100 rpm
24
22
12
120
6 rpm
6.5
7
3.5
47
3 rpm
6
6.5
3
41
PV, cp
24
33
18
82
YP, lb/100
21
13
8
116
sq. ft.
API Filtrate,
0.1
2.3
70/15
0
cc
min.
The rheological properties of FLUID A did not change significantly after heat aging at 200° F. and the filtration control was satisfactory before and after heat aging.
The initial yield point (YP) of FLUID B was borderline as to providing sufficient suspension properties and increased to excessive values in plastic viscosity and yield point after heat aging. The filtration control of FLUID B also was unsatisfactory upon initial preparation, as evidenced by the API Filtrate results. The reason for using a higher starch concentration in FLUID B was to improve the initial properties, but the higher starch concentration did not provide adequate improvement.
EXAMPLE II
The following precursor polymer dispersions were prepared:
Calcium Chloride/Calcium Bromide Brine Dispersion Formulations
1
2
3
4
5
6
CaCl 2 /CaBr 2 , bbl
1
1
1
1
1
1
Density, ppg
11.6
12
12.5
13
13.5
14
BIOPAQ, ppb
50
50
50
50
50
50
XCD*, ppb
5
*XCD polymer was obtained from Kelco Rotary, San Diego, California.
The foregoing precursor polymer, dispersions then were used to prepare brines as shown below. All formulations were mixed in 1 bbl equivalents at 6500 rpms for 30 minutes at high shear. All components were added at the beginning of the mix time:
Brine Formulations 1 2 3 4 5 6 CaCl 2 /CaBr 2 , bbl 0.8 0.8 0.8 0.8 0.8 0.8 Density, ppg 13.2 13.2 13.2 13.2 13.2 13.2 Dispersion, gpb 5 5 5 5 5 3.4 Dispersion # 1 2 3 4 5 6
The resulting brines exhibited the following properties before and after heat aging, respectively:
Initial Properties
600, rpm
63
53
65
53
69
48
300, rpm
37
30
36
30
40
27
6, rpm
4
1
4
1
4
1
3, rpm
3
0
3
1
3
1
PV, cp
26
23
29
23
29
21
YP
11
7
7
7
11
6
lb/100 ft 2
API,
0.1
0.1
0.1
0.5
0.2
0.4
cc/30 min
Heat Aged Properties, 16 hr @ 225° F.
600, rpm
129
125
130
117
140
158
300, rpm
77
75
80
70
87
98
6, rpm
6
5
6
3
7
7
3, rpm
5
3
6
3
7
7
PV, cp
52
50
50
47
53
60
YP,
25
25
30
23
34
38
lb/100 ft 2
API,
3.2
0.1
0.1
0.1
0.1
0.1
cc/30 min
The rheological properties were satisfactory after heat aging at 225° F. and the filtration control was excellent before and after heat aging (Note that the precursor polymer dispersion prepared in CaCl 2 /CaBr 2 brine was not as effective in building initial rheology as the precursor polymer prepared in CaBr 2 brine, but filtration control properties were quite satisfactory).
Many modifications and variations may be made to the embodiments described herein without departing from the spirit of the present invention. The embodiments described herein are illustrative only should not be construed as limiting the scope of the present invention. | A method for producing a precursor polymer dispersion for addition to a brine for use in drilling and completion operations comprising providing a precursor brine having a first salt content, and mixing a water-soluble polymer with the precursor brine at a sufficient concentration and under conditions sufficient to produce a precursor polymer dispersion effective at a sufficient concentration in a final brine having a second salt content to improve the rheology and/or fluid loss control properties of the final brine. | 8 |
BACKGROUND OF THE INVENTION
The oxidative cleavage of phenols, catechols and orthobenzoquinones with a reagent prepared from cuprous chloride, oxygen, pyridine and methanol is known. The product is the monomethyl ester of cis,cis muconic acid. The dimethyl ester of cis,cis muconic acid has also been prepared. It has been disclosed that monoesters can also be prepared by reacting catechols and 4-tert-butyl-1,2-benzoquinone with a copper (II) reagent generated from oxygen, cuprous chloride in pyridine and any of the following alcohols: methanol, ethanol, n-butyl alcohol and isopropyl alcohol.
BRIEF DESCRIPTION OF THE INVENTION
The present invention includes a copper (II) reagent prepared by reacting an alcohol selected from the group consisting of phenol and alkanediols of 2-6 carbons with a paired spin copper oxide having equimolar amounts of copper and oxygen and showing no absorption by Electron Spin Resonance, said copper (II) reagent having a relative minnimum in the visible spectrum of about 565 nm and a relative maximum in the visible spectrum of about 730 nm.
The present invention also includes a method of producing muconic acid monoesters which comprises reacting a cyclic starting material selected from the group consisting of phenols of the formula ##STR1## catechols of the formula ##STR2## and orthobenzoquinones of the formula ##STR3## where R is H, alkyl, alkoxy, bromo, chloro, amino, phenyl or phenoxy with the above copper reagent and recovering the muconic monoester of said alcohol.
The present invention also includes as a composition of matter a monoester of a muconic acid and an alcohol selected from the group consisting of phenol and alkanediols of 2-6 carbons.
DETAILED DESCRIPTION OF THE INVENTION
The copper reagent of the present invention can be prepared as the product of reaction between a selected alcohol and a certain copper oxide. The copper oxide can, in turn, be produced by a variety of previously disclosed processes and by processes first disclosed herein. First, the oxidation of cuprous chloride with oxygen has been known to produce a reagent which, when combined with methanol, is active in cleaving cyclic starting materials such as catechol and phenol. Preparations in which this active reagent is found are believed to produce first a certain paired spin cyclic copper oxide and then, from reaction of methanol with the copper oxide, an active species thought of as cupric methoxy hydroxide. The evidence supporting this theory is described in our article at pages 5472-5487 of the Aug. 16, 1978 issue of Journal of the American Chemical Society. The paired spin copper oxide may also be prepared by oxidizing copper metal with oxygen in the presence of at least catalytic amounts of cuprous or cupric chloride (collectively copper chloride). Fine copper powder is slowly and continuously added, as is oxygen gas, to the copper chloride in an inert solvent such as pyridine. Since the copper chloride is not consumed, but instead the net reaction is one of converting the copper metal to the copper oxide, one can prepare a solution in increasing copper oxide/copper chloride ratios with increasing time. By contrast, the oxidation of cuprous chloride in pyridine produces a mixture of cupric chloride (as a pyridine complex) and the copper oxide in which substantially 50% of the copper is in each species, according to the following stoichiometry: ##STR4## wherein py 2 CuCl 2 represents the same cupric pyridine complex formed by dissolving cupric chloride in pyridine and the latter structure represents the paired spin copper oxide used in the present invention. This oxide is characterized by an equimolar content of oxygen and copper (as computed from the observed stoichiometry) but cannot be observed in Electron Spin Resonance spectroscopy. While copper (I) is diamagentic and hence would not be observed by Electron Spin Resonance, the evidence (including acid hydrolysis of the oxide to cupric oxide) strongly suggests a copper (II) state in which copper atoms with opposite net spins are closely paired either as a tight di-u-oxo bridged copper (II) dimer, oligomer or a polymer. When formed in pyridine, this copper oxide is solvated or complexed by pyridine.
Any copper oxide having the above characteristics and which can react with methanol to form a reagent capable of cleaving catechol to cis,cis muconic acid monoester is suitable as a starting material in preparing the present copper reagents. It is preferred, however, that lower alcohols such as methanol, ethanol, isopropyl alcohol and n-butyl alcohol not be present while preparing the present copper reagents, as such alcohols complete with the diols and phenol of the present invention in reacting with the paired copper oxide.
The following reactions summarize some of the work reported in our August 16, 1978 article establishing that the copper chloride is not the active cleavage reagent: ##STR5## The same "CuMe reagent" can be prepared by adding methanol after consumption of oxygen or by adding water to (pyCuClOMe) 2 . Any of the "CuMe reagent", the "CuO solution" and the resuspended brown-black solid are active to cleave catechol to form cis,cis muconic acid monomethyl ester. Neither the bispyridine cupric chloride recovered by filtration and resuspended, nor fresh bispyridine cupric chloride in pyridine, nor fresh bispyridine cupric chloride plus methanol was effective to cleave catechol, the former two giving no reaction and the latter giving 4,5-dimethoxy-1,2-benzoquinone.
Many of the methods so described are unpreferred in the present invention since methanol is present during formation of the paired spin copper oxide and will form the "CuMe reagent" competitively with the formation of the active copper (II) higher alcohol reagent.
Higher alcohols suitable for preparation of the present copper reagents include phenol and alkanediols of 2-6 carbons such as ethylene diol, 1,2 propanediol, 1,2-butanediol, 1,4-butanediol, 1,2-hexanediol and other diols of the formula HO--R--OH where R is straight or branched alkane of 2-6 carbons.
Cyclic starting materials suitable in the present invention include phenol, catechol and orthobenzoquinone. Monosubstituted forms of these three cyclic materials are also included with the substitutent being alkyl, alkoxy, bromo, chloro, amino, phenyl or phenoxy. In the case of alkyl or alkoxy substituents straight or branched chain alkyl groups of 1-6 carbons are preferred.
As in the case of the oxidation of phenols in the presence of other copper reagents, oxygen must be present during the reaction if a phenol cyclic starting material is used. No oxygen is required in the case of catechol and benzoquinone cyclic starting materials provided that excess copper reagent is used. Otherwise the conditions for the cleavage reaction are not critical and are as described in our Aug. 18, 1978 article.
The products of the cleavage reaction are novel muconic acid monoesters of the formula: ##STR6## where R is as described above, R' is phenyl or HO--R"--, with R" being alkyl of 2-6 carbons. It will be appreciated that these acids may exist after reaction as copper salts, but may be recovered by acid hydrolysis and then separation from the remaining components by extraction with a suitable solvent or by a suitable form of chromatography.
These monoesters are themselves useful as comonomers, being polymerizable at both the unsaturation sites and the free acid site. Furthermore, upon hydrogenation with H 2 and Raney nickel (or other known catalyst), these monoesters can, in cases where R is hydrogen, be converted to adipic acid esters of the formula
HOOC--(CH.sub.2).sub.4 --COOR'
where R' is as described above and can, in cases where R is not hydrogen, be converted to acid esters of the formula HOOC--(CH 2 ) 3 (CHR)--COOR' where R and R' are as described above and the placement of (CHR) among (CH 2 ) groups is determined by the position of R on the muconic acid ester. Such adipic and other acid esters are desirable as chain terminators for polyamides such as nylon-6 and nylon-66, to produce polyamides having a terminal phenyl or hydroxy group. Where R' is phenyl, a good "leaving group" is available for further reaction (as by substitution or crosslinking) at this site on the polymer.
EXAMPLE 1--Muconic Acid Mono(4-hydroxybutyl) Ester from Catechol
A solution of cuprous chloride (2.00 g, 20 mmole) in dry pyridine (60 ml) was stirred under an atmosphere of molecular oxygen until approximately one equivalent (130 ml, 5.8 mmole) of oxygen was consumed in an oxidation reaction with stoichiometric proportions of cuprous chloride:oxygen of 4:1. 1,4-Butanediol (0.90 g, 10 mmole) was added next via syringe followed by the addition of a solution of catechol (0.55 g, 5 mmole) in pyridine (20 ml) over 45 minutes. With stirring an additional 45 minutes, the solution consumed 140 ml (6.25 mmoles) of oxygen. The pyridine was then evaporated and the residue hydrolyzed with 50 ml of 0.2 N aqueous HCl at 0° C. with rapid stirring in the presence of 250 ml of methylene chloride to produce an organic layer from which was recovered 0.25 g (23% yield) of crude muconic acid mono(4-hydroxybutyl) ester, melting point 92°-98° C. This product appeared to be the cis,cis isomer. Triturating with methylene chloride raised the apparent melting point to 107°-110° C. The properties of this product were as follows:
Infrared (nujol mull): 3425 (alcohol OH), 3400-2400 (--CO 2 H), 1720, 1700, 1600, 1242, 1190 cm -1 .
PMR (Acetone-d 6 )δ1.6-1.9 (m, 4H, --CH 2 CH 2 --C--O--), 3.57 (distorted t, J˜6 Hz, 2H, --CH 2 --OH), 4.13 (distorted t, J 6 Hz, 2H, --C(O)--O--CH 2 --), 5.99 (sym m, 2H, ═CH--CH═), 6.13 (b, ˜2H, OH), 7.80 (sym m, 2H, ═CH--C(O)--).
CMR (Acetone-d 6 )δ26.07 (C--CH 2 --C), 29.97 (C--CH 2 --C), 61.91 (CH 2 OH), 65.03 (O═C--O--CH 2 ), 124.89 (═CH--CO 2 R), 125.47 (═CH--CO 2 H), 138.36 (--CH═C--CO--, both beta-vinyl carbons), 166.10 (--CO 2 R), CO 2 H (not observed).
Mass spectroscopy (C.I./NH 3 ): 215 (M+H + ), 232 (M+NH 4 + ).
EXAMPLE 2--Muconic Acid Monophenyl Ester
Cuprous chloride (1.00 g, 10 mmole) was oxidized in dry pyridine (30 ml) as in Example 1. A solution of phenol (0.47 g, 5 mmole) in 150 ml of pyridine was added over 5 minutes. The mixture was stirred for 21.5 hours and 190 ml (8.5 mmole) of molecular oxygen was consumed. After the mixture was thoroughly evaporated in vacuo (30° C., 0.5 mm of mercury pressure), the residue was stirred with diethyl ether (100 ml) and the insoluble copper salts filtered off. Evaporation of the ether gave only pyridine and a trace of phenol.
The mixture of copper salts from the filtration were then stirred with 250 ml of methylene chloride at 0° C., and 50 ml of 2 N HCl was added over 30 minutes. The organic layer was dried with magnesium sulfate and the solvent evaporated off to give 0.60 g of tan solid shown by nuclear magnetic resonance spectroscopy and gas chromatography analyses to be about 80% muconic acid monophenyl ester or an approximate 88% yield based on 100% conversion of phenol. The crude product also contained about 1% of an unidentified species with molecular weight of 190 and about 12% of another compound identified as 4-phenoxymuconic acid monophenyl ester. Muconic acid monophenyl ester, purified by recrystallizing the crude product from toluene and vacuum sublimation (100° C./0.05 mm of mercury) has a melting point of 126°-127° C. and the following properties:
C 12 H 10 O 4 . Calculated: C, 66.05; H, 4.62. Found: C, 65.83; H, 4.65.
Infrared (nujol): 3500-2200, 1735, 1690, 1635, 1604, 1586, 1336, 878 and 683.
Mass Spectroscopy (C.I./CH 4 ) 219 (M+H + ), 247 (M+C 2 H 5 + ) CH 3 CN.
Ultraviolet MAX :263 nm (ε22,700).
PMR (CDCl 3 )δ: 6.07 (d,J=11.5 Hz, 1H, ═CH--CO 2 H), 6.35 (d,J=15.8 Hz,1H,═CH--CO 2 Ar), 6.83 (d,J=11.5 Hz,1H, --CH═CH--CO 2 H), ˜6.9-7.8 (m, 5H,--Ar), 8.57 (d of d, J˜12 Hz, 15.8 Hz,1H,--CH═CH--CO 2 Ar), 10.17 (bs, 1H, --CO 2 H).
CMR (CDCl 3 )δ: 121.47, 128.99, 129.39 and 150.59 (--Ar), 124.49 (═C--CO 2 Ar), 125.96 (═C--CO 2 H), 139.80 (--C═CCO 2 Ar), 142.35 (--C═C--CO 2 H), 164.35 (--CO 2 Ar), 170.50 (--CO 2 H).
The 4-phenoxymuconic acid monophenyl ester was purified by column chromatographic separation using Sephadex LH-20/methyl acetate and had a melting point of 162°-172° C. (short white needles) and was characterized by ultraviolet, infrared, PMR, CMR, element analysis and mass spectroscopy (M.W. 311 for M+H + ).
EXAMPLE 3
Example 2 was repeated with 0.33 g (3.33 mmole) cuprous chloride in pyridine and 0.156 g (1.66 mmole) phenol in pyridine (total pyridine 100 ml) except that the phenol was added to the oxidized copper chloride with magnetic stirring in a glass lined reactor under an initial oxygen pressure of 60 psig (5 atmospheres). After four and one half hours there was no further pressure drop. Isolation and analysis as in Example 2 indicated a 76% yield of muconic acid monophenyl ester and 9-10% yield of 4-phenoxymuconic acid monophenyl ester at 94% conversion of phenol. | Muconic acid monoesters of alkanediols of 2-6 carbons and of phenol are prepared by copper (II) oxidative cleavage of phenols, catechols or orthobenzoquinones. The products are useful as comonomers in polyamides and other polymers. The alkanediol or phenol is introduced into the copper (II) reactant or catalyst. | 2 |
RELATED APPLICATION
[0001] In accordance with 35 U.S.C. § 119, this application claims the benefit of GB Application No. 0810239.4 filed on Jun. 5, 2008.
BACKGROUND
[0002] This invention relates to a device for the detection of water and in particular to a low-cost device for monitoring water use.
[0003] The efficient use of water is an important environmental and economic consideration. Domestic water usage, and in particular wastage, is an area in which education of consumers may lead to a significant reduction in water usage.
[0004] Domestic water users rarely have an appreciation of their usage of water, and in particular wastage of water due to taps running when the water is not being used. For example, it is common for a tap to be left running while a person brushes their teeth, even though no use is made of the water. Wastage of hot water is more significant than of cold water as not only is the water lost, but also the energy spent heating that water.
[0005] Although notifying the public about the importance of conserving water is partially successful, a greater awareness of the issue is required to create a significant change in consumer's behaviour.
[0006] There is therefore a need for an efficient means of highlighting water wastage to the public.
SUMMARY
[0007] The following presents a simplified summary of the disclosure in order to provide a basic understanding to the reader. This summary is not an extensive overview of the disclosure and it does not identify key/critical elements of the invention or delineate the scope of the invention. Its sole purpose is to present some concepts disclosed herein in a simplified form as a prelude to the more detailed description that is presented later.
