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BACKGROUND OF THE INVENTION
1. The Field of the Invention
This invention relates to means for distributing steam on a moving sheet of paper.
2. State of the Art
In most paper products it is desirable to automatically control the cross machine moisture content using a steam shower or steam distributor. Most paper machines have continuous moisture scanners which read the sheet moisture content across the machine as the paper is manufactured. The information from this continuous measurement can be fed into a controlling computer and the steam flow in the steam distributor can be automatically controlled according to this information.
One type of steam distributor is taught in U.S. Pat. No. 4,253,247. The patent teaches a multi-chambered steam hood with means of steam distribution to each chamber provided by a steam distributor. Steam flows from the steam distributor through ports into a nozzle and into each chamber. The steam flow is controlled by raising or lowering a control plug.
A vacuum box is located on the side of the paper opposite the steam hood so that a vacuum can be applied to pull steam through the paper. The vacuum is normally applied only when steam is introduced into the steam distributor. If, however, due to mechanical failure or operator error the steam flow is stopped while vacuum continues to be applied, sufficient sunction could be produced to pull the distributor onto the moving web of paper. This could result in damage to the paper and to the Fourdrinier wire.
OBJECT OF THE INVENTION
An object of the present invention is to provide a steam distribution system with vacuum release means to prevent the distributor from being pulled onto the paper web by vacuum.
Further objects and advantages of the invention can be ascertained by reference to the specification and drawings which are provided by way of example and not in limitation of the invention, which is defined by the claims and equivalents.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a paper making machine including a steam distributor;
FIG. 2 is an isometric illustration of a present embodiment;
FIG. 3 is a cross sectional illustration of a present embodiment;
FIG. 4 is a detail of part of the embodiment shown in FIG. 3; and
FIG. 5 is a cross sectional illustration of another embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
There is shown in FIG. 1 a paper making machine 10 including a hot gas distributor 12. In practice steam is normally used; however in some applications other hot gases could be substituted. Herein the word steam will be used to mean steam or such other hot gas. The machine shown is of the Fourdrinier type and includes a pulp box 14 feeding pulp mixture 16 to a web-like conveyor 18 on which the liquid is drawn from the pulp to leave a paper web 20, which travels partially dried under the distributor 20 and over vacuum box 22, a press section 26, further dryers (not shown) and a known moisture measuring device (not shown) which measures the moisture content across the sheet. The distributor is adjusted manually or automatically to reduce the moisture variations in the cross direction.
As shown in FIG. 2 the steam distributor 12 includes a hood 38 having end plates 30 at each end, each supported by a pair of legs 32 carried by feet 34 mounted on the conveyor frame (not shown) outside the path of the conveyor. A pipe 36 is supported by the end plates 30. A steam pipe 40 supplies a hot gas, in the present instance, steam from a suitable source to the pipe 36. The hood 38 includes outer shell 42, an inner shell 44 and insulation 46 which together form side walls 47 and 49. Transverse partitions 48 divide the hood into a plurality of chambers or compartments 50 spanning the entire width of the web 20. Tubes 52, individual to the compartments having ports 51 each supplies steam to its compartment in accordance with the setting of a pneumatic valve 56 individual to that chamber and controlled by the moisture profile measuring device or manually. The steam travels through the pipe 36, through ports 51 into the tubular nozzles 52, through the nozzles into the chambers 50, through slotted, arcuate diffusing plates 60, through the web 20 and a supporting screen or vacuum box cover 62 forming the top of a vacuum box 22. The diffusion plates may be drilled plates of different patterns. The plates may be omitted to leave an open bottom chamber.
Details of the valves 56 are not taught herein and can be ascertained from U.S. Pat. No. 4,253,247, discussed above. Other known types of valves are also suitable.
Turning to FIG. 3, there is shown an embodiment of the invention including vacuum release means formed in the sidewalls 47 and 49. The sidewalls 47 and 49 of the chamber 50 are spaced apart from paper web 20 so that spaces 70 and 72 are formed therebetween. In practice, we have found it desirable to space the sidewalls 47 and 49 about four inches above the paper web 20. Hinges 74 and 76 are mounted along the bottoms of side walls 47 and 49 and plates 78 and 80 are affixed one to each hinge. The plates are of sufficient height to extend from the hinges to about three quarter inch above the paper web 20.
FIG. 4 shows further details of the hinge 76, which is substantially the same as hinge 74. The hinge 76 includes a plurality of cylinders 82 welded to the plate 80 and a plurality of similar cylinders 84 welded to the sidewall 49. The cylinders 82 are spaced apart from one another and the cylinders 84 are located between them. Also, the cylinders 82 and 84 are slightly spaced apart from one another. A rod 86 is inserted through the cylinders 82 and 84 to form the pivot member.
In operation, steam is introduced into the hood 38 and vacuum is applied to the vacuum box 22 so that the pressure in the hood is near ambient. In this case the plates 78 and 80 are vertical as indicated by plate 78 in FIG. 3 so that no substantial quantity of steam escapes to the atmosphere and no substantial quantities of ambient air enters the hood. However, if through operator error or mechanical failure steam is not introduced through pipe 36 while vacuum is applied to the box 64, ambient air is drawn into the hood as indicated by the arrows, and the plate is opened by the air flow as shown by plate 80. Thus the vacuum does not exert downward force on the hood 38. It should be understood that the downward force on the hood 38 could be extreme, if not for the present invention. For example, for a hood 60 inches in width and 300 inches in length 90,000 pounds of force would be exerted by a vacuum of five pounds per square inch, which is not uncommon.
In some applications it could be necessary to have only one plate 78 or 80 rather than both plates. In such a case sidewall 47 or 49 would extend downward to near the paper mat 20. However, in practice I have found it generally desirable to utilize two plates which will move slightly to accommodate high spots in the paper mat thus insuring that the mat will not build up against a sidewall.
FIG. 5 illustrates another embodiment in which plates 82 and 84 are similar to plates 78 and 80. However, plates 82 and 84 have upper portions 86 and 88 which extend above the hinges 74 and 76. The upper portions 86 and 88 are constructed to conform to the lower parts of sidewalls 47 and 49 and to prevent the lower parts of the plates from swinging outwardly. Thus the plates 82 and 84 prevent the escape of substantial quantities of steam even if the steam pressure becomes high in the hood.
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The specification discloses a steam distributor having a chamber to contain steam on one side of a paper web and a vacuum box on the opposite side of the paper web. The chamber has a vacuum release means to prevent the chamber from being pulled onto the paper web if vacuum is applied when steam is not applied.
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BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor memory and, more particularly, to a technique which may effectively be applied to, for example, a micro-programmable ROM (Read-Only Memory) which may be incorporated in a digital processing device that adopts the microprogram system.
Digital processing devices that adopt the micro-program system are described, for example, in "Micro-programming and Its Application", Sangyo Shuppan Kabushiki Kaisha, May 20, 1974, pp. 48 to 51.
SUMMARY OF THE INVENTION
FIG. 4 shows a read circuit in a micro-programmable ROM which has been developed by the inventors of this application prior to the present invention, and FIG. 5 is a timing chart showing the read operation of the circuit shown in FIG. 4. Referring to these figures, memory cells Q11, Q16 . . . of a ROM which are respectively constituted by N-channel MOSFETs are connected to a common data line CD1 through a data line D1 by the operation of the switching MOSFET (also serving as a capacitance cut-off MOSFET) Q5 which is supplied with a signal Y1. A relatively small parasitic capacitance Cc and a relatively large parasitic capacitance Cd are equivalently coupled to the common data line CD1 and the data line D1, respectively. These parasitic capacitances are precharged with a power supply voltage Vcc through a precharge MOSFET Q1 which is supplied with a signal φ1 formed by inverting a timing signal φ1. The potential of the common data line CD1 after precharge is at a high level which is substantially equal to the power supply voltage Vcc, whereas the potential of the data line D1 is at a level which is substantially equal to Vcc-Vth, that is, the potential is lower than the power supply voltage Vcc by an amount which is substantially equal to the threshold voltage Vth of the switching MOSFET Q5.
The precharge levels of the common data line CD1 and the data line D1 are discharged by the fact that the corresponding memory cells in the ROM are turned ON in response to a word line select signal W1which is formed in synchronism with the timing signal φ1. More specifically, each memory cell in the ROM is determined to have storage data, either the logic "1" or "0", by connecting, for example, its drain to the corresponding data line or not according to the user's specification. Accordingly, when the drain of a corresponding memory cell is connected to the data line, that is, when the data line is provided with a drain contact for the memory cell, this memory cell is turned ON in response to the word line select signal, and the common data line CD1 and the data line D1 are thus discharged. In consequence, in the case where the resistance of the discharge path is relatively small, the levels of the common data line CD1and the data line D1 quickly shift to a low level such as a ground potential of the circuit as shown by the chain lines in FIG. 5. On the other hand, when the data line is provided with no drain contact for the corresponding memory cell, no discharge circuit is formed by the memory cell, so that the levels of the common data lines CD1 and the data line D1 are left at a high level such as Vcc or Vcc-Vth.
The potential of the common data line CD1 is determined in synchronism with the shift of a timing signal φ2 to a high level, by a logic threshold voltage of a clocked inverter CN1 which constitutes a sense amplifier SA1. The output signal from the clocked inverter CN1 is transferred to an inverter N1 and held therein by charging or discharging its input capacitance Cn in according with said output signal.
As described above, the read circuit shown in FIG. 4 is arranged such that the precharge level of the data line at the time of reading is lowered by an amount corresponding to the threshold voltage of the switching MOSFET Q1 to thereby restrict the signal amplitude, and that the level of the common data line is determined by means of the charge transfer type sense amplifier SA1 constituted by the clocked inverter CN1 and the inverter N1 which are provided in close proximity to the common data line, and the sensed signal is held in the input capacitance Cn of the inverter N1 to thereby achieve a high-speed read operation.
However, the inventors of this application have found that the above-described read circuit of a micro-programmable ROM still suffers from the following problems. Namely, even though no drain contact for a selected memory cell is formed, a leakage current flows through some paths which extend through the corresponding data line and MOSFETs. Accordingly, the precharge level of the data line D1 lowers as shown in the timing chart of FIG. 5. If the precharge level of the data line gradually decreases as illustrated, since the value of the parasitic capacitance Cc of the common data line CD1 is relatively small, the level, of the common data line CD1 decrease quickly, an effect which is disadvantageous and undesirable. Since the lowering in level of the common data line CD1 leads to a reduction in the noise margin with respect to the sense amplifier, malfunction may occur in a worst case situation.
It is a primary object of the present invention to provide a semiconductor memory such as a high-speed micro-programmable ROM which is improved in the read margin.
The above and other objects and novel features of the present invention will become more apparent from the following description of the preferred embodiments thereof taken in conjunction with the accompanying drawings.
A representative one of the inventions disclosed in this application will be summarized below.
In a charge transfer type sense amplifier, a transfer gate MOSFET which is turned ON at its operating timing is employed to selectively feed back the output signal to the input terminal of the associated clocked inverter.
By virtue of the above-described means, the precharge level of a common data line which has begun to decrease due to a charge leakage or the like during an operation of reading a high level from a memory cell is pulled up to a high level through the above-described transfer gate MOSFET with the effect of increasing the operation margin of the sense amplifier.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram of one embodiment of a micro-programmable ROM according to the present invention;
FIG. 2 is a circuit diagram of a read circuit in another embodiment of the micro-programmable ROM according to the present invention;
FIG. 3 is a timing chart showing the read operation of the micro-programmable ROM shown in FIGS. 1 and 2;
FIG. 4 is a circuit diagram of a read circuit in a micro-programmable ROM developed by the inventors of this application prior to the present invention;
FIG. 5 is a timing chart showing the read operation of the micro-programmable ROM shown in FIG. 4;
FIG. 6 is a timing chart for showing another example of the read operation of the micro-programmable ROM according to the present invention;
FIG. 7 is a circuit diagram of still another embodiment of the micro-programmable ROM according to the present invention; and
FIG. 8 is a block diagram showing a further embodiment of the micro-programmable ROM according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a circuit diagram of one embodiment of a micro-programmable ROM according to the present invention. Circuit elements which constitute circuit blocks shown in the figure are fabricated on a single semiconductor substrate such as single crystal silicon, however, they are not necessarily limited thereto. P- and N-channel MOSFETs are discriminated from each other by putting the arrow to the channel (back gate) of each P-channel MOSFETs.
Although not necessarily limited thereto, the integrated circuit is fabricated on a semiconductor substrate which is defined by single crystal N-type silicon. Each of the P-channel MOSFETs is composed of source and drain regions formed on the surface of the semiconductor substrate and a gate electrode made of polycrystalline silicon which is formed on the surface of the semiconductor substrate through a thin gate indulator film so as to extend between the source and drain regions. The N-channel MOSFETs are fabricated in a P-type well region which is formed in the surface region of the semiconductor substrate. Thus, the semiconductor substrate defubes a common substrate gate for a plurality of P-channel MOSFETs which are formed thereon. The P-type well region constitutes a common substrate gate for a plurality of N-channel MOSFETs which are formed thereon. The substrate gate for the N-channel MOSFETs, that is, the P-type well region, is coupled to a ground potential of the circuit shown in FIG. 1. The substrate gate for the P-channel MOSFETs, that is, the semiconductor substrate, is coupled to a power supply voltage Vcc shown in FIG. 1.
The micro-programmable ROM in accordance with this embodiment is incorporated in a microcomputer which adopts the microprogram system and is used to store a microprogram for controlling the arithmetic processing operation carried out by the microcomputer.
A memory array M-ARY consists essentially of 128 word lines W1 to W128 which are disposed so as to extend horizontally as viewed in FIG. 1, 32 data lines D1 to D32 which are disposed vertically as viewed in FIG. 1, and 128×32 memory cells Q11 to Q30 which are respectively disposed at the intersections between the word and data lines.
Each memory cell is constituted by an N-channel MOSFET and arranged to hold storage data, either the logic "1" or "0", by selectively forming a contact for its drain by means of a mask which is optionally prepared in accordance with the user's specification. More specifically, when a memory cell is formed with a contact for its drain, this memory cell is so set that it can be brought into an ON state with a predetermined threshold voltage, and is determined to hold storage data, e.g., the logic "0". When a memory cell is formed with no contact for its drain, this memory cell is not connected to a data line, and the threshold voltage thereof is set so as to be practically infinite. Such a memory cell is determined to hold storage data, e.g., the logic "1". It should be noted that all the memory cells shown in FIG. 1 are connected to the corresponding data lines for reasons of convenience.
Referring to FIG. 1, the gates of memory cells Q11 to Q15, Q16 to Q20, Q21 to Q25, and Q26 to Q30 which are disposed along the same rows are coupled to the corresponding word lines W1, W2, W127 and W128, respectively. The drains of memory cells Q11, Q16, Q21, Q26 to Q15, Q20, Q25, Q30 which are disposed along the same columns are coupled to the corresponding data lines D1 to D32, respectively. The sources of all the memory cells in the memory array M-ARY are connected to a common source line CS and are supplied with the ground potential of the circuit.
The word lines constituting the memory array M-ARY are selected and specified by means of a word line select signal which is formed by an X-address decoder XDCR in synchronism with a signal φ1 which is formed by inverting a timing signal φ1.
The X-address decoder XDCR is activated in response to the inverted signal φ1 formed from the timing signal φ1 which is supplied from a control unit (not shown) fabricated within the same chip. The X-address decoder XDCR decodes address signals A0 to A6 which are supplied from an address register (not shown) and thereby selects a predetermined word line and raises the level of the selected word line to a high level such as the power supply voltage Vcc.
The 32 data lines constituting the memory array M-ARY are selectively connected to corresponding common data lines CD1 to CD32 through corresponding switching MOSFETs in a Y switch YS. More specifically, in the case, for example, of the data line D1 which is representatively shown in FIG. 1, this data line D1 is coupled to the source of the switching MOSFET Q5 in the Y switch YS. The switching MOSFETs Q5 to Q9 are brought into an ON state in response to the shift of a common signal Y1 to a high level to connect the corresponding data and common data lines to each other. The switching MOSFETs Q5 to Q9 not only perform the above-described Y gate function but also serve as MOSFETs for cutting off the capacitances between the data (or first data) and common data (or second data) lines.
The common data lines CD1 to CD32 are connected to the input terminals of clocked inverters CN1, CN2 which constitute charge transfer type sense amplifiers SAl to SA32, respectively. P-channel type precharge MOSFETs Q1, Q2 which are supplied at their gates with the inverted signal φ1 formed from the timing signal φ1 are respectively provided between the common data lines and the power supply voltage Vcc. These precharge MOSFETs are brought into an ON state in response to the shift of the timing signal φ1 to a low level in order to precharge the corresponding common data lines and the data lines which are selectively connected thereto.
The micro-programmable ROM in accordance with this embodiment features the arrangement of the sense amplifiers SA1 to SA32. More specifically, the sense amplifiers SA1 to SA32 are basically charge transfer type sense amplifiers each consisting of a clocked inverter CN1 (CN2) and an inverter N1 (N2) which are connected in series, i.e. cascade connected. However, the output signal from the inverter N1 (N2) is fed back to the input terminal of the clocked inverter CN1 (CN2) through a P-channel MOSFET Q3 (Q4), which constitutes a feedback circuit. Thus, in a sensing operation for determining level of each common data line which is carried out in synchronism with a timing signal φ2 after precharging has been completed, it is possible to correct a lowering or a decrease in the high level of the corresponding data line due to a charge leakage or the like, and it is therefore possible to improve the read margin in a high-level read operation of the micro-programmable ROM. Since these feedback MOSFETs Q3, Q4 are designed so as to have a relatively small conductance, there is no fear of the high-speed performance of the charge transfer type sense amplifiers being deteriorated.
FIG. 3 is a timing chart showing the read operation of the micro-programmable ROM shown in FIG. 1. The outline of the read operation of the micro-programmable ROM according to the present invention will be explained below with reference to FIG. 3.
As described above, the operation of the micro-programmable ROM in accordance with this embodiment is carried out in synchronism with the timing signals φ1 and φ2 which are supplied from a control unit (not shown) which is fabricated on the same, chip. More specifically, the rise of the timing or phase signal φ1 is defined as a precharge timing, while the rise of the timing phase signal φ2 is defined as a timing or phase period of operation for making a determination of the level of each common data line. Arithmetic operations and control operations which are generally executed in the microcomputer that includes this micro-programmable ROM are also carried out using these timing signals as basic clock signals therefor. FIG. 3 shows one exemplary cycle of each of the timing or phase clock signals φ1 and φ2 for the purpose of facilitating understanding of the read operation of the micro-programmable ROM.
Referring to FIG. 3, prior to the change of the timing signal φ1 to a high level, new address signals A0 to A6 are supplied from the address register. A timing generator circuit (not shown) detects the fact that the new address signals A0 to A6 have been supplied, and it raises the signal Y1 to a high level. In response to the rise of the signal Y1, the MOSFETs Q5 to Q9 in the Y switch are turned ON, and the data lines are thereby connected to the corresponding common data lines CD1 to CD32.
When the timing signal φ1 is raised to the high level, the inverted signal 100 1 is shifted to the low level, and the P-channel precharge MOSFETs Q1, Q2 are turned ON. Thus, precharge is effected through the path which consists of the power supply voltage Vcc--the precharge MOSFETs--the common data lines--the switching MOSFETs in the Y switch YS--the data lines. This precharging operation causes the potential of the common data lines CD1 to CD32 to rise quickly to a high level which is substantially equal to the power supply voltage Vcc. The potential of the selected data lines D1 to D32 is lower than that of the common data lines CD1 to CD32 by an amount corresponding to the threshold voltage Vth of the switching MOSFETs Q5 to Q9 in the Y switch YS and reaches a level which is substantially equal to Vcc-Vth.
When the timing signal φ1 returns to the low level, the inverted signal φ1 is raised to the high level, and the precharge MOSFETs Q1, Q2 are therefore turned OFF, thus completing the precharge operation. On the other hand, a word line select signal is formed in synchronism with the fall of the timing signal φ1, and a word line which is specified by the address signals A0 to A6 is raised to a high level. For example, when the word line W1 is specified, if there is formed a contact for the drain of a memory cell which is coupled thereto, the N-channel MOSFET which constitutes this memory cell is turned ON, and the high level of the corresponding data line which has been precharged is drawn to the ground of the circuit; therefore, the potential of the data line quickly changes to the low level as shown by the chain line in FIG. 3. If there is formed no contact for the drain of a memory cell which is coupled thereto, no precharge path is formed through this memory cell. Accordingly, the corresponding data line is supposed to maintain the high level attained by the precharge operation. However, since there is a leakage path which consists of the corresponding data line, MOSFETs and the like, the level of the data line gradually decreases as shown by the solid line in FIG. 3. The lowering in level of the data line causes the high level of the corresponding common data line to lower or decrease quickly in accordance with the potential of the data line as shown in FIG. 3.
When the timing signal φ2 is raised to the high level a little after the fall of the timing signal φ1, the clocked inverters CN1, CN2 which constitute the sense amplifiers are activated, and the sensing or reading operation of the level of the common data lines is thus started. At the same time, the P-channel type feedback MOSFETs Q3, Q4 are turned ON in response to the fall of the inverted signal φ2 formed from the timing signal φ2, and the output signals from the inverters N1, N2 are thereby fed back to the input terminals of the corresponding clocked inverters.
In the case where the common data line CD1 maintains a high level which is defined by the precharge level because the selected memory cell has the logic "1" as storage data, the corresponding sense amplifier latches the logic "1" level, that is, the sense amplifier raises the output of the inverter N1 to a high level. In consequence, the high-level output signal from the inverter N1 is fed back to the input terminal of the clocked inverter CN1 through the feedback MOSFET Q3. Accordingly, the level of the common data line CD1 which has begun to lower due to the selection of the word line is pushed up to a high level which is substantially equal to the power supply voltage Vcc as shown in FIG. 3.
Thus, the read operation of the micro-programmed ROM in accordance with this embodiment is improved in the signal margin in an operation of reading the high level, i.e., the logic "1", and it is therefore possible to prevent erroneous reading. Since the P-channel MOSFETs Q3, Q4 which respectively constitute feedback circuits for the sense amplifiers are designed so as to have a relatively small conductance, there is practically no adverse effect on the operation of reading the low level. Accordingly, there is no fear of the high-speed performance of the charge transfer type sense amplifiers being deteriorated. Thus, it is possible to realize a high-speed micro-programmable ROM having a large level margin.
FIG. 2 is a circuit diagram showing another embodiment of the micro-programmable ROM according to the present invention. In this embodiment, the arrangement and operation of each of the circuit blocks other than the sense amplifiers SA1 to SA32 are the same as those in the case of the embodiment shown in FIG. 1 and description thereof is therefore omitted.
Referring to FIG. 2, each of the sense amplifiers SA1 to SA32 in the micro-programmable ROM in accordance with this embodiment is constituted by a clocked inverter CN1 (CN2) and an inverter N1 (N2) in the same way as in the embodiment shown in FIG. 1. The drains of P-channel MOSFETs Q3, Q4 which constitute feedback circuits are coupled to the input terminals of the clocked inverters constituting the sense amplifiers, respectively, and the gates of the MOSFETs Q3, Q4 are coupled to the output terminals of the clocked inverters, respectively. The sources of these MOSFETs Q3, Q4 are mutually supplied with the power supply voltage Vcc. The feedback MOSFETs Q3, Q4 are designed so as to have a relatively small conductance in the same way as in the case of the embodiment shown in FIG. 1.
During a read operation, when the timing signal φ1 returns to the low level after the data line D1 and the common data line CD1 have been precharged, a word line select operation is conducted, and the data line D1 and the common data line CD1 are started to be discharged.
When a contact for the drain of a selected memory cell is formed, that is, when data representing the logic "0" is stored in the selected memory cell, a discharge path is formed through this memory cell. Accordingly, the high levels of the data line D1 and the common data line CD attained by the precharging operation quickly lower to reach a low level which is substantially equal to the ground potential of the circuit. On the other hand, when no contact for the drain of a selected memory cell is formed, that is, when data representing the logic "1" is stored in the selected memory, no discharge path is formed through the memory cell. However, the high level of the data line is gradually lowered through a leakage path which consists of the corresponding data line, MOSFETs and the like in the same manner as in the embodiment shown in FIG. 1. The lowering of the high level of the data line D1 causes the high level of the common data line CD1 to lower.
When the timing signal φ2 is raised to a high level, the clocked inverter CN1 is activated, and a sensing operation for determining the level of the common data line CD is started. The source of the feedback MOSFET Q3 is supplied with the power supply voltage Vcc. When a selected memory cell has the logic "1" as storage data, the output signal from the clocked inverter CN1 is shifted to a low level because of the high level of the common data line CD1. In consequently, the feedback MOSFET Q3 is turned ON, and a high level is supplied to the input terminal of the clocked inverter CN1. Accordingly, the level of the common data line CD which has begun to gradually lower in an operation of reading the logic "1" is quickly restored to the high level thereby improving margin. In an operation of reading the logic "0", if the data which was read previously was the logic "1", the feedback MOSFET Q3 is temporarily turned ON and held in this state until the timing signal φ2 is raised to the high level and the operative state of the clocked inverter CN1 has been established. However, since the conductance of the MOSFET Q3 is set so as to be relatively small, the potential at the input terminal of the clocked inverter CN1, that is, the potential of the common data line CD1, is quickly changed to the low level by the discharge operation. Accordingly, the output signal from the clocked inverter CN is raised to a high level, thus causing the feedback MOSFET Q3 to be turned OFF so as to suspend the feedback operation.
As described above, the feedback operation of each feedback MOSFET in the micro-programmable ROM in accordance with this embodiment can be controlled at a relatively high speed since its gate is controlled by means of the output signal from a clocked inverter which is coupled thereto. In the case of the embodiment shown in FIG. 1, if the previously read data was a low level signal, a low-level output signal from the inverter N1 is undesirably fed back to the input terminal of the clocked inverter CN1 in response to the rise of the timing signal φ2. However, in this embodiment the source of the feedback MOSFET is supplied with the power supply voltage Vcc; therefore, there is no fear of the low-level signal being fed back to the input terminal of the clocked inverter CN1, so that it is possible to ensure the operation margin of the sense amplifier independently of the previously read data.
FIG. 6 is a timing chart showing another example of the read operation of the micro-programmable ROM shown in FIG. 1. This timing chart greatly differs from the timing chart shown in FIG. 3 in that the electric charge which is precharged in the data line D1 is discharged relatively slowly through a MOSFET which constitutes a memory cell. More specifically, the levels of the data line D1 and the common data line CD1 gradually lower from the point of time when the potential of the word line Wn rises as shown by the chain lines in FIG. 6. This phenomenon occurs in the case where the size of the memory array M-ARY is relatively large. This is because an increase in the number of memory cells causes an increase in the parasitic capacitance of data lines to which the memory cells are coupled and, in addition, an increase in the length of each data line causes a rise in resistance of the resultant discharge path.
Referring to FIG. 6, the potential of the common data line CD1 gradually lowers as shown by the chain line, and when the potential of the common data line CD1 reaches the logical threshold voltage Vlt, the output signal DO1' is inverted from a low level to a high level. As a result, the output signal DO1 from the sense amplifier SA1 is shifted to a low level as shown by the chain line in the figure. In order to secure such an operation, it is necessary to hold the timing signal φ2 in the high level state until, at least, the potential of the common data line CD1 reaches the above-described logical theoretical voltage Vlt. If the timing signal φ2 is shifted to the low level before the above-described point of time, the clocked inverter CN1 is brought into an inoperative state, so that it is impossible to detect an input signal which is to take a low level.
The present invention is greatly effective in application to a ROM which performs an operation such as that shown in FIG. 6. This is because in such a ROM the clocked inverter is held in an operative state for a relatively long period of time and, therefore, there is a strong possibility of the clocked inverter malfunctioning unless lowering in the level of the common data line due to a leakage current is not prevented.
FIG. 7 shows still another embodiment of the present invention. The basic arrangement of this embodiment is the same as that of the embodiment shown in FIG. 1, but this embodiment differs from the first embodiment in the arrangement of the Y switch. The Y switch YS' in this embodiment is composed of switching MOSFETs Q5' to Q9' which are controlled by a Y decoder YDCR. The Y decoder YDCR raises one of the four output lines to a high level on the basis of address signals A7 and A8. As a result, eight data lines selected from the data lines D1 to D32 are coupled to common data lines CD1 to CD8, respectively. In this embodiment, eight sense amplifiers SA1 to SA8 are provided in correspondence with the common data lines CD1 to CD8, respectively. In this embodiment, MOSFETs Q5' to Q9' for shifting the precharge level can also be operated as column switches which are controlled by the Y decoder YDCR.
It should be noted that, when, in this embodiment, the data lines D1 to D32 are precharged, all the MOSFETs Q5' to Q9' are turned ON.
FIG. 8 shows a further embodiment of the micro-programmable ROM according to the present invention. In this embodiment, there are provided latches LA1 to LAi and LAj to LAk for temporarily holding address signals which are supplied to the X decoder XDCR. The latches LA1 to LAi are arranged to latch address signals A0 to Ai which are supplied from the outside of this micro-programmable ROM. The latches LAj to LAk are arranged to latch a part D01 to D0L of the output signal from the micro-programmable ROM. Thus, a part of the output signal is employed as a part of the input address signal, and this enables a series of related micro instructions to be successively read out from the micro-programmable ROM. The address signals which are latched in the latches LA1 to LAi and LAj to LAk are supplied to the X decoder XDCR in synchronism with the rise of the timing signal φ1. The X decoder XDCR selectively raises any one of the word lines W1 to Wk to a predetermined voltage level on the basis of the input address signals. The memory array M-ARY, the precharge circuit PC and the sense amplifier SA are, for example, arranged as shown in FIG. 1. Accordingly, the period during which the timing signal φ1 is at the low level is defined as a precharge period for precharging the data lines D1 to D32 in the memory array M-ARY, and discharge of a selected data line is started in synchronism with the fall of the timing signal φ1. At the same time, the non-selected data lines are also undesirably discharged due to a leakage current. In order to overcome this problem, this embodiment secures the undesirable discharge of the data lines in synchronism with the rise of the timing signal φ2 as shown in FIG. 3. Thereafter, the output signals D01 to Don are decided in response to the fall of the timing signal φ2. When the timing signal φ1 rises thereafter, a precharge operation for a subsequent read operation is started.
According to the embodiments of the present invention, it is possible to ensure that the undesirable discharge of the data lines will take place after the precharge operation has been completed. Therefore, it is possible to make the precharge period relatively short. This is because, in the case where it is impossible to ensure that the undesirable discharge of the data lines will take place after the precharge operation, it is necessary to provide a relatively long precharge period in order to precharge all the data lines to a sufficiently high voltage.
The read cycle of the micro-programmable ROM shown in FIG. 8 is determined by the period which begins at the time the timing signal φ1 falls and which ends at the time the signal φ1 falls subsequently. Accordingly, if the present invention is applied to the micro-programmable ROM, the read cycle of the ROM can be shortened by virtue of the advantage that the precharge period is relatively short. One machine cycle of a data processing device which incorporates a micro-programmable ROM is substantially determined by the read cycle of the ROM. Accordingly, application of the present invention to a micro-programmable ROM enables a reduction in the machine cycle of a data processing device which incorporates such a ROM. Thus, it is possible to provide a data processing device which is capable of operating at high speed, for example, a microprocessor, microcomputer, etc.
As has been described above, when the present invention is applied to a semiconductor memory such as a micro-programmable ROM which is employed in, for example, a microcomputer, the following advantages are provided:
(1) A charge transfer type sense amplifier which is employed in a micro-programmable ROM is provided with a feedback circuit which is adapted for selectively feeding back a high-level output signal to the input terminal of a clocked inverter which constitutes the sense amplifier at the operating timing of the sense amplifier. Thus, it is possible to correct the level of the corresponding common data line which has begun to lower or discharge due to a leakage or the like during an operation of reading a high-level signal from a selected memory cell, and this enables an improvement in the operation margin of the micro-programmable ROM at the time of reading a high-level signal.
(2) Since the above-described feedback circuit is constituted by a MOSFET which is designed so as to have a relatively small conductance, there is no fear of the high-speed performance of the charge transfer type sense amplifier being deteriorated. Accordingly, it is possible to realize a high-speed micro-programmable ROM which is improved in the read margin.
Although the invention accomplished, by the present inventors has been exemplified by way of illustrated embodiments, it, should be noted here that the present invention is not to be construed as being necessarily limited to the described embodiments and that various changes and modifications may be imparted, thereto without departing from the spirit and scope of the invention. For example, although in the embodiments memory cells are constituted by N-channel MOSFETs, P-channel MOSFETs may also be employed to constitute them. In such a case, each word line needs to be at a high level when it is not selected and at a low level when it is selected. Further, the present invention may be carried out in various forms, for example, in terms of the practical circuit configuration of the feed back circuit and the combination of data line groups.
Although the invention accomplished by the present inventors has mainly be described by way of one example in which the present invention is applied to a micro-programmable ROM which may be incorporated in a microcomputer that is an applicable field of the invention on which it is based, it should be noted here that the present invention is not necessarily limited thereto and may also be applied to various kinds of semiconductor devices, for example, one which has a processor that adopts the microprogram system. The present invention may be applied to any micro-programmable ROM that employs at least, a charge transfer type sense amplifier and to any semiconductor device that includes such a ROM.
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A semiconductor memory includes an array of memory cells wherein each memory cell is disposed at the intersection between a word line and a data line. An output line of the memory is coupled to the data line via transfer MOSFET and a data line signal detecting circuit, the latter being provided between the common data line and the output line. A precharging circuit for precharging the data line and a feedback circuit for coupling together the output and input sides of the data line signal detecting circuit are provided.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of priority to U.S. Provisional Application Ser. No. 61/112,903 entitled “PLATFORM RULER”, filed Nov. 10, 2008 by Louis A. Norelli, the entirety of which is incorporated by reference herein for all purposes.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure relates to measuring instruments, and more particularly, to an instrument for assisting in the process of plumbing, leveling, or making straight any individual or interconnected objects of any shape for use by builders, carpenters, iron workers, masons, and other tradespersons.
[0004] 2. Background of Related Art
[0005] The ruler, extension ruler, and tape measure are among the most commonly used measuring devices in the construction field. These measuring devices can also act as a guide or a gauge when building to plumb, level or straight is required. When undertaking a construction project, these qualities are essential to providing a professional and accurate product. This demand for accuracy creates challenges for a builder.
[0006] Different methods may be used by a builder to achieve plumb, level, and straight. When building to plumb or level, a builder can use a bubble level to fulfill these requirements. A bubble level's accuracy may be diminished by the length of the level relative to the length or size of the project being built. When a long horizontal span is required, the builder may use a dry line or laser to achieve better accuracy. For a vertical application, a plumb bob line or laser may used for better accuracy.
[0007] A useful skill in building to these requirements is the ability to fasten or secure material precisely and consistently. When setting up material to be fastened or secured, adjustments often need to be made to the material. However, when adjusting the material, a builder may often place the measuring device back in a tool belt, or otherwise put the measuring device aside, so that one or both hands can be used to adjust the building material. Occasionally, one hand can adjust material while the other hand holds the measuring device. When the desired dimension is found, both hands again may need to be freed to perform the fastening process. Consequently, a carpenter may be unable to assess or monitor the corresponding measurement until after the material is fastened or secured. Once the material is fastened or secured, the measurement will be checked again to ensure that the material did not move while fastening or securing the material. If the material moved during the fastening process, the fastening must be undone and the process repeated. This same procedure is needed not only for vertical applications, but for horizontal, levels and straights as well.
SUMMARY
[0008] The present disclosure is directed to a measuring instrument adapted to facilitate hands-free measuring in one or more (e.g., upright, horizontal or upsidedown) orientations. In one envisioned embodiment, the disclosed instrument includes a base, and a body projecting orthogonally therefrom. The instrument may include ruler graduations, one or more bubble level vials, one or more notches adapted to operably engage a line (e.g., string) and/or one or more pilot holes. In an embodiment, the disclosed instrument includes one or more magnets to facilitate the mounting thereof on ferrous material. A spring-loaded spike assembly may be included in the instrument to facilitate the mounting thereof on wooden material, on gypsum-based materials (e.g., wallboard such as Sheetrock®, manufactured by USG Corporation of Chicago, Ill., United States), on composite materials (e.g., polymer-based materials such as Trex®, manufactured by Trex Company of Winchester, Va., United States), and the like.
[0009] The disclosed instrument may provide utility for many different purposes, including without limitation, measuring, leveling, and squaring material. It is contemplated that an instrument in accordance with the present disclosure may be fixed in place temporarily, which may enable a builder to adjust material to its desired position, distance, and/or orientation, and fasten the material at the same time in a “hands-free” manner. It may remain in place to confirm that the fastening process was accurate.
[0010] The base may be adapted for particular purposes. For example and without limitation, the base may be magnetized which may be useful when a builder is framing metal studs or metal door frames. The disclosed device may enable a carpenter to take vertical readings without manually holding the measuring device. The disclosed device may be positioned vertically for horizontal reading, either right side up or upside down, as is typically required when constructing fascias, soffits, or free standing walls. Metal track (e.g., suspended ceilings) can be lowered or raised to the corresponding dimensions established by the builder, with the use of a dry line or a laser line.
[0011] The base of the disclosed instrument may include a screw or other threaded means for attaching to wood, and/or may include a suction device (e.g., a suction cup) for attaching the base to glass or non-magnetic metals (e.g., aluminum). The base may provide a balanced and sturdy mounting that is well-adapted to the leveling of concrete (“mud”) floors, subfloors and raised flooring, e.g., computer room floors.
[0012] In an embodiment, the disclosed hands-free measuring instrument includes a base member having a top surface and a bottom surface. An upright member is coupled to the top surface base and extends orthogonally (e.g., at a right angle) therefrom. A first magnet may be disposed on a bottom surface of the base member to enable the instrument to be magnetically secured to a ferrous workpiece. A second magnet may additionally or alternatively be disposed on a vertical edge of the upright member. The instrument includes at least one bubble level vial disposed on the instrument, and may include one bubble level disposed horizontally on the base member, and/or one bubble level disposed vertically on the upright member.
[0013] In embodiments, a spike assembly may be disposed within the instrument that is adapted to mechanically secure the measuring instrument to a workpiece. The spike assembly may include a shaft slidably disposed within the upright member. A top end of the shaft may extend upwardly beyond a top surface of the upright member. The bottom end of the shaft may include a spike tip coupled thereto. The shaft includes at least one stop member configured to limit upward and/or downward travel of the shaft.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The above and other aspects, features, and advantages of the present disclosure will become more apparent in light of the following detailed description when taken in conjunction with the accompanying drawings in which:
[0015] FIG. 1A shows a top-left perspective view of an embodiment of a hands-free measuring instrument in accordance with the present disclosure;
[0016] FIG. 1B shows a bottom-right perspective view of an embodiment of a hands-free measuring instrument in accordance with the present disclosure;
[0017] FIG. 1C shows a left-rear perspective view of an embodiment of a hands-free measuring instrument in accordance with the present disclosure;
[0018] FIG. 1D shows a right-rear perspective view of an embodiment of a hands-free measuring instrument in accordance with the present disclosure;
[0019] FIG. 2A is a rear plan view of an embodiment of a hands-free measuring instrument in accordance with the present disclosure;
[0020] FIG. 2B is a side plan view of an embodiment of a hands-free measuring instrument in accordance with the present disclosure;
[0021] FIG. 2C is a front plan view of an embodiment of a hands-free measuring instrument in accordance with the present disclosure;
[0022] FIG. 2D is a bottom plan view of an embodiment of a hands-free measuring instrument in accordance with the present disclosure;
[0023] FIG. 2E is a top plan view of an embodiment of a hands-free measuring instrument in accordance with the present disclosure;
[0024] FIG. 3A shows a top-left perspective view of another embodiment of a hands-free measuring instrument in accordance with the present disclosure;
[0025] FIG. 3B shows a bottom-right perspective view of another embodiment of a hands-free measuring instrument in accordance with the present disclosure; and
[0026] FIG. 4 shows a side, cutaway view of another embodiment of a hands-free measuring instrument in accordance with the present disclosure.
DETAILED DESCRIPTION
[0027] Particular embodiments of the present disclosure are described hereinbelow with reference to the accompanying drawings; however, it is to be understood that the disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms. Well-known and/or repetitive functions and constructions are not described in detail to avoid obscuring the present disclosure in unnecessary or redundant detail. 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 disclosure in virtually any appropriately detailed structure.
[0028] As used herein, terms referencing orientation, e.g., “top”, “bottom”, “up”, “down”, “left”, “right” and the like are used for illustrative purposes with reference to the figures and corresponding axes shown therein. However, it is to be understood that an instrument in accordance with the present disclosure may be utilized in any orientation without limitation.
[0029] With reference to FIGS. 1A-1D and 2 A- 2 E, an embodiment of a hands-free measuring instrument 100 in accordance with the present disclosure is shown. The disclosed instrument 100 includes a base 116 having an upright 110 extending orthogonally therefrom. Base 116 and upright 110 may be integrally formed, and/or may be formed in whole or in part from subassemblies. In an embodiment, base 116 and upright 110 may be formed by injection molding, as described hereinbelow. As best shown in FIGS. 2D and/or 2 E, base 116 has a substantially flattened (e.g., squat) cube shape, however, it is contemplated that base 116 may have any suitable shape, including without limitation, a squat cylindrical shape, a squat prism-shape (triangular), extruded oval shape, extruded polygonal shape, and the like. A cutout 123 is defined in base 116 and is configured to retain a first bubble level vial 122 that is mounted therein in alignment with a horizontal axis (“X”) of the base. In an embodiment, first bubble level vial 122 may be retained by at least one circular recess (not explicitly shown) defined in either end of cutout 123 that is dimensioned to receive an end of first bubble level vial 122 . It should be understood that any suitable manner of retention of bubble level vial 122 may be employed, including without limitation, adhesive, plastic welding, clip, threaded fastener, and/or interference fit.
[0030] Base 116 may additionally or alternatively include at least one pilot hole 118 defined therein. As shown pilot hole 118 is oriented along a vertical axis (“Y”) of instrument 110 , and may be oriented along a horizontal axis (“X” or “Z”) and/or an angle thereto (e.g., at a 30°, 45°, 60°, or other desired angle thereto). During use, a carpenter may utilize the at least one pilot hole 118 to scribe a mark onto a targeted material or surface thereof. Additionally or alternatively, a carpenter may pass a fastener (nail, screw, bolt, etc.) through a pilot hole 118 to affix instrument 100 to a workpiece.
[0031] As seen in FIG. 1B , base 116 includes a first magnet 144 joined to a bottom surface 135 thereof. First magnet 144 may include a permanent magnet formed from, e.g., alnico, ceramic, ferrite, neodymium, and/or samarium cobalt material. Additionally or alternatively, first magnet 144 may include an electromagnet which may be selectively activated by an actuator, such as without limitation, a pushbutton or slide switch configured to energize or de-energize an electromagnetic coil (not explicitly shown) included within instrument 100 and/or first magnet 144 . A bottom surface of first magnet 144 may be substantially aligned with a bottom surface 135 of base 116 to facilitate sturdy placement of instrument 110 on a desired surface. As shown, first magnet 144 may be substantially disc-shaped, however it is envisioned that first magnet 144 may encompass any suitable shape.
[0032] Base 116 and/or upright 110 may be formed by any suitable manner of manufacture, including without limitation, injection-molding. In an embodiment, one or more reinforcing struts 129 may be included within base 116 and/or housing 110 . At least one semicircular strut 134 may be formed within base 116 to form a cavity (not explicitly shown) that is dimensioned to retain magnet 144 by any suitable manner of retention, including without limitation, adhesive, plastic welding, clip, threaded fastener, and/or interference fit. Magnet 144 may be formed by injection molding, and may be formed in situ by direct injection of magnetic material into a cavity formed by at least one semicircular strut 134 .
[0033] As described hereinabove, an upright 110 extends perpendicularly from base 116 . Upright 110 has a generally elongate cuboid shape having a top surface 124 , a first side surface 112 (e.g., a left side), a second side surface 114 (e.g., a right side), a front edge 130 , and a rear edge 131 . Side surfaces 112 and 114 may include a curved surface, which may have a convex contour, as best seen in, e.g., FIG. 1A . In an embodiment, a front edge 130 of upright 110 is substantially aligned with a front edge 132 of base 116 , and/or a rear edge 131 of upright 110 is substantially aligned with a rear edge 133 of base 116 . During use, the right angle arrangement of upright 100 and base 116 enables a side of upright 110 and/or base 116 to be positioned against a workpiece to establish a square reference mark, as will be readily appreciated.
[0034] A cutout 121 is defined in upright 110 that is configured to retain a second bubble level vial 122 that is mounted therein in alignment with a vertical axis (“Y”) of the instrument. In an embodiment, second bubble level vial 120 may be retained by at least one circular recess (not explicitly shown) defined in either end of cutout 121 that is dimensioned to receive an end of second bubble level vial 122 . It should be understood that any suitable manner of retention of bubble level vial 120 may be employed, as described hereinabove.
[0035] Upright 110 may include at least one notch 126 defined in a front edge 130 or a rear edge 131 thereof. The at least one notch 126 has a width that is dimensioned to accept a dry line, e.g., a width in a range of about 1/32″ to about 3/32″. In an embodiment, the at least one notch 126 is positioned at an easily-remembered distance from a bottom surface of base 116 , for example without limitation, ½″ or 1 cm. In an embodiment, upright 110 and/or base 116 may include at least one laser diode (not explicitly shown) that is adapted to selectively emit visible laser light, e.g., having a wavelength of about 650 nm, and having a beam direction that is aligned with an axis (e.g., “X”, “Y”, and/or “Z” axis) of instrument 110 . In such an embodiment, instrument 100 may be used as a laser leveling device. The at least one laser diode may be adapted to cooperate with an active target that senses laser light impinging thereon to provide audio and/or visual feedback to a user. In yet another embodiment, upright 110 and/or base 116 may include at least one electromagnetic and/or electroacoustic measuring device, e.g., a laser-based or ultrasound-based rangefinder, to enable the measurement of distances greater than the dimension of upright 110 and/or base 116 .
[0036] Upright 110 may additionally or alternatively include a series of graduations 129 disposed on a first side 112 and/or a second side 114 of upright 110 , adjacent to and substantially following a front edge 130 and/or a rear edge 131 thereof. Graduations 129 may form a ruler demarcated with any suitable unit(s) of measurement, including without limitation, Imperial units (inches and/or fractions thereof), metric units (cm, mm, etc.), and/or a combination thereof. The origin (e.g., zero point) of graduations 129 may coincide with a plane described by a top surface 124 of the upright 110 , a top surface 136 of the base 116 , and/or a bottom surface 135 of the base 116 . Advantageously, by indexing the origin of graduations 129 with, e.g., a bottom or top surface of instrument 100 , measurements of material may be easily and accurately achieved in a hands-free manner. By way of example only, during use, a carpenter may affix instrument 100 to a workpiece (using magnetic or mechanical attachment) and align the workpiece to a line using graduations 129 as a reference. When the workpiece is properly aligned to the line, the carpenter may then fasten the workpiece in place. In this manner, a user may use both hands to position and fasten the workpiece, rather than attempt to hold a conventional ruler and/or level in place while both positioning and fastening the work. Significant improvements in efficiencies and precision may thus be realized by use of an instrument 100 as disclosed herein.
[0037] A second magnet 148 may be disposed on a front edge 130 and/or a rear edge 131 of upright 110 . Second magnet 148 may be formed from any suitable magnetic material, and may be formed from thin sheet magnetic material, such as without limitation, a thermoplastic permanent magnetic extrusion formed from a polymer-bonded strontium ferrite powder. Second magnet 148 may be joined to front edge 130 and/or rear edge 131 of upright 100 by any suitable manner of attachment, e.g., pressure-sensitive adhesive. As shown, second magnet 148 has an elongate rectangular shape, however, it is contemplated that second magnet 148 may include any suitable shape, and/or may additionally or alternatively include a plurality of magnetic elements disposed on a front edge 130 and/or a rear edge 131 of upright 110 .
[0038] As described hereinabove, instrument 100 may be formed from injection molded components. In an embodiment, instrument 100 may be formed from two “clamshell” halves 100 A, 100 B, each having a base half portion and an upright half portion integrally formed therewith. Instrument halves 100 A and 100 B may be formed any material suitable for injection molding, such as without limitation, polymeric materials including acrylonitrile butadiene styrene (ABS), polyvinyl chloride (PVC), polyurethane (PU), polypropylene (PP), fiber-reinforced plastic (FRP), and the like. Instrument halves 100 A and 100 B may be injection-molded as described, and/or may be formed by any other suitable manner of manufacture, e.g., machining, forging, and the like, and may be formed from metallic materials such as aluminum, stainless steel, brass, etc., and/or may be formed from wood or any other material with sufficient strength and dimensional stability for use in a measuring instrument. The instrument 100 may include a grip-enhancing coating (not explicitly shown), such as a silicone-based or rubberized coating, disposed on at least a part of an outer surface thereof.
[0039] Turning now to FIGS. 3A , 3 B, and 4 , another embodiment of a measuring instrument 200 having a spike 230 in accordance with the present disclosure is described in detail. The disclosed instrument 200 includes a base 216 having an upright 210 extending orthogonally therefrom. Base 216 and upright 210 may be integrally formed, and/or may be formed in whole or in part from subassemblies as previously described herein. A cutout 223 is defined in base 216 and is configured to retain a first bubble level vial 222 that is mounted therein in alignment with a horizontal axis (“X”) of the base. In an embodiment, first bubble level vial 222 may be retained by at least one circular recess (not explicitly shown) defined in either end of cutout 223 that is dimensioned to receive an end of first bubble level vial 222 . Additionally or alternatively, any suitable manner of retention of bubble level vial 222 may be employed, as previously described hereinabove. Base 216 may additionally or alternatively include at least one pilot hole 218 disposed therein as discussed above.
[0040] Base 216 includes a first magnet 244 joined to a bottom surface 265 thereof. First magnet 244 may include a permanent magnet formed from suitable magnetic materials heretofore discussed, and first magnet 244 may include an electromagnet which may be selectively activated by an actuator (not explicitly shown). A bottom surface of first magnet 244 may be substantially aligned with a bottom surface 265 of base 216 to facilitate sturdy placement of instrument 110 on a desired surface. An opening 239 is defined within first magnet 244 that is dimensioned to accommodate the longitudinal movement of spike tip 234 therethrough. As shown, first magnet 244 may be generally disc-shaped, however it is envisioned that first magnet 244 may encompass any suitable shape.
[0041] Base 216 and/or upright 210 may be formed by any suitable manner of manufacture as described herein, including without limitation, injection-molding. One or more reinforcing struts 229 may be included within base 216 . One or more reinforcing struts 240 , 242 may be included within housing 210 . At least one semicircular strut 233 may be formed within base 216 to form a cavity (not explicitly shown) that is dimensioned to retain magnet 244 by any suitable manner of retention, including without limitation, adhesive, plastic welding, clip, threaded fastener, and/or interference fit. Magnet 244 may be formed by injection molding, as described previously herein. As shown, second magnet 248 has an elongate rectangular shape, however, it is contemplated that second magnet 248 may additionally or alternatively include any suitable shape, and/or may include a plurality of magnetic elements disposed on a front edge 230 and/or a rear edge 231 of upright 210 .
[0042] As described hereinabove, an upright member 210 extends perpendicularly from base member 216 . Upright member 210 has a generally elongate cuboid shape having a top surface 224 , a first side surface 212 (e.g., a left side), a second side surface 214 (e.g., a right side), a front edge 230 , and a rear edge 231 . Side surfaces 212 and 214 may include a curved surface, which may have a convex contour, as best seen in, e.g., FIG. 3A . In an embodiment, a front edge 230 of upright 210 is substantially aligned with a front edge 232 of base 216 , and/or a rear edge 231 of upright 210 is substantially aligned with a rear edge 233 of base 216 .
[0043] A cutout 221 is defined in upright 210 that is configured to retain a second bubble level vial 222 that is mounted therein in alignment with a vertical axis (“Y”) of the instrument. In an embodiment, second bubble level vial 220 may be retained by at least one circular recess (not explicitly shown) defined in either end of cutout 221 that is dimensioned to receive an end of second bubble level vial 222 . It should be understood that any suitable manner of retention of bubble level vial 220 may be employed, as described herein. Upright 210 may include at least one notch 226 defined in a front edge 251 or a rear edge 252 thereof. The at least one notch 226 has a width that is dimensioned to accept a dry line. In an embodiment, the at least one notch 226 is positioned at an easily-remembered distance from a bottom surface of base 216 , for example without limitation, ½″ or 1 cm. In an embodiment, upright 210 and/or base 216 may include at least one laser diode (not explicitly shown) that is adapted to selectively emit visible laser light of about the 650 nm wavelength, having a beam direction that is aligned with an axis (e.g., “X”, “Y”, and/or “Z” axis) of instrument 210 , to enable instrument 200 to be used as a laser leveling device. The at least one laser diode may be adapted to cooperate with an active target that senses laser light impinging thereon to provide audio and/or visual feedback to a user. In yet another embodiment, upright 210 and/or base 216 may include at least one electromagnetic and/or electroacoustic measuring device, e.g., a laser-based or ultrasound-based rangefinder, to enable the measurement of distances greater than the dimension of upright 210 and/or base 216 .
[0044] Upright 210 may additionally or alternatively include a series of graduations 229 disposed on a first side 212 and/or a second side 214 of upright 210 , adjacent to and substantially following a front edge 251 and/or a rear edge 252 thereof. Graduations 229 may form a ruler demarcated with any suitable unit(s) of measurement, and may have an origin that may coincide with a plane described by a top surface 224 of the upright 210 , a top surface 236 of the base 216 , and/or a bottom surface 237 of base 216 .
[0045] A second magnet 248 may be disposed on a front edge 251 and/or a rear edge 252 of upright 210 . Second magnet 248 may be formed from any suitable magnetic material, as previously described, and may be joined to front edge 251 and/or rear edge 252 of upright 200 by any suitable manner of attachment.
[0046] Instrument 200 may include a spike 230 that is adapted to enable a user to fasten instrument 200 to a workpiece, such as without limitation, a workpiece formed from wood-based materials, masonry, concrete, drywall, composite materials, and the like. Spike assembly 230 includes a shaft 232 slidably disposed along the vertical (“Y”) axis and, more particularly, shaft 232 is disposed through the general center vertical axis of upright 210 . Shaft 232 may be slidably disposed within a series of guide openings 241 , 243 , and 247 that are defined within upright 210 and which are dimensioned to permit the free movement of shaft 232 therethrough. Opening 247 may be defined within a top surface 224 of upright 210 . Openings 241 and 243 may be defined in internal support members 240 and 242 , respectively.
[0047] A biasing member 236 provides a biasing force to bias spike 230 in an upward direction, such that, at rest, spike tip 234 is retracted to a position above (e.g., not protruding downwardly beyond) bottom surface 265 of base 216 . In this manner, instrument 200 may be used without the risk of spike tip 234 being inadvertently exposed. As shown, biasing member 236 may be a coil spring, however, the use of any suitable resilient biasing member is envisioned, such as, without limitation, a leaf spring, an elastomeric polymer biasing member, and the like. As seen in FIG. 4 , biasing member 236 is disposed between internal support member 240 and a retention clip 235 provided on shaft 232 of spike 230 , however other additional or alternative arrangements of biasing member 236 and spike 230 are contemplated with departing from the spirit and scope of the present disclosure.
[0048] Spike tip 234 is disposed at a bottom end of shaft 232 . In one embodiment, spike tip 234 and shaft 232 may be integrally formed. In another embodiment, spike tip 234 and shaft 232 may be detachably coupled by any suitable manner of coupling, e.g., threaded fastener, bayonet mount, and the like, to enable a user to selectively change spike tip 234 . The ability to change spike tips may be useful, for example, when a tip becomes worn, or, to select a tip more particularly suited to a specific material. In embodiments, instrument 200 may be provided in a kit which includes several tips, e.g., a tip that is well-suited for use in wooden materials, a tip that is well-suited for use in masonry (such tip may be formed from hardened steel or carbide), a threaded tip (not explicitly shown), and so forth. A shoulder 245 may be provided at a bottom end of shaft 232 which cooperates with a positive stop 246 that is included in base 216 to prevent over-extension of spike tip 234 in a downward direction. A stop clip 248 fixed to shaft 232 cooperates with a top support 249 of upright 210 to retain spike 230 within instrument 200 . In an embodiment, instrument 200 may be formed from two “clamshell” halves having one or more alignment nubs 238 provided along a mating edge 250 thereof that are dimensioned to engage with corresponding alignment recesses defined along an opposing edge (not explicitly shown).
[0049] Various methods may be utilized to employ spike 230 to attach instrument 200 to a workpiece. Instrument 200 may be positioned on a workpiece. Force, such as a hammer blow or finger pressure, may be applied downwardly to head 231 of spike 230 to drive spike tip 234 into the workpiece, thereby attaching instrument 200 to a workpiece for use. In another variation, where a threaded tip 234 is fitted, a user may position instrument 200 on a workpiece, and apply a downward turning motion to head 231 , which in turn, screws threaded tip 234 into the workpiece thereby attaching instrument 200 to the workpiece for use. Head 231 may include at least one indentation defined in a top surface thereof to accommodate a driving tool, such as without limitation, a flat-blade screwdriver, a Philips screwdriver, a Torx, or other screw drive types as will be familiar to the skilled artisan. Head 231 may additionally or alternatively include a hex shape to accommodate, e.g., a six- or twelve- point socket and/or a square shape to accommodate, e.g., an open-end wrench or pliers. It is also envisioned that head 231 may include knurling or other grip-enhancing features to facilitate the manipulation thereof by a user. After use, spike 230 may be withdrawn from the workpiece to free instrument 200 therefrom by e.g., applying upward force to spike 230 and/or head 231 , and/or unscrewing same when a threaded tip 234 is employed.
[0050] The described embodiments of the present disclosure are intended to be illustrative rather than restrictive, and are not intended to represent every embodiment of the present disclosure. Further variations of the above-disclosed embodiments and other features and functions, or alternatives thereof, may be made or desirably combined into many other different systems or applications without departing from the spirit or scope of the disclosure as set forth in the following claims both literally and in equivalents recognized in law.
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A hands-free measuring instrument is disclosed. The disclosed instrument includes an upright member extending perpendicularly from a base member. At least one magnet is affixed to the instrument to facilitate the mounting thereof on a ferrous workpiece. The disclosed instrument includes at least one bubble level disposed thereupon. Graduations may be provided on the instrument to facilitate measurement of linear distances. Embodiments are provided wherein a spring-loaded spike is disposed within the instrument that is adapted to secure the measuring instrument to a workpiece which may be non-ferrous. The spike assembly may be configured to work with commonly used building materials, e.g., wood, drywall, masonry, and sheet metal surfaces.
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This application is a Continuation-in-Part Application of U.S. patent application Ser. No. 457,727, filed Jan. 13, 1983, now U.S. Pat. No. 4,466,757. The disclosure of U.S. Pat. No. 4,314,773 and the prior art references cited therein are relevant to the invention disclosed and claimed herein. The complete text of U.S. Pat. No. 4,314,773 is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to equipment for levelling and densifying plastic concrete, and more particularly, to equipment which both levels and internally vibrates plastic concrete.
2. Description of the Prior Art
Before applicant's invention of the apparatus disclosed herein, a person of ordinary skill in the art suggested the desirability of pouring plastic concrete in a thickness greater than ultimately required, internally vibrating that mass of concrete and subsequently removing the excess or surcharge layer of concrete to achieve a stronger and more durable concrete deck. Structure for accomplishing that objective was not disclosed.
The prior art discloses a wide variety of mechanical internal vibration devices for compacting and densifying plastic concrete. U.S. Pat. No. 4,128,359 (Cooper) discloses a self-propelled concrete vibrator apparatus which includes a plurality of hydraulically powered vibrators positioned at evenly spaced apart intervals across the full width of a support truss. This device includes a plurality of hydraulic rams which raise and lower the plurality of vibrator units into and out of a mass of wet concrete. A second group of horizontally oriented hydraulic rams is coupled to the plurality of vibrator units and laterally displaces the vibrator units between a first and a second position. This device includes an hydraulic pump driven by an internal combustion engine and a plurality of four drive units for longitudinally translating the entire structure along the length of the concrete to be vibrated.
U.S. Pat. No. 2,223,734 (Mall) discloses a concrete vibrator which is longitudinally translatable along the length of an area of wet concrete. This device includes a vibrator carriage to which an engine is mounted. This vibrating carriage is longitudinally translatable between a first and a second position and includes a centrally mounted shaft which permits the carriage to be pivoted and to thereby partially elevate the mechanically driven concrete vibrators with respect to the surface of the wet concrete. U.S. Pat. No. 2,248,103 (Mall) discloses an attachment for a screed which includes a laterally oriented frame having a plurality of evenly spaced apart vibrators. A hand actuated lever permits an operator to simultaneously raise or lower all of the vibrators with respect to the surface of the wet concrete. U.S. Pat. No. 1,945,145 (Gordon) discloses an apparatus for compacting and dewatering wet cement. The body of this device includes a hand operated lever which permits the entire device, including a plurality of vertically oriented fixed position vibrators and the vacuum chamber of the invention, to be raised or lowered with respect to the surface of the concrete. In the raised position, the entire device can be longitudinally translated with respect to the wet concrete.
U.S. Pat. No. 2,138,103 (Jorgensen) discloses a road paving machine which includes four motor driven vibrators which are mounted in laterally fixed positions to a longitudinally translatable carriage. A strike off bar is coupled to the carriage at a position behind the vibrator unit. A hand wheel in combination with a worm gear permits the vibrator assembly to be raised or lowered with respect to the surface of the concrete. When the vibrators are lowered into the surface of the concrete and the machine is advanced, the vibrators are deflected to the rear and are dragged through the surface of the wet concrete.
U.S. Pat. No. 2,382,096 (Pierce) discloses a paving machine having a plurality of vibrator units mounted at fixed positions laterally across the face of the device. The vibrators span the entire width of the wet concrete surface to be vibrated. This device includes a concrete screed and is hydraulically powered. The plurality of vibrators are pivoted about a point and inserted at an angle into the wet concrete in a manner which permits the vibrators to travel beneath the concrete screed.
U.S. Pat. No. 2,292,733 (Baily) discloses a concrete vibrating device including a plurality of vibrators mounted at a fixed position along the entire width of the device. The vibrators are flexibly coupled to the frame which permits them to be deflected to the rear of the frame as it advances through the concrete. U.S. Pat. No. 2,461,500 (Miller) discloses an apparatus for compating concrete slabs which includes a plurality of vibrator units mounted at fixed positions laterally across the device. Each vibrator is driven by a motor coupled to a flexible shaft. The vibrators trail behind and penetrate below the surface of the wet concrete as the device is advanced through the concrete.
U.S. Pat. No. 3,555,983 (Swisher) discloses a paving grout control device which includes vibrator units positioned at evenly spaced intervals laterally across the front of the device. This device includes a comb-like structure which is immersed at a point behind the vibrating units at a predetermined depth into the paving material. U.S. Pat. No. 2,148,214 (Mall) discloses a vibrating machine which includes an inverted "T"-shaped horizontally oriented vibrating tube which is immersed into the wet concrete. U.S. Pat. No. 2,233,833 (Jackson) discloses a related device having three horizontally oriented vibrating tubes which vibrate the wet concrete. A screed also forms a part of this device which serves to level the surface of the wet concrete. U.S. Pat. No. 3,113,494 (Barnes) discloses a machine for finishing concrete surfaces and includes a mechanically vibrated screed. This device is laterally translated by a pair of manually operated winches one of which is coupled to each end of the frame of this device.
The following U.S. patents disclose inventions relevant to applicant's invention: U.S. Pat. No. 1,747,555 (Pelton); U.S. Pat. No. 2,030,315 (Noble); U.S. Pat. No. 1,898,158 (Winkler); and U.S. Pat. No. 3,413,902 (Malan).
Many of the devices discussed above are hydraulically powered and include hydraulically driven vibrator devices. Hydraulically powered vibrating equipment is comparatively heavy since the hydraulic power source is typically mounted to the frame of the vibrating device. The weight of this hydraulically powered vibrating equipment is further increased since the frame itself must be heavier to support the substantial weight of the hydraulic power source.
Virtually all of the devices described above incorporate a plurality of vibrator units which are mounted at uniformly spaced apart intervals across the full span of the supporting frame. If any particular prior art concrete vibrating device can be modified to vibrate different widths of concrete surfaces, the width of the supporting frame must be modified and a corresponding number of vibrating units must either be added to or subtracted from the device. This particular requirement not only increases the weight of the equipment which has been adapted to vibrate wide concrete surfaces, but also substantially increases the cost of a widened device since each vibrator unit is a highly specialized, high cost piece of equipment. The addition of vibrator units to a widened device also requires that the hydraulic or mechanical power unit produce an increased amount of power to drive the added vibrator units.
SUMMARY OF THE INVENTION
It is therefore a primary object of the present invention to provide a high density concrete placing and finishing machine which has the capability of initially levelling the irregular upper surface of freshly poured plastic concrete, internally vibrating and compacting the plastic concrete, and removing and remixing a surcharge layer from the internally vibrated concrete surface.
Another object of the present invention is to provide a high density concrete placing and finishing machine which includes a laterally translatable internal vibrator table and a laterally translatable carriage including levelling means and an auger positioned behind the levelling means for forming, internally vibrating and removing a surcharged layer from the plastic concrete to form a more uniform concrete deck.
Yet another object of the present invention is to provide a high density concrete placing and finishing machine which can be controlled by a single operator from a single position to rapidly and uniformly place and partially finish plastic concrete.
Breifly stated, and in accord with one embodiment of the invention, a high density concrete placing and finishing machine includes bridge means spanning the width of a plastic concrete surface and support means for maintaining the bridge means in a plane substantially parallel to the plastic concrete surface. Levelling means is coupled to and laterally translatable along the length of the bridge means within a linear segment of the concrete surface for levelling the irregular concrete surface to form a flat intermediate surface. Vibrating means is coupled to the bridge means for internally vibrating the linear segment to densify the concrete and to elevate low density material within linear segment into a surcharge layer. An auger is coupled to and laterally translatable along the length of the bridge means within the linear segment to engage the concrete at a level below the intermediate surface to displace the surcharge layer forward and out of the linear segment.
DESCRIPTION OF THE INVENTION
The invention is pointed out with particularity in the appended claims. However, other objects and advantages together with the operation of the invention may be better understood by reference to the following detailed description taken in connection with the following illustrations, wherein:
FIG. 1 is a perspective view of the high density concrete placing and finishing machine of the present invention.
FIG. 2 is a sectional view of the high density concrete placing and finishing machine depicted in FIG. 1, taken along section line 2--2.
FIG. 3 is a sectional view of the high density concrete placing and finishing machine depicted in FIG. 1, taken along section line 3--3. The dotted line depiction illustrates the internal vibrator mechanisms in the elevated position.
FIG. 4 is a partially cutaway perspective view of the opposite end of the bridge which was omitted from the FIG. 1 depiction.
FIG. 5 is a simplified, front-end view of the high density concrete placing and finishing machine of the present invention particularly illustrating the manner in which a first chain laterally translates the internal vibrator table and a second chain laterally translates the auger carriage.
FIG. 7 is a cross-sectional view of the high density concrete placing and finishing machine of the present invention particularly illustrating the aligned large and small diameter augers which form and then eliminate a surcharge level of concrete.
FIG. 6 is a partially cutaway illustration of the roller unit drive system of the present invention.
FIG. 8 is a simplified view from above illustrating the manner in which the high density concrete placing and finishing machine of the present invention is sequentially translated along the length of an area of plastic concrete.
FIG. 9 is a hydraulic system schematic diagram illustrating the hydraulic system coupled to the bridge of the high density concrete placer.
FIG. 10 is a diagram of the pneumatically powered internal vibrator system of the present invention.
FIGS. 11A-D represent a sequential depiction of the operation of the present invention on a linear segment of the plastic concrete surface.
FIG. 12 is a cross sectional view of the concrete surcharge layer formed, removed and remixed by the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In order to better illustrate the advantages of the invention and its contributions of the art, a preferred hardware embodiment of the invention will now be described in some detail.
Referring now to FIG. 1, the bridge 10 of the present invention is fabricated from a pair of spaced apart, parallel oriented support members 12 and 14. Support means in the form of paired roller assemblies 16 and 18 are coupled to the respective ends of support members 12 and 14. FIG. 4 illustrates that roller assemblies 18 coupled to the far end of bridge 10 are secured to support members 12 and 14 by roller and track assemblies to permit relative lateral displacement between bridge 10 and roller assemblies 18 thereby accommodating different concrete form spacing or variations in form spacing along the length of an area of plastic concrete. This lateral adjustment provisions is typically only required on one end of bridge 10.
Referring now to FIGS. 1 and 6, the hydraulic drive system for roller assemblies 16 and 18 is depicted. The output shaft of a hydraulic motor 20 rotates a toothed wheel which engages a chain 22 for driving the forward and rear roller assemblies 24 and 26 of the rear truck of roller assemblies 16 and 18. The FIG. 9 hydraulic circuit diagram indicates that a small internal combusion engine 28 drives a double hydraulic pump 30, one-half of which provides a source of pressurized hydraulic fluid to hydraulic motors 20. In FIG. 9, the following abbreviations are used:
RV: pressure release valves
FC: flow control valves
CS: flow switching valves
By adjusting the appropriate flow control valves, the operator can control the rate of rotation of hydraulic motors 20 and the rate of forward translation of bridge 10 with respect to the plastic concrete surface.
Referring now to FIGS. 1, 2 and 3, a laterally translatable table 32 is coupled to bridge 10 by a plurality of rollers 34 which are positioned within a pair of channels 36. A plurality of pneumatically powered internal vibrator units 38 are coupled to a frame 40 which is pivotally coupled to table 32 by hinge 42. A pneumatically actuated cylinder 44 displaces vibrator units 38 between the lowered position depicted in FIG. 3 by solid lines and the elevated position depicted in FIG. 3 by dashed lines.
Referring now to FIGS. 4 and 10, an external pneumatic air supply for actuating the pneumatic vibrators 38 and air cylinder 44 is coupled to bridge 10. A surge tank 46 assists in maintaining a uniform pressure to the pneumatically operated elements of the present invention.
A pair of spring biased hose reels 48 maintain an appropriate biasing force on air hoses 50 and 52 as table 32 is laterally translated back and forth across bridge 10.
A continuous length of chain 54 is coupled to each side of table 32 and driven in either a forward or reverse direction by hydraulic motor 56 as indicated in FIGS. 5 and 9. The operator of the high density concrete placing and finishing machine can control the speed and direction of rotation of motor 56 to control the back and forth translation of table 32. A pneumatic logic control box 58 and pilot valve assembly 60 are depicted in FIG. 10 and serve the purpose of controlling air cylinder 44 to control the pneumatic vibrator entry rate into the plastic concrete surface, the vibrator exit rate from the plastic concrete surface and the duration of internal vibration applied to the plastic concrete. Automatic control devices of this type are available from the Aro Company and designated by part no. 49000-095. Automatic control of the internal vibrators has been utilized to obtain maximum uniformity during concrete placement operations.
Referring now to FIGS. 1, 5 and 7, the auger assembly of the present invention will now be described in some detail. An auger carriage assembly 62 is translatably coupled to the lower channel of bridge support members 12 and 14 by a plurality of rollers 64. A small internal combustion engine 66 is coupled to auger carriage 62 and drives hydraulic pump 58 which produces a source of high pressure hydraulic fluid for operating hydraulic motor 70. The output shaft of motor 70 is coupled to a chain drive assembly 72 to rotate concrete levelling means in the form of a small diameter auger 74 and a large diameter auger 76. Hydraulic motor 70 is actuated by an on/off valve coupled to auger carriage 62. The operating speed of motor 70 is controlled by a flow control valve on carriage 62.
FIG. 5 illustrates that hydraulic motor 78 drives a chain 80 which is coupled to auger carriage 62. The operator of the high density concrete placing and finishing machine has access to a flow control valve and flow reversing valve which controls the speed and translation direction of auger carriage 62. The hydraulic schematic diagram depicted in FIG. 9 illustrates the manner in which the various hydraulic components of this system are interconnected.
In the preferred embodiment of the invention, auger 76 is fabricated with a four inch diameter while auger 74 is fabricated with a two inch diameter. Because these two augers are connected to a common shaft, the lower elevation differential between the lower extension of each auger blade is equal to two inches.
The operation of the present invention will now be discussed by reference to FIGS. 7, 8, 11 and 12. The high density placing and finishing machine of the present invention is initially placed on side rails adjacent to the area of plastic concrete to be operated upon. The plastic concrete is typically deposited with an irregular surface onto a bridge deck or other surface by a two cubic foot concrete bucket or from an equivalent source.
The vertical elevation of roller assemblies 16 and 18 is initially adjusted so that the blade of auger 74 engages the irregular plastic concrete surface as depicted in FIG. 11(a) at approximately the position depicted in FIG. 11(b). Air cylinder 44 is actuated to place the vibrator table in the elevated position and hydraulic motor 56 is actuated to displace the air vibrator table to the far end of bridge 10.
The machine operator then actuates hydraulic motor 70 to commence rotational motion of augers 74 and 76 followed by actuation of hydraulic motor 78 to commence the back and forth translations of auger carriage 62 with respect to bridge 10. Approximately four passes of auger carriage 62 are required to level the upper surface of the plastic concrete sufficiently to to commence internal vibration operations. During these four passes, hydraulic motors 20 on roller assemblies 16 and 18 are actuated to drive bridge 10 forward at a rate of approximately one foot per minute. Upon completion of the four passes of auger carriage 62 across the plastic concrete surface, the concrete placing and finishing machine should have advanced approximately one foot. This one foot forward translation defines a single linear segment which is subsequently internally vibrated.
Upon completion of the lateral translations of auger carriage 62, and formation of the linear segment of concrete, pneumatic vibrator table 32 is actuated to internally vibrate the entire length of the linear segment in width-wise segments equal to the table width. In the preferred embodiment of the present invention, one and seven-eighths inch internal vibrators are utilized having an effective radius of action of approximately 18 inches. The 18 inch radius of vibration effectively vibrates concrete outside of the one foot wide linear segment to provide overlap between sequential passes of the device over adjacent linear segments.
The machine operator initiates the internal vibration operations by actuating pneumatic control box 58. This device automatically controls air cylinder 44 to cause the internal vibrators to penetrate into the concrete at a predetermined rate, to internally vibrate the concrete for a determined length of time, and to retract the internal vibrators from the plastic concrete at a predetermined rate. When the internal vibration operation of a widthwise segment of concrete has been completed, the operator actuates vibrator table drive motor 56 to reposition vibrator table 32 over an adjacent widthwise segment of plastic concrete where the automatic internal vibration procedure is repeated. This series of operations is repeated until the entire length of a linear segment of concrete has been internally vibrated. At that point, the roller assembly hydraulic motors are reactuated and the machine is displaced at a forward rate of approximately one foot per minute while auger carriage 62 is repeatedly laterally displaced with respect to bridge 10.
The objective of the procedure described above can be explained by reference to FIG. 12. The internal vibration of plastic concrete causes air, water and fine latents to form an upper layer on the plastic concrete while fine sandy material forms an adjacent layer immediately below that first layer. Each of these two layers is approximately one-eighth of an inch in depth. At some distance below these two layers, the concrete assumes a substantially uniform density. The non-uniformity of the upper layer of plastic concrete following internal vibration operations produces a cured concrete material having a substantially weaker outer layer which is subject to rapid wear and fast deterioration.
The present invention eliminates this undesirable layer and produces a totally uniform concrete deck by initially forming an excessively deep thickness of concrete, by subsequently internally vibrating that excessively thick layer and by sequentially removing and remixing that excess or surcharge layer of concrete. This process is best illustrated by the sequentially related diagrams A-D of FIG. 11.
FIG. 11A illustrates the highly irregular surface of freshly poured plastic concrete. FIG. 11B illustrates that multiple passes of levelling means in the form of a plow or auger blade 74 forms a comparatively level plastic concrete surface indicated by reference letter "B." FIG. 11C illustrates that internal vibrator units 38 penetrate into the levelled plastic concrete surface to internally vibrate the concrete. FIG. 11D illustrates that as bridge 10 is translated forward into the previously internally vibrated area of concrete lying within a give linear segment, the surcharge layer of concrete lying between the area designated by reference letters B-C is engaged by the blades of large diameter 76. The auger blade displaces the surcharge layer B-C forward to create a new, lower level concrete surface designated by reference letter C. The approximately two inch thick surcharge layer B-C containing the undesirable materials depicted in FIG. 12 is remixed by auger 76 and displaced forward into an adjacent linear segment which is simultaneously being levelled and mixed by smaller diameter auger 74.
The unique interaction of spaced apart, different diameter auger blades 74 and 76 coupled with an internal vibration step essentially eliminates the non-uniform concrete layer depicted in FIG. 12 and creates a concrete slab having uniform strength and density and a substantially greater durability than cured concrete produced according to prior art methods.
After the high density concrete placer described above has completed its operations on a plastic concrete surface, conventional commercially available concrete finishing equipment such as an Allen Engineering HD Screed is used to complete concrete finishing operations.
It will be apparent to those skilled in the art that the disclosed high density concrete placing and finishing machine may be modified in numerous ways and may assume many embodiments other than the preferred forms specifically set out and described above. For example, levelling means 74 has been described as having the configuration of a smaller diameter auger coupled to a common shaft incorporating a larger diameter auger. Levelling means 74 could also take the form of a plow or blade mounted perpendicular to the direction of travel of auger carriage 62 or inclined at an angle thereto to displace concrete either laterally or forward as the levelling operation proceeds. Similarly, auger carriage 62 could house levelling means 74 and auger 76 in an adjacent or side by side relationship and the required forward to rear effective spacing could be provided by displacing bridge 10 back and forth with respect to a single linear segment of concrete. Internal vibration could also be provided by a plurality of internal vibrator mechanisms spaced at uniform intervals across the entire length of bridge 10. The utilization of a laterally displaceable vibrator table of the type disclosed in FIG. 1 reduces the overall weight of the device, requires a smaller supply of compressed air and reduces the overall system costs. Alternatively, the internal vibration operation could be accomplished by a second individual utilizing a single internal vibrator mechanism to manually accomplish the internal vibration procedure at an appropriate time. The internal vibration mechanism disclosed in FIG. 1 has been attached to bridge 10 primarily to eliminate the requirement for a second laborer and to accomplish the concrete finishing operations at a more rapid rate. The essence of applicant's invention is depicted in FIG. 11 and is not inherently limited to any particular structure of the type depicted in FIG. 1. Numerous other combinations of equipment, used separately or in combination, could readily be assembled to practice applicant's invention as described. In addition, the internal vibration operation could be performed before auger 74 intially levels a section of concrete. Accordingly, it is intended by the appended claims to cover all such modifications of the invention which fall within the true spirit and scope of the invention.
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The present invention levels freshly poured concrete, internally vibrates a linear segment of that concrete and then moves forward and remixes a surcharged concrete layer to yield a more uniformly dense mass of concrete. The apparatus includes a bridge spanning the width of a plastic concrete surface and is suppported above and maintained substantially parallel to the plastic concrete surface. A small diameter auger is coupled to a carriage suspended beneath the bridge and is laterally translatable back and forth along the length of the bridge within the linear segment of concrete to level the irregular concrete surface to form a flat intermediate surface. An internal vibrator module is laterally translatable along the bridge for internally vibrating the plastic concrete to densify material within the linear segment into a surcharge layer. A large diameter auger is coupled to the carriage behind the small diameter auger to engage the concrete at a level below the intermediate surface and displace the surcharge layer forward and out of the linear segment as the bridge is translated forward with respect to the linear segment.
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The present invention is generally directed to automatic hot water recovery apparatus for the conservation of thermal energy, and is more particularly directed to a pressurized plumbing system and water heater apparatus for substantially reducing the thermal losses from unused hot water remaining in hot water lines.
It is well known that a considerable amount of thermal energy is wastefully dissipated from the hot water lines which provide intermittent hot water to plumbing fixtures, such as domestic wash basins, dishwashers and clothes washers.
The earliest attempt to reduce this thermal loss included the insulating of hot water heaters and hot water lines, which feed the plumbing fixtures. While the insulating of hot water lines slows the dissipation of heat, over an extended period of time no savings occurs if the intermittent use of hot water through the line still allows the hot water line to cool to ambient temperature.
Devices have been devised to actually recover the hot water remaining in hot water lines after the use of a fixture by drawing the hot water back into the hot water tank. Because the hot water is removed from the lines, there is an actual reduction in the amount of heat loss rather than just a slowing of the heat loss as occurs through the use of insulation alone.
An example of this type of system was disclosed in U.S. Pat. No. 4,321,943, which utilizes a pressure reducer in combination with the hot water heater and a bridge coupling, or conduit, interconnected between the hot and cold water lines of a hot water system proximate each of the fixtures therein. In operation, the pressure reducer lowers the pressure in the water heater tank and water pipe when cold water outlet is opened, in order to produce a flow of cold water from the cold water pipe into the hot water pipe thus forcing the hot water in the lines back into the hot water tank. This system relies on the creation of an air pocket in the heater tank, working as a pneumatic spring to return the hot water. In operation, the cold water backflow, forcing hot water back into the tank, continues until the pressure in the tank rises to equal the pressure in the cold water line.
Although workable, this system has a number of disadvantages, particularly in view of the fact that the system is intended for use in domestic installations and expected to function for periods of ten, or more years, without service or maintenance.
Because the system relies on an air pocket being developed within the tank, it is faced with the inherent problem of the air being dissolved in the water. When this occurs, there is not sufficient room in the tank in order to draw all of the hot water back into the tank during the backflow cycle of the system. This represents a gradual degradation in the effectiveness of the system and as the air pocket in the tank diminishes to zero, so does the effectiveness of the system.
Another disadvantage of the system in domestic use is the overall effectiveness of the system over a long period of time. It must be appreciated that once installed, the average homeowner is not motivated to provide any maintenance therefor, unless he or she has an indication of malfunction.
It is apparent from the system disclosed in U.S. Pat. No 4,321,943, that there is no easy way that a homeowner could determine, after an indeterminate period of time, whether the system is operating efficiently. Energy savings from such a system is important over long periods of time; that is, the energy saved during each recycle of water back into the water heater is rather small, but the accumulative effect over many, many years provides the incentive for installing such a system. Thus, it is imperative that not only must the system be reliable, it must be conveniently and easily checked as to its operability over periods of time measured in years.
This lack of long term effectiveness was recognized in U.S. Pat. No. 4,518,007, in which there is disclosed a heat recovery system utilizing a separate discreet insulated tank for use in conjunction with a water heater. The advantage of this later system resides in the fact that it eliminated a disassembly of the water heater tank and the installation of extra pipes for installation of the system.
As can be seen from the subject patent, the apparatus disclosed is quite complicated, using a piston with convoluted faces to effect a differential in pressure thereacross and an internal volume of air trapped inside to act as an airspring. As in the prior system, this later developed separate heat recovery tank relies on an internal trapped air pocket which must be sealed from hot water for periods of many years. It also has the disadvantage of being unserviceable by the homeowner, who also has no way of determining whether the piston disposed therein is operating in a normal function and that the automatic hot water recovery system is providing the energy conservation it was designed initially to produce.
The present invention, however, constitutes an automatic hot water recovery system which is not only simple in operation, but its operation is easily monitored without the use of special instruments or tools, or special instructions. Because of this, the present system is mos suitable for installation in domestic applications where little or no maintenance will be provided thereto for the life of the water heater, without an obvious display of its operability to a homeowner.
SUMMARY OF THE INVENTION
Water heater apparatus, in accordance with the present invention, which is suitable for use with a pressurized plumbing system having separate hot and cold water lines and conduit means, interconnected between the hot and cold water lines, for enabling cold water to pass from the cold water line into the hot water line, includes tank means for containing a volume of water under pressure greater than atmospheric pressure having an outlet configured for coupling to the hot water line. Heating means are provided for heating water contained in the tank means and water inlet means are provided having fitting means for coupling to a cold water supply line and a cold water line. The water inlet means is operational for introducing water to and withdrawing water from the tank means and includes piston means for displacing water within the tank means to both enable hot water, heated in the tank means,.to flow into the hot water line from the tank means and hot water, from the hot water line, to return into the tank means. In addition, the water inlet means further includes means for exerting atmospheric pressure on a portion of the piston means. As will be described hereinafter in greater detail, this eliminates the need for an internal air pocket as required by prior art devices. Because one side of the piston is subjected partially to atmospheric pressure, while an opposite side of the piston is subjected to the total pressure in the system when water is not being withdrawn therefrom, the piston acts to displace water within the tank and return hot water from the hot water lines into the tank means.
Importantly, in accordance with the present invention, indicator means are included for providing an indication of the piston means displacement operation in a manner which is visible from the outside of the tank means. In this manner, operation of the system can easily be checked by the observation of the indicator means without the use of special tools or instructions.
More particularly, the inlet means includes cylinder means disposed within the tank means for both guiding the piston means and enabling movement of the piston means to displace water within the tank means. In addition, the means for exerting atmospheric pressure on a portion of the piston means includes a rod attached to the piston means for movement therewith, with the rod extending outside of the tank means. Importantly, the portion of the rod extending outside of the tank means operates as the indicator means. In this manner, operation of the piston is easily noted from outside of the tank means by observation of the rod moving in and out of the tank.
More particularly, the present invention includes a seal disposed between a perimeter of the piston means and an inside wall of the cylinder means and the closed cylinder means includes group slot means disposed in one end of the cylinder means for both enabling flow of water out of the cylinder means to displace water in the tank means outside of the closed cylinder means and enabling water to flow out of one end of the closed cylinder means when the piston resides at the one end of the cylinder means.
The fitting means may be disposed in an opposite end of the closed cylinder means for enabling water disposed be&ween &he closed cylinder means opposite end and the piston means to flow into the cold water line when the piston means moves toward the closed cylinder means opposite end. This piston means movement toward the closed cylinder means opposite end causes displacement of water within the tank into the closed cylinder means through the slots means.
In terms of a pressurized plumbing system, the present invention includes tank means for containing a volume of water under pressure greater than atmospheric pressure and heating means for heating the water contained in the tank means. The hot water line is provided which is coupled to the tank means and extends to at least one plumbing fixture.
Water inlet means having fitting means for coupling to a cold water supply line and a cold water line are provided for introducing water to and withdrawing water from the tank means. The water inlet means includes piston means for displacing water within the tank means to both enable hot water, heated in the tank means, to flow into the hot water line from the tank means and hot water, from the hot water line, to return into the tank means. More particularly, the water inlet means further includes means for exerting atmospheric pressure on a portion of the piston means. Also provided is a cold water line coupled to the tank means and extending to the plumbing fixture and conduit means, interconnected between the hot water and cold water lines, for enabling cold water to pass from the cold water line into the hot water line. The conduit means is distally disposed from the tank means.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages and features of the present invention will appear from the following description when considered in conjunction with the accompanying drawings, in which:
FIG. 1 is a diagrammatic drawing of the pressurized plumbing system and water heater apparatus in accordance with the present invention, generally showing the exterior of the tank hot and cold water lines with a conduit therebetween proximate a plumbing fixture. Importantly shown, is an indicator protruding from the top of the tank means by which continuous monitoring of the operability of the system can be visually maintained;
FIG. 2 is a cross-sectional view of an enlarged portion of the top of the tank showing greater detail. Inlet means in accordance with the present invention which includes a closed cylindrical cylinder within the tank means and a piston slidably disposed therein; and
FIG. 3 is another cross-sectional view showing operation of the inlet means, in accordance with the present invention, with the piston disposed at one end of the cylindrical tube in a position where water entering from an inlet can pass thereby through slots into the remainder of the tank.
DETAILED DESCRIPTION OF THE INVENTION
Turning to FIG. 1, there is a pressurized plumbing system 10, in accordance with the present invention, which generally includes a tank 12 having a heater 14, a hot water line 16 coupled to the tank 12 and extending to at least one plumbing fixture 20. A cold water line 22 coupled between the hot water tank inlet means 24 and the fixture 20 and a conduit 28 intercoupled between the hot water line 16 and the cold water line 22 proximate the plumbing fixture 20 provides means for enabling cold water to pass from the cold water line 22 into the hot water line 18, as will be hereinafter described in greater detail.
The pressurized plumbing system 10 diagrammed in FIG. 1 thus illustrates a portion of a domestic plumbing system, with the tank 12 providing means for containing a volume of water under pressure greater than atmospheric pressure and the heater 14 which may be gas or electric, providing means for heating the water contained in the tank 12.
An important feature of the present invention is the use in which the operation of the system may be monitored. As shown in FIG. 1, an end portion 30 of a movable rod 32 provides an indication of the system operation, as will be hereinafter described in greater detail.
The conduit 28 may have a smaller diameter than the hot and cold water lines 16, 22, or a flow restricter 36 may be provided to control the water flow between the cold water line 22 and the hot water line 16, as will be hereinafter described.
The water heater apparatus 40 which includes the tank 12, heater 14 and water inlet means 24, is shown in cross-sectional view in FIGS. 2 and 3, is shown in cross-sectional view in FIGS. 2 and 3, only the top portion of the tank being shown to more clearly illustrate the structure and function of the inlet means 24. The inlet means 24 generally includes a fitting 46, a cylinder 50, a piston 52, with the rod 30 attached thereto in any conventional manner. A line 54 interconnects the inlet means with the cold water line 22. An end cap 56 with a dip tube 56a is fitted to the cylinder 50 to enable the inlet means 24 to introduce water proximate the heater 14.
More particularly, the fitting 46 may include conventional plumbing threads 58 disposed in a top 60 of the cylinder 50 which provides means for coupling the water inlet means 24 to the water supply line 62 and the cold water line 22 through the line 54.
In order to introduce water to and withdraw water from the tank 12, the water inlet means 24 includes the piston 52 which is slidably mounted in the cylinder 50, with a piston seal 64 disposed between a perimeter 66 and an inside wall 70 of the cylinder 50. In operation, as will be hereinafter described, the piston 52 provides means for displacing water within the tank 12 which enables hot water, heated in the tank 12, to flow into the hot water line 16, and hot water, from hot water line 16, to return into the tank 12. During this operation, heat piston 52 moves from a position approximate one end 74 (FIG. 3) of the cylinder 50 to an opposite end 76 (FIG. 2) carrying along with it the rod 30 which also provides means for guiding the piston 52 within the cylinder by engagement therewith through a top seal 80. Since the end 32 of the rod 32 is visible from outside of the tank, the movement of the piston and the rod 30 is easily observed. Should the piston fail to move during operation of the system, malfunction is easily detected.
It should be appreciated that a cylinder piston and rod may be constructed of any suitable material that can withstand the temperature of typical domestic hot water heaters. Of course, for industrial applications, higher temperature materials may be required. Importantly, however, since there is no great pressure differential across the cylinder, a material able to withstand high pressures not required. The only portion of the tank subjected to pressure is the top 60.
It is important to recognize that the rod not only serves as an indicator of the system operation, but also provides means for exerting atmospheric pressure on a portion of the piston 52, which is fundamental to the operation of the water inlet means 24.
Initially, before use of the fixture 20, the piston 52 resides at the opposite end 76 of the cylinder 50 (FIG. 2). When the fixture 20 is utilized to draw hot water through the hot water line 16, a drop in pressure in the water tank 12 causes water to flow through the fitting 46 and between the piston and top 60, thereby forcing the piston 50 downward in the cylinder 50 as shown by the arrow 82 in FIG. 2. Slots 86, or the like, disposed in cylinder end 74 enable water flow therefrom into the body 90 of the tank via the dip tube 56a and thereafter into the hot water line 16. In this manner, the piston displaces water within the tank 12 to enable hot water, heated in the tank 12, to flow into the hot water line 16. This continues until the piston 52 reaches the end 74 of the cylinder 50 as shown in FIG. 3. In this position, the slots, or openings 86 are sized to enable continued water flow past the piston 52 and into the body of the tank 90.
It should be appreciated that the volume of the cylinder 50 is made to capacity, approximately equal to the anticipated volume of water to be returned from the hot water line 16. When hot water is no longer drawn from the hot water line 16, the pressure in the tank hot water line and cold water line 22 become equal and exert an upward force on the bottom 96 of the piston 52. As hereinbefore pointed out, the rod 50 exerts atmospheric pressure on a portion of a top 98 of the piston 52.
Water enters the hot water line through the conduit 28 from the cold water line 22 connected to the fitting 46 through line 54. The conduit 28 may be of a smaller diameter than the hot and cold water lines 16, 22, in order to limit mixing of cold water with hot water when hot water is withdrawn from the hot water line 16 via the fixture 20. Alternatively, a restriction 36 may be used to so limit the water flow.
Because the bottom 96 and top 98 of the piston 52 are of the same area and a portion of the piston 98 is subjected to atmospheric pressure, the total force on the bottom of the piston 96 is less than the force on the top of the piston 98, consequently, the piston will move toward the top 60 of the cylinder, drawing water through the slots 86 and displacing water within the tank which in turn causes the hot water in the hot water line 16 to return into the tank 12. Piston movement continues until it reaches the top of the cylinder 50, thus withdrawing all of the hot water from the hot water line if the volume of the cylinder 50 is equal to the volume of water in the hot water line 16. Importantly, there is no required air pocket within the tank or within the inlet means as is required by prior art devices. The only moving portion of the system is the piston 50 and rod 30 which can be selected to provide long term reliability.
It is to be appreciated that the seal 80 may be a typical O-ring seal, or it may include a diaphragm type seal, not shown, or any other suitable arrangement.
As hereinbefore noted, the rod end 32 provides an indication of the operation of the system. When water is withdrawn from the tank, the rod protruding from the tank 12 is substantially less than when the system has recovered all the hot water from the hot water line 16. In many instances, where the water heater is installed in a garage location, a casual look will reveal the operation of the system. On the other hand, if the tank 12 is disposed in a separate locker, or the like, operation can easily be determined by a brief examination of the tank.
Although there has been hereinabove described a particular arrangement of a pressurized plumbing system and water heater apparatus, in accordance with the present invention, for the purpose of illustrating the manner in which the invention may be used to advantage, it should be appreciated that the invention is not limited thereto. Accordingly, any and all modifications, variations, or equivalent arrangements which may occur to those skilled in the art, should be considered to be within the scope of the invention as defined in the appended claims.
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Automatic hot water recovery apparatus is provided for conserving the energy in a pressurized plumbing system and water heater apparatus by recovering hot water from hot water lines extending to plumbing fixtures remotely disposed from the water heater. A piston is provided within the water heater to enable the displacement of water therein and to act as an indicator of system operation.
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BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to the interconnection of voice response units to secure the collection of confidential data. More specifically, the invention relates to initiating a bridge call with a caller, indentifying the caller by an Automatic Number Identification field, validating the confidential data input, updating the record in a call (CMR) management repository and terminating the call.
BRIEF SUMMARY OF THE INVENTION
Description of the Related Art
In U.S. Patent Application 20100054431-A1, Jaiswal describes a system and method to select and retrieve contact center transactions stored in a queuing mechanism with an interactive voice system configured to accept at least one call and dynamically populate a web form with call data associated with the one call. When a caller calls into an IVR system, the incoming call may be associated or otherwise linked to the call via a unique identifier. The caller's phone number, as well as information associated with the caller's phone number, such as an address, account number, etc., may be obtained automatically upon identifying the incoming call. The call data or parts thereof may be encrypted using, e.g., secure transaction technologies. This ensures that confidential and/or sensitive information is secured.
In. U.S. Pat. No. 8,315,363-B2 Phelps describes a system and method of network call recording with identification of a call received at the Voice Response Unit (VRU) as a call matching one or more parameters of the call recording request; and using available digital signal processing resources of the VRU to record one or more specified portions of call secure communication capability with encryption is implemented to accommodate confidential or sensitive data.
In U.S. Patent Application 20130129073 A1, Peterson describes systems and methods of parallel media communication in contact handling systems, with Interactive Voice Response (IVR) unit and confidential communications.
The above patents, US 20100054431-A1, U.S. Pat. No. 8,315,363-B2, and US 20130129073 A1 by Jaiswal, Phelps, and Peterson, shall be incorporated herein by reference in their entireties.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a flowchart illustrating the basic operational steps of an embodiment of the present invention; and
FIG. 2 is a system of a computer hardware and software product for use in implementing portions of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
For a better understanding of the present invention, together with other and further objects, advantages, and capabilities thereof, reference is made to the following disclosure and the appended claims in connection with the above-described drawings.
In FIG. 1 , there is shown a flowchart depicting steps performed in practicing one embodiment of the invention. In step 1 , a caller using a telephone device dials a number that connects to a merchant's Interactive Voice Response unit. The number may be a toll-free number.
In step 2 , a merchant's Interactive Voice Response unit validates the caller leveraging the use of an ANI, Automatic Number Identification and the caller's response to challenge questions, such as the last four digits of their social security number. This ANI is the telephone number from which a call was made. A caller is then prompted to choose the type of transaction a caller wants to complete. The options may include invoices, orders, or payments.
In step 3 , the caller chooses to make a payment transaction using a credit card.
In step 4 , the Merchant's Interactive Voice Response unit determines whether the customer's credit card number has been previously stored. The credit card number is the confidential data that the invention allows to be uniquely collected. The merchant does not have visibility to this confidential data, but does have visibility to a key that points to the data stored with the vendor. The key is an alphanumeric string.
In step 5 , if the credit card number has been previously stored, the vendor will process the payment using the merchant's key to point to the confidential credit card number that it has previously stored.
In step 6 , if the credit card number is not currently stored at the vendor, a bridge call is initiated to the vendor using an Automatic Number Identification from a pool of special numbers. A merchant must have a sufficient pool of special numbers so that re-use does not compromise caller identity. A bridge call is defined herein as a call between a merchant's IVR and a vendor's IVR without the need to loop the caller back to the merchant upon collection of the confidential data. Using the bridge call allows the merchant to keep control of the call even if the call fails at the vendor. Using the bridge call eliminates routing a call to the vendor and then back again to the merchant. A record is created in the Call Management Repository (CMR) as shown in FIG. 1 .
In step 7 , a caller's credit card data, including card number and expiration date, is entered by the caller in the vendor's Interactive Voice Response unit. The caller may use a numeric key pad on the telephone or alternatively speak the data numbers into the microphone of the telephone.
In step 8 , the credit card data is validated and stored into a vendor's repository, referred to as an electronic wallet and a key is created that is specific to the confidential credit card data.
In step 9 , the corresponding key is returned to the merchant, referred to as the wallet key, and the merchant's record is updated with this key.
In step 10 , the determination is made to end the call or not to end the call, depending on whether the transaction was successful.
In step 11 , if the credit card data was successfully collected, the merchant can proceed to use the key to reference the card and process a payment.
In step 12 , if the credit card data was not successfully collected, the call is routed to the merchant's own agent to provide customer service.
FIG. 2 shows a block diagram of internal components 800 and external components 900 of a computer 110 , in accordance with an illustrative embodiment of the present invention. It should be appreciated that FIG. 2 provides only an illustration of one implementation and does not imply any limitations with regard to the environments in which different embodiments may be implemented. Many modifications to the depicted environments may be based on design and implementation requirements.
Computer 110 is representative of any electronic device capable of executing machine-readable program instructions. Computer 110 may be representative of a computer system or other electronic devices. Examples of computing systems, environments, and/or configurations that may be represented by computer 110 include, but are not limited to, personal computer systems, server computer systems, thin clients, thick clients, laptop devices, smartphones, multiprocessor systems, microprocessor-based systems, network PCs, minicomputer systems, and distributed cloud computing environments that include any of the above systems or devices.
Computer 110 includes a set of internal components 800 and external components 900 . Internal components 800 includes one or more processors 820 , one or more computer-readable RAMs 822 and one or more computer-readable ROMs 824 on one or more buses 826 , and one or more operating systems 828 and one or more computer-readable tangible storage devices 830 . The one or more operating systems 828 , functions in computer device 110 are stored on one or more of the respective computer-readable tangible storage devices 830 for execution by one or more of the respective processors 820 via one or more of the respective RAMs 822 (which typically include cache memory). In the embodiment illustrated in FIG. 2 , each of the computer-readable tangible storage devices 830 is a magnetic disk storage device of an internal hard drive. Alternatively, each of the computer-readable tangible storage devices 830 is a semiconductor storage device such as ROM 824 , EPROM, flash memory or any other computer-readable tangible storage device that can store a computer program and digital information.
Internal components 800 also includes a R/W drive or interface 832 to read from and write to one or more portable computer-readable tangible storage devices 936 , such as a CD-ROM, DVD, memory stick, magnetic tape, magnetic disk, optical disk or semiconductor storage device. Functions in computer 110 can be stored on one or more of the respective portable computer-readable tangible storage devices 936 , read via the respective R/W drive or interface 832 and loaded into the respective hard drive 830 .
Internal components 800 also includes audio adapters or interfaces 838 such as a sound card, hardware mixer, amplifier, or other adapters or interfaces for receiving audio signals from microphones.
Internal components 800 also includes network adapters or interfaces 836 such as a TCP/IP adapter cards, wireless wi-fi interface cards, or 3G or 4G wireless interface cards or other wired or wireless communication links. Functions in computer 110 can be downloaded to computer 110 from an external computer via a network (for example, the Internet, Cloud 24, a local area network or other, wide area network) and respective network adapters or interfaces 836 . From the network adapters or interfaces 836 . The network may comprise copper wires, optical fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers.
External components 900 can include a computer display monitor 920 , a keyboard 930 , and a computer mouse 934 . External components 900 can also include touch screens, virtual keyboards, touch pads, pointing devices, and other human interface devices. Internal components 800 includes device drivers 840 to interface to computer display monitor 920 , keyboard 930 and computer mouse 934 . The device drivers 840 , R/W drive or interface 832 and network adapter or interface 836 comprise hardware and software (stored in storage device 830 and/or ROM 824 ).
Aspects of the present invention have been described with respect to block diagrams and/or flowchart illustrations of methods, apparatus (system), 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 instructions. These computer 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 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.
The aforementioned programs can be written in any combination of one or more programming languages, including low-level, high-level, object-oriented or non object-oriented languages, such as Java, Smalltalk, C, and C++. 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 a remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including 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). Alternatively, the functions of the aforementioned programs can be implemented in whole or in part by computer circuits and other hardware (not shown).
The foregoing description of various embodiments of the present invention has been presented for 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. Such modifications and variations that may be apparent to a person skilled in the art of the invention are intended to be included within the scope of the invention as defined by the appended claims.
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A method and system of collecting confidential data by means of initiating a bridge call with a caller and a vendor. The bridge call allows an interconnection between a merchant's Interactive Voice Response unit (IVR) and a vendor's Interactive Voice Response unit (IVR) without the need to loop the caller back to the merchant after the confidential data is collected. An Automatic Number Identification field is present on each call to identify the caller. A caller enters confidential data into a vendor's IVR using the telephone. Once the confidential data is validated and stored, the vendor updates a call management repository record and terminates the bridge call.
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BACKGROUND OF THE INVENTION
The present invention relates to method for the preparation of a rare earth-cobalt based permanent magnet or, more particularly, to an improved method for the preparation of a rare earth-cobalt based permanent magnet with a relatively low content of copper as an additive element yet having a high coercive force and good squareness of the hysteresis loop.
As is well known, conventional rare earth-cobalt based permanent magnets are usually prepared with admixture of additional alloying elements of copper and iron in amounts of, for example, from 10 to 20% by weight and 5% by weight or larger, respectively, in consideration of the improvements obtained by the addition of copper to increase the coercive force and of iron to increase the residual magnetization of the magnets.
From the standpoint of the compatibility of these two magnetic parameters of a magnet, the addition of copper in a large amount is rather disadvantageous for the increase of the residual magnetization so that it would be very advantageous for rare earth-cobalt based permanent magnets if a high coercive force could be obtained even by the addition of a relatively small amount of copper, for example, less than 10% by weight.
It has been, however, a generally accepted conclusion that a sufficiently high coercive force can hardly be obtained with a rare earth-cobalt based permanent magnet of the alloying composition in which the content of copper as an additive element is low enough not to exceed 10% by weight or, in particular, not to exceed 8% by weight. There have been, of course, several attempts to overcome this difficulty. For example, certain improvement can be obtained in the coercive force of the magnet by a very much prolonged heat treatment or aging. Alternatively, the coercive force of a rare earth-cobalt based permanent magnet can be improved to some extent by the addition of certain alloying elements including zirconium, titanium, manganese, hafnium, tantalum and the like to the alloy composition for the powder metallurgical preparation of the magnet followed by heat treatment involving multi-step aging or continuous cooling-down. The highest coercive force of the magnets obtained by these improved methods unfortunately cannot exceed 7 kOe with an unavoidable problem of poor squareness of the magnetic hysteresis loop as one of the important characteristics of permanent magnets so that the permanent magnet prepared by these methods is not satisfactory in respect of the general performance of the magnets.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a means for the preparation of a rare earth-cobalt based permanent magnet having a very high coercive force and excellent squareness of the hysteresis loop despite the relatively low content of copper in the alloy composition.
The method of the present invention established as a result of the extensive investigations undertaken by the inventors utilizes a specific scheme of the heat treatment or aging treatment undertaken in two or more successive steps which is effective in improving the coercive force and the squareness of the hysteresis loop of the magnet.
Thus, the method of the present invention for the preparation of a rare earth-cobalt based permanent magnet having an improved coercive force and residual induction as well as excellent squareness of the hysteresis loop comprises the steps of:
(a) sintering a shaped body of an alloy powder composed of from 22 to 28% by weight of at least one rare earth element, from 10 to 30% by weight of iron, from 2 to 10% by weight of copper and from 0.1 to 5% by weight of at least one additive element selected from the group consisting of zirconium, titanium, manganese, tantalum, hafnium, chromium, silicon, tungsten and vanadium, the balance being cobalt, into a sintered body;
(b) subjecting the sintered body to a primary aging treatment by heating at a temperature in the range from 600° to 850° C. followed by a first continuous cooling of the sintered body down to a temperature in the range from 300° to 400° C. at a cooling velocity in the range from 0.5° to 3.0° C./minute; and
(c) subjecting the sintered body after the step (b) to a secondary aging treatment by heating at a temperature in the range from 700° to 900° C. followed by a second continuous cooling of the sintered body down to a temperature in the range from 300° to 500° C. at a cooling velocity in the range from 0.1° to 5.0° C./minute.
If necessary, the sintered body after the secondary aging treatment may be subjected further to a tertiary and a quaternary aging treatment, the schedule of heating and cooling in each of these additional aging treatments being approximately the same as in the secondary aging treatment.
According to the above described inventive method, a coercive force of 10 kOe or higher can readily be obtained of the permanent magnet in addition to the excellent squareness of the hysteresis loop needless to say about the good residual induction as a consequence of the low content of copper in the alloy composition.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As is understood from the above given description, the most characteristic feature of the inventive method is obtained by the specific scheme of the heat treatment since the step (a) for the preparation of the sintered body is rather conventional.
In the first place, a rare earth-cobalt based alloy is prepared by melting together the above described component elements in the specified proportion and the alloy is pulverized into a fine powder by a suitable pulverizing machine. The alloy powder is then molded by compression into a shaped body which is subjected to sintering under known conditions into a sintered body. Molding of the alloy powder filling a mold is usually performed in a magnetic field of at least 5000 Oe or, preferably, at least 7000 Oe by compression under a suitable pressure of, for example, 1000 kg/cm 2 . The shaped body of the alloy powder is then sintered in an atmosphere of an inert gas or vacuum at a temperature in the range from about 1150° to 1250° C. for at least 1 hour.
Heat treatment or aging of the sintered body is undertaken conventionally in any of the prior art methods but the aging treatment in the inventive method is performed in two or more steps or performed at least twice. The first step of the aging treatment is performed by heating the sintered body at a temperature in the range from 600° to 850° C. followed by a first continuous cooling of the sintered body from the above mentioned temperature down to a temperature in the range from 300° to 400° C. at a cooling velocity in the range from 0.5° C. to 3.0° C./minute or, preferably, from 1.0 to 2.0° C./minute. On the other hand, the secondary aging treatment is performed by heating the sintered body after the primary aging treatment above at a temperature in the range from 700° to 900° C. followed by a second continuous cooling of the sintered body from the above mentioned temperature down to a temperature in the range from 300° to 500° C. at a cooling velocity in the range from 0.1° to 5.0° C./minute or, preferably, from 0.1° to 1.0° C./minute. It is preferable that the starting temperature in the second cooling is in the range between the same temperature as the starting temperature in the first cooling and a temperature higher by 150° C. than the starting temperature is in the first cooling.
It is noted that the continuous cooling of the sintered body in each of the primary and secondary aging treatments may be started immediately when the temperature of the sintered body has reached the specified starting temperature in the respective steps without keeping the sintered body at the temperature any longer. It is optional that the secondary aging treatment may directly succeed the primary aging treatment without any interpose. The rate of temperature increase from the lowermost temperature in the first cooling up to the starting temperature of the second continuous cooling is not particularly limitative but should preferably be not larger than 20° C./minute.
As mentioned before, the sintered body after the above described primary and secondary aging treatments may be subjected further to a tertiary and a quaternary aging treatment, if necessary. Such an additional aging treatment is effective in improving the uniformity of the coercive force of the magnets after the secondary aging treatment from piece to piece or in increasing the coercive force of the magnet. The schedule of heating and cooling in these tertiary and quaternary aging treatments may be approximately the same as in the secondary aging treatment. That is, the sintered body after the secondary aging treatment is again heated at a temperature in the range from 700° to 900° C. and, without necessity of keeping it any longer at this temperature, continuously cooled down to a temperature in the range from 300° to 500° C. at a cooling velocity in the range from 0.1° to 5.0° C./minute.
Following is a description of the significance of the limitations in the weight proportion of the individual component elements in the alloy powder from which the rare earth-cobalt based permanent magnet is prepared.
The rare earth element, which is typically samarium or cerium, is taken in an amount from 22 to 28% by weight of the alloy composition. When the amount of the rare earth element is outside the above range, the coercive force of the resultant permanent magnet rapidly decreases with the increase or decrease of the amount of the rare earth element although the optimum amount thereof is largely dependent on the formulation of the other transition elements. The content of iron is limited in the range from 10 to 30% by weight because the permanent magnet prepared from an alloy containing 10% by weight or less of iron has a decreased saturation magnetization while a content of iron larger than 30% by weight results in a decreased coercive force of the magnet in addition to the decrease in the density of the sintered body. Further, the content of copper is limited in the range from 2 to 10% by weight because no sufficiently high coercive force of the magnet can be obtained with a content of copper smaller than 2% by weight while the saturation magnetization is decreased with a content of copper larger than 10% by weight. The amount of the auxiliary additive elements, i.e. zirconium, titanium, manganese, tantalum, hafnium, chromium, silicon, tungsten and vanadium, should be in the range from 0.1 to 5.0% by weight because the coercive force of the magnet cannot be significantly improved by the addition of these elements in an amount smaller than 0.1 % by weight while an excessively large amount of these elements over 5.0% by weight is undesirable due to the decrease in the saturation magnetization.
Followng are the examples to illustrate the method of the present invention in further detail.
EXAMPLE 1
A mixture composed of 24.1% by weight of samarium metal, 53.4% by weight of cobalt, 13.9% by weight of iron, 6.3% by weight of copper and 2.3% by weight of zirconium was melted in a high-frequency induction furnace under an atmosphere of argon to form an alloy and the ingot of the alloy was crushed in a jaw crusher and then in a Brown mill followed by pulverization in a jet mill into a fine powder having an average particle diameter of 3 to 5 μm. A mold was filled with this powder of the magnetic alloy in a magnetic field of 10 to 20 kOe to align the particles and the powder was shaped by compression under a pressure of about 1000 kg/cm 2 . Thus shaped body of the magnet alloy was then subjected to sintering at 1190° C. for 1 hour followed by quenching to give a sintered body which was further subjected to the heat treatment according to the schemes given below.
Scheme I: heating at 800° C. for 20 hours followed by quenching
Scheme II; heating at 800° C. and then cooling at a constant velocity of 0.5° C./minute from 800° C. to 400° C. followed by quenching
Scheme III: a first cooling at a cooling velocity of 1° C./minute from 750° C. to 400° C. followed by quenching and then a second cooling at a cooling velocity of 0.5° C./minute from 800° C. to 400° C. followed by quenching.
Meanwhile, the cooling-down in the Scheme II or in the first and second steps of the Scheme III was started immediately when the temperature of the sintered body had reached the starting temperature of 800° C. or 750° C. without keeping it at the temperature.
Similarly, two similar magnet alloys but with somewhat modified formulation were prepared and processed into permanent magnets in the same manner as described above and the magnetic properties of these permanent magnets were determined to give the results shown in Table 1 below. The magnetic properties determined were the residual induction B r in kG, coercive force i H c in kOe and maximum energy product (BH) max in MGOe and the value of the so-called squareness ratio (BH) max /(Br/2) 2 was calculated as a measure of the squareness of the magnetic hysteresis loop.
TABLE 1__________________________________________________________________________ Magnetic properties No.Magnet Composition, % by weight SmCoFeCuZr treatmentof heatScheme kGB.sub.r' kOe.sub.i H.sub.c, MGOe(BH).sub.max' ##STR1##__________________________________________________________________________1 24.1 53.4 13.9 6.3 2.3 I 10.9 23.4 22.5 0.762 II 10.9 9.6 23.2 0.783 III 10.9 18.0 28.1 0.954 25.3 54.3 14.1 4.0 2.3 I 11.4 1.2 6.5 0.205 II 11.4 7.6 24.8 0.766 III 11.4 14.5 31.2 0.967 24.9 56.4 14.0 2.4 2.3 I 12.3 0.2 0.8 0.028 II 12.3 3.3 21.2 0.569 III 12.3 8.7 34.5 0.91__________________________________________________________________________
EXAMPLE 2
A magnet alloy of the same composition as used in the preparation of the magnet No. 4 to No. 6 in Example 1 was processed into sintered bodies in the same manner as in Example 1 and each of the sintered bodies were subjected to the heat treatment in two steps with the starting temperature and final temperature as well as the cooling velocity in each of the first and second steps as shown in Table 2 below. Table 2 also includes the results of the measurements of the magnetic properties of the thus prepared permanent magnets. In some of the preparations, only the first step of the heat treatment was undertaken with omission of the second step for comparative purpose.
TABLE 2__________________________________________________________________________Temperature (°C.) and coolingvelocity in thefirst step second step Magnetic properties No.Magnet From To ##STR2## From To ##STR3## kGB.sub.r' kOe.sub.i H.sub.c, MGOe(BH).sub.max, ##STR4##__________________________________________________________________________10 850 400 1.0 800 300 0.5 11.4 15.6 28.5 0.8811 800 400 1.0 800 300 0.5 11.4 15.4 30.8 0.9512 750 400 1.0 800 300 0.5 11.4 14.5 31.2 0.9613 700 400 1.0 800 300 0.5 11.4 10.3 31.3 0.9614 650 400 1.0 800 300 0.5 11.4 7.6 31.0 0.9515 600 400 1.0 800 300 0.5 11.4 6.4 29.5 0.9116 750 400 1.0 900 300 0.5 11.4 9.7 28.7 0.8817 750 400 1.0 850 300 0.5 11.4 18.1 31.0 0.9518 750 400 1.0 800 300 0.5 11.4 14.5 31.2 0.9619 750 400 1.0 750 300 0.5 11.4 7.3 30.4 0.9420 750 400 1.0 700 300 0.5 11.4 6.2 29.2 0.9021* 800 400 0.1 11.4 10.5 24.6 0.7622* 800 400 0.3 11.4 9.7 25.2 0.7823* 800 400 0.5 11.4 7.6 24.8 0.7624* 800 400 1.0 11.4 2.2 16.8 0.5225 750 400 1.0 800 300 0.1 11.4 18.8 30.7 0.9426 750 400 1.0 800 300 0.3 11.4 17.3 31.0 0.9527 750 400 1.0 800 300 0.5 11.4 14.5 31.2 0.9628 750 400 1.0 800 300 1.0 11.4 9.2 30.8 0.9529* 750 400 1.0 800 300 6.0 11.4 2.6 18.4 0.57__________________________________________________________________________ *Comparative example
EXAMPLE 3
The same magnet alloy is used in Example 2 was processed into sintered bodies in the same manner as in Example 1 by sintering the shaped body of the powder at 1180° C., 1185° C., 1190° C., 1195° C. or 1200° C. each for 1 hour followed by quenching. These sintered bodies were subjected to the primary to quaternary aging treatments each in a schedule indicated in Table 3 below. Table 3 also includes the results of the measurements of these permanent magnets for the coercive force i H c and the squareness ratio (BH) max /(Br/2) 2 after each of the secondary to quaternary aging treatments. In Table 3, the Experiment Nos. 30 to 34 correspond to the above mentioned different sintering temperatures of 1180°, 1185°, 1190°, 1195° and 1200° C., respectively.
TABLE 3______________________________________ Aging treatment Pri- Secon- Quater- mary dary Tertiary maryCooling from 700 800 800 800(°C.) to 400 300 300 300Exp. Cooling Velocity,No. °C./minute 1.0 0.5 0.5 2.0______________________________________30 iHc* 1,800 11,300 12,000 12,000squareness ratio -- 0.93 0.94 0.9531 iHc* 1.650 11,000 11,900 12,100squareness ratio -- 0.95 0.95 0.9632 iHc* 1,500 10,300 11,500 12,000squareness ratio -- 0.94 0.95 0.9633 iHc* 1,500 9,700 11,000 11,600squareness ratio -- 0.92 0.93 0.9434 iHc* 1,300 8,800 10,300 10,800squareness ratio -- 0.89 0.91 0.93______________________________________ *in oersted
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The permanet magnet composed of a rare earth element, e.g. samarium, and cobalt together with iron, copper and some other additive elements and prepared according to the inventive method has a high coercive force and excellent squareness of the magnetic hysteresis loop despite the relatively low content of copper which has been considered to be indispensable for obtaining a high coercive force. The characteristic feature of the inventive method consists in the aging treatment of the sintered body of the alloy powder of a specified composition undertaken in two or more steps, each being carried out by continuously cooling the sintered body within a specified temperature range at a specified cooling velocity.
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CROSS REFERENCE TO RELATED APPLICATIONS
NOT APPLICABLE
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
NOT APPLICABLE
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX
NOT APPLICABLE
BACKGROUND OF THE INVENTION
The following disclosure relates generally to machines and apparatuses having axial piston arrangements and, more particularly, to apparatuses and methods for converting reciprocating linear motion of one or more pistons into rotary motion of an associated shaft oriented in parallel to the piston motion.
Various apparatuses are known that convert movement of a working fluid within a changeable cylinder volume into rotary motion of an input/output shaft. Conventional internal combustion engines, compressors, and pumps are just a few of such apparatuses. In conventional arrangements, the pistons are connected via connecting rods to a crankshaft that rotates on an axis oriented perpendicular to the direction of travel of the piston.
The theoretical advantages of the axial piston arrangement have been well understood for many years, but no prior effort has succeeded in the marketplace. The primary difficulty in implementing an axial piston engine is in the means provided for preventing rotation of the motion converter, or as commonly referred to, the “wobble plate.”
BRIEF SUMMARY OF THE INVENTION
It is an object of the invention to reduce friction losses in internal combustion engines and the like.
Another object of the invention to provide for variable compression ratio in internal combustion engines.
A further object of the invention is to provide a piston motion that is harmonic in nature and can be readily balanced and thereby reduce vibration.
It is an additional object of the invention to provide an improved means for preventing the rotation of the motion converter in an axial piston machine.
Another object of the invention is to provide a means for preventing the rotation of the connecting rods in an axial piston machine.
Yet another object of the invention is to provide for a one-piece or rigidly attached piston and connecting rod in an axial piston machine.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of an axial piston apparatus configured in accordance with an embodiment of the invention.
FIG. 2 is an isometric view of the axial piston apparatus of FIG. 1 with various portions removed for purposes of clarity.
FIG. 3 illustrates a side elevation view and a top plan view of the axial piston apparatus of FIG. 2 .
FIG. 4 is an exploded isometric view of the motion converter/Z-crank/reaction control shaft assembly of FIGS. 1–3 configured in accordance with embodiments of the invention.
FIG. 5 is an isometric view of the Z-crank of FIG. 4 configured in accordance with an embodiment of the invention.
FIG. 6 is an exploded isometric view of the motion converter and the Z-crank of FIGS. 4 and 5 configured in accordance with embodiments of the invention.
FIG. 7 is a partially exploded isometric view of the reaction control shaft of FIGS. 1–4 configured in accordance with an embodiment of the invention.
FIG. 8 is a partially cutaway isometric view of an axial piston apparatus having an anti-rotation gear train configured in accordance with another embodiment of the invention.
FIG. 9 is a side elevational view of the axial piston apparatus of FIG. 8 with portions removed for purposes of clarity in accordance with an embodiment of the invention.
FIG. 10 is an isometric view of the axial piston apparatus of FIG. 9 configured in accordance with an embodiment of the invention.
FIG. 11 is a top view of the axial piston apparatus of FIG. 9 configured in accordance with an embodiment of the invention.
FIG. 12 is an exploded isometric view of a piston/connecting rod assembly configured in accordance with an embodiment of the invention.
FIG. 13 is an isometric view of an axial piston apparatus configured in accordance with yet another embodiment of the invention.
FIG. 14 is an exploded isometric view of a one-piece piston/connecting rod assembly configured in accordance with another embodiment of the invention.
FIG. 15 is an isometric view of an axial piston apparatus having opposed cylinders facing outwardly from each other in a back-to-back arrangement in accordance with an embodiment of the invention.
FIG. 16 illustrates a side elevation view and a top view of the axial piston apparatus of FIG. 15 in accordance with an embodiment of the invention.
FIG. 17 is an isometric view of an axial piston apparatus having opposed pistons facing toward each other in pairs sharing a common cylinder in accordance with an embodiment of the invention.
FIG. 18 illustrates a side elevation view and a top view of the axial piston apparatus of FIG. 17 .
DETAILED DESCRIPTION
The following disclosure is directed to apparatuses and methods for converting reciprocal linear motion of one or more pistons into rotary motion of an output power shaft whose rotational axis is parallel to ther motions of the pistons or, conversely, for converting rotary motion of a similarly configured input shaft into reciprocal linear motion of one or more pistons. Various embodiments of the invention can be applied to internal combustion engines, external combustion engines, air compressors, air motors, liquid fluid pumps, and the like where movement of a working fluid within a volume-changing cylinder results from/in rotary motion of an input/output shaft. In contrast to conventional engines, compressors, and pumps where the crankshaft's rotational axis is perpendicular to the motions of the pistons, an axial piston apparatus configured in accordance with embodiments of the present invention can have one or more cylinders aligned in parallel with the rotational axis of the input/output shaft. As described in greater detail below, such a configuration can further include the capability to dynamically vary the compression ratio in the cylinders to alter the performance characteristics of the apparatus.
Certain embodiments of the apparatuses and methods described herein are described in the context of fluid pumps, fluid compressors, and internal combustion engines of both two- and four-stroke cycle designs. Accordingly, in these embodiments, the invention can include one or more features often associated with internal combustion engines, fluid pumps, or compressors such as fuel delivery systems, ignition systems, and/or various other engine/pump control functions. Because the basic structures and functions often associated with internal combustion engines, fluid pumps, fluid compressors and the like are known to those of ordinary skill in the relevant art, they have not been shown or described in detail here to avoid unnecessarily obscuring the described embodiments of the invention.
Certain specific details are set forth in the following description and in FIGS. 1–18 provide a thorough understanding of various embodiments of the invention. Those of ordinary skill in the relevant art will understand, however, that the invention may have additional embodiments that may be practiced without several of the details described below. In addition, some well-known structures and systems often associated with engines, pumps, and compressors have not been shown or described in detail here to avoid unnecessarily obscuring the description of the various embodiments of the invention.
In the drawings, identical reference numbers identify identical or at least generally similar elements. To facilitate the discussion of any particular element, the most significant digit or digits in any reference number refers to the figure in which that element is first introduced. For example, element 130 is first introduced and discussed in reference to FIG. 1 . In addition, any dimensions, angles and other specifications shown in the figures are merely illustrative of particular embodiments of the invention. Accordingly, other embodiments of the invention can have other dimensions, angles and specifications without departing from the spirit or scope of the present disclosure.
FIG. 1 is an isometric view of an axial piston apparatus 100 configured in accordance with an embodiment of the invention. For ease of reference, the phrase “axial piston apparatus” will be understood to include engines, pumps, compressors, etc. having the piston arrangement more or less as depicted, unless specifically identified otherwise. In one aspect of this embodiment, the apparatus 100 includes one or more cylinders 110 aligned in parallel with a rotational axis 131 of a Z-crank 130 . Although the illustrated embodiment depicts three cylinders 110 , in other embodiments, the engine 100 can include more or fewer cylinders 110 without departing from the spirit or scope of the present disclosure. As discussed in greater detail below, in those embodiments in which a four-stroke combustion process is utilized, it may be advantageous for the apparatus 100 to include an odd number of cylinders 110 . In contrast, those embodiments of the apparatus 100 utilizing a two-stroke combustion process may include an odd or even number of cylinders 110 .
In another aspect of this embodiment, pistons 112 reciprocate back and forth within the cylinders 110 parallel to the Z-crank rotational axis 131 . The pistons 112 are connected via connecting rods 114 to a “wobble-plate” or motion converter 120 . As described in greater detail below, the motion converter 120 is rotatably attached to the Z-crank 130 about a nutation axis 133 such that the Z-crank 130 is free to rotate with respect to the motion converter 120 about the nutation axis 133 . Accordingly, reciprocating motion of the pistons 112 in the cylinders 110 causes the motion converter 120 to nutate or wobble (but not rotate) relative to the Z-crank rotational axis 131 .
In a further aspect of this embodiment, the apparatus 100 also includes a reaction control shaft 150 slidably engaging the motion converter 130 . As explained in greater detail below, the reaction control shaft 150 restricts rotational movement of the motion converter 130 while allowing the motion converter 130 to nutate relative to the Z-crank rotational axis 131 . The reaction control shaft 150 is configured to accommodate this nutation by rotating about an axis 151 as the Z-crank 130 rotates about its rotational axis 131 . A gear train 160 controls motion of the reaction control shaft 150 relative to the Z-crank 130 .
In operation, reciprocating motion of the pistons 112 within the cylinders 110 causes the motion converter 120 to nutate relative to the Z-crank rotational axis 131 . Although the motion converter 120 nutates, it does not rotate a significant amount. Nutation of the motion converter 120 causes the Z-crank 130 to rotate relative to the motion converter 120 about the nutation axis 133 . Such motion also causes the Z-crank 130 to rotate about the Z-crank axis 131 . While the Z-crank 130 rotates, the reaction control shaft 150 also rotates about its axis 151 (e.g., at twice the Z-crank rotational speed) to accommodate the nutational movement of the motion converter 120 while restricting rotational movement of the motion converter 120 .
Accordingly, in an internal combustion engine embodiment, combustion of fuel gases in the cylinders 110 can impart linear motion to the pistons 112 which in turn causes the motion converter 120 to wobble or nutate relative to the Z-crank rotational axis 131 providing rotational shaft-power at the Z-crank 130 . This shaft-power can be utilized for any one of many applications including propelling air, land, and sea vehicles. Alternatively, when used as a pump or air compressor, shaft-power can be applied to the Z-crank 130 causing it to rotate about the Z-crank rotational axis 131 and thereby nutate the motion converter 120 . Nutation of the motion converter 120 in turn causes axial motion of the pistons 112 in the cylinders 110 . Such motion can be used to pump water, air or another fluid to or from a reservoir or source (not shown) for many applications.
In yet another aspect of this invention, the axial arrangement of the cylinders 110 relative to the Z-crank rotational axis 131 can advantageously facilitate compression ratio changes within the cylinders 110 . For example, in one embodiment the apparatus 100 can include a support plate 140 that provides rotational support to the Z-crank 130 and the reaction control shaft 150 . In the illustrated embodiment, the support plate 140 can be axially movable relative to the cylinders 110 back and forth parallel to the Z-crank rotational axis 131 . Accordingly, as the support plate 140 moves toward the cylinders 110 , the clearance between the top of the pistons 112 and the top of the combustion chamber within the cylinders 110 is reduced. As a result, such movement of the support plate 140 causes the compression ratio within the cylinders 110 to increase. Similarly, movement of the support plate 140 away from the cylinders 110 causes the compression ratio within the cylinders 110 to decrease. As will be appreciated by those of ordinary skill in the relevant art, controlling the compression ratio within the cylinders 110 in the foregoing manner can advantageously be used to alter or optimize various performance aspects of the axial piston apparatus 100 .
In one aspect of this embodiment, the axial piston apparatus 100 can include an actuator 142 operably connected to the support plate 140 , and an engine control unit 144 (“ECU” 144 ) that provides control inputs to the actuator 142 . In one embodiment, the actuator 142 can include a hydraulic actuator configured to move the support plate 140 back and forth relative to the cylinders 110 . In other embodiments, other types of mechanical, hydraulic, pneumatic and other types of actuators can be used to move the support plate 140 in response to inputs from the ECU 144 . The ECU 144 of the illustrated embodiment can include one or more facilities for receiving engine operating information and outputting control signals to the actuator 142 . For example, in one embodiment, the ECU can include a processor and a controller. In other embodiments, the ECU can include other functionalities. In yet another embodiment, the ECU 144 may be at least substantially similar to ECUs for controlling conventional internal combustion engines. In this embodiment, however, the ECU 144 , in addition to controlling engine functions such as fuel intake, ignition timing, and/or valve timing, can provide additional output signals to control the actuator 142 and move the support plate 140 in response to one or more of the engine operating parameters. In a further aspect of this embodiment, one or more engine sensors 146 can provide engine operating parameter input to the ECU 144 . Such engine sensors can include, for example, airflow rate, combustion and/or exhaust temperatures, throttle position, vehicle speed, etc.
In a further aspect of this embodiment, a variable compression axial piston engine in accordance with the present invention can be utilized to optimize engine performance to suit different operating conditions. For example, when the axial piston engine is operated at idle speeds, the compression in the combustion chambers can be reduced to enhance fuel efficiency. Alternatively, at higher RPMs, the compression within the combustion chambers can be increased. In other embodiments, the variable compression aspects of the present invention can be utilized in other ways to increase efficiency or performance.
FIG. 2 is an isometric view of the axial piston apparatus 100 of FIG. 1 with the cylinders and housing removed for purposes of clarity. In one aspect of this embodiment, the connecting rods 114 are double-articulating connecting rods that can accommodate rotational movement about two axes at each end. For example, an upper wrist pin 218 joining the “small end” of the connecting rod 114 to the piston 112 is configured to gimbal or rotate in at least two axes with respect to the connecting rod 114 . Similarly, a lower wrist pin 216 joining the “big-end” of the connecting rod 114 to the motion converter 120 is also able to gimbal or rotate about at least two axes with respect to the motion converter 120 . Details of the connecting rod attachments will be described more fully below, as will an alternate embodiment of the invention wherein the connecting rods 114 are at least substantially fixed relative to the pistons 112 . In this alternate embodiment, the pistons 112 are at least partially spherically shaped, as shown in crossisection 1312 to accommodate minor tilting motions of the connecting rods 114 .
The gear train 160 introduced above with reference to FIG. 1 is shown to good advantage in FIG. 2 . In another aspect of this embodiment, the gear train 160 includes a Z-crank gear 262 rotatably coupled to a reaction control shaft gear 266 via an idler gear 264 . Both the idler gear 264 and the reaction control shaft gear 266 can have one-half as many teeth as the Z-crank gear 262 . Accordingly, this gear arrangement will cause the reaction control shaft 150 to rotate at twice the speed of the Z-crank 130 . As explained in greater detail below, in one aspect of this embodiment, this speed is necessary so that an offset portion 351 of the reaction control shaft 150 that guides the motion converter 120 will complete two orbits about its rotational axis as the Z-crank 130 completes one full rotation and the motion converter 120 completes one full nutation. In other embodiments, other gear arrangements can be used to provide the requisite timing between the Z-crank 130 and the reaction control shaft 150 without departing from the spirit or scope of the present invention.
FIG. 3 includes side elevation and top plan views of the axial piston apparatus 100 of FIG. 2 . FIG. 3 illustrates how fore and aft motion of the support plate 140 changes the axial position of the pistons 112 relative to the cylinders 110 (not shown) thereby changing the compression ratio in the cylinders 110 . In one aspect of this embodiment, the axial piston apparatus 100 includes a reaction control bearing 352 slidably and rotatably positioned on an offset bearing surface 351 of the reaction control shaft 150 . As described in greater detail below, the reaction control bearing 352 allows the motion converter 120 to nutate about the Z-crank rotational axis 131 while restricting rotational motion of the motion converter 120 . The reaction control bearing 352 further allows the motion converter 120 to travel back and forth along the offset bearing surface 351 as the motion converter 120 nutates. The reaction control bearing 352 can be configured to rotate relative to the offset bearing surface 351 to accommodate rotation of the reaction control shaft 150 about its rotational axis 151 .
FIG. 4 is an exploded isometric view of the motion converter/Z-crank/reaction control shaft assembly of FIGS. 1–3 configured in accordance with embodiments of the invention. In one aspect of this embodiment, the Z-crank assembly 130 includes a motion connection throw or bearing surface 432 configured to receive the motion converter 120 . As explained above, the bearing surface 432 is aligned with the nutation axes 133 . The Z-crank assembly 130 can further include fore and aft bearing surfaces 434 and 435 for rotationally supporting the Z-crank 130 relative to the housing of the axial piston apparatus 100 ( FIG. 1 ). The fore and aft bearing surfaces 434 and 435 can be suitably supported in bearings to permit free rotation of the Z-crank 130 about the Z-crank rotational axis 131 . As illustrated, the Z-crank rotational axis 131 intersects the nutational axis 133 at a location that is at least approximately centered on the motion converter bearing surface 432 . Although the forward bearing surface 434 appears relatively short in FIG. 4 , in other embodiments, the Z-crank 130 can extend further forward from the forward bearing surface 434 and provide rotational surfaces for actuating other mechanisms related to the axial piston apparatus 100 . For example, as explained in greater detail below, in one embodiment the Z-crank 130 can be extended forward from the forward bearing surface 434 to provide camshaft lobes for actuating poppet-valves or other fluid control valves associated with combustion or pump processes.
In another aspect of this embodiment, the motion converter 120 has a centerbore 422 including one or more bearings (e.g., needle bearings) configured to rotatably receive the Z-crank bearing surface 432 . The motion converter 120 can further include a reaction control bearing bore 424 radially offset from the centerbore 422 and configured to rotatably receive the reaction control bearing 352 . The reaction control bearing 352 can similarly include a control shaft bore 454 configured to slidably and rotatably receive the offset bearing surface 351 of the reaction control shaft 150 . The reaction control shaft gear 266 is fixed to one end of the reaction control shaft 150 and is configured to be operably engaged with the Z-crank gear 262 fixed on the Z-crank 130 proximate to the aft bearing surface 435 .
FIG. 5 is an isometric view of the Z-crank 130 configured in accordance with an embodiment of the invention. In one aspect of this embodiment, the Z-crank 130 can include a forward splined portion 531 positioned proximate to the forward bearing surface 434 , and an aft splined portion 532 positioned proximate to the aft bearing surface 435 . The splined portions illustrated in FIG. 5 can be utilized to accommodate axial movement of the Z-crank 130 relative to other parts that engage with the splined portions. For example, referring to FIG. 3 above, axial movement of the support plate 140 causes the Z-crank 130 to move fore and aft along its rotational axis 131 . If the Z-crank aft splines 532 are engaged with, for example, a rotational member or other coupling that is axially (but not rotationally) fixed relative to the Z-crank 130 , then the aft splined portion 532 permits the Z-crank to move fore and aft relative to such a fixed coupling. Similarly, if the forward splined portion 531 is engaged with another rotational member that is also axially fixed relative to the Z-crank 130 , then the forward splined portion 531 accommodates the relative axial movement between the Z-crank 130 and the forward member. Thus, as the Z-crank/motion converter assembly moves fore and aft along the rotational axis 131 of the Z-crank 130 , the splined portions on the forward and aft end of the Z-crank 130 can accommodate the relative axial motion between the Z-crank and any mating features. In other embodiments, other features can be utilized to accommodate the relative motion of the Z-crank/motion converter assembly as the Z-crank moves fore and aft to change the compression ratio in the cylinders 110 ( FIG. 1 ).
In yet another aspect of this embodiment, the Z-crank 130 can include a counter-weight 534 laterally offset from the Z-crank rotational axis 131 . If required or desirable, the counter-weight 534 can be used to dynamically balance the motion converter/Z-crank assembly.
FIG. 6 illustrates exploded isometric views of the motion converter 120 and the Z-crank 130 configured in accordance with embodiments of the invention. The embodiments illustrated in FIG. 6 are merely representative and, accordingly, and are not intended to limit the present invention to the configurations shown. Accordingly, in other embodiments, other components can be utilized to construct and practice the motion converter 120 and the Z-crank 130 of the present invention. In the illustrated embodiment, the Z-crank 130 can include an upper portion 634 mated to a lower portion 636 with a taper pin 637 . Prior to mating, the upper Z-crank portion 634 can receive a thrust bearing 638 and can be inserted through the motion converter bore 422 . After the upper Z-crank portion 634 is inserted through the motion converter bore 422 , it can receive another thrust bearing 638 and be inserted into the lower Z-crank portion 636 , thereby rotatably capturing the motion converter 120 on the Z-crank 130 .
In another aspect of this embodiment, the motion converter 120 can include needle bearings 628 received in the motion converter bore 422 . The needle bearings 628 facilitate rotational motion of the Z-crank 130 relative to the motion converter 120 . In other embodiments, other bearings in other configurations can be used to provide rotational freedom of the Z-crank 130 relative to the motion converter 120 .
FIG. 7 is a partially exploded isometric view of the reaction control shaft 150 shown in FIGS. 1–4 above. In one aspect of this embodiment as mentioned above, the reaction control shaft gear 266 can be fixedly attached to a lower end of the reaction control shaft 150 to control the rotational motion of the reaction control shaft 150 about its rotational axis 151 . As shown to good effect in FIG. 7 , the offset bearing surface 351 is cylindrical in cross-section and has a centerline axis 751 that is offset relative to the rotational axis 151 of the reaction control shaft 150 . In one aspect of this embodiment, this offset is necessary to facilitate the nutational motion of the motion converter 120 . In another aspect of this embodiment, the reaction control shaft 150 can include counter-weights 756 which can be machined or otherwise conformed to rotationally balance the reaction control shaft 150 about its rotational axis 151 .
In a further aspect of this embodiment, the reaction control bearing 454 includes a ball bearing 752 and a retaining ring 754 . The ball bearing 752 is received on the reaction control bearing 352 at an angle relative to the reaction control bearing bore 454 . In a further aspect of this embodiment, the angle of the ball bearing 752 accommodates the nutational movement of the motion converter 120 relative to the reaction control shaft 150 as the Z-crank 130 rotates. In addition, the ball bearing 752 allows the reaction control bearing 352 to rotate relative to the reaction control bearing bore 424 ( FIG. 4 ) of the motion converter 120 . This relationship between the ball bearing 752 , the reaction control shaft 150 , and the motion converter 120 can be seen with reference to FIG. 3 . The retaining ring 754 can be threadably installed onto the reaction control bearing 352 to retain the ball bearing 752 .
Prior to assembly of the reaction control shaft 150 (for example, prior to installing the first counterweight 756 ), the bearing surface 351 of the reaction control shaft 150 is inserted through the reaction control bearing bore 454 of the reaction control bearing 352 . The first counterweight 755 can then be installed on the reaction control shaft 150 .
The foregoing discussion describes one embodiment of the present invention for restricting rotational movement of the motion converter 120 as it nutates relative to the Z-crank rotational axis 131 ( FIGS. 1–3 ). In other embodiments, other apparatuses and methods can be utilized to restrict this rotational movement without departing from the spirit or scope of the present invention. Specifically, other apparatuses and methods can be utilized to restrict this rotational movement while still enabling the variable compression features of the present invention. One such embodiment is described in greater detail below with reference to FIG. 8 and on.
FIG. 8 is a partially cutaway isometric view of an axial piston apparatus 800 having an anti-rotation gear train 860 configured in accordance with another embodiment of the invention. Although the axial piston apparatus 800 of FIG. 8 includes six pistons 812 and associated hardware, this number is in no way limiting and, in other embodiments, the axial piston apparatus 800 can include more or fewer pistons 812 . Similarly, although the illustrated embodiment may depict a two-stroke diesel engine configuration, in other embodiments, the anti-rotation gear train 860 and associated features can be utilized with other axial piston apparatuses (e.g., 4-stroke engine or pump apparatuses) configured in accordance with the present disclosure. In the illustrated embodiment, a forward splined portion 831 of a Z-crank 830 protrudes beyond an engine block or housing 801 . As discussed above, the forward splined portion 831 can be utilized to drive a camshaft for, among other things, actuating inlet poppet valves for providing fuel mixture to combustion chambers in the cylinders 810 .
FIG. 9 is a side elevation view of the axial piston apparatus 800 of FIG. 8 with the housing 801 removed to better illustrate aspects of the anti-rotation gear train 860 configured in accordance with an embodiment of the invention. As shown in FIG. 9 , the anti-rotation gear train 860 replaces the reaction control shaft 150 described above and serves the same function, namely, to restrict rotational movement of a motion converter 920 .
In one aspect of this embodiment, the anti-rotation gear train 860 (the “gear train 860 ”) includes a fixed gear 862 , a first planetary gear 864 , a second planetary gear 866 , and a motion converter gear 868 . The fixed gear 862 can be fixedly mounted to a lower portion of the Z-crank 830 and meshed with the first planetary gear 864 . In one embodiment, the fixed gear 862 and the planetary gear 864 can be straight gears. In other embodiments, these gears can have other configurations. In another aspect of this embodiment, the first planetary gear 864 can be fixedly mounted on a common shaft with the second planetary gear 866 . Accordingly, the first and second planetary gears 864 and 866 are fixed relative to each other and rotate about a common axis 835 . In a further aspect of this embodiment, the second planetary gear 866 can be beveled or tapered to mesh with the correspondingly tapered motion converter gear 868 . The motion converter gear 868 can be rotatably mounted (e.g., with needle or roller bearings) to a bearing surface 832 of the Z-crank 830 . Further, the motion converter gear 868 can be fixedly attached to the motion converter 920 .
An example of the operation of the gear train 860 will now be explained in accordance with an embodiment of the invention in which a combustion force F drives the pistons 812 to provide shaft-power output from the Z-crank 830 . In this embodiment, combustion gases move the pistons 812 causing the motion converter 920 to wobble or nutate relative to the Z-crank axis 931 . As the motion converter 920 nutates, it causes the Z-crank 830 to rotate about its rotational axis 931 . Simultaneously, however, the gear train 860 prevents the motion converter 920 from rotating relative to the nutational axis 833 . Rotation of the motion converter 920 is prevented by the motion converter gear 868 which is fixed relative to the motion converter 920 and engaged with the second planetary gear 866 . The second planetary gear 866 is fixed relative to the first planetary gear 864 which in turn meshes with the fixed gear 862 . In a further aspect of this embodiment, the ratio of the fixed gear 862 to the first planetary gear 864 should be equal to the ratio of the motion converter gear 868 to the second planetary gear 866 . When this ratio is met, the gear train 860 as illustrated in FIG. 9 can at least substantially prevent significant rotation of the motion converter 920 .
If the motion converter 920 is allowed to rotate freely about the nutation axis 833 as the Z-crank 830 rotates, then the motion converter 920 cannot convert linear motion of the pistons 812 into torque at the Z-crank 830 nor, conversely, can the motion converter 920 convert torque from the Z-crank 830 into linear motion of the pistons 812 . Accordingly, in an ideal situation, the motion converter 920 will move in a purely nutational motion without any substantial rotation.
FIGS. 10 and 11 are isometric and top views, respectively, illustrating further aspects of the axial piston apparatus 800 discussed above with reference to FIG. 9 .
FIG. 12 is an exploded isometric view of a piston/connecting rod assembly configured in accordance with an embodiment of the invention. In one aspect of this embodiment, the piston/connecting rod assembly shown in FIG. 12 can be at least generally similar to the double-articulating piston/connecting rod assemblies described above with reference to FIG. 2 . For example, the upper wrist pin 218 can be received in an upper trunnion 1201 which pivotally connects the upper end (i.e., the “small end”) of the connecting rod 114 to the piston 112 . Similarly, the lower wrist pin 216 can be received in a lower trunnion 1201 which pivotally connects the lower end (i.e., the “big end”) of the connecting rod 114 to a corresponding motion converter (e.g., the motion converter 120 or 920 described above). To accommodate rotation of the wrist pins about at least two axes, the trunnions 1201 , 1202 can include a spherical surface and opposing trunnion pins. The spherical surface and opposing trunnion pins can be received within an interior portion of mating spherical shell bearings to accommodate rotation about a trunnion pin axis 1211 as well as rotation about a wrist pin axis 1213 . A key or similar feature can be used to register the spherical shell bearings in the corresponding ends of the connecting rod 114 . As will appreciated by those of ordinary skill in the relevant art, other methods and apparatuses can be utilized to pivotally connect the piston 112 to the connecting rod 14 , and the connecting rod 14 to a corresponding motion converter, in accordance with the present disclosure. The embodiment illustrated in FIG. 12 represents only one such method.
FIG. 13 is an isometric view of an axial piston apparatus 1300 that is at least generally similar in structure and function to the axial piston apparatus 100 described above with reference to FIG. 1 through 5 . In one aspect of this embodiment, however, the axial piston apparatus 1300 includes one-piece piston/connecting rod assemblies 1313 . The one-piece piston/connecting rod assemblies 1313 can include a piston portion 1312 and a connecting rod portion 1314 . The piston portion 1312 can have a spherical cross-section to accommodate slight angular motion of the connecting rod portion 1314 relative to the cylinder (not shown) resulting from the nutational movement of the motion converter 120 . Such one-piece piston/connecting rod assemblies 1313 may, in certain embodiments, reduce the overall cost of the axial piston apparatus 1300 relative to other configurations. As shown in FIG. 14 , for example, the one-piece piston/connecting rod assembly 1313 necessarily has a lower part count than a piston assembly having the double-articulated connecting rod 114 .
Various aspects of the axial piston apparatuses described above can be combined to create engine and/or pump configurations in addition to those described above. For example, various dual-Z-crank configurations can be achieved in accordance with the present disclosure. Such dual-Z-crank configurations can include pistons facing towards each other in pairs sharing common cylinders. Alternatively, such configurations can include opposed cylinders facing outwardly relative to each other similar to two axial piston apparatuses positioned back-to-back. Such configurations may be advantageously self-counterbalancing and not require further counterbalancing via weights, etc.
FIG. 15 is an isometric view of an axial piston apparatus 1500 having a first axial piston apparatus 1501 operably coupled to a second axial piston apparatus 1502 in a back-to-back relationship. In one aspect of this embodiment, the combined apparatuses include two Z-cranks which are coupled together and provide shaft-power output via an output gear 1530 . Various mechanical features of the axial piston apparatus 1500 illustrated in FIG. 15 can be at least generally similar in structure and function to their corresponding counterparts of the axial piston apparatus 100 described above. In addition, however, the axial piston apparatus 1500 can include a Z-crank actuator to simultaneously (or independently) move the coupled Z-cranks back and forth relative to each other on their rotational axis. Such movement can vary the compression in one or both sets of cylinders (not shown) to provide the variable compression aspects of the invention described above. When two complete axial piston apparatuses are coupled back-to-back as illustrated in FIG. 15 , the reaction forces of the two motion converters can cancel out. Accordingly, counterbalancing of such apparatuses may not be required when the two opposing Z-cranks are in directly opposing phases relative to each other.
FIG. 16 illustrates a side elevation view and a top view of the axial piston apparatus 1500 of FIG. 15 . As shown in the side elevation view, the opposing Z-cranks 1530 are coupled together as are the corresponding reaction control shafts 1550 . In a further aspect of this embodiment, the opposed motion converters 1520 can be in phase for four-stroke engine applications and at least slightly out of phase for two-stroke engine applications and compressor or pump applications. Varying the phase for two-stroke engine applications and compressor or pump applications may be advantageous, in selected embodiments, to accommodate the intake port or outlet port timing arrangements in the cylinders of such applications. In other embodiments, however, the opposing motion converters 1520 can have other phase timings with respect to each other without departing from the spirit or scope of this disclosure.
FIG. 17 is an isometric view of an axial piston apparatus 1700 having an opposed piston configuration in accordance with yet another embodiment of the invention. In one aspect of this embodiment, opposing pistons 1712 linearly reciprocate in common cylinders (cylinders are not shown in FIG. 17 ). The axial piston apparatus 1700 can have coupled Z-cranks 1730 and coupled reaction control shafts 1750 similar to the axial piston apparatus 1500 shown in FIG. 15 . In the embodiment depicted in FIG. 17 , however, the variable compression features described above can be implement by moving one or both of the opposing Z-cranks toward or away from each other to accordingly change the working volumes in the corresponding cylinders. In a further aspect of this embodiment, the axial piston apparatus 1700 can be configured as a two-stroke engine utilizing exhaust and intake ports instead of poppet-type valves. In this embodiment, one or more exhaust ports can be positioned toward one end of a cylinder and one or more intake ports can be positioned toward the other end. The opposed Z-cranks 1730 may then be configured to operate slightly out of phase so that the exhaust ports on one end are open before the intake ports open on the other end. Such sequential timing may be desirable to maintain the momentum and/or flow direction of the fluid moving into and out of the corresponding cylinder volume. In a further embodiment, such an engine configuration may be supercharged or turbocharged to provide additional advantages depending on the particular application.
FIG. 18 illustrates a side elevation view and a top view of the axial piston apparatus 1700 of FIG. 17 to further illustrate aspects of this embodiment.
The foregoing description of the embodiments of the invention are not intended to be exhaustive or to limit the invention to the precise embodiments disclosed herein. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those of ordinary skill will recognize. For example, although certain functions may be described in the present disclosure in any particular order, and alternate embodiments, these functions can be performed in a different order or, alternatively, these functions may be performed substantially concurrently. In addition, the teachings of the present disclosure can be applied to other systems, not only the representative axial engine, compressor, pump systems described herein. Further, various aspects of the invention described herein can be combined to provide yet other embodiments.
Accordingly, aspects of the invention can be modified, if necessary or desirable, to employ the systems, functions, and concepts of conventional engine, pump and/or compressor apparatuses to provide yet further embodiments of the invention. These and other changes can be made to the invention in light of the above-detailed description. Accordingly, the actual scope of the invention encompasses the disclosed embodiments described above and all equivalent ways of practicing or implementing the invention.
Unless the context clearly requires otherwise, throughout this disclosure the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say, in the sense of “including, but not limited to.” Words using the singular or plural number also include the plural or singular number, respectively. Additionally, the words “herein,” “above,” “below,” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application.
The following examples represent additional embodiments of axial piston apparatuses configured in accordance with the present disclosure.
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This invention relates to internal combustion engines with cylinders arranged parallel to the main shaft and where reciprocating movements of the pistons are converted to rotation by means of a Z-crank mechanism and motion converter, or conversely to systems such as pumps and compressors wherein rotation of the Z-crank and motion converter produces reciprocating motions of the pistons. The motion converter is prevented from rotation by a reaction control shaft or by a gear train. Connecting rods are prevented from rotating about their long axes. Double-ended configurations can be either opposed cylinder or opposed piston, and may include multiple pairs of pistons with each pair in a common cylinder. The Z-crank may be moved axially for the purpose of varying the compression ratio. Variation of the compression ratio is controlled by an engine control unit and is adjusted to optimize engine performance under varying loads and other conditions.
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BACKGROUND OF THE INVENTION
The present invention relates generally to exposure apparatuses and methods, and more particularly to an exposure apparatus and method for projecting and exposing an object, such as a single crystal substrate for a semiconductor wafer, a glass plate for a liquid crystal display (“LCD”).
The fabrication of a device, such as a semiconductor device, an LCD device, and a thin film magnetic head using the lithography technique has employed a projection exposure apparatus that uses a projection optical system to project a circuit pattern formed on a mask or reticle (these terms are used interchangeably in this application) onto a wafer and the like, thereby transferring the circuit pattern.
The projection exposure apparatus has been required to project and expose a circuit pattern on a reticle onto a wafer with higher resolution along with the finer process and higher density of integrated circuits devices. The critical dimension or resolution transferable in the projection exposure apparatus is in proportion to a wavelength of light used for the exposure and in reverse proportion to a numerical aperture (NA) in the projection optical system. Therefore, recent light sources have been in transition from the ultra-high pressure mercury lamp (including g-line (with a wavelength of about 436 nm) and i-line (with a wavelength of about 365 nm)) to a KrF excimer laser with a shorter wavelength (i.e., a wavelength of about 248 nm) to the ArF excimer laser (with a wavelength of about 193 nm), and practical use of the F 2 laser (with a wavelength of about 157 nm) is also being promoted. A further expansion of the exposure area has been also required.
In order to satisfy these requirements, a step-and-repeat exposure apparatus (also referred to as a “stepper”) for entirely projecting and exposing an approximately square exposure area onto a wafer with a reduced exposure area has been replaced mainly with a step-and-scan exposure apparatus (also referred to as a “scanner”) for accurately exposing a wide screen of exposure area through a rectangular slit with relatively and quickly scanning the reticle and the wafer.
In exposure, the scanner uses a surface-position detector in an oblique light projection system to measure a surface position at a certain position on the wafer before the exposure slit area moves to the certain position on the wafer, and correctingly accords the wafer surface with an optimal exposure image-surface position when exposing the certain position, thereby reducing influence of the flatness of the wafer. In particular, there are plural measurement points in longitudinal direction of the exposure slit, i.e., a direction orthogonal to the scan direction, at front and back stages to the exposure slit area to measure an inclination or tilt of the surface as well as a height or focus of the wafer surface position. In general, the scan exposure proceeds in both directions from the upper stage and from the back stage. Therefore, these measurement points are arranged at front and back stages to the exposure slit area so as to measure the focus and tilt on the wafer before exposure. Japanese Laid-Open Patent Application No. 9-45609 (corresponding to U.S. Pat. No. 5,750,294) discloses, for example, a method for measuring such focus and tilt.
Japanese Laid-Open Patent Application No. 6-260391 (corresponding to U.S. Pat. No. 5,448,332) proposes, as a method for measuring a surface position on a wafer in a scanner and for correction the same, an arrangement of plural measurement points on a pre-scan area other than the exposure area to measure the focus and tilt in scan and non-scan directions. Japanese Laid-Open Patent Application No. 6-283403 (corresponding to U.S. Pat. No. 5,448,332) proposes as a method for measuring the focus and tilt in the scan and non-scan directions and for driving and correcting the same, by arranging plural measurement points in the exposure area.
A description will be given of these proposals with reference to FIGS. 10 and 11 . Here, FIG. 10 is a schematic sectional view of focus and tilt measurement points FP 1 to FP 3 on the wafer 1000 . FIG. 11 is a schematic sectional view showing the wafer 1000 that has been driven to an optimal exposure image-surface position based on the measurement results. Referring to FIG. 10 , the focus and tilt are sequentially measured at the measurement points FP 1 to FP 3 on the wafer 1000 . A pre-scan plane PMP is calculated based on the measurement results from the measurement points FP 1 to FP 3 , and the orientation of the wafer is driven and adjusted to the best focus plane BFP in moving the wafer 1000 to the exposure position or exposure slit 2000 , as shown in FIG. 11 .
However, the recent increasingly shortened wavelength of the exposure light and the higher NA of the projection optical system have required an extremely small depth of focus (“DOF”) and a stricter accuracy with which the wafer surface to be exposed is aligned to the best focus position BFP or so-called focus accuracy.
In particular, they have also required stricter measurement and precise correction of the tilt of the wafer surface in the scan direction or width direction of the exposure slit. A wafer having an insufficiently flat surface has disadvantageous focus detection accuracy in the exposure area. For example, when the exposure apparatus has a DOF with 0.4 μm, the flatness of the wafer requires several nanometer order, for example, the flatness of the wafer needs 0.08 μm where it is one-fifth as long as the DOF, or 0.04 μm where it is one-tenth as long as the DOF.
In addition, while a surface-position detector in the oblique light projection system measures the wafer's surface position before the area hangs over the exposure slit, the measurement timing is discrete and no information is available or considered about the wafer's flatness between two timings. As a result, there is no information available between timings of the flatness of the wafer.
For example, this measurement timing is at an interval of 3 mm on the wafer 1000 in the scan direction as shown in FIG. 12 . Then, the wafer 1000 has such an insufficient flatness due to lack of the information for a distance of 3 mm, e.g., between points P 1 to P 2 in FIG. 12 that the front position may offset by Δ from the pre-scan plane PMP calculated by the measurement at the interval of 3 mm. Here, FIG. 12 is a schematic sectional view showing an offset of flatness between the pre-scan plane PMP and the wafer 1000 .
In exposure, the pre-scan plane PMP is adjusted to the best focus plane BFP, and the exposure in FIG. 12 needs a shift by the amount of Δ. This shift occurs in a direction orthogonal to the scan direction as well as the scan direction. This results from an arrangement of measurement points in the above oblique light projection system, rather than the measurement timing.
The finer measurement timing in the scan direction and the increased number of measurement points in the oblique light projection system would reduce an offset error, but might disadvantageously lower the throughput due to the deteriorated scan speed in exposure time, increase measurement time, rise cost together with the complicated apparatus structure, and grows likelihood of troubles.
BRIEF SUMMARY OF THE INVENTION
Accordingly, it is an exemplified object of the present invention to provide an exposure method and apparatus for performing a superior focus correction for the flatness of the wafer surface without lowering the throughput.
An exposure method of one aspect of the present invention for exposing a pattern formed on a reticle onto an object includes a flatness measurement step for measuring and for storing the flatness of the object, a position measurement step for measuring positions at plural points on the object, and a control step for controlling at least one of the position and tilt of the object using information of the flatness obtained by the flatness measurement step, and information on the position obtained by the position measurement step. The position measurement step may be conducted in an exposure apparatus, whereas the flatness measurement step measures the flatness of the object inside or outside the exposure apparatus.
Other objects and further features of the present invention will become readily apparent from the following description of the embodiments with reference to accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic block diagram of an exposure apparatus of one embodiment according to the present invention.
FIG. 2 is a schematic view of an exposure area that includes three measurement points.
FIG. 3 is a schematic view of an exposure area that includes five measurement points.
FIG. 4 is a schematic optical view showing a measurement system of an exposure station shown in FIG. 1 .
FIG. 5 is a schematic arrangement view of a measurement optical system that realizes an arrangement of measurement points shown in FIG. 4 .
FIG. 6 is a schematic perspective view showing exposure position and focus and tilt measurement positions on a wafer.
FIG. 7 is a schematic perspective view showing the wafer that has been drive to the exposure position based on flatness information of the wafer obtained by measurement and exposure stations in FIG. 1 .
FIG. 8 is a flowchart for explaining a device fabrication method using an inventive exposure apparatus.
FIG. 9 is a detailed flowchart for Step 4 shown in FIG. 8 .
FIG. 10 is a schematic sectional view showing focus and tilt measurement positions on a wafer.
FIG. 11 is a schematic sectional view showing the wafer that has been driven to an optimal image-surface position based on the measurement result.
FIG. 12 is a schematic sectional view showing an offset between a pre-scan plane and the wafer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The instant inventor has discovered that the flatness of the wafer, in particular, the flatness among measurement points (e.g., at an interval of 3 mm) of a wafer supported on a wafer chuck in an exposure apparatus does not vary during a semiconductor process. In other words, the flatness of the original wafer without a resist or pattern before the semiconductor fabrication process is the same as the flatness of the wafer that has experienced the process including, for example, an oxide-film formation and a metal process.
A process that heats up the entire wafer might cause a whole contraction, a temperature difference between the front and rear surfaces, and thus a rough shape as a whole. However, when the wafer is supported on a wafer chuck in an exposure apparatus, which rectifies its flatness, the wafer surface does not have such a rough shape. The issue in this case is the flatness in a minute interval of, for example, 3 mm that has existed in the wafer before the semiconductor fabrication process.
A description will be given of an exposure apparatus of one embodiment according to the present invention with reference to the accompanying drawings. However, the present invention is not limited to these embodiments, and each element is replaceable within a scope of the present invention. Here, FIG. 1 is a schematic block diagram of the exposure apparatus 1 of one embodiment according to the present invention.
The exposure apparatus includes, as shown in FIG. 1 , a measurement station 100 and an exposure station 200 , and serves as a projection exposure apparatus that exposes onto a wafer a circuit pattern created on the reticle, e.g., in a step-and-repeat or a step-and-scan manner. Such an exposure apparatus is suitable for a sub-micron or quarter-micron lithography process, and this embodiment exemplarily describes a step-and-scan exposure apparatus (which is also called “a scanner”).
A description will now be given of the measurement station 100 that measures the flatness of the entire wafer 300 before the semiconductor fabrication process starts. Each wafer 300 , a silicon wafer without a resist or pattern which is ready for the semiconductor process, is fed to the measurement station 100 , which in turn measures the entire flatness before the wafer is fed to the exposure station 200 in order to lead the wafer to the semiconductor process. A spin coater has not yet formed any resist on a surface of the wafer 300 . The instant embodiment measures a surface shape of the entire wafer 300 using,a principle of a Fizeau interferometer.
The light emitted from a light source of the interferometer, such as a He—Ne laser 110 , is reflected by a beam splitter 111 , and expanded to a wafer size to be inspected by a beam expander 112 , before entering a mirror 113 used to generate reference light. The reference-light mirror 113 has one reflective surface, and uses the reflected light on the surface as the reference light that interferes with the reflected light from an object to be inspected. Although the light reflected by mirror 113 is used as the reference light and thus 113 is referred to as a reference-light mirror, the transmission light through this mirror is more than the reflected light in order to improve the visibility as contrast of interference fringes. The instant embodiment inspects the silicon wafer, and its reflectance is about 60% for the He—Ne laser with an oscillation wavelength of 633 nm. Since more improved visibility of interference fringes is available when the reflected light from the inspected object and reference light has the same intensity on a surface that forms interference fringes, i.e., a surface of a CCD camera 116 , the transmittance T on the one surface of the reference-light mirror 113 is calculated by the following equation 1 where R is the reflectance on the one surface of the reference-light mirror 113 :
T+R =1
0.6T 2 =R EQUATION 1
It is thus understood that the transmittance T is 0.703 and the reference-light mirror 113 preferably transmits 70% of light.
The light that has passed the reference-light mirror 113 illuminates the surface of the wafer 300 as an object to be inspected, which has been supported on a wafer chuck 114 . The light reflected on the wafer 300 passes through the reference-light mirror 113 , the beam expander 112 , and the beam splitter 111 , and is expanded by a beam expander 115 to the size suitable for the CCD camera 116 for photoelectric conversion of the interference fringes of the light that has transmitted through the beam splitter 111 . The light incident upon the CCD camera 116 is photo-electrically converted into a video signal representative of information of flatness of the wafer 300 .
Then, the interval available to obtain from the flatness information on the wafer 300 is calculated. Suppose that the CCD camera 116 has a photoelectric surface of ⅔ inches and each interval of light receiving cells are 13 μm. In addition, suppose that the wafer size to be inspected has a diameter of 12 inches or 300 mm. The size of photoelectric surface of ⅔ inches is 6.6×8.8 mm 2 and thus may receive light with a diameter of 6 mm.
Accordingly, the diameter of 300 mm is set to be a diameter of 6 mm. In other words, when the optical magnification from the wafer 300 to the CCD camera 116 is set to 6/300= 1/50, the separable interval on the wafer 300 becomes 13×50=650 μm from the interval between the light receiving cells of 13 μm in the CCD camera 116 .
Thus, one piece of information on the flatness is obtained from one pixel in the CCD camera 116 . This may measure the flatness of the wafer 300 for each 0.65 mm, and provide the information of flatness between the measurement interval of, for example, 3 mm, the focus measurement in the scan direction in the exposure station 200 .
The measurement station 100 may measure the flatness of the wafer 300 using the principle of the Fizeau interferometer more precisely than a detection system 260 for detecting the focus and tilt in the exposure station 200 , and obtain the flatness information of the wafer 300 between detection intervals of the detection system 260 . When this flatness information is converted into a database for each wafer and made available as a reference table to a controller 270 in the exposure station 200 , each wafer may be recognized in the advanced stage in the semiconductor process and exposed based on this flatness information and focus and tilt information of the wafer 300 detected in the exposure station 200 .
The wafer 300 is moved to the exposure station 200 as shown in FIG. 1 after its flatness information has been measured by the measurement station 100 before the exposure, and then the exposure station 200 exposes the wafer 300 based on the flatness information of the wafer 300 . The moving wafer 300 is the best configuration because one by one movement does not stop the whole stream for high throughput, but the wafer carrier (not shown) etc. may move every twenty-five wafers, for example, to the exposure station 200 when the decreased throughput is permissible to some extent.
A description will now be given of the exposure station 200 . The light emitted from a light source 210 , such as an excimer laser, illuminates a pattern formed on a reticle 230 through an illumination optical system 220 that converts the light into exposure light with an optimal shape. The pattern on the reticle 230 includes an IC circuit pattern to be exposed, and the light emitted through the pattern forms an image near the wafer 300 surface as an image surface through a projection optical system 240 .
The reticle 230 is mounted on a reticle stage 235 movable in a plane orthogonal to an optical axis of the projection optical system 240 and in the optical-axis direction.
The wafer 300 is brought in from the measurement station 100 and mounted on a wafer stage 250 movable in a plane orthogonal to an optical axis of the projection optical system 240 and in the optical-axis direction.
Each shot area on the reticle 230 is exposed by relatively scanning the reticle stage 235 and wafer stage 250 at a speed corresponding to a ratio of an exposure magnification. After one shot of exposure ends, the wafer stage 250 is stepped to the next shot and next shot is exposed by the scan exposure in the reverse direction to the previous one. This repeats to expose the entire shot area on the wafer 300 .
During the scan exposure of one shot, the detection system 260 obtains surface position information on the surface of the wafer 300 to measure the focus and tilt, calculates the offset amount from the exposure image surface, and drives the stage 250 in focus (or height) and tilt (or inclination) directions, aligning the wafer 300 surface in the height direction for almost each exposure slit.
The detection system 260 uses an optical height measurement system using a method for introducing light to the wafer 300 surface at a large angle (or low incident angle) and detecting an image offset of the reflected light from the wafer using a position detecting element, such as a CCD camera. It projects light to plural measurement points on the wafer 300 , introduces each light to an individual sensor, and calculates the tilt of a surface to be exposed based on the height measurement information of different positions.
Plural measurement points K 1 to K 5 are arranged, as shown in FIGS. 2 and 3 , to form a surface shape in the front and back areas 510 and 520 in the exposure area 500 (or exposure slit) 500 , so as to simultaneously measure focus and tilt information of the wafer 300 , in particular, tilt information in the scan direction before the exposure slit in the scan exposure moves to the exposure area 500 . FIGS. 2 and 3 are schematic views of the measurement points K 1 to K 5 for the exposure area 500 , in which FIG. 2 shows three measurement points K 1 to K 3 while FIG. 3 shows five measurement points K 1 to K 5 .
FIG. 3 arranges five measurement points K 1 to K 5 to be projected in the front area 510 for the exposure area 500 so as to precisely obtain focus and tilt information just before the exposure to the exposure area 500 , and drive and correct an exposure position. Similarly, five measurement points K 1 to K 5 are to be projected in the back area 520 for the scan exposure in the reverse direction.
FIG. 4 shows an enlarged view of an area A in FIG. 1 . Here, FIG. 4 is a schematic optical view showing a focus and tilt measurement system in the exposure station 200 , although FIG. 4 shows only five measurement points K 1 to K 5 in the focus and tilt measurement area (for instance, the front area 510 ) for illustrative convenience. In particular, the instant embodiment illustrates an arrangement of marks M 2 to M 5 wherein an interval between the measurement points K 2 and K 4 is different from that among the measurement points K 1 , K 3 and K 5 . Plural optical axes for the focus and tilt measurement are aligned with a direction orthogonal to the scan direction. These marks M 1 to M 5 to be projected at the measurement points K 1 to K 5 are rotated by a certain amount in a section perpendicular to the optical axis of the focus and tilt measurement optical system and then projected. As a result, the measurement slit faces obliquely on the wafer 300 and the slit pitch direction directs to the central measurement position.
FIG. 5 is a schematic arrangement view of the measurement optical system for realizing an arrangement of the measurement points shown in FIG. 4 . Five illumination lenses 261 allows the light supplied from the light source (not shown) to illuminate slit marks for the focus measurement formed on the projection pattern mask 262 for the focus and tilt measurements. The light source preferably employs a halogen lamp or LED with such a relatively wide wavelength that the light does not expose the photoresist on the wafer 300 or is not affected by interference in the resist thin film. The mask 262 forms slit marks for plural measurement points as shown in a diagram viewed from a direction A. An optical-path synthesizer prism 263 synthesizes optical paths of beams formed from illuminated plural measurement marks, and a focus mark projection optical system 264 projects the light onto the wafer 300 obliquely.
The light reflected on the wafer 300 surface forms an intermediate imaging point in an optical-path division prism 266 through the focus light-receiving optical system 265 . After the optical-path division prism 266 divides the optical path for each measurement point, an enlargement detection optical system 267 arranged for each measurement point in order to improve measurement resolution introduces the light to a position detection element 268 for each measurement point. Each position detection element 268 uses one-dimensional CCD in this embodiment, and the arrangement direction of the elements is the measurement direction. A diagram viewed from the direction B shows a relationship among the measurement marks, the position detection element 268 , and the enlargement detection optical system 267 . The position detection element 268 for each measurement point is provided in a direction orthogonal to the slit mark.
The position detection element 268 uses a one-dimensional CCD, but may arrange a two-dimensional CCD. Alternatively, it may be adapted to form a reference slit plate on a light-receiving element imaging surface, scan light in front of the reference slit plate, and detect a transmission light volume through the reference slit plate.
A description will be given of an overview of a surface position correction in the focus and tilt measurement at the scan exposure. Before the exposure position EP moves to the wafer 300 with a rough shape in a scan direction SD, the focus of the surface position of the wafer 300 , the tilt in the longitudinal direction in the exposure slit (or a direction perpendicular to the scan direction SD) (which tilt is referred to as “tilt X”) as well as the tilt in the width direction in the exposure slit (which tilt is referred to as “tilt Y”) are conducted, as shown in FIG. 6 , plural focus and tilt positions FP arranged so as to form a plane in front of the exposure slit. Based on the information of the measurement and flatness information of the wafer 300 as a database, the controller 270 provides a corrective driving, as shown in FIG. 7 , to drive the wafer stage 250 to the exposure position EP. In FIG. 7 , the correction has been completed so as to expose the exposure slit when the exposure slit moves to the area that has been measured before the exposure. The controller 270 may communicate with the measurement station 100 , and obtains and stores a database of the flatness of the wafer 300 that has been obtained from the measurement station 100 . Here, FIG. 6 is a schematic perspective view showing the exposure position EP, focus and tilt measurement positions FP on a wafer 300 . FIG. 7 is a schematic perspective view showing the wafer 300 that has been drive to the exposure position EP based on flatness information of the wafer 300 obtained by measurement and exposure stations 100 and 200 .
The above description refers to an arrangement of five measurement points in each surface position measurement area, but is applicable to an arrangement of three measurement points.
Referring now to FIGS. 8 and 9 , a description will be given of an embodiment of a device fabrication method using the above mentioned exposure apparatus 1 . FIG. 8 is a flowchart for explaining how to fabricate devices (i.e., semiconductor chips such as IC and LSI, LCDs, CCDs, and the like). Here, a description will be given of the fabrication of a semiconductor chip as an example. Step 1 (circuit design) designs a semiconductor device circuit. Step 2 (mask fabrication) forms a mask having a designed circuit pattern. Step 3 (wafer making) manufactures a wafer using materials such as silicon. Step 4 (wafer process), which is also referred to as a pretreatment, forms actual circuitry on the wafer through lithography using the mask and wafer. Step 5 (assembly), which is also referred to as a post-treatment, forms into a semiconductor chip the wafer formed in Step 4 and includes an assembly step (e.g., dicing, bonding), a packaging step (chip sealing), and the like. Step 6 (inspection) performs various tests for the semiconductor device made in Step 5 , such as a validity test and a durability test. Through these steps, a semiconductor device is finished and shipped (Step 7 ).
FIG. 9 is a detailed flowchart of the wafer process in Step 4 in FIG. 8 . Step 11 (oxidation) oxidizes the wafer's surface. Step 12 (CVD) forms an insulating film on the wafer's surface. Step 13 (electrode formation) forms electrodes on the wafer by vapor disposition and the like. Step 14 (ion implantation) implants ion into the wafer. Step 15 (resist process) applies a photosensitive material onto the wafer. Step 16 (exposure) uses the exposure apparatus 300 to expose a circuit pattern on the mask onto the wafer. Step 17 (development) develops the exposed wafer. Step 18 (etching) etches parts other than a developed resist image. Step 19 (resist stripping) removes disused resist after etching. These steps are repeated, and multi-layer circuit patterns are formed on the wafer. Use of the fabrication method in this embodiment helps fabricate higher-quality devices than ever. Thus, the device fabrication method using the exposure apparatus 1 and the resultant device constitute one aspect of the present invention.
Further, the present invention is not limited to these preferred embodiments and various variations and modifications may be made without departing from the scope of the present invention.
According to the inventive exposure method and apparatus, may perform a superior focus correction for the flatness of the wafer surface without lowering the throughput. The device fabrication method using this device and method may fabricate high-quality devices.
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An exposure method for exposing a pattern formed on a reticle onto an object includes a flatness measurement step for measuring the flatness of the object and storing the information obtained, a position measurement step for measuring positions at plural points on the object, and a changing step for changing at least one of the position and tilt of the object on the basis of the information obtained by the flatness measurement step, and information on the position obtained by the position measurement step.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an image heating apparatus for heating a toner image formed on a recording material, and more particularly to an image heating apparatus adapted for use as a fixing apparatus to be mounted on an image forming apparatus such as a copying apparatus or a printer.
[0003] 2. Related Background Art
[0004] As a fixing apparatus equipped in an image forming apparatus of electrophotographic process or electrostatic recording process, there has been widely employed a heat fixing device of so-called heat roller type, in which a recording material bearing an unfixed toner image is passed through a nip portion formed by a fixing roller and a pressure roller which are rotated in a mutually pressed state, thereby fixing the unfixed toner image onto the recording material as a permanent image.
[0005] On the other hand, a reduction in the electric power consumption is strongly desired as a recent environmental issue while a high image quality and a high speed in the image output are requested from market demands. Thus, various improvements are being tried in the heat fixing apparatus of the aforementioned heat roller type, in order to meet such requirements for the decreased electric power consumption and for the high image quality and the high speed.
[0006] The present applicant has proposed, in Japanese Patent Application Laid-Open No. 2003-182367, an image heating apparatus capable, as a fixing apparatus, of achieving an image output with a high image quality at a high speed, while maintaining a reduced electric power consumption and a shortened heating time. This fixing apparatus, as shown in FIG. 11 , is provided with a fixing roller 20 having an elastic layer 22 , a heating member 24 in contact with an external surface of the fixing roller 20 thereby forming a heating nip N, and a pressure member 30 maintained in a pressurized contact with the fixing roller thereby forming a fixing nip portion (conveying rip portion) M, in which a recording material P bearing an unfixed toner image t is pinched and conveyed to achieve heat fixation (apparatus of this type being hereinafter called “external heating type”).
[0007] Also a heater 26 equipped on the heating member 24 is of a plate shape of a low heat capacity, of such a type generating heat in sliding contact with the heating nip N. Such configuration allows to achieve a higher energy density at the heating nip N in comparison with a structure of heating the surface of the heating roller by a heat roller in contact with the surface of the fixing roller, thereby enabling to promptly heating the surface of the fixing roller.
[0008] Also the contact of the elastic member 22 of the fixing roller with the recording material P or the toner t is equivalent to that in a heat roller type having an elastic layer, as employed in a prior high-speed apparatus, so that a high image quality can be maintained even for a higher speed in the image forming apparatus. Thus, such system is capable of simultaneously satisfying all the requirements, such as a reduction in the start-up time, a reduction in the electric power consumption, and a high-quality image output in a high-speed operation.
[0009] However, in the fixing apparatus shown in FIG. 11 , in the heat fixation of a recording material, the toner on the recording material may be offset to the fixing roller, and such offset toner is deposited onto the surface of the heating member by the frictional contact between the heating member and the fixing roller. As the heat fixing operation is repeated, such offset toner is accumulated on the surface of the heating member, and, upon exceeding a certain amount, is peeled from the surface of the heating member and transferred onto the recording material thereby forming an image defect.
SUMMARY OF THE INVENTION
[0010] The present invention has been made in consideration of the aforementioned drawbacks, and an object of the present invention is to provide an image heating apparatus capable of suppressing a stain on the recording material, caused by a toner offset to the image heating apparatus.
[0011] Another object of the present invention is to provide an image heating apparatus of external heating type, capable of suppressing an accumulation of the toner deposited onto heating means of such image heating apparatus.
[0012] A further purpose of the invention is to provide an image heating apparatus for heating a toner image formed on a recording material, including: a rotatable member; heating means which heats an outer peripheral surface of the rotatable member, the heating means including a heater for forming a heating nip portion in cooperation with the rotatable member; back-up means which forms a conveying nip portion in cooperation with the rotatable member, the conveying nip portion conveying the recording material; and control means which controls a temperature of the heater and a rotation of the rotatable member; wherein the apparatus has a cleaning mode to remove toner from the heating means, and the control means rotates or reversely rotates the rotatable member in a condition that the heater dissipates heat in the cleaning mode.
[0013] Still other objects of the present invention will become fully apparent from the following detailed description to be taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a schematic view showing a configuration of an image forming apparatus;
[0015] FIG. 2 is a view showing an operation sequence of an image forming apparatus of an embodiment 1;
[0016] FIG. 3 is a schematic view showing a configuration of a heat fixing apparatus in the embodiment 1;
[0017] FIG. 4 is a schematic cross-sectional view of the heating fixing apparatus shown in FIG. 2 , along a line B-B therein;
[0018] FIG. 5 is a magnified view of a heating nip portion shown in FIG. 2 ;
[0019] FIG. 6 is a schematic view showing a temperature control of a heater in a control mode, a temperature behavior of the heater, and a rotation control of a fixing roller;
[0020] FIG. 7A is a view showing an operation of transferring a toner, deposited in an upstream side of the heater in a rotating direction of the fixing roller, from the fixing roller to a pressure member;
[0021] FIG. 7B is a view showing an operation of transferring a toner, deposited in a downstream side of the heater in a rotating direction of the fixing roller, from the fixing roller to a pressure member;
[0022] FIG. 7C is a view showing an operation of transferring a toner, transferred onto the pressure member, onto a recording material;
[0023] FIG. 8 is a view showing an operation sequence of an image forming apparatus of an embodiment 2;
[0024] FIG. 9 is a schematic view showing a configuration of a heat fixing apparatus in the embodiment 2;
[0025] FIG. 10 is a schematic view showing a temperature control of a heater in a control mode, a temperature behavior of the heater, and a rotation control of a fixing roller; and
[0026] FIG. 11 is a schematic cross-sectional view of a prior heating fixing apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] In the following, embodiments of the present invention will be explained with reference to the accompanying drawings.
Embodiment 1
[0028] (1) Example of Image Forming Apparatus
[0029] FIG. 1 is a schematic view showing a configuration of an image forming apparatus. The image forming apparatus of the present embodiment is a laser beam printer utilizing an electrophotographic process of transfer type.
[0030] An electrophotographic photosensitive member of a rotary drum shape (hereinafter called photosensitive drum) serving as an image bearing member is constituted of a photosensitive material such as an OPC, amorphous Se or amorphous Si formed on a cylindrical substrate such as of aluminum or nickel.
[0031] The photosensitive drum 1 is rotated with a predetermined peripheral speed clockwise as indicated by an arrow, and a surface thereof is at first uniformly charged at predetermined polarity and potential by a charging roller 2 serving as a charging apparatus.
[0032] Then the charged surface is subjected to an exposure corresponding to image information by a laser scanner 3 . The laser scanner 3 irradiates the uniformly charged surface of the rotary photosensitive drum 1 with a laser beam L which is on/off controlled (modulation control) according to a time-sequential electrical digital image signal of image information. Thus the potential of the uniformly charged surface of the photosensitive drum 1 is attenuated in an exposed portion, whereby an electrostatic latent image is formed corresponding to the image information, on the photosensitive drum.
[0033] The electrostatic latent image is developed and rendered visible as a toner image in a developing apparatus 4 . Such development can be executed for example by a jumping development, a two-component development or a FEED development, and an imagewise exposure and a reversal development are often employed in a combination.
[0034] The visible toner image is transferred, at a transfer nip portion A formed by a pressed contact of the photosensitive drum 1 and a transfer roller 5 constituting a contact transfer apparatus pressed thereto, from the surface of the photosensitive drum 1 onto a surface of a recording material P which is supplied at a controlled timing from a sheet feeding mechanism 6 to the transfer nip portion.
[0035] More specifically, a timing of conveying of the recording material is controlled according to front end position information of the recording material P, detected by a sensor 7 in such a manner that the toner image on the photosensitive drum 1 coincides with a writing start position at the front end of the recording material. The recording material P conveyed at a predetermined timing is, at the transfer nip portion A, pinched and conveyed under a predetermined pressure by the photosensitive drum 1 and the transfer roller 5 whereby the toner image on the surface of the photosensitive drum 1 is transferred onto the recording material P by an electrical force and a pressure.
[0036] The recording material P, upon passing through the transfer nip portion A, is separated from the surface of the photosensitive drum 1 and conveyed to a heat fixing apparatus 9 , in which the unfixed toner image is heat fixed as a permanent image on the surface of the recording material. The recording material subjected to image fixation is conveyed to a sheet discharging mechanism 10 .
[0037] A transfer residual toner, remaining on the photosensitive drum 1 after the separation of the recording material, is removed by a cleaning apparatus 8 from the surface of the photosensitive drum 1 , which is then used in image formation in repetition.
[0038] (2) Operation Sequence of Printer
[0039] In the following, an operation sequence of the above-described printer will be explained with reference to FIG. 2 .
A: Pre multi-rotation step: This is a starting operation period (starting operation period or warming-up period) of the printer. In response to a turning-on of a main switch of the apparatus, a main motor of the apparatus is driven to rotate the photosensitive drum thereby executing preparatory operations for predetermined process devices. B: Initial rotation step: This is a period for executing a pre-print operation. In case a print signal is entered during the pre multi-rotation step, this initial rotation step is executed in succession to the pre multi-rotation step. In case a print signal is not entered, the main motor is once deactivated to terminate the rotation of the photosensitive drum 1 , and the printer is maintained in a stand-by (waiting) state until a print signal is entered. The initial rotation step is executed in response to an entry of a print signal. C: Printing step (image formation step, imaging step): After the predetermined initial rotation step, there are executed an image formation step on the photosensitive drum 1 , a transfer of the toner image formed on the photosensitive drum 1 onto the recording material P, and a fixing process for the toner image by the fixing means, whereupon a formed image is outputted. In a continuous print mode, the aforementioned printing step is repeatedly executed by a preset print number. D: Sheet interval step: This is a sheet non-passing period in the transfer nip portion A, in a continuous printing mode, from a passing of a rear end of a recording material P through the transfer nip portion A to an arrival of a front end of a succeeding recording material P at the transfer nip portion A. E: Post-rotation step: This is a period in which the main motor is maintained active to continue the rotation of the photosensitive drum 1 for a while after the end of the printing step for a last recording material P, in order to execute a predetermined post-operation. F: Cleaning step (cleaning sequence): This is a period in which an offset toner, accumulated in the heating nip portion between the fixing roller and the heating member in the heat fixing apparatus 8 , thereby cleaning the heating member. The cleaning step will be detailedly explained in the following. G: Stand-by: After the end of the predetermined post-rotation step, the main motor is deactivated to terminate the rotation of the photosensitive drum 1 , whereby the printer is maintained in a stand-by state until a next print start signal is entered.
[0047] In case of a single print only, the printer enters the stand-by state after executing the post-rotation step. In the stand-by state, the printer enters the initial rotation step upon receiving a print start signal.
[0048] The printing step C constitutes an image forming period, while the pre multi-rotation step A, the initial rotation step B, the sheet interval step D, the post-rotation step E and the cleaning step F constitute an image non-forming period (image non-formation state).
[0049] The main motor drives the photosensitive drum 1 , the sheet feeding mechanism 6 , the developing apparatus 4 , the transfer apparatus 5 , the heat fixing apparatus 9 and the sheet discharge mechanism 10 .
[0050] (3) Heat Fixing Apparatus
[0051] FIG. 3 is a schematic view of the heat fixing apparatus 6 of the present embodiment, and FIG. 4 is a schematic view of the heat fixing apparatus shown in FIG. 3 along a line B-B therein.
[0052] The heat fixing apparatus is principally provided with a fixing roller (rotatable member) 20 having an elastic layer, a heating member (heating means) 24 maintained in cfontact with an external surface (external periphery) of the fixing roller 20 to form a heating nip portion N thereby heating and causing a temperature elevation on the external surface of the fixing roller 20 , and a pressure member (backup means) 30 in a mutual pressurized contact with the fixing roller 20 thereby forming a fixing nip portion (conveying nip portion) M.
[0053] 1) Fixing Roller (Rotatable Member) 20
[0054] The fixing roller 20 is constituted of following members. It is basically constituted by forming, on an external surface or an external periphery of an aluminum or iron metal core 21 , an elastic layer 22 (solid rubber layer) formed by silicone rubber, or an elastic layer (sponge rubber layer) formed by foaming silicone rubber for providing a heat insulating effect, or an elastic layer (bubbled rubber layer) formed by dispersing bubbles within a silicone rubber layer by any method thereby increasing the heat insulating effect.
[0055] However, the fixing roller, in case having a large heat capacity and also even a slightly large thermal conductivity, tends to absorb the heat received from the external surface whereby the surface temperature of the fixing roller cannot be easily elevated. For this reason, the elastic layer 22 is advantageously formed by a material of a low heat capacity, a low thermal conductivity and a high heat insulating effect as far as possible, in order to shorten a time required by the surface temperature of the fixing roller to reach a predetermined temperature.
[0056] The thermal conductivity is 0.25 to 0.29 W/m·K in silicone solid rubber, while that in sponge rubber and bubbled rubber is 0.11 to 0.16 W/m·K, namely about a half of that in the solid rubber.
[0057] Also a specific gravity, relating to the heat capacity, is about 1.05 to 1.30 in the solid rubber while it is about 0.75 to 0.85 in the sponge rubber or in the bubbled rubber.
[0058] Therefore, the elastic layer 22 is preferably constituted of a sponge rubber layer or a bubbled rubber layer of a high heat insulating effect, having a thermal conductivity of about 0.15 W/m·K or less and a specific gravity of 0.85 or less.
[0059] Also in the fixing roller 20 , a smaller external shape (external diameter) allows to suppress the heat capacity, but a certain diameter is necessary since the heating nip N becomes difficult to form at an excessively small diameter.
[0060] Also in the elastic layer 22 , a certain appropriate thickness is necessary as an excessively thin layer stimulates heat dissipation to the metal core 21 .
[0061] In consideration of the foregoing, the present embodiment employs an elastic layer 22 formed with a bubbled rubber of a thickness of 4 mm and a fixing roller 20 with an external diameter of 20 mmφ in order to form an appropriate heating nip N and to suppress the heat capacity.
[0062] On the aforementioned elastic layer 22 , there is formed a releasing layer 23 of a fluorinated resin such as perfluoroalkoxy resin (PFA), polytetrafluoroethylene (PTFE) or tetrafluoroethylene-hexafluoropropylene resin (FEP). The releasing layer 23 may be formed as a tube or formed by coating, but a tube is superior in durability.
[0063] The fixing roller 20 of the aforementioned configuration is rotatably supported, at both ends 21 a of the metal core 21 , by bearings 51 on a pair of roller support members 50 as shown in FIG. 4 .
[0064] 2) Heating Means 24
[0065] The heating means 24 is constituted of following members. A plate-shaped heater (heating member) 26 of a low heat capacity is maintained, at a surface at the side of the fixing roller 20 , in contact with the external surface of the fixing roller 20 , thereby heating the external surface thereof. The heater 26 is constituted by forming, on a surface of a highly insulating ceramic substrate such as of alumina or aluminum nitride, a heat-generating resistor layer such as of Ag/Pd (silver-palladium), RuO 2 or Ta 2 N for example by screen printing along a longitudinal direction. The heat-generating resistor layer has a line or stripe shape with a thickness of about 10 μm and a width of about 1 to 5 mm.
[0066] On the surface of the heater 26 , there is preferably formed a protective slidable layer in order to avoid an abrasion of the releasing layer 23 of the fixing roller 20 by friction. The protective layer can be formed, for example, by coating a fluorinated resin such as perfluoroalkoxy resin (PFA), polytetrafluoroethylene resin (PTFE), tetrafluoroethylene-hexafluoropropylene resin (FEP), polychlorotrifluoroethylene resin (CTEF) or polyvinylidene fluoride (PVDF) singly or in a mixture, a dry film lubricant constituted for example of graphite, diamon-like carbon (DLC) or molybdenum disulfide, or a glass coating.
[0067] A heat insulating stay holder 25 is provided for supporting the heater 26 . The heat insulating stay holder 25 is pressed, at both ends thereof as shown in FIG. 4 , toward the fixing roller 20 by pressurizing means (such as coil springs) 53 , and a heating nip portion N is formed by such pressure between the heater 26 and the fixing roller 20 . The heat insulating stay holder 25 has a function of preventing heat dissipation in a direction opposite to the heating nip portion N, and can be formed for example with a liquid crystal polymer, phenolic resin, PPS, or PEEK.
[0068] On the rear surface of the heater 26 , there is provided a temperature detector (temperature detection means) 27 such as a thermistor for detecting the temperature of the ceramic substrate heated by the heat generated in the heat-generating resistor layer. In response to a signal from the temperature detector 27 , a temperature controller (temperature control means) 34 shown in FIG. 3 suitably controls a duty ratio or a frequency of a voltage applied to the heat-generating resistor layer from unillustrated terminals provided on both ends thereof, thereby achieving a temperature control of the heater 26 . More specifically, the temperature controller 34 so controls the current supply to the heater 26 that the temperature detected by the temperature detector 27 is maintained at a set temperature. In the fixing apparatus of the present embodiment, the temperature control of the heater 26 allows to maintain, within the surface of the fixing roller 20 , a surface portion thereof moving from the heat nip portion N toward the conveying nip portion M at a temperature suitable for fixing. A DC current supply from the temperature detector 27 to the temperature controller 34 is achieved by an unillustrated DC power supply and DC electrodes, across an unillustrated connector.
[0069] 3) Pressurizing Member (Backup Means) 30
[0070] The pressurizing member 30 has a following configuration. A sliding film (flexible sleeve) 33 of a cylindrical shape is constituted of a resinous film having a heat-resistant and thermoplastic base layer for example of polyimide, polyamidimide, PEEK, PPS, PFA, PTFE or FEP. An appropriate thickness range of the film is equal to or larger than 20 μm but smaller than 150 μm, in consideration of the strength. An external shape (external diameter) of the sliding film is made smaller than the external shape of the fixing roller 20 .
[0071] There are also provided a slidable plate (slidable member) provided inside the sliding film 33 , and a heating insulating stay holder 32 supporting the slidable plate 31 .
[0072] The heat insulating stay holder 32 is pressed, at both ends thereof as shown in FIG. 4 , toward the fixing roller 20 by pressurizing means (such as coil springs) 54 , and a fixing nip portion (conveying nip portion) M is formed between the heater 26 and the fixing roller 20 , across the sliding film 33 . The heat insulating stay holder 32 , as in case of the stay holder 25 for the heating member 24 , is formed by a heat-insulating and heat-resistant resin such as a liquid crystal polymer, phenolic resin, PPS, or PEEK. Therefore, the sliding film 33 is in contact, at the internal peripheral surface thereof, with the slidable plate 31 and, at the external peripheral surface thereof, with the external periphery of the fixing roller 20 .
[0073] The slidable plate 31 is formed with a material showing a low friction with the sliding film 33 and having a heat insulating property, such as a liquid crystal polymer, phenolic resin, PPS or PEEK as in the case of the stay holder 32 , and is preferably coated, on the surface thereof, with a slidable layer for reducing the friction resistance Examples of such layer is similar to those of the slidable layer provided on the surface of the heater 26 , and will not, therefore, be explained further.
[0074] In the present embodiment, the slidable plate 31 and the heat insulating stay holder 32 are constructed as separate members, but it is also possible to integrally form these members and to coat the aforementioned slidable layer in a sliding contact part, thereby achieving a further cost reduction. Also between the sliding film 33 and the slidable plate 31 , a small amount of lubricant such as grease, in order to reduce the friction resistance between the sliding film 31 and the slidable plate 31 .
[0075] As the present embodiment adopts a fixing roller with a diameter φ of 20 mm, an angle of 120° between a line connecting the center of the fixing roller 20 and the center of the heating nip portion N and a line connecting the center of the fixing roller 20 and the center of the fixing nip portion M, and a conveying speed of 250 mm/sec of the recording material, a time required by the surface of the fixing roller 20 to move from the center of the heating nip portion N to the center of the fixing nip portion M is as short as 0.08 seconds. Besides, as the elastic layer 22 of the fixing roller 20 is composed, as explained in the foregoing, of a sponge rubber layer or a bubbled rubber layer of a thermal conductivity of about 0.15 W/m·K or less and a specific gravity of 0.85 or less, the surface area of the fixing roller, heated by the heater 26 in the heating nip portion N, can reach the fixing nip portion M almost without a temperature loss.
[0076] 4) Operation
[0077] In such configuration, the fixing roller 20 is rotated, through the longitudinal end and the metal core 21 thereof, by the main motor (drive means) 35 of the apparatus shown in FIG. 3 , in a clockwise direction indicated by an arrow (conveying direction of the recording material). The main motor 35 is controlled by a rotation controller 36 . Also the temperature controller 34 and the rotation controller 36 are managed by a control unit 37 . By the rotation of the fixing roller 20 , the sliding film 33 at the side of the backup means 30 receives a rotating force at the fixing nip portion M and is driven counterclockwise outside the heat insulating stay holder 32 in sliding contact with the surface of the slidable plate 31 .
[0078] Also a current is supplied to the heat generating resistor layer of the heater 26 of the heating means 20 to promptly heat the heater 26 to a predetermined control temperature (set temperature), and a temperature control system including the temperature detector 27 and the temperature controller 34 controls the current supply to the heat generating resistor layer in such a manner that the heater 26 is maintained at a predetermined control temperature.
[0079] Also by the heat generation of the heater 26 , the external surface of the rotating fixing roller 20 is externally heated at the heating nip portion N and is rapidly heated to the predetermined fixing temperature. In the fixing apparatus, as explained above, the temperature control of the heater 26 allows to maintain, within the surface of the fixing roller 20 , a surface portion thereof moving from the heat nip portion N toward the conveying nip portion M at a temperature suitable for fixing.
[0080] In a state where the fixing roller 20 is rotated and the external surface thereof is heated to the predetermined fixing temperature, a recording material P bearing an unfixed toner image is introduced, from the side of the transfer nip portion A and along a heat resistant fixing entrance guide 55 , into the fixing nip portion M formed by the fixing roller 20 and the pressure roller 30 , and is pinched and conveyed by the fixing nip portion M. Thus the unfixed toner image t is fixed, by heat and pressure in the fixing nip portion M, onto the recording material P.
[0081] In the heat fixing operation of the unfixed toner image by pinching and conveying the recording material P in the fixing nip portion M, a small amount of offset toner, coming from the recording material P, is accumulated on a portion of the heater 26 in the heating nip portion N. This phenomenon will be explained with reference to FIG. 5 , which is a magnified view of the heating nip portion N formed by the pressed contact of the heater 26 and the fixing roller 20 . The offset toner t of the small amount on the fixing roller 20 is at first blocked at the upstream side of the heating nip portion N in the rotating direction of the fixing roller, then fused by heating and accumulated, as indicated by t′, on the surface of the heater 26 in the upstream side of the heating nip portion N in the rotating direction of the fixing roller. Also a part of thus accumulated toner t′ gradually moves, along with the rotation of the fixing roller 20 , through the contact portion of the heater 26 and the fixing roller 20 in the heating nip portion N toward the downstream side of the heating nip portion N in the rotating direction of the fixing roller, and is accumulated on the surface of the heater 26 after the heating nip portion. N, as indicated by t″. The toner t″ accumulating in the downstream side of the heating nip portion N is much larger in amount than the toner t, accumulating in the upstream side. When the printing operation is continued in this state, the toner t″, accumulating on the surface of the heater 26 at the downstream side in the rotating direction of the fixing roller, is returned onto the surface of the fixing roller 20 , then transported to the fixing nip portion M and is transferred onto a surface (image printing surface) of the recording material at the side of the fixing roller 20 , thereby staining the recording material P. Although the toner t′, accumulating at the upstream side of the heating nip portion N, is gradually moved in the fixing step to the downstream side of the heating nip portion N thereby merely forming the deposited toner t″, but it is desirable to remove also the accumulated toner t′ in the upstream side as well as the accumulated toner t″ in the downstream side from the heater surface.
[0082] 5) Control Mode (Cleaning Mode)
[0083] In the present embodiment, therefore, the heater 26 is turned off simultaneously with the end of the printing operation, and, after the post-rotation step explained in the foregoing, there is executed a control mode (cleaning sequence) for cleaning the heater 26 by a controller 37 shown in FIG. 3 . (Thus, the cleaning mode in the present embodiment is automatically executed after the heating step for heating the toner image on the recording material is completed.) FIG. 6 schematically shows a temperature control for the heater 26 in case of the aforementioned control mode, a temperature behavior of the heater 26 and a rotation control for the fixing roller 20 .
[0084] When the control mode is started, the temperature controller 34 starts a current supply to the heat-generating resistor layer of the heater 26 , thereby initiating a control for heating the heater 26 to a predetermined temperature T 2 higher than the fusing temperature of the toner and maintaining such temperature T 2 . Such heating mutually combines the toners deposited on the surface of the heater 26 , thereby facilitating separation from the surface of the heater 26 . The temperature T 2 may be higher or lower than the set temperature T 1 of the heater in the fixing step (image heating step) as long as it is higher than the fusing temperature of the toner. In the present embodiment, the temperature T 2 is selected lower than the temperature T 1 . While the heater 26 is controlled at the temperature T 2 , namely while the toners t′ and t″ are in the fused state, the fixing roller 20 is rotated in the forward and reverse directions. A rotation of the fixing roller causes a friction between the fixing roller and the surface of the heater, whereby the toner deposited on the surface thereof is peeled off and is transferred onto the surface of the fixing roller. Rotation angles (rotation amounts) in the forward and reverse rotations need only that a surface area of the fixing roller in contact with the heater 26 at the start of the cleaning mode can reach the fixing nip portion M, and each is preferably within 360°. Thus the toner sticking to the surface of the fixing roller 20 is carried to the fixing nip portion M, and, at the fixing nip portion M, is deposited onto the surface of the film 33 of a temperature lower than that of the fixing roller.
[0085] In the aforementioned cleaning temperature control, as shown in FIG. 6 , the rotation controller 36 turns on and off the main motor 35 alternately clockwise (reverse direction in FIG. 6 ) and counterclockwise (forward direction in FIG. 6 ), thereby causing two cycles of reciprocating rotation in the fixing roller 20 .
[0086] More specifically, the main motor 35 is turned on to rotate the fixing roller 20 counterclockwise (opposite to the conveying direction of the recording material) by a full turn (360°) and is then turned off. The counterclockwise rotation of the fixing roller 20 carries the toner t′, transferred from the surface of the heater 26 at the upstream side in the rotating direction of the fixing roller 20 , to the fixing nip portion M.
[0087] The toner t′, carried to and upon reaching the fixing nip portion M, is transferred therein onto the surface of the pressure member 30 (namely the surface of the film 33 ) of a temperature lower than that of the fixing roller 20 .
[0088] Then the rotation controller 36 turns on the main motor 35 as indicated in FIG. 7B to rotate the fixing roller 20 clockwise by a full turn (360°) and then turns off the main motor 35 . The clockwise rotation of the fixing roller 20 carries the toner t″, transferred from the surface of the heater 26 at the downstream side in the rotating direction of the fixing roller 20 , to the fixing nip portion M.
[0089] The toner t″ supported on the fixing roller 20 , upon reaching the fixing nip portion M, is transferred therein onto the surface of the pressure member 30 of a temperature lower than that of the fixing roller 20 .
[0090] The rotation controller 36 repeats the aforementioned on/off operations of the main motor 35 , whereby the fixing roller 20 is rotated in two reciprocating cycles in the counterclockwise and clockwise directions.
[0091] When two reciprocating cycles are completed, the rotation controller 36 turns off the main motor 35 and, at the same time, the temperature controller 34 turns off the current supply to the heat-generating resistor layer of the heater 26 , whereby the control mode is terminated.
[0092] Upon completion of the control mode, the image forming apparatus enters a stand-by state.
[0093] Through the aforementioned control mode (cleaning mode), the toners t′ and t″ are supported on the film 33 .
[0094] When a print start signal is entered in the aforementioned state where the toners t′ and t″ are deposited on the film 33 , a next printing operation is initiated after a initial rotation step, and a recording material P is introduced into the fixing nip portion M of the heat fixing apparatus 9 as shown in FIG. 7C . In the initial rotation step, the heater 26 generates heat to heat the fixing roller 20 , and, in the fixing nip portion M, the film 33 is also heated by the heat received from the fixing roller 20 . As the recording material P is at the normal temperature, the toners t′, t″ transferred onto the surface of the film 33 are transferred, in the fixing nip portion M, from the surface of the film 33 onto a surface (image non-recording surface) of the recording material P, at the side of the film 33 , having a temperature lower than that of the film 33 , and is discharged together with the recording material P. Thus, the cleaning mode (control mode) of the present embodiment allows to discharge the toner, deposited in the heater 26 , together with the recording material P at the printing operation.
[0095] 6) Evaluation
[0096] In order to investigate the relationship between the controlled temperature T 2 for cleaning and the cleaning performance, an intermittent sheet-passing durability test (2 sheet/minute) was conducted, Also the rotation (reciprocating rotation) of the fixing roller 20 after the post-rotation step in the image forming apparatus was executed by rotating the fixing roller 20 by 360°, then reversing the fixing roller 20 by 360°, and executing these operations in two cycles. This evaluation employed a monochromatic crushed toner with a fusing temperature of 90 to 100° C. As the recording material, there were employed paper sheets having a relatively rough surface (rough paper) of a letter size, with a basis weight of 90 g/m 2 . In order to achieve satisfactory fixation on this recording material with a process speed of 250 mm/sec, it: was necessary to maintain the fixing nip portion M at a temperature of 180° C., corresponding to a heater temperature of 230° C. Thus the heater 26 at the printing operation (image heating operation) was set at a set temperature (controlled temperature) T 1 of 230° C., and such temperature setting maintains the fixing nip portion M at a temperature of about 180° C. in the printing operation.
[0097] Results are shown in Table 1.
TABLE 1 Control no temperature cleaning 100° C. 150° C. 200° C. Image caused caused not caused not caused defect after after after after 2,000 5,000 20,000 20,000 sheets sheets sheets sheets
[0098] In case the cleaning was not executed, an image defect where the accumulated toner was deposited on the image side of the recording material was caused after printing on 2,000 sheets. When the cleaning temperature T 2 was set at 100° C., the image defect was caused after printing on 5,000 sheets. When the cleaning temperature T 2 was set at 150° C. or 200° C., the image defect was not caused even after printing on 20,000 sheets. It was therefore identified that the number of prints until the generation of the image defect could be increased by executing the aforementioned cleaning mode with a temperature T 2 set at least at the fusing temperature of the toner (100° C.). It was also possible, by setting the cleaning temperature T 2 at 150° C. or higher, to effectively prevent the generation of the image defect and to effectively discharge the offset toner, deposited on the heater surface, by the transfer onto the image non-forming side of the recording material.
[0099] The cleaning sequence of the present embodiment allows to effectively decrease the amount of the offset toner sticking to the heater, even in the presence of fluctuations for example in the roughness of the surfacial coating on the heater 26 , thereby dispensing with an unnecessary precision on the surface coating of the heater to enable an improvement in the production yield of the heater and a cost reduction therein.
[0100] The control mode of the present embodiment is not limited to after the post-rotation step but may also be executed for example after the pre multi-rotation step, the stand-by state or the initial rotation step shown in FIG. 2 .
Embodiment 2
[0101] In the following, there will be explained a second embodiment of the present invention. In the configuration of the entire image forming apparatus and the configuration of the heat fixing apparatus in the present embodiment, components same as those in the foregoing first embodiment will be represented by same numbers and will not be explained further.
[0102] In the present embodiment, in case of a continuous printing operation, the aforementioned control mode is executed after a printing operation of a certain number of sheets. The cleaning sequence after the printing operation, shown in the embodiment 1, cannot be executed during a continuous printing operation, so that the offset toners t′, t″ are accumulated on the heater 26 . Therefore, in a continuous printing operation, the sheet feeding is interrupted and the heater is cleaned when the number of sheets exceeds a certain number.
[0103] 1) Operation Sequence of Printer
[0104] FIG. 8 is a view showing an operation sequence of the image forming apparatus; FIG. 9 is a schematic view showing the configuration of the heat-fixing apparatus; and FIG. 10 is a schematic view showing a temperature control for the heater 26 in case of executing the control mode, a temperature behavior of the heater 26 , and a rotation control of the fixing roller 20 .
[0105] In the present embodiment, the cleaning sequence is executed during a continuous printing operation. Referring to FIG. 9 , a print number counter 38 counts a print number and sends it to a controller 37 . The controller 37 accumulates the print number signal received from the print-number counter 38 , and, when the cumulative number reaches a predetermined number for executing the cleaning, causes the rotation controller 36 to turn off the main motor 35 and the temperature controller 34 to t urn off the current supply to the heat-generating resistor layer of the heater 26 , whereby the heater 26 is cooled.
[0106] Then, when the temperature detected by the temperature detector 27 becomes equal to the set heater temperature T 2 for the cleaning mode, the controller 37 causes the temperature controller 34 to turn on the current supply to the heat-generating resistor layer of the heater 26 , thereby maintaining the temperature T 2 capable of fusing the toners t′, t″ deposited in the heating nit portion N. In this state, each toner is combined. Also, simultaneous with the turning-on of the current supply to the heat-generating resistor layer of the heater 26 , the rotation controller 36 turns on and off the main motor 35 alternately clockwise (reverse direction in FIG. 6 ) and counterclockwise (forward direction in FIG. 6 ), thereby causing two cycles of reciprocating rotation in the fixing roller 20 . In this operation, as explained in the foregoing, the toners t′, t″ supported on the fixing roller 20 are brought to the fixing nip portion M and are transferred therein onto the surface of the pressure member 30 of a temperature lower than that of the fixing roller 20 .
[0107] Then the rotation controller 36 turns off the main motor 35 and, at the same time, the temperature controller 34 turns off the current supply to the heat-generating resistor layer of the heater 26 , whereby the control mode is terminated.
[0108] Upon completion of the control mode, the image forming apparatus restarts the image forming operation.
[0109] 2) Evaluation
[0110] In order to investigate the relationship between the timing for executing the cleaning sequence and the cleaning performance, a continuous sheet-passing durability test was conducted. Continuous sheet passing was conducted with 1,500 sheets per job, and the set control temperature T 2 was maintained same as the temperature T 1 in the printing operation. Results are shown in Table 2.
TABLE 2 Timing of every 500 every 250 cleaning none sheets sheets Image defect caused after caused after not caused 1,000 sheet 2,000 sheets after 20,000 sheets
[0111] In the continuous printing operation, the image defect was caused after 1,000 prints when no cleaning was conducted. In case of executing a cleaning operation for every 500 prints, the image defect was caused after 3,000 prints, but the number of prints prior to the generation of the image defect was made much larger. Also a cleaning operation for every 250 prints could effectively prevent the image defect. Thus, the offset toner, deposited on the heater surface, can be effectively removed by executing the reciprocating rotation of the fixing roller in the course of the continuous printing operation.
1) In the embodiments 1 and 2, there has been explained an example of executing two reciprocating cycles of the fixing roller 20 , but such reciprocating rotation of the fixing roller 20 may be executed in one cycle or in three or more cycles. 2) The image heating apparatus of the present invention is applicable, not only to the heat fixing apparatus shown in the embodiments but also to various means or apparatus for heating a recording material bearing an image, such as an image heating apparatus for improving a surface property such as gloss by heating the recording material P bearing an image, or an image heating apparatus for temporary image fixation. 3) For forming an unfixed toner image on the recording material P, there can be employed any image forming process such as an electrophotographic process or an electrostatic recording process of direct type or indirect type.
[0115] The present invention is not limited to the aforementioned embodiments but is subject to any and all modifications within the technical concept thereof.
[0116] This application claims priority from Japanese Patent Application Nos. 2004-026239 filed Feb. 3, 2004 and 2005-011711 filed Jan. 19, 2005 which are hereby incorporated by reference herein.
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The image heating apparatus for heating a toner image formed on a recording material, comprising, a rotatable member; heating device for heating an outer peripheral surface of the rotatable member, the heating device including a heater for forming a heating nip portion in cooperation with the rotatable member; back-up device for forming a conveying nip portion in cooperation with the rotatable member, the conveying nip portion conveying the recording material; and control device for controlling a temperature of the heater and a rotation of the rotatable member, wherein the apparatus has a cleaning mode to remove toner from the heating device, and the control device rotates or reversely rotates the rotatable member in a condition that the heater dissipates heat in the cleaning mode. By the virtue of the present invention, it prevents stain caused by the off-set of toner the recording material in an image heating apparatus.
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FIELD OF THE INVENTION
[0001] The present invention relates to the field of cashless transaction processing systems. More specifically, systems and methods are disclosed that provide, ensure, and maintain the security of financial transactions conducted with a credit card, electronic wallet, or other cashless payment mechanism at a vending machine or retail point of sale.
BACKGROUND OF THE INVENTION
[0002] The acceptance of cashless payments, such as credit, debit, pre-paid cards and mobile near field communication (NFC) payment readers, in unattended vending situations is becoming common. The first widespread use of unattended cashless payment systems was with gas pumps at filling stations. Other unattended vending situations include carwash facilities, roadside truck weigh scales, public massage chairs, and video rental kiosks, among others. More recently, cashless payments are used in commodity vending machines such as food, bottled water, toiletries, etc.
[0003] The unattended vending situations described herein generally involve low cost items, typically priced under $20.00. However, there are also unattended vending machines deployed utilizing cashless payments that vend higher valued items such as digital music players, DVD players, headphones, phone chargers, digital cameras, portable gaming devices, flash drives, gift cards, etc.
[0004] By their very nature of being unattended, cashless payment transactions are susceptible to fraud or security breaches. A vending machine may be in an isolated area with no one watching and may be susceptible to tampering, modification, or other unintended and unauthorized manipulation. Even when the equipment is in a public area a person could access and tamper with vending equipment by posing as service personnel.
[0005] One of the key fraud problems involves the theft of account information from a credit card or other cashless payment mechanism. There are at least five ways to steal or skim account numbers from existing vending systems: (1) Internal Skimming Device that is attached internally in the equipment to electrically collect account numbers from the data stream; (2) External Skimming Device that electrically collects account numbers from the data stream exiting the cashless payment device going to the payment processor; (3) Detection of RF Energy that is emitted from a legitimate reader/processor device as the account number data travels internally through the equipment; (4) Hardware/Software Hacking of the actual card reader; and/or (5) False Front Device that is attached over the actual card reader to capture data from a magnetic stripe card as it is entering the “real” card reader and can sometimes also include nearby hidden cameras to capture entry of PIN data associated with the cashless payment mechanism.
[0006] One potential approach to at least some of the skimming type of security problems is to encrypt the account information. Currently, there are some solutions available that can encrypt the account numbers within an encryption engine at or near the card reader read head. MagTek and others, for example, provide a card reader with a proprietary encryption engine encapsulated within the read head. However, these solutions are inadequate or have disadvantages that are barriers to effective application of this approach in electronic cashless payment systems because the entire card image is either encrypted such that the local controller cannot get access to portions of the data that may not need to be secured as robustly as account information, such as the expiration date, BIN number, and service code, or such information is left completely unsecured and can still be attacked by a skimming fraud.
[0007] The other kinds of fraud besides skimming are often referred to as a “Trojan Horse” type of fraud based on either hacked hardware or software or on a false front for the vending machine card reader. Approaches for defeating this kind of fraud rely on mechanical/electrical security in the form of locks or passwords on the card reader hardware/software, or on a detection of a false front on the vending machine. A number of schemes for detecting a false front have been proposed. One scheme uses infrared light paths that can detect when material has been added to the front of the reader. Another scheme uses a metal sensor to detect additional electronics has been added to the front. If a false front is detected the ATM machine would be shut down causing the display to go blank, hopefully discouraging a user from attempting to use the card reader. The following patents describe prior attempts to implement false front detecting systems: U.S. Pat. Nos. 7,602,909 to Shields, 6,422,475 to May, and 6,367,695 to Mair.
[0008] Once a person has obtained a stolen payment media, or created one using skimmed account numbers, financial fraud is difficult to stop. A stolen or skimmed account number can be easily used at an unattended electronic cashless payment system since there is no personnel available to check for an identification or to verify a signature to ensure that the person holding the card or payment media is the account holder. As a result, this type of fraud represents a significant loss to merchants an there is need for a secure solution to skimming and Trojan Horse fraud for cashless payment systems for such unattended vending machines and the like.
SUMMARY OF THE INVENTION
[0009] Embodiments of the invention described herein include an electronic cashless payment system that is flexible such that it can be used in a wide variety of vending equipment, including computer-controlled equipment. Embodiments of the invention can provide a desired level of security appropriate for various financial transaction applications. Any payment type such as credit, debit, pre-paid cards, and mobile NFC payment readers can be included in embodiments of this invention. Alternate embodiments can include attended point of sale (POS) terminals that include electronic cashless payment transaction features. For example, an embodiment of the invention can include a credit card POS device on the counter of a retail store checkout lane.
[0010] The use of the term card reader can include any device that can read a personal payment media, including but not limited to, magnetic stripe cards, contactless payment cards, NFC devices, mobile or cellular devices, and smartcards. Various embodiments of the present invention can provide the following features:
Provide a secure, workable, and flexible cashless payment system that can be used in conjunction with a wide variety of unattended payment equipment. Provide a secure cashless payment system that can be easily integrated into existing payment equipment. Provide a secure cashless payment system that can be used with an embedded or personal computer. Provide a secure cashless payment system that can resist internal skimming. Provide a secure cashless payment system that can resist external, false front, skimming. Provide a secure cashless payment system that can detect and indicate that a card reader component has been tampered with or replaced. Provide a secure cashless payment system that can detect and generate an alarm if a card reader component is tampered with or replaced. Provide a cashless payment system that is resistant to the use of counterfeit or fraudulently obtained account numbers. Provide for the detection of tampering or attacks on the cashless payment system through a worldwide electronic network alert. Provide for backup, communication capabilities, supplying an improved fail-safe detection and reporting mechanism.
[0021] In an embodiment of the invention, account data received at a card reader is encrypted at a read head that first receives the account data and maintains the data in an encrypted form along the entire path to an authorized financial transaction server. This end-to-end encryption can include embodiments of the Secure Sockets Layer (SSL)/Transport Layer Security (TLS) encryption scheme similar to the encryption techniques used to send on-line payment transactions to secure website payment servers. End-to-end encryption technologies other than SSL/TLS can also be included in various embodiments of the device. End-to-end encryption can eliminate the need to include systems that must go to an intermediate server to decrypt some or all of the account data, and then re-encrypt the data using an encryption scheme required by the transaction processor.
[0022] In an embodiment, card data that includes account information can be provided to the Network Access Controller before requesting that the read head send the fully encrypted data to the transaction server. This step allows the Network Access Controller to make certain preliminary decisions at the Network Access controller, such as determining the type of transaction or account type that is being presented and verifying that the presented card data can be processed by the system.
[0023] In an embodiment, a Payment Security Display Module (PSDM) is included as an additional device that can detect if the card reader has be replaced or temporarily removed from a system. This detection can indicate that the system has possibly been modified by an unauthorized individual, or that Trojan Horse mechanism could have been installed that would compromise the security of the system.
[0024] In an embodiment, a swipe reader assembly or an insertion reader assembly can provide resistance to the addition of skimming devices or other false front card readers by including blocking features or arranging the reader and other components to discourage or prevent the attachment of a skimming device.
[0025] In an embodiment, a monitoring server can be configured to receive alarm messages from a cashless payment system. The connection between the server and the cashless payment system provides a positive feedback loop to the entitled parties, which can provide immediate detection of tampering to the unattended cashless system. The monitoring server can also provide an interface to configure and enable alarm features, additional security configurations, and special instructions to one or more unattended payment systems or devices.
[0026] In an embodiment of the invention, an encapsulated reader device includes a read head that is configured to provide preliminary data to a network access controller. The read head is further configured to encrypt received card data and utilize SSL encryption to authenticate a transaction-processing host, negotiate encryption keys with the transaction-processing host, and send the encrypted transaction, including the encrypted card data from the read head to the transaction processing host.
[0027] In an embodiment, the read head includes a serial number that is unique to each read head device. The network access controller can check the serial number of the read head device before every transaction to determine if it has been changed, thereby eliminating the possibly that the read head device has been compromised due to tampering or unauthorized replacement.
[0028] In an embodiment, a secure reader for use with a cashless transaction system in an unattended vending machine includes a network access controller coupled over a network to a financial transaction processing server. The secure reader includes a read head configured to read financial account data from a cashless transaction device presented by a user, a display configured to present payment status information to the user, a tamper detector configured to detect tampering with the secure reader, and a microcontroller securely coupled to the read head, the display, the tamper detector and the network access controller. The microcontroller can be configured to present warning information to the user via the display in response to the tamper detector, transmit transaction information other than account information from the data from the cashless transaction device for use by the network access controller to initiate a financial transaction with the financial transaction processing server, and, in response to an encryption key provided by the financial transaction processing server for the financial transaction, encrypt financial information that includes the account information from the data from the cashless transaction device for secure communication without decryption by the network access controller to the financial transaction processing server.
[0029] The above summary of the invention is not intended to describe each illustrated embodiment or every implementation of the present invention. The figures and the detailed description that follow more particularly exemplify these embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] The embodiments of the present invention may be more completely understood in consideration of the following detailed description of various embodiments in connection with the accompanying drawings, in which:
[0031] FIG. 1 is a block diagram of a typical cashless transaction system.
[0032] FIG. 2 is a block diagram of an exemplary secure electronic payment network according to an embodiment of the present invention.
[0033] FIG. 3 is a block diagram of an exemplary payment security display module according to an embodiment of the present invention.
[0034] FIG. 4 is a block diagram of an exemplary magnetic read head assembly according to an embodiment of the present invention.
[0035] FIG. 5 is a block diagram of an exemplary contact-less read head assembly according to an embodiment of the present invention.
[0036] FIG. 6 is a block diagram of an exemplary secure electronic payment system assembly according to an embodiment of the present invention.
[0037] FIG. 7 is a diagram of an exemplary electronic cashless payment system with a non-encapsulated read head.
[0038] FIG. 8 is a diagram of an exemplary electronic cashless payment system with an encapsulated encrypting read head.
[0039] FIG. 9 depicts an exemplary data record that can include masked card data.
[0040] FIG. 10 depicts a communication handshaking sequence between a cashless payment system and a secure payment server.
[0041] FIG. 11 depicts an exemplary embodiment of a false-front resistant insertion card reader.
[0042] FIGS. 12A & 12B depict an exemplary embodiment of a false-front resistant swipe card reader.
[0043] While the present invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the present invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention.
DETAILED DESCRIPTION
[0044] One of the key fraud problems involves the theft of account information from a credit card or other cashless payment mechanism. There are several ways to steal or skim account numbers from existing systems:
Internal Skimming Devices—Attachment of a device internally in the vending equipment can electrically collect account numbers from the transaction data stream. The account numbers can be wirelessly transmitted from the internal skimming device or the device can be retrieved for later collection of the data. External Data Skimming—Attachment of a device to electrically collect account numbers from the data stream exiting the cashless payment device going to the payment processor. Detection of emitted RF Energy—Legitimate device equipment can emit signals that external receivers can theoretically detect and decode to access the account number information due to the RF energy emitted as the account number data travels internally through the equipment. False Front—Attachment of a skimming device, such as a false front, over a legitimate card reader can allow the capture data from a magnetic-stripe card as it is entering the legitimate card reader. An external skimming device that does not interfere with the legitimate reader may be able to capture stolen data while still allowing the legitimate transaction to occur.
Internal Skimming Devices
[0049] FIG. 1 shows various locations where an internal skimming device can be connected to collect account numbers from the data stream within an electronic payment system 10 .
[0050] Account numbers can be captured by electrically connecting a skimming device to the data wires 12 between a card reader 14 and the vending machine controller 20 . The skimming device can then either store the captured account numbers, or transmit the account numbers to a nearby receiver. This is especially easy to accomplish when the card reader 14 is mounted on a machine panel and communicates with the controller 20 via a data cable. For example, a vending machine that has a magnetic stripe or contact-less card reader 14 mounted on a panel and it has a short cable connecting the reader to a computer or other controller 20 housed in the machine is susceptible to skimming in this manner. A common RS-232 card reader that attaches to a computer with serial RS-232 communication software can transmit account information as printable characters that are easily copied, saved, or retransmitted to an unintended third party.
[0051] If a cashless payment system requires the entry of PIN numbers, this skimming scheme is often accompanied either with the placement of a camera for capturing the PIN number as it is entered. In a more sophisticated system, a device can be internally attached within the PIN pad 22 for capturing and storing or transmitting the PIN numbers for each card used.
[0052] Encrypting the account information can limit the success of internal skimming. Currently there are solutions available that can encrypt the account numbers within an encryption engine at or near the card reader read head. MagTek Inc., of Seal Beach, Calif., and others, for example provide a card reader with the encryption engine encapsulated within the read head.
[0053] These solutions also present barriers to their application in electronic cashless payment systems. Various current proposed solutions present undesirable situations as follows:
1. The entire card image is encrypted such that the local controller 20 cannot get access to portions of the data that do not need to be secure. The local controller 20 , which may include a network access device, requires access to the following information:
Expiration date. So that the controller 20 can reject expired cards without having to submit the card to a transaction processor 30 resulting in an authorization fee charged to the merchant. The expiration date does not need to be encrypted in order to comply with current standards. BIN number. The BIN number is the first six digits of an account number. The controller 20 needs to have access to the BIN number so that it can determine if the card is of a type that can be accepted. (e.g., VISA, MASTERCARD, DISCOVER, etc.) Without this information the controller 20 cannot locally reject card types that cannot be accepted thus unnecessarily incur an authorization fee charge. Service Code. The Service code provides information about whether the account number can be used outside the country of origin and also information about whether this account requires a PIN code entry. Again having this information locally can save the expense of incurring an authorization charge.
2. Existing solutions allow portions of the data to be left completely clear so that the local controller 20 can have access to those fields use their own encryption scheme. However, these encryption solutions use an encryption scheme that requires special software at the transaction host 30 or they require an intermediary server to decrypt the transaction and re-encrypt it using the encryption scheme utilized by the final transaction server. This exposure at the intermediate server is a point of vulnerability. 3. Those solutions that allow portions of the data to be left completely clear for the local controller 20 can still be providing information that is best kept secret such as the card BIN number (first 6 digits) and the expiration date. It is less secure to have that data completely exposed.
External Data Stream Skimming
[0060] It has been possible in some systems to collect account numbers from the data stream 28 leaving the cashless payment device 10 going to the payment processor 30 through public networks such as Ethernet or telephone service. While this is rare at this time, it can be achieved by connecting a cable that routes data to these public networks.
External Detection of RF Energy
[0061] In some unattended cashless payment situations the card reader or mobile NFC mechanism is located some distance from the cashless payment device 10 . It is possible that the data cable 12 connecting the card reader 14 to the controller 20 can emit RF energy that can be detected and decoded by a device with a nearby antenna.
False Front Skimming
[0062] Account numbers can be skimmed by placing a false front over the magnetic stripe card reader 14 of a machine. This can be done without gaining access to the inside of the equipment. A false front reads the magnetic card before the customer's card enters the proper card reading mechanism 14 . This false front has either an electronic storage device or a transmitter so that the account numbers can be captured. This scheme is often accompanied with a camera for capturing the account numbers or a PIN.
[0063] A number of schemes for detecting a false front have been proposed. One scheme uses infrared light paths that can detect when material has been added to the front of the reader 10 . Another scheme uses a metal sensor to detect additional electronics has been added to the front of the device 10 . If a false front is detected the ATM machine would be shut down causing the display to go blank, hopefully discouraging a user from attempting to use the card reader 14 . The following patents that describe previous attempts to implement false front detecting systems: U.S. Pat. Nos. 7,602,909 to Shields, 6,422,475 to May, and 6,367,695 to Mair. These systems are not without limitations.
“Trojan Horse” Attacks
[0064] Trojan Horse attacks generally refer to attacks on account numbers. There are two types of “Trojan Horse” attacks: Trojan Horse Hardware involves swapping out the card reader equipment 14 with what appears to be identical card reading equipment and Trojan Horse Software, where the software 32 within the controller 20 is replaced or modified so that an additional function of storing or transmitting account numbers is added.
[0065] In a hardware attack, the actual card reader 14 used in a vending machine is replaced with an identical-looking device (“Trojan Horse”) that captures card numbers. The replacement does not necessarily have to function properly. When this replacement has occurred a user will present a credit card for payment to the replacement device. Even if the vending machine does not operate the account number will have been captured. It could be possible for dozens or hundreds of card numbers to be captured before the fraudulent replacement is detected. The Trojan Horse device may be swapped back with the original device 14 before authorized service personnel get called out to inspect the machine.
[0066] Existing solutions generally consist of being careful that the equipment is secured with mechanical locks where only trusted and authorized personnel have access to the components within the equipment. This is not always very secure however, as people can pose as service personnel to request or duplicate the required keys, and gain access. Mechanical locks are also susceptible to being compromised by picking the lock.
[0067] When a cashless payment system uses a PC computer running a common operating system such as Microsoft Windows, it is possible for a person to replace components of the operating software or system software 32 with “Trojan Horse” software that can capture account numbers from the data coming from the equipment card reader 14 . This Trojan Horse software can capture account numbers even when the data from the card reader is encrypted as the operating system or software 32 often must decrypt the data in order to do its processing before sending the information on to the processing host. Electronic cashless payment systems 10 that use computer systems running public operating systems such as Microsoft Windows are especially vulnerable to software attacks such as a software Trojan Horse.
[0068] These are similar to the types of virus, worms, malware, and Trojan Horses that plague the software industry. Such public attacks often occur while connected to the Internet. Though an electronic cashless payment system is not typically browsing the Internet, it is still connected to a public network and could experience a similar attack. Furthermore, such systems often have some sort of input device, such as a USB port, a CD-ROM/DVD reader, or a removable disk drive, for loading software updates. Such a device can be used for injecting malicious software that can be used to skim account numbers.
Use of Fraudulent Account Numbers
[0069] Once a person has obtained a stolen payment media, or created one using skimmed account numbers financial fraud is difficult to stop. A stolen or skimmed account number can be easily used at an unattended electronic cashless payment system since there are no personnel available to check for identification or to verify a signature to ensure that the person holding the card or payment media is the account holder. This type of fraud represents a significant loss to merchants and illustrates the need a secure solution.
[0070] When an account number has been stolen, the immediate use of that account can cause severe problems and financial loss. With the utilization of embodiments of invention as disclosed herein, the opportunity to utilize stolen account numbers at the unattended cashless payment system is reduced and thus a reduction in fraud can be accomplished. An embodiment of a secure payment system can present the entire card track image to a transaction processor, qualifying the transaction for card present transaction rates. The addition of a keypad and an interface to present instructions, requesting the customer to enter a zip code or similar customer identifying details, the transactions can qualify for a lower transaction rate.
Secure Payment System
[0071] Various embodiments of the present invention address attacks on card readers and vending devices, and work to prevent the proliferation and illegal use of stolen account numbers. Embodiments of an exemplary encryption security mechanism included in magnetic card readers or NFC readers can reduce the likelihood of successful attacks on payment processors and payment networks.
[0072] FIG. 2 depicts an example secure payment system and financial transaction network. The network access controller 100 manages communication between the vending machine controller 110 , a customer payment input device 102 , and a payment transaction processor 106 . The network access controller 100 can be enabled to accept cashless payment by the vending machine controller 110 . A vending machine controller 110 can inform the network access controller 100 of the payment amount when a user selects an offered product for purchase.
Network Access Controller
[0073] The network access controller 100 can receive payment information from the customer payment input device 102 . The network access controller 100 can determine if a presented payment input is valid by checking account type and expiration date or send an appropriate message about the payment status (e.g., expired card, invalid card type, etc.) to the payment security display module 113 . If the payment input is valid, the Network access controller 100 creates a protocol communication packet appropriate for the particular banking system transaction-processor or server 106 .
[0074] The network access controller 100 can contain a CPU or micro-controller, volatile memory, non-volatile computer readable storage, and several interfaces to other components. Network access controller 100 can configured to receive and decrypt preliminary data from the secure payment input device 102 such as a magnetic stripe card reader, a contact-less reader, or both. This data can be received via connection 104 .
[0075] The connection between the Network access controller 100 and the vending machine controller 110 , or other embedded computer, can allow a communication channel to be established with the transaction processor 106 for maintenance, logging, or reporting functionality. The transaction processor 106 can send control messages to the vending equipment controller 110 via the connection between the network access controller 100 and the vending machine controller 110 .
[0076] The network access controller 100 can communicate with the payment security display module 112 to send display messages (e.g., “Please insert card”, Expired card”, etc.). The Network access controller 100 can also communicate with the payment security display module 112 to detect tampering and to cause the “Safe” light 116 or “Warning” light 118 to be illuminated.
Payment Security Display Module
[0077] Referring to FIG. 3 , an exemplary payment security display-module 112 can include a relatively small display 113 placed on the exterior of the vending machine in a location visible to the user. The payment security display-module 112 can monitor the security of the electronic cashless payment system and display the status of the security via a lighted “Safe” indicator 116 or “Warning” indicator 118 . The payment security display module 112 can also display other useful messages to the customer about the state of the payment system. These messages can be status messages as “Please insert card”, “Expired card”, “Machine out of Order”, etc.
[0078] An exemplary payment security display module 112 can monitor the following conditions within the system:
It can detect that the connection 120 to the secure card reader 102 has been disturbed. As an example this could be either an electrical continuity detection circuit that detects the cable has been disconnected or it can be a mechanism for detecting that the connection 104 between the card reader 102 and the network access controller 100 has been disturbed. It can detect that its connection 114 to the network access controller 100 has been disturbed. It can detect that the serial number in the card reader 102 has changed from when it was last configured. It can detect though a tamper detecting switch 122 that it has been moved.
The payment security display module 112 can provide indications including:
A display indicator to present payment acceptance messages such as “Insert Card”, “Expired card”, “Card declined”, etc. A display indicator to present the Electronic Cashless Payment System security status. It can show, for example, either the “Safe” or the “Warning” light.
[0085] The Payment Security Display Module 112 can communicate an alarm to the Remote Monitoring Server 124 , through at least one of the following mechanisms:
The wired-connection to the Network access controller 100 the provides a communication link to the server 124 . A wireless, or other public network connection, to the Monitoring Server via a separate communication module 126 .
[0088] The monitoring server 124 can be configured to receive alarm messages from the network access controller 100 or payment security display module 112 . It can then relay this message to service personnel via email or cell phone text message. This monitoring server 124 can also provide an interface to configure and enable alarm features, additional security configurations, and special instructions to the unattended payment.
Security Features
[0089] Interruption of Connection Tampering Detection
[0090] Referring to FIG. 2 , if any of the interconnecting data cables ( 104 , 114 , 120 ) are briefly disconnected, any one, or all, of the following can occur in response:
The “Warning” light 118 or the display 113 on the payment security display module 112 can indicate an unsafe alert to the unsuspecting cashless payment user. A payment security display module 112 can include a rechargeable battery 128 that can keep the “Warning” system working for an extended period. In one embodiment a two-day warning indication can be provided. The warning indication or message can therefore be displayed even if the vend system has lost power. If the firmware in the network access controller 100 detects that a connection 104 has been broken, or if the payment security display module 112 detects a broken connection 104 between to the card reader 102 the Network access controller 100 can attempt to send a warning message to the payment security display module via link 114 . If the firmware in the Network access controller 100 has detected that the serial number in the payment security display module 112 , or the serial number in the card reader 102 is not what was configured, it can attempt to send a warning message to the payment security display module 112 . If the firmware in the network access controller 100 has detected a broken connection 114 due to the fact that it cannot communicate with the payment security display module 112 , or has detected a serial number change in either the module 112 or the card reader 102 , it can attempt to send an alarm message to the monitoring server 124 . The payment security display module 112 can be configured with an remote communications module 126 . This module 126 , when tampering is detected, can send an alarm message to the remote monitoring server 124 , or any other server, via its own connection to the wireless cell phone network, the interne 108 , or any other network. This module 126 can include a rechargeable battery so that it can send the message even if power is disconnected.
[0096] The security system shown in FIG. 2 can include a monitored connection 103 to the optional PIN pad 101 so that tampering with the PIN pad 101 can be detected and reported by the payment security display module 112 . When the payment security display-module 112 goes into warning mode, and when the system is first configured for operation, a service person can use the payment-monitoring server 124 to configure the payment security module 112 for normal operation.
Detection of Serial Number Change Tampering
[0097] The preliminary data coming from the read head assembly 102 to the network access controller 100 can be encrypted with the card reader serial number. If the network access controller 100 detects that the serial number of the secure card reader 102 has changed, it can generate an alarm (tell the security module to show “Warning” indication 118 or other message). The network access controller 100 can stop accepting payments, send an alarm to the monitoring host, and it can also notify the vending machine controller 110 , if configured, of the situation.
[0098] If the network access controller 100 detects that the serial number of the secure payment display module 112 has changed it will send an alarm to the monitoring host, it will stop accepting payments and it will also notify the vending machine controller 110 , if capable, of the situation.
End-to-End Encryption
[0099] As depicted in FIGS. 4-5 and 8 , a secure card reader 200 with a secure encapsulated encrypting read head 202 can be a magnetic stripe card reader, a contact-less card reader, a mobile phone NFC reader or any combination. A secure card reader 200 can have a built-in Cryptographic Service Provider (CSP). Card reader 200 can negotiate authentication and encryption directly with a transaction host (through a secure pass-through in the Network access controller 100 , using the Network access controller Network transport Layer (NTL)) and then send the transaction through the Network access controller directly to the Transaction processor.
[0100] The flow chart depicted in FIG. 8 shows an embodiment where only preliminary data is presented to the network access controller 100 as the first step in the process initiated by the secure card reader 200 . Network access controller 100 can construct a communication packet for the appropriate, configured transaction processor 106 , request that the secure card reader 200 encrypt a communication packet for the transaction processor 106 . Network access controller 100 can receive the reader-encrypted packet and pass it on directly to the transaction processor 106 , thereby maintaining the secrecy of the account data between the reader 200 and the transaction processor 106 .
[0101] One example of this transaction is depicted in FIG. 8 where the Cryptographic Proxy can send the protocol packet to the Cryptographic Service Provider (CSP) in the card reader 200 . The Read Head assembly and then the Cryptographic Proxy receives the encrypted response and passes it directly to the transaction processor through the Network Transport Layer (NTL).
[0102] The Network access controller 100 sends the communication packet to the secure card reader and asks it to negotiate authentication and encryption with the banking system transaction processor. When the Network access controller 100 has been information by the banking system transaction processor that the payment is finalized it notifies the Vending Machine Controller 110 that it is OK to vend the product.
[0103] If at any time the electrical connection 114 between the payment security display module (PSDM) 112 and the secure card reader or the network access controller 100 is broken the PSDM 112 will enter warning mode and will display a “warning” message and will attempt to send an alarm message to the monitoring server through the network access controller 100 .
[0104] If at any time the data communication between the PSDM 112 and the secure card reader 200 or the network access controller 100 is broken the PSDM 112 will enter warning mode and will display a “warning” message and will attempt to send an alarm message to the monitoring server through the network access controller 100 . If the PSDM 112 has entered warning mode and cannot communicate with the network access controller 100 to send out an alarm message, and if the PSDM 112 includes a communication device 126 it will attempt to send out the alarm through the communication device 126 .
[0105] The PSDM 112 can have a backup battery 128 that has its charge maintained while connected normally to the network access controller 100 so that if the connection is electrically broken or if the vending machine has had its power removed the PSDM 112 can still illuminate the warning indication 118 for a period of time. The optional PSDM communication device 126 also can include a backup battery 129 that has its charge maintained while the PSDM 112 connected normally to the network access controller 100 so that if the connection is electrically broken or if the vending machine has had its power removed the PSDM communication device 126 can still function long enough to send out the alarm message.
[0106] Referring to FIGS. 4 and 5 , the card image data, from magnetic stripe, contact-less cards, and NFC mobile phones, can be encrypted within an encapsulated read head ( 202 , 203 ). The electronics, including the signal detector 204 , a micro-controller 206 , program storage memory, data memory, and non-volatile memory are encapsulated within the read head module 200 with epoxy or other tamper resistant material.
[0107] Other solutions that encapsulate such devices with in the magnetic stripe read head are available from card reader supplies such as MagTek Inc., of Seal Beach, Calif. However, the current solutions have specific encryption algorithms that either require the local network access controller to open the encryption and then re-encrypt it using the encryption supported by the transaction server or they require first sending the card image to an intermediate server which then decrypts the information before passing it on to the final processing server.
[0108] An embodiment of the invention includes an encryption engine built-in to the read head that negotiates the encryption directly with the final processing server using a commonly implemented and understood client/server authentication and encryption negotiation scheme known as Secure Socket Layer version 3 (SSLv3) (1995) and Transport Layer Security (TLS) (Internet Engineering Task Force (IETF) 1997-1999).
[0109] A block diagram of the components embedded within the magnetic read head 202 are shown in FIG. 4 . A block diagram of the components embedded within the contact-less read head 203 are shown in FIG. 5 . Embodiments of secure card reader 200 can include one or both types of read head devices. Along with the detector circuit ( 204 , 205 ), a single chip micro-controller 206 can be embedded within the reader 200 . This micro-controller 206 can be programmed to decode the data stream from a payment card presented to the read head ( 202 , 203 ). The micro-controller 206 can include Cryptographic Service Provider (CSP) functions, and be configured to negotiate SSL/TLS handshaking directly with a secure server 106 over a network 108 . The micro-controller 206 can also include non-volatile computer readable storage for storing the SSL Certificates of Authority that can be used in the SSL/TLS negotiation.
[0110] FIG. 7 shows how SSL/TLS can be implemented in an existing electronic cashless payment system. An existing card reader 250 that does not encrypt data, or transmits in the clear, between the card reading mechanism 250 and a network access controller 100 . The network access controller 100 can analyze the card data, determine if a correct card format has been presented to the reading mechanism 250 , determine if the card has expired, determine the card type, build a protocol packet, encrypt the account data with a CSP, and finally transport the encrypted packet to a payment processor or server 106 .
[0111] FIG. 8 shows an example embodiment of a secure electronic cashless payment system. In FIG. 8 , the Cryptographic Service Provider of FIG. 7 has been replaced with a Cryptographic Proxy and the Cryptographic Service Provider is encapsulated in the Secure Encapsulated Read Head Assembly 200 .
[0112] In FIG. 8 it is seen that when a user presents payment, the secure encapsulated read head assembly 200 first presents preliminary data to the network access controller 100 so that decisions can be made about expiration date, card type, and whether the reader 200 is secure (from the checksum and serial number included). This preliminary data includes portions of the data that are required to make the described decisions along with the secure reader serial number and operating firmware checksum. When the network access controller 100 has determined that the payment is acceptable, it forms the appropriate transaction packet and sends it to the Cryptographic Service Provider in the secure read head assembly 200 for encryption.
[0113] The encapsulated secure read head assembly 200 can have a connection to the network access controller 100 . This first provides the read head assembly 200 with the capacity to send encrypted preliminary data for the network access controller 100 to use to make decisions based on card type, expiration date, etc. Also, this preliminary data includes the read head serial number and firmware checksum to be used to verify security. Second, when the network access controller 100 has verified that the payment can be accepted, the controller will format the appropriate transaction package for the transaction processor and send that package to the secure read head assembly 200 to request that it be sent to the transaction processing server 106 . The read head assembly 200 will negotiate authentication with the transaction processor server 106 and send the complete package.
[0114] The encapsulated secure read head assembly 200 can also include a connection to a payment security display-module 112 . The payment security display-module 112 uses this connection to monitor a card reader disconnect event and to monitor the card reader serial number.
Remote Security Server
[0115] Referring again to FIG. 2 , the remote monitoring server 124 , is a secure server. An electronic cashless payment system can communicate with it using SSL/TLS negotiated directly from the network access controller 100 . The remote monitoring server 124 can include the following functions:
Receive alarm messages from the network access controller 100 . If the payment security display module 112 is configured with its own communication channel it can receive alarm messages from the module. Receive periodic check-in reports from configured network access controllers 100 and/or Payment Security Display modules 112 . For additional security, the remote monitoring server 124 can be configured to periodically call out to certain configured Network Access Controllers 100 and/or Payment Security Display Modules 112 to verify operating status. The remote monitoring server 124 can also used by support personnel to access the payment system to configure it and arm or reset the monitoring features. The remote monitoring server 124 can receive sales reports from the each Network Access Controller 100 . These sales reports can be saved as files, sent out as emails, or posted to a website. These reports do not have full account numbers (just last five digits and card type with other information such as sale date, time, and amount).
Preliminary Data Received from Secure Card Reader
[0122] When a payment from a magnetic stripe card, contact-less card, or NFC mobile phone is presented at the secure reader, it will first send preliminary data to the Network Access controller.
[0123] This preliminary data has portions of the data masked off as shown in FIG. 9 . The remaining portions of the data can be used to determine card type, expired cards, cards requiring PIN codes, etc.
[0124] The preliminary data includes the card reader serial number and an MD5-128 checksum of the operating software. Since the preliminary data includes the secure reader serial number and operating software checksum, the preliminary data is encrypted. This encryption keeps the serial number, checksum, and the unmasked data secret. Any one of a number of encryption schemes can be used. Even if this encryption is broken, the account number data is secure since it was masked off.
[0125] FIG. 9 shows the format of the preliminary data. This data is actually encrypted between the secure card reader and the Network Access Controller.
[0126] An example of a client server authentication and encryption negotiation is shown in FIG. 10 . By using SSL/TLS the electronic payment system is secure and can connect with and transmit electronic payment information to any payment process able to securely process credit card payments from Internet web browsers. There is no need for an intermediate server.
[0127] This is true end-to-end encryption since the account data is encrypted within the encapsulated module that first received the account information. It remains encrypted all the way to the transactions processing host without having to be opened by the local controller, or an intermediary server. Since the transaction is never decrypted, this system is immune to software attacks such as viruses, worms, Trojan Horse, malware, etc.
False Front Prevention to Defeat External Skimming
[0128] An Electronic Cashless Payment System that accepts magnetic stripe cards can be configured to utilize a variety of magnetic strip card readers, including insertion readers and swipe readers.
[0129] Insertion Readers are vulnerable to the false front attack. For Example, an identical faceplate with a read head and storage and/or a transmitter can be put over the front of the reader. The read head in the false front captures the account number before the card gets into the proper reader.
[0130] Referring to FIG. 11 , an exemplary embodiment of a false front resistant insertion reader 400 can include a read head 402 on top of the card slot 404 . The card track slopes down to help prevent water from entering or damaging the reader 400 . The downward slope of the card slot 404 and its location directly over the keypad 406 , any sort of false front will be difficult to attach and will be obvious since it will obscure part of the keypad 406 . The insertion reader 400 can be sized to fit in the same cutout used in vending machines for a common bill acceptor, making it possible to remove a bill acceptor and replace it with an embodiment of a cashless payment system insertion reader 400 .
[0131] The insertion reader 400 can include an encrypting magnetic stripe read head 402 and the Network Access Controller features embedded within the Insertion Reader enclosure 412 . In one embodiment, the insertion reader 400 can also include an encrypting contact-less card or mobile NFC read module 408 . Insertion reader 400 can have soft material privacy shield 410 along the sides of the key pad to obstruct viewing of the key pad 406 with intention of harvesting PIN numbers.
[0132] In another embodiment the key pad 406 of the Insertion Reader 400 can include a touch screen LCD display such that it could display vending machine item selection or welcome messages in addition to providing a numeric keypad. The touch screen clear plastic panel could have physical ridges in the plastic around the area where each on the PIN pad numbers can be displayed to assist in locating the button areas.
[0133] Swipe readers are also vulnerable to the attachment of a small additional swipe reader to one end or the other of the swipe track. The read head in the additional swipe reader captures the account number as the card passes through it.
[0134] Referring to FIGS. 12A and 12B a false front resistant swipe reader 500 includes blockages 502 at both ends so that it is impossible to add a skimming swipe reader to either end. The Swipe Reader 500 can include the encrypting magnetic stripe read head 504 . In one embodiment, the Swipe Reader 500 can also include the encrypting contact-less card and mobile NFC read module 506 . At the bottom of the swipe reader 500 the blockage 502 can include a drain hole 508 to allow any water or other fluid to escape.
[0135] The foregoing descriptions present numerous specific details that provide a thorough understanding of various embodiments of the invention. It will be apparent to one skilled in the art that various embodiments, having been disclosed herein, may be practiced without some or all of these specific details. In other instances, known components have not been described in detail in order to avoid unnecessarily obscuring the present invention. It is to be understood that even though numerous characteristics and advantages of various embodiments are set forth in the foregoing description, together with details of the structure and function of various embodiments, this disclosure is illustrative only. Other embodiments may be constructed that nevertheless employ the principles and spirit of the present invention. Accordingly, this application is intended to cover any adaptations or variations of the invention. It is manifestly intended that this invention be limited only by the following claims and equivalents thereof.
[0136] References to relative terms such as upper and lower, front and back, left and right, or the like, are intended for convenience of description and are not contemplated to limit the invention, or its components, to any specific orientation. All dimensions depicted in the figures may vary with a potential design and the intended use of a specific embodiment of this invention without departing from the scope thereof.
[0137] Each of the additional figures and methods disclosed herein may be used separately, or in conjunction with other features and methods, to provide improved devices, systems and methods for making and using the same. Therefore, combinations of features and methods disclosed herein may not be necessary to practice the invention in its broadest sense and are instead disclosed merely to particularly describe representative embodiments of the invention.
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Systems and methods to provide and maintain secure financial transaction conducted with a credit card or other cashless payment mechanism at a vending machine or other potentially unattended vending or point of sale device. Encapsulated card readers providing end-to-end encryption capabilities encrypt transaction data for secure transmission to a transaction host or server. Pre-authorization transaction data checking maintains account numbers in a secure encrypted format further enhancing security. Protection mechanisms that guard against, and provide warnings of equipment tampering, while also providing a visual indication to customers regarding the security of the system.
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FIELD OF THE INVENTION
The present invention relates to a method of making a polyfluorosulfonamido amine and the intermediate thereof.
BACKGROUND OF THE INVENTION
Polyfluorosulfonamido amines are useful starting materials for various products including: fluorinated surfactants, including cationic, non-ionic, anionic, and amphoteric surfactants; and fluorinated repellents, including (poly-(meth)acrylamides, ureas, imides. Specific applications for polyfluorosulfonamido amines include: electronics applications, nanotechnology, pharmaceutical and pesticide intermediates, catalysts, and firefighting foaming agents.
Rudimentary polyfluorosulfonamido amines can be generally described by the following formula:
R ff —S(O) 2 —NH—(CH 2 ) p —NH 2 (Formula A)
wherein
R ff is chosen from a C 4 to C 12 polyfluoroalkyl; and p is an integer from 2 to 8.
Current methods for making polyfluorosulfonamido amines like those of Formula A provide low yields and produce an undesirable fluorine containing by-product representing an economic loss. For example U.S. Pat. No. 4,486,391 contemplates making polyfluorosulfonamido amines of Formula A by reacting a polyfluoroalkylsulfonic acid or an ester thereof with a diamine as represented by the following:
R ff —S(O) 2 —Cl+H 2 N—(CH 2 ) p —NH 2 →R ff —(CH 2 ) p —S(O) 2 —HN—(CH 2 ) p —NH 2 (Reaction A)
wherein
R ff , and p are defined as above. Unfortunately, in addition to the desired monoamine product, Reaction A also produces an undesirable bis-sulfonamide by-product:
R ff —S(O) 2 —HN—(CH 2 ) p —NH—S(O) 2 —R ff
The bis-sulfonamide by-product is particularly undesirable because it shares very similar physical properties with the desired monoamine product thus making isolation of the desired monoamine product difficult and costly. Furthermore, instead of the efficient incorporation of fluorine to make the desired monoamine product, the bis-sulfonamide by-product constitutes a substantial loss of costly fluorinated starting material. The bis-sulfonamide by-product also constitutes an undesirable impurity that can worsen surfactancy, repellency, or other performance characteristics of the desired monoamine product.
Because of the aforementioned disadvantages, it would therefore be desirable to discover a method for making a polyfluorosulfonamido amine wherein the production of a bis-sulfonamide by-product is avoided.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a method of making a polyfluorosulfonamido amine without the production of a bis-sulfonamide by-product thereby advantageously avoiding the need for its removal for the purpose of isolating the desired polyfluorosulfonamido amine. Furthermore, the present invention advantageously avoids or drastically reduces the production any by-product which contains fluorine. The present invention achieves the aforementioned advantages by reacting a polyfluoroalkylsulfonic compound with a monoamino amide rather than with a diamine as in previously known methods.
Polyfluorosulfonamido amines made by the present invention are represented by the following:
R f —(CH 2 ) n —S(O) 2 —N(R 1 )—(CH 2 ) 2 —C m H 2m —N(R 1 )H (Formula 1)
wherein:
R f is chosen from a C 2 -C 12 polyfluoroalkyl optionally interrupted by one to four groups chosen from: —O—, —S—, and —S(O) 2 —;
each R 1 is independently chosen from hydrogen or a C 1 to C 6 alkyl, preferably hydrogen;
n is chosen from an integer from 0 to 6, preferably less than 3, more preferably 2;
m is chosen from an integer from 0 to 10, preferably 0 to 2, more preferably 1.
The present invention makes the polyfluorosulfonamido amines of Formula 1 by a method comprising the reaction of polyfluoroalkylsulfonic compound with a monoamino amide followed by deacylation, preferably acid catalyzed deacylation.
The polyfluoroalkylsulfonic compounds useful in this invention are represented by the following:
R f —(CH 2 ) n —S(O) 2 —X (Formula 2)
wherein
X is chosen from hydroxyl, aryloxy, substituted aryloxy, or a halide, and more preferably chlorine; and n is defined as above.
The monoamino amides useful in this invention are represented by the following:
HN(R 1 )—(CH 2 ) 2 —C m H 2m —N(R 1 )—C(O)—R 2 (Formula 3)
wherein
each R 1 is independently chosen from hydrogen or a C 1 to C 6 alkyl, preferably hydrogen;
m is defined as above; and
R 2 is chosen from hydrogen, a C 1 to C 6 alkyl, aryl, alkylaryl, or substituted aryl.
The monoamino amides useful in the invention can be made by reacting an ester with a diamine wherein:
i) the ester is represented by:
R 2 —C(O)—O—R 3 (Formula 4)
wherein
R 2 is chosen from hydrogen, a C 1 to C 6 alkyl, aryl, alkylaryl, or substituted aryl;
wherein
R 3 is chosen from a C 1 to C 6 alkyl, aryl, alkylaryl, or substituted aryl;
and
ii) the diamine is represented by:
HN(R 1 )—(CH 2 ) 2 —C m H 2m —N(R 1 )H (Formula 5)
wherein
each R 1 is independently chosen from hydrogen or a C 1 to C 6 alkyl, preferably hydrogen; and
m is defined as above.
In accordance with the invention, a polyfluoroalkylsulfonic compound (Formula 2) is reacted with a monoamino amide (Formula 3) to make a polyfluorosulfonamide amide intermediate product represented by:
R f —(CH 2 ) n —S(O) 2 —N(R 1 )—(CH 2 ) 2 —C m H 2m —N(R 1 )—C(O)—R 2 (Formula 6)
wherein
R f , n, R 1 , m, and
R 2 are defined as above.
The polyfluorosulfonamide amide intermediate product of Formula 6 is then subjected to deacylation to form the desired polyfluorosulfonamido amine of Formula 1.
Unless otherwise stated, the R f moiety referred to in Formula 1, Formula 2, and Formula 6 is chosen from a C 2 -C 12 polyfluoroalkyl optionally interrupted by one to four groups chosen from: —O—, —S—, and —S(O) 2 —. Examples of R f moieties include those chosen from a perfluoroalkyl without substitutions or interruptions include (CF 3 ) 2 CF, and CF 3 (CF 2 ) m wherein m is an integer from 1 to 11. Examples of R f moieties also include a perfluoroalkyl substituted by one hydrogen such as (CF 3 ) 2 CH, CF 3 (CF 2 ) 2 OCFHCF 2 , and HC m F 2m wherein m is 2 to 12. Examples of R f moieties also include a perfluoroalkyl which is interrupted by at least one oxygen such as CF 3 (CF 2 ) 2 OCF 2 CF 2 , CF 3 (CF 2 ) 2 OCFHCF 2 , and CF 3 CF 2 CF 2 [OCF(CF 3 )CF 2 ] m OCRF wherein m is an integer from 6 to 15 and R can be F, CF 3 , or H. Examples of R f moieties also include a C 2 -C 12 perfluoroalkyl which is interrupted by at least one methylene such as CF 3 (CF 2 ) 3 (CH 2 CF 2 ) m and CF 3 (CF 2 ) 5 (CH 2 CF 2 ) m wherein m is 1, 2, or 3. Examples of R f moieties also include a perfluoroalkyl which is interrupted by at least one ethylene such as F[(CF 2 CF 2 ) n (CH 2 CH 2 ) m ] k CF 2 CF 2 wherein n=1, 2, or 3 preferably 1; and m=1, or 2 preferably 1; and k=1, 2, or 3. Examples of R f moieties also include a polyfluoroalkyl which is interrupted by at least one sulfur (—S—) or sulfoxide (—SO2—) such as CF 3 (CF 2 ) 5 CH 2 CH 2 SCH 2 CH 2 , C6F13CH2CH2SO2CH2CH2, C6F13SCH2CH2.
DETAILED DESCRIPTION OF THE INVENTION
According to the method of the invention, the desired polyfluorosulfonamido amine product (Formula 1) is obtained by reacting a polyfluoroalkylsulfonic compound (Formula 2) with a monoamino amide (Formula 3) to form a polyfluorosulfonamide amide intermediate (Formula 6) which is subjected to deacylation. The various reactions resulting in the formation of the desired polyfluorosulfonamido amine product (Formula 1) may be represented as follows:
Reaction 1: formation of the monoamino amide of Formula 3
R 2 —C(O)—O—R 3 +HN(R 1 )—(CH 2 ) 2 —C m H 2m —N(R 1 )H→HN(R 1 )—(CH 2 ) 2 —C m H 2m —N(R 1 )—C(O)—R 2 +HO—R 3
Reaction 2: formation of the polyfluorosulfonamide amide intermediate of Formula 6
R f —(CH 2 ) n —S(O) 2 —X+HN(R 1 )—(CH 2 ) 2 —C m H 2m —N(R 1 )—C(O)—R 2 →R f —(CH 2 ) n —S(O) 2 —N(R 1 )—(CH 2 ) 2 —C m H 2m —N(R 1 )—C(O)—R 2
Reaction 3: formation of the polyfluorosulfonamido amine product of Formula 1 by deacylation
R f —(CH 2 ) n —S(O) 2 —N(R 1 )—(CH 2 ) 2 —C m H 2m —N(R 1 )—C(O)—R 2 →R f —(CH 2 ) n —S(O) 2 —N(R 1 )—(CH 2 ) 2 —C m H 2m —N(R 1 )H
Referring to Reaction 1, the esters (Formula 4) useful in the formation of the monoamino amide of Formula 3 may be obtained commercially and methods for making such are well known in the art. Example of suitable esters for use in the invention include: methyl acetate, ethyl acetate, n-propyl acetate, 2-propyl acetate, n-butyl acetate, n-pentyl acetate, n-hexyl acetate, phenyl acetate, benzyl acetate, methyl formate, ethyl formate, n-propyl formate, methyl benzoate, ethyl benzoate, n-propyl benzoate, methyl hexanoate, ethyl hexanoate, n-propyl hexanoate.
Alternative examples of suitable esters for use in the invention are di-, tri-, or poly-carboxylic esters such as oxalate, malonate, succinate, phthalate, terephthalate; with specific examples including
H 2 N—(CH 2 ) 3 —NH—C(O)—C(O)—NH—(CH 2 ) 3 —NH 2 and
H 2 N—(CH 2 ) 3 —NH—C(O)—C 6 H 4 —C(O)—NH—(CH 2 ) 3 —NH 2 .
Referring to Reaction 1, the diamines (Formula 5) useful in the formation of the monoamino amide of Formula 3 may be obtained commercially and methods for making such are well known in the art. Example of suitable diamines for use in the invention include n-ethyl ethylene diamine; 1,3-diaminopropane; 1,4-diaminobutane; 1,5-diaminopentane; 1,6-diaminohexane; 1,8-diaminooctane; 1,5-diamino-2-methylpentane; n-ethyl ethylene diamine; n-propyl ethylene diamine; and N,N′-dimethyl-1,3-diaminopropane.
Referring to Reaction 1, the suitable reaction conditions for forming the monoamino amide of Formula 3 are exemplified by adding a diamine (Formula 5) to a reaction vessel (preferably under inert conditions, e.g., with nitrogen purge) equipped with mechanical stirrer and a condenser which returns any boiled material back to the vessel. The diamine is then heated while stirring. The temperature is chosen so that it is about 5 to 10° C. lower than the boiling point of the expected alcohol of Reaction 1. An ester (Formula 4) is then added slowly to the diamine over a period of about 15 to 90 minutes while maintaining the reflux temperature and stirring to create a reactant mixture. The total amount of ester added should yield a molar ratio of diamine:ester of preferably about 1:1, however this molar ratio can range between 5:1 to about 0.6:1. The reflux temperature is maintained until the reaction is complete as evidenced by the complete consumption of the ester, e.g., as measured by gas chromatography. A completed reaction typically occurs after about 2 to 24 hours. When the reaction is complete the reaction vessel typically contains a product mixture comprising lower boiling point components and higher boiling point components. The lower boiling point components include: possible residual unreacted ester, an alcohol by-product, possible water from contamination, any acid resulting from the reaction of the ester with water, and any unreacted diamine. The higher boiling point components include: the desired monoamino amide (Formula 3), and a bis-sulfonamide by-product resulting from the further reaction of the monoamino amide with the ester, said diamide by-product represented by:
R 2 —C(O)—N(R 1 )—(CH 2 ) 2 —C m H 2m —N(R 1 )—C(O)—R 2 (Formula 7)
The lower boiling point components are removed from the product mixture by equipping the vessel with a distillation column and maintaining heat at a distillation temperature which causes the lower boiling point components to boil away while leaving behind the higher boiling point components. During distillation, the vessel can optionally be equipped with a vacuum source to reduce distillation pressure and temperatures. Typical distillation temperatures range from about 50 to 120° C. and can vary based upon the specific ester (Formula 4) and diamine (Formula 5) reactants chosen, the alcohol formed during the reaction, and the application of vacuum. It is important to remove unreacted diamine during the distillation of the lower boiling components to avoid the formation of an undesirable diamide by-product in Reaction 2, the diamide by-product represented by:
R f —(CH 2 ) n —S(O) 2 —N(R 1 )—(CH 2 ) 2 —C m H 2m —N(R 1 )—S(O) 2 —(CH 2 ) n —R f (Formula 8)
wherein
R f , n, R 1 are defined as above.
Referring to Reaction 2, the suitable reaction conditions for forming the polyfluorosulfonamide amide intermediate of Formula 6 are exemplified by dissolving a reactant comprising a monoamino amide (Formula 3) in a vessel (preferably under inert anhydrous conditions, e.g., with nitrogen purge) containing an appropriate aprotic solvent such methylene chloride, acetonitrile, dimethoxyethane, or tetrahydrofuran. The vessel is equipped with mechanical stirrer and a condenser. In addition to the monoamino amide, the reactant mixture can also comprise a diamide (Formula 7) which is a by-product of Reaction 1. The molar ratio of monoamino amide to diamide by-product should be preferably at least 1:1, more preferably at least 2:1, and most preferably at least 3:1. Preferably the reactant mixture comprises the higher boiling components of Reaction 1 as set forth above. The contents of the vessel are cooled to 0° C.; after which, a polyfluoroalkylsulfonic compound (Formula 2) is added to the vessel over a period of about 15 to 120 minutes while maintaining the temperature at 0° C. The molar ratio of monoamino amide (Formula 3) to the polyfluoroalkylsulfonic compound (Formula 2) is at least 2:1, the excess beyond the first molar equivalent of the monoamino amide is intended as a base to neutralize the acid generated in the reaction. If an additional base is used, then the molar ratio of monoamino amide (Formula 3) to the polyfluoroalkylsulfonic compound (Formula 2) can reduced to about 1:1. The contents of the vessel are then stirred for about 2 to 24 hours and allowed to warm to room temperature which results in a precipitation of typically colorless solids. The solids are filtered (removing the diamide by-product of Formula 7) and washed with water which dissolves and removes salt by-products created from the reaction of the monoamino amide with the acid. It is preferable that the water in the washing step comprises a surfactant which aids in wetting the solids. The isolated solid typically comprises from 50 to 90 weight % of the desired polyfluorosulfonamide amide intermediate (Formula 6).
Suitable reaction conditions for the formation of a polyfluorosulfonamido amine of Formula 1 as described in Reaction 3 above include conditions suitable for deacylation such as acid catalyzed deacylation. An example of acid catalyzed deacylation (also known as acid hydrolysis) dissolving a polyfluorosulfonamide amide intermediate (Formula 6) in a vessel (preferably under inert conditions, e.g., with nitrogen purge) containing an appropriate mixture of water and a polar solvent, preferably an alcohol, e.g., ethanol, or methanol, or an ether, e.g., 1,2-dimethoxyethane. The aforementioned solvents are preferable for the purpose of effectively reducing the foam formation as the hydrolysis proceeds, and allowing the deacylation reaction to proceed quickly to completion, with minimal by-products. The vessel is equipped with mechanical stirrer and a condenser which returns any boiled material back to the vessel. An acid (e.g., hydrochloric acid) is then added to the vessel between about 4:1 to 10:1 molar ratio of acid to polyfluorosulfonamido amine of Formula 1. The contents of the vessel are then heated to a temperature of from about 70 to about 100° C. The temperature is maintained until the reaction is complete as evidenced by the complete consumption of the polyfluorosulfonamide amide intermediate, e.g., as measured by gas chromatography. A completed reaction typically occurs after about 2 to 6 days. The amount of solvent is then reduced by about 80 weight % by distillation. The contents of the vessel are then cooled to about 25° C. and a strong base (e.g., NaOH, or KOH) is added until a pH of about 9 is achieved. Then an aqueous solution of precipitation agent (e.g., MgSO 4 ) is added to the vessel; typically comprising between 10 to 50 weight % of expected amount of polyfluorosulfonamido amine of Formula 1 causing the precipitation of a colorless solid The solid is then filtered and dried in a vacuum oven. The dried solid typically comprises from 60 to 95 weight % of the desired polyfluorosulfonamido amine of Formula 1.
EXAMPLES
The present invention is described in the foregoing example which is not intended to unduly restrict the invention as claimed.
Example 1
Preparation of 1,3-diaminopropane mono-acetamide
1,3-Diaminopropane mono-acetamide is an example of a monoamino amide (Formula 3) and was made by reacting an ester (methyl acetate) with a diamine(1,3-diaminopropane) as represented by the following:
CH 3 —C(O)—O—CH 3 +H 2 N—(CH 2 ) 3 —NH 2 →CH 3 —C(O)—O—NH—(CH 2 ) 3 —NH 2 (1,3-diaminopropane mono-acetamide)+CH 3 —C(O)—O—NH—(CH 2 ) 3 —NH—O—C(O)—CH 3 (1,3-diaminopropane bis-acetamide)+HO—CH 3 (methanol)
In a four-neck flask equipped with nitrogen purge, condenser, addition funnel and mechanical stirrer, about 125 grams (1.7 moles) of 1,3-diaminopropane (DAP) was added and heated to a temperature of 50° C. while stirring. Then about 82.9 grams (1.1 moles) of methyl acetate was added over 90 minutes while stirring. This reactant mixture was maintained at the reflux temperature of about 50° C. for about 18 hours after which all of the methyl acetate was consumed as determined by gas chromatography (GC) analysis. About 100 mL of dimethyl acetamide (DMAC) was added as a “chaser” to aid in the determination of proper distillation conditions. Then vacuum distillation was performed to remove all of the methanol and DAP as confirmed by GC analysis. GC analysis of the final product showed 19.5 weight % DMAC, 64.5 weight % 1,3-diaminopropane mono-acetamide, 16.0 weight % 1,3-diaminopropane bis-acetamide, and <0.1 weight % 1,3-diaminopropane.
Example 2
Preparation of N-[N′-acetyl-3-aminopropyl]-perfluorohexyl ethyl sulfonamide
N-[N′-acetyl-3-aminopropyl]-perfluorohexyl ethyl sulfonamide is an example of a polyfluorosulfonamide amide intermediate product (Formula 6) and was made by reacting a polyfluoroalkylsulfonic compound (perfluorohexyl ethyl sulfonyl chloride) with monoamino amide (1,3-diaminopropane mono-acetamide) as represented by the following:
C 6 F 13 —(CH 2 ) 2 —S(O) 2 —Cl+NH 2 —(CH 2 ) 3 —NH—O—C(O)—CH 3 →C 6 F 13 —(CH 2 ) 2 —S(O) 2 —NH—(CH 2 ) 3 —NH—O—C(O)—CH 3 (N-[N′-acetyl-3-aminopropyl]-perfluorohexyl ethyl sulfonamide)+[NH 3 —(CH 2 ) 3 —NH—O—C(O)—CH 3 ] + Cl − (1,3-diaminopropane mono-acetamide hydrochloride).
The final mixture obtained from the preparation of 1,3-diaminopropane mono-acetamide above (Example 1) was dissolved in 750 mL of acetonitrile in a four-neck flask equipped with nitrogen purge, condenser, addition funnel and mechanical stirrer. The dissolved mixture contained about 43.7 grams (0.38 moles) of 1,3-diaminopropane mono-acetamide, 1,3-diaminopropane bis-acetamide, and dimethyl acetamide. The mixture was cooled to about 0° C. Then about 120.1 grams (0.19 moles) of perfluorohexyl ethyl sulfonyl chloride as 70 weight % solution in toluene was added at 0° C. over 30 minutes while stirring. The mixture was stirred for an additional three hours and allowed to warn to room temperature producing a colorless solids which were filtered and washed with 1 liter of 0.1 weight % Zonyl® FSO-100 (a surfactant) in water to dissolve and remove 1,3-diaminopropane mono-acetamide hydrochloride. The remaining filtered colorless solid was analyzed by GC-mass spectrometry and proton NMR which confirmed the production of 89.5 grams (90% yield) of N-[N′-acetyl-3-aminopropyl]-perfluorohexyl ethyl sulfonamide.
Example 3
Preparation of N-[3-aminopropyl]-2-(Perfluorohexyl)ethane sulfonamide
N-[3-aminopropyl]-2-(Perfluorohexyl)ethane sulfonamide is an example of a polyfluorosulfonamido amines (Formula 1) and was made by the acid catalyzed deacylation (acid hydrolysis) of a polyfluorosulfonamide amide intermediate, N-[N′-acetyl-3-aminopropyl]-perfluorohexyl ethyl sulfonamide, as represented by the following:
C 6 F 13 —(CH 2 ) 2 —S(O) 2 —NH—(CH 2 ) 3 —NH—O—C(O)—CH 3 +HCl (catalyst)+H 2 O→C 6 F 13 —(CH 2 ) 2 —S(O) 2 —NH—(CH 2 ) 3 —NH 2 (N-[3-aminopropyl]-2-(Perfluorohexyl)ethane sulfonamide)+H—O—C(O)—CH 3 (acetic acid).
The final product obtained from the preparation of N-[N′-acetyl-3-aminopropyl]-perfluorohexyl ethyl sulfonamide above (Example 2) was dissolved in 170 grams of ethanol in a four-neck flask equipped with nitrogen purge, condenser, addition funnel and mechanical stirrer. The dissolved mixture contained about 56.9 grams (0.11 moles) of N-[N′-acetyl-3-aminopropyl]-perfluorohexyl ethyl sulfonamide. About 62 grams of 37 weight % hydrochloride acid in water was added while stirring. This mixture was heated to a reflux temperature of about 80° C. for about 5 days until all of the N-[N′-acetyl-3-aminopropyl]-perfluorohexyl ethyl sulfonamide was consumed as confirmed by GC. Then about 130 mL of ethanol/water/HCl was removed by distillation. The resulting mixture was allowed to cool to 25° C. and then the pH was adjusted to about 9 by addition of KOH. Then about 100 grams of 10 weight % aqueous MgSO 4 was added causing the precipitation of a colorless solid which was filtered and dried in a vacuum oven, which was analyzed by GC-mass spectrometry and proton NMR which confirmed the production of 45.1 grams (87% yield) of N-[3-aminopropyl]-2-(Perfluorohexyl)ethane sulfonamide.
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Current methods for making polyfluorosulfonamido amines, which involve the use of a diamine reactant, provide low yields and produce an undesirable fluorine containing bis-sulfonamide by-product representing an economic loss. The bis-sulfonamide by-product is particularly undesirable because it shares very similar physical properties with the desired monoamine product thus making isolation of the desired polyfluorosulfonamido amine product difficult and costly. Furthermore, instead of the efficient incorporation of fluorine to make the desired polyfluorosulfonamido amine product, the bis-sulfonamide by-product constitutes a substantial loss of costly fluorinated starting material. The bis-sulfonamide by-product also constitutes an undesirable impurity that can worsen surfactancy, repellency, or other performance characteristics of the desired polyfluorosulfonamido amine product. The present invention provides a method of making a polyfluorosulfonamido amine without the production of a bis-sulfonamide by-product by reacting a polyfluoroalkylsulfonic compound with a monoamino amide rather than with a diamine reactant as in previously known methods.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to vehicular audio/video techniques, more particularly, this invention relates to an audio/video expansion device provided with learning function, a vehicular audio/video system using the same and its learning method.
[0003] 2. Description of the Related Art
[0004] Traditionally, the shipping configuration of a car includes audio/video devices such as a stereo system and speakers. As the audio/video technology advances and users? demand on better audio/video experiences increases, an audio/video system is now become a popular option to vehicular users. The inventor of the present invention disclosed Vehicular Audio/Video Device and a Circuit of a Vehicular Audio/video Device for Integrating Auxiliary Input? in Taiwanese Utility Patent Number 225478. The vehicular audio/video device disclosed integrates a plurality of auxiliary inputs without alternating the hardware configuration of a conventional host system. A playback device for providing an auxiliary signal source often equips with a remote control for the user ease of use. However, when a user has several playback devices in use, the user is often confused by finding the correct remote control for the certain playback device. In addition, if a user is in a vehicle, the user is easily distracted by the extra effort required to match the remote control and the playback device and the user is at risk.
SUMMARY OF THE INVENTION
[0005] It is therefore an objective of this invention to provide a vehicular audio/video expansion device with learning function, a vehicular audio/video system using the same and its learning method. The invention integrates the functions of buttons on one or a plurality of remote controls into the functions of buttons on a host so that a driver does not need to pay extra attention on matching the remote controls and playback devices and driver safety is protected.
[0006] In order to achieve the above purpose, the present invention provides a vehicular audio/video expansion device provided with learning function. The vehicular audio/video expansion device is coupled to the host and the playback device. The playback device comprises a remote control provided with a first button associated with a first control code for controlling the playback device when the first button is pressed. The host has a second button. The second button is associated with a second control code for the expansion device when the second button is pressed. The vehicular audio/video expansion device comprises a receiver for receiving the first control code, a controller coupled to the receiver and the host for processing the first control code and the second control code, and a memory coupled to the controller. The controller associates the first control code and the second control code to generate a corresponding relation and stores the corresponding relation in the memory under a learning mode. The controller generates a third control code for controlling the playback device according to the corresponding relation when the second button is pressed under an operation mode.
[0007] It is another objective of this invention to provide a vehicular audio/video system provided with learning function. The system comprises a playback device with a remote control, a host and an expansion device. The remote control provided with a first button associated with a first control code for controlling the playback device when the first button is pressed. The host provided with a second button associated with a second control code for the expansion device when the second button is pressed. The expansion device coupled to the host and the playback device. The expansion device processes the first control code and the second control code to generate a corresponding relation under a learning mode. The expansion device generates a third control code for controlling the playback device according to the corresponding relation when the second button is pressed under an operation mode.
[0008] It is another objective of this invention to provide a learning method for using a vehicular audio/video system. The learning method comprises: initiating a learning status; pressing a first button on a remote control to transmit a first control code for controlling a playback device; receiving the first control code at a expansion device; pressing a second button at a host to generate a second control code for the expansion device; and receiving the first control code an the second control code at the expansion device to generate a corresponding relation. The function of the first button is replaced by the function of the second button according to the corresponding relation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 illustrates a block diagram of a preferred embodiment of a vehicular audio/video system according to the present invention;
[0010] FIG. 2 illustrates a flow chart of a preferred embodiment of a learning method with the vehicular audio/video system according to the present invention;
[0011] FIG. 3 illustrates a block diagram of an alternative preferred embodiment of a vehicular audio/video system according to the present invention;
[0012] FIG. 4 illustrates a block diagram of another alternative preferred embodiment of a vehicular audio/video system according to the present invention; and
[0013] FIG. 5 illustrates a detailed circuit diagram of a vehicular audio/video device with learning function according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] FIG. 1 illustrates a block diagram of a preferred embodiment of a vehicular audio/video system according to the present invention. In the vehicular audio/video system shown in FIG. 1 , the vehicular audio/video system 1 comprises a host 10 , an expansion device 20 , a playback device 30 and at least one speaker 40 .
[0015] The host 10 comprises an AM/FM tuner, a cassette player, an amplifier and audio process circuit such as a crossover. In addition to process the audio signals from the AM/FM tuner and the cassette player, the host 10 also processes audio signals from the signal wire 70 of the expansion device 20 or from the signal wire 69 of the playback device 30 , then output the processed audio signals to the speaker 40 . Alternatively, a host 10 is built in with a video display and a video process circuit for receiving and processing the video signals from the signal wire 70 of the expansion device 20 or from the signal wire 69 of the playback device 30 . Alternatively, a host 10 is not build in with a video display and a video process circuit, then the video signals from the signal wire 70 of the expansion device 20 or from the signal wire 69 of the playback device 30 output to an external video display 50 . Alternatively, a host is build in with a DVD player, VCD player, CD player or a MD player.
[0016] A playback device 30 is an audio signal source, an video signal source or an external audio/video mixed signal source, such as a detachable media storage device (for example, an MP3 player, MPEG-4 player, or an Apple iPod), a tuner, an analog TV box, digital TV box, a satellite receiver, a video cassette recorder/player, an karaoke machine, a DivX recorder/player, an HDMI player, a game console and a optical disc player. The optical disc player can be an audio player such as a CD player, and sometimes is an audio/video player such as a VCD player, or a DVD player. The playback device 30 transmits audio signals or video signals to the expansion device 20 via signal wire 68 . The expansion device 20 transmits the audio signals or video signals to the host 10 via signal wire 70 for signal processing. If the expansion device 20 is connected to a single playback device 30 , then the playback device 30 transmits the audio signals or video signals to the host 10 via signal wire 69 for signal processing directly.
[0017] The playback device 30 has a designated remote control 32 . The remote control 32 is built with certain control buttons 34 for controlling operations of the playback device 30 . If the playback device 30 is a digital TV receiver, the buttons 34 on the remote control 32 can be the buttons H+? or H−? for channel selections. The remote control 32 transmits corresponding control code 60 when H+? or H−? is pressed. The receiver 36 installed at the playback device 30 receives the control code 60 for controlling the channel selection of the digital TV receiver. The signals transmitted from the remote control 32 to the playback device 30 can be infrared (IR) signals or radio frequency (RF) signals.
[0018] The objective of the present invention is to replace the button 34 on the remote control 32 with the button 12 on the host 10 by performing the learning operations at the expansion device 20 . The learning method makes the function of the button 34 on the remote control 32 associated with the function of the button 12 on the host 10 . Upon the learning method completes, the button 12 on the host 10 replaces the button 34 on the remote control 32 and the button 12 control the playback device 30 directly. The learning method is detailed in FIG. 2 . Referring to FIG. 1 and FIG. 2 , the playback device 30 being a digital TV is exemplified to demonstrate steps of the learning method to replace the buttons H+? and H−?
[0019] As shown in FIG. 2 , the step S 1 is the beginning of the leaning method and the step S 2 is the judgment step on if a user presses the learning initiation button. In the preferred embodiment, the DISK SCAN button on the host 10 is predefined as the learning initiation button. At the S 2 , the user decides if the DISK SCAN button on the host 10 is pressed or not. If the judgment is yes, then the learning moves to the step S 3 to initiate the learning status of the remote control 32 . The step S 4 is a judgment on if the remote control 32 receives the control code 60 after the learning status initiated. If the remote control 32 does not receive the control code 60 , which means the user does not press the button 34 on the remote control 32 , the learning moves to the step S 5 to terminate the learning status of the remote control and return to the step S 1 . If the user presses the button 34 on the remote control 32 , which means at the step S 4 the receiver 22 of the expansion device 20 receives the control code 60 , the learning moves to the step S 6 . The step S 6 is a judgment on if the corresponding button 12 is pressed on the host 10 and corresponding control code is transmitted to the expansion device 20 via control wire 62 . If the button 12 is not pressed on the host 10 at the step S 6 , then the learning moves to the step S 5 to terminate the learning status of the remote control. If the button 12 is pressed at the step S 6 , then the learning moves to the step S 7 , the control code transmitted by the control wire 62 is linked to the control code 62 from the remote control 32 . For example, the expansion device 20 links the function of the button pressed on the remote control 32 , the H+? button, to the function of the button pressed on the host 10 , the SEEK/TRACK UP button by establish a corresponding relation of the control codes. The expansion device 20 stores the corresponding relation and then the learning method moves to S 5 .
[0020] At the step S 2 , if the DISK SCAN button is not pressed, then the learning moves to a operation mode, where the button 12 on the host 10 replaces the button 34 on the remote control 32 . It follows that at the step S 8 , the control code is transmitted to the expansion device 20 via the control wire 62 after pressing the button 12 such as a SEEK/TRACK UP button on the host 10 . According to the corresponding relation stored at the expansion device 20 , the control code from the host 10 corresponds to the button CH+ on the remote control 32 . A transmitter 24 on the expansion device 20 transmits the control code 64 corresponding to the button CH+ to the playback device 30 . The receiver 36 on the playback device 30 receives the control code 64 such that he playback device 30 adjusts the audio or video signals according to the control code 64 . The audio or video signals then are transmitted to the expansion device 20 via the signal wire 68 or output to the host 10 via the signal wire 69 . The signal transmission used between the expansion device 20 and the playback device 30 can be IR or RF signaling. As shown in FIG. 1 , if the expansion device 20 is connected to the playback device 30 with a control wire 66 , then the control codes 64 can be transmitted via the control wire 66 and the transmitter 24 can be waived.
[0021] Furthermore, when the expansion device 20 is installed with a learning initiation button or initiation control wire as shown in the reference numeral 26 in FIG. 1 , the step S 2 shown in the FIG. 2 is a judgment step on if the learning method is initiated by pressing initiation button is pressed or enabling the initiation control wire at the expansion device 20 .
[0022] FIG. 3 illustrates a block diagram of an alternative preferred embodiment of a vehicular audio/video system according to the present invention. As shown in the FIG. 3 , the vehicular audio/video system comprises a host 10 , an expansion device 20 , a plurality of playback device 30 A, 30 B, 30 C and a speaker 40 .
[0023] The host 10 comprises an AM/FM tuner, a cassette player, an amplifier and audio process circuit such as a crossover. In addition to process the audio signals from the AM/FM tuner and the cassette player, the host also processes audio signals from a signal wire 70 of the expansion device 20 , and then output the processed audio signals to the speaker 40 . Alternatively, a host 10 is built in with a video display and a video process circuit for receiving and processing the video signals from the signal wire 70 of the expansion device 20 . Alternatively, a host 10 is not build in with a video display and a video process circuit, then the video signals from the signal wire 70 of the expansion device 20 output to an external video display 50 . Alternatively, the host 10 can be build in with a DVD player, VCD player, CD player or a MD player.
[0024] A plurality of playback devices 30 A, 30 B, and 30 C are audio signal source, video signal source or external audio/video mixed signal source, such as an detachable media storage device (for example, an MP3 player, MPEG-4 player, or an Apple iPod), a tuner, an analog TV box, digital TV box, a satellite receiver, a video cassette recorder/player, an karaoke machine, a DivX recorder/player, an HDMI player, a game console and an optical disc player. The optical disc player can be an audio player such as a CD player, and sometimes is an audio/video player such as a VCD player, or a DVD player. The playback devices 30 A, 30 B, and 30 C transmits audio signals or video signals to the expansion device 20 via signal wire 68 A, 68 B, and 68 C. The expansion device 20 selects one input among 68 A, 68 B, and 68 C, and then transmits the audio signals or video signals selected to the host 10 via the signal wire 70 for following signal processing. In the present preferred embodiment, three playback devices 30 A, 30 B and 30 C are utilized as one example, the applications according to the invention is not limited by the embodiment. Preferred embodiments may apply two, four or multiple playback devices as the embodiments fit.
[0025] The playback device 30 A, 30 B and 30 C have a designated remote controls 32 A, 32 B and 32 C. The remote controls 32 A, 32 B and 32 C are built with certain control buttons 34 A, 34 B and 34 C for controlling operations of the playback devices 30 A, 30 B and 30 C. When the playback device 30 A is a digital TV receiver, the buttons 34 A on the remote control 32 A are the buttons H+? or H−? for channel selections. The remote control 32 A transmits corresponding control code 60 when H+? or H−? is pressed. The receiver 36 A installed at the playback device 30 A receives the control code 60 for controlling the channel selection of the digital TV receiver. The signals transmitted from the remote control 32 A to the playback device 30 A are infrared (IR) signals or radio frequency (RF) signals.
[0026] The aim of the present invention is to replace the button 34 A, 34 B, and 34 C on the remote control 32 A, 32 B and 32 C with the button 12 at the host 10 by performing the learning operations at the expansion device 20 . The learning method connects the function of the button 34 A, 34 B, and 34 C on the remote control 32 A, 32 B and 32 C with the function of the button 12 on the host 10 . Upon the learning method completes, the button 12 on the host 10 replaces the buttons 34 A, 34 B, and 34 C on the remote controls 32 A, 32 B and 32 C and the button 12 control the playback device 30 directly. The learning method is detailed in FIG. 2 .
[0027] As shown in FIG. 3 , after the learning method completes, a transmitter 24 at the expansion device 20 transmits corresponding control code 64 to the playback device 30 A, 30 B or 30 C. The receiver 36 A, 36 B or 36 C at the corresponding playback device 30 A, 30 B or 30 C receives the control code 64 . One of the playback device 30 A, 30 B and 30 C adjusts the audio or video signals according to the control code 64 and transmits the signals to the to the expansion device 20 via one of the signal wire 68 A, 68 B and 68 C.
[0028] The signals transmission used between the expansion device 20 and the playback device 30 A, 30 B and 30 C can be IR or RF signals. As shown in FIG. 3 , if the expansion device 20 is connected to the playback device 30 A, 30 B and 30 C with a control wire 66 A, 66 B and 66 C respectively, then the control codes can be transmitted via the control wire 66 A, 66 B or 66 C such that the transmitter 24 can be waived.
[0029] FIG. 4 illustrates a block diagram of another alternative preferred embodiment of a vehicular audio/video system according to the present invention. As compared FIG. 4 with FIG. 1 , the expansion device and the host 10 are integrated to be a single host 100 in the preferred embodiment disclosed in the FIG. 4 . The rest of the configuration disclosed in the preferred embodiment shown in the FIG. 4 is similar to the preferred embodiment shown in the FIG. 1 and thus is not repeated here.
[0030] FIG. 5 illustrates a detailed circuit diagram of a vehicular audio/video device 20 with learning function according to the present invention. As shown in FIG. 5 , the expansion device 20 has a micro controller 200 , a control code memory 210 and a signal switch 220 . The micro controller 200 controls operations of expansion device 20 . The control code memory 210 is coupled to the micro controller 200 for storing a corresponding relation between the button 34 on the remote control 32 and the button 12 on the host 10 . The signal switch 220 is coupled to the micro controller 200 for switching the plural auxiliary inputs (AUX 1 _Audio/AUX 1 _Video, AUX 2 _Audio/AUX 2 _Video, AUX 3 _Audio/AUX 3 _Video) from three playback devices shown in the FIG. 5 . Further, the audio output terminal 221 of the signal switch 220 is coupled to an audio buffer 230 and the video output terminal 222 of the signal switch 220 is coupled to a video buffer 240 . The output terminals of audio buffer 230 and video buffer 240 connected to the host 10 form the signal wire 70 .
[0031] As shown in FIG. 5 , the control wire 62 between the host 10 and the expansion device 20 has a bus buffer 250 . In details, the bus buffer 250 is provided between the micro controller 200 and the host 10 . The receiver 22 and the transmitter 24 are coupled to the micro controller 200 for receiving the control code 60 and transmitting the control code 64 . If the transmitter 24 is an infrared transmitter, then an oscillator 260 of 38 KHz is installed between the micro controller 200 and the transmitter 24 . Alternatively, the oscillator of 38 KHz can be replaced by generating 38 KHz oscillating frequency by running software or firmware at the micro controller 200 . As described previously, the expansion device 20 may transmit control code directly via the control wire 66 and as a result the transmitter 24 can be waived. A voltage regulator. 270 is provided for transforming the 12V DC to 5V DC or 8V DC as the power source of the expansion device 20 .
[0032] The present invention has been described with a preferred embodiment thereof and it is understood that many changes and modifications in the described embodiment can be carried out without departing from the scope and the spirit of the invention that is intended to be limited only by the appended claims.
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A vehicular audio/video expansion device provided with learning function, a vehicular audio/video system using the same and its learning method have been disclosed. According to the present invention, the vehicular A/V system comprises: a playback device having a remote control provided with a first button associated with a first control code for controlling the playback device when the first button is pressed; a host provided with a second button associated with a second control code; and an expansion device coupled to the host and the playback device. The expansion device processes the first control code and the second control code to generate a corresponding relation under a learning mode. According to the corresponding relation, the function of the first button is replaced by the second button to control the playback device under an operation mode.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to the methods and apparatus for tasting beverages, oils and other foods.
[0003] 2. Description of the Related Art
[0004] The evolution in wine tasting and appreciation has been driven by a concerted marketing effort on the part of wine making companies, supporting tourism businesses and a growing understanding of the average consumer of wine types, growing regions and pairings with food for enhanced dining experiences. Webster's defines oenophile as a lover or connoisseur of wine. A category of consumers have come to not only know the definition of the term, but consider themselves oenophiles.
[0005] Wineries and wine marketing organizations promote wine use the aromatic qualities to characterize the experience and to assist tasters in the selection of wine. The characteristics of the wine are used for comparison to other wines, wine regions and for food pairings. As part of the tasting of the wine, the taster is left with these directions and his or her own nose to discern the aromas and flavors that may be present in the wine or other beverage. It is one objective of the present invention to provide an apparatus and method to assist the taster who tastes wine or other aromatic beverages by providing comparison aromatic scents.
[0006] Additionally, single malt scotch brands have specific scents and aromas called out on their labels as an enhancement to the taster seeking to discern what they are consuming, what they like about it and to give the consumer some talk about the beverage to complete the experience and share the common experience with others. This enhanced experience requires some suggestion to the taster to enable him or her to discern what is present in the beverage being sampled.
[0007] The emergence of coffee and tea shops on every corner of America, have made consumers aware of a great many different flavor and aroma experiences. He is now confronted with a dizzying array of choices for morning and, now evening, coffees just when he is trying to get to work or home. In this promotion, it has become more and more difficult to sample and make the choices necessary for a well thought out choice of beverage.
[0008] Additionally, it is well known in the art, that the taste of a consumed item is heavily influenced by the aroma or “nose” of the thing being tasted or sampled. In the case of wine and other fermented or distilled beverages, the vendor provides the user with a written description of the flavors that are asserted present in the item being consumed by the user. In this suggestive manner, the vendor is attempting to create an experience in the use of the product, and thereby differentiate the product from others and attempt to make the taster feel as though the use of the product is an experience rather than a simple exercise of consumption.
[0009] Prior art attempts to address this issue have, in at least one case, been to create guidance to wine enthusiasts to better describe the aromas encountered in the experience of tasting wine. The intent is to prompt the person's memory with words that describe the aromas, such as apple, nutty, or fig, to name a few. An example of this approach can be found at http://www.essentialwinetastingguide.com/. The guide provides a pocket reference of the aromas encountered in the different wine varietals. This type of art represents the compilation of notes made over years of tasting and shared with wine connoisseurs and consumers. The intent of this type of guidance is to enhance their mental relationship to aromas they may have sampled in the past.
[0010] This discernment of the tastes present in the beverage or palate of the beverage is all part of a tasting experience that involves the examination of the product in a glass or other vessel suitable for viewing the color, sediment that may be present, checking other qualities such as the weight or body of the beverage, sampling the nose of the beverage, as is the subject of the present invention, examining the palate of the beverage, and evaluating the finish of the sample taken as part of the method of tasting the beverage. It is this overall experience that the present invention intends to enhance with a method and apparatus not present in prior art attempts to enhance the tasting experience.
[0011] Additional art attempts to provide an extensive selection of aromas claim they will allow an amateur taster to gain the palate of an expert. An example of such an aroma collection is the Le Nez Du Vin Wine Education Kit, which can be found at www.shop.com as of January 2007. The product description says it is a kit that will enable the user to develop his senses to the level of experts and allow the detection of wine components and the environment in which it was grown.
[0012] Much as wine tasters have created a wine tasting wheel to use an agreed upon terminology, coffee tasters can use the a Coffee Taster's Flavor Wheel to grade coffees or a flavor characteristics chart. The flavor wheel is designed for the trained pallet of a professional. Professionals can use the guidance when buying coffee and for creating taste characteristic profiles of the coffees. The average consumer who may not appreciated all that the professional is promoting in the coffee can use a much simplified flavor characteristics chart, which is a simplified method of charting your favorite coffee or brewed beverage characteristics. Similar embodiments of flavor guidance exists for aromatic oils, such as olive oils, and any other aromatic fine food that has a “family” of aromas and flavors dependent upon the type of stock or material, or processing used to make it.
[0013] What the prior art lacks is a method or apparatus that presents the aromas or essences in an environment or method that is similar to that which the wine or other beverage will be tasted and simulates that experience in a manner of elegance similar to the actual tasting itself. The prior art merely presents the essences in some sort of container and provides instructions as to which wines would be expected to have particular scents. There is no enhancing of the wine tasting experience occurring when the user of these types of products has to lug around a kit of vials or other form of essence container.
[0014] Therefore, what is needed is a means and simple to use method for facilitating the comparison of wines, distilled, brewed or other aromatic beverage, liquids or fine foods being tasted to aromas that may be present with little detraction from the elegance of the tasting experience. The method should be similar to the actual tasting experience and be conducted in a manner that can be easily shared by all participants in the tasting. Additionally, the apparatus to conduct the comparison of aromas should be as elegant as the wine or other aromatic beverage, liquid or fine food tasting itself. An apparatus that could be economically employed to enhance the wine tasting experience would be of benefit to the producers, sellers and consumers of millions of aromatic beverages consumed in United States each year.
SUMMARY
[0015] It is an object of the present invention to provide an apparatus and method of presenting wine or other beverage related aromas for use in a tasting as an elegant and experience enhancing supplement. The contemplated aromatic beverages include wines, juices, distilled spirits, fermented beverages, brewed beverages, coffees, or teas. Alternatively, the tasting of olive and other oils, flavored naturally or by addition of ingredients after processing, is within the contemplated scope of this invention. Basically any type of drink, liquid or fine food where the tasting experience could be enhanced by presentation of a standard of aromas that would allow the discernment of flavors among the variety of flavors that may be present in the object of the tasting.
[0016] It is also an object of the present invention to provide aromas in groupings reflective of categories of wines, wine varietals such as a Cabernet Sauvignon or Merlot for example, or differences in scotch malt or malt preparation. In the case of coffees or teas, the aromas presented would be reflective of the growing regions or environments applicable to those products. In the case of olive and other distinctive oils, for example, the characteristics of the fruit maturity, climate of growth, soil and other environmental factors, imbue a different tasting experience that can be captured in aromas for use in the tasting. Alternatively, it is an object of this invention to provide aromas in groupings that are reflective of the environment in which, for example, the wine grapes are grown, such as the terroir or earthy aspects of the wine or oil, for example. Also, alternatively, it is an object of the present invention that the aromas can be grouped in manners or length of malt toasting or charcoal wood for filtering, in the case of malted beverages. In the case of brewed beverages, such as beer, coffee or tea, the toasting or other preparation techniques used to add distinctive flavors would be the types of aromas of interest to the methods and apparatus claimed here.
[0017] Still another object of the invention is to provide a method for using the aromas in a manner that simulates the actual tasting of the wine or other beverages. In this manner the person tasting the wine is presented with the essences in an environment that is similar to the wine being tasted.
[0018] Still yet another object of the invention is to provide an apparatus that is easy to use by the average beverage tasting consumer. The apparatus is easily portable and used with a minimal instruction to the user. The instructions for use can be provided on the apparatus, such that the apparatus itself is both useful and instructional.
[0019] Other aspects and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The invention, together with further advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings.
[0021] FIG. 1 a represents an embodiment of the invention whereby a carrier material consisting preferably of a porous card stock or other inexpensively manufactured material is used to support encapsulated samples of aromatic scents useable in the exemplary wine tasting methods described herein.
[0022] FIG. 1 b represents an embodiment of similar configuration as shown in FIG. 1 a for other aromatic beverages, using a similarly configured carrier material impregnated with aromatic scents of appropriate selection.
[0023] FIG. 1 c represents an embodiment of similar configuration as shown in FIG. 1 a for hot brewed beverages.
[0024] FIG. 2 represents an embodiment of the most basic form of the invention using carrier material cards for the aromatic scents used in the beverage tasting methods described herein.
[0025] FIG. 3 represents an embodiment reflecting a more complex form of the carrier material cards with several of the aromatic scents used for the methods disclosed herein and also perforation separations and business logo information shown.
[0026] FIG. 4 represents an embodiment illustrative of how the FIG. 3 cards can be grouped into packs of cards for multiple use scenarios or for different groupings of the scents in the manner disclosed herein.
[0027] FIG. 5 represents an alternate embodiment illustrating a configuration showing groupings by wine varietal as an exemplary embodiment.
DETAILED DESCRIPTION
[0028] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some or all of these specific details. In other instances, well known items used to complete the process and method steps have not been described in detail in order not to unnecessarily obscure the present invention.
[0029] The present invention comprises an apparatus and method of use by which the tasting of wine or other aromatic beverages, oils, liquids or fine foods can be enhanced through the use of a complementary selection of aromatic scents selected specifically or generally for the beverage being consumed. The embodiments described herein are largely oriented to the consumption of wine or other fermented beverages, but as connoisseur of other beverages or foods where such methods enhance the experience would appreciate, the claimed invention is not limited to use for wine or the other exemplary beverages described herein. The order of presentation is exemplary in the embodiments presented and may be altered as necessary to provide a beverage tasting experienced desired by the user of the present invention. We are all consumers of beverages, each having our own preferences that are based from the basic concepts presented and claimed herein.
[0030] In a first exemplary embodiment, invention claimed herein is commonly available scratch and sniff cards which are appropriately selected from amongst commonly available scents. The selected one or more cards can be sampled by a sniff or inserted in some glass or chamber that allows the scents to build up and present themselves to the taster. The selection of the aromatic scents on the cards is based on the suggestive nature of the beverage being consumed. The suggestion of the scents is done by someone of discerning pallet for the beverage which could be the producer of the beverage or any other qualified taster. Additionally, the scents could be selected by consensus among a group and then when compared to the selected beverage, a greater appreciation for the constituent scents is achieved. As can be appreciated by anyone familiar with the tasting of beverages, oils, liquids or other fine foods, there are a great many varieties of tasting experiences where the sampling of an aroma can be done in a manner that enhances and, thus, the embodiments presented here are merely exemplary.
[0031] The embodiment shown in FIG. 1 a illustrates the present invention being used to taste wine 10 . One or more of the cards 11 comprising the carrier material with multiple scents thereon is selected an inserted by the taster into a glass 13 similar to that which will be used to taste the wine. Dissimilar glasses or other chambers may be used, but the experience is likely to be heightened by using similarly glasses of similar volume and shape. The consumer or taster's nose is then used in accordance with common practices of tasting to sample the chamber now full of the aromatic scent or mixed scents being emitted from the cards 11 in the glass 13 . Thus a comparison of the selected scents to those present in the wine being tasted can be achieved. The taster then can achieve an appreciation of the subtle flavors of the wine or other aromatic liquid being tasted.
[0032] As it can be appreciated, the method described above can be repeated for additional tastings. The selection of the scents can be altered and either a different wine selected or the same wine selected with a different combination of one or more scents. Thus, the taster can narrow in on the right combination of the scents necessary for full appreciation of the subtleties of the wine being tasted.
[0033] FIG. 1 b shows another preferred embodiment of the present invention being used to sample beverages other than wine 12 . Scotch, rum or tequila, for example, are examples of distilled spirits that produce distinctive aromas and could benefit from use of the present invention. It can be appreciated by any connoisseur of similar beverage types that other spirits would benefit as well. Included in these additional beverages are brewed malt beverages, such as beer, malt liquor and hard cider, for example. The card carrier material 11 is inserted into a beverage glass 14 of a shape similar or dissimilar to that of the cocktail or other beverage being sampled. Similar to that shown in FIG. 1 a , the taster samples the nose of the glass containing the card or cards selected and will get a sense of the scent or scents selected on the cards for use in the comparative tasting. The beverage consumer or taster then proceeds to get a similar sample of the nose of the actual beverage. Again, as with the wine, the comparison of the two results in an enhanced tasting experience and allows for the discernment of subtle flavors that may be present in the beverage.
[0034] FIG. 1 c shows another preferred embodiment of the present invention being used to sample brewed beverages. Coffee, espresso, or teas, for example, are examples of brewed beverages that produce distinctive aromas and could benefit from use of the present invention. It can be appreciated by any connoisseur of similar beverage types that other hot beverages would benefit as well. Similar to that shown in FIG. 1 a , the card carrier material 11 is inserted into a beverage glass 15 of a shape similar or dissimilar to that of the brewed or other beverage being sampled. The taster samples the nose of the glass containing the card or cards selected and will get a sense of the scent or scents selected on the cards for use in the comparative tasting. The beverage consumer or taster then proceeds to get a similar sample of the nose of the actual beverage. As with previous examples, the comparison of the two results in an enhanced tasting experience and allows for the discernment of subtle flavors that may be present in the beverage.
[0035] FIG. 2 illustrates an embodiment of the apparatus of the present invention, a card 30 consisting of a carrier material suitable to retain the means of producing the scent to be used 20 . The area 20 is the active area of scent on the card. The active area can be encapsulated aromatic cells that are easily broken to produce the desired scent or other active component which has an attribute which when stressed or disturbed produces one or more scents suitable for the beverage tasting methods of the present invention. Additionally, an embodiment contemplates the use of hand warming or artificial heat sources to activate the area and cause the release of the aroma. It is an objective of the invention to ensure the taster has whatever means necessary to release the aroma in a way that emulates the food generated aromas to be sampled as part of the methods described herein.
[0036] Each active area 20 on the card can consist of a single scent or a mixture of scents specifically chosen to enhance the tasting experience of a selected beverage or group of beverages. Each grape variety has its own inherent flavors; Zinfandel often has aromas and flavors of peppery spice, berries and jam, Sauvignon Blanc often has aromas and flavors of grass, citrus and melon, Chardonnay often has aromas and flavors of butter, vanilla and apples, Cabernet Sauvignon often has aromas and flavors of berries, cocoa, and bell peppers, etc. If the beverage is a distilled, brewed or hot brewed beverage additional aromas appropriate to these beverage types are contemplated. When the embodiment appropriate to olive oils, other oils or other fine foods is used, yet a different selection of aromas of the other types described herein is appropriate.
[0037] As a matter of further example, the scents can be selected from fruits or aromatic spices present in the growing region of products used to create the beverage or oil, such as grapes for wine. The pollen from trees that may be native or non-native to the growing region a further example of the scents that may be used. As previously presented, the scents may be singularly present or present in mixtures on a single active area of the present invention. For each beverage, oil or other fine food being tasted, the aromas distinctive to that type of beverage would be selected for the samples provided on the active areas of the cards or carrier material used. In this sense, carrier material is broadly defined as any material that might hold the scent or aroma in a manner conducive to its use in the methods presented here.
[0038] Because the present invention may be useful to promote specific products and can be mass produced in a manner that allows a producer to provide them with the product to be tasted, FIG. 3 shows an embodiment where the card 11 is combined with an area 21 reserved for a logo or other descriptive text. As with the simpler embodiments, the carrier material is arranged with active areas 20 to capture the aromatic scents to be used in the tasting.
[0039] The embodiment shown in the FIG. 3 illustration also shows where the active areas can be separated by lines of perforation or demarcation 22 . These lines can be used to indicate to the taster which active area to be manipulated to produce the scent captured thereon or to enable separation of the card into one or more active areas in a group to be used in the methods of the present invention. The active areas can be individually selected or selected in groups to create a sub card arrangement suitable for use in the tasting method of the present invention. As it can be appreciated, the lines of demarcation or perforation could be bolded or colored in order to indicate groupings that the producer or other qualified taster indicated are the preferred groupings for selected wine varietals for instance. Alternatively, groupings reflective of malt toastings, coffee regions, or other things the taster would be prompted to consider together in the tasting would be assembled for presentation. As a further alternative, the scents could be arranged into groups with any one active area as a group of aromas selected to target a particular beverage, oil or other fine food. Thus, this invention builds on prior art which largely presents aromas in a singular fashion and contemplates mixtures of dominant, subtle and equal or unequal amounts to attempt to mirror the actual variety in nature and products being tasted using the apparatus and method of the present invention.
[0040] In an alternate embodiment, the cards may be arranged as shown in FIG. 4 where the pack of multiple cards 23 are bound on one end or side to form a book 40 . The binding 42 can be performed by any commonly available method such as compression with adhesive or punching and post connection such as a staple. The illustration in FIG. 4 shows how each card 11 of the card pack may be turned up or opened one at a time as in the first card shown 41 . As with previous embodiments, the active areas 20 are shown along with possible lines of demarcation or perforation 22 . In this manner a selection of cards for different beverages or multiple tasting events can be arranged.
[0041] FIG. 4 also shows the arrangement of the previously described logo area suitable for the logo or other marking of the purveyor of the product to be tasted. Alternatively, this region may be reserved for instructions for the use of the present invention in the manner intended by those producing the bound cards for use.
[0042] FIG. 5 shows yet another preferred embodiment in a circular shape 50 . The card is again divided into active areas 20 where an encapsulated material or other means for capture of the scents is provided. The lines of demarcation or perforation are also provided 52 , except that since this is a circular arrangement, they are arranged radially about the center of the card. An area of the card 51 is reserved to label the grouping. The examples given here are different wine varietals, but as it can be appreciated these labels could be replaced with the names of spirits, soft drinks, other beverages or oils or fine foods being tasted. In that case the scents captured in the active areas, 51 under the label would be appropriate to the beverage for which the tasting enhancing card was produced.
[0043] The embodiment shown in FIG. 5 could also be used if the shape desired corresponded to the tasting wheels that are used in guiding tasters of the many products described herein. In such a case, the tasting wheel would have the active areas or active material integrated to give tasters either a single use or multiple use experience enhancement using the methods described herein. The tasting wheel that integrates the active areas as shown in FIG. 5 is only exemplary of the many types of arrangements that could occur to group aromas for use in the methods of this invention.
[0044] Even though a circular arrangement does not have one side for binding, FIG. 5 also shows a binding area 53 where an extension of each card could be made to facilitate the binding of the circular cards in a manner previously disclosed. Although separate figures showing circular cards with only one active area or circular cards with multiple active areas shown in a single card are not illustrated in the drawings, it should be appreciated that such embodiments were contemplated for the present invention.
[0045] Additionally, the preferred embodiments shown herein are shown on flat carrier material of a minimal thickness, essentially a sheet that is cut into some geometric shapes such as the rectangles or circles shown here, it should be appreciated that any geometric shape could be chosen and the same methods used. It is within the contemplation of the present invention that the shape could be anything that can be cut, shaped or molded from a suitable carrier material, such as a specific logo shape, as a matter of example.
[0046] Further embodiments of the present invention include the specific aromas associated with various coffees and teas. These scents could be placed on the outside of coffee bags and cans to allow the consumer to either experience the aroma of the product he or she is buying or other products produced by the seller. For instance, tea aromas could be placed on tea bag “tabs” and boxes so the consumer would not have to open products to experience them, but could sample the aroma and use the vent on the coffee bag for example, to compare to the active area integrated into the product packaging. They could also sample the scents offered in conjunction with a vendor's offering of samples designed to promote the product. Additionally, a company could use them in the development of training materials designed to assist employees with the development of their palate and skills to promote the products.
[0047] Additionally, active areas could be captured on a shape or surface of something arranged in a three dimensional way, such as a conical or cylindrical arrangement for example. Because it is believed that this method of providing scents may be a useful compliment to commercial promotion of beverage products, it is contemplated that such shapes conducive to presentation on or integrated with disposable beverage containers and other accessories to the beverage experience would fall in the scope of the present invention. Such embodiments could be detachable or integrated into the serving or packaging apparatus to be used by tasters to get a sense as to whether or not they could discern the flavor the retailer was promoting, either at the time of consumption either by sample at the store, sample during tasting at home or other locations or anticipating a future sale. That way the taster could get a sense of that which he or she might try on the next trip into the store and have a useful artifact for use in enjoying the product in the manner intended or imbued by the producer of the product.
[0048] Getting back to the wine tasting experience, it is commonly known that wines produced in the United States growing regions, of which there are many, will have many different aromas. The best wines will often consist of a complex selection. The aromas may not be fixed during the useful life of the wine, but even though they are changing, at any one moment they are discernable to the consumer or taster. A connoisseur of wine knows it should not be rushed. The partaking of the aroma of the wine is a multiple sample event by the taster involved in the selection and appreciation of a particular wine. Accordingly the sampling of the scents presented by the present invention should receive a similar lengthy process to appreciate the selected groupings.
[0049] As previously discussed, in the case of wine, scotch or other beverage with unique properties, the properties of the growing region of the constituent materials of the beverage can be imbued in the taste of the beverage. In some circles of beverage appreciation this is often referred to as the terroir of the wine or beverage. Some define it as the ominous earthy flavor of the wine. Still others characterize it as the total natural physical environment of a winegrowing area, usually as an indication of superiority.
[0050] Still others assert that the term terrior was coined by the French and is thusly defined be a French vintner in The Vintner's Art by Johnson and Halliday as: “Terroir looks at all of the natural conditions which influence the biology of the vinestock and thus the composition of the grape itself. It is the coming together of the climate, the soil and the landscape. It is the combination of an infinite number of factors: hours of sunlight, slope and drainage, rainfall distribution, etc.”
[0051] Assuming the producer of the wine can be satisfied be has created a scent simulating the desired terroir for his region, it is within present invention described herein that it be presented on one or more of the active areas on the carrier material or other chosen method of presentation of the aromas. This terroir can be presented alone or with some of the other flavors asserted to be present in the promoted wine, for example.
[0052] Additionally the scents can be designed to promote “earthy” flavors. The “earthy” flavors can be imparted to the wine from the soil and water conditions which may predominate a region. In these cases, the terroir is dominated by one or more flavors imbued in the wine and the producer of the cards of the present inventions need only provide the exemplary scents on the active areas of the card or cards. An additional wine aroma that could be provided is a sweet or bitter chocolatiness that is present in a more complex wine.
[0053] As previously described, in the case of a scotch the flavors being promoted will be more of a type of smoke or toasted peat or, in the case of a beer, the hops. Whatever the beverage, oil, or fine food being promoted some scents are also being promoted and the use of such scents in the manner described in the various embodiments provided herein are all within the contemplation of the present invention.
[0054] When it comes to scotch, the aromas and flavors are almost as limitless as those in hot brewed beverages. The types range from regional flavor to the attributes gained from filtration of the beverage. When it comes to regions there are flavors and aromas such as: Islay (strong, peaty flavors; iodine and charcoal extremely forward); Highlands (drier, malty flavor, subtle differences with hints of spice); Speyside (fruitier, more complex flavors); Lowlands (very subtle, almost pale flavors, very light). Just as with wine, aging and barrel types can change the scotch as well. Aroma differences that can be picked up in tasting range from flavor strength in the charcoal and peat, fruit, cherry overtones, and much more.
[0055] There are several specific desirable flavor characteristics of coffee and the types of coffee that are associated with those characteristics that can be appreciated using the techniques of many of the embodiments of the present invention. They are associated with the different coffee types and roasting techniques applied to each coffee. Just as in the case of other beverages that retain remnants of the region in which they are grown, coffee too can retain such properties that can be discerned using the method and apparatus disclosed here. Some of the many taste and aroma attributes that can be ascertained are: Caramel—candy like or syrupy, typical of Colombian Supremo; Chocolate—an aftertaste similar to unsweetened chocolate or vanilla, typically found in Costa Rican and Colombian Supremo; Earthy—a soily characteristic, typical of Sumatran; Fragrant—an aromatic characteristic ranging from floral to spicy, typical of Costa Rican, Sumatra Mandheling and Kenyan; Fruity—an aromatic characteristic reminiscent of berries or citrus; Mellow—a round, smooth taste, typically lacking acid, typical of Colombian, Sumatra Mandheling, Whole Latta Java and Organic Mexican; Nutty—an aftertaste similar to roasted nuts, typical of Colombian and Organic Mexican; Spicy—a flavor and aroma reminiscent of spices typical of Guatemala Huehuetenango; Syrupy—strong, and rich, typical of Sumatran; Sweet—free of harshness, typical of Colombian; Wildness—an unusual, gamey flavor, typical of Sumatran; and Winey—an aftertaste reminiscent of well-matured wine, typical of Kenyan, Guatemalan. While these examples seem comprehensive and complete, it can be appreciated that since the human palate can discern many aromas and tastes, the combination of tastes and coffee types and roastings create an almost limitless combination of things that can be appreciated using the techniques disclosed herein.
[0056] Teas can have many flavors that can be appreciated in the manner described herein. Black teas such as Assam (India) are described as full-bodied with a strong malty taste, and a clear, dark red brew. Ceylon (Sri Lanka) is characterized as very aromatic, golden-amber brew with a rich, full astringent flavor that is sometimes described as “fruity” or “biscuity.” Darjeeling (India) can be either light and astringent with an amazing aroma and a green muscatel, sometimes “flowery” taste, or a darker, more round, less astringent, and “fruitier” full-bodied flavor. Both provide varying degrees of muscatel and wood flavors, along with a rich, golden-red brew. Keemun (China) has a subtle orchid aroma and a rich, red brew. Lapsang Souchong (China) is a dark tea with a distinct smoky fragrance and flavor. Nilgiri (India) gives a bright and smooth, well-rounded, “fruity” mellow flavor. Yunnan (China) has a brisk, rich, slightly peppery or “spicy” taste with a pronounced floral aroma.
[0057] Other less common teas give completely different flavor and aroma experiences that can be used in the matter described here. Darjeeling (India) is an excellent oolong with a flavor finish of unripened fruit. Formosa (Taiwan) possesses a delicate, “fruity,” sometimes “nutty” taste and a superb aroma. It can be appreciated that there are a great many other teas and aromas that are included in the types of aromas contemplated for use in the context of the present invention.
[0058] Olive oil or other aromatic oil can be comparatively tasted, just as a good wine, single malt scotch. Just as in the case of a good wine, the quality and taste of the oil is influenced by geographical factors such as land or region. Additionally, depending on the weather during a certain season, there can be good and bad years for the olives or other fruit used to make the oil being tasted. The quality depends of the good care of growers and producers. For example, there are olive oils with a strong and with a mild taste, some are spicy and others have a grass taste or taste a bit like nuts. No olive oil is the same. Although the disclosure here refers to olive oil, the present invention contemplates any oil made from naturally occurring ingredients that is used in cooking, sampled alone or otherwise enjoyed in a tasting experience.
[0059] An additional embodiment includes the tasting of chocolate. People have compared chocolate tasting to that of tasting fine wine. There are subtleties of flavor and tones that you can train yourself to appreciate. The flavors and aromas to be appreciated are influenced by the origin of the beans and the roasting process. Much like wine experts, chocolate experts can find an incredible array of scents and aromas. Some chocolate flavors include: burnt bread, nutty, spicy, fruity and each of these has a corresponding aroma that will enhance the taster's experience and ability to discern the flavor.
[0060] The process of tasting chocolate or other firm foods may include some warming, either with the person's hand or artificial means as a method of enhancing the aroma release. Thus, the active areas present on the apparatus in one embodiment of the invention include areas which are actively released via the introduction of hand warming heat or other artificial heat sources. Thus, the experience of tasting of the sample and comparison to the aroma from the active areas of the apparatus can be made in similar manner.
[0061] The present invention is useful for tasting of other fine foods, such as bread, for example. For instance, when tasting bread, the taster can be in search of different ingredients, such as rye or wheat, in his or her tasting experience. Subtle tones can be introduced with the aromatic oils described here, as well as using nuts and fruits to enhance the experience to the consumer or taster. The present invention has utility to a person tasting such exemplary fine foods to discern the flavors introduced by the maker of the product. Although bread is discussed in this embodiment, it is well within the contemplation of this invention that any fine food, such as breads, cakes, cookies or other product could benefit from use of the present invention in tasting the products. Or perhaps, not traditionally characterized fine foods, such as chili cook-offs, barbeques, and other traditionally common foods which are now the subject of gourmet contests and tastings could benefit. Therefore, it can be easily seen that the invention is not limited to the embodiments and examples of food types, aromas or taste suggestions presented here.
[0062] The embodiments previously described are oriented towards wine or spirit tasting, hot beverages, oils or other aromatic fine foods. As such, the aromatic scents to be used on the active areas are suggested to be fruits, woods, spices and other scents common to those beverage types. In the case of spirits, additional features such as smoke or peatiness are also highly useful to the tasting experience. Notwithstanding these example embodiments, the present invention is not limited to the named scents. Any scent that can be captured in an active area and can be associated with a beverage to be tasted can be used. For instance it is not outside the chance that a sarsaparilla or vanilla scent could be used to enhance the experience of a soda fountain visit or a top shelf carbonated beverage being sold to consumers. Since the present invention is about enhancing an experience through the use of suggestive scents on inexpensive carrier material, any combination of scents can be used.
[0063] Although the foregoing invention has been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. Accordingly, the present 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 equivalents of the appended claims.
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A method and apparatus to be employed in tasting processes for the purpose of characterizing the aromatic qualities of, for example, a wine, single malt scotch, hot brewed coffee or tea, chocolate, breads, food oils or similar type of aromatic product. The apparatus comprises a carrier material suitable for the support of aromatic scents of a variety found in wines, other beverages and other foods. The apparatus provides for the grouping of scents according to, for example, commonly found groupings of flavors in wine, distilled, brewed, hot brewed, food oils, chocolate or other aromatic food products. The apparatus provides for ease of separation of the individual scents or groups appropriate to the users current experience. The apparatus includes carrier material to which the aromatic scents are applied or to which the scents have been previously applied. The method of tasting using the aromatic scents comprises the use of one or more cards or subsets of the cards carrying the aromatic scents in a manner that results in a single scent or a grouping of scents appropriate to the beverage being consumed in a tasting. The vendors of many beverages have characterized the aroma of the product and one goal of the method is to enable the taster to discern the aromas of the beverage as part of his or her tasting experience.
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BACKGROUND OF THE INVENTION
Recycling of wastepaper is a key to survival of pulp and paper industries. The driving forces are limited by space for landfills, prevention of forests, and consumer pressure and legislation for recycled content in paper products. To produce good quality recycled paper requires, among other, the removal of ink from wastepapers which is commonly recognized as wastepaper deinking. Various technologies are available for doing this, which essentially consists of two steps: detaching ink from fiber and separating the suspended ink particles from the pulp slurry. For each step a variety of options are open; ink dispersion is usually achieved in the repulping step by the addition of deinking chemicals mostly in an alkaline medium, while ink separation is effected by screening, washing or flotation.
During recent years flexographic printing has been developed beyond the printing of pakaging materials and is an option for newspaper printing. Flexographic inks are water-based, providing printing and environmental benefits, but their presence reduce deinking quality by froth flotation and results in a more difficult effluent classification from washing devices. A very similar problem is encountered for inkjet-printed officewastes. Sales of inkjet printers are increasing rapidly due to more and more use of network computers, electronic mail etc. Pulping of papers printed in Deskjet printer, utilizing a liquid ink system, produces smaller particles than laser printers or photocopiers. In fact, on pulping, the deskjet-printing inks which are essentially dyes dissolved in water and glycols, totally disperse in aqueous repulping medium to produce a uniformly grey stock.
In practice segregation of wastepaper based on the type of printing is impossible. In most cases, wastepapers containing newsprints printed with offset and lithography are contaminated with flexo-printed newsprints. Similarly, officewastes containing toner based printed papers are contaminated with inkjet-printed officewastes. Although successful deinking technologies by froth flotation are available for offset and lithography printed newsprints, a flexography or inkjet printed paper contamination into other printed paper is causing severe deinking problem for the reason mentioned above.
The present invention simplifies the deinking of flexo- and inkjet-printed papers contaminated wastepaper mixtures using repulping and froth flotation processes by treating a repulped slurry in aqueous medium with a surface active polymer composition in presence or absence of a conventional surfactant to agglomerate small ink particles to a size range suitable for flotation and finally removing those agglomerated inks by creating air bubbles under constant agitation from the said repulped slurry.
SUMMARY OF THE INVENTION
It has been discovered that improved recyclability of wastepapers contaminated with flexography- and inkjet-printed papers is simply obtained by treating the wastepaper pulp, herein designated as repulped slurry, with a limited amount of a surface active polymer compound or a mixture of said compounds. Subjecting printed wastepapers contaminated with paper printed by flexographic and inkjet processes to shear forces under alkaline condition followed by treatment of this repulped secondary fiber slurry in an aqueous medium with a surface active polymer compound or mixture of compounds having a glass transition temperature ranging from 105° C. to 170° C. with or without a conventional surfactant, effects separation of the ink particles in minimum time even at a temperature below 35° C. By surface active polymer compound is meant an organic polymer, more specifically, a copolymer or terpolymer having at least one hydrophobic and one hydrophillic monomers, the polymer being adsorbed by the ink particles thereby facilitates repulsion of ink particles from fiber surface and agglomeration of the free inks. The polymeric compounds are specific compositions with the hydrophobic part being styrene and the hydrophillic part essentially contains an organic acid anhydride of the following structure: ##STR1##
More particularly, this invention deals with styrene-acid anhydride copolymer or terpolymer as a surface active polymer compound for treating repulped-secondary fiber. Henceforth the term surface active polymer compound and surface active polymer composition will be used interchangably to designate a single compound or a mixture of compounds. By terpolymer is meant an organic polymer containing three different monomer units in polymer chain and by treatment of repulped slurry is meant a process which is adopted to incorporate the surface active polymeric composition in an alkaline medium to facilitate separation of inks from secondary fiber. The said polymeric composition is beleived to produce the ink separation effect by agglomerating ink particles, perferably small ink particles of average particle size 10 microns and smaller by two different mechanisms: by charge neutralization of ink binder in an alkaline medium in presence of an aqueous solution of metal halide or by precipitating them in a midly alkaline medium as small solid particles followed by their agglomeration with other ink particles of similar size and preventing them from deposition on the pulp surface and, finally floating them out with controlled air flow and agitation. Regardless of the correct explanation, it is observed that the treatment of the pulp in alkaline medium with said surface active polymeric composition enhances the agglomeration of small ink particles to the size range of about 5 to 200 microns and then removes them from aqueous pulp slurry by froth flotation, thereby completely or partially eliminates a pulp washing stage usually required to remove small inks from repulped newsprints. It is in the aforesaid sense of being enhanced agglomeration and reducing the residual small ink particles below 5 microns in removing inks that deinking the secondary fiber is to be understood herein.
Perferred compositions of surface active polymer are those in which styrene and an organic acid anhydride are essential chemical components in a copolymer, more particularly, the acid anhydrides being 2,5 furandione, 2- dodecenyl succinic anhydride and 2-methylene succinic anhydride.
Preparation of the said surface active polymer wherein the composition is a styrene-2,5 furandione copolymer is described in the Eur. Pat. No. 27, 274, the disclosure of which is incorporated herein by reference. Novel compounds of surface active polymer in which the polymer being a mixture of a styrene-2,5 furandione copolymer and, a terpolymer of styrene, 2,5 furandione and a third comonomer are prepared by bulk copolymerization of the particular hydrophobe employed with 10 to 40 mole percents 2,5 furandione and 1 to 20 mole percents of a third comonomer chosen from 2-dodecenyl succinic anhydride, citraconic anhydride and 2-methylene succinic anhydride. This preparation may typically be accomplished as follows.
Two to four molar equivalents of styrene is heated with one to three molar equivalents of 2,5 furandione at a temperature ranging from about 60° C. to 90° C. with a catalytic amount of a free radical initiator such as laouryl peroxide, benzoyl peroxide in an inert liquid medium such as toluene, benzene, xylene. These catalysts and diluent systems and their amounts are well known and will not be described in detail. A typical concentration of catalyst and a preferred diluent system of this invention are particularly suitable for ink removal described in U.S. Pat. No.3,725, 360, the teachings of which are incorporated herein by reference. The heating of styrene and 2,5 furandione is continued for 10 to 60 minutes in oxygen free atmosphere in order to initiate the reaction between styrene and 2,5 succinic anhydride, as evidenced by a marginal increase in the viscosity of solution, and then about 0.1 to 1.5 mole equivalents of a third comonomer such as 2-dodecenyl succinic anhydride is added. The reaction may be advantageously carried out at slight pressure, for example, at about 5 pounds per square inch pressure in a glass apparatus. The preferred temperature during the third comonomer addition is above 75° C. Temperature below 75° C. may be used, but the reaction is quite slow. After addition of a third comonomer the reaction is continued for another 1 to 3 hours. When the required extent of reaction is achieved, as determined by the viscosity of solution, the batch is then stripped to remove liquid diluent, the product is recovered first by dissolving in sufficient amount of acetone followed by precipitating it in water. The unique property of these surface active polymers is that they are soluble in alkali.
It should be noted that the said surface active polymer compositions with good ink agglomeration and sufficient frothing character herein disclosed are obtainable only when 2-dodecenyl succinic anhydride is added as a third comonomer during the reaction. No addition of 2-dodecenyl succinic anhydride leads to products which are efficient in ink agglomeration but do not possess sufficient frothing ability to remove most of the agglomerated inks from aqueous pulp slurry. Such copolymers with a third comonomer other than 2-dodecenyl succinic anhydride or without any third comonomer are also suitable for use as ink agglomerating agents in accordance to this invention are styrene-acid anhydride copolymers or terpolymers.
The styrene-acid anhydride copolymer is one having a styrene content at least about 50 mole percents, preferably from about 60 to 80 mole percents and a glass transition temperature in the range from about 105° C. to about 170° C., preferably from about 110° C. to about 160° C. Preferred styrene-acid anhydride copolymers and terpolymers are styrenecitraconic anhydride copolymer, styrene-2,5 furandione-2 methylene succinic anhydride terpolymer, styrene-2,5 furandione-citraconic anhydride terpolymer, styrene-2,5 furandione copolymer, the later being particularly preferred. The styrene-acid anhydride copolymers and terpolymers other than those containing 2-dodecenyl succinic anhydride can be prepared using techniques well known to the art. The preferred systems are alternating and random copolymers as described by Moore in I.E.C. Prod. R.D. on page 315, V-25, 1986 and described as random copolymers on pages 359, 364 and 390, Trivedi and Culbertson, Maleic anhydride, Plenum Press, New York, 1982. See also Czech CS. Pat. No. 247, 037 for preparation of block copolymers.
More particularly this invention comprises the process to incorporate the said surface active polymer composition in a wastepaper repulped-slurry in an aqueous alkaline medium in order to agglomerate free small inks, preferably small inks generated from repulping of flexogarphic newsprints and inkjet-printed officewastes containing waste printed paper mixtures and then separating the agglomerated inks in the size range of about 5 to 200 microns from the pulp slurry by froth flotation.
The treatment of waste printed paper is preceeded by an alkaline repulping step. Repulping of secondary fiber may be effected using any conventional process and apparatus. Typically waste paper is subjected to mechanical shearing in a so called high consistency laboratory pulper. The function of a pulper in waste paper recycling operations is to defiber the paper and detach ink particles from fibers. The pulper produces a high consistency pulp slurry herein designated as "repulped slurry", when waste printed paper is agitated with a high speed rotor in an aqueous alkaline medium. The consistency of repulped slurry typically varies from about 5 to 20 percent and usually from about 7 to 13 percents by weight of paper fiber basis dry weight of waste printed paper relative to the total weight of the slurry. The pH of the aqueous alkaline medium ranges from about 7.5 to about 11.5, more frequently the pH is maintained in the vicinity of about 8.0 to 10.5. Repulping chemicals may be added to the pulper. The reason for adding chemicals to the pulper is to assist in the easy release of the undesirable materials such as ink and sticikes, from waste paper and to make these undesirable materials accessible for separation by conventional deinking processes such as screening, flotation and washing. The principal repulping chemicals used in this invention are: sodium hydroxide, sodium silicate, chelating agent and hydrogen peroxide. A typical repulping chemical composition contains 1.0 to 4.0 percent sodium silicate, 0.5 to 2.0 percent hydrogen peroxide, 0.1 to 0.25 percent chelant such as diethylenetriamine-pentaacetic acid (DTPA), sodium hydroxide as required to adjust the pH from 7.5 to 11.5. In some cases dilute hydrochloric acid is also used for pH adjustment depending on the resulting pH of the pulp slurry after addition of all pulping chemicals except sodium hydroxide. The temperature of the pulper is held in the range of about 25° C. to 60° C. A temperature above 60° C. may be used with an undesirable loss in mechanical shear during the repulping process. The time of repulping may be from about 10 to 30 minutes. Usually, a repulping time of about 15 to 25 minutes is advantageous.
In most cases, the repulped slurry contains free ink particles ranging from about 0.1 micron to about 200 microns or more. It has been discovered that the treatment of a diluted repulped slurry with a surface active polymer composition surprisingly improved the agglomeration of small ink particles ranging from about 0.1 micron to about 10 microns. A subsequent flotation of the aforesaid treated slurry in a conventional flotation cell has readily removed the inks from aqueous slurry. Since the invention process is particularly applicable to waste printed paper contaminated with papers printed with flexographic and inkjet processes, such ink removal process may also be applied for flotation deinking of flexo- or inkjet-printed wastepapers alone.
Flotation of the repulped fiber may be effected using any conventional process and apparatus. Typically repulped slurry from pulper is treated in a flotation cell under controlled agitation and air flow. The choise of an agitator, an agitator speed and an air flow rate are well known art and will not be discussed here in detail. The pulp consistency in the flotation cell may be varied from about 0.2 percent to about 1.2 percent of dry pulp in relation to the total weight of slurry. More preferred pulp consistency is from about 0.3 percent to about 0.8 percent by weight. Treating the low consistency pulp with an aqueous medium containing a surface active polymer composition may be conveniently effected in a flotation cell by simply adding the surface active polymer composition to the repulped slurry. The pH of the fiber slurry may range from about 7.5 to about 10.5. More preferred pH range is from about 8.0 to about 9.5. The pH can be adjusted by addition of an acid or a base as required.
All alkali soluble copolymers and terpolymers herein described as surface active polymer compunds may be incorporated in the flotation cell as their alkali metal salts more preferably as their sodium salts. In their anionic form, an aqueous solution of metal chloride is also added to the pulp slurry together with the surface active polymer composition. Generally, calcium chloride, potassium chloride and magnesium chloride are used as metal chlorides but calcium chloride dihydrate is preferred.
The amount of the said surface active polymer composition used typically ranges from about 0.3 percent to about 2.5 percent and usually about 0.5 percent to about 2.0 percent on dry basis weight of waste printed paper in repulped slurry. The amount of metal chloride is usually about the same as the said surface active polymer composition.
Another suitable method to introduce the said surface active polymer compositions which are insoluble in aqueous alkaline solution having a pH less than 10.5, in an aqueous pulp slurry in a flotation cell is in the form of a water-based dispersion. A water-based dispersion of a surface active polymer composition may be prepared by first dissolving the solid polymer in a water insoluble organic solvent in a concentration range of about 3 percent to about 8 percent by weight of the solvent and then dispersing this polymeric solution in water. The organic solvents which are suitable for this application are esters and ethers, more particularly phthalate and adipate type esters such as dioctyl phthalate, dibutyl adipate. The water is the domimant phase in the aqueous dispersion of the said polymeric solution. Preferred ratio is 40 parts of polymeric solution to 60 parts of water by weight. Water based dispersion may be suitably made by stirring the mixture at high speed with a propeller in presence of a small amount of a dispersant. A sodium salt of benzene napthyl sulfonate in the concentration range of about 0.05 to 0.1 percent of dispersion may be used as a dispersant. It should be noted that the use of this water based dispersion is limited to an aqueous pulp slurry having pH less than about 10.5.
Because removing the ink particles as much as possible is most desirable in the deinking of repulped secondary fibers, an important feature of secondary pulp recycling is agglomeration of small ink particles having particle size below 5 microns. In general, water-based dispersion of surface active polymer composition may be employed for agglomerating small inks in practicing the present invention. The water-based dispersion is believed to produce the aforesaid effect by precipitating the dispersed surface active polymer as solid particles of small sizes on their introduction to an aqueous pulp slurry having pH about 10 or less and once precipitates promoting agglomeration of free small ink particles.
The introduction of a surface active polymer composition in the form of a water-based dispersion in flotation cell improves deinking for repulped secondary fiber, more preferably for repulped fiber containing xerography, laser printed papers and old newsprints (ONP). The function of a water insoluble solvent is beleived to be the swelling of ink-fiber interface of fused large ink particles and breaking them to small particles suitable for agglomeration and flotation. The amount of water-based dispersion typically ranges from about 0.1 percent to about 2.0 percent by weight of surface active polymer composition based on dry basis weight of pulp in aqueous slurry.
Of course, the aqueous slurry in flotation cell may contain other additives commonly used in flotation deinking operation. Examples of such are chelating agents, frothers, conventional deinking agents, defomers etc. Nonionic or anionic deinking agents may be employed together with water-based dispersion in the practice of this invention. Because of the low foaming nature of these solid surface active polymeric particles in pulp slurry, usually a frothing agent is used to float out the agglomerated ink particles from aqueous medium. Examples of satisfactory frothing agents include those materials described as `polyalkylene oxide block copolymers` on pages 300-37 1, Schick, Nonionic Surfactants,Marcel Dekker, Inc., New York, 1966. See also JP. Pat. No. 05, 51 887. Conventional fatty acid soaps and other nonionic surfactants may also be used as frothing agents.
Using surfactant to provide sufficient foaming ability is a well known art and surfactant compositions of secondary fiber recyclates provide a wide selection from which to choose a frothing agent for practicing the present invention. Usually the amount of frothing agents is small and typically ranges from about 0.01 percent to about 0.1 percent by weight based on dry pulp for nonionic type frothing agents and ranges from about 0.1 percent to about 0.5 percent by weight on dry pulp for fatty acid soap type frothers. A chelating agent may be introduced in the pulp slurry immediately after flotation process. The amount of chelating agent may range from about 0.1 percent to about 2.0 percent of the dry basis weight of pulp.
The alkaline salts and the water-based dispersions of surface active polymeric composition disclosed in this invention may be used for deinking of waste papers printed by lithography, offset, flexography processes and office wastes processed by xerography, laserjet and deskjet printers. More preferentially, alkaline metal salts of said surface active polymer compositions may be used to deink waste printed papers contaminated with significant amount of flexo and inkjet printed papers and the water- based dispersions can be more suitably used for mixture of officewastes and old newsprints (ONP) including flexo printed newsprints. The officewastes in this invention include xerography, laser and inkjet printed papers.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As illustrative of deinked waste printed-paper composition comprising of both newsprints and officewastes, wastepapers with two separate compositions were repulped in a laboratory high consistency pulper. About 920 grams of waste printed papers were torn into about 3-inch squares and charged in a laboratory pulper containing appropriate amount of warm water to adjust the required consistency. The repulping was carried out in alkaline medium of pH 10.5 by adding 2.0 percent sodium silicate, 3.0 percent hydrogen peroxide, 0.1 percent chelant-diethylenetriaminepentaacetic acid and sodium hydroxide in required quantity to adjust the pH. In these embodiments and embodiments hereafter, all weights and concentrations are based on weight percent of dry basis weight of paper unless otherwise specified. The repulping was carried out by mixing the composition in the pulper for about 20 minutes with a rotor speed of about 1500 revolutions per minute. The temperature of the pulp slurry was about 45° C. These two repulped compositions before treatment with surface active polymer composition of styrene-acid anhydride copolymer or terpolymer in a flotation cell are designated as `H-1 and H-2 Repulped Stocks` as in given below.
______________________________________H-1 and H-2 REPULPED STOCKS Repulped stock H-1 H-2 (wt. %) (wt. %)______________________________________OLD NEWSPRINTFlexographic 30 30Offset 70 40OFFICEWASTEHP-laserjet NIL 10HP-deskjet NIL 10Photocopy NIL 10______________________________________
The wastepapers used in these examples of repulped stocks are old newsprints printed by offset and water-based flexographic processes. The officewastes used in these examples were 21.6 cm×27.9 cm sheets printed on one side with uniform alfabetic text generated by HP-laserjet and HP-deskjet printers. The laserjet printed text was photocopied on one side of a white paper of same size using SAVIN 7500 copier employing a toner. The pulp consistencies in the repulped stocks were 8 percent and 13 percent for H-1 and H-2 repulped stocks respectively.
EXAMPLE I
The H-1 and H-2 repulped stocks are made into handsheets by passing through a Handsheet machine according to TAPPI test method T-272-om-92 and through a Buchner funnel according to TAPPI method T-218-om-92. These two methods were used to justify the effect of small ink particles on deinking. It is already understood that TAPPI method T-218-om-92 is more suitable for brightness measurement of stocks containing large amount of small ink particles wherein a filter paper of 2.5 microns pore size was used in the present invention to make handsheets. On the other hand, the handsheets making in accordance with TAPPI method T-272-om-92 was performed using a 140 mesh screen. The handsheets made according to Tappi methods T-218-om-92 and T-272-om-92 from control repulped stock H-1 had average brightnesses of 39-40% ISO and 42-43% ISO respectively determined in accordance with the Technical Association of Pulp and Paper Industry (TAPPI) method T-217. The H-2 repulped control handsheets made according to Tappi test method T-272-om-92 had an average brightness of 54% ISO determined in accordance with TAPPI method T-217 and an average ink particles surface area of 0.0174 meter square per meter square of paper as determined by an image analyzer `Ultimage version 2.1` coupled with an optical microscope, Carl Zeiss, Germany and determined on handsheets with 60 grams per meter square basis weight.
EXAMPLE II
This example illustrates the preparation of styrene-2,5 furandione- 2, dodecenyl anhydride terpolymer composition followed by deinking of repulped stocks H-1 and H-2 as described in Example I with this prepared surface active polymer composition in accordance with one embodiment of the treatment of this invention.
One hundred and four parts of approximately 1 molar equivalent of a commercial grade freshly distilled styrene, was charged in a flask equipped with a stirring system. About 1600 milliliters of benzene and thirty seven parts of commercial grade 2,5-furandione was added in the flask and the total charge was heated at 60° C. for 10 minutes to dissolve all 2,5-furandione. Then about 0.85 part by weight of freshly crystallized benzoyl peroxide was added to the flask in an oxygen free atmosphere and a positive pressure of about 5 pounds per square inch was maintained in the flask. The temperature of the mixture was raised to about 75° C. and held for about 1 hour until the reaction between styrene and 2,5-furandione started as evident by an increase in the turbidity of the solution. Twenty parts of approximately 0.1 molar equivalent of a commercial grade 2-dodecenyl succinic anhydride was added to the mixture. Reaction was carried out for another 90 minutes maintaining the mixture temperature in the range of 75 to 80° C. The batch was then cooled to 60° C., benzene was stripped off and polymer was precipitated from acetone solution by adding water. The aforesaid synthesized product, a mixture of terpolymer of styrene-2,5 furandione-2 dodecenyl succinic anhydride having a glass transition temperature of about 137° C. and a copolymer of styrene-2,5 furandione having glass transition temperature of about 160° C., herein designated as `terpolymer composition` was used to deink repulped stocks H-1 and H-2 . The sodium salt of this terpolymer composition was made by dissolving the product in aqueous sodium hydroxide solution.
A number of flotation experiments were made using varying consistency of repulped slurries H-1 and H-2 (1). The treatment of varing weight percent of prepared sodium salt of terpolymer composition (2) with repulped slurries was made in a laboratory open-Top Leeds cell type flotation cell. With minor differences, the treatment procedure used in each experiment was as follows.
Varying repulped slurry consistencies from about 0.3 to 1.0 percent by weight of dry pulp was made by diluting the stock H-1 and H-2 as described in Example I by adding required amount of warm water with constant stirring and then adjusting the pH of the diluted pulp slurry to a given pH (3). The pH of pulp slurry was varied from about 8.0 to about 10.0. Varying amounts of the said terpolymer composition were added in the form of a sodium salt to provide from 0.1 to 2.0 percent by weight of terpolymer composition based on dry pulp together with an aqueous solution of calcium chloride of about equal amount to terpolymer composition by weight of calcium chloride. The temperature of the slurry was adjusted from about 30° C. to about 60° C. (5). This pulp slurry containing the said terpolymer composition was then treated by mixing at high speed of about 1200 revolutions per minute for about 1 to 5 minutes (4). This treatment period is designated herein as `conditioning period`.
Air was introduced in the flotation cell to remove agglomerated inks after conditioning of repulped slurry. The air flow rate was about 3000 milliliters per minute. Flotation was carried out for about 10 minutes and then air flow was stopped. About 0.3 percent of chelant-diethylenetriamine-pentaacetic acid by weight of dry pulp was added to the flotation cell and slurry was agitated for another one minute. The pH of the resulting deinked pulp slurry was then adjusted to 8.5 and slurry is made into handsheets by passing through a Handsheet machine according to TAPPI test method T-272-om-92 and through a Buchner funnel according to TAPPI method T-218-om-92 as described in Example I. The brightness of the handsheets were determined in accordance with the TAPPI method and residual ink surface area was determined by image analysis mentioned in Example I. The Table I summarizes the results of seven experiments. It is evident that a brightness gain of about 8 points is achieved.
EXAMPLE III
This example, illustrates treatment of repulped stocks H- 1 and H-2 of Example I in accordance with another embodiment of this invention, using a surface active polymer composition having a glass transition temperature of about 162° C. comprises of sodium salt of styrene-2,5 furandione copolymer prepared by solubilizing 50 parts of the said copolymer in 1200 milliliters of 0.5 molal sodium hydroxide. The solubilization was carried out under constant stirring for 3 hours at about 45° C. Treatment of repulped stocks and then flotation of agglomerated inks were carried out in a similar fashion as described in Example II, except that a sodium salt of styrene-2,5 furandione copolymer was used for pulp treatment instead of a terpolymer composition. Varying amounts of sodium salt of styrene-2,5 furandione copolymer together with an aqueous solution of calcium chloride of about equal amount of the copolymer composition by weight of calcium chloride was added in the pulp slurry in flotation cell. The % ISO brightness and ink surface area of deinked pulp are given in Table II. A marked improvement in % ISO brightness and a decrease in the ink surface area is evident after treatment.
EXAMPLE IV
As illustrative of another embodiment, a surface active polymer composition containing an anionic frothing agent was prepared by heating 50 parts by weight of styrene-2,5 furandione copolymer having glass transition temperature of about 128° C. with 10 parts of by weight of sodium oleate in 1200 milliliters of 0.5 molar sodium hydroxide solution under constant stirring. The mixing was carried out for about 3 hours at a temperature of about 45° C. Six series of experiments were made using this alkaline solution of surface active polymer composition for treating the repulped stocks H-1 and H-2 of Example I with varying pulp consistency and then florating out the agglomerated inks from the slurry by repeating the procedure of Example II. The amount of the aforesaid alkaline solution of surface active polymer composition added to the repulped stocks contained 1.6 weight percent by weight of styrene-2,5 furandione copolymer on dry basis weight of pulp in the slurry. An aqueous solution of calcium chloride containing 2.0 percent by weight of calcium chloride on dry basis weight of pulp in the slurry was also added to the pulp slurry before conditioning period. The pH of the slurry was adjusted to about 8.5 in each experiment and the pulp slurry temperature was about 45° C. for all experiments. A flotation time of about 10 minutes was used for all experiments. Handsheets made from deinked pulps after flotation of treated repulped stocks H-1 and H-2 had brightness values and ink surface areas as shown in Table III.
The data shows that the treated repulped-secondary fiber has improved brightness even with a smaller concentration of styrene-2,5 furandione copolymer in a short conditioning time.
EXAMPLE V
In still another embodiment, a surface active polymer composition containing a nonionic frothing agent was prepared by heating 100 parts of styrene-2,5 furandione copolymer having a glass transition temperature of about 128° C. with 2.5 parts of DI 600 (product of Kao Corp.) in 1200 milliliters of 1 molal sodium hydroxide solution under constant stirring. The mixing was carried out for about 3 hours at a temperature of about 55° C. Four runs were made using this alkaline solution of surface active polymer composition for treating the repulped stocks H-1 and H-2 of Example I and then flotating the agglomerated inks by repeating the procedure of Example II. The amount of the aforesaid alkaline solution of surface active polymer composition added to the repulped stocks contained 1.6 weight percent by weight of styrene-2,5 furandione copolymer on dry basis weight of pulp in the slurry. An aqueous solution of calcium chloride containing 2.0 percent by weight of calcium chloride on dry basis weight of waste printed paper in pulp slurry was also added to the flotation cell before conditioning period. The pH of the slurry was adjusted to about 8.5 in each experiment and the pulp slurry temperature was about 45° C. for all experiments. A flotation time of about 10 minutes was used in each set of experimental run. Handsheets made from deinked pulps after flotation of treated repulped stocks H-1 and H-2 had brightness values and ink surface areas as shown in Table IV. A recycled fiber with ISO brightness of about 54% had been obtained for newsprints contaminated with about 30% by weight of flexo-printed newspaper.
EXAMPLE VI
The following illustrate embodiments of the invention in which a surface active polymer, styrene-2,5 furandione copolymer having a glass transition temperature 147° C. had been treated with the repulped stocks H-2 as in Example I in a flotation cell in the form of a water-based dispersion.
The water-based dispersion of the aforesaid copolymer was prepared by dissolving 80 parts of the copolymer in 1000 milliliters of dioctyl phthalate. The dissolution had been carried out at about 60° C. under constant stirring for about 6 hours. Fourty parts of this polymer solution was then dispersed in 60 parts of water by high speed mixing of the composition with a propeller. About 0.01 part of sodium salt of dodecylbezenesulfonic acid by 100 parts of the copolymer was added as a dispersant.
Treatment of the repulped H-2 stock as described in Example I had been carried out in a flotation cell by adding a varying amount of the said water-based dispersion at about 60 ° C. to the repulped slurry with a varying pulp consistency and then mixing the slurry for about 15 minutes. About 1.0 percent by weight of sodium oleate by weight of dry pulp and about same amount of calcium chloride in the form of an aqueous solution had been added to the pulp slurry. The pH of the repulped slurry was adjusted to about 8.5 and the slurry was conditioned for about 2 minutes and then flotation of the agglomerated ink particles were carried out in the same fashion as described in Example II. Results of the brightness values of the handsheets made from deinked pulp and the ink surface areas on the handsheets are summarized in Table V. The present treatment process, which by comparative evaluation with other standard treatment process known to the prior art, serve to prove the superiority of our novel pulp treatment process. Thus, in a separate treatment process a conventional ink collector system known to the prior art, comprises of about 1 percent by weight of sodium oleate and 1 percent by weight of calcium chloride in the form of an aqueous solution, had been used to treat repuled stock H-2 in a similar fashion as described above without any addition of a water-based dispersion of styrene-2,5 furandione copolymer. The resulting brightness value and ink particle surface area of this standard treatment process is also given in Table V for comparison only and is outside the teachings of the present invention.
In Table V, data illustrates clearly the relative superiority of our novel treatment process of repulped slurry with water-based dispersion of ester solution of styrene-2,5 furandione copolymer with regard to its improved brightness and decreased surface area of the ink particles. All the treatment processes involving water-based dispersion, namely, experiments Nos. E1 and E2, are in accordance with present invention are herein defined and claimed.
All of these treatment processes, it will be noted, are acceptable when measured against the standards described in Example I and experiment no. E3 of Example V.
TABLE I______________________________________Exp.series Stock 1 2 3 4 5 6 7 8______________________________________A1 H-1 0.3 1.5 8.5 1 30 50.4 51.1 --A2 H-1 0.5 1.0 10 2 45 46.9 48.5 --A3 H-1 1.0 0.1 8.5 5 60 42.7 45.4 --A4 H-1 0.5 2.0 8.5 2 45 49.7 52.2 --A5 H-2 0.3 2.0 8.0 2 45 -- 63.5 0.0032A6 H-2 0.5 1.0 10 2 45 -- 59.7 0.0045A7 H-2 1.0 1.5 8.0 5 60 -- 58.2 0.0092______________________________________ 1 is the consistency of repured slurry in wt. % of dry waste printed paper, 2 is the wt. % of terpolymer composition based on dry waste printed paper 3 is the pH of the repulped slurry in flotation cell, 4 is the conditioning time, 5 is the temperature of repuled slurry in flotation cell, 6 is the brightness of the handsheet in % ISO (TAPPI method T218), 7 Is the brightness of the handsheet in % ISO (TAPPI method T272) and 8 is the ink surface area on the handsheet in M.sup.2 /M.sup.2 of paper.
TABLE II______________________________________Exp.*series Stock 1 2 3 4 5 6 7 8______________________________________B1 H-1 0.3 2.0 8.5 1 45 48.4 50.3 --B2 H-1 0.5 0.8 10 2 45 45.7 48.1 --B3 H-1 1.0 1.5 8.5 5 60 44.2 46.6 --B4 H- 2 0.3 2.0 8.0 2 45 -- 61.7 0.0032B5 H-2 0.5 1.0 10 2 45 -- 58.3 0.0049B6 H-2 1.0 0.5 8.0 5 60 -- 56.1 0.0131______________________________________ *all number abbreviations are the same as in Table I.
TABLE III______________________________________Exp. series* Stocks 1 4 6 7 8______________________________________C1 H-1 0.3 1 52.3 53.9 --C2 H-1 0.5 1.5 48.6 51.3 --C3 H-1 1.0 2 44.8 48.1 --C4C5 H-2 0.3 1 -- 63.8 0.0029C6 H-2 0.5 2 -- 61.9 0.0041C7 H-2 1.0 3 -- 58.7 0.0046______________________________________ *all number abbreviations are the same as in Table I.
TAaLE IV______________________________________Exp. series* Stocks 1 4 6 7 8______________________________________D1 H-1 0.3 2 52.3 54.3 --D2 H-1 0.8 3 46.6 50.1 --D5 H-2 0.3 2 -- 63.4 0.0031D6 H-2 0.8 3 -- 59.4 0.0046______________________________________ *all abbreviations are the same as in Table I.
TABLE V______________________________________Exp. series* Treatment 1 4 6 7______________________________________E1 Dispersion 0.5 2 60.2 0.0043E2 Dispersion 1.0 5 59.6 0.0045E3 Sodium 0.5 2 56.7 0.0125 oleate______________________________________ *all number abbreviations are the same as in Table I.
Although the invention has been illustrated by typical examples, it is not limited thereto. Changes and modifications of the examples, of the invention herein chosen for the purposes of disclosure can be made which do not constitute departure from file spirit and scope of the invention.
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This invention relates to a treatment process of wastepaper for making printing grade paper from newsprints and officewastes using surface active polymer composition including a novel surface active terpolymer. In particular, the invention is concerned with a process for removing ink from an aqueous pulp slurry by treating the pulp with a surface active polymer composing of two to three comonomers in which at least one is a hydrophobe and another is a hydrophil, having a glass transition temperature ranging from about 105° C. to about 170° C., alkali metal salts of the said surface active polymer and the combination of the said surface active polymer with a fatty oil alkoxy derivative or fatty acid soaps.
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BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a control device as well as to a method for controlling the operation of motor vehicle components, especially of an internal combustion engine or transmission of a motor vehicle, in accordance with the preamble of claim 1 or 8 .
Such control devices and control methods are known per se (DE 40 04 427 A1, DE 42 31 432 A1, DE 44 38 714 A1) and are implemented in such systems by an electronic module usually referred to a as “control device”, in which a wide variety of control and/or monitoring functions for electronic or electrical components are grouped together. The history of constantly increasing demands regarding the functionality of such control devices has led to the desired functions largely being implemented nowadays by the use of a microcontroller. The term “microcontroller” in this case refers to an electronic programmable control device, typically having a CPU, RAM, ROM and I/O ports like a PC, but unlike a PC, being designed for a very specific application.
The components to be controlled by the control device, in addition to components located in the immediate vicinity of the internal combustion engine, such as a fuel pump, a choke valve, a fuel injector or a Lambda probe, also include other components of the motor vehicle. On the input side sensor signals or measured values needed for control are entered into the control device, e.g. relating to the crankshaft speed and position, the motor temperature, the inlet air temperature and volume, the position of the gas pedal etc. This list of components to be sensed and controlled is by no means definitive and serves merely to illustrate the plurality of conceivable functions of a control device.
Since the technology of a microcontroller or its I/O ports are generally not suitable for direct activation of the motor vehicle components of interest here, these components are usually controlled by output stages assigned to them, which for this purpose receive on their input side corresponding control signals of the microcontroller and on their output side provide the voltages or currents necessary for activating and deactivating the components, for example the charge and discharge current of a piezoactuated fuel injection valve. Especially as regards the functions which are critical for safety, the output stages are usually supplied with what is referred to as a release signal in addition to the control signals, and depending on the release state, this signal is used to signal a disabling or enabling of the release. This release, independent of the actual activation output stage, is provided by a release control device which is integrated with known controllers into a monitoring device which monitors the correct operation of the microcontroller, in order to take suitable action in the case of an error, for example to reset the microcontroller and/or to set one or more release signals to the first release signal state, with which each assigned output stage is disabled or switched off.
Such a monitoring device, often referred to as a “watchdog” can in such cases be integrated into the microcontroller or can be arranged separately from this. The function of such a watchdog is for example based on this device setting tasks for the microcontroller from time to time and, on the basis of the results returned by the microcontroller, establishing whether the microcontroller is operating correctly or not.
The electrical connections which are provided for transmission of release signals to the relevant output stages (deactivation paths), can take the form of multiple (redundant) connections to provide increased safety. Furthermore the ability to deactivate output stages by means of the digital release signals can be checked on the basis of a self test in the inactive system state, i.e. at least once per usage cycle. An incorrect deviation of the operating conditions from the allowed range, especially any type of fault within the microcontroller, including errors caused by faulty software are however the most probable in the active operation of the system.
If an error occurs in the active operation of the system which should have been detected by the watchdog device, and output stages should have been switched by means of the digital release signal into a state defined as “safe”, shortcomings anise in practice with the known control devices however.
In particular it can occur, in the event of an error, that a release signal is not put into a first signal state which causes the assigned output stage to be disabled, because the error is in the watchdog device itself or in its release control unit or the error adversely affects the correct function of these latter devices.
To resolve this problem of the often inadequate safety of the monitoring, it is conceivable to further increase the redundancy of the monitoring and to make it more robust in respect of errors which are caused by an overvoltage (e.g. by a short circuit). Such solutions are however expensive, under some circumstances reduce reliability in normal operation, and may in practice again be restricted to more or less specific error cases for which they are designed.
SUMMARY OF THE INVENTION
It is thus the object of the present invention to provide a control device as well as a method for controlling the operation of an internal combustion engine of a motor vehicle with improved behavior in the event of an error.
This object is achieved by a control device as claimed in claim 1 or an engine control method as claimed in claim 8 . The independent claims relate to advantageous developments of the invention.
The inventive control device is characterized by a modulation device for periodic modulation of the release signal provided by the release control device and an evaluation device for analyzing the release signal supplied to the output stage with regard to the periodic modulation and for putting the output stage into a predefined error state if the periodic modulation does not occur.
By the modulation of the release signal provided by the release control device and the evaluation of the release signal fed in the direction of the output stage as regards this modulation it is ensured that an error which is present as a result of an error in the region of the release signal generation and/or release signal transmission is reliably detected (on the basis of the absence of the modulation). The output stage involved can thus reliably be placed even in such an event into a predetermined error state, which is provided for example as a deactivation state or reset state of the output stage.
In particular errors in which the release signal statically (permanently) assumes one specific state of the two release signal states can reliably and explicitly be identified as an error.
The invention thus implements a “fail-safe deactivation path” which increases the safety of the system.
In a preferred embodiment the modulation device comprises:
a pulse generator for generating a periodic sequence of modulation pulses, and a modulation stage downstream from the release control device into which the release signal from the release control device as well as the periodic sequence of modulation pulses from the pulse generator are entered and which, at least if the second release signal state is present, inverts the release signal for the duration of one modulation pulse in each case.
In this case the evaluation device can comprise an evaluation stage upstream from the output stage into which the release signal from the modulation stage is entered and which analyzes the entered release signal in respect of the presence of the inverted release signal sections in accordance with the modulation pulse sequence, and if these inverted release signal sections are present, passes the release signal on to the output stage, and if these inverted release signal sections are not present, puts the output stage into the predetermined error state.
In a preferred embodiment the evaluation device is provided in such a form, that on a transition of the entered release signal from one release signal state into the other, the release signal passed on to the output stage is only allowed to be transferred if the evaluation device can exclude the fact that the transition of the input signal has merely taken place as a result of the modulation, meaning that it was not a triggered by a corresponding transition of the release signal provided by the release signal device. This checking by the evaluation device before a changeover of the release signal state output requires a certain amount of time under some circumstances which in practice however is often acceptable. Alternatively this checking by the evaluation device associated as a rule with a delay is only provided if the release signal changes over from the first into the second or from the second into the first release signal state.
Preferably the evaluation device is embodied such that the modulation of the entered release signal is removed, i.e. the release signal output to the output stage contains no such modulation. It is also conceivable however to leave the modulation in the release signal if in the timing of the signal relatively short-duration modulation sections did not significantly adversely affect the activation of the output stage involved or if the modulation is filtered out in the output stage.
The pulse generator can be provided integrated together with the modulation stage, e.g. in the watchdog device, that is especially together with the other circuit parts of the watchdog device in a common integrated circuit which may if necessary also include the microcontroller.
Preferably the release control device is integrated into a monitoring device (such as for example watchdog mentioned at the start), which monitors the correct operation of the microcontroller and only provides the release signal in the second release signal state on determining correct operation. In many applications, if for example a commercially-available microcontroller chip is to be used, it is of advantage to provide the monitoring device including the release control device and including at least a part of the modulation device (e.g. without the pulse generator described below) in a common integrated circuit which is arranged separately from the microcontroller chip in an electronic module (control device).
Preferably the evaluation device is integrated into the output stage device containing the output stage, that is especially embodied in a common integrated circuit. Quite apart from the advantage of a low-cost implementation of the evaluation device, e.g. without additional electronic components, a further, quite significant advantage is produced from this in practice in connection with an overvoltage monitoring or in connection with the “fail-safe” behavior of the system as a whole in the specific error case of an overvoltage.
This advantage requires a more detailed explanation:
Any behavior of the electronic components used in the control device can only be guaranteed within a restricted technology-related operating range. As soon as this range is left, e.g. if impermissibly high voltages are present at any point of the system, any given configuration of the release signals is conceivable.
If the monitoring device exceeds a certain complexity it is economically sensible in practice to embody this device in a different technology from the output stages which generally involve power output stages, namely expediently in a low-voltage technology (such as the microcontroller for example).
If this monitoring device now assumes the task of overvoltage detection, since the precision required for this cannot generally be achieved in the power output stages to be deactivated, the case can arise that the permitted voltage range of the monitoring device is exceeded even if the output stage is still operating within its allowed range, so that a transition into the desired predetermined error case state can no longer be guaranteed.
If however the evaluation device possesses a greater dielectric strength than the microcontroller or those circuit parts of the control device which are necessary to provide the release signal, meaning that the evaluation device is for example integrated into an output stage device containing the output stage with relatively high dielectric strength, the overvoltage-related failure in the region of the microcontroller of the monitoring device or the release control device can still be reliably detected as long as the overvoltage does not cause a failure of the output stage device. The latter is however easy to guarantee by the corresponding dimensioning of the dielectric strength of the output stage which in practice in any event must be designed at least for the on-board network voltage of the motor vehicle plus a specific safety reserve.
The modulation of the release signal used in accordance with the invention should adversely affect the normal operation of the system as little as possible. In this regard it is advantageous for the period of the modulation to be prespecified such that this is selected to be at most as great as an error reaction time specified for the monitoring device, preferably less than this error reaction time. Periods of less than 100 ms are for example as a rule well suited to control devices for the internal combustion engine and/or the transmission of a motor vehicle. It is also of advantage for the pulse duty ratio of the modulation to be less than 10%, e.g. in the order of magnitude of 1%. If, as already mentioned above, the release signal from the release control device is inverted or interrupted in each case for the duration of one modulation pulse, the pulse duration should be selected to be comparatively small in relation to the period and the period itself should also be short enough for the application involved, taking into account all tolerances within predetermined error reaction times, to guarantee a reaction of the evaluation unit in the event of an error.
If the evaluation device has detected an absence of the modulation and thus an error, then for example a release signal which is in the first release signal state is output to the subsequent output stage or the subsequent output stages in order to disable an activation of the controlled components (at least for as long as the modulation is absent and/or at least for a predetermined period of time). Depending on the type of the component control it is however not basically excluded for the error state in which the output stage is to be placed simply to consist of releasing the activation. The decisive point is that in the event of an error which is detected by the absence of the modulation the output stage involved is put into a predetermined error case state. Even if with most output stages the obvious choice is to put the release signal permanently into a defined state for this purpose, it is possible as an alternative or in addition to explicitly influence the state of the output stage in another way, e.g. by any type of error case signal such as for example a reset signal which is provided for the output stage involved. Finally, on detection of an error case, this can also be notified to other circuit parts of the control device, especially to the microcontroller and/or the power supply unit with reset functions which, when the control device is started up, reset or start the individual device components in a defined manner.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in more detail below on the basis of an exemplary embodiment with reference to the enclosed drawings. The Figures show:
FIG. 1 is a schematic block diagram of an engine control device for controlling the operation of a fuel-injected engine of a motor vehicle, and
FIG. 2 is a diagram of the timing sequence of various signals occurring in the engine control device depicted in FIG. 1 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows major components of an engine control device identified as a unit by the number 10 for a direct-injection engine of a motor vehicle, comprising a microcontroller 12 for provision of a control signal S for control of the fuel-injection system in the operation of the internal combustion engine not shown, a release unit 14 for provision of a digital release signal b, by means of which through a first logical release signal “Low” (L) a disabling and through a second logical release signal “High” (H) an enabling of the activation of the fuel injection system is signaled, and an output stage 16 for activating and deactivating the component, to be controlled, in this case the fuel-injection system, based on the control signal S, taking into account a release signal d entered into this output stage 16 . with conventional engine control devices the release signal b output by the release unit 14 is entered directly into the output stage 16 or the signals b and d are identical. This is not the case with the control device 10 shown, as is described again below.
The output 16 initiates a fuel injection by outputting corresponding activation signals AS to the various fuel injectors (the signal lines shown on the right-hand edge of FIG. 1 symbolize the activation of four fuel injectors) only if the release signal d entered into the output stage 16 is in the H state. The injection timing and the injection amounts are in this case essentially defined by the control signal S output by the microcontroller 12 . To simplify the diagram the transmission of the control signal S is only symbolized here by a line. This connection can actually be embodied as a more complicated line arrangement depending on the output stage to be activated. Furthermore the diagram in FIG. 1 omits all parts of the circuit of the control device 10 which are not of any significance for understanding the invention and can be arranged in a conventional manner (e.g. power supply(ies), input signals the microcontroller for accepting various sensor signals which are needed as part of the vehicle component control or engine control).
One special feature of the control device 10 shown lies in its generation, transmission and use of a particular release signal and will be explained below with reference to an output stage 16 for a motor vehicle fuel injection system, which is merely to be taken as an example. Naturally the engine control device 10 in practice features further output stages for control of further motor vehicle components, for which the methods of an especially “safe” release signal described below can also be used.
A modulation device formed from a modulation stage 18 and a pulse generator 20 is connected directly downstream from the release unit 14 and takes care of periodic modulation of the release signal b provided by the release control device. If a number of release devices like the release device 14 shown are provided, in a monitoring device for example, a common pulse generator can advantageously be used for modulating the individual release signals.
The topmost (first) waveform shown in FIG. 2 represents the modulation pulse signal generated by the pulse generator 20 . This signal consists of a periodic sequence of rectangular modulation pulses with a period of Tpuls and a pulse duration of tpuls.
The second waveform shown in FIG. 2 presents a typical example of a release signal b output by the release unit 14 which changes at an end time t 1 from L to H and at an end time t 2 back to L again.
These signals a and b are entered into the modulation stage 18 so that a “modulated” release signal c is formed from them for which the waveform is also shown in FIG. 2 . It can be seen from this diagram that in the modulation stage 18 the H state, which signals the release of the activation of the fuel injection system, is periodically interrupted by a comparatively short modulation pulses during which the signal c to a certain extent signals the disabling of the injection system activation. In the example shown this periodic modulation merely takes place in signal sections in which the signal b is in the H state.
The output stage 16 is immediately preceded in the circuit by an evaluation stage 22 which is implemented in the same technology (here on the same chip) as the output stage 16 and along with this stage forms an output stage device 24 .
The release signal c input into the evaluation stage 22 is analyzed by the evaluation unit 22 with regard to the presence of the periodic modulation signal c, expressed in simple terms it is only forwarded to the output stage 16 as a release signal d if the modulation is detected in the input signal c. By contrast the evaluation stage 22 interprets an absence of the modulation as an error and then puts the output stage 16 into a previously defined error case state. In the exemplary embodiment shown this is done by permanently outputting the release signal d in the L state, and doing this regardless of the state of signal c. This means that in the example shown fuel injection is forcibly ended even independently of control signal S.
The waveform shown at the bottom of FIG. 2 represents the release signal d forwarded to the output stage 16 when the system is operating correctly. It can be seen from this waveform that the signal transition from L to H occurring at point in time t 1 (in signal c) is not forwarded immediately to the output stage (in signal d) but only after a fixed entry delay At 1 has elapsed. This is because the evaluation unit 22 in the example shown initially excludes the case in which this transition would have been caused by a “static” error in signal c (or in the transmission line provided for this signal). To this end the system waits for the period At 1 in order to detect the arrival of a modulation pulse. Only if this pulse is actually detected does the evaluation unit also let the signal d change over to the H state. At 1 in this case is slightly larger than the pulse period Tpuls and is of a fixed duration.
In a similar manner the transition in signal c from H to L occurring at point in time t 2 is not reflected directly in output signal d, but only after a certain delay (fall delay At 2 ). This is because the evaluation stage 22 in the previous example initially excludes the case in which this transition is merely caused by the arrival of a modulation pulse. Accordingly it waits for the period At 2 . Only if the signal c does not change back to H within this period does the evaluation stage 22 let the signal d change over to L. This fall delay At 2 is also fixed here and is slightly bigger than the pulse width tpuls.
The pulse period Tpuls, the pulse width tpuls and the “filter times” At 1 , At 2 are to be selected to suit the relevant system requirements. The pulse duty ratio (tpuls/Tpuls) should be as small as possible in most application cases e.g. smaller than 10%, especially smaller than 1%. In respect of short error reaction times of the evaluation stage 22 on the other hand a period Tpuls which is as short as possible is advantageous. In the example shown for fuel injection a Tpuls of the order of magnitude of around 10 ms is typically conceivable.
The evaluation stage 22 can for example cause an H state (enable) or L state (disable) of the signal d on the basis of specific criteria:
The signal c is in the H state and a first modulation pulse of full length (pulse width tpuls) is then detected. (->enable) The signal c is longer than the maximum pulse width to be expected in the L state. (->disable) the signal c is in the H state and 80 modulation pulse is absent within double the period Tpuls to be expected. (->disable) The signal c has an undefined level. This can be caused for example by an undervoltage in the range of the release signal generation. (->disable)
For most applications it is preferable to assign priority to the transition to L (disable) over the transition to H (enable).
In a conceivable further development there can be provision for the evaluation stage 22 , on detection of pulses in the signal, to also check the intervals between consecutive pulses to ensure that this tallies with the predetermined modulation period. This enables the correct modulation pulse sequence to be distinguished more precisely from of a pulse sequence generated by an error for example.
In a manner known per se the release unit 14 is contained in a monitoring device which communicates via a communications link 28 with the microcontroller 12 in order in particular to monitor the correct operation of the latter, and depending on the result of this monitoring, to set the release signal b accordingly for example.
In the example shown the evaluation stage 22 , as a result of its microelectronic integration into the region of the output stage device 24 , has a relatively high dielectric strength by comparison with the microcontroller 12 and/or the monitoring device 26 in technology terms (e.g. 36V). The evaluation stage 22 can thus advantageously also initiate error case measures, especially disabling or deactivating the output stage 16 , if parts of the circuit of the control device 10 which are involved in the provision of the release signal are adversely affected or destroyed by an overvoltage. Because of the modulation the fail-safe behavior of the system as a whole is therefore not only especially reliable but to an extent is autonomous, as far as a failure caused by an overvoltage of logic components such as the microcontroller is concerned. The additional logic in the output stage device 24 leads to an automatic permanent deactivation of the output stage 16 as soon as a static state of the deactivation path is detected which is transferring the signal c. In the solution described the dynamic required only needs to be generated in error-free system operations so that a restricted operating mode is made possible if only the deactivation path is incorrect, but not the control logic however. In the event of an error the output stage behaves under the critical operating conditions in the manner specified for it.
Advantageously the release or deactivation signal is safeguarded from the control of a signal driver in the release control device through to the reading out of this signal by an input comparator of a power output stage (i.e. completely from one IC to another IC for example). Only the function itself within the power output stage (in the event of an error) is to be ensured. The inventive solution covers any basic cause of an incorrect deactivation path. For implementation, additional, especially discrete additional components, are not necessarily required, which is favorable as regards cost and mean time between failures. The effectiveness of the security in operation can be guaranteed continuously if certain logic functions can remain usable provided only one deactivation line is defective. The inventive solution can be realized on the part of the monitoring device or of a monitoring module to be upwards-compatible to conventional output stages (if necessary with slight modification measures). A return from an impermissible into a permissible operating range of the monitoring device does not change anything in the effectiveness of the inventive deactivation as regards the deactivation path.
In summary, in the control of the operation of an internal combustion engine using a microcontroller with assigned output stages to control engine components, in addition to the actual control signal, a digital release signal is also supplied to an output stage, by means of which, depending on the signal state, a disabling or enabling of the output stage is signaled. This means that the output stage can be deactivated in the event of an error in the region of the microcontroller. By modulating the release signal and evaluating of the release signal fed through to the output stage ensures that an error in the region of the release signal generation and/or release signal transmission can be detected on the basis of the absence of the modulation and the output stage can be very reliably deactivated in the event of an error.
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When a microcontroller, having associated output stages which are used to control components, is used, a digital release signal, in addition to the control signal, is supplied to an output stage which signals the blocking or releasing of the output stage according to the state of the signal. In the event of malfunction in the region of the microcontroller, the output stage can be disconnected. Modulation of the release signal and evaluation of the release signal which is guided to the output stage enables a malfunction in the region of the production of the release signal and/or the transmission of the release signal to be recognized using the absence of the modulation. In the event of malfunction, the output stage can disconnected in a reliable manner.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a gripper weaving machine comprising a gripper which can be moved into and out of the shed and mounted to a rapier associated with guides which can be moved into and out of the shed through the warp sheet, and to guides for guiding a rapier.
2. Description of the Related Art
A gripper weaving machine of the above type is known from U.S. Pat. No. 5,183,084. Guide elements mounted in two rows are used to guide the rapier. The guide elements of the row facing the reed are mounted in a guide surface of the rapier. The guide elements of the row facing away from the reed are hook-shaped and enclose a side edge of the rapier. Such hook-shaped guide elements increase the danger of causing rupture of and/or damage to the warp threads when being moved into the shed and out again through the warp sheet.
SUMMARY OF THE INVENTION
The objective of the invention is to so design a gripper weaving machine and in particular, its guide elements such that the danger of the guide elements damaging the warp threads is substantially reduced.
This problem is solved by two guide surfaces on the underside of the rapier that are associated with the guide elements mounted in two rows wherein at least the segment of the guide elements passing through the warp sheet subtends at obtuse angles relative to the underside of the rapier at least in the vicinity of the rapier on the reed side.
As a result of the invention, the warp threads are stressed lower when the guide elements are moved into and out of the shed. This feature is most advantageous for warp threads having knots or nubs or other irregularities since the threads will slide along the guide elements without undue danger that they will snag on the guide elements.
Advantageously, and especially as regard to a maximally open shed, the guide elements will subtend at an obtuse angle on the side away from the shed relative to the warp sheet they have penetrated. As a result there is further reduction in the danger that the nubs or knots will snag, especially during the withdrawing motion from the shed as during closing which might damage the warps.
Preferably the upper edges of all guide elements will be in their positions below the surface of the underside of the rapier. The upper edges of all guide elements may then guide the underside of the rapier.
In another embodiment, a guide structure is located at least in the vicinity of the end of the rapier where the gripper is present and is guided by the guide elements. In a further design the underside of the rapier includes a guide structure at least in the vicinity of the end of the rapier where the gripper is located and is guided by the guide elements. In another design, a guidance part is mounted in the extension of the rapier in the vicinity of the gripper and is guided by the guide elements. This guidance part may include a guide structure that is guided by the guide elements. A guide structure affixed to the rapier and/or a guide structure of the rapier may be used in the extension of the guide structure of the guide. As a result, the gripper and/or the segment of the rapier in the region of the gripper may be guided transversely of the direction of motion of the rapier.
In the invention, guides to guide a rapier always includes at least two guide elements of which the upper edges are located in one plane and which are associated with two mutually parallel guide surfaces of the underside of the rapier.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the invention will be evident from in the description below of the illustrative embodiments shown in the drawings.
FIG. 1 is a schematic view of a gripper weaving machine with a plurality of guides of the invention in a position wherein the guides cooperate with the rapiers.
FIG. 2 is an enlarged cross-sectional view taken along line II—II of FIG. 1 .
FIG. 3 is an enlarged view of FIG. 2 in the region of a rapier aperture.
FIG. 4 is a further enlarged view of FIG. 3 .
FIG. 5 is a view of FIG. 3 during the insertion of the guides into a shed,
FIG. 6 is a detailed front view in the direction of the arrow F 6 in FIG. 3 .
FIG. 7 is a variation of the guide, having three guide elements, and corresponding to the front view of FIG. 6 .
FIG. 8 is another variant of a guide corresponding to the front view of FIG. 6 .
FIG. 9 is a partially sectional, elevational view, similar to FIG. 3 of an embodiment with the guides of FIG. 8 .
FIG. 10 is a partial elevational view in the direction of the arrow F 10 of FIG. 9 .
FIG. 11 is a partial elevational view similar to FIG. 3 of an embodiment with guides corresponding to FIG. 6 .
FIG. 12 is a top view of an embodiment similar to FIG. 10 .
FIG. 13 is a partially sectional elevational view of an embodiment configured with the guides of FIG. 6, and
FIGS. 14 through 16 are views similar to FIG. 10 of another embodiment variants.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The gripper weaving machine shown in FIGS. 1 through 6 comprises two rapiers 1 , 2 . A feed gripper 3 is mounted at the end of the rapier 1 and a receiving gripper 4 is mounted at the end of the rapier 2 . These grippers are inserted in the filling direction A into the shed and then are withdrawn. The rapier 1 driven a rapier drive device 5 moves the feed gripper 3 together with the filling (weft thread) to be inserted from the filling feed side to the center of the shed. There the receiving gripper 4 , moved in a corresponding manner by the rapier 2 driven a rapier drive device 6 , grips the filling and moves it to the opposite side of the shed. The drive devices 5 , 6 are respectively mounted in side frames 7 , 8 of the gripper weaving machine and include toothed wheels 9 , 10 driven by drive elements, wheels 9 , 10 , cooperating respectively with the rapiers 1 , 2 . The rapiers 1 , 2 are held in contact with wheels 9 , 10 by guide fittings 11 .
The gripper weaving machine also includes a batten 12 to which is affixed a reed 13 which rests in the side frames 7 and 8 . The batten 12 is reciprocally driven by batten devices 14 , 15 . The batten drive devices 14 , 15 and the repier devices 5 , 6 are preferably operated synchronously. The rapiers 1 , 2 are guided in the region of the side frames 7 , 8 by stationary guides 16 , 17 .
As schematically shown by FIG. 2, the gripper weaving machine further includes a shed forming device 18 which may be raised and lowered by a shed driving device (not shown in the drawings) and may be operated synchronously with the batten drive device 14 , 15 . FIG. 2 also shows two warp sheets 19 , 20 between which a shed 21 is formed and which receives a filling thread. These warp sheets 19 , 20 are formed by the shed-forming device 18 , of which only two are shown and which are raised and lowered according to a predetermined pattern.
The batten 12 includes a batten shaft 22 to which a contoured batten section 23 is affixed by screws 24 . The reed 13 is affixed by fasteners 25 to the contoured batten section 23 . Furthermore an intermediate contoured section 26 is affixed by screws 27 to the contoured batten section 23 , and a plurality of guides 28 according to the invention are affixed to this contoured intermediate section 26 .
The individual guides 28 are affixed by a screw 29 passing through a retention fitting 30 of the guides 28 and screwed into a thread 31 in the intermediate contoured section 26 . The thread 31 runs at an angle deviating from the perpendicular of the intermediate contoured section 26 . The retention fitting 30 is provided with a slanted surface 32 perpendicular to the thread 31 and supporting the head of the screw 29 .
By the reciprocating motion of the batten 12 , the plurality of the guides 28 are moved through the lower warp sheet 20 into and then out of the shed 21 . In this process, the guides 28 move in a plane passing through the lower warp sheet 20 which itself runs perpendicularly to the filling direction A.
FIG. 2 shows the position wherein the guides 28 have penetrated the shed 21 due to the pivoting motion of the batten 12 , the shed 21 at this position is at a maximally open position. In this position, the guides 28 guide the underside of the rapiers 1 , 2 . Their guide edges are in a substantially horizontal plane as shown in dashed lines in FIG. 2 and located underneath a beatup edge 33 of a fabric 34 against which the inserted fillings will be beaten by the reed as shown by the dashed lines at the left in FIG. 2 .
As shown on a larger scale in FIGS. 3 and 4, the guides 28 include two different guide elements 35 , 36 generally parallel but diverging over their full lengths, and mounted on the retention fitting 30 . The plurality of the guide elements 35 and the plurality of the guide elements 36 are each mounted in a row running in the longitudinal direction of the batten 12 and hence in the direction of motion of the rapiers 1 , 2 . The row of guide elements 35 terminate at ends guiding the underside of the rapiers 1 , 2 along a guide surface 37 facing the reed 13 . The row of guide elements 36 guides the underside of the rapiers 1 , 2 along an adjacent guide surface 38 facing away from the reed 13 . Accordingly, the row of guide elements 35 is located between the row of guide elements 36 and the reed 13 . As shown in FIG. 6, each guide element 35 is offset relative to a guide element 36 in the filling direction A at the retention fitting 30 .
As shown in FIG. 4, which shows in enlarged detail the position of the guides 28 having guide elements 35 and 36 in the position described in relation to FIG. 2, the bar-shaped or rod-shaped guide elements 35 and 36 project toward the underside of the rapiers 1 , 2 such that they subtend guide surface 37 at their ends in each case at obtuse angles B, B′ and C, C′ of about 120 to 150°. The essentially rectilinear segments of the guide elements 35 , 36 which penetrate through the warp sheet 20 into the shed 21 and which in the filling direction A are thinner than in a transverse direction of the same, and, at least in the vicinity of the rapiers 1 , 2 , subtend these angles B, B′ and C, C′, by their side edges facing the reed 13 . These side edges being located in a plane perpendicular to the filling direction A, and to the underside of the rapiers 1 , 2 . In the shown embodiment, the angles B and B, and C and C′ are approximately equal. The guide elements 35 , 36 slanting toward the reed 13 due to of their rounded upper edges 40 , 41 guide the guide surfaces 37 , 38 of the rapiers 1 , 2 , the latter being located in a substantially horizontal plane, as a result of which the rapiers 1 , 2 are supported substantially horizontally. As further shown by FIG. 4, the guide elements 35 , 36 in this preferred embodiment include a substantially straight segment over the part of the length penetrating the shed 21 .
As further shown by FIG. 4, the guide elements 35 , 36 are arrayed in such manner that, on the side away from the reed 13 , they subtend obtuse angles D, D′ and E, E′ relative to the threads of the warp sheet 20 between their side faces and the warp sheet 20 . As shown in FIG. 5, the side faces of the guide elements 35 , 36 also subtend obtuse angles F, F′ and G, G′ on the side away from the reed 13 relative to the warp sheet 20 , while the guide elements 35 , 36 move into or out of the opening and closing shed 21 respectively. As shown by FIGS. 4 and 5, the angles D, D′, the angles E, E′, the angles F, F′ and the angles G, G′ are substantially all of the same magnitude.
In the position of FIGS. 2, 3 and 4 , wherein the guides 28 cooperate with the rapier 1 , 2 , the upper edges 40 , 41 of the guide elements 35 , 36 will guide the underside either of the rapier 1 , 2 . It follows that the upper edges of the guide elements 35 , 36 in all other positions of these guide elements 35 , 36 will be located underneath the plane defined by the underside of the rapiers 1 , 2 .
The rapiers 1 , 2 are provided with apertures 39 (shown in FIGS. 4 and 10) cooperating with the teeth of the wheels 9 , 10 . As shown in FIG. 3, these apertures 39 are located substantially at the center of the rapiers 1 , 2 . The guide elements 35 , 36 are arrayed in such manner that they will not guide the rapiers 1 , 2 in the region of these apertures and accordingly, no wear by the guide elements 35 , 36 will take place in the region of said apertures.
As previously mentioned and as may be seen in FIGS. 4, 5 and 6 , the upper edges of the guide elements 35 , 36 are rounded to reduce the danger of damaging the rapiers 1 , 2 or the warps of the warp sheet 20 .
Because the underside of the rapiers 1 , 2 runs on the upper edges 40 , 41 of the guide elements 35 , 36 , the side edges of the guide elements 35 , 36 subtend with these upper edges 40 , 41 on the side facing the reed 13 at the same obtuse angles B, B′ and C, C′. The upper edges 40 , 41 of the guide elements run in a plane which is perpendicular to the filling direction A.
As shown by FIG. 7, two guide elements 35 and one guide element 36 are used for each retention fitting 30 . The guide element 36 is mounted between the two guide elements 35 .
As shown in FIGS. 8, 9 and 10 , the guide elements 35 and 36 are mounted in a common plane which is perpendicular to the filling direction A, as a result of which the guide elements 35 and 36 can be inserted between the warps of the warp sheet 20 into the shed 21 . The guide elements 35 and 36 are of such length that the retention fitting 30 and the site at which the two guide elements 35 , 36 are joined remain underneath the lower guide warp sheet 20 , whereby a warp that is to be gripped between the two guide elements 35 , 36 can always reach the warp sheet 20 during shed formation.
As shown in FIGS. 9 and 10, a guide structure 42 is mounted in the region of the ends of the rapiers 1 , 2 where the grippers 3 , 4 are located at each underside of these rapiers 1 , 2 and is guided between the guide elements 35 and 36 . This features precludes the rapiers 1 , 2 from moving in the transverse direction M and consequently they cannot deviate toward or away from the reed 13 . The guide structure 42 in this embodiment has a triangular cross-section.
A guide structure 43 which is present in the embodiment of FIGS. 11 and 12 in the region of the end of the rapiers 1 , 2 where the grippers 3 , 4 are located at the underside of these rapiers 1 , 2 , is guided between the guide elements 35 , 36 . In this embodiment the guide structure 43 is in each case integral with the rapiers 1 , 2 . Illustratively, the, guide structure 43 projects itself with a portion 43 A beyond the rapiers 1 , 2 . The guide structure 43 of this embodiment has a trapezoidal cross-section.
The guide structure 43 is located underneath the underside of the rapiers 1 , 2 and is thereby also underneath the plane subtended by the upper edges 40 , 41 of the guide elements 35 , 36 . Because in this embodiment the guide structure 43 extends by its front part 43 A beyond the end of the rapiers 1 , 2 , it is able to move warps that snag on one of the upper edges 41 , 42 of the guide elements 35 , 36 from these upper edges 40 , 41 before these upper edges are within reach of the underside of the rapiers 1 , 2 . FIG. 11 clearly shows that the guide structure 43 per se does not touch the upper edges 40 , 41 of the guide elements 35 , 36 .
A guidance part 44 is mounted in the extension of the rapiers 1 , 2 in the region of the grippers 3 , 4 of the embodiment shown in FIGS. 13 and 14. The underside of the guidance part 44 being flush with the underside of the rapiers 1 , 2 , as a result of which this part's underside is guided by the guide elements 35 , 36 . This guidance part 44 is provided with a downward-projecting guide structure 45 that is guided between the guide elements 35 , 36 . The guide structure 45 is integral with the guidance part 44 . In this embodiment the guide structure 45 is mounted at a distance from the front end of the guidance part 44 and as a result, the grippers 3 , 4 can be inserted into the shed 21 , in a manner similar to U.S. Pat. No. 5,183,084, readily before the guides 28 reach their end position as shown in FIG. 13 . The cross-section of the guide structure 45 is rectangular.
At the ends of the rapiers 1 , 2 , a guidance part 44 is provided with a guide structure 45 in the embodiment of FIG. 15 also corresponding to that of FIGS. 13 and 14. A guide structure 47 is present in the extension of the guide structure 45 at the rapiers 1 , 2 . This design includes a safety space in the longitudinal direction between the guide structure 45 of the guidance part 44 and the guide structure 47 of the rapiers 1 , 2 .
A guidance part 44 is present in the illustrative embodiment of FIG. 16 and comprises a guide structure 48 . Each rapier 1 , 2 is provided with one guide structure 49 in the extension of the guide structure 48 . The guide structures 49 directly adjoin the guide structure 48 of the guidance parts 44 . The guide structure 48 projects by a part 48 A beyond the front edge of the guidance parts 44 . This design therefore offers the same advantages already described as regard to the guide structure 43 with its front part 43 A as shown in FIGS. 11 and 12.
The cross-sections of the guide structures 42 , 43 , 45 , 47 , 48 , 49 may be triangular, rectangular or trapezoidal or other shape. These guide structures are designed in such a way that they can be guided between the guide elements 35 and 36 so that they preclude the rapiers 1 , 2 from moving to or from the reed 13 .
Practically all known grippers may be used as grippers 3 , 4 , for instance those shown in U.S. Pat. Nos. 4,708,174 or 4,860,800.
The invention is not restricted to the shown and described illustrative embodiments. In particular, modifications and/or combinations within the knowledge of persons skilled in the art may be undertaken without departing from the scope of the invention defined by the attached claims. In particular the invention may also may be applied to gripper weaving machines having only one gripper driven by one rapier and moving, in this case between the side of filling insertion and the opposite side of the machine.
The present invention is by no means restricted to the above-described preferred embodiments, but covers all variations that might be implemented by using equivalent functional elements or devices that would be apparent to a person skilled in the art, or modifications that fall within the spirit and scope of the appended claims.
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A gripper weaving machine with a plurality of guiding devices( 28 ) for guiding gripper carrying rapiers ( 1,2 ). The guiding devices ( 28 ) have two rows of guiding elements ( 35,36 ) with two guiding surfaces ( 37,38 ) that are associated with the bottom side of the rapiers ( 1,2 ). The guiding elements ( 35,36 ) are oriented relative to the bottom side of the rapiers ( 1,2 ) such that they form, at the side facing the reed ( 13 ), obtuse angles (B,B′,C,C′) with the bottom side of the rapiers ( 1,2 ).
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FIELD OF THE INVENTION
The present invention relates to a clothes dryer and, more particularly, to the placement of fuses in the clothes dryer cabinet to reduce the risk of fire occurring in the dryer cabinet or outside the cabinet due to shorting of the live wire lines in the dryer cabinet with one another, with the dryer cabinet, or with components inside the dryer cabinet.
BACKGROUND OF THE INVENTION
In domestic clothes dryers there has been a concern with respect to the build up of lint in the dryer or the ducting exiting the dryer, which build up of lint may result in the possibility of a fire in the dryer. As lint builds up in the dryer it creates a restriction on the airflow through the dryer. U.S. Pat. No. 6,671,977 issued to Beaumount discloses a safety system located outside of the dryer that measures the airflow in the exhaust vent and disconnects power to the household dryer female plug receptacle in the event that the airflow drops below a predetermined value.
U.S. Pat. No. 6,655,047 issued to Miller, II discloses a fire arrester for use with a clothes dryer that has a fire detector in a dryer vent externally of the dryer that detects fires starting in the dryer and disconnects electricity to the dryer while at the same time releasing an extinguishing agent into the dryer to suppress a fire. Neither of these two U.S. patents teaches the use of fuses in the dryer to disconnect power to the dryer.
U.S. Pat. No. 5,315,765 issued to Holst discloses a circuitry for a high efficiency microwave dryer wherein the live wire lines each has a fuse connected in circuit therewith. A third fuse is connected in circuit with a DC power supply. This patent teaches these fuses being current limiting fuses. There is no teaching of the physical location of these fuses in the dryer cabinet. U.S. Pat. No. 4,663,861 also discloses a fuse in dryer circuitry for disconnecting power to the dryer control circuit. There is no teaching in this patent of the physical location of the fuses in the dryer cabinet. Further, neither of these two US patents discloses the purpose of these fuses other than to be current limiting fuses.
As a result of testing done on domestic clothes dryers, it has been determined that electrical arcing between wires in the cabinet of the dryer can cause fire on the wire coatings of the wire, can spread fire to other areas in the dryer or ignite a cheese cloth draped over the dryer cabinet where the cheese cloth represents clothing left on top of the dryer by a user. Testing has shown that this arcing has caused cheese cloth, representing dust or lint trapped in the dryer or other items placed on or beside the dryer, to catch fire. The mere use of fuses in the wiring circuitry of the power lines may not be sufficient to reduce the risk of fire due to arcing between live wires. Further, the use of power disconnect devices other than fuses may be too slow or not sufficiently sensitive to disconnect power from the dryer when initial arcing occurs between wires. Also, power disconnect devices may not protect against arcing due to fires being random and the power disconnect device not reacting to potential causes of the fire resulting in a fire being produced in the dryer cabinet or on the outside of the cabinet. Consequently there is a need in domestic clothes dryers to provide for power disconnection to the dryer electrical load in the cabinet such that the wiring in the cabinet is a reduced safety hazard.
BRIEF DESCRIPTION OF THE INVENTION
The present invention relates to a clothes dryer and, more particularly, to the placement of fuses in the clothes dryer cabinet to reduce the risk of fire occurring in the dryer cabinet, or outside the dryer cabinet, due to shorting of the live wire lines themselves in the dryer cabinet, with the cabinet, or components inside the cabinet. The placement of the fuses closely adjacent to the opening where the wiring enters the clothes dryers allows the fuses to be wired into the circuit in series with each of the live power lines and thereby limit or minimize the length or amount of wiring in the dryer cabinet that is not protected by the fuse. Hence the risk is diminished of a fire starting due to arcing between wires, between the wires and components in the cabinet, or between the wires and the cabinet as a result of mishandling of the wiring, malmanufacturing of the wires, or due to fire that melts or burns wire insulation and causes electrical shorting that may ignite clothing that drapes the dryer cabinet.
It is important to disconnect power to the clothes dryer circuitry in the event of a fire in the base of the cabinet or in the drum of the dryer thus preventing any further shorting of the wires so as to diminishes the chances of a fire spreading outside of the dryer cabinet. Hence it is advantageous to have as much wire protected as possible in the cabinet by the fuses as this reduces the risk of any fire initiating in the dryer cabinet as a result of the wiring in the cabinet arcing.
In accordance with one embodiment of the present invention, there is provided a clothes dryer having an electrical load, comprising a cabinet having a wall. A power cord is electrically connected to the wall of the cabinet. The power cord has a neutral wire line and at least one entry live wire line. The neutral line is connected in electrical circuit with the electrical load. The wall has a wiring entry opening through which the neutral wire line and the at least one entry live wire line pass into, and extend within, the cabinet. The electrical load is further connected in electrical circuit with at least one load live wire line extending within the cabinet. A fuse for each entry live wire line is connected in electrical circuit between a corresponding entry live wire line and a corresponding load live wire line for disconnecting power to the load live wire line and the electrical load. The fuse is located inside the cabinet closely adjacent to the wiring entry opening so as to limit length of the at least one entry live wire line within the cabinet.
In accordance with another embodiment of the invention there is provided a clothes dryer having an electrical load, comprising a cabinet having a wall. A power cord is electrically connected to a terminal block mounted on the wall outside of the cabinet. The power cord has a cord neutral wire line and two cord live wire lines respectively connected at the terminal block to a dryer neutral wire line and corresponding ones of two dryer entry live wire lines. The electrical load is connected in electrical circuit with the dryer neutral wire line and two load live wire lines extending only within the cabinet. The wall has a wiring entry opening through which the dryer neutral wire line and the two dryer entry live wire lines pass into the cabinet from the block. Two fuses are each connected in electrical circuit between a corresponding one of the dryer entry live wire lines and a corresponding one of the load live wire lines for disconnecting power to the corresponding one load live wire line and the electrical load. The fuses are located inside the cabinet closely adjacent to the wiring entry opening so as to limit length of the dryer entry live wire lines within the cabinet.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more thorough understanding of the nature and objects of the present invention reference may be had, by way of example, to the accompanying diagrammatic drawings in which:
FIG. 1 is a perspective view of an exemplary clothes dryer that may benefit from the present invention;
FIG. 2 is a side sectional view of an exemplary clothes dryer that may benefit from the present invention;
FIG. 3 is an interior perspective of the exemplary clothes dryer showing the rear wall of the clothes dryer cabinet with the rotating drum removed;
FIG. 4 is a partial exterior view of the rear wall showing the connection of the power cord to an exemplary terminal block for an exemplary electric clothes dryer;
FIG. 5 is an electrical schematic diagram for an exemplary clothes dryer heated by one or more electrical heating elements; and,
FIG. 6 is an electrical schematic diagram for and exemplary clothes dryer heated by a gas heater.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a clothes dryer and in particular to the placement of fuses in the clothes dryer cabinet to reduce the risk of fire occurring in the dryer cabinet due to shorting of the live wire lines in the dryer cabinet.
Referring to FIGS. 1 to 3 , an exemplary clothes dryer 10 that may benefit from the present invention is shown. The clothes dryer 10 includes a cabinet or a main housing 12 having a front wall 14 , a rear wall 16 , a pair of side walls 18 and 20 spaced apart from each other by the front and rear walls, a floor 21 and a top cover 24 .
Within the housing 12 is a drum or container 26 mounted for rotation around a substantially horizontal axis. A motor 44 rotates the drum 26 about the horizontal axis through, for example, a pulley 40 and a belt 42 . The drum 26 is generally cylindrical in shape, has an outer cylindrical wall 28 , and has an open end 27 that typically comprises a metal ring 29 attached by welding to the drum 26 for reducing the diameter of the opening of the drum 26 to match a front bulkhead wall or front bearing 30 . The bearing 30 further defines an opening 32 into the drum 26 . Clothing articles and other fabrics are loaded into the drum 26 through the opening 32 . A plurality of tumbling ribs (not shown) are provided within the drum 26 to lift the articles and then allow them to tumble back to the bottom of the drum as the drum rotates.
The drum 26 includes a drum rear wall 34 rotatably supported within the main housing 12 by bearing 35 . The drum rear wall 34 includes a plurality of holes (not shown) that receive hot air that has been heated by a heater comprising electrical heating elements 64 located in heater housing 22 . The heater housing 22 receives ambient air passing through an inlet or louvres 36 and into the heater housing around circular flange 66 of the heater housing 22 .
Although the exemplary clothes dryer 10 shown in FIG. 1 is an electric dryer having electrical heating elements 64 that warm the ambient air, it should be understood that the dryer may be a gas dryer having a gas burner for heating ambient air entering the dryer. The gas burner may be located below the drum 26 and have ducting extending from the gas burner up to the drum rear wall 34 .
Air heated by the heater is drawn into and from the drum 26 by a blower fan 48 which is also driven by a second motor 49 in the embodiment shown. In an alternative embodiment, motor 44 may be used to drive blower fan 48 . Air is drawn by the blower fan 48 from the heater housing 22 , into, through and out of the drum 26 , through a grill 45 and screen filter 46 . Grill 45 keeps clothing articles tumbling in the drum 26 from contacting the filter 46 and touching the lint trapped by the filter 46 within the trap duct 50 . As the air passes through the screen filter 46 , it flows through lower duct portion 51 and is blown by blower wheel 48 attached to motor 49 out of the clothes dryer 10 through an exhaust duct 52 . In this embodiment, the drum 26 is in air flow communication with the trap duct 50 whose lower duct portion 51 has an outlet that is in air flow communication with the blower wheel 48 and the exhaust duct 52 . The exhaust duct 52 passes through the rear panel 16 and is usually connected to suitable venting (not shown) that vents the air outdoors.
After the clothing articles have been dried, they may be removed from the drum 26 via the opening 32 . Opening 32 is shown closed by a window or port-hole like door 60 . Door 60 has a handle 62 for pivotally opening the door about hinge 64 .
The dryer 10 is shown to have a control panel 54 with touch and or dial controls 56 that permit the user to control operation of dryer 10 .
Referring to FIGS. 3 , 4 and 5 the wiring circuitry for clothes dryer 10 is shown. Power is supplied to the dryer in FIG. 4 through a power cord 68 , the power cord 68 has two live power wire lines 70 and 72 , a neutral wire line 74 and a ground wire 76 . Ground wire 76 is shown connected by screw 78 to the rear wall 16 of the clothes dryer. The wire lines 70 , 72 , 74 and 76 of the power cord 68 are rated for 120/240 volts and 30 amps. The power cord 68 is connected to the dryer rear wall 16 through a strain relief bracket 80 . The live wire lines 70 and 72 as well as the neutral wire line 74 are connected by screws 82 to separate connection terminals in terminal block 84 of the terminal block assembly 86 . A cover 88 is fastened by screw 89 to the rear wall 16 to cover the terminal block assembly 86 . The terminal block 84 is shown mounted to the outside of the rear wall 16 .
Referring to FIGS. 3 and 4 , a dryer neutral wire line 90 and two cabinet live wire lines 92 and 94 pass through a wiring entry opening 100 located in the rear panel 16 of the dryer 10 . Wires 90 , 92 and 94 are shown in FIG. 4 entering the dryer cabinet 12 through the opening 100 and are shown in FIG. 3 emerging from the opening 100 into the interior of the dryer cabinet 12 . The dryer entry live wires 92 and 94 are respectively connected through fuses 104 and 106 with respective load live wire lines 96 and 98 . Load live wire lines 96 and 98 together with neutral line 90 are connected in wiring harness 108 to provide power to various loads within the clothes dryer cabinet including for example motor 44 and heating elements 64 of heater housing 22 . It should be understood that the wiring harness 108 will also provide power to motor 42 and to a power supply (not shown) for the electronic components for the clothes dryer 10 .
Referring to FIG. 5 , the distribution of the power to the loads 44 , 49 , 64 and 110 in the dryer drum is shown. Power line L 1 has fuse 104 between dryer load live wire line 98 and dryer entry wire line 92 to provide power to the drum motor 44 and the blower motor 49 . Power from the second power line L 2 is by dryer entry power live wire line 94 , fuse 106 , and load power live wire line 96 to the electrical heating element 64 and the electronic power supply 110 . In the event of shorting or arcing caused by the wire lines 96 , 98 ; fuses 106 , 104 open or blow disconnecting the load wires from the power.
As can be seen in FIG. 3 , the placement of the fuses 104 and 106 on the fuse terminal block or supporting block 102 is closely adjacent to the entry opening 100 for the wiring. This limits the length of the wires 92 and 94 to extend a considerably short distance within the dryer cabinet. As a result, this is the only portion of the live wires in the cabinet that may be considered to be unprotected by the fuses. Accordingly the other live wiring associated with live load wire lines 96 and 98 are protected by the fuses 104 and 106 blowing to disconnect power to the live load wiring 96 and/or 98 in the event of any arcing or deterioration in the wiring thereby reducing the risk of a potential fire in the dryer cabinet or outside the dryer cabinet.
The wiring circuitry shown in FIGS. 3 and 4 is for two power lines to the electric dryer and the fuses are each 30 amp fuses referred to as FLM fuses. A fuse suitable for the embodiment of the present invention of FIGS. 3 and 4 is a 30 amp fuse manufactured by LITTEL FUSE of Illinois, USA under part number L7L12F.
It should be understood that for a gas dryer, the amount of power to the dryer is reduced since the heating is achieved by combustion of natural gas or propane gas, and not by electrical heating elements. As a result, typically wiring for this arrangement comprises one power line and one neutral line entering into the dryer drum and rated at 120V and 15 Amps. A power cord connected to the dryer includes a power line, a neutral line and a grounding wire line. The grounding wire is grounded to the chassis or cabinet 12 of the clothes dryer 10 . A block is used similar to that shown in FIG. 4 , or alternatively, the power cord is connected directly through a strain relief bracket to the dryer so that the live wire line and the neutral wire line of the power cord pass directly through a wire entry opening into the clothes dryer cabinet. The fuse is located closely adjacent to the entry opening so as to minimize the length of unprotected live wire line of the power cord within the dryer cabinet. A schematic representation of the wiring diagram or such a system is shown in FIG. 6 wherein the entry live wire line 116 and the neutral wire line 114 are provided for supplying power to the blower motor 49 , the drum motor 44 , the gas burner 120 , and the electronic power supply 110 . Fuse 118 is located in the circuit to disconnect power to the load live wire line 130 and the load 49 , 44 , 120 , and 110 .
The fuse 118 is located closely adjacent to the entry opening through which the power lines entered into the dryer cabinet similar to the arrangement shown in FIG. 3 , save for one fuse instead of two, so as to minimize the length of the live wire line within the cabinet that is not protected by the fuse 118 . In this embodiment for a gas dryer, one 15 amp fuse may be used such as a CCMR fuse. Such a fuse is available by LITTEL FUSE under part number L8B22F.
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 modifications within the scope of the present invention as disclosed herein.
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A clothes dryer cabinet has a rear wall with a wire entry opening through which wiring enters into the dryer cabinet. A fuse supporting block is mounted closely adjacent to the wire entry opening and supports fuses which are connected directly to the wiring entering through the wire opening so as to limit or minimize the length of wiring contained in the dryer drum that is not protected by the fuses. This safety feature reduces the chance of fires occurring in the dryer as a result of arcing between wires due to mishandling of the wires, malmanufacturing of the wires or a fire occurring in the dryer.
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CLAIM OF PRIORITY
[0001] This application claims priority under 35 USC §119(e) to U.S. Patent Application Ser. No. 62/386,681 filed on Dec. 8, 2015, the entire contents of which are hereby incorporated by reference.
GOVERNMENT RIGHTS
[0002] This invention was made with government support under Contract Number D14AP00040 awarded by the Defense Advanced Research Projects Agency. The government has certain rights in the invention.
BACKGROUND
[0003] It is useful to integrate electronic structures onto flexible substrates for flexible electronics. However, direct integration of microelectronics with swollen hydrogel substrates is challenging with commonly available microfabrication techniques such as photolithography and transfer printing. Hydrated networks prohibit vacuum-based thin-film deposition techniques directly on hydrogel substrates. High swelling ratios and hydrated surface environments of the hydrogel substrates also attenuate van der Waals interactions, which are used for transfer printing of prefabricated microelectronics. Furthermore, most elastomeric substrates used in flexible electronics have Young's moduli ranging from 0.2-2 MPa, orders of magnitude larger than the modulus of many excitable organs including the heart and brain. The mechanical mismatch at the biotic-abiotic interface may damage local cell populations due to acute insults and micro-motion artifacts. The resulting tissue responses prohibit stable chronic device operation and tissue integration.
SUMMARY
[0004] This document describes application-specific target hydrogel substrates for electronic structures. Additionally, this document describes processes for transfer printing of electronic structures to swollen hydrogels. The adhesion-promoting hydrogels and transfer printing processes are made possible through the design and synthesis of the adhesion-promoting hydrogels as target substrates. This document describes fabrication techniques that advance ultracompliant electronics by melding microfabricated structures with swollen hydrogel substrates.
[0005] In some implementations, the conformable substrate includes a hydrogel having adhesion-promoting features, such as moieties comprising one or more catechol groups. In some implementations, the catechol groups are presented by a monomer, such as domaine methacrylate. In some implementations, other functionalities achieve adhesion such as dopamine acrylates, polydopamine films or networks, and so forth. The conformable substrate further comprises an array of microelectrodes bonded to the hydrogel by the adhesion-promoting features or moieties, such as the one or more catechol groups.
[0006] The catechol group is bonded to the microelectrodes using one or more of aromatic groups, hydrogen bonds, and coordination bonds. The hydrogel includes one or more of poly 2-hydroxyethyl methacrylate and polyethyleneglycol. The hydrogel includes a dopamine methacrylamide monomer.
[0007] In some implementations, the hydrogel includes a precursor solution photocrosslinked into a film. The precursor solution includes a P(HEMA-co-DMA) precursor solution having approximately 86.8 mol/mol % HEMA and 10.7 mol/mol % DMA. The precursor solution includes a P(HEMA) precursor solution having approximately 97.5 mol/mol % HEMA. The film includes a thickness in a range of 100 nanometers to 10 millimeters. The microelectrodes include a gold layer having a thickness of approximately 30 nanometers. The microelectrodes have an approximate width of 2 mm, a length of 200 μm, and are spaced from each other by a spacing of 100 μm.
[0008] In some implementations, at least 98% of the microelectrodes comprise a crack-free morphology. In some implementations, the hydrogel has a swelling ratio of greater than 4.85. In some implementations, the resistance of at least one microelectrode of the array of microelectrodes is between 10 and 15 ohms.
[0009] In some implementations, at least one microelectrode of the array of microelectrodes includes a strain-relief geometrical design that reduces strain effects from swelling of the hydrogel. The strain-relief geometrical design includes a serpentine design.
[0010] In some implementations, the hydrogel forms a contact lens. In some implementations, the hydrogel forms a conformal sensor for measuring EEG. In some implementations, the hydrogel forms an electrochemical sensor. In some implementations, the hydrogel forms a laminated sensor for monitoring cardiac activity. In some implementations, the hydrogel forms a sensor/stimulation combination for use with stimulating/monitoring cells cultured on hydrogel-based substrates.
[0011] In some implementations, the microelectrodes comprise one or more of metal conductors, ceramics, polymers, semiconductors, or insulators.
[0012] In some implementations a process for transfer printing microelectronics into a hydrogel substrate includes coating a donor substrate with a film of polyacrylic acid, crosslinking the film of polyacrylic acid in a solution comprising divalent ions, patterning a microelectrode array onto the crosslinked film of polyacrylic acid, laminating an adhesive hydrogel substrate onto the donor substrate coated by the crosslinked film of polyacrylic acid comprising the patterned microelectrode array, and separating the crosslinked film of polyacrylic acid from the donor substrate in a monovalent solution.
[0013] In some implementations, the patterning includes one or more of photolithography, electrodeposition, or nanoimprinting. In some implementations, the microelectrode array includes gold and the patterning includes thermal evaporation through shadow masks. In some implementations, 99.5% or more of microelectrodes of the microelectrode array are transferred to the hydrogel during the laminating and the separating.
[0014] In some implementations, the actions include forming the adhesive hydrogel substrate from a P(HEMA) precursor solution having approximately 97.5 mol/mol % HEMA. In some implementations, the actions include forming the adhesive hydrogel substrate from a P(HEMA-co-DMA) precursor having 86.8 mol/mol % HEMA and 10.7 mol/mol % DMA. In some implementations, laminating includes compressing the donor substrate into the adhesive hydrogel substrate without external heat or pressure and while submerged in water.
[0015] In some implementations, a process for transfer printing microelectronics into a hydrogel substrate includes coating a silicon substrate with a film of polyacrylic acid, wherein the film of polyacrylic acid is water-soluble; crosslinking the film of polyacrylic acid in a CaCl 2 solution comprising Ca 2+ ions; patterning an array of gold microelectrodes onto the crosslinked film of polyacrylic acid by thermal evaporation, wherein the microelectrodes have a width of 2 mm, a length of 200 μm, and spacing of 100 μm, and wherein a thickness of the microelectrodes is 30 nm; laminating, onto the silicon substrate, a P(HEMA-co-DMA) hydrogel substrate, the silicon substrate coated by the crosslinked film of polyacrylic acid comprising the patterned array; separating the crosslinked film of polyacrylic acid from the silicon substrate in a NaCl solution.
[0016] The application-specific target hydrogel substrates and transfer printing processes described herein provide several advantages. Polymeric substrates are an important component in flexible electronics because they can overcome many limitations associated with inorganic substrates that may be rigid, brittle, and planar. Devices fabricated on polymeric substrates can also be light weight, stretchable, or biodegradable. These systems are suitable for applications including environmentally friendly sensors, wearable medical devices, and temporary biomedical implants. For example, contact lenses can be impregnated with electronics to improve visual acuity or measure glucose levels in real time.
[0017] Dissolvable and elastomeric substrates allow conformal coating of sensor arrays with curvilinear organs such as the skin, eye, heart, and brain. Devices that interface with excitable cells will benefit from substrate materials that are highly compliant to promote conformal contact and reduce the risk of damaging delicate tissue. Hydrogel-based materials can improve the sensing and stimulation of excitable tissue by promoting conformal integration of electronic devices and bridging the abiotic-biotic interface.
[0018] Multi-electrode arrays fabricated on ultrathin poly(ethylene terephthalate) substrates use polyrotoxane hydrogel films to improve tissue-device integration while monitoring cardiac function in vivo. Hydrogels can serve as templates for in-situ assembly of metallic nanoparticles through metal ion reduction or conducting polymers via oxidative polymerization.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1A shows an example chemical structure of P(HEMA-co-DMA).
[0020] FIG. 1B is a graph showing FT-IR spectra of the DMA monomer, dehydrated P(HEMA) and P(HEMA-co-DMA) hydrogel networks.
[0021] FIG. 1C is a graph showing storage G′ and loss G″ moduli of both P(HEMA-co-DMA) and P(HEMA) hydrogel substrates.
[0022] FIG. 2A is a graph showing a representative force-distance curve.
[0023] FIGS. 2B-2C are graphs showing values for extracted tensile work per area for hydrogels.
[0024] FIG. 3 shows an example process for transfer printing electronic structures onto a hydrogel.
[0025] FIG. 4 are images showing optical micrographs of Au microelectrode arrays.
[0026] FIG. 5 is a graph showing values for extracted resistance of Au microelectrodes.
[0027] FIG. 6 is a diagram showing a comparison of substrates for electronic structures.
[0028] FIG. 7 is a chart showing a 1 H NMR spectrum of a DMA monomer.
[0029] FIG. 8 is a graph showing representative force-distance curves of both P(HEMA-co-DMA) and P(HEMA) hydrogels.
[0030] FIGS. 9A-9C are representative macroscopic images showing transfer printing of AU microelectrode arrays from donor substrates onto hydrogel target substrates.
[0031] FIG. 10 is an optical micrograph showing the formation of microcracks in a microelectrode.
[0032] FIG. 11 shows composition-dependent transfer printing of various metals with P(HEMA-co-DMA) hydrogels of varying DMA concentrations.
[0033] FIG. 12 is a graph showing transfer printing results.
DETAILED DESCRIPTION
[0034] The present invention includes an application-specific target hydrogel substrate for transfer printing of electronic microstructures. This approach utilizes hydrogels with adhesion-promoting moieties that permit direct assembly of functional microstructures on swollen target hydrogel substrates via transfer printing. This technique melds thin film patterning and deposition techniques with adhesive highly compliant swollen hydrogel substrates.
[0035] Adhesion in hydrated environments is a challenging problem that has been solved in part by recent discoveries of adhesion-promoting catechol-bearing materials. Catechols bond to inorganic/organic materials in hydrated environments through polarizable aromatic groups, hydrogen bonds, and coordination bonds. Hydrogels synthesized from non-toxic poly(2-hydroxyethyl methacrylate) (P(HEMA)) and polyethyleneglycol precursors are materials that are employed in biomedical devices used in human trials for many applications including controlled release matrices, soft contact lenses, and artificial corneas. Catechol-bearing HEMA-based hydrogels are suitable target substrates for transfer printing of electronic structures.
[0036] Turning to FIG. 1A , a chemical structure of P(HEMA-co-DMA) is shown. Dopamine methacrylate (DMA) monomers are copolymerized with HEMA hydrogels and poly(ethyl glycol) dimethacrylate crosslinker to form P(HEMA-co-DMA) hydrogels. Other monomers besides dopamine methacrylate are suitable for presenting the catechol that functions as the adhesive component. In some implementations, the catechol bearing monomer can include dopamine acrylates, polydopamine films, polydomaine networks, and so forth.
[0037] DMA incorporation was characterized using Fourier Transform Infrared Spectroscopy (FT-IR) (e.g., as seen in FIG. 1B ). FT-IR spectra of the DMA monomer, dehydrated P(HEMA) and P(HEMA-co-DMA) hydrogel networks indicates the incorporation of DMA with two characteristic peaks highlighted at 1602 and 1523 cm −1 . The inset (i) shows a full spectrum of FT-IR from 4000-400 cm −1 . Inset (ii) shows a deconvoluted spectra (dash lines) of the original spectrum (solid line) from 1600 to 1650 cm −1 of P(HEMA-co-DMA)). DMA monomers exhibit strong peaks at 1523 and 1653 cm −1 , which are assigned to N—H bending in amides and C═C bonds in pendant methacrylates, respectively. The latter peak is abolished after P(HEMA-co-DMA) hydrogel formation through crosslinking via photopolymerization. Peak deconvolution of features from 1600 to 1650 cm −1 of P(HEMA-co-DMA) indicates that C—C stretches at 1602 cm −1 from aromatic rings in DMA are preserved in P(HEMA-co-DMA) hydrogels. The new peak at 1633 cm −1 in P(HEMA-co-DMA) is assigned to C═O bonds associated with possible catechol oxidation into quinone during free radical photopolymerization.
[0038] Turning to FIG. 1C , the storage G′ and loss G″ moduli of both P(HEMA-co-DMA) and P(HEMA) hydrogel substrates are shown with a frequency swept between 0.1 and 100 rad s −1 under constant 2% strain. P(HEMA-co-DMA) hydrogels with a 10:1.23 ratio of HEMA to DMA exhibit a storage modulus G′ HEMA-co-DMA =8.2±1.2 kPa (ω=0.1 rad s −1 , which is comparable to the storage modulus of P(HEMA) at the same frequency G′HEMA=7.7±0.7 kPa.
[0039] Both G′ HEMA-co-DMA and G′ HEMA are largely frequency independent. The value of G′ HEMA-co-DMA increases to 24.4±4.6 kPa at w=100 rad s −1 while G′ HEMA increases to 16.5±2.8 kPa. These values match the range of storage moduli of excitable tissues such as those located in the heart and brain.
[0040] Values for G′ HEMA-co-DMA are also slightly larger than G′ HEMA at all frequencies. Both HEMA and DMA monomers can participate in intra- and intermolecular H-bonding via pendant hydroxyl groups and esters/amides, respectively. The observation that G′ HEMA-co-DMA >G′ HEMA can be attributed to DMA groups that both reduce chain rotation and form physical crosslinks via π-π stacking. The loss modulus G″ HEMA-co-DMA for P(HEMA-co-DMA) hydrogels exhibits a stronger frequency dependence compared to G″ HEMA such that G″ HEMA-co-DMA >2G″ HEMA at the frequency regime of ω>5 rad s −1 . This observation could be attributed to DMA groups in swollen P(HEMA-co-DMA) hydrogels that form transient physical crosslinks through π-π stacking that can be ruptured at high frequencies. The viscoelastic behavior of P(HEMA-co-DMA) hydrogels described herein is consistent with previous reports of catechol-bearing hydrogels. Taken together, the mechanical properties of P(HEMA) hydrogels are largely preserved despite incorporating DMA.
[0041] The adhesion between Au films and either catechol-bearing P(HEMA-co-DMA) or control P(HEMA) hydrogels was measured via uniaxial indentation with both Au and hydrogel surfaces fully submerged in water. Au is an ideal material for integration with hydrogel substrates for prospective biomedical applications because it is electronically conductive and corrosion resistant. In some implementations, a mix of other conductive metals, ceramics, polymers, semiconductors, and insulators is used for the electronic structures. Au is also an important test case for adhesive hydrogels because it is chemically inert and does not form covalent bonds with catechol-bearing moieties. Adhesion experiments were performed by coating a planar rigid indenter with a thin layer of Au and placing it in contact with hydrogels at a constant maximum preload for a fixed amount of time. Force-distance curves were then recorded as the indenter is retracted from the hydrogel.
[0042] Turning to FIGS. 2A-2C , the shaded area of the force-distance curve represents the tensile work needed to overcome the interfacial adhesion and delaminate the Au-coated indenter completely from the hydrogel. FIG. 2A shows a representative force-distance curve recorded when retracting the Au-coated indenter from the P(HEMA-co-DMA) surface at a constant speed of 0.1 mm s −1 after 5 minutes' contact at a constant preload of 50 mN. The shaded area indicates the tensile work needed to fully delaminate the indenter from the hydrogel surface. FIG. 2B shows values for extracted tensile work per area W gel-Au with constant preload of 50 mN and varied retracting velocity from 0.01-1 mm s −1 . FIG. 2C shows values for extracted W gel-Au with constant retracting velocity 1 mm s −1 and varied preloads from 10-50 mN that indicate the marginal surface adhesion increase in P(HEMA-co-DMA) versus P(HEMA) hydrogels.
[0043] The speed of delamination influences the interfacial adhesion and is an important parameter in engineering transfer printing processes. Representative force-distance curves and the extracted tensile work per unit area W gel-Au are shown for each hydrogel substrate composition as a function of retraction speed (See FIGS. 8 and 2B ). Both P(HEMA) and P(HEMA-co-DMA) hydrogels exhibit rate-dependent adhesion where W gel-Au is positively correlated with retraction speed. This observed trend is attributed to the viscoelastic nature of the hydrogels. Catechol-bearing P(HEMA-co-DMA) hydrogels with the 10:1.23 ratio of HEMA to DMA significantly increase the value of W gel-Au compared to P(HEMA) (W HEMA-co-DMA-Au ˜3 W HEMA-Au ) for retraction speeds ranging from 10 μm s −1 to 1 mm s −1 . Comparable increases in surface adhesion have been reported in other catechol-bearing hydrogel networks.
[0044] The improved adhesion described above could be attributed to several types of bonds between the hydrogel substrates and Au films. Although not wishing to be bound by theory, one possible mechanism for increased adhesion of P(HEMA-co-DMA) hydrogels to Au films is hydrogen bond formation between catechols and adsorbed water on Au surfaces. P(HEMA) can form similar bonds via pendent hydroxyl groups from HEMA monomers. Highly polarizable aromatic groups in DMA may bond to Au films through charge transfer or π-π stacking. The material dampening as measured by tan (δ HEMA-co-DMA ) is >10% higher compared to tan (δ HEMA ) at an angular frequency ω=0.2 rad s −1 , as shown in FIG. 1C . This value roughly corresponds to the maximum retraction velocity v=1 mm s −1 . These data suggest that P(HEMA-co-DMA) dissipates more energy through viscous responses compared to P(HEMA) hydrogel substrates and therefore requires relatively more tensile work for delamination. The observed relationship of W HEMA-co-DMA-Au ˜3 W HEMA-Au could be due to increased interfacial bonding and viscous dissipation in catechol-bearing hydrogels. The values of W HEMA-co-DMA-Au and W HEMA-Au were also measured as a function of preload force, as shown in FIG. 2C . The measured value of W HEMA-co-DMA-Au is larger than W HEMA-Au for all preload conditions.
[0045] As seen in FIG. 3 , Au microstructures are transferred to adhesive P(HEMA-co-DMA) hydrogel substrates using a modified transfer printing process. Donor substrates for transfer printing are prepared by (a-i) spin-coating a sacrificial layer of water-soluble PAA and (a-ii) crosslinking in CaCl solution prior to (a-iii) fabricating Au microelectrodes on PAA-Ca2 surfaces. An adhesive swollen P(HEMA-co-DMA) target substrate is conformably laminated (a-iv) on the donor substrate surface for 5 minutes and (a-v) removed from the donor substrate in NaCl solution to transfer the Au microelectrodes onto the hydrogel substrate. The optical micrograph shows a portion of the Au microelectrode array on the hydrogel substrates.
[0046] A donor substrate was coated with a sacrificial layer of water-soluble poly(acrylic acid) (PAA), which has 89.8±5.2 nm in thickness. Water stable PAA films were formed through ionic crosslinking with divalent Ca 2+ ions. Sacrificial ionically crosslinked PAA films are compatible with the microfabrication of superpositioned inorganic microstructures by photolithography, electrodeposition, and nanoimprinting. Au microelectrode arrays were patterned on PAA-Ca 2+ coated substrates by thermal evaporation through shadow masks. Au microelectrodes with thicknesses of ˜30 nm are commonly employed for electrodes and interconnects because this dimension preserves stretchability in Au thin films. PAA-Ca 2+ films are stable during conformal lamination of swollen P(HEMA-co-DMA) hydrogels.
[0047] FIGS. 9A-9C show representative macroscopic images showing transfer printing of Au microelectrode arrays. FIG. 9A shows PAA-Ca 2+ /Si donor substrates transferred to adhesive P(HEMA-co-DMA) hydrogel target substrates (See FIG. 9B ). FIG. 9C shows P(HEMA) hydrogel substrates. The transfer yield of P(HEMA-co-DMA) target substrates was significantly larger compared to P(HEMA). Scale bars all represent 0.5 mm.
[0048] Sacrificial PAA-Ca 2 films eliminated non-specific adhesion between the hydrogel and the donor substrate, thereby preserving integrity of target hydrogel substrates and increasing the yield of transferred microstructures. Dissolution of sacrificial PAA-Ca 2 layers by monovalent cation exchange promoted separation of adhesive P(HEMA-co-DMA) target substrates from donor substrates. Au microstructures can be transferred from Si donor substrates to swollen P(HEMA-co-DMA) hydrogel target substrates (10:1.23 ratio of DMA to HEMA) with yields (>99.5% as measured by the total area ratio of (A μelectrodes, target /A μelectrodes, donor ) that are significantly higher compared to P(HEMA) target substrates (<20%), as shown in FIGS. 9A-9C . Au microelectrodes adopt a buckled, but largely crack-free morphology (˜98% microstructures are crack free) after being transferred to target P(HEMA-co-DMA) hydrogel substrates. Buckled features form due to the modulus mismatch between the Au thin film and the hydrogels in addition to transient deformation of hydrogels during transfer printing. FIG. 6 shows a comparison of different substrates for microelectronic structures.
[0049] FIG. 4 shows optical micrographs of Au microelectrode arrays when the P(HEMA-co-DMA) substrate is cycled between hydrated and dehydrated states. As seen in FIG. 5 , values for extracted resistance of Au microelectrodes (n=8) indicate the electrical conductivity is preserved for 5 hydration/dehydration cycles. The inset shows the linear current-voltage characteristic of the Au microelectrodes before 1 st dehydration and after the 5 th dehydration.
[0050] Buckled microstructures may be beneficial by increasing the maximum permissible strain of electrically conductive films. Au microstructures adhered to P(HEMA-co-DMA) hydrogel substrates during cycles of hydration and dehydration ( FIG. 3 b ). P(HEMA-co-DMA) hydrogels have a swelling ratio of Q=(m swollen /m dry ) n=1 =4.89±0.22 where n is the hydration/dehydration cycle number. Dimensional swelling can be calculated via (L swollen /L dry ) n=1 =Q 1/3 =1.70±0.02 assuming isotropic swelling. Dimensional swelling is reduced for cycles n>1 via (L swollen /L dry )n =1, avg. =1.63±0.05. The decrease in the dimensional swelling after the first cycle is likely due to the formation of additional physical crosslinks between pendant catechol groups during the first dehydration cycle. The swelling ratio is measured either gravimetrically or from changes in volume of the hydrogel.
[0051] As shown in FIG. 5 , the resistance of Au microelectrodes was measured using two-probe current-voltage measurements. The end-to-end resistance R Au of the as-transferred Au microelectrode was calculated to be 14.9±1.1 Q prior to the first dehydration. As shown in FIG. 5 , the electrical conductivity of Au microelectrodes on P(HEMA-co-DMA) hydrogels is largely constant for hydration/dehydration cycles for up to n=5 (R Au =12.8±0.7Ω for the dehydrated state of n=5). For cycles n>5, no delamination of the Au microelectrodes was observed, which indicates the adhesion between the Au thin film and P(HEMA-co-DMA) hydrogel substrate is preserved. As shown in FIG. 10 , minor fissures in some microelectrodes form due to fatigue, which could be potentially relieved by incorporating strain-relief designs such as the serpentine patterns into the microelectrode geometry.
[0052] Hydrogel-based electronics afford unique advantages compared to devices fabricated on flexible and stretchable substrates for certain biomedical applications. Microfabricated electrode arrays in which inorganic structures are integrated with highly compliant hydrogels permit electrophysiological monitoring of excitable tissues in native mechanical environments. Electronically active structures fabricated on HEMA-based polymer networks also lead to the next-generation of smart contact lenses capable of diagnostic and therapeutic functions. Other applications include conformal sensors for measuring EEG, electrochemical sensors, laminated sensors for monitoring cardiac activity, or other sensor/stimulation combinations for use with stimulating/monitoring cells cultured on hydrogel-based substrates.
[0053] FIG. 10 shows an optical micrograph shows the formation of microcracks (indicated by regions with dashed lines) in the microelectrode at the hydrated state of 61 hydration/dehydration cycles. Scale bar represents 50 mm.
[0054] As shown in FIGS. 11-12 , catechol-bearing P(HEMA-co-DMA) target hydrogel substrates also exhibit increased adhesion with many film compositions, which is promising for fabricating devices with multiple materials. Functional devices fabricated on hydrogels facilitate integration of electronic structures with tissue through minimally invasive procedures. The fabrication strategy of the present invention melds swollen hydrogel substrates with conventional vacuum-based device microfabrication techniques for potential applications in soft bio-hybrid robots, actuators, and mixed charge conducting media.
[0055] FIG. 11 shows composition-dependent transfer printing of various metals with P(HEMA-co-DMA) hydrogels of varying DMA concentrations. Bi-layer metallic thin films are composed of 10 nm of a metal film laminated to a 40 nm bottom layer composed of Au. The composition of the top layers included Al, Cu, Ag, Au, and Pt. Al, Cu, Ag and Au films are deposited on SiO 2 /Si substrate surfaces by thermal evaporation while Pt films are formed by sputtering. The 40 nm Au bottom layer was used to ensure that all bi-layer thin films have same adhesion values W Au-SiO2 with the donor substrate.
[0056] P(HEMA-co-DMA) are prepared with DMA loadings c DMA including 0, 4.6, 7.6, 10.7 mol/mol % while total monomer concentrations of HEMA and DMA were held constant at 97.5 mol/mol %. P(HEMA-co-DMA) hydrogel substrates were laminated on donor substrates and kept in contact for 5 minutes before gradual delamination.
[0057] FIG. 12 shows macroscopic images including the transfer printing results with SiO 2 /Si donor substrates placed on the left and P(HEMA-co-DMA) target substrates placed on the right. The transfer printing results indicate transfer printing yields increase with increasing DMA loadings.
[0058] P(HEMA-co-DMA) with 10.7 mol/mol % DMA can transfer bi-layer metallic films of any composition with yields higher than 99% (areal coverage). The critical DMA concentrations such that C DMA, critical (W HEMA-co-DMA-metal ) C DMA, critical ≈W Au-SiO2 occurs between 4.6-7.6 mol/mol %. P(HEMA-co-DMA) hydrogels with C DMA <5 mol/mol % cannot transfer metallic films of any composition to target substrates. Macroscopic images show hydrogel substrates in the dehydrated state. Defects shown in the Au+0 mol/mol % DMA case are caused by the fixation clapping during thin film deposition.
[0059] In some implementations, the target hydrogel substrates are prepared as described below. Dopamine hydrochloride is prepared as described above to produce catechol-bearing monomer dopamine methacrylamide (DMA). Briefly, dopamine-HCl (26.4 mmol) is reacted with methacrylate anhydride (29.1 mmol) in 25 ml of tetrahydrofuran. The pH of the solution is kept above 8 during the reaction by adding 1 M NaOH dropwise as necessary. In some implementations, the solution is washed with ethyl acetate, combined with hexane, and held at 4° C. for 18 hr.
[0060] As shown in FIG. 7 , purified DMA can be analyzed using 1 H nuclear magnetic resonance. In some implementations, hydrogel precursors including monomers 2-hydroxyethyl methacrylate (HEMA) and DMA, crosslinker polyethyleneglycol dimethacrylate (PEGDMA, Mw=1000) as well as photoinitator 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylpropiophenone (Irgacure 2959) are dissolved in a 1.88 mL solvent mixture containing 79.8% deionized water (DI H20) and 20.2% dimethyl sulfoxide to yield a solution with a total precursor concentration of 1.58 M.
[0061] In some implementations, P(HEMA-co-DMA) hydrogels contain 86.8 mol/mol % HEMA, 10.7 mol/mol % DMA, 1.7 mol/mol % PEGDMA, and 0.8 mol/mol % Irgacure 2959. In some implementations, precursor solutions for P(HEMA) hydrogels contain 97.5 mol/mol % HEMA, 1.7 mol/mol % PEGDMA, and 0.8 mol/mol % Irgacure 2959. In some implementations, other ratios are possible. For example, any ratio is possible as long as the molar ratio of catechol groups (e.g., dopamines) exceeds 5 mol/mol %. In some implementations, the solution can include 5 mol % DMA to 50 mol % DMA or more. Hydrogel precursor solutions are photocrosslinked into films 1 mm in thickness using Teflon coated glass slides at 600 mW/cm 2 UVB lamp for >60 sec. Hydrogels are equilibrated in DI H 2 0 for 24 hours after photocrosslinking. In some implementations, the films can be a thickness in the rage of 100 nm to 10 mm. In some implementations, compositions of hydrogels having at least 5 mol % catechol concentrations can be used.
[0062] Microelectrode fabrication on donor substrates can include several processes. In some implementations, Si/SiO 2 donor substrates are cleaned using a sequence of acetone, isopropanol, and DI H20 solvents followed by UV ozone. Poly(acrylic acid) sodium salt solution (PAA-Na + ) (M w −31,000-50,000) is diluted in DI H 2 O to a concentration of 5% (w/v). PAA-Na+ solution was spin coated on donor substrates at 3000 rpm for 40 seconds to form sacrificial release layers. In some implementations, donor substrates are annealed at 150° C. for 2 min and treated with 5 M CaCl 2 solution for 5 min. Au microelectrodes (nominal length=200 μm, width=2 mm, and spacing between two adjacent electrodes=100 μm) can be patterned on sacrificial layers by thermal evaporation using shadow masks (Au thickness=30 nm, 0.2 A s −1 . Other configurations of microelectrode arrays are possible, such as alternative thicknesses, spacing, and length or width according to design preferences.
[0063] Transfer printing of thin-film structures to target hydrogel substrates can include several processes. Target hydrogel substrates are conformably laminated onto the donor substrates surface. In some implementations, the donor substrates surface remains in contact for 5 minutes without external heat or pressure. Hydrogel substrates were delaminated from donor substrates in 1 M NaCl solution.
[0064] The chemo-mechanical characterization of hydrogel target substrates can be measured as described below. Fourier transform infrared (FTIR) spectra of dehydrated gels were recorded for wavenumbers from 4000-400 cm −1 . In some implementations, the mechanical properties of hydrogels are measured using a rheometer. Adhesion measurements utilize cylindrical swollen hydrogels (h=1 mm, D=20 mm) that were mounted on a polystyrene petri dish using cyanoacrylate adhesive and submerged in 4 mL of DI H 2 O. Flat cylindrical glass windows (D=5 mm) are coated with metallic bilayers composed of Cr/Au (5 nm, 30 nm; 0.2 A s −1 ) by thermal evaporation. In some implementations, the indenter can be mounted on a 250 g load cell attached to a stack of a vertical motorized stage for indentation and two manual tilting stages for controlling the alignment. Custom-made software controls the motorized stage, while recording the measured loads at a 1 kHz sampling rate.
[0065] In each experiment, the indenter was preloaded against the hydrogel sample with forces between 10-50 mN and the software controlled the stage as needed to maintain a constant preload for a fixed contact time of 5 min. The indenter was then retracted with a constant speed between 10 mm s −1 -1 mm s −1 and force-distance curves were recorded. The actual measured preloads deviated slightly from the nominal values due to the effects of buoyancy (˜1 mN). The actual measured preloads deviated slightly from the nominal values due to the effects of buoyancy (˜1 mN). The actual measured preloads deviated slightly from the nominal values due to the effects of buoyancy (˜1 mN). The effect of capillary force interactions is negligible under the complete submerged conditions of adhesion measurements.
[0066] FIG. 8 shows representative force-distance curves of both P(HEMA-co-DMA) and P(HEMA) hydrogels when retracting the Au-coated indenter at different velocity values including 0.01, 0.1, and 1 mm s −1 . At the same retracting speed, adhesive P(HEMA-co-DMA) hydrogels show both larger tensile work and higher maximum tensile force for the delamination between the indenter and the hydrogel surface compared to P(HEMA) controls.
[0067] The thin-film microstructure can include one, several, or all of the following characteristics. The I-V characteristics and resistance of the Au microelectrodes on adhesive hydrogels are measured using two-probe measurement in ambient conditions using an S-1160A probe station equipped with SE-TL tungsten probe tips bonded with soft Au wire (25 mm diameter and a source measuring unit (2400 SMU). During cycles of hydration/dehydration, the adhesive hydrogel substrates are dehydrated under 1 bar vacuum for ˜12 hours to reach the dehydrated state and then rehydrate in DI H 2 O for ˜12 hours to reach the hydrate state. Optical micrographs are recorded using an Olympus BH2 microscope. All data presented as mean±s.d. unless otherwise stated.
[0068] Other embodiments are within the scope and spirit of the description claims. The use of the term “a” herein and throughout the application is not used in a limiting manner and therefore is not meant to exclude a multiple meaning or a “one or more” meaning for the term “a.” Additionally, to the extent priority is claimed to a provisional patent application, it should be understood that the provisional patent application is not limiting but includes examples of how the techniques described herein may be implemented.
[0069] A number of exemplary embodiments of the invention have been described. Nevertheless, it will be understood by one of ordinary skill in the art that various modifications may be made without departing from the spirit and scope of the techniques described herein.
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This document describes a conformable substrate that includes a hydrogel having adhesion-promoting moieties, said adhesion-promoting moieties comprising one or more catechol groups. The conformable substrate includes an array of microelectrodes bonded to the hydrogel by the adhesion-promoting moieties via the one or more catechol groups. This document also describes a method for transfer printing of an electronic structure to a hydrogel. The method includes the steps of coating a donor substrate with a film of polyacrylic acid, crosslinking the film of polyacrylic acid in a solution comprising divalent ions, patterning a microelectrode array onto the crosslinked film of polyacrylic acid, laminating an adhesive hydrogel substrate onto the donor substrate coated by the crosslinked film of polyacrylic acid comprising the patterned microelectrode array, and separating the crosslinked film of polyacrylic acid from the donor substrate in a monovalent solution.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention was developed to safely reduce the rolling resistance of a vehicle, thereby increasing gas mileage. For this invention increasing gas mileage or miles per gallon will be used but in the case of electric vehicles one would substitute “increasing miles per charge”.
The present invention relates to a pneumatic or gas-filled tire and wheel assembly for attachment to any and/or all hubs of a motor vehicle both front and rear. For the purposes of this invention, a tire that has been mounted on a rim is defined as a wheel. When the three wheels outlined in the invention have been assembled they are defined as the TTAssembly (Triple Tire Assembly). Each TTAssembly comprises two interchangeable small diameter wheels and one large diameter wheel. See FIG. 8 . The two interchangeable small diameter wheels are mounted on each side of the large diameter wheel creating the TTAssembly. See FIG. 5 .
The TTAssembly must be mounted in pairs and would be mounted on each hub of the vehicle for maximum efficiency. See FIG. 9 . The TTAssembly could also be mounted on just the front hubs of the vehicle, but the efficiency would be greatly reduced.
Since it is well known that narrower tires produce less rolling resistance and hence save gas, they are an obvious choice for the large diameter tire. It is also well known that the more tire surface area contacting the road, the more traction and support the vehicle will have. This makes for a safer driving experience, but will reduce gas mileage. It is also well known that a tire assembly with three separate air chambers is safer than a tire with two or one air chambers, thus this invention eliminates the need for a spare tire. While each individual choice above may seem obvious, developing a practical combined solution focused on increasing gas mileage while maximizing safety has eluded those knowledgeable in the subject for years. This invention is the perfect solution to maximize gas mileage and reduce cost while providing safety.
The operation of the TTAssembly is uniquely simple. As the vehicle travels in a straight line, the large diameter wheel of the TTAssembly contacts the roadbed. The narrow footprint of the large diameter wheel maximizes the gas mileage. As the vehicle enters a turn, the TTAssemblies on the front of the vehicle are tilted either left or right due to a camber change of the vehicle. See FIG. 2 . When the camber change is large enough it causes one of the small diameter wheels of each of the TTAssemblies on the front of the vehicle to contact the roadbed in addition to the large diameter wheel. This increases each TTAssemblies footprint on the roadbed making the turning of the vehicle safer. This transfer to the wider footprint occurs passively, without electronic, computer, or human-controlled mechanisms or pumps, and is seamless to the driver. If the vehicle weight is within its operating parameters and the tires selected are based on the manufacturers recommendations this passive transfer will be irrespective of the weight of the vehicle during normal operation. In panic or emergency stops all large diameter tires in the TTAssemblies will experience deformation, see FIG. 10 , due to the braking forces on the front tires and braking forces on the rear tires. These braking forces are at the roadbed level. The inertia of the vehicle acting against the braking forces creates a rotating tendency, or torque, about the center of gravity of the vehicle. While the downward force on the front tires increases, the weight of the vehicle has not increased. In the case of a four wheel vehicle, that would put all twelve tires in the TTAssemblies in contact with the roadbed. Since it is well known that approximately 50% of the weight on the rear axle of the vehicle is transferred to the front tires during a hard stop, having the TTAssembly on all hubs of the vehicle is optimum.
The TTAssembly also offers a major benefit to the vehicle owner and the tire stores. Since the two smaller diameter wheels are interchangeable, it would be impossible to mount them on a vehicle incorrectly. Money would be saved because inventory could be reduced up to 60%, no spare tire is required, significant increase in miles per gallon is realized and there is reduced wear on the smaller diameter tires.
Additional benefits to the TTAssembly come in the form of types of tires that could be used. If snow tires were mounted on the inboard and outboard rims, the resulting ride would be much smoother and quieter than that of a regular snow tire during straight line driving. Chains could be mounted on the inboard and outboard tires and would not contact the road until the vehicle was turning or the snow was deep enough to contact the smaller diameter wheels. This would eliminate the daunting task of putting on chains in the snow. Four wheel drive or off-road vehicles could also use the TTAssembly. This would allow them to drive on paved roads to their destination and then drive off-road, like on sand dunes, where the wide or paddle-wheel or other fancy smaller diameter tires could come into contact with the surface. This would eliminate the need for trailering the vehicle or changing tires once the destination was reached. Military vehicles would benefit from reduced exposure to flat tires and could drive into non-paved areas without stopping to change tires. For sports cars, having the large diameter tire of the TTAssembly be the same width or even wider than the small diameter inboard and outboard tires might be appropriate in some instances. It would reduce gas consumption somewhat and eliminate the need for a spare tire in a typically miniscule trunk.
2. Description of Related Art
A high profile or narrow taller tire may be defined as a tire having a comparatively high aspect ratio, or height-to-width ratio, where the height is the distance measured radially from the tire's outer diameter to the rim opening or rim seat. A narrow, taller tire is preferred where fuel economy, low road noise, and ride quality are the main operational concerns. However, narrow taller tires do not have ideal handling characteristics in terms of steering, acceleration, and braking in aggressive driving conditions such as rainy conditions, sudden obstacles, or other condition where a large degree of safety or performance margin is required. A wider tire, also referred to as low profile or low aspect ratio, may be preferred for vehicles intended for high-performance handling, aggressive driving conditions or carrying heavy loads. However, wider tires or dual tires do not perform well in terms of fuel economy, road noise, ride quality, and tire wear. Tire selection typically involves compromise, sacrificing certain desirable performance characteristics for others such as performance or safety verses gas mileage. Vehicles such as family sedans or mini vans, which are mainly intended for comparatively sedate driving styles and straight-line highway driving, are typically fitted with softer riding taller tires with an aspect ratio of 70% to 80%. These narrower taller tires give them better gas mileage. Sports cars are commonly fitted with wider low aspect ratio tires in the 30% to 50% range. Trucks use dual tires on the rear wheels which are inherently wider to add stability, increase load capacity and improve traction and the like. Each of these compromises is acceptable when the vehicles in question are being operated according to their primary intended functions, but both suffer from significant drawbacks when operational conditions change. A vehicle riding on narrow taller tires requires slower speeds to navigate narrow, winding roads where tight cornering and hard braking may be required, especially when traction is poor due to rough, wet, or icy road surface conditions. In contrast, a vehicle with wider tires or dual rear tires generally handles much more responsively under such adverse conditions than if it had taller narrower tires, but it will give a rougher and noisier ride, with poorer fuel economy.
Prior art discloses numerous attempts to provide vehicle tire systems that use multiple-tire assemblies to adapt to different operating conditions. Elkow (U.S. Pat. No. 6,615,888) discloses a variable diameter wheel apparatus that uses a pump to inflate or deflate each tire independently to achieve optimum performance from a multiple tire arrangement. Sensors monitor selected operational parameters of the vehicle and transmits corresponding signals to a computer that selects an optimal tire configuration. Blomquist (U.S. Pat. No. 2,751,959) discloses a tire-and-wheel assembly having a selectively-inflatable auxiliary tire coaxially on a specialized telescoping rim and axle assembly, disposed between two conventional tires. The auxiliary tire has an accordion-like construction. The diameter of the auxiliary tire when un-inflated is less than that of the two conventional tires, so the auxiliary tire is not in contact with the road surface when it is un-inflated. When inflated, its diameter expands to match that of the conventional tires, and it also expands laterally, displacing the outboard conventional tire further outboard. Accordingly, inflation of the auxiliary tire greatly increases the total width of the wheel assembly and the total area of tire contact with the road surface, thereby providing improved traction. O'Brien (U.S. Pat. No. 5,788,335, U.S. Pat. No. 5,810,451, U.S. Pat. No. 6,022,082) discloses a studded, selectively inflatable auxiliary tire of specialized construction that is coaxially disposed between two conventional rear tires. As in Blomquist, the un-inflated diameter of the auxiliary tire in the O'Brien patents is less than that of the conventional tires. Upon inflation, the auxiliary tire expands in diameter, but does not expand laterally as in Blomquist, until it substantially matches the diameter of the conventional tires, such that the studs of the auxiliary tire may engage the road surface. The auxiliary tire thus must be manually inflated or deflated, to suit particular road conditions.
The inventions disclosed in the O'Brien patents cited above are directed primarily to providing rear wheel enhanced traction on slippery road surfaces, with the means for providing enhanced traction. This functionality is not passive. It requires the driver to stop and physically make changes to the vehicle to change from one state to another. It would be reckless to drive a vehicle on a clear dry road with the studs engaged. The studs would tear up the road until they were worn down, which would happen quickly, rendering the traction device useless. If the traction device is engaged, i.e. expanded to larger than the inboard and outboard wheels, the vehicle will still ride on all three wheels. O'Brien states “The tire 24 is expanded such that the studs 20 will extend beyond the diameter of the wheels 12 , 14 to engage the supporting surface (roadway). The wheels 12 , 14 still supports the vehicle weight and the tire 24 provides the traction.” O'Brien's traction device is equivalent to adding chains to the outboard tire. It does not support any additional weight, requires a driver's interaction and will not increase gas mileage. Because the auxiliary tire is only used for traction and not for support, it would be obvious that the width of the auxiliary tire must be smaller than the width of the support tires as they are used for holding the side of the auxiliary tire. Otherwise the sidewall would buckle and traction would be non-existent. If the auxiliary tire were larger than the support tires the ability of the auxiliary tire to contract when not in use would compromise the ability to handle the torque required of a traction device.
The traction device rim outlined in the O'Brien patent has mounting holes that line up with the mounting lugs or bolts of the wheel housing. The additional thickness of the traction device rim, which allows for the mounting between two standard dual wheels, would require longer bolts from the hub. The rim would be custom for every configuration of dual wheels as the distance between the dual wheels is not consistent. In O'Brien's FIGS. 3, 5, 6 and 7 the rim is shown as flat. O'Brien's FIG. 5 shows that a spacer is used to allow enough space for the traction device to operate successfully. This traction device is not able to remove the heat build up from the traction device to allow it to operate at highway speeds, nor is it meant to. It is only good for providing studs, an alternative to chains that increase traction. Studded tires are allowed in 36 different states, and only between November 1st and March 31st. Alabama, Florida, Hawaii, Illinois, Louisiana, Mississippi, and Texas all ban studded tires completely. Revamping the studded to non-studded configuration while traveling in and out of these states would require a specialty tire service company and is not passive. The O'Brien patent would not work as the front tires of a vehicle. It requires the vehicle to have dual front tires with extended front axles to accommodate wheels with extreme positive offset that are expanded to fit the third tire in-between them. The additional cost of the tires, modifying the vehicle body as well as the strain on the vehicle components such as power steering and alignment components would not be feasible. On top of that, the turning radius of the vehicle quadruples making it almost impossible to drive except in a straight line.
Prior art discloses technology for increased traction and skid resistance on wet or icy roads while also addressing other objectives such as ride quality, fuel economy, or general handling characteristics. However, these attempts were different because they did not provide a safe tire assembly capable of travelling at highway speeds while delivering maximum fuel efficiency using tire assemblies with large and small diameter tires and a seamless, passive method of transfer between them.
Prior art discloses un-inflated or underinflated wheels that can be hazardous, can come loose from the rim, and get caught under one of the other functioning tires, creating a rollover situation. The designs add unnecessary weight, which decreases fuel efficiency, decreases braking ability, and could cause a rollover. If a pump fails, all four of the tires could be flattened, creating a crash prone scenario. If the computer, actuator, communication link, or any one of many sensors malfunctions, a life threatening condition arises. The central tire could expand as the vehicle goes around a sharp curve, removing all traction from the tires. The prior art involves complex traction mechanisms or tires of specialized construction with special sensors, computers, and pump configurations.
The Tawara patent (JP 58139802A) discloses a rear wheel assembly consisting of a two tire system with one large diameter tire and one small diameter tire. The purpose of the arrangement is to reduce wear on “double wheels for the rear wheels of a bus or the like” and as the weight of the vehicle increases, the smaller diameter tire contacts the road. The drawings for the Tawara patent show both rear wheels being the same width. Most prior art involves one or more conventional tires which are in load-bearing contact with the road surface at all times, regardless of whether the invention's particular traction enhancement or performance means are engaged, and regardless of the road conditions being travelled on. None of the prior art, except the Tawara patent provides a wheel/tire assembly that in itself provides a passive system that seamlessly transfers between large and small diameter tires at the precise instances or conditions required. The O'Brien patent requires that you stop and pump up or deflate the tire when conditions change. While Tawara does provide for passive transfer, it is based on changing the weight of the vehicle and will not change based on roadbed conditions, or vehicle direction change. In an emergency stop the Tawara patent becomes dangerous. Since it is the added weight in the vehicle that makes the second wheel contact the road surface, and since 50% or more of the weight is transferred to the front wheels in an emergency stop, the second wheel would be lifted off the ground reducing the frictional force on the rear wheels significantly increasing stopping distance. It cannot provide for optimum gas mileage. If the Tawara vehicle is lightly loaded, then it responds like a regular one wheel per hub vehicle. It would be obvious to one skilled in the art that a narrow tire on a high center of gravity vehicle, by itself, would be dangerous During a turn, the tall narrow tire would lower the friction side forces on the tire making a rollover more likely. This is especially true in a situation where narrow tires are used if the vehicle is top-heavy, such as a bus or a truck that would experience such stated vehicle weight increase that could deform Tawara's large diameter tire. It would be unsafe to operate with a high aspect ratio tire, therefore a wide tire would be required for the main roadbed-contacting rear wheels. Thus a significant gas savings cannot be achieved.
It would also be obvious to one skilled in the art that moving the Tawara patent idea to the front axle would be precluded. This is due to the fact that only one of the seldom used small diameter tires could contact the roadbed during a turn or obstacle avoidance maneuver causing a change in the tire width and frictional force on one side of the vehicle and not the other. This is also the case with the O'Brien patent as shown in his FIG. 6 . This could result in a loss of control of the vehicle. This is often seen when a space-saver spare is used on one side of an axle, and is only condoned as a very reduced speed emergency tactic.
When the Tawara vehicle is loaded, both rear tires contact the road surface, giving more vehicle support and traction but completely eliminating any gas savings. This cannot be changed until the vehicle is unloaded.
Prior art also shows that most dual and triple wheel rims are focused on mounting dual wheels with enhancements in place of single wheels on the rear hubs of campers, light and heavy duty trucks for adding stability, increasing load capacity improving braking and traction and the like. These designs require heavy duty construction to accomplish the increase in load capacity and the wide track for added stability. Large heavy duty inner and outer rims with adaptors, sleeves, struts, baskets or cup like assemblies that allow access to inner rims are required to meet these expectations.
The solid rubber wheel (roue à bandage plein) described by Vaillant (FR 1066702A) in FIG. 3 could not be used on today's passenger cars where speeds of up to 80 MPH are attained. The diameter of the solid tire(s) would have to be at close to rim level to mitigate accidents while turning, meaning that it never contacts the road unless there is a flat tire. The width of the center tire in FIG. 3 can be larger than the inside and outside solid non-road contacting rubber wheels. It was designed to compensate for a flat tire where one could limp (less than 20 miles per hour) to a gas station to have it fixed. This is not an operational vehicle when the center tire is flat. He states that his invention protects the vehicle from projectiles that would impale a pneumatic tire. This was 1954, with large V8 engines where gas was cheap and horsepower was king. The leap from a device that must use solid rubber wheels to function as a “run flat” device located at or near the outside radius of the rim, to a device that requires pneumatic tires, that are in contact the road surface to increase gas mileage would not be predictable, but an accidental discovery, like vulcanization.
The TTAssembly invention is completely different. It is designed for all four vehicle hubs. Its main goal is not to carry additional weight or gain more traction but to safely increase miles per gallon. The invention is designed to replace a standard wheel, not require specially formed fenders or body parts to accommodate the additional width of a multiple tire system. The invention is fully reversible and could be bolted to the vehicle hub from either side. According to prior art, if the rims on a dual wheel system could be mounted in the reverse direction, the dual wheels would extend out further from the vehicle, thus producing undesirable performance characteristics.
BRIEF SUMMARY OF THE INVENTION
The present invention is assembled using three tires and three rims and mounting hardware for mounting on a motor vehicle hub as a replacement for a conventional single vehicle tire/rim assembly in order to safely maximize gas mileage. It requires no vehicle modifications and reduces costs. The invention includes an assembly of three coaxially mounted wheels: two small diameter wheels consisting of an inboard rim and an outboard rim each mounted with two identical small diameter tires, and one large diameter wheel consisting of one center V rim mounted with one large diameter tire. All three rims have the same diameter, while the tire diameters are different. The two small diameter wheels are located inboard and outboard of the assembly with the large diameter wheel located in the center. This assembly is called the TTAssembly (Triple Tire Assembly). The larger diameter tire will always be in contact with the road surface over which the vehicle is travelling.
Assuming the vehicle has four tires, at slow speeds or straight driving when rolling resistance is a large factor in determining gas mileage, the large diameter tires will be the only tires in contact with the road surface. This is the default condition. While turning, or other maneuverings, the inboard small diameter tire from one of the TTAssemblies on the front of the vehicle and the outboard from the other TTAssembly on the front of the vehicle will contact the roadbed in addition to the large diameter tire, yielding more surface area for the vehicle to ride on.
During a panic or emergency stop all of the large diameter tires in the TTAssemblies (both front and rear) will deform causing all of the tires to contact the roadbed. This is especially critical for the front assemblies as 50% of the rear axle weight is transferred to the front assemblies during a panic stop. As soon as the increased force is removed the large diameter tires will resume their previous shape and the vehicle will resume riding on only the large diameter tires. The vehicle will be most efficient when all hubs of the vehicle have the TTAssemblies installed on them. As is standard practice, each axle must have identical wheel assemblies.
Tires may be constructed of standard material already known in the art of tires. Rims are cylindrical and constructed of rigid material already known in the art of rims. Standard connecting hardware is used and is already known in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cut-away view showing zero Camber Angle
FIG. 2 is a cut-away view showing some degree of camber
FIG. 3 is a cross-sectional view of the assembled invention
FIG. 4 is a side elevation view of the assembled invention
FIG. 5 is a front elevation view of the assembled invention
FIG. 6 is an exploded cross-sectional view of the invention showing identical small diameter rims.
FIG. 7 is an exploded cross-sectional view of the invention showing the optional non-identical small diameter rims.
FIG. 8 is an exploded perspective view of the invention
FIG. 9 is a view of the TTAssembly mounted on all 4 hubs of a vehicle
FIG. 10 is a cut away view showing TTAssembly during hard stop
DEFINITION LIST
Term Definition
1 Vertical axis of the vehicle perpendicular to the road surface (Camber Angle=0)
2 Vertical axis of the TTAssembly
3 Inboard small diameter tire
4 Outboard small diameter tire
5 Center large diameter tire
6 Inboard rim
7 Outboard rim
8 Center V rim
9 Center rim Wedge Tip
10 Threaded hole to accept stud
11 Thru-hole in rim with beveled edge to accept lug nut
12 Threaded Stud
13 Lug Nut that fits on Threaded Stud
14 TTAssembly
15 Mounting holes to fit wheel studs for vehicle hub
16 Roadbed surface
17 Difference in height between large diameter wheel and the small diameter wheels
18 The Camber Angle
19 Center large diameter rim mating hole
20 Optional inboard rim
21 Thru-hole in rim with beveled edge to accept lug nut
22 Width of inboard small diameter tire
23 Width of outboard small diameter tire
24 Width of center large diameter tire
DETAILED DESCRIPTION OF THE INVENTION
The invention includes an assembly of three coaxially mounted wheels so that the center of each tire and rim are aligned and each tire and rim are concentric around the longitudinal axis of the axle attached to the hub. This ensures that the TTAssembly rotates around the axle when properly attached to the hub. The TTAssembly is composed of: one inboard small diameter wheel consisting of one inboard rim 6 mounted with one inboard small diameter tire 3 ; one large diameter wheel consisting of one center V rim 8 mounted with one center large diameter tire 5 ; and one outboard small diameter wheel consisting of one outboard rim 7 mounted with one outboard small diameter tire 4 . The two small diameter wheels are located inboard and outboard of the assembly with the large diameter wheel located in the center of the assembly.
The width of the inboard tire 22 and the outboard tire 23 are identical, whereas the width of the large diameter tire 24 can be smaller, equal to, or larger than the inboard 22 or outboard 23 tires.
Four threaded studs 12 and eight lug nuts 13 connect the TTAssembly together. Note that the inboard rim 6 and the outboard rim 7 are identical.
Connection is made by placing the threaded stud 12 through the outboard rim 7 thru-hole 11 , through the center V rim 8 mating hole 19 and through the inboard rim 6 thru-hole 21 .
Two lug nuts 13 are threaded onto each end of stud 12 . This is duplicated for the remaining three studs and six lug nuts. Lug nuts are then tightened forcing the outboard rim 7 and the inboard rim 6 against the center rim wedge tip 9 . The “V” shape on the center wedge tip 9 on the center V rim securely holds the three rims together while carrying heat away from the tire. All three rims, inboard, center V and outboard have the TTAssembly thru-holes evenly spaced around the rims and all thru-holes are equidistant from the center of the vehicle hub.
FIG. 7 shows an optional version where the inboard rim 20 has a threaded hole 10 to accept the stud 12 , reducing the number of lug nuts 13 required.
All three TTAssembly rims have the same diameter and have a “standard” 4 bolt pattern in the upper portion of the rim regardless of the bolt pattern (4, 5, 6, 8, etc) on the vehicle hub. This reduces the inventory requirements by 80% and increases the potential for fast turnaround service.
The number of rims and tires used in the invention is the same. The TTAssembly may be mounted to a vehicle hub by any means. The standard means utilizes the existing threaded studs permanently attached to the vehicle hub where the TTAssembly is sandwiched between the vehicle hub and a lug nut securely tightened onto each stud.
The invention is easily modified to accept any sort of vehicle hub stud configuration 15 . The center V rim 8 and the inboard 6 or 20 and outboard 7 rims may be manufactured in any of the current arts of rim making. In all cases, each tire has its own air chamber and pair of bead seals or other appropriate seals between rim and tire members required to contain gas in the tire chamber under high pressure. The design is modular where each rim is a separate component and the rim fastening means is reversible so that rims may be easily connected together and easily disconnected. In case of wear, weather or hazard the modular design of the invention allows for easy maintenance. The replacement of perhaps only one tire or wheel of the whole assembly can be accomplished without requiring replacement of any other component. This maintenance can be accomplished at a regular tire shop, vehicle repair shop, or home garage. This is a major cost savings. In addition, due to the fact that there are 3 air chambers in the TTAssembly per hub, a spare tire is not required, saving more money, weight and space.
In order for the passive transfer aspect to perform properly with ample safety or tire traction, special care must be taken in the shape and design of the tires and rims. Large diameter tires must be specially shaped to yield the appropriate efficiency characteristics while also yielding the appropriate transition characteristics. Transition occurs when the vehicle is turning, resulting in a camber angle change. FIG. 1 and FIG. 2 show that camber is the angle 18 between the vertical axis of the TTAssembly 2 and the vertical axis of the vehicle 1 when viewed from the front or rear. Camber angle 18 is primarily used in the design of steering and suspension. When the steering wheel is turned causing the TTAssembly to turn, the camber angle 18 changes. This angle change will cause the small diameter tire to come into contact with the roadbed 16 when the angle is large enough. The larger the camber angle 18 , the more this occurs. Transition can also occur during an emergency stop. During a panic or emergency stop the sudden stopping force on all of the large diameter tires in the TTAssemblies (both front and rear) will deform causing all twelve of the tires to contact the roadbed. See FIG. 10 . This is especially critical for the front assemblies as 50% of the rear axle weight is typically transferred to the front assemblies during a sudden stop. As soon as the increased force is removed the large diameter tires will resume their previous shape and the vehicle will resume riding on only the large diameter tires. The vehicle will be most efficient when all hubs of the vehicle have the TTAssemblies installed on them. As is standard practice, each axle must have identical wheel assemblies.
As every vehicle will react differently based on its camber, turning radius, center of gravity and wheelbase a standard starting point would be to have the small diameter wheels to have a diameter of 28.9 inches and a width of 4 inches and the center large diameter tire to have a diameter of 30 inches and be 2 inches, wide. This instantiation produces a combined standard size tire width of 10 inches or 255 mm, which would easily replace a single tire/rim combo having a width of 255 mm. This is a standard size on many vehicles.
It is the perfect invention because no customization to the vehicle is required to use the TTAssembly, it saves gas, saves money, is easy to maintain and there is no need for a spare tire saving space and weight.
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The TTAssembly is a three tire and rim wheel assembly. The assembly consists of a large diameter center wheel with two identical smaller diameter wheels on the inboard and outboard sides respectively. The TTAssembly replaces the standard single rim single tire assemblies on a vehicle hub, maximizing gas mileage and the safety requirement of the vehicle. It also reduces maintenance costs and eliminates the need for a spare tire.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to tissue evaluation and treatment. Physical therapists are trained to evaluate and treat a wide variety of musculoskeletal conditions including muscle strain, joint sprain as well as insidious onset of spine and extremity pain. Tissue evaluation involves techniques including assessment of joint range of motion (ROM), extremity flexibility, and strength testing. Patients rely on a these specialists to provide an extremity flexibility evaluation with a goniometer reported in degrees. Measurement of extremity flexibility is referred to as “evaluation”. Extremity treatment provided by specialists often includes includes passive stretching, massage and strengthening exercises. Home-based treatments including passive stretching are prescribed by medical professionals to reduce patients' long term pain. Passive stretching by medical professionals is a common treatment which increases extremity flexibility to relieve lower back pain, patellofemoral syndrome (knee pain), nerve entrapment (sciatica), plantar fasciitis, achilles tendon tightness, and various tendonopathies. Treatment regimens include a stretch intensity, duration, and frequency of each exercise. Patients perform prescribed treatments at home by using a towel, belt, or a strap such as the “stretch-out-strap” by OPTP products. Stretching to increase extremity tissue length and flexibility is referred to as “treatment”.
[0002] At home, many patients do not have a way to evaluate their flexibility and often fail to comply with the prescribed treatment regimen. Over time tissue stiffness increases and reduces muscle-sinew tissue compliance, noted as the degree to which the muscle-sinew tissue complies to treatment. This decrease in muscle-sinew tissue compliance often leaves patients wondering what their flexibility is and what treatment regimen to follow to achieve acceptable flexibility. The solution to evaluating their flexibility and determining the new treatment regimen is to return to the clinic, have a physical therapist evaluate their tissue flexibility using a goniometer and prescribe a flexibility treatment regimen. This can be a costly, time consuming, and often painful approach to maintaining optimal flexibility.
BRIEF SUMMARY OF THE INVENTION
[0003] The known handheld tissue stretching devices do not allow the user to objectively evaluate tissue flexibility nor provide a consistent treatment treatment intensity because of the constant repositioning needed to change treatment intensity. Evaluating and treating tissue with existing handheld devices leaves the user wondering whether or not he has stretched properly. Pain is often the feedback individuals use to determine their extremity flexibility regimen. Over time, changes in compliance of the muscle-sinew tissue may alter the needed treatment regimen making a proper evaluation and treatment regimen even more difficult for the user. Combining a reliable extremity flexibility evaluation with a handheld tissue stretching device eliminates pain as the primary means for feedback and provides other benefits such as minimizing trips to the physical therapy clinic, decreasing the risk of activity-based injuries, and optimizing tissue treatment intensity, duration and frequency to achieve desired extremity flexibility. Individuals now have the option of reliably and independently evaluating their extremity flexibility and property treating their muscle-sinew combinations before engaging in activities such as walking, running, sports or work activities.
[0004] In accordance with the invention, a handheld tissue stretching device combined with an extremity flexibility number enables users to reliably and independently evaluate and treat the flexibility of their extremity tissue; thereby, minimizing physical therapist intervention to evaluate and prescribe a treatment regimen. Similar to a scale used to measure an individual's weight, the extremity flexibility number provides an immediate evaluation of a user's extremity flexibility. Until now, patients have depended upon someone else to determine their flexibility values and issue a flexibility treatment regimen to be done in accordance with this evaluation. The present inventors, however, have recognized that combining a handheld tissue stretching device with an extremity flexibility evaluation, in the form of an extremity flexibility number, will provide users with a simple indicator of extremity flexibility. Such an extremity flexibility number is referred to herein as a “stretchscore”.
[0005] Treatment intensity is carefully monitored by medical professionals by verbal, visual and manual inspections to provide a consistent treatment. Outside of the clinic however, handheld passive stretching devices cannot provide users with a reliable and consistent treatment. The known treatment devices have an extremity support, to engage the extremity to be treated, and link between the extremity and the users hands. The user changes the intensity of the stretch by pulling the extremity support is engaged with the extremity. Pulling the extremity increases muscle-sinew tissue length of the tissue being treated. The user has to reposition his hands on the device or move his hands relative to the extremity support to change stretch intensity. The distance between the users hands and the extremity support remains constant and the user has to reposition his hands, this repositioning is inconsistent and imparts a high degree of intensity variability during treatment. When patients are performing home-based stretches, variable intensity can lead to inconsistent tissue treatment resulting in increased tissue stiffness. The present inventors have discovered a way to increase stretch intensity consistency during self treatment of muscle-sinew tissue. When a user increases the stretch intensity, the slack in the pliable, inelastic link, caused by pulling the extremity, is automatically retracted, and the distance between the users hands and the extremity support is continuously proportional to the tissue length of the extremity. This “distance matching” between the handheld stretching device and the extremity support provides a reliable, repeatable, and independent treatment method and evaluation of extremity flexibility. This method of treatment, when used in combination with a stretchscore, provides an evaluation of tissue flexibility to the user ensuring a consistent and purposeful treatment regimen.
[0006] In another embodiment, pulling force may be used to indicate the stretchscore. Treatment intensity is directly matched to the amount of force the user imparts on the extremity when pulling on the extremity support. The amount of force needed to stretch an extremity is referred to as “passive resistance to stretch” or tensile force of the muscle-sinew tissue. Tests showed this pulling force ranged from about 4 pounds force to about 20 pounds force. Decreasing passive resistance to stretch at a given range of motion increases tissue flexibility; this is known as the viscoelastic effect. The present inventors have discovered a consumer friendly way to translate the “passive resistance to stretch” into an evaluation of tissue flexibility in the form of a stretchscore.
[0007] In another embodiment, the pulling force was impacted by an unexpected factor. The inventors have discovered that, in addition to passive resistance to stretch of the muscle-sinew combination, the weight of the extremity increases the pulling force required to provide acceptable treatment intensity. The extremity weight increased the pulling force up ranging from about 5-50 pounds force, depending on how parallel the extremity was with the support surface, and led the inventors to seek methods to reduce the pulling force caused by extremity weight. Increased pulling force requires users to have significant grip strength to impart a reliable and repeatable passive stretch and maintain optimum flexibility. The pulling force required to overcome the weight of the extremity was substantially increased as the extremity was more parallel to the support surface. As the extremity was brought into a perpendicular orientation to the support surface the pulling force needed to overcome the weight force reduced to zero.
[0008] The stretchscore may be determined for lower extremities encompassing all tissue emanating from the lower back and terminating at the phalanges. The stretchscore may also be determined for upper extremities encompassing all tissue emanating from the scapula and terminating at the phalanges. In one context, a stretchscore extremity flexibility number is displayed to the user within a range of possible scores up to and including a maximum.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 depicts prior art showing a medical professional assisting a patient to treat muscle tissue using an assisted straight leg stretch. The patient is using an inelastic adjustable strap placed on the foot and the physical therapist provides overpressure and feedback to maintain knee extension while assisting with hip flexion.
[0010] FIG. 2 depicts prior art in product called Acuflex I modified sit and reach device by Novel Products for evaluating lumber and hamstring flexibility. The Acuflex I does not provide a means for tissue treatment.
[0011] FIG. 3 depicts one embodiment of the present invention, a handheld tissue stretching device that displays an extremity flexibility number to the user when the extremity support is engaged with the users extremity.
[0012] FIG. 4 depicts one embodiment of the present invention, a retractor is used to remove the slack 21 in the pliable, inelastic link 4 when the extremity support 3 is pulled toward the handheld tissue stretching device 1 . The retractor prevents the extremity support 3 from extending 20 away from the handheld tissue stretching device 1 when providing treatment.
[0013] FIG. 5 depicts one embodiment of the present invention. The user is treating tissue by pulling the lower extremity from a first position 10 to a second position 17 to impart a passive stretch on the posterior lower extremity tissue. The handheld stretching device 1 displays an extremity flexibility number 2 to the user in both positions.
DETAILED DESCRIPTION OF THE INVENTION
[0014] FIG. 1 shows the prior art practice of a medical professional treating treating extremity tissue. The user is performing a passive stretch on the posterior lower extremity by holding a strap that is releasably engaged with the extremity by wrapping the strap around the metatarsal pad of the foot. FIG. 2 shows a device that a user may place his feet on and push a slidable indicator along a track to provide the user with a indication of the user's lumbar and hamstring flexibility. The device weighs approximately 15 pounds and is bulky. The device does not provide a means for treatment. An apparatus described in the Burek patent shows a large stationary device for stretching and evaluating tissue using several measures.
[0015] The known portable tissue stretching devices do not properly allow the user to control the treatment intensity because of the need to reposition when increasing stretch intensity, and leave the user wondering whether or not he has stretched properly; known portable flexibility evaluation devices are bulky and most do not provide a means for passively stretching muscle-sinew tissue. Changes in compliance of the muscle-sinew tissue over time can demand different treatment regimens and confuse individuals; pain is often the evaluation method individuals use to determine their extremity flexibility treatment. A self flexibility evaluation is complex because of tightness of specific muscle-sinew combinations, co-morbidities, and the time since last stretch. An apparatus described in the Fluegge patent incorporates a timer that indicates elapsed time for a given stretch. However, elapsed time does not provide an evaluation of the extremity flexibility. Combining an extremity flexibility evaluation, in the form of an extremity flexibility number 2 , with a handheld tissue stretching device provides numerous benefits such as minimizing trips to the physical therapy clinic, eliminating pain as feedback for flexibility evaluation, decreasing the risk of activity-based injuries, increasing muscle-sinew tissue compliance, and optimizing tissue treatment intensity, duration and frequency to achieve desired extremity flexibility. Individuals now have the option to independently and reliably evaluate and improve their flexibility before engaging in activities such as walking, running, sports or work activities.
[0016] In accordance with the invention, FIG. 3 depicts one embodiment of the invention, a handheld tissue stretching device 1 that provides an extremity flexibility number 2 that an individual may use for both evaluating and treating extremity flexibility without involving another person. This device has an extremity support 3 that may be releasably engaged to the user's extremity for evaluation and treatment. The extremity support 3 is connected to the handheld tissue stretching device 1 via a pliable, inelastic link 4 . A retractor 5 pulls the pliable inelastic link 4 and extremity support 3 toward the handheld tissue stretching device 1 . A release mechanism 6 is used to disengage the retractor and allow the user to extend the extremity support 3 away from handheld tissue stretching device 1 . This device 1 enables users to evaluate and treat the flexibility of their extremity tissue as needed, minimizing physical therapist intervention to prescribe a treatment regimen. Similar to a scale used to measure an individual's weight, the extremity flexibility number 2 provides an immediate evaluation of a user's extremity flexibility. Until now, patients have depended upon someone else to determine their flexibility values and issue a flexibility treatment regimen to be done in accordance with this evaluation. The present inventors, however, have recognized that combining a handheld tissue stretching device 1 with an extremity flexibility evaluation, in the form of a display 7 capable of showing an extremity flexibility number 2 , will provide users with a simple indicator of extremity flexibility. A communication means 8 may be provided to share the stretchscore with an electronic device.
[0017] FIG. 4 shows one embodiment of a retractor. The pliable, inelastic link 4 may be pulled toward the handheld tissue stretching device 21 . A release mechanism 6 when engaged with the retractor gear 23 prevents the pliable, inelastic link 4 from extending away from the handheld tissue stretching device 20 . The release mechanism 6 , when disengaged with the retractor gear 23 allows the pliable inelastic link 4 to be extended 20 away from the handheld tissue stretching device 1 .
[0018] FIG. 5 shows a particular method employing one embodiment of the invention, a user stretching the posterior lower extremity. The user holds the handheld tissue stretching device 1 in his hands and engages the extremity support 3 on the metatarsal foot pad in a relaxed position 10 , the user then increases the intensity of the stretch actively raising his extremity and simultaneously pulling on the handheld tissue stretching device 1 the retractor 5 pulls the extremity support 3 toward the handheld stretching device 1 and removes the occurring slack in the pliable, inelastic link 4 as the tissue being treated is lengthened. The plantar fascia tissue 11 , the achilles tendon 12 , the calf musculature 13 , the popliteal fossa 14 , the hamstring muscle group 15 , and the lower back muscles and sinew 16 begin to lengthen as the user pulls the extremity to the second position 17 . The user then reads the extremity flexibility number 2 in the passive stretching position 17 . A shorter distance between the extremity support 3 and the handheld tissue stretching device 1 corresponds directly to lengthening the tissue of the posterior lower extremity: plantar fascia tissue 11 , the achilles tendon 12 , the calf musculature 13 , the popliteal fossa 14 , the hamstring muscle group 15 , and the lower back 16 . An extremity flexibility number 2 is displayed to the user any time the extremity is engaged with the extremity support 3 ; the user may adjust treatment based on the extremity flexibility number 2 . The user may disengage the release mechanism 6 from the retractor gear 23 to extend 20 the extremity support 3 away from the handheld tissue stretching device 1 and allow the user to lower the extremity to the support surface.
[0019] The stretchscore extremity flexibility number 2 can be obtained in numerous ways. One embodiment for determining the stretchscore measures the distance between the handheld tissue stretching device 1 and user's extremity when the extremity is engaged with an extremity support 3 . A pliable, inelastic link 4 is used to connect the extremity support 3 to the handheld tissue stretching device 1 . The handheld tissue stretching device 1 has a retractor 5 that retracts 21 the pliable, inelastic link 4 as the extremity support 3 moves toward the handheld tissue stretching device 1 . Minimizing this distance enables users to eliminate continuous and variable hand re-positioning on the handheld tissue stretching device 1 in order to change the intensity of the flexibility treatment. This “distance matching” between the handheld stretching device 1 and the extremity support 3 provides a reliable, repeatable, and independent evaluation of extremity tissue flexibility in the form of an extremity flexibility number 2 . The concept of using distance matching in a handheld tissue treatment device is an invention independent of the present invention and is the subject of a separate application being filed by the present inventor on the same day as this application.
[0020] In another embodiment, pulling force may be used to indicate the extremity flexibility number 2 . Treatment intensity is one of the three elements of a treatment regimen and is related to the amount of pulling force the user imparts on the extremity. The amount of force needed to stretch an extremity tissue can be measured and is referred to as “passive resistance to stretch” or tensile force of the muscle-sinew combination. Decreasing passive resistance to stretch is directly matched to increasing tissue flexibility; this is known as the viscoelastic effect. The present inventors have discovered that the passive resistance to stretch of the muscle-sinew tissue combined with the weight of the extremity equals the pulling force between the extremity support 3 and the handheld tissue flexibility device 1 . During most treatment regimens, the weight of the extremity adds a substantial opposing force that must be overcome by the pulling force; the added pulling force make it difficult for the user to maintain adequate pulling force and increases variability of the stretch intensity. The combination of the weight of the extremity and the passive resistance to stretch has been measured to be an excellent predictor of the extremity flexibility number 2 .
[0021] In another embodiment of the invention, the pulling force and the distance between the handheld tissue stretching device 1 and the extremity support 3 were combined to compute an extremity flexibility number 2 . Transforming these two measurements into a single extremity flexibility number 2 provides the user with a individualized evaluation of extremity flexibility. These measurements are taken any time the user holds the handheld tissue stretching device 1 and engages the extremity with the extremity support 3 .
[0022] In a particular embodiment of the invention, the user improves the extremity flexibility number 2 when performing a passive stretch 17 on the lower posterior tissue by bending the contralateral lower extremity. The present inventors have shown immediate improvements in the ease of obtaining a stretchscore extremity flexibility number 2 explained by bending the contralateral extremity. This bending of the contralateral extremity allow the extremity being stretched to become more perpendicular to the support surface. When the ipsilateral extremity becomes more perpendicular to the support surface, the pulling force required between the handheld tissue stretching device 1 and the extremity support 3 is reduced because the downward component of the weight does not have to be overcome by the pulling force. Reducing the pulling force using this method enables users to maintain stretch intensity and requires less upper body and hand strength. A flexibility method requiring less grip strength is desirable for persons with weak grip or weak upper body strength.
[0023] The extremity flexibility number 2 may be determined for lower extremities encompassing all tissue emanating from the lower back and terminating at the phalanges. The extremity flexibility number 2 may also be determined for upper extremities encompassing all tissue emanating from the scapula and terminating at the phalanges. In one context, an extremity flexibility number 2 is displayed to the user within a range of possible scores up to and including a maximum extremity flexibility number 2 .
[0024] In a particular embodiment, the extremity flexibility number 2 may be communicated to an electronic network or device using a communication means 8 .
[0025] Other measurements may include one or a combination of angle, or moment between handheld extremity flexibility treatment device 1 and extremity support 3 .
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A handheld tissue stretching device combined with an extremity flexibility number, stretchscore, enables users to independently evaluate and treat the flexibility of their extremity tissue minimizing physical therapist intervention to evaluate and treat tissue. The distance between handheld stretching devices and the extremity supports changes with a high degree of variability during home treatments; whereas, medical professionals monitor stretch intensity visually and manually. Patients performing home-based stretches impart variable intensity that leads to inconsistent tissue treatment resulting in increased tissue stiffness. The present inventors have discovered when the slack is automatically retracted, the distance between the users hands and the extremity support is continuously proportional to the flexibility of the extremity. This “distance matching” between the handheld stretching device and the extremity support provides a reliable, repeatable, and independent evaluation of extremity flexibility by directly relating this change in distance to the user's flexibility.
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CROSS-REFERENCE
The invention disclosed and claimed herein is related to the invention disclosed and claimed in application Serial No. (YO997-080; Thin Film Transistors Fabricated on Plastic Substrates) which was filed on the same date as this application and is assigned to the same assignee as the instant invention.
FIELD OF INVENTION
Generally, this invention relates to thin film transistors especially as used in large area electronics such as information displays and light sensitive arrays for imaging. More particularly, this invention relates to thin film transistors fabricated on plastic substrates, in part by the novel low temperature processes of the invention, thus providing displays that are flexible, lighter in weight and more impact resistant than displays fabricated on traditional glass substrates.
BACKGROUND OF THE INVENTION
Thin film transistors (TFTs) are used in many applications of large area electronics such as information displays and light sensitive arrays for imaging. In displays and imaging arrays, the TFT is used as a switch. The most common application is the active matrix liquid crystal display (AMLCD) which is the preferred display in laptop computers. In such a display, an array of display elements may be interconnected together with TFTs via horizontal and vertical bus bars. For example, the gates of one row of the plurality of TFTs in such displays are connected to a horizontal bus bar while the sources are connected to the vertical bus bars. When a voltage is applied to a predetermined horizontal bus bar and a predetermined vertical bus bar, the gate source and drain which form a particular TFT are energized. In the case of a liquid crystal display, that part of the liquid crystal which corresponds to the energized transistor becomes transparent and light from a source in back of the display is permitted to pass through.
More particularly, in an active matrix display, the TFT switches current on and off. When on, current flows to charge a capacitor associated with an individual pixel of the display to a desired voltage. When off, the capacitor is isolated and the selected charge remains until the next time the pixel is addressed. The voltage level determines the amount of light that is transmitted through the liquid crystal associated with the pixel (i.e., determines the grey level). In light imaging arrays (sensors), the TFT also switches current on and off. When off, charge is built up on a capacitor from a light sensitive diode (more light, more charge). When the TFT is on, the built-up charge is read out to the addressing circuit. The amount of the charge determines the intensity (i.e., grey level). In a different design of imaging array, the TFT is used to address a photosensitive resistor. Chemical sensors based on TFT's have also been described.
Two common TFT structures are shown in FIG. 1 . Referring to FIG. 1A, TFT 10 has the “etch stopper” structure and is made on glass plate 12 . Gate metal 14 applies the gate voltage across gate dielectric 20 . Current flows in channel layer 22 (amorphous or polycrystalline silicon) between source electrode 16 and drain electrode 18 through contact layers 26 . Passivating insulator 24 isolates source 16 and drain 18 and prevents atmospheric degradation.
In FIG. 1B, TFT 30 has the “back channel cut” structure and is made on glass plate 32 . Gate metal 34 applies the gate voltage across gate dielectric 40 . Current flows in channel layer 42 (amorphous or polycrystalline silicon) between source electrode 36 and drain electrode 38 through contact layers 46 . Passivating insulator 44 isolates source 36 and drain 38 and prevents atmospheric degradation.
Heretofore, the displays and photosensors described above have been fabricated on glass substrates and processing temperatures between about 250-400° C. are required. For example, SiNitride layers 20 , 24 , 40 and 44 and a-Si:H layers 22 , 42 are typically deposited by plasma enhanced chemical vapor deposition (PE CVD) and the deposition temperature typically exceeds 250° C. during the PE CVD steps. Hence, only flat information systems that are relatively heavy and fragile have been possible. It would be beneficial if displays could be made lighter in weight, impact (shatter) resistant, and flexible. Curved displays would allow the user to experience a “virtual reality” environment without wearing a display device on the user's head, while curved photosensors would allow detection of a digital image from many directions at one time without moving the sensor array. Impact resistant and light weight displays are key enabling devices for truly portable information products such as laptop computers and personal navigation systems.
Larger and larger glass sheets are being introduced in the manufacture of active matrix liquid crystal displays (AMLCDs) in order to reduce the cost per display by making several displays at one time. The cost of manufacturing AMLCDs would be reduced significantly if thin plastic substrates and continuous roll-to-roll manufacturing methods could be used.
Fabrication of a TFT on a plastic substrate requires solutions to the following problems. Commercially available transparent plastics are dissolved, softened or attacked by many of the standard chemicals used to fabricate semiconductor devices. Thus, the plastic substrate must be made resistant to strong acids (including HF), bases, and hydrocarbon solvents. Inexpensive clear plastics soften or decompose at the standard processing temperatures for TFT fabrication which are typically between about 250-350° C. Since all plastics have a coefficient of thermal expansion (CTE) typically 10 times that of glass, multilayer TFT structures built on plastic are prone to delamination at standard processing temperatures due to thermal expansion of the substrate.
Solutions to those problems have not heretofore been advanced. The present invention provides solutions to the above problems and discloses three exemplary TFT structures on plastic substrates.
SUMMARY OF THE INVENTION
A thin film transistor is described incorporating a gate electrode, a gate insulating layer, a semiconducting channel layer deposited on top of the gate insulating layer, an insulating encapsulation layer positioned on the channel layer, a source electrode, a drain electrode and a contact layer beneath each of the source and drain electrodes and in contact with at least the channel layer, all of which are situated on a plastic substrate. By enabling the use of plastics having low glass transition temperatures as substrates, the thin film transistors may be used in large area electronics such as information displays and light sensitive arrays for imaging which are flexible, lighter in weight and more impact resistant than displays fabricated on traditional glass substrates. The thin film transistors are useful in active matrix liquid crystal displays where the plastic substrates are transparent in the visible spectrum.
Enablement of the use of such plastics is by way of the use of polymeric encapsulation films to coat the surfaces of the plastic substrates prior to subsequent processing and the use of novel processes for the deposition of thin film transistor structures.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other advantages of this invention will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:
FIG. 1A shows an “etch-stopper” TFT of the prior art in cross-section.
FIG. 1B shows a “back channel cut” TFT of the prior art in cross-section.
FIG. 2 shows an “etch-stopper” TFT of the invention in cross-section.
FIG. 3 shows a “back channel cut” TFT of the invention in cross-section.
FIG. 4 shows in cross-section an inverted, staggered “etch stopper” TFT of the invention having conducting polymer electrodes.
FIG. 5 is a graph of current versus voltage for an aluminum gate capacitor of area 0.053 cm 2 with a 2,670 Angstrom thick SiNitride layer.
FIG. 6 is a graph of the conductivity ratio (light/dark) of an a-Si:H layer plotted versus the H 2 /SiH 4 ratio in the PE CVD reactor.
FIG. 7A is a graph of drain current (I D ) versus drain-source voltage (V DS ) for three values of gate voltage for a TFT according to FIG. 2 .
FIG. 7B is a graph of log drain current (I D ) versus gate voltage (V G ) for drain-source voltage (V DS ) equal to 1 volt (curve a) and 10 volts (curve b) for a TFT according to FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
By means of the present invention, it is now possible to fabricate TFT structures on plastic substrates. FIG. 2 shows an inverted, staggered “etch-stopper” TFT structure 50 fabricated on plastic substrate 52 . Protecting the plastic is an amorphous encapsulation film 54 , which covers the top, bottom and edges of substrate 52 . Suitable plastics for 52 are polycarbonates such as LEXAN® available from GE Plastics and cyclic olefin copolymers such as TOPAS™ available from Hoechst Celanese or Zeonex® available from BF Goodrich. Such clear plastics (i.e., having ≧90% transmission throughout the visible light spectrum) have glass transition temperatures (T g ) between about 120 and 200° C. For those materials which also have a melting temperature (e.g., semi-crystalline plastics), the melting temperature is higher than the glass transition temperature. In any case, these temperatures are low compared to the glass transition temperature of ordinary borosilicate window glass (T g ≈600-700° C.) and enablement of the use of plastics having low glass transition temperatures is an innovation of the instant invention. Opaque plastics, which may have glass transition temperatures above about 200° C. are also enabled by the invention. These, too, are characterized as having a low glass transition temperature especially compared to borosilicate window glass, for example.
Encapsulation film 54 must possess all of the following characteristics. It must be electrically insulating, transparent in the visible spectrum (for AMLCDs), be resistant to attack by processing chemicals, including strong acids, strong bases, and solvents, be resistant to scratching, be smooth and pin-hole free and adhere well to the plastic substrate during thermal cycling to about 125-150° C. It has been found that thermally cured SHC 1200 Hard Coat and ultraviolet cured UVHC 8558 Hard Coat available from GE Silicones and Vitrinite™, available from Metroline Industries, Inc. possess the above-mentioned characteristics. It has also been found that use of GE Silicones SHP 401 primer to prepare the substrate before application of the Hard Coat provides best adhesion of the GE Silicones Hard Coat. Encapsulation film 54 may be applied by dipping or spin coating (GE Silicones Hard Coats) or by vacuum coating (Vitrinite).
In FIG. 2, gate metal layer 56 (gate electrode) is deposited and patterned. Acceptable metals for forming the gate electrode are Cr, Ta, Mo, W, and Cu and alloys thereof; Cr is generally presently preferred. Layered structures (tri-layers) of Cr/M/Cr, where M is a metal selected from the foregoing list are also useable; aluminum clad with chromium (Cr/Al/Cr) is generally presently preferred. Tri-layers of Ti/M/Ti are also useable. Substrate 52 with encapsulation film 54 containing gate metal 56 is placed in a reactor and layers 58 , 60 and 62 are deposited in sequence. Layer 58 is the gate dielectric (insulating layer), preferably amorphous SiNitride, and is deposited at or above 125° C. by the preferred SiNitride PE CVD process of the invention described below. Layer 60 is a semiconducting channel layer, here hydrogenated amorphous Si (a-Si:H), and is deposited at or above 125° C. by the preferred a-Si:H PE CVD process of the invention described below.
Layer 62 is an insulating encapsulation layer of amorphous SiNitride which may be deposited by the same PE CVD process used to form layer 58 . Layer 62 is then patterned lithographically. Contact layer 64 is then deposited. Contact layer 64 is an n-type semiconductor, preferably a-Si:H doped with phosphorus, and is made by a suitable process such as PE CVD. Alternatively, layer 64 can be a low work function metal such as magnesium or yttrium. Layer 66 , a metal thin film wire such as aluminum, chromium or tantalum is then deposited by evaporation or sputtering. Layers 64 and 66 are then patterned lithographically. A passivation layer (not shown) may be added over the top of device 50 .
A second structure 70 , a back channel cut TFT, is shown in FIG. 3 . Layers 72 , 74 , 76 , 78 , 80 , 84 , and 86 are made of the same materials and by the same processes as layers 52 , 54 , 56 , 58 , 60 , 64 and 66 , respectively, of device 50 discussed above. Layer 82 , an insulating encapsulation layer, is deposited and patterned after layers 84 and 86 are deposited and patterned lithographically to expose layer 86 . A passivation layer (not shown) may be deposited over the top of device 70 .
FIG. 4 shows inverted, staggered “etch-stopper” TFT 90 having conducting polymer electrodes fabricated on clear plastic substrate 92 . Protecting the plastic is an amorphous encapsulation film 94 , which covers the top and bottom surfaces and the sides.
In FIG. 4, gate layer 96 (gate electrode) is a conducting polymer. Examples of suitable conducting polymer gate materials for layer 96 are polyaniline, polyacetylene and polyphenylenevinylene. Polymer gate 96 is protected during processing by layer 98 . Preferred materials for this protective layer are doped N-type a-Si:H having a resistivity of not more than about 1000 ohm-cm, preferably about 10-100 ohm-cm, or a thin chromium layer. Layer 98 must be thin, conducting and mechanically robust. Substrate 92 plus layers 94 , 96 , 98 is placed in a suitable reactor and layers 100 , 102 , 104 are deposited in sequence. Layer 100 is the gate dielectric, preferably amorphous SiNitride which is deposited at about 125° C. by the same process as that used to make layer 58 . Layer 102 is a-Si:H channel layer which is deposited at about 125° C. by the same process used to form layer 60 .
Layer 104 is an insulating encapsulation layer and may be deposited by the same PE CVD process used to form layer 100 . Layer 104 is then patterned lithographically. Contact layer 106 is then deposited. Layer 106 is an n-type semiconductor, preferably a-Si:H doped with phosphorus, and is made by a suitable deposition process such as PE CVD. Alternatively, layer 106 can be a low work function metal such as magnesium or yttrium. Layer 108 , a conducting polymer, is then deposited by a spin-on or dip coating process followed by evaporation of the solvent in the polymer. Layers 106 and 108 are then patterned lithographically.
The dielectric layers in FIGS. 2, 3 , 4 are numbered 58 and 62 , 78 and 82 , and 100 and 104 , respectively. These films must be insulating and must be characterized by leakage current density of less than about 1×10 −8 Amps/cm 2 and breakdown electric field of greater than 5 MV/cm. Furthermore, these films must be deposited at process temperatures of less than 150° C., and preferably at about 125° C. or lower. One suitable process is the low temperature SiNitride PE CVD process of the invention described below.
The amorphous Si layers in FIGS. 2, 3 , 4 are numbered 60 , 80 , and 102 , respectively. These films must be semiconducting with mid-gap defect densities of order 10 16 /cm 3 , or less. Furthermore, these films must be deposited at process temperatures of less than 150° C., and preferably at about 125° C. or lower. One suitable process is the special low temperature a-Si:H PE CVD process described below.
A novel plasma enhanced chemical vapor deposition (PE CVD) process to deposit dielectric layers 58 , 62 , 78 , 82 , 100 and 104 is the following SiNitride process. The dielectric may be an amorphous Si, N, H alloy. The preferred process is to place the plastic substrate containing the patterned gate layer in a reactor at a temperature of 125° C. in a gas mixture at a pressure in the range 0.1 to 1 Torr, the optimum pressure being 0.6 Torr. The gas mixture contains helium, nitrogen, ammonia and silane and the total gas flow is between about 500-2000 sccm with the optimum being about 875 sccm. For He/silane the flow ratio is between about 20/1 to 100/1, preferably about 60/1; for nitrogen/silane it is between about 15/1 to 25/1, preferably about 20/1 ; and for ammonia/silane it is between about 1.2/1 to 2/1, preferably about 1.5/1. The preferred RF Power/area is about 0.05 Watts/cm 2 , and may be in the range 0.03 to 0.1 Watts/cm 2 . Aluminum gate capacitor structures (here Al/SiNitride/Al) having a SiNitride dielectric film 2,670 Angstroms thick were made using this process. These capacitors exhibited a breakdown field of 6.4 MV/cm, and leakage current at 1.1 MV/cm field of 6×10 −9 Amps/cm 2 . FIG. 5 shows the leakage current, curve 120 , and the current breakdown, curve 122 , at 6.4 MV/cm for these capacitors. These data show that this novel low temperature PE CVD process is capable of depositing SiNitride having dielectric characteristics equivalent to those made by higher temperature PE CVD processes utilizing different gas mixtures and other process parameters.
A novel PE CVD process to deposit the a-Si:H channel layers 60 , 80 and 102 is as follows. The preferred process is to place the plastic substrate in a reactor at a temperature of 125° C. and in a gas mixture at a pressure in the range 0.5 to 1.5 Torr, the optimum pressure being 1.0 Torr. The gas mixture contains He, hydrogen, and silane and the total gas flow is in the range of about 300-500 sccm, preferably about 350 sccm. For He/silane, the flow ratio is between about 10/1 to 50/1, preferably 20/1 and for hydrogen/silane it is between about 3/1 to 8/1, preferably 7/1,. The preferred RF Power/area is about 0.03 Watts/cm 2 and may be in the range 0.02 to 0.05 Watts/cm 2 . The resulting a-Si:H layers exhibit an optical gap of 1.85 eV, a refractive index of 3.86 and a hydrogen content of 20% with only monohydride bonding as characterized by infrared absorption spectroscopy and exhibit a ratio of photo/dark conductivity consistently >100,000. Both of these measurements are unchanged with several months time. FIG. 6 shows the ratio of photo/dark conductivity plotted vs. hydrogen/silane ratio. The photoconductivity was measured with a light fluence of about 0.1 Watts/cm 2 . The dark conductivity was measured inside a light tight metal box. The data points labelled 130 identify the preferred Hydrogen/Silane ratio. The dashed line labelled 132 shows the resulting ratio of photo/dark conductivity with no He used (i.e., only hydrogen). The data points labelled 134 illustrate the resulting ratio of photo/dark conductivity with no hydrogen (only He) used. These data show that this novel low temperature PE CVD process is capable of depositing a-Si:H layers having semiconducting characteristics equivalent to those made by higher temperature PE CVD processes utilizing different gas mixtures and other process parameters.
In describing the foregoing novel low temperature PE CVD processes, it should be understood that the term substrate means a plastic substrate such as substrate 52 coated with polymeric encapsulation film 54 , however, the substrate need not necessarily be limited to a plastic. It will also be understood that the processes may be applied to other structures, such as one where gate electrode 56 and gate dielectric 58 have previously been formed on substrate 52 coated with film 52 . The PE CVD process does not form a part of this invention per se; that is the novel processes can be carried out in conventional PE CVD process equipment such as is described by Matsuda and Hata in Chapter 2 (Deposition Process and Growth Mechanism) of Glow-Discharge Hydrogenated Amorphous Silicon (K. Tanaka, ed.), Kluwer Academic Publishers which is incorporated herein by reference.
The novel low temperature PE CVD process described above can also be used to make other devices on plastic or other substrates. For example, active matrix displays can use a thin film metal/insulator/metal diode at each pixel instead of a TFT. The SiNitride PE CVD process of the invention can be used to make the insulator layer. In one embodiment of a light sensor array, an electrode/a-Si:H/electrode photosensitive resistor is used. The a-Si:H PE CVD process of the invention can be used to make the a-Si:H layer.
An alternative process for deposition of dielectric layers 58 , 62 , 78 , 82 , 100 and 104 is is Reactive Magnetron Sputtering using a Si target and suitable pressures of argon, nitrogen and hydrogen at about 125° C. as described by McCormick et al. in “An Amorphous Silicon Thin Film Transistor Fabricated at 125° C. by DC Reactive Magnetron Sputtering”, Appl. Phys. Lett. 70(2), Jan. 13, 1997, pp. 226-227, which is incorporated herein by reference. An alternative process for deposition of amorphous Si layers 60 , 80 , and 102 is Reactive Magnetron Sputtering as described in the aforementioned Appl. Phys. Lett. technical article.
The invention is further illustrated by means of the following examples which are intended to be exemplary and not limiting of the invention.
EXAMPLE 1
Lexan polycarbonate (0.75 mm thick) from GE Plastics was coated at Metroline Company with the Vitrinite (™) coating. The coated substrates were cut into 5 cm×5 cm squares, baked at 120° C. in an oven for 1 hour, placed in a plasma reactor and exposed to an Argon plasma for 20 minutes at a pressure of 0.4 Torr and 0.36 W/Cm 2 power density, in order to improve adhesion to the Vitrinite coating. The coated substrates were then placed in a vacuum chamber and gate metal 56 was deposited by evaporation in 3 successive layers. In this example (as also in the next example), layer 56 was not patterned as was the case for the device of FIG. 2 where it appears as a metal line of width similar to the TFT size, but was a “blanket” layer over the entire substrate. This does not affect the electrical data, but makes the processing simpler. Next, a 200 Angstrom thick layer of chromium (adhesion layer) was deposited. Second, a 600 Angstrom thick layer of aluminum (conductivity layer) was deposited. Finally, a 200 Angstrom thick layer of chromium (adhesion layer) was deposited.
The substrates containing the gate metal were placed in a plasma chemical vapor deposition reactor, heated to 125° C., and layers 58 , 60 and 62 were deposited in sequence without exposure to air. Gate dielectric 58 was deposited at a pressure of 0.6 Torr, for 25 minutes using an RF power density of 0.036 W/cm 2 , and 13.6 MHz frequency, resulting in a film approximately 3,000 Angstroms thick. The gases and flow rates were silane (10 sccm), ammonia (15 sccm), nitrogen (250 sccm) and helium (600 sccm). The reactor was pumped out, and the a-Si:H layer 60 was deposited at a pressure of 1.0 torr for 15 minutes using 0.026 W/cm 2 power density, resulting in a film approximately 750 Angstroms thick. The gases and flow rates were silane (20 sccm), hydrogen (140 sccm) and helium (200 sccm). FIG. 6 shows the optimization to select the best H 2 /Silane ratio, 7/1, to make the a-Si:H layer. The reactor was pumped out and encapsulation (etch stop) SiNitride layer 62 was deposited for 33 minutes using the same process described above for layer 58 , resulting in a film approximately4,000 Angstroms thick. The samples were cooled to room temperature in the reactor and removed. A first lithography step was performed to pattern the TFT source and drain vias. The substrate was spin coated with photoresist (Shipley 1813) by spinning at 3,000 rpm for 30 seconds. The photoresist (PR) was then cured at 90° C. in an oven for 20 minutes. The PR was patterned using a Karl Suss MJB-3 Aligner. The exposure time was 20 seconds and the light fluence was 9.5 mW/cm 2 . The PR was developed for 60 seconds in Shipley MFP-321 developer, rinsed in deionized water (DW) and fully cured at 120° C. in an oven for 20 minutes. The source and drain vias were next etched in 1% Hydrofluoric acid (HF) for 60 seconds and the substrates were next rinsed in DW and dried. The PR was removed in an oxygen plasma ashing tool for 9 minutes using 0.1 Watt and 10 sccm oxygen flow.
Prior to deposition of the metal source and drain electrodes, the exposed surfaces of layer 60 were cleaned by placing the substrates in 0.1 % HF for 20 seconds. The surfaces were blown dry with dry nitrogen, and immediately placed in a vacuum chamber. Metal source and drain layers 64 and 66 were deposited by evaporation. First, contact layer 64 (1,000 Angstroms of magnesium) was deposited then electrode layer 66 (1,500 Angstroms of aluminum) was deposited.
A second lithography step was performed to pattern the TFT source and drain electrodes, using the same procedure as in the first lithography step. Metal layers 64 and 66 were etched in Aluminum Etchant A from Transene Co. (Rowley, Mass.) for 45 seconds at 35° C. The PR was removed in an oxygen plasma for 9 minutes using 100 Watts and 10 sccm oxygen flow. The substrates were then rinsed for 30 minutes in flowing DW, blown dry, and baked in an oven at 120° C. for 30 minutes. The finished TFT's were then stored in a dry nitrogen ambient.
The electrical characteristics were measured using an HP 4145A Parameter Analyzer with the substrates on a probe station inside a metal box to exclude light. Typical characteristics are shown in FIGS. 7A and 7B for a TFT with width/length ratio of 7. FIG. 7A is a plot of the drain current (I D ) versus drain-source voltage (V DS ) for gate voltages of 15, 20 and 25 Volts (curves (a), (b) and (c), respectively). FIG. 7B is a plot of the drain current (I D ) on a logarithmic scale versus gate voltage (V G ) for V DS of 1 and 10 Volts. From these data, the TFT's of the invention on plastic are seen to exhibit typical TFT characteristics and a field effect mobility of 0.2 to 0.3 cm 2 /V s is estimated.
EXAMPLE 2
Lexan polycarbonate (0.75 mm thick) from GE Plastics was cut into 5 cm×5 cm squares, washed with deionized water (DW) and soap and then rinsed in running DW. The substrates were further rinsed ultrasonically in DW 3 times, rinsed in isopropyl alcohol, and baked at 120° C. in an oven for 1 hour. The clean substrates were dipped in LHP100 PM Primer (adhesion promoter) from GE Silicones, dried in air for 30 minutes, and baked at 120° C. for 1 hour. The substrates were then dipped in SHC1200 Hardcoat from GE Silicones, dried overnight in air and baked at 120° C. for 1 hour.
The coated substrates were then placed in a vacuum chamber and gate metal 56 was deposited by evaporation. First, 200 Angstroms of chromium (adhesion layer) was deposited. Second, 600 Angstroms of aluminum (for conductivity) was deposited. Finally, 200 Angstroms of chromium (adhesion layer) was deposited.
The substrates containing the gate metal were placed in a plasma chemical vapor deposition reactor, heated to 125° C., and layers 58 , 60 and 62 were deposited in sequence without exposure to air. Gate dielectric 58 was deposited at a pressure of 0.6 torr, for 25 minutes using an RF power density of 0.036 W/cm 2 , and 13.6 MHz frequency, resulting in a film approximately 3,000 Angstroms thick. The gases and flow rates were silane (10 sccm), ammonia (15 sccm), nitrogen (250 sccm) and helium (600 sccm).
The reactor was pumped out and the a-Si:H layer 60 was deposited at a pressure of 1.0 Torr, for 15 minutes using 0.026 W/cm 2 power density, resulting in a film approximately 750 Angstroms thick. The gases and flow rates were silane (20 sccm), hydrogen (140 sccm) and helium (200 sccm).
FIG. 6 shows the optimization to select the best H 2 /Silane ratio, 7/1, to make the a-Si:H layer. The reactor was pumped out, and the encapsulation (etch stop) SiNitride layer 62 was deposited for 33 minutes using the same process described above for layer 58 , resulting in a film approximately4,000 Angstroms thick. The samples were then cooled to room temperature in the reactor and removed.
A first lithography step was performed to pattern the TFT source and drain vias. The substrate was spin coated with photoresist (Shipley 1813) by spinning at 3,000 rpm for 30 seconds, and the photoresist (PR) was then cured at 90° C. in an oven for 20 minutes. The PR was patterned using a Karl Suss MJB-3 Aligner. The exposure time was 20 seconds and the light fluence was 9.5 mW/cm 2 . The PR was developed for 60 seconds in Shipley MFP-321 developer, rinsed in DW, and fully cured at 120° C. in an oven for 20 minutes. Source and drain vias were etched in 1% Hydrofluoric acid (HF) for 60 seconds and the substrates were rinsed in DW and dried. The PR was removed in an oxygen plasma ashing tool for 9 minutes using 0.1 Watt and 10 sccm Oxygen flow.
Prior to deposition of the metal source and drain electrodes, the substrates were dipped in 0.1 % HF for 20 seconds, blown dry with dry nitrogen, and immediately placed in a vacuum chamber. Metal source and drain layers 64 and 66 are were deposited by evaporation. First, contact layer 64 (1,000 Angstroms of magnesium) was deposited then electrode layer 66 (1,500 Angstroms of aluminum) was deposited.
A second lithography step was performed to pattern the TFT source and drain electrodes using the same procedure as in the first lithography step. Metal layers 64 and 66 were etched in aluminum Etchant A from Transene Co. (Rowley, Mass.) for 45 seconds at 35° C. The PR was removed in an oxygen plasma for 9 minutes using 100 Watts and 10 sccm oxygen flow. The substrates were then rinsed for 30 minutes in flowing DW, blown dry and baked in an oven at 120° C. for 30 minutes. The finished TFTs were stored in a dry nitrogen ambient. The electrical characteristics were measured as described above in the first example. The TFT characteristics were the same as those of FIG. 7A and 7B in the first example.
While this invention has been described in terms of preferred embodiments, it is apparent that one skilled in the art could adopt other forms. For example, other materials could be used or developed as substitutes for those noted, and different assembly techniques and procedures could be employed. Accordingly, the scope of my invention is to be limited only by the following claims.
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A thin film transistor is described incorporating a gate electrode, a gate insulating layer, a semiconducting channel layer deposited on top of the gate insulating layer, an insulating encapsulation layer positioned on the channel layer, a source electrode, a drain electrode and a contact layer beneath each of the source and drain electrodes and in contact with at least the channel layer, all of which are situated on a plastic substrate. By enabling the use of plastics having low glass transition temperatures as substrates, the thin film transistors may be used in large area electronics such as information displays and light sensitive arrays for imaging which are flexible, lighter in weight and more impact resistant than displays fabricated on traditional glass substrates. The thin film transistors are useful in active matrix liquid crystal displays where the plastic substrates are transparent in the visible spectrum. Enablement of the use of such plastics is by way of the use of polymeric encapsulation films to coat the surfaces of the plastic substrates prior to subsequent processing and the use of novel low temperature processes for the deposition of thin film transistor structures.
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CROSS REFERENCE TO RELATED APPLICATIONS
This applications refers to and claims the priority of U.S. Provisional Patent Application Ser. No. 60/111,860 filed Dec. 11, 1998 and entitled “AIRCRAFT ICING DETECTION SYSTEM” the entire contents of which are incorporated herein by reference.
STATEMENT OF GOVERNMENT RIGHTS
This invention was made with Government support under a Small Business Innovative Research (SBIR) contract number N68335-96-0228 awarded by the U.S. Navy. The Government has certain rights in the invention.
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to a method of detecting icing and icing growth rates on an aircraft through measurements of the aircraft's flight performance.
2. Description of Related Art
A major difficulty with multi-mode aircraft is that icing sensors are difficult to effectively and safely position. For example, the Bell/Agusta 609 and the Osprey V-22 aircraft will operate in both a hover mode, like a conventional helicopter, and in a fixed wing mode, like most normal aircraft. Unfortunately, this characteristic can make it difficult to know where to position icing sensors since the instruments will be subjected to totally different dynamic conditions depending upon whether the aircraft is hovering, flying fixed wing, or in some mode in between, as might occur during take off. In order to cope with this dilemma an effort was made to determine if useful information could be obtained from the general performance of the aircraft under icing conditions to determine, or at least supplement, traditional icing sensor output to anticipate icing conditions and take appropriate corrective action before serious control and lift problems occur.
Some aspects of the present invention are known in the prior art. Previous investigations by Leigh Instruments for the U.S. Army were directed towards a system for inferring the rate of ice accretion on a UH-1 rotor, through measurements of torque increases during periods of flight in known icing conditions. (See Macmillan, R., “Advanced Icing Severity Level Indicating System (AISLIS),” USAAVSCOM TR-86-D-7, December 1986.) This system was only partially successful, due to its reliance on significant pilot input for aiding the calculations performed by the device's internal UH-1 performance model (such as providing cargo weight and aircraft drag data), and for its use of relatively simplistic logic in gauging the type of icing present when torque increases were present in flight.
Related system monitoring devices are already part of, for example, the V-22 military aircraft. A similar combination of direct and indirect measurements are currently used in the V-22 Osprey's Central Integrated Checkout (CIC) and Vibration, Structural Life and Engine Diagnostic (VSLED) systems for maintenance and usage monitoring. (See Augustin, M. and Middleton, G., “A Review of the V-22 Health Monitoring System,” Proc. 45th AHS Annual Forum, Boston, Mass., May 1989). This latter system acts as a terminal on the V-22's 1553 databus and uses aircraft parameters in conjunction with dedicated accelerometers to determine both aircraft flight load spectra and provide data for track and balance maintenance. A key advantage of the system is the elimination of the requirement for a large collection of dedicated and specialized instrumentation to perform this function. Monitoring logic for these systems primarily uses Boolean comparisons between measurements and reference points to determine system faults, plus capability for storage of time histories of out-of-condition data for subsequent post-flight analysis and maintenance activities.
Current state-of-the-art in aircraft icing detection typically incorporates discrete sensors located in strategic positions about the aircraft fuselage or wing structure in order to directly sense the amount of icing growth present at the sensor location. These sensor data may then be used to infer the ice growth at other locations on the aircraft if sufficient test data are available for extrapolation purposes. Such approaches are limited by the availability of aircraft structure to accommodate the given sensor, requirements to transfer power and data signals to each of these possibly remote sensors, and the need to have suitable data for proper interpretation of their associated output measurements.
SUMMARY OF THE INVENTION
The disclosed invention provides a means for indirectly detecting ice accretion through measurement of aircraft performance-related quantities. Since accreted ice can impact both aircraft performance and flight safety, sensing of total aircraft performance degradation on-line would also provide a means of assessing the relative severity of the particular icing event during an actual encounter. A fundamental advantage of this type of approach is that additional devices for measurement of ice accretion may be unnecessary due to the information provided by the available on-board instrumentation. A convenient conceptual model for this methodology is to consider the entire aircraft as the icing probe, such that knowledge of how the aircraft performance degrades in different icing encounters throughout its flight envelope allows the proposed system to sort out the location, type, and quantity of ice being accreted.
The proposed approach for icing detection comprises a methodology used to identify and isolate the location of significant ice accretion on the reference aircraft. Knowledge of how the aircraft performance deteriorates in icing is used to assess the severity and location of the icing event. That knowledge is employed through the use of a dynamic system reference model that can be made to “track” the current flight condition or mode. Incorporation of a model-based estimate of performance thus allows one to borrow from the rich collection of methodologies developed for fault detection in feedback control systems. The approach, described in the detailed disclosure that follow, blends an analytical performance prediction structure with a detection methodology that was originally based upon filtering techniques used to identify inoperative sensors or failed actuators in feedback control systems. This filtering technique, called fault detection filter (FDF) design, has been applied to a variety of aerospace systems and provides a common conceptual framework for incorporating ice detection methods using both direct and indirect sensor suites. (See, Willsky, A. S., “A Survey of Design Methods for Failure Detection in Dynamic Systems,” Automatica, Vol. 12, pp. 601-611, 1976; and also see Patton, R. and Chen, J., “Robust Fault Detection of Jet Engine Sensor System Using Eigenstructure Assignment,” Journal of Guidance, Control, and Dynamics, Vol. 15, No. 6, November-December 1992).
The methodology preferably combines the inputs from traditional discrete icing sensors (if present) with indirect information such as thrust and rotor characteristics in response to torque, and compares that information to an expected model of aircraft performance in a recursive filter. The filter output is fed to threshold checking logic to then generate an output that provides icing information to a cockpit visual display and possibly control signals to the aircraft's anti-icing equipment.
These and other features of the invention will be more fully understood by reference to the following drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic diagram of the icing detection system according to the preferred embodiment of the invention.
FIGS. 2 a and 2 b are a flow diagram representing the steps of the method of the invention shown in FIG. 1 above.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
During the course of this description like numbers will be used to identify like elements according to the different figures that illustrate the invention.
In general, the invention 10 disclosed here comprises an on-board aircraft computer that has access to measurements of aircraft system parameters and can initiate pilot warnings or take appropriate automatic action upon detection of aircraft icing conditions; the embedded software for processing the measurement data to determine that performance measurements are indicative of an icing environment; and the detection algorithms that differentiate between other performance anomalies and those due to icing growth on the airframe and lifting surfaces. The preferred embodiment uses Fault Detection Filters (FDFs) to separate given performance changes from features other than icing growth, and may incorporate sensor data from an on-board aircraft databus as appropriate.
The design and formulation of the fault detection filter (FDF) algorithm is an extension of that described in Patton and Chen (1992). The main feature of the method consists of constructing a state estimator for the dynamic system that selects a feedback gain on the measurement residual to make the overall estimator sensitive to pre-specified types of system failures. Through careful selection of the gain matrix, one may force the measurement residual to remain fixed in a particular direction or a specific plane for a given failure mode. A simple example for a linear time-invariant system from Willsky (1976) serves to illustrate the approach. For a system described in state variable format, with x(t) representing a nx 1 vector of state variables, u(t) an mx 1 vector of control inputs to the system, and A and B representing the perturbations in the state time derivatives (marked by the dot superscript) to state and control changes, one has:
{dot over (x)}(t)=Ax(t)+Bu(t)
with an rx1 vector of measurements y(t) linearly related to the state variable through a matrix C according to:
y(t)=Cx(t)
a detection filter is designed of the form:
{circumflex over ({dot over (x)})}(t)=A{circumflex over (x)}(t)+Dr(t)+Bu(t)
r(t)=y(t)−C{circumflex over (x)}(t)
where the “hatted” quantities represent the current estimates of the state variables, r(t) the measurement residual, and with D chosen to accentuate any failures that may occur in the system. For example, if a bias of magnitude v suddenly appears on the i-th actuator, the system becomes:
{dot over (x)}(t)=Ax(t)+B[u(t)+ve i ], or
{dot over (x)}(t)=Ax(t)+Bu(t)+vb i
where b i represents the i-th column of matrix B. For the case of full state measurement, C=I (the identity matrix), and thus the equation governing the measurement residual becomes:
{dot over (r)}(t)=[A−D]r(t)+vb i
so if D is chosen=[σI+A], then the residual dynamics become:
{dot over (r)}(t)=−σr(t)+vb i , or,
r(t)=exp{−σ(t−t 0 )}r(t 0 )+v[1−exp{−σt}]b i /σ
Thus, after the initial transient dies out, the steady residual maintains a fixed direction aligned with vector b i . Note that its magnitude decreases as the bandwidth of the detection filter increases, thus trading off speed of response with sensitivity to noise in the system.
As applied to icing detection for aircraft, the known icing effects (obtained from test data or engineering predictions) are incorporated as “external” inputs to the system through, as in the above example, the B matrix; performance related measurements are expressed as components in the y vector. Detection logic may then be based upon magnitude checks of the resulting filter residuals, with the direction indicative of the type of icing effect encountered.
Detection filters are a form of recursive filter that couples a dynamic model of a particular process with an analytical model of the sensors used to measure features associated with that process. Differences between the sensor model predictions and the actual sensor outputs, called measurement residuals, are fed back as a weighted sum that is structured to be particularly sensitive to detecting certain pre-postulated system faults. These faults may be in the sensors, such as offsets, scale factor errors, or drifts in output, or in the system itself, such as parametric changes that influence the dynamics of the process being modeled. This formulation allows one to discriminate between a variety of potential variations in the system or sensors, thus providing a means for a complex system to accommodate potential failures and thereby avoid loss of functionality. While the technology associated with detection filter design has tended to be directed toward the monitoring of closed-loop control systems, detection filters offer potential advantages as a paradigm for incorporating a large and varied assortment of sensors for the detection of icing on a complex aircraft, such as the Bell/Agusta 609 tiltrotor and V-22 Osprey. A schematic of the filter structure (elements 18, 22, 26 and 36) may be seen in FIG. 1, showing the feedback correction to the state estimates from the measurement residuals.
Discrimination of various system changes is performed by structuring the filter feedback coefficients to force the filter dynamics to have discrete, identifiable modes of response when a particular parametric variation or sensor “malfunction” occurs. The modes of response may in turn produce output signals whose magnitude indicate the likelihood of a particular event, which would then initiate some action to accommodate the change of behavior and bring the system back to its nominal performance level. Thus, use of detection filters for determining the onset and extent of icing for a complex V/STOL aircraft would only require a reformulation of the dynamics of the “icing process” and its effects on aircraft performance in order to make use of this powerful methodology.
An alternate embodiment for more complicated configurations becomes necessary, if direct icing effects may not be modeled as above (i.e., as a “column” of a B matrix in the above equations), or if full state measurement is not possible. This approach would first involve the computer simulation (or flight testing) of the aircraft flying in an icing environment, with recording of the perturbations in the simulated (or actual) aircraft operational parameters (such as airspeed, altitude, throttle settings, etc.) that occur due to the icing encounter, onto a datafile for post-processing. These recorded data would be used to compute the primary variations of the system states that take place during an icing encounter, and then these dominant variations would be selected to represent “icing modes” of response of the aircraft. Each of possibly several “icing modes” is then isolated and identified as a discrete eigenvector of response of the aircraft. An eigenvalue/eigenvector assignment procedure is then used to determine the feedback gains (matrix D) in the above equations that make the observer sensitive to icing perturbations on the actual aircraft, as outlined below, and presented in the controls literature (See Andry, A., Jr., Shapiro, E., and Chung, J., “Eigenstructure Assignment for Linear Systems,” IEEE Trans. On Aerospace and Electronic Systems, Vol. AES-19, No. 5, September 1983).
Andry, et. al., present an algorithm for computing feedback gains for a control system to provide a desired eigenstructure using output feedback. That is, in the above expressions, a control input u is desired that feeds back the outputs y using a matrix, here called F, such that the closed loop control system is governed by:
{dot over (x)}=Ax+B(Fy)=Ax+BFCx=(A+BFC)x
Note that the explicit time dependence of x, u and y has been dropped from the above equation, and will be assumed implicitly in what follows. For the fault detection problem of interest here, however, we wish to construct an observer for this system, and thus the B matrix in the above control equation would represent a unit matrix. The gain selection problem becomes one of finding the matrix F such that (A+FC) has the desired eigenstructure. One possible difficulty of this direct application of Andry's eigenstructure assignment approach to observer design, however, is that the number of “free” eigenvalue/eigenvector pairs available for specification is limited to the number of measurements in the system model, even though the elements within these limited number of eigenvectors may be matched exactly. While the number of measurements may be considerable for the type of system considered here, namely, an aircraft with an onboard databus that contains many parameters, this limitation may in fact be too burdensome for simpler implementations of data systems or on-board instrumentation on older aircraft. Another key limitation of this design flexibility is the lack of guaranteed stability of the resulting observer, since (n-r) eigenvalues are not available for placement with this approach. Instead, if one considers the “dual” problem of finding the F matrix for a given eigensystem associated with (A T +F T C T ), as suggested by Patton, et. al. (1992), one may attempt to assign a complete set of n eigenvalue/eigenvector pairs. This capability comes with the caveat that the eigenvectors themselves will be restricted to a projection of a “best fit” to the original desired vectors, since the number of “free” coefficients within each eigenvector is limited, again, to the number of measurement of the system. For modeling icing events as “faults” of the system response, as revealed here, either of these two approaches (“direct” or “dual”) may be used, depending upon the number of measurements available to the observer.
The “dual” algorithm for selecting the observer gain matrix F follows, since this provides the designer with the widest range of potential aircraft applications, although it will be appreciated by one skilled in the art that a “direct” algorithm application would possibly suffice for a system having a large number of measurements. Given a desired eigenvector (v i ), which one wishes the observer structure to contain, one then picks a suitable associated eigenvalue (λ i ) that is approximately three times faster (larger) than the dominant eigenvalue of the response mode associated with the icing encounter. For most aircraft, this would be a classical “phugoid” response mode, where the aircraft is primarily influenced by energy tradeoffs between altitude (influenced by flight path angle) and airspeed. These eigenvalue/eigenvector combinations are selected in order to span the full n-dimensional state vector, based upon observations of simulated or actual flight data from an icing encounter. Two types of eigenvectors are selected—those that represent the aircraft response to an icing event, or a particular icing mode (such as proprotor icing, wing icing, or tailplane icing), and other eigenvectors that are orthogonal to these icing mode eigenvectors. This selection aids the discrimination process in determining if an icing event has taken place on the aircraft, by shifting the relative “direction” of the state perturbations to align themselves almost exclusively with these icing mode eigenvectors.
Collecting these eigenvectors in a matrix as:
M=[v 1 v 2 . . . v n ]
one finds its inverse, which are desired to represent the “left eigenvectors” of the “dual” observer system:
A T −C T F T
Let this inverse matrix be given as:
M −1 =[μ 1 μ 2 . . . μ n ]
and let each of the μ i be rearranged by rows where the first r rows (where r is the number of measurements available) represent the dominant, desired values of μ i to be matched in the observer eigenstructure, and the remaining (n-r) rows “arbitrary”, or matched in a least-squared sense: μ i [ l i d i ] , dim ( l i ) = r , dim ( d i ) = n - r
For each associated eigenvalue λ i (note that the eigenvalues are the same for the “direct” and “dual” or transformed system), one computes the nxr matrix:
(λ i I−A T ) −1 C T =L i
and, additionally, a row-reordered version, according to that used on the μ i values: [ L ~ i D i ] = reordered L i
The “achievable” eigenvectors for this “dual” problem are given by:
μ i A =L i ({tilde over (L)} i T {tilde over (L)} i
which represents a least-squares projection of the desired left eigenvectors onto a vector space spanned by the available output space of the mapping imposed by the quantity (λ i I−A T ) −1 C T . This process of computing all “achievable” eigenvectors is repeated for the remaining (n−1) cases. Once these have been determined, the observer gain required to realize this eigensystem is computed according to the following steps. First, add columns to the C T matrix to generate an nxn transformation matrix of full rank:
T=└C T I |P┘, rank(T)=n
Use this T matrix to transform the “dual” system according to:
Ã=T −1 A T T
{tilde over (C)}=T −1 C T
{tilde over (μ)} i =T −1 μ i
Now partioning the à matrix and transformed eigenvector ĩ i as: A ~ = [ A 11 A 12 A 21 A 22 ] , μ ~ i = [ z i w i ] , and A 1 = [ A 11 A 12 ]
where A 11 is rxr, A 12 is rx(n−r), and z i is rx1, we define matrices:
V=[{tilde over (μ)} 1 {tilde over (μ)} 2 . . . {tilde over (μ)} n ]
Z=[λ 1 z 1 λ 2 z 2 . . . λ n z n ]
where V is nxn and Z is rxn. The observer gains are then:
F T =(Z−A 1 V)(TV) −1
The preferred embodiment of the invention 10 as a system is illustrated in FIG. 1. A rotor driven, multi-mode aircraft 12 such as the civilian Bell 609 or the military version V-22 Osprey would be typical of such aircraft. The unique characteristic of such aircraft is that they can fly in either the hover mode, like a helicopter, or in the fixed wing mode, like a typical airplane, or sometimes in between, as when taking off or in a transition mode. Because of this, it is difficult to place traditional icing sensors in a location where the changing dynamics of the plane's flight doesn't adversely affect the reliability of the icing instruments' output. Traditional icing sensors often comprise vibrating rods whose natural frequency changes in the presence of icing conditions or capacitance sensors that can detect the difference between water and ice. The aircraft 12 includes a plurality of sensors 14 that fall into two groups. The first group are traditional icing sensors 14 a that detect icing generally through changes in natural vibrational frequency or through changes in capacitance as previously described. The second set of sensors 14 b detect aircraft performance characteristics such as torque, resulting thrust and rotor blade characteristics. The output 16 from sensor groups 14 a and 14 b is fed along a conventional databus, such as the military 1553 databus, to a comparator 18 . The comparator 18 also receives as a negative feedback, the output 38 of a sensor model 36 which includes the expected aircraft performance data. Comparator 18 has an output 20 that acts as an input to the feedback gain control 22 . Output 20 can change the values of the feedback gains 22 depending upon the mode of flight, e.g. hover vs. fixed wing, and other parameters. The output 24 of feedback gain control 22 provides an input to the aircraft dynamic response model 26 . The aircraft response model 26 has an output 28 that forms the input to the sensor model 36 and the detector logic 40 . Together elements 18 , 22 , 26 and 36 operate in the manner of a recursive filter as discussed in detail previously. Detection logic 40 accepts as one input the output 28 from the dynamic model 26 and as a second input the output 48 of comparator 18 . Based upon this information detector logic 40 produces an output 42 which comprises inputs to a cockpit display 44 and a control signal to the onboard aircraft anti-icing and deicing equipment 46 .
Implementation of the icing detection algorithm, using the fault detection methodology, is illustrated in FIGS. 2 a and 2 b . In this diagram, a gain-scheduled linear model and residual feedback matrix are indexed by flight condition in order to cover the multi-modal flight behavior and icing accretion ranges, of the host aircraft.
While the invention has been described with respect to a preferred embodiment thereof, nevertheless, it will be appreciated by those of ordinary skill in the art that various modifications can be made to the invention without departing from the spirit and scope thereof.
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The present invention comprises a system and method for detecting icing conditions in a multi-mode aircraft by indirectly detecting ice accretion through the measurement of aircraft performance related characteristics. Indirect characteristics are used, sometimes in additional to traditional icing sensor input, because it is difficult to safely and effectively position icing sensors in aircraft that may fly in the hover mode or the fixed wing mode as well as modes in between. Typical indirect characteristics might include thrust and rotor response for a given torque. This information is compared to a model of the expected aircraft performance to determine if icing is likely to take place. For example, decreased thrust or lift for a given torque may indicate the onset of icing. Inputs from the traditional icing sensors may also be employed as additional useful, predictive data. A recursive filter having a variable gain feedback control produces an output predictive of icing conditions and provides warning information to a cockpit display as well as control signals the anti-icing equipment.
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BACKGROUND
[0001] The present invention relates to field effect transistor (FET) devices, and more specifically, to methods for fabrication and multi-gate FET devices.
[0002] Multi-gate FET devices include FinFET devices which are non-planar transistors disposed on a substrate. The FinFET device often includes active source and drain regions and a channel region that are formed from a silicon fin. The channel region is wrapped with gate materials such as polysilicon, metal materials, or high-k materials.
BRIEF SUMMARY
[0003] According to one embodiment of the present invention, a method for forming a field effect transistor device includes patterning an arrangement of fin portions on a substrate, patterning a gate stack portion over portions of the fin portions and the substrate, growing an epitaxial material from the fin portions that electrically connects portions of adjacent fin structures, and removing a portion of the gate stack portion to expose a portion of the substrate.
[0004] According to another embodiment of the present invention, a field effect transistor device includes an arrangement of fin portions disposed on a substrate, a first gate stack portion arranged over the arrangement of fin portions and portions of the substrate, a first epitaxial material connecting portions of the fin portions arranged in a first region defined by a first side of the first gate stack portion, a second epitaxial material connecting portions of the fin portions arranged in a second region defined by a second side of the first gate stack portion, and a second gate stack portion arranged substantially collinear to the first gate stack portion, the first gate stack portion and the second gate stack portion partially defined by a region of the substrate arranged between the first gate stack portion and the second gate stack portion.
[0005] Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention. For a better understanding of the invention with the advantages and the features, refer to the description and to the drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0006] The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The forgoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
[0007] FIG. 1 illustrates a perspective view of an exemplary arrangement of FinFET devices.
[0008] FIGS. 2-14 Illustrate an exemplary method of fabrication and resultant embodiment of FinFET devices. In this regard:
[0009] FIG. 2 illustrates a top view of fin portions arranged on a substrate.
[0010] FIG. 3 illustrates the resultant structure following the removal of a fin portion.
[0011] FIG. 4 illustrates the resultant structure following the formation of gate stack portions.
[0012] FIG. 5 illustrates the resultant structure following the formation of spacers over and adjacent to the gate stack portions.
[0013] FIG. 6 illustrates the resultant structure following the epitaxial growth of an epitaxial material.
[0014] FIG. 7 illustrates a side cut-away view along the line 7 of FIG. 6 .
[0015] FIG. 8 illustrates an example of a photolithographic mask material.
[0016] FIG. 9 illustrates a side cut-away view along the line 9 of FIG. 8 .
[0017] FIG. 10 illustrates the resultant structure following an etching process that removes the exposed portion of the oxide layer.
[0018] FIG. 11 illustrates the resultant structure following an etching process that removes exposed portions of the spacer.
[0019] FIG. 12 illustrates the resultant structure following an etching process that removes exposed portions of the gate stack.
[0020] FIG. 13 illustrates the resultant structure following the removal of the masking layer of FIG. 12 .
[0021] FIG. 14 illustrates a top view of the resultant FinFET structure illustrated in FIG. 13 .
DETAILED DESCRIPTION
[0022] Previous fabrication methods for FinFET devices included forming epitaxial regions that connect portions of adjacent fins of the FinFET devices following the patterning and fabrication of gate stacks. These methods may result in the formation of epitaxial regions that undesirably cause an electrical short between fins on opposing sides of the gate stack due to the geometry of the gate stack and the spacing of the adjacent fins.
[0023] FIG. 1 illustrates a perspective view of an exemplary arrangement of FinFET devices 102 . The FinFET devices 102 include fin portions 104 that are arranged in parallel on an insulator layer 101 of a substrate 100 . A gate stack portion 106 is disposed over portions of the fin portions 104 . A portion of the gate stack portion 106 has been removed such that a region 103 of the substrate 100 is exposed. In some embodiments, an epitaxial growth process may be performed to grow epitaxial material (not shown) from the exposed portions of the fin portions 104 . It is desirable to grow the epitaxial material such that the exposed portions of the fin portions 104 a are connected to each other on one side of the gate stack portion 106 , while the exposed portions of the fin portions 104 b are connected to each other on the opposing side of the gate stack portion 106 . The fin portions 104 are arranged such that the spaces between the fin portions 104 may be filled with the epitaxial material, however it is undesirable to grow epitaxial material in the region 103 since the epitaxial material may form an electrical short between the fin portions 104 a and 104 b. The end of the gate stack portion 106 that defines a distance (x) from the end of the gate stack portion 106 to the adjacent fin portions 104 a and 104 b may sufficient to prevent undesired epitaxial growth in the 103 region, however if the distance x is less than the distance (y) defined by adjacent fin portions 104 , the epitaxial growth in the region 103 may cause a short between the fin portions 104 a and 104 b. Thus, a method for fabricating a structure that allows epitaxial growth to connect adjacent fin portions without connecting opposing fin portions is described below.
[0024] FIG. 2 illustrates a top view of fin portions 202 arranged on a substrate 201 . The substrate 201 may include, for example, an insulator layer. The fin portions 202 may be formed by any suitable process such as, for example, a lithographic patterning and etching process, and may include a silicon or germanium material. The fin portions 202 are arranged substantially parallel to each other, and define a distance (a) between each fin portion 202 .
[0025] FIG. 3 illustrates the resultant structure following the removal of a fin portion 202 using, for example, a lithographic patterning and etching process. Though the illustrated embodiment shows the removal of one fin portion 202 , any number of fin portions 202 may be removed according to design specifications.
[0026] FIG. 4 illustrates the resultant structure following the formation of gate stack portions 402 . The gate stack portions 402 may be formed by any suitable deposition, patterning and etching process. For example, a gate dielectric material (not shown) such as an oxide or high-k material may be disposed over the substrate 201 and the fin portions 202 , and a gate electrode material such as a polysilicon material may be formed over the gate dielectric material. A lithographic patterning and etching process may be used to form the gate stack portions 402 . The fin portions 202 are arranged substantially parallel to each other, and the gate stack portions 402 are arranged substantially perpendicular to the fin portions 202 .
[0027] FIG. 5 illustrates the resultant structure following the formation of spacers 502 over and adjacent to the gate stack portions 402 (of FIG. 4 ). The spacers 502 may include, for example, an oxide or nitride material.
[0028] FIG. 6 illustrates the resultant structure following the epitaxial growth of an epitaxial material 602 that may include, for example, a silicon or germanium material. In this regard, the epitaxial material 602 is grown from exposed portions of the fin portions 202 such that some of the adjacent fin portions 202 are connected. An oxide material 604 may be formed on surfaces of the fin portions 202 and the spacers 502 (or in some embodiments the gate stack portions 402 ) to prevent epitaxial growth from undesired portions of the devices. The epitaxial material 602 is grown from the sidewalls of the fin portions 202 . The epitaxial growth process is timed or metered such that the epitaxial materials 602 grown from adjacent fin portions 202 contact each other. In this regard, the epitaxial growth process is performed such that the epitaxial material 602 grows approximately ½ a from opposing sides of the fin portions 202 . The epitaxial material 602 grown in the region 601 for example, extends from the fin portion 202 a and 202 b, however, the gate stack portion 602 b inhibits epitaxial growth of the epitaxial material 602 that would result in an electrical short or connection between the fin portions 202 a and 202 b via epitaxial material 602 .
[0029] FIG. 7 illustrates a side cut-away view along the line 7 (of FIG. 6 ) and shows epitaxial material 602 arranged on the substrate 201 .
[0030] FIG. 8 illustrates an example of a photolithographic mask material 801 that has been patterned on exposed portions of the substrate 201 , the fin portions 202 , the epitaxial material 602 , and portions of the gate stacks 402 (and/or portions of materials such as the spacers 502 and oxide layer 604 that may be formed over the gates stacks 402 ). A portion of the gate stack 402 a remains exposed.
[0031] FIG. 9 illustrates a side cut-away view along the line 9 (of FIG. 8 ).
[0032] FIG. 10 illustrates the resultant structure following an etching process that removes the exposed portion of the oxide layer 604 . The etching process may include any suitable etching process such as, for example, a dry etching process or reactive ion etching (RIE).
[0033] FIG. 11 illustrates the resultant structure following an etching process that removes exposed portions of the spacer 502 to expose a portion of the gate stack 402 a, such as, for example a dry etching process.
[0034] FIG. 12 illustrates the resultant structure following an etching process that removes exposed portions of the gate stack 402 a. In this regard, the etching process may include a dry etch or RIE process that is selective to the spacer material (e.g., SiN) and oxide materials.
[0035] FIG. 13 illustrates the resultant structure following the removal of the masking layer 801 (of FIG. 12 ), the deposition of an oxide material 1302 over exposed portions of the substrate 201 , and a chemical mechanical process (CMP) or other suitable planarizing process.
[0036] FIG. 14 illustrates a top view of the resultant FinFET structure illustrated in FIG. 13 . The region 1401 illustrates the portion of the gate stack 402 a (of FIG. 4 ) and the spacers 502 that were removed following the growth of the epitaxial material 602 as described above. The gate stack 402 a and the spacers 502 inhibited the growth of epitaxial material 602 in the region 1301 thereby reducing the likelihood that the fin portions 1402 a and 1402 b could be electrically connected or shorted by the epitaxial material 602 . The removal of the portion of the gate stack 402 a in the region 1401 results in gate stack portions 402 a and 402 c arranged collinear along the line 1420 that illustrates longitudinal axis of the gate stack portions 402 a and 402 c, where the gate stack portions 402 a and 402 c are partially defined by the region 1401 .
[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 more other features, integers, steps, operations, element 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
[0039] The diagrams depicted herein are just one example. There may be many variations to this diagram or the steps (or operations) described therein without departing from the spirit of the invention. For instance, the steps may be performed in a differing order or steps may be added, deleted or modified. All of these variations are considered a part of the claimed invention.
[0040] While the preferred embodiment to the invention had been described, it will be understood that those skilled in the art, both now and in the future, may make various improvements and enhancements which fall within the scope of the claims which follow. These claims should be construed to maintain the proper protection for the invention first described.
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A method for forming a field effect transistor device includes patterning an arrangement of fin portions on a substrate, patterning a gate stack portion over portions of the fin portions and the substrate, growing an epitaxial material from the fin portions that electrically connects portions of adjacent fin structures, and removing a portion of the gate stack portion to expose a portion of the substrate.
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FIELD OF THE INVENTION
[0001] The present invention relates to a coffee maker and more specifically to a two cups automatic coffee maker with flow control to make a precise number of cups of coffee and with two different tastes.
BACKGROUND OF THE INVENTION
[0002] Brewing coffee also called dripped coffee method, which is the most common coffee making method. It had been widely used at home and/or commercial such as office and hotel. Today many people use: automatic drip coffee makers to brew coffee because they can have a cup of hot coffee anytime and unlike before had to boil and wait for hot water to make coffee while they can leave and go to do something else.
[0003] Although conventional automatic drip coffee makers work well for their intended purpose, but one problem with their associated use is a typical design of convention drip type coffee maker in which a heater soldered water duct is designed to pump the water from a cold reservoir into the coffee brewing chamber, which is hardly to manage the flow control in a precise manner, particular to a one cup coffee in desired volume. The existing design is always has to pump empty the cold reservoir so that to avoid interrupting the brewing cycle. Therefore to brew only one-cup coffee the coffee maker has to build with a one-cup cold reservoir.
[0004] In order to brew two cups coffee at the same time and able to have different tastes, it is necessary to have the cold reservoir with the volume over two cups, and then to control the flow from the cold reservoir needs not to be pumped empty if only one cup coffee is to be served. Precisely flow control is also vital in considering brewing two cups coffee tandem to avoid excessive coffee slops over the cup, or not enough coffee due to the premature stoppage in the brewing cycle.
[0005] In the meanwhile the design of the conventional automatic drip coffee makers in the existing market are also not reliable in safety concern because the automatic reset thermostat employed in the circuitry cannot stop energizing the machine permanently as soon as the brew is completed. This is inherent fire hazardous especially if the thermal plastic is used for the enclosure. A manual reset thermostat control is therefore built to replace the automatic reset thermostat in order to improve the coffee maker in safety aspect.
SUMMARY OF THE INVENTION
[0006] The present invention address the problems discussed above and aims to provide a coffee maker that has the following features: with flow control in a precise manner; particular to a one cup coffee in desired volume, two reservoirs type design to avoid overfill and able to have different tastes, a manual reset thermostat controls to turn off the heaters while brewing cycle is completed, and cancel button with pause and resume function. These features are embodied in a single construction of the coffee maker.
[0007] The two cups automatic coffee maker of the present invention comprises the following elements: the invention is to redesign the cold reservoir construction so that there are a primary reservoir and a secondary reservoir to manage the flow control precisely for the cups in desired volume particular serving two cups coffee at the same time with different tastes. Both the primary and secondary reservoirs have the volume identical to the cup with the desired volume. Each reservoir is built with a floating block, which is to provide the indication of the amount of water filled.
[0008] The user can choose both reservoirs at the same time in order to brew two cups coffee. Because of the separated basket therefore it is possible to have two different tastes at the same time, with a cancel button to serve as a “pause and resume” function so that user can be paused and resumed in the mid way of the brewing cycle in which the convention drip type coffee maker does not have this function at all.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is the sectional view of the two cups automatic coffee maker.
[0010] FIG. 2 is the side sectional view of the two cups automatic coffee marker.
[0011] FIG. 3 is the sectional view of the sluice-valve of the two cups automatic coffee marker.
[0012] FIGS. 4 a , 4 b and 4 c are the embodiment of the two cups automatic coffee maker for brewing two different tastes at the same time.
[0013] FIG. 5 is the structural view of the manual reset thermal control of the two cups automatic coffee maker.
DETAILED DESCRIPTION OF THE INVENTION
[0014] As shown in FIG. 1 and FIG. 2 , the two cups automatic coffee maker with flow control it comprises: a main house 1 , primary reservoir 2 , secondary reservoir 3 , floating block 4 , main switch 5 , switch mount 6 , switch cover 7 , cancel button 8 , top cover 9 , coffee filters 10 , coffee filter holder 11 , brewing chamber 12 , sprinkle heads 13 , heater soldered water ducts 14 , water pipes 15 , drip tray 16 , manual reset thermal controls 17 , bottom cover 18 , pusher 19 , horizontal linkage 20 , disc shape bimetal 21 , terminals 22 , spring 23 , switching mechanism 24 , sluice-valve 25 , adjustable screw 26 .
[0015] As shown in FIG. 2 the two cups automatic coffee maker with flow control, the spring loaded main switch 5 is a kind of momentary ‘ON’ press switch, in which is designed to have the stroke length controlled not able to activate the switching mechanism 24 unless the horizontal linkage(s) 20 is/are in place. It will bounce back to its initial position if not holding the press.
[0016] There is a switching mechanism 24 in each Primary reservoir 2 and Secondary reservoir 3 . This switching mechanism 24 is designed to sit on top of the reservoir and consists of a long bar hooked to the manual reset thermal control 17 . When the reservoir 2 or 3 is filled with enough water and the main switch 5 is pressed it pull up the manual reset thermal control 17 to close the circuitry via this long bar.
[0017] The cancel button 8 is designed to stop the brewing cycle or to break the electric circuitry manually. This button is also spring loaded and is designed to link with the switching mechanism 24 . When this button is pressed it will push open the manual reset thermal control 17 via the long bar and break the electric circuitry, thus to stop the brewing cycle.
[0018] As shown in FIG. 5 the two cups automatic coffee maker with flow control, the manual reset thermal control 17 , in which designed like a v-shape clothing-pinch, is consists of a disc shape bimetal 21 , two terminals 22 and a spring 23 , is built underneath in each Primary reservoir 2 and Secondary reservoir 3 . The disc shape bimetal 21 is used to sense the temperature drift and will deform upon reaching the dry boil temperature. The two terminals 22 are wired to the circuitry and serves as the open/close function. When the manual reset thermal control 17 is at the open stage the two terminals 22 making no contact, vice versa they contact each other when the manual reset thermal control 17 is at the close position, thus form the close-loop electric circuitry. The spring 23 is designed to help the manual reset thermal control 17 stays firmly and mechanically either at the open or close position. As soon as the brewing cycle is completed and the disc shape bimetal 21 deformed after sensing the dry boiling, it triggers the spring 23 and push open the manual reset thermal control 17 so that the electric circuitry stays permanently open.
[0019] As shown in FIGS. 4 a , 4 b and 4 c the two cups automatic coffee maker with flow control, the Primary and Secondary reservoirs 2 & 3 have their separated sprinkle head 13 . The sprinkle heads 13 from both reservoirs are linked up to the main switch 5 for selecting the mug on either left/right/or both sides. When turn the main switch 5 to the left hand side for brewing only one cup coffee shown in 4 a , both the sprinkle heads 13 are sitting on top of the coffee filter 10 at the left so that the hot water can be pumped from the primary reservoir 2 , or the secondary reservoir 3 when the primary reservoir 2 is empty. This concept applies the same to the right hand side selection shown in 4 c . When the main switch 5 stays at the middle for brewing 2 cup coffees shown in 4 b , the sprinkle heads 13 are now sitting separately to the coffee filters 10 at left and right sides. With the separated coffee filter 10 design it allows the selection of 2 different tastes coffee.
[0020] In the primary reservoir 2 when there is water filled the floating block 4 will rise up and activate a horizontal linkage 20 so that it links up with the switching mechanism 24 built to this primary reservoir. When the user selects to brew one cup only and the push button is pressed with both the sprinkle heads 13 at either left or right orientation the switching mechanism 24 actives and it starts to energize the heater soldered water duct 14 underneath the primary reservoir 2 . When the primary reservoir 2 pumps empty then the manual reset thermal control 17 will break the circuitry completely upon the sensing of dry boiling, and the coffee maker stays permanently off.
[0021] The secondary reservoir 3 is built adjacent to the primary reservoir 2 and will collect water excessive to the primary reservoir 2 volume. It also builds with the floating block 4 in which the design is, when the water not filled to its maximum, even it is half filled, the floating block 4 cannot activate the switching mechanism 24 thus far the main switch 5 cannot activate the circuitry and start the brewing. This can ensure the primary reservoir 2 is to be used prior to the secondary reservoir 3 whenever the primary reservoir 2 is filled. Underneath the secondary reservoir 3 it is an identical design the manual reset thermostat control 17 will break the circuitry when the reservoir is pumped empty.
[0022] As shown in FIG. 3 the two cups automatic coffee maker with flow control, in between the primary reservoir 2 and secondary reservoir 3 there is a partition that has a cut open at one end to allow the excess water flow from the primary reservoir 2 to the secondary reservoir 3 . A sluice-valve 25 sits at the cut open, which has a screw 26 mounted on the top of the reservoirs adjusts its height. When adjusting the height of the sluice-valve 25 , the water level of both of the primary reservoir 2 and the secondary reservoir 3 are adjusted at the same time. The excess water of the primary reservoir 2 will drain out to the secondary reservoir 3 through the sluice-valve 25 and consequently the excess water of the secondary reservoir 3 will drain out from the coffee maker also through this sluice-valve 25 . The sluice-valve 25 is capable to control the water level inside both the reservoirs means the user can deliberately to control the desired volume of one-cup coffee by the adjustable screw 26 to adjust the height of the sluice-valve 25 .
[0023] The present invention provide a selection for brewing two cups of coffee at the same time or brewing two cups of coffee in tandem explain as the following details operation description as stated.
[0024] When brewing two cups of coffee at the same time, both primary reservoir 2 and secondary reservoir 3 are empty and the floating blocks 4 are sitting at the bottom. When both primary reservoir 2 and secondary reservoir 3 filled with water, both floating blocks 4 rise up and swing their own horizontal linkages 20 so that they both linking up with their own switching mechanism 24 in the separated primary and secondary reservoirs. When the main switch 5 points to the middle shown in 4 b for selection of brewing two cups, with the horizontal linkages in place, press down the main switch 5 now able to trigger both manual reset thermal controls 17 . Pusher 19 is integrated to the main switch 5 is also used to hold the selection of the sprinkle heads 13 . Sprinkle heads 13 now are sitting on top of both the coffee filters 10 when the main switch 5 points to middle, thus allowing the hot water to drain over the 2 independent coffee filters 10 and brew 2 different tastes of coffee. Upon the activation of the manual reset thermal control 17 it short the electric circuit and the heater soldered ducts 14 start to energize, hence the brewing cycle begin until both primary reservoir 2 and secondary reservoir 3 drain empty. When the disc shape bimetal 21 built inside the manual reset thermal control 17 senses the temperature drifted to dry boiling, it triggers and activate the manual reset thermal control 17 to break the electric circuit, thus the brewing cycle completed. Manual reset thermal control 17 at the open circuit stage and floating blocks 4 remain sitting at the bottom while both reservoirs showed empty.
[0025] When brewing two cups of coffee in tandem, both primary reservoir 2 and secondary reservoir 3 filled with water and both the floating blocks 4 rise up, consequently the horizontal linkages 20 swing to link up both the switching mechanisms 24 . Main switch 5 turns to the left for selecting the left mug shown in 4 a or turns to right for selecting the right mug shown in 4 c , the pusher 19 will link both the sprinkle heads 13 on top of the left coffee filter 10 (or link both the sprinkle heads 13 on top of the right coffee filter 10 if turns to right). Press down the main switch 5 will only activate the manual reset thermal control 17 underneath the primary reservoir 2 hence starts the brewing cycle for a single cup. As soon as the manual reset thermal control 17 activated, the heater soldered water duct 14 starts to pump the water from the primary reservoir 2 into the left coffee filter 10 until the primary reservoir 2 is empty. As long as the primary reservoir 2 is empty, the floating block 4 drops down to its bottom. The horizontal linkage 20 swings back to initial position. When the disc shape bimetal 21 of the manual reset thermal control 17 detect the temperature drifted due to the dry boiling, it triggers the manual reset thermal control 17 and breaks open the electric circuit, thus stop the brewing cycle. Press the main switch 5 once again with the selection of either left or right mug, the main switch 5 now only have the horizontal linkage 20 of the secondary reservoir 3 underneath, hence it only can activate the manual reset thermal control 17 from the secondary reservoir 3 . The heater soldered water duct 14 will start pumping the water from the secondary reservoir 3 into either the left or right coffee filter 10 , and brewing the second cycle. As long as the secondary reservoir 3 drains empty and finished the brew, the floating block 4 drops to its bottom, the horizontal linkage 20 swings back to its initial position, and the manual reset thermal control 17 break the electric circuit after detecting the dry boiling temperature.
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The present invention relates to a coffee maker and more specifically to a two cups automatic coffee maker with flow control in a precise manner, particular to a one cup coffee in desired volume, a two reservoirs type design to avoid overfill and able to have two different tastes, with a manual reset thermostat controls to turn off the heaters while brewing cycle is completed.
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This is a division of application Ser. No. 07/967,917 filed on Oct. 28, 1992, which is now U.S. Pat. No. 5,362,557 and incorporated by reference herein, and which is a continuation of application Ser. No. 07/570,025, filed Aug. 20, 1990, now abandoned.
BACKGROUND OF THE INVENTION
This invention generally relates to wear resistant decorative laminates having excellent scratch, mar, scrape and abrasion resistance and methods of producing the same. More particularly, this invention relates to wear resistant, decorative laminates employing a decorative sheet saturated with a melamine-formaldehyde resin coating incorporating abrasive materials.
Conventionally, decorative laminates are made of two essential layers: a core layer and a surface layer. The core layer constitutes a bottom or supporting layer onto which the other layer is bonded. In normal high-pressure laminate manufacture, the core layer consists of a plurality of cellulosic sheets. The core sheets are generally made from a kraft paper impregnated with a laminating resin. Laminating resins commonly used for the core layer include phenolic, amino, epoxy, polyester, silicone, and diallyl phthalate resins to name a few. The industrially preferred laminating resin for decorative laminates is a phenolic resin made from the reaction of phenols with formaldehyde.
Placed above the core layer is a decorative layer which is generally an alpha cellulose pigmented paper containing a print, pattern design or solid color that has been impregnated with a melamine-formaldehyde resin.
The cured melamine-formaldehyde resins are colorless and resistant to light; they are resistant to a variety of solvents and stains; and their heat resistance make them resistant to burning cigarettes. boiling water and heated containers up to about 325° F. Without these melamine-formaldehyde resins, the decorative laminate industry would not exist as it is known today. However, because these resins are extremely brittle, they sometimes require reinforcement.
When the decorative layer of the laminate is a printed pattern, it is covered with an overlay as it is commonly referred to, which is a high-quality alpha cellulose paper impregnated with a melamine-formaldehyde resin. This layer protects the decorative print from external abuse such as abrasive wear and tear, harsh chemicals, burns, spills and the like. It is primarily the melamine-formaldehyde resin which accounts for these protective properties. The alpha-cellulose paper acts as a translucent carrier for the water-thin resin, imparts strength to the rather brittle melamine-formaldehyde resin, maintains a uniform resin thickness in the overlay by acting as a shim, and controls resin flow.
The core layer, decorative layer and the overlay surface layer (when needed) are stacked in a superimposed relationship, between polished steel plates and subjected to a pressure and temperature for a time sufficiently long enough to cure the laminating resins impregnating the respective layers. The elevated temperature and pressure actually cause the impregnated resins within the sheets to flow, which consolidates the whole into an integral mass known as the laminate. These laminates are used as surfacings for counter tops, table tops, furniture, store fixtures and the like.
Abrasive materials have previously been employed in the overlay sheet or solid color decorative sheet in order to improve the abrasion resistance of the laminate. The abrasive materials are generally deposited upon the alpha cellulose matrix or, in other applications, mixed with celluosic fibers or microcrystalline materials replacing the alpha cellulose overlay sheet.
Incorporation of abrasive materials in the decorative or overlay sheet can cause severe damage to the delicate, highly polished or intricately etched surfaces of the press plates when the abrasive particles deposited in the decorative or overlay sheet come into contact therewith.
Thus, there exists the need for substitution of a resin in the decorative or overlay sheet that will provide excellent surface damage resistance without damaging the delicate plates. Also incorporation of abrasive materials in laminates can cause objectional wear on materials rubbed across them. The provision for such a layer would fulfill a long-felt need and constitute a significant advance in the art.
DESCRIPTION OF THE PRIOR ART
Prior art procedures for the manufacture of abrasion-resistant decorative laminates, such as those taught in U.S. Pat. No. 4,255,480, have generally required a multi-step process in which the decorative facing sheet is first coated with a binder/mineral mixture and then dried to bind the abrasion-resistant mineral to the decorative sheet. The dry coated decorative sheet is then impregnated with a thermosetting resin. However, this particular prior art process calls for the utilization of a binding material compatible with the thermosetting resin, namely microcrystalline cellulose, to bind the mineral particles to the decorative sheet. Thus, this prior art process requires a specific binding compound compatible with the thermosetting resin, and separate coating, drying and impregnating steps.
Others have attempted production of mar-resistant decorative laminates. For instance, U.S. Pat. No. 4,263,081 teaches the production of a mar-resistant laminate but further requires that a second layer of binder/mineral mixture be provided immediately below or above the first binder/mineral layer.
U.S. Pat. No. 4,305,987 is directed to an abrasion-resistant laminate meeting National Electric Manufacturers' Association (NEMA) standards relating to abrasive wear, strain resistance, heat resistance, impact resistance, dimensional stability and the like. The patent discloses a "stabilizing binder material" for the abrasion-resistant mineral. The patent also teaches the use of microcrystalline cellulose as the preferred binder material, acting as a suspending and binding agent and also compatible with melamine and polyester laminating resins.
U.S. Pat. No. 4,327,141 discloses an abrasion-resistant decorative laminate meeting National Electric Manufacturers Association (NEMA) standards. The abrasion-resistant laminate requires an additional layer of binder material immediately below or above the abrasion resistant coating.
U.S. Pat. No. 4,395,452 discloses a print sheet for use in the preparation of abrasion-resistant decorative laminates, and requires the presence of binder material "in an amount sufficient to bind and stabilize" the abrasion-resistant mineral to the surface of the paper sheet.
U.S. Pat. No. 4,400,423 also discloses a print sheet for use in the preparation of abrasion-resistant decorative laminates, however additionally discloses use of an additional layer of binder material immediately above or below the abrasion-resistant coating.
U.S. Pat. No. 4,430,375 teaches a decorative sheet for use in the preparation of abrasion-resistant decorative laminates and the use of a binder material. Additionally, the process for producing the laminate discloses a separate drying step to enhance the bonding of the abrasion-resistant mineral particles to the decorative sheet.
U.S. Pat. No. 4,499,137 discloses a scuff-resistant decorative laminate utilizing a wax lubricant having a melt temperature below 260° F. so as to avoid haze in the laminate.
Both U.S. Pat. No. 4,517,235 and 4,520,062 disclose an abrasion-resistant coating for decorative laminates in which a binder/mineral coating is transferred from a mold surface or flexible tape to the surface of the laminate. Additionally, a transfer carrier containing a non-resinous binder material and mineral abrasive particles is disclosed.
U.S. Pat. No. 4,532,170 discloses a facing sheet for a scuff-resistant decorative laminate, comprising a particulate lubricant and binder material for the lubricant particles, but excluding oxidized wax and silicone resin lubricants.
U.S. Pat. No. 4,567,087 teaches a scuff-resistant and abrasion-resistant decorative laminate comprising abrasion-resistant particles, binder material for the particles, and a lubricant which is not an oxidized wax or silicone resin.
U.S. Pat. No. 4,713,138 discloses a single step method of preparing a facing sheet for use as the uppermost sheet in the manufacture of an abrasion-resistant decorative laminate. The method teaches a binding material for the mineral that (1) withstands the subsequent laminating conditions, (2) is compatible with the thermosetting resin, (3) is present in an amount sufficient to bind the abrasion-resistant mineral to the surface of an unsaturated paper sheet, and (4) suspends the abrasion-resistant mineral particles in the liquid thermosetting resin.
Finally, U.S. Pat. No. 4,741,946 discloses scuff and abrasion-resistant decorative laminates in which finely divided lubricant wax particles are incorporated in or very near the surface of the solid-colored decorative paper. The lubricant is disclosed as not being an oxidized wax or silicone resin.
SUMMARY OF THE INVENTION
It is a principal object of this invention to provide laminates having excellent resistance to all known types of physical damage to the surface that cause marring or defacement. This includes scraping by a relatively sharp object of about equal hardness to the laminate resulting in a burnish mark (polished streak) or a chalk mark (transfer of material from the abrading object to the laminate); scratching by a very sharp object of about the same hardness as the grit in the laminate resulting in a groove of plowed away material; and mars such as a series of very closely spaced scratches caused by many very fine particles of about equal hardness to the grit in the laminate such as contained in sandpaper, a scouring pad or air-borne dirt trapped beneath a tool used to fabricate a laminate or an object slid across the installed laminate.
It is a further object of this invention to provide laminates which do not require the use of a separate grit binding step or a discrete binder; thus, allowing simultaneous coating and impregnating of the decorative paper sheet with a mixture containing both the thermosetting resin and the grit.
It is a further object of this invention to provide the above mentioned excellent scratch, mar, scrape and abrasion resistance in a laminate having a very even, uniformly fine textured matte finish providing a surface gloss of about 14 (Gardener 60°)
It is a further object of this invention to provide the above mentioned excellent scratch, mar, scrape and abrasion resistance in a laminate having a very even, uniform glossy surface finish.
It is still a further object of this invention to protect the expensive and delicate plates, used to produce high pressure decorative laminates, from undue or premature wear caused by the inclusion in the laminate surface of hard abrasive particles and to prevent an objectionable deposit of worn metal fragments on the surfaces of light colored laminates.
The foregoing objects and others are accomplished in accordance with the present invention by employing the preferred embodiments of the invention.
These and other objects of the present invention will be apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicative of the preferred embodiment of the invention, are given by way of illustration only, because various changes and modifications within the spirit and scope of the invention will become apparent from this detailed description to those skilled in the art.
In accordance with these objectives of the present invention, a new high pressure decorative laminate has been developed which has excellent resistance to scratching, marring, scraping and abrasion.
The decorative laminates having excellent scratch, mar, scrape and abrasion resistance utilize a coating formulation which comprises a thermosetting resin; abrasion resistant particles, of a particle size and in a concentration sufficient to provide for abrasion resistance; a coupling agent in an amount dependent upon the concentration of the abrasion resistant particles; a thickening agent in an amount sufficient to suspend the abrasion resistant particles; and a lubricating agent in a concentration sufficient to impart scrape resistance to the decorative laminate.
DETAILED DESCRIPTION OF THE EMBODIMENTS
The preferred embodiment for the decorative laminates having excellent scratch, mar, scrape and abrasion resistance utilize a coating formulation mixture comprising melamine-formaldehyde resin to which the following is added, in terms of weight units per weight units of wet resin 1.6 percent w./w. wet resin A1 2 O 3 (alumina) grit particles having a particle size or at least 25 microns; 0.8 percentage w./w. wet resin Al 2 O 3 (alumina) grit particles having a particle size of at least 3 microns; from about 0.3 percent w./w. wet resin to about 1.2 percent w./w. wet resin polyvinyl alcohol; 0.25 percent silane coupling agent based upon the amount of grit used; 0.075 percent w./w. wet resin xanthan gum thickener; and 0.1 percent polythylene glycol distearate having a molecular weight of about 6000. The melamine-formaldehyde resin may also be modified with a plasticizer and/or an acid catalyst if a more flexible wear-resistant laminate is desired. The preferred catalyst is paratoluene sulfonic acid; however, any kind of acid such as magnesium bromide, hydrochloric acid, sulfuric acid or the like may be utilized as a catalyst.
The melamine formaldehyde resin coating formulation additionally contains polyvinyl alcohol as an auxiliary slip agent. A polyethylene wax known by the tradename AC316from Allied Chemical Company was evaluated as an auxiliary slip agent, however was found to impart haze and blur to the resulting decorative laminate. The polyvinyl alcohol functions to impart resistance to marks from sliding objects (sometimes referred to as "scuff": resistance) to the resulting laminate.
The melamine-formaldehyde resin coating formulation additionally contains a silane coupling agent the amount based upon the desired amount of grit utilized in the laminate; an alginate thickener such as xanthan gum to suspend the grit particles and protect the plates used in the laminate production process from undue wear causing metal mar marks on light colored laminates; and polyethylene glycol distearate having a molecular weight of about to enhance surface slip and improve scrape resistance of the laminate. The polyethylene glycol distearate having a molecular weight of about used in the resin coating formulation is preferred lubricating agent, as it provides scrape resistance. Zinc stearate and other lubricating compounds were evaluated for scrape resistance, but were found less effective.
The coating formulation may also contain a small amount (0.01-0.1 percent w./w. wet resin) of a surfactant designed to reduce surface tension of the coating to provide a smooth and a uniform deposition of the coating. An example of such agent is Silwet® L-77 from Union Carbide Co. L-77 is a dimethylpolyoloxane.
The decorative laminates and methods for producing same disclosed herein do not require the use of a separate grit (abrasion resistant mineral particle) binding step employing a discrete binder. Because the invention disclosed herein does not require a separate binding step or a discrete binder, simultaneous coating and impregnating of the decorative paper sheet with a mixture containing both the thermosetting resin and the grit can be undertaken to simplify the laminate production process and the laminate itself.
The resulting decorative laminate utilizing the melamine formaldehyde resin coating formulation as described above has excellent scratch resistance imparted by the 25 micron alumina grit. The laminate additionally has excellent mar resistance imparted by the 3 micron alumina grit. The 3 micron alumina grit, being smaller, has much more surface area and thus provides more complete coverage of the laminate surface. However, the larger, 25 micron alumina grit particles are necessary to provide scratch resistance to the laminate. This is because mar is produced by many very small, closely spaced particles covering a broad area of the abrading object and, because of the broad coverage, pressure is very low. In contrast, a scratch is produced by a single larger hard, sharp object that is under greater pressure as a result of its small contact area with the laminate surface.
Two processes may be used to produce the wear-resistant laminates having either a matte finish or glossy finish. It is well understood in the art that the surface finish of the resulting decorative laminate, whether a matte finish or glossy finish laminate is achieved, is dependent upon the surface texture of the pressing plates used in the consolidation of the laminate.
One process which may be used to produce the wear resistant decorative laminate is the sparge pipe process. With the sparge pipe process, the resin coating formulation is applied to a decorative paper sheet using a sparge pipe having many holes to spread the resin coating formulation uniformly across the top side of the decorative paper. A first sparge coating supplies nearly all of the required resin, about 80 percent of the resin normally used to saturate a decorative sheet to provide NEMA specified properties to a high pressure decorative laminate. In a second step, the wet resin-coated decorative paper is further dipped into an identically formulated resin coating mixture which supplies the remainder of the required resin. The total resin pick-up by the decorative sheet is regulated by metering-squeeze rollers. It has been found that inferior scratch and mar resistance is obtained if the decorative paper is dipped only into the resin coating formulation without the prior sparge process. The resin coated decorative paper and at least one backing sheet is dried and then heat and pressure consolidated using conventional techniques into a high pressure decorative laminate having excellent scratch, mar, scrape and abrasion resistance. It is well understood that more than one sheet of backing paper may be used to produce laminates of varying thicknesses.
The second process which may be used to produce the wear-resistant high pressure decorative laminates is the gravure pad coating process. With this process, the resin coating formulation is first applied to the surface of the raw decorative paper sheet using a gravure pad coating cylinder. When applied in this manner, the decorative paper sheet picks up only about 20 percent of the required amount of resin identified above so the percentage of grit in the coating formulation must be increased to about 15 percent so that a sufficient amount of the abrasive grit is imparted to the decorative sheet. In a second step subsequent to the gravure coating, either with or without an intermediate drying step, the decorative paper sheet is dipped into the resin coating formulation containing neat melamine-formaldehyde resin, which is resin which has not been modified with the abrasive grit, to supply the remainder of the required amount of resin to saturate the sheet. The resin pick-up by the decorative sheet is regulated by metering squeeze rollers. Coating the decorative sheet with a coating formulation which uses a neat melamine-formaldehyde resin has been found to render the coating process less damaging to the highly polished stainless steel plates used for producing high gloss laminates.
The coated decorative paper and at least one backing sheet is dried and then heat and pressure consolidated using conventional techniques into a high pressure decorative laminate having excellent scratch, mar, scrape and abrasion resistance. It is well understood that more than one backing sheet may be used to produce laminates of varying thicknesses.
In order to further define the specifics of the present invention, the following examples are provided and intended to illustrate the high pressure decorative laminate having improved scratch, mar, scrape and abrasion resistance and the process for producing the laminate, and not to limit the particulars of the present invention:
EXAMPLE 1
Laminate samples having a matte finish were subjected to four different testing procedures to measure scratch, mar, scrape and abrasion resistance. The matte laminate samples tested included:
(1) Standard FORMICA® brand high pressure decorative laminate having a matte finish;
(2) FORMICA® brand high pressure decorative laminate having a matte finish which additionally contained polyethylene glycol distearate having a molecular weight of about 6000 in the resin coating;
(3) FORMICA® brand high pressure decorative laminate having a matte finish which additionally contained 0.8 percent w./w. wet resin of 6 micron alumina grit particles in the resin coating, the resin coating being applied to the decorative sheet by dip and squeeze application;
(4) a high pressure decorative matte finish laminate produced by the sparge pipe process and having a decorative sheet impregnated with a resin coating formulation containing 1.5 percent w./w. wet resin micron alumina particle grit, xanthan gum and polyethylene glycol 6000 distearate:
(5) a high pressure decorative matte finish laminate produced by the sparge pipe process and having a decorative sheet impregnated with a resin coating formulation containing 1.6 percent w./w. wet resin 25 micron alumina particle grit, 0.8 percent w./w. wet resin 3 micron alumina particle grit, xanthan gum, and polyethylene glycol distearate having a molecular weight of about;
(6) a matte finish wear-resistant laminate known as NEVAMAR ARP®.
Each of the above-described laminate samples was subjected to the following four test procedures:
I. GLASS SCRATCH TEST
This test was designed to measure the ease with which a laminate could be scratched using a material of similar sharpness and hardness to ordinary silica, the usual scratching component in air-borne dirt. Scratches are very thin lines, usually several inches long and widely spaced one from another. Material is plowed out by the scratch-inducing agent and the indentation in the laminate surface can usually be felt by running a fingernail over it.
Each of the 6 laminate samples described above were scratched four times with the edge of a glass microscope slide (Fisher brand Cat. No. 12-550A 75×25 mm--non-frosted) held in a device to which loads of 25, 50, 100 and 200 grams could be applied. The laminate surfaces were observed visually and the resulting surface scratches were rated as follows:
0=no mark visible under these conditions
1=very, very faint scratch visible if tilted to a critical angle
2=very faint scratch--easier to see than a #1
3=faint scratch--fairly easy to see at most angles
4=easily visible scratch that will disappear at a critical angle
5=a scratch easily visible at any angle under good light.
The results were then totalled for all scratches on the particular laminate sample. The results appear in TABLE I below.
II. MAR-TEST
The mar resistance of each of the laminate samples was determined by rubbing the laminate surface under controlled conditions with an abrasive cloth (blue grit utility cloth grade 280J type 311 T, by 3M Company) and then measuring the change in surface gloss of the marred area as compared to the original surface gloss. The change in surface gloss was measured by a 60° glossmeter manufactured by Gardner Laboratory Division, Bethesda, Md.
The mar resistance for each laminate sample was calculated as follows: ##EQU1## Mar resistance tends to depend disproportionately on the original background gloss of the laminate. The glossier the laminate, the higher the ΔG value. ΔG=the percent change in gloss (mar resistance)
NOTE: Burnishing (surface gloss increase), will be a negative value.
The results of the mar resistance for each laminate sample are set forth below in TABLE I.
III. SCRAPE TEST
This test was intended to measure the likelihood of the surface of one laminate to be scraped by the sharp corner of the surface of another laminate being dragged across it. Scrape is a long, narrow streak that may appear as a burnish (higher gloss) or as a whitish, chalky mark.
Each of the laminate samples were scraped five times using neutral gray, solid color FORMICA® brand laminate chips, grade 1058. The laminate surfaces of the samples were then visually observed and the surface scrapes were rated as follows:
0=no visible mark
1=a burnish (higher gloss) mark that disappears as the sample is rotated to various angles.
2=a burnish mark visible at all viewing angles.
3=a chalk mark that disappears as the sample is rotated at various angles.
4=a chalk mark visible at all viewing angles.
NOTE: If the scrape appeared to "skip" such as burnish to chalk or burnish to nothing, the scrape was graded according to the greatest severity of the scrape.
The results of the test were totalled and averaged for all scrapes on the particular laminate sample. The results appear in TABLE I below.
IV. ABRASION TEST
This test measured the ability of the surface of a high pressure decorative laminate to maintain its design and color when subjected to abrasive wear.
Each of the laminate samples were uniformly abraded for 750 cycles using 180 grit alumina oxide sandpaper strips 1/2 inch (12.7 mm) wide by 6 inches (152.4 mm) long. After 750 cycles, the resulting groove depth in the laminate surface was measured to determine abrasion resistance. The results of the abrasion resistance test are summarized below in TABLE I.
TABLE I______________________________________ ABRASION (Groove Depth SCRATCH MAR SCRAPE at 750SAMPLE (0-20 scale) (% ΔG) (0-4 scale) cycles) (mils.)______________________________________1 14 34 1-2 --(Control)2 14 34 1 --3 11 9 2-3 2.44 6.4 -4.7 1.8 1.55 3.7 -7.5 1.9 0.86 5 -8.2 2 0.8______________________________________
TABLE I shows that the standard FORMICA® brand laminate product having a matte finish had poor scratch and mar resistance and fair scrape resistance. The addition of small microgrit slightly improved scratch and substantially improved mar, but was detrimental to scrape resistance. Increasing the level of small grit, applying it to the decorative sheet surface with a sparge pipe and including the polyethylene glycol distearate, substantially improved scratch and mar resistance (a negative value means the sample burnished or became glossier when abraded) and the polyethylene glycol distearate improved scrape resistance in spite of the presence or grit. This higher level of surface applied grit also reduced the groove depth resulting from 750 cycles of abrasion. Finally, the mixed grit including the larger size 25 micron particles and the smaller size 3 micron particles, brought about a further improvement in scratch resistance and reduced the abrasion groove depth by half. The polyethylene glycol distearate continued to maintain good scrape resistance.
EXAMPLE 2
The purpose of this example was to test scratch, abrasion and mar resistance in wear-resistant high pressure decorative laminates having a glossy finish produced by either the sparge pipe process or gravure process and having varying amounts and particle sizes of alumina grit in the resin coating formulation impregnated in the decorative sheet.
The following eight laminate samples were tested:
(1) A control sample of glossy finish standard FORMICA® brand laminate having no alumina grit particles;
(2) A glossy finish laminate produced by the sparge pipe process and having 2.5 percent w./w. wet resin 3 micron alumina particle grit in the resin coating;
(3) A glossy finish laminate produced by the sparge pipe process and having 0.8 percent w./w. wet resin 9 micron alumina grit particles in the resin coating;
(4) A glossy finish laminate produced by the sparge pipe process and having 1.5 percent w./w. wet resin 9 micron alumina grit particles in the resin coating;
(5) A glossy finish laminate produced by the gravure process and having 10 percent w./w. wet resin 9 micron alumina grit particles in the resin coating;
(6) A glossy finish laminate produced by the gravure process and having 15 percent w./w. wet resin 9 micron alumina grit particles in the resin coating;
(7) A glossy finish laminate produced by the sparge pipe process and having a mixture of 1.6 percent w./w. wet resin 25 micron Al 2 O 3 grit particles and 0.8 percent w./w. wet resin 3 micron Al 2 O 3 grit particles in the resin coating;
(8) Nevamar® "Glossie"wear-resistant decorative laminate.