[0008] There is provided an apparatus for indicating a volume of liquid flow, comprising a liquid sensor for sensing the presence of a liquid, a timer activated when the liquid sensor indicates the presence of a liquid, a calculator to calculate the volume of liquid flow dependent upon the time for which the timer is activated, and an indicator to provide an indication of the volume of fluid calculated by the calculation means.
[0009] There is also provided a method of calibrating a water measurement apparatus, comprising the steps of starting a timer in the apparatus, dispensing a predetermined volume of water at a typical flow-rate from the water outlet in conjunction with which the apparatus will be utilised, stopping the timer when the predetermined volume of water has been dispensed, and calibrating the apparatus utilising the time taken to dispense the predetermined volume of water.
[0010] Various optional features are described herein and in the claims of this application.
DESCRIPTION OF THE DRAWINGS
[0011] Embodiments of the present invention will now be further described, by way of example, with reference to the drawings, wherein:
[0012] FIG. 1 shows an embodiment of a device configured to be positioned in a sink for measuring and indicating water volume;
[0013] FIG. 2 shows a schematic diagram of a device for measuring water volume;
[0014] FIG. 3 shows a further embodiment of a device configured to be positioned in a sink for measuring and indicating water volume;
[0015] FIG. 4 shows an embodiment of a device configured to be attached to a tap for measuring and indicating water volume flowing out of that tap;
[0016] FIG. 5 shows a further embodiment of a device configured to be attached to a tap for measuring and indicating water volume flowing out of that tap; and
[0017] FIG. 6 shows schematic diagrams of suitable liquid sensors.
DETAILED DESCRIPTION
[0018] The detailed description provided below in connection with the appended drawings is intended as a description of the present examples and is not intended to represent the only forms in which the present example may be constructed or utilized. The description sets forth the functions of the example and the sequence of steps for constructing and operating the example. However, the same or equivalent functions and sequences may be accomplished by different examples.
[0019] Although publishing information on water wastage brings the problem to people's attention, the current invention realises that a more effective way of causing consumers to reduce wastage would be to draw that wastage to the consumer's attention at the time the waste occurs. Accordingly, the current invention provides a device for indicating water usage in a domestic environment. Various embodiments are described, for example for detecting water usage at the tap or at the outlet of the sink. An embodiment provides a device for positioning in a sink which detects and indicates water flow to a person using that sink. Embodiments of the invention may provide an indication of water volume flowing out of the sink, or may provide an alert each time certain quantities of water pass out of the sink. In order to encourage the user to fill a sink, rather than to work under a running tap and allow water to run away, the device's alerts may cease or change when it is detected that the sink is being filled.
[0020] FIG. 1 shows an embodiment of a device 1 for detecting water flow out of an outlet of a sink. The body of the device 1 is a generally smooth ovoid shape, such that the device will naturally slide to the lowest point in the sink in which it is disposed. The device is thus most likely to locate itself close to the outlet of the sink, thereby ensuring water flowing out of the sink is detected. A more spherical shape would allow the device to roll to the lowest point of the sink.
[0021] A liquid sensor is located on the device to detect liquid when it is in contact with the sensor. The sensor may be of any suitable type and particularly relevant options are discussed below. The device is provided with a indicator 2 for displaying an indication of water volume detected by the device. In the embodiment shown in FIG. 1 , the display is a set of LEDs, but any suitable means may be utilised, for example a number display or bar-graph. In the embodiment shown in FIG. 1 each LED may be configured to illuminate in turn when a predefined volume of water is detected.
[0022] FIG. 2 shows a schematic diagram of a device shown in FIG. 1 . The liquid sensor 20 is connected to a processing system 21 configured to respond to detection of liquid by the sensor 20 . The processing system 21 comprises a counter 22 which counts while liquid is detected and thus provides an indication of the quantity of water that has been detected by the device. The counter 22 is started by the detection of water by the sensor 20 , and stopped when water is no longer detected by the sensor 20 . By calibration of the speed of counting to water flow-rate the counter 22 can be configured to provide an indication of water volume. A display 23 is connected to the processing system 21 and controlled to indicate the volume of liquid detected.
[0023] The processing system 21 may be provided by a microcontroller or similar processing device, suitably programmed to perform the required functions. Alternatively, discrete logic devices may be utilised.
[0024] FIG. 3 shows an embodiment of the device comprising a numerical and graphical indication of water volume.
[0025] The detection device may comprise more than one liquid sensor, each disposed at a different position on the body of the device. Embodiments may be designed to roll or slide to the lowest point of the sink, and thus the orientation of the device in its working position is not known. The provision of more than one sensor can be utilised to ensure that whatever the orientation of the device, one of the sensors will be exposed to liquid flowing out of the sink and the device will therefore be activated. The device may also comprise more than one indicator, such that the indicator will be visible regardless of the orientation of the device in the sink. The indicator may also be provided by the whole device, or a substantial portion of the device, illuminating.
[0026] The provision of more than one sensor may also allow the device to distinguish between water flowing directly out of the sink, and water that is being held in the sink due to the closure of the outlet. When water is flowing directly out of the sink, the water level will generally be very low, and thus only the sensors located at the lowest points of the device will detect the liquid. However, when the sink is being filled the water level will increase and the liquid will be detected by more than one of the sensors. It is one intention of the device to encourage users to fill sinks rather than utilise a running tap, and therefore the indication provided by the device may change when it is detected that the sink is being filled. For example, the indication of volume may stop increasing, or the colour of the indicator may change from a first warning colour to a second colour indicating that the correct action is being taken.
[0027] In an alternative embodiment the outer body of the device may be provided with openings such that liquid can enter the device. The liquid sensors may be located within the outer body and are thus protected from contact with other items, for example the sink in which the device is disposed. Contact of the liquid sensors with an object may cause activation of the sensors and hence inaccurate measurement of liquid flow. Location of the sensors within the body may thus increase the accuracy of the device. The electronic system is adequately packaged, for example by encapsulation, to prevent any damage by contact with the liquid.
[0028] In alternative embodiments a body shape which is designed to stay in one place may be utilised rather than the rolling-shape described above. For example, a cuboid body may be utilised and the device would then be positioned in the preferred location by the user. Such a device may also be provided with an attachment means to secure it in the desired location. Other than the body shape, the features described hereinbefore are equally applicable to this embodiment. A further embodiment utilises a tripod or other multi-legged shape such that the device rests in a defined position. The liquid sensors may be mounted in any suitable position on the legs or body of the device. The legs may be arranged such that the device is stable when positioned in a sink with a sloping side. The display may be positioned on the top of the device such that it can be easily viewed, or as described previously the body or legs may form the indicator.
[0029] In an alternative embodiment, the liquid sensor is mounted on an extension of the device, which extension is configured to extend into the plug hole or outlet of the sink, such that it protrudes below the plug. The extension may be constructed to be thin, such that the plug can still seal the outlet, in spite of the extension. The liquid sensor in this embodiment is only exposed to liquid when it is running out of the sink, and therefore a more accurate indication of wasted water may be gained. One or more liquid sensors may also be provided on the body of the device for operation in conjunction with the liquid sensor positioned in the outlet. The sensor on the body may be positioned such that it only detects liquid once it has reached a reasonable depth and thus indicates the sink is filling. Such a pair of sensors may allow discrimination between water flowing through the outlet due to an emptying of a sink of water and water being allowed to flow directly out of the sink. In the former case liquid will be detected by both sensors. The latter is more likely to indicate wasted water and the device may be configured to only monitor such flow.
[0030] Sensors may also be provided to detect when the device is in contact with the bottom of the sink, or when it is floating, such that an alternative method of detecting when the sink is filling is provided.
[0031] FIG. 4 shows an embodiment 40 for mounting on the outlet of a tap. This embodiment monitors the flow of water into the sink, rather than out of it. The device has an attachment means for attaching to a variety of designs of tap, and a sensor 41 which protrudes into the water flow to detect the presence of water. When water is detected by the sensor 41 , the device records and indicates volumes as described hereinbefore. In an alternative embodiment, water may be sensed using an optical sensor, so that no contact with the water is required. Such a sensor may be advantageous as any material brought into contact with water which may be consumed must meet rigorous safety standards. The optical sensor may operate in a reflective or transmissive mode.
[0032] FIG. 5 shows an alternative device utilising a hook-and-loop fastening strap to attach the device to the tap. The device is also provided with a solar panel such that the device can be powered without requiring batteries.
[0033] A method of calibration is also provided such that the accuracy of the device can be improved. To calibrate the device, it is set to a calibration mode and a predetermined volume of water is measured out of the tap. The device measures the time taken for that predetermined volume to be dispensed and utilises that time to calibrate measurements. When the calibration is performed, the tap is set to a typical flow-rate, and it is then assumed that the flow rate of the tap is consistent with that calibration flow-rate. Although the flow-rate in use will not always be a precise match for the calibration flow-rate, it has been shown to be sufficiently close to provide useful data. Furthermore, even if no calibration is performed, typical flow-rates of taps are relatively consistent and therefore the devices can be pre-calibrated for an average flow-rate that the device is likely to be utilised with.
[0034] The device may be supplied in a container that can be utilised to measure the predetermined volume of water for the calibration process. The liquid sensors may be utilised to change the mode of the device and to indicate when the predetermined volume measurements starts and stops.
[0035] A temperature sensor may also be provided in the device to detect the temperature of liquid coming in contact with the device. The device may be configured to monitor and/or indicate differently depending on the temperature of the water. For example, the device may therefore be configured to alert the user more rapidly when hot water is detected, or a specific indication may be provided that the water detected is hot (i.e. above a certain predefined temperature).
[0036] A capacitive sensor may be particularly appropriate for use as the liquid sensor. FIG. 6 shows two embodiments of capacitive sensors that may be utilised to detect liquid. In each sensor the presence of liquid modifies the electrical properties of the capacitor. That change is detected and utilised to indicate a presence of liquid.
[0037] The word ‘sink’ is used herein as a generic term to indicate any vessel into which water may be directed from a water outlet. References to sink are therefore intended to include other specific items such as baths and shower trays. Similarly, the term ‘tap’ is used to indicate any form of water outlet and accordingly encompasses items such as shower heads.
[0038] The methods described herein may be performed by software in machine readable form on a storage medium.
[0039] Any range or device value given herein may be extended or altered without losing the effect sought, as will be apparent to the skilled person.
[0040] It will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. It will further be understood that reference to ‘an’ item refers to one or more of those items.
[0041] The steps of the methods described herein may be carried out in any suitable order, or simultaneously where appropriate. Aspects of any of the examples described above may be combined with aspects of any of the other examples described to form further examples without losing the effect sought.
[0042] It will be understood that the above description of a preferred embodiment is given by way of example only and that various modifications may be made by those skilled in the art. The above specification, examples and data provide a complete description of the structure and use of exemplary embodiments of the invention. Although various embodiments of the invention have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the scope of this invention. | An apparatus for indicating a volume of liquid flow, comprising a liquid sensor for sensing the presence of a liquid, a timer activated when the liquid sensor indicates the presence of a liquid, a calculator to calculate the volume of liquid flow dependent upon the time for which the timer is activated, and an indicator to provide an indication of the volume of fluid calculated by the calculation means | 8 |
FIELD OF THE INVENTION
[0001] The present invention relates to a transmission method and system using a standard transmission network for connecting elements of a seismic device, allowing to transmit with precision a signal indicative of a time break.
[0002] The transmission system according to the invention can find applications in many fields where distant stations have to be synchronized without necessarily using dedicated communication means.
BACKGROUND OF THE INVENTION
[0003] This is the case in the field of seismic prospecting where signals received by seismic receivers distributed on the ground surface for example and reflected by the discontinuities of the subsoil in response to the emission of seismic waves by a vibrational or impulsive source are recorded. Seismic data collection sets comprising a large number of acquisition units distributed on the site to be explored and suited to collect (amplify, filter, digitize and store) the signals are used. The stored data are transmitted to a central control and recording station from each acquisition unit at fixed time intervals (for example after each emission-reception cycle, after each daily session, etc.) or <<with the current>>, as soon as a transmission time interval is available, either directly or via intermediate stations or concentrators. Seismic acquisition systems are for example described in patents FR-2,511,772 (U.S. Pat. No. 4,583,206) or FR-2,538,194 (U.S. Pat. No. 4,628,494), FR-2,666,946 (U.S. Pat. No. 5,245,647), FR-2,692,384 (U.S. Pat. No. 5,550,787), FR-2,696,839 (U.S. Pat. No. 5,706,250), FR-2,710,757 (U.S. Pat. No. 5,563,847), FR-2,720,518 (U.S. Pat. No. 5,822,273), FR-2,766,580.
[0004] It is important that all the acquisition units distributed on the site explored can be synchronized with a common time break, generally the time of triggering of the seismic source, whatever the distance from the central station that transmits the indicative signal thereto and whatever the transmission channel used therefore, failing which the centralized data combinations become very imprecise.
[0005] There are well-known methods and devices allowing perfect readjustment in time of distant stations to a central station communicating by means of communication channels, provided that it has been possible to measure the time of propagation of the signals on these channels.
[0006] Patent FR-2,538,194 (U.S. Pat. No. 4,628,494) filed by the applicant describes for example a method for synchronizing the acquisition of seismic signals by an acquisition unit in the field with a time break such as the time (TB) of triggering of a seismic source in the case where the time of propagation Δt thereto of the signal indicative of this time, via a transmission channel such as a cable or a radio channel, is known. The method essentially consists in sending a pre-signal initiating the acquisition of the signals coming from the seismic receivers and their storage in a local memory. When the synchronization signal subsequently emitted is received by the acquisition unit at a time t, all the samples stored from the time (t−Δt), i.e. the time break, are sought in the local memory. Patent application FR-98/15,792 describes a method and a device also allowing to produce, for each seismic signal, a series of samples of these signals, re-staggered from a time break, from a first series of digitized samples of this seismic signal produced from any time break prior to the time break, knowing the effective time interval between these two times. The method comprises determining coefficients of a digital filter likely to compensate for the fractional part of the effective time interval measured, and applying this digital compensation filter to the first series of samples, thus allowing to obtain a series of digitized samples re-staggered from the time break.
[0007] However, these known locating and readjustment techniques are applicable only if the time of propagation of synchronization signals through the emitting and receiving stations is known with precision, transfers being managed by software means, notably within the scope of multitask management, especially if one considers that the uncertainty about the effective propagation time in a seismic transmission system as mentioned above for example should not exceed about 50 μs.
[0008] Transmission without more or less random time lag is possible and easier to implement when one owns the network that is used and if one is in control of the form of the signals emitted and of the coding mode. When the TB signal indicating the effective time of emission by the source reaches the central station, it is possible, via suitable circuits, to inject this signal directly into the communication channel that connects it to the receiving station, and thus to prevent possible non-constant delays due to the station management information system.
[0009] Standard communication networks are advantageous. They allow high-rate transmissions, they are relatively simple to use and open-ended. They however work according to a particular communication protocol with specialized pilot and control circuits which one has to adapt to in order to transmit signals representative of time breaks with precision.
[0010] This is the case in the system described in patent application FR-99/12,113 filed by the applicant, which uses a standard communication network of Ethernet type for example in order to connect a central control and seismic recording station to dependent stations: local intermediate control and concentration stations, local acquisition units, and to transmit a synchronization signal (TB) thereto. The time of transit of the data on the transmission channels between the central station and the acquisition units being measured beforehand, acquisition of the seismic data by the acquisition units is preinitiated, the retention time interval in relation to the time of reception of the synchronization signal being fixed and greater than the transit time. An adjusted compensation delay is applied to the synchronization signal in the intermediate station in order to take into account the fluctuations of the effective transfer time linked with its passage through multitask control means of the intermediate stations and the transmission network so as to respect the retention time interval. All the acquisition units can thus be perfectly synchronized.
[0011] This method is quite suitable when the time of transit via the transmission channel is constant and can be measured beforehand, which is the case with a standard communication network comprising material links (low-rate wired Ethernet network for example).
[0012] On the other hand, in any other case where the time of transit on the available channel of the standard network (radio link for example) is likely to fluctuate within a time interval incompatible with the precision required for transmission of a synchronization signal such as a TB, the compensation means of the prior system are inadequate.
SUMMARY OF THE INVENTION
[0013] The transmission method according to the invention allows to use a standard communication network for transferring synchronization data between a central control and seismic recording station and dependent stations (local seismic data acquisition, processing and transmission units depending on the central station either directly or via one or more intermediate local control and concentration stations, itself connected to local acquisition units), in all the cases where the transmission time on the connection channels between the elements may be liable to too great fluctuations.
[0014] In its principle, the solution retained essentially consists in providing the communicating stations with a common time reference that can be delivered for example by signals picked up by receivers and transmitted by a satellite positioning network of a well-known type such as the GPS system or the carrier frequency of a Hertzian emitter, and in using this common reference to calculate the real transmission time and to locally readjust the seismic acquisition time break.
[0015] The transmission method according to the invention allows to transfer, via a standard communication network (LAN), a synchronization signal indicating a time break (TB) between a central control and seismic recording station (CCU) and seismic signal acquisition and storage units (RTU) distributed in the field, when the time of transit of the synchronization signal through at least part of the connection channels of the standard network between the central station and at least one dependent station (which can be an intermediate station (RRS), itself connected by cables or fibers to acquisition units in the field (RTU) or possibly each acquisition unit in configurations where they directly controlled by the central station) may be liable to fluctuations within a determined fluctuation margin.
[0016] The method comprises:
[0017] a learning stage including formation of a specific frame and storage thereof by each station, and detection in each said dependent station of signals delivered by a clock exterior to the device,
[0018] pre-initiation of the acquisition of seismic data by acquisition units (RTU) with a retention time interval in relation to the time of reception of synchronization signal (TB) which is fixed and greater than the maximum transit time, considering the fluctuation margin,
[0019] first precise dating of time break (TB) from the external clock and transmission of the data obtained with this first dating in form of the specific frame to the dependent stations,
[0020] detection of the time of arrival, in each dependent station, of the specific frame and second dating of this time of arrival from the external clock, and
[0021] measurement of the effective transit time equal to the time interval between the data associated with the first dating and those associated with the second dating, and consequently readjustment of the time break to the seismic data stored in acquisition units (RTU).