Each of the above laminates was tested for scratch resistance, abrasion resistance and mar resistance using the testing procedures previously described in EXAMPLE 1. The results of the testing are set forth below in TABLE II.
TABLE II______________________________________ Scratch Abrasive Mar Resistance Improvement Improvement Improvement (times better (times better (% improvementSample than control) than control) over control)______________________________________1 1 1 0(Control)2 1 0.9* 94.33 1.4 1.3 93.74 2 1.4 98.05 2 2.8 99.26 7 3.6 99.87 14 ∞** 99.48 3.7 1.5 88.5______________________________________ *This sample was black. All others in the series are white, containing high levels (30-35%) of TiO.sub.2. TiO.sub.2 itself provides a degree of wear resistance that is as good or better than 2.5% 3μAl.sub.2 O.sub.3 in a low ash (black) sample. **The depth of a groove in the control laminate worn in by 500 cycles of sandpaper abrasion was divided by the depth of groove in each of the experimental laminate samples. The groove depth in Sample 7 was zero. Thu the ratio approaches infinity.
The data in TABLE II shows that virtually any inclusion of microgrit substantially improves mar resistance because all samples improved 93.7% to 99.8% in this property as compared to the control. This is a very narrow range and all experimental samples would be considered to have good mar resistance. However, when considering scratch resistance, only the samples with very high grit levels or the larger particle size grit have good values. The best sample (Sample 7) (mixed grit) is 14 times better than the control. The next best sample (Sample 6) is 7 times better, meaning that only half as good scratch resistance was achievable with the 9 micron particle size grit as compared to the 25 micron particle size grit. Finally, in abrasive wear, only Sample 7 made with 25 micron particle size grit showed an immeasurable groove depth after 500 abrasion cycles.
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Process for the production of decorative laminates having improved scratch, mar, scrape and abrasion resistance comprising the initial step of preparing a mixture of a melamine-formaldehyde resin and an abrasion resistant material, wherein the mixture includes abrasion resistant alumina particles having a particle size of about 25 microns and abrasion resistant alumina particles having a particle size of about 3 microns at a ratio of about 2 to 1; about 0.25 percent silane; about 0.075 percent xanthan gum; and about 0.3 percent to about 1.2 percent polyvinyl alcohol or about 0.1 percent polyethylene glycol distearate having a molecular weight of about 6000, wherein all percentages are measured by weight of the total wet weight of the resin solution of the mixture. The process further includes the steps of simultaneously coating and impregnating a decorative paper sheet with the mixture such that a portion of the amount of melamine-formaldehyde resin required for saturation of the decorative sheet is impregnated therein; dipping the impregnated decorative sheet into an identically formulated mixture or a neat resin bath such that the remaining amount of resin required for saturation is impregnated therein; metering the total amount of melamine-formaldehyde resin impregnated into the decorative sheet; and then drying and consolidating the impregnated decorative sheet. The coating and impregnating step can be performed using either a sparge pipe applicator or a gravure pad coating cylinder.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims benefit under 35 USC 119(e) of U.S. Provisional Patent Application No. 62/021,626, filed on Jul. 7, 2014, entitled “INTEGRATED CMOS AND MEMS SENSOR FABRICATION METHOD AND STRUCTURE,” which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to CMOS-MEMS integrated devices and more particularly to method of fabrication for CMOS-MEMS integrated devices.
BACKGROUND
[0003] Traditionally to provide a CMOS-MEMS structure with at least one cavity therein a high bonding force (300 psi or greater) is required at a high temperature (above 400 degrees) to effectively bond the CMOS substrate to a MEMS substrate. The high temperature causes high stresses on the bonded structure. In addition, a timed etch to form a standoffs is required and therefore to control a gap height in the structure can be difficult to achieve. Accordingly, what is needed is a system and method to address the above identified issues. The present invention addresses such a need.
SUMMARY
[0004] A method of providing a CMOS-MEMS structure is disclosed. The method comprises patterning a first top metal on a MEMS actuator substrate and a second top metal on a CMOS substrate. Each of the MEMS actuator substrate and the CMOS substrate include an oxide layer thereon. The method includes etching each of the oxide layers on the MEMS actuator substrate and the base substrate, utilizing a first bonding step to bond the first patterned top metal of the MEMS actuator substrate to the second patterned top metal of the base substrate. Finally the method includes etching an actuator layer into the MEMS actuator substrate and utilizing a second bonding step to bond the MEMS actuator substrate to a MEMS handle substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a diagram of a CMOS-MEMS structure in accordance with an embodiment.
[0006] FIG. 2 is a flow chart of the process flow of a fabrication of a CMOS-MEMS structure in accordance with an embodiment.
[0007] FIGS. 3A-3F are diagrams that illustrate fabrication of a CMOS-MEMS structure in accordance with the process flow of FIG. 2 .
DETAILED DESCRIPTION
[0008] The present invention relates generally to CMOS-MEMS integrated devices and more particularly to method of fabrication for CMOS-MEMS integrated devices. The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the preferred embodiment and the generic principles and features described herein will be readily apparent to those skilled in the art. Thus, a method and system in accordance with the present invention is not intended to be limited to the embodiment shown but is to be accorded the widest scope consistent with the principles and features described herein.
[0009] In the described embodiments Micro-Electro-Mechanical Systems (MEMS) refers to a class of structures or devices fabricated using semiconductor-like processes and exhibiting mechanical characteristics such as the ability to move or deform. MEMS often, but not always, interact with electrical signals. MEMS devices include but are not limited to gyroscopes, accelerometers, magnetometers, pressure sensors, and radio-frequency components. Silicon wafers containing MEMS structures are referred to as MEMS wafers.
[0010] In the described embodiments, MEMS device may refer to a semiconductor device implemented as a micro-electro-mechanical system. MEMS structure may refer to any feature that may be part of a larger MEMS device. An engineered silicon-on-insulator (ESOI) wafer may refer to a SOI wafer with cavities beneath the silicon device layer or substrate. Handle wafer typically refers to a thicker substrate used as a carrier for the thinner silicon device substrate in a silicon-on-insulator wafer. Handle substrate and handle wafer can be interchanged.
[0011] In the described embodiments, a cavity may refer to an opening or recession in a substrate wafer and enclosure may refer to a fully enclosed space. Bond chamber may be an enclosure in a piece of bonding equipment where the wafer bonding process takes place. The atmosphere in the bond chamber determines the atmosphere sealed in the bonded wafers.
[0012] Additionally, a system and method in accordance with the present invention describes a class of RF MEMS devices, sensors, and actuators including but not limited to switches, resonators and tunable capacitors that are hermetically sealed and bonded to integrated circuits that may use capacitive sensing and electrostatic, magnetic, or piezo-electric actuation.
[0013] In order to bond a CMOS substrate with a MEMS substrate to CMOS substrate to form a CMOS-MEMS integrated device a process is utilized which provides for two steps. A first bonding step bonds a top metal layer of the MEMS substrate to a top metal layer of the CMOS substrate and a second bonding step bonds a MEMS handle layer to the MEMS actuator layer. Both of these bonding steps can be performed at low temperature (150-400 degrees C.) at a reduced pressure. Both of the bonding steps also can be utilized to provide a hermetic seal for the device.
[0014] Accordingly, this process overcomes some of the issues associated with high temperature bonding processes. Namely a process in accordance with the present invention eliminates the high bonding force requirement associated with the traditional eutectic bond between the CMOS substrate and the MEMS substrate and therefore reduces stresses and minimizes warping of the bonded structure since a high temperature is not required.
[0015] In addition the gap height control is improved over conventional bonding processes for CMOS-MEMS integrated devices. Finally using the process in accordance with the present invention a timed etch to form standoffs on the CMOS-MEMS integrated device is no longer required. The processes described below provide for the fabrication of CMOS-MEMS integrated devices using first and second low temperature bonding steps to create a sealed enclosure between the MEMS and CMOS wafers. The first bonding step comprises a metal to metal bond that can provide electrical connection between a MEMS substrate and a CMOS substrate. The second bonding step comprises a fusion bond that coupled a handle layer of the MEMS substrate to an actuator layer of the MEMS substrate and does not provide for any electrical interconnection.
[0016] Below is provided an approach available with a method and system in accordance with the present invention, in one or more embodiments, providing for the integration of such devices to create a CMOS-MEMS integrated device. In the described embodiments, the CMOS wafer may be replaced by any suitable capping wafer or substrate.
[0017] FIG. 1 is a diagram of a CMOS-MEMS structure in accordance with an embodiment. For the embodiment, it will be appreciated that a CMOS-MEMS integrated device 100 comprises a MEMS substrate 102 and a CMOS substrate 104 . The CMOS substrate 104 includes a bump stop 119 that can in an embodiment composed of metal 120 such as Copper or Nickel surrounded by an oxide layer 122 . The bump stop 119 can be electrically connected to the underlying metal or can be electrically isolated. The MEMS substrate 102 includes a MEMS actuator layer 106 and a MEMS handle layer 108 with at least one cavity 110 bonded to the MEMS actuator layer 106 through a dielectric layer 112 disposed between the MEM handle layer 108 and the MEMS actuator layer 106 . The MEMS actuator layer 106 also includes a moveable portion 114 .
[0018] A top metal 118 of the CMOS substrate 104 and a top metal 120 of the MEMS actuator layer 106 are used to first bond the CMOS substrate 104 to the MEMS actuator layer 106 . The top metal 118 of the CMOS substrate 104 includes a contact layer 124 which is composed of for example Titanium Nitride (TiN). In an embodiment, the top metal 118 and 120 can be made of materials that bond at temperatures between 150-400 degrees C. degrees that include but are not limited to any of copper (Cu) and nickel (Ni). The standoffs 130 are formed via an etch of the oxide layers 122 on the CMOS substrate 104 and the MEMS actuator layer 106 .
[0019] The MEMS actuator layer 106 is coupled to the MEMS handle layer 108 and the dielectric layer 112 via a second bond. In an embodiment, the first bond comprises a compression bond for a metal to metal connection that is provided at a temperature in the range of 150-400 degrees C. and the second bond comprises a fusion bond which is also provided at a temperature in the range of 150-400 degrees C.
[0020] In an embodiment, first and second bonds are implemented utilizing the Direct Bond Interconnect (DBI) process which has been developed by Ziptronix Inc. To describe the features of the present invention in more detail refer now to following discussion in conjunction with the accompanying Figures.
[0021] FIG. 2 is a flow chart of the process flow of a fabrication of a CMOS-MEMS structure in accordance with an embodiment. FIGS. 3A-3F are diagrams that illustrate fabrication of a CMOS-MEMS structure in accordance with the process flow of FIG. 2 . Referring to FIGS. 2 and 3 A- 3 F together, first, top metals 118 and 120 are patterned on the CMOS substrate 104 and the MEMS actuator layer 106 as shown in FIG. 3A , via step 202 . Thereafter an oxide layer is etched on the CMOS substrate 104 and the MEMS actuator layer 106 as shown in FIG. 3B to form the standoffs 130 and the bump stop 119 , via step 204 .
[0022] Thereafter the top metals 118 and 120 of the CMOS substrate 104 and the MEMS actuator layer 106 are bonded using a low temperature bond as shown in FIG. 3C , via step 206 . As before mentioned, in an embodiment the low temperature bond is in a temperature range of 150-400 degrees C. In an embodiment, MEMS actuator layer 106 is ground down to a desired thickness. The desired thickness in some embodiments is between 10-100 microns. Through the first bond an electrical or conductive connection is made between the CMOS substrate 104 and the MEMS actuator layer 106 .
[0023] Thereafter, the MEMS actuator layer 106 is etched to provide a movable portion 114 as shown in FIG. 3D , via step 208 . Then a cavity 110 is formed and a MEMS handle layer 108 is oxidized as shown in FIG. 3E , via step 210 . Thereafter the MEMS handle layer 108 is bonded to the MEMS actuator layer 106 as shown in FIG. 3F , via step 212 .
[0024] A process in accordance with the present invention provides the following features:
[0025] 1. Utilizes a low temperature process that reduces stresses on the device while still having a high bond energy.
[0026] 2. Provides bonded electrical interconnections between MEMS substrate and CMOS substrate.
[0027] 3. Provides a well controlled gap between the CMOS substrate and the MEMS substrate
[0028] 4. Does not require a top anchor for the MEMS substrate because the Moveable MEMS structure is only anchored to the CMOS substrate, making it less sensitive to external stresses placed on the MEMS handle substrate.
[0029] Although the present invention has been described in accordance with the embodiments shown, one of ordinary skill in the art will readily recognize that there could be variations to the embodiments and those variations would be within the spirit and scope of the present invention. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the present invention.
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A method of providing a CMOS-MEMS structure is disclosed. The method comprises patterning a first top metal on a MEMS actuator substrate and a second top metal on a CMOS substrate. Each of the MEMS actuator substrate and the CMOS substrate include an oxide layer thereon. The method includes etching each of the oxide layers on the MEMS actuator substrate and the base substrate, utilizing a first bonding step to bond the first patterned top metal of the MEMS actuator substrate to the second patterned top metal of the base substrate. Finally the method includes etching an actuator layer into the MEMS actuator substrate and utilizing a second bonding step to bond the MEMS actuator substrate to a MEMS handle substrate.
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FIELD OF THE INVENTION
The present invention relates to automatic transmissions and more particularly to an internal transmission range selection system using electronic controls.
BACKGROUND OF THE INVENTION
Motorized vehicles include a power plant (e.g., engine or electric motor) that produces driving power. The driving power is transferred through a transmission to a driveline for driving a set of wheels at selected gear ratios. As is well known, automatic transmissions shift automatically to the appropriate gear ratio based on various vehicle operating conditions including speed and torque. Typically, a desired transmission operating mode or range is selected by the vehicle operator. The ranges provided by most automatic transmissions generally include Park, Neutral, Reverse and Drive. In Drive, the automatic transmission automatically shifts between three, four, five or even six different forward gear ratios based on the vehicle operating conditions.
Traditionally, a driver interface device is provided which the vehicle operator shifts to select the desired transmission range. The driver interface device is linked to the automatic transmission by a range shift mechanism which typically includes a series of interconnected mechanical devices such as levers, push/pull rods, cables and the like. The number and size of such mechanical components make it difficult to package the range shift mechanism between the driver interface device and the transmission and can add significant frictional resistance to the overall system. As a result, the overall cost for design, manufacture and assembly of the vehicle is increased.
In an attempt to address such issues related to mechanically-shifted transmission range shift mechanisms, several “shift-by-wire” range shift mechanisms have been developed. Typically, a shift-by-wire range shift mechanism is based on an external system having an electric motor for controlling movement of the transmission's manual shaft to the desired range select position. Switches associated with the driver interface device send a mode signal to a transmission controller that is indicative of the selected transmission range. Thereafter, the controller actuates the electric motor to move the transmission manual shaft to the corresponding range select position. Drawbacks of conventional shift-by-wire systems include the size and weight of the external motor, the associated packaging issues related to the motor, the cost of the motor and the controller and the undesirable failure modes associated with such a device.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides a solenoid assembly for implementation with an electronic transmission range selection (ETRS) system that shifts a transmission range between a park position and an out-of-park position. The solenoid assembly includes an extension arm biased against a member of the ETRS system. The extension arm is movable to an extended position to maintain the member in the out-of-park position. A solenoid is interconnected with the extension arm. The solenoid is operable to selectively move the extension arm between the extended position and a retracted position to selectively retain the member in the out-of-park position.
In one feature, the solenoid assembly further includes a plunger interconnecting the extension arm and the solenoid to pull the extension arm to the retracted position when the solenoid is de-energized.
In another feature, the solenoid assembly further includes a locking mechanism to selectively lock the extension arm in the extended position when the member is in the out-of-park position and the solenoid is energized. The locking mechanism includes an inner sleeve selectively actuated by the solenoid and bearings disposed between the inner sleeve and the extension arm. When the extension arm is in the extended position and the solenoid is energized the inner sleeve biases the bearings against the extension arm to prohibit movement of the extension arm to the retracted position. When the solenoid is de-energized a bias force of the inner sleeve against the bearings is relieved to enable movement of the extension arm to the retracted position. The extension arm and the inner sleeve each include respective conical faces in between which the bearings are wedged to retain the extension arm in the extended position when the solenoid is energized.
In still another feature, the solenoid assembly further includes a spring that biases the extension arm toward the member.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. 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
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is a schematic illustration of a vehicle system incorporating an electronic transmission range selection (ETRS) system according to the principles of the present invention;
FIG. 2 is a side view of the ETRS system in a Park mode;
FIG. 3 is a side view of the ETRS system in an Out-of-Park mode;
FIG. 4 is a detailed view of a portion of the ETRS system detailing pressurized fluid flow therethrough in the Out-of-Park mode;
FIG. 5 is an exploded view of a detent lever assembly associated with the ETRS system of the present invention;
FIG. 6 is a cross-sectional view of a park solenoid assembly associated with the ETRS system shown in a Park position; and
FIG. 7 is a cross-sectional view of the park solenoid assembly shown in an Out-of-Park position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
Referring now to FIG. 1 , a schematic illustration of a vehicle 10 is shown. The vehicle 10 includes an engine 12 and an automatic transmission 14 . The engine 12 produces driving torque that is transferred through the transmission 14 at varying gear ratios to drive at least one pair of wheels (not shown). A driver interface device 16 enables a vehicle operator to select various transmission range positions. The driver interface device 16 can include a lever, switches, dials, push-buttons or any other type of input interface desired. The normal transmission range positions, including Park, Reverse, Neutral, and Drive (PRND) are selectable, as well as manual downshifts and tap-up, tap-down capabilities via actuation of the driver interface device 16 . In operation, the driver interface device 16 sends an electric mode signal to a controller 18 based on the selected transmission range.
The controller 18 signals an electronic transmission range selection (ETRS) system 20 to shift the transmission 14 to the corresponding range in response to the electric mode signal. For purposes of clarity, the ETRS system 20 is considered to be operating in a “Park” mode when the transmission 14 is in its Park range and to be operating in an “Out-of-Park” mode when the transmission 14 is in any other of the available ranges.
Referring now to FIG. 2 , the ETRS system 20 is an integral part of the transmission 14 and is operable to manipulate the flow of pressurized fluid to shift the transmission 14 between its available transmission ranges. The ETRS system 20 includes a park servo valve 22 , a park servo valve solenoid 24 , a forward-reverse enable (FRE) valve 26 , a hydraulic servo assembly 28 and a two-position detent lever assembly 30 . The ETRS system 20 also includes a park solenoid 32 that prevents shifting from the Out-of-Park mode into the Park mode in the event of a loss of pressurized fluid under specific circumstances.
Referring now to FIGS. 2 through 4 , the ETRS components are shown supported within a housing 34 associated with the transmission 14 and which defines a valve body having a series of fluid flow passages. FIG. 2 illustrates the position of the various components when the ETRS system 20 is shifted into its Park mode. In contrast, FIGS. 3 and 4 illustrate the same components moved to positions corresponding to the ETRS system 20 operating in its Out-of-Park mode. In particular, the park servo valve 22 is slidably supported within the housing 34 for movement between a first position ( FIG. 2 ) and a second position ( FIG. 3 ). The park servo valve 22 is biased to its first position by a spring 36 . The spring 36 is disposed between a fixed spring seat 38 and the park servo valve 22 . In its first position, the park servo valve 22 prohibits the flow of pressurized fluid to the hydraulic servo assembly 28 . As discussed in further detail below, the park servo valve solenoid 24 can be selectively actuated to control the supply of fluid required for moving the park servo valve 22 between its first and second positions.
Referring still to FIGS. 2 through 4 , the hydraulic servo assembly 28 is shown to include a servo pin 40 having a servo piston 42 fixed to one end. The servo piston 42 is slidably supported within a cylinder 44 formed in the housing 34 and includes a piston seal 46 disposed therearound. A port 47 formed in the housing 34 provides a fluid communication path to a pressure chamber 48 formed within the cylinder 44 . The servo piston 42 and servo pin 40 are biased to a first position (see FIG. 2 ) by a spring 50 and the detent lever assembly 30 . The spring 50 seats between the servo piston 42 and a servo cap 52 that is fixed to the housing 34 by a retainer ring 54 . An opposite end of the servo pin 40 abuts one end of the FRE valve 26 and is also fixed to a first end of an elongated servo link rod 56 . The servo link rod 56 operably connects servo pin 40 to the detent lever assembly 30 . As described in further detail below, the flow of pressurized fluid through the port 47 into the pressure chamber 48 induces movement of the servo piston 42 and servo pin 40 to a second position (see FIGS. 3 and 4 ) against the biasing force exerted thereon by the spring 50 and the detent lever assembly 30 . Movement of the servo pin 40 from its first position to its second position causes the servo link rod 56 to likewise move from a first position ( FIG. 2 ) to a second position ( FIG. 3 ). Furthermore, such movement of the servo pin 40 to its second position acts to release it from engagement with the FRE valve 26 .
The FRE valve 26 is slidably disposed within a valve chamber formed in the housing 34 for movement between a first position and a second position. When the servo pin 40 of the hydraulic servo assembly 28 is in its first position, the spring 50 and the detent lever assembly 30 hold FRE valve 26 in its first position ( FIG. 2 ) in opposition to the biasing force exerted thereon by a spring 58 . As seen, the spring 58 is seated between the FRE valve 26 and a wall portion of the housing 34 . In its first position, the FRE valve 26 blocks the flow of pressurized fluid to the shifting components of the transmission 14 . However, upon movement of the servo pin 40 of the hydraulic servo assembly 28 to its second position, the biasing force of the spring 58 forcibly moves the FRE valve 26 to its second position ( FIGS. 3 and 4 ). With the FRE valve 26 in its second position, the flow of pressurized fluid from port 60 is permitted to the shifting components of transmission 14 through ports 60 and 63 at a desired line pressure.
Referring primarily to FIG. 5 , the detent lever assembly 30 is shown to include a detent lever 62 , a bushing 64 and a manual shaft 66 . The manual shaft 66 is rotatably supported in one or more aligned apertures in the transmission case and extends through the bushing 64 . The bushing 64 is retained in an aperture 68 formed in the detent lever 62 , whereby the detent lever 62 is rotatably supported by the bushing 64 .
The manual shaft 66 includes a flat 70 formed along a portion thereof. The manual shaft 66 is received through a keyed aperture 72 of the bushing 64 . In particular, the flat 70 of the manual shaft 66 engages a key 74 in the bushing 64 , thereby fixing the manual shaft 66 and bushing 64 for concurrent rotation. However, the detent lever 62 is free to rotate about the bushing 64 . As a result, during normal operation, the manual shaft 66 does not rotate as the ETRS system 20 is moved from the Park position to the Out-of-Park position, thereby eliminating any drag associated with a manual release mechanism external to the transmission 14 .
The bushing 64 includes a raised circumferential flange 59 having a slot 61 which forms a pair of laterally-spaced engagement faces 63 . A pin 65 extends from an aperture 67 in the detent lever 62 and into the slot 61 in the bushing 64 . When the manual shaft 66 and the bushing 64 are induced to rotate, as discussed in further detail below, one of the engagement faces 63 eventually contacts the pin 65 to induce rotation of the detent lever 62 . The open space provided by the arc length of the slot 61 defines a range of free-motion for the detent lever 62 . That is to say, during normal operation, the detent lever 62 is rotatable relative to the bushing 64 with the pin 65 traveling within the slot 61 without contacting one of the engagement faces 63 .
The detent lever 62 further includes a J-shaped slot 76 with a pin 77 fixed to the second end of the servo link rod 56 engaging the slot 76 . As such, servo link rod 56 connects detent lever 62 to the servo pin 40 of hydraulic servo assembly 28 . A park solenoid pin 78 extends from an aperture 79 in the detent lever 62 and, as will be detailed, interfaces with moveable components of the park solenoid 32 . An aperture 80 formed through the detent lever 62 facilitates attachment of a first end of an actuator rod 82 to the detent lever 62 . A torsion spring 84 is disposed about the bushing 64 and functions to bias the detent lever 62 to rotate to a park position ( FIG. 2 ). A first end 86 of the torsion spring 84 rests against a stationary anchor portion 88 of the transmission case while a second end 90 of the torsion spring 84 engages a flange segment 92 of the detent lever 62 .
The second end of the actuator arm 82 is coupled to, or engages, an actuator assembly 94 that is operable to selectively move a park lug 96 between a Park range position and the Out-of-Park range position. As will be detailed, movement of servo pin 40 from its first position to its second position causes the servo link rod 56 to pull on the detent lever 62 . In response, the detent lever 62 is induced to rotate from its park position to an out-of-park position ( FIG. 3 ) against the biasing force of the torsion spring 84 . Such rotary movement of the detent lever 62 causes the actuator rod to move from a first position ( FIG. 2 ) to a second position ( FIG. 3 ) for moving park lug 96 to its Out-of-Park range position.
Referring now to FIGS. 6 and 7 , the components associated with the park solenoid assembly 32 will be discussed in greater detail. The park solenoid assembly 32 includes an exterior body 100 that is attached to a portion of housing 34 . The park solenoid assembly 32 also includes a solenoid body 102 which has a solenoid plunger 104 , an extension arm rod 106 that is slidably disposed within the solenoid plunger 104 , and an extension arm 108 that is slidably disposed on the solenoid body 102 and the exterior body 100 . The extension arm rod 106 is fixed to slide with the extension arm 108 . A front face 110 of the extension arm 108 is biased against the park solenoid pin 78 by a spring 111 . As shown in FIG. 7 , when the detent lever 62 is rotated to its out-of-park position, the extension arm 108 and extension arm rod 106 move toward an extended position under the biasing force exerted by the spring 111 . Movement of the extension arm 108 to the fully extended position is limited by a flange 113 formed by the exterior body 100 .
When the ETRS system 20 is in the Out-of-Park position, the extension arm 108 is able to move to the fully extended position under the biasing force of the spring 111 and is stopped by the flange 113 . Under certain circumstances, for example when the vehicle 10 is traveling above a threshold speed, the controller 18 energizes the park solenoid assembly 32 to prevent movement of the solenoid plunger 104 by locking it in the previously staged Out-of-Park position. More specifically, bearings 112 are supported in apertures 114 of the solenoid body 102 . As the solenoid plunger 104 is induced to extend, the bearings 112 ride up a conical face 116 of the solenoid plunger 104 and engage a conical face 118 of the extension arm 108 . The interface between the bearings 112 and the conical faces 116 , 118 prohibit the extension arm 108 from moving back from its extended position. As such, the detent lever 62 is prohibited from rotating back as a result of the contact between the park solenoid pin 78 and the face 110 of the extension arm 108 .
When the vehicle 10 is operating at or below the threshold speed, the park solenoid assembly 32 is de-energized to enable the ETRS system 20 to shift into the Park mode if so desired. More specifically, to enable rotation of the detent lever 62 back to its park position, the park solenoid assembly 32 is de-energized to enable the solenoid plunger 104 to return to the retracted position under the biasing force of a spring 119 to disengage the bearings 12 . As the solenoid plunger 104 retracts, the extension arm 108 is pushed by the detent lever 62 against the bias of the spring 111 enabling rotation of the detent lever 62 to its park position if so indicated.
In operation, the vehicle operator selects a desired transmission range through manipulation of the driver interface device 16 . The driver interface device 16 sends an electronic signal to the controller 18 . The controller 18 commands a transmission range shift by sending an appropriate mode signal to the ETRS system 20 . The transmission range shift includes shifting the transmission range from Park to an Out-of-Park range and enabling the flow of pressurized fluid at a desired transmission line pressure to shift components (not shown) of the transmission 14 .
The signal sent from the controller 18 to the ETRS system 20 actuates the park servo valve solenoid 24 to enable flow of pressurized fluid to the park servo valve 22 through a port 120 (see FIG. 2 ). This flow of pressurized fluid causes movement of the park servo valve 22 from its first position to its second position. With of the park servo valve 22 located in its second position, pressurized fluid is supplied from the park servo valve 22 to the hydraulic servo assembly 28 . More specifically, the pressurized fluid flows into an inlet port 124 of the park servo valve 22 and through an outlet port 122 and the port 47 into pressure chamber 48 of the hydraulic servo assembly 28 . This flow of pressurized fluid into the pressure chamber 48 causes movement of the servo pin 40 from its first position to its second position, in opposition to the biasing of spring 50 . Such sliding movement of servo pin 40 causes corresponding movement of the servo link rod from its first position to its second position which, in turn, causes rotation of the detent lever 62 from its park position to its out-of-park position. Such rotation of the detent lever 62 induces a pulling force on the actuator rod 82 , thereby shifting the transmission range to the Out-of-Park position.
Concurrently, movement of the servo pin 40 of the hydraulic servo assembly 28 to its second position enables movement of the FRE valve 26 from its first position to its second position due to the biasing force of the spring 58 . Movement of the FRE valve 26 to its second position permits flow of pressurized fluid from port 60 to port 63 . This flow of pressurized fluid is provided to the shifting components of the transmission 14 at the desired line pressure, enabling the transmission 14 to shift to the desired range.
Following actuation of the ETRS system 20 into its Out-of-Park mode (see FIGS. 3 and 4 ), the park solenoid assembly 32 is actuated. In particular, the extension arm 108 contacts the park solenoid pin 78 , thereby prohibiting the detent lever 62 from rotating back to its park position. The park solenoid assembly 32 maintains the extension arm 108 in its extended position while the vehicle 10 is traveling above the threshold speed. In the event of a loss of fluid pressure, the actuator assembly 94 is prevented from shifting the transmission range into Park while the vehicle is moving. Once the vehicle 10 is below the threshold speed, and assuming there is no fluid pressure holding the ETRS system 20 in the Out-of-Park mode, the park solenoid assembly 32 is de-energized to retract the extension arm 108 and permit the torsion spring 84 to rotate the detent lever 62 to shift the transmission range into the Park position.
The ETRS system 20 can be manually actuated in the event of a loss of electrical power and fluid pressure within the vehicle 10 . An accessible handle or cable (not shown) is connected for rotation with the manual shaft 66 . A vehicle operator or maintenance personnel can manually rotate the manual shaft 66 using the handle or cable to induce rotation of the detent lever 62 from its park position to its out-of-park position. As described above, rotation of the detent lever 62 enables shifting of the transmission range to the Out-of-Park position. In this manner, the vehicle 10 is free to roll without the transmission prohibiting rolling motion.
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.
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A solenoid assembly for implementation with an electronic transmission range selection (ETRS) system that shifts a transmission range between a park position and an out-of-park position. The solenoid assembly includes an extension arm biased against a member of the ETRS system. The extension arm is movable to an extended position to maintain the member in the out-of-park position. A solenoid is interconnected with the extension arm. The solenoid is operable to selectively move the extension arm between the extended position and a retracted position to selectively retain the member in the out-of-park position.
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FIELD OF THE INVENTION
This invention is directed generally to turbine blades, and more particularly to the cooling systems of turbine blades having internal cooling systems.
BACKGROUND
Typically, gas turbine engines include a compressor for compressing air, a combustor for mixing the compressed air with fuel and igniting the mixture, and a turbine blade assembly for producing power. Combustors often operate at high temperatures that may exceed 2,500 degrees Fahrenheit. Typical turbine combustor configurations expose turbine blade assemblies to these high temperatures. As a result, turbine blades must be made of materials capable of withstanding such high temperatures. In addition, turbine blades often contain cooling systems for prolonging the life of the blades and reducing the likelihood of failure as a result of excessive temperatures.
Typically, turbine blades, as shown in FIG. 1 , are formed from a root portion at one end and an elongated portion forming a blade that extends outwardly from a platform coupled to the root portion at an opposite end of the turbine blade. The blade is ordinarily composed of a tip opposite the root section, a leading edge, and a trailing edge. The inner aspects of most turbine blades typically contain an intricate maze of cooling channels as shown in FIGS. 2 and 3 forming a cooling system. The cooling channels in the blades receive air from the compressor of the turbine engine and pass the air through the blade. The cooling channels often include multiple flow paths that are designed to maintain all aspects of the turbine blade at a relatively uniform temperature. However, centrifugal forces and air flow at boundary layers often prevent some areas of the turbine blade from being adequately cooled, which results in the formation of localized hot spots. Localized hot spots, depending on their location, can reduce the useful life of a turbine blade and can damage a turbine blade to an extent necessitating replacement of the blade.
Typically, conventional turbine blades have a collection of exhaust orifices in the leading edge forming a showerhead for exhausting cooling gases onto the leading edge of the turbine blade. Many conventional configurations of the showerhead orifices have the orifices aligned in the same orientation. Aligning the orifices in the same orientation of the showerhead often leads to cracking of the leading edge, as shown in FIG. 4 , which is often referred to as zipper effect cracking as the cracks extend between adjacent orifices radially along the leading edge. Thus, a configuration of orifices for a leading edge is needed that produces an effective film cooling gas distribution and reduces the likelihood of zipper cracks forming in the leading edge of the blade.
SUMMARY OF THE INVENTION
This invention relates to a cooling system in a turbine blade capable of being used in turbine engines. The cooling system includes a plurality of exhaust orifices in a leading edge of the turbine blade forming a showerhead for providing film cooling gases to outer surfaces of the turbine blade. The exhaust orifices forming the showerhead may be positioned to reduce the likelihood of zipper effect cracking in the leading edge and to effectively cool the leading edge of the turbine blade.
The turbine blade may be formed from a generally elongated blade having a leading edge, a trailing edge, and a tip at a first end. The blade may also include a root coupled to the blade at an end generally opposite the first end for supporting the blade and for coupling the blade to a disc of a turbine blade assembly. The blade may also include one or more cooling cavities extending from the root through a substantial portion of the blade generally along a longitudinal axis of the blade for supplying cooling gases from the root to various portions of the turbine blade. A plurality of exhaust orifices at various locations across the turbine blade enable cooling gases flowing through the cooling cavities to be exhausted from the blade and used in film cooling applications on the turbine blade.
At least a portion of the exhaust orifices are positioned in the leading edge of the turbine blade forming a showerhead in which cooling gases from the cooling cavity is exhausted to be used in film cooling applications. The exhaust orifices extend from an outer surface of the turbine blade to the cooling cavity. The exhaust orifices form at least first and second rows of orifices positioned along the longitudinal axis of the blade. The first row of orifices may be offset from the second row of orifices orthogonal to the longitudinal axis of the blade. Some of the orifices forming the first row may extend through an outer wall of the turbine blade at a first angle relative to a longitudinal axis in a plane generally orthogonal to a chordwise direction, and other orifices forming the first row may extend through the outer wall at a second angle that differs from the first angle. In at least one embodiment, the first angle is measured moving from the longitudinal axis in a first direction in a plane generally orthogonal to a chordwise direction and the second angle is measured moving from the longitudinal axis in a second direction generally opposite to the first direction in a plane generally orthogonal to a chordwise direction. The first and second angles may or may not be equal, and may be between about five degrees and about 45 degrees. The second row may also be formed from orifices positioned at first and second angles relative to the longitudinal axis.
The first and second rows may be formed from an alternating pattern of orifices positioned in the first and second angles relative to the longitudinal axis. Additional rows may also be placed in the alternating pattern. Positioning the first and second rows in the alternating pattern reduces the likelihood that the leading edge will suffer a crack, often referred to as a zipper crack, in the outer wall of the turbine blade, even if the orifices are placed in a high density configuration. The orifices forming the first and second rows may also be formed in the following repeating pattern: an orifice at the first angle relative to the longitudinal axis, an orifice positioned along the longitudinal axis, an orifice at the second angle relative to the longitudinal axis, an orifice positioned along the longitudinal axis, and an orifice at the first angle relative to the longitudinal axis.
By positioning the exhaust orifices in the leading edge in these manners, the exhaust orifices provide more efficient convection on the leading edge and thereby reduce operating temperatures of the leading edge. In addition, these patterns of exhaust orifices increase the distances between adjacent exhaust orifices in the radial direction, which is along the longitudinal axis of the blade, and reduce the conduction distance between hot gas side surface in the chordwise direction, thereby increasing convection efficiency without compromising the strength of the leading edge. Instead, these patterns reduce the likelihood of zipper effect cracking along the leading edge.
These and other embodiments are described in more detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and form a part of the specification, illustrate embodiments of the presently disclosed invention and, together with the description, disclose the principles of the invention.
FIG. 1 is a perspective view of a conventional turbine blade.
FIG. 2 is cross-sectional view of the turbine blade shown in FIG. 1 taken along section line 2 — 2 .
FIG. 3 is a partial cross-sectional detail view of the turbine blade taken at detail 3 in FIG. 2 .
FIG. 4 is a detail view of a leading edge shown in FIG. 3 viewed in the direction of arrow 4 .
FIG. 5 is a perspective view of a turbine blade of this invention.
FIG. 6 is a cross-sectional view of the turbine blade shown in FIG. 5 taken along section line 6 — 6 .
FIG. 7 is a partial cross-sectional detail view of the turbine blade taken at detail 7 in FIG. 6 .
FIG. 8 is a partial cross-sectional view of the outer wall forming the leading edge shown in FIG. 7 taken at section line 8 — 8 .
FIG. 9 is a detail view of the leading edge of the turbine blade shown in FIG. 7 as viewed in the direction of arrows 9 .
FIG. 10 is a detail view of the leading edge of the turbine blade having an alternative configuration of exhaust orifices as shown in FIG. 7 and viewed in the direction of arrows 9 .
FIG. 11 is a detail view of the leading edge of the turbine blade having an alternative configuration of exhaust orifices as shown in FIG. 7 and viewed in the direction of arrows 9 .
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIGS. 5–11 , this invention is directed to a turbine blade cooling system 10 for turbine blades 12 used in turbine engines. In particular, turbine blade cooling system 10 is directed to a cooling system formed from a cavity 14 , as shown in FIG. 6 , positioned between two or more walls 24 of the turbine blade 12 . As shown in FIG. 5 , the turbine blade 12 may be formed from a root 16 having a platform 18 and a generally elongated blade 20 coupled to the root 16 at the platform 18 . Blade 20 may have an outer surface 22 adapted for use, for example, in a first stage of an axial flow turbine engine. Outer surface 22 may be formed from walls 24 having a generally concave shaped portion forming pressure side 26 and may have a generally convex shaped portion forming suction side 28 .
The blade 20 may include one or more cooling channels 32 , as shown in FIG. 6 , positioned in inner aspects of the blade 20 for directing one or more gases, which may include air received from a compressor (not shown), through the blade 20 and exhausted out of the blade 20 . The cooling channels 32 are not limited to a particular configuration but may be any configuration necessary to adequately cool the blade 20 . In at least one embodiment, as shown in FIG. 6 , the cooling channels 32 may include a plurality of channels 32 extending generally along a longitudinal axis 42 of the blade 20 . The blade 20 may be formed from a leading edge 34 , a trailing edge 36 , and a tip 38 at an end generally opposite to the root 16 .
The leading edge 34 may include a plurality of exhaust orifices 44 forming a showerhead 46 for exhausting cooling an from the cooling channels 32 to flow along the outer surface 22 of the blade. The plurality of exhaust orifices 44 may form one or more rows of orifices 44 . In at least one embodiment, a first row of exhaust orifices 48 and a second row of exhaust orifices 50 may be formed. The exhaust orifices 44 may be positioned in a nonorthogonal position relative to an outer surface 22 of the blade 20 . For instance, as shown in FIG. 8 , the exhaust orifices 44 may be positioned at an angle β of between about 20 degrees and about 35 degrees relative to the outer surface 22 of the blade 20 . The distance 3D between adjacent exhaust orifices 44 along the longitudinal axis 42 may be about three times the diameter of the exhaust orifices 44 . The exhaust orifices 44 may be positioned such that air flowing from the root 16 through the cooling channels 32 radially outward toward the tip 38 may flow easily through the exhaust orifices 44 .
The first row 48 and the second row 50 of orifices 44 may be offset relative to each other generally orthogonal to the longitudinal axis 42 of the blade 20 such that the first and second rows 48 , 50 generally follow the longitudinal axis 42 . In at least one embodiment, as shown in FIGS. 9–10 , a third row 52 may also be offset relative to each other generally orthogonal to the longitudinal axis 42 of the blade 20 such that the first and second rows 48 , 50 generally follow the longitudinal axis 42 . In addition to the rows 48 , 50 , 52 being offset orthogonally relative to the longitudinal axis 42 , the first, second, and third rows 48 , 50 , 52 may be offset relative to each other along the longitudinal axis 42 . In other words, the first, second, and third rows 48 , 50 , 52 may be offset radially along the blade 20 .
In one embodiment, as shown in FIG. 9 , the first row 48 may be formed from exhaust orifices 44 positioned at different angles from each other relative to the longitudinal axis 42 . For instance, the first row 48 may be formed from exhaust orifices 44 at either a first angle α relative to the longitudinal axis 42 in a plane generally orthogonal to a chordwise direction or a second angle θ relative to the longitudinal axis 42 in a plane generally orthogonal to a chordwise direction. The first and second angles α, θ may have a value between about five degrees and about 45 degrees. As shown in FIG. 9 , the first row 48 may include exhaust orifices 44 that alternate between being positioned at a first angle α and positioned at a second angle θ. The first angle α may be measured from the longitudinal axis 42 in a first direction, as indicated by an arrow on FIG. 9 for the first angle α, in a plane generally orthogonal to a chordwise direction. The second angle θ may be measured from the longitudinal axis 42 in a second direction, as indicated by an arrow on FIG. 9 for the second angle θ, in a plane generally orthogonal to a chordwise direction. In at least one embodiment, the first and second angles α, θ have equal or substantially equal values. In other embodiments, the first and second angles α, θ have different values.
As shown in FIG. 9 , the first and second rows 48 , 50 of orifices 44 may be formed from orifices 44 alternating between first and second angles α, θ relative to the longitudinal axis 42 . In addition, the pattern of alternating orifices 44 in the first and second rows 48 , 50 may be coordinated between the rows. For instance, the orifices 44 forming the second row 50 may be in the same position as the orifices 44 forming the first row 48 , except that rather than being positioned side by side, the orifices 44 in the second row 50 may be offset orthogonal to the longitudinal axis 42 and offset along the longitudinal axis 42 . This same pattern may be extended to the third row 52 of orifices 44 and other rows as well.
The showerhead 46 may also be configured as shown in FIG. 10 . For instance, the showerhead 46 may include orifices 44 forming the first, second, and third rows 48 , 50 , 52 of which one or more of the rows may have the following pattern. For instance, the first row 48 may have an orifice 44 positioned at the first angle α relative to the longitudinal axis 42 , an orifice 44 positioned generally parallel to the longitudinal axis 42 , an orifice 44 positioned at the second angle θ relative to the longitudinal axis 42 , an orifice 44 positioned generally parallel to the longitudinal axis 42 , and an orifice 44 positioned at the first angle α relative to the longitudinal axis 42 . The orifices 44 , may be spaced from each other within the row 48 a distance of about three times the diameter of the orifices 44 . In another embodiment, as shown in FIG. 10 , the orifices 44 may be spaced closer in a configuration referred to as a high density showerhead 46 .
As shown in FIG. 11 , the showerhead 46 may be configured such that two rows may have an alternating pattern of orifices 44 . For instance, first and third rows 48 , 52 may have the same pattern of angled orifices 44 that are offset from each other in a direction orthogonal to the longitudinal axis 42 and offset from each other in a direction along the longitudinal axis. However, second row 50 may have a pattern of orifices 44 aligned at the first and second angles α, θ that are opposite from the first and third rows 48 , 52 . In this spirit, the showerhead 46 may have orifices 44 positioned in other patterns other than shown in FIGS. 5–11 . The patterns illustrated in FIGS. 5–11 are not mean to be limiting; rather, the patterns are mean to be illustrative of the patterns that may be created by placing the orifices 44 at the first and second angles α, θ. In at least one embodiment, adjacent rows 48 , 50 , 52 may each have different patterns of angluation of the orifices 42 forming the rows.
During operation, cooling gases, which may be air, is passed through the root 16 of the blade 12 . The cooling gases flow throughout the internal cooling channels 32 of the blade 12 and are exhausted at various locations on the blade 12 for film cooling. At least a portion of the cooling fluids are exhausted through the orifices 44 forming the showerhead 46 in the leading edge 34 . The cooling gases impede combustion gases flowing past the blade 12 from contacting the leading edge 34 .
The foregoing is provided for purposes of illustrating, explaining, and describing embodiments of this invention. Modifications and adaptations to these embodiments will be apparent to those skilled in the art and may be made without departing from the scope or spirit of this invention.
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A turbine blade for a turbine engine having an internal cooling system formed from at least one cavity for receiving cooling air from a turbine blade assembly, passing the cooling air through the internal cooling system, and expelling the cooling air through orifices in a leading edge forming a showerhead, orifices in a trailing edge and in other locations. The showerhead includes exhaust orifices extending at various angles relative to each other through an outer wall forming the turbine blade. The exhaust orifices may form rows of orifices that are offset generally orthogonally and generally parallel to a longitudinal axis of the blade. The exhaust orifices are configured to effectively cool the leading edge portion of the blade and to reduce the likelihood of cracking of the outer wall forming the leading edge.
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RELATED APPLICATIONS
[0001] This patent application is a continuation, and claims priority benefit with regard to all common subject matter, of earlier-filed U.S. patent application Ser. No. 15/134,148, filed on Apr. 20, 2016, and entitled “SYSTEM AND METHOD FOR IRRIGATION SYSTEM MANAGEMENT”. U.S. patent application Ser. No. 15/134,148 claims priority benefit with regard to all common subject matter of earlier-filed U.S. patent application Ser. No. 13/803,223, filed on Mar. 14, 2013, entitled “SYSTEM AND METHOD FOR IRRIGATION MANAGEMENT”, issued as U.S. Pat. No. 9,326,461 on May 3, 2016. The identified earlier filed non-provisional patent applications are hereby incorporated by reference in their entireties into the present application.
BACKGROUND
1. Field
[0002] Embodiments of the present invention relate to irrigation management systems. More particularly, embodiments of the present invention relate to irrigation management systems configured to automatically adapt to changes in water demand from irrigation distribution systems.
2. Related Art
[0003] Mobile irrigation systems such as pivot-type irrigation systems and lateral-move irrigation systems are connected to water pumps that pump water to the irrigation systems from a water source, such as a pond, river or aquifer. Such water pumps typically provide water to multiple irrigation systems simultaneously and may be located remotely from the irrigation systems. Each irrigation system operates at an optimum water pressure that depends on such factors as the type of crop, the number of sections in the irrigation system, and the number and type of sprinkler heads on the irrigation system.
[0004] Each water pump that supplies water to the irrigation systems can be adjusted to supply water at various output levels to meet the needs of the system or systems it supplies. A pump providing water to multiple irrigation systems, for example, typically needs to operate at a greater output level than a pump providing water to a single irrigation system. Pumps are adjusted by manually actuating valves or other control features at the pump station. The optimum water pressure for each irrigation system may change during use, such as where the angle or direction of incline of the irrigation system changes at is travels along the irrigated terrain. Additionally, the total demand for water may fluctuate, such as where one or more irrigation systems may begin or end operation during the normal course of use. In any of these situations, the water pressure at each irrigation system may deviate from the optimum water pressure and have a negative effect on the performance of the irrigation system.
SUMMARY
[0005] Embodiments of the present invention solve the above-described problems by providing an irrigation management system operable to monitor the water pressure in each of a plurality of irrigation systems and automatically adjust the production of a water pump associated with the irrigation systems to address fluctuations in the water pressure.
[0006] An irrigation management system in accordance with an embodiment of the invention comprises a mobile irrigation system, a water pump and a controller. The mobile irrigation system receives water from the water pump and disperses the water, and includes a water pressure sensor for generating water pressure data indicating water pressure in the irrigation system.
[0007] The controller is configured to receive the water pressure data generated by the water pressure sensor and to compare a target water pressure with the sensed water pressure data to determine a difference between the target water pressure and the sensed water pressure. The controller adjusts operation of the water pump to increase or decrease water pressure to the irrigation system in a manner that resolves the difference between the target water pressure and the sensed water pressure.
[0008] A method of managing an irrigation system in accordance with another embodiment of the invention comprises receiving water pressure data from each of a plurality of water pressure sensors, wherein each of the water pressure sensors is associated with a separate mobile irrigation system. For each of the mobile irrigation systems, a target water pressure associated with the irrigation system is compared with the water pressure data from the irrigation system to determine a difference between the target water pressure and the sensed water pressure.
[0009] The method further comprises determining if any of the irrigation systems has a negative water pressure deviation. A negative water pressure deviation occurs when the sensed water pressure of an irrigation system is less than the target water pressure for that system. If any of the irrigation systems has a negative pressure deviation in excess of a predetermined amount, an irrigation system with the greatest negative deviation is identified and operation of the pump is adjusted to increase water pressure to all of the plurality of irrigation systems in a manner that resolves the greatest negative deviation.
[0010] An irrigation management system in accordance with yet another embodiment of the invention comprises a pump station and a plurality of irrigation systems for receiving water from the pump station and dispersing the water. The pump station includes a water pump and a pump controller. The pump controller is configured to compare a target water pressure associated with each irrigation system with water pressure data from a water pressure sensor associated with the irrigation system to determine a difference between the target water pressure and the sensed water pressure and determines if any of the irrigation systems has a negative water pressure deviation. A negative water pressure deviation occurs when the sensed water pressure of an irrigation system is less than the target water pressure for that system.
[0011] If any of the irrigation systems has a negative water pressure deviation in excess of a predetermined amount, the pump controller identifies an irrigation system with the greatest negative water pressure deviation and adjusts operation of the pump to increase water pressure to the plurality of irrigation systems in a manner that resolves the greatest negative water pressure deviation.
[0012] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Other aspects and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments and the accompanying drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a perspective view of an exemplary pivot type irrigation system for use with an irrigation management system constructed in accordance with embodiments of the invention;
[0014] FIG. 2 is a perspective view of a fixed central pivot of the irrigation system of FIG. 1 ; and
[0015] FIG. 3 is a block diagram of an irrigation management system constructed in accordance with embodiments of the invention.
[0016] The drawing figures do not limit the present invention to the specific embodiments disclosed and described herein. The drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the invention.
DETAILED DESCRIPTION
[0017] The following detailed description references the accompanying drawings that illustrate specific embodiments in which the invention may be practiced. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized and changes can be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense. The scope of the present invention is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled.
[0018] In this description, references to “one embodiment”, “an embodiment”, or “embodiments” mean that the feature or features being referred to are included in at least one embodiment of the technology. Separate references to “one embodiment”, “an embodiment”, or “embodiments” in this description do not necessarily refer to the same embodiment and are also not mutually exclusive unless so stated and/or except as will be readily apparent to those skilled in the art from the description. For example, a feature, structure, act, etc. described in one embodiment may also be included in other embodiments, but is not necessarily included. Thus, the present technology can include a variety of combinations and/or integrations of the embodiments described herein.
[0019] Turning now to the drawing figures, and initially FIGS. 1 and 2 , an exemplary irrigation system 10 is illustrated that may be used in accordance with embodiments of the invention. The illustrated irrigation system 10 is a central pivot irrigation system that broadly comprises a fixed central pivot 12 and a main section 14 pivotally connected to the central pivot 12 . The irrigation system 10 may also comprise an extension arm (also commonly referred to as a “swing arm” or “corner arm”) pivotally connected to the free end of the main section.
[0020] The fixed central pivot 12 may be a tower or any other support structure about which the main section 14 may pivot. The central pivot 12 has access to a well, water tank, or other source of water and may also be coupled with a tank or other source of agricultural products to inject fertilizers, pesticides and/or other chemicals into the water for application during irrigation.
[0021] The main section 14 may comprise a number of mobile support towers 16 A-D, the outermost 16 D of which is referred to herein as an “end tower”. The support towers are connected to the fixed central pivot 12 and to one another by truss sections 18 A-D or other supports to form a number of interconnected spans. The irrigation system 10 illustrated in FIG. 1 includes four mobile support towers 16 A-D; however, it may comprise any number of mobile support towers without departing from the scope of the present invention.
[0022] Each mobile tower may include a drive tube 20 A-D on which a pair of wheel assemblies 22 A-D is mounted. A drive motor 24 A-D is mounted to each drive tube 20 A-D for driving the wheel assemblies 22 A-D. The motors 24 A-D may include integral or external relays so they may be turned on, off, and reversed. The motors may also have several speeds or be equipped with variable speed drives.
[0023] Each of the truss sections 18 A-D carries or otherwise supports a conduit section 26 A-D or other fluid distribution mechanism that is connected in fluid communication with all other conduit sections. A plurality of sprinkler heads, spray guns, drop nozzles, or other fluid-emitting devices are spaced along the conduit sections 26 A-D to apply water and/or other fluids to an area beneath the irrigation system.
[0024] The irrigation system 10 may also include an optional extension arm (not shown) pivotally connected to the end tower 16 D and supported by a swing tower with steerable wheels driven by a motor. The extension arm may be joined to the end tower by an articulating pivot joint. The extension arm is folded inward relative to the end tower when it is not irrigating a corner of a field and may be pivoted outwardly away from the end tower while irrigating the corners of a field.
[0025] The irrigation system 10 may also include one or more high pressure sprayers or end guns 28 mounted to the end tower 16 D or to the end of the extension arm. The end guns 28 may be activated at the corners of a field or other designated areas to increase the amount of land that can be irrigated.
[0026] The irrigation system 10 includes a system controller 30 and a water pressure sensor 32 in communication with the system controller 30 . The system controller 30 is preferably mounted on the tower 12 to provide easy user access. The system controller 30 includes a computing component and other components for use with the computing component, including power components such as batteries, user interface components, and communications components for communicating with the drive motors 24 A-D and/or remote communications equipment, such as a cellular phone network or other wireless network. The system controller 30 may be encased in a waterproof housing or otherwise sealed from the environment to protect electrical components that may be damaged by water, dust or sunlight.
[0027] The water pressure sensor 32 is configured to measure the pressure of water in the irrigation system 10 and to communicate water pressure information to the controller 30 . The water pressure sensor 32 may include a pressure transducer that extends through a wall of a pipe section or conduit on which it is mounted and is exposed to the water inside the pipe section. The sensor 32 may include one or more wires (not illustrated) electrically connecting the sensor 32 and the controller 30 and configured to transfer the water pressure information from the sensor 32 to the controller 30 . Alternatively, the sensor 32 and the controller 30 may be configured to communicate wirelessly. It will be appreciated by those skilled in the art that various methods and means may be used to measure the water pressure and communicate the water pressure information from the sensor 32 to the controller 30 without departing from the spirit or scope of the present invention.
[0028] An irrigation management system 34 embodying principles of the present invention is illustrated in FIG. 3 . The irrigation management system 34 includes a pump station 36 , a plurality of irrigation systems 38 associated with the pump station 36 , and a control system 40 for managing operation of the pump station 36 and the irrigation systems 38 .
[0029] The pump station 36 pumps water from a water source (not shown) to the plurality of irrigation systems 38 via a system of water conduits, such as underground pipes. The pump station 36 may be located proximate the water source, such as a pond, river or aquifer and may be conventional in nature. The pump station 36 includes one or more water pumps 42 and may include a pump station controller 44 for controlling the one or more water pumps 42 . Among other things, the pump station controller 44 monitors water production and adjusts operation of the one or more pumps 44 so that the water production matches a predetermined level or “setpoint.” By way of example, the pump station water production may be set to a predetermined output water pressure wherein the controller 44 monitors the output water pressure and adjusts operation of the one or more pumps 42 in response to fluctuations in the water pressure.
[0030] Each of the irrigation systems 38 a - d may be similar to the irrigation system 10 described above, and each may include an irrigation system controller 46 a - d and a water pressure sensor 48 a - d that may be similar or identical to the controller 30 and sensor 32 described above in both form and function. The irrigation system controllers 46 may process the water pressure data, communicate the water pressure data to the control system 40 , or both. By way of example, each irrigation system controller 46 may determine whether the water pressure at the respective irrigation system has deviated from a target water pressure by a predetermined amount and, if so, communicate the water pressure information to the control system 40 .
[0031] The number of irrigation systems 38 associated with the pump station 36 may vary from one embodiment of the invention to another. In some embodiments, a single irrigation system 38 may be associated with the pump station 36 . In other embodiments, multiple irrigation systems 38 may be associated with the pump station 36 . Furthermore, the number of operating irrigation systems 38 associated with a single pump station 36 may change over time as new irrigation systems are assembled and connected to the pump station 36 , as existing irrigation systems are removed, and as existing irrigation systems begin operations and end operations during the normal course of use. Irrigation systems 38 may begin or end operations for various reasons, including for scheduled starts and stops or for repairs or maintenance. The irrigation systems 38 may be located relatively close to the pump station 36 , such as within several hundred feet or less, or may be located a relatively large distance from the pump station 36 , such as a mile or more.
[0032] Each of the irrigation systems 38 has a target operating water pressure associated with it. The target water pressure is the preferred or ideal water pressure associated with that particular system 38 and depends on various factors, including manufacturer recommendations, the overall size and distribution capacity of the system 38 , the speed at which the irrigation system 38 travels, the crop being irrigated by the system 38 , and the nature of the sprinkler heads. The target water pressure for each irrigation system 38 is preferably submitted to the control system 40 by a user, and may be submitted via the control system user interface 50 , via the irrigation system controllers 46 , or both. The control system 40 stores the target water pressure associated with each irrigation system 38 for use in managing the output of the pump station 36 , as explained below in greater detail. The target water pressure may be stored in each irrigation system controller 46 , remotely in the control system 40 , or both.
[0033] The control system 40 includes one or more computers or controllers in communication with the pump station controller 44 and with each of the irrigation system controllers 46 . The control system computers may be located remotely from the pump station 36 and the irrigation systems 38 and may manage more than one pump station 36 and associated irrigation systems 38 . The control system computers may be in communication with the pump station controller 44 and the irrigation system controllers 46 via a cellular wireless network or other wireless technology.
[0034] The control system 40 is operable to automatically adjust operation of the pump station 36 such that the irrigation systems 38 operate at or near their target water pressure. As explained above, the pump station water production is regulated by the pump station controller 44 such that the pump station production matches a predetermined setpoint. Due to variables in the operation of the various irrigation systems 38 a - d , however, the setpoint may need to be adjusted during operation to ensure that the irrigation systems 38 a - d operate at or near the target water pressure. Such operational variables may include changes in the position of each irrigation system including whether it is on relatively level terrain or is on inclined terrain, the addition of a new irrigation system, and existing systems beginning and ending irrigation operations. As the various irrigation systems 38 a - d go through these changes, all of the irrigation systems 38 a - d may be affected such that the pressure in each system may fluctuate. It may be necessary to adjust the pump station production to respond to these fluctuations.
[0035] The control system 40 may manage operation of the pump station 36 when the pump station 36 is supplying water to a single irrigation system or when the pump station 36 is supplying water to multiple irrigation systems. The number of irrigation systems 38 supplied by the pump station 36 may change during use as some of the irrigation systems 38 begin irrigation runs and others end irrigation runs during the normal course of operation. In the exemplary system illustrated in FIG. 3 , the pump station 36 is associated with four irrigation systems 38 a - d . During the course of use, all of the irrigation systems 38 a - d may be in operation simultaneously or any subset of the four may be operating. If three of the four irrigation systems 38 a - d are between programmed irrigation runs and not operating, for example, the pump station 36 may be supplying water to only one irrigation system. The control system 40 may manage operation of the pump station 36 differently if the pump station 36 is supplying a single irrigation system versus if the pump station is supplying multiple irrigation systems 38 a - d.
[0036] If the pump station 36 is supplying a single irrigation system 38 , it may operate as follows. The irrigation system water pressure sensor 48 monitors the water pressure in the irrigation system 38 and communicates the water pressure value to the irrigation system controller 46 . The irrigation system controller 46 communicates the water pressure to the control system 40 , which compares the actual water pressure measured by the sensor 48 with the target water pressure associated with the irrigation system 38 to determine if there is a difference or deviation between the actual water pressure and the target water pressure. A water pressure deviation may result from the actual water pressure being either greater than (a positive deviation) or less than (a negative deviation) the target water pressure.
[0037] If the control system 40 determines that there is a water pressure deviation, the control system 40 causes the pump station 36 to adjust operations to resolve the deviation. This may involve, for example, the control system 40 communicating the water pressure difference to the pump station controller 44 which in turn actuates the pump 42 to increase or decrease water production so that the actual water pressure measured at the irrigation system 38 is equal to or approximately equal to the target water pressure associated with the irrigation system 38 .
[0038] The control system 40 and/or the pump station 36 may resolve the water pressure deviation if any difference is detected, or may resolve the deviation only when the difference exceeds a predetermined amount or threshold. The predetermined amount or threshold may be between one percent and ten percent of the target pressure, more preferably between two percent and five percent of the target pressure. In terms of actual water pressure, the predetermined amount may be between 0.5 psi and 20 psi, more preferably between 2 psi and 10 psi.
[0039] Additionally, the control system 40 and/or the pump station 36 may resolve the deviation differently according to whether the deviation is positive or negative. The control system 40 and/or the pump station 36 may resolve any negative deviation regardless of magnitude, for example, but may only resolve a positive deviation that exceeds a predetermined threshold, as explained above. Similarly, the control system 40 and/or the pump station 36 may resolve negative deviations that exceed a small threshold and resolve positive deviations that exceed a large threshold, or vice versa.
[0040] If the pump station 36 is supplying water to more than one irrigation system 38 the process may be different, with the focus on ensuring all of the irrigation systems 38 in operation are operating at or above their respective target water pressures. The water pressure sensors 48 a - d associated with each of the operating irrigation systems 38 a - d generates water pressure data and communicates the water pressure data to the respective irrigation system controller 46 a - d , which then communicates the actual water pressure to the control system 40 . The control system 40 compares the water pressure data received from each irrigation system 38 with the target water pressure associate with the respective irrigation system 38 . If one or more of the irrigation systems 38 a - d is not operating, the controller 46 associated with the non-operating irrigation systems does not communicate water pressure data to the control system 40 , and the control system 40 does not include an actual water pressure or a target water pressure associated with the non-operating irrigation systems in its calculations.
[0041] The control system 40 first determines if a negative deviation (an actual water pressure that is less than the target water pressure) exists at one or more of the operating irrigation systems 38 . If the control system 40 determines that one or more of the irrigation systems 38 is operating at a negative water pressure deviation, it determines which of the systems 38 is operating at the greatest negative water pressure deviation. The control system 40 then adjusts operation of the pump station 36 to resolve the greatest negative deviation by increasing water production of the pump station 36 . The increased production increases pressure in all of the irrigation systems 38 until the greatest negative deviation is resolved. This may result in one or more of the irrigation systems 38 operating at a water pressure that is greater than the target water pressure (i.e., a “positive deviation”). Operating some of the irrigation systems 38 at a positive deviation is generally preferable to operating some of the irrigation systems 38 at a negative deviation because overwatering is typically less harmful to crop production than underwatering.
[0042] If the control system 40 determines that none of the irrigation systems 38 is operating at a negative water pressure deviation, it then determines whether the irrigation systems 38 are operating at a positive water pressure deviation. If so, the control system 40 adjusts operation of the pump station 36 to resolve the positive water pressure deviation without causing any of the irrigation systems 38 to operate at a negative water pressure deviation. To do this, the control system 40 determines which of the irrigation systems 38 is operating at the smallest positive water pressure deviation and adjusts operation of the pump station 36 to resolve the smallest positive water pressure deviation. Resolving the smallest water pressure deviation results in decreased water pressure at all of the irrigation systems 38 without resulting in any negative water pressure deviation.
[0043] As used herein, “resolving” a water pressure deviation means adjusting operation of the pump station 36 such that the water pressure deviation is less than a pre-determined amount. The control system 40 , the controller 44 , or both may be configured to resolve water pressure deviations in a predetermined period of time, such as within twenty minutes, fifteen minutes, ten minutes, five minutes or one minute. The control system 40 and/or the controller 44 may accomplish this by, for example, comparing the deviation to the pre-determined period of time to determine a rate at which the output should be adjusted upward or downwards. If the control system 40 identifies a positive deviation of five psi, for example, and the pre-determined period of time is five minutes, the control system 40 may command the controller 44 to adjust the water production downward at a rate of one psi per minute. Similarly, if the control system 40 identifies a negative deviation of five psi and the pre-determined period of time is ten minutes, the control system 40 may instruct the controller 44 to adjust the water production upward at a rate of one-half psi per minute. The rate may be determined by either the controls system 40 or the controller 36 .
[0044] The control system 40 is configured to operate the pump station 36 within the bounds of a maximum setpoint and a minimum setpoint to prevent runaway pressure changes. By way of example, if one of the irrigation systems 38 becomes ruptured and is unable to maintain water pressure, the control system 40 may detect the loss in pressure and attempt to compensate for the lost pressure by increasing water production at the pump station 36 . A maximum setpoint would allow the production of the pump station 36 to increase only to a predetermined threshold. Upon reaching the setpoint the control system 40 may cause production to remain constant or may shut down the pump station 36 and alert a user that there is a malfunction.
[0045] Although the invention has been described with reference to the exemplary embodiments illustrated in the attached drawings, it is noted that equivalents may be employed and substitutions made herein without departing from the scope of the invention as recited in the claims. For example, the water pressure sensor 32 may be mounted at any of various locations on the irrigation system 10 , including at or near the central pivot 12 (as illustrated) or on any of the various sections of the irrigation system 10 . Furthermore, the functionality of the irrigation system controller 30 , the pump station controller 44 , or both may be implemented remotely from the irrigation system 10 and the pump station 36 , such as in the control system 40 .
[0046] Having thus described various embodiments of the invention, what is claimed as new and desired to be protected by Letters Patent includes the following:
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An irrigation management system includes a water pump, at least one mobile irrigation system, and a pump controller. The mobile irrigation system includes a water pressure sensor for generating water pressure data indicating water pressure in the irrigation system. The pump controller is configured to receive the water pressure data generated by the water pressure sensor, to compare a target water pressure with the sensed water pressure data to determine a difference between the target water pressure and the sensed water pressure, and to adjust operation of the water pump to increase or decrease water pressure to the irrigation system in a manner that resolves the difference between the target water pressure and the sensed water pressure.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 12/906,878, filed Oct. 18, 2010, which is a divisional of U.S. application Ser. No. 11/750,282, filed on May 17, 2007, which is a continuation of U.S. application Ser. No. 10/270,272, filed on Oct. 10, 2002, which claims the benefit of U.S. provisional patent application Ser. No. 60/328,487 for “Server For Geospatially Organized Flat File Data,” filed Oct. 10, 2001, the disclosures of which applications are incorporated herein by reference.
FIELD OF THE DISCLOSURE
[0002] The present invention is related to organization and processing of flat file data, and more particularly to systems, methods, and computer program products for delivering content from several flat file databases that can reside locally and/or remotely.
BACKGROUND
[0003] Conventionally, stored data on a server is organized according to a plurality of files in a file system. In an application for storing, retrieving, and drawing geospatially organized data (such as an interactive viewer for geospatial data), each node may use a separate file for each drawable, with the various files being organized in a hierarchy of directories. Data representing imagery can be stored in basically the same way, possibly with different directory hierarchy and file naming protocols (for example, the clipgen format). Quadtree packets, which are the data files that are sent to the client that describe the quadtree structure and contents of the database, are computed beforehand and stored as files on the server. If a large amount of data is to be managed, creation and storage of such a database can overload a conventional file system. In order to mitigate the strain on the file system, a special output format may be employed to transfer the files. Even with such an arrangement, large amounts of data can result in corruption of the file system.
SUMMARY
[0004] In order to avoid the excessive transfer time and inefficiency of using a conventional file system, the present invention employs a flat file data organization technique, referred to herein as “Keyhole Flatfile,” or KFF, for storing and retrieving geospatially organized data. KFF reduces transfer time by transferring a few large files in lieu of a large number of small files. It also moves the process of locating a given data file away from the file system to a proprietary code base. Finally, KFF makes database management much easier by having the quadtree packets generated on demand. Items can be added to the database by simply inserting the files rather than inserting and regenerating the appropriate quadtree packets. Keyhole Flatfile assumes very low cache coherency, to account for the fact that in an application such as a geospatial data viewer, users might be looking at multiple different places on the globe, so that requests are likely to hit disparate parts of database and not just one location. Given this scenario, it is beneficial to minimize disk seeks. The indexing system of Keyhole Flatfile is a quadtree-based structure, wherein each node points to a location in a binary file that contains the data files.
[0005] In practice, the Keyhole Flatfile system has actually benefited significantly from the caching of the file system. Since it was designed for the worst-case scenario, it performs better than expected during normal access to the server. A memory caching system may be employed in conjunction with Keyhole Flatfile, if desired. Performance may be further improved by adding more memory to the server.
[0006] Keyhole Flatfiles may be accessed directly over the Internet by applications such as Earthviewer 3D and Earthviewer PocketPC. Earthviewer HTML viewer accesses the data directly on the server and delivers the rendered image to the web browser.
[0007] The present invention uses a quadtree index not only to help find data objects within a massive database, but also for fast delivery of the quadtree index itself to a re-mote application. This is accomplished by a four-level sectioning of the quadtree index, which allows for the quadtree packets to be generated with a minimal amount of reads from disk. The invention further provides the ability to quickly merge quadtree packets on the fly, thus allowing delivery of multiple databases without requiring that they be preprocessed into one database. Such functionality has benefits in the management of the database and for rapid deployment of new data.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a flow chart of KFF data retrieval according to one embodiment of the present invention.
[0009] FIG. 1A is a legend for various Figures of the present application.
[0010] FIG. 2 is a flow chart of QuadTree packet generation according to one embodiment of the present invention.
[0011] FIG. 3 is a flow chart of QuadTree packet merging according to one embodiment of the present invention.
[0012] FIG. 4 is a flow chart of obtaining a session key according to one embodiment of the present invention.
[0013] FIG. 5 is a flow chart of using a session key with a data packet according to one embodiment of the present invention.
[0014] FIG. 6 is a flow chart of general data migration according to one embodiment of the present invention.
[0015] FIG. 7 is a flow chart of the basic system flow according to one embodiment of the present invention.
[0016] FIG. 8 is a diagram showing a QuadTree packet and data file list according to one embodiment of the present invention.
[0017] FIG. 9 is a diagram showing a QuadTree-based approach to spatially organize data according to one embodiment of the present invention.
[0018] FIG. 10 is a diagram showing a data section according to one embodiment of the present invention.
[0019] FIG. 11 is a diagram showing a basetree structure according to one embodiment of the present invention.
[0020] FIG. 12 is a diagram showing a subtree structure according to one embodiment of the present invention.
DETAILED DESCRIPTION
Definitions
[0021] EarthServer DataStream—A server employing the techniques of the present invention.
[0022] Earthviewer 3D—A client application for viewing data provided via EarthServer DataStream.
[0023] Earthviewer PocketPC—A client application for viewing data provided via EarthServer DataStream.
[0024] Earthviewer HTML—An HTML-based viewer for viewing data provided via EarthServer DataStream.
[0025] Keyhole Binary File (KBF)—A file containing drawable packets that are concatenated one after another with a header describing where it should go in the database attached to the front of each packet.
[0026] Keyhole Flat File (KFF)—A file containing a set of data packets that are spatially indexed. It is the primary data format for EarthServer DataStream.
[0027] Raw Flat File (FF)—A file containing imagery or terrain tiles that are concatenated one after another with a header describing where it should go in the database attached to the front of each tile.
[0028] dbRoot—A file containing the version and channel information of a given KFFDB. It is used in deployment of a KFFDB to the EarthViewer 3D client.
[0029] QuadTree Packet—The QuadTree packet contains a set of nodes organized in recursive order describing the contents of the database at those specific nodes. This is the data packet that is sent to the EarthViewer 3D client to tell it what is contained in the KFFDB database.
[0030] Drawable Packet—This packet contains a set of drawables that can include, etSite (labeled points), etStreet (labled lines for drawing streets), and etPolyLines (multipoint line). These packets are associated with a particular node in the QuadTree and are sent to the client in order to draw such things as roads, points of interest, and state borders.
[0031] Image Tile—This is a one section of imagery at a particular resolution and position (i.e. a particular point in the QuadTree).
[0032] Terrain Tile—This is a one section of the terrain at a particular resolution and position (i.e. a particular point in the QuadTree).
[0033] System Architecture
[0034] Referring now to FIG. 7 , the basic flow of the EarthServer DataStream product consists of first taking the customer's data 701 and converting it via a data migration tool 702 into a Keyhole Flatfile Database (KFFDB) 703 . This KFFDB is then transferred over to EarthServer DataStream server 704 and its contents are then delivered to the Earthviewer products (such as Earthviewer 3D 705 and/or Earthviewer HTML 706 ) over the Internet.
[0035] Data Migration
[0036] Referring now to FIG. 6 , there is shown a flowchart of data migration as performed by data migration tool 702 according to one embodiment of the present invention. Tool 702 gets 602 a data item from list 601 of data items, and adds 603 the data item to QuadTree structure 605 . If, in 604 , there are more data items in list 601 , tool 702 returns to step 602 . Otherwise, it proceeds with steps 606 through 610 . Tool 702 gets 606 a node from QuadTree structure 605 and gets 607 data items in the node. It then creates 608 a data packet for the data items and puts 609 the data packet into Keyhole Flatfile database 703 . If, in 610 , there are more nodes in QuadTree structure 605 , tool 702 returns to step 606 . Otherwise the data migration process is complete.
[0037] Keyhole Flat File Database
[0038] The KFFDB 703 can come in two forms. One is a Keyhole Flatfile (KFF) and the other is a combination of a KFF and a set of Keyhole Binary Files (KBF).
[0039] There are three main parts to the a KFF file:
Data 1000 BaseTree 1100 SubTree 1200
[0043] Referring now to FIG. 8 , there is shown an example of a QuadTree packet 801 and data file list 802 according to one embodiment of the present invention. Referring also to FIGS. 10 , 11 , and 12 , there are shown examples of structures for data section 1000 , BaseTree 1100 , and SubTree 1200 respectively. The data section 1000 contains the data files 1001 that are inserted into the KFF. The BaseTree 1100 contains all the nodes 1101 A at the base of the tree, which are all nodes 1101 A that reside on the first 12 levels. The SubTree contains all the nodes 1101 B below the base of the tree. The nodes 1101 of the QuadTree packet 801 are stored in four-level packets; each packet has an associated list of data file names and locations. Each node 1101 indexes into that list to store the data file names and locations that are associated with that particular node 1101 . The list of data file names and locations is stored in the data section 1000 .
[0044] In one embodiment, the data section 1000 holds data files 1001 and QuadTreeFileLists, the BaseTree section 1100 holds QuadTreeIndexSections 1101 A for the first 12 levels of the QuadTreeIndex, and the SubTree section 1200 holds QuadTreeIndexSections 1101 B for the levels below level 12 of the QuadTreeIndex. Each section includes a set of files.
[0045] In the KFF, file space of deleted files is left unused. Therefore, over time with deletions and additions into the KFF, the data file can become fragmented. In the case of replaced files, the space is reused if the new file is less than or equal to the size of the old file. By storing QuadTree packet data file lists 802 in the data section, the invention allows base 1100 and SubTree 1200 sections to remain unfragmented, since QuadTree packets are atomic units (i.e., space for all 85 nodes are allocated when a QuadTree packet is created) while data file lists 802 can change in size.
[0046] Given the case where the data files 1001 are inserted into the KFF, the KFF can stand alone as a KFFDB 703 for the EarthServer DataStream.
[0047] The second form of the KFFDB 703 includes a KBF. In this case, the KFF is used as an index file into the KBF, which acts as the source for all of the data files. In one embodiment, the KBF file is used only with drawable packets (such as streets, polylines, sites, and the like), while the FF file format is used for imagery and terrain tiles. The KBF/KFF form of the KFFDB 703 may be used for maintaining large KFFDBs 703 such as the Earthserver ASP database, since it allows for small incremental updates to the database rather than a completely new KFFDB 703 .
[0048] In one embodiment, KFFDB 703 is implemented using the following files. For a KFFDB 703 called “kffdb.sample”, files might include:
kffdb.sample kffdb.sample.1 kffdb.sample.2 kffdb.sample.base kffdb.sample.sub kffdb.sample.sub.1
[0055] The data section 1000 is the first three files (kffdb.sample, kffdb.sample.1, and kffdb.sample.2); the BaseTree section 1100 is in the fourth file (kffdb.sample.base), and the SubTree section 1200 is in the last two files (kffdb.sample.sub and kffdb.sample.sub.1). In this embodiment, each section is split up into a series of files of predetermined size (such as one gigabyte, for example). Numbered file names such as kffdb.sample.1 and kffdb.sample.2 represent the split files. In this embodiment, the collection of these six files would be the KFF.
[0056] For the KBF/KFF form, in one embodiment the implementation would consist of the following files. For a KFFDB 703 called “kffdb.sample”, files might include:
kffdb.sample kffdb.sample.base kffdb. sample. sub kffdb. sample. subl restaurantdata.kbf streetdata.kbf imagerydata.ff
[0064] The first four files (kffdb.sample, kffdb.sample.base, kffdb.sample.sub, and kffdb.sample.subl) are the KFF that acts as the index into the last three files (restaurantdata.kbf, streetdata.kbf, and imagerydata.ff), which contain data such as streets, points, lines, imagery and terrain. The last three files do not require the .kbf/ff extension.
EarthServer DataStream Server
[0065] In one embodiment, the EarthServer DataStream Server includes the following components:
KFFDB 703 dbRoot Apache modules
mod_flatfile mod_earthrender mod_dbrootmerger
[0072] KFFDB 703 is the database that is to be delivered by the server. dbRoot maintains the version and content information of the KFFDB 703 . The Apache modules deliver the contents of the KFFDB 703 .
[0073] KFFDB 703
[0074] The EarthServer DataStream server can merge multiple KFFDBs 703 in addition to multiple remote databases. The local databases are directly attached and the re-mote databases are accessed via the mod_flatfile HTTP interface. In one embodiment, mod_flatfile allows ten local databases and ten remote databases to be merged, although in other embodiments additional databases may be merged. In one embodiment, EarthServer DataStream allows for one remote database to be merged—specifically, the Earthserver ASP. In alternative embodiments, any number of databases can be merged together. In one embodiment, the mod_earthrender module can only have one remote database and up to ten local databases; in other embodiments, this module can include any number of databases.
[0075] dbRoot
[0076] The dbRoot file contains the current version of the KFFDB 703 . In one embodiment, dbRoot is the first thing that the Earthviewer 3D client asks for when it starts up so that it knows whether the data files it has in its cache are current or not. The dbRoot also contains information on what data is contained on each channel. It can potentially contain any other registry values that need to be set or changed in the Earthviewer 3D client, such as the domain name of the stream server, clip texture settings, and default values of buttons.
[0077] The dbRoot file also contains the encryption key that is used by the EarthServer DataStream Server to encrypt the content that is being delivered. The encryption key is also used by the client to decrypt the incoming data files.
[0078] In one embodiment, whenever the KFFDB 703 is changed on the server, the dbRoot version number must be incremented. If any additional channels of data have been added, in one embodiment they are recorded in the dbRoot file in order for the Earthviewer 3D client to be aware of their existence.
[0079] In one embodiment, the dbRoot file is created using the dbRoot tool. The channel information for a given KFFDB 703 is set by attaching a text file with the dbRoot. The text file in the ETA format takes the following form:
[0000]
<etStruct> [export.layers]
{
<etLayer> [Channel A]
{
“recreation”
0.0
128 true
“”
}
<etLayer > [Channel B]
}
“building”
0.0
129 true
“”
}
<etLayer> [Channel C]
}
“bang”
0.0
130 true
“”
}
}
[0080] For each entry in the list, the name of the channel is placed in the brackets [ ]. The first value in an entry is the type of icon to use in the “Show Me/Popular Locations” section of the Earthviewer 3D client. In one embodiment, the possible values for this are:
[0081] “american-flag”
[0082] “asian-flag”
[0083] “auto”
[0084] “auto-service”
[0085] “bang”
[0086] “bars”
[0087] “building”
[0088] “dining”
[0089] “fast-food”
[0090] “four-dollars”
[0091] “french-flag”
[0092] “italian-flag”
[0093] “mexican-flag”
[0094] “misc-dining”
[0095] “one-dollar”
[0096] “parks”
[0097] “recreation”
[0098] “three-dollars”
[0099] “transportation”
[0100] “two-dollars”
[0101] The second value is whether the channel is turned on (1.0) or off (0.0) by default. The third value is the channel number. The fourth value is whether the channel is to show up in the “Show Me/Popular Locations” list (true/false). The fifth value sets the channel to be triggered by a button on the Earthviewer 3D UI. The possible values are:
[0102] “borders”
[0103] “roads”
[0104] “terrain”
[0105] “weather”
[0106] Other values can also be set using the ETA file format.
[0107] mod_flatfile
[0108] This module delivers data files directly from the KFFDB 703 and generates QuadTree packets on demand for the KFFDB 703 . This is the main interface for Earthviewer 3D and Earthviewer PocketPC. Files are accessed by asking for the QuadTree node location described by a branching traversal guide (BTG) and the name of the file. Data packets just use a BTG. The URI formats for requesting these data objects are as follows:
[0109] Data Files:
[0000]
http://stream.earthviewer.com/flatfile?fl-<BTG>-<datafilename>
Example: http://stream.earthviewer.com/flatfile?f1-010302-i.1
Data File Name Formats:
image tiles:
i.<version>
terrain tiles:
t<version>
data files:
d.<channel>.>version>
[0110] QuadTree Packets:
[0000]
8-bit QuadTree Packets:
http://stream.earthviewer.com/flatfile?q1-<BTG>
16-bit QuadTree Packets:
http://stream.earthviewer.com/flatfile?q2-<BTG>
Example: http://stream.earthviewer.com/flatfile?q1-010302
mod earthrender
[0111] This module delivers image files for viewing the KFFDB 703 through an HTML interface. The following are the parameters for defining a desired image:
[0000]
lat,[float]
Sets the latitude of the center pixel of the image.
long=[float]
Sets the longitude of the center pixel of the image.
level,[int]
Sets the level to access the database.
xsize,[int]
Sets the width of the image.
ysize,[int]
Sets the height of the image.
clist4string]
Sets what channels to turn on in the image
(i.e. turn on 1, 3, 34 then string is 001003034)
plat=[float]
Sets the latitude of the annotation point.
plong=[float]
Sets the longitude of the annotatin point.
pname,[string]
Sets the label of the annotation point.
ypsearch,[string]
Sets the string to search for in the yp database.
filetype=[string]
Sets what type of file to return.
jpeg _ “jpg”
gif = “gif”
eta = “eta”
textnum,[int]
If value is 1 then sends over comma-delineated list
of
visible sites/POIs in the image.
mod dbrootmerger
[0112] This module delivers the dbRoot file. It also merges the dbRoot file with the dbRoot file of remote KFFDBs 703 so that when changes are made to remote KFFDBs 703 it is reflected as a change in the delivered database from the EarthServer DataStream Server. The delivered version number is computed by adding all of the version numbers of each dbRoot together, therefore if any of the dbRoots get upreved then the merged.
[0113] Session Key Verification and Access Control Layer Restrictions
[0114] The EarthServer DataStream works in conjunction with an authorization server that passes out session keys to registered users. The session keys are needed for two reasons: to validate the user and to restrict access to the database.
[0115] The validation is done both at the authorization server and the stream server. The authorization server only gives out session keys to registered users. These session keys have an expiration time that is checked by the stream servers, so old session keys can not be stolen and reused.
[0116] The session keys also contain additional information that tells the stream server which parts of the database a particular user is allowed to access. This is conveyed through the use of package IDs, where each package ID grants database access for a particular region, at a particular resolution, and for a particular channel (i.e. imagery, terrain, roads, restaurants, etc.).
[0117] System
[0118] In one embodiment, the present invention runs on a conventional computer, having components such as the following:
[0119] 1×866 MHz Pentium III
[0120] 512 MB Main Memory
[0121] 18 GB Hard Disk Space
[0122] In another embodiment, the present invention runs on a conventional computer, having components such as the following:
[0123] 2×1 GHz Pentium III
[0124] 1 GB Main Memory
[0125] 36 GB Hard Disk Space
[0126] In yet another embodiment, the present invention runs on a conventional computer, having components such as the following:
[0127] 2×1.26 GHz Pentium III
[0128] 2 GB Main Memory
[0129] 72 GB Hard Disk Space
[0130] One skilled in the art will recognize that many other types of hardware components may be used in connection with the present invention. Component characteristics may affect the performance of EarthServer DataStream (ESDS) as follows.
[0131] CPU: The processor speed mainly affects how fast ESDS can deliver earthrender images. A faster processor will allow for more images to be delivered per second. The main processor-heavy elements of mod_flatfile are encryption, compression, and QuadTree packet generation.
[0132] Memory: The amount of main memory helps tremendously in system caching of file blocks. This increases the speed at which data packets can be pulled out of the KFFDB 703 and therefore general performance of ESDS.
[0133] Hard Drive: The more disk space that is available, the more of the KFFDB 703 that can be cached on the local disk, and the fewer requests need to be made to the remote server (i.e. Earthserver ASP). In the case of an NFS-mounted NAS device, it could reduce need to access the NAS device by caching previously requested locally. Also for earthrender, the local drive can be used to cache decompressed image tiles, which can tremendously increase performance. The main factor that affects KFFDB 703 read performance is disk seek time, and disk seek time is directly related to rotational speed. Therefore higher rotational speed generally results in improved performance.
[0134] Module Directives
[0135] The following is a list of directives for each module. The directives with the * next to them are required directives and the others are optional. There is an explanation of each directive below along with an example of how to use them.
[0000]
mod flatfile
*KffFlatfileDatabasePath - a list of kff database paths
Example:
KffFlatfileDatabasePath /gaiadb/dbl/kffdb .dbl /gaiadb/db2/kffdb.db2
KffFlatfileDatabaseURL - a list of kff database URLs
Example:
KffFlatfileDatabaseURL stream.earthviewer.com stream.companyA.com
*KffDatabaseRootPath - the path for the dbRoot file
Example:
KffDatabaseRootPath /var/www/dbroot/dbRoot.verl
KffFlatfileLogFilePath - the path for flat file log
Example:
KffFlatfileLogFilePath /var/www/logs/kffdblog
KffFlatfileSessionCheckLevel - the session check level
(0—only valid cookie, 1—valid cookie or no cookie, 2—no restrictions)
Example:
KffFlatfileSessionCheckLevel 2
KffFlatfileBinaryLog - flag for using binary log
Example:
KffFlatfileBinaryLog On
KffFlatfileBinaryLog Off
KffFlatfileCacheFilePath - the path for cache file
Example:
KffFlatfileCacheFilePath /var/www/esds-cache/
KffFlatfileMaximumCacheSize - the maximum number of MB of the cache file
Example:
KffFlatfileMaximumCacheSize 1000
KffFlatfileACLDictionaryPath - the path for the ACL dictionary
Example:
KffFlatfileACLDictionaryPath /var/www/acl/ACL_dictl
KffFlatfileACLlndexPath - the path for the ACL index
Example:
KffFlatfileACLIndexPath /var/www/acl/ACL_index_l
KffFlatfileACLDefaultPolicyPath - the path for the ACL default policy
Example:
KffFlatfileACLDefaultPolicyPath /var/www/acl/ACL_defl
KffFlatfileACLMemoryResident - flag for whether the dictionary is memory res-
ident or not
Example:
KffFlatfileACLMemoryResident On
KffFlatfileACLMemoryResident Off
KffFlatfileCopyrightListPath - the path for the copyright list file
Example:
KffFlatfileCopyrightListPath /var/www/crlist/copyrightlist.crf
mod earthrender
*KffEarthrenderDatabasePath - a list of kff database paths
Example:
KffEarthrenderD atab as ePath /gaiadb/db 1 /kffdb .db 1 /gaiadb/db2/kffdb .db2
KffEarthrenderDatabaseURL - a list of kff database URLs
Example:
KffEarthrenderDatabaseURL stream.earthviewer.com
*KffTexturePath - the path for the texture image files
Example:
KffTexturePath /var/www/textures/
KffYPServerUr1Path - the url for the ypserver
Example:
KffYPServerUr1Path http://yp.earthviewer.com/cgi-
bin/ypsearch_beta?long=%lf&lat=%lf&dlat=%lf&dlong=%lf&name=%s
KffEarthrenderCheckLevel - the check level for access
(0—full access, 1—SF only, 2—ACL/SessionKey restricted access)
Example:
KffEarthrenderCheckLevel 2
KffEarthrenderACLDictionaryPath - the path for the ACL dictionary
Example:
KffEarthrenderACLDictionaryPath /var/www/acl/ACL_dict 1
KffEarthrenderACLlndexPath - the path for the ACL index
Example:
KffEarthrenderACLlndexPath /var/www/acl/ACL_index_l
KffEarthrenderACLDefaultPolicyPath - the path for the ACL default policy
Example:
KffEarthrenderACLDefaultPolicyPath /var/www/acl/ACL_defl
KffEarthrenderACLMemoryResident - flag for whether the dictionary is memory
resident or not
Example:
KffEarthrenderACLMemoryResident On
KffEarthrenderACLMemoryResident Off
KffEarthrenderCopyrightListPath - the path for the copyright list file
Example:
KffEarthrenderCopyrightListPath /var/www/crlist/copyrightlist.crf
mod_dbrootmerger
KffDbRootMergerURL - a list of kff database URLs
Example:
KffDbRootMergerURL stream.earthviewer.com
*KffDbRootMergerDbRootPath - the path for the dbRoot file
Example:
KffDbRootMergerDbRootPath /var/www/dbroot/dbRoot.verl
KffDbRootMergerPostambleMerge - flag for whether to merge the postambles
Example:
KffDbRootMergerPostambleMerge On
KffDbRootMergerPostambleMerge Off
[0136] Tools
[0137] smelter—This tool is used to convert customer data into kbf or kff files. It is the main tool used for data migration, as shown in FIG. 6 .
[0138] dbroottool—This tool is used to create the dbRoot file. It can read the contents of a dbRoot file, write out a new dbRoot file, or increment the version number of a dbRoot file.
[0139] kbftokff—This tool is used to add a kbf file into a kff file. This mainly pertains to drawables such as points and lines.
[0140] fftokff—This tool is used to add an ff file into a kff file. This mainly pertains to imagery and terrain.
[0141] kffperf—This is a tool to measure the performance of the EarthServer Data Stream. It takes a log file form the apache server and sends those requests to a given server.
[0142] kffview—This tool is used to view the contents of a kff file, just like traversing through directories on a unix file system.
[0143] kffreadlog—This tool is used to read the binary log file generated by the mod_flatfile module.
[0144] Libraries
[0145] kff—This library is used to create and modify kff files.
[0146] kbf—This is a header file that provides classes to create, read, and write kbf files.
[0147] qtpgen—This library is used to create/modify drawable packets and QuadTree packets
[0148] jpegbuffer—This library is used to create 2D representations (such as JPEG im ages) from the KFFDB 703 database
[0149] Methods
[0150] Referring now to FIGS. 1 through 6 , there are shown flow charts of various me-thods according to the present invention. The following components, associated with KFF, are used in the various methods as depicted in FIGS. 1 through 6 . Referring also to FIG. 1A , there is shown a legend indicating symbols for the various components de scribed below.
[0151] Data Packet
[0152] Summary: This is a collection of bytes that contain data about a geospecific area of the earth. This data can be of any type: imagery, terrain, vectors, points, etc.
[0153] QuadTreeIndexNode
[0154] Summary: This is one node of the QuadTreeIndex. The node contains two numbers, offset and length, which refers to a particular section of the QuadTreeFileList of the QuadTreeIndexSection associated with the node. This section contains the list of data packets that are associated with the node, where each item in the list tells the name of the data packet, the location of the data packet, and the size of the data packet.
[0155] QuadTreeFilePosition
[0156] Summary: This data item contains two numbers, data file index and data file offset, which are used to store the location of a particular data packet. The data file index tells which file it is contained in, and the data file offset tells where in that file the data packet is located.
[0157] QuadTreePosition
[0158] Summary: This data item contains a particular position of a node in the QuadTree by specifying the level of the node and a list of what child was traversed at each level.
[0159] QuadTreeFileEntry
[0160] Summary: This data item contains three things: name string, QuadTreePosition, and data packet size. These describe the name of the data packet, the location of the data packet, and the size of the data packet.
[0161] QuadTreeFileList
[0162] Summary: This data item is a set of QuadTreeFileEntries. It is associated with a QuadTreeIndexSection and it is the list of all the data packets that are contained within that particular QuadTreeIndexSection.
[0163] QuadTreeIndexSection
[0164] Summary: This data item is a four-level section of the QuadTreeIndex consisting of QuadTreeIndexNodes and an associated QuadTreeFileList. It also contains QuadTreePositions for all the children of the fourth-level nodes.
[0165] QuadTreeIndex
[0166] Summary: Referring now to FIG. 9 , there is shown the QuadTreeIndex indexing system to the KFF file that tells what is in the database and where in the database it resides. It uses a QuadTree-based approach to spatially organize the data. This means each node of the QuadTree has four children 902 A-C, where each child 902 covers one quarter of its parent's 901 defined area.
[0167] QuadTreeQuantum
[0168] Summary: This data item contains information about a particular node in the QuadTree that is delivered to the Earthviewer 3D client. This QuadTree is different from the QuadTreeIndex; the information in the node is specific to the Earthviewer 3D client. The node contains version numbers for imagery, terrain, cache node, and channels. It also contains children existence information.
[0169] QuadTreePacket
[0170] Summary: This data item includes a recursively ordered list of QuadTreeQuantums, which describes a section of the Earthviewer 3D client QuadTree.
[0171] KFF Data Retrieval
[0172] FIG. 1 is a flow chart of KFF data retrieval according to one embodiment of the present invention. The system gets 101 root QuadTreeIndexSection from KFF 703 and determines 103 whether QuadTreeIndexSection contains the node described by QuadTreePosition 102 . If not, the system gets 104 the next QuadTreeIndexSection from KFF 703 . If QuadTreeIndexSection does contain the node, the system gets 105 the QuadTreeIndexNode identified by the QuadTreePosition from the QuadTreeIndexSection, and gets 106 the QuadTreeFileList associated with the QuadTreeIndexSection from KFF 703 . Then, the system gets 107 the QuadTreeFileEntries from the QuadTreeFileList pointed to by the QuadTreeIndexNode and determines 109 whether Data Name 108 exists in the QuadTreeFileEntries.
[0173] If Data Name 108 does not exist in the QuadTreeFileEntries, the system returns 112 a returns 113 a “Data Packet Not Found.” If Data Name 108 does exist in the Qua dTreeFileEntries, the system gets 110 QuadTreeFilePosition and size of Data Name 108 Data Packet from QuadTreeFileEntry. The system then gets 111 Data Packet at Qua dTreePosition, and returns 113 a “Data Packet Found.”
[0174] QuadTree Packet Generation
[0175] FIG. 2 is a flow chart of QuadTree packet generation according to one embodi-ment of the present invention. The system gets 202 the QuadTreeIndexSection that in-cludes the QuadTreeIndexNode at the QuadTreePosition 201 from KFF 703 . The system then gets 203 the QuadTreeIndexNode identified by the QuadTreePosition 201 from the QuadTreeIndexSection, and gets 204 the QuadTreeFileList associated with the Qua dTreeIndexSection from KFF 703 . The system then gets 205 the QuadTreeFileEntries from the QuadTreeFileList pointed to by the QuadTreeIndexNode, and creates 206 a QuadTreeQuantum from the QuadTreeFileEntries.
[0176] The system then adds 209 the QuadTreeQuantum to the QuadTreeQuantum list 210 . Also, it determines 207 whether the children at the QuadTreePosition 201 extend beyond the QuadTreePacketDepth 208 . If not, the system determines 213 whether there is a first child at the QuadTreePosition 201 ; if so, it creates 214 a QuadTreePosition for the first child. The system determines 215 whether there is a second child at the Qua dTreePosition 201 ; if so, it creates 216 a QuadTreePosition for the second child. The system determines 217 whether there is a third child at the QuadTreePosition 201 ; if so, it creates 218 a QuadTreePosition for the third child. The system determines 219 whether there is a fourth child at the QuadTreePosition 201 ; if so, it creates 220 a QuadTreePosi tion for the fourth child.
[0177] The system then determines 211 whether this is the last QuadTreeIndexNode to be processed. If so, it creates 212 the QuadTreePacket 801 from the QuadTreeQuantum list 210 .
[0178] QuadTree Packet Merging
[0179] FIG. 3 is a flow chart of QuadTree packet merging according to one embodiment of the present invention. The system merges QuadTreePacket1 801 A and QuadTreePacket2 801 B as follows. It creates 301 A QuadTreeQuantumList1 210 A from QuadTreePacket1 801 A, and creates 301 B QuadTreeQuantumList2 210 B from QuadTreePacket2 801 B. The system then determines 302 whether there is another QuadTreeQuantum in List1 210 A. If not, the system determines 303 whether there is another QuadTreeQuantum in List2 210 B. If not, the system adds 304 QuadTreeQuantum2 to the merged QuadTreeQuantumList 210 C and creates 311 a merged QuadTreePacket 801 C.
[0180] If, in 303 , the system determines that there is another QuadTreeQuantum in List2 210 B, it proceeds directly to step 311 to create a merged QuadTreePacket 801 C.
[0181] If, in 302 , the system determines that there is another QuadTreeQuantum in List1 210 A, it gets 305 the first or next QuadTreeQuantum from List1 210 A, computes 306 the QuadTreePosition of the next QuadTreeQuantum in List1 210 A, and determines 307 whether there is another QuadTreeQuantum in List2 210 B. If not, the system adds 308 QuadTreeQuantum1 to the merged QuadTreeQuantumList 210 C and creates 311 a merged QuadTreePacket 801 C.
[0182] If, in 307 , the system determines that there is another QuadTreeQuantum in List2 210 B, it gets 309 the first or next QuadTreeQuantum from List2 210 B and computes 310 the QuadTreePosition of the next QuadTreeQuantum in List2 210 B. Then, it determines 311 whether the level of QuadTreePosition1 is less than, greater than, or equal to the level of QuadTreePosition2. If the level of QuadTreePosition1 is less than the level of QuadTreePosition2, the system puts back 317 QuadTreeQuantum2 into QuadTreeQuantumList2 210 B, adds 318 QuadTreeQuantum1 to the merged QuadTreeQuantumList 210 C and creates 311 a merged QuadTreePacket 801 C.
[0183] If, in 311 , the system determines that the level of QuadTreePosition1 is greater than the level of QuadTreePosition2, it puts back 315 QuadTreeQuantum1 into QuadTreeQuantumList1 210 A, adds 316 QuadTreeQuantum2 to the merged QuadTreeQuan tumList 210 C and creates 311 a merged QuadTreePacket 801 C. It also returns to step 302 .
[0184] If, in 311 , the system determines that the level of QuadTreePosition1 is equal to the level of QuadTreePosition2, it determines 312 whether the child number of Qua dTreePosition1 is less than, greater than, or equal to the child number of QuadTreePosi tion2. If the child number of QuadTreePosition1 is less than the child number of Qua dTreePosition2, the system puts back 315 QuadTreeQuantum1 into QuadTreeQuantumL ist1 210 A, adds 316 QuadTreeQuantum2 to the merged QuadTreeQuantumList 210 C and creates 311 a merged QuadTreePacket 801 C. It also returns to step 302 . If, in 312 , the child number of QuadTreePosition1 is greater than the child number of QuadTreePosition2, the system puts back 317 QuadTreeQuantum2 into QuadTreeQuantumList2 210 B, adds 318 QuadTreeQuantum1 to the merged QuadTreeQuantumList 210 C and creates 311 a merged QuadTreePacket 801 C. If, in 312 , the child number of QuadTreePosition1 is equal to the child number of QuadTreePosition2, the system merges 303 the QuadTreeQuantums together, puts 314 the merged QuadTreeQuantum into the merged QuadTreeQuantumList 210 C, and creates 311 a merged QuadTreePacket 801 C. It also returns to step 302 .
[0185] Obtaining a Session Key
[0186] FIG. 4 is a flow chart of obtaining a session key according to one embodiment of the present invention. The system determines 401 whether the user has registered the client application. If not, it gets 402 the first name, last name, and registration ID from the user. Next, the system gets 403 the encryption key from the server. Next, it encrypts 404 the first name, last name, and registration ID, and sends 405 the encrypted message to the server for verification. If the server indicates 406 that the registration ID is not valid, the system exits 407 .
[0187] If, in 406 , the server indicates that the registration ID is valid, or if, in 401 , the system determines that the user has registered the client application, the system sends 408 the encrypted registration ID and requests a session key.
[0188] The system then determines 409 whether the registration ID is valid. If so, it sends 411 a session key back to the client. If not, the system exits 410 .
[0189] Using a Session Key
[0190] FIG. 5 is a flow chart of using a session key with a data packet according to one embodiment of the present invention. The system sends 501 the session key with a data packet request to the server. Next, it decrypts 502 the session key on the server side, and gets expiration time 502 , package IDs 503 , and current time 505 . The system then determines 506 whether the current time is past the expiration time. If so, it denies 507 access.
[0191] If the current time is not past the expiration time, the system determines 508 whether the data packet requested is accessible to the user given the list of package IDs. If not, it denies 509 access. If the data packet is accessible, the system sends 510 the re quested data packet.
[0192] In the above description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the invention. It will be apparent, however, to one skilled in the art that the invention can be practiced without these specific details. In other instances, structures and devices are shown in block diagram form in order to avoid obscuring the invention.
[0193] Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
[0194] Some portions of the detailed description are presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of steps leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.
[0195] It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the discussion, it is appreciated that throughout the description, discussions utilizing terms such as “processing” or “computing” or “calculating” or “determining” or “displaying” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system's memories or registers or other such information storage, transmission or display devices.
[0196] The present invention also relates to an apparatus for performing the operations herein. This apparatus may be specially constructed for the required purposes, or it may comprise a general-purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable storage medium, such as, but is not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, and magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs), EPROMs, EEPROMs, magnetic or optical cards, or any type of media suitable for storing electronic instructions, and each coupled to a computer system bus.
[0197] The algorithms and displays presented herein are not inherently related to any particular computer, network of computers, or other apparatus. Various general-purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct a more specialized apparatus to perform the required method steps. The required structure for a variety of these systems appears from the description. In addition, the present invention is not described with reference to any particular programming language. It will be appreciated that a variety of programming lan-guages may be used to implement the teachings of the invention as described herein.
[0198] As will be understood by those familiar with the art, the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. For example, the particular architectures depicted above are merely exemplary of one implementation of the present invention. The functional elements and method steps described above are provided as illustrative examples of one technique for imple menting the invention; one skilled in the art will recognize that many other implementa tions are possible without departing from the present invention as recited in the claims. Likewise, the particular capitalization or naming of the modules, protocols, features, attributes, or any other aspect is not mandatory or significant, and the mechanisms that implement the invention or its features may have different names or formats. In addition, the present invention may be implemented as a method, process, user interface, computer program product, system, apparatus, or any combination thereof. Accordingly, the dis closure of the present invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.
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A flat file data organization technique is used for storing and retrieving geospatially organized data. The invention reduces transfer time by transferring a few large files in lieu of a large number of small files. It also moves the process of locating a given data file away from the file system to a proprietary code base. Additionally, the invention simplifies database management by having quadtree packets generated on demand.
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FIELD OF THE INVENTION
This invention is directed to a process and apparatus for preheating and inserting scrap into a smelting furnace for production of steel or the like, and more particularly, to a process and apparatus by which the scrap may be preheated using energy contained in furnace-waste gases, which energy comprises sensible heat and chemically bonded heat in combustible portions of the furnace-waste gases.
BACKGROUND OF THE INVENTION
In the increasingly competitive steel industry, minimizing the energy consumption of a mill is one of the most important goals. Lowered energy consumption at the mills could mean lower prices for the consumers or higher profit margins for the mill owners or, sometimes, the survival of the business enterprise involved.
Because of the tremendous amount of energy consumed by a mill, savings of a small fraction of the energy used can result in significant monetary gains. An area in which such energy savings may be achieved is in the preheating of scrap metal prior to its insertion into a smelting furnace. By preheating the scrap metal, the smelting furnace requires less energy input to produce the same amount of molten metal.
Various devices and processes have been disclosed for recycling the energy remaining in the furnace-waste gases from a smelting furnace for use in preheating scrap metal. This is typically implemented by combusting the furnace-waste gases and then channeling the hot combustion gas, or heating gas, to a receptacle to preheat the scrap metal contained therein.
In a device for preheating steel scrap disclosed in German patent publication DE-PS 31 33 447, a receptacle that is open at the top and has a base cover which is selectively openable is inserted in a pit. A hood connected to a waste-gas line is fastened to an opening of the receptacle in a gas-tight manner. Hot waste gases are guided into the receptacle from the hood and through the receptacle from top to bottom, thus preheating the scrap contained therein. After the scrap is preheated, the waste gases are guided through an opening provided in the base cover.
In a further development of this concept, German patent publication DE-PS 33 07 400 discloses a preheating apparatus in which hot waste gases are guided axially through a waste gas line from top to bottom through a basket or cage. The basket has solid side walls open at the top and a permeable bottom that is selectively openable. A carriage, or car, is used to transport the basket to the preheating apparatus. The carriage is driven to a position under a raised hood connected to a waste-gas line, and the hood is then lowered until its rim contacts the rim of the basket. The permeable bottom of the basket rests on a mouthpiece located at the carriage and connected to the waste gas line.
Both of these prior art devices employ only one basket connected to a waste-gas line, and the waste gases always flow through the basket from top to bottom. In addition, the hot gas supply to the preheating apparatus is interrupted during each changeover as the basket containing the preheated steel scrap is removed from the preheating apparatus so as to transfer the preheated scrap into the smelting furnace.
An arrangement for preheating scrap having a rotatable platform for two or more scrap baskets is disclosed in German patent publication DE OS 32 43 128. A basket containing preheated scrap is swiveled away from a waste gas line while a new basket is swiveled toward the waste gas line. Gas lines provided with valves or valve systems lead to the scrap baskets. The hot gas can be kept away from or guided away from or guided past the scrap basket or scrap baskets during a changeover by means of the valves or valve systems. The rotating platform and the valves of a duct system for the hot air or hot gas are so constructed that a first basket and a second basket can be heated simultaneously while a third basket location facilitates a changeover. This reference, however, does not disclose the construction of the baskets although it appears, based on the disclosed construction of the installation, that conventional baskets provided with base covers are intended to be used.
A disadvantage of the device disclosed by German patent publication DE-OS 32 43 128 is that it is necessary to guide the gas away from or past the preheating station when changing the baskets.
Another disadvantage of the scrap preheating arrangements disclosed by the above-mentioned prior art is that the hot waste gas is guided from top to bottom of a basket so that some constituents, notably small particles, are also melted along with the steel scrap. These constituents are entrained by the gas flowing downward through the burden column from the top and settle on or near the cooler base of the basket in the form of so-called skull.
OBJECTS OF THE INVENTION
In consideration of the aforementioned disadvantages, the present invention has the primary object of providing, in a cost and energy-efficient manner, a scrap preheating process and a scrap preheating apparatus, in which more than one scrap-filled receptacle can be preheated simultaneously and, during changeover, hot heating gases to a preheated receptacle may be rerouted to another scrap-filled receptacle.
A further object of the invention is to provide an apparatus to facilitate the movement of receptacles into and out of fluid communication with an arrangement of pipelines for preheating scrap.
Yet a further object of the invention is to minimize the amount of light solids entrained and introduced continuously into preheating stations during the operating phase of the smelting furnace.
Still another object of the invention is to provide a receptacle that can withstand the impact of scrap during loading thereof while providing desirable heat transfer and handling characteristics.
SUMMARY OF THE INVENTION
According to the inventive preheating process, furnace waste gases are guided to a waste-gas combustion chamber incorporated in a waste-gas outlet line, and are burned therein with air to generate a hot combustion gas or heating gas. The hot combustion gas is fed to a preheating apparatus and, more particularly, to a plurality of scrap-filled receptacles located at plural preheating stations of the preheating apparatus, and then exits through an outlet.
The combustion gas flows through the scrap-filled receptacles without substantial interruption with respect to time. During a receptacle changeover, a receptacle containing preheated scrap is removed from a preheating station so that the preheated scrap contained therein may be transferred to the smelting furnace. The hot combustion gas to that preheating station is temporarily rerouted so that it flows through those receptacles still remaining at their preheating stations.
At least two receptacles are connected to the hot gas supply. Individual receptacles are preferably connected for serial gas flow, but may also be connected for parallel flow or any combination thereof. The apparatus is configured in such a way that the combustion gas flows through the receptacles from bottom to top.
Scrap is inserted into receptacles that are, preferably, thermally insulated and cylindrically-shaped. The bottom opening of each receptacle is covered by a gram that is preferably formed of heat-resistant material. The openings of the grate are dimensioned so as to prevent scrap from falling through during transportation, while allowing the hot combustion gas to flow through the openings without substantial obstruction. In order to prevent damage to the grate while filling the receptacles with scrap, the grate is preferably set on a baffle plate having a brush-type construction which fills the openings of the grate. The brush-type construction helps absorb the impact forces from the scrap being loaded. The scrap receptacles are transported to the scrap preheating station with the grate facing downward.
According to the invention, the scrap preheating area has a construction which allows individual receptacles to be moved and positioned selectively and independently one from another. Undercarriages are used for guiding individual receptacles into or away from preheating stations along a predetermined path such, for example, as a circular path.
The preheating stations preferably have associated stationary pipelines, for example as supply lines and discharge lines for routing the hot combustion gas into and out of the scrap-filled receptacles. Hoods are disposed at the ports of the gas supply and discharge lines. Gas-tight connections between the gas lines and their corresponding receptacles are achieved by moving the hoods vertically toward their corresponding receptacles and/or moving the receptacles vertically toward the hoods. After establishing fluid communication between the receptacles and the gas lines, the combustion gas is caused to flow from the supply lines, through the receptacles, and out through the discharge lines.
The grate completely fills the bottom opening of a receptacle. The gas flowing against the grate is distributed uniformly outside the grate and flows through the receptacle so as to preheat all of the scrap in the receptacle. The rate of flow is selected so that individual light particles contained in the scrap are not entrained by the gas flowing vertically upward through the receptacle.
In order to empty the scrap receptacles, the receptacles are rotated about their horizontal axis immediately prior to approaching the smelting furnace. In the event the receptacles are outfitted with top covers, the receptacles are transported to a suitable location for proper removal of the top covers prior to charging of the smelting furnace.
The arrangement of the pipeline system and valves permits selective control of the flow of the heating gases; more particularly, a user may select not only serial flow of combustion gas through the scrap receptacles but also parallel flow of the combustion gas. If desired, even a free flow of hot combustion gas may be channeled to appropriate sites of the mill.
There may additionally be provided a measuring and regulating station such, for example, as an electronic sensor-controller communicating with and controlling the various operative parts of the invention, including the valves, undercarriages, hood adjusting mechanism, and exhaust fan.
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.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, wherein like reference characters denote similar elements throughout the several views:
FIGS. 1, 2 and 3 schematically depict a preheating apparatus in accordance with the invention at different flow configurations;
FIGS. 4 and 5 are a cross-sectional view and a top view, respectively, of a preheating area; and
FIG. 6 is a side-sectional view of a scrap receptacle and baffle plate.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A smelting furnace 10 having a lower vessel 11 and an upper vessel 12 with a cover 14 is shown schematically in FIGS. 1 to 3. The cover 14 has a scrap inlet 15. Further, a waste-gas outlet line 13 communicating with a waste-gas combustion chamber 16 is connected to the upper vessel 12. The waste-gas combustion chamber 16 has an air supply (not shown). Furnace-waste gas is burned in the waste-gas combustion chamber 16 to form a hot combustion gas, or heating gas, which is fed through a gas supply line 17 via a gas pipeline arrangement 20 to a scrap preheating station 50, and is then discharged with or without the aid of an air mover such, for example, as an exhaust fan 19 via a gas discharge line 18. The air mover may be located upstream or downstream from the preheating stations 51, 52.
A preferred embodiment of the gas pipeline arrangement 20 includes the gas inlet lines 22 and 24 which are connected with one another by an inlet connection line 26 and an inlet bypass line 28. In a serial flow configuration, the hot combustion gas is fed to the scrap receptacles 61, 62 through the gas inlet 22 of the preheating station 54, into or upon which a scrap receptacle 61 is located, and through the gas inlet line 24 of the preheating station 55, into or upon which a scrap receptacle 62 is positioned. The gas outputs of the scrap receptacles 61, 62 located at stations 54 and 55 are fed to the gas outlet lines 23, 25 which are themselves connected with one another by an outlet connection line 27 and an outlet bypass line 29. In addition, the inlet connection line 26 and outlet connection line 27 are directly connected with one another by a central pipe 21. An open or free-position station 56 is not connected to any gas inlet or outlet lines, and is used for facilitating a receptacle changeover.
The gas inlet lines 22, 24 have valves 31, 33, respectively, in a region between the inlet connection line 26 and the outlet bypass line 28. The inlet connection line 26 has valves 35, 36 arranged on either side of the connection to the central pipe 21. The outlet lines 23, 25 have valves 32, 34 in a region between the outlet connection line 27 and the outlet bypass line 29. The outlet connection line 27 has valves 37, 38 on either side of the connection to the central pipe 21.
The scrap preheating area 50, as illustrated in FIGS. 1 to 3, has two preheating stations 54, 55 and a free-position station 56. In addition, the scrap preheating area 50 has undercarriages 51, 52 which can selectively guide receptacles 61, 62 to either of the preheating stations 54, 55 or to the free station position 56 along a predetermined path.
A scrap yard 80 is illustrated schematically at the upper left-hand corner of FIGS. 1 to 3. A magnet 82 carried by a hook 81 of a scrap crane may, by way of example, be used for transferring scrap into a receptacle 69.
FIG. 1 illustrates a serial-flow configuration in which the valves 32, 33, 35 and 38 are closed. The hot combustion gas flows through the scrap receptacle 61 via gas inlet line 22. The gas then exits receptacle 61 through gas outlet line 23 and flows through the outlet connection line 27, then through the central pipe 21, inlet connection line 26 and gas inlet line 24, and into the scrap receptacle 62. The combustion gas exits the receptacle 62 and flows into the outlet line 25 and outlet bypass line 29. The gas is discharged via gas discharge line 18, preferably with the aid of an exhaust fan 19 which may be located either upstream or downstream from the preheating stations 54, 55.
In FIG. 2, the valves 32, 35, and 38 are closed while valve 33 is open, and valves 31, 36 and 37 (which were open in FIG. 1) are now closed. FIG. 2 demonstrates that during a changeover the combustion gas may be routed to flow continuously and exclusively through the receptacle 62 positioned at the preheating station 55. During this changeover, the preheating station 54 is open or unused and the receptacle 61 has been moved to the free-position station 56 by the undercarriage 51. From the free-position station 56, receptacle 61 can be removed and transported to scrap inlet 15 for transfer of scrap to the smelting furnace 16. While the receptacle 61 is being unloaded, the scrap receptacle 69 is picked up from the scrap yard 80 and deposited at preheating station 56. The receptacle 61 is then transported by the undercarriage 51 to the preheating station 54.
As may be seen in FIG. 3, the valves 31, 34, 36 and 37 are there closed, while the rest of the valves are open. In this third-disclosed flow configuration, the hot combustion gas flows through the scrap receptacle 62, which was heated during the changeover, and then through the scrap receptacle 69 which has just been moved up from station 56. After delivering its preheated scrap to the smelting furnace 10, the scrap receptacle 61 is transported to the scrap yard 80 with its bottom side facing downward.
In FIG. 4, the valves 31, 32, 33, 34, 35, 36, 37 and 38 between the gas supply line 17 and the gas discharge line 18 are in the same open or shut positions as those depicted in FIG. 1. Like the receptacles in FIG. 1, the receptacles 61, 62 in FIG. 4 are heated serially by the combustion gas. FIG. 4 also shows two different manners of positioning scrap receptacles 61, 62 in the undercarriages 51, 52 relative to the hoods 41, 42, 43, 44. The hoods 41, 42, 43, 44 are disposed at the ports of the inlet and outlet lines 22, 23, 24, 25 and are used for sealing the top and bottom openings of the receptacles so as to establish fluid communication therewith.
As seen on the left-hand side of FIG. 4, a receptacle 61 may be placed on a hood 42 rigidly connected to the gas inlet line 22 so as to establish a gas-tight connection therebetween. The receptacle 61 may be raised and lowered by a lifting device 59 mounted on the undercarriage 51 and acting on supporting pins 63 of the receptacle 61. A movable hood 41 which may be raised and lowered by a hood adjusting mechanism 45 secured at the port of the outlet line 23 facilitates the establishment of a gas-tight connection with the top opening of the receptacle 61.
The right-hand side of FIG. 4 depicts another embodiment in which the scrap receptacle 62 is positioned in the undercarriage 52. The receptacle 62 rests against a hood 43 so as to establish fluid communication therebetween. The hood 43 may be displaced coaxially relative to the gas inlet line 24 using a hood adjusting mechanism 46. The receptacle 62 has a top cover 68 with an adjustable opening. The top cover 68 is selectively opened while the scrap is preheated, and the top cover rests against a hood 44 thereby sealing the region around the opening of the top cover 68. The hood 44 is movable coaxially relative to the outlet 25 using a hood adjustment mechanism 47.
FIG. 5 shows a cross-sectional view through the scrap preheating area 50 along the lines A--A in FIG. 4. Also illustrated is the undercarriage 51 with the scrap receptacle 61 supported thereon through supporting pins 63 located at the free-position station 56. The undercarriage 51 has a carousel-type construction. The undercarriage 51, in the embodiment illustrated in FIG. 5, is rotatably mounted at one end and movably supported on an underlying support surface at another end, so that it may be rotated about the central axis I by a drive 57 such, for example, as a motor. The drawing further depicts the undercarriage 52 with a scrap receptacle 62 supported thereon and located at the preheating station 55. The undercarriage 52 may also be moved by a drive such, for example, as a motor 58. The preheating station 54 is unoccupied in FIG. 5.
Although not shown in the accompanying figures, it is contemplated that a person ordinarily skilled in the art can readily provide a measuring and regulating mechanism such, for example, as an electronic sensor-controller operable so that the various operating parts of the invention, including the valves, undercarriages, hood adjusting mechanism, and exhaust fan, may be full or partially automatically-controlled.
FIG. 6 is a side-sectional view through a preferred embodiment of a scrap receptacle 60 having a casing 64, a top opening, and a bottom opening. The receptacle 60 is generally cylindrical in shape and has a thermal insulation 65 disposed on and along the interior surface of the receptacle 60. The casing 64 has supporting pins 63 projecting outwardly from an outer of the casing 64. The bottom opening 66 of the receptacle 60 is covered by a grate 67.
Brush elements 84 disposed on a baffle plate 83 are dimensioned for slidable receipt through the openings of the grate 67. The brush elements 84 may be formed of shock-absorbing material 85 or damping for resilient elements 86 such, for example, as springs. Thus, when the grate 67 of a receptacle is placed on the baffle plate 83, damage to the grate 67 of receptacle 60 can be prevented or at least minimized during loading of scrap.
While there have been 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 disclosed invention may be made by those skilled in the art without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.
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The invention is directed to a process and apparatus for preheating and transferring scrap into smelting furnaces for steelmaking or the like. The scrap is preheated by energy contained in the waste gases from the smelting furnace, which energy comprises sensible heat and chemically bonded heat in the combustible portions of the waste gases. The furnace-waste gases are guided to a waste-gas combustion chamber incorporated in a waste-gas outlet line and are burned therein with air to generate hot combustion gases which are fed to the scrap in the receptacles at a preheating station and then sucked out via an exhaust fan. After the scrap reaches the desired temperature, the receptacle containing the preheated scrap is removed from the preheating station so that the preheated scrap may be transferred to the smelting furnace. During this receptacle changeover process, the hot combustion gases are rerouted to another scrap-filled receptacle at the preheating station using a pipeline arrangement.
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BACKGROUND OF THE INVENTION
The present invention relates to a picking-up apparatus for converting an optical image of an object into an electrical picture signal, particularly a television signal.
In known picking-up apparatuses such as a television camera a vidicon tube is generally used as an image picking-up device. However television cameras comprising the vidicon tube are very large in size, heavy in weight, and quite expensive in cost, because even the smallest one the vidicon tube has a diameter of 16.93 mm (2/3 inches) and a length of 150 mm (5.9 inches). Moreover deflection coils, focusing coils, etc. are also large and heavy and a power dissipated at a heater and various electrodes are also large. Further in order to drive the vidicon tube properly it is necessary to provide a power supply source of large capacity. A color television camera comprises a single vidicon tube or a plurality of vidicon tubes, e.g. three vidicon tubes. In the former camera it is difficult to obtain a high resolution in a displayed color image, while in the latter camera it is necessary to take into consideration a stability in registeration, and further the size, weight and power consumption of such a camera are extremely large.
Nowadays there has been developed a semiconductor image sensor of self-scanning type such as BBD and CCD. These image sensors are formed by semiconductor integrated circuits and thus are inherently small in size, light in weight and little in power dissipation. When the television camera is formed by such semiconductor image sensor, it is necessary to provide a two dimensional image sensor array of self-scanning type consisting of 500×400 elements even for a black and white television camera tube. The number of elements should be further increased in case of a color television camera tube. According to the present technical level it is quite difficult to manufacture such a two dimensional image sensor array of large size without defects with a high yield. Therefore such an image sensor is liable to be very expensive.
SUMMARY OF THE INVENTION
The present invention has for its object to provide a picking-up apparatus which is small in size, light in weight, and cheap in cost and has excellent resolution by providing a linear image sensor array of self-scanning type which can be manufactured in a relatively simple manner with a high yield.
A picking-up apparatus for converting an optical image of an object into an electrical picture signal according to the invention comprises
a lens system for forming on an image plane an image of an object to be picked-up;
a scanner for optically scanning the image of the object in a first direction;
a picking-up device including at least one linear image sensor array of self-scanning type arranged in said image plane in a second direction which is substantially perpendicular to said first direction; and
means for driving said scanner and linear image sensor array in synchronism with each other.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view showing an embodiment of a color television camera according to the invention;
FIG. 2 is a plan view illustrating a picture frame and a scanning position indicating mark;
FIG. 3 is a perspective view showing an arrangement of a color filter and a linear image sensor array;
FIG. 4 is a block diagram depicting an embodiment of a control and process circuit;
FIG. 5 is a schematic view illustrating another embodiment of the color camera according to the invention; and
FIG. 6 is a schematic drawing illustrating the use of the linear image sensor array of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a schematic view illustrating an embodiment of the pick-up apparatus according to the invention for use in a color television display system. An image of an object 1 to be picked-up is formed by an objective lens system 2 on an image plane F. In this image plane there is arranged a picture frame 3 having formed a window 3A of suitable dimensions therein. As shown in FIG. 2 along one side of the frame 3 is provided a scanning position indicating mark 4 which comprises a luminescent portion in the form of a wedge in a scanning direction shown by an arrow S. An amount of light emitted from the mark 4 varies along the scanning direction S.
In order to scan the image of the object 1 formed in the image plane F there is provided a scanner 6 comprising a plane mirror 6A arranged swingably about an axis 6B as shown by an arrow W at a given period and an electromagnetically driving means 6C. In order to compensate a deviation in an optical path length due to angular position of the mirror 6A, i.e. deflection angle, an f-θ lens system 5 is provided. By means of such f-θ lens system 5 the image of the object is always formed on a flat object focal plane regardless of the deflection angle of the scanner 6. In this embodiment the f-θ lens system comprises two lenses, one of which is arranged in front of the mirror and the other behind the mirror viewed in the optical path.
A light ray reflected from the mirror 6A is incident upon a dichroic mirror 7 and is divided into a red and blue component and a green component. The red and blue component forms a red and blue image on a linear image sensor array 8 of self-scanning type such a CCD. The linear array 8 is arranged in a direction perpendicular to the scanning direction. Then the image sensor 8 produces red and blue color signals. The green color component passing through the dichronic mirror 7 forms a green image on a linear image sensor array 9 of self-scanning type which is arrange in a direction perpendicular to the scanning direction. This image sensor 9 produces a green color signal. Since the green signal is predominant in the luminance signal, the green signal may be used as the luminance signal.
As shown in FIG. 3 in front of the linear image sensor array 8 is provided a color filter assembly 8A which includes red and blue color filter elements R and B, respectively. In this embodiment since use is made of the image sensor 8 composed of CCD which has a lower sensitivity for the blue light the number of the blue filter components B is three times larger than that of the red filter elements R. It should be noted that if the sensitivity of the image sensor 8 is substantially equal for red and blue light, the red and blue filter elements R and B may be arranged alternately.
The scanning position indicating mark 4 is also scanned by the scanner 6 and its image is formed on a photo-electric element 10 which is arranged substantially in alignment with the linear image scanner 9.
The picture signals from the linear image sensors 8 and 9 and an electrical output from the element 10 are supplied to a control and process circuit 11. The circuit 11 produces scanning clock pulses for the image sensors 8 and 9 in synchronism with the deflection angle of the scanner 6. Information with respect to the deflection angle is obtained from the output signal from the photoelectric element 10. For instance, an amplitude of the output signal from the element 10 varies in accordance with the deflection angle of the mirror 6A. The circuit 11 also supplies a driving signal to the driving means 6C of the scanner 6. In this manner the scanning of the scanner 6 and the image sensors 8 and 9 can be always made in synchronism with each other. The circuit 11 processes the picture signals supplied from the image sensors 8 and 9 so as to produce a color television signal adapted to given color television standards. The color television signal thus produced is supplied to a conventional color television receiver of monitor display device 21 and the image of the object 1 can be displayed on its screen. It is convenient that the control and process circuit 11 is so constructed that the scanning periods of the scanner 6 and the image sensors 8 and 9 are made in coincident with vertical and horizontal scanning periods, respectively of the color television standards.
FIG. 4 is a block diagram showing one embodiment of the control and process circuit 11. The circuit 11 comprises a standard pulse generator 12 which supplies given clock pulses to the linear image sensor arrays 8 and 9, vertical synchronizing pulses to a scanner driving circuit 13 and vertical and horizontal synchronizing pulses to an NTSC encoder 14. The scanner driving circuit 13 includes a waveform shaper circuit which converts the vertical synchronizing pulses into a sawtooth signal. The sawtooth signal thus formed is supplied to one input of a differential amplifier 15. The sawtooth signal is also supplied to a pluse compensator circuit 16, to which the sawtooth output signal supplied from the photoelectric element 10 due to the scanning of the scanning position indicating mark 4 (FIG. 2) is also fed through an amplifier 17. The phase compensator circuit 16 compares phases of these sawtooth signals to produce a phase difference and generates a phase compensating signal in accordance with the detected phase difference. This phase compensating signal is supplied to the other input of the differential amplifier 15. The output signal from the differential amplifier 15 is supplied to the electromagnetic means 6C of the scanner as the driving signal. In this manner the mirror 6A of the scanner can be swingably moved accurately in accordance with the sawtooth output signal from the scanner driving circuit 13. Since the sawtooth signal has the period equal to the vertical scanning period of the television standards the image of the object to be picked-up can be scanned vertically in synchronism with the vertical synchronizing period of the standard television signal.
The horizontal scanning of the image of object can be carried out by the self-scanning of the linear image sensor arrays 8 and 9 under the control of the clock pulses supplied from the standard pulse generator 12. Therefore the output picture signals from the linear arrays 8 and 9 can be considered as those obtained from a two-dimensional image sensor. The picture signals from the linear image sensor arrays 8 and 9 are supplied to a matrix circuit 18 through amplifiers 19 and 20, respectively. In the matrix circuit 18 the red and blue picture signal and the green picture signal are separated into red, blue and green color signals. These color signals are supplied to the NTSC encoder 14 which generates a color television signal with the given NTSC standards.
FIG. 5 is a schematic view illustrating another embodiment of the picking-up apparatus according to the invention. In this embodiment the linearity of a scanner 6 is excellent and thus it is not necessary to detect the scanning position of the scanner 6 and to compensate the phase difference of the dirving signal supplied to an electromagnetic driving means 6C of the scanner 6. Therefore in this embodiment it is possible to delete the scanning position indicating mark 4, the photoelectric element 10 and the phase compensator circuit 16 of the beforementioned embodiment. That is to say the sawtooth driving signal from the scanner driving circuit can be directly supplied to the electromagnetic driving means 6C of the scanner 6. Further in this embodiment an f-θ lens 5 has function of an objective lens and thus projects an image of an object 1 onto linear image sensor arrays 8 and 9. As shown in FIG. 6 successive elements 9a of the linear image sensor array 9 may be used for receiving the scanned image of the indicating mark 4.
As explained above according to the invention use can be made of the simple and cheap linear image sensor array and the image of the object to be picked-up is projected on the image sensor with scanning the image in the direction perpendicular to the scanning direction of the image sensor. Therefore the picking-up apparatus of the invention is quite cheap. Further the linear image sensor array can be constructed by the semiconductor image sensor array such as CCD and BBD and thus the picking-up apparatus according to the invention can be made small in size, light in weight and low in power consumption.
It should be noted that the present invention is not limited to the embodiments explained above, but many modifications can be conceived by those skilled in the art within the scope of the invention. In the above embodiments use is made of the two linear image sensor arrays 8 and 9 for obtaining the color picture signals, but the three color picture signals may be produced by a single linear image sensor array. In this case a color filter comprising the red, blue and green color filter elements may be arranged in front of the image sensor array. Since the green color signal may be used as a luminance signal the green color filter elements may be omitted. Further in case of producing a black and white television signal it is sufficient to provide a single linear image sensor array without a color filter. In the embodiment shown in FIG. 1 the scanned image of the scanning point indicating mark 4 is received by the separate photoelectric element 10 arranged in alignment with the image sensor array 9, but the element 10 may be provided in alignment with the other image sensor array 8. Further the photoelectric element 10 may be constructed by a plurality of successive elements of one of the linear image sensor arrays 8 and 9. Moreover the scanner 6 may comprise other scanning means such as a rotating multi-facet mirror wheel instead of the swinging plane mirror. Further it should be noted that when the deviation of the optical axis due to the deflection angle of the scanner may be neglected, the f-θ lens system may be omitted.
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A picking-up apparatus such as a color television camera for converting an image of an object to be picked-up into an electrical picture signal comprises a lens system such as an objective lens system for forming the image of the object on an image plane, a scanner comprising a swingable plane mirror for optically scanning the image of the object in a first direction, i.e. a vertical direction of a television raster scan, at least one linear image sensor array of self-scanning type arranged in said image plane in a second direction which is perpendicular to the first direction; i.e. a horizontal direction of the television raster scan, and a control and process circuit for driving the scanner and linear image sensor array in synchronism with each other.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention pertains to modular forms for forming free standing, concrete-filled walls and, more particularly, to modular, pre-insulated forms readily assembled and adapted to receive concrete therein.
The process of forming vertical walls from poured concrete has been known for centuries. The process, while theoretically simple, typically requires highly skilled laborers and expensive forms to accomplish. Forms may be either built for single use or may be formed from modular sections assembled to the required configuration. Upon curing of the concrete wall poured therein, the reusable forms are typically removed and stored for later use on another project.
Insulated concrete walls are sometimes constructed using form assemblies having insulation disposed as a part of the form. The form becomes part of the concrete wall. This type of construction is typically referred to as lost form construction.
Regardless of the type of form utilized to construct a poured concrete wall, two major problems remain. First, the construction or assembly of forms typically requires skilled labor and is time intensive. In addition, a large capital expense is typically required in obtaining reusable forms. There is further expense involved in removing forms from storage, transporting forms to a job site, removing forms once a concrete wall has sufficiently cured, and finally, shipping the forms back to storage. When forms are not properly constructed or set, finished walls may be out of square or plumb, be of the wrong dimension, and/or have bulges or other abnormalities. It is not uncommon have to destroy one or more of the poured walls, reset the forms, and re-pour the concrete. This results in further expense as well as delays in the construction project.
The second problem is that poured concrete walls constructed using forms of the prior art are notoriously difficult to finish.
2. Discussion of the Related Art
Several attempts to provide lost form type forms for building concrete filled walls appear in the prior art. For example, U.S. Pat. No. 5,311,718 for FORM FOR USE IN FABRICATING WALL STRUCTURES AND A WALL STRUCTURE FABRICATION SYSTEM EMPLOYING SAID FORM, issued May 17, 1994 to Jan P. V. Trousilek teaches a modular form system utilizing prefabricated plastic forms.
U.S. Pat. No. 5,323,578 for PREFABRICATED FORMWORK issued Jun. 28, 1994 to Claude Chagnon et al. shows a prefabricated, collapsible formwork having flexible connecting elements.
U.S. Pat. No. 5,860,262 for PERMANENT PANELIZED MOLD APPARATUS AND METHOD FOR CASTING MONOLITHIC CONCRETE STRUCTURES IN SITU, issued Jan. 19, 1999 to Frank. K. Johnson provides a system of interlocking form sections for forming continuous concrete walls, the form sections becoming a permanent part of the finished wall.
U.S. Pat. No. 6,178,711 for COMPACTLY-SHIPPED SITE-ASSEMBLED CONCRETE FORMS FOR PRODUCING VARIABLE-WIDTH INSULATED-SIDEWALL FASTENER-RECEIVING BUILDING WALLS, issued Jan. 30, 2001 to Andrew Laird et al., teaches yet another system for assembling forms on site to fabricate a lost form concrete wall having a cavity into which reinforcing steel, electrical and/or communications conduits, plumbing, etc. may be placed prior to filling the form with concrete.
U.S. Pat. No. 6,263,628 for LOAD BEARING BUILDING COMPONENT AND WALL ASSEMBLY METHOD, issued Jul. 24, 2001 to John Griffin teaches another lost form system wherein regularly spaced apart studs help define a cavity into which concrete is poured.
U.S. Pat. No. 6,321,498 for FORMWORK FOR BUILDING WALLS, issued Nov. 27, 2001 to Salvatore Trovato teaches another modular form system for creating a lost form, concrete filled, insulated wall.
U.S. Pat. No. 6,363,683 for INSULATED CONCRETE FORM, issued Apr. 2, 2002 to James Daniel Moore, Jr. shows yet another modular form system for fabricating lost form, concrete filled, insulated walls.
None of the patents and published patent applications, taken singly, or in any combination are seen to teach or suggest the novel free-standing form system for fabricating an insulated, concrete filled wall of the present invention.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided a prefabricated concrete form for forming a lost form, pre-finished concrete wall. An insulating layer is preformed on an outside (i.e., earth facing) side of the form. The inside of the form has a rough finished surface that is treatable with any typical decorative finish commonly used in the industry with regard to interior wall finishing. The form provides metal studs, typically on conventional sixteen inch centers, thereby allowing treatment of the resulting concrete wall in a manner similar to a wood framed wall.
The novel system allows placement of conduits for wiring either electrical power or so-called low voltage circuits (e.g., telephone, TV cable, network wiring, audio cables, etc.) within the wall. Water supply and drain lines may also be placed within the wall prior to filling the forms with concrete.
It is, therefore, an object of the invention to provide a modular, free-standing lost form concrete form for creating a concrete-filled, free standing wall.
It is another object of the invention to provide a modular, free-standing lost form concrete form that may readily be interconnected to form long, continuous wall sections.
It is an additional object of the invention to provide a modular, free-standing lost form concrete form wherein conduits for electrical circuits and/or water supply and drain lines may be preinstalled within the form prior to filling the form with concrete.
It is a further object of the invention to provide a modular, free-standing lost form concrete form having insulating board pre-placed on the outside of the form.
It is a still further object of the invention to provide a modular, free-standing lost form concrete form having a magnesium oxide insulating board pre-placed on the outside of the form.
It is another object of the invention to provide modular, free-standing lost form concrete form into which an opening to accommodate a door, window, or other portal may readily be placed.
It is yet another object of the invention to provide a modular, free-standing lost form concrete form that has metal studs on a standard center-to-center spacing, for example, 16 inch centers, pre-placed within the form.
BRIEF DESCRIPTION OF THE DRAWINGS
Various objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
FIG. 1 is a front, perspective, schematic view of a section of the free-standing form in accordance with the invention;
FIG. 2 a is an end, perspective, schematic view of the free-standing form of FIG. 1 ;
FIG. 2 b is a detailed portion of the view of FIG. 2 a;
FIG. 3 is a side, elevational, schematic view of two sections of the free-standing form of FIG. 1 joined together end-to-end;
FIG. 4 is a side, elevational, schematic view of the free-standing form of FIG. 1 showing electrical wiring boxes and conduits in place;
FIG. 5 is a side, elevational, schematic view of the free-standing form of FIG. 1 showing embedded water supply lines;
FIG. 6 is a side, elevational, schematic view of the free-standing form of FIG. 1 showing an alternate embodiment having water supply and drain lines embedded in the free-standing form of FIG. 1 ; and
FIG. 7 is a side, elevational, schematic view of the free-standing form of FIG. 1 showing framing modified to accommodate a window therein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention provides a modular, free-standing form system for forming concrete filled walls having a pre-insulated outer surface and a roughly finished inner surface. The forms are of the lost form variety wherein the form becomes a permanent part of the concrete filled wall.
Referring first to FIG. 1 , there is shown a front, perspective, schematic view of a section of the free-standing form in accordance with the invention, generally at reference number 100 . Free-standing form 100 has a length “l” 102 , a height “h” 104 , and a depth “d” 106 . In the embodiment chosen for purposes of disclosure, length “l” 102 is approximately 24 feet (7.3 m), height “h” 104 is approximately 10 feet (3 m), and depth “d” 106 is in the range of approximately 8-12 (0.2-0.3 m) inches. It will be recognized that free-standing form 100 may be implemented in many other sizes and, consequently, the invention is not considered limited to the dimensions chosen for purposes of disclosure. Rather, the invention covers free-standing forms in all practical dimensions.
Free-standing form 100 has a rectangular base 101 a formed from angle stock, typically treated steel angle stock or the equivalent. Long angle stock members 108 are joined to short angle stock members 110 at intersections thereof using self tapping screws 112 , not shown in FIG. 1 and best seen in FIGS. 2 a and 2 b . While self tapping screws 112 have been chosen for purposes of disclosure, it will be recognized by those of skill in the art that other suitable fasteners or joining methods may be substituted therefor. In addition to fasteners, adhesives or spot welding may be used to join long angle stock members 108 to short angle stock members 110 .
Top frame 101 b , substantially identical to the base 101 a is formed from long angle sections 108 and short angle sections 110 , also held together by self tapping screws 112 or the like.
Studs 114 are placed at predetermined intervals along both front and back long angle stock members 108 and are also attached to base 101 a and top frame 101 b by self tapping screws 112 or the like. Studs 114 are metal “C” studs well known to those of skill in the art and not further described herein. Studs 114 are typically placed at regular intervals on industry standard center-to-center spacing, for example 16 or 24 inch spacing behind stud material.
The depth dimension “d” 106 is established by spacers 116 that tie studs 114 located at the front of free-standing form 100 corresponding studs 114 at the rear thereof. Spacers 116 are short lengths of “C” stud material identical to the material from which studs 114 are fabricated.
Referring now also to FIGS. 2 a and 2 b , there are shown an end, perspective, schematic view of the free-standing form 100 and a detailed portion of the view of FIG. 2 a , respectively. Spacers 116 may readily be seen in FIGS. 2 a and 2 b.
A reinforcing steel bar, known as rebar 118 , is loosely secured to a top surface of spacer 116 by clamps 120 . Rebar is well known to those of skill in the art and is not further discussed herein. Further, rebar 118 forms no part of the present invention and is shown only to illustrate the intended use environment of free-standing form 100 .
Clamps 120 are typically straps such as one hole conduit straps well known to those of skill in the art. Clamps 120 are typically attached to the upper surface of spacers 116 by a single self tapping screw 112 . It will be recognized that many alternate clamps or fastening methods may be substituted for clamps 120 for securing rebar 118 to spacers 116 .
A sheet of insulating board 122 is shown attached to outer faces, not specifically identified, of studs 114 of both major surfaces of free-standing form 100 . In the embodiment chosen for purposes of disclosure, insulating board 122 is 12 mm (approximately 0.5 inch) thick magnesium oxide board such as Magnum® board provided by MBP Magnum Building Products of Tampa, Fla. USA. Magnesium oxide (MgO) board is chosen for its many desirable properties for below grade installation. MgO board is waterproof, mold and bacteria resistant, dimensionally stable, and is structurally durable. The insulating board 122 is attached to the MgO board. The MgO board is a minimum of 0.5 inch thick. While the MgO board has some insulating value, it is only R 1.2. The MgO board is fire rated, non-carcinogenic, insect proof (i.e., termites, carpenter ants), and silica free.
Referring now to FIG. 3 , there is shown a front, elevational, schematic view of a pair of free-standing forms 100 joined end-to-end to one another. When insulating board 122 is placed on a major surface of a free-standing form 100 , a gap 130 may be left to allow access to an interior region 128 within free-standing form 100 . Gap 130 allows access to end studs 114 so that two sections of free-standing form 100 may be joined end-to-end to one another. The gap is closed after joining forms.
Joining bolts 124 with washers 132 and nuts 134 may be used to abut end studs 114 of adjoining sections. It will be recognized by those of skill in the art that other devices and/or techniques may be used to join sections of free-standing form 100 to one another. Such devices and/or techniques are believed to be known and are not further discussed herein. The invention includes any and all such devices and/or techniques and is, therefore, not considered limited to joining bolts 124 , washers 132 , and nuts 134 chosen for purposes of disclosure.
Referring now also to FIG. 4 , there is shown a front, elevational, schematic view of free-standing form 100 having electrical boxes 136 embedded therein. Electrical boxes 136 are connected to conduits 138 that are placed within free-standing form 100 to allow in-the-wall wiring in the final concrete-filled wall section made from free-standing form 100 . While individual conduits 138 , each connected to a single box 136 are shown, it will be recognized that alternate wiring arrangements may be placed inside free-standing form 100 prior to the filling thereof with concrete. Boxes 136 are schematic and are intended to represent any electrical box whether for power or low voltage/communications applications.
Referring now also to FIG. 5 , there is shown a front, elevational, schematic view of a free-standing form 100 having liquid (e.g., water) supply lines 140 or similar plumbing embedded therein. Like conduits 138 ( FIG. 4 ), that are placed within free-standing form 100 , water supply lines 140 are routed to the top of free-standing form 100 for connection to hot and cold water supplies, not shown, or the like. It will be recognized that FIG. 5 is schematic and that water supply lines 140 may represent any in-the-wall plumbing such as a compressed air line, an oxygen line, a vacuum line, or any other supply or suction line.
Referring now also to FIG. 6 , there is shown a front, elevational, schematic view of a free-standing form 100 having both water supply lines 140 or similar plumbing, as well as a drain connection 142 embedded therein. In this embodiment, both water supply lines 140 and drain connection 142 are run horizontally across an interior region of free-standing form 100 . It will be recognized that drain line 142 is preferably installed with an appropriate slope. Both supply lines 140 and drain connection 142 may be connected to mating water supply lines 140 and/or drain line 142 at the interface between adjacent sections of free-standing forms 100 .
Referring now also to FIG. 7 , there is shown a front, elevational, schematic view of a free-standing form 100 having an opening 144 in the framing to allow installation of a window, not shown. Framing elements, possibly formed from the same material as studs 114 discussed hereinabove, are used to define opening 144 into which a pre-hung window or the like can be placed upon completion of the concrete filled wall defined by free-standing form 100 . It will be noted that any opening formed through free-standing form 100 must be sealed from front to back to seal the concrete pour, not shown, within free-standing form 100 . While an opening 144 for a window has been chosen for purposes of disclosure, it will be recognized that openings suitable for doors or other portals may likewise be placed in free-standing form 100 . Consequently, the invention is not considered limited to openings for windows but rather includes any opening through the wall formed by filling free-standing form 100 with concrete.
In use, one or more free-standing forms 100 are fabricated as described hereinabove. If two or more free-standing forms 100 are required to form the length of wall desired, adjacent forms must be secured to one another end-to-end. Any plumbing or electrical components that must connect at the edges of free-standing form 100 sections must be made.
Rebar must be inserted and secured within free-standing forms(s) 100 . For safety and aesthetics, exposed ends of free-standing form(s) 100 should be covered. Typically, the horizontal rebar is already installed in the walls. It is necessary to join the pre-installed rebar only where the wall sections come together.
Finally, once free-standing form(s) 100 are fully prepared and braced as required, concrete, not shown, may be poured into the hollow, interior spaces 128 within free-standing forms 100 . Once the concrete is cured, the resulting wall may be backfilled using backfilling materials and techniques well known to those of skill in the art. Interior finishing may be accomplished utilizing studs 114 or the insulating board 122 forming the interior surface of the wall.
When required, electrical circuits and/or plumbing may be completed using conduits 138 and/or water supply and drain lines 140 , 142 , respectively. Interior finishing of MgO walls is accomplished utilizing conventional materials and methods. All that is required prior to final finishing is taping and spackling the few joints where the wall sections join.
Since other modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the example chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention.
Having thus described the invention, what is desired to be protected by Letters Patent is presented in the subsequently appended claims.
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A free-standing, hollow, prefabricated concrete form for forming a lost form, pre-finished concrete wall having an insulating layer on at least one major surface, typically an outer, earth facing surface thereof. The inside of the form has a rough finished surface. The form provides metal studs, typically on conventional sixteen inch centers, thereby enhancing the strength of the wall. The form allows placement of conduits for wiring, either electrical power or so-called low voltage circuits (e.g., telephone, TV cable, network wiring, audio cables, etc.) within the wall. Water supply and drain lines may also be placed within the wall prior to filling the forms with concrete. Multiple prefabricated sections may be joined to one another end-to-end to fabricate longer walls.
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BACKGROUND OF THE INVENTION
The present invention relates to a monitoring system for motor vehicles that produces a warning signal when the pressure within a tire changes to an unacceptable level.
As is well known, the useful life of a tire is materially affected if the tire is operated over a prolonged period of time in an improperly inflated condition. Driving on an underinflated tire causes excessive flexing of the sidewalls of the tire that results in an inordinate buildup of heat in the tire and even may result in the tire becoming so hot that it will burst into flame. If the pressure in the tire falls to a sufficiently low level that the vehicle steers sluggishly, the operator probably will become aware that something is wrong with the vehicle and will stop and inspect the tires. However, if the degree of underinflation is only moderate, the operator of the vehicle may be become conscious of the underinflated condition of the tire until after the tire has been materially damaged.
When the vehicle is driven for prolonged periods of time in hotter climates, the hotter operating temperatures may cause the pressure within the tire to be increased to an objectionable high level at which excessive tread wear will occur and even may build up to such a high pressure that rupturing of the tire may result.
Various devices previously have been proposed for monitoring the pressure of a tire while in service and for producing a warning signal when the pressure of the tire changes from an acceptable level. Such devices usually have a sensor unit mounted on the wheel and an alarm component associated with the vehicle body and employ a purely electrical system or a combination of an electrical system and a mechanical system. A number of such systems depend upon a physical connection between the rotating wheel on which the sensor component is mounted and the alarm portion of the system associated with the vehicle body. Such physical connections, for example sliding electrical contacts, usually have not been found to be entirely satisfactory, however, since they can be rendered ineffective as a result of exposure to inclement weather or rough road conditions or merely because of wear of the contact surfaces after a prolonged period of use. Therefore, it is preferable that a system for monitoring tire inflation not rely on a physical connection for coupling the sensor circuit of the system mounted on the vehicle wheel with the alarm circuitry associated with the vehicle body. A number of monitoring systems that do not rely on a physical coupling between the sensor circuit of the system and the alarm circuitry have been suggested, some of which are described in U.S. Pat. Nos. 2,894,246; 3,093,812; 3,249,916; 3,374,460 and 3,602,884.
Many of the monitoring systems which previously have been proposed are objectionably complicated in their circuitry which not only materially adds to the initial cost of the system but also increases the number of potential sources for component failure. Use of circuitry that includes components within the sensor unit mounted on the wheel that require manual adjustment or "setting" to permit the monitoring system to function properly is objectionable since operation of the vehicle over rough roads may cause the component to be jolted out of proper adjustment and result in a malfunctioning of the system. Accordingly, it is desirable that the monitoring system be as simple in circuitry as possible with no variable components that require manual "setting" to permit the system to operate satisfactorily.
SUMMARY OF THE PRESENT INVENTION
The present invention provides a reliable system for monitoring the inflation of a tire while it is in service and which produces a warning signal to advise the operator of the vehicle when the pressure within the tire changes to an unacceptable level. The system includes a tire pressure sensor unit having a wire coil wound around a core connected in series with a pressure indicator responsive to a change in pressure to an unacceptable level of the air within the tire being monitored. The sensor unit is mounted on the wheel being monitored and is arranged so that as the wheel rotates the coil of the sensor unit passes during each rotation of the wheel in close proximity to a second coil wrapped around a core and mounted to the vehicle body. The second coil is a component of a circuit that is in electrical resonance at the frequency at which the system operates. The number of turns of wire in the coil in the wheel-mounted sensor unit is selected so that the circuit of the sensor unit when the pressure indicator is "open" is in electrical resonance with the circuit in electrical resonance mounted on the vehicle body.
In the operation of the system, if the pressure in the tire being monitored changes from a "normal" pressure to an unacceptable pressure level at which the pressure indicator in the circuit of the sensor unit is responsive, the voltage across the coil in the sensor unit circuit as it passes in close proximity to the coil mounted on the vehicle body will be different from that occurring across the coil before the pressure change took place. The voltage change, in turn, will change the voltage previously experienced across the coil on the vehicle body and will trigger the warning signal to indicate an unacceptable inflation condition of the tire.
DESCRIPTION OF THE DRAWINGS
The invention will be more fully understood by reference to the following description and to the drawings in which:
FIG. 1 shows a block diagram of one embodiment of the invention;
FIG. 2 shows the sensor unit of the embodiment of FIG. 1 mounted on the wheel of a vehicle with the coil of the alarm circuit mounted to the vehicle body in a position relative to the sensor unit so that the coil of the sensor unit passes in close proximity to the coil of the alarm circuit during each rotation of the wheel;
FIG. 3 illustrates the change of voltage across the coil of the alarm circuit of the embodiment shown in FIG. 1 during the period that the coil of the sensor unit passes in close proximity to the coil of the alarm circuit when the sensor circuit is "open";
FIG. 4 shows a block diagram of a second embodiment of the invention;
FIG. 5 shows a block diagram of still another embodiment of the invention;
FIG. 6 shows a circuit diagram illustrating an alarm triggering circuit which may be used with the embodiment of the invention shown in FIG. 1; and
FIG. 7 shows a circuit diagram illustrating an alarm triggering circuit which may be used with the embodiment of the invention shown in FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
The tire inflation monitoring system depicted in FIG. 1 includes a sensor circuit 10 and an alarm circuit 11 which is physically unattached to sensor circuit 10. The sensor circuit 10 contains a coil 12 wound on core 13 and serially connected to a pressure switch 14 which normally is maintained "closed" as long as the pressure within the tire being monitored is at a prescribed "normal" pressure but which becomes "open" in response to a drop in pressure within the tire below the responsive pressure of the pressure switch 14. The alarm circuit 11 includes a coil 15 wound on core 16 and serially connected with resistor 17 and a generating source of constant frequency alternating current such as oscillator 18. A condenser 19 is connected across the terminals of coil 15 and an alarm triggering circuit 20 (which may consist of the circuitry shown in FIG. 6 and which will be described below in greater detail) is connected across the terminals of resistor 17.
The sensor circuit 10 is attached to the wheel of the vehicle which is being monitored so that coil 12 rotates with the wheel as the wheel rotates. FIG. 2 shows one arrangement for mounting sensor circuit 10 to the wheel of the vehicle. As depicted in FIG. 2, the pressure switch 14 forms a part of the valve assembly of the tire 21 and is connected by wires 22,22 to coil 12 that is secured by bracket 23 to the wheel rim 24 on which tire 21 is mounted. Coil 15 of alarm circuit 11 is securely attached to the vehicle body 25 at a location so that, as the wheel rotates, coil 12 attached to wheel rim 24 will pass in close proximity to coil 15 attached to the vehicle body 25 (preferably within a distance of about 2 inches) during each rotation of the wheel.
Cores 13 and 16 around which coils 12 and 15 respectively are wound may be made either of powdered ferromagnetic material or powdered ferrimagnetic material. An example of a powdered ferromagnetic material is pure carbonyl iron powder. The powdered ferrimagnetic materials from which powdered cores usually are made include powdered ferrites of the spinel, magnetoplumbite, or garnet types.
The circuit that includes coil 15, resistor 17 and condenser 19, the "primary circuit," is designed to be tuned to electrical resonance at the frequency of the signal generated by oscillator 18. The condition of resonance can be achieved by a proper selection of coil 15 and condenser 19. For example, after selecting a particular condenser 19 for use in the circuit, the number of turns of wire in coil 15 will need to be chosen that will produce the desired resonant condition at the frequency of the signal emitted by oscillator 18. The correct number of turns of wire to be used in coil 15 can be determined by varying the number of turns of wire in the coil until the voltage across the coil is at a maximum (indicating that the circuit is in electrical resonance).
Also, the "secondary circuit" (which includes coil 12 and pressure switch 14) is designed so that it exhibits electrical resonance at the frequency of the signal generated by oscillator 14 when the pressure switch 14 is open and coil 12 is moved in close proximity to coil 15 as the wheel rotates. The desired condition of electrical resonance in the "secondary circuit" is achieved by the proper selection of the ratio of the number of turns of wire in coil 12 to the number of turns of wire in coil 15. In order to determine the number of turns of wire to be used in coil 12 to produce the desired condition of resonance, the number of turns of wire in the coil 12 are varied and the voltage across coil 12 measured for the varying number of turns of wire in the coil 12 as coil 12 is moved in close proximity to coil 15 with the "primary circuit" tuned to resonance at the frequency at which the monitoring system will operate and with the "secondary circuit" open until the number of turns of wire in coil 12 that produces the greatest voltage across coil 12 is determined. The number of turns of wire in coil 12 that produces the greatest voltage across coil 12 is the number of turns of wire that produces electrical resonance in the "secondary circuit" at the frequency of the signal emitted by oscillator 18. Alternatively, with the "primary circuit" tuned to resonance and the "secondary circuit" open the number of turns of wire in coil 12 are varied and the voltage across the condenser 19 measured (for each of the varying number of turns of wire in coil 12) as the coil 12 passes in close proximity to coil 15 until the voltage across condenser 19 reaches a minimum value (indicating that the "secondary circuit" is tuned to resonance at the frequency of the signal emitted by oscillator 18). The condition of electrical resonance in the "secondary circuit" can be attributed to the "effective distributed capacitance" characteristic exhibited by coil 12. When the "primary circuit" is tuned to resonance at the frequency of the signal generated by oscillator 18 and the number of turns of wire in coil 12 is selected to produce electrical resonance at the same frequency in the "secondary circuit" (with pressure switch 14 open), the "primary circuit" and the "secondary circuit" are considered to have "matched resonance" and the passing of coil 12 in close proximity to coil 15 will produce a noticeable change in voltage across the coils as long as pressure switch 14 is open.
During operation of the vehicle, it will be appreciated that during each rotation of the wheel with which the monitoring system is associated, coil 12 mounted on wheel rim 24 will pass in close proximity to coil 15 mounted on the vehicle body 25. As long as the pressure in tire 21 exceeds the pressure at which the pressure switch 14 responds, the pressure switch will remain closed and, since coil 12 is not in resonance with its "effective distributed capacitance" at the operating frequency of oscillator 18, the passing of coil 12 in close proximity to coil 15 will have no noticeable effect on the voltage across coil 15. However, if the pressure in tire 21 drops below the pressure at which pressure switch 14 is responsive, pressure switch 14 will "open" breaking the electrical circuit in which coil 12 is connected. The open circuit resulting from movement of pressure switch 14 to an "open" condition causes the "secondary circuit" to be in resonance with its "effective distributed capacitance" and in "matched resonance" with the "primary circuit" resonance. As a further result of the open circuit caused by the "opening" of pressure switch 14, the resonance frequency of the "primary circuit" during the time coil 12 passes in close proximity to coil 15 as the wheel rotates changes. The aforementioned change of resonant frequency of the "primary circuit" from frequency f o to frequency f o ' and the resulting drop in voltage across coil 15 from a voltage of V o when pressure switch 14 is closed to a voltage of V o ' when pressure switch 14 opens is illustrated in FIG. 3. As is indicated by the resonance curves in FIG. 3, when the tire 21 is properly inflated and pressure switch 14 is "closed," the voltage across coil 15 with the "primary circuit" in resonance at frequency f o , is at maximum voltage amplitude, V o (shown by solid line curve). However, when the pressure in tire 21 drops sufficiently and pressure switch 14 becomes "open," the resonant frequency of the "primary circuit" is now changed to a new resonant frequency of f o ' during the period that coil 12 passes in close proximity to coil 15 (shown by dot and dash curve). Nevertheless, the frequency of the signal being generated by oscillator 18 remains at f o and, therefore, the voltage across coil 15 drops to voltage amplitude V o ', as illustrated in FIG. 3. The drop in voltage across coil 15 (from V o to V o ') is "noticed" by the alarm triggering circuit 20 of the monitoring system and signals a warning to the operator of the vehicle that the pressure in tire 21 has dropped below an acceptable pressure.
The alarm triggering circuit 20 may be any alarm circuit responsive to a variation in voltage. One such alarm circuit is illustrated in FIG. 6 and is composed of a field effect transducer (FET), resistors R 1 , R 2 , R 3 and R 4 , a silicon controlled rectifier (SCR), a light emitting diode (LED), a buzzer, switch S 1 and the vehicle battery B. When the pressure in the tire 21 is within the "normal" range and pressure switch 14 of the monitoring system shown in FIG. 1 is in the "closed" position, the voltage across resistor 17 of alarm circuit 11 is of small magnitude and insufficient to produce a signal of large enough magnitude to trigger the SCR. However, if the pressure in tire 21 falls to the pressure at which pressure switch 14 responds (the pressure switch 14 having been selected to respond at a pressure at which an underinflation condition begins), pressure switch 14 opens and the voltage across resistor 17 increases sufficiently (because of the drop in voltage across coil 15 to V o ') during the period that coil 12 passes in close proximity to coil 15 as the wheel rotates to cause a signal of sufficient magnitude to be produced to trigger the SCR. The buzzer and LED then signal audible and visual warnings to the operator of the vehicle that the pressure within tire 21 has dropped below an acceptable level The buzzer will continue to sound until the circuitry of the alarm triggering circuit 20 is broken by manually "opening" switch S 1 .
The frequency at which the monitoring system functions is determined by the frequency of the signal generated by oscillator 18. Although the monitoring system can be designed to operate at relatively low frequencies, the number of turns of wire in coils 12 and 15 increase as the frequency at which the system operates is reduced. As a consequence, the monitoring system normally is designed to operate at a frequency above about 100 kilocycles per second.
It will be appreciated that a separate monitoring system will be used for each wheel to be monitored if the operator is to be informed of the particular wheel on which loss of tire pressure has occurred. Also, a visual light alone or a buzzer alone may be used in alarm stage 29 of the alarm triggering circuit 20, instead of both a buzzer and a visual light.
In the embodiment shown in FIG. 4, the monitoring system includes a sensor circuit 30 and an alarm circuit 31 physically unattached to sensor circuit 30. Sensor circuit 30 includes a coil 32 wound on core 33. One terminal of coil 32 is connected to ground while the other terminal of coil 32 is connected in series with pressure switch 34 which is maintained closed as long as the pressure within the tire being monitored is above the pressure at which the pressure switch 34 is responsive and which becomes "open" when the pressure within the tire drops below the response pressure of the switch. The pressure at which pressure switch 34 responds is chosen to correspond with the tire pressure at which underinflation begins. The pressure switch 34 in turn is "grounded" to the wheel. The coil 32 wound on core 33 may be attached to the wheel rim of the wheel being monitored as described above and pressure switch 34 may form a part of the valve assembly of the tire being monitored as described above. Alarm circuit 31 includes a coil 35 wound on a core 36. One terminal of coil 35 is connected in series to the central conductor 37 of coaxial cable 38 with the other terminal of coil 35 serially connected to the metal tubular conductor (or shield) 39 of coaxial cable 38. The central conductor 37 in turn is connected serially to resistor 40 which is connected serially to oscillator 41 which is connected to ground. One terminal of an alarm triggering circuit 42 (which may be the alarm triggering circuitry shown in FIG. 7) is connected at the juncture of resistor 40 and central conductor 37 of coaxial cable 38. The other terminal of alarm triggering circuit 42 is connected to ground.
Cores 33 and 36 around which coils 32 and 35 respectively are wound, like cores 13 and 16 of the embodiment shown in FIG. 1, may be made either of a powdered ferromagnetic material or a powdered ferrimagnetic material.
Coil 35 wound on core 36 is attached to the vehicle body so that as the wheel on which sensor circuit 30 is mounted rotates, coil 32 of sensor circuit 30 will pass in close proximity to coil 35 of alarm circuit 31.
Coaxial cable 38 provides the necessary capacitance in the alarm circuit 31 of the monitoring system shown in FIG. 4, and in this respect provides the function of condenser 19 of the monitoring system shown in FIG. 1.
The circuitry that includes coil 35 and coaxial cable 38, the "primary circuit," is tuned to electrical resonance at the frequency of the signal being emitted by oscillator 41. The condition of resonance can be achieved by a selection of a coil 35 having the proper number of turns of wire and a coaxial cable 38 of proper length to provide the needed capacitance. With a finite length of coaxial cable 38, one can determine the number of turns of wire that must be in coil 35 to provide the desired condition of electrical resonance by varying the number of turns of wire in the coil until resonance is reached.
The number of turns of wire in coil 32 of the "secondary circuit" (which includes coil 32 and pressure switch 34) is selected so that the "secondary circuit" with pressure switch 34 "open" exhibits electrical resonance at the frequency of the signal being emitted by oscillator 41. The proper number of turns of wire for use in coil 32 to produce the desired resonant condition can be determined in the same manner as described hereinbefore with regard to determining the proper number of turns of wire for coil 12 of the sensor circuit shown in FIG. 1. The "primary circuit" and the "secondary circuit" then will be in "matched resonance" as coil 32 passes in close proximity to coil 35 as the wheel rotates and a noticeable change in voltage across coil 35 will be noticed as the two coils pass in close proximity to each other during each rotation of the wheel as long as pressure switch 34 remains "open."
The monitoring system comprised of sensor circuit 30 and alarm circuit 31 works in essentially the same manner as sensor circuit 10 and alarm circuit 11 of the monitorning system shown in FIG. 1. As long as the pressure within the tire being monitored remains above the pressure at which pressure switch 34 responds, the voltage across coil 35 remains constant. However, when the pressure in the tire being monitored drops below the pressure at which pressure switch 34 responds, pressure switch 34 "opens" and in so doing causes the "secondary circuit" to become an open circuit and in electrical resonance with the "primary circuit." As a result, the voltage across coil 35 is significantly reduced during the period that coil 32 passes in close proximity to coil 35 as the wheel rotates. The decreased voltage amplitude across coil 35 during the period that coil 32 passes in close proximity to coil 35 is communicated to the alarm triggering circuit 42 and causes the triggering of the warning alarm.
The alarm triggering circuit 42 may be any alarm circuit responsive to a voltage variation. A suitable alarm circuit is illustrated in FIG. 7 and is composed of a signal pick-up stage 43, a rectifier stage 44, a comparator stage 45, and alarm stage 46. When the pressure in the tire is within a normal operaging pressure, the voltage amplitude (V o ) across coil 35 is relatively large. This relatively large amplitude voltage is registered in the signal pick-up stage 43, composed of resistors R 5 , R 6 , and R 7 and the field effect transistor (FET), and is transferred to the rectifier stage 44, composed of resistors R 8 and R 9 , condensers C 1 and C 2 and diode D 1 , which rectifies the signal to a DC voltage of relatively large value that appears as the input to the comparator stage 45, composed of resistors R 10 and R 11 and the Operational Amplifier (OP). The comparator stage 45 is adjusted so that a relatively large amplitude value DC voltage input will have a zero output. Thus, since the input to the comparator when pressure switch 34 is "open" is of relatively high level, the small output from the comparator stage 45 is insufficient to "set off" the alarm stage. However, when the pressure in the tire 21 drops below the pressure at which pressure switch 34 "opens," the relatively low amplitude voltage V o ' across coil 35 is registered in the signal pick-up stage 43 producing a small amplitude output signal from the signal pick-up stage 43 that is rectified to a small amplitude DC voltage signal in the rectifier stage 44. The small amplitude DC voltage signal appears as the input signal of the comparator stage 45 and being of small amplitude produces an output signal of the comparator stage of sufficient magnitude to cause the triggering of the alarm stage 46, composed of resistors R 12 and R 13 , diode D 2 , a silicon controlled rectifier (SCR), a light emitting diode (LED), a buzzer, switch S 2 and the vehicle battery B. Once the alarm stage 46 is triggered, the buzzer will continue to emit a warning signal until the circuitry is broken by manually "opening" switch S 2 .
The monitoring system shown in FIG. 5 includes a sensor circuit 50 and an alarm circuit 51. The sensor circuit 50 includes coil 52 wound on core 53 connected in series with pressure switch 54. Pressure switch 54 is a "dual action" pressure switch that is designed to remain "open" as long as the pressure within the tire being monitored stays within a predesigned range (which corresponds to the inflation pressure range of the tire that would be considered as a "normal" tire pressure), but which "closes" if the pressure within the tire drops below the pressure range or increases to a pressure above the pressure range. The alarm circuit 51 includes coil 55 wound on core 56 serially connected to a resistor 57 and condenser 58 which are serially connected with oscillator 59. Alarm triggering circuit 60 (which may consist of circuitry such as that described in U.S. Pat. No. 3,840,850) is connected across the terminals of condenser 58.
Cores 53 and 56, like cores 13 and 16 of the embodiment shown in FIG. 1 and cores 33 and 36 of the embodiment shown in FIG. 4, may be made from either a powdered ferromagnetic material or a powdered ferrimagnetic material.
The sensor circuit 50 is mounted on the wheel to be monitored and may be mounted in the manner shown in FIG. 2 with pressure switch 54 forming a part of the valve assembly and coil 52 wound on core 53 affixed to the wheel rim 24. Coil 55 wound on core 56 is mounted on the vehicle body at a location so that as the wheel rotates coil 52 will pass in close proximity to coil 55 during each rotation of the wheel.
The circuit that includes coil 55 and condenser 58, the "primary circuit," is tuned to electrical resonance at the frequency of the signal emitted by oscillator 59. As explained above in connection with the description of the monitoring systems shown in FIGS. 1 and 4, once a specific condenser 58 has been chosen, the number of turns of wire in coil 55 will need to be selected that will produce the desired condition of electrical resonance at the frequency of the signal generated by oscillator 59. Alternatively, if a specific coil 55 has been selected for use in the system, then a condenser 58 must be chosen that has the capacitance that will produce electrical resonance in the "primary circuit" at the frequency of the signal emitted by oscillator 59.
The number of turns of wire in coil 52 must be selected so that with pressure switch 54 in the "open" position and the "primary circuit" tuned to electrical resonance at the frequency of the signal generated by oscillator 59, the "secondary circuit" (which includes coil 52 and pressure switch 54) is in electrical resonance at the frequency of the signal generated by oscillator 59 as coil 52 passes in close proximity to coil 55 during the rotation of the wheel of the vehicle. The proper number of turns of wire to produce a condition of electrical resonance in the "secondary circuit" can be determined in the manner described above.
During operation of the monitoring system shown in FIG. 5, when the pressure in the tire mounted on the wheel which is being monitored is "normal" (that is, at a pressure within the pressure range at which pressure switch 54 remains "open"), the "secondary circuit" is an open circuit. Since the "primary circuit" in the alarm circuit 51 is tuned to electrical resonance the voltage across coil 55 is of relatively large amplitude until coil 52 passes in close proximity to coil 55 as the wheel rotates. During the short interval when coil 52 passes in close proximity to coil 55, the voltage across coil 55 is significantly reduced. The fluctuation in voltage across coil 55 is signaled to alarm triggering circuit 60 which is designed so that such fluctuation in voltage does not trigger the warning signal. However, when the pressure in the tire on the wheel being monitored drops below the pressure at which pressure switch 54 responds or increases to a pressure above the pressure at which pressure switch 54 responds, pressure switch 54 moves to the closed position. The "secondary circuit" no longer is an "open circuit" and now is not in "matched resonance" with the "primary circuit" of alarm circuit 51 during the short period that coil 52 of the "secondary circuit" passes in close proximity to coil 55 of the "primary circuit." Since the "primary circuit" and "secondary circuit" are not in "matched resonance," there no longer is a noticeable voltage drop across coil 55 during the period that coil 52 passes in close proximity to coil 55 but instead the voltage across coil 55 remains essentially constant and of large amplitude. The lack of significant fluctuation of the voltage across coil 55 as the wheel rotates is communicated to alarm triggering circuit 60. The constant large amplitude voltage communicated to the alarm triggering circuit 60 "sets off" the warning signal to warn the operator of the vehicle of the underinflated condition of the tire.
As is evident from the foregoing description of three embodiments of this invention, the "primary circuit" of the monitoring system of this invention is designed to be tuned to electrical resonance at the frequency at which the monitoring system operates. Also, the ratio of the number of turns of wire in the coil of the "secondary circuit" of the monitoring system to the number of turns of wire in the coil of the "primary circuit" of the monitoring system is selected so that the "secondary circuit" when open circuited is in electrical resonance at the frequency at which the monitoring system operates during the time that the coil of the "secondary circuit" passes in close proximity to the coil of the "primary circuit" as the wheel rotates. The "secondary circuit" of the monitoring system is devoid of any capacitor component, but, instead depends upon the "effective distributed capacitance" characteristic of the coil of the "secondary circuit" when the "secondary circuit" is open circuited to provide the desired resonant condition in the circuit. The monitoring system of the present invention does not require the use of components in the circuitry that might be jolted out of proper "setting" when the vehicle is driven on rough pavements and, thus, is less susceptible to malfunctioning than systems which do require variable type components.
It will be understood that the embodiments of the present invention described above are susceptible to various modifications, changes and adaptations and that the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
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A monitoring system for motor vehicles that produces a warning signal when the pressure within a tire changes to an unacceptable pressure. The system includes a sensor unit attached on the wheel on which the tire to be monitored is mounted and a second component secured to the vehicle body. The unit mounted to the vehicle body contains a coil wound on a core that is positioned at a location so that as the wheel of the vehicle revolves a second coil wound on a core that forms a part of the sensor unit comes into close proximity to the coil secured to the vehicle body during each rotation of the wheel. When the pressure in the tire changes from a "normal" pressure, a harmonious balance between the two components of the system is disturbed resulting in the triggering of a warning mechanism that alerts the operator of the vehicle that the air pressure in the tire has reached an unacceptable level.
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This application is a continuation of application Ser. No. 08/468212, filed on Jun. 6, 1995, now abandoned, which a divisional application of Ser. No. 08/079310, filed on Jun. 17, 1993, pending.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to lithographic processes, and, in particular, to lithographic processes involving device fabrication.
2. Art Background
Lithographic processes are typically employed in the manufacture of devices such as semiconductor devices. Among the lithographic processes that are available, photolithography is often utilized. Photolithographic processes have the advantage of being suitable for a blanket exposure technique. That is, a material that is sensitive to the exposing light is coated onto a substrate, e.g., a silicon wafer, that is being processed to form a plurality of devices. The coating material, i.e., the resist, is then subjected to light that has been passed through a mask material so that the light reaching the resist produces an image that, after development, yields a desired pattern that is to be transferred into the underlying substrate. Since the exposure occurs simultaneously over an entire device or a number of devices being processed on a substrate, e.g., a silicon substrate, the procedure is considered a blanket exposure.
A blanket exposure procedure is advantageous because it is relatively fast compared to other methods such as the raster scan technique usually employed when the energy used to expose the resist is a beam of electrons. However, generally, resolution obtainable through a blanket exposure with ultraviolet or visible light is somewhat poorer than that achieved with methods such as electron lithography.
Improved resolution with a blanket exposure is achievable by using deep ultraviolet light. One such approach involves a photoresist sensitive to deep ultraviolet radiation containing a compound that produces an acid moiety upon irradiation with such radiation together with a polymer that reacts with the generated acid. Typical acid generator/acid sensitive polymer combinations include an onium salt as the photosensitive acid generator and a polymer such as poly(p-t-butoxycarbonyloxystyrene) as the polymer having a reactive substituent.
The use of an inorganic salt such as the onium salt as the acid generator is not entirely desirable. There is a possibility of contamination of the device being processed by inorganic ionic species from the salt Additionally, ionic acid generators also have the tendency to phase separate from the acid sensitive resin. Therefore, organic acid generators having reasonable sensitivity to deep ultraviolet light for use in a photoresist are quite desirable.
An organic photoacid generator based on ortho nitrobenzyl esters has been disclosed in U.S. Pat. No. 5,135,838, issued Aug. 4, 1992. These photoacid generators do not present the difficulties associated with inorganic salts and have shown excellent properties for use in applications such as chemically amplified resists. Despite the excellent qualities of these photoacid generators, improvement is always desirable.
SUMMARY OF THE INVENTION
A photoacid generator with higher decomposition temperatures allow higher post-exposure baked temperatures that accelerate the rate of photoinduced reaction. Thus, through the use of such higher temperatures, sensitivity of the resist material is enhanced. The thermal stability of nitrobenzyl esters as photoacid generators and, therefore, their sensitivity is increased by employing an α-substituent on the moiety positioned ortho to the nitro group. In particular, structures represented by the formula: ##STR1## where R' is hydrogen or a substituent that enhances steric and/or electronic interaction with the α-substituted substituent R", and where R" is a substituent that has appropriate steric and/or electronic characteristics and where R"', if present, is not critical but is exemplified by substituents such as lower alkyl, e.g., CF 3 , aryl, NO 2 , Cl, and organosulfonyl. Exemplary substituents for R" include CO 2 Et, COCH 3 , CN, and organosulfonyl, while appropriate substituents for R' include H, NO 2 , Cl, CF 3 , alkyl, aryl, and organosulfonyl. Exemplary substituents for Y are alkyls such as lower alkyl, e.g., methyl and trifluoroethyl, aryl such as phenyl or phenyl substituted with R' or R"'. Further substitution is possible provided the substituent is not acidic and is not excessively absorbing of ultraviolet light.
The resulting photoacid generators have decomposition temperatures in the range 164° to 276° C. as compared to a range of 124° to 224° C. for the corresponding materials without an α-substituent. Table 1 gives a comparison between the thermal stabilities with and without stabilizing α-substituents.
TABLE 1______________________________________Thermal decomposition temperature (T.sub.min) of α-substituted2-nitrobenzyltosylate (Ts) or 1,3-benzenedisulfonate (Bis) PAG derivatives. Temperature of de- Temperature of composition decomposition temperature temperature for of PAG's (T.sub.min) PAG's (T.sub.min) with R.sub.α = HR.sub.a, R.sub.α, R.sub.b °C. °C.______________________________________4-CF.sub.3 & 6-NO.sub.2, COCH.sub.3, Ts 235 224H, CN, Ts 211 1246-NO.sub.2, CN, Ts 238 2046-Cl, CN, Ts 265 218H, CO.sub.2 CH.sub.2 CH.sub.3, Ts 164 124H, CO.sub.2 CH.sub.2 C(CH.sub.3).sub.3, Ts 168 1246-NO.sub.2, CO.sub.2 CH.sub.2 CH.sub.3, Ts 261 2046-NO.sub.2, CO.sub.2 CH.sub.2 C(CH.sub.3).sub.3, Ts 267 2046-Cl, CO.sub.2 CH.sub.2 CH.sub.3, Ts 276 2186-Cl, CO.sub.2 CH.sub.2 C(CH.sub.3).sub.3, Ts 276 2186-NO.sub.2, CO.sub.2 CH.sub.2 CH.sub.3, Bis 215 1766-NO.sub.2 CO.sub.2 CH.sub.2 C(CH.sub.3).sub.3, Bis 217 1766-Cl, CO.sub.2 CH.sub.2 C(CH.sub.3).sub.3, Bis 232 1906-Cl, CN, Bis 232 190______________________________________
The higher thermal stability of these materials permits higher post-exposure bake temperatures resulting in enhanced sensitivity without resolution loss for small features. Although the inventive photoacid generating materials are particularly useful in photolithographic processes for device fabrication, they are also sensitive to electrons and x-rays. Therefore, exposure with such sources is not precluded.
BRIEF DESCRIPTION OF THE DRAWINGS
The FIGURE is illustrative of how substituent groups of the composition of the present invention can be selected to attain a desired relative thermal stability.
DETAILED DESCRIPTION
For typical acid sensitive polymers having one acid reactive substituent per monomer unit, acid generator concentrations in the range 0.5 to 50 weight percent, preferably 1 to 20 weight percent, are desirable. Concentrations of photosensitive acid generators less than 0.5 weight percent, although not precluded, are not desirable because resolution and sensitivity are degraded. Concentrations greater than 50 weight percent are undesirable because excessive acid generation tends to produce poor image quality.
As discussed, the photoresists such as a chemically amplified photoresist should employ an organic photoacid generator represented by the formula ##STR2## where R' is a substituent that has an appropriately steric bulk and/or electron withdrawing characteristic, where R" is an α-substituent containing steric bulk hindrance and/or inductive electron withdrawing ability, and where R"', if present, is not critical but is exemplified by substituents such as aryl, alkyl, CF 3 , NO 2 , Cl and organosulfonyl.
Substituents that are characteristic of the R' moiety include H, NO 2 , CF 3 , Cl, alkyl, organosulfonyl, and aryl. Additional substitution on the aromatic ring generally does not affect properties and is not precluded. However, further substituents that are acidic, e.g., that have a pK a lower than 5, should be avoided since they tend to enhance degradation.
Thermal stability is also enhanced by choosing an R" that has appropriate electronic characteristics. The degree of electronic interaction is determined for direct attachment of a substituent as discussed in Steric Effects in Organic Chemistry, Melvin S. Newman, New York, 559 (1956). As defined in this reference, these values may be readily calculated from the σ* for CH 2 --X which measures the electronic effect with an intervening CH 2 group. Generally, it is desirable to have a σ* (--X) of at least 1.5. Thus, even in the absence of a second ortho substituent, (i.e., R'═H) with COR, CO 2 R, SOR, CN, SO 2 R for R" thermal stabilities as high as 210° C. can be achieved for tosylate esters.
Enhancement of thermal stability is also possible by choosing an R" that has appropriate steric characteristics. In particular, the factor used for measuring the steric hindrance is the Charton steric parameter. Such parameters are compiled in texts such as C. Hansch and A. Leo, Substituents Constants for Correlation Analysis in Chemistry and Biology, Wiley Interscience (1979). Generally, it is desirable that the Charton steric parameter for R" be greater than 0.4.
The improved effect associated with employing an α-substituent (steric or electronic) is further enhanced by using a suitable ortho substituent R'. Two factors that affect this enhancement are the steric hindrance of R' and the degree of electron withdrawing characteristic. As discussed in U.S. Pat. Nos. 5,135,838 and 5,200,544 (both of which are incorporated by reference), these two factors are interrelated. The greater the steric hindrance and the greater the electron withdrawing characteristic, generally the higher the decomposition temperature relative to the corresponding nitrobenzyl ester compound in the absence of an R' substituent. The same considerations discussed in the Houlihan patent and patent application supra, concerning the steric effects are applicable to R'. Exemplary of useful R' substituents are alkyl, NO 2 , CF 3 , organosulfonyl, aryl, and Cl.
Even further enhancement is achieved by using α-substituent whose steric bulk has a conformational dependence that can be increased through coulombic repulsion with an electronegative R' substituent. Thus, for example, in using an alkoxycarbonyl substituent for R", two orientations of this substituent are possible, υ min (0.50) and υ max (1.45) which respectively minimize and maximize steric interaction to the ortho nitro group that attacks during thermal decomposition. (υ min and υ max are defined in "Upsilon Steric Parameter-Definition and Determination", in Steric Effects in Drug Design, M. Charton and I. Motoc, Eds., Springer-Verlag, New York, p. 57 (1983).) Normally, in the absence of an electronegative R' group, the conformation offering minimal steric interaction is preferred. However, if an electronegative R' group is present, then coulombic repulsions forces the R" substituent to adopt the conformation offering larger steric interaction. To induce this increased steric bulk, R" should, as previously discussed, be chosen to have a σ* (--X) of at least 1.5 and a Charton steric parameter of greater than 0.40. Other examples of R" which offer a similar combination of a coulombic effect coupled with a large conformational steric dependence are carbonyl esters, NO 2 , CO 2 , amides, and COCF 3 . In general, these substituents should be chosen to be planar π bounded groups in which either conformation offering σ min to an attacking nitro group causes a coulombic repulsion due to an electronegative moiety.
Increasing thermal stability is accomplished by decreasing the tendency of the sulfonate to undergo nucleophilic reaction by the oxygen of the nitro group. As a result, the increase in thermal stability is accompanied by an increased resistance to solvolysis, hydrolysis, and reactions with other nucleophilic moieties present during processing. Taking into account the above discussion concerning steric, electronic, and coulombic effects of R' and R" and possible resonance effects of the R" substituent, an empirical plot allowing guidance in choosing an acid generator with a desired relative thermal stability is achievable (FIG. 1). This is accomplished by calculating σ(α) constants incorporating both resonance and inductive effects. The calculation uses as its basis literature values of σ R and σ I calculated by Charton for attachment of substituents at an aromatic ring. Progress in Physical Organic Chemistry, M. Charton in Electrical Effect Substituent Constants For Correlation Analysis, Editor R. W. Taft, Interscience Publication, John Wiley & Sons, New York (1981) p. 119.
Also, an estimate is made of combined resonance, inductive effects for α-substituents by defining the following: σ(α)=(σ R /σ I )σ*(α)+σ*(α). This resonance interaction is a function of the overlap of the π orbitals of the α-substituent with that of σ of the benzyl carbon as it undergoes nucleophilic interaction with the oxygen atom of the attacking vicinal nitro group.
Apart from improving thermal stability, it is possible to use α-substituents to improve other properties of the photoacid generator. For instance, for α-alkoxycarbonyl groups, (i.e., R"=CO 2 R, where R is an alkyl moiety), increasing the size of the alkyl group from ethyl to noepentyl greatly improves the solubility in certain less polar spinning solvents such as 3-ethylethoxypropionate. Also, it is possible to introduce moieties such as a dissolution inhibitor removable through acidolytic cleavage by using an appropriately substituted α-substituent. For example, in the case of R"=CO 2 R, when R=t-butyl or t-amyl, thermal stability is improved relative to that over presently available acid generators through introduction of similar groups at the 2-nitroaryl moiety in compounds such as 4-butoxycarbonyl-2,6-dinitrobenzyl tosylate (i.e., >150° C.) such as described by F. M. Houlihan, E. Chin, O. Nalamasu, and J. M. Kometani in Proc. Polym. Mater. Sci. Eng., 66, 38 (1992).
It is possible to synthesize photoacid generators involved in the invention by a variety of routes. For example, one route involves ##STR3## An alternate route involves ##STR4## Additionally, a third suitable route includes the steps of ##STR5##
The following examples are illustrative of suitable processes for synthesizing the acid generators and for use in the invention.
EXAMPLE 1:
Synthesis of α-substituted photoacid generators (PAG's)
Synthesis of 2,6-dinitromandelonitrile
A saturated solution of sodium bisulfite (126 mL) was added to a suspension of 2,6-dinitrobenzaldehyde (30 g, 152.0 mmol) in water (300 mL). This mixture was allowed to stir for 2 hours after which time almost all solids dissolved. The fine particles remaining were filtered off. A sodium cyanide solution (45 g NaCN>180 mL H 2 O) was then dropped into the filtered solution. The precipitate formed was filtered and washed with cold water giving a yield of 28 g (82%).
Synthesis of 2,6-dinitromandelic acid
2,6-dinitromandelonitrile (28.0 g, 126 mmol) was dissolved in 428 mL of concentrated HCl. This mixture was heated at reflux for 5 hours. It was then cooled, poured into ice, extracted with ether and dried over MgSO 4 . The ether layer was filtered and concentrated to 100 mL. Carbon tetrachloride was added to the ether layer. The resulting precipitate was collected to give a yield of 22 g (72%).
Synthesis of neopentyl 2,6-dinitromandelate
2,6-dinitromandelic acid (4.00 g, 16.5 mmol) was added to an excess of neopentyl alcohol (20.0 g, 227 mmol) melted in a round bottom flask. To this solution was added 5 drops of H 2 SO 4 and it was heated to reflux for 3 hours. The excess neopentyl alcohol was removed under reduced pressure, and the residue was purified by column chromatography over silica gel (60-200 mesh) using methylene chloride/hexane (1:1) as the eluant. The yield after two recrystallizations from CHCl 3 /petroleum ether was 3.8 g (74%).
Synthesis of α-(neopentoxycarbonyl)-2,6-dinitrobenzyl tosylate
Neopentyl 2,6-dinitromandelate (1.50 g, 4.80 mmol) and p-toluenesulfonyl chloride (1.00 g, 5.28 mmol) were mixed in dry acetone (50 mL) under argon. Dicyclohexylamine (0.957 g, 5.28 mmol) was added slowly to the reaction at 0° C. The mixture was stirred at room temperature for 2 hours at which time the reaction was shown to be complete by thin-layer chromatography (tlc). The acetone was then removed by evaporation under vacuum. The residue was put through a silica gel (60-200 mesh) column using methylene chloride/hexane (1:1) as the eluant. Recrystallization from CHCl 3 /petroleum ether gave a yield of 2 g (89%).
Synthesis of bis α-(neopentoxycarbonyl)-2,6-dinitrobenzyl! 1,3-benzenedisulfonate
A solution consisting of 1,3-benzenedisulfonyl chloride (0.544 g, 1.98 mmol) and the alcohol (1.24 g, 3.96 mmol) was prepared under nitrogen in dry acetone (15 mL). Dicyclohexylamine (0.58 g, 3.96 mmol) diluted with acetone (10 mL) was added slowly to the reaction mixture at 0° C. which was then stirred for 1 hour. The dicyclohexylamine hydrochloride salt was filtered off and the acetone solution was concentrated under vacuum until most of the solvent was removed. The residue was purified by column chromatography over silica gel (60-200 mesh) using CH 2 Cl 2 /hexane (1:1) as the eluant. Recrystallization from CHCl 3 /petroleum ether gave a yield of 1.24 g (76%).
Synthesis of α-(ethoxycarbonyl)-α'-(acetyl)-4-(trifluoromethyl)-2,6-dinitrotoluene
Sodium hydride (1.77 g, 73.9 mmol) was placed in a suspension in dry freshly distilled THF (20 mL) under argon. Ethyl acetoacetate (9.62 g, 73.9 mmol) was introduced slowly cooling the stirred reaction mixture with an ice bath during addition. When H 2 ceased to evolve, 4-chloro-3,5-dinitrobenzotrifluoride (10.00 g, 36.96 mmol) dissolved in THF (20 mL) was added slowly to the reaction mixture and it was allowed to stir for 2 hours. The THF solution was washed with dilute H 2 SO 4 (10%) until acidic to pH paper then dried over MgSO 4 , filtered, and concentrated under vacuum until most of the solvent was removed. The residue was put through a column of silica gel (60-200 mesh) using CH 2 Cl 2 /hexane (1:1) as the eluant. Recrystallization with ethanol/petroleum ether gave a yield of 4.7 g (35%).
Synthesis of α-(acetyl)4-(trifluoromethyl)-2,6-dinitrotoluene
α-(Ethoxycarbonyl)-α'-(methylcarbonyl)-4-(trifluoromethyl)-2,6-dinitrotoluene (1.00 g, 2.74 mmol) was refluxed with 50% acetic acid (22 mL), concentrated H 2 SO 4 (45 drops) for 12 hours. The reaction was cooled to room temperature and the precipitate that formed was filtered and washed with petroleum ether. The yield was 0.73 g (91%).
Synthesis of α-(acetyl)4-(trifluoromethyl)-2,6-dinitrobenzyl tosylate
α-(Acetyl)4-(trifluoromethyl)-2,6-dinitrotoluene (5.00 g, 17.10 mmol) was heated to 80° C. for 10 minutes under nitrogen. Hydroxy(tosyloxy) iodobenzene (13.40 g, 34.18 mmol) was then added slowly keeping the temperature constant at 80° C. The reaction mixture was allowed to stir for 1 hour, carefully avoiding overheating. After cooling, the reaction mixture was purified by column chromatography over silica gel (60-200 mesh) using CH 2 Cl 2 /hexane (1:1) as the eluant. Recrystallization with chloroform/petroleum ether gave 2 g (25%) of pure product.
EXAMPLE 2:
Lithographic Evaluation
Exposures were done using a Laserstep® prototype deep-UV exposure tool (NA=0.35, 5×optics) operating at 248 nm.
The photoresist solutions for the initial screening of PAG's derivatized as the tosylates were prepared and processed as follows: Poly(4-(t-butoxycarbonyloxy)styrene-sulfone) (3:1, M W =150,000, D=1.9) PTBOCSS (4 g) and a α-substituted-2-nitrobenzyl ester (6.0 mole % relative to the polymer's pendant t-BOC groups) were dissolved in 1,2-dimethoxyethane (24 mL). The solutions were filtered through a series of 1.0, 0.5, and 0.2 μm Teflon filters (Millipore Inc.). For comparison, a photoresist solution was prepared in the same way with 2,6-dinitrobenzyltosylate as the PAG component. Photoresist films were spin coated (2,300 r.p.m.) onto hexamethyldisilazane vapor primed silicon substrates, and prebaked at 105° C. for 60 s. After exposure, the substrates were post-exposure baked at 115° C. for 30 s. Development was done in 0.17N tetramethylammonium hydroxide (TMAH) for 30 s. The results are summarized in Table 2.
TABLE 2__________________________________________________________________________Lithographic Sensitivity.sup.a of Resists Formulated with PTBOCSS andα-SubstitutedTosylate (Ts) PAG's. ##STR6## SensitivityLithographic maxλ Litermaxε Liter248ε ΦR.sub.a, R.sub.α mJ/cm.sup.2 nm mole.sup.-1 cm.sup.-1 mole.sup.-1 cm.sup.-1 248__________________________________________________________________________4-CF.sub.3 & 6-NO.sub.2, COCH.sub.3 50 222 25,700 9,300 0.116-NO.sub.2, CN 130 229 25,700 9,900 0.046-NO.sub.2, CO.sub.2 CH.sub.2 CH.sub.3 56 228 27,900 12,000 0.086-NO.sub.2, CO.sub.2 CH.sub.2 C(CH.sub.3).sub.3 66 227 28,500 12,000 0.076-NO.sub.2, H 30 227 25,700 9,300 0.166-CF.sub.3, H 110 221 28,520 5,100 0.11__________________________________________________________________________ .sup.a For preparation and processing of resists see the experimental lithographic section, first procedure.
The photoresist solutions for the secondary screening of PAG's derivatized as the tosylates or the 1,3-benzenedisulfonates were prepared and processed in the same way as described above except that resists in which the loading of α-substituted ester was decreased to 2.5 mole % were also prepared. For comparison, resist solutions with 2-(trifluoromethyl)-6-nitrobenzyl tosylate, and bis(2-(trifluoromethyl)-6-nitrobenzyl) 1,3-benzenedisulfonate were prepared at the same molar loading of PAG and processed as described above. The lithographic results are given in Table 3.
TABLE 3__________________________________________________________________________Absorbance and lithographic.sup.a behavior of resists formulated withPTBOCSS and α-substituted tosylate(Ts) or 1,3-benzenedisulfonates (Bis) PAG derivatives.R.sub.a, R.sub.α, R.sub.b ##STR7## mole %PAG °C.TemperaturePEB AU/μmAbsorbance secondsPEB Time mJ/cm.sup.2SensitivityLithographic mJ/cm.sup.2pairsline/space(μm) esolution.lines and spacesachieve given equalDose needed to__________________________________________________________________________6-NO.sub.2, H Ts 6.0 115 0.44 30 30 80(0.40)6-CF.sub.3, H Ts 6.0 115 0.23 30 110 210(0.60)6-NO.sub.2, CO.sub.2 CH.sub.2 C(CH.sub.3).sub.3, Ts 6.0 115 0.44 30 66 170(0.50)6-CF.sub.3, H Bis 6.0 115 0.40 30 14 30(0.35)6-NO.sub.2, CO.sub.2 CH.sub.2 CH.sub.3, Bis 6.0 115 0.70 30 22 44(0.50)6-NO.sub.2, CO.sub.2 CH.sub.2 C(CH.sub.3).sub.3, Bis 6.0 115 0.68 30 24 60(0.50)6-NO.sub.2, CO.sub.2 CH.sub.2 CH.sub.3, Bis 2.5 115 0.41 30 80 >100.sup.c(0.50)6-NO.sub.2, CO.sub.2 CH.sub.2 CH.sub.3, Bis 2.5 125 0.41 30 40 66(0.50)6-NO.sub.2, CO.sub.2 CH.sub.2 C(CH.sub.3).sub.3, Bis 2.5 115 0.37 30 90 >100(0.50)6-NO.sub.2, CO.sub.2 CH.sub.2 C(CH.sub.3).sub.3, Bis 2.5 125 0.37 30 38 76(0.50)6-NO.sub.2, H Bis 2.5 115 0.25 30 85 >100(0.50)6-NO.sub.2, H Bis 2.5 125 0.25 30 30 65(0.50)__________________________________________________________________________ .sup.a For preparation and processing of resists see the experimental lithographic section, second procedure. b) The line thickness increases going towards the substrate and some residue is observed in the spaces. .sup.c No effort was made to determine the resolution dose or resolution capability when doses >100 mJ/cm.sup.2 were required for resolution.
Final testing was done with resist solutions formulated with Poly(4-(t-butoxycarbonyloxy)styrene-4-(acetoxy)styrene-sulfone), (1.8:1.2:1, M W =105,000, D=1.6-1.7) PTBOCSASS (4 g) and various α-alkoxycarbonyl-2,6-dinitrobenzyl 1,3-benzendisulfonates (2.5 and 1.5% mole loading) dissolved in diglyme (24 mL). Preexposure baked was done as before, while postexposure bake temperature and time Were varied as described in Table 4, parts 1-3.
TABLE 4__________________________________________________________________________Absorbance and lithographic.sup.a behavior of resists formulated withPTBOCSASS and α-substituted1,3-benzenedisulfonates (Bis) PAG derivatives.R.sub.a,R.sub.α, R.sub.b ##STR8## mole %PAG °C.TemperaturePEB AU/μmAbsorbance secondsPEB Time mJ/cm.sup.2SensitivityLithographic mJ/cm.sup.2pairsline/space(μm)res olution.lines and spacesachieve given equalDose needed__________________________________________________________________________ topart 16-CF.sub.3,H Bis 2.5 115 0.37 30 92 >100.sup.c(0.35)6-CF.sub.3,H Bis 2.5 115 0.37 60 62 >100(0.35)6-CF.sub.3,H Bis 2.5 125 0.37 60 46 lost.sup.b(0.35)6-CF.sub.3,H Bis 2.5 135 0.37 60 30 lost(0.35)6-CF.sub.3,H Bis 1.5 115 0.29 30 >100 >100(0.35)6-CF.sub.3,H Bis 1.5 115 0.29 60 >100 >100(0.35)6-CF.sub.3,H Bis 1.5 125 0.29 60 72 lost(0.35)6-CF.sub.3,H Bis 1.5 135 0.29 60 46 lost(0.35)part 26-NO.sub.2, CO.sub.2 CH.sub.2 CH.sub.3, Bis 2.5 115 0.51 30 92 >100.sup.c(0.35)6-NO.sub.2, CO.sub.2 CH.sub.2 CH.sub.3, Bis 2.5 115 0.51 60 68 >100(0.35)6-NO.sub.2, CO.sub.2 CH.sub.2 CH.sub.3, Bis 2.5 125 0.51 60 44 92(0.35)6-NO.sub.2, CO.sub.2 CH.sub.2 CH.sub.3, Bis 2.5 135 0.51 60 28 54(0.35).sup.b6-NO.sub.2, CO.sub.2 CH.sub.2 CH.sub.3, Bis 1.5 115 0.43 30 >100 >100(0.35)6-NO.sub.2, CO.sub.2 CH.sub.2 CH.sub.3, Bis 1.5 115 0.43 60 >100 >100(0.35)6-NO.sub.2, CO.sub.2 CH.sub.2 CH.sub.3, Bis 1.5 125 0.43 60 66 >100(0.35)6-NO.sub.2, CO.sub.2 CH.sub.2 CH.sub.3, Bis 1.5 135 0.43 60 40 90(0.35).sup.bpart 36-NO.sub.2, CO.sub.2 CH.sub.2 C(CH.sub.3).sub.3, Bis 2.5 115 0.50 30 >100 >100.sup.c(0.35)6-NO.sub.2, CO.sub.2 CH.sub.2 C(CH.sub.3).sub.3, Bis 2.5 115 0.50 60 76 >100(0.35)6-NO.sub.2, CO.sub.2 CH.sub.2 C(CH.sub.3).sub.3, Bis 2.5 125 0.50 60 54 98(0.35)6-NO.sub.2, CO.sub.2 CH.sub.2 C(CH.sub.3).sub.3, Bis 2.5 135 0.50 60 34 62(0.35).sup.b6-NO.sub.2, CO.sub.2 CH.sub.2 C(CH.sub.3).sub.3, Bis 1.5 115 0.34 30 >100 >100(0.35)6-NO.sub.2, CO.sub.2 CH.sub.2 C(CH.sub.3).sub.3, Bis 1.5 115 0.34 60 >100 >100(0.35)6-NO.sub.2, CO.sub.2 CH.sub.2 C(CH.sub.3).sub.3, Bis 1.5 125 0.34 60 70 >100(0.35)6-NO.sub.2, CO.sub.2 CH.sub.2 C(CH.sub.3).sub.3, Bis 1.5 135 0.34 60 54 98(0.35).sup.b__________________________________________________________________________ .sup.a For preparation and processing of resists see the experimental lithographic section, third procedure. .sup.b Lines show profile degradation resulting in inverted line profiles .sup.c No effort was made to determine the resolution dose or resolution capability when doses >100 mJ/cm.sup.2 were required for resolution.
Development was done in 0.26N TMAH for 60 s. Resist solutions formulated with bis(2-(trifluoromethyl)-6-nitrobenzyl) 1,3-benzenesulfonate were also prepared and evaluated as above.
All thickness measurements were obtained on a Nanospec film thickness gauge (Nanometrics, Inc.) or a Dektak model IIA profilometer. Scanning electron (SEM) cross-sections were obtained on a JEOL scanning electron microscope.
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Photoacid generators advantageous for use in applications such as photoacid generators used in chemically amplified resists are disclosed. These compounds are based on an ortho nitro benzyl configuration employing an α substituent having high bulk, steric characteristics, and electron withdrawing ability. The enhanced efficacy is particularly found in compounds both having a suitable α substituent and a second ortho substituent with large electron withdrawing and steric effects.
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BACKGROUND OF THE INVENTION
This invention is directed to the art of media handling, in general, and methods and apparatus for converting non-continuous media handling devices into continuous media handling devices, in specific. Typically, the media comprises sheet material in the form of paper sheets.
A common method of sheet handling comprises the use of a high capacity top-sheet pick-up device, commonly known as a high capacity top-sheet feeder (hereinafter "HCTSF") to feed sheets from a vertically disposed stack of sheets found on a incrementally vertically movable table, to a down stream location. In particular, the uppermost sheet of the stack is picked off (i.e., separated), using a top-sheet pick-up device, for example, a vacuum pick-up located in the HCTSF, and the table then constantly and incrementally raised to maintain the uppermost sheet close to the top-sheet pick-up device for separation and removal of the top-sheet from the stack.
We have found problems with this arrangement. For example, when the stack of sheets on the table has been completely fed, the HCTSF (and any downstream machinery) must be stopped, the table lowered, a new stack of sheets placed on the table, and the HCTSF (and any downstream machinery) re-started. Thus, during this stack replenishment period, no sheets are being fed to the downstream machinery, rendering the HCTSF both non-continuous, and inefficient, in operation.
Furthermore, in this arrangement, the stack of sheets on the movable table is often in the range of 12-18 inches high. Stacks this high become unpredictable and hard to manipulate. For example, typically, the toner (or ink) distribution on sheets is uneven because the sheets will not have printed matter entirely thereon, i.e., the sheet will not be totally black. Thus, each individual sheet will be thicker in the area on which it has printed matter. As more and more sheets are stacked upon each other, these thicker portions multiply in effect to the point where the top surface of the sheet stack becomes uneven (non-planar). This makes it hard for a rigidly mounted top-sheet pick-up device to properly separate the top-sheet. Accordingly, a method by which this problem could be solved was searched for. While the prior art solution involved the manipulation of carefully positioned weights on the top of the sheet stack, this was a difficult solution to implement and a better solution was needed.
Accordingly, there is room for improvement within the art.
OBJECTS OF THE INVENTION
It is an object of the invention to provide a horizontal feed table and method for its use that allows for continuous feeding of sheets to a downstream operation.
It is a further object of the invention to provide a horizontal feed table and method for its use that minimizes the toner addition effects caused by large stack heights.
It is further object of the invention to provide a horizontal feed table and method for its use that minimizes the toner addition effects caused by large stack heights without requiring the difficult manipulation of weights on the top of the sheet stack.
It is a further object of the invention to provide a method by which a device that is intended to feed sheets in a non-continuous manner to a downstream location can be converted into a device that feeds sheets in a continuous manner to the downstream location.
These and other objects of the invention are achieved by a horizontal feed table, comprising: vertically disposed legs; a horizontal conveyor table supported by the legs and having front and rear ends; a conveyor spanning the length of the conveyor table; a conveyor drive for driving the conveyor; an angle bracket attached to, and extending upwardly out from, the front end of the conveyor table, the angle bracket having slots therein; stop members positioned immediately in front of the angle bracket on a side thereof opposite from the conveyor table; and sensors positioned next to the stops, the sensors in communication with the conveyor drive.
These and other objects of the invention are further achieved by a method of feeding sheets, comprising the steps of: providing a top-sheet pick-up device; providing a horizontal feed table for feeding stacks of sheets to the to-sheet pick-up device; placing a first reverse-shingled stack of sheets onto the feed table; feeding the first reverse-shingled stack of sheets in a direction towards the top-sheet pick-up device; detecting when the uppermost sheets of the reverse-shingled stack of sheets are positioned under the top-sheet pick-up device; separating the upper-most sheet from the reverse-shingled stack of sheets using the top-sheet pick-up device; and using the horizontal feed table to move additional sheets into position under the top-sheet pick-up device when no sheet is detected under the top-sheet pick-up device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a perspective view of an exemplary embodiment of a horizontal feed table capable of achieving the goals according to the invention.
FIG. 1B is a perspective view of an exemplary embodiment of a horizontal feed table capable of achieving the goals according to the invention and with the conveyor belt omitted to show the details of the conveyor.
FIGS. 2A, 2B are perspective views of the exemplary horizontal feed table of FIGS. 1A, 1B when mated with a HCTSF.
FIG. 3 is a detailed perspective view of the end of the exemplary horizontal feed table shown in FIGS. 1A, 1B that is positioned under the pick-up of the HCTSF.
FIGS. 4A, 4B, 4C show how the horizontal feed table according to the invention registers sheet stacks.
DETAILED DESCRIPTION OF THE INVENTION
With reference to the drawings, a horizontal feed table and method of its use that meets and achieves the various objects of the invention set forth above will now be described.
An exemplary embodiment of a horizontal feed table 100 according to the invention is shown in FIG. 1A. Horizontal feed table 100 comprises horizontal table 110 supported by legs 120 mounted to casters 125. Casters 125 allow horizontal feed table 100 to be rolled into position inside a HCTSF, as will be described below with reference to FIGS. 2A, 2B. Conveyor belt 130 spans the length of horizontal table 110 and is wrapped around end pulleys 135, 140 (FIG. 1B). Take-up pulley 145 (FIGS. 1B, 3) increases the amount by which conveyor belt 130 wraps around pulley 135, as is known in the art.
Mounted to top surface 115 of horizontal table 110 are adjustable first side guides 150 and adjustable second side guides 155, whose functions will both be described below. The lateral positions of adjustable side guides 150, 155, are adjustable with respect to the central axis of conveyor belt 130 to account for sheets of different widths. Also mounted to top surface 115 of horizontal table 110 is electronic control panel C for operating and controlling horizontal feed table 100. The functions available by control panel C can vary according to need and are conventionally implementable.
The front end of horizontal feed table 100 is shown in detail in FIG. 3. By front end, Applicants mean the end of horizontal feed table 100 that will be mated with, or inserted into the HCTSF and attached thereto by use of mounting brackets B (FIG. 1A). This front end of horizontal feed table 100 is narrower than the rest of horizontal feed table 100 so that the front end of the horizontal feed table 100 can be inserted in the narrow opening of the HCTSF (FIG. 2B).
DC motor 200 is mounted under horizontal table 110 and drives pulley 140 through pulleys 210 and drive belt 220. Motor 200 and pulleys 210 and belt 220 are mounted on opposite sides of a vertical support plate 230.
Also mounted to top surface 115 of horizontal table 110 are vertical pillars 250. Vertical pillars 250 support beams 255 that are typically parallel to conveyor belt 130 and used to support overhead rollers 265 over top surface 115. Overhead rollers 265 are supported by beams 255 by use of arms 262, longitudinal member 263, and friction bearings 264. Friction bearings 264 allow the distance between overhead rollers 265 and the front end of horizontal feed table 100 to be varied dependent upon the length of the sheet being fed. Overhead rollers 265 provide a downward (normal) force equal to the weight of overhead rollers 265, i.e., overhead rollers 265 are not spring loaded, on the sheets being fed to prevent double feed into the HCTSF. While the use of overhead rollers 265 is preferred because they provide for less potential for toner or ink smudging, etc., other means are acceptable.
At the very front of horizontal feed table 100 are stops 300, sensors 305, and angle bracket 310 having slots 315 therein. Sensor 305 is electronically connected to motor 200 and control panel C by conventional circuitry so that when sensor 305 does not detect a sheet, motor 200 is on, and when sensor 305 detects a sheet, motor 200 is off. Typically, sensor 305 will be an optical sensor that detects a sheet when covered and detects no sheet when uncovered. As shown in FIGS. 4A, 4B, angle bracket 310 registers and shingles a sheet stack S as it is moved in the direction of the arrow and into contact with angle bracket 310. Stops 310 prevent sheets from stack S from traveling too far into the HCTSF and causing a jam. Slots 315 allow air A from conventional blowers B that are part of HCTSF H to be blown towards the registered and shingled stack of sheets (FIG. 4C).
Having described the structure of horizontal feed table 100, its method of operation will now be described. When a facility determines that the use of the HCTSF in its normal non-continuous configuration is too slow and inefficient, it is anticipated that they will seek to convert the HCTSF to a continuous operating device by merely acquiring horizontal feed table 100 according to the invention. Accordingly, the invention is intended to be a retro-fit and does not require the purchase of a different HCTSF.
Prior to the conversion, as shown in FIGS. 2A-B, feed table T of HCTSF H is lowered to a position under which horizontal table 110 will span. Then the motor (not shown) that normally raises table T will be disengaged in any number of conventional ways, such as by disconnecting the electrical power leading to the motor. This can be done because table T is no longer needed due to the fact that sheet material will be fed to HCTSF H by horizontal feed table 100.
Horizontal feed table 100 is rolled, using casters 125, into the opening of HCTSF H. Using brackets B, the HCTSF and the horizontal feed table 100 are rigidly connected together and then electrical power and a control line is fed to the horizontal feed table 100 from the HCTSF so that the two units can communicate with one another. Making these electrical and mechanical connections only requires ordinary skill in the art. Horizontal feed table 100 is now ready for use.
An operator, either human or automated, then places a stack of sheets onto conveyor belt 130. This stack of sheets is squared (width-wise) against first side guide 150, which will have been previously adjusted to its proper position based upon the width of the sheets in the stack. The stack of sheets will normally be about 3/4 high. While it would be preferred to reverse-shingle the stack of sheets (top of stack leads bottom of stack) by approximately 1/32, this is not critical due to the shingling adjusting effect achieved by angle bracket 310 (see description above and FIGS. 4A-C).
At start-up, sensor 305 will not detect a sheet and therefor motor 200 will be turned on and the sheet stack fed by conveyor belt 130 towards the front of horizontal feed table 100, between side guides 150, 155, and under overhead rollers 265, both of which are now positioned inside of the HCTSF. The sheet stack will hit angle bracket 310 and be registered thereby. When sensor 305 detects a portion of the sheet stack, motor 200 will be shut off. Typically, it is foreseen that sensor 305 will detect the uppermost portion of the sheet stack. The sheets will now be ready for feeding via the HCTSF.
Blowers B incorporated into the HCTSF will be turned on via a control signal and air emitted therefrom will fan the uppermost few sheets of the sheet stack to reduce the friction there between (FIG. 4C). The stack remains registered because it is held between side guides 150, 155. The uppermost sheet of the stack will then be fed into the HCTSF by the HCTSF's top-sheet pick-up device, e.g., an overhead conveyor, typically in the form of an overhead vacuum conveyor O (FIG. 2B). As a portion of the uppermost sheet is pulled into the HCTSF, overhead rollers 265 will apply a normal force equal to their weight to the next uppermost sheet. This normal force will exceed the friction force between the sheet being fed by the overhead conveyor and this next uppermost sheet. Thus, overhead rollers 265 in combination with the sheet fanning caused by blowers B substantially prevent double feed.
After a few of the uppermost sheets are fed into the HCTSF, sensor 305 no longer detects a sheet. This activates motor 200 and brings more sheets into position for feeding into the HCTSF as described above.
After a portion of the stack has been fed into the HCTSF, it becomes time to replenish the stack. With the instant invention, this can be achieved without stopping the HCTSF or any downstream machinery. To achieve this goal, the operator, either human or automated, lifts the rear end of the original stack being fed from and inserts another stack under it and towards the front end of horizontal feed table 100. This is not difficult to do since the low stack height results in a fairly light stack. Thus, as conveyor 130 continues to move the original stack towards angle bracket 310, it simultaneously brings the new stack into position and allows for sheets to be fed therefrom after the original stack is depleted. By repeatedly following these steps, sheet replenishment becomes a continuous cycle and neither the HCTSF nor any downstream machinery need never be shut off. This saves the machine operator about 20 minutes per one hour of machine operation time. This time period is slow enough for a human or automated operator to handle, yet fast enough to assure that HCTSF is never completely emptied to the point that it or downstream machinery must be shut down.
The above description is directed to horizontal feed table and method for its use. However, it will be understood that various details of the invention may be changed without departing from the scope of the invention. Furthermore, the foregoing description is for purpose of illustration only, and not for purpose of limitation, as the invention is defined by the following, appended claims.
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In a method of continuously feeding sheets, a top-sheet pick-up device and a feed table for feeding stacks of sheets to the pick-up device are provided. A stack of sheets are placed on the feed table and fed towards the pick-up device. When it is detected that the uppermost sheets are positioned under the pick-up device, the pick-up device separates the uppermost sheet from the stack. The feed table continues to feed the stack toward the pick-up device by moving additional sheets into position under the pick-up device when no sheet is detected under the pick-up device. Also provided are a feed table including an angle bracket for registering and shingling sheets, and a method of converting a non-continuous high-capacity top-sheet feeder having a top-sheet pick-up device into a continuous high-capacity top-sheet feeder.
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RELATED APPLICATION
[0001] Applicant claims the benefit of the filing date of Sep. 4, 2008 of its U.S. provisional patent application Ser. No. 61/190,949, which application is expressly incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates to pouch forming, filling and sealing, and more particularly to preparing and handling pouches and the mouths thereof to enhance subsequent opening for filling, whether in bandolier or individual pouch applications.
BACKGROUND OF THE INVENTION
[0003] Pouches are formed from a variety of relatively thin materials, typically by folding an elongated web, then transversely sealing together the folded plies at intervals (corresponding to pouch pitch) to form sealed side seams with open mouths therebetween at the pouch tops. As so prepared, an indefinite length or “bandolier” of serially attached pouches is formed. Such a bandolier can be directed as a train of pouches through opening, filling, sealing and cutting apparatus or stations, or individual pouches can be cut, one from the other, gripped at the side seams and transported as individual pouches through opening, filling and sealing operations. One such apparatus for so handling individual pouches is applicant's co-pending U.S. patent application Ser. No. 11/688,205, filed Jan. 29, 2007, published on Aug. 9, 2007 under No. US 2007/0180794, both application and publication incorporated herein by reference as if fully set out herein.
[0004] Because of web stiffness characteristics, including the relative flimsy or thin nature of typical pouch material, the pouches do not open robustly when air is directed at the “mouth” of the pouch. The web will sometimes fold over on itself and not open due to the air not being able to find a path into the mouth. Another problematical situation is presented when the pouch opens but re-closes immediately after being opened due to web “memory” which is not effectively resisted by a material stiffness too low to overcome such memory.
[0005] Prior methods of pouch opening are varied. One such method biases the web material at the mouth of the pouch. A forming guide “curls” the web on one or both sides of the pouch mouth such that the internal pouch material surfaces flair away from each other. The result is a lead-in or path into the pouch for the pressurized air that will do the opening. The guide work required for this method is difficult to setup and can result in a wrinkle being introduced into the web.
[0006] Another method involves making one side of the pouch, termed a “lip”, higher than the other. This configuration allows the pressurized air to have a surface that helps separate and direct the air into the pouch.
[0007] Neither of these methods addresses the issue of material stiffness and memory which may result in the pouch re-closing.
[0008] Accordingly, it is desired to enhance the opening of pouches, presented either in a train or bandolier or as cut and individually presented continuously or intermittently to pouch opening stations.
[0009] It is further desired to provide improved pouch handling apparatus for producing pouches whose mouths are more reliably and consistently opened for filling.
[0010] It is further desired to provide improved pouch structure for enhancing reliable and consistent mouth opening for filling.
SUMMARY OF THE INVENTION
[0011] A preferred embodiment according to the invention contemplates crimping the pouch plies in a mouth region, thus increasing the stiffness of the pouch at its mouth, which tends to robustly open and remain open when an opening airstream is applied thereto.
[0012] One embodiment of the invention includes a nip defined by a pair of operably opposed rollers with each roller having raised surfaces that run parallel to each other and are located about the circumference of preferably each roller. The doubled pouch web is passed between the rollers and is “crimped” between them under some pressure, which may be supplied by biasing one or both rollers into the nip such as applied by a spring. The rollers can be driven or non-driven. The action of passing the web, in particular the region of pouch mouth, through the nip between the rollers imparts a crimp pattern comprising a series of ridges and valleys into the web at the mouth area or region and preferably just below the upper edges of the mouth. These ridges and valleys cause each ply of the affected web at the pouch mouth to have a greater stiffness much like a corrugated material. This increased stiffness resists the otherwise tendency of the pouch plies to fold over and obstruct the opening action of the air when pouches are presented to an opening station. This stiffness allows the pouch tops to “pop” open robustly when opening air is blown into the pouch, and effectively resists any ply memory which may tend to urge the mouth to prematurely close. In addition, the web will naturally curl outwardly on both sides of the pouch mouth above the crimp and provide a pathway for the pressurized opening air. Once opened, the now higher material stiffness overcomes the tendency of the pouch to re-close.
[0013] This method and apparatus is easy to setup, do not impart un-wanted wrinkles into the web, and the apparatus can be disengaged by simply pulling or moving the rollers away from the web. The method can also be used with or without an extended “lip” or ply extension from one of the pouch plies above or within the crimp.
[0014] Other variations of this method and apparatus are possible. The use of one roller with a back-up surface defining a nip is possible as well as using two or more rollers in tandem or individually sequencing one after each other. For example, one roller could be oriented on one side of a pouch with another crimping roller or rollers downstream on another side of the pouch. Additionally, the rollers can be smooth with no crimp pattern to achieve only the “curl” at the mouth and to limit the amount of induced stiffness.
[0015] These and other objects and advantages will be readily appreciated from the following detailed written description and from the drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is an elevational view of pouches in a pouch bandolier running through a crimping nip according to the invention;
[0017] FIG. 1A is a diagrammatic plan view along lines 1 A- 1 A of FIG. 1 of a nip according to the invention, and defined by two rollers having a crimping pattern;
[0018] FIG. 1B is a diagrammatic plan view of a nip according to the invention defined by two rollers, one having a crimping pattern in a peripheral surface and one a smooth peripheral surface;
[0019] FIG. 1C is a diagrammatic plan view of a nip according to the invention having two rollers, each with a smooth peripheral surface;
[0020] FIG. 2 is a perspective view of the invention as shown in FIGS. 1 and 1A ;
[0021] FIG. 3 is a perspective view of an individual pouch formed as in FIGS. 1 , 1 A and 2 ;
[0022] FIG. 4 is a diagrammatic cross-sectional view taken along lines A-A of FIG. 2 but modified to show one crimp pattern surface and one smooth surface of opposed rollers as in FIG. 1B ;
[0023] FIG. 5 is a diagrammatic cross-sectional view also taken along lines A-A of FIG. 2 but modified to illustrate a nip formed by two smooth surface opposed rollers as in FIG. 1C ; and
[0024] FIG. 6 is a perspective view similar to FIG. 3 but illustrating a pouch having mouth edges curled way one from the other and a crimp in each pouch ply spaced from said mouth edges.
DETAILED DESCRIPTION OF THE INVENTION
[0025] Turning now to the drawings, it will be appreciated that pouches described herein can be made from a variety of suitable pouch materials, including but not limited to synthetic materials, metal or metallized materials, aluminized materials and any other suitable materials as desired. It will also be appreciated that similar components of the embodiments in the drawings are designated with identical numbers.
[0026] FIGS. 1 and 2 illustrate one embodiment of the invention in which a bandolier 10 of serially connected pouches 12 , 14 , 16 , for example, are transported through a nip 20 defined by two rollers 22 , 24 . The bandolier comprises at least two adjacent pouch plies 26 , 28 (see FIGS. 1A , 1 B, 1 C) folded about a fold line 30 along which is the pouch bottom. Each pouch has a mouth region 32 defined by the adjacent plies 26 , 28 . Each mouth region 32 terminates in an edge 34 , 36 as indicated in the FIGS.
[0027] Each pouch is defined by a sealed side seam 38 , 39 formed transversely across plies 26 , 28 . Eventually, and either before or after pouch opening or filling, the pouches 12 , 14 and 16 are separated about respective cut lines 40 , 41 , for example, to form individual pouches such as those shown in FIGS. 3 and 6 .
[0028] Preferably while in bandolier form 10 , the pouches are transported through nip 20 in the machine direction MD, with plies 26 , 28 at the mouth region 32 squeezed by an appropriate pressure presented by the nip such as between rollers 22 , 24 .
[0029] Rollers 22 , 24 are rotatably mounted via a frame member 44 and any suitable roller drive or support structure 46 as may be desired. One, both or neither of the rollers 22 , 24 can be driven. Each counter-rotate with respect to the other as plies 26 , 28 are transported therebetween, and as illustrated by the direction arrows R- 1 , R- 2 of FIG. 2 . Rollers 22 , 24 are preferably biased with respect to each other to form nip 20 . One or both rollers 22 , 24 can be biased toward the other.
[0030] FIGS. 1 , 1 A and 2 illustrate one preferred embodiment of the invention for conditioning a pouch 50 as shown in FIG. 3 . In FIGS. 1 and 2 , two opposed rollers 22 , 24 each have a peripheral surface 46 defining a crimp pattern 47 of a plurality of parallel ridges 48 and valleys 49 as illustrated.
[0031] When plies 26 , 28 are transported through nip 20 , a corresponding crimp pattern is applied in the respective plies. It will be appreciated that the ridges 48 and valleys 49 of the rollers 22 , 24 may be offset one from the other or may be directly opposed, all to form a crimp pattern in mouth region 32 and preferably up to the mouth edges 34 , 36 .
[0032] A resulting pouch 50 ( FIG. 3 ) whether individually cut, then opened, or a plurality of pouches 50 still in bandolier form for opening and filling (not shown) is thus formed.
[0033] The resulting crimped mouth region 32 in this pouch 50 is of such a stiffness that it robustly opens and remains open when an airstream 52 is directed onto the mouth. Edges 34 , 36 do not tend to reclose after opening due at least in part to this increased stiffness.
[0034] An alternative pouch 54 ( FIG. 6 ) is likewise formed by drawing plies 26 , 28 through a nip 20 , but in a slightly elevated path with respect to rollers 22 , 24 . In this embodiment, the crimp pattern of the rollers is disposed beneath, or spaced slightly from the mouth edges 34 , 36 . The crimp in the plies is still in mouth region 32 , but is so below the edges 34 , 36 that the result is a curling of the respective edges 34 , 36 outwardly and away from each other as in FIG. 6 . This forms an even wider mouth 56 facilitating opening of the individual or bandolier formed pouch mouths.
[0035] Further embodiments of the invention are illustrated in FIGS. 1B , 1 C, 4 and 5 .
[0036] FIG. 1B and FIG. 4 illustrate one embodiment where a nip 20 is formed by rollers 60 , 62 . One roller 60 has a smooth peripheral surface 61 while roller 62 is like that of crimp pattern roller 24 in FIG. 1A . This embodiment results in an application of a crimp pattern 48 , 49 of roller 62 to ply 28 , while ply 26 remains substantially smooth. Since the crimp is applied up to edges 34 , 36 , the pouch mouth remains relatively straight ( FIG. 4 ).
[0037] This configuration produces a pouch like that of FIG. 3 , with the exception of one ply remaining smooth. Nevertheless, the crimping of one ply so stiffens the mouth of such a pouch that opening and remaining open is enhanced. And further, if the plies are elevated through nip 20 of FIG. 4 , the top edges 34 , 36 will tend to curl away one from the other as illustrated in FIG. 1 , but with one ply remaining smooth.
[0038] FIG. 1C illustrates yet another embodiment of the invention wherein nip 20 is defined by two smooth rollers 70 , 72 , each having a smooth surface 73 . Preferably, the plies 26 , 28 passing nip 20 of FIG. 1C are elevated so the plies are squeezed between respective smooth surfaces 73 in mouth regions 32 , but in a part of region 32 spaced from edges 34 , 36 as shown in FIG. 5 . Edges 34 , 36 are thus curled, as shown in FIG. 5 , one away from the other to form an open area 74 between plies 26 , 28 facilitating further opening of the pouch mouth by an air stream as desired. This curl, accompanied by the conditioning of the plies 26 , 28 in the nip, facilitates and enhances opening of such a pouch. This embodiment then, in use, is partly illustrated in FIG. 6 with the exception that the plies 26 , 28 in mouth region 32 are smooth, rather than crimped in a pattern as in FIG. 6 .
[0039] It will be appreciated that while nip 20 is shown in the embodiments herein formed by two opposed rotatable rollers, the invention contemplates a single roller forming a nip with opposed back-up surfaces of a variety of expedients.
[0040] Accordingly, the invention contemplates a pouch having a pressed or squeezed mouth region in either a pattern format or smooth to strengthen the mouth and to facilitate opening reliably and consistently. Pouch plies can be squeezed to cause an edge curl widening the mouth for opening. Preferred apparatus includes a roller defined nip for imparting a crimp to a pouch mouth region and to squeeze the pouch mouth region to form a curl in the mouth edges whether or not a crimped pattern is formed in the pouch. Rollers can have crimped or smooth peripheries. A preferred method according to the invention includes running pouch plies through a nip in the pouch mouth region either to impart a crimp thereto to facilitate mouth opening and hold open or to cause mouth edges to curl and facilitate mouth opening, or both.
[0041] These and other alternatives and modifications will be readily apparent to one of ordinary skilled in the art without departing from the scope of the invention and applicant intends to be bound only by the claims which are made in this application.
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An improved pouch has a crimped or squeezed mouth region to facilitate pouch opening and hold open during filling. Mouth edge curls are disclosed for enhancing mouth opening. Roller nip and crimp roller apparatus is disclosed. Pouch conditioning methods are disclosed.
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BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates generally to underground fluid pumping systems and more particularly, to such pumps which are capable of activating in response to surrounding liquid levels.
2. Discussion
Increased monitoring of environmental quality has resulted in a substantial rise in the number of identified sites of contaminated ground water. Accompanying this trend has been an increased effort to clean up these sites. In response, there is a need for improved below ground pumping systems to assist in these clean up efforts.
Ideally, pumping systems used for these purposes will have a number of characteristics. Because of the large number of pumps required is it desired to minimize the cost of each pump and installation. Accordingly, such pumps should be relatively simple and inexpensive and should fit in a small diameter well due to the increased cost of drilling larger diameter wells. To minimize maintenance and repair costs, the pumps should have a minimum of moving parts and should have high reliability. Also, such pumps should be able to withstand corrosive fluid streams without failure.
Due to the possibility of exposure to explosive gases pneumatic pumps are preferred over electrical pumps for pumping waste products. However, many of the currently used pneumatic pumps have a number of drawbacks. For example, many pumps in current use require external controlling devices which use timers to activate the pump on a fixed schedule. However, the necessity of external controllers adds considerably to the cost and complexity of the overall pumping system. In addition, the use of a fixed time pumping schedule has disadvantages since it may not result in pumping at the most opportune time to obtain maximum production. For example, such a configuration would not sense variations in the flow rate of fluid into the pump and may result in too fast or too slow pump cycles.
There are pumps which avoid the necessity of external controllers by incorporating sensing means within the pump to detect when fluid has entered the pump to a desired level. Unfortunately, the prior pumps which are capable of self activation have not proved satisfactory in many applications. One problem has been with the mechanical actuating and sensing mechanism within the pumps. Generally, such pumps use a float which raises when the pump fills and lowers when the pump is empty. Actuating mechanisms which sense the movement of this float sometimes require considerable force to switch the pumps pneumatic valve on and off. This results in the necessity of a fairly large and heavy float which increases the overall size and cost of the pump system. In addition, the actuating mechanisms in prior pump systems are exposed to the pumped fluid which may be highly corrosive. Thus, pump systems which are suitable for use in pumping inert materials may fail prematurely when the actuating mechanism is exposed to a highly corrosive fluid such as maybe found in contaminated well sites such as landfills.
In addition to problems with the actuating mechanism, the pneumatic valve used to control the flow of compressed air into these pumps have often proved unreliable. Spool type valves incorporating sliding seals are generally used in prior pumps of this nature. The force necessary to move these sliding seals to actuate spool type valves are one source of excess actuation force requiring the above mentioned large and heavy floats. In addition, spool type valves result in high maintenance and repair costs due to their tendency to freeze or to leak. There are a number of causes of the difficulties with sliding seals. These include debris entering the seals from the source of compressed air; contamination of the seals from the liquid being pumped; (especially where highly corrosive waste products are pumped) loss of lubrication in the seals; and compression set of the elastomeric seals if they remain inactive for an extended period of time. In addition, some pumps employ valves which have a significant cross over point where air supply is partially open and exhaust is partially closed. At this point the pump will tend to use a large amount of compressed air in an effort to switch to fully open or fully closed. In some cases the pump may reach a steady state with the head pressure in the surrounding well and remain in a cross over, or all ports open, position.
Another difficulty with sliding seals results from their use to provide a detent action between the discharge and refill cycles of the valve. As the sliding seals (which generally comprise of o-rings) wear, the ability of the o-rings to provide a detent action will be lost. This will result in short and erratic pump cycles unless the o-rings are replaced. Thus, it would be desirable to provide an underground pumping which overcomes some or all of the above-mentioned difficulties.
Accordingly, it is an object of the present invention to provide a simple and inexpensive pumping system for installing in small diameter wells. It is a further object of the present invention to provide such a pumping system which is reliable, has few moving parts, and which provides automatic on/off level control to eliminate the need for external controllers.
It is an additional object of the present invention to provide a underground pumping system which uses a pneumatic valve that avoids the use of sliding seals and which is switched from between pumping to discharge cycles with a minimum of actuation force. It is a further object for the present invention to provide such a system having a reliable and durable detent between pump discharge and refill cycles. It is still a further object of the present invention to provide an underground pump system in which the pneumatic valve is substantially isolated from the corrosive waste fluid stream.
SUMMARY OF THE INVENTION
There is provided according to present invention, a device for inexpensively and reliably pumping underground fluids.
Toward this end, a system is provided for directing liquid out of a well having an outer tube forming an outer chamber therein and inner tube forming an inner chamber therein. An inlet means is located at a first end of said tubes for permitting liquids to enter the outer and inner chambers. A cap is disposed at a second of the tubes, the cap containing a discharge port in communication with the second end of the inner tube. An air inlet port is located in said cap for permitting pressurized air to enter the second end of the outer tube. A vent port is provided for permitting air in the outer chamber to escape to atmosphere when fluid is entering the chambers. A float is slidably disposed inside the outer tube which is buoyant in the liquid so that it may slide from the first end to the second end of the outer tube in response to the level of the liquid in the outer chamber. A valve is disposed in the inlet port for selectively admitting in a discharge mode, and blocking in a refill mode the source of compressed air into the outer chamber and for also selectively venting in the refill mode, and blocking in the discharge mode, the outer chamber to the vent port. An actuating rod means responsive to the position of the float and coupled to the valve is provide for actuating the valve from the first mode to the second mode so that liquid is admitted into the inner and outer chambers during the refill mode and forced from the outer chamber through the inner chamber at the discharge port during the discharge mode.
In accordance with one embodiment of the present invention the actuating means includes an actuating rod in said outer chamber movable by said float, first and second opposing magnets, the first magnet being near one end of the actuating rod and the second magnet being located within the cap means but isolated from the outer chamber and movable by the first magnet in response to the motion of the float. The second magnet communicates with the valve to cause the valve to switch from one mode to the other.
In accordance with another aspect of the present invention, the valve is a pneumatic bleed-type air piloted three way control valve actuated by the actuating means.
BRIEF DESCRIPTION OF THE DRAWINGS
Additional objects, advantages an features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings.
FIG. 1 is a longitudinal cross-sectional view of the pump apparatus in accordance with the present invention shown in the refill cycle;
FIG. 2 is a longitudinal cross-sectional view of the pump shown in FIG. 1 in a discharge cycle;
FIG. 3 is an enlarged cross-sectional view of a portion of the pump apparatus shown in FIG. 1 in the refill cycle;
FIG. 4 is a enlarged cross-sectional view of a portion of the pump shown in FIG. 2 in the discharge cycle;
FIG. 5 is a top view of the pump apparatus shown in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, there is shown, a pump apparatus 10 in accordance with a preferred embodiment of the present invention. The pump includes a hollow outer tube 12 which forms the main body of the pump 10. The outer tube 12 is preferably composed of a rigid material not susceptible to corrosion, such as stainless steel. The outer tube 12 is closed at its lower end by a liquid inlet port 14 which is inserted into the lower end of the outer tube 12 in a reduced diameter portion 16 of the outer tube 12 to form a liquid tight seal between the liquid inlet port unit 14 an the outer tube 12. The liquid inlet port 14 includes an inlet port 18, a valve seat 20, and a check ball 22. A check ball stop 24 serves to confine the check ball to within the inlet port 14.
At the opposite end of the outer tube 12, is a pump cap 26 which, like the inlet port 14, is secured to the end of the outer tube 12 by inserting it into a reduced diameter portion 28 of the outer tube 12 to form a liquid and air tight seal with the outer tube 12. (The pump cap 26 may be preferably composed of a nonmagnetic material such as a plastic, for example, nylon, PVC or Teflon. The pump cap 26 includes a liquid discharge port 30 which passes through the pump cap 26 to the pump chamber 32 in the interior of the outer tube 12. The liquid discharge port 30 contains a discharge check valve 34 which includes a discharge check ball 36, a discharge check valve seat 38 and a check ball stop 40. The pump cap 26 includes an air inlet port 42 into which is inserted a pneumatic valve 44 which will be discussed in greater detail below. Below the pneumatic valve 44 in the air inlet port 42 is a pilot magnet 46 and an air pilot bias spring 48, which biases the pilot magnet 46 in a position away from the pneumatic valve 44 and against the bottom portion 50. An actuating magnet 78 is located in the pump cap 26.
At the inward portion of the liquid discharge port 30, is an opening 54 into which is inserted an inner discharge tube 56. The inner discharge tube 56 is preferably constructed of a rigid material not susceptible to corrosion, such as stainless steel, Nylon, or PVC. The inner discharge tube 56 extends into the pump chamber 32 to a point close to the liquid inlet port 14. A lower pump guide 58 is secured to the interior of the pump chamber 32 and includes an opening 60 into which the inner discharge tube 56 is inserted. A float 62 is disposed inside the pump chamber 32 having an axial bore 64 into which the inner discharge tube 56 is inserted. There is sufficient clearance between the axial bore 64 and the inner discharge tube 56 to permit the float 62 to freely slide up and down along the inner discharge tube 56. The float is preferably made of a material which is less dense than the liquid to be pumped to provide sufficient lifting action when the pump is filled as will be explained in more detail below. In addition, it is necessary for the float to have sufficient dry weight when the pump is empty to de-actuate the pneumatic valve 44 as described below. A suitable material for float 62 may be, for example, syntactic epoxy, stainless steel or other resins.
An actuation rod 66 is disposed adjacent to the inner discharge tube 56 in the pump chamber 32. The lower end of the actuation rod 66 is inserted into an axial bore 68 in the lower pump guide 58. A lower float-actuator rod stop 70 is affixed to the actuation rod 66 above the lower pump guide 58. The actuation rod 66 is also inserted into a second float axial bore 72. Both the lower pump guide axial bore 68 and the second float axial bore 72 are large enough to provide sufficient clearance around the actuation rod 66 to permit the actuation rod to freely move up and down with respect to the float 62 and the lower pump guide 58. The actuation rod 66 is preferably made of a light weight and rigid material such as nylon. At the upper end of the actuation rod 66 is an actuation head 74 which has a larger diameter than the actuation rod 66, the lower surface of which forms a first float stop 76. The actuation rod head 74 also includes at the extreme upper end an actuator magnet 78. The actuator magnet 78 is carried in the actuator head 74 with the north pole of the magnet at the extreme upper end, and the south pole immediately below. The actuator head 74 is inserted into the actuating magnet bore 52. The actuator head 74 also carries a snap action latch magnet 80 at its lower portion with the north pole of the magnet on the upper end of the south pole at its lower end. Adjacent to the snap action latch magnet 80 is a guide and a snap action magnet assembly 82 which is rigidly attached to the outer tube 12 and includes an axial bore 84 into which the inner discharge tube 56 is inserted and which also includes a second bore 86 into which the actuator head 74 is inserted. The second bore 86 includes adequate clearance for free movement of the actuator head 74 therein. The guide and snap action magnet assembly 82 also includes a stationary latch magnet (not shown) which will be described in further detail below.
Referring now to FIG. 3 there is shown an enlarged view of the pump cap 26 containing the pneumatic valve 44. The pneumatic valve 44 is preferably a bleed-type air piloted three way control valve. This valve includes a pair of diaphragms, the top one being a perforated diaphragm 88, and the bottom one being a solid diaphragm 90. The perforated diaphragm 88 includes a series of perforations 92. The diaphragms are connected by a valve stem 94 which includes a bleed orifice 96 formed by a axial bore passing completely through the valve stem 94. A wire 98 passes through bleed orifice 96 and contains right angles at either end. A bias spring 100 is located above the perforated diaphragm 88 and acts to bias the perforated diaphragm and solid diaphragm 90 in a downward or valve closed position. The diaphragms 88, 90 include a pair of poppet valve seats. The perforated diaphragm 88 having an upper poppet valve seat 102 and the solid diaphragm 90 having a lower poppet valve seat 104. The upper and lower poppet valve seats 102, 104 form a seal with upper and lower seat surfaces 106, 108 to effect an airtight seal. In FIG. 3, the valve is shown in the normally closed position wherein the upper poppet valve seat 102 is closed and the lower poppet valve seat 104 is open. Conversely, FIG. 4 shows the valve in an open position wherein the upper poppet seat 102 is open and the lower poppet valve seat is closed. The pneumatic valve 44 also includes a cylinder port to pump 110 which provides a means for air to pass from the source of compressed air through the valve 44, through the cylinder port to pump 110 and into the pump chamber 32 when the valve 44 is in the open position as shown in FIG. 4. The pneumatic valve 44 also includes a pump exhaust port 112 which provides a means for venting of the pump chamber 32 by connecting the pump chamber 32 with the main exhaust port 114 shown in FIG. 5 when the pump is in the closed position as shown in FIG. 3. The pneumatic valve 44 also includes a pilot orifice 116 in communication with the bleed chamber 118. A pilot bleed exhaust port 122 is provided adjacent the pilot orifice 116 in the pump cap 26. Referring now to FIG. 5 the pilot bleed exhaust port is shown in a top view of the pump cap 26. In addition, the liquid discharge port 30, the compressed air supply port 42 and the main exhaust 114 are shown in FIG. 5.
The operation of the pump apparatus 10 will now be described. Initially, the pump apparatus 10 is installed in a well with separate lines for liquid discharge attached to the liquid discharge port 30, compressed air supply attached to the compressed air supply port 42, a main exhaust line attached to the main exhaust port 114 and a pilot bleed exhaust line attached to the pilot bleed exhaust port 122. The source of compressed air is then turned on. Compressed air passes into the compressed air port 42 through the bleed orifice 96 located in the valve stem 94. This air passes through the bleed chamber 118 and pilot orifice 116 to the bleed pilot exhaust port 122. At this point the pump is in the refill mode as shown in FIG. 1 with the valve in its normally closed position as shown in FIG. 3. It should be noted that the volume of compressed air passing out into the bleed orifice exhaust 122 is relatively small due to the small opening in the bleed chamber 118. Thus in this mode, the pump is essentially off and little compressed air is wasted.
If there is no liquid in the well the pump remains in this state indefinitely. When liquid is introduced into the well it will enter the inlet port 18 and flow past the inlet check valve 14. As the liquid level rises into the pump chamber 32, the float 62 rises also with it and slides upward in the pump chamber. The float 62 continues to rise until it encounters the first float stop 76 on the actuator rod actuation head 74. As the liquid level continues to rise, the float lifts the actuator rod 66. At a preset point the snap action latch magnet 80 on the actuator head 74 passes through the field created by the two opposing stationary latch magnets 124 which are located in the guide and snap action magnet assembly 82. When the snap action latch magnet 80 passes through this field it is pushed upward in a snapping action by the opposing magnet field created by the stationary latch magnets 124. This upward motion continues until the actuation head 74 encounters a stop built into pump cap 26. As seen in FIG. 2, the float 62 will continue to rise until it reaches the lower edge of the guide end snap action magnet assembly 82 which will resist further upward motion by the float 62. It should be noted that the action of the stationary latch magnet 124 has pushed the actuation head 74 upward so that the float stop 76 no longer is in contact with the float 62.
At this point, the actuator magnet 78 on the upper portion of the actuator head 74 creates a magnetic field opposing the pilot magnet 46. This moves the pilot magnet 46 against the air pilot bias spring 48 to make contact with and close the pilot orifice 116.
After the pilot orifice 116 is closed by the pilot magnet 46, the pilot bleed air supply from the pilot bleed orifice 118 builds air pressure to the minimum pilot pressure required to pilot the air valve 44. At this point the pilot pressure moves the solid diaphragm 90 upward which causes the valve stem 94 to move upward along with the perforated diaphragm thereby opening the upper poppet valve seat 102 and closing the lower poppet valve seat 104. At this point the pump apparatus 10 is in the discharge mode as shown in FIGS. 2 and 4. The valve is now in the open position and the lower poppet valve seat will close off the pump exhaust port 112. The upper poppet valve seat 102 is now open which permits compressed air to pass into the cylinder port to pump 110 thereby permitting compressed air to reach the pump chamber 32.
This flow of compressed air will continue into the pump chamber 32 until sufficient pressure is obtained to overcome the hydrostatic head located on the discharge check ball 36. Also, this pressure will cause the inlet check valve 14 to seal. At this point, the liquid in the pump chamber 32 will flow up the inner discharge tube 56 past the discharge check valve 34 and out the liquid discharge port 30.
As liquid is flowing out of the pump, the liquid level in the pump becomes lower. The float 62 follows the liquid level until it encounters the lower float actuator rod stop 70. As the liquid level continues to lower, the dry weight of the float increases its load on the lower actuator rod stop 70. At a preset point the weight of the float 62 overcomes the magnetic latch due to the action of the stationary latch magnets 124 on the snap action latch magnet 80 and the actuator rod assembly moves a preset distance toward the bottom of the pump 10.
After the actuator rod 66 has been disengaged from the magnetic latch 124 holding it in the up position, the pilot magnet 46 moves away from the pilot orifice 116. The compressed air trapped between the pilot orifice 116 and the solid valve diaphragm 90 is free to escape to atmosphere and the pilot pressure returns to atmospheric pressure.
After the pilot air pressure has dropped below the minimum valve pilot pressure, the biasing spring 100 and the air pressure differential move the perforated diaphragm 88, the valve stem 94 and the solid diaphragm 90 to the closed position as shown in FIGS. 1 and 3. The upper poppet valve seat 102 seals and stops the flow of compressed air to the cylinder port to pump 110. At the same time the lower poppet valve seat 104 opens and allows compressed air in the pump chamber 32 to escape to the main exhaust 114 via the pump exhaust port 112.
When the air pressure in the pump body has reached a level that is less than the hydrostatic pressure on the inlet check ball 22, the inlet check ball 22 will open and liquid will fill the pump again providing there is liquid present. As liquid rises in the pump, the float 62 follows the liquid and repeats the cycle described above. If no additional liquid is present, the pump 10 has the advantage that it will remain in a state of rest until liquid rises to a preset level, thus providing "on/off" level control. The benefit of this is a reduced duty cycle on the air compressor, or conservation of compressed air sources. This "on/off" level control is also beneficial to automatically maintain specified minimum liquid levels in applications such as landfills.
In addition it will be appreciated that the isolation of the actuating components of valve 44 and in particular the bleed chamber 118, pilot orifice 116 and the pilot magnet 46 from the liquid being pumped means that these components are not subject to the corrosive or damaging influence of the liquid being pumped. This greatly improves the reliability and useful life of the pump apparatus 10 and pneumatic valve 44. Further, due to the use of magnetic detent and magnetic actuators, the force required to activate the pneumatic valve 44 is minimized thus permitting a smaller and lighter float to be used then would otherwise be required. This reduces the overall size of the well required as well as reducing the size and cost of the pump apparatus 10.
The bleed type air piloted three way control valve 44 used in the present invention is adapted from a standard valve manufactured by Humphrey Products Company. Modifications to this standard valve have been made however. For example, a hole has been drilled through the valve stem 94 to permit the source of compressed air to reach the bleed orifice 116. Without this hole, a separate source of bleed air is necessary to be introduced into the solid diaphragm 90. In addition, the wire 98 in the valve stem 94 permits a larger size bleed orifice 116, then would otherwise be required making this orifice easier to manufacture. This is because the wire reduces the air consumption. For example, the bleed orifice 116 may be about 0.0145 inches with the use of a 0.011 inch diameter wire. The wire has an added benefit of keeping the bleed orifice 116 open and free of debris as the valve shifts back and forth.
It should also be noted that the bleed type air piloted three way control valve 44 in conjunction with the pilot magnet 46 minimizes the above discussed crossover point problem. While this valve 44 does have a crossover point as the valve shifts, the magnetic latching mechanism with the spring bias to the off position makes any crossover insignificant.
It should be recognized that the present invention can be used in a wide variety of underground pumping applications. In particular, the pump can be used in many applications where previously only pumps employing external controllers were practical. While the above description constitutes the preferred embodiments of the present invention it will be appreciated that the invention is susceptible to modification, variation, and change without departing from the proper scope and fair meaning of the accompanying claims.
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A pump apparatus for pumping undergound fluids from a well. The pump includes inner and outer chambers, and a float slidable within the outer chamber. A source of compressed air is directed to a valve on the pump. The valve controls the flow of the compressed air into the outer chamber during the pumping cycle, and also controls the opening of a vent during the intake cycle. The float, while sliding up and down within the outer chamber in response to the fluid level within the chamber, activates the valve to begin the pumping of fluid when the chamber is full. When the chamber is empty, the float activates the valve is turn off the compressed air.
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FIELD OF THE INVENTION
The invention relates to a sensor.
Furthermore, the invention relates to a sensor array.
Moreover, the invention relates to a method of operating a sensor.
BACKGROUND OF THE INVENTION
A biosensor may be denoted as a device which may be used for the detection of an analyte that combines a biological component with a physiochemical or physical detector component.
For instance, a biosensor may be based on the phenomenon that capture molecules immobilized on a surface of a biosensor may selectively hybridize with target molecules in a fluidic sample, for instance when an antibody-binding fragment of an antibody or the sequence of a DNA single strand as a capture molecule fits to a corresponding sequence or structure of a target molecule. When such hybridization or sensor events occur at the sensor surface, this may change the electrical properties of the surface which can be detected as the sensor event.
US 2004/0110277 discloses a bio-sensor comprising a sensor cell matrix in which sensor cells are arranged into a matrix, a row driver which supplies a specific voltage signal to a group of sensor cells lined up in the row direction of the matrix, and a column driver which supplies a specific voltage signal to a group of sensor cells lined up in the column direction of the matrix. Each sensor cell comprises a capacitance element consisting of a pair of opposing electrodes with probe DNA molecules that react selectively with target DNA molecules immobilized to their surfaces, a transistor whose gate terminal is connected to the capacitance element so that the current value that is output from the drain terminal of this transistor is caused to vary in accordance with the amount of the capacitance variation of the capacitance element which is varied by the hybridization of the DNA, and a switching element which supplies a voltage signal supplied from the column driver to the current input terminal of the transistor.
Conventional sensor chips may suffer from a signal to noise ratio which may be too small.
OBJECT AND SUMMARY OF THE INVENTION
It is an object of the invention to provide a sensor having a sufficiently large signal to noise ratio.
In order to achieve the object defined above, a sensor, a sensor array, and a method of operating a sensor according to the independent claims are provided.
According to an exemplary embodiment of the invention, a sensor for detecting particles is provided, the sensor comprising an electrode (which may form one plate of a capacitor), a sensor active region (for instance comprising capture molecules) covering the electrode (for instance being arranged in such a manner that sensor events occurring at the sensor active surface have an impact on the electric condition of the electrode) and being sensitive for the particles, a first switch element operable to bring the electrode to a first electric potential (at a first time) when the first switch element is closed (that is when an electrically conductive coupling between the electrode and a node providing the first electric potential is enabled by the first switch), a second switch element operable to bring the electrode to a second electric potential (at a second time which may differ from the first time) when the second switch element is closed (that is when an electrically conductive coupling between the electrode and a further node providing the second electric potential is enabled by the second switch), and a detector adapted to detect the particles based on a change of the electric properties of the sensor in an operation mode in which the electrode is brought to the first electric potential and an operation mode in which the electrode is brought to the second electric potential (for instance, the amount of the change may be dependent on the presence/absence or the concentration of the particles, since an accumulation of (for instance dielectric) particles in an environment of the sensor active region may change the electric properties, particularly the capacity, of the electrode).
According to another exemplary embodiment of the invention, a sensor array is provided comprising an arrangement of a plurality of sensors having the above-mentioned features. However, multiple sensors may share the same electric potential or sources of electric potential.
According to still another exemplary embodiment of the invention, a method of detecting particles using a sensor is provided, the method comprising bringing a sensor active region covering an electrode in contact with the particles, bringing the electrode to a first electric potential, subsequently bringing the electrode to a second electric potential, and detecting the particles based on a change of the electric properties of the sensor in an operation mode in which the electrode is brought to the first electric potential and an operation mode in which the electrode is brought to the second electric potential.
The term “sensor” may particularly denote any device which may be used for the detection of the presence/absence or even the concentration of particles.
The term “biosensor” may particularly denote any device which may be used for the detection of an analyte comprising biological molecules such as DNA, RNA, proteins, enzymes, cells bacteria, virus, etc. A biosensor may combine a biological component (for instance capture molecules at a sensor active surface capable of detecting molecules) with a physiochemical or physical detector component (for instance a capacitor having a capacitance which is modifiable by a sensor event).
The term “(bio)sensor chip” may particularly denote that a (bio)sensor is formed as an integrated circuit, that is to say as an electronic chip, particularly in semiconductor technology, more particularly in silicon semiconductor technology, still more particularly in CMOS technology. A monolithically integrated biosensor chip has the property of very small dimensions thanks to the use of micro-processing technology, and may therefore have a large spatial resolution and a high signal-to-noise ratio particularly when the dimensions of the biosensor chip or more precisely of components thereof approach or reach the order of magnitude of the dimensions of biomolecules.
The term “biological particles” may particularly denote any particles which play a significant role in biology or in biological or biochemical procedures, such as DNA, RNA, proteins, enzymes, cells, bacteria, virus, etc.
The term “sensor active region” may particularly denote an exposed region of a sensor which may be brought in interaction with a fluidic sample so that a detection event may occur in the sensor active region. In other words, the sensor active region may be the actual sensitive area of a sensor device, in which area processes take place which form the basis of the sensing.
The term “substrate” may denote any suitable material, such as a semiconductor, glass, plastic, etc. According to an exemplary embodiment, the term “substrate” may be used to define generally the elements for layers that underlie and/or overlie a layer or potions of interest. Also, the substrate may be any other base on which a layer is formed, for example a semiconductor wafer such as s silicon wafer or silicon chip. Also a layer sequence may fall under the term substrate as used herein. Such a layer sequence may be formed on and/or in a substrate, that is may be a part thereof.
The term “fluidic sample” or “analyte” may particularly denote any subset of the phases of matter. Such fluids may include liquids, gases, plasma and, to some extent, solids, as well as mixtures thereof. Examples for fluidic samples are DNA-containing fluids, blood, interstitial fluid in subcutaneous tissue, muscle or brain tissue, urine or other body fluids. For instance, the fluidic sample may be a biological substance. Such a substance may comprise proteins, polypeptides, nucleic acids, DNA strands, etc. The analyte may particularly denote a substance that contains the bio-molecules to be analysed (for instance, blood plasma, saliva, urine, food, samples, etc., usually after pre-processing).
The term “capture probe” may particularly denote a molecule that can capture specific target molecules from an analyte.
The term “electrolyte” may particularly denote a substance containing free ions that behaves as an electrically conductive medium (for instance saline water).
The term “electrolytic capacitor” may particularly denote a capacitor comprising or consisting of a metal electrode, coated with an insulating layer (the dielectric), and a electrolyte electrode. The electrolyte can be connected by another metal with a conducting interface to the electrolyte.
The term “redox couple” may particularly denote molecules that can exchange one or more electrons with the electrode surfaces.
The term “SAM” may particularly denote a self-assembled monolayer of organic molecules. A SAM may denote a surface consisting of a single layer of molecules on a substrate. Self assembled monolayers can be prepared simply by adding a solution of the desired molecule onto the substrate surface and washing off the excess.
According to an exemplary embodiment of the invention, a sensor element is provided which has two switch elements adapted for selectively coupling or decoupling an electrode in functional contact with a sensor active portion provided between the two switch elements to one of two different electric potentials (which may be denoted as a transfer potential and a discharge potential). The sensor active region and the electrode may together form a capacitor like configuration (which may be completed by an electrolyte electrode) in which the value of the capacity is dependant on whether a sensor event takes place at the sensor active region or not. Consequently, when first coupling such a sensing capacitor with the first electric potential and afterwards with the second electric potential, a net charge flow during such a procedure may be optionally repeated one or several times may be a characteristic parameter indicative of a sensor element, and therefore indicative of the qualitative or quantitative determination of the particles This of another electric parameter may be detected by a detector (for instance by an amperemeter) and may allow to detect a sensor event with high accuracy, even in a scenario in which only a single biological molecule hybridizes with a corresponding complementary capture probe immobilized on the sensor active region.
Such an architecture may be particularly advantageous when nanoelectrodes are employed which are manufactured sufficiently small. For example, such nanoelectrodes can be made with dimensions of 250 nm, 130 nm or less, and may for instance be realized as sensing pockets having dimensions close to dimensions of biological molecules to the detected. This may allow to obtain a significant improvement of the signal-to-noise ratio. For instance, on a copper nanoelectrode, a self-assembled monolayer (SAM) may be provided which may be specifically designed to attach capture molecules such as antibodies. The copper electrode may then serve, in combination with a second electrode which can be another metallization layer of the semiconductor layer sequence or which can be a counter electrode which may be provided apart from the semiconductor layer sequence, as a capacitor. Sensor events (such as hybridization events between capture molecules immobilized on the SAM layer and target molecules in the sample) may then modify the value of the capacitance of the capacitor.
In the following, further exemplary embodiments of the sensor will be explained. However, these embodiments also apply to the sensor arrangement and to the method.
The electrode may be a sub-micron electrode. In other words, the electrode may have linear dimensions in the order of magnitude of a micrometer or less. Particularly, the electrode can be a nanoelectrode, particularly can have dimensions in a range of essentially one nanometer to essentially some hundred nanometers. By providing electrodes with such a small dimension and consequently with such a small area, the detection sensitivity may be significantly improved, since in such a configuration already few hybridization events or a single hybridization event at the sensor active region may result in a measurable electric signal at the electrode, in a configuration in which the switch elements are operated to electrically couple the electrode alternatingly with the first electric potential and the second electric potential.
The capacitance element may be a single electrode with an area comparable to that of the cross-section of a via (interconnect) plug in an advanced CMOS process. Small physical dimensions may be advantageous tor achieving single-molecule resolution. The smaller the electrode size, the higher the relative capacitance change as a result of a single-molecule capture. The footprint area of a captured bio-molecule on the electrode area may determine the corresponding capacitance change. All electrode area that is not covered by the captured molecule may in fact act as a parasitic capacitance in parallel to the capacitance change due to the single-molecule capture. That is why the electrode area should be a small as possible. A specifically appropriate electrode is as small as a molecule, provided the electrode pitch is small enough to ensure a reasonable surface coverage. The detectability of single molecules is a matter of achieving high-enough signal-to-noise ratio. In general, if all dimensions (except the molecule size) scale with the feature size of the CMOS process node (90 nm, 65 nm, 45 nm, etc.), the signal-to-noise ratio (which may be the square of the signal amplitude divided by the variance of the noise) is more or less proportional to the inverse of the sum of the electrode capacitance and its parasitic parallel capacitance. That is why the smallest possible electrodes are appropriate for single-molecule detection. But scaling the electrode size (for instance slightly or much) below the feature size of the CMOS process node does not help anymore because then the sensitivity saturates at a value determined by parasitic, while the surface coverage keeps decreasing.
When the sensor active region comprises a nanoelectrode, the dimensions of the electrode may be in the order of magnitude of nanometers, for instance may be less than 300 nm, for instance may be less than or equal to 250 nm, or may be less than or equal to 130 nm. The smaller the nanoelectrodes, the more sensitive the resulting sensor pocket or planar sensor surface.
The nanoelectrode may comprise copper material, particularly copper material being covered by a self assembled monolayer (SAM). These materials may serve as oxidation protection layers or as barrier layers or for enabling bonding of capture molecules, thereby allowing to implement the relative sensitive material copper which is highly appropriate due to its high electrical conductivity and compliance with procedural requirements. Copper material has chemically similar properties to gold which is conventionally used in biosensing, but which has significant disadvantages because it diffuses rapidly into many materials used in silicon process technology, thereby deteriorating the IC's performance, it is difficult to etch, and gold residues are hard to remove in cleaning procedures. However, less preferred embodiments of the invention may involve gold as well. Furthermore, materials such as aluminium or the like may be used as well, and even gold may be a less preferred example for such a material.
The first switch element and/or the second switch element may be a transistor. Such a transistor may have a gate region and may have two source/drain regions. The gate region of such switch transistors may be coupled to clock signals operating the transistor ins “high” or in a “low” operation mode, thereby selectively rendering the channel region between the two source/drain regions of a respective transistor conductive or not. One of the source/drain regions of a respective one of the two switch transistors is coupled to the respective first or second electric potential, wherein the other two source/drain regions of the two switch transistors are coupled to one another and to the electrode, which may also be denoted as a capacitor plate of the capacitor like sensor region. The transistors may be field effect transistors, bipolar transistors, etc. The transistors may be configured as an N-transistor or a P-transistor, for instance a P-MOS or an N-MOS.
The sensor active region may comprise one or more capture probes adapted for hybridizing with the particles. Such a capture prove may be, for instance, one of the two strands of a DNA helix and may have the property to specifically hybridize only with a particle to be detected having a complementary sequence. Thus, a highly specific sensor active region may be provided which may be based on hybridization events between the capture probes and specific particles.
According to an exemplary embodiment, a clock generator may be provided for providing the first switch element and the second switch element with clock signals to operate the first switch element and the second switch element to alternate between an operation mode in which the first switch element is closed (that is to say is coupled to the first electric potential) and the second switch element is simultaneously opened (that is to say is decoupled from the second electric potential), and an operation mode in which the first switch element is opened (that is to say is decoupled from the first electric potential) and the second switch element is simultaneously closed (that is to say is coupled to the second electric potential). Therefore, the clock signals generated by the clock unit (which may be controlled by or which may be a CPU, central processing unit) allow to operate the two switch elements complementary to one another to enable a non-overlapping sequence of “coupling” and “decoupling” phases. Thus, the clock signals provided with the two gates of the switch transistors may be inverse to one another. This may ensure that, with low effort, a reliable sequence of coupling/decoupling phases of the capacitor sensor with one of the two electric potentials is ensured, and that the pulsed or oscillating switching operation can be repeated several times. By repeating such switching modes, a time average of the detection signal may be obtained which may further allow to improve the accuracy, since artefacts may be filtered out or suppressed by such a repetition.
The detector may be adapted to detect the particles based on a net charge transfer between a node providing the first electric potential and a node providing the second electric potential during one or more cycles in which the electrode is brought to the first electric potential and in which the electrode is brought to the second electric potential As will be explained below (particularly referring to the description of FIG. 1 ) in more detail, it has been surprisingly found by the present inventors that the net charge transferred in connection with the described switching procedure is an accurate parameter allowing to qualitatively determine the particle concentration.
The sensor may comprise a further electrode configured to be kept at a fixed third electric potential (which may differ from the first electric potential and/or from the second electric potential). This fixed third electric potential may be an electrolyte potential of an electrolyte into which the further electrode is immersed. The constant third electric potential may be maintained by a counter electrode which may also be immersed in an electrolyte. Alternatively, the third electric potential may be maintained by correspondingly controlling electrodes of other sensors of a sensor array, as will be explained below in more detail.
The sensor may be manufactured CMOS technology. A CMOS generation appropriate for manufacturing a specific sensor may be dependent on the size of the electrode to be achieved. For example, for single molecule biosensors, the manufacture of very small electrodes may be favourable, resulting in the selection of an advanced CMOS technology generation. If in another embodiment the provision of larger electrodes is desired to immobilize a larger number of capture probes thereon, a former CMOS technology may be an appropriate choice.
The biosensor device may be monolithically integrated in a semiconductor substrate, particularly comprising one of the group consisting of a group IV semiconductor (such as silicon or germanium), and a group III-group V semiconductor (such as gallium arsenide).
The sensor may be adapted as a biosensor, particular as a single molecule biosensor which is able to detect even the presence of individual or single molecules. The biosensor may be based on a capacitive measurement principle, and may be an electrochemical biosensor.
Next, further exemplary embodiments of the sensor array will be explained. However, these embodiments also apply to the sensor and to the method.
The plurality of (for instance electrically interconnected) sensors constituting the sensor array may be arranged in rows and columns (that is to say in a matrix-like configuration). The rows and columns may be arranged to be aligned perpendicular to one another resulting in a rectangular or matrix-like pattern. Alternatively, it is possible to arrange the sensors in rows and columns forming a hexagonal pattern or the like.
In one embodiment, the first electric potential may be provided in common for at least two, particularly for all sensors of a column and the second electric potential may be provided in common for at least two, particularly for all sensors of a row, or vice versa. By taken this measure of applying a common electric potential (such as an electric voltage) to more than one sensor at the same time, a very efficient control of the entire system is made possible, since the electric potential control effort may be kept small.
The clock signals generated by a clock unit may be provided in common for at least two, particularly for all sensors of a row. This clock signal supply architecture may be advantageous since it allows to implement only a very small number of clock generating units in the sensor array by simultaneously supplying the clock signals to multiple sensors at a time. This may also allow for a proper synchronisation of the clock scheme for different sensors.
Sensors in adjacent rows may be arranged upside down to one another to share one of the group consisting of the first electric potential and the second electric potential. In other words, in a matrix like arrangement of the sensors, sensors of adjacent rows (that is rows which are directly next to one another) may be mapped to one another geometrically by using a horizontal mirror plane. Such a configuration may allow two sensors in adjacent rows and in the same column to share the same terminal for providing one of the first and the second electric potentials, resulting in a very dense and efficient configuration with a small number of control lines.
Sensors in adjacent columns may be arranged alternately left/right oriented to one another to share the first electric potential and/or the second electric potential. In other words, also sensors of adjacent columns may be arranged inverse to one another, wherein a mapping of such sensors can be geometrically obtained by a vertical mirror plane. Even this arrangement may contribute to make the electric signal supply scheme even more efficient.
According to an exemplary embodiment, the sensor array may be monolithically integrated in a substrate. Such a substrate may be a semiconductor substrate or any other substrate. It is also possible that such a substrate is formed by a sequence of layers provided on top of each other.
In such a configuration, the first switch element, the second switch element and the detector of the plurality of sensors may be buried within the substrate, that is may be provided beneath a surface of the substrate, for instance may be arranged in one of the lower lying layers of a layer sequence representing the substrate. In contrast to this, the electrode and the sensor active region of the plurality of sensors may be provided at or close to the surface of the sensor array. Thus, the electrodes may be exposed to a fluidic sample under analysis to enable a functional interaction between the sensor active regions and the particles to be detected. Furthermore, a spatial decoupling of the sensor electrodes and the electronic members located deeply within the substrate may further increase the accuracy, since undesired cross-talk between sensor events and electronic control signals may be suppressed by arranging the corresponding members sufficiently far away from one another without significantly reducing the density of the cell arrangement. For example, at least three layers, particularly at least five layers, more particularly at least eight layers may be located between the buried components and the surface bound components.
Particularly, the sensor array may further comprise a moisture resistant structure at the surface of the sensor array between adjacent ones of the electrodes of the plurality of sensors. By taken this measure, it may be securely prevented that a liquid sample under investigation penetrates into the sensor array which might disturb the electronic components embedded therein. By providing such a moisture resistant structure, for example fluorosilicate glass, the life time of the sensor array may be improved.
The sensor array may comprise a selection unit adapted for selecting one of the rows (at a time) for sensing, wherein the selection unit may be further adapted for disabling all other rows from sensing by opening the first switch element and the second switch element of the all other rows. Therefore, the non active rows may be simply biased to be non active, whereas a single row may be activated at a time.
Alternatively, a selection unit may be provided which is adapted for selecting one of the rows for sensing, but is further adapted for disabling all other rows from sensing and for closing the second switch element of at least a part of the all other rows to provide a counter electrode functionality. Only the discharge switch may be closed to include the corresponding electrodes in the reconfigurable counter electrode. This is not possible with the transfer switch because then the corresponding electrode would be connected in parallel with the active sensors element in the same row. In such a configuration, the electrodes which are presently not used for sensing may be not simply made inactive, but may be controlled to serve as a counter electrode to provide the sensor array with a constant electric potential at a position where it is coupled to an electrolyte. Therefore, the presently non-used electrodes may be synergetically used as configurable counter electrode members, which may make a separate counter electrode dispensable and may promote the miniature manufacturability of the sensor array.
The sensor array may further comprise a row periphery circuit comprising a number of multiplexers adapted for gating the rows. Particularly, such a row periphery circuit may comprise five multiplexers for each pairs of rows, the five multiplexers being configured to provide clock signals to operate the first switch element and the second switch element and to provide the first electric potential or the second electric potential to the sensors of a respective pair of rows.
It is noted that the previously described aspect of the invention can be implemented separately from the architecture described in the independent claims, however can be combined with any embodiment described herein. In other words, the previously described aspect is an independent aspect of the invention, which can be implemented without the other provisions disclosed herein. According to such an aspect, a sensor array me be provided comprising an arrangement of a plurality of sensors arranged in rows and columns, the sensor array further comprising a row periphery circuit comprising a number of multiplexers adapted for gating the rows. The row periphery circuit may comprise five (or another appropriate number of) multiplexers for each pair of rows, the five multiplexers being configured to provide clock signals to operate switch elements of the sensors and being configured to provide electric potentials to the sensors of a respective pair of rows.
By such a five multiplexer per row pair architecture, an efficient supply of all control signals and use signals may be ensured, and such a row periphery circuit may be employed with high versatility in different fields, for instance in the field of biosensors or also for controlling an array of memory cells.
The sensor array may comprise a column periphery circuit adapted for gating the columns. Thus, in addition to a row periphery circuit, a column periphery circuit may be implemented to adjust and control the electric potentials supplied to the various columns.
According to an exemplary embodiment, a calibration row may be provided having one or more calibration units each of which being constituted as each of the plurality of sensors but being free of as electrode and a sensor active region. In other words, such a calibration row may have sensors which are only void of the electrode and the sensor active regions. However, all the other components of a sensor may be present in such a calibration unit, so that the measurement of a signal at such a calibration unit may be a proper measure for an unspecific underground signal which is detected by the other sensors as well. Since only the interaction with the particles to be detected lacks for the calibration unit, the use of a calibration row may allow to improve the accuracy of the signals by allowing to calibrate the measured signals on the basis of the underground signal determined by the calibration unit. Alternatively two or more calibration rows may be operated simultaneously to create a larger calibration signal (this may be advantageous to compensate for the effect of the lacking electrodes in the calibration rows). Additionally or alternatively to a calibration row, it is also possible to provide a single calibration cell or a calibration column.
By using an entire row comprising a plurality of calibration units, an average over the individual calibration signals may be calculated to further improve the accuracy of the calibration parameters, since spatially dependent (for instance edge effects) effects can be suppressed by taking such a measure.
The detector of at least a part of the plurality of sensors may be adapted to perform a self referencing function by comparing a detection signal with an average detection signal of at least a part of the other sensors, particularly by comparing the detection signal with an average detection signal of other sensors of a row. For example, time drift effects may be suppressed by taking such a measure, since an individual signal is not considered in an isolated manner, but is compared with a time dependence of an average detection signal of other sensors which may allow to improve the signal to noise ratio and detect even the presence of a single bio-molecule.
The detector may be adapted to detect the particles in an operation mode in which the electrode is statically brought to the first electrical potential and is statically decoupled from the second electrical potential. In such an operation mode, no switching has to take place, so that the clock signals may be maintained at a constant level. In the presence of a time independent signal, it is possible to influence the properties of the capture molecules by such a signal.
The biosensor chip or microfluidic device may be or may be part of a sensor device, a sensor readout device, a lab-on-chip, an electrophoresis device, a sample transport device, a sample mix device, a sample washing device, a sample purification device, a sample amplification device, a sample extraction device or a hybridization analysis device. Particularly, the biosensor or microfluidic device may be implemented in any kind of life science apparatus.
For any method step, any conventional procedure as known from semiconductor technology may be implemented. Forming layers or components may include deposition techniques like CVD (chemical vapour deposition), PECVD (plasma enhanced chemical vapour deposition), ALD (atomic layer deposition), electroplating, or sputtering. Removing layers or components may include etching techniques like wet etching, plasma etching, CMP (chemical mechanical polishing), etc., as well as patterning techniques like optical lithography, UV lithography, electron beam lithography, etc.
Embodiments of the invention are not bound to specific materials, so that many different materials may be used. For conductive structures. it may be possible to use metallization structures, silicide structures, polysilicon structures, or conductive polymer structures. For semiconductor regions or components, crystalline silicon may be used. For insulating portions, silicon oxide or silicon nitride may be used.
The biosensor may be formed on a purely crystalline silicon wafer or on an SOI wafer (Silicon On Insulator).
Any process technologies like CMOS, BIPOLAR, BICMOS may be implemented.
The aspects defined above and further aspects of the invention are apparent from the examples of embodiment to be described hereinafter and are explained with reference to these examples of embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in more detail hereinafter with reference to examples of embodiment but to which the invention is not limited.
FIG. 1 illustrates a sensor according to an exemplary embodiment of the invention.
FIG. 2 illustrates a cross-sectional view of a metal-electrolyte capacitor formed by a metal bottom plate, a self-assembled monolayer (SAM) dielectric, and an electrolyte top plate, without (left) and with (right) a bio-molecule captured on the SAM.
FIG. 3 shows an achievable sensitivity for capacitance measurements with Agilent's Precision Impedance Analyser 4294A being 10 fF at 0.5 Vrms oscillator level (where the 10-fF line touches the 10% accuracy contour line).
FIG. 4 shows a capacitance input noise and resolution versus conversion time of the Analog Devices “24-bit Capacitance-to-Digital Converter with Temperature Sensor” ICs AD7745 and AD7746.
FIG. 5 shows an array of nano-electrodes and corresponding switch transistors with shared control and discharge lines (horizontal) and transfer lines (vertical) according to an exemplary embodiment of the invention.
FIG. 6 shows a schematic (left) and layout (right) of the same part of a sensor array according to an exemplary embodiment of the invention.
FIG. 7 to FIG. 11 each show a schematic (left) and layout (right) of the same part of a sensor array according to an exemplary embodiment of the invention.
FIG. 12 shows a cross-section along a column through the nano-electrodes of a sensor array according to an exemplary embodiment of the invention.
FIG. 13 shows a versatile row peripheral circuit with analog multiplexer switches according to an exemplary embodiment of the invention.
FIG. 14 shows a description of the signals of the row peripheral circuit of FIG. 13 according to an exemplary embodiment of the invention.
FIG. 15 shows a column peripheral circuit according to an exemplary embodiment of the invention.
FIG. 16 shows a system architecture according to an exemplary embodiment of the invention.
FIG. 17 shows an alternative system architecture according to an exemplary embodiment of the invention.
FIG. 18 shows a system architecture of sensor array with calibration rows according to an exemplary embodiment of the invention.
FIG. 19 shows an alternative system architecture of a sensor array with calibration rows according to an exemplary embodiment of the invention.
DESCRIPTION OF EMBODIMENTS
The illustration in the drawing is schematic. In different drawings, similar or identical elements are provided with the same reference signs.
In the following, referring to FIG. 1 , a biosensor 100 according to an exemplary embodiment of the invention will be explained.
The biosensor 100 is adapted for detecting biological particles (not shown in FIG. 1 ). The biosensor 100 comprises an electrode 102 as a first capacitor plate of a capacitor denoted with C in FIG. 1 . A second capacitor plate is formed by an electrolyte electrode 118 (for instance in a manner similar to FIG. 2 ). An electrolyte 119 is connected by a separate further electrode (not shown) to connect it to an electrical potential V L .
A sensor active region 104 covers the electrode 102 and is sensitive for the biological particles.
A first field effect switch transistor 106 is provided which is operable to bring the electrode 102 to a first electric potential V T when the first switch element 106 is closed. In other words, when a clock signal Φ T provided by a clock unit 110 is at a “high” level, the channel of the transistor 106 is electrically conductive, so that an electric coupling between the source/drain regions of the first switch transistor 106 is enabled, thereby directly coupling the electrode 102 to the electric potential V T . During the coupling of the electrode 102 to the first electric potential V T , a second clock signal Φ D supplied to a gate of a second switch field effect transistor 108 is at a “low” level, so that no electrically conductive coupling is provided between the electrode 102 and a second electric potential V D . In another operation mode, when the second switch element 108 is closed, the electrode 102 is coupled to the potential V D and is simultaneously decoupled from the potential V T by applying a “low” signal to the first field effect switch transistor 106 at this time. The complementary clock signals Φ T and Φ D are shown in diagrams 120 , 140 .
More particularly, the electrode 102 is coupled to a first source/drain region of the first switch transistor 106 and is coupled to a first source/drain region of the second switch transistor 108 . The first electric potential V T is applied to a second source/drain region of the first switch transistor 106 . The second electric potential V D is applied to a second source/drain region of the second switch transistor 108 . The clock signal Φ T is applied to a gate of the first switch transistor 106 . The clock signal Φ D is applied to a gate of the second switch transistor 108 .
Hybridization events between the biological particles and the sensor active region 104 may be detected by a detecting unit (not shown in FIG. 1 ) by determining or measuring a change of the electric properties of the sensor 100 in an operation mode in which the electrode 102 is brought to the first electric potential V T and an operation mode in which the electrode 102 is brought to the second electric potential V D . A modulation of such a charge transfer may be effected or may be the result of a change of the capacity C in the presence or absence of the particles.
FIG. 1 shows the sensor 100 in an operation mode at a first time t 1 at which the clock signal Φ T is “low” and the clock signal Φ D is “high”, so that a coupling between the electrode 102 and the second electric potential V D is activated, as indicated by an arrow 114 , while the electrode 102 is decoupled from the first potential V T . In contrast to this, at a time t 2 which is shown in FIG. 1 as well, the clock Φ T is “high” and the clock Φ D is “low”, so that the electrode 102 is coupled to the first electric potential V T , as indicated by an arrow 116 , and is decoupled from the second electric potential V D .
By performing the operation cycle shown in FIG. 1 once or several times, a net charge flow may be determined which can be taken as a basis for deriving information regarding the presence or absence and even for the concentration of the particles in an environment of the sensor active region 104 . Thus, qualitative or quantitative information about a sample under analysis may be obtained.
Capture probes are immobilized on the electrode 102 , forming a part of the sensor active region 104 which may additionally also comprise a self-assembled monolayer (shown and denoted with reference number 202 in FIG. 2 ).
The clock unit 110 is adapted for providing the first switch element 106 and the second switch element 108 with the clock signals Φ T and Φ D to operate the first switch element 106 and the second switch element 108 to alternate between an operation mode in which the first switch element 106 is closed and the second switch element 108 is simultaneously opened (t 2 ) and an operation mode in which the first switch element 106 is opened and the second switch element is simultaneously closed (t 1 ).
During this configuration, an electrolyte 119 may be kept at a fixed third electric potential V L provided by a counter electrode in electrically conductive contact with the electrolyte 119 into which the sensor active surface 104 is immersed.
The electrolytic capacitor C in FIG. 1 is drawn schematically with the following assumptions:
The first electrode 102 is the metal plate; The dielectric 104 is the sensor active region that is sensitive for biological particles. It is drawn here as an empty space between the first electrode 102 and a second electrode 118 ; The second electrode 118 is the interface between the sensor active region 104 and the electrolyte 119 . It comprises a self-assembled monolayer (SAM, if present) and the so-called “diffuse double layer” in the electrolyte. The diffuse double layer is the part of the electrolyte immediately above the first electrode and the SAM (if present) where the electric field penetrates. For an electrolyte with physiological salt concentration it has a thickness of the order of magnitude of 1 nanometer. So the actual capacitance of the capacitor C is determined by the series connection of the capacitance of the SAM (if present) and the capacitance of the diffuse double layer. The electrolyte 119 forms the electrically conducting path between the second electrode 118 and the location (not shown) where the electrical potential V L is connected.
Next, considerations regarding signal-to-noise ratio will be explained.
FIG. 1 shows an exemplary configuration of the biosensor 100 . First, the discharge switch transistor 108 is closed to discharge the “bio-electrolytic” capacitor C to the discharge voltage V D . After a subsequent opening of the discharge switch 108 the charge Q D on the capacitor C is
Q D =( V D −V L )( C+C P ) (1)
where V L is the voltage of the liquid, and C P is the parasitic capacitance in parallel to the capacitor C. Because of the thermal noise of the series resistance of the discharge switch 108 , the charge on the discharged capacitor C fluctuates from one discharged state to another. The variance of these fluctuations, which may be denoted as “reset noise”, is
σ Q P 2 =k B T ( C+C P ) (2)
where k B is Boltzmann's constant, and T is the absolute temperature.
Subsequently the transfer switch transistor 106 is closed to charge the capacitor C to the transfer voltage V T . After subsequent opening of the transfer switch 106 the charge of the capacitor C is
Q T =( V T −V L )( C+C P ) (3)
Because of the thermal noise of the series, resistance of the transfer switch 106 , the charge on the charged capacitor C also fluctuates from one charged state to another. The variance of these fluctuations is
σ Q T 2 =k B T ( C+C P ) (4)
The net charge Q transferred from the transfer terminal 106 (at voltage V T ) to the discharge terminal 108 (at voltage V D ) after N discharge/transfer cycles is
Q=N ( Q T −Q D )= N ( V T −V D )( C+C P ) (5)
Because the charge fluctuations of the discharged and charged states are uncorrelated (they originate from different uncorrelated noise sources) the variance of Q is
σ Q 2 =N (σ Q T 2 +σ Q D 2 )=2 Nk B T ( C+C P ) (6)
The change in Q as a result of a change δC in the capacitor C, caused by the capturing of one or more bio-molecules, is
δ Q=N ( V T −V D )δ C (7)
To be able to detect this capacitance change after N discharge/transfer cycles the signal-to-noise ratio
(
δ
Q
)
2
σ
Q
2
=
N
(
V
T
-
V
D
)
2
(
δ
C
)
2
2
k
B
T
(
C
+
C
P
)
(
8
)
should be high enough (the exact number depends on the required detection error probability). In practice additional noise sources of the circuit for measuring Q have to taken into account. There, (8) is an upper limit for the achievable signal-to-noise ratio.
The maximum tolerable modulation voltage |V T −V D | is limited by the dielectric reliability properties of C, that is, the leakage current, degradation, dielectric breakdown, etc. of the self-assembled monolayer (SAM). Therefore, for a given SAM and fixed N, the strategy for maximizing the signal-to-noise ratio depends on the use case.
Next, surface coverage fraction measurements will be explained.
For simplicity, the effect of capturing a bio-molecule on top of the SAM is described by the elimination of a small area A f (the footprint of the captured molecule on the SAM) from the total area A of the capacitor C (see FIG. 2 ). So the capacitance change associated to a surface coverage fraction
γ
=
KA
f
A
(
9
)
of the SAM by captured bio-molecules is
δ C=−γC (10)
where K is the number of captured bio-molecules. At fixed γ the maximum signal-to-noise ratio
(
δ
Q
)
2
σ
Q
2
=
N
(
V
T
-
V
D
)
2
γ
2
C
2
2
k
B
T
(
C
+
C
P
)
(
11
)
increases with increasing C. So for this use case C and, consequently, its area A, should be as large as possible.
For a properly designed circuit the parasitic capacitor C P is dominated by the parasitic capacitances of the two switching transistors 106 , 108 (mainly junction capacitances and overlap capacitances between the gate electrodes and the source/drain regions). For fixed series resistances of the discharge switch 108 and transfer switch 106 every consecutive CMOS process node (0.35 μm, 0.25 μm, 0.18 μm, etc.) typically has a smaller C P than its predecessor. But because C has to be large it is not necessary to implement the circuit in a more advanced CMOS generation that required for keeping C P small compared to C, and for fitting the switching transistors 106 , 108 in the are covered by C and its surrounding spaces to isolate it from neighbouring capacitors. Therefore, biosensors 100 for measuring surface covering fractions may be designed in “old” CMOS processes (which may be an attractive opportunity to give old CMOS tabs a second life).
Next single-molecule biosensors will be discussed,
Biosensors that measure surface coverage fractions can be used to measure average properties of ensembles of captured molecules. Furthermore, their large electrodes areas require SAMs with very low defect densities. Single-molecule biosensors may be required to overcome these limitations. They offer the potential to measure properties of individual bio-molecules. Furthermore, because of their small electrode areas, a significant fraction of functional electrodes can be obtained with SAMs with higher defect densities (bad electrodes can be detected and pruned).
The capacitance change associated to capturing a single bio-molecule is given by
δ C=−A f c 0 (12)
where the surface capacitance density
c
0
=
C
A
(
13
)
of C is a constant, determined by the properties of the dielectric (the SAM) and electrodes (the metal plate and the electrolyte). The associated maximum signal-to-noise ratio
(
δ
Q
)
2
σ
Q
2
=
N
(
V
T
-
V
D
)
2
A
f
2
c
0
2
2
k
B
T
(
C
+
C
P
)
(
14
)
increases with decreasing C and C P . Therefore, the small feature sizes of advanced CMOS generations offer advantages in realizing the smallest possible values of C and C P .
In a proper design, with nano-electrodes and switching transistors designed using minimum feature sizes, C and C P typically are of comparable value. Therefore, extending the CMOS process with a dedicated processes option for making sub-feature-size nano-electrodes only has limited advantages because it does not simultaneously reduce the parasitic capacitance C P and it does not reduce the area occupied by a sensor cell (resulting in a reduction of the fraction of sensitive surface area of the sensor). Therefore, sealing to the next more advanced CMOS generation is the obvious approach for further increasing the signal-to-noise ratio.
Concluding, capacitive biosensors for surface coverage fraction measurement may have large electrodes and can be implemented in old CMOS processes. Single-molecule biosensors may have the smallest possible electrodes and may be implemented in advanced CMOS generations.
In the following, some recognitions of the present inventor will be explained baaed on which exemplary embodiments of the invention have been developed.
Electronic biosensors are attractive because of their potential compatibility with CMOS processes. This allows to integrate the sensor electronics and additional features like an electronic interface to the outside world, programmable functions, and on-chip data storage and processing. In general such sensors consist of one or more electrodes immersed in the analyte. The analyte typically behaves like a liquid electrolyte. Capture probes are attached to the electrode surface, either directly or with some intermediate layer between the electrode surface and the capture probes. Examples of such intermediate layers are SAMs and dielectric layers, or combinations of the two.
Conventionally, sensor electrodes are much larger than the size of the molecules they should detect and/or recognize. However, scaling to nanometer-scaled electrodes may boost the performance of biosensors.
In the following, conventional capacitive bio-sensing will be mentioned.
FIG. 2 is a cross-sectional view of a metal-electrolyte capacitor 200 comprising a metal bottom plate 204 , a self-assembled monolayer (SAM) dielectric 202 , and an electrolyte top plate 206 , without (left) and with (right) a bio-molecule 208 captured on the SAM 202 .
The detection principle of a capacitive biosensor may be based on measuring the capacitance of the electrolytic capacitor 200 . The surface of the metal electrode 204 is covered with a thin (about 2-nm thick) SAM 202 of organic molecules that serves as a dielectric ( FIG. 2 , left). The electrode capacitance is
C=c 0 A (15)
where c 0 is the capacitance surface density and A is the electrode area. For typical alkane-thiol SAMs with thicknesses about a nanometer the value of c 0 is about 0.04 F/m 2 (the exact number may depend on details of the electrode surface like its roughness on a nanometer-scale, on the composition and density of the SAM, etc.). So for a nano-electrode 204 with an area of 0.015 μm 2 (a value that should be achievable in a 90-nm CMOS process) C would have a value of about 0.53 fF (1 fF=10 −‥ F).
The surface of the SAM 202 is chemically functionalised in such a way that it can capture bio-molecules 208 . Relevant bio-molecules 208 typically behave as dielectrics with dielectric constants similar to that of the SAM material 202 . Their size is in the range of 5 mm to 20 mm. When such a bio-molecule 208 is captured at the surface of the SAM 202 it replaces a certain volume of electrolyte 206 . In a simplified picture this event can be modeled as a replacement of a column of conducting electrolyte 206 with footprint area A f by an insulating dielectric 208 ( FIG. 2 , right). Assuming that the height of the column is much greater than the thickness of the SAM 202 (because typical bio-molecules 208 of interest are larger than the SAM 202 thickness), and neglecting fringing of the electric field near the intersection of the column wall and the SAM 202 , the resulting change in the electrode capacitance is approximately
Δ C=−c 0 A f (16)
Assuming that A f is of the order of magnitude of the square of the bio-molecule 208 size, typical values of |ΔC| can be expected in the range of 1-16 aF (1 aF=10 −18 F).
Such a small capacitance change is way outside the sensitivity range accessible with off-the-shelf high-end capacitance meters. Even Agilent's Precision Impendance Analyser 4294A can only measure a capacitance of 10 fF with an accuracy of 10% at an oscillator voltage of 0.5 Vrms (see diagram 300 in FIG. 3 ). But this usually requires long integration times (seconds or more) in a system that has to be carefully screened from interference by external sources. Furthermore, the required accurate calibration for parasitic capacitances may be practically difficult to achieve for a capacitor of which one electrode consists of a liquid (the electrolyte). And the high oscillator voltage may cause unknown nonlinear effects at the electrodes; the long integration times may cause problems with drift, 1/f-noise, etc. But even if one succeeds, the result is just a single capacitance measurement, done with a very expensive system.
Also recently presented high-resolution capacitance meter ICs like the AD7745, AD7746 or AD7747 of Analog Devices cannot measure the typical |ΔC| caused by the capture of a single bio-molecule 208 on the SAM 202 surface. With a conversion time in excess of 100 ms the standard deviation of the capacitance noise is 4.2 aF (see table 400 in FIG. 4 , lowest entry in 5 th column). Theoretically this would allow measuring a capacitance change of about 10 a F with a reasonable signal-to-noise ration. But this noise figure applies to an excitation (modulation) voltage of ±V DD /2. The exact value of the supply voltage V DD for this particular case is not specified in the IC's datasheet. But the lowest applicable supply voltage of the IC is 2.7 V, so the excitation voltage must be at least 2.7 V top-top, which is much too high for a SAM 202 with a thickness of about 2 nm.
Clearly the capacitance change caused by the capture of a single bio-molecule on the SAM 202 surface is too small for conventional equipment. Therefore the contributions of many molecules have to be added to arrive at a larger capacitance change that can be measured with a sufficient signal-to-noise ration in a reasonable time and at a low-enough modulation voltage (in the 100 mV range). For instance, depending on their size, 630-10,000 bio-molecules have to be captured for a capacitance change of 10 fF, a value which would just be resolvable with a reasonable accuracy with Agilent's 4294A instrument. As a result, even the lowest resolvable capacitance change always will be an average property of a large ensemble of captured bio-molecules. As a result of this averaging process a lot of information about the individual molecules is lost. Especially for a heterogeneous ensemble, consisting of a mix of multiple types of bio-molecules, the measured capacitance change hardly contains any information about the individual types of bio-molecules.
In the following, advantages of massive parallel single-molecule detection will be explained.
Capacitance measurements with electrodes that capture large quantities of bio-molecules give average properties of the captured molecules. As a result, only single-molecule signals common to at least a fraction of the captured ensemble are retained, while all other single-molecule signals are averaged out. In this way the signal-to-noise ration of the common signals can be improved, but all other information about the individual molecules gets lost. Information theoretical considerations show that this is not necessarily the best detection method. For example, variations in the binding details of individual molecules may cause blurring of features in the signals (for instance, inhomogeneous broadening of oxidation/reduction peaks in current-voltage curves, of features in impedance spectra, etc.). If all single-molecule signals could be acquired individually then more reliable detection and/or recognition of bio-molecules would be possible with statistical data processing techniques. Averaging is just one of many possible algorithms that can be applied to the data. But other algorithms can be applied as well (for instance, correction for systematic variations over the ensemble, classification of signals, pruning of bad samples, calculation of correlations, etc.).
An appropriate electronic biosensor can measure all bio-molecules individually. In this way the highest possible amount of information can be extracted from the molecules. For this purpose very small electrodes are needed. They should be placed in a high-density array to achieve high sensitivity (roughly proportional to the fraction of the array area that is sensitive to captured molecules).
The challenge for making biosensors with high-density arrays of individually accessible nano-scale electrodes is the proper segmentation of the addressing, control and read-out electronics into a local part that is repeated in every cell (nano-electrode and local electronics) and a peripheral part that is shared by all cells in a column or row.
Exemplary embodiments of the invention describe an architecture for a high-density capacitive biosensor array that implements such a segmentation in a very efficient way, and that can operate at high speed and very low power consumption. With the disclosed architecture sensors with single-molecule sensitivity can be manufactured.
Apart from an efficient segmentation it may also be important to consider power dissipation. In capacitive biosensor arrays modulation voltages have to be applied to the electrodes or to the counter electrode(s), and the AC currents induced in the electrodes have to be measured. In straightforward array architectures, where electrodes are selected with selection switches, the AC voltages and/or currents have to be transported through long row and/or column connection lines. This may lead to cross-talk between neighbouring lines or to loss of sensitivity because of large parasitic capacitances of the lines. Furthermore, modulating the voltages of long lines with large parasitic capacitance leads to high dynamic power dissipation. The architecture of embodiments of the invention does not suffer from all these drawbacks, and can be considered optimal in many respects. Furthermore, it can be implemented in standard advanced CMOS processes with only very minor process changes in a very last stage of the processing.
Next, further exemplary embodiments of the invention will be explained.
Embodiments of the invention may implement polished copper nano-electrodes for single-molecule biosensors in advanced CMOS processes. These copper nano-electrodes may serve as sub-micron metal plates of electrolytic capacitors. The dielectrics of the capacitors typical comprise or consist of SAMs, functionalized with capture probe molecules. The electrolyte plates typically comprise or consist of the analyte or a buffer solution above the sensor surface. Capacitors according to this construction are referred hereafter as “nano-electrode electrolytic capacitors”.
The above described FIG. 1 shows a configuration of a basic sensor principle according to an embodiment of the invention.
The node voltage V N of the metal plate 102 of a nano-electrode electrolytic capacitor C is controlled by the two NMOS switch transistors 106 , 108 , preferably of minimal dimensions (to limit their parasitic capacitances to a minimum). The electrolyte plate 118 of C is maintained at a fixed voltage V L , supplied to the liquid electrolyte 119 . The gate voltages of the two switch transistors 106 , 108 are controlled by the non-overlapping transfer and discharge clock signals Φ T and Φ D , respectively.
When Φ D is “high”, the capacitor's metal electrode 102 is discharged to the discharge potential V D ( FIG. 1 . t 1 ). After Φ D is made “low” again, the transfer clock Φ T is made “high”. Then the capacitor's metal electrode 102 is charged to the transfer voltage V T ( FIG. 1 , t 2 ). Finally, the transfer clock Φ T is made “low” again. Assuming that eventual transient peaks in V L (for instance, as a result of the electrolyte series resistance) have faded out at the end of the switching pulses, the net effect is the transfer of a charge
Q= ( C+C P )( V T −V D ) (17)
from the transfer terminal (biased at V T ) to the discharge terminal (biased at V D ), where C P is the total parasitic capacitance of the V N -node (equation (17) is a special case of equation (5) for N=1). This sequence is repeated with a transfer frequency f T , resulting in an average transfer current
I T =f T Q T (18)
In an array of cells 100 , the averaging may be done implicitly by the parasitic capacitance of the column line (the line that connects the transfer terminal, see below). This parasitic capacitance mainly consists of the sum of the parasitic capacitances of the transfer switch transistors of all non-selected cells connected to the same column line. For low frequencies (compared to f T /2) the cell effectively behaves like a resistor
R
T
=
1
f
T
(
C
+
C
P
)
(
19
)
The transfer current I T in principle is independent of the DC-value of electrolyte potential V L . This allows biasing the electrolyte at a convenient potential, for instance, where the average leakage current through the capacitor C is zero, thereby effectively eliminating net long-term electrochemical reactions at the metal/SAM/electrolyte junction.
Next, sensor arrays according to exemplary embodiments of the invention will be explained in more detail.
A single nano-electrode only has a very small area to capture bio-molecules. However, to be able to capture many bio-molecules in a short period of time, a large sensitive area may be needed. Therefore, many cells, each comprising or consisting of a nano-electrode electrolytic capacitor and two switch transistors, may be arranged in a dense two-dimensional array. A high density of cells may be achieved by sharing control, discharge and transfer lines between neighbouring cells in the arrays (control lines are the lines that control the gates of the switch transistors). Because only the part of a cell that is covered by the nano-electrode is sensitive, the fraction of insensitive area of the cell should be made as small as possible. This is another reason to use small switching transistors (apart from reducing their parasitic capacitances).
FIG. 5 shows an array 500 of nano-electrodes 102 and corresponding switch transistors 106 , 108 with shared control and discharge lines (horizontal rows 502 ) and transfer lines (vertical Columns 504 ).
In the array architecture of FIG. 5 , the cells 100 are arranged in orthogonal rows (each row comprising several control and discharge lines 502 ; however, in the following, the rows may also be indicated by reference numeral 502 ) and columns 504 . The cells 100 in the odd-numbered rows 502 are oriented upside down with respect to the cells 100 in the even-numbered rows. This allows sharing contact holes and discharge lines in the array layout. All cells 100 in the same row 502 are controlled by the same discharge clock signals Φ D,m and transfer clock signals Φ T,m , where m is the row index. As a consequence, all nano-electrode 102 electrolytic capacitors in a row 502 are addressed simultaneously. Their transfer currents can be measured via their respective column 504 lines I C,m , where n is the column index. With this parallel operation a high detection throughput can be obtained.
Selection of a particular row 502 may proceed by applying the appropriate clock signals and discharge voltage at its control (discharge and transfer clock) and discharge lines. The control lines of the non-selected rows may be biased at alternative appropriate control voltages, for instance, to disable these rows. The entire array or any other subset of rows is scanned by subsequently selecting the respective rows in an appropriate scan sequence.
Next, an advantageous array layout will be explained.
To achieve a high fraction of active sensor array surface it may be advantageous to choose a layout that is as dense as possible. FIG. 6 to FIG. 11 show a dense layout 600 , 700 , 888 , 900 , 1000 , 1100 that satisfies ail baseline CMOS design rules.
FIG. 6 shows a schematic (left) and layout (right) portion of the same part of a sensor array. Shown design layers: active 602 , poly 604 and contact 606 .
FIG. 7 shows a schematic (let) and layout (right) portion of the same part of a sensor array. Shown design layers: contact 606 and metal- 1 702 .
FIG. 8 shows a schematic (left) and layout (right) portion of the same part of a sensor array. Shown design layers: metal- 1 702 , via- 1 802 and metal- 2 804 .
FIG. 9 shows a schematic (left) and layout (right) portion of the same part of a sensor array. Shown: design layers: metal- 2 804 and via- 2 902 .
FIG. 10 shows a schematic (left) and layout (right) portion of the same part of a sensor array Shown design layers: via- 2 902 and metal- 3 1002 .
FIG. 11 shows a schematic (left) and layout (right) portion of the same part of a sensor array Shown design layers: metal- 3 1002 ) and via- 3 1102 (defining the nano-electrodes).
Active 602 and poly lines 604 are implemented as orthogonal straight lines of minimum possible width ( FIG. 6 ). In the vertical direction the poly line pitch and, consequently, the vertical cell pitch, is limited by the minimum contact-to-poly distance. Minimum-width metal- 1 column lines and minimum-area metal- 1 landing pads for the connections of the nano-electrodes and the discharge lines determine the horizontal cell pitch ( FIG. 7 ). Discharge lines are implemented in metal- 2 804 ( FIG. 8 ). The metal- 3 layer 1002 ( FIG. 9 to FIG. 11 ) is included to provide more freedom in the layout of the peripheral and input/output circuits. The via- 3 design layer 1102 of the baseline CMOS process is used here to define the nano-electrodes ( FIG. 11 ).
In the following, referring to FIG. 12 , a monolithically integrated sensor array 1200 according to an exemplary embodiment of the invention will be explained in more detail.
FIG. 12 shows a cross-sectional view through the sensor array 1200 according to an exemplary embodiment of the invention. FIG. 12 shows a cross-section along a column, through the nano-electrodes.
Up to and including metal- 3 1002 the process is identical to the original baseline CMOS process. The top-dielectric 1202 deviates from the low-K dielectric that typically is used at the via- 3 level 1102 . Instead a moisture-resistance layer 1202 , for instance, fluorosilicate glass, is used to prevent penetration of moisture into the layers below. Bond pad access holes (not shown in FIG. 12 ) are defined in the moisture barrier (at the via- 3 level 1102 ). The via- 3 holes and the bond pad access holes are filled simultaneously with a diffusion barrier and copper. A subsequent CMP (chemical mechanical polishing) procedure defines the polished surfaces of the nano-electrodes 1102 and the copper bond pads (not shown).
FIG. 12 shows a p-well 1202 of a silicon substrate. The various switch transistors are shown, more particularly their source/drain regions 1204 . Furthermore, a gate 1206 is shown, Contact plugs 606 are shown as well. Furthermore, a first metallization structure 702 can be seen. A first via 802 is indicated as well. A second metal layer 804 is provided above the first via layer 802 . A second via layer 902 is provided above the second metal layer 804 . A third metallization layer 1002 is provided above the second via layer 902 . A third via layer 1102 is provided above the third metallization layer 1002 . A column bias strap 1222 to connect the switching transistors to a charge transfer column line is shown as well. Furthermore, row bias lines 1224 (the discharge lines) are indicated. A sense pad 1226 is provided on a surface of the monolithically integrated structure 1200 . The surfaces of the via- 3 plugs 1102 are the sensitive areas, i.e., the sense pads 1226 . Beyond, moisture barriers 1202 are provided between adjacent sense pads 1226 .
Alternative embodiments allow creating even smaller cells. For instance, flipping the odd columns 504 around their vertical axis enables sharing the metal- 1 landing pads 702 for the discharge line connections of pairs of cells 100 in adjacent odd and even columns 504 . This creates some freedom to reduce the horizontal cell pitch by re-optimizing the metal- 1 layout 702 without violating the baseline CMOS design rules.
Using self-aligned contacts that overlap with the source/drain sidewall spacers of the switch transistors 106 , 108 enables reducing the vertical cell pitch. To avoid violating the metal- 1 minimum-area design rule the horizontal cell pitch has to be increased a bit. However, the resulting cell has a less rectangular (more square) shape, which reduces the cell area a bit.
Violating the metal- 1 702 minimum-area design rule may be used to reduce the horizontal cell pitch. This can be done, for instance, by fine-tuning the metal- 1 702 lithography procedure for a smaller but fixed metal- 1 702 landing pad area. Or the regular metal- 1 702 landing pads may be replaced by via-like holes, for instance, by means of a double-exposure metal- 1 702 litho-step or by other methods known to persons skilled in the art.
Apart from smaller cell sizes other improvements may be considered. For instance, violating the “enclosure of contacts by active” design rule, for instance, by using borderless contacts, may be used to reduce the width of the active lines. Although this does not reduce the cell size, it does reduce the parasitic capacitances between the poly lines and the source/drain junctions of the switching transistors, which in turn increases the dynamic range of the sensor and reduces its dynamic power dissipation.
Using separate discharge lines for odd and even rows may have other benefits, although at the expense of a larger vertical cell pitch. For instance, with separate discharge lines it is not necessary to exclude at least one row form the reconfigurable counter electrode described below.
Instead of via- 3 1102 an alternative via level (for instance, a via- 4 ) may be used to implement the nano-electrodes (and the bond pads). In this way more metal levels can be made available for signal or power routing in the array or in the peripheral electronics. Such an approach may be used, for instance, to strap the poly clock lines by metal lines to lower their series resistance.
Of course, combinations of optimizations and improvements may be combined whenever desired.
Next, an array operation and a reconfigurable counter electrode architecture will be explained in more detail.
As an example, the measurement of the capacitances in row 2 will be considered (see FIG. 5 ). Discharge and transfer clock signals similar to those of FIG. 1 are applied at the control lines Φ D,2 and Φ T,2 , and the required discharge voltage is applied at the discharge line V D,1 . (The index of the discharge lines identifies pairs of rows with shared discharge lines instead of individual rows. So rows 2 m and 2 m+ 1 share discharge line m.) In principle all other rows can be disabled by biasing their control lines Φ D,m and Φ T,m (m≠2) at a low potential to switch off their discharge and transfer switch transistors. This requires a separate counter electrode to bias the electrolyte voltage at a voltage V L . In the current context, the counter electrode denotes the electrode that provides the main electrical contact to the electrolyte. Although this is a feasible way of operating the sensor array 500 , it involves a couple of challenges.
1. The counter electrode has to be placed external to the sensor chip or it has to be integrated on a separate part of the chip. The first option may make the system more vulnerable for picking up interference signals from external sources like the mains grid, mobile phones, radio stations, etc. The second options may result in a larger chip area (unless the counter electrode can be segmented into pieces that can be distributed over the insensitive surface parts of the cells).
2. If the counter electrode has a different material composition or nano-scale structure than the nano-electrodes, the measured transfer currents may drift as a result of aging of the electrode/electrolyte junctions of the nano- and counter electrodes, and as a result of drift in the temperature, salt concentration or pH of the electrolyte.
3. A sensor system with an external counter electrode may be more complex than one with an integrated counter electrode. For example, it may require at least 1 bond pad to connect the counter electrode, which precludes, for instance, a pure system-on-chip (SOC) sensor system without external parts.
These challenges can be overcome with an alternative biasing scheme for the non-selected rows.
Again, as an example, the selection of row 2 will be considered. Discharge and transfer clock signals similar to those of FIG. 1 are applied at the control lines Φ D,2 and Φ T,2 , and the required discharge voltage is applied at the discharge line V D,1 . As before, all other transfer clock lines Φ T,m with m≠2 are biased at a low potential to switch off the corresponding transfer transistors 106 . but now all other discharge clock lines Φ D,m with m≠2 and m≠3 are biased at a high potential to switch on the discharge transistors 108 of the corresponding rows 502 . This connects their nano-electrodes 102 to their respective discharge lines. In the peripheral of the array 500 (not shown in FIG. 5 ) these discharge lines V D,k with k≠1 are all biased at the same reference voltage V R , for instance, by means of addressable pass-gates. In this way the nano-electrodes 102 of all non-selected rows 502 , except row 3 , effectively are connected in parallel to constitute one large reconfigurable counter electrode with exactly the same composition and nano-scale geometry as that of the selected nano-electrodes 102 in row 2 . The nano-electrodes 102 of row 3 have to be excluded from this reconfigurable counter electrode because their discharge line is already biased at the discharge voltage for row 2 . Therefore the discharge transistors 108 of row 3 have to switched off by applying a low voltage to the discharge clock line Φ D,3 . Such a reconfigurable counter electrode has a couple of advantages over a separate counter electrode:
1. For an array of M rows 502 (m=0, 1, . . . , M−1) the effective counter electrode area per selected cell is M−2 times the nano-electrode 102 area. So for large M the contact impedance between the counter electrode and the electrolyte is M−2 times less than that of all selected nano-electrodes 102 in parallel. As a result, the reconfigurable counter electrode effectively controls the electrolyte voltage.
2. After one complete row-scan through the whole array 500 the integrated net charge transport through all nano-electrodes 102 is zero, even if the leakage currents of selected nano-electrodes 102 are not exactly zero (this may happen, for instance, if the reference voltage V R is not exactly equal to the time average of the voltages of the selected nano-electrodes 102 ).
3. Because the reconfigurable counter electrode consists of a large amount of nano-electrodes 102 the effects of the captured bio-molecules on the individual nano-electrodes 102 are averaged into an overall effect that compensates for drift caused by the changing average surface composition of the nano-electrodes 102 .
Alternative algorithms to group a subset of non-selected nano-electrodes 102 into reconfigurable counter electrodes can be used as well. For instance, only odd-row 502 non-selected nano-electrodes 102 may be used in reconfigurable counter electrodes for odd selected rows 502 , and only even-row non-selected nano-electrodes 102 may be used for reconfigurable counter electrodes for even selected rows 502 . This approach would effectively split the ensemble of all nano-electrodes 102 into two completely independent sub-ensembles of odd- and even-row 502 nano-electrodes 102 , respectively. Such an approach can be advantageous for several reasons (for instance, increased symmetry within each sub-ensemble), but at the expense of an effectively doubled contact impedance between the counter electrode and the electrolyte. Alternatively, only non-selected nano-electrodes 102 of rows 502 in a certain close environment of the selected row 502 may be used. This may be advantageous if external factors cause a gradient in the nano-electrode 102 properties (for instance, during measurements in a flowing electrolyte), but at the expense of an even higher contact impedance between the counter electrode and the electrolyte. Of course, the flexibility in constructing complicated patterns of reconfigurable counter electrodes may be limited by the architecture of the peripheral circuits for the selection of rows 502 and the routing of control- and discharge-line voltages or signals.
Alternatively, in combination with an external counter electrode the reconfigurable counter electrode can also be used as an on-chip reconfigurable reference electrode to monitor the potential of the electrolyte. This effectively turns the reconfigurable counter electrode into a reconfigurable reference electrode with similar properties as that of the currently selected electrodes 102 and, consequently, with similar advantages as a reconfigurable counter electrode (for instance, compensation for drift caused by temporal changes in the composition, temperature, etc. of the electrolyte, or by aging, ware-out, etc. of the SAM layers). The measured electrolyte potential may be exported from the sensor chip, for instance, to control the potential of the external counter electrode.
Next, a row peripheral circuit according to an exemplary embodiment of the invention will be explained.
In the following, row peripheral circuits for arrays with the architecture of FIG. 5 will be described (that is, with shared discharge lines V D,m for even and odd rows 2 m and 2 m+ 1). Extension to alternative architectures (for instance, with separate discharge lines for every row) are possible.
The discharge lines V D,m and the discharge and transfer clock signals Φ D,2m , Φ T,2m , Φ D,2m+1 and Φ T,2m+1 of the row pairs m=0, 1, . . . , M/2 (where M is the number of rows) are controlled by a row peripheral circuit. Such a circuit may comprise or consist of an address decoder to select an even/odd row pair, and a signal gating circuit to switch an appropriate discharge voltage and appropriate control signal to the selected row pair. The architecture of a row address decoder may be similar to that for use in memories. Various architectures are possible for signal gating circuits, depending on the required flexibility.
For instance, in an embodiment simple MOS switches may be used to directly connect the discharge line of the selected row pair to a fixed discharge voltage, and all other discharge lines (of the nonselected row pairs) to an alternative voltage or to leave them floating. Simple logic gates may be used to select either the even or the odd row of the selected row pair by applying clock signals to the discharge and transfer clock lines of the chosen row, and to disable the other row of the selected row pair. The other rows of the non-selected row pairs can be either disabled for operation with an external counter or reference electrode or grouped into a reconfigurable counter or reference electrode according to the aimed array operation mode.
FIG. 13 shows a versatile row peripheral circuit 1300 with analog MUX switches 1302 , wherein FIG. 14 shows a table 1400 which describes the signal line. In other words, FIG. 14 is a description of the signals of row peripheral circuit 1300 in FIG. 13 .
Thus, FIG. 13 shows an example of a very versatile gating circuit 1300 consisting of five analog multiplexer (MUX) switches 1302 per row pair. The MUX switches 1302 of row pair m are controlled by the row pair select line RPS(m) 1304 originating from a row pair address decoder. The lines CT( 2 m ), CD( 2 m ), VD(m), Cd( 2 m+ 1) and CT( 2 m+ 1) in FIG. 13 correspond to the lines Φ T,2m , Φ D,2m , V D,m , Φ D,2m+1 and Φ T,2m+1 in FIG. 5 , respectively. Selecting row pair m puts its five MUX switches 1302 in the upper position while all other MUX switches 1302 (of the nonselected row pairs) remain in the lower position. This allows to apply five independent wave forms to the lines (CT( 2 m ), CD( 2 m ), VD(m), CD( 2 m+ 1) and CT( 2 m+ 1) via the row control bus lines, TES, DES, VDS, DOS and TOS, respectively, and to apply five alternative independent wave forms to the lines CT( 2 m′ ), CD( 2 m′ ), VD(m′), CD( 2 m′+ 1) and CT( 2 m′+ 1) of all non-selected row pairs, where m′=0, 1, . . . , M/2, m′≠m, via the row control bus lines TEN, DEN, VDN, DON and TON, respectively. In this way row 2 m can be selected by applying appropriate disabling voltages to the lines TOS and DOS. Alternatively, row 2 m+ 1 can be selected by applying appropriate clock signals to the lines TOS and DOS, while row 2 m is disabled by applying appropriate disabling voltages to the lines TES and DES. The array can be operated with an external counter or reference electrode by disabling all non-selected rows by putting appropriate disabling voltages on the lines TEN, DEN, VDN, DON and TON. Alternatively, the array can be operated in a reconfigurable counter or reference electrode mode by putting the counter or reference electrode voltage on the line VDN, appropriate enabling voltages on the lines DEN and DON, and appropriate disabling voltages on the lines TEN and TON. The row control bus lines can be connected directly to bond pads. Alternatively, they can be connected to an on-chip wave form generation circuit
Next, a column peripheral circuit according to an exemplary embodiment of the invention will be explained.
Typical values of the nano-electrode capacitance C in a 90-nm CMOS process are in the range of 0.5 fF. The parasitic capacitance C P typically has about the same size as C. The maximum transfer frequency F T is limited by the series resistance of the poly clock lines of the array and by their distributed load capacitance (mainly the gate capacitances of the switching transistors). As a result, for typical arrays with about 256 columns the maximum value of f T is about 40 MHz. The maximum amplitude |V T −V D | on the measurement node is limited to about 0.2 V by the breakdown and ware-out properties of the SAM and by parasitic electrochemical reactions that make take place at the nano-electrodes. As a result, typical values of the average charge transfer current I T is of the order of magnitude of 8 nA. This current should be measured with a resolution better than 8 pA to be able to resolve changes |δC| down to 1 aF caused by the capture of a single bio-molecule.
Real time monitoring of capturing single bio-molecules on the nano-electrodes requires a temporal resolution of about a second or better, depending on the concentration of the bio-molecules (if the capture event rate is too high the sample may have to be diluted to reduce the concentration). For an array consisting of 256 rows of nano-electrodes this means about 4 ms per row or less, provided that the average charge transfer currents of all columns are measured in parallel. To be able to do this, with a resolution better than 8 pA the measurements may be done on-chip.
FIG. 15 shows a column periphery circuit 1500 having a Reset voltage line 1502 , a Reset_not line 1504 , a Group select_not line 1506 , a Read currents line 1508 , a Reference voltage line 1510 , voltage clamps 1512 , a Read bus 1514 , a Read multiplexer 1516 , integration caps and read out portion 1518 , and Reset MOSTs 1520 .
Massive parallel on-chip measurement of the average charge transfer currents can be done in multiple ways. In the embodiment of FIG. 15 , the transfer voltage on the column line is controlled by the source follower T 1 and the reference voltage line. The drain current of the source follower T 1 is integrated on the gate capacitance of transistor T 2 after resetting the gate voltage by the reset switch T 3 . At the end of the integration period the drain of T 2 is connected to the read bus by closing the read MUX switch T 4 . Now the read current (that is, the drain current of T 2 , which is a measure of the charge integrated on the gate capacitance of T 2 ) can be measured via the corresponding read bus line. Grouping of columns allows multiplexing of read currents over the read bus lines. In that case resetting preferably should also be done per group to arrive at a equal integration period for the groups. The read bus lines can be connected directly to separate bond pads to measure the corresponding read currents with off-chip read electronics. Alternatively, the read bus lines can be connected to on-chip buffer circuits or current-to-voltage converters that export the converted analog signals from the chip via bond pads. Alternatively, the read currents can be digitized by on-chip analog-to-digital converters (ADCs) and exported from the sensor chip via a digital bus.
At an average charge transfer current of 8 nA and an integration time of 4 ms the gate capacitance would have to be equal to 64 pF to limit the voltage swing on the gate capacitance of T 2 to about 0.5 V (a typical value for a supply voltage of 1.2 V). This would require a gate are of T 2 of about 4500 square microns, which is comparable to the area of a bond pad. This is very large because such a large transistor would be needed for every column. This challenge can be solved by splitting the integration period of 4 ms into multiple smaller integration periods. For instance, for an integration period of 40 microseconds a gate area of 45 square microns is required. However, shorter integration periods correspond to wider signal bandwidth and, consequently, higher noise. Therefore, multiple sequential measurements performed with these shorter integration periods have to be averaged, for instance, on an external computer or with on-chip digital circuits.
In an alternative embodiment of a column periphery circuit the PMOS transistor T 2 in FIG. 15 is replaced by a separate integration capacitor and a NMOS source follower transistor. After resetting the voltage on the integration capacitor with the reset transistor T 3 the drain current of transistor T 1 is integrated on the integration capacitor. The voltage over the integration capacitor is measured by the source follower transistor. The source follower transistor may be selected by the selection transistor T 4 . Alternatively, the selection transistor T 4 may be replaced by a NMOS transistor.
Next, calibration and self-referencing will be mentioned.
Apart from wide-band noise that can be reduced by averaging sequential measurements, the read current may also contain low-frequency noise (often referred to as 1/f-noise) generated by the DC currents flowing through transistors T 1 , T 2 and T 4 during the integration period or during the read-out via the read bus (the reset transistor T 3 and the discharge and charge transfer transistors of the selected cell do not generate low-frequency noise if the reset, discharge and charge transfer transients are allowed to decay sufficiently at the end of each switching event). This low-frequency noise typically cannot be reduced by averaging subsequent measurements because of its 1/f-like noise power spectral density. Instead, a calibration measurement may be done. For this purpose calibration rows can be used.
Calibration rows may have the same architecture as the active rows, but without nano-electrodes connected to their measurement nodes. As a result, their average charge transfer current is determined only by the parasitic capacitances of their measurement nodes. Because these parasitic capacitances remain constant over time they can be used to generate reproducible reference currents for the columns.
To suppress low-frequency noise, one or more calibration rows may be selected simultaneously, and the total average charge transfer current in every column is measured by means of the column peripheral circuit. Preferably the number of simultaneously selected calibration rows should be chosen in such a way that the total calibration charge transfer current in a column is closest to the charge transfer current of an active row (that is, a row with connected nano-electrodes). Because the nano-electrode capacitance C and the parasitic C P typically have about similar values, typically two calibration rows have to be measured simultaneously to generate a reference current comparable to the charge transfer current generated by an active cell. If necessary, the reference current can be fine-tuned by means of the charge transfer frequency.
To be able to resolve the small capacitance changes |δC| caused by single-molecule capturing events at the nano-electrodes, the measured capacitances of the individual nano-electrodes can be compared to the average capacitance of a row or set of rows. In this way systematic temporal drift in the nano-electrode capacitances C, for instance, as a result of gradually changing dielectric properties of the SAM layers, can be cancelled (such drift components in general cannot be cancelled by using a reconfigurable counter electrode because the total capacitance of the selected nano-electrodes is much less than that of a typical reconfigurable counter electrode.
In case of a source-follower column periphery circuit the low-frequency noise of source follower transistor can be suppressed further by employing a correlated double sampling strategy. After measuring the voltage on the integration capacitor at the end of the integration cycle the reset transistor T 3 is closed to discharge the integration capacitor. While the reset transistor is still closed the voltage on the discharged integration capacitor is measured again (a second time) to serve as a reference for the first measurement. By subtracting the second measurement from the first, the low-frequency noise of the source follower transistor can be eliminated to a large extent. Such a correlated double sampling measurement strategy can be combined with calibration measurements like explained before.
In the following, a system-level architecture according to an exemplary embodiment of the invention will be explained.
FIG. 16 shows a system-level architecture 1600 according to an exemplary embodiment of the invention.
The sensor array 500 is controlled by a row peripheral circuit 1602 , and the average charge transfer currents of the columns are measured by a column peripheral circuit 1604 . The row peripheral circuit 1602 and the column peripheral circuit 1604 connect to a wave form generator (WG) and control block 1606 that is connected to an input-output (IO) bus 1608 . The IO bus 1608 inputs the addresses and other control signals and outputs the read currents and other optional output signals. Alternatively, the wave form generator may be off-chip.
FIG. 17 shows a system-level sensor-architecture 1700 according to another exemplary embodiment of the invention.
In FIG. 17 , separate upper and lower column peripheral circuits 1702 , 1704 are provided for even and odd columns, respectively. This architecture may be used to ease the layout of the column peripheral circuit (this may be advantageous because the column pitch typically is smaller that the row pitch).
FIG. 18 shows a system-level sensor-architecture 1800 according to still another exemplary embodiment of the invention.
In FIG. 18 , calibration rows 1902 are provided which occupy part of the row address space. Additional measures may have to be taken to be able to select more than one calibration row 1802 simultaneously.
FIG. 19 shows a system-level sensor-architecture 1900 according to yet another exemplary embodiment of the invention.
In FIG. 19 , the calibration rows 1802 are implemented as a separate part of the array that falls outside the row address space 500 .
Although embodiments of the invention have been described assuming NMOS switching transistors in the sensor array it is clear that alternative embodiments based on PMOS switch transistors are possible as well.
By sweeping the charge transfer frequency a spectral scan can be made to measure frequency-dependent dielectric properties of individual captured molecules.
Instead of operating the sensor array with clock signals to translate nano-electrode capacitances into charge transfer currents, the sensor may also be used to directly measure DC currents of nano-electrodes by statically disabling the discharge transistors and enabling the charge transfer transistors of the selected row. This may be used to operate the sensor as a massive parallel electrochemical biosensor, for instance to measure DC currents generated by single-molecule enzymes or redox couples captured on the nano-electrodes. Such enzymes or redox couple molecules may be sued as labels to detect bio-molecules.
By statically enabling the discharge transistors and disabling the charge transfer transistors of the selected row, the capturing of molecules on the selected nano-electrodes may be influenced by applying an appropriate voltage on the discharge line of the selected row pair (or row, in case of an architecture with separate discharge lines for every row). During this process the other rows may be used as reconfigurable counter electrodes. By scanning through the rows the capturing of molecules may be influenced on all rows of the sensor. This method may be extended to individual nano-electrodes by applying the required bias voltages via the charge transfer lines instead of the discharge lines. For this purpose the column peripheral circuit may be modified or extended in such a way that difference voltages can be applied to every individual column line. such a way of operation may be used, for instance to enhance the concentration of positively or negatively charged molecules at the selected nano-electrode surfaces to enhance or disable their capturing. For instance, the capturing of negatively charged DNA oligomers (small fragments of DNA) may be influenced this way.
In the following, advantages of exemplary embodiments of the invention will be explained:
Massive parallel single-molecule detection Extracting maximum possible information from ensemble of captured bio-molecules Temporal resolution at single-molecule level to measure reaction kinetics Manufacturability in standard CMOS process with minor BEOL modifications Using discharge and charge transfer transistor of the same conductivity type (both NMOS and PMOS) allows to make much denser cell layout than using transistors of opposite conductivity type “Natural” scalable; benefiting form Moore's Law Only one plate of the nano-electrode capacitors is connected to the switching elements in the cell. The other plate (the electrolyte) is shared. This enables the extremely compact cell architecture. Ultra-low power dissipation. In the sensor array dynamic power is only dissipated in the selected row. All non-selected rows only “see” DC voltages (no dynamic power dissipation) and all columns lines only carry very low DC currents. Virtually no cross talk between adjacent column lines because they effectively only carry DC currents Almost perfect charge balancing possible with reconfigurable counter electrode Reconfigurable counter and reference electrodes have (almost equal composition and history as active electrodes No long signal paths with (on-chip) reconfigurable counter electrodes: minimal pick-up of interference from external sources (radio stations, mains, mobile phones, etc.) Full CMOS biosensor allows embedding additional functions (A-to-D) converter, microcontroller, memory, etc.) at the lowest price (possibility to design with CMOS library blocks or IP blocks, perhaps modified at the highest metal levels)
Finally, it should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be capable of designing many alternative embodiments without departing from the scope of the invention as defined by the appended claims. In the claims, any reference signs placed in parentheses shall not be construed as limiting the claims. The words “comprising” and “comprises”, and the like, do not exclude the presence of elements or steps other than those listed in any claim or the specification as a whole. The singular reference of an element does not exclude the plural reference of such elements and vice-versa. In a device claim enumerating several means, several of these means may be embodied by one and the same item of software or hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
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A sensor device has an arrangement of plural sensors for sensing an analyte which is in at least one of liquid phase or a suspension or a gel. Each sensor includes a nano-electrode and is configured to sense the presence of a particle localized to or bound to the nano-electrode. The sensor is configured to discriminate in real-time the binding of particles to respective nano-electrodes.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates generally to handheld electronic devices and, more particularly, to a handheld electronic device that enables a user to establish a prioritized list of preferred networks to be used in roaming situations. The invention also relates to an improved method of establishing a prioritized list of preferred networks to be used by a handheld electronic device in roaming situations.
[0003] 2. Description of the Related Art
[0004] Numerous types of handheld electronic devices are known. Examples of such handheld electronic devices include, for instance, personal data assistants (PDAs), handheld computers, two-way pagers, cellular telephones, and the like. Such handheld electronic devices are generally intended to be portable and thus are relatively small.
[0005] Many handheld electronic devices include and provide access to a wide range of integrated applications, including, without limitation, email, telephone, short message service (SMS), multimedia messaging service (MMS), browser, calendar and address book applications, such that a user can easily manage information and communications from a single, integrated device. These applications are typically selectively accessible and executable through a user interface that allows a user to easily navigate among and within these applications.
[0006] Many handheld electronic devices include wireless telephone and data (e.g., email, SMS, Internet) functionality. As is known in the art, wireless services, such as telephone and data services, are provided by way of an air interface involving radio frequency (RF) communications between wireless enabled equipment, such as a handheld electronic device described above, and one or more networks of land based radio transmitters or base stations. Each such network is commonly referred to as a public land mobile network (PLMN). PLMNs interconnect with other PLMNs and the public switched telephone network (PSTN) for telephone communications or with Internet service providers for data and Internet access.
[0007] In order to use wireless communications functionality, a user must subscribe with a wireless service provider or operator. The subscription permits the user to utilize the PLMN operated by the service provider or operator (referred to as the “home PLMN”). As is known in the art, roaming is a service offered by PLMN operators which allows a subscriber to use his or her wireless enabled equipment while in the service area of another operator (and outside of the user's home PLMN). Roaming requires an agreement between operators of technologically compatible systems to permit customers of either operator to access the other's PLMN. Service providers or operators typically charge a higher per-minute fee for calls placed outside their home calling or coverage area (the area serviced by their PLMN).
[0008] As is also known in the art, devices, such as handheld electronic devices, that include wireless functionality, such as telephone and data functionality, are provided with a subscriber identity module card (SIM card). A SIM card is a small printed circuit board that contains subscriber details, including data that identifies the user to the service provider, security information, and memory for a personal directory of numbers. In addition, the SIM card stores a pre-set, prioritized list of particular PLMNs to be used by the device in roaming situations. The particular PLMNs included in the list are normally based on the marketing preferences of a particular operator. However, as will be appreciated, different PLMNs have differing charges associated with them and offer different levels of reliability and service quality. Thus, a user may desire to use PLMNs other than those pre-stored in the SIM card and/or use PLMNs in a different order of priority than that specified in the SIM card based on issues of cost, reliability, and service quality, among others. Thus, there is a need for an improved handheld electronic device that enables a user to establish a prioritized list of preferred PLMNs to be used in roaming situations.
SUMMARY OF THE INVENTION
[0009] An improved handheld electronic device and an associated method enable a user to selectively establish a prioritized list of preferred PLMNs to be used in roaming situations. As a result, a user is able to select particular PLMNs based on issues of PLMN cost, reliability, and service quality, among others.
[0010] These and other aspects of the invention are provided by a wirelessly enabled handheld electronic device including an input apparatus, a communications subsystem, a display, a processor, and a memory storing one or more applications executable by the processor. The one or more applications are adapted to display a listing of one or more known networks for which network information is stored in the memory, scan for one or more available networks, which are networks available for use in conducting wireless communications in the area in which the handheld electronic device is currently located, and display a listing of the available networks. The applications are also adapted to enable the entry of information relating to one or more manually entered networks. Furthermore, the applications are adapted to (1) enable the addition of one or more preferred networks to a preferred network list wherein the preferred networks are one or more of: (i) certain of the known networks selected from the listing of known networks, (ii) certain of the available networks selected from the listing of available networks, and (iii) the manually entered networks; (2) enable the assignment of a priority value to each of the preferred networks; and (3) utilize one or more of the preferred networks for performing wireless communications when the handheld electronic device is in a roaming situation, wherein the preferred networks are utilized in a priority order that is based on the priority value assigned to each of the preferred networks.
[0011] The communications subsystem may include a SIM card, wherein the applications are further adapted to store the preferred network list in the SIM card. The preferred network list also preferably includes network information for each of said preferred networks, such as the MNC and MCC for each of the preferred networks. The handheld electronic device may also include a thumbwheel that may be used to scroll up and down for data selection purposes.
[0012] Preferably, the preferred network list is displayed in a display order corresponding to the priority order. In one case, the priority value of a first one of the preferred networks is a highest priority, and the priority value of a second one of the preferred networks is a lowest priority, and the priority order is sequential beginning with the first one of the preferred networks and ending with the second one of the preferred networks. The applications may be further adapted to enable the movement of a selected one of the preferred networks on the display to create an altered display order, wherein the priority value assigned to one or more of the preferred networks is changed such that the priority order corresponds to the altered display order. In addition, the one or more applications may be further adapted to enable the deletion of a selected one of the preferred networks on the display to create an altered display order, wherein the priority value assigned to one or more of the preferred networks is changed such that the priority order corresponds to the altered display order.
[0013] According to another aspect of the invention, a method of establishing a prioritized list of networks to be used by a handheld electronic device in roaming situations is provided. The method includes displaying a listing of one or more known networks upon request of a user of the handheld electronic device, with each of the known networks having network information stored by the handheld electronic device, scanning for one or more available networks upon request of the user, with each of the available networks being available for use in conducting wireless communications in an area in which the handheld electronic device is currently located, and displaying a listing of the available networks. The method further includes receiving information relating to one or more manually entered networks when input into the handheld electronic device by the user. Finally, the method includes adding one or more preferred networks to a preferred network list, the preferred networks being one or more of: (i) certain of the known networks selected from the listing of known networks, (ii) certain of the available networks selected from the listing of available networks, and (iii) the manually entered networks, and assigning a priority value to each of the preferred networks, wherein one or more of the preferred networks are utilized for performing wireless communications when the handheld electronic device is in a roaming situation in a priority order that is based on the priority value assigned to each of the preferred networks.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] A full understanding of the invention can be gained from the following Description of the Preferred Embodiment when read in conjunction with the accompanying drawings in which:
[0015] FIG. 1 is a front view of an improved handheld electronic device in accordance with the invention;
[0016] FIG. 2 is a block diagram of the handheld electronic device of FIG. 1 ; and
[0017] FIGS. 3 through 17 are exemplary views of a portion of the display of the handheld electronic device of FIGS. 1 and 2 that illustrate a routine or routines for enabling a user to selectively establish a prioritized list of preferred PLMNs to be used in roaming situations according to the invention.
[0018] Similar numerals refer to similar parts throughout the specification.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0019] An improved handheld electronic device 4 in accordance with the invention is depicted generally in FIGS. 1 and 2 . The handheld electronic device 4 includes a housing 8 , a display 12 , an input apparatus 16 , and a processor 20 ( FIG. 2 ) which may be, without limitation, a microprocessor (μP). The processor 20 is responsive to inputs received from the input apparatus 16 and provides outputs to the display 12 . While for clarity of disclosure reference has been made herein to the exemplary display 12 for displaying various types of information, it will be appreciated that such information may be stored, printed on hard copy, be computer modified, or be combined with other data, and all such processing shall be deemed to fall within the terms “display” or “displaying” as employed herein. Examples of handheld electronic devices are included in U.S. Pat. Nos. 6,452,588 and 6,489,950, which are incorporated by reference herein. The handheld electronic device 4 is of a type that includes a wireless telephone capability which, as will be described in greater detail below, enables a user to selectively establish a prioritized list of preferred PLMNs to be used in roaming situations in accordance with the invention. As used herein, the terms “phone” and “telephone” shall refer to any type of voice communication initiated and conducted over a wired and/or wireless network.
[0020] As can be understood from FIG. 1 , the input apparatus 16 includes a keyboard 24 having a plurality of keys 26 , and a rotatable thumbwheel 28 . As used herein, the expression “key” and variations thereof shall refer broadly to any of a variety of input members such as buttons, switches, and the like without limitation. The keys 26 and the rotatable thumbwheel 28 are input members of the input apparatus 16 , and each of the input members has a function assigned thereto. As used herein, the expression “function” and variations thereof can refer to any type of process, task, procedure, routine, subroutine, function call, or other type of software or firmware operation that can be performed by the processor 20 of the handheld electronic device 4 .
[0021] As is shown in FIG. 2 , the processor 20 is in electronic communication with memory 44 . Memory 44 can be any of a variety of types of internal and/or external storage media such as, without limitation, RAM, ROM, EPROM(s), EEPROM(s), and the like, that provide a storage register for data storage such as in the fashion of an internal storage area of a computer, and can be volatile memory or nonvolatile memory. The memory 44 further includes a number of applications executable by processor 20 for the processing of data. The applications can be in any of a variety of forms such as, without limitation, software, firmware, and the like, and the term “application” herein shall include one or more routines, subroutines, function calls or the like, alone or in combination.
[0022] As is also shown in FIG. 2 , processor 20 is in electronic communication with communications subsystem 45 . Communications functions for handheld electronic device 4 , including data and voice communications (wireless telephone), are performed through communications subsystem 45 . Communications subsystem 45 includes a transmitter and a receiver (possibly combined in a single transceiver component), a SIM card, and one or more antennas. Other known components, such as a digital signal processor and a local oscillator, may also be part of communications subsystem 45 . The specific design and implementation of communications subsystem 45 is dependent upon the communications network in which handheld electronic device 4 is intended to operate. For example, handheld electronic device 4 may include a communications subsystem 45 designed to operate with the Mobiltex™, DataTAC™ or General Packet Radio Service (GPRS) mobile data communication networks and also designed to operate with any of a variety of voice communications networks, such as AMPS, TDMA, CDMA, PCS, GSM, and other suitable networks. Other types of data and voice networks, both separate and integrated, may also be utilized with handheld electronic device 4 . Together, processor 20 , memory 44 , and communications subsystem 45 may, along with other components (having various types of functionality), be referred to as a processing unit.
[0023] In FIG. 1 , the display 12 is depicted as displaying a home screen 43 that includes a number of applications depicted as discrete icons 46 , including, without limitation, an icon representing a phone application 48 , an address book application 50 , a messaging application 52 which includes email, SMS and MMS applications, and a calendar application 54 . In FIG. 1 , the home screen 43 is currently active and would constitute a portion of an application. Other applications, such as phone application 48 , address book application 50 , messaging application 52 , and calendar application 54 can be initiated from the home screen 43 by providing an input through the input apparatus 16 , such as by rotating the thumbwheel 28 and providing a selection input by translating the thumbwheel 28 in the direction indicated by the arrow 29 in FIG. 1 .
[0024] FIGS. 3 through 17 are exemplary depictions of display 12 of handheld electronic device 4 that illustrate a routine or routines performed by processor 20 for enabling a user to selectively establish a prioritized list of preferred PLMNs to be used in roaming situations according to the invention. By utilizing the invention, a user of handheld electronic device 4 is able to override the list of particular PLMNs to be used by the handheld electronic device 4 in roaming situations that is pre-stored in the SIM card forming a part of communications subsystem 45 by establishing and storing a user selected and prioritized list of PLMNs to be used by the handheld electronic device 4 in roaming situations. In the particular embodiment shown in FIGS. 3 through 17 , this list is called the “My Preferred Network List.”
[0025] FIG. 3 is an exemplary depiction of display 12 showing an “Options-Network” screen 50 generated by an operating application of handheld electronic device 4 which provides a user with information and options relating to the PLMNs used or to be used by handheld electronic device 4 . As seen in FIG. 3 , menu 52 may be accessed from “Options-Network” screen 50 in a known manner using input apparatus 16 . Menu 52 includes an item 54 entitled “My Preferred Network List.” When a user desires to create a prioritized list of PLMNs to be used by handheld electronic device 4 in roaming situations according to the invention, the user first selects item 54 . When a user does so, a “Preferred Network List” screen 56 as shown in FIG. 4 is displayed on display 12 . “Preferred Network List” screen 56 displays a prioritized listing 58 of PLMNs selected by the user as described herein to be used by handheld electronic device 4 in roaming situations. As seen in FIG. 4 , the listing 58 is initially empty. To add a PLMN to the listing 58 , the user accesses menu 60 in a known manner and selects item 62 entitled “Add Network.” Next, as seen in FIG. 6 , “Add Network” screen 64 is displayed to the user on display 12 . At this point, the user has three options to choose from for adding a PLMN to the listing 58 . Each option is described below.
[0026] In the first option, a user can manually add a PLMN to the listing 58 by entering identifying information for the PLMN into the data fields provided on “Add Network” screen 64 using input apparatus 16 . In particular, to add a particular PLMN to the listing 58 , the user must enter the mobile network code (MNC) for the PLMN at field 66 , the mobile country code (MCC) for the PLMN at field 68 , and the priority the user wishes to assign to that PLMN at field 70 . The respective priorities assigned to the PLMNs listed on listing 58 determines the order in which the PLMNs are to be used by handheld electronic device 4 , if available, in roaming situations.
[0027] In the second option, the user can add a PLMN to the listing 58 by selecting the PLMN from a group of “known networks” stored in memory 44 of handheld electronic device 4 (the MNC and MCC is stored for each such “known network”). To do so, the user accesses menu 72 in a known manner and selects item 74 entitled “Select From Known Networks.” Next, as seen in FIG. 8 , “Find” screen 76 is displayed on display 12 . “Find” screen 76 includes a listing 78 of all of the “known networks” stored by memory 44 of handheld electronic device 4 . A user may then identify for selection a particular PLMN from listing 78 by scrolling down listing 78 in a known manner using input apparatus 16 or by typing a portion of or all of the name of the PLMN using input apparatus 16 as shown in FIG. 9 . Once a particular PLMN has been identified, a user may then select the PLMN for inclusion in the listing 58 by accessing menu 80 in a known manner and selecting item 82 entitled “Select Network” as shown in FIG. 10 . When this is done, “Add Network” screen 64 is displayed on display 12 as shown in FIG. 11 , and information for the PLMN is automatically provided in fields 66 (MNC) and 68 (MCC), as well as field 84 , which is the name of the PLMN. The user must then enter information into field 70 using input apparatus 16 to establish the priority to be assigned to the PLMN. Once all of the information has been entered, the selected PLMN may be saved to the listing 58 by accessing menu 72 in a known manner and selecting item 86 entitled “Save” (which item was added to menu 72 because listing 58 is no longer empty; compare FIG. 7 ) as shown in FIG. 12 . As seen in FIG. 13 , when saved, the selected PLMN appears in listing 58 . When all the desired PLMNs have been added to and prioritized in the listing 58 , listing 58 may be saved to the SIM card forming part of communications subsystem 45 by accessing menu 60 in a known manner and selecting item 88 entitled “Save” (which item was added to menu 60 because listing 58 is no longer empty; compare FIG. 5 ) as seen in FIG. 14 . Note that, for illustrative purposes, FIG. 14 assumes that additional PLMNs have been added to the listing 58 , and thus the listing 58 shown in FIG. 14 includes additional PLMNs not shown in FIG. 13 . Once the listing 58 is saved to the SIM card, it, and not the pre-stored list described above, is used to determine which and in what order PLMNs are to be used by handheld electronic device 4 , if available, in roaming situations. In other words, listing 58 overrides the pre-stored list of PLMNs provided with the SIM card.
[0028] In the third option, the user can add a PLMN to the listing 58 by selecting the PLMN from a group of “available networks,” which handheld electronic device 4 is able to locate from its current location using communications subsystem 45 and a known network scanning procedure. To do so, the user accesses menu 72 in a known manner and selects item 90 entitled “Select From Available Networks” as shown in FIG. 15 . Next, handheld electronic device 4 performs a scan to locate the current “available networks.” As seen in FIG. 16 , while this is being done, a dialog box 92 is displayed on display 12 to inform the user that the scan is taking place. Once the scan is completed, “Find” screen 76 as seen in FIG. 17 is displayed on display 12 and includes a listing 94 of all of the “available networks” located during the scanning procedure. The user may then select a particular PLMN for inclusion in the listing 58 and save the listing 58 to the SIM card in the manner described in connection with FIGS. 8 through 14 above. In one embodiment, “available networks” will consist of only “known networks” stored by memory 44 . Alternatively, any network located during the scan may be a “available network.” Again, once the listing 58 is saved to the SIM card, it, and not the pre-stored list provided in the SIM card described above, is used to determine which and in what order PLMNs are to be used by handheld electronic device 4 , if available, in roaming situations.
[0029] According to an aspect of the invention, the user may easily reorder, and thus change the priority of, the PLMNs listed in listing 58 by selectively moving their location in listing 58 . Specifically, according to one embodiment, if a user wants to move a PLMN appearing on listing 58 (for example, the “ABA Network”), the user can, as shown in FIG. 18 , identify the PLMN to be moved on “Preferred Network List” screen 56 using the input apparatus in a known manner, access menu 60 therefrom, and select item 96 entitled “Move.” When this is done, the identified PLMN is highlighted as shown in FIG. 19 . The identified and highlighted PLMN may then be moved to another location on the listing 58 using input apparatus 16 , preferably, although not necessarily, by rotating thumbwheel 28 (alternatively, various keys, such as “up” and “down” arrow keys, may be used). Once the identified PLMN is in the desired location on listing 58 , its location may be confirmed using input apparatus 16 , preferably, although not necessarily, by pressing thumbwheel 28 , at which time the moved PLMN will no longer be highlighted. As seen in FIG. 20 , once the PLMN is moved, the PLMNs in listing 58 are automatically reordered and renumbered, meaning their assigned priority is changed, if necessary. If desired, the listing 58 as currently appearing in “Preferred Network List” screen 56 may then be saved to the SIM card (with the new assigned priorities) in the manner described in connection with FIGS. 8 through 14 . In addition to moving PLMNs listed in listing 58 , particular PLMNs may be deleted from listing 58 and/or stored information (the information in fields 66 , 68 , 70 and 84 ) for particular PLMNs may be displayed on display 12 by identifying the particular PLMN as described above and then selecting the appropriate item (“Delete” or “View”) in menu 60 shown in FIG. 18 . When a PLMN is deleted from listing 58 , the remaining PLMNs in listing 58 are automatically reordered and renumbered, meaning their assigned priority is changed, if necessary.
[0030] Thus, the invention provides a handheld electronic device that enables a user to selectively establish a prioritized list of preferred PLMNs to be used in roaming situations. In this manner, a user is able to select and prioritize particular PLMNs based on issues of PLMN cost, reliability, and service quality, among others, thereby saving the user money and/or enhancing performance of the handheld electronic device.
[0031] While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the claims appended and any and all equivalents thereof.
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A handheld electronic device adapted to display a listing of known networks, scan for available networks, display a listing of the available networks and enable the entry of information relating to manually entered networks. In addition, the device is adapted to (1) enable the addition of preferred networks to a preferred network list wherein the preferred networks are one or more of: (i) certain of the known networks selected from the listing of known networks, (ii) certain of the available networks selected from the listing of available networks, and (iii) the manually entered networks; (2) enable the assignment of a priority value to each of the preferred networks; and (3) utilize the preferred networks for performing wireless communications when the device is in a roaming situation, wherein the preferred networks are utilized in a priority order that is based on the priority value assigned to each of the preferred networks.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method and apparatus for manufacture of a continuous sheet of flat glass by supporting molten glass on a pool of molten metal and advancing it along the surface of the pool of molten metal while cooling it to form a continuous sheet of flat glass. More particularly, this invention relates to a method for controlling the flow of tin which is drawn along with the molten glass as it advances through the molten metal bath.
2. Discussion of the Prior Art
It has been proposed in the prior art that various types of barriers or dams be utilized to restrict the flow of the metal in the molten metal bath as the float glass is formed and cooled on the bath. The references described below are representative of the devices which are pertinent to the instant invention.
The U.S. Pat. No. 3,930,829 to Sensi discloses an arrangement of dams both in the transverse and longitudinal direction to control the movement of tin in a molten bath for glass formation. The dams of Sensi are extended from the bottom of the chamber and may closely approach the surface of the glass.
U.S. Pat. No. 3,930,828 to Kunkle discloses another system of dams to divide the molten metal of a float glass-forming tank into compartments which may be individually cooled or heated in order to regulate the forming process.
U.S. Pat. No. 3,607,199 to Itakura discloses a U-shaped dam near the forming region that acts to control the flow of molten metal in a region directly adjacent an entry location of glass into a float bath.
U.S. Pat. No. 3,483,617 to Lawrenson discloses a series of buoyant depressible barriers which are adapted to raise against the bottom of float glass being formed and thereby restrict the movement of tin or other molten metal longitudinally without interfering with the advancement of float glass through the bath.
The above systems while aiding in control of tin movement which introduces some defects in float glass do not effectively inhibit longitudinal distortion which is believed caused by the movement of tin within the bath closely adjacent the lower surface of the glass as it moves through the bath .This tin becomes unevenly heated in the transverse direction and leads to the longitudinal distortion defect.
The system of Lawrenson while inhibiting some flow of metal closely with the bottom of the glass has not proven feasible as the barriers may tend to cause defects when they scrape on the bottom surface of the floating glass as it hardens. Further, at times the barriers are depresed by the flow of the tin or other molten metal and therefore allow the tin flowing with the glass to pass over them and therefore do not prevent longitudinal defects.
SUMMARY OF THE INVENTION
It is an object of this invention to overcome the disadvantages of the prior art.
It is an additional object of this invention to produce flat glass with few defects.
It is an additional further object of this invention to produce glass without centerline defects.
It is another object of this invention to produce flat glass without micro-distortions.
It is another object of this invention to produce glass of substantially uniform thickness in the transverse direction across the width of a continuous sheet or ribbon of glass.
It is an additional object of this invention to produce flat glass with fewer optical defects.
These and other objects of the invention are accomplished generally by providing at least one barrier in the tin or other molten metal bath on which the float glass is formed. The barrier of the invention is situated as close to the glass as possible without having the glass stick to the barrier and has a surface of grooves which radiate from the direction of travel of the glass. These cross-cut or intersecting grooves act to direct the tin which is being carried by the moving float glass in transverse directions such that the temperatures of the glass is made more isothermal and the currents in the tin do not lead to longitudinal distortion.
In a preferred embodiment of the invention, two barriers are located in the forming region of a float glass bath and are situated very close to the surface of the tin and the bottom surface of the glass. These barriers have grooves of a cross-cut nature angled about 5° to about 30° from the direction of movement of the float glass. The barriers preferably do not extend to the bottom of the tin bath so they allow free movement of the tin beneath them.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional elevation view of an apparatus for producing flat glass in accordance with this invention.
FIG. 2 is a sectional plan view of the apparatus shown in FIG. 1.
FIG. 3 is a partial sectional elevation view of the delivery facility and upstream end of the forming chamber shown in FIG. 1 illustrating the preferred location of the tin diffuser barrier of the invention.
FIG. 4 is a partial sectional plan view of the delivery facility and upstream end of the forming chamber seen in FIG. 3 taken along the section line 4--4 of FIG. 3.
FIG. 5 is a partial sectional elevation of the tin diffuser of the invention taken along the section line 5--5 of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1 and 2 there is shown a view of a suitable apparatus for carrying out the present invention. The glass-making apparatus comprises a furnace 11, delivery means 13 and a forming chamber 15 and a glass removal facility 17. It will be understood that the lifting and conveying apparatus employed in the practice of this invention may be designed to cause the glass to be conveyed along either a horizontally extending path as shown or along an upwardly extending path.
The glassmaking furnace 11 includes a melting section (not shown) and a refiner or conditioner, the end of which is shown. The refining or conditioning section of the furnace 11 comprises a furnace bottom 19 preferably with a raised section 20, side walls 21 and a front basin wall 23. The furnace further comprises an upper front wall 25 which preferably is suspended or supported from above by a structural support 26 and a roof 28 overlying the upper portion of the furnace. A pool of molten glass 27 is maintained in the furnace.
The delivery means 13 includes a threshold 31 resting on a cooling block 33 or other support. A cast refractory seal 35 or the like is disposed between the threshold 31 and the cooling block 33. Extending through the holes in the threshold are conduits or pipes 36 for transporting coolant or the like through the interior of the threshold 31 and for controlling its temperature during use. At the ends of the threshold 31 there are side wall portions or jambs 37 on the sides of the channel through which molten glass may be delivered from the pool of molten glass 27 residing in the bottom portion of the furnace 11. The top of the delivery means 13 is defined by a roof 39. The roof is preferably a flat arch which is supported by supporting means (not shown) extending above it and connected to flat arch supporters embedded in the flat arch itself. Extending transversely across the delivery means 13 are two gates or tweels. The first tweel is a backup tweel 41 connected to a support assembly (not shown) for raising or lowering it into engagement in the pool of molten glass 27. The second tweel is a control tweel 45 supported by support assembly (not shown) for raising and lowering the tweel. The tweel is held in operating position in contact with the molten glass to be delivered for forming. The control tweel 45, along with the threshold 31 and the jambs 37, define an opening through which a layer of molten glass may be delivered for forming.
The forming chamber 15 comprises a bottom casing 51. This casing is preferably a casing constructed of metal, such as steel. The casing is preferably impervious to the molten metal in the chamber. The forming chamber 15 further comprises a top casing 53 including a top, ends and side portions. The top casing is also preferably constructed of impervious metal. An end piece or lip casing 55 is disposed across the forming chamber at its downstream end and, connected to the bottom casing 51. Disposed within the bottom casing 51 is a refractory bottom 57, preferably a refractory bottom that has been cast in place inside the bottom casing 51 between the inlet end bottom 35 and an exit lip 59 mounted or cast against the lip casing 55. Preferably embedded within the bottom refractory 57 are pipes, not shown, for temperature regulation.
The forming chamber 15 further comprises refractory side walls 61. These, along with the bottom refractory 57, the threshold 31 and the exit lip 59, define a container for holding a pool of molten metal.
The upper portion of the chamber further includes a lintel 63 at its upstream end. This lintel 63 may be used as a means for supporting delivery means roof 39. Additionally, the upper portion of the chamber includes a ceiling or roof 65 preferably constructed of refractory material suitable for radiating or absorbing heat uniformly over the area facing the glass beneath it during operation. Extending through the ceiling of the forming chamber are controllable heating elements 67 used to control the rate of heat removal from the glass during forming. These heating elements are connected to bus bars (not shown) which are connected, in turn, to a source of power (not shown). The upper portion of the forming chamber 15 includes a top casing end wall which may extend over the glass removal or withdrawal facility 17 at the downstream end of the forming chamber 15. Alternatively, a separate hood may be provided over the glass removal facility 17. Disposed within the bottom container portion of the forming chamber is a pool of molten metal 69, preferably molten tin or an alloy of tin.
At the downstream end of the forming chamber is the glass removal facility 17 for withdrawing a continuous sheet of glass from the surface of the pool of molten metal 69 and for conveying a withdrawn sheet of glass from the forming chamber 15. The glass removal facility includes curtains 71 or other barriers or seals to segregate the headspace of the forming chamber from the outside environment. These are preferably flexible curtains of heat resistant cloth (e.g., asbestos) or the like. The glass removal facility further includes liftoff rolls 73 mounted in a position to lift and convey a glass sheet from the forming chamber. These rolls 73 are provided with seals 75, usually of graphite, to seal the bottom portion of the forming chamber from the outside environment.
When making flat glass using the apparatus described, a layer of molten glass 77 is delivered onto the molten metal 69 in the upstream end of the forming chamber. This glass is cooled and forces are imparted to the glass, for example, by the action of rolls 73. This causes the glass to advance along the surface of the pool of molten metal and to form a continuous sheet of glass that is dimensionally stable (that is, it assumes a stable thickness and width that is maintained as the glass is withdrawn from the forming chamber). The applicant recognizes that the term "bath" has at times been used in the art to mean the pool of molten metal which the glass is formed and at other times to mean the forming chamber when the glass sheet formation takes place on the molten metal bath. However, in this specification, the applicant intends to refer to the structure as the forming chamber and only use the term "bath" to refer to the pool of molten metal. The terms "ribbon" and "sheet" are used interchangeably to refer to the strip of glass formed on the bath in the forming chamber. The directions "upstream" and "downstream" are defined by the direction of glass flow through the process; that is, glass flows from an upstream portion of the glassmaking apparatus toward a downstream portion of the glassmaking apparatus.
Extending across the forming chamber 15 between sidewalls 61 are illustrated two of the molten metal flow diffusers which form part of the system of the invention. The molten metal flow diffuser barriers are cross-hatched with grooves on their upper surfaces to divert the flow of the molten metal which is drawn by interfacial frictional drag of the glass as the glass advances on the tin surface. The cross-hatched grooves of the tin flow diffusers serve to direct the flow of the tin in transverse directions thereby intermingling various portions of the tin and evening the heat on the under-surface of the glass sheet as it is formed. This evening of the traverse heat distribution reduces the longitudinal defects that are caused by uneven thinning of the glass due to uneven temperature of the glass transverse to its direction of movement. The barriers, as illustrated, are preferably placed as close to the bottom surface of the glass as possible without actually contacting the glass.
The barriers are preferably located in the forming region of the chamber. The forming region is defined herein as that region where the glass is changing in width and/or thickness. The tin diffusers are thus positioned a short distance downstream from the location of molten glass delivery to the forming chamber. An optimum position for the barrier of the invention is just upstream of the point at which the glass begins to solidify because this location gives the greatest decrease in longitudinal distortion of the finished sheet glass.
The molten metal diffuser of the invention is successful in improving even thickness variations of the glass surface that are of 0.001 inch or less. Such micro-distortions contribute to distortion quality problems that arise in formation of thin sheet glass. The diffuser also successfully reduces longitudinal thickness variations of between about 0.01 inch and about 0.005 inch from nominal thickness which are important in optical quality of conventional sheet glasses.
As may be seen with reference of FIGS. 3 and 4, the tin diffuser barriers 82 of the invention are located in the upper portion of the tin bath almost in contact with the glass sheet as it moves over the molten metal. The tin diffusers are cross-hatched with grooves 83 that are skewed from the angle of movement of the glass. The grooves are skewed at an angle of between about 5° and about 30° from the direction of the glass flow. While illustrated at the hot end of the forming region, it is also within the invention to place molten metal diffuser barriers intermittently along the entire bath length. The forming region at the hot end is the primary location where centerline distortion is created. However, other points of the bath also contribute to the defect and the optical quality of the glass is improved by evening the heat traverse to the direction of travel that is accomplished by the system of the invention.
With reference to FIG. 5, the barrier generally indicated as 82 is a beam transverse of the direction of glass flow with the top grooved surface 83. The beam is preferably somewhat streamlined as at 85 in order to create less disruption by the location of the barrier in the bath where various convection currents are moving the tin. The bottom of the barrier 82 is located well above the bath bottom 57 so as to allow free movement of the molten metal beneath the beam tin diffuser. The beam may be mounted in place by being placed onto refractory blocks that are set at the margins of the molten metal bath. The blocks may be notched to accept the barrier and it may further be held by another refractory block on the top of the beam.
The tin diffuser beam or barrier may be formed of any material that has the ability to withstand the temperatures of the molten metal bath and not be attacked by the molten metal. Further, the material must be workable so as to allow the formation of the small grooves in its upper surface. Among suitable materials for the barriers are refractories, graphite, refractory coated metals, and metals such as stainless steel. A preferred material is tungsten as it is stable in the bath conditions and relatively easily workable.
The grooves on the upper surface of the barrier may be any frequency and depth which achieves the desired reduction or elimination of longitudinal distortion. The grooves generally are located about 1/4 inch apart and may be between about 1/16 and about 1/8 inch deep. The width of the beam may be any width which achieves the desired advantage of the invention. A preferred width is greater than about 2 inches for effective diffusion of the molten metal held by interfacial drag to the bottom of the glass.
While the number of barriers for the preferred embodiment illustrated in the drawings is two, the invention also comprehends the utilization of one barrier or a series of barriers located at other portions of the forming chamber than the hot end or barriers located intermittently the entire length of the chamber. The barriers, no matter where located, will serve to diffuse the molten metal which is carried beneath the surface of the glass and even the temperature differences in the traverse direction of the glass as it moves through the metal bath.
The tin diffuser of the invention may be located at any distance below the bottom of the glass moving over the metal bath that gives the desired elimination or reduction in centerline distortion. The barrier should be as close as possible without risking touching the glass. A preferred depth has been found to be between about 4 and about 6 millimeters for the greatest decrease in longitudinal distortion. However, greater depth may be utilized to achieve some of the desired effects without any risk of touching of the glass caused by variation in the height of the molten metal in the bath. However, the greater depth location does not as effectively diffuse the molten metal that is carried very close to the glass by interfacial drag.
While the invention has been described with the preferred metal diffusion barrier being a beam which allows free movement of tin beneath the beam, the invention also comprehends the utilization of the invention in other types of barriers. Specifically, it is within the invention to groove floating barriers such that as the glass passes over them the molten metal which is being carried by interfacial drag of the moving glass is diffused. Further, it is also possible with the molten metal diffusion system of the invention to groove the tops of dams within the bath to make possible the lateral diffusion of metal as it is carried by frictional drag through the bath by the movement of the glass.
Although this invention has been described with reference to particular embodiments of it which are illustrated here, those skilled in the art of glassmaking will appreciate that the specific embodiments described may be modified without departing from the scope of the invention. For instance, the grooves of the tin diffuser could be shaped other than rectangularly. The grooves could be rounded at the bottom or key-hole shaped without departing from the scope of spirit of this invention. Further, the system of the instant invention could be utilized with other float glass forming processes such as that of Pilkington as illustrated in U.S. Pat. No. 3,220,816 in which glass leaving the furnace is dropped to form a pool in the molten metal from which the float glass is drawn.
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A method and apparatus for reducing longitudinal distortion in float glass is disclosed. A beam or barrier having cross-hatched grooves is installed below the advancing float glass ribbon in a float glass-forming chamber. The barrier acts to divert or diffuse laterally the molten metal which is being drawn by interfacial drag with the bottom surface of the glass. The diffusion evens the heat on the undersurface of the glass and reduces glass distortion.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to improvements in vent apparatus for protecting a confined space having a vent aperture for relief of an overpressure condition. Conventional vent apparatus is especially useful for covering relief openings in enclosures subject to rapid pressure build-ups such as may occur during explosions or uncontrolled combustion events in bag houses, duct work communicating with the bag houses, processing equipment, duct work leading to and from the processing equipment, buildings, pressure vessels, and other types of commercial and industrial installations where explosions or uncontrolled combustion events producing high overpressures may occur.
Vents of the type described have a vent unit including a vent portion that completely opens when a predetermined overpressure condition, such as an explosion or an uncontrolled fire, occurs in the protected area, thereby relieving the excessive overpressure and preventing untoward damage to equipment, vessels, duct work, building structures, and the like that would otherwise be subjected to potentially catastrophic overpressure events.
More particularly, the invention concerns high overpressure vent structure having a pressure relief portion that is in closing relationship to the vent aperture of the protected area, and that includes recloser structure for at least generally closing off the vent aperture in the event of opening of the pressure of the vent unit under a preselected overpressure condition. The recloser structure includes a spring steel vent aperture recloser panel that is normally maintained in a location out of closing relationship to the vent aperture, but may move into a position closing the vent aperture following opening of the pressure relief portion of the vent unit as a function of its inherent resilience of the spring steel.
Advantages of reclosing of the vent aperture by the recloser structure after opening of the primary vent unit include:
elimination or reduction of the ingress of air and thereby oxygen, thus mitigating the effects of a secondary explosion if the protected area remained exposed to the surrounding atmosphere via the vent opening; prevention of continuation of combustion of process materials that could cause permanent damage to the protected installation; improvement of suppression of flames/fire, where inert gas, water mist, or the like, is used as an extinguishment agent, by virtue of the fact that the resulting combustion gases/flames cannot escape through venting holes; and reduction/elimination of contamination of the protected process zone.
Releasable mechanism is provided in engagement with the panel normally maintaining the panel in the bent condition thereof, out of the location closing the vent aperture. An actuator is connected to the releasable mechanism for effecting release of the panel upon from command from a sensor unit that senses opening of the vent unit from an overpressure condition.
2. Description of the Prior Art
Explosion vents traditionally have been provided with arupturable sheet of metal that has score lines or interrupted slits that define a line of weakness presenting the relief area of the vent. The amount of overpressure required to open the relief area of the vent is determined by, among other things, the type, thickness, and physical properties of the metal selected for fabrication of the explosion vent, the shape and nature of the line of weakness, the location of the line of weakness in the overall area of the vent, and oftentimes the provision of a series of spaced cross-tabs overlying the line of weakness in predetermined relative dispositions.
An exemplary explosion vent of this type is shown and described in U.S. Pat. No. 6,070,365, wherein a rectangular pressure relief panel is mounted in a frame adapted to be secured across a pressure relief opening. The unitary relief panel is formed from a single sheet of steel, stainless steel, Inconel, or other similar metal, and has a three-sided line of weakness defined by a plurality of interrupted slits. The series of spaced rupture tabs positioned over the line of weakness as shown in the '365 patent, must rupture before the relief area of the panel gives away under a predetermined high overpressure resulting from an explosion or a fast-burning fire.
U.S. Pat. No. 5,036,632 is another example of a conventional rectangular metal sheet explosion vent that has a three-sided line of weakness defined by interrupted slits. A layer of synthetic resin material or the like may be provided in covering relationship to the line of weakness slits. Rupturable tabs are also provided in the type of vent shown and described in the '632 patent that must break before the central section of the panel ruptures along the slit line to relieve an overpressure. An elastomeric sealing gasket or gaskets may be provided around the periphery of the rupturable metal sheet.
U.S. Pat. No. 4,498,261, referred to in the disclosure of the '632 patent, is a rectangular vent panel that opens under a relatively low pressure in which the thin sheet structure is described as being medium impact polystyrene, a relatively soft metal such as aluminum alloy, or a fully annealed stainless steel. Interrupted X-pattern slits extend through the vent panel and define individual lines of weakness that terminate at the apex of the X. A thin sealing membrane having the same area as the rupture panel is adhesively bonded to the rupture panel, and may be formed of polyethylene, stainless steel, or aluminum. Similar structure is shown and described in U.S. Pat. No. 4,612,739.
Although prior art pressure relief vents of the type described do satisfactorily open and relieve predetermined overpressure condition in protected spaces, these vents have remained open, thereby allowing the confined space to have continuing access to the surrounding atmosphere. Following out rush of products of combustion from the explosion or fire and relief of the high pressure, oxygen from the atmosphere is immediately available through the vent aperture that can produce a secondary explosion, exacerbation of a fire, or re-ignition of the fire.
SUMMARY OF THE INVENTION
It is conventional to provide apparatus for protecting a confined space having a vent aperture for relief of an overpressure condition. Apparatus of this type includes a vent unit having a pressure relief portion across the vent aperture in closing relationship thereto. The pressure relief portion of the vent unit opens when subjected to a preselected overpressure in the protected space.
This invention improves conventional vent apparatus for relieving high overpressure conditions by the provision of recloser structure for at least generally closing off the vent aperture in the event of opening of the pressure relief portion of the vent unit under a preselected overpressure condition. The reclosure structure includes a resilient flexible spring steel panel that in its normal state is of a configuration and in a position to at least substantially close the vent aperture. The spring steel panel is bent away from and disposed in a location out of a position substantially closing the vent aperture. Releasable mechanism engages the panel for normally maintaining the panel in the location thereof out of closing relationship to the vent aperture. An actuator is connected to the releasable mechanism for actuating the mechanism to release the panel for movement as a function of its inherent resilience from said location to said position thereof substantially closing the vent aperture after the relief portion of the vent unit has opened as a result of said preselected overpressure in the protected area.
A sensor is preferably provided in association with the vent unit of the vent apparatus that is operable to sense opening of the pressure relief portion of the vent unit resulting from an untoward high overpressure condition such as an explosion or products of combustion from a fast-burning fire. The sensor is operably connected to the actuator for effecting operation thereof to release the panel for return to a position closing the vent aperture when the sensor detects opening of the pressure relief portion of the vent unit. Operation of the actuator in response to a signal from the sensor may be controlled so that the spring steel panel normally held in a position away from the vent aperture is released for swinging movement into closing relationship to the vent aperture only after a predetermined variable time delay.
In a preferred embodiment, cable structure may be connected to the flexible spring steel panel for maintaining the latter out of closing relationship to the vent aperture of the protected structure, with actuating mechanism being provided in association with the cable structure for releasing the cable upon command, thereby allowing the flexible spring steel panel to swing back into a position substantially closing the vent aperture of the protected area.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of vent apparatus having a vent unit provided with a pressure relief portion normally closing a vent aperture of protected structure, wherein the apparatus includes vent aperture recloser structure having a flexible spring steel panel bent away from the vent aperture and held in its normally open position by selectively releasable mechanism, that includes a cable-severing guillotine device forming a part of the releasable mechanism;
FIG. 2 is an essentially schematic side elevational view of the vent apparatus of FIG. 1 , showing the flexible spring steel recloser panel in its restrained bent position;
FIG. 3 is a schematic side elevational view of the vent apparatus of FIGS. 1 and 2 showing the spring steel panel in its vent aperture closing position after opening of the vent unit under a predetermined overpressure;
FIG. 4 is a fragmentary enlarged view of one of the panel-restraining members that is connected to the selectively releasable mechanism;
FIG. 5 is an enlarged fragmentary view of a portion of the flexible spring steel panel illustrating the manner in which the panel is mounted on the vent unit of the vent apparatus;
FIG. 6 is an enlarged, essentially schematic, cross-sectional view of a portion of a retaining cable for the flexible spring steel panel, and a solenoid device for selective release of the cable, and thereby the panel, upon command;
FIG. 7 is a fragmentary, enlarged, horizontal cross-sectional view of the cable restraining and release mechanism as shown in FIG. 6 , and
FIG. 8 is a perspective view of an alternate vent apparatus having a circular configuration.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The vent apparatus 10 of this invention, illustrated in FIGS. 1 and 2 , is adapted to be mounted in normal closing relationship to the vent aperture of structure presenting an area requiring protection from an untoward overpressure event.
A rectangular metal frame element 12 may, for example, be mounted on and secured to the protected area structure in surrounding relationship to a vent aperture of the structure. Frame element 12 may typically have a box-defining leg segments 14 that are secured to the protected area structure in surrounding aligned relationship to the vent aperture of the structure, while the flange segments 16 of frame element 12 are unitary with and project outwardly from the extremities of leg segments 14 remote from the protected area structure. It is to be understood in this respect that the frame element 12 is exemplary only, and a number different components may be provided for securing vent apparatus 10 on structure to be protected in alignment with a respective vent aperture therefor.
A rectangular vent unit hold-down member 18 may be provided in overlying relationship to the flange segments 16 of frame element 12 . A series of threaded studs 20 secured to the outer face of flange segments 16 and that extend through respective openings therefor in flange segments 16 , are provided, with associated hold-down nuts 22 .
A conventional, composite, laminated vent unit 24 is trapped between flange segments 16 and hold-down member 18 and has outer dimensions approximately equal to the peripheral dimensions of flange segments 16 and hold-down member 18 . Vent unit 24 , as shown in FIG. 5 , may, for example, include a pair of vent panels 26 and 28 of stainless steel, Inconel, titanium, nickel, or Hastelloy, or similar metals, separated by an intermediate cover sheet 30 of, for example, fluorinated ethylene propylene (FEP), or alternatively, polytetrafluoroethylene (PTFE), or perfluoroalkoxy polymer (PFA). Suitable stainless steel stock may include types 301, 304, 316, 316L, and 316LT. The vent panels 26 and 28 typically have a series of spaced, end-to-end slits defining a substantially U-shaped line of weakness 32 presenting a pressure relief portion 34 of each vent panel 26 and 28 . The terminal ends of each line of weakness 32 remote from the bight portion thereof, present respective hinge areas for the pressure relief portions 34 . The sheet 30 serves to cover and close the slits defining the lines of weakness 32 in vent panels 26 and 28 .
In preferred embodiments of vent apparatus 10 , as is well known to those skilled in the explosion vent panel art, vent panels 26 and 28 may be fabricated from metal stock of varying type, thickness, and physical properties, and the spacing between the slits making up lines of weakness 32 adjusted to assure opening of the pressure relief portion 34 of vent panels 26 and 28 by severing of the space between adjacent slits when the pressure buildup within the protected area reaches a predetermined overpressure value. Exemplary vent panels 26 and 28 may be fabricated of a selected metal, with a preferred material being 1.4301 stainless steel having a thickness of from about 0.2 mm to about 0.6 mm and preferably about 0.4 mm. The sheet 30 may, for example, be of a thickness of about 0.250 mm and preferably is from about 0.0125 mm to about 0.30 mm.
Vent aperture recloser structure 36 preferably comprises a recloser panel 38 fabricated from hard rolled type 1.4310 stainless spring steel having a thickness of from about 0.6 mm to about 1.2 mm and most preferably about 0.8 mm. The difference between the yield point and the tensile strength of the recloser panel is no more than about 30%. Preferably, the yield point and tensile strength of the recloser panel are at least about 1200 N/mm 2 and about 1450 N/mm 2 , respectively. Exemplary spring steel materials useful in fabrication of vent unit 62 of vent apparatus 30 are available from Precision Metals M.V. B-2800 Mechelen, BE, including stainless steel austenitic 1.4310 C1300-hard rolled EN10088-2 having a tensile strength of 1404-1463 N/mm, a hardness of 431-446 HV, and an elongation (A80 mm %) 11.5-16.5; EN10151 AMS 5519 having a tensile strength of 1440-1460 N/mm 2 , a hardness of 465-468 HV, and an elongation (A80 mm %) 13-16; and EN 10151 types having (a) a tensile strength of 1325 N/mm 2 , a hardness of 403 HV, and an elongation (A80 mm %) A50:9; (b) a tensile strength of 1412-1428 N/mm 2 , a hardness of 429-431 HV, and an elongation (A80 mm %) 1.2; ©) a tensile strength of 1397 N/mm 2 , a hardness of 423 HV, and an elongation (A80 mm %) A50:4; (d) a tensile strength of 1410-1414 N/mm 2 , a hardness of 400-402 HV, and an elongation (A80 mm %) 1.4; and (e) a tensile strength of 1380-1382 N/mm 2 , a hardness of 441 HV, and an elongation (A80 mm %) 16-18.
An end marginal section 38 a of recloser panel 38 is trapped between components comprising flange segment 16 a of frame element 12 and leg portion 18 a of hold-down member 18 . The studs 20 secured to flange segment 16 a and nuts 22 thereon, serve to firmly affix marginal section 38 a of recloser panel 38 to frame element 12 and hold-down member 18 . It is to be observed from FIG. 2 that the remaining section 38 b of recloser panel 38 is bent in a direction away from vent unit 24 and is of continuously curved configuration. The segment 38 b ′ of curved section 38 b adjacent marginal section 38 a of recloser panel is of greater curvature than the remaining segment 38 b ″ of section 38 b.
Releasable mechanism 39 is provided in engagement with the recloser panel 38 for normally maintaining the latter in its bent configuration as shown in FIG. 2 out of closing relationship to the vent aperture. Mechanism 39 includes an elongated bar 40 is affixed to the outer face of segment 38 b ″ of section 38 b of recloser panel 38 , opposite vent unit 34 , and preferably extends substantially the full width of recloser panel 38 . Bar 40 is provided with two widely-spaced openings 42 adjacent opposite ends thereof that receive respective members in the form of externally threaded studs 44 a and 44 b that are welded to the rear face of section 38 b of recloser panel 38 . Each of the studs 44 a and 44 b extends beyond the outer face of bar 40 . A washer 46 is provided on each stud 44 a and 44 b adjacent bar 40 . A nut 48 is threaded onto each stud 44 a and 44 b adjacent washer 46 . Retainer structure 49 includes an elongated cable 50 , forming apart of the releasable mechanism 39 . One end of cable 50 is turned upon itself to form a loop 50 a that is trapped between washers 52 and 54 on stud 44 a . An outer nut 56 engages the washer 54 on stud 44 a and snugs washers 52 and 54 against end loop 50 a of cable 50 . Similarly, a cable section 58 of retainer structure 49 has a loop turned upon itself that is trapped between nuts and washers on stud 44 b in a manner similar to the entrapment of cable loop 50 a on stud 44 a . The end of cable section 58 remote from stud 44 b is connected to an intermediate portion of cable 50 by cable clamp 60 .
It can be seen from FIG. 1 , for example, that the stretch 50 b of cable 50 and cable section 58 , joined by cable clamp 60 , in association with bar 40 , form a generally triangular relationship of the components such that the restraining force on the outermost end of recloser panel 38 is substantially equalized thereby precluding canting of the recloser panel 38 .
The outermost free end of section 50 c of cable 50 is re-bent upon itself and looped about a capstan 62 . Cable clamp 64 secures adjacent portions of cable section 50 c . A device 66 is provided for severing section 50 c of cable 50 upon command. Device 66 may include a guillotine unit 68 having opposed blades that cooperate to sever cable section 50 c at a point between clamp 60 and clamp 64 .
A sensor 70 of conventional construction is preferably provided in association with frame element 12 . Sensor 70 is operable to sense opening of the pressure relief portions 34 of vent panels 26 and 28 under a predetermined overpressure. Sensor 70 may be of the optical, magnetic, or severed wire type. An electrical signal is generated by sensor 70 upon opening of the pressure relief portions 34 of vent panels 26 and 28 that controls operation of device 66 to effect cutting of cable section 50 c . When the cable section 50 c is severed, the inherent resiliency of recloser panel 38 causes the panel to move into the position shown in FIG. 3 , where the outermost extremity of recloser panel 38 engages an inwardly-directed plate member 72 secured to the innermost surface of leg segment 14 opposite marginal section 38 a of recloser panel 38 , thereby substantially closing the vent aperture. The vent panels 26 and 28 along with cover 30 are returned to their positions within frame element 12 , although normally in substantially deformed position, as schematically shown in FIG. 3 , as a result of the violent forces imposed on the vent unit 24 during relief of an overpressure condition in the protected area.
Vent apparatus 10 may be programed such that the device 66 is not activated to sever cable 50 and thereby effect closing of the vent aperture by recloser panel 36 for a predetermined time interval following sensing of opening of pressure relief portions 34 by a predetermined overpressure condition. For example, in some installations of vent apparatus 10 , release of the recloser structure 36 and pivoting thereof into closing relationship to the vent aperture of the protected structure, may not occur for as long as five seconds, or an even longer time period if desired by a particular customer.
In the alternate embodiment of the invention illustrated in FIGS. 6 and 7 an electro-mechanical device 166 is used as a replacement for device 66 . In this instance., the outer segment of section 150 d of cable 150 is looped around a spring-biased, normally open armature 174 of solenoid 176 . When armature 174 is retracted against the force of spring 178 upon receiving an electrical command signal from sensor 70 , the loop 150 d of cable section 150 c is released from the armature 174 , thereby allowing recloser panel 38 to close as previously described.
The alternate vent apparatus 110 of the invention shown in FIG. 8 differs from vent apparatus 10 only in that the frame element 112 , vent unit 124 , and recloser panel 138 are all of circular configuration rather than being rectangular, as in the other embodiments of the invention. Operation of vent apparatus 110 is essentially the same as the invention of FIGS. 1-7 in that cable section 150 , connected to recloser panel 138 , is severed by guillotine mechanism or released by a solenoid, similar to solenoid 166 , upon command from a sensor such as sensor 70 . However, in view of the somewhat narrower marginal section 138 a of recloser panel 138 of apparatus 110 , somewhat thicker spring steel material may be necessary to assure full closure of recloser panel 138 upon release thereof from its normally restrained position, as shown in FIG. 7 .
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Apparatus for protecting a confined space having a vent aperture for relief of an overpressure condition and provided with a vent unit having a pressure relief portion normally closing the vent aperture is provided with recloser structure for generally closing off the vent aperture in the event of opening of the pressure relief portion of the vent unit. The recloser structure includes a resilient, flexible, spring steel recloser panel that is normally held in a bent condition out of closing relationship to the vent aperture. Releasable mechanism engages the recloser panel for normally retaining the panel in its open position. An actuator is connected to the releasable mechanism for actuating the latter to release the recloser panel for movement as a function of its inherent resilience into substantially closing relationship to the vent aperture after the relief portion of the vent unit has opened. The vent apparatus including the spring steel recloser panel may be of either rectangular or circular configuration.
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FIELD OF THE INVENTION
This invention relates to the accelerated evaporation of water or other solvent from a coating on the surface of a panel, and is particularly useful for accelerating the drying of intermediate and final coats of water borne coatings for example during the re-painting of road vehicles. It also concerns a booth or other enclosure for the painting or re-painting or coating of motor vehicles and the like.
DESCRIPTION OF THE PRIOR ART
Before the advent of water-borne vehicle paints in the 1970's, all paint for vehicles was solvent-based, and was applied as a primer, then a base coat and then a top coat. The solvent generally evaporated rapidly between coats without the need for excess temperature.
Paints conventionally used in decorating motor vehicles are solvent-borne and are formulated to be applied by spraying. A spray paint is designed to have low viscosity at its point of atomisation, so that it atomises easily and to have high viscosity at the target, for example the vehicle body or body panel to prevent sagging. In solvent-borne paints this viscosity change is achieved by evaporation of solvent while the paint spray is in flight between the spray gun and the target.
When water-borne paints were first introduced into the motor industry in the early 1970's, they were designed to function on spraying in the same way as their solvent based counterparts, that is to change viscosity in flight through solvent (in this case water) evaporation between the gun and the target. However, as compared with the organic liquids employed as carrier vehicles in solvent-borne paints, water has certain unique properties. First, unlike organic solvents it is present in the atmosphere and variations in its partial pressure (that is its relative ambient humidity) alter from day to day the rate at which it will evaporate. Second, its latent heat of vaporisation is high and therefore more energy is required per unit mass to evaporate water as compared with organic solvent. In consequence, these first introduced water-borne paints had to be sprayed in carefully controlled air-conditioned environments. They were never really technically satisfactory and this led to them having to be withdrawn. The first truly effective water-borne painting system for motor vehicles is that described in EP-B-38127 and comprises a water-borne base coat-clear coat system.
Base coat clear coat systems were again introduced into the motor industry in the early 1970's in order to improve the appearance of the top coat or outer-most coat on the finished vehicle, especially for metallic effect paints. The top coat is responsible for the gloss and colour of the vehicle as well as for protecting the vehicle against weathering, scratches, stone chipping and related damage to its surface. In a conventional one-coat top coat the top coat paint has to provide all these features. A base coat-clear coat system consists of two different paints. The base coat, which is applied first is highly pigmented and provides the colour and appearance (especially the metallic effect) only, whereas the gloss and stability to weathering abrasion and stone chipping comes from the clear coat.
EP-B-38127 referred to above relies on a water-borne base coat and it overcomes the problem of the viscosity change required in a spray paint in a revolutionary way. The paints are formulated so as to be thixotropic or pseudoplastic and so relatively little or no evaporation of water is required in flight to ensure the high quality spray performance called for in car painting.
The consequence of this is that the paint film can sometimes contain relatively large levels of water. When the painting step is taking place during vehicle production, this presents little or no difficulty. The base coat resin system is sufficiently robust to allow wet-on-wet application of clear coat, that is the clear coat can be applied over the base coat after the base coat has been given very little time to dry. The whole of the top coat film is subsequently baked at a high-temperature which drives off any water and cures the film.
In motor vehicle re-spray, the position is a little different. A re-sprayed vehicle cannot be subjected to baking at the temperatures used on a vehicle production line. Damage would be caused to temperature sensitive and meltable components. Hence it is desirable to be able to remove rather more water from the base coat.
Many techniques have been devised for drying and baking motor vehicles painted with solvent-borne paint. Superficially many of these techniques might seem to be directly applicable to the drying of water-borne paints after mere routine modification. However, such is the difference in behaviour as between water-borne paints and solvent-borne paints that the outcome of apparently minor modifications on the behaviour of a water-borne system is often not at all clear. With solvent-based paints, the problem of removing solvent from painted vehicles has been addressed primarily by proposing a substantial bulk air flow through the booth containing the vehicle. For example in U.S. Pat. No. 1,606,442 (1926), a solvent-based coating is dried in an air-warmed and specially humidified booth. The coating is then hardened by cooling in a bulk air-flow.
Blowing air at water-based coatings tends to cause the formation of a skin on the outer surface which then severely limits proper loss of water from within the film. This has adverse consequences on the appearance of film, since shrinkage of the film can be uneven and flake control in metallic or mica flake containing films deteriorates.
A further disadvantage of air-blowing systems has been the disturbance of dust from adjacent surfaces, which contaminates the coating.
It is of course known, e.g. from FR-A-2029314, to heat a car chassis to a high temperature such as 200° C. during the manufacturing process, in a hot-air blown kiln, to cure a base coating, and indeed infra-red radiative heating has been proposed for accelerating secondary coatings preparatory to a top coating. Heating in this way is not only expensive for a motor vehicle re-spray process but also of course, impractical when considering drying an assembled vehicle. There is therefore a demand for a method of accelerating the drying of such a coating, or indeed of any other coating on a panel, which is energy efficient and which reduces the "flash off" time to acceptable levels, without increasing the risk of dust contamination inherent with the application of non-aqueous solvent-based coatings.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides a method of forcing evaporation of a solvent such as water from a coating on a predefined surface of a panel by directing a jet of air from an air supply held at a predetermined distance from the panel towards one edge region of the panel, the jet being substantially narrower, when it reaches the panel edge region, than the length of the panel edge and the jet being inclined to the plane of the panel such that the air from the jet is entrained by the panel in a spreading, predominantly laminar flow across the panel surface over that edge region and from that edge region to all the other edges thereof, thereby inducing such laminar flow over substantially the whole surface and replacing vapor-laden air closely adjacent the surface with fresh air to accelerate drying. The use of an essentially local air supply allows the position and direction of the air jet to be controlled so as to optimise the drying effect of the air, and so as to avoid disturbing any dust which may be present on adjacent surfaces. While the flow velocity of the air jet may be 1 to 2 ms -1 as it reaches and travels along the panel surface, there is no need to increase the usual flow rate of drying air which may be moving in bulk elsewhere, e.g. from ceiling to floor in a booth. This also avoids dust disturbance.
We have found that this method is particularly energy-efficient, and that it is surprisingly effective in drying panels such as vehicle doors and bonnets.
The invention could also be beneficial in forced evaporation from thick films such as the thick water-borne primer coatings already mentioned, provided that the trapping of water or other solvent can be overcome.
Acceleration of evaporation can be further improved, in situations where the minimising of energy consumption is not so critical, by the application of thermal energy, either by pre-heating the air which is to form the jet of air, or by using radiative heat sources such as IR panels directed at the surface of the panel to be dried.
The invention also provides a booth or other enclosure for the painting or re-painting of panelled articles such as motor vehicles, having an air inlet and an air outlet for the bulk movement of drying air over a painted article standing in the booth; and characterised by at least one supplier of air at a flow velocity substantially greater than that of the bulk movement, means for holding the supplier a predetermined position and orientation, in use, in relation to a panel of the painted article which is to be dried, such as to direct a jet of drying air towards one edge region of the panel, the air supplier being so shaped, and the flow velocity being such, that the jet is substantially narrower, when it reaches the panel edge region, than the length of the panel edge, and the air supplier being positioned such that the jet is inclined to the plane of the panel and the air from the jet is entrained by the panel in a spreading, predominantly laminar flow across the panel surface over that edge region and from that edge region to all the other edges thereof, thereby inducing such laminar flow over substantially the whole surface and replacing vapor-laden air closely adjacent the surface with fresh air to accelerate evaporation.
The preferred form of air supplier is of the "air mover" type, i.e. one which is arranged to entrain a portion of the bulk flow of air from the enclosure's inlet so as to increase the volumetric rate of flow; thus the air supplier combines the pressurised air with the bulk air flow to generate a directional outflow at the greater flow velocity.
Conveniently, the air supply is positioned at the correct predetermined distance and inclination by adjusting a supporting frame.
In order that the invention may be better understood, two embodiments will now be described, by way of example only, with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the interior of a re-painting booth embodying the invention, with a vehicle whose panels are to be dried;
FIG. 2 is a schematic vertical section taken transversely of the car in the booth of FIG. 1;
FIG. 3 is a side view of part of a vehicle in a re-painting booth, showing part of the apparatus for drying panel coatings using a second embodiment of the invention;
FIG. 4 is a partial plan view of the arrangement shown in FIG. 1;
FIG. 5 is a perspective view of a support frame including two air outlets in accordance with the second embodiment of the present invention; and
FIG. 6 is a partial perspective view of an alternative support frame together with a support rail, for use with the method of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In these examples, a thin water borne base coating on a vehicle panel is dried using a relatively fast moving air stream adjacent to the coated panel. This disturbs the air close to the panel which contains high moisture levels and continually replaces it with drier air. The air temperature may be higher than that of the surrounding air, or the system may be used in conjunction with infrared heating, so as to replace the latent heat of evaporation.
A preferred example of drying apparatus embodying the invention is shown in FIGS. 1 and 2. A re-painting booth 1 is of conventional design with a filtered air inlet 3 in the ceiling and a grid 4 in the central region of the floor for extracting moisture-laden air. A car 2, with panels which will have been coated with paint sprayed in the booth 1, stands over the grid 4. There is a bulk flow of air generally downwards, as shown by arrows in FIG. 2, typically at 0.5 ms -1 . A pressurised air supply 9 of conventional construction has an outlet for paint-spraying (not shown).
Twelve air suppliers in the form of cylindrical air movers 7 (available commercially) are positioned adjustably, in four "zones" of three, just below the bulk air inlet 3 and within its periphery, at least 0.5 m from the outer edges of the filters. Each air mover 7 is of known construction, having an annular strip outlet, on the axis of the cylinder, for air supplied under pressure. The strip outlet is shaped such that the air is entrained along an inner wall of a hollow body of generally cylindrical shape, so that the air is made to flow axially in an annulus. This flow drags or entrains slower-moving bulk air in a cylinder from a low pressure inlet region, so as to generate a cylindrical outward flow generally along the axis. The flow is at a substantially greater velocity than the 0.5 ms -1 velocity of the bulk flow, such that when it reaches a target panel on the car 2, after a slight divergence and slowing, it will have a velocity of between 1 and 2 ms -1 , as measured parallel to the panel surface and 0.5 to 1 cm from the surface.
The air movers 7 are fixed to two supply pipes 5 arranged parallel to one another lengthwise of the car 2 and grid 4. Each supply pipe 5 is supported for rotation about its axis by three spaced angle brackets 6 secured to the inlet 3. On each supply pipe 5, the six air movers are mutually parallel (although an air mover at each end can be inclined inwardly, to assist drying of end panels), grouped into two zones of three, on corresponding halves of the pipe. A manual lever 8 connected to the pipe 5 allows the air movers 7 to be angled appropriately. An air line 92,93,94,95 leads from an air supply control box 91 to each zone of three air movers 7 by way of a channel within the supply pipe 5.
The air supply control box 91 includes a pressure gauge and a valve for each zone. Usually, only one zone is used at any time, and the pressure is limited to 2 bar (30 p.s.i.) to give a flow rate of 425 liters (15 cubic feet) per minute. A flow restrictor is preferably provided, upstream of the valves, so that even if all four zones are active, the flow rate does not exceed 850 liters (30 cubic feet) per minute. These requirements are entirely compatible with conventional air supplies for painting booths, e.g. for two spray guns and airfed masks. The air flow from each air mover proceeds downwardly, substantially independently of its neighbouring air movers, to reach the edge of the panel, or panel portion, to which it is directed. When it reaches the panel edge its width is still substantially less than, for example 10-20% the length of that edge of the panel. If the panel is a typical car panel and is say 2 m below the air mover, the jet will typically have diverged to a width of about 10-20 cm as it impinges upon the panel. As it reaches the panel it is deflected by the panel, but is then "attached" by the panel surface and made to flow in a generally laminar curtain parallel to the panel, spreading out, along the panel edge and from that edge to other edges so as to reach the entire periphery of the panel. The phenomenon of attachment is believed to result in part from the Coanda effect. The laminar flow originating from the air mover will also tend to entrain more air from the bulk air flow reaching the panel. Examples of this air flow are shown schematically in FIG. 2.
With the benefit of air extraction from beneath the car 2, drying air is drawn around the panels facing partly or wholly downwards, so these panels can also be dried using the principles of the invention.
The air movers must be positioned and angled carefully to obtain fully the benefits described; this is explained in greater detail below.
While the booth is described as a painting booth, it should be appreciated that the booth could be used solely for drying, if required.
We have found that power consumption for the air movers is 1.8-3.6 kW for one zone, 3.0-4.8 kW for two zones, and less than 6 kW for all four zones.
The air movers need not be cylindrical, and in the example which follows they are flat having an alongate outlet. The principle of causing a laminar, divergent flow over the panel is, however, the same. Moreover, this type of air mover is also available commercially.
As shown in FIGS. 3 and 4, a motor vehicle whose panels have been sprayed with a water borne coating is resting on the floor of a booth. The booth is ventilated in a conventional manner, with moisture laden air being extracted from the floor region.
Pressurised air is delivered in a fan-shaped, narrow jet 11, from an air outlet 10 at each appropriate position, or from the same air outlet which is moved from position to position. The or each outlet 10 is supported adjustably on a support frame, of which examples are shown in FIGS. 5 and 6 and are described in greater detail below.
The air outlet 10, known already as a "strip air mover", produces a broad, flat band of air 11, diverging only slightly, which is directed as a jet to a portion of one edge region of the panel. Thus one air outlet is disposed adjacent the front hinge of the door panel 20 so as to distribute air over the generally rectangular major portion of the door panel. Another position for the air outlet, as shown, in order to distribute air over half of the bonnet 21, is a short distance above and to the front of the headlight. In both examples, the angle of inclination of the principal axis of the air jet 11 relative to the plane of the panel is approximately 45°, and within the range 20°-80° in any event. We have found that for more elongate panels, the outlet 10 should be inclined at a shallow angle, such as 20°-30°, to the plane of the panel, and arranged to direct the air at the shorter dimension, i.e. the width of the panel, so that the air has sufficient forward velocity parallel to the panel surface to reach the far edge of the surface.
The distance of the air outlet 10 from the nearest part of the panel surface should be about 50 cm to 60 cm or about 2 feet: any nearer, and the smooth flow is disturbed with the result that the jet fails to reach the far edges of the panel with a smooth laminar flow. Any further than this from the panel and the jet (in this particular example) would expand dimensionally and volumetrically too far to enable it still to achieve the desired result.
We have found that with careful positioning of the air outlet in relation to the panel it is possible to cause the air jet to become entrained by the panel surface and to spread over the surface with a laminar flow across the panel surface. Surprisingly, the flow of air is still substantial and reasonably uniform even at the far corners of the panel. Whilst there is no adverse effect on the quality of the coating if some portions of the panel are dried more quickly than others, the energy efficiency of the system is clearly optimised by the present arrangement which delivers a steady flow surprisingly uniformly over the panel.
The degree to which the drying process can be accelerated in this way depends to some extent on the humidity of the atmosphere. A typical period for unassisted drying, i.e. a typical flash-off time for one coat, is 10 to 30 minutes. With the air jet this can be reduced to about 5 minutes. This can if necessary be reduced further to about 1 or 2 minutes with the use of heat energy, typically using 3 kW to 6 kW power for each air outlet.
Thermal energy may be applied by preheating the air from a compressor, in a conventional manner. Alternatively, or in addition, thermal energy may be applied by radiation for example from one or more IR heating panels 13 (FIG. 3).
In this example, the air is supplied under pressure of 2 bar (30 psi) from a compressor. This input pressure is restricted to 2 bar (30 psi) by a pressure limiter, and the minimum height of the air outlet is kept to 60 cm from the floor of the booth, in order to minimise the problem of dust disturbance. Clearly, the jets should never be directed towards any surface which may collect dust.
In this example, the dimension of the air outlet is 7.5 cm long by approximately 100-125 microns wide; the air consumption rate is approximately 425 liters per minute or 15 cfm (cubic feet per minute) at 2 bar (30 psi); the velocity of air as it moves over the panel surface is between 1 and 2 meters per second and the area of coverage of the panel is approximately half a square meter.
The support frame shown in FIG. 5 consists of a wheeled trolley 40 on which is pivoted a horizontal support arm 41, pivotal as shown by arrow 33. The support arm 41 is joined to two horizontal extensions 12 to form a T structure. The arm extensions 12 are pivotable about a horizontal axis as shown by arrow 34. Each arm extension 12 is linked telescopically, as shown by arrows 32, to a further extension piece connected to an air outlet 10. The connection to the air outlet 10 also allows for pivotal adjustment, as shown by arrows 30, about a horizontal axis; each air outlet 10 is also pivotable about the axis of the support arms 12, as shown by arrows 31.
An alternative arrangement for the support frame is shown in FIG. 6. A single high level aluminium rail 50, approximately 20 cm by 5 cm in section, for example mounted on the wall of the booth, supports a sliding bracket 60, for horizontal sliding motion as shown by arrow 51. A support arm 61 is mounted by means of a universal joint on the arm 60, allowing pivotal movement about two perpendicular axes, as shown by arrows 62 and 63. The remaining components of the support frame are the same as those described above with reference to FIG. 5.
The support frame of FIG. 5 is removable from the panels being dried by means of the wheeled trolley. The support frame of FIG. 6 is retractable, either manually or automatically, along the rail to another part of the booth.
Although the invention has been illustrated by a method of accelerating the drying of a water borne coating, it is clearly applicable to other types of coating. Moreover, the invention is capable of use with panels of a wide variety of shapes: it works best with flat panels, but satisfactory results can still be achieved with less regular configurations. The important feature of the invention is that the air jet is entrained by the panel and that the flow across the panel surface is mainly laminar, and non turbulent.
The booth could incorporate a differential in the rates of bulk air flow from different regions of the ceiling, e.g. rather faster flow in a peripheral region, but even then the flow rate would be less than that of the air from the air movers (or other air suppliers).
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A coating of paint on a panel is dried by directing a narrow jet of air from a supply, preferably from an air mover, held at a predetermined distance from the panel towards one edge region of the panel, the jet being substantially narrower, when it reaches the panel edge region, than the length of the panel edge and the jet being inclined to the plane of the panel such that the air from the jet is entrained by the panel in a spreading laminar flow across the panel surface from that edge region to all the other edges thereof. This induces such laminar flow over substantially the whole surface and replaces vapor-laden air closely adjacent the surface with fresh air to accelerate drying. In a painting booth for cars several such air movers use part of the bulk air flow in the booth.
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BACKGROUND OF THE INVENTION
This application is a continuation-in-part of my copending application, Ser. No. 07/388,475, filed Aug. 2, 1989, now U.S. Pat. No. 4,982,538 and entitled "CONCRETE PANELS, CONCRETE DECKS, PARTS THEREOF, AND APPARATUS AND METHODS FOR THEIR FABRICATION AND USE", which was a continuation-in-part of my then copending application, Ser. No. 07/083,663, entitled "CONCRETE PANELS, CONCRETE DECKS, PARTS THEREOF, AND APPARATUS AND METHODS FOR THEIR FABRICATION AND USE", filed Aug. 7, 1987, and now abandoned.
FIELD OF THE INVENTION
This invention is related to: concrete panels for use in making concrete decks or floors for spanning between structural supports, e.g. pre-cast, pre-stressed concrete panels for constructing reinforced concrete decks for bridges supported by structural beams; parts of such concrete panels, e.g. shear connectors, thread formers, and resilient anchored grout seals; tools for manipulating resilient grout seals; co-acting forms for producing the panels; interior and overhang panels; and apparatus and methods for fabricating and using the panels.
DESCRIPTION OF THE PRIOR ART
The construction of reinforced concrete decks and floors (e.g. on bridges and in buildings) has always been the most labor intensive and most costly component of the superstructure involved, and has been the component that controls the overall rate of progress of the construction. The need for temporary support of the reinforcing steel and freshly poured concrete until the concrete has attained sufficient strength to support itself is a major factor in the cost of such construction. The length of time such support must remain in place to allow the concrete to attain sufficient strength is the major factor in controlling the rate of progress of the structure.
The original method used in modern times to provide the temporary support was a basic wood form made up of boards or plywood sheeting nailed to wood joist members, carried on wood timbers or steel beams, which in turn were supported on posts or columns from the ground or lower completed floor. This method is still used today with the development of a variety of complex high capacity column scaffolding systems and beam members that are adjustable for both span length and camber. Other developments in the use of the basic wood form include hanger systems that provide for hanging the form from the beam members of the permanent structure, thereby eliminating the need of posts or columns from below. This development includes hanging brackets to provide for support of deck or floor that cantilevers off of these beams. Another development involved trussed framing systems that provided for the support of large areas of form on a very few bearing supports, and for the removal and re-setting of such large areas as a single unit.
The cost of using basic wood forms would be prohibitive if they were used just once, but they are normally not consumed or destroyed in a single use and are in fact in normal practice re-used many times before wear and tear makes them unfit for further re-use. The greater the number of re-uses of the forms, the more economical they become. Economics therefore dictates that the effort on any given construction project is to provide the minimum quantity of form that will permit reasonable progress to be achieved on the project, thereby gaining the greatest number of re-uses, even though availability of a greater quantity of form would provide for a faster rate of progress.
The setting of wood forms preparatory to the placement of reinforcing steel and concrete is a labor intensive task by itself, but removing wood forms after the concrete has attained sufficient strength, usually requiring extensive scaffolding, requires a greater amount of costly labor and equipment, and the moving to the location of its next use and the clean up and preparation for re-use of the forms adds more labor and equipment cost.
These high labor and equipment costs, and the limitation of progress inherent in the use of wood forms, has encouraged development of alternate methods of providing support for deck and floor construction. The development of methods using materials that are durable, yet economical enough to be used once and then left in place, are gaining in favor. Some methods provide temporary support only and after the concrete has gained its strength and are simply left idle in place. Light gage galvanized corrugated sheet steel panels supported directly by the permanent structure beams is the most popular of these methods.
Some methods provide temporary support but in addition become an integral permanent working part of the structure when the concrete gains its strength. Heavy gage corrugated sheet steel panels, supported directly by the permanent structure beams, with steel loop shear connectors connected (e.g. by welding) to the panels and then embedded in the concrete to make the panels and the cured concrete work as a composite unit is one example of this method. The most recent development in this area is the pre-cast pre-stressed concrete panel supported directly by the permanent structure beams, and again with shear connectors to make the panels and the cast-in-place concrete work as a composite unit. These panels replace the wood forms and serve both as a form and then as an integral part of the structure. A desired amount of concrete is poured onto the already-formed and already-hardened panel.
In becoming a permanent composite component of the structure, the panels replace structural materials that would otherwise have to be provided in the design of the structure. In the case of the sheet steel panels, part of the reinforcing steel is replaced by the panel. In the case of the pre-stressed concrete panel, part of the reinforcing steel and a substantial part of the concrete is replaced by the panel.
In exposed structures such as bridges, the concrete panels are popular with engineers and architects because they blend in with the appearance of the structure and provide the most natural look. Another important reason is that they are not subject to corrosion that might diminish the appearance of the structure at some later date, or even become a hazard by falling from the structure as sheet steel might do.
The currently popular design of pre-stressed concrete panels leaves serious and costly problems in the construction technique. To accomplish the composite relationship between the panel and the cast-in-place concrete, the first requirement is that the panel have a continuous rigid bearing contact with the top of the supporting beam along its ends. Since neither the top of the beam or the bottom of the panel can be depended upon to be perfectly flat, an intervening material, normally concrete or cement grout, that can be installed in a plastic state so it will conform to both surfaces and then harden in that shape is required. General practice (see FIG. 1) is to place a narrow strip of fiberboard along the edges of the top flange of the supporting beam, to set the concrete panel thereon so the panel overhangs the fiberboard strip over the beam, and then to either force the intervening material in its plastic state under the overhanging part of the panel, or to wait until the cast-in-place concrete is poured and at that time to force grout contained in the concrete mix being used to flow under the overhanging part of the panel. The fiberboard is of sufficient thickness to allow room for the intervening material to be forced under the overhanging part of the panel, and it prevents the plastic material from flowing over the edge of the beam. The fact that the two surfaces are substantially parallel and close together requires substantial effort and great care to insure that this important requirement is actually accomplished, and that no air pockets are entrapped that would reduce the bearing area.
To provide for the deflection of the beams and the design cambers that are required to provide the desired finished grading, the designer and/or the constructor is left with three undesirable options in the use of this method. The thickness of the fiberboard material (or other filler or sealing material) can be varied to compensate for deflection and camber which allows the thickness of the slab to remain constant; the thickness of the slab can be varied to provide the desired top surface grading while the bottom surface follows the deflection of the beams; or the top surface of the beams can be re-graded to provide for deflection and camber with a cast-in-place concrete overlay prior to the placement of the fiberboard strips.
If the thickness of the fiberboard strip is varied, (see FIG. 1) measurement and placement of the strips according to a pre-calculated layout must be done by workmen working on top of the bare beams before the panels can be placed. This is slow and dangerous work, and completed work can easily be knocked or blown off of the beam, and at best the amount of variation that can be accomplished is very limited because excessive thicknesses of the fiberboard become unstable. Methods of using concrete bricks under the panels along with galvanized sheet steel (see FIG. 3) to close the opening between the panel and the top of the beam between bricks are available, but are extremely labor intensive and time consuming. There is no way to adjust panels after they are in place, so if errors are discovered at this time the only way to make corrections is to remove the panels and start over.
If the thickness of the slab is varied, all the variation must be in added thickness, since design requirements are minimum thickness. The cost of the excess concrete is a complete loss and again the amount of variation that can be accomplished is very limited because too much excess material would add too much dead load to the slab and the structure.
Re-grading of the top surface of the beam (see FIG. 2) provides satisfactory results, but is clearly the most costly and time consuming of all of the options.
None of the currently used methods have attempted to improve on or replace the use of the basic wood form to support the overhanging portion of decks or floors. Therefore structures that are designed with overhanging deck or floor currently have the progress limitation problem of the basic wood form, even if other non-restrictive methods of support are used between beams.
The facilities for casting pre-stressed concrete panels consists of a pair of anchorages used to anchor the ends of the pre-stressing strands, with a fixed flat surface between them on which the concrete is poured, and usually with fixed side forms the full length of the flat surface to contain and shape the concrete on the sides of the panels. The most expensive part is the anchorages which must be capable of withstanding tremendous horizontal loads as the pre-stressing strands are stretched between them. The anchorages are therefore usually spaced far apart, and the casting beds are very long (e.g. 300-600 feet) and narrow (e.g. 8 feet wide) so as to provide the greatest possible amount of casting capacity for the pair of anchorages.
Once the casting bed is established, the work of casting the typical panels involves the placing and stressing of the strands, the setting of forms which divide the long bed into the lengths of panels required, and the placing of reinforcing steel and the pouring of the concrete. After the concrete has cured, the strands are released from the anchorages and cut at each form, and the panels are removed from the bed. The setting and removing of the forms is clearly the most difficult of these tasks. The form must have two faces against which the concrete is poured and through which all the strands must pass. The strands are usually spaced on approximately six inch centers across the full width of the bed at mid-depth of the panels. The two faces of the form are spaced apart to provide for the strands to be exposed between panels so that after they are cut, a required length will extend out of the end of each panel to provide anchorage into the cast-in-place concrete when the panel is installed in the bridge or building. Since the strands effectively divide the faces into two halves, the two faces are usually split longitudinally so the lower half can be set below the strands, before the strands are installed, while the upper half is set above the strands, after they are installed. Holes must be provided along the joint between the top and bottom halves of the form with a close enough fit to the strands to prevent excessive grout leakage, and the top and bottom halves must be fixed in alignment at the joint. The forms must be maintained in their selected positions to resist the forces of the concrete being poured against them and the space between the two faces must be covered to prevent it from being filled with concrete. In current practice the typical divider form is made up of a bottom board or a steel channel with wood filler of a width equal to the required space between concrete faces, a thickness equal to the space under the strands, and a length equal to the width of the casting bed. Wood boards the width of the bottom member of a thickness equal to the diameter of the strands, and a length equal to the space between strands, are nailed to the top form, to fill the space between strands and provide a notch for each strand at the proper locations. The top board of the same dimensions as the bottom form is nailed or bolted in place over the strands after they have been placed and stressed.
The pre-cast pre-stressed concrete panels that are in use for deck and floor construction today eliminate some of the need for labor intensive temporary wood support forms to be furnished, set in place, and later removed and prepared for re-cycling. The "set in place one time and never go back" use and therefore the elimination of the need to re-cycle the support means as with temporary wood forms permits the constructor to economically work a much larger area of deck or floor at one time, the only limitation being the re-cycling of the support forms for the overhanging part of the slab. Labor crews and equipment can be utilized more efficiently and progress of the deck or floor is substantially improved. But for all their advantages, there remain distinct problems in the way they are used today. Pre-grading and erecting them in place, especially the pre-grading, is highly labor intensive; forcing grout or concrete under the ends of the panels is difficult; and on structures with substantial overhanging slab area, such as bridges, the overhanging area is dealt with using the basic re-cycling wood form. There has been a long-felt need for efficient and economical apparatuses and methods for casting concrete panels and for making a concrete deck to span structural supports. There has also been a long-felt need for such a deck that is quick to set and easy to grade. The present invention meets and satisfies these needs.
Traffic loads are distributed longitudinally and transversely within the interior areas of the span of a reinforced concrete highway bridge deck or similar structure. However, such loads are distributed transversely only at the ends of a span so that the deck slab at the ends of spans must be supported by a transverse beam or be made stronger. In continuous slab bridges, where two or more spans are connected together and designed to work as a single unit, deflection and deformation induce maximum stress in the deck slab requiring special attention at the interior support points. The currently popular method of providing for meeting these conditions, when precast concrete decking panels are used in the deck construction, is to make the deck slab thicker at the ends of the spans and to use additional longitudinal reinforcing steel at the interior support points. The slab is therefore constructed of full depth cast-in-place concrete in these areas.
The full depth cast-in-place concrete slab requires a support which, as previously described, currently involves the use of a temporary wood form or the use of stay-in-place sheet metal forms. In either case, an extra source of material supply must be dealt with, and separate labor crews of different skills, working at separate times, and with separate equipment, must be employed. There is a need for, and thus an object of this invention, to provide an efficient and economical method to provide for the special requirements in these critical areas using the same source of supply, the same labor crew and equipment as the previously described decking panels.
In accordance with 37 C.F.R. §§1.56 and 1.97, the following references are disclosed:
1. Dayton Superior Bridge Deck Forming Handbook, 1985, which discloses various prior art hangers, decks, overhang brackets, guardrails, precast girders, screed supports, and reinforcing bars.
2. Dayton Superior Precast--Prestressed Concrete Handbook 1986 which discloses various prior art inserts, anchors, braces, and bolts.
3. CMI News, Spring 1982, discloses prior art deck methods.
4. Superior Bridge Deck Forming Handbook, 1977, discloses various prior art hangers, brackets and various methods for making decks.
5. Texas Highway Department Bridge Division, Pre-stressed Concrete Panels Optional Deck Details, 1980, Sheets 129 Band C, discloses prior art panels and methods for making decks.
6. U.S. Pat. No. 122,498 discloses a method for making concrete pavement.
7. U.S. Pat. No. 1,004,410 discloses apparatus for laying concrete.
8. U.S. Pat. No. 1,751,147 discloses a method of lining tunnels with concrete.
10. U.S. Pat. No. 3,646,748 discloses a tendon for prestressed concrete.
11. Russian Patent 502,076 discloses bridge surface concreting machines.
None of these references taken alone or in any combination teaches or suggests the present invention.
SUMMARY OF THE PRESENT INVENTION
The present invention is directed to apparatuses and methods which solve the problems of the prior art and provide the means to set pre-cast pre-stressed concrete panels that span between beams directly on the supporting structural beams with no prior preparation; to adjust the grade of the panels to provide for deflection and camber over a wide range of adjustment before or after setting with little or no loss of material; and to cast the panels with improved bulkhead forms and screw jack hardware. It further provides the means to extend the use of pre-cast pre-stressed concrete panels to the overhanging parts of decks or floors.
In the pre-cast concrete deck panels of this invention, threaded bolts are used to support and provide adjustability of each panel. The seal that contains the grout or concrete that is forced between the bottom of the panel and top of the supporting beam slides on the edge of the beam and is capable of maintaining its sealing action over a wide range of adjustment of the space between the two. At any stage prior to pouring concrete on a panel, the bolt can be adjusted upwardly (or downwardly) and the grout seal will extend sufficiently that the seal between the beam and the panel will be maintained. The grout seal also acts as a concrete form and is capable of resisting the horizontal pressure of the plastic grout or concrete poured against it and thereby prevents it from simply flowing over the edge of the beam. The present invention provides these capabilities with a strip of material, preferably plastic, one portion of which can be secured to or embedded into the bottom of the concrete panel, in the casting bed, on a line that will fall approximately over the edge of the supporting beam when the panel is erected.
In the erection procedure, the strip is positioned to bear against the side of the flange of the supporting beam for the full length of the panel. The preferred plastic is a stiff pliable material (e.g. polypropylene polyurethane or polvinyl chloride) that resists bending but will bend to a high deflection without splitting or cracking, and without deformation so that it will spring back to its original position if not restrained from doing so. In pre-casting the panels the strip can be positioned horizontally on the bottom of the panel with the one edge embedded in the concrete. To gain an improvement in the placement of the grout or concrete under the part of the panel that overlaps the support beam, the strip can be shaped for and positioned to slope up from the embedded edge of the strip to the underside of the strands at the end of the panel. In this way the panel bottom is formed with a slope up from the edge of the supporting beam to the end of the panel so the space between the top of the beam and the overlapping panel, when the panel is installed, forms an open mouthed recess into which grout or concrete can easily flow and from which air can easily escape.
A two-piece co-acting bulkhead form can be used to insure that the plastic strip is held in true position during the concrete pouring operation. The bottom part of the bulkhead form is made with a narrow level surface edging on the face of the form and just under the strands, extending the width of the panel. A matching narrow level extension, with a short turn down at its outer edge, is made a part of the plastic strip.
In preparing the casting bed for a pour, the bottom bulkhead form is set in place in the bed, and the plastic strips are set to it with the narrow level extensions laying on the level surface of the form, and with the short turn down hooked over the inside edge of it. The top bulkhead form is made to set on top of the level extension, between the strands, and with a vertical faced projection extending below the level bearing area that in turn bears against the short turn down of the plastic strip. In this way the top and bottom bulkhead forms can be secured together with the strip firmly held between them.
In the instances where the designer requires the bearing area of the panel to be level, or near level, the plastic strip can be shaped flat. The strip is of a width that will provide for the embedded edge to be positioned over the edge of the supporting beam while the opposite edge extends a short distance beyond the end of the panel to provide for the plastic strip to be held in true position during the concrete pouring operation and to provide a starting tab for bending the plastic strip down in the erection procedure.
To complete the means of holding the plastic strip in true position during the concrete pouring operation, the outer edge of the strip can be turned up. When installed in the casting bed the turned up edge is positioned to extend up into a groove which can be provided in the bottom of the bottom bulkhead form. A short upward protrusion can be spaced back from the outer edge of the plastic strip so it will position just outside of the bottom form to provide an additional holding support and a sight line to assist in quick installation in the casting bed. The bulkhead forms are preferably made of a plastic to which concrete will not bond, e.g. polyurethane, or polyethylene.
A new shear connector is provided to overcome the shearing stress in a beam member and reinforcing a joint in the shear plane. The sliding between two beams one on the other can be characterized as "shear" (such as between a panel and cast-in-place decking on the panel). A shear connector provides a strengthening connection between two such members which overcomes or reduces shear.
To provide for the convenient use of the threaded bolts to be used as adjustable legs for the individual panels that span between structure beams, threaded holes can be formed through one embodiment of panels according to this invention in the casting bed in at least four places. The holes are located to pass through the part of the panel that overhangs the supporting beams so the bolts that pass through them will bear on the beams, and along the length of the panel on the center line between two strands that falls nearest the quarter points of the length. The holes are preferably formed with molded plastic tubing which has been formed to the shape of the thread to be used. Light gauge sheet steel tubing, or a solid or wire nut with formed holes above and below, may be used. To assure that the hole remains plumb and in the correct position throughout the pouring of the panel concrete, securement fixtures with arms of sheet steel, steel wire, or plastic can be attached to the thread forming tubing and, extend and attach to the strand on each side, and a gauging means can be provided to fix the distance from the bulkhead form. By this means the hole forming tubing can be installed in the casting bed and embedded along with the edge of the seal strip as the concrete is poured.
When panels are to be delivered to the structure on which they are to be used, the strips can be moved with the use of a seal depressor that includes one or more curved tines mounted to a rotatable shaft that is located above the panel over the line of the embedded edge of each grout seal strip. Preferably a plurality of tines are used and preferably each tine is a three sided rectangular loop of wire, both ends of which are rigidly mounted to its rotatable shaft. The tines are curved to wrap around the ends of the panel in such a way that when rotated downward they will bear on the narrow level surfaces of the grout seal plastic strips, and upon further downward rotation, push the grout seal strips past the vertical position and thereby position them to pass down between the two supporting beams as the panel is lowered into position. The tines can be located to avoid the threaded bolt leg positions and to pass between strands.
In one embodiment, the seal depressor includes apparatus designed to automatically attach to a panel, activated by the vertical hoisting action of a handling crane, to lift the panel from storage or a delivery vehicle, and to simultaneously depress the seal strips from the horizontal unstressed state as cast, and against their inherent spring resistance, and rotate it to a position that makes it easy to lower the strips down between two adjacent bridge beams as the panel is lowered to its functional position supported above the bridge beams. Once the panel is resting on its temporary supports over the bridge beams, the seal depressor is released from the panel and the seal strips are simultaneously released to spring back against the sides of the bridge beams for a purpose previously described.
The threaded bolt legs can be inserted in the threaded holes at any time after casting, but if not done before erection, they are inserted while the panel is hanging in the lifting frame The bolt legs can be extended to pre-calculated lengths to provide required deflection and camber adjustment at this time, or the panel can be set on the supporting beams, with enough clearance for the rotated tines, and later jacked up to the proper adjustment by rotation of the threaded bolt legs. It is preferred that the grout seal strips are resilient enough and springy so that when they are released they press against the sides of the beams with spring action of sufficient force to resist the horizontal pressures of the grout or concrete to be placed under the panel later. It is also preferred that the grout seal strips' dimensions are such that any adjustment of the panel for grade simply slides the beam seal up or down on the side of the top flange of the supporting beam.
The use of pre-cast concrete deck panels on the overhanging part of the slab has a different set of conditions. Since the overhang is supported by a single structure beam, a pre-cast panel must be supported by the same single beam. The means provided herein to support the pre-cast panel on the overhang, therefore, is with the use of a stable overhang bracket which is hung from the structural beam. The preferred bracket is primarily used to support a rail along the bridge that is designed to carry an assortment of rolling construction equipment used in the setting of the panels and reinforcing steel, and in pouring, shaping, grading, and finishing the cast-in-place concrete. The bracket is adjustable for grade and slope and therefore provides for the necessary pre-grading to adjust for deflection and camber. This bracket construction is more completely described and shown in my U.S. Pat. No. 4,660,800 entitled "Bridge Overhang Bracket and Hanger", Apr. 28, 1987, which patent is incorporated herein for all purposes. By this method the panels for the overhang span from bracket to bracket alongside the structural support beam rather than from beam to beam.
With the fundamental advantages of the use of precast concrete panels on the overhand established, and the basic application and method of support and adjustment provided for, two specific panel designs are needed to provide for two different structure designer requirements. The efficiency and safety of the traffic control barrier on the overhanging edges of most federal highway bridges, and the stresses that develop therefrom have been established through extensive and costly full scale testing programs sponsored by the Federal Government. This same program has established specific designs for the overhanging portion of applicable highway bridge decks and in this case, no basic design variation is normally considered. A precast panel that changes only the construction procedure and minor details is necessary. Alternately, a pre-stressed concrete panel that allows for greater flexibility in its application is desirable.
To provide for the case where the design of the overhang is predetermined and only the construction procedure is to be improved by the use of precast concrete panels, the panels are designed with a width to overhang the top flange of the structural beam, as with the interior panels, and, to avoid an unsightly horizontal joint, with the full outside face of the overhand as its outer edge. Horizontal adjustability is provided for variable overhang widths in curves and turn outs, and again for tolerance by variation of the distance the panel overhangs the structural beam. The panels are designed with a length equal to the spacing of the supporting overhang brackets, less a short distance to allow space for end-to-end misalignment necessary to install the panels on horizontal and vertical curves, and again for tolerance. In the erection of the panels the gap so created can be filed with a flexible, compressible material such as plastic foam to prevent grout leakage.
In order to maintain predetermined structural design, as a minimum, all of the reinforcing steel called for in the applicable structure design, any part of which falls within the volume occupied by the panel concrete, can be cast into the panel in the casting yard. Additional reinforcing steel, or pre-stressing strands, may be added to provide for shear connection between the panel and the cast-in-place concrete to insure that they act as a composite unit, for handling, and for spanning between overhang brackets while the panel serves as the support form.
Panels can be provided according to the present invention which have as an integral part thereof some or all of the steel necessary to effect the designed deck or floor.
To provide the grout seal between the bottom of the panel and the top of the structure beam over the full range of vertical adjustment required, and to provide temporary support for the panel, an angle of either steel or plastic can be attached to the overhang brackets to span between them and is placed against the outer vertical face of the flange of the structure beam, in such a way that it adjusts vertically with the bracket (see FIG. 15). The angle is removed with the brackets after the cast-in-place concrete has cured sufficiently for the overhang to support itself.
To provide for the case where a more economical panel with greater flexibility of design is allowable, a purely pre-stressed design can be used (see FIG. 16). Since the panel spans from bracket to bracket parallel to the structure beam, the pre-stressing strands also run parallel to the beam. In this configuration, the strands serve primarily in the temporary support of the cast-in-place concrete, but the concrete of the panels works in composite action with and replaces a substantial portion of the cast-in-place concrete. Since the overhang is a cantilever in the permanent structure, the panel concrete forming the bottom portion of the cantilevering slab is stressed only in compression. And since the pre-stressed concrete is a denser stronger concrete then the cast-in-place concrete, the pre-stress loads normal to the live loads are not normally detrimental.
In accordance with a further novel aspect of the present invention, precast concrete forming panels, similar to the precast concrete decking panels used for the general deck construction, as above described, are used to provide the temporary support for the full depth cast-in-place concrete and are left in place in the same way that sheet metal forms are. Thus, the precast concrete forming panels are supported from the opposite sides of the support beams of adjacent rows so as to span the gap between them in a close fit. Each such forming panel is so supported by a hanger which comprises a beam connected intermediate its ends to the forming panel with its inner end on the top of the panel and its overhanging outer end on the top of a support beam. More particularly, and as in the case of the decking panels, bolts engage at their lower ends with the top of the support beam, whereby each such bolt may be adjusted to act as a jack screw to raise or lower the forming panel.
Holes extend on each side of the panel adjacent to the bridge support beam, and bolts extend through the holes in the panel and the hanger beam member to connect the hanger beam to the panel with its one end bearing on the panel to provide for reaction for a load imposed through the bolts at the overhanging end. In one form, the hanger beam comprises spaced metal channels connected to opposite sides of wire nuts, and, in another form, the hanger can be a molded plastic body in which the threaded holes on its outer end are integrally formed.
Thus, when the forming panels are supported between adjacent support beams, their top surfaces can be graded to the bottom elevation of the structural cast-in-place slab to be poured thereover, and thereby shape and support the cast-in-place concrete until it cures. Thereafter, the forming panels are left in place to avoid the cost and time to remove them.
It is, therefore, an object of the present invention to provide novel, efficient, and economical apparatuses and methods for forming concrete decks or floors between structural supports.
Another object of the present invention is the provision of a pre-cast concrete panel which can span between structural supports and can rest directly on the supports with no prior preparation.
Yet another object of the present invention is the provision of such panels with apparatus for adjusting the grade of the panels to provide for deflection and camber before or after setting with little loss of material.
An additional object of the present invention is the provision of a grout seal strip for such panels and of a panel with such a grout seal strip.
Another object of the invention is the provision of a grout seal strip with an anchor for embedment in a concrete panel.
Yet another object of the present invention is the provision of such a grout seal strip which is resilient and of such dimensions that it can contain grout between the panel and the support.
An additional object of the present invention is the provision of concrete panels with either a flat bottom or a partially-sloped bottom.
Another object of the present invention is the provision of such panels with threads formed therethrough for receiving a threaded bolt to provide adjustment for deflection and camber.
A further object of the present invention is the provision of a thread former for providing such threads.
Yet another object of the present invention is the provision of a seal depressor for manipulating the grout seal strips.
Another object of the present invention is the provision of a casting bed apparatus and method for employing the new bulkhead forms and for producing panels according to the present invention.
Yet another object of the present invention is the provision of a novel and efficient shear connector for mechanically connecting the cast-in-place concrete to the panel to insure that they work together as a composite unit.
A particular object of the present invention is the provision of a concrete panel which has as an integral part thereof the necessary designed steel for constructing the proposed deck or floor.
Another object of the present invention is the provision of apparatuses and methods which are creatively simple so that the possibility of errors in use and fabrication are significantly reduced; i.e., "fool-proof" apparatuses and methods such as thread formers with gage rods to insure proper placement and two-piece mating bulkhead forms which can only fit together properly in one manner.
To those of skill in this art who have the benefit of this invention's teachings, other and further features, objects, and advantages will be clear from the following description of preferred embodiments where taken in conjunction with the drawings, all of which are given for the purpose of disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-3 are side cross-sectional views of prior art support beams, panels and decks.
FIG. 4 is a side cross-sectional view of an end of a panel and seal strip constructed in accordance with one embodiment of the present invention.
FIG. 4A is a side cross-sectional view of an end of the panel of FIG. 4 atop a support beam and with the seal strip bent to a position engaging a side edge of the panel and a bolt lowered through a thread form to space the panel above the beam.
FIG. 5 is an isometric view of the entire panel of FIG. 4A.
FIG. 6 is a side cross-sectional view of a portion of a bulkhead form, a thread former and a seal strip constructed in accordance with another embodiment of the present invention and prior to casting of a panel.
FIG. 6A is a side cross-sectional view of an end of a panel having the seal strip of FIG. 6 cast therein and mounted atop a support beam with the seal strip and a bolt in the thread former in the positions shown in FIG. 5A.
FIG. 7 is a side cross-sectional view of a panel and seal depressor according to the present invention.
FIG. 8 is a top view of the seal depressor of FIG. 7.
FIG. 9 is a side cross-sectional view of a bulkhead form, grout seal strip and thread former prior to casting the panel of FIG. 4A.
FIG. 10 is an exploded view of the items of FIG. 9.
FIG. 11 is a schematic top plan view of a casting bed with bulkhead forms, thread formers, and grout seal strips according to the present invention.
FIG. 12 is a top plan view of a portion of the casting bed showing the details of employment of a thread former according to the present invention.
FIG. 13 is a side cross-sectional view showing the use of an overhang panel.
FIG. 14 is a side cross-sectional view of an overhang panel according to the present invention.
FIG. 15 is a side cross-sectional view showing the use of the overhang panel of FIG. 14.
FIG. 16 is a side view partially in cross-section of a bridge deck in formation and apparatus for forming it.
FIG. 17 is an end view of a tool including a seal depressor positioned above a stack of panels prior to lowering onto the top panel for attaching to it and lifting it to a locating for lowering onto laterally spaced beams.
FIG. 18 if a perspective view of the tool as it lowers the panel onto the beams and showing the seal strips rotated into depressed positions for passing between the inner edged of the beams.
FIG. 19 is a view of the beams with the panels following mounted thereon and upon raising of the tool therefrom and with the seal strips released from the depressor to engage the edges of the beams.
FIG. 20 is an enlarged end view of the tool shown in FIG. 17, and with the seal depressors rotated into positions depressing the seal strips and attached to the panel.
FIG. 21 is a side view of the tool and panel with the tines of the depressor in panel releasing position.
FIG. 22 is an enlarged, detailed sectional view of the depressor in seal strip depressing position and showing a device which urges it to releasing position.
FIG. 23 is a top plan view of longitudinally extending, laterally spaced apart rows of support beams having decking panels supported thereon and spanning between the beams of adjacent rows and forming panels supported by hangers along their opposite longitudinal sides to dispose their side edges closely between the opposite sides of the spaced beams and their laterally extending ends beneath the overhanging, laterally extending ends of the decking panels near the ends of the beams intermediate the ends as well as adjacent the end of the bridge span;
FIG. 23A is a cross-sectional view, as seen along broken lines A--A of FIG. 23, of one of the support beams and the sides of a pair of decking panels supported above the sides of the beam by means of bolts imbedded in the beams and showing seal strips on the decking panels engaged with the side edges of the beam in order to contain grout between the bottoms of the panels and tops of the support beams, as shown, for example, in the embodiments of the invention shown in FIGS. 6A and 7A;
FIG. 23B is another cross-sectional view, as shown along broken lines B--B of FIG. 23, showing a support beam with a pair of forming panels having their side edges disposed closely within the sides of the beam and supported therefrom by means of hangers constructed in accordance with the present invention;
FIG. 23C is a further cross-sectional view, as seen along broken lines C--C of FIG. 23, showing the sides of adjacent, end-to-end support beams, and adjacent sides of decking and forming panels with the laterally extending end of the forming panels beneath the laterally extending end of the decking panels;
FIG. 23D is a still further cross-sectional view, as seen along broken lines D--D of FIG. 23, of the side of a support beam at one end of the bridge span, together with a decking panel having hangers to support one side thereof from the end of a beam with one laterally extending edge beneath the laterally extending edge of the decking panel;
FIG. 23E is a cross-sectional view, as seen along broken lines E--E of FIG. 23, of portions of laterally spaced apart support beams and a decking panel supported therefrom as well as a forming panel having hangers mounted on its sides to support it with its longitudinally extending side edges closely adjacent the sides of the beams;
FIG. 23F is a cross-sectional view, as seen along broken lines F--F of FIG. 23, showing portions of a pair of laterally spaced apart support beams, together with a decking panel having its sides supported from the beams as well as a forming panel supported by hangers with its longitudinally extending edges closely adjacent the sides of the beams, as in the case of FIG. 23E, but differing from FIG. 23E in that the top of the forming panel is supported at a lower level and a strip of fiberboard or the like closes a space between the lower top of the forming panel and the bottom of the decking panel;
FIG. 24A is a perspective view of an intermediate portion of the bridge span shown in FIG. 23, as seen from the top and one side thereof, and showing the interior forming and decking panels as illustrated in FIGS. 23B and 23C, as well as a broken away portion of a slab poured in place over the tops of the support beams, decking panels and forming panels;
FIG. 24B is a perspective view similar to FIG. 23, but of an end portion of the bridge span and showing portions of the support beams, decking panels and forming panels illustrated in FIGS. 23D and 23F;
FIG. 25 is an enlarged cross-sectional view of adjacent sides of a support beam and forming panel, as in FIG. 23B, but showing details of the hanger which supports the forming panel from the beam;
FIG. 25A is a side view of the beam of the hanger of FIG. 25, including thread formers shown in broken lines for receiving bolts for connecting the beam to the forming panel in a position to support the forming panel from an adjacent side of the support beam;
FIG. 25B is a top plan view of the beam of FIG. 25A and showing the laterally spaced apart channels mounted on opposite sides of the thread formers;
FIG. 26 is an enlarged cross-sectional view of adjacent longitudinal sides of a support beam and forming panel, as in FIG. 23B, but showing an alternative form of hanger, having an integral or one-piece cast plastic body in which the thread formers are mounted;
FIG. 26A is a side view of the body of the hanger of FIG. 26, with the bolts removed from the thread formers thereof;
FIG. 26B is a top view of the body of the hanger of FIG. 26A.
FIG. 26C is an enlarged side cross-sectional of a bulkhead, grout seal strip, thread former and end of a panel, as shown in FIG. 9 as seen along line A--A of FIG. 27.
FIG. 27 is a cross-sectional view of the apparatus of FIG. 26C along line B--B of FIG. 26C.
FIG. 28A is an isometric view of the thread former device of FIG. 26C.
FIG. 28B is an isometric view of a thread former according to the present invention.
FIG. 29 is a side cross-sectional view of a shear connector according to the present invention.
FIG. 30 is a side cross-sectional view of part of a panel and a shear connector according to the present invention.
FIG. 31 is a top plan view of the apparatus of FIG. 30.
FIG. 32 is a side cross-sectional view of an overhang panel according to the present invention and FIG. 33 is atop view of the panel.
FIG. 34 is a top view of the panel shown in FIG. 14.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 illustrates typical prior art deck forming apparatuses and methods. Concrete panels A are emplaced on fiberboard inserts B on a support beam C. A metal loop D embedded in the beam C extends up into the poured concrete deck E. Poured concrete has filled the gaps F between the panel ends and the beam's top surface.
FIGS. 2 and 3 illustrate additional typical prior art deck forming apparatuses and methods for use where the distance between the top of a support beam and the finished grade cannot be achieved within desired tolerances with cast-in-place slab thickness and fiberboard. In FIG. 2 additional height is provided by using a cast-in-place concrete overlay G to re-grade the top surface of the beam C. In FIG. 3 additional height is provided by emplacing concrete blocks J along the edges of the panels A. Sheet metal angles K are used between the blocks J and the panels A for the purpose of sealing the space between the panel and the top of the beam to prevent the grout or concrete from flowing over the edge of the beam between concrete blocks. Fiberboard B is used between the concrete blocks J and the panels A.
FIG. 4 illustrates a portion of the end of a pre-cast pre-stressed concrete decking panel 10 according to the present invention. The panel 10 has a hollow thread former 12 embedded therein and a resilient grout seal strip 14 anchored therein. A strand 16 of pre-stressed steel is shown embedded in the panel 10 and passing by the thread former 12. A dual arm securement fixture 18 is disposed about the thread former 12 and is secured to the strand 16. A removable cap 20 closes off the top of the thread former 12 to prevent the influx of debris or other unwanted material into the interior of the thread former.
The thin, elongate grout seal strip 14 has an anchor 22 formed integrally thereof on its upper face and extending therefrom for anchoring the strip 14 to the panel 10. A small semicircular hinge portion 26 can be formed integrally of the grout strip 14 along its length and intermediate inner and outer elongated portions 24a and 24 of the strip on the inner and outer sides of the hinge portion, whereby the strip may be rotated about the anchor 22. The anchor means is adjacent the hinge so as to facilitate swinging of inner elongate portion 24a about the hinge. As will be described in more detail below, to facilitate emplacement of the grout strip 14 in a casting bed, the outer edge of the inner elongate portion of the grout strip 14 extends beyond the panel and is provided with an L-shaped portion 28 with the base of the L pointing down.
The exterior valleys 30 of the thread former 12 are filled with concrete when the panel 10 is cast. This reinforces the thread former 12 and holds it in place. The cap 20 is also provided with exterior valleys 31 so that continuous threads extend from the top to the bottom of the panel end. During casting of the panel, the grout seal strip 14 closes off the lower end of the thread former 12.
A panel 32 illustrated in FIG. 4A is similar to the panel 10 of FIG. 4. The panel 32 has grout seal strips 14 anchored therein with an anchor 22; a thread former 12 with a fixture 18 embedded therein; and a steel strand 16 running therethrough. The panel 32 is shown in FIG. 5 above a support beam 34. A bolt 36 threadedly extending through the thread former 12 projects beyond the panel 32 to provide a desired separation distance between the beam 34 and the bottom of the panel 32. The resilient grout seal strip 14 is made of a relatively stiff material so that, when unstressed, its elongate portions are in general alignment with one another, whereby the upper face of the strip provides part of a form for the bottom of the panel. As shown in FIG. 4A, it has been bent back about the hinge 26 and, due to its springiness and resiliency, the upper face of the inner elongate portion is urged against and slidable over the side edge of the beam 34. As shown, it provides a greater volume between the panel 32 and the beam 34 than if it were horizontal. The sloped portion 38 also makes it easier to introduce grout or concrete into the area between the panel 32 and the beam 34. The grout seal strip 14 is urged against the beam 34 with sufficient force to hold grout or concrete in the area between the panel 32 and the beam 34 and to provide a seal so that grout or concrete does not escape past the strip 14.
A panel 40 shown in FIG. 6A is similar to the panels 10 and 32, but it has a substantially horizontal bottom surface 42 and substantially straight grout seal strip 44. The thread former 12 of panel 40, bolt 36, fixture 18 and steel strand 16 are like these items in the panels 10 and 32. The inner elongate portion of the grout seal strip 44 has a tab 46 and an angled end 48 for facilitating fabrication of the panel 40 (as will be described in more detail below). The grout seal strip 44 sealingly closes off the area between the panel 40 and a beam 47. The bolt 36 maintains the panel 40 and beam 47 in a desired spaced-apart relation.
A seal strip depressor 50 is shown in FIG. 7 for moving the grout seal strip 14 of the panel 32. The dotted line drawing of the depressor 50 shows it in engagement with the strip 14. A tine loop 52 of the depressor 50 moves so as to avoid contact with a steel strand 16, yet so that it will contact the end 28 of the inner elongate portion of the strip 14 and move the strip 14 out of the way of a support over which the panel 32 is to be installed. FIG. 8 shows a top view of the items of FIG. 7, including the grout seal depressor 50 with a plurality of tine loops 52 connected to the shaft 51 and two operator handles 53 also connected to the shaft 51. As shown in FIGS. 7 and 8, hinge retainers 55 are used to hold the shaft 51 of the depressor in place. The hinge retainers 55 have a slot or hole through which the bolts 36 pass. The hinge retainers are held in place with a running nut 57 and a washer 59.
A casting bed 60 according to the present invention is shown in FIG. 11. Panels such as panels 10, 32, and 40 are fabricated in a casting bed such as the casting bed 60. Bulkheads are positioned across the width of the bed; steel strands and various fixtures are positioned within the bed; and then concrete is introduced into the bed to cover the steel strands. Upon hardening, concrete panels are formed which can be removed from the bed and used as panels for forming decks, floors, etc.
FIGS. 9 and 10 illustrate various components and fixtures used to make a panel such as the panels 10 and 32. A two-piece bulkhead 62 is used. A bottom piece 64 is first placed in the casting bed 60 across its width. The bottom piece 64 has a bottom member 66, two sides 68, each side 68 having an in-turned lip 70. Next grout seal strips 14 are placed in the bed with the L-shaped end emplaced over the lips 70 of the bottom piece 64. The end 24 of the strips 14 rests on the floor 72 of the casting bed 60. Then a steel strand 16 is placed on top of the piece 64. The top piece 72 of the bulkhead 62 is emplaced above the bottom piece 64. Recesses in the top piece 72 (see dotted lines) receive and hold the steel strands 16. The top piece 72 has two downwardly depending legs 74 which are securingly received in the space between the in-turned lips 70 of the bottom piece 64 of the bulkhead 62. Shoulders 76 of the top piece 72 press against the surface of the strips 14 and assist in holding the strips in place during the operation. Thread formers 12 with securement fixtures 18 are disposed in the casting bed with the securement fixtures 18 firmly attached to steel strands such as the strand 16. A cap (not shown in FIG. 9) is added to close-off the top of the thread formers.
The detail of FIG. 6 is similar to that of FIG. 9, but it shows the bulkhead form and grout seal strip for a panel such as panel 40. As shown in FIG. 6, the bulkhead form 78 has a bottom piece 80 and a top piece 82. The bottom piece 80 has an indentation 84 for receiving an end 48 of a strip 44. A tab 46 of a strip 44 abuts the side of the bottom piece 80 to further secure the strip 44 in place during the operation.
FIG. 16 illustrates the use of a thread former 12 in the fabrication of a panel according to the present invention such as panel 10. A thread former 12 has a central tubular member 86 made of sheet steel tube to which are secured two arms 88 made of sheet steel. Each arm 88 has a semicircular finger and an L-shaped, bendable crimpable finger. The fingers provide means for securing their respective arms to steel strands 16 within a casting bed. The semicircular finger is wrapped around a steel strand and the arm is laid on an adjacent strand. The crimpable finger is then bent or crimped around the adjacent strand. The thread former 12 is emplaced near a bulkhead form so that gage rods 94 disposed under and secured to the arms 88 are in contact with the bulkhead form, insuring proper positioning of the thread formers. The tubular member 86 can be connected to the arms 88 by resistance welding or brazing. Gage rods 94 are similarly connected to the arms 88.
An alternative, a thread former has a central tubular threaded member about which is secured a securement fixture. The fixture has a central hollow cylindrical member which is disposed about the tubular member and a plurality of arms 148 extending outwardly for connection to steel strands 16. Each arm 148 has a semicircular grip ring 150 at its end for emplacement about a strand 16. It is within the scope of this invention to use one or more such arms. When using two or more opposed arms the thread former will support itself on strands 16. The thread former can be an integral molded unitary piece or the tubular member can be a piece separate from the fixture. The fixture can be secured to the tubular member such as by welding or gluing or it can simply be emplaced about the tubular member with no further connection. The tubular member and fixture can be formed of plastic, metal, wood or any other suitable material.
In the casting bed procedure illustrated in FIG. 15. Step I is the installation of the bottom piece of a two-piece bulkhead form and the emplacement of grout seal strips in the bed. Step III is the installation of the top piece of a two-piece bulkhead form and Step IV is the installation of the thread formers ("jack embeds"). "Rein Steel" is the reinforcing steel used to resist internal stresses transverse to the prestressing strands.
In Step II lengthwise steel strands are disposed in the casting bed over the bottom pieces of the two-piece bulkhead forms. The steel strands are then anchored and stressed in a conventional prior art manner. In step V concrete shear connectors and thread former ("jack embeds") are installed (as is described in more detail below). Finally, concrete is introduced into the bed to form the panels.
The shear connector has a threaded central member and an upwardly extending figure-eight multiple loop member. The shear connector is preferably made from steel to provide maximum shear strength.
To permit emplacement of the shear connectors in a panel, shear connector thread formers are secured in the casting bed 60 (see discussion of Step V, above). The shear connector thread formers are similar to the thread former 12 and are used with securement fixtures, but without gage rods. The figure-eight loop configuration is helpful because it anchors into a relatively large amount of cast-in-place concrete.
FIGS. 22, 23 and 25 relate to the overhanging portion of a deck and to overhang panels. As shown in FIG. 22 an overhang panel 110 has a main body with strands 16 therethrough, an outwardly extending sloping side member, downwardly extending bottom member 116, and an inner keyway 118. An overhang panel is employed, for example, on the outermost structural support beam of a bridge deck. As shown in FIG. 13, the panel 110 is set on wood blocking 113 with downwardly extending bottom member 116 against the side of a beam 107. Wood blocking 113 is supported by an overhang bracket 111 (as shown in FIG. 15). The overhang bracket 111 is suspended from the beam 107 by the use of a steel hanger 109 which will be encased in cast-in-place reinforced concrete 119. An upward extension arm 115 of the overhang bracket 111 is secured to hanger 109 by a nut 117 which also will be encased in the reinforced concrete, while the bolt fastened thereto and upward extension 115 will be withdrawn after the reinforced concrete 119 has cured. The overhang bracket 111 provides adjustability to set the panel 110 to predetermined grade while the downwardly extending bottom member 116 provides the containment seal to prevent the loss of reinforced concrete 119. After the reinforced concrete 119 has cured, the panel 110 acts as a composite unit with it, gaining vertical support through inner keyway 118 and horizontal support from the reinforced concrete 119 cast over and bonded to it.
FIGS. 23 and 25 illustrate another embodiment of an overhang panel 120 according to the present invention. The panel 120 has reinforcing steel bars 122 and 124 partially embedded therein. These steel bars will become part of a deck once covered with concrete. Foam 121 can be used between panels to allow for contraction and expansion. As shown in FIG. 15, the overhang panel 120 is emplaced on an outermost support beam of a bridge deck. The dotted line in the figure indicates the extent to which concrete 119 is poured over the panel 120 (and other panels) to form the deck. The steel bars 122 and 124 become completely enclosed in concrete 119 and they help to form a strong deck and a strong sidewall. Similar to the support described in FIG. 13, the panel 120 is set on wood blocking 113 with its inward edge 121 overhanging beam 107. Overhang bracket 111 is as described in FIG. 13. Angle 123 is supported by timber blocking 113 and is set against the side of beam 107 to provide the containment seal to prevent the loss of reinforced concrete 119.
FIG. 16 shows a four-beam configuration with four structural support beams 130, three interior panels 132 according to the present invention (similar to panels 10 and 32 described above), and two overhang panels 134 according to the present invention (similar to overhang panel 110 described above). The dotted line above the panels indicates the level to which concrete will be poured above the panels to form the deck. The cantilever overhang panel support is described in my previous U.S. Pat. No. 4,660,800. The system 136 for introducing concrete on the panels is a conventional prior art system.
The tool shown in FIGS. 17 to 22 has a main structural framework 202 made up of two end frames 204 and 206 each made up of two vertical legs 208, spaced apart to center between the outer strand 210 and its adjacent strand 211 at each edge of 2 minimum width panels by being rigidly attached to a cross beam 214 at their top ends. The two end frames 204 and 206 are rigidly attached to a spacer beam 216 made up of two rectangular tubes, one telescoping into the other to permit the length of the spacer beam to be adjusted to different panel widths. That is, the tubes may be moved to and fixed in desired positions by any suitable means.
Panels are cast in an infinite variety of sizes. The space between the beams in a bridge span is variable, so the span dimension of the panels, parallel to the prestressing strands, varies to span between the beams for each bridge span. Bridge span length vary, so the width dimension of the panels, perpendicular to the strands, varies to provide a combination of panel widths to match the needs of each bridge span length. The width of the panels is limited by the width of the casting bed, and the design engineer sets a minimum width. The length of the panel is limited only by its structural strength.
At a point that provides proper clearance above the panel, when the tool is attached thereto, a tube 242 is fixed into each leg 208, aligned to allow the passage of a rotatable shaft 244 through the two legs 208 of each end frame 204 and 206. The rotatable shaft 244 passing through the legs 208 is a round tube equal in length to the maximum width of the panel, and is installed to extend equally from each leg 208. Below the tube, a guide foot 246 is fixed to the legs 208 over the hinge line of seal strips 248 cast into the panel. Each guide foot 245 is an angle with a horizontal leg 250 of a length to position the legs 208, as above, when a vertical downward leg 252 bears against the end 256 of the panel. The length of the angle is equal to the space between the strands in the panel as shown in FIG. 21 and is fixed to the leg 208 with a tubular member 260 reinforced with ribs 262, and has a cutout 264 in the horizontal leg 250 to allow for the passage of a temporary support bolt 266 on the panel if one happens to fall at that location. The vertical leg 252 has an extension 268 bent outward at a 45 degree angle to help guide the frame 202 into proper position relative to the ends of the panel, and shaped at its side edges to help guide the frame 202 to center the legs 208 between two strands 210 and 211 as the tool is lowered onto the panel.
The seal depressor includes a number of depressing tines 272 spaced along each shaft 248. Each tine 272 is a strip of metal formed to a shape so that, in its depressed position 274 (shown in dotted lines in FIG. 20) wraps downward around the end of the panel, and then back under the panel to a point slightly beyond the hinge line 248 of the seal strip 270.
The prestress strands are always uniformly spaced, and the width of any panel is always a multiple of that spacing with a strand centered in each space. Panel temporary support bolts 266 vary in position, depending on the width of the panel but are always positioned on a centerline between two strands. The tines 272 are therefore positioned along the shaft 244 in pairs 278, with tines 272 of each pair 278 spaced apart to allow for clear passage over the protruding strand as they are rotated down to depress the seal strip 270. Each pair 278 is positioned along the shaft 244 at a spacing equal to the strand spacing. The tine pairs 278 are narrow in width so the clear space between them allows clearance for the temporary support bolts 266, both for access to install the bolts from the top at any position of the tines 272, and below the panel where they protrude to support then panel when the tines 272 are in the depressed position 274.
The tines 272 between the legs 208, and the first pair 278 outside of each leg 208, are within the minimum panel width and are therefore needed for handling every pane. They are therefore fixed to pipe spools 280 and 282 that are sized to fit the shaft 244 and are shear pin fixed to the shaft 244. The tines 272 outside the minimum panel width are needed only to the extent of the width of each panel, and any tines 272 beyond the width of that panel would be an obstacle to the placement of the panel against another already in place as required, if they were in the depressed position 274. Each pair of tines 278 outside of the minimum panel width is therefore fixed to a separate pipe spool 284 of a length equal to the strand spacing and provided with a spring loaded shear pin 286 so it can be individually pinned to the shaft 244 in alignment with the fixed tines, or rotated upward and pinned out of the way as shown by broken lines 287 in FIG. 20.
The shaft 244 and tines 272 are spring loaded to the released solid line position shown in FIGS. 17 and 20. In order to allow for the rotation of the shaft 244 and tines 272 to the attaching broken line positions of FIG. 20, the cam is fixed near each end of the spools 280 that are fixed between the legs 208 of each end frame 204 and 206. A push rod 296 of a tube 292 is fixed to the inside of each leg 208 for engaging a cam 290. The tube is positioned so the center line of the rod passes to the inside of the center line of the shaft 244 in order to effect a moment arm about the shaft 244. As shown in FIG. 20, the tubes 292 upper end 294 is tilted to the outside of beams 214 of the end frames 204 and 206 to provide clear access for insertion of the push rod 296 and a compression coil spring 302 into the tube (see FIG. 22).
The bottom of the tube 292 is spaced above the cam 290 to provide clearance at the highest throw position of the cam 290 (FIG. 22), and a washer 298 is attached to receive and guide the push rod 296. The interior of the top of the tube 284 is threaded to receive the matching thread of a spring loading plug 298. The plug 298 has a hole through it to receive and guide the top of the push rod 296, and the top portion of it is hex shaped to provide for the use of a wrench to install it. The rod 296 is of such length that when bearing against the cam 290 at the rods maximum downward travel point, it will protrude from the tube 292 a short distance.
A spring bearing washer 300 sized to fit inside of the tube 292 is fixed to the rod 296 at a short distance above the bottom of the tube 298 when the rod 296 is at its maximum downward travel point. The compression coil spring 302 is inserted to fit over the push rod 296 and inside of the tube 292. The spring 302 is of such length that when it is resting on the spring bearing washer 300 with the rod 296 at maximum downward travel, its top is a short distance inside the tube 292 so the plug 298 can be started into the threads at the top of the tube 294. The plug 298 is then screwed into the tube 292 to compress the spring 302 to apply a preload of the rod 296 against the cam 290 to rotate the shaft 244 to the position where the tines 272 are in the release position 288. The cam 290 is shaped so that rotation of the shaft 244 to depress the seal strips 70 pushes the rod 96 against the spring 302, creating an ever increasing spring pressure to return the tines 272 to the release solid line position 288.
In order to activate the rotation of the shaft 244 to depress the seal strips 270 a lever 304 is made a part of the spool 282 that is fixed to the shaft 244 just outside of each leg 208. When the tines 272 are in the release solid line (FIG. 20) position, the levers 304 are in a generally horizontal position. The end of the lever 304 is formed into a fork 306 and a hole is drilled through both prongs for the insertion of a rotatable pin 308, parallel to the main shaft 244. A hole 310 is drilled and tapped on the diagonal center line of the pin 308 to accept and anchor the threaded sleeve end 312 of an operating cable 314. Free rotation of the pin 308 provides for a straight pull of the cable 314 throughout the full swing of the lever 304.
A cable sheave 316 is mounted near the top of and on the outside of each leg 208. The sheave 316 is mounted on a cantilever shaft 318 which is fixed to a reinforcing base plate 320 which is in turn fixed to the leg 208 to position the sheave in the plane of the swing of the lever 304. A spreader bar 322 made of a piece of pipe a little longer than the distance between the two sheaves 316 on one end frame 204 or 206 is used on each end 204 and 206 to connect the lever operating cables 314 to a four legged wire rope sling 316 suspended from the handling crane. A hole is drilled in each end of each spreader 322 in the plane of the lever 304 and sheave 316 for the other threaded sleeve end 326 of the cables 314 to pass through and be anchored with a nut 328. A vertical plate barrier 230 is fixed to the top outer edge of the end frame 204 and 206 to prevent the spreader 322 from falling off of the end frame 204 and 206 under the pull of the cables 314. Bar loops 232 are fixed to the spreader 322 opposite the operating cable end 326 for making up to the sling 316 with shackles.
With the seal depressor set in place on a panel and the cables 314 and sling 316 rigged as above, the hoisting action of the crane first pulls the operating cables 314 over their sheaves 316 to rotate the levers 304, the shaft 244 to which they are fixed, and the tines 272 which are fixed to the shafts 244, to depress the seal strips 270 and contain and support the panel 254 in their grip by engaging its outer end edges, as shown in broken lines in FIG. 20. Continuation of the hoisting action lifts the panel which is then maneuvered to the desired position on the beams and set down. As the weight of the panel is transferred to the temporary support bolts 266, which have been lowered, continued lowering by the crane permits the spring load on the shaft 244 which causes it to rotate to the release position 288 with the spreader bars 322 bearing on the top of the end frames 204 and 206.
To allow the seal depressor to now be removed by the hoisting of the crane, the travel of the operating cables 314 must be prevented so they will not repeat the depressing of seal strips 270 and containment of the panel 254. To prevent the spreader bars 322 from moving, and thereby the cables 314, at this stage in the operation, a hinged hook 334 is attached to each end frame beam 214 near its center. When the hook 334 is rotated to the inside, it extends over the spreader bar 322 to prevent any movement of the bar, and when it is rotated outward, free movement of the spreader bar 322 is unobstructed. The hook 334 is lightly spring loaded in any suitable manner to the illustrated locked position and the shape of its upper inside edge 338 is such that when the spreader bar 322 is lowered under the force of the spring load of shaft 244, as a panel that has been placed is released, the spreader bar 322 will push the hook 334 back out of its way as it passes and the hook 334 will spring back to lock the bar 322 after it passes. A vertical extension 340 above the shaped edge 338 provides a handle for use in manually releasing the spreader bar 322. To permit the release of both spreader bars 322 by one man, the two hooks 334 are linked together. Preferably, the hooks are linked to one another for movement, together in response to actuation of only one of them.
Referring now to the details of the portion of the reinforced concrete deck shown in FIG. 23, a plurality of reinforced concrete support beams 400 extend longitudinally in laterally spaced apart rows, each row comprising end-to-end interior beams 400A and end beams 400B. Each of the beams 400A and 400B may be of identical construction, except that, for reasons to be described, the outermost ends of the end beams 400 have depressed top surfaces 401.
The deck construction shown in FIG. 23 also includes a plurality of reinforced concrete decking panels 402 arranged in laterally spaced apart, longitudinally extending rows and supported on support beams of adjacent rows thereof to span the space between them. More particularly, the longitudinally extending sides of the decking panels are supported on the tops of the longitudinal sides of the beams and are arranged, intermediate the ends of the support beams, in end-to-end engagement with one another to form a longitudinally spaced decking surface. The decking panels are preferably supported from the beams in a manner shown and described in an early part of this description wherein each such panel has a pair of threaded bolts 403 received through holes in the overhanging, longitudinally extending sides of the panels to engage at their lower ends with the top of the support beam.
As also shown in FIG. 23A, and as more fully described heretofore, seal strips 404 anchored to the lower sides of the decking panels for extension longitudinally thereof so as to engage the upper side edges of the support beams. As previously described, these strips are urged against the side edges of the beams to close the outer ends of the spaces between the lower sides of the decking panels and the tops of the support beams, and concrete or grout is placed therein either prior to or during pouring of a deck slab over the tops of the decking panels. As also previously described, the bolts 403 may be extended or retracted in order to adjust the grades of the top surfaces of the decking panels prior to pouring of the slab. As will be described to follow, however, this aspect of the present invention also anticipates that the decking panels may be supported on the support beams by more conventional means, such as shown and described in connection with FIGS. 1 to 3 of this application.
The deck shown in FIG. 23 also comprises a plurality of reinforced concrete forming panels 405 having their longitudinally extending side edges disposed between the longitudinally extending sides of the support beams and their laterally extending sides with their tops beneath the bottoms of the laterally extending ends of the decking panels 402. Thus, the forming panels span the space between the ends of the support beams to provide, with the tops of the beams, one upper surface on which the slab may be poured to a greater depth than it is poured above the decking panels.
For this purpose, a pair of hangers 406 are mounted on the longitudinally extending sides of the forming panels with their outer ends extending beyond such sides and thus overhanging the adjacent sides of the support beams so as to support the forming panels therefrom. For this purpose, and as will be described more fully hereinafter, the embodiment of each such hanger 406 includes a beam 407 which is connected intermediate its ends to the forming panel on which it is mounted by threaded bolts 408 whose upper ends are received through the threaded holes in beam 407 intermediate its ends and whose lower ends are received within aligned holes in the forming panels near their longitudinal sides. When so connected to the decking panels, the inner ends of the beams 407 engage with the tops of the forming panels, while the outer ends are tilted upwardly to positions above the top of the sides of the support beams.
More particularly, each such hanger includes second bolts 409 which extend threadedly through the outer ends of the beams to engage at their lower ends with the tops of the support beams. Thus, the bolts 409 may be manipulated to cause the inner ends of the beams to act as a fulcrum as the hanger beam is tilted to raise or lower the tops of the forming panels with respect to the support beams. As a result, it is possible to adjust the top surfaces of the forming panels to a desired grade prior to pouring of this slab.
As best shown in FIGS. 23C and 23E, the top surfaces of the forming panels at the interior of the space are close to the bottom surfaces of the decking panels 402. However, as best down in FIGS. 33D and 33F, the top surfaces of the forming panels 405 which extend between the support beams 400B at the end of the beam are somewhat lower than those of adjacent decking panels and generally in horizontal alignment with the lowered support beam surfaces 401. As previously described, this permits the casting of a deeper and thus stronger slab at the ends of the span. The vertical spaces between the laterally extending ends of the decking panels 402 which overhang the laterally extending ends of the endmost decking panels 405 is closed by means of a strip 410 of fiberboard or other suitable material to prevent loss of concrete therebetween upon pouring of a slab over the decking panels and forming panel and the tops of the support beams.
In the construction of the reinforced concrete deck, the decking panels are first supported upon the support beams and their top surfaces are adjusted to a desired grade with respect to the finished deck by means of the bolts 403, as shown in FIG. 23A. Alternatively, the top surfaces of the decking panels may be brought to the desired grade in a manner described in connection with FIGS. 1 to 3, such as the disposal of longitudinally extending strips 411 within the space between the overhanging, longitudinally extending sides of the decking panels and the top surfaces of the sides of the support beams, as shown in FIGS. 24A and 24B.
The detailed illustrations in FIGS. 24A and 24B show reinforcing bars extending from the ends of the decking panels as well as metal loops having their free ends embedded in the top surfaces of the support panels and support beams, as well as the construction and arrangement of the hangers 406 supporting the forming panels from the support beams in the positions shown. These figures further show a broken away portion of a concrete slab 412 which has been poured in place above the tops of the decking and forming panels as well as the support beams. As previously described, these figures differ in that the panels and the ends of the support beams shown in FIG. 24A are disposed at interior portions of the deck span, while whose of FIG. 24B are disposed at the end of the span. As previously described, the lowered top surfaces 401 of the outer ends of the support beams and forming panels shown in FIG. 24B enable the slab to be poured to a greater depth than the interior portions thereof, thus providing the deck with the desired lateral strength in these areas.
The beam 407 of the form of the forming panel of hanger 406 shown in the above described figures, and in particular in FIGS. 24A and 24B, is shown in FIGS. 25 and 35A to comprise a pair of spaced channels 412 connected by a lateral bar 413 at their inner ends and at their outer ends and intermediate their inner and outer ends by thread formers consisting of wire nuts 414 and 415 welded or otherwise secured to the inner sides of the channels. As shown in FIG. 25, the upper end of bolt 408 is threaded into the wire nut 415 and bolt 409 is threaded through the wire nut 414. As also shown in this figure, the lower end of bolt 408 is threaded into a thread former 416 within a hole through the forming panel 405 near its side adjacent support beam 400A to mount the hanger beam 406 with its inner end bearing on the top of the panel and its outer end extending over the side of the panel and above the top of the side of the support beam. More particularly, the beam is so connected to the panel as to be tilted with respect to the top surface of the panel 405 so that, as previously described, the inner end of the beam acts as a fulcrum as the bolt 409 is adjusted vertically within the wire nut 414 to raise or lower the forming panel with respect to the support beam, and thus raise the top surface of the forming panel to the desired grade.
The alternative hanger shown in FIG. 36, and indicated in its entirety by reference character 406A, is basically similar to hanger 406. Thus, it includes a beam 407 A and a bolt 408A which is threaded at its lower end for connection with a thread the former 416A in forming panel 405 near its longitudinally extending side edge. In this way, the beam is mounted on the panel with its inner end bearing on the top of the panel and its outer end extending over the side of the panel and above the top of the support beam 400A near its adjacent side.
More particularly, a second threaded bolt 409A is received through a threaded hole in a thread former 414A at the outer end of the beam so as to engage at its lower end with the top of the support beam. Thus, the inner end of beam 407A acts as a fulcrum to permit the panel 405 to be raised or lowered by manipulation of bolt 409A.
Beam 407A differs from beam 407 in that it is molded as a one-piece, plastic body with bolt 408A and the threads 414A to receive bolt 409A formed integrally therein. More particularly, the body of the beam 407A is molded in the shape of an I-beam having tubular parts in which the threads are formed to receive the bolt.
In conclusion, therefore, it is seen that the present invention and the embodiments disclosed herein are well adapted to carry out the objectives and obtain the ends set forth at the outset as well as others inherent therein. Certain changes can be made in the method and apparatus without departing from the spirit and the scope of this invention. While there have been described various embodiments of the present invention, the methods and apparatus described are not intended to be understood as limiting the scope of the invention. It is realized that changes therein are possible and it is further intended that each element recited in any of the following claims and each combination of elements is to be understood as referring to all equivalent elements or combinations for accomplishing substantially the same results in substantially the same or equivalent manner. It is intended that the claims cover the invention broadly in whatever form its principles may be utilized.
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Concrete panels for making concrete decks or floors for spanning between structural supports; parts of such panels including shear connectors, thread formers, and resilient grout seals; tools for manipulating grout-seals; co-acting forms for making panels; interior and overhang panels and apparatuses and methods for fabricating and using such panels. The panels have a seal member device connected to a body member for sealing off a space between the panel and a structural support on which the panel rests.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to washing and drying apparatus and more particularly to a new and improved washer-dryer utilizing a single drum to provide both a washing and drying cycle in sequential operations. A compact unit is thereby provided.
2. Description of the Prior Art
The use of washing and drying apparatus is well known in the prior art. As may be appreciated, these devices in the past have required a substantial amount of space and as such, have been bulky devices requiring more room then is necessary with my improved invention. There have been attempts to develop washing and drying apparatus of more compact structure. One example is U.S. Pat. No. 2,793,518 to Geldhof where a washer and dryer performs in a single cabinet-like structure but in a stacked arrangement. The advantage of the Geldhof patent has been to utilized vertical space rather than horizontal space but as such, a duplication of parts and use of space has resulted. A further patent to Geldhof was issued in U.S. Pat. No. 2,834,121 as a somewhat improvement over the aforenoted Geldhof patent. An improved reorientation of motor and pump means as well as other mechanisms provided a somewhat more compact structure, but generally this patent continued the same shortcomings as the previous Geldhof patent in utilizing stacked chambers to provide a washer-dryer combination.
U.S. Pat. No. 3,514,330 to Schaap, et al., sets forth a multi-purpose kitchen unit wherein a sink overlies a dishwashing unit incorporating therewith a garbage disposal unit. This reference does tend to forward the teaching of multi-use single cabinet organizations, however, the single rotating drum for multiple washing and drying operations has accordingly eluded the prior art.
U.S. Pat. No. 3,986,891 to Rumbaugh sets forth a further multi-purpose kitchen appliance. Particularly a cooking and washing combination of unique interrelationship is set forth in somewhat the same vein as the Schaap patent setting forth the teaching of a multi-purpose appliance.
U.S. Pat. No. 4,207,683 to Horton sets forth a conventional-type clothes dryer with the addition, however, of providing a limited spray of water onto the clothes to provide for removal of wrinkles of particular fabrics. The teaching in this patent enables the use of a source for introduction of various liquid additives for use as clothes softening agents and the like and is a further step in enhancing the multi-purpose use of a clothes dryer.
U.S. Pat. No. 4,345,609 to Nishizawa provides an apparatus for the rinsing and drying of small glass tubes such as used in chemical analysis. A cage mounted in a cabinet-like vessel is provided with heating elements whereupon piped in water allows a rinse cycle and the drying elements provide subsequent drying of the contents positioned within the apparatus.
The problem, however, of providing a compact washer-dryer combination for a complete washing and drying operation upon clothes has not been addressed by the prior art. As such it may be appreciated that there is continuing need for new and improved washing and drying apparatus as applied to conventional clothing which addresses both the problem of storage and affectiveness and in this respect, the present invention substantially fulfills this need.
SUMMARY OF THE INVENTION
In view of the foregoing disadvantages inherent in the known types of washer-dryer apparatus now present in the prior art, the present invention provides an improved washer-dryer apparatus. As such, the general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new and improved washer-dryer apparatus which has all the advantages of the prior art washer-dryer apparatus and none of the disadvantages.
To attain this, the present invention comprises a washing and drying combination formed in a unitary cabinet-like structure whereupon a single drum is utilized to perform both the washing and drying function of the apparatus. A shielding mechanism is utilized to protect the heat transporting duct work associated with the drying function from liquid intrusion during the washing cycle and is repositionable outwardly of said duct work to enable a drying cycle to commence.
My invention resides not in any one of these features per se, but rather in the particular combination of all of them herein disclosed and claimed and it is distinguished from the prior art in this particular combination of all of its structures for the functions specified.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. Those skilled in the art will appreciated that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
It is therefore an object of the present invention to provide a new and improved washer-dryer apparatus which has all the advantages of the prior art washer-dryer apparatus and none of the disadvantages.
It is another object of the present invention to provide a new and improved washer-dryer which may be easily and efficiently manufactured and marketed.
It is a further object of the present invention to provide a new and improved washer-dryer apparatus which is of a durable and reliable construction.
An even further object of the present invention is to provide a new and improved washer-dryer apparatus which is susceptible of a low cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such washer-dryer apparatus economically available to the buying public.
Still yet another object of the present invention is to provide a new and improved washer-dryer apparatus which provides in the apparatuses and methods of the prior art some of the advantages thereof, while simultaneously overcoming some of the disadvantages normally associated therewith.
Still another object of the present invention is to provide a new and improved washer-dryer apparatus formed within a unitary cabinet-like structure.
Still another object of the present invention is to provide a new and improved washing and drying apparatus wherein a single drum member is utilized to perform both the washing and drying cycle of the invention.
A still further object of the present invention is to provide a new and improved washer-dryer apparatus utilizing 110 AC voltage to drive the motor mechanisms of the apparatus and deriving 220 AC voltage to provide power to the heating elements of my invention, all of which are housed in a single, cabinet-like structure.
These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
FIG. 1 is an isometric view of my invention in partial cutaway section to provide illustration of the internal components, their configuration and relationship.
FIG. 2 is an orthographic view of my invention taken along lines 2--2 of FIG. 1 in the direction indicated by the arrows.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the drawings, and in particular to FIG. 1 thereof, a new and improved washer-dryer apparatus embodying the principals and concepts of the present invention and generally designated by the reference numeral 10 will be described.
More specifically, it will be noted that the washer-dryer combination sets forth a conventional cabinet-like structure housing essential components of my invention. A forward face 11 is supported thereon with an access door 12 secured by a latch member 13 to a forward face 11 and pivotal about hinge members 14 for gaining access to the interior of the combination washer-dryer drum structure. It is contemplated that separate controls, as typically indicated by washer control buttons 15 and dryer control buttons 16, be positioned for control of the respective functions of my device and the respective washer and dryer control buttons be separated in a manner as to be non-confusing to a user.
With further reference to FIG. 1, it will be noted that a stationary drum 17 is positioned somewhat centrally of the invention 10. Drum 17 has, in sliding relationship thereto, a baffle plate member 18 mounted circumferentially of drum 17 for circumferential reciprocation in the direction of arrow 19 for whose purpose will be described below. Positioned in overlying relationship to drum 17 is an air plenum member 20 with heat supply ducts 21 providing the heated drying air required for the drying function of my invention. Of conventional construction is a vent duct 22 for the normal venting of such drying air, as expended during the drying cycle.
A fluid pump 23 is securedly located upon on the floor portion of my invention with conventional hot water and cold water conduits 24 and 25 respectively providing necessary water to the wash cycle of my invention with an appropriate supply channel 26 to provide a mixture of the input water into the inner rotatable drum of my invention set forth as element 28 in a manner well known in the art of washing machines. Electrical drive motor 27 is positioned for driving of the inner rotatable drum member 28 in a controlled manner dependent upon the need for a wash or dry cycle. Integrally mounted within rotatable drum 28 are agitator fins 29 for the control movement of garments within drum 28.
Gaining access to my invention rearwardly of my apparatus 10 is a provision for plural voltage supply lines. Supply line 30 is a conventional 110 AC volt supply line for normal operation of the motor and its function during a wash cycle. Supply line 31 is a 220 volt supply line utilized should the dryer be constructed as an electrical dryer with the use of electrical resistance heating elements which would be positionable within supply ducts 21 for convenience but may be positionable in any portion of a supply conduit of the heat supply assembly. My washer-dryer apparatus may, of course, utilize natural gas for drying whereupon in lieu of a 220 volt supply line for supplying energy to a heating assembly, gas flame porting would be positioned within the aforenoted drying assembly. An electrical control box 32 may house all of the requisite electrical circuitry which is of conventional configuration well known in the art and accordingly further detail is not deemed necessary.
Reciprocation of baffle 18 in a direction as indicated by arrow 19 effected by manipulated use of handle 33 displaceable in an arcuate path within arcuate slot 34 positioned for convenience through forward face 11 of my apparatus. When a wash cycle of my invention is utilized handle 33 is grasped and manipulated in a clock-wise manner to thereby seal plenum member 20 from the action of fluid within rotatable drum 28. Upon use of a drying cycle of my invention, baffle 18 may be manipulated in a counter clockwise manner to thereby open plenum 28 and provide thereby heated air to interior of rotatable drum 28 when performing its function as a dryer. An alternative to the use of baffle 18 would involve alternate structure, such as the employment of vanes 35 illustrated in phantom in FIG. 2. The vanes 35 would function as not only directional elements for uniform distribution of heated air within rotatable drum 28 during its drying cycle, but would further deflect water during a wash cycle occuring within drum 28 and prevent excess washing liquid from intruding within plenum 20.
As to the manner of usage and operation of the present invention, the same should be apparent from the above description. Accordingly, no further discussion relative to the manner of usage and operation will be provided.
With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
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A compact washer-dryer apparatus wherein a washing and drying cycle typically performed on clothes is set forth utilizing a common rotating drum for each operation. Directed drying air is provided to the common drum by means of an overlying plenum chamber. Subsequent to a washing cycle, a pivoting shielding plate is repositioned whereupon the drying cycle may commence in the common drum utilized for the washing cycle.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. application Ser. No. 11/502,084, entitled “Propulsion and Steering Mechanism for an Underwater Vehicle”, filed Aug. 10, 2006, now U.S. Pat. No. 7,540,255 B2, which claims priority to provisional patent application Ser. No. 60/710,552, filed Aug. 23, 2005, the entirety of both are incorporated herein by reference.
FIELD OF THE INVENTION
This invention is directed to a remotely operated underwater vehicle, and more particularly to a Remote Operated Vehicle (ROV) tether and the transmission of video signals and power on the tether.
BACKGROUND OF THE INVENTION
Inspection class Remote Operated Vehicles (ROVs) are typically used to position a video camera underwater. The ROV usually contains electronics that are connected to a base station by a wire tether. Motor driven propellers called thrusters are used to move the ROV.
Current ROVs, for example as described in U.S. Pat. No. 6,662,742, generally use separate thrusters to control motion in the horizontal and vertical planes. For example, a pair of thrusters mounted horizontally on the sides of the ROV can move the ROV forwards, backwards and control azimuth, while another thruster mounted vertically can move the ROV up and down.
Since motors are generally heavy, this configuration is not optimally efficient. When the ROV is moving in the horizontal plane, the vertical thruster is essentially dead weight, so that the power to weight ratio is diminished. The situation is typically worse when moving vertically because the multiple horizontal thrusters that are idle reduce the efficiency even further.
Another problem with ROVs relates to the electronics. Control circuitry, which is generally not waterproof, is often housed in a watertight box. This allows for access to perform reprogramming of the electronics, but causes a problem because opening and resealing the watertight enclosure may be time consuming.
A solution to this problem may be to run the reprogramming signals through the tether, but this has the disadvantage of adding to the size, weight and cost of the tether.
Also, it may be desirable to encapsulate the electronics in epoxy, eliminating the need for a watertight enclosure for the electronics. This solution has not typically been employed in past ROVs because once encapsulated, either the electronics cannot be reprogrammed, or as mentioned above the reprogramming wires must be run through the tether.
Another problem with existing ROVs is that in general an expensive tether is required. This is because the tether typically contains power wires, control wires and video cable. Since video is usually a coaxial cable and the power and control signals are not, the tether must contain both standard unshielded wires for power and control and shielded coaxial cable for the composite video.
A standard solution is to use a custom cable for the tether, but this adds to the cost of the ROV. Another solution heretofore employed is to put batteries in the ROV eliminating the need to run power through the tether. This allows a single coaxial cable to be used for the tether, carrying modulated video and control signals. The problem with this method is that the batteries add weight to the ROV and the modulation circuitry can be expensive.
A need therefore exists for a propulsion system for an ROV that improves the power to weight ratio while allowing motion in both the horizontal and vertical planes. The electronics should be reprogrammable without requiring a watertight box or additional reprogramming wires in the tether, and the tether should supply video to the base station without requiring coaxial wires.
BRIEF SUMMARY OF THE INVENTION
This invention is directed to a method of propulsion for an underwater vehicle. Two propellers are independently driven by motors, while the orientation of the propellers is simultaneously controlled by a third motor. A means is provided for reprogramming the control electronics that can be disabled when the vehicle is underwater. The control electronics also provides that all signals including video are transmitted to a base station without requiring coaxial cable.
This invention uses two horizontally opposed propellers, which can be rotated into the horizontal or vertical planes, to drive the ROV. The control electronics includes an electrically isolatable programming port that allows the electronics to be reprogrammed. All signal including video are run through standard category 5 network cable (Cat5 cable), reducing weight and cost.
For the preferred embodiment, a separate motor drives each propeller and a single servo motor controls the orientation (horizontal, vertical or in between) of the propellers. To move in the horizontal plane, the motors can drive the ROV forward and backward by changing the direction of rotation of the propellers. Turning can be accomplished by varying the relative speed of the motors, and rotation about a point can be accomplished by running the propellers so as to create thrust in opposite directions.
To move the ROV up and down, the servo rotates the propellers to the vertical orientation. The direction of the propellers then controls whether the ROV moves up or down, and the relative speed of the propellers controls the roll of the ROV. In addition, the servo motor can position the propellers in between the horizontal and vertical planes, to provide a motion that combines both horizontal and vertical components. When operating in this manner, the floatation at the top of the ROV provides stability and reduces any tendency for unwanted roll.
The electronics provides a programming port that is exposed to the water. Two pins on the port are used to electrically isolate the port from the programming bus. In this manner, when being operated in the water, the pins can be shorted together by a shorting block and the programming port will be unaffected by any conductive effect of the water.
However, when the unit is on dry land and reprogramming is desired, the shorting block can be removed and the electronics can be connected to a reprogramming device by the programming port.
The camera is connected to the tether through a video balun, which converts the 75-ohm composite video, ordinarily requiring coaxial cable, to 100 ohm balanced signal compatible with standard low cost Cat5 cable. Additional pairs of the Cat5 cable are used for power, ground and control signals. In the base station, a second balun can be used to convert the video signal back into composite video if desired for recording, display or digitizing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic illustration of a system constructed in accordance with the principals of the present invention;
FIG. 2 is a diagrammatic right side perspective view of an underwater vehicle of the system of FIG. 1 ;
FIG. 3 is a diagrammatic left side perspective view of the underwater vehicle of FIG. 2 ;
FIG. 4 is a simplified diagrammatic horizontal cross section of the drive and propulsion system;
FIG. 5 is a simplified schematic view of the rotation mechanism;
FIG. 6 is a schematic view of the system of FIG. 1 ;
FIG. 7 is a detailed schematic of a programming port of the system of FIG. 1 ;
FIG. 8A is a diagrammatic perspective view of the underwater vehicle showing the propellers disposed in a horizontal orientation;
FIG. 8B is a diagrammatic perspective view of the underwater vehicle showing the propellers disposed in a generally 45-degree orientation; and
FIG. 8C is a diagrammatic perspective view of the underwater vehicle showing the propellers disposed in a generally vertical orientation.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an illustration of the system, including Remote Operated Vehicle ROV 10 connected to base station 80 by tether 14 . The output of ROV video camera 12 is displayed in real time on the screen of the laptop 82 , and the joystick 84 is used to control the movement of the ROV 10 .
FIG. 2 shows a perspective view of the right side of ROV 10 . The main components of ROV 10 are video camera 12 , a right side thruster consisting of a drive motor 20 linked to propeller 46 through rotatable arm 40 , a left side thruster consisting of drive motor 50 linked to propeller 66 through rotatable arm 60 , and servo 70 to simultaneously rotate the arms 40 and 60 .
Case 16 provides the attachment points for camera 12 , drive motors 20 and 50 , drive arms 40 and 60 , servo 70 , floatation 90 and control electronics 100 . Floatation 90 counterbalances the weight of the ROV to provide approximately neutral buoyancy. For shallow operation, a block of closed cell foam can be used. For deeper operation, the foam can be covered in a solid outer shell such as fiberglass, or a sealed container or other hard buoyant object can be used for floatation.
Right arm gear 42 is connected to right arm 40 , and the corresponding left arm gear 62 is connected to left arm 60 . Servo gear 72 is connected to servo 70 , and drives right idler gear 44 , which also connects to rotation shaft 74 . Shaft 74 also connects to left idler gear 64 , shown in left perspective view FIG. 3 . When servo 70 turns servo gear 72 , right idler gear 44 rotates right arm 40 and also rotates rotation shaft 74 and left idler gear 64 , which rotates left arm 60 . In this fashion servo 70 controls the orientation of both right arm 40 and left arm 60 simultaneously.
FIG. 4 shows a cutaway view of the motor drive system. Drive motor 20 is offset from case 16 centerline 18 in order to avoid interference between right motor bevel gear 24 and left drive bevel gear 26 . Similarly, drive motor 50 is offset from centerline 18 in order to avoid interference between left motor bevel gear 24 and right drive bevel gear 26 . The offset is exaggerated in FIG. 4 for the sake of clarity.
In the preferred embodiment, drive motor 20 is housed in a watertight housing and protected from water ingress by shaft seal 22 . Shaft seal 22 can be a simple lip seal for shallow water operation, or a higher performance seal for deep water use. Alternatively, a magnetic coupling could be used to isolate the motor from the seawater. Locating drive motor 20 in a watertight housing has some of advantages. First, there is no need to make case 16 waterproof because the gearing and shafts it contains can be made from materials compatible with submersible use. Second, the motor then becomes an easily replaceable part, allowing for standard motors to be replaced with higher performance motors for greater operating speed or operation at a greater depth.
In the preferred embodiment, drive motor 20 connects to motor bevel gear 24 that drives right drive bevel gear 26 . Right drive bevel gear 26 connects to right drive shaft 30 , which is supported by right shaft bearings 38 . Drive shaft 30 is concentric with right arm 40 . This allows right propeller 46 to be turned by motor 20 independently of the rotation of right arm 40 . Drive shaft 30 is supported by sleeve bearing 38 , which may for example be a flange mounted sleeve bearing.
The distal end of right drive shaft 30 connects to right end bevel gear 32 that drives right propeller bevel gear 34 . Right propeller bevel gear 34 connects to right propeller shaft 36 and drives right propeller 46 . The left side drive system is symmetrical to the right side drive system, with drive motor 50 connected to motor bevel gear 24 which drives left drive bevel gear 26 . Left drive bevel gear 26 connects to left drive shaft 30 , which is supported by left shaft bearings 38 . For the preferred embodiment, right propeller 46 is a right hand propeller and left propeller 66 is a left hand propeller, i.e. right propeller 46 provides forward thrust when turning clockwise, and the left propeller 66 provides forward thrust when turning counterclockwise. This provides a balancing effect and prevents the direction of rotation of the propellers from inducing a rotational force to the ROV 10 .
FIG. 5 is a cutaway view of the servo driven rotation mechanism. For the preferred embodiment, servo 70 is a servo motor housed in a watertight housing. Since servo 70 typically moves with a range of plus or minus 90 degrees from the neutral horizontal position, a rotating shaft seal is not required and a low cost latex bellows can be used to seal the gear to the housing.
When servo 70 is driven clockwise when viewed from the right, it drives servo gear 72 clockwise. Servo gear 72 drives both idler gears by directly driving right idler gear 44 and indirectly driving left idler gear 64 which is connected to right idler gear 44 by rotation shaft 74 . The rotation of the idler gears will be opposite that of the servo, so that when the servo is driven clockwise, both idler gears will turn counterclockwise.
Each idler gear in turn drives the associated arm gear; right idler gear 44 drives right arm gear 42 , and left idler gear 64 drives left arm gear 62 . Counterclockwise motion of the idler gears causes clockwise motion of the arm gears, with the net effect being that when the servo 70 moves clockwise both arms move clockwise.
FIG. 6 shows a block diagram of the electrical connections of the system. There are two major electrical components: base station 80 and control electronics 100 located in ROV 10 . Base station 80 consists of a processing unit such as laptop PC 82 , power supply 88 , and joystick 84 to control the motion of ROV 10 .
Control electronics 100 contains microprocessor 104 , which is typically a low cost 8-bit microprocessor. Sensors 108 are connected to microprocessor 104 . A variety of sensors can be used, typically consisting of an accelerometer to provide roll and pitch, an electronic compass to provide heading, and a depth sensor. Microprocessor 104 is also connected to pulse width modulator (PWM) circuits 106 for drive motors 20 and 50 . PWM circuits 106 are used to independently control the speed and direction of each drive motor.
In the preferred embodiment, all signals between base station 80 and the control electronics 100 are run through 100 feet of standard Cat5 cable, which contains four twisted pairs of 24 gauge wire. Two pairs are used to carry power from base station 80 to ROV 10 . Another pair of wires is allocated to the control signals, with one wire for transmit and one wire for receive. Any appropriate electrical interface may be used for the control signals; in the preferred embodiment, RS-232 serial interface is used to send data to and from the ROV. The final pair of wires in tether 14 is used to carry video.
In base station 80 , the two pairs dedicated to power are connected to power supply 88 . For example, power supply 88 may generate 24 volts DC. One pair of wires is connected to +24 volts and one pair of wires is connected to ground. The pair of wires allocated to control signal is connected to the serial port of laptop 82 . The pair of wires for video is connected to balun 86 .
In control electronics 100 in ROV 10 , the pair of wires for power is connected directly to PWM circuits 106 , and is also used to supply power to the rest of the circuitry in control electronics 100 and to camera 12 . In the preferred embodiment, control circuitry 100 requires 3.3 volts, and camera 12 requires 12 volts, so voltage regulators are used to convert the 24 volts from power supply 88 into the appropriated level as required. The control electronics may also contain a programming port connected to microprocessor 104 through an analog switch 110 . The switch can be disabled by shorting together two pins on programming connector 112 , allowing the connector to be isolated from the microprocessor.
FIG. 7 shows a detailed schematic of the programming port. In the preferred embodiment, programming connector 112 is a 10 pin connector used to connect to the JTAG programming port on microprocessor 104 . Programming connector 112 is positioned on the outside of ROV 10 , where it will come in contact with sea water which has conductive properties. Analog switch 110 is connected in between microprocessor 104 and programming connector 112 . Pin 9 of programming connector 112 is used to enable or disable the programming port. When pin 9 is unconnected, resistor 114 pulls up the enable input of analog switch 110 , enabling the switch and allowing microprocessor 104 to be reprogrammed. When pin 9 is connected to pin 10 , for example by a shorting block, jumper, or similar connection, the enable input of analog switch 110 will be a zero potential disabling the programming port. With the jumper in place, programming connector 112 is effectively disconnected from microprocessor 104 .
During normal operation, output of camera 12 is shown in real time on screen of laptop 82 . Laptop 82 also displays output of sensors 108 (for example roll, pitch, and yaw) and may also display any other pertinent local information such as time, date and GPS coordinates. Laptop 82 may also save video, sensor and local data on its hard drive, CD or DVD storage. In addition, video may also be saved on an external VCR or other recording device, not shown.
The base station uses a command structure to encode the desired speed and direction for the drive motors 20 and 50 , and the desired rotation for servo motor 90 . Base station 80 also periodically polls the ROV 10 to determine the current status of sensors 108 . Since output of the sensors may be relevant information used in piloting the ROV 10 , base station 80 may poll sensor 108 status many times a second, so that base station 80 can display current sensor data in real time.
Joystick 84 is used to pilot the ROV 10 so as to position ROV 10 in order to capture the desired information on video. For the preferred embodiment, a 3D joystick is used. Forward and backward motion of the joystick 84 is used to control the angle of rotation of the propellers, with the neutral position of joystick 84 corresponding to a horizontal orientation of the propellers. Depth of the ROV 10 is controlled as follows: pushing the joystick forward will cause the ROV 10 to descend, and pulling the joystick back causes the ROV 10 to move toward the surface.
FIGS. 8A to 8C show the propeller position corresponding to the position of joystick 84 . FIG. 8A corresponds to the neutral position of joystick 84 , and ROV 10 will move forward horizontally when thrust is applied. FIG. 8B corresponds to joystick 84 being pushed forward approximately 50%; this will cause ROV 10 to descend at about a 45 degree angle when forward thrust is applied. FIG. 8C corresponds to joystick 84 being pushed all the way forward and ROV 10 will descend vertically when thrust is applied.
Joystick 84 also has a throttle lever, which moves between off (no thrust) and on (full thrust). Laptop 82 in turn sends commands to ROV 10 to control the voltage applied to the drive motors 20 and 50 using the PWM controllers in the ROV control electronics 100 .
Azimuth of the ROV 10 is controlled by joystick 84 in two ways: when throttle is on, relative power to the drive motors is modified according to the side to side position of joystick 84 . The neutral (centered) position corresponds to equal power to the drive motors; joystick 84 moved to the right corresponds to increased power to the left drive motor 50 , and joystick 84 moved to the left corresponds to increased power to right drive motor 20 . In this manner the operator may move joystick 84 right to go right and move joystick 84 left to go left.
Another way to control azimuth by joystick 84 is by twisting the joystick. When laptop 82 detects clockwise twist of joystick 84 , forward thrust is generated on left drive motor 50 and reverse thrust is generated with right drive motor 20 . This caused the ROV 10 to pivot in place, allowing camera 12 to be panned to the right. The speed of the motion is proportional to the amount of rotation of joystick 84 . A symmetrical but opposite motion is generated when joystick 84 is twisted to the left; i.e. camera 12 is panned to the left.
One potential limitation of the preferred embodiment may be the cost of laptop 82 . This could be ameliorated by using a custom display to show output of camera 12 and additional custom electronics in the base station to replace the functionality of the laptop in interfacing joystick 84 to tether 14 .
Regarding attachment of drive motor 20 and 50 to case 16 , the drive motors could be attached perpendicular to centerline 18 . This would allow motor bevel gears 24 to be replaced with pinion gears, and drive bevel gears to be replaced with spur gears, potentially providing a wider range of available gear ratios and lower cost.
Regarding the placement of the motor shaft seals 22 , case 16 could be made waterproof and motor shaft seals 22 could be moved into the drive arms. This would allow the servo 70 and control electronics 100 to be moved inside case 16 , and would reduce the size of floatation 90 by reducing the submerged weight of case 16 .
Power supply 88 is describes as a 24 volt supply for the preferred embodiment. However, other voltages could be used and may be advantageous in certain circumstances. For example, if tether 14 were longer that the 100 feet of the preferred embodiment, it may be desirable to used a higher voltage to reduce the necessary current and thus lower the voltage drop across the cable.
While the instant invention has been shown and described herein in what are conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of the invention, which is therefore not to be limited to the details disclosed herein, but is to be afforded the full scope of the claims so as to embrace any and all equivalent apparatus and articles.
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A remotely operated underwater vehicle includes a case to which is attached a camera for transmitting video to a remotely located base station. A tether having four pairs of twisted wire operably connects the underwater vehicle, and the camera to the base station. Video is transmitted from the camera to the base station on a pair of twisted wire.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to the field of books, particularly children's books and to the protection of children's books from chewing during the teething stage for infants or orally active children.
[0003] 2. Background of the Art
[0004] During the first 18 months the average child begins teething, develops sensory discrimination, and begins to walk and talk. Children usually begin teething with the emergence of the two bottom front teeth, followed about four to eight weeks later by the four upper teeth, and then about one month later by the two lower incisors. The first molars come in next, followed by the canine or eye teeth. Parents and caregivers are encouraged to soothe the child at this stage by gently rubbing or massaging the child's gums with a finger. Teething rings are helpful as well, and are preferably made from a firm material such as rubber. During this stage, children chew on nearly anything that will fit into their mouth to relieve the irritation in their gums. Some children develop an intense oral satisfaction during this stage, and they continue to chew objects further into their life.
[0005] The U.S. Department of Education and many other authorities encourage parents to read to children, beginning at a very early age. With the help of their parents and other caregivers, children can begin a lifelong relationship with the printed word, so they grow into adults who read easily and frequently whether for business, knowledge, or pleasure.
[0006] Children develop a fondness for the pleasure associated with the reading experience, including the books themselves. After reading a book to a baby or toddler prior to bedtime, the baby often at this point is inclined to grab the book that the parent was reading and want to bring it with her or him. Children often seek out books on their own to play with. Standard books that are made out of paper and cardboard are not safe to give to a baby or toddler, or at least the books may become readily damaged by the child chewing on them. As babies are teething, they will often place any handy object in their mouths. Paper books may become torn, or may cause a choking hazard.
[0007] There are many products on the market that are designed to encourage a love for books in young children and there are many separate items used for pacifying children by allowing them to chew or suck on the object. Given the importance of early childhood development to society and individual children alike, though, the development of new ideas and products in this area is to be encouraged. In particular, a need exists for such products that are safer for infants and toddlers than conventional books, and that are not likely to present a choking hazard.
[0008] Published Patent Application 20050245968 describes a teething toy for infants and small children that is styled as an illustrated book. The toy includes a number of page-like leaves, which in the preferred embodiment are fabricated from a cloth-like material, and a number of attached teething elements. The teething elements are preferably made from a relatively hard resilient material that is textured to provide effective teething relief. In one embodiment, the teething elements are integrated into artwork that is printed on the attached page leaf. The teething toy combines effective teething relief for an infant or small child with subtle encouragement to the child that books are worthwhile objects of attention.
[0009] Alternative and improved products are still desired in this market.
SUMMARY OF THE INVENTION
[0010] The present invention relates to a replaceable article that can be inserted and removed from the binding or backing of a children's book and which can be chewed on without damage to the book or injury to the child. The device can adhere to and slide onto the binder and extend away from the book to provide an attracting appearance. The article may be replaced or partially replaced and the size of the device avoids any significant issue of potential choking for the child.
[0011] The device may be described as for connection to a book binding of a children's book, the device and having:
[0012] a tear-resistant chewable body; and
[0013] a connector attached to the chewable body;
[0000] the connector securing the chewable body to the book binder.
BRIEF DESCRIPTION OF THE FIGURES
[0014] FIG. 1 shows an article according to practices of the invention that may be inserted into the binding of a children's book and subsequently removed without damage to the book. A book binder is also shown in position to accept the article of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Books of any significant quality are usually constructed with pages, two rigid faces enclosing the pages to protect the pages, and a binding or back that secures the pages between the faces. Children that are teething or orally active are most likely to attempt to chew the most prominent pieces on the books, which will usually be the corners and edges of the book. A device is provided according to the present teachings that can be inserted onto a book, provide a more prominent and easily acceptable appearance and position than the pages and face and back, and be chewable by a child without harm to the child or damage to the book.
[0016] The device comprises a chewable body, preferably in the image of a character, animal or shape and an insert connector on the body that can be inserted into the receptor that adheres or securedly fits onto the binding of a book to temporarily secure the chewable body to the outside of the binding in a position that extends away from the book and is accessible by a child for teething or chewing. The term chewable excludes materials that has nutritional content and is to be eaten, such as taffy, gum, licorice and the like, as the chewable body is not intended to be swallowed or ingested, even though some incidental ingestion may occur. The chewable body is intended to be resistant to maceration and swallowing. The device can be designed with specific images and shapes and characters on the extending portion, and it will be referred to often herein as a “bookworm,” as one convenient shape for the attractive chewable end of the device is as a worm, with a face molded or printed thereon.
[0017] The device should be made of a tough, tear-resistant rubbery or elastomeric material, and should also be free of phthalates, which have potentially significant health issues, especially when ingested. Materials such as polyurethanes, acrylic elastomers, silicone elastomers, natural rubbers (which are hardened to make them more tear-resistant) and other synthetic materials may be used. The colors and imagery (e.g., eyes, mouth, nose, hair, even limbs, and the like) are preferably molded into the device, although certain paints may be used if they are chemically safe. Chewing on painted surfaces will eventually remove the paint, and that is undesirable. Molding image content into the body of the device is a well understood process and by using a single mold shape (e.g., tube-like, elongated oval, cylinder with rounded end(s), and the like, a few mold shapes may be used with many different characters by injecting the image content into the mold, with part of the elastomer being transparent or translucent to allow the image shape and colors to be viewed through the surface of the shape. The attaching element (the portion of the device that connects with the binder in the book) can be attached during the molding process or after the molding process by conventional molding techniques. A pocket may also be molded into the body and the attaching element snapped or fitted securely (or adhered) into the pocket.
[0018] If the bookshelves of most infants and toddlers are checked, the children's books will be found to have holes in the bindings of their board books, the result of chewing and gumming the bindings as a favorite pastime in the infants' first two years. Bookworm™ protectors is an accessory product for the infant/toddler market designed to protect the binders of board books yet still enable infants to satisfy their desire to chew during this phase of their development and even enhance their enjoyment of the books. The product's benefits are three-fold:
1) protects the child from ingesting undesirable and unsanitary elements, including ink, from the book cover; 2) protects and preserves the integrity of the board book; and 3) functions as a safe teether and a distraction from less desirable teething options, including the book's binder.
Bookworm will be made in a phthalate-free plastic. Viewing the Figures attached hereto will assist in a better understanding of the practice of the present technology.
[0022] Referring now to the drawings, wherein like reference numerals designate corresponding structure throughout the views, and referring in particular to FIG. 1 , a teething device 2 according to a preferred embodiment of the invention includes a molded or shaped body 4 , a head 6 molded features 8 on the head 6 , molded limbs 10 and a slide, glide or groove 12 to connect with a book binding 14 . A benefit of the molded features, such as 8 is that the features can be pigmented (and need not be painted) and the feature is an integral part of the head 6 and will not be readily removed by chewing. The arms 10 are shown here, but may be optional or less prominent. The head may also be less prominent and merely be a colored portion of a uniform cylinder with ends containing the image of the face, tail, arms, legs, etc.
[0023] The groove 12 shown in FIG. 1 is essentially a female fitting for accepting the male insertion of the binding 14 into the groove 12 . The connection may be alternatively provided by having the hole 18 in the binding receive a male element (e.g., like a flattened pen holder clip [not shown], or slide as provided on garage door openers to fit over the adjustable light shields, flaps or blinders provided in cars. The male connectors on the device (hereinafter referred to as an insert clip) may be molded into the body 4 of the device 2 or may be snapped into the existing groove 12 or similar pocket in the body 4 . The insert clip or groove 12 may be a more rigid plastic, metal, composite or the like. If there is a neck portion 22 on the device 2 , the neck portion 22 should be relatively thick or the head 6 nearly directly attached to the body 4 so that the head is not easily removed. A large head is relatively desirable to provide dimensions for the area of the device that is likely to be chewed to provide elements of a size that could not cause choking, even if placed in the mouth. It is also possible to have any extensions on the device (head, limbs, ears, etc.) be highly porous so that even if lodged in the mouth or throat of a child, air can pass through the extensions.
[0024] As a device is chewed up or approaches a point of damage where pieces my begin to fall off or could fall off, the device can be replaced on a book with a new device, and the book remains undamaged. As shown in FIG. 1 , the faces 16 of the book are divided by the binding 14 and the (device 2 of the invention can be readily slid into or receive the natural opening 18 ) the male connector adheres to the binder of the book with a non-toxic adhesive of the binder 14 . The book will be folded along its natural fold lines 20 a and 20 b and the device will not interfere with the reading of the book.
[0025] The bodies of the devices are soft and compressible for the safety, comfort and enjoyment of the infant or small child. In one embodiment, the device may have a foam core (e.g., fabricated from a polyester foam filling) with a tear-resistant coating, such as an elastomer. The head may be securable to the body (e.g., by a male-female screw and threaded receptor connector, snap fittings, adhesive, or the like) rather than being molded as a single unit. In this manner, when the head wears out, only the head need be replaced on the device.
[0026] The device and method aspects of the technology described herein may be generally described as follows. A device is provided for connection to a book binding of a children's book. The device has: a tear-resistant chewable body; and a connector attached to the chewable body; the connector having a groove therein acting as a female receptor; and a male connector that attaches directly to the binder of the book with a non-toxic adhesive. The tear-resistant chewable body may be comprised of a natural or synthetic polymer. The polymer should be free of phthalates. The connector may have a groove therein to receive a children's book binding as a female receptor and the body may have an image or shape of an animal or character molded therein. (The surface of the device should be entirely free of paint, or optionally have a non-toxic, lead-free paint. At least 15 percent by length of the device may extend above the female receptor or insert clip, so that when attached to a book binding, the at least 15% extends beyond limits of height of the book.
[0027] A method is described for protecting a children's book against damage from chewing. This may be done by providing a children's book having a binding. Two piece installation may also be used, as by adhering the rubber with attached male connector to the binding of a book with non-toxic adhesive and sliding the tear-resistant chewable device with female receptor onto the male connector. Securing a tear-resistant chewable device to the book binding so that a portion of the tear-resistant chewable device extends away from the book to facilitate chewing. The portion of the tear-resistant chewable device that extends away from the book should extend lengthwise beyond at least one end of the binding. The at least 15% of the tear-resistant chewable device should extend beyond limits of height of the book. The method may have a set of steps where the device comprises a body having a groove therein to receive a children's book binding as a female receptor. The body has an image or shape of an animal or character molded therein. The device may also be applied as a two-piece device and two-step installation, with the chewable end attached after a first part is secured to the binding. Securing the device to the binding is more secure than merely attaching the chewable device to a face or page, as those attachments would tend to be less secure.
[0028] It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
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A replaceable article can be secured to and removed from the binding or backing of a children's book. The device can be chewed on without damage to the book or injury to the child. The device can slide onto the binding area and extend away from the book to provide an attracting appearance. The article may be replaced or partially replaced and the size of the device avoids any significant issue of potential choking for the child.
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BACKGROUND OF INVENTION
1. Field of the Invention
The present invention is directed to the field of electrical connector contacts or terminals and connector assemblies and in particular of the type having contact forces caused by torsional loading of the contact terminals.
2. Description of the Prior Art
The contact forces between the components of a mating pair of electrical connectors is of paramount importance in forming a reliable connection. This contact force is usually derived from the elastic characteristics of either or both of the connector terminal members.
Many contact designs utilize the principle of bending one or more terminal fingers that are configured as cantilevered beams. The bending forces give rise to a contact force between the terminals. Relatively high flexure of the beam is required to assure sufficient force thereby resulting in high bending stresses. This construction, along with the clearance needed to accommodate the flexing of the contact, precludes close contact spacing in a multi-contact assembly having high density connectors or multiple connectors in a confined space. With the continuing trend toward miniaturization, it becomes difficult and expensive to manufacture flexing beam systems that give satisfactory performance.
Terminals have been designed that develop torsional loads for creating contact forces between connector terminals. Torsional loading by means of rotation of a terminal about its own longitudinal axis allows for a compact design. Some prior art devices that teach this type of construction include U.S. Pat. No. 4,941,853 to Harwath; U.S. Pat. No. 4,105,277 to Jacobs; U.S. Pat. No. 2,924,807 to Field; and U.S. Pat. No. 4,735,588 to Bird et al. None of these devices discloses a construction where the socket or female member of the contact pair deforms. It is rather the pin or male member that is forced into conformance with the socket and as a result insertion forces are frequently unacceptably high with a consequent low cycle life because of degradation of the contact surfaces.
SUMMARY OF THE INVENTION
The present invention overcomes the limitations of the prior art. It is the principle object of this invention to provide an electrical connector assembly capable of maintaining sufficient contact forces for achieving low electrical resistance while maintaining contact integrity under severe shock and vibration environments and repeated connection and disconnection.
A further object of the invention is to have the contact forces uniformly distributed along the mating length of the socket material.
A still further object is to provide pairs of terminals that can be positioned at close center distance between rows and columns with respect to an adjacent pair mounted in an insulator housing thereby forming a multi-pin high density connector.
A still further object is to provide a socket or female terminal connectable with the pin of an existing connector, header or pin field of a printed circuit board.
These and other objects are achieved by the preferred embodiment of the present disclosure which comprises an elongated pin or male terminal member having a cross-section configured as a multisurfaced polygon, but preferably a square, that is to be inserted into a socket or female terminal member to complete an electrical circuit. While the pin is a solid member having straight and planar surfaces, the socket is fashioned by bending thin sheet metal into an interrupted hollow tube to form a passageway, the interior of which is congruent to the polygonal shape of the pin and receivable of the pin for its full length thereby defining a mating length where the pin and socket are overlapping.
The passageway is not a straight tunnel but rather a progressively rotated or twisted shape where each adjacent section is angularly skewed from the previous section thereby forming a helix having its axis coincident with the longitudinal axis of the passageway. Furthermore, one of the walls making up the passageway is slit longitudinally for the full mating length.
In another embodiment, the passageway is straight with parallel planar walls and the pin member is progressively angularly skewed, but in either embodiment, the cross-section of the passageway has a gradual and continuous angular orientation differing from that of the pin. When the pin and socket are mated, cooperating portions of each cross-section are in contact and complete an electrical circuit therethrough.
Insertion of the pin into the socket forces the socket to counter-rotate or untwist from its helical configuration to match the constancy of the pin since the pin is formed from a more rigid solid cross-section of metal while the socket is formed from thin sheet metal. This torsional loading is uniformly distributed along the length of the socket and with proper design, would be fully contained within the socket and pin and having no external torsional forces beyond the limits of the mating length of the coupled assembly. In order to limit the torsional resistance of the socket to the pin, one surface of the passageway is slit. This slit which may have the adjacent edges in contact or have a finite gap there between, allows the passageway to conform to the pin cross-section while untwisting since a closed tube construction is unacceptably stiffer to torsional loading and will give rise to unnecessarily high insertion forces and unpredictable distortion.
Having in mind the above and other objects that will be obvious from an understanding of the disclosure, the present invention comprises a combination and arrangement of parts illustrated in the presently preferred embodiment of the invention which is herein set forth in sufficient detail to enable those persons skilled in the art to clearly understand the function, operation, construction and advantage of it when viewed in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be described in detail, by way of example, with reference to the accompanying drawings in which:
FIG. 1 is a pictorial view of the connector;
FIG. 2 is an end view of the socket member;
FIG. 3 is a pictorial view of the mated contact members;
FIG. 4 is a sectional view of the mated contact members taken along line 4--4 of FIG. 3;
FIG. 5 is a pictorial view of an alternative embodiment of the invention;
FIG. 6 is a cross-sectional view taken along line 6--6 in FIG. 5;
FIG. 7 is a pictorial view of the mated connectors of the alternative embodiment; and
FIG. 8 is a sectional view taken along line 8--8 in FIG. 7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 and 2 of the drawing and in accordance with the principles of the invention, an electrical connector assembly 10 without a housing is shown comprising a male or pin member 12 formed of electrically conductive material and shaped as an elongated prism having a polygonal cross-section that may be square, rectangular, triangular or other such geometrical shape with each of the surfaces thereof being planar. A tapered portion 14 is formed into the leading end of the pin 12 while the opposite end 16 would be configured for connecting with wires (not shown) or other conductors such as conductive traces on a printed circuit board for carrying electric current to or from the pin 12. The female or socket member 18 includes an elongated tubular body 20 having a cross-section matching that of the pin 12. The tubular body 20 forms a through passageway 22 having an opening 23 at one end while the opposite end 25 is also configured for attachment to conductor wires, printed circuit board traces or other elements. The passageway 22 is sized to allow the pin 12 to slide completely through in a close fitting connection. As shown in FIG. 2, the tubular body 20 is formed as a progressively skewed member with the skew axis coincident with the longitudinal axis of the tubular body 20. The passageway 22 takes on a helical configuration with each defining wall 24, 24a thereof similarly twisted. In FIG. 2, the angular twist A of the tubular body is apparent.
The tubular body 20 is not a continuous structure, but has an elongated slit 26 longitudinally parting any one wall 24a. The edges 26a defining the slit 26 may be abutting or have a finite gap between them. Entrance of the pin 12 through the opening 23 and along the length of the passageway 22 in the tubular body 20 and emerging from the opposite end 25 forms a mating assembly as shown in FIG. 3. The pin and socket overlap by the distance "L" defining the mating length. The insertion of the rigid pin 12 causes the deformable tubular body 20 to counter-rotate and change from a helical configuration to a generally straight prism conforming to the shape of the pin. The contact between the pin 12 and socket 18 falls along the corners 28 of the pin 12 and the inner surfaces of the walls 24, 24a of the passageway 22 as shown in FIG. 4 at K, L, M and N.
The significance of creating a torsional stress in the socket 18 is that the resulting contact stresses are distributed along the entire mating length L and will give rise to a uniform insertion force and sufficient contact force necessary for low contact resistance or good electrical conductivity as well as enough normal force for creating friction to maintain the engagement of the pin 12 and socket 18 to prevent separation under severe shock and vibration environments.
Unlike bending stresses which are maximum at the point of connection of a beam to a fixed portion of the terminal, torsional stresses are equally distributed along the full mating length L of the terminal socket member allowing the optimum condition for stress distribution. It is well known in the study of mechanics that a closed tube is extremely resistant to torsional deformation but an interrupted or partially closed tube, such as one with a longitudinal slit 26 can be twisted by the application of a lower insertion force. Of more significance is that the force applied to a closed tube will distort and warp all the walls 24, 24a while the incorporation of a slit 26 allows the walls 24, 24a to come to a near planar shape when counter-rotated or untwisted by the insertion of a straight and close fitting pin member 12 having a matching cross-section.
In an alternative embodiment shown in FIGS. 5 and 6, the pin member 112 is progressively skewed into a helical configuration about its longitudinal axis twisting each of the surfaces or faces thereof while the socket 118, including the interrupted tube member 120 and passageway 122 form a straight prism having walls 124 and 124a all perpendicular to the opening 123 at the front end. A slit 126, which may be closed or open as previously described, is also cut through any one of these walls 124a. Mating of the pin member 112 and the socket 118 by insertion of the tapered end 114 of the pin 112 into the opening 123 and through the passageway 122 places the straight socket 118 under torsional loading and causes it to rotate or twist and assume the helical configuration of the pin 112 as shown in FIG. 7.
As in the previous embodiment, the torsional load produced during the insertion of the pin 112 into the socket 118 would normally be passed through these members to their respective mounting points on the printed circuit boards or the like. If however, the entire socket member 118 were free to rotate about its longitudinal axis, no torsional effect would be felt at the pin mounting point.
Again, this torsional loading of the socket member generates distributed stresses along the mating length L thus creating contacts at points P, Q, R, and S along the edges 128 of the pin member 112 as shown in FIG. 8. The interruption in the perimeter of the tubular member 120 by the slit 126 makes it possible to achieve the described distributed stress loading and assure optimum electrical conductivity or low contact resistance and contact normal forces as does the first embodiment.
While the preferred embodiments of the invention are described, it will be understood that the invention is in no way limited by these embodiments.
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An electrical connector contacts assembly having a solid elongated pin member and a hollow socket member each having like cross-sections for closely removably inserting the pin through the socket. The socket body is twisted into a helical configuration while the pin is straight-sided. The assembly of the members reconfigures the more resiliant socket into the configuration of the pin setting up torsional stresses that create a uniformly distributed torsional force load between the pin and socket for achieving low electrical resistance therebetween.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Priority of U.S. Provisional Patent Application Ser. No. 61/825,325 filed 20 May 2013, which is hereby incorporated herein by reference, is hereby claimed.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable
REFERENCE TO A “MICROFICHE APPENDIX”
[0003] Not applicable
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The system of the present invention relates to over-pressured coal seams and coal bed methane drilling and completion. More particularly, the present invention relates to a continuous circulating concentric casing system for controlled bottom hole pressure for coal bed methane drilling without the use of weighted drilling fluids containing chemicals utilizing annular friction control and or in conjunction with surface choking to provide the required hydrostatic pressure within the bore hole.
[0006] 2. General Background
[0007] In over-pressured coal (CBM) seams and in circumstances when drilling in the direction perpendicular to the face cleats in the coal seams, which has the highest permeability, but in the lowest borehole stability direction, coal seam permeability is easily damaged by the addition of any chemicals or weighting agents as it becomes necessary to have a fluid in the hole with a higher specific gravity heavier than water. In the prior art, to obtain a specific gravity heavier than water, weighting agents and chemicals have been added to water to obtain a desired hydrostatic weight. What happens in coal is that coal has a unique ability to absorb, and to adsorb a wide variety of chemicals that irreversibly reduce the permeability by as much as 85%.
[0008] An objective of the present invention is to eliminate a need to add weighting agents and chemicals. The method of the present invention creates back pressure thru the use of either friction on the return annulus or to choke the return annulus, creating back pressure on the formation, or to use a combination of both to create, thru continuous circulating, an induced higher Equivalent Circulating Density (ECD) on the formation. Thus the formation thinks it has a heavier fluid in the hole but only has water in the annulus. This way formation damage is eliminated and higher pressures are exerted in the wellbore creating a reduced collapse window and reduced wellbore collapse issue.
BRIEF SUMMARY OF THE INVENTION
[0009] The present invention solves the problems faced in the art in a simple and straightforward manner. The present invention provides a method of drilling multiple boreholes within a single caisson, to recover methane gas from coal seams, including the steps of drilling first and second vertical boreholes from a single location within a single caisson; drilling at least one or more horizontal wells from the several vertical bore hole, the horizontal wells drilled substantially parallel or at a 45 degree angle to a face cleat in the coal bed; drilling at least one or more lateral wells from the one or more horizontal wells, the lateral wells drilled substantially perpendicular to one or more face cleats in the coal seam or seams; continuously circulating water through the drilled vertical, horizontal and lateral wells to recover the water and cuttings from the coal seam; applying friction or choke manifold to the water circulating down the well bores so that the water creates an Equivalent Circulating Density (ECD) pressure within the well bore sufficient to maintain an equilibrium with the hydrostatic pressure in the coal bed formation; and drilling at least a third vertical borehole within the single caisson, with one or more horizontal boreholes and one or more lateral boreholes for returning water obtained from the lateral producing wells into a water zone beneath the surface for water injection during the production phase.
[0010] In the system of the present invention, the present invention would enable the prevention of pressured CBM (over-pressured coal) reservoir damage. This may be done through the use of concentric casing string for annular friction control and in combination with surface choking systems control of bottom hole pressures, which allows the reservoir to be drilled and completed in a non-invasive and stable bore hole environment. Manage Pressure Drilling (MPD) may be accomplished by many means including combinations of backpressure, variable fluid density, fluid rheology, circulating friction and hole geometry. MPD can overcome a variety of problems, including shallow geotechnical hazards, well bore instability, lost circulation, and narrow margins between formation pore pressure and fracture gradient.
[0011] In an embodiment of the method of the present invention, the method comprises drilling multiple boreholes within a single caisson, to recover methane gas from a coal bed, comprising the following steps: (a) drilling a first vertical borehole from a single location within a single caisson; (b) drilling at least one horizontal well from the vertical bore hole, the horizontal well drilled substantially parallel to a face cleat in the coal bed; (c) drilling at least one or more lateral wells from the horizontal well, the lateral wells drilled substantially perpendicular to one or more face cleats in the coal bed; (d) continuously circulating water through the drilled wells to circulate water and cuttings from the coal bed; and (e) applying friction and or choke methods or a combination of both to the water circulating so that the water attains a hydrostatic pressure within the well sufficient to maintain an equilibrium with the hydrostatic pressure in the coal bed formation to prevent collapse of the well.
[0012] In another embodiment of the method of the present invention, there is drilled at least a second vertical borehole within the single caisson, with one or more horizontal boreholes and one or more lateral boreholes for recovering methane gas and water from the second borehole using the continuous circulating process and maintaining the water under a certain hydrostatic pressure equal to the pressure within the coal bed.
[0013] In another embodiment of the method of the present invention, there is drilled at least a third vertical borehole within the single caisson, with one or more horizontal boreholes and one or more lateral boreholes for returning water received from the first and second wells into a waste water zone beneath the surface.
[0014] In another embodiment of the method of the present invention, the water recovered from the coal bed seam is separated removing solids, filtered and returned down the third borehole into the waste water zone, while the methane gas is stored above the surface.
[0015] In another embodiment of the method of the present invention, imparting a friction component to the flow of the water as it is circulated within the drilled wells provides a greater hydrostatic pressure to the water equal to the hydrostatic pressure obtained by using chemicals in the water that may be harmful to the coal bed and impede recovery of the methane gas.
[0016] In another embodiment of the method of the present invention, circulating fresh untreated water with greater hydrostatic pressure obtained by friction or a choke manifold down the drilled wells to recover the methane gas eliminates the use of chemicals in the water which would reduce or stop the flow of methane gas from the coal bed formation.
[0017] In another embodiment of the method of the present invention, the recovery of the methane gas from the coal formation would be done through lateral wells being drilled perpendicular to face cleats in the coal bed formation for maximum recovery of methane gas.
[0018] Another embodiment of the method of the present invention comprises a method of drilling multiple boreholes within a single caisson, to recovery methane gas from a coal bed, comprising the following steps: (a) drilling first and second vertical boreholes from a single location within a single caisson; (b) drilling at least one or more horizontal wells from the several vertical bore holes, the horizontal wells drilled substantially parallel to a face cleat in the coal bed; (c) drilling at least one or more lateral wells from the one or more horizontal wells, the lateral wells drilled substantially perpendicular to one or more face cleats in the coal bed; (d) continuously circulating water through the drilled vertical, horizontal and lateral wells to recover the water and entrained methane gas from the coal bed; e) applying friction or choke manifold to the water circulating down the well bores so that the water attains a hydrostatic pressure within the well sufficient to maintain an equilibrium with the hydrostatic pressure in the coal bed formation; and (f) drilling at least a third vertical borehole within the single caisson, with one or more horizontal boreholes and one or more lateral boreholes for returning the water circulated from the lateral wells into a waste water zone beneath the surface.
[0019] In another embodiment of the method of the present invention, the recovery of the methane gas from the coal formation would be done through lateral wells being drilled perpendicular to face cleat fractures in the coal bed formation for maximum recovery of methane gas.
[0020] In another embodiment of the method of the present invention, one or more horizontal wells are drilled from the vertical well, each horizontal well drilled parallel to the face cleat fractures in the coal bed and one or more lateral wells are drilled from the horizontal wells, each lateral well drilled perpendicular to the face cleat fractures to provide a maximum recovery of methane gas as the laterals wells penetrate a plurality of face cleat fractures.
[0021] Another embodiment of the method of the present invention comprises a method of drilling multiple boreholes within a single caisson, to recovery methane gas from a coal bed, comprising the following steps: (a) drilling first and second vertical boreholes from a single location within a single caisson; (b) drilling at least one or more horizontal wells from the several vertical bore holes, the horizontal wells drilled substantially parallel to a face cleat in the coal bed; (c) drilling at least one or more lateral wells from the one or more horizontal wells, the lateral wells drilled substantially perpendicular to one or more face cleats in the coal bed; (d) continuously circulating water through the drilled vertical, horizontal and lateral wells to recover the water and entrained methane gas from the coal bed; (e) applying friction or choke manifold to the water circulating down the well bores so that the water appears to have a hydrostatic pressure within the well sufficient to maintain an equilibrium with the hydrostatic pressure in the coal bed formation; and (f) drilling at least a third vertical borehole within the single caisson, with one or more horizontal boreholes and one or more lateral boreholes for returning water obtained from the lateral wells into a waste water zone beneath the surface.
[0022] In another embodiment of the method of the present invention, imparting friction or choke to the circulating water, increases the hydrostatic effects of the water from a weight of 8.6 lbs/gal to at least 12.5 lbs/gal, substantially equal to the hydrostatic pressure of the coal formation.
[0023] Another embodiment of the present invention comprises a method of recovering methane gas from a pressurized coal bed through one or more wells within a single caisson by continuously circulating untreated water having an effective hydrostatic pressure equal to the coal bed formation, so that methane gas entrained in the formation can flow into the circulating water and be recovered from the circulating water when the water is returned to the surface, and the water can be recirculated into a waste water zone beneath the surface through a separate well within the caisson.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
[0025] FIG. 1 illustrates an overall view of multiple wells being drilled out of a single caisson from a single location in the method of the present invention;
[0026] FIG. 2 illustrates a cross-section view of the multiple wells within the caisson as illustrated in FIG. 1 in the method of the present invention;
[0027] FIG. 3A illustrates a water injection well to return waste water into the formation utilizing a vertical well in the method of the present invention;
[0028] FIG. 3B illustrates a water injection well returning waste water into the formation through a use of a horizontal well extending from the vertical well in FIG. 3A in the method of the present invention;
[0029] FIG. 4 illustrates yet another embodiment of the water injection well in FIGS. 3A and 3B , where there are multiple lateral wells extending out from the horizontal well in the method of the present invention;
[0030] FIG. 5 illustrates a depiction of the drilling of the lateral wells perpendicular to the face cleats in the coal seam to recover maximum of methane gas from the coal seam in the method of the present invention;
[0031] FIG. 6 illustrates the single pass continuous circulation drilling utilized in the method of the present invention;
[0032] FIG. 7 illustrates the continuous circulating concentric casing pressure management with friction and choke methods in the method of the present invention;
[0033] FIG. 8 illustrates a wellhead for continuous circulation in the method of the present invention;
[0034] FIG. 9 illustrates a plurality of lateral wells which have been lined with liners as the methane gas is collected from the coal seam in the method of the present invention;
[0035] FIG. 10 illustrates an overall view of the methane gas collection from the coal seam utilizing a plurality of lateral wells and the water injection well returning used water into the underground, all through the same caisson in the method of the present invention;
[0036] FIG. 11 illustrates a depiction of a plurality of horizontal wells having been drilled parallel to the face cleats and a plurality lateral wells having been drilled perpendicular to the face cleats in the coal seam for obtaining maximum collection of methane gas; and
[0037] FIG. 12 illustrates a continuous circulating concentric casing in the method of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0038] FIGS. 1 through 11 illustrate the preferred method of the present invention, which in summary is a plurality of wells being drilled through a single caisson from the rig floor, at least two of the wells drilled for the ultimate collection of methane gas from a coal seam, and a third well drilled to return waste water used in the process to a water collection zone beneath the surface.
[0039] Turning now to the individual Figures, as seen in overall view in FIG. 1 , and in cross-section view in FIG. 2 , there is illustrated in overall view in FIG. 1 , a drilling rig 20 having a single caisson 22 with three wells 24 , 26 , 28 within the single caisson 22 . As seen, each of the wells include a vertical well section 29 , which terminates in at least one or more horizontal wells 30 , which branch off into a plurality of lateral wells 32 , for reasons stated herein. Of the three wells depicted, two of the wells 24 , 26 are multilateral wells to produce water and methane gas, while the third well 28 comprises an injection well 28 that can inject waste water back into one of the underground reservoirs.
[0040] The two producing wells 24 , 26 would produce the water and methane gas after completion, where the recovery from these wells would be run thru a centrifuge 82 (as seen in FIG. 7 ) to remove the fine particles during the drilling phase and additionally a centrifuge would be used after completion to remove the coal fines for re-injection, while for the third well 28 , water would be re-injected back into the earth in a water bearing zone. The configuration of the three wells 24 , 26 , 28 within a single conduit or caisson 22 is important and novel since this allows the single site to produce gas through the circulated water in wells 24 , and 26 , and send waste water down into the water bearing zone via well 28 , rather than on site collection ponds, which may be required in some jurisdictional legal guidelines.
[0041] As further illustrated in FIGS. 3A and 3B , water 36 is being injected into a vertical well section 29 ( FIG. 3A ), or into a horizontal well 30 ( FIG. 3B ) or into a horizontal with multiple laterals 32 , as seen in FIG. 4 for sending the water into water bearing zones in formation 31 . FIG. 4 depicts injection down the hole of produced water or produced waste water 37 that has been run thru solids removal equipment.
[0042] In understanding the nature of a coal seam, coal seams contain face cleats and butt cleats. All of the face cleats comprise cracks in the coal seam which are in a certain direction and comprise the pathway for gas movement thru the coal seam, while the butt cleats connect the face cleats. In a coal seam all major fractures, or face cleats, are in the same direction. Therefore, if one drills in parallel to the face cleats, and only connects two of them, this is the most stable direction. But, if one drills perpendicular to the face cleats, and connects all of the fractures, the recovery is very good, which has, in effect, created a new mechanical induced butt cleat, i.e., connecting one or more face cleats. Drilling from parallel to perpendicular requires more hydrostatic pressure, i.e. mud weight, going from stable to unstable. Most drillers want to drill parallel to the face cleats to avoid the instability in the well. For example, the mine shaft in a coal mine may be mined parallel to the face cleats, to avoid collapse of the mine shaft. However, in coal bed drilling for methane gas, the recovery, when one drills perpendicular to the face cleats is 10 to 20 times more productive; therefore, the most productive direction is to drill perpendicular.
[0043] With that in mind, turning now to FIG. 5 , it has been determined that if there is a fracture in the coal seam, referenced as face cleat fractures 50 , that these face cleat fractures 50 would all be parallel one another in the coal seam. One would drill a vertical well, such as well 24 , and drill the horizontal well 30 parallel to the fractures 50 for attaining the most stable well bore, which means the less likely to collapse under downhole pressures. Drilling parallel to the fractures 50 is the most stable direction, but it is the least productive of the drilling. One would want to be able to drill perpendicular to the fractures 50 for maximum production of methane gas through the lateral wells 32 . As stated earlier, drilling perpendicular to the fractures is useful because production of methane gas is ten to twenty times greater when the production wells are perpendicular to the fractures 50 rather than parallel to the fractures 50 .
[0044] In an embodiment of the present invention, to drill perpendicular to the face cleat fractures 50 in a stable environment, one would provide higher hydrostatic pressure by higher mud weight or, with water alone, having the water exhibit characteristics which renders its weight or ECD from 8.6 to 12.6 lbs/gal, for example. An embodiment of the present invention provides the desired weight or ECD thru creating mechanical friction, since fluid has resistance, which creates back pressure. In another embodiment, using fresh water, the method comprises use of chokes on surface. For example, one would pump in 100 gallons, but only let out 90 gallons, therefore creating back pressure. The back pressure caused by this process would give greater weight effect or ECD to the water, and increase sufficient hydrostatic pressure in the well bore.
[0045] In an embodiment of the present invention, one would use treated water free from any chemicals and bacteria. An object of the present invention is to enable a cleaner formation with no damage by chemicals. However, because the perpendicular drilled wells create instability, in order to minimize that problem, a higher bottom hole pressure is useful, when the coal seam is pressurized down hole. As discussed earlier, in order to minimize a coal seam from being damaged by mud additives added to water in order to create a greater hydrostatic pressure, in a preferred embodiment one would drill with clear water. However, it is difficult to obtain the proper hydrostatic pressure to keep the well from collapsing with just water, without increasing the hydrostatic pressure in some manner. In coal reservoirs which are pressured, there is a need for a process to obtain instantaneous increases of hydrostatic pressure from 8.6 to 12.6 lbs per gallon mud or higher, such as barite or other chemicals added to the water. These chemicals damage the permeability in the formation, actually holding back the pressure, and reduce the opportunity for desorption of methane gas from the formation. Therefore, in a preferred embodiment pure or clear water (containing less than 4 microns of solids drilling fluid, for example) is used, which has a weight of 8.6, but has the effect as the heavier mud, at possibly 12 lbs/gal. In a preferred embodiment of the present invention, to address this problem, one would drill the wells from the parallel or sub-parallel to the perpendicular, without agents, such as chemicals, and with use of friction or back pressure, or a combination of both, as discussed earlier. These means, i.e. the friction or back pressure, can increase the circulating density of the fluid, which is only water in a preferred embodiment.
[0046] Turning therefore to FIGS. 6 through 8 , these figures show that on the surface systems may be used to increase friction within the well or through the use of a choke manifold, or a combination of both circulated continuously down the concentric annulus, both of which would cause the water to exhibit a greater hydrostatic pressure, of a suitable magnitude, without the use of chemical or surfactants. By creating the higher equivalent of back pressure, through friction or a choke manifold, one is able to drill the wells perpendicular, for greater recovery of methane gas. That allows one to drill perpendicular and have a higher effective bottom hole pressure without having the bore collapse. There are no chemical agents, such as surfactants involved, which can cause the clay to swell and choke off the flow of gas out of the formation.
[0047] It should be noted that as seen in FIGS. 6 through 8 , the system, in a preferred embodiment, would be a continuous circulating system for reducing the likelihood of the formation collapsing under pressure, wherein the water through either friction or the choke valve maintains a 10 lb. per sq. inch pressure down hole, for example, without the use of chemicals.
[0048] In FIG. 6 , water is pumped from pumps 70 and 72 via line 74 to the stand pipe 76 and circulated down the borehole. While circulating, due to the hydrostatic pressure of the water and choking effects, for reasons described earlier, the formation remains stable. The water is then returned from the borehole, and after cleansing through the shale shaker 78 , de-silter 80 , and decanting centrifuge 82 , the water returns to pumps 70 and 72 .
[0049] In FIGS. 7-8 , the water is being pumped from pump 70 via line 74 to stand pipe 76 returning up bore 90 . Simultaneously pumping with pump 70 from pump 72 via line 103 , then down annulus 104 thru perforations 100 , and returns comingled with fluid from pump 70 up the inner annulus 98 of the well, and goes to the rig manifold 94 . This creates both friction control of the annulus and choking to increase the hydrostatic ECD control of bottom hole pressure. The water is then cleansed and returns to pumps 70 and 72 . FIG. 8 illustrates a view of a well head 102 , with the water being pumped down an inner bore 96 , and returned up an annulus 98 where the water from pump 70 and pump 72 are comingled creating the friction effect for hydrostatic friction which then returns to the rig floor for additional choking effect and separation. In a preferred embodiment the present invention is a continuous circulation system, if circulation stops, i.e., turn the pumps off, this can create a loss of friction and choking, so that the formation may collapse. Pump 72 during connections can increase its flow to match the gallons per minute of both pumps 70 and 72 to maintain the friction effect. After a connection is made and flow is re-established to pump 70 , pump 72 can slow to the comingled volume and maintain the friction effect.
[0050] As illustrated in FIG. 9 , at some point in time during the process, one may wish to case the laterals 32 off. FIG. 9 illustrates slotted liners 60 which have been inserted into each of the laterals 32 . This is useful to help maintain the integrity of the laterals 32 during the method of the invention.
[0051] In FIG. 10 , there is again depicted an overall view of a drilling rig 20 with multiple wells from a single caisson 22 , where some of the laterals 32 from wells 24 , 26 are collecting methane gas by continuously circulating water into the formation, while laterals 32 from a third well 28 are returning waste water to the water bearing zones beneath the surface. In FIG. 11 , there is depicted the vertical wells extending from the single caisson 22 , where there are a plurality of horizontal wells 30 drilled in the same direction as the face cleat fractures 50 , to maintain stability, but where there are a plurality of lateral wells 32 being drilled perpendicular to the horizontal wells 30 through multiple face cleats 50 of the coal seam, to obtain maximum methane gas recovery. In an embodiment of the present invention, cased hole or open hole may be used, wherein the hydrostatic pressure is maintained through the continuous circulation of the water through the system under friction or through a choke at the surface, for maintaining the hydrostatic pressure of the water sufficiently high to prevent collapse of the formation at all times.
[0052] In an embodiment of the present invention, the novel system for recovering methane gas from coal seams involves a continuously circulating concentric pressure drilling program which may be adapted to include a splitter wellhead system for purposes of using a single borehole with three wells, or conduits, in the single borehole, with two of the conduits used for completing coal bed methane wells, and the third used as a water disposal well all within a single well caisson.
[0053] An embodiment of the present invention, involves a process for recovering methane from coal seams through the following steps: drilling and installing a caisson with multiple conduits; drilling a well bore through the conduit into a coal seam; using a continuous circulating process to drill and complete those wells within the coal seam with the lateral wells being perpendicular to the face cleats of the coal seam so that the well extends through multiple face cleats for maximum recovery of methane gas; completing each well either open or cased hole; next, drill the second well, and complete a series of multi-lateral wells into the coal seam perpendicular to the face cleat fractures as described earlier; then, in the third conduit, drill a vertical or horizontal or multilateral well for disposing the water produced from the other two conduits. The water would be returned through a pumping mechanism from conduits 1 and 2 , filtered for solids removal, and re-injected into the well bore via the borehole in conduit 3 . The present invention overcomes problems in the prior art thru use of multiple wells drilled from a single caisson in a coal bed methane system, using friction and choking methods to maintain the proper hydrostatic pressure of pure water, for coal bed methane recovery in at least two of the wells, and injecting water down hole, all within the same vertical well bore.
[0054] In an embodiment of the method of the present invention for a continuous circulating concentric casing managed equivalent circulating density (ECD) drilling method, the method involves a continuous circulating concentric casing using less than conventional mud density. Using less than conventional mud density, the well will be stable and dynamically dead, but may be statically underbalanced (see FIG. 12 ). As stated earlier, in an embodiment of the invention and in the well planning, one would drill wells perpendicular to the face cleats of the coal. From the face cleat direction, there would be a single fracture, reorientation and a single t-shaped multiple 105 provided as seen in FIG. 5 .
[0055] For purposes of the below paragraph, the following abbreviations will apply:
[0056] Equivalent Circulating Density (ECD)
[0057] Managed Pressure Drilling (MPD)
[0058] Bottom Hole Pressure (BHP)
[0059] Bottom Hole Circulating Pressure (BHCP)
[0060] Mud Weight (MW)
[0061] The MPD advantage as seen is at under conventional drilling MPD=MW+Annulus Friction Pressure. BHP control=only pump speed and MW change, because it is an “Open to Atmosphere” system; whereas in Managed Pressure Drilling (MPD), the MPD=MW+Annulus Friction Pressure+Backpressure. BHP control=pump speed, MW change and application of back pressure, because it is an enclosed, pressured system.
[0062] In the continuous circulating concentric casing pressure management, there is provided an adaptive drilling process used to precisely control the annular pressure profile throughout the wellbore. The objectives are to ascertain the downhole pressure environment limits and to manage the annular hydraulic pressure profile accordingly. It is an objective of the system to manage BHP from a specific gravity of 1 to 1.8 utilizing clean, less than 4 microns of solids, for example, in the drilling fluid. The drilling fluid may be comprised of produced water from other field wells. Any influx incidental to the operation would be safely contained using an appropriate process.
[0063] FIG. 12 illustrates a continuous circulating concentric casing where using less than conventional mud density, the well will be stable and dynamically dead, but may be statically underbalanced.
[0064] The following is a list of parts and materials suitable for use in the present invention:
PARTS LIST
[0065]
[0000]
PART NUMBER
DESCRIPTION
20
drilling rig
22
caisson
24, 26, 28
wells
29
vertical well section
30
horizontal wells
31
formation
32
lateral wells
36
water
37
produced waste water
50
face cleat fractures
60
slotted liners
70, 72
pumps
74
line
76
stand pipe
78
shale shaker
80
de-silter
82
centrifuge
90
bore
94
rig manifold
96
inner bore
98
annulus
100
perforations
102
well head
103
line from pump 72
104
inner annulus
105
t-shaped multiple
[0066] All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise.
[0067] 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.
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A method of drilling multiple boreholes within a single caisson, for recovery of methane gas from a coal bed, including the steps of drilling first and second vertical boreholes from a single location within a single caisson; drilling at least one or more horizontal wells from the several vertical bore hole, the horizontal wells drilled substantially parallel to a face cleat in the coal bed; drilling at least one or more lateral wells from the one or more horizontal wells, the lateral wells drilled substantially perpendicular to one or more face cleats in the coal bed; continuously circulating water through the drilled vertical, horizontal and lateral wells to recover the water and entrained methane gas from the coal bed; applying friction or choke manifold to the water circulating down the well bores so that the water appears to have a hydrostatic pressure within the well sufficient to maintain an equilibrium with the hydrostatic pressure in the coal bed formation; and drilling at least a third vertical borehole within the single caisson, with one or more horizontal boreholes and one or more lateral boreholes for returning water obtained from the lateral wells into a water zone beneath the surface.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. patent application Ser. No. 14/087,980, filed 22 Nov. 2013, which is a continuation and claims the benefit of U.S. patent application Ser. No. 13/663,272, filed 29 Oct. 2012, now issued U.S. Pat. No. 8,647,377, which is a continuation of U.S. patent application Ser. No. 13/533,658, filed 26 Jun. 2012, now issued U.S. Pat. No. 8,535,367, which is a continuation of U.S. patent application Ser. No. 11/552,913, filed 25 Oct. 2006, now issued U.S. Pat. No. 8,231,665, which is a continuation of U.S. patent application Ser. No. 10/301,061, filed 20 Nov. 2002, now abandoned, which claims the benefit of U.S. Provisional Application No. 60/333,373, filed 26 Nov. 2001, which are all incorporated herein by reference in their entireties.
BACKGROUND OF THE INVENTION
The present invention relates to devices and methods for the treatment of diseases in the vasculature, and more specifically, devices and methods for treatment of aneurysms found in blood vessels. Aneurysms can occur in various areas of the cardiovascular system, but are commonly found in the abdominal aorta, thoracic aorta, and cerebral vessels. Aneurysms are unusual ballooning of the vessel due to loss of strength and/or elasticity of the vessel wall. With the constant pulsating pressure exerted on the vessel wall, the diseased or weakened wall can expand out and potentially rupture, which frequently leads to fatality. Prior methods of treating aneurysms have consisted of invasive surgical techniques. The technique involves a major cut down to access the vessel, and the diseased portion of the vessel is replaced by a synthetic tubular graft, Accordingly, this invasive surgical procedure has high mortality and morbidity rates.
Due to the inherent risks and complexities of the surgical procedures, various attempts have been made to develop minimally invasive methods to treat these aneurysms. For treatment of abdominal and thoracic aortic aneurysms, most of the attempts are catheter-based delivery of an endoluminal synthetic graft with some metallic structural member integrated into the graft, commonly called stent-grafts. One of the primary deficiencies of these systems is durability of these implants. Because catheter-based delivery creates limitations on size and structure of the implant that you can deliver to the target site, very thin synthetic grafts are attached to metallic structures, where constant interaction between the two with every heartbeat can cause wear on the graft. Also, the metallic structures often see significant cyclical loads from the pulsating blood, which can lead to fatigue failure of the metallic structure. The combination of a thin fragile graft with a metallic structure without infinite life capabilities can lead to implant failure and can ultimately lead to a fatality.
While the above methods have shown some promise with regard to treating aortic aneurysms with minimally invasive techniques, there remains a need for a treatment system which doesn't rely on the less than optimal combination of a thin graft and metallic structural member to provide long-term positive results. The present invention describes various embodiments and methods to address the shortcomings of current minimally invasive devices and to meet clinical needs.
SUMMARY OF THE INVENTION
In a first aspect, the present invention provides a two part prostheses where one part is an expandable sponge structure and the other part is an expandable tubular mesh structure. The expandable sponge structure is intended to fill the aneurysm cavity to prevent further dilatation of the vessel wall by creating a buffer or barrier between the pressurized pulsating blood flow and the thinning vessel wall. The expandable tubular mesh structure, which is placed across the aneurysm contacting the inner wall of healthy vessel proximal and distal to the aneurysm, serves two purposes. One, it defines the newly formed vessel lumen, even though it does not by itself provide a fluid barrier between the blood flow and the aneurysm. Two, it keeps the expandable sponge structure from protruding out of the aneurysm and into the newly formed vessel lumen. The expandable tubular mesh structure is delivered first across the aneurysm. Then, the expandable sponge structure is delivered via a catheter-based delivery system through a “cell” of the tubular mesh structure and into the aneurysm sac. When the sponge structure is deployed into the aneurysm sac and comes in contact with fluid, it will expand to a size larger than the largest opening or cell of the tubular mesh structure as to prevent the sponge structure from getting out of the aneurysm sac. The filled aneurysm sac will most likely clot off and prevent further dilation of the aneurysm and subsequent rupture. The blood flow should maintain a natural lumen Where the luminal diameter is approximately defined by the diameter of the tubular mesh structure. The advantage of this system is that the sponge filler material acts like a graft but has unparalleled durability. The metallic structure can be optimized for durability as well because the size constraint is somewhat relieved due to the absence of an integrated graft material, which takes up a significant amount of space in a catheter.
In addition, the expandable sponge structure can be used to repair existing endoluminal stent-grafts which have developed leaks. There are thousands of endoluminal stent-grafts implanted into humans to treat abdominal aortic aneurysms. That number is growing daily. The endoluminal stent-grafts are intended to exclude the aneurysm from blood flow and blood pressure by placing a minimally porous graft supported fully or partially by metallic structural members, typically called stents. The acute success rate of these devices is very high, but there are a significant number of these which develop leaks, or blood flow/pressure re-entering the aneurysm sac, some time after the procedure. If the source of the leak can be accessed by the delivery system, the expandable sponge structure can be deployed through that access point.
In another aspect, the present invention provides an inflatable tubular balloon graft. It is a tubular graft, straight or bifurcated, where its wall is not a solid structure but a hollow chamber. The chamber can be filled with a variety of materials which can dictate the mechanical properties of the prostheses. The unfilled tubular balloon graft can be folded and loaded into a catheter-based delivery system, and once in position the tubular balloon graft can be “inflated” with the filler material. The material would be filled in a fluid form and may stay a fluid form or can be solidified by various means such as UV light, heat, and time. The advantage of this system is that a metallic structure is not needed to provide structure to the graft. It is instead replaced by the injectable fluid within the chamber of the tubular balloon graft. Customization of the mechanical properties of the graft is easily accomplished by using balloon fillers of varying properties.
The tubular balloon graft can be completely non-porous, completely porous with same degree of porosity throughout the graft, completely porous with varying porosity within the graft, or partially non-porous and partially porous. Significant porosity on the very outer layer would allow for delivery of an aneurysm sac filling substance or a drug. Porosity on the ends of the graft will help promote cellular in-growth. Porosity on the ends can also he used to deliver an adhesive so that the graft can be securely attached to the vessel wall.
Another embodiment of the tubular balloon graft includes a tubular balloon graft with a bulging outer layer. This will allow the outer surface of the tubular balloon graft to fill some or all of the aneurysm. This will provide a primary or secondary barrier for the aneurysm wall from the pulsating blood flow and will provide a means to prevent migration of the graft due to the enlarged area within the graft. An alternate method of construction would be to attach a bulging outer skin to a standard tubular thin-walled graft and provide a port for injection of the filler substance. Alternatively, instead of a bulging outer skin, a very compliant outer skin can he used so that the volume of material is minimized. The compliant outer skin would be able to expand at very low inflation pressures that would be non-destructive to the aneurysm wall.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A illustrates the two-part prosthesis.
FIG. 1B illustrates a bifurcated version of the expandable tubular mesh structure and the expandable sponge structure.
FIG. 1C illustrates an expandable tubular mesh structure placed across an aneurysm and the expandable sponge structure filling up the aneurysm.
FIGS. 2A-2C illustrate the various cross-sections of the expandable sponge structure.
FIG. 3A illustrates a long continuous sponge structure.
FIG. 3B illustrates multiple short sponge structures.
FIG. 4 illustrates the catheter-based delivery system.
FIG. 5 illustrates a curved delivery catheter.
FIG. 6 illustrates a method of ensuring that the delivery catheter's tip stays inside the aneurysm sac.
FIG. 7A illustrates an expandable basket-like structure.
FIG. 7B illustrates an expandable braid-like structure.
FIG. 8 and 9 illustrate expandable tubular mesh structures.
FIG. 10 illustrates a delivery catheter tracked over a guidewire and placed in a stent-graft which developed a leak.
FIG. 11 illustrates the sponge delivered through the delivery catheter.
FIGS. 12-15 illustrate tubular balloon grafts.
FIGS. 16 and 17 illustrate tubular balloon grafts being expanded.
FIG. 18 illustrates a tubular balloon graft.
FIGS. 19, 20A and 20B illustrate a vascular graft with an integrated tubular balloon.
FIGS. 21A-21E illustrate a method of delivering a graft with an external balloon.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1A shows the two-part prosthesis comprising of an expandable sponge structure 1 and an expandable tubular mesh structure 2 placed in an abdominal aortic aneurysm 3 located in the infra-renal aorta not involving the iliac arteries. FIG. 1B shows a bifurcated version of the expandable tubular mesh structure 2 and the expandable sponge structure 1 in an abdominal aortic aneurysm located in the infra-renal aorta and involving both iliac arteries. FIG. 1C shows an expandable tubular mesh structure 2 placed across an aneurysm commonly found in cerebral arteries and the expandable sponge structure 1 filling up the aneurysm. The expandable sponge structure 1 is placed through the expandable tubular mesh structure 2 into the aneurysm, filling up the aneurysmal sac which provides a barrier between the thin fragile wall of the aneurysm and the pressurized pulsating blood. The tubular mesh structure 2 keeps the expanded sponge 1 within the confines of the aneurysm and away from the flow path.
The expandable sponge structure 1 is preferably made of common medical grade polymers or natural substances like collagen which can be manufactured into a sponge structure. The sponge structure can be processed in such a way so that it can be compressed to a dry condition size substantially smaller than the wet condition size, exhibiting huge expansion ratio. The expanded sponge structure can take various forms. FIGS. 2A-2C show the various expanded cross-sections that the expandable sponge structure 1 can be. FIG. 2A shows a circular cross section, FIG. 2B shows a square cross section, and FIG. 2C show a triangular cross section. Any cross section can be used. The most important requirement is that it cannot escape from the aneurysm sac through a cell of the expandable tubular mesh structure 2 . The length of the expandable sponge structure 1 can vary as well. FIG. 3A shows a long continuous structure 1 . And FIG. 3B shows multiple short structures 1 .
One method of delivering the sponge filler 1 into the aneurysm sac is shown by the catheter-based delivery system in FIG. 4 . The catheter 4 can hold the compressed sponge 1 within its lumen, and when pushed out with the plunger 5 into the blood filled aneurysm sac, the sponge will expand out to a substantially larger size. The expanded size of the sponge filler is preferably larger than the largest opening of the tubular mesh is structure as to prevent the sponge from escaping the aneurysm sac. FIG. 5 shows an example of a curved delivery catheter 4 , where the tip is placed through a cell of the tubular mesh structure 2 and the expandable sponge structure 1 is being deployed into the aneurysm sac. It is important that the tip of the delivery catheter is through a cell of the tubular mesh structure into the aneurysm because the expandable sponge will expand very quickly after being exposed to the blood and being unconstrained by a catheter. FIG. 6 shows a method of ensuring that the delivery catheter's 4 tip stays inside the aneurysm sac by having a balloon 6 on the tip of it, and when inflated after the tip is within the aneurysm sac it will prevent the catheter tip from backing out of the aneurysm sac. FIG. 7A shows an expandable basket-like structure 7 and FIG. 7B shows an expandable braid-like structure 8 which are alternatives to having a balloon 6 on the tip of the catheter 4 .
The expandable tubular mesh structure 2 can be made of a metal or of a polymer. The versions made of a metal can be self-expanding from a smaller compressed state or balloon expandable from a smaller compressed or as-cut state. The self-expanding version may be made of metals which exhibit large amounts of elasticity (i.e. nickel-titanium, spring steel, MP-35N and elgiloy) such that when they are compressed down from their expanded state to the compressed state to load into a delivery catheter, they will substantially return to their expanded condition when released from the catheter. Alternatively, shape memory metals like nickel-titanium can be used to provide large expansion ratios. The balloon expandable version may be made of metals which exhibit large permanent deformations without significantly compromising the mechanical performance. The following are some common medical grade metals which are well suited for this purpose: stainless steel, titanium, tantulum, and martensitic nickel titanium. In either the self-expanding or the balloon expandable case, the intent is to deliver the expandable tubular mesh 2 to the target site in a smaller or compressed condition via a catheter-based delivery system so that the target site can be accessed through a remote vascular access point which is conducive to a percutaneous or minimally invasive approach.
The expandable tubular mesh structure 2 shown in FIGS. 1A, 1B, 1C, 5, and 6 represent a generic mesh structure. FIG. 8 shows an expandable tubular mesh structure where long continuous struts 9 are connected to anchoring end members 10 . This allows the structure to be very low in profile in the compressed state, and the durability of this type of structure can be optimized because no radial element exists in the longitudinal struts 9 . FIG. 9 show an alternate expandable tubular mesh structure preferably made from a polymer such as PTFE, Polyester, Polyurethane, and the like. The structure has relatively large holes 11 to give access to the expandable sponge delivery catheter. The ends incorporate an anchoring member 12 , either self-expanding or balloon expandable.
FIG. 10 shows a delivery catheter 4 which has been tracked over a guidewire 14 , which has been placed into the aneurysm sac through an opening 15 of an existing endoluminal stent-graft 13 which developed a leak. The balloon 6 on the delivery catheter 4 was inflated after the delivery catheter 4 was positioned within the aneurysm sac. FIG. 11 shows the guidewire 14 removed, and the expandable sponge structure 1 being delivered through the delivery catheter 4 .
FIG. 12 shows a section view of a tubular balloon graft 19 positioned across an infra-renal aortic aneurysm blocking off the flow to the aneurysm sac. The tubular balloon graft's 19 wall is made of an inner wall 16 , an outer wall 17 and a chamber 18 between them. The chamber 18 can be filled with various materials to dictate the mechanical properties of the prosthesis. FIG. 13 shows a bifurcated tubular balloon graft 20 positioned across an infra-renal aortic aneurysm with bi-lateral iliac involvement.
The tubular balloon implant can be made of the various biocompatible materials used to make balloon catheters. Those materials include P.E.T. (Polyester), nylon, urethane, and silicone. It can also be made of other implant grade materials such as ePTFE. One method of making such a device is to start with two thin walled tubes of differing diameters. The difference between the diameters of the tubes will dictate the volume of the balloon chamber. The ends of the tubes can be sealed together with adhesive or by heat to form the balloon chamber. A communication port will be necessary to be able to fill the port with the injected material.
The injected material can be an epoxy, a UV-curable epoxy, silicone, urethane or other type of biocompatible materials such as albumin, collagen, and gelatin glue which is injected into the balloon, and then cured in situ. Or, the injected material doesn't necessarily have to be cured. The as-delivered state may provide the appropriate mechanical properties for the application. Therefore, substances like sterile saline, biocompatible oils, or biocompatible adhesives can be left in the tubular balloon in the as-delivered state.
The tubular balloon graft can be non-porous to very porous. FIG. 14 shows a version where the tubular balloon graft has a porous outer wail 24 . The chamber 21 of the tubular balloon graft can be used to deliver an aneurysm sac filling substance such as UV curable adhesive 22 . The holes 23 which dictate the porosity of the tubular balloon graft can be created with laser drilling, etching, and other methods. The porosity can be varied in select areas of the graft. FIG. 15 shows a tubular balloon graft with only the ends of the graft have porosity to either promote cellular in-growth or to inject an adhesive which allows secure attachment of the graft ends to the vessel wall.
FIG. 16 shows a tubular balloon graft 19 which is being expanded from a folded condition (not shown) by a balloon catheter 25 . Once expanded, the chamber 18 of the tubular balloon graft 19 can be filled with the desired substance through the chamber access port 26 . FIG. 17 shows a tubular balloon graft 19 being expanded by an inflation process or filling the chamber 18 of the tubular balloon graft 19 through the chamber access port 26 .
FIG. 18 shows a version of the tubular balloon graft with an outer wall 17 which is substantially bulged out so that it fills some or all of the aneurysm sac. FIG. 19 shows a vascular graft 27 which has an integrated balloon 28 attached to the outside surface of the graft. The balloon can be pre-bulged and folded down for delivery, or it can be a very compliant material like silicone, urethane, or latex so that it has no folds whether compressed or expanded. FIG. 20A shows the same type of implant, a graft 27 with an external balloon 28 , used in a cerebral vessel aneurysm 29 . FIG. 20B show the same implant as 20 A, except that the implant balloon does not fully fill the aneurysm, which can be acceptable because the graft 27 excludes the aneurysm from the blood flow, and the primary purpose of the balloon 28 is to prevent migration of the graft 27 .
The graft 27 can be made of commonly used implant polymers such as PTFE, Polyester, Polyurethane, etc. The balloon 28 surrounding the graft can be made of the same commonly used vascular implant materials as well. The graft and balloon materials can be different, but it is commonly known that using the same material for both would facilitate processing/manufacturing. The theory is that the balloon 28 would preferentially only deploy into the aneurysm sac where the resistance to expansion is minimal as compared to the vessel wall. The graft 27 would provide the primary barrier between the pressurized blood and the thin wall of the aneurysm. Secondarily, the balloon itself provides a buffer from the pressurized blood. The balloon's 28 primary function, however, is to hold the graft 27 in place. Since the expanded section of the implant is “locked” into the aneurysm, the graft 27 should not migrate. Also, the balloon 28 , in the filled state, will provide hoop strength to the graft 27 .
FIGS. 21A-21E demonstrate one method of delivering a graft with an external balloon to the target site. FIG. 21A shows the implant loaded onto a balloon delivery catheter 30 with an outer sheath 32 and positioned over a guide wire 31 at the aneurysm target site. FIG. 21B shows that once in position, the outer sheath 32 is withdrawn. FIG. 21C shows the balloon delivery catheter 33 being inflated, pushing the implant 34 against the healthy vessel walls on both sides of the aneurysm. FIG. 21D shows that the balloon delivery catheter 30 may also have an implant balloon inflation port 35 which can now be used to fill up the implant balloon 28 with a biocompatible substance. The substance can be sterile saline, contrast agent, hydrogel, and UV cure adhesive to name a few. Most likely, low inflation pressures would be used to fill the implant balloon 28 . FIG. 21E shows that once the implant balloon 28 is filled, the implant balloon inflation port 35 can be detached and the delivery catheter 30 removed.
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The present invention relates to devices and methods for the treatment of diseases in the vasculature, and more specifically, devices and methods for treatment of aneurysms found in blood vessels. In a first embodiment of the present invention, a two part prostheses, where one part is an expandable sponge structure and the other part is an expandable tubular mesh structure, is provided. In the first embodiment, the expandable sponge structure is intended to fill the aneurysm cavity to prevent further dilatation of the vessel wall by creating a buffer or barrier between the pressurized pulsating blood flow and the thinning vessel wall. In the first embodiment, the expandable tubular mesh structure is placed across the aneurysm, contacting the inner wall of healthy vessel proximal and distal to the aneurysm.
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BACKGROUND OF THE INVENTION
The present invention pertains to a controlled release dosage form, based on a modified hydrophillic matrix composition.
Controlled release pharmaceutical dosage forms have received much attention in recent years and are highly desirable for providing a constant level of pharmaceutical agent to a patient over some extended period of time. The use of single or multiple unit dosage forms as controlled drug delivery devices encompasses a wide range of technologies and includes polymeric as well as nonpolymeric excipients. These dosage forms optimize the drug input rate into the systemic circulation, improve patient compliance, minimize side effects, and maximize drug product efficacy.
The use of controlled release products is frequently necessary for chronic drug administration, such as in the delivery of the calcium-channel blockers nifedipine and diltiazem and the beta-adrenergic blocker Propranolol in the management of angina and hypertension For delivery system design, physiochemical properties and intrinsic characteristics of the drug, such as high or low solubility, limited adsorption, or presystemic metabolism, may impose specific constraints during product development.
Advancements of extended release drug products have come about by the simultaneous convergence of many factors, including the discovery of novel polymers, formulation optimization, better understanding of physiological and pathological constraints, prohibitive cost of developing new drug entities, and the introduction of biopharmaceutics in drug product design.
One aspect of research about controlled-release delivery systems involves designing a system which produces steady-state plasma drug levels, which is also referred to as zero-order drug release kinetics. To meet this objective, numerous design variations have been attempted, and their major controlling mechanisms include diffusion/dissolution, chemical reactions, the use of osmotic pump devices, and multiple layer tablet designs, all of which incorporate numerous manufacturing steps and many associated drug release mechanisms. The complicated processes involved in the manufacture of such ultimately contributes to increased costs to the consumer.
One attractive design for potential zero-order drug release is the use of hydrophilic swellable matrices. Drug diffusion from the matrix is accomplished by swelling, dissolution and/or erosion. The major component of these systems is a hydrophilic polymer. In general, diffusivity is high in polymers containing flexible chains and low in crystalline polymers. With changes in morphological characteristics, the mobility of the polymer segments will change and diffusivity can be controlled. Addition of other components, such as a drug, another polymer, soluble or insoluble fillers, or solvent, can alter the intermolecular forces, free volume, glass transition temperature, and consequently, can alter the transport mechanisms. Cost is also a factor in these modified compositions. Still better controlled, time dependent drug release from these compositions is a continuing objective of research in this area, as is controlled diffusivity compositions which are more easily manufactured. Such compositions, which are more easily manufacturable, have the potential to lower cost of the dosage form.
SUMMARY OF THE INVENTION
The present invention is a new monolithic dosage form that delivers pharmaceutically active agents in a controlled release manner, and that is easy to manufacture. This dosage form, in a form such as a monolithic tablet, may approach zero order delivery of drugs which are either of high or low solubility. This dosage form or tablet is comprised of a hydrophilic swellable matrix, in which is disposed a pharmaceutically active agent and a salt The salt, either in combination with the drug or another salt upon reaction in an aqueous medium, causes a hardening reaction of the matrix. The rate of outward diffusion is controlled by exposing the product to an aqueous medium. This in turn causes a hardening reaction to occur in a time dependent manner from the outer boundaries towards the inner boundaries of the product; the hardened reaction product, in turn limits outward diffusion of the drug as the inward ingress of aqueous medium causes a progressive hardening from the outer boundaries of the dosage form or tablet in a direction towards the inner core there.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a graph showing the fractional release of diltiazem hydrochloride from tablets in accordance with Example 1 of the present invention and formulations A1-A5 of Table 1.
FIG. 2 is a graph showing the fractional release of diltiazem hydrochloride from tablets in accordance with Example 2 of the present invention and formulations B1-B5 of Table 2.
FIG. 3 is a graph showing the fractional release of diltiazem hydrochloride from tablets in accordance with Example 3 of the present invention and formulations C1-C5 of Table 3.
FIG. 4 is a graph showing the fractional release of diltiazem hydrochloride from tablets in accordance with Example 4 of the present invention and formulations D1-D5 of Table 4.
FIG. 5 is a graph showing the fractional release of diltiazem hydrochloride from the tablets in accordance with Example 5 of the present invention and formulations E1-E5 of Table 5.
FIG. 6 is a graph showing the fractional release of diltiazem hydrochloride from tablets in accordance with Example 6 of the present invention and formulations F1-F5 of Table 6.
FIG. 7 is a graph showing the fractional release of Propranolol HCl from tablets in accordance with Example 7 of the present invention and formulations G1-G2 of Table 7.
FIG. 8 is a graph showing the fractional release of Propranolol from tablets in accordance with Example 8 of the present invention and formulations H1-H2 of Table 8.
FIG. 9 is a graph showing the fractional release of Verapamil HCl from tablets in accordance with Example 9 of the present invention and formulations I1-I2 of Table 9.
FIG. 10 is a graph showing the fractional release of Verapamil HCl from tablets in accordance with Example 10 of the present invention and formulations J1-J2 of Table 10.
FIG. 11 is a graph showing the fractional release of diltiazem hydrochloride from tablets in accordance with Example 11 of the present invention and formulations K1-K2 of Table 11.
FIG. 12 is a graph showing the fractional release of diltiazem hydrochloride from tablets in accordance with example 12 of the present invention and formulations L1-L2 of Table 12.
FIG. 13 is a graph showing the fractional release of diltiazem hydrochloride from tablets in accordance with Example 13 of the present invention and formulations M1-M4 of Table 13.
FIG. 14 is a graph showing the fractional release of diltiazem hydrochloride from tablets in accordance with Example 14 of the present invention and formulation N1 of Table 14.
FIG. 15 is a graph showing the fractional release of Metoprolol from tablets in accordance with Example 15 of the present invention and formulations O1-O3 of Table 15.
FIG. 16 is a graph showing the fractional release of diltiazem hydrochloride from tablets using salt combinations of sodium bisulfate, potassium bicarbonate, magnesium sulfate, and calcium chloride.
FIG. 17 is a graph showing the fractional release of formulation A5 of the present invention during exposure to continuously changing pH levels.
FIG. 18 is a schematic representation depicting the dissolution of the floatable monolithic matrix tablet over time.
DETAILED DESCRIPTION OF THE INVENTION
The invention encompasses formulations for the controlled release, preferably zero order release, of bioactive material from a new monolithic system.
These formulations are based on simple swellable hydrodynamically balanced monolithic matrix tablet in which may be incorporated a range of water-soluble (low to high) bioactive drugs and salts. Extended or zero order release is accomplished through the novel application of polymeric matrix modification, as detailed below, by incorporating a salt in a swellable matrix:
As a tablet passes through the human digestive tract, it is subjected to pH values ranging from 1.5 to 7.4. The saliva of the mouth has a neutral pH, the stomach has a pH varying from 2.0-4.0, and the pH of the intestines carries a pH between 5.0-7.5. Therefore, it is important to consider the effects of this pH range on dissolution of a drug tablet. For a drug to approach zero-order release, it's dissolution must be independent of the pH in the surrounding environment.
Through processes of ionic interaction/complexation/molecular and/or self association between a drug and a salt or salt/drug combinations, homogeneously dispersed in a swellable polymer such as hydroxypropylmethylcellulose (HPMC), modify the dynamics of the matrix swelling rate and erosion of the swellable polymer, in accordance with variations in an external pH environment ranging from 1.5-7.0.
These interactions result in controlled matrix hardening. Such hardening is responsible for the control of polymer erosion/dissolution and drug release rates. By design, solvent penetrates the periphery of the tablet and a rapid initial interaction between drug and salt embedded in the polymeric matrix causes immediate hardening of the outer tablet boundary, the rate of hardening consistently decreases toward the center of the matrix core in a time-dependent manner over a long period of time (e.g. 24 hours).
The effervescent nature of sodium bicarbonate causes a generation of gas within the tablet and production of air bubbles. These air bubbles may result in floatation of the tablet, which may increase the gastric residence time of the tablet and result in a prolonged release of the drug in the acidic environment. In addition, this enhances the total mean gastrointestinal residence time and allows for increased biavailability. This is shown schematically in FIG. 18, where the tablet progresses over time from an intact and unswollen state to a floatable matrix which is loose and clear.
The differential rate of matrix hardening is the driving principle in the novel system of the present invention, which is dependent on and controlled by the rate of liquid ingress to the tablet core. With the simultaneous time-dependent decrease in gel layer integrity, the rate of drug diffusion decreases. This phenomenon compensates for the increase in diffusion path length and decrease in the surface area of the receding core which arises from the swelling property of the polymer. Hence, better controlled, preferably zero order, drug release is achieved. The drug release process can be tailored for up to 24 hours. Control of the changes in core hardness and synchronization of the rubbery/swelling front and described receding phase boundaries as well as erosion of the dissolution front boundary (i.e. erosion of the tablet periphery) results in controlled drug release, preferably including zero order kinetics. Optionally, polymer matrix hardenings is also easily achievable through double salt interaction. This binary salt combination is also uniformly dispersed in the polymeric matrix, which through ionic interaction/complexation/molecular and/or self association, increases the relative strength and rigidity of the matrix, resulting in controlled drug release with a similar mechanism to that described above.
Drugs such as the calcium-channel blockers Diltiazem and Verapamil and the beta-adrenergic blocker Propranolol (as the hydrochloride salts), with water solubilities of 50, 8 and 5% respectively, have been used in the present invention.
One hydrophilic matrix material useful in the present invention is HPMC K4M. This is a nonionic swellable hydrophillic polymer manufactured by "The Dow Chemical Company" under the tradename "Methocel". HPMC K4M is also abbreviated as HPMC K4MP, in which the "P" refers to premium cellulose ether designed for controlled release formulations. The "4" in the abbreviation suggests that the polymer has a nominal viscosity (2% in water) of 4000. The percent of methoxyl and hydroxypropryl groups are 19-24 and 7-12, respectively. In its physical form, HPMC K4M is a free-flowing, off-white powder with a particle size limitation of 90%<100 mesh screen. There are other types of HPMC such as K100LVP, K15MP, K100MP, E4MP and E10MP CR with nominal viscosities of 100, 1500, 100000, 4000, and 10000 respectively.
Formulations of the present invention may also include salts such as sodium bisulfate, potassium bicarbonate, magnesium sulfate, calcium chloride, sodium chloride, sodium sulfite and sodium carbonate in their formulations. FIG. 16 illustrates the use of some of these salts with diltiazem hydrochloride.
It is believed that an interaction between drug and salt forms a complex in the surrounding swellable matrix in a layered fashion because it occurs in a time-dependent manner as the solvent media for drug release penetrates the tablet inwardly. Likewise, because the catalyst for the initiation of drug release is liquid ingress, so too is the rate of drug release controlled by the inwardly progressive hardening of the salt complex.
A binary salt system (e.g. calcium chloride and sodium carbonate) may also be used, may also be used, in which case the hardening reaction may be a function of interaction between the salts. Calcium chloride may be incorporated to form a complex with sodium carbonate. With this combination, the reaction products are insoluble calcium carbonate and soluble channel former, sodium chloride. Hence the calcium carbonate embeds itself in the polymer matrix, initiates hardening and slowly dissolves with liquid ingress and the subsequent creation of diffusion channels as drug diffuses out. In a similar way, other binary salt combinations display time-dependent "hardening/de-hardening" behavior.
The amount of salt to be used may easily be determined, by those skilled in the art, taking into consideration the solubility of the drug, the nature of the polymer and the required degree of matrix hardening desired. In case of diltiazem hydrochloride in a HPMC matrix, 100 mg of sodium bicarbonate provides suitable matrix hardening for zero order controlled release, while in the case of the same amount of drug in a different polymer such as polyethylene oxide, 50 mg of sodium bicarbonate appears to be ideal for the attainment of controlled zero order release.
On the basis of the drug release profiles presented in FIG. 14, the change in pH of the dissolution media, from acidic to basic, does not markedly change the pattern except for a burst effect at pH≧5.4, which is not a limiting factor considering the fact that the tablet will not be immediately exposed to pH 5.4 in the gastrointestinal tract, and instead must first pass through the acidic gastric environment. This has been confirmed by subjecting the formulation (A5) to a carefully synchronized test of continuous changing pH environment simulating the gastrointestinal tract. This has been achieved with the aid of the Bio Dis Release Rate Tester (Vankel Instruments). The resulting drug release profile is provided in FIG. 17. The addition of salt in the formulation is not used as a pH modifying agent. Therefore, the relative salt proportion is essentially irrelevant with respect to changes in pH.
EXAMPLES
The formulations of the inventions are illustrated by the following examples. The use of particular polymers, buffers, and inert additive and fillers in the particular amounts shown are not intended to limit the scope of this invention but are exemplary only. All ingredients are initially individually massed and simultaneously incorporated. The premix is blended in a V-blender. The resultant homogeneous powder is compressed into tablets using conventional technologies.
Example 1
______________________________________FORMULATIONS FORMULATIONS (mg/tablet)INGREDIENTS A1 (ctrl) A2 A3 A4 A5______________________________________Diltiazem HCl 100 100 100 100 100HPMC K4M 200 200 200 200 200Sodium 0 10 50 75 100bicarbonateTOTAL 300 310 350 375 400WEIGHT OFTABLETDISSOLUTION CONDITIONSMedium: Potassium chloride buffer pH 1.5Volume: 900 mlApparatus: Rotating paddleRPM: 50______________________________________
As shown in FIG. 1 the results of this Example reflect a progressive decrease in the release of diltiazem hydrochloride with an increase in the sodium bicarbonate content within the HPMC matrix. This increase in salt content is accompanied by an increase in the linearity of the drug release profiles. In particular, formulation A5, which contains 100 mg of sodium bicarbonate provides drug release which most closely approaches zero order over a 24-hour period.
Example 2
______________________________________FORMULATIONS FORMULATIONS (mg/tablet)INGREDIENTS B1 (ctrl) B2 B3 B4 B5______________________________________Diltiazem HCl 100 100 100 100 100PEO 4M 200 200 200 200 200Sodium 0 10 50 75 100bicarbonateTOTAL 300 310 350 375 400WEIGHT OFTABLETDISSOLUTION CONDITIONSMedium: Potassium chloride buffer pH 1.5Volume: 900 mlApparatus: Rotating paddleRPM: 50______________________________________
This Example demonstrates, as depicted in FIG. 2, that salt induced controlled drug release is also observed with polyethylene oxide as the polymeric matrix. This suggests that the present invention is not polymer-limited. The linearity in profiles seen at even the lowest salt concentration, 10 mg. At higher concentrations (above 50 mg), the profiles tend to become concave, which suggests that the level of salt required for linear drug release is lower for polyethylene oxide than for HPMC.
Example 3
______________________________________FORMULATIONS FORMULATIONS (mg/tablet)INGREDIENTS C1 (ctrl) C2 C3 C4 C5______________________________________Diltiazem HCl 100 100 100 100 100HPMC K4M 200 200 200 200 200Sodium 0 10 50 75 100carbonateTOTAL 300 310 350 375 400WEIGHT OFTABLETDISSOLUTION CONDITIONSMedium: Potassium chloride buffer pH 1.5Volume: 900 mlApparatus: Rotating paddleRPM: 50______________________________________
Example 3 demonstrates and FIG. 3 illustrates that the suppression of diltiazem release from HPMC matrices can also be attained by the application of other salts such as sodium carbonate, and linearity of release rate is still observed.
Example 4
______________________________________FORMULATIONS FORMULATIONS (mg/tablet)INGREDIENTS D1 (ctrl) D2 D3 D4 D5______________________________________Diltiazem HCl 100 100 100 100 100PEO 4M 200 200 200 200 200Sodium 0 10 50 75 100carbonateTOTAL 300 310 350 375 400WEIGHT OFTABLETDISSOLUTION CONDITIONSMedium: Potassium chloride buffer pH 1.5Volume: 900 mlApparatus: Rotating paddleRPM: 50______________________________________
Example 4 demonstrates and FIG. 4 demonstrates that in using polyethylene oxide as the polymeric matrix, and sodium bicarbonate as the incorporated salt, an initial slow release followed by a more rapid linear release can be obtained. The initial slow release phase causes dilution of the drug in the gastric environment and subsequent reduction in gastrointestinal irritation.
Example 5
______________________________________FORMULATIONS FORMULATIONS (mg/tablet)INGREDIENTS E1 (ctrl) E2 E3 E4 E5______________________________________Diltiazem HCl 100 100 100 100 100HPMC K4M 200 200 200 200 200Potassium 0 10 50 75 100bicarbonateTOTAL 300 310 350 375 400WEIGHT OFTABLETDISSOLUTION CONDITIONSMedium: Potassium chloride buffer pH 1.5Volume: 900 mlApparatus: Rotating paddleRPM: 50______________________________________
As depicted in FIG. 5, Example 5 demonstrates the use of potassium bicarbonate as the incorporated salt. Linear retardation of drug release is observed after an initial burst phase corresponding to approximately 10% of the drug. This phenomenon has importance in the provision of a mini-loading dose prior to gradual metering of the drug which may be useful in some combinations.
Example 6
______________________________________FORMULATIONS FORMULATIONS (mg/tablet)INGREDIENTS F1 (ctrl) F2 F3 F4 F5______________________________________Diltiazem HCl 100 100 100 100 100PEO 4M 200 200 200 200 200Potassium 0 10 50 75 100bicarbonateTOTAL 300 310 350 375 400WEIGHT OFTABLETDISSOLUTION CONDITIONSMedium: Potassium chloride buffer pH 1.5Volume: 900 mlApparatus: Rotating paddleRPM: 50______________________________________
In this example, potassium bicarbonate is incorporated in a polyethylene matrix system. The result are seen graphically in FIG. 6. Suppression of drug release achieved while still maintaining a linear drug release. In addition, the suppression of drug release is virtually unchanged at salt concentrations beyond 50 mg/tablet.
Example 7
______________________________________FORMULATIONS FORMULATIONS (mg/tablet)INGREDIENTS G1 (ctrl) G2______________________________________Propanolol HCl 100 100HPMC K4M 200 200Sodium 0 100bicarbonateTOTAL 300 400WEIGHT OFTABLETDISSOLUTION CONDITIONSMedium: Potassium chloride buffer pH 1.5Volume: 900 mlApparatus: Rotating paddleRPM: 50______________________________________
This example, as depicted in FIG. 7, demonstrates that HPMC and sodium bicarbonate are a suitable combination for the release of drugs such as propranolol. The presence of sodium bicarbonate results in a substantial suppression of drug release, as compared to the use of HPMC alone.
Example 8
______________________________________FORMULATIONS FORMULATIONS (mg/tablet)INGREDIENTS H1 (ctrl) H2______________________________________Propanolol HCl 100 100PEO K4M 200 200Sodium 0 100bicarbonateTOTAL 300 400WEIGHT OFTABLETDISSOLUTION CONDITIONSMedium: Potassium chloride buffer pH 1.5Volume: 900 mlApparatus: Rotating paddleRPM: 50______________________________________
As depicted in FIG. 8, Example 8 demonstrates the use of potassium bicarbonate as the incorporated salt with polyethylene oxide as the polymeric matrix. Linear retardation of drug release is observed upon the addition of 100 mg of salt.
Example 9
______________________________________FORMULATIONS FORMULATIONS (mg/tablet)INGREDIENTS I1 (ctrl) I2______________________________________Verapamil HCl 100 100HPMC 200 200Sodium 0 100bicarbonateTOTAL 300 400WEIGHT OFTABLETDISSOLUTION CONDITIONSMedium: Potassium chloride buffer pH 1.5Volume: 900 mlApparatus: Rotating paddleRPM: 50______________________________________
The use of Verapamil HCl in the present invention is demonstrated in Example 9 and depicted in FIG. 9. As shown, the use of 100 mg of sodium bicarbonate results in a decreased rate of release of Verapamil HCl from a matrix. The formulations I1-I2 of Table 9 are particularly relevant in this regard.
Example 10
______________________________________FORMULATIONS FORMULATIONS (mg/tablet)INGREDIENTS J1 (ctrl) J2______________________________________Verapamil HCl 100 100PEO 4M: 200 200Sodium 0 100bicarbonateTOTAL 300 400WEIGHT OFTABLETDISSOLUTION CONDITIONSMedium: Potassium chloride buffer pH 1.5Volume: 900 mlApparatus: Rotating paddleRPM: 50______________________________________
Example 10 demonstrates and FIG. 10 illustrates that by selection of a suitable polymer for the matrix, a more controlled retardation of Verapamil hydrochloride may be effected. Although the release curve deviates from linearity toward concavity, such a profile is desirable when a slow onset of drug action is preferred. The concavity in release is evident only with polyethylene oxide. This is due to the sensitivity, in this combination, of the drug release profile to low salt content.
Example 11 (Comparative)
______________________________________FORMULATIONS FORMULATIONS (mg/tablet)INGREDIENTS K1 (ctrl) K2______________________________________Diltiazem HCl 100 100HPMC K4M 200 200Lactose 0 150TOTAL 300 450WEIGHT OFTABLETDISSOLUTION CONDITIONSMedium: Potassium chloride buffer pH 1.5Volume: 900 mlApparatus: Rotating paddleRPM: 50______________________________________
FIG. 11 is a graph of data from (Comparative) Example 11, showing the fractional release of diltiazem hydrochloride from hydrophillic matrix tablets in the absence of salt and with lactose as a salt substitute. The addition of 150 mg of lactose, as compared to the salt addition of other examples, resulted in no significant change in the release pattern. In this case the high solubility of diltiazem is the dominant factor in determining release rate.
Example 12
______________________________________FORMULATIONS FORMULATIONS (mg/tablet)INGREDIENTS L1 (ctrl) L2______________________________________Diltiazem HCl 100 100HPMC K4M 200 200Sodium 100 100bicarbonateLactose 0 150TOTAL 400 550WEIGHT OFTABLETDISSOLUTION CONDITIONSMedium: Potassium chloride buffer pH 1.5Volume: 900 mlApparatus: Rotating paddleRPM: 50______________________________________
In Example 12, as depicted in FIG. 12, compositions like those of Comparative Example 11 are modified by the addition of sodium bicarbonate. In each case, the formulations L1-L2 of Table 12 exhibit a more linear drug release rate, as compared to the control sample of Comparative Example 11. This illustrates that the presence of relatively large amounts of excipients such as lactose do not alter the principle of a drug release which is based on differential hardening rate within the matrix and in turn, results in a greater potential in formulation flexibility.
Example 13
______________________________________ FORMULATIONS (mg/tablet)FORMULATIONS Dilacor XR ®INGREDIENTS M1 (ctrl) M2 M3 M4*______________________________________Diltiazem HCl 240 240 240 240HPMC K4M 200 200 250 n/aSodium 0 100 100 n/abicarbonateTOTAL 300 310 350 936WEIGHT OFTABLET*Commercial multitablet, multilayer preparationDISSOLUTION CONDITIONS:Medium: Potassium chloride buffer pH 1.5Volume: 900 mlApparatus: Rotating paddleRPM: 50______________________________________
FIG. 13 is a graph showing the fractional release of diltiazem hydrochloride from the hydrophillic matrix tablets in accordance with Example 13 of the present invention and formulations M1-M4 of Table 13. The swellable, floatable monolithic tablet system, when formulated with a salt such as sodium bicarbonate (100 mg) exhibits a drug release profile which is similar to the commercial multilayer multitablet system of Dilacor® XR. Each commercial capsule of Dilacor® XR contains 4 three-layered tablets equivalent to 240 mg of Diltiazem hydrochloride.
Example 14
______________________________________FORMULATIONS FORMULATIONS (mg/tablet)INGREDIENTS N1______________________________________Diltiazem HCl 100HPMC K4M 200Sodium 100bicarbonateTOTAL 400WEIGHT OFTABLETDISSOLUTION CONDITIONSMedium: Potassium chloride buffer pH 1.5, Potassium phosphate buffers pH 5.4, 6, 6.4, and 6.8.Volume: 900 mlApparatus: Rotating paddleRPM: 50______________________________________
FIG. 14 demonstrates the influence of dissolution medium pH on the release of Diltiazem HCl. On exposure of the tablets to an increasingly basic environment, a more pronounced burst effect is observed, while still approaching a zero order drug release. Comparatively, a change in dissolution medium pH does not produce marked variation in drug release when compared to the release at pH 1.5.
Example 15
______________________________________FORMULATIONS FORMULATIONS (mg/tablet)INGREDIENTS O1 (ctrl) O2 O3______________________________________Metoprolol 100 100 100TartrateHPMC K4M 200 200 200Sodium -- 100 200bicarbonateCalcium -- 100 200chlorideTOTAL 300 500 700WEIGHT OFTABLETDISSOLUTION CONDITIONSMedium: Deionized water pH 5.5.Volume: 900 mlApparatus: Rotating paddleRPM: 50______________________________________
FIG. 15 illustrates the influence of double salt interaction on the control of the 100% water soluble drug, matoprolol tartrate. As the salt content is increased from 100 to 200 mg in both cases, there is a progressive decrease in drug release. This is indicative of an increase in matrix hardening when higher salt contents are used in the formulation, which in turn causes a slower drug release effect.