[0022] The pre-initiation time is for example the time of transmission to a seismic source (S) of a fire order.
[0023] In the case where the (or each) dependent station is a local station (RRS) connected to at least one acquisition unit (RTU) by a material link with a fixed transit time, and to central station (CCU) by a fluctuating transit time link, a readjustment to the seismic data stored in acquisition units (RTU) is applied by taking into account the fixed transit time.
[0024] The method comprises for example:
[0025] direct detection, in central station (CCU), of synchronization signal (TB),
[0026] formation, from the synchronization signal detected, of the specific frame and direct application thereof to an interface module (TCI) of central station (CCU),
[0027] detection, in an interface module (TCI) of each dependent station, of a specific frame of synchronization signal (TB), and
[0028] application, to synchronization signal (TB) of the dependent station, of a time lag equal to the measured transit time.
[0029] The method is particularly flexible since it allows, by means of an adjustable transmission delay time compensation, to easily take into account the various data transfer rates of the transmission channels available in a complex transmission system as used for example in modern seismic prospecting devices.
[0030] The transmission system according to the invention allows to transfer, by means of a standard communication network (LAN), a synchronization signal indicating a time break (TB) between a central control and seismic recording station (CCU) and seismic data acquisition and storage units (RTU) distributed in the field, when the time of transit of the synchronization signal through at least part of the connection channels of the standard network between the central station and at least one dependent station may be liable to fluctuations within a determined fluctuation margin. The system comprises:
[0031] means for forming a specific frame, storage means allowing each element of the seismic device to store this specific frame, and a local clock (RXGPS) controlled by synchronization signals provided by said external clock (H) in order to generate a dating time scale, this local clock being associated with the elements of the seismic device,
[0032] means for pre-initiating, in acquisition units (RTU), acquisition of the seismic data with a retention time interval in relation to the time of reception of synchronization signal (TB) that is fixed and greater than the maximum transit time, considering the fluctuation margin,
[0033] counting means associated with each local clock so as to perform a first precise dating of time break (TB) in accordance with the external clock and transmission means for transmitting the data obtained with this first dating in form of the specific frame to the dependent stations,
[0034] means for detecting the time of arrival, at each dependent station, of the specific frame and counting means associated with the local clock for performing a second dating of the time of arrival in accordance with external clock (H), and
[0035] counting means for determining the effective transit time equal to the time interval between the data associated with the first dating and those associated with the second dating, and means for accordingly readjusting the time break to the seismic data stored in acquisition units (RTU).
[0036] The system comprises for example an interface set (TBG/I) in central station (CCU) for directly generating on a transmission channel, to each dependent station, a frame carrying the data from the first dating, an interface set (TBD/I) for decoding said specific frame, counting means (D-CPT) for performing the second dating in accordance with external clock (H) and for determining the effective transit time of the synchronization signals.
[0037] In the case where the (or each) terminal station is a local station (RRS), it comprises a generator (SYNCTB-G) for generating a signal (SYNCTB) synchronous with the delayed signal to acquisition units (RTU).
[0038] The common external clock consists for example of synchronization signals emitted by a satellite positioning system, each element of the seismic device comprising a suitable detection module.
[0039] The common external clock can also consist for example of synchronization signals emitted by a Hertzian transmitter, each element of the seismic device comprising a suitable detection module.
[0040] This combination of a fixed retention time applied by all the acquisition units and of intermediate delay adjustment means suited to complete the propagation times measured on the transmission channels by reference to an external clock allows all the acquisition units to be adjusted together to the same time break.
[0041] Whether the time of transmission by the network is known with precision or not, it is possible to combine such a network with conventional dedicated transmission channels using optical fibers, radio or cable links, while maintaining a perfect synchronism between these various channels.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] Other features and advantages of the method and of the system according to the invention will be clear from reading the description hereafter of a non limitative example, with reference to the accompanying drawings wherein:
[0043] [0043]FIG. 1 diagrammatically shows a seismic device positioned in the field with various transmission channel possibilities between the elements,
[0044] [0044]FIG. 2 diagrammatically shows a local concentration station RRS,
[0045] [0045]FIG. 3 diagrammatically shows general central station CCU,
[0046] [0046]FIG. 4 diagrammatically shows a concentration module DCU inside a local station RRS,
[0047] [0047]FIG. 5 is a block diagram showing the progress, in central station CCU, of the operations of emission of synchronization signal TB,
[0048] [0048]FIG. 6 is a block diagram showing the progress, in a local station RRS, of the operations of reception and delay adjustment of synchronization signal TB,
[0049] [0049]FIG. 7 diagrammatically shows an interface circuit TBI adjustable, as the case may be, to the detection or the generation of a frame characterizing the synchronization signal, and
[0050] [0050]FIG. 8 is a general block diagram of the software management of the functions fulfilled by a local station.
DETAILED DESCRIPTION
[0051] The method and the system according to the invention will be described within the particular scope of an application to a seismic prospecting device already described notably in patents FR-2,692,384, FR-2,696,239 and FR-2,720,518 already mentioned above.
I) Seismic Device
[0052] The seismic device comprises (FIG. 1) an often considerable series (several hundreds to several thousands) of seismic receivers R producing each a <<seismic trace>>in response to the transmission in the ground of seismic waves produced by a source S coupled with the ground and reflected by discontinuities of the subsoil. Receivers R are subdivided into n groups GR 1 , GR 2 , . . . , GRn, comprising each a certain number q of receivers R. Local acquisition and transmission units RTU referenced BA 11 , . . . , BApk, . . . , BApn, similar for example to those described in patent FR-2,720,518 mentioned above, are placed in the field, each one for digitizing and temporarily storing the seismic data collected by one or more receivers R of each group. Any group GRk of order k for example comprises a certain number q of receivers respectively connected to p local acquisition units RTU referenced BA 1 k, BApk for example. Numbers p and q can be different if at least part of the local units RTU (BAp 2 for example in FIG. 1) is intended to collect the seismic data coming from more than one seismic receiver R. The seismic device can thus comprise for example several hundred local units RTU.
[0053] The various groups of acquisition units RTU are respectively controlled by local control and concentration stations RRS referenced RRS 1 , RRS 2 , . . . , RRSi, . . . , RRSk, . . . , RRSn. These local stations are equipped to fulfil extensive functions:
[0054] control the acquisition units RTU of their respective groups,
[0055] collect the seismic data (seismic traces) of the various units RTU, store them in a mass memory (one or more disks for example),
[0056] transfer on request to central station CCU at least part of the data stored: either parameters indicative of the proper operation of the acquisition units or of the local stations (RRS), or at least a part, possibly compressed, of each seismic trace, in order to carry out a quality control,
[0057] manage test and initialization operations on the connection means (Hertzian channels or lines) and on the field equipment (seismic receivers, electronic devices in each acquisition unit RTU), check the progress of seismic operations, and inform on request of the results and possible anomalies.
[0058] The various concentrators RRS, like source S, are controlled by a central control and recording station CCU where all the seismic data are finally grouped together. Local stations RRS communicate with central station CCU via a local network LAN of a well-known type (Ethernet™ for example) comprising material links (cable or optical fiber L) or radio links RF 1 , RF 2 , . . . RF n , this network working according to a specific transmission protocol.
II) Local Control and Concentration Stations (RRS)
[0059] Each local station RRS comprises (FIG. 2) a central unit CPU with an extended RAM memory (32 Mo for example), communicating by means of an internal bus BUS with a mass memory MM of several Go, and a concentration unit DCU (see FIG. 4) for managing the communications of each local station RRS with local acquisition units RTU, either by means of Hertzian channels F kj and/or by transmission cables or lines Ci.
[0060] An interface set NCI is also connected to internal bus BUS. Network LAN comprising one or more lines L and/or radio transmission channels RFB, used for communication with central unit CCU, is connected to interface set NCI by means of a channel switch SW. An interface TBI intended for detection, on network LAN, of the signals indicative of the time break when seismic source S is triggered, is connected to interface set NCI on the one hand and to internal bus BUS on the other. The functionalities of elements NCI and TBI are described below in connection with FIGS. 5 and 6.
III) Central Control Station CCU
[0061] Central station CCU also comprises a central-unit CPU provided with an extended RAM memory communicating by means of an internal bus BUS with a mass memory MM of high capacity, sufficient for storage of the seismic traces transmitted by the acquisition units via control and concentration units RRS. It also comprises a local dialogue terminal UI for the operator; a printer PR allowing high-definition printing of seismic sections, maps, etc., is connected to internal bus BUS by an interface card DI. A high-capacity mass memory DB for storing a database consisting of seismic data, geographic data, etc., is also connected to internal bus BUS. An image scanner ISC used to enter into the database of memory DB possibly a geographic map of the zone where seismic operations are carried out is also connected to this bus by means of an interface element. Such an image of the zone of operations can be used to match the points of installation of the field pickups with precise geographic coordinates.
[0062] Seismic source S is controlled by a control box SC forming, when triggered, an indicative signal TB that is applied to central unit CCU by means of an interface card SCI.
[0063] An interface set NCI specifically suited to control network LAN is also connected to internal bus BUS. Local network LAN (lines L and/or radio transmission channels Rfi) used for connection with each local station RRS is connected to interface set NCI by means of a channel switch SW. An interface circuit TBI is interposed in parallel between interface elements NCI and SCI. The functionalities of elements NCI and TBI are described below in connection with FIGS. 5, 6 and 7 .
[0064] Concentration module DCU of each local station RRS (FIG. 4) is intended to relay the transmission of the commands of control unit CPU to local stations RRS and, conversely, the reception of the seismic data. It comprises two electronic cards. A first card carries a set CiV whose functions will be described in connection with FIG. 5, a synchronous line detection circuit LSD that communicates through input/output ports P with one or more transmission lines Ci for communication with acquisition units RTU in the field (FIG. 1). A second card carries memory modules FM with DMA, accessible by means of an internal bus DMAB. Interface circuit FOI allows exchanges between exchange bus DMAB and central unit CPU (FIG. 2), by means of internal bus BUS. The first three cards CPU, LSD, FM communicate by means of an internal bus PB.
[0065] Each concentration unit DCU comprises a radio emission-reception unit CRTU similar to the unit described in patent FR-2,720,518 mentioned above, which is suited, when this mode of connection is established, to establish communications by Hertzian channel with local units RTU. This unit CRTU comprises (FIG. 4) an interface circuit RI connected to exchange bus DMAB, to internal bus BUS and to a radio transmitter Tx emitting for example in the TFM (Tamed Frequency Modulation) mode well-known to specialists, and a synchronous Hertzian modulation detection circuit RSD connected to a radio receiver Rx.
IV) Programming Activities by Tasks
[0066] As also described in the aforementioned patent FR-2,720,518, the various activities allowing proper progress of the processes are divided into catalogued tasks, each dedicated to a specific process and each in the form of programmes integrated in the computers in central station CCU 1 , in local stations RRS and local units RTU.
[0067] The tasks can be carried out sequentially or concurrently via switches. A real-time distribution programme manages the start or the interruption of tasks by taking into account their respective priority degrees or their resumption when they have been interrupted a) when all the required data were no available at a time of their execution, or b) upon reception of an interrupt message from another task, or c) as a result of an exterior event.
[0068] Definition of a task requires taking into account its function, all the data required for its execution, the required control programs (drivers), all the interruptions imposed by the task and the pre-established priority degree thereof.
[0069] The tasks can have access to a database consisting of parameters entered by the operator, of the acquired seismic data and of the seismic system control parameters.
[0070] Interdependence relations of the various tasks fulfilled by each local control and concentration station RRS for example are shown in the diagram of FIG. 8.
V) Transmission of Synchronization Signal TB by Local Network LAN
[0071] Repetitive transmission, without delay, to the dependent stations (local intermediate stations RRS or directly to acquisition units RTU in the case where they are directly connected to central station CCU), of signal TB indicative of the precise time of triggering of source S (time of firing) is performed by respecting the following procedures:
[0072] No traffic takes place on all of network LAN when firing is initiated.
[0073] If the effective time of transit of the signals on each transmission channel of network LAN between central station CCU and the dependent stations is constant and reproducible: cable link, optical fiber link, etc., it is measured with precision once and for all when connecting each dependent station to network LAN, as described in the aforementioned patent application FR-99/12,113.
[0074] If the effective transit time of these signals is fluctuating but below a known limit value: case of wireless connections for example, one uses clock signals provided by an external time reference accessible to all the elements of the seismic device (dating system), accessible where the seismic operations are carried out, as described hereafter.
[0075] These signals can be, for example, clock signals emitted at regular intervals (every second for example) by a positioning system such as the GPS (Global Positioning System) system or synchronization signals emitted by a radio station and adjusted to an atomic clock, these synchronization signals being picked up by specialized receivers associated with the elements of the seismic device.
[0076] Emission of signal TB of local stations RRS on the cables connecting them to acquisition units RTU in the configuration shown in FIG. 1 is retarded by a known fixed delay. This delay, which takes into account all the transit times in the transmission system and the allowable fluctuation margins, is known by acquisition units RTU.
[0077] When signal TB is received by acquisition boxes RTU, acquisition of the seismic signal has already started before with a starting presignal (pre-TB). As already described in patent FR-2,666,946, the acquired seismic samples are stored in a buffer memory of acquisition units RTU whose size is sufficient to contain all the samples acquired during a time interval between the presignal and the first sample to be held, acquired after the reference time break.
[0078] This time interval is conventionally selected greater than the maximum time of propagation of the signals on the physical transmission channels used while remaining compatible with the size of the buffer memories. Since the real transmission time of the synchronization signal is likely to fluctuate when multitask microcomputers or various transmission means: optical fibers, Hertzian channels or cables, are used, the method will comprise, if necessary, applying intermediate adjustable delays (by using retarding counters) intended to complete the intangible delays (propagation times measured once and for all when the seismic device is installed in the field) or the delays measured by reference to a common time scale, so that all the acquisition units RTU are synchronous with the time break after this time interval.
V-1) In Central Station CCU
[0079] Dating or timing of events is based on the recognition of a particular frame emitted, which requires a prior learning stage. Reference frame FRAME-TB is emitted by the central station and stored in set TBG/I of interface TBI. It is this frame that will afterwards be emitted upon reception of synchronization signal TB indicating the start of the seismic acquisition.
[0080] The prior learning stage of the reference frame, whatever the form thereof in the specific transmission protocol, allows to adapt automatically to any possible change in the stantard network LAN used.
[0081] The progress of the firing sequence operations in the station is as follows:
[0082] Operator O initiates the seismic shooting (FIG. 5) and the corresponding signal F is sent to a task TB of central station CCU.
[0083] A pre-initiation signal is transmitted through network LAN to local stations RRS which transmit it to acquisition units RTU. Upon reception of this signal, the acquisition units start acquiring the signals coming from the receivers in the field and store them in a buffer memory.
[0084] Task TB emits a signal F that is relayed to source S through its control box SC, thus causing its initiation.
[0085] This initiation time is signalled to central station CCU by a signal TB.
[0086] Signal TB is sent to an interruption controller IT-C in interface module SCI, which leads to the interruption of the task in progress and an interruption signal IT-TB is taken into account nearly immediately. Task TB takes signal IT-TB into account in order to control the proper progress of the operations. Control box SC simultaneously produces a signal GEN-FRAME-TB. Interface circuit TBI comprises a set TBG/I connected to network LAN between network control interface NCI and switch SW and suited to generate a frame TB-FRAME therein (see FIG. 7).
[0087] The receiver of the GPS positioning system producing signals at intervals of the order of one second, a dating or timing counter supplied by a 1-MHz internal clock for example, intended to provide an intermediate time scale (1 μs period), is associated therewith, which allows to date any event occurring in each interval. The emission of each GPS signal initializes the dating counter. The value displayed by counter TBDATE is stored upon reception of signal GEN-FRAME-TB.
[0088] Upon reception of signal GEN-FRAME-TB, value TBDATE of the dating counter is inserted into reference frame FRAME-TB and transmitted without delay to the dependent stations: acquisition units or intermediate stations.
V-2) In local stations RRS
[0089] Interface TBD/I (of the type described in FIG. 7) is connected to network LAN between switch SW and network control interface NCI to detect the specific frame of the TB. Set DCU in each local station RRS comprises, in set CiV (FIG. 4), a delay time counter D-CPT and a generator SYNCTB-G producing a frame signal synchronous with signal TB.
[0090] Task RXTB (FIG. 6) initializes counter D-CPT with the predetermined fixed delay greater than the propagation time through all the connection channels used.
[0091] The learning stage is similar to that described for the central station.
[0092] From the reception of frame Pre-TB, frame detection interface TB monitors the traffic on the physical link in order to detect frame TB.
[0093] As soon as frame TB is detected, interface TBD/I takes the value from dating counter TBDATE 1 in station RRS, extracts value TBDATE from the frame and subtracts it from TBDATE 1 . The value obtained is applied to counter D-CPT in order to adjust the emission delay of signal SYNCTB emitted towards acquisition units RTU. Signal FRAME-TB-REC then starts counter D-CPT.
[0094] The end of counting of counter D-CPT causes the emission of a signal TX-SYNC to a circuit SYNCTB-G in the DCU, which generates a signal SYNCTB that is then effectively transmitted to acquisition boxes. When counter D-CPT is stopped, a signal IT-TB-EM is emitted towards task RXTB to indicate the end of processing of TB.
[0095] The DCU also comprises a counter (not shown) allowing to delimit a time slot (signal T-LATE) after which, if no TB signal is detected, the waiting procedure in progress is cancelled.
[0096] The organization of the tasks in each local station RRS is shown in FIG. 8. The various abbreviations used to designate the elements and the tasks respectively mean:
[0097] DRVETH: local network driver;
[0098] DRVCRT: console driver;
[0099] TSKTB: TB task;
[0100] TSKSEQ : sequencing task;
[0101] TSKTRACE : seismic trace storage task in a mass memory;
[0102] TSKFORM: field equipment installation control task;
[0103] TSKTEST : test task;
[0104] TSKREAD: data reading task;
[0105] TSKCMD: command emission task;
[0106] DRVTFM: radio reception driver;
[0107] DRVHDB3: reception on lines driver;
[0108] DRVCMD: command emission driver;
[0109] DRSSTATUS: status driver, and
[0110] DRVRADIO: radio link driver.