Example 16
______________________________________FORMULATIONS FORMULATIONS (mg/tablet)INGREDIENTS P1 P2 P3 P4______________________________________Diltiazem HCl 100 100 100 100HPMC K4M 200 200 200 200Sodium 100 0 0 0bisulfatePotassium 0 100 0 0bicarbonateMagnesium 0 0 100 0chlorideCalcium 0 0 0 100chlorideTOTAL 400 400 400 400WEIGHT OFTABLETDISSOLUTION CONDITIONS:Medium: Potassium chloride buffer pH 1.5Volume: 900 mlApparatus: Rotating paddleRPM: 50______________________________________
Example 16, as depicted in FIG. 16, demonstrates that controlled drug release may also be attained by the use of other salts. As a result, the formulation is not be restricted to sodium bicarbonate. The quantity of salt used dictates the degree of drug release suppression which approaches zero-order.
Example 17
______________________________________FORMULATIONS FORMULATIONS (mg/tablet)INGREDIENTS Q1 (ctrl) Q2______________________________________Diltiazem HCl 100 100HPMC K4M 200 200Sodium -- 100bicarbonateTOTAL 300 400WEIGHT OFTABLETDISSOLUTION CONDITIONSMedium: Row 1 - Potassium chloride buffer pH 1.5 (6 vessels) Row 2 - Potassium chloride buffer pH 3 (6 vessels) Row 3 - Potassium phosphate buffer pH 5.4 (6 vessels) Row 4 - Potassium phosphate buffer pH 6 (6 vessels) Row 5 - Potassium phosphate buffer pH 6.4 (6 vessels) Row 6 - Potassium phosphate buffer pH 6.8 (6 vessels)Duration spent by tablet in each row: Row 1 - 4 hours Row 2 - 0.5 hours Row 3 - 0.5 hours Row 4 - 6 hours Row 5 - 6 hours Row 6 - 7 hoursTotal duration of test: 24 hoursVolume of medium in each vessel: 220 mlApparatus: Bio Dis Release Rate Tester (Vankel Instruments)Dips per minute (dpm): 10______________________________________
Example 17, as depicted in FIG. 17, illustrates that by conducting one continuous test using media which simulates the gastrointestinal milieu as well as simulating the gastrointestinal transit time, the drug release from formulation Q2 maintains essentially a controlled zero-order release. This indicates that the formulation is relatively insensitive to changes in gastrointestinal pH.
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A swellable hydrophillic matrix tablet that delivers drugs in a controlled manner over a long period of time and is easy to manufacture. More specifically, the drug is disposed in a matrix composed of HPMC or polyethylene oxide, in the presence of a salt, which may be a combination of salts. Suitable salts include sodium bicarbonate, sodium chloride, potassium bicarbonate, calcium chloride, sodium bisulfate, sodium sulfite, and magnesium sulfate. Outward diffusion of the drug is controlled by an inwardly progressing hardening reaction between the salt and the dissolution medium, possibly also involving the drug itself.
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BACKGROUND OF THE INVENTION
The present invention relates to capturing exhaust gases and in particular to a bonnet for capturing exhaust gases from a railroad locomotive at rest or in motion at a slow speed.
Railroad locomotives generally have a large diesel engine coupled to a generator which provides power to drive motors attached to the locomotive's wheels. For example, a General Motors FP 59 diesel electric locomotive has a 12 cylinder main diesel engine producing approximately 3200 hp. The FP 59 locomotive also includes a second smaller 12 cylinder diesel engine for providing electricity for air conditioning, lights, kitchen facilities, and other auxiliary requirements of a train.
Substantial quantities of pollutants are produced by locomotives burning diesel fuels. The exhaust produced by an engine burning these fuels is a complex mixture of tens of thousands of gases and fine particulates. The particulates, which make up the commonly observed discharges known as soot or smoke, contain more than forty toxic air contaminants. The exhaust may include arsenic, benzene, and formaldehyde along with other ozone-forming pollutants that are components of smog and acid rain, such as sulfur dioxide (SO 2 ) and nitrogen oxides (NOx). Such contaminates create a substantial health risk to railroad workers and residents of surrounding communities and may physically damage structures and equipment.
Studies of diseases and health problems tied to air-borne pollutants, including various forms of cancer, have identified geographic clusters with occurrences of such diseases and health problems significantly higher than statistical norms. These geographic clusters have been shown to conform closely to the geographic distribution of emissions plumes from railroad yards and test facilities. Although these health issues have been identified, there is presently no effective system for capturing locomotive emissions in these areas.
BRIEF SUMMARY OF THE INVENTION
The present invention addresses the above and other needs by providing a bonnet which captures exhaust gases from the exhaust pipes of diesel-powered locomotives. The bonnet includes a shell with a compliant fender. One or more of the bonnets are positioned over the exhaust pipe or pipes of the locomotive and are secured to the exhaust pipes or to a top surface of the locomotive. The bonnets are connected to a manifold, and the manifold carries the exhaust gasses to an Emissions Control Unit (ECU) for processing. The bonnets enclose a volume above and/or around the exhaust pipes and the compliant fender closes against the internal or external surface of the exhaust pipe or pipes or against the top surface of the locomotive surrounding the exhaust pipe or pipes. The closing prevents or limits outside air from entering the bonnet and the exhaust gases from being emitted to the atmosphere.
In accordance with one aspect of the invention, there is provided a bonnet for use with a system for processing diesel locomotive exhaust. The system further includes an Emissions Control Unit (ECU) for processing locomotive exhaust and a manifold connected to the bonnet for carrying the exhaust from the bonnet to the ECU. The bonnet includes a shell for enclosing a volume around a locomotive exhaust pipe, a fender for closing out outside air, and a telescoping or compressing duct for allowing the bonnet to be lowered against a locomotive and raised away from the locomotive. The shell may include a compliant fender for closing out outside air from the shell and electromagnets may be included in the shell for holding the compliant fender against a roof of the locomotive.
In accordance with another aspect of the invention, there is provided a system for processing diesel locomotive exhaust. The system includes an Emissions Control Unit (ECU) for processing locomotive exhaust, a bonnet for capturing the locomotive exhaust, and a manifold connected to the bonnet for carrying the exhaust from the bonnet to the ECU. The manifold includes at least one parallel duct running parallel to train tracks and a connecting duct connecting the at least one parallel duct to the ECU. The parallel duct is supported by an overhead structure and is preferably approximately centered over the train tracks. The parallel duct includes a slot (or bottom gap) along the bottom of the parallel duct and running the length of the parallel duct. Seals reside along the slot and ordinarily close the slot to prevent the escape of exhaust or the entry of outside air. The bonnet includes a vertical duct connected to a duct transport unit slidably residing in or on the parallel duct, or connected to an extendable inner duct carried within the parallel duct. The duct transport unit is adapted to slide along the parallel duct and to open the seal as the duct transport unit slides to allow for motion of the locomotive. The extendable inner duct extends and retracts within the parallel duct to allow for motion of the locomotive.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein:
FIG. 1 is a locomotive suitable for use with the present invention.
FIG. 2 depicts a manifold system according to the present invention for collecting locomotive exhaust and carrying the exhaust to an Emissions Control Unit (ECU).
FIG. 3 shows a truck based manifold system according to the present invention for collecting locomotive exhaust and carrying the exhaust to an ECU.
FIG. 4 is a truck based manifold system according to the present invention for collecting locomotive exhaust and carrying the exhaust to a parallel duct connected to an ECU.
FIG. 5 shows a stationary manifold system according to the present invention for collecting locomotive exhaust and carrying the exhaust to an ECU.
FIG. 6 shows a mobile rail car based system according to the present invention for collecting locomotive exhaust and carrying the exhaust to an ECU mounted on the rail car.
FIG. 7 is a perspective view of a first embodiment of a bonnet for collecting locomotive exhaust according to the present invention.
FIG. 7A is a side view of the first bonnet.
FIG. 7B is a top view of the first bonnet and bonnet adjusting apparatus.
FIG. 7C is a side view of the first bonnet and the bonnet adjusting apparatus.
FIG. 8 is a cross-sectional view of the first bonnet taken along line 8 - 8 of FIG. 7A .
FIG. 9 is a top view of the bonnet.
FIG. 10 is a perspective view of a second embodiment of a bonnet according to the present invention.
FIG. 10A is a side view of the second embodiment of the bonnet.
FIG. 11 is a cross-sectional view of the second bonnet taken along line 11 - 11 of FIG. 10A .
FIG. 12 is a top view of the second bonnet.
FIG. 13A is a side view of a frame and hinge of the bonnet.
FIG. 13B is an end view of the frame and the hinge of the second bonnet.
FIG. 14A is a front view of the second bonnet adjusted to a first width.
FIG. 14B is an end view of the second bonnet adjusted to the first width.
FIG. 15A is a front view of the second bonnet adjusted to a second width.
FIG. 15B is an end view of the second bonnet adjusted to the second width.
FIG. 16A is a front view of the second bonnet adjusted to a third width.
FIG. 16B is an end view of the second bonnet adjusted to the third width.
FIG. 17 is a side view of a parallel duct according to the present invention.
FIG. 18A is a cross-sectional view of the parallel duct with a seal closing a slot (bottom gap), taken along line 18 - 18 of FIG. 17 .
FIG. 18B is a cross-sectional view of the parallel duct with a duct transport unit opening the slot by sliding seal elements aside, taken along line 18 - 18 of FIG. 17 .
FIG. 18C is a cross-sectional view of the parallel duct with a flap closing the slot, taken along line 18 - 18 of FIG. 17 .
FIG. 18D is a cross-sectional view of the parallel duct with the duct transport unit opening the slot by sliding the flap aside, taken along line 18 - 18 of FIG. 17 .
FIG. 18E is a cross-sectional view of the parallel duct with an extendable inner duct, taken along line 18 - 18 of FIG. 17 .
FIG. 18F is a cross-sectional view of the parallel duct with a vertical duct extending from the extendable inner duct, taken along line 18 - 18 of FIG. 17 .
FIG. 19 is a cross-sectional view of the parallel duct taken along line 19 - 19 of FIG. 18B , with the duct transport unit pushing the seal open.
FIG. 20 is a cross-sectional view of the parallel duct taken along line 20 - 20 of FIG. 18D , with the duct transport unit pushing the flap open.
FIG. 21 is a cross-sectional view of the parallel duct taken along line 21 - 21 of FIG. 18F , with sections of the extendable inner duct compressed or extended to accommodate the location and/or motion of the locomotive, and the vertical duct extending into the parallel duct.
Corresponding reference characters indicate corresponding components throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE INVENTION
The following description is of the best mode presently contemplated for carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing one or more preferred embodiments of the invention. The scope of the invention should be determined with reference to the claims.
The present invention comprises a bonnet for capturing diesel locomotive exhaust, and a system including the bonnet for capturing and processing the diesel exhaust. Recent studies of diseases and health problems tied to air-borne pollutants, including various forms of cancer, have identified geographic clusters with occurrences of such diseases and health problems significantly higher than statistical norms. These geographic clusters have been shown to conform closely to the geographic distribution of emissions plumes from railroad yards and test facilities. The present invention addresses a need for controlling emissions from diesel locomotives while stationary or moving slowly within a rail yard with engines idling or operating at low power (Notch 2) or while stationary in a locomotive test facility and operating at low or full power (to Notch 8) during load testing. By capturing and processing most or all of the exhaust gases for subsequent treatment, the exhaust intake bonnet and exhaust processing system of the present invention permits a significant reduction of particulate matter (PM), nitrogen oxides (NOx), sulfur dioxide (SO 2 ) and volatile organic compounds (VOCs). The present invention may further be utilized to reduce locomotive emissions resulting from port side loading and unloading of containers onto railcars at seaports, or from any activity wherein a locomotive resides in a small area for periods or time with the locomotive engine(s) running.
A similar problem is the emissions from ocean going vessels. U.S. patent application Ser. No. 10/835,197, filed Apr. 29, 2004 for “Maritime Emissions Control System,” and assigned to the assignee of the present invention, describes a maritime emissions control system which may be transported by barge or vessel to an Ocean Going Vessel (OGV) near or within a harbor. The maritime emissions control system captures and processes a main exhaust flow from the OGV to reduce emissions. The main exhaust flow may be from the OGV's engine(s), auxiliary engines, generators, and/or any other source of exhaust from the OGV. The '197 application is herein incorporated by reference.
U.S. patent application Ser. No. 10/941,731, filed Sep. 14, 2004 for “High Thermal Efficiency Selective Catalytic Reduction (SCR) System,” and assigned to the assignee of the present invention, describes an emissions control unit which transfers heat generated in one or more parts of the SCR system which generate heat to other parts of the SCR system which require heat. For example, heat stored in exhaust from a diesel generator is used to convert urea to ammonia used by the SCR system, and/or the diesel generator exhaust may be used to heat the main exhaust flow before entry into the SCR system. Additionally, a heat exchanger is used to transfer heat from a hot clean flow out of the SCR system to the main exhaust flow entering the SCR system. The '731 application is herein incorporated by reference.
US Patent Application filed on Mar. 28, 2005 titled “Air Pollution Control System for Ocean-Going Vessels,” and assigned to the assignee of the present invention, describes an emissions control unit having a first system adapted to receive a dirty flow and reduce Particulate Matter (PM) and Sulfur Dioxide (SO 2 ) in the dirty flow to produce a first processed flow from the first system and a second system adapted to receive the first processed flow and to reduce Oxides of Nitrogen (NO x ) in the first processed flow to produce a second processed flow from the second system. The first system and the second system are connected to serially process a gaseous flow to reduce PM, SO 2 , and NO x in the flow, and by first reducing the PM, SO 2 before the flow enters the NO x reducing system, the reliability and efficiency of the NO x reducing system is improved. The system further teaches the use of heat in exhaust from a diesel generator to convert aqueous ammonia, or urea, to ammonia for a selective catalytic reducer, thus reducing energy costs. The application filed Mar. 28, 2005 is herein incorporated by reference.
The present invention applies similar principles as described in the above incorporated patent applications to the control of emissions from a diesel locomotive 10 as shown in FIG. 1 . The locomotive 10 has at least one exhaust pipe 12 a for a main engine, and generally has a second exhaust pipe 12 b for an auxiliary engine, for example, for supplying power to train cars. Such locomotives 10 may produce a large volume of diesel exhaust while operating. When the locomotive 10 is traveling between destinations the diesel exhaust may be diluted into the air. However, when the diesel locomotive 10 is parked or moving slowly at a train station, at a port or other loading/unloading location, or at a test facility, a large amount of diesel exhaust may be released into a smaller area and present a health risk. This problem is compounded by the fact that locomotive engines are often left running for long periods of time versus stopping and restarting the engines.
A system according to the present invention for capturing and processing diesel locomotive exhaust is shown in FIG. 2 . The system includes a bonnet 48 (see FIGS. 7 and 10 ), an Emissions Control Unit (ECU) 18 , and a manifold for carrying the locomotive exhaust from the bonnet 48 to the ECU 18 . The manifold comprises a system of parallel ducts 32 a and connecting ducts 32 b . The parallel ducts 32 a and/or the connecting ducts 32 b are preferably supported by an overhead structure 33 . The parallel ducts 32 a run parallel to train tracks 22 , are preferably approximately centered above the train tracks 22 , and are high enough to allow the diesel locomotive 10 to run under the parallel ducts 32 a . Each parallel duct 32 a includes a slot (or bottom gap) 84 (see FIGS. 18A-18F ) running along (or parallel to) it's bottom and running substantially (may not extend to ends) the length of the parallel duct 32 a , and means for containing the captured exhaust in the parallel duct. The bonnet 48 includes or is attached to a telescoping vertical duct 16 (preferably comprising a flexible duct 16 within vertical duct supports 50 a and 50 b shown in FIG. 8 ) or a flexible vertical duct 70 (see FIG. 10 ). The vertical duct 16 or 70 is connected to a duct transport unit 82 slidably residing in the parallel duct 32 a (see FIGS. 18B , 18 D, 19 , and 20 ), or connected to an extendable inner duct 86 (see FIGS. 18F , and 21 ). The duct transport unit 82 is adapted to slide inside the at least one parallel duct 32 a and to open a seal 80 or 81 (see FIGS. 18B and 18D ) as the duct transport unit slides past, wherein the seal 80 , 81 closes behind the duct transport unit to allow for motion of the locomotive 10 . The extendable inner duct 86 extends and retracts within the parallel duct to allow for motion of the locomotive 10 .
A second embodiment of the system according to the present invention for capturing and processing diesel locomotive exhaust is shown in FIG. 3 . The second embodiment includes a truck 26 carrying a tower 28 and connecting ducts 32 b . Arms 30 extend from the tower 28 and duct supports 34 are attached to the arms 30 . Bonnet supports 36 also are attached to the arms 30 . The duct supports 34 support the connecting ducts 32 b and the bonnet supports 36 support and position the bonnets 48 over the exhaust pipes 12 a and 12 b (see FIG. 1 ). A flexible duct 32 c is connected between the truck 26 and the ECU 18 . The connecting ducts 32 b carry the diesel exhaust from the diesel locomotive 10 to the truck 26 , and the flexible duct 32 c carries the diesel exhaust from the truck 26 to the ECU 18 .
A third embodiment of the system according to the present invention for capturing and processing diesel locomotive exhaust is shown in FIG. 4 . The third embodiment includes the truck 26 carrying the tower 28 and the connecting ducts 32 b . The arms 30 extend from the tower 28 and duct supports 34 are attached to the arms 30 . The bonnet supports 36 also are attached to the arms 30 . The duct supports 34 support the connecting ducts 32 b and the bonnet supports 36 support and position the bonnets 48 over the exhaust pipes 12 a and 12 b (see FIG. 1 ). A second parallel duct 32 d resides substantially parallel and to the side of the train tracks 22 , and is connected to the ECU 18 . The parallel duct 32 d includes spaced apart hubs 14 . A flexible duct 32 c is connected between the truck 26 and one of the hubs 14 . The connecting ducts 32 b carry the diesel exhaust from the diesel locomotive 10 to the truck 26 , the flexible duct 32 c carries the diesel exhaust from the truck 26 to the hub 14 , and the parallel duct 32 d carries the diesel exhaust to the ECU 18 . The third embodiment may accommodate applications where the locomotive 10 is stationary and operating under low or full power such as in a locomotive test stand or facility.
A fourth embodiment of the system according to the present invention for capturing and processing diesel locomotive exhaust is shown in FIG. 5 . The fourth embodiment includes a base unit 38 supporting the tower 28 and the connecting ducts 32 b . The arms 30 extend from the tower 28 and duct supports 34 are attached to the arms 30 . The bonnet supports 36 also are attached to the arms 30 . The duct supports 34 support the connecting ducts 32 b and the bonnet supports 36 support and position the bonnets 48 over the exhaust pipes 12 a and 12 b (see FIG. 1 ). A fixed duct 32 e is connected between the base unit 38 and the ECU 18 , or the ECU 18 may reside next to the base unit 38 , or be integrated into the base unit 38 . The connecting ducts 32 b carry the diesel exhaust from the diesel locomotive 10 to the base 38 , and the fixed duct 32 e carries the diesel exhaust from the base 38 to the ECU 18 . The fourth embodiment may accommodate applications where the locomotive 10 is stationary and operating under low or full power such as in a locomotive test stand or facility.
A fifth embodiment of the system according to the present invention for capturing and processing diesel locomotive exhaust is shown in FIG. 6 . The fifth embodiment includes an ECU rail car 42 supporting the tower 28 and a boom 44 . The boom 44 may be pivotally or flexibly mounted to the tower 28 to allow for relative motion between the ECU rail car 42 and the locomotive 10 . The boom 44 is counter balanced by a counter weight 46 . The boom 44 extends over the locomotive 10 and duct supports 34 and bonnet supports 36 are attached to the boom 44 . The duct supports 34 support the connecting ducts 32 b and the bonnet supports 36 support and position the bonnets 48 over the exhaust pipes 12 a and 12 b (see FIG. 1 ). The connecting ducts 32 b carry the diesel exhaust from the diesel locomotive 10 to a second ECU 18 a adapted to reside on the ECU rail car 42 .
A perspective view of a first bonnet 48 a is shown in FIG. 7 . Vertical duct supports 50 a and 50 b support the vertical duct 16 . Bonnet supports 36 are attached to the shell 20 for raising and lowering the bonnet 48 a . The bonnet supports 36 may include, for example, cables, lever arms, gear mechanisms, and/or hydraulic mechanisms and are preferably cable. The vertical duct supports 50 a and 50 b are preferably telescoping structures. Contract members 59 a and 59 b cooperate to adjust the size of the shell 20 . A side view of the bonnet 48 a is shown in FIG. 7A .
A top view of the first bonnet 48 a and shell 20 adjusting apparatus is shown in FIG. 7B and a side view of the first bonnet 48 a and the shell 20 adjusting apparatus is shown in FIG. 7C . The shell adjusting apparatus includes a shell adjustment winch with split drums 51 mounted above the contracting members 59 a and 59 b . A shell adjustment cable 51 a is drawn or released by operation of the winch 51 . The cable 51 a is attached to both contracting members 59 a and 59 b and draws the contracting members 59 a and 59 b together to reduce the shell 20 size and to compress springs 51 b . The springs 51 b operate to expand the shell 20 when the cable 51 a is released by the winch 51 , thus urging the shell 20 to a larger size.
A cross-sectional view of the bonnet 48 a taken along line 8 - 8 of FIG. 7A is shown in FIG. 8 . The bonnet 48 a includes the shell 20 for enclosing a volume around the locomotive exhaust pipe 12 a or 12 b (see FIG. 1 ). A lower edge of the shell includes a first fender (or bumper) 56 a for closing against a top surface (or roof 10 a ) of the locomotive 10 , against an inside surface of one of the exhaust pipes 12 a or 12 b , or against an outside surface of one of the exhaust pipes 12 a or 12 b . The fender 56 a preferably is made from a compliant matrix (e.g., sponge like) material, and more preferably made of a high-temperature silicon foam, encasing a structural member 58 preferably made of carbon-reinforced epoxy or ester or of spring steel. The fender 56 a surrounds and captures the flexible structural member 58 and the electromagnets 54 and is sufficiently compliant so as to conform to the shape of the locomotive's roof 10 a . The fender 56 a also serves to close against the roof 10 a.
Contracting members 59 a and 59 b residing around the perimeter of the shell 20 may be contracted or adjusted to vary the size and/or shape of the shell 20 to accommodate various exhaust tube sizes and various extents of free-space fore and aft of the exhaust pipes 12 a and 12 b . The adjustment of size and/or shape of the shell 20 may be accomplished by compressing compliant walls of the shell 20 or by sliding surfaces in end panels of the shell 20 which telescope past one another, or by a combination of compliant walls and telescoping end panels. The bonnet 48 a may be held in place by one or more of gravity, friction, mechanical means or electro-magnetic force, and is preferably held in place by electro-magnets 54 .
The vertical duct 16 is attached to the shell 20 to carry diesel exhaust captured by the shell 20 to the parallel duct 32 a (see FIG. 2 ) or to the connecting duct 32 b (see FIG. 3 , 4 , 5 , or 6 ). The vertical duct 16 is preferably extendable and retractable to allow raising and lowering of the bonnet 48 a , and is more preferably a telescoping or a stretching duct to allow extension and retraction. An air foil 52 may be included to manage the orderly channeling of the flow of exhaust into the vertical duct 16 . The air foil 52 preferably resides at the entry into the vertical duct 16 , and flairs down and outward from the vertical duct 16 . The vertical duct used with the bonnet 48 a may alternatively be a flexible vertical duct 70 (see FIG. 10 ).
A top view of the bonnet 48 a is shown in FIG. 9 . The contracting member 59 may comprise telescoping members 59 a and 59 b which cooperate to adjust the perimeter of the shell 20 .
A perspective view of a second embodiment of a bonnet 48 b according to the present invention is shown in FIG. 10 . The bonnet 48 b comprises a tent 60 formed over and/or attached to a frame 62 . The frame 62 is connected to a hinge 68 preferably running along the peak of the frame. First cables 64 are attached to the hinge 68 and second cables 66 are attached to the frame 62 to provide vertical support to the hinge 68 and the frame 62 independently. The cables 64 , 66 may be independently raised and lowered, thereby causing the frame 62 to pivot about the hinge 68 , thereby widening and narrowing the frame 62 . A second compliant fender 56 b resides on a lower edge of the tent 60 . The tent 60 and the fender 56 b follow the widening and narrowing the frame 62 thereby widening and narrowing the tent 60 to accommodate the locomotive 10 . Magnets 54 reside in the fender 56 b or in the base of the tent 60 to hold the bonnet 48 b in place on the locomotive 10 . A side view of the bonnet 48 b is shown in FIG. 10A .
A cross-sectional view of the bonnet 48 b taken along line 11 - 11 of FIG. 10A is shown in FIG. 11 . The bonnet 48 b resides over the exhaust pipe 12 , thereby capturing exhaust from the locomotive 10 . A top view of the bonnet 48 b is shown in FIG. 12 . The bonnet 48 b includes telescoping (or overlapping) portions 55 which allow the bonnet 48 b to retain shape when the bonnet 48 b is adjusted to different widths. A side view of the frame 62 and hinge 68 is shown in FIG. 13A , and an end view of the frame 62 and the hinge 68 is shown in FIG. 13B .
A front view of the bonnet 48 b adjusted to a first width is shown in FIG. 14A , and an end view of the bonnet 48 b adjusted to the first width is shown in FIG. 14B . A front view of the bonnet 48 b adjusted to a narrower width is shown in FIG. 15A , and an end view of the bonnet 48 b adjusted to the narrower width is shown in FIG. 15B . A front view of the bonnet 48 b adjusted to a wider width is shown in FIG. 16A , and an end view of the bonnet 48 b adjusted to the wider width is shown in FIG. 16B . Thus, by adjusting the cables 64 and 66 , the bonnet 48 b may be adjusted as necessary to fit various locomotives. The ends of the tent 60 and fender 56 b may stretch, flex, or otherwise distort as necessary to allow the width of the tent 60 to be adjusted.
A side view of a portion of the parallel duct 32 a including a seal 78 is shown in FIG. 17 . A cross-sectional view of the parallel duct 32 a taken along line 18 - 18 of FIG. 17 is shown in FIG. 18A wherein the seal 78 comprises opposing tiles 80 closing the slot 84 of the parallel duct 32 a . A second cross-sectional view of the parallel duct 32 a taken along line 18 - 18 of FIG. 17 is shown in FIG. 18B with a duct transport unit 82 pushing the tiles 80 apart to open the slot 84 to create a moving opening for the vertical duct 16 (or 70 ).
A third cross-sectional view of the parallel duct 32 a taken along line 18 - 18 of FIG. 17 is shown in FIG. 18C wherein the seal 78 comprises two flaps 81 which extend from the sides of the gap 84 downward and towards each other so as to normally close against each other and thereby close the gap 84 . Because the pressure within the parallel duct 32 a is preferably slightly negative, this negative pressure will tend to close the flaps 81 against each other. If any over-pressure or surge of pressure occurs in the manifold system, the flaps 81 may separate and release the pressure. The flaps 81 will separate and close against the duct transport unit 82 as it passes as shown in FIG. 18D , closing behind the duct transport unit 82 after it passes.
A fifth cross-sectional view of the parallel duct 32 a taken along line 18 - 18 of FIG. 17 is shown in FIG. 18E with a portion of an extendable inner duct 86 closing the slot 84 . A sixth cross-sectional view of the parallel duct 32 a taken along line 18 - 18 of FIG. 17 is shown in FIG. 18F showing a portion of the extendable inner duct 86 including the vertical duct 16 wherein the vertical duct 16 (or 70 ) is shown extending through the slot 84 .
A cross-sectional view of the parallel duct 32 a taken along line 19 - 19 of FIG. 18B is shown in FIG. 19 . Interlocking tiles 80 a and 80 b are shown closing the slot 84 (see FIG. 18A ) before and after the duct transport unit 82 , and the tiles 80 a and 80 b are shown pushed apart by the duct transport unit 82 , but sealing against the duct transport unit 82 , in the portion of the parallel duct 32 a adjacent to the duct transport unit 82 . Thus, the gap 84 is closed solely by the tiles 80 a and 80 b before and after the duct transport unit 82 , and the gap 84 is closed by the cooperation of the tiles 80 a and 80 b with the duct transport unit 82 in the area occupied by the duct transport unit 82 . The vertical duct 16 (or 70 ) thereby passes between the tiles 80 a and 80 b and out of the parallel duct 32 a to the bonnet 48 to capture exhaust from the exhaust pipes 12 a , 12 b . Thus, the parallel duct 32 a allows motion of the duct transport unit 82 within the parallel duct 32 a while preventing the exhaust from escaping to the atmosphere or outside air from entering the parallel duct 32 a . Channels may be located within the duct transport unit 82 to constrain outward and inward movement of the tiles 80 a and 80 b . The channels may direct pins or wheels attached to the tiles.
A cross-sectional view of the parallel duct 32 a taken along line 20 - 20 of FIG. 18D is shown in FIG. 20 . The flaps 81 are closed against each other to close the slot 84 before and after the duct transport unit 82 (see FIG. 18C ), and are spread apart but closed against the duct transport unit 82 in the area adjacent to the duct transport unit 82 . The vertical duct 16 (or 70 ) thereby extends out of the parallel duct 32 a to the bonnet 48 to capture exhaust from the exhaust pipes 12 a , 12 b . Thus, the parallel duct 32 a allows motion of the duct transport unit 82 within the parallel duct 32 a while preventing the exhaust from escaping to the atmosphere or outside air from entering the parallel duct 32 a.
A cross-sectional view of the parallel duct 32 a taken along line 21 - 21 of FIG. 18F is shown in FIG. 21 . The extendable inner duct 86 is a linearly extendable duct which allows the vertical duct 16 (or 70 ) to translate along the parallel duct 32 a . The portions of the extendable inner duct 86 on either side of the vertical duct 16 (or 70 ) are generally to some degree compressed as shown by a heavily compressed portion 86 a , and a lightly compressed (or expanded) portion 86 b . The extendable inner duct 86 may also be somewhat stretchable.
Often, two or more locomotive engines are coupled, and a system having bonnets, ducts, and ECUs for processing locomotive exhaust simultaneously from two or more locomotives is intended to come within the scope of the present invention.
While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims.
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A bonnet captures exhaust gases from the exhaust pipes of diesel-powered locomotives. The bonnet includes a shell with a compliant fender. One or more of the bonnets are positioned over the exhaust pipe or pipes of the locomotive and are secured to the exhaust pipes or to a top surface of the locomotive. The bonnets are connected to a manifold, and the manifold carries the exhaust gasses to an Emissions Control Unit (ECU) for processing. The bonnets enclose a volume above and/or around the exhaust pipes and the compliant bumper closes against the internal or external surface of the exhaust pipe or pipes or against the top surface of the locomotive surrounding the exhaust pipe or pipes. The closing prevents or limits outside air from entering the bonnet and the exhaust gases from being emitted to the atmosphere.
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BACKGROUND OF THE INVENTION
The invention relates to wall construction and, in particular, to a wall system formed of an array of prefinished rectangular panels mechanically held on a wall framework.
PRIOR ART
It is known to construct a wall surface for a room or other structure with a plurality of prefinished rectangular panels. (As used herein, the term “rectangular” includes “square”.) Such constructions using a real wood veneer, for example, can achieve a custom high-quality appearance with moderate material and labor costs. Under varied circumstances, prior art panels such as those with a particle board core have exhibited a tendency to warp after installation. This warpage detracts from the appearance of the installation and if severe enough, can require remedial work. It is believed that warpage can be induced by moisture in adhesives used to hold the panels on a substrate or support wall and/or by different moisture levels between the front and rear faces of a panel where air circulation is limited at the back of the panels.
SUMMARY OF THE INVENTION
The invention provides a method and components for an improved wall construction of the type comprising an array of prefinished rectangular panels. In accordance with the invention, the panels are mechanically attached to a supporting wall frame or other structure and the attachment elements are arranged to constrain the panels against warpage.
In a preferred embodiment, the panels are stiffened by rigid runners, preferably made of suitable metal elements, extending substantially along the full length of their edges. The upper and lower edges of the panels are positively secured to the wall frame or other support structure by horizontal runners while the vertical panel edges are located to the wall frame indirectly by the close proximity of the ends of vertical runners to the horizontal runners.
More specifically, elongated panel mounting clips, preferably roll formed members of steel or other suitable metal, are factory attached to the rear or back side of each panel adjacent its upper and lower edges. The clips have a “Z”-like cross section to provide a flange that with the adjacent surface area of the panel forms a groove. These groove constructions at the top and bottom of a panel tightly receive flanges of corresponding main runners to fix the panel in its desired location on the wall framework.
As disclosed, the “Z” clips or brackets at the upper and lower panel edges are preferably at different offsets from their respective edges. This arrangement has the advantage of minimizing shipping bulk and, consequently, cost. The cross runners that stabilize the vertical panel edges in the disclosed embodiment are formed as splines that each tightly fit as a tongue into opposed grooves of adjacent panels. The cross runners or splines thus, in addition to reducing the tendency of the panel to warp also align the edges of adjacent panels to one another to improve the appearance of the installation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary perspective view of a wall constructed in accordance with the invention;
FIG. 2 is an enlarged end view of a main runner;
FIG. 3 is an enlarged end view of a cross runner and portions of adjacent panels;
FIG. 4 is a cross sectional view of the wall of FIG. 1 taken in a vertical plane;
FIG. 5 is a cross sectional view taken in a horizontal plane at an inside and an outside corner of a wall constructed like that of FIG. 1;
FIG. 6 is a cross sectional view taken in a horizontal plane of an end of a wall constructed like that of FIG. 1;
FIG. 7 is an end view of a plurality of panels stacked for shipment and/or storage;
FIG. 7A is a plan view on a reduced scale showing the rear face of a panel having clips mounted thereto;
FIG. 8 is an end view of an alternative main runner; and
FIG. 9 is an end view of an alternative cross runner.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, a wall system 10 constructed in accordance with the invention includes a plurality of rigid rectangular panels 11 attached to a wall support structure or framework 12 represented by vertical studs 13 covered by gypsum board or drywall 14 . The panels 11 are mechanically attached to the framework studs 13 with elongated clips 16 that grip horizontal runners 17 . Adjacent vertical edges of the panels 11 are mutually aligned by cross runners 18 .
The panels 11 , which can be identical for the most part, are an assembly of a flat, rigid board-like unit 19 and a pair of the clips 16 attached to a rear face 22 of the board 19 . A panel board 19 can comprise any suitable construction material and in the preferred embodiment comprises a laminate of two outer face layers 26 and 27 and an intermediate core 28 . The core can be commercially available particle board that consists primarily of wood particles bonded together with known materials. This particle board and similar cellulose based materials are particularly suited for the present invention since they afford both economy and adequate tensile and compressive strength. An exterior or front surface 29 of the face 27 typically has a final finish when it leaves the panel factory. For example, where the face or layer 27 is a wood veneer, it can be sanded, stained, and lacquered or otherwise prefinished before shipment from the factory where the panel 11 , as described, is manufactured. The panels 11 have nominal common face dimensions of, for example, 2 foot×2 foot square, or 2 foot high×4 foot wide. It will be understood, however, other suitable dimensions are envisioned.
Referring to FIGS. 7 and 7A, clips 16 fixed to the rear faces 22 of the panel board 19 can be roll formed sheet steel or aluminum, for example. In the illustrated construction, the clips 16 are identical at both the top and bottom edges of a panel board 19 and have a length equal to or slightly shorter than the horizontal length of the panel board. The cross section of a clip 16 , as shown in FIG. 7, is “Z”-shaped albeit somewhat shortened and broadened with generally planar flanges 31 , 32 and an intermediate web 33 . One flange 31 is secured against the panel board 19 either directly abutting it or adhered to it. The clips 16 are fixed to the rear panel face 22 with suitable means such as mechanical fasteners in the form of screws, staples or the like and/or an adhesive fastening medium. The other flange 32 has its edge remote from the web 33 bent outwardly slightly forming a lip 34 which facilitates assembly with a main runner 17 as explained below. At an upper edge 36 of a panel board 19 , the clip 16 is closely adjacent the edge while at a lower edge 37 the clip is adjacent but spaced a predetermined distance from this edge.
Vertical edges 38 of the panel boards 19 are provided with a groove 39 running their full length and preferably centered in the thickness of the board and having a round bottom to reduce any tendency of a stress induced fracture in this area. By way of example, the panel boards 19 can have representative thicknesses of ¾″, ⅝″, or ½″ with the thicker dimensions being preferred where greater strength is required. The grooves 39 can be ⅛″ wide and approximately {fraction (9/16)}″ deep.
The illustrated main horizontal runners 17 are extruded aluminum members with an irregular, asymmetrical cross section. This cross section, with particular reference to FIG. 2, includes a central channel section 41 with a web 42 and flanges 43 . The flanges have extended portions 44 , 46 that project oppositely of one another in a common plane parallel to but spaced from the plane of the web 42 . The main runner cross section also includes an extension 47 of a lower one of the flanges 43 . The extension has ribs 48 , 49 that are useful in gauging the vertical gap between adjacent panels 11 . The main runners 17 have a length preferably at least equal to the combined horizontal length of two panels 11 , and can be, for example, 8, 10 or 12 feet long.
FIG. 3 illustrates an end view of a cross runner 18 . As shown, the cross runner 18 has an irregular cruciform shape in section. One part 51 of the cruciform has corrugations 52 while another part 53 has ribs 54 , 55 . The illustrated cross runner 18 is made as an aluminum extrusion. The cross runners 18 have lengths generally equal to the vertical height of a panel 11 .
The panels 11 are installed on the wall support structure 12 by assembling a first row of panels 11 , typically starting at floor level, along the base of the supporting wall structure with a cross runner 18 assembled in the opposed vertical slots or grooves 39 of adjacent panels 11 . The horizontal spacing between the panels 11 is determined by abutting the panel edges 38 against the cross runner ribs 54 . The panels 11 are mechanically locked in position relative to the support structure 12 by positioning the lower flange portion or extension 46 of a main runner 17 into a groove or slot 56 formed by the clips 16 adjacent the upper edges 36 of the panel boards 19 and then securing the main runner to the support structure. In the illustrated case, this is accomplished by driving a self-tapping screw 61 through the web 42 into each of the studs 13 . A shallow groove 62 can be formed in the profile of the inside of the channel 41 to locate and stabilize the screw 61 as it is driven. The lower edges 37 of the first course or row of panels 11 can be secured to the support structure by suitable mechanical or adhesive means or other known fastening means. If desired, a “Z” strip with the proportions of the main runner channel 41 and upper flange portion or extension 44 can be used for this purpose. It should be understood that where desired, the main runners 17 can be secured directly to an open framework made up of studs or other elements not covered by gypsum board or other board material.
After a sufficient length of a main runner or runners 17 has been set and fixed to the wall support structure 12 with the lower flange area 46 received in the slot or groove 56 formed by the clips 16 and adjacent rear face areas 22 of the panel boards 19 , a second course or row of panels 11 is installed above the first row. This is accomplished by manipulating the panels 11 to cause the upper flange 44 of the main runner to be received in a slot or groove 57 formed between the lower clip 16 and the rear faces 22 adjacent the lower edges 37 of the second row of panels 11 . Each panel 11 is forced downwardly until the upper flange 44 of the main runner 17 is fully received in the groove 57 created between the clip 16 and panel board 19 and the lower edge 37 contacts the rib 48 of the main runner. As before, a cross runner 18 is inserted in the opposed vertical grooves 39 of adjacent panel boards 19 . When this second course of panels 11 has been put in place, the process of securing it to the wall structure with a main runner 17 at the upper panel edges 36 is repeated. In the same manner, subsequent rows or courses of panels 11 are positioned on the wall with cross runners 18 disposed between the panels and main runners 17 located at the lower and upper edges 36 , 37 of the panels. This process is repeated until the wall support structure 12 is covered by the panels 11 to the extent desired.
The effective thickness of the cross runner part 51 that is received in a groove 39 is proportioned to provide an interference with the groove to ensure a tight fit therewith. It will be seen that the cross runners 18 serve to align adjacent panel edges 38 to one another. As shown in FIG. 7, the clips 16 can be made with the flange 32 , in its free state, close to the rear face 22 so that a somewhat tight interference fit is achieved between this flange and the main runner flange 44 . Inspection of FIG. 4 reveals that the channel-like structure of the main runner 17 serves to space the panels 11 away from any subwall such as that represented by the gypsum board 14 . This spacing ensures that adequate air circulation exists around the panels so that any tendency of a differential in moisture content between the front and back of the panels 11 is reduced and, consequently, a tendency for the panels to warp from moisture conditions is reduced. It will be understood that panels such as the illustrated panels 11 , formed of wood or similar cellulose based materials, can be particularly susceptible to moisture-induced warping. The disclosed wall system 10 is effective in overcoming the problem of warpage of such panels since the main and cross runners 17 , 18 which are relatively rigid and free of moisture related warpage, engage substantially the full perimeter of each panel and serve to maintain the corresponding edges of the panel in a common plane thereby preventing visually distracting warpage.
FIG. 5 is a cross section of a wall system constructed in accordance with the invention taken in a horizontal plane to illustrate metal corner accessories 63 , 64 at inside and outside corners, respectively. The accessories, 63 , 64 can be aluminum extrusions and can include channel structures 66 , 67 to appropriately space the panels 11 from the subwall. FIG. 6 similarly illustrates an aluminum extrusion accessory 68 for the end of a wall.
With reference to FIG. 7, the offset of one of the clips 16 from its adjacent edge 37 allows a pair of panels 11 to be stacked rear face to rear face and offset clip to non offset clip so as to reduce the effective bulk of the panels and thereby reduce storage and shipping expense.
FIGS. 8 and 9 illustrate modified forms of a main runner 117 and a cross runner 118 . In these arrangements, a flange extension 147 and cruciform part 153 have channels 71 , 72 , respectively, which exist between edges of associated panels 11 and are adapted to receive the stem of a decorative strip having a T-shaped cross section as is known in the art.
It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited.
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A wall system comprising a plurality of rectangular rigid prefinished panels mounted on a wall support structure with main runners and cross runners. The main runners serve to lock the panels onto the support structure and with the cross runners serve to prevent the panels from warping due to adverse moisture conditions. The main runners are configured to space the panels from the wall support structure to encourage uniform humidity conditions at the front and rear of the panels. Clips that secure the panels to the main runners are fixed adjacent the top and bottom panel edges at different set-offs to obtain an advantageous nesting of panels for reduced packaging volume.
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This is a continuation-in-part application of application Ser. No. 08/052,453, filed Apr. 26, 1993, now abandoned, the entire contents of which is hereby incorporated by reference.
This invention relates to vehicle door panels and more particularly to improvements in methods for making vehicle door panels relating to the provision of bolsters on the surface thereof which face the interior of the vehicle when installed therein.
BACKGROUND OF THE INVENTION
There are two different methods for making panels herein contemplated, both of which result in a somewhat similar panel construction. The difference is that one method is capable of building into the panel more softness by including larger amounts of foamed material. Basically, this softer configuration is used in the more expensive luxury cars, whereas the other method is used basically in the large majority of other vehicles.
The method of making the luxury panel is essentially a two-stage process. In the first stage of the process, a substrate which is in the form of the panel is made by placing a fiberglass reinforcing mat in the lower half of a two-part mold and then filling the lower half of the mold with a foamable material such as liquid polyurethane capable of being cured into a foamed condition. After the foamable material has been inserted into the lower half of the mold, the upper half is moved down and then the foamable material is cured under heat to complete the substrate which is fairly rigid. In the second stage of the process, the substrate molded in the first stage is placed in the upper half of a second two-part mold. The lower part of the mold is in essence a vacuum mold. The second stage procedure is begun by moving a heated sheet of imperforate vinyl over the bottom part of the mold and then drawing by vacuum the heated sheet into the mold so that the three-dimensional configuration is formed on the vinyl. After the vinyl has been moved into engagement with the mold by the vacuum source, an amount of foamable material such as liquid polyurethane is then injected into the mold on top of the vinyl and thereafter the upper part of the mold which contains the substrate is then moved into cooperating relation with the lower part and the foamable material is cured into a relatively soft foamed condition.
The other more economical process is essentially a one-stage process which utilizes a two-part mold, the lower part of which again is a vacuum mold for the vinyl exterior sheet of the door panel to be made. In this case, the vinyl comes as the outer layer of a laminate which includes a layer of foamed material bounded thereto. The laminate is initially heated and then vacuum-drawn into the lower part of the mold. Next, a mat of fiberglass or similar reinforcing is placed inside the laminate vacuum adhered to the lower mold and, thereafter, a liquid polyurethane is added to the lower mold part over the vacuum-held laminate. The upper mold part is then closed and essentially a relatively rigid substrate is molded integrally with the vinyl laminate. In this process, it is not possible to provide much thickness and softness in the foam that is laminated with the vinyl or at least not as much as can be used in the second step of the two step process.
In the methods for making vehicle door panels herein contemplated, it has been the most widely accepted practice to make the door panels without bolsters and then add the bolsters to the panels after the vehicle panels have been made.
In both processes, the door panel that is made usually has a bolster added thereto in the area between the window sill portion and the arm rest portion and a rug section may be added to the lower portion below the arm rest portion. The bolster normally has a textile exterior mounted on a relatively rigid carrier. The bolster thus constructed must be adhered to the panel and must be edged in some fashion, often by a marginal trim strip or the like.
The addition of a bolster is so highly desirable from a decorative standpoint that the costs incident to its carrier construction and the necessity to adhere the bolster construction in place and to edge it somehow have generally been accepted. Nevertheless, there have been efforts undertaken to make the provision of one or more bolsters on a door panel more cost effective. Examples of various proposals are disclosed in the following U.S. Pat. Nos.: 4,740,417, 4,766,025, 4,923,539, and 5,091,031. Japanese patent publications 63-176132 and 62-211128 also provide examples.
The patent literature has suggested a procedure by which a trim insert is incorporated into the door panel during formation of the panel in a mold apparatus. For example, U.S. Pat. No. 4,923,539 discloses a molding method in which a textile insert is laminated onto a vinyl cover film with aid of nesting die. It is further disclosed that an adhesive is applied between the insert and the vinyl film to adheringly secure the vinyl to the insert. While a method of manufacturing a door panel in such fashion is more cost effective than the method in which an insert is added to the door panel after the panel has been made, the quality of the finished product and the cost-effectiveness of the method has been limited. More particularly, use of an unspecified adhesive to adhere the bolster material to the vinyl material may cause plasticizer migration between the vinyl and the adhesive, and resultant degradation of both. In addition, when an adhesive with a melting point which is too high is used, the adhesive will not be activated (become tacky) upon contact with the heated vinyl. If, on the other hand, the temperature activation range of the adhesive is too low, the adhesive may disintegrate before a temperature sufficient to soften vinyl and/or bolster material is reached. If the vinyl and/or bolster is not softened to the extent necessary, the desired amount of grain imprint therein will not be achieved, and part detail will be lost. Finally, if the thickness of the adhesive used is insufficient, the adhesive will not adequately perform its bonding function, nor will its imperforate nature be adequately employed to enable the porous textile outer layer of the bolster to be moved into conformity with a mold surface and retained therein by a vacuum communicated through openings in the mold surface. If the thickness of adhesive is greater than what is necessary, on the other hand, the expense associated with providing the adhesive will accordingly be unnecessarily high. Thus, there still exists a need to make the provision of a bolster on a door panel with optimized quality and cost-effectiveness.
SUMMARY OF THE INVENTION
It is an object of the present invention to fulfill the need expressed above. In accordance with the principles of the present invention, this objective is achieved by providing a method of making an interior panel of an automotive vehicle door having an exterior surface which is to face toward the interior of the automotive vehicle when installed therein which comprises the steps of forming a bolster laminate including a textile outer layer and a film inner layer which becomes tacky when heated provided by a polyurethane film of a thickness in the range of 2-4 mils and a melting point in the range of 220° F.-260° F., mounting the bolster laminate in a vacuum mold part having a mold surface shaped to define the exterior surface of the door panel with the outer layer engaging the mold surface, the thickness of the polyurethane film making the bolster laminate means sufficiently imperforate to enable the textile outer layer to be moved into conformity with the mold surface by application of a vacuum communicated through openings in the mold surface, heating a sheet of predetermined material content presenting a vinyl surface, vacuum forming the heated sheet in the vacuum mold part in such a way that the inner surface of the polyurethane film is raised to at least a temperature of 220° F. so as to be made tacky and that the vinyl surface bondingly interengages the vinyl surface of the heated sheet which engages a remaining portion of the mold surface of the vacuum mold part, and molding material between the vacuum mold part with the bolster laminate and the vinyl surface of the sheet engaged with the mold surface thereof and a cooperating opposed mold part to form an integrally molded panel having (1) an exterior surface in a shape corresponding with the shape of the mold surface of the vacuum mold part defined by the textile outer layer of the bolster laminate and the vinyl surface of the sheet other than the portion thereof bondingly interengaged with the bolster laminate, (2) an opposed surface of a shape corresponding in shape to a mold surface of the cooperating opposed mold part, and (3) a content between the exterior and opposed surfaces which includes a relatively hard substrate defining the opposed surface, a layer of sheet vinyl presenting the vinyl surface and a layer of relatively soft foamed material adjacent the layer of sheet vinyl. In this way, the costs heretofore encountered in constructing the bolster with a rigid carrier and of subsequently adhering the bolster construction to the finished panel are substantially reduced if not eliminated.
Preferably, the mold surface of the vacuum mold part on which the bolster laminate is mounted comprises a surface area bounded by a thin projecting peripheral lip having an interior surface extending from the surface area and an exterior surface from which the remaining mold surface extends. The bolster laminate is mounted on the mold surface area so that a marginal edge portion thereof lies along the interior surface of the peripheral lip. The vinyl surface which engages the exterior surface of the lip is biased by the relatively soft foamed material to abuttingly engage the marginal peripheral edge portion of the bolster laminate when removed from engagement with the lip after the molding procedure has been completed. In this way, the costs heretofore encountered in the edging of the bolster are substantially reduced if not eliminated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a completed vehicle door panel constructed in accordance with a two-stage method of the present invention;
FIG. 2 is a sectional view of a lower substrate mold part illustrating a step in the substrate forming stage of the two-stage method;
FIG. 3 is a sectional view of a substrate mold assembly including the lower part shown in FIG. 2 illustrating the completion of substrate forming stage of the two-stage method;
FIG. 4 is a sectional view of a vacuum mold part showing the beginning of the final molding stage of the two-stage method;
FIG. 5 is a sectional view of a final mold assembly including the vacuum mold part shown in FIG. 4 showing a further step of the final molding stage in the two-stage method;
FIG. 6 is a sectional view of a vacuum mold part showing a step in a one-stage method according to the present invention;
FIG. 7 is a sectional view similar to FIG. 6 showing the completion of the vacuum forming step of the one-stage second method;
FIG. 8 is a sectional view similar to FIG. 7 showing the start of the substrate forming step of the one-stage method; and
FIG. 9 is a sectional view of the mold assembly including the vacuum mold part shown in FIGS. 6, 7 and 8 showing the completion of the substrate forming step of the one-stage method.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now more particularly to the drawings, there is shown in FIG. 1 a vehicle door panel, generally indicated at 10, made by a two-stage method according to the principles of the present invention. The door panel 10 includes a window sill upper portion 12 and an arm rest portion 14 defining therebetween a bolster receiving portion 16. A lower planar rug receiving portion 18 having a rug section 19 adhered thereto is disposed below the arm rest portion 14.
Various steps in the two-stage method of the present invention for making the panel are shown in FIGS. 2-5. The first stage is a substrate forming stage wherein a substrate 20 is made. It will be understood that in the broadest aspects of the present invention the first stage and second stage need not be performed continuously or at the same location. The substrate 20 made in the first stage is used in the second stage and hence the process of the second stage may merely acquire substrates from others.
The substrate 20 may be formed in any known manner with any known material. Characteristically, the substrate 20 is a fairly rigid structure which may be formed of wood fiber or any of the known synthetic materials, such as polyethylene, polypropylene, polyvinyl chloride and polyurethane. FIGS. 2 and 3 illustrate steps in the formation of a substrate 20 utilizing polyurethane foam. As shown in FIG. 2, there is provided a lower mold part 22 of a substrate mold assembly, generally indicated at 24 in FIG. 3, which includes a mold surface 26 within which a fiberglass reinforcing mat 28 is mounted. Thereafter, a foamable polyurethane liquid material 30 is added to the reinforcing mat mounted within the mold surface 26. This addition is schematically illustrated by the feed pipe 32 in FIG. 2. After a full layer of foamable polyurethane material 30 has been added within the lower mold part 22, a cooperating upper mold part 34 of the substrate mold assembly 24 is moved downwardly into cooperating relation with the lower mold part 22 and the materials 28 and 30 mounted in the mold surface 26 thereof. The upper mold part 34 includes a downwardly facing mold surface 36 which is complementary to the shape of the interior surface of the finished panel 10. The interior surface of the panel is hidden within the door when the panel 10 is installed in the vehicle. The foamable polyurethane material 30 is then cured at a temperature within 300°-340° F. A typical thickness of the formed substrate 20 is approximately 31/2 millimeters.
The second stage of the process, as illustrated in FIGS. 4 and 5, is a final molding stage and involves the utilization of a final mold assembly, generally indicated at 38 in FIG. 5, which includes a lower mold component or part 40 which is of the vacuum-forming type. The lower mold part 40 is shown in FIG. 4 as including a mold surface 42 and two vacuum openings 44 and 45 extending therefrom to two suitable sources of vacuum (not shown). The mold surface 42 is shaped to provide essentially the exterior surface of the panel 10 which when the panel is mounted in a vehicle door faces the interior of the vehicle.
It will be noted that the mold surface 42 includes a bolster receiving portion 46 which is defined by a thin projecting peripheral lip 48. FIG. 4 illustrates the first step in the second final molding stage of the method and, in this initial step, a bolster laminate 50 is initially prepared for mounting on the portion 46 of the mold surface 42 defined by the peripheral lip 48. The bolster laminate 50 includes a textile outer layer. The textile outer layer may be of any suitable configuration and material as, for example, a knitted, woven, non-woven or otherwise formed textile fabric made from monofilaments and/or staple filaments of one textile material or of different textile materials including synthetic and natural materials such as cotton, wool, silk, linen, polyester, nylon, rayon, polyethylene, polypropylene, vinyl, and blends and mixtures thereof. In a preferred embodiment of the present invention, the textile layer is formed of a synthetic thermoplastic material, as for, example, polyester and the mold surface portion 46 has an appropriate design, such as the embossed squares 51, provided therein which can be imparted by molding under heat and pressure to the textile outer layer of thermoplastic material of the bolster laminate 50.
The bolster laminate 50 includes a flexible imperforate layer and an inner surface, each made from polyurethane which becomes tacky when heated by bringing a sheet of heated vinyl at a temperature of between 300° and 340° F. near and into contact therewith. While the polyurethane imperforate layer and surface may be provided by separate layers, preferably they are provided together in a single film structure. The polyurethane used for the bolster is to have a melting point in the range of 220°-260° F., and a thickness of the range of 2-4 mils. The polyurethane film performs both the function of rendering the porous textile outer layer capable of being moved into conformity with a mold surface and retained therein by a vacuum communicated through openings to the mold surface and the function of providing a normally non-tacky surface which is made tacky and bonds to the hot vinyl when brought near and into contact therewith.
The use of polyurethane film for an adhesive is advantageous because it does not cause plasticizer migration between the adhesive and the vinyl. As a result, degradation of the vinyl and adhesive is prevented. In addition, using a polyurethane film with a melting point in the range of 220°-260° F. is advantageous in that the film will become tacky when brought into contact with the heated vinyl at a temperature between 300° and 340° F., without the polyurethane film's being degraded, and while enabling a proper amount of vinyl and/or bolster softening to permit adequate grain imprint and part detail. In addition, the minimum thickness of about 2 mils is required to sufficiently enable the polyurethane film to achieve its bonding function, as well as its function of enabling the bolster to be moved into conformity with the mold surface. On the other hand, the upper limit of about 4 mils should not be exceeded in order to conserve material costs.
If desired, the bolster laminate 50 may also include an intermediate layer which preferably is of a foamed material. The foamed material is preferably relatively soft, as compared with the relatively hard foamed polyurethane forming the substrate 20, and may be of polypropylene, polyethylene, polyvinyl chloride, polyurethane or the like. Here again, a preferred material is polyurethane.
In the embodiment shown in FIG. 1, there is only a single unitary bolster laminate 50 utilized. However, it will be understood that more than one bolster laminate 50 may be utilized and may be positioned in the exterior surface of the door panel 10 in areas other than the bolster receiving portion 16 previously described.
As shown in FIG. 4, the first step in the second stage of the process is to mount the bolster laminate 50 in the bolster receiving portion 46 of the mold surface 42 of the vacuum mold part 40. The bolster laminate 50 is mounted so that the outer textile surface engages the mold surface portion 46 and a marginal edge portion of the bolster laminate 50 extends along the inwardly facing surface of the peripheral lip 48. It is noted that the second set of vacuum openings 45 communicate with the bolster receiving portion 46. The separate vacuum source is communicated with the openings 45 to draw the outer surface of the bolster laminate 50 into engagement with the mold surface portion 46 and retain it thereon.
Next, a sheet of vinyl 52 is provided which has a surface area sufficient to cover the mold surface 42 which turns upwardly along its periphery. A typical thickness for the vinyl sheet 52 is 1 millimeter. The vinyl sheet 52 is heated as, for example, to a temperature within the range of 300°-340° F. and then fed onto the mold surface 42 of the mold part 40 including onto the exposed inner surface of the bolster laminate 50. As the heated vinyl sheet 52 is drawn by the other vacuum source communicating with the vacuum openings 44 into conformity with the mold surface 42, the heat of the vinyl sheet 52 will likewise heat the inner surface of the bolster laminate 50 rendering the surface tacky. It has been found that, by simply applying the vacuum and drawing the heated vinyl sheet 52 into the mold surface 42, the interengagement of the heated vinyl sheet 50 with the tacky film surface of the bolster laminate 50 and the pressure that is applied between these two surfaces will effect a substantial intimate bond which does not require any further implementation. It will be understood that the tacky characteristic of the inner surface acts as an adhesive in effecting the intimate bond between the vinyl sheet 52 and bolster laminate 50. Moreover, it can be seen that, as the heated vinyl sheet 52 conforms to the portions of the mold surface 42 which are beyond the periphery of the bolster laminate 50, there will be a marginal edge surface thereof which contacts the exterior surface of the peripheral lip 48.
With the heated vinyl sheet 52 vacuum formed in the mold part 40, the substrate 20 which had been preformed in the first stage is mounted on a cooperating mold part 54 of the final mold assembly 38 as shown in FIG. 5. The mold part 54 has a mold surface 56 which conforms in shape with the mold surface 36 of the substrate mold part 34. The mold surface 56 is therefore complementary with the shape of the interior surface of the substrate 20 and the latter is mounted in the mold part 54 so that its interior surface engages the mold surface 56.
Next, a foamable material 58, which is preferably a foamable liquid polyurethane, is added, as indicated at 60 in FIG. 5, onto the surface of the vinyl sheet 52 which is opposite from the mold surface 42 of the vacuum mold part 40. When the foamable material 58 has been sufficiently distributed over the vacuum formed vinyl sheet in mold part 40, the upper cooperating mold part 54 with the substrate 20 adhered to the mold surface 56 thereof is then moved into cooperating relation with the lower mold part 40.
Thereafter, the foamable material 58 is foamed and cured under heat as, for example, within the range of 100° to 160° F., into a relatively soft foamed condition between the substrate 20 and the vacuum formed vinyl sheet 52 having the bolster laminate 50 intimately bonded to the exterior surface thereof.
The panel 10 thus molded is then removed from the mold assembly 38. In this regard, it will be noted that the marginal edge of the heated vinyl contacting the exterior surface of the lip 48 will be backed by foamed material 58. Consequently, as the panel is removed from contact with the mold surface 42 of the mold part, the spacing between the surface of the vinyl sheet 52 contacting the exterior of the lip 58 and the surface of the bolster laminate 50 contacting the interior of the lip 58 which are spaced apart by the presence of the lip 58 during molding will be biased by the foamed material backing the vinyl sheet into engagement with one another so that the edge of the bolster lamina which shows on the exterior surface of the panel 10 is well defined by the juncture between the interengaged marginal portions of the vinyl sheet 52 and bolster laminate 50. Moreover, the interengaged extent of the marginal portions is such that it is not essential to very accurately determine the exact position of the actual edge of the bolster laminate 50 since the exact position of the actual edge is hidden within the panel and does not show.
After the panel 10 is removed from the mold assembly 38, the rug section 19, when desired, can be adhered to the lower planar portion 18 of the panel 10 by any suitable adhesive.
Referring now more particularly to FIGS. 6-9, these figures illustrate the steps in a one-stage method according to the principles of the present invention for making a door panel similar to the door panel 10 previously described. The door panel without the added rug section 19 is shown in cross-section in FIG. 9 and designated by the reference numeral 110.
The one-stage method utilizes a mold assembly, generally indicated at 112, which is similar to the mold assembly 38 previously described. The mold assembly 112 includes a lower mold part or component 114, which, like the mold part 40, is a vacuum forming mold component having a mold surface 116 and two sets of vacuum openings 118 and 119 extending from the mold surface 116 to two separate sources of vacuum (not shown). The mold surface 116 like the mold surface 42 previously described includes a portion, indicated at 120, which is positioned to form the bolster receiving portion of the panel 110 and is communicated with the set of vacuum openings 119.
The bolster receiving mold surface portion 120, like the mold surface portion 46 previously described, is defined by an upstanding peripheral lip 122 similar to the lip 48 previously described. As before, a bolster laminate 124 is provided. The bolster laminate 124 is constructed in the manner previously described and is mounted so that its textile outer layer engages the mold surface portion 120 and a marginal edge portion thereof engages the peripheral lip 122. As before, communication of a source of vacuum with the set of vacuum openings 119 draws and maintains the outer surface of the bolster laminate 124 in engagement with mold surface portion 120.
It can be seen that the lower vacuum mold part 114 is thus prepared in a manner similar to the vacuum mold part 40 onto which the heated vinyl sheet 52 is formed. In the one-stage method embodiment, a vinyl sheet 126 is provided. However, it forms an outer layer of a laminated sheet, generally indicated at 128, which includes a layer of relatively soft foam material 130 bounded thereto which may be provided by many different materials as, for example, polypropylene, polyethylene, polyester, polyvinyl chloride, and polyurethane. A preferred embodiment is polyurethane. The intermediate layer 130 may have a thickness of, for example, 31/2 millimeters.
As before, the laminated sheet 128 is heated to a temperature within the range of 300° to 340° F. and then vacuum formed onto the mold surface 116 and the inner layer of the bolster laminate 124 to intimately bond with the latter in the manner previously described. FIG. 7 illustrates the condition of the laminate sheet 128 after the vacuum forming step has been completed.
The remaining steps of the one-stage method are steps which are taken to essentially mold a substrate 134 onto the exposed surface of the foamed material layer 130 of the laminate sheet 128 which is vacuum formed onto the lower mold part 112. FIG. 8 shows the preferred steps of forming the substrate 134 which includes the initial mounting of a fiberglass reinforcing mat 136 over the film surface and then adding a foamable material 138, preferably foamable polyurethane liquid, schematically illustrated at 140, in FIG. 8.
Once the polyurethane foamable material has been added within the mold part 114, a cooperating mold part or component 142 of the mold assembly 112 is moved into cooperating relation with the lower vacuum mold part 114. The mold part 140 has a mold surface 142 which is shaped to define the interior surface of the panel 110. Thereafter, the foamable polyurethane material 138 is foamed and cured under heat within the range of 100°-160° F. The curing results in a relatively rigid substrate 134 of foamed polyurethane with the fiberglass reinforcing mat embedded therein, similar to the starting substrate 20 made in the first stage of the two-stage method previously described.
It can be seen that the resultant panel 110 which is removed from the mold assembly 112 is similar to the panel 10 prior to the adherence of the rug section 19 thereto. The basic difference between the two panels is that the vinyl sheet 126 which forms the exterior surface of the panel 110, except for the exterior surface provided by the bolster laminate 124, is backed by a uniform thickness of soft foamed material 130 whereas, in the case of the panel 10, the soft foam material 58 may be thicker in areas where softness is particularly desired and need not be of uniform thickness. It will also be understood that the panel 110 can have a rug section 19 suitably adhered to the lower portion thereof in the same manner as the panel 10.
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A method of making an interior panel of an automotive vehicle door having an exterior surface which is to face toward the interior of the automotive vehicle when installed therein which comprises the steps of forming a bolster laminate including a textile outer layer, a flexible imperforate layer and an inner surface layer of a material which becomes tacky when heated, mounting the bolster laminate in a vacuum mold part, heating a sheet of predetermined material content presenting a vinyl surface, vacuum forming the heated sheet in the vacuum mold part so that the vinyl surface bondingly interengages the tacky material of the film inner layer of the bolster laminate, molding material between the vacuum mold part with the bolster laminate and the sheet therein and a cooperating opposed mold part to form an integrally molded panel having a content between an exterior bolster and vinyl surface and an opposed surface which includes a relatively hard substrate defining the opposed surface, a layer of sheet vinyl presenting the vinyl surface and a layer of relatively soft foamed material adjacent the layer of sheet vinyl.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is directed to a TONG BEARING and in particular, to a machinable TONG BEARING that may be reconditioned for multiple uses and an extended useful life.
[0003] 2. Description of the Prior Art
[0004] Tong systems are utilized in the oil well industry for attaching to and tightening various types of rods and tubing. Such tongs are utilized with a backup system that holds one element while a second element is gripped by the tong and rotated to connect and disconnect the two elements.
[0005] A typical tong includes a housing around a gripping portion of the tong, with a gripping portion being driven and rotating relative to the housing. Conventional tongs utilize a series of bearing elements to facilitate rotational movement with less friction and wear. Such rollers, ball bearings or other conventional bearings are subject to the harsh conditions encountered at a well or drilling site. Therefore, such single use conventional bearings are subject to wear and/or failure, requiring frequent replacement. Moreover, in order to ensure smooth and continuous operation, multiple bearings are required at multiple positions spaced apart on both the top and bottom of the tong housing around the gripping assembly. The maintenance and replacement of the large number of bearings is both time consuming and expensive. Moreover, the maintenance required and high rate of failure can cause extended down time for the tong, affecting reliability, causing additional delays and adding to operational costs.
[0006] It can be seen then that a new and improved bearing system is needed for tongs. Such a bearing system should eliminate the large number of bearings and small parts currently needed. Moreover, the bearing system should provide for greater reliability and less down time. Such a bearing should be easily removed and interchanged with other bearings. Moreover, the utility of such a bearing is improved if a bearing element can be reconditioned and used again. The present invention addresses these as well as other problems associated with tong bearings.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to a tong bearing, and in particular to a renewable tong bearing. The tong includes a housing and drive elements as well as a gripping portion. The bearing includes an upper bearing element and a lower bearing element. Each of the bearing elements includes a generally rounded planar base portion and may include an open end or is closed to form a center opening. An inner annular raised portion is spaced radially outward from the center opening and extends downward from the base for an upper bearing element and upward from the base for a lower bearing element. An outer annular raised portion is adjacent the inner raised annular portion and extends downward from an upper bearing element and upward for a lower bearing element in somewhat tiered configuration. Outer walls form a lip around the outer annular raised portion and engage one another when the upper and lower bearing elements are placed aligned on top of one another. The bearing elements also include a flattened end portion forming a planar wall extending vertically and forming an opening when the upper and lower bearing elements are placed together for receiving drive train elements extending between motors and the gripping portion.
[0008] The bearing elements are renewable and are made of a low friction material that is suitable for machining. Therefore, when the bearing elements develop flaws or become worn, the elements may be removed, the surfaces refinished and placed back into the tong for further use. When the satisfactory surfaces are again achieved, the bearing elements may be reused. To make up for lost thickness, shims may be placed in the tong housing and provide sufficient thickness for the bearing.
[0009] The large single bearing eliminates the need for a high number of rollers or individual bearing elements and also provides for renewing and reusing the bearing elements. Moreover, the machinable material provides a low friction surface while also providing for refurbishing the elements to extend the useful life of the bearing. The exact configuration and geometry may be varied depending upon the type of tong and its application. Moreover, the upper and lower bearing elements may be mirror images of one another, or for some applications the bearing may need a dedicated upper element and a dedicated lower element. Moreover, depending upon the gripping portion and tong used, the raised portions and/or the outer lip may or may not be required. In some embodiment, lubrication channels are formed in the bearing to facilitate the spread of lubricants.
[0010] These features of novelty and various other advantages that characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and the objects obtained by its use, reference should be made to the drawings that form a further part hereof, and to the accompanying descriptive matter, in which there is illustrated and described a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Referring now to the drawings, wherein like reference letters and numeral indicate corresponding structure throughout the several views:
[0012] FIG. 1 is an exploded top perspective view of a tong housing with the top of the housing removed with a bearing according to the principles of the present invention;
[0013] FIG. 2 is a top perspective view of the bearing and the tong housing shown in FIG. 1 ;
[0014] FIG. 3 is a top plan view of the bearing and the tong housing shown in FIG. 1 ;
[0015] FIG. 4 s a bottom plan of the bearing and housing shown in FIG. 2 ;
[0016] FIG. 5 is a top perspective view of an upper bearing element for the bearing shown in FIG. 1 ;
[0017] FIG. 6 s a bottom plan view of the upper bearing element shown in FIG. 5 ;
[0018] FIG. 6A s a bottom plan view of an alternate embodiment of the upper bearing element;
[0019] FIG. 7 is a side elevational view of the upper bearing element shown in FIG. 5 ;
[0020] FIG. 8 is a top plan view of the upper bearing element shown in FIG. 5 ;
[0021] FIG. 9 is a side sectional view through the bearing and tong housing shown in FIG. 1 ;
[0022] FIG. 10 is an exploded view of the tong housing and bearing shown in FIG. 1 with shims added;
[0023] FIG. 11 is a side sectional view of the tong housing and bearing shown in FIG. 10 ;
[0024] FIG. 12 is a perspective view of a second embodiment of a bearing element according to the principles of the present invention;
[0025] FIG. 13 s a bottom plan view of the bearing element shown in FIG. 12 ;
[0026] FIG. 14 is a side elevational view of the bearing element shown in FIG. 12 ;
[0027] FIG. 15 is a top plan view of the bearing element shown in FIG. 12 ;
[0028] FIG. 16 is a perspective view of the bearing element shown in FIG. 12 and a portion of the housing.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] Referring now to the drawings and in particular to FIGS. 1-4 , there is shown a tong 100 according to the principles of the present invention. The tong 100 is shown as an open face tong with an open end 110 but it can be appreciated that the present invention is also applicable for closed face tongs as explained hereinafter. The tong 100 includes a tong housing 102 and a bearing 104 . The tong housing 102 is shown with the top cover portion removed for clarity. In addition, the tong 100 includes various drive elements such as may be described in U.S. Pat. No. 8,281,691, entitled TONG ASSEMBLY, which is incorporated herein by reference. By modifying the shape and/or dimensions, the bearing of the present invention can be adapted for use with other types of tongs. The housing 102 includes a drive section 106 and a gripper section 108 . The tong housing 102 includes a base 112 and an outer wall 114 . The gripper section of the housing 108 also includes a curved wall portion 116 providing for rotation of gripping elements to manipulate tube or rod elements. The curved wall portion 116 also forms an opening to the drive section 106 of the tong housing 102 to permit insertion of drive train elements extending from the drive section 106 to the gripping elements and the bearing section 108 . This arrangement is also shown for a closed head tong in FIG. 16 , described herein below.
[0030] As shown in FIGS. 1 and 2 , the bearing 104 includes an upper bearing element 120 and a lower bearing element 140 . The bearing elements 120 and 140 are configured for engaging one another at their periphery along an intermediate horizontal plane to form the bearing 104 . In the embodiment shown, the upper bearing element 120 is identical to the lower bearing element 140 . Therefore, the elements 120 and 140 may be interchanged and a supply of a single type of replacement bearing elements may be used without requiring a dedicated top or bottom element. However, in other embodiments the upper bearing element may have a different configuration than the lower bearing element.
[0031] Referring to FIGS. 5-9 , the upper bearing element 120 is shown. It can be appreciated however that upper bearing element 120 is identical to the lower bearing element 140 in the embodiment shown and the upper bearing element 120 may simply be flipped over to provide a lower bearing element 140 . Although only the upper bearing element 120 will be described, other than orientation, the description applies equally to the lower bearing element 140 . The bearing element 120 includes a base 122 and defines an open end 124 . The open end 124 leads to a center open portion 126 . The center opening 126 is configured for receiving gripping elements that engage rods, tubing and other elements to be gripped and rotated. Spaced radially outward from the inner edge of the base 122 of the center open portion is an inner annular raised portion 128 . The raised portion 128 extends downward for an upper bearing element 120 and an inner annular raised portion 148 extends upward for a lower bearing element 140 . An outer annular raised portion 130 is adjacent and radially outward from the inner annular raised portion 128 . The outer annular raised portion 130 extends downward further than the inner annular raised portion 128 for an upper bearing element while an outer annular raised portion 150 extends upward for a lower bearing element 140 . An outer wall 132 forms a lip that extends yet further downward than the outer annular raised portion 130 on the upper bearing element 120 . An outer wall portion 152 for a lower bearing element 140 extends upward and is configured to engage the outer wall portion 132 of the upper bearing element 120 . The outer wall portions 132 and 152 therefore form a vertically continuous curved wall when the bearing is assembled. The base 122 , the inner annular raised portion 128 , the outer annular raised portion 130 and the outer wall 132 form a terraced surface on the underside of the upper bearing element 120 . The bearing elements 120 and 140 are generally annular but include a flattened end portion 134 . The end portion 134 forms a planar vertical surface with an opening 136 to provide access for tong drive train elements that insert through the opening 136 . This arrangement is seen more clearly in FIG. 16
[0032] In a configuration mirroring the upper bearing element 120 , the lower bearing element 140 also includes a bearing base 142 , an open end 144 , forming an open center 146 . The lower bearing element 140 includes an inner annular raised portion 148 situated next to an outer annular raised portion 150 and an outer wall 152 . The lower bearing element includes a flattened end portion 154 and a drive train access opening 156 . Therefore, the base 142 , the inner annular raised portion 148 , the outer annular raised portion 150 and the outer wall 152 form a terraced surface on the top of the lower bearing element 140 .
[0033] The bearing 104 operates in a very harsh environment and is subject to wear. However, the bearing elements 120 and 140 are Phenolic type bearings made of a durable, yet low friction machinable material. The bearing 104 may be made from a laminated plastic material that may include dry lubrication compounds. Suitable Phenolic bearing materials are available from ScanPac Mfg., Inc. of Menomonee Falls, Wis. Therefore, the bearing 104 may be removed and the elements 120 and 140 machined if necessary to maintain smooth bearing surfaces. If too much thickness is lost, one or more shims 160 may be inserted against the base 122 and/or the base 142 , as shown in FIGS. 10 and 11 . The shims 160 are also made of a durable low friction material and maintain an appropriate height for the bearing 104 . Use of shims extends the life of the bearing and provides for reuse of bearing elements rather than a single use and disposal of the bearing elements.
[0034] For some applications, further lubrication may be utilized. As shown in FIG. 6A , the bearing element 120 may be configured to include one or more lubrication channels 180 , 182 and 184 . In the configuration shown, a lubrication channel 180 is formed in the outer annular raised portion 130 , a lubrication channel 182 is formed in the inner annular raised portion 128 and a lubrication channel 184 is formed in the base 122 . It can be appreciated that fewer and more channels may be utilized for different bearings and for some applications. Moreover, the lubrication channels may be located and oriented in different configurations to facilitate distribution of lubricants to various places requiring additional lubrication.
[0035] As shown in FIGS. 12-15 , a second embodiment is shown of a bearing 200 suitable for use with a closed face tong. The bearing element 200 , shown as an upper bearing element in FIG. 12 , may be reversed for use as a lower bearing element. However, in some applications the upper and lower bearing elements may have a different configuration. The closed face bearing element 200 includes a base 202 forming a center opening 204 . The closed face bearing element 200 includes an outer wall 206 that extends from both ends of a flattened vertically planar portion 208 . The flattened portion 208 provides an opening 210 to receive a gear 118 , as shown in FIG. 16 . The closed face bearing 200 also includes alignment holes 212 through the base 202 . As with the open face tong bearing 104 , the closed face tong bearing 200 is configured so that the edges of the outer wall 206 meet and form a continuous curving outer wall portion when the upper bearing element and the lower bearing element are set together.
[0036] It may also be appreciated that a machinable bearing may take other similar configurations for use with multiple types of tongs used throughout the industry. Moreover, the shims may also be configured differently to accommodate for the different sizes and applications for the tong bearings.
[0037] It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
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A renewable bearing is for a tong including a housing and an engagement assembly. The bearing has a monolithic upper bearing element having a substantially planar upper surface and a monolithic lower bearing element having a substantially planar lower surface. The upper and lower bearing elements are configured to mount inside the housing with a substantially same outer horizontal profile as the upper bearing element. The upper bearing element and the lower bearing element define a central open area. The upper bearing element and the lower bearing element have an inner section define a radial recess opening to the central opening and for receiving the engagement assembly. The upper bearing element and the lower bearing element have outer sections that form a bearing portion radially intermediate the engagement assembly.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. application Ser. No. 11/713,180, entitled “Dry Powder Inhaler with Aeroelastic Dispersion Mechanism,” filed on Mar. 2, 2007, pending, which claims the benefit of priority of U.S. provisional application No. 60/778,878, entitled “Dry Powder Inhaler with Aeroelastic Dispersion Mechanism,” filed on Mar. 3, 2006, the contents of both of which are incorporated herein by reference in their entirety.
TECHNICAL FIELD
[0002] The present invention is directed generally to inhalers, for example, dry powder inhalers, and methods of delivering a medicament to a patient. More particularly, the present invention is directed to dry powder inhalers having an aeroelastic dispersion mechanism.
BACKGROUND
[0003] Dry powder inhalers (“DPIs”) represent a promising alternative to pressurized meted dose inhaler (“pMDI”) devices for delivering drug aerosols without using CFC propellants. See generally, Crowder et al., 2001: an Odyssey in Inhaler Formulation and Design, Pharmaceutical Technology, pp. 99-113, July 2001; and Peart et al., New Developments in Dry Powder Inhaler Technology, American Pharmaceutical Review, Vol. 4, n,3, pp. 37-45 (2001). Martonen et al. 2005 Respiratory Care, Smyth and Hickey American Journal of Drug Delivery, 2005.
[0004] Typically, the DPIs are configured to deliver a powdered drug or drug mixture that includes an excipient and/or other ingredients. Conventionally, many DPIs have operated passively, relying on the inspiratory effort of the patient to dispense the drug provided by the powder. Unfortunately, this passive operation can lead to poor dosing uniformity since inspiratory capabilities can vary from patient to patient, and sometimes even use-to-use by the same patient, particularly if the patient is undergoing an asthmatic attack or respiratory-type ailment which tends to close the airway.
[0005] Generally described, known single and multiple dose DPI devices use: (a) individual pre-measured doses, such as capsules containing the drug, which can be inserted into the device prior to dispensing; or (b) bulk powder reservoirs which are configured to administer successive quantities of the drug to the patient via a dispensing chamber which dispenses the proper dose. See generally, Prime et al., Review of Dry Powder Inhaler's, 26 Adv. Drug Delivery Rev., pp. 51-58 (1997); and Hickey et al., A New Millennium for Inhaler Technology, 21 Pharm. Tech., n. 6, pp. 116-125 (1997).
[0006] In operation, DPI devices desire to administer a uniform aerosol dispersion amount in a desired physical form (such as a particulate size) of the dry powder into a patient's airway and direct it to a desired deposit site. If the patient is unable to provide sufficient respiratory effort, the extent of drug penetration, especially to the lower portion of the airway, may be impeded. This may result in premature deposit of the powder in the patient's mouth or throat.
[0007] A number of obstacles can undesirably impact the performance of the DPI. For example, the small size of the inhalable particles in the dry powder drug mixture can subject them to forces of agglomeration and/or cohesion (i.e., certain types of dry powders are susceptible to agglomeration, which is typically caused by particles of the drug adhering together), which can result in poor flow and non-uniform dispersion. In addition, as noted above, many dry powder formulations employ larger excipient particles to promote flow properties of the drug. However, separation of the drug from the excipient, as well as the presence of agglomeration, can require additional inspiratory effort, which, again, can impact the stable dispersion of the powder within the air stream of the patient. Unstable dispersions may inhibit the drug from reaching its preferred deposit/destination site and can prematurely deposit undue amounts of the drug elsewhere.
[0008] A number of different inhalation devices have been designed to attempt to resolve problems attendant with conventional passive inhalers. For example, U.S. Pat. No. 5,655,523 discloses and claims a dry powder inhalation device which has a deagglomeration-aerosolization plunger rod or biased hammer and solenoid. U.S. Pat. No. 3,948,264 discloses the use of a battery-powered solenoid buzzer to vibrate the capsule to effectuate the efficient release of the powder contained therein. Those devices are based on the proposition that the release of the dry powder can be effectively facilitated by the use of energy input independent of patient respiratory effort.
[0009] U.S. Pat. No. 5,533,502 to Piper discloses and claims a powder inhaler using patient inspiratory efforts for generating a respirable aerosol. The Piper invention also includes a cartridge capable of rotating, holding the depressed wells or blisters defining the medicament holding receptacles. A spring-loaded carriage compresses the blister against conduits with sharp edges that puncture the blister to release the medication that is then entrained in air drawn in from the air inlet conduit so that aerosolized medication is emitted from the aerosol outlet conduit.
[0010] Crowder et al. describe a dry powder inhaler in U.S. Pat. No. 6,889,690 comprising a piezoelectric polymer packaging in which the powder for aerosolization is simulated using non-linear signals determined a priori for specific powders.
[0011] In recent years, dry powder inhalers (DPIs) have gained widespread use, particularly in the United States. Currently, the DPI market is estimated to be worth in excess of $4 billion. Dry powder inhalers have the added advantages of a wide range of doses that can be delivered, excellent stability of drugs in powder form (no refrigeration), ease of maintaining sterility, non-ozone depletion, and they require no press-and-breathe coordination.
[0012] There is great potential for delivering a number of therapeutic compounds via the lungs (see, for example, Martonen T., Smyth H D C, Isaccs K., Burton R., “Issues in Drug Delivery: Dry Powder Inhaler Performance and Lung Deposition”: Respiratory Care. 2005, 50(9); and Smyth H D C, Hickey, A J, “Carriers in Drug Powder Delivery: Implications for Inhalation System Design,” American Journal of Drug Delivery, 2005, 3(2),117-132). In the search for non-invasive delivery of biologics (which currently must be injected), it was realized that the large highly absorptive surface area of the lung with low metabolic drug degradation, could be used for systemic delivery of proteins such as insulin. The administration of small molecular weight drugs previously administered by injection is currently under investigation via the inhalation route either to provide non-invasive rapid onset of action, or to improve the therapeutic ratio for drugs acting in the lung (e.g. lung cancer).
[0013] Gene therapy of pulmonary disease is still in its infancy but could provide valuable solutions to currently unmet medical needs. The recognition that the airways may provide a real opportunity for delivering biotech therapeutics in a non-invasive way was recently achieved with Exubera™, an inhaled insulin product. This product has obtained a recommendation for approval by US Food and Drug Administration and will lead to expanded opportunities for other biologics to be administered via the airways.
[0014] Key to all inhalation dosage forms is the need to maximize the “respirable dose” (particles with aerodynamic diameters<5.0 μm that deposit in the lung) of a therapeutic agent. However, both propellant-based inhalers and current DPI systems only achieve lung deposition efficiencies of less than 20% of the delivered dose. The primary reason why powder systems have limited efficiency is the difficult balancing of particle size (particles under 5 μm diameter) and strong inter-particulate forces that prevent deaggregation of powders (strong cohesive forces begin to dominate at particle sizes<10 μm) (Smyth H D C., Hickey, A J., “Carriers in Drug Powder Delivery: Implications for inhalation System Design,” American Journal of Drug Delivery, 2005, 3(2), 117-132). Thus, DPIs require considerable inspiratory effort to draw the powder formulation from the device to generate aerosols for efficient lung deposition (see FIG. 1 for an illustration of typical mechanism of powder dispersion for DPIs). Many patients, particularly asthmatic patients, children, and elderly patients, which are important patient groups for respiratory disease, are not capable of such effort. In most DPIs, approximately 60 L/min of airflow is required to effectively deaggregate the fine cohesive powder. All currently available DPIs suffer from this potential drawback.
[0015] Multiple studies have shown that the dose emitted from dry powder inhalers (DPI) is dependent on air flow rates (see Martonen T., Smyth H D C, Isaccs K., Burton R., “Issues in Drug Delivery: Dry Powder Inhaler Performance and Lung Deposition”: Respiratory Care. 2005, 50(9)). Increasing air-flow increases drug dispersion due to increases in drag forces of the fluid acting on the particle located in the flow. The Turbuhaler® device (a common DPI), is not suitable for children because of the low flow achieved by this patient group (see Martonen T., Smyth H D C, Isaccs K., Burton R., “Issues in Drug Delivery: Dry Powder Inhaler Performance and Lung Deposition”: Respiratory Care. 2005, 50(9)).
[0016] Considerable intra-patient variability of inhalation rates has been found when patients inhale through two leading DPI devices. That inherent variability has prompted several companies to evaluate ways of providing energy in the inhaler (i.e. “active” DPIs). Currently, there is no active DPI commercially available. The active inhalers under investigation include technologies that use compressed air, piezoelectric actuators, and electric motors. The designs of those inhalers are very complex and utilize many moving parts and components. The complexity of those devices presents several major drawbacks including high cost, component failure risk, complex manufacturing procedures, expensive quality control, and difficulty in meeting specifications for regulatory approval and release (Food and Drug Administration).
[0017] Alternatively, powder technology provides potential solutions for flow rate dependence of DPIs. For example, hollow porous microparticles having a geometric size of 5-30 μm, but aerodynamic sizes of 1-5 μm require less power for dispersion than small particles of the same mass. This may lead to flow independent drug dispersion but is likely to be limited to a few types of drugs with relevant physicochemical properties.
[0018] Thus there are several problems associated with current dry powder inhaler systems including the most problematic issue: the dose a patient receives is highly dependent on the flow rate the patient can draw through the passive-dispersion device. Several patents describing potential solutions to this problem employ an external energy source to assist in the dispersion of powders and remove this dosing dependence on patient inhalation characteristics. Only one of these devices has made it to market or been approved by regulatory agencies such as the US Food and Drug Administration. Even upon approval, it is likely that these complex devices will have significant costs of manufacture and quality control, which could have a significant impact on the costs of drugs to patients.
[0019] The present disclosure describes exemplary dry powder inhalers and associated single or multi-dose packaging, which holds the compound to be delivered for inhalation as a dry powder. These dry powder inhalers bridge the gap between passive devices and active devices. The inhalers are passive devices that operate using the energy generated by the patient inspiratory flow inhalation maneuver. However, the energy generated by airflow within the devices is focused on the powder by using oscillations induced by airflow across an aeroelastic element. In this way the inhalers can be “tuned” to disperse the powder most efficiently by adjusting the resonance frequencies of the elastic element to match the physicochemical properties of the powder. In addition, the airflow rate required to generate the appropriate oscillations within the device is minimized because some of the energy used to create the vibrations in the elastic element is pre-stored in the element in the form of elastic tension (potential energy). Inhaler performance may be tailored to the lung function of individual patients by modulating the elastic tension. Thus, even patients with poor lung function and those who have minimal capacity to generate airflow during inspiration will able to attain the flow rate required to induce oscillations in the elastic element.
SUMMARY OF THE INVENTION
[0020] An exemplary embodiment of the invention comprises a dry powder inhaler with an integrated assisted dispersion system that is adjustable according to the patients' inspiratory capabilities and the adhesive/cohesive nature of the powder. The inhaler comprises an aeroelastic element that flutters or oscillates in response to airflow through the inhaler. The aeroelastic element provides concentrated energy of the airflow driven by the patient into the powder to be dispersed. The aeroelastic element is preferably a thin elastic membrane held under tension that reaches optimal vibrational response at low flow rates drawn through the inhaler by the patient. The aeroelastic element is preferably adjustable according to the patient's inspiratory capabilities and the adhesive/cohesive forces within the powder for dispersal.
[0021] According to various aspects of the disclosure, a dry powder inhaler for delivering medicament to a patient includes a housing defining a chamber for receiving a dose of powdered medicament, an inhalation port in fluid communication with the chamber, at least one airflow inlet providing fluid communication between the chamber and an exterior of the housing, and an aeroelastic element in the chamber and associated with a dose of powdered medicament. A tensioning assembly is configured to apply a first amount of tension to the aeroelastic element such that the aeroelastic element is capable of vibrating in response to airflow through the chamber so as to aerosolize the dose of powdered medicament.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 illustrates airflow across an aeroelastic element in accordance with various aspects of the disclosure.
[0023] FIG. 2 illustrates airflow past an airflow modifier and across an aeroelastic element in accordance with various aspects of the disclosure.
[0024] FIG. 3A is a schematic representation of a top cross-sectional view of an exemplary inhaler in accordance with various aspects of the disclosure.
[0025] FIG. 3B is a schematic representation of an end cross-sectional view of an exemplary inhaler in accordance with various aspects of the disclosure.
[0026] FIG. 4 is a schematic representation of first and second rollers loaded with the aeroelastic membrane with axles in the center of the rollers in accordance with various aspects of the disclosure.
[0027] FIG. 5 is representation of an exemplary dosing applicator in accordance with various aspects of the disclosure.
[0028] FIG. 6 is a representation of another exemplary dosing applicator in accordance with various aspects of the disclosure.
[0029] FIGS. 7A-7C are representations of an exemplary aeroelastic membrane and its relation to exemplary base clamps, upper clamps, and tensioning rods in accordance with various aspects of the disclosure.
[0030] FIG. 8 is a representation of an exemplary dispensing mechanism in accordance with various aspects of the disclosure.
[0031] FIG. 9 is a representation of an alternative exemplary dispensing mechanism in accordance with various aspects of the disclosure.
[0032] FIG. 10 is a representation of an alternative exemplary dispensing mechanism in accordance with various aspects of the disclosure.
DETAILED DESCRIPTION
[0033] An exemplary embodiment of a dry powder inhaler 100 is illustrated in FIGS. 3A and 3B . According to various aspects of the disclosure, the dry powder inhaler 100 may comprise a casing 102 having an outer wall 104 and two inner walls 106 , 108 . The inner walls 106 , 108 may extend in a first direction from a first inner surface 112 of the outer wall 104 toward a second inner surface 114 of the outer wall 104 . The inner walls 106 , 108 may also extend in a second direction from a proximal end 116 of the casing 102 to a distal end 118 of the casing 102 . Thus, according to various aspects, the outer wall 104 and inner walls 106 , 108 may cooperate to define three chambers in the casing 102 .
[0034] According to some aspects, the three chambers may include a middle chamber 122 and two side chambers 124 , 126 located on opposite sides of the middle chamber 122 relative to one another. The side chambers may comprise a first side chamber 124 located to a first side of the middle chamber 122 and a second side chamber 126 located to a second side of the middle chamber 122 .
[0035] In accordance with various aspects, the distal end 118 of the casing 102 may include one or more airflow inlets 128 providing fluid communication between the middle chamber 122 and ambient air outside the casing 102 . The proximal end 116 of the casing 102 may include a mouthpiece 130 . The mouthpiece 130 may a separate structure affixed to the outer wall 104 of the casing 102 , or the mouthpiece 130 and casing 102 may comprise a single piece of unitary construction. The mouthpiece 130 may include an opening 132 providing fluid communication between the middle chamber 122 and the outside of the casing 102 . The opening 132 may be shaped as an oval, a circle, a triangle, or any other desired shape. The mouthpiece 130 may have a shape that facilitates pursing of a patient's lips over the mouthpiece 130 and creating a seal between the lips and the mouthpiece 130 .
[0036] The inhaler 100 may include a nozzle 134 between the middle chamber 122 and the opening 132 . According to various aspects, the nozzle 134 may extend from the opening 132 , through the mouthpiece 130 , and into the middle chamber 122 . In some aspects, the nozzle 134 may comprise at least one helical tube 136 through which air and powder can be inhaled. The tube 136 can be configured to increase the turbulence in the air that flows through the nozzle 134 .
[0037] An aeroelastic element 140 may extend across a center region 142 of the middle chamber 122 between the inner walls 106 , 108 . The aeroelastic element 140 may include one or more doses of a medicament 141 , for example, doses of powdered medicament, and the center region 142 may comprise a region for dispensing a dose of medicament into airflow through the inhaler 100 . According to some aspects, the aeroelastic element 140 may comprise a membrane 144 , for example, a thin elastic membrane, wound between two spools 146 , 148 . An unused end of the membrane 144 may be wound on a first spool 146 , and a used end of the membrane 144 may be wound on a second spool 148 . The first spool 146 may be disposed about a first axle 147 , and the second spool 148 may be disposed about a second axle 149 . The first spool 146 may be in the first side chamber 124 , and the second spool 148 may be in the second side chamber 126 . In such an embodiment, the membrane 144 extends through a slot 150 in the inner wall 106 , across the center region 142 , and through a slot 152 in the inner wall 108 . In accordance with some aspects, the aeroelastic element 140 may comprise a membrane, a film, a reed, a sheet, a panel, or a blade. The aeroelastic element may be manufactured of materials comprising polymers, thin metals, polymer-coated metals, and/or metal-coated polymers.
[0038] According to various aspects, the inhaler 100 may include two base clamps 154 , 156 fixedly attached to a first inner surface 112 of the casing 102 . According to some aspects, the base clamps 154 , 156 may be in the middle chamber 122 . A first of the base clamps 154 may be between the center region 142 and the first inner wall 106 , and the second of the base clamps 156 may be between the center region 142 and the second inner wall 108 . The aeroelastic element 140 may rest on the base clamps 154 , 156 . The inhaler 100 may include two upper clamps 158 , 160 in the middle chamber 122 associated with the two base clamps 154 , 156 . For example, a first upper clamp 158 may be on an opposite side of the aeroelastic element 140 relative to the first base clamp 154 and configured to descend atop the first base clamp 154 to sandwich the aeroelastic element therebetween. Similarly, the second upper clamp 160 may be on an opposite side of the aeroelastic element 140 relative to the second base clamp 156 and configured to descend atop the second base clamp 156 to sandwich the aeroelastic element therebetween. The upper clamps 158 , 160 and base clamps 154 , 156 may hold the aeroelastic element 140 in place across the center region 142 with a desired amount of tension. The desired amount of tension may be determined based on a user's inhalation strength. It should be appreciated that in some aspects, the upper clamps may be fixedly attached to the second inner surface 114 of the casing 102 , and the base clamps may be configured to ascend toward the upper clamps to sandwich the aeroelastic element therebetween.
[0039] In an alternative embodiment (not shown), a first of the base clamps 154 may be in the first side chamber 124 between the first spool 146 and the first wall 106 , and the second of the base clamps 156 may be in the second side chamber 126 between the second spool 148 and the second wall 108 .
[0040] The inhaler 100 may include an advancement member 162 extending outward of the casing 102 . The advancement member 162 may comprise, for example, a lever, a dial, or the like. The advancement member 162 may be mechanically coupled to the first and second upper clamps 158 , 160 via, for example, a crank 164 or other known linkage. The advancement member 162 and crank 164 are structured and arranged such that when the advancement member 162 is actuated by a user, the crank 164 is caused to move the upper clamps 158 , 160 in a direction away from the base clamps 154 , 156 . Actuation of the advancement member 162 may also cause the second axle 149 to turn in a manner that increases the used end of the aeroelastic element 140 wound thereon.
[0041] According to some exemplary aspects, as shown in FIGS. 7A-7C , the inhaler 100 may include one or more tensioning rods 166 , 168 configured to increase the tension of the aeroelastic element 140 beyond the tension applied by the base clamps 154 , 156 and upper clamps 158 , 160 . The tensioning rods 166 , 168 are between the first and second upper clamps 158 , 160 . The tensioning rods 166 , 168 may be mechanically coupled to the crank 164 such that actuation of the advancement member 162 causes the tensioning rods 166 , 168 to move in a direction away from the aeroelastic element 140 . When the advancement member 162 is released or unactuated, the tensioning rods 166 , 168 return to a position that applies a desired amount of tension to the aeroelastic element 140 . It should be appreciated that in some aspects, one or more tension controllers 157 , 159 ( FIG. 4 ) may be attached to one or both of the spool axles 147 , 149 , thus allowing the tension of the aeroelastic element 140 to be manually fixed and maintained across the spool axles 147 , 149 and obviating the need for tensioning rods. In any design, the amount tension applied by the clamps, tensioning rods, and/or tension controllers can be determined based on inhalation strength of a user.
[0042] Referring again to FIG. 3B , in various aspects, the second axle 149 associated with the second spool 148 may comprise a concentric spring 170 , which is mechanically coupled to the advancement member 162 so that actuation of the advancement member 162 results in the aeroelastic element 140 being transferred from the first spool 138 to the second spool 148 as the spring-loaded axle 149 is activated. The inhaler 100 may include a roller 172 ( FIG. 5 ) adjacent to the first spool 146 and engaging the aeroelastic element 140 , thereby resulting in additional tension in the aeroelastic element.
[0043] According to some aspects, for example, inhalers having an aeroelastic element with multiple doses of medicament, a dose counter 174 may be mechanically coupled to the advancement member 162 in such a way that the dose counter 174 changes numbers by one each time the advancement member 162 is actuated. In some aspects, the dose counter 174 may be at an exterior surface of the casing 102 so as to be visible to a user. In some aspects, the dose counter 174 may be inside the casing 102 , but visible to a user via a transparent or translucent window (not shown), as would be understood by persons skilled in the art.
[0044] According to various aspects, as shown in FIG. 5 , the inhaler 100 may include a powder dose applicator 176 located between the first spool 146 and the first base clamp 154 . In some aspects, the powder dose applicator 176 may include a dispensing chute 178 filled with at least one dose of powder 180 . The dispensing chute 178 may include a top end 182 and a bottom end 184 . A wheel 186 may be at the bottom end of the dispensing chute 178 . The wheel 186 may be rotatable about an axle 188 . The axle 188 may be mechanically coupled to the advancement member 162 such that the wheel 186 rotates an amount sufficient to dispense one dose of powdered medicament to the aeroelastic element. For example, the wheel 186 may include one or more notches 190 in its periphery, with the volume of each notch being sized for one dose of powdered medicament.
[0045] According to some aspects, the wheel shown in FIG. 5 may be replaced with a dispensing disk 686 , as shown in FIG. 6 . For example, the dispensing chute 178 above the aeroelastic element 140 is filled with at least one dose of powdered medicament. The dispensing disk 686 may be located between the aeroelastic element 140 and the dispensing chute 178 and may be in contact with the bottom end 184 of the chute 178 . The disk 686 may further include multiple dispensing openings 690 clustered in one section of the disk 686 , for example, a periphery of the disk 686 . The dispensing openings 690 correspond to an accurate amount of powdered medicament to be dispensed as a dose. The dispensing disk 686 rotates about an axle 688 as the advancement member 162 is actuated, thereby resulting in an accurate amount of powdered medicament falling through the dispensing openings 690 and to the aeroelastic element 140 . For example, the disk 686 may make one complete 360° rotation each time the advancement member 162 is actuated.
[0046] In various aspects, the inhaler 100 may include blister strip packaging attached to the two spools in place of the powder dose applicators discussed above. For example, as shown in FIG. 8 , the blister strip packaging 801 may include at least one individual dosing cup 803 . Each cup 803 may be filled with a dose of powdered medicament and covered by a peelable top layer. The dosing cups 803 may be arranged serially along the length of the packaging strip 801 . An aeroelastic element 840 may be stretched across the center region 142 and fixedly coupled to, for example, the inner walls or any other structure capable of maintaining the element 840 fixedly stretched across the center region 142 . The strip 801 may be in proximity to the aeroelastic element 840 in the center region 142 such that the aeroelastic element 840 may act as an actuator, making contact with the blister packaging and dispersing the powder dose when the aeroelastic element begins to vibrate during inhalation by a patient. A powder dose opener 805 may be configured to remove the top peelable layer from the blister strip packaging 801 for one dose when the blister strip 801 is advanced from the first spool to the second spool. The powder dose opener may alternatively be a simple puncturing device, such as a needle, that inserts small holes in the blister strip blister cavity, making the dose ready for inhalation.
[0047] In some embodiments, as shown in FIG. 9 , blister strip packaging 901 may include clusters 905 of multiple small dosing cups 903 for simultaneous multiple drug dosing, the clusters 905 may be arranged serially along the length of the blister strip 901 . The large arrows depict the direction of airflow across the blister strip and aeroelastic element. The small vertical arrows depict the vibrational motion of the aeroelastic element. In various embodiments, as shown in FIG. 10 , the inhaler may include an aeroelastic element 1040 that may comprise, for example, an aeroelastic and deformable membrane. The element 1040 may include at least one individual dosing cup 1003 filled with a dose of powdered medicament in the form of blister strip packaging 1001 . The dosing cup 1003 may be configured to deform and raise the powder dose to the level of the surrounding element 1040 .
[0048] It should be appreciated that the inhaler may comprise a single powder dose such that the inhaler may be disposed of after a single use.
[0049] Referring again to FIG. 5 , in some aspects, the inhaler 100 may include two rollers 192 , one above and one below the aeroelastic element 140 . The rollers 192 may be between the powder dose applicator 176 and the first base clamp 154 or between the powder dose applicator 176 and the inner wall 106 . The rollers 192 turn as the aeroelastic element 140 moves from the first spool 146 to the second spool 148 due to the frictional force applied by the aeroelastic element 140 as it is urged past the pinching rollers 192 . The rollers 192 fully engage the aeroelastic element 140 and flatten the powder deposited onto the aeroelastic element 140 and break up clumps in the powder.
[0050] Thus, the advancement member 162 may be capable of turning the crank to release the upper clamps and tensioner rods, advancing the dose counter, turning the wheel in the dispensing chute, advancing the spring-loaded axle in the second spool by one position to advance the aeroelastic element a predetermined distance from the first spool to the second spool, and/or moving a dose of powder medicament into the center region 142 .
[0051] Referring again to FIGS. 3A and 3B , according to various aspects, the inhaler 100 may include one or more airflow modifiers 198 proximal of the one or more airflow inlets 128 and at a distal end of the center region 142 . It should be appreciated that the one or more airflow modifiers 198 may be distal of the center region 142 and/or at a distal portion within the center region 142 . In some aspects, the one or more airflow modifiers 198 may comprise multiple triangular rods extending from the first inner wall 106 to the second inner wall 108 . As air flows through the one or more airflow inlets 128 and toward the center region 142 , the one or more airflow modifiers 198 may cause vortices that allow air to pass above and below the modifiers.
[0052] Referring now to FIG. 1 , airflow at velocity V over an aeroelastic element under tension is illustrated. As shown, the airflow may result in flutter or vibration of the aeroelastic element 140 . The vibration is represented by vertical arrows, and the airflow is represented by horizontal arrows. FIG. 2 illustrates the airflow at velocity V past an airflow modifier prior to encountering an aeroelastic element 140 . As shown, the airflow modifier introduces turbulence into the airflow, thus increasing the vibration or flutter of the aeroelastic element for a given inhalation strength.
[0053] In operation, a method for dispensing powder by inhalation using any of the aforementioned exemplary dry powder inhaler apparatuses may begin with a patient actuating the advancement member. The patient may purse his/her lips around the mouthpiece and inhales. As the patient inhales, air is sucked into the inhaler through one or more airflow inlets at the distal end of the inhaler. The inhaled air flows over the airflow modifiers. The airflow then encounters the aeroelastic element, causing the element to vibrate or flutter and disperse a dose of powdered medicament from the element into the airflow. The combined flow of air and powder then flow into the distal end of the airflow nozzle and the mouthpiece. The combined flow of air and powder leave the mouthpiece and enter the patient's mouth and respiratory tract. The airflow modifiers and/or the helical shape of the nozzle may increase the turbulence of the airflow to better aerosolize and break up the powdered dose of medicament into smaller particles, thus maximizing the dose received by the patient and allowing the smaller particles to pass further into the respiratory tract.
[0054] It will be apparent to those skilled in the art that various modifications and variations can be made in the inhalers and methods of the present disclosure without departing from the scope of the invention. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only.
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A dry powder inhaler for delivering medicament to a patient includes a housing defining a chamber for receiving a dose of powdered medicament, an inhalation port in fluid communication with the chamber, at least one airflow inlet providing fluid communication between the chamber and an exterior of the housing, and an aeroelastic element in the chamber and associated with a dose of powdered medicament. A tensioning assembly is configured to apply a first amount of tension to the aeroelastic element such that the aeroelastic element is capable of vibrating in response to airflow through the chamber so as to aerosolize the dose of powdered medicament.
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RELATED APPLICATIONS
This is a continuation-in-part application, claiming the priority benefit of application Ser. No. 14/795,972, filed Jul. 10, 2015, which claims the priority benefit of Provisional Application Ser. No. 62/023,634, filed on Jul. 11, 2014, both of which applications are hereby incorporated by reference.
FIELD OF THE INVENTION
The present invention relates to antennas and access points (radio transmitting devices) and the methods in which to locate them together such that they operate as a single apparatus instead of two distinct parts or components.
BACKGROUND OF THE INVENTION
Wireless communications are prevalent everywhere in today's society. Access points (radios) are used to provide wireless communication and antennas are used on the access points to transmit and receive data. The antennas used on access points are either internal or external antennas. Internal antennas are designed inside the access point and are inconspicuous to the users. External antennas are connected to the access port via coaxial cables and are seen by the users. When these access points are mounted to the ceiling or the wall, the antenna is mounted in as close proximity as possible to the access point. The cables and antenna can be bulky and not aesthetically pleasing to the owner of the structure (building) or users of the system.
The co-locating of antennas and access points has been accomplished in the past by mounting an enclosure on the wall or a pole/mast. The enclosure has the access point (radio) mounted to a back plate inside the enclosure and the antenna mounted onto the door of the enclosure. This type of design does not provide the articulation for the antenna and can be big, bulky and heavy.
Ceiling tile enclosures have been used to mount access points and external antennas but the antennas do not have a way for them to be articulated.
There have been other instances where the access point is mounted inside an enclosure that is mounted on the ceiling, replacing a ceiling tide grid. On the outside or in some case inside, the external antennas are mounted and connected to the access point.
SUMMARY OF THE INVENTION
The present invention provides a mount for an access point (radio) and an antenna, including a base for attachment to a support structure, the base for attaching thereto an access point; and a tray pivotably attached to the base, the tray for attaching thereto an antenna. The tray is disposed above the base and the tray is positionable at an angle relative to a reference plane.
The mount according to the present invention advantageously co-locates the antenna on top of the access point (radio) in a clamshell type of design. The antenna is attached in such a manner that it can swivel about ±25° such that it can be positioned to optimize its performance in conjunction with the radio. The mount is designed such that the cables from the antenna to the radio are hidden between the antenna and access point. There are clips that the cables are routed through that hold the cables in place. When the antenna and access point are attached to the mount, it looks as if there is only an antenna mounted for an aesthetic installation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a mount showing a base for an access point and a tray for an antenna.
FIG. 2 as side elevational view of the mount of FIG. 1 , showing an access point attached to the base and an antenna attached to the tray.
FIG. 3 is a perspective of the base of the mount.
FIG. 4 is a perspective view of the bottom side of the tray.
FIG. 5 is bottom plan view of the tray shown in FIG. 4 .
FIG. 6 is an assembly view of the mount of FIG. 1 .
FIG. 7 is a side elevational view of the mount of FIG. 2 , showing the range of adjustment of the tray.
FIG. 8 is a blank of the base of mount.
FIG. 9 is a blank of the tray.
FIG. 10 is a cross-sectional view along lines 10 - 10 in FIG. 6 .
FIG. 11 is a perspective view of another embodiment of a mount for an access point and an antenna.
FIG. 12 is a side elevational view of the mount of FIG. 11 .
FIG. 13 is a top perspective view of a swivel base used with the mount of FIG. 11 .
FIG. 14 is a bottom perspective view of FIG. 13 .
FIG. 15 is a front elevational view of FIG. 13 .
FIG. 16 is a partial perspective view, showing an adjustment feature of the mount of FIG. 11 .
DETAILED DESCRIPTION OF THE INVENTION
A mount 2 embodying the present invention for co-locating an antenna 4 and an access point (AP) 6 is disclosed in FIGS. 1 and 2 . The mount 2 includes a base 8 and a tray 10 pivotably attached to the base 8 .
Referring to FIG. 3 , the base 8 is preferably formed from sheet metal into a substantially U-shaped structure with a base portion 12 and leg portions 14 and 16 extending from the base portion 12 . Keyhole shaped openings 18 are provided on the base portion 12 for use in attaching the access point 6 to the base portion 12 . Holes 20 are used to attach the base 8 to a vertical or horizontal support structure, such as wall or ceiling of a building. Holes 22 and 23 are used to attach the base 8 to a ceiling tile grid using a standard clamp. A captured nut 25 is used to ground the access point 6 .
A locking tab 31 is used to padlock the access point 6 if desired. The locking tab 31 is preferably made from sheet metal.
The base portion 12 includes a main base portion 24 , attachment walls 21 and arms 26 and 28 extending from the intermediate portions 27 and 29 of the respective sides of the raised attachment walls 21 . The attachment walls 21 are offset from the main base portion 24 . Each of the arms 26 and 28 are bent preferably about 90° at intermediate portions 30 and 32 to form the legs 14 and 16 of the U-shaped base 8 . The main base portion 24 is preferably substantially rectangular in plan view and the arms 26 and 28 are preferably longer than they are wide. Adjusting screws 34 are attached to the end portions of the respective leg portions 14 and 16 for attaching the tray 10 to the base 8 .
The main base portion 24 is advantageously offset from the raised attachment walls 21 to provide clearance for the screws or other standard attachment hardware that is used to attach the base 8 to a support structure, such as the building wall or ceiling. The raised attachment walls 21 further provide for attaching the access point 6 to the base 8 after the base has been secured to the support structure.
Referring back to FIG. 1 , the tray 10 includes a base wall 36 and side walls 38 and 40 . The side walls 38 and 40 are preferably 90° to the base wall 36 . The side walls 38 and 40 are advantageously pivotably attached to and angularly adjustable from the base 8 by means of the screws 34 . Cut-out corners 42 and 44 are provided at opposite corners of each of the side walls 38 and 40 to provide clearance when the position of the tray 10 is adjusted angularly about the screws 34 (see FIG. 7 ).
Referring to FIGS. 4 and 5 , the tray 10 is shown with the underside 45 visible. Holes 46 are disposed in the base wall 36 for screws to go through for attaching the antenna 4 to the tray 10 . Cable holders 48 of standard construction are attached to the underside 45 along the corner between the base wall 36 and the side walls 38 and 40 . The cable of the antenna 4 is routed underneath the tray 10 and held by the cable holders 48 . Captured nuts 50 are attached in corresponding openings in the side walls 38 and 40 for threadedly receiving the adjusting screws 34 . Holes 52 disposed in the side walls 38 and 40 are used for attaching the cable holders 48 to the tray 10 .
Side walls 53 and 55 disposed preferably 90° to the base wall 36 advantageously provide structural rigidity to the base wall 36 . A notch 57 advantageously provides space for cable routing between the antenna 4 and the access point 6 .
Referring to FIG. 6 , the mount 2 is shown in an assembly view. Adhesive backed foam washers 59 are disposed between the leg portion 16 and the side wall 38 and between the leg portion 14 and the side wall 40 . The foam washers 52 include an adhesive on one surface for attachment to either the leg portions 14 and 16 or the side walls 38 and 40 . The foam washers 52 advantageously provide friction between the confronting surfaces of the leg portion 16 and the side wall 38 and the leg portion 14 and the side wall 40 so that that tray 10 when pressed together with the adjusting screws 34 will be locked in the desired angular position and will tend to shift. A person of ordinary skill in the art will understand that metal to metal contact has less friction than metal to foam.
Raised dimples 76 are provided to securely hold the access point 6 in place. Each keyhole-shape opening 18 is associated with a raised dimple 76 , which is disposed outwardly of the respective raised dimple 76 .
Referring to FIG. 7 , the base wall 36 of the tray 10 is angularly adjustable either clockwise or counterclockwise by about 25° relative to a reference plane 61 , which is preferably parallel with the main base portion 24 , from a base position 63 wherein the base wall 36 is preferably parallel with the reference plane 61 . Taking counterclockwise direction as positive and clockwise direction negative, the tray is adjustable about ±25°. The ability to provide antenna articulation of about ±25° provided by the mount 2 advantageously allows for optimization of system performance via positioning of the antenna 4 .
Referring to FIG. 8 , the base 8 is preferably made from a sheet metal blank 54 with a central portion 54 and arms 58 and 60 . To make the base 8 , the central portion 56 is bent up preferably 90° along lines 62 to form the main base portion 24 and bent down preferably 90° along lines 64 to form the attachment walls 21 . The arms 58 and 60 are then bent up preferably 90° along lines 66 to form the leg portions 14 and 16 . A tab 67 is used to attach the locking tab 31 to the base 10 by regular means, such as by spot welding. Holes 69 are provided for the screws 34 .
Referring to FIG. 9 , the tray 10 is preferably made from a sheet metal blank 68 . To make the tray 10 , the blank 66 is bent down preferably 90° along lines 70 , 72 and 74 to form the side walls 38 , 40 , 53 and 55 . Holes 75 are provided for the captured nuts 50 .
Referring to FIG. 10 , a partial cross-sectional view of the base 8 shows the manner of attaching the access point 6 to the base 8 . Raised dimples 76 support the bottom surface of the access point 6 . Attaching screws 78 includes flanges 80 substantially aligned with the top surface 82 of the attachment walls 23 . When the attachment walls 23 are pressed down in the direction 91 and flex about the offset walls 90 , the access point 6 moves down, allowing the screw flanges 80 to be positioned below the bottom surface 84 of the attachment walls 23 . This allows the access point 6 to be translated on the attachment walls 23 so that the flanges 80 are then positioned below the narrow slot of the keyhole shaped openings 18 . When the attachment walls 23 are released from the downward pressure generally indicated by the arrows 91 , the attachment walls 23 flex back to their original position, thereby capturing the screw flanges 80 under the bottom surface 82 . Thus, the access point 6 is securely attached to the attachment walls 23 . The space 86 below the raised attachment walls 21 allows for the downward flexing of the attachment walls 21 . The space 86 further provides clearance for the screw heads of the screws 80 from the surface of the support structure, such the building wall or ceiling. The offset 88 advantageously provides clearance for the screw heads or other standard hardware used to attach the base 8 to the support structure.
Once the base 8 is attached to the support structure and the access point 6 secured to the base 8 , all attaching screws or attachment hardware are advantageously hidden from view and inaccessible, thereby deterring theft.
Referring to FIGS. 11 and 12 , another embodiment of a mount 92 is disclosed. The mount 92 comprises the mount 2 with a swivel base 94 attached to the stationary base 96 , which is similar to the base 8 of the mount 2 . The swivel base 94 includes a plate 98 rotatably mounted to a fixed mounting base 100 , which is for securely attaching the mount 92 to a fixed structure, such a wall or ceiling of a building. The plate 98 is rotatably adjustable relative to the fixed mounting base 100 . The plate 98 is preferably flat defining a plane.
The plate 98 has circular arc slots 102 disposed opposite to each other. A screw 104 captured between the between the plate 98 and the fixed base 100 through is mounted in each slot 102 guides the plate 98 as it rotates clockwise or counterclockwise. The screw 104 is tightened at each slot 102 after the proper rotational adjustment is made.
The swivel base 94 is shown in detail in FIGS. 13-15 . The base 100 is preferably further attached to the plate 98 with a pivot 104 disposed at the center of the circular arc slots 102 to advantageously aid in the rotation of the plate 98 during adjustment. The pivot 104 defines an axis of rotation 105 , which is preferably perpendicular to the reference plane 61 , which is preferably parallel to the plane of the plate 98 . The swivel base 94 , which can rotate about ±25°, advantageously provides further optimization of system performance via positioning of the antenna 4 .
Referring back to FIGS. 11 and 12 , the leg portions 14 and 16 each includes a circular arc slot 106 with the screw 34 as the center. A locking screw 108 is provided in each slot 106 for locking the tray 10 at the desired angular adjustment (see FIG. 7 ) relative to the reference plane 61 , which is preferably parallel to the plate 98 . The tray is adjustably rotatable about an axis 110 extending through the adjusting screws 34 (see FIG. 3 ). The axis 110 is preferably parallel to the reference plane 61 , which is preferably parallel to the plane of the plate 98 .
Referring to FIG. 16 , each of the leg portions 14 and 16 (leg portion 16 is not visible) is provided with a projection 112 that is received in any one of a series of depressions 114 on the respective side wall 38 and 40 (side wall 38 not shown). The depressions 114 are arranged along a circular arc with the screw 34 as the center. The depressions are preferably spaced apart at 5° intervals to provide more defined articulation of the tray 10 . The projection 112 and the depressions 114 advantageously provide predefined angular positions for convenient adjustment.
The mount 2 or 92 advantageously co-locates the antenna 4 on top of the access point (radio) 6 in a manner that generally hides the access point 6 from view to make it look like there is only the antenna 4 that is mounted. This is accomplished by having the tray 10 overly the base 8 at all sides of the base 8 (see FIGS. 2 and 7 ). The tray 10 also has downwardly disposed side walls 38 , 40 , 53 and 55 , which hide portions of the access point 6 from view. The base 8 or 96 together with the tray 10 is similar to a clamshell. The mount 2 is designed such that the cables from the antenna 4 to the access point 6 are hidden.
The ability to co-locate the access point 6 and the antenna 4 and have this configuration operate as a single apparatus gives a distinct advantage over the current methods of hanging, placing or securing an access point on a wall or ceiling. The mount 2 advantageously saves space and is aesthetically pleasing.
While this invention has been described as having preferred design, it is understood that it is capable of further modification, uses and/or adaptations following in general the principle of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains, and as may be applied to the essential features set forth, and fall within the scope of the invention or the limits of the appended claims.
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Mount for an access point and an antenna includes a base for attachment to a support structure, the base for attaching thereto an access point; and a tray pivotably attached to the base, the tray for attaching thereto an antenna. The tray is disposed above the base and the tray is positionable at an angle relative to a reference plane.
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BACKGROUND
The invention pertains to sensors, and particularly to flame sensors. More particularly, the invention pertains to circuitry for flame sensors.
The present application is related to the following indicated patent applications: “Dynamic DC Biasing and Leakage Compensation”, U.S. application Ser. No. 10/908,463, filed May 12, 2005; “Leakage Detection and Compensation System”, U.S. application Ser. No. 10/908,465, filed May 12, 2005; “Adaptive Spark Ignition and Flame Sensing Signal Generation System”, U.S. application Ser. No. 10/908,467, filed May 12, 2005; which are all incorporated herein by reference.
SUMMARY
The invention may include a flame sensor for a control system having at least one floating reference point and diagnostics relating to the system.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a circuit of a flame sensing system;
FIG. 2 is another circuit of the flame sensing system;
FIG. 3 is a graph of flame sensing signal relative to a ground and flame on and off signals;
FIG. 4 is a diagnostic circuit for the flame sensing system; and
FIG. 5 is a graph of two out-of-phase signals from half-wave rectified power input signals.
DESCRIPTION
Hydrocarbon flames may have certain electrical properties. A commonly used electrical flame model may be a diode in series with a resistor and a leakage resistor in parallel with the diode and resistor combination. Many flame detectors rely on the flame diode behavior. These detectors may have a relatively high voltage AC signal coupled to the flame (detector) through a capacitor. When a flame exists, because of the flame diode effect, a DC offset voltage may appear. Flame detection may be realized by detecting the existence and amplitude of the DC offset component. When the flame is weak, the series resistance (according to the flame model) may be quite large, resulting in the generating of a very small DC component and then making flame detection more difficult. To compensate for the reduced DC component, the device for detecting a weak flame may have to be very sensitive, or the AC excitation voltage may need to be increased up to several hundred volts. If a standard line voltage is used, then filtration of the low-frequency AC component may require high ohm filter resistors that slow a circuit's detection of a flame and add vulnerability to leakage. If a high-frequency voltage AC signal is generated locally to avoid the problems of high ohm resistors, then the cost of the flame sensing system may increase significantly. The present invention may provide a solution to the noted problems by utilizing the leakage resistor of the flame model rather than the diode. Leakage may be used for diagnostic purposes. The phases between certain components and one of the grounds may have a synch or out-of-synch relationship. This relationship may also be used for diagnostic purposes. There may be other leakage detected.
FIG. 1 reveals a flame sensing system that does not have a flame excitation signal at the flame sensing rod. Instead, the sensing system uses the voltage difference between an earth ground 11 and a control ground 12 to detect the current path provided by the flame. The flame sensing system, without circuit to generate the excitation signal, may be of very low system cost. The system may have a system reference point 12 (i.e., the control ground) floating relative to the earth ground 11 . An AC power supply 13 may be common line power or 24 volts AC from a transformer or other power source. One end of the AC power supply 13 may be connected to the earth ground 11 which may also be regarded as an appliance ground. The ground 11 connected to one end of the AC supply 13 may be designated as a C phase. The other end 14 of the supply 13 may be designated as an R phase. The anode of diode 15 and the cathode of diode 16 may be connected to a lead 14 of the AC supply 13 . The anode of diode 17 and the cathode of diode 18 may be connected to lead 65 of the supply 13 . The cathodes of diodes 15 and 17 may be connected to each other. The lead 65 and ground 11 may be commonly connected. The anodes of diodes 16 and 18 may be connected together and to a circuit or control ground 12 . Diodes 15 , 16 , 17 and 18 may form a full-wave rectifier 19 . A load resistor 21 may have one end connected to the cathodes of diodes 15 and 17 and the other end connected to the anodes of diodes 16 and 18 . The ends of resistor 21 may look at a full-wave DC output of rectifier 19 which is a rectification of the AC output of supply 13 . Resistor 21 may represent a control system load, such as for example, supporting electronics and/or a microcontroller 40 .
A first flame resistor 22 may have an end connected to the appliance or earth ground 11 . A second flame resistor 23 may have an end connected to the ground 11 . A flame diode 24 may have a cathode connected to the other end of resistor 22 and an anode connected to the other end of resistor 23 . The flame diode 24 , the first flame resistor 22 and the second flame resistor 23 may make up a model circuit or network 25 that indicates a presentation of a flame.
A resistor 26 may have one end connected to a flame rod 62 . The other end of resistor 26 may be connected to a terminal 29 . One end of a resistor 27 may be connected to the terminal 29 and the other end of the resistor 27 may be connected to the circuit ground 12 . Also shown is a dashed-line resistor symbol 53 representing a leakage current path from rod 62 to ground 11 . Resistor 26 and resistor 27 may form a flame detection interface circuit 31 . Resistors 26 and 27 may form a voltage divider. Resistor 26 may provide current limiting of flame detection signals to an analog-to-digital (A/D) converter input which is connected to the terminal 29 . The resistor 27 may help to convert the flame current into a flame voltage. Also, resistor 27 may pull down the A/D input at terminal 29 when there is no signal present to the A/D input. Optionally, a capacitor (not shown) may be connected in parallel with resistor 27 to filter out any induced noise at terminal 29 . A flame signal from circuit 25 may go via resistor 26 and node or terminal 29 to the A/D converter of a microcontroller 40 .
FIG. 2 shows a circuit configuration 20 which may be partially different than that of circuit 10 in FIG. 1 . Source 13 is like that of circuit 10 in that it may be a line voltage of about 115 or 220 volts at 50 or 60 Hz or so. It may instead be 24 volts or some other low voltage. The source 13 may be a secondary winding of a transformer. The source 13 may have one side connected to the appliance ground 11 . If an AC voltage that is used is about 100 volts or higher, then a low cost flame sensing approach may be implemented (e.g., a voltage increaser might not be needed). One end of a capacitor 61 may be connected to the R-phase line 14 . Capacitor 61 may be a DC blocking capacitor. The other end of capacitor may be connected to resistor 26 of network 31 and to a sensing flame rod 62 which is connected to a representative or model circuit 25 which appears electrically when a flame is sensed. When a flame is not present, the electrical equivalent circuit 25 may appear as open or non-existent concerning diode 24 and resistors 22 and 23 . However, current leakage may remain in absence of a sensed flame, as its path may be represented by a resistor symbol 53 . The cathode of diode 24 and one end of the resistor 23 , when model circuit 25 appears during the sensing of a flame, may be connected to the earth or appliance ground 11 . Leakage path 53 likewise may connect flame rod 62 to ground 11 .
Resistor 26 may be part of a voltage divider that includes a resistor 27 . An optional capacitor 28 (shown) may be connected in parallel with resistor 27 . The other end of resistor 27 may be connected to the circuit or control ground 12 . An output 29 of the network 31 may go to an A/D converter of a microcontroller or processor 40 . The controller or processor may be electrically referenced on or tied to a circuit or control ground 12 . The circuit or control ground 12 may float relative to the appliance or earth ground 11 .
Resistor 27 and capacitor 28 may be selected such that a time constant of resistor 27 and an optional capacitor 28 equals to about 0.3 to 1.0 portion of a half-cycle of time of the AC power supply 13 output. With this time constant value, the peaks of the flame signal may appear at about the zero-crossing time of the C phase pulses (i.e., <90 degrees out of phase), and the peak-to-peak value of the flame signal may be attenuated very little. One set of exemplary values may include resistor 26 as one megohm, resistor 27 as one megohm, and the optional capacitor as 4700 picofarads.
The leakage of the flame rod 62 may occur due to, for example, old or weak insulation. There may be cross-leakage or other kinds of leakage. The leakage may be measured for calibration purposes. A leakage component may be used to detect a flame rod short, open, or leakage to something such as one of the grounds or components. Leakage may range from the nanoampere to the microampere range. For instance, there may be a one microampere of leakage current and the flame sensor may be usable for flame detection purposes despite a 200 nanoampere signal indicating a flame. Flame indication currents may range from hundreds of nanoamperes to several tens of microamperes. If the leakage current is beyond a level where the system can not be comfortably relied on, the system may be calibrated relative to the leakage (e.g., with a leakage current magnitude subtracted from a flame indication signal).
FIG. 3 reveals waveforms of the C phase pulses 32 , a flame on time 33 and off time 34 , and a flame signal 35 at the A/D input terminal 29 . The C phase peaks 32 may be about 33 volts for a 24 volt AC powered system and about 162 volts for a 115 volt AC powered system. The floor 36 of the C phase pulses 32 may be about one diode drop below the circuit ground 12 level 54 .
There may be several situations involving flame rod sensor leakage: no flame and no leakage; no flame and some leakage; a flame and no leakage; and a flame and some leakage. These combinations may be apparent on the signal at the terminal 29 to the A/D converter of the controller or processor 40 . When a flame exists, the flame leakage resistor 23 may provide a current path from the C phase to the interface circuit 31 . The resulting current may produce a flame voltage signal at the A/D input 29 . The micro controller 40 may note the peak-to-peak value of the flame voltage signal and determine if a flame exists and if so whether the flame is strong enough. When a flame does not exist, the current path may be open and no flame signal is present at the A/D input 29 . Consequently, the flame diode 24 and the series flame resistor 22 appear to have little or no effect on the flame leakage detection mechanism. Inherently, the flame circuit 25 appears to be sensitive to current leakage from the earth ground 11 to flame rod 62 .
When there is no flame, the circuit 25 is open or at that time non-existent. However, there may be current leakage of the flame rod 62 when there is no flame, which may be represented by a resistance 53 as shown in circuit 20 in FIG. 2 . This resistance 53 and resultant leakage may exist even when there is no flame. In FIGS. 1 and 2 , rod leakage resistor 53 appears in parallel with flame resistor 23 . Therefore, resistor 53 may produce the same signal as shown by waveform 35 in FIG. 3 . Waveform 35 shows the C-phase signal appearing at A/D input if flame resistance 23 or leakage resistance 53 exists. Waveform 35 may be of a circuit without the capacitor 28 in the interface circuit 31 . The noted waveforms in FIG. 3 are example representations of the signals for illustrative purposes. These representations may vary in shape, magnitude and timing due to various circuit elements, component values, and signal and element parameters.
As the rod leakage resistance 53 may produce the same signal as flame resistance 23 can, one may need to take necessary precautions to limit the leakage path and check for leakage during operation. A printed circuit board (PCB) of the system may be laid out such that resistor 26 is well isolated from earth ground 11 connections. The flame rod and flame wire should likewise be well insulated. The leakage may and should be checked during each heating cycle involving a sensed flame. Before a flame is lit, the signal caused by leakage may be measured and the peak-to-peak value checked against a predetermined threshold. If the value is too high, then the flame sensing circuit may be unreliable because of high leakage. There may be a device with a warning indicating such. Otherwise, the peak-to-peak value of the leakage signal may be used as an offset value and be subtracted from the flame signal 35 when the flame is on as indicated by signal 33 .
This approach may also be used to detect the presence of a short circuit between the flame rod 62 and the earth ground 11 , such as an appliance ground, which may be a nuisance problem common during related appliance servicing. When the flame rod 62 is shorted to the appliance or earth ground 11 , a very large C-phase component may be noticed at the A/D input 29 . This peak value may be compared with a measured value for the C-phase and a determination may be made if the flame rod is shorted, or not, to the earth ground 11 . If the flame rod 62 is determined to be shorted, then a control system may annunciate some kind of a problem alert to a service person.
This approach may also be used to detect which phase of a low voltage transformer of a source 13 is connected to earth ground 11 . For example, if a circuit 30 of FIG. 4 is directly connected to one of the transformer 41 connections 45 or 46 , it may compare the phase (R or C) of that connection with the signal measured by the flame sense input. If the flame sense signal is in phase with the reference transformer 41 connection, it may be assumed that the R-phase is connected to the earth ground 11 . Otherwise, if the flame sensor signal may be more out of phase with the referenced transformer connection, it may be assumed that the C-phase of the transformer is grounded. As shown by the reference phase (R phase) waveform 37 and the flame detector phase (C phase) waveform 38 in FIG. 5 , which are not in phase with each other, it may be determined that the reference phase is not connected to the earth ground 11 .
Circuit 30 that may be utilized for determining which phase of a low voltage transformer 41 is earth grounded, as described above. Transformer 41 may have an AC input to leads 42 and 43 of its primary winding. The transformer 41 may provide isolation between the circuit 30 and an AC supply 44 . The secondary winding may output a 24 volt AC signal at leads 45 and 46 . The output of the transformer 41 may go to a full-wave bridge rectifier 19 . Control electronics 40 may be connected across the rectifier 19 . Control electronics 40 may include input analog-to-digital converter (ADC) 63 and ADC 64 .
Lead 45 may be connected to an anode of diode 17 and a cathode of diode 18 . Lead 46 may go to an anode of diode 15 and a cathode of diode 16 . The cathodes of diodes 15 and 17 may be connected together. The anodes of diodes 16 and 18 may be connected to a circuit ground 12 . Lead 46 of the secondary winding may be connected to an earth or appliance ground 11 . A resistor 66 may have one end connected to lead 45 , and have the other end connected to one end of a resistor 67 . The other end of resistor 67 may be connected to circuit ground 12 . The connection between resistors 66 and 67 may be a reference point 47 . Resistors 66 and 67 may constitute a network 51 . Point 47 may reveal a signal of ground 11 relative to ground 12 since the ADCs 63 and 64 may use a circuit ground 12 reference.
A resistor 27 may have one end connected to the circuit ground 12 . The other end of resistor 27 may be connected to one end of a resistor 26 . The other end of resistor 26 may be connected to flame rod 62 which in turn is connected to lead 46 of transformer 41 and ground 11 through flame resistor 23 when a flame exists. The connection between resistors 27 and 26 may be regarded as a flame sense point 48 . Resistors 27 and 26 may constitute a network 52 . A reference point 47 of network 51 may be connected to ADC 63 and flame sense point 48 of network 52 may be connected to ADC 64 of control electronics 40 . The signal to ADC 63 may indicate a phase sensing and the signal to ADC 64 may indicate a flame sensing signal imposed on a phase signal relative to ground 12 . The signals to ADC 63 and ADC 64 may be about 180 degrees out of phase relative to each other under normal circumstances.
In the present specification, some of the matter may be of a hypothetical or prophetic nature although stated in another manner or tense.
Although the invention has been described with respect to at least one illustrative example, many variations and modifications will become apparent to those skilled in the art upon reading the present specification. It is therefore the intention that the appended claims be interpreted as broadly as possible in view of the prior art to include all such variations and modifications.
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A low cost flame sensing system having at last one floating point. For instance, the system may have two grounds. There may be a flame sensing rod for detecting a flame which has a model circuit which appears upon the existence of the flame proximate to the sensing rod. The sensing rod may function without an explicit or dedicated excitation source connected to it. There may be diagnostics in the system for detecting leakage or shorts of the sensing rod to ground. Also, the system may have AC grounding phase detection.
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TECHNICAL FIELD OF THE INVENTION
[0001] The present invention involves the use of adrenal enzyme inhibitors for inhibiting increased secretion of cortisol in response to stressful stimuli such as anxiety, anger, depression and fear thus ameliorating such maladies as glucocorticoid-mediated insulin resistance, hypertension, obesity and atherosclerosis.
BACKGROUND OF THE INVENTION
[0002] Diabetes, hypertension, obesity and cardiovascular disease are the most prevalent medical conditions in western societies and are rapidly becoming the major causes of mortality and morbidity in developing countries as well. It is estimated that hypertension affects approximately 20% of the persons in the United States and world wide. The corresponding numbers for diabetes are 10-5% of the population, 10-12% for obesity and for cardiovascular disease 10-5%. Despite major advances in treating these conditions, current treatment is inadequate.
[0003] Obesity is likewise becoming more and more prevalent in western societies as well as in developed countries and is now described as an epidemic. In particular, central or intra-abdominal fat accumulation is associated with increased risk of cardiovascular disease.
[0004] These three conditions, diabetes, hypertension and obesity, co-segregate and are associated with a variety of other metabolic abnormalities such as low concentrations of HDL cholesterol, elevated concentrations of triglycerides and small dense low density lipoprotein.
[0005] Decreased blood concentrations of dehydroepiandrosterone and elevated blood concentration of cortisol are associated with increased atherosclerosis. For example, patients with Cushing's Disease exhibit coronary artery disease at a rate four times higher than the general population. Many conditions associated with increased cortisol secretion, such as depression, low birth weight, advancing age, hostility, and mental stress predispose to coronary disease. Other conditions known to be related to the risk of cardiovascular disease such as insulin resistance, central obesity display increased cortisol secretion and stress-related cortisol secretion was associated with visceral adiposity, blood pressure and increased concentrations of glucose and insulin. Decrease dehydroepiandrosterone concentrations are correlated with future cardiovascular disease events and extent of angiographically documented coronary disease. Dehydroepiandrosterone feeding prevents atherosclerosis in cholesterol-fed animals. The following is known from the teachings of others.
[0006] Subjects with insulin resistance have a similar metabolic profile to patients with Cushing's Disease, who are known to have increased CVD mortality and increased atherosclerosis even years after successful cure. 24-hour cortisol rhysmicity may be responsible, at least in part, for the diurnal variation in glucose tolerance. Mental stress results in elevation in cortisol, and this increase is attenuated by estrogen, which is known to prevent atherosclerosis and stress-mediated cortisol secretion was positively correlated with visceral obesity, insulin, glucose and blood pressure. Depressed patients have increased CAD incidence and have increased diurnal plasma concentration of cortisone and this correlates with increased fasting insulin and glucose and increased visceral obesity. Men have a higher rate of cortisol production than women and have a higher incidence of cardiovascular disease. Vital exhaustion and hostility increase adrenal responsiveness to adrenocortical stimulating hormones and hostility is associated with increased coronary calcification, a marker for coronary artery disease.
[0007] Glycemic control in diabetic patients deteriorates following even minor everyday stress. Normal morning rise in cortisol inhibits lipolysis and this is reversible by metyrapone. Increased age is associated with increased endogenous glucose production, increased cortisol production, and decreased dehydroepiandrosterone production. Syndromes with insulin resistance, such as polycystic ovary disease, are associated with increased adrenal sensitivity to adrenocortical stimulating hormone during insulin-induced hypoglycemia and increased secretion of cortisol.
[0008] Women with increased abdominal fat show increased and prolonged cortisol secretion following mental stress. People with low birth weight, who are known to be at increased risk of insulin resistance, have elevated plasma cortisol concentrations.
[0009] The incidence of cardiovascular disease events and the presence of narrowing of the coronary arteries by angiography are associated with decreased concentrations of dehydroepiandrosterone in men and dehydroepiandrosterone supplementation inhibits atherosclerosis in animal models. Metabolic parameters associated with insulin resistance, in particular, central obesity, are associated with evidence of increased coronary artery disease.
[0010] 11-beta-hydroxysteroid dehydrogenase type 1 knockout mice (which have decreased peripheral conversion of inactive 11-dehydrocortisone to active corticosterone) are resistant to stress-induced hyperglycemia and obesity.
[0011] Patients with essential hypertension have increased urinary free cortisol (a marker of increased cortisol production). Blockage of glucocorticoid receptors with RU 486 ameliorated diabetes in OB/OB mice who display massive obesity and diabetes. Glucocorticoids inhibit Glut 4 receptor expression and insulin and noninsulin-induced trans-membrane glucose transport.
[0012] Glucocorticoids promote adipose tissue-mediated production of plasminigen activator inhibitor 1 (a protein which promotes the formation of blood clots production by human adipose tissue). Glucocorticoids inhibit the availability of tretrahydropterin and nitric oxide and inhibit flow-mediated vasodilatation, which are normally protective against atherosclerosis. In cell culture, pulse treatment with dexamethasone promotes smooth muscle proliferation, promotes cholesteryl ester formation and impairs cholesterol egress from lipoprotein depos by HDL.
SUMMARY OF THE INVENTION
[0013] The invention relates to the use of inhibitors of adrenal synthesis for specific medical conditions. By inhibiting the secretion of glucocorticoids and promoting the secretion of dehydroepiandrosterone by the adrenal gland, this treatment will block or reverse the processes cited above leading to improved glucose tolerance, reduced blood pressure, decreased obesity, in particular, central obesity, and reduced atherosclerosis. Of particular interest, is to specifically inhibit enzyme 3-betahydroxysteroid deydrogenase. As its preferred embodiment, the present invention is directed to the use of an inhibitor comprising a member selected from the group consisting of epostane and trilostane, a specific inhibitor of 3-beta HSD via a wide variety of delivery systems.
DETAILED DESCRIPTION OF THE INVENTION
[0014] This invention relates to the use of epostane, trilostane as well as any other inhibitor of adrenal gland synthetic pathway, delivered transcutaneously, sublingually, orally, rectally or via any other delivery route. Use of these compounds is specifically designed to reduce the abnormal secretion of cortisol in response to stress. As described in the background section, inhibition of the increased secretion of cortisol in response to stressful stimuli such as anxiety, anger, depression, fear and others, will result in amelioration of glucocorticoid- mediated insulin resistance, hypertension, obesity and atherosclerosis.
[0015] Such use for inhibitors of adrenal enzyme has not previously been proposed and is therefore unique and novel.
[0016] It will be appreciated by those skilled in the art that the application of trilostane or other inhibitors of adrenal enzyme synthesis can be used not only for treatment of an existing condition but also extends to prophylaxis. Trilostane, epostane or other enzyme inhibitors can be administered in any conventional way and the invention therefore includes within its scope pharmaceutical compositions including active ingredients and one or more physiologically acceptable diluents or carriers. The compounds according to the present invention may, for example, be formulated for oral, transcutaneous, buccal, sublingual, parenteral, local or rectal administration. Local administration includes administration by insufflation and inhalation. Examples of various types of preparation for local or transcutaneous administration include ointments, lotions, creams, gels, foams, preparations for delivery by transdermal patches, powders, sprays, aerosols, capsules or cartridges for use in a inhalator or insufflator or drops in the form, for example, of eye or nose drops, solutions and suspensions for nebulisation, suppositories, pessaries, retention enemas and chewable or suckable tablets or pellets. Active ingredients can also be contained in a liposome or microencapsulation preparation.
[0017] Ointments, creams and gels may, for example, be formulated with an aqueous or oil base with the addition of suitable thickening and/or gelling agent and/or solvents. Such bases may thus, for example, include water and/or an oil such as liquid paraffin or a vegetable oil such as arachis oil or castor oil, or a solvent such as polyethylene glycol. Thickening agents and gelling agents which may be used according to the nature of the base include soft paraffin, aluminum stearate, cetostearyl alcohol, polyethylene glycols, wool fat, bees wax, carboxypropyl methylene and cellulose derivatives and/or glyceryl monostearate and/or non-ionic emulsifying agents.
[0018] Lotions may be formulated with an aqueous or oily base and will, in general, also contain one or more emulsifying agents, stabilizing agents, dispersing agents, suspending agents or thickening agents.
[0019] Powder for external application may be formed with the aid of any suitable powder base, for example, talc, lactose or starch. Drops may be formulated with an aqueous or non-aqueous base also comprising one or more dispersing agents, solubilizing agents, suspending agents or preservatives.
[0020] Spray compositions may, for example, be formulated as aqueous solutions or suspensions or as aerosols delivered from pressurized packs, such as a metered dose inhaler with the use of a suitable liquified propellant. Aerosol compositions suitable for inhalation can be either a suspension or a solution and generally contain a composition of the active adrenal enzyme inhibitor in a suitable propellant such as a fluorocarbon or hydrogen-containing chlorofluorocarbon or mixtures thereof. The aerosol composition may optionally contain additional formulation expedience well-known to those in the arts such as surfactants, e.g. EXosurf™, a colfosceril palmitate cetyl alcohol tyloxapol, sold by Glaxo-Wellcome or lecithin and co-solvents, e.g. ethanol or other alcohols.
[0021] Capsules and cartridges for use in an inhaler or insufflator of, for example, gelatin, may be formulated containing a powder mix for inhalation of a compound of the invention and a suitable powder base such as lactose or starch. Each capsule or cartridge may generally contain between 10 to 1000 mg of the adrenal enzyme inhibitor. Alternatively, the active ingredients of the invention may be presented without expedience such as lactose.
[0022] The proportion of active ingredients and the local compositions according to the invention depends on the precise type of formulation to be prepared but generally will be within the range from 0.01 to 5.0% by weight. Generally, for most types of preparations, the preferred proportion will be within the range of from 0.1 to 2.0% by weight and preferably from 0.5 to 1.0% by weight.
[0023] Aerosol formulations are preferably arranged so that each metered dose or “puff” of aerosol contains 1 to 1000 micrograms, preferably about 10 to 200 micrograms of active ingredients. Administration may be 1 to 2000 micrograms
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A composition and method for inhibiting adrenal enzyme synthesis in a user in order to improve glucose tolerance, reduce obesity, reduce diabetes, reduce hypertension and reduce atherosclerosis. The preferred active ingredient is trilostane which is combined with a suitable carrier which acts as an adrenal enzyme inhibitor and is thus useful for treating diabetes mellitus, hypertension, obesity and atherosclerosis.
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This is a continuation, of application Ser. No. 08/166,432 filed Dec. 14, 1993, now abandoned.
FIELD OF THE INVENTION
The instant invention relates to producing perhalofluorobutanes and perhalofluorohexanes, more particularly it relates to their production by utilizing tetrafluoroethylene (hereinafter referred to as "TFE") and chlorotrifluoroethylene (hereinafter referred to as "CTFE") with selected perhalofluoroethanes containing 2 to 4 nonfluorine halogen substiutuents, and 2 to 4 fluorine substituents in the presence of a polyvalent metal halide such as an aluminum chloride or chlorofluoride as catalyst.
The perhalofluoroalkanes can be used as intermediates for the manufacture of hydrofluorobutanes which in turn in view of their inherently low ozone depletion potentials, are environmentally attractive alternatives for perchlorofluorocarbons (CFC's) in such established uses as refrigerants, expansion agents for making foams, aerosols, heat transfer media, propellants, solvents, cleaning and drying agents, gaseous dielectrics, power cycle working fluids, polymerization media, carrier fluids, fire extinguishants, among other applications.
BACKGROUND OF THE INVENTION
Joyce, U.S. Pat. No. 2,462,402 (Feb. 22, 1949) discloses a process for the production of highly halogenated fluoroalkanes which comprises contacting TFE with a polyhalogenated alkane, preferably a methane, containing at least one chlorine atom and no more than two fluorine atoms, in the presence of a polyvalent metal halide catalyst, preferably aluminum chloride.
Sievert, et. al., in U.S. Pat. No. 5,157,171 (Oct. 20, 1992) disclose a process for preparing chlorofluorinated propanes, CHCl2F5, by contacting monofluorodichloromethane (CHCl2F) with TFE in the presence of a modified aluminum chloride catalyst containing fluoride as well as chloride ligands.
The disclosure of the previously identified references is hereby incorporated by reference.
SUMMARY OF THE INVENTION
One aspect of the invention relates to a process for producing valuable perhalofluorobutanes from commercially available perhalofluoroethanes and polyfluoroethylenes such as tetrafluoroethylene (TFE) and chlorotrifluoroethylene (CTFE).
The inventive process relates to producing perhalofluorobutanes, where "halo" represents non-fluoro halogens, in particular Cl and/or Br, by reacting TFE and/or CTFE with one or more selected perhalofluoroethanes.
Broadly, the invention comprises:
(i) contacting
(a) CYF=CF 2 , where Y is Cl or F, with
(b) a perhalofluoroethane selected from the group comprising CX 2 FCX 2 F or CX 2 FCXF 2 or CF 3 CX 2 F or CBrF 2 CF 2X where X can be either Cl or Br, in the presence of
(c) a catalytically effective polyvalent metal halide, preferably aluminum chloride or aluminum chlorofluoride, at a temperature and pressure and for a time effective to produce
(d) a reaction product mixture containing at least one perhalofluorobutane selected from the group comprising C 4 YX 4 F 5 , C 4 YX 3 F 6 , C 4 BrYXF 7 , and C 4 YX 2 F 7 where Y and X are as defined above; and
(ii) recovering at least one of said perhalofluorobutanes from the reaction mixture.
The inventive process is capable of producing perhalofluorobutanes having the formula C4X2-5F5-8, X=Br or Cl, derived from perhalofluoroethanes as defined above by reaction with TFE that may be represented by the following equations (1)-(3):
CF2=CF2+C2X4F2, e.g. C2Cl4F2→C4X4F6, e.g., C4Cl4F6, (1)
CF2=CF2+C2X3F3, e.g. C2Cl3F3→C4X3F7, e.g., C4Cl3F7, (2)
CF2=CF2+C2X2F4, e.g. C2Br2F4→C4X2F8, e.g., C4Br2F8, (3)
wherein usually the fluorine content of each of the products C4X4F6, C4X3F7, and C4X2F8 is the sum of the fluorine contents of the TFE and perhalofluoroethane reactants.
Similarly, the inventive process is capable of producing perhalofluorobutanes having the formula C4X2-5F5-8, X=Br or Cl, derived from perhalofluoroethanes as defined above by reaction with CTFE that may be represented by the following equations (4)-(6):
CClF=CF2+C2X4F2→C4X5F5, (4)
CClF=CF2+C2X3F3→C4X4F6, (5)
CClF=CF2+C2X2F4→C4X3F7, (6)
wherein usually the fluorine content of each of the products C4X5F5, C4X4F6, and C4X3F7 is the sum of the fluorine contents of the CTFE and perhalofluoroethane reactants.
The reaction product mixture may contain products having fluorine content greater than the sum of the fluorine content of the starting materials. For example, the reaction of CCl2FCClF2 with TFE may yield in addition to C4Cl3F7, a C4Cl2F8 product, e.g., CF3CCl2CF2CF3. In some cases, a halogen exchange reaction may occur between the primary C4Cl3F7 product and the metal halide catalyst which contains fluorine ligands, either originally present or formed therein during the course of the reaction with a chlorofluoroethane reactant.
The reaction product mixture may also contain products having fewer fluorine groups than the sum of the fluorine groups in the starting materials. All such products with fluorine content greater or smaller than the sum of the fluorine content of the starting materials are also valuable products as they are also reducible to hydrogen containing products using known techniques, e.g., converting at least one carbon-nonfluorine halogen bond to a carbon-hydrogen bond.
When using starting materials corresponding to CX2FCX2F, where X can be Cl and/or Br, the reaction product mixture may additionally contain products derived from reaction of at least two moles of fluoroolefin with one of the perhalofluoroethane. For example, C6Cl4F10 (C2F5CCl2CCl2C2F5) and C5Cl5F9 (CClF2CF2CCl2CCl2C2F5), may both originate from TFE and CCl2FCCl2F in the presence of an aluminum chloride or chlorofluoride catalyst. Without wishing to be bound by any theory or explanation, it is believed that the nonafluoride, e.g., C5Cl5F9, may result from a halogen exchange reaction of the intermediate C4Cl4F6, or first formed product C6Cl4F10, with the aluminum chloride catalyst. The halogen exchange reaction can be shown by the following equation (7);
2CF2=CF2+C2X4F2, e.g. C2Cl4F2→C6X4F10, e.g., C6Cl4F10,(7)
DETAILED DESCRIPTION
In accordance with the present invention perhalofluorobutanes, as defined above and generally as the major reaction products, can be prepared by reacting TFE or CTFE with selected perhalofluoroethanes in the presence of an effective metal halide such as aluminum chloride or chlorofluoride, as catalyst.
Such reactions illustrated by equations (1)-(6) above, indicate a stoichiometry of 1 mole of the fluoroolefin per mole of the perhalofluoroethane reactant. The reaction illustrated by equation (7) indicates a stoichimetry of 2 moles of fluoroolefin per mole of reactant. Generally, however, the mole ratio of starting materials or reactants may vary from about 0.3 to about 3.0 moles of the fluoroolefin per mole of the halofluoroethane reactant with about 1:1 being used typically for making perhalofluorobutanes, whereas 2:1 being used typically for making perhalofluorohexanes.
The catalyst is typically an anhydrous aluminum chloride or chlorofluoride wherein the fluorine content ranges from about 3 to 64% by weight, and is such that the composition corresponds to that of AlCl3-rFr wherein r is typically about 1 to about 2.8 (hereinafter referred to as a "modified aluminum chloride catalyst"). Such modified aluminum chloride catalytic compositions may be prepared by reacting anhydrous AlCl3 with an excess of at least one of chlorofluorocarbon, hydrochlorofluorocarbon, or hydrofluorocarbon as disclosed in Sievert, et. al. U.S. Pat. No. 5,157,171, the disclosure of which is incorporated herein by reference. It is, however, desirable to avoid formation of AlF3 because such a composition is not believed to be an active catalyst for the instant invention.
The quantity of modified aluminum chloride used in the present process may vary widely, but usually amounts to about 1 to about 20 mole percent based on the quantity of the perhalofluoroethane.
The inventive process can be conducted batchwise, or in a continuous manner. In the continuous mode, a mixture of perhalofluoroethane and fluoroolefin can be passed through or over a bed or body of the catalyst which may be under agitation at a suitable temperature and pressure to form a product stream, and the desired products are recovered from the stream. Such recovery can be performed by using conventional methods, e.g., fractional distillation.
In the batch process, the reactants and catalyst may be combined in a suitable reactor to form a reaction mixture and the mixture held, normally under agitation, at a suitable temperature and pressure, until a desired degree of conversion to the desired perhalofluorobutanes are attained. In one embodiment, the reactor is initially charged with the catalyst, optionally in the presence of a diluent, then the perhalofluoroethane and the fluoroolefin, as separate streams or as a combined streams, in a desired mole ratio, are fed into the reactor at a controlled rate and maintained therein until the reaction is complete. If the reactor is fed with perhalofluoroethane and catalyst in the substantial absence of fluoroolefin, the system (reactor and ingredients) should be kept relatively cold, e.g., between -78° C. and 10° C., to minimize reaction of the perhalofluoroethane with the catalyst, e.g., a halogen exchange reaction, or disproportionation to higher or lower perhalofluoroethanes.
The inventive process may be practiced with or without a solvent or reaction diluent. Such solvent or diluent, if used, must be substantially inert to the reactants and catalyst, and also should boil at a temperature that enables separation of the diluent from the reaction products. Representative of such diluents can be at least one of CCl4, CF3CHCl2, CCl3CF3, CF3CCl2CF3, the perhalofluorobutane products of the present inventive process, e.g., CClF2CCl2C2F5, CF3CBr2C2F5, CF3CCl2C2F5, isomers thereof, among others.
The reaction temperature may be varied, and normally is in the range of from about 0° C. to about 150° C.; typically in the range of from about 20° C. to about 110° C.
The reaction pressure likewise may vary widely from subatmospheric to superatmospheric, but typically the reaction is carried out at somewhat elevated pressures, particularly at pressures generated autogenously in conformity with the reaction temperature employed. The pressure may be controlled by adjusting the amount of unreacted perhalofluoroethane and fluoroolefin.
The reaction time, or time necessary for substantially complete reaction, can be dependent on the temperature chosen for the reaction; generally the higher the temperature the shorter the reaction time. The completion of the reaction, however, can be determined by the change in the autogenous pressure in the reaction vessel, because the pressure drops as the reaction proceeds, so that the time at which the pressure stops decreasing can be taken as the end of the reaction period. Generally, the reaction time ranges of from about 0.25 h to about 6.0 hours.
The reaction time can vary with the volume of the reactor and/or quantity of reactants.
The products of the reaction may be recovered from the reactor by conventional means such as filtration, distillation, among other conventional means. It is usually convenient to decompose the catalyst by treatment with water, and then recover the desirable reaction product by distillation.
The perhalofluoroethane starting materials for the process of this invention are selected from one or more of CCl2FCCl2F, CClF2CCl2F, CCl2FCF3, CBr2FCF3, CBrClFCF3, CBrF2CBrF2, and CBrF2CClF2. The fluoroolefin starting materials for the process of this invention are selected from one or more of CTFE (CClF=CF2) and TFE (CF2=CF2). The combination of these perhalofluoroethane starting materials with these fluoroolefin starting materials in the presence of aluminum chloride or modified aluminum chloride catalyst affords perhalofluoroalkane reaction products selected from one or more of
C4Cl5F5 isomers including C2Cl5C2F5; C4Cl4F6 isomers including CClF2CCl2CF2CClF2 and CClF2CCl2CClFCF3; C4Cl3F7 isomers including CClF2CCl2C2F5; CF3CCl2CF2CClF2, and CF3CCl2CClFCF3; C4Cl2F8 isomers including CF3CCl2C2F5; C4BrClF8 isomers including CF3CBrClC2F5; C4Br2C2F5 isomers including CF3CBr2C2F5; C6Cl5F9 isomers including CClF2CF2CCl2CCl2C2F5; and C6Cl4F10isomers including C2F5CCl2CCl2C2F5;
The following perhalofluoroalkanes reaction products are new compositions of matter:
C2Cl5C2F5, CF3CCl2CF2CClF2, CF3CBrClC2F5, CF3CBr2C2F5, CClF2CF2CCl2CCl2C2F5, and C2F5CCl2CCl2C2F5.
All of the above perhalofluoroalkanes can be used for making hydrofluorocarbons (HFCs) such as hydrofluoroalkanes, e.g., at least one of hydrofluorobutanes and hydrofluorohexames.
If desired, the perhaloproducts of the inventive process may be hydrodehalogenated to hydro-derivatives comprising at least one hydrogen substituent and correspondingly one less nonfluorohalogen substituent than present in the starting perhalofluorocarbon by being treated with one or more reducing means. Examples of suitable reducing means comprise least one of photochemical, chemical, and normally catalytic hydrogenation means. Catalytic hydrogenation may generally be effected with molecular hydrogen over a suitable catalyst, typically a Group VIII metal, as disclosed, for example, in Smith, U.S. Pat. No. 2,942,036 and Rao, U.S. Pat. No. 5,136,113; the entire disclosures of which are incorporated herein by reference.
Catalytic hydrogenation can be practiced in the liquid or vapor phase. Normally, the vapor phase is employed with a catalytic metal such as palladium that can be supported on carbon or alumina. Catalytic hydrogenation may generally be effected with molecular hydrogen over a suitable catalyst, typically a Group VIII metal, as disclosed, for example, in Smith, U.S. Pat. No. 2,942,036 and Rao, U.S. Pat. No. 5,136,113 which disclosures are incorporated herein by reference.
Hydrogenation can also be conducted in the vapor phase with a catalytic metal such as nickel, palladium, platinum, rhodium or iridium, among others. The catalytic metal is normally supported on a suitable carrier such as carbon or alumina.
The hydrodehalogenation reactions of the present invention may be conducted at temperatures between about 25° C. and 250° C., normally between about 50° C. and 200° C., and typically between about 100° C. and 200° C. The choice of optimum hydrodehalogenation temperature will be dictated by whether the halogen being removed or replaced is chlorine or bromine, the desired degree of conversion of the perhalofluoroalkane starting material, the percent loading of the active metal upon the support, among other factors. Perbromofluoroalkanes are more readily hydrodehalogenated than are perchlorofluoroalkanes.
The hydrodehalogenation reactions may be operated at pressures between atmospheric and 100 psig or higher. The choice of pressure may be dictated by the vapor pressure of the reactants, intermediates, and products.
The ratio of hydrogen to perhalofluoroalkane employed in the dehydrohalogenation reaction may vary from about 0.5 to about 10 on a molar basis, and usually should be from about 1 to 4. Relatively large excesses of hydrogen can be employed. A deficiency of hydrogen may be used to control the conversion rate of the perhalofluoroalkane if desired.
Chemical reducing means may also include reduction with zinc in the presence of an alcohol as disclosed, for example, by Morikawa, et. al., in International Patent Application 90/08753 and by Krespan in U.S. Pat. No. 4,935,558; reduction with complex metal hydrides as disclosed by Clayton in European Patent Application 0 508,631; reduction with hydrogen iodide or with H2 in the presence of iodine or hydrogen iodide as disclosed by Anton in U.S. Pat. No. 5,208,396; the entire disclosure of these patent documents is hereby incorporated by reference.
Photochemical means include reaction of the perhalocompound with alcohols in the presence of ultraviolet light as disclosed by Posta, et. al., in Czechoslovak Patent 136,735.
Hydrofluoroalkanes produced by hydrodehalogenation of the perhalofluoroalkanes listed above include those selected from one or more of
C4H5F5 isomers including C2H5C2F5 and CHF2CH2CH2CF3; C4H4F6 isomers including CHF2CH2CF2CHF2, CHF2CH2CHFCF3, and CF3CH2CH2CF3; C4H3F7 isomers including CHF2CH2C2F5; CF3CH2CF2CHF2, and CF3CH2CHFCF3; C4H2F8 isomers including CF3CH2C2F5; C6H5F9 isomers including CHF2CF2CH2CH2C2F5; C6H4F10 isomers including C2F5CH2CH2C2F5;
The following hydrofluoroalkanes hydrodehalogenation products are new compositions of matter:
CHF2CH2CH2CF3, CHF2CH2CHFCF3, CHF2CH2C2F5, CHF2CF2CH2CH2C2F5. All of the hydrogenated alkanes can be used in the manner described above in connection with HFCs such as a refrigerant, cleaning and blowing agents, among other applications.
The various embodiments of this invention may be more readily understood by consideration of the following examples which are being provided to illustrate not further limit that scope of the invention.
Examples 1 to 7 exemplify the reaction of TFE with CCl2CCl2F, CCl2FCClF2, CCl2FCF3, CBrF2ClF2, CBrF2CBrF2, and CBr2FCF3.
Examples 8 and 9 exemplify the reaction of CTFE with CCl2FCClF2 and CCl2FCF3.
Example 10 illustrates the hydrodebromination of CF3CBr2CF2CF3 to CF3CH2CF2CF3.
Analyses of reaction products, generally mixtures, were carried out using standard GC/GC-MS and 19F NMR methods, the abbreviations GC, GC-MS, and NMR standing for gas chromatography, gas chromatography-mass spectrometry, and nuclear magnetic resonance spectroscopy. Results are presented in GC area percents unless otherwise indicated with amounts less than about 1% generally omitted.
EXAMPLE 1
Reaction of CCl2FCCl2F with TFE
A 400 mL "Hastelloy" C shaker tube was charged with 3 g of CCl3F-modified aluminum chloride, 30 g (0.15 mole) of CCl2FCCl2F, and 30 g of CHCl2CF3 as a diluent. The reactor was sealed, cooled to -78° C., evacuated, and purged with nitrogen three times. The reactor was then placed in the autoclave, agitated, charged with 11 g (0.11 mole) of TFE, and heated to 42° C. over the course of 45 minutes (pressure reached 101 psig). An additional 14 g (0.25 mole total) of TFE were added over the course of 1 h at a temperature of 38-49° C.; uptake of TFE was obvious from the drop in pressure after each addition of TFE. Agitation and heating were stopped after an additional 6 h (final pressure 46 psig at 40° C.). The product consisted of clear supernatant over a flocculent brown solid (total weight 79.5 g). Analysis of the product by GC and GC-MS indicated the following major products:
______________________________________Component GC Area %______________________________________C4F8 0.09 C2Cl2F2 0.1 CHCl2CF3 31.3 CCl3CF3 0.2 C2F5CCl2C2F5 0.05 CCl3C2F5 0.1 C6Cl2F10 0.05 C4Cl2F6 0.9 CCl3CClF2 2.9 CCl2═CCl2 0.09 CClF2CCl2CF2CClF2 14.5 C2F5CCl2CCl2C2F5 46.2 CCl3CCl2CF2CF3 0.3 CClF2CF2CCl2CCl2C2F5 1.3______________________________________
Products CClF2CCl2CF3CF3 (C4Cl4F6) and CCl3CCl2CF2CF3 (C4Cl5F5) are evidently formed by condensation of one mole of TFE with CCl2FCCl2F, with C4Cl5F5 being the result of halogen exchange between C4Cl4F6 and the aluminum halide catalyst. The C6Cl4F10 and C6Cl5F9 products evidently derive from two moles of TFE condensing with CCl2FCCl2F, with C6Cl5F9 also a product of halogen exchange between C6Cl4F10 and the aluminum halide catalyst.
The modified aluminum chloride catalyst of Example 1 was prepared as follows:
A 1 L four neck round bottom flask was charged with 150 g of aluminum chloride (AlCl3) in a dry box. The flask was passed out of the dry box and fitted with an addition funnel, a mechanical stirrer, a thermocouple, and a dry ice condenser connected to a nitrogen bubbler. The addition funnel was charged with about 525 g of CCl3F and the condenser was filled with a methanol/dry ice mixture. The CCl3F was added to the flask over the course of about 3.5 h. After the addition was complete, the mixture was stirred for 1 h and then volatiles were removed in vacuum. The resulting solid was dried under dynamic vacuum. Analysis: weight % Al=33.4; weight % F=44.7. The fluorine analysis data suggests the composition of the catalyst is approximately AlC10.6F2.3.
EXAMPLE 2
Reaction of CCl2FCClF2 with TFE
A 400 mL "Hastelloy" C shaker tube was charged with 3 g of CCl3F-modified aluminum chloride. The reactor was sealed, cooled to -78° C., evacuated, purged with nitrogen three times, and charged with 60 g (0.32 mole) of CCl2FCClF2. The reactor was then placed in the autoclave, agitated, charged with 11 g (0.11 mole) of TFE, and heated to 31° C. over the course of 45 minutes (pressure reached 5 psig). An additional 16 g (0.27 mole total) of TFE were added over the course of 1.5 h and the temperature was increased to 38° C. (69 psig). Agitation and heating were stopped after an additional 4 h (final pressure 38 psig at 39° C.). The product consisted of clear supernatant over a yellow solid (total weight 74.2 g). Analysis of the product by GC, GC-MS, and 19F NMR indicated the following major products in the Table below.
______________________________________Component GC Area % Mole %______________________________________CF2═CF2 0.3 -- C4F8 0.1 -- C6F12 0.3 -- C8F16 0.07 -- C6ClF11 (3 isomers) 0.4 -- CF3CCl2C2F5 3.8 3.3 CCl3CF3 26.0 35.6 C6Cl2F10 (2 isomers) 0.3 -- CClF2CCl2C2F5 57.2 48.8 CClF2CF2CCl2CF3 * 2.4 CF3CClFCCl2CF3 * 1.5 C4Cl4F6 6.6+ 4.4** C4Cl5F5 3.4 + 4.0**______________________________________ + Determined by GCMS **Structure indicated by 19F NMR
The modified aluminum chloride catalyst of Example 2 was prepared as follows:
A 500 mL three neck round bottom flask containing a PTFE-coated stirring bar was charged with 50 g of aluminum chloride (AlC3) in a dry box. The flask was passed out of the dry box and fitted with an addition funnel and a dry ice condenser connected to a nitrogen bubbler. The addition funnel was charged with 175 mL of CCl3F and the condenser was filled with a methanol/dry ice mixture. The CCl3F was gradually added to the flask and the mixture began to reflux vigorously. The reaction continued to reflux for a hour after all of the CCl3F had been added. The reaction was not heated. Volatiles were removed in vacuum. The resulting solid was dried under dynamic vacuum to afford 35 g of off-white powder. Analysis: weight % F=47.7; weight % Al=26.6; this corresponds to a composition that is approximately AlClF2.
EXAMPLE 3
Reaction of CCl2FCF3 with TFE
A 400 mL "Hastelloy" C shaker tube was charged with 6 g of CCl3F-modified aluminum chloride. The reactor was sealed, cooled to -78° C., evacuated, purged with nitrogen three times, and charged with 80 g (0.47 mole) of CCl2FCF3. The reactor was then placed in the autoclave, agitated, charged with 10 g (0.10 mole) of TFE, and heated to 60° C. over the course of 20 minutes (pressure reached 50 psig). An additional 30 g (0.40 mole total) of TFE were added over the course of 0.5 h as the pressure rose to 162 psig. Agitation and heating were stopped after an additional 6 h (final pressure 127 psig at 60° C.). The product consisted of clear supernatant over a flocculent brown solid (total weight 93.2 g); after filtration and drying the solid was found to weigh 10.1 g. Analysis of the clear supernatant by GC, GC-MS, and 19F NMR indicated the following major products in the Table below.
______________________________________Component GC Area %______________________________________CCl2CF3 13.5 CF3CCl2C2F5 80.9 CCl3CF3 3.6______________________________________
The modified aluminum chloride catalyst used in this Example was prepared by substantially in accordance with the method described in Example 1 with the exception that 410 g of CCl3F were added to the AlCl3 over the course of 0.3 h.
EXAMPLE 4
Reaction of CBrF2CClF2 with TFE
A 400 mL "Hastelloy" C shaker tube was charged with aluminum chloride (2 g, 0.015 mole) and 59 g of CHCl2CF3 (40 mL, present as a diluent). The tube was sealed, cooled to -78° C., evacuated, and purged with nitrogen three times. The reactor was then charged with CBrF2CClF2 (22 g, 0.10 mole). The cold reactor was placed in the barricade and charged with 15 g (0.15 mole) of TFE, warmed to 80° C., and held at that temperature for 6 h. The pressure quickly rose to 163 psig and then fell off to 89 psig at the end of the reaction period. The following day the reactor was discharged to afford 73.7 g of a yellow supernatant over a dark solid (75% recovery). Analysis of the product by GCand GC-MS indicated the composition given in the table below.
______________________________________Component GC Area %______________________________________C2HF5 0.4 C2BrF5 0.2 C4ClF7 0.4 C2BrClF4 2.9 CHCl2CF3 68.6 CF3BrClCF2CF3 19.6 CBrCl2CF3 2.3 CBr2ClCF3 0.3 CCl2═CCl2 1.6 C5BrClF10 0.4______________________________________
The identity of the major products was confirmed by the 19F NMR spectrum of a distillation cut in which the C4BrClF8 component concentration was about 79%.
EXAMPLE 5
Reaction of CBrF2CBrF2 with TFE
A 400 mL "Hastelloy" C shaker tube was charged with 3 g of CCl3F-modified aluminum chloride (E65330-70). The reactor was sealed, cooled to -78° C., evacuated, and charged with 50 g (0.19 mole) of CBrF2CBrF2. The reactor was purged with nitrogen three times, placed in the autoclave, and agitated. 21 g (0.21 mole) of TFE were added and the reactor was heated to 100° C. The temperature was held at 99-100° C. for 4 h; the pressure in the reactor gradually increased to 40 psig. Upon opening the reactor, 70.4 g (95% recovery) of product were obtained which consisted of an amber liquid over a dark solid. Analysis of the product by GC and GC-MS indicated the following major products in the Table below. The 19F NMR spectrum of the product verified the presence of CF3CBr2CF2CF3; and excluded the possibility of CBrF2CBrFCF2CF3 as a major product; nine additional minor impurities were observed, but not identified.
______________________________________Component GC Area %______________________________________C4F8 0.5 C6F12 1.5 C8F16 0.2 C4BrF9 0.1 C4BrF7 isomer 0.2 C4BrF7 isomer 0.3 C6BrF11 isomer 2.3 C6BrF11 isomer 0.6 C6BrF11 isomer 0.8 C6BrF11 isomer 0.4 C8BrF15 isomer 0.7 C8BrF15 isomer 0.4 CF3CBr2CF2CF3 89.1 C6BrClF10 0.2 C8BrClF14 0.2______________________________________
The modified aluminum chloride catalyst used in Example 5 was prepared by a procedure similar to that described in Example 2. Analysis: weight % Al=27.7; this corresponds to a composition that is approximately AlC10.8F2.2.
Without wishing to be bound by any theory or explanation, it is believed that the starting material is being isomerized under the reaction conditions to an intermediate product, e. g. , CF3CBr2F, that in turn reacts with TFE to form a reaction product comprising CF3CBr2CF2CF3. This Example demonstrates that a perhalofluoroethane having a CF2XCF2X structure reacts with a fluoroolefin, e.g., TFE, to form a CF3CX2CF2CF3 structure, where X can be Cl and/or Br such that at least one X is Br.
EXAMPLE 6
Reaction of CBrF2CBrF2 with TFE in the presence of AlCl3
A 400 mL "Hastelloy" C shaker tube was charged with 2 g (0.015 mole) of aluminum chloride and 120 g (0.46 mole) of CBrF2CBrF2. The reactor was cooled, evacuated, purged with nitrogen three times, placed in the autoclave, and agitated. TFE (10 g, 0.10 mole) were added to the reactor was heated to 103° C. over the course of 0.25 h. An exotherm occurred at this point which resulted in a decrease in pressure from 50 to 35 psig. An additional 40 g of TFE were added over the next 0.5 h in such a way that the pressure did not exceed 150 psig. The temperature was held overnight at 99-100° C. Upon discharge, 151.8 g of product were obtained which consisted of a yellow-orange supernatant over a dark solid. Analysis of the product by GC and GC-MS indicated the following major products:
______________________________________Compound GC Area %______________________________________C4BrClF8 2.9 CF3CBr2C2F5 82.9 C2Br2ClF3 1.3 C2Br3F3 5.2______________________________________
EXAMPLE 7
Reaction of CBr2FCF3 with TFE
Following a procedure similar to that above, a 400 mL "Hastelloy" C reactor was charged with CBr2FCF3 (50 g, 0.19 mole), CCl3F-modified aluminum chloride (2 g; see Example 2), and TFE (21 g, 0.21 mole). The reactor heated at 74-95° C. for 6 h; the pressure changed from 55 psig to 44 psig during this time. The product (66.3 g) consisted of a yellow supernatant over a tan solid. GC/GC-MS analysis indicated that the product was 96% CF3CBr2C2F5.
EXAMPLE 8
Reaction of CCl2FCClF2 with CTFE
A 400 mL "Hastelloy" C shaker tube was charged with 2 g of CFC-11-modified aluminum chloride (see Example 1). The reactor was sealed, cooled to -78° C., evacuated, purged with nitrogen three times, and charged with 74 g (0.40 mole) of CCl2FCClF2 and 23 g (0.20 mole) of CTFE. The reactor was then placed in the autoclave, agitated, and heated to 48° C. over the course of about 0.5 h (pressure reached 30 psig). The temperature was adjusted to 39-40° C. and held for 6 h; the final pressure was 20 psig. The product consisted of clear supernatant over a brown solid (total weight 91.8 g). Analysis of the product by GC and GC-MS indicated the following major products:
______________________________________Component GC Area %______________________________________CClF═CF2 5.0 cyclo-CClFCClFCF2CF2-- 5.3 CCl2FCClF2 46.0 CCl3CClF2 0.2 C4Cl4F6 42.7 C4Cl5F5 0.6______________________________________
The product was washed twice with water and the organic layer placed in a distillation flask connected to a seven inch 12 mm i.d. vacuum-jacketed column packed with 1/4 inch glass helices and topped with a water-cooled cold finger head. The product was distilled at atmospheric pressure and three fractions collected. The composition of the first fraction (head temp ambient -48° C.) and the third fraction (head temperature 130-133° C.) were determined by 19F NMR (see below).
19 F NMR Analysis of Distillation Fractions
______________________________________ Mole PercentComponent Fraction 1 Fraction 3______________________________________cyclo-CClFCClFCF2CF2-- cis isomer 2.3 0.1 trans isomer 1.8 0.1 CCl2FCClF2 80.8 0.4 CCl3CF3 15.1 0.04 CClF2CCl2CF2CClF2 46.7 CClF2CCl2CClFCF3 44.5 CF3CCl2CCl2CF3 4.5 CClF2CClFCCl2CF3 3.7______________________________________
EXAMPLE 9
Reaction of CCl2FCF3 with CTFE
A 400 mL "Hastelloy" C shaker tube was charged with 2 g of CCl3F-modified aluminum chloride (Example 1) and 25 g (0.16 mole) of CHCl2CF3. The reactor was sealed, cooled to -78° C., evacuated, purged with nitrogen three times, and charged with 34 g (0.20 mole) of CCl2FCF3 and 23 g (0.20 mole) of CTFE. The reactor was then placed in the autoclave, agitated, and heated to 50-51° C. over the course of about 1 h (pressure reached 65 psig). The temperature was held at 50-51° C. and held for 4 h; the final pressure was 75 psig. The product consisted of clear supernatant over a dark solid (total weight 61.1 g). Analysis of the product by GC, GC-MS, and 19F NMR indicated the following major products:
______________________________________Component GC Area % Mole %______________________________________CF3CCl2F 3.4 6.4 CClF2CClF2 * 0.5 CHCl2CF3 38.0 54.6 cyclo-C4Cl2F6 27.4 17.4 CCl3CF3 0.3 -- CClF2CF2CCl2CF3 29.8 10.9 CF3CCl2CClFCF3 * 10.2 CClF2CF2CCl3 0.7 --______________________________________ *Not separated from its isomer on the GC column utilized.
EXAMPLE 10
Hydrogenation of CF3CF2CBr2CF3 over Pd/Al2O3 Catalyst
A 15 inch (38.1 cm) by 3/8 inch (0.95 cm) "Hastelloy" nickel alloy tube is filled with about 3.48 gm (about 6.0 cc) of about 0.5% Pd/Al2O3 (Calsicat 1/8" pellets #64A-057) ground to 4/10 mesh.
The catalyst is activated by heating at about 100° C. for about 50 min. under a hydrogen flow of about 50 sccm (8.3×10-7 m3/s). The temperature of the reaction is raised to about 150° C. while decreasing the flow of H2 to about 20 sccm (3.3×10-7 m3/s) and increasing the flow of CF3CF2CBr2CF3 to about 10.0 sccm (1.7×10-7 m3/s). The gaseous effluent is CF3CF2CH2CF3.
While certain aspects of the invention have been described in particular detail, a person having ordinary skill in this art will recognized that other aspects and embodiments are encompassed by the appended claims.
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The instant invention relates to producing perhalofluorobutanes and perhalofluorohexanes, more particularly it relates to their production by utilizing tetrafluoroethylene (hereinafter referred to as "TFE") and chlorotrifluoro-ethylene (hereinafter referred to as "CTFE") with selected perhalofluoroethanes containing 2 to 4 nonfluorine halogen and 2 to 4 fluorine substituents in the presence of a polyvalent metal halide such as an aluminum chloride or chlorofluoride as catalyst.
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[0001] This application claims priority from Canadian Patent Application No. 2,411,955, filed Nov. 15, 2002, the disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates to the field of embroidery machines, and more specifically, to a system and method for reducing thread breakage due to needle puncture during the embroidery process.
BACKGROUND OF THE INVENTION
[0003] Industrial high-speed embroidery machines generally have a workpiece support table which is mounted for movement along several axes relative to a needle carrying sewing head. The support table is driven by stepper motors which are responsive to signals from a computer control system. The signals are generated according to a digitized pattern. The workpiece is then moved under the sewing instruments through a desired path.
[0004] Typically, the sewing head includes a drive shaft to vertically reciprocate a swingable needle to penetrate a fabric to be embroidered and also to reciprocate a thread take-up lever to supply an upper thread from a supply and to tighten a stitch to be formed.
[0005] Thread breakage is a significant problem in high speed embroidering systems. It is estimated that thread breakage occurs once every few minutes in a 1000 stitch per minute machine. Effective upper thread tension control is considered important to achieving accurate stitching. If the upper thread tension is not properly controlled prior to needle penetration, thread breakage can occur. In particular, if there is too much slack in the upper thread, thread can wrap around the point of the needle, prevent loop seizure, break the thread, or interfere with correct stitch formation.
[0006] Several devices are known for controlling upper thread tension and hence for preventing thread breakage, as for example U.S. Pat. Nos. 4,320,712, 4,590,879 and 4,616,583.
[0007] Other systems for reducing thread breakage function by controlling the position of the needle thread relative to the descending needle to avoid contact between the two. For example in U.S. Pat. No. 4,706,589 to Tsukioka, a needle thread guide is disclosed for a button holing sewing machine. The needle thread guide is provided at the needle bar frame and located adjacent to the needle entry protects the needle thread from being struck by the needle when the workpiece is fed during button holing. The guide guides the needle thread outwardly when the needle descends, thus the needle thread positioned lower than the needle eye is protected from being struck by the needle. The guide is associated with the oscillating motion of the needle, but its direction of oscillation is opposite to the direction of needle oscillation, and its amplitude is almost twice the amplitude of the needle. A similar thread deflection device for zigzag stitching is disclosed in U.S. Pat. No. 4,949,657 to Hanyu, et al.
[0008] One shortcoming of these devices is that their mechanics limit their ability to effectively adapt to varying stitch and workpiece characteristics prevalent in modem high speed automated embroidery machine applications.
[0009] A need therefore exists for an improved method and system for reducing thread breakage due to the needle contacting the needle thread as it penetrates the fabric and that allows for the effective adaptation to varying stitch and workpiece characteristics and that is not limited by sewing machine mechanics.
SUMMARY OF THE INVENTION
[0010] The invention provides a method of preventing needle thread breakage between the needle and workpiece of an automated embroidery machine system by introducing an indirect path between a first needle penetration point and a next needle penetration point in the workpiece. The characteristics of the indirect path are determined by a sequence of instructions stored in the data processing system associated with the automated embroidery machine system. An advantage of the present invention is that it requires minimal or no modification of existing automated embroidery machine mechanics.
[0011] According to one aspect of the invention, a method is provided for minimizing contact between a needle point and a needle thread in a computer controlled embroidery machine, to prevent breakage of the needle thread by the needle point upon penetration of a workpiece by the needle during stitching. The method includes the steps of: determining a first straight path between a current needle penetration location and a next needle penetration location; and, moving to the next needle penetration location along a second non-straight path so that the needle thread is pulled away from the needle point.
[0012] Preferably, the method further includes the steps of: determining a probability of needle thread breakage for the first straight line path; and, selecting said second non-straight path if the probability is within a predetermined range.
[0013] Preferably, the shape of the second non-straight path is variable. Preferably, the shape of the second non-straight path includes sinusoids, curves, arcs, and straight lines. Preferably, the shape is modified in response to variables including thread tension, thread strength, thread diameter, stitch length, workpiece thickness, workpiece material, sewing speed, acceleration, speed of movement, and the distance between the needle point and the workpiece.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The invention may best be understood by referring to the following description and accompanying drawings which illustrate the invention. In the drawings:
[0015] [0015]FIG. 1A is a perspective view illustrating a first automated embroidery machine system in accordance with the prior art;
[0016] [0016]FIG. 1B is a perspective view illustrating a second automated embroidery machine system in accordance with the prior art;
[0017] [0017]FIG. 1C is a perspective detail view illustrating the stitching instruments and bobbin assembly of the automated embroidery machine system of FIG. 1B;
[0018] [0018]FIG. 1D is a perspective detail view illustrating the stitching instruments of the automated embroidery machine system of FIG. 1B;
[0019] [0019]FIG. 2 is a block diagram of an exemplary data processing system for implementing the invention according to one embodiment;
[0020] [0020]FIGS. 3A and 3B are top views illustrating the positional relationship between needle thread, needle eye, direction of threading into the needle eye, and the position of an operator in accordance with the prior art;
[0021] [0021]FIGS. 3C and 3D are side views corresponding to FIGS. 3A and 3B, respectively;
[0022] [0022]FIG. 4 is a top view illustrating an embroidery machine needle and areas about the needle of differing thread breakage probability in accordance with one embodiment of the invention;
[0023] [0023]FIG. 5 is a graph illustrating direct and indirect paths for workpiece movement between needle penetration locations in accordance with one embodiment of the invention; and,
[0024] [0024]FIG. 6 is a flow chart illustrating a general method for guiding a needle thread for an automated embroidery machine to prevent breakage of the needle thread by the point of the needle according to one embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] In the following description, numerous specific details are set forth to provide a thorough understanding of the invention. However, it is understood that the invention may be practiced without these specific details. In other instances, well-known software, circuits, structures and techniques have not been described or shown in detail in order not to obscure the invention. The term data processing system is used herein to refer to any machine for processing data, including the computer and control systems described herein. In the drawings, like numerals refer to like structures or processes.
[0026] Referring to FIG. 1A, there is shown a perspective view illustrating a first automated embroidery machine system in accordance with the prior art. In FIG. 1A, the automated embroidery machine system is shown generally by the numeral 100 . The automated embroidery machine system 100 includes an embroidery machine 1 mounted on a plateform 2 in operative association with a movable workpiece support table 3 . The workpiece support table 3 is moved under the stitching instruments 4 along tracks 5 and 6 by stepping motors 7 and 8 . Data processing system 200 generates signals to activate motors 7 and 8 to move workpiece support table 3 through a path determined by a digitized embroidery pattern which is input to data processing system 200 . The stitching instruments 4 generally consist of needle 10 , presser foot 11 , thread feed 14 , and a bobbin assembly (not shown) located underneath the workpiece support table 3 . Presser foot 11 is reciprocated by a cam in timed relation with needle 10 and may be retracted at the end of the sewing operation by air cylinder 12 . Generally, presser foot 11 has an opening 13 through which needle 10 passes during the stitching operation. Thread feed 14 consists of a variety of eyes and pulleys and generally guides thread 15 from a supply spool (not shown) through a variable tension device 16 to the needle 10 .
[0027] Referring to FIG. 1B, there is shown a perspective view illustrating a second automated embroidery machine system 1100 in accordance with the prior art. In addition, FIGS. 1C and 1D are perspective detail views illustrating the stitching instruments 4 and bobbin assembly 1009 and the stitching instruments 4 , respectively, of the automated embroidery machine system 1100 of FIG. 1B. Rather than using tracks 4 , 6 and stepping motors 7 , 8 , the second automated embroidery machine system 1100 may use more modern linear or servo motors. In addition, the second automated embroidery machine system 1100 may use multiple stitching instrument heads 1101 , 1102 , each containing multiple stitching instruments 4 , along with tensioners including eyes, pulleys, and guides.
[0028] Referring to FIG. 2, there is shown a block diagram of an exemplary data processing system for implementing the invention according to one embodiment. In FIG. 2, the exemplary data processing system is shown generally by the numeral 200 . The data processing system 200 includes an input device 210 , a central processing unit or CPU 220 , memory 230 , a display 240 , and an embroidery machine interface 250 . The input device 210 may be a keyboard, mouse, trackball, or similar device. The CPU 220 may include dedicated coprocessors and memory devices. The memory 230 may include RAM, ROM, databases, or disk devices. The display 240 may include a computer screen or terminal device. And, the embroidery machine interface 250 may include inputs and outputs for receiving and sending data and commands to and from the embroidery machine 1 and its stepping motors 7 and 8 . The data processing system 200 has stored therein data representing sequences of instructions which when executed cause the method described herein to be performed. Of course, the data processing system 200 may contain additional software and hardware a description of which is not necessary for understanding the invention.
[0029] Referring to FIGS. 3A and 3B, there are shown top views illustrating the positional relationship between needle thread 24 , needle eye 2 a , direction of threading into the needle eye 2 a , and the position of an operator M in accordance with the prior art. Referring to FIGS. 3C and 3D, there are shown side views corresponding to FIGS. 3A and 3B, respectively. The needle eye 2 a of needle 10 is threaded by a needle thread 24 which has a portion of the needle thread 24 a which is positioned above the needle eye 2 a , and a portion of needle thread 24 b which is positioned below the needle eye 2 a . Under such a positional relationship, when a workpiece 22 is fed in the direction of D, the needle thread portion 24 b positioned below the needle eye 2 a is positioned toward the operator's side M in relation to the needle's position as shown in FIGS. 3A and 3C. By contrast, when the workpiece 22 is fed in the direction of C, the needle thread portion 24 b positioned below the needle eye 2 a is positioned partly toward the rear side of the needle and away from the operator's side as shown in FIGS. 3B and 3D. Therefore, it is possible that the needle 10 sticks the needle thread portion 24 b when the needle 10 descends, thereby cutting the needle thread 24 .
[0030] Referring to FIG. 4, there is shown a top view illustrating an embroidery machine needle 10 and areas about the needle of differing thread breakage probability in accordance with one embodiment of the invention. As a workpiece 22 mounted on workpiece support table 3 is moved under the control of data processing system 200 in direction C, from a first needle penetration location A to a next needle penetration location B along a path 460 , the probability of breakage of the needle thread 24 varies. The probability of needle thread breakage decreases as the location of the next needle penetration location B shifts to the left right side 410 or left side 420 of the operator M with respect to direction C and the needle eye 2 a . The highest probability of breakage area 430 is aligned with direction C and the needle eye 2 a . Areas of decreasing probability of thread breakage 440 , 450 are found to the left and right of direction C and the needle eye 2 a.
[0031] Referring to FIGS. 1A through 4, according to the present invention, sequences of instructions are stored in the memory 230 of data processing system 200 to control stepping motors 7 and 8 through interface 250 to move workpiece 22 mounted on workpiece support table 3 from the first needle penetration location A to the next needle penetration location B along an indirect path 470 . By moving the workpiece 22 along an indirect path 470 between needle penetration locations A, B, the needle thread portion 24 b positioned below the needle eye 2 a is guided away from the needle point thus preventing breakage by the needle point upon penetration of the workpiece 22 by the needle 10 during stitching.
[0032] Referring to FIG. 5, there is shown a graph illustrating direct and indirect paths 460 , 470 for workpiece movement between needle penetration locations A, B in accordance with one embodiment of the invention. In FIG. 5, first needle penetration location A is shown at the origin of the x and y axes in the plane of the workpiece 22 . Next needle penetration location B is shown at a point along the y-axis. In effect, the selection of an indirect path 470 introducing a component of movement to the path from A to B along the x-axis. This movement along the x-axis allows needle thread portion 24 b to slide along the needle below the needle eye 2 a away from the needle point. In this way, the needle thread portion 24 b positioned below the needle eye 2 a is guided away from the needle point thus preventing breakage by the needle point upon penetration of the workpiece 22 by the needle 10 during stitching.
[0033] Selection of an indirect path 470 is optional. In addition, the shape of the indirect path 470 is variable. The data processing system 200 determines the need for an indirect path based on factors including the location of needle penetration locations A, B relative to the direction of threading through the needle eye 2 a . Typically, an indirect path 470 would be selected by the data processing system 200 for next needle penetration locations B lying in areas of high probability of needle thread breakage 430 as illustrated in FIG. 4. The data processing system 200 may determine the shape of the indirect path 470 based on factors including the probability of needle thread breakage. Thus, for next needle penetration locations B lying in a high probability of needle thread breakage area 430 the degree of distortion of the indirect path 470 may be greater than the degree of distortion of the indirect path for next needle penetration locations B located in areas of decreasing probability of needle thread breakage 440 , 450 . The shape of the indirect path 470 is variable and may include sinusoids, curves, arcs, and straight lines. Other factors in determining the need for an indirect path and the shape of the indirect path include thread tension, thread strength, thread diameter, stitch length, workpiece thickness, workpiece material, sewing speed, acceleration, speed of movement, and the distance between the needle point and the workpiece. Note that it is important to keep the needle thread straight.
[0034] Referring to FIG. 6, there is shown a flow chart illustrating a general method for guiding a needle thread 24 for an automated embroidery machine 1 , the needle thread 24 extending between the eye of a needle 2 a and a workpiece 22 being stitched when the needle 10 is above the workpiece 22 , to prevent breakage of the needle thread 24 by the point of the needle upon penetration of the workpiece 22 by the needle 10 during stitching, according to one embodiment of the invention. In FIG. 6, the flow chart is shown generally by numeral 600 . At step 601 , the method starts. At step 602 , a first needle penetration location and a next needle penetration location are read. At step 603 , a path for movement of the workpiece 22 between the first needle penetration location A and the next needle penetration location B is determined, wherein the path is selectively indirect. This step of determining a path can include the following: determining a probability of needle thread breakage for a direct path 460 between the first needle penetration location A and the next needle penetration location B; and, selecting an indirect path 470 if the probability is within a predetermined range. At step 604 , the workpiece 22 is moved along the path 460 , 470 from the first needle penetration location A to the next needle penetration location B, thereby guiding the needle thread 24 away from the needle point. At step 605 , the method ends.
[0035] Although the invention has been described with reference to certain specific embodiments, various modifications thereof will be apparent to those skilled in the art without departing from the spirit and scope of the invention as outlined in the claims appended hereto.
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A method for minimizing contact between a needle point and a needle thread in a computer controlled embroidery machine, to prevent breakage of the needle thread by the needle point upon penetration of a workpiece during stitching. The method includes the steps of: determining a first straight path between a current needle penetration location and a next needle penetration location; and, moving to the next needle penetration location along a second non-straight path so that the needle thread is pulled away from the needle point.
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This application claims as under 35 U.S.C. 119 of U.S. Provisional Patent Application Ser. No. 61/099,547 filed Sep. 23, 2008 and U.S. Provisional Patent Application Ser. No. 61/136,679 filed Sep. 24, 2008.
FIELD OF THE INVENTION
The present invention relates to a storage element, preferably aerodynamic, designed for a bicycle frame, and more particularly a storage element designed in conjunction with the frame so as to increase the volume for storage proximate the frame.
BACKGROUND OF THE INVENTION
The present applicant has appreciated that conventional bicycle frames and storage compartments do not utilize internal areas within the frame members for storage.
A conventional bicycle water bottle is mounted in a carrier attached to the down tube or seat tube of the frame. A conventional tool containing pouch is mounted to the frame behind the rider's seat. Typically, the water bottle or tool pouch profile extends well outside the envelope of the bicycle frame, when viewed head on, and thus adds to the frontal area of the bicycle increasing the aerodynamic drag on the bicycle. Further, the shape of the tool pouch or water bottle disturbs the air flowing across the bicycle frame members, thus further adding to the overall drag of the bicycle.
SUMMARY OF INVENTION
Accordingly, it is an object of the present invention at least to partially overcome the disadvantages of the prior art. Also, it is an object of the invention to provide an improved storage element for use with a bicycle frame to provide storage volumes internal and/or external to the frame members in order to increase storage capacity and/or reduce aerodynamic drag.
In the field of bicycle design and racing, aerodynamics plays an important role. Bicycles are now being designed to further reduce any aerodynamic drag to give the rider a further advantage over competitors or to improve their own times.
The present invention is directed to a storage element and bicycle frame that work in conjunction with each other. Bicycles made in the past have been designed in an aerodynamic fashion to reduce aerodynamic drag. As well, some storage elements, for example water bottles, have been designed to also be aerodynamic in shape. It is an object of the present invention to make both the frame and storage element complement each other so as to satisfy structural requirements of the frame yet allow for enhanced usage of volumes proximate the frame members for storage. Additionally the complementary arrangement of the frame and storage element, preferably are provided to be as aerodynamic as possible as with the storage element is designed to function as an integral aerodynamic element of the frame.
The aerodynamic shape of the bicycle frame in combination with the storage element may preferably be selected to be a shape that assists in reducing the aerodynamic drag when the bicycle moves forwardly through the air. Preferably, this may be an oval shape. Furthermore the oval shape may be a teardrop shape. A teardrop shape essentially has an enlarged rounded forward end and a reduced size at the rear end. Preferably the exterior surfaces of the tubes have a cross-section normal to the plane of the tubes which is a teardrop shape and the storage element is designed to fit within the teardrop shaped portions of the tubes, or to extend the tubes and form teardrop shapes in combination.
The storage element and frame may also be designed to facilitate the attachment of the storage element to the frame. The storage element may have concealed portions with complementary mating shapes to the concealed exterior portions of the exterior surface to a tube of the frame.
The storage element has an interior storage compartment. The interior storage compartment can be adapted to store any manner of items, including water, food, bicycle repair tools, collapsed inflatable bicycle tire replacement inner tubes, inner tube inflation devices, eyeglasses, goggles, clothing, maps, electronic equipment, computers, sensors, and other items.
The interior storage compartment can be configured to be accessible to the rider of the bicycle while the rider is riding the bicycle although it is not necessary, for example, when the compartment needs merely be accessible as when used for storing tools.
The storage element may also be or include a refillable container such as a water bottle for the storage of fluids for consumption by the rider. A drinking straw may be provided to allow the rider to drink from the storage element without removing the storage element from the frame itself.
In a further aspect, the present invention provides a bicycle frame comprising a plurality of structural elongate tubular members including a structural elongate first tubular member, the first tubular member extending about a longitudinal, the first tubular member having an elongate storage forming portion extending along the longitudinal from a first end of the storage forming portion to a second end of the storage forming portion, the first tubular member having an elongate first adjacent portion adjacent to the first end of the storage forming portion, the first adjacent portion extending along the longitudinal away from the storage forming portion from a first end of the first adjacent portion to a second end of the first adjacent portion, the storage forming portion at the first end of the storage forming portion merging into the first adjacent portion at the first end of the first adjacent portion, an exterior profile of the storage forming portion in cross section normal to the longitudinal being of reduced cross sectional area as compared to an exterior profile of first adjacent portion of the first tubular member in cross section normal to the longitudinal, a cover member removably coupled to the first tubular member over the storage forming portion and providing between the storage forming portion and the cover member a storage compartment, the combination of the storage forming portion with the cover member coupled thereto having an exterior profile in cross section normal to the longitudinal.
Preferably the exterior profile of the combination of the storage forming portion with the cover member coupled thereto smoothly merges with the exterior profile of the first adjacent portion of the first tubular member. Preferably the exterior profile of the combination of the storage forming portion with the cover member coupled thereto is a complementary shape in cross section normal to the longitudinal to a shape of the exterior profile of the first adjacent portion. Preferably the exterior profile of the combination of the storage forming portion with the cover member coupled having an average cross sectional area over its length as measured in cross section normal to the longitudinal thereto that is equal to or greater than the cross sectional area in cross section normal to the longitudinal of the exterior profile of the first adjacent portion
Preferably the exterior profile of the first adjacent portion as seen in cross-sections normal the longitudinal along the longitudinal over the first adjacent portion has an exterior shape which is substantially unchanged or gradually changes along the longitudinal over the first adjacent portion, the exterior profile of the combination of the storage forming portion with the cover member coupled thereto has an exterior shape which is substantially the same as or gradually changes from the exterior shape of the first adjacent portion.
Preferably the cover member is coupled to the storage forming portion extending longitudinally thereon and centered between two lateral sides of the first tubular member. Preferably the tubular members are engaged end to end to form a loop, and the cover member is coupled to the storage forming portion on a side of the first tubular member selected from a side directed inwardly into the loop and a side directed outwardly from the loop. The first adjacent portion the storage forming portion may appear to have a laterally extending slot there through, which slot is covered by the cover member. The exterior profile of the first adjacent portion, as seen in cross-sections normal the longitudinal, may comprise a truncated form of the exterior profile of the storage forming portion as seen in cross-sections normal the longitudinal.
The exterior profile of the first adjacent portion as seen in cross-sections normal the longitudinal along the longitudinal over the first adjacent portion has an exterior shape which is oval, and the exterior profile of the combination of the storage forming portion with the cover member coupled thereto has an exterior shape which is oval. Preferably the oval shape is a teardrop shape having an enlarged rounded forward end and a reduced size rear end.
The structural elongate tubular members preferably include a down tube, a head tube, and seat tube; wherein the first tubular member is selected from the down tube, the head tube, and the seat tube, wherein: when the first tubular member is the head tube, the cover member is rearward from the head tube with the head tube forming a front portion of an oval shape and the cover forming a rear portion of the oval shape; when the first tubular member is the seat tube, and the cover member is either is forward from the seat tube or rearward from the seat tube; and when the first tubular member is the top tube, the cover member is either upward from the top tube or downward from the top tube.
Preferably first tubular member is the down tube, the cover member bridges between the down tube and seat tube, the down tube forms the a front portion of the oval shape, the seat tube forms a rear portion of the oval shape and the cover forms a middle portion of the oval shape.
Preferably the interior storage compartment comprises a refillable container for storage of fluids.
Preferably the first tubular member having an elongate second adjacent portion adjacent to the second end of the storage forming portion, the second adjacent portion extending along the longitudinal away from the storage forming portion from a first end of the second adjacent portion to a second end of the second adjacent portion, the storage forming portion at the second end of the storage forming portion merging along the longitudinal into the second adjacent portion at the first end of the second adjacent portion, an exterior profile of the storage forming portion in cross section normal to the longitudinal being of reduced cross sectional area as compared to an exterior profile of second adjacent portion of the first tubular member in cross section normal to the longitudinal.
Preferably the exterior profile of the combination of the storage forming portion with the cover member coupled thereto smoothly merging with the exterior profile of the second adjacent portion of the first tubular member. Preferably the exterior profile of the combination of the storage forming portion with the cover member coupled thereto is a complementary shape in cross section normal to the longitudinal to a shape of the exterior profile of the second adjacent portion.
Preferably the exterior profile of the combination of the storage forming portion with the cover member coupled has an average cross sectional area over its length as measured in cross section normal to the longitudinal thereto that is equal to or greater than the cross sectional area in cross section normal to the longitudinal of the exterior profile of the second adjacent portion.
Preferably the exterior profile of the second adjacent portion as seen in cross-sections normal the longitudinal along the longitudinal over the second adjacent portion has an exterior shape which is substantially unchanged or gradually changes along the longitudinal over the second adjacent portion, the exterior profile of the combination of the storage forming portion with the cover member coupled thereto has an exterior shape which is substantially the same as or gradually changes from the exterior shape of the second adjacent portion.
When coupled to the storage forming portion, the cover member has an exposed surface that is continuous with an exposed surface of the storage forming portion. The cover member when coupled to the storage forming portion, has an exposed surface that is continuous with both an exposed surface of the storage forming portion and an exposed surface of the first adjacent portion.
In a further embodiment, the present invention provides a bicycle frame comprising a plurality of elongate tubular members engaged end to end to form forming a loop, each tubular members extending along a respective longitudinal axis, each tubular members having oppositely directed sides comprising a right hand lateral side and a left hand lateral side and oppositely directed sides comprising inwardly directed side directed inwardly into the loop and an outwardly directed side directed outwardly from the loop a slot provided laterally through a first of the tubular members from the right hand lateral side to the left hand lateral side and open to one of the inwardly directed side and inwardly directed side, a cover member removably coupled to the first tubular member over the storage forming portion to define between the storage forming portion and the cover member a storage compartment.
Further aspects of the invention will become apparent upon reading the following detailed description and drawings, which illustrate the invention and preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, which illustrate embodiments of the invention:
FIG. 1 is a side view of a bicycle frame in accordance with a first embodiment of the invention,
FIGS. 2 , 3 , 4 and 5 is each a cross section of FIG. 1 along respective section lines A-A′, B-B′, C-C′, and D-D′ in FIG. 1 ,
FIG. 6 is a cross section similar to FIG. 2 illustrating a first manner of attachment a storage element,
FIG. 7 is a cross section similar to FIG. 6 illustrating a second manner of attachment a storage element,
FIG. 8 is a side view of a bicycle frame in accordance with a second embodiment of the invention,
FIG. 9 is a schematic partial pictorial side view of a lower portion of a bicycle frame in accordance with a third embodiment of the invention showing a storage element coupled thereto,
FIG. 10 is an exploded schematic partial pictorial side view of the embodiment shown in FIG. 9 ,
FIG. 11 is a pictorial side view of the storage element shown in FIG. 9 ,
FIG. 12 is a side view of a bicycle frame in accordance with a fourth embodiment of the invention,
FIGS. 13 , 14 , and 15 are each a cross section of FIG. 12 along respective section lines E-E′, F-F′ and G-G′ in FIG. 12 ,
FIG. 16 is a perspective view of the storage element in FIGS. 12 , 13 , 14 and 15 .
FIG. 17 is a side view of a bicycle frame in accordance with a fifth embodiment of the invention,
FIG. 18 is a side view of a bicycle frame in accordance with a sixth embodiment of the invention,
FIG. 19 is a side view of a bicycle frame in accordance with a seventh embodiment of the invention,
FIG. 20 is a cross-section of FIG. 17 along section H-H′ in FIG. 18 ,
FIG. 21 is a cross-section of FIG. 18 along section I-I′ in FIG. 18 ,
FIG. 22 is a cross-section of FIG. 19 along section J-J′ in FIG. 19 , and
FIG. 23 is an schematic exploded perspective view of a section of the down tube in FIG. 1 with an elongated section removed between the jagged lines for ease of illustration.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the invention and its advantages can be understood by referring to the present drawings. Through all of the drawings the same reference numbers are used to refer to similar elements.
FIG. 1 is a side view of a bicycle frame 10 in accordance with a first embodiment of the invention. The frame 10 has a head tube 20 , a top tube 30 , a down tube 40 and a seat tube 50 . The frame, as part of a bicycle when in normal use, moves in a forward direction where the head tube 20 and down tube 40 are forward of the seat tube 50 . The top tube generally extends in forward direction. Each of the head tube 20 , top tube 30 , down tube 40 and seat tube 50 is connected end-to-end to one another and form substantially a closed main frame loop and a central cavity 15 as shown in FIG. 1 . The central cavity 15 is the area enclosed by the main frame loop 14 . Chain stays 60 extend rearwardly to join with seat stays 70 where a wheel not shown is to be journalled.
While not shown a fork is to be rotatably coupled to the head tube 20 to extend through the head tube carrying at an upper end the handlebars and at a lower end a front wheel. The head tube 20 has a top end 21 and a lower end 22 . The top tube 30 has a front end 31 and a rear end 32 . The down tube has a front end 41 and a rear end 42 . The seat tube 50 has a top end 51 and a lower end 57 .
The front end 31 of the top tube 30 is connected to the top end 21 of the head tube 20 . The front end 41 of the down tube 40 is connected to the lower end 22 of the head tube 20 . The top tube 30 and down tube 40 diverge away from each other as they extend rearwardly from the head tube 20 . The rear end 42 of the down tube 40 is coupled to the lower end 57 of the seat tube 50 . The rear end 32 of the top tube 30 is connected to the top end 51 of the seat tube 51 .
Each of the head tube 20 , top tube 30 , down tube 40 and seat tube 50 are elongate members disposed about their own longitudinal axis. The longitudinal axis of each of the head tube 20 , top tube 30 , down tube 40 and seat tube 50 lie in their own respective flat plane, which is parallel to the forward direction of travel of the bicycle frame. In a further embodiment, the longitudinal axis of each of the head tube 20 , top tube 30 , down tube 40 and seat tube 50 lie in the same flat central plane.
Each of the head tube 20 , top tube 30 , down tube 40 and seat tube 50 have a circumferential wall about their longitudinal axis, each point along the length of each of the longitudinal axis and parallel to the central plane.
Each of the head tube 20 , top tube 30 , down tube 40 and seat tube 50 are preferably generally symmetrical about the central plane. Each of these tubes preferably has an annular tubular wall with an external surface which is symmetrical about the central plane. Each of these tubes 20 , 30 , 40 and 50 has inwardly directed portions of its exterior surface facing the central cavity 15 within the mainframe loop.
FIG. 1 is a preferred first embodiment of the frame 10 schematically showing four different storage elements 102 , 103 , 104 , and 105 at four different locations on the frame. Storage element 102 is provided in a slot-like cavity 202 formed in the upper rear of the down tube 40 . As seen in FIG. 2 the down tube 40 in the cavity 202 has a cross section which is but the forward portion of a teardrop shape and the storage element 102 is provided rearwardly of the down tube 40 to complete the teardrop shape. Above and below the cavity 202 the down tube 40 has a cross section corresponding to the exterior profile of both the down tube 40 and the storage element 102 shown in FIG. 2 .
Storage element 103 is provided in a slot-like cavity 203 formed in the lower portion of the top tube 30 . As seen in FIG. 3 , the top tube 30 in the cavity 203 has a cross section which is but the upper end portion of an oval shape and the storage element 103 is provided below the top tube 30 to complete the oval shape. Forward and rearward of the cavity 203 , the top tube 30 has a cross section corresponding to the exterior profile of both the top tube 30 and the storage element 103 shown in FIG. 3 .
Seat tube 50 is shown in cross section in FIG. 4 with the forward portion of a teardrop shape having a flat rear surface with the storage element 104 provided rearwardly of the seat tube 50 to complete the teardrop shape. Below the storage element 104 the seat tube 50 has a teardrop shape proportional to but tapered down, that is reduced in front to rear dimension from the exterior profile of both the seat tube 50 and the storage element 104 shown in FIG. 4 .
Storage element 105 is provided in a slot-like cavity 205 formed in the rear of the head tube 20 . As seen in FIG. 5 the head tube 20 in the cavity 205 has a cross section which is but the forward portion of a teardrop shape and the storage element 105 is provided rearwardly of the head tube 20 to complete the teardrop shape.
The storage elements and frame tubes shown in FIGS. 1 to 5 , as well as FIGS. 7 to 8 and 12 to 15 are schematically shown for simplicity of illustration principally by their own exterior surfaces indicating that the tubes are hollow members and that the storage elements provide internal storage compartments or cavities either alone or in combination with external surfaces of the tubes. As seen in FIGS. 2 , 3 , 4 and 6 , each storage element is effectively a C-shaped cover, which encloses a storage volume closed on one side by an associated tube. As seen in FIGS. 5 and 7 , the storage element is a hollow tube.
FIG. 6 schematically illustrates the storage element 102 coupled to the down tube 40 by a hinge 302 on one side to be movable from a closed position shown to an open position and with a latch or releasable closure element 14 on the other side to secure the storage element 102 in the closed position. In this embodiment the storage element may be considered a hollow cover defining a cavity under the cover rearward of the rear surface of the down tube 40 .
FIG. 7 schematically illustrates the storage element 102 coupled to the down tube 40 by a friction fit barbed fastener 304 to extend into an opening into the wall of the down tube 40 . In this embodiment the storage element may be considered a hollow tubular member with an interior cavity and some access to the cavity which may be a separate door or cover carried for example on the storage element 102 but not shown.
FIG. 8 is a side view of a bicycle frame in accordance with a second embodiment of the invention and schematically showing three different storage elements 108 , 208 , and 308 each located at a junction of two or more of the tubes of the frame 10 and the storage element at each junction may be have as part of its interior cavity volumes where the tubes are reduced in cross section as compared to cross sections of the same tubes longitudinally spaced from the storage element.
FIG. 9 illustrates a schematic partial pictorial side view of a lower portion of a bicycle frame in accordance with a third embodiment of the invention, showing the lower portions of the down tube 40 and the seat tube 50 as well as a forward portion of the chain stays 60 . A storage element 109 is shown at the junction of the down tube 40 and the seat tube 50 as a preferred embodiment of a storage element more generically shown as 108 in FIG. 8 .
The storage element 109 in FIGS. 9 to 11 comprises a hollow shroud or cover which is adapted to enclose the junction of the down tube 40 and the seat tube 50 . Support plugs 120 are mounted to interior surfaces of the seat tube and down tube by screws 122 and the storage element 109 is removably mounted to these plugs 120 by attachment screws 124 extending laterally through edge portions of the storage element 109 into ends of the plugs 120 .
The down tube 40 has a slot-like cavity 102 formed in its upper rear proximate its juncture with the seat tube 50 . The down tube 40 above the slot-like cavity 102 has in cross section a teardrop shape directed forwardly. In cross section through the slot-like cavity 102 the down tube 40 approximately has a cross section which is but the forward portion of a teardrop shape. The storage element 109 has an upper most portion 126 which is a complementary rear portion to fill in the upper portion of the slot-like cavity 102 and with juxtapositioned portions of the down tube 40 providing in combination an external teardrop shape. Below the upper most portion 126 the storage element 109 is effectively a U-shaped rear portion 128 with a relatively flat top wall 130 and two downwardly extending side walls 132 and 134 , The periphery of the side walls 132 and 134 are adapted to mate in a flush relation with side wall portions of the seat tube and down tube in a flush arrangement as seen in FIG. 9 . A storage compartment is provided internally within the storage element 109 and between the storage element and the seat tube and the down tube. The storage element 109 may be a structural member increasing the strength and integrity of the frame 10 , or it may comprise merely a decorative cover.
FIG. 12 is a side view of a bicycle frame in accordance with a fourth embodiment of the invention and showing a storage element 112 formed internally within the frame 10 open through the top of the top tube 30 and extending down through the top tube 30 , down through a rear portion of the head tube 20 rearwardly of the journal opening 140 to receive the steering tube (not shown), and down into the down tube 40 , ending internally in the upper rear of down tube 40 at a blind lower end 142 . FIG. 16 shows the storage element 112 as a hollow upwardly directed cup, suitable to receive articles in its upwardly opening end, as for example adapted to receive a water bottle. The cup could have a closable lid accessible from above the top tube 20 .
As seen in FIG. 13 , which is a cross-section along E-E′ in FIG. 12 , the head tube 20 has an exterior tear drop shape. The volume is located at the rear portion of the head tube and is adapted to accept the storage element 114 .
As seen in FIG. 14 , which is a cross-section along F-F′ in FIG. 12 , the storage element 114 is located within the top tube 30 .
As seen in FIG. 15 , which is a cross-section along G-G′ in FIG. 12 , the storage element extends through the volume in the down tube 40 .
FIG. 16 is a perspective view of the storage element in FIGS. 12 , 13 , 14 and 15 .
FIG. 17 is a side view of a bicycle frame in accordance with a fifth embodiment of the invention and showing a storage element 116 formed in the upper portion of the top tube 30 .
Storage element 116 is provided in a slot-like cavity 206 formed in the upper portion of the top tube 30 . As seen in FIG. 20 , the top tube 30 has a cross-section which is the lower end portion of an oval shape. Forward and rearward of the cavity 206 , the top tube has an oval shape in cross-section corresponding to the exterior profile of both the top tube 30 and storage element 116 shown in FIG. 20 .
FIG. 18 is a side view of a bicycle frame in accordance with a sixth embodiment of the invention and showing a storage element 117 attached on the upper portion of the top tube 30 . As seen in FIG. 21 , the top tube 30 has a cross-section which is roughly rectangular with curved corners. The storage element 117 has a bottom portion 119 which corresponds to the upper portion 120 of the top tube 30 . The top tube 30 and the storage element 117 , together form an oval shape.
FIG. 19 is a side view of a bicycle frame in accordance with a seventh embodiment of the invention and showing a storage element 118 attached to the upper portion of the top tube 30 . As shown in FIG. 19 , the storage element 118 is substantially placed at the front end 31 of the top tube 30 . The storage element 118 has in cross-section indicated as J-J′ in FIG. 22 the same cross-section as seen in FIG. 21 , that is with the storage element 118 is designed to complement top tube 30 to form a substantially oval shape.
The storage elements may be secured to the frames permanently or for removal. For example, any one or more of the storage elements may be held in place on the frame 10 by a number of non-permanent fastening methods, for example, with complementary mating shapes on the storage element and on the frame 10 .
The disclosure can also be understood to teach that at least one of the head tube 20 , down tube 40 , seat tube 50 and top tube 30 of a bicycle frame 10 has a portion with a reduced cross-section rather than being referred to as a slot-like cavity 102 , 202 , 203 , 205 and 206 .
As shown in FIGS. 1 and 23 , bicycle frame 10 includes a down tube 40 that is an elongate tubular member. The down tube 40 extends about a longitudinal 401 . The down tube 40 has an elongate storage forming portion 403 extending along the longitudinal 401 from a first end 404 of the storage forming portion to a second end 405 of the storage forming portion.
The down tube 40 also has an elongate first adjacent portion 406 adjacent to the first end 404 of the storage forming portion. The first adjacent portion 406 extends along the longitudinal 401 away from the storage forming portion 403 from a first end 407 of the first adjacent portion to a second end 408 of the first adjacent portion.
The storage forming portion 403 at the first end 404 of the storage forming portion merges into the first adjacent portion 406 at the first end 407 of the first adjacent portion.
As shown in FIG. 23 , an exterior profile of the storage forming portion 403 in cross section normal to the longitudinal has a reduced cross sectional area as compared to an exterior profile of first adjacent portion 406 of the down tube 10 in cross section normal to the longitudinal.
A cover member 402 is removably coupled to the down tube 10 over the storage forming portion 403 . A storage compartment is created between the storage forming portion 403 and the cover member 402 .
When the storage forming portion 403 is coupled with the cover member 402 , the two have an exterior profile in cross section normal to the longitudinal.
As shown in FIG. 1 , when the cover member 402 is coupled to the down tube 40 at the storage forming portion 403 , the exterior profile of the combination of the storage forming portion 403 with the cover member 402 smoothly merges with the exterior profile of the first adjacent portion 406 of the down tube 40 .
As shown in FIG. 1 , the exterior profile of the combination of the storage forming portion 403 with the cover member 402 when coupled is a complementary shape in cross section normal to the longitudinal to a shape of the exterior profile of the first adjacent portion 406 .
As shown in FIGS. 1 , 18 and 23 , the exterior profile of the combination of the storage forming portion 403 with the cover member 402 coupled has an average cross sectional area over its length as measured in cross section normal to the longitudinal that is equal to ( FIG. 1 ) or greater than ( FIG. 18 ) the cross sectional area in cross section normal to the longitudinal of the exterior profile of the first adjacent portion 406 .
As shown in FIGS. 1 and 23 , the exterior profile of the first adjacent portion 406 as seen in cross-sections normal the longitudinal along the longitudinal over the first adjacent portion 406 has an exterior shape which is substantially unchanged or gradually changes along the longitudinal over the first adjacent portion 406 .
As shown in FIGS. 1 , 9 and 23 , the exterior profile of the combination of the storage forming portion 403 and the cover member 402 when coupled has an exterior shape which is substantially the same as or gradually changes from the exterior shape of the first adjacent portion 406 .
As shown in FIGS. 1 and 23 , the cover member 402 is coupled to the storage forming portion 403 and extends longitudinally and is centered between two lateral sides of the down tube 40 .
As shown in FIGS. 1 and 17 , the down tube 40 , seat tube 50 , top tube 30 and head tube 20 are engaged end to end to form a loop. The cover member 402 is coupled to the storage forming portion 403 on a side of the down tube 40 selected from a side directed inwardly into the loop ( FIG. 1 ) and a side directed outwardly from the loop ( FIG. 17 ).
As shown in FIG. 23 , the storage forming portion 403 , when compared to the first adjacent portion 406 , appears to have a laterally extending slot 410 through the storage forming portion 403 , which slot 410 is covered by the cover member 402 .
As shown in FIGS. 9 and 23 , the exterior profile of the down tube 40 as seen in cross-sections normal the longitudinal comprises a truncated form of the exterior profile of the storage forming portion 403 as seen in cross-sections normal the longitudinal.
As shown in FIG. 23 , the exterior profile of the down tube 40 as seen in cross-sections normal the longitudinal along the longitudinal 401 over the first adjacent portion 406 has an exterior shape which is oval.
As shown in FIGS. 2 and 23 , the exterior profile of the combination of the storage forming portion 403 when the cover member 402 is coupled has an exterior shape which is oval.
As shown in FIGS. 2 and 23 , the oval shape is a teardrop shape having an enlarged rounded forward end and a reduced size rear end.
As shown in FIGS. 8 , 9 and 10 , the cover member 440 may bridge between the down tube 40 and seat tube 50 with the down tube 40 forming a front portion of the oval shape, the seat tube 50 forming a rear portion of the oval shape and the cover forming a middle portion of the oval shape.
The interior storage compartment may comprise a refillable container for storage of fluids.
As shown in FIGS. 1 and 23 , the down tube 40 has an elongate second adjacent portion 450 adjacent to the second end 405 of the storage forming portion 403 . The second adjacent portion 450 has a first end 451 of the second adjacent portion and a second end 452 of the second adjacent portion. The second adjacent portion 450 extends along the longitudinal 401 away from the storage forming portion 403 from the first end 451 of the second adjacent portion to the second end 452 of the second adjacent portion.
The storage forming portion 403 at the second end 405 of the storage forming portion merges along the longitudinal 401 into the second adjacent portion 450 at the first end 451 of the second adjacent portion.
An exterior profile of the storage forming portion 403 in cross section normal to the longitudinal is of reduced cross sectional area as compared to an exterior profile of second adjacent portion 450 of the down tube 40 in cross section normal to the longitudinal.
As shown in FIGS. 1 and 23 , the exterior profile of the combination of the storage forming portion 403 and the cover member 402 when coupled smoothly merges with the exterior profile of the second adjacent portion 450 of the down tube 40 .
As shown in FIGS. 1 and 23 , the exterior profile of the combination of the storage forming portion 403 and the cover member 402 when coupled is a complementary shape in cross section normal to the longitudinal to a shape of the exterior profile of the second adjacent portion 450 .
As shown in FIGS. 1 and 23 , the exterior profile of the combination of the storage forming portion 403 and the cover member 402 when coupled has an average cross sectional area over its length as measured in cross section normal to the longitudinal that is equal to or greater than the cross sectional area in cross section normal to the longitudinal of the exterior profile of the second adjacent portion 450 .
As shown in FIGS. 1 and 23 , the exterior profile of the second adjacent portion 450 as seen in cross-sections normal the longitudinal along the longitudinal 401 over the second adjacent portion 450 has an exterior shape which is substantially unchanged or gradually changes along the longitudinal 401 over the second adjacent portion 450 .
The exterior profile of the combination of the storage forming portion 403 and the cover member 402 when coupled has an exterior shape that is substantially the same as or gradually changes from the exterior shape of the second adjacent portion 450 .
As shown in FIGS. 1 and 23 , when the cover member 402 is coupled to the storage forming portion 403 , the cover member 402 has an exposed surface that is continuous with an exposed surface of the storage forming portion 402 .
As shown in FIGS. 1 and 23 , when the cover member 402 is coupled to the storage forming portion 403 , the cover member 402 has an exposed surface that is continuous with both an exposed surface of the storage forming portion 403 and an exposed surface of the first adjacent portion 406 .
As shown in FIG. 1 , the bicycle frame includes a plurality of elongate tubular members, including the head tube 20 , down tube 40 , seat tube 50 and top tube 30 , engaged end to end to form forming a loop.
As shown in FIGS. 1 and 5 , the structural elongate tubular members of the bicycle frame 10 include the down tube 40 , the top tube 30 , the head tube 20 , and the seat tube 50 . It is understood that the head tube 20 may have an elongate storage portion 412 with a first end 413 and second end 414 as described above for the down tube 40 . When the head tube 20 has the elongate storage portion 412 , the cover member 415 is rearward from the head tube 20 with the head tube 20 forming a front portion of an oval shape and the cover forming a rear portion of the oval shape.
The cover member 415 may bridge between the down tube 40 and top tube 30 , with the head tube 20 and down tube 40 forming the front portion of the oval shape and the cover 415 forming the rear portion of the oval shape.
As shown is FIGS. 1 and 4 , it is understood that the seat tube 50 may have an elongate storage portion 421 with a first end 422 and second end 423 as described above for the down tube 40 . When the first tubular member is the seat tube 50 , the cover member 424 is either is forward from the seat tube 50 or rearward from the seat tube 50 .
As shown in FIGS. 1 , 3 , 17 and 20 , it is understood that the top tube 30 may have an elongate storage portion 431 with a first end 432 and second end 433 as described above for the down tube 40 . When the first tubular member is the top tube 30 , the cover member 434 is either upward from the top tube 30 ( FIG. 1 ) or downward from the top tube 30 ( FIG. 17 ).
The embodiment expressed above is described with respect to a down tube 40 having a storage forming portion 403 , a first adjacent side 406 with a first end 407 and a second end 408 and a second adjacent side 450 with a first end 451 and a second end 452 . However, each of the seat tube 50 , top tube 30 and head tube 20 can each have a storage forming portion and a first adjacent side with a first end and a second end. Each of the seat tube 50 , top tube 30 and head tube 20 may also have a second adjacent side with a first end and a second end.
Each of the head tube 20 , down tube 40 , seat tube 50 and top tube 30 extends along a respective longitudinal axis and has oppositely directed sides comprising a right hand lateral side and a left hand lateral side. The head tube 20 , down tube 40 , seat tube 50 and top tube 30 also have oppositely directed sides comprising inwardly directed side directed inwardly into the loop and an outwardly directed side directed outwardly from the loop.
A slot ( 102 , 202 , 203 , 205 , 206 ) is provided laterally through one of the head tube 20 , down tube 40 , seat tube 50 and top tube 30 from the right hand lateral side to the left hand lateral side and open to one of the inwardly directed side and inwardly directed side. A cover member 415 , 402 , 424 , 434 is removably coupled to the one of the head tube, down tube, seat tube and top tube over the storage forming portion 412 , 403 , 421 , 431 to define between the storage forming portion 412 , 403 , 421 , 431 and the cover member 415 , 402 , 424 , 434 a storage compartment.
While the storage forming portion 403 in FIG. 23 is shown as having a solid wall, it is understood that in particular embodiments a solid wall is not necessary. Furthermore, while the first end of the first adjacent portion in FIG. 23 is shown as being open to the interior of the down tube 40 , it is understood that the first end 407 of the first adjacent portion and the first end 451 of the second adjacent portion may be open to the interior of the down tube 40 or may be a solid wall closed to the interior of the down tube 40 .
While the invention will be described in conjunction with the illustrated embodiments, it is understood that it is not intended to limit the invention to such embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention.
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The present invention relates to a storage element, preferably aerodynamic, designed for a bicycle frame, and more particularly a storage element designed in conjunction with the frame so as to increase the volume for storage proximate the frame.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an automatic ice maker for use in a refrigerator, and more particularly, to an ice maker-driving device for a refrigerator which generally includes an ice quantity-checking part, an ice-separating part, a test switch, a control circuit for operating them, a driving shaft having a power transmission unit, all kinds of reduction gears and a worm gear, and the like.
[0003] 2. Background of the Related Art
[0004] As one example of the prior art, Korean Patent No. 1992-1971 (entitled ‘refrigerator attached with automatic ice maker’ as filed on Mar. 7, 1989) discloses a refrigerator with an automatic ice maker which removes ice cubes from an ice-making tray when a temperature on the ice-making tray detected by a temperature sensor is below a predetermined set icing completion temperature and feeds water to the ice-making tray again to perform an ice-making operation, the refrigerator including: a determining unit adapted to determine whether the fed water is normal or not when the temperature of the ice-making tray detected by the temperature sensor after feeding the water to the ice-making tray is below a predetermined temperature; and an alarming unit adapted to perform an alarming operation based on the determination result of the determining unit. In the conventional refrigerator with the automatic ice maker, the alarming function is additionally provided to warn that the ice-making tray is operated without the feeding of the water thereto when the water in a water-feeding tank separately mounted to the automatic ice maker is in short supply.
[0005] As another example of the prior art, Korean Utility Model Registration No. 1993-4478 (entitled ‘refrigerator attached with automatic ice maker’ as filed on Mar. 11, 1989) discloses a refrigerator with an automatic ice maker wherein water is fed to an ice-making tray and frozen thereinto to make ice cubes, the ice cubes are removed from the ice-making tray and stored in an ice-storing container, and then, the quantity of stored ice is checked by a lever that is changed in position in accordance with the quantity of ice stored in the ice-storing container, such that when the quantity of ice stored in the ice-storing container is below a predetermined value, ice-making and ice-storing operations are repeatedly performed, and thus, if the quantity of ice stored in the ice-storing container is over the predetermined value, a stored ice quantity checking switch adapted to operated by means of the lever is operated to stop the ice-making operation. In the above-mentioned conventional practice, when it is checked that the quantity of stored ice is over the predetermined value by means of the ice quantity-checking lever adapted to check the quantity of ice stored in the ice-storing container, the ice-making operation is controlled by the switch (sensor).
[0006] As yet another example of the prior art, Korean Patent No. 228819 (entitled ‘automatic ice maker’ as filed on Nov. 29, 1994) discloses an automatic ice maker which has an ice-making tray rotatably connected to one end of an operating gear moved by a motor, such that water is automatically fed to the ice-making tray and the ice-making tray is rotated by a predetermined angle under the control of a controller adapted to sense the completion of the ice-making operation so as to separate the ice cubes from the ice-making tray, thereby automatically completing the ice-making operation. The above-mentioned automatic ice maker includes the motor, the operating gear, the ice-making tray, and the controller, so as to rotate the ice-making tray.
[0007] As still another example of the prior art, Korean Patent No. 182735 (entitled ‘power control method for automatic ice maker’ as filed on Nov. 15, 1996) discloses a power control method for an automatic ice maker which includes: the steps of placing an ice-making tray to its original position by means of a driving motor so as to supply water to the ice-making tray; feeding water to the ice-making tray so as to make ice cubes thereinto; separating the ice cubes from the ice-making tray if the ice-making operation is completed; and if it is determined that the driving motor is overloaded, reversely rotating the driving motor so as to release the overloaded state of the driving motor.
[0008] In the above-mentioned prior art, further, the overloading of the driving motor is made when the ice-making tray escapes from its original position, the overloading of the driving motor is determined when the voltage loaded to the driving motor is measured and higher than a reference voltage of the driving motor, and the reverse rotation of the driving motor in the revere-rotating step is conducted so as to prevent the ice-making tray from escaping from its original position. According to the features of the above-mentioned prior art, the power control method for the automatic ice maker includes the step of reversely rotating the driving motor so as to release the overloading state of the driving motor.
[0009] As further another example of the prior art, Korean Patent No. 182736 (entitled ‘automatic ice maker for refrigerator’ as filed on Nov. 19, 1996) discloses an automatic ice maker for a refrigerator wherein if a maximum rotating angle exceeds by the malfunction of a sensing switch (sensor) upon the rotation of an ice-making tray by a motor, the ice-making tray, a cam gear and various parts are damaged, which is caused in the same manner even when the reverse rotation of the ice-making tray to return the ice-making tray to its original position after ice cubes are separated from the ice-making tray, the automatic ice maker for the refrigerator including: a first stopper mounted at a position higher than a position where the cam gear stops at a maximum rotating position; and a second stopper mounted at a position higher than a position where the cam gear stops at a horizontal position. In this prior art, that is, the automatic ice maker only includes the first and second stoppers.
[0010] As still yet another example of the prior art, Korean Patent No. 422969 (entitled ‘driving device for automatic ice maker’ as filed on Jun. 16, 2001) discloses a driving device for an automatic ice maker that changes the coupling relation between a worm gear and a driving motor and obtains the simple cooperating relation among the parts thereof, wherein an ice-making tray is rotated by the operation of the driving motor, the ice cubes are separated from the ice-making tray, and the ice-making tray is reversely rotated to return to its ice-making position. In the above-mentioned prior art, the rotation and the reverse rotation of the ice-making tray by means of the driving motor are well known in this field.
[0011] As described above, the shape, structure and practical functions of the automatic ice maker for a refrigerator are well known in this field, and therefore, the present invention relates to an improved automatic ice maker for a refrigerator.
[0012] Also, since water is changed into ice cubes during the ice-making process, the volume of water is increased such that the water having a density of 1.00 g/cm3 is changed into an ice cube having a density of 0.9168 g/cm3, and if 10 ml volume of water of 0° C. in a space where a piece of ice cube in the ice-making container is made is frozen, the volume of water becomes about 11 ml such that as the volume is expanded to cause the pressure in the ice-making container to be increased, thereby making it difficult to separate the ice cubes tightly attached on the ice-making container only by means of the rotation of 180° of the ice-making container. In order to solve this problem, the ice-making container is constructed to be twisted at one side thereof when it is rotated over 180° in the horizontal state thereof, which causes one-sided driving to be repeatedly conducted to generate the stress only on one side of gears, thereby shortening the lifespan of the parts and failing to easily separate the ice cubes from the ice-making container.
SUMMARY OF THE INVENTION
[0013] Accordingly, the present invention has been made in view of the above-mentioned problems occurring in the prior art, and it is an object of the present invention to provide an improved ice maker-driving device for a refrigerator and a method for operating the same wherein the structures and functions of conventional automatic ice makers are modified to provide simple and efficient driving and the organic coupling relation among parts is improved in such a manner that the parts are rigidly cooperated with one another, thereby achieving the reduction of error rate and the strong durability against internal or external vibration and impact.
[0014] It is another object of the present invention to provide an ice maker-driving device for a refrigerator and a method for operating the same wherein in order to solve the problem that when the ice cubes in an ice-making container are separated by the rotation of an ice-separating lever by means of a motor after the quantity of ice stored in an ice-storing container is checked in a low level by an ice quantity-checking lever, the ice-making container connected to the ice-separating lever and rotated by initial circuit set is reversely rotated before forward rotation and has a protruded coupling part having a predetermined angle formed on the other side thereof, without any cooperation with the ice-separating lever, so as to be coupled with a case-fixing part, thereby allowing the ice-making container to be twistedly rotated at one side thereof according to the reverse rotation of the ice-separating lever, such that the separation of ice cubes is conducted and also the stress and tense state of the parts caused by their freezing are removed to prevent their malfunction, thereby smoothly achieving the ice-separating and storing operations.
[0015] To accomplish the above objects, according to the present invention, there is provided an ice maker-driving device for a refrigerator which is adapted to change water in an ice-making container into ice cubes by the driving of an ice quantity-checking lever and an ice-separating lever according to the transmission of power from a motor by using a plurality of worm and reduction gears mounted in a body thereof, adapted to check the quantity of ice stored in an ice-storing container by means of the ice quantity-checking lever and an ice quantity-checking sensor to rotate the ice-making container in which the ice cubes are filled by 180° by means of the ice-separating lever if the quantity of ice stored in the ice-storing container is in short supply and to fill the ice cubes in the ice-storing container, and adapted to return the ice quantity-checking lever to its original position, stop the movement of the ice-separating lever and return to a stand-by state, if the quantity of ice stored in the ice-storing container is in sufficient supply, the ice maker-driving device including: a body having an upper case and a lower case; a motor mounted in the lower case and adapted to be driven by the supply of power thereto; a worm gear compressedly fastened to the motor and rotated by the rotation of the motor; a first wheel gear adapted to change the rotating direction of the horizontal shaft of the worm gear; a second wheel gear adapted to be rotated by means of a first reduction gear mounted on the flat surface of the first wheel gear; a third wheel gear adapted to be rotated by means of a second reduction gear mounted on the flat surface of the second wheel gear; an ice-separating lever formed on the upper portion of the third wheel gear; cam section bent parts and a fixing shaft-coupling part formed on the underside of the third wheel gear; a stopper adapted to be fastened to the fixing shaft-coupling part; a stopper-locking projection formed on the fixing shaft-coupling part so as to restrict the operation of a rotary radius control projection formed on the stopper; a fixing shaft formed on the lower case and adapted to be supported by means of the fixing shaft-coupling part; a spin control protrusion formed on the fixing shaft and a spin control groove formed on the stopper in such a manner as to be coupled between the fixing shaft and the fixing shaft-coupling part and to control the operation of a spin lever; a fixing projection formed on the spin lever so as to fix the spin lever by means of a lever-fixing protrusion formed on the stopper; a cam driving protrusion adapted to be moved along the cam section bent parts formed on the underside of the third wheel gear so as to perform ice quantity checking and signal process; a cam control protrusion adapted to be moved along the cam section bent parts together with the ice-separating lever formed on the third wheel gear; a magnet adapted to transmit a signal to a hall sensor so as to perform the signal process in an organic relation with the movement of the cam control protrusion; a receiving and fixing clip formed on a check lever so as to house the magnet therein; a check lever spring adapted to apply predetermined elasticity to the check lever so as to prevent the malfunctions of parts and ensure the positioning of the check lever; a first spring-fastening part adapted to fix the check lever spring thereto; a first spring-fixing part formed on the lower case so as to fix the check lever spring thereto; a printed circuit board with the hall sensor adapted to receive the signal from the magnetic force of the magnet; the hall sensor mounted on the printed circuit board; a sensor cover adapted to protect the hall sensor; a check box mounted on the printed circuit board so as to test an initial operation of the body; an interference-preventing groove formed on the spin lever so as to avoid the superposing of the spin lever on the check lever during the movement of the check lever and to perform the signal process on the signal received from the magnet, thereby performing effective space utilization of the body; a spin lever spring adapted to apply predetermined elasticity so as to ensure the positioning of the spin lever; a second spring-fastening part adapted to fix the spin lever spring thereto; a second spring-fixing part formed on the lower case so as to fix the spin lever spring thereto; a test button formed on the upper case and adapted to activate the check box so as to perform an initial test for the driving of the body; and an ice quantity-checking lever adapted to be coupled to a fixing part of the spin lever by means of the test button so as to perform initial ice quantity checking.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The above and other objects, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments of the invention in conjunction with the accompanying drawings, in which:
[0017] FIG. 1 is an exploded perspective view showing the whole structure of an ice maker-driving device according to the present invention;
[0018] FIG. 2 a is a back view showing the position of an ice quantity-checking lever and the state of a stopper upon a full ice level in the ice maker-driving device according to the present invention;
[0019] FIG. 2 b is a back view showing the position of an ice quantity-checking lever and the state of a stopper upon a low ice level in the ice maker-driving device according to the present invention
[0020] FIG. 3 a is a perspective view showing the use state of a spin lever when a sensor is turned at an on state in the ice maker-driving device according to the present invention.
[0021] FIG. 3 b is a perspective view showing the use state of the spin lever when the sensor is at an off state in the ice maker-driving device according to the present invention;
[0022] FIG. 4 a is a perspective and partly cut plan view showing the initial driving states of a check lever along cam section bent parts in the ice maker-driving device according to the present invention;
[0023] FIG. 4 b is a perspective and partly cut plan view showing the driving states of the reverse rotation of the check lever along the cam section bent parts in the ice maker-driving device according to the present invention;
[0024] FIG. 4 c is a perspective and partly cut plan view showing the driving states of the check lever along the cam section bent parts upon the full ice level in the ice maker-driving device according to the present invention;
[0025] FIG. 4 d is a perspective and partly cut plan view showing the driving states of the check lever along the cam section bent parts upon the low ice level in the ice maker-driving device according to the present invention;
[0026] FIG. 4 e is a perspective and partly cut plan view showing the final driving states of the check lever along the cam section bent parts in the ice maker-driving device according to the present invention;
[0027] FIG. 5 is a view showing the reverse twisting state upon initial driving of the ice maker-driving device according to the present invention;
[0028] FIG. 6 is a perspective view showing the cam structure formed on the underside of a third wheel gear and the operating state thereof in the ice maker-driving device according to the present invention;
[0029] FIG. 7 is a perspective view showing the whole assembling state of the ice maker-driving device according to the present invention;
[0030] FIG. 8 a is a flow chart showing the initial setting procedure of the ice maker-driving device according to the present invention; and
[0031] FIG. 8 b is a flow chart showing the basic operation cycle of the ice maker-driving device according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0032] Hereinafter, an explanation on an ice maker-driving device according to a preferred embodiment of the present invention will be given with reference to the attached drawings.
[0033] FIG. 1 is an exploded perspective view showing the whole structure of an ice maker-driving device according to the present invention. As shown in FIG. 1 , the ice maker-driving device according to the present invention includes: a body 1 having an upper case 2 and a lower case 3 ; a motor 13 mounted in the lower case 3 and adapted to be driven by the supply of power thereto; a worm gear 8 compressedly fastened to the motor 13 and rotated by the rotation of the motor 13 ; a first wheel gear 9 adapted to change the rotating direction of the horizontal shaft of the worm gear 8 ; a second wheel gear 10 adapted to be rotated by means of a first reduction gear 9 ′ mounted on the flat surface of the first wheel gear 9 ; a third wheel gear 11 adapted to be rotated by means of a second reduction gear 10 ′ mounted on the flat surface of the second wheel gear 10 ; an ice-separating lever 5 formed on the upper portion of the third wheel gear 11 ; cam section bent parts 32 and a fixing shaft-coupling part 34 formed on the underside of the third wheel gear 11 ; a stopper 12 adapted to be fastened to the fixing shaft-coupling part 34 ; a stopper-locking projection 12 ′ formed on the fixing shaft-coupling part 34 so as to restrict the operation of a rotary radius control projection 23 formed on the stopper 12 ; a fixing shaft 18 formed on the lower case 3 and adapted to be supported by means of the fixing shaft-coupling part 34 ; a spin control protrusion 19 formed on the fixing shaft 18 and a spin control groove 31 formed on the stopper 12 in such a manner as to be coupled between the fixing shaft 18 and the fixing shaft-coupling part 34 and to control the operation of a spin lever 7 ; a spin control protrusion 19 and a spin control groove 31 formed on the stopper 12 coupled between the fixing shaft 18 and the fixing shaft-coupling part 34 and operated by the friction force against the fixing shaft-coupling part 34 and adapted to control the operation of a spin lever 7 ; a fixing projection 33 formed on the spin lever 7 so as to fix the spin lever 7 by means of a lever-fixing protrusion 22 formed on the stopper 1 ; a cam driving protrusion 29 adapted to be moved along the cam section bent parts 32 formed on the underside of the third wheel gear 11 so as to perform ice quantity checking and signal process; a cam control protrusion 28 adapted to be moved along the cam section bent parts 32 together with the ice-separating lever 5 formed on the third wheel gear 11 ; a magnet 27 adapted to transmit a signal to a hall sensor 39 so as to perform the signal process in an organic relation with the movement of the cam control protrusion 28 ; a receiving and fixing clip 40 formed on a check lever 6 so as to house the magnet 27 therein; a check lever spring 21 adapted to apply predetermined elasticity to the check lever 6 so as to prevent the malfunctions of parts and ensure the positioning of the check lever 6 ; a first spring-fastening part 25 adapted to fix the check lever spring 21 thereto; a first spring-fixing part 37 formed on the lower case 3 so as to fix the check lever spring 21 thereto; a printed circuit board 14 with the hall sensor 39 adapted to receive the signal from the magnetic force of the magnet 27 ; the hall sensor 39 mounted on the printed circuit board 14 ; a sensor cover 16 adapted to protect the hall sensor 39 ; a check box 17 mounted on the printed circuit board 14 so as to test an initial operation of the body 1 ; an interference-preventing groove 30 formed on the spin lever 7 so as to avoid the superposing of the spin lever 7 on the check lever 6 during the movement of the check lever 6 and to perform the signal process on the signal received from the magnet 27 , thereby performing effective space utilization of the body 1 ; a spin lever spring 20 adapted to apply predetermined elasticity so as to ensure the positioning of the spin lever 7 ; a second spring-fastening part 26 adapted to fix the spin lever spring 29 thereto; a second spring-fixing part 38 formed on the lower case 3 so as to fix the check lever spring 21 thereto; a spring escape-preventing projection 44 formed on the second spring-fastening part 26 of the spin lever 7 so as to prevent the spin lever spring 20 coupled to the second spring-fastening part 26 from being separated by the rotation of the spin lever 7 ; a test button 24 formed on the upper case 2 and adapted to activate the check box 17 so as to perform an initial test for the driving of the body 1 ; and an ice quantity-checking lever 4 adapted to be coupled to a fixing part 35 of the spin lever 7 by means of the test button 24 so as to perform initial ice quantity checking.
[0034] FIGS. 2 a to 3 b are perspective views showing the use states of the stopper 12 according to the position of the ice quantity-checking lever 4 and the operation of the hall sensor 39 and the position of the spin lever 7 in the ice maker-driving device according to the present invention. The spin lever 7 is operated to allow the magnet 27 of the check lever 6 to be near the hall sensor 39 by means of the elasticity of the spin lever spring 20 , and in this case, the spin lever 7 is fixed by means of the lever-fixing protrusion 22 of the stopper 12 and is restricted in its rotation. As shown in the figures, however, if the quantity of ice stored in the ice-storing container is sufficient in use (in a full level), the ice quantity-checking lever 4 is locked to the stored ice cubes and does not fall to a predetermined depth, and the spin lever 7 connected to the ice quantity-checking lever 4 also stops such that the magnet 27 does not approach to the hall sensor 39 , thereby making the signal kept in a high (on) state.
[0035] However, if the quantity of ice stored in the ice-storing container is in short supply in use (in a low level), the ice quantity-checking lever 4 falls to a predetermined depth in the ice-storing container, and the spin lever 7 connected to the ice quantity-checking lever 4 is rotated with respect to the fixing shaft 18 by means of the friction force of the stopper 12 against the third wheel gear 11 .
[0036] FIGS. 4 a to 4 e are perspective and partly cut plan views showing the state variations of the cam control protrusion 28 of the check lever 6 and the cam driving protrusion 29 of the spin lever 7 along the cam section bent parts 32 in case of the reverse rotation of the check lever 6 in the initial state of the body 1 , in case of the full ice level, in case of the low ice level, and in case of the final driving state, wherein the surfaces of the cam section bent parts 32 formed on the underside of the third wheel gear 11 are broken so as to show the above-mentioned state variations. The check lever 6 which is separately driven in the conventional practice is configured to a unitary body such that upon the rotation of the ice-separating lever 5 , the cam control protrusion 28 of the spin lever 7 is varied in the position and is driven along the cam section bent parts 32 in an organic relation with the check lever 6 moved along or fixed to the cam section bent parts 32 formed on the underside of the third wheel gear 11 .
[0037] Referring to FIG. 1 and FIGS. 4 a to 4 e, so as to fixedly couple the worm gear 8 to the motor 13 , the worm gear 8 has a fixing hole 48 formed on the distal end thereof, and the fixing hole 48 is of a generally square shape. Thus, a fixing member 49 that is fitted to the rotary shaft of the motor 13 is fixedly inserted into the fixing hole 48 , thereby transmitting the rotary force of the motor 13 to the worm gear 8 .
[0038] Preferably, also, the fixing member 49 is rounded along the front periphery thereof so as to be easily inserted into the fixing hole 48 of the worm gear 8 and has a thickness of 2 mm or more so as to be fixedly fitted to the fixing hole 48 of the worm gear 8 .
[0039] The worm gear 8 rotated by the rotation of the motor 13 has a mounting protrusion 46 formed at the front end thereof in such a manner as to be coupled to a gear-mounting groove 47 formed in the lower case 3 .
[0040] The gear-mounting groove 47 is adapted to prevent the worm gear 8 coupled to the mounting protrusion 46 from being moved or rolled and has the same length as the mounting protrusion 42 inserted thereinto or has a little extended length from the mounting protrusion 42 so as to prevent the worm gear 8 from being forwardly and backwardly moved by the gap caused by the rotary shaft of the motor 13 .
[0041] FIG. 5 is a view showing the reverse twisting state of the ice-making container so as to separate the ice cubes from the ice-making container, and after the ice-making is completed in the initial driving of the ice maker-driving device, as shown in FIG. 7 , an initial output signal is transmitted so as to reversely rotate the motor 13 such that the ice-separating lever 5 is reversely rotated by 45°, and since the other side support projection 42 of the ice-making container 36 coupled to the ice-separating lever 5 cooperates with a support inclined part 43 of a housing of the ice-making container 36 upon the reverse rotation of the ice-separating lever 5 , the ice-making container 36 is twisted by 45° or more.
[0042] FIG. 6 is a perspective view showing the cam structure formed on the underside of the third wheel gear 11 , wherein the stopper 12 coupled to the fixing shaft 18 is rotated by the friction force against the fixing shaft-coupling part 34 and has the lever-fixing protrusion 22 adapted to fix the spin lever 7 thereto. The cam section bent parts 32 has the locking projection 12 ′ adapted to prevent the stopper 12 from being unlimitedly rotated by the friction between the fixing shaft 18 and the fixing shaft-coupling part 34 in fixing the spin lever 7 by means of the lever-fixing protrusion 22 .
[0043] FIGS. 8 a and 8 b are flow charts showing the ice maker-driving device according to the present invention, wherein the operation time for the ice quantity-checking of the timer is shorter than that in the conventional practice, and after the initial setting and the ice-making are finished, the ice-making container is reversely rotated to have the rotary angle of 45°.
[0044] As described above, there is provided the ice maker-driving device for a refrigerator which is operated to perform an ice quantity-checking operation after the ice-making operation of the ice-making container and to supply the ice cubes to the ice-storing container. However, in the conventional practice, the ice-making container is generally driven in a forward rotating direction after the ice-making operation, and it is not easy to adopt the cam structure or stopper by which the reverse rotation of the ice-making container is performed by a predetermined angle or more. Further, it is very difficult to expect the necessity of the adoption of the cam structure or stopper in the conventional practice.
[0045] Also, it is difficult to separate the ice cubes expanded in the ice-making container from the ice-making container only with the rotation of the ice-making container according to the ice quantity-checking operation. Thus, in order to solve this problem, the ice-making container is fixed at one side and is reversely rotated at the other side thereof, such that the ice-making container is twisted to protect the freezing and to separate the ice cubes therefrom before the ice-separating operation.
[0046] Further, the arrangement of the parts in the body is effectively made such that the ice quantity-checking lever and the locking projection of the rotary radius control stopper are freely formed, the stopper is rigidly fixed to the fixing shaft of the lower case, and the worm gear has the durability against impacts and vibration, thereby achieving a semi-permanent lifespan and a substantially low error rate. Also, the stable supply of power from a capacitor ensures the operation of the sensor mounted on the printed circuit board, thereby obtaining durability and persistent operation in the device.
[0047] While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention.
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The present invention relates to an ice maker-driving device for a refrigerator and a method for operating the same wherein the ice-making container connected to the ice-separating lever and rotated by initial circuit set is reversely rotated before forward rotation and has a protruded coupling part having a predetermined angle formed on the other side thereof, without any cooperation with the ice-separating lever, so as to be coupled with a case-fixing part, thereby allowing the ice-making container to be twistedly rotated at one side thereof according to the reverse rotation of the ice-separating lever, such that the separation of ice cubes is conducted and also the stress and tense state of the parts caused by their freezing are removed to prevent their malfunction, thereby efficiently achieving the ice-separating and storing operations.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a safety valve for a subterranean well of the type employing a pivotally movable flapper which cooperates with an annular valve seat defined on a well conduit.
2. Description of the Prior Art
Flapper type safety valves have long been employed in subterranean wells. One of the common forms of actuating mechanisms for such flapper valve is an actuating sleeve having a piston shoulder formed thereon upon which fluid pressure is imposed to drive the sleeve downwardly and thus pivot the flapper valve from a transverse, closed position to a vertical, open position. Due to the accumulation of tolerances involved in the assemblage of the flapper valve and the actuating sleeve to the well conduit, it often happens that the actuating sleeve engages the upper surface of the flapper valve at a point that is closely proximate to the pivot mounting axis of the flapper valve. In many cases, the well pressure below the flapper valve is in excess of the fluid pressure existing above the valve so a substantial fluid pressure differential exists across the flapper valve opposing its movement. If the actuating sleeve only contacts the flapper valve at a region close to its pivotal axis, it is obvious that a substantially greater force must be applied by the sleeve to the flapper valve to effect its opening.
In addition to the high opening forces which can be created by a pressure differential from below a flapper valve, problems can also arise as the flapper valve closes under large pressure differentials. Damage can result when the flapper valve, moving rapidly under the influence of large pressure differentials, strikes the stationary valve seat. Damage to the flapper valve, to the valve seat and to the hinge pin can seriously affect the performance of a flapper type safety valve.
In prior art flapper valves, such as that shown in U.S. Pat. No. 3,375,874, protrusions extending from the outer edges of the upper surface have been used to establish initial contact between the flapper valve and a flow actuating tube at a location spaced from the hinge or pivot of the valve. These spaced protrusions have served to increase the moment acting on the flapper valve in opposition to pressure differentials below the valve. These protrusions can, however, create space problems when the valve is open and the actuating sleeve extends past the protrusions and can reduce the flow area available through the valve when a flapper valve having a flap upper surface is used.
One means of providing additional space to permit full opening of the flapper valve is to utilize an eccentric housing. For example the safety valve shown in U.S. Pat. No. 3,726,341 employs an eccentric housing used with a flapper having a laterally offset pivot or axle means.
One other means of solving this space problem is disclosed in U.S. patent application Ser. No. 280,039 filed July 6, 1981. This flapper valve configuration is equivalent to a section cut through a tubular member about an axis normal to the axis of the tubular member.
The flapper valve disclosed and claimed herein combines a structure adapted to overcome the problems arising from large pressure differentials existing below the valve and the dimensional constraints required for a valve with the largest possible flow area. The configuration of the valve and the flapper components also results in a high degree of strength for the operating mechanism so that the valve can be used in the presence of large forces.
SUMMARY OF THE INVENTION
In accordance with this invention, a flapper valve is pivotally mounted to one side of a tubular conduit and is provided with an annular sealing surface that cooperates with a downwardly facing, conical segment sealing surface formed on the well conduit. An actuating sleeve is vertically reciprocable in the tubular conduit and downward movement of the sleeve will effect its engagement with the upper surface of the flapper valve to apply downward opening force to the flapper valve. In accordance with this invention an inclined elevated upper surface of the flapper valve insures that the actuating sleeve will contact the flapper valve at a position remote from the pivotal axis of the flapper valve. Additionally, the elevated surface of the flapper is provided with a cylindrical segment recess of substantially the same diameter as the exterior diameter of the actuating sleeve and disposed relative to the pivotal axis of the flapper so as to snugly conform to the actuating sleeve when the flapper valve is shifted to its fully open, vertical position. The recess minimizes the interference between the flapper valve and the actuating sleeve in the open position and increases the available flow area.
The flapper is pivotally mounted on the eccentric flange of a flapper base which can be transversely inserted through the concentric bore of the valve housing. The base, with flapper attached, can be rotated in the eccentric bore in the valve housing. A cylindrical support member can then be attached to the housing and this support secures the flapper, the flapper base, and the valve seat in position.
Further objects and advantages of the invention will be readily apparent to those skilled in the art from the following detailed description, taken in conjunction with the annexed sheet of drawings on which is shown a preferred example of the invention.
BREIF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal cross-section of the flapper type valve showing the flapper in the closed position.
FIG. 2 is a view similar to FIG. 1 but showing the flapper in the open position.
FIG. 3 is an exploded perspective view showing the flapper, the flapper base, the valve seat and the cylindrical support member.
FIG. 4 is a longitudinal section of the valve housing showing the transverse insertion of the flapper base with flapper attached during assembly of the valve.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, there is shown a portion of a safety valve 2 having an eccentric bore housing member 4 and incorporating the flapper actuating mechanism embodied in this invention. The valve housing 4 has an upper concentric bore 6 and an intermediate inner eccentric bore 8 contained within the eccentric housing section 10. The external diameter of the eccentric housing section 10 is greater than the external diameter of the tubular conduit 7 which comprises the upper housing of the safety valve and is attached to flapper housing 4 by means of threaded connections 9.
A longitudinally reciprocal cylindrical actuating sleeve 16 is located on the interior of housing 4 and extends concentrically within housing bore 6. Actuating sleeve 16 extends upwardly within a conventional valve upper housing, which is not shown herein. This upper housing can comprise a spring member urging the actuating sleeve upward and a control fluid pressure chamber acting on an appropriate surface on sleeve 16 to urge this actuating member downward. This configuration is conventional, and tubing mounted or wireline downhole safety valves actuated by means of an external control fluid pressure line are quite common.
The lower portion of valve housing 4 comprises a section having an internal bore 12 which is concentric and has a larger internal diameter than the upper concentric bore 6. Conventional threads 14 extend along the inner surface of the lower section of the valve housing 4.
A circular flapper valve 20 is shown in its horizontal closed position in FIG. 1. On the upper surface of flapper 20, the outer or peripheral annular conical sealing surface is configured to sealingly engage a conical valve seat 32 and its companion annular elastomeric seal 26. The flapper 20 is provided with integral hinge portions 24 which receive a pivot pin 44 to pivotally mounting the flapper 20 within eccentric bore 8. A torsion spring (not shown) is conventionally wrapped around pivot pin 44 to exert an upward pivotal bias on flapper 20 urging it to its closed, sealed position.
As is well known to those skilled in the art, the flapper 20 may be moved to its open position through the downward movement of actuating sleeve 16. Forcible downward movement of the actuating sleeve 16 will overcome overcome the bias of the torsion spring acting on the flapper 20 and substantial fluid pressure differentials in the order of several hundred pounds per square inch acting to keep the valve in a closed position. The flapper will thus be rotated downwardly to a substantially vertical open position illustrated in FIG. 2. In order to assure that the bottom edge of actuating sleeve 16 always contacts the flapper 20 at a position maximumly spaced from the axis of the pivot pin 44, flapper valve 20 is provided with an elevated top surface 22 which in this embodiment comprises a planar surface sloping upwardly and away from the aixs of pivot mounting pin 44 at an angle of approximately 5°. With this configuration, the bottom edge portions of the actuating sleeve 16 that are spaced away from the axis of the pivot mounting pin 44 will provide the first contact with the flapper 20 at a position providing essentially the maximum possible moment arm about the pivotal axis of the flapper mechanism. The actuating sleeve will initially strike the annular conical sealing surface 21. Because of the elevation of surface 22, the initial points of contact will lie above the cooperable sealing surface of the valve seat and will be spaced from the hinge. Thus, the flapper valve 20 may be opened even though a substantial fluid pressure differential exists across the valve, without incurring the risk of damaging the flapper 20, its pivot mounting pin 44, or the actuating sleeve 16.
When the flapper closes in the presence of a substantial fluid pressure differential, which can result in rapid closure of the flapper because of the large forces acting on it, the flapper will initially strike the actuating sleeve 16 rather than the valve seat 32. The actuating sleeve which is urged downward by fluid pressure will serve to damp the movement of the flapper as the flapper valve exerts a force in the upward direction. During closure, the actuating sleeve will engage the conical sealing surface 21 at a point adjacent the hinge 24, and as the flapper closes will progressively engage the conical sealing surface 21 around the remainder of the upper circumference of the flapper.
The elevated surface 22 is further provided with an arcuate, cylindrical segment recess 23. Recess 23 has a curvature corresponding to the external diameter of the actuating sleeve 16 so that it snugly conforms to the actuating sleeve 30 when the flapper lies in its fully open, vertical position, as illustrated in FIG. 2. Recess 23 permits complete opening of the flapper without reducing the flow area through actuating sleeve 30 and through the valve itself or without unduly increasing the size or reducing the thickness of valve housing 4. Recess 23 not only extends through the elevated upper surface 22 but also extends through the conical sealing surface 21 adjacent the exterior of the flapper. The intersection of the sealing surface 21 with inclined elevated surface 22 on opposite sides of recess 23 thus defines the two uppermost extensions of the flapper valve 20. It is at these two points, spaced from hinge 24 and from the axis of the valve where resultant pressure forces will act, that the actuating sleeve will initially contact to open flapper valve 20. Adequate sealing area will still exist on surface 21 below recess 23 to fully contact annular conical valve seat 18 when the valve is closed.
Valve seat 18 comprises an annular metallic member which can be inserted into the housing 4 from its lower end. An O-ring seal 28 is located along the exterior of valve seat 18 to provide sealing integrity between the valve housing and the valve seat. An annular elastomeric seal 26 is disposed around the exterior of the lower portion of valve seat 18. Sealing integrity can thus be established along the downwardly facing conical seating surface 18a and with the lower end of resilient seal 26. Note that valve seat 18 is held in position by the abutment of an upper surface 18b with a downwardly facing shoulder 4a located on the eccentric valve housing. In this embodiment of the invention, the valve seat is positioned above the eccentric bore 8 of valve housing 4.
Flapper 20 is mounted on a separate annular flapper base 30 shown in FIG. 3. Flapper base 30 comprises a cylindrical section 32 and an eccentric projecting flange portion 34. Flange 34 has two offset bearings 36 and 38 each of which has aligned sockets 40 and 42 for receipt of hinge pin 44. Note that the diametrically opposed sides of flange 34 are substantially tangential to the exterior of cylindrical section 32.
As shown in FIGS. 1 and 2 flapper base 30 is positioned in abutting relationship with valve seat 18 in the assembled configuration of this valve. Flapper base 32 with its eccentrically projecting flange 34 is positioned within eccentric bore 8. As shown in FIG. 4 flapper base 30 may be transversely inserted through the lower concentric bore 12 of housing 4. The tangential sides of flange 34 permit insertion of flapper base 30 through the housing with the axis of cylindrical section 32 extending generally perpendicular to the axis of valve housing 4. When the flapper base, with flapper 20 attached has been fully inserted into eccentric bore 8, the flapper base 32 may be rotated into the assembled position of FIGS. 1 and 2.
After insertion of flapper base 30 into the valve housing 4 a cylindrical support sleeve 46 may also be inserted from the lower or upstream side of valve housing 4 through lower concentric bore 12. This valve support member is shown in FIG. 3. Note that cylindrical support sleeve 46 has been rotated to clearly show the cutout section 48 which provides clearance for the opened flapper 20. Adjacent the upper edges of sleeve 26 are two oppositely facing upwardly extending arcuate segments 50 and 52 which abut the offset bearing surface 36 and 38 in the assembled flapper configuration. The upper end 53 of support sleeve 46 also abuts the upstream surface of flapper base 30 to firmly secure the flapper base between support sleeve 46 and valve seat 18. The flapper mechanism is firmly secured in position upon insertion of a lower cylindrical body section 54 which has external threads 58 for engaging the internal threads 14 on the lower section of valve housing 4. When lower body section 54 is fully engaged with valve housing 4 and upper surface 60 provides a lower limit to the travel of actuating sleeve 16. As can be seen in FIG. 2 downward movement of actuating sleeve 16 causes flapper 20 to rotate to its fully open position at which time actuating sleeve 16 can extend through the arcuate recess 23 and the upper surface of flapper 30. The lower end of actuating sleeve 16 thus abuts limit surface 60 and covers the sealing surfaces of the flapper mechanism while the valve is in the open configuration.
Although the invention has been described in terms of the specified embodiment which is set forth in detail, it should be understood that this is by illustration only and that the invention is not necessarily limited thereto, since alternative embodiments and operating techniques will become apparent to those skilled in the art in view of the disclosure. Accordingly, modifications are contemplated which can be made without departing from the spirit of the described invention.
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The disclosure relates to an improved flapper type saftey valve and valve housing for use in subterranean wells wherein the flapper valve is actuated from a horizontal closed position to a vertical open position by contact with a downwardly moving actuating sleeve. The top surface of the valve is elevated so that the bottom edge of the actuating sleeve always contacts the flapper valve at a position spaced from the axis of the pivot mounting, thereby assuring that the opening force applied to the flapper valve has a maximum moment arm in order to overcome any fluid pressure differential existing across the flapper valve. The valve is mounted in an eccentic bore on an eccentric mounting base and fully opened flapper valve provides maximum flow area through the valve.
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BACKGROUND OF THE INVENTION
The present invention relates to a reading device for a dobby machine.
There is known a reading device in which a reading lever is adapted to rotate and shift between two positions around a single shaft according to whether a peg on a rotating cylinder is present. A retaining hook is pivotably mounted on said shaft and connected to the reeding lever through a spring. The reeding lever and retaining hook are integrally rotatable. The retaining hook is adapted to take engaged and disengaged positions with respect to a periodically pivoting movable hook.
More particularly, an intermediate position of a balk which pivotally supports movable hooks at both ends thereof is rotatably supported by a fore end portion of a balk lever which is pivotable around a fixed shaft independent of the shaft of the reading lever. The movable hooks at both ends of the balk are adapted to move with the pivotal motion of the balk between engaged and disengaged positions with respect to the retaining hook by being pushed with pushing bars which are adapted to reciprocate in opposite directions alternately at a 180° shift.
Therefore, when the movable hook on one side of the balk is pushed by a pushing bar and reaches the position of engagement with the retaining hook while the retaining hook integral with the reading lever displaced in abutment with the peg on the cylinder is located in the engaged position, the retaining hook is slightly moved forcibly by the movable hook against the force of the spring connected to the reading lever, so that the movable hook and the retaining hook come into engagement with each other. Further, as the movable hook portion on the opposite side is pushed by a pushing bar, the balk lever turns around the fixed shaft and a heald frame ascends or descends through a jack lever connected to the said balk lever and a wire rope, whereby a warp shedding is performed.
In the above dobby machine, the reading lever and the retaining hook are supported coaxially rotably and a spring is connected between the reeding lever and the retaining hook so that the reading lever and the retaining hook are integrally rotatable while the reading lever is in pressure contact with a stopper on the retaining hook. Further, the retaining hook is urged away from the movable hook by means of a spring disposed between the retaining hook and another fixed pin. This urging force also serves to urge the reading lever against the peg on the cylinder.
In such reading device, when the reading lever is displaced by the peg on the cylinder, the retaining hook turns at the same angle as the turning angle of the reading lever; that is, the angular velocity of the reading lever and that of the retaining hook are equal. Therefore, the turning speed of the retaining hook from its disengaged to engaged position with respect to the movable hook is constant, so at a high speed, e.g. 500-1000 r.p.m., of the dobby machine, there may occur shock or vibration and out-of-engagement with the movable hook when the retaining hook reaches its position of engagement, or sudden movement and stop may cause a crack of the weaker member at the portion of abutment between the reading lever and the retaining hook.
Further, as to the urging force of the reading lever against the peg, the force of an exclusive-use spring acts directly as such urging force as previously noted, so the extension of the spring with displacement of the reading lever directly increases the load to the peg, thus accelerating wear of the peg surface. Besides, with speed-up of the dobby, the peg strongly abuts and displaces the reading lever, so there may occur breakage due to impact fatigue of the weaker member, thus shortening the service life.
It is the object of the present invention to solve the above-mentioned problems.
SUMMARY OF THE INVENTION
In the present invention, a reading lever adapted to shift between two positions according to whether a peg is present or not is supported on a first fixed shaft. A retaining hook, adapted to be displaced by the reading lever between two positions of engagement and disengagement with respect to a movable hook, is supported on a second fixed shaft. The reading lever having a slider which is in abutment with a slide surface formed on the retaining hook. A spring acting in a direction in which the slider comes into pressure contact with the above slide surface is connected between the reeding lever and the retaining hook. The first and second fixed shafts are disposed in such a positional relation that when the retaining hook turns while the slider slides along the slide surface of the retaining hook as the reading lever turns at a constant speed, the turning speed of the retaining hook gradually decreases when the hook turns toward the position of engagement and gradually increases when it turns toward the position, of disengagement.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view illustrating an embodiment of the present invention.
FIG. 2 is a schematic front view of a dobby machine to which is applied the present invention.
FIG. 3 is a plan view of a portion of FIG. 1.
FIG. 4 is an explanatory view showing displacements of the retaining hook and a reading lever.
FIG. 5 is an explanatory view showing a non-uniform angular velocity motion of the retaining hook which follows the reading lever.
FIG. 6 is a front view illustrating another embodiment of the present invention.
FIG. 7 is a view illustrative of operations thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the present invention will be described hereinunder with reference to the drawings.
Referring to FIG. 2, there is schematically illustrated a construction of a dobby machine, in which reading levers 3a and 3b, adapted to turn and shift between two positions according to whether a peg 2 on a cylinder 1 is present or not are pivotably mounted on first fixed shafts 4a and 4b. Retaining hooks 5a and 5b adapted to turn and shift with displacement of the reading levers 3a and 3b are pivotably mounted on second fixed shafts 6a and 6b.
Between the reading lever 3a and the retaining hook 5a is disposed a tension spring 7a. The reading lever 3a and the retaining hook 5a substantially perform an integral movement on the basis of a principle as will be described later. Also between the other reading lever 3b and retaining hook 5b is disposed a tension spring 7b and the same operation is performed. The numerals 8a and 8b denote positioning stoppers for disengaged positions of the retaining hooks 5a and 5b.
On the other hand, an intermediate portion of a balk 12 having movable hooks 11a and 11b at both ends thereof is pivotably supported at 13 by the fore end portion of a balk lever 10 which is pivotably mounted on another fixed shaft 9, the balk 12 being pivotable around the shaft 13. The movable hooks 11a and 11b at both ends of the balk 12 are supported pivotably relative to shafts 14a and 14b and are engageable and disengageable with respect to the retaining hooks 5a and 5b.
Pushing bars 17a and 17b adapted to pivot in the directions of arrows 15 and 16 through a shaft (not shown) of the dobby machine which is driven interlockedly with a weaving machine. Pushing bars 17a and 18b extend in the direction orthogonal to the paper surface, that is, they extend beyond the balk 12. These bars alternately push the movable hooks 11a and 11b, thereby allowing the balk 12 to pivot about the shaft 13 or allowing the balk lever 10 to turn about the shaft 9 when one movable hook is engaged with a retaining hook. More specifically, in the case where the retaining hook 5a opposed to the movable hook 11a is already in this position of engagement when the balk 12 is turned in a clockwise direction around the shaft 13 while the pushing bar 17a pushes the upper movable hook 11a in the direction of the arrow 15, a cam surface 18a of the movable hook 11a pushes the retaining hook 5a and forces the latter to turn slightly around the shaft 6a. Upon reaching the position of engagement, i.e., the position shown in FIG. 2, the retaining hook 5a is brought into engagement with the movable hook 11a by the spring force.
Subsequently in the state of FIG. 2, the pushing lever 17b moves in the direction of arrow 16' while pushing the lower movable hook 11b, whereby the balk lever 10 which supports the balk 12 is turned in a clockwise direction around the fixed shaft 9 because the balk 12 is now fixed at one end thereof by the retaining hook 5a.
Consequently, a jack lever 21 connected to the balk lever 10 through a connecting rod 19 and an adjuster 20 turns clockwise about a fixed shaft 22, and a heald frame (not shown) suspended from a wire rope connected to the jack lever 21 ascends or descends through the wire rope to control a shedding motion of warp.
Principal portions of the above reading device will now be explained with reference to FIGS. 1 and 3. Although FIG. 1 shows only one retaining hook 5a and reading lever 3a out of the paired retaining hooks 5a, 5b and reading levers 3a, 3b, the other retaining hook 5b and reading lever 3b are also of the same structure and disposed symmetrically with respect to a middle point of line joining the centers of the shafts 6a and 6b.
In FIGS. 1 and 3, the reading lever 3a, which is pivotably mounted on the first fixed shaft 4a, comprises a first arm 24 having a cam surface 23 adapted to abut the peg on the cylinder. A second arm 25 is connected to the retaining hook 5a through the spring 7a, and a third arm 27 has a slider 26 in abutment with the slide surface of the retaining hook 5a. The first, second the third arms 24, 25 and 27 are integrally formed of a rigid material.
The retaining hook 5a, which is pivotably mounted on the second fixed shaft 6a parallel with the first fixed shaft 4a, comprises a first arm 29 having a hook portion 28 adapted to engage the movable hook. A second arm 30 is connected through the spring 7a to the second arm 25 of the reading lever 3a, and a third arm 32 has a slide surface 31 in abutment with the slider 26 of the reeding lever 3a. The first, second and third arms 29, 30 and 32 are integrally formed of a rigid material.
The second arms 25 and 30 respectively of the reading lever 3a and the retaining hook 5a are in an opposed relation to each other with respect to the second fixed shaft 6a. An urging force acting in a counterclockwise direction about the shaft 4a is imparted to the reading lever 3a, while an urging force acting in a clockwise direction about the shaft 6a is imparted to the retaining hook 5a, thereby causing a compressive force to be exerted on a contact portion C between the slider 26 and the slide surface 31.
The tensile force of the spring 7a is assumed to be F, and the distance between the axis P of the retaining hook 5a and a work point M of the spring 7a on the second arm 30 is l1. The distance between the axis P and the contact point C is l2. The distance between the axis Q of the reeding lever 3a and a work point N of the spring 7a on the second arm 25 is l3. Additionally, the distance between the axis Q and the contact point C is 14. The distances l1 to l4 are set to satisfy the following relationship in terms of length: l1<l2, l3>l4.
The compressive force at the contact point C will now be explained. Assuming that the moment induced by the tensile force F of the spring 7a is sufficiently larger than that induced by the own weight of the reading lever 3a and retaining hook 5a, a pushing force F1 of the retaining hook 5a against the reeding lever 3a is
F1=(l1/l2)·F (a)
and a pushing force F2 of the reading lever 3a against the retaining hook 5a is
F2=(l3/l4)·F (b)
Thus, from (a) and (b)
F2=(l2/l1)·(l3/l4)·F1 (c)
Where, from l2>l1 and l3>l4,
(l2/l1)·(l3/l4)>1 (d)
therefore
F2>F1
Thus, the pushing force of the reading lever 3a against the retaining hook 5a becomes larger, so that the reading lever 3a and the retaining hook 5a undergo an urging force in a counterclockwise direction about the shafts 4a and 6a. When the cam surface 23 of the reading lever 3a is not engaged with the peg of the cylinder 1, the retaining hook 5a is brought into the position restricted by the stopper 8a, namely, its disengaged position from the movable hook. The spring 7a has the function of connecting the reading lever 3a and the retaining hook 5a integrally with each other and the function of urging the cam surface 23 of the reading lever 3a against the peg 2.
In FIG. 1, the alternate long and two short dashes line 2 represents the locus of the fore end of the peg 2 on the cylinder and the like line 1 represents the outer peripheral surface of the cylinder. When the cam surface 23 of the reading lever 3a is engaged with the peg 2 it is displaced, and thereby the hook portion 28 of the retaining hook 5a is brought into the position of engagement with the movable hook.
Instead of the pin provided on the third arm 27 as the slider 26 of the reading lever 3a, there may be used a roller, or a part of the arm 27 may be enlarged in wall thickness, or an end portion of the third arm 27 may be subjected to bending and quench hardening. (For simplicity, hereinafter each of these embodiments is referred to as a "slider." In the case where a roller is used, the "slide" surface 31 should, of course, be considered a rolling surface.)
The reading device having the above-described construction operates in the following manner.
In FIG. 4, when the peg 2 reaches the cam surface 23 of the reading lever 3a with rotation of the cylinder 1 in the direction of arrow 33, the reading lever 3a pivots from an alternate long and two short dashes line position 3a1 to a solid line position 3a about the first fixed shaft 4a. At this time, since the slide surface 31 of the retaining hook 5a is urged against the slider 26 of the reading lever 3a by the spring 7a, the retaining hook 5a follows the reading lever 3a and pivots from an alternate long the two short dashes line position 5a1 to a solid line position 5a about the second fixed shaft 6a, so that the hook portion 28 reaches the position of engagement with the movable hook.
With the pivotal motion of the reading lever 3a and the retaining hook 5a, a contact point Ci between the slider 26 and the slide surface 31 changes in its distance in a radial direction from the center of the second shaft 6a. However its distance from the center of the first fixed shaft 4a is constant. In other words, during the pivotal motion of the retaining hook 5a from the disengaged position 5a1 to the engaged position, the distance from the center of the second shaft 6a to the contact point Ci gradually increases. Conversely, while the retaining hook 5a pivots from the engaged to disengaged position, the distance between the contact point Ci and the center of the second fixed shaft 6a gradually decreases. This has a special meaning for the speed-up of the dobby machine as will be explained later.
When the retaining hook 5a reaches its solid line position, i.e., the position of engagement with the movable hook, and engages the movable hook 11a which is pushed by the periodically reciprocating pushing bar 17a shown in FIG. 2, the cam surface 18a of the movable hook 11a moves up to the position of engagement and pushes down the retaining hook 5a to an alternate long and short dash line position 5a2 in FIG. 4. The retaining hook 5a is again returned to its solid line position by the force of the spring 7a, whereby the engagement with the movable hook is attained. Of course, the motion of the retaining hook 5a being pushed down by the movable hook 11a means the motion of the lower retaining hook 5b in FIG. 2 being pushed up. During this motion, the reading lever 3a is held in place by the peg 2, so the slide surface 31 of the retaining hook 5a shifts to an alternate long and short dash line position 31 a as shown in FIG. 4, that is, it temporarily leaves the slider 26 of the reading lever 3a, thereby permitting relief of the retaining hook 5a.
When the retaining hook 5a pivots from its disengaged to engaged position, the spring 7a will follow the pivotal motion of the retaining hook and so extend if one end of the spring is fixed. But in the above embodiment, both ends of the spring 7a move in the same direction, so the extension of the spring is slight. Consequently, the occurrence of vibrations attributable to the expansion and contraction of the spring is disengaged. This is presumed to be one cause of the difficulty of occurrence of irregular vibrations even at a high speed rotation of the dobby machine, namely, at pivotal motions of short cycle of the retaining hook, reading lever, etc.
Characteristics of follow-up pivoting motions attained by supporting the reading lever 3a and the retaining hook 5a on separate shafts will now be explained with reference to FIG. 5. In FIG. 5 the pivoting amount of the reading lever 3a and that of the retaining hook 5a exaggerated for convenient explanation, but actually those amounts are as shown in FIG. 4, provided the tendency of motion is the same in both figures.
In FIG. 5, the reading lever 3a performs a uniform motion, and an arcuate locus L around the axis Q represents the locus of the contact point C of the slide surface 31. If contact points C1 to C13 are divided by equal angles than the angle, for example, between contact points C1 and C4, between contact points C4 and C7, between contact points C7 and C10 and between contact points C10 and C13 with the axis Q as the center are all α. On the other hand, the angle between contact points C1 and C4 with the second axis P as the center is β1, and this means that while the reading lever 3a turns between contact points C1 and C4, the retaining hook 5a turns by an angle of β1. Likewise, if the angles between contact points C4 and C7, between C7 and C10 and between C10 and C13 with the axis P as the center are β2, β3 and β4, respectively, there exists the following relationship:
β1<β2<β3<β4
Since the angles of the contact points C1 to C13 with respect to the axis P are points on the slide surface 31 of the retaining hook 5a, the hook portion 28 of the first arm 29 integral with the third arm 32 having the slide surface 31 also pivots in the same manner. While the third arm 32 moves between C1 and C13, the hook portion 28 moves between B1 and B13 at the same angle. More specifically, the positions of the hook portion corresponding to the contact points C1, C4, C7, C10 and C13 are B1, B4, B7, B10 and B13, respectively. That is, while the reading lever 3a performs a uniform motion, the retaining hook 5a performs a non-uniform motion, and when the retaining hook 5a pivots in the direction of arrow 34, the angular velocity decreases gradually, while when it turns in the direction of arrow 35, the angular velocity increases gradually.
Referring now to FIG. 6, there is illustrated a reading device according to another embodiment of the present invention in which a reading lever 42, pivotably mounted on a first fixed shaft 41, has a cam surface 23 adapted to abut a peg 2 and a slider 45 which is in pressure contact with a slide surface 44 of a retaining hook 43. On the other hand, the retaining hook 43, which is pivotably mounted on a second fixed shaft 46, has a hook portion 28 adapted to engage a movable hook of the same structure as previously described and also has the slide surface 44 which is in contact with the slider 45 of the reading lever 42.
The reading lever 42 and the retaining hook 43 are urged by a spring 47 in a direction in which the slider 45 and the slide surface 44 are kept in pressure contact with each other. The retaining hook 43 performs a pivotal motion with displacement of the reading lever 42. Further, a tension spring 48 is connected between the retaining hook 43 and a retaining hook (not shown) similar thereto provided in a symmetrical position with respect to the cylinder 1.
Since the biasing force of the spring 47 is set larger than that of the spring 48, the reading lever 42 and the retaining hook 43 are urged integrally by the spring 48 in a direction in which the reading lever 42 is brought into pressure contact with the peg 2. Therefore, as the reading lever 42 is disengaged from the peg 2 and pivots from the solid line position 42 to an alternate long and short dash line position 42a by virtue of the spring 48, as shown in FIG. 7, the slider 45 on the reading lever 42 moves along the slide surface of the retaining hook 43, that is, in a direction in which the distance between the axis P of the second fixed shaft 46 and the contact point C becomes shorter Meanwhile the retaining hook 43 pivots in a counterclockwise direction and the hook portion 28 moves to a disengaged position.
Alternately, when the retaining hook 43 engages the movable hook in its position of engagement, only the retaining hook 43 pivots counterclockwise at a slight angle about the axis 46 against the spring 47, as in the previous embodiment, and the contact point C opens, thus permitting relief of the hook portion 28.
Also in this embodiment, the reading lever 42 and the retaining hook 43 are supported by the separately provided first and second fixed shafts 41 and 46, respectively. Both the reeding lever 42 and retaining hook 43 perform a pivoting motion while the slider 45 of the reeding lever 42 moves along the slide surface 44 of the retaining hook 43. Therefore, as in the previous embodiment, while the reading lever 42 performs a uniform angular velocity motion, the retaining hook 43 pivots while changing its angular velocity. Thus, it is possible to perform about the same motion as in FIG. 5.
In the present invention, as set forth hereinabove, the retaining hook adapted to take engaged and disengaged positions with respect to the movable hook while following the reading lever which shifts between two positions according to whether a peg is present or not, performs a pivotal motion of non-uniform angular velocity so that the angular velocity decreases gradually when the retaining hook pivots from its disengaged to engaged position, while the angular velocity increases gradually when the retaining hook pivots from its engaged to disengaged position. Consequently, at the time when the retaining hook reaches it position of engagement or when it is disengaged from the movable hook, a sudden motion thereof is cushioned, that is, such shock and vibration created at the time of start and stop of a uniform motion are cushioned, thus permitting speed-up of the dobby machine, for example, permitting operation of a double lift dobby machine at 1,000 r.p.m.
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In a reading device for a dobby machine, the reading levers and retaining hooks are pivotally mounted on separate axes. Each reading lever rotates a retaining hook so that the angular velocity of the retaining hook decreases as the retaining hook pivots from its disengaged to engaged position and increases when the retaining hook is disengaged. This acceleration and deceleration cushions the impact that the retaining hook experiences with changes in rotational direction.
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This is a continuation of application Ser. No. 06/677,628, filed Dec. 3, 1984, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to an inflatable evacuation slide device and more particularly to an inflatable slide for use on elevated trains where there is a restricted clearance space on either side of the railway car. Heretofore, the evacuation of passengers from elevated trains was substantially non-existent except for use of existing structural supports and conventional platforms at spaced intervals. Conventional slides that deployed transversely of the length of the train had limited application. The present invention is directed to a novel inflatable escape slide which provides a cantilever type inflatable porch or platform immediately adjacent a side exit or access door of a train which in turn is connected to an inclined inflatable slide which is deployed in a direction parallel to the length of the train thereby insuring its proper deployment under substantially all conditions of evacuation need including very restricted right of way clearances thus insuring the safety of passengers under all conditions of use.
SUMMARY OF THE INVENTION
An inflatable evacuation slide for an elevated vehicle such as a train wherein the escape slide has a platform located immediately adjacent one of the exit doors of the vehicle to facilitate the movement of passengers away from the vehicle. The platform is connected to an inflatable slide that lies in the same general direction as the train thus enabling its deployment where there is little clearance space along the path of train's movement.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a multi-ribbed inflatable escape slide extending from an elevated train to the ground with the slide shown in phantom lines wherein the distance between the train and ground level is reduced.
FIG. 2 is a front elevational view of the inflatable escape slide of FIG. 1 taken on line 2--2 showing the elevated train.
FIG. 3 is an enlarged plan view of that portion of the inflatable slide adjacent the train.
FIG. 4 is a partial side elevational view of the upper portion of the inflatable escape slide, partly in cross-section, taken on line 4--4 of FIG. 3.
FIG. 5 is a cross-sectional view of the inflatable escape slide taken on line 5--5 of FIG. 3 showing a portion of the train and the storage compartment and its hinged door.
FIG. 6 is a cross-sectional view of the inflatable escape slide taken on line 6--6 of FIG. 1.
FIG. 7 is a partial cross-sectional view of the elevated train with the escape slide stored in a storage compartment therein and showing in phantom lines a portion of the escape slide deployed.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings wherein like reference numerals designate like or corresponding parts throughout the several views, there is shown in FIG. 1 a train 10 mounted for movement on one of a pair of laterally spaced rails 11 which in turn are suitably supported by a plurality of longitudinally spaced columns 12 (only one shown). The train 10 has a plurality of access doors 13 spaced along its one side to facilitate the loading and unloading. Mounted to one side of selected doors of the train is a storage means 15 (FIGS. 5 and 7) for an inflatable escape slide 16.
The storage means or compartment 15 is mounted on a depending support 20 that also journals rollers 21 and 22 which are adapted to engage rail 11. Storage means 15 has a door 23 suitably hinged which upon opening will extend to a horizontal position and held in place by a cable 24 which interconnects the door 23 to a support bracket within the upper portion of the storage compartment 15. The door 23 has a planar support member 25 supporting a pair of horizontally extending inflatable tubes 30 and 31 that extend in a direction outwardly or in a direction that is normal to the access or exit doors 13. Mounted above and transversely of the pair of tubes 30 and 31 are a plurality of inflatable tubes 35, 36, 37 and 38 (FIG. 5). All of such tubes 35 through 38 are suitably bonded to adjacent tubes preferably along their side portions. In addition the tubes 35 through 38 are bonded along their lowermost sides to the top of the horizontally extending tubes 30 and 31. A panel 40 is fastened tangentially to the inflatable tubes 35 through 38 to provide a platform, porch or walkway from the exit passageway of door 13. Such platform or walkway on panel is maintained in a horizontal position when escape slide is deployed by the inflatable tubes 35 through 38 and tubes 30, 31 as well as by the door 23 which is held in a horizontal plane by the cable 24.
The inflatable tube 35 extends upwardly on either side of the door 13 designating such upward extensions of the tube 35 as inflatable tubes 35L and 35R (FIGS. 3 and 5). Tube 35L communicates directly with a horizontally extending tube 41 which in turn communicates directly with a downwardly inclined inflatable tube 42 that communicates in turn with another inclined tube 43 via a short connecting tube 44. Tube 35R communicates directly (FIG. 5) with a horizontally extending tube 45 which in turn communicates directly with a horizontally extending tube 46 that is normal to such tube 45. As shown in FIG. 4 tube 46 communicates with a vertically disposed tube 47 which tube 47 in turn communicates directly with tube 30. Tube 30 has an aspirator 49 (FIGS. 3 and 5) connected thereto which is used to inflate tube 30 and the other tubes connected thereto. Aspirator 49 has a conduit 50 connecting it to a regulator and bottle or reservoir assembly 51 of compressed gas. Aspirators as is well known in the art utilize air from a compressed gas source and aspirate ambient air to inflate life rafts, escape slide, bag or other inflatables. As example of prior art, U.S. Pat. No. 2,975,958 shows an aspirating nozzle, aspirating tube and closure valve. U.S. Pat. No. 3,056,540 shows an aspirating passageway and valves. Also see U.S. Pat. No. 4,368,009 to John Heimovics, Jr. et al which shows another type of aspirator device that is used to inflate escape slides. Inflatable tube 46 (FIGS. 1 and 3) communicates with inclined tube 53 which in turn communicates with inclined tube 55 via connecting tube 56.
The inflatable tubes 36 and 38 which form part of the main support for the platform or porch panel 40 communicate directly with a pair of lower inclined inflatable tubes 58 and 59 respectively, which tubes 58 and 59 have a slide panel 60 suitably attached or adhered to their upper surfaces by any suitable means. The respective lower inclined inflatable tubes 58 and 59 are connected or attached along their upper outer sides to the upper inclined inflatable tubes 43 and 55 forming an escape slide with protective side constraints or guides.
As seen in FIG. 4, inflatable tube 31 is connected via aspirator 62 and conduit 63 to reservoir or bottle 51. The compressed air via aspirator 62 inflates the lower set of tubes such as tubes 31, 36, 37, 38 and tube 65, which in turn communicates directly with inclined tube 59 (as seen in FIG. 1). Inclined tube 59 is suitably adhered along its upper surface to the lower surface of upper inclined tube 55 (FIGS. 1 and 6) to help insure deployment of the escape slide.
A truss bag 78 for side lateral support is also provided midway along the escape slide, transverse to the longitudinal line of the inclined inflatabe tubes 43, 55, 58 and 59. As seen in FIGS. 1 and 6, such truss bag 68 encompasses the escape slide along the bottom and both side portions, communicating with the two upper inflatable tubes 43 and 55. Mounted closely adjacent to the lower cross portion of truss bag 68 is a truss tube 69 fastened to the undersides of the two lower tubes 58 and 59 which is at a position approximately one-half the length of the escape slide. Such truss tube 69 communicates via suitable ports to tubes 58 and 59 and accordingly is inflated simultaneously with such tubes. A truss strap 70 attached at its respective ends to the upper end portion and the lower end portion 72 of the escape slide engages both the truss bag 68 and the truss tube 69, to provide tension to the escape slide and prevent its sagging in the middle of the slide. In the truss arrangement as shown, the truss will function to provide tension to the escape slide with either inflatable truss bag 68 or truss tube 69 deflated and either tube 69 or bag 78 will have approximately the same bending resistance.
The inflatable tubes as deployed are adhesively bonded to each other so that upon inflation will form a rigid supporting porch, or platform and escape slide. The inflatable tubes are preferably fabricated from a neoprene rubber coated nylon fabric. The panel 40 which serves as a walkway for the porch is preferably coated with a non-slip rubber coating to improve the passenger's footing on such walkway. Such panel 40 may be attached to the foot of the exit door by any number of well known means, however as shown in FIG. 5 an exterior flat 71 is suitably attached to a bar 73 located inside the train body thereby supporting the exit door end of the panel or walkway 40.
The slide as shown in FIG. 7 is disposed and folded within the storage means 15 having the swinging door 23 forming part of such compartment confining means. Upon release of the door 23, compressed air from the bottle 51 will inflate via aspirators 49 and 62 their respective sets of tubes. Aspirator 62 is connected to inflatable tube 31 and will inflate such tube immediately. Tubes 36 and 38 which are connected to tube 31 will also inflate as will tube 37, 65, 58, 61, 69 and 59 which are the lower set of inflatable tubes. Aspirator 49 is connected to inflatable tube 30 and will inflate such tube immediately. Tubes 47 (FIG. 4), 46, 45, 35, 41, 42, 43, 53, 68, and 55 are all connected to such tube 30 and will also inflate with such tube, which tubes are considered the upper inflatable set of tubes. Thus, with either and first or second set of tubes inflated, egress can be assured. With the tubes all inflated, the passengers in the train can exit to the platform and then use the deployed escape slide which is disposed in the general direction of the train to assure full deployment of the escape slide under conditions where clearance space to either side of the train ordinarily would present problems of escape slide deployment.
Various modifications are contemplated and may obviously be resorted to by those skilled in the art without departing from the described invention, as hereinafter defined by the appended claims, as only a preferred embodiment thereof has been disclosed.
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An inflatable escape slide having an inflatable platform that provide a horizontal walkway from an elevated vehicle such as a train. An inflatable slide portion is connected to the platform and is deployable in a longitudinal direction that is in the same general direction as the train thus ensuring deployment where clearance space to either side of the elevated train is limited. The escape slide and platform are an integral unit.
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BACKGROUND
This disclosure relates to a method for providing localized heating in an oil well at precise depths to accomplish or expedite specific objectives. The disclosure also relates to the use of a heating tool which can be lowered into an oil well to apply heat at a precise depth to achieve a desired result. The specific objectives may include localized heating of a fresh cement slurry or other sealant having a similar purpose to accelerate curing, or localized heating of recently emplaced chemicals which are formulated to be thermally activated. One purpose of such chemicals is to viscosify or increase in gel strength after being pumped into an oil well production zone, in order to restrict the production of unwanted formation fluids such as water.
Current techniques for cementing steel or other casing in a borehole during oil well construction involve emplacing a fluid cement slurry between the casing and the borehole, after which the cement slurry is allowed to set up or cure to become hard as rock. The cement provides a bond between the casing and the surrounding rock formation. The curing of the cement requires a waiting period which necessarily increases the total time required to construct the well. It is commonly known that the time required for the curing process decreases if the temperature of the cement slurry is increased. Also, to minimize construction cost it is preferred to minimize the time required for the cement to cure. Currently, any heating to accelerate the curing of the cement slurry is provided by the natural surrounding environment as well as the heat generated by the exothermic reactions involved in the cement curing process. Accordingly, it would be desirable to provide a tool to effect an increase in cement slurry temperature to accelerate the curing of the cement slurry.
During the production phase of an oil or gas well, some amount of water may also be produced, which is usually not desirable since the water has no market value. In some wells, the fraction of water produced, relative to the desired fluids, is so great that it impairs well profitability, such that conformance treatments, also known as water shut-off treatments, are performed on the well. Conformance chemicals are fluids designed to react or interact with formation rock and/or formation fluids in such manner that they reduce or eliminate the rate at which water is produced. It would be desirable to emplace such conformance chemicals at particular depth locations at or near the rock formations from which oil and/or gas is produced and then to thermally activate such conformance chemicals.
Downhole heating tools used to provide localized heat at perforation locations in producing oil wells. The heating tool increases the temperature of the produced oil which results in an increase in flow rate through the perforations due to a consequent decrease in viscosity of the produced oil.
Therefore, what is needed is a heating tool and a method for using a heating tool to reduce the curing time of a cement slurry or other sealant having a similar purpose and to heat conformance chemicals that are designed to be thermally activated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a downhole heating tool apparatus according to an embodiment of the present invention, shown in a vertical well bore.
FIG. 2 is a schematic view of a downhole heating tool apparatus according to an embodiment of the present invention, shown in a vertical well bore.
DETAILED DESCRIPTION
Cement and Sealant Applications
The method of this embodiment may be utilized to facilitate the cementing or other means of sealing casing to the bore hole wall in a well. Referring to FIG. 1 , a heating tool 12 according to an embodiment of the present invention is shown lowered into an underground, substantially vertically-extending, well bore 10 that penetrates a hydrocarbon producing subterranean formation 14 . A casing 16 extends from the ground surface 18 into the well bore 10 . As shown in FIG. 1 , an unset sealant such as a cement slurry 20 including a lead cement portion 22 and a tail cement portion 24 , is emplaced in the annulus 26 between the casing 16 and the formation 14 .
The heating tool 12 is connected by electric cable 28 to an electric power supply control station 30 . A suitable heating tool for this purpose is disclosed in U.S. Pat. No. 6,384,389 and U.S. Patent Publication No. 2002/0158064, the entire disclosures of which are hereby incorporated herein by reference.
Preferably, the heating tool 12 is lowered into the well bore 10 to a preferred location which, in the case of cement, is usually the tail cement portion 24 at the bottom 32 of the well bore 10 .
A variety of sealants can be used with the present embodiment, including cements, cements combined with latex, cements combined with resin and resins.
A cementing composition for sealing a subterranean zone penetrated by a well bore according to the present embodiment comprises a mixture of cementitious material (“cement”) and sufficient water to form a slurry. Suitable cements may include calcium, aluminum, silicon, oxygen, and/or sulfur, which set and harden by reaction with water (“hydraulic cements”). Such hydraulic cements include Portland cements, pozzolan cements, gypsum cements, aluminous cements, silica cements, and alkaline cements. Portland cements of the type defined and described in API Specification 10, 5 th Edition, Jul. 1, 1990, of the American Petroleum Institute (the entire disclosure of which is hereby incorporated as if reproduced in its entirety) are preferred. API Portland cements include Classes A, B, C, G, and H, of which API Class G is particularly preferred for the present embodiment. Another suitable cementitious material includes MgO cements. It is understood that the desired amount of cement is dependent on the volume required for the cementing operation. Alternatively, the cement can be microfine cement, such as is available from Dyckerhoff GmBH, Lengerich, Germany, under the trademark “MICRODUR RU.”
The water used to form a cement slurry is present in an amount sufficient to make the slurry pumpable for introduction down hole. The water used to form a cement slurry in the present embodiment can be fresh water, unsaturated salt solution, including brines and seawater, and saturated salt solution. Generally, any type of water can be used, provided that it does not contain an excess of compounds well known to those skilled in the art, that adversely affect properties of the cement slurry. The water is present in a range of about 25–98 mass percent of the cement slurry, and more preferably in an amount of about 38 mass percent of the cement slurry.
As noted above, the cement slurry may also include other materials to enhance the sealing capability of the cement slurry. Generally, such materials may include latexes and resins.
Suitable commercially available latexes, most of which are synthetic, include styrene butadiene copolymer latex and nitrile latex which are commercially available from Reichhold Chemicals, Inc., Research Triangle Park, N.C. under the trade name Tylac®, styrene butadiene acrylonitrile copolymer latex which is commercially available from Reichhold Chemicals, Inc., Research Triangle Park, N.C. under the trade name SNAP®, vinyl acetate homopolymer latex, vinyl acetate acrylate copolymer latex and -carboxylated styrene-butadiene copolymer latex which are commercially available from Reichhold Chemicals, Inc., Research Triangle Park, N.C. under the trade name Synthemul® and carboxylated acrylic copolymer latex which is commercially available from Reichhold Chemicals, Inc., Research Triangle Park, N.C. under the trade name Tychem®. Other suitable latexes include products that are available from Halliburton Energy Services, Inc. under the trade name Latex 2000®, which is a styrene-butadiene copolymer, and LAP1®, which is a partially hydrolyzed polyvinyl acetate isolated in the process of synthesizing latex, and other latex-based compounds.
Suitable commercially available resins, include epoxy resins that are condensation products of epichlorohydrin and bisphenol A which are commercially available from Shell Chemical Company under the trade name Epon Resin 828®, Epi-Rez-3510-W-60®, and Epi-Rez-5003-W-55®. Another suitable epoxy resin is commercially available from Halliburton Energy Services, Inc. under the trade name Stratalock®.
Other sealants for sealing a subterranean zone include epoxy resins with an attendant hardener plus filler additives such as silica flour. Another suitable sealant is commercially available from Halliburton Energy Services, Inc. under the trade name “Hydromite” which is a combination of gypsum cement and melamine resin. As will be understood, melamine resin has at its base the organic chemical compound, melamine, C 3 H 6 N 6 , which is a white crystalline material commonly used as a base for making plastics.
It will be understood that the latex and resin materials may be used alone or can be combined with a suitable cement material as mentioned above. The formulation of such sealants can be designed so that an increase in temperature accelerates the curing rate of such sealants. Such design of the sealants enables their curing rates to be accelerated by the use of a suitable heating tool as discussed above.
The heating tool 12 influences the temperature of the curing sealant at the tool location. An increase in the sealant temperature accelerates the curing or setting of the sealant. Heat from the heating tool 12 has been shown to radiate horizontally from the tool 12 but not vertically. Thus, precise placement of the heating tool 12 permits selective curing or setting of sealants with the ability to flush or produce back to the surface any uncured or unset sealant material. In the absence of the heating tool 12 of this embodiment, the temperature of the sealant is governed by the surrounding environment and the heat generated by the chemical reactions in the sealant.
Methods of this embodiment for sealing a subterranean zone include preparing a sealing composition as described herein, placing the sealing composition into the subterranean zone and heating the sealing composition to accelerate the setting of the sealing composition. According to preferred methods, the sealing composition is placed in the subterranean zone by pumping the sealing composition through a drill string and bit, circulating excess material out of the subterranean zone and removing the drill string and bit from the subterranean zone prior to heating the sealing composition. According to other preferred methods, a heating tool as described above is lowered into the subterranean zone to heat the sealing composition.
Conformance Applications
The method of this embodiment may be utilized to thermally activate conformance chemicals. According to this embodiment, conformance chemicals are first pumped into perforation locations through which it is intended that oil and/or gas is produced but which only produces water. The conformance chemicals are incorporated in conformance fluids so that at elevated temperatures, the viscosity or gel strength of such conformance fluids increases permanently and substantially, by orders of magnitude, for instance, thereby to prevent any further flow of water into the well through such perforations.
Referring to FIG. 2 , in conventional conformance treatments, a heating tool 112 according to an embodiment of the present invention is shown lowered into an underground, substantially vertically-extending, well bore 110 that penetrates a hydrocarbon producing subterranean formation 114 . Typically, production casing 116 extends from the ground surface 118 into the well bore 110 .
The heating tool 112 is connected by electric cable 120 to an electric power supply control station 122 . A suitable heating tool for this purpose is disclosed in U.S. Pat. No. 6,384,389 and U.S. Patent Publication No. 2002/0158064, the entire disclosures of which are hereby incorporated herein by reference.
According to this embodiment, conformance fluids 124 including conformance chemicals are pumped through the perforations 126 and into the permeable rock at prescribed depths, such depths being locations of unwanted water production 128 . The conformance chemicals are fluid when pumped in, and, in time, viscosify or increase in gel strength, or harden or solidify in some manner so as to prevent further flow of water 128 through perforations 126 . The reaction generally occurs in the region near and around the wellbore, and the reaction rate causing these rheological changes is influenced in part by the temperature of the surrounding environment. Generally, the higher the temperature, the faster the reaction.
Accordingly, the heating tool 112 is preferably lowered into the wellbore 110 to the location at which the conformance chemicals 124 are emplaced, after which the tool is energized. Preferably the conformance chemicals 124 are designed to activate or viscosify more rapidly at higher temperatures. The heating provided by the tool 112 thereby accelerates the process and reduces the time required to complete the conformance process by setting the conformance chemical product. Heat from the heating tool 112 has been shown to radiate horizontally from the tool 112 but not vertically. Thus, precise placement of the heating tool 112 permits selective setting of conformance chemicals with the ability to flush or produce back to the surface any unset material. In this context, the term “setting” means substantially increasing the viscosity or gel strength of fluids designed to become more viscous soon after one or both of progressing through casing perforations and permeating into rock pore space.
Conformance compositions are designed so that elevated temperatures increase the rate of acceleration of the viscosity of the conformance compositions so as to prevent unwanted cross-flow of rock formation fluids in which fluids from one rock formation channel through the wellbore outside the casing to another rock formation by virtue of a pressure difference between the two rock formations. An example of such undesired cross-flow of rock formation fluids is when water which has no commercial value channels in this manner to contaminate hydrocarbon-bearing zones and thereby be produced at the surface instead of the commercially valuable hydrocarbon.
Examples of such conformance chemicals include, but are not limited to: monomers, non-crosslinked polymers, resins, crosslinked polymers, fine-particle cement, conventional cement when the cavity to be filled is sufficiently large, for example, cavities having a volume of 4 or 5 cubic feet or more, silicates and MgO cement.
A suitable conformance monomer is acrylamide, and its attendant polymer polyacrylamide. Such monomers and polymers are commercially available from Halliburton Energy Services, Inc. and are employed in Halliburton's K-Trol Service,® in which they are pumped down a well into a water-bearing formation together with a suitable crosslinking agent such as sodium persulfate. The crosslinking reaction, which essentially turns the liquid mixture into a homogeneous semi-solid, takes place in situ, and temperature is a key determinant of the rate at which the crosslinking reaction takes place. An increase in temperature accelerates the reaction.
Another suitable monomer is a polymerizable hydroxy unsaturated carbonyl, which can be crosslinked by reaction with an alkali-metal persulfate. The polymerizable hydroxy unsaturated carbonyl and the alkali-metal persulfate are commercially available from Halliburton Energy Services, Inc. and are used in Halliburton's PermSeal® conformance service.
In addition to the monomers and polymers mentioned above, resins and similar chemicals may also be used to accomplish the same purpose. Suitable resins for this purpose include epoxy-resin products commercially available from Shell Chemical Company under the trade names Epon Resin 828®, Epi-Rez-3510-W-60®, and Epi-Rez-5003-W-55®, and an epoxy resin commercially available from Halliburton Energy Services, Inc. under the trade name Stratalock®.
A suitable fine-particle cement is commercially available from Halliburton Energy Services, Inc. under the trade name Micro-Matrix® cement. Micro-Matrix® cement has a typical particle size of less than one tenth that of conventional cement and can permeate rock pores of any diameter exceeding 50 microns. Those of ordinary skill in the art will understand that the conformance composition may also include other desirable components such as catalysts and activating agents to enhance the intended increase in viscosity.
Methods of this embodiment for performing conformance operations in a subterranean zone include preparing a conformance composition for inhibiting the production of water as described herein, placing the conformance composition into the subterranean zone adjacent a location of water production and heating the conformance composition to accelerate the setting or to increase the viscosity of the conformance composition.
Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims.
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Methods are described for providing localized heating in an oil well at precise depths to accomplish or expedite specific objectives. The methods involve the use of a heating tool which can be lowered into an oil well to apply heat at a precise depth to achieve a desired result. The specific objectives may include localized heating of a fresh cement slurry to accelerate curing, or localized heating of recently emplaced chemicals which are formulated to be thermally activated. One purpose of such chemicals is to viscosify or increase in gel strength after being pumped into an oil well production zone, in order to restrict the production of unwanted formation fluids such as water.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to the field of power window systems, and more particularly to devices and methods for maintaining a constant rate of speed at which an electric or other motor raises and lowers an automobile window.
2. Description of the Related Art
In the field of luxury automobiles, a customer's perception of quality is largely based on an automobile's level of refinement. One aspect of refinement centers on whether the operating speed of an automobile's power windows is smooth and consistent when the windows are raised and lowered. A problem common to all automobile power window systems is that the load on a window motor changes depending on whether the motor is pushing the window up or pulling it down. The force of gravity causes the load on the motor to be greater during upward travel than it is during downward travel. If this load inequality is not compensated for, the window will descend at a faster rate than it is able to ascend. This change in speed is much more noticeable with large, heavy pieces of glass such as those used in luxury vehicles.
A DC brush motor, which is commonly used to raise and lower automobile windows, converts electrical energy to mechanical energy by creating a magnetic field that pushes or pulls against permanent magnets on the motor case. The force on a current carrying conductor in a magnetic field is the product of the magnetic field strength and the current in the conductor. This relationship is described by the equation F=iL×B, where F is force, i is the magnitude of the current in the conductor, L is the direction current is traveling in the conductor, and B is magnetic field strength. The standard solution for overcoming the problem of unequal rates of power window ascent and descent has been to use pulse width modulation (PWM) to control the amount of current in a window motor's armature windings. By using PWM to vary the amount of voltage applied to a power window motor, the current flowing through the conductor may be varied and the speed-torque curve of the motor can be shifted up or down. Thus, by increasing the voltage applied to the motor during the upward travel of the window, and decreasing the voltage during the downward travel, the window's rates of ascent and descent can be matched.
It is desirable to have an alternative, mechanical solution to the problem of window motor load variation that does not require the additional electrical components necessary for employing PWM.
BRIEF SUMMARY OF THE INVENTION
It is the purpose of this invention to disclose devices and methods for varying the amount of torque applied to raising and lowering a power window in an automobile for equalizing that window's rates of ascent and descent without the use of additional electrical components. The invention is suitable for any window that has a vertical component of movement, thereby being affected by gravity in one direction but not in the opposite direction.
In accordance with the present invention, there is provided a power window assembly having a motor drivingly connected to a worm gear. The motor contains an armature that is rotatably driven by a magnetic field created by permanent magnets on the motor case. The worm of the worm gear is preferably a rigid, axial extension of the armature that communicates the rotational motion of the armature to the gear, which in turn drives the window up and down through conventional mechanisms.
In one embodiment of the invention, the armature is axially shifted in and out of the magnetic field in order to adjust the torque output of the motor. By shifting the armature partially out of alignment with the magnetic field, fewer of the armature's windings are exposed to the magnetic field, and the amount of torque generated by the motor drops accordingly. Axial displacement of the armature and the worm, which is preferably rigidly attached to the armature, is achieved by application of axial thrust forces to the armature and the worm that are generated by the gearing relationship between the worm and the gear.
When the window is being lowered, gravity assists the motor in pulling the window down, thereby obviating the need for maximum torque output. Therefore, the armature is shifted partially out of alignment with the magnetic field during downward travel. Conversely, when the window is being raised, and the load on the motor is increased relative to when the window is being lowered, due to the force of gravity resisting upward movement of the window, the armature preferably shifts into full alignment with the magnetic field to increase torque production. By varying the degree to which the armature is displaced when the window is lowered, a motor can be tailored to a particular window so that the window is raised and lowered at similar speeds.
In another embodiment of the invention, the torque provided for raising and lowering the window is varied by using a gear having an asymmetrical tooth profile. By forming the gear teeth with one side of each tooth having a greater pitch than the opposite side of the tooth, the efficiency of the gear varies depending on whether it is rotating clockwise or counterclockwise.
In order to compensate for the force of gravity, the gear is preferably oriented within the power window assembly to transmit torque more efficiently when rotating to raise the window and less efficiently when rotating to lower the window. By varying the tooth profile, a gear can be tailored to a particular window in order that the window ascends and descends at similar speeds.
In yet another embodiment of the invention, the torque provided for raising and lowering the window is varied by the incorporation of a worm having an asymmetrical thread profile. By forming the threads of the worm with one side of each thread having a greater pitch than the opposite side of the thread, the efficiency of the worm varies depending on whether it is rotating clockwise or counterclockwise. Similar to the asymmetrical tooth embodiment described above, the thread profile can be tailored to a particular window in order that the window ascends and descends at similar speeds.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 a is a schematic side view illustrating an embodiment of the present invention when operating to raise a window.
FIG. 1 b is a schematic side view illustrating the embodiment of the present invention shown in FIG. 1 a when operating to lower a window.
FIG. 2 a is a schematic side view illustrating an alternative embodiment of the present invention when operating to raise a window.
FIG. 2 b is a schematic side view illustrating the alternative embodiment of the present invention shown in FIG. 2 a when operating to lower a window.
FIG. 3 a is an exploded side view illustrating the engagement between the gear and the worm of the alternative embodiment of the present invention shown in FIG. 2 a when operating to raise a window.
FIG. 3 b is an exploded side view illustrating the engagement between the gear and the worm of the alternative embodiment of the present invention shown in FIG. 2 b when operating to lower a window.
FIG. 4 a is an exploded side view illustrating the engagement between the gear and the worm of an alternative embodiment of the present invention when operating to raise a window.
FIG. 4 b is an exploded side view illustrating the engagement between the gear and the worm of an alternative embodiment of the present invention when operating to lower a window.
In describing the preferred embodiment of the invention which is illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific term so selected and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. For example, the word connected or terms similar thereto are often used. They are not limited to direct connection, but include connection through other elements where such connection is recognized as being equivalent by those skilled in the art.
DETAILED DESCRIPTION OF THE INVENTION
The embodiment of the invention shown in FIGS. 1 a and 1 b is incorporated into an automobile electric window motor assembly, which is preferably a dc brush motor containing an armature 2 that rotates within a magnetic field created by permanent magnets 4 on the motor case. The armature 2 is rigidly connected to the worm 6 of a worm gear 8 . Because of the gearing relationship between the armature 2 , the worm 6 and the cooperating gear 10 , this type of assembly generates an axial thrust force (along the axis of the arrow of FIG. 1 a ) on the worm 6 and the armature 2 , causing them to push against the motor case when rotating in one direction, and to push against the gear housing when rotating in the opposite direction, as shown in FIG. 1 b.
The critical feature of the embodiment of the invention shown in FIGS. 1 a and 1 b is that the armature 2 and the worm 6 are free to travel a short distance back and forth along a line defined by their shared axis. This can result from a gap being formed between the components of the motor, or a spring structure permitting such axial movement. By allowing the armature 2 and the worm 6 to shift several millimeters (in one example) along that line, the armature windings 12 can be displaced relative to the permanent magnets 4 , thereby altering the alignment between the armature windings 12 and the magnetic field of the permanent magnets 4 . This change in alignment results in a change in torque, as described below.
When a car's power window is being lowered, the amount of torque produced by the motor must be less than when it is being raised in order for the window's rates of ascent and descent to match. Referring to FIG. 1 b , a reduction in torque is achieved by allowing the axial thrust force discussed above to move the armature 2 , and, thereby, shift the armature windings 12 partially outside of the magnetic field when the window is being lowered as shown by the arrow in FIG. 1 b . The amount of shift is exaggerated in FIG. 1 b for illustrative purposes. This reduction in alignment between the windings 12 and the field increases the reluctance in the motor's magnetic circuit, resulting in decreased torque production and less force pulling the window down than the motor would generate with the windings 12 fully aligned with the magnetic field (as in FIG. 1 a ). By decreasing the force pulling the window down to the desired degree, the rate of window descent can be matched to the rate of ascent.
Referring back to FIG. 1 a , when the motor is driven in the “up” direction, the armature 2 is thrust in the opposite axial direction, thereby shifting the armature windings 12 into full alignment with the magnetic field. Greater exposure of the windings 12 to the field results in an increase in the motor's torque output. The result is that the window is more forcefully pushed upwardly in order to overcome the downward force of gravity. By varying the degree to which the armature 2 is displaced relative to the permanent magnets 4 , a motor can be tailored to suit a specific load profile. Generally, for the same motor, the heavier a particular window is, the greater the degree of armature 2 displacement necessary to match the rates of descent and ascent for that window.
In an alternative embodiment of the invention, the amount of torque applied to raising and lowering a window is varied by modifying the gearing arrangement in the power window assembly. Referring to FIGS. 2 a - 3 b , the profile of each tooth 20 of the gear 22 is asymmetrical in the manner of a conventional asymmetrical gear. That is, the pitch of one side 24 of each tooth 20 is greater with respect to the gear wheel 26 than the pitch of the opposite side 28 of each tooth 20 . The horizontal and vertical components of the force imparted to the gear 22 by the worm 30 thus vary depending upon the direction in which the worm 30 is driving the gear 22 . This is best illustrated in the exploded views of the threads 32 of the worm 30 and the teeth 20 of the gear 22 shown in FIGS. 3 a and 3 b , wherein the lengths of the vectors V and H represent the relative magnitudes of the vertical and horizontal forces imparted by the threads 32 to the teeth 20 . Horizontal and vertical refer to the orientation in the figures as shown.
In FIGS. 2 a and 3 a , the gear 22 and the worm 30 are rotating in the clockwise direction, when viewed from the front and the right end, respectively, and the worm 30 is engaging the sides 28 of teeth 20 that have the lesser pitch. The horizontal component of the force imparted to the gear 22 is thus greater than the vertical component. In FIGS. 2 b and 3 b , the worm 30 and the gear 22 are rotating in the counterclockwise direction, when viewed from the front and the right end, respectively, and the worm 30 is engaging the sides 24 of teeth 20 that have the greater pitch. The horizontal component of the force imparted to the gear is thus lesser than the vertical component.
The result of this disparity in pitch is that the efficiency of the gear 22 is greater when the worm 30 turns clockwise (as shown in FIGS. 2 a and 3 a ) as compared to when it turns counterclockwise (as shown in FIGS. 2 b and 3 b ). This approach does not change the fundamental torque production of the armature (as in the embodiment of the invention described above), but changes the efficiency of torque transferred through the gearing.
Although a dc brush motor has been described and shown as the driving means for the gear 22 , those skilled in the art will appreciate that all other suitable driving means, such as various other rotary motors, can alternatively be used to drive the asymmetrical gear 22 while still achieving the same directionally-dependent torque efficiency described.
Referring to the exploded views of the gear 40 and the worm 42 shown in FIGS. 4 a and 4 b , it is contemplated that the teeth 44 of the gear 40 may alternatively be symmetrical (i.e., having the same pitch on both sides), and that the threads 46 of the worm 42 may instead be asymmetrical, thus achieving the same directionally-dependant efficiency relationship described above. In another alternative, an embodiment of the worm gear is contemplated wherein both the gear teeth and the threads of the worm are asymmetrical (not pictured).
Referring back to FIGS. 2 a and 2 b , the gear 22 is oriented deliberately within the power window assembly in order that the worm 30 engages the sides 28 of the gear teeth 20 having a lesser pitch when the worm 30 rotates to raise the window, and engages the sides 24 of the teeth 20 having a greater pitch when the worm 30 rotates to lower the window. Therefore, the gear 22 will receive torque from its cooperating worm 30 more efficiently when the window is being raised and less efficiently when it is being lowered. The additional torque efficiency provided during upward travel of the window compensates for the additional load placed on the motor due to gravity. By tailoring the gear tooth profile to a specific window, the gear 22 is able to transfer the desired torque to raise and lower the window at the same rate despite the different motor load. Generally, the heavier the window, the greater the disparity in pitch that will be necessary.
It is contemplated that the embodiments of the invention described above may be combined to form alternative, hybrid embodiments of the invention that incorporate features that have heretofore been discussed only in separate embodiments. For example, an embodiment is contemplated that incorporates variable armature alignment as well as an asymmetrical gear tooth profile. Alternatively, the window motor assembly can incorporate variable armature alignment as well as an asymmetrical thread profile on the worm.
This detailed description in connection with the drawings is intended principally as a description of the presently preferred embodiments of the invention, and is not intended to represent the only form in which the present invention may be constructed or utilized. The description sets forth the designs, functions, means, and methods of implementing the invention in connection with the illustrated embodiments. It is to be understood, however, that the same or equivalent functions and features may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention and that various modifications may be adopted without departing from the invention or scope of the following claims.
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A device and method for matching the rates of speed at which an electric motor that is drivingly connected to a worm gear raises and lowers a window in an automobile power window assembly. By axially displacing the motor's armature, and/or by varying the thread and tooth profiles of the worm and the gear, the amount of torque produced by the motor and transmitted through the worm gear can be altered. In order to compensate for the effect of gravity on the motor load and on the window's speed of ascent and descent, more torque is provided when the window is being raised and less torque is provided when the window is being lowered.
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FIELD OF THE INVENTION
[0001] The present invention relates to a video monitoring field, and more particularly, to a target tracking method and system for an intelligent tracking fast-speed dome
BACKGROUND OF THE INVENTION
[0002] A fast-speed dome (also called a spherical camera) is referred to as a high speed dome camera, and is an important tracking front in a tracking system. It can be used in a high-density and complicated tracking scenario. The intelligent tracking fast-speed dome includes a positioning system, a communication system and a camera system, and can automatically track a moving object in a scenario. The positioning system refers to a rotating part driven by a motor. The communication system refers to a part of controlling the motor and processing the image signal. The camera system refers to an integrated engine. The systems can perform transverse connections through a main-control CPU and a battery. The battery performs power supply for each system, so all functions can work properly through the main-control CPU.
[0003] The fast-speed dome usually adopts a precise differential stepper motor to implement fast and accurate rotating and positioning. These actions can be implemented under the control of the CPU command. The method of writing the images and functions of a camera into the CPU of the fast-speed dome can make the image being transmitted at the same time of controlling the positioning system, as well as the functions of white balance, shutter, aperture, zoom and target tracking.
[0004] At present, the speed dome can automatically perform action analysis and alarm tracking. The processes can be automatically implemented through writing program that is executed by the CPU. When multiple targets occur in an image, with the standard of current intelligent tracking fast-speed dome, the target who triggers an alarm firstly will be tracked.
SUMMARY OF THE INVENTION
[0005] A target tracking method for an intelligent tracking fast-speed dome, an intelligent tracking fast-speed dome and a target tracking system for an intelligent tracking fast-speed dome are provided according to embodiments of the present invention which implements the function of switching a tracking target in a process of tracking the target.
[0006] A target tracking method for an intelligent tracking fast-speed dome includes:
[0007] matching a location coordinate of a newly-selected target in a collected tracking image when receiving the location coordinate of the newly-selected target in the tracking image in a process of tracking a target, setting a target corresponding to the location coordinate of the newly-selected target as a current target, extracting a characteristic of the current target;
[0008] tracking the current target according to the characteristic of the current target, updating the location coordinate of the current target in the tracking image in real time;
[0009] in real time transforming the updated location coordinate of the current target to a Pan (P) value, a Tilt (T) value and a Zoom (Z) value recognizable for a speed dome; and in real time adjusting a magnification according to the Z value, in real time controlling rotation of the speed dome according to the P value and the T value.
[0010] The method further includes:
[0011] selecting a monitoring scenario;
[0012] calibrating a magnification coefficient of the speed dome.
[0013] In the method, a process of calibrating the magnification coefficient of the speed dome includes:
[0014] setting the ground level as a monitoring field;
[0015] wherein the magnification coefficient of the speed dome is Z 0 ×sin(T 0 ) (Z 0 is the Z value when a distance between a reference target and the speed dome is a known distance D 0 , and T 0 is the T value when the distance between the reference target and the speed dome is the known distance D 0 .
[0016] The method further includes:
[0017] transforming the location coordinate of the newly-selected target to a normalized coordinate, wherein the normalized coordinate a coordinate value after a normalization processing corresponding to a length and a width of the image is performed.
[0018] In the method, a process of in real time transforming the updated location coordinate of the current target to the P value, the T value and the Z value recognizable for a speed dome includes:
[0019] transforming the updated location coordinate of the current target to a spherical coordinate taking the speed dome as a center;
[0020] obtaining the P value and the T value of the spherical coordinate;
[0021] obtaining the Z value according to location information of the current target and the magnification coefficient of the speed dome.
[0022] In the method, the P value and the T value are obtained through a method as follows according to the spherical coordinate.
[0000] P =arctan( v/u )
[0000] T =arctan( w /√{square root over ( u 2 +v 2 )})
[0023] wherein the spherical coordinate of the current target is (u, v, w), the spherical coordinate taking the speed dome as the center.
[0024] In the method, the Z value is obtained according to location information of the current target and the magnification coefficient of the speed dome through a method as follows:
[0000] Z=Z ref /sin( T 1 );
[0025] wherein sin(T 1 ) is an adjustment function of the dynamic magnification coefficient of the location information of the current target,
[0026] Z ref is the magnification coefficient of the speed dome, T 1 is information of an angle between the location of the current target and a camera lens of the speed dome.
[0027] In the method, a process of controlling the rotation of the speed dome according to the P value and the T value includes:
[0028] determining a value and a direction of a speed of the current target through a method as follows:
[0000]
V
pan
=
Δ
P
Δ
t
=
P
new
-
P
cur
Δ
t
V
tilt
=
Δ
T
Δ
t
=
T
new
-
T
cur
Δ
t
[0029] wherein V pan is a moving speed along a horizontal rotation direction in a spherical coordinate system taking the speed dome as the center, V tilt is a moving speed along a vertical rotation direction in the spherical coordinate system taking the speed dome as the center;
[0030] P new and T new respectively a new P value and a new T value in the spherical coordinate system taking the speed dome as the center, P cur , T cur is a current P value and a current T value of the speed dome, Δt is the time of processing a frame.
[0031] controlling the speed dome to be accelerated or decelerated according to the value and the direction of the speed of the current target.
[0032] In the method, a process of controlling the speed dome to be accelerated or decelerated according to the value and the direction of the speed of the current target includes:
[0033] step a, determining whether a moving direction of the current tracking target is same as a current rotation direction of the speed dome; when the moving direction of the current tracking target is same as the current rotation direction of the speed dome, performing step b, otherwise, performing step f;
[0034] step b, determining whether the moving speed of the current tracking target is more than a current rotation speed of the speed dome, when the moving speed of the current tracking target is more than the current rotation speed of the speed dome, performing step c, otherwise, performing step d;
[0035] step c, accelerating the current rotation speed of the speed dome, and performing step d;
[0036] step d, determining whether the moving speed of the current tracking target is equal to the current rotation speed of the speed dome, when the moving speed of the current tracking target is equal to the current rotation speed of the speed dome, performing step i, otherwise, performing step e;
[0037] step e, decelerating the current rotation speed of the speed dome, and performing step d;
[0038] step f, decelerating the current moving speed of the speed dome, and performing step g;
[0039] step g, determining whether the current rotation speed is equal to zero, when the current rotation speed is equal to zero, performing step h, otherwise performing step f;
[0040] step h, changing the rotation direction of the speed dome, and performing step b;
[0041] step i, tracking the current target with the current rotation speed.
[0042] An intelligent tracking fast-speed dome includes an image collecting module, a central processor, a driven circuit and an adjustment module,
[0043] the central processor is to match a location coordinate of a newly-selected target in a tracking image collected by the image collecting module when receiving the location coordinate of the newly-selected target in the tracking image in a process of tracking a target, set a target corresponding to the location coordinate of the newly-selected target as a current target, extract a characteristic of the current target, track the current target according to the characteristic of the current target, in real time update the location coordinate of the current target in the tracking image, in real time transform the updated location coordinate of the current target to a Pan (P) value, a Tilt (T) value and a Zoom (Z) value recognizable for a speed dome, output to the adjustment module the P value, the T value and the Z value via the driven circuit; and
[0044] the adjustment module is to in real time adjust a magnification according to the Z value, in real time control rotation of the speed dome according to the P value and the T value.
[0045] A system for an intelligent tracking fast-speed dome includes an intelligent tracking fast-speed dome and a host computer,
[0046] the host computer is to transmit a location coordinate of a newly-selected target in a tracking image to the intelligent tracking fast-speed dome in a process of tracking a target;
[0047] the intelligent tracking fast-speed dome comprises an image collecting module, a central processor, a driven circuit and an adjustment module, wherein
[0048] the central processor is to match a location coordinate of a newly-selected target in a tracking image collected by the image collecting module when receiving the location coordinate of the newly-selected target in the tracking image in a process of tracking a target, set a target corresponding to the location coordinate of the newly-selected target as a current target, extract a characteristic of the current target, track the current target according to the characteristic of the current target, in real time update the location coordinate of the current target in the tracking image, in real time transform the updated location coordinate of the current target to a Pan (P) value, a Tilt (T) value and a Zoom (Z) value recognizable for a speed dome, output to the adjustment module the P value, the T value and the Z value via the driven circuit; and
[0049] the adjustment module is to in real time adjust a magnification according to the Z value, in real time control rotation of the speed dome according to the P value and the T value.
[0050] It can be seen from the above that, according to the target tracking method for an intelligent tracking fast-speed dome, the intelligent tracking fast-speed dome and the target tracking system for an intelligent tracking fast-speed dome are provided according to embodiments of the present invention, when multiple targets occur in a scenario, a monitoring person can select a target concerned by the monitoring person to perform a selective tracking process and to solve a problem in the scenario that the multiple targets occur, the tracking target is not the concerned target, the concerned target is missed, and a monitoring purpose cannot be achieved. At the same time, in a tracking process of the speed dome, since the scenario is complicated and an image analysis technology is limited, a condition may occur that the target is missed or is blocked by another target. According to the method of the present invention, the target can be re-selected. In addition, in a scenario that a large target is tracked, e.g., a large truck, in a conventional method, a target for image analysis may be on a top of the truck or another part, and may not be in a concerned license plate location, which may cause that in the tracking process, the license plate cannot be seen. According to the method, the speed dome and the system for the speed dome of the present invention, the license plate part can be selected to be tracked.
BRIEF DESCRIPTION OF DRAWINGS
[0051] FIG. 1 is a schematic diagram illustrating a structure of a system for implementing a target tracking method and system for an intelligent tracking fast-speed dome according to an embodiment of the present invention;
[0052] FIG. 2 is a flowchart illustrating a target tracking method and system for an intelligent tracking fast-speed dome according to an embodiment of the present invention;
[0053] FIG. 3 is a schematic diagram illustrating a module of setting a magnification coefficient of a speed dome according to an embodiment of the present invention;
[0054] FIG. 4 is a schematic diagram illustrating a normalization processing for a selected target according to an embodiment of the present invention;
[0055] FIG. 5 is a schematic diagram illustrating viewing angles corresponding to the points of different three-dimensional sharps displayed in a same location in an image with a same zoom according to an embodiment of the present invention;
[0056] FIG. 6 is a schematic diagram illustrating a module used for transforming an image coordinate of a target to a P value, a V value and a Z value according to an embodiment of the present invention;
[0057] FIG. 7 is a schematic diagram illustrating a module for transforming a location coordinate of a current tracking target in an image to a spherical coordinate which is taking a speed dome as a center according to an embodiment of the present invention;
[0058] FIG. 8 is a flowchart illustrating a process of controlling a speed dome to perform smooth rotation according to an embodiment of the present invention;
DETAILED DESCRIPTION OF THE INVENTION
[0059] In order to make the object, technical solution and merits of the present invention clearer, the present invention will be illustrated in detail hereinafter with reference to the accompanying drawings and specific examples.
[0060] The present invention applies to a system for an intelligent tracking fast-speed dome as shown in FIG. 1 . The system includes an intelligent tracking fast-speed dome 1 and a host computer 2 . The host computer 2 (e.g., a computer used to perform monitoring) is mainly used to select a target, and transmit a location coordinate of the selected target to the intelligent tracking fast-speed dome 1 . The host computer 2 may select the target to be tracked in a tracking image in a monitoring process. The intelligent tracking fast-speed dome 1 is to set the target selected by the host computer 2 as a tracking target. In the tracking process, when the host computer 2 selects a new target, the tracking target is changed, i.e., the newly-selected target is tracked. The intelligent tracking fast-speed dome 1 include a central processing 11 , an image collecting module 12 , a zoom motor 13 , a horizontal rotation motor 14 and a vertical rotation motor 15 . The image collecting module 12 and the zoom motor 13 locates in a camera system of the speed dome, i.e., the integrated engine. The image collecting module 12 is to collect an image. The zoom motor 13 is to perform zoom for the collected image. The horizontal rotation motor 14 and the vertical rotation motor 15 locate in a pan-and-tilt system, and are to adjust a shooting angle of the camera system in the speed dome. The intelligent tracking fast-speed dome 1 may further include a driven circuit 16 to drive the zoom motor 13 , the horizontal rotation motor 14 and the vertical rotation motor 15 . The central processor 11 is mainly to process and output the image collected by the camera system (through the image collecting module 12 ), and control the zoom motor 13 , the horizontal rotation motor 14 and the vertical rotation motor 15 according to the collected tracking image, so that the speed dome can track the target shot by the speed dome. In an example, the central processor 11 includes an Advanced RISC Machines (ARM) processor 111 and a digital signal processor (DSP) 112 . In an example, the ARM processor 111 is to receive a location coordinate of the selected target from the host computer 2 , and perform a normalization processing. In particular, according to the location coordinate of the current tracking target in the tracking image collected by the image collecting module provided by the DSP 112 , a P value, a Tilt (T) value and a Z value are generated. The ARM processor 111 controls the horizontal rotation motor 14 and the vertical rotation motor 15 and the zoom motor 13 , so that according to movement of the current tracking target, the speed dome adjust a shooting direction in order to track and shoot the current tracking target. The DSP 112 is to compare a normalized coordinate of the selected target with the tracking image collected by the collecting module 12 in order to determine the current tracking target that is same with the selected target, and is further to in real time transmit the location coordinate of the current tracking target in the tracking image collected by the image collecting module to the ARM processing 111 . The P value, the T value and the Z value are signals that can be recognized by the speed dome. The P value is a horizontal rotation value of the speed dome. The T value is a vertical rotation value of the speed dome. The Z value is an magnification of the speed dome. In the present invention, the speed dome can also be called as a PTZ (Pan-Tilt-Zoom) camera in the art. A structure and function modules of the speed dome can refer as to the prior art, which is not described repeatedly herein.
[0061] A target tracking method for an intelligent tracking fast-speed dome according to the present invention includes: setting a target selected by a host computer as a tracking target to perform tracking; changing the tracking target to perform the tracking according to the new target selected by the host computer. In particular, as shown in FIG. 2 , the process of tracking the current tracking target includes procedures as follows.
[0062] At block 1 , it is determined that whether a location coordinate of a new selected target in a collected tracking image is received. If the location coordinate is received, a procedure at block 2 is performed. Otherwise, a procedure at block 3 is performed.
[0063] At block 2 , according to the location coordinate of the new selected target in the collected tracking image, location coordinate matching is performed for the location coordinate of the new selected target in the tracking image collected by the image collecting module. A target in the tracking image corresponding to the location coordinate of the newly-selected target in the tracking image is set as the current tracking target, and a characteristic of the current tracking target is extracted, and a procedure at block 3 is performed.
[0064] At block 3 , according to the characteristic of the current tracking target, the current target is tracked, the location coordinate of the current tracking target in the tracking image collected by the image collecting module is updated in real time, and a procedure at block 4 is performed.
[0065] At block 4 , the consecutively-updated location coordinate of the current tracking target in the tracking image collected by the image collecting module is in real time transformed to a P (horizontal rotation) value, T (vertical rotation) value, and Z (magnification) value, and a procedure at block 5 is performed.
[0066] At block 5 , according to the Z value, the magnification of the speed dome is adjusted in real time, according to the P value and the T value, the rotation of the speed dome is controlled in real time, and a procedure at block 1 .
[0067] Further, before the intelligent tracking fast-speed dome tracks the target, a monitoring scenario and speed dome related parameters may be configured, which includes procedures as follows.
[0068] In step I, the monitoring scenario is selected.
[0069] In step II, a magnification coefficient of the speed dome is calibrated.
[0070] In addition, at block 2 , in a process of matching the location coordinate in the collected tracking image, a normalization operation may be included, i.e., the location coordinate of the selected target is transformed to the normalized coordinate of the selected target.
[0071] A target tracking method for an intelligent tracking fast-speed dome is illustrated accompanying with FIG. 1 and FIG. 2 .
[0072] In step I, the monitoring scenario is selected.
[0073] The central processor 11 may perform a process of monitoring a suspicious target in a designated monitoring scenario, i.e., in an area in which the intelligent tracking fast-speed dome performs monitoring, e.g., a monitoring area such as a bank, a station. When the monitoring scenario is selected, a focal distance may be adjusted for the intelligent tracking fast-speed dome, so that the intelligent tracking fast-speed dome can monitor the suspicious target in a large area.
[0074] In step II, a magnification coefficient of the speed dome is calibrated.
[0075] In a tracking stage, since the tracking target moves, a distance between the tracking target and the intelligent tracking fast-speed dome may be changed. Thus, the central processor 11 in the intelligent tracking fast-speed dome may control the magnification. When the tracking target is far away the speed dome, the magnification of the intelligent tracking fast-speed dome is increased. When the tracking target is close to the speed dome, the magnification of the intelligent tracking fast-speed dome is decreased. Thus, it is ensured that the tracking target can always locate in a scenario area shot by the intelligent tracking fast-speed dome. In step II, the magnification coefficient of the speed dome is calibrated according to a method as follows.
[0076] It is assumed that the visual range of the intelligent tracking fast-speed dome is a ground level. A simple module in FIG. 3 is used. Line segments BC and BD represent the ground level. A dot A represents an installation location of the intelligent tracking fast-speed dome. A line segment AB is vertical with the line segment BC. A length of the AB is a height H of the intelligent tracking fast-speed dome from a ground. Dots C and D respectively represent two locations of a reference target when the magnification coefficient of the speed dome is calibrated. A length of the AC D 1 is a distance between the reference target and the intelligent tracking fast-speed dome when the reference target locates in a dot C. It is assumed that D 1 is a distance to be obtained. ∠ACB is an angle between the line segment AC from the reference target and the intelligent tracking fast-speed dome and the ground level when the reference target locates at the dot C. A ∠ACB value is T 1 . A length of the AD D 0 is a distance between the reference target and the intelligent tracking fast-speed dome when the reference target locates in a dot D. It is assumed that D 0 is a known distance. ∠ADB is an angle between the line segment AD from the reference target and the intelligent tracking fast-speed dome and the ground level when the reference target locates at the dot D. A ∠ADB value is T 0 . According to a geometric relation, a known parameter of the speed dome and a control way, T 1 and T 0 are the T value of the intelligent tracking fast-speed dome, i.e., the Tilt value of the intelligent tracking fast-speed dome. Accordingly, when the reference target locates at the doc C (i.e., it corresponds to the distance D 1 to be obtained), the magnification Z value of the intelligent tracking fast-speed dome is a magnification Z 1 to be obtained. When the reference target locates at the dot D (i.e., it corresponds to the known distance D 0 ), the magnification Z value of the intelligent tracking fast-speed dome is a known magnification Z 0 . According to geometry knowledge, when the reference target respectively locates at the dot C and dot D, a relation between the magnification Z 1 to be obtained and the known magnification Z 0 is:
[0000]
Z
1
Z
0
=
D
1
D
0
=
H
sin
(
T
1
)
H
sin
(
T
0
)
=
sin
(
T
0
)
sin
(
T
1
)
(
1
′
)
[0077] It is obtained that
[0000]
Z
1
=
Z
0
×
sin
(
T
0
)
sin
(
T
1
)
(
1
)
[0078] It can be seen from the formula (1) that when Z 0 , T 0 and T 1 ; are known, Z 1 may be dynamically calculated.
[0079] The magnification coefficient of the speed dome is Z 0 ×sin(T 0 ). The process of calibrating the magnification coefficient of the speed dome includes determining the Z 0 and T 0 . A suitable size of the reference target can locate in a viewing center by adjusting the location of the intelligent tracking fast-speed dome (mainly the T value of the speed dome) and the focal distance to a suitable magnification (the Z value). The T value and the Z value obtained from the intelligent tracking fast-speed dome are respectively taken as T 0 and Z 0 . A value of Z 0 ×sin(T 0 ) is calculated. A process of calibrating the magnification coefficient of the speed dome finishes. As shown in FIG. 3 , when the reference target locates at the dot D, the T value and the Z value of the intelligent tracking fast-speed dome are adjusted so that the reference target with a suitable size locates in the viewing center. At this time, the T value and the Z value of the intelligent tracking fast-speed dome are respectively taken as T 0 and Z 0 . Z 0 ×sin(T 0 ) is calculated, which is the magnification coefficient of the speed dome.
[0080] Afterwards, in a process of tracking the target, when the T value (i.e., the vertical rotation value of the intelligent tracking fast-speed dome, or a shooting elevation angle (a depression angle) of the intelligent tracking fast-speed dome, or a rotation angle of the intelligent tracking fast-speed dome along a direction vertical with the ground level) is changed, the T value and the Z value may be dynamically obtained through the formula (1) in order to dynamically adjust the Z value.
[0081] At block 1 , it is determined that whether a location coordinate of a newly-selected target in a collected tracking image is received. If the location coordinate is received, a procedure at block 2 is performed. Otherwise, a procedure at block 3 is performed.
[0082] In the monitoring process, the host computer 2 is to select a concerned target in a monitored scenario image, focus the target after the target is selected, and transmit a location coordinate (x, y) of the target in the monitored scenario image to the intelligent tracking fast-speed dome 1 . In the intelligent tracking fast-speed dome 1 , the central processor 11 is to receive the location coordinate (x, y) of the target from the host computer 2 . In an example, the ARM processor 111 in the central processor 11 is to receive the location coordinate (x, y) of the selected target from the host computer 2 .
[0083] The location coordinate of the newly-selected target is transformed to a normalized coordinate. Since different cameras may have different resolution ratios and a same camera may supports multiple resolution ratios, coordinate values of the selected target in a same location may be different in different resolution ratios. In order to solve the problem, a normalization processing may be used. In different resolution ratios, after the normalization processing is performed for a target coordinate, target locations may be same when the image is analyzed.
[0084] At block 2 , According to the location coordinate of the newly-selected target in the collected tracking image, location coordinate matching is performed for the location coordinate of the newly-selected target in the tracking image collected by the image collecting module. A target that is in the tracking image and corresponds to the location coordinate of the newly-selected target in the tracking image is set as the current tracking target, and a characteristic of the current tracking target is extracted.
[0085] At this block, in a process of matching the location coordinate in the collected tracking image, a normalization operation may further included, i.e., transforming the location coordinate of the selected target to the normalization coordinate. Procedures as follows are included at this block.
[0086] The normalization processing may be implemented through the central processor 11 , e.g., the ARM processor 111 . The ARM processor 111 transforms the received location coordinate (x, y) of the target to the normalization coordinate (x′, y′), and transmits the normalization coordinate (x′, y′) of the selected target to the DSP 112 to perform a subsequent processing. As shown in FIG. 4 , the normalization coordinate (x′, y′) of the selected target is a coordinate value obtained after the normalization processing is performed according to a length L and a width H of the image. It is assumed that the length of the image area is L, the width of the image area is H, and an actual coordinate of the selected target in the image is (x, y). After the normalization process is performed, the obtained normalization coordinate of the selected target (x′, y′) relative to a 255×255 plane as shown in FIG. 4 is:
[0000]
x
′
=
255
×
x
L
(
2
)
y
′
=
255
×
y
L
(
3
)
[0087] For example, the DSP 112 receives the location coordinate of the newly-selected target from the ARM processor 111 , and performs positioning in the tracking image collected by the image collection module 12 according to the location coordinate of the newly-selected target, so that the current tracking target is determined in the tracking image collected by the image collection module 12 , which is same as the selected target, i.e., the target corresponding to the location coordinate of the newly-selected target in the tracking image collected by the image collected module 12 may be determined as the current tracking target. Afterwards, the DSP 112 extracts the characteristic of the current tracking target, and may further determine whether the current tracking target is same as the newly-selected target.
[0088] At block 3 , according to the characteristic of the current tracking target, the current target is tracked, the location coordinate of the current tracking target in the tracking image collected by the image collecting module is updated in real time.
[0089] At this block, according to the characteristic of the current tracking target, the central processor 11 in real time updates the location coordinate of the current tracking target in the tracking image collected by the image collection module 12 . For example, according to the characteristic of the current tracking target, the DSP 112 in real time updates the location coordinate of the current tracking target in the tracking image collected by the image collection module 12 . For example, the DSP 112 in real time updates the location coordinate of the target in the image in a frame ratio 25 frames/s, and transmits the updated location coordinate to the ARM processor 111 .
[0090] At block 4 , the location coordinate of the consecutively-updated current tracking target in the tracking image collected by the image collecting module is transformed in real time to a P (horizontal rotation) value, T (vertical rotation) value, and Z (magnification) value.
[0091] For tracking image information collected by the image collection module, there is a relation that as shown in FIG. 5 , viewing angles corresponding to a dot displayed in a same location of the image in a same zoom are basically same no matter which three-dimensional sharps scenes in the image are.
[0092] In FIG. 5 , an object A and an object B have different three-dimensional sharps. Locations of a dot P 1 and a dot P 2 can be considered as a same location in the shot image, and correspond to certain viewing angles, which are similar as these of a dot P 3 and a dot P 4 . Thus, there is a relation between a dot in the image and a certain viewing angle of a camera lens (or the image collection module).
[0093] The relation may be transformed to detail pan-and-tilt rotation. A geometric model as shown in FIG. 6 may be considered. The camera lens locates in a center dot O of a half-sphere, OC is an optical axis of the camera lens. According to the relation above, a middle plane represents an object. The plane may be a tangent plane where the dot C locates, and may be equivalent as a plane on which a mouse clicks in the tracking image. The tracking image collected by the image collection module is represented with a rectangle area. Thus, according to different azimuthal angles where the integrated engine locates, locations of the rectangle area in a space may be different accordingly. When the mouse clicks at the dot P in the rectangle area, latitude and longitude of the line segment OP corresponding to half-sphere may be calculated according to solid geometry. A direction angle of the optical axis is adjusted to the direction through pan-and-tilt rotation, the dot P naturally locates in a center of the video image. A calculation method in the present invention is illustration as follows.
[0094] The horizontal direction and the vertical direction of the image are respectively divided into 255 equal parts (i.e., divided into the 255 equal parts along a x direction and a y direction in a xy plane as shown in FIG. 6 ), the dot C locates in the center of the image, the coordinate of the dot C is (centerX, centerY). Thus, the coordinate of the dot P is:
[0000] x =(center X− 255/2)/ratio
[0000] y =(center Y− 255/2)
[0095] wherein ratio=tan(a)/tan(b)
[0096] a is a vertical viewing half-angle in a minimum magnification (doubled) of the engine, b is a horizontal viewing half-angle in a minimum magnification (doubled) of the engine.
[0097] The spherical radius is:
[0000] R=OC= 255/2/tan α
[0098] wherein α is a vertical viewing half-angle in a certain magnification;
[0099] or the spherical radius is approximated by
[0000] R=OC =(255/2/tan β)×zoom
[0100] wherein β a vertical viewing half-angle in a minimum magnification (doubled) of the camera engine, zoom is a current magnification.
[0101] In order to make calculation simple, a condition that the OC is in the VOW plane may be considered. In this condition, the coordinate of the P (u, v, w) is as follows.
[0000]
u=U;
[0000] v=R ×cos Tilt− v ×sin Tilt;
[0000] w=R ×sin Tilt+ v ×cos Tilt;
[0102] wherein cos Tilt and sin Tilt are respectively a cosine function and a sine function of an angle between the OC and v axis.
[0103] Thus, the relative offset angle of longitude of the OP axis is:
[0000] P =arctan( u/v )
[0104] An absolute latitude angle is:
[0000] T =arctan( w /√{square root over ( u 2 +v 2 )})
[0105] According to the calculation above, the spherical coordinate (u, v, w) is obtained according to the coordinate of (x, y) in the shot tracking image, and the P value and the T value is obtained accordingly.
[0106] Since the location coordinate of the current tracking target in the tracking image collected by the image collection module 12 is updated in real time, the DSP 112 continuously transmits the updated coordinate to the ARM processor 111 in real time. Thus, the intelligent tracking fast-speed dome 1 can adjust a shooting direction in real time according to the changed location of the tracking target so as to ensure that the target is tracked.
[0107] When the current tracking target is tracked in real time, a change of the current tracking target in the tracking image collected in the image collection module 12 is transformed to the P value, the T value and the Z value recognized by the intelligent tracking fast-speed dome 1 in order to automatically control the shooting direction and the magnification of the intelligent tracking fast-speed dome 1 . The location coordinate of the current tracking target in the tracking image collected by the image collection module is transformed to the P value, the T value and the Z value that can be recognized by the intelligent tracking fast-speed dome 1 . The transforming process includes procedures as follows.
[0108] In step 41 , the location coordinate of the current tracking target in the tracking image collected by the image collection module is transformed to a spherical coordinate taking the speed dome as a center.
[0109] In step 42 , The P value and the T value are obtained according to the spherical coordinate.
[0110] In step 43 , according to the location information of the current tracking target in the tracking image collected by the image collection module and the magnification coefficient of the speed dome, the Z value is obtained.
[0111] In particular, steps III to IV are implemented according to a method as follows.
[0112] In the geometric model as shown in FIG. 5 , the intelligent tracking fast-speed dome 1 locates in a center dot O of the half-sphere. A horizontal direction of a spherical coordinate system of the half-sphere taking the intelligent tracking fast-speed dome 1 as the center includes a u direction and a v direction that are vertical with the u direction. The vertical direction of the spherical coordinate system includes a w direction that is vertical with the u direction and the v direction. The OC is the optical axis of the camera lens of the intelligent tracking fast-speed dome 1 . A tangent plane where the doc C on a spherical surface of the half-sphere locates in the FIG. 5 is an image plane in FIG. 4 , i.e., the tracking image plane collected by the image collecting module 12 . The image plane may move along with changing the direction angle of the intelligent tracking fast-speed dome 1 , but is static relative to the optical axis of the camera lens of the intelligent tracking fast-speed dome 1 . In FIG. 5 , the coordinate (u, v, w) is equivalent to a three-dimensional coordinate (x, y, z). In order to distinguish the three-dimensional coordinate (x, y, z) with the location coordinate of the newly-selected target (x, y) and the normalization coordination (x′, y′), the three-dimensional coordination is represented with (u, v, w). According to a conversion relation between the three-dimensional coordinate (u, v, w) and the spherical coordinate (r, θ, φ), it may be obtained:
[0000] φ=arctan( v/u )
[0000] θ=arctan( w /√{square root over ( u 2 +v 2 )})
[0113] Wherein φ is a rotation angle from the dot O of the half-sphere (i.e., the intelligent tracking fast-speed dome 1 ) along the horizontal direction as shown in FIG. 5 , θ is a rotation angle from the dot O of the half-sphere (i.e., the intelligent tracking fast-speed dome 1 ) along the vertical direction as shown in FIG. 5 . A value of the φ and a value of the θ correspond to the P (horizontal rotation) value and the T (vertical rotation) value. That is, when the coordinate of the current tracking target in the spherical coordinate system taking the speed dome as the center is (u, v, w),
[0000] P =arctan( v/u ) (4)
[0000] T =arctan( w /√{square root over ( u 2 +v 2 )}) (5)
[0114] In step V, the Z value can be implemented according to method above (a process of obtaining Z can in accordance with procedures at block 2 and formula (1)).
[0115] According to the step II above, the magnification coefficient of the intelligent tracking fast-speed dome 1 is Z ref , i.e., Z ref =Z 0 ×sin(T 0 ). It is assumed that an angle of the camera lens of the speed dome and location information of the current tracking target is T 1 ,
[0000] Z=Z ref /sin( T 1 ) (6)
[0116] wherein sin(T 1 ) is an adjustment function of the dynamic magnification coefficient of the location information of the current tracking target. The sin(T 1 ) may be implemented as follows. When T 1 is large, a viewing area of the intelligent tracking fast-speed dome 1 is enlarged in order to avoid a shift of the tracking target characteristic point. When T 1 is small, the magnification value is increased in order to obtain the plentiful information of the tracking target.
[0117] Calculation of the P value, the T value and the Z value is performed in the ARM processor 111 .
[0118] At block 5 , according to the Z value, the magnification of the speed dome is adjusted in real time, according to the P value and the T value, the rotation of the speed dome is controlled in real time.
[0119] The adjustment module 17 adjusts the magnification of the speed dome in real time according to the Z value, controls the rotation of the speed dome according to the P value and the T value. In particular, the adjustment module 17 includes a zoom motor 13 , a horizontal rotation motor 14 and a vertical rotation motor 15 . The zoom motor 13 adjusts the magnification of the speed dome in real time according to the Z value. The horizontal rotation motor 14 controls the horizontal rotation of the speed dome according to the P value. The vertical rotation motor 15 controls the vertical rotation of the speed dome according to the T value. That is, the horizontal rotation motor 14 and the vertical rotation motor 15 control the rotation of the speed dome in real time.
[0120] After the Z value is obtained according to formula (6), the central processor 11 , e.g., the ARM processor 111 outputs the Z value to the zoom motor 13 through the driven circuit 16 in order to implement automatic control of the magnification.
[0121] After the P value and the T value are obtained according to formulas (4) and (5), the ARM processor 111 respectively outputs the P value and T value to the horizontal rotation motor 14 and the vertical rotation motor 15 through the driven circuit 16 to implement automatic rotation control of the intelligent tracking fast-speed dome 1 .
[0122] In a practical control, the P value and T value are outputted to the horizontal rotation motor 14 and the vertical rotation motor 15 , thus, a condition of the discontinuous image may occur. In order to obtain a smooth image when tracking is performed, a control method based on a target speed is used in the present invention. Difference is performed respectively between the obtained P value, the obtained T value and the current P value and the current T value of the horizontal rotation motor 14 and the vertical rotation motor 15 as follows. It is assumed that the new P value and the new T value of the current tracking target in the spherical coordinate system taking the intelligent tracking fast-speed dome 1 as the center are respectively P new , T new . The current P value and the current T value in the spherical coordinate system are respectively P cur , T cur . Time when a frame of the tracking image is processed is Δt. A value and a direction of a speed of the current tracking image are determined according to the following formula:
[0000]
V
pan
=
Δ
P
Δ
t
=
P
new
-
P
cur
Δ
t
(
7
)
V
tilt
=
Δ
T
Δ
t
=
T
new
-
T
cur
Δ
t
(
8
)
[0123] wherein V pan is a moving speed of the current tracking target along a horizontal rotation direction in a spherical coordinate system taking the intelligent tracking fast-speed dome 1 as the center, V tilt is a moving speed of the current tracking target along a vertical rotation direction in a spherical coordinate system taking the intelligent tracking fast-speed dome 1 as the center. According to the value and the direction of the speed of the current tracking target, the intelligent tracking fast-speed dome 1 is controlled to perform accelerating rotation and decelerating rotation, so that the intelligent tracking fast-speed dome 1 can perform smooth rotation. The control process is illustrated in FIG. 6 , which includes procedures as follows.
[0124] At block a, it is determined whether the moving direction of the current tracking target is same with the current rotation direction of the intelligent tracking fast-speed dome 1 , when the moving direction of the current tracking target is same with the current rotation direction of the intelligent tracking fast-speed dome 1 , procedures at block b are performed, otherwise, procedures at block f are performed.
[0125] At block b, it is determined whether the moving speed of the current tracking target is more than the current rotation speed of the intelligent tracking fast-speed dome 1 , when the moving speed of the current tracking target is more than the current rotation speed of the intelligent tracking fast-speed dome 1 , procedures at block c are performed, otherwise, procedures at block d are performed.
[0126] At block c, the current rotation speed of the intelligent tracking fast-speed dome 1 is accelerated, and the procedures at block d are performed.
[0127] At block d, it is determined whether the moving speed of the current tracking target is equal to the current rotation speed of the intelligent tracking fast-speed dome 1 , when the moving speed of the current tracking target is equal to the current rotation speed of the intelligent tracking fast-speed dome 1 , procedures at block i are performed, otherwise, procedures at block e are performed.
[0128] At block e, the current rotation speed of the intelligent tracking fast-speed dome 1 is decelerated, and the procedures at block d are performed.
[0129] At block f, the current rotation speed of the intelligent tracking fast-speed dome 1 is decelerated, and procedures at block g are performed.
[0130] At block g, it is determined whether the current rotation speed of the intelligent tracking fast-speed dome 1 is equal to zero, when the current rotation speed of the intelligent tracking fast-speed dome 1 is equal to zero, procedures at block h are performed, otherwise, procedures at block f are performed.
[0131] At block h, the rotation direction of the intelligent tracking fast-speed dome 1 is changed, and the procedures at block b are performed.
[0132] At block i, the current tracking target is tracked according to the current rotation speed.
[0133] In a process of tracking a target according to procedures at the blocks above, the ARM processor 111 may wait for the host computer 2 to select a new target at any time. After the host computer 2 re-selects the new target, a new process of tracking a target is triggered according to the condition at block 1 .
[0134] As shown in FIG. 1 , a system for an intelligent tracking fast-speed dome provided according to an embodiment of the present invention includes an intelligent tracking fast-speed dome 1 and a host computer 2 .
[0135] The host computer 2 is to transmit a location coordinate of a newly-selected target in a tracking image to the intelligent tracking fast-speed dome 1 in a process of tracking a target.
[0136] The intelligent tracking fast-speed dome 1 includes a central processor 11 , an image collecting module 12 , and an adjustment module 17 . The central processor 11 is to match a location coordinate of a newly-selected target in a tracking image collected by the image collecting module 12 when receiving the location coordinate of the newly-selected target in the tracking image in a process of tracking a target, set a target corresponding to the location coordinate of the newly-selected target as a current target, extract a characteristic of the current target, track the current target according to the characteristic of the current target. The central processor 11 is to in real time update the location coordinate of the current target in the tracking image, in real time transform the updated location coordinate of the current target to a Pan (P) value, a Tilt (T) value and a Zoom (Z) value recognizable for a speed dome, output to the adjustment module 17 the P value, the T value and the Z value via a driven circuit 16 .
[0137] The adjustment module 17 is to in real time adjust a magnification according to the Z value, in real time control rotation of the speed dome according to the P value and the T value.
[0138] The central processor may include an ARM processor 111 , a DSP 112 . The ARM processor 111 is to transmit to the DSP 112 the received location coordinate of the newly-selected target in the tracking image transmitted from the host computer 2 , in real time transform the received updated location coordinate of the current target transmitted from the DSP 112 to the P value, the T value and the Z value recognizable for a speed dome, output to the adjustment module the P value, the T value and the Z value via the driven circuit. The DSP 112 is to match a location coordinate of a newly-selected target in a tracking image collected by the image collecting module 12 when receiving the location coordinate of the newly-selected target in the tracking image in a process of tracking a target, set a target corresponding to the location coordinate of the newly-selected target as a current target, extract a characteristic of the current target, track the current target according to the characteristic of the current target, in real time update the location coordinate of the current target in the tracking image, transmit the updated location coordinate of the current target to the ARM processor 111 .
[0139] The central processor 11 is further to select a monitoring scenario, and calibrate a magnification coefficient of the speed dome. The central processor 11 is further to transform the location coordinate of the newly-selected target to a normalized coordinate, wherein the normalized coordinate a coordinate value after a normalization processing corresponding to a length and a width of the image is performed. The central processor 11 is further to transform the updated location coordinate of the current target to a spherical coordinate setting the speed dome as a center, obtain the P value and the T value of the spherical coordinate, obtain the Z value according to location information of the current target and the magnification coefficient of the speed dome.
[0140] The adjustment module 17 includes a z zoom motor 13 , a horizontal rotation motor 14 and a vertical rotation motor 15 . The zoom motor 13 is to in real time adjust the magnification according to the Z value. The horizontal rotation motor 14 is to in real time control horizontal rotation of the speed dome according to the P value. The vertical rotation motor 15 is to in real time control vertical rotation of the speed dome according to the T value.
[0141] According to the target tracking method for an intelligent tracking fast-speed dome, the intelligent tracking fast-speed dome and the target tracking system for an intelligent tracking fast-speed dome provided according to embodiments of the present invention, when multiple targets occur in a scenario, a monitoring person can select a target concerned by the monitoring person to perform a selective tracking process and solve a problem that in the scenario that the multiple targets occur, the tracking target is not the concerned target, the concerned target is missed, and a monitoring purpose cannot be achieved. At the same time, in a tracking process of the speed dome, since the scenario is complicated and an image analysis technology is limited, a condition may occur that the target is missed or is blocked by another target. According to the method of the present invention, the target can be re-selected. In addition, in a scenario that a large target is tracked, e.g., a large truck, in a conventional method, a target for image analysis may be on a top of the truck or another part, and may not be in a concerned license plate location, which may cause that in the tracking process, the license plate cannot be seen. According to the method, the speed dome and the system for the speed dome of the present invention, the license plate part can be selected to be tracked.
[0142] The foregoing is only preferred examples of the present invention and is not used to limit the protection scope of the present invention. Any modification, equivalent substitution and improvement without departing from the spirit and principle of the present invention are within the protection scope of the present invention.
|
Disclosed is a target tracking method for an intelligent tracking high speed dome, comprising: in the process of target tracking, when the position coordinates of a newly selected target in the acquired tracking image are received, matching the position coordinates of the newly selected target in the tracking image, using the target corresponding to the position coordinates of the newly selected target in the tracking image as a current target, and extracting the characteristics of the current target; tracking the current target according to the characteristics thereof, and updating in real time the position coordinates of the current target in the tracking image; converting the updated position coordinates of the current target into speed dome identifiable horizontal rotation value P, vertical rotation value T and magnification factor value Z; adjusting in real time the magnification factor of the speed dome according to the value Z, and controlling in real time the rotation of the speed dome according to the value P and the value Z. When a plurality of the targets appear in a specific scene, the present invention can lock a concerned target and track the target selectively, thus solving the previous problem of tracking an unconcerned target; furthermore, the method of the present invention can reselect and track a target by locking the target manually, thus solving the problem of losing the target.
| 6
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This is a divisional of application Ser. No. 08/159,272 filed on Nov. 30, 1993, now U.S. Pat. No. 5,585,176.
TECHNICAL FIELD
The present invention relates to wear parts and tools having a strongly adherent diamond coating deposited thereupon and to a process for making these products. It is especially concerned with diamond coated cutting tools for chip forming machining and a process for making them.
BACKGROUND
In recent years, chemical vapor deposition (CVD) diamond coatings have been applied to a variety of substrate-material cutting tools intended for the same applications as single point, brazed-on polycrystalline diamond (PCD) tipped tools (see "Advanced Cutting Tool Materials," Kennametal Inc. (1988), Pages 1, 2, 77-86, 94-98, 101 and 102). While CVD diamond coated tools provide the machinist with multiple cutting edges on inserts with or without chipbreaker structures, their inconsistent machining results, due to poor coating adhesion, has resulted in a failure of the CVD diamond coated tools to be competitive with PCD tools in most commercial applications.
Various approaches have been made to the formation of diamond coating layers on various surfaces by CVD methods (e.g., hot filament, DC plasma Jet and microwave plasma) in which gases such as methane (CH 4 ) are thermally decomposed. However, diamond coating layers formed by low pressure vapor-phase synthesis methods generally have a low adhesive bond strength to the substrate. Accordingly, what is desired is a coated substrate in which the adherence of the coating to the substrate is sufficient to retain the coating on the substrate for the time that it takes for the coating to gradually wear out by abrasion during machining of a workpiece material. Early or premature flaking of the coating prior to the wearing out of the coating causes unpredictable and inconsistent tool lifetimes, which is unacceptable to most users of PCD tipped tools. In addition, the diamond coating thickness should be thick enough so that each cutting edge provides at least forty percent of the wear life of PCD tools in order to be competitive with those tools.
One approach to this problem is disclosed in U.S. Pat. No. 5,068,148, which issued on Nov. 26, 1991. The '148 reference discloses a method for producing a diamond coated tool member wherein a cemented carbide substrate is chemically etched to remove cobalt existing in the outermost portion of the substrate. Such etching steps may generate internal interconnecting porosity which diminishes the toughness and wear resistance of the cutting tool insert, but absent chemical etching, tool performance may diminish due to coating delamination caused by poor preparation of the substrate surface (e.g., too much cobalt left on the surface). The '148 reference calls for heat-treating a ground substrate at a temperature between 1000° C.-1600° C. for 30 to 90 minutes in a vacuum or in a non-oxidizing atmosphere before chemical etching. If the heat treating temperature exceeds 1600° C., the hard grains of the substrate become bulky, and the surface of the substrate becomes extraordinarily rough, so that the substrate cannot be used for manufacturing a tool member.
In another approach, disclosed in European Patent Application No. 0 518 587, the surfaces of a cemented tungsten carbide substrate are also etched for the purpose of improving diamond coating adherence.
It is the inventors' belief, after examination of diamond coated cemented carbide tools presently being commercially marketed, that where an etching step is used to improve diamond adhesion (to 60 to 100 kg in the Rockwell A indentation adhesion test), etching has preferentially removed significant amounts of cobalt from the surface and from just beneath the surface. This results in interconnected porosity just beneath the substrate surface, creating a weakened structure which undermines the ability of the diamond coating to remain attached to the tool during machining operations, and which results in flaking of the coating, especially during interrupted machining operations.
U.S. Pat. No. 5,204,167, which issued on Apr. 20, 1993, discloses a diamond coated sintered body in which the average size of recrystallized tungsten carbide in the surface layer is finer as compared with that existing in the inner portions of the substrate. The '167 reference teaches that increased adhesion between the diamond film and the substrate is because graphite generated at an initial stage of diamond deposition is used for recarburization of a surface decarburized layer of the substrate, so that graphite formed at the interface between the surface layer and the film is decreased.
Such approaches leave unsolved the challenge of providing a high bond strength between the coating and the substrate.
Current practice in the design of conventional, PCD cutting tools calls for the tool to have a sharp cutting edge for both turning and milling applications on non-ferrous and non-metallic workpieces. The use of sharp edges provides lower cutting tool forces during machining and workpiece surface finishes having the required characteristics, e.g., low surface roughness.
Diamond coated cutting tool inserts should ideally provide the same workpiece surface characteristics to be commercially competitive with conventional PCD tools. Another one of the factors currently limiting the acceptance of diamond coated tools has been the difficulty of providing acceptable workpiece surface finishes, especially in finishing operations. Conventional PCD tools often contain a metallic binder, such as cobalt, which holds the diamond particles together. When properly ground, the PCD provides a substantially smooth cutting surface and imparts a substantially smooth surface to the workpiece. In contrast, diamond coatings do not contain a binder phase. They typically have a rough, faceted surface on a microscopic scale. Such microscopic roughness leads to rough workpiece finishes in cutting operations. Under prior approaches, the purer (or more perfect) the diamond coating, i.e., more sp 3 and less sp 2 (graphitic) bonded component, the more highly faceted the coating becomes. Such coatings can be made smoother by increasing the amount of graphitic component, but wear resistance, and tool lifetime, decrease as a result. Although chemical polishing with reactive materials and compounds or mechanical polishing with diamond grit may be used to produce a smooth diamond surface, the road remained open for improved approaches.
Accordingly, it would be desirable to provide a high purity diamond coating on a cutting tool substrate that will be highly adherent in use, and will preferably achieve workpiece surface finishes comparable to those provided by conventional PCD tools.
Until the present invention, there remained an unsolved need for simple, yet effective techniques for consistently providing a highly adherent diamond coating and for providing a smooth surface of a high purity, highly faceted diamond coating on a three-dimensional shape, e.g., a cutting tool insert.
SUMMARY OF THE INVENTION
The product according to the present invention is directed to a diamond coated wear part tool, preferably a cutting tool for chip forming machining of materials.
The wear part or tool has a cermet substrate, to which a diamond coating is adherently bonded. The cermet substrate has hard grains bonded together by a metallic binder. At the substrate surface, there are hard grains that are large. These large, hard grains provide the substrate with an irregular surface. The diamond coating has a strong adhesion to the irregular substrate surface. Where the tool is a cutting tool for chip forming machining of a material, the substrate has a flank surface and a rake surface and a cutting edge formed at the Juncture of the rake and flank surfaces. The diamond coating is adherently bonded to each of these surfaces. The substrate, in accordance with the present invention, is also preferably characterized by an absence of interconnected porosity in the substrate regions adjacent to the irregular substrate surfaces to which the diamond coating is bonded.
In a preferred embodiment of the present product, the cermet substrate is a tungsten carbide based (i.e., >50 w/o WC) cemented carbide and said hard grains include tungsten carbide grains.
Preferably, the metallic binder forms about 0.2 to 20 w/o of the tungsten carbide based cemented carbide and the metallic binder is selected from the group of cobalt, cobalt alloys, iron, iron alloys, nickel and nickel alloys.
In a more preferred embodiment, the metallic binder is cobalt, or a cobalt alloy, and cobalt forms about 0.5 to about 7 weight percent, and most preferably, about 1.0 to about 7 weight percent of the tungsten carbide based cemented carbide.
Preferably, the average adhesion strength of the diamond coating to the substrate surface is at least 45 kg, and more preferably, at least 60 kg, and most preferably, at least 80 kg in Rockwell A indentation tests.
The diamond coating on the rake face of cutting tools preferably has an average thickness of about 5 to about 100 μm, more preferably 22 to 100 μm, with about 22 to about 50 being preferable for tools to be used in continuous and interrupted finish turning of aluminum alloys such as A380 and A390 to obtain acceptable tool lives at a reasonable manufacturing cost.
In a preferred option, especially for finish machining applications, the diamond coating adherently bonded to the rake face is substantially left in its as-deposited rough surface condition, preferably, having a surface roughness, R a , of greater than 35 microinches, while the diamond coating adherently bonded to the flank surface is made smoother.
The product according to the present invention is preferably made by a process, also in accordance with the present invention, which comprises the steps of:
1. Sintering a cermet substrate for a time, at a temperature and in an atmosphere to produce grain growth on the substrate surfaces sufficient to provide the substrate rake surface with a surface roughness, R a , of greater than 25 microinches, while reducing the concentration of metallic binder on that surface. Preferably, the surface roughness, R a , produced in the sintering step, is greater than 30 microinches, and more preferably, at least 40 microinches. A surface roughness R a , of at least 50 microinches is also contemplated. The atmosphere used, preferably, is nitrogen, at a partial pressure of about 0.3 to about 50 torr, preferably, about 0.3 to 5 torr, more preferably, about 0.3 to 2.0 torr, and most preferably, about 0.3 to 0.7 torr.
2. These surfaces are then diamond coated by adherently depositing, by vapor deposition, a diamond coating thereon. Preferably, the substrate temperature during the diamond deposition process is between 700° C. and 875° C., and is more preferably, about 750° C. to about 850° C.
This process is controlled to produce an average adhesion strength between the diamond coating and the substrate of greater than 45 kg, preferably, at least 60 kg, and more preferably, at least 80 kg, as determined by the Rockwell A indentation technique.
Preferably, following the sintering step, the surfaces of the substrate to be coated are scratched with diamond to create diamond nucleation sites in preparation for diamond coating.
In another preferred embodiment of the present invention, the step of smoothing the surface roughness of the diamond on the flank face of the tool is performed, preferably, by buffing the flank face.
In still a further preferred embodiment of the present invention, the cermet substrate prior to the sintering step described above is at least substantially fully densified (i.e., has been previously sintered) and has a surface which is in a ground condition.
These and other aspects of the present invention will become more apparent upon review of the detailed description of the invention in conjunction with the drawings, which are briefly described below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A shows an embodiment of a cutting tool substrate in accordance with the present invention.
FIG. 1B shows a partial cross section through the cutting tool substrate of FIG. 1A perpendicular to a cutting edge after it has been coated in accordance with the present invention.
FIGS. 2-11 are scanning electron microscopy (SEM) photomicrographs which depict secondary electron images (SEI) of a cutting tool at various stages in a preferred embodiment of the process and product of the present invention. (All figures are at 2000× magnification, except for FIG. 10, which is at 1000×.)
FIG. 12 illustrates an optional buffing step using a rotating brush impregnated with diamond grit.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the present invention, FIG. 1A shows a preferred embodiment of an indexable cutting tool substrate to be coated with diamond in accordance with the present invention. The tool substrate has a rake surface 30 and flank surface 50. At the juncture of the rake surface 30 and the flank surface 50 is a cutting edge 70. The cutting edge 70 may be in either a sharp, honed, chamfered, or chamfered and honed condition, depending on application requirements. The hone may be any of the styles or sizes of hones used in the cutting tool industry. Preferably, the cutting edge has a radius hone, preferably, of about 0.0005 to 0.0015 inch. The cutting tool substrate may also be made in any of the standard shapes and sizes (for example, SNGN-422 and TPGN-322 (see ANSI B212.4-1986)). Inserts may also have various chipbreaker structures (not shown) on their rake face as well to facilitate breakage and removal of chips. Where chipbreaker structures are to be coated, some or all of these structures may be in an as-molded condition (i.e., unground).
In accordance with the present invention, FIG. 1B shows a partial cross section through the coated cutting tool 80 which is composed of the cermet substrate 10, shown in FIG. 1A, with a diamond coating 90 adherently bonded to its rake surface 30, flank surfaces 50 and cutting edges 70. The bottom surface of the substrate 10 may or may not be coated with diamond.
The substrate used in the present invention is a cermet having hard grains and a metallic binder holding said hard grains together. The cermet composition may be any of those used in the prior art for cutting tool applications and include titanium carbonitride based and tungsten carbide based compositions. The metallic binder utilized in these compositions include cobalt, cobalt alloys, nickel, nickel alloys, iron and iron alloys.
Preferably, a tungsten carbide based (>50 w/o WC) cemented carbide is utilized for the substrate. Such a composition should have about 0.5 to about 20 w/o, preferably, 1.0 to 7 w/o, metallic binder of cobalt or a cobalt alloy. Such a composition would contain hard tungsten carbide grains and may also contain other hard grains, including carbides, nitrides and carbonitrides of other elements, solid solution carbides and solid solution carbonitrides of tungsten and other elements. Such elements may include Ti, Hf, Zr, Ta, Nb, V, Mo and Cr. In a preferred embodiment, the presence of Ti, Hf, Zr, Ta, Nb, V, Mo and Cr is limited to less than 1 w/o, and more preferably, less than 0.6 w/o total, such that the cemented carbide substrate consists of tungsten carbide and cobalt or a cobalt alloy (such as a Co--W alloy).
For example, applicants have found that the present invention provides particularly good adhesion results when two tungsten carbide based cemented carbide compositions are used for the starting material for the substrate, as follows:
Alloy A: W+C+5.7 to 6.3 w/o Co, up to 0.1 w/o Ta, up to 0.1 w/o Ti, up to 0.1 w/o Nb, 0.3 to 0.5 w/o Cr, remainder other impurities, Rockwell A hardness 92.6 to 93.4, coercive force, Hc, 250-320 oersteds, magnetic saturation 83 to 95%, average WC grain size 1-5 μm and a porosity rating of A04, B00, C00 or better, density 14.80 to 15.00 g/cc.
Alloy B: W+C+2.3 to 2.9 w/o Co, up to 0.4 w/o Ta, up to 0.1 w/o Ti, up to 0.1 w/o Nb, remainder other impurities, Rockwell A hardness 92.8 to 93.6, coercive force, Hc, 290-440 oersteds, magnetic saturation sufficient to avoid eta phase, average WC grain size 1-6 μm, porosity rating of A08, B00, C00 or better, density 15.10 to 15.50 g/cc.
FIG. 2 shows a SEM photomicrograph of an Alloy B starting material substrate flank surface at 2000×. FIG. 3 shows a SEM photomicrograph of a fracture cross section of the same material at 2000×. Both photomicrographs show the substrate in an as-sintered condition. It will be noted in the photomicrographs that the average hard grain size (here WC) at the surface of the substrate is approximately the same as that in the interior.
While this material was fabricated by cold pressing and vacuum (10 -2 to 10 -3 torr) sintering techniques, it should be understood that any of conventional techniques may be used to obtain the starting material for the present invention, e.g., cold pressing, cold pressing and sintering (vacuum, pressure or hot isostatic pressing or any combination thereof) or hot pressing. The surface of an as-vacuum sintered tungsten carbide based cemented carbide substrate is composed of tungsten carbide hard grains bound together by cobalt or a cobalt alloy. The cobalt is not only between the tungsten carbide grains, but also covers some of the tungsten carbide grains at the substrate surface due to the wetting properties of Co and WC under vacuum sintering conditions.
Typically, the as-sintered substrate is wholly or partially ground (e.g., chipbreaker structures on the rake surface may be left in an as-molded condition) to provide exact dimensional control of the substrate. Operations, such as grinding and honing, (which may also be performed at this stage of manufacture) act to smear the cobalt over the surfaces of the substrate. An Alloy B ground rake surface is shown in FIG. 4. FIG. 5 shows a fracture cross section through the as-ground Alloy B insert, in which it will be noted that the grinding has smoothed the surface roughness of the substrate compared to that shown in FIGS. 2 and 3.
Now in accordance with the present invention, the substrate described above is now sintered (or re-sintered) under time, temperature and atmospheric conditions, to cause grain growth and binder depletion from its surfaces. The time and temperature are selected such that sufficient abnormal or exaggerated grain growth occurs on the surface of the substrate to produce a surface roughness, R a , of greater than 25 microinches, preferably, greater than 30 microinches, and more preferably, at least 40 microinches. A surface roughness, R a , of at least 50 microinches is also contemplated.
FIGS. 6 and 7 illustrate the results of this re-sintering step through photomicrographs (2000×) of the surface morphology (FIG. 6) and fracture cross section (FIG. 7) of a rake surface of a re-sintered Alloy B insert. FIGS. 6 and 7 show that the surface may have a mixture of large and small grains. The large grains shown at the surface, preferably include grains having a major dimension with a size of at least 10 μm, and more preferably, at least 15 μm to produce the desired degree of surface roughness.
SEM energy dispersive line scan x-ray analysis (EDS) of polished cross sections of Alloy B substrates in the sintered and ground state, and in a re-sintered state, have shown that cobalt is being evaporated from the substrates during re-sintering. Before re-sintering, EDS and optical metallography showed that the as-sintered and ground substrates (substrates included an as-molded chipbreaker structure (nonground) e.g., CPGM-21.51) had a cobalt content of about 2.7 to 2.8 w/o (about 2.9 w/o by x-ray fluorescence) throughout, with scattered pools of cobalt throughout the samples, an A06 to A10 porosity rating, and a typical tungsten carbide grain size of about 1 to 6 μm, with a few scattered grains throughout, up to about 10 μm.
After re-sintering, in accordance with the present invention, cobalt content and cobalt pool size was reduced, the porosity rating was improved, and the tungsten carbide grain size was increased. The porosity rating was A02 to A06 (no interconnected porosity was observed near the surface regions of the samples, or anywhere else in the samples). The tungsten carbide grain size was non-uniform and ranged from about 1 to 11 μm, with the larger grains and/or the frequency of larger grains being higher at the surfaces of the samples. Large grains, up to 16 to 28 μm in size, were observed. In the CPGM-21.51 sample, large grains were produced on as-molded surfaces as well as ground surfaces. In a CPGN-422 sample, the cobalt content was substantially uniformly reduced throughout, to about 2 w/o (EDS and x-ray fluorescence). In a CPGM-21.51 sample, the cobalt content was substantially uniformly reduced throughout, to about 0.5 w/o. In both samples, the variability in cobalt content about the mean was also reduced, indicating a reduction in cobalt pool size (i.e., a more uniform distribution of cobalt). The difference in the amount of cobalt evaporation from the CPGN-422 and CPGM-21.51 samples indicates that the amount of cobalt evaporation is also a function of insert surface area to volume ratio. As this ratio increases, the amount of cobalt evaporation for a given re-sintering treatment should increase.
Re-sintering was performed at 2750° F. for three hours in about 0.5 torr nitrogen atmosphere. The times required to achieve the required surface roughness will depend on the starting material and the sintering conditions. As temperature increases, sintering times should decrease. With Alloy B sintered and ground substrates, the re-sintering times of 2 to 3 hours at 1510° C. (2750° F.) have been found to be sufficient to provide the needed surface roughness. In Alloy A, longer sintering times have been found to be necessary.
If the desired surface roughness is not produced after the first re-sintering treatment, the substrate may be re-sintered again until the desired surface roughness is produced.
It is believed that the atmosphere during the sintering (or re-sintering) treatment, in accordance with the present invention, is also important to obtaining good diamond coating adhesion to the substrate. It is believed that, if a nitrogen atmosphere is utilized during this treatment, the amount of cobalt on the resulting rough surface will be minimized. The nitrogen partial pressure should be controlled to allow cobalt evaporation from the surface, while minimizing re-wetting of the surface by additional cobalt from the bulk of the substrate and while preferably avoiding any noticable formation of a nitride layer on the surface of the substrate.
The most beneficial nitrogen partial pressure may, therefore, be a function of the substrate composition. Nitrogen partial pressure may also be controlled or varied during the re-sintering cycle(s) to control the amount and rate of cobalt evaporation from the bulk of the substrate.
It is believed that a 0.3 to 50 torr, preferably, 0.3 to 5, and more preferably, 0.3 to 2 torr nitrogen atmosphere should be utilized. Applicants' best results have been achieved with a nitrogen atmosphere of 0.3 to 0.7 torr with the Alloy B grade in their furnace. It is theorized that the nitrogen atmosphere may allow cobalt on the exterior surfaces of the grains on the substrate surface to evaporate, while sufficient cobalt remains between the surface tungsten carbide grains to keep them well bonded to the remainder of the substrate. Cobalt surface evaporation is accompanied by tungsten carbide grain growth at the surface, resulting in surface roughening.
The rake and flank surfaces of the cutting tool substrate may then be beneficially scratched by any conventional means (e.g., diamond grit or diamond paste) to create nucleation sites in preparation for diamond coating.
Diamond coating of the substrates is then accomplished by a vapor deposition technique (e.g., hot filament, DC plasma jet or microwave plasma). In the application of the diamond coating, it is preferred that the substrate temperature during coating be maintained between 700° and 875° C. Below about 700° C., too much graphite is formed in the diamond coating and the wear resistance is thereby significantly reduced. In addition, the rate of coating is also reduced. Above about 875° C., too much cobalt diffuses from the substrate during coating and the adhesion of the diamond to the substrate is adversely affected. It has been found to be more preferable to perform diamond coating at about 750° C. to about 850° C. At these temperatures, the adverse conditions mentioned above can be minimized and a reasonable coating rate can be obtained.
FIG. 8 (2000×) depicts the surface morphology of an as-deposited diamond coating on the flank surface of a cutting tool in accordance with the present invention. The rough faceted surface shown is indicative of a high purity diamond coating having minimal, if any, sp 2 phase (graphite) and binder from the substrate. This diamond coating was produced in a CVD hot filament system.
FIG. 9 (2000×) illustrates a diamond coating surface on a flank face of an insert after it has been buffed. By comparing FIGS. 8 and 9, one can readily see the smoothing effect that buffing has on the surface morphology of the diamond coating. Buffing is performed to eliminate the higher surface asperities on the surface of the diamond coating on the flank surface in order to improve the surface finish that will be imparted to the workpiece being machined. Preferably, sufficient buffing is performed such that the surface roughness, R a , of the flank surface near the corners of the insert is reduced by at least 10 microinches.
Turning next to FIGS. 10-11, there are respectively depicted fracture cross sections of a rake surface of a diamond coated/re-sintered cutting tool insert interface. FIG. 10 is taken at a magnification factor of 1000, while the magnification factor of FIG. 11 is 2000. These figures show mechanical interlocking of the coating with the irregular rake surface of the substrate created by the large tungsten carbide surface grains. It is theorized that the minimization of the cobalt on the surfaces of the tungsten carbide grains enhances direct nucleation of the diamond on the tungsten carbide. Both enhanced nucleation and mechanical interlocking improve the adhesion of the diamond coating.
Adhesive strength of diamond coatings on cermet inserts is a complex function of intrinsic and extrinsic parameters. They include surface roughness, chemical compatibility of the surfaces, compatibility of thermal expansion coefficients, surface preparation, nucleation density and coating temperature. In polycrystalline diamond coatings on carbide inserts, adhesive strength is substantially reduced by the binder concentration on the cermet surface. The re-sintering step of the present invention is believed to achieve the goal of creating sufficient binder (e.g., cobalt) depletion to achieve good diamond to substrate bonding, but not so much cobalt depletion so as to significantly weaken the bonding of the surface WC grains to the remainder of the substrate. The need for etching of the substrate surface to remove cobalt therefrom, with its attendant formation of interconnected porosity in the regions adjacent to the substrate surface, has been avoided.
The efficacy of the disclosed process is additionally illustrated by the following further examples.
In another experiment, SPGN-422 style blanks were pill-pressed at 30,000 psi out of a Alloy B grade powder blend. The blanks were then sintered at 1496° C. (2725° F.) for 30 minutes in a conventional vacuum cemented carbide sintering cycle. They were then ground to the SPGN-422 dimensions and reheated in a re-sintering cycle as listed in Table I. The partial pressure of the nitrogen atmosphere in which the re-sintering step was performed was approximately 0.5 torr at the load which was in a directly pumped gas permeable graphite box through which about 2.5-3.0 liters/minute of nitrogen was continually flowing. Nitrogen was first introduced at about 538° C. (1000° F.) during heating to the re-sintering temperature and maintained thereafter, until 1149° C. (2100° F.) was reached during cooling. At that time, the nitrogen was replaced by helium.
Following re-sintering, the surface roughness of the reheated inserts was measured with a standard Sheffield Proficorder Spectre unit. The measurements were performed in two sites on the inserts. Then the inserts were: (1) ultrasonically cleaned (sonicated in a micro-clean solution in water, rinsed with water, sonicated in acetone, and finally in methanol); (2) diamond seeded (by either hand scratching with 0.25 μm diamond paste or by sonicating in a slurry of 0.5 to 3 μm diamond powder in 100 ml of acetone); and (3) diamond-coated in a CVD hot filament system (in a mixture of 1% methane and 99% hydrogen, at 10 torr total gas pressure and at a substrate temperature of about 775° to about 850° C.) to produce a diamond coating thickness of about 5 to 10 μm.
Adhesion between the diamond coating and the carbide surface was determined by an indentation adhesion test using a Rockwell hardness tester with a Rockwell A scale Brale cone shaped diamond indenter at a selected load range: 15 kg, 30 kg, 45 kg, 60 kg and 100 kg. The adhesive strength was defined as the minimum load at which the coating debonded and/or flaked. Measurements were performed at two sites on the inserts.
Typical re-sintering conditions, the resulting substrate surface roughness and the corresponding adhesion values are summarized in Table I. Substrate weight changes (losses) during re-sintering confirm that cobalt is being evaporated from the samples during re-sintering. The higher the weight change ratio, the greater the cobalt loss. In these examples, acceptable adhesion results were achieved at weight ratios of 1.0030 to 1.0170, in combination with surface roughnesses of 27 to 61 microinches. These weight change ratios indicate that, in substrates having about 2.7 w/o cobalt before resintering, after re-sintering, the cobalt content has been reduced to about 2.4 to 1.0 w/o. While it is desirable to increase surface roughness to achieve improved interlocking between the substrate surface and the diamond coating, the weight change ratio should preferably be as small as possible, commensurate with obtaining the desired level of surface roughness that is necessary to achieve good bonding with the coating.
In general, samples with higher substrate surface roughness exhibit higher adhesive strength. Samples sintered for only one hour at 1454° C. (2650° F.) had insufficient surface roughness, insufficient coating to substrate adhesion, and had a much smaller weight loss (i.e., cobalt loss) than the samples sintered for longer times in accordance with the present invention.
In another experiment, coated inserts prepared in a similar manner to the previous experiment were evaluated in a metalcutting test. In general, samples with a higher substrate surface roughness exhibited improved performance. In still further examples, shown in Table II, additional samples of sintered and ground Alloy B substrates and samples of sintered and ground Alloy A substrates were re-sintered as shown in Table II using a 0.5 torr nitrogen atmosphere as before. The substrate weight change ratio on samples 608A3 and 608A4 were, respectively, 1.0088 and 1.0069. The weight changes due to re-sintering in the other samples listed in Table II were not measured. As can be seen from the Table, the Alloy A substrates were subjected to two re-sintering runs to obtain the desired surface roughnesses and the desired indentation adhesion values. It is believed that longer re-sintering times are necessary to achieve equivalent surface roughnesses and indentation adhesion values to those obtained in Alloy B due to the addition of chromium (a grain growth inhibitor) and/or the higher cobalt content of Alloy A. The diamond coatings placed on these samples had a thickness of about 25 μm in the corners of the rake face (21 mg weight change is approximately equivalent to a 25 μm coating thickness on a SPGN-422 style insert).
The inventors surprisingly found that diamond coated cutting inserts in accordance with the present invention, in turning of A380 and A390 type aluminum alloys, exhibit wear lives of at least 40, and more preferably, about 60% of PCD tipped tools, fail by abrasive wear (not flaking) and have similar lifetimes and failure modes in interrupted turning of these materials, as well. This is the first time, to the inventors' knowledge, that a diamond coated cutting tool has been produced that will consistently resist flaking in interrupted turning of these materials. This allows consistent tool lives to be achieved and predicted--a step that is necessary if diamond coated tools are to be commercially competitive with PCD tipped tools. The machining test results described above were accomplished with diamond coating thicknesses of about 25 μm as measured on the rake face near the corners of an Alloy B type insert substrate.
TABLE I__________________________________________________________________________EFFECT OF RE-SINTERING ON ROUGHNESS AND ADHESION RE-SINTERING SUBSTRATE DIAMOND CONDITION SUBSTRATE SURFACE COATING INDENTATION TEMP/TIME WEIGHT CHANGE ROUGHNESS,R.sub.a WEIGHT GAIN ADHESIONSAMPLE NO. °C./MIN. RATIO** MICROINCHES mg kg__________________________________________________________________________Ground NONE 5-5 *-151624-1 1454/60 1.0016 13-14 4.58 30-451629-6 1454/60 1.0020 17-20 8.62 45-451623-3 1454/120 1.0030 27-28 8.73 60-1001628-6 1454/120 1.0073 33-39 8.96 60-601622-2 1510/120 1.0048 40-40 5.37 100-1001627-4 1510/120 1.0170 58-61 7.66 60-100__________________________________________________________________________ *spontaneous flaking **due to resintering process (weight before/weight after)
TABLE II__________________________________________________________________________ RE-SINTERING SUBSTRATE DIAMOND DIAMOND CONDITION SURFACE COATING SURFACE COATING INDENTATION TEMP/TIME ROUGHNESS, R.sub.a ROUGHNESS, R.sub.a WEIGHT GAIN ADHESIONSAMPLE NO. °C./MIN. MICROINCHES* MICROINCHES* mg kg__________________________________________________________________________608E2 1510/180 45/50 45/58 19.74 60/100608E3 1510/180 52/55 60/60 23.58 60/60608E5 1510/180 48/55 48/55 18.59 60/100608E6 1510/180 42/42 40/42 19.16 60/100608E7 1510/180 45/40 45/50 22.80 45/60608E8 1510/180 52/50 60/42 18.62 45/60608E9 1510/180 48/52 60/68 18.90 60/60608E10 1510/180 45/45 50/42 22.66 60/60608A3 1510/180 38/48 40/38 15.92 60/60608A4 1510/180 40/35 45/38 16.27 60/60608F 1510/180 + 58/48 62/52 24.55 60/60 1510/180608G 1538/120 + 42/55 45/55 19.63 45/60 1510/180__________________________________________________________________________ E = Alloy B grade starting substrate in SPGN422 style A = Alloy B grade starting substrate in TPGN322 style F & G = Alloy A grade starting substrate in SPGN422 style *first number is from near the center of the rake face, second number is from near a cutting edge
An optional, but preferred, buffing of the flank surface of the present invention is achieved by use of a rotating brush whose bristles are impregnated with diamond grit (e.g., 400 mesh grit). Suitable brushes may be purchased from Osborn Manufacturing/Jason, Inc., of Cleveland, Ohio.
Turning now to FIG. 12, if buffing is desired, the brush bristles 100 impinge on the flank surfaces 190 of the cutting tool 200. The tool 200 may or may not rotate while in contact with the brush bristles. As shown in FIG. 12, this may be accomplished by mounting the cutting insert 200 on a rotating pedestal 210 such that the insert will rotate about an axis which is perpendicular to the axis of rotation of the brush bristles 100 and allow the bristles 100 to sweep up and over each flank surface 190 (position A). Alternatively, (not shown) each insert flank side or corner may be buffed sequentially by maintaining the orientation of the insert constant (non-rotating) while being buffed, and then, when buffing is complete, indexing the insert to the next corner to be buffed.
In another alternative (shown at position B of FIG. 12), the insert 200 may be inserted, upside down, into the lower righthand quadrant of the clockwise rotating brush. In this manner, the flank surfaces 190 of the insert may be buffed without producing a rounding of the coated cutting edge 220.
As an example, several diamond coated inserts were buffed for 15 minutes using an 8 inch diameter brush impregnated with 400 mesh diamond grit rotating at a speed of 1000 rpm. The surface roughness parameters of the diamond coating were measured with a Sheffield Proficorder Spectre instrument in the as-deposited and the buffed conditions. Roughness data are listed below in Table III and show that the flank surface roughness parameters for the coatings are significantly lowered by the buffing operation. Whereas, R a measures average roughness, R tm measures peak to valley maximums, and the latter is reduced more significantly by buffing.
TABLE III______________________________________EFFECT OF BUFFING ON SURFACEROUGHNESS PARAMETERS OFDIAMOND-COATED INSERTS SURFACE ROUGHNESS PARAMETERSINSERT SURFACE R.sub.a R.sub.tmCODE CONDITION MICROINCHES MICROINCHES______________________________________A As-Deposited 51 341 Buffed 39 268B As-Deposited 91 641 Buffed 58 333C As-Deposited 40 277 Buffed 35 227D As-Deposited 88 547 Buffed 59 330E As-Deposited 44 300 Buffed 35 223______________________________________
Attempts to use brushes impregnated with silicon carbide particles were unsuccessful. Roughness parameters were unchanged after buffing. The disclosed diamond buffing process may be accomplished in shorter times by using more aggressive conditions, such as coarser diamond particles in the bristles, higher rotational speeds, etc.
Beneficial effects of the buffing operation on metalcutting performance is further demonstrated by the following experiments. One corner on each of three SPGN-422 style diamond coated inserts was buffed as described above (the inserts were not rotated during the buffing operation). The diamond coating on the remaining corners was left intact in the as-deposited condition. For comparison, a conventional PCD tool was used in the same metalcutting test. Metalcutting conditions in this turning test were as follows: workpiece material A390 aluminum (about 18% silicon), speed 2500 surface feet per minute, feed 0.005 inches per revolution, depth of cut 0.025 inches. The tools were used in sequence to make two-minute cuts until each tool failed, i.e., a wear land of 0.010 inch developed or the diamond coating was worn through to the substrate. After each two-minute cut, the workpiece surface roughness was measured with a portable profilometer. (A Federal Products Corp. Pocket Surf® model EAS-2632, which uses a diamond stylus to trace the microroughness of the surface.)
The results are summarized in Table IV and list the range of workpiece roughnesses measured during the test until tool failure. Workpiece surface finishes provided by the buffed, diamond-coated tools are clearly superior and approximate the finish provided by the PCD tool. These diamond coated tools are suitable for finish-machining operations where surface roughnesses generally less than 80 microinches are required. However, as noted in Table IV, Tool Material C, buffing can be controlled to produce workpiece surface roughnesses of less than 50 microinches, if required, the same as produced by the PCD tool.
TABLE IV______________________________________EFFECT OF BUFFING ON WORKPIECE SURFACEFINISHES PROVIDED BY DIAMOND-COATED TOOLS RANGE OF WORKPIECETOOL SURFACE ROUGHNESS, R.sub.aMATERIAL CONDITION MICROINCHES______________________________________PCD Polished 30 → 44A As-Deposited 51 → 108 Buffed 44 → 75B As-Deposited 70 → 179 Buffed 38 → 73C As-Deposited 55 → 83 Buffed 35 → 40______________________________________
Table IV illustrates that the range of workpiece roughness before and after buffing was reduced by 7-106 R a .
In another experiment, an as-deposited, diamond coated tool at failure (the coating was just worn through to the substrate after 46 minutes of total cutting time, with a wear zone measuring 0.0163 inches) produced workpiece roughnesses (R a ) ranging between 184 and 221 microinches. The wear zone on this tool was subjected to the buffing operation described above. After this treatment, the tool produced workpiece surface finishes (R a ) ranging between 60 and 67 microinches. Again, the buffing operation was beneficial to tool performance.
The inventors have found that to impart a smooth surface finish with a 400 mesh brush, the buffing time may be of the order of only a few minutes. If a coarser finish is acceptable (e.g., 120 mesh), buffing time may be reduced. Buffing may also be done in two or more steps, a first, fast, stage with a coarse (e.g., 120 mesh) brush to remove the most significant asperities, and then a second, slow, stage to provide the final desired degree of surface smoothness to the diamond coated surfaces, with fine brush (e.g, 400 mesh).
While the invention has been described in detail with respect to the most preferred embodiment, i.e., diamond coated indexable cutting inserts for use in metalcutting applications, such as turning and milling, it is not limited to only indexable cutting inserts for metalcutting.
The present invention may be applied to round tools (such as drills and end mills) and other cutting tools, which may be non-indexable. Cutting tools in accordance with the present invention may also be used to machine other materials in addition to aluminum and its alloys, such as copper, zinc and brass alloys, wood, particle board, nylons, acrylics, phenolic resin materials, plastics, composites, green ceramics and cermets, bone and teeth.
The present invention may also be used in wear parts for such applications as TAB bonders for electronic applications, and dies and punches.
The present invention may also be applied to the tungsten carbide-cobalt cemented carbide tips used in mining and construction tools, and earth and rock drilling tools.
While the best mode for carrying out the invention has been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention as defined by the following claims.
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A diamond-coated tool and a process for making them. The process includes a sintering step. In that step, a substrate is sintered in an atmosphere and for a time and at a temperature so that superficial, exaggerated grain growth is promoted that imparts a surface roughness which may serve as anchoring sites during a subsequent diamond coating step which is performed by a vapor deposition technique. The diamond-coated tool or wear part includes a large grain substrate surface, and a high bond strength between the diamond coating and the substrate surface.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2005-172678, filed on Jun. 13, 2005, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a communication control method and communication apparatus employing the method. More particularly, the invention relates to a communication control method for securing communications when an L2 loop occurs, and a communication apparatus employing the method.
[0004] 2. Description of the Related Art
[0005] In networks is known an L2 loop (broadcast storm) which is one of extremely frequent faults which may occur as a result of mal-connections of LAN cables (see, e.g., Japanese Patent Application Laid-open Publication No. 2002-252625). When this L2 loop occurs, the transmission paths are not only subjected to high loads all over the subnets, but also there appears phenomenon called black hole phenomenon by which packets are forwarded to the point where the loop is present.
[0006] Following is a description of the mechanism by which such an L2 loop occurs. FIGS. 1A and 1B are diagrams describing the L2 loop occurring mechanism.
[0007] As shown in FIG. 1A , terminal 1 broadcasts packets with the originator address of “A”, which is the MAC address of the terminal 1 , and then, the packets are forwarded by relay switches SW 1 , SW 2 and SW 3 such that the packets reach all the terminals 2 and 3 within a subnet.
[0008] At that time, the relay switches SW 1 , SW 2 and SW 3 learn “A” which is a packet issuing MAC address at a port receiving the packet. In other words, the switches learn that a terminal having the MAC address “A” is present ahead of this port. This enables each of the relay switches to determine a port to which the packet is forwarded based on the result of this learning when a packet having a destination MAC address “A” is next sent from another terminal.
[0009] However, as shown in FIG. 1B , when the cables become looped as a result of mal-connection of the LAN cables at the relay switch SW 3 for example, a broadcast packet sent from the terminal 1 loops. Thus, each time the packet sent from the terminal 1 loops at the relay switch SW 3 , the packet from the terminal 1 is sent from the looping point such that the relay switches SW 1 , SW 2 and SW 3 within the subnet erroneously learn the MAC addresses as the terminal 1 of the MAC address “A” being present at the looping point, based on the same principle as that used in the previous description.
[0010] As a result, even though another terminal intends to send a packet destined for the terminal 1 , the packet disappears into the looping point formed at the relay switch SW 3 , and therefore a packet cannot normally arrive at the terminal 1 , disabling the communication to the terminal 1 .
[0011] Since apparatuses, personal computers and routers using Windows (OS provided by Microsoft Corp.) often send a broadcast packet, there occurs phenomena that the terminal which has once sent the broadcast packet becomes prevented from performing communications within the subnet.
[0012] Although Japanese Patent Application Laid-open Publication No. 2002-252625 discloses a technique for detecting the point where such a loop occurs, there has hitherto been no technique for correcting the addresses which have erroneously been learned after the occurrence of the loop. It has hitherto been difficult to communicate with a terminal lying within the loop subnet unless the loop is fundamentally ceased by disconnecting the loop occurring source through physical works such as removing the cables.
[0013] Such a disconnection work has led disadvantageously to high time and human costs due to the need to identify the looping point.
SUMMARY OF THE INVENTION
[0014] It is therefore an object of the present invention to provide a communication control method enabling communications within a subnet by securing communication paths between hosts within a loop subnet or between a host within the loop subnet and a host outside the loop subnet even though the L2 loop broadcast storm occurs.
[0015] In order to achieve the above object, according to an aspect of the present invention there is provided a communication control method for recovering communication failures caused by a packet loop that occurs as a result of L2-level misconnection at relay switches in a communication system where data transmission/reception is carried out between a plurality of end hosts connected to the relay switches within a subnet, the method comprising the steps of consecutively sending packets each having, as its originator address, a MAC address other than an originator MAC address of an end host desired to be communicated making up the subnet; thereby stopping the packet loop; and then sending packet data using, as a destination MAC address, a MAC address of a destination end host. The destination of the packets to be consecutively sent may be a broadcast address. The packets to be consecutively sent may be directed to a unicast address using as a destination an address not existing in the subnet. The packets to be consecutively sent may be multicast using as an originator MAC address an address not existing in the subnet. The MAC address other than an originator MAC address of an end host desired to be communicated may be a MAC address other than an existent MAC address acquired by monitoring communication and an existent MAC address identified in advance. The communication control method may further comprise the step of setting a MAC address not existing within the subnet as the originator address to consecutively send the packets to be broadcast. The communication control method may further comprise the steps of setting an MAC address not existing within the subnet as the originator address; sending packets whose destination is a broadcast address, to which the end host desired to be communicated respond in unicast; and thereby allowing the relay switch within the subnet to correctly learn the MAC address of the end host. The communication control method may further comprise the steps of setting an MAC address not existing within the subnet as the originator address; sending unicast packets whose destination is an address not existing within the subnet; and thereby allowing the relay switch within the subnet to correctly learn the MAC address of the end host. The communication control method may further comprise the steps of setting an MAC address not existing within the subnet as the originator address; sending packets whose destination is a multicast address, to which the end host desired to be communicated respond in unicast; and thereby allowing the relay switch within the subnet to correctly learn the MAC address of the end host.
[0016] In order to attain the above object, according to another aspect of the present invention there is provided a communication control method for recovering communication failures caused by a packet loop that occurs as a result of L2-level misconnection at relay switches in a communication system where data transmission/reception is carried out between a plurality of end hosts connected to the relay switches within a subnet, the method comprising the steps of consecutively sending packets each having, as its originator address, a MAC address of an end host desired to be communicated; thereby causing to delete a MAC learning table of the relay switch in the event that broadcast packets have the same originator address; and sending packet data using, as a destination MAC address, a MAC address of a destination end host.
[0017] In the above aspect, the communication control method may further comprise the steps of sending ARP (Address Resolution Protocol) broadcast packets; and thereafter sending packets intended to correct mis-learning to acquire a MAC address from an IP address of the end host. The consecutive sending of the packets may be executed by an apparatus disposed at a remote site.
[0018] Thus, even though the L2 loop broadcast storm occurs, the communication paths are secured between the hosts within a loop subnet or between a host within the loop subnet and a host outside the loop subnet, enabling the communications within a subnet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The above and other objects, aspects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which:
[0020] FIGS. 1A and 1B are explanatory Views of the mechanism with which an L2 loop (broadcast storm) occurs;
[0021] FIG. 2 shows an exemplary configuration of a subnet for describing an embodiment of the present invention implementing the principle of the invention;
[0022] FIG. 3 shows an exemplary functional configuration of an invention apparatus 100 according to the present invention;
[0023] FIG. 4 shows an operation flow of the invention apparatus 100 corresponding to the embodiment of FIG. 2 ;
[0024] FIG. 5 shows signal sequences in the subnet;
[0025] FIG. 6 shows an exemplary apparatus configuration of the invention apparatus 100 of a second embodiment;
[0026] FIG. 7 shows an operation flow of the invention apparatus 100 of the second embodiment;
[0027] FIG. 8 shows a signal sequence flow of a third embodiment;
[0028] FIGS. 9A and 9B show packet formats;
[0029] FIG. 10 shows signal sequences corresponding to a fourth embodiment;
[0030] FIG. 11 shows an exemplary functional configuration of the invention apparatus that is applied to a fifth embodiment;
[0031] FIG. 12 is an explanatory view describing the concept of mis-learning in a sixth embodiment; and
[0032] FIG. 13 shows signal sequences corresponding to the sixth embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] Embodiments of the present invention will now be described with reference to the accompanying drawings. It is to be appreciated that the embodiments are given for the purpose of understanding the present invention and that the technical scope of the present invention is not intended to be limited thereto.
[0034] The fundamental principle of the present invention lies in correcting the erroneous address learning upon the loop occurrence by consecutively sending packets from remote. This enables communications with terminals within a subnet without disconnecting the loop occurring source and enables remarkable reduction of the time and human costs for recovering the communications, which have hitherto been needed.
[0035] It is thus sufficient that there exist no looped packets having MAC addresses of both communication sender and destination terminals as source addresses, and hence the principle of the present invention lies in that packets meeting these conditions are consecutively broadcast for replacement with intentionally looped packets.
[0036] According to the present invention, at relay switch ports making up a loop, packets are consecutively input and while simultaneously existing loop packets are also input, whereupon two (2) inputs are present on a single output port. Since this consecutively occurs, input or output queues overflow, as a result of which looped packets are discarded by the queue overflow at the relay switch, enabling the state where only packets sent according to the present invention are becoming looped to be created.
[0037] The above principle prevents packets causing mis-learning of the MAC addresses from being sent from the loop, enabling the communication with the terminals (end hosts) within a subnet.
[0038] FIG. 2 shows an example of the subnet configuration for describing the present invention implementing the above principle. A relay switch SW 1 connects to end hosts 200 A and 200 B and to a communication apparatus 100 (hereinafter referred to as the invention apparatus 100 ) to which the method of the present invention is applied as a concept of one host, for recovering the communications at the L2 looping. The state is shown where a cable-connected relay switch SW 2 is ahead of the relay switch SW 1 with L2 loop occurring as a result of cable mal-connection at the relay switch SW 2 .
[0039] First Embodiment FIG. 3 is a diagram showing an example of the functional configuration of the invention apparatus 100 according to the present invention. FIG. 4 is an operation flow of the invention apparatus 100 corresponding to the embodiment of FIG. 3 , and FIG. 5 is a diagram showing sequences of signals in the subnet of FIG. 2 .
[0040] Reference will be made to these figures to describe a first embodiment of the present invention.
[0041] The invention apparatus 100 has a function of sending specified packets (Ether header destination address, originator address, protocol, payload corresponding to the protocol, etc.) In a specified number of times and sends consecutively into the subnet packets that have been broadcast with the MAC addresses not existing in the subnet as the originator addresses. This presents an effect of stopping the end host MAC address to be communicated being erroneously learned by the relay switches SW 1 and SW 2 .
[0042] In the functional block of the invention apparatus 100 shown in FIG. 3 , an input unit 101 acquires an MAC address (=MC) of the invention apparatus 100 (step S 1 of FIG. 4 ) and further acquires control parameters such as the number of packets sent, the size, header and payload information thereof (step S 2 ). Then, a packet transmission unit 102 creates packets having the MAC address (=MC) as the originator address in accordance with the input control parameters and sends the packets through a network interface (step S 3 ).
[0043] Delivered to the packet transmission unit 102 as the control parameters of the invention apparatus 100 are protocol, destination MAC address, originator MAC address, packet length and parameters proper to the upper protocol of the MAC packet. These parameters of the packets to be sent may all be altered, may be default values or may be unalterable at fixed values. The packet transmission unit 102 instructed to send packets creates the packets based on the control parameters and send them via the interface 103 to a network 110 . If an instruction to stop is given, the packet transmission unit 102 stops the transmission of the packets.
[0044] In this case, each packet is configured such that the destination address and originator address are written to its header portion. For example, using the default parameters from the input unit 101 , the packet transmission unit 102 sends 10,000 packets for example with ARP (Address Resolution Protocol) request frame for Ethernet longest packet of 1,514 bytes, with the destination MAC address in the form of FF-FF-FF-FF-FF-FF MAC broadcast, the originator address being the MAC address of the invention apparatus 100 , the address required by the ARP being IP address(=IPC) of the invention apparatus 100 . This enables the looped packets to be replaced with packets sent by the invention apparatus 100 .
[0045] For example, a case is contemplated in FIG. 2 where a broadcast (BC) packet PKT 1 sent from the end host 200 A loops at the relay switch SW 2 , with the result that the MAC address (=MA) of the end host 200 A is continuously erroneously learned at the relay switches SW 1 and SW 2 (see P 1 of FIG. 5 , where MA is the looping direction).
[0046] In this state, the invention apparatus 100 issues a large number of broadcast packets PKT 2 (see P 2 of FIG. 5 ). This results in the looping direction represented by the MAC address (=MC) of the invention apparatus 100 to clear away the looped packets PKT 1 sent from the end host 200 A. Thus, there can be stopped the state where the packets PKT 1 become looped, which may cause the mis-learning.
[0047] It is to be noted that this state merely stops the looping of the packets from the end host 200 A causing the mis-learning and that the mis-learning remains unsolved.
[0048] Afterwards, for example, the end host 200 A that is a communication originator sends a unicast packet PKT 3 to the end host 200 B not performing any voluntary mis-learning. This allows the address of the end host 200 A to arrive at the end host 200 B while being correctly learned on the relay switch SW 1 (see P 4 of FIG. 5 ).
[0049] As a result, communication from the end host 200 B to the end host 200 A also arrives at the end host 200 A through a path where a response packet PKT 4 is correctly learned (see P 5 of FIG. 5 ).
[0050] The above mechanism ensures the correction of mis-learning such that communication between the end hosts 200 A and 200 B is enabled even in the state where the L2 loop occurs.
[0051] In this case, available as the destination MAC address of the MAC packet PKT 2 to be sent is a multicast address of the MAC packet or a unicast address of the MAC packet not used in the subnet, in addition to the broadcast (=BC) address of the MAC packet.
[0052] The originator address of the MAC packet to be sent need not be the MAC address (=MC) of the invention apparatus 100 but can be any address other than the MAC address possessed by the end host to be communicated. The originator address may be a unicast address of the MAC packet not used in the subnet, a unicast address of the MAC packet being used in the subnet, a MAC broadcast address, or a MAC multicast address.
[0053] If, for example, ARP is sent with the originator address in the form of any MAC address not existing in the subnet, then in case the packets sent from the invention apparatus 100 become looped, the sent packets will be continued to be resent from the looping point to the overall areas of the subnet. At that time, the MAC address learned at each of the relay switches is an earlier created MAC address of a really non-existent end host, and hence no influence can be imparted to any really existent hosts inclusive of the invention apparatus 100 even though the MAC address is erroneously learned at each relay switch as the MAC address being present at the looping point.
[0054] The sent protocol is not intended to be limited to the ARP, and any upper protocols are also available such as IP (Internet Protocol), ICMP (Internet Control Message Protocol) and IPX (Internet Packet Exchange). Alternatively, there may also be used presently unused protocol that is not interpretable by the end host or normally uninterpretable packet. The sent packet length and the number of packets to be sent can be any values as long as packets capable of being actually sent over the network are used.
[0055] The invention apparatus 100 need not necessarily be disposed within the looping subnet. For example, in the case where it is disposed within a network different from the looping subnet, the same applies thereto by consecutively sending the ICMP Echo Request having as its destination the IP broadcast address destined for the looping subnet, or by consecutively sending packets to which routers such as RIP within the looping subnet such as RIP respond with broadcast packets or by consecutively sending packets to which the end host within the NetBIOS looping subnet respond with the broadcast packets. The invention apparatus 100 may send a MAC packet with a VLAN (Virtual Local Area Network) tag attached thereto such that the packets can be sent to any appropriate subnet by specifying VLANtag used in the looping subnet.
[0000] Second Embodiment
[0056] A second embodiment will hereinafter be described where the looped reception packets are sent while being monitored.
[0057] The configuration of the subnet in the second embodiment is as shown in FIG. 2 . FIG. 6 shows an example of the apparatus configuration of the invention apparatus 100 according to the second embodiment. FIG. 7 is a flowchart of the operation thereof.
[0058] In the exemplary configuration of the invention apparatus 100 show in FIG. 6 , the input unit 101 acquires check parameters and the packet transmission unit 102 sets the number of packets to be sent, the size and destination addresses thereof (step S 11 ).
[0059] An address set H of a host to be communicated is acquired or set (step S 12 ). A MAC address list is then acquired including the MAC address of the invention apparatus 100 and MAC addresses on-subnet(step S 13 ).
[0060] An address X is then created that does not appear in the thus acquired MAC address list (step S 14 ). 5,000 ARP packets are issued for an example, with the originator address in the form of the thus created address X (step S 15 ).
[0061] On the contrary, a monitor unit 106 records therein all of the originator addresses of the Ethernet packets received during a certain period of time, e.g., for one (1) second. After the reception of one (1) second, a set S of the received originator MAC addresses are recorded therein (step S 16 ).
[0062] Comparison is then made between the set S of the originator MAC addresses of the packets received during the period and the address set H of the host to be communicated (step S 17 ). If the address set H is not included in the set S in this comparison (N of step S 17 , then the really existent end hosts 200 A and 200 B are not subjected to any influence of the mis-learning such that communication therewith becomes enabled, ending the procedure. If included (Y of step S 17 ), then the packet sending with X as the originator address (S 15 ) is continued until the set H becomes not included in the set S.
[0063] Although in this embodiment the sending operation is repeated infinitely as long as even only one MAC address of the really existent end host is included in the originator MAC addresses of the received packets (the set H is included in the set S: Y of step S 17 ), the sending operation may be stopped when reaching the limited number of times.
[0064] Alternatively, the receiving operation need not necessarily be continued during a certain period of time. That is, each time the packet is received, comparison may be made at step S 17 of whether the originator address matches the MAC address of the end host really existing within the subnet. If affirmative, the packet with any non-existent MAC address as the originator address may consecutively be issued in the same manner as the first embodiment.
[0065] Alternatively, the received originator MAC address of the broadcast packet may first be acquired and recorded received by the monitor unit 106 during a certain period of time. Then, in case the MAC address of the end host to be communicated matches the received originator MAC address recorded by the monitor unit 106 , the above sending operation may be executed such that the sending operation may not be executed unless the MAC address of the end host to be communicated is erroneously learned. This prevents the network from being subjected to any unnecessary load.
[0066] In case the broadcast packet whose originator address comes from the end host to be communicated is not currently looped but was looped in the past, the MAC address may possibly be erroneously learned. For this reason, the above sending operation (step S 15 ) may be executed in case the end host cannot be communicated when it is verified that no loop occurs for the certain period of time.
[0067] Thus, with the above state, by sending and receiving the packets intended for communication between the end hosts, the communication can advantageously be recovered even though any mis-learning takes place.
[0000] Third Embodiment
[0068] Description will be made of a third embodiment where the host causes responding broadcast packets to loop.
[0069] The third embodiment is characterized by stopping all of the states where the packets causing mis-learning are looped and correcting the mis-learning to ensure normal learning. The network configuration is as shown in FIG. 2 , and FIG. 8 is a signal sequence flow in this embodiment.
[0070] FIGS. 9A and 9B show formats of the MAC packet, and more specifically the MAC header has three fields consisting of destination MAC, originator MAC and type. In the diagrams showing the associated MAC packet formats besides FIGS. 9A and 9B , the type of the MAC header is not shown for the purpose of simplification.
[0071] First, in conformity with the first and second embodiments, the invention apparatus 100 consecutively issues PAC packets PKT 2 of the format shown in FIG. 9A to obtain the state where there disappears a loop LP 1 caused by the MAC packet PKT 1 originating from the end host 200 A to be communicated (P 1 ). At this time, a loop LP 2 caused by the MAC packet PKT 2 issued from the invention apparatus 100 remains not disappeared for a while.
[0072] While an ARP request packet is then issued in this embodiment, the destination IP address requested is set to an IP address (=IPA) of the end host 200 A within the ARP request packet of the format structure shown in FIG. 9B , with requester IP and MAC addresses within the ARP request packet being set to an IP address (=IPX) and a MAC address (=MX) that are not used in the subnet in the same manner as the second embodiment. A single or a plurality of packets are then sent with the ARP requesting originator MAC address within the MAC header portion being set to MX and with the destination MAC address set to a broadcast MAC address (=BC). This enables the sent ARP request packet to be broadcast while looping (LP 3 ).
[0073] When receiving a single ARP request packet, the end host 200 A sends a single ARP response packet to the destination MAC address (=MX) (P 2 ).
[0074] This MAC address (=MX) is erroneously learned by all of the relay switches SW 1 and SW 2 as long as it exists at the looping point, as a result of which the ARP response is relayed toward the loop so that the MAC address (=MA) of the end host 200 A is normally learned at each relay switch along the relay path (P 3 ).
[0075] In the above state, by sending and receiving the packets PKT 3 and PKT 4 intended for communication between the end hosts 200 A and 200 B, the communication can be recovered even when the mis-learning occurs (P 4 ). Since the end host 200 A continues to respond to the ARP resulting in a high load, the loop packet may be replaced with one not subjecting the host to such a high load after the normal learning so that the response is ceased. This approach is applicable not only to the ARP but also to various protocols such as IP multicast and IP broadcast protocols as long as the end host responds to the broadcast packet.
[0000] Fourth Embodiment
[0076] The feature of a fourth embodiment lies in that mis-learning is corrected without stopping the packets causing mis-learning from looping.
[0077] FIG. 10 shows sequences of signals corresponding to such a fourth embodiment. In certain type of Ethernet relay switches, when packets having the same originator address (in this case, MAC address (=MA) of the end host 200 A) often arrive at different ports (P 1 -P 2 ), the ports learning the address MA are frequently changed and the normal learning is regarded as being difficult so that the corresponding MAC addresses are temporarily deleted from the learning table, with the result that the address MA becomes unlearned (P 3 ).
[0078] In that event, when a packet directed to the end host 200 A intended for communication arrives at a relay switch, the packet is regarded as destination unknown due to its unlearned MA, and is broadcast to all the ports in spite of the unicast packet (P 4 ). This enables the packet to be forwarded to correct ports as well although normal learning is not achieved, resulting in the same effect as obtained when the mis-learning has been corrected.
[0079] In order to present such a state, consecutive sending has only to be made of MAC packets having the address MA as the originator address. By way of example, in the third embodiment, the same effect can be obtained as the case where the mis-learning has been corrected at the relay switch (see P 3 of FIG. 8 ) by allowing the end host to respond to the packets consecutively broadcast by the loop, instead of completely stopping the packets causing the mis-learning from looping in advance.
[0080] As alternative, the invention apparatus 100 may be disposed in a subnet different from the looping subnet such that unicast packets are consecutively sent to a host within the looping subnet by way of a router that is a gateway to the looping subnet. Even though a broadcast packet sent from the router loops, this embodiment temporarily allows the packet directed to the router to be normally forwarded from the host, enabling communication with the invention apparatus 100 via the router.
[0081] With the above state, by sending and receiving the packets intended for communication between the end hosts, such an effect can be obtained that the communication is recovered even when the mis-learning takes place. In case of the above example, the destination address need not necessarily be the unicast address but instead can be any addresses such as the MAC broadcast address and MAC multicast address.
[0000] Fifth Embodiment
[0082] Description will be made of a fifth embodiment where the address mis-learning is stopped and corrected remotely by allowing an end host belonging to a remote subnet different from a looping subnet to remotely control the invention apparatus within or outside the looping subnet.
[0083] FIG. 11 shows an example of the functional configuration of the invention apparatus, which is applied to such a fifth embodiment. To and from the invention apparatus 100 previously disposed within a looping subnet as an end host within the subnet, a remotely existing end host sends a control message through communication means such as telnet or SNMP (Simple Network Management Protocol) and receives the control message through the packet reception unit 105 thereof. The invention apparatus 100 interprets the received control message as input of the control parameter through a remote control unit 104 thereof to effect the same operations as those in any of the first to fourth embodiments. No specific limitations are imposed on the control message as long as any existing communication means are used. For example, in case of using TCP/IP, the socket communication inclusive of telnet or SNMP may carry the control message.
[0084] In the event of the invention apparatus 100 acting as a host connecting to a looping subnet, as shown in FIG. 11 , the interface 103 sending and receiving a control message is identical to the interface sending a broadcast packet intended for stopping and correcting the mis-learning. Alternatively, a plurality of physically different interfaces may be employed as long as they operate as a logically single end host.
[0085] The interface may be implemented as part of the logical function of a router (gateway) at the boundary via which the looping subnet connects to an external network. In this case, the network interface 103 of FIG. 11 is divided into two portions, i.e., the subnet side and the external network side although as the logical function the router-directed packets are once received by the packet reception unit 105 , effecting substantially the same subsequent operations.
[0086] The invention apparatus 100 need not necessarily be disposed within a looping subnet. The same effect can be obtained by, as in the first embodiment, by consecutively sending ICMP Echo Request packets whose destination is IP broadcast address from the outside of the subnet to the interior of the looping subnet.
[0000] Sixth Embodiment
[0087] The feature of a sixth embodiment lies in that the MAC address can be acquired from the IP address upon the occurrence of loop.
[0088] FIG. 12 is an explanatory view of the concept of mis-learning in the sixth embodiment. FIG. 13 shows signal sequences corresponding to the sixth embodiment.
[0089] As is apparent from FIG. 12 , when the invention apparatus 100 intends to communicate with another end host 200 within the subnet upon the occurrence of loop, the invention apparatus 100 needs to send an ARP request to acquire a MAC address (=MA) of the end host 200 even if it knows the IP address (=IPA) of the end host 200 .
[0090] However, when issuing a broadcast packet such as the ARP request upon the occurrence of loop (P 1 ), the packet becomes looped leading to mis-learning of the MAC address (MC) of the invention apparatus 200 (P 2 ). This prevents a response to the ARP request to normally return to the invention apparatus 100 , with the result that the MAC address (MA) of the end host 200 cannot be acquired resulting in the communication disabled.
[0091] The state at that time will hereinafter be described in detail. As a result of looping of an ARP request (I) from the invention apparatus 100 , the end host 200 often receives the ARP request originating from the invention apparatus and, for each reception, issues an ARP response (II). However, the MAC address (=MC) of the invention apparatus 100 is erroneously learned as being present at the looping point by the switches SW 1 and SW 2 .
[0092] For this reason, all the ARP responses (II) sent from the end host 200 are consequently forwarded to the looping point so that mis-learning at the looping point leads to ARP response packets becoming looped at the looping point (P 3 ).
[0093] Ordinarily, as shown in FIG. 12 , unicast packets are looped in the opposite direction (broken line of FIG. 12 ) to the direction (solid line of FIG. 12 ) where the broadcast packet turns. Thus, as shown in FIG. 13 , the ARP request packets are caused to disappear from the loop by sending a large number of broadcast packets (III) having a non-existent MAC address (=MX) as the originator MAC address, as in the first or third embodiment.
[0094] When the invention apparatus 100 then issues any MAC packet (IV) with MC of the invention apparatus as the originator MAC address and with MX as the destination MAC address as in the third embodiment for example, mis-learning at the switches SW 1 and SW 2 is corrected based on the principle of the third embodiment. As a result, the looped ARP response packet (II) sent from the end host 200 is forwarded toward the invention apparatus 100 which finally receives the ARP response to acquire the MAC address (=MA) of the end host 200 (P 5 ).
[0095] Thus, even in the event of looping, the MAC address of the end host 200 can be acquired using the ARP protocol.
[0096] As set forth hereinabove based on the embodiments in conjunction with the accompanying drawings, even when the L2 loop broadcast storm takes place, the present invention secures the communication path between the hosts within a looping subnet or between a host within the looping subnet and a host outside the looping subnet, enabling the communication within the subnet.
[0097] This ensures reliability of the communication qualities, contributing to industry to a great extent.
[0098] While the illustrative and presently preferred embodiments of the present invention have been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed and that the appended claims are intended to be construed to include such variations except insofar as limited by the prior art.
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Disclosed is a communication control method for recovering communication failures caused by a packet loop that occurs as a result of L2-level misconnection at relay switches in a communication system where data transmission/reception is carried out between a plurality of end hosts connected to the relay switches within a subnet. The method includes the steps of consecutively sending packets each having, as its originator address, a MAC address other than an originator MAC address of an end host desired to be communicated making up the subnet; thereby stopping the packet loop; and then sending packet data using, as a destination MAC address, a MAC address of a destination end host.
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This is a divisional application of U.S. patent application Ser. No. 08/222,776 filed on Apr. 4, 1994, now U.S. Pat. No. 5,480,744, and assigned to Motorola, Inc.
TECHNICAL FIELD
This invention relates to electrochemical charge storage materials, and rechargeable electrochemical cells using such materials.
BACKGROUND
There has recently been a great deal of interest in developing better and more efficient materials for storing energy for applications such as radio communication, satellites, portable computers, and electric vehicles, to name but a few. Accordingly, there have been recent concerted efforts to develop high energy, cost effective battery cells having improved performance characteristics. Electrochemical battery cells are preferred and hence are widely used in these applications since the chemical reactions which take place in the cells can be converted into useful electrochemical energy.
An electrochemical battery cell uses its reactive components, namely the anode and cathode, to generate an electric current. The electrodes are separated from one another by an electrolyte which maintains a simultaneous flow of ionic conduction between the two electrodes. Electrons flow from one electrode through an external circuit to the other electrode completing the circuit. Rechargeable, or secondary, cells are more desirable than primary (non-rechargeable) cells since the associated chemical reactions are reversible. Accordingly, electrodes for secondary cells must be capable of being regenerated (i.e., recharged) many times. The development of advanced rechargeable cells depends on the design and selection of appropriate materials for the electrodes and the electrolyte.
Currently, materials selected for use as the anode in rechargeable electrochemical cells are fairly limited. Typically, most rechargeable electrochemical cells use either cadmium or a combination of three or more materials in a so-called metal hydride system, as the anode. However, both of these commonly used systems have shortcomings. For example, cadmium while widely accepted in the marketplace, has certain environmental issues associated with it. Specifically, cadmium is a highly toxic material and is difficult to dispose of. In fact, several countries have recently adopted legislation aimed at eliminating the use of cadmium in rechargeable cells.
Metal hydrides are environmentally benign, but have certain technological problems relating to performance. For example, cycle life (i.e. the number of times the cell can be discharged and charged) in the best metal hydride systems is typically less than 500 cycles, and normally approximately 300 cycles. In addition to relatively short cycle life, other problems such as short shelf life, hydrogen outgassing, and high internal pressures are inherent in the system and are difficult to overcome.
Accordingly, there exists a need to develop a new electrode material for rechargeable electrochemical systems, which is environmentally friendly, yet overcomes the limitation of prior art systems.
SUMMARY OF THE INVENTION
In accordance with the invention there is provided a multi-component material for reversibly electrochemically storing and releasing an electrical charge. The material consists of bismuth and at least one modifier element. The modifier element is selected from the group of materials consisting of carbon, nickel, iron, oxygen, hydrogen, sulfur, phosphorus, fluorine, chlorine, bromine, iodine, manganese, magnesium, tin, cobalt, aluminum, zinc, copper, graphite, teflon, and combinations thereof.
Also according to the invention there is provided an electrode and an electrochemical cell, such as a battery or a pseudocapacitive device fabricated with an electrode having the material described hereinabove.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of an electrochemical cell employing a bismuth containing electrode in accordance with the present invention;
FIG. 2 is a plot of charge/discharge curve for an electrode in accordance with the instant invention;
FIG. 3 is a cyclic voltammagram (CV) for a Bi/C electrode in accordance with the instant invention;
FIG. 4 is CV for a Bi/C electrode, taken at the 10th, 2000th and 3000th cycle in accordance with the invention;
FIG. 5 illustrates the electrode capacity and utilization versus cycles for a Bi/C electrode in accordance with the invention.
FIG. 6 is a cyclic voltammagram illustrating the results for a Bi 2 O 3 /C electrode in accordance with the instant invention; and
FIG. 7 is a cyclic voltammagram illustrating results for a Bi/Fe/C electrode prepared in accordance with the instant invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
While the specification concludes with claims defining the features of the invention that are regarded as novel, it is believed that the invention will be better understood from consideration of the following description in conjunction with the drawing figures in which like reference numerals are carried forward.
The battery of the present invention is a basic and unique approach to the problem of efficient electrical energy storage. The charge storage materials described herein have obtained relatively high density energy storage, efficient reversibility, and high electrical efficiency, without substantial structural change. The materials also have long cycle life and deep discharge capability. The improved, rechargeable, charge storage material includes bismuth and at least one modifier. The modifier may be selected from the group of materials including oxygen, hydrogen, sulfur, phosphorous, fluorine, chlorine, bromine, iodine, carbon, iron, manganese, magnesium, tin, cobalt, aluminum, zinc, copper, graphite, teflon, and combinations thereof.
The rechargeable charge storage material may have the following formula:
Bi.sub.x X.sub.y M.sub.z
wherein Bi is bismuth, X is a first modifier selected from the group of oxygen, hydrogen, sulfur, phosphorus, fluorine, chlorine, bromine, iodine, carbon, or combinations thereof; M is a modifier selected from the group of C, Ni, Fe, Mn, Mg, Sn, Co, Al, Zn, Cu, graphite, teflon and combinations thereof. x, y, and z identify the amount of each component in the material, and are typically in the following ranges:
x is between 1 and 4;
y is between 0 and 7;
z is between 0 and 5.
Employing a bismuth and modifier electrode as described hereinabove, the electrode reaction at the anode of an electrochemical cell would be as follows:
Bi.sub.2 O.sub.3 +3H.sub.2 O+6e.sup.- ⃡2Bi+6OH.sup.-
or
Bi(OH).sub.3 +3e.sup.- ⃡Bi+3OH.sup.-
Referring now to FIG. 1, there is illustrated therein an electrochemical cell 10 including an anode 20 in accordance with the instant invention, a cathode 22 and an electrolyte 24 disposed there between. The electrochemical cell 10 includes an anode 20 having the chemical composition Bi x X y M z wherein X and M are modifier elements such as those described above, and x, y, and z specify the relative amount of each component in the material. The other electrode, i.e., the cathode 30, may be fabricated of materials electrochemically appropriate for use in an electrochemical cell having a bismuth-based anode. Examples of these materials include: NiOOH, AgO, PbO 2 , Br 2 , O 2 and combinations thereof.
Operatively disposed between the anode 20 and the cathode 22 is an electrolyte 24. The electrolyte may be either an aqueous or non-aqueous electrolyte and may also function as a separator to physically isolate the anode and cathode from one another. Examples of appropriate aqueous electrolytes for use in this system include KOH, NaOH, Na 2 CO 3 , NaCl, H 2 SO 4 , KF and combinations thereof. Examples of appropriate non-aqueous electrolytes for use in this system include LiAlCl 4 , LiClO 4 , LiPF 6 , propylene carbonates, ethylene carbonates and combinations thereof. In cases in which the electrolyte is an aqueous electrolyte, a separator 25 may also be necessary in order to isolate the anode and cathode from one another. In this instance, an appropriate separator may be cellophane, woven or filtered nylon, polyvinyl acetate (PVA), microporous polypropylene, and combinations thereof.
Preparation of a bismuth-based electrode as contemplated herein begins by mixing operative amounts of a bismuth-containing precursor, such as Bi powder, with a sufficient amount of a modifier or binder material, such as, for example, a graphite powder or teflon suspension in an appropriate aqueous solution. The resulting paste may then be rolled to an appropriate thickness and dried. The powder sheet may then be pressed on to a nickel mesh, or other current collector. Preparation of the charge storage material may be better understood from the following examples.
EXAMPLE I
An electrode in accordance with the instant invention was prepared as described below: 1.20 grams of bismuth powder (99.99% Adrich, -100 mech) was mixed with 1.20 grams of carbon in the form of graphite powder (LONZA, KS-6, average size is 6 μm). Thereafter, 0.20 grams of teflon suspension (Dupont 60%) and a small amount of a water/isopropanol (3:1) solution was added to the powder mixture. The resulting paste was rolled out to a thickness of approximately 0.4 mm. The teflon-bonded Bi/C powder sheet was dried in air, at room temperature for approximately 12 hours. The material was then cut into small pieces of approximately 1 cm 2 each. The weight of each of two samples was approximately 0.1659 g, with 0.075 grams of Bi. The two samples were then pressed onto a nickel mesh (Exmit, NI 5.5-4/OFA) using a lab press. The nickel mesh served as the counter electrode, with the bismuth-based electrodes serving as the working electrode, and Hg/HgO as the reference electrode. A 30% KOH solution was used as the electrolyte. A large volume fraction of graphite was used in the electrode to achieve fast potential sweep rates, however, it is to be understand that much lower graphite contents could also be used.
Referring now to FIG. 2, there is illustrated therein constant current discharge curves 30, 32, & 34 and charge curves 36, 38, 40 showing experimental results for the Bi/C electrode at current densities: 0.05 A cm -2 (0.67 A/g Bi), 0.1 A cm -2 (1.33 A/g Bi), and 0.4 A cm -2 (5.3 A/g Bi) for curves 30 and 36, 32 and 38, and 34 and 40 respectively. These results indicate that the Bi electrode has a very flat discharge/recharge curve over a full potential range. This will result in a very stable working potential (about -0.5 V vs. Hg/HgO at 0.1 A cm -2 ) for the total three electron discharge. The small gap (about 0.2 V) between charge and discharge curves in FIG. 2 suggests the low polarization character for the Bi electrode. Another important characteristic of the bismuth-based electrode is its capability for high rate charge and discharge, over 5 A/gram of Bi as shown in FIG. 2.
FIG. 3. shows cyclic voltammagram (CV) experimental results for the Bi/C electrode at a potential sweep rate of 1 mV/s. The peak area for both cathode and anode directions is substantially the same. This result suggests that the Bi-based electrode has a substantially 100% current efficiency and that there is no hydrogen gassing such as occurs in a metal hydride electrode. This is a unique characteristic which yields a much simpler cell structure than traditional Ni/Cd and Ni/MH batteries.
EXAMPLE II
A second example in which a Bi/C electrode was prepared is described herein. Electrode fabrication began by mixing 0.1 grams of Bi powder (99.99% Aldrich, -100 mesh) with 0.90 grams of graphite powder (LONZA, KS-6). Thereafter, 0.085 grams of teflon suspension (Dupont, 60%) and a small amount of water/isopropanol (3:1) solution was added to the powder mixture. The Bi/C electrode (contained about 0.0090 grams of Bi) and electrochemical cell were made according to the procedure as described hereinabove with respect to Example I. A large volume fraction of graphite was used in the electrode to achieve fast potential sweep rates, however, it is to be understood that much lower graphite contents could also be used (for the same reason, a large volume fraction of graphite was also used in Examples III and IV).
FIG. 4 shows CV experimental results at the 10th (line 42), 2000th (line 44) and 3000th (line 46) cycles, respectively, for the Bi/C electrode at a potential sweep rate of 5 mV/s in 30% KOH solution. FIG. 5 shows the electrode capacity (Coulomb) and utilization (%) vs. cycle number plot for the Bi/C electrode. The utilization results are calculated based on three electron transfer per Bi atom.
The Bi/C electrode was cycled 5500 cycles without degradation (see FIG. 5). During the first 2000 cycles, the charges associated with the electrochemical reaction increased in both cathodic and anodic directions, and leveled off thereafter. The percent utilization increased from about 15% to over 50% within this initial 2000 cycles period. It is hypothesized that this conditioning period appeared because the size of bismuth powder used in the present example was fairly large, approximately 150 μm (-100 mesh), therefore, it took a large number of cycles to establish an equilibrium condition between bismuth and its reaction product. This hypothesis was confirmed by the experiments described in Example III, in which, a much smaller powder size (about 1.9 μm) of Bi 2 O 3 was used and utilization is over 90% from the first cycle.
A very long cycle life (>5000) is one of the unique aspects of a bismuth anode. It is a great improvement over the current rechargeable anodes, e.g. Cd and MH, which are limited to a few hundred cycles.
EXAMPLE III
An electrode in accordance with the instant invention was prepared by mixing 0.1 grams of Bi 2 O 3 powder (99.9% FERRO, average size 1.9μ) with 1.0 grams of carbon in the form of graphite powder (LONZA, KS-6). Thereafter, 0.085 grams of teflon suspension (Dupont 60%) and a small amount of a water/isopropanol (3:1) solution was added to the powder mixture. The resulting paste was rolled out to a thickness of approximately 0.4 mm. The teflon-bonded Bi 2 O 3 /C powder sheet was dried in air, at room temperature for approximately 12 hours. The material was then cut into small pieces of approximately 1 cm 2 each. The weight of the two samples was approximately 0.1034 g, with 0.00885 grams of Bi 2 O 3 . Two samples were then pressed onto a nickel mesh (Exmit, NI 5.5-4/OFA) using a lab press. The nickel mesh served as the counter electrode, with the bismuth-based electrode serving as the working electrode, and Hg/HgO as the reference electrode. A 30% KOH solution was used as the electrolyte. A large volume fraction of graphite was used in the electrode to achieve fast potential sweep rates, however, it is to be understand that much lower graphite contents could also be used.
Referring now to FIG. 6, there is illustrated therein a cyclic voltammagram for the Bi 2 O 3 /C electrode at potential sweep rates of 10 mV per second for first, 60, second, 62, and 50th, 64, cycles for the bismuth electrode. Table 1 below presents data calculated from FIG. 6.
TABLE 1______________________________________UTILIZATION VS. CYCLE NUMBEROF THE BI.sub.2 O.sub.3 ELECTRODE COULOMB/C UTILIZATION (%)______________________________________Theoretical (3e.sup.-) 11.0 --First cycle 12.8 116Second cycle 9.96 90.550th cycle 8.65 78.61000 cycle 8.30 75.5______________________________________
Over 100% utilization was obtained in the first cycle due to the slight amount of hydrogen produced in the first cycle manifested by a shift of curve 60 of FIG. 6 to the negative side. Following the second cycle, the bismuth electrode reached its best performance level. After 1000 cycles (not shown in FIG. 6), the bismuth electrode still maintained a 75% utilization. Bi 2 O 3 may be a preferred starting material for a bismuth anode because it may be considered to be in a fully "discharged" state. It can be conveniently combined with a cathode, e.g. nickel electrode, which also starts in a fully "discharged" state, (Ni(OH) 2 ). Bismuth is a heavy metal (atomic weight 209), however, it gives three electron per Bi atom. A comparison of theoretically and practically specific capacity for several anode materials is presented in Table 2.
Table 2______________________________________Comparison of theoretical and practical specific capacities of Bi,Cd and MH materials: Theoretical (Ah/g) Practical (Ah/g)______________________________________Bi 0.385 0.35*Cd 0.48 0.20MH (0.25˜0.30) 0.275______________________________________ *Based on the present experimental data (90% utilization).
Table 2 shows that the bismuth anode has 1.75 and 1.27 times higher practical specific capacities than cadmium and metal hydride anodes, respectively. The high capacity along with the high rate capability and long cycle life shown above will result in a battery having long cycle life, high energy, and high power densities.
EXAMPLE IV
Another example in which a Bi/Fe/C electrode was prepared is described herein. Electrode fabrication began by mixing 0.1 g of bismuth powder (Aldrich, -100 mesh, 99.99%) with 0.1 g of iron powder (Aldrich, particle size ˜10μ, 99.9%) and 0.8 g of graphite powder (LONZA, KS-6), and appropriate amounts of binder and water/isopropanol solution as described hereinabove with respect to Example I. The charge storage material was dried and cut in small samples also as described hereinabove with respect to Example I.
FIG. 7 illustrates the CV profile for the Bi/Fe/C electrode curve 66 and a Bi/C electrode curve 68 at approximately 5 mV/s, after 2000 cycles for both electrodes. Curve 68 in FIG. 7 is for the Bi/C material as prepared and described in Example I and II. It may be appreciated from FIG. 7 that the Bi/Fe/C electrode has much higher utilization (˜80%) than the Bi/C electrode (52%). No peaks in curve 66 of FIG. 7 can be identified as the contribution of iron; however, the presence of iron appears to cause a higher utilization in the bismuth material. An iron/carbon electrode was tested separately. The results confirmed that iron alone did not contribute any significant current under the present conditions.
While the preferred embodiments of the invention have been illustrated and described, it will be clear that the invention is not so limited. Numerous modifications, changes, variations, substitutions and equivalents will occur to those skilled in the art without departing from the spirit and scope of the present invention as defined by the appended claims.
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An electrochemical, bismuth containing charge storage material and electrochemical cells (10) having an electrode (20) comprising the material. The charge storage material has the composition: Bi x X y M z where Bi is bismuth, M and X are modifiers and x, y, and z represent the relative proportion of each component.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefits of the filing of U.S. Provisional Application No. 61/104,783 filed Oct. 13, 2008. The complete disclosures of the aforementioned related patent applications are hereby incorporated herein by reference for all purposes.
FIELD OF THE INVENTION
[0002] This invention relates to a novel arylindenopyrimidine and its therapeutic and prophylactic uses. Disorders treated and/or prevented include neurodegenerative and movement disorders ameliorated by antagonizing Adenosine A2a receptors.
BACKGROUND OF THE INVENTION
[0003] Adenosine A2a Receptors Adenosine is a purine nucleotide produced by all metabolically active cells within the body. Adenosine exerts its effects via four subtypes of cell surface receptors (A1, A2a, A2b and A3), which belong to the G protein coupled receptor superfamily (Stiles, G. L. Journal of Biological Chemistry, 1992, 267, 6451). A1 and A3 couple to inhibitory G protein, while A2a and A2b couple to stimulatory G protein. A2a receptors are mainly found in the brain, both in neurons and glial cells (highest level in the striatum and nucleus accumbens, moderate to high level in olfactory tubercle, hypothalamus, and hippocampus etc. regions) (Rosin, D. L.; Robeva, A.; Woodard, R. L.; Guyenet, P. G.; Linden, J. Journal of Comparative Neurology,1998, 401, 163).
[0004] In peripheral tissues, A2a receptors are found in platelets, neutrophils, vascular smooth muscle and endothelium (Gessi, S.; Varani, K.; Merighi, S.; Ongini, E.; Bores, P. A. British Journal of Pharmacology, 2000, 129, 2). The striatum is the main brain region for the regulation of motor activity, particularly through its innervation from dopaminergic neurons originating in the substantial nigra. The striatum is the major target of the dopaminergic neuron degeneration in patients with Parkinson's Disease (PD). Within the striatum, A2a receptors are co-localized with dopamine D2 receptors, suggesting an important site for the integration of adenosine and dopamine signaling in the brain (Fink, J. S.; Weaver, D. Ri; Rivkees, S. A.; Peterfreund, R. A.; Pollack, A. E.; Adler, E. M.; Reppert, S. M. Brain Research Molecular Brain Research, 1992,14,186).
[0005] Neurochemical studies have shown that activation of A2a receptors reduces the binding affinity of D2 agonist to their receptors. This D2R and A2aR receptor-receptor interaction has been demonstrated instriatal membrane preparations of rats (Ferre, S.; con Euler, G.; Johansson, B.; Fredholm, B. B.; Fuxe, K. Proceedings of the National Academy of Sciences I of the United States of America, 1991, 88, 7238) as well as in fibroblast cell lines after transfected with A2aR and D2R cDNAs (Salim, H.; Ferre, S.; Dalal, A.; Peterfreund, R. A.; Fuxe, K.; Vincent, J. D.; Lledo, P. M. Journal of Neurochemistry, 2000, 74, 432). In vivo, pharmacological blockade of A2a receptors using A2a antagonist leads to beneficial effects in dopaminergic neurotoxin MPTP(1-methyl-4-pheny-1,2,3,6-tetrahydropyridine)-induced PC) in various species, including mice, rats, and monkeys (Ikeda, K.; Kurokawa, M.; Aoyana, S.; Kuwana, Y. Journal of Neurochemistry, 2002, 80, 262).
[0006] Furthermore, A2a knockout mice with genetic blockade of A2a function have been found to be less sensitive to motor impairment and neurochemical changes when they were exposed to neurotoxin MPTP (Chen, J. F.; Xu, K.; I Petzer, J. P.; Steal, R.; Xu, Y. H.; Beilstein, M.; Sonsalla, P. K.; Castagnoli, K.; Castagnoli, N., Jr.; Schwarsschild, M. A. Journal of Neuroscience, 2001, 1 21, RC1 43).
[0007] In humans, the adenosine receptor antagonist theophylline has been found to produce beneficial effects in PD patients (Mally, J.; Stone, T. W. Journal of the Neurological Sciences, 1995, 132, 129). Consistently, recent epidemiological study has shown that high caffeine consumption makes people less likely to develop PD (Ascherio, A.; Zhang, S. M.; Heman, M. A.; Kawachi, I.; Colditz, G. A.; Speizer, F. E.; Willett, W. C. Annals of Neurology, 2001, 50, 56). In summary, adenosine A2a receptor blockers may provide a new class of antiparkinsonian agents (Impagnatiello, F.; Bastia, E.; Ongini, E.; Monopoli, A. Emerging Therapeutic Targets, 2000, 4, 635).
[0008] Antagonists of the A 2A receptor are potentially useful therapies for the treatment of addiction. Major drugs of abuse (opiates, cocaine, ethanol, and the like) either directly or indirectly modulate dopamine signaling in neurons particularly those found in the nucleus accumbens, which contain high levels of A 2A adenosine receptors. Dependence has been shown to be augmented by the adenosine signaling pathway, and it has been shown that administration of an A 2A receptor antagonist reduces the craving for addictive substances (“The Critical Role of Adenosine A 2A Receptors and Gi βy Subunits in Alcoholism and Addiction: From Cell Biology to Behavior”, by Ivan Diamond and Lina Yao, (The Cell Biology of Addiction, 2006, pp 291-316) and “Adaptations in Adenosine Signaling in Drug Dependence: Therapeutic Implications”, by Stephen P. Hack and Macdonald J. Christie, Critical Review in Neurobiology, Vol. 15, 235-274 (2003)). See also Alcoholism: Clinical and Experimental Research (2007), 31(8), 1302-1307.
[0009] An A 2A receptor antagonist could be used to treat attention deficit hyperactivity disorder (ADHD) since caffeine (a non selective adenosine antagonist) can be useful for treating ADHD, and there are many interactions between dopamine and adenosine neurons. Clinical Genetics (2000), 58(1), 31-40 and references therein.
[0010] Antagonists of the A 2A receptor are potentially useful therapies for the treatment of depression. A 2A antagonists are known to induce activity in various models of depression including the forced swim and tail suspension tests. The positive response is mediated by dopaminergic transmission and is caused by a prolongation of escape-directed behavior rather than by a motor stimulant effect. Neurology (2003), 61(suppl 6) S82-S87.
[0011] Antagonists of the A 2A receptor are potentially useful therapies for the treatment of anxiety. A 2A antagonist have been shown to prevent emotional/anxious responses in vivo. Neurobiology of Disease (2007), 28(2) 197-205.
SUMMARY OF THE INVENTION
[0012] Compounds of Formula A are potent small molecule antagonists of the Adenosine A2a receptor.
[0000]
[0013] wherein:
[0014] R 1 is phenyl wherein said phenyl is optionally substituted with up to three substituents independently selected from the group consisting of F, Cl, Br, and OCH 3 , or a single substituent selected from the group consisting of: OH, OCH 2 CF 3 , OC (1-4) alkyl, C (1-4) alkyl, CHF 2 , OCF 3 , CF 3 , cyclopropyl and CN; or R 1 is heteroaryl optionally substituted with one substituent selected from the group consisting of: —OH, OC (1-4) alkyl, CF 3 , OCF 3 , Cl, Br, —CN, F, CHF 2 , cyclopropyl, and C (1-4) alkyl;
[0015] R 2 is
[0000]
[0000] wherein X is a direct bond or C (1-4) alkyl, and said ring is phenyl or heteroaryl wherein said phenyl or heteroaryl is optionally substituted with —CN, F, Cl, Br, NO 2 , —CF 3 , OC (1-4) alkyl, OCF 3 , or C (1-4) alkyl, alternatively said ring may be heterocyclyl optionally substituted with C (1-4) alkyl;
[0016] wherein R a is C (1-4) alkyl, H, —CH 2 -pyridyl, or pyridyl;
R b is H, or —CH 3 ; and R c is H, or —N(C (1-4) alkyl) 2 ;
[0019] and solvates, hydrates, tautomers, and pharmaceutically acceptable salts thereof.
DETAILED DESCRIPTION OF THE INVENTION
[0020] The invention provides compounds of Formula A
[0000]
[0021] wherein:
[0022] R 1 is phenyl wherein said phenyl is optionally substituted with up to three substituents independently selected from the group consisting of F, Cl, Br, and OCH 3 , or a single substituent selected from the group consisting of: OH, OCH 2 CF 3 , OC (1-4) alkyl, C (1-4) alkyl, CHF 2 , OCF 3 , CF 3 , cyclopropyl and CN; or R 1 is heteroaryl optionally substituted with one substituent selected from the group consisting of: —OH, OC (1-4) alkyl, CF 3 , OCF 3 , Cl, Br, —CN, F, CHF 2 , cyclopropyl, and C (1-4) alkyl;
[0023] R 2 is
[0000]
[0000] wherein X is a direct bond or C (1-4) alkyl, and said ring is phenyl or heteroaryl wherein said phenyl or heteroaryl is optionally substituted with —CN, F, Cl, Br, NO 2 , —CF 3 , OC (1-4) alkyl, OCF 3 , or C (1-4) alkyl, alternatively said ring may be heterocyclyl optionally substituted with C (1-4) alkyl;
[0024] wherein R a is C (1-4) alkyl, H, —CH 2 -pyridyl, or pyridyl;
R b is H, or —CH 3 ; and R c is H, or —N(C (1-4) alkyl) 2 ;
[0027] and solvates, hydrates, tautomers, and pharmaceutically acceptable salts thereof.
[0028] In another embodiment of the invention:
[0029] R 1 is an aromatic ring selected from the group consisting of phenyl, furyl, oxazolyl, isoxazolyl, pyridyl, and thiazolyl, wherein said aromatic ring is optionally substituted with —CN, F, Cl, Br, —CF 3 , OC (1-4) alkyl, OCF 3 , C (1-4) alkyl, or cyclopropyl;
[0030] R 2 is
[0000]
[0000] wherein X is a direct bond or C (1-4) alkyl, and said ring is pyridyl optionally substituted with F, Cl, or Br, alternatively said ring may be heterocyclyl optionally substituted with methyl;
[0031] wherein R a is C (1-4) alkyl, H, —CH 2 -pyridyl, or pyridyl;
R b is H, or —CH 3 ; and R c is H, or —N(C (1-4) alkyl) 2 ;
[0034] and solvates, hydrates, tautomers, and pharmaceutically acceptable salts thereof.
[0035] In another embodiment of the invention:
[0036] R 1 is an aromatic ring selected from the group consisting of phenyl, furyl, oxazolyl, isoxazolyl, pyridyl, and thiazolyl, wherein said aromatic ring is optionally substituted with —CN, F, —CF 3 , OC (1-4) alkyl, OCF 3 , C (1-4) alkyl, or cyclopropyl;
[0000]
[0000] wherein said pyridyl is optionally substituted with Cl;
[0037] wherein R a is C (1-4) alkyl, H, —CH 2 -pyridyl, or pyridyl;
R b is H, or —CH 3 ; and R c is H, or —N(C (1-4) alkyl) 2 ;
[0040] and solvates, hydrates, tautomers, and pharmaceutically acceptable salts thereof.
[0041] In another embodiment of the invention:
[0042] R 1 is an aromatic ring selected from the group consisting of phenyl, furyl, oxazolyl, isoxazolyl, pyridyl, and thiazolyl, wherein said aromatic ring is optionally substituted with —CN, —CF 3 , OC (1-4) alkyl, OCF 3 , C (1-4) alkyl, or cyclopropyl;
[0000]
[0000] wherein said pyridyl is optionally substituted with Cl;
[0043] wherein R a is C (1-4) alkyl, H, —CH 2 -pyridyl, or pyridyl;
R b is H, or —CH 3 ; and R c is H, or —N(C (1-4) alkyl) 2 ;
[0046] and solvates, hydrates, tautomers, and pharmaceutically acceptable salts thereof.
[0047] In another embodiment of the invention:
[0048] R 1 is an aromatic ring selected from the group consisting of phenyl, furyl, oxazolyl, isoxazolyl, and thiazolyl, wherein said aromatic ring is optionally substituted with —CN, —CF 3 , C (1-4) alkyl, or cyclopropyl;
[0000]
[0049] wherein R a is C (1-4) alkyl, H, or pyridyl;
R b is H, or —CH 3 ; and R c is H, or —N(C (1-4) alkyl) 2 ; and solvates, hydrates, tautomers, and pharmaceutically acceptable salts thereof.
[0052] In another embodiment of the invention, the invention is directed to a compound selected from the group consisting of:
[0000]
[0053] and solvates hydrates tautomers and pharmaceutically acceptable salts thereof.
[0054] This invention further provides a method of treating a subject having a condition ameliorated by antagonizing Adenosine A2a receptors, which comprises administering to the subject a therapeutically effective dose of a compound of Formula A.
[0055] This invention further provides a method of preventing a disorder ameliorated by antagonizing Adenosine A2a receptors in a subject, comprising of administering to the subject a prophylactically effective dose of the compound of claim 1 either preceding or subsequent to an event anticipated to cause a disorder ameliorated by antagonizing Adenosine A2a receptors in the subject.
[0056] Compounds of Formula A can be isolated and used as free bases. They can also be isolated and used as pharmaceutically acceptable salts.
[0057] Examples of such salts include hydrobromic, hydroiodic, hydrochloric, perchloric, sulfuric, maleic, fumaric, malic, tartaric, citric, adipic, benzoic, mandelic, methanesulfonic, hydroethanesulfonic, benzenesulfonic, oxalic, palmoic, 2 naphthalenesulfonic, p-toluenesulfonic, cyclohexanesulfamic and saccharie.
[0058] This invention also provides a pharmaceutical composition comprising a compound of Formula A and a pharmaceutically acceptable carrier.
[0059] Pharmaceutically acceptable carriers are well known to those skilled in the art and include, but are not limited to, from about 0.01 to about 0.1 M and preferably 0.05 M phosphate buyer or 0.8% saline. Such pharmaceutically acceptable carriers can be aqueous or non-aqueous solutions, suspensions and emulsions. Examples of non-aqueous solvents are propylene glycol, polyethylene glycol, vegetable oils such as olive oil, and injectable organic esters such as ethyl oleate. Aqueous carriers include water, ethanol, alcoholic/aqueous solutions, glycerol, emulsions or suspensions, including saline and buffered media. Oral carriers can be elixirs, syrups, capsules, tablets and the like. The typical solid carrier is an inert substance such as lactose, starch, glucose, methyl-cellulose, magnesium stearate, dicalcium phosphate, mannitol and the like. Parenteral carriers include sodium chloride solution, Ringer's dextrose, dextrose and sodium chloride, lactated Ringer's and fixed oils. Intravenous carriers include fluid and nutrient replenishers, electrolyte replenishers such as those based on Ringer's dextrose and the like.
[0060] Preservatives and other additives can also be present, such as, for example, antimicrobials, antioxidants, chelating agents, inert gases and the like. All carriers can be mixed as needed with disintegrants, diluents, granulating agents, lubricants, binders and the like using conventional techniques known in the art.
[0061] This invention further provides a method of treating a subject having a condition ameliorated by antagonizing Adenosine A2a receptors, which comprises administering to the subject a therapeutically effective dose of a compound of Formula A.
[0062] In one embodiment, the disorder is a neurodegenerative or movement disorder. Examples of disorders treatable by the instant pharmaceutical composition include, without limitation, Parkinson's Disease, Huntington's Disease, Multiple System Atrophy, Corticobasal Degeneration, Alzheimer's Disease, and Senile Dementia.
[0063] In one preferred embodiment, the disorder is Parkinson's disease.
[0064] As used herein, the term “subject” includes, without limitation, any animal or artificially modified animal having a disorder ameliorated by antagonizing adenosine A2a receptors. In a preferred embodiment, the subject is a human.
[0065] Administering the instant pharmaceutical composition can be effected or performed using any of the various methods known to those skilled in the art. Compounds of Formula A can be administered, for example, intravenously, intramuscularly, orally and subcutaneously. In the preferred embodiment, the instant pharmaceutical composition is administered orally. Additionally, administration can comprise giving the subject a plurality of dosages over a suitable period of time. Such administration regimens can be determined according to routine methods.
[0066] As used herein, a “therapeutically effective dose” of a pharmaceutical composition is an amount sufficient to stop, reverse or reduce the progression of a disorder. A “prophylactically effective dose” of a pharmaceutical composition is an amount sufficient to prevent a disorder, i.e., eliminate, ameliorate and/or delay the disorder's onset. Methods are known in the art for determining therapeutically and prophylactically effective doses for the instant pharmaceutical composition. The effective dose for administering the pharmaceutical composition to a human, for example, can be determined mathematically from the results of animal studies.
[0067] In one embodiment, the therapeutically and/or prophylactically effective dose is a dose sufficient to deliver from about 0.001 mg/kg of body weight to about 200 mg/kg of body weight of a compound of Formula A. In another embodiment, the therapeutically and/or prophylactically effective dose is a dose sufficient to deliver from about 0.05 mg/kg of body weight to about 50 mg/kg of body weight. More specifically, in one embodiment, oral doses range from about 0.05 mg/kg to about 100 mg/kg daily. In another embodiment, oral doses range from about 0.05 mg/kg to about 50 mg/kg daily, and in a further embodiment, from about 0.05 mg/kg to about 20 mg/kg daily. In yet another embodiment, infusion doses range from about 1.0, ug/kg/min to about 10 mg/kg/min of inhibitor, admixed with a pharmaceutical carrier over a period ranging from about several minutes to about several days. In a further embodiment, for topical administration, the instant compound can be combined with a pharmaceutical carrier at a drug/carrier ratio of from about 0.001 to about 0.1.
[0068] The invention also provides a method of treating addiction in a mammal, comprising administering a therapeutically effective dose of a compound of Formula A.
[0069] The invention also provides a method of treating ADHD in a mammal, comprising administering a therapeutically effective dose of a compound of Formula A.
[0070] The invention also provides a method of treating depression in a mammal, comprising administering a therapeutically effective dose of a compound of Formula A.
[0071] The invention also provides a method of treating anxiety in a mammal, comprising administering a therapeutically effective dose of a compound of Formula A.
[0072] Definitions:
[0073] The term “C a-b ” (where a and b are integers referring to a designated number of carbon atoms) refers to an alkyl, alkenyl, alkynyl, alkoxy or cycloalkyl radical or to the alkyl portion of a radical in which alkyl appears as the prefix root containing from a to b carbon atoms inclusive. For example, C 1-4 denotes a radical containing 1, 2, 3 or 4 carbon atoms.
[0074] The term “alkyl,” whether used alone or as part of a substituent group, refers to a saturated branched or straight chain monovalent hydrocarbon radical, wherein the radical is derived by the removal of one hydrogen atom from a single carbon atom. Unless specifically indicated (e.g. by the use of a limiting term such as “terminal carbon atom”), substituent variables may be placed on any carbon chain atom. Typical alkyl radicals include, but are not limited to, methyl, ethyl, propyl, isopropyl and the like. Examples include C 1-8 alkyl, C 1-6 alkyl and C 1-4 alkyl groups.
[0075] The term “heteroaryl” refers to a radical derived by the removal of one hydrogen atom from a ring carbon atom of a heteroaromatic ring system. Typical heteroaryl radicals include furyl, thienyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, isoxazolyl, isothiazolyl, oxadiazolyl, triazolyl, thiadiazolyl, pyridinyl, pyridazinyl, pyrimidinyl, pyrazinyl, indolizinyl, indolyl, isoindolyl, benzo[b]furyl, benzo[b]thienyl, indazolyl, benzimidazolyl, benzthiazolyl, purinyl, 4H-quinolizinyl, quinolinyl, isoquinolinyl, cinnolinyl, phthalzinyl, quinazolinyl, quinoxalinyl, 1,8-naphthyridinyl, pteridinyl and the like.
[0076] Abbreviations:
[0077] Herein and throughout this application, the following abbreviations may be used.
[0078] Cy cyclohexyl
[0079] DMF dimethylformamide
[0080] DMSO dimethylsulfoxide
[0081] Et ethyl
[0082] EtOAc ethyl acetate
[0083] KOtBu potassium tert-butoxide
[0084] Me methyl
[0085] NBS N-bromo succinimide
[0086] OAc acetate
[0087] Pd(dppf)Cl 2 [1,1′-Bis(diphenylphosphino)ferrocene]dichloropalladium(II)
[0088] py pyridine
[0089] THF tetrahydrofuran
[0090] Xantphos 9,9-Dimethyl-4,5-bis(diphenylphosphino)xanthene
EXAMPLES
[0091] Compounds of formula A can be prepared by methods known to those who are skilled in the art. The following reaction schemes are only meant to represent examples of the invention and are in no way meant to be a limit of the invention.
[0000]
[0092] Scheme 1 illustrates the synthetic route leading to compounds of Formula A. Starting with 2-amino-3-cyanothiophene I, condensation under basic conditions with R 1 —CN, where R 1 is as defined in Formula A, affords the aminopyrimidine II. The aminopyrimidine II is then reacted with N-bromosuccinimide (NBS), which gives the bromothiophene III.
[0093] Bromothiophene III can undergo palladium catalyzed amidation with CO and R 2 —H, where R 2 is as defined in Formula A, to afford compounds of Formula A.
[0000]
[0094] Scheme 2 illustrates the synthetic route to compounds of Formula R 1 —CN, where R 1 is a C (1-4) alkyl substituted furan. Scheme 2 also illustrates how any R 1 —CO 2 CH 3 may be converted into R 1 —CN. Bromofuran IV can react with alkylzinc reagents in the presence of a palladium catalyst to give V. Ester V (or any R 1 —CO 2 CH 3 ) is reacted with ammonium hydroxide to give the corresponding amide VI. Dehydration of the amide is accomplished using POCl 3 in pyridine to give the desired heterocyclic nitrile R 1 —CN.
EXAMPLES
[0095] The following examples are for exemplary purposes only, and are in no way meant to limit the invention.
Example 1
3-[4-Amino-6-(2,6-dimethyl-morpholine-4-carbonyl)-thieno[2,3-d]pyrimidin-2-yl]-benzonitrile
Example 1
Step a
3-(4-Amino-thieno[2,3-d]pyrimidin-2-yl)-benzonitrile
[0096]
[0097] Solid potassium-tert-butoxide (1.1 g, 10.1 mmol) was added to a dioxane solution (20 mL) of 2-Amino-thiophene-3-carbonitrile (5.0 g, 40.3 mmol) and 1,3-dicyanobenzene (7.2 g, 56.5 mmol). The resulting slurry was stirred vigorously at 130° C. for 15 minutes. The dark slurry was cooled to room temperature, diluted with THF, and dry packed onto silica gel. The material was the purified via column chromatography to give 10.2 g of the title compound.
Example 1
Step b
3-(4-Amino-6-bromo-thieno[2,3-d]pyrimidin-2-yl)-benzonitrile
[0098]
[0099] Solid NBS (1.6 g, 8.7 mmol) was added to a DMF solution (20 mL) of 3-(4-Amino-thieno[2,3-d]pyrimidin-2-yl)-benzonitrile (2.0 g, 7.9 mmol). After 45 minutes water was added and the resulting precipitate was collected by filtration, washed with water, and dried in vacuo to give 2.4 g of the title compound.
Example 1
Step c
3-[4-Amino-6-(2,6-dimethyl-morpholine-4-carbonyl)-thieno[2,3-d]pyrimidin-2-yl]-benzonitrile (1)
[0100]
[0101] Neat cis-2,6-dimethylmorpholine (70 μL, 0.56 mmol) was added to a toluene (2 mL)/DMF (0.4 mL) solution of 3-(4-Amino-6-bromo-thieno[2,3-d]pyrimidin-2-yl)-benzonitrile (124 mg, 0.37 mmol), Xantphos (21 mg, 0.04 mmol), Pd(OAc) 2 (8 mg, 0.04 mmol), and Na 2 CO 3 (118 mg, 1.11 mmol) and the reaction flask was evacuated and purged 3 times with CO (balloon). The mixture was then heated to 100° C. After 5 h the mixture was filtered hot and washed with EtOAc. The organic layer was then washed with brine, water and brine, dried (Na 2 SO 4 ), dry packed onto silica gel and purified via column chromatography to give 66 mg of the title compound as the free base, which was dissolved in THF and added to 1 mL of 1 N HCl in ether, concentrated, and dried in vacuo to give the title compound 3-[4-Amino-6-(2,6-dimethyl-morpholine-4-carbonyl)-thieno[2,3-d]pyrimidin-2-yl]-benzonitrile (1) as the HCl salt (1). 1 H NMR (Acetone, 300 MHz): δ=8.73-8.80 (m, 2 H), 7.86-7.93 (m, 2 H), 7.68-7.78 (m, 1 H), 7.26 (br. s., 2 H), 4.37 (d, J=12.8 Hz, 2 H), 3.66 (ddd, J=10.6, 6.3, 2.6 Hz, 2 H), 3.41 (q, J=6.8 Hz, 2 H), 2.84 (s, 3 H), 2.81 ppm (s, 3 H); MS m/e 394 (M+H).
Example 2
3-[4-Amino-6-(morpholine-4-carbonyl)-thieno[2,3-d]pyrimidin-2-yl]-benzonitrile
[0102]
[0103] The title compound was prepared using morpholine in place of cis-2,6-dimethylmorpholine as described in Example 1. 1 H NMR (CHLOROFORM-d, 300 MHz): δ=8.77 (s, 1 H), 8.69 (d, J=7.9 Hz, 1 H), 7.73 (d, J=7.5 Hz, 1 H), 7.46-7.63 (m, 1 H), 5.63 (br. s., 2 H), 3.79 ppm (d, J=3.8 Hz, 8 H); MS m/e 344 (M+H); MS m/e 366 (M+H).
Example 3
[4-Amino-2-(4-methyl-thiazol-2-yl)-thieno[2,3-d]pyrimidin-6-yl]-morpholin-4-yl-methanone
[0104]
[0105] The title compound was prepared using 4-methyl-thiazole-2-carbonitrile and morpholine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. 1 H NMR (DMSO-d 6 , 300 MHz): δ=8.00 (br. s., 2 H), 7.97 (s, 1 H), 7.47 (s, 1 H), 7.47 (s, 1 H), 3.70 (d, J=5.3 Hz, 8 H), 2.45 ppm (s, 3 H); MS m/e 362 (M+H).
Example 4
(4-Amino-2-thiazol-2-yl-thieno[2,3-d]pyrimidin-6-yl)-morpholin-4-yl-methanone
[0106]
[0107] The title compound was prepared using thiazole-2-carbonitrile and morpholine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. The thiazole-2-carbonitrile was prepared using thiazole-2-carboxylic acid ethyl ester in place of 5-cyclopropyl-furan-2-carboxylic acid methyl ester, as described in Example 14. 1 H NMR (Acetone, 300 MHz): δ=8.00 (d, J=3.0 Hz, 1 H), 7.95 (s, 1 H), 7.77 (d, J=3.4 Hz, 1 H), 7.34 (br. s., 2 H), 3.67-3.88 ppm (m, 8 H); MS m/e 348 (M+H).
Example 5
[4-Amino-2-(5-methyl-furan-2-yl)-thieno[2,3-d]pyrimidin-6-yl]-morpholin-4-yl-methanone
[0108]
[0109] The title compound was prepared using 5-methyl-2-furonitrile and morpholine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. 1 H NMR (DMSO-d 6 , 300 MHz): δ=7.91 (s, 1 H), 7.79 (br. s., 2 H), 7.09 (d, J=3.0 Hz, 1 H), 6.29 (d, J=3.4 Hz, 1 H), 3.69 (d, J=4.9 Hz, 8 H), 2.37 ppm (s, 3 H); MS m/e 345 (M+H).
Example 6
(4-Amino-2-oxazol-2-yl-thieno[2,3-d]pyrimidin-6-yl)-morpholin-4-yl-methanone
[0110]
[0111] The title compound was prepared using oxazole-2-carbonitrile and morpholine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. The oxazole-2-carbonitrile was prepared using oxazole-2-carboxylic acid ethyl ester in place of 5-cyclopropyl-furan-2-carboxylic acid methyl ester, as described in Example 14. 1 H NMR (Acetone, 300 MHz): δ=8.13 (s, 1 H), 7.95 (s, 1 H), 7.41 (s, 1 H), 7.34 (br. s., 2 H), 3.64-3.90 ppm (m, 8 H); MS m/e 332 (M+H).
Example 7
4-Amino-2-(4-methyl-thiazol-2-yl)-thieno[2,3-d]pyrimidine-6-carboxylic acid[2-(1,1-dioxo-1-thiomorpholin-4-yl)-ethyl]-amide
[0112]
[0113] The title compound was prepared using 4-methyl-thiazole-2-carbonitrile and 2-(1,1-dioxo-1-thiomorpholin-4-yl)-ethylamine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. 1 H NMR (Acetone, 300 MHz): δ=9.01 (br. s., 1 H), 8.67 (s, 1 H), 7.50 (s, 1 H), 4.06 (br. s., 4 H), 3.94 (d, J=5.3 Hz, 2 H), 3.73 (t, J=5.5 Hz, 2 H), 3.67 (br. s., 4 H), 2.48 (s, 3 H), 1.24 (s, 2H); MS m/e 453 (M+H)
Example 8
[4-Amino-2-(4-methyl-thiazol-2-yl)-thieno[2,3-d]pyrimidin-6-yl]-(4-pyridin-4-yl-piperazin-1-yl)-methanone
[0114]
[0115] The title compound was prepared using 4-methyl-thiazole-2-carbonitrile and 1-pyridin-4-yl-piperazine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. 1 H NMR (DMSO-d 6 , 300 MHz): δ=8.26-8.37 (m, J=7.5 Hz, 2 H), 8.07 (s, 1 H), 8.06 (br. s., 2 H), 7.48 (s, 1 H), 7.12-7.25 (m, J=7.5 Hz, 2 H), 3.72-4.04 ppm (m, 8 H), 2.48 (s, 3 H); MS m/e 438 (M+H)
Example 9
3-[4-Amino-6-(4-tert-butyl-piperazine-1-carbonyl)-thieno[2,3-d]pyrimidin-2-yl]-benzonitrile
[0116]
[0117] The title compound was prepared using 1-tert-butyl-piperazine in place of cis-2,6-dimethylmorpholine as described in Example 1. 1 H NMR (Acetone, 300 MHz): δ=8.59-8.66 (m, 2 H), 7.68-7.85 (m, 2 H), 7.45-7.65 (m, 1 H), 7.14 (br. s., 2 H), 3.67 (br. s., 4 H), 2.58 (br. s., 4 H), 0.98 ppm (s, 9 H); MS m/e 421 (M+H).
Example 10
4-Amino-2-(3-cyano-phenyl)-thieno[2,3-d]pyrimidine-6-carboxylic acid(2-morpholin-4-yl-ethyl)-amide
[0118]
[0119] The title compound was prepared using 2-morpholin-4-yl-ethylamine in place of cis-2,6-dimethylmorpholine as described in Example 1. 1 H NMR (DMSO-d 6 , 300 MHz): δ=8.62-8.72 (m, 2 H), 8.56 (t, J=5.7 Hz, 1 H), 8.10 (s, 1 H), 7.97 (d, J=7.9 Hz, 1 H), 7.91 (br. s., 2 H), 7.73 (t, J=7.7 Hz, 1 H), 3.55-3.65 (m, 4 H), 3.40 (q, J=6.8 Hz, 2 H), 2.39-2.48 ppm (m, 6 H); MS m/e 409 (M+H).
Example 11
4-Amino-2-(4-methyl-thiazol-2-yl)-thieno[2,3-d]pyrimidine-6-carboxylic acid(2-pyridin-3-yl-ethyl)-amide
[0120]
[0121] The title compound was prepared using 4-methyl-thiazole-2-carbonitrile and 2-pyridin-3-yl-ethylamine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. 1 H NMR (DMSO-d 6 , 300 MHz): δ=8.79 (s, 1 H), 8.48 (d, J=1.9 Hz, 1 H), 8.43 (dd, J=4.9, 1.5 Hz, 1 H), 8.07 (s, 1 H), 7.98 (br. s., 2 H), 7.69 (d, J=7.9 Hz, 1 H), 7.46 (s, 1 H), 7.33 (dd, J=7.7, 4.7 Hz, 1 H), 3.53 (d, J=5.7 Hz, 2 H), 2.89 (t, J=7.0 Hz, 2 H), 2.45 ppm (s, 3 H); MS m/e 397 (M+H).
Example 12
4-Amino-2-(4-methyl-thiazol-2-yl)-thieno[2,3-d]pyrimidine-6-carboxylic acid(tetrahydro-pyran-4-yl)-amide
[0122]
[0123] The title compound was prepared using 4-methyl-thiazole-2-carbonitrile and tetrahydro-pyran-4-ylamine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. 1 H NMR (Acetone, 300 MHz): δ=8.10 (s, 1 H), 7.78 (br. s., 1 H), 7.32 (s, 1 H), 7.18-7.25 (br. s., 2H), 3.93 (d, J=9.4 Hz, 1 H), 3.81 (d, J=7.5 Hz, 1 H), 3.48 (td, J=11.8, 2.1 Hz, 2 H), 3.38 (td, J=11.5, 2.3 Hz, 1 H), 2.49 (s, 3 H), 1.88-1.97 (m, 1 H), 1.80 (m, 1 H), 1.55-1.73 (m, 1 H), 1.35 ppm (dd, J=13.0, 4.3 Hz, 1 H); MS m/e 376 (M+H).
Example 13
4-Amino-2-oxazol-2-yl-thieno[2,3-d]pyrimidine-6-carboxylic acid(tetrahydro-pyran-4-yl)-amide
[0124]
[0125] The title compound was prepared using oxazole-2-carbonitrile and tetrahydro-pyran-4-ylamine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. The oxazole-2-carbonitrile was prepared using oxazole-2-carboxylic acid ethyl ester in place of 5-cyclopropyl-furan-2-carboxylic acid methyl ester, as described in Example 14. 1 H NMR (Acetone, 300 MHz): δ=8.37 (s, 1 H), 8.13 (s, 1 H), 7.94 (br. s., 1 H), 7.41 (s, 1 H), 7.33-7.40 (br. s., 2 H), 4.04-4.26 (m, 1 H), 3.81-4.03 (m, 2 H), 3.47 (td, J=11.8, 2.1 Hz, 2 H), 1.92 (dd, J=12.4, 2.3 Hz, 2 H), 1.59-1.78 ppm (m, 2 H); MS m/e 346 (M+H).
Example 14
4-Amino-2-(5-cyclopropyl-furan-2-yl)-thieno[2,3-d]pyrimidine-6-carboxylic acid(pyridin-3-ylmethyl)-amide
Example 14
Step a
5-Cyclopropyl-furan-2-carboxylic acid methyl ester
[0126]
[0127] Solid cyclopropylboronic acid (575 mg, 6.7 mmol) was added to a toluene (22 mL)/water (1.1 mL) solution of 5-bromo-furan-2-carboxylic acid methyl ester (980 mg, 4.8 mmol), Pd(OAc) 2 (54 mg, 0.2 mmol), P(Cy) 3 (135 mg, 0.5 mmol), and K 3 PO 4 (3.6 g, 16.8 mmol). The resulting mixture was heated to 90° C. After 5 h the mixture was cooled, filtered and extracted with EtOAc. The combined organic extracts were washed with water and brine, dried (Na 2 SO 4 ), concentrated and purified via column chromatography to give 650 mg of 5-cyclopropyl-furan-2-carboxylic acid methyl ester.
Example 14
Step b
5-Cyclopropyl-furan-2-carboxylic acid amide
[0128]
[0129] 5-cyclopropyl-furan-2-carboxylic acid methyl ester (650 mg, 3.9 mmol) was suspended in concentrated NH 4 OH (20 mL) and stirred vigorously. After 16 h the mixture was diluted with water and the aqueous phase was extracted with EtOAc. The combined organic extracts were washed with water and brine, dried (Na 2 SO 4 ), concentrated and used without further purification to give 550 mg of 5-cyclopropyl-furan-2-carboxylic acid amide.
Example 14
Step c
5-Cyclopropyl-furan-2-carbonitrile
[0130]
[0131] Neat POCl 3 (0.48 mL, 5.1 mmol) was added to a pyridine solution (9 mL) of 5-cyclopropyl-furan-2-carboxylic acid amide (550 mg, 3.6 mmol). After 2 h the mixture was cooled to 0° C. and taken to pH 4.5 with concentrated aqueous HCl. The aqueous mixture was extracted with Et 2 O and the combined extracts were washed with brine, dried (Na 2 SO 4 ), concentrated and used without further purification to give 478 mg of 5-cyclopropyl-furan-2-carbonitrile.
Example 14
Step d
4-Amino-2-(5-cyclopropyl-furan-2-yl)-thieno[2,3-d]pyrimidine-6-carboxylic acid(pyridin-3-ylmethyl)-amide (14)
[0132]
[0133] The title compound was prepared using 5-cyclopropyl-furan-2-carbonitrile and pyridin-3-yl-methylamine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. 1 H NMR (DMSO-d 6 , 300 MHz): δ=9.30 (s, 1 H), 8.80 (s, 1 H), 8.72 (d, J=4.5 Hz, 1 H), 8.25 (d, J=7.9 Hz, 1 H), 8.14 (s, 1 H), 7.73-7.90 (m, 3 H), 7.10 (d, J=3.4 Hz, 1 H), 6.26 (d, J=3.4 Hz, 1 H), 4.60 (d, J=5.7 Hz, 2 H), 2.02 (d, J=15.1 Hz, 1 H), 0.91-1.03 (m, 2 H), 0.70-0.85 ppm (m, 2 H); MS m/e 392 (M+H)
Example 15
4-Amino-2-(3-cyano-phenyl)-thieno[2,3-d]pyrimidine-6-carboxylic acid(pyridin-2-ylmethyl)-amide
[0134]
[0135] The title compound was prepared using pyridin-2-yl-methylamine in place of cis-2,6-dimethylmorpholine as described in Example 1. 1 H NMR (Acetone, 300 MHz): δ=8.69-8.83 (m, 3 H), 8.54 (d, J=3.8 Hz, 1 H), 8.21 (s, 1 H), 7.88 (d, J=7.5 Hz, 1 H), 7.61-7.81 (m, 2 H), 7.43 (d, J=7.9 Hz, 1 H), 7.13-7.33 (m, 3 H), 4.70 ppm (d, J=5.7 Hz, 2 H); MS m/e 387 (M+H).
Example 16
4-Amino-2-(3-cyano-phenyl)-thieno[2,3-d]pyrimidine-6-carboxylic acid(2-pyridin-3-yl-ethyl)-amide
[0136]
[0137] The title compound was prepared using 2-pyridin-3-yl-ethylamine in place of cis-2,6-dimethylmorpholine as described in Example 1. 1 H NMR (Acetone, 300 MHz): δ=9.80 (br. s., 1 H), 9.66 (d, J=4.9 Hz, 1 H), 9.44-9.55 (m, 2 H), 9.40 (d, J=7.9 Hz, 1 H), 9.13 (br. s., 1 H), 9.04 (s, 1 H), 8.79-8.94 (m, 1 H), 8.64 (d, J=7.5 Hz, 1 H), 8.47 (t, J=8.3 Hz, 1 H), 4.50-4.67 (m, 2 H), 3.96-4.14 (m, 2 H), 2.67-2.90(m, 2 H); MS m/e 401 (M+H)
Example 17
[4-Amino-2-(5-methyl-isoxazol-3-yl)-thieno[2,3-d]pyrimidin-6-yl]-morpholin-4-yl-methanone
[0138]
[0139] The title compound was prepared using 5-methyl-isoxazole-3-carbonitrile and morpholine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. 1 H NMR (DMSO-d 6 , 300 MHz): δ=7.97 (s, 3 H), 6.71 (s, 1 H), 3.70 (m, 8 H), 2.48 ppm (s, 3 H); MS m/e 346 (M+H).
Example 18
[4-Amino-2-(4-methyl-thiazol-2-yl)-thieno[2,3-d]pyrimidin-6-yl]-(4-ethyl-piperazin-1-yl)-methanone hydrochloride
[0140]
[0141] The title compound was prepared using 4-methyl-thiazole-2-carbonitrile and 1-ethyl-piperazine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. 1 H NMR (DMSO-d 6 , 300 MHz): δ=8.12 (s, 1 H), 7.50 (s, 1 H), 4.47 (br. m., 4 H), 3.53 (m., 4 H), 3.16 (m, 2 H), 2.45 (s, 3 H), 1.18-1.33 (m, 3 H); MS m/e 389 (M+H)
Example 19
4-Amino-2-(3-cyano-phenyl)-thieno[2,3-d]pyrimidine-6-carboxylic acid(pyridin-3-ylmethyl)-amide
[0142]
[0143] The title compound was prepared using pyridin-3-yl-methylamine in place of cis-2,6-dimethylmorpholine as described in Example 1. 1 H NMR (DMSO-d 6 , 300 MHz): δ=8.60-8.68 (m, 2 H), 8.47 (d, J=4.9 Hz, 1 H), 7.93 (d, J=7.9 Hz, 1 H), 7.65-7.82 (m, 3 H), 7.60 (br. s., 2 H), 7.45-7.54 (m, 1 H), 7.40 (s, 1 H), 6.64 (d, J=5.3 Hz, 1 H), 6.24 ppm (d, J=5.3 Hz, 2 H); MS m/e 387 (M+H)
Example 20
4-Amino-2-(4-methyl-thiazol-2-yl)-thieno[2,3-d]pyrimidine-6-carboxylic acid(6-chloro-pyridin-3-yl-methyl)-amide hydrochloride
[0144]
[0145] The title compound was prepared using 4-methyl-thiazole-2-carbonitrile and (6-Chloro-pyridin-3-yl)-methylamine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. 1 H NMR (Acetone, 300 MHz): δ=7.22 (d, J=2.6 Hz, 1 H), 6.99 (s, 1 H), 6.66 (dd, J=8.1, 2.4 Hz, 1 H), 6.21 (d, J=8.3 Hz, 1 H), 6.11 (s, 1 H), 3.35-3.51 (m, 2 H), 1.26 ppm (s, 3 H); MS m/e 417 (M+H)
Example 21
4-Amino-2-(5-methyl-isoxazol-3-yl)-thieno[2,3-d]pyrimidine-6-carboxylic acid(pyridin-3-ylmethyl)-amide
[0146]
[0147] The title compound was prepared using 5-methyl-isoxazole-3-carbonitrile and pyridin-3-yl-methylamine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. 1 H NMR (MeOD, 300 MHz): δ=8.85 (s, 1 H), 8.73 (d, J=5.3 Hz, 1 H), 8.51 (d, J=8.3 Hz, 1 H), 8.06 (s, 1 H), 7.97 (dd, J=8.3, 5.7 Hz, 1 H), 6.73 (s, 1 H), 4.76 (s, 2 H), 2.52 (s, 3 H); MS m/e 367 (M+H)
Example 22
4-Amino-2-(5-methyl-isoxazol-3-yl)-thieno[2,3-d]pyrimidine-6-carboxylic acid(2-pyridin-3-yl-ethyl)-amide
[0148]
[0149] The title compound was prepared using 5-methyl-isoxazole-3-carbonitrile and 2-pyridin-3-yl-ethylamine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. 1 H NMR (DMSO-d 6 , 300 MHz): δ=8.78-8.90 (m, 1 H), 8.73 (s, 1 H), 8.67 (d, J=4.5 Hz, 1 H), 8.20 (d, J=7.9 Hz, 1 H), 8.11 (s, 1 H), 7.99 (br. s., 2 H), 7.76 (dd, J=7.7, 5.5 Hz, 1 H), 6.71 (s, 1 H), 3.59 (q, J=6.5 Hz, 2 H), 3.01(t, J=6.8 Hz, 2 H), 2.48 (s, 3H); MS m/e 381 (M+H)
Example 23
[4-Amino-2-(4-methyl-thiazol-2-yl)-thieno[2,3-d]pyrimidin-6-yl]-(4-tert-butyl-piperazin-1-yl)-methanone
[0150]
[0151] The title compound was prepared using 4-methyl-thiazole-2-carbonitrile and 1-tert-butyl-piperazine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. 1 H NMR (DMSO-d 6 , 300 MHz): δ=11.15 (br. s., 2 H), 7.40 (s, 1 H), 7.06 (s, 1 H), 4.49 (d, J=13.6 Hz, 4 H), 3.56 (d, J=12.1 Hz, 4 H), 2.45 (s., 3 H), 1.23 ppm (s, 9 H);MS m/e 417 (M+H)
Example 24
4-Amino-2-oxazol-2-yl-thieno[2,3-d]pyrimidine-6-carboxylic acid(pyridin-2-ylmethyl)-amide
[0152]
[0153] The title compound was prepared using oxazole-2-carbonitrile and pyridin-2-yl-methylamine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. The oxazole-2-carbonitrile was prepared using oxazole-2-carboxylic acid ethyl ester in place of 5-cyclopropyl-furan-2-carboxylic acid methyl ester, as described in Example 14. 1 H NMR (DMSO-d 6 , 400 MHz): δ=9.28 (t, J=5.6 Hz, 1 H), 8.54 (d, J=4.9 Hz, 1 H), 8.30 (s, 1 H), 8.22 (s, 1 H), 8.04 (br. s., 2 H), 7.74-7.83 (m, 1 H), 7.47 (s, 1 H), 7.37 (d, J=7.8 Hz, 1 H), 7.24-7.33 (m, 1 H), 4.58 ppm (d, J=5.9 Hz, 2 H); MS m/e 353 (M+H).
Example 25
4-Amino-2-oxazol-2-yl-thieno[2,3-d]pyrimidine-6-carboxylic acid(2-morpholin-4-yl-ethyl)-amide
[0154]
[0155] The title compound was prepared using oxazole-2-carbonitrile and 2-morpholin-4-yl-ethylamine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. The oxazole-2-carbonitrile was prepared using oxazole-2-carboxylic acid ethyl ester in place of 5-cyclopropyl-furan-2-carboxylic acid methyl ester, as described in Example 14. 1 H NMR (Acetone, 300 MHz): δ=8.05 (s, 1 H), 7.99 (s, 1 H), 7.76 (br. s., 1 H), 7.27 (s, 3 H), 3.47-3.56 (m, 4 H), 3.42 (q, J=6.4 Hz, 2 H), 2.48 (t, J=6.6 Hz, 2 H), 2.31-2.43 (m, 4 H); MS m/e 375 (M+H).
Example 26
[4-Amino-2-(4-trifluoromethyl-thiazol-2-yl)-thieno[2,3-d]pyrimidin-6-yl]-morpholin-4-yl-methanone
[0156]
[0157] The title compound was prepared using 4-trifluoromethyl-thiazole-2-carbonitrile and morpholine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. The 4-trifluoromethyl-thiazole-2-carbonitrile was prepared using 5-trifluoromethyl-thiazole-2-carboxylic acid ethyl ester in place of 5-cyclopropyl-furan-2-carboxylic acid methyl ester, as described in Example 14. 1 H NMR (Acetone, 300 MHz): δ=8.41 (s, 1 H), 7.96 (s, 1 H), 7.41 (br. s., 2 H), 3.65-3.89 ppm (m, 8 H); MS m/e 416 (M+H).
Example 27
4-Amino-2-(4-methyl-thiazol-2-yl)-thieno[2,3-d]pyrimidine-6-carboxylic acid(pyridin-3-ylmethyl)-amide
[0158]
[0159] The title compound was prepared using 4-methyl-thiazole-2-carbonitrile and pyridin-3-yl-methylamine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. 1 H NMR (DMSO-d 6 , 300 MHz): δ=9.29 (s, 1 H), 8.58 (d, J=1.9 Hz, 1 H), 8.48 (dd, J=4.5, 1.5 Hz, 1 H), 8.15 (s, 1 H), 7.98 (br. s., 2 H), 7.75 (d, J=8.3 Hz, 1 H), 7.47 (s, 1 H), 7.38 (dd, J=7.2, 4.9 Hz, 1 H), 4.50 (d, J=6.0 Hz, 2 H), 2.45 (s, 3 H); MS m/e 383 (M+H)
Example 28
[4-Amino-2-(4-methyl-thiazol-2-yl)-thieno[2,3-d]pyrimidin-6-yl]-(4-pyridin-2-ylmethyl-piperazin-1-yl)-methanone
[0160]
[0161] The title compound was prepared using 4-methyl-thiazole-2-carbonitrile and 1-pyridin-2-ylmethyl-piperazine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. 1 H NMR (DMSO-d 6 , 300 MHz): δ=8.72 (d, J=3.8 Hz, 1 H), 8.02 (s, 2 H), 7.97 (td, J=7.7, 1.5 Hz, 2 H), 7.43-7.60 (m, 3 H), 4.57 (s, 2 H), 4.02 (br. s., 4 H), 3.40 (br. s., 4 H), 2.48 (s, 3 H); MS m/e 452 (M+H)
Example 29
[4-Amino-2-(5-cyclopropyl-furan-2-yl)-thieno[2,3-d]pyrimidin-6-yl]-morpholin-4-yl-methanone
[0162]
[0163] The title compound was prepared using 5-cyclopropyl-furan-2-carbonitrile and morpholine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. The 5-cyclopropyl-furan-2-carbonitrile was prepared as described in Example 14. 1 H NMR (CHLOROFORM-d, 300 MHz): δ=7.43 (s, 1 H), 7.21 (d, J=3.4 Hz, 1 H), 6.06 (d, J=3.4 Hz, 1 H), 5.57 (br. s., 2 H), 3.66-3.85 (m, 8 H), 2.00-2.12 (m, 1 H), 0.80-1.06 ppm (m, 4 H); MS m/e 371 (M+H).
Example 30
[4-Amino-2-(5-isopropyl-furan-2-yl)-thieno[2,3-d]pyrimidin-6-yl]-morpholin-4-yl-methanone
Example 30
Step a
5-Isopropyl-furan-2-carboxylic acid methyl ester
[0164]
[0165] A 0.5 M THF solution (7.3 mL, 3.6 mmol) of isopropylzinc bromide was added to a THF solution (2 mL) of 5-bromo-furan-2-carboxylic acid methyl ester (250 mg, 1.2 mmol) and Pd(dppf)Cl 2 (98 mg, 0.1 mmol) and the resulting mixture was heated to 70° C. After 15 h the mixture was cooled, water was added and the aqueous phase was extracted with EtOAc. The combined organic extracts were washed with water and brine, dried (Na 2 SO 4 ), concentrated and purified via column chromatography to give 150 mg of 5-isoopropyl-furan-2-carboxylic acid methyl ester. Steps b and c of Example 14 were followed to access the desired carbonitrile.
Example 30
Step b
[4-Amino-2-(5-isopropyl-furan-2-yl)-thieno[2,3-d]pyrimidin-6-yl]-morpholin-4-yl-methanone (30)
[0166]
[0167] The title compound was prepared using 5-isopropyl-furan-2-carbonitrile and morpholine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. The 5-isopropyl-furan-2-carbonitrile was prepared using 5-isopropyl-furan-2-carboxylic acid methyl ester in place of 5-cyclopropyl-furan-2-carboxylic acid methyl ester, as described in Example 14. 1 H NMR (CHLOROFORM-d, 300 MHz): δ=7.47 (s, 1 H), 7.23 (d, J=3.4 Hz, 1 H), 6.08-6.25 (m, 1 H), 5.69 (s, 2 H), 3.68-3.82 (m, 8 H), 3.12 (dt, J=13.7, 6.9 Hz, 1 H), 1.32 ppm (d, J=7.2 Hz, 6 H); MS m/e 373 (M+H).
Example 31
[4-Amino-2-(5-isopropyl-furan-2-yl)-thieno[2,3-d]pyrimidin-6-yl]-(4-tert-butyl-piperazin-1-yl)-methanone
[0168]
[0169] The title compound was prepared using 5-isopropyl-furan-2-carbonitrile and 1-tert-butyl-piperazine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. The 5-isopropyl-furan-2-carbonitrile was prepared using 5-isopropyl-furan-2-carboxylic acid methyl ester in place of 5-cyclopropyl-furan-2-carboxylic acid methyl ester, as described in Example 30. 1 H NMR (CHLOROFORM-d, 400 MHz): δ=7.41 (s, 1 H), 7.23 (d, J=3.2 Hz, 1 H), 6.09-6.24 (m, 1 H), 5.48 (br. s., 2 H), 3.80 (br. s., 4 H), 3.08-3.18 (m, 1 H), 2.66 (br. s., 4 H), 1.33 (d, J=6.8 Hz, 6 H), 1.10 ppm (s, 9 H); MS m/e 428 (M+H).
Example 32
[4-Amino-2-(5-cyclopropyl-furan-2-yl)-thieno[2,3-d]pyrimidin-6-yl]-(4-tert-butyl-piperazin-1-yl)-methanone
[0170]
[0171] The title compound was prepared using 5-cyclopropyl-furan-2-carbonitrile and 1-tert-butyl-piperazine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. The 5-cyclopropyl-furan-2-carbonitrile was prepared as described in Example 14. 1 H NMR (CHLOROFORM-d, 300 MHz): δ=7.41 (s, 1 H), 7.21 (d, J=3.4 Hz, 1 H), 6.06 (d, J=3.4 Hz, 1 H), 5.54 (s, 2 H), 3.71-3.84 (m, 4 H), 2.55-2.69 (m, 4 H), 1.98-2.13 (m, 1 H), 1.09 (s, 9 H), 0.92-1.02 (m, 2 H), 0.79-0.90 ppm (m, 2 H); MS m/e 426 (M+H).
Example 33
[4-Amino-2-(4-methyl-thiazol-2-yl)-thieno[2,3-d]pyrimidin-6-yl]-(4-thiazol-2-yl-piperazin-1-yl)-methanone
[0172]
[0173] The title compound was prepared using 4-methyl-thiazole-2-carbonitrile and 1-thiazol-2-yl-piperazine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. 1 H NMR (DMSO-d 6 , 300 MHz): δ=8.06 (s, 2H), 8.01 (s, 1 H), 7.48 (s, 1 H), 7.19-7.29 (m, 1 H), 6.88-6.98 (m, 1 H), 3.88 (br. s, 4H), 3.58 (br. s., 4 H), 2.48 (s, 3 H); MS m/e 444 (M+H)
Example 34
[4-Amino-2-(5-ethyl-furan-2-yl)-thieno[2,3-d]pyrimidin-6-yl]-morpholin-4-yl-methanone
[0174]
[0175] The title compound was prepared using 5-ethyl-furan-2-carbonitrile and morpholine in place of 1,3-dicyanobenzene and cis-2,6-dimethylmorpholine, respectively, as described in Example 1. The 5-isopropyl-furan-2-carbonitrile was prepared using 5-ethyl-furan-2-carboxylic acid methyl ester in place of 5-cyclopropyl-furan-2-carboxylic acid methyl ester, as described in Example 30. 1 H NMR (Acetone, 300 MHz): δ=7.73 (s, 1 H), 7.00 (d, J=3.4 Hz, 1 H), 6.91 br. s., 2 H), 6.11 (d, J=3.4 Hz, 1 H), 3.55-3.71 (m, 8 H), 2.55-2.66 (m, 2 H), 1.15 ppm (t, J=7.5 Hz, 3 H); MS m/e 359 (M+H).
Biological Assays and Activity
Ligand Binding Assay for Adenosine A2a Receptor (A2A-B)
[0176] Ligand binding assay of adenosine A2a receptor was performed using plasma membrane of HEK293 cells containing human A2a adenosine receptor (PerkinElmer, RB-HA2a) and radioligand [ 3 H]CGS21680 (PerkinElmer, NET1021). Assay was set up in 96-well polypropylene plate in total volume of 200 μL by sequentially adding 20 μL 1:20 diluted membrane, 130 μL assay buffer (50 mM Tris·HCl, pH7.4 10 mM MgCl 2 , 1 mM EDTA) containing [ 3 H] CGS21680, 50 μL diluted compound (4×) or vehicle control in assay buffer. Nonspecific binding was determined by 80 mM NECA. Reaction was carried out at room temperature for 2 hours before filtering through 96-well GF/C filter plate pre-soaked in 50 mM Tris·HCl, pH7.4 containing 0.3% polyethylenimine. Plates were then washed 5 times with cold 50 mM Tris·HCl, pH7.4, dried and sealed at the bottom. Microscintillation fluid 30 μL was added to each well and the top sealed. Plates were counted on Packard Topcount for [ 3 H]. Data was analyzed in Microsoft Excel and GraphPad Prism programs. (Varani, K.; Gessi, S.; Dalpiaz, A.; Borea, P. A. British Journal of Pharmacology, 1996, 117, 1693)
Adenosine A2a Receptor Functional Assay (A2AGAL2)
[0177] To initiate the functional assay, cryopreserved CHO-K1 cells overexpressing the human adenosine A2a receptor and containing a cAMP inducible beta-galactosidase reporter gene were thawed, centrifuged, DMSO containing media removed, and then seeded with fresh culture media into clear 384-well tissue culture treated plates (BD #353961) at a concentration of 10K cells/well. Prior to assay, these plates were cultured for two days at 37° C., 5% CO 2 , 90% Rh. On the day of the functional assay, culture media was removed and replaced with 45 uL assay medium (Hams/F-12 Modified (Mediatech #10-080CV) supplemented w/0.1% BSA). Test compounds were diluted and 11 point curves created at a 1000× concentration in 100% DMSO. Immediately after addition of assay media to the cell plates, 50 nL of the appropriate test compound antagonist or agonist control curves were added to cell plates using a Cartesian Hummingbird. Compound curves were allowed to incubate at room temperature on cell plates for approximately 15 minutes before addition of a 15 nM NECA (Sigma E2387) agonist challenge (5 uL volume). A control curve of NECA, a DMSO/Media control, and a single dose of Forskolin (Sigma F3917) were also included on each plate. After additions, cell plates were allowed to incubate at 37° C., 5% CO 2 , 90% Rh for 5.5-6 hours. After incubation, media was removed, and cell plates were washed 1×50 uL with DPBS w/o Ca & Mg (Mediatech 21-031-CV). Into dry wells, 20 uL of 1× Reporter Lysis Buffer (Promega E3971 (diluted in dH 2 O from 5× stock)) was added to each well and plates frozen at −20° C. overnight. For β-galactosidase enzyme calorimetric assay, plates were thawed out at room temperature and 20 μL 2× assay buffer (Promega) was added to each well. Color was allowed to develop at 37° C., 5% CO 2 , 90% Rh for 1-1.5 h or until reasonable signal appeared. The calorimetric reaction was stopped with the addition of 60 μL/well 1M sodium carbonate. Plates were counted at 405 nm on a SpectraMax Microplate Reader (Molecular Devices). Data was analyzed in Microsoft Excel and IC/EC50 curves were fit using a standardized macro.
Adenosine A1 Receptor Functional Assay (A1GAL2)
[0178] To initiate the functional assay, cryopreserved CHO-K1 cells overexpressing the human adenosine A1 receptor and containing a cAMP inducible beta-galactosidase reporter gene were thawed, centrifuged, DMSO containing media removed, and then seeded with fresh culture media into clear 384-well tissue culture treated plates (BD #353961) at a concentration of 10K cells/well. Prior to assay, these plates were cultured for two days at 37° C., 5% CO 2 , 90% Rh. On the day of the functional assay, culture media was removed and replaced with 45 uL assay medium (Hams/F-12 Modified (Mediatech #10-080CV) supplemented w/0.1% BSA). Test compounds were diluted and 11 point curves created at a 1000× concentration in 100% DMSO. Immediately after addition of assay media to the cell plates, 50 nL of the appropriate test compound antagonist or agonist control curves were added to cell plates using a Cartesian Hummingbird. Compound curves were allowed to incubate at room temperature on cell plates for approximately 15 minutes before addition of a 4nM r-PIA (Sigma P4532)/1 uM Forskolin (Sigma F3917) agonist challenge (5 uL volume). A control curve of r-PIA in 1 uM Forskolin, a DMSO/Media control, and a single dose of Forskolin were also included on each plate. After additions, cell plates were allowed to incubate at 37° C., 5% CO 2 , 90% Rh for 5.5-6 hours. After incubation, media was removed, and cell plates were washed 1×50 uL with DPBS w/o Ca & Mg (Mediatech 21-031-CV). Into dry wells, 20 uL of 1× Reporter Lysis Buffer (Promega E3971 (diluted in dH 2 O from 5× stock)) was added to each well and plates frozen at −20° C. overnight. For β-galactosidase enzyme calorimetric assay, plates were thawed out at room temperature and 20 μL 2× assay buffer (Promega) was added to each well. Color was allowed to develop at 37° C., 5% CO 2 , 90% Rh for 1-1.5 h or until reasonable signal appeared. The calorimetric reaction was stopped with the addition of 60 μL/well 1M sodium carbonate. Plates were counted at 405 nm on a SpectraMax Microplate Reader (Molecular Devices). Data was analyzed in Microsoft Excel and IC/EC50 curves were fit using a standardized macro.
[0000]
A2a ASSAY DATA
Example
A2AGAL2 Ki (μM)
A2A-B Ki (μM)
A1GAL2 Ki (μM)
1
0.184035
0.597998
2
0.0378791
0.0219989
0.899911
3
0.0249173
0.0455302
0.851138
4
0.0809468
1.42692
5
0.0109698
0.0120005
0.167456
6
0.360662
>10
7
0.19333
~0.92747
8
0.222075
>1.06832
9
0.094189
0.60256
10
0.0346976
0.0525775
11
0.0179143
0.530274
12
0.0218776
0.442588
13
0.0991517
>1.00069
14
1.55203
>0.610098
15
0.0289668
0.113214
16
0.115213
0.466874
17
0.528445
>0.923422
18
0.194581
>0.947982
19
0.014184
0.0218726
20
0.10932
0.507926
21
0.309742
0.026934
22
23
0.366606
>1.31432
24
0.136899
0.422085
25
0.287012
>1.31432
26
0.092918
>1.31432
27
0.0402532
0.244512
28
0.159845
>1.03825
29
0.236265
>1.06832
30
0.23632
0.522156
31
32
1.24137
>1.03825
33
0.0818653
0.978363
34
[0179] A blank space indicates that no data was available.
[0180] While the foregoing specification teaches the principles of the present invention, with examples provided for the purpose of illustration, it will be understood that the practice of the invention encompasses all of the usual variations, adaptations and/or modifications as come within the scope of the following claims and their equivalents.
[0181] All publications disclosed in the above specification are hereby incorporated by reference in full.
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This invention relates to a novel thieno[2,3-d]pyrimidine, A, and its therapeutic and prophylactic uses, wherein R 1 and R 2 are defined in the specification. Disorders treated and/or prevented include Parkinson's Disease.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/273,181, filed on Mar. 1, 2001.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of CXC chemokine receptor antagonists.
BACKGROUND OF THE INVENTION
[0003] The CXC chemokines that possess the receptor-signaling glutamic acid-lysine-arginine (ELR) motif (e.g., CXCL1/GRO, CXCL8/IL-8; Baggiolini, M. 1998. Nature. 392:565-568) are important to the influx of inflammatory cells that mediates much of the pathology in multiple settings, including ischemia-reperfusion injury (Sekido, N. et al. 1993. Nature. 365:654-657; Villard, J. et al. 1995. Am. J. Respir. Crit. Care Med. 152:1549-1554), endotoxemia-induced acute respiratory distress syndrome (ARDS; Mukaida, N. et al. 1998. Inflamm. Res. 47 suppl. 3):S151-157), arthritis, and immune complex-type glomerulonephritis Harada, A. et al. 1996. Inflamm. Res. 2:482-489). For instance, inappropriately released hydrolytic enzymes and reactive oxygen species from activated neutrophils initiate and/or perpetuate the pathologic processes. On the other hand, during most bacterial infections this chemokine response represents a critical first line of defense, but even here ELR + CXC chemokine responses can, via their abilities to activate inflammatory cells displaying the CXCR1 and CXCR2 receptors, exacerbate the pathology. For example, during experimental ‘cecal puncture and ligation’ sepsis, neutralization of MIP-2 reduces mouse mortality from 85 to 38% (Walley, K. R. et al. 1997. Infect. Immun. 65:3847-3851). And experimental treatments that eliminate circulating neutrophils ameliorate the pathology of pneumonic mannheimiosis (Slocombe, R. et al. 1985. Am. J. Vet. Res. 46:2253), wherein CXCL8 expression in the airways variably effects the neutrophil chemoattraction. Caswell, J. L. et al. 1997. Vet. Pathol. 35:124-131; Caswell, J. L. et al. 2001. Canad. J. Vet. Res. 65:229-232). Despite the critical importance of these chemokine responses in many settings, wayward inflammatory cell responses are sufficiently damaging that the development of therapeutic tools with which we can block ELR + chemokines has become a research priority (Baggiolini, M., and B. Moser. 1997. J. Exp. Med. 186:1189-1191).
[0004] The ‘ELR’ chemokines chemoattract and activate inflammatory cells via their CXCR1 and CXCR2 receptors (Baggiolini, 1998; Ahuja, S. K., and P. M. Murphy. 1996. J. Biol. Chem. 271:20545-20550). The CXCR1 is specific for CXCL8 and CXCL6/granulocyte chemotactic protein-2 (GCP-2), while the CXCR2 binds CXCL8 with high affinity, but also macrophage inflammatory protein-2 (MIP-2), CXCL1, CXCL5/ENA-78, and CXCL6 with somewhat lower affinities (see, for example, Baggiolini and Moser, 1997). CXCL8 signaling in cell lines transfected with the human CXCR1 or CXCR2 induces equipotent chemotactic responses (Wuyts, A. et al. 1998. Eur. J. Biochem. 255:67-73; Richardson, R. et al. 1998. J. Biol. Chem. 273:23830 - 23836), and while neutrophil cytosolic free Ca ++ changes and cellular degranulation in response to CXCL8 are also mediated by both receptors, the respiratory burst and activation of phospholipase D reportedly depend exclusively on the CXCR1 (Jones, S. A. et al. 1996. Proc. Natl. Acad. Sci. U.S A. 93:6682-6686.). On the other hand, it has been reported that a non-peptide antagonist of the CXCR2, but not the CXCR1, antagonizes CXCL8-mediated neutrophil chemotaxis, but not cellular activation (White, J. R. et al. 1998. J. Biol. Chem. 273:10095-10098.). Finally, there is abundant evidence that chemokines are most often redundantly expressed during inflammatory responses (see, for example, Caswell et al., 1997). But, despite active research in the field, no CXC chemokine antagonists are known in the prior art that are effective in suppressing adverse inflammatory cell activity induced by either ELR-CXC chemokine receptor.
SUMMARY OF THE INVENTION
[0005] Compositions of the present invention include novel ELR-CXC chemokine antagonist proteins that are capable of binding to CXCR1 or CXCR2 receptors in mammalian inflammatory cells. These include antagonists that are capable of high-affinity binding, wherein “high-affinity” refers to the antagonist's affinity for the receptor being at least about one order of magnitude greater than that of the wild-type chemokine agonist. The novel antagonist proteins also include those that are substantially equivalent (that is, those that contain amino acid substitutions, additions and deletions that do not delete the CXCR1 and CXCR2 binding functions) to a wild-type bovine CXCL8 protein (illustrated herein as the amino acid sequence of SEQ ID NO:2) and also bear a truncation of the first two amino acid residues along with substitutions of Lys11 with Arg and Gly31 with Pro. Analogues of this CXCL (3-73) K11R/G31P are also included, namely CXCL (3-73) K11R/G31P/P32G and CXCL (3-73) K11R/T12S/H13F/G31P. In addition, compounds having a three dimensional structure resulting in high affinity binding to CXCR1 or CXCR2 receptors in mammalian inflammatory cells.
[0006] Other compositions of the invention are novel polynucleotides and polypeptides relating to these proteins. One such novel polynucleotide is the nucleotide sequence identified herein as SEQ ID NO:4, while one such novel polypeptide is the amino acid sequence identified herein as SEQ ID NO:1. Further, the invention includes vectors comprising the novel polynucleotides, and expression vectors comprising the novel polynucleotides operatively associated with regulatory sequences controlling expression of the polynucleotides. Similarly, gene fusions comprising affinity handles and the novel polynucleotides are included in the invention, as are the resultant vectors and expression vectors containing such gene fusions.
[0007] The invention also includes hosts genetically engineered to contain the novel polynucleotides as well as hosts genetically engineered to contain the novel polynucleotides operatively associated with regulatory sequences, that is, associated with regulatory sequences in such a fashion that the regulatory sequences control expression of the novel polynucleotides. Also included are hosts containing gene fusions, either associated with regulatory sequences in such a fashion that the regulatory sequences control the expression of the gene fusions, or in the absence of such regulatory sequences. These hosts may be viruses or cells, wherein the latter include without limitation bacteria, yeast, protozoa, fungi, algae, plant cells, and animal cells and higher organisms derived therefrom.
[0008] The invention additionally comprises uses of the novel polypeptides in treating CXC chemokine-mediated pathologies involving the CXCR1 or CXCR2 receptors in mammals. Likewise, the invention includes methods of treating ELR-CXC chemokine-mediated pathologies involving the CXCR1 or CXCR2 receptors, comprising administering to the afflicted mammal an effective amount of one of the novel polypeptides. Pharmaceutical compositions comprising a biologically-active amount of one of the novel polypeptides are also included in the invention.
[0009] Finally, methods of producing and purifying the novel polypeptides are also included in the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1. The G31 P analogue of CXCL8 (3-73) K11R is a potent inhibitor of CXCL8-binding to peripheral blood neutrophils. Bovine peripheral blood neutrophils (87-93%purity) were (upper panel) exposed at 4° C. for 2 h to CXCL8 (3-73) K11R analogues (10 ng/ml) or medium (med) alone, then washed and similarly incubated with biotinylated CXCL8 ( biot CXCL8; 1000 ng/ml or 129 nM). These levels of CXCL8 approximate those found in the lung tissues of animals with pneumonic pasteurellosis (ref. 8, 9). The levels of biot CXCL8 binding to the cells were determined using ELISA technology. The depicted amino acid substitutions within CXCL8 (3-73) K11R included: G31P; P32G; T12S/H13P/G31P; and T12S/H13P/G31P/P32G. The G31P, but not the P32G, analogue was a highly effective antagonist of CXCL8 binding to the cells. With both the G31P and P32G analogues, additional substitutions of T12S and H13F reduced their CXCL8 antagonist activities (lower panel). Neutrophils were exposed simultaneously for 45 min at 4° C. to varying concentrations of CXCL8 (3-73) K11R/G31P or unlabeled CXCL8 and 20 pM 125 ICXCL8. This level of 125 I-CXCL8 was chosen as nearly saturating for the cell's high affinity CXCL8 receptors (data not shown). The levels of cell-associated 125 I-CXCL8 were assessed using a counter. The data clearly indicate that CXCL8 (3-73) K11R/G31P had a substantially higher affinity for the neutrophils than CXCL8.
[0011] [0011]FIG. 2. CXCL8 (3-73) K11R/G31P is not an agonist of neutrophil chemoattraction responses or −glucuronidase release. CXCL8 and the G31P, P32G, or combined G31P/P32G analogues of CXCL8 (3-73) K11R were tested for their neutrophil agonist activities, using freshly purified bovine peripheral blood neutrophils. (upper panel) The chemotactic responses to each protein were tested in 30 min microchemotaxis assays and the results expressed as the mean (+/− SEM) number of cells/40× objective microscope field, as outlined in the methods section. Both the G31P and G31P/P32G analogues displayed little discemable chemotactic activity, while the P32G analogue stimulated substantial responses at 100 ng/ml. (lower panel) The neutrophils were exposed to varying doses of each analogue for 30 min, then the cellular secretion products were assayed for −glucuronidase using the chromogenic substrate p-nitrophenyl—D-glucuronide, as presented in the methods section. The total cellular stores of −glucuronidase were determined from aliquots of cells lysed with Triton-X-100. The enzyme release with each treatment is expressed as the percent of the total cellular stores. None of the analogues had substantial agonist activity, although CXCL8 itself did induce significant enzyme release. The positive control treatment with phorbol-12,13-myristate acetate and calcium ionophore A23187 induced 42+/−6% enzyme release.
[0012] [0012]FIG. 3 CXCL8 (3-73) K11R-G31P is a highly effective antagonist ELR-CXC chemokine-medicated neutrophil chemoattraction. The ability of CXCL8 (3-73) K11R/G31P to block chemotactic responses of bovine neutrophils to several ELR-CXC chemokines was measured using 20 min microchemotaxis assays. (left panel) The cells were simultaneously exposed to CXCL8 (1 μg/ml) and varying concentrations of the analogue. The number of cells that responded to the CXCL8 was assessed by direct counting of the chemotaxis assay membranes, as in FIG. 2. CXCL8 (3-73) K11R/G31P was a highly effective competitive inhibitor of the cell's responses to CXCL8. (middle panel) Dose-response curves for chemoattraction of bovine neutrophils by human CXCL1, CXCL5, or CXCL8. Each chemokine displayed a biphasic activity pattern, with maxima at 1-10 ng/ml and at 1 μg/ml. (right panel) The ability of CXCL8 (3-73) K11R/G31P to block the cell's responses to 1 ng/ml of human CXCL5 or CXCL1 or 10 ng/ml of human CXCL8 was assessed as above. CXCL8 (3-73) K11R/G31P effectively antagonized each ELR-CXC chemokine, with complete inhibition being achieved with from 3-20 nM CXCL8 (3-73) K11R/G31P.
[0013] [0013]FIG. 4. CXCL8 (3-73) K11R-G31P blocks the activities of CXCL8 and non-CXCL8 chemoattractants expressed within pneumonic airways or in endotoxin-induced mastitis. The effects of monoclonal anti-IL8 antibody 8B6 or CXCL8 (3-73) K11R-G31P on neutrophil responses to the chemoattractants expressed within the airways of animals with pneumonic pasteurellosis or in the mammary cisterns of cattle with endotoxin-induced mastitis were assessed as in FIG. 3. (A) Diluted (1:10) bronchoalveolar lavage fluids (BALF) from lesional lung lobes of pneumonic cattle (PNEUMONIA) or teat cistern lavage fluids from cattle with mastitis (MASTITIS) were tested as is (none) or after treatment with either anti-CXCL8 MAb 8B6 (5 μg/ml) or CXCL8 (3-73) K11R/G31P (G31P; 1 or 10 ng/ml) for their chemotactic activities compared to medium alone. With both samples, the Mab 8B6 antibodies by themselves neutralized 74% of the chemotactic activities in the samples, while CXCL8 (3-73) K11R/G31P reduced the responses by 93-97%. (B) In order to confirm these results using an alternate strategy, we next absorbed lesional BAL fluids with monoclonal antibody 8B6-immunoaffinity matrices, removing >99% of their content of CXCL8, then tested both their residual chemotactic activities and the ability of CXCL8 (3-73) K11R/G31P to antagonize these residual non-CXCL8 chemotactic activities. There was a dose-dependent inhibition of the total and residual chemotactic activities in the samples, indicating that both CXCL8 and non-CXCL8 chemoattractants are expressed in these lesions.
[0014] [0014]FIG. 5. CXCL8 (3-73) K11R-G31P can ablate endotoxin-induced inflammatory responses in vivo. Two week-old Holstein calves were tested for their neutrophilic inflammatory responses to intradermal endotoxin (1 μg/site) challenge before and at various time after intravenous (i.v.), subcutaneous (subcutan.), or intramuscular (i.m.) injection of CXCL8 (3-73) K11R-G31P (75 μg/kg). Fifteen hour endotoxin reaction site biopsies were obtained at 0, 16, 48 and 72 h post-treatment and processed for histopathologic assessment of the neutrophil response, as determined by counting the numbers of neutrophils in nine 40× objective microscope fields per section. (left panel) Photomicrographs of the tissue responses to endotoxin challenge around blood vessels within the reticular dermis prior to (0 h) and 48 h post-treatment. Large numbers of neutrophils accumulated around the vasculature within the reticular dermis in the pre-, but not post-treatment tissues. (B) Graphic presentation of the neutrophil responses to endotoxin challenge either before (0 h) or after (16, 48, 72 h) CXCL8 (3-73) K11R-G31P delivery by each route. ** or ***=p 0.01 or 0.001, respectively, relative to the internal control pretreatment responses.
[0015] [0015]FIG. 6 Eosinophils purified from the blood of atopic asthmatic or atopic non-asthmatic donors (left panels) or a subject with a hypereosinophilia (right panel) were assessed for their responses to recombinant human CXCL8, CXCL5, or CCL11, in the presence or absence of the indicated doses of recombinant bovine CXCL8 (3-73) K11R/G31P (G31P). Low doses of G31P were able to block the responses of these cells to each of the CXCR1 and CXCR2 ligands, but had no effect on the eosinophil's responses to the unrelated CCR3 ligand CCL11/eotaxin.
[0016] [0016]FIG. 7 Neutrophils from the peripheral blood of a healthy donor were tested for their responses to recombinant human CXCL8 or CXCL5 in the presence or absence of bovine CXCL8 (3-73) K11R/G31P (G31P; 10 ng/ml). G31P blocked the neutrophil's responses to both ligands.
DETAILED DESCRIPTION OF THE INVENTION
[0017] (The following abbreviations are used throughout this disclosure: ARDS, acute respiratory distress syndrome; BALF, bronchoalveolar lavage fluid(s); BHR, Bolton-Hunter Reagent; CXCR1, CXCR2, CXCL8 receptors A, B, respectively; ELR, glutamic acid-lysine-arginine motif; CXCL1, growth-related oncogenealpha; CXCL4, platelet factor-4; CXCL5, epithelial-derived neutrophil activator-78; CXCL6, granulocyte chemotactic protein-2; CXCL8, interleukin-8; fMLP, formyl methionyl-leucylproline bacterial tripeptide; IPTG, isopropyl-thio-D-galactopyranoside; MIP-2, macrophage inflammatory protein-2; PMSF, phenylmethylsulfonyl fluoride; TMB, tetramethylbenzidine.)
[0018] When amino terminal truncation of bovine CXCL8 is combined with a lysine to arginine substitution at amino acid 11 (i.e., CXCL8 (3-73) K11R), dramatic increases in CXCR1 and CXCR2 receptor affinity are evident, such that CXCL8 (3-73) K11R competitively inhibits the binding of multiple ligands to both receptors (Li, F., and J. R. Gordon. 2001. Biochem. Biophys. Res. Comm. 286:595-600., hereby incorporated by reference. Further truncation into the receptor-signaling ELR motif (e.g., amino acids 4-6 of human CXCL8) of some CXC chemokines can transform them into mild (CXCL8 (6-72) ) to moderate (CXCL1 (8-73) ) receptor antagonists (McColl and Clark Lewis 1999; Moser, B. et al. 1993. J. Biol. Chem. 268:7125-7128). As disclosed herein, the introduction into bovine CXCL8 (3-73) K11R of a second amino acid substitution, glycine 31 to a proline residue (i.e., CXCL8 (3-73) K11R/G31P), renders this CXCL8 analogue a very high affinity antagonist of bovine and human ELR-CXC chemokine responses. It fully antagonizes the entire array of ELR-CXC chemokines expressed within bacterial or endotoxin-induced inflammatory foci and blocks endotoxin-induced inflammation in vivo.
[0019] Although the following discussion deals primarily with bovine neutrophils, other mammalian (including human) inflammatory cells also display CXCR1 and CXCR2 receptors (see, for example, Benson, M. et al. 1999. Pediatr. Allergy Immunol. 10:178-185) and so are vulnerable to inhibition by CXCL8 (3-73) K11R/G31P. Accordingly, the present invention has broad applicability to mammalian ELR-CXC chemokine-mediated pathologies.
[0020] In an alternate embodiment of the invention, it is envisioned that compounds having the same three dimensional structure at the binding site may be used as antagonists. Three dimensional analysis of chemical structure is used to determine the structure of active sites, including binding sites for chemokines. Chemical leads with high throughput screening have been used to generate and chemically optimize a selective antagonist of the CXCR2 (J Biol Chem, 1998, 273:10095, herein incorporated by reference). A similar approach was also used to generate a CCR3 antagonist (J Biol Chem, 2000, 275:36626, herein incorporated by reference).
[0021] Wells et al (J Leuk biol, 1996, 59:53, herein incorporated by reference), has employed nuclear magnetic resonance spectroscopy (NMR) to detail the three dimensional structure of ligands for CXCR, including both ELR and non-ELR CXC chemokines. With their NMR information, Wells et al generated multiple substitutions within the receptor binding sites of multiple chemokines, such that they could substantially alter the ligands' receptor specificities.
[0022] Material and Methods
[0023] Reagents & supplies. The following reagents were purchased commercially: glutathione-Sepharose, the expression vector pGEX-2T, Sephadex G-25 (Amersham-Pharmacia-Biotech, Baie d'Urfé, PQ), Bolton-Hunter reagent, a protein biotinylation kit (Pierce Scientific, Rockford, Ill.), the sequencing vector pBluescript II KS, Pfu Turbo™ DNA polymerase (Stratagene, La Jolla, Calif.), a site-directed mutagenesis kit (QuickChange™; Boerhinger-Mannheim Canada, Laval, PQ), aprotinin, benzene, calcium ionophore A23187, chloramine T, cytochalasin B, dimethylformamide, endotoxin ( Escherichia coli lipopolysaccharide, serotype 0127B8), isopropyl-thio-D-galactopyranoside (IPTG), leupeptin, p-nitrophenyl—D-glucuronide, mineral oil, silicon oil, tetramethylbenzidine (TMB), phenylmethylsulfonyl fluoride (PMSF), phorbol-12,13-myristate acetate (PMA), and Triton X-100 (Sigma Chemical Co, Mississauga, ON), a Diff-Quick staining kit (American Scientific Products, McGaw Pk, Ill.), human CXCL1, CXCL5, and CXCL8 (R & D Systems Inc, Minneapolis, Minn.), horse radish peroxidase (HRP)-conjugated anti-rabbit Ig (Zymed, South San Francisco, Calif.), DMEM, HBSS (Gibco, Grand Island, N.Y.), HRP-streptavidin (Vector Labs, Burlingame, Calif.), ABTS enzyme substrate (Kirkegaard & Perry Labs, Gaithersburg, Md.), bovine serum albumin (BSA), and Lymphocyte Separation Medium (ICN Pharmaceuticals, Aurora, Ill.).
[0024] Generation of CXCL8 (3-73) K11R analogues. The high affinity CXCR1/CXCR2 ligand CXCL8 (3-73) K11R, and its T12S/H13F analogue were generated in accordance with the methods described in Li and Gordon (2001, supra). The Gly31Pro (G31P), Pro32Gly (P32G), and G31P/P32G analogues of these proteins were similarly generated by site-directed mutagenesis using PCR with the appropriate forward and reverse oligonucleotide primers (Table 1). The products from each reaction were digested with DpnI, ligated into the vector pGEX-2T, transfected into HB101 cells, and their sequences verified commercially (Plant Biotechnology Institute, Saskatoon). Briefly, the recombinant bacteria were lysed in the presence of a protease inhibitor cocktail (2 mM PMSF, 2 μg/ml aprotinin, and 2 μg/ml leupeptin) and the recombinant fusion proteins in the supernatants purified by affinity chromatography, using glutathione-Sepharose beads in accordance with the methods of Caswell et al. (Caswell, J. L., D. M. Middleton, and J. R. Gordon. 1998. Vet. Immunol. Immunopath. 67:327-340.). The CXCL8 (3-73) K11R analogues were cleaved from the GST fusion proteins by thrombin digestion, dialysed against phosphate buffered saline (PBS), run through commercial endotoxin-removal columns, and then characterized by polyacrylamide gel electrophoresis (PAGE) and Western blotting with a goat anti-bovine CXCL8 antibody (provided by Dr. M. Morsey). Each purified analogue had a molecular mass of 8 kDa, was specifically recognized by the anti-CXCL8 antibody in the Western blotting, and had a relative purity of 96%, as determined by densitometric analysis of the PAGE gels.
[0025] Labeling of the recombinant proteins. We used biot CXCL8 for the initial surveys of analogue binding to neutrophils and 125 I-CXCL8 for the later stage assays of relative receptor affinity. CXCL8 was biotinylated and the levels of biotin substitution determined using a commercial kit, as noted in Li and Gordon (2001, supra). The biot CXCL8 was substituted with 2.15 moles of biotin per mole of CXCL8. CXCL8 was radiolabeled with 125 I using the Bolton-Hunter Reagent (BHR) method, as noted in detail (Li and Gordon 2001, supra). The labeled protein was separated from the unincorporated 125 I-BHR by chromatography on Sephadex G50, and the labeled CXCL8 characterized for its relative affinity for neutrophils and the time required to achieve binding equilibrium, as noted in Li and Gordon (2001, supra).
[0026] CXCL8 (3-73) K11R analogue binding assays. Cells (85-93% neutrophils) were purified from the blood of cattle in accordance with the Caswell method (Caswell, J. L. et al. 1998. Vet. Immunol. Immunopath. 67:327-340). In preliminary experiments, we determined that none of our analogues affected the viability of neutrophils, as determined by trypan blue dye exclusion. For the broad analogue surveys, neutrophils in HBSS/0.5% BSA were incubated for 2 h at 4° C. with the analogue, washed in cold DMEM, and then incubated for another 2 h at 4° C. with biot CXCL8 (1000 ng/ml). The cell-associated biotin was detected by incubating the washed cells with alkaline phosphatase-conjugated streptavidin (1:700 dilution) and then with ABTS enzyme substrate. The OD 405 of the samples was determined using an ELISA plate reader. Medium-treated neutrophils routinely bound sufficient biot CXCL8 to generate an OD 405 of 0.5-0.6.
[0027] For the in-depth studies with CXCL8 (3-73) K11R/G31P, we used 125 I-CXCL8 in binding inhibition assays with unlabeled CXCL8 or CXCL8 (3-73) K11R/G31P. In preliminary experiments we determined that the binding equilibrium time of neutrophils for 125 I-CXCL8 was 45 min and that 20 pM 125 I-CXCL8 just saturated the cell's high affinity receptors. Thus, in our assays, 10 6 purified neutrophils were incubated for 45 min on ice with 20 pM 125 I-CXCL8 and varying concentrations of unlabeled competitor ligand. The cells were then sedimented through 6% mineral oil in silicon oil and the levels of cell-associated radio-ligand determined using a counter. The non-specific binding of 125 ICXCL8 to the cells was assessed in each assay by including a 200-fold molar excess of unlabeled ligand in a set of samples. This value was used to calculate the percent specific binding (Coligan, J., A. Kruisbeek, D. Margulies, E. Shevach, and W. Strober. 1994. Current Protocols in Immunology. John Wiley & Sons, New York).
[0028] Neutrophil −glucuronidase release assay. The neutrophil −glucuronidase assay has been reported in detail (Li and Gordon 2001, supra). Briefly, cytochalasin B-treated neutrophils were incubated for 30 min with the CXCL8 analogues, then their secretion products assayed calorimetrically for the enzyme. −Glucuronidase release was expressed as the percent of the total cellular content, determined by lysing medium-treated cells with 0.2% (v/v) Triton X- 100. Neutrophil challenge with the positive control stimulus PMA (50 ng/ml) and A23187 (1 μg/ml) induced 42+/−6% release of the total cellular −glucuronidase stores.
[0029] Samples from inflammatory lesions. We obtained bronchoalveolar lavage fluids (BALF) from the lungs of cattle (n=4) with diagnosed clinical fibrinopurulent pneumonic mannheimiosis (Caswell et al., 1997), as well as teat cistern wash fluids from cattle (n=4) with experimental endotoxin-induced mastitis (Waller, K. P. 1997. Vet. Immunol. Immunopathol. 57:239-251). In preliminary dose-response experiments we determined that 5 μg of endotoxin induced a strong (70-80% maximal) mammary neutrophil response. Thus, in the reported experiments mastitis was induced by infusion of 5 μg of endotoxin or carrier medium alone (saline; 3 ml volumes) into the teat cisterns of nonlactating Holstein dairy cows, and 15 h later the infiltrates were recovered-from the cisterns by lavage with 30 ml HBSS. The cells from the BALF and teat cistern wash fluids were sedimented by centrifugation and differential counts performed. Untreated and CXCL8-depleted (below) wash fluids were assessed for their chemokine content by ELISA (CXCL8 only) and chemotaxis assays.
[0030] Neutrophil chemotaxis assays. Microchemotaxis assays were run in duplicate modified Boyden microchemotaxis chambers using polyvinylpyrrolidone-free 5 μm pore-size polycarbonate filters, in accordance with known methods (Caswell et al.,1998; Cairns, C. M. et al. 2001. J. Immunol. 167:57-65). For each sample, the numbers of cells that had migrated into the membranes over 20-30 min were enumerated by direct counting of at least nine 40× objective fields, and the results expressed as the mean number of cells/40× field (+/− SEM). The chemoattractants included bovine or human CXCL8, human CXCL5 and CXCL1, pneumonic mannheimiosis BALF and mastitis lavage fluids (diluted 1:10-1:80 in HBSS), while the antagonists comprised mouse anti-ovine CXCL8 antibody 8M6 (generously provided by Dr. P. Wood, CSIRO, Australia) or the CXCL8 (3-73) K11R analogues. In some assays we preincubated the samples with the antibodies (5 μg/ml) for 60 min on ice (Gordon, J. R. 2000. Cell Immunol. 201:42-49). In others we generated CXCL8-specific immunoaffinity matrices with the 8M6 antibodies and protein-A-Sepharose beads and used these in excess to absorb the samples (Caswell et al.,1997; Gordon, J. R., and S. J. Galli. 1994. J. Exp. Med. 180:2027-2037); the extent of CXCL8 depletion was confirmed by ELISA of the treated samples. For assays with the recombinant antagonists, the inhibitors were mixed directly with the samples immediately prior to testing.
[0031] CXCL8 ELISA. For our ELISA, MAb 8M6 was used as the capture antibody, rabbit antiovine CXCL8 antiserum (also from P. Wood, CSIRO) as the secondary antibody, and HRPconjugated anti-rabbit Ig, and TMB as the detection system, as noted in Caswell et al. (1997). Serial dilutions of each sample were assayed in triplicate, and each assay included a recombinant bovine CXCL8 standard curve.
[0032] CXCL8 (3-73) K11R/G31P blockade of endotoxin responses in vivo. We used a sequential series of 15 h skin tests to test the ability of CXCL8 (3-73) K11R/G31P to block endotoxininduced inflammatory responses in vivo. For each test, we challenged 2 week-old healthy Holstein cows intradermally with 1 μg endotoxin in 100 μl saline, then 15 h later took 6 mm punch biopsies under local anaesthesia (lidocaine) and processed these for histopathology (Gordon and Galli, 1994). Following the first (internal positive control) test, we injected each animal subcutaneously, intramuscularly, or intravenously with CXCL8 (3-73) K11R/G31P (75 μg/kg) in saline, then challenged them again with endotoxin, as above. The animals were challenged a total of 4 times with endotoxin, such that 15 h reaction site biopsies were obtained at 0, 16, 48, and 72 h post-treatment. The biopsies were processed by routine methods to 6 μm paraffin sections, stained with Giemsa solution, and examined in a blinded fashion at 400− magnification (Gordon and Galli, 1994; Gordon, J. R. 2000. J. Allergy Clin. Immunol. 106:110-116). The mean numbers of neutrophils per 40× objective microscope field were determined at three different depths within the skin, the papillary (superficial), intermediate, and reticular (deep) dermis.
[0033] Statistical analyses. Multi-group data were analyzed by ANOVA and post-hoc Fisher protected Least Significant Difference (PLSD) testing, while two-group comparisons were made using the students t-test (two-tailed). The results are expressed as the mean +/− SEM.
[0034] Results
[0035] CXCL8 (3-73) K11R/G31P competitively inhibits CXCL8 binding to neutrophils. We surveyed the ability of each CXCL8 (3-73) K11R analogue to bind to the CXCL8 receptors on neutrophils, and thereby compete with CXCL8 as a ligand. In our initial surveys, we employed biot CXCL8 binding inhibition assays, incubating the cells with the analogues (10 ng/ml) for 2 h at 4° C. prior to exposure to biot CXCL8 (1 μg/ml). This level of CXCL8 approximates those found in the lung tissues of sheep with experimental pneumonic mannheimiosis (Caswell, J. L. 1998. The role of interleukin-8 as a neutrophil chemoattractant in bovine bronchopneumonia. Ph.D. thesis, Department of Veterinary Pathology, University of Saskatchewan). We found that CXCL8 (3-73) K11R/G31P was a potent antagonist of CXCL8 binding in this assay (FIG. 1), such that 10 ng/ml of CXCL8 (3-73) K11R/G31P blocked 95% of subsequent biot CXCL8 binding to the cells. When tested at this dose, CXCL8 (3-73) K11R/P32G blocked only 48% of CXCL8 binding, while unlabeled CXCL8 itself competitively inhibited 30% of biot CXCL8 binding. Introduction into CXCL8 (3-73) K11R/G31P or CXCL8 (3-73) K11R/P32G of additional amino acid substitutions at Thr12 and His13 substantially reduced the antagonist activities of the analogues (FIG. 1). This data clearly suggests that pre-incubation of neutrophils with CXCL8 (3-73) K11R/G31P strongly down-regulates subsequent binding of CXCL8.
[0036] In order to more finely map the ability of CXCL8 (3-73) K11R/G31 to inhibit the binding of CXCL8, in our next set of experiments we simultaneously exposed the cells to 125 ICXCL8 and varying doses of CXCL8 (3-73) K11R/G31P or unlabeled CXCL8. We found that CXCL8 (3-73) K11R/G31P was about two orders of magnitude more effective than wildtype CXCL8 in inhibiting the binding of 20 pM 125 I-CXCL8 to the cells (FIG. 1). The concentration for inhibiting 50% of labeled ligand binding (IC 50 ) was 120 pM for unlabelled CXCL8, and 4 pM for CXCL8 (3-73) K11R/G31P. This data suggests that CXCL8 (3-73) K11R/G31P is a very potent competitive inhibitor of CXCL8 binding to neutrophils.
[0037] CXCL8 (3-73) K11R/G31P does not display neutrophil agonist activities. While CXCL8 (3-73) K11R/G31P was certainly a high affinity ligand for the neutrophil CXCL8 receptors, it would equally well do so as an agonist or an antagonist. Thus our next experiments addressed the potential agonist activities of the CXCL8 (3-73) K11R analogues we generated, as measured by their abilities to chemoattract these cells or induce release of the neutrophil granule hydrolytic enzyme −glucuronidase in vitro (FIG. 2). We found that even at 100 ng/ml, CXCL8 (3-73) K11R/G31P was a poor chemoattractant, inducing 13.9+/−4% or 5.4+/−2% of the responses induced by 1 or 100 ng/ml CXCL8 (p<0.001), respectively. At 100 ng/ml, the CXCL8 (3-73) K11R/P32G analogue induced a response that was fairly substantial (38.3+/−2% of the CXCL8 response), while the combined CXCL8 (3-73) K11R/G31P/P32G analogue also was not an effective chemoattractant. When we assessed their abilities to induce −glucuronidase release, we found that none of the CXCL8 (3-73) K11R analogues was as effective as CXCL8 in inducing mediator release. Indeed, we found only background release with any of them at 10 ng/ml, and at 100 ng/ml only CXCL8 (3-73) K11R/G31P/P32G induced significant neutrophil responses (FIG. 2). Given the combined CXCL8 competitive inhibition and neutrophil agonist data, from this point on we focused our attention on CXCL8 (3-73) K11R/G31P.
[0038] CXCL8 (3-73) K11R/G31P blocks neutrophil chemotactic responses to both CXCR1 and CXCR2 ligands. The most pathogenic effect of inappropriate ELR + chemokine expression is the attraction of inflammatory cells into tissues. Thus, we next assessed the impact of CXCL8 (3-73) K11R/G31P on the chemotactic responses of neutrophils to high doses of CXCL8 (FIG. 3). As predicted from our in vivo observations in sheep and cattle (33), 1 μg/ml (129 nM) CXCL8 was very strongly chemoattractive, but even very low doses of CXCL8 (3-73) K11R/G31P ameliorated this response. The addition of 12.9 pM CXCL8 (3-73) K11R/G31P reduced the chemotactic response of the cells by 33%. The IC 50 for CXCL8 (3-73) K11R/G31P under these conditions was 0.11 nM, while complete blocking of this CXCL8 response was achieved with 10 nM CXCL8 (3-73) K11R/G31P.
[0039] When we tested the efficacy of CXCL8 (3-73) K11R/G31P in blocking responses to more subtle bovine CXCL8 challenges, we also extended the study to assess the ability of CXCL8 (3-73) K11R/G31P to block neutrophil responses to human CXCL8 as well as to the human CXCR2-specific ligands CXCL1 and CXCL5. Each of these is expressed in the affected tissues of pancreatitis (Hochreiter, W. W. et al. 2000. Urology. 56:1025-1029) or ARDS (Villard et al., 1995) patients at 1-10 ng/ml. We found that bovine neutrophils were responsive to 1 ng/ml hCXCL1 or hCXCL5, and similarly responsive to 10 ng/ml hCXCL8 (FIG. 3), so we employed these doses to test the effects of CXCL8 (3-73) K11R/G31P on neutrophil responses of these ligands. The neutrophil responses to hCXCL1 and hCXCL5 were reduced to 50% by 0.26 and 0.06 nM CXCL8 (3-73) K11R/G31P, respectively, while their responses to hCXCL8 were 50% reduced by 0.04 nM CXCL8 (3-73) K11R/G31P (FIG. 3). This data indicates that CXCL8 (3-73) K11R/G31P can antagonize the actions of multiple members of the ELR-CXC subfamily of chemokines.
[0040] CXCL8 (3-73) K11R/G31P is an effective in vitro antagonist of the neutrophil chemokines expressed in bacterial pneumonia or mastitis lesions. We wished to test the extent to which our antagonist could block the array of neutrophil chemoattractants expressed within complex inflammatory environments in vivo. Thus, we chose two diseases in which chemokine-driven neutrophil activation contributes importantly to the progression of the pathology, mastitis and pneumonic mannheimiosis. We utilized an endotoxin model of mastitis (Persson, K. et al., 1993. Vet. Immunol. Immunopathol. 37:99-112), in which we infused 5 μg of endotoxin/teat cistern and 15 h later lavaged each cistern. Neutrophils comprised 82 and 6%, respectively, of the cells from endotoxin and saline-control cisterns, with the bulk of the remaining cells comprising macrophages. The diluted (1:10) wash fluids induced strong in vitro neutrophil chemotactic responses, and the addition of anti-CXCL8 antibodies to the samples maximally reduced these by 73+/−8% (FIG. 4A), relative to the medium control. On the other hand, the addition of 1 ng/ml of CXCL8 (3-73) K11R/G31P to the samples reduced their chemotactic activity by 97+/−3%.
[0041] Neutrophils also comprised 93+/−12% of the cells recovered from the BALF of cattle with advanced pneumonic mannheimiosis. When tested in vitro, these samples too were strongly chemotactic for neutrophils, and the addition of anti-CXCL8 antibodies maximally reduced their neutrophil chemotactic activities by 73+/−5% (FIG. 4A). Treatment of these BALF samples with 1 or 10 ng/ml of CXCL8 (3-73) K11R/G31P reduced the neutrophil responses by 75+/−9 or 93+/−9%, respectively, relative to the medium controls. This data suggests that CXCL8 (3-73) K11R/G31P blocks the actions of CXCL8 and non-CXCL8 chemoattractants in these samples.
[0042] In order to confirm these observations using an alternate strategy, we next depleted bacterial pneumonia BALF samples of CXCL8 using immunoaffinity matrices, then assessed the efficacy of CXCL8 (3-73) K11R/G31P in blocking the residual neutrophil chemotactic activities in the samples (FIG. 4B). The untreated lesional BALF samples contained 3,215+/−275 pg/ml CXCL8, while the immunoaffmity-absorbed BALF contained 24+/−17 pg/ml CXCL8. In this series of experiments the neutrophil response to the CXCL8-depleted BALF samples was 65.4+/−4% of their responses to the unabsorbed samples. It is known that CXCL8 can contribute as little as 15% of the neutrophil chemotactic activities in pneumonic mannheimiosis BALF obtained from an array of clinical cases (Caswell et al., 2001). Whereas the CXCL8 depletion treatments were 99% effective in removing CXCL8, there remained in these samples substantial amounts of neutrophil chemotactic activities, and the addition of 1 ng/ml CXCL8 (3-73) K11R/G31P fully abrogated their cumulative effects (FIG. 4B). This data unequivocally confirmed that CXCL8 (3-73) K11R/G31P also antagonizes the spectrum of non-IL-8 chemoattractants expressed in these samples.
[0043] CXCL8 (3-73) K11R/G31P is highly efficacious in blocking endotoxin-induced neutrophilic inflammation in vivo. In our last experiments, we assessed the ability of CXCL8 (3-73) K11R/G31P to block endotoxin-induced inflammatory responses in the skin of cattle, as well as the time-frames over which it was effective. The animals were challenged intradermally with 1 μg bacterial endotoxin 15 h before (internal positive control response), or at three different times after, intravenous, subcutaneous or intramuscular injection of CXCL8 (3-73) K11R/G31P (75 μg/kg). Thus, punch biopsies of 15 h endotoxin reaction sites were taken 15 min before treatment and at 16, 48 and 72 h after injection of the antagonist into each animal, and the numbers of infiltrating neutrophils were determined in a blinded fashion for the papillary (superficial), intermediate and reticular dermis of each biopsy. Prior to the antagonist treatments, strong neutrophilic inflammatory responses were evident at the endotoxin challenge sites in each animal (FIG. 5). Within the biopsies, the responses in the papillary dermis were mild in all animals (data not shown) and became progressively more marked with increasing skin depth, such that maximal inflammation (neutrophil infiltration) was observed around the blood vessels in the reticular dermis (FIG. 5A). Following the CXCL8 (3-73) K11R/G31P treatments, the inflammatory responses observed within the 16 h biopsies were 88-93% suppressed, while those in the 48 h biopsies were 57% (intravenous) to 97% (intradermal) suppressed, relative to their respective pretreatment responses. By 72 h post-treatment the effects of the intravenously administered antagonist had worn off, while the endotoxin responses in the intradermally and subcutaneously treated cattle were still 60% suppressed. This data clearly indicates that CXCL8 (3-73) K11R/G31P is a highly effective antagonist of endotoxin-induced inflammatory responses in vivo, that these effects can last for 2-3 days, and that the route of delivery markedly affects the pharmacokinetics of this novel antagonist.
[0044] We have found that G31 antagonizes also the chemotactic effects of the human ELR-CXC chemokines CXCL8/IL-8 and CXCL5/ENA-78 on human neutrophils. Thus, the chemotactic activities of 0.1 to 500 ng/ml of either CXCL8 (FIG. 6, left panel) or CXCL5/ENA-78 (FIG. 6, right panel) were essentially completely blocked by the addition of 10 ng/ml of our antagonist to the chemotaxis assays. Similarly, G31P blocked the chemotactic effects of CXCL8 for CXCR1/CXCR2-positive eosinophils. We and others have found that eosinophils from atopic or asthmatic subjects express both ELR-CXC chemokine receptors, and are responsive to CXCL8 (FIG. 7, left panel). The chemotactic effects of 100 ng/ml CXCL8, but not the CCR3 ligand CCL11/eotaxin, on purified peripheral blood eosinophils of an mildly atopic, non-asthmatic donor (‰99% purity) were completely abrogated by the addition of 10 ng/ml G31P to the chemotaxis assays (FIG. 7, middle panel). When tested against purified eosinophils from a hypereosinophilic patient (FIG. 7, right panel), G31P was neutralized the responses of these cells to either CXCL8/IL-8 or CXCL5/ENA-78.
[0045] This data clearly indicates that bovine G31P is an effective antagonist of the bovine ELR-CXC chemokines expressed in vivo in response to endotoxin challenge, but also can fully antagonize neutrophil and eosinophil ELR-CXC chemokine receptor responses to CXCL8 and CXCL5, know ligands for both the CXCR1 and CXCR2.
TABLE 1 PCR primers employed for the generation of each CXCL8 analogue. CXCL8 (3-73) K11R upstream primer downstream primer ANALOGUE (5′-3′ orientation) (5′-3′ orientation) T12S/H13F CA GAA CTT CGA TGC G AA AGG TGT GGA CAG TGC ATA AGA TCA AAA TGA TCT TAT GCA TTT TCC ACA CCT TTC CTG GCA TCG AAG TTC C TG G31P GAG AGT TAT TGA GAG GAT TTC TGA ATT TTC TCC GCC ACA CTG TGA ACA GTG TGG CGG ACT AAA TTC AGA AAT C CTC AAT AAC TCT C P32G GAG AGT TAT TGA GAG GAT TTC TGA ATT TTC TGG GGG ACA CTG TGA ACA GTG TCC CCC ACT AAA TTC AGA AAT C CTC AAT AAC TCT C G31P/P32G GAG AGT TAT TGA GAG GAT TTC TGA ATT TTC TCC GGG ACA CTG TGA CAC GTG TCC CGG ACT AAA TTC AGA AAT C CTC AAT AAC TCT C
[0046] Discussion
[0047] We demonstrated herein that CXCL8 (3-73) K11R/G31P is a high affinity antagonist of multiple ELR-CXC chemokines. In vitro, this antagonist effectively blocked all of the neutrophil chemotactic activities expressed in mild to intense inflammatory lesions within two mucosal compartments (lungs, mammary glands), and up to 97% blocked endotoxin-induced inflammatory responses in vivo. We identified CXCL8 as a major chemoattractant in the pneumonia and mastitis samples, but also demonstrated that 35% of the activity in the bacterial pneumonia samples was due to non-CXCL8 chemoattractants that were also effectively antagonized by CXCL8 (3-73) K11R/G31P. Based on studies of inflammatory responses in rodents (Tateda et al., 2001; Tsai et al., 2000), cattle (Caswell et al., 1997), and humans (Villard et al., 1995), it is clear that these samples could contain numerous ELR + CXC chemokines (e.g., CXCL5, and CXCL8) to which CXCL8 (3-73) K11R/G31P has an antagonistic effect.
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1
8
1
72
PRT
Bos taurus
1
Thr Glu Leu Arg Cys Gln Cys Ile Arg Thr His Ser Thr Pro Phe His
1 5 10 15
Pro Lys Phe Ile Lys Glu Leu Arg Val Ile Glu Ser Pro Pro His Cys
20 25 30
Glu Asn Ser Glu Ile Ile Val Lys Leu Thr Asn Gly Asn Glu Val Cys
35 40 45
Leu Asn Pro Lys Glu Lys Trp Val Gln Lys Val Val Gln Val Phe Val
50 55 60
Lys Arg Ala Glu Lys Gln Asp Pro
65 70
2
74
PRT
Bos taurus
2
Met Ser Thr Glu Leu Arg Cys Gln Cys Ile Lys Thr His Ser Thr Pro
1 5 10 15
Phe His Pro Lys Phe Ile Lys Glu Leu Arg Val Ile Glu Ser Gly Pro
20 25 30
His Cys Glu Asn Ser Glu Ile Ile Val Lys Leu Thr Asn Gly Asn Glu
35 40 45
Val Cys Leu Asn Pro Lys Glu Lys Trp Val Gln Lys Val Val Gln Val
50 55 60
Phe Val Lys Arg Ala Glu Lys Gln Asp Pro
65 70
3
222
DNA
Bos taurus
CDS
(1)..(222)
3
atg agt aca gaa ctt cga tgc caa tgc ata aaa aca cat tcc aca cct 48
Met Ser Thr Glu Leu Arg Cys Gln Cys Ile Lys Thr His Ser Thr Pro
1 5 10 15
ttc cac ccc aaa ttt atc aaa gaa ttg aga gtt att gag agt ggg cca 96
Phe His Pro Lys Phe Ile Lys Glu Leu Arg Val Ile Glu Ser Gly Pro
20 25 30
cac tgt gaa aat tca gaa atc att gtt aag ctt acc aat gga aac gag 144
His Cys Glu Asn Ser Glu Ile Ile Val Lys Leu Thr Asn Gly Asn Glu
35 40 45
gtc tgc tta aac ccc aag gaa aag tgg gtg cag aag gtt gtg cag gta 192
Val Cys Leu Asn Pro Lys Glu Lys Trp Val Gln Lys Val Val Gln Val
50 55 60
ttt gtg aag aga gct gag aag caa gat cca 222
Phe Val Lys Arg Ala Glu Lys Gln Asp Pro
65 70
4
216
DNA
Bos taurus
CDS
(1)..(216)
4
aca gaa ctt cga tgc caa tgc ata aga aca cat tcc aca cct ttc cac 48
Thr Glu Leu Arg Cys Gln Cys Ile Arg Thr His Ser Thr Pro Phe His
1 5 10 15
ccc aaa ttt atc aaa gaa ttg aga gtt att gag agt ccg cca cac tgt 96
Pro Lys Phe Ile Lys Glu Leu Arg Val Ile Glu Ser Pro Pro His Cys
20 25 30
gaa aat tca gaa atc att gtt aag ctt acc aat gga aac gag gtc tgc 144
Glu Asn Ser Glu Ile Ile Val Lys Leu Thr Asn Gly Asn Glu Val Cys
35 40 45
tta aac ccc aag gaa aag tgg gtg cag aag gtt gtg cag gta ttt gtg 192
Leu Asn Pro Lys Glu Lys Trp Val Gln Lys Val Val Gln Val Phe Val
50 55 60
aag aga gct gag aag caa gat cca 216
Lys Arg Ala Glu Lys Gln Asp Pro
65 70
5
45
DNA
Artificial Sequence
upstream primer
5
cagaacttcg atgccagtgc ataagatcat tttccacacc tttcc 45
6
43
DNA
Artificial Sequence
upstream primer
6
gagagttatt gagagtccgc cacactgtga aaattcagaa atc 43
7
43
DNA
Artificial Sequence
upstream primer
7
gagagttatt gagagtgggg gacactgtga aaattcagaa atc 43
8
43
DNA
Artificial Sequence
upstream primer
8
gagagttatt gagagtccgg gacactgtga aaattcagaa atc 43
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The present invention provides novel nucleic acids, novel polypeptide sequences encoded by these nucleic acids, methods for production thereof, and uses thereof, for a novel ELR-CXC chemokine receptor antagonist.
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BACKGROUND OF THE INVENTION
1. The Field of the Invention
This invention relates to a method and apparatus for severing a sheet of refractory material and, more particularly, to sever the bulb edges of a sheet cut from a continuous glass ribbon.
2. Discussions of the Technical Difficulty
As taught in U.S. Pat. No. 3,998,616 in the manufacture of glass ribbon by the float method, a continuous ribbon of molten glass is controllably cooled as it moves through a forming chamber on a pool of molten metal. The edges of the molten glass are engaged by attenuating machines as the glass cools. The attenuating machines move the edges relative to one another to provide a dimensionally stable glass ribbon having a thickness other than equilibrium thickness. After sequentially exiting the forming chamber and annealing lehr, the glass ribbon is cut into sections normally called "lehr ends" or "caps". Since the outside edges of the lehr ends are deformed by earlier contact with the attenuating machines, the outermost portion known as "bulb edges" are not usable and must be removed.
It is known that the bulb edges to be removed can be scored at a scoring station where a score is imposed on the upper surface of the glass sheet adjacent to each of the bulb edges. Thereafter the prescored lehr end is momentarily halted at an edge snap roll in which a rigid member positioned above and along the bulb edge moves downward to snap the bulb edge from the lehr end. The glass sheet is supported by the conveyor.
In U.S. Pat. No. 3,303,980 an edge snapping device is disclosed in which an anvil is engaged with one surface (lower) of the glass sheet and a striker is engageable with the opposite (upper) surface of the sheet to provide an edge snap.
U.S. Pat. No. 3,779,437 discloses an edge cutting device which includes at least two cutter means and a breaking means.
U.S. Pat. No. 4,049,167 discloses a process for removing edge portions from a glass sheet in which a previously applied score line is hammered on the opposite side of the score and a bending force is applied to the sheet to initiate breakage.
In U.S. Pat. No. 4,285,451 a method and an apparatus for severing edges of a glass sheet is disclosed in which the surface of a resilient member lying in a plane subtending an oblique angle with the sheet is moved downward against the bulb edge to sequentially sever the bulb edge at a first and second score line previously applied.
U.S. Pat. No. 3,268,135 discloses a method and apparatus for snapping sheets of glass by applying a curvature on the sheet.
U.S. Pat. Nos. 4,109,841 and 4,136,807 disclose a method and apparatus for opening score lines in glass sheets by snapping the score with a bending moment applied to the glass sheet along a path transverse to the article movement path.
One of the problems associated with snapping the bulb edge portions along a score line is that the edge produced has defects, including serration hackle, chips, deep sharks teeth, flare and bevel, especially in glass sheets having a thickness greater than 5 mm. Although many automated bulb edge snapping machines do work well enough with thinner glass, the best edges on thicker glass sheets are obtained by hand cutting in which a score line is "run" to open the score by applying a bending moment to one end of the score line. Unfortunately, the use of hand cutting techniques on the main line of an automated float plant to sever bulb edges is not feasible. Accordingly, an apparatus is needed that will provide a good clean edge on lehr ends even on thicknesses of glass above 5 mm. The resultant edge should be of the quality of hand cutting techniques and yet be fully automated and capable of high speed operation with a quick recycling time. The instant invention is directed toward those needs.
SUMMARY OF THE INVENTION
This invention relates to a method and apparatus of severing a refractory material having a pair of opposed surfaces, for example, lehr ends having bulb edges. The apparatus provides for twisting the trailing edge about previously applied score lines by the use of a pair of mandrels. A lower mandrel placed beneath the sheet raises the edge of the sheet in contact with the trailing edge. The contact is made at a slight angle, thus engaging the bottom corner of the trailing edge of the lehr end. The edge being thus slightly raised whereupon an upper mandrel moving in a arcuate path having a downward vertical component as well as a horizontal edgewise component contacts the glass at the upper corner of the trailing end. The peeling or twisting movement of the mandrels "peels"or "runs" the score to open the score, thus severing the bulb edge from the lehr end.
In order to improve upon the quality of the severed edge, it has been found desirable to repeat the bulb edge removal sequence along a second score line parallel and inbound of the first score. The mandrels in the same relative position are moved toward the glass sheet so that the lower mandrel is placed under the second score. The second glass strip is then removed in the same manner as the initial bulb edge. This second cut or "money" cut, is of a finer quality since the main stresses in the bulb edges of the lehr end incurred in the attenuating process relax upon severing the bulb edge. The second edge removal, accordingly, is then made in an area of the glass having less stress, so the resultant edge has very few defects. By "running" the score to open and sever the glass instead of "snapping" the score, the resultant second edge is of a very fine or mirror quality.
In order to provide such a fine edge in a lehr end which is advancing along a main line of a modern float glass plant, it is necessary that the bulb edge severing apparatus be easily moved into position, adjusted and maintained without stopping the flow of glass sheets. Accordingly, a pair of apparatus of the instant invention are attached to frame members on either side of the advancing glass sheets. The apparatus are mounted so as to each be slideably and selectively movable along a pair of rails to advance toward or retreat from the glass sheets as required. An air cylinder controls the positioning of the apparatus along the rails. A separate air cylinder provides the opening movement of both upper and lower mandrels through the use of mechanical linkage.
Since the peeling or running motion was modeled after hand cutting practices used on thicker glass, it is necessary to provide a double peeling action. The two mandrels which twist about the score line are thus tilted slightly away from the horizontal plane of the major glass surfaces in that the upper mandrel is tilted slightly upward and the lower mandrel is tilted slightly downward. Thus, when the two mandrels engage the glass it is only at the trailing end corners of the sheet that the glass is contacted. The torque induced by the movement of the mandrels propagates the previously applied score and opens the score in a manner similar to that employed by hand cutting in which pliers or manual opening methods are employed.
The use of the dual mandrels in the apparatus necessitates the use of an actuating mechanism such as a power cylinder. Although two or more power cylinders could be employed, the invention does provide that the actuation can be accomplished by a single power cylinder and that the movement of the mandrels is accomplished by the use of a mechanical linkage having a variety of adjustments.
It has been found that the raising of the lower mandrel in an arcuate path does not produce as fine a cut edge as if the mandrel were raised substantially normal to the major glass plane, thus the mechanical linkage of the invention is further enhanced by a pantograph type of parallelogram linkage which compensates for the arcuate movement of the lower mandrel to alter the movement of the lower mandrel to that of a vertical one. Since glass to metal contact does not provide sufficient friction between the materials and induces uncontrolled stresses which damage the glass edges, both mandrels are covered with a slightly resilient, high friction coefficient material such as rubber.
In an automated wareroom, the cutters and conveyors are computer controlled and many machines rely upon air power cylinders in such plants. The use of air cylinders in the instant invention further enhances the adaptability of the invention to the computer controlled wareroom environment in that the apparatus is easily computer controlled and attached to existing air power supplies.
It has been found in hand cutting and in the opening of scores in glass material in general that a better edge can be obtained by running or opening the score from a direction opposite to the direction the score was induced in the glass. Accordingly, the apparatus of the instant invention is installed so that it contacts the trailing edge of the advancing lehr ends rather than their leading end. The scores are imposed by use of a fixed cutting bridge in which the scores are necessarily imposed upon the lehr ends from the leading end toward the trailing end. It has been found that by the use of one or more additionaly scoring wheels attached to the apparatus upstream from the mandrels of the instant invention that score lines may be imposed separately from the normal scoring bridges.
In summary, the apparatus of the instant invention is directed to the automated removal of bulb edges of glass sheets, particularly lehr ends, so as to produce a fine cut edge without chips, sprawls, hackle, flare or bevel, by the use of a pair of simultaneously moving mandrels imposing a torque on the trailing end of a previously applied score line. The method of using the apparatus for severing the edges of a glass sheet include the steps of scoring a line substantially parallel to the bulb edge to be removed, and applying a torque to the trailing end in order to open and run the cut to sever the sheet. Additional steps of providing a second score inboard and parallel to the first score and applying a torque to the trailing end about the second score are also contemplated within the scope of the invention.
In order that the invention may be more clearly understood, there are the preferred embodiments of the invention which will now be described in reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a single station for removing the bulb edge on a glass sheet advancing along a conveyor showing the mandrels in position about a previously applied score line in accordance with the teachings of the invention.
FIG. 2 is a fragmented front elevational view of the parallelogram linkage of the bottom mandrel with portions removed for purposes of clarity.
FIG. 3 is a front elevational view of the apparatus showing a fragmented trailing end view of a lehr end having an unsevered bulb edge.
FIG. 4 is a fragmented end elevational view of the trailing edge of a lehr end in which the torque applying mandrels are shown in position relative to the lehr end bulb edge, a conveyor roll, and each other.
FIG. 5 is a fragmented side elevational view similar to FIG. 4 in which the relative movement of the mandrels during the torque applying steps are depicted.
FIG. 6 is a fragmented side elevational view similar to FIG. 4 depicting the relative position of the torque applying mandrels in severing the second strip from the lehr end.
FIG. 7 is a fragmented side elevational view similar to FIG. 5 in which the relative movement of the mandrels is depicted while severing the second strip from the lehr end.
FIG. 8 is a fragmented side elevational view in which the mandrels are depicted tilted at a greatly exaggerated angle to show that the mandrels contact the upper and lower edges of the trailing end of the glass sheet wherein the lehr end glass sheet is viewed from a position substantially normal to the position of the lehr end depicted in FIGS. 1, 2, 3 and 4. Portions of the apparatus are removed for clarity.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The apparatus 10 is shown generally in FIG. 1 attached to a horizontal conveyor 13. The horizontal conveyor 13 is of the type generally known in the art as having a frame 14, and powered conveyor rolls 16 which are attached to conveyor roll axles 17. Conveyor roll axles 17 are mechanically driven and computer controlled so that horizontal sheets placed upon the array of rolls attached at intervals on the axles 17 provide for the movement and stoppage of articles along the conveyor 13. As can be seen from FIG. 1, large sheets of glass 15 are depicted being conveyed from left to right. The sheets of glass had previously been severed from a ribbon of glass emerging from the cold end of an annealing lehr (not shown). These large sheets of glass 15, also known as lehr ends, or caps, are as wide as the ribbon width. The width of the caps therefore, are approximately 12 feet (3.66 meters) wide, however they may be larger or smaller depending upon the width of the ribbon emerging from the cold end of the annealing lehr. The lehr ends also may be of differing lengths, however, they are generally longer than they are wide. Lateral scoring or cross-scoring equipment (not shown) imposes a lateral or cross-score in the ribbon which is then opened to sever the ribbon into the lehr ends 15. An example of the cross-cutting (lateral scoring) and subsequent opening is taught in general in U.S. Pat. No. 4,285,451 which teachings are hereby incorporated by reference.
With reference to FIG. 1, it can be seen that the direction of travel of the lehr ends are from left to right. As the lehr ends are so transvering the conveyor, one or more scores are imposed in the lehr end along the lateral edge. These scores may also be imposed prior to sectioning of the ribbon into lehr ends. A first score 21 and a second score 22 are depicted in FIG. 1 on a lehr end 15. Scoring techniques and apparatus that may be used in the practice of the invention, but not limiting thereto, are taught in U.S. Pat. Nos. 3,244,337; 3,800,991; 3,865,293; 3,865,294 and 4,057,184 which teachings are hereby incorporated by reference.
As the purpose of the instant invention is to remove the bulb edge and provide a clean, pristine edge on the lateral sides of the lehr end 15, the invention must provide for removal of the bulb edge 20 and cut edge section 26 (if a double cut is made). Thus, the apparatus 10 is attached to conveyor frame 14 on the lateral side of the conveyor. While only one apparatus 10 is depicted in FIG. 1, operating on the left side of the conveyor as facing the direction of glass movement, an additional apparatus 10 may be placed on the opposite side of the conveyor 14 thus providing for near simultaneous removal of the bulb edge 20 and cut edge strip 21 on both lateral sides of the lehr end 15.
Conveyor 13 as is generally known, is of a type which may be stopped and started as necessary to convey the glass to a predetermined position. At times the glass movement is stopped so that operations may be performed upon the glass or that it is in a holding position awaiting further cutting or handling downstream. As the conveyor drive is controlled by an information processing unit (computer) programmed to stop and start the conveyor, the lehr ends 15 may be positioned with the trailing end 27 of lehr end 15 within a certain tolerance range next to apparatus 10. It has been found that without modification, present conveyors will stop the trailing end at a point within ±5 inches (12.7 cm) regardless of the size of lehr end 15.
It can be seen by reference to FIG. 1 that when the bulb edge is removed by apparatus 10, the bulb edge falling by its own weight will land in a receptacle or cullet chute 18 to be returned to the melting furnace or disposed of in a conventional manner.
With reference to FIG. 3, the right side elevational view of the apparatus 10 is depicted as if looking at apparatus 10 while facing in the direction of glass flow. The apparatus 10 is generally provided with a pair of mandrels 31 and 32 which twist about trailing end 27 of lehr end 15 in the vicinity of bulb edge score 21 to open score 21 by running the score from the trailing edge 27 of lehr end 15. Upper mandrel 31 is a cylinder lying generally in the plane of the major surfaces of lehr end 15, but having a slight incline to the plane of lehr end 15 in that the upper mandrel 31 is positioned slightly lower toward trailing edge 27 of lehr end 15 and slightly higher as it proceeds along a longitudinal axis of upper mandrel 31. The inclination of mandrel 31 from being parallel to the plane of lehr end 15 is depicted in greatly exaggerated form in FIG. 8.
Lower mandrel 32 as depicted in FIG. 3 is of a similar construction to upper mandrel 31; however, it has been found that the best results are obtained if lower mandrel 32 is of a slightly larger diameter than upper mandrel 31. This preferred size relationship is depicted in FIG. 3. Nevertheless, it should be understood that lower mandrel 32 could be of a smaller diameter than upper mandrel 31 as depicted in FIGS. 4, 5, 6, 7 and 8 and satisfactory results would be obtained and still not depart from the teachings of this invention.
Lower mandrel 32 is also slightly inclined to the major plane of lehr end 15 with the most rearward portion of the longitudinal axis of lower mandrel 32 slightly raised with respect to the position of the most foreward part of the longitudinal axis of lower mandrel 32 as depicted in greatly exaggerated form in FIG. 8. The angle of upward slope 49 for upper mandrel 31 and the angle of downward slope 50 of mandrel 32 as shown in FIG. 8, has been found to yield satisfactory results when both angles 49 and 50 are in the vicinity of 1° from horizontal. It is to be understood that other angles of incidence 49 and 50 could be used without departing from the scope of the invention.
Returning now to FIG. 3, where it can be seen that one end of cylindrical, upper mandrel 31 is attached to slidable member 38 and upper elongated rod 35 which is, in turn, pivotally attached to frame member 12 at horizontal frame wall 58 by use of blocks 65 and journal 55. As elongated arm 35 moves about journal 55, upper mandrel 31 moves in an arcuate path and approaches the major plane of lehr end 15 in a downward an outward motion. Whan mandrel 31 is rotated from the raised position to the lowered position about journal 55, upper mandrel 31 moves down toward lower mandrel 32 and also outward toward bulb edge 20. Thus, as shown in FIG. 8, when in contact with lehr end 15 at trailing end 27 at upper edge corner 60 the movement of upper mandrel 31 acts to push down upon bulb edge 20 also urging bulb edge 20 from lehr end 15, thus opening score 21 to sever bulb edge 20 from lehr end 15.
In order to actuate upper elongated rod 35, longitudinal turnbuckle 62 is provided to attach elongated rod 35 between pivotal point 52 and pivotal point 53 located on elongated rod 46. Elongated rod 46 is pivotally attached at block 65 by use of journal 54. The leftmost end of lower elongated rod 46 is attached to actuating cylinder 39 at pivotal point 52. Actuating cylinder 39 is attached also at pivotal point 51 by use of blocks 65 attached to frame 12. Thus, it can be seen from FIG. 3 that when actuating cylinder 39 is extended, pivoting journal 52 is moved downward in turn pivoting about journal 54, hence the rearward portion of elongated member 46 is urged upward along elongated rod 35 in a downward arcing movement by use of turnbuckle 62. It can be further seen that by shortening the length of turnbuckle 62 or by increasing the length of turnbuckle 62, the position of upper mandrel 31 can be raised or lowered. Elongated rod 36 having rear portion 59 and forward portion 46 pivots about journal 54. When power cylinder 39 is actuated, journal 52 is lowered, thus pivoting elongated rod 36 about journal 54 and block 65 attached to frame 12, in turn causing pivotal end 64 of elongated rod 36 to rise. The movement of pivotal point 64 is an arcuate path about journal 54. If lower mandrel 32 were directly attached to elongated rod 36, lower mandrel 32 would move in an arc toward upper mandrel 31 thus pinching glass 15 therebetween. Since the pinching of the glass would not provide for proper score opening, additional linkage is provided to cause lower mandrel 32 to not move in an arcuate path, but rather to move in an upward direction substantially normal to the major plane of lehr end 15. In order to provide for the best opening of score line 21 or 22, it has also been found that lower mandrel 32 must contact the corner 61 of lower surface 24 and trailing end 27 at a point directly beneath the score line. While lehr end 15 is raised as depicted in FIGS. 5 and 7, lower mandrel 32 will continue to contact the glass directly beneath the score line if the movement of lower mandrel 32 is substantially upward and not arcuate.
To avoid pinching and to place lower mandrel 32 directly under the score, an additional linkage is provided by vertical link 47 pivotally attached to journal point 64. By attaching vertical link 47 to pantograph lower arm 45 which is in turn pivotally attached to frame 12 by use of journal 56 and blocks 65 provides that as pivotal point 64 of arm 46 moves in an arcuate upward path, journal point 63 is rotated about journal point 64 in an equal and opposite manner. Lower mandrel 32 which is attached to vertical member 47 at lower mandrel attachment point 38 slightly above pivot point 64 as shown in FIG. 2, causes the lower mandrel 32 to rise substantially upward and normal to glass plane 15. The movement of mandrel 31 and 32 thus are not together in a pinching manner, but rather contact the glass in a peeling twisting manner to open score 21 and provide separation of bulb edge 20 from lehr end 15.
Referring now to FIG. 3, it can be seen now that actuating cylinder 39, upper elongated arm 35, lower elongated arm 36, block 65, pantograph arms 45 and 47, and the associated mandrels 31 and 32 are all attached to frame 12. Frame 12 is a box structure having an exterior wall, interior vertical wall 57 and interior horizontal wall 58. Frame member 12 is slidably attached along rods 41 and 42 which are in turn attached by use of brackets 43 to main frame 11. It can thus be seen that frame 12 can be slid along rods 41 and 42 from side to side as shown in FIG. 3, thus in turn positioning mandrels 31 and 32 from right to left about lehr end 15. In order to accomplish the sliding of frame 12 and associated mechanical linkages, power cylinder 40 is provided. Power cylinder 40 is attached between main frame 11 and slidable frame 12.
It has been found that power cylinder 40 can be attached to the forward portion of frame 12 and the arrangement allows for an additional power cylinder to be attached in line so that two cylinders in tandem allow greater control in the computerized operation of apparatus 10 by having the cylinders operate independently as well as in conjunction with one another. Power cylinders 39 and 40 are of the air cylinder type; however, hydraulic power cylinders, electric ball screw actuators, electric motors or other power cylinders may be employed without departure from the teaching of the invention.
It can be seen from FIG. 3 that once the bulb edge 20 has been removed by the twisting action of mandrels 31 and 32 about score 21 that by sliding frame 12 toward score line 22 that the second edge strip 26 may be removed in a like manner. The positioning of lower mandrel 32 relative to score lines 21 and 22 can be accomplished by the use of actuating cylinder 40 or may be accomplished by screw type adjustment means 44 which advances power cylinder 40 and frame 12 and is attached between power cylinder 40 and frame 11.
Upper breaker arm 35 is further provided with a fine adjustment 37 which allows for adjusting the position of upper mandrel 31 relative to lower mandrel 32. This adjustment effectively lengthens or shortens breaker rod 35 to obtain the proper contact on the glass. Upper mandrel 31 and lower mandrel 32 are bolted to slidable member 38 and vertical pantograph link 47 respectively. Vertical link 47 could also be provided with an adjustment slot (not shown) which would allow a fine adjustment of the movement of lower mandrel 32 to insure that lower mandrel is urged upward substantially normal to the lehr end 15 when power cylinder 39 is atcuated.
Upper mandrels 31 and lower mandrels 32 do not pivot or revolve about their attachment points. Furthermore, upper mandrel 31 and lower mandrel 32 are provided with a nonslip coating or sleeve 33 and 34, respectively, as shown in FIGS. 4, 5, 6 and 7. Coating 33 and 34 could be of rubber, nylon, or other appropriate surface which provides the necessary friction and yet avoids metal to glass contact. It has been found that if the uppermost contact point of lower mandrel 32 becomes worn so that a flat spot or abrasion develops on coating 34 that the mandrel 32 may be loosened and slightly rotated and when retightened so as to provide a curved glass to mandrel contact surface. In a like manner, upper mandrel 31 is loosened, rotated and retightened to provide a single tangential contact point.
The operation of the invention will now be described in reference to FIGS. 4, 5, 6 and 7. In FIG. 4, it can be seen that lehr end 15 having score lines 21 and 22 and the upper surface 23 is conveyed along a series of rolls 16. When rolls 16 are halted, lehr end 15 is placed in a position so that trailing edge 27 of lehr end 15 is somewhere between the contact surfaces 33 and 34 of upper mandrel 31 and 32, respectively. This can best be seen by reference to FIG. 8. The apparatus 10 will remove the bulb edge 20 unless trailing end 27 stops beyond the lengths of upper mandrel 31 and lower mandrel 32.
Once the lehr end 15 is in position as shown in FIGS. 4 and 8, power cylinder 40 is actuated to position lower mandrel 32 directly beneath score line 21. Power cylinder 39 is then actuated thus raising lower mandrel 32 in a manner previously discussed while moving upper mandrel 31 in a downward and outward direction. The glass is thus gripped on the corner edge of the trailing end 27 in a twisting relationship. In FIG. 5, it can be seen that lower mandrel 32 actually raises the lower surface of the glass 24 off roll 16 by an amount approximating 1/2 inch (1.27 cm). The distance 19 that the lower surface 24 is raised off roll 16 is shown in FIGS. 5 and 7.
As the lower mandrel 32 rises substantially vertically and normal to the major plane of the glass 15, upper mandrel 31 is moved in an arcuate path downward and outward toward bulb edge 20. When contact is made as shown in FIG. 5, score line 21 is opened from the trailing end 27 of the glass to the leading end of the glass, thus providing a clean lateral edge 29. By so removing bulb edge 20, imperfections 25 caused by the ribbon forming process as well as edge stresses produced in the formation of the glass are removed. While it is not necessary to make additional scores or remove additional portions of the edge, it has been found that once such stresses and imperfections have been removed by removing the first bulb edge, a second previously applied score may be opened which provides an even finer finished edge. Such a result is taught in U.S. Pat. No. 4,285,451, however the instant invention allows for opening the second score without having scores of differeing pressures or depths. Apparatus 10 provides a moving frame 12 to allow for a second edge portion to be removed.
With reference to FIG. 6, it can be seen that after bulb edge 20 has been removed, lower mandrel 32 is advanced toward conveyor roll 16 and positioned directly under score line 22. The positioning of the lower mandrel 32 is accomplished by extending power cylinder 40 in a lateral manner. Once lower mandrel 32 is positioned under score 22, power cylinder 39 is actuated thus raising the lower mandrel 32 by gap distance 19 off roll 16 as shown in FIG. 7 and upper mandrel 31 is moved in a downwardly and outwardly direction, thus opening and severing edge portion 26 from lehr end 15 and providing pristine edge 30. As in previous bulb edge removal, power cylinder 39 is de-energized and returns lower mandrel 32 below the upper plan surface of roll 16 as well as returning mandrel 31 above the upper surface 23 of lehr end 15 thus allowing lehr end 15 to lie along horizontal conveyor 13 and be conveyed to additional cutting and/or packaging or storing operations.