[0111] Embodiments where standard network LAN is used for connecting the central station to the intermediate stations have been described. The same technique could of course be used without departing from the scope of the invention in cases where the dependent stations on network LAN are acquisition units RTU.
[0112] It is also clear that the technique of measuring the delay with which synchronization signal TB is taken into account and the adjustable transmission delay compensation can be applied if a network referred to as owner network is used instead of a standard LAN type network. | Method and system for transferring synchronization data between a central control and seismic recording station and dependent stations in all the cases where the time of transmission through the connection channels between the elements may be liable to too great fluctuations.
In its principle, the solution retained essentially consists in providing the communicating stations: a central station (CCU) and intermediate local control and concentration stations (RRS), themselves connected to local acquisition units (RTU), with a common time reference or clock (H) (that can for example be provided by a satellite positioning network of a well-known type such as the GPS system, or based on the carrier frequency of a Hertzian transmitter) which is picked up by specialized receivers associated with the elements of the seismic device, and in using this common reference to calculate the real transmission time and to locally readjust seismic acquisition units (RTU).
Application: transmission of a TB concomitant with the triggering of a seismic source (S) for example. | 6 |
TECHNICAL FIELD
[0001] This disclosure relates to precisely controlled solid state thermite reaction compositions and incorporation of those compositions into an integrated heating device for various applications such as heating of prepared foods or beverages in their containers.
BACKGROUND
[0002] Situations arise in which it would be convenient to have a distributed means of providing heat in circumstances where heating appliances are not available. For example, producers of prepared foods have indicated that there could be significant market potential for self-heating food packaging (SHFP) systems that could heat prepared foods in their containers to serving temperature, simply, safely, and efficiently.
[0003] For a mass consumer SHFP product, safety is paramount and should be inherent; preferably there should be no extreme temperatures, no fire, no smoke or fumes under anticipated use and abuse conditions. Practical considerations mandate that any system be reasonably compact and lightweight with respect to the food to be heated. Thus, the system should have a good specific energy and high efficiency. The system must also be capable of extended storage without significant loss of function or accidental activation of the heater. There should be some simple means of activating the heating component of the system, after which the required heat load should be delivered efficiently within a specified time period, perhaps just a few minutes. Operation must be very reliable with low failure rates in millions of units of production. For a single use food application, material components should be food-safe, low-cost, environmentally friendly and recyclable.
[0004] The only SHFP technology currently in the consumer market uses an onboard system for mixing separated compartments of quicklime and water, yielding an exothermic heat of solution. These products are bulky (literally doubling package size and weight), complex, unreliable, costly, and have achieved very low market penetration. There have also been reported instances of the heater solution leaking and coming into contact with food or consumers.
[0005] An exothermic reaction in which the component reactants could be premixed yet be inert until such time as the user initiates the reaction would be beneficial in terms of providing for a simpler, more compact, and low cost package design. A solid state reaction system could offer advantage over wet chemical systems since solid systems will be less prone to spill or leak.
[0006] Thermites are a class of exothermic solid-state reactions in which a metal fuel reacts with an oxide to form the more thermodynamically stable metal oxide and the elemental form of the original oxide. Thermites are formulated as a mechanical mix of the reactant powders in the desired stoichiometric ratio. The powders may be compressed into a unitary mass. These compact reactions generate substantial heat, with system temperatures that can reach several thousand degrees, often high enough to melt one or more of the reagents involved in the reaction. However, thermite reactions typically require a very high activation energy (e.g., welding thermites [Al/FeO x ] are ignited with a burning magnesium ribbon). Thus, a thermite reagent composition can be formulated to be quite stable to prevent inadvertent initiation due to electrostatic shock or mechanical impact. This generally inert character is an advantage in storage and transportation.
[0007] The most widely known thermite system is the Al/FeO x system described in Table 1. Once initiated, this system reacts virtually instantaneously to generate molten iron and is in fact used for welding rail lines. The only other significant known applications of thermites are in pyrotechnics and military weapons technologies. “A Survey of Combustible Metals, Thermites, and Intermetallics for Pyrotechnic Applications,” S. H. Fischer, M. C. Grubelich, Proc. Of 32 nd AIAA/ASME/SAE/ASEE Joint Propulsion Conference (1996) and “Thermite Reactions: their utilization in the synthesis and processing of materials,” L. L. Wang, Z. A. Munir, Y. M. Maximov, Journal of Material Science 28(14), 3693-3708 (1993) provide useful surveys of various classes of solid state reactions including thermites.
[0000]
TABLE 1
Characteristics of FeO x /Al and SiO2/Al Thermite Reactions
Adiabatic
Gas
Heat of
Reaction
production
Density
reaction
Temperature
(moles of gas
Reaction
(g cm −3 )
(kJ g −1 )
(K)
State of Products
per 100 g)
2Al + Fe 2 O 3 →
4.175
3.95
3135
molten Al 2 O 3 slag
0.1404
2Fe + Al 2 O 3
(2862° C.)
Fe (liq./gas)
8Al + 3Fe 3 O 4 →
4.264
3.67
3135
Molten Al 2 O 3 slag
0.0549
9Fe + 4Al 2 O 3
(2862° C.)
Fe (liq./gas)
4Al + 3SiO 2 →
2.668
2.15
1889
solid Al 2 O 3
0
3Si + 2Al 2 O 3
(1616° C.)
Si (liq.)
[0008] Since thermite reactions are generally vigorous with intense heat, they have not yet been successfully adapted for moderate-temperature consumer applications. Therefore, it would be highly beneficial to harness the energy release from a kinetically moderated thermite reaction thus transforming a reaction with generally pyrotechnic character to a precisely controlled power source for thermal energy and to then integrate that thermal energy into a heating device for consumer applications.
SUMMARY
[0009] A solid state thermite reaction composition is provided comprising a fuel component, a primary oxidizer, one or more initiating oxidizers and a thermal diluent. The composition can be further comprised of a fluxing agent. The composition can also further be comprised of a high energy oxidizer.
[0010] According to another aspect, a heating device is provided comprising a heating chamber for receiving and storing a substance to be heated having at least two walls, a reaction chamber affixed to a wall of the heating chamber, a solid state thermite reaction composition located within the reaction chamber and an actuatable trigger mechanism affixed to the reaction chamber such that the trigger mechanism is in contact with the reaction composition. The reaction composition is inert until the trigger mechanism is actuated and wherein the reaction composition is isolated from the substance to be heated.
[0011] According to another aspect, a solid-state thermite reaction activation mechanism is provided comprising a first compound substantially in contact with a thermite reaction fuel, a second compound and a removable barrier located between the first and second compounds preventing any contact between the first and second compounds. When the barrier is removed, the first and second compounds contact one another and generate heat sufficient to initiate a thermite reaction using the thermite reaction fuel. Although not specifically described herein, other aspects will be apparent to those of ordinary skill in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] To understand the present invention, it will now be described by way of example, with reference to the accompanying drawings in which:
[0013] FIG. 1 is a perspective cross-sectional view of an illustrative embodiment of a food packaging application with an integrated solid-state thermite heating element;
[0014] FIG. 2 is a perspective cross-sectional view of the heating element depicted in FIG. 1 ;
[0015] FIG. 3 is a side cross-sectional view of another illustrative embodiment of a food packaging application with an integrated solid-state thermite heating element;
[0016] FIG. 4 is a side cross-sectional view of an illustrative embodiment of a re-useable bowl with a port to removably insert a solid-state thermite heating element;
[0017] FIG. 5 is a side cross-sectional view of the embodiment of FIG. 4 with a re-useable activation mechanism removably attached;
[0018] FIG. 6 is a perspective cross-sectional view of a solid-state thermite activation mechanism with a tear-off seal;
[0019] FIG. 7 is a perspective cross-sectional view of a solid-state thermite activation mechanism with a foil barrier and foil piercing element;
[0020] FIG. 8 is a side cross-sectional view of a solid-state thermite activation mechanism with a membrane coated with activation reagents on both sides;
[0021] FIG. 9 is a side cross-sectional view of a solid-state thermite activation mechanism with a peizoelectric spark ignitor;
[0022] FIG. 10 is a graphical depiction of a least squares fit of thermite reaction flame position versus time data;
[0023] FIG. 11 is a graphical depiction of calorimetry data of solid-state thermite reactions.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0024] While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated.
[0025] Food safety and cost are two primary considerations in the selection of potential materials for use in the illustrative embodiments described herein. The Al/FeO x and Al/SiO 2 thermites described in Table 1 involve only abundant, low-cost, food-safe materials and are therefore in this regard good candidates for SHFP. However, those of ordinary skill in the art will understand that many different materials could be selected without departing from the novel scope of the present invention.
[0026] Table 1 compares various characteristics of Al/FeO x and Al/SiO 2 thermite systems. In both cases aluminum is the fuel, with either FeO x or SiO 2 as oxidizer. However the reaction character of the two systems are distinctly different. The high heat of reaction (3.8 kJ g −1 ) of the Al/FeO x thermite leads to an adiabatic reaction temperature of over 3000 K (well above the melting point of both metals: T M, Fe =1809 K, T M, Al =933 K), with excess heat generating gases that can spew molten reaction product. The heat of reaction for Al/SiO 2 thermite is somewhat lower (2.15 kJ g −1 ) leading to an adiabatic reaction temperature of only 1889 K. This temperature is insufficient to melt the alumina slag formed during reaction. This slag acts as a thickening barrier to mass transfer in this type of system, and thus, thermal losses at the reaction front can quench the Al/SiO 2 thermite reaction.
[0027] The rate-limiting step in thermite reactions is typically diffusion of material to the reaction zone. Accordingly, heat transfer and mass transfer are closely coupled in determining reaction rate. Thermite kinetics are typically modeled as a combustion system in which a solid flame front moves through preheat, reaction and quench zones. For reaction self-propagation to occur, the heat generated in the reaction zone must trigger reaction ahead of the wave front. The parameter used to quantify reaction rate of thermites is combustion wave speed. These can range anywhere from approximately 1 m s −1 for conventional thermites to greater than 1000 m s −1 for superthermites based on nanoscale powdered reactants.
[0028] While reasonably exothermic, the Al/SiO 2 system is inherently both non-detonative and self-extinguishing. Based on this more controlled reaction character, this system comprises the foundation of the moderated thermite composition of the embodiments of the present invention described herein. In one embodiment the foundational solid state chemistry is modulated via a combination of physical and chemical reaction modifiers to prepare Al/SiO 2 thermite fuel formulations that are inherently self-regulating at an optimal bounded temperature and give high utilization of the chemical energy content of the reaction materials at the requisite rate of heating.
[0029] Another aspect of these embodiments is maximization of energy content in the solid thermite composition. “Mixed” thermites can be prepared, for example using a combination of oxidizers, and, as shown in Table 1, substituting any portion of the SiO 2 oxidizer with FeO x to create a ternary system, which can beneficially increase the specific energy content of the system from approximately 2 to 4 kJ g −1 depending on FeO x content. Aluminum, SiO 2 , and iron oxides are readily available in various commercial powder grades with food grade purity.
[0030] Factors that can be altered to adjust the reaction rate and combustion temperature of thermite systems include: particle size of reactants, composition, diluent (inert) additives, pre-combustion density, ambient pressure and temperature and physical and chemical stability of reactants.
[0031] Because mass diffusion is the rate controlling step for thermites and diffusion-controlled reactions are inherently slower than temperature dependent chemical kinetics, increasing the diffusion coefficient or reducing the diffusion length between fuel and oxidizer species within an energetic composite can be used to accelerate the reaction rate. Particle shape can be highly influential. Spherical particles can be undesirable if they are too reactive and result in excessive burn rates. Thin and flat-shaped particles can be more ideal for moderate temperature reactions. For efficient thermite fuel utilization, the solid-state reaction must be self-sustaining throughout its volume and there should not be extensive un-reacted regions. Those of ordinary skill in the art will understand that the degree and intimacy of mixing between the silica, aluminum, and additive constituents can be altered to satisfy a myriad of desired outcome parameters without departing from the novel scope of the present invention.
[0032] In a preferred embodiment of an Al/SiO 2 thermite fuel formulation as shown in Table 2 below, the thermite fuel is an aluminum flake. In order to achieve an appropriate balance of reactive surface area and relatively low thermal conductivity to reduce combustion rate, a portion of the silica used is fumed silica, which is in fact an agglomerated nanoparticulate that is easily dispersed into mixtures. Certain materials can act as a “coolant” to lower the burning temperature of the mixture and/or slow down the reaction rate. Other additives can act as binders or stabilizers to regulate mass and heat transfer. Accordingly, in a particular embodiment, a nanoscale clay material is used as a thermal buffer to moderate temperature. Other materials may be used as well.
[0033] In order to render self-sustaining character to the Al/SiO 2 system while operating at lower temperatures, an accelerant is incorporated to reduce the activation energy for the reaction or enable a lower energy reaction path. For example, as shown in Table 2, potassium chlorate, a strong oxidizer is used as an accelerant. Those of ordinary skill in the art will understand that there are many other possible chemical accelerants that could be incorporated without departing from the novel scope of the present invention. Further, the high boiling point, inert salt calcium fluoride is provided as a fluxing agent to increase the fluidity of the reacting system and thereby facilitate mass transport.
[0000]
TABLE 2
Compositions in Weight Percent for Examples
Example I
Example II
Component
Function
(BC03A04)
(BC12A02)
Flaked Aluminum
Fuel component
17.9%
17.3%
powder
(Toyal America 5621)
KClO 3
Initiating oxidizer
14.3%
13.8%
(Sigma-Aldrich 31247)
SiO 2 −325 mesh
Oxidizer, dense
17.9%
13.0%
(Sigma-Aldrich
form
342890)
Fumed silica
Oxidizer, high
3.5%
3.5%
(Sigma-S5130)
surface area form
CaF 2
Fluxing agent
10.7%
10.4%
(Sigma-Aldrich 31247)
Bentonite nanoclay
Thermal Diluent
35.7%
34.3%
(Aldrich 682659)
Fe 2 O 3 <5 micron
High energy
0%
7.7%
(Sigma-Aldrich 31247)
oxidizer
[0034] The exemplary thermite fuel compositions described above were tested to determine their specific energy and reaction rate as follows:
EXAMPLE I
Specific Energy and Reaction Rate Determination on a Moderated Al/SiO2 Thermite—Initiated by Hot Wire
[0035] An approximately 30 g batch of the formulation in column 3 of Table 2 is prepared using the following steps. The powdered components are all first sieved through a 60-mesh screen and weighed in correct proportions into a mill jar. They are mixed in the jar by tumbling on a roll mill for 30 minutes.
[0036] As discussed previously, the rate of reaction and hence heat generation or power is a key metric for an energetic material in consumer heating applications. Kinetic measurements were made on the Example I material by flame tube experiments in which the energetic material is placed in a Pyrex tube and initiated with a hot wire. A video of the reaction is made and then the position data of the reaction front versus time are least square analyzed to extract reaction propagation velocity. FIG. 10 shows the reaction propagation velocity for the Example I material to be 0.691 mm s −1 . This low combustion rate is significantly below that previously reported for conventional thermite reactions and allows efficient calorimetric heat transfer to take place.
[0037] Calorimetric data was measured on a sample prepared by packing approximately 7 g of the powder mix into an open top cylindrical steel can (14 mm diameter×50.5 mm high). The filled can is held immersed in a stirred beaker containing approximately 120 g of water. A small nichrome wire heating element connected to a current source is placed in contact with the upper surface of the packed powder. Current is passed momentarily to initiate the mix and then switched off. The temperature of the water vs. time is recorded, and the maximum temperature increase is used to calculate the thermal energy transferred to the water. The curve labeled Example I on FIG. 11 shows calorimetric time vs. temperature data on the Example I formulation. With the Example I formulation, it takes less than 2 minutes for the water to reach its peak temperature and deliver an energy content of 1.61 kJ g −1 .
Example II
Specific Energy Determination on a Moderated Al/SiO2 Thermite Containing Fe 2 O 3 —Initiated by Hot Wire
[0038] Example II is prepared in a similar manner and tested as Example I except that some stoichiometric fraction of the SiO 2 in the formulation is replaced by Fe 2 O 3 to yield the formulation given in Column 4 of Table 2. The curve labeled Example II on FIG. 11 shows calorimetric time vs. temperature data on the Example II formulation. The greater specific oxidizing power of the Fe 2 O 3 substituent is evidenced by a higher peak temperature of the water. This corresponds to a transferred energy content of 1.76 kJ g −1 .
[0039] Another embodiment of the present invention is the inclusion of a means for activating a solid-fuel thermite composition. The solid fuel should not be prone to inadvertent activation, yet a simple means of activating the reactive material in the heater at the desired time of use is beneficial.
[0040] In some embodiments, a more complex and costly activation device that is re-useable would couple to disposable heater elements for activation. For example, as shown in FIGS. 4 and 5 , a re-useable container is provided with a re-useable activating device such as a battery powered hot wire or a piezoelectric spark ignitor, as shown in FIG. 9 . Referring to FIG. 4 , a heating bowl 410 is provided with a port 420 to receive heating elements 430 containing a solid-state thermite fuel composition. The heating element 430 is held in place by holding tabs or standoffs 440 . An activation device port 450 is provided on the bottom of the bowl to receive and temporarily attach a thermite activation device. The activation device could be a simple battery and wire device 510 as shown in FIG. 5 . The battery 520 is connected to a wire 530 that can be extended through the activation device port 450 into the thermite fuel composition within the heating element 430 . The battery can be used to send enough current down the wire to initiate a thermite reaction using the thermite fuel composition. In addition, the activation device could be a piezoelectric spark ignitor as shown in FIG. 9 . Those of ordinary skill in the art will understand that many types of activation devices can be employed without departing from the novel scope of the present invention.