While it is contemplated that the invention is best utilized with glass thicknesses of 5 mm and thicker, it is understood that apparatus 10 will provide the satisfactory edge in thinner glass sheets; however, with thin glass sheets, ordinary snapping means have been found to provide greater speed of bulb edge removal. In making thicker glass by the float process, the glass ribbon moves at a slower rate, as the thickness of the glass increases. Thus, the manufacture of thicker glass allows more time for the operation of bulb edge removal. The preferred embodiment, while providing pristine edges on lehr ends requires an operating recycling time of approximately 4 to 5 seconds to make the two severing cycles. By using different component parts, it is contemplated that this recycling time may be varied. While score lines 21 and 22 have been described as having been previously placed upon lehr end 15 at a conventional cutting bridge, it is also within the scope of the invention to provide one or more cutting heads attached to frame 12 upstream of the invention to provide for scoring near the site of the apparatus 10. When such remote scoring heads are utilized, they can thus be positioned by use of actuating cylinder 40 if they are attached to frame 12.
When the invention is not in use, such as when bulb edges are removed by conventional snapping on thin glass sheets, as previously discussed, it can readily be seen that by retracting power cylinder 40, inner frame 21 and the associated mechanism can be removed from the vicinity of the bulb edge thus making apparatus 10 inobtrusive. Additionally, apparatus 10, by being capable of being removed from the main line conveyor without disturbing the flow of glass allows for ease in maintenance and flexibility of control.
As can now be appreciated from the foregoing description of the preferred embodiments, the invention is not limited to the above example which was presented for illustration purposes only. It is understood that other steps, examples, components and method of operation will occur to those skilled in the art from a thorough reading of this disclosure without departing from the scope of the invention as claimed hereafter.
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Bulb edges are severed from a glass sheet. At least one score is imposed along and adjacent to the bulb edge, and the scores are sequentially opened by mechanically running the score. A pair of powered and jointly actuated, simultaneously moving cylindrical mandrels apply torque about the trailing end of the score line to sever the sheet. The lower mandrel moves in an upward direction beneath the sheet while the upper mandrel moves through an arcuate path down and toward the bulb edge. A method of severing bulb edges from a glass sheet is also disclosed in which the scores are opened by applying torque about the score line on the upper and lower edges of the trailing end of a glass sheet.
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BACKGROUND OF THE INVENTION
There are many applications, particularly in mining and in industry, in which continuous conveyor belts are utilized to move bulk materials such as coal, grain, and the like from one location to another. In any system of this kind, the bulk material must be deposited on the moving conveyor belt; interruption of belt movement to receive a new load is economically infeasible. At the discharge end, it is usually necessary to scrape or clean the belt to make sure that all of the bulk material is left at the desired new location. Both ends of such a continuous belt conveyor system presents substantial problems; this invention is concerned with the problems and difficulties that occur in depositing bulk material on the moving belt for transport to a distant location.
A major problem of the input station of any continuous conveyor belt system is leakage of the bulk material being transported by the system. Broadly speaking, this has been met to a substantial extent by resilient aprons affixed to rigid skirtboards around the input station. Examples previously known resilient skirtboard aprons and apron mounts are disclosed in Gordon U.S. Pat. Nos. 4,231,471, 4,436,446, 4,877,125, and 4,989,727. Perhaps the best such skirtboard apron is the simple but effective device described and claimed in Gordon U.S. Pat. No. 4,989,727 and sold commercially under the designation ATLASTASEAL. Even that skirtboard apron, however, may have leakage problems, particularly as the result of appreciable movement of the conveyor belt, vertically or laterally, other than in the conveying direction through the input station.
It has been conventional, in the input stations for continuous belt conveyor systems, to support the conveyor belt in a generally open upwardly-facing U-shaped configuration at the input station, usually on three separate series of idler or support rollers. This input station configuration has one set of horizontally oriented support rollers extending longitudinally of the center of the belt. On each side there is another set of support rollers projecting upwardly at an acute angle and supporting a side portion of the belt.
Inevitably, there is some sagging of the belt between each set of support rollers. This leads to leakage problems at the input station. In part, this kind of leakage has been reduced by modifying the input station of the conveyor belt system to afford a plurality of elongated stationary support plates or rails under the conveyor belt. As with the rollers, the side portions of the belt are supported at an acute angle to the center portion, which is basically horizontal. However, the benefit of the resulting reduction in leakage, while desirable, is at least in part offset by increased drag on the conveyor belt, which may produce appreciable wear on the belt and which also may increase the costs of operation for the conveyor.
SUMMARY OF THE INVENTION
It is a principal object of the present invention, therefore, to provide a new and improved input station for a continuous belt conveyor of the kind used in mines, coal preparation stations, power stations, and other industrial applications for movement of bulk materials from one location to another.
Another object of the invention is to provide a new and improved input station for a continuous belt conveyor employed to transport bulk materials from one location to another, which input station reduces leakage of the bulk material from the conveyor while at the same time avoiding undue frictional drag on the belt, so that belt life is maximized.
A specific object of the invention is to provide a new and improved replacement kit for the side rollers of a conventional input station for a continuous belt conveyor system, which kit affords improved operation as regards both leakage and drag reduction at minimum cost and with assured long operating life.
Accordingly, the invention relates to an input station for a belt conveyor comprising a continuous conveyor belt of given width having a conveyor run extending through an input station to and around a head pulley at a discharge location, and a return run from the head pulley to and around a tail pulley back into the input station. The input station comprises a frame, center belt support means having a width less than the belt width, mounted on the frame, for supporting the central portion of the conveyor belt throughout the input station; the center belt support means comprises a plurality of support rollers extending across and engaging the underside of the conveyor run of the conveyor belt throughout the input station. The input station further comprises first and second lateral belt support means, each having a width less than the belt width, mounted on opposite sides of the frame adjacent the center belt support means; each lateral belt support means includes at least one belt support rail, extending parallel to the conveyor belt, engaging the underside of the conveyor run of the conveyor belt and supporting a lateral portion of the conveyor belt, with no appreciable sag, throughout the input station, at an acute angle to the central portion of the conveyor belt. The input station also has first and second input skirtboard means, positioned above opposite sides of the conveyor belt and each extending longitudinally of the belt, for sealing off the lateral edges of the conveyor belt at the input station.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are simplified cross-sectional elevation views illustrative of prior art input stations for continuous belt conveyor systems;
FIG. 3 is a simplified schematic illustration of a continuous belt conveyor system;
FIG. 4 is a perspective view, partly in cross-section, of an input station for a belt conveyor constructed in accordance with a preferred embodiment of the present invention;
FIG. 5 is a transverse sectional elevation view of one-half of a belt conveyor input station like that of FIG. 4; and
FIG. 6 is a detail view of a preferred support rail mount used in FIGS. 4 and 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a well known construction used for the input station 20 of a belt conveyor of the kind comprising a continuous conveyor belt 21. Conveyor belt 21 is utilized in a conveyor system of the kind shown schematically in FIG. 3; belt 21 extends through input station 20 to and around a head pulley 22 that rotates in the direction indicated by arrow A. The head pulley 22 is at a discharge location 23 where the bulk material 24 carried by belt 21 is discharged as indicated by arrow C. The conveyor system usually includes one or more belt scrapers (not shown) at or near the discharge location 23, FIG. 3. From head pulley 22 belt 21 extends on a return run 25 that may include an idler 26, to and around a tail pulley 27 that rotates in the direction indicated by arrow B. Thus, the continuous belt 21 comes back to its conveyor run 28 from the input station or location 20 to the discharge location 23.
In a conventional input station for conveyor belt 21, as best shown in FIG. 1, belt 21 is supported on a set of center support rollers 31 and on two sets of side support rollers 32 and 33. Each center support roller 31 is mounted between a pair of center stanchions 34 and 35. Each side belt support roller 32 on one side of belt 21 is mounted between one of the center stanchions 34 and a side stanchion 36. The other side support roller 33 in each set is mounted between the second center stanchion 35 and a side stanchion 37. All of the stanchions 34-37 are affixed to and supported by a suitable base or frame member 38.
The conventional input station 20 of FIG. 1 further comprises skirtboard means including two rigid vertical skirtboards 42 and 43 located above the opposite sides of the input station. A resilient skirtboard apron 44 mounted on skirtboard 42 extends downwardly into engagement with the side edge portion of belt 21 on roller 32. Similarly, there is a second skirtboard apron 45 mounted on skirtboard 43 and projecting downwardly into engagement with the edge of belt 21 on roller 33. A variety of techniques have been used for mounting resilient aprons such as members 44 and 45 on skirtboards like members 42 and 43 at the input station of a belt conveyor. It will be understood that although only one set 31-33 of support rollers is shown in FIG. 1, the conventional input station 20 for a continuous conveyor belt system incorporates a substantial number of sets of center and side rollers throughout the length of the input station as generally indicated by rollers 31 in FIG. 3. It will also be understood by those skilled in the art that skirtboards 42 and 43 and aprons 44 and 45 have substantial length in the direction of movement of conveyor belt 21, also as generally indicated in FIG. 3. For FIG. 1 it is assumed that the movement of belt 21 is toward the plane of the drawing.
If the elements of input station 20 all worked perfectly, keeping belt 21 taut as indicated in FIG. 3, there would be little or no leakage problem. In real life, this does not happen. Rather, the belt 21 sags a bit between each of the support rollers 31 and each of the lateral support rollers associated with the center support rollers. As a consequence, there is often a substantial leakage problem around the bottom of each of the two aprons 44 and 45. Resolution of the leakage problem is quite difficult.
FIG. 2 illustrates another known form of input station 50 that has been used with continuous belt conveyor systems. In this instance, the base member 38 carries a plurality of support rails 51 that extend longitudinally down the center of the input station. As with FIG. 1, it is assumed that the direction of movement of conveyor belt 21 in FIG. 2 is toward the plane of the drawing. The skirtboards 42 and 43 and their aprons 44 and 45 may be the same as in the station 20 illustrated in FIGS. 1 and 3.
At the right-hand side of input station 50, FIG. 2, there is a fixed support member 52 that extends upwardly at an acute angle from frame 38. Support member 52 may nave an additional brace 53. On this side of station 50 there are two additional belt support members or rails 54 that engage the underside of belt 21 and support it. At the left-hand side of input station 50, FIG. 2, there is another angular lateral support member 55 that extends upwardly at an acute angle to base 38 and that may be supported by a further brace 56. Two additional belt support rails 57 are mounted upon member 55. Supports 52 and 55 and braces 53 and 56 are repeated several times through the length of input station 50, just like rollers 31-33 of FIGS. 1 and 2. All of the support rails 51, 54 and 57 preferably extend for the full length of the input station 50, though input station 50 can be constructed in sections if desired.
Operation of input station 50 is like that of input station 20. In each instance, bulk material 24 (see FIG. 3) is discharged into the input station between skirtboards 42 and 43 and onto belt 21. It is carried out of the input station on belt 21 toward the discharge location as illustrated at 23 in FIG. 3. In input station 50, FIG. 2, as in station 20, the material is confined by skirtboard aprons 44 and 45, which limit leakage at the edges of the belt. With respect to edge, 50 of FIG. 2 is better than station 20 of FIG. 1 because the conveyor belt 21 is flatter, as it moves through input station 50, than in station 20. Stated differently, each of the outermost belt support rails 54 and 57 of station 50, FIG. 2, affords a more consistent engagement with the associated apron 44 or 45 than is possible with the construction of input station 20, FIG. 1, where there is inevitably some sag between rolls 32 and 33 at the opposite sides of the input station. On the other hand, though input station 50 shows less leakage and may be an improvement with respect to possible impact damage, it does increase the drag on conveyor belt 21 as the belt moves through the input station. Thus, the wear on the belt is higher with the construction shown in FIG. 2 than in FIG. 1. Moreover, power requirements for the overall conveyor system may be somewhat increased.
FIGS. 4 and 5 show similar input stations 100 and 120, each constructed in accordance with the present invention. Each of these input stations combines features from the two previously known input stations, and each affords significant improvements over both known constructions. In the input station 100, FIG. 4, conveyor belt 21, moving in the direction of the arrow X, is again maintained in an open, upwardly facing U-shaped configuration. The supporting frame is the same as for station 20, FIG. 1; it includes the base members 38, the center stanchions 34 and 35, and the side stanchions 36 and 37. Four pairs of center stanchions 34 and 35 are included in the portion of input station 100, FIG. 4, along with four sets of side stanchions 36 and 37. It should be understood, however, that the overall length of input station 100 may be substantially greater than shown and that there may be more stanchions and more of the central support rollers 31, which remain unchanged from station 20 of FIG. 1.
In input station 100, FIG. 4 however, there are no side belt support rollers such as the rollers 32 and 33 of FIG. 1. Thus, at the right-hand side of input station 100, instead of side support rollers there are a plurality of fixed lateral support members 132. Each support member 132 is a length of angle iron having two mounting members 134 welded or otherwise affixed to its opposite ends. Each mounting member 134 has a configuration such that it can be fitted into the stanchions 34 and 36 as a direct replacement for a side support roller such as one of the rollers 32, FIG. 1. Of course, this mounting arrangement positions the lateral support member 132 at an acute angle to the frame or base member 38.
In the construction illustrated in FIG. 4, there are three mounting bolts 136 extending upwardly through the horizontal portion of each of the angle lateral support members 132. In the narrower input station 120 of FIG. 5, there are just two such bolts. Each bolt has an enlarged head 138, as best shown in FIGS. 5 and 6, that is positioned within an elongated C-shaped steel rail base 140. Each metal base element 140 preferably extends for the full length of the input station; see FIG. 4. There is a nut 142 on each bolt 136, as shown in FIG. 5. Each slider rail base element 140 supports a slider rail 150; FIGS. 4-6. Each slider rail 150 includes a metal pad welded to the related channel base 140. The surface portion of each slider rail or belt support 150, on the other hand, is preferably a resin composition affording low friction with respect to belt 21, because the belt support rail engages and supports the bottom surface of the conveyor belt. A preferred material for use in the belt-contacting portion of each belt support rail 150 is a urethane high molecular weight (UHMW) resin composition.
As best shown in FIG. 5, the skirtboard 42 for input station 120 may be equipped with a resilient apron 144 of the kind described and claimed in the aforementioned Gordon U.S. Pat. No. 4,989,727. This skirtboard apron, or any other skirtboard apron, is subject to substantially less wear and works considerably more efficiently with the outer belt support rail 150 than with a roller support that has the belt sagging between rollers.
As previously noted, the input station 100 of FIG. 4 has the same construction as station 120 of FIG. 5 except that it is for a wider belt. Thus, at the left-hand side of station 100, FIG. 4, there is a lateral support member 133 between each pair of stanchions 35 and 37. The support members 133 are again preferably lengths of angle iron and have mounting members 135 that enable use of each support member 133 as a direct substitute for one of the rollers 33 of station 20, FIG. 1. In station 100 there are three belt support or slider rails 151 at the left-hand side of the input station, just as there are three belt support rails 150 at the right-hand side of the station. The only difference between station 100, FIG. 4, and the construction of station 120, FIG. 5, is due to the different belt width. Skirtboard 43 may be unchanged from FIG. 1. In FIG. 4, the skirtboard apron 145 is shown with the same configuration as the apron 144 of FIG. 5. However, any desired skirtboard apron and configuration can be employed.
The mounting means for the belt support or slider rails 151 at the left-hand side of input station 100, FIG. 4, are the same as shown in FIG. 5. Again, the mounting means preferably includes a series of bolts 137, one for each belt support rail 151 on each lateral support member 133. Mounting means comprising bolts 137 come in sets, one for each rail 151 for each of the center belt support rollers 31 in the station. As illustrated in FIG. 4, station 100 has four center support rollers 31, four pairs of center stanchions 34 and 35, four sets of lateral support members 132 and four sets of lateral support members 133. Each lateral support member is mounted between a center stanchion and a side stanchion in place of one of the side support rollers of a station like that illustrated in FIG. 1. There are two sets of mounting means exemplified by the bolts 136 and 137, for mounting the belt support rails 150 and 151 on the lateral support members 132 and 133 to support the conveyor belt 21 at an acute angle, at each outside edge, relative to the horizontal center portion of the belt. As previously noted, it is preferred that each of the rails 150 and 151 extends throughout the length of the input station. However, this is not essential; the input station can be constructed in longitudinal sections if desired.
As will be apparent from the foregoing description, it is readily possible to convert a prior art input station like station 20 of FIG. 1 to the input station construction of the invention, station 100 of FIG. 4 or station 120 of FIG. 5. The modification retains the existing frame, such as members 38, the stanchions 34-36, and the skirtboards 42 and 43. The aprons 44 and 45 are preferably replaced by improved aprons 144 and 145, but this is not essential.
What is necessary is the replacement of the side support rollers 32 and 33 of the conventional input station. This is done with two sets of the lateral support members 132 and 133, which may be the same in construction; each lateral support member should be directly mountable on one center-side stanchion combination, 34, 36 or 34, 37, in place of one of the side support rollers 32 or 33. Also needed are two sets of belt support rails 150 and 151 with bolts 136 or other mounting means to mount those rails on the lateral support members 132 and 133. The conversion members can be assembled as a kit to permit quick and convenient changeover.
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An input station for a belt conveyor of the kind including a continuous conveyor belt that moves in a conveyor run through an input station to a discharge location, around a head pulley, and in a return run around a tail pulley back to the input station and the conveyor run. At the input station the conventional center support rollers are retained but the support rollers along the sides of the belt are replaced by a plurality of elongated, stationary, flat support members that support the sides of the conveyor belt throughout the input station, improving the seal to input station skirtboards and materially reducing or eliminating input leakage while maintaining roller support and flexibility in the center of the belt, with minimal friction increase.
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TECHNICAL FIELD
[0001] The described technology is directed to the fields of business process reporting and dynamic diagramming.
BACKGROUND
[0002] Business process management, which are essentially workflow and tracking software applications, enable a company to automate and track business processes, also called “workflows,” that it uses frequently in its operation. For example, a company may use workflow tracking software to individually track the status of each of the number of different instances of an expense approval process, each of which must go through several different actions involving several different people.
[0003] To use such a workflow tracking application for a particular process, the company first defines the process in the workflow tracking application, such as by specifying the different actions that must be performed as part of the process, by whom, and in what order. Each time an instance of the process is started, the workflow tracking application is notified to identify the instance. Each time an action of the process is completed for an instance of the process, the workflow tracking application is notified so they can update its representation of the status of the instance.
[0004] Unfortunately, conventional workflow tracking applications have limited ways to display process instance status information for access and use by business users. In particular, these workflow tracking applications tend to display status information for one process instance at a time. Accordingly, a user of the workflow tracking application that wishes to understand the status of a large number of instances of a process must review individual reports on the status of each instance, and himself or herself aggregate this detailed information.
SUMMARY
[0005] A software facility automatically generates a workflow report diagrams that represents different instances of a process. This report consists of a graphical diagram depicting the process with information about the collective status of a number of different instances of the process, such as those instances of the process that concluded during the past week. The information added to the diagram by the facility may show, in connection with particular actions, the number of instances in which the action was performed, the average length of time required to perform the action across all of the instances, and/or an alert flag indicating whether the action is being performed satisfactorily across all of the instances. Where an action involves a decision branching to two or more different paths, the facility may add information to the diagram indicating the number of instances that took each path. The facility may add information to the diagram indicating the number of instances that completed successfully in the number that failed. In various embodiments, the information added to the diagram can be refreshed manually; refreshed automatically at a user-specified interval; and/or refreshed automatically in an event-driven manner when the instance statuses maintained by the workflow tracking application change.
[0006] In some cases, the facility provides a user interface for collecting information from a user to define the report diagrams, including information associating shapes in the diagram with status information stored by a workflow tracking application, and information specifying tests for whether a particular actions of the processor being performed satisfactorily.
[0007] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a block diagram illustrating an example of a suitable computing system environment or operating environment in which the facility may be implemented.
[0009] FIG. 2 is a report diagram showing a typical workflow report diagram generated by the facility.
[0010] FIG. 3 is a flow diagram showing steps typically performed by the facility in order to generate a workflow report diagram.
[0011] FIG. 4 is a table diagram showing sample contents of an action table containing process instance status information used by the facility.
[0012] FIG. 5 is a table diagram showing a query result for deriving information used by the facility for task actions.
[0013] FIG. 6 is a table diagram showing a query result for deriving information used by the facility for decision actions.
[0014] FIG. 7 is a table diagram showing a query result for deriving information used by the facility for start actions.
[0015] FIG. 8 is a table diagram showing a query result for deriving information used by the facility for end actions.
DETAILED DESCRIPTION
[0016] A software facility for automatically generating workflow report diagrams (“the facility”) is described. In some embodiments, the facility provides a user interface that enables a user to (1) associate shapes in a graphical diagram, each representing an action in the process with a location in a data store where the workflow tracking application stores information about the completion of the action by different instances of the process, and (2) define for some or all of the actions of the process conditions for displaying alerts in connection with the associated shapes in the diagram.
[0017] In response, the facility automatically augments the diagram with information retrieved from the data store about the collective status of a number of different instances of the process, such as those instances of the process that concluded during the past week. In some embodiments, the information added to the diagram by the facility shows, in connection with particular actions, the number of instances in which the action was performed, the average length of time required to perform the action across all of the instances, and/or an alert flag indicating whether the action is being performed satisfactorily across all of the instances. In some embodiments, where an action involves a decision branching to two or more different paths, the facility adds information to the diagram indicating the number of instances that took each path. In some embodiments, the facility adds information to the diagram indicating the number of instances that completed successfully in the number that failed. In various embodiments, the information added to the diagram can be refreshed manually; refreshed automatically at a user-specified interval; and/or refreshed automatically in an event-driven manner when the instance statuses maintained by the workflow tracking application change.
[0018] In various embodiments, the facility uses a variety of techniques for extracting instance status information maintained by a variety of workflow tracking applications, including employing database access techniques, processing an XML or XML variant version of the information generated by the workflow tracking application, and/or calling an API to retrieve the instance status information or register for updates to the instance status information. In some embodiments, the facility itself aggregates instance status information to obtain the information added to the diagram, while in others, the facility relies on the workflow tracking application or another helper application to perform such aggregation.
[0019] By automatically generating workflow report diagrams in some or all of the manners described above, the facility makes it easy to obtain information about how a business process being used in his or her company is performing, and at what points such performance needs improvement. It provides summary information for all the collective instances of the process, in a single graphical diagram.
[0020] FIG. 1 is a block diagram illustrating an example of a suitable computing system environment 110 or operating environment in which the facility may be implemented. The computing system environment 110 is only one example of a suitable computing environment and is not intended to suggest any limitation as to the scope of use or functionality of the facility. Neither should the computing system environment 110 be interpreted as having any dependency or requirement relating to any one or a combination of components illustrated in the exemplary operating environment 110 .
[0021] The facility is operational with numerous other general purpose or special purpose computing system environments or configurations. Examples of well-known computing systems, environments, and/or configurations that may be suitable for use with the facility include, but are not limited to, personal computers, server computers, handheld or laptop devices, tablet devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments that include any of the above systems or devices, and the like.
[0022] The facility may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, and so forth that perform particular tasks or implement particular abstract data types. The facility may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in local and/or remote computer storage media including memory storage devices.
[0023] With reference to FIG. 1 , an exemplary system for implementing the facility includes a general purpose computing device in the form of a computer 111 . Components of the computer 111 may include, but are not limited to, a processing unit 120 , a system memory 130 , and a system bus 121 that couples various system components including the system memory 130 to the processing unit 120 . The system bus 121 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include an Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus also known as a Mezzanine bus.
[0024] The computer 111 typically includes a variety of computer-readable media. Computer-readable media can be any available media that can be accessed by the computer 111 and include both volatile and nonvolatile media and removable and nonremovable media. By way of example, and not limitation, computer-readable media may comprise computer storage media and communications media. Computer storage media include volatile and nonvolatile and removable and nonremovable media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules, or other data. Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by the computer 111 . Communications media typically embody computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism and include any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communications media include wired media, such as a wired network or direct-wired connection, and wireless media, such as acoustic, RF, infrared, and other wireless media. Combinations of any of the above should also be included within the scope of computer-readable media.
[0025] The system memory 130 includes computer storage media in the form of volatile and/or nonvolatile memory such as read only memory (ROM) 131 and random access memory (RAM) 132 . A basic input/output system (BIOS) 133 , containing the basic routines that help to transfer information between elements within the computer 111 , such as during start-up, is typically stored in ROM 131 . RAM 132 typically contains data and/or program modules that are immediately accessible to and/or presently being operated on by the processing unit 120 . By way of example, and not limitation, FIG. 1 illustrates an operating system 134 , application programs 135 , other program modules 136 , and program data 137 .
[0026] The computer 111 may also include other removable/nonremovable, volatile/nonvolatile computer storage media. By way of example only, FIG. 1 illustrates a hard disk drive 141 that reads from or writes to nonremovable, nonvolatile magnetic media, a magnetic disk drive 151 that reads from or writes to a removable, nonvolatile magnetic disk 152 , and an optical disk drive 155 that reads from or writes to a removable, nonvolatile optical disk 156 , such as a CD-ROM or other optical media. Other removable/nonremovable, volatile/nonvolatile computer storage media that can be used in the exemplary operating environment include, but are not limited to, magnetic tape cassettes, flash memory cards, digital versatile disks, digital video tape, solid state RAM, solid state ROM, and the like. The hard disk drive 141 is typically connected to the system bus 121 through a nonremovable memory interface, such as an interface 140 , and the magnetic disk drive 151 and optical disk drive 155 are typically connected to the system bus 121 by a removable memory interface, such as an interface 150 .
[0027] The drives and their associated computer storage media, discussed above and illustrated in FIG. 1 , provide storage of computer-readable instructions, data structures, program modules, and other data for the computer 111 . In FIG. 1 , for example, the hard disk drive 141 is illustrated as storing an operating system 144 , application programs 145 , other program modules 146 , and program data 147 . Note that these components can either be the same as or different from the operating system 134 , application programs 135 , other program modules 136 , and program data 137 . The operating system 144 , application programs 145 , other program modules 146 , and program data 147 are given different numbers herein to illustrate that, at a minimum, they are different copies. A user may enter commands and information into the computer 111 through input devices such as a tablet or electronic digitizer 164 , a microphone 163 , a keyboard 162 , and a pointing device 161 , commonly referred to as a mouse, trackball, or touch pad. Other input devices not shown in FIG. 1 may include a joystick, game pad, satellite dish, scanner, or the like. These and other input devices are often connected to the processing unit 120 through a user input interface 160 that is coupled to the system bus 121 , but may be connected by other interface and bus structures, such as a parallel port, game port, or a universal serial bus (USB). A monitor 191 or other type of display device is also connected to the system bus 121 via an interface, such as a video interface 190 . The monitor 191 may also be integrated with a touch-screen panel or the like. Note that the monitor 191 and/or touch-screen panel can be physically coupled to a housing in which the computer 111 is incorporated, such as in a tablet-type personal computer. In addition, computing devices such as the computer 111 may also include other peripheral output devices such as speakers 195 and a printer 196 , which may be connected through an output peripheral interface 194 or the like.
[0028] The computer 111 may operate in a networked environment using logical connections to one or more remote computers, such as a remote computer 180 . The remote computer 180 may be a personal computer, a server, a router, a network PC, a peer device, or other common network node, and typically includes many or all of the elements described above relative to the computer 111 , although only a memory storage device 181 has been illustrated in FIG. 1 . The logical connections depicted in FIG. 1 include a local area network (LAN) 171 and a wide area network (WAN) 173 , but may also include other networks. Such networking environments are commonplace in offices, enterprisewide computer networks, intranets, and the Internet. For example, in the present facility, the computer 111 may comprise the source machine from which data is being migrated, and the remote computer 180 may comprise the destination machine. Note, however, that source and destination machines need not be connected by a network or any other means, but instead, data may be migrated via any media capable of being written by the source platform and read by the destination platform or platforms.
[0029] When used in a LAN networking environment, the computer 111 is connected to the LAN 171 through a network interface or adapter 170 . When used in a WAN networking environment, the computer 111 typically includes a modem 172 or other means for establishing communications over the WAN 173 , such as the Internet. The modem 172 , which may be internal or external, may be connected to the system bus 121 via the user input interface 160 or other appropriate mechanism. In a networked environment, program modules depicted relative to the computer 111 , or portions thereof, may be stored in the remote memory storage device 181 . By way of example, and not limitation, FIG. 1 illustrates remote application programs 185 as residing on the memory storage device 181 . It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used.
[0030] While various functionalities and data are shown in FIG. 1 as residing on particular computer systems that are arranged in a particular way, those skilled in the art will appreciate that such functionalities and data may be distributed in various other ways across computer systems in different arrangements. While computer systems configured as described above are typically used to support the operation of the facility, one of ordinary skill in the art will appreciate that the facility may be implemented using devices of various types and configurations, and having various components.
[0031] In order to more fully describe the facility, its operation in connection with a specific example is discussed hereafter.
[0032] FIG. 2 is a report diagram showing a typical workflow report diagram generated by the facility. The report is for an expense approval process, and is based upon a drawing created using the MICROSOFT VISIO application program made up of shapes 201 - 210 . The report is for a period of time during which 58 instances of the process were performed. These instances are termed “subject instances,” because they are the instances of the process that are the subject of the report. In various embodiments, the facility selects as subject instances all instances that began during a subject period, all instances that ended during the subject period, or all instances that both began and ended during the subject period. In some embodiments, rather than selecting subject instances based upon a subject period, for particular number of instances n, the facility selects the n most recently begun or most recently ended instances.
[0033] The facility has augmented start shape 201 by adding the total number of subject instances of the process, 58. The facility has augmented shape 202 for a “Complete purchase expense form” task by adding the following: the average duration of this task across the subject instances, 4 days, as well as a green flag indicating that the task was performed satisfactorily during the subject instances; that is, the task has a satisfactorily short average duration across the subject instances. The facility has augmented shape 203 for a “Send in receipts” task by adding the following: the average duration of this task across the subject instances, 1 day, as well as a green flag indicating that the task was performed satisfactorily during the subject instances. The facility has augmented shape 204 for a “Amt>$75?” decision by adding the following: the total number of subject instances in which the no path to shape 209 was followed from this decision, 7 , as well as the total number of subject instances in which the yes path to shape 205 was followed from this decision, 51. The facility has augmented shape 205 for a “Manager review” task by adding the following: the average duration of this task across the subject instances, 2 days, as well as a yellow flag indicating that the task was performed in a borderline fashion during the subject instances; that is, the task has an average duration across the subject instances that is in a range of medium acceptability. The facility has augmented shape 206 for a “Manager approves?” decision by adding the following: the total number of subject instances in which the no path to shape 210 was followed from this decision, 11 , as well as the total number of subject instances in which the yes path to shape 207 was followed from this decision, 40. The facility has augmented shape 207 for a “Purchasing clerk review” task by adding the following: the average duration of this task across the subject instances, 15 days, as well as a red flag indicating that the task was performed on satisfactorily during the subject instances; that is, the task has an average duration across the subject instances that exceeds a threshold of minimum acceptability. The facility has augmented shape 208 for a “Purchasing clerk approves?” decision by adding the following: the total number of subject instances in which the no path to shape 210 was followed from this decision, 10, as well as the total number of subject instances in which the yes path to shape 209 was followed from this decision, 30. The facility has augmented shape 209 for an “Issue payment” task by adding the following: the average duration of this task across the subject instances, 1 day, as well as a green flag indicating that the task was performed satisfactorily during the subject instances. The facility has augmented end shape 210 by adding the total number of subject instances that were successfully completed, 37 (all arriving from shape 209 , 7 via the no path from shape 204 and 30 via the yes path from shape 208 ), as well as the total number of subject instances that were terminated, i.e., not successfully completed, 21 (11 via the no path from shape 206 , 10 via the no path from shape 208 ).
[0034] It can be seen at the report provides valuable aggregate information about the overall operation of the process. The report shows that 37 of 58 reimbursement requests were granted, or 64%; in 7 of 51 or 14% of the instances, both of the Manager review and Purchasing clerk review actions were obviated by a policy exempting requests for amounts no larger than $75; the Complete purchase expense form action, Send in receipts action, and Issue payment action are all being performed promptly by those responsible for them, while the Purchasing clerk review action is a significant bottleneck likely to merit attention from a person responsible for the process, and the Manager review action may also need to be addressed.
[0035] In some embodiments, the facility generates the report in such a way that the user can click anywhere on the report to display a more detailed version of process instance status information for all of the subject instances and actions. In some embodiment, the facility generates a report in such a way that the user can drill down on details of particular portions of the report. For example, in some embodiments, the user can click on a shape in the report to obtain additional details about the corresponding action. In some embodiments, the user can click on a count of instances, such as a count of instances that exited a decision action along the particular path, to obtain additional details about those instances.
[0036] Those skilled in the art will appreciate that a variety of other presentation techniques may be used by the facility in augmenting the drawing. As one example, a wide variety of indicator types may be used to show the degree to which a shape's average duration is acceptable, such as smiling/frowning faces, arrows pointing up or down, etc. as another example, counts of instances may be portrayed in a variety of other ways, such as using bar or pie graphs.
[0037] In order to support the operation of the facility, templates for four different types of shapes are either included with the drawing program or provided as a supplement to the drawing program: a start shape, an end shape, a task shape, and a decision shape. The templates for all the shapes include a property identifying a particular action in the process as defined in the workflow tracking application to which the shape corresponds. The template for the start shape includes a property indicating the number of subject instances that can be linked to the appropriate point in the data source maintained by the workflow tracking application. The template for the end shape includes a property for each the number of subject instances completed and the number of subject instances terminated that can each be linked to the appropriate point in the data source maintained by the workflow tracking application. The template for the task shape includes a property indicating the average duration of the task that can each be linked to the appropriate point in the data source maintained by the workflow tracking application, as well as properties that can be set to establish duration ranges for displaying alert flags. The template for the decision shape includes a property for the number of instances following each of the paths out of the shape that can be linked to the appropriate point in the data source maintained by the workflow tracking application.
[0038] While creating the drawing using these shape templates, or after the drawing has been completed, the user sets the properties above to enable the facility to generate the report by populating the additional displayed properties for any set of subject instances of the process. As a first matter, the user sets shape properties that associate information to be displayed in connection with each shape with the location in the workflow tracking application's data store or a separate data feed produced from the workflow tracking application's data store where this information is available. As is described in greater detail below in connection with FIGS. 3-8 , for most shapes this involves storing a copy of an ActionID identifying the action in the workflow tracking application to which the shape corresponds. In the case of decision shapes, this involves storing, for each branch from the decision shape, a label for the branch, as well as an ActionID identifying the action to which the branch leads. In some embodiments, the facility provides a user interface to facilitate the setting of these properties. In some embodiments, aspects of this user interface are implemented as described in U.S. patent application Ser. No. 11/012,875 filed on Dec. 15, 2004, which is hereby incorporated by reference in its entirety. As a second matter, the user sets shape properties that specify average duration ranges that determine what color alert flag is displayed in connection with the shape for particular average duration value. In some embodiments, aspects of this user interface are implemented as described in U.S. patent application Ser. No. 11/105,115 filed on Apr. 11, 2005, which is hereby incorporated by reference in its entirety.
[0039] FIG. 3 is a flow diagram showing steps typically performed by the facility in order to generate a workflow report diagram. After the process drawing has been created and the properties of its shapes set as discussed above, these steps can be performed at any time to generate a new workflow report diagram for the process, in response to either user or programmatic initiation. In some embodiments, these steps are repeated periodically in order to maintain and up-to-date workflow report diagram or in response to the expiration of a periodic polling interval.
[0040] In steps 301 - 307 , the facility loops through each shape of the diagram. In step 302 , the facility branches on the type of the shape to store in the shape the information needed for its shape type: if the shape is a task shape, then the facility continues in step 303 ; if the shape is a decision shape, then the facility continues in step 304 ; if the shape is a start shape, then the facility continues in step 305 ; if the shape is an end shape, then the facility continues in step 306 . Different approaches used by the facility in various embodiments to obtain this information are described below after FIG. 3 .
[0041] In step 303 , the facility associates with the task shape the average action duration across all of the subject instances. After step 303 , the facility continues in step 307 . In step 304 , the facility associates with the decision shape the number of subject instances that followed each exit path from the decision shape. After step 304 , the facility continues in step 307 . In step 305 , the facility associates with the start shape the total number of subject instances. After step 305 , the steps continue in step 307 . In step 306 , the facility associates with the end shape the total number of completed subject instances and the total number of terminated subject instances.
[0042] In step 307 , if additional shapes remain in the diagram to be processed, then the facility continues in step 301 to process the next shape of the diagram, else the facility continues in step 308 . In step 308 , the facility displays the shapes of the diagram, including both the values associated with each shape in steps 303 - 306 and, in the case of some or all of the task shapes, flags whose colors are each based upon applying a test specified for the shape to and attributed average duration value. After step 308 , these steps conclude.
[0043] Those skilled in the art will appreciate that the steps shown in FIG. 3 may be altered in a variety of ways. For example, the order of the steps may be rearranged; substeps may be performed in parallel; shown steps may be omitted, or other steps may be included; etc.
[0044] In some embodiments, the process instance status information used by the facility is directly extracted from the database maintained by the workflow tracking application, either by the facility or an intermediary program. FIG. 4 is a table diagram showing sample contents of an action table containing process instance status information used by the facility. The action table 400 is made up of rows, including rows 401 - 413 , each corresponding to a particular action of a particular process instance. Note that, while the sample contents of this table that are shown correspond generally to the example shown in FIG. 2 , for the sake of brevity, rows are included for only two of the 58 instances depicted in that example. Each row is divided into the following columns: a TypeID column 451 containing a TypeID value corresponding to the process type to which the row corresponds, here an expense reimbursement process; a UniqueID column 452 containing a UniqueID value identifying a particular instance of the process to which the row corresponds; an ActionID column 453 containing an ActionID value identifying a particular action of the process to which the row corresponds; NextActionID column 454 containing the ActionID of the action that was performed in the instance of the process to which this row corresponds immediately after the action to which this row corresponds; a status column 455 that indicates the result of performing the action to which this row corresponds (The status “concluded” means that the action to which the row corresponds has finished; the status “completed” means that the instance to which the row corresponds succeeded; and the status “terminated” means that the instance to which the row corresponds failed.); and a duration column 456 indicating the amount of time that the actions which the row corresponds took to complete, expressed here in days. For example, rows 401 - 406 indicate that instance 1 of the process began in action 1 , which concluded in zero days; the instance continued in action 2 , which concluded in five days; the instance continued in action 3 , which concluded in two days; the instance continued in action 4 , which concluded in zero days; the instance continued in action 9 , which concluded two days; and the instance continued in action 10 , where it completed in zero days.
[0045] While FIG. 4 and each of the table diagrams discussed below show a table whose contents and organization are designed to make them more comprehensible by a human reader, those skilled in the art will appreciate that actual data structures used by the facility to store this information may differ from the table shown, in that they, for example, may be organized in a different manner; may contain more or less information than shown; may be compressed and/or encrypted; etc. Indeed, the contents of various fields may be encoded in different ways than the ways that are shown here for legibility. For example, any of the contained IDs may be represented as globally-unique IDs. Also, the status values may be encoded as whole number values or using other constant representations. Further, duration values may be expressed in a number of different units, or may be expressed with reference to absolute times at which the action began and/or ended.
[0046] FIGS. 5-8 show query results that can be derived from the action table and used to support the operation of the facility. It should be noted that, to facilitate comparison between FIGS. 5-8 in FIG. 4 , only the rows explicitly shown in FIG. 4 have been used to generate the contents of FIGS. 5-8 . Also, though not discussed explicitly below, in some embodiments the facility selects rows in a way that is also based upon TypeID and other qualifiers for subject instances, such as instance start and/or end date.
[0047] FIG. 5 is a table diagram showing a query result for deriving information used by the facility for task actions. The query result 500 contains, for each unique ActionID contained in the action table, the average of the duration values among the rows containing that action ID. For example, row 502 indicates that the action having ActionID 2 took an average of 4.5 days to perform, based on the intersection of rows 402 and 408 with Duration column 456 . If FIG. 5 reflected the full contents of the action table supporting the report shown in FIG. 2 , row 502 would instead report an average duration of 4 days as shown in shape 202 .
[0048] FIG. 6 is a table diagram showing a query result for deriving information used by the facility for decision actions. The query result 600 contains, for each unique combination of ActionID and NextActionID contained in the action table, the number of rows containing that combination. For example, row 604 indicates that the decision action having ActionID 4 took the yes path to action 5 in one instance based on the contents of row 410 , while row 604 indicates that the decision action having ActionID for took the no path to action 209 in one instance based on the contents of row 404 . If FIG. 6 reflected the full contents of the action table supporting the report shown in FIG. 2 , the table would instead report 51 instances in row 604 and 7 instances in row 605 as shown in shape 204 .
[0049] FIG. 7 is a table diagram showing a query result for deriving information used by the facility for start actions. The query result 700 contains a unique count of all of the UniqueID values in the action table, which is reflective of the number of subject instances displayed in start shapes. Row 701 indicates that the table contains two of these, based on rows 401 - 406 and 407 - 413 . If FIG. 6 reflected the full contents of the action table supporting the report shown in FIG. 2 , row 701 would instead report a value of 58 as shown in shape 201 .
[0050] FIG. 8 is a table diagram showing a query result for deriving information used by the facility for end actions. The query result 800 contains, for each unique status value contained in the action table, the number of rows containing that status value. Row 802 indicates that 1 action completed based on row 406 , while row 803 indicates that one action terminated based on row 403 . If FIG. 5 reflected the full contents of the action table supporting the report shown in FIG. 2 , the table would instead report 37 in row 802 and 21 in row 803 as shown in shape 210 .
[0051] In some embodiments, the process instance status information used by the facility is converted from a form in which is maintained by the workflow tracking application into an XML or SolutionXML document, either by workflow tracking application, the facility, or an intermediary program. In some embodiments, this information is converted from a form defined by the Business Process Modeling Notation specification available at www.bpmn.org.
[0052] The SolutionXML representation uses the tags described below in Table 1.
TABLE 1 1 <TypeID> corresponds to column 451 of action table 2 <UniqueID> corresponds to column 452 of action table 3 <Action ID> corresponds to column 453 of action table 4 <NextActionID> corresponds to column 454 of action table 5 <Status> corresponds to column 455 of action table 6 <Duration> corresponds to column 456 of action table
[0053] A version of the information contained in the action table shown in FIG. 4 represented in SolutionXML is shown below in Table 2.
TABLE 2 1 <TypeID> 11 2 <UniqueID> 1 3 <ActionID> 1 4 <NextActionID> 2 5 <Status> concluded 6 <Duration> 0 7 </ActionID> 8 <ActionlD> 2 9 <NextActionID> 3 10 <Status> concluded 11 <Duration> 5 12 </ActionID> 13 <ActionID> 3 14 <NextActionID> 4 15 <Status> concluded 16 <Duration> 2 17 </ActionID> 18 <ActionID> 4 19 <NextActionID> 9 20 <Status> concluded 21 <Duration> 0 22 </ActionID> 23 <ActionID> 9 24 <NextActionID> 10 25 <Status> concluded 26 <Duration> 2 27 </ActionID> 28 <ActionID> 10 29 <NextActionID> 0 30 <Status> completed 31 <Duration> 0 32 </ActionID> 33 </UniqueID> 34 <UniqueID> 2 35 <ActionID> 1 36 <NextActionID> 2 37 <Status> concluded 38 <Duration> 0 39 </ActionID> 40 <ActionID> 2 41 <NextActionID> 3 42 <Status> concluded 43 <Duration> 4 44 </ActionID> 45 <ActionID> 3 46 <NextActionID> 4 47 <Status> concluded 48 <Duration> 1 49 </ActionID> 50 <ActionID> 4 51 <NextActionID> 5 52 <Status> concluded 53 <Duration> 0 54 </ActionID> 55 <ActionID> 5 56 <NextActionID> 6 57 <Status> concluded 58 <Duration> 3 59 </ActionID> 60 </ActionID> 6 61 <NextActionID> 10 62 <Status> concluded 63 <Duration> 0 64 </ActionID> 65 <ActionID> 10 66 <NextActionID> 0 67 <Status> terminated 68 <Duration> 0 69 </ActionID> 70 </UniqueID> 71 </TypeID>
[0054] In order to obtain the average duration for a task shape from the SolutionXML representation, the facility divides the sum of the values of the <Duration> tags under the <ActionID> tags containing the ActionID value corresponding to the shape by the number of <ActionID> tags containing the ActionID value corresponding to the shape. In Table 2, for shape 2 , the facility averages five days from the <Duration> tag in line 11 with four days from the <Duration> tag in line 43 to obtain a result of 4.5 days.
[0055] In order to obtain the number of instances that followed each exit path from a decision shape, the facility counts the number of each value of the <NextActionID> tag under the <ActionID> tags containing the ActionID value corresponding to the shape. In Table 2 for shape 4 , the facility counts one exit along the no path in line 19 and one exit along the yes path in line 51 .
[0056] In order to obtain the total number of subject instances for a start shape, the facility counts the number of unique values among the <UniqueID> tags. In Table 2 for shape 1 , the facility counts unique value 1 of the <UniqueID> tag in line 2 and unique value 2 of the <UniqueID> tag in line 34 to obtain a result of two instances.
[0057] In order to obtain the total number of completed and terminated instances for an end shape, the facility counts the <UniqueID> tags having each completed and terminated values of <Status> tags under <ActionID> tags containing the ActionID value corresponding to the shape. In Table 2 for shape 10 , the facility counts one completed iteration in line 30 and one terminated iteration in line 67 .
[0058] In some embodiments, rather than a SolutionXML representation that separately reflects each action of each iteration, the facility uses a SolutionXML representation that contains aggregations across all subject iterations for each action. An example of such a SolutionXML representation is shown below in Table 3.
TABLE 3 1 <TypeID> 11 2 21 ActionID> 1 3 <NextActionID> 4 <2> 2 5 </NextActionID> 6 <Status> 7 <concluded> 2 8 </Status> 9 <Duration> 0 10 </ActionID> 11 <ActionID> 2 12 <NextActionID> 13 <3> 2 14 </NextActionID> 15 <Status> 16 <concluded> 2 17 </Status> 18 <Duration> 4.5 19 </ActionID> 3 20 <NextActionID> 21 <4> 2 22 </NextActionID> 23 <Status> 24 <concluded> 2 25 </Status> 26 <Duration> 1.5 27 </ActionID> 28 <ActioniD> 4 29 <NextActionID> 30 <5> 1 31 <9> 1 32 <Status> 33 <concluded> 2 34 </Status> 35 <Duration> 0 36 </ActionID> 5 37 <NextActionID> 38 <6> 1 39 </NextActionID> 40 <Status> 41 <concluded> 1 42 </Status> 43 <Duration> 3 44 </ActionID> 45 </ActionID> 6 46 <NextActionID> 47 <10> 1 48 </NextActionID> 49 <Status> 50 <concluded> 1 51 </Status> 52 <Duration> 0 53 </ActionID> </ActionID> 9 54 <NextActionID> 55 <10> 1 56 </NextActionID> 57 <Status> 58 <concluded> 1 59 </Status> 60 <Duration> 2 61 </ActionID> 62 <ActionID> 10 63 <NextActionID> 64 <0> 2 65 </NextActionID> 66 <Status> 67 <completed> 1 68 <terminated> 1 69 </Status> 70 <Duration> 0 71 </ActionID> 72 </TypeID>
[0059] It will be appreciated by those skilled in the art that the above-described facility may be straightforwardly adapted or extended in various ways. For example, the facility may be used in connection with a wide variety of workflow tracking applications, drawing applications, and process instance status and drawing data formats. While the foregoing description makes reference to particular embodiments, the scope of the invention is defined solely by the claims that follow and the elements recited therein.
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A facility for providing a workflow report document for a number of instances of a business process is described. In connection with information specifying the display of an arrangement of shapes each representing a constituent action of the business process, the facility provides information specifying the display in connection with shapes of the arrangement of at least one business process measure aggregated across all of the instances of the process.
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BACKGROUND OF THE INVENTION
This invention relates to a method and apparatus for rapid formation of a highly uniform nonwoven web of staple fibers and is particularly suitable for the formation of the low basis weight webs of thermoplastic fibers at a high rate of speed.
Nonwoven fabrics are produced by a variety of methods, and in general, such methods involve the continuous laydown of fibers or filaments in the form of an unconsolidated flat web on a conveyor, followed by consolidation of the web, such as by bonding or locking the fibers together to form the web into a cohesive fabric.
The carding of staple fibers into an unconsolidated web followed by point bonding with a hot calender is one well known method of producing a nonwoven fabric. In such a process the fibers, which are received in bales, are first opened with standard textile opening equipment. The opened fibers are then fed to single or multiple cards which are installed in line, each forming a thin web. The webs are then layered together, then usually spread to increase web width, and fed to a hot calender for thermal bonding. The customary calender consists of two heated rolls, one being a smooth steel anvil roll, the other being a roll with an embossed pattern. The high points of the pattern are the area where the fibers are bonded together through partial melting. Such systems can produce webs which are reasonably uniform at a given speed and basis weight. Typically, a reduction in unit weight or an increase in speed results in a noticeable degradation in the uniformity of the fiber distribution. More precisely, at lower basis weights the web develops a more blotchy appearance due to areas of higher and lower concentrations of fibers. In the worst case, holes will form where the concentration of fiber is low. The degradation in web uniformity for the traditional system is also linked to the need of additional draw on the unbonded web to eliminate the bulging of the web which would otherwise occur at various points in the process. The amount of draw used to control the web during transport to the calender is inversely proportional to the cohesion of the unbonded web. A low cohesion web will require a higher draw. The spreading section and the calender nip point are prime areas where the bulging occurs. This bulging, if not eliminated, causes extremely poor web uniformity. A lighter web, when submitted to such increase in draw, develops even greater defects because the extremely light areas are now deformed into holes in the web.
The prior art has tried to minimize the requirement for draw by using equipment transfer geometry and higher cohesion fiber to produce nonwoven material at higher production speeds. Both modifications have produced only moderate improvements in speed or uniformity.
Other prior art has been the development of a machine which reorganizes the carded unbonded web (with minimal or no increase in output speed) by reforming it on a vacuum collector such as described in U.S. Pat. No. 4,475,271. This process can produce a web with a more uniform balance in tensile strength between the MD and CD direction but, it does not deliver the desired level of uniformity in fiber distribution as judged by visual appearance.
SUMMARY OF THE INVENTION
In accordance with the present invention, a slow moving thick or high basis weight web of fibers having a high degree of cohesion, is formed using conventional cards, or other mechanisms. This web may be first spread in the cross machine direction.
The thick web is fed into a relatively fast moving toothed reforming roll, which carries a layer of excess recirculating fibers needed to form the final web. A uniform portion of the layer of fibers is continuously removed from the reforming roll by a toothed web forming roll, and this web layer is transferred as a web to a conveyor by a transfer roll. The web is subsequently bonded.
In the preferred embodiment, the reformed web is fed from the conveyor around an air control transfer roll, which allows the web to change direction without lifting or disruption, with the exit of the air control roll being located closely adjacent the upper heated roll of the rotating calender rolls.
The web is not fed directly into the nip between the calender rolls. Rather, the web is transferred to the upper hot calender roll into a secondary nip between the transfer roll and hot calender roll, in an area upstream of the nip. The unconsolidated web is then heated and compressed in the secondary nip and is supported on the hot roll prior to entry into the calender nip to become thermally bonded.
As the web passes through the secondary nip, the web is compressed, causing fibers to move relative to each other in a more uniform arrangement. This effect is aided by contact of the web with the heated roll in which individual heated fibers may shrink, curl or relax as they are being physically rearranged by compression. The rearranged web is partially wrapped and supported on the heated roll, which tends to eliminate any bulging of the web due to passage through the calender.
Downstream of the reformer roll, all rolls and conveyor operate at substantially the same surface speed, and no substantial machine direction draw is imparted to the reformed web due to transport or thermal bonding. Thus, very light weight or low cohesive webs may be processed at high speeds without any loss in uniformity, and, in fact, uniformity is increased in the final stages of processing.
In summary, the invention can be considered as having several general aspects. First, a web of staple fibers having a first basis weight and moving at a first speed is converted into a second, more uniform web having a second, lower basis weight and moving at a second, higher, surface speed. This is accomplished by continuously metering a layer of fibers from the first web onto a rapidly rotating toothed cylinder and removing a uniform portion of said layer to form the second web moving at the second speed. The second web is subsequently bonded.
In a broad second aspect, a web of individual fibers, including at least some thermally bondable fibers, is subjected to preconditioning immediately prior to passage through a nip of a bonding calender. The preconditioning involves subjecting the web to heat and compression which is sufficient to at least partially rearrange the fibers in a more uniform array, but insufficient to thermally bond the fibers.
A third broad aspect comprises supporting a web of unbonded thermoplastic fibers on a heated surface immediately prior to entry into the nip of a calender. The second and third aspects are preferably accomplished using a heated roll of the calender to heat, compress and support the web upstream of the bonding nip.
A fourth broad aspect is to support the web of individual fibers to be thermally bonded at a substantially constant surface speed between the zone of formation and into and through the bonding zone in order to minimize any draw on the web after final web formation and to prevent loss of uniformity due to draw.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side schematic view of the overall apparatus for carrying out the method of the present invention.
FIG. 2 is an enlarged portion of a first part of the apparatus shown in FIG. 1 .
FIG. 3 is an enlarged portion of a second part of the apparatus shown in FIG. 1 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows the overall apparatus representative of a production line capable of carrying out the various aspects of the present invention.
A relatively thick or high basis weight of a web 10 of unconsolidated fibers is first prepared. The web 10 may be formed by use of one and preferably a series of a plurality of conventional cards 12 which serve to separate clumps of fibers from a bale into individual fibers and to deposit the fibers via a take-off roll 14 onto a moving conveyor 16 .
The web 10 comprises individual staple fibers which are capable of being bonded by conventional techniques. The initial part of the present method may be used to form uniform webs of fibers which are subsequently consolidated by thermal or non-thermal means. Non-thermal methods include techniques in which the surfaces of the fibers are not melted or softened to achieve bonding, including techniques such as chemical or adhesive (liquid or solid) bonding and hydraulic entanglement. In such cases, polymer fibers having higher melting points can be employed, such as polyester and polyamide, as well as other fibers such as polyolefin.
The web as initially formed may also be bonded by thermal methods such as the application of heat, pressure and heat, or by the use of sonic techniques. Thermal bonding methods include, for example, through-air bonding using hot air, and passage of the web through the nip of a pair of heated calender rolls, one having an embossed surface with raised areas to define the bond sites. In such a case, fibers which have a relatively low melting point are used alone or in admixture with other fibers. Suitable thermoplastic fibers of this nature include polyolefins, such as polyethyle and polypropylene, multi-component fibers having an outer polyolefin surface, uand mixtures thereof. In the preferred embodiment, the fibers or fiber mixtures are capable of being bonded by passage through a conventional bonding calender.
The initially formed web 10 , typically having a basis weight of from about 30 to about 90 grams per square meter (gsm) may be conveyed from the conveyor 16 to a conventional spreader 18 , which functions to increase the width of the web 10 in the cross machine direction. Since the web is relatively thick and cohesive at this stage, the spreading operation does not cause excessive loss in gross uniformity. At this stage, the web will be moving at a speed in the order of from about 50 to about 80 meters per minute.
The above apparatus is conventional in nature and provides an initial feed web for subsequent processing in accordance with the present invention. The use of any known process for opening and individualizing fibers to form the initial web 10 is expected to suffice for the purpose of the present invention.
In accordance with the present invention, the initial web 10 is first processed through a web reformer station 20 which results in a highly uniform web 22 having a basis weight of from about 20 to about 70 percent of the basis weight of the initial web, typically 10 to 30 gsm, and moving at a line speed of from about 150 to 500 percent greater than the line speed of the initial web, typically in the order of 150 to 250 meters per minute. The web 22 is then conveyed to a final fiber rearrangement and bonding station 24 , wherein the fibers are subjected to additional mechanical and thermal rearrangement shortly prior to bonding.
The reformer station 20 is shown in FIG. 2, with the feed web 10 and reformed web 22 being omitted between rolls for the sake of clarity. The initial web 10 exits a conveyor 26 and is deposited between a lower curved support 28 and a toothed feed roll 30 . The feed roll 30 meters fibers onto a toothed cylinder 32 operating at substantially a faster surface speed and in the same direction (see arrows) than the feed roll. Semi-cylindrical covers 34 are preferably provided around the moving periphery of cylinder 32 in a closely spaced relation to uniformly guide the flow of air created by the cylinder and to prevent disturbance of fibers residing thereon by outside influences. The fibers are not carded by the cylinder 32 , as this would reduce production speed.
A toothed forming roll 36 is provided, at a close distance from the cylinder 32 and rotates in an opposite rotary direction. The cylinder 32 deposits a uniform layer of fibers resident as the outer layer of fibers on the cylinder onto the forming roll 36 . Thus, the cylinder 32 carries an amount of fibers in excess of that required to establish the reformed or second web 22 . As the cylinder 32 rotates past the feed roll 30 , areas lacking a sufficient population of fibers to form a uniform layer will tend to pick up more fibers from the feed. Thus, the feed roll, cylinder and forming roll work in dynamic conjunction to provide a highly uniform web of unbonded fibers at a high rate of speed. The surface speed of the cylinder 32 is substantially greater than the surface speed of the forming roll 36 , preferably in the order of from about 3.5 to about 10 times faster.
A toothed takeoff roll 38 , located at a close distance from the forming roll 36 and rotating in an opposite direction, removes the entire reformed web 22 from the forming roll and deposits the same on a moving conveyor 40 , which is preferably upwardly inclined relative to horizontal machine direction travel.
The reformed web of individual fibers 22 , which is now in a highly uniform and fast moving state, may be consolidated or bonded by any suitable thermal or non-thermal technique as described hereinabove. Preferably, however, the web 22 comprises heat bondable fibers and is subjected to additional conditioning, followed by bonding by passage through a conventional heated calender having one or two pattern rolls.
In the preferred embodiment, the reformed web 22 is subjected to final processing and bonding at the station 24 as shown in FIG. 3 . The conveyor belt 40 is preferably of mesh construction allowing air flow therethrough of at least 300 CFM per square foot. An air flow transfer roll 42 supports the exit return loop of the conveyor belt 40 . A pair of spaced fixed radial air seals 44 and 46 are provided across the width of the roll 42 . The first seal 44 intersects the belt 40 and the supported web 22 at approximately the 12 o'clock position on roll 42 , as shown.
A calender apparatus is provided closely adjacent the air transfer roll 42 and comprises an upper smooth heated roll 48 and a lower embossed or patterned roll 50 , rotating in opposite directions as indicated by the arrows as shown. In the alternative, the upper roll 48 may have an embossed or patterned surface, and the lower roll 50 may be patterned or smooth. The upper roll 48 is in tangential relation with the air transfer roll 42 and is slightly spaced therefrom, as will be explained in greater detail. A first nip 52 is defined between the calender rolls 48 and 50 , where thermal/pressure bonding occurs, and a second nip 54 , upstream of the first nip, is defined between the air transfer roll 42 and the upper calender roll 48 . The second seal 46 intersects the second nip 54 .
Suitable means, such as an air pump 56 , are connected to a plenum chamber 58 to cause a uniform flow of air to be drawn through the porous conveyor belt 40 and into and across the web 22 in the zone between the fixed seals 44 and 46 . Since the web will typically be light in weight and highly porous, the purpose of this air flow is not to provide a positive pressure drop or seal for the transfer process. Rather, the purpose is to control the boundary layer air which would normally move away from the roll as speed is increased. The negative air flow allows the web to be transferred without disturbance and also prevents the possibility of turbulence and hence disruptive forces at the second nip 54 .
It has been found that the nip 54 established between the rolls 42 and 48 should be in the order or 0.250 in. (0.635 cm) or less. As the reformed web 22 enters the nip 54 , the web is compressed between the two rolls, and the fibers in the web are heated by the hot calender roll. The simultaneous heating and compression causes at least a partial rearrangement of the fibers due to mechanical and thermal influences, allowing the fibers to shrink and relax as well as to move relative to one another and in three dimensions into the most efficiently packed or uniform arrangement while the fibers remain unbonded.
The web 22 adheres to and is supported by the heated calender roll through a quadrant of rotation 60 until the web passes through the first nip 52 where permanent point bonding between the fibers occurs. In prior art arrangements the web passes through an unsupported area prior to the nip of the calender, and due to compressive forces at the nip, a bulge in the web can form prior to the nip, with the only available solution being to increase the machine direction draw on the web by increasing the speed of the calender rolls relative to the speed of the web feed. In the present arrangement, the final rearrangement of the fibers and the support of the web on the roll 48 serve to eliminate any tendency to bulge.
Apparatus of the prior art requires a substantial amount of draw to enable processing. In the present apparatus, the draw between the forming roll 36 and the bonding nip 52 , if any, is less than 5% and most preferably less than 3%. Thus, the surface speed of all components downstream of the cylinder 34 is substantially the same. As a result, bonded webs of a low basis weight and uniformity can be formed at a speed up to 30-40% greater than available on a conventional line. As a result, it is possible to produce light weight nonwoven webs of very high uniformity and at high production rates and low cost, in comparison to prior art methods.
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In the production of a nonwoven fabric of thermally bonded fibers, a heavy web of fibers is continuously fed to a toothed cylinder at a slow speed to form a layer of fibers, and a portion of this layer is removed and formed into a lightweight uniform web at a faster speed. The second web is conveyed without draw to a calender having a bonding nip, and the fibers of the web are rearranged by compression and heating and are supported on a hot surface of one of the calender rolls prior to entering the nip to additionally improve uniformity.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/896,213 filed Mar. 21, 2007.
BACKGROUND OF THE INVENTION
[0002] The present invention is in the field of ground fault interrupters (GFI's) and, more particularly, GFI's in power distribution systems which operate in vehicles such as aerospace vehicles.
[0003] In modern day aerospace vehicles, power distribution systems may incorporate ground fault protection. In a typical prior art vehicle, current transformers are employed as part of the apparatus needed to detect current variations and interrupt current if and when a ground fault event occurs. Prior art ground fault interruption (GFI) is realized by detecting differential current using a current transformer, comparing the differential current with a threshold value, and interrupting current from a power source through a remote power controller when the differential current exceeds the threshold value. Current transformers are expensive and their use adds weight to an aerospace vehicle. Also use of current transformers increases system interconnection complexity and reduces flexibility of SSPC system. As is the case for virtually any type of complexity, interconnection complexity may present opportunities for failures and may contribute to reduced overall reliability of a power system of an aerospace vehicle.
[0004] An alternate method to current transformer type GFI is provided by performing current sum digitally. But, many aerospace vehicles employ multi-phase power distribution (e.g. 3 phase power). Precision of the digital current sum GFI performance may be affected by errors in detecting actual current differentials between respective phases. Phase angle variations may produce one form of current differential error. Also current transformers may not be capable of perfectly representing actual current in a phase. Collectively, these factors may produce a current differential error. Presence of such potential errors in detecting actual current may adversely affect the precision with which prior art GFI systems may operate.
[0005] In order to avoid false tripping, a GFI device or system must be allowed to ignore a current differential that is equal to or less than an error differential. For example, if an error differential has a potential for appearing as a current variation of 1% between phases, then a GFI trip level must be set so that the GFI operates only after an actual current variation or current reading differential exceeds 1%.
[0006] As aerospace vehicles evolve, there is an increased demand for lower weight of components. There is also a developing need for increased reliability of individual systems because there are an increasing number of systems being incorporated into aerospace vehicles. Overall reliability of vehicles with an increasing number of systems may only be sustained if reliability of each system is improved. In that context, interconnection complexity associated with use of current transformers for GFI functions is counterproductive.
[0007] As can be seen, there is a need to provide for ground fault interruption without use of current transformers. There is also a need to provide trip levels of ground fault interruption devices lower than prior-art differentials in multi-phase power systems.
SUMMARY OF THE INVENTION
[0008] In one aspect of the present invention a power distribution control system with ground fault interruption (GFI) protection comprises a current measurement sensor for a first conductor, a current measurement sensor for a second conductor, analog to digital converters to convert current measurements to a first digital representation of current in the first conductor and to a second digital representation of current in the second conductor, and a digital processor that receives the first and second digital representations. The processor calculates differentials between the digital representations and produces a current interruption signal in the event that a calculated differential exceeds a pre-defined value.
[0009] In another aspect of the present invention a control system for multi-phase power distribution with ground fault interruption (GFI) protection comprises a plurality of DSP based trip engines which perform instantaneous sampling of current values of each power feeder of the multi-phase power distribution system. The trip engines produce digital representations of the sampled current values. A processor is interconnected with the trip engines to receive the digital representations and determine if a differential between current values of the power feeders exceeds a predefined limit. Solid-state switches are interconnected with each of the trip engines to interrupt current in the power feeders upon receiving a switch-off signal from an associated one of the trip engines, which switch-off signal is generated responsively to a determination by the processor that the differential exceeds the predefined limit. GFI protection is thus provided without use of current transformers.
[0010] In still another aspect of the present invention a method for performing ground fault interruption (GFI) functions comprises the steps of measuring a first current in a first conductor, measuring a second current in a second conductor, producing a first digital representation of the measured first current, producing a second digital representation of the measured second current, calculating a differential between the first and the second digital representations, and interrupting current through at least one of the conductors in the event that the differential exceeds a predefined level.
[0011] These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a block diagram of a GFI-protected power distribution system in accordance with the present invention;
[0013] FIG. 2 is a block diagram of a portion of the system of FIG. 1 in accordance with the present invention; and
[0014] FIG. 3 is a flow chart of a method providing ground fault interruption functionality in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The following detailed description is of the best currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.
[0016] Broadly, the present invention may be useful in providing ground fault protection in a power distribution system. More particularly, the present invention may provide accurate ground fault protection in multi-phase power distribution systems. The present invention may be particularly useful in aerospace vehicles.
[0017] In contrast to prior-art ground fault interruption (GFI) systems, among other things, the present invention may provide light weight, non-complex and accurate GFI functionality. The present invention, instead of utilizing heavy current transformers and interconnecting circuitry, may provide GFI functions incorporated as an ancillary feature of a power distribution control line-replaceable-module (LRM) that may otherwise already be incorporated into a design of the vehicle. Consequently, the inventive system for performing GFI functions may be introduced into an aerospace vehicle while adding virtually no weight to the vehicle. Additionally, because the inventive GFI system is based on digital signals processors (DSP's). GFI functionality may be provided with trip level accuracies that exceed those of the prior art.
[0018] Referring now to FIG. 1 , there is shown a system for providing ground fault interruption (GFI) protection for a power distribution control system 10 . The power distribution control system 10 may be a solid state power control (hereinafter SSPC 10 ). The SSPC 10 may be incorporated into a Line Replaceable Module (hereinafter LRM) 11 that may be employed on an aerospace vehicle for power distribution control. The SSPC 10 may comprise power switches 12 , 14 and 16 . The switches 12 , 14 and 16 may comprise conventional solid state switching devices such as metal oxide field effect transistors (MOSFET's). The power switches 12 , 14 and 16 may be positioned to interrupt current in conductors or power feeders 18 , 20 and 22 , respectively. The power feeders 18 , 20 and 22 may be interconnected, through current feedback sensors 24 , to trip engines 26 , 28 and 30 respectively. A processor such as a supervisory control unit 32 may interconnected to the trip engines 26 , 28 , and 30 through galvanic interfaces 34 and synchronization pulse interfaces 36 . Each of the power feeders 18 , 20 and 22 may comprise one phase of a multi-phase power distribution system.
[0019] In the exemplary configuration of FIG. 1 , the power feeders 18 , 20 and 22 may be interconnected to power loads 40 , 42 and 44 . One of the power loads, the power load 42 as an example, is illustrated, symbolically, with a leakage path 46 going to ground. For purposes of illustration the present invention is described in the context of the leakage path 46 developing between ground and the power load 42 .
[0020] In operation, the trip engines 26 , 28 , and 30 may periodically perform sampling operations and acquire instantaneous current readings from the current feedback sensors 24 . The sampling operations may be performed at intervals of 1 milliseconds (msec) to 5 msec between each sampling operation. The trip engines 26 - 30 may then transmit a digital representation of the current reading to the supervisory control unit 32 . The supervisory control unit 32 may then perform a current sum calculation. A fault may be declared when current differential between phases (a so-called sum error) exceeds a predefined limit for a predefined period of time. Typically, such a sum error may be found when ground leakage current develops between one of the loads 40 , 42 or 44 and ground and when such leakage current continues for two or more of the periodic sampling operations of the trip engines 26 , 28 and 30 .
[0021] In the event of a fault declaration, the supervisory control unit 32 may produce a current interruption signal and transmit the signal to the trip engines 26 , 28 and 30 . The signaled trip engines 26 , 28 and 30 may then produce switch-off signals for transmission to their respective power switches 12 , 14 and 16 . The power switches 12 , 14 and 16 may then interrupt current flowing through the power feeders 18 , 20 and 22 .
[0022] Referring now to FIG. 2 there is shown a drawing of one of the trip engines, in an exemplary case, the trip engine 28 . The trip engine 28 is described herein in its role as providing GFI protection. It should be noted that the trip engine 28 need not be dedicated exclusively to GFI functionality. The trip engine 28 may also perform other power control tasks of the SPPC 10 . For example, the trip engine 28 may perform a circuit breaker function (not described herein) or a contactor control function (not described herein) in addition to the GFI function which is presently being considered herein.
[0023] The trip engine 28 may comprise a DSP 50 and one or more current processing blocks 52 and 54 which are tuned to process differing ranges of currents. The current processing blocks 52 and 54 may be interconnected with the DSP 50 through analog to digital (A/D) converters 50 a . The current processing blocks 52 and 54 may be interconnected with a current sensing resistor 56 of one of the current sensors 24 .
[0024] The current processing block 52 may be tuned to process current feedback in a range of zero to nominal current. For example, if the SSPC 10 is set with a 15 ampere (A.) range, the current processing block 52 might be tuned to process currents up to 10% greater than 15 A. The current processing block 54 may be configured to process current that may be higher than nominal. For example, if the SSPC 10 is set with a maximum trip rating of 1000%, then the current processing block 54 may be tuned to process currents up to 1000% of 15 A or 150 A. Tuning as described above may be accomplished by constructing the current processing blocks 52 and 54 with components which are selected for particular current ranges in a manner familiar to those skilled in the art of power distribution control.
[0025] Referring back now to FIG. 1 , the utility of the synchronization pulse interfaces 36 may be better understood. The supervisory control unit 32 may be interconnected with the trip engines 26 , 28 and 30 through the synchronization pulse interfaces 36 . Because of this interconnection the supervisory control unit 32 may provide a synchronization pulse through one of the synchronization pulse interfaces 36 to each of the trip engines 26 , 28 , and 30 . Upon receiving the synchronization pulse, each of the trip engines 26 , 28 , and 30 may acquire instantaneous readings of current feedback from their respective power feeders 18 , 20 and 22 .
[0026] The trip engines 26 , 28 and 30 may then transmit the digital representations of their respective current readings to the supervisory control unit 32 . The supervisory control unit 32 may then perform conventional current sum calculations based on these digital representations to determine if a ground fault should be declared.
[0027] Because instantaneous readings of current may be made periodically on a sampling basis, current sum calculations may be prone to certain inaccuracy. This inaccuracy may result if phase differential is allowed to develop between samplings of current. Synchronization pulses reduce such inaccuracy by providing timing coordination between all of the trip engines 26 , 28 and 30 .
[0028] If each of the trip engines 26 , 28 and 30 were to sample current based on its own independent timing, the current samplings might be performed at slightly different times. If the trip engine 26 , for example, sampled current at a time (T 0 ) different from a sampling time (T 1 ) of trip engine 28 , there may a change in phase angle of the power transmitted within the power feeders 18 and 20 during the time interval T 0 minus T 1 . Consider for example, a 50 microsecond (μsec) time differential that may be experienced between current samplings. At 400 Hertz (Hz) this time differential may correspond to a phase differential of 7 degrees. This may translate to an error of 1% in the current sum calculation. At 10 A of phase current, the 1% error may correspond to 100 milliamp (mA.). A 100 mA error may be unsuitable for many aerospace vehicle applications.
[0029] If a phase differential error of 100 mA were to develop as described above, GFI functionality would need to be withheld for any current differential lower than 100 mA. In other words, any ground-fault induced current differential lower than 100 mA would need to be treated as not representative of a ground fault event. Thus an actual ground fault event that produced a current differential of 75 mA would not trigger a current interruption action in this example.
[0030] A modest reduction of magnitude of such an error may be provided by increasing sampling rate but this may produce an intolerable processing load. A more desirable way of reducing this error is through a synchronization scheme of the present invention.
[0031] The supervisory control unit 32 may emit simultaneous synchronization pulses to each of the trip engines 26 , 28 and 30 . The synchronization pulses may provide commands to the trip engines 26 , 28 and 30 to sample current in their respective power feeders 18 , 20 and 22 . This may assure that sampling from all phases is performed virtually simultaneously. The time differences between current samplings by the trip engines 26 , 28 and 30 may be reduced to an interval of 500 ns to 1000 ns. This corresponds to an error of 0.07 degrees or a 0.0008% error. At 10 A, this is only 0.1 mA error. In this inventive synchronization pulse mode of operation, GFI functionality may be allowed to proceed for any current differential greater than 0.1 mA.
[0032] A further improvement in operational accuracy of the trip engines 26 , 28 and 30 may be achieved by individually calibrating each of the DSP's 50 against a known resistance at the time that the LRM's 10 are manufactured. A calculated gain may be determined for each individual DSP 50 and stored in a conventional non-volatile memory (not shown) within the individual DSP 50 . In this way, compensation may be made for any physical variations of one of the DSP's 50 as compared to any of the other DSP's 50 .
[0033] In one embodiment of the present invention, a method is provided for GFI functions, for example, on an aerospace vehicle. In that regard, the method may be understood by referring to FIG. 3 . In FIG. 3 , a flow chart portrays various aspects of an inventive method 300 . In a step 302 , current in a first power feeder (e.g. the power feeder 18 ) may be instantaneously measured (e.g., by use of one of the feedback sensors 24 and the trip engine 26 ). In a step 304 , current in a second power feeder (e.g. the power feeder 20 ) may be simultaneously measured (e.g., by use of one of the feedback sensors 24 and the trip engine 28 ). In a step 306 , a digital representation of the current in the first power feeder may be produced (e.g. in the A/D converter 50 a ). In step 308 , a digital representation of the current in the second power feeder may be produced in the same manner as step 306 . In a step 310 , the digital current representations may be transmitted (e.g. from the A/D converter 50 a ) to a processor (e.g. the supervisory control unit 32 ). In a step 312 , a calculation may be performed (e.g. in the supervisory processor 32 ) to determine a differential between the digital representations of currents in the first and second power feeders.
[0034] In the event that the differential calculated in step 312 exceeds a predefined level for a predetermined time interval, a step 316 may be initiated by which power transmission to a load through the first and second power feeders may be interrupted (e.g. by operation of the trip engines 26 and 28 and the power switches 12 and 14 ). In the event that the calculated differential is below the predefined level or does not continue beyond the predetermined time, the interruption step 316 may not be performed. In that case, a step 318 may be performed in which synchronization pulses may be generated and transmitted to trigger operation of steps 302 and 304 in which the trip engines may perform current sampling.
[0035] It should be noted that the step 318 may be performed by generating a separate synchronization pulse for each of the trip engines. In this way current differential error associated with phase differential may be substantially reduced as described hereinabove.
[0036] It should also be noted that the foregoing description of the method 300 discusses an exemplary collection of only two power feeders. It should be clear to those skilled in the art that the method 300 may be practiced with any number of power feeders and that current differentials among any combinations of power feeders may be used to trigger GFI functions
[0037] It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.
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A ground fault interruption (GFI) system is incorporated onto a DSP based LRM of an aerospace vehicle. The GFI system operates with digital controls and, unlike the prior art, the system does not employ current transformers. Synchronization pulses are employed to coordinate instantaneous current measurement samplings in each phase of a multi-phase power system. Coordinated sampling may reduce phase angle current differential errors and improve operational precision of the GFI system.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C. 119(e) of U.S. provisional patent application number 60/411,321 entitled Double Acting Load Floor Slam Latch.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a latch for securing together a panel in a frame to a keeper and provides for the opening and closing of a portion of the panel while allowing the remaining portion of the panel to remain closed. The latch can be repeatedly latched and unlatched by a user who desires to fasten and unfasten the entire panel or a portion of the panel which is adjacent the keeper.
[0003] Various latches are known for securing a panel to a keeper. One drawback with the previous latches is that the latches did not provide for the ability to secure only a portion of a panel in a frame and therefore provide the user with the ability to open and close only a portion of the panel which is divided into portions.
[0004] A need exists for a latch which can provide an improvement over the prior art in that it will be less costly to produce and less time-consuming to assemble, as well as providing slam-action latching ability when a portion of the panel is unfastened from a frame and the main pawl is in the closed position.
[0005] A further need exists for a latch which can be slammed shut to close from an open state when the panel is not fastened to the keeper by the latch.
[0006] In addition, load floor latches, which is one application for the latches of the present invention, are commonly used in the automotive industry. Often, these latches are employed to secure the contents of a compartment in a cargo area. The latch of the present invention can be used in compartments and bins in various locations such as glove compartments and storage areas in vehicles. For example, load floor latches find use for securing a floor panel, such as the panel which regulates access to vehicle items, such as spare tires, tools, jacks, batteries, and the like. In many cases, the floor panel is provided on the floor of a passenger vehicle or cargo compartment. The latch therefore must be durable, and it is desirable that the latch be able to withstand substantial force loads, such as those of the type generally encountered by bumps, rough terrain, and especially vehicular accidents, such as crashes, or rollover situations. It is important that compartment contents remain secured in the event of a vehicle crash or rollover. This is especially more important where the cargo compartment is located in the same general area as the vehicle operator, or other passengers. For example, in station wagon type vehicles, the cargo space for passengers and items of cargo is the same. Thus, in this type of vehicle, there is great danger to be encountered should a rollover of the vehicle occur and the latch becomes unsecured. If this were to happen, the compartment contents would spill out into the passenger compartment, thereby placing the vehicle operator in danger. A need exists for a load floor latch which has improved abilities to withstand a rollover, and facilitate latching of a panel, even under high stress conditions. It is also important that the latch, in addition to being durable, be easy to construct and install.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to a latch for securing a panel in a frame to a keeper and provides for the opening and closing of a portion of the panel while allowing the remaining portion of that panel to remain closed. A user can open the entire panel or a predetermined portion of the panel. The panel can be a door or load floor panel and the keeper can be provided in a vehicle subframe.
[0008] In accordance with the present invention, it is an object to provide a latch for securing together a panel to a keeper thus permitting opening and closing of a portion of the panel while allowing the remaining portion of the panel to remain closed.
[0009] When the latch is unlatched from a keeper, a user can refasten the panel by lowering the panel until the main pawl and the keeper are fastened together by the action of the keeper on the pawl of the latch. The latch also provides for the opening and closing of a portion of one of the panels while allowing the remaining portion of that panel to remain closed.
[0010] The present invention in one embodiment comprises a housing, a handle and a rocker mounted in the housing, a main pawl, a secondary side pawl and a main pawl spring. The main pawl of the latch is configured to be positioned in a panel and thereby secure the panel in a frame. The main pawl extends through the frame and when the latch is in the closed position, the main pawl is secured to the keeper. The secondary side pawl is provided such that it secures only a portion of the panel to the frame. To place the entire panel in an open position, the secondary side pawl is placed into a locked and closed position and the secondary side pawl engages the frame. To open only a defined portion of the panel the secondary side pawl must be in the open position such that the secondary side pawl clears the frame when that portion of the panel is opened. To open either the entire panel or only a portion of the panel, the handle is opened by a user and the handle actuates the main pawl and releases the panel from the load floor. A biasing means provides a biasing force on the main pawl such that when the user desires that the panel be closed such that the main pawl engages the keeper and the panel is secured, the panel can be lowered and a force applied to an outer face of the panel causes the main pawl to contact the keeper. A linear force on the pawl results in the direction of the rear of the housing and the main pawl slides back into the housing. The main pawl can now move back into a position such that the main pawl fastens the panel in a closed position. The handle can be provided with a biasing means in order to minimize undesired movement of the handle which may cause rattling when the handle is in an at rest position.
[0011] The inwardly facing side of the rocker is provided with two plungers each of which is inside a tower. The plungers compress back into the towers due to interference with a detent device on the inside of the housing which the plungers face. This creates a detent effect similar to that of a light switch and provides for an open and a closed position of the rocker. A user can rotate the rocker which in turn activates the secondary side pawl.
[0012] Another object of the invention is to provide a latch which allows a panel to be fastened by a slam action. This is accomplished by the shape of the pawl which interacts with the keeper.
[0013] Another object of the present invention is to accomplish the above objects by providing a spring-biased latch which can be closed by slam-action.
[0014] Another object of the present invention is to provide a latch which can be used in connection with panels of vehicles to regulate access to and from an area or compartment, such as, for example, a floor panel and a floor storage compartment.
[0015] Another object of the present invention is to provide a latch which has improved retention characteristics under stress forces, such as those experienced by vehicle rollovers and crashes.
[0016] These and other objects of the present invention will be more readily apparent when taken into consideration with the following description and the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] [0017]FIG. 1 is a perspective view of a preferred embodiment of a latch in accordance with the present invention showing the main pawl and secondary side pawl in the closed position.
[0018] [0018]FIG. 2 is a perspective view of the latch of FIG. 1 with the main pawl in the open position.
[0019] [0019]FIG. 3 is a perspective view of the latch of FIG. 1 showing actuation of the main pawl.
[0020] [0020]FIG. 4 is a perspective view of the bottom of the latch of FIG. 1 showing the main pawl and secondary side pawl in the closed position.
[0021] [0021]FIG. 5 is a perspective view of a latch of FIG. 1 provided in a front portion of a panel in a frame wherein the front portion and rear portion of the panel are open.
[0022] [0022]FIG. 6 is a perspective view of a latch of FIG. 1 provided in a front portion of a panel in a frame wherein only the front portion of the panel is open.
[0023] [0023]FIG. 7 is a sectional view of a side of the latch of FIG. 1 showing the main pawl in the open position.
[0024] [0024]FIG. 8 is a sectional view of a side of the latch of FIG. 1 showing the main pawl during actuation of the main pawl.
[0025] [0025]FIG. 9 is a sectional view of a side of the latch of FIG. 1 showing the main pawl in the closed position.
[0026] [0026]FIG. 10 is a sectional view of a side of the latch of FIG. 1 showing the rocker when the secondary pawl is in the open position.
[0027] [0027]FIG. 11 is a sectional view of a side of the latch of FIG. 1 showing the rocker during actuation of the secondary side pawl.
[0028] [0028]FIG. 12 is a sectional view of a side of the latch of FIG. 1 showing the rocker when the secondary side pawl is in the closed position.
[0029] [0029]FIG. 13 is a perspective view of the latch of FIG. 1 provided in a front portion of a panel in a frame wherein the front portion and rear portion of the panel are closed.
[0030] [0030]FIG. 14 is a perspective view of the latch of FIG. 1 provided in a front portion of a panel in a frame wherein the front portion of the panel is closed.
[0031] [0031]FIG. 15 is a sectional view of a side of the latch of FIG. 1 showing the rocker when the secondary pawl is in the open position.
[0032] [0032]FIG. 16 is a sectional view of a side of the latch of FIG. 1 showing the rocker during actuation of the secondary side pawl.
[0033] [0033]FIG. 17 is a sectional view of a side of the latch of FIG. 1 showing the rocker when the secondary side pawl is in the closed position.
[0034] [0034]FIG. 18 is a top view of the latch of FIG. 1 showing the main pawl in the closed position.
[0035] [0035]FIG. 19 is a side view of the latch of FIG. 1 showing the main pawl in the closed position.
[0036] [0036]FIG. 20 is a side view of the latch of FIG. 1 showing the main pawl in the closed position.
[0037] [0037]FIG. 21 is a front view of the latch of FIG. 1 showing the main pawl in the closed position.
[0038] [0038]FIG. 22 is a top view of the latch of FIG. 1 showing the main pawl in the closed position.
[0039] [0039]FIG. 23 is a rear view of the latch of FIG. 1 showing the main pawl in the closed position.
[0040] [0040]FIG. 24 is a top view of the housing of the latch of FIG. 1.
[0041] [0041]FIG. 25 is a side view of the housing of the latch of FIG. 1.
[0042] [0042]FIG. 26 is a side view of the housing of the latch of FIG. 1.
[0043] [0043]FIG. 27 is a rear view of the housing of the latch of FIG. 1.
[0044] [0044]FIG. 28 is a perspective view of the top of the housing of the latch of FIG. 1.
[0045] [0045]FIG. 29 is a view of the bottom of the housing of the latch of FIG. 1.
[0046] [0046]FIG. 30 is a perspective view of the bottom of a handle of the latch of FIG. 1 showing an actuator.
[0047] [0047]FIG. 31 is a top view of the handle of the latch of FIG. 1.
[0048] [0048]FIG. 32 is a view of the bottom of the handle of the latch of FIG. 1 showing an actuator.
[0049] [0049]FIG. 33 is a front view of the handle of the latch of FIG. 1.
[0050] [0050]FIG. 34 is a rear view of the handle of the latch of FIG. 1.
[0051] [0051]FIG. 35 is a side view of the handle of the latch of FIG. 1.
[0052] [0052]FIG. 36 is a rear view of the rocker of the latch of FIG. 1.
[0053] [0053]FIG. 37 is a top view of the rocker of the latch of FIG. 1.
[0054] [0054]FIG. 38 is a side view of the rocker of the latch of FIG. 1.
[0055] [0055]FIG. 39 is a side view of the rocker of the latch of FIG. 1.
[0056] [0056]FIG. 40 is a front view of the rocker of the latch of FIG. 1.
[0057] [0057]FIG. 41 is a bottom view of the rocker of the latch of FIG. 1.
[0058] [0058]FIG. 42 is a perspective view of the top of the main pawl of the latch of FIG. 1.
[0059] [0059]FIG. 43 is a top view of the main pawl of the latch of FIG. 1.
[0060] [0060]FIG. 44 is a side view of the main pawl of the latch of FIG. 1.
[0061] [0061]FIG. 45 is a side view of the main pawl of the latch of FIG. 1.
[0062] [0062]FIG. 46 is a top view of the main pawl of the latch of FIG. 1.
[0063] [0063]FIG. 47 is a rear view of the main pawl of the latch of FIG. 1.
[0064] [0064]FIG. 48 is a top view of the secondary side pawl of the latch of FIG. 1.
[0065] [0065]FIG. 49 is a side view of the secondary side pawl of the latch of FIG. 1.
[0066] [0066]FIG. 50 is a side view of the secondary side pawl of the latch of FIG. 1.
[0067] [0067]FIG. 51 is a front view of the secondary side pawl of the latch of FIG. 1.
[0068] [0068]FIG. 52 is a rear view of the secondary side pawl of the latch of FIG. 1.
[0069] [0069]FIG. 53 is a bottom view of the secondary side pawl of the latch of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0070] Referring now to the drawings in detail wherein like reference numerals indicate like elements through the several views, there is shown in FIG. 1- 4 , perspective views of a preferred embodiment of a latch 1 in accordance with the present invention with a housing 3 , handle 2 and rocker 6 . FIGS. 2 and 3 show the actuation of the main pawl 4 during rotation of handle 3 . As the handle 2 is rotated from the rest position shown in FIG. 1, the main pawl 4 moves toward the rear of the housing 3 thereby placing the main pawl 4 in the open position so that the main pawl 4 no longer protrudes from the housing 3 as shown in FIG. 2. Secondary side pawl 5 is shown protruding from housing 3 in the closed position in FIGS. 1 - 4 .
[0071] FIGS. 7 - 9 show the handle 2 of the latch 1 . The handle 2 features a handle actuator 9 which pivots or rotates with the handle 2 and contacts an interior face 25 of the main pawl 4 . As the main pawl 4 is pushed toward the rear of the housing 3 during movement of the handle 2 the main pawl 4 can be biased against a biasing means (not shown). The biasing means can be a spiral spring 14 mounted on a projection on a rear wall of the housing 3 .
[0072] FIGS. 10 - 12 and 15 - 17 show a rocker 6 of a preferred embodiment of the latch 1 of the present invention. The rocker 6 has two towers 7 each having a plunger 8 . The plungers 8 extend from the towers 7 and can move in the longitudinal direction of the towers 7 . A biasing force provided by a biasing device in the towers 7 is applied to the plungers 8 . As shown, a plunger spring 16 is the biasing device. The rocker 6 also has a rocker actuator 10 which acts upon secondary side pawl 5 . Rocker actuator 11 acts upon interior face 27 of the secondary side pawl 5 during movement of rocker actuator 10 as shown in FIGS. 15 - 17 .
[0073] Through the action of the main pawl 4 , the main pawl 4 can secure the panel 12 as a whole to the frame 13 as shown in FIG. 5 wherein access to a closure area 19 is obtained by the opening of the whole panel 12 . The secondary side pawl 5 is shown in FIG. 5 securing one half of the panel 12 to the frame 13 which is in turn supported by the main pawl 4 . The exterior face 26 of secondary side pawl 5 need not project entirely through the frame 13 in order to secure the panel front portion 17 . The panel rear portion 18 does not move due to the fixing device 21 which affixes panel rear portion 18 permanently to the frame 13 . Panel front portion 17 is free to move to an open position as shown in FIG. 6 by pivoting movement at hinge 15 as shown in FIG. 14.
[0074] To open the panel 12 as a whole the secondary side pawl 5 has to be in the locked and closed position. To open half of the panel 12 the secondary side pawl 5 has to be in the open position. Actuation in both cases is facilitated by opening the handle 2 which actuates the main pawl 4 and releases the panel 12 .
[0075] The following is a description of the unfastening of the panel 12 as a whole by disengagement of the main pawl 4 of the latch 1 from the keeper as shown in FIG. 5. With the panel 12 and the latch 1 in the closed position, the user can press the front of the closed handle 2 which can have a ribbed area 23 to assist in the gripping of the handle 2 to rotate the rear of the handle 2 up as to allow finger access. The user's hand can then be inserted into the handle 2 and it is rotated to its full extension. The handle actuator 9 hidden under the handle 2 acts in a rotational manner upon the handle 2 being rotated, contacting an interior face 25 of the main pawl 4 , creating a linear force to the rear of the latch 1 , sliding the main pawl 4 back into the housing 3 and compressing the main pawl spring 14 . The secondary side pawl 5 is still locked in the closed position securing the panel front portion 17 of the panel to the frame 13 which can be metal allowing the panel 12 and frame 13 to be opened as a whole. The main pawl 4 is now free from the keeper (not shown) which can be an internal subframe of a car which allows the panel 12 in the form of a loadfloor in the vehicle to be lifted and opened as a whole.
[0076] To close the panel 12 as a whole when the panel 12 is opened as a whole, the user must lower the panel 12 and press on a face of the panel 12 to actuate the ‘push to close’ main pawl design. Upon an exterior face 24 of the main pawl 4 contacting the keeper a linear force is created in the direction of the rear of the latch 1 . This forces the main pawl 4 back into the housing 3 , compressing the main pawl spring 14 , independently from the handle actuator 9 . Upon the panel 12 moving into the closed position the compressed main pawl spring 14 forces the main pawl 4 back out of the housing 3 to lock into the keeper which can be an internal metal subframe of a vehicle. The panel 12 as a whole is now locked in the closed position.
[0077] As shown in FIG. 6 and 14 , to open the panel front portion 17 independently of the panel rear portion 18 as shown in FIG. 6 and 14 , when the main pawl 4 and secondary side pawl 5 of the latch 1 is in the closed position, the user must press the rocker 6 to an open position thereby actuating the secondary side pawl 5 . As shown in FIGS. 10 - 12 and 15 - 17 , the rocker 6 rotates and a rocker actuator 10 underneath the rocker 6 acts in a rotational manner to contact an interior face 27 of the secondary side pawl, creating a linear force to the rear of the latch 1 sliding the secondary side pawl 5 back into the housing 3 . Preferably, full rotation of the rocker 6 occurs in 16 degrees. From the outset of rotation there are two plungers 8 , contained within two towers 7 underneath the rocker 6 which compress plungers 8 back into their towers due to interference with the inside of the housing 3 at a detent device 20 which the plungers 8 face. Preferably, full compression of the plungers 8 occurs at the mid point of rotation (8 degrees) and full extension of the plungers 8 occurs at the start and the end of rotation (0 and 16 degrees). This creates a detent effect similar to that of a conventional light switch. This switch effect also creates the detent for the open and closed positions.
[0078] After the secondary side pawl 5 is rotated back clear of the frame as described above, the secondary side pawl 5 is now in the open position and is clear of frame 13 . To allow the front section of the hinged panel front portion 17 to open independently of the panel rear portion and away from the frame, the user presses the front of the closed handle 2 which can have a ribbed area 23 to rotate the rear of the handle 2 up preferably to allow finger access. The hand is then inserted into the handle 2 and the handle 2 is rotated to its full extension. The handle actuator 9 under the handle 2 acts in a rotational manner upon the handle 2 being rotated, thereby contacting an interior face 25 of the main pawl 4 , creating a linear force to the rear of the latch 1 , sliding the main pawl 4 back into the housing 3 and compressing the main pawl spring 14 . The main pawl 4 is now free from the keeper allowing the panel front portion 17 of the panel 12 to open independently from the panel rear portion 18 .
[0079] To close the panel front portion 17 from the open position the user must lower the panel front portion 17 and cause a force to act upon a face of the panel front portion 17 to actuate the ‘push to close’ main pawl design. Upon the main pawl 4 contacting the keeper a linear force is created in the direction of the rear of the latch 1 . This forces the main pawl 4 back into the housing 3 , compressing the main pawl spring 14 , independently from the handle actuator 9 . Upon the panel 12 moving into the closed position the compressed main pawl spring 14 forces the main pawl 4 back out of the housing 3 to lock into the keeper (not shown). The panel front portion of the panel is now locked in the closed position.
[0080] To lock the panel front portion 17 into the frame 13 the user must press the rocker 6 to the closed position actuating the secondary side pawl 5 . The rocker 6 rotates and the rocker actuator 10 underneath the rocker 6 acts upon the rocker actuator 10 in a rotational manner contacting an internal face 27 of the secondary side pawl 5 , creating a linear force to the front of the latch 1 and sliding the secondary side pawl 5 back into the frame 13 . Preferably, full rotation of the rocker 6 occurs in 16 degrees. From the outset of rotation there are two plungers 8 , contained within two towers 7 underneath the rocker 6 , that compress back into the towers 7 due to interference with the detent device 20 at the inside of the housing 3 which acts upon the plungers 8 . Preferably, full compression of the plungers 8 occurs at the mid point of rotation (8 degrees) and full extension of the plungers 8 occurs at the start and the end of rotation (0 and 16 degrees). This creates the detent to retain the secondary side pawl 5 in the closed position. The panel 12 is now locked in the closed position.
[0081] The keeper described above can be a member having an aperture in a vehicle subframe. The frame described above can be metal or plastic not to the exclusion of other materials.
[0082] It will be recognized by those skilled in the art that changes may be made by the above-described embodiments of the invention without departing from the broad inventive concepts thereof. For example, each of the features described above do not all need to be included in a single device. Rather, one or more features can be provided in a single device where desired and in any combination. It is understood, therefore, that this invention is not limited to the particular embodiment disclosed, but it is intended to cover all modifications which are within the scope and spirit of the invention.
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The present invention relates to a latch for securing together a panel to a keeper thus permitting opening and closing of a portion of the panel while allowing the remaining portion of the panel to remain closed. When the latch is unlatched from a keeper, a user can refasten the panel by lowering the panel until the main pawl and the keeper are fastened together by the action of the keeper on the pawl of the latch. The latch also provides for the opening and closing of a portion of one of the panels while allowing the remaining portion of that panel to remain closed.
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CROSS-REFERENCES TO RELATED APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
The invention relates to a catheter for the ablation of biological, in particular of animal or human, tissue, preferably for the ablation or mapping electrode, characterized in that the at least one ablation or mapping electrode has a reduced number of electrical interference centers that generate microscopic electric potential differences, field strength maxima or microscopically different reaction capabilities at the electrode surface, a method for treating catheters, and an apparatus for carrying out the treatment of catheters.
TECHNICAL FIELD
One of the main aims in the catheter ablation of myocardial tissue is to interrupt, by lesions of the upper layers of the heart tissue, regions of the conduction system that can have a negative effect on the cardiac action. The success of a treatment depends, however, very substantially on whether the correct depth of lesion was achieved during the ablation. In this case, correct depth of lesion means in essence that the undesired regions disrupting the conduction system are removed, but that no further-reaching injuries are introduced. It is evident that with an excessively small depth of lesion the success of treatment is endangered, whereas in some circumstances an excessively large depth produces very many relatively severe side effects. Since there are vessel walls running in the heart which may not be unnecessarily damaged, and also the tissue to be ablated is frequently only of a limited thickness, in the event of excessively large depths of the lesions it is even possible for lethal accidents to occur because of severed heart walls or heart vessels. An attempt has therefore been made in the case of conventional ablation methods to estimate the optimum depth of lesion by the synchronous recording of ECG signals on the occurrence of success in treatment. However, in this case the irradiated high-frequency energy was exceptionally detrimental to the recording of these signals, and an attempt was undertaken to mitigate such influences by means of appropriate electrical or electronic filters in the downstream equipment. However these attempts had only limited success, or none. Producing the irradiated power led to extremely long treatment times which are in the range of several hours and in this case both subject the patient to substantial stress and are unable to reliably prevent slippage of the ablation catheter. Furthermore, lesion is no longer possible starting from a specific power, since the temperature generated no longer suffices for tissue coagulation.
SUMMARY OF THE INVENTION
It is therefore the object of the invention to permit the recording of ECG signals during catheter ablation and, in particular, to improve the quality of the recorded ECG signals to such an extent as to permit medical statements with reference to cardiac action.
This object is achieved by the invention in an exceptionally surprising way with the aid of a catheter for the ablation of biological, in particular of animal or human, tissue, including ablation of human myocardial tissue, said catheter comprising: at least one ablation or mapping electrode, wherein the at least one ablation or mapping electrode has a reduced number of electrical interference centres which generate microscopic electric potential differences, field strength maxima or microscopically different reaction capabilities at the electrode surface and wherein the at least one ablation or mapping electrode has an electrolytically treated surface. This object is also achieved by a method for producing a catheter with improved electrical properties, the method comprising the following steps:
providing a catheter which comprises at least one ablation or mapping electrode,
providing a vessel with a solution which contains ions whose motion can be influenced by an electrical field,
immersing the at least one ablation or mapping electrode in the solution,
providing a further electrode in contact with the solution,
treating the at least one ablation or mapping electrode, by applying an electric voltage between the ablation or mapping electrode.
This object is also achieved by Apparatus for catheter treatment, comprising:
a vessel for holding an electrolytic solution and regions of the catheter,
an electrolytic solution in the vessel, wherein the ablation or mapping electrode and the further electrode can be wetted by the electrolyte during conducting of the catheter treatment,
a voltage-generating or current-generating unit, and
connection device for connecting at least one ablation or mapping electrode of the catheter and a further electrode to the voltage-generating or current-generating unit.
The inventor surprisingly followed a completely different path than has previously been the case in the known prior art.
Instead of subjecting the recording equipment to change or an attempt at improvement, the cause of interference in the recording of the ECG signals were reduced or even completely eliminated.
The inventor was the first to find out that the cause of the electrical interference in the ECG recording during simultaneous irradiation of high-frequency energy essentially resides not in the leads to and from the catheter electrodes, not in the electronic recording devices and, in particular, not in their input filters, but in electrical interference centres in the region of the surface of the ablation or mapping electrodes.
This finding was all the more surprising since every investigated ablation catheter with platinum electrodes exhibited such electrical interference centres, and after their reduction or removal, essentially after their removal from the electrode surface, was virtually or completely free from the undesired interference previously described.
In accordance with the invention, in the case of a catheter for the ablation of biological, in particular animal or human, tissue, preferably for the ablation of human myocardial tissue, having at least one ablation or mapping electrode, this at least one ablation or mapping electrode has a reduced number of electrical interference centres. For example, this improves the disturbed ECG recordings illustrated in FIGS. 5 and 6 in such a way that the signals illustrated in FIG. 7 or 9 can be obtained. It was also established, surprisingly, that the ECG signals were substantially improved even without an applied high frequency, that is to say exhibited distinctly fewer interference signals.
In a particularly advantageous way, the electrical interference centres which generate electric signals during the output of high-frequency energy to the at least one ablation or mapping electrode and which are essentially arranged on surface regions of the at least one ablation or mapping electrode are reduced in their number, areal extent and/or electrical effect. This results in a removal or electrical deactivation of the influence of these interference centres.
A particularly effective method for achieving the above successes consists in that the at least one ablation or mapping electrode has an electrolytically treated surface. An electrolytic method for rounding small tubular medical articles is known from DE 196 28 879 A1. In this method, a cathodal pin of defined diameter is inserted into the cavity, and an electrical potential is generated by applying an electric current between the internal pin and one that is connected to the anode, electrolytic internal deburring at corners and edges being achieved by adding an electrically conducting electrolyte.
In the electrolytic treatment, that is to say a treatment with the aid of an electrolyte and an applied voltage or impressed current, it is particularly advantageous when the treatment is carried out with a solution containing halogen ions, in particular chlorine ions, because then it is possible to observe atomic rearrangement processes on the metal surface, in particular on the platinum surface, which lead to an altered surface structure which has the desired positive properties.
It was frequently to be observed after this treatment that structures of the surface of the at least one ablation or mapping electrode have a rounded surface structure whose edges have a radius of more than approximately 500 nm, preferably of more than 100 nm, but at least more than 10 nm, and it is suspected that these surface changes already cause at least a portion of the reduction in the electrical interference centres or their effects.
It could be established after the treatment, with the aid of optical investigations of the discolorations of a platinum ablation electrode surface, for example, that the at least one ablation or mapping electrode comprises a metal whose atoms are present at the surface in a fashion bound at least partially atomically or in an amorphous and essentially non-crystalline manner. It is assumed by virtue of this rearrangement or electrolytic deposition by galvanic deposition processes that electric potentials present at the surface are compensated, for example, by grain boundaries in the metal, which is present in crystalline form, and that after the treatment according to the invention it is possible to balance out even microscopic electric crystalline potential differences, regions with field strength maxima or microscopically different reactive capabilities at the electrode surface. This mitigates the phenomena occurring, for example, during the output of HF energy, which are ascribed without limitation of the generality or the scope of the invention to locally differing ionic mobility, the point being that there is no longer any “turning on” by more strongly bound or less mobile polar ions which would cause the formation of electric potentials that are superimposed on the ECG signal. The ions which now move virtually identically at all locations on the surface of the ablation or mapping electrode no longer generate local field strength differences and also no longer disturb the ECG recording.
It is therefore assumed that, when the catheter advantageously comprises a platinum ablation or mapping electrode, the surface of an ablation or mapping electrode is coated at least partially with elementary platinum. It is, however, also within the scope of the invention for such an atomic, essentially non-crystalline or amorphous coating also to be produced, for example, using electroplating deposition techniques or generally known techniques for coating or plating.
It then results in an advantageous way that the surface of the at least one ablation or mapping electrode comprises regions with deposited metal present essentially in an amorphous manner or atomically.
In the case of the method for producing a catheter with improved electrical properties, in the case of which method the catheter comprises at least one ablation or mapping electrode, the ablation or mapping electrode, of the catheter, that is to be treated is immersed in a solution which contains ions whose motion can be influenced by an electric field; this is advantageously achieved by virtue of the fact that an electric voltage which generates the motion of the ions is applied between the ablation or mapping electrode, of the catheter, that is to be treated and a further electrode in contact with the solution. The ions to be moved onto the catheter electrode surface strike there and, both with the aid of their electric fields and, for example, their dipole moment or energy potentials of the atomic or molecular electron cloud and their kinetic energy, create interactions at the metal surface which measurably give rise to the desired electrical consequences of the atomic rearrangement or deposition.
The method can be carried out with particular advantage when the solution contains NaCl in a range from 0.1 to 100 g/l. Furthermore, there is a particularly preferred range when the solution contains NaCl in an amount of approximately 7 g/l.
Depositions at the ablation or mapping electrode surface are achieved, for example, whenever the solution contains ions of a metal salt. Prior surface treatments, for example in the case of platinum-iridium catheters, have aimed at enlarging the surface, that is to say precisely to create structures that are not too smooth but rough, having a surface that is larger approximately by the factor 1000; however, the invention proceeds, with surprising success, precisely along the opposite path.
Good results are achieved with the aid of an applied AC voltage containing components which have a frequency of more than 0.01 Hz and less than 10 kHz. The particularly preferred frequency range extends from 1 to 100 Hz and is most strongly preferred to be at about 10 Hz.
Good results are achieved when the applied AC voltage is in a range from 0.1 to 100 V eff . The range most strongly preferred results when the applied AC voltage is at 3 to 7 V eff .
Instead of an applied voltage, it is also possible to impress an AC current which generates a voltage having the properties set forth above on the ablation or mapping electrode and the further electrode. The best results follow in this case when the AC voltage has, per ablation or mapping electrode, a current intensity of from about 1 mA eff to 1 A eff , preferably from 30 to 100 mA eff .
An advantageous apparatus for catheter treatment comprises a vessel for holding electrolytic solution and regions of the catheter as well as, during the conduct of the catheter treatment, an electrolytic solution, and a connection device for connecting at least one ablation or mapping electrode of the catheter and a further electrode to a voltage-generating or current-generating unit, in the case of which apparatus the ablation or mapping electrode and the further electrode can be wetted by the electrolyte during the conduct of the treatment.
In the case of a compact, transportable embodiment that can be used on site directly before treatment, the voltage-generating or current-generating unit is an internal unit mechanically connected to the vessel.
In the case of a cost-effective stationary apparatus, the voltage-generating or current-generating unit is an external unit not mechanically connected to the vessel, for example an external laboratory voltage generator.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in more detail below with the aid of preferred embodiments and with reference to the attached drawings, in which:
FIG. 1 shows a schematic illustration of an apparatus for treating ablation catheters,
FIG. 2 shows a schematic illustration of an apparatus for measuring simulated ECG signals with and without irradiated high-frequency energy,
FIG. 3 shows a simulated ECG signal, as mapping signal, before electrode treatment without applied high-frequency energy,
FIG. 4 shows a simulated ECG signal, as mapping signal, after electrode treatment without applied high-frequency energy,
FIG. 5 shows interference in the simulated ECG signal in the case of fast, non-pulsed power regulation of the output high-frequency energy for a non-treated ablation catheter,
FIG. 6 shows interference in the simulated ECG signal in the case of fast, pulsed power regulation of the output high-frequency energy for a non-treated, quadrupole ablation catheter with cylindrical platinum ablation electrodes each 4 mm long,
FIG. 7 shows a simulated ECG signal in the case of fast, non-pulsed power regulation of the output high-frequency energy for the quadrupole ablation catheter with cylindrical platinum ablation electrodes, each 4 mm long, from FIG. 6 after its treatment,
FIG. 8 shows interference in the simulated ECG signal in the case of fast, pulsed power regulation of the output high-frequency energy for a non-treated ablation catheter with a cylindrical platinum ablation electrode 4 mm long, and three further mapping electrodes,
FIG. 9 shows a simulated ECG signal in the case of fast, pulsed power regulation of the output high-frequency energy for the non-treated ablation catheter from FIG. 8 with a cylindrical platinum ablation electrode 4 mm long, and three further mapping electrodes after its treatment,
FIG. 10 shows an electron microscope photograph of the platinum surface of the ablation electrode of a non-treated ablation catheter with 1 960-fold magnification,
FIG. 11 shows an electron microscope photograph of the platinum surface of the ablation electrode of the non-treated ablation catheter from FIG. 10 with 6 160-fold magnification,
FIG. 12 shows an electron microscope photograph of the platinum surface of the ablation electrode of the ablation catheter from FIG. 10 with 2 040-fold magnification after its treatment,
FIG. 13 shows an electron microscope photograph of the platinum surface of the ablation electrode of the ablation catheter from FIG. 10 with 6 080-fold amplification after its treatment,
FIG. 14 shows an AFM (atomic force microscopic) or force microscopic plot of a surface region of size 10 times 10 μm of an untreated platinum ablation electrode, and
FIG. 15 shows an AFM or force microscopic plot of a surface region of size 10 times 10 μm of a treated platinum ablation electrode.
DETAILED DESCRIPTION OF THE INVENTION
The invention is described below in more detail and with reference to the attached drawings.
Reference is firstly made to FIG. 1 from there may be gathered a generator 1 , which is connected to a catheter 2 , and a vessel 3 filled with electrolyte.
In the example from FIG. 1 , the catheter is provided with at least one ablation or mapping electrode, which is connected to the generator 1 via a supply lead E 1 , and with a. further electrode, which is connected to the generator 1 via a supply lead E 2 . The further electrode can be a mapping or an ablation electrode.
Suitable as catheters for carrying out the invention are essentially all known ablation catheters, in particular catheters with platinum electrodes, and the following specified catheters, for example, were used successfully in the investigations of the inventor:
1. BARD SideWinder Catheter S/N: 17009000
2. BARD SideWinder Catheter S/N: 1300013000
3. Cordis Webster Catheter Internal S/N: CW1
4. Cardiac Pathways Catheter S/N: G709313
5. Biotronic Catheter: AlCath Twin (non-ablation catheter, fractal Pt/Ir surface)
6. BARD Stinger Distal Tip ablation catheter 4 mm Tip
8. BARD Stinger Distal Tip ablation catheter 8 mm Tip
9. Biotronic Catheter AlFractal, Distal Tip
10. Ablation catheter (fractal Pt/Ir surface)
Use was made as generator 1 of a conventional laboratory alternating current generator which could generate frequencies in the range from 0.01 Hz to 10 kHz. During the treatment of the catheter 1 , which had platinum electrodes in the present embodiment, voltages were applied in a frequency range from 1 to 100 Hz, preferably at 10 Hz, whose root-mean-square voltages were in a range from 0.1 to 100 V eff .
A particularly preferred range was from 1 to 10 V eff , and the most preferred AC voltage range was from 3 to 7 V eff . As alternative to the voltage generator, it was possible to use a current generator which was regulated in the range from 1 mA eff to 1 A eff , preferably in a range from 30 to 100 mA eff , this current intensity being applied per ablation or mapping electrode.
This voltage or this current was generated between the at least one ablation or mapping electrode of the catheter 2 and the further electrode, connected via the supply lead E 2 , or was generated between the electrode connected via the supply lead E 1 and a further electrode 4 in contact with the electrolytic solution 5 , the catheter 2 having been immersed with the electrodes to be treated in the electrolytic solution 5 .
These voltages or current intensities were applied over a current period of from approximately 1 second to several minutes, it being possible for measurements in the set-up illustrated in FIG. 2 to show that a saturation could be achieved in each case which was accompanied by the virtually complete disappearance of interference signals. Thereafter, further treatment no longer yielded noticeable advantages.
Furthermore, it was also possible to treat more than one ablation or mapping electrode at the same time, for example in the case of a catheter comprising four ablation electrodes in the case of which only the required current intensity rose, in order to produce the same positive effect in the same time period for a plurality of electrodes. It was possible in this case to apply voltages, or to impress currents, both to neighbouring catheter electrodes and to the further electrode 4 .
Use was made as electrolytic solution of a halogen-ion-containing solution which preferably contained chlorine ions and, in a way most preferred, an NaCl solution.
The concentration of an NaCl solution was in a range from 0.1 to 100 grams per liter and was preferably approximately 7 grams per liter, which corresponds approximately to a physiological sodium chloride solution. For lower concentrations, only longer treatment times resulted in conjunction with approximately equally good results.
The catheters were essentially left in the electrolytic solution 5 until the desired current-reducing value of the signal transmission quality referred to the ECG signal was yielded upon application of AC voltage at high frequency.
In order to check the result, use was made of the set-up illustrated in FIG. 2 , which included a vessel 6 which had a physiological NaCl solution and in which the catheter 2 was arranged in such a way that its ablation or mapping electrode was completely wetted by the NaCl solution, while the catheter 2 was also connected to a conventional high-frequency generator 7 which was used to feed the ablation electrode of the catheter 2 with the high-frequency energy values typical of ablation.
The HF field was generated by the HF generator 7 between the ablation electrode of the catheter 2 and a reference electrode 8 , and in this way represented to a very good approximation a situation such as also obtains in the human heart, for example.
An ECG simulator 9 was used to generate voltage signals which corresponded to a very good approximation to the electric voltages output by the human heart, both in terms of level and of their time profile.
The catheter 2 was also connected to a high-frequency filter 10 which filtered out the high-frequency signal components fed in by the HF generator 7 . Such filter arrangements are well known to the person skilled in the art and can correspond, for example, to the input filters used in the Quadra Pulse unit from AD Electronic.
The ECG signal obtained, as tapped from the catheter, in particular from its mapping electrode, or even its ablation electrode, was then fed to an ECG monitor 11 such as is marketed, for example, by Physiocontrol under the designation of LIFEPAK 10 or by Bard as EP-Laborsystem.
The results obtained are explained in more detail below with reference to FIGS. 3 to 9 .
As long as no high-frequency energy or high-frequency voltage was fed to the catheter electrodes, FIGS. 3 and 4 prove that the recording of the ECG signals could be undertaken virtually without interference.
However, if the level of the high-frequency voltage or the amount of irradiated high-frequency energy is regulated during the ECG recording, as is the case during a real ablation procedure on the patient, voltages arise which vary virtually linearly in proportion to the irradiated energy and are illustrated, for example, in FIG. 5 .
Regulation of the output energy in the course of a power regulation of the irradiated high-frequency energy therefore always leads to superimposition of interference signals on the ECG signals, which renders it impossible, as a rule, for the physician to make a statement on the success of treatment or the current condition of the heart.
Even more difficult is the situation in the case of pulsed power regulation, as illustrated in FIGS. 6 and 8 , in which figures it is virtually no longer possible to detect any components of the ECG signal at all.
The high-frequency power irradiated in the case of these experiments was from approximately 1 to 50 W, as is entirely normal for high-frequency catheter ablation in human hearts.
However, if an ablation catheter was treated in the way described above, it was possible in conjunction with the same experimental set-up to reduce the superimposed interference down to a value virtually no longer measurable, in any case by a factor of more than ten, as is illustrated, for example, in FIGS. 7 and 9 .
The ECG result illustrated in FIG. 7 corresponds essentially to the set-up and the respective values which lead in the case of an untreated catheter to the results shown in FIG. 5 , while the results illustrated in FIG. 9 , which were obtained with a catheter treated according to the invention, corresponded to those which were shown in FIGS. 6 and 8 for the untreated catheter.
The experimental set-up, identical per se in each case, which differed only in whether the catheter was used directly as marketed by the respective manufacturer or whether it was treated in the way according to the invention, proves the great success of the present invention unambiguously.
The catheters according to the invention therefore have on their electrode surfaces fewer electric or electronic interference centres which can generate the superimposed signals. The measure of the reduction in interference is therefore a measure of the presence or the reduced or diminished presence of such interference centres.
It is assumed without limitation of generality and without limiting the invention that the generation of such signals superimposed on the ECG signal is due to local adhesion sites or local extremes in the electric field strength on the surface of the catheter, at which ions or molecules of dipole moment can be bound with differing strength or accelerated, and can then, upon application of the HF voltage or HF energy, generate, because of the different mobility, a voltage signal which is superimposed on the ECG signal.
The electron microscope photographs illustrated in FIGS. 10 to 13 were obtained in order to provide proof of such behaviour: as in the case of FIGS. 10 and 11 , for example, they show that the catheter surface, initially sharp edged in the microstructure region, has soft roundings and fewer sharp ridges or furrows after the electrolytic treatment.
The mechanical smoothing alone can reduce the mechanical friction of the ions on the surface, thus diminishing interference centres brought about thereby which are mechanically caused but electrically active.
Furthermore, it was possible by optical investigations to prove the deposition or the presence of elementary platinum on the treated surface of the ablation or mapping electrode. This led to the assumption that crystalline grain boundaries or other suitable surface regions of the platinum, for example regions with sharp edges and high electric field strengths, are affected by the attack of the chlorine ions and platinum or metal atoms can be dissolved out. Platinum atoms can become detached from the metallic crystalline compound and be rearranged in an amorphous manner by the kinetic energy and/or the potentials of the electron cloud of the chlorine ions.
A virtual detachment, that is to say a migration in the bound state of the platinum atom, also results in release of the atom from the crystal compound, and its rearrangement.
The rounded tips of the treated surface, which are exposed to increased attack, can also be explained thereby, the point being that attack from several sides can take place precisely in these regions.
A further alternative explanation consists in that the halogen ions cause the ion milling known from the vacuum processing of semiconductors, in the case of which mechanical removal takes place at the surface.
The difference caused by the treatment also become very particularly clear on the force microscopic plots which show, for example in FIG. 14 , the untreated surface with pin-like extensions and sharp ridges and, in the case of the treated surface which is illustrated in FIG. 15 , a entirely smooth surface without pin-like extensions.
This migration of platinum atoms can also compensate potentials present at the surface, for example at grain boundaries, or field strength maxima in such a way that even the effective electrical influence of such solid-state potentials or field strength maxima can be drastically reduced.
It is therefore possible to reduce not only the areal extent of the electrical interference centres present before the treatment, but also their electrical effect.
The inventors also found out that in many cases associated with a treated catheter structures of the surface of the ablation or mapping electrode no longer have sharp edges, that is to say very small radii of curvature. In a surface section with a length, width or height of less than 10 μm, the edges present had a radius of more than approximately 10 to 50 μm.
Sharper edges or smaller radii are either regularly reduced in number or no longer occur at all. In accordance with the invention, most radii of curvature of the edges were more than approximately 500 nm, preferably more than 100 nm, but at least more than 10 nm.
It is also within the scope of the invention for metal salts to be dissolved instead of the halogen ions or in addition to the halogen-ion-containing electrolytic solution, in order in this way to achieve an electroplating amorphous deposition of metal atoms on the metallic ablation or mapping electrode.
It may be pointed out that catheters treated according to the invention exhibit a clearly improved signal quality, that is to say substantially smaller interference signals, even without applied high-frequency energy. This improvement is not limited to ablation electrodes, but can also be used successfully in the case of mapping electrodes or mapping catheters.
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In order in the case of a catheter for the ablation of biological, in particular of animal or human, tissue, preferably for the ablation of human myocardial tissue, having at least one ablation or mapping electrode to permit the recording of ECG signals during catheter ablation and, in particular, to improve the quality of the recorded ECG signals to such an extent as to permit medical statements with reference to cardiac action, it is provided that the at least one ablation or mapping electrode has a reduced number of electrical interference centres. Furthermore, the invention provides methods and apparatuses with the aid of which conventional catheters can be treated in such a way that these interference centres are reduced.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application Ser. No. 10/636,812 entitled “Putter,” filed on Aug. 8, 2003, now allowed, which is a continuation-in-part of U.S. patent application Ser. No. 10/051,007 entitled “Adjustable Putter,” filed on Jan. 22, 2002, now U.S. Pat. No. 6,663,497, which claims priority from Provisional Patent Application No. 60/263,709, filed Jan. 25, 2001. All of these documents are incorporated herein by reference in their entireties.
BACKGROUND OF THE INVENTION
[0002] 1. Field of The Invention
[0003] The invention relates to an improved golf club construction. More particularly, the invention is related to a putter with adjustable loft and weighting or a putter with a high moment of inertia.
[0004] 2. Description of the Related Art
[0005] The design of putters is typically viewed as a pursuit of an aesthetically pleasing club that promotes a golfer's confidence in his or her stroke. As such, many putters have been designed irrespective of the mechanics inherent in the putting swing. Furthermore, many putters lack a design that accounts for an individual golfer's characteristics and characteristic playing style (i.e., stance, grip, etc.).
[0006] The lack of attention to technical details in many putter designs results in clubs that are not aimed or balanced properly. Such technical considerations, for example, include heel and toe weight distribution, location of the putter head's center of gravity or “sweet spot,” putter length, shaft flexibility, grip, head weight and total club weight, loft, and lie. Because the USGA Rules of Golf permit significant latitude in the design of putters, i.e., the shaft, neck or socket of a putter may be fixed at any point in the head, many putter designs are possible. And, because significant deviation in the intended path of a putt can be experienced for even slightly off-center hits, careful attention to these design factors can result in a putter that is more likely to perform well in use.
[0007] Various adjustable club constructions are known. For example, U.S. Pat. No. 2,305,270 to Nilson discloses a golf club with a hosel that has an extension on which the head is slidably and pivotally mounted. The extension is embedded in a shallow depression in the back of the head and runs substantially the entire length of the head. The head further includes lugs with inner serrated portions, and when a desired angle has been selected for the face, serrated portions on the extension are engaged with the lugs to lock the position.
[0008] U.S. Pat. No. 4,778,180 to Guenther discloses a golf club having a reversible head for use either as a putter or chipper, and for use by either a left handed or right handed player. In operation, the head is rotatable by 180° on a pin to present either a chipper face or putter face. A lever with side cam surfaces permits releasable locking of the head in position.
[0009] U.S. Pat. No. 4,194,739 to Thompson discloses an adjustable golf putter with a body and a separate putter face that is initially adjustable relative to the body prior to permanent securement. The putter includes an elongated tapered body having a plane of symmetry extending in the direction of the putting motion. The face is rotatably mounted on the head about a pin, and a pair of screws secure the face to prevent rotation. A bubble level is also recessed in the putter face. If the putter face is not level, the golfer loosens the screws, pivots the putter face about the pin to adjust the angle between the upper surface of the putter face and the shaft, and when the bubble level indicates level for the preferred putting stance of the golfer, the screws are tightened. The weight of the putter head is adjustable by disposing cylindrical weight inserts in a bore in the body located behind and perpendicular to the face.
[0010] In addition, U.S. Pat. No. 4,067,572 to Coleman discloses a golf club with a hollow main body, thereby providing a chamber into which liquid or granular weighting material may be placed. The main body is preferably spherical, and a movable, disc-shaped face portion is provided on its rear with a portion that is contoured to complement the spherical shape of the body. A clamping member and retaining bolt are provided; loosening the bolt permits the club face portion to be repositioned through an arc of 360°, while tightening the bolt fixes the face portion in the desired position.
[0011] Despite these developments, there exists a need for an improved putter construction. In particular, there is a need for an improved putter with adjustable loft and weighting and there is a need for an improved putter with a high moment of inertia.
SUMMARY OF THE INVENTION
[0012] The present invention is related to a golf putter head adapted for attachment to a club shaft. The head includes a face member having a strike face and a cylindrical back cavity, and a body member configured to fit and rotate in at least one plane or direction within the back cavity. Selective rotation of the body member within the back cavity sets a loft of the putter head. In one embodiment, a weight member is coupled to the body member, and is symmetrically disposed about a longitudinal center of the body member. The weight member may have a generally arcuate shape and may be disposed on the back portion of the body member.
[0013] The back cavity of the face member may include two recessed wing portions and a recessed generally cylindrical portion disposed therebetween, while the body member may include a front portion with a generally cylindrical projecting portion and a cylindrical passage extending parallel therethrough. The front portion of the body member further includes opposing sections separated by a slit that extends along the length of the cylindrical passage, the opposing sections being connected by a threaded hole. Threadable engagement of a fastener in the threaded hole changes the separation of the opposing sections.
[0014] A generally cylindrical insert is configured and dimensioned to be received within the cylindrical passage of the body member, with the insert further including a base portion configured to be received in fixed orientation within the wing portions.
[0015] The body member may be generally rectangular and have a side flange with a bore therein, the bore being configured and dimensioned to receive the shaft. The body member also may include a front portion, a back portion, and a pair of sides, the sides each having a lower edge with at least two edge portions that are crooked with respect to each other at an angle of between about 0° and about 30°.
[0016] The present invention is further related to a golf putter head adapted for attachment to a club shaft. The putter head includes a face member having a strike face and a back cavity, the back cavity including at least one keyway portion, and a body member configured to fit and rotate in at least one plane or direction within the back cavity, the body member including a passage therein. In addition, the putter head includes an insert configured to fit and rotate in at least one plane or direction within the passage, the insert including at least one keyed portion. When the keyed portion is disposed in the keyway portion, selective rotation of the body member about the insert sets a loft of the putter head.
[0017] The present invention is also related to a golf putter head, adapted for attachment to a club shaft, having a high moment of inertia. The putter head comprises a face member, a body member, and a weight member. The face member has a strike face and a rear surface opposite the strike face. The body member has a first end and a second end. The body member first end is coupled to the face member rear surface. The weight member is coupled to the body member second end.
[0018] The weight member has a first weight, and the club head has a second weight. The first weight is preferably at least 25% of the second weight. More preferably, the first weight is at least 50% or 75% of the second weight. The weight member may be curved toward said face member, and ends of the weight member are from 0 inch to approximately 1.5 inches from the strike face. Alternatively, the ends of the weight member may contact the face member.
[0019] The putter head contains a shaft mount for connecting a shaft to the club head. The shaft mount preferably is offset from the face member such that the shaft attaches close to the club head center of gravity. The body member preferably comprises the shaft mount, either coupled thereto or as an integral part thereof. The shaft may be bent to give it a straight, no offset appearance at address. The shaft mount is preferably positioned a distance of approximately 1.5 inches to approximately 2 inches from the strike face. Alternatively, the shaft mount is preferably positioned between the midpoint of the putter head length and the strike face, and more preferably is positioned a distance of approximately 25% of the putter head length to approximately 50% of the putter head length behind the strike face. The club head center of gravity is preferably located a distance of approximately 1 inch to 4 inches from the strike face. More preferably the center of gravity is approximately 1.5 inches to approximately 2 inches from the strike face, and most preferably approximately 1.7 inches from the strike face. Alternatively, the center of gravity is preferably located between the midpoint of the club head length and the weight member. Alternatively, the center of gravity is located a distance of approximately 50% of the club head length to approximately 75% of the club head length behind the strike face.
[0020] The body member preferably is coupled to the face member in a substantially perpendicular fashion such that the putter has a “T-frame” shape. The face member preferably is coupled to the body member such that the face member is lower than the body member. This will help reduce grounding of the club during the swing. The face member leading edge may be beveled for the same reason. The club head is balanced such that it is stable when placed on a substantially flat surface.
[0021] A measure of the putter head moment of inertia about a vertical axis passing through the club head center of gravity preferably is greater than approximately 550 kg·mm 2 . More preferably, the moment of inertia is within a range of approximately 600 kg·mm 2 to approximately 800 kg·mm 2 , and most preferably is within a range of approximately 700 kg·mm 2 to approximately 750 kg·mm 2 .
[0022] The moment of inertia of the club head as measured about a vertical axis passing through the shaft mount preferably is greater than approximately 550 kg·mm 2 . More preferably, the moment of inertia is within a range of approximately 600 kg·mm 2 to approximately 900 kg·mm 2 , and most preferably is within a range of approximately 800 kg·mm 2 to approximately 850 kg·mm 2 .
[0023] The moment of inertia of the club head as measured about a longitudinal axis of the body member preferably is greater than approximately 350 kg·mm 2 . More preferably, the moment of inertia is within a range of approximately 400 kg·mm 2 to approximately 600 kg·mm 2 , and most preferably is within a range of approximately 500 kg·mm 2 to approximately 550 kg·mm 2 .
[0024] The face member preferably comprises aluminum. The body member preferably comprises aluminum. The weight member preferably comprises steel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Preferred features of the present invention are disclosed in the accompanying drawings, wherein similar reference characters denote similar elements throughout the several views, and wherein:
[0026] FIG. 1 shows a top view of a putter head according to the present invention with back weighting;
[0027] FIG. 2 shows a back view of a face member for a putter head according to the present invention with a cavity therein;
[0028] FIG. 3 shows a cross-section of the face member of FIG. 2 taken along line III-III;
[0029] FIG. 4 shows a cross-section of the face member of FIG. 2 taken along line IV-IV;
[0030] FIG. 5 shows a bottom, perspective view of an insert member for a putter head according to the present invention;
[0031] FIG. 6 shows a top, perspective view of the insert member of FIG. 5 ;
[0032] FIG. 7 shows a side view of the insert member of FIG. 5 ;
[0033] FIG. 8 shows a top view of a body member for a putter head according to the present invention;
[0034] FIG. 9 shows a side view of the body member of FIG. 8 ;
[0035] FIG. 10 shows a partial perspective view of the body member according to the present invention with an insert member housed therein;
[0036] FIG. 11 shows a top view of another putter head of the present invention;
[0037] FIG. 12 shows a rear view of the putter head of FIG. 11 ; and
[0038] FIG. 13 shows a bottom view of the putter head of FIG. 11 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0039] Referring to FIGS. 1-10 , the putter construction according to the present development is shown. Putter head 20 includes a face member 22 , a body member 24 , and a back weight member 26 , each of which are secured together as will be discussed. A shaft bore 28 is provided for attachment of putter head 20 to a club shaft.
[0040] As shown in FIGS. 2-4 , face member 22 has a generally flat ball-striking front portion 30 and a back portion 32 . A recessed region or back cavity 34 is formed in back portion 32 , and preferably has a generally cylindrical contour. A pair of recessed wing portions 36 are formed at opposite ends of back cavity 34 , creating a keyway that preferably has a depth less than the maximum depth of back cavity 34 . A hole 40 is formed in each wing portion 36 for receiving a threaded fastener. Preferably, back cavity 34 is substantially symmetric about line ALI, which is also generally parallel to the ground.
[0041] Turning to FIGS. 5-6 , in one embodiment of the present invention, an insert 42 is provided for coupling body member 24 to face member 22 . Insert 42 includes a central, generally cylindrical projecting portion 44 , along with a base portion 46 which creates a keyed portion that is adapted to be received within wing portions 36 of back cavity 34 of face member 22 . A generally cylindrical, tapered portion 45 is also provided, and serves as a further keyed region for aiding in insertion of insert member 42 into body member 24 . More particularly, the overall longitudinal geometry of insert 42 is cylindrical, such that it can rotate in at least one plane or direction within body member 24 as will be described shortly. Base portion 46 includes a pair of holes 50 , which preferably include recessed portions 51 so that the head of a screw or other fastener may be recessed therein.
[0042] The loft of the putter is defined as the angle of the face and a line perpendicular to the sole line measured to a point that is half of the distance of the face height and located on the center of the face. In order to provide adjustment of the loft, the angle of body member 24 related to face member 22 is adjusted by rotation within cylindrical back cavity 34 of face member 22 . With an insert member 42 disposed in body member 24 , and with base portion 46 disposed within wing portions 36 , the loft may be changed to a suitable amount.
[0043] More particularly, with reference to FIGS. 8-10 , body member 24 is generally rectangular and hollow, and includes cylindrical front portion 52 , back portion 54 , and side portions 56 , 58 . Front portion 52 receives an insert member 42 in cylindrical passage 53 . Front portion 52 further includes a slit 55 extending along the length of cylindrical passage 53 , and thus providing a loose fit of insert member 42 when placed in cylindrical passage 53 , which runs parallel to line ALI when front portion 52 contacts back cavity 34 . During setting of the desired loft, body member 24 , with an insert member 42 housed in passage 53 , is loosely coupled to face member 22 . With the insert member 42 resting in wing portions 36 , the body member 24 may be rotated with respect to face member 22 ; the body member rotates about insert member 42 , which is fixed in location and angle with respect to face member 22 . When a desired loft has been set, the insert member 42 may be tightly coupled to face member 22 using screws or other fasteners, which extend through holes 50 , 40 in insert member 42 and face member 22 , respectively. In addition, the rotation of body member 24 with respect to insert member 42 may be arrested through the use of a threaded fastener that extends through threaded hole 57 and connects opposing portions of front portion 52 separated by slit 55 . When the fastener is tightened, the separation between these portions may be decreased such that the gap provided by slit 55 is closed. In turn, the diameter of passage 53 is slightly decreased, locking insert member 42 in place.
[0044] A side flange 66 is provided on a side 56 , 58 , depending on whether the golfer is right-handed or left-handed. A shaft bore 28 for receiving a club shaft extends at least partway through flange 66 , which is oriented at an angle α with respect to a flat edge 68 of body member 24 . Preferably, angle α is between about 5° and about 85°. The desired loft may be set by rotating body member 24 with respect to face member 22 .
[0045] As shown in FIG. 9 , edge 68 is disposed opposite an edge 78 of body member 24 . Edge 78 includes straight potions 80 , 82 which are crooked with respect to each other. Preferably, straight potions 80 , 82 are disposed at an angle β between about 0° and about 30°.
[0046] Body member 24 also includes bores 70 through side walls 56 , 58 . Weight removed from side walls 56 , 58 due to the presence of bores 70 may be redistributed in putter head 20 , such as with back weight member 26 as shown in FIG. 1 . Further to this end, a hole 72 is provided in back portion 54 of body member 24 so that back weight member 26 with a similarly disposed hole 74 may be secured thereto, as with a fastener such as a screw. More than one hole 74 may be provided so that several fasteners may be used. Preferably, back weight member 26 is generally arcuate in shape, and is symmetrically disposed with respect to line CEN along the longitudinal center of body member 24 . Back weight member 26 may further include a central recessed region, so as to conform to the geometry of body member 24 .
[0047] FIG. 11 shows a top view of another putter head 100 of the present invention. FIG. 12 shows a rear view of putter head 100 . FIG. 13 shows a bottom view of the putter head 100 . Club head 100 is designed to have a high moment of inertia MOI. Putter head 100 includes a face member 110 , a body member 120 , and a weight member 130 .
[0048] Face member 110 is elongate, with the length being greater than the width. The width of face member 110 may be substantially uniform along its length (there may be an inset for seating body member 120 ). Face member 110 has a generally flat ball-striking front surface 112 , a rear surface 114 , and a bottom surface 115 . Rear surface 114 may contain holes 116 for inserting weights 117 . Preferably, there is a hole 116 and a weight 117 toward each end of rear surface 114 . Face member 110 is preferably made of aluminum.
[0049] Front surface 112 has a leading edge 113 . Leading edge 113 is preferably beveled to create a smooth transition between face surface 112 and bottom surface 115 . Beveling reduces the likelihood of snagging the club on the ground, or “grounding” the club, during a putting stroke. Bottom surface 115 may also be angled at ends thereof to further reduce the likelihood of grounding the club in the event of a toe-up or toe-down stroke.
[0050] Face member 110 has a loft angle within a range of approximately 0° to approximately 10°. As used herein, “within a range” includes the end values. Face member 110 preferably has a loft angle of approximately 4° or less with shaft 140 in the vertical position. A 4° loft angle has been determined the ideal loft angle for a putting stroke. See the inventor's U.S. patent application Ser. No. 09/156,540, now pending and which is incorporated herein by reference, for further discussion regarding putter loft angle. The presence of weight member 130 and the location of the club head center of gravity CG behind face member 110 creates a dynamic loft angle effect, which causes the ideal loft angle to be less than 4°. The loft angle preferably is approximately 3.5° or less, and more preferably is approximately 3° or less. This angle may be varied according to the needs of the individual user. For example, if the user has a 2° forward press, face member 110 will be designed with a loft angle of 2° greater, resulting in the proper dynamic loft angle during use. Likewise, if the user has a rearward press, the loft angle of face member 110 can be reduced to produce the proper dynamic loft angle.
[0051] Body member 120 is coupled to rear surface 114 and extends away from rear surface 114 in a substantially perpendicular fashion. Body member 120 has a length and a width, the length being greater than the width. In a preferred embodiment, the length of club head 100 is substantially the same as the length of face member 110 . Body member 120 is coupled to face member 110 such that face member 110 is slightly lower than body member 120 . This encourages proper contact between strike surface 112 and the ball, and further minimizes the likelihood of grounding the club during the swing. Body member 120 is preferably made of aluminum.
[0052] The illustrated embodiment of body member 120 contains a plurality of holes 122 to reduce its weight. This gives body member 120 the appearance of having rails, and helps to increase the MOI, as discussed below. In an alternative embodiment, body member 120 contains no holes.
[0053] Body member 120 contains shaft mount 124 for connecting a shaft 140 to club head 100 . Shaft mount 124 may be positioned toward a side of body member 120 as shown in the figures, or it may be formed within the rectangular frame of body member 120 . For example, shaft 140 may be coupled to body member 110 within one of holes 122 . Shaft mount 124 is positioned behind face member 110 approximately at the midpoint along the length of body member 110 . This location, which is near the club head center of gravity CG, provides for a more flowing stroke. Shaft mount 124 may be positioned a distance L S behind strike face 112 . Distance L S is preferably approximately 1.5 inches to approximately 2 inches. Club head 100 has a length L having a midpoint MP. Shaft mount 124 may alternatively be positioned between midpoint MP and strike face 112 , and more preferably is positioned a distance of approximately 25% of putter head length L to approximately 50% of putter head length L behind strike face 112 .
[0054] Shaft 140 may preferably by bent to give a straight, no offset appearance at address. Shaft 140 is preferably coupled to produce a 71° lie angle. Shaft 140 may be of any standard length, including a length of approximately 35 inches or more. Alternate preferable lengths for shaft 140 include approximately 37 inches and approximately 53 inches.
[0055] Face member 110 and body member 120 are coupled to form a “T-frame” shape. In addition to increasing MOI, as discussed below, the T-frame allows for improved accuracy. During the putting stroke, body member 120 provides the user with a visual alignment of the putt. Any slight misalignment of club head 100 that may likely go unnoticed with a traditional putter may be readily apparent via the T-frame design of club head 100 . By aligning elongate body member 120 with the intended ball path, the user can ensure the putter is aligned as desired. By doing so, the user is more likely to hit the intended shot.
[0056] Weight member 130 is coupled to body member 120 at the opposite end from face member 110 . This placement of weight member 130 increases the MOI of club head 100 . Inertia is a property of matter by which a body remains at rest or in uniform motion unless acted upon by some external force. MOI is a measure of the resistance of a body to angular acceleration about a given axis, and is equal to the sum of the products of each element of mass in the body and the square of the element's distance from the axis. Thus, as the distance from the axis increases, the MOI increases. By placing weight member 130 at the distal end of body member 120 relative to face member 110 , MOI can be significantly increased without substantially altering the overall weight of club head 100 . This MOI increase is greater than that possible with heel-to-toe weighting of conventional putters, due to operational weight limits. When a club, such as a putter, strikes a ball off-center, there is a tendency for the club to rotate about a vertical axis passing through the club head center of gravity CG. This club rotation causes the shot or putt to deviate from the intended course by either a push/pull (straight ball path), slice/hook (curved ball path), or combination thereof. Increasing the MOI about this axis, such as through use of weight member 130 , increases the resistance to club head rotation and creates more accurate off-center shots.
[0057] During an ideal putting stroke, the putter head is not rotated. That is, face member 1 10 is kept substantially perpendicular to the intended putt path. During actual putting strokes, however, golfers frequently rotate the putter about a vertical axis, resulting in the ball being sent awry. Increasing the MOI about the vertical axis passing through club head center of gravity CG also helps prevent this unintended and undesired rotation of club head 100 .
[0058] Club head 100 has a center of gravity CG. Center of gravity CG is the point at which the entire weight of club head 100 may be considered as concentrated. This is also the point through which club head 100 will rotate if a force not passing through center of gravity CG is exerted thereon. Moving center of gravity CG away from strike face 112 increases the MOI and stability of club head 100 . Center of gravity CG is preferably located a distance LcG behind strike face 112 . Distance LCG preferably is approximately 1 inch to 4 inches. More preferably distance LCG is approximately 1.5 inches to approximately 2 inches, and most preferably distance LCG is approximately 1.7 inches. Center of gravity CG is preferably between midpoint MP and weight member 130 . Center of gravity CG is preferably located a distance of approximately 50% of length L to approximately 75% of length L behind strike face 112 . Shaft mount 124 is preferably positioned between midpoint MP and strike face 112 , and more preferably is positioned a distance of approximately 25% of length L to approximately 50% of length L behind strike face 112 . Club head 100 has a weight. Approximately 50% of the weight to approximately 75% of the weight is located on a weight member side of shaft mount 124 . This positioning of center of gravity CG and shaft mount 124 , along with the weights of face member 110 , body member 120 , and weight member 130 , give club head 100 a MOI as measured about a vertical axis passing through center of gravity CG that is preferably greater than approximately 550 kg·mm 2 . More preferably, the moment of inertia is within a range of approximately 600 kg·mm 2 to approximately 800 kg·mm 2 , and most preferably is within a range of approximately 700 kg·mm 2 to approximately 750 kg·mm 2 .
[0059] An off-center hit may also tend to make club head 100 rotate about shaft mount 124 . That is, the club tends to rotate about shaft 140 . The placement of weight member 130 , however, also tends to increase the MOI about shaft mount 124 more than is possible with heel-to-toe weighting of conventional putters. The MOI of club head 100 as measured about a vertical axis passing through shaft mount 124 preferably is greater than approximately 550 kg·mm 2 . More preferably, the moment of inertia is within a range of approximately 600 kg·mm 2 to approximately 900 kg·mm 2 , and most preferably is within a range of approximately 800 kg·mm 2 to approximately 850 kg·mm 2 .
[0060] Another common problem resulting in misaligned putts is rotation of the club head through a horizontal axis substantially perpendicular to face member 110 . That is, about an axis collinear with the intended path of the putt. This toe-up or toe-down misalignment frequently occurs during the putting stroke. The position of weight member 130 and its arcuate design increase the MOI about the horizontal axis. Club head 100 preferably has a MOI as measured about a longitudinal axis of body member 120 that is preferably greater than approximately 200 kg·mm 2 . More preferably, the moment of inertia is within a range of approximately 200 kg·mm 2 to approximately 400 kg·mm 2 , and most preferably is within a range of approximately 250 kg·mm 2 to approximately 300 kg·mm 2 .
[0061] Weight member 130 also helps produce more accurate results for on-center shots by helping the user “swing through” the ball rather than decelerating or “slapping” the ball. Since weight member 130 is separated from strike surface 112 by body member 120 , weight member 130 will be traveling downward (i.e., working with gravity) when club head 100 strikes the ball. This results in a smoother putting stroke, and a more accurate shot.
[0062] Placing weight member 130 further towards the rear of club head 100 increases the MOI, but also has the undesired effect of increasing instability. If weight member 130 is placed too far away from face member 110 , the club head can become “tipsy.” That is, placing weight member 130 too far back may cause club head 100 , when the club is placed on a level surface, to tilt backward. Thus, club head 100 must be designed to simultaneously maximize MOI and ensure adequate stability.
[0063] One way to achieve this balance is by using the proper ratio of the weight of weight member 130 to the overall weight of club head 100 . Weight member 130 preferably comprises at least 25% of the entire weight of club head 100 . More preferably, weight member 130 comprises at least 50% or at least 75% of the entire weight of club head 100 . Weight member 130 is preferably made of steel, which has a greater density than aluminum. In a preferred embodiment, weight member 130 has a weight within a range of approximately 10 g to approximately 200 g, and more preferably within a range of approximately 125 g to approximately 170 g. The overall weight of club head 100 preferably is within a range of approximately 200 g to approximately 600 g, and more preferably within a range of approximately 300 g to approximately 500 g. Alternatively, the overall weight of club head 100 may be similar to the weight of conventional club heads.
[0064] Stability of club head 100 is also increased by weights 117 in face member 110 . Stability may also be increased by bending weight member 130 such that its ends are curved toward face member 110 , as shown in the figures. The illustrated horseshoe shape moves the center of gravity WCG of weight member 130 forward, toward face member 110 , and provides a pleasing appearance for club head 100 . Weight member 130 is symmetrically disposed about body member 120 . The ends of weight member 130 may be curved forward to any desired amount, including such that it contacts face member 110 . The ends of weight member are preferably bent such that they are a distance L WM from strike face 112 . Distance L WM is preferably from 0 inch to approximately 1.5 inches, and more preferably from 0 inch to approximately 1 inch. Extending the ends of weight member 130 to face member 110 gives club head 100 a mallet-like appearance, which may be desirable to some golfers. In a preferred embodiment, weight member 130 has a circular cross section. Center of gravity WCG is located behind center of gravity CG, and is a distance L WCG from strike face 112 . Distance LWCG is preferably from 0 inch to approximately 3 inches.
[0065] While various descriptions of the present invention are described above, it should be understood that the various features can be used singly or in any combination thereof. Therefore, this invention is not to be limited to only the specifically preferred embodiments depicted herein.
[0066] Further, it should be understood that variations and modifications within the spirit and scope of the invention may occur to those skilled in the art to which the invention pertains. For example, in an alternate embodiment, the mating portions of face member 22 and body member 24 may include a series of facets along a generally cylindrical shape, instead of smooth cylindrical surfaces. Such facets may provided a more positive engagement of the components during fitting. In addition, in another embodiment, body member 24 may be secured to face member 22 without an insert member 42 . Front portion 52 of body member 24 may be provided with projections that mate with wing portions 36 in face member 22 . Accordingly, all expedient modifications readily attainable by one versed in the art from the disclosure set forth herein that are within the scope and spirit of the present invention are to be included as further embodiments of the present invention. The scope of the present invention is accordingly defined as set forth in the appended claims.
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A golf putter head adapted for attachment to a club shaft is provided with a face member having a strike face and a cylindrical back cavity, and a body member configured to fit and rotate within the back cavity is disclosed. Selective rotation of the body member within the back cavity sets a loft of the putter head. The weighting of the putter is adjusted by securing a weight member to the body member. A golf putter head having an increased moments of inertia is also disclosed. The putter head includes a face member, a body member, and a weight member. Placement of the weight member is such that the moments of inertia are increased and the putter head is stable.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a continuation of and claims priority to International Application No. PCT/US2010/27366, filed Mar. 15, 2010, which in turn claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 61/159,919, filed Mar. 13, 2009. Each of the aforementioned patent applications is incorporated by reference herein in its entirety.
BACKGROUND
[0002] 1. Field of the Disclosure
[0003] The present disclosure relates to novel systems for transmitting drive force. Particularly, the present disclosure provides new crankshaft configurations for various purposes. New crankshaft configurations are also provided that are believed to be particularly suitable with manually operated drive systems, such as on bicycles.
[0004] 2. Description of Related Art
[0005] A conventional, commercially available internal combustion engine utilizes a crankshaft to transform a reciprocating piston motion into a rotary motion. As the piston moves within its cylinder in response to expanding gases of combustion, rotary motion is imparted to the crankshaft through a connecting rod. One end of the connecting rod is affixed to a wrist pin pivotally secured to the piston, while another end is rotatably journaled about an offset throw of the crankshaft. When multiple cylinder arrangements are desired, the crankshaft is extended to include an additional offset throw for each piston connecting rod.
[0006] As the piston transmits force created by the combustion of fuel to the crankshaft by way of the connecting rod, the angularity of the connecting rod causes a considerable side thrust to be exerted by the piston on the walls of the cylinder. Such thrust is generally absorbed by a skirt portion of the piston; that is, the section below the piston rings. Further, this side thrust or angular force absorbs a portion of the linear energy and contributes to the inefficiency of the conversion of the linear movement of the piston into the rotary movement of the crankshaft.
[0007] In a conventional internal combustion engine, the crankshaft is supported by main bearings, and at the end of the crank throw, a crank pin holds the connecting rod. In order 4o to compensate for energy lost to angular forces, the piston rod is lengthened and the crank throw is made longer than the radius of the cylinder bore. Thus, additional space must be allowed to accommodate the crank throw. In addition, to avoid a downward thrust of the piston while the piston is at the upper limit of the stroke (top dead center), the crankshaft or crank pin may be offset from the longitudinal center of the cylinder, or alternatively a timing mechanism may be employed to delay spark ignition in the combustion chamber. These factors further contribute to increased size of so commercially available internal combustion engines.
[0008] Such conventional methods and systems generally have been considered satisfactory for their intended purpose. Various attempts have been made in the art to improve internal combustion engines. Examples of such attempts can be found, for example, in U.S. Pat. No. 7,263,966, U.S. Pat. No. 7,201,133, U.S. Pat. No. 5,417,309, U.S. Pat. No. 5,351,566, U.S. Pat. No. 4,395,977, U.S. Pat. No. 4,270,395, U.S. Pat. No. 4,078,439, U.S. Pat. No. 2,628,602 and U.S. Pat. No. 2,513,514. Each of the aforementioned references is incorporated by reference herein in its entirety.
[0009] However, many of the foregoing attempts have resulted in very complex mechanisms with a significant number of moving parts, which is very undesirable. Applicant believes that there is a long felt need in the art for further improved systems that improve upon the existing art.
SUMMARY OF THE DISCLOSURE
[0010] Advantages of the present disclosure will be set forth in and become apparent from the description that follows. Additional advantages of the disclosure will be realized and attained by the methods and systems particularly pointed out in the written description and claims hereof, as well as from the appended drawings.
[0011] To achieve these and other advantages and in accordance with the purpose of the disclosure, as embodied herein, the disclosure includes an exemplary device for converting linear motion into rotational motion. The device includes a housing defining at least one bore therein along a first direction, and a piston movably disposed in the bore of the housing. The piston defines a generally circular bore therethrough along a direction generally perpendicular to the first direction. The bore of the piston defines a first engagement surface having a first diameter. The device further includes a crankshaft defining an axis of rotation and generally elongate body. The body has an offset portion that is laterally displaced from the axis of rotation. The surface of the offset portion defines a second engagement surface thereon having a generally circular cross-section and a second diameter. In accordance with a particular embodiment, the second diameter is about one half of the first diameter and the second engagement surface is adapted to engage with the first engagement surface. The crankshaft is forced through an angular rotation when the piston is displaced along the bore, and the axis of rotation of the crankshaft does not move with respect to the housing.
[0012] In accordance with a further aspect, the device further includes at least one bearing interposed between (i) a generally circular track defined in the bore of the piston and (i) the surface of the crankshaft. The bearing maintains the engagement between the first and second engagement surfaces when the piston is displaced along the bore of the housing resulting in rotation of the crankshaft. In accordance with one embodiment, the bearing is generally crescent-shaped.
[0013] In accordance with a further embodiment, the first and second engagement surfaces can define interdigitating gear teeth thereon. Preferably, the piston bore and cross section of the offset portion of the crankshaft defining the second engagement surface are circular in shape.
[0014] In accordance with still a further aspect, the housing can further define a second bore therein, and the device can further includes a second piston movably disposed in the second bore of the housing. The second piston preferably defines a generally circular bore therethrough along a direction generally perpendicular to the first direction. The bore of the piston defines a third engagement surface having a first diameter that is adapted and configure to mate with a fourth engagement surface defined on a second offset portion of the crankshaft.
[0015] In accordance with yet a further aspect, the piston is adapted and configured to reciprocate along the bore of the housing when the crankshaft rotates. In accordance with one embodiment, the housing can further define at least one intake valve and one exhaust valve proximate one end or at each end of the bore. If desired, the device can be an internal combustion engine wherein fuel is introduced into the intake valve during operation and combusted to drive the crankshaft. By way of further example, the device can be a pump or compressor, wherein a fluid to be pressurized by the device is introduced into the intake valve during operation. Preferably, the motion of the piston in the bore of the housing is sinusoidal.
[0016] The disclosure also provides a device for converting elliptic or linear reciprocating motion into angular motion. The device includes a central shaft defining an axis of rotation and a first crank portion. The device further includes a second crank portion lying in substantially the same plane as the first crank portion and pivotally attached to the first crank portion at a pivot point. the second crank portion is adapted to freely pivot about the central shaft about the axis of rotation and the pivot point is separated by a distance l 2 from the axis of rotation. The first crank portion preferably includes a load receiving point displaced a distance l 1 from the first pivot point, and the second crank portion preferably extends substantially perpendicularly from the central shaft.
[0017] In accordance with a further aspect, the first crank portion preferably includes a first sprocket affixed thereto in axial alignment with the pivot point, and wherein the central crankshaft includes a second sprocket affixed thereto in axial alignment with the axis of rotation. If desired, the device can further include a chain loop encircling the first and second sprockets, wherein rotation of the first sprocket about the pivot point causes rotation of the second sprocket and the central shaft by way of the chain. Alternatively, the device can instead include first and second gears in lieu of sprockets and a chain as described above or a third idler gear interposed between the first and second gears, wherein rotation of the first gear about the pivot point causes rotation of the second gear and the central shaft by way of the third gear. Preferably, the first sprocket and second sprockets (or gears, rollers or pulleys, described below) are of substantially the same diameter.
[0018] In accordance with a further aspect of the disclosure, l 1 can be substantially equal to l 2 , resulting in the load receiving point traversing a substantially linear path as the central shaft is angularly driven. If desired, l 1 can be less than l 2 , resulting in the load receiving point traversing a substantially elliptical path as the central shaft is angularly driven.
[0019] In accordance with an alternative embodiment, the first crank portion can include a first roller affixed thereto in lieu of a sprocket in axial alignment with the pivot point, and wherein the central crankshaft includes a second roller affixed thereto in axial alignment with the axis of rotation. If desired, the device can further include a belt encircling the first and second rollers, wherein rotation of the first roller about the pivot point causes rotation of the second roller and the central shaft by way of the belt. Alternatively, the device can further include a third idler roller interposed between the first roller and second roller, wherein rotation of the first roller about the pivot point causes rotation of the second roller and the central shaft by way of the third roller.
[0020] If desired, the first crank portion can include a first pulley in lieu of a sprocket affixed thereto in axial alignment with the pivot point, and wherein the central crankshaft includes a second pulley affixed thereto in axial alignment with the axis of rotation. The device can further include a belt encircling the first and second pulleys, wherein rotation of the first pulley about the pivot point causes rotation of the second pulley and the central shaft by way of the belt. If desired, the belt and pulleys can have interdigitating teeth.
[0021] In accordance with a further embodiment, a machine is provided including a sprocket/gear/roller/pulley drive mechanism as described hereinabove. The machine can be, for example, a bicycle, a tricycle, a quadricycle, an exercise bicycle, an electric generator, a pedal taxi or a paddleboat.
[0022] It is to be understood that the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the disclosed embodiments.
[0023] The accompanying drawings, which are incorporated in and constitute part of this specification, are included to illustrate and provide a further understanding of the method and system of the disclosed embodiments. Together with the description, the drawings serve to explain principles of the disclosed embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIGS. 1-22 represent various views of a first exemplary illustrative embodiment of a device and system for transmitting drive force in accordance with the present disclosure, or portions thereof.
[0025] FIGS. 23-25 represent various schematic views of a second exemplary illustrative embodiment of a device and system for transmitting drive force in accordance with the present disclosure.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0026] Reference will now be made in detail to the present preferred embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. The method and corresponding steps of the disclosed embodiments will be described in conjunction with the detailed description of the system.
[0027] The modern piston internal combustion engine has undergone an evolution since its inception although, the basic components used to perform the motion of the slider crank model has remained the same. The piston, crank and connecting rod have always been apart of the piston engine. Exemplary disclosed embodiments will be discussed does not have the same elements found in the traditional piston engine. For example, there is no need for the connecting rod and piston to be separate parts due to the linear motion of the bearing which connects the piston to the crank, relative to the engine block. To achieve this, gearing is preferably employed between the crankshaft and the piston as illustrated in the exemplary embodiment of FIGS. 1-22 .
[0028] The geometric relation that facilitates the operation of this embodiment may be defined in a hypotrochoid's geometry where the inner rotating circle is half the size of the larger stationary circle as depicted in FIG. 1 . As the inner circle rotates about the outer circles center it is also forced to rotate about its own center at a ratio of 2 to 1. If any point on the smaller circle is then plotted through the rotation it may be seen that it will create a reciprocating sinusoidal motion as depicted in FIG. 2 .
[0029] As illustrated in FIGS. 1 and 2 , conceptually, the inner circle acts as the shaft and is constrained to one degree of freedom, allowed only to rotate only about the center of the system. The outer circle depicted in FIG. 2 is the piston and is constrained so that only a vertical translation is allowed. This is done simply by constraining the piston in the cylinder of the housing and by providing spacers, or bearings, that rotate around the crankshaft and within the piston. Specifically, as illustrated in the Figures, a two-headed piston 10 is depicted situated in the bore 22 of a housing 20 . A crankshaft 30 is provided having a main portion 32 that rotates but that does not otherwise move with respect to the housing 20 and an offset portion 34 depicted with a plurality of gear teeth 36 thereon. Piston further defines a generally circular bore 12 therethrough depicted with a plurality of gear teeth 14 thereon that interdigitate and mesh with teeth 36 of crankshaft 30 . A crescent-shaped bearing 40 is disposed on either side of the piston 10 , wherein the radially outer surface 42 of bearing rides in a substantially circular track 16 of piston 10 and the radially inner surface 44 of bearing 44 rides on the surface 38 of crankshaft. Bearings 40 keep proper spacing between the gears. The gearing 14 , 36 and spacers 40 are both responsible for transmitting torque to the crankshaft 30 .
[0030] Vibration is a particular concern in traditional piston engine design due to the irregular oscillation of the piston in the slider crank mechanism. Many different engine configurations have been used in an effort to completely balance the piston engine but, because of the connecting rod masses change in relative position to the crankshaft axis there will be an inertia variation not found in the disclosed embodiment. (See References [1, 10] below). In the disclosed embodiment, the piston 10 does not operate according to a slider crank mechanism. Rather, the piston 10 moves in a vertical (for purposes of reference) sinusoidal motion. This allows for both forces and moments to be optimized using fewer cylinders. It will be appreciated that any desired number of pistons and cylinders can be used to make an engine or pump in accordance with the exemplary embodiment (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 pistons/cylinders).
[0031] Some literature references have suggested that friction due to the piston ring assembly may be responsible for 40-75 percent of the entire engine friction (See References [2-5] below). Ring assembly friction is a function of the coefficient of friction and the normal load between the cylinder wall and ring assembly (See Reference [6] below). In a traditional piston engine there are three components to the normal load: (i) the static ring pressure, (ii) the inertia forces, and (iii) the pressure due to the combustion gasses. While the inertia forces in the exemplary embodiment do not go to zero, this force is considerably less than in the traditional piston engine.
[0032] The lack of a need for a connecting rod in the exemplary embodiment due to the entirely vertical component of force exerted to the crank pin means that two horizontally opposed pistons may be connected as one rigid part where each piston is offset 180 degrees. This enables the engine to be more compact using less space for the same piston displacement. It also has the ability to reduce the rotating and overall mass of the engine. Secondary motion of the piston in the horizontal direction or, piston slap is an entirely separate occurrence in the disclosed embodiment and can be expected to be significantly reduced without a horizontal force on the piston. Depending on a particular engine configuration, the illustrative embodiment also has the ability to reduce the total number of engine parts as compared with a traditional internal combustion engine.
[0033] A model has been developed by Applicant to measure and compare the torque distribution throughout the power stroke for both the traditional piston engine and the illustrated embodiment. Because of the linear sinusoidal motion in the illustrated embodiment, piston velocity just before and just after top dead center can be expected to be lower than in the traditional configuration. This creates a different torque distribution with more torque coming later in the power stroke, causing a smoother more desirable power output.
[0034] Piston position, velocity, acceleration and jerk can also be expected to change significantly by applying a linear sinusoidal motion to the piston position as with the disclosed illustrative embodiment. In the traditional slider crank mechanism of typical engines there is significantly higher peak acceleration when compared to that of the sine wave. Depending on the length of the connecting rod, peak acceleration may be reduced as much as 20 percent with respect to the disclosed embodiment (by way of comparison) while maximum jerk can be expected to be reduced by as much as 40 percent. This can be expected to reduce forces exerted on the piston, connecting rod and crankshaft as compared with a traditional engine design.
Geometric Relations
[0035] In the disclosed embodiment, there is a common relation of motion between the piston and the crankshaft's center of rotation which is defined by the hypotrochoid's geometry ( FIGS. 1-2 ). With reference to FIG. 11 , equations 1 and 2 below govern point P as the smaller circle rolls around the circumference of the larger one. These equations are parametric in the variable t:
[0000]
x
=
(
a
-
b
)
·
cos
(
t
)
+
c
·
cos
[
(
a
-
b
)
·
t
b
]
(
1
)
y
=
(
a
-
b
)
·
sin
(
t
)
+
c
·
sin
[
(
a
-
b
)
·
t
b
]
(
2
)
[0036] In the disclosed exemplary embodiment, the smaller circle of FIG. 11 is half the size of the larger and, c is equal to b. This puts the rotating point P at the edge of the smaller circle and causes it to move linearly between its two points of contact with the larger circle. If a line is drawn through these two contact points it will intersect the larger circle, passing through its center. If the time derivative is taken of the position, P as the small circle is rolling at a constant angular velocity around the circumference of the larger circle, the resultant velocity profile of point P will be sinusoidal.
Piston Position, Velocity and Acceleration
[0037] Piston position for the traditional configuration and the exemplary embodiment are given in equations (3) and (4) respectively. The traditional configuration and assumes there is no piston offset.
[0000]
P
traditional
=
-
[
(
1
+
r
)
-
[
1
2
-
(
sin
(
θ
)
·
r
)
2
+
cos
(
θ
)
·
r
]
]
(
3
)
P
PCC
=
r
·
cos
(
θ
)
(
4
)
Vel
PCC
=
θ
P
PCC
(
θ
)
·
ω
(
5
)
Vel
traditional
=
θ
P
traditional
(
θ
)
·
ω
Acc
PCC
=
θ
Ve
1
PCC
(
θ
)
·
ω
(
6
)
Acc
traditional
=
θ
Ve
1
traditional
(
θ
)
·
ω
Jerk
PCC
=
θ
Acc
PCC
(
θ
)
·
ω
(
7
)
Jerk
traditional
=
θ
Acc
traditional
(
θ
)
·
ω
[0038] To obtain the piston velocity through one complete crankshaft rotation at 2000 revolutions per minute Equation (5) is used (see Reference [8] below). Results show that the exemplary embodiment has approximately a 6 percent smaller peak velocity than a traditional engine configuration with a 3 inch stroke and 5 inch connecting rod as illustrated in FIG. 12 . As the length of the connecting rod goes to infinity, the profile of the traditional engine piston velocity becomes sinusoidal or matches that of the PCC. A larger peak velocity occurs as the connecting rod becomes smaller.
[0039] The second time derivative of position, multiplied by crank angular velocity squared may be calculated to obtain piston acceleration (Equation 6) (see Reference [8] below). The measure of acceleration is g's, or, the number of times the force of gravity the piston is experiencing. The peak acceleration is shown to be approximately 24 percent greater in the traditional piston engine as illustrated in FIG. 13 . The change in rate of acceleration with respect of time or, jerk may be calculated using Equation (7) and is graphed in FIG. 14 . As is apparent, the traditional slider crank mechanism generates approximately 44 percent more jerk then the sinusoidal piston displacement.
Torque Distribution
[0040] Before the instantaneous friction components may be measured the torque distribution must be defined throughout the power stroke. To do this an isentropic process is assumed for an ideal gas. This introduces an error to the model due to temperature change, blow by and the flame rate. However, the pressure distribution created throughout the power stroke closely resembles the one produced and measured in Reference [6]. An initial pressure is prescribed of 700 psi at top dead center. The pressure in the cylinder for the remaining 180 degrees is defined by Equation (8) (Reference [8]). Volume is a function of the piston position (Equation 3), bore and compression ratio. Air is assumed for the ideal gas and the corresponding constant is taken as 1.4.
[0000]
Pressure
(
θ
)
=
P
1
·
(
Vol
(
0
)
Vol
(
θ
)
)
γ
-
1
(
8
)
[0041] The pressure is then multiplied by the area of the piston face to give the applied vertical force from top dead center to bottom dead center. Using simple geometry and a free body diagram the resultant force applied along the connecting rod and, the horizontal force, between the piston and the cylinder wall may be calculated using Equations (9) and (10) respectively. To obtain the torque about the crankshaft axis the moment arm (Equation 11) is multiplied by the force exerted through the connecting rod. This yields the torque distribution seen in FIG. 15 .
[0000]
F
2
(
θ
)
=
B
·
(
P
(
θ
)
)
cos
(
a
sin
(
c
s
·
sin
(
θ
)
)
)
(
9
)
F
3
(
θ
)
=
B
·
(
P
(
θ
)
)
tan
(
a
cos
(
sin
(
θ
)
·
c
s
)
)
(
10
)
1
(
θ
)
=
[
sin
[
180
deg
-
a
cos
(
sin
(
θ
)
·
c
s
)
-
(
90
deg
-
θ
)
⌋
⌋
·
c
(
11
)
T
traditional
(
θ
)
=
F
2
(
θ
)
·
1
(
θ
)
(
12
)
[0042] A similar calculation may be used for the exemplary disclosed embodiment (PCC) where the moment arm is defined in Equation (14) and the force being exerted on the moment arm is defined in Equation (13).
[0000] F PCC (ω):= B ·( P (ω)) (13)
[0000] l PCC (ω)= R 1 ·sin(ω) (14)
[0000] T PCC (ω)= l PCC (ω)· F PCC (ω) (15)
[0043] Torque is calculated in the same way that it was in the traditional configuration, by multiplying the force by the moment arm (Equation 15). The resultant work may be calculated integrating the torque curve from 0 to 180 degrees (Equations 14-15). Total work of the traditional configuration comes to approximately 295 joules while the work of the exemplary disclosed embodiment comes to approximately 297 joules, producing a 0.01 percent discrepancy, acceptable for this calculation. These numbers ensure that the calculations were done properly as, if one were significantly larger than the other the system would not adhere to the law of conservation of energy. The resultant torque curves are plotted against each other in FIG. 15 . The plots show a significantly more even curve where, the exemplary disclosed embodiment remains concave down throughout the power stroke. This shows that the exemplary disclosed embodiment would have a smoother output which is more significant to smaller engines with fewer pistons. Simulation of the fluid flow air-fuel mixture inside the combustion chamber during the intake stroke has not been taken into consideration. It is believed that there is less turbulence inside an engine using the exemplary disclosed embodiment and thus, poorer mixing tendencies.
[0000]
T
traditional
:=
1
180
deg
·
∫
0
180
deg
T
traditional
(
θ
)
θ
(
14
)
T
PCC
:=
1
180
deg
·
∫
0
180
deg
T
PCC
(
θ
)
θ
(
15
)
Friction and Efficiency
[0044] A model has been adapted from Zweiri, Whidborne and Seneviratne (References [6, 10, and 11]) to aid in calculating the instantaneous friction torque of the components comprised in both the PCC and the standard piston engine. This is a favorable model because of its flexibility in applying different constraints found in the PCC without developing new empirical coefficients.
[0045] Piston assembly friction torque is of particular importance because of the significant reduction in the side thrust exerted on the piston in the PCC. The piston rings dominate the total piston ring assembly friction (Reference [12]). Equations given in Reference [6] show three components to the ring assembly friction torque. They are comprised from static ring tension (Equation 16), gas pressure (Equation 17) and the inertia force (Equation 18).
[0000]
T
static
(
θ
)
=
η
·
r
·
G
(
θ
)
·
∑
i
=
1
N
[
[
E
1
.
·
gap
7.07
·
d
r
·
(
d
r
B
i
-
1
)
3
]
·
B
1
.
·
d
r
·
π
]
(
16
)
T
gaspressure
(
θ
)
=
η
·
r
·
G
(
θ
)
·
∑
i
=
1
N
(
a
1
·
P
(
θ
)
-
P
atm
·
π
·
d
r
·
B
i
)
(
17
)
T
inertia
(
θ
)
=
η
·
r
·
G
(
θ
)
·
[
P
(
θ
)
-
atm
·
(
π
4
)
·
b
2
-
M
·
G
1
(
θ
)
·
(
θ
)
2
η
+
G
3
(
θ
)
]
(
18
)
[0046] The hydrodynamic friction coefficient is given in Equation (19) and changes according to cycle. Because it is a function of piston velocity, it is different in the disclosed embodiments than in the standard piston engine. The empirical coefficient, c 1 was used in calculating piston assembly friction torque. It was taken from the Stribeck diagrams assuming mixed lubrication. This number can be expected to be similar for both traditional and disclosed designs considering similarities in basic conception. In Equation (16) and (17) the subscript i refers to each piston ring while N is the number of piston rings. The reduction coefficient, a i is taken as 1 for the first ring and, 0.5 for the second.
[0000]
η
(
θ
)
=
∑
i
=
1
N
[
c
1
-
[
c
1
-
μ
·
ω
·
r
·
G
(
θ
)
[
E
1
.
·
gap
7.07
·
d
r
·
(
d
r
B
i
-
1
)
3
+
P
(
θ
)
-
atm
]
·
B
i
]
·
sin
(
θ
)
]
for
1.5
π
≤
θ
≤
2.5
π
η
(
θ
)
=
μ
·
ω
·
r
·
G
(
θ
)
[
E
1
.
·
gap
7.07
·
d
r
·
(
d
r
B
i
-
1
)
3
+
P
(
θ
)
-
atm
]
·
B
i
otherwise
(
19
)
[0047] The skirt friction torque is calculated using Equation (20) and is also a factor of piston velocity. The geometric function, G p (θ) is the PCC sinusoidal equivalent for the velocity profile G(θ), used in the traditional engine.
[0000]
T
traditionalskirt
(
θ
)
=
(
μ
·
ω
·
r
·
G
(
θ
)
O
c
)
·
b
·
L
s
·
r
·
G
(
θ
)
T
PCCskirt
(
θ
)
=
(
μ
·
ω
·
r
·
G
p
(
θ
)
O
c
)
·
b
·
L
s
·
r
·
G
p
(
θ
)
(
20
)
[0048] This model has been focused at measuring total piston assembly friction losses during the power stroke or, 0 to 180 degrees. This is the time when the highest mechanical losses occur due, to pressure exerted on the piston from the combustion process. To obtain the individual components of work for all parts of the piston assembly Equation (21) is used. A summary of results may be seen in Table (1) while graphical results may be seen in FIGS. 16 and 17 .
[0000]
W
=
∫
θ
i
θ
f
T
θ
(
21
)
[0000]
TABLE 1
Summary of work done by piston assembly components (J)
Disclosed
Torque
Traditional
Embodiment
Inertia
8.295
0
Static Ring Tension
00.001361
0.0003214
Gas Pressure Force
4.058
3.164
Skirt Friction
1.858
1.805
Total
14.213
4.97
[0049] With respect to the presently illustrated disclosed embodiment, the horizontal inertia force may not be reduced to zero as forces transmitted to the gear and spacer require a horizontal force on the piston to balance the forces in the x-direction. A free body diagram of all forces and moments may be seen in FIG. 18 . In this Figure the crank rotates about point A while the connection between the crank and piston is at point B. This configuration is complex to analyze as the force from the combustion chamber is exerted to the crank through the piston and also through the spacer. It is believed that this design is also operable without the gearing if the piston is constrained with respect to the crank at 90 degrees. At this angle without gearing the crank can rotate without causing any translational movement of the piston. The moment, l m transmitted to the crank through the spacer seen in FIG. 19 is given in Equation 22. The force exerted to the piston from the combustion chamber is F i . The resultant force exerted from the spacer to the crank is F cr and the horizontal component of this force is F st . The mass is M. This horizontal force may not be applied directly to the piston wall as the piston is constrained to the crank by the gearing at point B. A moment will be created about point B by these forces which are countered by the force, F 1 between the piston wall and the piston. To solve for these forces the sum of moments may be taken about point B (Equation 23). Solving for F 1 yields Equation 27. The side thrust force on the piston may then be found by taking the sum of moments about point B. This force may then be used in combination with the previous section to determine the friction losses in the piston assembly.
[0000]
l
m
(
θ
)
=
2
·
c
·
sin
(
θ
)
·
sin
(
90
-
θ
)
(
22
)
∑
M
B
=
0
=
-
F
1
·
l
2
+
(
F
i
+
M
y
.
t
)
·
l
3
+
F
f
·
(
c
+
l
3
)
(
23
)
F
f
=
F
1
·
η
(
24
)
l
3
(
θ
)
=
c
·
sin
(
θ
)
(
25
)
l
2
(
θ
)
=
l
5
+
Stroke
·
cos
(
θ
)
(
26
)
F
1
=
(
F
i
+
M
·
y
.
t
)
·
l
3
l
2
+
η
·
c
+
η
·
l
2
(
27
)
[0050] The force coming through the spacer (e.g., 40) wants to push the piston against the piston wall. However, this force may not be transmitted as the piston is constrained in the x-direction by the contact of the shaft. This creates a resulting moment about point B. This moment is then countered by the force, F 1 . If the piston was used in the horizontally opposed configuration there would be a resultant force on the opposite side of the opposed chamber. This would further spread the forces out reducing friction. FIGS. 19 , 20 and 21 show the respective friction torque due to gas pressure, inertia and the total combined friction torque in the ring assembly. Taking the integral of the total torque over 180 degrees shows that the illustrative disclosed embodiment does approximately 30 percent less total work.
Vibration
[0051] In modern engine development the improved control of internal imbalances in the motion of system components contributes to reduction of mechanical losses (Reference [14]). Fundamentally, better balanced engines raise less concern over material deformation, noise and vibration. This ultimately contributes to better overall performance. Traditional piston engines have inherent disadvantages in balancing due to the pistons irregular change in acceleration along their path of movement.
[0052] The disclosed exemplary system is much simpler system to analyze because all masses may be seen as rotating at a constant angular velocity about the crankshaft center or, moving in a linear sinusoidal motion through the center of the crankshaft ( FIG. 22 ). This means that the acceleration profile is also sinusoidal and can thus be perfectly offset by the same profile 180 degrees ahead in the crankshaft rotation. The result is that the moment created about the crankshaft is constant and all forces in the x and y-directions are balanced. This balance may be achieved in any engine configuration. A total of at least four sinusoidal, reciprocating, linear moving masses, a-d would need to be used to obtain optimal balance in the horizontal and vertical directions. A four cylinder engine with all pistons opposed would need no counter weights. The rotating mass due to the pistons, counterweights and crankshaft would be largely due to engine design and piston configuration. It may be shown that:
[0000]
y
e
″
=
m
e
·
(
1
2
·
r
·
ω
2
·
cos
(
θ
)
)
y
f
″
=
m
f
(
1
2
·
r
·
ω
2
·
cos
(
θ
+
180
)
)
(
28
)
x
e
″
=
m
e
·
(
1
2
·
r
·
ω
2
·
sin
(
θ
)
)
x
f
″
=
m
f
(
1
2
·
r
·
ω
2
·
sin
(
θ
+
180
)
)
(
29
)
y
b
″
=
m
b
·
(
-
r
·
ω
2
·
cos
(
θ
+
180
)
)
y
d
″
=
m
d
·
(
-
r
·
ω
2
·
cos
(
θ
)
)
x
c
″
=
m
c
·
(
-
r
·
ω
2
·
cos
(
θ
+
90
)
)
x
a
″
=
m
a
·
(
-
r
·
ω
2
·
cos
(
θ
-
90
)
)
(
30
)
x
e
″
+
x
f
″
+
x
c
″
+
x
a
″
=
0
y
e
″
+
y
f
″
+
y
b
″
+
y
d
″
=
0
(
31
)
[0053] Where the x-y origin is at the center of the larger circle, m represents mass and omega is the angular velocity of theta. The letters a-d represent pistons masses moving linearly while f and e represent the centers of mass for the offset crank and gearing components. All components are balanced.
[0054] In accordance with one embodiment, the housing can further define at least one intake valve and one exhaust valve proximate one end or at each end of the bore. If desired, the device can be an internal combustion engine wherein fuel is introduced into the intake valve during operation and combusted to drive the crankshaft. By way of further example, the device can be a pump or compressor, wherein a fluid to be pressurized by the device is introduced into the intake valve during operation. Preferably, the motion of the piston in the bore of the housing is sinusoidal.
Exemplary Pedal and Crankshaft
[0055] The purpose of the illustrative exemplary design is to convert an elliptic or vertically reciprocating motion to angular rotation. Applications include, for example, those wherein a pedal and crankshaft are powered by a person. This is most commonly used in the bicycle. The advantage of this system is in the biomechanics of the human body and may differ from person to person. By changing the length of l 1 the rider may obtain a completely circular motion in the case that l 1 is zero or a completely vertical motion in the case that l 1 is equal to l 2 . The basic geometry of this mechanism may be seen in FIG. 23 .
[0056] FIGS. 23 and 24 show l 1 as two thirds of l 2 creating the elliptical path seen in FIG. 24 . FIG. 25 shows l 1 equal to l 2 giving the pedal a completely vertical reciprocating motion. To achieve this, the central sprocket is held stationary while the outer sprocket is rigidly attached to the outer crank (l 1 ). The rotation of the two sprockets is constrained by a chain seen in FIG. 25 . This causes φ to rotate relative to θ at all times. The advantage to this system is that it allows the rider to determine the relative motion of the pedal. A longer down or push stroke may give an advantage to a circular motion allowing a faster smother pedal movement.
[0057] If desired, the subject device can instead include first and second gears (not shown) in lieu of sprockets and a chain as described above or a third idler gear (not shown) interposed between the first and second gears, wherein rotation of the first gear about the pivot point causes rotation of the second gear and the central shaft by way of the third gear. Preferably, the first sprocket and second sprockets (or gears, rollers or pulleys, described below) are of substantially the same diameter.
[0058] In accordance with a further alternative embodiment (not shown), the first crank portion can include a first roller affixed thereto in lieu of a sprocket in axial alignment with the pivot point, and wherein the central crankshaft includes a second roller affixed thereto in axial alignment with the axis of rotation. If desired, the device can further include a belt encircling the first and second rollers, wherein rotation of the first roller about the pivot point causes rotation of the second roller and the central shaft by way of the belt. Alternatively, the device can further include a third idler roller interposed between the first roller and second roller, wherein rotation of the first roller about the pivot point causes rotation of the second roller and the central shaft by way of the third roller.
[0059] In accordance with yet another embodiment (not shown), the first crank portion can include a first pulley in lieu of a sprocket affixed thereto in axial alignment with the pivot point, and wherein the central crankshaft includes a second pulley affixed thereto in axial alignment with the axis of rotation. The device can further include a belt encircling the first and second pulleys, wherein rotation of the first pulley about the pivot point causes rotation of the second pulley and the central shaft by way of the belt. If desired, the belt and pulleys can have interdigitating teeth.
[0060] In accordance with still a further embodiment (not shown), a machine is provided including a sprocket/gear/roller/pulley drive mechanism as described hereinabove. The machine can be, for example, a bicycle, a tricycle, a quadricycle, an exercise bicycle, an electric generator, a pedal taxi or a paddleboat.
[0061] The methods and systems of the disclosed embodiments, as described above and shown in the drawings, provide for drive systems with superior attributes as compared with conventional devices in the art. It will be apparent to those skilled in the art that various modifications and variations can be made in the device and method of the disclosed embodiments without departing from the spirit or scope of the disclosure. Thus, it is intended that the disclosed embodiments include modifications and variations that are within the scope of the appended claims and their equivalents. Each references mentioned herein (and below) is incorporated by reference herein in its entirety.
REFERENCES
[0000]
1 Rao, S. S. Mechanical Vibration, 1990 (Addison-Wesley, Reading, Mass.).
2 Uras, M. H. and Patterson, D. J. Measurement of piston and ring assembly friction instantaneous IMEP method. SAE technical paper 830416, 1983
3 Mcgeehan, J. A. A literature review of the effect of piston and ring friction and lubricating oil viscosity on fuel economy. SAE paper 780673, 1978
4 Ku, Y. and Patterson, D. J. Piston and ring friction by the fixed sleeve method. SAE paper 880571, 1988.
5 Taraza, D., Henein, N., and Bryzink, W. Friction losses in multi-cylinder diesel engines. SAE paper 2000-01-0921, 2000
6 Zweiri, Y. H., Whidborne, J. F. and Seneviratne, L. D. Instantaneous friction components model for transient engine operation. Proc. Instn Mech. Engrs, Vol 214, Part D, 2000, 809-824
7 Seggern, D. H. Practical Handbook of Curve Design and Generation, 1994 (CRC Press, Inc.)
8 Pukjrabek, W. W. Engineering Fundamentals of the Internal Combustion Engine, Second Edition, 1997 (Pearson Prentice-Hall)
9 Boles, M. A. and Cengel, Y. A. Thermodynamics an Engineering Approach Fourth Edition, 2002 (McGraw-Hill)
10 Zweiri, Y. H., Whidborne, J. F. and Seneviratne, L. D. Detailed analytical model of a single-cylinder diesel engine in the crank angle domain Proc. Instn Mech. Engrs, Vol 215, Part D, 2001
11 Zweiri, Y. H., Whidborne, J. F. and Seneviratne, L. D. Dynamic simulation of a single-cylinder diesel engine including dynamometer modeling and friction. Proc. Instn Mech. Enfre, Part D, Journal of Automobile Engineering, 1999, 213(D4), 391-402
12 Furuhama, S., Takiguchi, M. and Tomizawa, K. Effect of piston and piston rig designs on the piston friction forces in diesel engines. SAE paper 810977, 1981
13 Terauchi, Y., Nagamura, K. and Ikejo, K. Study on Friction Loss of Internal Gear Drives (Influence of Pinion Surface Finishing, Gear Speed and Torque). JSME International Journal Series III, Vol. 34, No. 1, 1991
14 Perera, M. S. M., Theodossiades, S. and Rahnejat, H. A multi-physics multi-scale approach in engine design analysis. Proc. IMechE Vol. 221 Part K: J. Multi - body Dynamics
15 Taylor, C. F. The Internal Combustion Engine in Theory and Practice Volume 2: Combustion, Fuels, Materials, Design Revised Edition, 1985 (The M.I.T. Press)
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The disclosure provides new crankshaft configurations for various purposes. In one embodiment, new crankshaft configurations are provided that are believed to be particularly suitable with internal combustion engines. Exemplary mechanisms convert a linear sinusoidal motion to a rotational one. In another embodiment, new crankshaft configurations are provided that are believed to be particularly suitable with manually operated drive systems, such as on bicycles. Exemplary mechanisms convert elliptic or linear reciprocating motion into angular motion.
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CROSS-REFERENCE TO RELATED PATENT APPLICATION
[0001] The present application is a continuation in part of U.S. Ser. No. 09/413,808 filed Oct. 6, 1999, which claims the benefits under 35 U.S.C. 119(e) of provisional patent application serial No. 60/103,285, filed Oct. 6, 1998. This application incorporates by reference, as though recited in full, the disclosure of copending application Ser. No. 09/412,808 and provisional application 60/103,285.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention discloses a geotextile resistant to insect penetration, having application in areas such as yards, playgrounds and home protection.
[0004] 2. Brief Description of the Prior Art
[0005] Ants, and other insect, colonies established in lawns, playgrounds and parks, or other recreational areas can cause damage, attack people and animals and make the use of outdoor areas less enjoyable. The imported fire ant has been a problem for years in the southeastern United States and has systematically moved north and west. In an attempt to control their population, fire ants are treated extensively and regularly with various pesticides. Solutions to the problems, which are alternative to pesticide treatment is sought which can reduce or eliminate the problems caused by fire ants and other pests, and which solutions are long term in effect do not have high costs associated with them.
SUMMARY OF THE INVENTION
[0006] Because of their lower manufacturing costs, nonwoven fabrics can be economically used as barriers in high value landscapes to keep soil insects within subsurface treatment zones, thereby improving the efficacy of treatments. In addition, subsurface soil barriers may create a non-preferred habitat, which results in the migration of pest to less sensitive areas. For example, fire ants will either build shallower, more easily treated (or easily frozen in frigid weather) nests, or establish nest sites in areas without the fabric. Installing the fabric in playgrounds and schoolyards would reduce insect colonization and pesticide input in these sensitive areas. The fabric placed under mulch in landscape beds and trees or shrubs can have the added benefit of preventing weed emergence.
[0007] The needlepunched nonwoven synthetic material prevents the insects from burrowing through by presenting the insects with overlapping, randomly placed fiber layers. The insects attack the ends of the fibers, going from fiber to fiber until they are trapped within the fabric layers. Water permeability is enabled while preventing insects from penetrating the material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The advantages of the instant disclosure will become more apparent when read with the specification and the drawings, wherein:
[0009] [0009]FIG. 1 is a chart indicating the various properties of materials for use in the disclosed fabric;
[0010] [0010]FIG. 2 is a cutaway side view of the material being used to cover an area of land;
[0011] [0011]FIG. 3 is a cutaway side view of the material laid out to cover a foundation;
[0012] [0012]FIG. 4 is a cutaway side view of the material covering the foundation and house;
[0013] [0013]FIG. 5 is a flow chart of the method of using the material to wrap a house; and
[0014] [0014]FIG. 6 is a flow chart of them method of using the material to cover an area of land.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Ants and other insect pests that establish nests in lawns, playgrounds and parks, or other recreational areas can cause damage, attack people and animals and make the use of outdoor areas less enjoyable. The imported fire ant has been a problem for years in the southeastern United States and has, recently, moved north info Virginia and west to California. In an attempt to control their population, pesticides have been used extensively and regularly, however affordable alternatives are sought that are long term in effect and environmentally safe. Another pest, termites, which attack wooden structures in most areas of the US, creates extensive damage to public and private property. The termite and the fire ant problem are most severe in the Southeastern US because of weather conditions favorable to their survival. According to Commerce Department statistics, the South is by far the largest market for housing in the US. Although the nesting habits of some insects, including termites and ants, make the application of geotextile technology attractive, the prior art problem lay in finding a mechanism to prevent the insects from eating their way up, through the fabric while maintaining proper water drainage control above the fabric.
[0016] Geotextiles are water permeable textiles frequently used in conjunction with soils or rocks as an integral part of man made projects, providing cost effective substitutes or enhancements to other materials in civil engineering projects. The area of geotextile fabrics has been a strong part of the American textile industry since the 1970's and few textile markets have recently enjoyed the tremendous growth that the geotextile market has experienced. The nesting habits of insect pests, such as imported fire ants, is now seen to make the application of geotextile technology a logical and useful solution to their control. Application of a successful geotextile material to prevent infestation of pest insects such as ants would be environmentally beneficial by reducing, or eliminating, the need for pesticide use. Although the area of geotextile fabrics offers an environmental acceptable solution to the problem of insect control, such as fire ants, this technology has not, to date, been used to combat infestations of insects in lawns or recreational areas. The primary reason for the absence in this application is the ability of ants, and other insects, to eat through many materials. Therefore, the construction and composition of geotextile required for such an application differs considerably from that previously incorporated in prior art uses.
[0017] Presently geotextiles have been used in the areas of separation, filtration, drainage, and reinforcement. Separation places a geotextile between dissimilar materials so that the integrity and function of both materials can remain intact or be improved. Geosynthetic filtration fabrics allow flow of liquid across the surface while limiting soil loss. The relationship between allowing heavy water flow or limiting soil passage depends on the application and the construction site. The drainage or transmission function refers to passage of water within the plane of the fabric. Geotextiles used for reinforcement improve the structural stability of soil. The textile, in all cases, improves the shear strength of the system and absorbs tensile stresses.
[0018] The use of fabrics in the building and housing construction industry in the US is now limited to house wraps, some soil reinforcement and decoration of housing interiors. Housing contractors use Styrofoam board material or woven steel mesh to line house foundations to prevent termite access to the foundation. Although the woven steel mesh is successful in preventing termites from entering a structure, both production and installation is expensive. Textile use to prevent ant or termite invasion is generally limited to wrapping the root systems of the plant in nursery pots. Textile sheets have also been used to replace plastic for garden and walkway weed prevention, providing the advantage of drainage while reducing the weed growth.
[0019] Depending on the method used to construct the fabric and the intended end use, the geotextile ranges in weight from approximately 3.5 to 60 ounces per square yard. Of the three methods used for fabric construction, weaving is the slowest and most labor intensive, requiring at least four (4) processes to produce the fabric. Knitting is one order of magnitude faster for fabric production, however geotextiles fabrics require the same numbers of processes as are needed in weaving. Nonwoven is two orders of magnitude faster in full-scale production than weaving and needs only two or three processes for fabric production. A nonwoven is as a textile structure consisting of a consolidated mat, or web, of fibers produced by bonding or entangling fibers or filaments through mechanical, chemical or thermal means. The properties of nonwoven fabrics lend themselves most easily to their application for the prevention of ant and other insect infestation in subterranean in the web.
[0020] Needlepunching is the most frequently employed method of nonwoven fabric consolidation, providing a mechanical method of web bonding to interlock fibers and tufts of fibers by entanglement and fiber friction. Entanglement of the fibers occurs as barbed needles in a needlepunch machine (or needle loom) penetrate the fiber batt to carry tufts of fibers from one layer to another without disentangling the fibers when needles are withdrawn. The structure of the needle determines needling efficiency, quality of finished product, and physical characteristics of the fabric. The needle blade penetrates the fiber web and, with the aid of the barbs, entangles the tufts of fibers. The barb transports and entangles tufts of fibers through the batt. To accommodate synthetic fibers, barbs were designed with rounded edges, best suited for products manufactured from delicate or fine fibers, and where excessive fiber damage would be detrimental to the useful life and tensile strength of the felt.
[0021] For a given needlepunch density, a smaller barb size, with less capability for fiber transport, would produce a fabric of greater thickness and loftiness. Such a fabric structure could provide a more difficult barrier for burrowing insects to breach, but the fabric tensile strength suffers as a result. Lowering the amount of barb “kick-up” and increasing the frequency of needle penetrations per square inch achieves higher tensile strengths as well as a smoother fabric surface but it decreases general permeability. Regular barb spacing provides uniform interlocking of the felt from top to bottom while a medium spaced barb, about 0.05 mm per barb closer, can carry more fibers per stroke with a lower penetration depth than the regular spaced barb. Close barb spacing decreases felt thickness.
[0022] The advantage of using close barb spacing is that all the barbs enter the felt with a relatively small amount of penetration depth as compared to a regular spaced barb. Generally, close spaced barbed needles are used for maximizing needling efficiency with minimal needle penetration. Minimal penetration is essential in high throughput loom speeds, where needle deflection is a concern, because less penetration means fewer chances of encountering resistance in the web. Reduced barb spacing produces fiber bundles distributed closer together with a denser felt as the net result.
[0023] Nonwoven fabrics are also unique because their production lines can produce random and more easily controlled void spaces in the fabric. In knits and wovens, voids are determined entirely by the size, and stiffness of the constituent yarns. Further, since nonwovens are produced directly from fibers, they can easily be produced according to the desired thickness. The controllable properties of nonwoven fabrics lend themselves most easily to their application for the prevention of ant and other insect infestation in subterranean environments.
[0024] The most common types of web formation in nonwovens are air-laid, wet-laid, or carded. Wet-laid, or extruded web formation, will not produce maximum results in insect resistance, while air laid and carded both provide optimum prevention. Wet laid nonwovens are very thin and have a tissue-like fabric character and are not as tough as dry formed fabrics. These nonwovens are more easily torn and provide a very flat, relatively uniform surface for the insects to attack by chewing. A web oriented in only one direction will be uniform, but lack strength in other directions because it does not have omnidirectional (isotropic) fiber orientation, as well as eliminate the zigzag fiber orientation to inhibit insect penetration. Fibers in the web are consolidated either by high velocity water jets (hydroentanglement), high temperatures (thermal bonding), barbed needles (needlepunch) or other methods bonding to secure the fibers in the web.
[0025] All geotextiles are characterized by performance and index tests. A performance test attempts to predict geotextile performance in the environment of intended use; an index test measures a physical property of the geosynthetic without consideration of specific intended use. Tensile properties are evaluated in geotextiles to determine effects of stress and strain forces on the fabric. Tensile performance is measured by ASTM specified standards using constant rate of elongation tests including: grab breaking load and elongation test, wide strip test, and performance strength by wide/strip tensile method. Puncture and burst resistance is measured by a rod puncture test and diaphragm-bursting test respectively. Tear resistance can be measured using the trapezoid tear test.
[0026] To examine the feasibility of applying specially constructed nonwoven geotextile fabrics to prevent or inhibit infestation by insects, an initial determination was the most effective, commercially available fiber to use for the construction of the fabric to prevent penetration. This was determined by considering several factors. The minimum threshold level of fabric density for each component fiber type to prevent penetration of the fabric by fire ants was critical. The effects of the number of needle punch density (consolidation technique for fabric production) of a nonwoven fabric on penetration of the fabric by fire ants were then taken into consideration, as well as the fabric degradation caused by soil and mulch. These foregoing factors were considered, along with material cost, to determine the optimum material and cost associated with the construction this fabric.
[0027] Permeability and opening size are important considerations for when using the nonwoven for nesting preventing due to the drainage or filtration considerations. Permeability is defined as the flow rate, under a differential pressure, of a fluid (usually water) through a geotextile. For application to insect penetration inhibiting fabrics, the fabric must have pore (opening) sizes that are too small and too discontinuous to permit penetration by insects such as ants. At the same time, the fabric must allow an acceptable flow rate of water through it to drain standing water from its surface where it is applied. The required permeability will be influenced by the end use and should follow the site required standard industry requirements as known in the geotextile field. Definitions of the types of geotextiles known in the industry are defined in the Dictionary of Fiber and Textile Technology , Pgs. 71-72, Hoechst Celanese Corporation, 1989, which is incorporated herein as though cited in full.
[0028] The size of openings in a fabric can be compared based on the apparent opening size test (AOS) or by photomicroscopy. The AOS test requires the use of beads of various diameters to be applied to the surface of the fabric to fill pore opening in the fabric surface. AOS is most widely accepted for woven fabric rather than for nonwovens.
[0029] A critical step in manufacturing any fabric is selection of fiber. Some fiber types, which can be considered for such a synthetic geotextile product, are also environmentally desirable because they can be produced wholly or substantially from recycled materials such as plastic soft drink bottles or plastic grocery bags. Polyester, polypropylene, polyethylene and polyamide are example materials for use in the disclosed application and other similar materials, commonly applied to subterranean applications, can also be incorporated herein. The flexible, synthetic materials must be resistance to soil degradation, microorganism growth and have tensile characteristics sufficient to prevent tearing or puncturing during the specific installation. Any of the fibers used should be water resistant and have a long life to make them ideal for insect control application.
[0030] Polypropylene, as is well known in the art, is polymerized from the propylene monomer in the presence of an organo-metallic catalyst. In the reaction, the catalyst breaks the secondary bond and causes a chain reaction to produce the polymer. The properties of polypropylene, such as melting point and density, are dependent on the placement and regularity of placement of the methyl (CH3) groups. Atactic describes the structure in which the placement of methyl groups is irregular. Isotacticity signifies that the methyl groups are on one side of the chain, and syndiotacticity indicates that methyl placement alternates regularly from side to side. The isotacticity index, which is the percentage of isotactic polypropylene in the polymer, is always higher than 90% for commercial polypropylene.
[0031] The chart of FIG. 1, comparing the properties of polypropylene, polyester and polyamide, shows that the melting point of polypropylene is about 150° F. lower than that of polyester. The chart is taken from “ Textile World Manmade Fiber Chart 1994” by McAllister Isaacs III. Textile World, 1994. This means that the energy required to thermally bond polypropylene is less than the energy required to bond the same amount of polyester. Polypropylene is approximately 52% lighter than polyester's specific gravity of 1.38 g/cc.
[0032] The following tests at Auburn University involving both the Department of Entomology and the Department of Textile Engineering illustrate that certain constructions of nonwoven polyester fabrics are impenetrable by fire ants and that not all nonwoven polyester fabrics will resist penetration by the ants. Imported fire ants were use as the initial test insect, because of the need and interest in controlling this pest, and their ability to breach barriers (e.g. roof linings, electrical insulation).
[0033] The dual tests were performed under identical conditions, with and without water present in the bag. All of the following tests were performed by placing the ants in bags using material described specifically in each Example. The nonwoven fabric was produced using a medium barb and about 550 punches per square inch. Both nonwoven fabrics were made from 1.5 denier polyester fibers, approximately 1½″ in length and needled with a top punch needling process using lightweight felting needles. As no food was placed in the bag during any of the tests, the colony was forced to chew through the bag to get to food. The bags were manufactured to prevent a small colony (>750 worker ants) from escaping.
EXAMPLE I
[0034] An extruded nonwoven, such as Tyvek® was used to form a bag which was sealed to prevent the ants escape. The ants penetrated the extruded nonwoven within two (2) hours.
EXAMPLE II
[0035] A bag was formed using a nonwoven polyester fabric of 130 g/m 2 (4 oz/yd 2 ) and the ants were placed inside the bag without access to water. The colony was unable to penetrate the 8 oz. fabric and most died within 14 days.
EXAMPLE III
[0036] The ants were placed in a duplicate bag of the foregoing 4 oz. with water, although this placed the fabric at a disadvantage. After 23 days, the ants were still unable to chew through the 8 oz. fabric.
EXAMPLE IV
[0037] The colony was sealed into a bag of 85 g/m 2 (2.5 oz/yd 2 ) nonwoven polyester without water. The ants were unable to chew through the lighter weight polyester without the presence of water.
EXAMPLE V
[0038] The colony was sealed into a bag of 85 g/m 2 (2.5 oz/yd 2 ) nonwoven polyester water. In contrast to the 8 oz. material, the lighter weight polyester fabric was chewed through within six (6) days, which indicates that there is a fabric density threshold above which fire ants cannot penetrate.
EXAMPLE VI
[0039] A termite infested small wooden structure was lifted from its resting place to ensure that a termite colony was directly underneath. Several days later the structure was again lifted to ensure that the colony had not left due to the initial disturbance. A sheet of fabric (2.5 oz/yd 2 ) was placed between the termite colony and the base of the wood structure, but did not wrap around the sides. The wood structure was sunken approximately {fraction (1/3)} of the depth of its base. One week later, the colony had left and there was no termite activity.
[0040] Initial test results have shown that the lighter weight material will retard the burrowing of fire ants through the fabric when water is present. In the absence of a water source in the fabric case, however, ants are unable to escape through the lighter, 2.5 oz., fabric. The heavier fabric was impenetrable to the insects even when water was present for them inside the fabric case. The one exception to the results for the heavier fabric sample occurred because of a fabrication defect in the fabric bag side seam. This reinforces the inability of the colony to eat through the 4 oz fabric. The results show that there is a fabric density threshold of about 4 oz. per square yard above which fire ants cannot penetrate a fabric without starving first. This indicates that in earth based colonies, the ants would chose to abandon an attempted nesting site a distance from food or water rather than die of dehydration or starvation. Nesting sites established above the geotextile layer are too shallow to support the colony in extreme heat, cold or temporary flooding from heavy rains. Termite penetration patterns are similar to that of ants.
[0041] To provide new construction with maximum protection against invading insects, once the foundation area 26 is cleared, the nonwoven fabric 20 , as illustrated in FIGS. 3 and 5, is placed within the foundation area 26 . The foundation 24 is then placed on top of the fabric 20 and the house 26 is constructed, as seen in FIG. 4. The fabric is then wrapped over as much of the house 26 as desired and the structure completed. In FIG. 3, the fabric 20 covers only the foundation, while in FIG. 4 additional fabric 20 is added around the house 26 . Although FIG. 3 illustrates the extra fabric pulled away from the foundation 24 , the material can be cut to extend only slightly beyond the foundation 24 and additional added to complete the coverage of the foundation 24 . It should be noted that the disclosed fabric can be used with slab foundation as well as houses having a basement, with any differences in the installation being obvious to those skilled in the art.
[0042] When used to protect yards, playgrounds, etc. from ants, the ground is dug down within the desired periphery and the fabric placed on the cleared surface. The depth to which the soil is removed is a matter of landscaping and/or preferences, with the average being at least 6 to 8 inches below the placement of the surface. In instances where shrubs are being planted, the depth beneath the shrub can be greater, for example 18 inches, with the depth gradually decrease until the it reaches 6 to 8 inches. In applying the fabric 20 to the ground 12 , the strips of fabric 20 must be overlapped to some extent. The overlap can depend upon potential infestation, end use and cost. An overlap must be present to prevent insect penetration and a minimum of ⅛ inch is preferable. Once the excavated ground 12 covered, the topsoil 14 is replaced and/or added.
[0043] The non woven construction of the disclosed fabric prevents root penetration, thereby requiring planning for large trees or shrubs. Since the tree or shrub will die without sufficient root expansion, a hole must be cut within the fabric and a hole dug, beneath the access hole, within which to plan the tree. The area would then need to be treated with insecticides to prevent insect infestation.
[0044] When large areas of land are being protected and the insects trapped beneath the fabric, food deprivation is relied upon to prevent nesting. For the fabric to act as an effective barrier, the viscous energy dissipated by the chewing ant or insect exceeds must energy supply. When the ants must travel too far to transport sufficient food to build the colony, colonies are confined to the periphery of the protected areas, therefore requiring the areas of greatest protection to be along the periphery of the covered area. When covering large areas, such as housing developments, heavier fabric can be used along the periphery while thinner material can be used toward the center of the area. Thus, once the total area is determined 60 and the top soil removed 62 , the area to be covered is divided into two sections; an outer section and an inner section. The outer section, which extends from the outer periphery toward the center a distance greater than the insect would travel to set up a colony is covered with a first, or heavier, fabric 64 . The inner section would cover the remaining interior area and covered with a second, or lighter, fabric 66 . The top soil is then replaced over the entire area 68 . The distance an insect would travel would be known to those versed in entomology. The minimum fabric thickness required is determined by the fracture toughness of the fibers and on the type and thickness of the cross-section.
[0045] When food is not limited, the minimum thickness will depend on the behavior of the insect group, which often emulates the behavior of corrosive viscous liquids. On a micromechanical scale, the length of the mandible moment arm, the acuteness of the mandible bite surface wedge and the fracture toughness of the surface being attacked determine the corrosive action.
[0046] The nonwovens prevent insect penetration due to the insect's instinct to attack an end of fiber. In a woven, there are viewer ends and a multiple of openings. In a nonwoven the insects see only a multitude of short, jumbled fibers. The each fiber layer forming the nonwoven provides a multiplicity of attack points created by the inherent fiber orientation and characteristics. The insects cannot easily work their way directly through the fabric, but rather travel the zigzag path of the fibers forming the nonwoven and getting lost in the cross laid structure. Since the fiber structure within the material is on a predominately horizontal plane, the insects following the fibers travel horizontally vs. vertically, or from underside to topside, of the material. From an insect perspective, they see only fiber ends, not a flat sheet. Materials, such as Tyveck®, fail to retain insects due to the presentation of a flat sheet rather than the high population, randomly oriented jumbled fiber presentation of the nonwoven. The presentation of a jumble of randomly oriented fibers is eliminated once a bonding material is introduced making it critical, to obtain maximum results, for the material to be only needlepunched. Additional penetration resistance is obtained by increasing the fiber diameters to be equal to, or greater than, the diameter easily accepted by the majority of the insect's mandibles. The diameter would vary in accordance with the type of insect and can, in some instances realistically, be directed only to the “average”. At some point the diameter sizing would affect adversely the cost and characteristics of the fabric.
[0047] Mathematically, this action can be modeled by the formula used to describe containers for extremely corrosive or hot liquids such as that described by the viscous dissipation formula
ρ ( u 2 ) t = - u ∂ P ∂ z + ρ f ( u ) - Q visc
[0048] Where:
[0049] ρ=liquid/organism density;
[0050] P=pressure;
[0051] D=expression for a first derivative in Calculus;
[0052] u=liquid/organism internal energy;
[0053] Dt=derivative with respect to time;
[0054] □=partial derivative;
[0055] z=fabric thickness direction;
[0056] ρf=ρ times f(u) where f(u) is a function of u;
[0057] Qvisc=viscous dissipation loss
[0058] In cases where Qvisc remains greater than D(u2)/Dt, the insects will not be able to penetrate the fabric before they die.
[0059] Successful use of nonwoven geotextiles as a barrier to imported fire ants, suggests their use in other applications such as termite barriers for structures, confining soil insect pests such as mole crickets and white grubs to treatable subsurface soil zones. Other than prevent fire ant nesting, the geotextile can be used for fire ant proof wraps for root balls for nurseries within the imported fire ant quarantine, and seals for electrical switch boxes. All these applications could reduce or eliminate pesticide applications.
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The needlepunched nonwoven synthetic material prevents the insects from burrowing through by presenting the insects with overlapping, randomly placed fiber layers. The insects attack the ends of the fibers, going from fiber to fiber until they are trapped within the fabric layers. Water permeability is enabled while preventing insects from penetrating the material.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority as a divisional application from U.S. patent application Ser. No. 12/508,562 filed 23 Jul. 2009, now issued as U.S. Pat. No. ______ on ______, 2011.
FIELD OF THE INVENTION
[0002] The present invention relates generally to thermal insulation. More particularly, the present invention relates to insulative padding and related insulation kit for reducing thermal transfer from pipe couplings, valves, and other exposed conduit areas.
BACKGROUND OF THE INVENTION
[0003] In the field of thermal insulation, numerous attempts have been made to insulate conduits to alleviate heat transfer and thereby reduce related energy costs. Such heat transfer may be due to heat loss from heat bearing systems (e.g., steam distribution pipes) or heat gain to cold materials (e.g., chilled water distribution pipes). This is most common within industrial, institutional, and/or commercial settings that include thermal energy distribution systems. Straight sections of pipes within the distribution system are typically completely encased, often permanently, within a continuous insulation material suitably chosen for high heat tolerance. However, such systems often include a variety of pipe components and equipment including, but not limited to, flanges, valves, valve stems, and steam traps. These components often require some level of maintenance. In turn, this requires some level of physical access to the particular component necessitating removal of the thermal insulation materials.
[0004] Removable/reusable insulation blankets, in the form of clamshells, have been used to insulate such components requiring periodic and/or frequent access. However, most clamshell type of removable/reusable component insulation devices are designed to be installed by skilled insulation installers and are generally difficult to re-attach by personnel unskilled in pipe insulation due in large part to wire lacing which is normally cut and discarded during removal. Accordingly, once a maintenance issue occurs at the component site, it is common within industrial, institutional, and/or commercial settings to see an insulation device lying unused nearby. Several such flawed attempts have been identified among previous related devices.
[0005] One previous attempt at providing pipe insulation is found in U.S. Pat. No. 4,112,967 issued to Withem on Sep. 12, 1978 for a weatherproof insulated valve cover. The Withem valve cover is for a pipeline and provided a flexible multi-layered construction shaped to conform to valves having stub pipe-type valve stem housings. The valve cover included a waterproof outer layer of Herculite or the like with one of the inner layers being insulation. The cover was easily removable by virtue of releasable fasteners to permit access to the valve for maintenance.
[0006] Another previous attempt is found in U.S. Pat. No. 4,207,918 issued to Burns et al. on Jun. 17, 1980 for an insulation jacket. The Burns et al. device is an insulation jacket for use as a valve cover. The jacket includes a body portion having a central section and two lateral sections. Each of the lateral sections includes an inboard and outboard belt and each of the belts extends along each of the lateral sections. The ends of each of the belts are adapted to interlock whereby the insulation jacket may be securely fastened around a valve casting.
[0007] Yet another attempt is found in U.S. Pat. No. 4,556,082 issued to Riley et al. on Dec. 3, 1985 for a removable thermal insulation jacket for valves and fittings. The Riley et al. device is a unitary flexible thermal insulation jacket for valves and pipe fittings. The jacket is universal in the sense that it properly fits valves and pipe fittings of various manufacturers. It is secured snugly to a valve or pipe fitting by attached draw cords, rendering the jacket readily removable and reusable.
[0008] Still another attempt is found in U.S. Pat. No. 4,925,605 issued to Petronko on May 15, 1990 for a method of forming a heat foam insulation jacket. Petronko discloses a unitary removable and reusable jacket for the thermal insulation of pipe components. The fully-formed generally-rectangular jacket is composed of three layers: a heat and water resistant outer fabric layer, a hardened rigid-cell polyurethane middle layer, and a thin flexible heat-shrinkable plastic inner layer. The inner and outer layers are joined together by perimeter seams and a transverse center seam which forms two pockets adapted to contain the polyurethane foam middle layer. The inner and outer layers are formed at time of manufacture while the middle layer is formed during the application process. During the application process, an exothermic chemical reaction is generated by the combination of the chemicals polyol and isocyanate which are inserted between the inner and outer layers through holes contained in the outer layer, to form a rapidly expanding and hardening rigid cell polyurethane foam middle layer. During the application of the jacket around the accouterment, in response to the exothermic chemical reaction, the inner layer shrinks to fit the exact shape of the underlying pipe, as does the rigid-cell middle layer which is being formed. When installation is complete, the jacket may be removed and reused by using pressure to “crack” the transverse seam dividing the middle layer into two pockets which are positioned on opposite sides of the accouterment.
[0009] Yet still another attempt is found in U.S. Pat. No. 5,025,836 issued to Botsolas on Jun. 25, 1991 for a pipe fitting cover for covering pipe fitting. The Botsolas device discloses a rigid or semi-rigid cover for installation over an insulated pipe fitting. The cover is pre-cut in the geometric design that enables it to conform to the shape of the pipe fitting when installed.
[0010] Still another attempt is found in U.S. Pat. No. 5,713,394 issued to Nygaard on Feb. 3, 1998 for a reusable insulation jacket for tubing. The Nygaard device is a reusable single layer insulation jacket for splicing and termination of industrial tubing, fittings, and valves carrying extreme hot and cold materials comprises a fiberglass mat. The mat is of a width as to completely wrap the tubing, fitting, or valve and overlap itself. Releasable fastening means securely hold the mat in place to insulate the tubing, fitting, or valve from fire and to prevent an individual from otherwise being burned from contacting the tubing, fitting, or valve.
[0011] Further still another attempt is found in U.S. Pat. No. 5,941,287 issued to Terito, Jr. et al. on Aug. 24, 1999 for a removable reusable pipe insulation section. The Terito, Jr. et al. device discloses a removable reusable insulating unit suitable for insulating exposed pipe sections forming components of an insulated pipe system. The unit includes a hollow body constructed of an insulating material which is capable of being easily cut the hollow body defining an interior and an exterior of the insulating unit. The interior is sized to envelop an exposed pipe section on an insulated pipe system. The body has at least two pipe receptor areas and each is sized to accommodate a component of an insulated pipe system.
[0012] The competing requirements of maintaining an enclosed insulation layer yet enabling physical access for component maintenance has led to a variety of removable insulation devices to reduce thermal losses. The common aspect of such existing removable insulation devices is that they are designed with a particular component in mind and shaped accordingly. That is to say, a typical removable insulative device for example designed for a valve is shaped in such a way that the device is rendered unsuitable for a flanged coupling or a steam trap. This tends to drive up costs to the end user. Oftentimes, an industrial, institutional, and/or commercial user will be required to purchase several different shapes and sizes for the variety of components found within their system. This can be an unwieldy and costly solution.
[0013] It is, therefore, desirable to provide an insulation device that is versatile, cost-effective, and reusable.
SUMMARY OF THE INVENTION
[0014] It is an object of the present invention to obviate or mitigate at least one disadvantage of previous insulation devices.
[0015] The present invention provides a versatile insulation in the form of a segmented insulative device. Moreover, the segmented insulative device lends itself to quick customization on-site, rather than requiring costly off-site manufacture or pre-assembly and subsequent quick installation on the pipe component requiring thermal insulation. The segmented insulative device is designed for versatility provided by the device's embodiment within an installer's kit. The kit to fabricate the segmented insulative device includes a large sheet of segmented insulation, a roll of reusable fastening tape (e.g., two-sided hook-and-loop type such as Velcro® straps), a cutting mechanism (e.g., scissors or retractable razor cutter) for cutting suitably-sized portions of both the segmented insulation sheet and the reusable fastening tape, and a fastener (e.g., stapler or similar fastening means) to connect a section of the reusable fastening tape to the custom-cut section of segmented insulation. A stapler can be used to attach the hook-and-loop tape to the insulative device to facilitate installation and so the two do not become later separated.
[0016] In a first aspect, the present invention provides a segmented insulative device including: a first layer and a second layer each formed from a flexible material, the flexible material being resistant to moisture and heat; an inner layer of flexible insulation held between the first and second layers by way of stitching, the stitching forming a cut-site for separating the segmented insulative device into multiple sections; and one or more fastening mechanisms for securing one or more of the multiple sections to a component of a thermal distribution system.
[0017] In a further embodiment, there is provided a kit for on-site fabrication of a segmented insulative device, the kit including: a sheet of segmented insulation capable of separation into multiple sections; a reusable fastening tape capable of removably securing one or more of the multiple sections upon a component of a thermal distribution system; a cutting mechanism capable of separating the sheet of segmented insulation into the multiple sections and resizing the reusable fastening tape; and a fastener such as a stapler capable of readily affixing the reusable fastening tape to a corresponding one of the multiple sections at the site.
[0018] Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Embodiments of the present invention will now be described, by way of example only, with reference to the attached Figures.
[0020] FIG. 1 is an illustration showing one embodiment of the kit components in accordance with the present invention.
[0021] FIG. 2A illustrates a standard sized sheet of segmented insulation and detailing sewing patterns in accordance with the present invention.
[0022] FIG. 2B is a cross-section taken across line 2 B- 2 B in FIG. 2A showing composite layering.
[0023] FIG. 3A is an illustration showing the segmented insulation sheet cutting step using the kit elements as shown in FIG. 1 .
[0024] FIG. 3B is an illustration showing the fastening tape cutting step using the kit elements as shown in FIG. 1 .
[0025] FIG. 3C is an illustration showing the fastening tape connection step using the kit elements as shown in FIG. 1 .
[0026] FIG. 3D is an illustration showing the fastening tape tab-creation step using the kit elements as shown in FIG. 1 .
[0027] FIG. 3E is an illustration showing three custom assemblies of differently-sized segmented insulative devices in accordance with the present invention.
[0028] FIGS. 4A through 4E illustrate the step-by-step, on-site installation of the three differently-sized assemblies shown in FIG. 3E as applied to a valve component.
DETAILED DESCRIPTION
[0029] Generally, the present invention provides a segmented insulative device and related kit for insulating certain serviceable components of a thermal energy distribution system. Although the invention will be described in terms of insulation in high temperature settings, it should be understood that the present invention is equally useful and suitable for insulating against heat loss from heat bearing systems (e.g., steam distribution pipes) or heat gain to cooling systems (e.g., chilled water distribution pipes). The present invention provides a versatile, reusable, and cost-effective insulative device useful for a variety of pipe serviceable components and equipment including, but not limited to, flanges, valves, valve stems, and steam traps. During typical maintenance of such components, the present invention ensures easy physical access to the particular component.
[0030] With reference to FIG. 1 , there are illustrated the kit elements 10 , 11 , 11 a , 12 , and 13 in accordance with the segmented insulative device. The kit shown is used by an installer to fabricate the segmented insulative device on site and typically within an industrial, institutional, and/or commercial setting. The inventive kit includes a standard sized sheet of segmented insulation 10 , a supply (e.g., roll 11 ) of reusable fastening tape 11 a , a cutting mechanism 12 , and a fastening device 13 . More specifically, the supply of reusable fastening tape is a roll 11 of suitably dimensioned (e.g., 1″ to 2″ wide and 10′ to 20′ long) two-sided hook-and-loop type fastening tape 11 a such as, but not limited to, Velcro® straps with the hooks on one side and the loops on the other. By use of the term “reusable,” it should be understood that the tape 11 a is self-sealing or self-adhering in such a manner that it can be fastened, unfastened, and refastened many times over.
[0031] The cutting mechanism 13 may be a pair of scissors, retractable razor cutter, utility knife, or any similarly durable cutting device suitable for cutting both the supply of fastening tape 11 a and the sheet of segmented insulation 10 . The fastening device 13 can be a stapler, rivet gun, or any similarly durable fastening device suitable for connecting a section of the reusable fastening tape 11 a to a custom-cut section of segmented insulation 10 . For illustrative clarity, a specific stapler 13 , pair of scissors 12 , and roll of hook-and-loop tape 11 a are shown in FIG. 1 though any suitable substitutions may be made for these particular kit elements without straying from the intended scope of the present invention.
[0032] With regard to FIGS. 2A and 2B , detailed illustrations of the segmented insulation are shown. FIG. 2A is a top view of a standard sized sheet 20 of the segmented insulation. The sheet 20 of segmented insulation resembles in some regard a quilted blanket in that uniform squares or rectangles are formed in a grid pattern across the sheet surface. Although a particular sized sheet is shown having six grids in width and twelve grids in length, it should be readily understood that any particular width and length may be produced without straying from the intended scope of the present invention.
[0033] Typically, the whole sheet 20 would be provided within the kit in a rolled up fashion. Limiting factors in terms of whole sheet dimensions may include the length and weight of any given rolled sheet of segmented insulation. Indeed, smaller rolls may be less difficult for an installer to carry through cramped quarters among thermal piping, though larger rolls may afford the installer more sizing variations. Accordingly, ease of use and portability are factors in determining a standard size for the rolled sheet of segmented insulation and such standard may vary according to any given industrial, institutional, and/or commercial application. FIG. 2A is therefore only one example of a standard size such that the sheet may alternatively be 4′×8, 2′×8′ or any desired dimension. When considering the whole sheet and the given weight constraints for any particular application, it should also be understood that, for example, a 2′×16′ sheet would weigh the same as 4′×8′. Therefore, it should be readily apparent that the whole sheet of segmented insulation may be provided in a variety of standard sizes.
[0034] With regard to FIG. 2B , a partial cross section is illustrated from the view taken along line 2 B- 2 B in FIG. 2A . The composite layering of the segmented insulation is visible here such that a middle layer 201 of insulation is sandwiched between two outer layers 200 of material that may be selected from heat resistant or heat and moisture resistant material. In practice, the two outer layers 200 would be formed from heat resistant material and either one or both layers may be coated with a moisture resistant coating depending upon the given implementation—e.g., a steam pipe implementation within a damp environment may require would both layers 200 to be moisture and heat resistant whereas a steam pipe implementation within a generally dry environment may only require the layer adjacent the steam pipe to include moisture resistance. Thus heat and moisture resistance may vary in regard to the given layer (i.e., “inner” or “outer” exposure) and related implementation without straying from the intended scope of the present invention.
[0035] The insulation may be any suitable insulative material including, but not limited to, fiberglass, aramid, silica, aerogel, or any other flexible insulation material. In the instance of fiberglass, suitable fiberglass insulation for the middle layer 201 can include a fiberglass density of between 1 and 2 pounds per cubic foot and may be needled or bonded so as to maximize its insulation value. The outer layers 200 of moisture and heat resistant material may be fabricated from any flexible material suitable for continuous exposure to temperatures up to and exceeding 500 degrees Fahrenheit. The outer layers 200 can include a base fabric capable of continuous use at 500 degrees Fahrenheit having uncoated weights ranging between six and sixty ounces per square yard. Such base fabric may be, but not limited to, fiberglass material. As well, such base fabric may be coated with suitable heat resistant materials that may include, but are not limited to, high temperature coatings of heat resistant rubbers or silicone compounds.
[0036] With further regard to FIG. 2B , there are areas visible that are of reduced thickness 20 a . Such thinner areas 20 a are formed by the parallel rows of sewing thread 20 b . This creates the aforementioned “quilted” characteristic, and more importantly creates a cut-line guide for the installer. Such cut-line is the center point between the two parallel rows of sewing thread 20 b . In another embodiment, a third sewn line may be provided at the center point between the two parallel rows of sewing thread 20 b such that three rows of stitching are actually provided. In this manner, the cut-line would be the center stitching line. Preferably, an installer would cut along such center point in the field. However, the sewing thread 20 b will remain intact and prevent loss of the flexible insulation 201 from between the two outer layers 200 so long as the installer cuts between the parallel rows of sewing thread 20 b . That is to say, minor deviation from a cut along the center point is tolerable without straying from the intended scope of the present invention. This allows for imperfect field cutting technique during installation without any impact on the installed segmented insulative device.
[0037] It should be understood that the sewing thread used should be formed from moisture and heat resistant material suitable for continuous exposure to temperatures up to and exceeding 500 degrees Fahrenheit. Such suitable materials may include, but are not limited to, high temperature filaments. Possible filament materials include, but are not limited to, aromatic polyamides and fiberglass that may be treated with a polytetrafluoroethylene coating or any other suitable sewing thread that will withstand the temperatures of the given implementation.
[0038] Although FIG. 2B shows only one layer of fiberglass 201 sandwiched between two outer layers 200 , it should be understood that any suitable composite of additional layers may be possible and preferable for different working environments—e.g., extreme humidity conditions. As well, multiple sections of segmented insulation can be used such that they are installed upon one another to create an increased insulative effect. In such instance, the multiple sections of segmented insulation can be overlapped in such a manner that staggers the thinner areas 20 a compressed by the sewing thread 20 b.
[0039] As mentioned above, the sheet of segmented insulation 20 can be formed in any standard size suitable for the given application. Likewise, the sewing threads 20 b may be spaced such that the non-compressed areas in FIG. 2B are generally square or generally rectangular and formed in any suitable size—e.g., 4″×4″, 4″×6″, 8″×8″, . . . etc. However, for most versatility it is preferable that the non-compressed areas are a square dimension of between 4″ and 9″. The segmented pattern effectively means that the segmented insulation 20 can be cut along the small separation 20 a between sewing threads 20 b so that there is minimal exposure of the inner insulation 201 and still provide a snug fit upon installation. The small section 20 a between the sewing threads 20 b is variable upon initial manufacture. However, a range of between 0.5″ to 1″ is preferable because larger values will leave more insulation 201 exposed and would waste materials, whereas smaller values would make fabrication more difficult.
[0040] The inventive aspects of the segmented insulative device formed by the kit elements 10 , 11 , 11 a , 12 , and 13 described with regard to FIGS. 1 , 2 A, and 2 B include the ease by which the segmented insulative device is installed, uninstalled, and reinstalled. This contributes to the invention's significant reusability and related cost-effectiveness. Installation using the kit elements 10 , 11 , 11 a , 12 , and 13 will now be described with regard to FIGS. 3A through 3E in terms of preliminary sizing and FIGS. 4A through 4E in terms of actual installation technique. It should be understood that these installation figures represent but one installation example and relate to a custom installation for an in-line valve 400 , 401 of a generally “T” shaped configuration. Many other configurations and custom installations are possible and will become readily apparent to one of skill in the art upon consideration of the installation details herein below.
[0041] Preliminary to any installation, an installer 100 will measure the portions of the pipe and/or pipe component (e.g., valve 400 , 401 ) desired to be covered by the segmented insulative device. Once measured, the installer 100 will translate such measurements to the portion(s) of the whole sheet of segmented insulation. With regard to FIG. 3A , the installer 100 then uses the scissors 12 and proceeds with cutting the required portion(s) of the whole sheet 30 of segmented insulation. Once the required portion(s) 31 are cut, the installer 100 will then obtain a suitable length of hook-and-loop tape 11 a as shown in FIG. 3B from the roll 11 provided in the kit.
[0042] The cut length of hook-and-loop tape 11 a is then fastened to the required portion(s) 31 of segmented insulation by the installer as shown in FIG. 3C . Fastening of the hook-and-loop tape 11 a can be accomplished staples via stapler 13 . Such staples are preferably capable of use in high humidity/steam environment. To reduce tangling and also to provide a firmer hold for the installer 100 , the loose end of the hook-and-loop tape may be doubled back and stapled to itself as shown in FIG. 3D as element 11 b . The resulting assortment of assembled and custom-sized sections 31 , 32 , 33 of the segmented insulative device are shown in FIG. 3E prior to installation.
[0043] With regard to FIG. 4A , the smallest section 31 of FIG. 3E is shown wrapped and strapped to the uppermost area 400 of the valve. The hook-and-loop tape 11 a may be strapped either tightly or loosely around the section of segmented insulative device depending on whether the installer intends for the valve to be usable without removal of the segmented insulative device. In FIG. 4B , the installer is shown to wrap and strap the next largest section 32 of FIG. 3E to the slightly wider base area of the valve. It should be understood from the figures that the hook-and-loop tape 11 a is typically not in contact with the areas of highest temperature which would be adjacent or contacting the valve or pipe. As such, the hook-and-loop tape 11 a should be capable of continuous use at temperatures less than 500 degrees Fahrenheit and more akin to 325 degrees Fahrenheit surface temperature.
[0044] In FIG. 4C , the installer 100 is placing the largest section 33 of FIG. 3E into place around the in-line section 401 of the valve. In such situation, it should be noted that a better fit has been enabled by the installer 100 snipping several inches into edges of the central seams of the largest section as shown as element 33 a . This allows the lateral areas 33 a of the largest section 33 to be held securely by the hook-and-loop tape 11 a against the adjacent pipe insulation 402 , 403 as seen in FIG. 4D . Likewise, this also allows the valve base area of the largest section 33 to overlap (at 33 a ) the previously installed next smaller section 32 and to also be held securely thereupon by the hook-and-loop tape 11 a as seen in FIG. 4E .
[0045] Accordingly, this completed installation (illustrated by the example seen in FIG. 4E ) of the segmented insulative device by an installer using the kit in accordance with present invention results in a cost-effective, removable, and customizable manner of insulating thermal pipes that is applicable to many different configurations and industrial, institutional, and/or commercial applications. Moreover, the installer by way of the present inventive kit has the ability to measure, cut, and install the segmented insulative device on-site without any need to return to a workshop for fabrication such as sewing or molding. In addition to the kit components described above, the kit may further include an installation manual and/or a material quantity estimating software program or manual worksheet.
[0046] The above-described embodiments of the present invention are intended to be examples only. Alterations, modifications and variations may be effected to the particular embodiments by those of skill in the art without departing from the scope of the invention, which is defined solely by the claims appended hereto.
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A segmented insulative device and related kit for insulating components of a thermal distribution system. The kit includes a sheet of segmented insulation formed by a composite layer of segmented, flexible, pre-sewn insulation that is easily cut to size in the field using scissors, utility knives or other simple, hand-held cutting devices. The kit also includes two-sided hook-and-loop straps as fasteners, also easily cut to length, using hand-held devices. The segmented insulation and the hook-and-loop straps are attached to one another in the field using a stapler or other hand-held attachment device. This provides an installation kit that an installer can use to provide a versatile insulation in the form of the assembled segmented insulative device. The segmented insulative device lends itself to quick customization on-site rather than requiring costly off-site manufacture or pre-assembly and subsequent quick installation on the pipe component requiring thermal installation.
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BACKGROUND OF THE INVENTION
This invention relates to a bus capable of transferring variable length packets (e.g. for POS) at a 10 Gbps rate between two separate cards across a midplane or backplane.
The midplane or backplane (midplane/backplane) has a limited number of physical pins available and signals must pass through two connectors, which potentially could introduce signal integrity issues for high-speed signals.
There is a width vs. speed tradeoff, wherein a slower bus rate is easier and more reliable to implement however it must also be wider, which can be inefficient for short packets.
SQULB (prior art) is a sequenced utopia-3 like bus designed for asynchronous transfer mode (ATM) applications, i.e. fixed sized (56-byte) cells, and as such is not capable of handling variable length packets.
In order to modify SQULB to handle variable length packets, the bus must be made four times wider (four-bytes to sixteen-bytes). This solution is not feasible for the following reasons:
1. The limited number of pins available across the midplane/backplane. There is currently no offering of serializer/deserializer (SERDES) devices capable of handling this bus width. Separate SERDES devices would make it difficult to receive the packet data in the proper order and with minimal signal skew. 2. A sixteen-byte wide bus implies that a single packet could contain up to fifteen empty bytes transferred during the end of packet. This transmission model would be very inefficient and would require a large increase in the operating frequency of the physical bus to maintain a 10 Gbps rate.
THE PRESENT INVENTION
The present invention is directed to a method and apparatus for partitioning packets into segments of a predetermined size (e.g. 64 bytes), serializing the segments, and transmitting the segments over a plurality of channels (for example, four) that have a staggered phase relationship to one another, and wherein the phase difference between adjacent channels (actually, adjacent segments in the sequence of segments that form the packet) is more than the maximum latency that can occur in any one channel, thereby maintaining the ordering of the serialized packet segments, Preferably, there are 64-byte segments divided into four channels and staggering is 2 times maximum latency. While the invention is particularly applicable to variable length packets, the invention can also be used for fixed-length cells as well as variable length packets.
DESCRIPTION OF THE DRAWINGS
The above and other objects, advantages and features of the invention will become more apparent when considered with the following specification and accompanying drawings wherein:
FIG. 1 is a block diagram illustrating the packets divided into 64-byte segments for transmitting over four channels are staggered in their phase relationship to one another,
FIG. 2 is a timing chart showing a single channel bus timing of a given example, and
FIG. 3 illustrates the staggering performed by the transmitting device.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 , packets from transmitter T are divided into 64-byte segments for transmission over four channels CHA, CHB, CHC and CHD that are staggered in their phase relationship to one another. A first array or set of SERDES (serializer/deserializer) devices TSA, TSB, TSC and TSD at the transmitter T in each channel is used to serialize the data and control for transmission across the midplane/backplane P and a second array or set of SERDES devices RSA, RSB, RSC and RSD are used at the receiver R in each channel to deserialize the data. These SERDES devices allow data and control to be passed across the midplane/backplane in a compressed manner and thus reduce the large variable amount of latency for a complete packet transfer. Furthermore, by staggering the phase relationship of the channels, the maximum latency that can occur in any one channel is accommodated and therefore the ordering of packet segments is maintained. For example, in the embodiment implemented in FIG. 1 , the channels are staggered by 40 ns and the maximum latency per channel is 20 ns.
The invention has two basic aspects: the topology of FIG. 1 and a bus protocol that runs on that topology to provide the required bandwidth of 10 Gbps for variable length packets.
With reference to FIG. 2 , the bus protocol will now be briefly described:
Egress Data Path Signal Definitions
The following describes a single channel and what is described is applicable for all four channels and can easily be extended to the complete bus.
Each channel includes a plurality of core data path signals, a 32-bit wide data bus with eleven-bits of out-of-band control, and a number of non-core data path signals, which may be used to transfer additional information.
Packets are broken apart into segments, 64-bytes of data, and transmitted 32-bits per cycle over 16 clock cycles. Packets that are greater than 64 bytes are required to be transmitted over more than one channel.
When data is available for transmission, a Start of Segment (SOS) is raised for one clock cycle concurrent with the first word of the transfer.
When a new packet is being transmitted, a Start of Packet (SOP) signal is raised for one clock cycle concurrent with the first word of the packet. Similarly, when the last word of a packet is being transmitted, an End of a Packet (EOP) signal is raised for one clock cycle concurrently with the last word. The Empty (MPTY) signals indicate how many bytes of the current word are valid. Since the bus is a word-wide (i.e. 32-bits will be transferred each clock cycle) up to three bytes of PAD may be present on a transfer. The MPTY signals are only valid when an EOP occurs. If the packet happens contain an error, then the Error (ERR) signal becomes active while EOP is active.
During the complete data transfer, the Valid (VAL) signal is active. The parity across this interface should always be valid for both the data path (DPRTY) signal and the control path (CPRTY) signal.
If there is no data to be transferred, idle cycles will occur on the bus. For an idle cycle, the data bus and all the control signals (except parity) will be driven low. The parity will remain valid at all times.
Summarizing:
1. Data packets are divided into 64-byte segments,
2. This interface has parity protection for all data and control signals (DPRTY and CPRTY),
3. Each segment is serialized to four bytes wide [Data(31:0)] and each segment is tagged with a set of out-of-band control signals, as shown in FIG. 2 . The associated control signals consist of start and end of packet indications (SOP and EOP), error indication (ERR), and the number of empty bytes transmitted during the end of packet condition. This information is then used by the receiver to properly assemble the packet.
FIG. 3 illustrates the staggering performed by the transmitting device T.
The advantages of the invention, in general, and over the closest prior art solution include:
1. variable length packets can be transmitted very efficiently at a low bus frequency while maintaining a bandwidth of 10 Gbps. Furthermore, in the present implementation, the segmentation of packets into 64-byte segments means that ATM cells can also be transmitted very efficiently over the bus. 2. The described bus topology is easily amenable to quad OC48. 3. Since the bus is divided into segments transmitted four-bytes at a time, there is only a need for a maximum of three empty bytes per packet. This scheme makes the bus more efficient and allows it to operate at a slower frequency while still achieving 10 Gbps rates.
The invention is directed to the method and apparatus of partitioning packets into segments of predetermined size (for example, 64-bytes), serializing the segments, and transmitting them over a plurality of channels (for example, four) that have a staggered phase relationship to one another, and wherein the phase difference between adjacent channels (actually, adjacent segments in a sequence of segments that form the packet) and more than the maximum latency that can occur in any one channel, thereby maintaining the order of the serialized packet segments. The invention is not limited to variable-length packets as the invention can be used for both fixed-length cells and variable-length packets.
This invention addresses an obstacle and solves the problem that will be encountered by any efforts to pass variable-length packet data between separate cards.
While the invention has been described in relation to preferred embodiments of the invention, it will be appreciated that other embodiments, adaptations and modifications of the invention will be apparent to those skilled in the art.
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A method and apparatus of communicating data packets across the midplane of an electronic system in which the packets are partitioned into segments of a predetermined size and then serialized to a predetermined width. The serialized packets are transmitted, in phase staggered segments, across the midplane on a respective channel, received into receiving end and the serialized segments that have traversed the midplane, are deserialized and reassembled into the original data packet.
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BACKGROUND
1. Field
The invention disclosed herein relates to a device for use in ligament reconstruction surgery, and more specifically, a device and method for performing measurements.
2. Description of the Related Art
Common techniques for reconstruction of ligaments require the drilling of a tunnel through bone. For example, reconstruction of a torn anterior cruciate ligament (ACL) requires drilling through the femur of a patient. Once a femoral tunnel has been drilled. a surgeon needs to perform measurements to determine the depth of the tunnel to aide in selection of the appropriate repair technique.
While a variety of devices are available to measure the length of the femoral tunnel, many of these devices are complicated to use and may lead to confusion during surgical procedures. For example, some devices make use of a guide wire that is passed into the femoral tunnel and received by a measuring device as it exits the femoral tunnel. Unfortunately, the various receiving devices presently available often do not securely retain the guide wire. Accordingly, this may lead to erroneous measurements, and worse yet to glove damage or laceration of the surgeon.
Thus, what are needed are methods and apparatus to provide for accurate and safe measurement of the femoral tunnel. Preferably, the methods and apparatus are simple and easy to understand during a surgical procedure as well as cost-effective.
SUMMARY
In one embodiment, a device for measuring a length of a bone tunnel is provided. The device includes: a gauge comprising an annular shaft coupled to a handle, the handle including a constrained channel configured for receiving a passing pin from the annular shaft and displaying the passing pin in relation to a scale.
In another embodiment, a method for measuring length of the bone tunnel is provided. The method includes: placing a gauge over a passing pin, the tunnel gauge including an annular shaft coupled to a handle, the handle also having a constrained channel configured for receiving the passing pin from the annular shaft and displaying the passing pin in relation to a scale; and, comparing a reference mark on the passing pin to the gauge to determine the length.
In a further embodiment, a device for measuring a length of a bone tunnel is provided. The device includes: a passing pin having a region configured to be maintained within a constrained channel of a measurement device; and, a gauge including an annular shaft coupled to a handle, the handle also having a constrained channel configured for receiving the passing pin from the annular shaft and displaying the passing pin in relation to a scale.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the invention are apparent from the following description taken in conjunction with the accompanying drawings in which:
FIG. 1 is an isometric view of a tunnel gauge according to an embodiment of the invention;
FIG. 2 is an isometric view of a handle of the tunnel gauge of FIG. 1 , from a different angle;
FIGS. 3A, 3B and 3C , collectively referred to herein as FIG. 3 , provide another isometric view of the handle of the tunnel gauge of FIG. 1 . FIG. 3A provides the isometric view of a complete embodiment of the handle, while FIG. 3B provides a cutaway of the isometric view of FIG. 3A . FIG. 3C provides a close-up view of the cutaway shown in FIG. 3B , additionally with a cross-section of the passing pin;
FIG. 4 provides an isometric view of a passing pin suited for use with the tunnel gauge of FIG. 1 ;
FIG. 5 is a blown up isometric view of a portion of the handle of the tunnel gauge with the passing pin loaded therein; and,
FIG. 6 is an isometric cutaway view of the tunnel gauge in use with the passing pin.
DETAILED DESCRIPTION
Disclosed herein are methods and apparatus for performing measurements of a bone tunnel. As discussed herein, the bone tunnel is a femoral tunnel (i.e., a hole that has been drilled through a portion of a femur of a patient). However, this is merely exemplary and it is not limiting of the teachings herein.
Generally, the apparatus disclosed herein is a two-part apparatus. In order to measure the femoral tunnel, a first part, a passing pin, is inserted into the femoral tunnel. Insertion of the passing pin is stopped when a reference mark on the passing pin aligns with an outer surface of the femoral condyle. A second part of the device, a tunnel gauge, is then disposed over a portion of the passing pin that has emerged from an opposing side of the femur. By placing the tunnel gauge against the opposing side of the femoral condyle and by referencing a scale on the tunnel gauge, a surgeon is able to determine a depth of the femoral tunnel.
Referring now to FIG. 1 , there is shown an exemplary tunnel gauge 10 according to the teachings herein. In this example, the tunnel gauge 10 includes a shaft 1 and a handle 2 . Generally, the shaft 1 is mounted to the handle 2 at a base 3 .
Note that merely for convenience of referencing and an explanation of the teachings herein, the terms “distal” and “proximal” as well as other such relational or descriptive terms are used. This terminology should not be construed to imply any orientation for implementation of the methods and apparatus disclosed herein. Generally, the term “distal” and “proximal” are with respect to an individual using the device (e.g., a physician). For example, when inserting a passing pin, an end of the passing pin that is being inserted may be referred to as a “distal” end of the passing pin. Similarly, when placing the tunnel gauge 10 against the femur, it may be considered that the shaft 1 is a distal portion of the tunnel gauge 10 , while the handle 2 is a proximal portion of the tunnel gauge 10 .
In the exemplary embodiment, the tunnel gauge 10 is disposed about a longitudinal axis, A. Again, the longitudinal axis, A, and any other techniques for referencing are merely for purposes of explanation and are not limiting of the teachings herein.
In the embodiment shown, the shaft 1 is an annular cylinder. The shaft 1 includes a receiver 4 , a tapered section 5 , and an elongated section 6 . The shaft 1 may be mounted to the handle 2 at the body 3 by any one (or more) of a variety of suitable techniques. For example, the shaft 1 may be threaded into a receiving section within the body 3 . The shaft 1 may be glued, hot melted, fastened or otherwise mated or joined with the body 3 .
Generally, the shaft 1 has an inner diameter designed to accommodate a passing pin (as shown in FIG. 4 , and as discussed further herein). For example, the shaft 1 may have an inner diameter that is slightly larger than 2.4 mm or 2.7 mm, such that it may securely accommodate passage of the 2.4 mm or 2.7 mm passing pin, respectively.
In the embodiment shown, the shaft 1 is an annular cylinder. The shaft 1 includes a receiver 4 , a tapered section 5 , and an elongated section 6 . The shaft 1 may be mounted to the handle 2 at the base 3 by any one (or more) of a variety of suitable techniques. For example, the shaft 1 may be threaded into a receiving section within the base 3 . The shaft 1 may be glued, hot melted, fastened or otherwise mated or joined with the base 3 .
The handle 2 includes a central channel 9 . The channel 9 is configured to receive the passing pin as it emerges from the elongated section 6 of the shaft 1 . In order to view the central channel 9 (and therefore the passing pin), a window 7 is provided within the body of the handle 2 . In this example, the window 7 presents as a cutaway along a length of the handle 2 .
Disposed within the window 7 is at least one gauge 8 . The gauge 8 is disposed along a length of the channel 9 within the window 7 . Accordingly, as the passing pin is received within the channel 9 , and extends into the handle 2 , a depth of the femoral tunnel may be ascertained. That is, the gauge 8 includes at least one scale for measuring depth of the femoral tunnel (i.e., a length of the femoral tunnel). This will be explained in greater detail further herein.
In this example, the gauge 8 is provided in centimeters, with subdivisions of millimeters. However, any linear scale deemed appropriate may be used in the gauge 8 (i.e., system international (SI), English, metric or other standards may be used).
Referring now to FIG. 2 some of the foregoing aspects are shown from another angle. In addition, it may be seen that the handle 2 may include an exit-way 12 from the channel 9 . Generally, the exit-way 12 may be provided to facilitate cleaning of the handle 2 after use. For example, it may be desirable to flush a sterilizing cleaning fluid through at least one of the receiver 4 and the exit-way 12 to ensure removal of all debris as well as sterilization of the tunnel gauge 10 .
Referring to FIGS. 3A and 3B , additional isometric views of the handle 2 are shown. FIG. 3A is provided merely for understanding the depiction in FIG. 3B , which depicts a cutaway portion of the handle 2 . As shown in FIG. 3B , the channel 9 may be configured with a “C” shaped cross-section. That is, the channel 9 may be configured to securely retain the passing pin while providing for display thereof. An example of this is better shown in FIG. 3C .
Referring now to FIG. 3C there is shown an exploded view of the cutaway portion of the channel 9 of FIG. 3B . Further, in this illustration, a portion of a passing pin 21 is shown. As may be seen in FIG. 3C , the channel 9 may include at least one section of retaining material 31 . More specifically, retaining material 31 may be included to retain the passing pin 21 within the channel 9 . In this example, retaining material 31 is disposed symmetrically about the channel 9 . However, in some embodiments, retaining material 31 is provided on merely one side of the channel 9 . In use, the retaining material 31 provides for observation of the passing pin 21 while narrowing an open portion of the channel 9 substantially enough that the passing pin 21 could not be diverted out of the channel 9 (i.e., the open portion of the channel 9 has a width that is less than a diameter or width of the passing pin 21 ).
In this embodiment, the retaining material 31 provides for a “constrained channel” 9 . It may be considered that the term “constrained channel” generally refers to any type of channel that may be characterized as having a particular geometry (e.g., a cross-section) that provides for retention of the passing pin 21 or any other similar component (e.g., a guide wire, a drill, a drill shank, and the like).
More specifically, in this example, the passing pin 21 exhibits a cross-section of a dimension, denoted as “CS.” The constrained channel 9 has a relatively narrow opening. That is, a dimension for the opening provided for display of the passing pin 21 is less than that of the cross-section of the passing pin 21 . Accordingly, it should be understood that the constrained channel 9 may have a narrow opening the generally limits the capability of the passing pin to migrate from the channel 9 .
Also shown in FIG. 3C , is a measuring mark 33 . In this example, the measuring mark 33 is characterized as a single line disposed about a circumference (or perimeter, as the case may be) of the passing pin 21 . In some embodiments, the measuring mark 33 is disposed about the passing pin 21 by use of laser etching. However, any technique for providing a measuring mark 33 that is deemed appropriate may be used.
In some embodiments (not shown), the measuring mark 33 includes a plurality of marks. For example, the measuring mark 33 may include another scale. The another scale may be compared to markings in the gauge 8 .
Referring now to FIG. 4 , an embodiment of the passing pin 21 is shown. In this example the passing pin 21 is a unitary device. The passing pin may be flexible, rigid or exhibit any appropriate combination of properties. The passing pin 21 may include a reference mark 23 which serves as a stop point during insertion of the passing pin 21 into the femoral tunnel. In addition, the passing pin 21 may include at least one marking indicator 24 to enhance visibility of the reference mark 23 . In this example, the marking indicator 24 is an elongated stripe that extends along a portion of the length of the passing pin 21 .
In some embodiments, the passing pin 21 includes a fluted end. The fluted end may be provided so that the passing pin 21 may also provide for drilling of the femoral tunnel. In this example, the passing pin 21 includes a pointed end which facilitates its insertion into the femoral tunnel, once the femoral tunnel has been drilled and the drill removed. The pointed end of the passing pin 21 allows it to penetrate any drilling debris remaining in the tunnel. In use, the passing pin 21 is inserted into the femoral tunnel until the reference mark 23 is aligned with a distal cortex of the femur.
Referring back to FIG. 1 , once the passing pin 21 has been inserted, the tunnel gauge 10 is disposed over the portion of the passing pin 21 which extends from the femur, and in some instances from a skin of the patient. Once the shaft 1 of the tunnel gauge 10 has been disposed over the passing pin 21 , the shaft 1 is then pushed through the surrounding tissue. Accordingly, the tapered section 5 of the shaft 1 facilitates insertion of the shaft 1 by displacing the tissue. Once the receiver 4 has been abutted against a proximal cortex of the femur, it is possible to accurately measure a depth of the femoral tunnel.
Referring now to FIG. 5 , an embodiment of the tunnel gauge 10 with the passing pin 21 loaded therein is shown. It may be seen that, in this example, the femoral tunnel is about 41 mm deep.
According to FIG. 6 a cutaway view of the tunnel gauge 10 and passing pin 21 is shown in use. All surrounding tissue has been removed from this illustration to better depict cooperation of the passing pin 21 with the tunnel gauge 10 .
Having thus introduced embodiments of the tunnel gauge 10 , some additional aspects are now provided.
In some embodiments, the handle 2 and the shaft 1 are a unitary structure. For example, the handle 2 and the shaft 1 may be fabricated from a biocompatible plastic. This may be performed by injection molding or other suitable techniques. In some additional embodiments, one of the handle 2 and the shaft 1 is fabricated from a plastic or polymeric material while the other component is fabricated from metal or a metallic material. One exemplary polymeric material is polyphenylsulfone (PPSU). PPSU may be characterized as a material having a high heat resistance and excellent hydrolytic stability. Other materials that may withstand repeated cycling through sterilization environment (i.e., cleaning with steam, alcohol or other suitable materials) and that provide desired structural integrity may be used.
The passing pin 21 may be provided in a variety of configurations. For example, the passing pin 21 may be generally cylindrical (such as in the form of a wire), may be annular (such as in the form of a straw), or of another cross-sectional geometry (such as a square, a rectangle, a triangle, or an n-gon) as deemed appropriate and suited for use with the constrained channel 9 . The passing pin 21 may include at least one loop or eyelet, such as for carrying suture. Although discussed herein as the passing pin 21 , any device suited for insertion through the femoral tunnel (or any other bone tunnel) may be used with the tunnel gauge 10 . For example, the tunnel gauge 10 may be configured to receive a drill.
In some embodiments, the handle 2 may be separated from the shaft 1 to facilitate cleaning and sterilization of the tunnel gauge 10 .
Although presented herein with regards to reconstruction of ligaments and drilling of a femoral tunnel, the tunnel gauge 10 may be used to ascertain a depth or length of any type of bone tunnel, as deemed appropriate.
While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
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In one embodiment, a device for measuring a length of a bone tunnel is provided. The device includes: a gauge comprising an annular shaft coupled to a handle, the handle including a constrained channel configured for receiving a passing pin from the annular shaft and displaying the passing pin in relation to a scale. In another embodiment, a method for measuring length of the bone tunnel is provided. A method and another device are provided.
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The Government has rights in this invention pursuant to Grant No. 5 T01 EY00090 from the National Institutes of Health.
BACKGROUND OF THE INVENTION
This invention relates to test patterns for use in testing the quality of a lens and more in particular to a vernier resolution chart and a triangular-wave pattern for testing of a camera lens.
The method preferred in the prior art for testing camera lenses is the direct measurement of the modulation transfer function (mtf) using specialized electronic instruments as in "Electro-Optical Methods of Image Evaluation", Baker, L. R., and T. Moss, Electro-Optical Systems Design Conference, New York City, 1969. Photographic methods for making similar measurements are less accurate, and usually require the use of a microdensitometer. An attempt to circumvent this limitation is that described in "The Sharpness Indicator", I. Putora, J. of the SMPTE, 78: pp. 956-960, November 1969 who photographs circular test patterns of varying fineness with high contrast film; the lens resolution is determined directly by inspection of the negative. Described herein are different improved test patterns which provide direct indication of lens performance when photographed with high contrast film.
SUMMARY OF THE INVENTION
New types of charts are described for testing the quality of a lens. One form of chart is a vernier chart which tests the quality of lens by measuring its edge response function which is reflected in the vernier chart by an apparent shift in the imaged position of a line. A second test pattern is a sawtooth of varying spacial frequency. The degradation in the frequency response of the lens is exhibited by a an apparent decrease in amplitude of the higher spacial frequencies. A third form of chart is one where the intensity in one direction along the length of the chart varies periodically and sinusoidally at increasing spacial frequency along the chart. In the other direction, the reflectance varies linearaly between the value at the top of the chart and the value at the corresponding position at the bottom of the chart.
IN THE FIGURES
Other advantages, features, and objects of the invention will appear from the following description taken together with the drawings in which:
FIG. 1 is the vernier chart embodiment of this invention.
FIG. 2 is the imperfectly focussed image of the chart of FIG. 1.
FIG. 3 shows the reflectance distribution across a section on both sides of a black line of FIG. 2.
FIG. 4 shows a sawtooth chart embodiment of this invention.
FIG. 5 shows the imperfectly focussed image of the chart of FIG. 4.
FIG. 6 shows a section of the chart FIG. 7 illustrating the reflectance change along the chart.
FIG. 7 is a chart illustrating the reflectance distribution shown in FIG. 6.
FIG. 8 shows a lens testing system.
FIG. 9 shows a test chart using the charts of FIGS. 1, 4, or 7.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the vernier resolution chart of this invention. The vernier chart of FIG. 1 utilizes pairs of black lines 1, 2 displaced by successive increments 3, on a 20% grey background 4. White lines or borders 5, 6 are placed on opposite sides of the black lines 1, 2, respectively, as indicated. The operation of the chart depends on the small differential motions of the images of the black lines 1 and 2 due to the spreading of the white border into the black, and the black line into the grey background, when an unsharp image is produced by the lens being tested. The degree of unsharpness of the image is indicated by the altered vernier correspondence of the displaced line images.
This behavior of the vernier chart is illustrated in FIG. 2, which represents a photograph of the chart of FIG. 1 with a prescribed amount of defocus in the camera. Note that the vernier correspondence, which occurs at line pairs numbered 1 in FIG. 1, occurs at line pairs numbered 3 in the defocussed image of FIG. 2 because of the shift in relative position of lines 1', 2'. The defocussed image is used as a simulation of the lens defects of astigmatism, or curvature of field. Tests indicate that defocus, lens aberrations, and diffraction blur all affect the vernier sharpness index in FIG. 2. The greater the shift of lines 1',2', the poorer the quality of the lens.
A qualitative explanation for the action of the vernier chart is facilitated by consideration of the diagram of FIG. 3. Here the reflectance cross section of the image of a black line 2' and white area or line 6' as on the chart of FIG. 2 are shown. The curves A, B, and C represent the response for perfect, slightly unsharp, and more unsharp image focussing, respectively. Also shown in the assumed 20% clipping level of high contrast film in the camera which determines where the print image will be white or black. The response of either curve B or C is represented in FIG. 2. From FIG. 3 it is seen that the result of the finite slope of the line spread function of the defocussed images is to move the image of the black lines 1, 2 away from the white areas, 5, 6, respectively, as shown in FIG. 1. This increment of movement is somewhat dependent on the choice of clipping level.
Examination of FIG. 3 discloses that the width of the black line is substantially preserved by having the side of the black line opposite that of the white line be a grey tone of approximately 25% reflectance and where the high contrast film has a transition from white to black at the 20% reflectance level. Preservation of the line width of the black lines makes the result comparison of the shifted lines 1', 2' more easy and accurate than otherwise.
It is preferred that the width of the black line 1 of FIG. 1 is sufficiently wide so that when it is bordered on one side by the white area 5 and the other side by grey area 4 there results a reproduced black line 1' as in FIG. 2 which is readily observable. For the chart of FIG. 1 a typical width of the black lines 1, 2 is 12 mils, the width of the white region 5 and 6 being about 60 mils and the incremental shift in position as for example between the pairs numbered 1 and those numbered 2 of the black lines 1 and 2 of FIG. 1 being about 2 mils per position. The widths of black lines 1 and 2 and white regions 5 and 6 together with the incremental shift in position of black lines 1 and 2 for each position on the chart are not critical dimensions. However these dimensions, especially the incremental displacement of the black lines, will affect the position of alignments as in FIG. 2 and therefore calibration of a chart is necessary for it to provide line resolution of MTF data. This calibration information could be provided on the chart instead of the numeral representations of positions 1-5.
It should be recognized that FIG. 1 may have more line-pairs than the five line-pairs shown.
Extensive tests with a variety of early and contemporary 35-mm camera lenses at different aperture settings have demonstrated that the vernier chart (edge sharpness gauge) is a useful and sensitive test for the assessment of lens quality. The particular advantages of this method are: (a) the test result is largely unaffected by the parameters of the photographic process, (b) the test result is independent of the sharpness of the enlarging lens used to make the print, (c) the test result is directly interpretable in terms of the steepness of the edge response function of the lens, which is of course, the Fourier Transform of the mtf response, (d) since the method does not require a microdensitometer, it can be used by amateur and professional photographers of limited budget or little scientific training. The ability of the unaided eye to perceive very small displacements of alignments is utilized in the chart of FIG. 1; this ability is termed Vernier Acuity.
A further application of the vernier chart is to measure the performance of microscope lenses. The advantage here is that the vernier chart does not require line elements too fine to reproduce by microphotography, as in the case with conventional resolution charts.
A second test method is the use of the triangular wave pattern shown in FIG. 4. For this purpose, a set of triangular patterns 10 of geometrically increasing spacial frequency were generated on an oscilloscope and combined as a photo-montage. In FIG. 5 the result is shown of photographing this montage with an inferior lens, with high contrast film and using an exposure index chosen to render the pattern symmetrical with respect to the white reference line 11 and the black reference line 12. In other words; the clipping level of the high-contrast film corresponds to a reflectance value of 0.5. The amplitude of the envelope 13 of the patterned triangular areas renders an approximate plot of the mtf response of the lens; if the response is highly degraded, this approximation becomes quite exact. Analysis shows that, for only slightly degraded responses, the fall off in the height of the triangular-wave pattern is proportional to the linear extent of the edge response function, evaluated at the 25% and 75% points.
These results suggest the existence of a pattern which, when photographed with very high contrast ratio, would indicate the exact mtf response of the lens. The realization of such a pattern requires continuous tone reflectance variation according to the equation:
R=(1/4) sin ωx+(1/2)y+(1/4)
Where x and y are coordinates in the plane of the paper as shown in FIG. 6, 7. In FIG. 6 the scale of the x-coordinate has been enlarged for clarity. The reflectance is to exhibit a sinusoidal variation with x, together with a linear shading with y. The operation of this chart is explained by analogy with the sphygmomanometer, used to measure blood pressure. The reflectance along the x direction of the chart of FIG. 6 varies sinusoidally with monotonically increasing frequency; at the top of the chart reflectance varies from 1 to 0.5 to 1. At the mid-height of the chart, reflectance has a periodic sinusoidal variation of increasing frequency from 0.75 to 0.25 to 0.75. At the bottom of the chart, reflectance varies sinusoidally from 0.5 to 0 to 0.5. The reflectance varies lineraly in the y direction.
Because of difficulty in drawing a chart having continuous gradations in reflectance, the chart of FIG. 7 is a discrete approximation having regions with fixed reflectance and with the degree of reflectance shown within each region. As the frequency of the sinusoidal variation in intensity increases, the width of the regions of FIG. 7 decrease in the x direction to indicate increased frequency. Thus if the film clips at 0.5 reflectance, and if the chart is imaged perfectly, substantially any cross-section 70 of the high contrast image chart of FIG. 7 will contain both black and white areas. Now however, if the sinusoidal component of reflectance is reduced by imperfect imagery by a factor α<1, then the region of the high-contrast image of the chart defined by the equation y<α/2 will be solid white, and the region 1-α/2 will be black. The extent of the intermediate shaded region will, therefore, be reduced by the same factor α. A composite chart as approximated in FIG. 7, with progressively increasing spacial frequencies will, when so photographed, render an exact plot of the mtf response of the lens. The spacial sinusoidal frequency of the chart, instead of being continuously increasing, can be increased by discrete increments as shown in FIG. 7. FIG. 8 illustrates a lens test assembly where the chart 73 is focussed on film 71 by the lens 72 which is being tested. The chart 73 may be any of those illustrated in FIG. 1, 4 or 7 and the contrast of the film 71 should be compatible with the test chart and the exposure index being used is in conformance with the clipping levels of the film as taught in the foregoing specification.
FIG. 9 shows an arrangement of the vernier charts 8 and triangular charts 9 which have been placed on a wide area chart 73, typically 20×30 inches, where each of the charts 8, 9 is substantially 3 inches long. For this chart, the triangular wave patterns have been specially fabricated so as to have a reflectance value of 40% in those areas which were heretofore described as being white (100% reflectivity), black areas being reproduced as black. The arrangements of the charts as shown in FIG. 9 allows the center and the edges of the lens to be checked simultaneously. It should be recognized that the individual charts 8 or 9 may be used instead of the combination shown in FIG. 9. It should also be recognized that the chart of FIG. 7 could be substituted for the either chart 8 or 9.
It is evident that those skilled in the art, once given the benefit of the foregoing disclosure, may make numerous other uses and modifications of, and departures from the specific embodiments described herein without departing from the inventive concepts. Consequently, the invention is to be construed as embracing each and every novel combination of features present in, or possessed by, the apparatus and techniques herein disclosed and limited solely by the scope and spirit of the appended claims.
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Lens testing charts using a vernier pattern, a sawtooth pattern, and a sinusoidally varying reflectance pattern are described and are used in conjunction with a lens under test to be focussed by said lens onto suitable high contrast film to provide an image from which the quality of the lens may be determined.
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BACKGROUND OF THE INVENTION
1. Field of the invention
This invention relates in general to a mono-layer type or multi-layer type electrophotographic element, and in particular to a novel electrophotographic element having a photosensitive layer containing as an available ingredient a hydrazone compound having the following general formula (I) or an anile compound having the following general formula (II): ##STR3## [where R 1 is a methyl, ethyl, 2-hydroxyethyl or 2-chloroethyl group; R 2 is a methyl, ethyl, benzyl or phenyl group; and R 3 is chlorine, bromine, a C 1 -C 4 alkyl group, a C 1 -C 4 alkoxy group, a dialkylamino group with C 1 -C 4 alkyl or a nitro group.] ##STR4## [where R 1 is the same as the said general formula (I); and R 4 is a substituted or non-substituted phenyl, naphthyl, heterocyclic or C 1 -C 10 alkyl group.]
As the substitution groups for the substituted phenyl referred to in the general formula (II) there can be enumerated C 1 -C 4 alkyl group, C 1 -C 4 alkoxy group, dialkylamino group with C 1 -C 4 alkyl, hydroxy group, etc. And, the heterocyclic group referred to in the general formula (II) includes pyridyl, benzothiazolyl and the like.
2. Description of the Prior Art
Inorganic substances such as selenium, cadmium sulfide, zinc oxide, etc. have hitherto been utilized as photoconductive materials for use in elements in electrophotographic processes. In this context, it is to be noted that the "electrophotographic process" referred to herein generally denotes one of the image forming methods which comprise the steps of electrifying a photoconductive element in the dark first of all for instance with corona discharge or the like, then exposing the element to light in an imagewise manner to selectively dissipate the charge from only the light struck portions of the element thereby forming a latent image and rendering the latent image visible by means of a developing process utilizing an electroscopic fine powder comprising a coloring agent called a toner such as dye, pigment or the like and a binder resin such as resin, high molecular substance or the like thereby forming a visible image. The element adapted for the above-mentioned electrophotographic process is required to possess the following fundamental characteristics: (1) capability of being charged with a suitable potential in the dark, (2) low discharge rate in the dark, (3) rapid dischargeability upon light radiation and so forth. The hitherto utilized inorganic substances as enumerated above surely possess a number of merits, but at the same time possess various demerits. For instance, the now universally utilized selenium can satisfy the aforesaid requirements (1) to (3) to a sufficient degree, but is defective in that it is manufactured with difficulty and consequently the manufacturing cost is high. In addition, the selenium is defective in that it is difficult to process the selenium, which has no flexibility, into a belt, close attention must be paid in handling the selenium which is very sensitive to mechanical impacts and the like. On the other hand, the cadmium sulfide and zinc oxide are utilized in the element in the manner of their being dispersed in a binder resin. However, such element lacks the mechanical characteristics such as smoothness, hardness, tensile strength, frictional resistance, and therefore it can not stand repeated use.
In recent years, electrophotographic elements employing various kinds of organic substances have been proposed in order to remove the drawbacks inherent in the inorganic substances as enumerated above. Some of said elements are put to practical use, for instance, such as the element including poly-N-vinylcarbazole and 2,4,7-trinitrofluorene (U.S. Pat. No. 3,484,237), the element including poly-N-vinylcarbazole sensitized with a pyrylium salt type pigment (Japanese Patent Publication No. 25658/1973), the element including an organic pigment as the principal ingredient (Japanese Laid-open Patent Application No. 37543/1972), the element including a cocrystalline complex consisting of dye and resin as the principal ingredient (Japanese Laid-open Patent Application No. 10735/1972), etc. However, the fact is that these elements surely are considered to possess superior characteristics as well as high practical values, but, when taking into consideration various requirements for elements, can not meet these requirements yet to a satisfactory degree.
On the other hand, it is perceived that these excellent elements, though there is a difference therebetween depending on their objects or manufacturing processes, can generally exhibit superior characteristics as a result of incorporating high-efficient photoconductive materials therein.
SUMMARY OF THE INVENTION
We have made a series of studies on the photoconductive material of this kind to discover the fact that said hydrazone compound having the general formula (I) or said anile compound having the general formula (II) acts effectively as the photoconductive material for electrophotographic elements. In other words, we have discovered that the hydrazone compound (I) or the anile compound having the general formula (II), as mentioned subsequently, can provide, when combined with various kinds of materials, elements which can exhibit unexpectedly superior effects and are rich in surprisingly versatile usability.
The hydrazone compound having the general formula (I) or the anile compound having the general formula (II) suitably used for this invention is prepared in any usual manner, in other words, in the manner of causing a condensation reaction between equimolecular weights of 3-formyl carbazoles and phenylhydrazines [in the case of the general formula (I)] or amines [in the case of the general formula (II)] in alcohol, if needed, by adding a small quantity of acid (glacial acetic acid or mineral aicd). There are instances where said hydrazines or amines preferably should be used in slightly excess quantities at the time of condensation reaction for the purpose of facilitating the purification of raw reaction products.
As the compounds corresponding to the general formula (I) there can be enumerated the following ones. ##STR5##
As the compounds corresponding to the general formula (II), furthermore, there can be enumerated the following ones. ##STR6##
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are each an enlarged cross-sectional view of a mono-layer type electrophotographic element according to this invention.
FIG. 3 is an enlarged cross-sectional view of a multi-layer type electrophotographic element according to this invention.
The reference numerals in the drawings identify the following members:
1 . . . conductive substrate
2,2',2" . . . photosensitive layer
3 . . . charge generation material
4 . . . charge transport medium
5 . . . charge generation layer
6 . . . charge transport layer.
The electrophotographic elements according to this invention, which include the above defined hydrazone compounds or anile compounds, can take the forms illustrated in FIGS. 1 to 3 depending upon how these hydrazone compounds or anile compounds are applied. The element illustrated in FIG. 1 comprises a conductive substrate 1 and a photosensitive layer 2 adjacent the substrate, the photosensitive layer consisting essentially of a hydrazone compound (1) or anile compound (II), a sensitizing dye and a binder resin. The element illustrated in FIG. 2 comprises a conductive substrate 1 and a photosensitive layer 2' adjacent the substrate, the photosensitive layer 2' being formed by dispersing a charge generation material 3 in a charge transport medium comprising a hydrazone compound (I) or an anile compound (II) (these are sometimes called a charge transport material respectively) and a binder resin. The element illustrated in FIG. 3 comprises a conductive substrate 1 and a photosensitive layer 2" adjacent the substrate, the photosensitive layer 2" being comprised of a charge generation layer 5 which is essentially a charge generation material 3 and a charge transport layer 6 including a hydrazone compound (I) or an anile compound (II).
In the element of FIG. 1, the hydrazone compound (I) or the anile compound (II) functions as a photoconductive material and therefore the generation and transportation of charges required for light decay is effected through the hydrazone compound or anile compound. However, as the hydrazone compound (I) or the anile compound (II) is scarcely absorptive to visible light region, in case where it is utilized for the purpose of forming an image by means of visible light, it must be sensitized with a sensitizing dye being adsorptive to visible light region.
In the case of the element of FIG. 2, the hydrazone compound (I) or the anile compound (II) forms a charge transport media in conjunction with a binder (and a plasticizer as occasion demands), while the charge generation material such as an inorganic or organic pigment generates charges. In this case, the main ability of the charge transport media is to accept charges that the charge generation material generates and to transport the charges. It is fundamentally required in this instance that the absorption wave length regions of both the charge generation material and the hydrazone compound (I) or anile compound (II) should not overlap each other mainly in the visible light region. This is because there is the necessity for permitting light to transmit up to the surface of the charge generation material so that the latter may generate charges efficiently. The hydrazone compound (I) or anile compound (II) according to this invention is characterized in that it is scarcely absorptive to the visible light region and generally acts as the charge transport material effectively especially when combined with the charge generation material capable of generating charges upon absorption of light in the visible region.
In the case of the element illustrated in FIG. 3, the light transmitted through the charge transport layer 6 reaches the charge generation layer 5 to thereby generate charges at the light struck portions thereof, while the thus generated charges are injected in the charge transport layer 6 and transported therethrough. The mechanism employed herein that the generation of charges required for light decay is allotted to the charge generation material, while the transportation of the charges is allotted to the charge transport medium (the hydrazone compound (I) or the anile compound (II) of this invention mainly acts for that purpose) is the same as that employed in the element illustrated in FIG. 2. The hydrazone compound (I) or the anile compound (II) acts as the charge transport material herein, too.
The element illustrated in FIG. 1 may be prepared by coating a solution onto a conductive substrate and drying, said solution being obtained by dissolving a hydrazone compound (I) or an anile compound (II) in a binder solution and further adding a sensitizing dye thereto as occasion demands.
The element illustrated in FIG. 2 may be prepared by coating a dispersion onto a conductive substrate and drying, said dispersion being obtained by dispersing fine particles of a charge generation material in a solution containing dissolved therein a hydrazone compound (I) or an anile compound (II) and a binder. The element illustrated in FIG. 3 may be prepared by vacuum-evaporating a charge generation material onto a conductive substrate or coating onto a conductive substrate a dispersion obtained by dispersing fine particles of the charge generation material, if needed, in a suitable solvent containing dissolved therein a binder, then by coating a solution containing a hydrazone compound (I) or an anile compound (II) and a binder onto the resulting charge generation layer and, if further needed, after surface finishing or film thickness regulation by, for instance, buffing or the like, and drying. The coating method used herein includes usual means, for instance, such as doctor blade, wire bar and the like.
The photosensitive layers of the elements illustrated in FIGS. 1 and 2 are each between about 3 microns and 50 microns thick, preferably between about 5 microns and 20 microns thick. In the case of the element illustrated in FIG. 3, the charge generation layer is about 0.01 to 5 microns thick, preferably about 2 microns or less thick, and the charge transport layer is between about 3 microns and 50 microns thick, preferably between about 5 microns and 20 microns thick. In the case of the element illustrated in FIG. 1 the percentage of the hydrazone compound (I) or anile compound (II) contained in the photosensitive layer is in the range of from about 30 to 70% by weight, preferably about 50% by weight relative to the photosensitive layer. The percentage of the sensitizing dye used for rendering the photosensitive layer sensitive to the visible region is in the range of from about 0.1 to 5% by weight, preferably from about 0.5 to 3% by weight relative to the photosensitive layer. In the element illustrated in FIG. 2, the percentage of the hydrazone compound (I) or anile compound (II) to the photosensitive layer is in the range of from about 10 to 95% by weight, preferably from about 30 to 90% by weight, and the percentage of the charge generation material to the photosensitive layer is in the range of from about 0.1 to 50% by weight, preferably about 20% by weight or less. In the element illustrated in FIG. 3, the percentage of the hydrazone compound (I) or anile compound (II) to the charge transport layer, like the case of the photosensitive layer in the element of FIG. 2, is in the range of from about 10 to 95% by weight, preferably from about 30 to 90% by weight. In this context, it is to be noted that a plasticizer may be used in conjunction with a binder in the preparation of the respective elements illustrated in FIGS. 1 to 3.
In the case of the element according to this invention, as the conductive substrate there can be employed a metallic plate or foil of aluminum or the like, an aluminum or the like evaporation deposited plastic film, a conductively treated paper or the like. As the binder suitably used for this invention there may be enumerated condensation resins such as polyamide, polyurethane, polyester, epoxy resin, polyketone, polycarbonate, etc., vinyl polymers such as polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, polyacrylamide, etc., and the like. However, it is to be noted that any insulating as well as adhesive resin may be employed. As the plasticizer for use in this invention there may be enumerated paraffin halide, polybiphenyl chloride, dimethylnaphthalene, dibutyl phthalate and so forth. The sensitizing dyes suitably used in the element of FIG. 1 include triarylmethane dyes such Brilliant Green, Victoria Blue B, Methyl Violet, Crystal Violet, Acid Violet 6B and the like; Xanthene dyes such as Rhodamine B, Rhodamine 6G, Rhodamine G Extra, Eosine S, Erythrosine, Rose Bengale, fluorescene and the like; thiazine dyes such as Methylene Blue and the like; cyanine dyes such as cyanine and the like; pyrylium dyes such as 2,6-diphenyl-4-(N,N-dimethylaminophenyl) thiapyrylium perchlorate, benzo pyrylium salt disclosed in Japanese Patent Publication No. 25658/1973 and the like; and so forth. The charge generation materials for use in the elements of FIGS. 2 and 3 include azo pigments comprised of inorganic pigments such as selenium, selenium-tellurium, cadmium sulfide, cadmium sulfide-selenium, etc. and organic pigments such as CI Pigment Blue-25 (CI 21180), CI Pigment Red 41 (CI 21200), CI Acid Red 52 (CI 45100), CI Basic Red 3 (CI 45210), the azo pigment having a carbazole skeleton (U.S. Ser. No. 872,679), the azo pigment having a styryl stilbene skeleton (U.S. Ser. Nos. 898,130 and 961,963), the azo pigment having a triphenylamine skeltone (U.S. Ser. No. 897,508), the azo pigment having a dibenzothiophene skeleton (U.S. Ser. No. 925,157), the azo pigment having an oxadiazole skeleton (U.S. Ser. No. 908,116), the azo pigment having a fluorenone skeleton (U.S. Ser. No. 925,157), the azo pigment having a bisstilbene skeleton (U.S. Ser. No. 922,526), the azo pigment having a distyryloxadiazole skeleton (U.S. Ser. No. 908,116), the azo pigment having a distyrylcarbazole skeleton (U.S. Ser. No. 921,086), etc.; phthalocyanine type pigments such as CI Pigment Blue 16 (CI 74100), etc.; indigo type pigments such as CI Bat Brown 5 (CI 73410), CI Bat Dye (CI 73030), etc.; perylene type pigments such as Argoscarlet B (available from Bayer Company), Indanthrene Scarlet R (available from Bayer Company) and so forth.
In this connection, it is to be noted that any one of the thus obtained elements can provide an adhesive or barrier layer, if needed, between the conductive substrate and the photosensitive layer. The materials suitably available for said adhesive or barrier layer include polyamide, nitrocellulose, aluminum oxide, etc., and preferably the film of said layer is 1 micron or less thick.
The copying process using the element of this invention comprises electrifying the surface of the element, exposing the same to light, thereafter developing and, if needed, transferring the thus formed image to another surface, such as paper.
The element according to this invention is advantageous in that it is generally of a high sensitivity and rich in flexibility.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Example 1
To 2 parts of Dian Blue (CI 21180) were added 98 parts of tetrahydrofuran. The resulting mixture was pulverized and mixed in a ball mill, thereby obtaining a charge generation pigment solution. This solution was coated onto an aluminum evaporation deposited polyester film by means of a doctor blade and air-dried thereby to form a 1 micron-thick charge generation layer. Subsequently, a charge transport layer forming solution was obtained by mixing 2 parts of hydrazone having the structural formula 17, 3 parts of polycarbonate resin (available under the Trademark Panlite L from TEIJIN) and 45 parts of tetrahydrofuran and well dissolving. This solution was coated onto said charge generation layer by means of a doctor blade and the same was dried at 100° C. for 10 minutes, thereby forming a charge transport layer being about 10 minutes thick. The instant element was thus prepared. This element was subjected to -6 KV corona discharge for 20 seconds by means of an electrostatic copying paper tester (SP 428 type available from KAWAGUCHI DENKI SEISAKUSHO K.K.) and charged negatively. Thereafter, the negatively charge element was left standing in the dark for 20 seconds for measuring the surface potential Vpo (V) at that time, and then was exposed to light from a tungsten lamp so that the surface intensity became 20 lux. Thus, the time (second) required until the surface potential was reduced to half of Vpo was calculated to determine the exposure amount E1/2(lux·sec). The obtained results showed: Vpo=-670 V and E1/2=3.3 lux·sec.
Example 2
A solution consisting of 3 parts of ##STR7## 1 part of polyester resin (Polyester Adhesive 49000 available from du Pont) and 96 parts of tetrahydrofuran was pulverized and mixed in a ball mill, thereby obtaining a charge generation pigment dispersion. This dispersion was coated onto an aluminum evaporation deposited polyester film by means of a doctor blade, and the same was dried for 5 minutes in a drying machine heated to 80° C., thereby forming a 1 micron-thick charge generation layer. Subsequently, a charge transport layer forming solution was obtained by mixing 2 parts of hydrazone having the structural formula 5, 3 parts of polycarbonate resin (available under the trademark Panlite L from TEIJIN) and 45 parts of tetrahydrofuran and dissolving. This solution was coated onto said charge generation layer by means of a doctor blade and the same was dried at 100° C. for 10 minutes, thereby forming a charge transport layer being about 10 microns thick. The element of this invention was thus obtained.
This element was charged negatively as in Example 1 and measured as to Vpo and E1/2 respectively with the results: Vpo=-670 V and E1/2=9.1 lux·sec.
Example 3 and 4
The same procedure as Example 2 was repeated with the exception that the charge generation pigment and the charge transport material were replaced. The thus obtained results are as shown in Table 1.
TABLE 1__________________________________________________________________________ Charge transportEx. Charge generation pigment material Vpo E1/2__________________________________________________________________________ ##STR8## 20 V 1270 7.5 lux . sec4 ##STR9## 28 V 890 6.8 lux . sec ##STR10##__________________________________________________________________________
Example 5
The elements obtained according to Example 1 through 4 were charged negatively by means of a commercially available copying machine. The thus charged elements were then exposed through an original to light, thereby permitting an electrostatic latent image to be formed thereon. This electrostatic latent image was developed using a positively charged toner-containing dry developer. The thus developed image was electrostatically transferred onto the surface of paper (wood free paper) and fixed, whereby a clear-cut image was obtained. A clear-cut image was obtained likewise in the case of using a wet developer.
Example 6
Selenium was applied onto an about 300 microns-thick aluminum plate by means of vacuum evaporation method so as to be 1 micron thick, thereby forming a charge generation layer. Subsequently, 2 parts of hydrazone having the structural formula 9, 3 parts of polyester resin (Polyester Adhesive 49000 available from du Pont) and 45 parts of tetrahydrofuran were mixed and dissolved to thereby obtain a charge transport layer forming solution. This solution was coated onto the said charge generation layer (selenium evaporation deposited layer) by means of a doctor blade, air-dried and then dried again at reduced pressure to form thereon a charge transport layer being about 10 microns thick. The element of this invention was thus obtained.
This element was measured as to Vpo and E1/2 in accordance with the same procedure as that of Example 1 with the results: Vpo=-910 V and E1/2=9.5 lux·sec.
Example 7
In place of the selenium of Example 6 there was employed a perylene type pigment having the following formula: ##STR11## This pigment was coated onto the plate by means of vacuum evaporation method so as to be 0.3 micron thick, thereby forming a charge generation layer. Subsequently, an element similar to that of Example 6 was prepared with the exception that a charge transport material having the structural formula (9) was employed. This element showed the results: Vpo=-670 V and E1/2=5.1 lux·sec.
Example 8
The elements obtained according to Example 6 and Example 7 were charged negatively by means of a commercially available copying machine. The thus charged elements were then exposed through an original to light, thereby permitting an electrostatic latent image to be formed thereon. This electrostatic latent image was developed using a positively charged toner-containing dry developer. The thus developed image was electrostatically transferred onto the surface of paper (wood free paper) and fixed, whereby a clear-cut image was obtained. A clear-cut image was obtained likewise in the case of using a wet developer.
Example 9
A mixture of 1 part of Chlor Dian Blue and 158 parts of tetrahydrofuran was pulverized and mixed in a ball mill. Subsequently, the thus treated mixture was added with 12 parts of hydrazone compound having the structural formula 29 and 18 parts of polyester resin (Polyester Adhesive 49000 available from du Pont) and subjected to further mixing, thereby obtaining a photosensitive layer forming solution. This solution was coated onto an aluminum evaporation deposited polyester film by means of a doctor blade and the same was dried at 100° C. for 30 minutes to thereby form a photosensitive layer being about 16 microns thick. The element of this invention was thus obtained.
This element was positively charged with +6 KV discharge using the same device as that employed in Example 1 and likewise measured as to Vpo and E1/2 with the results: Vpo=710 V and E1/2=15.7 lux·sec.
Example 10 through 12
Elements were prepared in accordance with the element preparation method similar to Example 9 with the exception that the charge generation pigment and charge transport material were replaced by those as shown in Table 2. These elements were subjected to the measurements similar to Example 1. The obtained results were as shown in Table 2.
TABLE 2__________________________________________________________________________ Charge transportExample Charge generation pigment material Vgo E1/2__________________________________________________________________________10 ##STR12## (1) V 690 lux . sec 8.511 ##STR13## (18) 870 10.712 ##STR14## (25) 810 8.9__________________________________________________________________________
Example 13
The elements obtained according to Example 9 through 12 were charged positively by means of a commercially available copying machine. The thus charged elements were then exposed through an original to light, thereby permitting an electrostatic latent image to be formed thereon. This electrostatic latent image was developed using a negatively charged toner-containing dry developer. The thus developed image was electrostatically transferred onto the surface of paper (wood free paper) and fixed, whereby a clear-cut image was obtained. A clear-cut image was obtained likewise in the case of using a wet developer.
Example 14
To 2 parts of Dian Blue (CI 21180) were added 98 parts of tetrahydrofuran. The resulting mixture was pulverized and mixed in a ball mill, thereby obtaining a charge generation pigment solution. This solution was coated onto an aluminum evaporation deposited polyester film by means of a doctor blade and air-dried thereby to form a 1 micron-thick charge generation layer. Subsequently, a charge transport layer forming solution was obtained by mixing 2 parts of anile compound having the structural formula 35, 3 parts of polycarbonate resin (Panlite L available from TEIJIN) and 45 parts of tetrahydrofuran and well dissolving. This solution was coated onto said charge generation layer by means of a doctor blade and the same was dried at 100° C. for 10 minutes, thereby forming a charge transport layer being about 10 microns thick. The element of the instant invention was thus obtained. This element was subjected to -6 KV corona discharge for 20 seconds by means of an electrostatic copying paper tester used in Example 1 and charged negatively. Thereafter, the negatively charged element was left standing in the dark for 20 seconds for measuring the surface potential Vpo (V) at that time, and then was exposed to light from a tungsten lamp so that the surface intensity became 20 lux. Thus, the time (second) required until the surface potential was reduced to half of Vpo was calculated to determine the exposure amount E1/2 (lux·sec). The obtained results showed: Vpo=-1070 V and E1/2=9.7 lux·sec.
EXAMPLE 15
A solution consisting of 3 parts of ##STR15## 1 part of polyester resin (Polyester Adhesive 49000 available from du Pont) and 96 parts of tetrahydrofuran was pulverized and mixed in a ball mill, thereby obtaining a charge generation pigment dispersion. This dispersion was coated onto an aluminum evaporation deposited polyester film by means of a doctor blade and the same was dried for 5 minutes in a drying machine heated to 80° C., whereby a 1 micron-thick charge generation layer was formed. Subsequently, a charge transport layer forming solution was obtained by mixing 2 parts of anile compound having the structural formula 37, 3 parts of polycarbonate resin (available under the trademark Panlite L from TEIJIN) and 45 parts of tetrahydrofuran and well dissolving. This solution was coated onto said charge generation layer by means of a doctor blade and the same was dried at 100° C. for 10 minutes to thus form a charge transport layer being about 10 microns thick. The element of the instant invention was thus obtained.
This element was charged negatively as in Example 14 and measured as to Vpo and E1/2 with the results: Vpo=-1250 V and E1/2=7.1 lux·sec.
EXAMPLE 16 and 17
Elements were prepared in the same manner as Example 15 with the exception that different kinds of charge generation pigments and charge transport materials were employed. The results with such elements were as shown in Table 3.
TABLE 3__________________________________________________________________________Ex- Chargeam- transportple Charge generation pigment material Vpo E1/2__________________________________________________________________________16 ##STR16## 38 V 670 lux . sec 2.517 ##STR17## 35 V 830 2.1 ##STR18##__________________________________________________________________________
EXAMPLE 18
The elements obtained according to Example 14 through 17 were charged negatively by means of a commercially available copying machine. The thus charged elements were then exposed through an original to light, thereby permitting an electrostatic latent image to be formed thereon. This electrostatic latent image was developed using a positively charged toner-containing dry developer. The thus develped image was electrostatically transferred onto the surface of paper (wood free paper) and fixed, whereby a clear-cut image was obtained.
A clear-cut image was obtained likewise in the case of using a wet developer.
Example 19
Selenium was applied onto an about 300 microns-thick aluminum plate by means of vacuum evaporation method so as to be 1 micron-thick, thereby forming a charge generation layer. Subsequently, 2 parts of anile compound having the structural formula 31, 3 parts of polyester resin (available under the trademark Polyester Adhesive 4900 from du Pont) and 45 parts of tetrahydrofuran were mixed and dissolved to thereby obtain a charge transport layer forming solution. This solution was coated onto said charge generation layer (selenium evaporation deposited layer) by means of a doctor blade, air-dried and then further dried at a reduced pressure to form thereon a charge transport layer being about 10 microns thick thereon. The element of the instant invention was thus obtained.
This element was measured as to Vpo and E1/2 in accordance with the same procedure as that of Example 14. The obtained results showed that Vpo=-830 V and E1/2=3.3 lux·sec.
EXAMPLE 20
In place of the selenium of Example 19 there was employed a perylene type pigment having the following formula: ##STR19## This pigment was coated onto the plate by means of vacuum evaporation method so as to be 0.3 micron thick, thereby forming a charge generation layer. Subsequently, an element similar to that of Example 19 was prepared with the exception that an anile compound having the structural formula 39 was employed as the charge transport material. This element showed the results: Vpo=-810 V and E1/2=5.5 lux·sec.
EXAMPLE 21
The elements obtained according to Example 19 and Example 20 were charged negatively by means of a commercially available copying machine. The thus charged elements were then exposed through an original to light, thereby permitting an electrostatic latent image to be formed thereon. This electrostatic latent image was developed with a positively charged toner-containing dry developer. The thus developed image was electrostatically transferred onto the surface of paper (wood free paper) and fixed, whereby a clear-cut image was obtained. A clear-cut image was obtained likewise in the case of using a wet developer.
EXAMPLE 22
A mixture of 1 part of Chlor Dian Blue and 158 parts of tetrahydrofuran was pulverized and mixed in a ball mill. Subsequently, the thus treated mixture was added with 12 parts of anile compound having the structural formula 49 and 18 parts of polyester resin (available under the trademark Polyester Adhesive 49000 from du Pont) and subjected to further mixing, thereby obtaining a photosensitive layer forming solution. This solution was coated onto an aluminum evaporation deposited polyester film by means of a doctor blade and the same was dried at 100° C. for 30 minutes to thereby form a photosensitive layer being about 16 microns thick. The element of this invention was thus obtained.
This element was positively charged with +6 KV corona discharge using the same device as that employed in Example 14 and likewise measured as to Vpo and E1/2 with the results: Vpo=1450 V and E1/2=3.9 lux·sec.
Example 23 through 25
Elements were prepared in accordance with the element preparation method similar to Example 22 with the exception that the charge generation pigment and charge transport material were replaced by those as shown in Table 4. These elements were subjected to the measurements similar to Example 14. The results thus obtained were as shown in Table 4.