[0041] In a particular embodiment that enables the greatest ease of use, a simple, low-cost, small (or even miniature) activation device as a built-in component of the heating device is provided. This embodiment is particularly useful in the disposable food packaging context. For example, as shown in FIGS. 6 , 7 and 8 , the activation device could be comprised of minute quantities of an exothermic A/B chemical couple separated by a partition. When the partition is breached mechanically by a simple action of the user, the reactive A/B components mix into contact with each other as well as with the bulk solid thermite fuel composition. Reaction of the A/B components generates a highly localized hot spot in contact with the fuel composition, thereby initiating its controlled combustion.
[0042] While those of ordinary skill in the art will understand that there are many exothermic couples that can be used, FIGS. 6 , 7 and 8 show three designs that incorporate reagents which produce sufficient heat to activate thermite reactions. FIG. 6 shows a pyrophoric iron/air couple where the removal of an internal seal 610 exposes a small mass of pyrophoric iron 620 , which is in contact with a solid thermite fuel composition 630 , to the surrounding atmosphere. The pyrophoric iron reacts with the air to generate the requisite heat to initiate the thermite reaction.
[0043] A potassium permanganate/glycerin couple, as shown in FIG. 7 , is easily prepared, low-cost and food safe while reliably generating very high temperatures with minute quantities of reagents. FIG. 7 shows an amount of potassium permanganate 710 placed directly onto the thermite fuel composition 720 . An aluminum foil barrier 730 is placed over the potassium permanganate 710 and glycerin 740 is placed onto the foil. A cover 760 made of a malleable material with an integrated piercing member 750 is placed over the entire system. A user can then activate the mechanism by pressing down on the cover 760 thus pushing the piercing member 750 through the foil barrier 730 , allowing the potassium permanganate 710 and glycerin 740 to mix and generate enough heat to initiate the thermite reaction.
[0044] This embodiment is capable of being produced in high volume based on a multi-laminate paper making process in which a thin septum layer is interposed between sheets coated with each reactant as shown in FIG. 8 . As shown in FIG. 8 , the potassium permanganate 810 and glycerin 840 are disposed on either side of a thin membrane 830 . A user can rupture the membrane 830 by applying pressure thus allowing the potassium permanganate 810 and glycerin 840 to mix and contact the thermite fuel composition 820 , thus initiating the desired thermite reaction.
[0045] A still further aspect of the present invention is integration of a heating element comprised of a thermite fuel composition and an activation mechanism into the packaging of a food product to be heated by a consumer. An appropriate design of package can be used in conjunction with the moderated composite fuel formulation to provide for ease of use and additional consumer safety. The solid-state fuel can be integrated into a package in a way that provides for efficient transfer of the heat generated to the material to be heated. To illustrate this aspect of the invention, several illustrative embodiments describing designs for incorporating solid fuel compositions into self-heating food packaging follow.
[0046] FIGS. 1 and 3 show heater component designs that are suited to heating foods with a high fluid content, such as canned soups or beverages. In FIG. 1 , the fuel composite 110 is packed into a metal tube 120 that is formed into the shape of a complete or partial annular ring to provide a heating surface near the bottom of the container 100 while at least one end of the tube is located near the top of the container to allow access for user activation of the device. In the alternative design of FIG. 3 the fuel composite 310 is packed into a cylindrical metal can 320 which is then affixed to the bottom of the container 300 . However, those of ordinary skill in the art will understand that a myriad of heater component shapes can be used without departing from the novel scope of the present invention.
[0047] In both designs, the thin metal wall enclosing the fuel provides excellent heat transfer to the surrounding fluid and the simple constructions are amenable to low cost methods of manufacture. As shown in FIG. 2 , the tube 120 or cylinder 320 can be lined with a ceramic layer 210 to provide more efficient heat transfer through the metal wall. Various means can be provided for closing the open ends of the packed cylinders so that the fuel materials will not come into direct contact with the food. The packed tubing may be held in place by stand-off mechanical contacts 130 , such as for example welded tabs to the interior of the container, so that heat transfers efficiently to the surrounding fluid and heat losses to the exterior food container wall are minimized. The heater elements can be offset from the center in order to facilitate filling, stirring, and spooning material from the container. Those of ordinary skill in the art will understand that numerous methods for attaching or integrating the heating component into the packaging structure are available without departing from the novel scope of the present invention.
[0048] Increased weight and volume of packaging relative to the net food content translates to higher shipping costs and shelf space requirements. Therefore, in order to keep packaging overhead low, a compact SHFP heater device is preferred. However, a compact geometry means less surface area is available for heat transfer, which can be an important consideration in cases where the food to be heated is not readily stirred to provide convective heat transfer. Conductive heat transfer from a small heater to a larger mass of solid or non-stirrable food material will provide inefficient and uneven heating.
[0049] In order to overcome these limitations, the heater element of this invention may be implemented so that the heat it generates raises steam that distributes throughout the package interior and transfers sensible and latent heat (via condensation) to the food. The principle of using a chemical reaction to raise steam for heat transfer is efficiently used in the “flameless ration heaters” (FRH) used by the US Army to heat the “meal ready to eat” (MRE) field ration.
[0050] However, the FRH is a wet system based on mixing magnesium metal powder with water and is not well suited to widespread consumer use, whereas in the present invention, the water to be vaporized is not a component of the dry reaction mixture. Rather a small quantity of water is maintained in contact with the outer surface of the heater. For example, the cylindrical heater design of FIG. 3 could be wrapped in a dampened wicking material or located in a small condensate sump in the base of the package. The combustion characteristics of the heater are designed so that in operation, the exterior surface of the heater maintains a temperature sufficient to vaporize water to steam.
[0051] Applications of the present invention are not limited to the SHFP applications described above. A heating component in accordance with the present invention could be incorporated into a wide array of applications where heating would be desirable such as camping equipment as noted above or gloves for skiiers or mountain climbers.
[0052] Any process descriptions or blocks in figures represented in the figures should be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps in the process, and alternate implementations are included within the scope of the embodiments of the present invention in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those having ordinary skill in the art.
[0053] While the specific embodiments have been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of the invention, and the scope of protection is only limited by the scope of the accompanying claims. | A solid state thermite reaction composition is provided comprising a fuel component, an initiating oxidizer, a primary oxidizer, a fluxing agent and a thermal diluent. According to another aspect, a heating device is provided comprising a heating chamber for receiving and storing a substance to be heated having at least two walls, a reaction chamber affixed to a wall of the heating chamber, a solid state thermite reaction composition located within the reaction chamber and an actuatable trigger mechanism affixed to the reaction chamber such that the trigger mechanism is in contact with the reaction composition. According to another aspect, a solid-state thermite reaction activation mechanism is provided comprising a first compound substantially in contact with a thermite reaction fuel, a second compound and a removable barrier located between the first and second compounds preventing any contact between the first and second compounds. | 5 |
BACKGROUND
The present invention relates generally to a tip assembly for a welding torch and, particularly, to a tip assembly for a wire feed welding system.
A common metal welding technique employs the heat generated by electrical arcing to transition a workpiece to a molten state, followed by addition of metal from a wire or electrode. One technique that employs this arcing principle is wire-feed welding. At its essence, wire-feed welding involves routing welding current from a power source into an electrode that is brought into close proximity with the workpiece. When the electrode is sufficiently close to the work piece, current arcs from the electrode to the workpiece, completing a circuit and generating sufficient heat to melt and weld the workpiece. Often, the electrode is consumed and becomes part of the weld itself. Thus, new wire electrode is advanced, continuously replacing the consumed electrode and maintaining the welding arc. If the welding device is properly adjusted, the wire-feed advancement and arcing cycle progresses smoothly, providing a good weld. One common type of wire-feed welding is metal inert gas or “MIG” welding.
In typical wire-feed systems, wire electrode is directed through a welding cable, into a torch assembly, and, lastly, into a contact tip housed within the nozzle assembly. Electrical current is routed from the cable to the wire electrode through the contact tip. When a trigger on the welding torch is operated, wire electrode is advanced toward the contact tip, at which point current is conducted from the contact tip into the egressing electrode.
Because of its proximity to the weld location, a contact tip is exposed to weld splatter and relatively high-levels of heat. Accordingly, contact tips require more frequent maintenance or replacement than other components of the welding system. To facilitate quick replacement of contact tips, present assemblies include certain “threadless” contact tip assemblies, in which the contact tip is not threaded with respect to the remainder of the torch assembly.
Unfortunately, there are a number of problems associated with existing threadless contact tip designs. As one example, the structures for binding the contact tip in the welding torch can impart bending stresses on the contact tip. As another concern, variations in the distance between the contact tip and the exterior portion of the nozzle, known as the tip-nozzle recess, occur with existing threadless contact tip designs. A consistent tip-recess distance is highly desireable in certain welding applications, especially robotic welding systems. In addition, molten spatter from the weld may deposit on the end of the nozzle, eventually requiring replacement of the nozzle. Consequently, nozzles having a nozzle body and a removable threaded end section have been developed. However, weld spatter may contaminate the threads or the threads may experience galling, requiring a tool, such as a wrench, to remove the threaded end section from the nozzle body.
Furthermore, to prevent the ingress of impurities into the molten weld, a flow a shielding material is typically provided to the weld location when certain types of wire electrode are employed. By way of example, inert shielding gas is routed from a gas source, through a welding cable and welding torch, into a gas-diffuser that delivers the gas to the weld location via a nozzle. Welding systems that employ such shielding materials are often referred to in the industry as gas metal arc welding (GMAW) systems, or MIG systems, as mentioned above.
However, there are certain other types of wire electrodes that are employed without a shielding gas. Accordingly, when employing such “gasless” electrodes, the gas routed into the welding cable is blocked from egressing to the environment. In the past, this meant replacing the components at the terminal end of the welding torch with those that prevent the egress of gas. For example, when using gasless wire electrodes, the diffuser is replaced with a component or components that seat the contact tip, prevent the egress of gas from the cable, and electrically insulate a user from the operating current in the contact tip.
Unfortunately, when a welder desires to use both types of electrode, transitioning between these terminal components can be a time consuming task. Moreover, existing arrangements accommodating the different electrode systems generally require an operator to maintain a relatively large inventory of parts, thus increasing the costs of operation.
Therefore, there exists a need for improved contact tip assemblies for welding devices, particularly for facilitating the transition between gas shielded and gasless welding.
BRIEF DESCRIPTION
In accordance with certain embodiments, the present invention provides a securement member for securing a contact tip to a welding torch assembly. The exemplary securement member has a channel extending axially therethrough, and has an internal shoulder that extending into this channel. This internal shoulder abuts against a shoulder on the contact tip, capturing the contact tip between the shoulder and a seating surface on a diffuser, securing the contact tip in the torch assembly. The contact tip may thereby be securely seated without threading, facilitating quick release and installation. Moreover, the exemplary securement member couples to the diffuser such that the egress of fluid from the diffuser is blocked. This blocking allows a user to leave the diffuser secured to the welding torch when a gasless electrode is in use.
In accordance with certain other embodiments, the present invention provides a family of securement members for securing a contact tip with respect to a welding torch assembly. Each exemplary securement member is configured to engage a diffuser of the welding torch. However, one of the securement members is configured to direct fluids egressing from the diffuser toward a weld location, while the other blocks the egress of fluid from the diffuser. This interchangeability allows the for using essentially the same welding torch assembly for a gas-shielded wire electrode and a gasless wire electrode, leading to cost and time savings.
DRAWINGS
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
FIG. 1 is a diagrammatic representation of a welding system, in accordance with an embodiment of the present invention;
FIG. 2 is a diagrammatic representation of a welding torch assembly for use with the system of FIG. 1 , in accordance with an embodiment of the present invention;
FIG. 3 is an exploded view of an exemplary contact tip securement assembly for the torch assembly shown in FIG. 2 ;
FIG. 4A is a cross-sectional representation taken along line 4 - 4 of FIG. 2 of a contact tip securement assembly for a shielded wire electrode;
FIG. 4B is a cross-section representation taken along line 4 - 4 of FIG. 2 of a contact tip securement assembly for a gasless wire electrode; and
FIG. 5 is a perspective, exploded view of a securement member for the assembly, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
As discussed in detail below, embodiments of the present invention provide a securement member for securing a contact tip with respect to a welding torch assembly. Advantageously, the securement member captures a contact tip to secure it with respect to torch assembly and, moreover, blocks the egress of shielding material from a diffuser to which the securement member is coupled. Accordingly, a welding torch assembly can be quickly adapted for use with a wire electrode that benefits from a shielding material or for use with a gasless wire electrode that does not employ a shielding material.
FIG. 1 illustrates an exemplary wire-feed welding system 10 that incorporates such a securement member. Prior to continuing, however, it is worth noting that the following discussion merely relates to exemplary embodiments of the present technique. As such, the appended claims should not be viewed as limited to those embodiments described herein.
The exemplary welding system 10 includes a welding torch 12 that defines the location of the welding operation with respect to a workpiece 14 . Placement of the welding torch 12 at a location proximate to the workpiece 14 allows electrical current, which is provided by a power source 16 and routed to the welding torch 12 via a welding cable 18 , to arc from the welding torch 12 to the workpiece 14 . In summary, this arcing completes an electrical circuit from the power source 16 , to the welding torch 12 via the welding cable 18 , to a wire electrode, to the workpiece 14 , and, at its conclusion, back to the power source 16 , generally to ground. This arcing generates a relatively large amount of heat causing the workpiece 14 and/or filler metal to transition to a molten state, facilitating the weld.
To produce electrical arcing, the exemplary system 10 includes a wire-feeder 20 that provides a consumable wire electrode to the welding cable 18 and, in turn, to the welding torch 12 . This wire-electrode can be of various types, including traditional wire electrode or gasless wire electrode. As discussed further below, the welding torch 12 conducts electrical current to the wire electrode via a contact tip 20 located in a neck assembly 22 and supported by securement member 24 , leading to arcing between the egressing wire electrode and the workpiece 14 .
To shield the weld area from contaminants during welding, to enhance arc performance, and to improve the resulting weld, the exemplary system 10 includes a shielding material source 26 that feeds an inert, shielding gas to the welding torch 12 via the welding cable 18 . It is worth noting, however, that a variety of shielding materials, including various fluids and particulate solids, may be employed to protect the weld location. However, certain wire electrodes, such as gasless wire electrodes, do not greatly benefit from a shielding material. Accordingly, when such wire electrodes are employed with the present system, a securement member 24 better suited for such electrodes is employed, as discussed further below.
Referring to FIG. 2 , advancement of these welding resources (e.g., welding current, wire electrode, and shielding gas) is effectuated by actuation of a trigger 28 secured to a handle 30 . By depressing the trigger 28 , a switch (not shown) disposed within the trigger is closed, causing the transmission of an electrical signal that commands delivery of the welding resources into the welding cable 18 .
Turning to FIG. 3 and FIGS. 4A and 4B , these figures illustrate a family of securement members 24 A and 24 B. Each securement member is adapted to capture and secure a welding contact tip 20 with respect to a seating location 32 on a diffuser 34 . In the exemplary welding system, the diffuser 34 operates to receive the welding current, wire electrode, and shielding material. During operation, radially extending channels 36 in the diffuser 34 operate to direct shielding gas around an egressing wire electrode. Additionally, the conical shape of the seating location 32 corresponds with the conical shape of the contact tip end 38 , thus facilitating centering and engagement of the contact tip 20 with respect to the diffuser 34 and the welding torch as a whole. Such conically shaped diffusers and contact tips are described in U.S. Pat. No. 6,852,950 that issued on Feb. 8, 2005, and U.S. patent application Ser. No. 10/215,811 that was filed on Aug. 9, 2002, both of which are incorporated herein by reference.
To seat the contact tip 20 with respect to the diffuser 34 , the exemplary contact tip 20 includes a shoulder 40 that extends radially beyond the surface of the remainder of the contact tip 20 . This shoulder 40 is configured to interact with an internal shoulder of either of the securement members 24 A or 24 B. As illustrated, each securement member 24 A and 24 B includes a central channel 42 A and 42 B, respectively, extending axially therethrough. Additionally, each exemplary securement member 24 A and 24 B includes an internal shoulder 44 A and 44 B, respectively, that extends into the respective central channel 42 A and 42 B.
FIGS. 4A and 4B , which are discussed further below, better illustrate the capture of a contact tip 20 between the securement member 24 and the diffuser 34 when the given securement member is threaded onto the diffuser 34 . As generally illustrated in FIG. 3 , the respective internal shoulders 44 A and 44 B are located at a corresponding axial location from an inboard end of the given securement member 24 A and 24 B. Thus, the securement members 24 A and 24 B can be interchangeably used with same contact tip 20 and the same diffuser 34 . In fact, the securement members 24 A and 24 B each have similar counterbores 46 A and 46 B to help seat the securement members 24 A and 24 B with the same diffuser 34 . Moreover, threads 48 A and 48 B on each securement member 24 A and 24 B (see FIGS. 4A and 4B ) are matched, facilitating threaded engagement of the securement members 24 A and 24 B with the same diffuser 34 . Of course, other mechanisms for mechanically coupling the securement members 24 A and 24 B with the diffuser 34 , such as clamps or friction fit arrangements, may be envisaged. In summary, the securement members 24 A and 24 B define a family of securement members that can be interchangeably used with the same diffuser and torch assembly, the interchangeable nature facilitating operation of the welding system 10 with shielded wire electrodes and gasless wire electrodes.
Although there are similarities between the securement members 24 A and 24 B, there are also a number of differences. For example, the larger diameter securement member 24 A is designed for use with a wire electrode that benefits from a shielding gas. Accordingly, when the contact tip 20 is captured between the conical seating surface 32 of the diffuser 34 and the internal shoulder 44 A of the securement member 24 A, a pathway is provided for guiding the shielding material toward the weld location. Specifically, with regard to securement member 24 A, gas is routed through the radially extending diffuser channels 36 , as represented by arrow 50 . This shielding material then enters an interstitial space 52 defined by the exterior of the diffuser 34 and the interior surface of the securement member 24 A, which defines the channel 42 A. It is the inclusion of the interstitial space 52 that at least partially results in the diameter of the exemplary securement member 24 A being slightly larger than exemplary securement member 24 B. The shielding material is routed axially though the interstitial space 52 and into axial ports 54 extending through the internal shoulder 44 A. Subsequently, the shielding material is routed toward the weld location by the interior surface of the securement member 24 A, at the conclusion of which the shielding materials egresses from the member 24 A, shielding the egressing wire electrode. As illustrated, arrows 56 represent the flow of shielding material axially through the channel 42 A of the securement member 24 A.