TABLE 4__________________________________________________________________________ Charge transportExample Charge generation pigment material Vpo E1/2__________________________________________________________________________23 ##STR20## 41 V 870 lux . sec 7.724 ##STR21## 43 V 910 5.925 ##STR22## 46 980 5.7__________________________________________________________________________
EXAMPLE 26
The elements obtained according to Example 22 through 25 were charged positively by means of a commercially available copying machine. The thus charged elements were then exposed through an original to light, thereby permitting an electrostatic latent image to be formed thereon. This electrostatic latent image was developed using a negatively charged toner-containing dry developer. The thus developed image was electrostatically transferred onto the surface of paper (wood free paper) and fixed, whereby a clear-cut image was obtained. A clear-cut image was obtained likewise in the case of using a wet developer.
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An electrophotographic element comprising a conductive substrate and a mono-layer type or multi-layer type photosensitive layer, superposed thereon, containing a photoconductive material in which said photoconductive material is a hydrazone compound having the following general formula (I) or an anile compound having the following general formula (II): ##STR1## [where R 1 is a methyl, ethyl 2-hydroxyethyl or 2-chloroethyl group; R 2 is a methyl, ethyl, benzyl or phenyl group; and R 3 is chlorine, bromine, a C 1 -C 4 alkyl group, a C 1 -C 4 alkoxy group, a dialkylamino group with C 1 -C 4 alkyl or a nitro group.] ##STR2## [where R 1 is the same as the said general formula (I); and R 4 is a substituted or non-substituted phenyl, naphthyl, heterocyclic or C 1 -C 10 alkyl group.]
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This application is a continuation application of U.S. patent application Ser. No. 11/405,913, filed Apr. 17, 2006, now U.S. Pat. No. 8,071,259, issued Dec. 6, 2011, which in turn is a divisional application of U.S. patent application Ser. No. 09/910,959, filed Jul. 24, 2001, now abandoned; the disclosures of which are hereby incorporated by reference into the present disclosure.
INTRODUCTION AND BACKGROUND
The present invention provides noble metal-containing nanoparticles for producing membrane electrode assemblies (MEAs) for fuel cells, in particular for low temperature fuel cells, for example polymer electrolyte membrane fuel cells (PEM fuel cells) and direct methanol fuel cells (DMFC). New types of colloidal solutions which contain the noble metal alone or in association with other metals are described, wherein the metals are in the form of nanoparticles embedded in a temporary stabilizer. The nanoparticles are used to produce electrocatalysts and catalysed components for fuel cells. Using these nanoparticles, catalyzed ionomer membranes, catalyzed gas diffusion electrodes (so-called “backings”) and membrane electrode assemblies can be produced.
Fuel cells convert a fuel and an oxidizing agent which are spatially separated from each other at two electrodes into electricity, heat and water. Hydrogen or a hydrogen-rich gas may be used as the fuel, and oxygen or air as the oxidizing agent. The process of energy conversion in the fuel cell is characterized by a particularly high efficiency. For this reason, fuel cells in combination with electric motors are becoming more and more important as an alternative to traditional internal combustion engines. The PEM fuel cell is suitable for use as an energy converter in motor vehicles because of its compact structure, its power density and its high efficiency.
The PEM fuel cell consists of a stacked arrangement (“stack”) of membrane electrode assemblies (MEAs), between which are arranged bipolar plates for supplying gas and conducting electricity. A membrane electrode assembly consists of a solid polymer electrolyte membrane, both sides of which are provided with reaction layers which contain catalysts. One of the reaction layers is designed as an anode for the oxidation of hydrogen and the second reaction layer is designed as a cathode for the reduction of oxygen. On these reaction layers are mounted so-called gas distributor structures or gas diffusion layers made of carbon fibre paper, carbon fibre woven fabric or carbon fleece, which facilitate good access by the reaction gases to the electrodes and effective removal of the cell current. The anode and cathode contain so-called electrocatalysts which catalytically support the particular reaction (oxidation of hydrogen at the anode and reduction of oxygen at the cathode). Metals from the platinum group in the periodic system of elements are preferably used as the catalytically active components. In the majority of cases, so-called supported catalysts, in which the catalytically active platinum group metal has been applied in highly dispersed form to the surface of a conductive support material, are used.
The polymer electrolyte membrane consists of proton-conducting polymer materials. These materials are also called ionomers for short in the following. A tetrafluorethylene/fluorovinylether copolymer with acid functions, in particular sulfonic acid groups, is preferably used. Such materials are sold, for example, under the tradenames Nafion® (E.I. DuPont) or Flemion® (Asahi Glass Co.). However, other, in particular fluorine-free, ionomer materials such as sulfonated polyetherketones or polyarylketones or polybenzimidazoles but also ceramic materials can be used.
The performance data for a fuel cell depends critically on the quality of the catalyst layers applied to the polymer electrolyte membrane. These layers usually consist of an ionomer and a finely divided electrocatalyst dispersed therein. Together with the polymer electrolyte membrane, so-called three-phase interfaces are formed in these layers, wherein the ionomer is in direct contact with the electrocatalyst and the gases (hydrogen at the anode, air at the cathode) introduced to the catalyst particles via the pore system.
To prepare the catalyst layers, ionomer, electrocatalyst and optionally other additives are generally blended to form an ink or a paste. To produce the catalyst layer, the ink is applied by brushing, rolling, spraying, doctor blading or printing either to the gas diffusion layer (e.g. carbon fleece or carbon fibre paper) or directly to the polymer membrane, dried and optionally subjected to a secondary treatment. In the case of coating the ionomer membrane with a catalyst layer, the non-catalyzed gas diffusion layers are then mounted on the membrane on the anode and cathode faces and a membrane electrode assembly is then obtained. Alternatively, the catalyst layers may also be applied to the gas diffusion layers. These gas diffusion electrodes (gas diffusion layers plus catalyst layers) are then laid on the two faces of the ionomer membrane and laminated with this, wherein a membrane electrode assembly is also obtained. The prior art in this area is described in patent documents U.S. Pat. Nos. 5,861,222, 5,211,984 and 4,876,115.
The present invention provides noble metal-containing nanoparticles which can be used for the production of catalyzed components and membrane electrode assemblies for low temperature fuel cells (PEMFC, DMFC, AFC or PAFC). The object of the invention are new types of preparations, or colloidal solutions, of noble metal-containing nanoparticles which are embedded in a suitable temporary stabilizer.
Colloidal nanoparticle solutions have been known for a long time. For example, they are used to produce noble metal supported catalysts. Thus, U.S. Pat. No. 3,992,512 describes a process in which colloidal platinum oxide nanoparticles are prepared by decomposing platinum sulfite acid, fixing these to a supporting carbon black and then reducing to platinum. The process is complicated and expensive and provides only electrocatalysts which are contaminated with sulfur due to using sulfur-containing precursor compounds for the platinum. Stabilizers are not used.
DE 197 54 304 A1 describes platinum-containing nanoparticles which are embedded in a polymeric betaine. Polymeric carbobetaine, phosphobetaine and sulfobetaine, which are built up from a non-branched polymethylene main chain and side chains with different types of betaine groups having degrees of polymerization of 50 to 10,000, are described. The method for decomposing these stabilizers is not described. It has been shown that these stabilizers adhere firmly to the noble metal surface, due to their long polymethylene main chains, and thus contaminate the catalytically active catalyst surfaces. For this reason, these nanoparticles are not very suitable as catalytically active species for membrane electrode assemblies in fuel cells. Nothing is reported about the further processing of these in order to produce catalyzed systems (catalysed ionomer membranes, gas diffusion electrodes, etc.).
Furthermore, DE 44 43 705 A1 discloses noble metal colloids which are stabilized with surfactants (such as, for example, fatty alcohol polyglycol ethers or amphiphilic betaines) and can be used for preparing supported electrocatalysts. After attaching these noble metal colloids to the support material, aftertreatment is required in order to remove the surfactants used for stabilizing purposes. During this aftertreatment (generally thermal pyrolysis at temperatures above 400° C.) the colloid particles sinter so that coarse crystallites are produced.
Furthermore, DE 197 45 904 A1 describes a polymer-stabilized metal colloid solution which contains a cation exchange polymer for stabilizing purposes. Here, the noble metal nanoparticles are precipitated in the presence of an ionomer solution (e.g. Nafion®) and isolated as a dry powder. Investigations by the inventors of the present invention have shown that this process does not lead to stable liquid colloid preparations because the ionomer has no surfactant properties and in addition is itself present as particles in the size range 5 to 20 nm (see also X. Cheng et al., J. Power Sources 79 (1999) 75-81). In addition, our work has shown that this process has considerable disadvantages because it provides nanoparticles which are heavily contaminated with foreign ions such as, for example, chloride or sodium. The presence of chloride in particular leads to corrosion and reduced resistance to ageing of the catalyst components prepared using this metal colloid preparation.
Therefore it is the object of the present invention to provide noble metal-containing nanoparticles which form stable solutions over a long time due to the use of a suitable, temporary, stabilizer and contain only marginal amounts of impurities (halogen ions, alkali metal ions, borate, etc.), which are insignificant for use in fuel cells. They are intended to be used directly for catalyzing ionomer membranes and gas diffusion layers for PEM fuel cells, which means that the temporary stabilizer (or protective colloid) has to be completely removable by means of a gentle process without damaging the polymer electrolyte membrane. Furthermore, the nanoparticles are intended to be capable of being prepared in aqueous medium without the addition of organic solvents.
SUMMARY OF THE INVENTION
This object is achieved, according to the invention, by nanoparticles which contain the noble metals only or noble metals in combination with base metals and are characterised in that they are embedded in an aqueous solution of a temporary stabilizer based on a polysaccharide.
According to the invention, polysaccharides are used to stabilize the nanoparticles. Suitable polysaccharides are described in Ullmanns Enzyklopädie der technischen Chemie, 4th edition, vol. 19, p. 233 et seq. Polysaccharides are water soluble, highly polymer carbohydrate compounds, which consist of monosaccharide units linked together by a so-called glycosidic bond. When forming this bond, the anomeric hydroxyl group of the monosaccharide reversibly condenses with the hydroxy group of another monosaccharide to form a disaccharide, oligo- or finally a polysaccharide molecule. A single polysaccharide molecule can contain up to several ten thousands of various monosaccharide units. Polysaccharides, which are composed of various types of monosaccharide units are called heteropolysaccharides, those which contain only one monosaccharide type are called homopolysaccharides. The polysaccharides differ in their molecular weight, their composition and, most important, in their water solubility.
It was discovered that the polysaccharides suitable for use in the present invention must be highly water soluble. Most common polysaccharides and gums cannot be dissolved in water at concentrations higher than about 5 wt. % because of their very high viscosities and their gelling behaviour. The preferred polysaccharides exhibit a water solubility of about 5 to 40 wt. % while still maintaining a low viscosity solution. The preferred polysaccharides are heteropolysaccharides such as gum arabic, xanthan gum, tragacanth gum or mixtures thereof.
Furthermore it was found that the water based solution of the polysaccharide has to be preferably in the pH neutral form. A. pH range of 5 to 8, preferably 5.5 to 7.5 and most preferably 6 to 7 is required to ensure stability of the polysaccharide. At a lower, more acidic pH, as well as at higher alkaline pH values, the glycosidic bonds of the polysaccharide are broken up and the macromolecule is destroyed. This effect is used in turn to remove traces of the stabilizer after the colloidal noble metal particles have been deposited on the suitable substrate material (ionomer membranes, gas diffusion electrodes or carbon black supports) as described further below in this invention.
When properly selected, the stabilizers mentioned are able to keep the colloidal preparation of nanoparticles, even in high concentrations, stable for a long time. For this purpose, it has proven advantageous to adjust the ratio by weight of nanoparticles to stabilisers to a value between 10:1 and 1:10, preferably between 5:1 and 1:5.
The temporary stabilizers used have to be capable of being removed effectively. Particularly important here is an easy decomposition (i.e. breaking down of the main chain in the polymer into low molecular weight fragments). During the course of trials, it has been shown that the polysaccharides are extremely suitable as temporary stabilisers. As described previously, in these compounds, the glycosidic bonds between the individual monosaccharides or sugar monomers break readily when treated with acids or alkalis. They depolymerize and break down into low molecular weight constituents. This decomposition process also takes place during pyrolysis at temperatures up to 250° C. The low molecular weight fragments can be readily removed, for example by washing out.
Nanoparticles according to the invention may contain one or more noble metals and optionally in addition at least one base metal. Nanoparticles according to the invention preferably contain at least one noble metal from the group platinum, palladium, rhodium, iridium, ruthenium, osmium, gold and silver. Suitable base metals are iron, cobalt, nickel, copper, titanium, vanadium, chromium, manganese, molybdenum, tungsten and rhenium. The particle size of the nanoparticles is between 0.1 and 100, preferably between 1 and 20 and in particular between 1 and 5 nm. The particle size can be determined by means of transmission electron microscopy (TEM).
The concentration of noble metal nanoparticles in the aqueous colloid solution is 0.01 to 500 g/l (0.001 to 50 wt %), typically 0.1 to 200 g/l (0.01 to 20 wt. %).
Nanoparticles according to the invention can be obtained by reducing precursor compounds of the desired noble metals and optionally base metals with a total chlorine concentration of less than 500 ppm in an aqueous solution in the presence of the stabiliser, using a reducing agent.
Suitable reducing agents for the preparation according to the invention are those which decompose to produce no residues or which leave behind no problematic ionic or organic impurities during the reduction process. Examples of these are hydrogen, hydrazine, formaldehyde, or else lower aliphatic alcohols such as ethanol or isopropanol which decompose to give gaseous constituents due to the reduction reaction. The reducing agent is added directly to the reaction solution, with stirring, wherein temperatures of up to 95° C. are optionally used. After completion of the reduction the colloidal solution of the nanoparticles in principle does not contain any more reducing agents. Surplus reducing agents are destroyed due to treatment at elevated temperatures of up to 95° C.
The following halogen-free, or low-halogen, compounds are used, for example, as noble metal precursor compounds for preparing the nanoparticles:
for Pt: hexahydroxoplatinic (IV) acid, ethylammonium hexahydroxoplatinate, tetraammineplatinum (II) nitrate, platinum (IV) nitrate, tetraammineplatinum (II) hydroxide solution for Pd: tetraamminepalladium(II) nitrate, palladium(II) nitrate, palladium(II) sulfate hydrate for Ru: trinitratonitrosylruthenium (II), ruthenium (III) oxalate hydrate etc. for Rh: rhodium (III) nitrate hydrate, rhodium (III) sulfate solution etc.
Corresponding compounds may also be used for the noble metals Au, Ag, Ir and Os. The precursor compounds used for the base metals mentioned are chlorine-free salts of the base metals, preferably nitrate compounds.
In general, the total chlorine content of the precursor compounds used should be less than 500 ppm. Determination of the total chlorine content includes both the free and also the bonded chlorine and is performed, for example, by ion chromatography (IC), in aqueous solution, after working up the substance in a suitable manner.
The total chlorine content of the noble metal solution according to the invention is typically less than 100 ppm, preferably less than 50 ppm.
Nanoparticles according to the invention may be used to prepare supported electrocatalysts. A particular advantage of the nanoparticles, however, is that they can also be used directly, that means without a support, to prepare catalyst layers for ionomer membranes and gas diffusion layers and also to impregnate the ionomer membranes themselves.
In the following, some of these types of use are described in more detail.
For the preparation of supported electrocatalysts, the noble metal nanoparticles are deposited onto a suitable carbon black material. Several methods (for example impregnation, soaking or incipient wetness type methods and others) can be used for this process. Hereby, electrocatalysts exhibiting a very high noble metal dispersion (i.e. noble metal surface area) are obtained, even at very high noble metal loading of the carbon black support. Investigations of the present inventors have shown, that electrocatalysts with a noble metal loading of up to 80 wt. % on carbon black can be prepared with particle sizes in the range of 2 to 5 nanometer. After depositing the nanoparticles on the carbon black support, the stabilizer can be removed under mild conditions, that is with acidic or alkaline hydrolysis or by thermal decomposition at temperatures of up to 250° C.
Direct use of the nanoparticles for catalysing the various components in a fuel cell is enabled in that the protective colloid, or temporary stabilizer, decomposes under relatively mild conditions and can be washed out so that damage to the components in the fuel cell does not occur. This produces a considerable simplification in and reduction in costs of the production process for membrane electrode assemblies. In addition, the process has the advantage that the high surface area and dispersion of the nanoparticles is retained and is not distorted by high temperature tempering processes. This leads to very good performance by the membrane electrode assemblies prepared in this way so that the platinum loading can be kept low.
In the case of coating an ionomer membrane, the preparation with the nanoparticles, optionally mixed with other additives such as, for example, dissolved ionomer, carbon black or further electrocatalysts, is applied to the membrane in a spray process, by brushing or immersing or by means of screen printing. After coating, the temporary stabilizer is decomposed by treating with acid or alkali and it is then washed out. Dissolved ionomer is obtainable in aqueous solution with low molecular weight aliphatic alcohols (Fluka, Buchs; Aldrich, Steinheim). Aqueous solutions of the ionomer in higher concentrations (10 wt. % and 20 wt. %) can be prepared therefrom.
Ionomer membranes and also the ionomer contained in the catalyst layers can be used in an acidic proton-conducting H + form or, after exchanging the protons for monovalent ions such as, for example, Na + and K + , in a non-acidic Na + or K + form for preparing membrane electrode assemblies. The non-acidic form of polymer membranes is usually more stable towards thermal stress than the acidic form and is therefore preferably used. Before using the membrane electrode assembly, however, the polymer electrolyte has first to be returned to its acidic, proton-conducting form. This is achieved by so-called reprotonation. Reprotonation is performed by treating the membrane electrode assembly in sulfuric acid.
Reprotonation with sulfuric acid can therefore be combined in a simple manner with decomposition of the temporary stabilizer. This simplifies the production process for membrane electrode assemblies. The ionomer membrane catalyzed in this way is then completed with 2 gas diffusion electrodes to give a 5-layered membrane electrode assembly.
As an alternative to coating the ionomer membrane, the gas diffusion layers may also be coated with the catalytically active component. For this purpose, the colloidal preparation of nanoparticles, optionally with the additives mentioned above, is applied to a gas diffusion layer (gas distribution structure or “backing” consisting of carbon fibre paper) using an appropriate method. The stabilizer is then removed by a tempering process at temperatures below 250° C. and the catalysed electrode, as the anode and cathode, are further laminated with an ionomer membrane to give a 5-layered membrane electrode assembly.
Furthermore, the colloidal noble metal nanoparticles may also be processed to give a catalyst ink. Suitable catalyst inks are described, for example, in patent specification U.S. Pat. No. 5,861,222 in the name of the applicant, wherein the supported catalysts used there may be replaced entirely or partly by noble metal nanoparticles according to the invention.
The colloidal solution of noble metal nanoparticles is also suitable for precatalyzing ionomer membranes by impregnating the ionomer membrane in the solution. In further steps, a catalyst ink is then applied to the precatalyzed ionomer membrane, as described in the US patent specification mentioned above. However, the precatalyzed ionomer membrane may also be assembled, together with catalysed gas diffusion electrodes on the cathode and anode faces, and laminated to produce a 5-layered membrane electrode assembly.
In a further type of use, a thin layer of the colloidal noble metal particles according to the invention is also applied to a catalysed gas diffusion electrode, for example by spraying or brushing. The multi-catalyzed gas diffusion electrodes are then combined with the ionomer membrane in a sandwich structure and optionally laminated.
In addition, combinations of the types of use described above are possible. All these methods for catalysing, due to the use of the colloidal noble metal particles according to the invention, lead to high catalytic activity and electrical performance in the membrane electrode assembly, and in the PEM fuel cell.
BRIEF DESCRIPTION OF DRAWINGS
The present invention will be further understood with reference to the accompanying drawing, wherein:
FIG. 1 is a schematic cross section of a polymer electrolyte membrane directly catalyzed with nanoparticles according to the invention;
FIG. 2 is a schematic cross section of an electrode backing directly catalyzed with nanoparticles according to the invention;
FIG. 3 is a schematic cross section of an membrane electrode assembly (MEA) with catalyst layers comprising a supported electrocatalyst and nanoparticles according to the invention; and
FIG. 4 is a schematic cross section of a 5-layered membrane electrode assembly according to the invention.
DETAILED DESCRIPTION OF INVENTION
Directly catalyzing the various components of a PEM fuel cell with noble metal nanoparticles is accomplished by applying the aqueous solution of the stabilized nanoparticles with no further additives to the components in question by a spray process, by brushing or immersing or by means of screen printing. After coating, the temporary stabilizer is decomposed by treating with acid or alkali (depending on the type of stabilizer) and is then washed out.
FIG. 1 visualises such a coating on the opposing surfaces of a polymer electrolyte membrane ( 1 ). The noble metal nanoparticles ( 2 ) are directly applied to the surfaces of the ionomer by a process as described above.
FIG. 2 shows a similar coating as in FIG. 1 on an electrode backing consisting of a hydrophobic gas diffusion layer ( 3 ) with a carbon black micro layer ( 4 ) on one of its surfaces. A micro layer consists of a mixture of a hydrophobic polymer and carbon black. The micro layer has a microporosity and serves as an intermediate layer between the gas diffusion layer and the catalyst layer of a MEA to improve the electronic connection between both. In FIG. 2 the noble metal nanoparticles ( 2 ) are directly deposited onto the micro layer. Since an electrode backing can withstand much higher temperatures than the polymer membrane (340° C. instead of only 150° C.) the temporary stabilizer can be decomposed in this case thermally by heating the coated electrode backing up to a temperature of 250° C.
FIG. 3 shows the structure of a polymer electrolyte membrane ( 1 ) coated with two catalyst layers ( 5 ) and ( 6 ). The catalyst layers comprise a supported electrocatalyst ( 7 ) and unsupported nanoparticles ( 8 ). The supported electrocatalyst and the unsupported nanoparticles are both dispersed in a matrix of a ionomer ( 9 ). The catalyst layers ( 5 ) and ( 6 ) may be the same or different. In the final fuel cell one of these catalyst layers functions as the anode and the other as the cathode of the fuel cell.
FIG. 4 visualizes a polymer electrolyte fuel cell comprising the membrane electrode assembly of FIG. 3 complemented by two electrode backings consisting of a hydrophobic gas diffusion layer ( 3 ) and a micro layer ( 4 ). Taking the electrode backings as one layer, the structure of FIG. 4 can be viewed as a 5-layered membrane electrode assembly.
The invention is explained in more detail in the following by the use of a few examples. In the examples, membrane electrode assemblies were prepared by using nanoparticles according to the invention and their electrochemical performance data were characterized.
For this purpose, the membrane electrode assemblies were processed to give PEM single cells and their characteristics (change in voltage/current density plot) were measured at a pressure of about 1 bar (abs.) when operated with hydrogen/air or with reformate/air. The size of each cell was 50 cm 2 , the cell temperature was 75° C. From the characteristic plots, the cell voltage obtained at a current density of 500 mA/cm 2 was recorded as a measure for the electrocatalytic performance of the cell.
EXAMPLE 1
a) Preparing Pt Nanoparticles
11.1 g of a solution of bis(ethanolammonium) hexahydroxoplatinate (Pt content 9 wt. %; total chlorine content <100 ppm; from dmc 2 , Hanau) were added dropwise to 1.5 l of fully deionized water in which 1.0 g of gum arabic (Merck) had previously been dissolved. Then, 1 l of ethanol was added with stirring and the resulting mixture was heated, wherein the mixture turned black. The solution was kept under reflux for one hour at 85° C. and then concentrated to a volume of 100 ml by evaporation. The colloidal solution prepared in this way had a pH value of 5.9 and contained 10 g Pt/1 (1 wt. % Pt) and 10 g/l (1 wt. %) of the stabilizer gum arabic. The ratio of Pt nanoparticles to stabilizer was thus 1:1. The total chlorine content of the solution was less than 10 ppm. The average size of the Pt particles was determined using TEM (transmission electron microscopy) and was 2 nm.
b) Catalyzing Ionomer Membranes
5.6 g of the colloidal solution (Pt content 1 wt. %) were dispersed with 0.4 g of an aqueous solution of Nafion (10 wt. % in water) and 0.1 g of carbon black (type: Vulcan XC-72, from Cabot) and the resulting ink was applied in a spray process to the front and rear faces of a Nafion membrane (type: Nafion 112, thickness 50 μm, from DuPont). Then drying was performed at temperatures of 80° C. in a circulating air oven. The total Pt loading on the front and rear faces of the membrane was 0.2 mg Pt/cm 2 . After drying, the catalyzed membrane was treated for 30 min in a sulfuric acid bath (0.5 normal, pH=0.3) and then washed with water. After that, it was placed between two non-catalyzed gas diffusion layers and incorporated into a PEM single cell.
When operating with hydrogen/air (pressureless operation, about 1 bar), a cell voltage of 600 mV was produced with a current density of 500 mA/cm 2 .
c) Catalyzing Gas Diffusion Electrodes
0.4 g of an aqueous solution of Nafion (10% in water) were added to 5.6 g of the colloidal solution (concentration: 1 wt. % Pt) and the mixture was applied in a spray process to two gas diffusion layers (type: Standard ELAT, ETEK, Natick, USA) provided, in a known manner, with a carbon black micro layer. The Pt loading on the anode electrode was 0.1 mg/cm 2 , that on the cathode electrode was 0.15 mg/cm 2 . Then drying was performed at temperatures of 80° C. in a circulating air oven and a tempering process was performed under nitrogen at 250° C. The electrodes prepared in this way were combined with an non-catalyzed membrane to give a 5-layered membrane electrode assembly which had a total Pt loading of 0.25 mg Pt/cm 2 . In a PEM single cell, very good performance values were obtained when operating with hydrogen/air (pressureless operation at about 1 bar; cell voltage: 600 mV with a current density of 500 mA/cm 2 ).
EXAMPLE 2
a) Preparation of Pt/Ru Nanoparticles
7.28 g of a solution of bis(ethanolammonium) hexahydroxoplatinate (Pt content 9 wt. %; total chlorine content <100 ppm; from dmc 2 , Hanau) and 2.265 g of a solution of ruthenium nitrosylnitrate (Ru content 15 wt. %, total chlorine content <200 ppm; from dmc 2 , Hanau) were added dropwise to 1.5 l of fully deionized water, in which 1.0 g of gum arabic (Merck) had been dissolved. Then 1 l of ethanol was added with stirring and the resulting mixture was heated, wherein it turned black. The solution was held under reflux for one hour at 85° C. and then concentrated by evaporation to a volume of 100 ml. The colloidal solution obtained in this way had a pH value of 5.7 and contained 10 g PtRu/1 (1 wt. % PtRu, atomic ratio 1:1) and 10 g/l (1 wt. %) of the stabiliser gum arabic. The ratio of PtRu nanoparticles to stabilizer was thus 1:1. The total chlorine content of the solution was less than 50 ppm. The average size of the PtRu particles was determined by TEM and was 2.5 nm.
b) Catalyzing an Ionomer Membrane
5.6 g of the colloidal solution (concentration: 1 wt. % PtRu) were dispersed with 0.4 g of an aqueous solution of Nafion (10% in water) and 0.1 g of carbon black (type: Vulcan XC-72, from Cabot) and the resulting ink was applied in a spray process to the anode face of a Nafion membrane (type: Nafion 112, thickness 50 μm, from DuPont). Then drying was performed at temperatures of 80° C. in a circulating air oven. The Pt loading on the membrane on the anode face was 0.1 mg Pt/cm 2 , the Ru loading was about 0.05 mg/cm 2 . Then the cathode face of the ionomer membrane was catalyzed in the way described in example 1 (Pt loading 0.1 mg/cm 2 ). After drying, the complete membrane was treated in a sulfuric acid bath (0.5 normal, pH=0.3) for 30 min and then washed with water. After that the membrane coated with catalyst was placed between 2 non-catalyzed gas diffusion layers and incorporated into a PEM single cell. The total noble metal loading was 0.2 mg Pt/cm 2 and 0.05 mg Ru/cm 2 . The single cell test produced very good performance values when operating with reformate/air (reformate composition: 60 vol. % hydrogen, 25 vol. % carbon dioxide, 15 vol. % nitrogen, 40 ppm CO, 2% air bleed, pressureless operation; cell voltage: 550 mV with a current density of 500 mA/cm 2 ).
EXAMPLE 3
2.22 g of a solution of bis(ethanolammonium) hexahydroxoplatinate (Pt content 9 wt. %; total chlorine content <100 ppm; from dmc 2 , Hanau) were added dropwise to 1.5 l of fully deionized water in which 0.2 g of Kelzan (xanthan gum, Lubrizol-Langer, Bremen) had previously been dissolved. Then 1 l of isopropanol was added with stirring and the resulting mixture was heated, wherein it turned black. The solution was held under reflux for one hour at 85° C. and then concentrated by evaporation to a volume of 100 ml. The colloidal solution obtained in this way had a pH value of 5.6 and contained 2 g Pt/l (0.2 wt. % Pt) and 2 g/l (0.2 wt. %) of the stabilizer Kelzan. The ratio of Pt nanoparticles to stabilizer was thus 1:1. The total chlorine content of the solution was less than 30 ppm. The average size of the Pt particles was determined by TEM and was 2.5 nm.
An ionomer membrane was catalyzed in the same way as described in example 1 and a membrane with a total platinum loading of 0.2 mg Pt/cm 2 was produced. In a PEM single cell, very good performance values were obtained when operating with hydrogen/air (pressureless operation; cell voltage: 630 mV with a current density of 500 mA/cm 2 ).
EXAMPLE 4
2.2 g of a solution of bis(ethanolammonium) hexahydroxoplatinate (Pt content 9 wt. %; total chlorine content <100 ppm; from dmc 2 , Hanau) were added dropwise to 1.5 l of fully deionized water in which 0.436 g of gum arabic (Merck, Darmstadt) and 0.137 g of chromium (III) nitrate nonahydrate (total chlorine content <20 ppm, Merck) had previously been dissolved. The solution thus contained 0.2 g Pt (about 1 mmol) and 0.018 g Cr (about 0.3 mmol) to prepare PtCr nanoparticles with a Pt:Cr-atomic ratio of 3:1. Then 1 g of hydrazine hydrate (24% strength solution, Merck) was added dropwise with stirring and the resulting mixture was heated, wherein it turned black. The solution was held at boiling point for one hour and then concentrated by evaporation to a volume of 100 ml. The colloidal solution obtained in this way contained 2.18 g PtCr (3:1)/1 and 4.36 g/l of the stabilizer gum arabic. The ratio of PtCr nanoparticles to stabilizer was thus 1:2. The total chlorine content of the solution was less than 30 ppm. The average size of the PtCr particles was determined by TEM and was about 3 nm.
An ionomer membrane was catalyzed in the way described in example 1. However, the cathode face of the membrane was coated with PtCr (3:1) nanoparticles and the anode face was coated with pure Pt nanoparticles. The membrane coated in this way had a total platinum loading of 0.2 mg Pt/cm 2 . Measurement in a PEM single cell when operating with hydrogen/air (pressureless operation, about 1 bar) provided very good results. The cell voltage was 720 mV with a current density of 500 mA/cm 2 .
EXAMPLE 5
Pt nanoparticles were prepared in the way described in example 1. To catalyse an ionomer membrane, the Pt nanoparticles were incorporated into a catalyst ink of the following composition:
15.0
g
Pt supported catalyst (40 wt. % Pt on carbon black)
50.0
g
Nafion solution (10% in water)
30.0
g
Pt nanoparticles (Pt content 1 wt. %)
5.0
g
Dipropylene glycol
100.0
g
The above catalyst ink contains a mixture of a conventional Pt supported catalyst and unsupported noble metal nanoparticles according to the invention.
The ink was applied in a screen printing process to the anode and cathode faces of an ionomer membrane (Nafion 112) to give a membrane electrode structure as shown in FIG. 3 . The total Pt loading was 0.5 mg/cm 2 . Measurement in a PEM single cell operating with hydrogen/air (pressureless operation, about 1 bar) provided very good results. The cell voltage was 710 mV with a current density of 500 mA/cm 2 .
Further variations and modifications of the present invention will be apparent to those skilled in the art from the foregoing and are intended to be encompassed by the claims appended hereto.
German priority application 100 37 071.3 of Jul. 29, 2000 is relied on and incorporated herein by reference.
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Nanoparticles which contain noble metals alone or noble metals in combination with base metals. The nanoparticles are embedded in an aqueous solution of a temporary stabilizer based on a polysaccharide.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] The present invention claims the benefit of U.S. provisional patent application 60/881,709 filed Jan. 22, 2007, the entire content and disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to a system and method for enabling service providers to create real-time reverse auctions for location based services. Specifically, the invention concerns matching of service providers to customers and more specifically to a market-maker using a system platform for matching service providers to a customer.
BACKGROUND OF THE INVENTION
[0003] The invention concerns a system and method that facilitates the matching of service providers based on certain criteria such as, but not limited to, location of the provider in relation to a customer location, customer requests based on the location of the customer, the type of service requested and other possible attributes such as customer profile, customer past behavior and preferences and service price and quality.
[0004] The invention will described using the example of an owner or driver of a disabled vehicle seeking automotive services, but it will be understood that the invention has many other applications where an auction for the providing of services to a customer is desirable.
[0005] As an example, the system and method of the invention can enable car towing service providers to bid in real time for providing a service to the driver of a car that became stranded on area roads.
[0006] The entity that is using the platform to match local service providers to the customer is referred to as the “market-maker”.
[0007] There are economic incentives for the various parties to the transaction. Market-makers may benefit by charging a fee to service providers in order to participate in the auction and, in some case, increasing revenue due to larger profit margins. Local service providers benefit from participating in the program by gaining access to revenue generating opportunities that they may not have otherwise been aware of. Furthermore, service providers who win the auction process may increase revenues through providing follow-on services for the customer.
[0008] The invention uses factors such as the specific location, customer and service information in order to allow a market-maker to create a reverse auction whereby local service providers can bid to win the opportunity of providing service corresponding to the customer's request.
[0009] Reverse auctions are those auctions where sellers compete for business opportunities, in contrast to traditional auctions where buyers compete to purchase a good or service. The goal of reverse auctions is to drive down the bidding price, while that of traditional auctions is to drive up the bidding price.
[0010] Market-makers (contracting organizations, businesses, etc.) often conduct reverse auctions to secure a business contract with a supplier at the lowest price. In such a scenario, the market-maker makes the reverse auction participants aware of a business opportunity and sets an initial or maximum price that the market-maker is willing to pay to secure that business opportunity. The auction participants then submit bids in an attempt to win the market-maker's business.
[0011] Auctions may be considered English or Dutch depending upon the nature of the starting price set by the market-maker.
[0012] In English reverse auctions, the starting bid is the highest price the market-maker is willing pay for the service, and subsequent bids are lower.
[0013] In Dutch reverse auctions, the starting price set by the market maker is low and subsequent bids are increased until an auction participant agrees to pay the bid price.
[0014] The present invention supports both types of reverse auctions.
SUMMARY OF THE INVENTION
[0015] The present invention enables service providers to create real-time reverse auctions by using advanced data collection, filtering and disseminating algorithms. In addition, market-makers can provide value-added services, such as real-time traffic conditions and route planning, to their local affiliates. Such a system can allow market-makers to economically service customer requests by leveraging the real-time conditions and circumstances of their vast network of local service affiliates.
[0016] Open competition will drive down prices for these services and increase revenues for the market-makers who will be able to provide service in response to customer requests at the best prices available. The system will also benefit local service affiliates by notifying them and allowing them to compete for a broader number of service requests than they would otherwise be aware of.
[0017] The system can also provide for a feedback mechanism where the customer provides feedback regarding the service provided. The feedback mechanism will encourage superior customer service since affiliates will want to ensure that they are considered for more jobs. That is, low customer evaluations in the feedback will result in the service provider not being considered for future opportunities.
[0018] By using advanced algorithms to leverage the time-value of information and by applying sophisticated communication and filtering techniques, the reverse auction platform presented by this invention benefits both market-makers and local affiliates alike by enabling a higher level of dynamism and efficiency in matching service requests with service providers.
[0019] The invention will be better understood when the following description is read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
[0020] FIG. 1 is flow diagram of an embodiment of the invention.
DETAILED DESCRIPTION
[0021] An illustrative example of a system and method of the invention will now be described in connection with an automobile break down scenario. It will be understood by those skilled in the art that the invention has many other applications, in addition to an automotive break down application, where the invention is equally applicable and advantageous.
[0022] This invention concerns systems, methods and algorithms that enable market-makers to create real-time, secure, information-rich reverse auctions. While the invention generalizes to any type of service requests where a reverse auction may be appropriate, the invention will be described using a representative example of a car-towing service as illustrative of the invention throughout the following description, it being understood that the invention is not so limited.
[0023] In accordance with the present example, consider the market-maker to be a national car-towing company that uses local service affiliates to fill customer requests. The local service affiliates then compete with each other to service those customer requests. The competitive factors between local affiliates may include a number of variables, some which include price, reliability, time to service the request, favorable customer feedback, and the like.
[0024] The invention comprises several steps that enable market-makers to successfully and reliably offer real-time reverse auctions. These steps are outlined below:
[0025] 1) Geographic localization and confirmation of customer's location.
[0026] 2) Categorizing and indexing of customer requirements.
[0027] 3) Identification of feasible local service affiliates.
[0028] 4) Filtering of feasible service affiliates to candidate service affiliates.
[0029] 5) Notification to candidate service affiliates.
[0030] 6) Display of relevant customer request information to candidate service affiliates:
a. Initial price for bids. b. Distance to customer and distance to desired customer final destination. c. Real-time traffic and weather conditions for both the customer's location as well as the customer's desired (drop off point) final destination. d. Routing information from the local service affiliate's location to the customer, from the customer's location to the customer's final destination, and from the customer final destination back to the service affiliate's location. e. Applicable history and profile information of the customer. f. Make and model of the car, as well as possible items and tools to carry to the location.
[0037] 7) Auction execution software.
a. Mechanisms that allow the candidate service affiliates to bid. b. Real-time data management methods that can reliably relay bid prices from auction participants to the auction platform.
[0040] 8) Settlement software that finalizes a contract between the winning bidder and the market-maker.
[0041] 9) Billing mechanism that allows the winning candidate affiliate and the market-maker to be paid.
[0042] 10) Feedback mechanisms to allow both the customer and the service affiliate to submit feedback about the process that will be stored in a database and consulted for future service opportunities.
[0043] In the following description a system and process by which the market-maker can enable such a reverse auction is described. We will consider a representative example of a car that has broken down alongside the road and needs a tow.
[0044] Step 1
[0045] The car owner/driver calls a national car-towing company (or a national car-towing company is contacted via a roadside assistance provider such as AAA, etc.) that service is required 100 . In some instances the car can directly contact a roadside assistance provider when the car is provided with equipment for detecting a breakdown of the car.
[0046] The first step in enabling the reverse auction is to determine the location of the customer 102 . While the caller can specify the location, it is not uncommon for travelers to be lost or to be unable to provide specific location information.
[0047] The software platform will, in such cases, have the capability of integrating with other telecommunications platforms to confirm the caller's location. This may occur via any known method of determining mobile location such as cellular positioning (for cell phone calls), and/or reverse phone number addressing (for landline phone calls), and/or the use of a global positioning system (GPS) in the vehicle or phone. The outcome of this process will be an address, cross-street or mile-marker identification that can be used to find the customer. Alternatively, if longitude and latitude information (geographical co-ordinates) is determined, the co-ordinates can be converted to a map location.
[0048] Step 2
[0049] The caller provides details about the situation including make and model of car, symptoms the car displayed before breaking down, preferences for towing destinations (dealerships, home, work, etc.), time-frame commitments, and the like 104 .
[0050] This information is captured and indexed into a networked software platform. Indexing the information in a common format, such as XML or RDF, allows a standard method for the information to be represented, queried and managed.
[0051] If this customer is already known to the system, the software platform can supplement the information with other information captured in the customer profile.
[0052] Step 3
[0053] Once a customer's location and service parameters have been captured and indexed, the market-maker can begin to identify local service affiliates that are capable of servicing the request 106 . The identification problem can be formulated as a constrained optimization problem where a feasibility region can be identified.
[0054] The software, once configured and customized according to the policies of the market-maker, will be able to construct the feasibility region over the space of all possible local service affiliates 108 . Those affiliates that reside within the feasibility region will be considered and those that reside outside the region will not be considered.
[0055] As an initial example, the feasibility region may be very simple. For example, the system may identify those local affiliates who are within a certain geographic range of the customer's present location, e.g., 30 miles.
[0056] As another example, if a car breaks down in New York City and the driver needs to be towed to her home in Philadelphia, the market-maker may choose to alert service providers in both the New York City and the Philadelphia areas.
[0057] In another embodiment of the invention use real-time traffic conditions and route planning algorithms are used to determine the mean time to reach the customer. In such cases the closest local affiliate may not be the affiliate that can reach the customer in the shortest amount of time. As used herein, the term “real-time” will be understood to include so-called “near real-time” information.
[0058] By incorporating real-time traffic conditions and routing algorithms, the market-maker can immediately eliminate local affiliates who may not be able to meet the customer's time constraints.
[0059] Furthermore, using live or real-time or near real-time data allows the system to dynamically adapt to changes in ways that a static system can not adapt. Distance and time to the customer are only example criteria, however, and the market-maker may identify local affiliates on the basis of their affiliation (Toyota dealers, for example) or special facilities or capabilities of a local affiliate.
[0060] The market-maker may decide to cull from the list those local service affiliates with poor recent feedback ratings or a history of billing disputes, etc. The resulting list of local service affiliates capable of servicing the customer request and satisfying any market-maker imposed policies then become the set of candidate service affiliates who will be notified of the service opportunity and will be given the opportunity to participate in the auction.
[0061] Step 4
[0062] The candidate service affiliates once identified must then be notified 110 . The present invention allows candidates to be notified via multiple mechanisms including via a web-based application as well as via wireless communication through SMS.
[0063] The notification will alert staff at candidate service affiliates that there is an active auction underway. The web application will then display auction details such as current price and information relevant to the customer request, including current customer location, desired drop-off point (final destination) as well as mileage and routing information 112 .
[0064] The web-application can also display current traffic information to give the decision makers at the candidate service affiliates an idea of transit times, etc. Also, the application may display a recommended list of items and tools to bring to the scene that may help in diagnosing and solving the customer's car problems.
[0065] The platform is also capable of delivering notifications to candidate service affiliates via SMS. This allows those candidate affiliates who may be away from a computer or out in the field to still participate in the auction process. By delivering notifications only via the web, many candidate affiliates may miss out on revenue generating opportunities.
[0066] SMS notifications may contain less information than that contained in the web-based notifications. However the SMS notifications will contain links to a website that allow candidate service affiliate staff to access the necessary information to review the auction details. This website will be properly formatted (WAP, etc) for viewing on a wide array of mobile phones. Also, one embodiment of the invention includes a telephone number in the notification SMS that a candidate service affiliate staff member can dial to hear an integrated voice response menu that describes the opportunity.
[0067] The software may also enable the staff member to place bids and otherwise participate in the auction via a typical cell phone. Still another embodiment would allow the staff member to tell the automated system his current location. The automated system would compute the expected travel time to the scene, using live traffic reports, and send the staff member an SMS with detailed directions. Finally, another embodiment of the invention notifies candidate affiliates through an IVR application delivered to any phone line.
[0068] Step 5
[0069] The platform will next execute the auction process 114 . This entails giving candidates the ability to place bids, to see the current bid and to place new bids. The platform will also be capable of computing the time duration of the auction and displaying this information to the set of bidders. Bids may be placed on the web via the web-portal application, via mobile phone or via an Integrated Voice Response (IVR) system using a traditional landline phone. The platform will coordinate the dynamic auction information and disseminate it to bidders accessing the system via any method, including the above-mentioned methods.
[0070] The platform will enable data consistency and accuracy across these multiple platforms. Bidders will be notified of the remaining time to place a bid and the dollar value of the current winning bid.
[0071] Implementation
[0072] Dutch Reverse Auction
[0073] Implementing Dutch reverse auctions may require different procedures than that of English auctions. Dutch auctions may be concluded by the submission of the first bid. For example, in a Dutch auction the market-maker would announce a set price (often low) to the candidate affiliates, and the first affiliate to respond by accepting the set price will win the business. In this case the auction execution requires reliable and timely delivery of bidding information. Therefore, the platform will ensure that all communications involving bids are delivered with the highest degree of reliability and timeliness.
[0074] Dutch reverse auctions also do not require that auction participants be made aware of other participant's bids. The Dutch reverse auction can be thought of as a yes or no proposition put to each of the candidate service affiliates. The first candidate service affiliate to answer yes (accept the price) wins the business. In this case, the non-winning participants only need to be notified that they did not win the auction.
[0075] One implementation of the invention would close the bidding process once an affiliate accepted a Dutch reverse auction. In this embodiment, when a subsequent affiliate was directed to the bidding web-portal, they would be presented with a notice that bidding was closed. Another embodiment of the invention allows the system to prioritize the candidate service affiliates and determine which subset will be contacted first, and thus have an advantageous bidding position. This capability could be used by the market-maker to tier their local service provider affiliates, extract additional revenue or encourage local affiliate behavior.
[0076] English Reverse Auction
[0077] Implementing English reverse auctions requires more consideration and maintenance of state. In such auctions bidders compete with one another for a predefined period of time or until a pre-defined bid is reached. In these cases, the platform will support the data consistency and state necessary to execute the auction, even over multiple access platforms such as web, wireless and landline.
[0078] Settlements and Billing
[0079] At the conclusion of the auction 116 , the platform will perform auction settlement with the winning bidder 118 . This will include finalizing a service contract that binds the winning affiliate to the terms agreed to in the auction.
[0080] In addition, fulfillment software on the platform will deliver a work order to the winning bidder that displays all the critical information relevant to the customer and the request. The work order may be delivered electronically or via fax. The platform will log these transactions and archive them. With the work order, the winning affiliate is now free to service the customer's request.
[0081] Billing and reconciliation software on the platform will ensure that transactions are billed appropriately and that disputes can be handled. For example, each work order will be logged and identified by the system and will be referenceable from the customer receipt. This will allow easy retrieval of billing documents that can expedite claims.
[0082] Quality Assurance and Control
[0083] The platform also allows both the customer as well as the winning affiliate to submit feedback on the transaction. For example, a customer may complain of discourteous and/or dangerous drivers.
[0084] This information will be logged by the system and used in making future candidate selections and auction decisions. As another example, the winning affiliate may comment that the customer misrepresented their situation, demanded unreasonable service or was otherwise difficult. This information, too, will be stored by the system and can be used in future service decisions.
[0085] Customers will be able to access the system via a web-link presented on all customer receipts. This will help to grow the community of comments. Furthermore, one embodiment of this invention allows customers who are requesting service to consult a list of rankings and comments of local service affiliates and suggest a preferred affiliate, possible for a premium fee.
[0000] While there has been described and illustrated a system and method for enabling service providers to create real time reverse auctions and several modifications and variations thereof, it will be apparent to those skilled in the art that further modifications and variations are possible without deviating from the teachings and broad principles of the invention which shall be limited solely by the scope of the claims appended hereto.
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A system and method facilitates the matching of service providers based on certain criteria such as, but not limited to, location of the provider in relation to a customer location, customer requests based on the location of the customer, the type of service requested and other possible attributes such as customer profile, customer past behavior and preferences and service price and quality. Service providers create real-time reverse auctions by using advanced data collection, filtering and disseminating algorithms. In addition, market-makers can provide value-added services, such as real-time traffic conditions and route planning, to their local affiliates. Such a scheme can allow market-makers to economically service customer requests by leveraging the real-time conditions and circumstances of their vast network of local service affiliates. Open competition will drive down prices for these services and increase revenues for the market-makers who will be able to service customer requests at the best prices available. This system will also benefit local service affiliates by notifying them and allowing them to compete for a broader number of service requests. A feedback mechanism will also encourage superior customer service since affiliates will want to ensure that they are considered for more jobs.
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This application is a continuation application of U.S. application Ser. No. 09/970,416, filed on Oct. 3, 2001 now U.S. Pat No. 6,450,983.
FIELD OF THE INVENTION
The present invention relates generally to surgical wound protectors, and more particularly to an adjustable surgical wound protector for use in protecting incised cavity walls of various thicknesses from harmful contaminants during surgery.
BACKGROUND OF THE INVENTION
The sides of a wound during surgery are inherently susceptible to bacterial infection if touched by contaminated substances such as diseased body parts and fluids as they pass through the wound. Therefore extreme care must be exercised to insure that the exposed sides of an incision are completely covered by a material impervious to solids and fluids containing bacteria and other contaminants before surgery proceeds.
Various techniques have been used to insulate any incised tissue from exposure. One form of protection for relatively large incisions typically employs soft cotton sponges held against the sides of the wound by metal retractors to minimize contamination as well as to give the surgeon better access into the operating site. Another form of wound protector, particularly suitable for surgery, is disclosed in U.S. Pat. No. 3,347,227 to Harrower. Harrower discloses a surgical incision protector consisting of a pair of flexible rings joined by a thin, tubular-shaped sheet of flexible material. Harrower's rings have sufficient preforming to give a generally oval shape, be resilient and flexible, and so as to be easily flexed for insertion through a wound opening. The thin sheet is preferably made of plastic and must be impermeable to fluids and bacteria, physiologically inert, unaffected by autoclaving or sterilization, free of electrostatic hazard, resistant to melting, non-flammable, and somewhat elastic. Each of Harrower's flexible rings has a substantially circular cross-section. Harrower's incision protector is assembled by securing each end of the tubular sheet of flexible material to a ring, so that each ring is positioned at an end of the thin sheet of tubular material. In use, one ring is squeezed into an oblong shape, inserted through the peritoneum, and allowed to expand to the preformed shape over the inside edge of the wound. The other ring overlaps the outside edge causing the sleeve to stretch into contiguous contact with the entire surface of the sides and inner and outer edges of the wound. To obtain a form-fitting contiguous contact with the sides of the wound, the circumference of both rings in their preformed shape are slightly larger than that of the incision, and the extended length of the sleeve between the rings is slightly greater than that of the wall thickness. To accommodate variations in wound size, Harrower's wound protectors are manufactured in numerous combinations and permutations of both circumference and length.
U.S. Pat. No. 3,347,226 to Harrower describes an adjustable wound protector which reduces, to a degree, the number of sizes required. It requires a number of predetermined lengths similar to U.S. Pat. No. 3,347,227, except the circumference of the wound protector is adjustable, before being installed in the wound, by the rings having telescoping ends, and the side of the sleeve having overlapping lengthwise edges. Any overlapping excess may be cut off. The rings have a maximum adjustable circumference slightly larger than that of the largest incision anticipated so that they are sure to overlap the inner and outer edges of the wound. However, a sleeve length must be selected which will closely conform to the wall thickness at the wound.
U.S. Pat. No. 5,524,644, issued to Crook discloses an incrementally adjustable apparatus for protecting an incised wound from exposure to bacterial and other harmful contaminants. Crook provides a pair of resilient O-rings that are connected to opposite ends of an impermeable pliable sleeve. One of the O-rings is formed to engage the inner edge of the wound with a portion of the sleeve which is capable of being rolled onto the other ring to draw the remaining sleeve portion contiguous with the sides of the wound. Significantly, Crook relies upon flat surfaces on the rolled ring, that form an oblate cross-section, to provide a gripping surface to turn the ring about its annular axis.
SUMMARY OF THE INVENTION
In one preferred embodiment, an O-ring is provided for use in an adjustable surgical wound protector comprising a solid cross-section including a cross-sectional center that is spaced from a central longitudinal axis and a resilient configuration for squeezing into an oblong shape that is insertable into a surgical incision. At least one recess is defined in the O-ring that is selectively sized and shaped to enable a snap-action rolling of the O-ring about the cross-sectional center in predetermined increments. The recess may comprise various cross-sectional shapes, such as, at least one circumferential groove, a plurality of circumferentially positioned recesses, or be shaped such that the O-ring comprises a cruciform cross-section.
In one preferred embodiment of the invention, an O-ring is provided for use in an adjustable surgical wound protector that comprises a circular torus having a solid cross-section including a cross-sectional center that is radially equidistant from a central longitudinal axis. This O-ring also comprises a resilient configuration that is suitable for squeezing into an oblong shape that is insertable into a surgical incision. Advantageously, two recesses are formed in the O-ring that are selectively sized and shaped to enable a snap-action rolling of the O-ring about the cross-sectional center in predetermined increments. The circular cross-section of the O-rings preferably comprises four quadrants, with the material defining two diagonally opposed quadrants being removed, leaving two diagonally opposed recesses. The solid portion of each O-ring defines a first solid quadrant and a diagonally opposed second solid quadrant, with the first solid quadrant including a curved outer surface, a curved annular surface, and a sinusoidal surface, and the second solid quadrant also including a curved outer surface, a curved annular surface, and a sinusoidal surface. The first and second curved annular surfaces are preferably disposed at substantially the same radial distance from the central longitudinal axis, and are vertically oriented so as to be substantially parallel with the central longitudinal axis. The sinusoidal surfaces extend transversely relative to the central longitudinal axis.
An improved adjustable surgical wound protector is also provided that comprises an elongate open-ended tube formed of a pliable material that is impervious to solid and fluid contaminants for inserting lengthwise into a surgical incision. Two O-rings are one each secured around the open ends of the tube. The O-rings have a resilient configuration for overlapping the inner edge of the wound and for squeezing into an oblong shape that is insertable with a lengthwise portion of the sleeve adjacent to one of the O-rings in the surgical incision. Advantageously, at least one of the O-rings comprises at least one recess for enabling selected snap-action rolling of the at least one O-ring for rolling the remaining lengthwise portion of the sleeve on itself about the O-ring to shorten the sleeve in predetermined increments and to resist subsequent lengthening, whereby the sleeve length can be adjusted before or after placement in the wound.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features and advantages of the present invention will be more fully disclosed in, or rendered obvious by, the following detailed description of the preferred embodiment of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts and further wherein:
FIG. 1 is a perspective, partially broken away view of an incrementally adjustable surgical wound protector formed in accordance with the present invention;
FIG. 2 is a perspective view of an O-ring formed in accordance with a preferred embodiment of the present invention;
FIG. 3 is a cross-sectional view of the O-ring shown in FIG. 2, as taken along lines 3 — 3 in FIG. 2, and including a portion of the interior side surface of the O-ring;
FIG. 4 is a side elevational view of the O-ring shown in FIG. 2;
FIG. 5 is a broken away, cross-sectional view of the incrementally adjustable surgical wound protector shown in FIG. 1, as taken along lines 5 — 5 in FIG. 1, illustrating the interconnection between the O-ring and sleeve;
FIGS. 6-9 illustrate in sequence, the operation of the incrementally adjustable surgical wound protector shown in FIG. 1;
FIG. 10 is a perspective view of one alternative embodiment of O-ring;
FIG. 11 is a side elevational view of the O-ring shown in FIG. 10;
FIG. 12 is a cross-sectional view, taken along line 12 — 12 in FIG. 11;
FIG. 12A is a cross-sectional view similar to that shown in FIG. 12, but illustrating an alternative cruciform cross-section having radiused end surfaces;
FIG. 13 is a perspective view of another embodiment of O-ring;
FIG. 14 is a side elevational view of the O-ring shown in FIG. 13;
FIG. 15 is a cross-sectional view, as taken along lines 15 — 15 in FIG. 14, showing an alternative cruciform cross-section;
FIG. 15A is a cross-sectional view similar to that shown in FIG. 15, but illustrating an alternative cruciform cross-section having radiused end surfaces;
FIG. 16 is a perspective view of yet another alternative embodiment of O-ring;
FIG. 17 is a side elevational view of the O-ring shown in FIG. 16;
FIG. 18 is a cross-sectional view, as taken along line 18 — 18 in FIG. 17, showing an embodiment of recess used in connection with the present invention;
FIG. 19 is a perspective view of a further alternative embodiment of O-ring;
FIG. 20 is a side elevational view of the O-ring shown in FIG. 19;
FIG. 21 is a cross-sectional view, as taken along the line 21 — 21 in FIG. 20;
FIG. 22 is a perspective view of yet a further alternative embodiment of O-ring;
FIG. 23 is a front elevational view of the O-ring shown in FIG. 22;
FIG. 24 is a cross-sectional view, as taken along lines 24 — 24 in FIG. 23;
FIG. 25 is a perspective view of yet a further alternative embodiment of O-ring;
FIG. 26 is a front elevational view of the O-ring shown in FIG. 25;
FIG. 27 is a cross-sectional view, as taken along lines 27 — 27 in FIG. 26;
FIG. 28 is a perspective view of yet a further alternative embodiment of O-ring;
FIG. 29 is a front elevational view of the O-ring shown in FIG. 28;
FIG. 30 is a cross-sectional view, as taken along lines 30 — 30 in FIG. 29;
FIG. 31 is a perspective view of yet a further alternative embodiment of O-ring;
FIG. 32 is a front elevational view of the O-ring shown in FIG. 31;
FIG. 33 is a cross-sectional view, as taken along lines 33 — 33 in FIG. 32
FIG. 34 is a perspective view of yet a further alternative embodiment of O-ring;
FIG. 35 is a front elevational view of the O-ring shown in FIG. 34;
FIG. 36 is a cross-sectional view, as taken along lines 36 — 36 in FIG. 35;
FIG. 37 is a perspective view of yet a further alternative embodiment of O-ring;
FIG. 38 is a front elevational view of the O-ring shown in FIG. 37;
FIG. 39 is a cross-sectional view, as taken along lines 39 — 39 in FIG. 38;
FIG. 40 is a perspective view of yet a further alternative embodiment of O-ring;
FIG. 41 is a front elevational view of the O-ring shown in FIG. 40;
FIG. 42 is a cross-sectional view, as taken along lines 42 — 42 in FIG. 41;
FIG. 43 is a perspective view of yet a further alternative embodiment of O-ring;
FIG. 44 is a front elevational view of the O-ring shown in FIG. 43;
FIG. 45 is a cross-sectional view, as taken along lines 45 — 45 in FIG. 44;
FIG. 46 is a perspective view of yet a further alternative embodiment of O-ring;
FIG. 47 is a front elevational view of the O-ring shown in FIG. 46;
FIG. 48 is a cross-sectional view, as taken along lines 48 — 48 in FIG. 47;
FIG. 49 is a perspective view of yet a further alternative embodiment of O-ring;
FIG. 50 is a front elevational view of the O-ring shown in FIG. 49;
FIG. 51 is a cross-sectional view, as taken along lines 51 — 51 in FIG. 50;
FIG. 52 is a perspective view of yet a further alternative embodiment of O-ring;
FIG. 53 is a front elevational view of the O-ring shown in FIG. 52;
FIG. 54 is a cross-sectional view, as taken along lines 54 — 54 in FIG. 53;
FIG. 55 is a perspective view of yet a further alternative embodiment of O-ring;
FIG. 56 is a front elevational view of the O-ring shown in FIG. 55;
FIG. 57 is a cross-sectional view, as taken along lines 57 — 57 in FIG. 56;
FIG. 58 is a perspective view of yet a further alternative embodiment of O-ring;
FIG. 59 is a front elevational view of the O-ring shown in FIG. 58;
FIG. 60 is a cross-sectional view, as taken along lines 60 — 60 in FIG. 59;
FIG. 61 is a perspective view of yet a further alternative embodiment of O-ring;
FIG. 62 is a front elevational view of the O-ring shown in FIG. 61;
FIG. 63 is a cross-sectional view, as taken along lines 63 — 63 in FIG. 62;
FIG. 64 is a perspective view of yet a further alternative embodiment of O-ring;
FIG. 65 is a front elevational view of the O-ring shown in FIG. 64;
FIG. 66 is a cross-sectional view, as taken along lines 66 — 66 in FIG. 65;
FIG. 67 is a perspective view of yet a further alternative embodiment of O-ring;
FIG. 68 is a front elevational view of the O-ring shown in FIG. 67; and
FIG. 69 is a cross-sectional view, as taken along lines 69 — 69 in FIG. 68 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
This description of preferred embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description of this invention. In the description, relative terms such as “horizontal,” “vertical,” “up,” “down,” “top” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing figure under discussion. These relative terms are for convenience of description and normally are not intended to require a particular orientation. Terms including “inwardly” versus “outwardly,” “longitudinal” versus “lateral” and the like are to be interpreted relative to one another or relative to an axis of elongation, or an axis or center of rotation, as appropriate. Terms concerning attachments, coupling and the like, such as “connected” and “interconnected,” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. The term “operatively connected” is such an attachment, coupling or connection that allows the pertinent structures to operate as intended by virtue of that relationship. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function, including not only structural equivalents but also equivalent structures.
Referring to FIG. 1, an incrementally adjustable surgical wound protector 5 comprises a thin flexible sleeve 8 positioned between a first O-ring 10 and a second O-ring 12 . Sleeve 8 comprises a tube having a uniform circumference along its length, an upper end edge 16 , and a lower end edge 18 . Upper end edge 16 of sleeve 8 is fastened or bonded to a surface portion of first O-ring by sealing, e.g., thermally, ultrasonically or, with proper pretreatment, adhesives, but without (i) the portion of sleeve 8 adjacent to upper end edge 16 being wrapped around the circumference of first O-ring 10 , or (ii) overlapped upon itself. Likewise, lower end edge 18 of sleeve 8 is fastened or bonded to a surface portion of O-ring 12 by sealing, e.g., thermally, ultrasonically or, with proper pretreatment, adhesives, but without (i) the portion of sleeve 8 adjacent to lower end edge 18 being wrapped around the circumference of O-ring 12 , or (ii) overlapped upon itself (FIGS. 5 - 9 ). Sleeve 8 may also be attached to O-rings 10 , 12 by adhesive, but with less than satisfactory results.
Sleeve 8 is preferably formed from a material that is impervious to solids and/or fluids containing bacteria and other harmful contaminants, e.g., a polymer or elastomeric material of the type known in the art. The materials and dimensions of wound protector 5 are selected to ensure stability of the wound protector when installed. A preferred polymer material suitable for sleeve 8 is a heat-sealable 2-mil aromatic polyether polyurethane film, such as the PT6100 series manufactured by Deerfield Urethane, Inc., under the tradename DUROFLEX, that may be produced in seamless tubular form or by a flat sheet in a cylindrical form with the meeting margins along the side overlapped and sealed. Other materials that may be used with good effect include, polyolefins and other like plastomers and elastomers that are suitable for use in medical applications. A nominal sleeve length suitable for surgery is typically from about 100 to about 200 mm. Sleeve diameters will vary according to the length of the surgical incision.
First O-ring 10 and second O-ring 12 each are formed so as to engage the inner edge of a surgical incision, with a portion of sleeve 8 above the incision and capable of being incrementally rolled toward the other O-ring to draw the remaining portion of sleeve 8 contiguous with the sides of the incision. O-rings 10 and 12 are preferably formed from an elastomeric medical grade material of sufficient hardness to retain O-rings 10 and 12 expanded in place around the inner and outer edges of the surgical incision. The material must be compliant enough to allow O-ring 10 or 12 to be turned by the fingers over 180 degrees about its center. For this purpose, urethane is a preferred elastomeric material. O-rings 10 , 12 may be formed from other resilient materials, such as medical grade, polyvinylchloride, silicon, natural rubber, or other elastomeric or rubber-like materials, with good effect.
Referring to FIGS. 1-5, O-rings 10 , 12 preferably comprise a circular torus, i.e., a solid formed by the rotation of a circle about an axis that lies in the plane of the circle, but without cutting the circle. O-rings 10 , 12 are formed from a solid, initially circular cross-section torus having a cross-sectional center 20 that is radially equidistant from a central longitudinal axis 24 of the O-ring. The circular cross-section of each O-ring 10 , 12 may be divided into four quadrants (FIGS. 3, and 5 - 9 ). Material defining two diagonally opposed quadrants is removed, leaving two diagonally opposed recesses 26 and 28 (best shown in FIG. 3 ).
The solid portion of O-rings 10 , 12 that remains defines a first solid quadrant 30 and a diagonally opposed, second solid quadrant 33 . First solid quadrant 30 includes a curved outer surface 36 , a curved annular surface 38 , and a sinusoidal surface 40 . Second solid quadrant 33 includes a curved outer surface 46 , a curved annular surface 48 , and a sinusoidal surface 50 . Curved annular surfaces 38 , 48 are at substantially the same radial distance from central longitudinal axis 24 , and are vertically oriented so as to be substantially parallel and substantially coaxial with central longitudinal axis 24 . Sinusoidal surfaces 40 , 50 extend transversely relative to the central longitudinal axis 24 of O-rings 10 , 12 (FIGS. 2 and 3 ).
Of course, it will be understood that the term “O-ring” is not limited to circular structures or classic toroidal shapes, but also includes structures that are not circular, e.g., rectilinear, oval/elliptical, hexagonal, octagonal, etc., as long as such rings comprise a resilient configuration capable of being squeezed into an oblong shape that is suitable for insertion into a surgical incision.
By way of example, a urethane O-ring 10 , 12 for use with a sleeve having a diameter of about 109 mm, has a diameter of about 7.9 mm, with a radial depth of diagonally opposed recesses 26 and 28 of approximately 4.0 mm. Of course, the sizes of the O-rings and sleeves will vary according to incision size and peritoneum wall thickness. The personal preference of the surgeon will also affect the choice of both O-ring and sleeve size for a particular surgical procedure. Each end of sleeve 8 is sealingly fastened or bonded around an O-ring 10 , 12 , e.g., to a curved outer surface 46 , such that when the sleeve is fully extended, O-rings 10 , 12 are positioned in spaced-apart relation to one another (FIGS. 1 and 5 ).
The cross-sectional shape of O-rings 10 , 12 provides stability in a plane perpendicular to central longitudinal axis 24 , and provides an over-center “snap-action” or “snap-roll” when O-ring 10 , 12 is rolled about itself and sleeve 8 , thereby providing incremental shortening in predetermined increments and resistance to lengthening after shortening. More particularly, by strategically removing portions of O-rings 10 , 12 so as to form recesses 26 , 28 , the rate of twist necessary to create the over-center “snap-action” can be gauged and set. Typically, about 33% to about 70% of the mass of the O-ring must be either removed or redistributed in order to obtain a “snap-action” that is suitable for hand twisting. Thus numerous O-rings (FIGS. 12 - 39 ), having differing amounts, locations, and shapes of material removed from their cross-section may be used in connection with the present invention.
For example, and referring to FIGS. 10-15, rings 10 , 12 may comprise a cruciform cross-sectional profile. In this configuration, the cruciform shape of O-rings 10 , 12 provide stability in a plane perpendicular to central longitudinal axis 24 and also provide the over-center, “snap-action” when rolled about themselves and sleeve 8 . The embodiment disclosed in FIGS. 10-12 include a cruciform cross-section having flat surfaces 60 and 62 . While FIGS. 13-15 show a similar O-ring 10 , 12 having radiused surfaces 65 and 67 . Of course, the end surfaces of the cruciform cross-section O-ring 10 , 12 may also have radiused end surfaces, as shown in FIGS. 12A and 15A.
Referring to FIGS. 16-33, O-rings 10 , 12 may also include a plurality of recesses defined into a portion of the ring. More particularly, a plurality of recesses 70 are defined radially inwardly into O-ring 10 , 12 , i.e., toward cross-sectional center 20 , from diametrically opposed positions along the circumference of the O-ring. In this way, recesses 70 extend into O-ring 10 , 12 from each side in an alternating pattern. FIGS. 16-18 illustrate a rectilinearly shaped plurality of alternating recesses 70 , while FIGS. 19-21 illustrate a plurality of round recesses 72 and FIGS. 22-24 illustrate a plurality of round, shallow recesses 72 a disposed on both sides of O-ring 10 , 12 .
Referring to FIGS. 25-33, a sinusoidally defined recess 72 b may be employed with the present invention. FIGS. 25-27 illustrate such a sinusoidal recess 72 b disposed on an inner circumferential surface of O-ring 10 , 12 , while FIGS. 28-30 illustrate such a sinusoidal recess 72 b disposed on an outer circumferential surface of O-ring 10 , 12 . FIGS. 31-33 illustrate a pair of sinusoidal recesses 72 b positioned in diametrically opposed relation to one another on O-ring 10 , 12 . In each of the foregoing cases, the removal of material from O-ring 10 , 12 to define recesses 70 , 72 , or 72 b provides stability in a plane perpendicular to central longitudinal axis 24 , and provides an over-center “snap-action” when the O-ring is rolled about itself and sleeve 8 .
Referring to FIGS. 34-42, O-rings 10 , 12 may also have a continuous recess formed in diametrically opposed portions of O-ring 10 , 12 . More particularly, a top recess 78 and a bottom recess 80 may be formed in O-ring 10 , 12 so as to yield “a bow-tie” cross-sectional profile to O-ring 10 , 12 (FIGS. 34-36) or may be formed so as to be shallow (FIGS. 37 - 39 ). The removal of material from O-ring 10 , 12 from diametrically opposed portions in a continuous, or annular fashion, provides stability in a plane perpendicular to central longitudinal axis 24 , and provides an over-center “snap-action” when the O-ring is rolled about itself and sleeve 8 . A plurality of reinforcing ribs 82 may be formed within top recess 78 and/or bottom recess 80 so as to ease manufacture (FIGS. 40 - 42 ).
Referring to FIGS. 43-57, O-rings 10 , 12 may also be formed so as to have convex top and bottom walls 86 , 88 , and substantially flat inner and outer, annular side walls 90 , 92 (FIGS. 43-45) or convex top and bottom walls 86 , 88 and convex inner and outer, annular side walls 94 , 96 (FIGS. 46 - 48 ). The reduction of material from O-ring 10 , 12 coupled with the curvature of either the top and bottom walls 86 , 88 or the annular inner and outer side walls 94 , 96 provides stability in a plane perpendicular to central longitudinal axis 24 , and provides an over-center “snap-action” when the O-ring is rolled about itself and sleeve 8 .
Additionally, O-ring 10 , 12 may also be formed so as to have nonparallel top and bottom walls 100 , 102 , and convex inner and outer, annular side walls 104 , 106 (FIGS. 49 - 51 ). Alternatively, O-ring 10 , 12 may also be formed so as to have nonparallel, convex top and bottom walls 108 , 110 , and convex inner and outer, annular side walls 112 , 114 (FIGS. 52 - 54 ). Also, an additional annular flat 116 may be included at the transition between convex inner and outer, annular side walls 112 , 114 and convex top and bottom walls 108 , 110 (FIGS. 55 - 57 ).
Referring to FIG. 58-, O-rings 10 , 12 may also include a plurality of through-holes 120 defined radially through O-ring 10 , 12 , i.e., through cross-sectional center 20 , from diametrically opposed positions along the circumference of the O-ring. FIGS. 58-63 illustrate a plurality of rectilinearly shaped through-holes 120 , and double through-holes 122 , respectively, while FIGS. 64-66 illustrate a plurality of round through-holes 124 . In each case, the removal of material from O-ring 10 , 12 to define through-holes 120 , 122 , or 124 provides stability in a plane perpendicular to central longitudinal axis 24 , and provides an over-center “snap-action” when the O-ring is rolled about itself and sleeve 8 .
Referring to FIGS. 67-69, in some instances, O-rings 10 , 12 may have additional material added to their circumference so as to form bulbous protrusions 128 over their outer surface, so as to redistribute the mass of the O-ring 10 , 12 . This redistribution of mass and concomitant change in the moment of inertia of O-ring 10 , 12 also provides stability in a plane perpendicular to central longitudinal axis 24 , and provides an over-center “snap-action” when the O-ring is rolled about itself and sleeve 8 .
Referring again to FIGS. 6-9, when adjustable surgical wound protector 5 is to be used in an abdominal surgical procedure, the abdomen 55 is routinely prepared with antiseptics; the site for the incision is traced on abdomen 55 and covered with a surgical drape; and a muscle-split is made at the site through the peritoneum. One O-ring (identified by reference numeral 12 in FIGS. 6-9) is squeezed lengthwise and inserted into the surgical incision and through the peritoneum, where it is released and returns to its original circular shape. In this position, O-ring 12 is placed within the body cavity and O-ring 10 is positioned outside of the body cavity, with sleeve 8 extending through the body cavity. It will be understood that O-rings 10 , 12 are completely interchangeable. Outer O-ring 10 is then gripped by the thumb and fingers and turned outwardly, in opposite directions, so as to roll sleeve 8 incrementally, i.e., so as to create repeated over-center “snap-rolls” of the O-ring. As a consequence, sleeve 8 is reeled onto outer O-ring 10 until outer O-ring 10 abuts the outer surface of abdomen 55 . The portion of sleeve 8 that is in the incision, and between O-rings 10 , 12 is drawn into contiguous contact with the sides of the incision so as to provide a self-retaining protective barrier during surgery which is impervious to contaminating solids and fluids.
ADVANTAGES OF THE INVENTION
Numerous advantages are obtained by employing the present invention.
The present invention provides a relatively low cost surgical wound protector of simplified and selectively adjustable design which can be easily installed in a wound and adjusted in place to form fit a wide range of cavity wall thicknesses for protection against harmful contaminants.
Another advantage of the invention is the provision of an adjustable wound protector in which relatively few sizes are needed to form fit a wide range of incision sizes and cavity wall thicknesses.
Still another advantage of the invention is the provision of a surgical wound protector which can be adjusted after being inserted in a wound to obtain contiguous contact with the sides of the cavity wall.
A still further advantage of the invention is the provision of a single, easily manufactured O-ring design that provides for a “snap=action” when rolled in itself so as to reel a sleeve onto the O-ring after being inserted in an incision for securing the sleeve in contiguous contact with the sides of the incision.
It is to be understood that the present invention is by no means limited only to the particular constructions herein disclosed and shown in the drawings, but also comprises any modifications or equivalents within the scope of the claims.
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An O-ring is provided for use in an adjustable surgical wound protector having a solid cross-section including a cross-sectional center that is spaced from a central longitudinal axis and a resilient configuration for squeezing into an oblong shape that is insertable into a surgical incision. At least one recess is defined in the O-ring that is selectively sized and shaped to enable a snap-action rolling of the O-ring about the cross-sectional center in predetermined increments. The recess may comprise various cross-sectional shapes, such as, at least one circumferential groove, a plurality of circumferentially positioned recesses, or be shaped such that the O-ring comprises a cruciform cross-section. An improved incrementally adjustable apparatus for protecting an incised wound from exposure to bacterial and other harmful contaminants is also provided including a pair of resilient O-rings connected to opposite ends of an impermeable pliable sleeve. One of the O-rings is formed to engage the inner edge of the wound with a portion of the sleeve above the wound capable of being rolled onto the other ring to draw the remaining sleeve portion contiguous with the sides of the wound.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This Application is a divisional application of U.S. patent application Ser. No. 10/377,916, filed Feb. 28, 2003, which claims benefit of U.S. provisional patent application Ser. No. 60/362,899, filed Mar. 8, 2002 and U.S. provisional patent application Ser. No. 60/362,885, filed Mar. 8, 2002, each of which is incorporated herein in its entirety by this reference thereto.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates generally to the calibration and maintenance of glucose analyzers. More particularly, the invention relates to the use of alternative site glucose determinations to improve algorithm development, calibration, and/or quality control of noninvasive or implantable glucose analyzers.
[0004] 2. Background Information
[0005] Diabetes is a chronic disease that results in improper production and utilization of insulin, a hormone that facilitates glucose uptake into cells. While a precise cause of diabetes is unknown, genetic factors, environmental factors, and obesity appear to play roles. Diabetics have increased risk in three broad categories: cardiovascular heart disease, retinopathy, and neuropathy. Diabetics may have one or more of the following complications: heart disease and stroke, high blood pressure, kidney disease, neuropathy (nerve disease and amputations), retinopathy, diabetic ketoacidosis, skin conditions, gum disease, impotence, and fetal complications. Diabetes is a leading cause of death and disability worldwide. Moreover, diabetes is merely one among a group of disorders of glucose metabolism that also includes impaired glucose tolerance, and hyperinsulinemia, or hypoglycemia.
[0000] DIABETES PREVALENCE AND TRENDS
[0006] Diabetes is an ever more common disease. The World Health Organization (WHO) estimates that diabetes currently afflicts 154 million people worldwide. There are 54 million people with diabetes living in developed countries. The WHO estimates that the number of people with diabetes will grow to 300 million by the year 2025. In the United States, 15.7 million people or 5.9 per cent of the population are estimated to have diabetes. Within the United States, the prevalence of adults diagnosed with diabetes increased by six percent in 1999 and rose by 33 percent between 1990 and 1998. This corresponds to approximately eight hundred thousand new cases every year in America. The estimated total cost to the United States economy alone exceeds $90 billion per year. Diabetes Statistics, National Institutes of Health, Publication No. 98-3926, Bethesda, Md. (November 1997).
[0007] Long-term clinical studies show that the onset of complications can be significantly reduced through proper control of blood glucose levels. The Diabetes Control and Complications Trial Research Group, The effect of intensive treatment of diabetes on the development and progression of long - term complications in insulin - dependent diabetes mellitus, N Eng J of Med, 329:977-86 (1993); U.K. Prospective Diabetes Study (UKPDS) Group, Intensive blood - glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes, Lancet, 352:837-853 (1998); and Y. Ohkubo, H. Kishikawa, E. Araki, T. Miyata, S. Isami, S. Motoyoshi, Y. Kojima, N. Furuyoshi, M. Shichizi, Intensive insulin therapy prevents the progression of diabetic microvascular complications in Japanese patients with non - insulin - dependent diabetes mellitus: a randomized prospective 6- year study, Diabetes Res Clin Pract, 28:103-117 (1995).
[0008] A vital element of diabetes management is the self-monitoring of blood glucose levels by diabetics in the home environment. However, current monitoring techniques discourage regular use due to the inconvenient and painful nature of drawing blood through the skin prior to analysis. The Diabetes Control and Complication Trial Research Group, supra. As a result, noninvasive measurement of glucose has been identified as a beneficial development for the management of diabetes. Implantable glucose analyzers eventually coupled to an insulin delivery system providing an artificial pancreas are also being pursued.
[0000] GLUCOSE MEASUREMENT HISTORY, APPROACHES, AND TECHNOLOGIES
[0009] Diabetes treatment has progressed through several stages. The combined development of insulin therapy and in-home glucose determination led to a radical improvement in the lives of diabetics. Home glucose determination has also progressed through its own succession of stages. Urine tests for glucose have given way to the invasive fingerstick glucose determinations that are more accurate but somewhat painful, also presenting a possible biohazard. The development of alternative site glucose determinations has somewhat mitigated the pain aspects, but may have introduced a new difficulty as a result of temporal and spatial differences in glucose between the well perfused fingertip and the less well perfused alternative sites. Additionally, the biohazard issue remains. Current research is focusing on the development of noninvasive technologies that will totally eliminate the pain associated with glucose determination and fluid biohazard issues. Finally, considerable progress has been made in implantable or full-loop systems incorporating both glucose determination and insulin delivery that will result in the realization of an artificial pancreas. Blood glucose determination may currently be categorized into four major types:
traditional invasive; alternative invasive; noninvasive; and implantable.
[0014] Due to the wide use of these modes of measurement and somewhat loose utilization of terminology in the literature, a detailed summary of the terminology for each mode of measurement is provided here in order to clarify usage of the terms herein.
[0015] In the medical field, the term ‘invasive’ is customarily applied to surgical methods and procedures, generally involving at least some trauma or injury to the tissue, such as cutting, in order to achieve their object. However, in the glucose determination field, the term ‘invasive’ is defined relative to noninvasive. ‘Noninvasive’ clearly describes methods, invariably signal-based, in which no biological sample or fluid is taken from the body in order to perform a glucose measurement. ‘Invasive’ then means that a biological sample is collected from the body. Invasive glucose determinations may then be further broken into two separate groups. The first is a ‘traditional invasive’ method in which a blood sample is collected from the body from an artery, vein, or capillary bed in the fingertips or toes. The second is an ‘alternative invasive’ method in which a sample of blood, interstitial fluid, or biological fluid is drawn from a region other than an artery, vein, or capillary bed in the fingertips or toes.
[0016] 1. Traditional Invasive Glucose Determination
[0017] There are three major categories of traditional (classic) invasive glucose determinations. The first two utilize blood drawn with a needle from an artery or vein, respectively. The third consists of capillary blood obtained via lancet from the fingertip or toes. Over the past two decades, this has become the most common method for self-monitoring of blood glucose.
[0018] Common technologies are utilized to analyze the blood collected by venous or arterial draw and finger stick approaches. Glucose analysis includes techniques such as colorimetric and enzymatic glucose analysis. The most common enzymatic based glucose analyzers utilize glucose oxidase, which catalyzes the reaction of glucose with oxygen to form gluconolactone and hydrogen peroxide as shown by equation 1, infra. Glucose determination includes techniques based upon depletion of oxygen in the sample either through the changes in sample pH, or through the formation of hydrogen peroxide. A number of colorimetric and electro-enzymatic techniques further utilize the reaction products as a starting reagent. For example, hydrogen peroxide reacts in the presence of platinum to form the hydrogen ion, oxygen, and current; any of which may be utilized indirectly to determine the glucose concentration, as in equation 2.
glucose+O 2 →gluconolactone+H 2 O 2 (1)
H 2 O 2 →2H + +O 2 +2e − (2)
It is noted that a number of alternative site methodologies such as the THERASENSE FREESTYLE (THERASENSE, INC., Alameda Calif.) collect blood samples from regions other than the fingertip or toes. These technologies are not herein referred to as traditional invasive glucose meters unless the sample is drawn from the fingertip or toes despite having similar chemical analyses such as the colorimetric or enzymatic analysis described above. However, the same device utilized to collect blood via lancet from sample sites consisting of the fingertip or toe is a traditional invasive glucose analyzer.
[0019] 2. Alternative Invasive Glucose Determination
[0020] There are several alternative invasive methods of determining glucose concentration. A first group of alternative invasive glucose analyzers have a number of similarities to the traditional invasive glucose analyzers. One similarity is that blood samples are acquired with a lancet. Obviously, this form of alternative invasive glucose determination while unsuitable for analysis of venous or arterial blood, may be utilized to collect capillary blood samples. A second similarity is that the blood sample is analyzed using chemical analyses that resemble the colorimetric and enzymatic analyses describe above. The primary difference, however, is that in an alternative invasive glucose determination the blood sample is not collected from the fingertip or toes. For example, according to package labeling, the THERASENSE FREESTYLE meter may be utilized to collect and analyze blood from the forearm. This is an alternative invasive glucose determination due to the location of the lancet draw. In this first group of alternative invasive methods based upon blood draws with a lancet, a primary difference between the alternative invasive and traditional invasive glucose determination is the location of the site of blood acquisition from the body. Additional differences include factors such as the gauge of the lancet, the depth of penetration of the lancet, timing issues, the volume of blood acquired, and environmental factors such as the partial pressure of oxygen, altitude, and temperature. This form of alternative invasive glucose determination includes samples collected from the palmar region, base of thumb, forearm, upper arm, head, earlobe, torso, abdominal region, thigh, calf, and plantar region.
[0021] A second group of alternative invasive glucose analyzers is distinguished by their mode of sample acquisition. This group of glucose analyzers has a common characteristic of acquiring a biological sample from the body or modifying the surface of the skin to gather a sample without utilization of a lancet for subsequent analysis. For example, a laser poration based glucose analyzer utilizes a burst or stream of photons to create a small hole in the skin surface. A sample of substantially interstitial fluid collects in the resulting hole. Subsequent analysis of the sample for glucose constitutes an alternative invasive glucose analysis, whether or not the sample was actually removed from the created hole. A second common characteristic is that a device and algorithm are utilized to determine glucose from the sample. Herein, the term alternative invasive includes techniques that analyze biosamples such as interstitial fluid, whole blood, mixtures of interstitial fluid and whole blood, and selectively sampled interstitial fluid. An example of selectively sampled interstitial fluid is collected fluid in which large or less mobile constituents are not fully represented in the resulting sample. For this second group of alternative invasive glucose analyzers sampling sites include: the hand, fingertips, palmar region, base of thumb, forearm, upper arm, head, earlobe, eye, chest, torso, abdominal region, thigh, calf, foot, plantar region, and toes. A number of methodologies exist for the collection of samples for alternative invasive measurements including:
Laser poration: In these systems, photons of one or more wavelengths are applied to skin creating a small hole in the skin barrier. This allows small volumes of interstitial fluid to become available for a number of sampling techniques; Applied current: In these systems, a small electrical current is applied to the skin allowing interstitial fluid to permeate through the skin; Suction: In these systems, a partial vacuum is applied to a local area on the surface of the skin. Interstitial fluid permeates the skin and is collected.
[0025] In all of the above techniques, the analyzed sample is interstitial fluid. However, some of these same techniques can be applied to the skin in a fashion that draws blood. For example, the laser poration method can result in blood droplets. As described herein, any technique that draws biosamples from the skin without the use of a lancet on the fingertip or toes is referred to as an alternative invasive technique. In addition, it is recognized that the alternative invasive systems each use different sampling approaches that lead to different subsets of the interstitial fluid being collected. For example, large proteins might lag behind in the skin while smaller, more diffusive, elements may be preferentially sampled. This leads to samples being collected with varying analyte and interferent concentrations. Another example is that a mixture of whole blood and interstitial fluid may be collected. These techniques may be utilized in combination. For example the SOFT-TACT, also known as the SOFTSENSE (ABBOT LABORATORIES, INC. Abbot Park Ill.), applies suction to the skin followed by a lancet stick. Despite the differences in sampling, these techniques are referred to as alternative invasive techniques sampling interstitial fluid.
[0026] The literature occasionally refers to the alternative invasive technique as an alternative site glucose determination or as a minimally invasive technique. The minimally invasive nomenclature derives from the method by which the sample is collected. As described herein, the alternative site glucose determinations that draw blood or interstitial fluid, even ¼ microliter, are considered to be alternative invasive glucose determination techniques as defined above. Examples of alternative invasive techniques include the THERASENSE FREESTYLE when not sampling fingertips or toes, the GLUCOWATCH (CYGNUS, INC., Redwood City Calif.) the ONE TOUCH ULTRA (LIFESCAN, INC., Milpitas Calif.), and equivalent technologies.
[0027] A wide range of technologies serve to analyze biosamples collected with alternative invasive techniques. The most common of these technologies are:
Conventional: With some modification, the interstitial fluid samples may be analyzed by most of the technologies utilized to determine glucose concentrations in serum, plasma, or whole blood. These include electrochemical, electroenzymatic, and colorimetric approaches. For example, the enzymatic and colorimetric approaches described above may also be used to determine the glucose concentration in interstitial fluid samples; Spectrophotometric: A number of approaches for determining the glucose concentration in biosamples, have been developed that utilize spectrophotometric technologies. These techniques include: Raman and fluorescence, as well as techniques using light from the ultraviolet through the infrared [ultraviolet (200 to 400 nm), visible (400 to 700 nm), near-IR ( 700 to 2500 nm or 14,286 to 4000 cm −1 ), and infrared (2500 to 14,285 nm or 4000 to 700 cm −1 )].
[0030] As used herein, the term invasive glucose analyzer encompasses both traditional invasive glucose analyzers and alternative invasive glucose analyzers.
[0031] 3. Noninvasive Glucose Determination
[0032] There exist a number of noninvasive approaches for glucose determination. These approaches vary widely, but have at least two common steps. First, an apparatus is utilized to acquire a signal from the body without obtaining a biological sample. Second, an algorithm is utilized to convert this signal into a glucose determination.
[0033] One type of noninvasive glucose determination is based upon spectra. Typically, a noninvasive apparatus utilizes some form of spectroscopy to acquire the signal or spectrum from the body. Utilized spectroscopic techniques include, but are not limited to: Raman and fluorescence, as well as techniques using light from ultraviolet through the infrared [ultraviolet (200 to 400 nm), visible (400 to 700 nm), near-IR (700 to 2500 nm or 14,286 to 4000 cm −1 ), and infrared (2500 to 14,285 nm or 4000 to 700 cm −1 )]. A particular range for noninvasive glucose determination in diffuse reflectance mode is about 1100 to 2500 nm or ranges therein. K. Hazen, Glucose Determination in Biological Matrices Using Near - infrared Spectroscopy, doctoral dissertation, University of Iowa (1995). It is important to note that these techniques are distinct from the traditional invasive and alternative invasive techniques listed above in that the sample interrogated is a portion of the human body in-situ, not a biological sample acquired from the human body.
[0034] Typically, three modes are utilized to collect noninvasive scans: transmittance, transflectance, and/or diffuse reflectance. For example the signal collected, typically consisting of light or a spectrum, may be transmitting through a region of the body such as a fingertip, diffusely reflected, or transflected. Transflected here refers to collection of the signal not at the incident point or area (diffuse reflectance), and not at the opposite side of the sample (transmittance), but rather at some point on the body between the transmitted and diffuse reflectance collection area. For example, transflected light enters the fingertip or forearm in one region and exits in another region typically 0.2 to 5 mm or more away depending on the wavelength utilized. Thus, light that is strongly absorbed by the body such as light near water absorbance maxima at 1450 or 1950 nm would need to be collected after a small radial divergence and light that is less absorbed such as light near water absorbance minima at 1300, 1600, or 2250 nm may be collected at greater radial or transflected distances from the incident photons.
[0035] Noninvasive techniques are not limited to using the fingertip as a measurement site. Alternative sites for taking noninvasive measurements include: a hand, finger, palmar region, base of thumb, forearm, volar aspect of the forearm, dorsal aspect of the forearm, upper arm, head, earlobe, eye, tongue, chest, torso, abdominal region, thigh, calf, foot, plantar region, and toe. It is important to note that noninvasive techniques do not have to be based upon spectroscopy. For example, a bioimpedence meter would be considered a noninvasive device. Within the context of the invention, any device that reads a signal from the body without penetrating the skin and collecting a biological sample is referred to as a noninvasive glucose analyzer. For example, a bioimpedence meter is a noninvasive device.
[0036] An alternative reference method is a reference determination made at a location on the body not including the fingertips and toes. An alternative reference includes both an alternative invasive measurement and an alternative site noninvasive measurement. Hence, an alternative site noninvasive measurement is a noninvasive measurement made at physiological sites excluding the fingertips and toes.
[0037] 4. Implantable Sensor for Glucose Determination
[0038] There exist a number of approaches for implanting a glucose sensor into the body for glucose determination. These implantables may be utilized to collect a sample for further analysis or may acquire a reading or signal from the sample directly or indirectly. Two categories of implantable glucose analyzers exist: short-term and long-term.
[0039] As referred to herein, a device or a collection apparatus is at least a short-term implantable (as opposed to a long-term implantable) if part of the device penetrates the skin for a period of greater than 3 hours and less than one month. For example, a wick placed subcutaneously to collect a sample overnight that is removed and analyzed for glucose content representative of the interstitial fluid glucose concentration is referred to as a short term implantable. Similarly, a biosensor or electrode placed under the skin for a period of greater than three hours that reads a signal indicative of a glucose concentration or level, directly or indirectly is referred to as at least a short-term implantable device. Conversely, devices described above based upon techniques like a lancet, applied current, laser poration, or suction are referred to as either a traditional invasive or alternative invasive technique as they do not fulfill both the three hour and skin penetration parameters. As described herein, long-term implantables are distinguished from short-term implantables by having the criteria that they must both penetrate the skin and be utilized for a period of one month or longer. Long term implantables may remain in the body for many years.
[0040] Implantable glucose analyzers vary widely, but have at least several features in common. First, at least part of the device penetrates the skin. More commonly, the entire device is imbedded into the body. Second, the apparatus is utilized to acquire either a sample of the body or a signal relating directly or indirectly to the glucose concentration within the body. If the implantable device collects a sample, readings or measurements on the sample may be collected after removal from the body. Alternatively, readings or signals may be transmitted from within the body by the device or utilized for such purposes as insulin delivery while in the body. Third, an algorithm is utilized to convert the signals into readings directly or indirectly related to the glucose concentration. An implantable analyzer may read signals from one or more of a variety of body fluids or tissues including but not limited to: arterial blood, venous blood, capillary blood, interstitial fluid, and selectively sampled interstitial fluid. An implantable analyzer may also collect glucose information from skin tissue, cerebral spinal fluid, organ tissue, or through an artery or vein. For example, an implantable glucose analyzer may be placed transcutaneously, in the peritoneal cavity, in an artery, in muscle, or in an organ such as the liver or brain. The implantable glucose sensor may be one component of an artificial pancreas.
[0041] Examples of implantable glucose monitors follow. One example of a CGMS (continuous glucose monitoring system) is a group of glucose monitors based upon open-flow microperfusion. Z. Trajanowski, G. Brunner, L. Schaupp, M. Ellmerer, P. Wach, T. Pieber, P. Kotanko, F. Skrabai, Open - flow microperfusion of subcutaneous adipose tissue for on - line continuous ex vivo measurement of glucose concentration, Diabetes Care, 20:1114-1120 (1997). Another example utilizes implanted sensors that comprise biosensors and amperometric sensors. Z. Trajanowski, P. Wach, R. Gfrerer, Portable device for continuous fractionated blood sampling and continuous ex vivo blood glucose monitoring, Biosensors and Bioelectronics, 11:479-487 (1996). Another example is the MINIMED CGMS (MEDTRONIC, INC., Minneapolis Minn.).
DESCRIPTION OF RELATED TECHNOLOGY
[0000] GLUCOSE CONCENTRATION MEASURED AT FINGERTIP VS. ALTERNATIVE SAMPLING LOCATIONS
[0042] Many authors claim that alternative site glucose concentrations are equivalent to fingerstick glucose determination. A number of examples are summarized below:
[0043] Szuts, et al. conclude that measurable physiological differences in glucose concentration between the arm and fingertip could be determined, but that these differences were found to be clinically insignificant even in those subjects in whom they were measured. E. Szuts, J. Lock, K. Malomo, A. Anagnostopoulos, Althea, Blood glucose concentrations of arm and finger during dynamic glucose conditions, Diabetes Technology & Therapeutics, 4:3-11 (2002).
[0044] Lee, et al. concluded that patients testing two hours postprandial could expect to see small differences between their forearm and fingertip glucose concentrations. D. Lee, S. Weinert, E. Miller, A study of forearm versus finger stick glucose monitoring, Diabetes Technology & Therapeutics, 4:13-23 (2002).
[0045] Bennion, et al. concluded that there is no significant difference in HbA 1 C measurements for patients utilizing alternative site meters off of the fingertip and traditional glucose analyzers on the fingertip. N. Bennion, N. Christensen, G. McGarraugh, Alternate site glucose testing: a crossover design, Diabetes Technology & Therapeutics, 4:25-33 (2002). This is an indirect indication that the forearm and fingertip glucose concentrations are the same, though many additional factors such as pain and frequency of testing will impact the study.
[0046] Peled, et al. concluded that glucose monitoring of blood samples from the forearm is suitable when expecting steady state glycemic conditions and that the palm samples produced a close correlation with fingertip glucose determinations under all glycemic states. N. Peled, D. Wong, S. Gwalani, Comparison of glucose levels in capillary blood samples from a variety of body sites, Diabetes Technology & Therapeutics, 4:35-44 (2002).
[0047] Based upon a study utilizing fast acting insulin injected intravenously, Jungheim, et al. suggested that to avoid risky delays in hyperglycemia and hypoglycemia detection, monitoring at the arm should be limited to situations in which ongoing rapid changes in the blood glucose concentration can be excluded. K. Jungheim, T. Koschinsky, Glucose monitoring at the arm, Diabetes Care, 25:956-960 (2002); and K. Jungheim; T. Koschinsky, Risky delay of hypoglycemia detection by glucose monitoring at the arm, Diabetes Care, 24:1303-1304 (2001). The use of intravenous insulin in this study was criticized as creating physiological extremes that influence the observed differences. G. McGarraugh, Response to Jungheim and Koschinsky, Diabetes Care, 24:1304:1306 (2001).
[0000] Equilibration Approaches
[0048] While there exist multiple reports that glucose concentrations are very similar when collected from the fingertip or alternative locations, a number of sampling approaches have been recommended to increase localized perfusion at the sample site to equilibrate the values just prior to sampling. Several of these approaches are summarized below:
[0049] Pressure: One sampling methodology requires rubbing or applying pressure to the sampling site in order to increase localized perfusion prior to obtaining a sample via lancet. An example of this is the FREESTYLE blood glucose analyzer (THERASENSE, INC., supra). G. McGarraugh, S. Schwartz, R. Weinstein, Glucose Measurements Using Blood Extracted from the Forearm and the Finger, THERASENSE, INC., ART01022 Rev. C (2001); and G. McGarraugh, D. Price, S. Schwartz, R. Weinstein, Physiological influences on off - finger glucose testing, Diabetes Technology & Therapeutics, 3:367-376 (2001).
[0050] Heating: Heat applied to the localized sample site has been proposed as a mechanism for equalizing the concentration between the vascular system and skin tissue. This may be to dilate the capillaries allowing more blood flow, which leads towards equalization of the venous and capillary glucose concentrations. Alternatively, vasodilating agents such as nicotinic acid, methyl nicotinamide, minoxidil, nitroglycerin, histamine, capsaicin, or menthol can be utilized to increase local blood flow. M. Rohrscheib, C. Gardner, M. Robinson, Method and apparatus for noninvasive blood analyte measurement with fluid compartment equilibration, U.S. Pat. No. 6,240,306 (May 29, 2001).
[0051] Vacuum: Applying a partial vacuum to the skin at and around the sampling site prior to sample collection has also been utilized. A localized deformation in the skin may allow superficial capillaries to fill more completely. T. Ryan, A study of the epidermal capillary unit in psoriasis, Dermatologica, 138:459-472 (1969). For example, ABBOT LABORATORIES, INC. utilizes a vacuum device at one-half atmosphere that pulls the skin up 3.5 mm into their device. ABBOT maintains this deformation results in increased perfusion that equalizes the glucose concentration between the alternative site and the fingertip. R. Ng, Presentation to the FDA at the Clinical Chemistry & Clinical Toxicology Devices Panel Meeting, Gaithersburg Md. (Oct. 29, 2001).
[0000] Calibration:
[0052] Glucose analyzers require calibration. This is true for all types of glucose analyzers such as traditional invasive, alternative invasive, noninvasive, and implantable analyzers. One fact associated with noninvasive glucose analyzers is the fact that they are secondary in nature, that is, they do not measure blood glucose levels directly. This means that a primary method is required to calibrate these devices to measure blood glucose levels properly. Many methods of calibration exist.
[0000] Calibration of Traditional Invasive Glucose Analyzers:
[0053] Glucose meters or analyzers may be calibrated off of biological samples such as whole blood, serum, plasmas, or modified solutions of these samples. In addition, glucose analyzers may be calibrated with a range of whole blood samples, modified whole blood samples, blood simulants, phantoms, or a range of chemically prepared standards. Typically, these samples have glucose concentrations that span the desired functionality range of the glucose analyzer. For glucose analyzers, this is approximately 70 to 400 mg/dL. Some go further into the hypoglycemic range, down to 40 or even 0 mg/dL, while some go well into the hyperglycemic range, up to 700 or 1000 mg/dL.
[0000] Calibration of Alternative Invasive Glucose Analyzers:
[0054] Alternative invasive glucose analyzers utilize many of the invasive glucose calibration procedures. When calibrating the alternative invasive glucose meters that utilize biological fluids such as blood or interstitial fluid as a reference, relatively minor modifications to the traditional calibration approaches may be required.
[0000] Calibration of Noninvasive Glucose Analyzers:
[0055] One noninvasive technology, near-infrared spectroscopy, provides the opportunity for both frequent and painless noninvasive measurement of glucose. This approach involves the illumination of a spot on the body with near-infrared (NIR) electromagnetic radiation, light in the wavelength range 700 to 2500 nm. The light is partially absorbed and scattered, according to its interaction with the constituents of the tissue. The actual tissue volume that is sampled is the portion of irradiated tissue from which light is transflected or diffusely transmitted to the spectrometer detection system. With near-infrared spectroscopy, a mathematical relationship between an in vivo near-infrared measurement and the actual blood glucose value needs to be developed. This is achieved through the collection of in vivo NIR measurements with corresponding blood glucose values that have been obtained directly through the use of measurement tools like the HEMOCUE (YSI INCORPORATED, Yellow Springs Ohio), or any appropriate and accurate traditional invasive reference device.
[0056] For spectrophotometric based analyzers, there are several univariate and multivariate methods that can be used to develop the mathematical relationship between the measured signal and the actual blood glucose value. However, the basic equation being solved is known as the Beer-Lambert Law. This law states that the strength of an absorbance/reflectance measurement is proportional to the concentration of the analyte which is being measured, as in equation 3,
A=εbC (3)
where A is the absorbance/reflectance measurement at a given wavelength of light, ε is the molar absorptivity associated with the molecule of interest at the same given wavelength, b is the distance that the light travels, and C is the concentration of the molecule of interest (glucose).
[0057] Chemometric calibration techniques extract the glucose signal from the measured spectrum through various methods of signal processing and calibration including one or more mathematical models. The models are still developed through the process of calibration on the basis of an exemplary set of spectral measurements known as the calibration set and associated set of reference blood glucose values based upon an analysis of fingertip capillary blood or venous blood. Common multivariate approaches requiring an exemplary reference glucose concentration vector for each sample spectrum in a calibration include partial least squares (PLS) and principal component regression (PCR). Many additional forms of calibration are known, such as neural networks.
[0058] Because every method has error, it is desirable that the primary device used to measure blood glucose be as accurate as possible to minimize the error that propagates through the mathematical relationship developed. While it appears reasonable to assume that any FDA-approved blood glucose monitor should be suitable, for accurate verification of the secondary method, a monitor having a percentage error of less than 5 percent is desirable. Meters with increased percentage error such as 10 percent may also be acceptable, though the error of the device being calibrated may increase.
[0059] Although the above is well-understood, one aspect that is forgotten is that secondary methods require constant verification that they are providing consistent and accurate measurements when compared to the primary method. This means that a method for checking blood glucose values directly and comparing those values with the given secondary method is required. Such monitoring is manifested in quality assurance and quality control programs. Bias adjustments are often made to a calibration. In some cases the most appropriate calibration is selected based upon these secondary methods. S. Malin, T. Ruchti, Intelligent system for noninvasive blood analyte prediction, U.S. Pat. No. 6,280,381 (Aug. 28, 2001). This approach is also known as validation.
[0000] The Problem:
[0060] Calibration of a noninvasive glucose analyzer entails some complications not observed in traditional invasive glucose analyzers. For example, spectroscopic or spectrophotometric based noninvasive glucose analyzers probe a sample that is not entirely whole blood or interstitial fluid. Photons penetrate into the body, interact with body layers and/or tissues and are detected upon reemerging from the body. Hence, many possible interferences exist that do not exist in a prepared reference or calibration sample. In addition, the interferences and matrices encountered are part of a living being and hence are dynamic in nature. For these reasons, indirect calibration is often attempted with traditional invasive reference glucose determinations collected from the fingertip. This approach, however, introduces errors into the noninvasive analyzer that are associated with sampling the reference glucose concentration. One key source of error is the difference between glucose concentrations at the site tested by the noninvasive glucose analyzer and the reference site sampled with an invasive technology. Thus, it would be an important advance in the art to provide methods for calibrating and maintaining signal-based analyzers that addressed the negative effect on their accuracy and precision that results from calibrating them based on invasive reference samples taken at sites distant from the site of noninvasive sampling.
SUMMARY OF THE INVENTION
[0061] The invention provides a method and apparatus for using either alternative invasive glucose determinations or alternative site noninvasive glucose determinations to calibrate noninvasive or implantable glucose analyzers. Use of an alternative invasive or alternative site noninvasive glucose determination in the calibration allows for minimization of errors built into the glucose analyzer model, including errors due to sampling, methodology, and errors due to temporal and spatial variations of glucose concentration within the subject's body. In addition, the invention provides conversion of glucose concentrations determined from noninvasive or alternative reference determinations into traditional invasive glucose determinations. As described herein, the use of an alternative invasive or noninvasive glucose determination for calibration is also understood to include their use for glucose determination, prediction, calibration transfer, calibration maintenance, quality control, and quality assurance.
[0062] The use of alternative invasive or alternative site noninvasive reference determinations provides a means for calibrating on the basis of glucose determinations that reflect the matrix observed and the variable measured by the analyzer more closely. Statistical correlations between noninvasive and alternative invasive glucose determinations and traditional invasive glucose determinations may then be used to adjust alternative site noninvasive or alternative invasive glucose concentrations to traditional invasive glucose concentrations. The invention also provides an apparatus in which an invasive stick meter is coupled to a noninvasive glucose analyzer for calibration, validation, adaptation, and safety check of the calibration model embodied in the noninvasive analyzer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0063] FIG. 1 provides a plot of glucose measurements that demonstrates large differences in glucose concentration between the fingertip and forearm according to the invention;
[0064] FIG. 2 provides a plot of glucose measurements that demonstrates a lag in glucose concentrations determined from the forearm compared to the fingertip according to the invention;
[0065] FIG. 3 shows a plot of fingertip and forearm glucose concentrations that are well correlated;
[0066] FIG. 4 illustrates a plot that demonstrates historesis in glucose concentration profiles resulting in differences in glucose concentration between the fingertip and forearm even when glucose concentrations are at a local minimum with respect to time according to the invention;
[0067] FIG. 5 provides a plot of forearm glucose concentrations against corresponding fingertip glucose concentrations with a relatively large error according to the invention;
[0068] FIG. 6 provides a plot of forearm glucose concentrations against corresponding contralateral forearm glucose concentrations with a smaller error when compared to FIG. 5 , according to the invention;
[0069] FIG. 7 shows a block diagram of a noninvasive analyzer using alternative site glucose determinations calibration and maintenance according to the invention;
[0070] FIG. 8 shows a plot of predicted glucose concentrations versus reference forearm glucose determinations according to the invention;
[0071] FIG. 9 provides a plot of predicted glucose concentration versus traditional invasive reference glucose concentrations;
[0072] FIG. 10 provides a histogram demonstrating a statistical difference in the histogram shift of predicted glucose concentrations versus fingertip and forearm reference concentrations according to the invention;
[0073] FIG. 11 provides a histogram demonstrating a statistical difference in the histogram magnitude of predicted glucose concentrations versus fingertip and forearm reference concentrations according to the invention;
[0074] FIG. 12 provides a plot of subjects demonstrating dampened and lagged glucose predictions versus traditional invasive reference glucose concentrations according to the invention;
[0075] FIG. 13 illustrates a concentration correlation plot of the series of subjects with dampened and lagged glucose predictions versus traditional invasive reference glucose concentrations according to the invention;
[0076] FIG. 14 shows a plot of lag and magnitude adjusted glucose predictions overlaid with traditional invasive glucose determinations according to the invention;
[0077] FIG. 15 provides a concentration correlation plot of the lag and magnitude adjusted glucose predictions versus traditional invasive reference glucose concentrations according to the invention;
[0078] FIG. 16 shows an algorithm-adjusted concentration correlation plot of predicted glucose concentration versus traditional reference glucose concentrations according to the invention; and
[0079] FIG. 17 shows a block diagram of an apparatus including a noninvasive glucose analyzer coupled with an invasive (traditional or alternative) glucose monitor according to the invention.
DETAILED DESCRIPTION
[0080] The present invention reduces the error in the reference glucose concentration for the calibration of glucose sensors and therefore leads to a more accurate, precise, and robust glucose measurement system.
[0000] DIFFERENCE IN TRADITIONAL INVASIVE AND ALTERNATIVE INVASIVE GLUCOSE CONCENTRATION
[0081] Initially, differences between traditional invasive and alternative invasive glucose determinations are demonstrated. It is demonstrated here that the differences between the alternative invasive glucose concentration from a site such as the forearm and the glucose concentration from a traditional invasive fingerstick vary as a function of at least time and location. Additional parameters include sampling methodology, physiology, and glucose analyzer instrumentation.
EXAMPLE 1
[0082] In a first example, variation of glucose concentration at locations in the body is demonstrated at fixed points in time. A total of twenty diabetic subjects were run through one of two glucose profiles each having two peaks so that the resulting curves formed the shape of an ‘M,’ shown in part in FIG. 1 , over a period of eight hours. Thus, glucose concentration started low at around 80 mg/dL, was increased to approximately 350 mg/dL, and was brought back to about 80 mg/dL in a period of about four hours. The cycle was immediately repeated to form an ‘M’-shaped glucose concentration profile. These profiles were alternately generated with intake of a liquid form of carbohydrate (50-100 g) or intake of a solid form of carbohydrate (50-100 g) in combination with insulin to generate the two excursions of the ‘M’ profile. Traditional invasive fingertip capillary glucose concentrations were determined every 15 minutes throughout the 8-hour period. Each fingertip determination was immediately followed by an alternative invasive capillary glucose determinations wherein samples were collected from the volar aspect of the subject's right and then left forearms. The resulting data set included 1920 data points (20 subjects * 3 sites/15 minutes * 32 draws/day). J. Fischer, K. Hazen, M. Welch, L. Hockersmith, J. Coates, Comparisons of capillary blood glucose concentrations from the fingertips and the volar aspects of the left and right forearms, American Diabetes Association, 62 nd Annual Meeting, (Jun. 14, 2002). The ‘M’-shaped profiles described above may be induced according to procedures previously set forth in L. Hockersmith, A method of producing a glycemic profile of predetermined shape in a test subject, U.S. patent application Ser. No. 09/766,427 (Jan. 18, 2001), the entirety of which is hereby incorporated by reference as if fully set forth herein.
[0083] Four partial ‘M’ profiles from the above study are presented here. In FIG. 1 , alternative invasive glucose concentrations measured at the forearm are demonstrated to have both a dampened and a lagged profile versus the traditional invasive fingertip glucose concentrations. For this individual, when the glucose concentration was rising the forearm glucose concentrations are observed to be substantially dampened, that is lower than the corresponding fingertip glucose concentration. For example, at the 90 minute mark the fingertip glucose concentration of 234 mg/dL is more than 100 mg/dL higher than either the left or right forearm glucose concentration of 123 and 114 mg/dL, respectively. In addition, the peak glucose concentration observed at the fingertip of 295 mg/dL is both larger and occurred 30 minutes earlier than the peak forearm glucose concentration of 259 mg/dL. Finally, the forearm glucose concentrations have a small lag versus the fingertip glucose concentrations. FIG. 2 presents another glucose profile in which many of the same effects just described are observed but to a lesser degree. For example, the rising glucose concentrations of the alternative invasive forearm glucose concentrations are still less than those of the traditional invasive fingertip glucose concentrations, but the difference is smaller. A dampening and lag of the alternative invasive peak are still observed. One measure of dampening is the range of traditional invasive glucose concentrations minus the range of alternative invasive glucose concentrations. In addition, the lag is more pronounced than in the previous figure. FIG. 3 demonstrates another example in which the forearm glucose concentrations closely track those of the fingertip glucose concentrations. Finally, FIG. 4 demonstrates a historesis effect as a subject moves through subsequent glucose excursions. That is, a lag observed in a forearm may still be observed at a later time. In this case, dampening of the forearm glucose concentration is observed at a glucose minimum relative to that of the fingertip glucose concentration. The effects observed above are representative as a whole of the glucose profiles observed in the study outlined above.
[0084] As in FIG. 5 , alternative invasive glucose determinations collected from the volar aspect of each subject's left and right forearm are plotted against the time-associated traditional invasive fingertip reference glucose concentration for all subjects in a concentration correlation plot overlaid with a Clarke error grid. The standard error of the forearm glucose concentrations versus the fingertip glucose concentration is relatively large at 37.7 mg/dL with an F-value of 4.43. The best fit of the data yields a slope of 0.76 and an intercept of 41.4 mg/dL. This is consistent with dampened and delayed forearm glucose profiles relative to the fingertip and results in only 73.8% of the points falling in the ‘A’ region of the Clarke error grid.
[0085] The glucose determinations collected from the volar aspect of each subject's left and right forearm are plotted against each other for all subjects on a Clarke error grid in FIG. 6 . The standard error of the left forearm glucose concentrations versus the right forearm glucose concentration is reduced to 17.2 mg/dL with an F-value of 16.0. The best fit of the data yields a slope of 0.96 and an intercept of 8.3 mg/dL. This is consistent with a reduction in the dampening and delay of left forearm glucose profiles relative to the right forearm glucose concentrations and results in 95.8 percent of the points falling in the ‘A’ region of the Clarke error grid. A slope of 0.96, combined with the low standard error, indicates that the capillary blood glucose values of the left and right volar forearm would be similar.
[0086] These data suggest several conclusions:
during a glucose excursion, substantial differences are often observed between the capillary blood glucose of the untreated forearm and the fingertip; fast changes in blood glucose concentration magnify differences between the measured blood glucose concentration of the fingertip and forearm while the relative errors are proportional to the glucose concentration; during periods of rapid change in blood glucose concentration, differences between the forearm and fingertip give rise to a higher percentage of points in less desirable regions of the Clarke error grid; the measured blood glucose concentrations of the volar aspect of the left and right forearms appear similar; and finally, these findings are consistent with the phenomenon of decreased perfusion into the forearm versus that of the fingertip, leading to a dampening and/or lag in the glucose profile.
[0092] These conclusions are consistent with those reported in the circulatory physiology literature and that relating to sampling approaches of alternative invasive glucose analyzers. It has been reported that blood flow in the fingers is 33±10 mL/g/min at 20° C. while in the leg, forearm, and abdomen the blood flow is 4-6 mL/g/min at 19-22° C. V. Harvey, Sparks, skin and muscle, in: Peripheral Circulation, P. Johnson, ed., p. 198, New York (1978). This is consistent with the observed differences in localized blood glucose concentration. When glucose concentrations vary rapidly a difference develops throughout the body in local blood glucose concentrations as a result of differences in local tissue perfusion. For example, the blood flow in the fingers of the hand is greater than in alternative sites. This means that the blood glucose in the fingertips will equilibrate more rapidly with venous blood glucose concentrations. Furthermore, the magnitude of differences in local glucose concentrations between two sites is related to the rate of change in blood glucose concentrations. Conversely, under steady-state glucose conditions, the glucose concentration through-out the body tends to be uniform.
[0093] An additional study demonstrated that localized variations in the glucose concentration in the dorsal versus volar aspect of the forearm are small versus differences between the glucose concentrations observed in either forearm region versus that of the fingertip. J. Fischer, K. Hazen, M. Welch, L. Hockersmith, R Guttridge, T. Ruchti, physiological differences between volar and dorsal capillary forearm glucose concentrations and finger stick glucose concentrations in diabetics, American Diabetes Association, 62 nd Annual Meeting (Jun. 14, 2002).
[0094] Another study demonstrated very small localized variation in glucose concentration within a region such as the dorsal aspect of the forearm with observed differences approximating the scale of the error observed in the reference method. The glucose concentrations in the forearm are not observed to vary within three inches laterally or axially from a central point of the forearm.
[0095] In addition to differences in perfusion, the local permeability of tissue to diffusion and the local uptake of glucose during exercise or other activity can cause non-uniform distribution of glucose in the body. Finally, when the noninvasive variable and the reference glucose concentration are not measured simultaneously, an additional error can occur when glucose is varying in the body.
[0000] Physiology
[0096] The following physiological interpretations are deduced from these studies:
during times of glucose change, the glucose concentration as measured on the arm can lag behind that of the fingertip; a well-recognized difference between the fingertip and the forearm is the rate of blood flow; differences in circulatory physiology of the off-finger test sites may lead to differences in the measured blood glucose concentration; on average, the arm and finger glucose concentrations are approximately the same, but the correlation is not one-to-one. This suggests differences between traditional invasive glucose concentrations and alternative invasive glucose concentrations are different during time periods of fasting and after glucose ingestion; the relationship of forearm and thigh glucose levels to finger glucose is affected by proximity to a meal. Meter forearm and thigh results during the sixty and ninety minute postprandial testing sessions are consistently lower than the corresponding finger results; differences are inversely related to the direction of blood glucose concentration change; rapid changes may produce significant differences in blood glucose concentrations measured at the fingertip and forearm; and for individuals, the relationship between forearm and finger blood glucose may be consistent. However, the magnitude of the day-to-day differences has been found to vary. Finally, interstitial fluid (ISF) may lead plasma glucose concentration in the case of falling glucose levels due to exercise or glucose uptake due to insulin.
Utilization of the Difference in Traditional Invasive and Alternative Invasive Glucose Concentration
[0105] The discrepancy between the glucose level at the non-invasive measurement site versus the reference concentration presents a fundamental issue in relation to calibration. A calibration is generally a mathematical model or curve that is used to convert the noninvasively measured variable such as absorbance, voltage, or intensity to an estimate of the glucose concentration. Determination of the calibration is performed on the basis of a set of paired data points composed of noninvasive variables and associated reference blood glucose concentrations collected through a blood draw. Any error introduced by the reference method is propagated into any error associated with the indirect method as an uncertain, imprecise, and/or biased calibration.
[0000] Method
[0106] The invention provides a method of developing a calibration based on either traditional or alternate invasive reference glucose measurements. The percentage error in the reference glucose concentration is reduced through the application of one or more techniques that improve correspondence between the reference glucose concentration and the glucose concentration reflected in the variable measured by the sensor, herein referred to as the “sensor variable”, thus producing a superior exemplary set of calibration data for calculating the calibration curve or model. Both noninvasive and implantable glucose analyzers require a calibration because they rely on measurement of glucose indirectly from a blood or tissue property, fluid, parameter, or variable. While the target application is typically an optical sensor, any device that measures glucose through a calibration falls within the scope of the invention. Examples of such systems include:
near-infrared spectroscopy (700-2500 nm), O. Khalil, Spectroscopic and clinical aspects of non - invasive glucose measurements,” Clin Chem, 45:165-77 (1999); far-infrared spectroscopy; mid-infrared spectroscopy; Raman spectroscopy; fluorescence spectroscopy; spectroscillating thermal gradient spectrometry, P. Zheng, C. Kramer, C. Barnes, J. Braig, B. Sterling, Noninvasive glucose determination by oscillating thermal gradient spectrometry, Diabetes Technology & Therapeutics, 2:1:17-25; impedance based glucose determination; nuclear magnetic resonance; optical rotation of polarized light; radio wave impedance; fluid extraction from the skin; glucose oxidase and enzymatic sensors; interstitial fluid harvesting techniques (e.g. microporation or application of a small electric current) or glucose electrode; and microdialysis.
[0121] As previously described, the calibration set constitutes a set of paired data points collected on one or more subjects; and generally includes glucose concentrations that span the expected range of glucose variation. Each paired data point includes a reference glucose value and an associated value or values of the sensor variable.
[0122] The invented method relies on a variety of processes that improve the reference values of the calibration set, which can be used independently or together.
[0123] First is a process for calibrating using a calibration set of paired data points including a reference glucose value from a traditional invasive method or an alternative invasive method and a noninvasive sensor measurement. This first process is based on the recognition that glucose tends to be uniform throughout the tissue under steady state conditions and that perfusion is the dominant physiological process leading to differences in glucose under dynamic situations. Within the context of this first process, a number of techniques are suggested for improving reference values with respect to their corresponding sensor values:
Paired data points are collected at intervals that allow determination of the rate of glucose change. For example, traditional invasive glucose determinations and noninvasive signals may be generated every 15 minutes for a period of four hours. The resulting calibration set is limited to paired data points with a corresponding rate of glucose change less than a specified maximum level. Calibration data is collected during periods of stasis or slow change in glucose concentration. The rate of acceptable change in glucose concentration is determined on the basis of the tolerable error in the reference values. For example, a rate of change of 0.5 mg/dL/minute may be found to be acceptable; Under dynamic conditions, the circulation at a measurement site is perturbed, both for an alternative invasive measurement site for calibration and later for measuring glucose utilizing an alternative invasive glucose analyzer. Enhancement of circulation in the forearm or alternate testing site, for example, causes the local glucose concentrations to approach those of the fingertip. As described above, methods for perturbing circulation may include ultrasound, or a variety of surface applications that cause vasodilatation, mechanical stimulation, partial vacuum, and heating; Patients are screened according to the discrepancy between their traditional invasive glucose concentration at a fingertip or toe and an alternative invasive glucose determination at the alternative invasive site. For example, subjects with significant discrepancy between the glucose concentration in the fingertip and the local tissue volume sampled through a near-infrared device, such as a forearm, would not be used for calibration. Subjects having a small difference in glucose concentration between the traditional invasive and alternative invasive measurement site would be used for calibration. On this basis subjects are further screened for device applicability for subsequent glucose predictions; and Using post-processing techniques, the sensor's estimate of the glucose concentration is corrected. The method utilizes an estimate of the time lead or lag between the two glucose concentrations from a cross-correlation or time series analysis and a correction using an interpolation procedure. A similar correction would correct for a dampening of the noninvasive signal relative to a traditional invasive signal.
[0129] In a second process, careful site selection assures that reference values reflect the concentration of glucose in the sensor variable. According to this process, blood, serum, plasma, interstitial draws, or selective interstitial sample acquisitions are taken from a tissue site that is either near the sensor sample site or has been designed/determined to reflect the sample site. For example, when noninvasive (sensor) near-infrared measurements are taken for calibration on a forearm, it is possible in some individuals to collect a capillary blood draw from an alternative invasive sample site such as the same forearm or from the opposite forearm. The blood draws are taken in a manner that maintains perfusion equivalence to the noninvasive sample site.
[0130] It is noted that alternative invasive glucose determinations acquire samples from varying depths. Some acquire interstitial fluid from just below the epidermal later while others penetrate into capillary blood or subcutaneous fluids. Because a noninvasive glucose analyzer can be tuned to sense glucose concentrations from different depths, a logical choice of a reference device is an alternative invasive analyzer sampling from a similar depth in the skin. For example, a near-IR glucose analyzer functioning in the 2100 to 2300, 1550 to 1800, or 1100 to 1350 nm region acquires signal from approximately 1.5, 3, and 5 mm, respectively. Similarly, a glucose analyzer functioning within 50 nm of 1450, 1900 or 2500 nm samples at depths of less than 1 mm. Hence, noninvasive technologies that rely on tissue volumes primarily including the epidermis indirectly measure primarily interstitial glucose concentrations and may benefit from alternative invasive glucose analyzers sampling the interstitial fluid from the epidermis versus an alternative invasive glucose analyzer that samples blood from the dermis.
[0131] Finally, glucose varies dynamically through time in individuals. When a glucose determination through a blood or interstitial sample cannot be taken simultaneously with the sensor variable an error can exist due to the time differential. A technique for reducing this error is based on interpolation and extrapolation of the reference glucose values to the time the sensor variable was collected.
[0000] INSTRUMENTATION
[0000] Noninvasive
[0132] A number of technologies have been reported for measuring glucose noninvasively that involve the measurement of a tissue related variable. Examples include but are not limited to far-infrared absorbance spectroscopy, tissue impedance, Raman, and fluorescence, as well as techniques using light from the ultraviolet through the infrared [ultraviolet (200 to 400 nm), visible (400 to 700 nm), near-IR (700 to 2500 nm or 14,286 to 4000 cm −1 ), and infrared (2500 to 14,285 nm or 4000 to 700 cm −1 )]. These techniques share the common characteristic that they are indirect measurements of glucose. A calibration is required in order to derive a glucose concentration from subsequent collected data. In the past, capillary finger blood glucose and venous blood glucose have been utilized to generate these calibrations. However, as has been shown, these traditional invasive glucose determinations do not always represent the glucose concentration at the sampled site.
[0133] A number of spectrometer configurations are possible for collecting noninvasive spectra of body regions. Typically, a spectrometer, also called a sensor, has one or more beam paths from a source to a detector. A light source may comprise a blackbody source, a tungsten-halogen source, one or more LED's, or one or more laser diodes. For multi-wavelength spectrometers a wavelength selection device may be utilized or a series of optical filters may be utilized for wavelength selection. Wavelength selection devices comprise dispersive elements such as one or more plane, concave, ruled, or holographic grating. Additional wavelength selective devices include an interferometer, successive illumination of the elements of an LED array, prisms, and wavelength selective filters. However, variation of the source such as varying which LED or diode is firing may be utilized. Detectors may in the form of one or more single element detectors or one or more arrays or bundles of detectors. Single element or array detectors maybe fabricated from InGaAs, PbS, PbSe, Si, MCT (mercury-cadmium-tellurium), or the like. Light collection optics such as fiber optics, lenses, and mirrors are commonly utilized in various configurations within a spectrometer to direct light from the source to the detector by way of a sample. The mode of operation may be transmission, diffuse reflectance, or transflectance. Due to changes in performance of the overall spectrometer, reference wavelength standards are often scanned. Typically, a wavelength standard is collected immediately before or after the interrogation of the tissue, but may also occur at times far removed such as when the spectrometer was originally manufactured. A typical reference wavelength standard would be polystyrene or a rare earth oxide such as holmium, erbium, or dysprosium oxide.
[0134] The interface of the glucose analyzer to the tissue includes a patient interface module and light such as near-infrared radiation is directed to and from the tissue either directly or through a light pipe, fiber-optics, a lens system, or a light directing mirror system. The area of the tissue surface to which near-infrared radiation is applied and the area of the tissue surface the returning near-infrared radiation is detected from are different and separated by a defined distance and their selection is designed to enable targeting of a tissue volume conducive to measurement of the property of interest. The patient interface module may include an elbow rest, a wrist rest, and/or a guide to assist in interfacing the illumination mechanism of choice and the tissue of interest. Generally, an optical coupling fluid is placed between the illumination mechanism and the tissue of interest to minimize specular reflectance from the surface of the skin.
[0135] A preferred embodiment of the sensor 700 , shown in FIG. 7 , is a spectroscopic measurement system that includes a tungsten halogen near-infrared radiation source, a wavelength selection filter 702 passing 1100 to 1900 nm light, fiber optics 703 for conveying the source photons to an in-vivo skin sample, an interface 704 to the forearm of a patient, fiber optic collection optics 705 for gathering diffusely reflected and transflected radiation from the skin to a grating, and an InGaAs array 706 to detect the radiation, electronic means 707 for converting the resulting signal into a glucose concentration and a display (not shown). D. Klonoff, Noninvasive blood glucose monitoring, Diabetes Care, 20:3:433 (March, 1997).
[0136] The sample site constitutes the point or area on the subject's body surface the measurement probe contacts and the specific tissue irradiated by the spectrometer system. Ideal qualities for a sample site include: 1) homogeneity, 2) immutability; and 3) accessibility to the target analyte. Noninvasive glucose analyzers commonly use the fingertip as a sampling site. However, several alternative sampling sites are possible, including the abdomen, upper arm, thigh, hand (palm or back of the hand) or ear lobe, in the preferred embodiment, the volar part of the forearm is used. In addition, while the measurement can be made in either diffuse reflectance or diffuse transmittance mode, the preferred method is diffuse reflectance. Scanning of the tissue can be done continuously when the tissue area being tested is not affected by pulsation effects, or the scanning can be done intermittently between pulses.
[0137] The collected signal (near-infrared radiation in this case) is converted to a voltage and sampled through an analog-to-digital converter for analysis on a microprocessor based system and the result displayed.
[0000] Implantable:
[0138] In an alternate arrangement, the system or a portion of the system is implanted, and the measurement is made directly on soft tissue, muscle, a blood vessel or skin tissue within the body. In this configuration, the measurement is made in a manner that is non-invasive to the probed tissue although the system or a portion of the system is implanted within the body. For example, the peritoneal cavity is a suitable location for implantation and both the probing signal source and detection system are implanted. In the preferred embodiment, telemetry is employed to transfer data or actual analyte readings to a remote location outside the body. Alternately, a transcutaneous connector is employed. After transfer, the data or concentration are then processed and displayed to the user or heath care provider. Three different embodiments of the implanted system are disclosed. The first, a consumer version, is used for incremental or continuous applications requiring intensive analysis of body analytes (e.g., glucose). A particularly useful application is nocturnal monitoring of glucose and detection or prediction of hypoglycemic events. In the second, the system is employed in a health care facility and the analyte is monitored via a computer or health care provider. A third embodiment of the implanted system is for use in a closed-loop insulin delivery system. In this embodiment the system is a sub-component of an artificial pancreas and used to monitor glucose levels for insulin dosage determination via an insulin pump.
[0139] In implantable embodiments, an alternative invasive or noninvasive reference glucose concentration or set of concentrations may be utilized with paired implantable signals in order to calibrate an implantable glucose analyzer. This is essentially the same as utilizing an alternative invasive glucose analyzer to calibrate a noninvasive glucose analyzer as discussed above. Utilization of an alternative invasive or noninvasive reference is beneficial in instances when the implantable glucose analyzer is sampling fluids or tissues that have perfusion similar to that of the alternative invasive sites. For example, a semi-implantable device may be placed into the subcutaneous tissue or an implantable device may be placed into the peritoneal cavity. Both of these regions may have dampened and lagged glucose concentrations that are similar to alternative invasive glucose determinations or noninvasive glucose determinations from regions that are not well perfused. Hence, the reference values will more closely represent the implantable signals. This will aid in calibration design and maintenance as above.
[0000] CORRECTION OF ALTERNATIVE INVASIVE TO TRADITIONAL INVASIVE GLUCOSE CONCENTRATION
[0140] In building a glucose calibration model, a number of measurement parameters must be considered. The selection of measurement parameters will greatly affect predicted glucose concentrations from subsequent spectra. For example, for glucose determination based on near-IR spectral measurements, parameters include sample selection, preprocessing step selection, and actual model parameters such as the number of factors in a multivariate model. In view of the demonstrated difference in glucose concentration between traditional and alternative measurements, selection of the appropriate set of glucose reference concentrations is also important.
[0141] For example, a model may be based on a calibration set that utilizes alternative invasive forearm glucose concentrations from the dorsal aspect of the forearm and near-IR noninvasive glucose determinations from the forearm. By using such a model to predict glucose concentrations from subsequent spectra, the subsequent measurements for a large number of subjects will correspond to the values of the calibration set more closely than if the calibration set were based on traditional invasive glucose determinations from a fingertip. The importance of parameter selection is described in greater detail below. Furthermore, a method for correcting measurements based on a calibration set of traditional invasive glucose determinations to approximate those based on a set of alternative invasive determinations is provided.
EXAMPLE
[0142] A single calibration model was applied to 4,980 noninvasive spectra collected from the volar aspect of the forearm of twenty-six subjects covering 233 unique visits utilizing nine instruments collected over a period of eight months. Each subject was tested every fifteen minutes for a period of approximately eight hours. The resulting glucose predictions were compared to both traditional invasive reference fingertip and alternative invasive reference forearm glucose concentrations.
[0143] A concentration correlation plot of the predicted glucose concentrations versus the forearm reference glucose concentrations is presented in FIG. 8 . A Clarke error grid analysis for this data demonstrates that 81.9 and 17.9 percent of the data falls into the A and B region, respectively. Thus, 99.8 percent of the data are predicted clinically accurately versus the alternative invasive reference forearm glucose concentrations. However, as shown in FIG. 9 , accuracy diminishes when plotted against the corresponding traditional invasive reference fingertip glucose concentrations. Clarke error grid analysis still results in 96.9% of the data in the ‘A’ or ‘B’ regions; however, only 51.5% fall into the ‘A’ region. The correction methodology follows:
For each subject, lag of the predicted glucose concentration versus reference glucose concentrations for both fingertip and forearm determination is calculated. In order to account for the difference between the predicted values and the reference, a phase correction is calculated using a cross-covariance based algorithm by sliding the x-axis (time vector) of the predicted values a fixed amount to synchronize the predicted and reference values. A histogram of the resultant lags is presented in FIG. 10 . Lags for the forearm are observed to range up to sixty-two minutes. The peak of the lag for the comparison against the forearm and the fingertip is approximately ten and 33.6 minutes, respectively. This indicates that the model substantially tracks the forearm glucose concentrations better than glucose concentrations from the fingertip, a result of the model being built with forearm glucose concentrations. For each subject, a magnitude correction is calculated comparing the predicted glucose concentrations to each of the fingertip and forearm glucose concentration reference profiles. The magnitude correction constitutes the difference between the glucose concentration ranges of the predicted and reference values. It is observed that the average difference between the predicted and reference glucose concentrations is less for the forearm reference glucose determinations than it is for the fingertip reference glucose determinations. A ratio of the range of the predicted values versus the range of the reference values is calculated for each subject's visit. A histogram of the resulting ratios representative of the magnitude difference is presented in FIG. 11 . The histogram demonstrates ratios closer to one for the forearm glucose concentration range with peak values for the forearm and fingertip of 0.71 and 0.55, respectively. A third parameter not utilized in this particular model is a correction of the frequency of glucose profile versus time. Thus, the rate of glucose increase to a peak value and the rate of a subsequent decline may differ for traditional invasive glucose determinations and alternative invasive glucose determinations, and this profile shape difference or period may be corrected.
[0147] It is here noted that specific examples of parameter calculations are presented, but that those skilled in the art will immediately appreciate that the lag, dampening, and frequency parameters and similar parameters utilized to characterize population differences may be calculated in a number of ways, any of which are consistent with the spirit and scope of the invention. For example, phase correction may be performed with techniques such as a Bessel filter, warping of the time axis and re-sampling, development of a wavelet-based model and subsequent time compression, or shifting. Similarly, magnitude correction may be performed with a simple multiplication factor after centering the data to either the mean or single data point, a multiplication factor dependent upon the rate of change, a multiplication factor dependent upon time, a multiplication factor dependent upon the tissue state, or a multiplication factor dependent upon the type of diabetes or class of tissue. Additionally, it is noted that incomplete vectors may still be utilized to determine these or similar parameters.
[0148] A multi-step correction method may then be implemented utilizing one or more of these parameters. In one example, a shift correction is followed by a magnitude correction. First, the mean shift value of 33.6 minutes is subtracted from the prediction time vector. Second, a magnitude correction is performed. Initially, the shift corrected data is mean centered. Then, the resulting glucose concentrations are divided by 0.55. Finally, the mean of the shift corrected data is added to the resulting vector of data.
[0149] The two-step correction with parameters of a shift adjustment of 33.6 minutes and a scaling factor of 0.55 produced above is here applied to a set of 7 daily visits from a total of 3 subjects representing noninvasive spectra collected from 3 near-IR glucose analyzers. The fingertip reference glucose concentrations and noninvasively predicted glucose concentration profiles are presented in FIG. 12 . The noninvasive glucose concentrations predicted from spectra collected from the forearm are clearly damped and lagged versus the corresponding traditional invasive glucose determinations. The corresponding concentration correlation plot overlaid with a Clarke error grid is presented in FIG. 13 . The algorithm corrected glucose profiles and corresponding concentration correlation plot is presented in FIGS. 14 and 15 , respectively. Notably, the lag and dampening have been greatly reduced. The respective statistics for the uncorrected and corrected glucose concentrations reveal an obvious improvement in accuracy. The statistics for the uncorrected and corrected glucose concentrations are Clarke ‘A’ region: 49.7 and 80.5%; r: 0.78 and 0.96, F-value: 2.38 and 10.9, standard error 54.4 and 26.0 mg/dL, respectively.
[0150] The two-step correction demonstrated above was applied to the entire data set. The corrected predicted fingertip glucose concentrations are presented in a concentration correlation plot superimposed onto a Clarke error grid, FIG. 16 . The corrected glucose concentrations result in 97.8% of the points falling into the ‘A’ or ‘B’ region of the Clarke error grid. The correlation coefficient, F-Value, and r value each showed a corresponding increase. In addition, the algorithm allows conversion back and forth between forearm and fingertip glucose concentrations.
[0151] While the preceding description has been directed primarily to calibration sets that include invasive reference measurements, embodiments of the invention are possible that employ noninvasive reference measurements. The above data emphasize the importance of taking reference measurements at a site having perfusion equivalence to the sampling site. Accordingly, the principles previously discussed are equally applicable to calibrations developed using noninvasive reference measurements, rather than invasive reference measurements.
[0000] INTEGRATED GLUCOSE ANALYZER
[0152] An integrated glucose analyzer 1700 that utilizes alternative invasive or traditional invasive glucose determinations in combination with noninvasive measurements is shown in FIG. 17 .
[0153] The invention includes a first component 1701 that measures an analytical signal from the body to determine the body's glucose concentration. Numerous noninvasive devices have been described above. In one embodiment of the invention, a near-infrared spectrometer configured for a noninvasive diffuse reflectance measurement from the forearm may be utilized. The first component 1701 includes a control and processing element 1703 for executing computer-readable instructions and at least one storage element 1704 , such as a memory, having executable program code embodied therein for converting a series of reflected near-IR signals, collected from the forearm or other tissue site, into a corresponding series of blood glucose values.
[0154] A second component 1702 , that provides either a traditional invasive or alternative glucose measurement, is electronically coupled 1706 a and b to the first component. Preferably, the second component provides measurements having five percent error or less.
[0155] The above program code also includes code for:
extracting the data from the traditional second component 1702 ; storing the invasive blood glucose values extracted from the second component 1702 in the storage element 1704 of the first component 1701 ; and using the stored invasive blood glucose values for calibration, calibration assignment, validation, quality assurance procedures, quality control procedures, adjustment, and/or bias correction, depending on the current mode of operation. For example, in the case of calibration, finger stick-based blood glucose values are collected concurrently with noninvasive spectra to form a calibration set of paired data points. The set is used to calculate a mathematical model suitable for determination of blood glucose on the basis of a noninvasive measurement, such as a spectrum. As a second example, in the case of bias adjustment, invasive blood glucose determinations are collected with the first noninvasive glucose determination of the day and utilized to adjust the noninvasive glucose concentration to the reference glucose determination. The adjustment parameter is utilized until a new invasive reference glucose determination is collected.
[0160] The above program code also includes code for:
providing a comparison and evaluation of the finger stick blood glucose value to the blood glucose value obtained from the noninvasive near-infrared diffuse reflectance measurement.
[0162] In one embodiment, information is communicated to the first component 1701 from the second component 1702 . Alternatively, the second component 1702 may containing processing and storage elements, instead of the first component. Noninvasive glucose measurements are configured to operate in modes (transmission, diffuse reflectance, and transflectance) as described above on body parts as described above.
[0163] Finally, although the preferred embodiment employs fingerstick measurements, any measurement having sufficient accuracy and precision can be used as the reference measurement.
[0164] There is a pronounced disadvantage to conventional systems, in which a primary device and a secondary device are separate and distinct from each other. Secondary measurements must be compared to primary measurements, in order to validate the secondary measurements. Conventionally, comparison requires the consumer to manually input a blood glucose value from the primary device (traditional or alternative invasive glucose analyzer) into the secondary device (noninvasive or implantable glucose analyze) for comparison. An inherent risk to such an approach is the improper input of the primary glucose value into the secondary device, thus resulting in an invalid comparison.
[0165] Advantageously, the integrated glucose analyzer eliminates the necessity for the patient to manually input an invasive measurement for comparison with the noninvasive measurement. A second advantage is the ability to utilize a single case for both components with a similar power supply and display. This results in fewer elements that a person with diabetes need carry with them. An additional advantage is a backup glucose analyzer in the event of the noninvasive glucose analyzer failing to produce a glucose value as may be the case with very high or hypoglycemic glucose concentrations. A third advantage is traceability. The time difference between a reference glucose determination from an invasive meter and a corresponding noninvasive glucose reading may be critical in establishing a correction to an algorithm such as a bias. An automated transfer of the glucose value and the associated time greatly reduces risks in usage of a noninvasive analyzer that requires such a correction. Finally, the transfer of glucose and time information into the noninvasive analyzer digital storage means eases subsequent analysis and data management by the individual or a professional.
[0166] This technology may be implemented in healthcare facilities including, but not limited to: physician offices, hospitals, clinics, and long-term healthcare facilities. In addition, this technology would be implemented for home-use by consumers who desire to monitor their blood glucose levels whether they suffer from diabetes, impaired glucose tolerance, impaired insulin response, or are healthy individuals.
[0167] Additionally, an embodiment is possible in which the first and second components are separate analyzers, the first component configured to measure glucose noninvasively, and the second component configured to perform either alternate invasive or traditional invasive measurements. In the current embodiment, first and second components are electronically coupled by means of a communication interface, such as RS232 or USB (universal serial bus). Other commonly-known methods of interfacing electrical components would also be suitable for the invention, such as telemetry, infrared signals, radiowave, or other wireless technologies. Either embodiment provides the above advantages of eliminating the possibility of invalid measurements by doing away with the necessity of manual data entry.
[0168] Although the invention has been described herein with reference to certain preferred embodiments, one skilled in the art will readily appreciate that other applications may be substituted for those set forth herein without departing from the spirit and scope of the present invention. Accordingly, the invention should only be limited by the claims included below.
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A method and apparatus for calibrating noninvasive or implantable glucose analyzers uses either alternative invasive glucose determinations or noninvasive glucose determinations for calibrating noninvasive or implantable glucose analyzers. Use of an alternative invasive or noninvasive glucose determination in the calibration allows minimization of errors due to sampling methodology, and spatial and temporal variations that are built into the calibration model. An additional embodiment uses statistical correlations between noninvasive and alternative invasive glucose determinations and traditional invasive glucose determinations to adjust noninvasive or alternative invasive glucose concentrations to traditional invasive glucose concentrations. The invention provides a means for calibrating on the basis of glucose determinations that reflect the matrix observed and the variable measured by the analyzer more closely. A glucose analyzer couples an invasive fingerstick meter to a noninvasive glucose analyzer for calibration, validation, adaptation, and safety check of the calibration model embodied in the noninvasive analyzer.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of application Ser. No. 08/676,493, filed Jul. 8, 1996, now abandoned, and continuation-in-part of application Ser. No. 09/002,807, filed Jan. 5, 1998, now abandoned, and continuation-in-part of application Ser. No. 09/389,697 filed Sep. 3, 1999.
FIELD OF THE INVENTION
[0002] This invention is related to the field of prefabricated, modular panel construction as applied primarily to architecture. It relates particularly to a method of construction by which a plurality of panels of various shapes and sizes can be assembled in ways that are capable of producing architectural spaces for a diversity of functional applications and aesthetic expressions. What distinguishes this invention from other related modular construction systems is the extent to which it is able to achieve the above objective in terms of complexity, variety, flexibility as well as efficiency and economy.
BACKGROUND OF THE INVENTION
[0003] Prefabricated and modular panel construction is emerging in response to the high cost of conventional construction. This high cost results from the vast number of materials, weather factors and field labor time involved. One response to dealing with these factors has been to prefabricate all, or portions, of buildings to be shipped for placement or assembly on the site. Mobile homes, houses built in two parts (side by sides), modules or sections for larger assemblages are examples of attempts to lower construction costs. Another method entails prefabricating most all the components of a given design in the factory, forming a kit of parts, to be assembled on the site. Log home kits, steel and pole building systems typify this approach. Both of these approaches are simply attempts at streamlining the production of buildings through standardization, assembly line fabrication methods and reducing field labor time. Far from being modular, these building systems essentially replicate conventional field construction, which, with the above-mentioned shortcuts, result in buildings that may be more cost effective, but typically repetitious and expressionless. Design latitude is sacrificed for construction economy, further hampered by transportation restrictions.
[0004] Truer to the idea of “modular”, prefabricated construction, although less common, are building types based on forms like the sphere; i.e., geodesic dome, regular or semi-regular polyhedra such as the tetrahedron, octahedron and others. The disadvantage of using these forms as space enclosing envelopes for architectural applications is their total inability to be modified in manners of shape, proportions and volume to accommodate varying functional requirements. A given polyhedron can be repeated to form a larger aggregate, useful for bridges, space frame platforms, etc., but not enlarged or reduced to various proportional sizes and joined without customized transition linkages. In addition, the curvature of a geodesic dome, or the profusion of angled surfaces inherent in polyhedral forms, result in spaces that are difficult to subdivide and tend to yield many non-functional dead spaces.
[0005] Regardless, systems employing factory-made panels that can be assembled on site still offer the greatest potential for achieving low cost, functional, diverse and aesthetically interesting architecture. The greatest obstacles to achieving this potential in present art, however, appear to be two-fold. First is the tendency for proposed building systems to rely on or employ derivations of regular or semi-regular polyhedra or the sphere. Developing architecture based on these forms is inherently impeded by the limitations described above. The second obstacle is the issue of joinery. To achieve truly diverse and flexible design capabilities, the problem of connecting prefabricated architecture panels to each other or joining a multiplicity of panels in many and unpredictable combinations has not been successfully solved. The many systems described in prior art are all successful to a degree, but not capable of achieving the total flexibility and applicability sought by the present invention herein described.
[0006] The most common system in use today employs structural members, usually metal tubes called struts, joined at each end by a connector, called nodes, which link like struts converging from different angles together at a point, called the vertice. Together they form a structural framework to which panels are attached, usually to one side or the other of planes defined by strut perimeters. This feature alone automatically limits the number and configuration of panels that can be joined about any given node. However, an even greater obstacle to flexibility is the difficulty in designing a node capable of anchoring struts from very many angles. Beyond a limited number, less than 10 , the node for connecting the struts becomes excessively massive and complicated. This is not only impractical, but unfeasible, for achieving the hundreds of strut angle combinations required for successful realization of capabilities or objectives established by the proposed invention.
[0007] Another approach to the issue of panel joinery is edge splicing, where panels are joined continuously along their sides. This is applicable only for a few panels about any given axis that must also be impractically thin.
[0008] The approach which the present invention is most closely associated with is the common hinge. Hinges have been in use for centuries and their many variations and adaptations have accommodated many applications, including some architectural. The hinge consists essentially of two flanges with attached barrel loops on one side, each attached to a separate panel. The barrel loops of each flange, offset with respect to each other, are then aligned an axis between panels, through which a solid rod or pin is inserted effecting the joinery of the two panels. Several additional panels may also be added, requiring only a longer axis pin to pass through all the barrels. The problem with the application of the hinge, per se, is that it is always a pair designed for two panels; whether three, four or five panels are joined, the hinges function as pairs.
[0009] This implies the need for pre-planning each joint and careful alignment, as the barrel loops of each flange anticipate the position of its mate on the adjoining panel. As with edge splicing, problems with hinged connections become complicated with increasing panel thickness. Panels so joined are, as is the case with the present invention, rotational with respect to the axis about which they are joined; in themselves, there is no provision for fixing the angle between panels. This system must rely entirely on a configuration with other panels to fix a panel's orientation within the assemblage. Also, hinges are designed expressly for use with panels. They are not envisioned or designed for struts that span between vertices. Neither does the application of hinges for panel joinery specifically address the vertice condition, important for achieving practical applications in architecture.
[0010] Therefore, in light of the preceding discussion and of current art, a comprehensive solution for the creation of architectural structures and spaces that are practical, flexible, and diverse in aesthetic expressions as well as technically and economically feasible, is viewed as still outstanding. It is this comprehensive solution which this invention, along with additional embodiments and advantages herein described, was conceived to address.
SUMMARY OF THE INVENTION
[0011] There are two major aspects that constitute the embodiment of the present invention herein described. The first aspect involves a geometric derivation approach that provides a special selection of panel shapes and sizes. Related to each other through a common format, these shapes can be combined in an incalculable number of configurations for the creation of structural frameworks and architectural spaces. Combining these many different shapes in so many different ways requires a connection system that is flexible, versatile and yet practical. This is particularly challenging wherein architectural applications entail panels of considerable thickness. It is this issue, that of joining a large number of different shape and size panels of architectural thickness, that is addressed by the second aspect of the invention.
[0012] To begin with the first aspect, the system for determining panel shapes derives from a three-dimensional grid based on a single, large “primary” cube comprised of twenty-seven smaller “subcubes.” Just as a large square can be divided into many smaller, proportional “sub-squares,” for example nine, a large cube can be divided into many smaller “subcubes,” which in the case of the present invention is twenty-seven. Common to both a two dimensional square and a three dimensional cube is the fact that the lines which define them are always of equal length and always meet at 90 degrees, making them uniquely symmetrical and interchangeable. In the present invention, the large or “primary” cube is envisioned as a three dimensional grid that reveals the twenty-seven cubes that comprise it. The points where the lines of this grid intersect are called vertices, more commonly thought of as where the corners of cubes or squares meet. To obtain an assortment of panel shapes useful for a building system, lines connecting three and four vertices within the twenty-seven cube grid are drawn in all possible combinations to form two dimensional planes. This process produces an assortment of fifty-nine plane shapes, which include three squares, twenty-one rectangles, twenty-four right triangles, nine isosceles triangles and two irregular triangles. In turn, combining these shapes in all possible ways produces sixty-one three dimensional, simple polygons, which include three cubes, three tetragonal primitives, three orthorhombic primitives, nine isosceles prisms, nine right triangular prisms, eleven trirectangular tetrahedrons and fourteen right square pyramids (eight of which occur in both left and right-handed forms).
[0013] This process, that of breaking a simple cube by means of an interior grid into sixty-one polyhedral forms using the integral fifty-nine plane shapes is that which has been termed the “Fractionalized Cube.” It describes the creation of the aforementioned panel shapes and polyhedrons as smaller two and three-dimensional subdivisions or “fractions” of the original cube. Although the fifty-nine plane shapes (hereafter called panels), can be used to construct polyhedrons, fabrication of polyhedral forms is not the primary intent for application of the present invention. Polygons comprised of Fractionalized Cube panels will, similar to other polygons, will have a certain usefulness as single entitles, or more often, in repetitious sequences to form structural frameworks like bridges, towers, space frame platforms, and so on. More importantly, as a result of the variety of their shapes, sizes and proportions, the fifty-nine fractionalized cube panel shapes are intended primarily for architectural applications in the creation of aesthetic, structural and functional architectural spaces.
[0014] Two dimensional squares and rectangles along with three dimensional cubes, tetragonal and orthorhombic primitives, which represent the most prevalent forms found in conventional construction and architecture, occur readily within the fractionalized cube grid. They are also the most common and useful for architectural solutions and space planning. They provide floor areas, wall areas and room volumes that are the most efficient and functional for the incorporation of furnishings and arrangements which can accommodate almost limitless occupancy requirements. This contrasts significantly with architectural designs based on polyhedral forms like tetrahedrons, icosahedrons, dodecahedrons, etc., where the predominance of angled surfaces and space inflexibility make functional adaptations, and installation of furnishings difficult and impractical.
[0015] An important aspect of the Fractionalized Cube is that being the common denominator for fifty-nine panel shapes constitutes a format, which inventory of shapes can literally serve or function as a design tool. The facility for which these shapes can be manipulated and assembled enables a designer to literally sculpt and create architectural forms using these shapes as a medium. The architectonic discipline inherent in employing such related shapes will result in designs that display a natural logic and consistency in any given assemblage, providing an important, built-in advantage in the development of architectural solutions.
[0016] The generation of an inventory of panel shapes as based on the Fractionalized Cube in the present invention is not limited to, or by, this particular grid. It was selected, or preferred, because of the reasonable number of useful panels whose variety of shapes and sizes seemed most appropriate for architectural applications.
[0017] Although simple in concept, the generation of an inventory of panel shapes based on such a three dimensional grid for the purpose of architectural design has not heretofore been employed.
[0018] A major reason a prefabricated panel construction system with shapes based on a three dimensional grid such as the Fractionalized Cube has not been produced is due to the extraordinary difficulty in creating a node (joint connector located at vertices) capable of accommodating the vast number and combinations of strut angles, or angle of panel corners that must converge at any given vertice. To assemble panels whose shapes are derived from the fractionalized twenty-seven subcube grid, a node at any given vertice would have to be designed to accommodate struts converging at that point from an incalculable number of combinations of 290 strut angles. Also, a panel joinery system would need to be able to accommodate planes converging on axes parallel to struts from any combination 341 dihedral angles. These criteria far exceed the capabilities of conventional strut-node assembly systems. In actuality, any given node would need to be capable of receiving struts from all the vertices of not just one twenty-seven subcube volume, which represents only one quadrant of the node, but eight. In other words, such a node would need to be capable of linking struts between itself and all the vertices defining a much larger cube made up of 216 subcubes in order to be truly functional for application of Fractionalized Cube geometries sought with this invention.
[0019] Therefore, in light of this demanding criteria, in addition to those described in Background of the Invention, it is clear that the conventional strut-node structural framing system for carrying panels is not feasible for assembling panels derived from the Fractionalized Cube inventory, as intended. Neither, however, is a mere adaptation and application of hinges, as typically conceived, capable of achieving above described joinery requirements; although the approach to be described in the present invention is more closely associated with the hinge idea.
[0020] In order to make possible the joining of the above described plurality of panel shapes and sizes in such a plurality of unpredictable combinations, especially those of architectural thickness, it is important to first understand the fundamental difference between strut-node and hinged approaches and their distinction from the present invention. The familiar strut-node system consists of struts that are directly and symmetrically centered on axes between vertices, anchored at each end by physical connection devices, called nodes, centered on these vertices. The hinge consists of two planes parallel to the axis between vertices that are joined by means of a solid rod or pin passing through overlapping loop extensions of these two planes called flanges. In construction, it is these flanges that are attached to the panels being joined in an assembly. Typically, however, struts are not joined to each other using hinges. Hinges are primarily for panels. It should also be emphasized that increased panel thickness correspondingly increases the difficulty of employing hinges as a means of panel joinery, greatly limiting versatility.
[0021] To make possible the freedom of assembly required for realizing Fractionalized Cube designs, important variations on and modifications to the hinge approach are required. First of all, struts as framing members are paramount, whether they be independent or an integral part of panels. Panels are to be centered within the frames defined by struts; that is, the centerline of panel thickness passes through the centerline of the struts in line with the axis between vertices, versus attached to the top or bottom of struts. This facilitates varying numbers of panel bearing struts to occur adjacent, parallel to and rotational about a given axis. This makes the incorporation of more panels and the means for joining them to each other much simpler than is possible with framing systems that rely on a single strut centered on an axis. In addition, no predesigned physical node is required at the vertices. The node is essentially replaced by a hub, which is a structural assemblage created by connecting the corner elements of panels—of only those panels being joined to each other - in the immediate proximity of the vertices.
[0022] In other words, a hundred different panel combinations, with respect to a given vertice, would result in a hundred different hub configurations anchoring panels to each other about that point, without the need for nodes, custom modifications or design variations of that element. This goes beyond the joinery capabilities at the vertice condition of all other joinery systems, or methods, knowledgeable to Applicant. It is these two important factors: (1) struts that are offset, parallel to and rotational about the axis between vertices and (2) the elimination of a predesigned physical node at the vertices, which completely liberates the format for architectural space-forming by allowing two or more planes of varying shape and size to be joined at theoretically any angle through 359 degrees around any given axis, and any combination of axes 359 degrees about any given vertice from all directions, providing unparalleled versatility for creating architectural assemblages.
[0023] To achieve joinery of two or more planes about a common axis at a multitude of angles with respect to each other as described above, a joinery detail is required that is capable of doing what a hinge does, but with greater flexibility, which provides objects and advantages not possible with the common hinge or variations thereof The mechanism for joining architecturally scaled panels based on the Fractionalized Cube panel inventory requires two distinct but related joinery assemblies. One joinery assembly type is required at the corners of panels or where formed by two struts on the same plane referred to as a first joinery assembly. A second joinery assembly is preferred along the sides of panels. Both joinery assemblies are comprised of only a few simple components, efficient and economical to both produce and assemble.
[0024] Common to both joinery assemblies is first, the strut. Struts are structural members which may be independent elements, or incorporated into and define the perimeter of panels whose loads, in turn, they bear. Said struts are offset from, parallel to and rotational about the axis between any two vertices and panels being joined. A second component is a cylindrical (tubular) element which is centered on the axis between any two vertices and panels being joined and is referred to as the “centerline element”. Compared to a common hinge, this element replaces the rod, or pin, use to link together its two flanges. The third component common to both the first and second joinery assemblies is one which forms a bridge between the strut-panels edges and the centerline element. Although similar in their bridging function, the design, orientation and application method of this component is quite different between the first and second joinery assemblies. The first joinery assembly is employed at panel comers. It is designed to join with like assemblies at the corners of other panels meeting at the same vertice to create a structural hub about that, or any, given vertice common to said panels. At the panel corner location, this “bridge” element consists of a structural planer member that is horizontal with and parallel to the axis between vertices, i.e., strut-panel sides, and is referred to as a “web”.
[0025] In the second joinery assembly, employed along the sides of panels, the bridge element is also a structural planer member. However, here it is anchored perpendicularly with respect to the axis between vertices and strut-panel sides. This is to accommodate and exploit the panel's thickness in order to achieve a structurally stronger tie between panels, and to provide for locking the dihedral angle between panels in order to prevent their rotation about the axis with respect to each other. This bridge element in the second joinery assembly is referred to as a “bracket”. In addition to its role in joining panels about a common axis, the bracket affords the additional advantage of providing a means for attaching closure membranes for concealing the joint cavities and associated components. These “joint closures” are primarily a matter of architectural detail and not part of the invention described herein.
[0026] Other differences between the bridging element of the first and second joinery assemblies are that with the first joinery assembly, the “web” is either an integral part of, or anchored permanently to, the panel side on the centerline of its thickness. The “bracket” of the second joinery assembly would be a separate element for adjustable positioning along the panel's side, to which it is then anchored. Fastening these web and bracket bridge elements to the tubular “centerline elements” is accomplished by two different means. With the first joinery assembly, independent elements called “collars” are utilized. These elements are analogous to the barrel loops of the common hinge. With the hinge, these loops are integrally formed as part of, or extension of, the flange. In case of the present invention, however, this loop is a separate, detached element, permitting it to be positioned in various numbers and locations along the web. This eliminates the need for predetermining and prepositioning this particularly important connection element, contrary to as required with the more familiar hinge designs. The loop portion of these collars wrap around the tubular centerline element in a manner similar to a stove clamp. Two flat tabs extending from one side of the collar loop is designed to grip the web element to which it is simply bolted, completing the strut-panel side to centerline element connection.
[0027] The bracket of the second joinery assembly, being perpendicular to the axis between vertices, therefore perpendicular to the centerline element, allows this element to be so designed that it self-wraps around and clamps to the tubular centerline element. The brackets of one panel are then simply abutted and bolted to the brackets of adjoining panels, effecting panel to panel joinery. This bolting together of brackets of adjoining panels also effectively locks the position or angle of the panels with respect to each other. This occurs because, in a plane perpendicular to panel sides, a triangulation of three anchorages, strut-panel side, centerline element and bolts, occurs, preventing rotation, or any movement, of panels with respect to each other. Additional bolts simply reinforce this triangulation to stiffen the joint.
[0028] This is not the case, however, at the first joinery assembly where only two anchorages occur, at the strut-panel side and centerline element. This is not important, however, where resistance to this rotation is already accounted for with the second joinery assembly brackets, and because this joinery method is only to be used at the vertice condition, where rotation is automatically resisted through triangulation formed by adjoining panels.
[0029] Further objects and advantages of the first and second joinery assemblies result from the utilization of open-ended cylinders on axes centerlines, the elimination of the physical node (obstruction), at the vertices, and sequence of elements between adjoining strut-panel sides which create a space between the sides of adjoining panels. Together, these features provide an ideal location for the placement of electrical wiring, junction and outlet boxes, TV, telephone and computer cables, interior plumbing and vacuum lines, vents, and so on. These features would provide great economy in construction, as these so-formed joint cavities naturally provide frequent and continuous chases throughout any given structure. This makes it possible to easily install utilities and service lines after the prefabricated panels for a building structure are assembled. This means wall, roof and floor panels can be prefabricated on an assembly line without the complications of anticipating and prepositioning these utilities in the panels in the factory, or cutting and placing them into the panels on the building site; both standard and costly procedures in building practice today. Service lines and utilities so installed in joint cavities would then be enclosed and concealed by means of the joint closures referred to above.
[0030] Another important advantage and objective of the first and second joinery assemblies is also made possible by the tubular centerline element. This key component of the joinery assembly provides for easy transition to other construction systems such as the more typical hub-strut space frame systems or conventional construction. The basic simplicity in attaching joint components collars to webs and brackets to each other—results in structures that are easy to both assemble and disassemble. This means that architecture employing Fractionalized Cube panels can easily be altered, reconfigured, added to or subtracted from with virtually equal facility. This contrasts dramatically with conventional construction, where building revisions entail painstaking and time-consuming destruction and reconstruction.
[0031] An additional related advantage and objective of this invention comes as a result of being a modular panel system with inherent prefabrication accuracies, along with panels whose integral and separate joinery components are self-aligning. In practice, these features dispense with the frequent measuring, cutting and fitting, etc., typical in conventional construction. Design changes, either during the drawing phase or on the site, would easily be accomplished through substitution of panels whose field installation would be facilitated by their independence from utilities and use of simple connection components and methods.
[0032] The above outlines the primary embodiments, objects and advantages of the invention—the Fractionalized Cube Modular Construction System, which is further described in the figures and drawings of the Brief and Detailed Descriptions of the Invention.
BRIEF DESCRIPTION OF THE DRAWING
[0033] FIGS. 1 A- 7 E, show the derivation of a modular construction format, consisting of an inventory of panel shapes based on a subdivided cube grid, labeled the Fractionalized Cube. The complexities posed by this format, particularly relating to the issue of joinery are illustrated in FIGS. 8 and 9. A conceptual framework for solving the issue of joinery is shown in FIGS. 10 A- 10 E and 11 A- 11 D. This is followed by FIGS. 12 - 23 , which illustrate the design approach for two types of joinery assemblies that accomplish the means for mechanically fastening building panels to each other in a manner that solves the criteria of versatility and complexity posed in FIGS. 8 and 9. FIGS. 24 A- 24 B demonstrate research actually employing one of the joint assembly designs, and FIGS. 25, 26 and 27 illustrate an architectural design based on the present invention, to illustrate the capabilities for producing architecture using the Fractionalized Cube Modular Construction System.
[0034] [0034]FIG. 1A shows a square.
[0035] [0035]FIG. 1B shows a square divided into 9 sub-squares.
[0036] [0036]FIG. 1C illustrates a cube with implied subdivision into 27 subcubes.
[0037] FIGS. 2 A- 2 E shows an inventory of 59 panel shapes.
[0038] [0038]FIG. 3 shows 10 simple polygons based on square and rectangular planes drawn on the Fractionalized Cube grid.
[0039] [0039]FIG. 4 shows 18 polygonal prisms defined within the Fractionalized Cube grid.
[0040] [0040]FIG. 5 shows 22 right square pyramid polygons defined within the Fractionalized Cube grid.
[0041] [0041]FIG. 6 shows 11 trirectangular tetrahedron polygons defined within the Fractionalized Cube grid.
[0042] FIGS. 7 A- 7 E represent research studies in space forming and structure based on the panel inventory shown in FIGS. 2 A- 2 E.
[0043] [0043]FIG. 8 shows a diagram illustrating how panels are rotational about axes between vertices.
[0044] [0044]FIG. 9 shows a schematic illustrating radians converging at a vertice common to all eight primary cubes.
[0045] FIGS. 10 A- 10 B illustrates a typical prior art approach to space framing, where connecting nodes are centered on vertices and struts are centered on the axes between vertices.
[0046] FIGS. 10 C- 10 D shows prior art options for attaching panels to struts.
[0047] [0047]FIG. 10E shows, with prior art, how only a limited number of struts can be attached to a node at the vertice condition.
[0048] FIGS. 11 A- 11 B illustrates two fundamental features of the invention; the offsetting of struts from the axes and the absence of a node at the vertice.
[0049] [0049]FIG. 11C shows, in the present invention, attachment of panels to struts which allows for more struts and panels to be positioned in more dihedral combinations than is possible in prior art systems as shown in FIGS. 10 C- 10 D.
[0050] [0050]FIG. 11D shows, in the present invention, how corners of panel-strut assemblies do not meet at or occupy the vertice location.
[0051] [0051]FIG. 12 schematically illustrates three basic elements common to first and second joinery assemblies.
[0052] [0052]FIG. 13 schematically illustrates two additional elements which, when added to the basic components of FIG. 12, comprise the first joinery assembly.
[0053] [0053]FIG. 14 shows how the components of the first joinery assembly are assembled.
[0054] [0054]FIG. 15 schematically illustrates the elements which comprise the second joinery assembly.
[0055] [0055]FIG. 16 shows how the components of the second joinery assembly are assembled.
[0056] [0056]FIG. 17 shows the basic elements of an architectural panel for application of the Fractionalized Cube modular construction system.
[0057] [0057]FIG. 18 illustrates typical joining of two panels per FIG. 17, employing the first and second joinery assemblies.
[0058] [0058]FIG. 19 illustrates the joining of 5 panels, with respect to a common vertice, employing the first joinery assembly elements.
[0059] [0059]FIG. 20 shows how the first joinery assembly can join and alternate with the typical strut-node framing system.
[0060] [0060]FIG. 21 shows how the first joinery assembly may be anchored to conventional construction.
[0061] [0061]FIG. 22 schematically illustrates an assembly of the principal and accessory components of the first joinery assembly, as may be employed in actual construction.
[0062] [0062]FIG. 23 schematically illustrates an assembly of the principal and accessory components of the second joinery assembly, as may be employed in actual construction.
[0063] FIGS. 24 A- 24 B shows two views of an abstract structure built to research the feasibility of the Fractionalized Cube modular construction system, using the first joinery assembly method.
[0064] [0064]FIG. 25 shows a first floor plan design for a residence based on the Fractionalized Cube modular construction system of the present invention.
[0065] [0065]FIG. 26 shows the first floor plan of FIG. 25 laid out in terms of planes derived from the 59 panel inventory shown in FIGS. 2 A- 2 E.
[0066] [0066]FIG. 27 shows a perspective view of a house design, with floor plans shown in FIGS. 25 and 26.
DETAILED DESCRIPTION OF THE INVENTION
[0067] [0067]FIG. 1A shows a square 10 with four equal sides 12 drawn with four equal length lines.
[0068] [0068]FIG. 1B shows primary square 20 comprised of the square 10 of FIG. 1A, whose sides 12 are divided into three equal lengths, which, when connected at right angles, divide square 20 into nine equal subsquares 14 . Lines forming square sides 12 and lines 16 delineating the subsquares 14 , intersect at points called “vertices” 18 .
[0069] [0069]FIG. 1C illustrates the subdivided square 20 , FIG. 1B, extended into three dimensions to create a cube 22 , comprising lines 12 and 16 , connecting all the vertices 18 , of the nine subsquares 14 , FIG. 1B, at right angles across the six faces of the subdivided square 20 , creating twenty-seven subcubes 24 . The lines 16 , defining these subcubes 24 , and points at which these lines intersect, called vertices 18 , constitutes a three dimensional grid which provides the basic format of the Fractionalized Cube, fundamental to the present invention. In this view, most interior grid lines are omitted for clarity.
[0070] FIGS. 2 A- 2 E shows an inventory of fifty-nine panel shapes derived from the three dimensional grid subdividing cube 22 , FIG. 1C, by connecting, in two dimensions, all the vertices 18 of subcubes 24 , in all possible combinations. These panel shapes, when combined in all possible ways, define sixty-one three dimensional simple polygons, illustrated in FIGS. 3, 4, 5 and 6 .
[0071] [0071]FIG. 2A shows three squares 26 and three rectangles 28 that can be used to make simple orthorhombic, tetragonal primitive and cube polygons.
[0072] [0072]FIG. 2B shows six right triangles 30 that comprise the sides of right triangular prisms and the perpendicular sides of right square pyramids and trirectangular tetrahedrons.
[0073] [0073]FIG. 2C shows eighteen rectangles 32 which comprise the hypotenuse planes on isosceles and right triangular pyramids.
[0074] [0074]FIG. 2D shows eighteen right triangles 34 which make up the diagonal faces of right square pyramids.
[0075] [0075]FIG. 2E shows eleven isosceles 36 , and irregular 38 , triangles which make up the diagonal faces of trirectangular tetrahedrons.
[0076] [0076]FIG. 3 shows how three cubes 40 , three tetragonal primitives 42 and four orthorhombic primitives 44 (regular polygons) can be composed from different combinations of subcubes 24 by connecting squares 26 and rectangles 28 from the fifty-nine panel inventory, defined within the Fractionalized Cube grid 22 of FIG. 1C.
[0077] [0077]FIG. 4 shows how nine isosceles 46 and nine right triangular 48 prisms can be formed within this cube grid 22 , using squares 26 , rectangles 28 , 32 and right triangles 30 .
[0078] [0078]FIG. 5 shows fourteen right square pyramids, eight of which occur in both left-hand and right-hand conditions, using squares 26 , rectangles 28 , and right triangles 30 and 34 .
[0079] [0079]FIG. 6 shows ten trirectangular tetrahedrons, one of which occur in both left-hand and right-hand conditions, comprised of three right triangles 30 whose faces are made up of nine isosceles 34 and two irregular 36 triangles. Eight of these forms can be described three ways which can be visualized by rotating each of the three axes x-y-z to the vertical position.
[0080] FIGS. 7 A- 7 E represent five abstract studies with architectural implications, constructed as part of the research into the space forming capabilities of the fifty-nine panel shapes, FIGS. 2 A- 2 E, derived from Fractionalized Cube geometry. FIG. 7E is a composite of FIG. 7A and FIG. 7B with added trestle 49 joining the two.
[0081] [0081]FIG. 8 illustrates the first of two major conditions that need to be addressed if structures are to be assembled with the complexity and versatility demonstrated in FIGS. 7 A- 7 E. This will require that a panel 60 , represented here by planes 56 , or multiple of panels 60 , be capable of being positioned at virtually any angle through 360 degrees about any axis 52 between vertices 18 and dihedral angle 54 , with respect to each other. Here, two planes 56 are shown as rotational about two of only five axes 52 , representing the 145 axes actually required for application of the Fractionalized Cube modular construction system.
[0082] [0082]FIG. 9 shows a cluster of eight cubes, each representing a primary cube 22 comprised of twenty-seven subcubes 24 of FIG. 1C. The node 64 , located at the central vertice 18 of the cluster, shows radians 62 , representing strut angles converging from only twenty-four vertices on a single cube to this centermost vertice 18 (node 64 ) location. These radians represent only a fraction of the 290-strut angles from the vertice 18 intersections of 216-subcubes 24 of all eight primary cubes 22 . This dramatizes the second, most challenging, condition to be addressed by a modular construction system required for the intended application of the Fractionalized Cube panel inventory as illustrated in FIGS. 7 A- 7 E.
[0083] [0083]FIG. 10A schematically illustrates prior art, conventional strut-node, approach to structural and space forming assemblies. Here, a physical node connector 64 is centered on vertices 18 with individual struts 66 , centered on the axis 52 between nodes 64 as illustrated in FIG. 10B. These strut configurations thus define areas 58 for panel 60 infill.
[0084] [0084]FIG. 10C is prior art showing how panels 60 , centered on struts 66 , may be attached, similarly, as shown in FIG. 10D, to the top of struts. These illustrate the limited assembly options and number of panels capable of being attached to any given strut 66 .
[0085] [0085]FIG. 10E is a prior art schematic view of FIG. 10A, joinery condition at vertice 18 , illustrating the problem of anchoring more than just a few struts to any given node-connector 64 , located on said vertice. The more struts, the more massive and complicated the node 64 must be. Space 58 between struts 66 may be infilled to form panels 60 , or panels 60 may lay on top of struts 66 , per FIG. 10D.
[0086] [0086]FIG. 11A schematically illustrates the structural essence of the present invention in contrast to the strut-node framing system FIGS. 10 A- 10 E. This approach literally turns inside out the strut-node system FIGS. 10 A- 10 E. Here, instead of struts 66 and node 64 centered on their respective axes and vertices, struts 66 are offset 67 , parallel to and rotational about the axis 52 between vertices 18 as shown in FIGS. 11 A- 11 B. Also, the physical connecting node 64 as shown in FIGS. 10 A- 10 E, centered on vertices 18 , is eliminated as shown in FIGS. 11 A- 11 D. This space, around vertice locations and around axes between vertices so vacated, makes it possible to position varying numbers of panels 60 in varying combinations about said axes 52 between any two given vertices and about the vertices 18 themselves as shown in FIG. 11D. This freedom to position panels in such a variety of locations with respect to each other about their common axis as shown in FIG. 11C, and vertice as shown in FIG. 11D, is the most essential requisite for a truly comprehensive modular system for prefabricated panel assemblies with sought-after capabilities illustrated in FIGS. 7 A- 7 E.
[0087] To this point it is seen that an inventory of 59 panel shapes FIGS. 2 A- 2 E has been established, based on a 27 subcube grid termed Fractionalized Cube, which can be assembled in multitude of ways to create a great variety of structural shapes and space enclosures. It is also seen that to combine panels with the degree of flexibility illustrated in FIGS. 7 A- 7 E creates immense complications due to the large variety of joinery conditions required to accommodate so many angles of struts and panels about common axes and vertices as defined in FIGS. 8 and 9. It is shown in FIGS. 7 A- 7 E that this is easily accomplished where planes of very little thickness are used. The Fractionalized Cube concept would be little more than a curiosity of no practical use if planes, thickened for architectural applications, could not be joined with the same versatility. The first step in achieving this capability requires, as discussed, removing the struts 66 from axes 52 and the physical node 64 from vertices 18 , as illustrated—FIGS. 11 A- 11 D. This provides many more options for panel-strut combinations about axes and vertices, as compared with the conventional strut-node system. The issue then becomes the nature of the actual physical connection of panels to each other about any given axis or vertice and across the gap between struts or panel sides, as presented in FIGS. 11 A- 11 D, which essential objective of the invention is described in the drawing proceeding.
[0088] [0088]FIG. 12 schematically illustrates three basic components common to the two joinery assemblies embodied in the present invention, and referred to as the first joinery assembly and the second joinery assembly. These fundamental elements include the panel 60 , the strut 66 which carries the panel, and the centerline element 68 , an open-ended cylinder or segment of tubing.
[0089] [0089]FIG. 13 shows an exploded view of the basic elements of the first joinery assembly which shows, in addition to the panel 60 , strut 66 and centerline element 68 of FIG. 12, a “bridge” element—a horizontal planer member, parallel to the panel 60 and strut 66 , called a “web” 70 , and an independent tubular ring, or barrel loop, with tab extensions called a “collar” 50 .
[0090] [0090]FIG. 14 illustrates how the components of the first joinery assembly shown in FIG. 13 are put together. The web 70 , anchored at and parallel to the centerline of the strut 66 (indicated with a slot as shown in FIG. 13) bridges the space between the strut-panel side 66 and the centerline element—tubular segment 68 centered on axes 52 between vertices 18 . The barrel of collar 74 wraps around the centerline element 68 , from which collar rectangular tabs extend above and below the web 70 , to which it is bolted 88 , effectively clamping the centerline element 68 to the web 70 , which in turn is anchored to the strut 66 , carrying panel 60 , completing the linkage.
[0091] [0091]FIG. 15 shows an exploded view of the basic elements of the second joinery assembly, which in addition to the panel 60 , strut 66 and centerline element 68 of FIG. 12, shows a structural planer member that is also a “bridge” element, positioned perpendicular to the panel 60 , strut 66 and centerline element 68 , called a “bracket” 72 .
[0092] [0092]FIG. 16 illustrates how the components, or elements, of the second joinery assembly shown in FIG. 15 are put together. The bracket 72 , anchored perpendicular to the strut 66 and axis 52 , carrying panel 60 , bridges the space between the strut 66 and tubular segment-centerline element 68 centered on axis 52 between vertices 18 .
[0093] [0093]FIG. 17 illustrates the basic elements of a typical architectural panel for application of the Fractionalized Cube Modular Construction System. This consists of area 58 , which may be left open or filled with a variety of architectural materials and treatments forming a panel 60 , struts 66 , three or four of which would define the perimeter and form the panel's sides, webs 70 , a first joinery assembly element located at panel corners, brackets 72 , and a second joinery assembly element located intermediately and intermittently along the panel-strut sides 66 . Webs 70 are fixed at their corner panel-strut locations, whereas brackets 72 are laterally adjustable along the panel-strut 66 sides. Lines 76 , coincident with the axis (axes) 52 , officially define and illustrate the panel's actual perimeter that would be drawn from panel inventory in FIGS. 2 A- 2 E.
[0094] [0094]FIG. 18 illustrates the joining of two typical FIG. 17 panels, incorporating all the elements of the first and second joinery assemblies with respect to axes 52 (coincident with actual panel perimeters 76 ). In addition to elements 60 , 70 and 72 as described in FIG. 17, tubular segment-centerline elements 68 are shown centered on the axis 52 , linking brackets 72 to struts 66 , and webs 70 to each other in relation to vertices 18 , by means of collars 74 .
[0095] [0095]FIG. 19 illustrates in greater detail the function of the first joinery assembly, critical to the application of the invention, which is the formation of a structural hub 78 that surrounds vertice 18 , common to strut-panel assemblies being joined, as opposed to and replacing the physical node connector 64 , centered on a given vertice 18 . This feature provides for the joining of strut-panel corners in the multitude of combinations and directions, as prescribed in FIG. 9, with the versatility required to achieve architectural constructions of the complexity illustrated in the studies of FIGS. 7 A- 7 E. This FIG. shows hub 78 as a structural assemblage that consists of the first joinery assembly elements at the corners of five panels, anchored to each other as described in FIG. 14, about a common vertice. In addition to providing anchorage for strut-panel corners, the elimination of a physical node obstruction allows for continuity of the utility chase feature throughout the joints of Fractionalized Cube panel assemblages. In this view, panels 60 are omitted.
[0096] [0096]FIG. 20 illustrates a further object and advantage of the invention as a feature of the first joinery assembly, FIG. 15, because of its ability and facility for joining, or alternating, with the more typical strut-node space framing and related systems as shown in FIGS. 10 A- 10 E. Here, a physical node 64 is positioned at the vertice 18 from which truncated struts 66 , or dowels 80 , extend to pass through the tubular centerline element 68 , which in turn is attached to the webs 70 of a Fractionalized Cube panel by means of collars 74 . In this case, the centerline elements 68 act as sleeves, providing a simple means for anchoring struts 66 from a conventional strut-node frame.
[0097] [0097]FIG. 21 shows how, similarly, the first joinery assembly components facilitate joinery with conventional construction. In this case, the centerline elements 68 , acting as sleeves, receive dowels 80 that are anchored to a steel plate 82 which in turn is fastened to concrete 84 with anchor bolts 86 . This represents just one of many options for connections with conventional construction materials possible with the joinery systems of the present invention.
[0098] [0098]FIG. 22 shows a schematic architectural detail illustrating the joining of two panels using the components of the first joinery assembly and how such a joint might appear in actual construction. The primary elements, consisting of panels 60 , struts 66 , webs 70 , centerline element 68 and collars 74 , are joined about a common axis 52 . Other elements, such as joint closures 90 concealing the joint mechanism and utilities cavity, are indicated as well as related components, such as bracing 92 and attachment hardware 88 , representing thru-bolts, screws or other fasteners as required.
[0099] [0099]FIG. 23 shows a schematic architectural detail illustrating how the components of the second joinery assembly might appear in actual construction. Assembled in accordance with FIG. 16, the drawing shows, in addition to the principal elements of panel 60 , struts 66 , brackets 72 which bridge between struts 66 and the centerline element 68 , various supplemental or accessory components required to complete a joint assembly. These include joint closures 90 , brace elements 92 , and fastening elements 88 , as required. It can be seen how fastening elements 88 , which bolt the two brackets to each other around the centerline element 68 , prevents movement or rotation of the struts and corresponding panels with respect to each other, effectively fixing the dihedral angle between panels.
[0100] [0100]FIG. 24A shows one view of an abstract structure built as part of the research into the construction feasibility of utilizing Fractionalized Cube panels and joinery methods in accordance with criteria sought in the present invention. The structure is comprised of 49 panels derived form the inventory of panel shapes FIGS. 2 A- 2 E, selected as representative of the total range of panel shapes and sizes, from largest to smallest, and incorporating the severest angles. This structure, based on a 48×48×48 primary cube, utilizes the first joinery assembly exclusively, which components include struts 66 which define panel shapes 58 , tubular centerline elements 68 , collars 74 and webs 70 which bridge between the struts 66 and centerline tubular segments 68 . The panel-shape open space 58 is the area defined by the struts that may be infilled with a wide variety of materials to form solid panels 60 . Hub configurations 78 , formed with the first joinery assembly elements, are evident about all 30-vertices incorporated in the structure. The opposite side of this same structure FIG. 24B further illustrates the versatility with which forms can be generated employing Fractionalized Cube geometry and joinery methods.
[0101] [0101]FIG. 25 shows the first floor plan of a residence designed to illustrate the primary objective and advantage of the present invention, the Fractionalized Cube Modular Construction System. It illustrates the capability of creating structures which embody practical, structural, functional and aesthetic characteristics and qualities required in architectural applications. This design successfully realized specific program requirements and objectives based entirely on the inventory of panel shapes FIGS. 2 A- 2 E derived from the Fractionalized Cube shown in FIG. 1C.
[0102] [0102]FIG. 26 shows the first floor plan of the residence described in FIG. 25, laid out in the form of planes 56 , selected from the 59 panel inventory of FIGS. 2 A- 2 E.
[0103] [0103]FIG. 27 shows a perspective view of building design, which plans are described in FIG. 25 and FIG. 26. Features to be noted are solid and glazed, wall and roof panels 60 , handrails 94 , entrance canopy 96 , angle bay window feature 98 , in addition to the incorporation of decks 100 and planters 102 , all of which illustrate the capabilities and design potential in the Fractionalized Cube Modular Construction System of the present invention.
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This invention pertains to a panelized modular construction system which employs a variety of square, rectangular and triangular panel shapes related to each other, being derived from a common grid subdivided cube. Combining these shapes of thickness practical for architectural application, these panels must be capable of being joined in many different angles and combinations along their sides, and in an unlimited combinations of angles at their corners. This construction system eliminates the strut and node framework typically found in many modular structures based on the geometry of various polyhedral forms. Located in the space between the sides of panels being joined, are simple connecting elements, independent of the panels, employed so as to join panels to each other in a manner that easily accommodate varying numbers and dihedral angles through almost 360 degrees. At the corners, the same versatility is achieved through a variation of the independent connecting element configurations, which allow panel comers to be joined in a manner that creates a structural hub, replacing the node connector typically found in prior art construction systems.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to memory media and input/output device packages. Typically, the package holds a printed circuit board, where the device conforms to the standards set by PCMCIA, JEDIC, ISO, and etc. for peripheral devices.
DISCUSSION OF THE BACKGROUND
[0002] The current trend in the computing hardware, telecommunications and electronics industries is to miniaturize components and devices and to place as many of the components and devices next to each other so as to provide quality technical performance in a small package. Such packages have typically been formed from steel with plastic molded frames. Such packages do not provide a rigid, robust, and precise datum surface upon which a precision assembly may be manufactured. Certain PC card, compact flash or small form factor cards are needed that provide a rigid, accurate structure support for applications such as mini disk drives. The current steel covers with plastic molded frames do not provide enough torsional resistance to external forces, for instance, for such precision PC card applications, LCD displays, hinges, security devices, personal digital assistants (PDA), digitization of analog information scanners, internet connections, and other wireless communication applications. Also, traditional molding methods result in too much shrinkage, thus forming surfaces not having accurate dimensions. Therefore, it is desired to provide the manufacture of components such as PC cards using materials and compounds that may provide an accurate datum plane due to accurately manufactured parts which are stiff and strong.
[0003] Current packages also include hardware that conveys electricity, such as a wire or printed circuit board (PCB), radiates electromagnetic radiation. The hardware is also susceptible to electromagnetic radiation radiated from other sources. The electromagnetic radiation effects the hardware by corrupting or altering the electrical signal that the component conveys. Such corruption of an electrical signal in a component is not tolerable. The power and associated affect of the electromagnetic radiation field diminishes with distance from the source of the electromagnetic radiation. Therefore, the closely placed electronic components and devices disadvantageously influence each other by radiating electromagnetic fields. Placement of electronic components and devices in close proximity to each other would be acceptable if the effects of the electromagnetic radiation emanating from each device could be muted or lessened to a degree where the electromagnetic radiation emanating from each device does not corrupt the electrical signals being conveyed by other components or devices.
[0004] Prior art PCMCIA cards typically have two sheet metal covers which are joined together by a plastic frame molded around each cover, as disclosed in U.S. Pat. No. 5,397,857. U.S. Pat. No. 5,397,857 is hereby incorporated herein by reference. The electrically conductive, sheet metal of the top and bottom covers provide a shielding effect against the transmission of electromagnetic radiation through the top and bottom covers. A seam is formed where the top cover and the bottom cover meet. Due to undulations or unevenness of the sheet metal near the edges of the covers near the seams, some electromagnetic radiation may be able to pass through the region of the seam covered only by plastic material which is, in its natural state, electrically nonconductive, where the plastic material does not provide a shielding effect against electromagnetic radiation, whether the electromagnetic radiation is radiated from components within the PCMCIA card or whether the radiation is radiated from other components external to the PCMCIA card and passes through the seam and into the interior of the PCMCIA card. Such leakage issues are also present in compact flash packages, miniature cards, and other PC card packages, where the term PC card package is inclusive of any package which can contain electrical components, such as the devices described above, and is not to be limited by any narrow definition of the term as used in trade groups.
[0005] Other prior art packages employ a clip or veneer of conductive material positioned around the side edges of the package so as to shield against electromagnetic radiation. Another prior art solution, such as U.S. Pat. Nos. 5,505,628 and 5,476,387, employ the use of covers that have mechanical overlaps which attach one cover to the other cover at discrete intervals along the side edge of the package. The mechanical overlaps electrically ground the two covers to each other. The mechanical overlaps traverse or cross over the side edge of the package, as such, only intermittent shielding is provided, which not acceptable. Such solutions, however, add to the size, complexity, material cost, and labor cost of the package.
[0006] Thus, there is a need for a simple to manufacture and assemble package that shields the seam of the device package from electromagnetic radiation.
SUMMARY OF THE INVENTION
[0007] It is an object of the invention to provide a peripheral device package that meets PCMCIA, JEDIC, Compact Flash Association (CFA), and ISO standards. It is a further object of the present invention to provide a package holding a printed circuit board which has a rigid accurate datum on which to build a product on and also reduces the strength of the electromagnetic field emanating from the package and at the same time reduces the influence of electromagnetic radiation, from other sources, on the printed circuit board held within the package.
[0008] It is also an object of the present invention to provide a PC card package formed from materials that provide an accurate rigid datum for applications that require precision assemblies.
[0009] In one form of the invention the device package takes the form of first and second electrically conductive covers, where each cover has a perimeter. A first electrically conductive frame is attached to the first electrically conductive cover along a portion of the perimeter of the first electrically conductive cover and a second electrically conductive frame is attached to the second electrically conductive cover along a portion of the perimeter of the second electrically conductive cover. The first and second electrically conductive frames are then attached to each other so as to form an electrical connection between the first and second electrically conductive frames. The first and second electrically conductive covers are then secured to each other via the electrically conductive first and second frames. Thus, forming an electrical connection between the first and second electrically conductive covers.
[0010] In yet another form of the invention, the invention is a method of assembling the inventive apparatus described above. The inventive method includes the steps of injection molding a first material around a portion of the perimeter of the first electrically conductive cover so as to form the first electrically conductive frame attached to the perimeter of the first electrically conductive cover, where the first electrically conductive cover is electrically connected to the first electrically conductive frame. Likewise, another step includes the injection molding of a second material to form the second electrically conductive frame attached to the second electrically conductive cover in a manner similar to that described in regard to the first electrically conductive cover and frame. Then the two sub-assemblies of an integrated cover and frame are brought together, where the first and second electrically conductive frames are bonded to each other so as to form an electrical connection between each of the parts.
[0011] Another embodiment of the method to form a part having a stiff structure thus forming a datum surface. An accurate datum surface is critical to the performance of the component mounted thereto and to the overall performance of the entire package. The method including the steps of placing a metallic material into a molding machine, converting the metallic material to a thixotropic state; transferring the metallic material in the thixotropic state to a mold, where the mold has a portion of an object either fully or partially inserted into the mold; changing state of the metallic material in the thixotropic state to a solid state while being in the mold so as to form the part; and removing the part from the mold, the part having the object bonded thereto.
[0012] Thus, Applicants' invention is superior to the prior art. Applicants' invention provides a device package that prevents or lessens the strength of an electromagnetic field passing through the seam of the device, as well as preventing or lessening the strength of the electromagnetic field passing through the covers of the device package, while decreasing the part count and providing an easy to assemble package. Therefore, Applicants' invention achieves the desired objectives. The prior art fails to disclose a PCB carrying package that shields the PCB from electromagnetic radiation both through the cover and the frame of the package where a portion of the frame of the package is exposed to the environment along the seam, which provides the desired result. Such structural features distinguish Applicants' invention, structurally and functionally, over the prior art of U.S. Pat. No. 5,397,857.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
[0014] [0014]FIG. 1 is a perspective view of the first cover of the package;
[0015] [0015]FIG. 2 is a cross-sectional view taken along section line 1 - 1 of FIG. 1;
[0016] [0016]FIG. 3 is a cross-sectional view taken along section line 2 - 2 of FIG. 1;
[0017] [0017]FIG. 4 is a cross-sectional view taken along section line 3 - 3 of FIG. 1;
[0018] [0018]FIG. 5 is a cross-sectional view taken along section line 4 - 4 of FIG. 1;
[0019] [0019]FIG. 6 is a perspective view of the second cover of the package;
[0020] [0020]FIG. 7 is a cross-sectional view taken along section line 1 - 1 of FIG. 6;
[0021] [0021]FIG. 8 is a cross-sectional view taken along section line 2 - 2 of FIG. 6;
[0022] [0022]FIG. 9 is a cross-sectional view taken along section line 3 - 3 of FIG. 6;
[0023] [0023]FIG. 10 is a cross-sectional view taken along section line 4 - 4 of FIG. 6;
[0024] [0024]FIG. 11 is a cross-sectional view taken along a side edge location of the assembled package including a memory card secured within the package;
[0025] [0025]FIG. 12 is a schematic view of a thixomolding set-up;
[0026] [0026]FIG. 13 is a perspective view of a mold having a first element therein and a second element partially therein; and
[0027] [0027]FIG. 14 is a perspective view of a molded part.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, and more particularly to FIGS. 1 - 11 thereof, a first embodiment of the present invention is a PCMCIA style peripheral device package 10 displayed therein. FIG. 1 is a perspective view of a first cover 12 and a first frame 16 assembled together forming a first half 11 of the package 10 which displays the interior of the first half 11 . Additionally, raised portions or ridges 18 and pits 20 are shown which fit with complimentary features on a second half 30 (see FIG. 6) of the package 10 to which the first half 11 is attached at the final stage of manufacture. The first cover 12 has a perimeter 13 . Along portions of the perimeter 13 of the first cover 12 are distributed fingers 26 . The first cover 12 and the first frame 16 are constructed of an electrically conductive material. The first cover 12 can be constructed of an electrically conductive, stamped, sheet metal material, or any other suitable electrically conductive material. The first frame 16 can be constructed of an electrically conductive plastic material such as grades A230 or B230 of VECTRA liquid crystal polymer produced by the Advanced Materials Group of the Hoechst Celanese Corporation, or any other suitable electrically conductive material.
[0029] [0029]FIG. 2 is a cross-sectional view taken along section line 1 - 1 of FIG. 1. FIG. 2 displays part of the connection of the first cover 12 to the first frame 16 . FIG. 2 shows further details of the ridges 18 and pits 20 of the first frame 16 . FIG. 3 is a cross-sectional view taken along section line 2 - 2 of FIG. 1. FIG. 3 shows details of the connection between the first frame 16 and the first cover 12 , and the ridge 18 . FIG. 4 is a cross-sectional view taken along section line 3 - 3 of FIG. 1. FIG. 4 shows details of the connection between the first cover 12 and the first frame 16 and how the first cover 12 wraps around the first frame 16 . FIG. 4 also shows details of the embedding of fingers 26 into the first frame 16 . FIG. 5 is a cross-sectional view taken along line 4 - 4 of FIG. 1. FIG. 5 shows an example of the intermittent spacing of fingers 26 by way of the absence of fingers 26 at the present cross-section. In order to facilitate bonding, portions of the top cover perimeter 13 are bent to conform to the shape of the top frame 16 . Additionally, in a preferred embodiment the fingers 26 become embedded in the top and bottom frames 16 and 18 during the bonding and/or molding process to form an integral frame-cover element which is the first half 11 of the package 10 . The top cover 12 being wrapped around the top frame 16 also serves to strengthen the package 10 . However, having multiple fingers 26 is not required by the present invention and any portion of the cover such as an edge of the cover embedded in the plastic frame may provide a strong and secure package.
[0030] FIGS. 6 - 10 display the second half 30 of the package 10 that mates with the first half 11 previously discussed. FIG. 6 is a perspective view of the second half 30 which includes a second cover 32 and a second frame 36 . The second cover includes perimeter portions 33 and finger 46 along portions of the perimeter 33 . The second frame 36 includes recess 38 and plugs 40 . The recesses 38 and plugs 40 are dimensioned so as to conform to and mate with the ridges 18 and pits 20 of the first half 11 . FIG. 7 is a cross-sectional view taken along line 7 - 7 of FIG. 6. FIG. 7 displays a portion of the connection between the second cover 32 and the second frame 36 along a portion of the perimeter 33 of the second cover 32 . FIG. 7 also displays a cross-sectional shape of the recess 38 . FIG. 8 is a cross-sectional view taken along line 8 - 8 of FIG. 6. FIG. 8 displays the embedding of a portion of the perimeter of the second cover 32 into the second frame 36 . Further shown in FIG. 8 is the recess 38 . FIG. 9 is a cross-sectional view taken along line 9 - 9 of FIG. 6. FIG. 9 displays the fingers 46 along the perimeter 33 of the second cover 32 being embedded in the second frame 36 . Also shown in FIG. 9 is the recess 38 . FIG. 10 is a cross-sectional view taken along line 10 - 10 of FIG. 6. FIG. 10 displays a portion of the perimeter 33 of the second cover 32 in a location where fingers 46 are not present, as compared to FIG. 9. Except for two differences, the shape and materials of construction of the second half 30 are the same as that used for the first half 11 . The two difference between the fist half 11 and the second half 30 of the package 10 are as follows: the first half 11 has ridges 18 and pits 20 , where, in there place, the second half 30 has recesses 38 and plugs 40 .
[0031] The manufacture of the PCMCIA style peripheral device package 10 is accomplished as follows (reference will be made only to the first half 11 of the package 10 when the manufacturing steps are also identical for the second half 30 of the package 10 ): first, the first cover 12 is stamped. The first frame 16 is then formed to the first cover 12 . This is accomplished by an injection molding process. The first cover 12 is placed into a mold, where it is secured into position. The securing of the first cover 12 is accomplished by the geometry and dimensions of the first cover 12 . The first cover 12 is stamped to be slightly wider than the mold. Thus, the first cover 12 is slightly sprung when it is placed into the mold, and remain in the proper position for the injection molding process. Certainly, there is no requirement that the first cover 12 be secured in the mold as described above. Any means of securing will suffice. The same manufacturing steps are employed to attach the second cover 32 to the second frame 36 .
[0032] The conductive plastic which forms the first frame 16 is then shot into the mold. As the conductive plastic first frame 16 is molded, portions of edges of the cover 12 such as the metal fingers 26 of the first cover 12 become embedded in the first frame 16 so that separation of the first cover 12 from the first frame 16 cannot take place. However, as discussed above, the first frame 16 can be made of other electrically conductive material. The same manufacturing steps are employed to attach the second cover 32 to the second frame 36 .
[0033] Once both the first half 11 and the second half 30 of the package 10 have been made, the first frame 16 of the first half is positioned so as to face and contact the bottom frame 36 of the second half 30 . The ridges 18 and pits 20 of the first half 11 mesh with the complimentary recesses 38 and plugs 40 of the second half 30 . The assembly is then subjected to a sonic welding process. As a result of the sonic welding process, the first frame 16 is bonded to the second frame 36 . FIG. 11 is a cross-sectional view of the assembled package 10 where the cross-section is taken along a section line (similar to lines 3 - 3 or 4 - 4 ) going through a side edge of the package 10 . FIG. 11 displays the printed circuit board (PCB) 28 positioned between the first half 11 and the second half 30 . Also shown are the fingers 26 of the first cover 12 and the fingers 46 of the second cover 32 . FIG. 11 also shows a seam 118 which is present between the first half 11 and the second half 30 after assembly. The seam 118 is the pathway through which unacceptable levels of electromagnetic radiation would enter the package 10 and exit the package 10 if the first frame 16 and the second frame 36 were not made of an electrically conductive material. The welded conductive plastic frames 16 and 36 form a permanent bond which encases the PCB 28 . However, the gap shown between the covers 12 and 32 near the seam 118 does not necessarily extend around the entire circumference of the package 10 . As discussed earlier, undulation or unevenness exist at the edge of the covers 12 and 32 . Therefore, even though gaps may exist at discrete locations, at other locations the covers 12 and 32 may be contacting one another and as such provide sufficient shielding at that location.
[0034] Thus, the first and second covers 12 and 32 are secured to the respective first and second frames 16 and 36 , where the frames 16 and 36 are welded to each other. This ensures that the first cover 12 is electrically connected to the first frame 16 , and that the first frame 16 is electrically connected to the second frame 36 , and that the second frame 36 is electrically connected to the second cover 32 . Thus, the first cover 12 is electrically connected to the second cover 32 . Therefore, the PCB 28 is shielded from electromagnetic fields located outside of the package 10 even in the region of the seam 118 located between the first and second halves 11 and 30 . Additionally, electromagnetic fields generated by the PCB 28 are substantially contained within the package 10 .
[0035] Furthermore, the assembly process ensures that the memory card package 10 will be very reliable and durable. It should be noted, that the bonding process between the elements of the package 10 may be performed by resistance welding.
[0036] Additionally, one of the frames such as frame 16 which has the ridges 18 can be formed of conductive plastic and the frame 36 which has the grooves 38 can be formed of nonconductive plastic as long as the length of the ridges 18 is long enough so when the two covers are assembled, the ridges 18 extend past the edge of the cover 32 so as to prevent RFI/EMI leakage through the seam 118 . A grounding clip (not shown) can be placed inside the package so as to make electrical connection between the two covers.
[0037] As a further option, the electrically conductive material of the first and second frames can be a metallic material. In such a situation, similar to the explanation above, the first cover is positioned in a mold or die into which the metallic material is die cast. As the metallic material flows into the mold, it surrounds portions of edges of the frame such as the fingers of the first cover so as to form the first frame. Upon solidification of the metallic material, the integrated first cover and first frame assembly form a first half of the package. The first cover is then in electrical contact with the first frame. The same procedure applies to the second cover and second frame of the second half. The remaining assembly procedures are the same as discussed above in regard to the first and second frames constructed of plastic material.
[0038] As good as die casting is to produce complicated shapes having a quality surface finish, die casting, typically, suffers from the ill effects of entrained air. Thus, comprimising the structural integrity of the die cast part. Furthermore, the grain structure of the material is not refined, thus lowering the strength of the die cast part.
[0039] A preferred method of forming metallic frames, covers, and datum surfaces is by way of the thixomolding process. The thixomolding process is a way to mold thixotropic materials such as aluminum, magnesium, and zinc, and is a tradename of Thixomat Inc. of Ann Arbor, Mich. Parts formed by this process have material properties which are between those of parts formed by forging and parts formed by die casting. However, forged parts are more expensive, due to the high price of forging molds. Thixomolding is explained in U.S. Pat. Nos. 5,711366; 5,819,839; 5,836,372; 5,878,804; 4,964,455 all of which are hereby incorporated herein by reference.
[0040] Due to the ability of metallic thixotropic materials to become more liquid when sheared, similar to a polymer, these materials can be formed with machinery that is more like the injection molding machinery used for polymers instead of the die-casting methods traditionally used for molding metallic materials. Unlike die casting where metal is first put into a molten state, in the thixomolding process metal pellets are transferred into the thixomolding machine. As the pellets travel through the machine they are heated and sheared by an auger so as to place the pellets in a semi-solid, thixotropic state forming a slurry. The slurry is then injected into the mold, where the mold has been pre-sprayed with a mold-release agent as is well known in the art. As such, the use of thixotropic materials allow for high speed injection molding of the thixotropic materials much like a polymer. Like a polymer, the material in the thixotropic state are able to be molded into wall thicknesses which are thinner than can be achieved with die cast metals. Additionally, the solidified thixotropic material has mechanical material properties that exceed those of most typical polymers. Furthermore, since the material is placed into the mold while the material is in the thixotropic state the material is more dense than it would be if it were die cast. Thus, the thixotropic material minimizes the voids and shrinkage that accompanies most die cast parts. Such a material results in an end product which is stronger than it otherwise would be.
[0041] Once in the metallic material is in the thixotropic state, thirty or forty percent of the mass is in the liquid phase and the remaining portion is in the solid phase. The solid portion typically has small spherically-shaped nodules suspended within the liquid phase. Semisolid metals heated to a thixotropic state exhibit unique Theological properties due to their non-dendritic, or spherical microstructure. By heating the metals to a semisolid range and then agitating the semisolid alloy, the dendritic microstructure normally found is eliminated and replaced by the spherical microstructure. Upon solidification, the metal exhibits a fine equiaxed microstructure. The grain structure of the of the semisolid-formed metal is an intermediate sized grain structure which is larger than forged grain structure and smaller than cast grain structures.
[0042] Thus, for example viewing FIGS. 1 - 11 , the frames 16 and 36 can be formed by flowing thixotropic material around edges of the cover such as the fingers 26 of the covers 12 and 32 . The resulting parts created from the thixomolding process has as-molded dimensions which when compared to the dimensions of the mold itself are nearly identical, and come closer to matching the mold dimensions than does nearly any other process. Furthermore, the frame is stiffer than a frame constructed of a conductive plastic material, and, also, provides for shielding against EMI/RFI. The stiff, strong structure provides for a robust part which is dimensionally stable when subject to external forces. Thus, the part can be used as a datum surface since it is so dimensionally accurate.
[0043] In the electronics industry, for example, a miniature, 340-MB hard drive that is the size of a large coin is designed to fit within a CompactFlash Type II package, as described in U.S. patent application Ser. No. 09/169,124, which is hereby incorporated herein by reference. The housing member of such a package must have a surface which is planar and flat within exacting tolerance bands so as to properly mount the miniature hard drive. Furthermore, the entire structure must be stiff so as to maintain the accurate dimensions. Such a structure ensures the continued performance of the miniature hard drive.
[0044] Thus, thixotropic materials, via the thixomolding process, are able to form parts having thin wall portions, and the dimensions of the parts are able to be held to close tolerances. The metallic material provides superior shielding along with high mechanical material properties such as stiffness.
[0045] [0045]FIG. 12 is a schematic view of the thixomolding process. FIG. 12 shows a material 50 which will be put into the thixotropic state, a thixomolding machine 52 and a mold 54 .
[0046] [0046]FIG. 13 is a perspective view of the mold 54 having a first half 55 and a second half 56 . The second half 56 is shown as having a first object or element 57 positioned inside the second half 56 of the mold 54 and a second object or element 59 positioned partially within the second half 56 of the mold 54 . The second half 56 of the mold 54 has a cut-out in its side wall for receiving the second object 59 . Such molding is known as insert molding, which is similar to that described above in regard to the covers 12 and 36 .
[0047] [0047]FIG. 14 is a perspective view of a molded part 58 created by the thixomolding process. The molded part 58 has a body 60 and the second object 59 sticking out from the body 60 . The first object 57 is not seen in FIG. 14 since it is covered by the solidified thixotropic material of the body 60 .
[0048] The objects inserted into the mold are presently metallic materials. However, it is envisioned that the objects can be constructed of ceramic, plastic, mineral, or other inorganic or organic substances. The mold is made of materials known to those skilled in the art.
[0049] The embodiment discussed above in regard to FIGS. 12 - 14 is representative of the insert molding capabilities of such a process. It is envisioned that this process can be used to manufacture reinforced components. Such components are needed in many industries, including the telecommunications industry. As an example, a hinge connecting the body of a hand-held, portable phone to the receiver is in need of being very small, yet having high strength and high stiffness so as to be robust.
[0050] It is also envisioned that the molded part 58 can later be used as an object that is placed fully or partially in another mold, in a secondary molding procedure, where other material is formed around the part 58 so as to construct more complicated, composite parts. As such, the molded part 58 can be molded first and then later plastic components, such as a plastic cover, can be overmolded onto the part such as a PC card metallic frame during a later step.
[0051] It is further envisioned that any of the edges of the first half 11 and the second half 30 of the package 10 such as shown in FIGS. 1 - 11 can have an opening or notch so as to accommodate a connector for an I/O device.
[0052] Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
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A PCB package for shielding electromagnetic radiation from exiting or entering the package. In one embodiment the package includes first and second electrically conductive covers and first and second electrically conductive frames. The first frame electrically connected to the first cover and the second frame electrically connected to the second cover. The first frame is then electrically connected to the second frame. The first and second frames can be made of electrically conductive plastics or metals or any other electrically conductive materials. Methods of assembling the packages of the various embodiments are also set forth.
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TECHNICAL FIELD
[0001] The present invention relates to a self-healing laminated structure and a self-fusing insulated wire.
BACKGROUND ART
[0002] In preparation for recent environmental problems, for example, prevention of global warming and reduction and recycling of waste, the products with less environmental burden are increasingly used. More specifically, as seen in the application of naturally-derived materials and the recycling of PET bottles, efforts to the reduction of environmental burden from the entry to the exit of products have been made. In such flow of products, from the viewpoint of using a product, it goes without saying that lifetime improvement of the products leads to a reduction of environmental burden.
[0003] Towards lifetime improvement of products, for example, seeing resin materials, there is also a method to improve the strength of the resin material itself, and also a method to provide a resin material with a self-healing property. As a latter method, as seen in PTL 1, a method of encapsulating a self-healing agent and embedding the self-healing agent in a resin material has been known, and lifetime improvement of the resin materials is sought.
CITATION LIST
Patent Literature
[0004] PTL 1: JP 7-40491 A
SUMMARY OF INVENTION
Technical Problem
[0005] Incidentally, in the self-healing laminated structure using a capsule described above, there are disadvantages that the capsule containing a healing material is expensive, and also that the process of dispersing the capsule is also required, thus there are many practical problems. In addition, the subject of the self-healing is also limited to delamination in a fiber reinforced plastic, based on its healing process and the size of the capsule.
[0006] It is thought that the range of application of resin material products that require lifetime improvement, particularly, electric product using a resin material, is widespread. A familiar example is a response to self-healing of general cracks such as cracks on the surface of electric product on which a resin material is applied. In addition, in electric product using winding wire, an example is a response to self-healing of cracks in a self-fusing insulated wire used in electric product in severe usage environment.
[0007] Specifically, crack generation by an electric transformer and vibration of a rotary motor is a major problem such that leads directly to product lifetime. It is considered that the applicable resin material products are widespread, such as electronic equipment such as a cell phone, electric product such as a refrigerator and a washing machine, furthermore, a drive motor such as automobile, and wind power generator, thus, needs of a self-healing resin material are big.
[0008] An object of the invention is to provide a laminated structure excellent in self-healing property that can be prepared by a cheap and simple method, and to provide a self-fusing insulated wire using the same and electric product using the electric insulated wire.
[0009] The novel characteristics of the invention will be apparent from the description of the present specification and the accompanying drawings.
Solution to Problem
[0010] The present invention provides a self-healing laminated structure in which a self-healing resin layer is formed on a base material and a thermosetting resin top coat is formed on an outer layer thereof, wherein the self-healing resin layer includes an uncured cross-linkable or curable thermoplastic resin, and the thermosetting resin top coat includes a cross-linking agent, curing agent or curing catalyst of the cross-linkable thermoplastic resin.
[0011] Further, the present invention provides the self-fusing insulated wire in which a self-healing resin layer is formed on a conductor and an uncured self-fusing thermosetting resin top coat is formed on an outer layer thereof, wherein the self-healing resin layer includes an uncured cross-linkable or curable thermoplastic resin, and the thermosetting resin top coat includes a cross-linking agent, curing agent or curing catalyst of the cross-linkable thermoplastic resin.
Advantageous Effects of Invention
[0012] According to the invention, a laminated structure excellent in self-healing property that can be prepared by a cheap and simple method can be provided, and a self-fusing insulated wire using the same and electric product can be provided.
BRIEF DESCRIPTION OF DRAWINGS
[0013] FIG. 1 is a cross-sectional view illustrating an example of a self-healing laminated structure according to the invention.
[0014] FIG. 2 is a cross-sectional view illustrating another example of a self-healing laminated structure according to the invention.
[0015] FIG. 3 is a cross-sectional view illustrating an example of a self-fusing insulated wire according to the invention.
[0016] FIG. 4 is a cross-sectional view illustrating a comparative example of a laminated structure according to the invention.
[0017] FIG. 5 is a cross-sectional view illustrating a comparative example of a self-fusing insulated wire according to the invention.
[0018] FIG. 6A is a cross-sectional view describing self-healing of a laminated structure according to the invention and the comparative example.
[0019] FIG. 6B is a cross-sectional view describing self-healing of a laminated structure according to the comparative example.
[0020] FIG. 6C is a cross-sectional view describing self-healing of a laminated structure according to the invention.
[0021] FIG. 7A is a cross-sectional view describing self-healing of a laminated structure according to the invention.
[0022] FIG. 7B is a cross-sectional view describing self-healing of a laminated structure according to the invention.
DESCRIPTION OF EMBODIMENTS
[0023] Hereinbelow, the invention will be described in detail along with embodiments (Examples) with reference to the drawings. FIG. 1 is a schematic view for describing an outline constitution of the self-healing laminated structure according to the invention. A self-healing resin layer 3 is provided on a base material 1 , and a thermosetting resin layer 2 (top coat) is provided on an upper layer thereof. FIG. 4 is a laminated structure when there is no self-healing resin layer shown herein. The thicknesses of the self-healing resin layer 3 and the thermosetting resin layer 2 formed on the upper layer thereof are each preferably 10 to 100 μm.
[0024] FIG. 2 is a schematic view for describing an outline constitution of the self-healing laminated structure according to the invention. The self-healing resin layer 3 is provided on the base material 1 , and the thermosetting resin layer 2 is provided on an upper layer thereof. Furthermore, a barrier layer 4 is provided between the self-healing resin layer and the thermosetting resin layer.
[0025] FIG. 3 is an illustration of an outline constitution of a self-fusing insulated wire using the self-healing laminated structure according to the invention. An insulation film layer 6 is formed on a conductor 5 , furthermore, the self-healing resin layer 3 is provided on an upper layer thereof, and the thermosetting resin layer 2 is provided on an upper layer thereof. FIG. 5 is a self-fusing insulated wire when there is no self-healing resin layer shown herein.
[0026] The material of the base material according to the invention is not particularly limited so long as it is a solid such as plastic, glass, metal or ceramics. In addition, the material may be a base material in which these materials are mixed. A shape of the base material according to the invention is not also particularly limited so long as it can be coated with a laminated structure such as a planar, linear, block or spherical shape.
[0027] The thermosetting resin used in the thermosetting resin layer according to the invention includes epoxy resins, phenoxy resins, acrylate resins, phenol resins, melamine resins, thermosetting polyimide, and the like. Among them, phenoxy resins are preferable as a thermosetting resin for a self-fusing insulated wire. Among phenoxy resins, bisphenol A and bisphenol S phenoxy resins are particularly preferable. The thermosetting resin layer (top coat) according to the invention may contain a curing agent, cross-linking agent or curing catalyst for a self-healing resin layer, in addition to a thermosetting resin and a curing agent or curing catalyst thereof. This curing agent, cross-linking agent or curing catalyst is used in curing of the self-healing resin of the self-healing resin layer in a lower layer thereof. When the self-healing layer contains two components or more, a curing agent, cross-linking agent or curing catalyst that reacts with one or more components thereof is previously added to the thermosetting resin layer. The amount of the curing agent, cross-linking agent or curing catalyst added is 10 parts by weight or less based on the thermosetting resin layer.
[0028] As the self-healing resin used in the self-healing resin layer according to the invention, any resin that shows flowability at high temperature like thermoplastic resins can be used. The self-healing resin includes butyral resins, phenoxy resins, and polyamide resins. The phenoxy resins include bisphenol A and bisphenol S phenoxy resins. The thermoplastic resins in which an epoxy resin is added to these phenoxy resins are also acceptable. In the polyamide resins, various nylon resins are usable. This self-healing resin shows flowability under heating, flows in the defects generated in the thermosetting resin layer in the upper layer thereof, and cures by reacting with the curing agent, cross-linking agent or curing catalyst contained in the thermosetting resin layer, to heal the thermosetting resin layer.
[0029] The barrier layer according to the invention is provided for the purpose of suppressing the diffusion of the curing agent of the thermosetting resin layer into the self-healing resin layer, for example, at ordinary temperature or low temperature (for example, 100° C. or lower).
[0030] Any material is acceptable so long as it suppresses diffusion of the curing agent. Since a curing agent generally has large polarity, non-polar material incompatible therewith is particularly preferable. The barrier layer includes polyethylene resins, polypropylene resins, polystyrene resins and the like. When a surfactant such as polyethylene glycol or polyvinyl alcohol in preparation of the self-healing resin layer is used, a barrier layer is voluntarily formed. The thickness of the barrier layer is preferably 1 to 5 μm. This thickness is a thickness that can be coated by one application process.
[0031] When the self-healing resin layer contains an epoxy resin, amine catalysts, acid anhydrides, imidazole and the like can be used as the curing agent according to the invention. When the self-healing resin layer is a phenoxy resin, latent curing agents and the like can be used. The amine-catalyst includes meta-xylene diamine, trimethyl hexamethylene diamine and the like, and the imidazole includes 2-phenyl imidazole, diazabicyclo-undecene and the like. The acid anhydride includes tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and the like. The latent curing agent includes blocked isocyanates, aromatic sulfonium salts, and the like. The former is converted to a curing agent by heat, and the latter is converted to a curing agent by light.
[0032] The self-fusing insulated wire according to the invention is a self-fusing wire having an insulation film, wherein an enamel layer is provided on the surface of copper wire, and a self-fusing layer is provided on the enamel layer. The enamel layer is formed by applying and calcining a polyester imide varnish or a polyamide imide varnish.
[0033] Examples of the electric equipment in which the self-fusing insulated wire according to the invention is used include electronic equipment such as a cell phone equipped with a speaker voice coil, household electric product such as a refrigerator and washing machine equipped with a household motor such as a compressor motor, furthermore, electric power equipment such as an electric transformer, an industrial motor and rotary motor for wind power generator, and an electric motor for automobile.
[0034] Particularly, in electric power equipment using a winding wire, usage environment is severe, thus there is an urgent need to respond to self-healing of cracks in a self-fusing insulated wire. Specifically, crack generation by an electric transformer and vibration of a rotary motor for power generator is a major problem such that leads directly to product lifetime. Furthermore, these electric power equipment are expected as one of applied fields of self-healing resin materials since service place is not in the environment where operation such as heal can be easily made, such as the mountain zone, oceanic zone, and further, outer space, thus lifetime improvement of the product is most expected.
[0035] Next, specific examples of the self-healing laminated structure according to the invention and the self-fusing insulated wire using the same will be described, but the scope of the invention is not limited to these examples.
Example 1
[0036] A self-healing laminated structure shown in FIG. 1 will be described. As a base material 1 , a glass base material with a size of 20 mm×40 mm and a thickness of 1 mm was used. As a thermosetting resin layer 2 , a bisphenol A epoxy resin (manufactured by Japan Epoxy Resin, grade name “1001”) was used. As a self-healing resin layer 3 , a blended resin of a phenoxy resin (YP-55: manufactured by Tohto Kasei) and a bisphenol A epoxy resin (manufactured by Japan Epoxy Resin, grade name “1001”) was used.
[0037] As a thermosetting resin varnish forming a top coat, a bisphenol A epoxy resin as a main component, methylhexahydrophthalic anhydride (HN-5500, manufactured by Hitachi Chemicals) that was a curing agent, and an imidazole curing catalyst (P-200, manufactured by Japan Epoxy Resin) of a catalyst were used. Seventy-two parts by weight, 26 parts by weight and 2 parts by weight thereof, respectively, were added to tetrahydrofuran to obtain a thermosetting resin varnish with a solid content concentration of 20%.
[0038] As the self-healing resin varnish, a phenoxy resin and a bisphenol A epoxy resin were used. Each 50 parts by weight thereof was added to tetrahydrofuran to obtain a self-healing resin varnish with a solid content concentration of 20%. The imidazole curing catalyst serves as a curing agent of the self-healing resin.
[0039] The glass base material surface was washed with acetone, and after drying, the self-healing resin varnish was applied with a bar coater. The solvent was air-dried at room temperature, and then completely removed at 150° C. over 1 hour, whereby a self-healing resin layer with a film thickness of about 40 μm was prepared.
[0040] The thermosetting resin varnish was applied on the self-healing resin layer prepared above with a bar coater. The solvent was air-dried at room temperature, and then completely removed at 150° C. over 2 hours, and simultaneously the curing reaction of epoxy resin was terminated, whereby a thermosetting resin top coat with a film thickness of about 40 μm was prepared, to obtain a self-healing laminated structure A.
[0041] As a comparative example, a laminated structure including a glass base material 1 and a thermosetting resin layer 2 shown in FIG. 4 was prepared. The thermosetting resin varnish of Example 1 was used for preparing the thermosetting resin layer 2 , to obtain a laminated structure A.
[0042] Against the self-healing laminated structure A and the laminated structure A, a razor manufactured by Feather Safety Razor Co., LTD. (high stainless double edge blade, thickness of 0.1 mm) was vertically pressed on the surface of the laminated structure to make a cut trace 7 on each laminated structure. FIG. 6A shows a schematic view of a cross section of the self-healing laminated structure A after cutting, and FIG. 6B shows a schematic view of a cross section of the laminated structure A after cutting. The conditions of these cut traces 7 can be easily observed under a stereoscopic microscope. Since the base material of these laminated structures is a glass base material, the laminated structures can be observed also under a transmission microscope.
[0043] When these self-healing laminated structure A and laminated structure A after cutting were left at 160° C. for 5 minutes and observed under a stereoscopic microscope, the form in FIG. 6B was almost maintained in the laminated structure A while the interval of right and left cross sections of the cut traces was slightly narrow. On the other hand, in the self-healing laminated structure A, the form was changed to a form where the cut trace of the thermosetting resin layer 2 was embedded with flow of the self-healing resin as shown in FIG. 7A . Naturally, the cut trace of a self-healing resin layer 3 could not be distinguished. It is presumed that imidazole in the thermosetting resin layer served as a cross-linking agent or curing agent of the self-healing resin.
[0044] In the present example, the blended resin of a phenoxy resin and a bisphenol A epoxy resin is used in the self-healing resin layer, and the rate of parts by weight thereof is selected since the blended resin melts flown at 160° C. When the self-healing temperature is set at 160° C. or lower, the part by weight of the epoxy resin should be increased. On the contrary, when the self-healing temperature is set at 160° C. or higher, the part by weight of the phenoxy resin should be increased. These are also a benefit when using a blended resin. Even when a single thermoplastic resin having a fixed melt flow temperature is directly used, a similar self-healing is achieved. For example, when a thermoplastic resin such as a butyral resin or a polyamide resin is used, it is possible to achieve self-healing at a set temperature according to the used thermoplastic resin. As described above, in the self-healing laminated structure of the invention, it is also characterized in that the self-healing temperature can be arbitrarily set.
[0045] In the present example, self-healing of vertical cut on the surface of the self-healing laminated structure has been described, and naturally, it is obvious that it can respond also to the separation between the thermoplastic resin layer and the self-healing resin layer.
[0046] While the resin of the thermosetting resin layer is limited to an epoxy resin in the present example, it is also obvious that similar self-healing effect is obtained even when using the thermosetting resin such as urea resin, melamine resin, phenol resin, and unsaturated polyester resin.
[0047] In addition, it is obvious that the self-healing effect is obtained even when the thermosetting resin layer and the self-healing resin layer contain an additive material such as a glass fiber and an alumina filler, not only resin components.
Example 2
[0048] A self-healing laminated structure shown in FIG. 2 will be described. As a base material 1 , an aluminum base material with a size of 20 mm×40 mm and a thickness of 1 mm was used. As a thermosetting resin layer 2 , a bisphenol A epoxy resin (manufactured by Japan Epoxy Resin, grade name “1001”) was used.
[0049] As a self-healing resin layer 3 , a blended resin of a phenoxy resin (YP-55: manufactured by Tohto Kasei) and a bisphenol A epoxy resin (manufactured by Japan Epoxy Resin, grade name “1001”) was used. As a barrier layer, a cycloolefin polymer resin (manufactured by ZEON CORPORATION, Zeonex 480) was used.
[0050] As a thermosetting resin varnish, a bisphenol A epoxy resin as a main component, methylhexahydrophthalic anhydride (HN-5500, manufactured by Hitachi Chemicals) that was a curing agent, an imidazole curing catalyst (P-200, manufactured by Japan Epoxy Resin) as a catalyst, and a stabilized isocyanate (manufactured by Showa Denko, Karenz MOI-BM) as a curing agent of the self-healing resin were used. Sixty-eight parts by weight, 25 parts by weight, 2 parts by weight and 5 parts by weight thereof, respectively, were added to tetrahydrofuran to obtain a thermosetting resin varnish with a solid content concentration of 20%.
[0051] As the self-healing resin varnish, a phenoxy resin and a bisphenol A epoxy resin were used. Seventy parts by weight and 30 parts by weight thereof, respectively, were added to tetrahydrofuran to obtain a self-healing resin varnish with a solid content concentration of 20%.
[0052] As a varnish for the barrier layer, a cycloolefin polymer resin was added to toluene to obtain a varnish for the barrier layer with a solid content concentration of 5%.
[0053] The aluminum base material surface was washed with acetone, and after drying, the self-healing resin varnish was applied with a bar coater. The solvent was air-dried at room temperature, and then completely removed at 150° C. over 1 hour, whereby a self-healing resin layer with a film thickness of about 40 μm was prepared.
[0054] The varnish for the barrier layer was applied on the self-healing resin layer prepared above with a bar coater. The solvent was air-dried at room temperature, and then completely removed at 150° C. over 1 hour, whereby a barrier layer with a film thickness of about 5 μm was prepared.
[0055] The barrier layer prepared above was irradiated with ultraviolet, then the thermosetting resin varnish was applied on this barrier layer with a bar coater. The ultraviolet was irradiated for improving the adhesion between the barrier layer and the thermosetting resin film. The solvent was air-dried at room temperature, then completely removed at 150° C. over 2 hours, and the curing reaction of epoxy resin was terminated, whereby a thermosetting resin layer with a film thickness of about 40 μm was prepared, to obtain a self-healing laminated structure B.
[0056] As a comparative example, a laminated structure B including an aluminum base material 1 , a self-healing resin layer 3 and a thermosetting resin layer 2 shown in FIG. 1 was prepared. As the self-healing resin layer 3 , the self-healing varnish was used, and as the thermosetting resin layer 2 , the thermosetting resin varnish was used, and since curing of the thermosetting resin varnish was carried out at 180° C. over 4 hours, a stabilized isocyanate to which the thermosetting resin varnish was added was diffused into the self-healing resin varnish, and a phenoxy resin that was a self-healing resin was cured.
[0057] Against the self-healing laminated structure B and the laminated structure B, a razor manufactured by Feather Safety Razor Co., LTD. (high stainless double edge blade, thickness of 0.1 mm) was vertically pressed on the surface of the laminated structure to make a cut trace 7 on each laminated structure. FIG. 6C shows a schematic view of a cross section of the self-healing laminated structure B after cutting, and FIG. 6A shows a schematic view of a cross section of the laminated structure B after cutting. The conditions of these cut traces 7 can be easily observed under a stereoscopic microscope.
[0058] When the self-healing laminated structure B and the laminated structure B after cutting were left at 180° C. for 5 minutes and observed under a stereoscopic microscope, the form in FIG. 6A was almost maintained in the laminated structure B while the interval of right and left cross sections of the cut traces was slightly narrow. It is considered that, this was caused since, in the preparation process of the laminated structure B, curing reaction of the thermosetting resin layer was carried out at 150° C. over 4 hours, whereby a stabilized isocyanate contained in the thermosetting resin was diffused into the self-healing resin layer, a phenoxy resin in the self-healing resin layer was crosslinked and cured by the stabilized isocyanate by leaving at 180° C. for 5 minutes, to deactivate flowability.
[0059] On the other hand, in the self-healing laminated structure B, the form was changed to a form where a cut trace 8 of the thermosetting resin layer 2 was embedded with flow of the self-healing resin as shown in FIG. 7B . However, it was not observed that the self-healing resin flowed to the surface of the thermosetting resin layer. It is presumed that the phenoxy resin was reacted with the stabilized isocyanate contained in the thermosetting resin layer 2 to be cured, to lower flowability.
[0060] In the present example, the blended resin of a phenoxy resin (high molecule) and a bisphenol A epoxy resin (low molecule) is used in the self-healing resin layer, and the rate of parts by weight thereof is selected since the blended resin melts flown at 180° C. When the self-healing temperature is set at 180° C. or higher, the part by weight of the high molecular weight phenoxy resin should be increased. These are also a benefit when using a blended resin. Even when a single thermoplastic resin having a fixed melt flow temperature is directly used, a similar self-healing is achieved. For example, when a thermoplastic resin such as an unsaturated polyester resin or a modified polyamide resin is used, it is possible to achieve a thermoplastic resin at a set temperature according to the used thermoplastic resin.
[0061] In the self-healing laminated structure of the present example, it is characterized in that flow of the self-healing resin penetrates into defects of the thermosetting resin layer (top coat), and is reacted with the curing agent or catalyst present in the thermosetting resin layer in these parts (these are added in excess amounts to the thermosetting resin so as to function as a cross-linking agent or curing agent of the self-healing resin.), to self-heal the defect parts, and also that the flowability of the self-healing resin layer can be adjusted so that the healing part does not protrude from the surface of the thermoplastic resin layer. In addition, a substance that is different from the curing agent or curing catalyst of the thermosetting resin and acts as a curing agent or cross-linking agent of the self-healing resin can be added to the thermosetting resin layer.
[0062] While the resin of the thermosetting resin layer is limited to an epoxy resin in the present example, it is also obvious that similar self-healing effect is obtained even when using the thermosetting resin such as urea resin, melamine resin, phenol resin, and unsaturated polyester resin.
[0063] In addition, it is obvious that the self-healing effect is obtained even when the thermosetting resin layer and the self-healing resin layer contain an additive material such as a glass fiber and an alumina filler, not only resin components.
[0064] In the present example, the barrier layer applied a varnish for the barrier layer obtained by adding a cycloolefin polymer resin to toluene. However, when a cycloolefin polymer resin is dissolved in tetrahydrofuran in preparing a self-healing resin varnish, a cycloolefin polymer is phase-separated on the surface of the self-healing resin layer in preparing a self-healing resin layer. Therefore, a method for voluntarily forming a barrier layer can be also used, and a self-healing effect similar to the present example is obtained.
[0065] Hereinbelow, the combinations of a self-healing resin and a cross-linking agent are shown.
[0066] In the case of an epoxy resin, a stabilized isocyanate can be used (described in Examples).
[0067] In the case of a urea resin (urea resin+hydrazodicarbonamide), a stabilized isocyanate can be used.
[0068] In the case of a melamine resin (melamine resin+hydrazodicarbonamide), a stabilized isocyanate can be used.
[0069] In the case of a phenol resin (a curing agent is not necessary for a resol-type phenol resin), a stabilized isocyanate can be used.
[0070] In the case of an unsaturated polyester resin (unsaturated polyester resin+organic peroxide), a stabilized isocyanate can be used.
[0071] The above cross-linking agent is necessary to be added to the resin composition on which a top coat is to be formed.
Example 3
[0072] A self-fusing insulated wire shown in FIG. 3 will be described. As a base material, a polyamide imide enameled wire was used. The thickness of the polyamide imide film to be an insulation film 6 was 10 μm, and the conductor diameter of a copper wire to be a conductor 5 was φ 0.8 mm. As a thermosetting resin layer 2 , a phenoxy resin (YP-50: manufactured by Tohto Kasei) was used. As a self-healing resin layer 3 , a blended resin of a phenoxy resin (YP-55: manufactured by Tohto Kasei) and a bisphenol A epoxy resin (manufactured by Japan Epoxy Resin, grade name “1001”) was used.
[0073] As a thermosetting resin varnish, a phenoxy resin as a main component and a stabilized isocyanate (manufactured by Showa Denko, Karenz MOI-BP) that was a cross-linking curing agent were used. Eighty parts by weight and 20 parts by weight thereof, respectively, were added to tetrahydrofuran to obtain a thermosetting resin varnish with a solid content concentration of 20%.
[0074] As the self-healing resin varnish, a phenoxy resin and a bisphenol A epoxy resin were used. Eighty parts by weight and 20 parts by weight thereof, respectively, were added to tetrahydrofuran to obtain a self-healing resin varnish with a solid content concentration of 20%.
[0075] The self-healing resin varnish was applied and burned on the polyamide imide enameled wire, whereby a self-healing resin layer with a film thickness of about 30 μm was prepared. Furthermore, the thermosetting resin varnish was applied and burned on the self-healing resin layer, whereby a thermosetting resinous resin layer with a film thickness of about 40 μm was prepared, to obtain a self-fusing insulated wire C.
[0076] Before curing a top coat 2 of the outermost layer of the thermosetting resin, this top coat has a self-fusing property. Moreover, the self-fusing insulated wire was formed into a coil or the like, and then the top coat is fused and cured. Thereafter, a part of the self-healing resin 6 is flown into the defects generated on the top coat under a certain heating temperature, and reacted with a cross-linking agent, curing agent or curing catalyst present in the top coat 2 to heal the defect part and convert to a thermosetting resin.
[0077] As a comparative example, a self-fusing insulated wire D including a polyamide imide enameled wire including a conductor 5 and an insulation film 6 and a thermosetting resin layer 2 shown in FIG. 5 was prepared. The above thermosetting resin varnish was used for preparing a thermosetting resin layer 2 , to obtain a self-fusing insulated wire D.
[0078] In the self-fusing insulated wire C and the self-fusing insulated wire D, cracks were forced to be generated on a thermosetting fusing film provided on the outer periphery of the insulated conductor by bending operation.
[0079] When the self-fusing insulated wire C and self-fusing insulated wire D after generating these cracks were left at 180° C. for 5 minutes and observed under a stereoscopic microscope, in the self-fusing insulated wire D, the cracks could be clearly observed. On the other hand, in the self-fusing insulated wire C, the crack portions were observed in the state of being embedded with flow of the self-healing resin in the self-healing resin layer.
[0080] Although the present example is not a self-fusing insulated wire provided with a barrier layer, as shown in Example 2, when the varnish for the barrier layer with a solid content concentration of 5% obtained by adding a cycloolefin polymer resin to toluene is used, it is possible to cure the self-healing resin at the crack portions and suppress flowing. In this case, a stabilized isocyanate that is a cross-linking curing agent of the phenoxy resin should be added to the thermosetting resin layer in a slightly excessive amount more than equivalence relation.
[0081] In addition, an amine-based curing agent to the bisphenol A epoxy resin may be added to the thermosetting resin layer. It is obvious that both have an effect of curing the self-healing resin at the crack portions and suppressing the flow thereof.
[0082] In the present examples, the blended resin of the phenoxy resin and the bisphenol A epoxy resin are used for the self-healing resin layer, and the rate of parts by weight thereof is selected since the blended resin melts flown at a set temperature. In the self-fusing insulated wire of the invention, it is characterized in that the self-healing temperature can be arbitrarily set. When the blended resin of the phenoxy resin and the bisphenol A epoxy resin melt flown at the operating temperature of the electric product using this self-fusing insulated wire is used, electric product such as an electric transformer that can respond to the crack due to vibration and can respond to lifetime improvement, a motor for power generation, and a drive motor for automobile can be provided.
Example 4
[0083] The self-healing laminated structure shown in FIG. 1 will be described. As a base material 1 , a glass base material with a size of 20 mm×40 mm and a thickness of 1 mm was used. As a thermosetting resin layer 2 , a bisphenol A epoxy resin (manufactured by Japan Epoxy Resin, grade name “1001”) was used. As a self-healing resin layer 3 , a polyvinyl butyral resin (BM-1: manufactured by SEKISUI CHEMICAL CO., LTD.) was used.
[0084] As a thermosetting resin varnish, a bisphenol A epoxy resin as a main component, methylhexahydrophthalic anhydride (HN-5500, manufactured by Hitachi Chemicals) that was a curing agent, an imidazole curing catalyst (P-200, manufactured by Japan Epoxy Resin) as a catalyst, and a stabilized isocyanate (manufactured by Showa Denko, Karenz MOI-BM) as a curing agent of the self-healing resin were used. Sixty-eight parts by weight, 25 parts by weight, 2 parts by weight and 5 parts by weight thereof, respectively, were added to tetrahydrofuran to obtain a thermoplastic resin varnish with a solid content concentration of 20%.
[0085] As the self-healing resin varnish, a polyvinyl butyral resin was used. The polyvinyl butyral resin was added to isopropanol to obtain a self-healing resin varnish with a solid content concentration of 20%.
[0086] The glass base material surface was washed with acetone, and after drying, the self-healing resin varnish was applied with a bar coater. The solvent was air-dried at room temperature, and then completely removed at 80° C. over 1 hour, whereby a self-healing resin layer with a film thickness of about 40 μm was prepared.
[0087] The thermosetting resin varnish was applied on the self-healing resin layer prepared above with a bar coater. The solvent was air-dried at room temperature, and then completely removed at 150° C. over 2 hours, and simultaneously the curing reaction of epoxy resin was terminated, whereby a thermosetting resin layer with a film thickness of about 40 μm was prepared, to obtain a self-healing laminated structure A.
[0088] As a comparative example, a laminated structure including a glass base material 1 and a thermosetting resin layer 2 shown in FIG. 4 was prepared. The thermosetting resin varnish was used for preparing the thermosetting resin layer 2 , to obtain a laminated structure A.
[0089] Against the self-healing laminated structure A and the laminated structure A, a razor manufactured by Feather Safety Razor Co., LTD. (high stainless double edge blade, thickness of 0.1 mm) was vertically pressed on the surface of the laminated structure, to make a cut trace 7 on each laminated structure. FIG. 6A shows a schematic view of a cross section of the self-healing laminated structure A after cutting, and FIG. 6B shows a schematic view of a cross section of the laminated structure A after cutting. The conditions of these cut traces 7 can be easily observed under a stereoscopic microscope. Since the base material of these laminated structures is a glass base material, the laminated structures can be observed also under a transmission microscope.
[0090] When the self-healing laminated structure A and laminated structure A after cutting were left at 100° C. for 5 minutes and observed under a stereoscopic microscope, the form in FIG. 6B was almost maintained in the laminated structure A while the interval of right and left cross sections of the cut traces was slightly narrow. On the other hand, in the self-healing laminated structure A, the form was changed to a form where the cut trace of the thermosetting resin layer 2 was embedded with flow of the self-healing resin as shown in FIG. 7A . Naturally, the cut trace of a self-healing resin layer 3 could not be distinguished.
[0091] In the present example, self-healing of vertical cut on the surface of the self-healing laminated structure has been described, and naturally, it is obvious that it can respond also to the separation between the thermoplastic resin layer and the self-healing resin layer.
[0092] While the resin of the thermosetting resin layer is limited to an epoxy resin in the present example, it is also obvious that similar self-healing effect is obtained even when using the thermosetting resin such as urea resin, melamine resin, phenol resin, and unsaturated polyester resin.
[0093] In addition, it is obvious that the self-healing effect is obtained even when the thermosetting resin layer and the self-healing resin layer contain an additive material such as a glass fiber and an alumina filler, not only resin components.
Example 5
[0094] A self-healing laminated structure shown in FIG. 1 will be described. As a base material 1 , a glass base material with a size of 20 mm×40 mm and a thickness of 1 mm was used. As a thermosetting resin layer 2 , a thermosetting acrylate resin (manufactured by Mitsui Chemicals, Inc.) was used. As a self-healing resin layer 3 , a blended resin of a phenoxy resin (YP-55: manufactured by Tohto Kasei) and a bisphenol A epoxy resin (manufactured by Japan Epoxy Resin, grade name “1001”) was used.
[0095] As a thermosetting resin varnish, a thermosetting acrylate resin as a main component, isophorone diisocyanate (manufactured by Bayer Holding Ltd.) that was a curing agent, and a stabilized isocyanate (manufactured by Showa Denko, Karenz MOI-BM) as a curing agent of the self-healing resin were used. Seventy-two parts by weight, 26 parts by weight and 2 parts by weight thereof, respectively, were added to methyl ethyl ketone to obtain a thermosetting resin varnish with a solid content concentration of 20%.
[0096] As the self-healing resin varnish, a phenoxy resin and a bisphenol A epoxy resin were used. Each 50 parts by weight thereof was added to tetrahydrofuran to obtain a self-healing resin varnish with a solid content concentration of 20%.
[0097] The glass base material surface was washed with acetone, and after drying, the self-healing resin varnish was applied with a bar coater. The solvent was air-dried at room temperature, and then completely removed at 150° C. over 1 hour, whereby a self-healing resin layer with a film thickness of about 40 μm was prepared.
[0098] The thermosetting resin varnish was applied on the self-healing resin layer prepared above with a bar coater. The solvent was air-dried at room temperature, and then completely removed at 120° C. over 1 hour, and simultaneously the curing reaction of acrylate resin was terminated, whereby a thermosetting resin layer with a film thickness of about 40 μm was prepared, to obtain a self-healing laminated structure A.
[0099] As a comparative example, a laminated structure including a glass base material 1 and a thermosetting resin layer 2 shown in FIG. 4 was prepared. The thermosetting resin varnish was used for preparing the thermosetting resin layer 2 , to obtain a laminated structure A.
[0100] Against the self-healing laminated structure A and the laminated structure A, a razor manufactured by Feather Safety Razor Co., LTD. (high stainless blades, thickness of 0.1 mm) was vertically pressed on the surface of the laminated structure, to make a cut trace 7 on each laminated structure. FIG. 6A shows a schematic view of a cross section of the self-healing laminated structure A after cutting, and FIG. 6B shows a schematic view of a cross section of the laminated structure A after cutting. The conditions of these cut traces 7 can be easily observed under a stereoscopic microscope. Since the base material of these laminated structures is a glass base material, the laminated structures can be observed also under a transmission microscope.
[0101] When the self-healing laminated structure A and laminated structure A after cutting were left at 160° C. for 5 minutes and observed under a stereoscopic microscope, the form in FIG. 6B was almost maintained in the laminated structure A while the interval of right and left cross sections of the cut traces was slightly narrow. On the other hand, in the self-healing laminated structure A, the form was changed to a form where the cut trace of the thermosetting resin layer 2 was embedded with flow of the self-healing resin as shown in FIG. 7A . Naturally, the cut trace of a self-healing resin layer 3 could not be distinguished.
[0102] In the present example, self-healing of vertical cut on the surface of the self-healing laminated structure has been described, and naturally, it is obvious that it can respond also to the separation between the thermoplastic resin layer and the self-healing resin layer.
[0103] While isophorone diisocyanate is described as the curing agent of the thermosetting resin layer in the present example, it is also obvious that similar self-healing effect is obtained even when using the curing agent such as tolylene diisocyanate, diphenylmethane diisocyanate, and trimethylhexamethylene diisocyanate.
[0104] In addition, it is obvious that the self-healing effect is obtained even when the thermosetting resin layer and the self-healing resin layer contain an additive material such as a glass fiber and an alumina filler, not only resin components.
[0105] Although the invention has been specifically described based on the above examples, the invention is not limited to the above examples, and it is obvious that various changes may be made without departing from the scope of the invention.
REFERENCE SIGNS LIST
[0000]
1 base material
2 thermosetting resin layer
3 self-healing resin layer
4 barrier layer
5 conductor
6 insulation film
7 crack
8 liquid self-healing resin
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Provided is a laminated structure having excellent self-repairing performance, which can be prepared by an inexpensive and simple method; also provided are a self-bonding insulated wire and electrical machine using the same. A self-repairing laminated structure in which a self-repairing resin layer is formed on a base material and a thermosetting resin topcoat is formed on an outer layer thereof is characterized in that the self-repairing resin layer includes an uncured cross-linkable or curable thermoplastic resin, and the thermosetting resin topcoat includes a cross-linking agent, curing agent, or curing catalyst of the cross-linkable thermoplastic resin.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to engine control devices, and particularly relates to mechanisms designed to remotely control the throttle, shift and emergency stop functions of marine engines.
2. Description of the Prior Art
A number of remote control units for marine engines have been developed in the prior art. The most widely used of these control units include a remote housing and a single control handle. The control handle is connected to the throttle and shift mechanisms of the engine by throttle and shift cables. The control unit also may include electrical switches which are connected to the electrical system of the engine. These remote control units permit operation of only the shift mechanism (forward or reverse) during the first portion of rotation of the control handle and then, during the last portion of rotation, permit control of only the throttle mechanism. Such arrangements are disclosed in the following U.S. Pat. Nos. 3,301,084 to Boda; 3,309,938 to Pervier; and 4,027,555 to Rauchle, et al.
The U.S. patents to Pervier and Rauchle, et al, also describe a "warm up" or "throttle only" button positioned at the base of the control handle. This button disengages the shift mechanism and permits operation of only the throttle mechanism upon rotation of the handle. One disadvantage of such "throttle only" mechanisms is that they utilize a driving key which moves axially to engage or disengage a shift mechanism. This requires an elongated slot which is difficult and costly to manufacture.
One known prior control also includes a neutral lock mechanism. The neutral lock mechanism locks the control handle in a neutral position. Included in the neutral lock mechanism is a release lever or trigger to unlock the control handle. When unlocked, the control handle can be rotated to operate the shift and throttle mechanisms. The problem with this known prior control is that the trigger is on the lower surface of a T-shaped control handle. This position of the trigger is difficult to operate with a natural closing of the hand over the T-shaped control handle. This prior known control also was limited to a vertical position for neutral.
Marine engines have also used a safety stop switch as a separate accessory. A safety stop switch is used to stop the engine in an emergency. One suitable prior safety stop switch used a spring loaded push switch which when depressed permits the engine to operate. A cap is normally positioned on the switch to permit the engine to operate. The cap is connected to the operator so that if the operator is thrown from the control station the lanyard pulls the cap free of the switch causing the engine to stop. The safety stop switch must be continually depressed to allow a passenger to restart and run the engine in order to rescue the operator.
U.S. Pat. Nos. 2,588,650; 2,729,984; 2,826,283; 2,919,772; 2,975,653; 3,023,869; 3,165,941; 3,208,300; 2,702,6l5; 2,737,822; 2,884,109; 2,960,199; 2,986,044; 3,043,159; 3,202,125; 3,143,994; 2,705,485; 2,762,606; 2,907,412; 2,966,969; 2,987,152; 3,127,785; 3,204,732; and 3,160,027 describe prior remote control units for marine engines. These patents describe one method for absorbing unwanted throttle movement during shifting. This is accomplished by a spring attached to a control cable anchor point. When the control handle is moved for shifting, the spring maintains the idle throttle position until the shift motion is completed. Although satisfactory, it is not suitable for a compact design.
SUMMARY OF THE INVENTION
The present invention contemplates a control unit for an engine of the type having a shift means for shifting between forward, neutral, and reverse and throttle means for controlling engine speeds between idle and high speed, the control unit comprising a housing having a control handle rotatably supported by the housing. Shift linkage means and throttle linkage means in the housing are coupled with the engine and are responsive to rotation of the handle to control each of the shift and throttle means of the engine during a portion of the arc of rotation of the handle.
A throttle only shaft extends normal to the handle and through the housing, the control unit further including latch means responsive to axial movement of the throttle only shaft to permit operation of only the throttle means responsive to rotation of the handle. A latch pin biased toward a position engaging the shift means with the handle is provided.
In a preferred embodiment of the present invention, the control unit includes a hollow control shaft extending through the housing with the throttle only shaft extending axially through the control shaft. A shift gear is rotatable with the control shaft for controlling the shifting means and a latching means is provided for disengaging the shifting gear responsive to the axial movement of the throttle only shaft from the first position. In the preferred embodiment, the control shaft includes a hole therein adjacent the shift gear, the shift gear including a slot with a latch pin within the slot, the pin being biased by the radial biasing means through the hole in the control shaft to lock the shift gear to the control shaft. Means are provided for alternately sliding the pin into and out of the hole in the control shaft to permit rotation of the shift gear with the control shaft when the pin is engaged in the hole and permitting rotation of the control shaft without rotation of the shift gear when the pin is not engaged in the hole.
In an alternate embodiment of the present invention, the throttle only shaft is locked in the throttle only position, until such time as a manual force is applied to the throttle only shaft to move the shaft back into the original position in which the shift gear is engaged with the control shaft to permit operation of the shifting function.
The preferred embodiment of the present invention also includes means for absorbing motion between the shift and throttle mechanisms, during the period of rotation of the control handle in which only the shift function is being operated. This is accomplished by employing a biasing spring between the throttle lever and arm, in order to keep the arm tight against the corresponding idle position.
THE DRAWING
FIG. 1 is a front elevation of the control unit incorporating the features of the present invention.
FIG. 2 is a cross sectional side elevation of the unit of FIG. 1, taken along the line 2--2.
FIG. 3 is a cross sectional top view of the unit of FIGS. 1 and 2, taken along the line 3--3 in FIG. 2.
FIG. 4 is a cross sectional top view of an internal portion of the unit of FIG. 1, taken along the line 4--4.
FIG. 5 is a back view of the unit shown in FIG. 1.
FIG. 6 is another back view of the unit of FIG. 1, with a portion of the structure shown in FIG. 5 removed, to more clearly illustrate the bias arrangement provided between the throttle arm and throttle lever.
FIG. 7 is a sectional view of another portion of the unit of FIG. 1, detailing the safety stop switch arrangement.
FIG. 8 is a cross sectional elevation illustrating an alternate embodiment of the "throttle only" control arrangement for the unit of FIGS. 1-7.
FIG. 9 illustrates details associated with the control handle lock mechanism for the unit shown in FIGS. 1-4.
DETAILED DESCRIPTION
Referring to FIGS. 1, 2 and 4, the control unit 10 includes a cover 12 having an internal cast housing 14. A control handle 16 is connected to a control shaft 18 extending through a central hole 20 in the housing 14. A bushing 22 surrounds the control shaft 18 in the central shaft hole 20. A "throttle only" or "warm up" button 24 is positioned at the bottom of the control handle 16, and is attached to a "throttle only" shaft 26. The shaft 26 is biased in an outward direction, as will be described below.
Referring to FIGS. 1, 2 and 3, the control handle 16 includes a hollow tube of generally rectangular cross-section having a crossed hand grip 28 at the top. A trigger 30 is positioned in the forward face of the grip 28, and is pivotally attached at pivot 32. In the operation of the trigger 30, it pivots at 32 to contact a stop 34, formed as an internal surface in the control handle 16.
The trigger 30 includes an aperture 36 and is forced outward by a spring 38 against a stop 40 formed within the grip 28.
As illustrated in FIGS. 2 and 3, the control unit 10 further includes a lock rod 42 having a bent upper end portion 44 retained within the aperture 36 of the trigger 30. As shown at the bottom of FIG. 2 and in detail in FIG. 9, the housing 14 includes a plurality of blind holes 46 positioned in a circular fashion about the central shaft hole 20. A lock ring 48 includes a pair of pins 49 for matching engagement with the holes 46 and slots 50 which engages the lower end of the lock rod 42. The lower end 52 of the lock rod 42 has a compound bend to engage one of the slots 50. The holes 46 in the housing 14 are spaced at equal angular distances about the central shaft hole 20 in the housing 14. In the preferred embodiment the holes 46 are about 30 degrees apart and the slots 50 in the lock ring 48 are offset about 15 degrees with respect to the radial line of the opposing slot. This permits the user to select a preferred neutral control handle position from a group of possible neutral positions. This is accomplished by alternately selecting one or the other slot and rotating the lock ring 48 to different positions with respect to the pins 49 and the holes 46.
Referring again to FIGS. 1, 2 and 3, the disengagement of the lower end 52 of the lock rod 42 can be accomplished by squeezing the trigger 30. This causes rotation of the upper end 44 which also causes the entire length of the lock rod 42 to rotate and disengage the lower end 52 from the slot 50. This causes the control handle 16 to be unlocked from the corresponding neutral position.
As shown in FIGS. 1 and 2, the control handle 16 is provided with a pair of push button switches 60 and 62 which are used to control the tilt of the marine engine in a conventional manner. These switches are surrounded by a lip 64 to prevent accidental operation. Electrical wires 66 extend through the control handle 16 and are connected with associated electrical wires 68 by a non-conductive encasement 70 which is hinged to lock corresponding male and female electrical connections associated with the wires 66 and 68 together. The control unit 10 is further provided with an ignition switch 72 which is operable with an associated key 74. The choke function is operated by axial movement of the key 74 into the switch 72. The key 74 is also encased in a plastic housing 76 having a collar 78. This facilitates movement of the key 74 toward the ignition switch 72.
In FIGS. 4 and 5, a shift gear 80 has a central opening therein surrounding the control shaft 18 to permit the shift gear 80 to rotate about that shaft. The shift gear 80 further includes a radial slot 84 and a conventional rotation limiting groove 86 on the opposing side from the slot 84, with a conventional limit pin 88 extending within the groove 86. A limited number of gear teeth 90 mesh with associated gear teeth 92 on the outer periphery of a shift pinion 94, which in turn is mounted on an associated throttle shaft 96. A shift lever 97 is fixed to the shift pinion 94 and is connected at one end to the shift cable 98. The entire assembly is supported in the housing 12 by a bearing plate 99. As will be described in greater detail below, the shift and throttle linkages are connected with the shaft 96 and associated hardware to control the shift and throttle cable linkages 98 and 100, respectively.
The warm up shaft 26 includes a tongue 102 at the inner end with the tongue having a ramp 104 along its outer periphery. A ball 106 is positioned within the depression formed by the ramp 104 and bears against a latch pin 108 extending through the slot 84 in the shift gear 80. The pin 108 is under compression by a ball 110 loaded with a spring 112. The tongue 102 is surrounded by a cylindrical member 114 which permits the tongue to slide axially through the housing 14. The cylindrical member 114 has a hole 115 adapted to receive the ball 106.
To warm up the marine engine, the throttle only button 24 (with the control handle 16 in the neutral position) is first depressed to move the shaft 26 axially toward the back of the housing 14. This forces the ball 106 upward into a hole in the control shaft which forces the latch pin 108 out of engagement with the hole in the control shaft. With the latch pin 108 disengaged from the control shaft 18, the control shaft 18 is free to rotate without engagement of the shift mechanism. Then the trigger 30 must be depressed to permit movement of the handle. Moving the handle will then only operate the throttle.
Upon warm up of the engine, combined throttle and shift is again obtained by moving the control handle back to the neutral position. This causes the lock rod 42 to engage the lock ring 48, and further causes the ball 106 to drop into the forward edge of the ramp 104. Then the load of the spring 112 against the ball 110 and the latch pin 108 causes further movement of the ball 106 downward across the surface of the ramp 104 to cam the throttle only shaft 26 outward thereby returning the warm up button 24 to the original position. As the pin 108 returns to its original position it is latched with the control shaft 18, thereafter causing the shift gear 80 to rotate with the control shaft 18 until such time as the throttle only button 24 is again depressed. The warm up construction described above permits manufacture of component parts at a low cost. The known prior throttle only components are very time consuming to manufacture at a reasonable cost. The warm up construction described above only requires the drilling of one hole in the control shaft 18 (the hole which engages the pin 108) and the forming of the slot 84 during the casting of the shift gear 80. Thus, the use of the radial motion shown in FIG. 4 provides a highly reliable, relatively inexpensive method for providing the throttle only feature of the control unit 10.
An alternate arrangement for providing the throttle only control is shown in FIG. 8 with like reference numerals employed with respect to the same elements which are shown in FIGS. 1 through 7.
In FIG. 8 the throttle only control comprises a knob 120 extending through the control shaft 18 and having a key 122 extending axially therefrom toward the rear of the control unit. The key 122 includes a ramp 124 similar to the ramp 104 of FIG. 4 but being ramped in the opposing direction. A detent groove 126 is positioned at the inner end of the key 122. A ball 106 is positioned in a corresponding hole in the control shaft 18 and engages the latch pin 108 which in turn is pushed inward by another ball 110 and a spring 128. In the arrangement of FIG. 8, the throttle only mechanism is activated by pulling the knob 120 outwardly causing the ball 106 to be cammed up the ramp 124 and coming to rest in the detent 126. This movement forces the latch pin 108 upward and out of contact with the control shaft 18. As a result the shift gear 80 (with which the latch pin 108 is engaged by a slot 84 like the slot of FIG. 4), is disengaged from the control shaft 18. This disengages the shift mechanism thereby permitting the control handle to provide throttle only for engine warm up.
Upon engine warm up the shift mechanism is engaged by moving the control handle 16 to the neutral position and pushing the throttle only knob 120 inward. This causes the ball 106 to initially be driven upward against the latch pin 108, ball 110 and spring 128. After the ball passes out of the detent 126 it is cammed downward over the ramp 124 coming to rest in a position which permits the pin 108 to again engage the control shaft 18 to thereafter rotate the shift gear 80 with the control shaft. The throttle only feature shown in FIG. 8 requires a manual return of the throttle only knob 120 while the throttle only feature shown in FIG. 4 automatically returns the control to a combined throttle and shift operation.
Referring to FIGS. 5 and 6, the throttle mechanism includes a detent plate 129 and a crank arm 130 which are connected for rotation with the control shaft 18, and a link 132 connecting the crank arm 130 and a throttle lever 134. The throttle lever 134 is connected to a throttle arm 136 which in turn is attached to the throttle control cable 100. Rotation between the throttle lever 134 and the throttle arm 136 is limited by a pin 138 fixed to the throttle lever 134 and extending into a slot 140 in the throttle arm 136. The purpose of this limited rotation between the throttle lever 134 and the throttle arm 136 is to absorb the motion of the crank arm 130 as it moves 30 degrees either way from dead center during operation of the shift mechanism.
To prevent the throttle control cable 100 from being moved during the 30 degrees of rotation of the handle 16 during operation of the shift mechanism, a spring 142 is inserted between the throttle lever 134 and the throttle arm 136 to keep the throttle arm tight against the idle stop while the throttle lever is moving. The spring 142 is mounted on corresponding tabs 144 and 146 on the throttle lever 134 and throttle arm 136. The throttle arm 136 is double ended so that the throttle control cable 100 can be attached to either end and be pulled or pushed to increase engine speed in the desired manner. This makes the control unit 10 useable for a variety of different engine throttle linkages. To permit a right hand or left hand control for installation on either side of the boat, the crank arm 130, throttle lever 134 and throttle arm 136 are all symmetrical so that the connecting link and spring can be assembled on either side of the throttle lever and arm.
Referring to FIGS. 1, 4, 5 and 7, a safety stop switch assembly is mounted on the rearward face of the housing 14. The safety stop switch comprises a conventional single pole single throw toggle switch having a switch arm 154 extending outward from the periphery of the cover 12. The throw of the switch is maintained in a vertical direction. The switch 152 is connected to the electrical system of the engine to turn the engine off when the switch arm 154 is in the down position. (Note electrical connection shown in FIG. 5). The switch arm 154 is partially surrounded by a switch hood 156, the edge of the hood having a lip which is positioned close to the outward end of the switch arm 154 when the switch is in the "up" position (Note FIG. 7). Slanted wing portions extend between the periphery of the cover 12 and the lip.
The safety stop switch 152 is also provided with a key 158 which comprises a closed loop which can be positioned under the hood 156 to encircle the switch arm 154 (Note FIGS. 1, 4 and 7). The thickness of the key 158 is dimensioned so that it cannot pass between the switch arm 154 and the hood 156 while the switch arm 154 is in the "up" position. The key 158 further includes a hole at the bottom for receiving a lanyard 160 which can be attached to the operator of the boat.
In use, if the operator of the boat accidently falls overboard, the lanyard 160 pulls the key 158, causing the switch arm 152 to be pulled to the down (and off) position, thereby interrupting operation of the engine. The engine may be restarted and operated by reaching under the hood 156 and forcing the switch arm 154 into the up or "run" position. This permits the engine to be started and then run without continuous manual operation of the safety stop switch 152. This is useful in emergencies to permit a passenger to operate the boat without using the key 158.
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A control unit for an engine of the type requiring shifting control between forward, neutral, and reverse and throttle control for engine speeds between idle and high speed includes a housing having a control handle rotatably supported by the housing. Shift and throttle linkage means within the housing are connected to the engine and are responsive to rotation of the handle for separate control of the shift and throttle of the engine during respective portions of the arc of rotation of the handle. A throttle only shaft extends from the housing and is connected to the handle. A latch means is connected to the throttle only shaft to engage and disengage the shift linkage while permitting operation of only the throttle function responsive to rotation of the handle.
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The United States Government has rights in this invention pursuant to contract no. DE-AC05-84OR21400 between the United States Department of Energy and Lockheed Martin Energy Systems, Inc.
FIELD OF THE INVENTION
The present invention relates to improved high temperature ceramic articles, and more particularly to such articles which have a corrosion resistant coating of AlN thereon.
BACKGROUND OF THE INVENTION
Silicon based ceramics such as SiC, Si 3 N 4 and their composites have been developed for use in high temperature structural applications. Upon oxidation, a thin SiO 2 scale forms on the surface of the Si-based materials. Since SiO 2 is highly impervious to the diffusion of oxygen, the formation of the oxide scale retards further oxidation of the underlying ceramic. While they are highly oxidation resistant, Si-based materials can be susceptible to corrosion induced by deposits containing corrodants such as Na 2 SO 4 , Na 2 CO 3 , and oxide slags 1 . In certain gas turbine, heat engine, and fossil environments, Na 2 SO 4 forms in the gas phase as a result of reactions between fuel and air impurities. Depending on temperature and pressure conditions, Na 2 SO 4 can condense onto the surface of an Si-based component and subsequently destroy the protective SiO 2 scale by forming molten sodium silicates at temperatures above 850° C. The reaction likely proceeds in a manner shown by the following equation:
Na.sub.2 SO.sub.4 (l)+xSiO.sub.2 (s)→Na.sub.2 O.x(SiO.sub.2)(l)+SO.sub.3 (g)
Once the protective SiO 2 layer is consumed by the formation of the molten sodium silicate layer, the rate of the oxidation process is no longer limited by the supply of oxygen through the scale. Therefore, if the corrodants are continually present in the system, the formation and dissolution of SiO 2 at the surface are sustained, resulting in rapid surface recession and undesirable microstructural changes.
Therefore, corrosion protection of Si-based materials is desirable for its robust utilization in high temperature environments. A protective coating is needed which functions as a physical as well as chemical barrier between corrodants and Si-based materials. However, in order to develop a suitable coating system, a set of very challenging materials criteria must be met. None of the criteria set forth hereinbelow should be compromised to satisfy other criteria:
1. A candidate coating material should be intrinsically resistant to the corrodants.
2. A candidate coating material should be thermodynamically and kinetically stable with respect to the products of oxidation and corrosion reactions.
3. A candidate coating material should be able to withstand residual and thermal stresses associated with processing and thermal cycling in order to maintain coating adherence and durability; the coefficient of thermal expansion (CTE) of the coating material and the substrate should be matched as closely as possible.
4. A candidate coating material should be compliant, a property which largely depends on its Young's modulus in a direction parallel to the substrate.
5. A candidate coating material should have a pin-hole and microcrack free microstructure.
In briefly reviewing the corrosion resistance of bulk ceramics, pure Al 2 O 3 is proven to be highly resistant to Na 2 SO 4 corrosion because of its relative stability with respect to Na 2 O 2 ,3. Y 2 O 3 stabilized ZrO 2 (YSZ) is also observed to be corrosion resistant 3 , but may be susceptible to structural destablization due to Y 2 O 3 leaching by some corrodants 4 . Unfortunately, Al 2 O 3 and YSZ in the form of coatings do not adhere well to SiC and Si 3 N 4 substrates because of relatively large CTE mismatches 5-7 . On the other hand, mullite (3Al 2 O 3 .2SiO 2 ) has a CTE value similar to that of SiC 8 ,9 whereas its intrinsic resistance to hot corrosion appears to be not as good as that of the other oxides 3 . Plasma spraying has been mainly used to deposit thick mullite coatings (0.58 to 0.99 mm) on SiC 5-9 . Some of the mullite based coatings provided protection up to 500 hours in a corrosive environment containing Na 2 CO 3 at 1200° C. 5 . However, the presence of porosity and microcracks in such coatings eventually allowed corrosion products such as sodium aluminum silicates to form at the substrate interface.
Hot gas filters are required for cleaning gas streams prior to entering gas turbines in pressurized fluidized bed combustion, integrated coal gasification combined cycle systems, and other advanced combustion systems. Conventional filters are generally comprised of SiC particulates dispersed in a day or glassy binder. Such filters typically fail because of thermal or mechanical shock, or corrosion of the binder phase. Fiber reinforced hot gas filters have been recently introduced which consist of continuous ceramic fibers for strength and durability and chopped fibers for porosity control. The entire structure is then overcoated with theoretically dense SiC to rigidize the filter and improve the corrosion resistance. Unfortunately, at 870° C., a typical operating temperature of the filters, sodium species condense on the filter, corrode the SiC overcoat and degrade the properties of the filter. Currently available fiber reinforced hot gas filters, usually with a chemically vapor deposited SiC matrix or binder, are subject to hot corrosion of the SiC under adverse combustion conditions. Means is needed for protecting the SiC from sodium corrosion up to a temperature of about 870° C., or even as high as 1000° C.
Several protective coatings have been investigated in recent years, with no success. One such coating was chemically vapor deposited alumina. However, the mismatch in thermal expansion between SiC and alumina was so great that the coatings cracked and spalled off of the substrates. Beta alumina coatings were then investigated because of their reduced coefficient of thermal expansion. These chemically vapor deposited coatings were very difficult to apply and also proved ineffective because of reaction with sodium species. A third material that was investigated was Ta 2 O 5 . Unfortunately, it reacted very readily with sodium sulfate under some conditions.
Chemically vapor deposited mullite (3Al 2 O 3 .2SiO 2 ) coatings are currently under study. However crystalline coatings with the appropriate stoichiometry are very difficult to apply and maintain, as noted hereinabove.
Various materials applied by thermal spraying methods have also been investigated. However, they are not appropriate because thick coatings would blind the filter.
For further helpful information, please refer to the following patents and publications:
1. U.S. Pat. No. 5,075,160, issued Dec. 24, 1991, the entire disclosure of which is hereby incorporated herein by reference.
2. U.S. Pat. No. 5,035,923, issued Jul. 30, 1991.
3. N. S. Jacobson, "Corrosion of Silicon-Based Ceramics in Combustion Environments", J. Am. Ceram. Soc., 76, 3 (1993).
4. M. G. Lawson, F. S. Pettit, and J. R. Blachere, "Hot Corrosion of Alumina", J. Mater. Res., 8, 1964 (1993).
5. J. I. Federer, "High Temperature Corrosion of Heat Exchanger Materials", Proceedings of the Symposium on Corrosion and Corrosive Degradation of Ceramics, pp. 425-443, edited by R. E. Tressler and M. McNallan, published by The American Ceramic Society, Westerville, Ohio, 1990.
6. R. L. Jones, "The Development of Hot Corrosion Resistant Zirconia Thermal Barrier Coatings", Proceedings of the 1990 Coatings for Advanced Heat Engines Workshop, pp. II-67-76, Castine, Maine, August 1990.
7. J. I. Federer, "Evaluation of Ceramic Coatings on Silicon Carbide", Surf. Coat. Tech., 39/40, 71 (1989).
8. J. R. Price and M. van Roode, "Corrosion Resistant Coatings for Silicon Carbide", Proceedings of the Symposium on Corrosion and Corrosive Degradation of Ceramics, pp. 469-493, edited by R. E. Tressler and M. McNallan, published by The American Ceramic Society, Westerville, Ohio, 1990.
9. M. van Roode, J. R. Price, and R. E. Glidersleeve, and C. E. Smeltzer, "Ceramic Coatings for Corrosion Environment", Ceram. Eng. Sci. Proc., 9, 1245 (1988).
10. K. N. Lee, R. A. Miller, and N. S. Jacobson, "Development of Thermal Shock Resistant Mullite Coatings on Silicon Carbide", Ceramic Transactions, Vol. 38, Advances In Ceramic Matrix Composites, pp.565-575, edited by N. P. Bansal, published by The American Ceramic Society, Westerville, Ohio, 1994.
11. K. N. Lee and R. A. Miller, "Long-Term Durability of Mullite-Coated Silicon-Based Ceramics", in Proceedings of the 18th Annual Conference on Composites and Advanced Ceramic Materials, Cocoa Beach, Fla., 1994.
12. D. Suryanarayana, "Oxidation Kinetics of Aluminum Nitride", J. Am. Ceram. Soc., 73, 1108 (1990).
13. R. G. Smith, J. H. Eaton, D. D. Johnson, E. A. Richards, "Fabrication of Full Scale Fiber Reinforced Hot Gas Filters By Chemical Vapor Deposition", Proceedings of the Seventh Annual Conference on Fossil Energy Related Materials, pp. 119-127, Oak Ridge, Tenn., May 11-13, 1993, compiled by N. C. Cole and R. R. Judkins, Report No. ORNL/FMP-93/1, Oak Ridge National Laboratory.
14. W. Y. Lee, W. J. Lackey, and P. K. Agrawal, "Kinetic and Thermodynamic Analyses of Chemical Vapor Deposition of Aluminum Nitride", J. Am. Ceram. Soc., 74, 1821 (1991).
15. D. P. Stinton and D. W. Graham, "Chemical Vapor Deposition of Ta 2 O 5 Corrosion Resistant Coatings", Proceedings of the 1992 Coatings for Advanced Heat Engines Workshop, pp. IV-65-77, Monterey, Calif., Aug. 3-6, 1990.
OBJECTS OF THE INVENTION
Accordingly, it is an object of the present invention to provide a new and improved adherent, corrosion resistant coating for ceramic articles which are used in high temperature corrosive environments.
It is another object of the present invention to provide a coated high temperature ceramic article, the coating providing inertness with respect to corrodants such as sodium species, thus isolating the corrodants from the ceramic article.
Further and other objects of the present invention will become apparent from the description contained herein.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, the foregoing and other objects are achieved by a ceramic article which includes a porous body of SiC fibers, Si 3 N 4 fibers, SiC coated fibers or Si 3 N 4 coated fibers, having at least one surface, the article having a coating of AlN adherently disposed throughout at least a portion of the porous body.
In accordance with another aspect of the present invention, a filter element for removing particulate matter from high temperature fluid streams includes:
a porous preform base fiber material of selected refractory fibers having a selected average pore size; and
a coating of AlN on each of the refractory fibers of the preform of a thickness sufficient to provide corrosion resistance during use of the filter element.
BRIEF DESCRIPTION OF THE DRAWING
In the drawing:
FIG. 1 is a graph showing corrosion resistance of an article prepared in accordance with the present invention.
For a better understanding of the present invention, together with other and further objects, advantages and capabilities thereof, reference is made to the following disclosure and appended claims in connection with the above-described drawings.
DETAILED DESCRIPTION OF THE INVENTION
AlN has been found to be an ideal coating material for corrosion protection of ceramic materials, especially hot gas filters, for at least the following reasons:
1. At temperatures below about 1000° C., AlN is intrinsically resistant to the corrodants that do the most damage to high temperature ceramic articles such as hot gas filters.
2. At temperatures below about 1000° C., AlN is thermodynamically and kinetically stable with respect to the products of oxidation and corrosion reactions.
3. AlN is able to withstand residual and thermal stresses associated with processing and thermal cycling in order to maintain coating adherence and durability; the coefficient of thermal expansion (CTE) of AlN and the substrate are very closely matched.
4. AlN is compliant, having an appropriate Young's modulus in a direction parallel to the substrate.
5. AlN coatings can be applied which have a pin-hole and microcrack free microstructure.
Oxidation of AlN to Al 2 O 3 at temperatures of above 1000° C. 10 appears to limit the use of the coating to temperatures not exceeding 1000° C. in applications involving exposure of the article in oxygen containing atmospheres. However, for hot filter applications, temperature requirements are generally below 870° C. 11 , but can vary from about 300° C. for gasification systems to about 900° C. for pressurized fluidized bed combusters. Furthermore, since AlN forms a highly corrosion resistant Al 2 O 3 scale upon oxidation 2 , AlN should be an ideal coating candidate to protect hot filters from hot corrosion.
Chemical vapor deposition (CVD) is a suitable method of preparing AlN coatings since a modified CVD technique 11 is currently used to fabricate hot filters from Si-based ceramic and glass fibers. The CVD method produces uniform, high purity, dense coatings throughout the filter. Other conventional coating deposition methods may be suitable for various applications of the present invention.
The AlN coating is useful for corrosion protection of many types of ceramic articles, especially ceramic fiber filters made of SiC fibers, Si 3 N 4 fibers, SiC coated fibers or Si 3 N 4 coated fibers.
EXAMPLE I
AlN was deposited on hot isostatically pressed Si 3 N 4 (GN10, Allied Signal) by reacting AlCl 3 with NH 3 in a hot wall CVD reactor. The following processing conditions were used:
Temperature=900° C.
Pressure=0.66 kPa
NH 3 flow rate=150 cm 3 /min at STP
Ar flow rate=500 cm 3 /min
Cl 2 flow rate=30 cm 3 /min
Cl 2 gas was used to chlorinate Al pellets to produce AlCl 3 vapor. The above conditions were selected generally in view of the work of Lee et al. 12 The rate of coating growth was typically in the range of 5 to 10 μm/h. As shown in FIG. 1a, the X-ray diffraction (XRD) pattern of an AlN coating deposited on Si 3 N 4 indicated that the coating was highly textured with a strong preferred orientation to the 002! direction. The coating was about 20 μm thick. The underlying Si 3 N 4 substrate was not detected by the XRD analysis. The weight of the coated sample was 0.3966 g.
In order to evaluate the corrosion resistance of the coated sample, the sample was loaded with 13.4 mg/cm 2 of Na 2 SO 4 and subsequently subjected to a flowing O 2 environment for 100 hours at 850° C. and 101 kPa. After the exposure to the corrosion treatment, the weight of the sample was 0.4086 g. The XRD pattern of the corroded sample shown in FIG. 1b crystalline Na 2 SO 4 sample was covered with a layer of crystalline Na 2 SO 4 . The AlN coating underneath the Na 2 SO 4 layer was also detected in the XRD pattern. When the sample was ultrasonically washed in warm distilled water, the Na 2 SO 4 layer was dissolved in the water as evidenced by the disappearance of the Na 2 SO 4 diffraction peaks in FIG. 1c. The weight of the washed sample was 0.3966 g which was identical to that measured before the corrosion test. These XRD and weight measurement data showed that the AlN coating was effective in protecting the Si 3 N 4 substrate from Na 2 SO 4 induced corrosion at 850° C.
While there has been shown and described what are at present considered the preferred embodiments of the invention, it will be obvious to those skilled in the art that various changes and modifications can be made therein without departing from the scope of the inventions defined by the appended claims.
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A ceramic article which includes a porous body of SiC fibers, Si 3 N 4 fibers, SiC coated fibers or Si 3 N 4 coated fibers, having at least one surface, the article having a coating of AlN adherently disposed throughout at least a portion of the porous body.
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This application is a continuation of U.S. application Ser. No. 536,874, filed Sept. 29, 1983, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to an image processing apparatus and a processing method which can efficiently correct and collect topographical information. More particularly, it relates to an image processing apparatus and processing method which are well-suited to provide topographical information to vehicles or robots having an automatic traveling function.
A map which indicates topographical information, namely, the arrangement of roads, buildings, obstacles, etc. is indispensible to a traveling type robot. In a conventional traveling type robot, input images in the form of topographical information have been handled independently for respective frames of data. In, for example, a system having a plurality of photographing devices, the outputs of the respective photographing devices have been stored in independent memory devices, and images inputted in time series have also been stored in respectively separate memory devices.
With such a storage method, however, the information is overlappingly stored, and hence, a large storage capacity is required. This has resulted in the disadvantage that, in determining the action to be taken by the traveling type robot, a considerable effort is required for extracting essential information.
SUMMARY OF THE INVENTION
The present invention has for its object to provide an image processing apparatus and processing method which can prepare a correct map by revising a previously given map on the basis of topographical information delivered from an image input device in time series with the traveling of an automatic traveling object, such as a robot.
In one aspect of performance of the present invention, an image processing apparatus comprises storage means for storing data representing a previously given map, calculation means for preparing a predictive topographical image on the basis of the data, means for inputting actual image information successively during the traveling of an automatic traveling object, means for comparing the predictive image with the actual image, and correction means for updating the map data within the storage means on the basis of the comparison result.
In another aspect of performance of the present invention, an image processing method comprises a first step of reading out map data from storage means, a second step of predicting an output of an image input means and calculating a predictive image on the basis of the map data, a third step of comparing an input image delivered from the image input means and the predictive image so as to obtain a difference image, and a fourth step of updating the map data of the storage means on the basis of the difference image.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing an example of a traveling robot control system which employs an image processing apparatus according to the present invention;
FIG. 2 is a diagram showing an embodiment of the image processing apparatus of the present invention;
FIG. 3A is a diagram of the image memory;
FIG. 3B is a flow diagram of processing of data from the image memory to produce the predictive image;
FIGS. 4 to 6 are diagrams for explaining another embodiment of the arithmetic unit in FIG. 2; and
FIGS. 7 to 10 are diagrams for explaining an embodiment of a correction unit in FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram showing an example of a traveling robot system to which the present invention is applied. Referring to the figure, numeral 1 designates a traveling robot which is equipped with a crawler 10 and a manipulator M driven by respective motors. The detailed construction of such a robot is disclosed in U.S. patent application Ser. No. 476,271 by way of example.
The control circuit 2 of the robot 1 is connected to the storage device 6 of a control station 5 through transmitter-receivers 3, 4. The storage device 6 includes a general building file 61 and an individual building file 62. Upon receiving a radio signal from the control station 5, the control circuit 2 controls the operation of the robot 1. The robot 1 includes an image input device 7, such as television camera, the output of which is applied to an image processor 8. Information on the actual traveling direction and velocity of the robot 1 are sent from an encoder 11 and a gyroscope 12 to the control circuit 2, and are used for the control of the robot 1 and for image correction, as will be described in more detail hereinafter.
FIG. 2 is a block diagram showing an embodiment of the image processor 8 in FIG. 1. Referring to FIG. 2, the image processor 8 includes a main memory 82 for storing map data, an arithmetic unit 83 which calculates a predictive image from the map data received from the main memory 82, an auxiliary memory 84 which stores the difference between an input image received from the image input device 7 and the predictive image calculated by the arithmetic unit 83, and a correction unit 85 which updates the content of the main memory 82 on the basis of the difference signal stored in the auxiliary memory 84. The image input device 7 is placed on the traveling robot, and is manipulated by another manipulation means.
A map is stored in the main memory 82. In accordance with the present invention, the expression "map" signifies data providing information as to the positions, sizes, shapes etc. of roads, buildings, obstacles, etc. existing around the robot. More specifically, a member which employs storage elements arrayed in, e.g., two dimensions, and in which the data of the items, sizes, shapes etc. of roads, buildings, obstacles etc. are written in the arrayed elements shall be called the "map". In other words, the content of the main memory 82 expresses the surroundings of the robot in the form of electric signals. For example, as seen in FIG. 3A, the image memory may be implemented by an array of storage cells Im (i, j), where i and j represent the addresses along respective axes. Such an array may comprise 255 storage cells in each of the i and j directions so that the boundaries are:
S1[i=0, 0≦j≦255]
S2[i=255, 0≦j≦255]
S3[0≦i≦255, j=0]
S4[0≦i≦255, j=0]
At each array element specified in terms of i and j, for example the height of the object located at the spatial point is stored. It should be noted that the capacity of the image memory 82 is dependent only on the complexity and the number of objects to be identified for robot operation and is independent of the positioning accuracy and the number of the points at which the robot observes the environment for positioning.
The arithmetic unit 83 calculates the projection of the topography (the configuration of the surrounding objects on the ground) expressed by the map, on the basis of the map stored in the main memory 82, the position of the robot, the photographing direction of the image input device 7, and the focal length of the lens used. This calculation is done for the following purpose.
The content of the main memory 82 signifies topography created on the basis of information obtained through the image input device 7 and used to update topography data previously stored and based on theoretical knowledge of the topography, and so, is not definite topography obtained by surveying the actual surroundings. Accordingly, the topography indicated by main memory 82 does not always agree with the actual one. In this sense, the map of the present invention expresses an imaginary landscape. Here, a subject for approaching the propriety of the map will be considered. At this time, when it is remembered that the actual topography cannot be directly measured and that only the image obtained through the image input device 7 is utilizable, a processing is performed on the basis of the level of the input image to correct the stored topography. More specifically, an image is obtained by correlating the topography expressed by the map of the main memory 82 to that observed through the image input device 7, whereby the propriety of the map is determined. As stated above, the arithmetic unit 83 delivers as its output the image which is forecast to arise from the imaginary landscape. In this sense, the output of the arithmetic unit 83 shall be called the "predictive image".
A process for correcting the map by the use of the predictive image will be explained below with reference to FIGS. 1 and 2.
Step 1; The data stored in the general building file 61 is transmitted to the main memory 82.
Step 2; The traveling movement of the robot 1 is started. This traveling movement of the robot 1 is controlled by the control circuit 2.
Step
3; The outputs of the encoder 11 and gyroscope 12 are integrated, and then applied to the arithmetic unit 83.
Step
4; The predictive image is prepared by the arithmetic unit 83 on the basis of the data read out of the main memory 82 and the data inputted at Step 3.
Step
5; The photographed (actual) image produced by the image input device 7 is applied to the auxiliary memory 84.
Step
6; The reverse image of the output (predictive image) of the arithmetic unit 83 is applied (added) to the auxiliary member 84.
Step
7; The difference image representing the difference between the photographed image and the predictive image is applied to the correction unit 85.
Step
8; The output of the correction unit 85 is added to the content of the main memory 82, thereby to correct the data stored in the main memory 82.
Step 9; The data of the main memory 82 is transmitted to the individual building file 62.
Step 10; Whether or not the robot is present at a stop position is discriminated. Unless it is present at a stop position, the process returns to Step 1. If it is present at a stop position, the subsequent operation is stopped.
In obtaining the predictive image at Step 4, a view along an optical path which extends from a topographical item such as a building to the image input device 7 may be calculated. The series of processing for calculating the predictive image can be performed by digital operations. To this end, the simulation of the optical path which extends from the road, building, obstacle or the like stored in the main memory 82, to the image input device 7 may be done with a computer.
An example of the simulation is illustrated in FIGS. 4 to 6. First, it is assumed that a map of the contents indicated by numerals 820 and 821 in FIGS. 4 and 5 by way of example are stored in the main memory 82. In the figures, the symbols 0 1 , 0 2 and 0 3 shall indicate objects such as buildings and obstacles. It is also assumed that the image input device 7 is positioned at a point corresponding to point p on the map and is delivering an image of a landscape in a range corresponding to θ 0 -θ 1 . A predictive image 830 in FIG. 6 to be obtained on the basis of the map 820, 821 is prepared in accordance with the following algorithm, which is illustrated by the flow diagram of FIG. 3B:
[Algorithm A]
The range θ 0 -θ 1 is divided by N K (eight in the example of FIG. 6) to determine dθ and K is set to zero. (Step A1) Thereafter, in Step 2A, i is set to ip, j is set to zero; after which θ is set to θ 0 +K*dθ, resulting in θ=θ 0 . (Step 3A)
An object is retrieved successively in the direction θ from the point p. In the example of FIG. 5, the object 0 1 is found at a distance aO from the point p. This is performed by decrementing i (Step A5) and calculating j based on the angle θ(Step A6). This is followed by calculating the distance γ along the angle θ(Step A7). This is repeated until the object 0 1 is detected by reading out a height value from memory 82.
The height l a of the object 0 1 is read from the main memory 82. (Step A8) The magnification α(γ aO ) of the lens in the image input device 7 is evaluated as a function of the distance γ aO , and an image height l a ' is calculated as follows:
l.sub.a '=α(γ.sub.aO)·l.sub.a
A device of the height l a ' is depicted at the position θ 0 on the predictive image plane 830. (Step A9) Then the height angel L is updated (Step A10) based on the image height l a and the distance γ.
The retrieval continues from γ aO in the direction θ. At this time, objects of height less than (γ/γ aO )l a for various γ's are neglected. (Steps A9 and A10 are skipped) In the example of FIG. 4, the object 0 2 is found at a point γ=γ bO .
The height l b of the object 0 2 is read from the main memory 82. (Step A8) The magnification α(γ bO ) of the lens is evaluated as a function of the distance γ bO , an image height l b ' is calculated as follows: ##EQU1##
A device of the height l b ' is added over the device corresponding to the object 0 1 , at the position θ 0 on the predictive image plane 830. (Step A9)
Until the distance reaches the boundary of the map, operations similar to (Step A3)-(Step A10) are repeated. When the boundary of the map is reached, θ is altered to the next division by incrementing K (Step A11), and the process is returned to (Step A2). Further, when θ=θ 1 holds, the operations are ended.
While, in the aforementioned [Algorithm A], the retrieval is performed successively in the direction θ, such processing may well be done in parallel.
Next, a process for correcting the map with the predictive image will be described in detail with reference to FIGS. 7 to 10. First, it will be assumed that, at an initial time t O , a map as indicated by symbol 820A in FIG. 7 is stored in the main memory 82. Here it is supposed that the existence of a building a and a T-shaped road b are known surroundings at the time t O at which the motion of the robot starts. Of course, in a case where no knowledge of the surroundings is available at the time t O , the stored content 820A is blank, that is, a road is assumed to extend over the whole surface. Even in this case, the process to be stated below applies quite similarly. In the map 820A shown in FIG. 7, a circle ○ (P O ) denotes the position of the robot, and an arrow indicates the traveling direction thereof.
Here , it is assumed that the robot is traveling so as to be positioned at the fore end P 1 of the arrow at a time t 1 (t 0 <t 1 ) At this time, the arithmetic unit 83 carries out the computation as explained in conjunction with FIGS. 4 to 6 and delivers a predictive image as indicated by symbol 830A in FIG. 8. It is now assumed that an input image as shown in 840A in FIG. 9 is received from the image input device 7 at the time t 1 . Herein, the following differences are detected between the predictive image 830A of FIG. 8 and the input image 840A of FIG. 9:
(i) Topographical items e 1 and e 2 appear in the input image 840A.
(ii) In the images the positions of the roads are different.
(iii) On the basis of the detected results, the correction unit 85 updates the stored content of the main memory 82 into a map 820B shown in FIG. 10. Here, a building a' is added in correspondence with e 1 , and the position of the robot is corrected from P 1 into P 1 '. Here, it is decided that the item e 2 is a figure depicted on the road and is omitted on the map. The decision is made on the basis of a position where the difference image e 2 exists, or the position of an object which is thought to produce the difference image e 2 .
Here, the new object a' is added on the map. This is performed in conformity with the following algorithm:
[Algorithm 1]
(Step 1-1)
Among objects which might produce difference images, the largest one is placed on the map.
(Step 1-2)
In the object set anew, a part which is contradictory to a known road, building or obstacle is deleted.
(Step 1-3)
An input image is gained anew, and the algorithm is returned to Step 1-1.
[Algorithm 2]
(Step 2-1)
Among objects which might produce difference images, the smallest one is added on the map.
(Step 2-2)
An input image is gained anew, and the algorithm is returned to Step 2-1.
In the aforementioned algorithm 1, the unknown object contracts with the addition of information based on the input image. In contrast, in the algorithm 2, the unknown object expands with increase in information. In either case, it is to be understood that, as more information is stored with the traveling movement of the robot, or the like, the map converges to the true topography.
As described above, the function of the correction unit 85 for use in the present invention is realized by a computer. In this case, however, the operator's judgment may well be utilized. It is of course possible that the operator performs all the correcting operations. Especially in the latter case, the predictive image and the input image are arrayed and presented in front of the operator, whereby the computation of the difference image can be omitted.
As set forth above, according to the present invention, the efficient storage of image information becomes possible. As a result, the control of a machine which operates using the image information as inputs can be facilitated.
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In processing topographical information necessary for the traveling of a robot or the like furnished with an automatic traveling function; topography is predicted from the topographical information previously given, so as to prepare a predictive image, a difference image between the predictive image and an actual image caught by a television camera installed on the robot or the like is obtained, and the obtained result if used for correcting the topographical information previously given.
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