Along with shielding material, the diffuser 34 also facilitates the routing of electrical current to the contact tip 20 and, ultimately, to the egressing wire electrode. This transmission of current is facilitated by the fact that the exemplary diffuser 34 and the contact tip 20 are formed of a conductive material, such as copper. To insulate the current-carrying members of the assembly, the exemplary securement member 24 A includes an insulative layer 60 that insulates the exposed external surface of the securement member from the possibly electrically conductive internal surfaces of the securement member 24 A.
Securement member 24 B is more particularly designed for use with wire electrodes that do not greatly benefit from shielding material (i.e., gasless operation). As illustrated, the exemplary securement member 24 B has a interior channel 44 B region that matches closely the diameter of the diffuser 34 where the radial channels 36 are located. When the securement member 24 B is threaded onto the diffuser 34 , the internal surface 62 of the securement member 24 B blocks the egress of shielding material from the channels 36 . That is, the exemplary securement member 24 B does not present an interstitial space for the flow of shielding material, thus preventing the egress of this material. Moreover, the securement member 24 B protects the channels 36 from clogging weld splatter, for instance, when a gasless wire electrode is employed. Advantageously, the body 66 of the securement member 24 B is formed of an electrically insulative material, such as plastic, with low heat retention properties. Thus, the body 66 also serves as an electrical insulating member.
FIG. 5 illustrates the exemplary securement member 24 B of FIG. 4B in an exploded view. As illustrated, the exemplary securement member 24 B includes a body portion 66 that defines the external surface of the securement member 24 B as well as much of the channel 42 B. As discussed above, the exemplary body 66 is formed of an electrically insulative material, which, to allow easier user operation, may have low heat retention properties. The exemplary securement member 24 B also includes an insert member 70 that defines the internal shoulder 44 B. As illustrated, the insert member 70 is a hollow member that has an external surface with a plurality of ribs 72 extending axially thereon. These ribs 72 facilitate a good engagement of the insert member 70 with the body 66 when the insert member 70 is inserted into the body 66 . The ribs 72 may plastically deform the body 66 , thus well securing the insert member 70 with respect to the body 66 . The exemplary insert member 70 is formed of a durable material, such as metal, to provide for a more robust construction.
While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention. | A securement member for securing a contact tip to a welding torch assembly is provided. A channel extends axially therethrough and has an internal shoulder that extends into this channel. This internal shoulder abuts against a shoulder on the contact tip, capturing the contact tip between the shoulder and a seating surface on the diffuser and securing the contact tip in the torch assembly. The contact tip is securely seated without threading engagement, facilitating quick release and installation. The exemplary securement member couples to the diffuser such that the egress of fluid from the diffuser is blocked when used for gasless welding. This blocking allows a user to leave the diffuser secured to the welding torch when a gasless electrode is in use. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation of U.S. application Ser. No. 10/109,025, filed Mar. 28, 2002, now U.S. Pat. No. 7,882,103, issued Feb. 1, 2011.
BACKGROUND
[0002] Many business enterprises use data-warehousing systems to store detailed business data for use in making tactical and strategic business decisions. An enterprise-wide data warehouse typically stores a wide variety of information from all areas of the enterprise's business activities, such as customer accounts, items purchased by customers, product sales and inventories at individual retail stores, product distribution, employee-personnel records, and financial records. Such an enterprise-wide data-warehousing system gives decision-makers a single, detailed view of the entire business and allows them to base decisions on information representing the business as it really is, not simply as they suspect it to be.
[0003] Because data-warehousing systems often serve many areas of an enterprise's business, the demands for data freshness in the data warehouse often vary. The customer-service department, for example, might require customer-account data that is current to within a few minutes, or even seconds, for use in scoring a customer to influence that customer's interaction with the enterprise. Having an up-to-the-minute view of the customer's interaction with the business enterprise better enables the enterprise's data-analysis tools to produce accurate results, taking into account the most recent interactions with the customer.
[0004] The enterprise's finance department, on the other hand, might need data that is updated only once per week or once per month. Departments such as this typically do not require, and in fact are often hampered by, the extreme levels of data freshness needed in other areas of the business enterprise. A department that generates performance analyses covering week-long or month-long periods typically does not want the data for those periods to change while the analyses are under way.
[0005] Enterprises have traditionally met demands for varying levels of data freshness by maintaining duplicate copies of data in multiple databases or tables. Some of these databases, such as those that serve customer service departments, are updated very frequently, e.g., every few minutes or seconds. The databases that serve other departments, such as finance departments, are refreshed less frequently, e.g., once per day, once per week, or even once per month, quarter, or year.
SUMMARY
[0006] Described below is a data-warehousing system that allows various areas of an enterprise to view data at varying levels of data freshness. Such a data warehouse allows decision-makers in the business to see some information (e.g., customer transaction or account data) up-to-the-moment or as it stood at some specific point-in-time, such as at the end of the previous month. The data-warehousing system does this without requiring duplication of data, i.e., without requiring the replication of data in multiple databases or tables. The system allows the enterprise to maintain all of its data in a single database with refresh periods as short as the enterprise wishes. Departments that demand data that is refreshed less frequently can view the data as it stood at some point prior to the last refresh.
[0007] One technique described below involves storing data in such a database system. The system acquires data that represents an event in the life of a business enterprise, such as a transaction between the enterprise and one of its customers, and loads this data into a database table. The system then makes the data available for retrieval from the table and stores information indicating when the data was made available for retrieval. In some embodiments, the system also acquires data that is related to and more current than the data representing the event and stores the more current data in the database. The system then stores information indicating when the more current data was stored in the database.
[0008] Another technique involves allowing a user of a database system to view data representing events in the life of a business enterprise. The data is stored in at least one table that includes a first column of information indicating when the events occurred and a second column of information indicating when the data was made available for retrieval from the table. The system receives from the user a request for data representing events that occurred at or before a selected point-in-time and accesses the information stored in the two columns. The system uses this information to select from the table only that data for which the first column indicates that the corresponding event occurred at or before the selected point-in-time and the second column indicates that the data was made available for retrieval before the selected point-in-time. The system then presents the selected data to the user.
[0009] Another technique involves retrieving from a database system data that represents events in the life of a business enterprise, where at least some of the data has been updated by more current data. The system receives from a user information identifying a time period and events for which the user wants to view data. The system also constructs a database query that creates a table that stores data associated with that time period and those events. Using the information provided by the user, the system selects from the table the data that the user wants to view, where the selected data includes data for which more current data is available and excludes the more current data. The system then delivers the selected data to the user.
[0010] Other features and advantages will become apparent from the description and claims that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a schematic diagram of computer systems in various areas of a business enterprise that all share access to an enterprise data warehouse.
[0012] FIG. 2 is a schematic diagram of a massively parallel relational database management system (RDBMS).
[0013] FIG. 3 is a diagram of a database table that stores data representing events in the life of a business enterprise, including a date-time stamp for each table entry.
[0014] FIG. 4 is a diagram of a database table that stores event data, including an observation date-time stamp for each table entry.
[0015] FIG. 5 is a diagram showing a history table that is derived from other database tables.
[0016] FIG. 6 is a diagram of a database table that stores event data, including an observation-start date-time stamp and an observation-end date-time stamp for each table entry.
[0017] FIG. 7 is an example of a data-definition language (DDL) code segment for use in creating a “calendar table.”
DETAILED DESCRIPTION
[0018] FIG. 1 shows a computer network 100 in which an enterprise-wide data-warehousing system 110 supports the activities of the various departments in a business enterprise. The data-warehousing system 110 stores vast amounts of business-critical information, which agents of the enterprise use in making strategic and tactical business decisions. These agents access the information in the data-warehouse through one or more computer systems 120 , 130 , 140 scattered throughout the various departments of the enterprise. For example, employees in the enterprise's customer service, finance, marketing, and strategic planning departments might all require access to some portion of the data stored in the data warehouse 110 .
[0019] In many cases, the various departments of the enterprise have different requirements for the freshness of data stored in the data warehouse. For example, the customer-service department might require data that is updated in near-real-time (e.g., every few minutes or seconds) in dealing with customers for whom decisions must be made using up-to-date data. The finance department might require data that is updated only weekly or monthly and that remains consistent (i.e., does not change) during each weekly or monthly period. The data warehouse 105 shown here allows each of these departments to view data at the required level of freshness, and it does so without requiring duplication of data in multiple databases or tables.
[0020] FIG. 2 shows one example of a detailed architecture for the data-warehousing system 200 . In this example, the data warehouse 200 includes a relational database management system (RDBMS) built upon a massively parallel processing (MPP) platform. Other types of database systems, such as object-relational database management systems (ORDBMS) or those built on symmetric multi-processing (SMP) platforms, are also suited for use here.
[0021] As shown here, the data warehouse 200 includes one or more processing modules 205 1 . . . Y that manage the storage and retrieval of data in data-storage facilities 210 1 . . . Y . Each of the processing modules 205 1 . . . Y manages a portion of a database that is stored in a corresponding one of the data-storage facilities 210 1 . . . Y . Each of the data-storage facilities 210 1 . . . Y includes one or more disk drives.
[0022] The system stores transaction data and other business-critical data in one or more tables in the data-storage facilities 210 1 . . . Y . The rows 215 1 . . . Z of the tables are stored across multiple data-storage facilities 210 1 . . . Y to ensure that the system workload is distributed evenly across the processing modules 205 1 . . . Y . A parsing engine 220 organizes the storage of data and the distribution of table rows 215 1 . . . Z among the processing modules 205 1 . . . Y . The parsing engine 220 also coordinates the retrieval of data from the data-storage facilities 210 1 . . . Y in response to queries received from a user at a mainframe 230 or a client computer 235 . The data warehouse usually receives queries in a standard format, such as the Structured Query Language (SQL) put forth by the American National Standards Institute (ANSI).
[0023] FIG. 3 shows a database table 300 that might appear in a traditional data-warehousing system. Each column of the table 300 stores information about events that occur in the life of a business enterprise. For example, a company that manages an employee health-insurance plan might store information identifying each covered employee (EE_ID, column 310 ), the type of coverage selected by the employee (PLAN, column 320 ), and the number of covered dependents claimed by the employee (DEP, column 330 ). The table also includes a date-time stamp (EFF_DTS, column 340 ) showing when the employee's coverage began.
[0024] Data warehouses that consist of tables like this one are useful in analyzing and understanding business-critical data but are not as well equipped for supporting organizations that have varying requirements for data freshness. Because of the latency inherent in loading data into a data warehouse and, in many cases, delivering data to the enterprise, a database query that selects data according to a traditional effective-date stamp often produces a different result when submitted again at a later time. For example, an employee health plan that covers 200 employees on January 31 might cover an additional person as soon as that person begins work on February 1. Because of the inherent delay in delivering the employee's paper work from the employer to the insurer, the employee might not appear in the insurer's data warehouse until several weeks after the employee's start date. If the insurer were to create a report of covered employees as of February 1 on February 1 and again on February 28 using a traditional data warehouse, the reports would differ—the February 1 report showing 200 employees and the February 28 report showing 201 employees.
[0025] FIG. 4 shows a database table 400 that includes, in addition to the traditional column 410 showing the effective-date stamp, another column 420 that shows when the data was loaded into the data warehouse and was made available for viewing, or its observation date-time stamp (OB_DTS). The observation stamp allows the enterprise to see what data was available at any given time or during any given time period, and ensures that a query run at two different times will give the same result each time.
[0026] For the example given above, the record for the new employee includes the effective-date stamp showing when the employee's coverage began, as well as an observation stamp showing when the record was added to the database and made available for observation. Viewing data based upon on the observation stamp allows the insurer to generate, if so desired, identical reports on February 1 and again on February 28. The observation stamp allows the insurer to view, quickly and easily, the data that was available to it on February 1, even after the insurer has updated the data to reflect the employee's eligibility as of February 1.
[0027] In accessing transaction data—i.e., data which records transactional events that are routine in the life of the business, such as retail purchases by customers, call-detail records, bank deposits and withdrawals, and insurance claims—the data warehouse need only create views of the data it stores for each data-freshness service level, and it need only store the data once. These views filter the data according to the observation stamps that are stored with the data. Below is a selection of sample SQL code that creates a view of transaction data that was current as of 6:00 a.m. on February 20, 2001. In this example, “tx_dts” represents a transaction date-time stamp (i.e., a stamp indicating when a particular transaction took place), and “observation_dts” represents the observation stamp for the corresponding transaction data.
[0000]
create view edw.daily_tx
...
as locking table edw.tx for access
select tx.tx_id
,tx.tx_dts
,tx.observation_dts
,tx.tx_amt
...
from edw.tx
where tx.observation_dts <= ‘2001-02-20 06:00:00’
;
[0028] In accessing snapshot data—i.e., data that records the current or past state of the business or one of its relationships, such as customer status, the status of a customer's account, and the membership or address of a customer household—the data warehouse extracts all relevant data into a history table. As shown in FIG. 5 , the database-management system uses observation date-time stamps to select data from various tables 500 , 510 , 520 throughout the data warehouse and to place that data into a history table 530 . The history table 530 creates a point-in-time view of the business as it stood at the selected point-in-time.
[0029] One example of a history table for snapshot data is one that captures the average account balance of banking customers on a particular day, such as the first day of every month. Below is a selection of sample SQL code that creates such a table.
[0000]
create table account_history
(account_id decimal(12,0) NOT NULL
,observation_dt date FORMAT ‘YYYY-MM-DD’ NOT NULL
,account_balance_amt decimal(15,2) DEFAULT 0.0 NOT NULL
,account_status_cd char(1) DEFAULT ‘O’ NOT NULL
...
) primary index( account_id )
;
[0030] This technique is particularly useful for taking historical snapshots of data that an enterprise wishes to view with fixed periodicity. The account balance of a banking customer at the end of the customer's statement period is one example of the type of data that a business commonly wishes to view with fixed periodicity.
[0031] The typical business enterprise also often wishes to view snapshot data on an ad-hoc basis, with no regularity or periodicity in its viewing patterns. For example, businesses often view data when some event occurs that changes the view of that data, such as the acquisition of new data or the modification of old data, realignment or reorganization of the enterprise, and changes in a customer's status or life situation.
[0032] FIG. 6 shows such a table 600 . The first of the observation stamps, the “observation-start stamp” (OB_START_DTS) (column 610 ), indicates when the corresponding data has been loaded into the data warehouse and made available for viewing. The second of these stamps, the “observation-end stamp” (OB_END_DTS) (column 620 ), indicates when the row of data has become stale as a result of some event, such as an update to the database records or the expiration of a time period for which the data is accurate. For the most current observation of any particular row of data, the value of the observation-end stamp is set to “NULL,” or, alternatively, is set to a very distant future date. Below is a selection of sample SQL code for use in querying a history table to calculate the average income of customers as of the date Jan. 1, 2001.
[0000]
select avg(customer_history.income_amt)
from edw.customer_history
where customer_history.account_status_cd = ‘A’
and customer_history.observation_dt =
(select max(i_customer_history.observation_dt)
from edw.customer_history i_customer_history
where i_customer_history.observation_dt <= ‘2000-01-01’
and i_customer_history.customer_id =
customer_history.customer_id)
;
[0033] This example shows a code segment for use with a table that stores a single observation stamp. This code is relatively complex and is somewhat inefficient, because it includes a correlated sub-query to select all of the desired point-in-time data for the period of interest. Storing one or more additional observation date-time stamps, as described above, eliminates any need for a correlated sub-query and thus allows for more efficient queries with much simpler code. Below is a selection of sample SQL code for the same query as above, run against a table that stores two observation date-time stamps—an observation-start DTS and an observation-end DTS.
[0000]
select avg(customer_history.income_amt)
from edw.customer_history
where customer_history.account_status_cd = ‘A’
and customer_history.observation_start_dt <= ‘2000-01-01’
and (customer_history.observation_end_dt > ‘2000-01-01’
or
customer_history.observation_end_dt is NULL)
;
[0034] Storing observation date-time stamps in the tables of an enterprise data warehouse allows the enterprise to view data as of any point-in-time needed for decision-making purposes, and it does so without requiring duplication of data. Point-in-time views that an enterprise often needs are:
(1) “As is” view—Allows the enterprise to view the most current (“freshest”) data in the data-warehousing system. (2) “As-was” view—Allows the enterprise to view the data as it stood at a selected point-in-time before the most recent update. For the example given above, an “as-was” view allows the insurer to view a report on February 28 that shows only the 200 employees who, according to the insurer's data as it stood on February 1, were covered on February 1.
[0037] (3) “Mixed point-in-time” view—Allows the enterprise to combine data stored at different points-in-time according to query specifications. For the example given above, a “mixed point-in-time” view allows the insurer to see a list of the 200 employees who appeared in its records on February 1 listed according to their names as they appear in the most current data. This allows the insurer to see employee records as they stood on February 1 while taking into account any name changes that might have occurred since then.
[0038] FIG. 7 shows a sample code fragment that a database administrator might choose to run when setting up a database system. This code fragment creates a table, known here as a “calendar table,” that simplifies end-user access to point-in-time information in the database. Creating a calendar table and defining views to that table insulates the end-user from the database-query code needed to extract point-in-time information from the database.
[0039] Such a table is useful, for example, when the end-user wants to access information for a time period of selected length (i.e., one week or one month) on an ad-hoc basis. (e.g., with no particular regularity, beginning with a date or time chosen by the user). The user simply enters the point-in-time for which data is needed, and the database retrieves the appropriate data using the calendar table. The data pulled in response to the user's query remains consistent over time, so that the same query run at a later date produces the same result.
[0040] The user enters the point-in-time query through a simple user-interface program, such as a Windows-compatible graphical user-interface (GUI) program, running in the client system, the likes of which are well-known and are not described here. Below are sample database queries, shown in SQL code, for use in creating views to the data in the calendar table. The first query provides data for a period of one week; the second query provides data for a period of one month.
[0000]
create view edw.weekly_customer_history
( ... )
as locking table edw.customer_history for access
locking table edw.calendar for access
select customer_history.customer_id
,calendar.day_dt
...
,customer_history.birth_dt
,customer_history.income_amt
,customer_history.customer_status_cd
...
from edw.customer_history
,edw.calendar
where customer_history.observation_start_dt <=
calendar.fiscal_week_start_dt
and (customer_history.observation_end_dt >
calendar.fiscal_week_start_dt
or
customer_history.observation_end_dt is NULL)
;
create view edw.monthly_customer_history
( ... )
as locking table edw.customer_history for access
locking table edw.calendar for access
select customer_history.customer_id
,calendar.day_dt
...
,customer_history.birth_dt
,customer_history.income_amt
,customer_history.customer_status_cd
...
from edw.customer_history
,edw.calendar
where customer_history.observation_start_dt <=
calendar.fiscal_month_start_dt
and (customer_history.observation_end_dt >
calendar.fiscal_month_start_dt
or
customer_history.observation_end_dt is NULL)
;
Computer-Based and Other Implementations
[0041] The techniques described here are typically implemented in electronic hardware, computer software, or combinations of these technologies. Most implementations include one or more computer programs executed by one or more programmable computers in a data warehousing system. In general, each computer includes one or more processors, one or more data-storage components (e.g., volatile and nonvolatile memory modules and persistent optical and magnetic storage devices, such as hard and floppy disk drives, CD-ROM drives, and magnetic tape drives), one or more input devices (e.g., mice and keyboards), and one or more output devices (e.g., display consoles and printers).
[0042] The computer programs include executable code that is usually stored in a persistent storage medium and then copied into memory at run-time. The processor executes the code by retrieving program instructions from memory in a prescribed order. When executing the program code, the computer receives data from the input and/or storage devices, performs operations on the data, and then delivers the resulting data to the output and/or storage devices.
[0043] The text above describes one or more specific embodiments of a broader invention. The invention also is carried out in a variety of alternative embodiments and thus is not limited to those described here. For example, while much of the description above explains a health insurer's use of observation information in eligibility records, the techniques described here apply to other industries and business areas as well, including those in which transactions with customers are more prevalent, such the banking, retail and communications industries. Many other embodiments are also within the scope of the following claims. | A data-warehousing system allows various areas of an enterprise to view data at varying levels of data freshness. The system acquires data that represents an event in the life of a business enterprise, such as a transaction between the enterprise and one of its customers, and loads this data into a database table. The system then makes the data available for retrieval from the table and stores information indicating when the data was made available for retrieval. In some embodiments, the system also acquires data that is related to and more current than the data representing the event and stores the more current data in the database. The system then stores information indicating when the more current data was stored in the database. Such a data warehouse allows decision-makers in the business to see some information (e.g., customer transaction or account data) up-to-the-moment and other information as it stood at some specific point-in-time, such as at the end of the previous month. The data-warehousing system does this without requiring duplication of data, i.e., without requiring the replication of data in multiple databases or tables. The system allows the enterprise to maintain all of its data in a single database with refresh periods as short as the enterprise wishes. Departments that demand data that changes less frequently can view the data as it stood at some point prior to the last refresh. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus and a method for comminuting and dehydrating a variety of materials and, in particular, to an apparatus and method which produce comminuted and dehydrated materials by cyclonic pressure gradients through cochleated air-flow patterns.
2. Description of the Related Art
Numerous types of apparatuses and methods have been utilized to comminute materials having a variety of sizes, shapes, and physical characteristics, such as grains, ores, etc. Unfortunately, many of those apparatuses exhibited poor wearing characteristics and high maintenance problems, excessive noise generation, and high energy source requirements.
Similarly, numerous types of apparatuses and methods have been utilized to dehydrate various materials. Many of these apparatuses, in addition to many of the problems observed for the comminuters as aforesaid, exhibited heat generation and time consumption problems.
Various apparatuses have been developed in an attempt to utilize a destructive cyclonic environment for comminuting certain materials. For example, U.S. Pat. No. 4,390,131 discloses a method and apparatus for comminuting material, which utilizes three blowers: one for blowing air longitudinally into an inlet chamber and a frustoconical chamber, another for blowing air tangentially into a cylindrical chamber, and a third for assisting with discharging air entrained with the comminuted material. Unfortunately, all three blowers of this apparatus apparently must be simultaneously adjusted to select the desired throughput rate and coarseness of comminuted material.
What is needed is an apparatus and method which reliably and controllably harnesses the geostrophic relationship between air-flow velocity, pressure-gradient forces, and coriolis force, which are naturally present in the destructive, cyclonic environment of a tornado or cyclone, for practical purposes. Properly used, such destructive cyclonic forces can be harnessed for simultaneously comminuting or fractionating and dehydrating materials having a variety of sizes and physical characteristics and which utilizes the force of gravity such that a controlled cyclonic environment can be maintained by only one blower, thereby eliminating the complicated, interrelated adjustments normally required when using a plurality of blowers.
SUMMARY OF THE INVENTION
An improved comminuter/dehydrator apparatus and method are provided for comminuting and dehydrating a variety of materials having widely ranging sizes and physical characteristics.
The apparatus includes a cylindrically shaped chamber having a closed top, a closed side, an Open bottom, and a vertically oriented axis; a body spaced below and connected to the chamber having an inverted, conically shaped cavity with an open base upper end dimensioned substantially similar to the inside dimensions of the chamber, an open truncated lower end, a detachable nozzle adapted to provide greater truncation of the cavity such that the operable range of material sizes and types is extended, and a vertically oriented axis co-linear with the axis of the chamber and which subtends an angle which operably generates a centrally located low pressure region in conjunction with cochleated air flow patterns to thereby comminute and dehydrate materials pneumatically suspended therein; a cylindrically shaped sleeve extending through the chamber and into the cavity and having an open upper end, an open frustoconically shaped flange at its lower end, a vertically oriented axis aligned with the axis of the cavity, and a pair of diametrically opposed jacks adapted to adjust the spacing of the sleeve relative to the cavity; an inverted, conically shaped damper adaptably mounted such that it is adjustable toward and away from the sleeve open end and having a cooperating slot and gate mechanism situated near lower extremities thereof, and a tube with a deflecting elbow spaced therebeneath for off-axis depositing of certain materials being comminuted directly into the cavity; a blower adapted to generate high volume, high velocity air flow; a manifold adapted to duct the air flow from the blower to the chamber such that the air flow is directed substantially tangentially into the chamber; a venturi mechanism adapter to enhance the velocity of the air flow as it enters the chamber; and a material feeder valve having a hopper, an output port connected to the manifold in close proximity to the chamber, and an input port connected to the blower such that a portion of the air flow is directed through the valve.
The method includes the steps of providing an apparatus substantially as hereinbefore described; activating the blower to cause air to flow through the manifold substantially tangentially into the chamber such that the air in the chamber and in the cavity are cyclonically pressurized; introducing the material being comminuted and dehydrated into the apparatus; adjusting the spacing of the sleeve relative to the cavity and the spacing of the damper relative to the sleeve such that the desired rate of comminuting and dehydrating the material is selected and the desired coarseness of the comminuted material is selected by interaction between a centrally located low pressure region and cochleated air-flow patterns in the cavity; and gravitationally discharging the comminuted and dehydrated material from the apparatus.
Principal Objects and Advantages of the Invention
Therefore, the principal objects and advantages of the present invention include: to provide an apparatus and a method which simultaneously comminute and dehydrate a variety of materials; to provide such an apparatus which, except for a blower and a material feeder, has no operably moving parts; to provide such an apparatus and method which comminutes a variety of materials by the use of a single blower; to provide such a method and apparatus in which the comminuted material is discharged gravitationally; to provide such an apparatus and method which will accommodate materials having a variety of different sizes; to provide such an apparatus and method to accommodate a variety of different materials having different physical characteristics; to provide such an apparatus which is portable; and to generally provide such an apparatus which is efficient and reliable, relatively economical to manufacture, and which generally performs the requirements of its intended purposes.
Other principal objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by Way of illustration and example, certain embodiments of this invention.
The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary, side elevational view of a gradient-force comminuter/dehydrator apparatus, with portions cut away to reveal details thereof, according to the present invention.
FIG. 2 is a fragmentary view of the gradient-force comminuter/dehydrator apparatus, showing a damper thereof.
FIG. 3 is a fragmentary, top plan view of the damper of the gradient-force comminuter/dehydrator apparatus.
FIG. 4 is a fragmentary, top plan view of a material feeder valve connected to a blower and a manifold of the gradient-force comminuter/dehydrator apparatus.
FIG. 5 is a fragmentary, cross-sectional view of the gradient-force comminuter/dehydrator apparatus, taken generally along line 5--5 of FIG. 3.
FIG. 6 is a fragmentary, cross-sectional view of a venturi mechanism of the gradient-force comminuter/dehydrator apparatus, taken generally along line 6--6 of FIG. 1.
FIG. 7 is an enlarged and fragmentary, top plan view of a gate mechanism of the gradient-force comminuter/dehydrator apparatus with portions cut away to reveal details thereof, taken generally along line 7--7 of FIG. 5.
FIG. 8 is an enlarged and fragmentary, partially schematic, cross-sectional view of a nozzle of the gradient-force comminuter/dehydrator apparatus, according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.
The reference numeral 1 generally refers to a gradient-force comminuter/dehydrator apparatus for comminuting a variety of different materials having various sizes and various physical characteristics, in accordance with the present invention, as shown in FIGS. 1 through 8. The apparatus 1 comprises a cylindrical chamber 3, a body 5, pressurizing means such as a blower 7 and ducting means 9, air velocity enhancing means such as a venturi mechanism 11, material introducing means 13 for introducing material being comminuted into the apparatus 1, comminuting rate control means and coarseness control means for controlling the rate of comminution of the material being comminuted and the coarseness of the comminuted material such as a sleeve 15 in conjunction with a damper 17, and gravitational discharge means 19 for utilizing gravity to discharge the comminuted material from the apparatus 1.
The cylindrical chamber 3 has a closed, annularly shaped top 21 having a centrally spaced orifice 22, a closed side 23, an open bottom 25, and a generally vertically oriented axis AA, as shown in FIG. 1.
The body 5 has an inverted, conically shaped cavity 27 with base dimensions substantially similar to the inside dimensions of the chamber 3. Since the body 5 is inverted, the "base" refers to the topmost portion in FIGS. 1 and 5, i.e. the portion which mates with the chamber 3. The body 5 has a truncated lower end 29 and a generally vertically oriented axis which is substantially colinear with the axis of the chamber 3. The body 5 is connected to and suspended generally below the chamber 3. For some applications, the body 5 has a detachable nozzle 31, the removal of which provides greater truncation of the conically shaped body 5. Preferably, the conically shaped cavity 27 subtends an angle, as indicated by the arrow designated by the numeral 32 in FIG. 5, within the range of 28° to 42°. More preferably, the cavity 27 subtends an angle of approximately 36°.
The blower 7, such as a Model 602A Pressure Blower as provided by Garden City Fan & Blower Company, provides air at high volume and high velocity. The ducting means 9 include a manifold 33 for connecting the blower 7 to the chamber 3. In one application of the present invention, the manifold 33 had dimensions of 61/2-inches width and 9-inches height. For example, air flow of approximately 1000-8000 cfm may be used while maintaining a static pressure of approximately 3-50 inches.
The manifold 33 is connected to the chamber 3 such that air being forced therethrough into the chamber 3 is generally directed substantially tangentially into the chamber 3. To maintain consistency with natural forces, the air is introduced into the chamber 3 such that the air spirals in a clockwise direction as viewed downwardly.
The venturi mechanism 11 generally includes a pair of opposing, arcuately shaped sidewall plates 34 spaced within the manifold 33 such that a throat 35 is formed therebetween. In one application of the present invention, the throat 35 had a width of approximately 31/2 inches. The venturi mechanism 11 is generally spaced in close proximity to the chamber 3.
The material introducing means 13 may include a valve 37, such as a Model VJ8x6 Airlock Valve as provided by Kice Industries, Inc. An input port 39 of the valve 37 is connected to the blower 7 by an upstream pipe 41 such that a portion of the pressurized air being transferred from the blower 7 to the chamber 3 is routed through the valve 37. An output port 43 of the valve 37 is connected to the manifold 33 by a downstream pipe 45 such that material being comminuted and dehydrated by the apparatus 1 is generally directed into the manifold 33 either at, or downstream from, the venturi mechanism 11. A hopper 47 is mounted on the valve 37 such that material being comminuted is gravitationally fed into the valve 37.
The sleeve 15 is generally cylindrically shaped and has an outside diameter dimensioned slightly smaller than the dimensions of the orifice 22. The sleeve 15 extends axially through the chamber 3 and extends into the cavity 27 spaced therebelow. The sleeve 15 includes a truncated, conically shaped flange 49 which has an open lower end 51.
Elevating means, such as a pair of jacks 53 spaced diametrically across the sleeve 15 and generally above the chamber 3, are adapted to cooperatively, axially adjust the sleeve 15 relative to the chamber 3 and the cavity 27.
The damper 17 is adapted to selectively restrict air flowing through the sleeve 15 from the cavity 27 into the ambient atmosphere, as indicated by the arrows designated by the numeral 54 in FIG. 1. The damper 17 is generally threadably mounted on a Vertically oriented threaded rod 55 connected to a bracket 57 which is connected to the sleeve 15, as shown in FIGS. 1 and 2, such that the damper 17 is adjustable toward and away from the sleeve 15. Preferably, the damper 17 is configured as an inverted cone. In one application of the present invention, the conically shaped damper 17 encompasses an angle of approximately 70°.
The damper 17 generally has slots 59 near the lower extremity thereof. A gate mechanism 61 is adapted to selectively open and close the slots 59 such that selected material being comminuted can pass therethrough. A discharge tube 63 is detachably connected to the damper 17 such that material falling through the slots 59 is gravitationally introduced directly into the cavity 27 as hereinafter described.
In one application of the present invention, the apparatus 1 includes turbulence-enhancing means comprising a plurality of ribs 65. Each of the ribs 65 is generally elongate, with a length approximately equal to the axial length of the chamber 3 and has a roughened surface. The ribs 65 are parallelly spaced apart along the inner perimeter of the chamber 3. Frame means 67 are provided as needed to maintain the various portions of the apparatus 1 in their relative positions and for mounting on a trailer (not shown) for portability, if desired.
In an application of the present invention, the blower 7 is activated such that high volume, high velocity air is introduced substantially tangentially into the chamber 3 whereby that air is further pressurized, cyclonically, in the chamber 3 and in the cavity 27. Due to the centrifugal forces present in the cyclonic environment, the pressure nearer the outer extremities of the cavity 27 is substantially greater than atmospheric pressure, while the pressure nearer the axis of the cavity 27 is less than atmospheric pressure.
A profile line, designated by the dashed line designated by the numeral 69 in FIG. 5, indicates the approximate boundary between the region of the cavity 27 having pressures above atmospheric pressure from the region of the cavity 27 having pressures below atmospheric pressure. The pressure-gradient and coriolis forces across and the collision interaction between particles contained in the high-velocity cyclonically pressurized air are violently disruptive to the physical structure of those particles, thereby comminuting and generally dehydrating them.
As the sleeve 15 is lowered by adjusting the jacks 53, as indicated by the phantom lines designated by the numeral 70 in FIG. 1, the profile line 69 moves radially outwardly, providing greater cyclonic velocities and force gradients. Thus, vertical adjustment of the sleeve 15 allows the apparatus 1 to be adapted to accommodate materials having widely different physical characteristics.
The lower the sleeve 15 is spaced relative to the cavity 27, the smaller the combined total volume of the chamber 3 and the body 5 which is available for air circulation. Since the volume of air being introduced remains constant, this reduction in volume causes a faster flow of air, causing a greater cyclonic effect throughout the body 5 and consequently causing the material being comminuted to circulate longer in the chamber 3 and the body 5. The increased cyclonic flow also increases the vacuum effect which generates the suction near the vortex of the open lower end 29, as indicated by the arrow 71 in FIG. 8, causing generally vertical, cochleating and resonating, oscillatory patterns in the air flow containing the material being comminuted to be more violent and thereby affecting the coarseness of the comminuted material. For some applications and configurations of the apparatus 1, the air flow indicated by the numeral 71 may only be nominal.
Similarly, adjusting the damper 17 relative to the sleeve 15, which controls the volume of air allowed to escape from the center, low-pressure region of the cavity 27 into the ambient atmosphere, affects the cyclonic velocities, force gradients, and vertical oscillations as the apparatus 1 is adjusted to handle various throughput volumes of materials being comminuted.
The throughput rate for comminuting the material is controlled by adjusting the rate and manner in which material is being fed into the apparatus 1. If the material is to be both comminuted and dehydrated, then the material is generally fed into the apparatus 1 by the valve 37. In that event, the gate mechanism 61 may be used as a fine control for the coarser adjustments of the damper 17 relative to the sleeve 15.
If the material is relatively fine, such as wheat and the like, and is to be largely comminuted and only minimally dehydrated, then the material may be fed into the apparatus 1 by the damper 17 and the gate mechanism 61 in cooperation with the slots 59. In that event, the material being comminuted falls through the slots 59 and drops gravitationally downwardly through the discharge tube 63 where an elbow 73 injects the material directly into the high cyclonic pressure region of the cavity 27.
As the material is comminuted, the finer particles thereof tend to diffuse to the conical perimeter of the cavity 27, as indicated by the numeral 75 in FIG. 8. As those finer particles accumulate, they tend to move gravitationally downwardly to the open lower end 29 where the particles exit from the apparatus 1, assisted by the annularly shaped air leakage from the cyclonically higher pressure region along the perimeter of the cavity 27, as indicated by the arrows designated by the numeral 77 in FIG. 8. By continually feeding material into the apparatus 1, a continuous throughput of comminuted material is provided.
By selectively utilizing the apparatus with and without the nozzle 31, a greater range of sizes and types of materials, and greater throughput rates are obtainable with the apparatus 1
A container, conveyor belt or other suitable arrangement (not shown) spaced below the lower end 29 receives the comminuted material as it is gravitationally discharged from the apparatus 1.
It is to be understood that while certain forms of the present invention have been illustrated and described herein, it is not to be limited to the specific forms or arrangement of parts described and shown. | An improved comminuter/dehydrator apparatus and method includes a body having an inverted, coaxially shaped cavity with an open truncated lower end and an open upper end connected to a cylindrically shaped chamber. A sleeve, which extends through the chamber and into the cavity, is adjustable axially by a pair of jacks. A damper is adjustable relative to the sleeve to control air escaping from the cavity into the ambient atmosphere. A manifold with a velocity-enhancing venturi mechanism directs air from a blower tangentially into the chamber to create cochleated and resonating, oscillatory cyclonic air-flow activity. A portion of the air from the blower to the chamber is diverted through a feeder containing the material being comminuted and dehydrated. The comminuted and dehydrated material is gravitationally discharged through the cavity lower end. The body has a removable nozzle tip to extend the operational characteristics of the apparatus. Finer materials being comminuted may be gravitationally directed into the cavity through a tube and elbow arrangement spaced below a slot and gate arrangement in the damper. | 5 |
BACKGROUND
Various embodiments of the invention relate generally to a device using first-in-first-out (FIFOs) and particularly to configurable FIFOs.
FIFOs are common place in a variety of applications, sensors are no exception to such applications. Sensors, among other applications, often require multiple FIFOs, which increases the design area and increases power consumption. Additionally, other types of memory, such as static random access memory (SRAM) when used in conjunction with FIFOs, increases valuable memory real estate.
In sensor applications, conventional FIFOs are generally fixed in size thereby limiting their flexibility and wasting valuable memory space. For example, FIFOs used in a sensor application each correspond to a particular sensor and a fixed FIFO size fails to allow for the size of the FIFO to change and correspond to the requirements of an associated sensor.
There is thus a need for a configurable FIFO and a method and apparatus for using the same.
SUMMARY
Briefly, a device includes one or more sensors, one or more processors coupled to the one or more sensors, and a memory coupled to the one or more sensors and the one or more processors. The memory has a first portion, a second portion, and a third portion, the third portion being a first-in-first-out (FIFO) having one or more FIFO portions. The first portion of memory is allocated to store instructions for execution by a processor of the one or more processors. The second portion is allocated to store data generated by the processor, and the third portion is allocated to store data from the one or more sensors. The device further includes a control logic coupled to the memory and operable to allocate the first, second and third portions of the memory, wherein each of one or more FIFO portions of the third portion of memory is allocated to each of the one or more sensors.
A further understanding of the nature and the advantages of particular embodiments disclosed herein may be realized by reference of the remaining portions of the specification and the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a system 100 to include an application processor, a device, motion processing unit (MPU), and external sensors, in accordance with an embodiment of the invention.
FIG. 2 shows exemplary contents of the memory of FIG. 1 .
FIG. 3 shows a memory 300 including an exemplary FIFO or FIFO portion, in accordance with an embodiment of the invention.
FIG. 4 shows a memory 400 including multiple FIFOs, in accordance with another embodiment of the invention.
DETAILED DESCRIPTION OF EMBODIMENTS
The following describes a device using multiple configurable FIFOs. The multiple configurable FIFOs may be a single FIFO with multiple portions with each portion re-sized to fit the application in which the FIFOs are employed or multiple configurable FIFOs with each FIFO re-sized to fit the application in which the FIFOs are employed. Further, each FIFO or FIFO portion is configured to be accessed by multiple consumers, as discussed below. In the described embodiments, “consumers” refer to users of FIFOs, namely devices that read the contents (also referred to as “data”) of a FIFO and “producers” refer to devices or users that write data to or program the FIFO.
Referring now to FIG. 1 , a system 100 is shown to include an application processor 104 , a motion processing unit (MPU) 102 , and external sensors 120 , in accordance with an embodiment of the invention. The MPU 102 is shown coupled to the external sensors 120 through a bus and is further shown to send “data” to the application processor 104 and to receive information from the application processor 104 .
The MPU 102 is shown to include registers 106 , control logic 108 , direct memory access (DMA) 110 , memory 112 , internal sensors 116 , embedded processor 114 , and a bus master 118 . The MPU 102 is shown coupled to the bus 122 and the external sensors 120 through the bus master 118 .
The components of the MPU 102 can include MEMS sensors and electronic circuit. In an embodiment, the sensors can include MEMS accelerometers, gyroscope, magnetometer and pressure sensors. Some embodiments include an accelerometer, a gyroscope, and a magnetometer, each providing a measurement along three axis orthogonal to each other. Other embodiments may not include all the sensors or may provide measurements along one or more axis. The sensors are formed on a first substrate.
In an embodiment, the electronic circuit receives the measurement outputs, stores the raw data, and processes the raw data to generate motion data, apart from other operations. The operations are performed by register 106 , control logic 108 , DMA 110 , memory 112 , embedded processor 114 , and bus master 118 . The electronic circuit is implemented on a second silicon substrate. The first substrate is vertically bonded to the second substrate. In the described embodiments, “raw data” refers to the measurement outputs of the sensors and “motion data” refers to the processed raw data.
In an embodiment, the electronic circuit receives the measurement outputs, store the raw data process the raw data to generate motion data apart from other operations. The operations are performed by register 106 , control logic 108 , DMA 110 , memory 112 , embedded processor 114 , bus master 118 . The electronic circuit is implemented on a second silicon substrate. The first substrate is vertically bonded to the second substrate. In the described embodiments, raw data refers to the measurement outputs of the sensors and motion data refers to the processed raw data.
In one embodiment, MPU 102 is implemented by vertically stacking and bonding the MEMS sensors on the first substrate to the electronic circuit on the second substrate using wafer-scale bonding processes as described in commonly owned U.S. Pat. No. 7,104,129 (incorporated by reference above) that simultaneously provides electrical connections and hermetically seals the MEMS devices. This unique and novel fabrication technique is the key enabling technology that allows for the design and manufacture of high performance, multi-axis, inertial sensors in a very small and economical package. Integration at the wafer-level minimizes parasitic capacitances, allowing for improved signal-to-noise relative to a discrete solution. Such integration at the wafer-level also enables the incorporation of a rich feature set which minimizes the need for external amplification.
The DMA 110 sends data to the application processor 104 and receives data from the memory 112 . The registers 106 receive information from the application processor 104 and in turn, provide information to the control logic 108 , which are shown coupled to the memory 112 . Further coupled to the memory 112 is shown the embedded processor 114 . Embedded processor 114 transmits data to the memory 112 and receives instructions or data from the memory 112 . Bus master 118 sends raw data received from the external sensors 120 to memory 112 . The internal sensors 116 provide raw data to the memory 112 . Accordingly, raw data from the internal sensors 116 and the external sensors 120 is transferred to and saved in the memory 112 . “Internal sensors”, as used herein, refers to sensors that are formed on the same semiconductor or integrated circuit (IC) chip as the rest of the components of MPU 102 . “External sensors”, as used herein, refers to the sensors that are located externally to the MPU 102 . In the described embodiments, internal sensors can be MEMS devices, solid state sensors or any other type of sensors. Example of sensors are accelerometer, gyroscopes, pressure sensors, magnetometer, and microphone.
In sensor applications, information transferred from the embedded processor 114 to the memory 112 is motion data. As will be further evident shortly, the instruction program as well as the embedded processor data are saved in the memory 112 .
The application processor 104 resides externally to the MPU 102 and is generally a separate processor dedicated to an application employing the MPU 102 and the external sensors. Data is transferred to and from the application processor 104 , by the MPU 102 , through the DMA 110 . In an embodiment, registers 106 store sensor and memory configuration information. Exemplary information, without limitation, that is stored in the registers 106 is static override size of the FIFOs, the minimum size of data and instruction memory, the output data rates of sensors, and the size of data packets of each sensor, such as the sensors 116 and 120 of the embodiment of FIG. 1 .
The control logic 108 controls the manner in which memory is allocated for the various sensors employed, such as the sensors 120 and 116 , and the embedded processor 114 . The control logic 108 further controls the pointers to the FIFOs. The FIFOs are a part of the memory 112 . In addition to pointer management as a part of its function, the control logic 108 allocates the minimum size of the data and instruction memory for the embedded processor 114 , flexibly sizes the FIFO portion, dynamically reallocates memory (or FIFOs) when the FIFO portion is modified, determines the number of portions in which to divide the FIFO portion and the size of each FIFO portion. It is noted that “FIFO portion” and “FIFO” or “FIFO portions” and “FIFOs” are used synonymously herein.
During operation, raw data is received by the memory 112 from the sensors 116 and 120 and stored in a dedicated FIFO or FIFO portion for processing by the embedded processor 114 and ultimately used by the application processor 104 .
FIG. 2 shows exemplary contents of the memory 112 of FIG. 1 . The memory 112 is shown as the memory 200 in FIG. 2 and includes an embedded processor program random access memory (RAM) 202 , an embedded processor data RAM 204 , and five FIFOs—FIFOs 206 to 214 . In other embodiments, memory 200 can have any number of FIFOs. The program RAM 202 and the data RAM 204 are generally for use by the embedded processor 114 in that a program, saved in the RAM 202 , is executed by the embedded processor 114 and in the process of execution, data from the data RAM 204 is utilized by the embedded processor 114 .
As shown in the embodiment of FIG. 2 , each of the FIFOs 206 - 214 has a distinct size. The FIFOs 206 - 214 are also referred to herein as “FIFO portions” because they may alternatively be a part of a single FIFO. The RAMs 202 and 204 are advantageously formed on the same semiconductor (or IC) as the multiple FIFOs.
In some embodiments, the size of each of the FIFOs 206 - 214 is the same. In some of the embodiments the size of some of the FIFOs 206 - 214 is the same. In some embodiments, the size of each of the FIFOs 206 - 214 is unique.
The memory 200 has a start address pointer and an end address pointer, both of which are controlled by the control logic 108 . Further, as will be shown in greater detail shortly, each of the FIFOs 206 - 214 has pointers controlled by the control logic 108 .
In summary, the memory 200 shows an example of the memory partitioned into five FIFOs, i.e. FIFO 206 - 214 , and instruction program, i.e. program RAM 202 , and DATA RAM 204 for use for the embedded processor 114 . Distinct sizing is shown for each FIFO, in FIG. 2 , and advantageously the entire memory structure is utilized. This is accomplished due to the configurable FIFOs 206 - 214 . That is, the number of FIFOs is dynamically allocated based on the number of sensors enabled. By way of example, if a sensor is disabled, the FIFO space for that sensor is freed up and allocated to the data portion of the memory for the embedded processor 114 . Disabling a sensor refers to the sensor being either turned off or in a low power state where the sensor does not transmit any data. Enabling a sensor refers to the sensor being on or in a non-lower power state where the sensor is able to transmit data.
The control logic 108 of the embodiment of FIG. 1 sizes each of the FIFOs of the embodiments of FIGS. 3 and 4 in accordance with the following steps. During initial power-on of the device 102 , the control logic 108 allocates the minimum memory size for the program RAM 202 and data RAM 204 . The minimum size of the required memory for program RAM 202 and data RAM 204 is specified in the registers 106 . The control logic 108 , next, allocates memory for FIFOs, such as the memory shown to be reserved for the FIFOs 206 - 214 in FIG. 2 . In the case where the FIFOs are employed in a device using sensors, the number of FIFOs assigned is generally equal to the number of enabled sensors. Each sensor advantageously has a dedicated FIFO in memory. The size of each FIFO is calculated by the control logic 108 based on the data rates or bandwidth of corresponding sensors. Typically, the higher the data rate of a sensor, the larger the size of the FIFO size being allocated to that sensor. In some embodiments, the raw data is made of packets and the size of each of the FIFOs or FIFO portions is a multiple of the size of a data packet. In such embodiments, the granularity of the FIFO size is the minimum packet size of the sensor i.e. the FIFO size is an integer multiple of the packet size of the sensor.
In some embodiments, the control logic 108 allows for an entire packet to be written into a FIFO only if there is enough space in the FIFO for an entire packet. This advantageously substantially guarantees that data packets are stored in their entirety in the FIFO and also the locations of the data packets in the FIFO are at fixed offsets in the FIFO relative to each other, which makes for easier access of the data packets in the FIFO from the embedded processor and application processor.
Start and end addresses for each of the FIFOs are maintained by the control logic 108 . The start and end address of each of the FIFOs effectively determines the size of the FIFO.
The memory or area of FIFO or FIFO portion that is not allocated to the minimum size of RAM 202 or minimum size of data RAM and/or to the FIFO is allocated to the RAM 204 for the embedded processor data 114 .
In some embodiments, the sizes calculated by the control logic 108 can be overridden by sizes explicitly defined in the registers 106 . That is, initially, sizes of FIFOs are predetermined and saved in the registers 106 and subsequently, these sizes may be adjusted or re-configured by the control logic 108 to better fit the requirements of the particular application.
Among other attributes, the memory 200 has a smaller design area than that of prior art memories due to the use of multiple FIFOs or multiple FIFO portions because a single SRAM is used for multiple FIFOs instead of use of a SRAM for each FIFO, which clearly results in a larger area. Smaller area advantageously results in reduced power consumption. Moreover, use of the SRAM size is optimized. Additionally, each FIFO can be sized proportionally to the data rate being written to the FIFO. For example, the rate of a sensor defines, at least in part, the size of the FIFO, which is configurable.
FIG. 3 shows a memory 300 including an exemplary FIFO or FIFO portion, in accordance with an embodiment of the invention. The FIFO 300 may be any one of the FIFOs 206 - 214 of the embodiment of FIG. 2 and stores data 302 . The FIFO 300 is shown to have three pointers, read pointer 1, read pointer 2, and a single write pointer. While two read pointers are shown in FIG. 3 , any number of read pointers may be employed.
The FIFO (or FIFO portion) 300 is a single FIFO having one write pointer and two read pointers. This structure allows for data to be written by one client (or “producer”) and read by two independent clients (or “consumers”), such as the embedded processor 114 and the application processor 104 . Data between the read and write pointers is valid FIFO data. New data is written to the FIFO at the location pointed to by a corresponding write pointer and the write pointer advances, increments by the number of entries in the data packet, as long as the write pointer does not cross the read pointer. The FIFO 300 is a circular type of FIFO.
Regarding pointer management of the FIFO 300 , the following is noted. As discussed above, the FIFO 300 can have multiple read pointers from multiple independent FIFO data consumers but only has a single write pointer from a single FIFO data producer. Data to the FIFO 300 is written to a location identified by the FIFO address that is stored in the registers 106 or the control logic 108 , as the write pointer. Data from the FIFO 300 to a consumer is read from a FIFO address that is stored in the consumer's read pointer, in the registers 106 or the control logic 108 . The read pointer to the FIFO 300 , i.e. data consumer, advances (or increments) by a single address for each data read by that consumer. Advancing of the FIFO read and write pointers is generally performed by the control logic 108 . The write pointer from the FIFO data producer advances by a single address for each data write by the producer.
Each FIFO data consumer has an empty and a full status. Empty status of a consumer is set when a FIFO is reset or when the read pointer to the consumer advances and its value equals the value of the write pointer. Full status of a consumer is set when the write pointer advances and its value equals the value of the read pointer to the consumer. Additionally, multiple data consumers can access the same FIFO or FIFO portion.
The FIFO data consumers can be configured to be blocking or non-blocking. In cases where a FIFO (such as the FIFO 300 ) data consumer is configured to be blocking, the FIFO's corresponding read pointer blocks the write pointer to the FIFO i.e. the write pointer cannot advance beyond where the read point points to. The FIFO is said to be full at this point and any additional writes when the FIFO is full are dropped.
When a FIFO (such as the FIFO 300 ) data consumer is configured to be non-blocking, its read pointer does not block the write pointer. In cases where the FIFO is full and the write pointer matches the read pointer of a non-blocking consumer and there is an additional write to the FIFO, both write and read pointers of the FIFO advance and the additional data is written to the FIFO.
FIG. 4 shows a memory 400 including multiple FIFOs, in accordance with another embodiment of the invention. The memory 400 is the same as the memory 300 after the FIFO 1 212 has been decreased in size and the FIFO 3 208 has been removed in its entirety. The freed space 407 due to removal of FIFO 1 and 409 due to decrease in size of FIFO 1 is allocated for Embedded Processor data RAM 404 , thus making full use of the SRAM. The read and write pointers for the resized FIFO 1 are reset. The read and write pointers of the FIFO 0, FIFO 2, and FIFO 4 are unaffected by this operation
In the case where a FIFO is increased in size or a new FIFO is added as yet another FIFO or FIFO portion, the start and end addresses for all the FIFOs are recalculated but data integrity for an FIFO is not guaranteed as the start address of all the FIFOs in the memory 400 or 300 or 112 might change from that which it was previously.
Although the description has been described with respect to particular embodiments thereof, these particular embodiments are merely illustrative, and not restrictive.
As used in the description herein and throughout the claims that follow, “a”, “an”, and “the” includes plural references unless the context clearly dictates otherwise. Also, as used in the description herein and throughout the claims that follow, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
Thus, while particular embodiments have been described herein, latitudes of modification, various changes, and substitutions are intended in the foregoing disclosures, and it will be appreciated that in some instances some features of particular embodiments will be employed without a corresponding use of other features without departing from the scope and spirit as set forth. Therefore, many modifications may be made to adapt a particular situation or material to the essential scope and spirit. | A device includes one or more sensors, one or more processors, one or more sensors, and a memory. The memory has a first portion, a second portion, and a third portion. The first portion is allocated to storing instructions for execution by the one or more processors. The second portion is allocated to storing data generated by the one or more processor, and the third portion is allocated to storing data from the one or more sensors. The third portion being a first-in-first-out (FIFO) having one or more FIFO portions, The device further includes a control logic operable to allocate the first, second and third portions of the memory, wherein each of one or more FIFO portions is allocated to each of the one or more sensors. The size each of the FIFO portions depends on the bandwidth of the sensors and the number of sensors. | 6 |
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